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™ GBOLOGICAL SURVEY OF ILLINOIS,

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VOL USE LT.

PALEONTOLOGY.

DESCRIPTIONS OF VERTEBRATES.

BY J. S. NEWBERRY AND A. H. WORTHEN.

DESCRIPTIONS OF INVERTEBRATES,

BY F. B. MEEK AND A. H. WORTHEN.

+» DESCRIPTIONS OF PLANTS.

BY LEO LESQUEREUX.

~ ILLUSTRATED

_ BY THE WESTERN ENGRAVING COMPANY, CHICAGO

PUBLISHED

BY AUTHORITY OF THE LEGISLATURE OF ILLINOIS.
1866.

STATE JOURNAL STEAM PRESS, SPRINGFIELD, ii.

INTRODUCTION.

Ir is well known to Geologists that life did not first burst
into existence in the forms of plants and animals we now see
around us. On the contrary, there were many successive steps
in the great work of creation: the organisms of one period, after
subserving the ends for which they were called into existence,
passing gradually away, to give place to new types, which in
their turn became extinct. Although there were partial ex-
ceptions to the general rule, each successive fauna and flora
(using these terms in their widest signification) presented, on
the whole, an improvement upon the preceding; or, in other
words, the first created forms were amongst the most simple in
structure, and hence the lewest in the scale of life; while those
that came after, as time passed on, were more and more highly
organized, until at last MAN, the highest type of all, appeared to
exercise dominion over all existing beings.

During these long ages and cycles of the past, the earth
itself was undergoing many mutations, both from the action of
internal igneous forces, and external agencies. Islands and
continents were rising above or sinking beneath the ocean
level; mountain chains were being upheaved and vast areas were
alternately submerged, and again raised above the level of the
sea, to be occupied by immense marshes, supporting dense
growths of strange trees, shrubs and herbaceous plants, which,
by their death and accumulation through long“ periods of time,
formed the material of our coal beds. During all this time,
solid rocks, where exposed, were, as at present, slowly crumbling
under the disintegrating influences of rains, frosts and other
atmospheric agencies, to be swept by streams into seas, estuaries
and lakes, to form beds of sand, clay or marl, or to be consolidated

EV INTRODUCTION.

into rocky strata, which, as time rolled on, were again raised to
form plains, hills and mountain chains, subject to the same
ceaseless round of destruction and re-formation to which they
owed their origin.

But the materials of which even our hardest stratified rocks
are composed were not, in every instance, entirely and directly
derived from the wreck of pre-existing solid rocks, for there
was some working over of the same materials, without the action
of the intervening process of consolidation; and the remains of
corals, crinoids, shells, and other marine organisms, often con-
tributed much the larger portion of the substances composing
marine strata, while in other instances the remains of land and
fresh-water animals and plants, carried in by streams, form con-
siderable portions of extensive estuary and lacustrine formations.
Hence, as the animals and plants of each of the great epochs,
although mainly different from those of the preceding and fol-
lowing ages, presented, with occasional exceptions, a remarkable
general similarity during each individual period, over the entire
globe, their fossil remains furnish the Geologist an unerrmg
guide in the identification of strata, and the determination of
their position in the series, as well as of their relative ages. As
the learned Antiquary determines the age and history of some
ruined city, in regard to which both written and traditional
history are silent, by a careful study of the inscriptions upon its
walls, or of the seals, coins, medals, etc., found amongst its rub-
bish, so does the skillful Paleontologist determine the period
of the earth’s history to which an outcrop or stratum of rock
belongs, and its place in the geological series, by inspecting its
imbedded organic remains.

When it is therefore borne in mind, that coal and other valua-
ble minerals were not indiscriminately distributed through the
earth, but were mainly formed or deposited, at least in quantities
and under conditions to be useful to man, during particular
geological periods, the importance of knowing to what epoch of

INTRODUCTION. Vv

the earth’s history the rocks of any given district belong, before
undertaking mining enterprises of any kind, will be readily
understood, and the intelligent general reader will at once
comprehend why it is that geologists give so much attention to
fossils. In short, the first and most important step in the
prosecution of a geological survey, is a careful and thorough
study and investigation of the organic remains found in every
seam and stratum of the rocks of the district to be explored ;
for without a. knowledge of these, all conclusions in regard to
the geological structure of the country, or of the age and position
in the geological column of its rocks, must necessarily be vague
and unreliable. Indeed, without the aid of Paleontology,
Geology would scarcely be entitled to rank as a science at all.
But aside from all mere utilitarian considerations, there is
much in the history of these mute relics of by-gone ages—
extending, as it does, deep into the mysterious past, and reveal-
ing, as it were, glimpses of the successive steps in the great
work of creation itself—that must ever render them objects of
the most profound interest to all reflecting minds. When it is
remembered, too, that the rocks of our State are unusually rich
in these interesting remains (to a great extent new to science),
we can scarcely be mistaken in supposing that the citizens of
the great State of Illinois will feel a commendable pride in
contributing their share to the general stock of knowledge, in
a department of science now claiming so much attention from
enlightened minds throughout the civilized world. Nor can
we believe the people of Illinois desire that the students of our
schools and colleges, and others, justly ambitious to keep pace
with the great minds of other lands, in every department of
learning, should be longer dependent upon reports published
by our neighboring States for a knowledge of these wonderful
works of the Creator, so profusely scattered at our feet, even if
it were possible to find the desired information there. Hence
we think any extended statement of the motives that have

vi . INTRODUCTION.

induced us to give the necessary attention to this department
of the survey, would be uncalled for, and out of place here.

In the preparation of this volume on the Paleontology of the
survey, 1t will be observed that almost exclusive attention has
been given to the organic remains of the Carboniferous rocks.
This has been done, first, because the most important stores of
mineral wealth found within the limits of the State, occur in
these rocks; second, because they occupy far the larger portion
of its area; and third, because these strata contain more organic
remains, entirely new to science, than any of our other forma-
tions. In a part of a succeeding report, however, now in an
advanced state of preparation, it is intended, should the Legis-
lature make an appropriation for its publication, to give figures
and descriptions of enough of the characteristic fossils of the
other formations to give completeness to the whole, and afford
students and intelligent miners the means of determining to
what geological period the rocks at any outcrop belong, in any
part of the State to which their attention may be directed. It
will not, however, be necessary to occupy so much space, in any
future report, with figures and descriptions of fossils, as was re-
quired here in laying, as it were, a foundation for the whole work.

It will be observed that, in a few instances, we have figured
and described fossils from adjoining States. ‘This, however,
has only been done where the same formations occur in Illinois,
but have not yet afforded us as perfect specimens of the particu-
lar species as those obtained at localities outside of the State.

The fact that this volume consists of several distinct memoirs,
prepared by parties working to a considerable extent indepen-
dently, has prevented that degree of uniformity, in the plan of
the whole, that would otherwise have prevailed. As each sec-
tion, however, treats upon a different department of Palzeon-
tology, and a list of all the species is given at the end of this
Introduction, arranged by formations and in accordance with
their affinities, as far as they go in each rock, without regard to

INTRODUCTORY. . VII

their distribution in the several memoirs, little inconvenience
can arise from the want of a more systematic arrangement of
the contents of the volume.

In the portion of the work devoted to the description of the
Vertebrates, the species are described much in the order that

the figures were most conveniently arranged and numbered on
the plates, and not always in accordance with their zoological

or geological relations; though the locality and position of each
species is mentioned at the end of its description, and.a syste-
matic synopsis of the species is given at the close of the memoir.

The Invertebrates, excepting the Polyzoa (which are all de-
scribed together in a supplementary paper), are described in the
order of their geological succession, and arranged zoologically,
as far as they go ineach formation. The fossil plants are also,
like the Polyzoa, described together in a separate section, mainly
in the order of their botanical relations. The geological position
and locality of each species, however, is mentioned in connection
with its description.

The whole number of species of all kinds, illustrated and
described, is about 325, of which nearly 300 were discovered or
first made known to science through the agency of the Ilinois
Geological Survey. Of these 325 species, 50 are plants, 156
Invertebrate animals, and 119 Vertebrates. Altogether they
represent 115 genera, 25 of which have been established by
parties connected with the survey. Of these genera 18 are
plants, 67 Invertebrates, and 30 Vertebrates—the latter of
which, with one exception (a Batrachian), being all fishes. Of
the 115 genera represented, 81 are more or less fully character-
ized, and most of them illustrated in this volume.* 3

The various rocks from which these fossils were obtained
having been described, and their relations fully discussed, in the

* As no other single volume of Palzontology, hitherto issued in this country, con-
tains so large a number of generic descriptions, and as most of these descriptions, even
of previously established genera, have been carefully rewritten, and more or less modi-
fied from the study of extensive collections of specimens, it is hoped that this feature
of the Report will add materially to its value and usefulmess, especially to studenis who
may not have access to extensive libraries of works on Paleontology.

vull

first volume of this Report, it would be superfluous to enter into
any extended remarks on that subject here; but for the conve-
nience of those not familiar with our geology, who may use this
volume without always haying the other directly at hand, the
following section, showing the order of succession, maximum

INTRODUCTION.

thickness, etc., of the strata of this State, is given:

ILLINOIS ROCKS. — FEET.
POSE-TOrtiary -c-cessercccsevessseesennans Dat, Loess, ete—Clay, sand, pebbles, boulders, etc........ vmenni|meLO)
Tertiary..... Eocene period?...... Clays and greenish sand........:sssesserserees 150

z Carboniferous Coal Measures and ) Coal, shale, clay, limestones, sandstones
S period, Millstone grit. and CONGLOMELALE .......2.seeceeeceeessserese}| 1200
a f Fibs weer
a | Chester group.—Limestone, sandstone and shale....... Rococo 3036 800
3
z St. Louis beds.—Limestone and shale....... pocebrngenenreococcere cose 200
I 2 Mountain limestone
[o} i .
Ey 3 aan onifer- Keokuk group.—Limestone and shale 150
1S) ——
Burlington group.—Coarse, subcrystalline limestone............ | 200
Kinderhook group.—Shales, limestone, sandstone, ete.........| 150
4 Genesee division.—“Black slate” and grayish shale.............. 100
a Hamilton period.....
a « Dark grayish, foeted and lighter, more pure
ral Hamilton beds. { NITIES TOW S re censteeet aeaceeese tenes tneescneepeccmaeeeenee 120
4 U. Helderb. period.|Cornif. and Onondaga beds._Gray, more orless sandylimest.| 25
oS .
Bie a a Oriskany—upper bed.—Quartzose sandstone............+++sseseeee- 40
A HISRBDYSPELIOG- cre: Oriskany—lower beds, \ Highly silicious, very cherty magne-
or Clear-ecreek group. f sian limest., usually i in thin layers.. 200
Lower Helderberg group, ) More or less magnesian and argil-
{ [Lower Heldenbere, 2 Sadly tenest sof Nt Y.S laceous limest., in thin layers,
By Deg: COLOGISES) -..-eeseeceesereeees including flinty concretions..... 200
a
2 I Niagara period ...... Niagara group.—Magnesian and argillaceous limestones...... 200
a Cincinnati period...|Cincinnati group.——Limestones, shales and sandstone........... 140
2 Magnesian, and more or less
5 g Trenton period...... Galena and Trenton beds. {} here LimestoneS...ssescseeeeseeees 300
a ) —
ni St. Peters division—Pure quartzose sandstone..........sseseese-+ 150
Potsdam or Primor-
Ht arc auD ees Calciferous division —Magnesian limestones and sandstones.| 120
seen.

4 ————<—<$$<$<<

Pe

_ INTRODUCTION. IX

In regard to the nomenclature used for the rocks represented
in the foregoing section, as well as respecting some modifications
made in the same since the publication of the first volume of
this Report, it may be proper to add some remarks. In the
first place, it will be observed that we have (with a few excep-
tions, to be mentioned farther on), retained the names by
which these formations are most generally known. In doing
so, however, we have dropped the words “sandstone,” “lime-
stone,” etc., as parts of these names, and substituted the words
“esroup, “division,” or “beds,” in those names in part derived
from lithological characters. Names of the latter kind, or those
suggested by the presence of some particular species or genus
of fossils at the localities where rocks were first studied, are,
from the instability of such characters, often found extremely
inapplicable, when we attempt to trace strata far from the origi-
nal localities. For this reason, and their consequent liability
to mislead the student, there is a growing disposition amongst —
the highest authorities in geology to drop the objectionable parts
of such names, and retain only those portions of the original
names derived from the typical localities. In this connection,
we need only refer to such works as Prof. Dana’s Manual of
Geology, and Sir Wint1AM Locan’s Report on the Progress of
the Canadian Geological Survey, published in 1863.

For the lowest division of the Subcarboniferous series, we
have used the name Kinderhook group, provisionally proposed
by us, in 1861, for a group of arenaceous and more or less cal-
careous strata, at the base of the Subcarboniferous, that had
been referred by Prof. HALL, and some others, to the Chemung
group of the New York series, very generally regarded as be-
longing to the Devonian system. Being unable to identify a
single Chemung species amongst all our collections from this
horizon, and finding them, as a group, decidedly more nearly
allied to Carboniferous forms, as well as, in some instances,
undistinguishable from species in the Carboniferous limestones

pa) Nov. 1, 1866

x INTRODUCTION.

above, we proposed for this formation the name Kinderhook
group, from its development at the village of that name in Pike
county, of this State—stating, at the same time, that we could
no longer view it as the equivalent of the Chemung, and that
we regarded it as being more intimately related to the Carbon-
iferous above, than to the Devonian below. It is proper that we
should state here, that this opinion was also previously main-
tained by M. pz Vernevin, Dr. Norwoop and Dr. Owen, as well
as some others.

At the time we proposed the name Kinderhook group for
this formation, little was known in regard to its relations to
some similar deposits Prof. Wicuz.u had called the Marshall
group, in Michigan, and to what the Ohio geologists had desig-
nated as the Waverly sandstone, in Ohio. Since then, however,
we have traced this rock into Northern Ohio, and ascertained,
beyond doubt, that it is the same as the Waverly sandstone, or
at any rate, as the only portion (the upper part) of that series
in which we succeeded in finding fossils. Prof. WIncHELL, who
concurs in the opinion that these beds belong to the Carbonif-
erous, has also since identified his Marshall group with the
Waverly sandstone. It is therefore probable that the oldest
name— Waverly sandstone, or more properly, Waverly group—
will have to be adopted for this formation. Until all questions
in regard to the exact parallelism of these deposits, as developed
in the several States alluded to, can be cleared up, however, by
farther investigations, it will be better to retain the local names
by which they are now known in the States mentioned.

In the first volume of this Report, just published, on the
general geology of Illinois, the name “ Clear creek limestone”
was provisionally used for a series of strata holding a position,
in Union and some of the adjoining southern counties, between
the so-called Hudson river group of the Lower Silurian, and a
Devonian sandstone that had been identified with the Oriskany
sandstone of New York. Formerly, when only a few imper-

INTRODUCTION, XI

fectly preserved fossils were known from these beds below the
sandstone mentioned above, they were regarded as most proba-
bly belonging mainly, if not entirely, to the Upper Silurian
epoch. During the progress of the detailed county surveys of
that region, however, Mr. Eneetmann found a few additional
fossils, at different horizons above the middle of this doubtful
series, which were submitted for examination, and found to
indicate that at least a considerable portion of these beds are
more nearly allied to the Oriskany sandstone than to the Upper
Silurian. The fact, however, that the few specimens, with one
exception, then obtained in a condition to be identified, were
found to belong to species that are known to be, in New York or
Canada, common both to the Oriskany formation and the Lower
. Helderberg group, left it still a matter of doubt, without farther
examinations and the additional collections of fossils; at what
precise horizon in this series the line should be drawn between
the Devonian and the Upper Silurian. Consequently the whole.
group between the two horizons mentioned above was, in the
first volume, designated as the “Olear-creek limestone,’ with
the statement that the line between the Upper Silurian and
Devonian should probably be drawn somewhere through this
group.

Wishing, if possible, to clear up this doubtful point, we
availed ourselves of a short, unavoidable delay in the progress
of the printing of this volume on Paleontology, to spend a few
days in examining these rocks in Union county, and some of
the adjoining portions of Missouri. As the lower portion of
this doubtful series seems to be nearly destitute of fossils in
Illinois, we directed our attention first to outcrops of these beds
on the opposite side of the Mississippi, in Perry county, Mis-
souri, where they were already known to be fossiliferous. Ata
point a little below Bailey’s Landing, in Perry county, we col-
lected a number of fossils, clearly establishing the fact that the’
whole thickness, of over two hundred feet, exposed there, be-

XII INTRODUCTION.

longs to that portion of the Upper Silurian forming the “Shaley —

limestone” division of the Lower Helderberg group, to which
Dr. SuumArpD had correctly referred these beds in the Missouri
Report. Aniong the fossils collected by us here, there are forms
we cannot distinguish from the following New York “Shaley
limestone” species, viz: Orthis subcarimata and O. oblata, Hall;
Coelospira concava and C. imbricata, Hall; Spirifer perlamellosus,
Hall; Platyceras spirale, Hall; P. Gebhardi and Acidaspis hama-
tus, Conrad. We also found there species scarcely, if at all,
distinguishable from the “Shaley limestone” species, Merista
princeps, Platyceras pyramidatum, P. unguiforme, P. incile and
P. multistriatum, Hall.

Farther down the river, in the southern part of Perry county,
Missouri, the hills, for over two hundred and fifty feet in height,
are composed of the same beds seen at Bailey’s Landing, and
the cherty beds we now include as a part of the Oriskany
group, all dipping to the eastward. We found only a few
fragments of fossils here, however—barely enough to assure us
of the identity of the strata.

On crossing over into Union county, Illinois, in the region
of Jonesboro’, we had an opportunity to examine the cherty
beds alluded to above, and found them characterized (with the
exception of Platyceras Gebhardt) by an entirely different group
of fossils from those seen near Bailey’s Landing, and still farther
confirming the conclusion that these beds belong to the Oriskany
period. Including those collected by Mr. EncEtmann, and a
few that were collected by one of us from these beds in Jack-
son county, together with those found during our late exami-
nations, we can safely give the following list of well-known
Oriskany species, as occurring in this formation in Southern
Illinois, namely : Leptocelia flabellites (sp.), Conrad ; Lepteena ?
nucleata, Rhynchonella speciosa and Platyceras tortuosum, Hall ;
with Eatonia peculiaris and Platyceras Gebhardi, Conrad. These
are associated with Lensseleeria Condoni, McChesney, which,

els a | eh ae oe
i) 1 Om TP cae

INTRODUCTION. XIII

if not identical with the New York Oriskany species, R. ovalis,
of Hall, is certainly a very closely allied representative species;
also, with several undetermined species of Spirifer, some of
which are nearly related to S. arctus, Hall, and S. arenosus,
Conrad, from the New York Oriskany: and a Stricklandiana,
we have not been able to entirely satisfy ourselves is distinct
from §S. elongata (=Pentamerus elongatus), Vanuxem. In New
York, S. elongata is characteristic of the higher Onondaga lime-
stone of the Upper Helderberg, but in Canada it is common to
that position and the Oriskany sandstone.

Judging from such an assemblage of fossils as this, and the
entire absence, so far as yet known, of any species in these
beds peculiar to any lower horizon (although Platyceras Geb-
hardi and Eatonia peculiaris are, is New York, common to the
“Shaley Limestone” division of the Lower Helderberg group
and the Oriskany), we cannot resist the conclusion, that a
considerable portion of the cherty limestone forming the upper |
part of the Clear-creek series, as first understood, belongs to
the Oriskany period, and that the line between the Upper
Silurian and the Devonian, of this region, should be drawn
between these cherty beds and the strata below, equivalent to
those from which we collected the Lower Helderberg fossils at
Bailey's Landing. Exactly how far down in the series this
line should be carried we are unable to say, as we found no
abrupt lithological change, and we saw no fossils near the
horizon of the probable junction. From all the facts, however,
we are led to believe that possibly as much as two hundred
feet, and perhaps more, of these beds should be included in the
Oriskany.

In the sandstone immediately overlying the cherty beds,
near Jonesboro’, Union county, we found the following fossils (or
more properly their moulds—the fossiis themselves being, in all
cases, dissolved out so as to leave empty cavities), viz: A small
Zaphrentis, Pleurodictyum problematicum, Goldf.; an Orthis like

XIV INTRODUCTION.

O. musculosa, Hall, but smaller; a finely striated Strophedonta,
having the form and general appearance of S. magnifica, Hall,
but also of smaller size; the same Stricklandiana so abundant
in the cherty beds below; and fragments of one of those curious
types of Dalmania? for which Mr. Conran proposed the generic
name Odontocephalus, but much larger than the well known
O. selenurus, from the Upper Helderberg limestone—being pro-
bably not less than six inches in length, when entire. The
presence in this bed of this type of Trilobites, and the coral
Pleurodictyum problematicum, which, according to M. pr VEr-
NEUIL, occurs in Indiana associated with well known Cornif-
erous and Onondaga fossils, leads us very strongly to suspect
that it will be found to belong more properly to the Upper
Helderberg series, with which, as developed here, it also agrees
‘more nearly, in its lithological characters, than to the rocks
below; but as the associated Brachiopoda seem rather to indi-
cate relations to the underlying cherty beds, we have concluded
to place it provisionally as an upper stratum of the Oriskany,
until a larger number of species can be obtained from it for
study.

Directly overlying the above mentioned sandstone, there is
to be seen, at various places in Union and some of the neigh-
boring counties, a light-grayish, very hard, semi-crystalline,
often sandy, massive limestone, sometimes passing into alterna-
ting beds of limestone and quartzose sandstone. The fossils
found in this formation are the following, viz: Very large,
exceedingly thin-jointed crinoid columns, Centronella hecate, Bil-
lings; Spirifer acuminatus, Con. (—S. cultryugatus, Roemer) ;
several undetermined Spirifers, greatly extended on the hinge
line; S. fimbriatus, Conrad? Atripa reticularis, Linn.; a small
Productus, like P. subaculeatus, Murchison, but apparently more
distinctly costated ; Platyceras dwmosum, Conrad ; and another
species of the curious type of TZrilobites, mentioned as occurring
in the sandstone beneath, but smaller and more nearly like the

INTRODUCTION. XV

the New York Corniferous species, Odontocephalus selenurus of
Conrad. j

From this group of fossils, geologists will readily understand
that we have here a representation of the Upper Helderberg
series, probably consisting of a blending of the Corniferous and
Onondaga beds of the New York geologists. Consequently we
have added this formation, which had not been previously iden-
tified in our State, to the Illinois section.

Above the Upper Helderberg rocks, just mentioned, we have
the Hamilton beds proper, well marked by characteristic fossils;
and over these, the Genesee division of the Hamilton group
(=“Black slate” of western geologists), which latter is suc-
ceeded by the Kinderhook and other Subcarboniferous rocks.

In selecting names for the New York rocks, the surveyors of
that State very properly named each formation after the locality
where it is best developed; the expressed object being, accord-
ing to Prof. Hatt, “to give the name from the locality which |
_ afforded the most complete and extensive exhibition of the
strata composing the group.” Hence the great series of shales
and argillaceous sandstones, so extensively developed along the
Hudson river, above the Highlands, was called the “Hudson
river group.”. With the exception of Graptolites, few fossils
had been found in these rocks, though im a few little isolated
outliers, occupying synclinal axes, somewhere in the region of
the Hudson river, supposed to belong to this group, and now
said by Prof. Haun to be “of insignificant extent,” specimens
of Leptena sericea, Orthis testudinaria, Asaphus and Trinucleus
had been found. From this latter fact, beds then known by
the local names Pulaski shales and sandstone, Lorraine shales,
etc., containing these and other fossils (as well as the associated
Utica slate), and holding a position above the Trenton group,
at localities farther west in New York, were by the New
York geologists referred to the Hudson river group, which they
consequently placed above the Trenton in their columnar series.

XVI INTRODUCTION.

The equivalents of these shales, etc., in the western States,
were also, for the same reasons, referred to the Hudson river
group.

The discoveries of the last few years, however, chiefly made
by the Canadian Geological Survey, have gradually developed
the fact that the New York geologists (excepting Dr. Emmons*)
had made a great mistake in placing the true Hudson river
rocks above the Trenton: or in other words, that these rocks
are older than the Trenton, and belong to the Primordial zone
of Barrande. Consequently the slates and shales alluded to
farther west, in New York, and their equivalents in the western
States, cannot be properly referred to the Hudson river group.
In a note on this subject, published in the Report of the Wis-
consin Survey (pages 443 to 445), Prof. HALL, after speaking
of the great number of Primordial types of fossils found in the
Hudson river group in Canada, and some of the adjoining
States, within a few years past, makes the following remarks:

* * * «Weare therefore satisfied, from the geological rela-
tions of the great mass of these rocks, and from the contained
organic remains, that they are of older date, and that the fossils
of newer age occurring in limited localities should not be re-
garded as characterizing the formation; that the great mass ot
the Hudson river rocks, in their typical localities, are older
than the Lorraine shales and sandstones of Pulaski, etc.; and that
the term Hudson river group cannot be properly extended to
these rocks, which, on the west side of the Hudson river, are
separated from the Hudson rwer group, proper, by a fault not
yet fully ascertained.”

“There can be no propriety,” he continues, “in transferring
the name Hudson river group from its typical locality, and
applying it to rocks we now know to be of younger age, and

* It is well known that Dr. Emmons had long maintained, against a vigorous and not
always over courteous opposition, that the Hudson river group proper holds a lower
stratigraphical position than had been assigned it by his collaborators of the New
York Survey.

INTRODUCTION. XVII

which, when the sequence is complete, are separated from the
Hudson river rocks by a great limestone formation.”

“T have therefore,’ he goes on to say, “dropped the term
Hudson river group, in its application to the rocks of Wisconsin
which are of the age of the Lorraine shales of New York and
the Blue limestone group of Ohio.”

For the reasons thus clearly stated, he denominates this
- group, on pages 47 to 56 of the Wisconsin Report, quoted above,
simply as the “Green and Blue shales and limestones,” stating
there, also, in another note on page 47, that the term Hudson
river group had been improperly extended so as to include the
beds of this age west of the Hudson river, and could “no longer
with propriety be applied to these western rocks.”

Perfectly concurring in this opinion, and being equally well
satisfied that such a descriptive phrase as the “ Green and Blue
shales and limestone” could not be retained, in geological nomen-
clature, as a name for a great formation, widely extended in the
United States and Canada, under various aspects of color and
composition, we felt greatly at a loss for a convenient name for
this group. As the local names Utica slate, Lorraine shales,
etc., had been originally applied, and long in general use, for
subdivisions of this formation for which it is convenient and
necessary to have separate names, when we wish to speak with
precision of these subordinate rocks, they will of course always
be associated, in the minds of geologists, with the beds in con-
nection with which they have been so long used ; consequently
none of them could, without creating confusion, be extended to
the whole group. The term “Blue limestone,” long since used
for this group by the Ohio geologists, is open to the same
objection as that used in the Wisconsin Report, being equally
derived from such unstable characters as mere color and com-
position. Nor could we retain Prof. Rocrrs’s term “ Matinal,”
nor Prof. SArrorp’s name “ Nashville group,” for the reason that
they were each originally applied to, and since used for, a series

—3 Noy. 10, 1866.

XVIII INTRODUCTION.

including both the Trenton and the so-called Hudson river
groups, and hence could not be used when we wish to speak of
the group under consideration as a distinct formation from the
Trenton.

In order to have a convenient name for this formation, that
would be applicable wherever and under whatever lithological
characters it might be found, and at the same time mean this
particular group—neither more nor less—we proposed, in a
paper published in the Proceedings of the Philadelphia Acade-
my of Sciences, August, 1865, p. 155, to call it the Cincinnati
group, now retained in the accompanying section, and used in
the first volume of this Report. We do not think it would be
possible to select a more appropriate name than this, Cincinnati
being widely known as one of the great commercial cities of the
west, while the formation named is perhaps more extensively
developed and exposed there than at any other place, and is at
the same time so highly fossiliferous at that locality, that its
characteristic fossils have been widely distributed, by local and
traveling geologists, almost throughout the civilized world.
Hence when we speak of the “Cincinnati group,” geologists
will everywhere know exactly to what horizon we refer, with-
out a word of explanation.

After reading the quotations we have made from the Wiscon-
sin Report, it will be readily understood that one of the writers,
on exhibiting a section of the Illinois rocks before the American
Association for the Advancement of Science, at the late Buffalo
meeting, was not a little surprised that Professor Hat should
object to the term Cincinnati group, and insist upon retaining
for this formation the name Hudson river group, on the ground
that it is represented on the Hudson river by the isolated masses or
outliers already alluded to. That geologists will, however, sanc-
tion such a transfer of the name of a great geological formation
from the group to which it was originally applied, and for which
alone it is acknowledged to have been intended, to another

INTRODUCTION. XIX

group, simply because there happens to be a few patches of the
latter, of “insignificant extent,” in the same region, we cannot
believe. Such a misnomer would impose upon the student the
perplexing confusion of ideas resulting from the necessity of
having always to bear in mind that the Hudson river rocks, so
greatly developed along that stream, are not the Hudson river
group, but something else; and that the Hudson river group, if
existing on the Hudson river at all,* is only represented there
in the form of a few insignificant masses, so small that very

few geologists have ever been so fortunate as to see them.
F. B. M. and A. H. W.

* It is worthy of note that the few fossils mentioned to prove these little patches
identical with the Cincinnati group—that is, Leptxna sericea, Orthis testudinaria, Asa-
phus and Trinucleus—are forms that also occur in the Trenton group, so that unless
some decidedly characteristic species of the group under consideration, not yet men-
tioned, also occur there, we would, from the stratigraphical relations of these forma-
tions, have better reason to refer even these outliers to the Trenton period, than to
alater formation. Hvenif they should, however, be found filled with the characteristic
fossils of this western formation, their presence there, under such circumstances, would
not warrant us in transferring to them the name Hudson river group, from the great
series of older rocks to which it was originally applied.

Notz.—In an introductory letter to the first volume, it was stated that an effort had
been made by the enemies of the Survey to break it up, by repealing the law under
which it was organized, and that it was only saved from destruction by the interposi-
tion of the executive veto. In making this statement, we inadvertently omitted to
mention to whom the cause of science was indebted for this noble interference in her
behalf; and it is but just to his Excellency, the Hon. Richard Yates, to say that it is
to him that the Survey is indebted for its present existence, and for the opportunity to
bring out for the information of the public so much of the results as are comprised in
these two volumes. We feel assured that this noble act will be remembered and ap-
preciated by the friends of science everywhere. A. H. W.

TABLE OF CONTENTS.

PAGE
LRMERDRUCTID HS c50 00 de os re oDOO seNG.Ue Obs 5440 onan ospue SCAB Ono OnOORonOCUe I
SECTION L. d
Descriptions of new species of Vertebrates, mainly from the Subcarboniferous lime-
stones and Coal Measures. By J. S. Newberry and A. H. Worthen............... 9
Remarks on the Occurrence of Fossil Fishes in Illinois. By A. H. Worthen.......... 11

Supplement to descriptions of Vertebrates—consisting of a description of a new genus
and species of Reptiles, from the Coal Measures.. By Prof. Edw. D. Cope.........135

SECTION IL.

Descriptions of Invertebrates from the Carboniferous system. By F. B. Meek and A. H.
WU CINCO edo ondaAaaapooaonenbacs Fobateata fovea eta tavaratal opebsvel eiayeye cis talet aera otesbatel a) lets 148

Supplement to the descriptions of invertebrates—consisting of descriptions of Polyzoa
from the Paleozoic rocks. By H. A. Prout, M.B..........ese ee eees boobpdngode 412

A SECTION III.
Report on the Fossil Plants of Mlinois. By Leo Lesquereux......+2s02202ereeneees 425

LIST OF

DESCRIBED IN THIS VOLUME,

1, DEVONIAN SYSTEM.

HAMILTON PEREOD.
Hamilton Division.
MOLLUSCA.

POLYZOA.

Polypora hamiltonensis, Prout ....page 423
VERTEBRATA.

PISCES.

Rinodus calceolus, N. and W.......... 106

2, CARBONIFEROUS SYSTEM

A=-SUBCARBONIFEROUS PERIOD.

1. Kinderhook Group.
PROTOZOA.
SPONGLE.

Sphenopoterium enorme, M. and W..p. 146
var. depressum,

RADIATA.

ECHINODERMATA.
Actinocrinites pistilliformis, M. and W..151
MOLLUSCA.

BRACHIOPODA.

Rhynchonella missouriensis, Swallow. ..153

Spirifer cooperensis, Swallow.......... 155
LAMELLIBRANCHIATA.
Cardiopsis radiata, M. and W.......... 157
GASTEROPODA.
Straparollus lens, Hall, (sp.)........... 169
Bellerophon cyrtolites, Hall ........... 160

FOSSILS

ARRANGED BY FORMATIONS.

CEPHALOPODA.

Nautilus trisulcatus, M. and W....page 162

— . digonus, M. and W........... 163
Goniatites Lyoni, M.and W........... 165
VERTEBRATA.

PISCES.
Orodus ? multicarinatus, N. and W..... 62
Helodus biformis, N. and W........... a
— placenta, N. and W........... 80
2. Burlington Group.
RADIATA,
ECHINODERMATA.

Dichocrinus conus, WE BLING ak Shon 5 169
Platycrinites subspinosus, Hall......... 173
Cyathocrinites sculptilis, Hall.......... 178
Poteriocrinites Swallovi, M. and W..... 183
Zeacrinus Troostanus, M. and W....... 186
Strotocrinus regalis, Hall, (sp.)......... 192
Steganocrinus araneolus, M. and W..... 198
Actinocrinites concinnus, Shumard..... 200
— scitulus, M. and W...... 202

—- dodecadactylus, M. and W.205
— asteriscus, M. and W....207
Amphoracrinus subturbinatus, M. and W .212
Celocrinus concavus, M. and W........ 215
Gilbertsocrinus fiscellus, M. and W. .. 222
Palechinus burlingtonensis, M. and W . .230

MOLLUSCA.

LAMELLIBRANCHIATA,

Avyiculopecten burlingtonensis, M. and W.231

II LIST OF FOSSILS.
VERTEBRATA, LAMELLIBRANCHIATA,

4 PISCES. Aviculopecten Oweni, M. and W....... 256
Petalorhynchus striatus, N. and W...... 40 _ amplus, M. and W...... 257
Antliodus simplex, N. and W.......... 44 _ oblongus, M. and W....258

— parvul and ais doogn aon me aacaedcene
Polyrhizodus porosus, N. and W...... as ; :

Dhomstoaus, aincilimune eed a £1 Pleurotomaria Shumardi, M. and W.....260
— multiplicatus, N. and W... 57 VERTEBRATA.
Orodus tuberculatus, N. and W........ 66 eee j
— elegantulus, N. and W...... Meine i
Helodus coniculus, N. and W.......... 45 | Cladodus angulatus, N. and W......... 24
== anpulatusy oN panduWaejmieecmiome 83 — micropus, N. and W......... 21
— compressus, Nevandaw tae nee "8 — robustus, (Ni and! Wisaerianee sis 20
ee patina, "NE an dl sWesreciereisistetersmiare 80 _ turritus, N. and W........ «.- 28
Trigonodus major, N. and W........... 112 — ~ lamnoides, N. and W........ 30
Deltodus complanatus, N. and W....... 98 | Diplodus duplicatus, N. and W......... 61
— . spatulatus, N. and W........ 100 — incurvus, N. and W.......... 62
Antliodus similis, N. and W....-..-..-. 41
pi a he — cucullug) Nand) Wi. scimes.c)- 41
PROTOZOA. — poliius, Nevand) Wil. 42
SPONGIA. — minutus, N. and W.......... 43
Sphenopoterium obtusum, M. and W....233 ag Se, Be IAS eae oe 22
is compressum, M, and W.284 Chomatodus ae WHE EMCO Gide Aa ape ~- 54
— pusillus, N. and W......... 53
RADIATA. — loriformis, N. and W ...... 58
ECHINODERMATA. — molaris, N. and W........ 56
Cyathocrinites angulatus, M. and W.... -234 a Costa Beane Wisk acre BD
= Saffordi, M. and W...... 236| 0 = elegans, N. and W.......- 86
Zeacrinus planobrachiatus; M. and W...240 Orodus Ounatus; Ni and W tne se eden ee 65
Onychocrinus monroensis, M. and W....244| — ™ammillaris, N. and W......... 66
fee Norwoodi, M. and W..... 245| — Tminusculus, N. and W.......... 67
racks Ci — minutus, N. and W............ 68
; Cochliodus ? crassus, N. and W........ 91
Oligoporus Dane, M. and W........... 249 tii nobilis, N. and W........ 89
MOLLUSCA. Helodus consolidatus, N. and W....... 87
ROUT. — crenulatus, N. and W......... 82
eae : — denshumani, N. and W..... poo, fe
Coscinium Wortheni, Prout............ 412 — denticulatus, N:.and W...... 81

— tuberculatum, Prout........ 415 — elytra, N. and W.21 oacssecaee 48

_— asterta, Prottiiie ss s1s0 cisterns 6 416 — gibbosus, N. and W........... 49

7 eschanense, PrOUte elcsiclereiers .» 416 — politus, N. and W............ 49
Cyclopora fungia, JPROU Sipe eon cu ae one 419 — uleatus, N.and W........... 88

—_ discoidea, LOU. tencw ayer os fcise 420 — (Cochliodus) nobilis, N. and W. 88
Polypora gracilis, Prout............... 422 Sandalodus angulatus, N. and W....... 103

BRACHIOPODA. — levissimus, N. and W....... 104
Camarophoria subtrigona, M. and W....251 — grandis, N. and W......... 105

Chonetes planumbona, M. and W....... 253
Athyris planosuleata, Phillips ? (sp.)....254

Psammodus semicylindricus, N. and W..108
— ? rhomboideus, N. and W....110

-

, ce
oe
‘ "

aw! Nov. 11, 1866.

LIST OF FOSSILS. y Til
Trigonodus minor, N. and W.......... 112 | Cladodus magnificus, Tuomey....... 3. 24
Pecilodus rugosus, N. and W...... Och che — ferox, N.and W............. 26
_— ornatus, N. end W.......... 95 | Antliodus mucronatus, N. and W...... 38
Deltodus stellatus, N. and W.......... 97 | Dactylodus princeps, N. and W........ 45
— undulatus, N. and W.......... 98 — lobatus, N. and W.......... 47
Oracanthus pnigeus, N. and W.......-. 117 | Petalodus linguifer, N. and W.......... 37
Drepanacanthus gemmatus, N. and W..123 | Orodus plicatus, N. and W............ 68
— ?stellatus, N. and W...125 | Sandalodus spatulatus, N. and W...... 103
4. St. Louis Group. — parvulus, N. and W........ 102
PROTOZOA. Psammodus rugosus, N. and W........ 108
Deltodus rhomboideus, N. and W...... 100
BEONGLE Ctenacanthus? costatus, N. and W.....120
Sphenopoterium cuneatum, N. and W...262 | Homacanthus gibbosus, N. and W...... 116
RADIATA. — rectus: Ne-and Wis-ni: 2). 115
Leptacanthus? occidentalis, N. and W..116
ECHINODERMATA. ss a
: A : _ gracillimus, N. aud W....126
Dichocrinus constrictus, M. and W..... 263 Gar eharneri) Wornens Veen = ke
Platyerinites Prattenanus, M. end W...264 ie ay Wea ares eae
— pennicellus, M. and W..... 266 5. Chester Group.
— plenus, M. and W......... 267 ‘
Taxocrinus semiovatus, M. and W...... 272 PLANT,
Granatocrinus cornutus, M. and W..... 216 Megaphytum protuberans, Lsqx........ 458
Scheenaster fimbriatus, M. and W...... 278 | Lepidodendron obscurum, Lsqx........ 453 '
MOLLUSCA. — costatum, Lsqx........ 453
POnYZOAL —_— turbinatum, Lsqx...... 453
Coscinium elegans, Prout..........--. 413 ANIMALTA,
— plumosum, Prout............ 414
— Michelinia, Prout ........... 414 RADIATA.
— sagenella, Prout............ 415
Polypora Halliana, Prout.............. 421 COS ae a
Pterotocrinus crassus, M. and W.......290
ot hicaegar ioe — chesterensis, M. and W...292
Productus scitulus, M. and W.......... 280 | Archeocidaris mucronata, M. and W.. .295
LAMELLIBRANCHIATA, MOLLUSCA.
Myalina concentrica, M. and W........ 281
Yoldia? levistriata, M. and W......... 282 POLYZOA.
Nnculana? curta, M. and W........... 283 | Cyclopora polymorpha, Mont, ccobeecan 421
GASTEROPODA. :
BRACHIOPODA.
Dentalium venustum, M. and W........ 284
Straparollus similis, M. and W......... 285 Eeoduchins parvus, ~ SG Wie ecco se 297
MSE — var. planus, M. and W.286 Spirifer glaber, Martin? (sp.).......... 298
; CEPHALOPODA. LAMELLIBRANCHIATA.
Orthoceras expansum, M. and W....... 286 | Myalina angulata, M. and W..... eye 300
VERTEBRATA. Schizodus chesterensis, M. and W...... 301
PISCES. GASTEROPODA.
Cladodus spinosus, N. and W.......... 22 | Straparollus planidorsatus, M..and W...302
— stenopus, N. and W.......... 23 | Pleurotomaria chesterensis, M. and W. .308

IV LIST» OF

FOSSILS.

CEPHALOPODA,

Orthoceras annulato-costatum, M. and W.304
Nautilus globatus, Sowerby? ...-. +--+. .305

Nautilus chesterensis, M. and W.....-.. 306
Nautilus(Endolobus)spectabilis, Mand W.308

VERTEBRATA.
PISCES.

Cladodus zygopus, N. and W......-..-. 25
— politus, N. and W............ 27

— costatus, N. and W........... 24
— grandis, N. and W..........-. 29
Petalodus linguifer, N. and W......... 37
Antliodus robustus, N. and W...-....- 39
Dactylodus inflexus, N. and W......... 48
Polyrhizodus dentatus, N. and W...... 50
— ponticulus, N. and W..... 51
Chomatodus cultellus, N. and W....... 52.
Psammodus reticulatus, N. and W...... 109
— PONOSUS PAY ieielsinieokelel lela eie 107

— angularis, N. and W..-....- 107
Aspidodus crenulatus, N. and W....... 93
—_— convolutus, N. and W...... 94

Deltodus cingulatus, N. and W......... 99

Chomatodus angustatus, N. and W..... 118

B.—COAL MZASURES.

PEANTE,

Neuropteris hirsuta, Lsqx........ 00 8 427
— rarinervis, Bunb....-...+++ 428

— IMO chly Web on Oop daudoo oo 430

— miki JUNE Soa nb co ona 431

_ verbeneefolia, Lsqx......... 431
Odontopteris Wortheni, Lsqx.......-.. 432
— °° heterophylla, Lsqx....... 433

— subcuneata, Bunb......... 433

_ requalis, Lsqx.....-se..0« 434
Sphenopteris paupercula, Lsqx......... 435
— rigid, Brongn...-....... 435
Hymenophyllites pinnatifidus, Lsqx..... 436
— spinosus, Gopp. (sp.)...436

— alatus, Brongn........ 437

—_— hirsutus, Lsqx...-.---. 437

—_ Clarkii, Lsqx...-..-.. 438
Alethopteris massillonis, Lsqx.......... 438
— crenulata, Gopp.......+.+- 439

— Btellata; (usc kee ei» ctee ellie 440,
Pecopteris callosa, Lsqx......++.-++.- 442,

Cordaites borassifolia, Lsqx...........- 443
Selaginites uncinnatus, Lsqx...+......+ 446

—_— CVASBUG) TESGaRh te rie ware prelels 0 446
Lycopodites asterophyllitefolius, Leqx . .447
Stigmaria Evenii, Lsqx..............-- 448

Sigillaria monostigma, Laqx...-........449
— Menardi, Brongn.............450

Lepidodendron diplotegioides, Lsqx....452
— Wortheni, Lsqx........ 452

—_ radicans, Lsqx......... 454

— simplex, Lsqx..........454
Lepidostrobus princeps, Lsqx.......... 455
— hastifolius, Lsqx........-456
Lepidophyllum auriculatum, Lsqx...... 457
Lepidophioyos obcordatum, Lsqx...... 457
Megaphytum MeLayi, Lsqx............ 458
Caulopteris insignis, Lsqx............. 459
— Worthenii, Lsqx.-.-..-....459
Trigonocarpum juglans, Lsqx........... 460
—_ rostellum, Lsqx.........460
Carpolithes multistriatus, Sternb.?...... 460
— Jacksonensis, Lsqx......... 461

— Clie, Wiebe AAR so.doae soa 461

—_ fasciculatus, Lsqx...-... -. 461

ANIMALTA.
RADIATA.
ECHINODERMATA,

Cyathocrinites? sangamonensis, M. and W.310

Zeacrinus discus, M. and W............ 312
—_ ? crassus, M. and W......... 314
Erisocrinus typus, M. and W....-..-... B17
— conoideus, M. and W.......318
— tuberculatus, M. and W..... 319
MOLLUSCA,
BRACHIOPODA.

Productus nanus, M. and W...-...-.-- 320
Syntrielasma hemiplicata (sp.), Hall.... .323
LAMELLIBRANCHIATA.
Aviculopecten Coxanus, M. and W..... 326
= pellucidus, M. and W....327
_— Koninckii, M. and W-.. .328
—_— interlineatus, M. and W. .329

— occidentalis, Shumard ?. .331
Streblopteria? tenuilineata, M. and W. .334
Eumicrotis Hawni var. sinuata, M. and W.338

e

— ———

LIST OF FOSSILS. Vv

Pterinea (Monopteria) gibbosa, M. and W.340

Myalina Swallovi, McChesney.......... 341
— meliniformis, M. andW........ 343
— recurvirostris, M. and W....... 344

S207, ee eee aoe 7. 845

Edmondia unioniformis (sp.), Phillips?. .346
Pleurophorus subcostatus, M. and W....347

Solenomya radiata, M. and W.......... 349

Allorisma

GASTEROPODA.

Pleurotomaria subesnstricta, M. and W. .351
— speciosa, M. and W...... 352
— scitula, M. and W........ 353
— brazoensis, M. and W.?.. .354
— tenuicincta, M. and W...355
— granulo-striata, M. and W.355
— Prattenanus, M. and W...357
— subsinuata, M. and W....357
— turbiniformis, M. and W..359
— subscalaris, M. and W....360

— ? tumida, M. and W...... 361
Straparollus umbilicatus, M. and W.... .362
Naticopsis nana, M. and W............ 365

—_— nodosa, M. and W.......... 366
= — var. Hollidayi, M. andW.367
Macrocheilus medialis, M. and W....... 370

— intercalaris, M. and W....371

Polyphemopsis inornata, M. and W..... 374
— nitidula, M. and W...... 374

— peracuta, M.andW..... 375
Loxonema scitula, M. and W........... 377
— rugosa, M. and W........... 378

— multicostata, M. and W...... 378

— cerithiformis, M. and W..... 379
Orthonema Salteri, M. and W.......... 381
Turritella?? Stevensana, M. and W ....382
Soleniscus typicus, M. and W.......... 384
Bellerophon crassus, M. and W......... 385

CEPHALOPODA.
Nautilus planorbiformis, M. and W...... 386

— sangamonensis, M. and W.--...386

Cyrtoceras curtum, M. and W....... _- 888
— ? dilatatum, M. and W...... 389
— iowensis, M. and W.........892
ARTICULATA.
ANNULATA.
Spirorbis carbonarius, Dawson?........ 462
CRUSTACEA.
Bellinurus Dane, M. and W............ 395

Acanthotelson Stimpsoni, M. and W....401
— inequalis, M. and W..... 408

Paleocaris typus, M. and W........... 405
Anthrapalemon gracilis, M. and W..... 407
MYRIAPODAs
? Anthracerpes typus, M.and W........ 409

INSECTA.
Paleocampa anthrax, Mand W........ 410

VERTEBRATA.
__-PISCES.

Palxoniscus peltigerus, Newb..... coe Mal
Rhizodus occidentalis, N. and W....... 19
Cladodus gracilis, N. and W......... ves BD)
Diplodus latus, N. and W............-. 59

— compressus, N. and W........ 60
Petalodus destructor, N. and W........ 35
Ctenoptychius semicircularis, N. and W.. 72
Chomatodus angulatus, N. and W....... 55
Helodus carbonarius, N. and W........ 15
Sandalodus carbonarius, N. and W...... 104
Deltodus angularis, N. and W.......... 97
Edestus minor, N. and W.............. 84
Drepanacanthus anceps, N. and W...... 122
Petrodus occidentalis, N. and W....... 70

se acutus, N. and W...... Morcraste 12

REPTILIA.

Amphibamus grandiceps, Cope......... 135

PALAONTOLOGY OF ILLINOIS.

SECTION I.
DESCRIPTIONS OF NEW SPECIES OF VERTEBRATES, MAINLY

FROM THE SUB-CARBONIFEROUS LIMESTONE AND
COAL MEASURES OF JLLINOIS.

By J. S. NEWBERRY anp A. H. WORTHEN.

REMARKS

ON THE

OCCURRENCE OF FOSSIL FISHES IN THE ILLINOIS STRATA,

TuE fossilized remains of fishes were observed in the Sub-
carboniferous limestone of Illinois, by one of the authors (A.
H. W.), as early as 1845; and the fact that they were the only
memorials of the vertebrated animals of the Carboniferous
period then known in this country gave to this class of fossils
a peculiar interest. As the fishes of this ancient epoch possessed.
a cartilaginous skeleton, they have left no record of their exis-
tence other than their teeth, the strong bony plates of enamel
which lined their capacious jaws, and the bony defensive spines
with which they were armed.

Although fragmentary in their character, these ichthyic
remains presented such a variety of form and size as led to the
conclusion that the number of species of vertebrated animals
that existed, during the Carboniferous period, was by no means
inconsiderable; and the bony structure of these fossils, and their
deep brown or black color and shining surfaces, contrasting
remarkably with the sober gray of the rough limestone in which
they were imbedded, rendered them objects of striking interest
to the collector of fossil remains.

In subsequent investigations it was discovered that there were
certain horizons—usually limited to a single stratum, only a
few inches in thickness—where these fossils were quite abun-
dant, though comparatively rare in the intervening beds. Four
of these “fish beds” have since been identified in the Sub-car-

a

12 PALEONTOLOGY OF ILLINOIS.

boniferous limestone series in Illinois, and from these the new
species now introduced to the notice of the scientific world
were mainly obtained.

The Kinderhook group, consisting mainly of argillaceous and
arenaceous beds, which form the base of the Carboniferous
system in Illinois, has afforded but few of these ichthyic fossils,
but on ascending to the Burlington limestone we find them
more abundant; and in the upper part of this limestone occur
the lowest beds that contain these remains, in any considerable
numbers. In the upper part of this limestone we find a single
stratum of brownish-gray rock, from four to six inches thick,
in which the teeth and spines of fishes are imbedded in great
numbers. This fish bed was first observed at Quincy, Illinois, —
and was subsequently identified, occupying apparently the same |
horizon, on Honey creek, in Henderson county, and at Augusta,
in Iowa, points nearly a hundred miles away from the first
named locality, showing that the cause which produced this
general destruction among the vertebrated animals of this
period was not local, but operated simultaneously over a wide
geographical area. At Quincy there is a seam of green shaly
clay, about two inches thick, interstratified with the lime-
stone, beneath which, upon the surface of the underlying rock,
the remains of fishes were found in considerable numbers, as
though the animals had been destroyed’ suddenly by the intro-
duction of this muddy sediment into the ocean. As this has
not been observed at any other locality, it may, perhaps, be a

. merely local phenomenon.

The second fish bed is situated some fifty or sixty feet higher
in the series, and is near the base of the quarry rock of the
Keokuk group. It has only been identified at a single locality

‘in the vicinity of Hamilton, in Hancock county. The rock is

a single stratum of soft, granular, crinoidal limestone, and its
friable character is probably in part due to surface exposure.
It is about four inches thick, and crumbles readily, under a

VERTEBRATES. 13

smart blow of the hammer, so that the delicate fossils which it
contains are often obtained entirely detached from the matrix.
Although only about ten feet square of surface was exposed-at
this locality, it has afforded more than a thousand well pre-
served teeth. So thickly imbedded were they in this single
layer, that a hand specimen of the rock, not exceeding four
inches square, often exhibits a half dozen or more perfect teeth.
The associated fossils are Productus punctatus, Actinocrinus
Nashville, Zaphrentis Dali and Sphenopoteriwm obtusum.

The third fish bed in the ascending order is found in the
upper part of the Keokuk limestone, just below the base of the
geode bed. It was first observed in the vicinity of Warsaw,
and subsequently identified at Nauvoo and some other locali-
ties in Hancock county. Itis characterized by the remarkably
large palate teeth of Cochliodus nobilis (N. and W.), and the large
spine, Drepanacanthus gemmatus. Like the beds before de-
seribed this consists of a single stratum of brownish-gray lime-
stone, not exceeding four or five inches in thickness, and

contains, besides the remains of fishes, Spirifer neglectus, S. ,

Keokuk, Productus punctatus and Zaphrentis Dalit.

stone, the teeth of fishes become comparatively rare, and are
only found as isolated specimens, sparingly dispersed through
the rocky strata. The quarries in the vicinity of Alton and

Ascending in the series to the horizon of the St. Louis lime- \

St. Louis, and near Waterloo, in Monroe county, have afforded /

a few fine species.

The Upper Archimedes or Chester limestone is more prolific,

in ichthyic fossils than the beds last named, and we again meet

with strata in this group where they are crowded into a limited \
space in great numbers. The upper fish bed is found at the /
junction of the lower limestone in the Chester group, with the |

green shales above, and the stratum containing these fossils
consists of thin plates of limestone imbedded in the shale.

The rock is usually arenaceous and sometimes highly ferru- /

14 PALMONTOLOGY OF ILLINOIS.

ginous, and in consequence of the hardness of the rock, well
preserved specimens are more difficult to obtain from this bed
than from those below. Very fine specimens are occasionally
obtained from the soft shales in which the limestone are im-
bedded, and are found weathered out upon the sloping hill-sides
below the outcrop of the bed in which they were originally
inclosed.

In the Coal Measures the remains of fishes are comparatively
rare in I}linois, and a single specimen will perhaps be the average
reward of the collector for his day’s labor in this horizon. The
shales above the Belleville coal in St. Clair county, the argilla-
ceous limestone and shale forming the roof of the coal seam
near Springfield, and the State House quarries on Sugar creek,
in Sangamon county, and an equivalent limestone at LaSalle,
have afforded nearly all the specimens yet found in the upper
Carboniferous beds in Illinois.

The new species presented at this time comprise all that
have been collected during the prosecution of the Geological
Survey of the State up to 1862, as well as the private collection
of one of the authors (A. H. W.), the result of more than ten
years’ labor, while a resident of Warsaw, in Hancock county,
and in close proximity to some of the richest deposits of ichthyic
fossils yet discovered on this continent. Although the new
species now presented to the scientific world far exceed in
number all that have hitherto been found in the paleozoic rocks
of North America, we nevertheless believe that the localities
mentioned are by no means exhausted, but will yet afford very
many other new types.

The following query may have been suggested to*the inquir-
ing mind by the phenomena we have thus briefly attempted to
describe: Why should the remains of fishes be found in such
profusion, in the limited horizons which we have termed /ish
beds, while they are comparatively rare in the intervening
strata? , It seems to have been the probable result of one of

VERTEBRATES. 15

two causes: either a superabundant development of ichthyic
life during the accumulation of the sedimentary material that
forms these thin beds of limestone, or else (and more probably)
from the sudden introduction of heated waters or noxious gases,
that caused a general and overwhelming destruction of the finny
tribes of the Carboniferous ocean at these different periods.
Such destructive agents may have been introduced, either by
the action of submarine volcanoes or of thermal springs, and it
is perhaps quite impossible, at the present time, to determine
to which of these causes, if either, we are indebted for the
phenomena we are now considering.

We know, from the recorded observations of the last century,
that a submarine outburst of volcanic fire carries destruction to
the finny tribes of the ocean as far as its influence extends,
and we may readily conceive that the prevalence of thermal
springs beneath the ocean’s level, the waters of which were
charged with mephitic gases, would produce a similar result.
If we accept the commonly received opinion that the siliceous
material which, in the form of chert and hornstone, enters so
largely into the composition of the Burlington and Keokuk
limestones, was introduced by thermal springs, we must con-
clude they were exceedingly numerous during the Sub-carbon-
iferous period, inasmuch as we find these materials so abundant

- in some beds of the Sub-carboniferous limestone series as to

constitute from one-fourth to one-half of the entire mass. Now,
if we suppose these thermal waters to have been charged with
any poisonous ingredient, we have an agent sufficiently potent
to produce a very general destruction among’ the. marine ani-
mals that were subjected to its influences.

With a profound conviction that the suggestions thus thrown
out are not altogether a satisfactory answer to the query pro-
pounded, we have nevertheless felt impressed to offer them as
the most probable solution presented by the facts before us, and
with the hope that they may lead to further investigation and —
a more satisfactory answer to this interesting inquiry.

; “A
16 PALAONTOLOGY OF ILLINOIS.

Of the 118 species of fishes described and illustrated at this
time, 16 are from the Coal Measures, 17 from the Chester
limestone, 18 from the St. Louis limestone, 49 from the Keokuk |
limestone, 14 from the Burlington limestone, 3 from the Kin-
derhook group, and 1 from. Devonian strata. ,

. . Ay Ee, We

Genus PALASONISCUS, DeBlainv.

PALAONISCUS PELTIGERUS, Newb.

Llonichthys peltigerus, N. Proc. Phil. Acad. Sciences, April, 1856.

Fig. 1.

Palzxoniscus peltigerus.

Bopy short, compressed; length 5 inches; height 1 inch, 4
lines; enameled surface of cranial bones covered with small,
thickly set tubercles; opercula and hyoid plates ornamented by
parallel convolutions of thread lines; scales all covered with
similar raised lines, which cross them diagonally downward
and backward, terminating in serrations of the posterior mar-
gin. About the middle of the interval between the occiput
and dorsal fin, on the median line, begins a row of large, oval,
ornamented scales, extending to the dorsal fin. Behind the
dorsal is a similar row, transformed into large striated fulcra,
which overlie the prolongation of the vertebral column to its
termination.

18 PALWONTOLOGY OF ILLINOIS.

composed of about 26 rays; ventrals lower, but contain:
the same number of rays; pectorals oblong, rounded a
ity, a, of. pbout 10 rays; anal fin extending from y

Illinois.
have been found in the rocks, associated with the ‘ Albert” coal, in
Brunswick. I have some imperfect specimens from there of a species y
closely allied to this, in which the only difference observable is the coarser :
stronger ornamentation of the scales. All the species from the A!bert mine,
figured by Dr. Jackson, are unmistakably Palzxonesci, remarkable for the elab-
orate ornamertation of the head, bones and scales, and for the large dorsal
scales, which, in common with the species before us, are borne by all of them. .
The finest specimens of P. pel/tigerus which I have are from beds of cannel coal
in different localities, forming one of the many facts cited by the writer (Am. pe
Jour. of Science, March, 1857) to sustain his conclusion that cannel coal was
formed from a carbonaceous pulp, derived from thoroughly macerated vegetables
suspended and deposited in water.

Formation and locality: Coal Measures, Fulton county, Illinois.

Genus RHIZODUS, Owen.

Gen. Cuar.—Jaws large, massive and bony, bearing several
large, compressed, double-edged teeth, with suleated bases in
each dental bone, with numerous intermediate ones of similar
form; scales large (1 to 5 inches in diameter), rotundate-quadrate
in outline, thin, inner surface marked by concentric wavy lines
of growth, and very finely reticulated; often marked with a
tubercle of attachment; exposed portion of exterior surface coy-
ered with a fine vermicular tuberculation.

The considerations which actuated McCoy, in separating the large, thin,
nearly plain scales, found in the Coal Measures, from the more massive and

VERTEBRATES. 19

ented ones of the ‘“‘Old Red,” seems to be quite sufficient, though
een long considered but species of the genus Holoptychius. The
loloptychti are well known by the discovery of numerous nearly
iduals, in which scales, fins and bones are almost uninjured and
3 but the so-called Holoptychii of the Coal Measures are, as yet, only
d in collections by the large, thin scales which have been referred to,

th | Ohio, what seem to be fragments of several species of Rhizodus have been
discovered, by one of the authors, consisting of large, thin, quadrate, reticulated

, numerous detached flattened teeth, and portions of jaws bearing teeth.

Fig. 2.

\
RAN

x <y

i 3 Rhizodus occidentalis.

¥ SCALES thin, rotundato-quadrate or sub-triangular in outline,

| 12 inches in diameter; anterior margin rounded; posterior scol-
loped; exterior surface unknown; interior marked with concen-

tric wavy lines of growth, and, near the margin, very finely and
beautifully striated.

' This scale is the only representative, so far as our knowledge extends, of the
a a: genus Rhizodus yet found in the rocks of Illinois. As the scales and teeth of

20 PAL-EONTOLOGY OF ILLINOIS.

other species have beet frequently met with in Ohio, it is probable that they
will be hereafter found to occur in some localities in this State in considerable
abundance. The scale before us is less quadrate in form than those of Ohio,
and apparently represents a species up to the present time undescribed.
Formation and locality : In coneretions of iron ore of the Coal Measures at _
Morris, Illinois.

Genus CLADODUS, Ag.

Gen. Cuar.—<Teeth with broad, horizontal, semi-circular,
thick, bony, coarsely-fibrous base, rounded behind, truncated
in front; crown divided into long, sharp, subulate, conical
points, arranged along the straight truncated edge of the base;
medial cone much larger than the secondary ones, of which
latter the external cones are largest; all the cones striated _
longitudinally, and either circular in section or with simple
cutting edges, slightly compressed.”

CLapopus rosustus, N. and W.
Pl. 1, Figs. 1, la.

TEETH small, robust, as high as broad; base trapezoidal, as
long as median cone, moderately thick, arched before, widest
behind, where it is somewhat rounder and emarginate, smooth
throughout; median cone conical, recurved, equally arched
before and behind with a lenticular section and cutting edges,
smooth or finely and obscurely striated ; lateral denticles rudi-
mentary and tubercular, two on either side, exterior pair largest.

In its form, curvature and section the median cone of this species closely
resembles that of C. micropus, but it is smooth or very faintly striated. The
base is also largef and more angular, and the lateral denticles are less developed.
It is quite possible that a larger amount of material would show that the two
species shade into each other, and represent the dentition of different parts of
the mouth in the fish; but until such connecting links are found, the differences
which have been enumerated will serve to distinguish them.

VERTEBRATES. 21

Fig. 1 represents the anterior face; 1a the outline of the base, upper side,
natural size. ?

Formation and locality: Keokuk limestone, Warsaw, Illinois. 2

CLADODUS micropus, N. and W.
Pl. 1, Figs. 2, 2a, 206.

TreTH of medium or small size, robust, higher than broad;
base small, shorter laterally than height of median cone, ellip-
tical, thick, rounded before and behind, and without anterior
sinus; principal cone robust, conical, strongly curved inward;
section lenticular throughout, with cutting edges; anterior and
posterior surfaces both, though unequally rounded, finely and
uniformly striated longitudinally ; lateral cusps 1-2 on either
side, very small, conical, acute, sometimes nearly obsolete.

The teeth of this species are exceedingly abundant in the ‘‘fish beds” of the
Keokuk limestone in Illinois, and the collection contains a large number of
them. They exhibit considerable diversity of form, but have as common char-
acters their small elliptical bases, robust, recurved, ancipital, striated median
cusps and dwarfed or tubercular lateral denticles. Many of the specimens are
‘evidently beach-worn, and it is possible that their bases have been somewhat
diminished, and the lateral denticles truncated by the attrition to which they
have been subjected.

There are no described teeth with which these will be likely to be confounded,
but they have much in common with two groups in the collection which have
been referred to species designated by the names of C. angulatus and C. robustus ;
and though exhibiting marked differences, which are enumerated in the deserip-
tions of the above species, it is quite possible that all formed portions of the
dentition of a single species of fish. This is merely a conjecture, however,
which can only be confirmed or disproved by the aid of more material than is
now before us.

Fig. 2, anterior face; 2a, side view; 26, outline of base from above.

Formation and locality: Keokuk limestone, Warsaw and Nauvoo, Illinois.

+.
¢

22 PALEONTOLOGY OF ILLINOIS.

CLApopus sprnosus, N. and W.
Pl. 1, Fig. 3, 3 a.

TrEtH, of medium or large size, broader than high; base
semi-elliptical, thick, smooth behind where it is brought to a
sharpish edge, before strongly beveled under and scooped out
in a shallow sinus beneath the median cone; whole anterior
border of base, above the smooth beveled edge, set with imnu-
merable minute spines directed upward; these spines cover the
anterior bases of all the lateral denticles, and the base of the
principal cone, with the exception of a small triangular space
over the centre of the basal sinus, from which they diverge
right and left, leaving the striation of the upper portion of the
cone to run down nearly to the smooth surface of the beveled
edge; median cone conical, somewhat curved backward,
rapidly drawn down to an acute point; lower portion with a
nearly circular section, finely and evenly striated longitudi-
nally; near the point smooth, compressed, with cutting edges ;
lateral denticles 6—7, on either side, conical, striated and curved
backward, exterior pair much larger than intermediate ones.

This beautiful species is readily distinguishable from all that have been
described, by its spinous base. Fig. 3, anterior face and section of median cone,
3 a, portion of base, under side

Formation and locality: St. Louis limestone, St. Louis, Missouri.

}

CLADODUS MoRTIFER, N. and W.
Pl. 1, Fig. 5.

Only a single tooth, and that much injured, represents this
species in the collection; but that is so obviously distinct from
all others, and the characters which it retains are so readily
recognizable, that it may, perhaps, justly serve as a basis for a
specific description. The summit of the principal cone is

VERTEBRATES. 25

wanting, but enough of it remains to show that it was strongly
compressed, with a lenticular section and cutting edges, was
marked with fine, sharp striz near the base, and smooth above.
The lateral denticles are two in number on either side, rela-
tively large, and differing but little in size. Like the median
cone they are striated below, smooth, compressed and ancipital
above. The outer pair must have been nearly half the length
of the middle cone. The base of the tooth is of moderate
thickness, in width about equal to twice the length of the
larger lateral denticles. |

In general aspect, the relative breadth and height, and the number and size
of the lateral denticles, this species bears considerable resemblance to C. mira-
bilis, Ag. (Pots. Foss., Vol. 3, p. 197, Atlas, Vol. 3, Tab. 22 b, fig. 9-13), but
that species is more generally and strongly striated, and the median cone has a
circular section throughout.

Figure 5. Anterior face of broken tooth, with section of median cone.

Formation and locality: Coal Measures, Sugar creek, Sangamon county, Illi-
nois.

CLApobuS sTENOPUS, N. and W.
Pl. 1, Fig. 4, 4a.

Trretu of medium size; breadth of base slightly greater than
height; base laterally elongated and narrow, semi-elliptical,
beveled to an edge behind, curved under before, where it has a
broad but shallow sinus; median cone conical, with an expand-
ed base, slightly curved backward, compressed, both anterior
and posterior surfaces flattened, and very finely and uniformly
striated.; lateral denticles 6—7 on either side, exterior pair
much the largest, intermediate ones, sub-equal.

There are no entire specimens of this species in the collection, the denticles

being all more or less truncated. The narrow, smooth, broadly-sinused base,
and the median cone, with both anterior and posterior surfaces flattened, and
yet not acutely angled, except near the point, render it distinguishable at a
glance, from the species associated with it. In size and surface markings it is

24 _ PALEONTOLOGY OF ILLINOIS.

not unlike ©. striatus-Ag. (loc. cit. fig. 14-17), but in that species this base is
much thicker and broader, and the median cone is not compressed.
Figure 4, anterior face of mutilated tooth; 4a, outline of base from above.
Formation and locality: St. Louis limestone, Warsaw, Illinois.

CLADODUS MAGNIFICUS, Tuomey.
Pl. 1, Fig. 6,6 a.
C. magnificus: Tuomey, 2d report on Geology of Alabama.

Ir is probable that this is the species to which Prof. Tuomzy
gave the above name, though not quite certain, as he has left —
no description, and only an exceedingly rude wood cut to
guide us. ' ie

The median cone, in the specimens before us, is very large
and robust, nearly as high as the base is broad, somewhat com-
pressed above and below, nearly cylindrical in the middle,
without lateral angles, unless near the summit. It is strongly
and evenly striated longitudinally. The base is very large and
thick, truncated before, thinning out behind, rather smooth on
both surfaces; lateral cones conical, smooth or finely striated,
about 5 on either side, the exterior pair largest.

Figure 6, represents the anterior aspect, and 6 a, the outline of the base

from above, natural size.
Formation and locality: Sub-carboniferous limestone, Huntsville, Alabama.

CLADODUS ANGULATUS, N. and W.
Pl. 1, Fig. 7, 8, 8a.

Trxrru of medium size, robust, width slightly less than height;
base sub-elliptical, relatively thick; median cone conical, com-
pressed, sigmoidally curved, medial portion of both anterior and
posterior surfaces flattened, giving the section an angular out-
line; both surfaces finely striated longitudinally ; lateral den-

ticles one and sometimes two on either side, generally merely
rudimentary.

VERTEBRATES. 25

Most of the specimens contained in the collection, which have been grouped
together under the above name, exhibit, in the flattening of the central portion
of the anterior and posterior surfaces, a strongly marked character by which
they may be readily distinguished from any of the species now or heretofore
described. There are other specimens, however, in which this character is not
so distinctly visible, and which are not unlike C. micropus in the form of the
median cone, but havea larger base. The teethof C. twrvitus have also a simi-
larly striated surface, and an appreach to the angular outline of those under
consideration, but in that species the lateral denticles are much larger, and the
base is relatively thinner and smaller. For the present, therefore, it seems
necessary to regard these teeth as specifically distinct from those with which
we have compared them, but it is by no means certain, that by the discovery
of new material, it will not be shown hereafter that the teeth now described
under the names of C. micropus, C. robustus, C. angulatus, and CO. turritus, form
portions of the dentition of the same fish.

Figure 7, posterior face and section of median cone; 8 and 8 a, anterior face
and base of another specimen.

Formation and loculity: Keokuk limestone, Hamilton and Warsaw, Illinois.

CiabDopus zyGorus, N. and W.
PI. 1, Fig. 9, 9 a, and 10.

TEETH small, as broad as high; base narrow, with a rela-
tively deep sinus in front, which gives it somewhat the form of a
yoke, and has suggested the name chosen; median cone conical,
broad at base, rapidly narrowed to an acute summit, distinctly
and evenly striated throughout, curved backward, anterior face
flattened and deeply excavated below by the basal sinus; sides
sharply angled below at the junction of anterior and posterior
surfaces, ancipital towards the point, posterior face rounded ;
lateral denticles, two on each side, sub-equal ; flattened before,
rounded behind, striated, acute.

This highly ornamented and pretty species belongs to a group which includes
C. Hibberti, Ag., C. gracilis and C. costatus, Nob. All of these are small in
size, have two lateral denticles on either side; have a distinct sinus at the base
of the median cone in front; have the median cone flattened in front, rounded
posteriorly with cutting edges, and marked with distinct, sharp, longitudinal

i ei ae

i
i
:
|
|
y

kj
wy
”
}
:

{

26 PALEONTOLOGY OF ILLINOIS.

strie. From each of its congeners C. Zygopus differs in several important
characters. The basal sinus is deeper than in any other species known. The
striation of the surface is finer and more crowded than in ©. gracilis or C. cos-
tatus. The lateral denticles not as long and slender as in C. gracilis, nor as
broad and flat as in ©. costatus. In C. Hibberti the lateral cusps are much
more unequal, the median cone less broad at base, and with a very shallow
sinus.

Figures 9 and 9 a, anterior face and base of small specimen; 10, anterior
face of a larger tooth; all natural size.

Formation and locality: Chester limestone, Chester, Illinois.

CLApDopuS FEROX, N. and W.
Pl. I, Fig. 11 and 11 a.

TreEtH of large size, breadth greater than height; base semi-—
elliptical, with a shallow sinus in front, smooth throughout;
median cone slightly curved backward, conical, with a circular
section, finely and evenly striated longitudinally ; lateral den-
ticles about 5 on either side; exterior pair one-third the height
of the principal cone, conical, acute, striated throughout, diver-
gent from median cone, and strongly curved backward ; inter-
mediate denticles about 4 on either side, largest, half the size of
exterior pair, conical, striated, projecting forward.

The specimens of this species, contained in the collection, do not fully give
the form of the principal cone, but it is apparently slender, conical, and acute.
The lateral denticles are of the same character, but curved backward at very
different angles; the posterior pair being set on the same line with the median
cone, and hooked backward much more than that, while the intermediate cones
are set in advance of these, and less curved. Bristling, as these teeth did,
with a multitude of sharp, fang-like denticles, pointing in different directions,
they must have been among the most effective of all the varied forms of dental
armament possessed by plagiostomous fishes. There is no described species
with which this is liable to be confounded. The form of the principal cone
was similar to that of C. striatus, Ag., (Pots. Foss. Vol. 3, p. 197, Atlas, Vol.
3, tab. 22 b, figs. 14-17), but the striation of the surface was finer, and the
number and form of the lateral denticles quite different.

Among those associated with it in the collection, perhaps Cladodus spinosus,

VERTEBRATES. | alr

Nob., approaches it nearest, but while the median cone of that species is alike
conical and similarly striated, the lateral denticles are more numerous, and the
thicker base, with its beveled anterior margin, roughened with a thousand
minute spines, furnishes a ’character which will serve to distinguish it at a
glance.

Figure 11, anterior face of broken tooth, with section of median cone; 11 a,
base underside, natural size.

Formation and locality: St. Louis limestone, St. Louis, Missour1.

CLapopus pouitus, N. and W.
Digg ait a a

TreTH small, as high as broad; base flat below, nearly
straight before, terminating in a somewhat acute edge poste-
riorly, and on either side; median cone conical, very acute,
slightly compressed, without cutting edges, smooth. and polish-
ed throughout; lateral denticles one on either side, with an
inner rudimentary one, scarcely more than a tubucle.

The anterior face of C. lamnoides is nearly as smooth and highly polished,
and, when not fully exposed, these species might be mistaken for each other;
but in C. politus the lateral cusps are not set on the edge of the base, are diver-
gent, and a rudimentary denticle is usually visible between the exterior one
and the central cone.

There is in the collection another perfectly smooth tooth which is scarcely
distinguishable from the specimens of C. politus, except that it has cutting
edges. It may be merely a variety, and at least is too near like it to justify us
in making a distinct species out of it without more material. That tooth was
obtained at Honey creek, in Henderson county, from a different geological
horizon, and very possibly will prove distinct.

Figure 12, anterior aspect, natural size.

Formation and locality: Chester limestone, Chester, Illinois.

CLaDopus costatus, N. and W.
Pl. I, Figs. 13, 13 a.

TrEeTH small; base flat, thin, anterior border straight, or
slightly convex, beveled upward and backward to the bases of

.

28 PALAONTOLOGY OF ILLINOIS.

the denticles; principal cone conical in outline, compressed,
ancipital, anterior surface marked with about 6 (3 on either
1H side of the centre) smooth, longitudinal costae, or sharp, coarse, |
prominent striz, which converge at the base of the cone; :
lateral denticles two on either side, conical, compressed, and
marked like the middle cusp, with a few prominent longitudi- |
Wt nal carine.

This is a remarkably neat little species, clearly distinct from any with which |
it is associated, or that have been heretofore described. It is related, however, :
i) to ©. Hibberti, Ag., from the limestone of Burdie House, but in that species
: the lateral cusps are much more unequal in size, and, like the principal cone,
are finely and evenly striated from base to summit.

There is another small, compressed, sparsely striated species in the collec- |
oe tion, from the Coal Measures of Indiana (C. gracilis, Nob.), but in that the |
central cusp, though compressed, is narrower, and the lateral ones are long,
curved and cylindrical. .
| Figure 13, 13 a, anterior face and base, natural size.

tt, Formation and location: Chester limestone, Chester, Illinois.

CLapopus TuRRITUS, N. and W.
{i Pl. 1, Fig. 14,

im Tren of medium size, higher than long; base thin, flat,
e shorter, laterally, than the height of the median cone, sub-

lt elliptical in outline, wider behind than before; median cone
Ne conical, covering more than half the base, sigmoidally curved,
by the point turned forward, compressed, with cutting edges,

: anterior and posterior faces unequally arched, and often flat-
tened along the median line, producing an angular section,
both faces finely striated, striation of posterior surface strongest;

at lateral denticles one on either side, with a rudimentary tubucle
HA between it and the principal cone, nearly vertical, compressed,
ig i} acute, striated, and curved in the same way as the median cone.
j i . : . : .

iH The typical form of this species, represented by Fig. 14, in the narrow, con-
ay ical and rigid outline of the central and lateral cusps, resembles a miniature
bat

A

na

+ »

VERTEBRATES. 29

spire with two flanking pinnacles, a resemblance which has suggested the name
given it. The relative length of the base is less than in any other described
species, unless in C. micropus, which, though smaller, more curved, and with
less developed lateral denticles, is otherwise not unlike it.

Figure 14, anterior face and section of median cone, natural size.

Formation and locality: Keokuk limestone, Warsaw and Nauvoo, Llinois.

CLADODUS GRANDIS, N. and W.

Pl. 1, Figs. 15, 15a.

TrETH very large and robust; breadth 13 times the height;
base thick and flat, anterior border excavated by a broad sinus
beneath the median cone, and marked with numerous fine,
sharp, vertical carinee anterior to the bases of the lateral den-
ticles; median cone robust, acute, somewhat flattened through-
out, especially on the anterior face, upper two-thirds with a
lenticular section and cutting edges, basal half of anterior sur-
face finely longitudinally striated, upper half smooth, two-thirds
of posterior surface marked with stronger vertical strie, which
converge to the base of the dorsum; summit smooth; lateral
denticles numerous (5-8 on either side) and very unequal in
size; exterior pair one-fourth the length of the principal cone,
conical and strongly striated at base, compressed and smooth
at summit; intermediate ones sub-equal, very small, striated.

This is the largest tooth of the genus yet discovered, and must have formed
the armament of a fish of formidable dimensions and prowess. In one specimen
the principal cone, now somewhat mutilated, must have been 12 inches in length;
in another, nearly entire, the median cone is 1 inch, 1 line in length; the base
1 inch, 8 lines broad.

From all species hithereto discovered this is readily distinguishable. Ap-
proaching, by its general aspect and fine striation, most nearly to C. Milleri, Ag.,
it is widely separated from that species by the compressed form and trenchant
edges of the median cone and the greater number and marked inequality of the
lateral denticles. Of the species with which it is associated in the collection,
C. magnificus, Tuomey, (if we have correctly identified that species), is most like
it in general aspect and nearly equals it in size; but in C. magnificus the prin-

30 PALEONTOLOGY OF ILLINOIS.

cipal cone is much less compressed, is more strongly and generally striated and
the strix are of very different character. In GC. grandis they are fine, acute
and often broken and forked, while in C. magnijicus they are stronger, flattened,
nearly continuous and parallel. The lateral denticles, too, in C. magnijicus are
nearly smooth, while in C. grandis they are rendered angular by the strong
though few strie, which they bear.

Fig. 15 represents the anterior face of a nearly perfect tooth; 15a, a perfect
base of a smaller specimen—both of the natural size.

Formation and locality: Chester limestone, Chester, Illinois.

5

Ciapopus Lamwnorpss, N. and W.
Pl. I, Figs. 16, 16a.

Tretu small, height exceeding length of base; base narrow,
straight before, arched behind, relatively thin, smooth; median
cone narrow, conical, recurved or often doubly curved, slightly
rounded before, strongly so behind, very acute at point, with
cutting edges which extend to near the base; anterior surface
smooth; posterior face finely striated longitudinally, except

near the point, which is smooth; lateral denticles two, one-

fourth the length of the principal cone, sub-cylindrical, acute.

This is a remarkably neat and graceful species; in form not unlike the teeth
of some of the living species of Zamna. When showing only the anterior sur-
face of the tooth, it might be mistaken for C. politus; but in that species the
base is broader, the lateral denticles are double on either side, and are not set
on the margin of the base.

Fig. 16 represents the posterior surface, with a section of the median cone;
Fig. 16a is a side view of same tooth—both natural size.

Formation and locality: Keokuk limestone, Warsaw and Nauvoo, Illinois.

CLADODUS GRACILIS, N. and W.
Pl. I, Fig. 17.

TxeTu small, delicate and slender in all parts, height about
equal to breadth; median cone narrowly conical in outline,

VERTEBRATES. 31

acute, compressed, with sharp lateral edges, anterior surface
flattened, middle and basal portions marked with a few coarse,
somewhat irregular, sharply prominent strize, summit smooth;
lateral denticles two on each side, long, slender, nearly cylin-
drical, coarsely striated, and, like the median cone, slightly
curved backward.

It is to be regretted that this very peculiar species is not represented in the
collection by more than a single specimen, as it presents some singular anoma-
lies of form. The median cone is much compressed, with cutting edges from
summit to base, while the lateral cusps are relatively very long, nearly equal in
size, and with a circular outline. They are not unlike C. costatus in the form
of the central cusps, yet the striation 1s more irregular. The lateral denticles
are much longer and more slender and widely different, in their section.

Fig. 17, anterior face and section of median cone; natural size.

Formation and locality : Coal Measures, Posey county, Indiana.

SYNOPSIS OF PETALODONT GENERA.
Family PETALODONTID A, N. and W.

TEETH compressed, transversely elongated, crown with ante-
rior and posterior surfaces enameled, meeting above in a more
or less acute-angled edge, bordered below by imbricating folds
of enamel, which encircle the crown; anterior crown-face
generally convex; posterior, concave; root more or less devel-
oped, sometimes large, sometimes nearly obsolete, bony, rough,
tumid.

1. Genus PETALODUS, Owen.

“TEETH transversely elongated, much compressed, thin, petal-
shaped, cutting edge serrated; base of crown, with several
narrow imbricating folds of enamel, descending lower on the
posterior than anterior face; root large, oblong, thin, truncated
below; lower edge obtuse, tumid.” :

32 PALAONTOLOGY OF ILLINOIS.

The difficulties which stand in the way of any attempt to establish generic
and specific distinctions, among extinct plagiostomous fishes, from the teeth as

they are usually found, detached from their connections and scattered through.

the rock containing them, are strikingly illustrated by the group of Petalodoid
teeth before us. :

This collection embraces nearly one hundred specimens, in various states of
preservation—many of them beautifully perfect—which exhibit modifications
of a common type of form, and, so far as they have been been examined micros-
copically, a common structure; and yet it is quite impossible to bring them all
within the limits of any one of the allied genera established by Owen, Agassiz
or McCoy. Selections may be made from them distinctly representing Petalodus,
Polyrhizodus, Chomatodus, etc.; but with these are intermediate forms, which
serve as connected links between the others, and make it difficult, if not impos-
sible, to break the series up into satisfactory and well defined generic groups.
Doubtless if we could have for study the entire organism now so dimly shadowed
forth in these numerous, variable and disconnected teeth, we should find in the
form, in the complete dentition or in other organs—the fins, the spines, the
bronchial openings, ete.—characters by which the group of fishes here repre-
sented might be arranged in a large number of well defined genera, the commu-

nity of form and structure which their teeth exhibit would probably then be.

shown to be a family, and not a generic character.

P. Hastingsi, Owen (type). Sub-carboniferous, Hurope.
P. acuminatus, Ag. Sub-carboniferous, Europe.

P. destructor, N. and W. Coal Measures, [linois.

P. linguifer, N. and W. Sub-carboniferous, Ilinois.

P. alleghaniensis, Leidy. Coal Measures, Penn. and Ohio.

2. GzEnus PETALORYNCHUS, Ag.

TrrtH small; crown compressed, thin, concavo-convex petal
shaped, relatively higher and narrower than in Petalodus ; im-
bricating folds on posterior face forming a short, transverse
band, not extending to the lateral angles of the crown; root long,
undivided.

S. sagittatus, Ag —name only—(type). Sub-carb., Hurope.

P. psittacinus, Ag. —name only. Sub-carboniferous, Europe.

P. striatus, N. and W. Sub-carboniferous, Illinois.

VERTEBRATES. eo

3. Genus CTENOPTYCHIUS, Ag.

TEETH small; crown as in Petalodus, but upper margin serrate,
crenulate or oaiate: root oblong, rounded, entire.

Ct. seriatus, Owen (type). Sub-carboniferous, Europe.
Ct. apicalus, Ag. Sub-carboniferous, Kurope.
Ct. semicircularis, N. and W. Coal Measures, Indiana.

£. Genus ANTLIODUS, N. and W. _

TEETH transversely elliptical, compressed, concavo-convex ;
crown similar to that of Petalodus; root short or obsolete.

A. mucronatus, N. and W. Sub-carboniferous, Illinois.
A, parvulus, N. and W. Sub-carboniferous, Illinois.
A. similis, N. and W. Sub-carboniferous, [linois.

A. cucullus, N. and W. Sub-carboniferous, Illinois.
A, politus, N. and W. Sub-carboniferous, Illinois.

A. minutus, N. and W. Sub-carboniierous, Illinois.
A. simplex, N. and W. Sub-carboniferous, Ilinois.

A. sulcatus, N. and W. Sub-carboniferous, Illinois.

A. robustus, N. and W. Sub-carboniferous, Illinois.

Probably Chomatodus truncatus, Ag., (McCoy Brit. Paleoz.
Foss., p. 618, pl. 3¢, fig. 1) and Chom. linearis, Ag., the speci-
men figured Poiss. Foss. Atlas, pl. 12, fig. 5, should be included
in this genus.

5. Genus DACTYLODUS, N. and W.

Crown as in Petalodus; root Gog TOT: and divided into a
number of radicles.

D. princeps, N. and W., (type). Sub-carboniferous, Illinois.
D. lobatus, N. and W. Sub-carboniferous, Ilinois.
D. inflecus, N. and W. Sub-carboniferous, Illinois.

PALMONTOLOGY OF ILLINOIS.

D. digitatus, N. and W. Sub-carboniferous, Minois.) feng

tt pes Senne, x

“( Ctenopt ychius digitatus, Leidy.) J. OBR, ol

6. Gznxus POLYRHIZODUS, McCoy.

Crown having general structure of Petalodus, but much more
elongated, transversely lower, and relatively thicker, as in
Chomatodus ; root divided into numerous short, robust radicles,

P. magnus, McCoy, (type). Sub-carboniferous, Gt. Britain.
P. porosus, N. and W. Sub-carboniferous, Illinois.

P. dentatus, N. and W. Sub-carboniferous, [linois.

P. ponticulus, N. and W. Sub-carboniferous, Ilinois.

(P. pusillus, McCoy, is a Helodus.)

7. Genus CHOMATODUS, Ag.

TrETH transversely much elongated, compressed and de-
pressed, crown having the homologous parts of Petalodus and
the form and structure of Polyrlizodus; root short, sometimes

obsolete, wndivided.

“tak = = r Sito. 5 :

en

ao ors

Ch. linearis, Ag. (type). Sub-carboniferous, Europe.
Ch. gracillimus, N. and W. Sub-carboniferous, Illinois.
Ch. cultellus, N. and W. Sub-carboniferous, Illinois.
Ch. loriformus, N. and W. Sub-carboniferous, Ilinois.
Ch. molaris, N. and W. Sub-carboniferous, Illinois.
Ch. pusillus, N. and W. Sub-carboniferous, Illinois.
Ch. affinis, N. and W. Sub-carboniferous, Ilinois.

Ch. angularis, N. and W. Sub-carboniferous, Illinois.
Ch. multiplicatus, N. and W. Sub-carboniferous, Illinois.
Ch. elegans, N. and W. Sub-carboniferous, Ilinois.

Ch. venustus, Leidy. Sub-carboniferous, Illinois.

>~

>

~

VERTEBRATES. 30
Genus PETALODUS, Owen.

PETALODUS DESTRUCTOR, N. and W.
Pl. I, Figs. 1 and 3.

Trretu large; crown sharped, compressed, more or less arched
laterally, rhomboidal in form, with curved outlines, somewhat
acumenate at apex; cutting edge very sharp, crenate; ante-
rior face smooth and polished, broadly rhomboidal, lateral
angles very acute, upper one slightly rounded, lower one broadly
so; posterior surface one-third to one-half higher than anterior
face, smooth and polished, terminating below, like the anterior
surface, in a band of 5-6 imbricated folds, which are broader
and more strongly marked behind than before; root nearly
smooth, broad, and compressed above, narrowed and thickened
below, where it is rounded, and deflected forward; posterior
face about the height of the posterior face of curve; anterior
face one-third higher.

Entire length of a large specimen, 2 inches, 3 lines; height
of posterior surface of crown, including basal folds, 1 inch, 3
lines; of anterior surface, 9 lines; breadth, 1 inch, 9 lines;
length of root, anterior surface, 1 inch, 6 lines; of posterior
face, 1 inch. .

These large and fine teeth, as will be seen by reference to the figures given,
must have formed the dental armament of one of the most formidable of the
Carboniferous Placoids, and the equal in‘size and prowess to the gigantic Sau-
roids of that age.

In some specimens, included in the collection, the crown is an inch in height
by one and a half inches in breadth—equaling in size the teeth of the largest
living species of Carcharias, while the root, comprising half the tooth, buried
in the integuments, must have given to the trenchant crown a firmness and
efficiency far greater than that of any of the modern shark’s teeth, which have
only a short’ tuberous base.

Some of the specimens show much wear, but still retain the sharpness of
cutting edges. This would seem to show that the teeth of the opposite jaws
shut together like a pair of shears, and the attrition which they suffered served
only to keep them in order.

i
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ie
uM

36 PALEONTOLOGY OF ILLINOIS.

The general form of the crown varies much in some instances; as in that
represented in Fig. 3, it is only half the usual height. In other respects, no
difference is discernable between that and the others; and there is scarcely
room for a doubt that both forms belonged to the same species, possibly to the
same individual, the difference being due to the place held by the different
teeth in the series, with which each jaw was furnished.

The striation of the edge is usually very distinct and regular. It is pro-
duced by the exposure of the calciguous tubes of the enamel, which are
arranged in a series directed toward the edge, and are here much larger than
elsewhere. In unworn teeth the striz are very short, the tubes of the anterior
and posterior surfaces being exactly opposite; their points of junction forming
depressions on the edge. The crenulation thus produced, is, in young teeth,
beautifully regular; in older and worn ones it becomes irregular and at length
obsolete. When the polished enamel coating of the anterior and posterior
faces is worn off, a dotted surface is exposed similar to that of Psammodus.
This appearance is due to the cutting across of the calciguous tubes, which
appear to be set here at right angles to the surfaces. These dots are particu-
larly noticeable on the basal folds in worn specimens.

The interior of the tooth is quite dense and hard, but exhibits an irregular
cellular structure. The root is more spongy, and in some cases scems to have
been imperfectly ossified.

The described species of Petalodus, to which this is most like, are P. acumi-
natus, Ag., (Poiss. Foss. Vol. 3, pp. 108,174, 7.19, f 11-13), (McCoy, Brit.
Palzxozoic, Foss. p. 635, Pl. 3 g, Fig. 4), and P. Alleghaniensis, Leidy. (Jour.
Acad. Nat. Sci. Phila., 2d series. Vol. 3, p. 161, Pl.16, 74,5 and 6.) The one
from the Carboniferous limestone of England, and the other from the Coal
Measures of Pennsylvania. From the first it differs in the greater relative
height of the crown, and the longer and narrower root. From the second it is
possibly not specifically distinct, as we only know that through the single speci-
men figured and described by Dr. Lurpy. If that specimen is a fair represen-
tation of P. Alleghaniensis, our species may be distinguished from it by its
crown, which is more pointed above, and much less arched laterally; and by
the root, which is longer and narrower. It should be said, however, that we
have every reason to believe that the teeth of Petalodus, from the different
portions of the mouth, are considerably different in form, and it is not at all
unlikely that the discrepancies between Dr. LiEpy’s specimens and ours will
prove to be insufficient grounds on which to establish a specific distinction.

Figures 1, 1 a, and 2, 2a, represent anterior and posterior views of the
crowns of two mature teeth; 2 6, the root anterior surface ; 2c, profile section;
Fig. 3, a small and low crown anterior face, all natural size.

Formation and locality: Coal Measure limestones of Springfield, LaSalle
and Sugar creek, Illinois.

VERTEBRATES. ae

PETALODUS LINGUIFER, N. and W.
Pl. Il, Figs. 4,4 4,46, 5,5 4,50, 5c.

TretH large, broader than high; crown three times as broad
as high, straight or very slightly arched laterally, cutting edge
broadly and nearly evenly arched, apiculate at the summit,
strongly striated before, less so behind, finely crenulated; ante-
rior surface very broadly rhomboidal, highly polished; basal
imbricated folds narrow; posterior face slightly higher than
anterior, like that broad, rhomboidal in outline, smooth and
highly polished, much arched vertically, very slightly so later-
ally, bordered below by a broad band of 7-8 imbricating folds
of enamel; root smooth except where peirced by the nutrient
vessels, accurately tongue-shaped, rounded below, posterior face
equal in height to the posterior face of the crown, including
basal folds; anterior face one-third the higher. Total height
of tooth, 12 lines; breadth, 18 lines.

In the form of the crown, these teeth bear considerable resemblance to those
of P. acuminatus, Ag., but differ in having the upper lines of their rhombic
outline convex instead of concave ; the root, too, is less wide. In P. acuwmina-
tus—as would appear from the figures of Agassiz and McCoy—it is as broad
where it unites with the crown, as the crown itself; while in P. linguifer it is
much narrower, and is precisely of the form of the terminal half of the human
tongue. In the very beautiful and perfect specimen from Pope county, (Fig.
4), the tongue-like root is broader than in those from Chester, (Figs. 5, 5c),
but is still much narrower than in the described specimens of P. acuminatus.

It is, perhaps, possible that the Chester specimen should constitute a distinct
species, but with the exception of the difference in the form of the root, they
seem to be alike.

It will be seen from the sections given (Figs. 5 b, 5 c) of two specimens
from the Chester limestone, that they show a marked difference in the relative
height of the crown, but this is a character which is particularly inconstant in
all the species of Petalodus.

Figures 4 and 4a, a perfect specimen from Pope county, seen from behind
and above; 4 6, section of same; 5,5 a and 5 8, anterior and posterior faces,
and section of a worn specimen from Chester; 5 ¢, profile section of another
Chester specimen.

Formation and locality: Chester limestone, Chester and Pope county, Illinois.

™

j
Hs

38 . PALEONTOLOGY OF ILLINOIS.
Genus ANTLIODUS, N. and W.

ANTLIODUS MUCcRONATUS, N. and W.
Pl. II, Figs. 6, 6 a,60.

TEETH small, robust, broader than high, posterior crown face
lenticular in outline, with very sharp angles, concave vertically
and laterally, smooth or very finely striated vertically under
the lens; superior border regularly arched, finely crenulated ;
basal folds about 5, upper one nearly equaling the lower four
in breadth, forming a narrow, prominent, bow-shaped ridge;
anterior surface equal in height to posterior, strongly arched
laterally, vertically concave below, arched above; basal ridge
a sharp prominent angle, without distinct folds; base arched
laterally, strongly concave vertically, smooth; root two-thirds
as wide as the crown, apparently divided into several radicles.

A very distinct and neat species, characterized by its low, thick, and strongly
arched crown, terminating laterally in very acute depressed points.
Figures 6, 6 a, 6 6, represent front and rear views, with profile, natural size.

Formation and locality: St. Louis limestone, Alton, Illinois.

ANTLIODUS PARVULUS, N. and W.
Pl. Il, Figs. 7, 7a.

TretH small, elliptical in outline, height two-thirds the
breadth; cutting edge regularly arched, crenulated; anterior
surface of crown just half the height of the tooth exclusive of
the rudimentary root, smooth and polished, except along the
upper border, where it is striated, terminating below in a bow
shaped coronal ridge; posterior surface concave, higher than
anterior, smooth: with the exception of the strize along the
cutting edge; root nearly obsolete, existing only as a narrow
fringe below the central two-thirds of the crown. Height 4
lines; breadth 6 lines.

VERTEBRATES. 39

This elegant little species resembles, in size and outline, A. minutus, but is
readily distinguishable from it by its discernible, though small, root, and the
greater relative height of the anterior face of the crown—differences distinctly
shown in the profiles of the two species.

Figures 7 and 7 a, represent, respectively, the anterior and posterior faces,
and the profile, natural size.

Formation and locality: Burlington limestone, Quincy, Llinois.

ANTLIODUS ROBUSTUS, N. and W.
Plate Ii, Figs. 9, 9a, 9b, 9c.

Trretu of medium size, thick and massive, much broader than
high; crown twice as broad as high, upper margin regularly
arched, somewhat rounded, obtuse and porous; anterior surface
semi-elliptical, half the height of tooth, regularly arched verti-
cally and laterally, smooth and polished, in its normal state,
except along the upper margin, where it is striated by the ex-
posed enamel tubes; below these tubes inosculate, producing a
reticulated, still lower a dotted porosity; anterior coronal ridge
narrow, bow-shaped, prominent, and showing several folds of
enamel; posterior surface smooth, regularly concave in both
directions, one-third higher than anterior face, exclusive of the
broad coronal ridge, which is arched downward or slightly bow-
shaped, showing 5-6 distinct imbricating folds, of which the
upper one is much the broadest; base nearly smooth; root two-
thirds the entire breadth of the tooth, very short, slightly pro-
jecting below the posterior coronal ridge, tubercled or rough-
ened, not divided.

This, and the other species of the short-rooted group of Petalodonts, to which
it belongs, exhibit the singular feature of a crown which is essentially that of
the typical species of Petalodus, but having the root, so conspicuous in those
species, dwarfed to a mere tuberculated ridge, set on the base, as in the present
species, A. parvulus, A. cucullus, ete.—or still more rudimentary or wholly
wanting, as in A. simplex and A. minutus.

That this departure from the normal type, in the form of the teeth, was asso-

40 PALAONTOLOGY OF ILLINOIS.

eiated with various other modifications of the structure of the fishes to which
they belong, by which their whole economy was changed, there can be no doubt.
We have, therefore, felt justified in placing them in a generic group by them-
selves.

Figs. 9, 9a, 9b and 9c represent the anterior and posterior surface, side view
and profile of a large specimen from the Chester limestone.

Formation and locality: Chester limestone, Chester, Illinois.

Genus PETALORHYNCHUS, Ag.

PETALORHYNCHUS STRIATUS, N. and W.
PI. I, Figs. 8, 8a, 8 6.

Trretu small and thin; crown sub-pentagonal iu outline, flat
or slightly arched laterally, summit sloping either way to two
lateral angles where the tooth is broadest, thence the sides con-
yerge to the basal folds; cutting edge sharp, finely and rather
irregularly crenulate ; anterior surface slightly less high than
the posterior, central portion raised into a broadly rounded
vertical ridge, bordered by parallel shallow depressions, upper
two-thirds uniformly marked by fine vertical or divergent
striz, showing the courses of the calcigerous tubes, which are
somewhat branched; basal folds few, (2-3), strong mesial
angle turned up instead of down; posterior surface plane,
slightly curved backward at the base, smooth below, striated
above; imbricated folds at base 2-3, broad, nearly straight, and
horizontal; root unknown.

/

This unique and pretty species bears a distinct resemblance to P. sagittatus,
Ag. (McCoy Brit. Palacoz. Foss. p. 636, Pl. 3%, fig. 2, 3), but may be readily
distinguished from it by its thin, flat crown, sodistinctly and JBau ely striated;
the reversed basal angle of the anterior ae ete.

Figures 8, 8 a, 8 b, are views of the front and rear faces of the crown, and
section, all natural size.

Formation and locality: Burlington limestone, Quincy, Illinois.

VERTEBRATES. 4]

ANTLIODUS simiLis, N. and W.
Pl. II, Figs. 10, 10a.

TrrTH rather small, thick and strong; crown twice as broad
as high, upper margin regularly arched, obtuse or sub-acute;
anterior surface semi-elliptical, not quite half the height of the
tooth, arched both vertically and laterally, smooth and polished
except where worn; upper margin striated, lower slightly bow-
shaped; posterior surface rather more than twice the height of
the anterior, curved in both directions; lower margin marked
with fine, imbricating folds, and forming a thin, prominent
edge; root short, thick.

: This species approaches very nearly, in form, to A. robustus, but is smaller,
and the angle formed at the edge of the crown, by the anterior and posterior
surfaces, is larger, giving to the tooth, as it stands vertically, a somewhat flatter
top. This difference is most clearly seen in the profile sections of the two

species. The root also projects more anteriorly. So like, however, are the two
species, that if they had been found at the same geological horizon, they would
with propriety have been considered mere variations in form, of one and the

same species. P
Figs. 10 and 10a represent the anterior face and profile section of the nat-
ural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

ANTLIODUS CUCULLUS, N. and W.
Pl. III, Figs. 1, la, 10.

Tretu of rather large size, robust, elliptical in outline, much
broader than high, superior border regularly arched, thickened,
rounded, striated and obtuse; posterior face of crown sub-ellip-
tical, smooth, terminated below by a broad, flattened coronal
ridge, which is arched downward and marked indistinctly with
imbricating folds; anterior face of crown lenticular in outline,
half the height of posterior face, regularly arched laterally,
terminating in long, acute points, slightly concave vertically,

—6

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42, PALAONTOLOGY OF ILLINOIS.

bounded by prominent ridges, one formed by a thickening of
the superior border, the other the basal ridge. The latter is
slightly bow-shaped and faintly marked with parallel folds;
base very smooth, slightly arched laterally ; root three-fourths
the breadth of crown, very short, scarcely reaching the lower
border of the posterior coronal ridge, rough and irregular,
somewhat divided into rudimentary radicles.

This species resembles, in its general aspects, A. robustus, but is readily dis-
tineuishable from it by its thickened edge, its concave anterior face, broader
base, shorter root, etc. Its profile, nearly that of the ladies’ bonnets now in
fashion (1860), has suggested the name given it.

Figs. 1, la, 1b represent both faces and profile, natural size. _

Formation and locality: Keokuk limestone, Nauvoo, Illinois. °

ANTLIODUS PoLiTuS, N. and W.
Pl. Ill, Figs. 2, 2a.

TrEtH small, thick, exceedingly hard and dense, elliptical in
form; superior border of crown regularly arched, truncated and
slightly furrowed; posterior surface smooth and polished, ellip-
tical in outline, concave vertically, straight laterally; coronal
folds numerous, broad, flat, evenly arched downward; anterior
surface lenticular, long-pointed laterally, one-half the height
of the posterior surface, straight or slightly curved vertically,
arched laterally; anterior coronal ridge sub-acute, narrow,
prominent, and marked with several fine, parallel, enamel
folds; base sub-elliptical in outline, smooth; root rudimentary,
forming a prominent tuberculated ridge as long as half the
breadth of the tooth, set in the base near its lower border;
under the lens the structure appears very dense and close
throughout, a few pores opening along the borders of the supe-
rior marginal sulcus.

This, and the closely allied A. sulcatus, are among the most interesting species
represented in the collection. Their relations to some of the nearly rootless

VERTEBRATES.. 43

forms which we have described, such as A. cucullus, etc., are close, as is evinced
by their general resemblance of form and the perfect correspondence in all their
homologous parts; but in A. politus the thickened edge of those species with
which we have compared it is truncated and even sulcated, the margins of the
sulcus being composed of denser tissue and wearing less rapidly. The office of
the tooth was plainly that of a grinder, the triturating surface being fitted for its
duty as in the ruminants, rodents, pachyderms, ctc., by the alternation of harder
with softer bands of dental tissue.

The entire tooth is excessively hard and dense, showing an interesting adap-
tation to the purposes it was intended to subserve.

Figs. 2, 2@ represent the posterior aspect and profile of an average sized
tooth, natural size.

. Formation and locality: Keokuk limestone, Warsaw and Nauvoo, Illinois.

ANTLIODUS mINUTUS, N. and W.
Pl. Ill, Figs. 3, 3a, 3b.

TEETH very small and thin; root rudimentary or obsolete;
crown elliptical in outline, cutting edge uniformly arched and
finely crenulated; posterior surface occupying half the height
of the tooth, concave vertically and horizontally, smooth and
polished throughout except along the superior margin, where
it is striated to the cutting edge; posterior basilar imbricated
folds 4-5, distinctly marked and occupying the lower half of
the posterior surface; anterior face of crown very narrow, form-
ing scarcely more than one-fourth of the antero-inferior surface,
inclined to the inferior surface at an angle little greater than a
right angle, smooth and polished, terminating below in a single
prominent basal ridge, which is arched parallel with the cut-
ting edge; inferior surface of the tooth roughened for its attach-
ment to the integuments, and showing, in a few low tubercles,
the rudiments of the root; length 6 lines; height 3 lines.

This beautiful little tooth is remarkable for the entire absence of a root. It
seems to have been attached to the jaw by a roughened surface, occupying the
interval between the anterior and posterior coronal folds, which are very widely
separated. The character would exclude the species from the genus Petalodus,

44 PALEONTOLOGY OF ILLINOIS.

as defined by Owen; but with that exception there could searcely be a more
perfect type.

Of the figures given, figure 3 represents the posterior surface, natural size;
3a the same, enlarged to two diameters; 36 profile or section through the cen-
ter of tooth, also twice the size of nature.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

ANTLIODUS SIMPLEX, N. and W.
Pl. Ill, Figs. 4, 4a.

TretH small, long-elliptical in outline, superior border arched,

acute, striated on the anterior side, dotted posteriorly; posterior
face, long-elliptical, smooth and porous throughout, slightly
arched virtically, laterally straight, bordered below by a narrow
and low coronal ridge; anterior surface half the height of pos-
terior, nearly straight vertically, and in the central portion
laterally, toward either side regularly arched, upper two-thirds
finely striated vertically; anterior basal ridge low, simple, nearly
straight; base occupying half the anterior aspect of the tooth,
slightly arched both ways, inclined at right angles with the
anterior face of crown, roughened in the place occupied by the
root in the species; root, none.

The only specimen of this species in the collection is somewhat worn, but is
sufficient to indicate its entire distinctness from all others described. The
posterior face has been exposed to long wear, when on the jaw, and the normal
character of this surface can hardly be deduced from it. It is now regularly
dotted all over with the ends of the enamel tubes, precisely as in Psammodus.
As has been mentioned, all the Petalodonts, when much worn, present some-
thing of this appearance. In this species it is more marked, however, than in
any other, and evidently depends on a peculiarity in the microscopic structure
of the crown. The cutting edge is quite thin, and the porosity of its posterior
surface is occasioned by the uniform direction of the enamel tubes. These are
set parallel with the slope of the anterior face, marking that face with vertical
striz, but dotting the posterior face with their ends cut obliquely.

Fig. 4 represents an anterior view of tooth; Fig. 4a, a profile section—both
natural size.

Formation and locality: Burlington limestone, Burlington, Iowa.

VERTEBRATES. 45

ANTLIODUS suLcATUS, N. and W.

Pl. Il, Fig. 5, 5 a.

Trrtu of medium size, broad, thin, flattened, with an ellip-
tical outline; posterior face long, elliptical, smooth, less than
half as high as broad, slightly concave vertically, laterally
straight, superior margin regularly arched, truncated, and
slightly sulcated, sulcus about one-sixth the height of the face,
its posterior margin lowest, both margins porous and roughened
by the terminations of the vertical enamel tubes ; coronal ridge
regularly curved downward, narrow, not prominent, showing
about three imbricating folds; posterior face broader than ante-
rior, elliptical in outline, very slightly arched vertically and
horizontally, rough; coronal ridge wanting; base narrow and
roughened with the rudimentary root.

Much like the preceding species in general aspect but broader, thinner and
more distinctly sulcate; anterior face more flattened.
Figures 5, 5 a, represent the posterior face and section, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

Genus DACTYLODUS, N. and W.

DactyLopus princers, N. and W.
’ Pl. III, Figs. 6, 6¢, 66.

Trrta large and robust, slightly higher than broad; superior
border of crown regularly arched, obtuse and porous; anterior
face three-tenths of the height of the tooth, sloped downward
at an angle of about 30°, to an obtuse transverse ridge, surface
smooth and gently arched horizontally ; posterior face imper-
fectly elliptical, nearly flat, smooth, in weathered specimens
more or less porous, about twice as high as the anterior face,
bounded below by a thick coronal ridge, obscurely marked with
imbricating folds. This ridge is somewhat bow-shaped, termi-

>

46 PALZONTOLOGY OF ILLINOIS.

nating in the prominent lateral angles. The root is large and
thick two-thirds the breadth, and nearly the height of the
crown. Its posterior face is flattened, the anterior slightly
arched both ways. It is divided nearly to the crown into five
finger-like rootlets, of which the two external ones are shortest
and most robust.

These remarkable teeth differ widely from any hitherto described, in the long
fangs in which the root terminates; in this respect being more like the teeth of
mammals than fishes. The crown, however, is essentially that of Petalodus,
and there can be no doubt that they once belonged to a plagiostomous fish of
the same family as the typical Petalodi.

Prof. McCoy has described some petalodont teeth, from the same horizon
with these, under the name of Polyrhizodus, which also have roots divided into
several fangs ;and other similar species will be found represented in Pl. 111, and
described in the following pages. As will be shown hereafter, MeCoy’s Poly-
rhizodus has much in common with Petalodus. This affinity is also indicated
by the species before us, and D. lobatus, both being still more like fhe teeth on
which Owen founded his genus Petalodus; and yet they have larger and more
distinct fangs. : i

The only specimen of D. princeps in the collection is, unfortunately, some-
what worn and weathered, and its external surface has been in part removed.
It is, therefore, impossible to decide from that alone, whether in its normal state
it exhibited any decided departure from Petalodus. It now shows near the
summit of the crown a more porous structure than most species of that genus
in their perfect condition. As has been remarked, however, in the description
of Petalodus destructor, where the cutting edge of the crown is much worn,
and the polished enamel coating of either face is removed, nothing but a dotted
porous surface is seen; the longer calciguous tubes which compose the edge
being removed or worn down, so that both there and below their ends alone are
visible.

As has been suggested. in the remarks on the genus Petalodus, we have
scarcely satisfactory data on which to divide the petalodont teeth into different
genera; the typical species, the many rooted, the small rooted and the rootless
groups, all exhibiting among themselves nearly the same range of microscopic
structure; this variation, when existing in perfect teeth, following their forms
and consequently their uses. The broad-edged, grinding or crushing teeth of
each group exhibit, in their triturating surfaces, the homologues of the cutting
edges of the incisive forms; the series of vertical enamel tubes being greatly
widened, and the tubes shortened.

VERTEBRATES. - 47

posterior do; and 6 8, the profile section ; all natural size.

Formation and locality: St. Louis limestone, St. Louis, Missouri.

; A Ne chard —f-
DactyLopus Lopatus, N. and W. Ser ae a aaa
btm ) Vwre / ..

Pl. Ill, Fig. 7, 7 a.

TxetH rather small, thin and flattened, crown elliptical, cut- , jl ©

ting edge regularly arched, posterior face smooth, in weathered
specimens finely striated longitudinally, concave vertically,
nearly straight horizontally; anterior surface two-thirds as high
as posterior ; posterior coronal ridge formed by the imbricating
folds, bow-shaped, prominent, folds numerous, (5-6), sharp, fine
and parallel; root half the height and half the breadth of
crown, three lobed, iateral lobes acute, middle one larger and
emarginate. Height9 lines; breadth 10 lines; height.of crown,
including basal ridge, 6 lines; of root 3 lines.

The single specimen of this species contained in the collection, seems to be
another connecting link between Petalodus of Owen, and Polyrhizodus of
McCoy. The crown is apparently precisely that of a Petalodus, and the root,
in its general form, is not unlike that of some Petalodi, except that it is deeply
lobed. A tooth, generically, and it is possible, specifically, identical with the

one before us, has been described by Prof. Leidy under the name of Ctenopty-

chius digitatus. (Trans. Amer. Philos. Soc., Vol. XI, p. 90, Pl. 5, figs. 27, 28,
29). Judging from the figures and description only of that tooth, we should
say it was less symmetrical, the edge of the crown less thin and acute, the root
longer and broader than in ourspecimens. These differences may prove, how-
ever, to be dependent on the places which they occupied in the mouth.

The peculiar and abnormal character of these teeth is strikingly illustrated
by the fact that an anatomist of so great learning, and so proverbially accurate,
as Dr. Leidy, should have reversed one of them, and have described as the
crown, what is shown by the three well marked and closely allied species before
us, to be the root.

Figures 7 and 7 a, represent the posterior face and section, natural size.

Formation and locality: St. Louis limestone, Alton, Illinois.

The figures given of D. princeps represent (6) the anterior face; (6 a) the is

ne
ni
um

.

a
~ omer
5 t CA" Nae
a

™
Lt Powel

48 PALAMONTOLOGY OF ILLINOIS.

DactyLopus INFLEXuS, N. and W.
Pl. Ill, Figs. 8, 8a.

Trrta of small size, slightly broader than high; crown
equaling the root in height; cutting edge sharp, regularly
arched, unevenly striated and crenulated by the somewhat
irregularly disposed marginal enamel-tubes; posterior face
elliptical, strongly concave vertically, nearly straight laterally;
anterior face throughout all its central portion plain and
smooth, long-rhomboidal in outline, the upper and lower angles
rounded symmetrically, the lateral ones long-poimted, the
points being abruptly curved backward and downward to join
the coronal ridges. This face of the crown is much elevated,
forming an acute angle with the base; the anterior ridge divi-
ding the crown from the base is prominent, but like the spaces
bordering it very smooth. When worn, the anterior face of
the crown shows near the upper border a somewhat reticulated
porosity produced by the cutting across of the oblique enamel
tubes. The root is flat, somewhat constricted at its junction
with the crown, but expanded below and divided into 5-6"
divergent and conspicuous radicles. :

Though sufficiently distinct from the two preceding, this species is closely
allied to them, forming the fourth with which we are now acquainted, of this
interesting group. Its most distinctive character is that which suggested the
specific name given it, in the strong backward inflexion of the upper part of
the crown. This gives it the appearance of having a flat summit, and of being
a grinding tooth. It has, however, a sharp, cutting edge, and its position on
the jaw must have been such that the summit of the crown was vertical or
slightly inclined toward the throat. The anterior face of the crown is worn
near the edge as though a corresponding tooth in the other jaw had matched
with this, and the two had worked together like the blades of a pair of shears.

The form and length of the root in many Petalodonts is such as to indicate
that they could have had little motion, but were probably fixed in their places,
and like these worked together in the manner of scissor blades.

Figure 8 and 8 a, represent the anterior face and profile, natural size.

Formation and locality: Chester limestone, Chester, Illinois.

VERTEBRATES. 49
Genus POLYRHIZODUS, McCoy.

PoLyruizopus porosus, N. and W.
Pl. Ill, Figs. 9, 9a.

TEETH thick and massive, twice or three times as broad as
high; posterior face of crown comprising nearly half the height
of the tooth, long-elliptical in outline, with rounded extremities,
strongly inclined backward toward the summit, very slightly
concave both vertically and laterally, smooth in perfect speci-
mens, marked with fine vertical striations in those that are
weathered—in such, a narrow band of pores are visible along
its lower margin; coronal imbricating folds forming a broad,
flattened band, nearly as high as the crown face, laterally
straight except near either end, where it is suddenly curved
upward, folds three, of equal height, with two very fine lines
below; anterior face nearly horizontal, forming a triturating
surface of the same form and area as the posterior crown face,
slightly concave and lower before. In unworn specimens this
is covered with a coating of polished enamel, except at the poste-
rior edge, where it is porous; when much worn the entire surface
is distinctly porous, as in Psammodus; base as high as anterior
crown face, to which it is inclined below, smooth throughout,
convex vertically and laterally; root nearly as wide as the
tooth, directed forward and downward, and reaching but little
below the line of the posterior basal folds, divided into several
distinct radicles.

The form of the crown of these teeth is similar to that of Polyrhizodus mag-
nus, McCoy (loc. cit.), but they are smaller, have shorter rootlets, and a some-
what different profile; Prof. McCoy’s species having the lower margin of the
posterior crown face inclined backward, while in our species it is inclined
_ forward, etc.

Figures 9 and 9a represent the posterior aspect and profile of the largest
specimen in the collection, of the natural size.

Formation and locality: Burlington limestone, Burlington, Iowa, and Quincy,

Llinois.
eh

50 PALAEONTOLOGY OF ILLINOIS.

PoLyruizopus DENTATUS, N. and W.
Pl. III, Fig. 10, 10 a.

Tretu of moderate size, much broader than high, widest at
summit; posterior surface of crown linear in outline, with
rounded ends, less than half the height of the tooth, termina-
ting above in an acute, porous, cutting edge, which is nearly
straight throughout; posterior crown face somewhat concave
vertically, nearly straight horizontally ; basal ridge prominent,
half the height of the crown face, straight in its central part,
curved upward to the cutting edge at each end; anterior face
of crown nearly as high as posterior, inclined to the vertical
axis of the tooth at an angle of about 45°, straight or very
slightly arched vertically, gently arched toward each lateral
extremity, where it narrows to a point, terminating below in
an acute edge, or angle without distinct coronal ridge or folds;
base linear, as high as crown face, to which it is inclined at an
acute angle, smooth, concave vertically, arched laterally; root
thicker than crown, composed of numerous sub-quadrate radi-
cles nearly half the height of the entire tooth.

It will be noticed that this tooth has a strong family resemblance to those
we have described under the names of Chomatodus multiplicatus and C. lori-
formis, and through them is distinctly connected with the solid rooted Petalo-
donts, and yet the root is deeply, almost regularly, divided into numerous
distinct radicles. In this respect it is like the following species, more particu-
larly to the next one P. ponticulus. To P. porosus, which so closely approaches
Polyrhizodus magnus of McCoy, it is allied by its divided root, and the gener-
alities of its form; but its cutting edge and comparatively light and angular
profile, render it distinguishable from that species at a glance. With its
numerous sub-equal tooth-like radicles this tooth bears considerable resem-
blance to the jaw of some mammal with a series of attached teeth ; a resem-
blance which has suggested the specific name given it.

Figure 10 exhibits the posterior face of the tooth; 10 a, is a profile section ;
both natural size.

Formation and locality: Chester limestone, Chester, Illinois.

VERTEBRATES. out

PoOLYRHIZODUS PONTICULUS, N. and W.
Pl. Ill, Fig. 11 and 11 a. és

TrerH broad, low and thin, in outline oblong or linear; _pos-
terior surface of crown two-thirds the entire height, concave
vertically, nearly straight laterally, smooth and _ polished ;
imbricating folds forming a narrow, low basal band; anterior
face nearly horizontal, giving a flat or slightly arched summit
to the tooth, not quite half as broad as the height of the poste-
rior face; basal ridge a sharp angle without distinct folds; base
forming half the height of the anterior surface, concave verti-
cally, gently arched laterally, smooth and polished; root verti-
cal, nearly as broad as the tooth, and composing one-third of
its height, flat, thin and divided into several sub-equal quad-
rangular rootlets. Height of tooth 4 lines; breadth of a
portion only, 15 lines.

This tooth should evidently be classed in the same genus with McCoy’s
Polyrhizodusmagnus (Brit. Paleoz. Foss. p. 641, Pl. 3k, fig. 6,7, 8), but cer-
tainly not with his P. pusillus, (Op. Cit. p. 642, Pl. 3, k, fig. 2.)

From the former it differs, however, in being lighter throughout, the more
angular crown, shorter, fewer, and more angular roots. Its relations to the
preceding species, P. dentatus, are much closer, that species differing from this
only in being higher, the crown more acute above, the radicles more numerous
and much thicker. In both these species the summit of the. crown forms nearly
a straight line throughout, the basal ridge being curved up to it at either end.

Figures 11, 11 a, represent the anterior aspect and profile, natural size. As
will be noticed, this face of the tooth bears a striking resemblance to a many-
arched bridge, a resemblance which suggested the name given it.

Formation and locality: Chester limestone, Chester, Illinois.

Genus CHOMATODUS, Ag.

CHOMATODUS GRACILLIMUS, N. and W.

Pl. Ill, Fig. 12,12 a.

TEETH transversely elongated, linear in outline; posterior
crown face half the entire height with rounded ends, its upper

52 PALHZONTOLOGY OF ILLINOIS.

and lower borders being straight and parallel throughout most
of the breadth, but curved to meet at each end. The surface
slightly concave and finely striated vertically, straight later-
ally; the upper margin showing a few relatively large pores ;
basal folds 3-4, forming a flattened band little more than half
as high as the crown face; anterior surface nearly horizontal,
forming a flat top to the tooth. This is a little narrower than
the posterior crown face, lower before than behind, slightly
concave in an antero-posterior direction; base broader than the
anterior face, flat; root nearly as broad as the crown, very
short, projecting but little below the posterior imbricated folds,
more or less waved in outline, but scarcely divided.

This species bears considerable resemblance to C. loriformis in its general
aspect, but is relatively broader and lower, has the crown more rounded at the
ends, has a more nearly horizontal summit when viewed in profile, etc. It
would seem also that some of the teeth described by Prof. Agassiz. (Poiss.
Poss. Vol. 3, p. 108, tab. 12, fig. 5-12,) under the name of Chomatodus
linearis were of similar form. There are probably several distinct species,
however, included in the series represented by Prof. A., part of which should
be included in Antliodus—as Fig. 5, which is considerably like our A. parvulus,
and others perhaps in Helodus. The specimen represented by Fig. 6, (loc. cit.)
evidently represents a species closely allied to ours, though the descriptions of
C. linearis, by Agassiz and McCoy, prove it different. These represent the
crown as surrounded by a line of basal folds, while in our specimens of P. gra-
cillimus, as in all the group to which this species belongs the imbricated folds
are scarcely, if at all, visible, except on the posterior face. The profile section
of Chomatodus linearis is also quite different, the superior margin being much
sharper.

Figures 12 and 12 a@ represent the posterior aspect and section, natural size.

Formation and locality: Burlington limestone, Burlington, Iowa.

CHOMATODUS CULTELLUS, N. and W.~
Pl. III, Fig. 13, 13 a.

TrEeTH transversely elongate, thin and knife-like; central —
portions straight and flat, the ends strongly curved forward;

VERTEBRATES. 53

crown terminating above in a cutting edge which has an arched
outline, more or less undulate and porous; posterior crown
face more than half the height of the tooth, slightly concave
vertically, arched laterally at either end; posterior basal folds
about 3, forming a flattened band, half the height of crown
face; anterior crown face a little less high than posterior,
nearly straight vertically and laterally, except at the extremi-
ties, where it 1s curved forward, smooth and polished, but under
the lens showing pores throughout; basal ridge narrow, dis-
tinct, straight, except at the ends, where it is slightly turned
upward, without imbricating folds; root very nearly as wide as
crown, less than half as high undivided, but marked along its
anterior surface by a series of deep and nearly uniform pits or
depressions, separated by narrow, prominent, vertical costee ;
toward either lateral extremity the root is gradually narrowed,
and here the costz are somewhat divergent from the centre.

This species resembles the preceding one in many respects, but is readily
distinguishable by its thin, flat crown, curved at either end, and by its thin,
‘deeply pitted root.
Figures 13, 13 a, represent the anterior face of an imperfect tooth, with a
profile section, of the size of nature.

Formation and locality: Chester limestone, Chester, Illinois.

CHOMATODUS PUSILLUS, N. and W.
Pl. Ill, Figs. 14, 14a, 14 8.

TreTa small, slender, linear,. broader than high; posterior
face of crown half the entire height, linear or long-lenticular
in outline, straight laterally, concave vertically, cutting edge
sharp, fine; crenulated and more or less undulated, whole pos-
terior face striated vertically, striation stronger along the edge;
as in the typical Petalodonts; basal angle very prominent, -
showing two or three narrow enamel folds; anterior surface
equaling posterior in height, of similar outline, slightly arched

54 PALAONTOLOGY OF ILLINOIS.

laterally, more strongly so vertically, smooth and polished
throughout, but showing every where relatively large, evenly
distributed pores; basal angle a prominent ridge opposite pos-
terior one without distinct folds; root nearly as broad and high
as the crown, vertically concave anteriorly, convex posteriorly,
not divided.

In its general form this tooth approaches somewhat nearly to the three pre-
ceding species, but in the equal height of the basal ridges of the opposite
crown surfaces, and in the porous structure of the anterior face it is allied to
the Helodi, presenting an interesting link between these two genera.

Figure 14, represents the anterior aspect of a broken tooth ;.figure 14 a, the
crown seen from above; and figure 14 0, a central profile section, natural size.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

CHOMATODUS AFFINIS, N. and W.
Plate III, Figs. 15, 15 a.

Trets laterally elongated, 5-6 times as broad as high, thick
and strong; posterior crown face oblong in outline, vertically
and laterally concave, upper and lower borders nearly straight,
slightly arched together at the ends; basal folds about 4, nearly
equal, parallel and distinct, forming a prominent flattened
ridge about one-fourth the height of crown face; anterior face
linear in outline, narrowed to a point at each end, half the
height of the posterior face, to which it is inclined at an angle
of about 60°, slightly concave vertically; base very concave
vertically, slightly arched laterally, forming a broad furrow
between the root and anterior basal ridge. This furrow is
narrower in the centre than at either end, made so by the
slight arching upward of the line of insertion of the root, and
downward of the coronal ridge; root nearly as broad as the
tooth, forming only a prominent ridge not reaching down to the
lower line of the posterior coronal band.

This species is represented in the collection by much worn teeth only. These
have a marked similarity to C. angularis from the Coal Measures at La Salle,

Or

VERTEBRATES. 13)

and at first sight will perhaps not be distinguished from it; closer inspection
will, however, enable one to separate them. In C. affinis the posterior imbri-
eating folds are fewer, forming a’ narrower band which is not so distinctly
turned up at the ends. The base, too, is very much more concave.

Figure 15 and 15 a, represent the posterior aspect and section of an imper-
fect tooth, natural size.

Formation and locality: Keokuk limestone, Appanoose, Illinois.

CHOMATODUS ANGULARIS, N. and W.
Pl. III, Figs. 16, 16a.

TrEtH laterally elongate, broader than high, oblong in out-
line, thick and strong; posterior crown face little more than
half the height of the tooth; linear in outline, the superior
border straight, forming an obtuse or truncated triturating
edge, concave vertically, straight laterally, smooth below,
porous above; posterior basal folds about ten, the upper much
the broadest, forming a flattened band nearly as high as the
crown face. These folds are straight throughout all the middle
portion of the tooth, but are suddenly turned up at either end
toward the straight upper margin; anterior crown face linear,
half the height of the posterior surface, toward which it is
inclined at an angle of about 60°, concave vertically, straight
laterally; anterior basal folds about three, in a flattened ridge
half the height of the crown face; base nearly flat and smooth,
forming a plane at right angles with the anterior crown face;
on this plane the rudimentary root is placed as a prominent
ridge, not reaching down to the lower line of the posterior basal
folds.

Though closely allied te the succeeding species, C. molaris, this exhibits very
important and distinctive differences. It is more angular in all its parts. The
root is smaller, the posterior basal folds much more numerous, the angle inclu-
ded between the crown faces different, and the triturating surface is formed by
this truncated angle, rather than by the arched anterior crown surface. Its

position on the jaw must therefore have been different, and its broader surfaces
more nearly horizontal.

56 PALEONTOLOGY OF ILLINOIS.

Figures 16 and 16a represent the posterior aspect of a broken tooth and a
section, natural size.

Formation and locality: Coal Measures, LaSalle, Illinois.

CHOMATODUS MOLARIS, N. and W.
Pl. Ill, Figs. 17,.17a.

Trrty thick and strong, broader than high, outline linear or
oblong, with nearly parallel sides; posterior face of crown half
the entire height, concave vertically, straight laterally, smooth;
posterior basal folds 2-3, forming a prominent band or ridge
nearly half the height of the crown face; anterior surface nar-
rower than posterior, forming an arched summit, of which the
posterior margin is scarcely higher than the anterior; in worn
specimens it is lower; along the anterior border of this surface
is a shallow sulcus, dividing off a narrow line, which forms the
representative of the usual basal folds. The triturating surface
formed by the homologue of the anterior crown face, when
much worn, shows a few large pores, but in preparation for the
severe service to which they were exposed, the entire teeth
were exceedingly close and compact in texture, and the sur-
faces are all smooth and polished. The base is concave verti-
cally, straight laterally, strongly inclined below toward the
posterior face, giving a V-shaped section to this part of the
tooth. The root is strong but short, reaching little below the
line of the posterior basal folds.

This may be regarded as the type of a small group of species, represented in
the collection by a large number of specimens, most of which are, however,
too imperfect for description. They exhibit the petalodont type of structure
throughout, but in their laterally elongated form, their truncated summits, they
approach very nearly to the teeth of some of the rays, and it is evident that
their functions were the same as those of the teeth of the Myliobatini, 7. e. they
were employed in crushing shells, corals and other resistant substances, for
which both strength of form and great hardness were required.

VERTEBRATES. 57

Figures 17 and 17a represent a fragment of a worn tooth; basal surface and
section natural size.

Formation and locality: Keokuk limestone, Warsaw, Hflinois.

CHOMATODUS MULTIPLICATUS, N. and W. |
Pl. Ill, Figs. 18, 18a, 18.

TEETH very broad and low, four times as broad as high;
posterior aspect showing three nearly equal parallel bands, the
crown, the basal folds and root; the posterior face of the crown
is linear in outline, rounded at either end, its upper and lower —
borders nearly straight. The surface is smooth and polished,
the cutting edge acute and very finely crenulated by the fine
marginal striation of the anterior face;-basal band of imbricated
folds turned up and slightly rounded at either end, projecting
beyond the crown, enamel folds numerous (7-8), flattened, the
upper ones slightly widest; anterior face of crown strongly
deflected backward, but little narrower than the posterior,
concave vertically, gently arched laterally, its superior border
beveled off. to form the cutting edge, the beveled face being
very finely striated vertically; anterior basal ridge prominent,
narrow, showing about three folds; base smooth, narrow; root
as high and nearly as broad as the crown, quadrangular; its
posterior face retreating, its anterior and higher surface beveled
off from the middle down to an acute edge, everywhere rough-
ened and pierced by the foramina of the nutrient vessels; en-
tire height, 6 lines; breadth, 24 lines; height of crown, basal
folds, and root on posterior face, each 2 lines.

It is to be regretted that this very interesting and distinct species is repre-
sented in the collection by a single specimen only. Its very unusual breadth
separates it widely from the typical Petalodi, and yet, in other respects, it is
apparently like them. This, in itself, however, would indicate peculiarities of
the dentition, at least of the size, form and arrangement of the teeth in the
jaws of the fish possessing them, which, if we could define it, would serve as a
satisfactory basis for the description of the genus. .It is but fair to. suppose

58 PALAONTOLOGY OF ILLINOIS.

that between the fishes bearing the narrow, the broad, the sagittate, the oval,
the linear and the quadrate teeth, included in the Petalodont family, there were
at least as great differences as between Myliobates, Atobatis, Zygobatis and
Rhinoptera. ;

It will be noticed that in the present species we have the linear form of many’
of the polyrhizoid group, and a root which is only a mass of consolidated root-
lets, and which seems just ready to divide into distinct radicles, and yet its
section presents the sharpest cutting edge and the most angular outline of any

of the series. It thus forms a connecting link between its most dissimilar asso- _

ciates and illustrates the difficulty of separating them.
Figures 18, 18a and 180 represent the posterior face, a part of the anterior
aspect and a central profile section—all natural size.

Formation and locality: Burlington limestone, Burlington, Iowa.

CHOMATODUS LORIFORMIS, N. and W.

Pl. III, Figs. 19, 19.

TrEetH very broad, thin, strap-shaped, with parallel margins -

and'rounded at tle extremities; cutting edge straight through-
out the greater part of its length, curved downward at either
side, sub-acute, porous; posterior face of crown comprising two-
thirds the entire height of tooth, slightly curved vertically,
straight laterally, smooth and polished; posterior coronal im-
bricating folds about 4, low but distinct, the upper ones widest,
forming a band half the height of the crown face; anterior face
half the height of the posterior, to which it is inclined at an

angle of about 45°, straight or slightly concave vertically; —

coronal ridge a sharp angle, without distinct folds of enamel;
base occupying more than two-thirds of the anterior surface of
the tooth, slightly concave vertically; root nearly as broad as
the tooth, very short, extending but little below the posterior
basal folds, rounded in profile, roughened, not divided.

The only specimen of this species which exists in the collection is broken at
one end, and does not therefore give the entire breadth. The height is 44 lines.
The breadth of the fragment, 17 lines. The total breadth could not have been
much less than 2 inches.

bey

VERTEBRATES. 59

In its general aspect this tooth is much like the last described. Like that,

its disproportionate breadth renders it very unlike the teeth of any of the true
sharks of which we have any knowledge. The Rays and some Cestracionts
have equally broad teeth, but these all have flat or obtuse summits, fitted for
grinding or crushing; none of the incisive teeth of the carnivorous sharks hav-
ing anything like an equal relative breadth. It would be a matter of great
interest to ascertain, if it were possible, what was the position of these broad,
knife-like cutting teeth in the mouths of their possessors; whether they were
set transversely across the symphysis of the jaws, as in the Myliobatini, or on
the rami of either side, as in the Cestracionini.
Their perfect symmetry would rather indicate a medial position like the broad
teeth of the rays. Whether in this case they formed a single series, as in
Mitobatis, or were associated with narrower lateral teeth, as in Zygobatis and
Myliobates, we may perhaps never know, as the cartilaginous jaws on which
they were set have usually been wholly decomposed and the teeth scattered.
Figures 19 and 19a represent the face and profile, natural size.

Formation and locality: Keokuk limestone, Warsaw, Llinois.

Genus DIPLODUS, Ag.

‘Dretopus Latus, Newb.
Pl. IV, Figs. 1, le.
Diplodus latus, Newb., Pisce. Phil. Acad. Nat. Sci., 1856, p. 99.

TretTH large and robust; base thick and massive, elliptical
in outline, flattened below, with a large, obtuse tubercle pro-
jecting downward and forward at the anterior margin; posterior
end rounded; central cusp rudimentary or obsolete; lateral
denticles unequally divergent in the same plane, very robust,
2-3 times as high as broad at base, smooth and polished
throughout, compressed, with a lenticular section, and sharp,
crenulated, cutting edges, extremities sharp, but scarcely
pointed.

This is a large and robust species, the larger specimens being 9 lines high;
the extremities of the lateral cusps being separated by an equal interval. Un-

like D. gibbosus, Ag., and D. gracilis, Newb., the lateral denticles diverge in
the same plane, which is vertical to the antero-posterior axis of the base.

60 PALEONTOLOGY OF ILLINOIS.

Among the speciniens which I have been inclined to refer to this species,
considerable diversity of size and form may be noticed, and it is. by no means
certain that they should be regarded as specifically identical. Of these the
largest constitute the true type of the species, as first described. They are
characterized by the great strength of the lateral denticles, which are scarcely

~~-._ twice larger: than wide at base, and nearly of equal length, accurately set in

the same vertical plane. Another group, little smaller than these, are however
sensibly more slender. The lateral denticles, though as long, are narrower and
scarcely compressed at base. ‘The anterior tubercle is much more prominent,
and the posterior portion of the base has a vertical groove in the edge, at the
mesial line, and above this a broad, flattened, circular tubercle, which is rough-
ened on the upper surface, as though it was the place of a muscular attachment.
A similar character is shown in the magnified figure.of D. gibbosus, Ag. (Poiss.
Foss. Atlas, Vol. III, Tab. 226, fig. 4), but there the flattened tubercle is rep-
resented as though placed in apposition with and between the bases of the
lateral denticles. In all the specimens before me it is separated from the cusps
by a space equal to its own diameter, which is about 2 lines. In these two
groups, which I have hardly been willing to separate specifically, the central
cusp is either entirely obsolete or reduced to a small conical tubercle.

Another group of teeth, which are not rare in the Coal Measures of Ohio, is
represented in the collection by two specimens only. These I have formerly
designated by the name of D. compressus, though it is possible they should be
regarded as merely a variety of D. latus. They are, however, not more than
half the size of the teeth of that species. The base is relatively smaller, the
cornua more unequal, acute and compressed; one of the pair—the right or left,
according to the position of the tooth in the mouth—being much narrowed
toward the point and sigmoidally curved. In this group the margins of the
denticles are more distinctly crenulated. (See description of D. compressus.)

Figures 1 and Le, side views; 1a, 1b and 1c, anterior faces of different speci-
mens; 1d, posterior face—all natural size.

Formation and locality: Coal Measures, Posey county, Indiana, and Colum-
biana county, Ohio. :
DreLopus compressus, Newb.
Pl. IV, Fig. 2.
Diplodus compressus, Newb., loc. cit.

TEETH smaller and more slender than those of D. latus ; about
5-6 lines high, and having a space of 4 lines between the points

VERTEBRATES. 61

.

of the denticles; base small, 3 lines long, 24 broad, lateral den-
ticles narrow, compressed and crenulated, generally unequal in
length and unlike in form; the anterior? one being longest,
divergent at a greater angle, long-pointed, acute, doubly-curved,
4_5 times as long as wide; the posterior? one straight or falcate
and relatively broader; the median denticle, when visible,
short, acute, compressed and crenulated.

Figure 2, inner surface of large specimen, natural size.

Formation and locality: Coal Measures, Posey county, Indiana, and Linton,

Ohio.

DrpLopus pupiicatus, N. and W.
PL IV, Figs. 3, 3.

TrETH small, slender; base relatively small and thin; denticles
four, sub-equal, conical, divergent, curved, somewhat striated
longitudinally, with circular or sub-circular section, terminating
in acute points; entire altitude of tooth about 3 lines, length
of denticles 2 lines, spread of the most divergent 4 lines.

In the number of denticles this tooth differs so much from the species of
Diplodus heretofore described, that there may be some doubt whether it should
be included in the same genus with them. Jts structure, however, is on the
whole much like that of D.gibbosus, D. gracilis, etc., the only striking differ- _
ence being that this has four cornua, while they have two or three. The
number of denticles is, however, not constant in the genus—in the species I
have enumerated, the medial one being sometimes half the length of the two
lateral ones, sometimes reduced to a mere tubercle and sometimes even wholly
obsolete. Prof. Agassiz mentions having seen as many as five denticles attached
to one root, (Poiss. Foss., Vol. 3, p. 204.)

In the figure of D. minutus (Atlas, Vol. 3, Fig. 7, Tab. 226) four denticles
are seen lying nearly in contact, and perhaps may have been connected with
the same root. Should it prove, however, that there were sometimes four den-
ticles on the tooth of that species, ours would still be distinguished from it by
its much more slender and awl-like cones.

Figure 3 shows the posterior? aspect of an entire tooth, natural size; figure
3a, the opposite face of the same, enlarged to two diameters.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

|

62 PALEONTOLOGY OF ILLINOIS.

DieLopus incurvus, N. and W.

PI. IV, Fig. 4, 4a.

TreTH small; base large, thin, somewhat spoon-shaped,
smooth. From one extremity of this, spring three sub-equal,
recurved, divergent, conical denticles. These have a nearly
circular section, with a faint lateral angle formed by a fine
longitudinal carina; the anterior face of each being somewhat
flattened. —

But a single specimen of this singular tooth exists in the collection, and that
somewhat broken. Enough of it remains, however, to make out its form fully,
and to show its entire distinctness from any species before described. Its pecu-
liar character will be seen at a glance by reference to the figures which we give
of it. Length of base, 3 lines; breadth in widest part, 2 lines; length of
denticles, 13 lines.

Figure 4 represents the anterior aspect of the tooth; figure 4 a, the side
view, magnified to two diameters.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

Genus ORODUS, Ag.

Gren. CuAr.— Teeth laterally elongated, having their mid-
dle portion more elevated than their extremities, forming in
the central portion of the tooth an obtuse and transverse cone;
the longitudinal diameter, which much exceeds the transverse,
is also marked by a ridge sometimes medial, sometimes sub-
medial, from which spring oblique secondary ridges which
ramify upon the sides, and which, in the larger teeth, give rise
to another series of collateral ridges.”

The genus Orodus has not been before recognized in America.

OroDUS? MULTICARINATUS, N. and W.

Pl. IV, Fig. 13, 13 a.

TrxrtTu very large, thick and massive, central portion form-
ing a broad, obtuse cone, from which radiate numerous fine

VERTEBRATES. 63

but prominent carinz. From these spring a great number of
simple or branching secondary ridges, which spread over all
the surface of the crown. These ridges are sharp and well
defined, and are separated by obtuse furrows of about double
their width; both ridges and furrows highly polished and uni-
formly punctate.

It unfortunately happens that this remarkable species is represented in the
collection by a single specimen only, and that a fragment, a portion broken
from the centre of the tooth; the margins being gone, carrying with them all
data for determining its size orform. Itis evident, however, that it must have
been equal if not superior in size, to any other tooth in the collection. At
least 2 inches wide in its narrowest part. The microscopic structure and style
of ornamentation are very similar to those of the large and beautiful teeth
deseribed by Agassiz. (Poiss. Foss. Vol. 3, p. 97, Atlas, Vol. 3, Tab. 11, fig.
5-9), under the name of Orodus ramosus, and it is not improbable that we have
in this fragment the central cone of the tooth of a species ef Orodus, perhaps
generally similar in form to OU. ramosus, but considerably larger and more
highly ornamented.

Figures 13, 13 a, are top and side views, natural size.

Formation and locality: Kinderhook group, ‘“Goniatite bed,’ Rockford,
Indiana. ;

Oropus pLicatus, N. and W.
Pl. IV, Fig. 5.

TreETH small, laterally elongated, slender, somewhat arched;
crown bearing a sub-medial prominent cone, with 4 or # lateral
ones. The central cone is rounded, sub-acute, its summit
marked by numerous fine radiating strive. On either side a
beaded crest runs down to and over the lateral cones; lateral
cones small, not crowded, from their summits one or two promi-
nent, acute, divergent costee, descend on either side to the base
of the crown, much stronger on one side than the other; base
of the median cone and the entire surface of the lateral por-
tions of the crown on one side, ornamented with numerous,

64 . PALAONTOLOGY OF ILLINOIS.

fine, but distinct, horizontal lines or folds. On the opposite
surface these are nearly obsolete.

This slender and highly ornamented species, though presenting a general
similarity to several of the preceding group, may be at once distinguished from

them by the numerous fine horizontal lines which cover one face of the crown.
Figure 5, 5 a, side view of a broken specimen, twice the natural size.

Formation and locality: St. Louis limestone, St. Louis, Missouri.

ORropUS ELEGANTULUS, N. and W.
Pl. LV, Bigs. 6, Gia.

TrrtTH small, laterally elongated, narrow and slender; crown
conical, bearing a prominent central cone, from which the out-
line slopes away to either extremity. The median cone is
faintly marked with a few delicate radiating raised lines. On
either side of this are six or eight small tubercular secondary
cones, from each of which spring about three raised lines,
which diverge and cover most of the anterior face of the crown;
this line of prominent points is not medial, but nearer the pos-
terior than anterior border. ‘The posterior face of the crown is
somewhat roughened with short, tortuous, raised lines and
tubercles. The crown is covered with a coating of dense trans-
lucent enamel, highly polished, and without pores. The root
seems to have been cartilaginous, and has usually disappeared.

This elegant little species bears considerable resemblance to the last, but is
somewhat larger and much smoother; the raised lines which ornament the sur-
face of the crown being comparatively few and faint, and having a different
arrangement. When seen on profile it exhibits some resemblance to O. einctus,
Ag., but on close examination it will be seen that the ornamentation is quite
different. In O. cinctus the median cone, as well as all the lateral prominences,
are unbroken rings which arch over from the front to the rear, while in our
species the central elevation is distinctly, sometimes acutely, conical, marked
with- radiating lines. The secondary tubercles are round, smooth, and distinct,
and from these, three or four sharp, raised lines, diverge to cover one side only

of the crown, constituting a much more complex and beautiful style of orna-
mentation.

VERTEBRATES. 65

Figure 6, 6 a, represent the top and side view of a medium specimen, natural
size.
Formation and locality: Burlington limestone, Burlington, Iowa.

Oropus orNATUS, N. and W.
Pl. IV, Figs. 7, 7 @, 8, 8a. i

Tren small, laterally elongated, with a prominent central
cone, and a more or less conical outline; crown highly orna-
mented with numerous prominent carine. Of these, ten or
more radiate from the summit of the central cone, covering its
sides with their tortuous branches. From the central cone a
sharp and prominent crest runs down to either extremity
along the median line. In some specimens this crest is broken
up into numerous small, lateral cones, which are ornamented
like the principal one, with radiating carine. In other speci-
* mens these secondary cones are scarcely developed, but the
crest is serrated, when seen in profile, by the outlines of the
numerous ridges which cross it. The root is usually slightly
narrower than the crown, and of equal height, coarse, and
porous. A transverse profile shows it to be in most specimens
oblique to the crown.

These are highly ornamented teeth, the crown being elaborately sculptured
in every part. They vary much in size, and somewhat in form, the larger ones
being laterally long and narrow, from 6 to 7 lines in length, while the smaller
ones are half as long, but thicker in the central part; when seen from above
often presenting a sub-triangular outline. By their general aspect they remind
one of Orodus cinctus, Ag., (Op. Cit. p. 96, Tab. 11, fig. 1-4,) but they are
much smaller, and the ornamentation is more elaborate and of a different pat-
tern.

Figures 7 and 7 a, represent a larger and smaller tooth, each viewed from
above, magnified to two diameters. Figures 8 and 8 a, crown and side view
of another small specimen, natural size.

Formation and locality: Keokuk limestone, Warsaw and Nauvoo, Illinois.

—9

66 PALAONTOLOGY OF ILLINOIS.

Oropus TUBERCULATUS, N. and W.
Pl. LV, Wigs. 9599.

TrretH small, short, high, conical in outline; median cone
relatively large, pointed, sometimes acute; lateral cones rudi-
mentary, nearly obsolete, two or three on either side of the
principal cone, rapidly diminishing, together forming pointed
lateral appendages to the central prominence; central cone
bearing several prominent ridges, strongest at the base, fading
out at the summit; similar ridges upon the lateral extremities
in pairs form the rudimentary secondary cones. On the inside
the ridges are less distinct, and are in part represented by
enameled tubercles; whole surface of crown polished, and with-
out pores.

The species before us bears a strong resemblance to the preceding one, and
indeed to all the smaller species which we have described, It is, however,
apparently distinct from all, and may be recognized by its relatively short and
high figure, the preponderance of the central over the secondary cones, by its

few, strong, ornamental ridges, frequently represented by mere tubercles, ete.
Figure 9, crown face seen from above; 9 a, side view, both twice natural size

Formation and locality: Burlington limestone, Quincy, Illinois.

ORODUS MAMMILLARIS, N. and W.
P1.IV, Fig. 10, 10a.

TrrTH small, laterally elongate, slender; crown arched or
sub-conical, having a prominent median cone, with a series of
2—5 lateral cones on either side; median cone round, as broad
as high, the lateral ones more or less appressed and flattened
vertically. All these cones are ornamented with numerous,
prominent, often beaded ridges, which are strongest at the base
and fade out toward the summit on the median and some of
the lateral cones. On those near the extremities they meet
above. These ridges are strong and rounded; there are about
four on either side of the lateral cones and twice as many

VERTEBRATES. : 67

upon the central one. The root has, on the inner side, an
altitude one-third less than that of the crown, there presenting

-a vertical, coarse and porous surface. From the lower border
of this the inferior surface slopes up to the corner on the oppo-
site side.

In size and general character the species may be compared with the two pre-
ceding, but in the details of its structure is still quite different from either.
From O. ornatus it may be at once distinguished by its very distinct lateral
cones, which are separated by deep sulci, and, like the middle one, are con-
stricted at the base; the ridges coarser and more obtuse, and more restricted to
the base of the crown.

From 0. elegantulus it may be easily separated by noticing its more conspicu-
ous lateral cones—its stronger ornamentation occupying the base of the crown
on either side, while in O. elegantulus it is mainly restricted to the summit and
one face.

In the specimens contained in the collection we have one on which are more
than a dozen teeth, that apparently belonged to a single individual. It is
therefore of special interest as affording a little of the information so rarely
obtained in reference to the variety of form displayed in the dental series of a
single pleozoic fish. Unfortunately this specimen is much weathered, and all
finer markings are oblitered. We can see, however, that there was considera-
ble diversity of size and some difference of form among them, there being longer
and shorter ones, those nearly straight and those strongly arched, those with
conspicuous roots and those with little or none, and finally those relatively thick
and strong and others very slender. The surface marking is, however, as far
as it has been preserved, essentially the same in all. Many of these teeth were
apparently much worn during the life of their possessor, and it is evident from
their condition, as well as from other facts which have come under our obser-
vation, that the subsistence of Orodus was made up, for the most part, of mol-
lusks or other resistant substances, which it was necessary to crush, and in
triturating which their teeth were much worn and impaired.

Figures 10 and 10a, side and top views, natural size.

Formation and locality: Keokuk limestone, Nauvoo and Warsaw, Illinois.

Oropus minuscuLUS, N. and W.
Pl. IV, Fig. 11.

TRETH very small, arranged in a series of five or more, dimin-
shing in size from front to rear, their summits forming an arch

68 PALAONTOLOGY OF ILLINOIS.

in the same direction; each individual tooth laterally elongated,
slender, somewhat arched in outline, strongly so in profile;
crown smooth and highly polished throughout, forming an
angular ridge, crowned with numerous prominent, bead-like
points. Of these the largest is nearer one end than the other;
from this point the secondary cones diminish in size to either
extremity; lateral length of longest tooth 3 lines; of shortest,
1 line; breadth about half a line.

The teeth which form the basis of the foregoing description retain the rela-
tive position which they occupy on the jaw. Like most of the teeth of the
genus, they are laterally unsymmetrical, the median cones not being placed on
the central point of their longest diameter. Though very minute they are neat

x and exact in their forms and markings, and undoubtedly are the only traces
yet discovered of an entirely distinct species of fish which inhabited the Car-
boniferous seas.

Figure 11 represents the series of teeth described above, magnified to two
diameters.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

> Oropus minutus, N. and W.
Pl. IV, Fig. 12.

TEETH very small, forming a series of four or more, increas-
ing in size from behind forward; each individual tooth laterally
elongated, linear in outline, rounded at one extremity, appa-
rently obliquely truncated at the other; crown forming a semi-
cylindrical ridge, with a median cone nearest the truncated
end. This is worn down in the specimens before us, and its
form and relative elevation cannot be determined. The lateral
surfaces of the crown exhibit no secondary cones, but the me-
dian line is marked by a fine, sharp crest, giving off, nearly at
right angles, simple or forked thread-like carinz, which run
down to the base.

This species resembles O. ornatus and O. elegantulus more than any others
described, but the crown of O. ornatus is less straight and symmetrical in out-

VERTEBRATES. 69

line, and the raised lines which ornament it are very tortuous and irregular—
the larger ones giving off numerous short lateral branches, which give them a
pectinated appearance, nothing like which is observable in the species before
us. In O. elegantulus a line of bead-like tubercles crown the medial crest, the
lines of ornamentation running down upon one side only, while in'O. minutus
both faces of the crown are ornamented. In size the teeth of this species are
intermediate between O. ornatus aud O. minusculus.

Figure 12 represents two teeth of a series ef four, seen from above, twice the
natural size.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

Genus CARCHAROPSIS, Ag.

CarcHaropsis WortHENr, Newb.
Pl. IV, Figs. 14, 14a.

Bask semi-elliptical in outline, irregularly, coarsely but not:
deeply scolloped, thick, flattened below, sloped off to the edges
above, slightly broader than the entire height of the tooth;
median cone conical, its height about equal to its width, meas-
ured across the upper surface of the expanded base; anterior
face flattened, posterior regularly rounded, entirely smooth
throughout; margins strongly and evenly crenulated from the
apex to the base; lateral denticles two on either side, the exte-
rior pair largest, about one-quarter the length of the median
cone, situated a little back from the anterior margin, on the
extreme points of the base, conical, acute and smooth, and
slightly divergent from the axial line of the principal cone;
second pair slightly in advance of and within the largest secon-
daries, scarcely more than tubercles. Breadth of base, 1 inch,
2 lines; height, apex slightly worn, 1 inch.

The beautiful tooth from which this description was taken is the first of the
genus, so far as we know, that has ever been found on the American continent.

Partially covered by the stone it had the appearance of Cladodus, but present-
ing some peculiarities, was carefully developed when the elegant crenulation of

70 PALHONTOLOGY OF ILLINOIS.

its margin showed itself, and its affinity to the teeth upon which McCoy founded
the genus Pristicladodus, at once suggested itself.

This species fully confirms McOoy’s view of the classification of the teeth to
which he gave this name, (Brit. Palxoz. Foss., p. 642.) With the one before
us there are now three species known, which, with striking departures from all
other types, have certain common characters, uniting them in a most natural
generic group.

The name selected by McCoy for the genus also seems well chosen, for while
the broad, semi-circular, thickened bases of these teeth and their lateral denti-
cles, of which the exterior pair are largest, show their intimate relationship to
those of Cladodus, the broad, semi-conical, crenulated median cone, which
occupies nearly the entire breadth of the base, and so entirely overshadows the
lateral denticles, gives the group a facies quite distinct from that of Cladodus,
and show it to be a kind of connecting link between the Hybodonts and the
Carcharodonts. McCoy’s name was, however, anticipated by perhaps the
equally appropriate one of Carcharopsis of Agassiz.

The crenulation of the edge of the median cone in C. Wortheni is remarka-
bly regular and distinct, and is continuous from the summit down to the lateral
denticles. The apex of the principal cone is somewhat worn, but was appa-
rently quite sharp. The anterior surface is not accessible, but is evidently
flattened, as in P. dentatus, McCoy, and somewhat excavated.

Figures 14 and 14a, posterior aspect and side-view—natural size.

Formation and loculity: Sub-carboniferous limestone, Huntsville, Alabama.

Genus PETRODUS, McCoy.

PETRODUS OCCIDENTALIS, N. and W. -
.

PI. IV, Figs. 15, 15a, 158, 16, 16a.

Bass sub-circular or elliptical in outline, flat or slightly
concave below, thin, terminating in an abruptly sharpened,
finely crenulated edge, broader than the crown; crown broadly
conical, acute or rounded at the summit, with a sub-circular or
elliptical section, constricted at the base, marked with a varia-
ble number of strong, divergent ridges, many of which are
forked below; ridges generally smooth, but sometimes more or
less rugose.

VERTEBRATES. he

This species is so much like P. patelliformis, McCoy, (Paleozoic Fossils, p.
637, pl.3, G. figs 6,7, 8,) that I have hesitated to consider it distinct. In
P. patelliformis, however, the radiating ridges of the crown are represented by
Prof. McCoy as being always strongly sulcated transversely, almost pectinated
in fact, while in the great number of specimens in tle collection none exhibit
this character; a slight rugosity, rarely visible, is the only approach to it.

Prof. Agassiz has suggested that these bodies were not teeth, but the dermal
tubercles of some of the ancient sharks. This supposition is rendered probable
by their resemblance to the cretaceous tubercles of living plagiostomous fishes,
particularly the Rays, and by some peculiarities of their structure as compared
with other teeth. It will be seen that the base is exceedingly thin and very
flat, much more so than in the teeth of any of the cestracionts, and too much so,
we might suspect, for the requisite solidity and stability of teeth of which the
function was the crushing of resistant substances. The base is, also, not only
thin and weak, but laminated on every side in a thin, sharp, finely crenulated
edge. This shows that if teeth, they must have been isolated and nowhere in
contact with each other. In these respects they offer a strong contrast to
Orodus, Acrodus, Ptychodus, etc., to which they have otherwise considerable
resemblance. In all these genera the bases of the teeth are much thicker, and
of forms that prove them to have been in contact with each other, and even
matched together with a kind of pavement.

The extreme probability of the suggestion of Prof. Agassiz will be at once
seen by reference to the figures which he gives of a fossil ray from the Lias of
Lyme Regis, (Poss. Foss. Atlas, Vol. 3, pl. 42, 43,) the dermal tubercles of
this fish (Squaloraja polyspondyla) exhibiting a marked resemblance to those
bodies called Petrodus by Prof. McCoy, and considered by him to be teeth.

There is great variation in form and size in the large number of these fossils
included in the collection, some being ten times as large as others, some circu-
lar and some long-elliptical in oytline, some being acute at summit and marked
with sharp divergent ridges, others nearly smooth, as though much worn.
With the exception, however, of that which formed the basis of the succeeding
specific description, they should probably be all regarded as the exuve of the
same species of fish. A large, sub-triangular, nearly smooth specimen, from the
Coal Measures of LaSalle, exhibits some peculiarities which may have a specific
value. Without further evidence, however, we should hardly be justified in
regarding it as distinct from those we have designated by the name of P. occi-
dentalis.

Figures 15, 15a and 158, top and side views of two teeth; 16, 16a, another
tooth, perhaps specifically distinct.

Formation and locality: Coal Measures, Belleville, Illinois.

~I
bo

PALAONTOLOGY OF ILLINOIS.

‘PEtropus acutus, N. and W.

PL.IV, Pig. 17.

THERE is in the collection a single specimen of Petrodus that
is derived from a different locality from the others, and which
is so unlike them as to justify its separation from them. It is
small in size, elliptical in outline, and the carinze of the surface
do not radiate from a central point, but the line of the longest
diameter is marked by a prominent, acute crest, from which
4—5 pairs of acute, simple ridges are given off pinnately run-
ning down to the base. All the carine are, as compared with
those of P. occidentalis, much sharper.

Figure 17, a small specimen seen from above, twice natural size.

Formation and locality: Coal Measures, Pike county, Illinois.

Genus CTENOPTYCHIUS, Ag.

Gren. Cuar.—Teeth small, highly polished, strongly com-
pressed, rounded or obtusely pointed, edge divided into several
strong denticulations; base of crown with a few imbricating
folds of ganoine; bony root oblong, flattened in the same
direction as the crown.

It is very apparent that the species which have been referred to Ctenopty-
chias require separation; as, for example, Cts apicalis, Ag., can hardly belong
to the same genus with Ct. serratus of Owen; but we have not now the mate-
rial for a discussion of the question of which should retain the name of Cten-
optychius. ;

CTENOPTYCHIUS SEMICIRCULARIS, N. and W.

Pl. IV, Figs. 18, 18 a, 18-b.
TrrtH of median size; crown very thin, much compressed,

and laterally curved, when viewed from above in outline form-_
ing a full semi-circle; anterior and posterior surfaces smooth

VERTEBRATES. Ta

and highly polished, without strize or pores; superior margin
forming a sharp, cutting edge, divided into numerous lobes, of
which the middle one is largest, the others diminishing succes-
sively, to the lateral angles. These lobes are usually unequal
in number on either side of the largest one, four on one side
and five on the other. They are generally rounded in outline
but sometimes acute. The anterior and posterior surfaces of
the crown are of nearly equal height, the anterior sometimes
showing a basal ridge as in Petalodus. The root is thicker than
the crown and higher, nearly or quite as broad and of a some-
what similar form, except that its border is not scolloped.
Both faces of the root are more or less roughened. On the
posterior surface the root at its junction with the crown forms
a broad shoulder, which is depressed at the centre with a deep,
conical cavity. This gives to the profile section much the
character of that of some species Petalodus, as will be seen by
a reference to the figures.

When viewed from the front or rear the outline of these seems strikingly
like that of the teeth of Ct. apicalis, Ag., as given by Agassiz, Poiss. Foss.
Atlas, Vol. 3, tab. 19, fig. 1, la. Yet it would seem that in fact these
forms are so widely different that it is even doubtful if they should be included
in the same genus. Ct. apicalis is described as “‘transversely ovate,’ and
judging from the figures and description of Agassiz and McCoy must be some-
what similar in general aspect to Chomatodus dentatus, McCoy, while the teeth
before us are thinner and more curved laterally than in any species of Petalodus.
Ct. serratus, Owen, (Brit. Palzoz. Foss. p. 626, Pl. 3-1, fig. 21, 22, 23), is, how-
ever, more like our species in general form, but is less curved and has nearly
thirty denticles on the cutting edge, while in C?. semicircularis there are but
seven or eight.

The affinity of this species of Ctenoptychius with Petalodus will be seen by
reference to the figures, to be very marked. McCoy has noticed this relation-
ship in his description of C¢. serratus, which would be considered a Petalodus
were it not for the coarse crenulations of the cutting edge. M. Agassiz com-
pares Ct. apicalis to a small, compressed Orodus, which it is certainly very like,
but it is evident that the present species is more closely allied to Petalodus than
- Orodus, and is in fact the most exaggerated form of lamillar and arched type
of teeth first and best known by the former name.

—10

74 PALEONTOLOGY OF ILLINOIS.

Figure 18, anterior crown face; 18 a, same seen from above; 18 b, from the
side.
Formation and locality: Coal Measures, Posey county, Indiana.

Genus HELODUS, Ag.

Gen. Cuar.—“Transversely elongate, crown convex, eleva-
ted along the middle into an obtuse, conical ridge, sometimes
divided into a line of several compressed cones diminishing
from the centre; surface porous, as in Psammodus; margin of
the crown raised in the middle on both the inner and outer
sides, and it and the root vertically plicated.”

v
: It is evident that among the species at present included in the genus Helodus
there is much incongruity, and the whole group requires a thorough revision
and more or less sub-division, before anything like a distinct idea can be con-
veyed of a generic character represented by the name Helodus. Still the time
has, perhaps, not yet arrived, when the required revision can be satisfactorily
performed. The number of species which have been described is now about a
dozen, and there are in the collection before us at least an equal number, which
would be grouped with them in the genus Helodus as at present defined. Of
these as we shall be able to show that some are probably nothing more than
the median teeth of the jaws which bore on their rami the convoluted plates
known as Cochliodus, while others having a general similarity of form, with
these apparently constituted portions of a dental series not very unlike through-
out. Both these groups have a laterally elongated form, with a conical profile,
and a prominent central boss or cone, with or without secondary prominences
on either side of this. The median teeth of Cochliodus, a group which must
include several described species of Helodus, (e. g. H. levissimus, H. didymus,
H. turgidus, etc.), haye been found in regularly diminishing series like some of
those now figured. Another group of Helodi, of which H. planus, Ag., may
be taken as a type, in their broad and flattened forms resemble Psammodus, to
which they approach more nearly than to the turgid and conical species with
which they are now associated. These formed a payvement-like dentition which
was, perhaps, similar in character throughout the mouth, or they might have
formed a part of the varied dental series of Cochliodus. It is probable, how-
ever, that of these a group may be gathered which would possess a fairly
defined generic character. It is desirable, however, for the satisfactory classi-
fication of this heterogeneous material, that specimens of at least a considera-

VERTEBRATES. 75

ble number of the species already described should be carefully compared with
those now before us, and it is perhaps wiser to wait the time when this shall be
possible, rather than to attempt now to make the sub-divisions to which we
have referred. It seems to us not probable that He/odus should be regarded, as
suggested by Prof. McCoy, as a sub-genus of Psammodus, or at least that any
other than the last group referred to should be so considered. The flat, quad-
rangular teeth of Psammodus form a very natural generic group, and the
porosity of their surfaces is no more like that of Helodus than Cochliodus.

HeEtopus conicutus, N. and W.
Pl. IV, Figs. 19, 19 a.

TrETH small, laterally short, crown composed of a relatively
high, rounded central cone, with short lateral appendages;
these latter are rounded or obliquely truncated, and project
not quite half the diameter of the cone from its base. A sulcus
surrounds the crown constricting it, at its junction with the
root; root not yery short, nearly as broad as the crown,
oblique, its vertical face deeply impressed with vermicular cavi-
ties; the crown surface is smooth and polished, and uniformly
porous throughout. e

This species is closely allied to H. didymus, Ag., but seems to be distinguish-
ed from it by its relatively larger cone, the sulcus around the crown, and the
pitted root.

Figures 19, 19 a, give a front and side view, natural size.

Formation and locality: Burlington limestone, Burlington, Iowa, and Keokuk
limestone, Nauyoo, Illinois.

HELopUS CARBONARIUS, N. and W.
Pl. IV, Figs. 20, 20a.

TEETH small, transversely elongate, crown linear in outline,
gently arched laterally, strongly so transversely, smooth and
polished throughout, marked with numerous relatively coarse
pores, which frequently coalesce, forming a fine but irregular

i ee

76 PALEONTOLOGY OF ILLINOIS.

reticulation; root as broad and nearly as high as the crown,
very oblique, vertical face, marked with pits and vermicular
grooves, inferior surface roughened.

This very distinct species is represented in the collection by a single frag-
ment only. That is, however, sufficient to show its general form and its struc-
ture. In form it is not unlike some species we have described, from the lower
rocks, but its microscopic structure is unlike that of any other species with
which we are familiar. The enamel tubes are much wider than the spaces
which divide them, and as they frequently coalesce, they form on the tritura-
ting surface a fine reticulation not unlike that of the surface of Strophodus.

Figures 20, 20 a, represent side view and section, natural size.

Formation and locality: Coal Measures, La Salle, Illinois.

HELODUS DENSHUMANI, N. and W.
Pl. IV, Figs. 21, 21a, 218.

Toor small but strong, crown sub-quadrate in outline, the
angles being rounded, sides slightly arched, margins also
rounded, thicker on one side than the other, flattened above,
the central portion depressed on the anterior side, leaving an
elongated tubercle or prominence on either end, triturating sur-
face highly polished, marked with numerous, large, closely set
pores; root quadrangular, as wide as the crown and much
higher, coarse and long, sides and posterior face nearly straight;
the anterior face showing two concavities separated by a
prominent line, the upper much larger; largest diameter of
crown 4 lines; shortest 2% lines; entire height 5 lines.

This peculiar tooth, which, taken by itself, naturally enough falls into the
genus Helodus, is probably one of the minor forms of some varied dental series.
Its robust figure and coarsely porous structure seem to indicate that it was
worn by a fish possessing considerable muscular power, perhaps of large size,
furnished with a strong crushing apparatus, composed mainly of large and
massive teeth, among which this was introduced to fill an interstice, or as one
of a medial series. Its form, not unlike that of a worn human bi-cuspid has
suggested the name given it.

VERTEBRATES. V7

The figures given represent the crown surface, posterior face and profile,
natural size.

Formation and locality: Keokuk limestone, Warsaw, [llinois.

HELopusS BiForMIs, N. and W.

Pl. IV, Fig. 22, 22a.

TEETH small, in series of three or more, the central one being
largest and quite different in form from one of those associated
with it. Itis oblong in outline, arched in both directions, its
highest point being nearly central, its anterior margin some-
what waved with a prominent central gibbosity; the anterior
tooth is nearly as large as the central, but narrower, somewhat
curved and adapted to the outline of the central one; its sur-
face is raised into three prominences, separated by shallow
grooves, of which the central one is somewhat the largest.
The small posterior? tooth is about half the size of the cen-
tral one with a similar median gibbosity. The enameled
surface of all these teeth is uniformly punctate, the termini of
the enamel tubes being raised above the general surface; the
roots are short, narrower than the crown, oblique.

This very distinct and peculiar species exhibits characters considerably dif-
ferent from those of any other with which it is associated in the collection.
It is from a geological horizon which has furnished but one other species of
Helodus, and it may hereafter prove to be a type of a distinct genus. There
are contained in the fragments of stone in which it is imbedded numerous small
kidney-shaped teeth, having precisely the same structure, and doubtless once
belonging to the same fish. We may conjecture that those which we have now
described formed a medial series, flanked on either side by broader and flatter
teeth, as in the living Cestracionini.

Figure 22, the series of three teeth described above, natural size; 22a, a
large, detached tooth.

Formation and locality: Kinderhook group, Burlington, Iowa.

78 PALZONTOLOGY OF ILLINOIS.

- Heropus etyrra, N. and W.
Pl. IV, Fig. 23.

TEETH small, in series of three or more of unequal size. Of
these the anterior one is most elongated laterally and highest,
the middle one shorter, broader and flatter, the posterior one
smaller in both senses and flatter than either. They are all
oblong in outline, with rounded ends, gently arched both ways,
smooth and polished throughout, the surface of each uniformly
and relatively coarsely porous. ‘The resemblance which they
bear to the elytra of some beetles has suggested the specific
name selected.

Figure 23 represents the series described as seen from above, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

HE Lopus compressus, N. anf. W.
Pl. V, Fig. 1.

TreTH small, much compressed, conical in profile, narrow,
linear in outline when seen from above; crown thin, compressed,
terminating above in a sub-acute edge, having an obliquely
conical outline when seen in profile; median cone sub-central,
the apex being laterally rounded and somewhat inclined toward
one of the extremities; ends rounded, narrowed below to the
root; the edge of the crown, between the summit of the cone
and the extremity to which it is inclined, faintly notched or
waved; anterior and posterior faces of the crown flattened and
inclined toward the root; surface highly polished, without pores;
root thin, relatively narrow, slightly roughened; breadth 3%
lines, height 2 lines.

This is a very small species, differing in some important characters from
any heretofore described. With the general form of Helodus it is very much
more flattened, having almost a cutting edge. It is apparently composed of
dense and homogeneous enamel, without pores. In its compressed crown, its

VERTEBRATES. ; 79

obliquely conical profile it ‘approaches more nearly to the teeth of some living

sharks, such as Galeus, G'aleocerdo, etc., than any of the forms with which it is

associated. iy
Figure | is a front view, twice the natural size.

Formation and locality: Burlington limestone, Augusta, Iowa.

Hexopus pouitus, N. and W.
Pl. V, Fig. 2. ‘

TrxETH small, laterally elongated, outline linear, expanded at
the centre, somewhat curved, profile strongly arched or rudely
conical; crown composed of a relatively large central gibbosity,
from which slender appendages are given off, forming the lat-
eral extremities; both the central and lateral portions strongly
arched transversely, so as to constrict the crown below; entire
crown surface covered with dense, homogeneous, black, polished
and shining enamel, in which no pores are distinctly visible;
root small, oblique, having generally disappeared or remaining
only as an ochery mass; length, 7 lines; height of crown, 2 lines.

This peculiar tooth is not likely to be confounded with any which we have
described. It will be at once recognized by its singular form and by its highly
polished and poreless surface. Specimens of H. gibberulus, Ag., now before us,
from the Armagh limestone, approach closely to it in form, but in that species
is very distinctly, even coarsely porous.

Figure 2 represents the posterior aspect, natural size.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

Hetopus cisposus, N. and W.
Pl. V, Figs. 3, 3a.

TEETH of medium size; outline as seen from above, linear,
with a central protuberance on one side; extremities rounded,
profile conical, summit of cone nearest one end, crown strongly
arched transversely, and slightly constricted atits base, surface
uniformly and finely porous. On one side a conspicuous conical

a ee ee re ae
’ yy oe ‘

_

80 PALEONTOLOGY OF ILLINOIS.

gibbosity protrudes opposite the highest point; base large and
thick, as high and wide as the crown, coarse and porous, one
face slightly arched outward and striated vertically, the oppo-
site one concave, under surface oblique, smooth. Length, 1
inch; height, 7 lines.

\ In the character of the root, and the porosity of the crown, this tooth shows
some resemblance to H. denticulatus, and it is possible they are parts of the
same dental series; there are, however, very marked differences in the form of
the crown, and, as we have no evidence of identity, we are compelled, for the
present, to regard them as distinct.

* Figures 3, 3a, represent side view and section, natural size.

Formation and locality: Keokuk limestone, Hamilton and Warsaw, Illinois.

Heiopus pLAcentA, N. and W.

Pl. V, Fig. 4, 4a.

Treta of medium or small size, sub-elliptical in outline, flat-
tened, thin; crown slightly and irregularly arched in both
directions, finely porous throughout, thicker on the posterior
than the anterior edge, margin somewhat rounded, root oblique,
presenting a vertical face as high as the crown on one side of
the tooth, its inferior surface sloping up to the opposite border;
the vertical side of the base marked with strong, irregular,
vertical ridges.

The tooth is somewhat like Helodus planus, Ag, but is less angular in out-
line, more finely punctate, and wants its characteristic crenulated margin.

Figures 4, 4 a, are intended to represent the appearance of one of these
teeth, when viewed from above and from the posterior side.

Formation and locality: Kinderhook group, Burlington, lowa.

HeLopus timax, N. and W.
Pl. V, Fig. 5, 5 a, 5 3.

-Trrtu of medium size, laterally elongated, somewhat curved,
extremities rounded; entire crown smooth and highly polished,

VERTEBRATES. 81

arched laterally, transversely rising into an obtuse and round-
ed mesial ridge; pores relatively coarse, those of the broader
slope elongated, more or less curved, but never inosculating,
the root small, half the height of crown, oblique on one side,
nearly straight on the other. Length, 11 lines; breadth, 4
lines; height, 4 lines.

The teeth of this species may be recognized by their smooth and rounded
outlines without points or angles, by the polished surface, coarse and elongated
pores. In their general aspect they bear a striking resemblance to the teeth of
Strophodus tanwis, Ag., (Poss. Foss. Atlas, Vol. 3, tab. 18, fig 16-25), from the
Oolite of Stonesfield, though differing from these in microscopic structure. Of
described species of Helodus, they are most like some forms of H. leevissimus,
but want any approach to a central cone. The resemblance which they exhibit
to the garden slug has suggested their specific name.

Figures 5, 5a, 5b, represent one of these teeth seen from above, the side,
and the end, of the size of nature.

Formation and locality: Burlington limestone, Burlington, Iowa.

HELODUS DENTICULATUS, N. and W. ©
Pl. V, Fig. 6, 6a, 6d.

TxrETH of medium size, conical in profile, outline irregular,
middle portion broadest, ends rounded sharp, sides scolloped,
crown sloping evenly toward either extremity, from the most
prominent point, which is not central, strongly arched laterally,
bearing along the basal margin of one side numerous, conical,
tooth-like prominences, base showing faint traces of enameled
folds; triturating surface uniformly, finely, punctate; root as
high and broad as the crown, relatively thick, rough and
porous, oblique below. Length, 9 lines; height, 5 lines.

The tooth will be readily recognized by the tooth-like appendages set along
the sides of the crown.
Figures 6, 6 a, 66, side view, top and profile, natural size.

Formation and locality: Keokuk limestone, Hancock county, Illinois.

—l1

82 PALAONTOLOGY OF ILLINOIS.

HeLopus crenuuatis, N. and W.
PLY, Hignit, it a

TEETH of medium or large size, outline showing a prominent
median angle, the lateral surfaces very unequal in length,
somewhat rounded. When seen in profile the outline is also
conical, with a prominent angle, but no cone. The crown is
arched over transversely, on one side constricted, or the surface
turned under; both margins are very neatly crenulated by
short, deep, sub-equal sulci; the enameled surface finely and
evenly punctate throughout; root very oblique, generally want-
ing in the fossil state.

; This is a laterally short and flattened species, readily distinguishable from
any other described by its angled outline, when seen from above, and by the
distinct crenulation of the crown margins. The specimens we have described
were found mingled with fragments of the teeth of Cochliodus, haying the same
deep black color, and the same microscopic structure. It seems probable there-
fore, that both once formed parts of the dentition of the same fish.

Figure 7, represents the crown as seen from above, natural size; figure 7a,
under side of same specimen.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

“ Hetopus unpuLatus, N. and W.
Pl. V, Figs. 8, 8a, 80.

TEETH medium size, laterally elongated, somewhat bow-
shaped in outline, with a prominence before, a sinus behind ;
crown conical in outline, the central cone prominent, sub-acute,
from this the surface falls off toward either end; upon the
lateral portions the enamel is raised into short, broken undula-
tions, and tubercles; the porosity is coarse and somewhat irregu-
lar, the root is oblique, coarse and bony, showing a nearly ver-
tical face posteriorly, two-thirds as high as the crown; from
the lower margin of this the under surface slopes upward to
the crown on the opposite side. :

VERTEBRATES. 83

The undulation of the enameled surface constitutes the most distinctive
character of the species. It resembles that of a species of Pocilodus, in the
collection, and they were perhaps once associated together.

Figures 8, 8a, 8b, represent the view from above and behind, and a profile
section, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

HELopUS ANGULATUS, N. and W.

Pl. V, Figs. 9, 9a, 9, and 10, 19a.

TretH elongated, linear in outline, obliquely truncated at
the ends, often sigmoidly curved, arched laterally with a mesial
ridge, but with no distinct tubercle or cone. In some speci-
mens the triturating surface on either side of the ridge is trans-
versely concave, in others one convex, usually smooth and
polished, marked with large, elongated pores; the root is usu-
ally oblique, short and wedge-shaped; length, half an inch to
an inch; breadth, 4 lines.

These teeth are closely allied to H. imax, but the numerous specimens in
the collection seem to have a character in common, which that species wants,
viz: their angular section. The ends are also generally truncated, not round-
ed, and they are more twisted. As has been before remarked, this group of
teeth are strikingly like some species of Strophodus, and itis a suggestive fact
that their microscopic structure diverges from that of their congeners in the
Carboniferous limestone in the same direction. The pores of the enameled
surface forming elongated and irregular lacuaze, approaching in character the
angular reticulation of Strophodus.

Figures 9, 9a, 9 6, represent the top, side views and sections of two of the

larger teeth ; figures 10-15, smaller specimens, apparently not specifically dif-
ferent. -

Formation and locality: Burlington limestone, Quincy, Llinois.

Hetopus sutcatus, N. and W.

Pl. V, Fig. 16, 16a.

Trretu of medium or small size, thin; crown linear in outline,
broadest in the middle, the extremities truncated or somewhat

;

'
fh
at

84 PALZONTOLOGY OF ILLINOIS.

rounded; sub-medial obtuse ridge traversing the crown longitu-
dinally, raised in the centre into a more or less prominent gib-
bosity. The upper side of this ridge is arched over transversely ;
on the lower side it descends into a broad and deep sulcus,
which runs the whole length of the crown, and occupies full
half the breadth. The surface of the ridge, and in worn speci-
mens, a part of the sulcus, is finely and uniformly punctate;
the lower margin of the crown is usually more or less corruga-
ted or striated vertically, sometimes showing faint traces of
marginal plications; root small, oblique, and has ior dis-
appeared.

This species bears considerable resemblance to some of the specimens figured
by Agassiz, under the name of Helodus turgidus, but is narrower and more dis-
tinctly striated. This species is represented in the collection by a large number
of specimens, in which the characters enumerated in the above description are
quite constant.

Figures 16, 16a are top and side views of a specimen, of medium size.

Formation and locality: Keokuk limestone, near Warsaw, Illinois.

Genus EDESTUS, Leidy. *

Gren. CoAar.—Maxillary bone segmented, segments beveled
anteriorly and excavated posteriorly for co-adaptation. Teeth
in form resembling those of Carcharodon; one co-ossified with
each maxillary segment.

. - Epgstus minor, Newb.
Pl. IV, Fig. 24.

TrxtH relatively small, 10 lines long, 52 lines wide at base,
3 lines thick, set saddle-like upon the edge of a flat, bony jaw,
conical in outline, acute, margins sharp, coarsely doubly crenu-
lated; sides laterally arched, giving a lenticular section to the
tooth; surface smooth and highly polished.

VERTEBRATES. 85

This beautiful and peculiar tooth is evidently similar in its general character
to that described by Prof. Leidy (Jour. Acad. Nat. Sci., Phil., 2d series, Vol. 3,
p. 159, pl. 15,) under the name of Edestus vorax, and to those upon the jaw
exhibited before the American Association, at the Providence meeting, August,
1855. Of the latter we have, as yet, no minute description. From the former
it differs in its smaller size, double crenulation and angular base. Whether
the jaw to which it was attached was segmented, as in LZ. vorax, I am not able
to say, as bit a small portion of it remains in the specimen before me. It was
apparently of dense, bony structure, thin and flat. Of the relations of the fish
which bore this tooth little can be said, except that it must have been widely
different from any forms now living. The crown of the tooth is remarkably
like, both in size, form and crenulation, that of the teeth of Hemipristis serra,

Agassiz; but the mode of its attachment to the jaw is so different that there |
could really have been no affinity between them. The teeth of Hemipristis, as |

well as those of Carcharodon, have osseous, gibbous bases, which were set upon
a cartilaginous jaw, to which they had only ligamentous attachment. In the
fossil before us the tooth was firmly cemented to a dense bony jaw. On the
other hand, to Pristis, with which similar teeth to this one have been compared,
it has some slight resemblance, as the teeth of the saw are implanted in a solid
bony structure. The fact that they are inserted in cavities is, however, an
evidence of a wide difference between /ristis and the fossil before us. As
Prof. Agassiz remarked, in reference to the jaw exhibited by Prof. Hitchcock
—similar to, if not identical with, our fossil—there is reason to believe that
this should be regarded not only as a new genus, but a new family of fishes.
Figure 24 represents a side view of this tooth, natural side.

Formation and locality: Coal Measures, Posey county, Indiana. -

CuHomatopus costatus, N. and W.
Pl. V, Fig. 17, 17a.

TretH small, laterally elongated, linear in outline; crown
surface linear, flattened, truncated at the extremities, slightly
arched on one side, straight on the other, with a prominent
carina along the arched margin and another straight one con-
necting the extremities of the former, like the string to a bow.
Along the straight and inferior edge is a ridge marked with
elevated spiral lines; the whole surface is smooth and polished,
but shows fine pores along the superior cost. The root is

86 PALHONTOLOGY OF ILLINOIS.

somewhat oblique, narrow, linear, section quadrangular, slightly
shorter than the crown.

But a single, though quite perfect specimen represents this species in the
collection. It is a handsome, highly ornamented tooth, though its affinities are
somewhat obscure. We have referred it, with some doubt, to Chomatodus,
though it is by no means certain that it will not be hereafter considered generi-
cally new. e

Figures 17, 17a represent the crown face and section, natural size.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

CHOMATODUS ELEGANS, N. and W.
Pl. V, Figs. 18, 18a, 18d.

Trxrtu of large size, laterally elongated; crown linear or long-
elliptical in outline, somewhat curved, having a prominent crest
running along the medial line, which, near the central point,
swells into a rounded tubercle or gibbosity. This mesial crest
is on one side arched, on the other side concave, being bordered
by a deep and broad furrow, which runs the entire length of
the tooth. The surface of this ridge is deeply and regularly
pitted by elongated pores or depressions, which have a trans-
verse direction. On either side of the central gibbosity they
are larger, giving to the ridge the crenulated and striated
appearance of the cutting edge of some species of Petalodus.
The base of the crown is ornamented by numerous imbricating
folds of enamel, those of the posterior descending lower than
those on the anterior surface—the former being more numerous
and finer; the anterior edge of the base of the crown is also
prettily crenulated. The root is in height nearly equal to the
crown, its anterior face nearly straight, posterior oblique.
Length, 1 inch, 7 lines; breadth, 6 lines; height, 8 lines.

This is one of the handsomest species of the genus. Jn the specimen before
us the medial crest is nearly white, while the pits upon its surface contain, at
bottom, black enamel, the basal folds on either side are also jet black. This

VERTEBRATES. 87

difference of color, with the variety and beauty of its ornamentation, fully jus-
tify us in the choice of the name given it. There is no described species with
which it is likely to be confounded.

Figures 18, 18a, 18, represent the tooth viewed from behind and above,
and a profile section, and are of the natural size.

Formation and locality: Keokuk limestone, Keokuk, Iowa.

HELopus consotipatus, N. and W.
Pl. VI, Figs. 1, la, 2, 2a.

Tootu compound, consisting of several crowns, firmly consoli-
dated upon a common root; these crowns diverge at different
angles from a common centre, and are very unequal in size;
anterior and larger one broadly conical in profile, both laterally
and transversely, irregularly oblong in outline, ends somewhat
rounded; second crown much smaller, conical in profile, with
a more or less prominent central gibbosity, oblong-linear in
outline, ends rounded; third crown smaller than the second,
arched in profile, elliptical in outline, sometimes rudimentary
and even wanting. Root nearly as broad as the principal
crown, vermicularly rugose above, roughened and bony below,
with two marked excavations beneath the larger crowns; pos-
terior margin forming a blunt edge, somewhat rounded laterally.
The enameled surface of all the crowns uniformly, somewhat
finely punctate, sometimes showing a tubercular rugosity.

There is little doubt that these teeth formed one or more medial series be-
tween the broader lateral teeth of Cochliodus. With what species of that genus
they are associated, it is at present impossible to say; and we are therefore com-
pelled to give it provisionally a distinct specific description and name. From
the other compound teeth with which it is associated, in the collection, it may
be at once distinguished by its more conical principal crown, its large, bony,
solid root, to which its relatively small and distant secondary crowns are firmly
anchylosed. There is considerable variation in the length of the root, some-
times but two, perhaps but one crown being attached to it.

Figures 1, 1a, 10, represent the superior and inferior surfaces, and side view
in outline of an elongated specimen from St. Francisville, Missouri. Figures

88 PALEONTOLOGY OF ILLINOIS.

2, 2a, a broader specimen, with but two crowns, upper and lower surfaces, from

Warsaw, Illinois.

Formation and locality: Keokuk limestone, St. Francisville, Missouri, and
Warsaw, Illinois.

Hetopus (Cocuiiopus) nosixis, N. and W.
Pl. VI, Figs. 3-6.

Terra forming a series of six, diminishing from before back-
ward, set upon a segment of a circle; the anterior one large
and strong, sub-elliptical in outline; the extremities rounded
or blunt-pointed. Crown conical in profile, with a sub-median,
prominent, ripple-like cone, underneath which is a deep sinus
filled by the root; enameled surface, uniformly, rather finely
punctate throughout. Root as high and as broad as the crown;
anterior face nearly vertical, vermicularly roughened; posterior
face higher than anterior, oblique. The smaller teeth of the
“series are similar in form to the largest, but having the median
cone less worn and more pointed.

There can scarcely be a doubt that these teeth occupied the central portion
of the jaw, in two or more rows, between the large convoluted teeth which we
have described under the name of Cochliodus nobilis. This is indicated, and
we may almost say proven, by the fact that the specimens figured plate VI,
figures 4—6, and plate VII, figures 1, 2, 4, were found impacted together—disar-
ranged, but in contact—and with some traces of the cartilaginous jaw upon
which they were once set. The character of the microscopic structure of the
crown surfaces is precisely the same in both, as is their color. Whether the
entire dental series was procured or whether a portion was lost we have no
means, at present, of determining, but the convoluted teeth seem to have been
derived from both the upper and lower jaws. There are also many more of the
conical ones than the series represented in our figure. Whether these former
numerous medial rows were on a single jaw, or were common to both, is as yet
undeterminable. As has been before remarked, a want of symmetry of these
Helodoid teeth seems to prove that there was more than one row on one, per-
haps both of the jaws. ;

Figures 3, 3a, 36, give side and top views and profile section of a large
detached tooth. Figures 4, 46, represent one of the series we have described,

————— .

a

or ee ee

VERTEBRATES. 89

seen from above and from the side, the latter in profile. Figure 4a, the ante-
rior face of the largest tooth. Figures 5, 5a, another series, seen from above
and in profile. Figure 6, a side view of a series of very small teeth. All from

the same locality—natural size.

Formation and-locality: Keokuk limestone, near Warsaw, Illinois.

CocuLiopus nopiLis, N. and W.

Pl. VII, Figs. 1-4. Pl. VIII, Fig. 1.

The specimens from which our knowledge of this magnificent species is
derived, apparently include nearly the entire dental series ; they were, however,
most unfortunately, collected without sufficient care to preserve every fragment
of all the numerous teeth found lying in contact, and no note was taken of their
relative positions; had both these particulars been carefully attended to, it is
probable we should have been able to make out the complete dentition of Coch-
liodus, and thus throw a flood of light upon the classification of the placoid
fishes of the Palzeozoic ages. As usually found, the teeth of cartilaginous
fishes are severed from their connections, and all traces of the jaws which sup-
ported them are lost. In the present exceptional instance, however, the jaws
themselves are preserved, and the teeth were in contact, though generally dis-
placed, most of them lying in a confused heap.

Jaws.—Fragments only of the jaws are visible on the specimens contained
in the collection, and such as are quite insufficient for determining their form ;
they are now thin and flattened, and much distorted, showing they had little
firmness or rigidity, and were doubtless, for the most part, cartilaginous, though
it is possible, in part ossified. They do not show a true bony structure, but
exhibit on fracture a fine granular composition, such as we have before seen
accompanying the more distinctly bony portions of the remains of cartilaginous
fishes, indicating, perhaps, a cartilage through which were disseminated innu-
merable granules of ossific matter.

The structure of these jaws is very different from that of the bones of the
ganoid fishes, which are not unfrequently met with in the Carboniferous rocks.
Judging from this evidence and the fact that the teeth of Cochliodus are almost
universally detached and scattered through the rocks containing them, with no
traces of the jaws on which they were once set, we are led to infer that Prof.
McCoy was in error in removing Cochliodus from the place assigned it by Prof.
Agassiz among the sharks, and classing it among the Pycnodonts. We may
say further, that the specimens before us afford no confirmation of the views
suggested by Prof. McCoy, that the succession of teeth was from below upward,
as in the Pycnodonts, rather than from behind forward, as in the sharks.

—12

90 PALEONTOLOGY OF ILLINOIS.

Tecth.—The group of teeth here impacted together, includes at least four
distinct and different forms, of which the surface markings, microscopic struc-
ture, color, etc., are precisely the same throughout. These are, first, large,
strongly enrolled teeth, marked with two strong, revolving ridges, separated by
a deep furrow (figs. 3 and 4, pl. VII), which correspond to the larger of the
two teeth of either ramus of the jaw, figured by Prof. Agassiz, (Poiss. Foss.
Atlas, tab. 19, jig. 14,) constituting the type of the genus Cochliodus, and the
tooth described by Prof. McCoy under the name of C. acutus, Ag., (Brit.
Palxoz. Foss. p. 621, pl. 3%, figs. 24,25). The differences between these teeth
and ours being only of a specific character. Our specimens are three times as
large as those of Agassiz, the broader ridge terminating in a rounded promi-
nence before reaching the margin; the surface of the tooth strongly wrinkled,
etc. These teeth are regarded by McCoy as the posterior pair of the lower
jaw. 2d. A narrow tooth equally convoluted, having a wedge-shaped outline
when seen from above; perhaps corresponding to the anterior pair in Agassiz’s
figure. This tooth has a single narrow and low revolving ridge, with numerous
obseure plications. 3d. Teeth nearly as long as both the preceding, (figs. 1
and 2, pl. VII), with one broad, rounded, revolving ridge near the oblique
extremity, with one or two low and narrow ones near the opposite end, and
numerous revolving wrinkles or folds upon the intermediate surface. These
teeth are somewhat unlike any heretofore attributed to Cochliodus, and proba-
bly belonged to the opposite jaw from that which bore those before mentioned ;
matching into those when in use. If the teeth described by Agassiz and
McOoy are, as supposed, from the lower jaw, these are from the upper. 4th.
Transversely elongated teeth of smaller size, in diminishing series of six,
joined by their longer sides, and in some cases retaining their relative positions.
(Pl. VI.) These teeth have more or less distinctly marked prominence or
cone upon the crown, and oblique and flattened root often as high as the crown.
Considered by themselves they would constitute one or more typical species of
the genus Helodus. They formed several rows, as is indicated by the differ-
ences which they present. In one series taken from this group (fig. 5, 5a,
Pl. VI,) the cone of the crown is more or less mammillary in form, sub-central
in position, the lateral extremities of the teeth rounded. In another series
from the same mass, (PI. VI, fig. 4,4), the cone of the crown is more flat-
tened and very eccentric, the lateral extremities obliquely truncated. A third
series consists of six (6) small, elliptical teeth, of which the crowns are arched
over without distinct cones. (Fig. 6, Pl. VI.)

The enameled surface of all these teeth, large and small, has a relatively
coarse porosity precisely the same in all, and it is impossible to resist the con-
clusion that they all formed parts of the varied dentition of a single fish. As
they are now thrown into a confused heap we can only conjecture what the

»

VERTEBRATES. 91

relative position of each form was. It seems probable, however, that the
smaller conical teeth formed several series intermediate between the larger and
broader ones, upon the symphysis of the jaw. In the living Cestracion we find
a precisely similar arrangement. The rami of the jaws are covered with a
series of broad, flattened plates, fitted for crushing only, while the mesial por-

tion of each jaw is occupied by numerous rows of small, pointed teeth, dimin- /

ishing in size from front to rear. The smaller teeth in the group before us
would, as has been remarked, if taken by themselves, be referred to Helodus,
and it is highly probable that a large number of the species of Helodus now or
heretofore described, were once associated with teeth of very different form,
some of which may be known under other names, Several rows of teeth,
forming a regular gradation of size, generally similar to those under consider-
ation, have been discovered in the old’ world, and are described in the works of
Agassiz, McCoy, etc. Prof. McCoy, in speaking of a series of this kind,
referred to Helodus levissimus, Agassiz, (Brit. Palzoz., Foss., p. 631), says,
“they diminish in size from behind forward.” This seems to us improbable,
as upon the supposition that they occupied the mesial space between the larger
convoluted teeth, that space would be broadest anteriorly; aside from this we
have the analagous arrangement of the teeth in both the Cestracionts and Hybo-
donts, as well as in all the living genera of true sharks, in confirmation of the
view that the teeth in these rows diminished in size from the front rank back-
ward. i

e ?
Formation and locality: Keokuk limestone, Warsaw and Nauvoo, Illinois.

Cocuuiopus? crassus, N. and W. = Vandel

Pl. VIII, Figs. 2, 2a.

TrxETH thick, massive, sub-quadrate in outline, the two longer
sides respectively convex and concave, one of the lateral angles
of the concave side being prolonged, the superior surface is
strongly arched from the front backward with a lateral sulcus
extending to the produced posterior angle; it is highly polish-
ed, marked with faint waved lines of growth parallel with the
convex anterior margin, and a few obscure wrinkles crossing
these. The central portion of the tooth is evenly punctate;
near the margin the enamel tubes being concealed by an
exterior coating, as is frequently the case with teeth of this

°

92 PALEONTOLOGY OF ILLINOIS.

and allied genera when but slightly worn. Antero-posterior
diameter to extremity of prolonged angle, 1 inch, 8 lines;
transverse diameter, 1 inch, 8 lines; height, 11 lines.

This fine tooth is not distinctly referable to any known genus, though com-
ing nearer to Cochliodus than any other. Waiting the discovery of other
specimens which will throw more light upon its affinities, we place it provisién-
ally in Cochliodus. Associated as it was in the rocks from which it was
obtained, with the large species of Sandalodus, described by us under the name
of S. grandis—which it resembles in its massive strength and surface mark-
ings, we have thought it possible that it might have been a portion of the same
dental series with them. This is, however, mere conjecture, which will be
confirmed or disproved by future observation.

Figures 2, 2a, represent the upper surface and profile, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

Genus ASPIDODUS, N. and W.

Gen. CuAr.—Teeth flattened, more or less arched on both
directions, variable in size and outline, sub-rhomboidal, oblong
or trapezoidal, the larger pair in each series having a trape-
zoidal outline, and being obliquely rolled, scroll-like, over the
jaw. The superior surface is: smooth or nearly so, uniformly
and rather finely punctate throughout, the edges more or less
distinctly crenulated, the inferior surface smooth or slightly
roughened, corresponding to the jaw surface on which it rested.
The smaller teeth are irregularly rounded or polygonic in out-
line, arched on both dications, resembling in form some
ancient shields.

We have combined under the above generic title a group of teeth quite
largely represented in the collection, which seem to form a connecting link
between Cochliodus and Psammodus ; a portion of them having the twisted or
rolled form similar to that of the teeth of Cochliodus, others more nearly plain,
and approaching Psammodus in form and functions. They all want, however,
the ridges and furrows which characterize the teeth of Cochliodus, and differ
from the teeth of both the preceding genera in the crenulated edges. They
evidently formed a somewhat complex system of pavement-like dentition, which
covered an arched surface in the jaws of an ancient Cestraciont.

.

VERTEBRATES. 93

Judging from the figures and descriptions before us, it seems to us probable
that Cochliodus magnus, Ag., and Helodus planus, Ag., should be separated from
their present generic connections and included in Aspidodus. Cochliodus
magnus, Ag., corresponds closely in form with some of the teeth now figured,
and it certainly wants the characteristic revolving ridges and convoluted form
of that genus. It has been suggested by Capt. Jones (Potlock’s Geol. Report,
p: 642), that Helodus planus is but a form of Cochliodus magnus.

ASPIDODUS CRENULATUS, N. and W.
Pl. VIII, Figs. 3-11.

Trrtu small, flattened thin, showing considerable variety of
form and size; being mostly trapezoidal with five unequal
- sides, one or more of the sides being sometimes rounded, a por-
tion of the series showing a deep notch on one of the sides.
Teeth forming several pairs, which occupied corresponding
positions on the opposite sides of the mouth. Of these pairs,
among the largest and the thickest is one which is obliquely
rolled or twisted—as%in Cochliodus—is narrow, trapezoidal in
outline, with one angle much produced. This was probably
the terminal tooth on each side, homologous with the largest
tooth in Cochliodus. The upper surface of all the teeth is
covered with a thick coating of nearly smooth, uniformly
pittedenamel. The articulating edges are strongly crenulated,
the inferior surface nearly smooth.

The convoluted pair of this series of teeth bear a marked resemblance to
those described by Agassiz, under the name of Cochliodus magnus, and there
can be no reasonable doubt that they are generically identical, and yet, being
longer, narrower and more revolute, they must be considered specifically distinct.

It is, perhaps, not quite certain that all the varied forms which we now
include in A.«crenulatus should be so united, but the principal pair were evi-
dently articulated with others of different form from their own and all the series
now figured have as indications of identity the common locality, pentagonal
outline peculiarly similar surface and microscopic structure.

Figures 3-11, represent 12 of these teeth, of natural size; figures 3, 3a, the
most convoluted pair.

Formation and locality: Chester limestone, Chester, Illinois.

94 PALEONTOLOGY OF ILLINOIS.

Aspipopus convo.utus, N. and W.
Pl. VII, Figs. 12, 12a.

TEETH robust, ovoid in outline as seen from above, thick and
massive, strongly revolute, having a cylindroid figure; upper
surface without revolving ridges or furrows, finely striated
transversely, uniformly filled throughout; under surface nearly
smooth.

This singular tooth scarcely corresponds to any other in the -collection or
heretofore described. In the generalities of its form and structure it approaches
most nearly to the revolute forms of A. crenulatus, and as it is derived from the
same locality, we have thought best to place it provisionally in the same genus
with that species. The only specimen contained in the collection is considera-
bly broken, so that its entire figure can not be determined from it. It is,
however, so conspicuous, from its size and form, that it seems desirable that it
should be published in order that it may be of use for geological purposes.

Figures 12, 12a, respectively, represent the upper surface and profile section,
natural size.

Formation and locality: Chester limestone, Chester, Illinois. -

Pacitopus RuGosus, N. and W.
Pl. VII, Fig. 13.

Tooru oblong or sub-elliptical in outline, posterior extremity
sub-acute, anterior truncated, strongly revolute, with two promi-
nent revolving ridges, separated by a deep central furrow ;
crown surface highly ornamented with numerous sub-equal
folds of enamel, running nearly parallel with the basal margin.
Where unworn these are angular carinz, with one broad and
one narrow, almost perpendicular, sides; upon worn surfaces
they form rounded, transverse ridges, which undulate its out-
line. The enamel pores are uniformly distributed over the
entire surface. Length, 1 inch, 6 lines; breadth, 8 lines; enam-
eled folds, half a line in breadth.

VERTEBRATES. 95

This tooth is generally similar in form and markings to Pacilodus Jonesii,

- Ag., but is much larger, and the furrow between the two prominences is cen-

tral, while in P. Jonesii it is nearest the anterior end. P. obliquus, McCoy, is
also much smaller and the ridges are angular.

Figure 13 represents a posterior upper? tooth, seen from above—natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

Pacitopus ornatus, N. and W.
Pl. VII, Fig. 14.

TreEtH flattened, slightly arched, very thin, sub-triangular or
trapezoidal in form, the posterior extremity pointed, basal
margin sinuous, lateral margins nearly straight; crown surface
raised into a low, rounded, sub-central ridge, running nearly
parallel with the posterior margin; from this the surface slopes
down gradually to the anterior end on the other side, descend-
ing into a broad, shallow furrow, which extends to the posterior
border. It is everywhere ornamented with prominent raised
lines, nearly parallel with each other and the basal margin,
about 3 to every 2 lines in width. The summits of these cari-
nee are crenulated, and their slopes transversely striated by a
kind of vermicular rugosity. Where the ridges are most
widely separated, the unworn enamel is finely tubercular;
where worn, it is dotted by the sections of these tubecles.
Length, 1 inch, 6 lines; breadth of imperfect specimen, 1 inch.

While generally similar to the other species of the group, which includes P.
rugosus, Nob., P. obliquus, McCoy, P. Jonesti, Agassiz, etc., it differs from all
these in its thin and flattened form, and in the complex character of its orna-
mentation.

Figure 14 represents posterior terminal tooth, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

Genus DELTODUS, N. and W.

,

Gen. Cuar.—Teeth of medium or large size, thick and strong,
triangular in outline, more or less arched, sometimes enrolled

96 PALAONTOLOGY OF ILLINOIS.

in the line extending from the longest-and most acute angle to
the opposite margin; crown-surface sometimes simply arched,
more generally marked by 1-3 prominent ridges, running from
the basal margin toward the longest angle. In some species
the triturating surface is also undulated by a series of trans-
verse obtuse ridges, parallel with the basal margin, and mostly
confined to the basal portion of the tooth. The crown-surface
is uniformly punctate, the size and form of the pores varying
on the different species. .

This genus is created to receive a group of teeth, largely represented in the
collection before us, and of which some species have beén described heretofore
in Europe, under the names of Cochliodus and Pecilodus. It is evident, how-

ever, that they should be separated from Cochliodus, as they are more triangular

in form and generally much less curved; and it will be seen, by a comparison
with Pecilodus, that while the forms of some species approach that of Pacilo-
dus, they are distinguished from that genus by the character of the surface.
In all the true Pecilodi the enameled surface is corrugated by distinct trans-
verse ridges, which occupy all the crown face from base to summit of the teeth,

and give them a peculiarly ornamented appearance. [See plate VIII, figs. 13 / bw

and 14.] In two foreign species of Pocilodus (P. augustus and P. marginatis)
the transverse rugee are unbroken undulations and so different from those in
the species cited as to render it doubtful whether they shonld be included in
the same generic group. One species of Deltodus now described and figured
(D. undulatus, plate LX, fig. 5,) is also undulated, but not in a manner and toa
degree inconsistent with its association .with the smoother species with which
we have classed it. Another species, however (D. cingulatus, figure 6), presents
some characters which doubtless will be considered to have generic value, and
we only refrain from separating it from Deltodus, at the present time, from an
unwillingness to make a single and imperfect tooth the basis of a generic
description. In that tooth the crown surface is composed of alternate trans-
verse bands of enamel and dentine, these bands being of nearly equal width
and running quite across the tooth, and extending from base to summit.

It is almost certain that the triangular teeth which we have referred to the
genus Deltodus were but a portion of the dentition of the fishes which wore
them, as they are undoubtedly the homalogues of the larger teeth of Cochliodus ;
but we can not, as yet, determine the character, number or position of those
with which they were associated. ,

ta

‘

.

VERTEBRATES. j 97

DELTODUS ANGULARIS, N. and W.
Pl. IX, Fig. 1.

Postrrior teeth of small size, triangular in outline, thick;
crown surface marked with a sharp, narrow, oblique keel,
which runs from the prominent posterior summit. This is

’ bordered by a broad and deep sub-central furrow, from which

the surface runs into a broad, flattened ridge, which borders
the straight side; entire enamel surface finely punctate.

Antero-posterior diameter, 1 inch.

Figure 1 represents a posterior tooth seen from above, natural size.

Formation and locality: Coal Measures, La Salle, [linois.

.
DELToDUS STELLATUS, N. and W.
Pl. IX, Figs. 2, 3, 3a.

Posterior tooth spirally revolute, obliquely triangular in
outline, both angles of the broader extremity somewhat round-
ed, a sharp, prominent keel runs from the larger basal angle

to the pointed summit. From this ridge the surface descends

abruptly to the nearest margin, more gradually into a well
defined sulcus, which runs along the opposite border ; enameled
coating is marked with a few faint lines of growth, parallel
with the broader margin, and obscure longitudinal grooves or
wrinkles, is uniformly porous throughout, the pores being rela-
tively large, angular in outline, many of them stellate ; length
1 inch, 9 lines; breadth 1 inch, 1 line.

The posterior teeth of this species will be readily recognized by their narrow
triangular form, remote transverse lines of growth, the angular keel, the longi-
tudinal plication, and particularly by their coarse, angular, sometimes stellate
porosity.

The anterior teeth are strongly revolute, transversely arched, the base round-
ed and expanded into a ring-like angle on one side, where there is a broad,
shallow, oo furrow or depression. The surface markings are similar to

—13

98 PALZONTOLOGY OF ILLINOIS.

those of the posterior teeth, except that the longitudinal ridges are less con-
spicuous, sometimes being wholly obsolete; the porosity is coarse, more or less
angular and irregular, rarely stellate.

Figure 2, represents the superior surface of a posterior tooth; figures 3, 3 a,
an anterior ? tooth; both natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

DELTODUS COMPLANATUS, N. and W.
Pl. IX, Fig. 4.

TrETH broadly triangular in outline, naftrower end termina-
ting in an acute point, the border extremity having one obtuse
angle, the other broadly rounded, slightly arched spirally, but
as compared with the associated species flat and thin. A low,
obtuse ridge passes from the angle of the broader extremity to
the pointed end; from this ridge the surface declines rapidly
on one side, very gradually on the other, to the lateral margins;
a faint rudimentary ridge being sometimes visible midway of
the broader surface, with the higher one converging to the
acute extremity; enameled surface smooth and polished, every
where finely punctate.

Figure 4 represents the superior surface in profile, natural size.

Formation and locality: Burlington limestone, Henderson county, Illinois.

DELTODUS UNDULATUS, N. and W.
Pl. IX, Fig. 5.

Posterior tooth strongly arched, triangular in outline, its
broader extremity somewhat emarginate, one of the angles
broadly rounded, the other sub-acute; a prominent rounded
ridge passes from the rounded angle of the broader end to the
acute extremity, bordered by a deep sulcus, which, starting
from the emargination of the broader end, converges to the
same point; enameled surface highly polished and shining,

VERTEBRATES. 99

undulated by broad, transverse, elevated bands separated by
narrower sulci, which give an undulated outline to the lateral
margins, and to the profile; punctation of the upper surface
strongly marked throughout. Length, 2 inches; greatest
breadth, 1 inch, 3 lines.

This beautiful species may be at once recognized by its highly polished and
shining surface, and its broad, transverse undulation. Pacilodus sublevis,
McOoy, is somewhat like it, but is smaller, less strongly marked by the trans-
verse ridges and sulci, and with a less deep longitudinal furrow.

Figure 5, represents the upper surface, natural size.

Formation and locality: Keokuk limestone, Keokuk, Iowa.

DELTODUS cINGULATUS, N. and W.
Pl. IX, Fig. 6.

TEETH narrow, wedge-shaped in outline, spirally enrolled,
the broader end obliquely rounded; triturating surface trans-
versely arched, marked with numerous conspicuous, obliquely
transverse, sub-equal ridges or belts of enamel, separated by
parallel furrows of nearly equal width; the surface of the fur-
rows is coarsely porous and reticulated, that of the ridges very
finely and evenly punctate.

In this species we have an extreme instance of the division of the triturating
surface into bands of unequal hardness, which constitute the distinctive char-
acter of Pacilodus. Here the surface is divided into broad, transverse, zone-
like bands, more than a line in width; alternations of hard, dense, smooth
enamel, and coarse, reticulated bone. The bands of harder material are most
prominent, and give to the profile an undulated outline. This interesting tooth
will, doubtless, be ultimately separated from De/todus and placed in a genus
created to receive it and its more immediate congeners. Without more material,
however, we refrain from attempting to define the characters and limits of such
a genus.

Figure 6, represents the crown surface, natural size.

Formation and locality: Chester limestone, Chester, Illinois.

100 PALEONTOLOGY OF ILLINOIS.

Detropus spATuLATuS, N. and W.
Pl. IX, Fig. 7.

Anterior? tooth obliquely spatulate in outline, spirally
curved, long and narrow; the broader end obliquely rounded,
sides converging to a simple point above, relatively thick;
crown surface strongly arched in both directions, without dis-
tinct keels or furrows, uniformly granulo-punctate throughout.

The narrow, crenate form, and simple surface, will enable
one to distinguish this species from those with which it is asso-
ciated.

In some of the specimens the base is somewhat broader, and the basal angle
common to most species of the genus begins to show itself, while there is a
slight depression of the crown along the margin of that side, the representa-
tive of the usual furrow. The outline is narrower, however, and more spatu-

late, and the whole tooth more simple, than in any other species with which we
are acquainted. The punctation of the surface is relatively coarse, and there

are raised rings about the orifices of the enameled tubes. Length, 1 inch, 8

lines; greatest breadth, 10 lines.
Figure 7, represents a large and narrow specimen, natural size.

Formation and locality: Burlington limestone, Quincy, Llinois.

DELTODUS RHOMBOIDEUS, N. and W.
Pl. IX, Fig. 8.

Posterior tooth arched, scarcely revolute, sub-rhomboidal in
outline, the broader end irregularly rounded, the narrower end
obliquely truncated; the upper surface marked with two nearly
parallel, low, obtuse, longitudinal ridges, of which one is mar-
ginal, the other central; the latter being bordered on one side
by a shallow furrow separating it from the stronger marginal
ridge, on the other by a broader and deeper groove, which
occupies the lateral interval between it and the more oblique
margins. One or more lines of growth are discernible running
paraliel with the outline of the broader end; these produce

q

a

:
$
f

VERTEBRATES. 101

little inequality of surface, but are marked by bands of- color.
The triturating surface is evenly granulo-punctate, except along
the margins of the narrower end, which are. vermicularly
roughened.

This species is distinguished from the others, now or heretofore described,
by its more oblong or rhomboidal outline, the lateral margins not converging to
a common point; the more oblique one forming another angle before reaching
the pointed extremity. The ridges of the surface are also parallel, whereas in
most other species they converge. Length, 1 inch, 10 lines; breadth at base,
1 inch.

Figure 8, represents the superior surface seen from above, natural size.

Formation and locality: St. Louis Limestone, St. Louis, Missouri.

DELTODUS GRANDIS, N. Sp.
EAL, IDG IRs) Wie

TretH of large size, thick and strong, triangular in outline,
spirally convoluted. An obtuse, angular ridge runs from the
obtuse angle of the broader extremity to the narrower end,
from which the surface falls off laterally into a deep sulcus,
which converges toward the same point; the acute angle of the
broader end is strongly elevated. The enameled surface is
highly polished and smooth, except where showing a few faint
lines of growth parallel with the broader margin. It is uni-
formly punctate throughout, and where most worn the orifices
of the enamel tubes form simple pits in a smooth surface;
where it has suffered less abrasion it is minutely shagreened by
elevated rings about their orifices.

The specimen before us affords an interesting illustration of the severity of
the duty performed by these teeth when in use, a piece having been broken
out of its most prominent part during the life of its possessor; the edges of
the fracture being rounded by subsequent wear, its bottom and sides being
coated with a new deposit of enamel.

Figures 9 and 9a, represent the upper surface and profile, natural size.

Formation and locality: Keokuk limestone, Warsaw, Lllinois.

Mh

102 PALEONTOLOGY OF ILLINOIS.

Genus SANDALODUS, N. and W.

Gen. Cuar.—Teeth of medium or large size, thick and strong,
sub-triangular or club-shaped in outline, with one and some-
times two pointed extremities; generally somewhat twisted,
slightly arched longitudinally, strongly so transversely; enam-
eled surface firmly and uniformly punctate; base deeply con-
cave both ways, curves following those of the surface of the
crown; toward the narrower end, in some species, one or two
obtuse ridges running obliquely over the tooth, as in Cochliodus.

In many respects these teeth show a resemblance to those of Deltodus and
Cochliodus, but differ from them in their narrower, straighter forms and in
wanting, as a general rule, the ridges and furrows which are such conspicuous |
-characters in these genera. It is probable that with these elongated triangular
teeth there were associated others of different form, as we know was the case
in all or nearly all of the allied genera. If so, they are doubtless represented
among the many hundreds of placoid teeth which have been taken from the
beds where these were found. Whether any sueh exist in the collection, we
can, of course, only conjecture, as the cartilaginous supports upon which they
once rested have entirely decomposed, and the teeth, separated from their con-
nections, scattered broadcast over the sea bottom. The tooth which we have
called Cochliodus? crassus, (plate VIII, figs. 2 and 2a,) with a form quite un.
like any heretofore described, has the same dense and massive structure and
precisely similar surface with the larger species of Sandalodus (8. grandis),
which is also found in the same stratum, at the same locality—near Warsaw.
It is therefore at least possible that this beautiful specimen is one of the short
intermediate teeth of that genus.

SANDALODUS PARVULUS, N. and W.
Pl. Keio

TrxtH small, thin, irregularly oblong in outline, obliquely
truncated at the narrower end, broader extremity pointed,
triturating surface slightly arched longitudinally, strongly so
transversely, finely and uniformly punctate throughout, under
surface strongly concave, smooth.

VERTEBRATES. 103

This minute species is represented in the collection by a single, though per-
fect tooth. In its very small size and the oblique truncation of the narrower
end, it differs from the species that have been described, though similar to them
in general form.

Figures 1 and 1a represent the top and side views, natural size.

Formation and locality: St. Louis limestone, Alton, Illinois.

SANDALODUS SPATULATUS, N. and W.
Pl. X, Fig. 2.

TrretH of medium size, broader extremity regularly rounded,
the other narrow, long-pointed, acute, slightly arched longitu-
dinally, strongly and regularly so transversely; enameled sur-
face coarsely and evenly punctate, and showing several curved
parallel furrows or lines of growth; length, 1 inch, 9 lines;
breadth, 7 lines; thickness, 3 lines.

This species may be distinguished, at a glance, from its associates, by its size,
its coarsely punctate, rugose and furrowed surface, and by its haying one end
broadly and evenly rounded, while the other is drawn out into a long, acute

point.

Figure 1 is a view of the upper surface.
Formation and locality: St. Louis limestone, Hardin county, Illinois.

SANDALODUS ANGUSTUS, N. and W.
Pl. X, Fig. 3.

TrxrTH small, very narrow, linear in outline, strongly arched
laterally, much more strongly so transversely; the crown sur-
face rising into a distinctly marked longitudinal ridge; surface
smooth, or roughened by the uniform and rather coarse punc-
tation.

But a single specimen of this tooth is contained in the collection, and that

may prove to be but a fragment of a larger and differently formed one.
Figure 3 represents the upper surface, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

104 PALEONTOLOGY OF ILLINOIS.

SANDALODUS CARBONARIUS, N. and W.
Pl. X, Fig. 4-5.

TEETH sub-spatulate, one side being straight, the other regu-
larly rounded, broader end rounded to the straight margin, the
opposite extremity prolonged, narrowed, upper surface gently
arched longitudinally, laterally more strongly, highest point of
the arch forming an obtuse ridge nearer the straight than the
rounded margin; all the enamel coating very finely and evenly
punctate.

All of the specimens included in the collection are imperfect, the narrower
end being broken. It is therefore impossible, as yet, to determine with accu-
racy the entire outline. We have therefore placed them in the genus Sanda
lodus, with some doubt, although, so far as shown, their characters ally them
more closely to the preceding species of Sandalodus than to any other fossil
teeth heretofore described. The general form seems to have been sub-spatulate,
considerably like that of S. spatulatus, though probably having the narrower
end less pointed. This portion of the tooth is much the thinnest, and has,
therefore, been liable to mutilation. The triturating surface is very finely and
beautifully pitted, the pits being deeper, more regularly spaced and more closely
set than in any of the teeth which have come under our observation.

Figures 4 and 5 represent two specimens from the same locality. They differ
in size, though similar in form, except that one is dextral, the other sinistral.

Formation and locality: Coal Measures, LaSalle, Llinois.

SANDALODUS La&vissimus, N. and W.
Pl. X, Figs. 6, 7, 8.

TEETH of large size, sub-triangular in outline, terminating in
long and narrow pointed extremities, strongly arched in both
directions. Near the narrow end two faintly defined ridges are
discernable, rising from the longest margin and running ob-
liquely toward the centre of the tooth; entire upper surface
smooth and highly polished, but under the lens shown to be
very finely and uniformly punctate.

VERTEBRATES. 105
This species bears a strong resemblance to S. grandis, but is more elongated
in form and is entirely without the wrinkles and folds that conspicuously mark
that species, a character which is regarded of even generic value (though, as
we think, unwarrantably,) among the similar forms of Cochliodus and Deltodus.
Figures 6, 7 and 8 represent dextral and sinistral] specimens, or those from
opposite jaws, of the natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

SANDALODUS GRANDIS, N. and W. = 3, =
Pl. X, Fig. 9.

Treta large, thick and massive; 5 inches long, 1 inch, 8 lines
wide at broadest part, 9 lines thick; broader end somewhat
rounded, with an obtuse lateral angle; narrower extremity
produced into a moderately long, obtuse point, from which a
distinct, though not prominent ridge runs along the line of the
axis of the tooth to about its middle. Crown surface strongly
arched, both transversely and longitudinally, near the broader
end, roughened by lines of growth and fine longitudinal
wrinkles; elsewhere smooth and highly polished, finely and
uniformly punctate.

The specimens from which the preceding description was taken, may be only
old and fully grown teeth of S. dxvissiémus, but they are more rounded at the
broader end, more strongly arched and show numerous distinct wrinkles and
lines of growth, while in S. devissimus the entire crown surface is smooth and
highly polished. As has been before suggested, the massive sub-quadrate tooth
which we have named provisionally Cochliodus? crassus, coming from the same
beds and showing a similar surface, may possibly have belonged to the same
fish with the teeth under consideration.

Figure 9 is taken from a specimen in the collection, which is complete with
the exception of the angular terminus of the broader extremity. The strongly
marked longitudinal ridge shown in the figure is in part due to the wear to
which the tooth was subjected while in the jaw, and consequently somewhat
exaggerates that character.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

= 4 E

106 PALAONTOLOGY OF ILLINOIS.

Genus RINODUS, N. and W.-

Grn. CHoAr.—Teeth of medium or large size, elongated in
form, with an expanded, sub-conical base, and a flattened or
furrowed crown; enamel tubes arranged in transverse rows,
producing on the triturating surface a series of transverse fur-
rows and ridges which give.it a file-like roughness.

In form and microscopic structure these teeth depart so widely from all
known living or fossil types that at present we are scarely able to offer even a
conjecture in reference to their affinities. They would seem to have been
formed rather for grinding than crushing, and in the alternation of bands of
harder and softer material in the enameled coating of the crown, we have the
adaptation of means to an end, as clearly shown as in the grinders of the
Elephant, which indeed seem to be foreshadowed in this the dentition of a
Devonian fish.

Rrnopus cALcEotus, N. and W.

Pl. X, Figs. 10, 10a, 105, 10c.

Terra laterally compressed, forming an unequal and irregu--

lar frustrum of a cone; the summit truncated, compressed and
deeply furrowed longitudinally ; base more or less excavated
beneath. The general form is very much that of a low shoe,
a resemblance which has suggested the specific name given to
it. The sides of the tooth are marked with a series of more
or less interrupted and inosculating, horizontal, raised lines and
furrows, of nearly equal breadth. The summit is occupied by
a plate of dense enamel marked like the sides, but across this
the lines run transversely, giving it a file-like surface. In the
specimens before us this enameled crown is hollowed into a
broad, longitudinal sulcus; when examined under a powerful
glass, the roughening of the triturating surface is seen to be
affected by the arrangement of the enameled tubes, which are
placed in rows side by side, forming sulci which are separated
by ridges of harder material. The base is deeply excavated

VERTEBRATES. 107

longitudinally, and the under surface shows the same peculiar
structure as the upper; length 2 inches; greatest breadth 8
lines. }

Figures 10, 10 a, 108, are top and side view and profile section, natural size;
figure 10c, magnified view of the crown surface.

Formation and locality: Hamilton group, Calhoun county, Illinois.

Grunus PSAMMODUS, Ag.

Gen. CHAr.—“Teeth oblong, wide, thick, flat above, without
cones or keels; surface porous or minutely rugose; base of the
same form as the crown, very thick, coarse, osseous.”

PsSAMMODUS POROSUS, Ag.?
Pl. XI, Figs. 1, ta, 13.

TrEeTH oblong or nearly square, the angles of one end being
right angles, of the other, one acute and one obtuse; tritura-
ting surface more or less concave, in the line of its largest
diameter; slightly arched transversely; in perfect specimens
smooth and polished, every where dotted with fine and nearly
equal pores marking the termini of the calcigerous tubes;
thickness one half to one fourth of length; base of the same
form as the crown, coarse and cellular.

The specimens in the collection which we have referred to this species, are
undistinguishable, by any well marked characters, from those described by Prof.

Agassiz. (Poiss. Foss. Vol. 3, p. 112, Atlas, Vol. 3, tab. 13).
Figures 1, 1 a, 16, give the top, side and end views, natural size.

Formation and locality: Chester limestone, Chester, Illinois.

PSAMMODUS ANGULARIS, N. and W.
Pl. XI, Fig. 2, 2a, 26.

Tretu small, thin, oblong, or trapezoidal in figure; surface of
erown plain or slightly curved, generally smooth except as

~”

108 PALEONTOLOGY OF ILLINOIS.

roughened by the uniform and relatively coarse punctation ;
base relatively thin, of the same form as the crown, but some-
what smaller; sides forming remarkably sharp angles with the
crown.

This is a thin and small species, more exact and angular in form than any
other hitherto described. The crown is bordered throughout nearly its entire
outline by a salient, acute angle, which it forms with the relatively smooth sides;
this angle is made more prominent by a narrow and shallow sulcus. The base
is very thin, giving to the tooth a less relative thickness than in any other
species known. (see fig. 2b.) The pores of the surface are relatively large,
but circular, distinct and never confluent, as in P. rugosus.

Figure 2, 2a, 2b, represent the top, side and profile, natural size.

Formation and locality: Chester limestone, Chester, Tlinois.

PSAMMODUS RUGOSUS, Ag.
Pl. XI, Fig. 3, 3a.

Tgeta oblong or quadrate in form; surface of crown plain,
slightly arched or concave, according to the place of the tooth
in the mouth; uniformly roughened by relatively large and
deep pores, which are frequently confluent, giving it a rugose
character; base, coarse and osseous, of the same form as the
crown.

The specimens in the collection which we have supposed might represent
this species, are too imperfect for satisfactory determination. They are, how-
ever, readily distinguishable from the finely punctate teeth, we ‘have referred
with doubt to P. porosus, the surface being coarser and rougher, as in P. rugo-
sus. This difference, taken in connection with the fact that they are derived
from formations which have almost no other fossils in common, has led us to
regard them as distinct.

Prof. McCoy regards both of Agassiz’s species as mere varieties, and it is
quite possible they are so, but in the teeth before us, the differences of micro-
scopic structure are so marked and radical, that conclusive evidence must be
required before they will be regarded as specifically identical.

Figures 3 and 3a, are top and side views, natural size.

Formation and locality: St. Louis limestone, Alton, Illinois.

VERTEBRATES. 109

PSAMMODUS? SEMI-CyLINDRICUS, N. and W.
Pl. XI, Fig. 4, 4a.

TrETH thick and strong, sub-semi-cylindrical in form, oblong
in outline, twice as long as wide; crown strongly arched
transversely, to a less degree longitudinally; enameled surface
occupying all the higher portions of the tooth; where unworn,
eranular and shagreen-like; where worn, regularly porous;
around the margin the rugosity partaking of the vermicular
character of the surface of the base; base transversely concave,
thinning laterally into sharp and irregular margins.

In its form this species somewhat resembles Ps. canaliculatus, McCgy, (Brit.
Pal., Foss., p. 643, pl. 3g, jig. 12.) but is at once distinguishable from it by the
absence of the plications and gibbosity of the crown, which form the marked
characters of that species.

The shagreen-like rugosity of the triturating surface, to which allusion has
been made in the above specific description, is not peculiar to this tooth, but is
common to several species of this and allied genera. It is only shown where
the enamel coating is unworn, and disappears upon the exposed portions of
long used teeth. It is due to the presence of raised rings about the extremities
of the enameled tubes, and is doubtless a provision of nature to prevent the
slipping of the teeth over the smooth surfaces of shells or other hard substances
which it was their function to crush. In worn teeth the roughness which they
retain is due to the pores or pits formed by the sections of the enameled tubes.

Figures 4, 4a, represent one of these teeth as seen from above and in profile.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

PSAMMODUS RETICULATUS, N. and W.
Pl. XI, Figs. 5, 5a.

TEETH oblong, more or less flattened, thin; crown irregularly
arched transversely, nearly straight longitudinally, slightly
depressed at the ends, showing a few remote transverse sulci;
rugosity of triturating surface nearly uniform, coarse, reticu-
lated by the intersection of short, tortuous lines and furrows,
running parallel with the longest diameter of the tooth.

—

110 PALEONTOLOGY OF ILLINOIS.

The only specimen, representing this species in the collection, is somewhat
mutilated, but still exhibits well marked characters by which it may be readily
recognized wherever found. The rugosity of the surface is much like that of
Ps. rugosus, Ag., and it also resembles that species in its transverse wrinkles
or furrows; but, unless a portion only of the original thickness of the tooth is
represented in the specimen before us, it must have been far thinner and lighter
than any form of P. rugosus which has been described.

Figures 5, 6a, represent the upper surface and a transverse section of the

tooth, of the size of nature.
Formation and locality: Chester limestone, Monroe county, Llinois.

PsAMMODUS? RHOMBOIDEUS, N. and W.
Pl. XI, Figs. 6, 6a.

TrrTa rhomboidal in outline, thick, strongly arched in both
directions; triturating surface, sub-rhomboidal, with rounded
angles, forming a prominent disc or boss, surrounded by the
roughed and irregular base. On two sides the crown is some-
what compressed, inclosing a prominent angle or ridge which
rises to the summit of the tooth. Other portions of the tritu-
rating surface are arched in both directions. The base on two
sides is much depressed, on the third less so, and on the fourth
somewhat turned up. It is rough and porous; in the central
portion of the tooth, thick, but thinning toward the edges,
which are irregular. The base is below deeply excavated,
strongly concave in the line of its shortest diameter, nearly
straight in its longest. Most of the triturating surface is uni-
formly punctate, the pores in the center being relatively small
and remote. Near the margin they are larger and more con-
fluent, ultimately merging into the vermicular roughening of
the base.

This tooth is considerably unlike those hitherto described, and as yet little
can be said in regard to its relations with them, or those with which it is asso-
ciated, in the locality where it is found. We have placed it provisionally in
the genus Psammodus because it seems most to resemble some of the varied
forms which still remain included in that genus. It is by no means certain,

PRO! hea

VERTEBRATES. PTE

however, that it has any closer affinity with the typical species of Psammodus

than with Cochliodus, Helodus, and perhaps other genera of the cestraciont

family. Doubtless, in time, material will be obtained which will permit future

paleontologists to determine its affinities with more accuracy than can be done

at present. In the hope of hastening that time the figures and descriptions of
it are now given. We have some reason to believe, however, that we have, in

this and other teeth, from the same vicinity and geological level, representatives

of one or more genera, distinct from any hitherto designated by special names,

teeth which hold an intermediate place between Psammodus and Cochliodus.

These are in addition to that under consideration, and such as should probably

be referred to the same species, those we have designated by the names of
Psammodus semi-reticulatus, Trigonodas minor, T. major, several species of
Sandalodus, ete. Of these, some, at least, depart very widely from the tile-like

teeth of the typical species of Psammodus, and no one would think of including

them in the same generic group. Others, however, such as that under consid-

eration, show perhaps sufficient relationship in their microscopic structure, and

in their broad, more or less tubular forms, to the true Psammodi, to be appro-

priately classed with them until such time as the dentition of the fishes to.
which they belong shall be more fully made out.

Figure 6, crown surface, from above; 6a, side view, natural size.

Formation and locality: Keokuk limestone, Warsaw, Illinois.

Genus TRIGONODUS, N. and W.

Gen. Cuar.—Teeth thick and strong, sub-triangular in out-
line, strongly arehed in both directions, with a central boss or
prominence, from which one or more ridges descend to the
angles or to the larger side; triturating surface uniformly and
finely punctate; inferior surface deeply concave.

This genus is established to receive a number of teeth constituting two spe-
cies included in the collection, which, with the mieroscopic structure of Coch-
liodus, seem by their peculiarities of form to be essentially distinct from that
genus. They formed strong, crushing implements, doubtless serving the same
purposes with those of the large group of Cestraciont genera, with which they
are associated in the Carboniferous limestone. In their forms they show a
marked departure from the more cemmon types of Cestraciont teeth, and ap-
proach more nearly to that of some portions of the triturating apparatus of the
Chimezeroid fishes. But we should be unwarranted in inferring, upon such

112 PALAONTOLOGY OF ILLINOIS.

slight evidence, the existence of Chimeroid sharks at the period of the depo-
sition of the Carboniferous limestone.

Trigonopus magor, N. and W.
Pl. XI, Figs. 8, 9, 9a.

TrETH sub-triangular, with one longer and two shorter sides,
the latter including the best defined angle, near which is the
most prominent portion of the tooth, the shortest sides are sub-
equal somewhat curved, longer side more or less waved, and
irregular. The central prominence forms a broad arched sur-
face from which two obtuse ridges descend, the longer one to
one of the angles, the shorter one to the long and irregular
margin. From the central prominence the surface falls off
toward the opposite angle in a broad, shallow furrow; enam-
eled surface highly polished and finely punctate throughout;
length, 1 inch, 9 lines; greatest breadth, 1 inch; height, 7
lines; thickness at centre, 4% lines.

Figures 8 and 9, represent a pair of teeth apparently from the opposite sides
of the same jaw; figure 9a, the profile from the angled side, natural size.

Formation and locality: Burlington limestone, Quincy, Illinois.

TRIGONoDUS miINOoR, N. and W.
Pl. XI, Figs. 7, 7a.

TretH half the size of 7. major, sub-triangular in outline,
shorter sides curved, longer nearly straight. Of the small
angles one is rounded, the other sub-acute; the most prominent
point of the crown, half way between the obtuse and the
rounded angle, being the summit of the arched ridge which
connects them. ‘Towards the acute lateral angle the surface
slopes down uniformly with no distinct sulcus. The surface
rising from the margin which connects the medial with the
rounded lateral angle marked with 4 or 5 sub-equal and par-

VERTEBRATES. 3

allel ridges, which arch over from the medial toward the round-
ed angle; enamel surface finely and evenly punctate; length
1 inch, 3 lines; greatest breadth 7 lines. :

This species may be distinguished from the preceding by its smaller size, by
its most elevated point being nearer to one of the lateral angles, by the absence
of the ridge running down to the longer side, and by the plication of one of
its faces.

Figure 7 and 7a, represent the crown as seen from above, and the profile
from the side of the medial angle.

Formation and locality: Keokuk limestone, Nauvoo, Illinois.

Genus HOMACANTHUS, Ag.

Gen, CHar.—Fin-spine small, rather rapidly tapering, mod-
erately arched backwards; sides flattened, converging to the
anterior face, which is obtusely keeled; sides covered with few
very coarse, longitudinal ridges, and fine striz in the same
direction; posterior margin with two rows of denticles arched
downwards.

This genus differs from Leptacanthus and Ctenacanthus in its small size, and
the sides being covered with very few, strong, nearly smooth ridges. The genus
is by no means a well defined one, but when confined to the two following spe-
cies, and the Russian Devonian one, already published, it has a sufficiently dis-
tinct facies.

HomAcANTHUS cGiBBosus, N. and W.
BUX My Wie. 1.

SPINE small, slender, strongly arched backward, narrow and
compressed throughout the upper two-thirds of its length, then
rapidly expanding toward the base till at the point, when the
ornamentation ceases, it is nearly twice as broad as in the mid-
dle; immersed base without ornament, somewhat roughened,
and irregularly conical about one-fifth of the entire length;
exposed portion marked throughout with longitudinal, tuber-

114 PALAONTOLOGY OF ILLINOIS.

cular carine, separated by surfaces which are striated; anterior
margin acutely carinated, and set with a row of small tuber-
cles distant from each other about the width of the spine at its
middle point; lateral surfaces occupied above by 3, below by
5 or 6, longitudinal carina, each tuberculated in the same man-
ner as the anterior edge, but the tubercles somewhat more
closely set; the spaces between the carine flat, and marked
with wavy, longitudinal striz; posterior border sulcated, and
each side of the sulcus set with closely approximated teeth.
At, and above the middle of the spine, these denticles are very
small, conical, contiguous, and scarcely depressed; toward the
base they become much larger, more remote and strongly hook-
ed downward. Entire length, 2 inches, 2 lines; breadth at
base, 13 lines; at base of ornamental part, 3 lines; immersed
base, 4 lines.

This species may be readily distinguished from the succeeding one by its
strongly arched form, its swollen base, and posterior denticles very small and
numerous above, larger and sparser below, while in H. ? rectus they are largest
near the summit. From the species of Homacanthus described by Agassiz and
McCoy, it is clearly distinct specifically, and perhaps generically. The genus
Homacanthus was established by Agassiz upon some very small spines from the
Devonian rocks of Europe. In their general aspect these spines show a mark-
ed resemblance to our H. gibbosus and H. rectus, but in the details of their
structure they are so unlike, it is doubtful if they should be classed together.
In the typical species of Homacanthus (H. arcuatus, Ag.), the spine has
nearly the form, though about half the size, of H. ? gibbosus; the base rela-
tively broad and irregular, the exposed posterior fluted longitudinally, bearing
numerous, sinall, depressed denticles on the posterior border. No detailed
description of these spines is given by Prof. Agassiz, and his figures are our
only guides in making the comparison of these two, represent spines with
smooth, longitudinal coste. In the third they seem to be interruptedly tuber-
cled or pectinated. In the general character given by McCoy the costz are
said to be few, strong and nearly smooth. In both the species now described
the ridges are distinctly tubercled. In each of the three spacies of Homacan-
thus, hitherto described, the denticles of the posterior border are nearly uniform
in size, and are strongly hooked downward; while in the spines under consid-
eration the denticles are very unequal in size, and unlike in form, the larger

VERTEBRATES. 115 +

ones only being distinctly depressed. These characters would seem to be suffi-
ciently marked to justify us in considering them as distinct from Homacanthus,
and as types of a new genus. From the smaller amount of material, however,
now in our hands, we have refrained from adding another to the already long
list of ill-defined genera of fossil fishes, and have placed them provisionally in
Homacanthus.
Figure 1, side view, natural size.

Formation and locality: St. Louis Limestone, St. Louis, Missouri.

Homacantuus? rectus, N. and W.
Pl. XII, Fig. 6.

Spine small, slender, straight, or very slightly arched, com-
pressed, with an elliptical section; immersed portion about one-
sixth of the entire length, narrowed, compressed laterally, hay-
ing a triangular section, rapidly drawn to a rude point below;
exposed portion marked by 6—7 rounded longitudinal costz on
either side, which are set with remote rounded tubercles,
arranged in lines descending obliquely from the anterior bor-
der, and being separated three times as far longitudinally as
laterally in the middle of the spine. The spaces between the
coste are of less than equal breadth with them, and are
obscurely striated longitudinally. The only specimen in the
collection does not fully give the form and arrangement of the
denticles of the posterior border, those of the upper portion
alone being visible. These are, however, of unequal size and
relatively very large, being nearly as long as the diameter of
the spine where they are set.

In the great size of some of the denticles this species resembles H. macrodus,
McCoy, ( Op. cit., p. 632, pl. 3 K, fig. 20,) but that species is much more curved,
broader, and has fewer longitudinal cost.

Figure 6, side view, natural size.

Formation and locality: St. Louis limestone, St. Louis, Missouri.

©116 PALEONTOLOGY OF ILLINOIS.

Genus LEPTACANTHUS, Ag.

Gren. Cuoar.—Fin-spine very long, narrow, gently arched
backwards, very gradually tapering, greatly compressed, sides
flattened; anterior face thin, keeled; surface covered with very
numerous, longitudinal ridges and strize; posterior side set with
two rows of numerous, close, small, downward-curved denticles.

LEPTACANTHUS? OCCIDENTALIS, N. and W.
Pl. XU, Fig. 2.

SprnE long, slender, gently arched backward, very much
compressed throughout, sides flat; anterior edge sharp, posterior
edge conspicuously furrowed and bordered by two rows of small,
acute, compressed and depressed hooks, of which the bases are
nearly in contact; lateral surfaces occupied by numerous sub-
equal, parallel, continuous, smooth, flattened costz, near the
base about 15 on either side, at the middle 9-10, and near the
summit 4—5, the number being increased below by the bifurca-
tion of those occupying the upper part of the spine. The
specimens before us are neither of them complete, but they
indicate a total length of about 6 inches, with a breadth at base
of about 6 lines, the average thickness being one-fourth the
breadth. ae

We have referred these spines to Leptacanthus with much doubt, as there
seems to be little probability that they are generically identical with those from
the Oolite, which Agassiz first designated by that name. It is true the general
form is similar, but the striated or obscure and confusedly costate surface of
the typical Leptacanthi must have given them an aspect widely different from
that of these spines, so uniformly and regularly ribbed throughout. The sus-
picion that these differences are generic is also strengthened by the fact that
up to the present time no teeth have been found, both in the Lower Carbonif-
erous and Jurassic rocks, which have been referred to the same genus; and it
is scarcely probably that while the fin-rays of these ancient placoids have been
met with in considerable numbers, that the much more numerous teeth could

he "a

VERTEBRATES. 117

have been overlooked. We infer, however, from the figures and descriptions
of Prof. McCoy, (British Palzxozoic Fossils, p. 633, pl. 3 G, figs. 13, 14 and 16,)
that the species which he calls Leptacanthus junceus and L. Jenkinsoni are
generically identical with ours; the latter species being distinguishable from
that before us only by the less perfect regularity of costation near the base,
greater spacing of the denticles, and the striations of the surface—fair specific
differences. If, then, Prof. McCoy’s carboniferous fin-spines are properly re-
ferred to Leptacanthus, ours should be so; but for the reasons given above it
seems in some degree probable that the reference of his specimens to that genus
was unwarranted. The resemblance which the spines before us and those of
Prof. McCoy bear to some of the more slender and compressed forms, now in-
cluded in Ctenacanthus, such as Ct. distans, McCoy, and C. gracillimus, Nob., is
very marked and is suggestive of closer relationship than has been assigned
them. These species of Ctenacanthus have been associated with the great
hybodoid spines, Ct. major, Agassiz, C. hybodoides, Egerton, etc., simply on
account of their sharing with them the inconstant and unequally exhibted
character of the tuberculation or pectination of the longitudinal costa. As we
have before remarked, this is almost too variable and superficial a character to
serve as a band of generic union between organs of which the facies are so
diverse. We would, therefore, suggest to those who, hereafter in the possession
of more ample material, may be better able to adjust the classification of these
fossil fishes, the question whether the long, slender and flattened species of

Ctenacanthus, cited above, should not be united with Leptacanthus junceus, L. .

Jenkinsoni, and the present species, in a generic group, distinct from both
Ctenacanthus and Leptacanthus.

Formation and locality: St. Louis limestone, St. Louis, Missouri.

Gunus ORACANTHUS, Neand=w. ©

ORACANTHUS PNIGEUS, N. and W.

Pl. XII, Fig. 3.

SPINE conical, short and robust, as broad at the base as high,
anterior margin nearly straight, posterior outline much curved,
anterior surface covered with relatively large stellated tuber-
cles, irregularly scattered toward the base, on the upper half
arranged in short oblique lines, extending from the anterior
border to the middle; posterior surface occupied by smaller
tubercles, without regular arrangement.

I ee EE. Wy

118 PALEONTOLOGY OF ILLINOIS.

The mass of this spine was originally cartilaginous, covered with a thin, bony,
ornamented crust, which formed a solid bony tip at the summit. In the fossil
the cartilage having disappeared, the external shell has been crushed in and
its opposite internal surfaces brought in contact. Hence, as found, the spine
is flat, and except at the solid apex, has a thickness of scarcely more than two
lines. This is a well marked species of the genus, resembling more O. abbre-
viatus, Newb., from the Devonian limestone of Ohio, than any other described.
From this it differs, however, in its less oblique base, in its distinctly stellate
tubercles, and their partial linear arrangement. In O. abbreviatus the tuber-
cles are smooth, or nearly so, and are irregularly disseminated over the surface.
Length of posterior margin, 1 inch, 3 lines; of anterior border, 2 inches; base,
1 inch, 6 lines.

Formation and locality: Keokuk limestone, Keokuk, Iowa.

Genus CTENACANTHUS, Ag.

Gen. Cuar.—Fin-spine of moderate and large size, com-
pressed, gradually tapering, moderately arched backwards;
anterior face narrow, rounded; posterior face concave, with a
moderate cavity, the lateral edges bordered by two rows of
curved denticles, inclined downwards; surface marked with
strong, longitudinal ridges and furrows, pectinated by trans-
verse scales or tubercles. The concealed base of moderate
size, rapidly tapering, finely striated.

CTENACANTHUS ANGULATUS, N. and W.
Pl. XII, Fig. 4, 4a.

SPINE small, robust, compressed, posterior outline nearly
straight; anterior border arched backward; posterior margin
flattened or slightly hollowed, half the breadth of the lateral
surfaces; anterior margin rounded below, acute above, section
a triangle having sides twice as long as the base; anterior half
of the surface of the spine (more below, less above the middle)
occupied by distinct, parallel, continuous caring, those on and

VERTEBRATES. 119

near the anterior border pectinated by very numerous trans-
verse edges, which on the posterior carinze become small, dis-
tinct, rounded tubercles; posterior half of the lateral surfaces
marked with fine, and interrupted longitudinal strize; posterior
surface finely striated longitudinally; strize reticulated; poste-
rior angles set with numerous, small, depressed hooks, separa-
ted by about the width of their bases.

This is a peculiarly exact and elegant little spine, of which the surface is
every where highly ornamented. Its most striking character is perhaps its
angularity, but the ornamentation is peculiar, and such as will readily serve to
distinguish it from any species hitherto described. The anterior surface is
occupied by relatively large and distinct costa, strongly pectinated, as is com-
mon in the genus, while about half of the lateral surfaces, and all the posterior
sulci, are marked by fine, longitudinal, interrupted, or reticulated striz. Near
the base the greater part of the lateral surface is covered by the pectinated or
tuberculated ridges, while toward the summit the striee encroach upon the
costee, and occupy most of the side. The only specimen in the collection,
though apparently representing nearly the entire length of the spine, wants
the extreme summit, and that part of the base which was buried in the integu-
ments of the back. It is 34 inches long, by 6 lines wide. The lateral parietes
of the central cavity near the base were evidently quite thin, and have been
crushed in by pressure from without.

It will be noticed that both this and the preceding species referred to the
genus Ctenacanthus are all smail and delicate in form and markings, contrast-
ing strongly with many species of the genus which have been described, espe-
cially with the large, nearly cylindrical spines, described by Agassiz and Hger-
ton under the names of C. major, C. hybodoides and C. nodosus, and we may
justly doubt whether the jong, slender, and delicate spines such as C. distans,
McCoy, and C. gracillimus, Nob., were borne by fishes generically identical
with those which carried the formidable weapons named above. While, how-
ever, we have only the spines with which to classify these ancient placoids, and
the differences which they present are rather of degree than kind, we must
be content to group together those which are generally similar, waiting the
time when the spines and teeth can be found together, and their generic rela-
tions more accurately established.

Figures 4, 4a, side and posterior faces, natural size.

Formation and locality: Chester limestone, Chester, Illinois.

120 PALAONTOLOGY OF ILLINOIS.

CrENACANTHUS? costATUS, N. and W.
Pl. XI, Fig. 5.

Spine short, robust, slightly arched backward, with an ovate
section near the base, elliptical above; basal portion once sunk
in the integuments about one fourth of the total length, irreg-
ularly pointed, smooth or finely striated; exposed portion
coated with polished enamel, strongly ribbed longitudinally;
anterior border occupied by a single broad and smooth carina,
three times the width of the cost of the sides; lateral sur-
faces occupied at base by broad parallel longitudinal ribs sepa-
rated by much narrower sulci. The external surface of these.
ribs is smooth and polished, but their sides are set with closely
approximated tubercles which give them an elegant beaded
appearance and nearly fill the sulci.

In the only specimen included in the collection a portion of the posterior
surface of the spine is wanting. Thenumber and form of the denticles which
once existed there can not, therefore, be fully determined. Above this part
are a few tubercles which seem to have formed a double row along the posterior
surface of the lower portion of the spine. The ribs are of nearly equal breadth
and are continuous throughout, except the two anterior ones, which become
obsolete before reaching the summit. _ -

Until better specimens can be obtained, or such as show the posterior denti-
cles more distinctly, a full and satisfactory description can scarcely be made
out. It is evident, however, that the specimen before us represents a strongly
marked and hitherto undiscribed species, which will be at once recognized by
its few, strong, longitudinal costz, plain and smooth in their outer faces, ele-
gantly beaded along their sides.

Formation and locality: St. Louis limestone, St. Louis, Missouri.

\

Genus DREPANACANTHUS, N. and W.

Grn. CuAr.—Fin-spines of medium or large size, more or less
compressed laterally, gradually tapering to an acute point,
strongly curved, point turned forward; anterior margin set with

_ VERTEBRATES. 421

a single row of large, flattened or conical tubercles; lateral
surfaces set with numerous small tubercles, arranged in longi-
tudinal and sometimes transverse rows; posterior margin
rounded or flattened, without hooks, sometimes carrying one
. or more rows of relatively large tubercles.

These spines, with our present imperfect knowledge of them, seem to present
some anomalous characters of special interest, as they separate them somewhat
widely from most of the defensive spines of living placoid fishes, the study of
which has thrown so much light on those found fossil. Of these exceptional
characters, the most remarkable is their reversed curve. Nearly all of the
dorsal defensive fin-rays hitherto known, of living or fossil sharks, are straight
or more or less curved backward, the point being turned toward the caudal
extremity. They are also planted obliquely in the integuments in such a man-
ner that the point is thrown backward even where they are straight, the poste-
rior margin of the exposed and ornamented portion being shorter than the
anterior. Such is the position of the spines of Spinax, Cestracion, etc., of recent
fishes, and was the position of those of Hybodus, Ctenacanthus, and most other
extinct genera, as is proved by the line of contact with the dorsal surface,
sloping upward from the convex to the concave border. This is also generally
indicated by the curvature, the position of the medullary cavity (nearer the
posterior margin), the greater degree of ornamentation along the anterior, the
presence of hooks upon the usually suleated posterior edge or face, etc. In
Drepanacanthus, on the contrary, we find the line of contact with the dorsal
surface generally plainly marked; sloping upward at an angle of 45° from the
concave to the convex margin; the medullary cavity nearest the convex edge,
and opening first there; the concave margin most highly ornamented, etc., ete.
All of which characters seem to indicate that while the base was inserted in its
normal condition, projecting forward and downwards into the integuments of
the back, the exposed portion was curved forward instead of backward. It is
true that if the position of the base was reversed, projecting downward and
backward instead of forward, the spine being thrown entirely in advance of the
base, we should then have, with the normal curvature of the exposed portion,
the line of demarcation between the ornamented summit and the plain base, as
we now find it, slanting upward from the concave to the convex border. It
may not, therefore, be now possible to determine with absolute certainty in
which of the two ways these spines were worn. The place and form of the
medullary cavity, however, and the ornamentation, seem to indicate, as before
stated, that while the base held its normal position the summit was curved for-
ward. This structure would require no change in the muscular attachments of
the base, by which the spine was elevated and depressed, while any other sup-

123 PALEONTOLOGY OF ILLINOIS.

position would require very important modifications of the ordinary apparatus
by which their movements were effected.

In their surface markings the spines under consideration resemble those of
Oracanthus, and it is probable one or more species have been described under
that name that more properly belong with those on which the genus Drepana-
canthus is now proposed; but the typical species of Oracanthus, such as O. mil-
leri, Agassiz, O. vetustus, Leidy, O. pnigeus, Nob., were more broadly conical in
form and were composed of a cartilaginous center, covered with a thin crust of
bone and enamel, which was solid only at the tip; and we have no evidence that
any of the spines of this character were curved forward at the apex or were
toothed along the posterior border. Jn Drepanacanthus, on the contrary, the
Spine was composed of dense, fibrous, bony tissue, with a pulp cavity of mod-
erate size, and the surface was not all covered with an enamel coating, but
thickly studded with spheroidal tubercles of black, glass-like enamel, and was
strongly curved forward at the summit.

The figure and description of Oracanthus pustulosus, (Agass. Poiss. Foss., Vol.
3, p. 15, Atlas, Vol. 3, Tab. 2, figs. 3 and 4,) although representing only a frag-
ment, indicate a spine very different in its aspect and structure from O. milleri,
and the other species enumerated above, and one much more like those which
we have designated by the name of Drepanacanthus. So little of O. pustulosus
is preserved that it is not easy to decide whether, like these, it was heterostrophe
or not; but the greater relative thickness of bone on what was regarded as the
posterior side of the cavity, and the crowding of the tubercles over the exterior
surface of the same region, might lead us to suspect that the convex side was
the posterior, and that it was heterostrope. The tubercles of O. pustulosus are
not fully described by M. Agassiz, but, judging from the figure, they are
spheroidal in form and ornamented by sharp carinations, just as are those of a
species Drepanacanthus now before us. If so, they are strikingly different from
those of the typical species of Oracanthus, which are conical, with a more or
less acute summit and a broad base, from which often radiate many radicles of
enamel. These reach up on to the sides of the cones, and give them the stel-
late appearance which they usually, though not constantly, present.

If other and more complete specimens of O. pustulosus should confirm the
conjectures we now make in reference to its curvature and ornamentation, it
would be a well-marked, and even typical species of the genus Drepanacanthus.

DREPANACANTHUS ANCEPS, N. and W.
Pl. XI, Fig. 8.

Spine small, much curved and compressed throughout its
entire length; section lenticular, with acute edges; width near

VERTEBRATES. 123

base 6 lines, thickness 1 line; concave margin acute, and set
with a line of relatively large tubercles; convex border acutely
carinated, without tubercles but finely striated longitudinally;
lateral surfaces bearing numerous small, round, smooth tuber-
cles, near the concave border, densely crowded and without
linear arrangement, toward the convex border, especially
below, they are also numerous, though less crowded than along
the opposite edge, their nearest margin forming about three
longitudinal lines. Those more remote are smaller and are
dispersed in short, transverse lines. The median half of the
lateral surface bears only a few minute tubercles, and like all
the other portions of the surface between the tubercles is finely
striated longitudinally. The position, size and form of the
pulp cavity is scarcely determinable from the only specimen
before us. It is apparently situated, however, nearest the con-
vex border. The ornamentation of the surface descends much
lower on the concave than on the convex border; the line lim-
iting the ornamentation—the line of junction with the surface
of the back—rising from the concave toward the convex bor-
der at an angle of about 45°.

The resemblance of this spine to some species of Oracanthus, both in general
form and ornamentation, is so strong that, were it not for the fact that the line

of junction with the dorsal surface was inclined upward from the concave edge,
we should scarcely dare separate it from them.

Formation and locality: Coal Measures, Springfield, [linois.

DREPANACANTHUS GEMMATUS, N. and W.
Pl. XIII, Fig. 1.

Sprnz large and strong, 10 to 12 inches in length, one in
width at base, gradually narrowed to the apex, which is
strongly curved forward, much compressed throughout, section
near the base a long ellipse, truncated anteriorly, nearer the
summit the sides are flat and parallel, the anterior border
rounded, posterior margin occupied by a broad and shallow

124 PALEONTOLOGY OF ILLINOIS.

sulcus, bounded by prominent salient angles without ‘denticles |

and divided in the centre by a low but distinct continuous
carina; anterior margin rounded and set along the median line
with a row of round flattened tubercles about a line in diame-
ter, and separated by intervals of equal or slightly greater
breadth. On either side of this larger row of tubercles is a
second of about half their size below, of nearly equal size above,
behind these are, on either side, 20 to 25 longitudinal parallel
rows of similar, but smaller, tubercles, which progressively
diminish in size to the posterior or convex border, and are very
uniformly distributed over all of the lateral surfaces. These
tubercles are accurately arranged in longitudinal rows, most of
which are continuous from base to summit. They also exhibit
an imperfect transverse alignment. Those of the anterior me-
dian line are flattened and smooth, as though somewhat worn,
but the others generally, and these partially, are beautifully
ornamented by numerous, sharp, converging carinz, which rise
from the base, and, when not obliterated, cover the entire sur-
face. They are stringent on the upper side of the tubercles,

the interval between the tubercles seems to have been smooth

bone without enamel, the tubercles having the appearance of
globules of brilliant black glass, and look as though they had
exuded through pores in the bone, and had congealed on the
surface, studding it with gems. Under the lens these orna-
mented globules are exceedingly pretty, and have suggested
the specific now given. On some of them the raised lines

have a spiral arrangement giving them the appearance of seeds
of the Chara.

That part of the spine which was enveloped in the integuments partakes of
the general curve of the exposed portion, its sides are flattened and smooth,
and converge to form a sub-acute edge in front, on which is a tubercular excres-
sence as large as half a pea, just below the first of the enameled tubercles.
The posterior border of the basal portion is deeply sulcated to its extreme
point by the continuation of the pulp cavity, which was apparently open pos-
teriorly from the point where the ornamentation ceases. The margins of this

VERTEBRATES. : 125

“sulcus are thin and sharp, and are usually moré or less broken. The smooth
and flattened surfaces of the base seem to indicate some kind of an articula-
tion, and it is perhaps possible that bony or cartilaginous guides were applied
on either side, between which the spines were firmly held during their eleva-
tion or-depression. This would give an accuracy of movement and a firmness
scarcely inferior to that afforded by the gingylmus articulation of the dorsal
spines of the Stluroids. a

Figure 1, represents the side view of a spine broken at either end; 1a, trans-
verse section; 16, an enlarged tubercle of the anterior border; 2, a nearly per-
fect base of another specimen.

Formation and locality: Keokuk limestone, Keokuk, Lowa.

DREPANACANTHUS? STELLATUS, N. and W.
Pl. XI, Fig. 7.

SPINE small, strongly curved forward, with an elliptical sec-
tion above, oval below; convex margin rounded and ornamented
with three rows of relatively large, longitudinally remote,
compressed stellate tubercles; concave margin rounded and set
with a single row of large, conical, pointed, stellate tubercles,
largest toward the base of the spine; lateral surfaces regularly
arched, with numerous longitudinal rows of small, conical or
laterally compressed tubercles, most distinct on thé anterior
border, separated longitudinally by intervals of twice their
diameters, laterally closely approximate, forming oblique, trans-
verse lines. In the middle of the spine there are about fifteen
longitudinal rows of small tubercles on either side, more below,
fewer above. The large tubercles of the convex (posterior?)
border are separated longitudinally by spaces of twice their
longest diameters. Transversely they are in apposition, form-
ing short transverse lines of three tubercles each.

We have included this spine in Drepanacanthus with some hesitation, as the
imperfection of the only specimen in the collection is such as to leave several
important points in its structure in doubt If, as we have supposed, the curve
of the summit was forward, as in Z. gemmatus, it would naturally fall into the
‘same genus with that spine; for although the tubercles of the concave border

=i “? “conclusive, however, and may be fallacious. If so, this would constitute the

126 PALAONTOLOGY OF ILLINOIS.

are much higher and more tooth-like, and the flattened and keeled convex bor-- *
der of Z. gemmatus is here wholly wanting, still the style of ornamentation is so
similar that, with the striking character of a strong reversed curve in common,

it would be difficult to find good cause for their separation.

Unfortunately the specimen before us wants the base, without which the
question of its curvature can only be conjecturally decided. The facts which
have led us to suspect that the curve of the tip was forward are: 1st. On the

“concave side of the spine the bony wall of the central cavity is much thicker
*, than on the convex side, on which the pulp cavity runs out some distance above
the base. 2d. The tuberculation of the lateral surfaces become stronger toward
the concave border, fading out toward the convex. The natural inference from
these facts is, that the curve of the spine was reversed, as in most others; the
posterior wall is thinner than the anterior, and is broken through above the
base; the tuberculation of the lateral surfaces is, in most or all allied spines,
strongest on or near the anterior border. These indications are not wholly

type of a new genus, as, though allied to Oracanthus, Asteracanthus and Myria-.
‘-canthus, perhaps in an equal degree, it could be united with neither of them.
| From the first it is distinguished by its more slender form and the denticles of

edt

the concave border. According pretty well with Asteracanthus in general form
‘© (if not reversely curved) and in its stellate tubercles, it is separated from that
genus by the diversity in size, form and arrangement of its tubercles, and its
geological position. With Myriacanthus it agrees in the variety of its orna-
mentation, but not in its form nor geological place. Other specimens will be
required. before its relations ean be fully determined.

Formation and locality: Keokuk limestone, Warsaw, I1linois.

CTENOCANTHUS GRACILLIMUS, N. and W.
Pl. XIIl, Fig. 3.

SprnE very long and slender, (9-12 inches long, 4-5 lines
wide) gently arched, much compressed, scarcely more than a
line in thickness with a lenticular section; anterior margin
acute, posterior edge truncated below, above sulcated longitu-
dinally, and set with two rows of acute, compressed, strongly
depressed hooks, of which the bases are contiguous; each side
is ornamented with, about 10 below, 15 above, nearly equal
continuous, parallel, somewhat flattened, longitudinal carinz;

VERTEBRATES. 127

“which are near the summit all smooth. The anterior medial

carina throughout the entire length of the spine, and toward
the base 3-4 of the anterior lateral carinze ornamented with
numerous, obliquely transverse, prominént rings; those of the

lateral carinee passing into tubercles and becoming obsolete up-
ward.

This is a remarkably slender, as well as beautiful, spine; the ornamentation
being exceedingly neat and sharply defined. It is evidently closely allied to
C. distans, McCoy, from the Mountain limestone of Armagh, Ireland, which is
nearly as slender, and in its general aspect must be very similar. From the
description and figure of C. distans, given by Prof. McCoy, (Brit. Palxozoic
Fossils, p. 625, pl. 3K, fig. 15), I infer, however, that there are well marked
differences between the American and European fossil, which will readily serve
to distinguish them. In C. distans the form is somewhat more robust and
more curved, the teeth of the posterior margin less numerous and less depress-
ed, and the lateral longitudinal carina, instead of being as in our fossil nearly
all smooth, are all crenulated by transverse rings or tubercles.

From the other species of Ctenacanthus, described by McCoy, Agassiz and
others, that before us is so widely separated that no comparison with them is
necessary.

Formation and locality: St. Louis limestone, St. Louis, Missouri.

SYNOPTICAL TABLE

OF VERTEBRATES DESCRIBED IN THE FOREGOING PAGES.

Class PISCES.
OrpvER GANOIDEA.
Family LEPIDOIDEA.

Genus PAL AONISCUS.

P. peltigerus, N. and W. Coal Measures.

Family C@LACANTHI.
Genus RHIZODUS.

. occidentalis, N. and W. Coal Measures.

OrnpER PLACOIDA.
Family HYBODONTID.
Genus CLADODUS.

; pln 7
C. robustus, N. and W. Sub-carboniferous. ~~ / ‘~

C. micropus, N. and W. Sub-carboniferous. “ , ~

C. spinosus, N. and W. Sub-carboniferous. 77 4

U

SSeS

Be

2 i

aaaaaaqananan

PP

VERTEBRATES.

stenopus, N. and W. Sub-carboniferous.

. mortifer, N. and W. Coal Measures.
. magnificus, Tuomey. Sub-carboniferous.

angulatus, N. and W. Sub-carboniferous.
. zygopus, N. and W. Sub-carboniferous.
. ferox, N. and W. Sub-carboniferous.

| politus, N. and W. Sub-carboniferous.

. costatus, N. and W. Sub-earboniferous.

. turritus, N. and W. Sub-carboniferous.

| grandis. N. and W. Sub-carboniferous.

. lamnoides, N. and W. Sub-carboniferous.
. gracilis, N. and W. Coal Measures.

GENUS DIPLO DUS.

. latus, Newb. Coal Measures.
. compressus, Newb. Coal Measures.
. incurvus, N. and W. Sub-carboniferous.

. duplicatas, N.and W. Sub-carboniferous.

Genus CARCHAROPSIS.

. Wortheni, Newb. Sub-carboniferous.

Family PETALODONTIDZE.
Genus PETALODUS, Owen.
destructor, N. and W. Coal Measures.
linguifer, N. and W. Sub-carboniferous.
Genus PETALORYNCHUS, Ag.

striatus, N. and W. Sub-carboniferous.
—li

150 PALZONTOLOGY OF ILLINOIS.

Genus CTENOPTYCHIUS, Ag.

Ct. semicircularis, N. and W. Coal Measures.

Genus ANTLIODUS, N. and W.

A. robustus, N. and W. Sub-carboniferous.

' A. mucronatus, N. and W. Sub-carboniferous.
A, parvulus, N. and W. Sub-carboniferous.
A, similis, N. and W. Sub-carboniferous.

A, cucullus, N. and W. Sub-carboniferous.
A. politus, N. and W. Sub-carboniferous.

A. minutus, N. and W. Sub-carboniierous.
A, simplex, N. and W. Sub-carboniferous.
A, sulcatus, N. and W. Sub-carboniferous.

Genus DACTYLODUS, N. and W.

D. princeps, N. and W., (type). Sub-carboniferous.
D. lobatus, N. and W. Sub-carboniferous.
D. inflecus, N. and W. Sub-carboniferous.

Genus POLYRHIZODUS, McCoy.

P. porosus, N. and W. Sub-carboniferous.
P. dentatus, N. and W. Sub-carboniferous.
P. ponticulus, N. and W. Sub-carboniferous.

Genus CHOMATODUS, Ag.

Ch. gracillimus, N. and W. Sub-carboniferous.
Ch. cultellus, N. and W. Sub-carboniferous.
Ch. pusillus, N. and W. Sub-carboniferous.
Ch. affinis, N. and W. Sub-carboniferous.

ee a et

VERTEBRATES.

Ch. angularis, N. and W. Coal Measures.

Oh. molaris, N. and W. Sub-carboniferous.

Ch. thultiplicatus, N. and W. Sub-carboniferous.
Ch. costatus, N. and W. Sub-carboniferous.

Ch. elegans, N. and W. Sub-carboniferous.

Ch. loriformus, N. and W. Sub-carboniferous.

~

aS

~

Family CESTRACIONTIDZ.
Genus ORODUS, Ag.

O. multicarinatus, N. and W. Sub-carboniferous.
O. plicatus, N. and W. Sub-carboniferous.

. elegantulus, N. and W. Sub-carboniferous.

. ornatus, N. and W. Sub-carboniferous.

. tuberculatus, N. and W. Sub-carboniferous.
.mammilaris, N. and W. Sub-carboniferous.

. minusculus, N. and W. Sub-carboniferous.

. minutus, N. and W. Sub-carboniferous.

S281. SoS

Genus HELODUS, Ag.

H. biformis, N. and W. Sub-carboniferous.

H. elytra, N.and W. Sub-carboniferous.

H. coniculus, N. and W. Sub-carboniferous.
HT. compressus, N. and W. Sub-carboniferous.
H. carbonarius, N. and-W. Coal Measures.

H. sulcatus, N. and W. Sub-carboniferous.

H. crenulatus, N. and W. Sub-carboniferous.
H. denticulatus, N. and W. Sub-carboniferous.
H, nobilis, N. and W. Sub-carboniferous.

HT. consolidatus, N. and W. Sub-carboniferous.
H. politus, N. and W. Sub-carboniferous.

HT, undulatus, N. and W. Sub-carboniferous. -
FT, limax, N. and W. Sub-carboniferous.

ad
Pots)
to

PAL.ZLONTOLOGY OF ILLINOIS.

HH. denshumani, N. and W. Sub-carboniferous.
H. angulatus, N. and W. Sub-carboniferous.
H. gibbosus, N. and W. Sub-carboniferous.*
H. placenta, N. and W. Sub-carboniferous.

Genus COCHLIODUS, Ag.

C. nobilis, N. and W. Sub-carboniferous.
C. crassus, N. and W. Sub-carboniferous.

Gunus ASPIDODUS, N. and W. _

A. crenulatus, N. and W. Sub-carboniferous.
A. convolutus, N. and W. Sub-carboniferous.

Gove SANDADADUS IN amd awe

S. levissimus, N. and W. Sub-carboniferous.
S. carbonarius, N. and W. Coal Measures.
S. spatulatus, N. and W. Sub-carboniferous.
S. grandis, N. and W. Sub-carboniferous.
S. parvulus, N. and W. Sub-carboniferous.
S. angustus, N. and W. Sub-carboniferous.

Grnus PSAMMODUS, Ag.

P. porosus, Ag. Sub-carboniferous.

P. angularis, N.and W. Sub-carboniferous.

P. rugosus, Ag. Sub-carboniferous.

P. semicylindricus, N. and W. Sub-carboniferous.
P. rhomboideus, N. and W. Sub-carboniferous.

FP. reticulatus, N. and W. Sub-carboniferous.

Genus TRIGONODUS, N. and W.

T. major, N. and W. Sub-carboniferous.
T. minor, N. and W. Sub-carboniferous.

hac Jet las aaa.

VERTEBRATES. 133

Gznus PCECILODUS, Ag. -

lig ornatus, N. and W. Sub-carboniferous.
P. rugosus, N. and W. Sub-carboniferous.

Gunus DELTODUS, N. and W.

. grandis, N. and W. Sub-carboniferous.
stellatus, N. and W. Sub-carboniferous.

. undulatus, N. and W. Sub-carboniferous.
rhomboideus, N. and W. Sub-carboniferous.
. cingulatus, N. and W. Sub-carboniferous.
spatuiatus, N. and W. Sub-carboniferous.
angularis, N, and W. Sub-carboniferous.

. complanatus, N. and W. Sub-carboniferous.

Sis o> 5 os

Family CHIMEROIDEE.

_ Genus RINODUS, N. and W.

Tt. calceolus, N. and W. Devonian.

RELATLONS UN CHE RETRIN.

Grnus EDESTUS, Leidy.

E. minor, Newb. Coal Measures.

FIN SPINES.

: ‘Genus ORACANTHUS, Ag.

ers eee a a a a
« * , ¥

O. pnigeus, N. and W. Sub-carboniferous.

.

PALAONTOLOGY OF ILLINOIS.

Genus LEPTACANTHUS, Ag.

L. occidentalis, N. and W. Sub-carboniferous. ~

Genus CTENACANTHUS, Ag.

Ct. gracillimus, N. and W. Sub-carboniferous.
Ct. costatus, N. and W. Sub-carboniferous.
Ct. angulatus, N. and W. Sub-carboniferous.

*

Genus HOMACANTHUS, Ag.

HH, rectus, N. and W. Sub-carboniferous.

H. gibbosus, N. and W. Sub-carboniferous.
Genus DREPANACANTHUS, N. and W.

D. gemmatus, N. and W. Sub-carboniferous.
D, stellatus, N. and W. Sub-carboniferous.
D. anceps, N. and W. Coal Measures.

DEBMAL TUBERCLES.

Genus PETRODUS, McCoy.

P. occidentalis, N. and W. Coal Measures.
P. acutus, N. and W. Coal Measures.

—

SUPPLEMENT

a

TO THE DESCRIPTIONS OF VERTEBRATES.

BY PROF. EDWARD D. COPE.

Class REPTILIA.

Sub-class BATRACHIA.

Orver XHNORHACHIA.
Genus AMPHIBAMUS, Cope.

AMPHIBAMUS GRANDICEPS, Cope.
Pl. 32, fig. 8, and cut on p. 136.
Amphibamus grandiceps, Cope, (Proc. Acad. Nat. Sci., Philad., 1865, p. 134.)

The recent additions to our knowledge of the air-breathing vertebrates of
the Carboniferous period, are of great interest to the comparative anatomist, as
furnishing new points in the series of structures between the Ganoidea and
Lacertilia, or new “ generalized” types combining the structures of these and
of the Batrachia.

Notr.—A single specimen of the Batrachian here described is in possession of Mr.
Joseph Even, who has kindly placed it temporarily at the service of the Survey. It
was discovered by him near Morris, Grundy county, Illinois, in a bed belonging appa-
rently above the middle of the Coal Measures. It is imbedded in a concretion of brown
ironstone. The cavities left by the bones are occupied by a white friable mineral,
which has probably percolated into them.—A. H. W.

fy ad ip a yi es eo) a a ee eee

136

+h

Amphibamus grandiceps, (mag. 2 diam.)

The aboye cut is pinen to illustrate more clearly some points of structure. not readily shown in a
shaded engraving. It, however, represents he little scales of the right palpebra, above the marginal
row, too large and too seattering.

} Be.

VERTEBRATES. 137

This animal combines with its Batrachian a few Lacertilian characters, having
some resemblance to Dawson’s genus Hylonomus, and much affinity with Prof.
Wyman’s Raniceps Lyellii. Its squamous integument and narrow nasal roof
give it the somewhat Lacertilian physiognomy, more especially Geccotian, in
its broad cranium and orbits, its large marginal palpebral scales, and rather
short digits. Its true affinities are indicated by the presence of two premaxil-
laries, with a squamoso-postorbital arch, as in Labyrinthodontia, some Batrachia
Gradientia, and Crocodilia ; its quadratojugal arch, as in Labyrinthodontia and
Batrachia Salientia; its posteriorly directed oblique quadratum and lack of
ribs, as in Batrachia Salientia; its probably short pelvis, short separate bones
of the leg and fore-arm; its opisthoczelian dorsal vertebra, and long caudal
neural spines, as in Batrachia Gradientia. It is then the type of a group inter-
mediate between the Labyrinthodontian and Gradient Batrachians, distin-
guished from the former by the opisthoceelian vertebra, absence of ribs, and
pleurodont dentition; and from the latter by the scaly integument, absence of
ribs, and structure of the nasal and pre-frontal regions. But one genus of
Salamanders, Glossolega, has a similar os fronto-squamosal or posterior zygo-
matic arch. A ribless type might, however, well exist among G'radientia, when
we consider the great difference between their development in Plewrodeles on
the one hand, and Amphiuma on the other. From the Salientia the dentige-
rous mandible, squamosal arch, form of vertebrz, sacrum and extremities, etc ,
widely distinguish it. To the Batrachian orders Labyrinthodontia, Gradientia,
Gymnophidia and Salientia, the present may be added, under the name Xen-
orhachia.

The general form of the skull is much that of a frog, and large in proportion
to the size of the animal; its length is one-half that of the spinal axis from the
occiput to the middle of the sacral region, and five-sixths its own breadth in
the flattened specimen. The outline is not broadly rounded, as is usual among
Salamanders, but is slightly contracted, as in many frogs. The orbits are
large, regularly rounded their longitudinal diameter one and one-half times the
frontal width; their point of nearest approach is behind, opposite the position
of the iris; one diameter, measured obliquely in advance of each, extends a
little beyond the common premaxillary suture.

The premaxillary bones have considerable horizontal extent, terminating
opposite the narial openings, each bearing eleven or twelve teeth. Their nasal
spines were in close contact, and do not appear to be prolonged backwards, as
in most Gradientia. The external nares are rather widely separated, as in
most Gradientia, the integument, which they pierced, roofing a large space
between the median and peripheric bones of the muzzle. The roof of the nasal
cavities is a truncate cuneiform plate, whose apex joins that of the premaxil-
laries. Its composition can only be conjectured, from the appearances pre-

—18

138 PALEONTOLOGY OF ILLINOIS.

sented by the specimen. It may be a superior ethmoid plate, as in the frogs
Borborocetes and others, or, more probably, a united or separate pair of free
frontal, as in Dactylethra or Rana. There is no trace of the composition of
nasals and frontals, which occurs in the Gadientia, nor is such an arrangement
probable, in view of the regular elongate cuneiform outline of this singular
piece. A moderately distinct suture, crossing the front at the anterior third
of the interorbital space, which presents a regular convexity forwards, appears
to be the anterior border of the frontal; the latter can scarcely be an interorb-
ital plate of ethmoid, as it appears to unite behind by suture with the parietals.
There are bosses on the pre-frontal region, indicating pre-frontal or ‘‘ lachry-
mal” bones, similar to those in Sceloporus and other Lacertilian genera.

What may possibly be the coronal suture, since it appears to be too regular
to be a fracture, crosses the narrowest part of the interorbital space. It is a
zigzag, presenting posteriorly a median angle, and one on each side. The pos-
terior zygomatic arches are strong, and bound a cranial plane, which is broader
than long, and exhibits nearly parallel lateral outlines. The probably small
“erotaphite foramina” of the temporal fossz appear to have been roofed over
by perhaps the strong scales of the cranial integument. The quadratum is
convex externally, and is directed obliquely backward to opposite the occiput;
it is strongly concave in its posterior outline, indicating a large auricular
meatus. Whether this was covered by scales or by an exposed tympanic drum,
cannot be determined. The quadratojugale is broad and strong. The postorb-
ital arch is continuous with the quadratum; the breadth of the two equals the
frontal width. The angular process of the mandible is but little prolonged
beyond the quadratum. The maxillary is toothed, at least as far as opposite
the malar process.

The dentition is pleurodont; the teeth are only visible on the mandible and
the outer edge of the upper jaw; they are there of but one kind, small, closely
set, acute-conic, not compressed, hollow, and without any inflections of the
enamel.

The integument of the head was squamous. The scales appear not to have
been imbricate, and were perhaps more dense on the posterior regions, where their
position is occupied by the white material mentioned in Prof. Worthen’s note,
which has here asomewhat ganoid appearance. They were more elongate on the
muzzle. There appears to have been a distinct superciliary, and a postorbital row,
as weli as a series on the border of the upper lip. A whorl of elongate scales,
arranged like the pieces of an arch, surrounded the one on each side which
marked the crotaphite foramen. In the specimen these are connected by a
suture or line, which is regularly convex posteriorly. The superior palpebree
were covered by small separated scales, as are seen among Geccos and Anoles,
and were bordered by a larger and continuous series, of about fourteen sub-

VERTEBRATES. 139

quadrate scales. These have evidently bordered the lid, extending transversely
across the orbit, and were not sclerotic scales, which are arranged round the
pupil as a centre. 4

The vertebral column is much injured, especially in the cervical region.
The dorsal vertabrze appear to have been short, and probably thirteen in num-
ber between the interscapular and sacral regions. They appear to have been
constricted medially. Traces of ribs or of transverse processes are not to be
found. The impression of a sacral vertebra is distinctly preserved. The cau-
dal vertebrae were perhaps without osseous centra, as no definite impressions
can be traced, and their place is occupied by the matrix. There are traces of
osseous neural arches, perhaps similar to those of Archegosaurus, and apparently
disconnected, long, compressed neural spines, and slender pleurapophyses; the
. latter were probably united as chevron bones. Of the former, twelve very dis-
tinct impressions may be counted to the sacral region; the posterior are most
slender, the median most elevated, the anterior lower and of greater longitudi-
nal extent. They are more expanded in the direction of the axis of the body
near their superior extremities, and evidently supported a flattened natatory
tail, as th.t of Protonopsis. These neural spines were continued on the poste-
rior third of the dorsal series. The visible, which is probably the greater part
of the tail, enters the remainder of the column two and a quarter times, by
measurement.

‘Sternal and hyoid pieces are not recognizable, though sundry fragments are
no doubt to be referred to these regions. An impression resembling that of a
raniform scapula, was probably made by that piece. The anterior limbs were
short and weak. The humerus is slender; its length equals the distance be-
tween the centres of the external nares; it is apparently not much dilated, nor
furnished with a process proximally, but is dilated and grooved distally, and
has no condyles. The ulna and radius are separate and slender; the distal ex-
tremities of these, with the remaining bones of the anterior limbs, have been
lost. ;

_ Of pelvis nothing is recognizable. The femur is slender, much dilated dis-
tally, slightly curved in the posterior direction, and without condyles. Its
length is equal to the breadth of the cranial table.

The tibia and fibula are one-half the length of the femur, are slender, most
dilated proximally; the antero-exterior bone is a little longer, not’ in contact
with the inner distally, which relation I believe to be normal. The tarsus was
probably cartilaginous, as in Protonopsis (Menopoma, ) a faint impression of the
outer border remaining. It was broader than long, and without heel-like pro-
jections.

While the great shortness of the lower leg is a Salamandrine peculiarity, the
length and slenderness of the digits are quite Lacertian. The leg being

140 PALAONTOLOGY OF ILLINOIS.

extended backward, the exterior or first digit is shortest, and a little less than
the second. This is equal to two and one-half phalanges of the fifth (reckoning

from its base) or the proximal pair of phalanges of the fourth. The fifth is a

little shorter than the third, which is scarcely equal to the three proximal
phalanges of the fourth. The number of phalanges 3—3—4—5—4: among
the Salamanders the last two numbers are usually 4—3. They are without
condyles, but exhibit one or two emarginations at their articulating surfaces.
The length of the basal phalanx of the first digit is two-thirds that of the second ;
the latter equals that of the fifth and the second phalanx of the fourth; these
are very little shorter than the basal of the third and fourth. The terminal
phalanges are elongate acute, those of the first and fourth slightly curved.
They are much less obtuse than in Salamanders, and the animal has probably
had weak claws; of these no trace remains.

A few traces indicate that the dermal integument was covered, on the ante-
rior part of the body, at least, with small and sub-granular scales. There have
been abdominal scales arranged in narrow imbricate series, directed inward and
posteriorly. Traces of plates are wanting, excepting a small fragment lying
beside the cervical vertebrae.

The length of this species from the sacral centre to the interscapular region
was 13 lines; from the latter point to the end of the muzzle, 12 lines; to the
occipital border, 4-5 lines. Longitudinal diameter of orbit, 3 lines; frontal
breadth, 2 lines; from border of orbit to border of nostril, 1-5 lines; breadth
of cranial table, 3-75 lines. Length of humerus, 3 lines; of femur, 3-6 lines;
of tibia, 2-3 lines; of fifth digit, 2-75 lines; of fourth. 4—2 lines; of first, 1-8
lines. The portion of the tail preserved measures 5—2 lines.

If we compare the peculiarities of this genus with those of the Batrachia of
the same period, we find it to be distinguished, independently of the ordinal
characters, from such genera as Osteophorus, Melosaurus Sclerocephalus, Xestor-
rhytias, Baphetes and Brachyops, by the absence of the sculpturing of the cranial
bones, the lack of dermal shields, characteristic of most of these, and by the
presence of cranial and palpebral scales. The crania of the first genera are
much more elongate, and imitate those of some Crocodiha. Similar differences
exist between the Illinois Butrachian and Dendrerpeton, Owen; the latter pos-
sesses, also, a double row of teeth. Hylonomus, Dawson, supposed to possess
Lacertilian affinities, exhibits ribs and biconcave vertebrae. The ribs of Teler-
peton will distinguish it also. The only genus as yet known to approach closely
that under consideration has been described by Prof. J. Wyman under the
name of /aniceps.* This animal is only known from a study of the inferior
aspect of a portion of the skeleton ; nevertheless it is certainly differe:.t, being

* Silliman’s Journal Sci. Arts, 1858, p. 158.

VERTEBRATES. 14]

.
nearly double the size, and having relatively longer and stronger anterior limbs.
The angles of the mandible appear to have been considerably more incurved
than in the Illinois species. They may have belonged to the same genus; in
that case the name here given will not prove superfluous, as the older appella-
tion was previously applied to a genus of Gadid fishes.

The name Amphibamus grandiceps has reference, first, to its two modes of
progression ; its flattened oar-like tail enabled it to swim in the waters of the
swamps of the coal period, and its elongate, clawed digits indicate ambulatory
power; perhaps it climbed upon the low limbs of the Sigillariz that rose above
the water. The animal was most probably nocturnal in its habits. The humors
of the eye could not have escaped far beyond their natural envelopes, so that
the subsequently formed limestone has been hardened, and so fractured in
nearly the form of the ball. On the fractured surface, below and under the
remaining palpebral scales, the mineral is distinctly blackened, as by the piy-
mentum nigrum; below the margin of the lid this is interrupted by a discoid
spot of the form and dimensions of an iris, which presents a median lenticular
vacuity, again revealing the pigment, obviously the vertical pupil of a nocturnal
animal. The preservation of the outline of color is certainly remarkable in a
specimen of such great antiquity. A somewhat parallel case occurs in the
preservation of the ink-bags of the Sepix; but these do not date further back
than the Jurassic. These appearances can not be explained on any supposition
of accidental production. :

SECTION II.

;CRIPTIONS OF INVERTEBRATES FROM THE CARBONIF-
EROUS SYSTEM.

By F. B. MEEK anv A. H. WORTHEN.

INVERTEBRATE FOSSILS OF TIE KINDERHOOK GROUP.

PROTOZOA.

SPONGI.
PETROSPONGIA.
Genus SPHENOPOTERIUM, M. and W.
[ogqy, a widge; norpcov, a drinking cup.]
Sphenopoterium, Munx and Worruen, Oct., 1860. Pro. Acad. Nat. Sci., Philad., p. 447.

Moke or less cuneate, or irregularly subturbinate, with a few
rounded cells or cup-like cavities, opening upwards, or in part,
somewhat laterally. Substance comparatively dense, and per-
forated by irregular pores or small canals. Walls of cells with
more or less obscure vertical striz within. External surface
marked by fine irregular, anastomosing, somewhat granular
strize.

In first proposing the above generic name for the reception of a species of
this group from the Keokuk limestone, we supposed the obscure strize seen
within the cells might be the remains of rudimentary septa, and hence regarded
it as most probably a coral. On taking up the group for more careful study at
a later date, and comparing the several known species with various groups of
corals, with the view of determining the affinities of the genus, we were unable
to find any section of corals apparently bearing even remote relations to it, and
sent specimens of the typical species to Prof. A. EH. Verrill, of Yale College,
who has devoted especial attention to the corals, with the request that he

—19 «

Bow ae
a

OS SS eee

a

146 PALEONTOLOGY OF ILLINOIS.

should give us some suggestions respecting its affinities. From as careful an
examination as could be made without preparing sections for the microscope,
Prof. Verrill writes that he thinks it most probably a sponge, and not a coral,

which view we have adopted on his authority. Prof. V. says he is not ac-

quainted with any nearly allied genus, but that it is remotely allied to some of
the Jurassic forms. :

So far as known at present, the range of this genus is from the Kinderhook ©

division of the Subcarboniferous series to the Chester limestone of the same.

SPHENOPOTERIUM ENORME, M. and W.
Pl. 14, Fig. 1a, 10.

Sphenopoterium enorme, MerK and WorTHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad. p. 448.

SMALL, sub-globose or obtusely subturbinate; irregularly
rounded and apparently retaining remains of a scar of attach-
ment at the base. Cells four or more, rounded, conical, of
moderate depth, and rather irregularly disposed. Surface
strie, rather distinct, and broken up into irregular granules.
Length or height, about 0.48 inch; greatest transverse diam-
eter, about 0.43; breadth of cells, near 0.18 inch.

Locality and position: Rockford, Indiana, Gonialite bed, of the Kinderhook
group, Subcarboniferous series. Also, in same horizon at Clarksville, Missouri.

SPHENOPOTERIUM ENORME, Var. DEPRESSUM.
Pl. 14, Fig. 2a, 20.

Tus form may possibly belong to a distinct species, but with
the specimens we have yet seen, for comparison, we are inclined
to regard it as only a variety of the last. It differs mainly in
being more depressed, and in having its base flattened, or
truncate instead of irregularly conical. Its cells are also more
regularly disposed in a quadrangle, and more nearly on a plane.

Locality and position: Salt Lick Point, Monroe county, Illinois, in same
position as last.

INVERTEBRATES. 147

RADDA: =
— ECHINODERMATA..

CRIN O1DECA

Genus ACTINOCRINUS, Miller.

Synon.—Actinocrinites, MinumR, 1821. Nat. His. Crinoidea.
Actinocrinus, AGassiz, 1835. Mem. Soc. Sci. Neuchat., 1.
Welocrinites, (sp.), Goupr., 1839. Act. Nat. Curios., XIX; (not 1826 Petref.

Germ. 1, p. 197.)
Melocrinus, (sp.), Bronn, 1848. Nom. Palxont. 1, p. 719; (not Ag. 1835.)
Abracrinus, pD’OrBIGNY, 1850. Paleont. Stratigr. 1, p. 156.
Conocrinus, Troost, 1850. List Crin. Tenn. Proc. Am. Ass., Cambridge, p. 60.
Batocrinus, Cassppay, 1854. Zeitschr. Deutsch. Geol. Gessellsch, VI, p. 237.
Eretmocrinus, Lyon and Oassmpay, 1859. Am. Jour. Sci., (2), Vol. XXVIII,
p. 241.
Alloprosallocrinus, Lyon and CassEpAy, 1860. Am. Acad. Arts and Sci., Vol.
V, p. 29.
Uperocrinus, Merk and WortHEN, Aug.,1865. Pro. Ac. Nat. Sci., Philad., p. 153.

* Generic Formula.—

Basal pieces, 3.

Subradials, 0.

Radials, 3-4-5. .

Secondary do., 0to lor 2-+10. (Sometimes 1 in 3 rays, and 2 in each of
the others. 5

Interradials, 1 to 13, or more.

Anal pieces, 3 to 15, or more; the first one resting on the base.

Opening of summit, sub-central or central—with or without a proboscis.

Arms, 12 to 30, or more.

Column, round, with a cylindrical or more or less pentagonal cavity.

Body, when divested of the arms and column, presenting
every diversity of form, from sub-globose to fusiform, conic,
sub-discoid, wheel-shaped, pyriform, etc. The three basal pieces

* are arranged so as to form a flattened hexagonal disc, or a
more or less elevated cup. Of the five first radial pieces, three

* It is very probable that at least a part of the characters generally expressed in
what are now called the generic formule of Crinoids, will be found to be rather family
characters than generic. ,

148 PALMONTOLOGY OF ILLINOIS.

are generally hexagonal, and rest upon the truncated upper
side of the basal piece, while the other two are heptagonal,
and rest upon the base so as to occupy more or less defined re-
treating angles or notches at the sutures dividing the basal
pieces. Second primy radials hexagonal, pentagonal or quad-
rancular; while the third, upon which the first bifurcation

takes place, are pentagonal, hexagonal, or heptagonal. The |

secondary radial pieces, which are sometimes, though rarely,
wanting, usually vary from one to two in each division of each
ray, and support the brachial pieces, excepting where other
divisions take place upon intervening pieces.

Anal plates varying in number in the different species; the
first being usually nearly or quite as large as the first radials,
with which it also corresponds in resting directly down upon
the basal pieces. . Interradials equally variable in number, ac-
cording to the species, and to some extent in different individ-
uals of the same species; the first is nearly always larger than
the others, and rests between the superior lateral a sides
of the first radial pieces.

Arms varying in number from twelve to thirty or more, and
with rare exceptions all simple after becoming free;—always
composed, excepting at their bases, each of a double series of

small interlocking pieces, which support tentacles along their .

inner sides.

Vault composed of variously formed pieces, sometimes in
part swelling out into more or less prominent nodes, or even
short spine-like projections, either terminating in a slender,
more or less elongated, sub-central proboscis, having the open-
ing at its summit, or with a simple sub-central opening, with-
out a proboscis.

Surface of body plates ornamented with radiating coste,
nodes or granules, or sometimes nearly or quite smooth.

As in other allied types, the visceral cavity is known to
have been (in some species at least) provided with a curious

— a roan a =

INVERTEBRATES. 149

convoluted plate, connected with the digestive apparatus. For
an illustration of this organ, as seen in the genus Strotocrinus,
see a wood cut given in another part of this volume, in conneéc-
tion with the description of that genus.

The foregoing description is drawn up so as to exclude some types usually in-

cluded in this genus, but which, we think, should be separated as distinct

enera. Even as here defined, however, it is susceptible of division into several
sections and subordinate groups, as follows:

te ACTINOCHRINUWS, Mitrre, (proper.)
a.—Groups of arm bases, forming five distinctly separated prominent lobes, some-
times including the adjacent parts, in to the third primary radial pieces ;
second primary radials nearly always hexagonal; vault provided with an
elongated sub-central proboscis, with the opening at its summit; body
plates generally ornamented with radiating goste.
Actinocrinus triacontadactylus, Minter; A. dorsatus, A. stellarisand A. armatus,

% pE Konincx ; A. Lowi, Hat; A. concinnus and A. multiradiatus, SHUMARD?

6.—Differs from the above in having the arm bases not projecting in lobes, and
much less distinctly in groups, or sometimes forming a nearly continuous
series.
A. proboscidialis, A. clarus, A. sexarmatus, A. costatus and A. multibrachiatus,
Hait; A. Hurdianus, McCursney ; A. polydactylus, Murr, etc.

c.—Agrees with the last, excepting in having the sub-central opening of the vault
simple or without a proboscis.*

Actinocrinus ornatus, A. cancellatus and A. ventricosus, Hau; A. subventricosus,

McCuHeEsney.

* We are in considerable doubt in regard to the nature and importance of the dif-
ference between species with a simple opening, near the centre of the summit, and
those provided with an elongated central or subcentral proboscis, with the opening
at its extremity. At one time we were inclined to think this a character of considerable
importance, indicating fundamental differences in the structure of the animal; but
the fact that we find this difference occurring in various genera of palzozoic crinoids,
even after being carefully restricted and grouped upon all other characters, has led us
to doubt its value as a generic distinction, and even to suspect that it might have been
in some cases a sexual difference, since the Mchinodermata are known to have the sexes
distinct. Yet the specific relations of the forms thus distinguished do not seem to
sustain this supposition; while the well-known fact that the reproductive organs in
the recent Crinoidea are not located within the body, but on the tentacles of the
arms, renders it very improbable that the presence or absence of a proboscis could
have depended upon the sexof the animal. In a few rare cases species like Actinocri-
nus oblatus, Hall, which have a very slender proboscis, seem to have had that appen-
dage sometimes accidentally broken away, during the life of the animal, so that the
fractured edges of its base become absorbed and round in such a manner as to present

150 PALEONTOLOGY OF ILLINOIS.

2. BATOCRINUS, Cassepay=(Eretmocrinus, Lyon ?)
a.—Arm bases not separated into groups or projectiug as lobes, but forming a
nearly or quite continuous series all around; body basin-shaped below the
arms and about as prominent as the vault; second primary radial pieces
almost invariably quadrangular, and: generally wider than long; body
plates often tumid, but never marked with radiating costa; proboscis well
developed.
Actinocrinus (Batocrinus) icosidactylus and A. (B.) irregularis, Cassupay ; A.
clypeatus, A. formosus, A. equalis and A. discoideus, Hawt, etc.
b,—(Alloprosallocrinus, Lyon and Cassrpay—Conocrinus, Troost.) Only differs®
from Batocrinus proper in being flat below the arm bases.
A. conicus and A. depressus, Lyon and Cassmepay; A. euconus, M. and W.
c.—(Uperocrinus, M. and W.) Differs from Batocrinus proper in haying the body
below the arms very narrow, and drawn out so as to formakind of handle
to the upper part.
Actinocrinus pyriformis, SHUMARD ; A. pistillus and A..pistilliformis, M. and W.
d.—Differs from Batocrinus proper in being sub-globose, or depressed so as to
become wheel-shaped ; also, in having its body plates less tumid or quite
even, and the base more rounded; very rarely with the interradial gpaces
emarginated, soas to give astellated outline, as seen from above or below.
Actinocrinus rotundatus, Suumarp; A. similis, A. inornatus, A. biturbinatus,
A, sinuatus and A. planodiscus, Hauu; A. Christyi, SHumMARD; A. xqui-
brachiatas and A. Hageri, McCuEsnny; and A. asteriscus, M. and W.

We are very much inclined to the opinion that the Batocrinus group should
stand as a distinct genus, but as it seems to shade into Actinocrinus proper,
through section 6 of that genus, and palceontologists have generally included it,
we have concluded to place it, for the present, as a section, under Actinocrinus.
It is worthy of note, however, that it is an American group, and is apparently
confined to the Sub-carboniferous rocks. It includes, as we have defined it, a
rather wide range of forms, some of which, like our A. asteriscus, if compared
without the intermediate links, would seem to be very distinct from the typical
species; and yet such forms shade, by easy gradations, through A. xquibrachi-
atus, McChesney, A. Christy, and various less depressed species, into A. rotun-
datus, and so on through the whole series, so that there seems to be no suffi-
ciently defined break to warrant the division of the group even into well marked
sub-genera.

The genus Actinocrinus, as we have defined it, is readily distinguished from
our Steganocrinus, by the remarkable, greatly extended, free, covered rays of

exactly the appearance of a naturally simple opening, without any traces of a probos-
cis. This we believe to be the case with the specimen of A. Hageri, figured by
McChesney. That the difference alluded to, however, could have been thus produced
in the typical Actinocrini, in Strotocrinus and various other genera, no one would for
a moment believe, after examining good species.

awe Py re

‘ae

INVERTEBRATES. | RE

that type; and from our Sérotocrinus, by the curious expansion of the summit
of the latter, formed by the numerous divisions of the rays (with their inter-
mediate pieces), between the third primary radials and the free arms. From
Amphoracrinus and Agaricocrinus, it is easily distinguished by the lateral open-

aa ing of the summit, and general physiognomy of these types. From Megisto-

’ erinus, as properly resticted, it can in most cases, be distinguished by the
position and nature of the opening of the summit, as well as by the mode of
division of the rays previous to giving off the free arms, and by differences in
the general physiognomy of the entire body. From WMacrostylocrinus, Hall,
(Cytocrinus, Roemer), it is distinguished by the having its first anal plate rest-
ing down upon the base. From WSaccocrinus, with which it agrees in the
number and arrangement of its basal, primary radial, and interradial plates, it
differs in the irregular manner of the divisions of the rays, and the disposition
of their pieces, between the third radials and the base of the free arms in that
genus. é

M. M. de Koninck and Lehon, in their valuable work on the Crinoidea of
the Carboniferous rocks of Belgium, express the opinion that the genus Actino-
erinus is confined to the Carboniferous system. In this country, however, we
have evidence of its existence as early as during the deposition of the Upper
Silurian rocks; several species are also known in our Devonian series. It was
during the Subcarboniferous epoch, however, that it attained its greatest devel-
ment, particularly while the Burlington limestone was forming. We know of
no species of the genus higher in the series than the St. Louis limestone, and
the only two species yet found in that rock, belong to the Batocrinus division.

-Supcrnus BATOCRINUS, Casseday.

Sc. c. (UPEROCRINUS, M. and W.)

ACTINOCRINUS PISTILLIFORMIS, M. and W.

Pl. 14, Fig. 8.

Actinocrinus pyriformis, var. rudis, Mnux and WortHen, June, 1861. Proceedings
Acad. Nat. Sci. Philad,, p. 131; (not A. pyriformis, Saumarp, Geol. Report Mis-
souri, p. 192, 1855; nor A. rudis, Hall, Sup. lowa Report, p. 33, 1860.)

Actinocrinus pistilliformis, M. and W., Aug., 1865. Pro. Acad. Nat. Sci. Philad., p. 153.

Bopy, exclusive of the proboscis, pyriform, being very navr-
row and apparently cylindrical from the base to the top of the

152 PALEONTOLOGY OF ILLINOIS.

third radial plates, above which the secondary radial, and
brachial pieces, curve abruptly outwards to the base of the
arms, so as to form, with the ventricose summit, a much ex-
panded visceral cavity, entirely above the basal and primary
radial plates.

Base unknown; first radials unknown, excepting from some
remaining portions of their upper ends, which show that they
are comparatively large. Second radials very small, a little
wider than long, (those seen) irregularly pentagonal in form,
one of the sides being much shorter than the others. Third

radials as long as the first, and nearly one-third wider; the —

only two visible in our specimen hexigonal in form, and each
supporting on its superior sloping sides two secondary radials
of about its own size. Hach of these is surmounted by a some-
what larger second secondary radial, which in its turn supports
two first brachial pieces, each of which is succeeded by a sec-
ond, from which the free arms are given off. The two series
of secondary radials, and the four series of brachial pieces in
each ray, coming in contact laterally, leave no room for inter-
axillary and interbrachial pieces. Interradial plates two or
three, the first being about the same size as the second radials,
and hexagonal or heptagonal in form. Above this there is one
or two small pieces of variable size and form, over which the
secondary radials, and the lateral series of brachial pieces of
the rays on each side, connect all the way up to the free arms,
in such a manner as to leave no spaces for interradials, above
those just described. (Anal plates unknown.)

Dome hemispherical, composed of pentagonal, hexagonal
and heptagonal plates of nearly uniform size, each of which is
provided with a spine-like tubercle. Proboscis central, or
nearly so. Arm openings twenty. Surface smooth or obscure-
ly graulose; small rather pointed tubercles are also seen on
the second and third radial plates, first interradials, and first
secondary radials.

co... ee

om

J

INVERTEBRATES. 153

Tn first describing this species, we regarded it as a variety of A. pyriformis,
Shumard, for which we proposed the name rudis, not being aware at that time
that Prof. Hall had used that name for another species in his Supplement to
the Iowa Report. Later comparisons, however, led us to the conclusion that it
is specifically distinct from Dr. Shumard’s A. pyriformis, and as the name A.
rudis could not be retained for it, we proposed to call it A. pistilliformis. It
differs from A. pyriformis, Shumard, in the subspiniferous character of its
plates, and in the possession of only two or three interradial plates, instead of
six in each interradial space. It also differs in having a more ventricose
dome, while the inferior half of its body is more abruptly contracted below the
arms,

Locality and position: Salt-Lick Point, Marion county, Illinois ; Kinderhook
group, of the Subcarboniferous series.

MOLLUSCA.

BRACHIOPODA.
Genus RHYNCHONELLA, Fischer, 1809.

(Mem. Soc. Imp., Moscou, ii.)
RYNCHONELLA MISSOURIENSIS, Shumard.
Pl. 14, Fig. 4a, 46.

Rhynchonella Missouriensis, SHUMARD, 1855.
204, pl. C, fig. 5a.

2d Ann. Rep. Geol. Survey Missouri, p.

SHELL subtrigonal, subglobose or moderately gibbous; late-
ral margins rounded; front somewhat truncated, or a little
sinuous in outline; postero-lateral margins converging to the
beaks at an angle of about 114°. Dorsal valve more convex
than the other, sometimes very gibbous;mesial elevation rather
obscure, rarely extending beyond the middle of the valve,
occupied by from two to three (rarely four) rounded plica-
tions, which generally become obsolete near the middle of the
valve; anterior margins on each side of the mesial ridge pro-
vided with one or two obscure plications ; beak not prominent.

Ventral valve moderately convex in the umbonal and antero-
——2 1)

meee Jha fle
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/ Ant Yiviwe Serer ra beret
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7,3 Gi AS) ~ wl ich fe.
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154 | PALMHONTOLOGY OF ILLINOIS.

lateral regions, and. depressed in the middle towards the front,
so as to form a rather broad, rounded, moderately deep sinus,
occupied by from one to three obscure rounded plications, usu-
ally not extending up to the middle of the valve; front curv-
ing down and more or less produced in the middle, in.the form
of a semicircular or subquadrate projection, fitting into a cor-
responding sinus in the margin of the other valve; antero-
lateral margins each occupied by two obscure, usually short,
rounded plications; beak short, small, and closely incurved
upon that of the other valve. Surface apparently smooth, or
having only a few subimbricating marks of growth near the
front, but showing under a lens traces of exceedingly fine,
‘ nearly obsolete, radiating strize, which are also visible on the
lamin of partly exfoliated specimens. Length (of a gibbous
specimen), 0.50 inch; breadth, 0.56 inch; convexity, 8.40 inch.

This shell varies considerably in form, and in the distinctness of its plica-
tions, some individuals being much more gibbous than others; while in some
examples (particularly young shells) the plications are almost entirely obso-
lete, and in others more distinctly defined, and extending farther up towards
the beaks. The obscure, minute, radiating strie, mentioned above, seem to be
produced by the fibrous structure of the shell, rather than by true surface mark-
ings, since they are visible on all the laminz of exfoliating specimens. On
protected portions of well preserved specimens, we have also thought we could
sometimes see traces of minute, concentric strie, by the aid of a good lens.

We are not quite sure Dr. Shumard is right in regarding figure 56 and 5c,
plate C, of the Missouri report, cited above, as a variety of this species, since
we have not seen all the intermediate gradations connecting these forms.

After a careful comparison of the shell under consideration, with a fine series
of Rhynchonella reniformis and R. pugnus, sent by Mr. Davidson, from the
Carboniferous limestone of England and Ireland, it seems to us that it will be
difficult, if not impossible, to distinguish it from certain varieties of both of
these forms, which are themselves regarded by some authors as only varieties of

one species.
Locality and position: Rockford, Indiana, in the Goniatite bed of the Kin-

derhook group, Subcarboniferous series; also at the same horizon at Chouteau
Springs, and numerous other localities in Missouri.

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2 es poetee SM i
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7.

INVERTEBRATES. “P55

Genus SPIRIFER, Sowerby, 1815.
(Mineral Coch., ii, p. 42.)
Suscenus MARTINIA, McCoy.

Martinia, McCoy, 1844. Carb. Foss. Ireland, p. 139.
Ambocelia, Haut, 1860. Thirteenth Ann. Report Regents Univ., N. Y., p. 71.

SPIRIFER COOPERENSIS, Swallow.

Pl. 14, Fig. 5a, 55.

Spirifer Cooperensis, SwAuLow, 1860. Trans. St. Louis Acad. Sci., Vol. 1, p. 643.

Spirifer semiplicata, Hauu? Dec., 1860. Thirteenth Ann. Report of the Regents Uniy.
W. ¥., p. 111.

SHELL small, transversely subelliptical, gibbous, greatest
breadth generally a little above the middle; lateral margins
rounded, converging somewhat towards the front, which is sub-
truncate or slightly sinuous in the middle; hinge considerably
shorter than the breadth of the shell, rounded at the extremi-
ties. -Dorsal valve depressed-convex, provided with a low,
scarcely defined mesial elevation, on each side of which are
two or three depressed, rounded, obscure plications, rarely
traceable to the umbo; beak nearly obsolete, or very small,
and scarcely distinct.from the cardinal margin; area small, not
incurved. Ventral valve considerably more gibbous than the
other, provided with a moderately distinct shallow mesial sinus,
which commences very narrow near the beak, and widens
rather rapidly to the front, its deepest part being along the
middle; lateral slopes on each side of the sinus, having three
or four very obscure, depressed plications, similar to those on
the other valve; beak prominent, distinctly incurved beyond

the hinge line; area small, triangular, arching back over the

hinge, moderately well defined; foramen triangular, nearly as
wide at the hinge line as on each side, apparently always open.
Surface having a few subimbricating concentric marks of

a A a a a a a

156 PALEONTOLOGY OF ILLINOIS.

erowth, and showing, under a magnifier, indistinct granula-
tions. Some specimens have faint indications of two plica-
tions within the ventral sinus. Length, 0.38 inch; breadth,
0.35 inch; convexity, 0.26 inch. :

As remarked by Prof. Swallow, this species resembles S. dineatus, Martin
(sp.), but differs materially in the possession of obscure radiating plications,
and in being more distinctly inequivalve. Young specimens also resemble
somewhat S. Ure’, Fleming,* but they may always be readily distinguished
from that shell by their plications.

Locality and position: Same as last.

LAMELLIBRANCHIATA.
Grnus CARDIOPSIS, M. and W.

Cardiopsis, Munk and WortueEn, June, 1861. Proceed. Acad. Nat. Sci., Philad., p. 144.

SHELL equivalve, somewhat inequilateral, very slightly ob-
lique, ovate or cordiform, entirely closed; beaks rather eleva-
ted, distinctly incurved and directed towards the anterior side;
surface marked by radiating strie or coste; cardinal margin
short and rounding into the posterior border; hinge provided
with one or two distinct anterior teeth in each valve, near the
beaks. (Ligament and muscular impressions unknown.)

_In first describing the species we regard as the type of this genus, we placed
it provisionally in the genus Cardiomorpha, de Koninck, stating at the same
time that we suspected it to be generically distinct. Prof. Hall has since de-
scribed the same species, from the same locality, in the Thirteenth Annual
Report of the Regents of the University of New York, under the name of
Megambonia Lyoni,t and mentions the presence of two strong anterior teeth in
the hinge of one valve. On clearing away the matrix from the hinge of one

* Mr. Thomas Dayidson, of London, after a careful comparison of specimens from
Illinois, states that he regards Ambocelia gemmula of McChesney, (which had been pre-
viously described by Dr. Shumard, in the Missouri Report, under the name of Spirifer
planoconveaus), as identical with Spirifer Urei of Fleming.

+ The genus Megambonia was founded upon Pterinea cardiiformis, Hall, belonging
apparently to the Arcidx or Aviculide.

INVERTEBRATES. aso

of our specimens, we have been able to see traces of the impressions of these
teeth, the presence of which establishes, we think, the correctness of our sug-
gestion that it does not properly belong to the genus Cardiomorpha. :
It is not improbable that some of the species ranged by Prof. de Koninck in his
genus—when all their characters can be made out—may be found congeneric
with our shell; though it is manifest those he considered the typical species
are not, since he distinctly states that the hinge is without teeth, and provided °
with a smooth lamina from the beaks to the posterior extremity, as some of his
figures show. In addition to this, all the species described by him, (with one
single exception, which is a transverse shell, and apparently a wide departure
from his typical species, as well as from ours,) are merely marked by concentric
strie, and show no traces of the regular radiating costze seen on our shell.

CARDIOPSIS RADIATA, M. and W.

Pl. 14, Figs. 6a, 66.
Cardiomorpha radiata, Manx and WortneEn, Oct., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 448. (Not C. radiata, pp Konincx, 1844. An. Foss., p. 109.)
Megambonia Lyoni, Haut, Dec., 1860. Report Regents University, New York, p. 110.

SHELL sub-circular, gibbous in the central and umbonal re-
gions, a little higher than wide, slightly oblique; basal border
more narrowly rounded than the front and anal margins; hinge
border short, apparently a little arched; beaks gibbous, rising
somewhat above the hinge, abruptly pointed, incurved, and
showing a tendency to curve forward at the immediate points;
surface ornamented by numerous fine, regular, rather rounded
radiating strize, some seven or eight of which may be counted
in the space of 0.20 inch, at the middle of the base. Height,
about 1.05 inch; length, 0.95 inch ; breadth or convexity, near
0.76 inch.

This species is more like Cardiomorpha ovata, Hall, (Iowa Report, p. 522, pl.
7, fig. 10*), from the same horizon (now made the type of a new genus Dexio-
bia, by Prof. Winchell), than any other shell’with which we are acquainted,

but is more nearly circular in form, has more depressed beaks, and much coarser
and more distinct striee, while its umbonal slopes are less prominent.

* Not C. ovata, d’Orbigny.

158 PALEONTOLOGY -OF ILLINOIS.

Locality and position: Rockford, Indiana, in the Gonaitite bed of the Kin-
derhook group; also, in the same horizon at Grafton, Jersey county, Illinois.
Subcarboniferous. ;

GASTEROPODA.
Gunus STRAPAROLLUS, Montfort, 1810.

(Conch. Syst., ii, p. 174.)

Ir we could rely upon the accuracy of Montfort’s figure and description of
the type of his genus Straparollus (S. Dionysi’), little doubt could be enter-
‘tained in regard to its being entirely distinct from Huomphalus, Sowerby, as
represented by Sowerby’s typical species L. pentangulatus, H. catillus, and L.
nodosus. As Prof. de Koninck, however, after enjoying the advantage of study-
ing collections from Montfort’s original locality (Namur), gives figures of S.
Dionysti, Montfort (Foss. An. Belg., pl. xxiv.), showing the form of the aper-
ture, and the nature of the lower part of the lip to be quite different from
what we see in Montfort’s figure, and more nearly as in the types of Euompha-
lus, we are probably warranted in adopting the conclusion that these forms are
congeneric, and that Montfort’s figures are, as usual, defective. Still, after ad-
mitting the correctness of Prof. de Koninck’s identification, and the accuracy of
his figures, we can but regard the original types of Huomphalus, with their
greatly depressed or nearly planorbicular form, and angular whorls, almost
equally visible on either side, as at least subgenerically distinct from the type
of Straparollus, with its rounded or non-angulated whorls, smaller umbilicus,
. and more prominent spire. Hence we think the name Huomphalus should be
retained, in a subgeneric sense, under Straparollus, for the group of which Z.
pentangulatus, of Sowerby, is the type.

We are aware Prof. McCoy, and some others, regard Huomphalus as typified
by LE. pentangulatus, as an exact synonym of Straparollus, and that he proposes
to transfer the former name to another group, consisting of rough, Cirrus-like
shells, of which L. discoris and £. rugosus, Sowerby, are examples. (See
Brit. Pal. Foss., p. 279). Jt seems to us, however, that if the name Huompha-
lus is to be retained at all, we should apply it to the forms for which it was
originally proposed, and that we have no right to transfer it to another type,
because Sowerby subsequently, in another place, refers this other type to his
genus Huomphalus. If we regard Straporollus, Montfort, 1810, and Huompha-
lus, Sowerby, 1815, as exactly synonymous, then the latter name should be
dropped from use, except in the synonymy of Straparollus, and could not,
according to the most generally accepted rules of nomenclature, be transferred

’

4
‘

INVERTEBRATES. 159

to the Z. discoris group, whether we view these shells as constituting a section
of the genus Straparollus, or as an entirely distinct genus.

A marked subgenus, apparently of this group, from the Carboniferous rocks
of California, was described by one of the writers (I. B. M.) under the name
Omphalotrochus, in volume 1 of the Paleontology of that State, p. 15, and fig-
ured on pl. 2, fig. 8,8a, of the same report. It isa large, very ponderous
shell, having much the form of a depressed Pleurotomaria, with a deep, conical
umbilicus, and whorls flattened and biangular around the outer side. Another
species of the same type was described by d’ Orbigny, from the Carboniferous
rocks of Bolivia, under the name Solariwm antiquum. (See Voyages dans
UAmerique Merid., p. 42, pl. 3, figs. 1, 3.)

STRAPAROLLUS LENS, Hall, (sp). -

Pl. 14, Fig. 7a, 76.
Huomphatus lens, Haut, Dec., 1860. Thirteenth Ann. Rept. Regents Univ. N.Y., p.109.

SHELL rather under medium size, lenticular; spire much de-
pressed, or rising little above the body whorl; volutions about
four, increasing moderately in size, nearly flat, with an out-
ward slope above—the slope being about coincident with that
of the spire—last one angular around the periphery, and
rather distinctly convex and rounded below; suture (in casts
at least) well defined; umbilicus deep, less than the breadth
of the outer whorl at the aperture. Surface unknown. Aper-
ture transversely subovate, or subrhombic in outline. Height
of one of the largest specimens, 0.35 inch; greatest breadth,
0.60 inch; height of aperture, 0.19 inch; breadth of aperture,
0.25 inch.

‘The only specimens of this species we have seen not being in a condition to
show the nature of the lip, or the surface lines of growth, it is difficult to de-
termine, very satisfactorily, its generic relations. It has the form of some of
the lenticular species of Pleurotomaria, but there are no evidences manifest, in
any of the specimens we have examined, of a spiral band, as in that genus;
hence it seems to belong toa paleeozoic group of lenticular forms, usually refer-
red to Huomphalus, as that name is generally used in its widest signification.
It is not a typical Huamphalus, however, and if falling within the genus Strap-

160 . PALEONTOLOGY OF ILLINOIS.

allous, should be regarded as belonging to a distinct section from the type of
that genus. F

Locality and position: Same as last. Also in the Chouteau limestone of
Moniteau and other adjoining counties of Missouri, and in the same position
in this State.

Genus BELLEROPHON, Montfort, 1810.
(Conch. Syst., ii, p. 174.)
BELLEROPHON CYRTOLITES, Hall.

Pl. 14, Fig. 8a, 80.

Bellerophon cyrtolites, Hat, Dec., 1860. Thirteenth Ann. Report Regents University

IM YES 195 LOYo ; '

SHELL small, sub-lenticular ; sides converging with a slightly
convex outline, from near the umbilicus to the prominent
angular periphery; volutions apparently about two and a half,
increasing rather rapidly in size, each of those within, about
three-fourths embraced by the suceeeding turn, last one becom-
ing obtusely angular around the umbilicus; aperture cordate;
lips broadly and deeply sinuous at the dorsal angle; umbilicus
(in casts) about one-third the breadth of the outer whorl, deep
and conical; surface of casts retaining obscure traces of marks
of growth, which in crossing the sides of the whorls from the
umbilicus, make a graceful curve forward, and in approaching
the dorsal angle, curve very strongly backwards, so as to indi-
cate the presence of a very profound but not sharply defined
sinus, in the lip. Greater diameter of a large specimen, 0.66
inch; breadth at the aperture, 0.35 inch.

This species belongs to a section of lenticular species, for which one of the
writers has proposed the name Zropidodiscus,* with B. curvilineatus, of Conrad,
as its type. These shells differ from the type of the genus Bellerophon (B.
vasulites), Montfort, in their lenticular form, often carinated dorsum without a

* Proceed. Chicago Acad. Sci., Vol. 1, p. 9, March, 1866.

INVERTEBRATES. 161

defined band, open umbilicus, and in not having the inner lip callous and spread
over the inner whorls. They seem also to have been thinner shells than the
typical Bellerophons, and may belong to an entirely distinct genus. --

Specifically, the form under consideration seems to approach B. Deslon-
champsti, V Orbigny, from the Upper Silurian, (referred by that author to Oyrto-
lites, of Conrad), but has its dorsum more angular, and its aperture narrower,
than d’Orbigny’s species.

Locality and position: Rockford, Indiana; in the Goniatite bed of the Kin-
derhook group. Subcarboniferous.

CEPHALOPODA.
Genus NAUTILUS, Linnzeus, 1758.

(Syst. Nat. Ed., 10, t.1I, p. 709.)
Suscgenus TREMATODISCUS, M. and W.

Trematodiscus, Muzx and WorTHEN, 1861. Proceed. Acad. Nat. Sci., Philad., p. 147.

WE proposed to range under the above subgeneric name, a peculiar group
of Nautili, which differ so materially from the living typical species of Nautilus,
that few Conchologists would place them even in the same genus, if they were
found inhabiting our present seas. These shells are characterized by a discoid
form, and a wide, shallow umbilicus, usually, if not always, perforated in the
middle, and showing all the inner turns. Their whorls are slender, very
slightly embracing or merely in contact, and provided with revolving angles
and grooves; while the surface is frequently ornamented with distinct revoly-
ing strie. The siphuncle is central, or located between the middle and the
dorsal side, though never quite marginal.

In first publishing descriptions of some of the forms included in this sub-
genus, we proposed to retain for it Prof. King’s abandoned name, Discus. As
this name had, however, been previously used by Fitzinger in 1833, for a
group of Helicidz, and by Prof. Haldeman in 1840, for a group of Limnzxidz,

it became necessary to introduce a new name for the forms under considera-

tion.

Although in some respects analagous to Discites, of McCoy, these shells differ
from the typical forms of that group in having a perforated umbilicus; while
the whorls are less compressed, narrower, and provided with several distinct
revolving angles and grooves. They also differ in being often ornamented with
well defined revolving lines.

162 PALEONTOLOGY OF ILLINOIS.

In the perforated character of the umbilicus, the shells of this group may
not differ from some other sections of discoid fossil Nautili, but in the posses-
sion of several distinct revolving grooves and angles, with strong longitudinal
striz, they seem to be quite peculiar. The group appears to be mainly, if not
almost exclusively confined to the Carboniferous system, and will include the
following foreign species: Nautilus stygialis, N. Edwardsianus, N. Omalianus
and WV. pinguis,* de Koninck, together with JV. sulcatus, N. cariniferus, etc.,
of Sowerby. i

After proposing the foregoing name and description for this ancient group of
Nautili, we observed that Prof. McCoy had proposed in his “Carboniferous
Fossils of Ireland,” p. 20, 1844, the name Temnochielus, for a group of Carbon-
iferous species, including some of the same species for which our name Zrema-
todiscus was proposed. As his subgenus, however, embraced a much wider
diversity of forms than ours, it may be found convenient to restrict it to such
types as his first species WV. biangulatus, N. pinguis (McCoy, not de Kon.),
and JV. globatus, as proposed by one of the writers (Palzeont. Up. Mo., p. 64),
during the past year; while Zrematodiscus may be retained for the forms agree-
ing with the types for which it was proposed.

As noticed in the Paleent. Up. Mo., above cited, Blainville had in 1824
(Dect. Sc. Nat. Tom. XXXII, p. 185), included some of the same forms fall-
ing within the group Zrematodiscus, in Montfort’s proposed genus Simplegades,
but it is evident from Montfort’s figure and description, that his type of Sim-
plegades, was an Ammonite or a Ceratite, and hence his name could not prop-
erly be retained for the forms under consideration.

G. B. Sowerby (Conch. Man., 276, 1842) also falls into the same error, and
places Nautilus sulcatus, Sowerby, under Montfort’s name Simplegas, or Sim-

plegades, and yet admits that Montfort’s type has sinuous septa like the Ammo-
nites.

NAvTILUS (TREMATODISCUS) TRISULCATUS, M. and W.

Pl. 14, Fig. 10a, 106, 10¢.
Nautilus (Discus) trisulcatus, Mpux and WortueEn, Oct., 1860. Proc. Acad. Nat. Sci.,
Philad., p. 470. ,
Nautilus (Trematodiscus) trisulcatus, M. and W., June, 1861. Ib., p. 148.

SHELL under medium size, discoidal; umbilicus wide, of
moderate depth, and showing nearly all of each inner whorl,

* Not VV. pinguis, McCoy.

INVERTEBRATES. 163

volutions slender, increasing very gradually in size, a little
broader transversely than the diameter from the dorsum to
the ventral margin, somewhat ventricose and rounded on
each side, and provided with a deep rounded sulcus along
each dorso-lateral margin. Between these two sulci the
dorsum is narrow, prominent, and less deeply concave, the
sulcus being bounded on each side by an angle. Sur-
face retaining traces of rather strong, regular, longitudinal
lines. Septa deeply concave, moderately close—their margins
arching distinctly backwards in each of the dorsal depressions.
Siphuncle rather small, and placed a little nearer the dorsal
than the ventral side. Greatest diameter of a specimen retain-
ing about one-third of the outer chamber, 2.23 inches; breadth
of last whorl, about 0.87 inch.

This species bears'some resemblance to certain varieties of NV. sulcatus, of
Sowerby, as figured by deKoninck (An. Foss., pl. XLVII, fig. 10, and pl.
XLVIII, figs. 8 and 9), but differs in the number and arrangement of its re-
volving angles, and in the possession of longitudinal striz. It is still more
nearly allied to NV. Kdwardsianus, de Koninck (Sup. An. Foss., pl. LIX,
fig. 7a, b, c,), but differs in having less compressed whorls, which are rounded
instead of angular around the umbilicus; while its dorsal carinez are less promi-
nent. Our specimen being merely a cast, we have no means of determining
how near these two forms may have agreed in the details of their surface
markings.

Locality and position: Rockford, Indiana, in the Goniatite bed of the Kin-
derhook Group, Subcarboniferous series.

NAvtILus pigonus, M. and W.

Pl. 14, Fig. 9a, 96, 9e, 9d.
Nautilus (Diseus) digonus, Mexx and Worrumn, Oct., 1860. Proc. Acad. Nat. Sci.,
Philad., p. 470.
SHELL small, subdiscoidal; umbilicus comparatively large,
showing all of each inner whorl, apparently perforate; volu-
tions slender, increasing very gradually in size, a little broader

.

164 PALAONTOLOGY OF ILLINOIS.

transversely than the diameter from the dorsum to the ventral
margin, nearly flat, and provided with two shallow longitudi-
nal grooves on the dorsal side, and distinctly angular around
each dorso-lateral margin, thence rounding regularly into the
umbilicus. Surface of cast retaining traces of regular, equidis- .
tant, longitudinal lines, and much finer closely arranged trans-
verse striz. Aperture and section of the whorls nearly semi-
circular, the outer or dorsal side being almost straight, and the
inner rounded. Septa distinctly concave on the side next the
aperture; their margins curving abruptly forward in crossing
the dorso-lateral angles, thence deflected backwards in the
dorsal grooves, and passing nearly straight across the middle
of the dorsum. Siphuncle small, located about one-third the
diameter of each septum from the dorsal side. Length, or
greatest diameter of a specimen, about one-third of the outer
whorl of which is non-septate, 1.25 inches; height, 1 inch;
breadth across the outer whorl, near the aperture, 0.62 inch;
diameter of same from the dorsal to the ventral side, 0.40 inch.

Prof. Hall figures in the Thirteenth Ann. Report Regents University N. Y.,
p- 105, under the name of Gyroceras gracile, a fragment of a shell apparently
related to this species. As he does not say, however, in his brief description,
whether it has rounded or angular whorls, and his figure is merely an outline
wood cut, we are Icft in some little doubt whether it may not be a fragment of
a variety of the species before us, especially as it came from the same locality
and position, and appears to agree in its surface markings. The measurements
of its proportional vertical and transverse diameters, however, would seem to
indicate narrower whorls and a more compressed form than in our shell, while
his figure represents the undulations of the septa in crossing the dorsum as dif-
fering somewhat from those of our species. If they should prove to be identi-
cal, however, our name will have to take precedence, since our description was
published more than a month in advance of Prof. Hall’s. Even if specifically
distinct, we have little doubt in regard to the shell described by Prof. Hall be-
longing to the same group as ours.

Locality and position: Rockford, Indiana, in the Goniatite bed of the Kin-

derhook Group. Subcarboniferous. Also, at the same horizon in Jersey
county, Illinois, and at several places in Central Missouri.

INVERTEBRATES. 165

Genus GONIATITES, de Haan.

Goniatites, DEHAAN, 1825. Monogr. Ammonites et Goniatites.

Aganides [2], Montrort, 1808. Conch. Syst., I, p. 30.

Ireit could be demonstrated that Groniatites, de Haan, is synonymous with
Aganides, of Montfort, as is believed by some eminent Palceontologists, we
would be compelled by the law of priority to adopt Montfort’s name for the
genus. The locality cited by Montfort (Namur, Belgium), would certainly
favor the conclusion that his type was a Goniatite; but as neither his figure,
nor his description, enables us to decide beyond doubt, whether it was a Gonia-
tite, or, as Hermannsen and others maintain, an Aturia, we do not feel warrant-
‘ed at present in adopting his name for the Goniatite group. Indeed his figure
shows apparently some faint indications of a nearly central siphuncle. If this
is not merely an accident of shading, and was really intended to indicate the posi-
tion of the siphuncle, it would settle the question that it was at least not a Gon-
iatite, and that Montfort must have been mistaken in regard to the locality from
which his type was obtained. Until this question can be more definitely settled,
we prefer to retain de Haan’s name Goniatites for this genus.

GontatitEs Tyont, M. and W.

Pl. 14, figs. lla, 110, lle.

Goniatites Lyoni, Merk and WorTHEN, Oct., 1860. Proc, Acad. Nat. Sci. Philad., p. 471.
Goniatites hyas, Hatt, Dec., 1860. Thirteenth Ann. Rept. Regents Univ. N. Y., p. 102.

SHELL compressed, discoidal; umbilicus large or nearly twice
the breadth of the outer whorl from the dorsal to the ventral
side, shallow and showing about four-fifths of each inner whorl.
Volutions slender and increasing very gradually in size, com-
pressed or ebout one-third deeper from the dorsal to the ventral
side than the transverse diameter; rather narrowly rounded on
the dorsum, and provided with a shallow concavity along the
inner side for the reception of each succeeding inner whorl.
Septa moderately distinct, and deeply divided into six* lobes
and six saddles; dorsal lobe longer than wide, infundibuliform

* The sixth lobe is at the middle of the ventral side, and not visible externally.

166 PALEONTOLOGY OF ILLINOIS.

and acutely pointed; dorsal saddle as long as the dorsal lobe,
but wider and rounded at the extremity; superior lateral lobe
lanceolate, a little longer than the dorsal lobe, acutely pointed
at the end and somewhat contracted above; lateral saddle lin-
guiform, longer and narrower than the dorsal saddle; inferior
lateral lobe similar to the superior, excepting that it is some-
what smaller; ventral saddle shorter and broader than the
lateral saddle, slightly oblique, and rounded at the end.

As remarked by Prof. Hall, this species ,bears some remote relations to
Goniatites chemungensis of Vanuxem (Report 3d Geol. Dist. N. Y., p. 182),
but differs very materially in the number of its lobes, there being five or six
visible in each septum on each side of Vanuxem’s species, and only two in ours.
It is much more nearly like G. mixolobus, Phillips, as figured in his Palzeozoiec
Fossils, pl. LI, fig. 2356, and Geol. Yorks., part II, pl. XX, fig. 43-47; but
presents well defined differences in its septa, particularly in the dorsal lobe.
Phillips’s species is said to occur both in the Carboniferous and Devonian rocks
of England.

As our. description of the species under consideration was printed and dis-
tributed more than a month in advance of the publication of Prof. Hall’s figures
and description, our name will have to take precedence, in accordance with the
established usages of naturalists.

Should it ever be demonstrated that Montfort’s type of Aganides was a true
Goniatite, the name of the species here described will of course become Agan-
ides Lyont, since Montfort’s name has priority of date.

Locality and position: Rockford, Indiana, from the Goniatite bed of the
Kinderhook group. Subcarboniferous.

=

INVERTEBRATE FOSSILS OF THE BURLINGTON GROUP.

RADIATA.

ECHINODERMATA.
CRINOIDEA.
. Genus DICHOCRINUS, Miller.

Synon.— Platycrinus (var.), Minurr, 1821. Nat. Hist. Crinoidea, 114; (not ib. p. 74.)
Platycrinus (sp.), Puwurs, 1836. Geol. Yorks., Il; Austin (sp.), 1843,
Monogr. Crinoidea.

Dichocrinus, Munster, 1838. Bietrag. Z. Petref., 1.

2 Cotyledonocrinus, CAsszDay and Lyon, 1859. Am. Acad. Arts and Sci., vol.
iv, p. 26.

The generic formula of this group, given by M. M. de Koninck and Lehon,
in their valuable ‘“ Recherches sur les Crinoides du Terrain Carbonifere de Bel-
geque,” p. 146, is as follows:

Basal pieces, 2.

Radial pieces, 4, one of which is large, +-5.
Interradial pieces unknown.

Anal pieces, 1 known, very large, resting on the base.
Number of arms, 10.

Since this formula was published, a number of species have been described
in this country, some of which seem to show that it should be slightly modi-
fied, probably as follows:

Basal pieces, 2.

Radial pieces, 2 to 42.5; the first always much larger than the others.
Interradial pieces, 4 to 5.

Anal pieces, 1 to 5; one large and resting on the base.
Arms, 10, bifurcating,

ot

» Ja ass

168 PALEONTOLOGY OF ILLINOIS.

From what is now known, this genus may be described as
follows: Basal pieces two, hexagonal, and forming when uni-
ted, an obconic or more or less depressed cup. The five first
radial pieces very large, resting directly upon the base, two
upon each basal piece, and the anterior one in a notch at one
end of the suture between the latter. Succeeding radial pieces
one to three in each ray,* very small, the last supporting the
arms, which in the typical forms of the genus, are slender and
more or less frequently bifurcating. First anal piece nearly
or quite as large as the first radial, and resting upon the base
between them, in a notch at one end of the suture between the
basals; the remaining anals small, and not very distinct from
the vault pieces. Interradials four or five, very small, and
similar to the vault pieces, resting in small notches at the
superior lateral angles of the first radials.

"The vault of D. pocillum, Hall, is described as consisting of few plates; one
between the bases of each two of the arms being larger than the others, while
on the anal side, it has numerous small plates with a minute opening, and the
whole crowned by a single, much larger plate than any of the others. Several
of the species described by Casseday and Lyon, seem to have a similar vault.

Austin’s figurs of D. elongatus, would appear to have the vault terminated
by a moderately produced proboscis, with a rounded entire extremity; but as
he says some of his specimens (including the one-from which the figure alluded
to was drawn) have but five pieces in the next range about the base, it is pro-
bable the one figured with a proboscis is a true Platycrinus.

In the simplicity of the structure of its body, this genus resembles Platy-
crinus and Hexacrinus, but is readily distinguished from both by its bipartite
base. It is more nearly allied, however, to Pterotocrinus, of Lyon, with which
it agrees in the number of its basal pieces, and in having the five first radial,
and the first anal pieces resting directly upon the base. It differs, however,
widely in the structure of the parts above, particularly in not possessing the
greatly developed interbrachial appendages of Pterotocrinus, and in haying the

* Mr. Lyon has suggested that there may be some error in Austin’s figures repre-
senting four primary radials, in their D. fusiformis, which is certainly very probable,
since none of the other species are known to have more than three of these pieces to
each ray; and as but one species is supposed to have only two, it is highly probable
that the normal number is three.

ey

INVERTEBRATES. 169

radial pieces above the first one always well developed. The general form of
the entire body in these two genera, is likewise very different.

The proposed genus Cotyledonocrinus, Cassedy and Lyon, appears to agree
exactly in all respects with Dichocrinus, excepting that it has no anal piece on
a range with the five first radials, and in contact with the base. This feature,
however, as suggested by Dr. Shumard, is proba®ly abnormal. If not, it may
be a good generic distinction.

So far as known, the genus Dichocrinus was peculiar to the Carboniferous

epoch.
x

Dicuocrinus conus, M. and W.

Pl. 16, Fig. 5a, 50.

Dichocrinus conus, Mux and Wortumn, Sept.,1860. Proc. Acad. Nat. Sci., Phil., p.381.

Bopy large, abconical, longer than wide, composed of rather
thin smooth plates, connected by close fitting linear sutures.
Base comparatively large, a little wider than high, tapering
rather rapidly to the small inferior extremity, which is trun-
cated, and provided with a small, shghtly projecting rim; both
pieces presenting a subtrigonal general outline, though really
hexagonal, if we count the slightly salient angles between the
shallow sinuosities in the upper margins; columnar facet small,
round, or a little oval. Radial pieces large, longer than wide,
presenting an oblong outline, slightly wider above than at the
base; all more or less convex on the inferior margin, which in
the anterior ray is provided with an obtuse mesial angle; sinus
in the upper edge of each, for the reception of the succeeding
range of plates, near one-third as wide as the superior margin,
_ and excavated down about one-fifth the length of the plate, its
lower edge projecting rather distinctly outwards. First anal
plate as large as the first radials, and having much the same
form, excepting that it is provided with a distinct mesial angle
above, as well as below.

Hach first radial, as well as the first anal plate, has an ob-

scure, rounded prominence, extending down the middle to its
—22

170 PALAONTOLOGY OF ILLINOIS.

base, so as to give the body a slightly hexagonal outline as
seen from below. ‘These prominences are also continued on
down upon the basal pieces, gradually becoming obsolete as
they converge towards the narrow lower extremity. Length,
to the summit of the first radial pieces, 1.28 inch; breadth,
about 1.16 inch; height of base, 0.58 inch; breadth of do.,
0.76 inch.

This species is so nearly like Dichocrinus lxvus, Hall (Sup. Geol. Report,
Towa, part 2, p 83), that we were at one time inclined to think it might be-
long to the same species. A more careful comparison, however, with the origi-
nal specimen from which Prof. Hall’s description and diagram were made out,
leads us to regard it as distinct. In the first place, the specimen under con-
sideration is much larger than that described by Prof. Hall, and differs in
having the second radials more deeply inserted into the upper margins of the
first. It likewise differs in the possession of obtuse ridge-like prominences
down the middle of the first radial and first anal plates. Again, its first anal
plate terminates in a mesial angle above, instead of being truncated, and a lit-
tle excavated in the middle.

It is perhaps more nearly allied to D. intermedius, de Koninck and Lehon
(Crinoides Ter. Carb. Belg., p. 150), though it differs in having deeper and
narrower sinuses in the upper margins of the first radials. It also differs in
having the upper extremities of the first radials and first anal plate more
incurved, and in the possession of an obtuse mesial prominence on each of
these plates. .

Locality and position: Burlington, Iowa, Burlington Limestone, of Lower
Carboniferous series.

Genus PLATYCRINUS, Miller.

Synon.—Astropodium (sp.), URE, 1793. Hist. Rutherglen, p.326; (not Defrance, 1819.)
Nave Encrinite, Parxinson, 1811. Organic Remains, II, p. 223.
Platycrinites, Mruurr, 1821. Nat. Hist. Crinoidea; Schlot., 1823, Nachtr. Zur

Petrefakt. Th., 1, 1822, and others.
Platycrinus, AGAssiz,1834. Mem. Soc. Sci. Nat. Neuch., 1, p. 197, and others.
2 Marsupiocrinites, Puinuirs, 1839. Murch. Sil. Syst., p. 672.
Centrocrinus, AUSTIN, 1843. Mongr. Recent and Foss. Crinoidea, p. 6.
Pleurocrinus, Austin, 1843. Ib. :
Ldwardsocrinus, D’OrBigny, 1850. Prodr. Paleont. Strat. 1, p. 157.
2 Cupellxocrinus, (TRoosT), SHUMARD, 1865. Cat. Paleozoic Foss., part 1, Ech.,
p. 361.

“INVERTEBRATES. . 171

1 The following is the formula of this genus, as given by de Koninck and
7 Lehon, in their “‘Recherches Sur les Orinoides Carb. de la Belgique :”

‘Basal pieces, 3, forming an expanded cup.
Radials, 2°. (one of which is large, and one small) +5.
Anals, 1 large, or 3 small.
Interradials, 1-4.
Number of arms, 10, 20, 30 or 35, according to the species.’’

CoLumN generally round near the body, more or less com-
pressed, and often tortuous below. Base pentagonal, depressed,
basin-shaped, or nearly flat, composed of one small quadrangu- =
lar piece and two larger pentagonal pieces, all of which are
generally anchylosed. First primary radials large, and resting
on the base; second primary radial pieces small, trigonal or
pentagonal, and occupying a depression in the upper margin of
each first radial—usually supporting on their sloping sides the
first divisions of the arms.

Arms ascending, or often, at first, extending nearly or quite
horizontally from the body, and bifurcating more or less fre-
quently, according to the species; all the divisions being pro-
vided with tentacles.

Dome composed of numerous irregular pieces, usually tuber-
cular, or sometimes forming spines; ventricose, more or less
depressed, or often produced in the form of an extended cylin-
drical proboscis. Opening lateral, or nearly central.

As first proposed by Miller, this genus was badly defined, and it is manifest
that its author himself had no very clear ideas of its limits, since he also in-
cluded in it species of Pentremites, Say, Dichocrinus, Munster, and of his own
genus Actinocrinus. Later writers, however, have restricted it within far more

natural limits, and, as now generally understood, Miller’s first species, P. levis,
seems to be regarded as the typical form of the genus. In this and the closely

* It is worthy of note that although de Koninck and Lehon give two radials (one large
and one small) as the number, that their Fig. 1, Pl. VI, of P. levis, Miller, shows
clearly 3 radials, one large and two small. As others figure and describe it as having -
only two, this may be only an abnormal variety. It will be seen, however, that our
P. parvulus, described on page 163 of Proceed. Acad. N. S., Philad., Aug., 1861, also
has three prjmary radials to each ray, while the arms are composéd each of a single
series of pieces. :

172 PALAONTOLOGY OF ILLINOIS.

allied species, the body is more or less hemispherical below the arms, while the

dome terminates above in a long, generally stout, central or subcentral probos-

cis, closed at the summit, but apparently pierced by a small aperture on one
side, near the upper extremity. In these typical forms the arms bifurcate

once, or oftener, near the body, beyond which they are simple, and composed — a
at first of a single series of wedge-shape pieces, passing more or less gradually
into a double series of small interlocking pieces, supporting numerous tentacles.
_ Other species, however, generally included in the genus, have no proboscis, but —

a simple aperture in the summit, located either laterally or nearly centrally ;
while some of these have the arms composed of a double series of interlocking
pieces, and others of a single series of wedge-shaped pieces,* neither of these
peculiarities in the structure of the arms being always especially coincident
with apparently any one of the other characters mentioned.

From the foregoing remarks it will be seen that the group, including species
agreeing with the given formula, may be divided, as (in part) suggested by
the Messrs. Austin, into the following four sections : +
1. PLATYCRINUWS, (typical.)

With the summit terminating in a more or less elongated, central or subcentral
proboscis, bearing the opening on one side, near the upper extremity.

Type. WP. lxvis; Miller; also includes P. spinosus and P. 30-dactylus, Austin ;
P. Mullerianus, de Koninck, and P. granulatus, Miller.

2. CENTROCRINUS, Austin.
Opening of summit nearly or quite central, but not elevated upon a proboscis.
Type. WP. [ Centrocr.| gigas, Gilbertson.

3. PLEUROCKHRINUS, Avsrin.

Differs from Centrocrinus mainly in having the opening of the summit lateral,
and nearly or quite on a line with the arm bases.

Examples: P. [Plewrocr.] mucronatus, Austin; P. [Plewrocr.| tuberculatus, Mil-
ler; P. [Pleurocr.] tuberosus, and P. [Pleurocr.| subspinosus, Hall; P. (Pleu-
rocr.) asper, Meek and Worthen, etc., etc.

4. MARSUPIOCRINITES, Paxtirs,
a—Differs from Platycrinus proper only in having its second radial pieces merely
rudimentary, or so small as te allow the first brachials to rest partly upon
the first radials.

Type. WM. celatus, Phillips.

b.—(Cupellzocrinus, Troost,) Differs fromthe last only in having a subcentral

opening without a proboscis.

Type. 2. Tennesseensis, Roemer.

* P. nodobrachiatus, Hall, Iowa Report, p. 542, 1858 (not P. nodobrachiatus, Hall,
1861;=P. perasper, M. and W., 1865), is an American example of this genus, with a
single series of pieces in each arm. It is worthy of note, that the type of Hdwardso-
crinus, d’Orbigny, has arms composed each of a single series of pieces, though it was
not upon this character, but upon the erroneous supposition that it had five basal
pieces, that he proposed to separate it from Platycrinus. ‘j

+ Monogr. Recent and Fossil Crinoidea, p. 6.

—s

INVERTEBRATES. 173

In regard to the value and importance of the characters distinguishing these

sections, Palzontologists will probably always differ. Hitherto these differ-

ences have scarcely been noticed, even by the most respectable authorities,
excepting as one of the means of distinguishing species. From all analogy,
however, it seems reasonable to suppose that they were accompanied by corres-

_ ponding modifications in the structure of the softer parts of the animal. It

will also be observed that they correspond, in part, almost exactly to the char-

acters distinguishing divisions of the allied Actinocrinus group. For instance,
the species embraced in the section Plewrocrinus differ from the typical forms
of Platycrinus, almost precisely as Agaricocrinus and Amphoracrinus do from
the typical species of Actinocrinus.

. The genus Platycrinus seems to have been introduced during the Upper
Silurian Epoch, though these earlier species generally depart more or less from
the typical Carboniferous forms, as we sce in the type of the subgenus Cupel-
lzocrinus, for instanee, and P. pluwmosus, Hall. The Devonian species hitherto
referred to this genus, are said by de Koninck to all belong to the allied genus
Hexacrinus. This group certainly uttained its maximum development during

4 the Carboniferous Epoch, which it seems not to have survived.

Suscenus PLEUROCRINUS, Austin.

PLATYCRINUS SUBSPINOSUS, Hall.

Pl. 15, Fig. 6.

Platycrinus subspinosus, HAuL, 1858. Geol. Report Iowa, Vol. I, part II, p. 536, pl. 8,
figs. 9 and 10. :

Bony, including the summit and second radials, subhemi-
spherical, being nearly flat below and gibbous above; decahedral
in outline, as seen from beneath, with the arms and second

: radials removed. Base pentagonal in outline, flat or scarcely
. visible in a side view, broadly and deeply concave in the mid-
dle; margins distinctly beveled; sutures a little impressed near

the beveled lateral margins. First radials hexagonal, as seen
from below, joining nearly horizontally around the base, but
curving abruptly upwards on each outer lateral margin. to con-
nect with the interradial and crown pieces, where they have
each an addition lateral angle, not visible from beneath; lateral

174 PALEONTOLOGY OF ILLINOIS.

and inferior (inner) margins distinctly beveled, like the basal
pieces. Second radials about half as large as the first, from
the truncated outer ends of which they extend out nearly hori-
zontally, or even decline slightly below the horizon of the base,
presenting a pentagonal inferior view, and curving strongly
upwards on each side to connect with the vault pieces. Inter-
radials rather small, hexagonal or heptagonal, and rising ver-
tically from the upturned edges of the first radials. Anal
piece not much larger than the interradials, and apparently
octagonal.

The arms, after the first bifurcation on the second radial
pieces, extend out horizontally, or even decline a little at
first, and then curve gradually upwards; they all bifurcate
regularly again on the second piece, the inner subdivisions
generally bifurcating a third time on the second piece, while
one, or sometimes two of these subdivisions divide again, so as
to make 37 (probably sometimes 40) arms in the entire series.
The arms are rounded on the outside, gradually tapering; and
immediately after the last division, each is at first composed of
one, two, or three wedge-formed pieces, beyond which they soon
pass into a double series of small alternating pieces, supporting
on the inner side a double row of thick, closely-arranged tenta-
. cles.

The summit is composed of various formed plates, each
of which rises in the middle into a short spine or prominent
tubercle. These pieces extend out from the vault, so as to
form the summit of each ray nearly to the second bifurcation.
The anal opening is small, lateral and surrounded by small,
rather protuberant pieces. Entire surface finely and rather
_ obscurely granulose.

We are under obligations to Mr. Charles Wachsmuth, of Burlington, Lowa,
for the use of the beautiful, unique specimen from which our figure and descrip-

' tion of this species have been made out. It is one of the finest, if not the finest ~

specimen of Platycrinus ever found, being so completely detached from the
matrix that almost every part of the skeleton, excepting the column, which is

.

INVERTEBRATES. . LS

wanting, can be seen nearly as well as in a living Crinoid. It is evidently
closely related to P. discoideus of Owen and Shumard (Owen’s Report Wiscon-
sin, lowa and Minnesota, p. 588, pl. 5 A, fig. 1a, 10), with which Dr. Shumard
thinks it may be identical; but as neither the specimen described by Prof. Hall,
nor that figured by us, shows any traces of the peculiar ridges and other sculp-
turing seen on the first radial pieces of P. discoideus, we think these forms
specifically distinct.

Locality and position: Burlington, Jowa; Burlington limestone, of Lower
Carboniferous series.

Genus CYATHOCRINUS, Miller.

Synon.—Lncrinus (sp.), Urn, 1793. History of Rutherglen; (not of others).
Encrinites (sp.), Scunor, 1813. Jahrb, 91-89; Petrefact., 1820; (not Miller
and others.)
Cyathocrinites, Minuer, 1821. Nat. Hist. Crinoidea, p 85; Quenst., 1835,
Weem. Arch., p. 11, 89.
Cyathocrinus, AGASSIz, 1834. Mem. Soc. Sc. Nat. Neuch., ii, and others.
Pachycrinites, KoHwaup, 1840. Bull, St. Petersb. vii, p. 78.
2 Hupachycrinus, Mnnx and WoRTHEN, 1865. Proeeed. Acad. Nat. Sci. Phila-
delphia, p. 159.
Generic formula.—
‘ Basal plates, 5.
Subradials, 5.
Radials, 3-5, the first large and the others small.
Anal pieces, 2 or 3.

The base in this genus is composed of five pieces, which are
generally of equal size and form, and united so as usually to
present a pentagonal outline. Subradial plates five, alterna-
ting with the basal pieces; four of them more or less distinctly
hexagonal, and one heptagonal, the latter being generally trun-
cated above for the reception of the first anal piece, and some-
times supporting on its right superior sloping side, a subanal
piece intercalated between it and one of the first radials.
First radial plates large, truncated and more or less sinuous
above, for the reception of the second radials, usually all alter-
nating with the subradials. Second and third radials small, the
third being pentagonal or subtrigonal, and supporting the arms.
First true anal plate resting upon the truncated upper side of
one of the subradials, and inserted between two of the first

176 PALEONTOLOGY OF ILLINOIS.

radials. The arms are usually strong and variously branched,
each division being probably always composed of a single range
of pieces.

The vault is composed of a comparatively small number of
pieces, and is provided with a central oral, and an entirely
distinct, lateral anal opening, one of which is, according to
de Koninck and Lehon’s description, and Austin’s figures, pro-
duced in the form of a short proboscis.

In the number and arrangement of the pieces composing that portion of the
body below the arm bases, this genus is very similar to Poteriocrinus, but in
the structure of the upper part of the body, these two groups are remarkably
distinct. For instance, the vault of Cyathocrinus is comparatively very low,
or merely arched a little above the attachment of the arm bases, and provided
with a central or subcentral oral opening, sometimes a little produced asa short
proboscis, and an entirely distinct lateral anal opening; while in Poteriocrinus
the whole summit is enormously extended in the form of a great proboscis, ©
often as wide as the entire body, or sometimes much wider above, and nearly or
quite as long as the arms, with (according to Austin) a single opening at its
summit. These we regard as the most important differences between these two
genera. :

Other less striking differences, however, are usually observable between the
species of these groups, such, for instance, as the more obconical form of the
body in the typical species of Potertocrinus, which also generally have one or
two more anal pieces included in the walls of the body, below the summit of
the first radial pieces, than in Cyathocrinus. Again, in most cases, they like-
wise haye one of the first radials (that on the right of the anal series) resting
upon the truncated upper extremity of one of the subradials, instead of all
alternating with the subradials as is usually the case in Cyathocrinus. These
latter peculiarities of structure, however, are not constant in either of these
groups.

The genus Cyathocrinus, as properly restricted, seems to be, as maintained
by M. M. de Koninck and Lehon, Pictet and some others, mainly, if not entirely,
confined to the Carboniferous and Permian rocks. We are aware several species
have been referred to it from the Silurian and the Devonian strata, but nearly
all of these not clearly belonging to other established genera, present more or
less marked differences in the parts known, from the typical Carboniferous
species; while none of them are known to possess the two distinct openings in
the summit, characterizing the typical species of Chathocrinus.

The only Silurian species known to us, referred with probable correctness to

INVERTEBRATES. awd

this genus, the arms of which have been discovered, is C. bulboses, Wall (Fif-
teenth Report Regents Univ. N. Y,, p. 123, pl. 1. fig. 19-20), from the Upper
Helderberg rocks. In this the hemispherical or bulb-like body is extremely
small compared with the remarkably robust arms, which are long, spread out
horizontally, and bifurcate several times without diminishing in size, so that it is
manifest they could not have been capable of being raised into an erect or ver-
tical posture, and folded together like those of most other paleeozic crinoids.
Indeed it seems difficult to conceive how an animal with so small a visceral
cavity, could have been endowed with sufficient muscular and nervous force, to
move such ponderous arms with any degree of facility. Hence it is probable
that during the life of the animal, its arms were always extended out horizon-
tally, and spread upon the same plane, like the rays of a fan. From all its
known characters, we therefore regard it as the type of a distinct little group
from the typical forms of Cyathocrinus, notwithstanding its agreement with
that genus in the structure of the cup. For this group we would propose the
name Arachnocrinus, from the spider-like appearance of the body and extended
arms. In addition to the typical species A. bulbosus, it will doubtless include
A, pisiformis=(Poteriocrinus pisiformis, Roemer), and some other Upper Silu-
rian species. : Yan

In the August (1855) number of the Proceedings of the Philadelphia Acad-

emy of Natural Sciences, p. 159, we proposed the name Hupacuycrinus,

(ev, well; zayuc, thick; xpwov, a lily), for the reception of a curious
group, the type of which was figured by Mr. Lyon, in the Kentucky Geological
report, vol. iii, pl. 1, figs. 2,2a@ and 20, under the name Graphiocrinus 14-bra-
chialis. As little is known of the upper part of the body of this crinoid, it
is difficult to determine whether it is more nearly allied to Poteriocrinus, or to
Cyathocrinus. It differs from both, however, as well as from Graphiocrinus,
in having its arms, from their origin on the first piece after the division on the
second radial plate, composed of a double series of minute, very short, inter-
locking pieces, as well as in the remarkably solid, tumid character of its body
pieces. or the- present we place this group provisionally as a section of
Cyathocrinus, though it is quite probable it will be found generically distinct
both from that genus and Poteriocrinus. In addition to the typical species, it

Nore.—Since writing the above, a comparison of Mr. Lyon’s figures of his G.
14-brachialis, in the Kentucky Report, with de Koninck’s figures of his genus Hydreiono-
erinus Woodianus (Bull. Acad. Royale de Belgique, pl. ii), leads us to suspect that
the Kentucky fossil, as well as the other species mentioned above, may possibly fall
into Prof. deKoninck’s genus. If so, of course the name Hydreionocrinus will have to
take precedence over Hupachycrinus, and the group could not be placed as a subgenus
under Cyathocrinus. Until more is known in regard to the upper parts of these Amer-
ican forms, however, this must remain an open question.

ee) Ave. 30, 1866.

178 PALEONTOLOGY OF ILLINOIS.

includes 2. pentalobus=( Cyathocrinus 2 pentalobus, Hall), and possibly, also,
Scophiocrinus orbicularis, Hall, as well as our Poteriocrinus (Scaphiocrinus) sub-
twmidus.

CYATHOCRINUS SCULPTILIS, Hall.

Pl. 15, Fig. 2a, 20.

Cyathocrinus sculptilis, Hau, 1860. Supplement to Iowa Report, vol. i, part ii, p. 59.

Cyathocrinus scitulus, Mnrx and WortHEN, Sept., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 393. ;

Cyathocrinus sculptilis (Hani), Muzx and Worruen, June, 1861. bid, p. 148.

Bopy, below the summit of the first radial plates, basin-shaped,
about twice as wide as high, truncated at the base, from which
the sides expand rapidly upwards; composed of thick, strong,
somewhat rugose plates, which are very convex in the middle
and deeply excavated at the corners; sutures distinct. Base
small, flat, or truncated on a plane with the under side of the
subradials, so as not to be seen in a side view; columnar facet
slightly concave, occupying apparently about two-thirds the
area of the base, and perforated by a central opening equal to
one-third its own diameter. Subradial pieces about as wide as
long, directed obliquely outward and upward from the base;
four of them pentagonal and one hexagonal, there being no
visible angle at the middle of the under side in any of them.
First radials much larger than the subradial pieces, about twice
as wide as high, unequal, the two on the anal side being shorter
than the others; all pentagonal, distinctly truncated and a little
concave above, the upper side being much longer than either
of the others; some of the superior lateral angles apparently a
little truncated, as if for the reception of small interradial pieces.
Anal piece about the size of the subradials, subquadrangular,
widening from the base upwards. Height to summit of first
radials, 0.36 inch; breadth, 0.71 inch; breadth of base, 0.23
inch; length of subradials, 0.21 inch; length of longest first
radial, .0.23 inch; breadth of ditto, 0.33 inch.

INVERTEBRATES. 179

The very prominent central portions of the subradial pieces are truncated
below on a plane with the base, and project out horizontally from it in such a
manner as to form a distinct five-rayed star, as seen from below. From near
the middle of each subradial there is a rather obscure angular ridge, extending
along each side of its prominent central portion to the base, and others con-
necting with similar ridges on the first radials and anal piece above. The very
profound excavations between the prominent central portion of the subradials
extend in so as to produce a slight emargination in the outer extremity of each
basal piece, while the depressions between the first radials produce a similar
indentation in the extremity of each subradial. Judging from the obliqueness
of the superior truncated side of the first radial plates, it is manifest that the
succeeding radials must have extended very obliquely outwards and upwards.

Prof. Hall’s Supplement to the Iowa Report did not reach us until our
description of this species, published in the Proceedings of the Academy of
Sciences, was in type; and from the necessarily hurried manner in which we
were then compelled to make comparisons, we overlooked the identity of the
form under consideration with his Cyathocrinus sculptilis. The fact that he
had described the first anal plate as being “‘heptagonal,” and the second ‘‘quad-
rangular,” with its “‘upper margin on a line with the summits of the adjacent
radials,” led us to think our specimen clearly distinct. A subsequent more
careful comparison, however, with his diagram (page 60, Supplement to Iowa
Report), has satisfied us that he had inadvertently described one of the subra-
dial pieces as the first anal plate, and the first anal piece as the second. When
these corrections are made in his description, it agrees so very nearly with our
crinoid that we can scarcely entertain a doubt of their identity.

Locality and position: Burlington limestone, Burlington, Iowa.

Genus POTERIOCRINUS, Miller.

Synon.—Encrinus and Astropodia (sp.), Ure, 1793, Hist. Rutherglen.
Poteriocrinites, MinuuR, 1821, Nat. Hist. Crinoidea, p. 68; Schlot., 1823, Naturg.
Z. Petref. Th. 1, p. 82; Blainy., 1834, Man. Act., p. 260, and various others.
Poteriocrinus, AGASSiz, 1834. Mem. Soc. Sci., Neuch., p. 197, and most sub-
sequent authors.
2 Scaphiocrinus, Haut, 1858. Iowa Report, vol. i, part ii, p. 550.
2 Celiocrinus, WuitH, 1863. Boston Jour. Nat. Hist., vol. vii, p. 499.

Generic formula.—
Basal pieces, 5.
Subradials, 5.
Radials, 1 (large) 4-5, and a variable number of smaller ones.
Anals, 4 to 6.
Arms variously divided, according to the species.
Vault, greatly produced in the form of a large proboscis.

F
*
{

180 PALAONTOLOGY OF ILLINOIS.

Tur body in this genus is usually obconical, with the five
basal pieces united.so as to form a more or less depressed pen-
tagonal cup. Three of the five subradials are of the same form,
and two on the anal side are more variable, and generally have
each one or two sides more than the others. The five first
radials are usually larger than the others, and connect with
each other laterally, so as to form a part of the walls of the
body; four of them are pentagonal, and alternate with the sub-
radials, and the other generally hexagonal and often, though
not always, raised with its summit above the others, while its
base usually rests directly upon the upper truncated margin of
one of the subradials.

The succeeding radial pieces vary in number, size and form
in the various species, or even in the different rays of the same;
there being sometimes as many as thirteen or more in one ray,
and only from two to about five in the others. All of the
radial pieces above the first series are free; or, in other words,
those composing the different rays are not connected laterally,
so as to form a part of the walls of the body. The anal pieces
are somewhat irregular in their arrangement, but generally one
of the first two rests between the superior sloping sides of the
two irregular subradials, while the other is supported upon the
truncated upper side of one of the subradial pieces; above these
there are from two to four other anal pieces connected with
the base of the proboscis.

The vault or summit of the body is enormously developed in the form of a
great cylindrical, or ventricose trunk, generally at least as wide as, or in C:xlo-
crinus much wider than, the cup below, and nearly or quite as long as the
arms, while its single opening is said to be located at its upper extremity.*
De Koninck and Lehon think it was, in some species, merely protected by a
soft integument, but in all the various species in which we have seen this part,
it was composed of numerous small, very regular, close fitting, hexagonal plates,

* We follow Austin and others, in giving the upper extremity of the proboscis as
the position of the opening of the summit, not having seen this opening in any of the
specimens of this genus we have examined.

INVERTEBRATES. 181

as in Dendrocrinus and some other allied genera. In P. missouriensis, Shumard,
(P. longidactylus, Shumard, Missouri Report, pl. B, fig. 5), as well as several
other species we have examined, including some of the Scaphiocrinus group,
numerous slit-like pores are seen passing through the vertical zigzag sutures,
between alternate ranges of these small pieces, so as to present much the appear-
ance of the ambulacra of the Hchinoids, excepting that these pores are not
round, and do not pierce the pieces themselves, but pass through the sutures.

As already remarked, in connection with the description of that genus, the
group under consideration is in some respects closely similar to Cyathocrinus,
but differs remarkably in the size and structure of the superior parts of the
body, as well as in some less important points of structure in the body below
the arms. For all these differences see remarks on page 176. In the arrange-
ment of the pieces of the body below the arms, it agrees almost exactly with
Hydreionocrinus, de Koninck, though it differs completely above, in its arms
being free, instead of united Jaterally so as to form a kind of cylindrical tube.

It is much more nearly allied to Zeacrinus, of Troost, from which it differs
mainly in its larger and more protuberant base, more numerous and narrower
radial pieces, as well as in the different form and proportions of its subradial
and anal pieces. As Zeacrinus, however, i some of its species, approaches
very nearly certain forms of Scaphiocrinus,* which seems not generically distinct
from Poteriocrinus, it may be found that both Scaphiocrinus and Zeacrinus should
be ranged as subgenera under Poteriocrinus.

If the type of Graphiocrinus, de Koninck and Lehon, should be found, as
suggested by Mr. Lyon and Dr. Shumard, to have a series of five minute basal
pieces within the range regarded as such by de Koninck and Lehon, which is
highly probable, then it could not be distinguished, even subgenerically, from
the typical species of Scaphiocrinus, in which case, the older name Graphiocri-
nus would replace Scaphiocrinus.

The groups Scaphiocrinus, Hall, and Oceliocrinus, White, as originally intended
by their authors, appear to be sections or subgenera under Potertocrinus. The
first, Scaphiocrinus, as represented by the typical species, S. simplex, differs
from Poteriocrinus proper, and approaches Zeacrinus, in having its base much
smaller and less protuberant, and in being provided with but two primary radial
pieces to each ray, while it also has but a single anal piece below the summit of
the first radial pieces. Such are the gradations presented by other species,
however, that Prof. Hall and others, who have recognized the group, have
found it necessary to include species with a larger protuberant base, and with
two anal pieces included in the wall of the cup below the top of the first radials.

* It is acknowledged (lowa Report, p. 682) that Zeacrinus intermedius, Hall, might
with almost equal propriety be referred to either Zeacrinus or Scaphiocrinus.

—

182 PALEONTOLOGY OF ILLINOIS.

So that the only distinction left would be the presence of but two primary
radials to each ray, while Prof. Hall has referred some species possessing this
latter character to Potertocrinus proper.

The group Celiocrinus, so far as known, seems to differ from Scaphiocrinus
only in having the proboscis venticose or balloon-shaped above, instead of cylin-
drical, while it differs from the typical forms of Poteriocrinus both in that
character and the presence of but two primary radial pieces in each ray. It is
possible, however, that when the position of the opening of the summit is
determined in Celiocrinus, that it may be found to differ from that of Poterio-
crinus proper. Dr. White thinks it must be situated near the base of the
proboscis, as he could find no traces of it in specimens where all the upper parts
of the proboscis were well preserved.

In accordance with the views of de Koninck and Lehon and other authors,
we regard the genus Poteriocrinus as dating back at least to the Upper Silurian
Epoch. Two English species have been referred to it from that horizon by
de Koninck and Lehon ( Cyathocrinus goniodactylus, and C. capillaris, Phillips);
while Homocrinus scoparius of Hall (Paleeont., N. Y., iii, pl. 1), certainly agrees
with the typical forms of the genus far more nearly than the type of Scaphio-
crinus, Which Prof. Hall, and all others, place as a section of Poteriocrinus. In
fact it seems to be in every respect a typical Poteriocrinus—whether we regard
its general physiognomy, the form and structure of its proboscis, its rays or
body, with the single slight exception of having the lower one of its two anal
pieces, below the top of the first radials, isolated from those above the one con-
necting with its right superior sloping side. But if this very slight peculiarity
of the lowest anal plate excludes this species from Poteriocrinus, how can that
group include as one of its sections Scaphiocrinus, in the type of which this lowest
anal plate is entirely wanting, and the whole physiognomy more widely different?
Again, if this arrangement of the lowest anal plate excludes it from Poterio-
erinus, how can it, upon such a basis of classification, be referred to Homocri-
nus ?, the type of which (HZ. parvus) presents the marked difference of having
the lowest anal piece resting directly down upon the basal pieces, to say nothing
of the wide differences in the structure of the arms. :

The genus Poteriocrinus also occurs in the Devonian rocks, both in this
country and Europe. PP. minutus, Roemer, is a European example; while
Prof. Hall has described several species from the Hamilton division of the
Devonian of this country. The so-called Cyathocrinus ornatissimus, Hall, from
the Portage group of N. Y., is probably also a Poteriocrinus, judging from the
figure.

It was during the Carboniferous epoch, however, that this genus undoubtedly
attained its greatest development, and we have no evidence of its existence
after the close of that period of our earth’s history.

a
&

INVERTEBRATES, 183

PoTERIocRINUS SwALLoyl, M. and W.

Pl. 16, Figs. 4a, 40.

Poteriocrinus Swallovit, Mnnx and Worrsen, Sept. 1860. Proceed. Acad. Nat. Sci.

Philad., p. 394.

Bopy below the arms abconical, or tapering regularly down
to its connection with the column; composed of smooth, nearly
flat plates, connected by linear sutures. Base small, basin-
shaped, truncate below, and widening gradually upwards, about
half as high as wide, and composed of nearly equal pentagonal
pieces; columnar facet comparatively large, a little concave,
without a marginal rim, and pierced by a pentapetalous cen-
tral opening, apparently less than one third the diameter
of the column. Subradial plates unequal, some of them as
long as wide, and others wider than long, three hexagonal, and
two on the anal side, which are larger than the others, hepta-
gonal. First radial plates smaller than the subradial pieces;
all wider than high, pentagonal, and truncated above, the upper
side being longer than either of the others. Second radials
very short, about twice as wide as high, some of them some-
what wedge-shaped, or a little longer on one side than the
other. Third radials short, or about twice as wide as high,
four of them pentagonal and supporting the principal divisions
of the arms on their superior sloping sides. In the anterior ray
the third radial plate, instead of being a bifurcating piece, is
truncated a little obliquely above, and succeeded by thirteen
other radials; all of which, excepting the last, are very short,
and alternately a little wedge-shaped; while the last one is
larger than the others, pentagonal in form, and supports two
divisions of the arms, similar to those in the other rays above
the second bifurcation.

_ The first anal piece is pentagonal and rests between the
upper sloping edges of two of the subradials, while its right
superior sloping side supports one of the under sides of a first

184 PALAONTOLOGY OF ILLINOIS.

radial; and its left side connects with another anal piece, rest-
ing upon the truncated upper end of one of the sub-radial pieces.
On the truncated upper margins of these two anal pieces two
others are supported, but our specimen is not in a condition to
show their form, or to enable us to determine whether or not
they are succeeded by any other anal pieces above.

The arms are all long, robust and rounded, those of the
two posterior, and the two lateral rays, after the first bifurca-
tion on the third radial piece, bifurcate again on the ninth
piece, beyond which they seem to be simple, and are each com-
posed of a single series of short, somewhat wedge-shaped joints.
The column is composed, near the body, of firmly anchylosed
segments, the sutures of which are not visible 0.20 inch below

: its connection with the base. Its central cavity presents in a
transverse section, the same pentapetalous form seen in the
central perforation of the base. Length to summit of third

, radial pieces, 0.86 inch; breadth at the summit of the first
radial pieces, about 0.60 inch.

Fig. 3.
This species seems to be

more nearly allied to Poteriocri- ZA
nus missouriensis, of Shumard, Z
than to any other with which ay ANS
‘ we are acquainted. It differs, te) en
however, in having a less grad-
ually tapering body (though the ran » Kooy

specimen we have figured is com-
pressed so as to give its body a

broader appearance than is nat- ioe Cy ;
ural), and much stronger arms, & Ct
which differ entirely in their LS
mode of branching, as well as oo
in the form of their segments.
Our species has also a propor-

Poteriocrinus Swallovi.

tionally praallee column at its Diagram of body and rays to the bifurcation on the third —
junction with the base. Itwas radial pieces. Natural size.

-named in honor of Prof. G. C. Swallow, State Geologist of Kansas.

Locality and position: Same as preceding.

INVERTEBRATES. 185

Genus ZEACRINUS, Troost.

Synon.—Cupressocrinus (sp.), McCoy, 1849. Ann. Mag. Nat. Hist., 2d Ser., Vol. ii, p.
244; (not Goldf., 1832.)
Poteriocrinus (sp.), Dt Konincx and Levon, 1854. Recherch. Crinoides, p. 91;

and of some others.
Hydreionocrinus (sp.), DE Kon1ncx, 1858. Bull. Acad. Royale Belgique, 2d Ser.,

t. iii, p. 19.
Zeacrinus (TRoosT), Haun, 1858. Iowa Report, Vol. i, part 2d, p. 541.

Generic formula,—
Basal pieces, 5, small, and often hidden by the column.
Subradials, 5.
Radials, 24-5, or often 3, 4 or more, in the anterior ray.
Anal pieces, 4 to 6 or more, visible between the arms.
Interradials, 0.
Arms, 10 to 40. is

THE species embraced in this group have the body rounded
below, with the five very small basal pieces sunken in a con-
cavity, and often nearly or quite hidden by the column. The
five* subradials are sometimes long, narrow, suboval or lanceo-
late, with a more or less pentagonal outline, excepting one on
the anal side, which is often hexagonal. The primary radial
series all alternate with the subradials, and are so wide as to
connect laterally, so as to leave no spaces for interradial pieces;
each consisting of two pieces, excepting in the anterior ray,
which has usually three or more. Anal pieces, from four to
six or more visible between the arms—two to three of them
forming a part of the wall of the cup below the arms, as in
Poteriocrinus.. Summit unknown.

The species composing this group, although differing in general appearance,
are closely related in structure to Poteriocrinus, but, as already stated in the
remarks upon that genus (page 181), they differ in having the body rounded
below, and the base very small and sunken; the arms are also usually less
elongated and broader, as well as always with only two primary radial pieces,
excepting in the anterior ray, which generally has more. Unfortunately we -
know nothing of the structure of the vault in this group, though judging from

* In one species (Z. elegans, Hall,) there is apparently an abnormal sixth subradial.
—24 Avo. 31, 1866.

186 PALEONTOLOGY OF ILLINOIS.
analogy, it was probably, as in Poteriocrinus, produced upwards as a large pro-
boscis. : .

If the type of Graphiocrinus, de Koninck and Lehon, as suggested by Mr.
Lyon and Dr. Shumard, should be found to have five minute basal pieces
within the range described as basals by de Koninck and Lehon, it is not im-
probable that the group under consideration may be so connected with that type,
through such forms as the typical species of Scaphiocrinus, that it will become
necessary to unite the whole as members of one group. If so, de Koninck and
Lehon’s name would have to stand for the entire group, unless Graphiocrinus
and Zeacrinus should both be regarded as forming distinct subgenera under
Poteriocrinus.

So far as known to us, the Zeacrinus group is confined to the Carboniferous
rocks ; though Prof. Hall has described two species he refers to this genus
from the Waverly Sandstone of Ohio, regarded by some as belonging to the
Upper Devonian.

ZEACRINUS TrRoostANuS, M. and W.

Pl. 16, Fig. 2.

Zeacrinus Troostanus, Mnnx and WoRTHEN, September, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 390.

Zeacrinus scoparius, Hauu, Feb., 1861. Descr. Crin. (Prelim. Notice, Albany), p. 8.
Bopy depressed, basin-shaped below the arms, rounded and
concave on the under side; composed of apparently smooth
plates, which are connected by linear sutures. Base, small,
concave, and nearly or quite hidden by the column. Subra-
dial pieces unequal in size, a little wider than long, excepting
the largest one on the anal side, four of them hexagonal, and
one or two heptagonal, (counting three angles at the base).
First radials nearly twice as wide as high, pentagonal, the
superior horizontally truncated edge being longer than either
of the inferior sloping sides. Second radials about the size of
the first, wider than high, pentagonal, and indistinctly hexag-
onal; all longer on the inferior truncated side than either of
the others; apparently four of them supporting on their supe-
rior sloping sides the first divisions of the arms, while the fifth
on the anterior side is truncated above, and succeeded by three

INVERTEBRATES. 187

_ other very short, wide pieces, upon the last of which the first

divisions of the arms rest.

Two of the anal pieces are visible in our specimen, resting
upon the largest subradial, and apparently each supporting, or
connecting with, one of the inferior lateral edges of a first radial
on each side. It is of moderate size, pentagonal, and supports
a smaller piece of unknown form, on its upper truncated side,
while its left superior sloping edge connects with another small
piece, apparently of a pentagonal form, resting upon a short
truncated upper side of one of the subradials.

The arms are nearly flat, or but slightly rounded on the
outer side, and bifurcate again after the first division on the
second radial pieces (in the lateral and posterior rays), on the
eighth, tenth and eleventh pieces; one of each of these divi-
sions subdivides again on the twelfth or fourteenth piece, be-
yond which they all appear to be simple. The entire length
of our specimen, to the extremity of the arms, is about 1.50
inches. Height of body, to summit of second radials, 0.20;
breadth of do., at the top of second radial pieces, near 0.40
inch.

This species is related to Zeacrinus ramosus, Hall,
(lowa Report, p. 549, pl. ix, fig. 3,) but differs in
having its arms more flattened, and broader on the
outer side. They also bifureate léss frequently, and
‘the number of pieces between the bifurcations is con-
siderably greater. Its second radials are likewise pro-
portionally shorter, as are all the arm pieces. Again,
all the divisions of its arms are given off much less

obliquely than in Z. ramosus. The specific name was

given in honor of Prof. G. Troost, deceased, former
State Geologist of Tennessee, and the founder of the

Zeacrinus Troostanus,
Somewhat enlarged. genus.

If Zeacrinus should be hereafter found to be synonymous with Graphioeri-
nus, a8 has been suggested, the name of this species would of course become
Graphiocrinus Troostanus.

Locality and position: Burlington, Iowa, Burlington Limestone, of Lower

Carboniferous series.

188 PALAONTOLOGY OF ILLINOIS.

Genus STROTOCRINUS, M. and W.

(otpwroc, spread; xpwvov, a lily; in allusion to the spreading summit.)

Synon.—Actinocrinus (sp.), Hatt; Muzx and Worruen, and others; (not Miniur.)
Calathocrinus, Haut (subgen. Actinocr.), Feb., 1861. Descr. Crinoid. Prelim.
Notice, p. 12; (not von Muyzr, 1848, Leonhard and Bronn’s Jahrb., p. 469.)
Generic Formula,.—
Basal plates, 3.
Subradials, 0.
Primary radials, 3-+-5.
Secondary ditto, 1 to 24+ 10, and succeeded by tertiary and other divisions,
which, with the interaxillary, interbrachial and vault pieces, unite to form
a greatly expanded, ten rayed, horizontal disc, completely isolating the anal
and interradial areas from the vault, and supporting the free ascending
arms around its margin.
Interradial pieces, 9 to 10, or more.

Anal pieces, 9 to 13, or more; the first one resting upon the basals.
“Arms, 30 to 72, or more.

LEED
wir,

Strotocrinus perumbrosus ?

This figure shows the expanded summit, natural size, as seen from below,
with the body broken away—some portions of the outer margin of the dise be-
ingrestored. The radiating bars seen within the central cavity are the parti.
tions between the canals leading out to the rays. These canals are variously
divided and subdivided in the expanded dise, before reaching the arm bases

around the margins. The very small oral opening of the summit is seen a
little below the middle. .

INVERTEBRATES. 189

Tuts is another type, agreeing exactly with Actinocrinus in
the number and arrangement of the pieces composing all that
part of the body below the divisions of the rays. Above this,
however, in the structure of the succeeding parts, to the bases
of the free arms, it is remarkably different. After the first
division of the rays, another bifurcation takes place on the
secondary radials, and of the latter divisions the two outer
usually consist of a succession of brachial pieces, while the two
inner divisions continue on for some distance, sending off on
each side alternating lateral division or ranges of brachial
pieces, so as to produce a great number of arms. The spaces
between all the divisions, out to the bases of the free arms, are
occupied by small intermediate pieces, which, together with
the brachial and other divisions, unite and spread out horizon-
tally or at right angles to the axis of the body, so as to form an
enormously expanded rim around the summit (see cuts No. 5 and
7), which isolates the anal and interradial.areas from the vault,
and bears the small, free, ascending arms around its margin.
The vault is nearly flat, composed of numerous small pieces,
and extends out to the farthest limits of the expanded summit,
so that, as seen from above or below, it presents the appearance
of a broad, flat, more or less distinctiy ten-rayed disc. As in
Actinocrinus, the arms are simple, and consist each of a double
series of small, interlocking pieces. The body, below the ex-
panded summit, in the species of this group, is more or less
elongate-obconical, and usually somewhat truncated at the base
(see cut No. 7, on p. 192), so that, with its greatly expanded
summit and flattened vault, it presents a symmetrical, urn-
shaped outline. The body plates are usually more or less
costate, and sometimes beautifully rayed.

Like various other groups of palzeozoic Crinoids, as the genera are now under-
stood, the genus Strotocrinus includes two sections, distinguished as follows:
Section a.—The typical species, with a small, simple, subcentral opening in the vault.
without a projecting proboscis.
Including the typical species, Strotocrinus perumbrosus and S. regalis=
(Actinocrinus perumbrosus and A. regalis, HALL).

190 PALEONTOLOGY OF ILLINOIS.

Section b.—Species with a subcentral proboscis, bearing the opening at its upper
extremity.

Strotocrinus erodus, S. liratus, S. umbrosus, S. subumbrosus, S. xgilops and

S. glyptus=(Aetinocrinus (Calathocrinus) erodus, A. liratus, etc.Haun),

The differences between the physiognomy of the species of this group, and
that of the types upon which the genus Actinocrinus was founded, are so strik-
ing as to attract the attention of the most casual observer, and render their
separation easy, even at a glance, where the entire body can be seen. We
therefore regard them as forming a natural group, that should be separated
generically from Actinocrinus,* particularly as it is now known that that group,
as usually defined, would include a very large number of species in this country,
. presenting a great diversity of forms, and departing often widely from the
original type in various ways. It has usually been the practice of naturalists
to separate into distinct genera, upon less sharply defined characters, the species
of a very large group, than would be done in cases where the species are less
numerous. Although this may not, in all cases, be philosophical, it is certainly
convenient, and is, as we believe in the present instance, required by a correct
classification of these extinct forms.

Accustomed, as paleeontologists have most generally been, to distinguish the
genera of crinoids almost entirely by the number and arrangement of the pieces
composing that part of the body below the arm-bases, without regard in many
cases to the most marked differences in other parts, it is not probable that the
genus under consideration will be at once generally accepted, but that the pro-
priety of such a separation will be ultimately admitted, we have no doubt.

The transition from this genus to Acéinocrinus, is through some sections of
the Batocrinus group, as we have defined it; and in some cases, where the
margin of the expanded summit has been evenly broken away, as represented
in the figures of Strotocrinus (Actinocrinus) wmbrosus, Hall, in the Iowa Report,
pl. 11, these forms might be confounded generically with such species of the
Batocrinus group as Actinocrinus xqualis, Hall, represented by fig. 4 of the
same plate. It will be observed, however, that even in this case there are
characters by which these types can be distinguished by a careful observer.

Tn the first place, the species of the group under consideration, always have
the body below the horizon of the arms, more elongated in proportion to the
height of the vault than in Batocrinus. Again, in Batocrinus the body plates
are scarcely ever marked with radiating coste, as we usually see in Strotocri-
nus. Another readily observed distinction is, that in the Batocrinus group the
second primary radial pieces, are almost, if not quite, invariably quadrangular,
and generally wider than high, instead of hexagonal, as in Strotocrinus. This

* Prof. Hall first proposed to separa‘e this type as a subgenus under Actinocrinus,
but used for it the preoccupied name Calathocrinus.

INVERTEBRATES. _ 191

latter character may seem to be one of little importance, but when we remem-
ber that it is coexistent with the other distinctions, it becomes of more signifi-
cance than it would otherwise be. Where the specimens of Strotocrinus have
the margins of the expanded summit entire, they will be at once distinguished
from any known examples of Batocrinus, or the other type of the Actinocrinidx.
As is known to be the case in several species of
Actinocrinus, Agaricocrinus, etc., some species at
least, of Strotocrinus, were provided with a pecu-
liar, convoluted internal plate, resembling the
shell of a Bulla, or Scaphander, placed with its
longer axis so as to coincide with that of the body
of the crinoid. The annexed cut represents this
organ as it occurs in its natural position, in a bro-
ken specimen apparently of S. regalis,=(Actino-
erinus regalis, Hall). As seen in the specimen,
however, it is thickly coated with small crystals of
carbonate of lime, not represented in the cut.
Strotocrinus regalis. Prof. Hall mentions seeing a similar plate in S.

Showi the body, with Ua a :
eee ae and a part of erodus—=(Actinocrinus erodus, Hall), as well as in

si d in order to exhibit : ene re
me BOC acieA tsuial orcas con- Species of Agaricocrinus (Deer. new sp. Crinoidea,

nected with the digestive apparatus. By olim, Notice, p. 12, 1861), but makes no sugges-
tions in regard to its nature or probable use in the internal economy of these
animals.* We have likewise seen this organ in Actinocrinus rotundatus, Yandall
and Shumard, and have little doubt but it existed in all the Actinocrinidx, and
possibly other families of palzeozoic crinoids. We regard it as corresponding to
the spongy axis and spiral plate around which the digestive canal in Comatula
europa passes, (see Muller’s figures of this axis and plate in Abandl. Akad.
Wissinsch, Prelim., 1841, pl. 5). 1t differs, however, in being a simple plate
rolled up somewhat like a scroll of parchment, or the shell of a Scaphander,
instead of being wound around a spongy axis like the thread of a screw. The
discovery of such an organ in these older types of Crinotdea, is of much interest,
since it seems to settle the question in regard to their having been provided
with an internal digestive apparatus, as in the living types—a fact that has been
recently questioned by Dujardin and Hupe, who appear to think they were
nourished by absorption over the whole external surface.

GEE
LEE

Ny

* Since the foregoing remarks were written, and the accompanying cut prepared, we
observe Prof. Hall has published in the March number of the Am. Jour. Sci., vol. xli,
p. 261, 1866, a note, in which he mentions seeing this plate in Actinocrinus longirostris,
A. pentagonus, A. Verneuilii, and some of the forms we have included in Strotocrinus,
and states that on showing one of the specimens to Prof. Agassiz, he remarked that
he had seen a similar organ in Comatula.

192 PALZONTOLOGY OF ILLINOIS. “

So far as known to us, this group is confined to the horizon of the Burling-
ton limestone of the Subcarboniferous series, and unless Actinocrinus costus, of
McCoy, from the Carboniferous rocks of Ireland, may possess the expanded
summit of this genus, it would seem to be peculiar to America.

STROTOCRINUS REGALIS, (sp.) Hall

Pl. 16, figs. 6a, 66, and following cut.

Actinocrinus regalis, HaALu, 1860. Sup. lowa Report, p. 8. ;
Actinocrinus speciosus, Merk and Wortuen, Sept. 1860. Proceed. Acad. Nat. Sci.
Philad., p. 386.

Strotocrinus regalis.—(Nat. size.) .

Side view, showing the body with part of the expanded summit broken away. When
entire, the expanded summit extended out at least as far as indicated by the dotted lines.

Bopy attaining a large size, elongate obconic below the hori-
zon of the arms; composed of moderately convex, ornately cos-
tate plates, which are joined by more or less impressed sutures. —
Base, cup or basin-shaped, twice as wide as high, truncated
below, for the reception of the column, and expanding mod-
erately upwards—composed of regular, subequal, hexagonal
plates, with broadly and deeply grooved sutures; facet for the
reception of the end of the column flat, rather large, or nearly
half as broad as the summit of the base, marked by radiating

INVERTEBRATES. 193
strie, and provided with a small, scarcely projecting rim,
which is not interrupted by the sutures—perforated by a nearly
round, central opening, near one third the diameter of the
head of the column. First radial plates large, the posterior
ones being smaller, and proportionally narrower than the
others; all generally longer than wide; three of them hexa-
gonal, and two heptagonal. Second radials, rather smaller than
the first, about as wide as long, all hexagonal. Third radials,
rather smaller than the second, generally a little wider than
long, heptagonal in form, and each supporting on its superior
sloping sides, two smaller heptagonal or octagonal secondary
radials, which appear to have been each surmounted by two
tertiary radials, or possibly in part, brachials. Resting between
the superior sloping sides of the third radials, is a small hexa-
gonal, interaxillary piece, evidently surmounted by others, the
number and forms of which are unknown.

First anal plate nearly as long as the first radial on each
side of it, but narrower and distinctly smaller than the ante-
rior first radial, heptagonal in form, and surmounted by two
much smaller hexagonal, and one pentagonal pieces in the
second range; in the third range there are four still smaller
pieces, and above these others, the number, form and arrange-
ment of which cannot be determined in the specimens described.
First interradial plates each nearly or quite as large as the
second radials, hexagonal or heptagonal in form, and sur-
mounted by two or three smaller pieces; above the latter there
are apparently about three other ranges of two pieces each,
which is as far as our specimen shows them.

The surface of the plates is neatly ornamented by narrow,
sharply elevated ribs, about four to six of which radiate from
the central region of each plate, to each of its sides, excepting
below the middle of the first radials, where there are usually
about eight or ten. The costae on the other plates are less
numerous in proportion to the size of each, and like those on

45) Szpt. 1, 1866.

ee ee a ae a oe er
te

194 PALAONTOLOGY OF ILLINOIS.

the first radials, extend to the sides—those crossing any one
side being all arranged parallel to each other, so as to form
with those on the adjacent plates, a series of concentric, equi-
lateral triangles. Sometimes these coste are, on the upper
plates, notched or more or less irregularly interrupted, while
on some of the upper interradial plates they show a tendency
to become broken up into little, spine-like projections. Height
(on the anterior side) to the summit of the third radials, 1.89
inch; breadth at the top of the third radials, 1.65 inch; breadth
of base, 0.84 to.0.90 inch; height of do., 0.46 inch.

The foregoing characters were given by us from a specimen from which the
summit and all the parts above the first secondary radial pieces, are broken
away. We had compared it carefully with a weathered specimen returned by
Prof Hall, with the name <A. regalis attached, and as our specimen not only
presents some differences in the details of its sculpturing, but differs in having
three instead of two plates in its second range of anal pieces; thus giving a
heptagonal instead of a hexagonal form to its first anal piece; while it also has

Fig. 8. a greater number of pieces in
<p the third and fourth ranges

D SS of the anal series, and has the

. _ interradial spaces so drawn

; a 4 inwards above as to apparent-

“3 ly indicate that it had not the
OO summit dilated above, as in
a Gat A. regalis, we supposed it to

© be distinct, and described it
‘ce under the name A. speciosus.

Since publishing our descrip-

e A tion, however, we have had,
RI ‘Gc through the kindness of Mr.

ae or Charles Wachsmuth, of Bur-

7, p. 192) agreeing almost ex-
actly in form, general appear-
; ance, and the sculpturing of its
PUENTE _ plates, with our crinoid, and

About half natural size, Made out from the specimen is ‘
figured on plate 16, figure 6. yet showing clearly that it

has the dilated summit, and structure of the upper parts seen in A. regalis.

lington, an opportunity to ex-
E&Y amine a fine specimen (see fig. ©

INVERTEBRATES. 195

Hence we can scarcely doubt that these specimens both really belong to the
species described by Prof. Hall, with which Mr. Wachsmuth’s specimen also
7 agrees in the number and arrangement of its anal and interradial pieces.

Mr. Wachsmuth’s specimen shows it to be a noble species, attaining a length
from the base to the summit of the vault, of 2.50 inches; while its dilated
summit, must have measured, when entire, nearly 3 inches in breadth, and
P that of the body just below, about 1.80 inches. Its vault is almost perfectly
: flat, and seems to be provided with a small, nearly central opening. The num-

ber of free arms must be very great, though no specimens we have seen are suffi-
ciently well preserved to show their exact number. Prof. Hall says there are
seventy-two in the entire series.
As may be seen from our figures, this species closely resembles in form, and
; the arrangement of its plates, as well as in its surface markings, a species de-
scribed by Prof. McCoy, under the name A. costus, from the Carboniferous
rocks of Ireland, (Synop. Carb. Foss. Ireland, pl. 26, fig. 2). It is rather more
attenuate, however, and has a more protuberant and more truncated base, while
it is very improbable that the Irish species (the upper part of which is
unknown) has the dilated summit of the group to which the American form
belongs; at any rate no Huropean species showing the characters of that type,
has yet, so far as our knowledge extends, ever been found.

Locality and position: Burlington, lowa; Burlington limestone, of the Sub-
carboniferous series.

Genus STEGANOCRINUS, M. and W.

(otevavoc, covered; xpwvoy, a lily; in allusion to the covered free rays.)

Synon.—Actinocrinus (sp.), Haun, 1858. Lowa Report, vol. i, part 2d, p. 577 and 582;
. Meek and Worthen, Sept., 1860. Proceed. Acad. Nat. Sci., Philad., p. 387;
(not Miller, 1821.)

Generic Formula.—

Basal plates, 3.

Subradials, 0.

Radials, 3-L5.

Interradials, 3 to 6 (or more?) +4,

Anals, 3 to 10 or more.

Rays, from the third primary radial pieces, forming greatly produced, free,
arm-like appendages, either bifurcating or simple, which are covered, their
entire length above, by small plates, and provided on each side with a row
of alternating true arms. Vault, with a subcentral proboscis.

4

196 PALAONTOLOGY OF ILLINOIS.

a

From the foregoing form-
ula it will be seen that this
type agrees exactly with Ac-
tinocrimus in thenumber and
arrangement of the pieces
composing the body, as far
as to the third radial pieces,
but differs remarkably in the
structure of its rays beyond.
These rays, as may be seen
by the annexed figure 9,
extend out horizontally to
a great length, in the form .
of tubular, free, rigid, arm-
like appendages, covered all
Pes the way out with small
. * pieces like those of the
Steganocrinus pentagonus (natural size). 6
This cut shows the upper side of the body and the cover- vault; while they are com-

ed free rays, with portions of the true arms as given off on

each side of the rays. Fig.ais an enlargement of one of posed on the under side

the true arms, as seen on the under side. Fig. d shows

the structure of the free rays, as seen from above, with of a single range of pieces

DOR Gali Saoaeica ee oudhun os HE: (see d, fig. 9), strongl

Se ae p DB?) o SOME
centre of the body. curved up on each side, and
giving off alternately on either side the true ascending arms,
composed each of a double series of small alternating pieces,
bearing the tentacles. These long, free, arm-like rays, some-
times bifurcate on the third radial pieces, while in other in-
stances they are simple, being composed of a series of very
gradually diminishing pieces, the first of which scarcely differs
from the third radial, upon the truncated upper side of which
it rests, or from those following, all of which are in a direct
line with the primary radials of the body. Hence in these
instances there might be said to be an indefinite number of

radial pieces to each ray.

INVERTEBRATES. 197

The annexed cut will show the structure of
one of these simple rays in S. sculptus,=
(Act. sculptus, Hall). Of their entire length
we cannot speak positively, as they are in-
complete in all the specimens we have seen.
In one instance, however, one of them is seen
to extend 1.53 inches from the body, or nearly
three times the breadth across the body below
the rays, at which point it is broken off.
Where the pieces covering these arm-like rays
have been removed, the cavity within is seen
Steganocrinus seutptus, tO be very slender, and slightly flexuous at

patnt ove tthe veep. the points where the true arms are given off,

ith the arm-b : . .
side; arepresentsapartot exactly as in the rays of the typical species
the free ray, with its arm-

bases and covering plates, §, pentagonus, as seen in fig. d, of cut 9, on the

as seen in a side view; and

(D xepresdnts oa transverse Opposite page. As much asthey resemble arms,
we can but regard them as really extraordinary extensions of the
body, and the little tentacle-bearing appendages on each side
as the true arms.

In some instances the first brachial piece, at the base of the
first true arm in S. sculptus, is larger in one of the rays, than
represented in the annexed cut, and presents somewhat the ap-
pearance of their being a bifurcation on the third radial, but it
is easy to see that there is not a true bifurcation, but that the
radial series continue directly on, giving off arms alternately
on each side. Of course Prof. Hall was mistaken in describing
this species as having only three arms to each ray.

The vault in the known species of this type terminates in a
subcentral proboscis, and the visceral cavity is provided (at
least in the typical species (A. pentagonus of Hall), with a spiral
Bulla-like organ, as in other types of the Actinocrimde. ;

Of course we do not expect those paleontologists who insist upon including
in the same genus all the species of crinoids that agree in the number and
arrangement of the pieces composing the body, without regard to the most

198 PALHONTOLOGY OF ILLINOIS.

extraordinary differences in the other parts, will adopt this genus. Believing
as we do, however, that the whole combination of characters presented by the
entire structure of these animals should be taken into consideration in their
classification, we can but regard the differences between this type and the typi-
cal forms of Actinocrinus as being of generic importance.

At present we know of but three species that can be with any degree of con-
fidence referred to this group. These are the typical species, S. pentagonus=
(Actinocrinus pentagonus, Hall), S. sculptus=(Act. sculptus, Hall), and our
S. araneolus, first described by us as Actinocrinus arancolus. We have little
doubt, however, but several other species referred to the genus Actinocrinus,
from our Carboniferous rocks, will be found to belong here.

So far as known, this group is confined to the Subcarboniferous rocks of
America.

STEGANOCRINUS ARANEOLUS, M. and W.

Pl. 15, Fig. la, 10.

Aectinocrinus araneolus, Meux and WortuEN, Sept., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 387.

Bopy small, much depressed, stelliform as seen from above
and below, in consequence of the deeply excavated character
of the interradial spaces; composed of obscurely granulose
plates, which are more or less distinctly costate and angular
on the under side of the body. Base small, flat, and subhex-
agonal; columnar facet round and nearly flat. First radial
plates extending out horizontally on a plane with the base,
strongly convex and angular in the middle, from which a more
or less prominent angular ridge radiates to each of the sides;
all slightly broader than long, and hexagonal or heptagonal, .
the central angle at the base of the latter being very obtuse.
Second radial pieces nearly as large as the first, wider than
long, distinctly curved upwards at each side, and more or less
convex in the middle, from which an obscure angle sometimes
extends to the side, connecting with the base, and one to each
of the lateral margins, presenting a hexagonal outline as seen
from below, but possessing an additional angle on each side,

~

INVERTEBRATES, 199

only seen in a lateral view. Third radials of the same sizé as
the second, from which they project out horizontally; strongly
curved upwards at the sides to connect with the small vault
pieces extending out over each ray; pentagonal in outline, as
seen from beneath, but having an additional angle on each side
not visible from below.

Third primary radials supporting on each of their outer
sloping sides the divisions of the free rays, only the bases of
which we have seen attached to any of the specimens yet found,
though from the fact that the rays are free from the second
radials, and covered above by small vault pieces, it is evident
the species belongs to the group Steganocrinus.

First anal plate near two-thirds as large as the first radials,
hexagonal in form, and supporting two smaller hexagonal
pieces in the next range. Above these there are three or four
others in the third range; but they belong, perhaps, nearly as
much to the vault as to the anal series, though they generally
connect with the second, and partly with the third, primary
radials on each side.

First interradials about two-thirds as large as the first
radial pieces. They are a little longer than wide, regu-
larly hexagonal, and support on their superior sloping sides
two smaller pieces, which connect with the vault.

The summit is depressed, and composed of small, somewhat
irregular pieces, which are more or less convex, while some of
those extending out over the free rays, between the body and
the bifurcation, rise into little conical nodes like those covering
the free divisions of the rays beyond. The subcentral proboscis
is slender, rises abruptly from the depressed vault, and is near
the base, composed of very prominent plates, which probably
form short spines farther up. The costee on the body plates
are mainly formed by the deep excavation of the corners of these
pieces, so as to leave a ridge extending from the middle to each
side of the same. Breadth of the body of the largest specimen,

200 PALAONTOLOGY OF ILLINOIS.

measuring across between the rays, 0.45 inch; height of ditto,
0.32 inch; breadth of free rays before bifurcation, 0.14 inch;
breadth of the divisions of ditto, at the base, 0.10 inch; breadth
of proboscis at base, 0.17 inch.

This species is most nearly allied to S. pentagonus, but will be readily distin-
guished by its smaller size and much more depressed form. This difference of
form is most obvious in a side view, its base being truncated so as not to be
seen projecting beyond the subradials, upon which the body rests when placed
on a plane surface in its natural attitude.

Locality and position: Burlington limestone, of the Subcarboniferous series,
Burlington, Lowa.

Genus ACTINOCRINUS, Miller, 1821 (page 147).

ACTINOCRINUS CONCINNUS, Shumard.

Pl. 15, Figs. 94,"90.

Actinocrinus concinnus, SHUMARD, 1855. Missouri Report, plate A, figure 5.

Actinocrinus validus, Menx and Wortusn, Sept., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 384.

Bony of medium size, subglobose in form, exclusive of the
third radial and secondary radial pieces, the summit being more
depressed than the cup below the arms. Calyx beneath the
top of the second radial plates, somewhat rounded on the sides,
and composed of thick, convex, radiately costate plates, con-
nected by moderately distinct sutures. Summit composed of
smaller irregular tuberculose pieces, and provided with a nearly
central proboscis; anal and interradial spaces deeply sinuous.
Base small, truncated and slightly concave below, about four
times as wide as high, not provided with a continuous marginal
rim, composed of nearly equal plates, with deeply grooved
sutures between ; columnar facet nearly two thirds as broad as
the base, concave and marked by fine, radiating strie. First
radial plates generally a little wider than high, two of them
hexagonal, and three heptagonal, the angle at the middle of

INVERTEBRATES. 201

the lower side in the latter being obtuse. Second radials a
little wider than long, hexagonal, about one-half to two-thirds
as large as the first radial plates, and ranging a little more
obliquely outwards. Third radial pieces smaller than the
second, from which they extend out almost horizontally; cre-
nate transversely, their lateral extremities curving up to con-
nect with the vault pieces extending out over the rays, hepta-
gonal in form, and each supporting on its outer sloping sides,
one or two secondary radials, which also project out horizon-
tally.

The first anal piece is nearly as large as the first radials,
about as wide as long, hexagonal in form, and supports on its
superior sloping sides two smaller pieces, one of which is hex-
agonal, and one heptagonal ; above these there are in the next
range four smaller pieces, which connect with the vault pieces
above. The first interradial plates are about the size of the
second radials, as long as wide, hexagonal and heptagonal, and
support two or three smaller pieces in the next range.

Of the distinct radiating costee on the first radial plates, from
three to four pass across to the sides by which they are con-
nected together, and from each to the base, while one or two
extend to the margins connecting with the second radials, and
first interradials above. The third radials are somewhat con-
stricted at their connection with the second radial pieces, and
more or less tumid above, but have no distinct coste. Height
to top of third radial plates, about 0.65 inch; do. to top of
vault, near 0.95 inch; breadth of body between the rays, 0.90
to 1 inch; breadth of base, from 0.42 to 0.45 inch; height of
do., 0.12 inch.

This species is somewhat allied to A. stedlaris, de Koninck and Lehon (ech-
eaches sur les Crinoides, Belgique, p\. 3 and 4), but has a more depressed summit,

and more convex sides below the arms; while its first and second radial plates,
and first interradials, are larger and more convex, as well as much more strongly

6 Szpr, 3, 1866,

bo
Sy
bo

PALHONTOLOGY OF ILLINOIS.

Fie. 11. costate.* Another difference of still
\ greater importance is, that in the species
yy now under consideration the third radial

pieces project so strongly outwards, and
ae) the anal and interradial spaces are so
nly, deeply sinuous, that these pieces (as seen

from below) appear connected with the

ie - (a WO body by the inner margin only; while in
(3 authentic specimens of A. stellaris, from

ee Belgium, now before us, they are so

& Re) deeply implanted between the second
e range of interradials, as to be scarcely

i visible from below. Again, in A. ste/-
laris, there is but one secondary radial

between the first and second bifurcations

Actinocrinus concinnus—(Near nat, size). of each ray, while in the American spe-
cies there are two.

Locality and position: Cedar creek, Warren county, Illinois; Burlington
limestone, of the Subcarboniferous series.

AcTINOCRINUS scrTuLUS, M. and W.

Pl. 15, Fig. Ta and 7d.

Actinocrinus scitulus, Mnnk and Worruen, Sept., 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 386. 4

A. rusticus, Hatt, Feb., 1861. Descrip. Crinoidea (Prelim. notice), p. 2; Boston
Jour. Nat. Hist., vol. vii, p. 267.

Compare A, Sillimani, M. and W., June, 1861. Proc. Acad, Nat. Sci., Philad., p. 134.

Bopy rather under medium size, more or less nearly urn-
shaped, the summit being depressed-convex, and the calyx
below the arms abconical, with a truncated, slightly expanded
base; sides expanding regularly from the base to the third
radials, above which the secondary radial and first brachial
pieces extend out horizontally, leaving excavated anal and
interradial spaces between the clusters of arms. Base of mod-

* We should remark here, that the Belgian specimens of A. stellaris, with which we
are making the comparison, are more strongly ribbed than those figured by de Koninck
and Lehon, and far more nearly like the American form under consideration.

|
|

INVERTEBRATES. 203

erate size, more than twice as wide as high, truncated and
concave below, where it is as wide as at the summit, and pro-
jects below the end of the column; margins so deeply notched
at the sutures as to present a distinctly trilobate appearance as
seen from below; columnar facet round, about one-third as
wide as the base, and provided with a minute central perfora-
tion. First radial pieces a little wider than long, two of them
heptagonal and three hexagonal, widening from the base to
the lateral angles, and each provided with a prominent, com-
pressed, central node, extending somewhat obliquely outwards
and downwards, from which one or two rather angular ridges
pass down upon the basal plates. Second radial pieces between
one-half and two-thirds as large as the first, distinctly convex,
or each having a more or less distinct central node, about one-
third wider than high; two of them pentagonal and three hex-
agonal. Third radials as wide as, or wider than, the second,
but rather shorter, three pentagonal and two heptagonal, sup-
porting on each of their superior sloping sides a smaller second-
ary radial piece, each of which is surmounted by two smaller
pieces, which, if they are both brachials, would make four
arms to each ray, or twenty in all; but there are some appear-
ances of another bifurcation on each inner piece, which would
make thirty arms.

The first interradial pieces are about as large as the second
radials, and, like them, are each provided with a central node.
They are as long as wide, regularly hexagonal, and support on
their superior sloping sides two smaller pieces in the second
range, and two or three in the third, which connect with the
vault above and with the brachial pieces on each side. The
first anal plate is sometimes nearly as large as the first radials,
hexagonal in form, and supports in the second range, two
rather smaller hexagonal or heptagonal pieces; above these
there are two others, which connect with the third radials and
secondary radials on each side, and with the vault above.

204 PALEONTOLOGY OF ILLINOIS.

The summit is composed of irregular, convex pieces, of various
forms, and provided with a slender, subcentral proboscis, rising
rather abruptly from its surface. Height to summit of vault,
0.66 inch; do. to top of third radials on the anterior side, about
0.50 inch. Breadth of base, 0.35; height of do., 0.14 inch.

Breadth across the summit, between the rays, 0.61 inch.
Fig. 12. Fig. 13.

Actinocrinus scitulus. (Natural size.) O CO oe
Diagram showing the’anatomy out to ©
the second divisions of the rays. ; 1 :
A. Sillimani. (Enlarged two diameters.)
Cut showing the anatomy of this form, for com-
parison with A. scitulus. The specimen being in

abetter condition, shows the secondary and
Tertiary radials more satisfactorily.

This species is nearly related to A. verrucosus, Hall (lowa Report, vol. 1,
part 2, pl. 10, fig. '7), but differs in having its summit much more depressed,
and composed of less tumid plates, while its proboscis is more slender, and rises
more abruptly from the vault. It also differs in having but five, instead of
seven or eight, anal pieces below the horizon of the arms, and the nodes on its
body plates are more prominent, and of different form. It is true most of these
peculiarities are of a kind, in which individuals-of the same species in this
genus sometimes vary to a greater or less extent, but in the depression of its
vault, and the less tumid character of the pieces composing it, as well as in the
slenderness of its proboscis, the individuals of the form under consideration
vary but little, and are readily distinguished from A. verrucosus.

On comparing this species with Prof. Hall’s description of his A. rusticus,
and with specimens identified with it by Mr. Wachmuth, of Burlington, Iowa,
we have scarcely a doubt of their identity. Farther comparisons of additional
specimens, since describing our A. Sillimani, have also nearly convinced us
that the latter was likewise founded upon a variety of this variable species.
The type of A. Sillimani has the body and base more depressed, and the nodes
on its body plates much more prominent; it also differs in having a distinct

INVERTEBRATES. 205

rib passing up each of the rays, and their subdivision, out to the arm-bases,
and in the forms of some of the pieces. ‘These characters give this crinoid a
very distinct aspect, but the structure being essentially the same, we are led,
since seeing several specimens showing various intermediate gradations in these
characters, to regard these forms as probably belonging to the same species.

We had not seen Prof. Hall’s description of A. rusticus* until after our diag-
nosis of A. Sillimani was printed, or we should certainly have observed its
exact agreement with the type of the latter.

Locality and position: Upper part Burlington limestone, of Subcarbonifer-
ous series, Burlington, Iowa.

Suscenus BATOCRINUS, Casseday. (See p. 150.)

SECTION D.

ACTINOCRINUS DODECADACTYLUS, M. and W.

PY, 15; fig. 3a, 36, 3'c:

Actinocrinus dodecadactylus, Mzrx and Worruen, June, 1861. Proceed. Acad. Nat.
Sci., Philad., p. 131.

Bopy rather small, subglobose; summit and calyx below the
arms, of nearly the same size; breadth a little greater than the
height; composed of slightly convex, smooth or subgranulose
plates, which are connected by moderately distinct sutures.
Base small, much depressed or subdiscoidal, obtusely hexa-
gonal in outline, with three other obtuse, retreating angles at
the sutures. First radial plates wider than long; three of them
recularly hexagonal, and two heptagonal. Second radial pieces
much smaller than the first, about twice as wide as long, and
all quadrangular. ‘Third radials a little longer than the second,
all regularly hexagonal, the two inferior lateral margins being
very short, and the two superior sides each about equaling the
base. In the two posterior rays the third radial pieces each

* We of course allude here to his description published in the Boston Journal Nat.
Hist., vol. vii, p. 269, and not to his very brief preliminary notice of three lines, pub-
lished in some sheets issued at Albany in Feb., 1861, in which the formula of the arms
was said to be, ‘‘as far as known, four to each ray.”’

206 PALAONTOLOGY OF ILLINOIS.

support, on one of their superior sloping sides, a large brachial
piece, and on the other a secondary radial of near the same
size, which in its turn supports two brachial pieces, making
three arms to each of these rays; while in all the others two
brachial pieces rest directly upon the third radial, thus making
only twelve arms in the whole series.

The first anal plate is about as wide as the first radials, but
a little longer, being longer than wide, instead of the reverse.
It is regularly heptagonal, and supports on each superior late-
ral sloping side, a smaller heptagonal piece; while an elonga-
ted, coffin-shaped piece rests upon its short, superior, truncated
side between the two latter, and extends up, flanked on either
side by the first brachials, to the summit. Hach of the inter-
radial spaces is filled by a single, ovate, octagonal piece, about
as large as the second and third radial pieces taken together.

The vault is composed of rather large, somewhat regularly
arranged plates, which are very nearly flat, the smaller ones
all being on the anal side; the proboscis is small, and located
nearer the anal than the dorsal side. Height to base of pro-
boscis, 0.50 inch; breadth, 0-58 inch; breadth of base, 0.23
inch.

Fig. 14. This symmetrical little species is so nearly like A. roéun-
BGO dus, of Shumard (Greol. Report Missouri, p.191, pl. A,
SF} =e fig. 2, 2a, 2b), that it might readily be confounded with
IRS WG: it, although it is clearly distinct. In the first place it is
oe i HO less distinctly rotund than that species, while it differs in
OL O Wales being entirely destitute of secondary radials, excepting a
SS © O& single one on one of the sloping sides of the third radial
Actinocrinus dodecadacty- piece in each posterior ray ; while in A. rotundus there are
lus—(Natural size). two of these pieces, one upon the top of the other, resting
upon the superior sloping sides of each third radial. This difference in the
arrangement of the parts gives twenty arms in Shumard’s species, while in
ours there are only twelve. Again, our species has but a single interradial
piece in each space, while in A. rotwndus there are from two to three. The
anal pieces are likewise more numerous in Shumard’s species than in ours,
while its plates are more flattened, and its sutures less distinct.

ee ee.

%.

INVERTEBRATES. 207

Knowing that the number of arms sometimes varies to some extent, in dif-
ferent specimens of the same species of crinoids, we were at first inclined to
think the form under consideration might be only a young specimen of A. ro-
tundus, but on comparing it carefully with specimens of that species of the
same size, we find they possess the usual number of arms (20) 1n all our speci-
mens, and uniformly present the other differences mentioned.

Locality and position: Same as preceding.

ACTINOCRINUS ASTERISCUS, M. and W.

Fig. 15, fig. 8a, 8b and 8c.

Actinocrinus asteriscus, Mnnx and WorTHEN, Sept., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 385.

Actinocrinus xquibrachiatus, var. alatus, Wann, dany., 1861. Boston Jour. Nat. Hist.,
vol. vii, p. 263.

Compare A. xquibrachiatus, McCunsney, Jany., 1860. New Paleozoic Fossils, from
Western States, p. 25. ;

Bopy rather under medium size, much depressed, the under
side being somewhat more convex than the vault; stelliform
as seen from below or above, in consequence of the excavation
of the interradial spaces; sides expanding rapidly and curving
outward, so as to bring the third radials, secondary radials and
first brachial pieces all upon a horizontal plane; plates rather
thin, apparently subgranulose, flattened, and separated by close
fitting sutures. Base small, rounded and destitute of a distinct
marginal rim, two and a half to three times as wide as high.
First radial plates wider than long, three of them hexagonal
and two heptagonal, the angle at the middle of the base of the
latter being very obtuse. Second radials small, about twice as
wide as high, pentagonal and hexagonal. Third radials some-
what larger than the second, pentagonal or occasionally hexa-
gonal, about twice as wide as high, and each supporting on its
superior (or more properly outer) sloping sides, two secondary
radials; these are each succeeded by another, which in its turn
supports two of the brachial pieces, making in all four arms to
each ray, or twenty in the entire series.

208 PALEONTOLOGY OF ILLINOIS.

The first anal plate is a little smaller than the first radials, a

heptagonal in form, and supports three smaller pieces in the
next range, two of which are hexagonal and one heptagonal;
above these there are two other still smaller pieces, and over
the latter, in the fourth range, three large arcuate plates, con-
necting with the vault above. The first interradial pieces are
of moderate size, as long as wide, hexagonal, and each support-
ing two smaller pieces in the next range; above the latter there
are two or three larger, alongate pieces in the third range,
which arch inwards and connect with the summit.

The vault is depressed, composed of numerous medium sized
convex pieces, and provided with a subcentral proboscis. The
arms are all broken from our specimens, but judging from the
size of the openings, they would appear to be very slender.
They seem to have ascended vertically from the upper side of
the second brachial pieces. Height to the base of the proboscis,
about 0.50 inch; ditto to arm openings, 0.35 inch; breadth
across from side to side, between the interradials, 0.67 inch ;

greatest breadth across between the arm openings on opposite
sides, 0.93 inch.

This form is thought to be a variety of A. xquibrachiatus of McChesney, in
which opinion we are inclined to concur, since seeing Prof. McChesney’s figures,
recently published. As we have not yet seen specimens showing al/ the inter-
mediate gradations, however, connecting these two forms, although we have
several of each before us, we are not fully satisfied that we should consider
them identical. They are certainly very similar, there being no difference of
specific importance in the structure or arrangement of the parts composing the
body. The differences that must distinguish them, either as species or varie-
ties, are the more depressed and distinctly lobed form of the asteriscus, the
interradial and anal spaces being excavated nearly half way in from the arm
bases towards the center, so as to give the body a very distinctly five-lobed out-
line, instead of having merely slightly sinuous margins, as seen from above or
below. It will also be seen, from our figures, that even the axillary and inter-
brachial spaces in our crinoid are also somewhat sinuous, while the lobes formed
by its arm bases are more flattened, and its base more rounded, than in the
aquibrachiatus. At the same time that we are prepared to believe our form
may prove to be only a variety of A. xquibrachiatus, it is certainly more distinct

INVERTEBRATES. 209

from that species than A. cnornatus of Hall is. So that if we unite A. asteriscus
and A. xquibrachiatus, we would apparently have to include A. imornatus also.
To one unacquainted with the imperceptible gradations by which such an ex-
tremely divergent form as this is connected with the Batocrinus group, it would
seem like an unnatural arrangement to include it; yet it is so connected as not
to be separable more than specifically from others that shade into the typical
forms of Batocrinus.

Locality and position: Upper part of Burlington limestone, Lower Carbonif-
erous series, Burlington, Iowa.

Genus AMPHORACRINUS, Austin.

Synon.—WMelocrinites (sp.), Goupr. Novy. Act., vol. xix, p. 341; (not in Petref., vol. i,

p. 197, 1826).

Amphora (sp.), CUMBERLAND, 1826. Reliquiz Conservate, p. 36.

Actinocrinus (sp.), Portiuock, 1843. Report Geol. Lond., p. 347, and of vari-
ous others; (not Miller, 1821). -

Melocrinus (sp.), BRonn, 1848. Index, p. 719.

Amphoracrinus, AusTIN, 1848. Quart. Jour. Geol. Soc., Lond., vol. iv, p. 292;
(not Roemer, 1852. Bronn’s Leth. Geog., vol. ii, p. 250, tab. iv, fig. 15).

Dorycrinus, Rommur, 1853. Wiegm. Arch., p. 207.

‘TE generic formula of this group is precisely that of Actinocrinus, with per-
haps the exception of more generally having a small number of anal and inter-
radial pieces. It is distinguished from that genus, however, by having the
opening of the summit lateral, directed outwards, and penetrating a thickened
protuberance composed of small pieces. In some instances the opening is not
much more lateral than in particular examples of section (c) of the true Actino-
crinus group, which consists of species without a proboscis; but even in these
cases it still differs in being directed outwards, or in being placed upon, or
rather penetrating, a protuberance, which usually extends down the anal side,
So as to separate the two posterior rays more widely than the others; while the
arm-bases are nearly always more in groups, and more protuberant than in
that section of Actimocrinus. Again, the species of Amphoracrinus are usually
distinguished from the typical forms of Actinocrinus in generally having the
second primary radial pieces quadrangular, instead of hexagonal, and the body
plates, with very rare exceptions, without radiating coste. In the latter
characters they agree with the Batocrinus group, from which, however, they
are readily distinguished by their lateral opening without a proboscis, as well as
by nearly always having their arm-bases and the adjacent parts forming five

~protuberant lobes. They likewise differ from all sections of Actinocrinus, as

eal iy Serr, 4, 1866,

210 PALAHONTOLOGY OF ILLINOIS. a

we understand that genus, in having the vault very frequently armed with one
or more strong, sometimes greatly elongated spines.

Of all the types included as subgenera, under Actinocrinus, by those who give
the widest limits to that genus, the Amphoracrinus group is most nearly allied
to Agaricocrinus and Megistocrinus, which we exclude from Actinocrinus, and
regard as most probably forming two separate and distinct genera from cach
other, as well as from that under consideration. That they both, however,
(particularly the former) so closely approach Amphoracrinus, through a few
intermediate forms, as to be sometimes with difficulty distinguished, is no less
true than that very nearly all the known species can be readily separated into
these three groups. The chief distinctions between Agaricocrinus and _Amphora-
crinus consist in the more depressed form of the body and the concavity of
the under side of the former, by which its arm-bases are brought down upon a
horizon with the lowest part of the body. The arms in this group are also
stouter, and if we mistake not, invariably consist of only two to each ray; while
in Amphoracrinus there are often three in each of the posterior rays, and some-
times three or four to each ray all around. Again, we know of no species of
Agaricocrinus that has the vault provided with elongated spines, as we often
see in the Amphoracrinus group. The transition from one to the other of these
types is through such forms as Actinocrinus planobasalis, A. brevis, A. corniculus
and Agaricocrinus pentagonus, Hall.

The Megistocrinus group seems to us to preserve its integrity as a genus more
decidedly than Agaricocrinus, although not differing always so widely, in general
appearance, from certain species of Amphoracrinus as the typical forms of
Agaricocrinus do. Still, even these forms, approaching most nearly Amphora-
erinus, differ in their more broadly rounded under side* and more depressed
summit, while their opening never (as in Amphoracrinus and Agaricocrinus)
penetrates a thickened protuberance, but in all the known species presents the ap-
pearance of an abruptly projecting proboscis. We have never seen a specimen
with this proboscis entire, or indeed retaining more than its base; but this base
always shows thin, prominent, fractured edges, and in the typical Carboniferous
species, at least, is situated lower on the side than the opening of Amphoracri-
nus or Agaricocrinus, being upon a line with, or even sometimes a little below,
the horizon of the arm-bases. Another difference, that may seem of little

* We doubt the propriety of including in Megistocrinus those remarkable Devonian
species, with the under side broadly and abruptly truncated, and the vault provided
with a stout, nearly central proboscis, described by Mr. Lyon under the names UY.
Knappui and M. spinosulus. Nor can we agree with our friends Prof. Winchell and
Prof. Marcy in referring to this genus the elongated, obconic, Upper Silurian species
described by them under the names M, Marcouanus and M. infeliz, which belong to Sac-
cocrinus, Hall.

INVERTEBRATES. 2A

importance, is nevertheless a constant one: that is, the second primary radial
pieces in Megistocrinus are always hexagonal instead of quadrangular, as is most
generally the case in Agaricocrinus and Amphoracrinus. Again, Megistocrinus
always differs from Agaricocrinus in having the body much more prominent
below the arm-bases, and the vault proportionally more depressed.

The three species that have been supposed to show a complete transition

from Megistocrinus, through such forms as Actinocrinus unicornis, into the Am-

phoracrinus group, 7. e., Actinocrinus brevicornis, A. minor and A. superlatus, Hall
(the types of the last two of which are now before us), seem to us to be true
Megistocrinus. They have exactly the form and physiognomy of that genus,
with which they agree in all points of structure not probably due to age, and
in having all their second radial pieces hexagonal instead of quadrangular;
while the typical specimens of the species A. minor and A. superlatus show that
the opening is placed on the side slightly lower than the arm-bases, and instead
of being surrounded by a thickened protuberance, presents abruptly projecting,
fractured, thin edges, like the base of a small lateral proboscis, precisely as we
see in the typical species of Megistocrinus. It is also worthy of note that Prof.
Hall describes the other species (A. brevicornis) as having a “ proboscidiform
aperture.” Hence we regard these three forms as true Megistocrinus, and pro-
bably young individuals.

We are not sure the genus Amphoracrinus commenced its existence as far
back as during the Upper Silurian epoch, though some Hamilton group (Devo-
nian) species described in New York seem to belong to it. It was during the
deposition of the Subcarboniferous rocks, however, that it attained its maximum
development, and became extinct.

The law of priority would, perhaps, compel us to adopt Cumberland’s name,
Amphora, for this genus, were it not for the fact, that the species he evidently
regarded as the typical one was a true Actinocrinus. Cumberland gave no
generic description, but figured and described two species under the name
Aphora. He used no specific names, but numbered the species “Ist species”
and ‘2d species.” His first species, in the text, is the second on the plates.
Of the first species, he says (p. 37) ‘the plates of this fine specimen, which
is entirely hollow, are remarkably emarginated with broad borders, resembling,
on its outer form, an earthen wine Amphora, with five handles for suspension
and a central neck to pour from.” Hence it is evident the name was suggested
by this first species; and as it is a true Actinocrinus, Amphora becomes merely
a synonym of that genus, as it is, in part, of Amphoracrinus of Austin, to which
group his second and only other species belongs.

212 PALAONTOLOGY OF ILLINOIS.

AMPHORACRINUS SUBTURBINATUS, M. and W.

Pl. 15, Fig. 4a, 40.
Actinocrinus (Amphoracrinus) subturbinatus, Mrnx and Wortuen, Sept., 1860. Pro-
ceed. Acad. Nat. Sci., Philad., p. 388.

Bopy rather under medium size, turbinate or obconical below _
the arms, and depressed convex above; expanding regularly __
with straight sides from the column tothe summit of the third
radials, thence more abruptly to the arms; composed of flat,

smooth or merely granulose plates, which are connected by
close-fitting sutures. Interradial and anal spaces rather dis-
tinctly sinuous between the groups of arms. Base compara-
tively small, subpentagonal, about one-third as wide as high,
and not provided with a projecting rim; columnar facet small,
concave, less. than half as broad as the base. First radial
plates generally a little wider than long, widening from the
base to the lateral angles, two of them heptagonai and three
hexagonal. Second radials small, about twice as wide as long,
quadrangular, or rarely with one of the upper angles slightly
truncated, so as to produce a fifth angle. Third radial pieces
a little larger than the second, about twice as wide as high,
hexagonal and heptagonal, and supporting on each superior
sloping side, in the anterior and posterior rays, one small sec-
ondary radial piece, each of which gives rise to two first bra-
chial pieces, while in each of the two antero-lateral rays, the
two small secondary pieces are truncated above, and each sur-
mounted by a single brachial piece; making two arms to each of
these rays, and four to each of the others, or sixteen to the
entire series.

The first interradial plates are about two-thirds as large as
the first radials, nearly or quite as long as wide, and six to
eight sided. On the superior sloping sides of these, rest two
smaller pieces, which partly support the secondary radials, and
are surmounted by two or three irregular pieces, which extend

INVERTEBRATES. 213

up between the brachial pieces and connect with the vault.
The first anal plate is about as large as the first radials, as long
as wide, heptagonal in form, and surmounted by three smaller
hexagonal pieces in the second range, the middle one of which
projects above the others. Surmounting these, there are three

pieces in the third range, the two lateral of which each sup-
_ ports an irregular piece above, while the middle one projects
- considerably above the others, in a wedge-shaped point, and
a ‘bears on its superior sloping sides a series of protuberant

pieces surrounding the small anal aperture, which opens later-
ally a little above the horizon of the arm openings.

The summit is depressed and composed of unequal, irregu-
lar pieces, one of which over each of the rays, and another near
the middle, are usually larger than the others, and appears
to have been tumid, or may even have been extended into
short spines, so as to place it in Dorycrinus, if that name is to
be retained for a section of this genus. Height to top of vault,
0.59 inch; breadth across the summit between the groups of
arms, about 0.60 inch; do. from the arm openings on opposite
sides, 0.73 inch.

This species bears some resemblance to A. [Amphoracrinus] trinodus, of
Hall, but has the base less truncated, the vault more flattened on top, and pro-
vided with six nodes or spines, instead of three ; while it has four arms instead
of three to each posterior ray, and four instead of two in the anterior. Its
most marked characters are its short, obconical, or

Big. 15. 4
2, a turbinate form below the arms, and truncated dome.
ws ow The latter rises somewhat abruptly above the arms,

aS)
wy (Oe ‘oe Y as much as about one-third of the height of the
200) = cr cup below these, but is abruptly flattened on top, so

O aL, as to give it a truncated appearance. Our specimen
os Pec is not in a condition to enable us to determine
st ort @ whether or not the summit had spines, though some

88a CO MG remains of the larger piece over each ray, seem to
indicate that they were, when entire, quite promi-
Actinoerinus subturbinatus. nent. The sinuosities between the rays gives the
i r t size. : x
Pa eR USCC) body a pentalobate outline as seen from below.
Locality and position: Same as preceding.

214 PALZONTOLOGY OF ILLINOIS.

Genus CCELOCRINUS, M. and W. %

(xothos, hollow; xpwov, a lily; in allusion to the concave base.)

Spherocrinus, Mpnk and WorTHEN, 1865. Proceed. Acad. Nat. Sci., Philad., p. 154;
(not Roemer.)
Ceelocrinus, Menx and WorTHEN, 1865. Ib., p. 273; (not Celkiocrinus, White, 1863.*)

In this type the formula is that of such species of Actinocri-
nus as have no secondary radials, and but few anal and inter-
radial pieces, excepting that it has its opening lateral, as in
Amphoracrinus and Agaricocrinus, while its base is concave, as
in the latter genus. From Agaricocrinus, with which it per-
haps most nearly agrees, it differs in having greatly less robust
arms, which come out around the summit, instead of on the
horizon of the lower part of the body. It also differs in having
its first anal and first radial pieces curved up so as to form
nearly half the height of the lateral walls, as well as under, so
as to form most of the under side of the body. From Ampho-
racrinus it differs in the sunken character of its base, the con-
cavity of the under side, and the curved character of its first
anal and first radial pieces, as well as in having weaker arms,
and its arm-bases not projecting—there being but a single
brachial piece to each division of each ray, soldered into the
walls of the body, and these rest directly upoh the third
radials. The small lateral opening of the summit is on the
same horizon as the arms, and rather in a slight depression
than upon a protuberance, as we usually see in Amphoracrmus
and Agaricocrinus.

It is possible that we should place this as a subgenus, either under Agarico-

crinus or Amphoracrinus, though we are at present inclined to regard it as
being distinct from both.

* Some have objected to the name Celocrinus, because it is thought to be too near
Celiocrinus, of White, previously used for another type. As Dr. White’s name, how-
ever, was derived from the Greek for the belly, and the two names are otherwise quite
as distinct as many others retained in various departments of natural history, we can-
not admit the force of this objevtion.

INVERTEBRATES. 215

We know but the single typical species, which is from the Subcarboniferous
series. '

Ca@LOcRINUS concAvus, M. and W.

Pl. 15, Fig. 10 @, 106, 10 ¢.
Actinocrinus (Amphoracrinus?) concavus, Mnnk and WorTHEN, June, 1861. Proceed.
Acad. Nat. Sci., Philad,, p. 132.
Actinocrinus (Sphxrocrinus) concavus, M. and W., Aug., 1865. Ib., p. 154.
Actinocrinus (Celocrinus) concavus, M. and W., Dec., 1865. Ib., p. 273.

ce 16. Bopy small, subglobose, broader than high, a

Ree) little oblique; summit nearly flat; under side

Brees rounded and distinctly concave; sides rising ver-
HOH tically, or nearly so. Surface smooth, or sub-
aR ©) B0e granulose. Base small, concave, and entirely in-
a cluded within the concavity of the under side.

Ceelocrinus concavus,

(Natural size.) Hirst radial plates comparatively large, convex,

Srciare of wie body and curving under so as to form a part of the

out to the brachia
pieces inclusive, vith concavity below; two- of them heptagonal and

the position of
minute lateral snalthree hexagonal. Second radial pieces wanting

opening at a.
= = of the rays (of the specimen before us); in the
others small, wider than long, and quadrangular in form.
Third radial pieces smaller than the second (in three of
the rays), pentagonal in form, and each supporting upon
their superior sloping sides the first brachial pieces, which
form a part of the walls of the body. First interradial
pieces comparatively large, or about one-half the size of
the first radial plates, nine sided, the superior sloping sides
of each supporting one side of two of the brachial pieces,
while two very small pieces rest upon the middle of the sum-
mit, and connect with the vault above, and with the brachial
‘vees on each side. First anal piece a little larger than the
‘als, heptagonal in form, and supporting in the next

216 PALEONTOLOGY OF ILLINOIS.

range three pieces, the two lateral of which are larger than the
other, and connect above, on their sloping sides, with brachial
pieces, while the middle piece between these is irregularly
hexagonal, and supports three very small pieces in the next
range, which connect with the anal opening and the vault
pieces above, and with the brachials on each side.

Vault made up of a few comparatively large pieces, the
central one of which is a little more convex than the others.
Anal opening very small, lateral, or on about the same
horizon as the arm openings, and surrounded by only five
plates, which are not protuberant. Arm openings twelve,
small, arranged around the margin of the summit, three to
each of the two posterior rays, and two to each of the others.
Arms apparently, from the small size of the openings, and the
very small articulating surfaces for the first free arm pieces,
very slender and fragile. Column unknown. Height of body,
0.31 inch; breadth from the anal to the anterior side, 0.42
inch; breadth of base, 0.17 inch.

In the concavity of the under side, and the incurved character of its first
anal and first radial pieces, this species presents much the appearance of a
Zeacrinus, though in the number and arrangement of the parts composing the
whole body, it will be seen to possess all the essential characters of the great
genus Actinocrinus, as it has been generally understood. We placed it provi- _
sionally in the subgenus Amphoracrinus, in first describing it, on account of the
lateral position of the anal opening, but we subsequently became satisfied that
it differs sufficiently from the species of that group to be made the type of a
distinct genus. It differs from Agaricocrinus in haying comparatively much
larger first radial pieces, and very differently formed and arranged interradials,
as well as in the general form of its body, and its much weaker arms, which
are also located around the summit, instead of around the lower part of the
body.

We are under obligations to Mr. Charles Wachsmuth, of Burlington, Iowa,
for the use of the only specimen of this species we have seen.

Locality and position: Burlington, Iowa; Burlington limestone, of the
Lower Carboniferous series.

. INVERTEBRATES, PAY

Genus GILBERTSOCRINUS, Phillips.

Synon.—Ollacrinus, CUMBERLAND, 1826. Appendix to Reliquiw Conservate (without
generic or specific diagnosis or specific name.)

Gilbertsocrinus, Puinuirs, 1836. Geol. Yorkshire, part ii, p. 207.

Rhodocrinus (part), pp Konincx and Lupo, 1854. Recherch. sur les Crinoides,

: p- 104; and of several other authors; (not Miller, 1821).

e Goniasteroidocrinus, Lyon and CAssmDAy, 1859. Am. Jour. Sci. Vol. xxviii,
(2) p. 232.

Trematocrinus, HALL, 1860. Sup. lowa Report, p. 70.

PHILLIPS’s di- »
agnosis of this
genus reads as
follows:

“Basal joints
Gilbertsocrinus calcaratus, Phillips.

five, forming a The aboye cuts are from Cumberland’s Reliquice
conservatee, where this species is figured under the

pentagon 5 SU- name of Ollacrinus. Fig. a, side view, shows the
4 1 DasesO8 dalee Binns and the openings Deroy for me
. attachment of the true arms, which latter he wrongly
pra asa [subra represented a if Dem ers ey through the
= es lates instead of passing between them. Fig. 6b
dials | five, hex- Eesente the yault with its opening, and the false
Gilbertsocrinus 5 arm bases. Fig. ¢ represents the under side, but
ise. agonal, forming does not show the divisions of the base.

This cut shows a 5

oneoftherayswith &@ Gecagon, with five re-entering angles, from,
the base of its

false arms, a,aand which proceed five heptagonal first costals [first

nearly under these

inas “From Pn. Ladials], and five hexagonal second costals [sec-
piv" ond radials], bearing a pentagonal scapula [third
radial], supporting joints [secondary radials], which combine
into rounded arms, perforated in the centre. First intercos-
tals [first interradials] pentagonal. The following species have
been usually referred to Rhodocrinus, Miller, from which, it
appears to me, they differ entirely.”

He mentions but the following three species, viz: G. calcara-
tus, @. mammillaris and G. bursa, all from the Subcarboniferous.
His generic and specific descriptions are very brief and unsat-
isfactory, but his figures are tolerably good, and give a suffi-
ciently intelligible idea of the generic characters of the group.

ae Snrr, 5, 1866.

218 PALAONTOLOGY OF ILLINOIS.

From these figures and his description, with what is now known |
of several American species of this type, it is evident that the
formula, in accordance with the later improved nomenclature,
may be stated as follows:
Generic formula.—
Basal pieces, 5.
Subradials, 5.
Radials, 3-+-5.
Secondary or supraradials, 3 or 4+10.
Anal and interradial pieces, 12 to 15-5.
Pseudo-brachial appendages (arms of some authors), 5, or rarely 6 (from
the division of one on the anal side) ; located over or between the rays.
Arm-openings (ambulacral) 10, located directly under the pseudo-brachial
appendages, or alternating with them.

The genus may therefore be characterized thus: body usu-
ally short subcylindrical. Base small, formed of five penta-
gonal pieces, composing a more or less impressed pentagonal
disc. Subradials five, alternating with the basal pieces, all
hexagonal or obscurely heptagonal, and truncated above for
the reception of the first anal and first interradial pieces;
like the first radials, often protuberant or extended in the
form of spines. Primary radials in five series, of three each,
and all alternating with the subradials; the first one of each
series heptagonal, the second hexagonal and the third hexago-
nal or heptagonal, and supporting on its superior sloping sides
the diverging secondary radials. Of the latter, there are two
or three in each range, the last one of which supports on its
inner sloping sides the delicate pendent arms; while in one
section of the genus, the outer sloping side of each of these
pieces bears another piece, which, owing to the divergence of
the secondary radials, meets the corresponding piece of each
adjacent ray (excepting rarely on the anal side) over the inter-
radial and anal spaces, and there forms the base of thesstout
false arms, which, in the typical species of the group, stand
over the interradial and anal spaces. Interradial and anal
areas oval, often scarcely distinguishable from each other, and

vis ia

usually nearly or quite isolated from the vault above; each

= aad
-*

-_

©

INVERTEBRATES. 219

occupied by from ten to seventeen or eighteen pieces. Inter-
axillary or interbrachial spaces occupied by from two to eight
or ten small pieces, the upper of which connect with the false
arm-bases and vault. True arms very long, slender, pendu-
lous, and more or less branching, supporting minute ascending
tentacula. Pseudo-brachial appendages five, or rarely six
(from the division of the one on the anal side), composed of two
ranges of pieces, with a central cavity in those of each range,
or of several ranges inclosing a double central cavity; not
furrowed above or provided with any external openings; all
extending out from the margins of the dome, at first horizon-
tally, and then bifurcating—the divisions spreading, curving
downwards, and each tapering to a point. Vault much de-
pressed, with usually a more or less marked concavity opposite
each false arm; opening sublateral, or about midway between
the centre and margin of the dome, not raised upon a proboscis.

This interesting group, as here defined, includes two sections, distinguished
as follows:

1. GILBERTSOCRINUWS, Parties (proper).—Ollacrinus, Camberland.
Pseudo-brachial appendages located directly over the interbrachial spaces; anal
and interradial pieces not quite isolated from the dome.
Examples: G. calcaratus, G. bursa and G. mammuillaris, Phillips.—(European. )

2. GONIASTEROIDOCRINWS, Lyon and Cassepay,=Trematocrinus, Hall.
Pseudo-brachial appendages located over the interradial and anal areas, which
(excepting sometimes the latter) are entirely separated from the dome.
Examples: G. tuberosus, Lyon and Casseday; G. fiscellus, M. and W., and G.
papillatus, G. reticulatus, G. typus, etc., published by Prof. Hall under the
name Zrematocrinus.—(American.)

From the foregoing description, it will be seen this genus agrees almost
exactly, in the structure of the body below the arms, with Mhodocrinus,
Miller, with which it is often confounded. It was, indeed, if we mistake not,
also originally separated from that group by Phillips, under a misapprehension
in regard to the number of basal pieces in Lhodocrinus, which had been de-
scribed as having a tripartite base. After this error in regard to the structure
of Rhodocrinus had been pointed out, by Austin and others, it is not at all
surprising that nearly all who had only seen the specimens of Gilbertsocrinus
figured by Phillips, divested of the appendages of the upper part of the body,

220 PALAONTOLOGY OF ILLINOIS.

should have regarded it as synonymous with Rhodocrinus. The following cut
however, of the upper part of Goniasteroidocrinus tuberosus of Lyon and
Casseday, with its appendages, (in which it evidently agrees with Gi/bertsocrinus,
excepting in their larger size and position over the interradial spaces), will
show, as we believe, sufficiently important differences to separate this type
entirely from the genus /thodocrinus proper.

Fig. 19. From these figures, it will
fey be seen that this type differs
so widely from Rhodocrinus,
in the structure and arrange-
ment of the appendages of
the upper part of its body, _
that the parts supposed by
Phillips and others to be
the arms, in Gilbertsocrinus,
are really not homologous
with the arms of Rhodocri-
nus, nor indeed, in any pro-
per sense, arms at all, as that
term is used in describing
crinoids, but are, on the con-
trary, curious additional ap-
pendages, composed of two
or more ranges of pieces;
and although provided with
a central cavity through
nearly their entire length,
connecting with the cavity of
the body, they have no open
ambulacral furrow above,
e nor indeed any traces what-
Goniasteroidocrinus tuberosus. ’ ever of an external opening.
PED) and. the, pecide teal anne ann c Done Cate Consequently they are not
ee
og Ee ene ee
The atone () aaseneiaetos connection of the small, ame pen- dages of the body in any

dent arms with the body, as they are seen between two of the L Suet
false arms. Crepresents the structure of the under side of the other known crinoid, and

ae are tga en and ina furstionand.0 is .05" seam to bear somewhat the
same relations to the body that the side branches of the column of Pentacrinus
and many palzozoic crinoids do to the column itself. In addition to this, the
parts in this type homologous with the arms in /ehodocrinus and other crinoids,

instead of being stout and erect, as in Rhodocrinus, are very slender, long, pendent

INVERTEBRATES. E 22%

organs (see * of cut B, fig. 19), having much the delicacy and appearance of
tentacles.

In the above cut, the minute true arms of the typical species of G'oniasteroido-
erinus, are seen to branch so as to form nine to each ray. The cut shows only
their outside, in which we have seen no indications of ambulacral furrows; but
these may have been obliterated in cleaning the specimen, or possibly they may
present the anomalous character of being on the wnder side, and thus differ
from those of all other known crinoids. As far as these arms can be traced
near the base, they are each composed of a single series of minute pieces, but
according to Mr. Lyon, they are farther down, composed each of a double
series of minute interlocking pieces.

These true arms connect with the body at the openings that suggested to
Prof. Hall the later name Zrematocrinus for this group. Such differences as
these, in the parts connected with the reproductive, and perhaps the respira-
tory organs, should surely separate this type from Rhodocrinus.

But as these organs have not yet been seen entire, in the typical European
species of the genus Gilbertsocrinus, it may be argued that we have no right to
conclude that the Goniasteroidocrinus group is congeneric with Phillips’s genus.
We think, however, that any one who will take the trouble to compare the
foregoing cuts of Goniastero(docrinus tuberosus and our figure of G. fiscellus, on
pl. 15, fig. 5, together with the other American species described by Prof. Hall
under the name Zrematocrinus, with Phillips’s figures of his typical species of
Gilbertsocrinus, and particularly with Cumberland’s figures of one of the same
species, which we have reproduced for comparison, on page 217, will agree
with us that these European species must have had these organs, with the
slight difference of relative position already mentioned, exactly as in Goniaste-
roidocrinus.* Nor can we believe the difference in the position of the false
arms, with relation to the true ones, alluded to above, of more than subgeneric
importance.

The fact that Cumberland had, in 1826, proposed the name Ollacrinus for
Phillips’s typical species, leaves us in some doubt whether we should not adopt
his name for the genus, in accordance with the rules of priority. The reasons
for doubting the propriety of adopting his name are not only that he gave no
diagnosis or description either of his typical species or of the genus Ollacrinus,

* Tt is due to Mr. Billings that we should state here, that so far as we know, he was
the first author who called attention to these two sets of appendages in Gilbertsocrinus
bursa, Phillips (Decade iii, Canadian Organic Remains, p. 25 and 26), though, owing
to the fact that he had never seen an entire specimen, he there seems to have regarded
this as the structure of Rhodocrinus. We are gratified to be able to state, however,
that he now fully concurs with us in the opinion that Gilbertsocrinus is distinct from
Rhodocrinus proper.

225 PALEONTOLOGY OF ILLINOIS.

and merely published figures on a separate supplementary plate, with the name
Ollacrinus printéd upon it, but in addition to this he did not, in his little work,
consistently follow the binomial system of nomenclature. Some of his names
are binomial, it is true, while in other instances he has such names as ‘“ Mitra
rugoso quingue perforata,” “Genus Sitularia triangulariformis,”’ etc. Hence
the rule of priority should probably not be regarded as applicable in his case.

The proposed genus Acanthocrinus of Roemer, seems to be related to Gil-
bertsocrinus, but if we have correctly understood the arrangement of the arms
of the former, it is distinct, and more nearly allied to Rhodocrinus.

So far as we know, the group under consideration seems to be almost entirely
confined to the Subcarboniferous rocks, both in this country and England.
We know of but a single species (Zrematocrinus spinigerus, Hall, found in the
Hamilton group of New York) from any other horizon, and it is worthy of note
that this species departs in some respects from the other known species of this
group, and may belong to another genus.

Suspcenus GONIASTEROIDOCRINUS, L. and C. (See p. 219.)

GILBERTSOCRINUS FISCELLUS, M. and W.

Pl. 15, Fig. 5.
Trematocrinus fiscellus, Mrnrxk and WortTHEN, Sept., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 383. :
Gilbertsocrinus ( Goniasteroidocrinus) fiscellus, M. and W.., Aug., 1865. Ib., p. 167.

Bopy short subcylindrical, longer than wide, rounded and
concave below, and nearly flat above; sides rising almost ver-
tically to near the summit, where they curve outward. Plates
subgranulose, and all convex, those of the subovate interradial
spaces less prominent than the rays, and showing a very slight
tendency to develope obscure radiating ridges near the edges;
sutures distinct. Base small, somewhat concave, obscurely
pentagonal, and included within the concavity of the under
side; columnar facet comparatively large, or occupying nearly
the whole area of the base, obscurely marked by radiating
strie, and provided with a small, pentagonal, star-shaped cen-
tral opening. Subradial pieces nearly as wide as long, trun-
cated, and narrower above than below, subquadrangular in

INVERTEBRATES. 223

general outline, but provided with a fifth very obtuse angle in
the middle below, and having each inferior lateral angle
slightly truncated. First radial pieces larger than the subra-
dials, and wedged so far in between them as to come nearly in
contact with the base, as wide as long, and heptagonal in out-
line, the sides connecting with the ‘subradials being longer than
the others. Second radials smaller than the first, about as long
as wide, hexagonal in form. Third radials of the same size as
the second, heptagonal, and supporting on their superior sloping
sides the first secondary radials, each of which is succeeded by
another, the last of which bear on their inner sides above,
the delicate pendulous arms, and on the outer sloping sides
above, one or two pieces forming the bases of the false arms.
The first interradial and first anal pieces rest upon the broad,
superior, truncated side of the subradials, which they nearly
equal in size. They are all hexagonal, the inferior edges being
generally longer than either of the others. Above these, there
are in the second range three, in the third three or four, and
in the fourth three pieces, the latter being surmounted by three
or four others; all the series diminishing gradually from below
to the summit.

The interaxillary pieces are all very small, two of them
being wedged down, one upon the top of the other, in the nar-
row space between the first and second secondary radial pieces,
while the others are arranged above, so as to form the upper
and inner sides of the two small apertures; the outer and lower
sides of which are formed partly by a sinus in the edge of the
second secondary radial pieces, and partly by one side of the
third. |

The secondary radials diverge so that those belonging to
each of the different rays (a a of diagram) meet over the
centre of each interradial space, where they support the false
arms. The first false arm pieces are not quite free, being
flanked on either side by the interaxillary pieces forming the

294 PALEONTOLOGY OF ILLINOIS.

summit of the interaxillary openings. They are all pierced
directly through the middle by small perforations. gh
The summit is very slightly convex; and composed of une- q
qual plates, the larger of which are tumid, and the smaller less
convex. -Extending from each false arm towards the middle,
there is a depression, occupied by ‘smaller pieces, while the _
larger and more convex plates occupy the prominences between. __
Height, to top of first false arm-pieces, 0.48 inch; do. to the ©
true arm-openings, 0.39 inch; do. to the top of the vault, 0.56
inch. Breadth of body below the arms, 0.51 inch.
Fig. 20.

In this diagram, showing the structure of the body out to the false-arm
bases, the anal area, and a part of each ray on that side, are restored. It

is probable, however, that the anal area may haye more plates than here
represented, as we have reason to believe it was not isolated from the
vault, like the interradial areas. The last piece of the divisions of each
ray, marked a, connect laterally over each int+rradial space, and form the
bases of the false arms. The dark spots are the true arm-openings.

The specimen from which our description is made out is defective on the
anal side, but we have seen another, apparently of the same species, consisting
of the vault and the false arm-bases, together with the sides down to the true
arm-openings, inclusive. In this the anal area is clearly not insolated from the

INVERTEBRATES. 743)

vault, and there are two false arms over the anal area, which are smaller than

_ the others, and stand one on each side of the summit of the anal space, there

being thus six, instead of five, of the false arms in this species. These smaller
false arms are probably simple all the way out, while the larger ones probably

bifureate. The anal opening “in this specimen is nearly midway between the

middle and the margin, and opens obliquely outwards, with slightly protuberant
margins.

This species is more nearly related to Gilbertsocrinus tuberculosus=( Trema-
tocrinus tuberculosus, Hall, Sup. lowa Report, page 75), than to any other with
which we are acquainted. It differs, however, in being proportionally higher,
and in having smaller and much less prominent subradials, which are but
slightly convex, and so short as to be scarcely visible in a lateral view; while
those of G. tuberculosus are described as being “ produced into strong tubercu-
liform nodes,” and extending up so as to form a part of the outer walls of the
body. It likewise differs in having its first radial plates merely rather dis-
tinctly convex, and larger than the subradials, instead of smaller and “ strongly
tuberculiform.” Again, it seems to differ in having the plates, especially
those of the interradials, somewhat excavated at the corners, so as to present
the appearance of a slight tendency to develope obtuse radiating costze at the
margins of the plates—a character not mentioned in Prof. Hall’s description.
A more important difference, however, if we are not mistaken in regard to the
specimen we have mentioned as showing the summit, being identical with the
type of our species, is, that it possesses six instead of five false arms, owing, as
it were, to the division of the one on the anal side into two, each of which latter.
are only half the size of the others. Another difference is, the more lateral posi-
tion of the opening of the summit, and the connection of the anal series with
the vault above, in our species.

Should Cumberland’s name, Ofincintioe be adopted for this genus, the name
of this species will of course be Ollacrinus fiscellus.

Locality and position: Lower beds of Burlington group of the Subcarbon-
iferous series.

ECHINOIDEA.

PERISCHOECHINID A.

(Synon.—Family Trsseies, Desor.)

RATHER widely different views are entertained amongst Zoologists and Palz-
ontologists in regard to the importance of the characters distinguishing the
Paleozoic group of Hchinodermata, under consideration, from the Mesozoic

== 29 Szpt. 7, 1866.

226 PALEONTOLOGY OF ILLINOIS.

and more modern Echinoids. Pictet, and some others, not only include these
ancient forms in the order Zchinoidea, but even view them as forming a section
of the family Cidaridx.* Desor also included them in the order, but regarded
them as constituting a distinct family, for which he proposed the name Tesseles,
and placed them, along with the Cidaride, a8 a suborder “Hndocycliques ;”+
which arrangement was also followed by Dujardin and Hupe.{ McCoy, how-
ever, had previously proposed to erect this group into a distinct order, under
the name Perischocchinide, § and Roemer regarded them as constituting a sub-
order of the Echinoidea ; || while Prof Agassiz, if we mistake not, thinks the
group falls more properly within the Crinoidea.

Without presuming to undertake the decision of a question upon which such
eminent authorities have differed, we must confess that a careful study of an
extensive series of excellent specimens of Melonites multipora, with more or less
perfect examples of Oligoporus, Palzchinus, Archxocidaris and Lepidechinus,
compels us to concur with those who regard these types as Kchinoids. Although
evidently most nearly allied to the Cidaridez, they still seem to present too
strongly marked differences to be properly included in the same suborder; and
hence we agree with Dr. Roemer in viewing them as constituting a distinct
suborder, for which McCoy’s name Perischoechinide may be retained. In a
systematic arrangement their position would doubtless be below all the other
Kchinoids, and next to the Cidaridx, thus forming a distinct suborder from
the higher Echinoids.

The reasons for adopting the conclusions that these forms are true Kchinoids
and not Crinoids, are, that in the first place, they differ from the Crinoids and
agree with a large group of the Echinoids ( Cidaride) in having an anal and an
oral opening, situated at opposite extremities of the vertical axis, with regular
ambulacra extending the entire distance from one to the other of these open-
ings, while they also possess an apical disc, composed of a series of ocular and
ovarian pieces (the latter pierced by genital pores), surrounding the anal open-
ing. Again, like the Cidaride and some other Echinoids, and unlike any
known Crinoids, they were provided with powerful jaws; while they farther
agree with the Echinoids, and differ from all the known Crinoids, in the posses-
sion of articulating spines.

We are aware the opinion has been expressed that Melonites multipora was
attached by pedicel or jointed column, like the Crinoids—an error probably
originating from the occasional occurrence of specimens crushed together in

* Traite de Paleont., iv, p. 257, 1857.

+ Synopsis Ech. Foss., p. xxvii, 1858.

{ Nat. Hist. des Zooph., Suites du Buffon, p. 461, 1865.
. @ Brit. Paleozoic Foss., p. 124, 1851.

|| Wiegmann’s Arch., i, p. 312, 1855.

- as

INVERTEBRATES. 224

the same mass with Crinoid columns, as we often see other fossils. No one,
however, we believe, who has had an opportunity to examine a good series of
specimens, entertains such an opinion at this time. Indeed, aside from all
other reasons for rejecting this view, it seems to be against all analogy to sup-
pose these creatures would have been provided with such powerful jaws, unless
’ they were free to seek and devour larger food than the minute floating objects
upon which the Crinoids probably subsisted.*

The existence of jaws in the genus Archzocidaris is shown in the figures of
A. Wortheni of Hall, on plate 26, of the Iowa Report, though no allusion is ~
there made to them in the text. We have also, now, the means of showing

Fig. 21. that the genus Melonites was provided with simi-
lar jaws. The annexed cut (No. 21) represents
these jaws as seen in a specimen of M. multipora
—the peristome being somewhat distorted and
the jaws displaced by pressure, so as to leave an
open space (x) on one side. The dark spaces
(dddd d) between the jaws are slightly restored
near the centre of the figure, where the specimen
is somewhat defective from accidental erosion.
The five radiating lines between these dark bands
are suture lines, extending up the middle of each
jaw, as we see in those of Archxocidaris and some

Oral opening (somewhat distorted) shes
Eee Melonites multipora—(nat- recent Kehinoids.
ural size).

In the number of Wiegmann’s Archives, already cited, Dr. Roemer gives
excellent figures of the general appearance, of Melonites multipora, and of the
arrangement of its ambulacral and interambulacral pieces. He also there gives
a figure of the apical disc of the same, but the last mentioned figure differs in
several respects from the specimens examined by us. In the first place this
ficure leaves a black ring around the disc, so as not to show the connection of

* The not unfrequent occurrence of Crinoids, imbedded with the shells of Platyceras
and other Gasteropods, in contact with the vault, has led some Palontologists to the
conclusion that in these cases, the Crinoid was in the act of devouring the Mollusk
at the moment when it perished. Some even seem to think that the Crinoids actually
swallowed these shells. This, however, to say the least of it, would have been a
physical impossibility, since the oral opening, when found with its margins entire, is
rarely so much as the tenth of an inch in diameter, and is also often placed at the ex-
tremity of an elongated, slender tube or proboscis, made up of close-fitting solid plates.
We also think it exceedingly improbable that the paleozoic Crinoids ever preyed upon
even the softer parts of such large objects, though we are far from being willing to
adopt the conclusion of M. M. Dujardin and Hupe, that they were entirely nourished
by absorption over the surface.

228 PALAONTOLOGY OF ILLINOIS.

the ambulacral and interambulacral pieces with the genital and ocular plates.
It also represents pores in each of the ocular pieces, and only three in four of
the genital pieces, and two in the fifth; while it represents the genital and ocu-
lar plates of nearly equal length. As may be seen by the annexed figures, the
specimens examined by us have the ocular pieces much smaller and shorter
than the others, and entirely without any traces of pores,* while one of the
specimens before us shows distinctly four pores in three of the genital plates,
and five in each Fig, 22.

of the other two.
Another specimen

tal pieces, and four
/?~ in each one of the

< others. In order

, tobe the more sure
Gi at that we were not mistaken in regard to the
‘’’ number and arrangement of the pores, we
polished the surface of the whole disc in
both of these specimens with fine emery,

Apical dise of Melonites multipora: Showin

the anal opening surrounded by the genital ino =
and anil aee and the connection of the and Owns to the white opaque character

latter with the ambulacral and interambulac- of the plates, and the fact that the pores

ral pieces. All enlarged about two diameters, . ¥ i
are filled with darker, translucent material,

the number of pores, and the relations of all the parts, could be very clearly
seen. It is probable that one of these slightly larger plates with five pores,
represents the madreporiform body, and thus faintly indicates the posterior side
of the fossil.

If the dise figured by Dr. Roemer is accurately represented, it would seem
to present a difference of even more than specific importance, from those exam-
ined by us, unless the difference. might be sexual. The latter suggestion, how-
ever, is not probable, though from all analogy we may infer that the sexes were
distinct in these fossils.

From the foregoing remarks and illustrations, it will be seen that the group
Perischoechinidee, which is entirely confined to the palzeozoic rocks, differs from

* Since this was written, we have, through the politeness of Dr. Shumard of St.
Louis, had an opportunity to examine another fine specimen, showing the disc of this
fossil. In this there are four ovarian pores in three plates, and three in each of the
other two; while in two of the occular pieces there is apparently a single pore near
one side. Hence it would appear to be the case that the individuals of this fossil pre-
sent unaccountable variations in the number of these pores.

INVERTEBRATES. 229

all the Mesozoic and more modern Hchinoids, in having from three to seven or
nine rows of interambulacral plates to each series, instead of only two (those of
the inner rows being hexagonal, and the two outer pentagonal); and judging
from what is known of Medonites, also in having a greater number of pores in
each ovarian plate, with likewise sometimes a greater number, and different
arrangement, of ambulacral plates and pores.

"Prof. McCoy has, apparently upon sufficient grounds, proposed to divide this
group into two sections or families, distinguished by the following characters :

1. PALACHINID, McCoy.

With spines small, all of one kind, and articulating upon imperforate tubercles.
Includes Melonites, Oligoporus and Palzchinus.

2. ARCHAOCIDARIDZA, McCoy.

With plates comparatively thin, and spines of two kinds—a smaller secondary
series, and a larger primary series; all articulating upon perforated tubercles.
Includes Archxocidaris and apparently Perischodomus.

It is possible Lepidechinus, Hall (which seems to be very near Perischodo-
mus, McCoy), may be found to typify a third section or family, on account of
its peculiar character of having all the plates distinctly imbricating.

Genus PALAXCHINUS, McCoy, 1844.
(Carb. Foss. Ireland, p. 171.)

Tue species belonging to this genus are usually large, oval
or spheroidal, and composed of comparatively thick plates,
which are provided with numerous small spines. In the inter-
ambulacral areas, there are five to six or eight ranges of plates,
those connecting with the ambulacra being pentagonal, and all
the others hexagonal, as in other groups of the suborder. The
ambulacra are narrow, even, or but slightly furrowed, and each
composed of two alternating ranges of small pieces, which are
wider than long. Each of these pieces is perforated at the
outer end by two small pores, arranged so as to form two
double rows, or two single zigzag ranges, to each ambulacrum.

One species of this genus is said to occur in the Upper Silurian Rocks, and
all the others known, have been found in the Carboniferous System.

230 - PALAONTOLOGY OF ILLINOIS.

PALHCHINUS BURLINGTONENSIS, M. and W.
PIG; Mies siaaoo sien

Palzchinus burlingtonensis Mux and Worrtuen, Sept., 1860. Proc. Acad, Nat. Sci.,
Philad., p. 396. P

Tue only specimen of this species we have yet seen, is too
imperfect to show the exact form of the entire fossil, though it
seems to have been nearly spherical in outline. It appears to
have only four ranges of interambulacral plates in each area,
though it is probable there are at least five, nearer the middle
than they can be traced in our specimen. At the extremities
of the interambulacral areas the number of plates is reduced
to the two lateral ranges of pentagonal pieces, all of which
have their truncated margins crenulated for the reception of
the outer ends of the small ambulacral pieces.

The ambulacra are narrow, or about as wide as the first
range of interambulacral plates on each side, and slightly con-
vex along the middle. They are each composed of a double
alternating series of very small pieces, which are two or three
times as wide as long. About five to seven of these equal the
height of each contiguous interambulacral plate, while the two
pores in the outer ends of each piece are arranged so as to form
two double, somewhat zigzag, rows in each ambulacrum.

The surface of all the plates is ornamented by numerous
granules, or bases of attachment for the small spines, from
thirty to forty of which occupied each of the interambulacral
plates, and two or three each of the ambulacral pieces.

As near as can be determined from our imperfect specimen,
it must have been, when entire, not less than 2.25 inches in
height, and near two inches in breadth. About twelve of the
ambulacral pieces occupy a space of 0.25 inch.

INVERTEBRATES. Zot

This is the first species of this ge-
nus, we believe, identified in this
country, though Prof. Hall has since
described a species from the Burling-
ton limestone, which he refers to a
section of this group. From the de-
scription given by him, however, we
are inclined to think his species dif-
fers too widely from the forms upon

Palcechinus burlingtonensis. ‘ ‘ f
Diagram showing a part of two ambulacra, and the which McCoy s genus was founded,
intervening interambulacral pieces, above the middle ] 1 Alea
of the body; all magnified near two diameters. to be properly piaced in 1t.

Locality and position: Burlington group, Subcarboniferous; Burlington, Iowa.

MOLLUSCA.

LAMELLIBRANCHIATA.
Genus AVICULOPECTEN, McCoy, 1851.

(Ann. Mag. Nat. Hist., vol. vii, p. 171.)
AVICULOPECTEN BURLINGTONENSIS, M. and W.

Pl. 16, Fig. la and 10.

Aviculopecten burlingtonensis, Munk and WortuEn, Oct., 1860. Preceed. Acad. Nat.
Sci., Philad., p. 453.

SHELL of about medium size, very thin and fragile, subcir-
cular, slightly wider than long; pallial margin regularly
rounded lateral margins; more narrowly rounded near the
middle, thence converging towards the beaks at an angle of
about 100°; hinge straight, between two-thirds and three-
fourths as long as the transverse diameter of the valves, and
ranging at right angles to the longitudinal axis of the shell.
Left valve much compressed; anterior ear of moderate size,
flat, subtriangular, the extremity being a little rounded—sepa-
rated from the margin below by a nearly rectangular notch;

252 PALEONTOLOGY OF ILLINOIS.

posterior ear somewhat larger than the other, flat, and termi-
nating in an angle of 45° at the extremity—separated from
the margin below by a wide, deep, subangular sinus, beak
compressed and located slightly in advance of the middle of
the hinge. Surface (left valve) ornamented by eighty to ninety
small, nearly equal, radiating costs, which increase by im-
plantation, and about equal the breadth of the depressions
between; costz crossed by numerous, very regular, undulating,
and distinctly imbricating, concentric laminee of growth, which
are very closely arranged and sharply elevated on the ears,
where the radiating ribs are not developed. (Right valve
unknown.) Length from hinge to base, about 2.24 inches;
breadth from anterior to posterior side, about 2.27 inches;
length of hinge, 1.68 inches; number of costa in 0.40 inch at
the ventral margin, 10 to 12; number of concentric marks in
same space, about 18.

In its peculiarly delicate surface markings, this shell closely resembles A.
ceelatus, of McCoy’, as figured in his Paleozoic Fossils, pl. 3 E, fig. 5 and 5a.
It differs, however, materially in form, its lateral margins being more abruptly
rounded, and the sinuses under the ears deeper and more angular. It also dif-
fers in being entirely destitute of any traces of radiating costze on the ears.

Loality and position: Burlington, lowa; upper part of Burlington group of
the Subcarboniferous series.

INVERTEBRATE FOSSILS OF THE KEOKUK GROUP.

PROTOZOA.
SPONGIA.
PETROSPONGIA.

Genus SPHENOPOTERIUM, M. and W., 1860. (See p. 145.)

SPHENOPOTERIUM OBTUSUM, M. and W.

Pl. 17, Fig. 2a, 26, 2c, 2d (by error a on the pl.), 2e.
Sphenopoterium obtusum, Munk and WortHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 448.

Suorr, abruptly cuneate below, wider than high; basal
edge slightly sinuous in the middle; flattened sides, expanding
rapidly upwards from the obtuse basal carina. Cells from four
to about nine, comparatively large, and of moderate depth,
conical, and where not more than iour or five, rounded and
separated by thick interstices, but becoming angular, with
thinner intervening partitions, where more crowded. Surface
striz fine, irregular, and showing a tendeney to converge
towards the middle of the base, anastomosing in such a manner
as to form a kind of shagreen-like style of ornament. Length
or height of a large individual containing nine cells, 1 inch;
breadth of same, 0.98 inch; thickness, 0.66 inch.

Locality and position: Nauvoo, Illinois; Keokuk division ef the Subcarbonif-

erous series.
==5)) Serr. 8, 1866.

As ni i

234 PALMONTOLOGY OF ILLINOIS.

SPHENOPOTERIUM COMPRESSUM, M. and W.

PAU, Bio. la orelee:

Sphenopoterium compressum, Murex and Wortuen, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 448. ;

CoMPRESSED-CUNEATE, wider than high, carinate on each late-
ral margin, and sulcate between the cells on each compressed
side; base apparently retaining remains of a scar of attach-
ment. Cells three or more, arranged parallel to the greater
transverse diameter of the body, rather deep and conical;
walls thin. Surface presenting a fine shagreen-like appear-
ance from the anastomosing of the striz. Length or height,
about 0.55 inch; greatest breadth, near 1 inch; thickness,
0.38 inch.

It is possible this may be a variety of the preceding species, though its more
compressed form, thinner walls and lateral carine, give it a very different ap-
pearance. Its surface strize are also finer and more broken up into granules.

Locality and position: same as last.

RADIATA.

ECHINODERMATA.
CRINOIDEA.
Genus CYATHOCRINUS, Miller, 1821. (See p. 175.)

CYATHOCRINUS ANGULATUS, M. and W.

Pl. 17, Fig. 4.

Cyathocrinus angulatus, Mnrx and WortHEN, Sept., 1860. Pyoceed. Acad. Nat. Sci.,
Philad., p. 391. i

Bopy rather large, strong and robust, basin-shaped below the
arms, wider than high, truncated below, and expanding rapidly
upwards; composed of very thick, nearly smooth, or subgran-

£,
&
ha
3

INVERTEBRATES. 235

ulose, tumid ‘and angular plates, which are united by distinct
sutures. Base comparatively small, and apparently truncated
on a plane with the tumid portion of the subradial plates.
Subradial plates as wide as high, four of them pentagonal, and
one on the anal side hexagonal, there being no visible angle at
the middle of the base in any of them. First radials larger
than the subradial pieces, about twice as wide as long, penta-
gonal or subheptagonal, in consequence of the superior lateral
angles of some being truncate for the reception of small inter-
radials; all broadly truncated and more or less concave above.
Second radials extremely short, but differing somewhat in
length, some of them eight or nine times as wide as long.
Third radials larger than the second, unequal in size, all wider
than high, and triangular in form. First anal plate smaller
than the subradials, a little narrower below than above, appa-
rently pentagonal in outline (the upper extremity is not dis-
tinctly seen in the specimen described), and extending some-
what above the summit of the first radials. |

Arms large, rounded and robust, apparently simple after the
division on the third radials, and composed each of a single
series of pieces, which are wider than long, and somewhat
wedge-shaped. Plates, below the second radials, remarkable
for their thickness and tumid angular character, though the
angles are not acute. On the subradials two of these ridges
pass from the middle to the base, nearly parallel to each other
(leaving a shallow furrow between), and one to each of the first
radial pieces above. On each first radial there are two similar
ridges or prominences, which diverge from near the upper side
to the base, so as to connect with those on the subradial pieces,
giving to each first radial a somewhat bilobate appearance.

Our specimen of this species is too much distorted to enable us to give accu-
rate measurements, though the body below the arms seems to have been about

0.50 inch in height, and near 1.10 inches in breadth. It is more nearly related
to Qyathocrinus sculptilis, Hall, than to any other species with which we are

236 PALMONTOLOGY OF ILLINOIS.

acquainted, but is much wore robust, while the truncate upper sides of its first
radials are not near so sloping outwards, nor so flattened. ‘he ridges on its
subradial and first radial pieces are less angular, and the surface of these plates
is otherwise smoother than in C. sculptilis, which holds a lower geological

position.

Locality and position: same as preceding.

CYATHOCRINUS SAFFORDI, M. and W.

Pl. 17, Fig. 5a, 53. ~
Cyathocrinus Saffordi, Munk and Worrtuen, Sept., 1860. Proceed. Acad. Nat. Sci.,

Pifilad., p. 371.

Bopy subglobose, wider than high, the broadest part being
below the middle, unsymmetrical (at least in our specimen),
the ventral side being much more gibbous than the other; com-
posed of thin, smooth, or finely granulose plates, connected by
linear, slightly carinated sutures. Base irregularly pentagonal,
flat, or so slightly convex as to be scarcely visible in a side
view, consisting (in the specimen before us) of unequal plates,
those on the anal side being larger than the others, slightly
protuberant at the columnar facet. Subradial plates rather
large, unequal, wider than high, four of them hexagonal (the
inferior angle being nearly obsolete), and one on the anal side
—which is considerably larger than the others—irregularly
heptagonal. First radial plates a litule longer than the subra-
dials, somewhat unequal, hexagonal, generally wider than
high, and narrowing upwards from the inferior lateral angles;
bordered above by a slender, slightly retlexed rim; sinus in
the superior edge for the reception of the second radial pieces,
small. Anal plate small, about as wide as high, quadrangular,
and like the first radials, provided with a slighily retlexed rim
above; not projecting above the margin of the radial plates ..
on each side of it. Height to summit of first radials 0.50
inch; greatest breadth, 0.70 inch. |

INVERTEBRATES. : 237

This species is more nearly allied to C. rotunda-
tus, of Hall, (Jowa Report, vol. I, part wi, p. 555,
pl. 9, fig. Ta and'7b), than to any other with

», which we are acquainted. It differs, however, in
\y beine broader in proportion to its height, and is

Saas S prop got,
more nearly of the same height on the anterior

e ) 3 lbs and posterior sides. Its plates are also propor-

- tionally thinner, while the depressions in the upper

PSY margins of its first radial plates are more shallow,

and not near so much beveled. Another marked

La difference is the peculiar character of its sutures

Cyathocrinus Saffordi.—(Nat. size.) Which are indicated by a distinct, raised line. Its

rath tee pe farm and ar first anal plate likewise differs in being truncated

psu adzal, and analipieces: very nearly on a level with the first radial on each

side, instead of projecting above. ‘They are both very irregular forms, in
which the columnar facet is much nearer the anterior than posterior side.

The specific name of the form under consideration was given in honor of

Prof. Safford, the State Geologist of eunessee.

Locality and position: White’s Creek Springs, Tennessee; Keokuk limestone.

Genus POTERIOCRINUS, Miller. (See page 179.)

Suscenus SCAPHIOCRINUS, Hall, 1858.

(Iowa Report, vol. i, part 2, p. 550.)
Subgeneric formula.—
Basal plates, 5.
Subradial plates, 5.
Radial plates, 2--5—10; or sometimes more than 2 in anterior ray.
Anal plates, 1 to 6, or more.
Interradial plates, 0.
Arms, 2-!-5—10, two from each ray, simple or bifurcating.

THIS group agrees in nearly all its essential characters with
Troost’s genus Zeacrinus, so far as the number and arrange-
ment of its parts are concerned, but differs from most of the
species of that genus, in having its body obconical, or produced
so as to show the basal pieces in a side view, instead of con-
eave. It also differs in having the second radials and the

lower arm joints proportionally longer, and contracted on the

238 PALEONTOLOGY OF ILLINOIS.

sides, while the sutures between the first and second radials,
as well as between the second radials and the first arm pieces,
are generally more gaping. In most of the species all the arm
joints are proportionally longer, and more wedge-shaped than
in the characteristic species of Zeacrinus. From the typical
forms of Poteriocrinus it differs chiefly in having but two
primary radial pieces in the posterior and lateral rays, and in
the gaping character of the sutures between those pieces.

Prof. Hall ranges this group asa subgenus under Poteriocrinus. If Troost’s
genus Zeacrinus is to be retained as distinct from Poteriecrinus, it seems to us
from the species we have had an opportunity to examine, that Scaphiocrinus
might, with about as much propriety, be placed under the former, since the
species show no fundamental differences of structure from those of that group.
In order to fully comprehend the close relations between these groups, in the
number and arrangement of their parts, it is but necessary to compare the dia-
gram of Zeacrinus ranwsus, Hall (Lowa Report, vol. I, part ti, p. 549), with his
Scaphiocrinus divaricatus (Sup. lowa Repot, pl. 3, fig. 6.)

As already suggested in another place, it is not improbable that the type of
de Koninck aud Lehon’s genus Graphiocrinus, will be found to possess five
small basal pieces hidden by the column, within the range regarded as basals
by those authors. If so, we can scarcely doubt that Zeacrinus and Scaphio-
crinus should either be grouped together as a subgenus under Graphiocrinus
(which has priority), or stand under it as two distinct subgenera; unless all
three should be included as sections of Poteriocrinus.

SCAPHIOCRINUS DECADACTYLUS, M. and W.
Pl. 17, Fig. 6.

Poteriocrinus (Scaphiocrinus) decadactylus, Munk and WortuHEn, Sept., 1860. Proceed.
Acad. Nat. Sci., Philad., p. 394.

Bopy rather small, broad obconical below the second radial
pieces, expanding somewhat rapidly from the base; plates
rather thick, and nearly or quite smooth; sutures between the
first and second radial plates, and between the second radials
and the first arm-pieces, gaping. Base small, convex, or about
half as high as wide, pentagonal in outline, as seen from below.

‘ti
a
~
%
&
4

INVERTEBRATES. 239

Subradial plates somewhat unequal, a little wider than long,
four of them apparently hexagonal, and one on the anal side
heptagonal. First radial plates about twice as large as the
smaller of the subradials, hexagonal in form, and all wider
than long, the upper horizontally truncated side being longer
than either of the others. Second radials about the size of the
first, pentagonal, a little wider than high, truncated below, and -

“provided with a salient angle in the middle above, all rounded

on the outer side, and a little concave on each short lateral
margin.

First anal plate rather large, or equaling some of the sub-
radials in size; irregularly pentagonal or hexagonal in form,
and resting between the superior sloping sides of two of the
subradials; supporting on its right sloping side an inferior edge
of one of the first radial pieces, while it supports two smaller
pieces in the second range, the exact os of which cannot be
made out in our specimen.

Arms long, robust, subcylindrical, rather unequal in size,
and apparently all simple after the division on the second
radials, entirely composed of a single series of pieces, a few of
the first of which are longer than wide, and alternately longer
and shorter on opposite sides; farther up they become more
regular, and shorter than wide. Column rather small, or less
than the diameter of the largest arms, round, and composed of
thin, slightly unequal segments, near the body. Its central
cavity small, and presenting a regular pentapetalous section.
Height of body to the summit of the second radials, about 0.50
inch; breadth near fhe same. Length of arms apparently not
less than 2.50 inches; breadth of do., from 11 to 0.16 inch.

240 PALEONTOLOGY OF ILLINOIS.

Fig. 25. This species, like Scaphiocrinus simplex of Hall, (Jowa

— Report, vol. I, p. 551) differs in being more robust, and in
having a more projecting base, while its arms are stouter

and composed of comparatively shorter and less distinctly

wedge-formed pieces, which show no lateral projections for

AG the support of the tentacles. Again it differs in having its
as first anal piece alternating with two of the subradials, in-
cs stead of resting upon a truncated upper side of one of them.
Doce (\ Locality and position: Appanoose, Hancock county,
) O _ Ill.; Keokuk limestone of Lower Carboniferous series.

Poteriocrinus decadacty-
us. (Nat. size.)

Diagram showing the
form and arrangement
of the basal, subradial,
first primary radial and
anal pieces, with the sec-
ond primary radial, and
portions of the arms of
the anterior ray.

Genus ZEACRINUS, Troost. (See page 185.)

ZEACRINUS PLANOBRACHIATUS, M. and W.
Pl. 18, fig. 5.

Zeacrinus planobrachiatus, MnrK and WorTHEN, Sept., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 391.

Bopy small, depressed basin-shaped below the summit of the
first radials, concave beneath ; composed of apparently smooth
plates, connected by moderately distinct sutures. Base small,
concave, and apparently nearly hidden by the column. Sub-
radial pieces as wide as long, or a little wider, four of them
hexagonal, and one on the anal side heptagonal, (counting
three angles at the base of each). First radial pieces wider
than long, expanding upwards from the base, apparently all
pentagonal, the upper side being horizontally truncated, and
longer than either of the others. Second radial pieces nearly
as large as the first, presenting (in the posterior and lateral

INVERTEBRATES. 241

rays) a triangular outline, the lateral angles being probably
sometimes truncated. First anal plate narrow below, and
wedged down obliquely between one of the subradials and an
inferior sloping side of one of the first radials ; supporting one
or two smaller pieces above, the exact forms of which cannot
be made out in our specimen.

Arms rather flattened on the outside, and after dividing on
the second radial pieces (in those seen), bifurcating again on
the sixth piece; beyond this entirely simple, and each com-
posed of a single series of pieces, which are slightly wider than
long, and a little wedge-shaped, or alternately longer and
shorter on opposite sides. On the long side they project a
little above, for the reception of the tentacles, which are large,
and composed of joints nearly twice as long as wide. Height
to the summit of the second radials, about 0.17 inch; breadth
at the top of the first radials, 0.27 inch; length of arms, from
their division on the second radial pieces, about 0.84 inch.

This species seems to be related to Z. bifurcatus, of McChesney (Descr. New
* Palxozoic Fossils, p. 9, pl. 5, fig. 3), but differs in being less robust, and in hay-
ing proportionally broader subradial pieces, while the upper angle of its second
radials is much more salient, and the pieces between the first and second bifur-
cations of its arms, are more wedge-shaped than is represented in the figure and
diagram of Z, bifurcatus. The arms, or at least some of them. in Prof. McChes-
ney’s species, also bifurcate a third time, while in our species, they are entirely
simple after the second division.

If, as has been suggested by Dr. Shumard and Mr. Lyon, the type of de
Koninck and Lehon’s genus Graphiocrinus, should be found to possess the same
structure as Troost’s Zeacrinus, de Koninck and Lehon’s name, having priority,
will have to take precedence, and the name of this species will have to be written
Graphiocrinus planobrachiatus.

Locality and position: Near south line of Monroe county, Illinois; Keokuk
group, of Subcarboniferous series.

— Bil Supr. 10, 1866,

242 PALEONTOLOGY OF ILLINOIS.

Genus ONYCHOCRINUS, Lyon and Casseday.

Synon.—Onychocrinus, Lyon and Cassrpay, 1859. Am. Journal Sci (2), xxix, p. 77.

Forbesiocrinus (sp.), Haun, 1858; Iowa Report. Meek and Worthen (sp.),
1860; Proceed. Acad. Nat. Sci., Philad.; (not de Koninck and Lehon.)

AtrTHouaH for some time past inclined to regard the type for which the name
Onychocrinus was proposed, probably in no respect distinguishable from Forbes-
docrinus, a careful study and comparison of a number of specimens of these
groups has led us to believe them most probably generically distinct. At any
rate, they certainly differ upon more constant and more clearly defined charac-
ters than those separating Porbesiocrinus from Taxocrinus, which we have else-
where shown,* blend into each other by such imperceptible gradations, that we
we do not believe they can be separated more than subgenerically.

In the nature of the column, the number and arrangement of the basal, sub-
radial and primary radial pieces, Onychocrinus agrees exactly with Forbesiocrinus,
while in other respects the species of the former, particularly the typical species,
differ from those of the latter in some points of structure that impart a peculiar
physiognomy to the whole fossil, quite obvious even to the most careless observer,
in examining entire specimens. In the first place, they differ from Forbesio-
crinus in having the body more depressed, and the rays, from their origin, more
diverging, or in some cases extending out horizontally on the same plane with
the base; while in these extreme cases the long rays, which are free in to the

second radials inclusive, bear the small arms in clusters at their extremities,
remote from the body. In short, if we could open and spread out the rays of
a Forbesiocrinus upon a plane as far in as to the second radial pieces, and then
divide each of the interradial series of plates, and fold them up so as to cover
the vault, and apparently to some extent the free rays, somewhat in the manner
suggested by Prof. Agassiz for the ideal conversion of an Echinoid into a star-
fish, we would have a form very like the extreme Onychocrinus. Still there
would be this difference, however, that in Onychocrinus the anal series of plates
is almost entirely wanting, and the anal area open and so deeply excavated as
often to completely destroy the symmetry of the body. That is, instead of
having the anal area occupied by as many pieces as, or a greater number than,
occupy the interradial areas, as in Forbesiocrinus, we find the whole anal series
in Onychocrinus, whatever may be the number of interradials, reduced to a few
very small pieces, ranged in a direct line, one upon another, and resting with
the first or lowest one in a small sinus in the middle of the upper side of the
large odd subradial, much as the arms of Platycrinus rest upon the first radials,

‘
4

{.
;

* Proceedings Academy Natural Science, Philadelphia, August, 1865, p. 138.

INVERTEBRATES. 243

and really looking very much like a diminutive arm rising from the middle of
the anal area. This arm-like range of small pieces seems never to consist of
more than from four to six or seven pieces, which are so small and narrow as to
leave a wide, free, open space between them and the posterior rays on each side,
as seen in our figure of Onychocrinus monroensis, plate 17, figure 7. How they
connect with the vault we have never been ahle to make out, as they are always
entirely disconnected from all other parts, excepting the subradial upon which
they rest. We suspect, however, that they merely formed the outside of a
small lateral proboscis, the inner side of which was composed of a soft, dermal
integument, connecting with the yault.

This peculiarity of the anal side has been entirely overlooked, or misunder-
stood in the species of this type referred to Forbesiocrinus, the impression being
that the anal plates had been, by some accident, removed from their place. It
is true, we had observed that the anal area in our Porbesiocrinus monroensis and
F, Norwoodi, which belong to this group (though not extreme examples of it),
is only occupied by a slender little finger-like appendage, resting upon the upper
side of the odd subradial; but as stated in our description of the former species,
we supposed the anal plates had been broken out, and that this little round,
finger-like appendage, occupying their place, was one of the smaller divisions
of the arms that had been accidentally placed in that position, in the only speci-
men of each of these species then known. Lyon and Casseday had, however,
correctly described these as the anal pieces of Onychocrinus.

We have seen this character well defined in the following species, viz: For-
besiocrinus asterixformis, F. Whitfieldi and F. Meeki, of Hall; and in our F.
monroensis, F. Norwoodi and O. diversus, as well as in Lyon and Casseday’s
typical species. In the type of the species F. Meeki, now before us, the anal
area, as may be seen by the figure in the Lowa Report, is entirely open, and
even without the little finger-like appendage, which was broken out. In five
other individuals, however, of this species we have seen, this character is un-
mistakably visible, and we have never seen a specimen of either this or any of
the other species mentioned above, with the anal side filled with plates as in
Forbesiocrinus.

From all the facts now known, we therefore incline to the opinion that these
forms should be separated from Forbestocrinus, under the name Onychocrinus.
It is worthy of note, however, that this group seems to be even farther divisi-
ble into two rather distinct sections, upon characters the exact value of which
we cannot satisfactorily determine without knowing more about the vault and
upper side of these species. For instance, O. asterixeformis=(Forbesiocrinus
asterizformis, Hall), and our O. diversus, which are the extreme forms already
referred to, differ from the other species mentioned, in having the rays more
spreading, and free in as far as to the second or first primary radials, instead

244 PALEONTOLOGY OF ILLINOIS.

of being connected by many interradials, as in the other species, while their
arms, which are proportionally small, are clustered together in little bunches
at the extremities of the rays, far out from the body.

These last mentioned species, with their long spreading and bifurcating rays,
bearing their numerous clusters of little, curled-up arms at their extremities,
must have presented much the appgarance of dried examples of the existing genus
Astrophyton, though we cannot agree with Messrs. Lyon and Casseday, in the
opinion that they form a connecting link between the Crinoidea and Asteroidea,
or are more nearly allied to the star fishes than other palzeozoic crinoids, their
resemblance being merely simulative, and not due to any close analogy of struc-
ture.

The species of this group yet known to us, are confined to the Subcarbonif-
erous rocks, and seem to be peculiar to America.

ONYCHOCRINUS MONROENSIS, M. and W.

Pl. 17, Fig. 7.
&
Forbesiocrinus monroensis, MpEK and WorTHEN, June, 1861. Proceed. Acad. Nat. Sci.,
Philad., p. 130.

Bopy below the free arms apparently depressed basin-shaped,
composed of nearly smooth rather thick plates, connected by
linear sutures. Base small, and nearly hidden by the column.
Subradial plates of moderate size, four of them pentagonal,
and one on the anal side hexagonal, with unequal sides—its
upper side being short, and distinctly sinuous in the middle,
for the reception of the small first anal piece. First radials.
about twice as wide as high, hexagonal in form, and nearly
twice as large as the subradials. Second, third and fourth
radials in two of the rays (and one or two more in another),
all nearly of the same length, hexagonal in form (excepting
those on the two posterior rays, which have their ends next
the anal space truncated so as to become pentagonal), and all
nearly twice as wide as long. Last primary radial pieces
smaller than the others, pentagonal, and supporting on their
superior sloping sides the abruptly diverging first divisions,
each of which latter gives out several branches above.

INVERTEBRATES. : 245

Of the interradials, the first is about the size of the subra-
dials, hexagonal in form, and supports two smaller ones in the
next range. Above the latter the rays diverge considerably,
and it is evident there was at least a single row of small pieces
fitting into the notches between the ends of the primary radials,
but whether these curved up and connected with the vault, or
whether they connected with others filling the whole interra-
dial space between, our specimen is too imperfect to enable us
to determine, though we think the former was the case.

Anal pieces, seven or eight known, very small, and showing
the peculiarity characterizing the group very clearly, the whole
range forming a little finger-like appendage about the size of
one of the smaller divisions of the arms.

Column rounded and comparatively thick at its junction with
the base, from which it tapers gradually towards the lower
extremity; near the base composed of extremely thin equal seg-
ments, connecting by crenulated sutures, the crenulations being
formed apparently by radiating striee on the surfaces of the seg-
ments; farther down it gradually passes into a series of alter-
nately thicker and thinner pieces.

Locality and position: Keokuk division of Subcarboniferous séries; on the
river bluffs, near south line of Monroe county, Illinois.

OnycHocrinus Norwoopi, M. and W.
Pl. 17, fig.\3.

Forbesiocrinus 2? Norwoodi, Menx and WorrueEn, Sept., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 389.

Laxocrinus Norwoodi, Munk and Wortuen, Aug., 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 142.

Comp. Onychocrinus exculptus, Lyon and Cassrpay, 1859. Am. Jour. Sci. xxix, p. 78.

Bopy below the last primary radial pieces, apparently short
obeonical, or expanding rather abruptly and regularly upwards
from the base; composed of nearly smooth, thick plates, con-
nected by linear sutures. Base small, consisting of very low,

246 ; PALAONTOLOGY OF ILLINOIS.

unequal pieces, which do not project out beyond the cireum-
ference of the upper extremity of the column. Subradial
plates irregular in form and size, one of them apparently
quadrangular, two pentagonal, one hexagonal, and one hepta-
gonal, or octagonal. First radial pieces nearly twice as wide
as long, two of them heptagonal, two hexagonal, and one
apparently pentagonal; all more or less arcuate laterally ;
second, third and fourth radials (also the fifth in the anterior
ray) not differing greatly in size, wider than long, and hexa-
gonal in form. Fifth radials (sixth in the anterior ray) of the
nearly same size as the others, heptagonal in form, and sup-
porting on their sloping sides the secondary radials.

First interradials nearly half as large as the first radial
plates, heptagonal and hexagonal in form, and each supporting
two or three smaller pieces in the second range; above these,
three or four pieces are seen in the next range, which is as far
up as they can be counted in the specimen before us, though it is

probable the number increased at the same rate for several -

ranges above. Anal pieces unknown, excepting the base of
the first one, which is very small, and as usual in this group,
rests in a.sinus in the upper side of the large odd subradial
piece; secondary radials above the first divisions of the rays on
the fifth and sixth primary radial pieces, continued nearly on
a line with the primary radials below, without diverging so as
to leave any room for interaxillary pieces. In one of the poste-
rior rays seen, a second bifurcation takes place on the fourth
piece, beyond which the pieces in this ray are not preserved in
our specimen.

Column round, comparatively thick at its connection with
the base, from which it tapers towards the lower extremity;
composed of extremely thin segments, fitting together by inter-
locking crenulations formed by the radiating striae; its central
cavity subcircular, or obscurely pentagonal, and about one-
third as broad as the transverse diameter of the column.

eng te ’ 2s _

INVERTEBRATES. ' 247

The specific name was given in honor of Prof. J. G. Nor-
wood, of the University of Missouri.

This species will be distinguished from the last, not only by its larger size,
and more robust habit, but particularly by having the two divisions of each

Fig. 26. ray, after they divide on the
last primary radial, continu-
ed on for some distance,
closely united, instead of ab-
ruptly diverging. Its sub-
radial plates also appear to
be widely different, though
they seem to be somewhat
abnormal in their form, in
the specimen from which our
diagram is made out.

Since seeing a specimen
of Onychocrinus exculptus, of
Lyon and Casseday, sent on
to the Chicago Academy of
Sciences, by Mr. Lyon, we

=
Onychocrinus Norwoodi. (Nat. size.) suspect that the form under

This diagram shows the subradial, radial and some of the . :
interradial pieces, as they appear to be arranged ina distorted consideration may prove to
peeuneDs with the radial series out a little beyond the first bi- be a variety of the same.

Yet as it presents a greater irregularity in the size and form of the subradial
pieces, and some differences in the form of the first radials, we have concluded to
retain our name until we can have an opportunity to compare better specimens.

Locality and position: River bluff near the south line of Monroe county,
Illinois; Keokuk division of the Lower Carboniferous series.

ECHINOIDEA
PERISCHOECHINIDA. (See page 225.)
_ Genus OLIGOPORUS, M. and W.

- (odtvoc, few ; zopoc, a passage.)
Synon.—Melonites (sp.), Marx and Worruen, Sept., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 397; (not Owen and Norwood, 1846).
Oligoporus, Manx and Wortuen, Sept., 1860. Proc. Acad. Nat. Sci., Philad., p. 474.
THE specimen upon which this genus was founded, consists
of two of the ambulacral series, and one entire intervening

248 PALMONTOLOGY OF ILLINOIS.

series of interambulacral plates, all in very nearly their natu-
ral position, excepting that the specimen is somewhat flattened
by pressure. We at first referred it to the genus Melonites, but
subsequently proposed to separate it, at least subgenerically, —
from the type of that genus, and later comparisons now lead —
us to regard it as generally distinct. So far as its characters
can be made out, it seems to agree almost exactly with Jelon-
ites in size, form, the number and thickness, as well as the ~
arrangement of its interambulacral plates, and in the breadth —
and deeply double furrowed character of its ambulacra. It
differs, however, in the important peculiarity of having only
four rows of ambulacral plates, and four double rows of pores,
Fig. 27. to each ambulacrum, in-
a stead of about ten of
each. This difference
will be more clearly un-
derstood by comparing
_ Melonites multipora. (Two diameters ) the annexed cuts—No.
_Diagram showing the number and arrangement of the Of representing the num-
DO ae oe Sk esa utes aaree oe eon al Wore ee eis) Pal Seas.
near the middle of the ambulacral area. ge
3h ment of the plates and pores
in the ambulacra of DMelonites
multipora, and the cut No. 28
the same in Oligoporus Dane,
both from near the middle of
the ambulacral series. Be-
Chit CS lieving that this peculiarity in
aris rior rs the form under consideration
a Gat EROreanIaGea aoe ynearthemid-myst have been accompanied
by other equally important differences in the apical disc, and
the structure of the softer parts of the animal, we can but
regard it, with our present means of comparison, as the type
of a distinct genus.
It will thus be seen that the type of Oligoporus seems to be ¢
almost exactly intermediate, in some of its characters, between :

INVERTEBRATES. — 249

Melonites and Palechinus ; the number of its ambulacral plates
and pores being .only half as great as in the former, and double
that of the latter. It evidently approximates Melonites more
nearly, however, in having its ambulacra deeply furrowed, so
as to impart the same melon-like form to the whole outline,
that suggested the name Melonites. It also agrees more nearly
with the latter genus, in the greater comparative breadth of its
ambulacra, which are about half as wide in the middle as the
interambulacral areas, while those of Palechimus are only from.
one-fifth to one-seventh as wide as the interambulacral spaces.

It is barely possible that future discoveries may bring to light other inter-
mediate forms, connecting Melonites and Palechinus, through Oligoporus, by
such gradations as to render it necessary to include the whole as sections of one
genus. -

When used as a generic name, Oligoporus is less appropriate for this type than
when it is placed as a subgeneric name under Melonites, since it has more pores
than any other known type of the suborder, excepting Melonites. Another
objection to it is, that Desor had used thé name Oligopores, in 1858, for
a section of the Cidaride. As Oligopores, however, from its termination,
is sufficiently distinct, and many quite as unappropriate names are retained in
other departments of Natural History, we scarcely think it desirable to make a
change. If others should think differently, however, it may be called
Melonopsis. ;

Oxicororus Dana#, M. and W.

Pl. 17, Fig. 8

Melonites Dane, Mrrx and WortHEn, September, 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 397. .

Oligoporus, Mrrx and WorTHEN, 1860. Ib., p. 474.

Large, subglobose, or depressed ovoid. Interambulacral
areas lance-ovate in outline, moderately convex, occupied below
the middle by nine vertical ranges of plates, near the middle
by eight, a little higher by seven, and thus decreasing in num-
ber to four ranges at the highest point to which they can be

5, Serr, 11, 1866.

250 | PALHONTOLOGY OF ILLINOIS.

traced in our specimen; the two outer rows of pentagonal —
pieces continuous, while four of the intermediate rows of hexa-_

gonal plates* terminate before reaching either extremity.

Ambulacral areas: half as wide as the interambulacral spaces, a

and nearly as convex in the middle; while their broad furrow
on each side of this mesial ridge is as deep as those of Melonites

multipora. Ambulacral pieces somewhat a@rregular, in conse-_

quence of the intercalation of a few supplementary pieces,

all wider than high, the breadth being from one and a half to ~

seven times the height; those of the inner two rows a little
wider than the outer two, and more irregular in form;
usually from three to five of those of the outer two ranges occu-
pying the vertical space of each contiguous interambulacral

plate; intercalated pieces-apparently always between those of

the middle two ranges, but rarely extending into the mesial

zigzag sutures. Ambulacral pores circular, two to each piece,

and so arranged as to form four vertical ranges, the outer two
ranges being more or less zigzag.

Entire surface occupied by regularly disposed eranules, evi-
déntly the bases of small spines. Of these granules, about
twenty-five may be counted on each of the larger interambu-
lacral plates, and as many, in proportion to size, on each of the

-smaller ones, including the ambulacral pieces.

Our specimen is too imperfect to give exact measurements, but it indicates a
height of about 4 inches, and a breadth of probably from 34 to 4 inches below
the middle. The greatest breadth of the interambulacral space is about 14
inches, while the interambulacral plates agree in size and form with those of
Melonites multipora.

Specifically this form will be at once distinguished from Melonites multipora,
even in fragments, where the arrangement of the afnbulacral plates can be
seen, by their being but four ranges of these pieces, instead of twice that num-

(See cut on p. 248.) It also seems to have differed in form somewhat,
being apparently proportionally broader below the middle than above.

* The terminal plate of these intermediate rows, usually differs from the others in
being pentagonal, but not from the truncation of one side, like those of the marginal
rows, on each side of the ambulacra. é

re

INVERTEBRATES. Zo

Should future discoveries prove this type to be only one of a series connect-
ing Palchinus and Melonites as sections of one genus, its name would become
Palechinus Danz, since Palzchinus has priority-over either of the other names.

Locality and position: Jersey county, Illinois. Keokuk division of the
Subcarboniferous series. Also at Warsaw, Illinois, at same horizon. We have
likewise seen a specimen of apparently the same species, in Dr. Shumard’s col-
lection, from Fenton, St. Louis county, Missouri.

MOLLUSCA.

BRACHIOPODA.
Genus CAMAROPHORIA, King, 1844.

(Ann. and Mag. Nat. Hist., vol. xiv.)

CAMAROPHORIA SUBTRIGONA, M. and W.
Pl. 18, Fig. 8a, 8b, 8¢.
Rhynchonella subtrigona, Merx and WortueEn, Oct., 1860. Preceed. Acad. Nat. Sci.,

Philad., p. 451.

‘Rhynchonella Parvini, McCumsney, Feb., 1861. New sp. Fossils from Paleozoic rocks
of the Western States, p. 83; also, 1865, Illustrations of ditto, plate 6, figure 2.

Compare Atrypa isoryncha, McCoy, 1844. Carboniferous Fossils, Ireland, p. 154;—=
Camaropharia isoryncha, McCoy, 1852. British Pal. Foss., p. 444; Davidson’s Brit-
ish Carboniferous Brachiopoda, p. 117, pl. xxv, figs. 1 and 2, 2a and 26. -

SHELL rather above medium size, trigonal-subglobose, wider
than long, usually gibbous, truncated in front and on each
postero-lateral slope; anterior margins of the valves sharply
and deeply serrated; posterior lateral slopes each forming a
flattened or concave oval space, without well defined plications,
and limited by a more or less distinct angle on each valve.
Ventral vakve nearly flat, or arching a little from the umbo
along the middle towards the front, on each side of which the
antero-lateral margins are-at first elevated, then very abruptly
deflected towards the other valve; front curving down nearly
at right angles to the plane of the valve, and extended so as to

_ 252 PALHONTOLOGY OF ILLINOIS.

fill a broad, deep, rather rounded sinus in front of the other

valve; postero-lateral margins also abruptly deflected to meet
those of the opposite valve; beak small, rather pointed, in-

curved upon that of the ventral valve ; mesial sinus very broad,

shallow, and not distinctly defined. Dorsal valve much more
gibbous than the other, the most convex part being in the
antero-central region, thence sloping with a moderately convex

. outline to the beak ; lateral and antero-lateral margins abruptly

curved to meet those of the opposite valve; mesial elevation
not well defined, rather flattened, and scarcely traceable to the
middle. Surface of each valve ornamented by from about
fourteen to eighteen rather rounded, or sometimes obtusely
angular plications, which are defined to the beaks; four to six
of these plications usually occupy the mesial sinus, and about
the same number the mesial elevation. Fine, obscure, concen-
tric striae are also seen on well preserved specimens. Length
of a medium sized, rather gibbous specimen, 0.90 inch; breadth,
0.98 inch; convexity, 0.91 inch.

At the time we published a description of this species, under the name.

Rhynchonella subtrigona, we had not access to Prof. McCoy’s work on the Car-
boniferous Fossils of Ireland, nor had we received Mr. Davidson’s valuable
Monograph of the British Carboniferous Brachiopoda. Since seeing these
works, we are strongly inclined to think our shell identical with Camarophoria
isoryncha of McCoy. Gibbous specimens of it certainly resemble very closely
the figures of th species given by these authors. A large majority of the
specimens, however, are less gibbous, while they all have the front more flat-
tened at right angles to the plane of the valves, and the sinus and anterior
projection of the ventral valve, broader. As it is not possible to determine,
from the few figures yet published of the C. dsoryncha, the extent of its varia-
tions in these characters, we do not feel quite warranted in referring our shell
to that species.

All of the five other specimens we have had for comparison, afe less gibbous ~

and proportionally broader than the one we have figured, though one of them
is considerably larger and none of them are smaller. On grinding across the
beaks of one of these specimens, we find that it shows very satisfactorily the
internal characters of the genus Camarophoria. ry

INVERTEBRATES. j 253

The specimen figured by Prof. McChesney, under the name Rhynchonella
Parvini, seems not to have been in a condition to show very satisfactorily the
characters of the species, being merely disunited valves, though his description
agrees exactly with the specimens before us, which fact, taken in connection

__with the locality and position, leaves little room for doubt in regard to its

identity with our shell. We may also add, that Prof. McChesney, on seeing
our specimens, identified them with his R. Rarvini.

Locality and position: Keokuk, Iowa; Nauvoo and Warsaw, Illinois, etc.;
_ Keokuk division of the Subcarboniferous series.

Genus CHONETES, Fischer, 1837.

(Oryctogr. Mosc., p. 134.)

CHONETES PLANUMBONA, M. and W.

Pl. 18, figs. la, 16, le, 1d.

Chonetes planumbona, MEEK and WorruHeEN, Oct., 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 450.

SHELL of medium size, nearly semicircular; length from two-
thirds to three-fourths the breadth ; hinge line usually a little
longer than the greatest breadth of the valves at any point
farther forward; front rounded, er forming, with the sides, a
nearly semicircular curve; lateral margins intersecting the
hinge at generally less than a right angle. Ventral valve
usually moderately gibbous, flattened at the umbo, most convex
near the middle, and sloping down to the sides and front—
destitute of any traces of a mesial sinus; ears a little com-
pressed ; cardinal margin sloping very slightly from the beak
to the extremities, armed with some eight or ten oblique spines
(only known from small remaining bases); area of moderate
breadth ; foramen rather broad-triangular, the upper angle
being a little rounded; beak not incurved. Dorsal valve con-
cave, or following nearly the curve of the other valve; cardinal
process moderately prominent, nearly or quite closing the
foramen of the opposite valve; interior without a prominent

¥ ‘ ™

254 ’ PALEONTOLOGY OF ILLINOIS.

mesial ridge, more or less granular, the granules being often
arranged in radiating lines ; visceral scar rather large ; impres-
sions of adductor muscles small and not very deep. Surface
of both valves, to the unassisted eye, apparently smooth, but
showing, under a lens, nearly obsolete traces of radiating strie,
crossed by minute concentric lines or wrinkles. - Length, 0.42
inch; breadth, 0.49 inch; convexity, 0.16 inch.

This species seems to be more nearly allied to C. polita of McCoy (Brit. Pal.
Foss., p. 456, pl. 3D, fig. 30), than any other Carboniferous species of the genus
with which we are acquainted. It differs, however, in its larger size and more
flattened "umbo, as well as in showing no traces of the two prominent ridges in
the interior of the dorsal valve, mentioned in Mr. Davidson’s description
of that species (Brit. Carb. Brach.). It also shows, on well preserved speci-
mens, faint traces of moderately coarse radiating striz, and none of the spine
bases over the surface of the ventral valve, figured by Mr. Davidson.

Locality and position: Monroe county, Illinois; Keokuk division of the
Lower Carboniferous series.

.

Genus ATHYRIS, McCoy, 1844.*

(Carb. Foss. Ireland, p. 146.)

ATHYRIS PLANOSULCATA, Phillips? (sp.)

Pl. 22, fig. 8a, 8b, 8c, 8d.

Spirifer planosulcatus, Puinuies, 1836. Geol. Yorksh., vol. ii, p. 220, pl. x, fig. 15.
Atrypa planosulcata, Soworsy, 1840. Min. Conch., vol. vii, p. 15, pl. pexvii, fig.2.
Atrypa oblonga, Ibid, fig. 3. ;

Atrypa planosulcata, Dr Konincx, 1843. An. Foss., p. 301, pl. xxi, fig. land 2.
Actinoconchus paradoxus, McCoy, 1844. Synop. Carb. Foss., p. 150, pl. xxi, fig. 6.
Atrypa obtusa, McCoy, Ibid., pl. xxii, fig. 20.

Athyris paradoxza, McCoy, 1855. Brit. Pal. Foss., p. 436.

Athyris parvirostris, Mnnx and WortHEn, Oct. 1860. Pro. Acad. Nat. Sci. Phil., p. 451.

SHELL of medium size, quadrate-subcircular, moderately

gibbous, length and breadth nearly equal, sometimes a little.

* It is probable d’Orbigny’s later name Spirigera will be retained for this genus;
Athyris implying a plain contradiction of fact, since the beak is perforated.

INVERTEBRATES. 255

wider than long, (other examples a little longer than wide);
ereatest convexity at the middle; valves equally gibbous;
lateral margins usually prominent and narrowly rounded in
outline at the middle, thence converging with a slightly con-
vex outline to the faintly subtruncate front; postero-laterat
margins a little inflected, so as to form slighteconcavities, con-
verging to the beaks at an angle of about 97°. Both valves
destitute of a mesial fold or sinus, but each sometimes slightly
flattened in the middle near the front, where they meet with-

out the slightest sinuosity in the margin of either. Beak of

ventral valve small, pointed, closely incurved upon that of the
other valve, which is but little less prominent, foramen round
and very small. Surface with small, obscure, concentric marks
of growth. Spiral appendages each making about twelve
turns. Surface (probably exfoliated) showing only small,
obscure, concentric ridges. Breadth-of a rather wide specimen,
0.84 inch; length of do., about 0.77 inch ; convexity, 0.52 inch.

Since publishing a description of this form under the name of Athyris par-
virostris, in the proceedings of the Philadelphia Academy of Sciences, further
comparisons with some additional specimens, lead us to think it most probably
only a variety of A. planosulcata, of Phillips, to which we now refer it provis-

jonally. Nearly all the specimens we have yet seen, however, differ from the

figures, as well as from authentic English examples of Phillips’ species, with
which we have compared them, in being much less nearly circular, or more
nearly subquadrate in“outline. Possibly a more extensive series of specimens
may prove it entitled to rank as a distinct species, but with our present means
of judging, we incline to the opinion that the differences observable, are not of
specific value. :

None of the specimens we have seen show the projecting, concentric lamellz
of growth so characteristic of the A. planosulcata ;*though as they were all
broken from a hard limestone; and seem to have lost-the outer layers of the
shell, we could scarcely expect any traces of the projecting lamille to be retain-
ed under such circumstances. Hence their absence is no evidence that they
may not have existed.

Locality and position: Keokuk division of Subcarboniferous series; near War-
saw, Illinois.

256 PALEONTOLOGY OF ILLINOIS. -

LAMELLIBRANCHIATA.
Genus AVICULOPECTEN, McCoy, 1851.

(Ann. Mag. Nat. Hist., vol. vii, p. 171.)
Lad
AVICULOPECTEN OwENI, M. and W.

Pl. 18, fig..2 a, 20, 2¢.

Aviculopecten Oweni, Merk and WortHEN, Oct., 1860. Proceed. Acad. Nat. Sci., Phil-

adelphia, p. 452.

SHELL small, truncato-subcircular; base regularly rounded ;
posterior margin rounding from above the middle to the ventral
border; anterior side rounded below; hinge equaling about
two-thirds the diameter of the valves from the posterior to the |
anterior side, ranging at right angles to longer axis of the shell.
Left valve moderately convex; anterior ear compressed, sepa-
rated from the swell of the umbo by a rounded, shallow
depression, and defined by a shallow sinuosity in the anterior
margin; having the form of an inequilateral triangle, the ante-
rior side of which is shorter than either of the others, very —
slightly rounded at the nearly rectangular extremity; posterior -
ear a little smaller than the other, compressed, very short, not
separated from the margin below by a distinct sinus, termina-
ting in an obtuse angle of about 100°; umbo rather convex,
located apparently a little behind the middle of the hinge;
surface ornamented by numerous, fine, closely arranged, radia-
ting strize, which increase by implantation, and are crossed by
a few irregular marks of growth. (Right valve unknown.)
Diameter from the ventral margin to the hinge, 0.48 inch; do.
from the anterior to the posterior margin, 0.50 inch; length
of hinge, 0.35 inch. Number of striz in 0.10 inch near the
ventral margin, about 13.

Locality and position: Keokuk division, Subcarboniferous series, near War-
saw, Illinois.

INVERTEBRATES. 2a

AVICULOPECTEN AMPLUS, M. and W.

Pl. 18, Fig. 4a, 48, 4c.

Aviculopecten amplus, Munk and WorTHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 454. .

SHELL large, subcircular, rather thin, not oblique; length
and breadth about equal; ventral and lateral margins regularly
rounded; hinge line straight, less than the breadth of the
shell. Ligament area broad, distinctly striated longitudinally ;
that of the right valve inclining back from the hinge, and the
other overhanging it. Muscular impression large, obliquely
subrhombic, concave in outline above, and convex below; loca-
ted above and behind the middle.

Left valve convex, particularly in the umbonal region; pos-
terior ear very short, nearly rectangular, sometimes very
slightly sinuous on the margin, not very distinct from the
swell of the umbo; anterior ear subtrigonal, angular at the
extremity, and defined by a deep subangular sinus in the mar-
gin below—separated from the swell of the umbo by a more or
less distinct, rounded sulcus or depression. Beak gibbous, in-
curved, and extended slightly beyond the hinge margin. Sur-
face ornamented by distinct, narrow, obscurely subnodose, radi-
ating costz, separated by spaces from five to seven times their
own breadth, in which a few much smaller cost ‘or radiating
lines are sometimes seen; crossing the whole are numerous
small, irregular concentric wrinkles, and rather obscure lines
of growth.

Right valve. flat, or concave; posterior ear very small, some-
times obsolete, and in other specimens separated from the mar
gin below by a very slight sinuosity; anterior ear oblong,
rounded at the extremity, and separated from the margin be-
low by a very profound, acutely angular byssal sinus; umbo
entirely obsolete. Surface nearly smooth, or marked with

very obscure concentric wrinkles, and faint traces of radiating
ae Szpr. 12, 1866.

258 - - PALAONTOLOGY OF ILLINOIS.

strie. In some specimens the anterior ear is ornamented with
a few rather distinct radiating plications, crossed by smaller
subimbricating marks of growth. Length, 3.63 inches; breadth
from the anterior to the posterior margin, about 3.64 inches;
convexity of left valve, near 0.70 inch; length of hinge, about
2.48 inches. Some imperfect specimens in the collection mea-
sure as much as 9.50 inches in diameter.

In the very distinct inequality of its valves, and the comparatively small size
of its posterior ear, as well as in some other characters, this fine species seems
to differ from the typical forms of Aviculopecten, being in these respects more
like Lumicrotis. It differs, however, from this group, in possessing a well de-
fined anterior ear, in the left valve, and a ligament area, without any carti-
lage pit or impression, as well as in having a merely laminated, instead of a pris-
matic structure.* It is probably related to a shell figured by McCoy, under the
name Malleus orbicularis, in his Carb. Foss. Ireland, pl. xix, fig. 2, though clearly
distinct specifically. Of course that excellent palzeontologist would not now
refer such a shell to Malleus.

The specimens we have figured are not in a condition to show the muscular
impression, but we have indicated its position, form, etc., from others by the
dotted line in fig. 4c, pl. 18. The left valve, judging from some imperfect
specimens before us, is in some individuals proportionally more convex than
in that from which our measurements were taken.

It is probable that Avicula magna, of Prof. Swallow, described in the Trans.
St. Low's Acad. of Sci., vol. ii, p. 98 (1862), is synonymous with this species.

Locality and position: Monroe county, Illinois. Keokuk division of the
Subcarboniferous series. |

AYVICULOPECTEN OBLONGUS, M. and W.

Pl. 18, fig. 3a,°3.

Avicula oblonga, Mnnx and Wortnen, October, 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 454.

SHELL small, nearly semicircular, moderately oblique; hinge
straight, and longer than any other part of the shell; pallial
margin broadly rounded; postero-ventral region more promi-

* See American Journal of Science, xxxvii (second ser.), p. 218, and Palzont. Upper
Missouri, p. 50, 1865.

4
€
a

INVERTEBRATES. 259

nent than towards the front. Left valve moderately convex ;
anterior ear small, compressed, separated from the swell of the
umbo by a rounded depression, nearly rectangular, or some-
times defined by a very faint sinuosity in the margin below ;
posterior ear larger than the other, compressed, but not very
distinct from the umbonal slope, extending out into an acute
point beyond the posterior margin below, from which it is
separated by a broad rounded sinus; beak small, pointed,
slightly oblique, incurved, and extending a little beyond the
hinge margin; surface ornamented by about twenty-six simple,
sharply elevated, linear, radiating costae, separated at the mid-
dle of the valves, by spaces from three to five times their own
breadth, and crossed by similar regufarly disposed concentric
lines, so as to form a rather regular, coarsely cancellated style
of ornament. (Right valve unknown.) Diameter, from the
hinge to the ventral margin, 0.39; breadth, from the anterior
to the posterior side, 0.52 inch; length of hinge, 0.58 inch;
convex of left valve, about 0.07 inch.

In size and general appearance, this species seems to be not unlike Avicula
radiata of Phillips (Geol. Yorksh., ii, pl. vi, fig. 1), though it has its anterior
wing much broader, less acutely angular, and not defined by a distinct margi-
nal sinus. Unfortunately, however, Phillips’s very brief and unsatisfactory
description aids but little in making the comparison.

_ As we know nothing of the hinge and interior of this shell, we place it pro-
yisionally in the genus Aviculopecten, to which it most probably belongs.

Locality and position: Warsaw, Illinois; Keokuk group. The geological
position of this species was, by an oversight, given as. “ Warsaw Limestone,”
in the paper cited at the head of this description.

260 PALZONTOLOGY OF ILLINOIS.

GASTEROPODA.
Grnus PLEUROTOMARIA, Defrance, 1826.

(Dict. Sci. Nat., vol. xli, p. 381.)

PLEUROTOMARIA SHUMARDI, M. and W.
Pl. 18, fig. 6a, 65.

Pleurotomaria Shumardi, Merk and WortTHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 462.

SHELL trochiform, of medium size, very thin; spire moder-
ately elevated, conical,, somewhat attenuate at the apex.
Volutions about seven, increasing rather rapidly in size,
obliquely flattened above; those of the spire somewhat angu-

_ lar near the lower side; last one very prominent, and angular

around the middle, moderately convex below, the immediate
edge of the angle being truncated by the narrow spiral band.
Band flat or slightly concave, and margined above and below
by a small, smooth, slightly elevated line; passing around a
little above the suture on the whorls of the spire. Suture well
defined; umbilicus small; aperture rhombic-subquadrate, wider
than high. Surface ornamented by numeraus transverse lines,
which are very regular and closely arranged on the upper
whorls, but become stronger, more distant and less regular, on
the last turn. In crossing the upper, flattened, sloping sides
of the whorls, these lines arch a little forward, and pass very
obliquely backwards from the suture to the band; on the under
side of the body whorl, they are smaller or nearly obsolete, and
crossed by obscure traces of fine, revolving striz. Length,
0.70 inch; breadth, 0.73 inch; apical angle rather distinctly
concave ; divergence, 0.70°.

This handsome species is related to P. conica, of Phillips (Geol. Yorkshire,

vol. i, p. 288, pl. 15, fig. 22—1836),. but is a smaller shell, and seems never
to have had so many whorls. Its volutions are also more flattened, both above

INVERTEBRATES. 261

and below, and the last one is more angular around the middle; while its aper-
ture is more depressed and angular than in Phillips’s species. It likewise dif-
fers from that shell in being destitute of a raised line around the upper margin
of the whorls, and in having a small, open umbilicus. The specimen we have
figured is not in a very good condition to show the surface markings. The spe-
cific name was given in honor of Dr. B. F. Shumard, of St. Louis, Mo.

Locality and position: Warsaw, Illinois; Keokuk group, of Subcarboniferous
series.

INVERTEBRATE FOSSILS OF THE ST. LOUIS GROUP.

PROTOZ0O A.
SPONGIAL.
PETROSPONGIA.
Grnus SPHENOPOTERIUM, M. and W. (See page 145.)

SPHENOPOTERIUM CUNEATUM, M. and W.
Pl. 19, fig. 1a, 16, 1¢ and 1d.

Sphenopoterium cuneatum, Muux and WortTHEn, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 448.

COMPRESSED, cuneate, longer than wide; base sharp, a little
rounded at the lateral edges. Cells from two or three to about
five, rather distant, deep, conical, or a little compressed below,
and arranged alternately on each lateral edge; rounded or
slightly oval at the aperture, and directed obliquely outwards
and upwards; often having one or two slightly prominent
ridges extending part of the way up the inside; perforations of
the walls numerous and distinct. Surface strie fine, closely
arranged, rather regularly and minutely crenulated; directed
obliquely inwards and downwards from the apertures of the
cells, and passing more or less nearly parallel to each other, to
the base, on the lower flattened portion. Length, 0.75 inch;
breadth, 0.50 inch; thickness, 0.22 inch. -

INVERTEBRATES. 263

This species will be at once distinguished from all of the others yet known, by
its more compressed elongated form, and the lateral arrangement of its cells,
as well as by the crenulated character of its surface striae.

Locality and position: Spurgen Hill, Indiana; St. Louis group of Lower
Carboniferous series.

RADIATA. "

ECHINODERMATA.
CRINOIDEA.
Genus DICHOCRINUS, Munster. (See page 167.)

Pl. 19, fig. 2a, 26, 2c.

Dichocrinus constrictus, Mrmk and WortHEN, Sept., 1860. Proceed. Acad. Nat, Sci.,
Philad., p. 381. -

Bopy small, oval or obovate, approaching subglobose, rounded
above and below, and rather distinctly constricted just below
the middle, composed of comparatively thick plates, which are
apparently smooth, and joined by linear sutures. Base large,
or forming about one-third of the body, twice as wide as high,
and more or less concave in the middle of the under side; each
of its pieces having five obscure angles above, with very
slightly concave margins between, for the reception of the suc-
ceeding range of plates; columnar facet very small and round.
First radial plates higher than wide, a little unequal, with an
oblong-subquadrangular outline; one of them having a fifth
very obtuse angle at the middle of the under side; sinus in
the upper margin of each, for the reception of the second
radials, rounded, rather shallow, and from one-third to one-
half the breath of the upper side of each plate. Anal piece
slightly larger than the first radials, and like them narrowing
and curving inwards at the summit, subpentagonal in outline.

_ (Other parts unknown.) Length to the top of the first radials,

264. PALMONTOLOGY OF ILLINOIS.

0.38 inch; breadth, above the middle, 0.42 inch; breadth of
base, 0.32 inch; height of do., 0.14 inch.

This species closely resembles Dichocrinus simplex, of Shumard (Trans.
Acad. Sci., St. Louis, vol. 1, pl. 1, fig. 2), being of the same size, and similar
in form, excepting that it is distinctly constricted instead of convex near the
middle, while it is proportionally broader above. It is possible these two forms
may Be only varieties of one species, but as we have not yet seen any interme-
diate gradations between them, we are led: to regard them as-specifically dis-
tinct.

Locality and position: Bloomington, Indiana; St. Louis group of the Lower
Carboniferous series.

Gunus PLATYCRINUS, Miller, 1821. (See p. 170.)

PLATYCRINUS PratTenANvs, M. and W.
Pl, 20, fig. 2,

Platycrinus Prattenanus, Mrex and WortTHEN, Sept., 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 379.

Bopy below the arms, small, cup-shaped, wider than high,
distinctly truncated below by the rather wide, nearly flat col-
umnar facet—expanding gradually with convex sides to the
_ summit of the first radials; composed of comparatively thick,

smooth plates, which (excepting in the base) are connected by
slightly grooved sutures. Base more than one-third as high
_as wide, and provided with a small rim around the margin of
the truncated under side; plates firmly anchylosed, and con-
nected by subcarinate sutures, the carine passing down over
the marginal rim. First radial plates a little wider than high,
quadrangular, nearly as wide below as above, somewhat con-
vex in outline, and provided with a rather broad, rounded sinus
in the upper margin, for the reception of the second radials—
the lower margin of the sinus not projecting on the outer side.
Second radial pieces very small or scarcely more than filling
the depressions in the first, wider than long, triangular, and

INVERTEBRATES. 265

supporting on their concave upper sloping sides the first divi- .
sions of the arms. (Anal and interradial pieces unknown.)
Arms, after the first division on the second radial plate,
bifurcating again on the second piece, and in at least two of
the rays, the inner branch bifurcates again once or twice on the
second piece. Above the last divisions the arms are slender,
nearly cylindrical, and consist of a single series of pieces for a
short distance, then gradually pass into a double alternating
series of small pieces. Tentacles rather thick where they
connect with the arms, but soon tapering, and apparently com-
posed of very long joints. Height of body, to summit of first
radials, 0.35 inch; breadth at the top of the first radials, 0.45
inch; breadth of base, 0.33 inch; height of ditto, 0.13 inch.

This species appears to be rather closely allied to P. Georgii of Hall (Sup.
Jowa Report, p. 82), but has a smaller body in proportion to the size of its arms.
Its first radials also differ in being narrower above, in proportion to their
length, and have a comparatively smaller sinus in the upper margin. Again,
its second radials, and the two succeeding joints of each ray resting upon the
superior sloping sides of these, are proportionally larger. In consequence of
the smaller size of these pieces in P. Georgii, its second radials and the next
range of pieces above, are received within the sinus in the first radials, while in
P. Prattenanus the second radials alone fill these depressions. In both of these
species the column is somewhat compressed and more or less tortuous, but it is

’_ much stronger in P. Georgii, and composed of comparatively thinner pieces.

In comparing our species with Prof. Hall’s description, it is necessary, in
order to have a clear understanding of the relations of these forms, that the
reader should bear in mind the fact that he has inadvertently, or by a typo-
graphical error, described the first radial plates of P. Georgii as the basal
pieces, and the second radials as the first brachials.

Locality and position: Randolph county, Illinois; St. Louis division of the
Lower Carboniferous series.

oe Serr, 13, 1866,

266 PALEONTOLOGY OF ILLINOIS.

‘PLATYCRINUS PENICILLUS, M. and W.

Pl. 19, Fig. 6a, 6b, 6e.

Platycrinus penicillus, Mnrx and WortHEN, Sept., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 380.

Bopy small, cup-shaped below the arms, a little wider than
long, composed of thin plates, connected by moderately distinct
sutures, and ornamented by rather distant granules, which
show a tendency to range in radiating rows on the first radial
plates. Base depressed basin-shaped, considerably wider than
high, and broadly truncated, with a small marginal rim below;
plates firmly anchylosed. First radial pieces nearly flat, and
a little higher than wide, widening somewhat from the base,
subquadrangular, the upper angles being slightly truncated by
the anal and interradial pieces; sinus in the upper margin, for
the reception of the second radial pieces, shallow, and appa-
rently about half as wide as the superior edge. Second radials
small, triangular, wider than long, and supporting on their
upper concave sloping edges the first divisions of the arms.
Anal and interradial pieces unknown.

Arms above the first bifurcation of the second radial pieces,
with the two principal divisions subdivided on the second
piece, and the two middle branches each bifurcating again on
the second piece, beyond which they appear to be all simple, in
the only specimen yet obtained. Immediately above the last
bifurcations, the arms all consist of single series of pieces,
which are alternately longer and shorter on opposite sides;
these pieces become shorter and more wedge-shaped above, and
gradually pass into a double series of small alternating pieces.
The larger single arm-pieces below the bifurcations, and for a
short distance above, are generally longer than wide, narrow
around the middle, and expanded at each end, the superior
lateral angles projecting for the reception of tentacles. All
the tentacles are made up of joints two or three times as long

INVERTEBRATES. 267

as wide. The principal arm-pieces are all connected by pecu-
liar undulating sutures. Column rather strong, and apparently
during the life of the animal, very flexible, rounded near the
body, and composed of thin, alternately larger and smaller seg-
ments, with sharp edges, which are more or less. crenulated;
farther down becoming alternately compressed in opposite
directions, at intervals of about every five joints, while all the
joints increase somewhat in thickness, and are ornamented
by short spine-like projections. About every fifth segment
more prominent on its edges than the others. Length of body,
to the summit of the first radials, about 0.20 inch; breadth,
0.26 inch; length of arms, near 1 inch.

This is an exceeding delicate little species, rather closely allied to a form
we have seen in collections, labeled Platycrinus polydactylus, Troost. It has,
however, a smaller body, and the lower joints of its arms are much more dis-
tinctly constricted around the middle, and more projecting at the joints on
each side.

Locality and position: Hardin county, Iil.; St. Louis division of the Lower
Carboniferous series.

4
PLATYCRINUS PLENUS, M. and W.

Pl. 20, fig. 3. *

Platycrinus plenus, Munk and Wor?uxn, Sept., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 380.

Bopy globose, somewhat wider than high, composed of thin,
slightly granulose plates, connected by linear sutures, except-
ing in the base, where they are anchylosed and carinate. Base
depressed basin-shaped, widening rapidly from the rather small
columnar facet, which is margined by a small rim. First
radials comparatively large, about as high as wide, subquad-
rangular in outline, the two superior lateral angles being rather
distinctly truncated for the reception of the anal and interra-
dial pieces; all regularly incurved above, where they are each

268 PALEONTOLOGY OF ILLINOIS.

provided with a shallow sinus, equaling about half the breadth
of the plate. Second radial pieces very small, near half as
long as wide, and supporting on their superior sloping concave
sides, the first divisions of the arms. Interradial plates com-
paratively large for a species of this genus, and each provided
with a short central spine. “Anal plate unknown.

Arms slender, after the first divisions on the small second
radials, bifureating again on the second piece, and above this
the two inner branches divide once more on the second
piece, making apparently six arms to each ray. All the
divisions of the arms, above the last bifurcation, at first
composed of a single series of wedge-formed pieces, but gradu-
ally passing into double alternating series. Below the bifur-
cation all the joints are nearly or quite as long as wide, con-
stricted around the middle, and provided with prominent late-
ral projections at the upper and lower ends; all supporting
tentacles, even down to the first pieces above the second
radials. Column rather small, compressed, and composed of
nearly equal, short segments, near the body. Height, to sum-
mit of first radial plates, 0.42 inch; breadth, 0.57; breadth
of base, 0.44 inch; height of do., 0.15 inch.

One of the most marked peculiarities of this crinoid, is the globose form of

its body, which is distinctly gibbous in the middle, and rounded above, as well

as below; its arms are also rather unusually slender in proportion to the size
of the body.

Locality and position: Same as last.

Genus TAXOCRINUS, Phillips.

Synon.—Poteriocrinus ? and Cyathocrinus? (sp.), PuiuLips, 1836. Geol. Yorksh., part ii;

(not Miller, 1821).

Isocrinus, Puituips, 1841. Paleozoic Fossils, p. 30; (not von Meyer, 1837).

Cladocrinus, AUSTIN, 1842. Ann. Mag. Nat. Hist., vol. x; (not Agassiz, 1834),

Taxocrinus, PuLuirs, 1843. Morris Cat. British Fossils, p. 90; McCoy, 1844,
Carb. Fossils, Ireland, p.178; and 1851, Brit. Pal. Foss., p. 53.

Forbesvocrinus, DE Koninck and Levon, 1854. Rech. Crin. Carb., Belgique,
p. 118.

INVERTEBRATES. 269

Generic formula.—
Basal pieces, 3—small, sometimes nearly hidden by the column.
Subradials, 5—one larger than the others, and of different form.
Radials, 3 to 7+-5, or varying sometimes in the different rays of the same.in-
dividual.
Interradials, 0 to 30, or more.
Anal plates, 0 to 30 or 40.
Interaxillary pieces, 0 to 10 (or more) +5.
Arms variously divided.

-Basau pieces small, and often presenting much the appear-
ance of a thickened terminal piece of the column divided into
three parts. Subradials larger, and the one on the anal side
generally larger than either of the other four. Primary radial
pieces all alternating with the subradials—usually four to each
ray, but sometimes three, five, six or seven, the number being,
in some instances, different even in the different ray of the same
individual. All the primary radial pieces, as well as those of
the divisions of the rays, often with a very small supplementary
semicircular piece occupying a corresponding excavation at the
middle of the upper outer margin of each, and usually anchy-
losed to the lower margin of the succeeding piece above. Inter-

‘radial and anal pieces varying, in the typical species, from 0 to

1, 2 or 3 to each space, and in the Forbesiocrinus section, from
about 7 to 10, 12; 15, etc., on up to 30 or more, to each space.
Divisions of the rays in the latter group sometimes soldered
together by small, intermediate pieces, so as to form part of the
walls of the body, and assume the character of secondary or
even Tertiary radials, before giving off the free arms. Vault
apparently only covered by a soft integument. Opening of the
summit unknown. Column round, generally large near the
base, where it is always composed of numerous, very thin
pieces. Surface nearly smooth or granular, and always without
radiating costee.

As here defined, this group is made to include species differing greatly in

the number of anal and interradial pieces; but as we have elsewhere shown
(Proceed. Acad. Nat. ‘Sci., Philad., Aug., 1865, p. 138), they agree so exactly

270 PALEZONTOLOGY OF ILLINOIS.

in all other known points of structure, and present so many gradations in this
character, that we doubt the propriety of making it alone a full generic distine-
tion. It is true, by taking out of the series the species forming the Onychocrinus
group, which we are now inclined to admit as generically distinct, the gradation
from Taxocrinus to Forbesiocrinus is not so complete as we had supposed ; still,
when we remember that the typical species of Taxocrinus vary in the number
of these pieces from none to two or three to each space, and those of Forbesio-
crinus from seven or eight to thirty or forty, while in the latter group individ-
uals of the same species sometimes present a difference of as many as ten of
these pieces to each space, we are still inclined to regard this as merely a sub-
generic distinction. Possibly other characters may yet be found for the sepa-
ration of these groups generically; but until such other distinctions are known
to exist, we prefer to range them as sections of the same genus, as follows:
1. TAXOCRINUS, Parties (proper).

Species without interradial or anal pieces, or with not more than one to three

in each space.

Examples.—7. macrodactylus and 7. Eyertoni, Phillips; 7. nuntius, T. communis,
and 7. Kellogi=(Forbesiocrinus nuntius, F. comvmuis, etc., Hall.)

2. FORBESIOCRINUWS, vz Kontnox and Lznon.
Species with from seven or eight to thirty or more interradial and anal pieces to
each space. '
Examples.—J. nobilis, de Koninck and Lehon; FY. Wortheni and f. Agassizi, Hall.

As first proposed by Phillips, the genus Tazxocrinus included his Poteriocr?-
nus? Lgertoni, Cyathecrinus tuberxculatus, Miller, and C.? macrodactylus and
C.? nobilis, Phillips. The first of these, which is a Carboniferous. species, and
agrecs in all respects with this genus, as generally understood, shows, accord-
ing to Phillips’s fiure, no interradial pieces; and but a single anal piece. The
second species, which is from the Upper Silurian, and is also generally regarded
as a typical Taxocrinus, shows, according to Murchison’s figure (Stluria, pl. 14,
Jigs. 5. and 6), a single interradial piece, resting between the short, superior
lateral, truncated side of each two of the first primary radials; while Miller’s
figure of the same, as reproduced by Pictet (we have not Miller’s work at hand),
shows on the anal side, apparently two small anal plates, resting side by side
down on the short, superior truncated side of one of the subradials. The third
species, 7’. macrodactylus, Phillips, also shows, aecording to his figure (pl. xv,
Palzxozoic Fossils), one interradial, while his 7. noldlis is figured so as to show
of these intermediate pieces, one in one space, and three or more in another,
and is even supposed by de Koninck and and Lehon to be possibly the same
species upon which they proposed to found the genus Forbesiocrinus. So that
it seems very probable that, as understood by Phillips, his genus Taxocrinus
may have included both types, though all the species included by him, with

-

INVERTEBRATES. 271

possibly the exception of the last one (7. nobilis), evidently belong to the genus
as restricted by those who admit the genus Porbesiocrinus.

As McCoy, however, who first followed Phillips in the use of the generic
name Zazxocrinus (Carb. Foss. Ireland, p. 178—1844), evidently viewed 7.
macrodactylus, Phillips, as the typical form of the genus, it would, according to
the most generally accepted rules of Naturalists, become the type of the genus
for all time to come, thougli it would have made no difference had he regarded
any of the others, with possibly the exception of the species nobilis, as the
type, as they are all true Zazxocrinus. At the same time, McCoy also included
another species ( 7’. polydactylus), which, according to his figures and descrip-
tion, appears to have neither anal nor interradial pieces, though it is quite
probable it sometimes has one of each. McCoy at that time, however, descri-
bed the genus as if having five basal pieces directly alternating with five
radial series, and the latter forming free arms, without interradial or anal
pieces; at least he mentions neither of the latter. But in redescribing this
genus in 1851, according to the later improved nomenclature of the parts
(Brit. Pal. Foss., p. 53), he distinctly states that it has ‘five hexagonal inter-
radial plates intervening between the second primary radials, resting on the
upper lateral edges of the first do;” meaning, as is evident from his specific
descriptions, one plate to the anal, and one to each interradial space.

The genus Forbesiocrinus, proposed by de Koninck and Lehon, in 1854
(Rech. Crinoides, p. 18), was founded upon their F. nobilis, suspected by them,
as above stated, to be the same as Taxocrinus nobilis, Phillips. In their descrip-
tion of Forbesiocrinus, these authors characterize it as having five basal pieces,
directly alternating with five series of primary radials, consisting of four pieces
each, with the anal and interradial spaces each occupied by from 12 to 13 pieces,
and the axillary spaces by three small pieces each.

From all the descriptions and illustrations:yet published, of the groups Taz-
ocrinus and Forbesiocrinus, it is therefore clearly evident that these two types
as understood by European authors, are distinguished by Yazxocrinus having
but one or two ranges of interradial pieces, or none, and Forbesiocrinus, from
twelve to thirteen of these pieces occupying each interradial space, and a
few small pieces im the axillary spaces above. In all other points of structure,
and arrangement of parts, whether of the column, basal, radial or arm pieces,
they are understood and acknowledged to agree exactly. But as it has been
found that typical species of Forbesiocrinus, possess three more or less developed
basal pieces within or beneath those regarded as such by de Koninck and Lehon
(dowa Report, p. 628), it might be supposed this character would aid in distin-
guishing the two groups. It is well known, however, that American typical
specigs of Taxocrinus, without interradial or anal pieces, or with but a single
range of the two, such as 7. Theimei and T. juvenis=(Forbesiocrinus Theimei

272 PALEONTOLOGY OF ILLINOIS.

and F. juvenis, Hall, Jour. Bost. Soc., N. H., vii, 317 and 319), possess pre-
cisely the same structure, being both described as having small basal and sub-
radial pieces. Nor can we make the presence of interaxillary pieces (which
occur in both groups), or the small patelliform supplementary pieces, so often
seen at the sutures of the radials and arm-joints in well defined Porbesiocri-
nus, a means of distinction, since they are not always present in otherwise
typical forms of that group, with the interradial spaces filled with plates;
while well marked species of Taxocrinus, such as 7. Thiemei and T. juvenis,
Hall (sp.), the first without anal or interradial pieces, and the latter with
the “‘interradial and anal series, consisting of one plate each,” are deseribed,
the first as having ‘‘arm joints showing the small patelloid plates very dis-
tinctly,” and the latter, with ‘“‘the small patelloid plates indicated by the strong
curvature of the suture lines of the radial plates, becoming more distinct in the
arm plates.” So if we attempt to distinguish these groups at all, we must fall
back upon the difference of the one group being without anals or interradials,
or with but one, two, or three ranges of these pieces, and the other with a
greater number.

The typical forms of this genus range from the Upper Silurian to the top of
the Subcarboniferous ; while those belonging to the Forbesiocrinus group, are
mainly confined to the Subcarboniferous, only a few species apparently of this
type having been described from the Devonian rocks.

TAXOCRINUS SEMIOVATUS, M. and W.

Pl. 20, Fig. 4a, 46.

Forbesiocrinus? semiovatus Manx and WortTHEN, Sept., 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 389.

Paxocrinus semiovatus, Menx and WoRTHEN, Aug., 1865. Proceedings Acad. Nat. Sci.,
Philad., p. 450. :

Bopy? below the first bifurcation of the rays, narrow semio-
vate, a little wider than long, expanding rather rapidly from
the column to the summit of the first radial pieces, above which
it widens more gradually, or becomes nearly cylindrical; com-
posed of moderately thick, smooth or subgranulose plates, uni-
ted by linear sutures. Basal plates hidden by the column, or
merely forming a narrow ring at the connection of the column
with the body. Subradials of moderate size, wider than Jong,
three of them on the anterior side pentagonal, the upper sloping

Le tee

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?

;
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INVERTEBRATES. Zio

sides being considerably longer than the lateral margins; (the
other two unknown). First radial plates on the anterior side,
heptagonal, wider than long, the superior truncated edge being
longer than either of the others. Second radials smaller than .
the first, hexagonal, and nearly twice as wide as long. Third
and fourth radials smaller than the second, wider than long,
and quadrangular or obscurely hexagonal in form, excepting in
one of the rays, where there are only four primary pieces, the
last of which is pentagonal (or obscurely heptagonal?), and
supports the secondary radials. In each of the other two rays
seen, there is a fifth radial piece, which appears to be pentago-
nal, and supports on its superior sloping sides the secondary
radial: pieces.

A remaining portion of a first interradial piece, in one of the
interradial spaces of our specimen, seems to have been penta-
gonal or hexagonal in form, and rests between the sloping sides
of two of the subradial plates, while it connects with a first
and second radial on each side. Anal pieces unknown.

Arms, after the first division on the fourth and fifth radials,
rounded on the outside, and made up of pieces generally wider
than long; one of them, seen in the specimen before us, appa-
rently bifurcating a second time on the sixth piece, and another
apparently on the eighth, beyond which they seem to be simple.
Minute intercalated semicircular pieces between each two of
the primary radials, as well as between the free arm pieces,
more or less distinctly developed. i

Column comparatively large, and tapering gradually from
the base, near which it is made up of extremely thin segments.
Central cavity, as seen in a transverse section, comparatively
large, and distinctly pentalobate. Height of body, to the top
of the first radial pieces, about 0.14 inch; do. from column to
the top of the fifth radials, near 0.41 inch; breadth at the .
summit of the first radials, 0.35 inch; breadth of base, about
0.16 inch.

==) Serr. 14, 1866.

274 PALAONTOLOGY OF ILLINOIS.

Locality and position: Hardin county, Hlinois; St. Louis division of Lower
Carboniferous series.

BLASTOIDEA.

Genus GRANATOCRINUS, Troost.

Synon.— Mitra (sp.), CUMBERLAND, 1826. Reliquie Conservate, p. 31; (not Lam., 1799).
Pentremites (sp.), Auct.—(not Say).

Granatocrinus, TRoosT, 1850. List, Proceed. Am. Ass. Ady. Sci., Cambridge,
p. 62, without figures or description; Hall, Fifteenth Ann. Report Regents
Univ. N. Y., p. 146; Shumard, 1865, Cat. Pal. Foss:, part 1, Crinoidea, p.375.

Pentatremites (sp.), RopMER, 1852. Blastoidea, p. 43; Sowerby and others.

Bopy globose, oval or elliptic. Pseudo-ambulacral areas like
those of the genus Pentremites, excepting that they are propor-
tionally narrower, and extend nearly or quite the entire length
of the body. Basal pieces three, sunken in a concavity so as
not to be visible in a side view. MJadial or fork-pieces gener-
ally shorter than in Pentremites, but otherwise similar; interra-
dials comparatively large, sometimes more than half the length
of the body. Anal opening asin Pentremites; ovarian? openings
intimately connected with the interradials, or sometimes pass-
ing directly through the inner end of each of these pieces.
Arms and column as in Pentremites; surface usually granular,
sometimes coarsely so.

The generic formula of this group is exactly the same as that of Pentremites,
Say, so far as regards the number and arrangement of the pieces forming the
body, though the form and proportions of these pieces are so different as to give
a very different outline and general physiognomy to the entire fossil. They are
therefore readily distinguished from Say’s genus, as properly restricted, by
their regular oval, elliptical, or subglobose form, concave or less protuberant
base, and much narrower and more elongated pseudo-ambulacral areas, which
extend the entire length of the body, so as to give it more the appearance of
an Echinoid. They likewise present differences in the arrangement of the
ovarian? openings of the summit, which are more intimately connected

with the interradial pieces, being sometimes excavated, one into each lateral
margin of these pieces (G. Sayi); or in other instances piercing directly

INVERTEBRATES. 275

through them, so that each pair appears externally, as a single opening (G. melo
und G. Norwoodi), though they divide into two distinct canals before passing
entirely through the plates.* The typical forms of this genus also have the
interradial pieces proportionally much larger than in the true Pentremiites,
though this is not a constant character.

In the possession of numerous, extremely slender, thread-like, simple arms,
arranged along the pseudo-ambulacral areas, this type also agrees (as might
have been inferred from analogy) with the true Pentremites, as we know from
the examination of a beautiful specimen belonging to Mr. Wachsmuth. This
specimen seems to be related to G. Norwoodi, as near as canbe determined,
and shows at least thirty (there are probably more) of these delicate, simple
arms, arising from each pseudo-ambulacral area, and extending up so that the
lower ones must be quite twice as long as the body. They are all composed of
equal joints, about as long as wide. So far as we know, this is the only exam-

ple of a specimen of this type showing the arms, yet found.

This group is even more nearly similar in general appearance, to Nucleocrinus,
Conrad=(Elzacrinus, Roemer), from which it differs in important points of
structure. For instance, in Mucleocrinus, we find the area between two of the
pseudo-ambulacra on the anal side wider, and often more prominent above
than the other interambulacral spaces, and occupied by three large, elongated
pieces, the middle one of which, the anal piece, is lanceolate in form, and with
the two interradials fills all the large anal area down to the base. On compar-
ing this structure with Granotocrinus, the latter is found to differ in having no
such three elongated pieces on the anal side; but only a single anal piece differ-
ing little from the interradials. So marked a difference as this, in the structure
of such simple types, is of course incompatable with generic identity.

As now understood, this genus includes species differing materially in the
comparative size of the interradial pieces, the typical species having those
pieces very large; while in another section of the genus, represented by such
forms as G'. melo and G. Norwoodi, they are as small as in Pentremites. There
are so many gradations in this character, however, that it does not seem to be
possible to make it a means of separating the species into two well defined sec-
tions.

This genus is, so far as known, confined to the Subcarboniferous series.

*In worn or weathered specimens of G. melo and G. Norwoodi, these little interra-
dial pieces, have been so much eroded as to expose each pair of these openings entire-
ly distinct, when they were really united and appeared as a single opening externally,
before wearing.

bo
=I
oo

PALAONTOLOGY OF ILLINOIS.

GRANATOCRINUS CORNUTUS (sp.), M. and W.
Pi, 20, fig. 1.
Pentremites cornutus, Mrrx and WortueEn, October, 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 141.

Granatocrinus cornutus, SHuMARD, Oct., 1865. Cat. Paleozoic Fossils, part 1, p. 375.

Bopy under medium size, subglobose, broader than high, the.
widest part® being at the middle; upper and lower extremities
truncated. Base deeply concave; basal pieces entirely within
the concavity of the under side. Radial pieces long, or extend-
ing from the base of the body to near the summit; narrow,
somewhat contracted above and below, and divided by the
pseudo-ambulacral areas nearly four-fifths their entire length;
all very thick, and rising into prominent carine on each side
of the pseudo-ambulacral fields. Interradial pieces small for a
species of this group, and each projecting out in the form of a
very prominent, compressed, horn-like process. Pseudo-ambu-
lacral areas very narrow or lance-linear, and deeply impressed
between the very prominent, carinated forks of the radial
plates. (Summit unknown.) Height, 0.45 inch; breadth, 0.54
inch; greatest breadth of radial pieces, 0.20 inch; breadth of
pseudo-ambulacral areas, 0.04 inch.

This species will be readily distinguished from all the others of this group,
yet known, by its prominent, horn-like interradial pieces and its strongly cari-
nated radial plates. These carinz are so prominent and regular, as to give the
whole body the appearance of being divided into ten sharply angular ridges or
lobes, extending from near the summit to the base—the intervening depressions
at the sutures, and those containing the pseudo-ambulacral areas, being about
equal.

Locality and position: Near Mt. Sterling, Brown county, Illinois; St. Louis
division of Lower Carboniferous series.

INVERTEBRATES. Qe

ASTEROIDEA.
Genus SCHCANASTER, M. and W.

(czotvos, a rope; aoryp, a star.)

Pa
3 " Synon.—Schenaster (subgenus Palasterina), Menx and WortHeEn, Oct.,.1860. Proceed.
a Acad, Nat, Sci., Philad., p. 449.

a ANIMAL consisting of a flattened pentagonal disc, with the
g p s >

e angles more or less produced in the form of rays or arms, and
- the margins between the rays concave in outline, and fringed

with short, flattened, spine-like appendages, which are also con-
tinued part of the way out along the lateral margins of the rays.
Upper side of rays composed of a number of alternating solid
plates, with the dorsal pores passing between them, while the
angles between the rays are filled with similar plates, forming
the upper side of the disc. Under side of disc composed of «
numerous small plates, very distinctly imbricating inwards
and laterally towards the ambulacra. Ambulacral furrows (in
the typical species) wide, deep, with on each side, a single row
of comparatively stout, squarish or oblong adambulacral pieces,
having an obliquely-outward, imbricating arrangement, so as
to present somewhat the appearance of a twisted cord, as seen
from below; farther out, these become the marginal pieces of
the free rays. There is, however, no regular row of marginal ~
pieces to the disc between the rays. Oral pieces ten, anchy-
losed? in pairs, so as to look like five pieces merely emarginate
at the outer and inner ends. (Other characters unknown.)

Of course it is not possible to give a systematic diagnosis of a genus like this,
of which only imperfect fossil species are known. All that can be done, in
ceases of this kind, is to give such of the more prominent characters as happen
to be visible in the particular specimens accessible; while we cannot always be

~ sure, until better specimens are obtained, and other species known, whether
some of the characters given may not be merely specific, or in other cases of
more than generic importance. At the same time, we have to regret our ina-
bility to give any information in regard to some of the more delicate parts that
would be the first to claim the attention of the zoologist in describing existing
-star-fishes.

278 PALEONTOLOGY OF ILLINOIS.

In first publishing a description of the beautiful species forming the type of
this genus, we referred it provisionally to McCoy’s genus Palasterina, under
the subgeneric name Schanaster. ater comparisons, however, have satisfied
us that it cannot properly be retained in that genus; and as it seems to present
equally important differences from all the other established genera known to
us, we now propose to separate it as a distinct genus, under the name Sche-
naster. It is probably most nearly allied to the Silurian genus, Palasterina,
but differs in the peculiar oblique, outward, imbricating character of its row of
plates on each side of the ambulacral furrows, and the distinct inward imbrica-
ting character of the minute, scale-like plates covering the under side of the
dise. There are likewise differences in the arrangements of the plates and
pores of the dorsal side of the free arms, as seen in our fig. 75, pl. 19.

As the disc is not seen in the specimen from which fig. 7d, of the plate just
alluded to, was drawn, it presents so different an appearance from fig. 7a of the
same plate, showing the upper side of the-fossil, that, looking at these figures
alone, doubts might arise whether or not they belong to the same type. An
examination, however, of the upper side of the same specimen from which 7d
was drawn, as well as of other fragments, show them to be the same. A frag-
ment of the same specimen from which fig. 7d was drawn also shows portions
of the under side of the dise.

Another species, apparently of this genus, from the Burlington limestone,
with much narrower ambulacral furrows,* shows numerous little short, flattened,
spine-like appendages protruding from these furrows, with an outward imbri-
cating arrangement or inclination towards the extremities of the rays. There
may have been other little spines over the outer surface, in addition to those
fringing the margins of the disc, though the specimens retain no traces of them.

SCHGNASTER FIMBRIATUS, M. and W.

Pl. 19, Fig. 7a, 76, 7c, Td.

Palasterina (Schenaster) fimbriata, Mzzx and Wortuen, Oct., 1860. Preceed. Acad.
Nat. Sci., Philad., p. 449.

Bopy regularly pentagonal star-shaped, with the rays pro-
duced into rather acutely pointed arms, which are convex

* We should explain here, that the ambulacral furrow of the enlarged ray, repre-
sented by fig. 7c of plate 19, is proportionally too broad, in consequence of the acci-
dental flattening of the specimen, and in part to the adambulacral pieces being
represented proportionally too small. These furrows are more nearly natural in fig. 7d,
but even in that specimen they are proportionally wider than in undistorted examples.

7s

oe ee ee oe

INVERTEBRATES, 279

above, and about equal in length to the diameter of the disc.
Plates of the upper side of the arms and disc, convex, or even
tumid; near the disc those of the rays hexagonal, heptagonal,
or irregular in form, alternating, and consisting of about five
_ or six longitudinal rows, with a few much smaller intermediate
pieces. Farther out the rays, they gradually pass into two
mesial ranges of oblong, alternating pieces, with their longer
diameter parallel to that of the rays; while on each side of
these, minute irregular pieces fill the space between them and
the marginal pieces. Towards the extremities of the rays,
these little intermediate pieces diminish in size, and at last
become obsolete, leaving only the two middle and outer, or
adambulacral rows. Ambulacral furrows, in apparently undis- _
torted specimens, deep, and nearly or quite twice as wide as
the row of pieces on either side; adambulacral pieces rather
thick and strong, and liable to present considerable differences
in their obliquity and breadth of surface exposed, in conse-
quence of the compression or distortion of the specimen. Plates
of the under side of the disc, very much smaller than the adam-
bulacral, closely crowded together, and owing to their imbrica-
ting arrangement, presenting much the appearance of the scales
of a fish; immediately on each side of the rays, they imbricate
towards the latter, but near the middle of the space between
any two ambulacra, the imbrication is inwards towards the
mouth, so that in tracing the rows parallel to their longer
diameter, across between the rays, they are found to describe
a nearly semicircular curve, with a slight angularity near the
middle.

Near the extremities of the rays, the dorsal pores are seen
to pass between the ends of the two mesial ranges of oblong
pieces, but farther in towards the disc, they are. more irregu-
larly distributed. Our enlarged figure 7, pl. 19, represents
these pores and the dorsal plates, as seen in one of the rays,
with the convex outer portion of the plates ground away, in

280 PALZONTOLOGY OF ILLINOIS.

which condition the pores probably appear larger than natural.
Tn specimens with the tumid portion of these plates unremoved,
the pores are not readily seen, and the whole dorsal side then
seems to be made up of solid, close-fitting pieces. Greatest
diameter across between the extremities of the opposite rays, —
about 2.37 inches; diameter of disc, 1 inch; breadth of ambu-
lacral furrows, about 0.10 inch; length of little flattened mar-
ginal spines, near 0.08 inch.

Locality and position: St. Clair county, Illinois; in the St. Louis division
of the Subcarboniferous series.

MOLLUSCA.

BRACHIOPODA.
Genus PRODUCTUS, Sowerby, 1814.
(Min. Conch., tab. 68.)

Propuctus scrtuzus, M. and W.

PL. 20, figs. 5a, 56, 5e, 5d.

Productus scitulus, Mnzx and WortuENn, October, 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 451.

=

SHELL small, gibbous, wider than long, measuring from the ©
hinge to the anterior curve; hinge line rather more than
equaling the breadth of the central part of the valves; ante-
rior side rounded, or sometimes a little flattened along the mid-
- dle; sides rounding to the front, and straight or somewhat
contracted near the ears. Ventral valve very gibbous, and
rather strongly arched, moderately produced in front, and pre-
senting but slight indications of a mesial sinus; ears triangu-
lar, convex, or somewhat vaulted, sloping up to the convex
visceral region, but separated from the swell of the umbo by a
rounded depression; umbo convex, incurved, so as to bring its
apex apparently a little beyond the hinge line; surface marked

INVERTEBRATES. Zou

by numerous fine, regular, radiating striz,* about seven or
eight of which may be counted in the space of one-tenth of an
inch; crossing these, there are, in the visceral region, a few
obscure traces of concentric wrinkles. A few scattering bases
of spines are also sometimes seen on the ears and anterior
slope (in casts). On some specimens, two or three of the strize
on the anterior slope of the ventral valve become more promi-
nent and larger than the others. Dorsal valve unknown.
Length, from beak to anterior slope, 0.36 inch; do., from the
beak over the curve of the valve, to the anterior margin, 0.45
inch; breadth at the hinge, about 0.45 inch.

The extremely fine strize, and produced anterior margin of this shell, will at
once distinguish it from any other species of its size and general outline, known
to us in our rocks.

Locality and position: Alton, Illinois; St. Louis limestone of Lower Car-
boniferous series.

LAMELLIBRANCHIATA.
Genus MYALINA, de Koninck, 1844.

(An. Foss. Carb. Belg., p. 125.)
MYALINA CoNcENTRICA, M. and W.

Pl. 19, fig. 3a, 36, 3.

Myalina concentrica, hone and WortHEN, Oct., 1860. Proceed. Acad. Nat. Sci., Phila-
delphia, p. 456.

SHELL small, thin, compressed, subquadrate, somewhat higher
than wide, not very oblique; hinge straight, less than the
greatest breadth of the valves below; anterior side a little
sinuous, ranging at an angle of about 85° from the hinge; pos-
terior side compressed, its margin nearly straight and parallel
with the front above, and rounding into the base below; basal

* Not represented fine and distinct enough in the engravings.
—36 Spr. 15, 1866.

282 PALAONTOLOGY -OF ILLINOIS.

margin regularly rounded, anterior edges of the two valves
rather abruptly inflected towards each other, from the suban-
cular, umbonal slopes; beak of left valve pointed, curving
obliquely forward and inward. Surface marked by slender,
rather obscure, regularly arranged, concentric lines, separated
by smooth spaces some eight or ten times as wide as the lines.
Height, 0.75 inch; breadth, 0.59 inch; convexity (of a left
valve), about 0.21 inch.

_ The only specimens of this species yet discovered, so far as we have seen,
are left valves, which are rather distinctly compressed for a species of this

genus. Its small size, compressed form, and comparatively smooth surface, -

will serve to distinguish it from all the other species with which we are
acquainted.

Locality and position: Spergen Hill, near Salem, Indiana; from the horizon
of the St. Louis group of the Lower Carboniferous series.

Genus YOLDIA, Moller, 1842.
(Kroyer’s Nat. Tid., iv, p. 94.)
YoLpIA? LEVISTRIATA, M. and W.

Pl. 20, fig. Ta, 75.

Leda (Voldia?) levistriata, Muzx and Worrumn, Oct , 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 457.

SHELL rather under medium size, transversely subovate, mod-
erately convex in the central and anterior regions; base form-
ing a broad, semiovate curve, the most prominent part being a
little in advance of the middle; anterior side rounded; poste-
rior side compressed, narrower than the other, and narrowly
rounded at the extremity, which appears to be slightly gaping;
beaks depressed and located centrally, or a little behind the
middle; dorsal outline declining slightly and somewhat con-
cave behind the beaks, a little convex in front; surface appa-
rently smooth, but showing under a good lens extremely fine,
regular, closely arranged, concentric strie. (Hinge and

- INVERTEBRATES: 283

interior unknown.) Length, about 0.60 inch; height, 0.20
inch; convexity, 0.14 inch.

This shell is apparently so very closely allied to LZ. subscitula, of Meek and
Hayden (Trans. Albany Inst., vol. 4—March 2, 1858), from Kansas, that we
would scarcely have ventured to regard it as a new species, were it not for the
widely different geological positions occupied by the two shells. The Kansas
species, however, is a little more convex, while its dorsal slope behind the beaks
is rather more concave in outline. It would probably also present other differ-
ences if we had specimens showing the surface markings. As the pallial line
has not been seen in either of these species, it is only provisionally that they
have been referred to the genus Yoldia.

Locality and position: Waterloo, Monroe county, Illinois ; upper part of St. -
Louis group of the Lower Carboniferous series.

Genus Nucutana, Link, 1807.

(Rost. Samml., iii, p. 155.)
NucuLana? curta, M. and W.

Pl. 20, fig. 6a, 60.

Leda curta, Manx and WorTHEN, June, 1861. Proceed. Acad. Nat. Sci., Philad., p. 144.

SHELL small, ovate, rather gibbous in the central and umbo-
nal regions; anterior side abruptly rounded, the most promi-
nent point being at the middle; base semiovate, more promi-
nent in the antero-ventral region than behind; posterior side
abruptly contracted, so as to become subangular at the extrem-
ity; beaks elevated, incurved and nearly central; dorsal out-
line declining rather rapidly from the beaks, the anterior slope
being convex, and the posterior slightly concave; posterior
umbonal slope prominently rounded, or subangular from the
beaks to the narrow anal extremity. Surface ornamented by
very regular, closely arranged, concentric striae, about ten of
which may be counted in 0.05 of an inch. (Hinge and inte-
rior unknown.) Length, 0.32 inch; height, 0.21 inch; con-
vexity, about 0.19 inch.

284 PALMONTOLOGY OF ILLINOIS.

This species will be distinguished, at a glance, from the last, by its much
shorter and more gibbous form, and coarser concentric strie, as well as by its
angular, posterior, umbonal slopes. As we know nothing of its hinge or inte-
rior, it is only placed provisionally in this genus. ’

Locality and position: Same as last.

GASTEROPODA.
Genus DENTALIUM, Linneus, 1758.

(Syst. Nat. Ed., 10, p. 785.)

DENTALIUM VENUSTUM, M. and W.
Pl. 19, fig. 8.

Dentalium venustum, MzEK and WorTHEN, June, 1861. Proceed. Acad. Nat. Sci., Phil-
adelphia, p. 145.

SHELL very slender and slightly tapering, nearly straight,
rather thin; section circular; surface smooth. Length, 0.80

inch; diameter of larger end, 0.09 inch; do., at smaller end,
0.03 inch.

It is probable that where the surface of this shell is well preserved very fine
striz of growth could be seen by the aid of a lens, but in all of those we have
examined, no traces of surface markings of any kind are visible. It seems to
be allied to D. antiquum, of Goldfuss (a Devonian species), but is proportion-
ally thinner, and has a smoother surface. From D. priscum, of Munster, it
differs in being much more slender, and more gradually tapering.

We have before us a few fragments of apparently the same species, but of
larger size, from Spergen Hill, Indiana, where they were found associated with
the small fossils described by Prof. Hall, from that locality.

Prof. Hall has described, in the Iowa Report, p. 666, a larger, more robust,
and more curved species, from Warsaw, Illinois, under the name of D. prima-
rium, and gives the Warsaw limestone as its geological position. This, however,
is an error, the specimen described by him belongs to one of us (A. H.
W.), and is from the Keokuk group, at Warsaw.

Locality and position: Same as preceding.

~

INVERTEBRATES. 285

Genus STRAPAROLLUS, Montfort, 1810. (See page 158.)

STRAPAROLLUS SImILis, M. and W.

Pl. 19, fig. 4a, 40.

Straparollus similis, Menx and Wortuen, June, 1861. Proceedings Acad. Nat. Sci.,

‘Philad., p. 145.

SHELL very small, subdiscoidal; spire much depressed; volu-
tions four and a half to five, increasing rather gradually in size,
horizontally flattened above from the suture to a moderately
distinct revolving angle near the middle of the upper side,
thence a little compressed on the upper outer slope, and rather
narrowly rounded over the periphery; under side of last turn
rounded excepting in the middle, where there is an obtuse, but
well defined revolving angle; umbilicus (measuring across from
its marginal angle on the middle of the body whorl) once and
a half the breadth of the last turn at the aperture, deep, and
showing the inner side of all the whorls of the spire; suture
well defined; aperture subcircular, or a little modified by the
succeeding turn and the flattening on the upper side of the
whorls; lip not oblique; surface marked by rather obscure
lines of growth. Height of a medium sized specimen, 0.18 inch;
breadth, 0.31 inch; diameter of aperture, 0.08 inch.

This delicate little shell seems to be almost an exact miniature of our S.
planodorsatus, excepting that its spire is a little more elevated, its periphery
slightly less regularly rounded, and its umbilicus somewhat smaller. It appears
to stand as it were intermediate between that species and our S. wmbilicatus,
being more elevated than the first and less than the last. It is certainly not
the young of either of these forms, however, since the largest of our specimens
never attain more than one-tenth the size of these shells, and yet have the same
number of whorls.

We have before us specimens of a very closely allied form from Spurgen Hill,
Indiana, which agree exactly in size and form, excepting that the angles of the
whorls are less distinct, and the flattening of the upper side of the whorls is not
quite so broad. These, we think, probably belong to the species under consid-
eration, as they differ from any of those described by Professor Hall from that

286 PALZONTOLOGY OF ILLINOIS.

locality, resembling them in other respects, in having a smaller umbilicus, more.
rapidly enlarging whorls, and a more.elevated spire.

Locality and position: Same as preceding.

STRAPAROLLUS SIMILIS, va7, PLANUS.

Pl. 19, fig. 5a, 56, 5e.

Straparollus similis, var. planus, Meek and Wortumn, June, 1861. Proceed. Acad.
Nat. Sci., Philad., p. 146.

This form differs from the last in having its spire completely flattened so as
to be upon a level with the last tura, and im having a slightly larger umbilicus;
while the angle on the under side of the body whorl is a little farther out from
the umbilical side. The flattened space on the upper side of its whorls also
differs in sloping inwards instead of being horizontal, and its suture seems to
be more distinct. Notwithstanding these differences, these forms agree so very
nearly in size and other respects, that we do not feel quite warranted in re-
garding them as distinct species. Should it be thought necessary, however, to
separate them specifically, the form under consideration can take as a specific
name that by which we have designated it as a variety.

It is an interesting fact that these two forms present exact miniature repre-
sentations, of the two varieties of S. pentangulatus, Sowerby (sp.). The fact,
however, that the shells under consideration show all the appearances of mature
growth, and never attain more than one-twentieth the size of S. pentangulatus,
while they have only two or three whorls less, is, we think, sufficient reason
for regarding them as distinct.

Locality and position: Same as preceding.

CEPHALOPODA.
Genus ORTHOCERAS, Auct.

ORTHOCERAS EXPANSUM, M. and W.

Pl. 20, fig. 8a, 8b, Be.

Orthoceras expansum, Mrnx and Worruen, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 468. 3 :
Suet having the form of a moderately compressed, rapidly
tapering cone; section subcircular, near the smaller end, but

INVERTEBRATES. 287
more oval towards the larger extremity. Septa concave, and
separated near the smaller end by spaces between one-fourth
and one-fifth their own greater diameter ; the intervals increas-
ing somewhat, but not near in proportion to the expansion of
the shell, above. Siphuncle subcentral, small where it passes
through the septa, but swelling out into globular cavities be-
tween. Surface apparently smooth. Length of a specimen
imperfect at both extremities, and entirely septate, 4.30 inches;
greater diameter at the larger end, apparently not less than
3.20 inches; do. at smaller end, 0.80. Our specimen being
somewhat distorted, the measurement at the larger end cannot
be given definitely.

This species seems to be related to O. dilatatum, de Koninck (An. Foss., p.
515, pl. 45, fig. 8a, 8b, 8c), but differs in presenting an oval, instead of a
circular section, excepting near the smaller extremity; its siphuncle is also
more nearly central than is represented in de Koninck’s figure 8a and 88, pl.
45, and differs in its peculiarity of expanding into globular cavities between the
septa, as in the group Actinoceras. It seems likewise to differ in its surface
markings, being nearly smooth; this, however, may be due,.at least in part, to
the exfoliation of the outer layers of the shell.

Locality and position: McDonough county, Illinois. As the.specimen was
found loose, its exact geological position is unknown, but it most probably came
from the St. Louis group.

INVERTEBRATE FOSSILS OF THE CHESTER GROUP.

RADIATA. ‘
ECHINODERMATA.
CRINOIDEA.
Genus PTEROTOCRINUS, Lyon and Casseday.

Asterocrinus, Lyon, 1857. Geol. Report Ky., vol. iii, p. 472; (not Munster, 1831).
Pterotocrinus, Lyon and Cassepay, Jan., 1859. Am. Jour. Sci. and Arts, vol. xxix, p. 68.

Generic formula.—
Basal Plates, 2.
Radials, 1 or 24-5; the second minute or sometimes wanting.
Secondary radials, 1-+10; small, and easily confounded with the brachial
pieces.
Anal pieces, 1, known.
Interradials, 4; small probably, sometimes wanting .
Arms, 20. .
Interbrachial appendages, 5; very large.

Bopy, below the arms, broad and short; truncated, concave,
and often rounded below. Base depressed or discoid. First
radial pieces much larger than the second; two of them rest-
ing upon each of the two basal pieces, and the fifth occupying
a more or less defined notch at the anterior end of the suture
between the basal pieces, so as to rest partly upon each of the
latter. Anal piece in the typical species, small, but in others
larger, or nearly or quite equaling the first radials, between

INVERTEBRATES. 289

two of which it is placed so as to rest upon the basal pieces in
a notch at the posterior end of the suture separating the latter.
Second radials very minute, or apparently sometimes obsolete;
when present occupying a small depression at the middle
of the upper side of the first radial pieces. Secondary radial
pieces small, and not always readily distinguished from the
first brachial pieces—resting either in part or entirely upon the
first radials, owing to the minuteness or absence of the second
radial pieces; supporting above, the brachial pieces, the inner
two of which, however, sometimes rest in part upon the small
second primary radial, and the outer two, in part, even down
upon the first primary radial. Interradial pieces small or
wanting, and not, when present, very distinct from the vault
pieces; never more than slightly truncating the superior lateral
angles of the first primary radials.

Interbrachial appendages (wing or lobe pieces of Lyon), in
the typical species very large, and a rising from between the
inner arm-bases; sometimes thin and knife-like, and in other
species greatly thickened and bipartite—often nearly equaling
the length of the arms, but sometimes shorter, or probably in
some species obsolete.

Arms, so far as known, four to each ray, and, excepting at
their immediate bases, composed each of a double series of very
short alternating pieces, each one of which supports a tentacle;
not bifurcating after the divisions at their bases.

Vault, according to Mr. Lyon, composed in the typical spe-
cies of comparatively few pieces, and having the opening
nearly central. In other species apparently falling within this
genus, the opening is lateral. Column apparently round.

As remarked in connection with the description of that genus, on page 167,
this type is related most-nearly to Dichocrinus, though it differs in general
form, as well as in the structure and arrangement of all the parts above the

first radials. It seems to include species constituting two sections or subgenera,
the first or typical one of which is characterized by the greatly developed inter-

ae Wi Supz. 17, 1866.

290 PALEONTOLOGY. OF ILLINOIS.

axillary appendages (wings of Lyon *), and a central or subcentral opening of
the vault, with a small first anal, and short first radial pieges. The other sec-
tion consists of species with the interaxillary appendages small or wanting, the
opening of the summit lateral, and the first anal pieces nearly or quite as large
as the first radials. Of the latter group, Dichocrinus cornigerous, of Shumard,
is an example; it will probably also include D. sexlobatus, of Shumard.

It will be observed that the last mentioned section bears somewhat similar
relations to the typical species of this genus, that Plewrocrinus, of Austin, bears.
to Platycrinus.

All the species of this group known to us, are from the Chester division of
the Subcarboniferous series, or near that horizon. i

PTEROTOCRINUS CRASSUS, M. and W.
Pl. 23, fig. 2a, 20.

Dichocrinus (Pterotocrinus) crassus, Merk and WorTHEN, Sept., 1860. Proceed. Acad.
Nat. Sci., Philad., p. 382.

Bopy below the arms basin-shaped, more than twice as wide
as high; widening rapidly upwards from the base; composed
of thick, apparently smooth plates, connected by linear sutures.
Base comparatively large, about four times as wide as high, dis-
tinctly concave below, and widening upwards from its round-
ed lower margin; slightly sinuous at the extremities of the
suture; columnar facet round, concave, and about one-fourth
as wide as the base. First radial plates broader than long, a
little convex, widening regularly upwards from the base, and
concave on the upper side, which is longer than either of the
others; four of them subquadrangular, with the lateral angles
slightly truncated, and one on the anterior side, subpenta- ;
gonal in consequence of having a fifth obscure angle at the ;

* Mr. Lyon seems to think these appendages were articulated, or movable, so as to
have been used in seizing and crushing food.’ In this view, however, we cannot con- 4
cur. So far as we have been able to see, these appendages appear to us to be enor-
mously developed vault pieces, analogous to the great spines seen rising from the vault 5!
of Dorycrinus. In some species they were directed obliquely outwards, and in others
they were more erect, but we cannot believe they were movable like the arms.

‘ INVERTEBRATES. 291

middle of its lower margin. Anal plate as long, and three-
fourths as wide, as the first radials, contracted a little above.
Second radials very small, rudimentary, or possibly some-
times obsolete, not generally very readily distinguished from
the minute secondary radial and first brachial pieces; sup-
' porting above, the brachial pieces of the two inner. arms, and
on their short outer sloping sides, the short inner sides of the
two minute secondary radial pieces, which, however, also rest
mainly down upon the first radial pieces, and support the two
outer arms of each ray.

First two or three arm pieces much larger than the others,
closely connected laterally, and consisting of a single range to
each arm. Above these they soon pass into double ranges of
small, alternating pieces, which are three or four times as wide
as long, and bear on their inner sides a double series of ten-
tacles. Arms (of which there are four to each ray, or twenty
in the entire series) round on the outer side, and deeply grooved
within, slightly tapering, apparently rather long and entirely
simple. Tentacles slender, very closely arranged, and com-
- posed of joints which are three or four times as long as wide.
Interbrachial appendages arising from the middle of each group
of arms, thin or knife-like on their outer edges above, much
thicker’ below, and apparently nearly or quite as long as the
arms. Height of body to summit of first radials, 0.33 inch;
breadth of do. just below the arms, 0.84 inch; breadth of
base, 0.60 inch; height of do., 0.16 inch. Breadth of arms,
0.12 inch.

292 PALAONTOLOGY OF ILLINOIS.

This species seems to be related to P.
pyramidalis, of Lyon and Casseday (Am.
Jour. Set., 2d ser , vol. 29, p. 69), but dif-
fers in the proportions of the calyx below
the arms, its height and breadth being as

Its first radial plates are also proportion-
ally much higher, and less concave above,

judging from Messrs. Lyon and Casseday’s
Pterotocrinus erassus,—(Nat, size.) description

This diagram shows the arrangement of the
basal, radial and anal pieces; and in two of the ‘ aie 3
rays, the secondary radials, brachial pieces Locality and position : Hardin county,

d t cat :
Se ROT ton en Illinois, Chester group ; Subcarboniferous.

PTEROTOCRINUS CHESTERENSIS, M. and W.

Pl. 23, figs la, 16, We.

Dichocrinus (Pterotocrinus) chesterensis, MemK and WorTHEN, Sept., 1860. Proceed.
Acad. Nat. Sci., Philad., p. 383,

Bopy below the arms rather small, basin-shaped, or more
than twice as wide as high, widening rapidly upwards from
the base, the sides being slightly concave in outline; composed
of moderately thick, apparently smooth plates, which are con-
nected by linear sutures. Base more than one-third as broad
as the body, about three times as wide as high, truncated and
concave below; the concavity being margined by an angular
rim; columnar facet small, or less than one-third as wide as
the truncated under side of the base. First radial plates about
the size of the basal pieces, though proportionally higher, twice
as wide as long, and widening rather rapidly from below; four
of them quadrangular and one on the anterior side pentagonal;
all distinctly concave on the upper side (which is longer than
either of the others), and having their salient upper lateral
angles slightly truncated for the reception of small interradial
pieces. Second radial pieces minute or merely rudimentary,
triangular, and each partly supporting on its sloping upper

INVERTEBRATES. 293

edges two larger secondary radial pieces, which also rest with
one side directly upon the first primary radials. Secondary
radials small, irregularly pentagonal, and bearing upon their
- upper sloping sides the first brachial pieces, the outer two of
which in each ray, likewise have each one edge reposing upon
the lateral superior edge of the first primary radial. Anal
piece about one-third as wide as each first radial; ovate in form,
the upper extremity being very narrow, the lateral margins con-
vex, and its base having an obtuse angle on each side, and,one
in the middle. Arms (of which there are four to each ray, or
twenty in the entire series) simple from their origin, all rounded
on the outside, deeply grooved within, and each commencing
with a single series of large pieces, but soon passes into a double
alternating series of small pieces, bearing two ranges of tenta-
cles. Interradials apparently little larger than the first
brachial pieces, and probably wanting between the anal piece
and the first radials on each side. (Interbrachial appendages
unknown.) Height from base to summit of first radials, 0.16
inch; breadth at the top of first radials, 0.40 inch; breadth of
base, 0.24 inch; height of ditto, 0.16 inch; length of anal piece,
0.15 inch; breadth of ditto, 0.09 inch.

Fig. 30. The smaller size and more graceful form of this species,
ey together with its much narrower, angular base, will at once
— a distinguish it from the last. The sides of its body below
CG) the arms also differ in being more concave in outline, while
a \ < its anal piece is more contracted above and its arms more
EEA a / slender.

It is probably nearer P. pyrimidalis of Lyon and Casse-
Pterotocrinus chesterensis. day, but differs in being much smaller, and in having the

(Nat. size.)

bis ots ie margins of its base angular instead of obtusely rounded.
and in two of the rays, It likewise differs in the proportions of its body below the
eee eieudae arms, the height and breadth being as 16 to 40, while the
layered pisces ak and same measurements of P. pyrimadalis are given as 18 to 80.

Locality and position ; Same as last.

294 PALEONTOLOGY OF ILLINOIS.

ECHINOIDEA.
PHRISCHOECHINIDA. (See page 225.)

Genus ARCH AOCIDARIS, McCoy.

Synon.—Echinoerinus,* AGAssiz, 1841. Monogr. Ech., ii, Introd., p. 15; McCoy, 1844,
Carb. Foss. Ireland, p. 173. __
Archxocidaris, McCoy, 1844. Ib.
Palzocidaris, Dusor, 1846. Cat. Rais., p. 58.

SpHERICAL or depressed spheroidal. Ambulacra compara-
tively narrow and composed of two ranges of small pieces,
with two pores to each piece. Inter-ambulacral plates large,
thin, and each provided with a large, perforated, central tuber-
cle, surrounded at its base by a smooth ring, and rounded at the
extremity for the articulation of the primary spines; surround-
ing the whole is a more or less complete circle of marginal, or
submarginal, smaller tubercles, for the articulation of the sec-
ondary spines. Apical disc unknown. Mouth surrounded ap-
parently by a membrane, covered by numerous minute, imbri-
cating plates. Jaws strong, trigonal, with a distinct mesial
suture. Primary spines large, cylindrical, compressed, or
angular, and generally armed with small, oblique, lateral
spine-like projections; surface variously ornamented with gran-
ules and fine strie.

This genus is nearly allied to ocidaris, of Desor ( Synop. Ech., 1858, p. 155),
from which, according to him, it is mainly distinguished by the presence of
the ring around the base of thé primary tubercle of each interambulacral plate.
From Perischodomus, of McCoy, it is readily distinguished by having a large
central tubercle in each of its interambulacral plates, instead of only on those
of the marginal rows, on each side of the ambulacra.

Prof. Hall has described a very remarkable type from the Burlington group,
under the name Lepidechinus (Descr. New Sp. Crinoidea, Prelim. Notice,

* The name Hehinocrinus, which has priority of date for this genus, has probably
not been adopted by Palzontologists, because they think it liable to mislead the stu-
dent in regard to the affinities of these fossils.

INVERTEBRATES. 295

Albany, p. 18), which is distinguished by having the interambulacral plates all
distinctly imbricating from the dorsal side, and those of the ambulacral series
imbricating from below upwards. He places it as a subgenus under Archzo-
cidaris, but we should think it generically distinct, if indeed the differences are
not of more than generic importance. He says the ambulacral and the inter-
ambulacral plates, with the exception of their singular imbricating character,
are arranged as in Archexocidaris; but by an oversight he omits, both in
the subgeneric and specific descriptions, to mention the nature of the tuber-
cles of the interambulacral plates. Judging from some imperfect speci-
mens we have seen, however, that show the remarkable imbricating character
of the plates alluded to, and which doubtless belong to Lepidechinus, there
were apparently no primary tubercles on any of the interambulacral plates
of the under side of the fossil, excepting the marginal rows. If this is
so, this type is very near Perischodomus of McCoy, and may be found to belong
to the same group. It is true the imbricating character of the plates is not
mentioned in the description of the fossil described by Prof. McCoy, but
owing to the fact that only a single very imperfect specimen of it has, we
believe, yet been found, this character might have been overlooked.

We have not seen specimens of Archxocidaris showing very clearly the
number of rows of interambulacral plates. In several specimens we have been
able to count four rows, but as these specimens did not show the middle por-
tions of the fossil, it is highly probably there were several additional rows.
Judging from analogy, there was probably always an odd number of these
plates. As in other types of the suborder, the inner interambulacral plates
are hexagonal in form, and the marginal rows pentagonal. oe

According to Desor, this genus is peculiar to the Carboniferous system. It
occurs in both the upper and lower divisions ; and in the eastern parts of Kan-
sas, it is found in beds referred by Prof. Swallow to the Permian. The Euro-
pean Permian species originally placed in this genus, are referred by M. Desor
to his genus Hocidaris.

ARCHMOCIDARIS MUCRONATA, M. and W.
Pl. 23, Fig. 3a, 36, 3c.

Archzocidaris mucronata, MrmK and WorTHEN, Sept., 1860. Proceedings Acad. Nat.
Sci., Philad., p. 395.

PRIMARY spines long, gradually tapering, slightly compressed
or nearly round, and apparently a little curved a short distance

296 PALEONTOLOGY OF ILLINOIS.

above the articulating extremity; articulating end moderately
enlarged, and provided with a subangular ring, from which it

is abruptly contracted; outer extremity terminating in a

mucronate point. Entire surface from about three quarters of’
an inch above the larger end, armed with rather strong, sharp,

but short lateral spinules, which are directed obliquely out-

wards and upwards. In most cases the surface seems to be

entirely smooth, with the exception of the spinules, but by

the aid of a magnifier, extremely fine, closely arranged longi-

tudinal striee may sometimes be seen on well preserved speci-

mens. The articulating end is perforated by a round aperture;

and transverse sections show the central cavity to be compar-

atively large for some distance up.

The only specimens of this specics yet obtained consist of
detached primary spines, and a few of the interambulacral
plates. The latter are wider than long, and apparently nearly
smooth, or only ornamented by a single row of small tubercles
around the margin; central tubercle prominent, and nearly
equaling one-third the greater diameter of the plate, most ele-
vated in the middle, which has a small central pit, and is
separated from the surrounding ring by a distinct annular
groove. Length of one of the interambulacral plates, about
0.50 inch; breadth of do., 0.35 inch. Length of a primary
spine, 2.60 inches; greatest diameter of the same above the
articulating end, 0.16 inch; diameter of head, 0.19 inch.

The primary spines of this species present much the appearance of the
enlarged figure of A. Norwoodi, given by Prof. Hall, on plate 20 of the Iowa
Report. They are, however, much more robust, being nearly four. times as
large as the natural size of the spines of that species, and also differ in being

entirely destitute of granules, between the lateral spinules; while their longi-
tudinal strize are proportionally finer.

Locality and position: Liberty, Randolph county, Illinois; upper part of
Chester group.

INVERTEBRATES. 297

-MOLLUSCA.

BRACHIOPODA.
.Genus PRODUCTUS, Sowerby, 1812.

(Min. Conch., i, p. 153.)

Propuctus PARVUS, M. and W.

Pl. 23, figs. 4a, 46, 4c, 4d, 4e.

Productus parvus, Mrzrx and WortHEN, October, 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 450.

SHELL rather small, nearly hemispherical, without any traces
of a mesial sinus; length and breadth about equal; hinge
equaling the greatest breadth; front rounded; sides intersect-
ing the ears nearly at right angles, sometimes slightly sinuous
near the hinge. Ventral valve gibbous, regularly arched, not
depressed in the visceral region; beak incurved a little beyond
the hinge; ears small, moderately distinct from the swell of
- the umbo, not flattened. Dorsal valve deeply concave, partic-
ularly in the middle and towards the beak. Surface of both
valves ornamented by numerous small, rounded, rather closely
arranged, occasionally bifurcating striz, about six of which
may be counted in the space of one-tenth of an inch Spines
small, erect, apparently confined to the ventral valve, each ear
of which supports some seven or eight, while there are usually
about three times that number scattered around the lateral and
anterior slopes. Sometimes very obscure traces of small con-
centric wrinkles are indistintly visible near the beak and on
the ears, particularly of the ventral valve. Length, 0.54
inch; breadth, 0.55 inch; convexity, 0.38 inch.

This species might be mistaken, at a first glance, for P. elegans, of Norwood
and Pratten. On comparison, however, it will be found much less produced
in front, while the convex part of its ventral valve is not so attenuated towards

ae Szpr, 18, 1866.

298 PALEONTOLOGY OF ILLINOIS.

the beak, which is less prominent. Its hinge line is also more extended, its
surface strize finer and more regular, and its dorsal valye much more deeply
concave. This valve likewise always differs in being entirely destitute of the
concentric ridge so characteristic of P. elegans.

It differs from P. dongispinus, in always having much finer and more regu-
lar striee, with less distinct concentric wrinkles; while its dorsal valve is
uniformly more deeply concave, particularly in the middle.

It is much more closely allied to Productus Flemingwi, of Sowerby—a variety
of P. longispinus—than to the typical forms of that species. On comparison,
however, with authentic specimens of P. Flemingii, sent from Scotland by Mr.
Thomas Davidson, we find our shell has the umbo of its ventral valve more
ventricose, and more incuryed, while its dorsal valve is always more deeply
concave, particularly near the beak and in the middle.

Locality and position: Chester, Illinois; Chester group of the Lower Car-
boniferous series.

" Genus SPIRIFER, Sowerby, 1815.

_ (Min. Conch., ii, p. 42.)
Susgenus MARTINIA, McCoy, 1844.

SPIRIFER GLABER, var. CONTRACTUS, M. and W.

Pl. 23, fig. 5a, 58.

Conchyliolithus anomites glaber, MARTIN, 1809. Petref. Derb., pl. xlviii, fig. 9, 10.
Spirifer glaber, SowERBY, 1820. Min. Conch., vol. iii, p. 123, pl. eclxix, fig. 1.
Spirtfer obtusus, SowERBy, 1820. Ibid, fig. 2.

Spirifer oblatus, SowmRBy, 1820. Ibid, pl. celxviii.

Trigonotreta oblata, BRonn, 1836. Leth. Geog., p. 81, pl. ii, fig. 16.

Spirifera linguifera, PHILLIPS, 1836. Geol. Yorksh., vol. ii, p. 219, pl. x, fig. 4.

_ Spirifera symmetrica, Purnuips, 1836. Ibid, fig. 13.

Spirifera discora? Puiuuirs, 1836. Ibid, fig. 9.

Spirtfer levigatus, von Bucu, 1840. Mem. Soc. Geol. France, vol. iv, p. 198.
Spirifer obtusus, and S. oblatus, McCoy, 1844. Synops. Carb. Foss. Ireland, p. 139.

SHELL rather under medium size, quadrato-subcircular in out-
line, becoming moderately gibbous with age; length and breadth
nearly equal; sides rounded; hinge short, or scarcely equaling
half the breadth of the valves near the middle. Dorsal valve
much more compressed than the other, most convex along the

~~

INVERTEBRATES. | 299

middle from near the beak to the front, and sloping towards
the sides ;” hinge margin truncated ; beak very small, scarcely
projecting beyond the hinge line, slightly incurved; area narrow.
Doxset valve gibbous, provided with a narrow, shallow sinus,
——— . . . e .
commencing near the middle and widening to the front, which
is a little produced to fill a shallow sub-semicircular sinus in
the anterior margin of the opposite valve; beak prominent,
incurved, and rather pointed at the extremity; area very much
contracted, triangular, more or less arched, and very obscurely
defined; foramen rather large, or occupying three-fourths of
the small area, having nearly the form of an equilateral tri-
angle and apparently always open to the beak. Surface nearly
smooth, or only having obscure marks of growth, and some-
times showing, by the aid of a lens, faint traces of a radiating
strie. Length of largest specimen, 0.90 inch; breadth, 0.86
inch ; convexity, 0.60 inch; length of hinge, 0.45 inch.

This shell agrees so nearly with some varieties of Spirifer glaber, Martin
(sp.), that we have not been able to fully satisfy ourselves that it is specifically
distinct, though we strongly suspect that it will prove to be so. In form it is
almost exactly like Mr. Davidson’s fig. 33, pl. 1*, of his Monograph of the
Carboniferous Brachiopoda of Scotland, representing a rather small specimen
of Martin’s species. It differs, however, from this and all the varieties of S.
glaber we have seen figured, in having a much smaller and more obscurely de-
fined ventral area. Indeed the sides of the beak of its ventral valve round in
so regularly to the foramen, that it is often difficult to see where the margin of
the area is. As this character is persistent in the five specimens of different
ages that we have seen, we should not hesitate to consider our shell distinct
from S. glaber, were that species not known to be so extremely variable.

The specimen we have figured is the largest we have seen, the smaller ones
being more compressed and more regularly rounded in outline, though none of
them are so transverse as the prevailing forms of Martin’s species, figured by
Mr. Davidson and others.

Locality and position: Chester, and in Pope county, Illinois; Chester group
of the Lower Carboniferous series.

Glee ae BPS ee, 7% Ss, ayo Hack, Goi JL CHES
ae Tone Vk Zo ate xXVi/, fer: Ep ih a {a er —_ a
ie a! Pres) (Sores deat TAP Lesces

ai a7 - a aoe -

v

a

300 PALEONTOLOGY OF ILLINOIS.

LAMELLIBRANCHIATA.
Genus MYALINA, de Koninck, 1844.

(An. Foss, Carb. Belg., p. 125.)

MYALINA ANGULATA, M. and W.

Pl. 23, fig. 7a, 76.

Myalina angulata, Mrrx and WorrTHEN, Oct., 1860. Proceed. Acad. Nat. Sci., Phila-
delphia, p. 455.

SHELL rather large, obliquely subtrigonal, nearly equivalve,
very convex and distinctly angular along the umbonal slopes,
cuneate in the posterior and postero-dorsal regions. Anterior
margins abruptly inflected from the imbonal angles, so as to
meet on a plane at right angles to that of the valves;
nearly straight, and sloping obliquely backwards at an
angle of about 57° below the horizon of the hinge, to the nar-
rowly rounded basal extremity. Hinge straight, nearly or
quite equaling the horizontal length of the shell, and termi-
nating in a rather acute angle behind. Posterior margin form-
"ing a broad convex curve from the narrowly rounded base up-
wards nearly to the hinge, thence curving gracefully outwards
to its extremity. Beaks terminal, prominent, or extending
above the hinge, incurved, and acutely angular; strongly com-
pressed in front and behind. Surface of cast retaining rather
obscure marks of growth. Height, measuring at right angles
from the hinge, about 2.55 inches; length, parallel to-the
hinge, 2.57 inches; length from the beaks, parallel to the um-
bonal slopes, to the base, about 3.20 inches; convexity of the
two valves, near 1.30 inches.

The extremely compressed, prominent beaks, and remarkably convex angu-
lar umbonal slopes of this shell, will at once distinguish it from all the other
known species of the genus. It is also peculiar in having the posterior ex-
tremity of the hinge rather acutely angular, judging from the curve of the

INVERTEBRATES. . Boh

lines of growth, in consequence of the sinuate outline of the posterior margin.
The compression of the beaks, mentioned above, is not in the direction of the
plane of the valves, but from the anterior and posterior sides, in consequence
of which their transverse diameter is conSiderably greater than that at right
angles to the same.

Locality and position: Chester, Illinois; Chester group of Lower Carbon-
iferous series.

Genus SCHIZODUS, King, 1844.

(Ann. and Mag. Nat. Hist., p: 64.)

SCHIZODUS CHESTERENSIS, M. and W.
Pl. 23, fig. 6a, 6d.

Schizodus chesterensis, MEEK and WorTHEN, Oct., 1865. Proceedings Acad. Nat. Sci.,
Philad., p. 457.

SHELL rather above medium size, transversely ovate, convex
in the anterior and umbonal regions, cuneate posteriorly ; an-
terior side regularly rounded; base forming a broad semiovate
curve, being more prominent in the central and anterior
regions than behind ; posterior side contracted, longer than the
other, and narrowly rounded at the extremity; dorsal margin
nearly straight, and declining slightly behind the beaks, from
which it rounds regularly into the anterior border; beaks gib-
bous, rather elevated, incurved, and located less than one-third
the length of the shell from the anterior margin. Muscular
impressions shallow; anterior ones ovate, placed near and
a little above the middle of the anterior margin; posterior
impressions ovate, located close up under the dorsal margin,
between the middle and the anal extremity. Surface marked
by fine, regular concentric strie. Length, of an internal cast,
1.38 inches; height of same, 1 inch; convexity, 0.68 inch.

This species resembles Schizodus obscurus, of Sowerby, from the Permian
rocks, but is smaller, has less elevated beaks, and differs in having the most

5

302 PALEONTOLOGY OF ILLINOIS.

prominent part of its posterior extremity above, instead of below the middle.
Its concentric striz are also stronger and more regular. The specimen we have
fizured is an internal cast, retaining only very obscure traces of these striz;
but others before us have some remaining portions of the shell, on which they
are distinctly visible, particularly on the anterior side of the umbones, where
they seem to have been most strongly marked. It has more nearly the form
of a shell figured by McCoy (Carb. Foss. of Ireland, pl. 8, fig. 6), under the
name Anatina attenuata, but has its beaks more elevated. The form figured
by Prof. McCoy is probably a Schizodus, at any rate it is almost beyond doubt
not an Anatina.

Locality and position: Chester, IHinois; Upper part of Chester group, of
Lower Carboniferous series.

GASTEROPODA.
Genus STRAPAROLLUS, Montfort, 1810. (See page 158.)

(Conch. Syst., ii, p. 174.)

STRAPAROLLUS PLANIDORSATUS, M. and W.

Pl. 24, fig. 2a, 23, 20.

nisiaaiiahhe planidorsatus, Munx and Wonkant Oct., 1860. Proceed. Acad. Nat. Sei.,
Philad., p. 462.

SHELL of medium size, subdiscoidal; spire nearly flat, or but
slightly elevated above the body whorl; volutions about five,
increasing gradually in size, flat above, and provided with a
moderately distinct revolving angle about two-thirds of the
distance across from the inside. From this angle the last whorl
is regularly rounded over the periphery to about the middle of
the under side, where there is another angle, from which the
inner side of the whorl rounds into the umbilicus. Suture
well defined. Umbilicus large, deep, and showing about one-
half of each inner whorl; aperture subcircular. Surface often
scarcely showing any strize, but in some instances with obscure
lines of growth most distinctly seen in the umbilicus. Breadth,
1 inch; height, about 0.30 inch.

INVERTEBRATES. 303

This species is evidently closely related to Hwmphalus pentangulatus of
Sowerby (Min. Oon., i, p. 97, pl. 45, fig. 1 and 2), but is smaller, and differs
in having the angle on the upper side of the whorls located nearer the outer
margin. Its periphery is also much less prominently rounded, its whorls less
rounded below, and its umbilicus proportionally deeper.

We find these differences particularly in the position of the angle on the
upper side of the inner whorls, and the less prominently rounded side of the
body whorl in our shell, quite obvious on comparison with authentic specimens
of E. pentangulatus, from Ireland.

Our species seems to be also very near, if not really identical with a form
subsequently described by Prof. Swallow, from the same horizon, under the
name Huomphalus perspectivus (Trans. St. Low's Acad., May, 1862). A draw-
ing, however, of Prof. Swallow’s shell, shown one of us by him, represents
much stronger marks of growth than we have yet seen on our species.

Locality and position: Thompson’s quarry, Randolph county; Chester group
of Lower Carboniferous series. Also, in the same position in Saint Genevieve
county, Missouri.

Genus PLEUROTOMARIA, Defrance; 1826.
(Dict. Sci. Nat., xli, tab.’86.)
PLEUROTOMARIA CHESTERENSIS, M. and W.

Pl. 24, fig. La, 18, Le.

Pleurotomaria chesterensis, Merk and WortHEN, October, 1860. Proceed. Acad. Nat.
Sci., Philad., p. 460.

SHELL of medium size, turbinate; spire moderately elevated;
volutions about six, convex, distinctly carinated around the
middle, and flattened or concave above and below the carina,
the flattened space above being oblique, and that below verti-
cal; last whorl provided with a second carina below the first,
and slightly convex on the under side; suture linear; umbili-
cal perforation small, or nearly closed; aperture subquadran-
gular, and a little wider than high; spiral band occupying the
middle of the vertically flattened’ space between the two carine
on the body whorl, and passing around about half-way between

304 PALAHONTOLOGY OF ILLINOIS.

the middle and the suture at the base of each of those compos-
ing the spire. Surface marked by numerous fine, regular,
thread-like revolving lines, crossed- by similar striz, which in
traversing the spiral band, make a slight backward curve
parallel to the margin of the sinus in the lip. Length, 0.75
inch; breadth, 0.72 inch; apical angle regular, divergence
60°; breadth of spiral band, about 0.04 inch.

This species resembles P. tabulata, of Conrad, but is smaller thah the average
size of that shell, while it differs in having its spiral band located midway be-
tween the two. carinz, instead of coincident with the upper angle of the body
whorl. It also wants the crenulations on the principal angle, so well marked
on that of P. tabulata, and-is slightly umbilicated, instead of having an imper-
forate axis, as in Mr. Conrad’s species. Again it differs in being much more
finely and more regularly cancellated over the entire surface; being in this
respect much more like the species we have referred to, P. Brazoensis, of Shu-
mard, from which it will be readily distinguished by its other characters.

Locality and position: Chester, Illinois ; Chester group of the Lower Car-
boniferous series.

CEPHALOPODA.
Genus ORTHOCERAS, Auct.

ORTHOCERAS ANNULATO-CosTATUM, M. and W.
Pl. 24, figs. 3a, 36.
Orthoceras annulato-costatum, MuExK and WorTHEN, June, 1861. Proceed. Acad. Nat.

Sci., Philad., p. 147. :

SHELL attaining a medium size, and having the form of an
elongated, moderately compressed cone, the sides of which con-
verge towards. the apex at an angle of about 14°. Section
elliptical, the greater transverse diameter being to the smaller
as 100 to 80. Surface ornamented with slightly oblique, annu-
lar costa, which are less than the depressions between, and
rather sharply elevated on the smaller half of the shell, but
become gradually obsolete towards the aperture, where they

INVERTEBRATES. 305

are not more widely separated than near the smaller end.
Traces of fine transverse striz are also seen on well preserved
specimens, both between -and upon the coste. (Septa and
siphuncle unknown.) The largest specimen we have seen is
about five inches in length (both extremities being incomplete),
and 1.83 inches in its greater diameter at the larger end, while
its greater diameter at the smaller end is near 0.70 inch.

This species bears some resemblance to O. dactyliophorum, de Koninck
(Ann. Foss. Ter. Carb. Belg., p. 518, pl. xlvii, fig. 1, et xlviii, fig 7a, 7d),
but differs in being more tapering, and somewhat compressed instead of round.
It is also more tapering than O. annulatum, of Sowerby. Prof. Swallow has
described, from the same horizon as this, a similar species under the name 0.
chesterensis (Trans. St. Louis Acad. Sci., vol. ii, p. 98, 1862), but our shell
differs in having fewer and more distant costee, there being generally about
four of them in a space equaling the transverse diameter, while O. chesterensis
has eight in the same space.

Locality and position: Same as preceding.

Genus NAUTILUS, Linneeus, 1758.

(Syst. Nat. Ed., 10, t. i, p. 709.)

NAUTILUS GLOBATUS, Sowerby?
Pl. 24, fig. 54,56.

Nautilus globatus, Sowerby, 1825. Min. Conch., v, pl. 481, fig. 1 and 2.

Nautilus Wrightii, Fummine, 1828. Brit. Anim., p. 230.

Nautilus bistrialis, Puiturps, 1836. Geol. Yorksh., 11, p. 232, pl. 17, fig. 20 and 28.

Nautilus subglobosus, Mrex and WortTHeEN, Oct., 1860. Preceed. Acad. Nat. Sci.,
Philad., p. 469.

SHELL rather under medium size, subglobose, broadly round-
ed over the dorsum; umbilicus (in internal casts) rather small,
deep, and conical, or with nearly vertical sides; volutions about
three, increasing rapidly in size, particularly in breadth, deep-
ly embracing, subangular around the margins of the umbilicus
on each side; outer chamber forming about half of one volu-

= Serr. 19, 1866,

306 PALAONTOLOGY OF ILLINOIS.

tion; septa rather deeply concave, with outer margins nearly
straight in passing over the dorsum, where they are separated
by spaces a little less than one-fifth their own greater transverse
diameter; aperture transversely lunate or reniform; lip deeply
sinuous on the dorsal side (not represented quite deep enough
in our figure); siphuncle small, central. (Surface unknown.)
Greatest diameter, 2.11 inches; height, 1.72 inches; breadth ©
of aperture, 2.06 inches.

At the time we proposed the name JV. subglobosus for this form, we had not
access. to Sowerby’s figures of his VV. globatus, but made our comparisons with
Prof. de Koninck’s figures of a Belgian shell referred by him to Sowerby’s
species, (Anim. Foss. Carb. Belg., pl. xlvii, fig. 11a@and110.) From the form
represented by Prof. de Koninck, our shell differs so materially, that we could’
have no doubt in regard to its being specifically distinct, as it expands much
more rapidly towards the aperture, and has a smaller umbilicus; while it shows
‘no traces of the transverse ridges or costze, forming so conspicuous a feature in
the figures given by Prof. de Koninck. On comparing our shell with Sowerby’s
original figures, however, in connection with Prof. McOoy’s description of JV.
globatus, we can scarcely doubt the propriety of referring it to that species.
The only essential difference seems to be in the size of the siphon, which in
our shell is small, while McCoy describes it as being large in NV. globatus The
differénce in this character may not, however, be so great as to constitute a relia-
ble specific distinction.

Locality and position: Chester, Illinois; Chester group of the Subcarbonif-
erous series.

NAUTILUS CHESTERENSIS, M. and W.
Pl. 24, fig. 4a, 40.

Nautilus chesterensis, Munk and WortHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,

Philad.; p. 469.

SHELL under medium size, subglobose, rounded over the
dorsum and sides; umbilicus (in casts) small and deep, with
nearly vertical walls, probably almost closed in adult speci-
mens retaining the shell, apparently showing very little of the
inner whorls; volutions about three, increasing moderately in

INVERTEBRATES. 307

size, deeply embracing, abruptly rounded, or subangular around
the umbilicus; septa not very deeply concave, arching slightly
forward in crossing over the dorsum, where they are separated
by spaces a little less than one-fourth their own transverse
diameter; siphuncle very near or quite central; aperture trans-
versely reniform, being modified by the inner whorls. (Sur-
face unknown.) Length or greatest diameter, about 2.46
inches; height, 2.05 inches; breadth near the aperture, 1.70
inches; breadth of umbilicus (in cast), about 0.50 inch.

At a hasty glance this and the last described species might be confounded
by a careless observer; but it will be seen by comparison, that the form now
before us is much more compressed, and has a smaller umbilicus; while its
whorls are proportionally deeper in the direction of the greater diameter of the
shell, and not near so angular around the umbilicus on each side.

Locality and position: Same as last.

Sunaznus ENDOLOBUS, M. and W.

(evdoy, within ; ofoc, a lobe.)

(Proceed. Acad. Nat. Sci., Philad., Dec., 1865, p. 259.)

SHELL compressed or subdiscoidal; umbilicus wide and show-
ing all thé inner turns; volutions more or less rounded, and
without longitudinal furrows or ridges, but slightly embracing ;
septa bent backward on the inner side, so as to form a kind of
funnel-shaped ventral lobe, like we see in Tretoceras, excepting
that it is not so deep. Siphuncle central, or between the mid-
dle and the outer side.

The type of this subgenus differs from other large paleeozoic Nautilii, with a
wide, open umbilicus and merely contiguous or moderately embracing whorls,
in haying the septa on the inner side bent backwards, so as to form a shallow
kind of inner or ventral lobe. It is probable that Montfort’s name Bisiphites,
which was proposed for a large fossil shell, apparently of Carboniferous age,
may be synonymous with our Endolobus, as he described his type as having two
siphons, one nearly central and the other near the inner side, while it would be

308. PALZONTOLOGY OF ILLINOIS.

very easy for such an observer to mistake the lobe we have mentioned for a second
siphon, when filled with strony matter. At any rate, that he was mistaken in
regard to the existence of two siphons none will doubt. Even in case his type
has, however, the internal structure of our shell, we think his name should not
be retained, as it implies a direct contradiction of fact. — ;

NaAvTiLuUS (ENDOLOBUS) SPECTABILIS, M. and W.

Pl. 25, fig. la, 16.
Nautilus spectabilis, Mnrx and WortueEn, October, 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 469.
Nautilus (Endolobus) peramplus, Mrnx and Worturn, December, 1865. Ibid., p. 259.

SHELL attaining a very large size, compressed subglobose ;
umbilicus rather deep, about as wide as the dorso-ventral
diameter of the outer volution, and showing about three-fourths
of each inner turn. Whorls three to three and a half, increas-
ing rather rapidly in size, broadly rounded over the dorsal or
outer side, and more narrowly round on each lateral margin,
where the greatest prominence is a little within the middle;
lateral margins each provided with a row of large, broad, de-
pressed or undefined subnodose prominences, about fourteen of
which may be counted on each side of the last turn; from these
rows of nodes or mammillary protuberances, the inner side of
each whorl rounds abruptly into the umbilicus, and is provided
along the middle with a moderately deep, rounded concavity
for the reception of each succeeding inner turn. Septa deeply
concave on the side facing the aperture ; separated by intervals
measuring on the dorsal side, more than one-third the dorso-
ventral diameter of the whorls at the point of measurement,
passing nearly straight over the broad periphery, and with a
very slight forward curve across the sides; while on the lobed
inner concave side they are rather shallow, and more or
less funnel-shaped. Siphon placed rather more than its own
breadth nearer the inner than outer side. Surface of cast
smooth. Greatest diameter, 23 inches; transverse diameter,

fet apc

INVERTEBRATES. 309

12 inches; dorso-ventral diameter of inner whorl, 8 inches;
breadth of umbilicus, 8.50 inches; circumference around the
periphery, 4 feet, 8 inches. ;

The specimen from which our figures of this species were drawn, natural size,
we now know to be a young shell, or merely the inner whorls of an adult. Owing
to the fact that its last septum is broken on the inner side, the lobe is not visi-
ble, and it was only after recently breaking one of the volutions across at another
septum, that we discovered its existence in this specimen. Hence on the dis-
covery of the great ponderous shell in which this lobe was first discovered, and
from which the foregoing description and measurements are given, its specific
identity with that figured on plate 25 was not suspected, and another name was
proposed for it. As we now know that they argree in this character, and they
present no other essential differences aside from mere size, and very slight
peculiarities of form, such as are doubtless due to differences of age, we cannot
longer regard them as being specifically distinct.

Perhaps this species is most nearly allied to NV. tuberculatus of Sowerby; at
any rate it resembles more nearly Phillips’s figure of that species, given in his
Geol. Yorkshire, vol. i, pl. 29, fig. 29, than any other form with which we are
acquainted. It differs, however, in having its whorls broader, and ‘the most
prominent part of their sides, with their nodes, placed nearer the umbilicus;
while in a profile view it will be at once distinguished by having its periphery
prominently rounded, instead of nearly flat. In addition to this, we have no
evidence that NV. tuberculatus has a lobe on the inner side of the septa.

Locality and position: Gravel creek, and other localities in Randolph county,
I)linois; Chester division of the Subcarboniferous series.

INVERTEBRATE FOSSILS OF THE COAL MEASURES,

RADIATA.
CRINOIDEA.
Genus CYATHOCRINUS, Miller, 1821. (See page 175.)

CYATHOCRINUS? SANGAMONENSIS, M. and W.
Pl. 26, fig. la, 10.

Cyathocrinus? sangamonensis, MnEK and WorTHEN, June, 1861. Proceed. Acad. Nat.
Sci., Philad., p. 392.

Bopy large, semiovate beneath the summit of the first radials,
composed of rather thin plates, which are smooth, somewhat
convex, and connected by strongly defined, subpunctate sutures.
Base moderately prominent, rounded below, pentagonal in out-
line, and equaling about half the breadth of the body, formed
of equal, regularly pentagonal pieces, which are a little wider
than long; columnar facet round, deep and about one-third as
wide asthe base. Subradial pieces large, as wide as long, three
of them hexagonal, and two heptagonal, with unequal sides.
First radials wider and shorter than the subradial plates, about
twice as wide as high, pentagonal, and of nearly equal size
and form; the superior side of each horizontally truncated,
and considerably longer than either of the basal margins,
which are longer than the vertical, lateral edges. First anal

INVERTEBRATES. 311

plate of moderate size, longer than wide, and projecting some-

what above the summit of the first radials; apparently irregu-

larly heptagonal or octagonal in form, with two or three short
_sides above, for the reception of smaller pieces, and supported |
upon the short, truncated, upper side of one of the subradial

plates, while on either side it connects with the first radials,

excepting on the right inferior sloping margin, which rests

against a large, oblong, subanal piece. This latter plate is

larger than the true anal piece above, and rests between the

‘superior sloping sides of two of the subradial plates; while its
upper oblique side supports one of the inferior sloping sides of

the first radial on the right of the anal piece. Upper trunca-

ted side of the first radial plates, much thickened within, and

provided, near its outer margin, with a distinct, longitudinal

Fig. 31. furrow, inside of which is

a transversely crenulated
ai ridge, with an indentation
in the middle; inside of

this ridge the margin pro-

jects considerably, curves

OO ea a little upwards, and has

as Gs a distinct notch or sinus

ob in the middle. Height to

the top of first radial pieces

on the longer side, about
1 inch; greatest breadth,

Ku 1.38 inches; breadth of
_ base, about 0.67 inch; di-

Cyathocrinus sangamonensis. (Nat. size) ameter of columnar facet,
This diagram shows basal, subradial, first radial, and 7
anal eee ; = Feoe 0.25 inch.

We are in some doubt in regard to the generic relations of this species, not
having seen any specimens showing the arms, summit, or any of the radial
spieces above the first. It differs from the characteristic species of the genus
Cyathocrinus, in having a large, subanal plate intercalated between its subra-
dials, and one of the first radial pieces. It also differs in having two of its

312 PALEONTOLOGY OF ILLINOIS.

subradial plates heptagonal in outline, instead of only one, as is usual in that
genus. So far as can be determined from our specimen, there seems to be
almost, if not quite, as much reason for placing it in the genus Poteriocrinus.
Yet it differs from the typical species of that genus, in having none of its first

radial plates resting directly upon a truncated upper side of one of the subra-

dials, as well as in having but one, instead of two, anal plates between the first
radials. We suspect when better specimens are found, showing all its charac-

ters, that it may prove to belong to an undescribed genus. It is not nearly —

related to any other species with which we are acquainted.

Locality and position: Sugar Creek, Sangamon county, Illinois; upper part
of Coal Measures.

Genus ZEACRINUS, Troost. (See page 185.)

ZEACRINUS Discus, M. and W.

Pl. 26, figs. 3a, 35.

Zeacrinus discus, Mrxrx and Worrtuen, September, 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 390.

Bopy, below the summit of the first radial pieces, much de-
pressed, or subdiscoidal, about three times as wide as high,
composed of smooth, very slightly convex plates, which are
connected by moderately distinct sutures. Base very small,
flat and pentagonal; columnar facet equaling about two-thirds
the diameter of the base, round, concave, and marked by dis-
tinct radiating striz; perforated by a round, minute, central
aperture. Subradial plates extending nearly horizontally out-
ward from the base, so as to form a distinctly pentagonal star-
shaped disc, all curving a little upwards towards their outer
extremities; three of them pentagonal and two hexagonal,
each of the latter having one angle slightly truncated by the
anal pieces. First radial plates about twice as large as the
subradials, rather more than half as long as wide, pentagonal,
and all transversely truncated above, the upper side being
longer than either of the others. Second radials and succeed-
ing parts above, unknown.

eri lew) 4.0 alll ee oni

=

INVERTEBRATES. . Br

First anal plate nearly twice as long as wide, pentagonal in
form, somewhat wedge-shaped, and deeply inserted between
one of the first radials and one of the subradial pieces. Above,
it connects on the left with another piece of about its own size,
resting upon a short truncated side of one of the subradials,
and connecting on the left with one of the first radials, while
its upper truncated side supports a third piece, the exact form
of which cannot be made out in our specimen. Both of the
anal pieces of the second range project more than half their
length above the summit of the first radials on each side of
them. Height, to the summit of the first radial plates, 0.14
inch; breadth, 0.50 inch; breadth of base, 0.14 inch.

This species appears to be allied to Oupressocrinus impressus, of McCoy
(British Pal. Foss., pl. 3, D, fig. 2), which is a true Zeacrinus, but differs in
presenting a subhexagonal instead of a circular outline, as seen from below.
It also differs in having a smaller columnar facet, which only conceals a little
more than half of each basal plate, while in Z. wmpressus it seems to hide
the basal pieces entirely. ‘There are likewise some differences in the.arrange-
ment of the anal pieces from those of McCoy’s figure, but this is, as we believe,
due to his figure having been drawn on the stone without reversing the arrange-
ment of the parts.

Our species seems to be also related to Zeacrinus mucrospinus, of McChesney
(New species palzeozoic fossils, p. 10, pl. 4, fig. 7), but it differs in having
proportionally much shorter subradial pieces, while the form of its first anal
piece is quite different. Its first radials likewise differ in being pentagonal
instead of heptagonal. Whether or not its second radial pieces are produced in
the form of long spines, as in Z. mucrospimus, we are unable to say, not having
seen any specimens showing the second radials. From its analogy, however,
to the species described by Prof. McChesney, we suspect it will be found to
possess similar appendages.

Locality and position: Same as last.

——Ai() Supr. 20, 1866.

314 PALZONTOLOGY OF ILLINOIS.

ZEACRINUS? CRASSUS, M. and W.
Pl. 26, fig. 2a, 20.
Cyathocrinus? crassus, Muux and WortueEn, September, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 392.
Bopy below the summit of the first radial plates, depressed
basin-shaped, about twice as wide as high, rounded below, and

composed of thick, smooth, somewhat convex plates, which are
joined by well defined, subpunctate sutures. Base very small,

or about one-fourth the breadth of the body, pentagonal, deeply

concave, and apparently nearly hidden by the column. Sub-
radial pieces wider than high, extending at first nearly hori-
zontally outwards from the base, after which they curve up-
wards; four of them are hexagonal, and one, on the anal side,
heptagonal; the angle at the middle of the base of each being

very slightly salient. First radial plates larger than the sub-

radials, nearly twice as wide as high, horizontally truncated
above, and nearly or quite straight on the upper side, which is
longer than the inferior sloping edges; four of them penta-
gonal, and one, on the left of the anal pieces, hexagonal. First
anal piece nearly as large as one of the subradials, pentagonal
in form, and resting between the superior sloping sides of two
of the subradial plates, while its lateral margins connect with
two of the first radial pieces. Second anal piece, about one-
third as large as the first, upon the upper, short, truncated side
of which it is supported; longer than wide, pentagonal or hex-
agonal in form, and extending near half its length above the
margins of the two first radials, with which it connects on
each side. Remaining parts unknown. Height, from base to
summit of first radials, 0.45 inch; breadth, 0.92 inch; breadth
of base, 0.24 inch.

;
bs
- $
ij
;
:

INVERTEBRATES. : 315

Fig. 32. This species seems to be closely related, so far as
our specimens show its structure, to some of the

forms referred by Prof. de Koninck to his genus
Hydreionocrinus (Mem. de Palzont., Bull., Acad.

3 Roy. Belgique (2) tome iii, p. 22). Indeed, if
~ his H. scoticus, of that paper, really belongs to

O54
( that genus, we can scarcely doubt the propriety of
ia calling our species Hydr. crassus; but as neither
our crinoid nor the species scoticus are known to
a possess the remarkable structure of the upper parts

- seen in Hydr. Woodianus, the type of that genus,

we are left in doubt on this point.

Zeacrinus ? crassus.—(Nat. size.) C 8
Diagram showing the small basal Locality and position: Avon, Fulton county,

ieces, the lar F se
ends firstra- T)].; lower part of Lower Coal Measures.

Genus ERISOCRINUS, M. and W.

Synon.—A Crinoid near Encrinus moniliformis, Marcou, 1864. Bull. Geol. Soc. France,
tome xxi.
Erisocrinus, Menx and WortHEN, March, 1865. Am. Journal Sci., 2d series,

vol. xxxix, p. 174. P
Philocrinus, Mnux and WortHEN, May, 1865. Ibid.; (not de Koninck, 1863.)
Erisocrinus, Manx and WortHeEN, Aug., 1865. Ibid.; p. 148.

Generic formula.—
Basal pieces, 5.
Subradials, 5. > United to form the walls of the body.
Radials, 5+ 2.
Anal and interradials, 0.
Arms and vault unknown.

BASAL pieces very small, forming a pentagonal flattened or
concave disc, or alow cup. Subradials larger, not varying in
form, and all alternating with the basal pieces. First primary
radial pieces considerably larger than the subradials, with
which they all alternate; all connecting laterally, so as to leave
no spaces for anal or interradial pieces, and truncated their
entire breadth above for the reception of the next range of
pieces. Second radials of near the same size as the first, and
like them, connecting all around—supporting on their superior
sloping sides the first divisions of each ray.

516 PALHONTOLOGY OF ILLINOIS.

Of this curious type we only know the body below the summit of the second
radial pieces. In the structure of this part of the body, however, it differs
from the characters assigned to any known genus of Crinoids (excepting Cup-
ressocrinus, from which it differs in other characters to be hereafter mentioned),
in having five basal pieces alternating with five subradials, which likewise alter-
nate with the radials, while all these pieces are so connected laterally as to form a
cup, without leaving any spaces for anal or interradial pieces. In several respects
it closely resembles Hncrinus, but differs from the descriptions of that genus
given by all the authors we have been able to consult, in having a distinct series
of subradial pieces between the radial and basal pieces. It also differs from the
normal structure of that genus in having but two primary radials in each ray. In
a specimen of EHncrinus, belonging to Smithson’s private collection (since de-
stroyed by the fire at the Smithsonian Institution), examined by one of. us, in
the centre of the cavity occupied by the end of the column, five exceedingly
minute rudimentary pieces were visible by the aid of a magnifier within the range
generally regarded as the true basal pieces. If these were developed so as to
assume the character of true basals, then those usually regarded as such would
become subradial pieces, in which case our Crinoid would present no essential
difference, unless it may be in the other parts yet unknown. As Lncrinus is,
however, always described as having the radial series resting directly upon the
basals, it is exceedingly improbable that the minute points mentioned above
were ever developed so as to become properly basal pieces. Hence we are un-
prepared to admit the existence of the genus EHncrinus in our Carboniferous
rocks, and believe a new genus should be admitted for the form under consid-
eration. It is also highly probable that when we can compare the entire
structure of this Carboniferous type with that of Hncrinus, it will be found to
present other important differences.

A fine specimen of Cupressocrinus abbreviatus of Goldfuss, from the Hifel,
now before us, shows that genus to agree exactly with Hrisocrinus in the struc-
ture of the body up to the second primary radials, above which it differs
remarkably in having the rays each composed of a single series of pieces, and
soldered together all the way up; while in Erisocrinus each ray seems to bifur-
cate to form free arms on the second radials. Cupressocrinus also differs in
having a quadrangular central canal running the entire length of the column.

Soon after publishing the description of this genus, we were led by its simi-
larity to a genus described by Prof. de Koninck, under the name Philocrinus,
from the Carboniferous rocks of India, to believe it identical, and ranged our
species under that name. Later comparisons have caused us, however, to doubt
the correctness of this conclusion. Jf there is no mistake in regard to Philo-
crinus being without a range of subradial pieces, then the two types would be
clearly distinct. The fact, however, that the basal pieces in Hrisocrinus are

INVERTEBRATES. SLT

small, and might be easily overlooked in imperfect specimens, taken in connec-
tion with the fact that the lowest range of pieces represented in Prof. de Ko-
ninck’s figure, if true basals, would have to present a singularly elongated
cuneiform outline, leads us to suspect there may be another range of small true
basal pieces below them, but not visible, from some imperfection in Prof. de
Koninck’s specimen. If so, then the identity of our Crinoid with his Indian
type would be complete. Until this question can be satisfactorily settled, how-
ever, we have concluded to retain our name Krisocrinus for the American type.
Should they prove identical, however, of course Prof. de Koninck’s name will
have to take precedence, since it has priority of date.

So far as we know, this genus is confined to the Carboniferous rocks. Mr.
Marcou thought its close analogy to Encrinus indicated that certain Coal Meas-
ure rocks in which he found it in Kansas, belong to the part of the Permian
series he calls “Dyas.” He was, however, at that time, not aware of the fact,
that the same species he found in Kansas, and two others of the same genus,
occur in the Coal Measures of Illinois, curiously enough at the same time re-
ferred by him to the Subcarboniferous.

ERIsocrinus tyrus, M. and W.

Brisocrinus typus, Merk and Wortuen, March, 1865. Am. Jour. Sci., vol. xxix, p. 174.
Philocrinus pelvis, MeuEK and Wortuen, May, 1865. Ib., p. 350.

Erisocrinus nebrascensis, Mprx and WortTHEN, March, 1865. Am. Jour. Sci., vol. xxix,
page 174.

Bopy below the summit of the radial pieces basin-shaped,
rounded below, and obscurely subpentagonal in outline as seen
Fig. 33. from above or below; composed of thick,
smooth, slightly convex plates. Basal
pieces small, about half hidden by the

a column, sometimes sunken, and all penta-
a\ gonal in form; subradials six or seven

~ times as large as the portion of each basal
\Q) ‘A piece not hid by the column, all equally
le aa ee ne hexagonal; first radial pieces four or five
Diagram showing the form ana times as large as the subradials, wider than

arrangement of the basal, subra-

dial, and first and second radial |
ie sania oe ceca aa long, and all equally pentagonal, support-

en eae ing on their broadly truncated upper edges

318 PALZONTOLOGY OF ILLINOIS.

the second primary radials, which are of very nearly the same
size and form as the first, but Fig. 34.
have their sloping sides above,

a b
instead of below, while the ol j
perior edge of each supports on Z
its upper sloping side the first \_ C7

brachials, or a series of second- Pie. ile la es
ary radials, yet unknown. Sur-_ @ Side views; (0) view of under side; (c) view of

upper side ; showing the great thickness of the plates,
and the articulating surfaces for the reception of the

face smooth. The foregoing second radials.
cuts of this species represent it natural size.

Farther comparisons with some additional specimens, lead us to believe the
form from Bellevue, Nebraska, described by us under the name Z. nebrascensis, is
as we at first suspected, but a variety of this species, with a deeper cup, pro-
duced by having its subradials proportionally larger.

Locality and position: Coal Measures, near Springfield, Sangamon county,
Illinois.

ERISOCRINUS CONOIDEUS, M. and W.

Erisocrinus conoideus, Merk and WortnHen, Aug., 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 150.

ai Bopy small, below the summit of the first
; \O/ radials truncate-obconic, nearly twice as wide

as high; basal pieces a little wider than long,

O gS pentagonal as seen projecting beyond the col-
[) “a5 \ umn, and forming together a small low cup,
) sie O with diverging sides; subradials near three
Se times as large as the basal pieces, a little wider
Erisoorinus considers, 020 long, and all hexagonal; first radial pieces
(a) Nat. size, side view of half as long as wide, about twice as large as

body. (6) Diagram of plates s
op body, enlarged twodiam- the subradials, and all broadly truncated on

eters,
the same horizontal plane above, for the reception of the second
radial pieces. Surface smooth; sutures linear, not impressed ;

plates not convex. Column, and all the parts above the first

:
:
:
|

INVERTEBRATES. 319

radial pieces, unknown. Height, to summit of first radials,
0.20 inch; breadth of do., 0.34 inch.

This species will be at once distinguished from young specimens of the last,
of its own size, by its obconic, instead of basin-shaped cup. From Professor
de Koninck’s species cometa (in case our species should really belong to his ge-
nus), it will be distinguished specifically by the less convex outline of the sloping
under sides of its cup, as well as by its shorter and proportionally wider first
radial pieces. It will of course have to take the name Philocrinus conoideus, in
case Professor de Koninck’s species should prove generically idertical with
these American species.

Locality and position: Springfield, Illinois; Upper Coal Measures.

ERISOCRINUS TUBERCULATUS, M. and W.

Erisocrinus tuberculatus, MnEK and WorTHEN, August, 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 150.

Although we only know this fine species from its detached plates, these agree
so exactly in form with the corresponding parts of our Erisocrinus typus from
the same beds, that scarcely a doubt can be entertained in regard to their be-
longing to the same genus, while they differ so remarkably in their surface
characters as to be distinguished at a glance, specifically, from that or any
other Crinoid known in our Coal Measures. This difference consists in their
entire external surface being covered with regularly disposed, narrow, promi-
nent tubercles, instead of being smooth.

Of these tubercles there are, on a first radial plate measuring 0.90 inch in
breadth, and 0.54 inch in height, about thirty in number, arranged so as to
form two rows of about eight each, ranging parallel to the inferior sloping mar-
gins, and one row of about eight along the superior margin. Between this

- latter row and those below, there are usually a few tubercles, either isolated or
forming a third transverse row. There is likewise usually one or several others
at the lower middle angle outside of the regular rows. This arrangement of
the tubercles into rows is not, however, always obvious at a first glance, but a
tendency to such a disposition can always be seen.

On the second radials the tubercles are arranged in a single row along the
lower and each superior sloping margin, with one or more in the middle
between the rows. In the articulating or connecting surfaces of the radial
plates, we observe no differences between these pieces and those of the corre-
sponding parts of LE. typus.

Some of the plates indicate a transverse diameter of 1.40 inch for the entire

body.

520 PALHONTOLOGY OF ILLINOIS.

If our proposed genus LHrisocrinus is, as we have suspected, identical with
Philocrinus of Koninck, the name of this species will have to be written Philo-
crinus tuberculatus.

Locality and position : Upper Coal Measures; Sugar creek, Sangamon county,
Illinois, and near Brighton, Jersey county, Illinois.

MOLLUSCA.

BRACHIOPODA.
Genus PRODUCTUS, Sowerby, 1812.
(Min. Conch., i, p. 153.)
Propuctus NANuS, M. and W.

Pl. 26, figs. 4a, 46, 4c, 4d.
Productus nanus, Mpzxk and WortHEN, October, 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 450.

SHELL very small, nearly hemispherical; hinge about equal-
ing the greatest breadth; anterior side regularly rounded, sides
intersecting the hinge nearly at right angles. Ventral valve
gibbous, without any traces of a mesial sinus; ears triangular,
convex and moderately distinct from the swell of the visceral
region; umbo ronvex, incurved, and apparently extending
slightly beyond the hinge line. Surface ornamented by com-
paratively. large, rounded, radiating coste, which are rather
wider than the grooves between on the convex part of the
valve, but suddenly bifurcate, and increase by the intercala-
tion of others, around the anterior and antero-lateral margins;
entire surface crossed by numerous very fine concentric striz;
visceral region also marked by moderately distinct, rather reg-
ular concentric wrinkles, while the bases of a few scattering
spines may be seen on the anterior slope. (Dorsal valve
unknown.) Length, 0.37 inch; breadth, 0.44 inch; convexity,
0.25 inch.

:
:
|

eg Ce

INVERTEBRATES. 321

This little shell resembles P. mwricatus, of Norwood and Pratten, but is
smaller, and has a more convex yentral valve. It also differs from all the spe-
cimens of that species we have seen, in the peculiar sudden bifurcation of its
costze on a somewhat raised band around the free border of its ventral valve.

Mr. Thomas Davidson, of London, the highest authority on the fossil
Brachiopoda, after examining specimens of P. wabashensis, P. splendens, and
P. muricatus (N. and P.), from Illinois, pronounces them almost certainly all
identical with P. longispinus, of Sowerby; and since we have seen his figures
of the varieties of that species in his Monographs of the Carboniferous Brachio-
poda of England and Scotland, we are inclined to adopt his opinion.
Although none of these varieties agree with the little shell under consideration,
we should not be surprised if more extensive collections would bring to light
intermediate gradations connecting it with P. longispinus, Sowerby.

Our figures 4a, 46 and 4c, of this species, show the divisions of the costz
around the front too fine, and crowded; the enlargement, figure 4d, gives a
correct idea of their appearance under a magnifier.

Locality and position: Jefferson county, lowa; Lower Coal Measures.

Genus SYNTRIELASMA, M. and W.

Synon.—Choristites (sp.), FiscHEr, 1825. Programme sur la Choristites.

Terebratula (sp.), d’OrBieNy, 1842. Voyage dans Amer. Merid., vol. 3, p.
42; (not Miller and others).

Spirifer (sp.), Haun, 1852. Stansbury’s Report Exp, to Great Salt Lake, p.
409; (not Sowerby).

Orthis (sp.), SALTER, 1861. Jour. Geol. Soc., London, vol. xvii, p. 64; (not
Dalman),

Syntrielasma, Mex and Wortuen, Dec., 1865. Proceed. Acad. Nat. Sci.,

Philad., p. 277.

SHELL thin, gibbous or subglobose, in adult specimens; valves
articulated by teeth and sockets, in the typical species nearly
equally convex; hinge line straight and very short; area small,
partly common to both valves, but higher in the ventral valve,
where it is divided by a triangular, open foramen; beaks
incurved, subequal. Surface radiately striate, and ornamented
with large, radiating plications, which form deeply interlocking,
angular projections at their terminations in the margins of the
front—one of the plications a little larger than the others on the

middle of the dorsal valve, so as to assume somewhat the char-
th Sept. 21, 1866.

322 PALEHONTOLOGY OF ILLINOIS.

acter of a mesial fold, opposite a corresponding sinus of the
other valve. —

Socket plates of the dorsal valve much as in Orthis, being
quite prominent and very diverging, with a linear, longitu-
dinal, mesial ridge between them. - Dental laminz of the ven-
tral valve, thin, prominent, very closely approximate at their
connection with the bottom of the valve, and with a similar
mesial septum, extending as three nearly parallel plates to the
middle of the valve. (Muscular and visceral impressions
unknown.) Shell structure distinctly punctate.

The typical species of this group (Spirifer hemiplicatus, Hall), has the gene-
ral external appearance, when well developed, of a subglobose Orthis, of the
section usually described as resupinate, excepting that it is provided with afew
very large plications, one of which forms a mesial fold on the dors] valve.
Internally, however, we observe a marked difference in the nature and arrange-
ment of the dental laminz, which at their connection with the bottom of the
valve, are closely approximate, and with a prominent mesial septum, extended
nearly parallel to each other, far forward. The close approximation of these
plates, indicates a different arrangement of the cardinal and other muscles,
from that of Orthis. In the latter genus, slight ridges usually extend forward
from the dental laminz, but so widely separated as to leave a large depression
between, for the attachment of the muscles. In the type under consideration,
the plates that represent these ridges in Orthis, are so close together that it is
difficult to understand how any muscles could have been attached to the bottom
of the valve between them. ‘This will be better understood when we state that
these plates are rarely more than the tenth of an inch apart at their connection
with the bottom of the valve, and in some examples, where the shell is as much
as nine-tenths of an inch in diameter, the space between these laminze is no
where more than 0.06 of an inch across, and at least one-fourth of this narrow
space is occupied by the mesial septum.

Fig. 36.
b

Syntrielasma hemiplicata.

The above cut, a, shows the dental lamine (J, 1), and mesial septum (mm), as seen in a section across
the beak of the ventral valve. Figure b, represents the laming (/), as seen in a side view; also the
socket plates (s) in the same way. Fig. (c) is an outline posterior view, of a smaller specimen, show-
ing the small area and foramen.

¥
i

INVERTEBRATES. 323

This group will, we think, almost beyond doubt, include two South Ameri-
can shells, described by d’Orbigny, from the Carboniferous rocks of Bolivia,
under the names Terebratula Andii and T. Gaudreyi. Indeed we have some
suspicions that his 7. Andi may even be specifically identical. with the type of
our group. D’Orbigny’s figures appear to represent a more coarsely striated
shell than ours, and show the plications extended farther towards the beaks; .
but Mr. Salter refers to that species, under the name Orthis Andii, a shell col-
lected by David Forbes in the Andes (Quart. Jour. Geol. Soc., xvii, p. 64, pl.
iv, fig. 3), that agrees almost exactly in form, as well as in the plications, with
that before us. It shows, however, no radiating striz, but they were probably
in part obliterated by wearing, for so careful an observer as Mr. Salter would
not refer a perfectly smooth shell, to as distinctly striated a species as d’Orbig-
ny’s figures represent. We also regard Choristites Lamarckii, of Fischer,=
Spirifer Lamarckii, Murchison, de Verneuil and Keyserling, (Geol. Russ , ii,
pl. vi., fig. 8a, 8b], as most probably another example of this genus. The
distinguished authors of the Geology of Russia, were evidently in doubt in
regard to the affinities of the last mentioned species, of which they had no per-
fect specimens, and state that they would have referred it to Terebratula, had
it not been for the fact that Fischer described it as having a straight hinge,
and a triangular foramen.

So far as we know, this genus is strictly confined to the Carboniferous rocks,
and includes but few species. It belongs to the Strophomenidx, near Orthis.

We have not had access to Fischers’s work, and consequently do not know
what characters he assigned to his proposed genus Choristites, nor what species
was regarded by him as its type. From the species included under that name
by him, however, it seems manifest he intended it for the same group for which
Sowerby’s older name Spiri/er, is now retained. We-also have the impression
that Spirifer mosquensis was his typical species of Choristites. Should it be
the fact, however, that the species Lamarckti was the type of his genus, and
that it has the internal characters of our genus, it would be necessary to retain
his name Choristites, for the group under consideration. If so, we shall have
no objection to abandoning our name, and calling the American species Choris-
tites henviplicatus, for we shall always yield cheerfully to the law of priority.

SYNTRIELASMA HEMIPLICATA, Hall (sp).

Spirifer hemiplicatus, Hauu, 1862. Stansbury’s Report Great Salt Lake Exp., p. 409,
pl. iv., fig. 3a, 30. ;
SHELL in young examples, moderately convex, and resem-
bling a “resupinate” Orthis, in adult specimens often so gib-

324 PALEONTOLOGY OF ILLINOIS.

bous that the convexity of the two valves is greater in the
middle than the diameter in any other direction. Hinge line
Vig. 37. only about equaling half the

“ transverse diameter of the
valves, and owing to its short-
ness, and the convexity of the
shell, imparting little or no an-
eularity to the lateral slopes at
its extremities. Dorsal valve

Syntrielasma hemiplicata. ‘

Fig. a, dorsal view, natural size, with a part of somewhat more convex than
the shell removed to show the diverging socket
plates; fig. b, ventral view of same, with a part of

shell removed to show the three nearly parallel the other, and. very strongly

lamins, as seen in the internal cast,

arched ; umbonal region gib-
bous, and often in adult shells-projecting beyond the beak of the
opposite valve; beak strongly incurved, so as to bring its apex
under the beak and nearly against the area of the other valve;
area about half as high as in the other valve, and distinctly in-
curved with the beak. Ventral valve convex; beak only moder-
ately prominent, and arched or more or less incurved; area small,
about one-third as high as wide, not always very distinctly defin-
ed, arching with the beak; its triangular foramen scarcely as wide
as high. Surface of both valves ornamented with rather fine,
regular, crowded radiating strie, and a few very large radiating
plications, never defined on the umbones, but becoming more
prominent towards the front, where they terminate in deeply
interlocking, angular marginal projections. Of these plications
there are two—rarely three—on each side of the slightly larger
and more prominent one forming the mesial fold of the dorsal
valve; while on the ventral valve there are three—rarely four
—on each side of the mesial sinus. A few zigzag marks of
growth also traverse the anterior and lateral margins of the
valves, parallel to their deeply notched edges. Length of a
medium-sized adult specimen, 0.72 inch; breadth of ditto, 0.74

inch; convexity, 0.75 inch. Radiating strie numbering twelve
to fifteen in 0.10 inch.

2

Le.

INVERTEBRATES. 325

.

It is impossible to confound this interesting shell, for a moment, with any
other known form of our entire Palzeozoic series. In young examples, as
already stated, it is much lesssconvex, and presents somewhat the appearance
of an Orthis, its plications being at that stage of its growth rounded, very ob-
scure, and only indicated near the front. In larger specimens they are much
more prominent, and like the sinuses between, more angular, while the valves
are greatly more convex and more arched ; the beaks are also, in these larger
specimens, more incurved, and the area less apparent.

Worn specimens, or internal casts of adult examples, sometimes resemble
some of the small globose species of the genus Pentamerus, particularly such
species as that described by Professor Hall (Jowa Report, vol.i, part ii, p. 514),
from the Hamilton group, under the name P. occidentalis,* but the more dis-
tinct costz and radiating striz readily distinguish our shell, where the surface

_is intact. It is also a resupinate species, so that its dorsal valve corresponds

to the ventral, in the Pentamerus alluded to.

In examining the striz under a magnifier, especially on the sides of the
valves, we notice that oceasionally one of them increases slightly in size fora
short distance, to a point where there seems to be a minute opening, as if it
had been the base of a tubular hair-like spine. Immediately below each of
these the striz are each slightly less prominent. These little openings are
greatly larger and more scattering than the punctures of the substance of the
shell, which, however, are comparatively large, scattering, and easily seen with
a good pocket lens on exfoliated surfaces.

Locality and position: Twelve miles north of Vandalia, Illinois; Upper Coal
Measures. This is the only locality at which this shell has been found in IIli-
nois. It occurs, however, at the same horizon in Hastern Kansas, Northern
Missouri and Western Iowa, where it is, as in this State, associated with nearly
all the common Upper Coal Measure species of the West.

* As Prof. Hall had previously applied the name P. occidentalis to another species,
from Canada, in the second volume of the Paleontology of New York, p.341, it becomes
necessary, in order to prevent confusion, that our Hamilton group species of the West
should receive another name. We would therefore propose to call it Pentamerus gale-
atiform, from its resemblance to smooth specimens of P. galeatus.

326 PALAONTOLOGY OF ILLINOIS.

LAMELLIBRANCHIATA.
Genus AVICULOPECTEN, McCoy, 1852.

(Ann. and Mag. Nat. Hist., vii. p.171.)

AVICULOPECTEN Coxanus, M. and W.
Pl. 26, fig. 6a, 6d.

Aviculopecten Coxanus, Merk and WortHeEn, October, 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 453.
Comp. Aviculopecten rectilaterarius (—Avicula rectilateraria, Cox), Kentucky Rep.,vol. 3,

De ovile

SHELL (left valve) small, extremely thin, compressed, broad
subovate exclusive of the ears, very slightly oblique; anterior
and posterior margins rounding into the base from below the
ears; base regularly rounded; hinge nearly straight, not quite
equaling the greatest breadth of the valves below, directed
very nearly at right angles to the longer axis of the shell.
Anterior ear of moderate size, triangular, the angle at the ex-
tremity being a little rounded; flattened so as to be quite dis-
tinct from the umbonal slope, and separated from the margin
below by a rather abruptly rounded sinus. Posterior ear of
nearly the same size as the other, but differing in being acutely
pointed at the extremity ; flattened, but not so distinct from
the umbonal slope as the anterior ear; separated from the pos-
terior margin by a regularly rounded, moderately deep sinus.
Beak compressed, scarcely projecting beyond the cardinal mar-
gin, and located slightly in advance of the middle of the hinge;
umbonal slopes diverging from the beak at an angle of about
77°. Surface ornamented by small, simple, depressed and
rigid costz, which alternate in size, the smaller ones dying out
at various distances between the margin and the umbo; cross-
ing all of these are numerous extremely fine, closely arranged
concentric strize. Right valve unknown. Length, or diameter
from the hinge to the basal margin, 0.53 inch; diameter, from

7
|
1

INVERTEBRATES. Bate

the anterior to the posterior margin, 0.51 inch; length of hinge
0.46 inch; convexity of the left valve about 0.05 inch.

In some of its varieties this species seems to approach quite nearly Aviculo-
pecten recti-laterarius, Cox, sp., but it is usually a narrower shell, and always
differs from the published figure of that species in having its ears more dis-
tinct from the umbonal slopes, particularly the anterior one. Its posterior ear
also differs in being sinuate instead of straight, and in terminating in an acute
point, instead of a right angle.

Some of our specimens are as much as one-third larger than that we have
figured, and slightly more oblique, with proportionally larger costz. These
resemble more nearly the shell figured by Prof. Cox, but always differ in having
the margin of the posterior ear distinctly sinuous, and its extremity acutely
pointed.*

Our species also resembles Aviculopecten papyraceus, of Sowerby, but differs
in being less oblique, and in having a more obtuse anterior ear, and simple
costz, as well as a smaller and more deeply sinuous posterior ear.

The specific name was given in honor of Prof. H. T. Cox, of the Kentucky
and Arkansas Geological Surveys.

Locality and position: Adams county, Illinois, in a dark bituminous shale
of the Lower Coal Measures.

AYVICULOPECTEN PELLUCIDUS, M. and W.
Pl. 26, fig. 5a, 55.

Aviculopecten pellucidus, Murex and WortHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,

Philad., p., 455.

SHELL very small, extremely thin and fragile, compressed,
subovate or subcircular, somewhat oblique; hinge margin
straight, less than the greatest diameter of the valves from the
front to the posterior side; ventral margin nearly regularly
rounded ; anterior edge rounded near the middle, and passing
by a slightly oblique curve into the ventral border; posterior
margin most prominent below the middle, sloping obliquely

* In comparing our shell with the figure and description published by Prof. Cox, it is
necessary that the reader should bear in mind that he has inadvertently described the
anterior ear as the posterior, and the posterior as the anterior.

328 PALZONTOLOGY OF ILLINOIS.

forwards and upwards above. Left valve much compressed ;
anterior ear rather small, triangular, flattened and distinct
from the umbonal slope. Posterior ear of about the same size
as the other, flattened and terminating in a rather acute angle;
separated from the posterior margin by a broad, very shallow,
rounded sinus. Beak compressed, located very nearly at the
middle of the hinge. Surface ornamented by very fine, radia-
ting, thread-like strize, which increase by intercalation and are
generally rather smaller than the depressions between; crossing
these are equally fine, regular, less distinct concentric striz.
(Right valve unknown.) Diameter from the ventral margin
to the hinge, 0.36 inch; breadth from the anterior to the pos-
terior margin, 0.35; length of hinge, 0.23 inch; number of
radiating striz in 0.10 inch at the ventral margin, about 12.

This delicate little shell will be readily distinguished from the last by its
smaller size and much finer surface markings, which form a neat cancellated
style of ornament. It is also a more oblique shell, with a rather straighter and
proportionally shorter hinge, and more angular anterior ear.

Locality and position: Same as preceding.

AVICULOPECTEN Konincxu, M. and W.

Pl. 26, fig. 8.

Aviculopecten Koninckii, Munk and WortueEn, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 453.

SuELL large, thick, truncato-subcircular, rather compressed,
wider than long, not oblique, broadly rounded on the pallial
margin, and more narrowly rounded on each side below the
ears; hinge straight, apparently rather less than the greatest
breadth of the valves below, and ranging very nearly at right
angles to the vertical axis of the shell; right valve compressed,
most convex near the umbo, and flattened towards the free
margins; anterior ear having the form of an inequilateral tri-
angle, the anterior side being shorter than either of the others,

INVERTEBRATES. 329

separated from the margin below by an obtusely angular, or
somewhat rounded sinus; posterior ear compressed, longer than
the other, and acutely angular at the extremity, separated from
the margin below by a nearly rectangular notch; beak com-
pressed, small, and not projecting beyond the hinge margin,
located a little in advance of the middle of the hinge; cardi-
nal area inclined over towards the right, and not very wide;
surface ornamented by rather small, straight, obscure, de-
pressed, radiating costee, crossed by nearly obsolete marks of
growth. Left valve more convex, and marked by more promi-
nent costze, which are crossed by much smaller, closely arranged
concentric striz. Ears and beak unknown. Greatest breadth
parallel to the hinge a little below the middle, 3.39 inches;
height, or diameter from the base to the hinge, about 3 inches;
length of hinge, near 3 inches.

This fine species presents some anology, in size and general outline, to Awi-
culopecten concavus, of McCoy, (Synop. Carb. Foss. Ireland, tab. 15, fig. 10), but
may be readily distinguished by its more pointed posterior ear, and the coarser,
as well as more regular costa of its left valve, which is also a little convex,
instead of concave. In our figure, however, the costze are represented a little
too irregular, and too crowded on the posterior ear of the right valve. Usually
about eight or nine of the costze occupy a space of half an inch at the ventral
margin of the body of each valve. They seem always to increase by interca-
lation, the intermediate ones dying out between the free margin and the umbo. .

The specific name was given in honor of Prof. L. de Koninck, the distin-
guished palzeontologist of Liege.

Locality and position: Alpine, lowa; Lower Coal Measures.

AYVICULOPECTEN INTERLINEATUS, M. and W.

Pl. 26, figs. Ta, 7b.

Aviculopecten interlineatus, Manx and WortTHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 454.
SHELL (left valve) rather small, compressed, broad ovate or
subcircular exclusive of the ears, not oblique; length and
ay) Serr. 21, 1866.

330 PALZONTOLOGY OF ILLINOIS.

breadth nearly equal; hinge straight, about equaling the

greatest breadth of the valve below, ranging at right angles to
the vertical axis of the shell. Base regularly rounded; poste-
rior and anterior margins rounded from below the ears to the
base. Anterior ear triangular, flattened so as to be very dis-
tinct from the umbonal slope; posterior ear somewhat larger
than the other, compressed, triangular, the hinge side being
longer than either of the others, rather acutely angular at the
extremity. Beak compressed, a little nearer the anterior than
the posterior extremity of the hinge; umbonal slopes diverging
from the beak at an angle of about 78°; anterior one subangu-
lar. Surface ornamented by about fifteen regular, very promi-
nent, slender, and obscurely crenulated, concentric coste, which
are separated by spaces from four to six times their own
breadth, excepting on and near the ears; spaces between the
costz occupied by numerous fine, regular, closely arranged
concentric striz, which are crossed by faint indications of radi-
ating ribs. Diameter, from the pallial border to the hinge,
0.60 inch; breadth, from the anterior to the posterior margin,
0.62 inch; convexity, 0.12 inch. Right valve unknown.

This exceedingly beautiful species seems to have varied a little in the details
of its surface markings at different ages. In young shells, the regular concen-
tric costae seem to be nearly or quite smooth, but as the shell advanced in its
growth, they gradually assumed an irregularly crenulated outline, and become
themselves ornamented with extremely fine longitudinal strize, not visible with-
out the aid of a lens. These striz are very much finer and less distinct than
those occupying the spaces between the coste. The faint indications of radi-
ating cost, seen crossing the concentric striz in the depressions between the
concentric ribs, are also wanting on young shells.

We know of no other species, from either American or foreign localities,
nearly allied to this. It is probably the most elaborately ornamented species
of the genus known, and may present some corresponding differences in the
hinge and interior, that would warrant its separation as the type of a distinct
genus.

Locality and position: La Salle, Illinois; Upper Coal Measures, near horizon
of coal No. 11.

INVERTEBRATES. 331

AVICULOPECTEN OCCIDENTALIS, Shumard?
Pl. 27, figs. 4, 5, 5a.

Pecten occidentalis, SuuMARD, 1855. Missouri Geological Report, part ii, p. 207.
Pecten Cleavelandicus, SwauLow, 1858,

Aviculopecten —? Mrrx and Haypen, 1865.
p- 50, pl. ii, fig. 10.

Paleontology of the Upper Missouri,

Suit exclusive of the ears, broad subovate or flabelliform ;
length from beak to ventral margin, slightly greater than the

antero-posterior diameter; umbonal margins converging to the

beaks at an angle of 80° to 85°; lateral borders rounding into
the regularly rounded pallial margin; hinge line nearly or
quite equaling the greatest breadth of the valves. Left valve
distinctly more convex than the other ; ears subequal, the ante-
rior one being slightly shorter, more convex and more obtuse
than the other, as well as more distinctly defined by the um-
bonal angle—sinus separating each from the lateral margins ©
rather shallow, that on the posterior side being more broadly
rounded than the other; surface of each ear ornamented by
eight to ten or twelve unequal, small radiating costee, which
are crossed by numerous very fine, closely arranged concentric
strize ; body of the valve similarly marked, about twelve of the
larger costz reaching the beak, and the smaller intermediate
ones dying out at various distances between the beak and. the
pallial margin; one on the posterior umbonal slope larger and
more prominent than any of the others. Right valve nearly
flat and much more faintly ribbed than the other, with which
it agrees in form, excepting that the byssal sinus under the
anterior ear is much deeper and more sharply defined. Cardi-
nal area of moderate breadth, finely striated and inclined over
towards the left valve.* Diameter from beaks to ventral mar-

* In good casts of the area of this species, we have observed unmistakable evidences
of a very shallow, flattened, trigonal cartilage pit. It is unlike that of Pecten, how-
ever, being quite broad, distinctly triangular and very oblique, more as we see in

Trans. St. Louis Academy Sciences, i, p. 184.

a Gs ee
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302 PALEONTOLOGY OF ILLINOIS.

gin, 0.80 inch; antero-posterior diameter, 0.73 inch; convexity
of the two valves, 0.20 inch.

This is probably the species described by Dr. Shumard, in the Missouri Re-
port, from the Coal Measures of that State, under the name Pecten occidentalis,
and subsequently by Prof. Swallow from Kansas, under the name P. Cleave-
landicus. Apparently the same shell was found by Dr. Hayden, in a hard
siliceous rock near the Black Hills, Dakota. It likewise occurs in the Upper
Coal Measures of Kansas, where it ranges up into beds containing Permian
types.

The engraver was unsuccessful in representing the left valve of this species
by figure 5 of our plate. The outline, as there given, is correct, but the coste
are very imperfectly represented. On the shell they are a little flattened, and
separated by depressions wider than their own breadth, with usually a smaller
ene intercalated between each two of the larger, only the latter of which extend
up to the beak. Crossing all of these ribs and the depressions between, there
are numerous fine, closely arranged concentric striz, and a few stronger con-
eentric marks of growth, which latter often interrupt or dislocate the costz
towards the free borders. These characters are better seen in our figure 5a.
One of the ribs on the posterior umbonal slope of the left valve seems to be
always larger than any of the others.

Locality and position: Upper Coal Measures ; Saline Creek, Gallatin county,
Illinois.

Genus STREBLOPTERIA, McCoy.

Meleagrina (sp.), McCoy, 1844. Carb. Foss. Ireland, p. 80; (not Lam., 1819).
Pecten (sp.), McCoy, 1844. Ib., and others; (not Muller).
Streblopteria, McCoy, 1851. Ann. Mag. Nat. Hist., vii, p. 170, (without type or exam-
ple); 1855, Brit. Paleozoic Foss., third part, p. 482.
“SHELL ovate or rounded, obliquely extended towards the
anterior side; posterior wing broad, undefined, nearly rectan-

gular, extended nearly as far as the .posterior margin of the

Meleagrina. It is traversed by the same fine striz that mark other parts of the area.
One of the most important distinctions between this genus, as generally understood,
and all of the modern type of the Pectinide, is the presence of a distinct, well-defined
cartilage pit in the hinge of the latter. The species under consideration, however,
shows that there was, sometimes at least, a slight tendency to form a similar cartilage
depression in the area of Aviculopecten, thus furnishing another evidence of the imper-
ceptible gradations by which all groups will probably be found linked together when we
can have an opportunity to compare very large numbers of the living and extinct types.

*

— oe 2 es

a

INVERTEBRATES. 333

shell; anterior ear small, deeply defined; surface smooth or
radiately ridged; one large, faintly marked, muscular impres-
sion a little behind the middle; one short, narrow tooth slightly
-diverging from the hinge on the posterior side of the beaks;
ligament confined to a narrow, simple facet on the hinge
margin.”

In first publishing the above description in 1851, Prof. McCoy neither fig-
ured, described, nor cited any known shell as a type or example of his proposed
genus; and it was not until he republished it in 1855, and described under it
his S. levigata and S. pulchella (previously placed by him in the genus Melea-
grina), that Paleontologists had the means of knowing definitely what group
he had proposed the name for. Hence, we can scarcely regard the genus as
having been established, until the date of the latter publication.

The two species just mentioned, were alone placed by Prof. McCoy in this
genus, and as the last mentioned one, his S. pulchella, seems to be only known
from a niere fragment, giving no very satisfactory idea of either its generic or
specific characters, his first species, 9. levigata, must of course be regarded as
the type of the genus. This is a thin, compressed, smooth, Pectenoid shell,
with rather short, nearly rectangular ears, a short hinge line, anda very promi-
nently rounded, antero-ventral outline. The latter character, together with
the short hinge line, and position of the beaks a little behind the middle of the
hinge line, give the valves a rather curious backward obliquity, regarded by
Prof. McCoy as a generic character. Uis figure shows a moderate sinuosity of
the anterior margin, under the anterior ear, but as it was drawn from a left
valve, and he describes the anterior ear as being “deeply defined,” we think
the genus may probably be found to include a somewhat wider range of forms
than its author seems to have intended. Hence we would place here several
species that have been referred by Prof. McCoy, and others, to the genus Pecten,
and have not, at least so strongly marked, the peculiar backward obliquity of
the typical species of Streblopteria. The shells we allude to are smooth, little
Carboniferous and Permian species, and seem to have generally, if not always,
a deep, sharply defined byssal sinus in the anterior margin of the right valve.
It is possible these species may not possess the hinge characters of the type of
this genus, but as they certainly do not belong to the genus Pecten, as prop-
erly restricted to such forms as P. maximus, and appear to agree more nearly
in general physiognomy with Streblopteria, than with Aviculopecten, or any of
the other eslablished genera, it seems proper to so dispose of them until their
affinities can be more clearly determined from specimens showing the hinge and
interior. In addition to the following described species, we would thus refer
to this genus such forms as Pecten dissimilis and P. consimilis, McCoy, and P.

334 PALZONTOLOGY OF ILLINOIS.

pusillus, Munster, as well as some of the forms generally referred to Aviculo-
pecten. They probably all differ from the latter genus, not only in their trun-
cated, or smaller posterior ear, and greater thinness, but in having no cardinal
area, or at least only a merely linear one. Like the typical species of the
latter genus, they are doubtless not provided with the cartilage pit, so charac-
teristic of the more modern types of the Pectinide.

Prof. Winchell, has proposed the name Pernopecten* (Proceed. Acad. Nat.
Sci. Philad., July, 1865, p. 125), for a somewhat similar type. That genus,
however, differs in having a central cartilage pit under the beaks, with smaller
pits along the hinge on each side, while it wants the deep byssal sinus under
the anterior ear of the right valve, seen in Streblopteria.

STREBLOPTERIA ? TENUILINEATA, M. and W.

Pl. 26, fig. 9a, 9b.
Pecten tenuilineatus, Mrnk and WortHeEn, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 452.
Compare P. pusillus, Schlot., 1816. Akad. Munch., vol. vi, p. 31, pl. vi, fig. 6a, 66, 6c.

SHELL small, compressed, thin, very nearly equivalve, broadly
subovate in outline, with a slight backward obliquity; ventral
margin regularly rounded; posterior margin forming a broad
gentle curve along the middle and below, and intersecting the
hinge above at an angle of about 120°; anterior margin promi-
nent, rounding regularly from the termination of the produced
anterior umbonal slope into the base; hinge line very short, or
only about equaling half the antero-posterior diameter of the
valves, ranging nearly at right angles to the longer axis of the
shell. Posterior ear of both valves nearly obsolete, obliquely
truncated, and compressed, but not very distinct from the com-
pressed posterior umbonal slope, nor defined by any marginal

* The type of Pernopecten, is P. cooperensis—(Avicula cooperensis, Shumard,—Avic-
ulopecten limaformis, White and Whitfield). The typical specimen of this species fig-
ured by Dr. Shumard in the Missouri Report, shows a few obscure, radiating coste—
an exceedingly rare character, though we have occasionally seen faint indications of
them on other specimens. Hence Dr. Shumard’s species has not been generally iden-
tified, and Prof. Hall, in the lowa Report, p. 522, pl. 7, fig: 9, erroneously refers appa-
rently the same shell to Avicula circulus, of Shumard, a quite different species.

INVERTEBRATES. 335

sinuosity. Anterior ear rather larger than the other, but not
equaling the prominence of the margin below; in the right
valve rounded at the extremity, and defined by a deep, sharply
cut byssal sinus, from the extremity of which a small sulcus
extends obliquely upwards to the anterior side of the beak; in
the right valve flattened, broader, and truncated so as to meet
the hinge line at an obtuse angle, with but a very slight mar-
ginal sinuosity, rather distinct from the oblique anterior umbo-
nal slope. Beaks small, rather compressed, nearly or quite
equal, and terminating a little behind the middle of the cardi-
nal margin; anterior umbonal slopes oblique, and more distinct
in both valves from the ear, as well as more produced, than
the posterior. Surface, to the unassisted eye, apparently
smooth, but when examined with a magnifier, seen to be
marked with very fine, regular, closely arranged concentric
striz, which, on the anterior ear of the right valve, become
suddenly much coarser and more strongly defined. In some
instances, the faintest possible traces of something like radia-
ting ribs may be seen on the right valve, in a cross light, under
the magnifier. This latter character, however, is rarely visi-
ble, and would scarcely ever be observed unless carefully looked
for. Diameter, from hinge to pallial margin, 0.57 inch; antero-
posterior diameter, 0.53 inch; convexity, 0.10°inch; length of
hinge line, 0.27 inch.

This little shell is evidently closely allied to Pecten pusillus, Schlutheim, from
the European Permian rocks. Compared ‘with Prof. King’s figures of that
species (Permian Fossils of England, pl. xiii, figs. 1, 2, 3 and 4), it differs in
having no radiating costee visible to the unassisted eye, while its anterior out-
line does not, in the right valve, round so regularly into the byssal notch above.
Prof. King’s figures of the left valve, which he says are too oblique, differ from
that of our shell in having the obliquity in the opposite direction. On com-.
paring Prof. McCoy’s description of P. pusillus (Brit. Pal. Foss., p. 477) with
our shell, we have been struck with its almost exact agreement, and led to sus-
pect that they may prove identical.

Dr. Geinitz has also figured, in his beautiful work on the Permian Fossils of
Germany (Dyas, pl. xv and xix), under the names Pecten pusillus and P. sert-

"

mm «

r

ae ee

336 _ PALAONTOLOGY OF ILLINOIS.

ceus, forms so nearly resembling our shell as to strengthen the suspicion that
they may all belong to one species. His fig. 1 ab, pl. xv, representing a right
and left valve of P. pusillus, agree very nearly with those before us, excepting
that his fig. 1 @ represents the left valve as having distinct radiating markings
on the anterior ear; while his figures of both valves show the beaks a little
more prominent. His figures 2ab and 3a, representing right valves of
larger individuals, figured under the name P. sericeus—=( Avicula sericea, de Ver-
neuil), which he regards as identical with P. pusillus (sp.), Schlot.,* agree well
with the corresponding valve of our shell, except in having the anterior ear
narrower, and the sinus under it wider. On plate xix, fig. 23, he gives a figure
of a left valve, under the name P. sericeus, that shows, though in a less marked
degree than some of our specimens, the peculiar backward obliquity that leads
us to think these forms may belong to Streblopteria.

In making comparisons with our figure 9a, the reader should be informed
that the engraver has shaded the posterior ear so as to look too abruptly flat-
tened and distinct from the umbonal'region, while the concentric striz should
only be barely indicated, and closely crowded, instead of rather distinctly visi-
ble and distant. Some of the specimens have the anterior margin much
more prominently rounded than that we have figured, so as to give a greater
backward obliquity to the whole outline. This is particularly the case with
left valves, in which the anterior oblique umbonal slope is quite distinct from
the flattened anterior ear.

Locality and position: South line of Clinton county, Illinois; Upper Coal
Measures, near No. 11 coal; associated with Monopteria longispina, ( Gervillia
Cox), Myalina Swallovi, McChesney, and a large Myalina, agreeing with a
form figured by Meek and Hayden, in their Upper Missouri Paleontology, p.
33, as M. subquadrata, Shumard, var. ampla.

Genus EUMICROTIS, Meek. *

Synon.—Avicula (sp.), Auct., (not Klein.)
Monotis, Kine, 1849; Meek & Hayden, 1858; Shumard, 1859; (not Bronn, 1830).
Aucella, McCoy, 1852. Brit. Paleozoic Foss., p. 481; (not Keyserling, 1842).
Eumicrotis, Mex, March, 1864, Am. Jour. Sci., xxxvii, p. 216; Paleontology
Upper Missouri, 1865, p. 53.

_ SHELL suborbicular, plano-convex, the left valve being usually
very convex and the right flat, or even a little concave; not

* We should have little hesitation in referring the shells figured by Dr. Geinitz, to
P. pusillus, but judging from de Verneuil’s single figure of his Avicula sericea, we
should, like that gentleman, haye regarded it as an entirely distinct species.

4 J —
~ A : ‘ a) _
\ —Gomeg Pn if ar r 7 . OU fare ao oy eC a
¢c MWe CHE be ee oe a - - =
a

ere

INVERTEBRATES. 337

distinct auriculate, the ears being nearly obsolete. Beaks cen-
tral, very slightly oblique, unequal, that of the left valve often
elevated, gibbous, and incurved; the other very small, and
scarcely extending beyond the hinge line. Hinge short, nar-
row, edentulous; cartilage pit under the beaks in a somewhat
flattened area. Byssal notch or sinus of right valve narrow,
deep, and separated from the hinge by a very small rudimen-
tary ear, which does not project beyond the margin. Adductor
muscular scar large and subcentral; impressions of retractor
muscles, small, and placed near the beaks. Surface generally
ornamented with radiating, more or less vaulted or scaly coste,
much more distinctly marked on the left than the right valve.

This genus has been frequently referred to Monotis of Bronn, an entirely
distinct Jurassic or Triassic genus, from which it was separated by one of the
writers in 1864. It differs completely, in form and general physiognomy, from
the type of Bronn’s genus (Monotis Salinaria), in being very inequivalvye or
planoconvex, not at all or very slightly oblique, and particularly in being
always provided with a very deep, sharply defined byssal sinus under the beak
of the right valve.* It is more nearly allied, as stated by the author, in pro-
posing the genus, to Keyserling’s genus Aucella, to which Prof. McCoy referred
one of the typical species in 1852; but it differs from that Jurassic group in
being much less oblique, more inequivalve, and provided with radiating coste,
as well as in possessing a distinct cartilage pit under the beak. The latter
character has led Prof. King to suppose it more nearly allied to the Pectinidx;
but as was shown by the author, in founding the genus, its shell presents, under
the microscope, the prismatic structure of the Pteriidx (= Aviculidx), and not
the structure characterizing the Pectinidz.

In Europe this group is generally regarded as not dating back farther than
to the Permian period, but in this country we find species of it in rocks that
cannot be separated in any way from our Coal Measures.

* The absence of any traces of a byssal sinus in the type of the genus Monotis, would
seem to indicate a difference in the habits of the species of that group, from those of
Humicrotis, which, judging from their strongly defined byssal notch, were during life
habitually attached by a byssus.

eA Supr, 24, 1866,

338 PALEONTOLOGY OF ILLINOIS.

Evwicrotis Hawni var. stnuata, M. and W.
Pl. 27, figs. 12, 12a, 128, 13 and 14,

Monotis Hawni, Mrex and Haypmn. Trans. Albany Inst., iv, March 2, 1858.
Eumicrotis Hawni, Menx. Am. Jour. Sci., xxxvi, March, 1864, p. 216; Meek and Hay-

den, Paleont. Upper Missouri, 1865, p. 54.

SHELL oval-suborbicular, plano-convex, not oblique; ventral
margin rounded in outline; posterior side obliquely truncated
above; anterior side somewhat obliquely straightened above,
or rounding regularly from below the ear to the base ; cardinal
margin shorter than the greatest transverse diameter of the
valves; hinge area moderately broad, and distinctly inclined
over towards the left valve; cartilage pit distinct, rather broad,
and placed directly under the beaks, being common to both
valves. Left valve ventricose, umbo not oblique, incurved and
projecting a little above the cardinal margin; posterior ear
little developed and obliquely truncated; anterior ear slightly
longer, rounded at the extremity, and separated from the ante-
rior margin by a deep, well defined, angular sinus; surface
ornamented with more or less waved or distorted radiating
costz, of unequal size, there being generally one, two or three
smaller ones between each two of the larger—all crossed by
concentric, imbricating lamillee of growth, which on the larger
ribs rise in the form of vaulted subspiniferous scales. Right
valve flat, or very nearly so; beak obsolete ; byssal sinus very
narrow and deep; muscular impression subovate, oblique and
placed a little behind the middle; surface much more obscurely
costate than that of the left valve. Diameter from hinge to
basal margin, 1.25 inch; antero-posterior diameter, 1.12 inches ;
convexity, about 0.35 inch.

Although we have placed this as a variety of /. Hawni, we are much inclined
to believe it will prove to be a distinct species, since it differs from all the
Kansas specimens of that shell we have seen, in having a rather distinct sinus .
in the anterior margin of the left valve, as well as in the truncated outline of

INVERTEBRATES. 339

its posterior margin. In its surface markings it seems to agree exactly with that
species, as well as with the European LH. speluncaria. From the latter, however,
it differs much more widely in form than from £. Hawni; while the muscular
impression of its right valve is much narrower than that of L. speluncaria, as
figured by Prof. King.

The specimens of this form under examination, show very distinctly the
cast of the cartilage pit, which is deepest in the left valve, the beak of which
curves directly over it. (See cast of this pit represented by a pronfhence
under the beak in fig. 13.) It differs from the cartilage pit in Avicula, in not
being in the slightest degree oblique. One of the writers, in proposing this
genus, upon some Kansas specimens, was unable to verify Prof. King’s descrip-
tion of the nature of the cartilage pit, but the specimens now before us confirm
Prof. King’s statement exactly, and there can be little doubt that the presence
of this pit is a constant character in this genus.

Locality and position: Bridge of north branch Saline river, Gallatin county,
Illinois; Upper Coal Measures.

Genus PTERINEA, Goldfuss, 1833.
(Petref. Germ., ii, p. 133.)
Suscenus MONOPTERIA, M. and W., 1866.
(vovos, solitary; zzepoy, a wing—in allusion to its single wing.)

Synon.— Gervillia, Cox, 1857. Kentucky Geol. Rep., vol. 3,p. 568; (not Defrance, 1820.)
Monopteria, Maxx and WortTuHEN, 1866. Proceed. Chicago Acad. Nat. Sci.,
vol. i, p. 20. >»

SHELL aviculoid, obliquely produced and angular posteriorly,
and rounded in front; subequivalve, both valves being’convex.
Posterior wing slender and produced, anterior one obsolete or
merely represented by a very small ear-like appendage drawn
back between the beaks in a deep lunule, so as not to be seen
in a side view, exactly as in the Silurian type Amphiceelia,
Hall.* Anterior margins without a byssal emargination in
either valve, but apparently a little gaping in the lunule, just

* Amphicelia, Hall, was proposed as a subgenus under Leptodomus, to which it is
not nearly allied. It evidently belongs to the Aviculide, near Pterinea, though appa-
rently generically distinct.

340 PALMONTOLOGY OF ILLINOIS.
under the small rudimentary ear. Muscular impressions very
faintly marked. Cardinal area rather narrow, and provided
with but few longitudinal cartilage furrows. Hinge edentulous.

This type differs from the typical species of Pterinea, not only in form and
general physiognomy, but in its edentulous hinge, and very obscurely marked
or obsolete, anterior muscular impression. It will be readily distinguished
from Gervillia, to which the typical species was referred by Prof. Cox, in the
Kentucky Geological Report, by being entirely without any traces of the trans-
verse cartilage pits characterizing that genus, and indeed of the entire sub-
family to which it belongs.

Whether or not this group should be made to include such forms ag Gervillia
lunulata and G. laminosa, Phillips (Geol. Yorksh., ii, pl. vi.), which have a
well developed, distinctly projecting, lobe-like anterior ear, we have no means
of determining, until those forms have been more fully characterized. That
they are true Gervillias, however, is exceedingly improbable.

PrERINEA (MONOPTERIA) GIBBOSA, M. and W.
Pl. 27, figs. 11, 11a, 110:

Pterinea (Monopteria) gibbosa, Mzrx and WorTHEN, June, 1866. Proceed. Chicago
Acad. Sci., p. 20.

SHELL irregularly suborbicular, moderately gibbous ; anterior
outline from a little below the middle, forming with the base
a more or less regular semicircular curve, and sometimes
obliquely truncated, with slightly concave outline in the region
of the lunule from the beaks above. Posterier basal margin a
little sinuous; posterior extremity attenuate and angular;
umbonal ridge rather prominent from near the back part of the
beak to the produced posterior extremity of each valve ; beaks
equal, scarcely projecting above the cardinal margin, and as it
were, drawn some distance back of the prominently rounded
front. Anterior margins just in front of and under the beaks,
abruptly inflected to form the deep lunule; anterior ear
minute, rounded and placed very close up under or between the
' beaks. Hinge line straight, less than the entire length of the

INVERTEBRATES. 341

shell, owing to the prominence of the front below the beaks.
Cardinal area with three or four linear, longitudinal cartilage
furrows, one of which seems to have been deeper and wider
than the others near the beaks. Posterior wing slender, rather
compressed, and extending at least as far back as the extrem-
ity of the valves below, from which it is separated by a very
profound, rounded sinus. Surface only marked by fine con-
centric strive of growth. Length, about 1.05 inches; height
0.86 inch ; convexity, 0.52 inch.

This species is related to P. (Monopteria) longispina (= Gervillia longispina,
Cox, Kentucky Geological Report, vol. 3, pl. viii, fig, 6), but differs in being
much less oblique, in having its anterior margin much more prominently
rounded beyond its beaks, which are set farther back, as well as in having the
posterior extremity of its valves much less produced. Judging from Prof. Cox’s
figure, his species would seem to also have stronger marks of growth than our
shell, but we have seen specimens of a form from the Coal Measures of Clinton
county, of this State, agreeing well with Prof. Cox’s figure in other respects,
that presented an almost entirely smooth surface.

Gervillia auricula, Stevens (Am. Jour. Scz., vol. xxv, March, 1858, p. 265),
evidently belongs to this group, and seems to us to be identical with that de-
scribed by Prof. Cox, under the name G‘. longispina.

Locality and position: Saline creek, Gallatin county, Illinois; from a ferru-
ginous sandy seam in shale, apparently, judging from the affinities of its fossils,
holding a position near or above the horizon of the eleventh bed of coal, in the
Kentucky section of the Coal Measures.

Genus MYALINA, deKoninck, 1844.

(Ann. Foss. Belg., p. 125,)

MyAuinaA SwAtiovi, McChesney.
Pl. 27, fig. 1, la, 16, le, 1d.

Myalina Swallovi, McCuzsney, 1860. New species Paleozoic Fossils, p.57; also, pl. 2,
fig. 6a, 60, Illustrations of same, 1865.

SHELL small, oblique, very nearly equivalve, gibbous along
the umbonal slopes, and presenting almost exactly the outline

342 PALEONTOLOGY OF ILLINOIS.

of a Modiola. Anterior margin sinuous, but not gaping in the
middle, and forming a kind of lobe above in front of the beaks
and umbonal ridges; beaks compressed, small, very oblique,
not quite terminal, depressed; umbonal ridge prominent, ex-
tending from the beaks obliquely backwards and downwards
in advance of the middle of the valves, gradually dying out at
the anterior ventral margin; hinge line equaling at least half
the entire length of the valves, straight, but passing into the
posterior margin without forming a perceptible angle ; posterior
side compressed, cuneate, and forming in outline a graceful
descending curve to the narrowly rounded - posterior basal ex-
tremity. Cardinal area very narrow, with not more than two
or three linear cartilage furrows. Surface marked with fine
obscure concentric strize, and a few not very apparent stronger
marks of growth. Length, 1.08 inch—measuring obliquely
from the umbonal extremity to the posterior basal margin ;
breadth at right angles to the longer axis, 0.51 inch; convexity
of the two valves, 0.37 inch.

This species differs from M. recta, Shumard,* and I. perattenuata, Meek and
Hayden,} in having its beaks not quite terminal, and its anterior margin above
the middle, projecting in front of the beaks and umbonal ridge as a kind of lobe.
Its beaks are also much less attenuate and pointed. It also differs from JL recta
in not having its umbonal ridge “angulated” nor its interior margins inflected
at an acute angle with the plane of the body of the shell, while none of the
specimens show any traces of the fine radiating striz sometimes seen on that
species. From Myalina squamosa (= Mytilus squamosus, Sowerby), some varie-
ties of which (supposing that shell to vary to the extent represented by Prof.
King) it resembles, it will be readily distinguished by its much narrower cardi-
nal area. It is also a much less variable species.

Locality and position: Same as last.

'* St. Louis Academy of Sciences, i, p. 212. + Trans. Albany Inst., iv, March, 1858.
{ This lobe is partly hidden by the matrix, in the specimen figured by Prof. McChesney.

INVERTEBRATES. 343

MYALINA MELINIFORMIS, M. and W.

Pl. 27, fig. 3.

Myalina meliniformis, Mezx and WortTuHeEn, March, 1866. Proceed. Chicago Academy

Sci., vol. i, p. 19.

SHELL rather small, mytiloid, very nearly equivalve, not
very oblique; posterior margin rounding down with a broad
regular curve from the extremity of the hinge; base rather
recularly rounded; anterior margin descending at rather less
than a right angle with the hinge, with a concave outline,
in both valves inflected so as to meet at a very obtuse angle ;
hinge rather short, arched, and ranging at an angle of about
60° with the longer axis of the valves; beaks terminal and
directed forward, not projecting above the hinge; umbonal
slopes rounded, and curving down from the beaks near the ,
anterior side—scarcely as convex as the sides of the valves
just behind them. Cardinal area narrow and finely striated.
Muscular impressions distinct, subcircular, and placed a little
below and behind the middle of the valves; pallial scar well
defined, and extending from the lower anterior side of each
adductor impression a little forward, and then curving and
ascending near the anterior side of each valve, as a row of dots,
towards the beaks—posteriorly it ascends from the upper pos-
terior side of the adductor scar, in the same way. Surface
unknown. Length, from the beaks obliquely to the posterior
basal margin, 1.05 inch; breadth (antero-posterior diameter),
0.52 inch; convexity, 0.35 inch.

We only know this species from internal casts, from which, however, it is
seen to differ materially from the last, in being very much less oblique, and in
having no lobe-like projection, in front of the beaks. It is much more nearly
allied to M. permiana of Swallow, from which it differs in having its umbonal
slopes much less prominent, and ‘more rounded, while the sides of its valves,

just behind and above these umbonal slopes, are more convex. In form, it is
~ almost an exact miniature of a large ponderous shell figured on page 33 of

344 PALEONTOLOGY OF ILLINOIS.

.Meek and Hayden’s Paleont. Upper Missouri, as M. subquadrata, of Shumard.
In addition to its greatly smaller size, however, it differs in having its valves
more convex in the postero-dorsal region, and its hinge more arched.

Locality and position: Same as last. °

MYALINA RECURVIROSTRIS, M. and W.

Pl. 26, figs. 9a, 96, 9c.

Myalina recurvirosiris, MpEK and WorTHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 456.

SHELL of medium size, moderately thick, obliquely subtrigo-
nal, distinctly inequivalve (the left valve being more convex
and thicker than the other); very gibbous and narrowly
rounded along the umbonal slopes. Hinge nearly or quite
straight, about equaling in length the height of the shell in
young specimens, but proportionally shorter in adult exam-
ples. Posterior side compressed; its margin a little convex
in outline, ranging nearly at right angles to the hinge above,
and rounding gradually into the narrowly rounded base below;
anterior side a little concave in outline, and ranging at an
angle of about 55° with the hinge. Beaks small, teminal,
pointed, that of the left valve being twisted so as to make
nearly one entire turn at the extreme point, which is directed
obliquely forward; beak of right valve less prominent, nearly
straight, and directed forward. Surface of left valve marked
by distinct lines, and imbricating laminz of growth, which are
quite prominent on the anterior side and near the cardinal
margin behind; right valve more obscurely marked. Liga-
ment area comparatively narrow, and marked by a few distinct
longitudinal furrows. Anterior margin immediately under the
beaks thickened, so as to present a broader area than the hinge,
from which it is separated, in the left valve, by an oblique
groove, and in the other by a corresponding prominence. Pos- |
terior muscular impression large, elongated or narrow-subovate,

/

INVERTEBRATES, ~ 845

pointed above and rounded below, located near the middle of-
the posterior side, and curved parallel to the margin of the
valves. Height, measuring at right angles to the hinge, 1.73
inches; breadth, at right angles to height, about 1.66 inches;
convexity, 0.95 inch; greatest length, parallel to the umbonal
ridges, 2.12 inches.

In size and general outline this shell resembles somewhat a species described
from Kansas, by Dr. Hayden and one of the writers, under the name of Mya-
lina aviculoides, (Proceed. Acad. Nat. Sct., Philad., May, 1860, p. 184*). Jt
differs, however, materially in the spirally curved character of the beak of its
left valve, and the less sinuate outline of its anterior side. It also differs in
having much stronger imbricating marks of growth, particularly on the left
valve. The Kansas species is likewise more nearly equivalve, and has its ante-
rior side more prominent, or somewhat lobed just under the beaks.

Norz.—Since the above was written, farther comparisons lead us to suspect
that this species is identical with WM. kansasensis, Shumard, (TZrans. St. Lowis
Academy Sci., i, p. 213), though none of our specimens show any traces of the
erenate lamallz mentioned in the description of that species.

Locality and position: La Salle, Illinois; about the horizon of No. 11 Coal,
of Upper Coal Measures.

Genus SCHIZODUS, King, 1844.

(Ann. Mag. Nat. Hist., xiv, p. 313.)

Scuizopus (sp?).

Pl. 27, fig. 7.

We only know this shell from imperfect casts, that give a rather unsatisfac-
tory idea of its specific characters. Since our figure was engraved, however,
we have found a better specimen, by breaking some masses of the matrix, than
that from which our drawing was made. From this it would seem that the one
represented by our drawing has lost portions of its anterior ventral margin, and
that our outline restoration of the broken posterior margin is not exactly cor-
rect. Hence it is probable that our figure is turned so as to represent the beaks
and umbonal slopes as being too oblique, and the former too near the anterior

* See also Paleontology of Upper Missouri, part 1, pl. ii, fig. 8a, 8b, 8c, 8d.

ay Ser. 94, 1866,

346 PALEONTOLOGY OF ILLINOIS.

. extremity. Since seeing the better specimen alluded to above, we are much
inclined to believe this to be the species figured and described by Prof. Hall,
under the name Dolabra? alpina, in the Iowa Report (p. 716, pl. 29, fig. 2).
It is clearly not a Dolabra, however, but a true Schizodus, as was (in conan to
the Iowa specimen) first pointed out by Meek and Hayden, in a note on page
58 Paleontology of the Upper Missouri. —

Both of the casts before us show a rather distinct sulcus, passing obliquely
backwards and downwards from the posterior side of each beak along the um-
- bonal slopes. This sulcus was of course occupied by a corresponding ridge on
the inside of each valve. Somewhat similar marks are represented on casts of
Schizodus obscurus, figured by Geinitz (Dyas, pl. xiii), though our fossil is very
unlike that shell in other respects, and apparently more nearly allied to S.
truncatus of King, but still distinct from that also.

Locality and position: North Branch of Saline creek, Gallatin county, EROS 5
Uprer Coal Measures. .

Genus EDMONDIA, de Koninck, 1844.
(Anim. Foss. Carb. Belg., 66.)

EDMONDIA UNIONIFORMIS, (sp.) Phillips?

Pl. 27, fig. 6, 6a, and 66.

Isocardia unioniformis, Puinuips, 1836. Geol. Yorks., ii, p. 209, pl. 5, fig. 18.
Edmondia unioniformis, Dr Kontwex, 1844. Anim. Foss. Belg., p. 67, pl. 1, figs. 44,40, 4c.

Suet gibbous, oval-suborbicular, the length being a little
greater than the height; greatest convexity near the middle of
the valves; basal margin forming a semi-elliptic or semi-oval
curve; anterior margin rather more narrowly rounded than the
posterior, which latter is sometimes faintly truncated; cardinal
margin rather short, straight, and horizontal behind the beaks.
Beaks gibbous, rather prominent, incurved, and placed a little
nearer the anterior than thé posterior side.. Surface marked
with small, irregular, concentric ridges and fine stris, which
are apparently sometimes crossed by very obscure traces of
radiating lines on the posterior dorsal region. Length, 1.06
inch; height, 0.90 inch; convexity, 0.70 inch.

INVERTEBRATES. 347

It is with considerable hesitation that we refer this species, even with a,
query, to Phillips’s wnioniformis. It certainly looks so unlike his figure that
we should scarcely have thought even a comparison necessary, had it not been
that Prof. de Koninck very positively identifies with Phillips’s species, after a
direct comparison with authentic English specimens, a form differing but
slightly from our shell. Prof. de Koninck’s figures represent a form rather more
gibbous, and more rounded in outline behind, than that figured by us, but some
of our specimens, not figured, agree more nearly with his in these characters.
Unless the #. unioniformis is a very variable shell, we should think it entirely
distinct from ours, as well as from that figured by Prof. de Koninck.

Dr. Geinitz refers a shell to Panopexa, from the Permian rocks of Germany,
somewhat like ours, but agreeing much more nearly with Prof. de Koninck’s
figures. (See P. lunulata, G.—Dyas, p. 58, pl. xii, fig. 22.) We cannot be-
lieve, however, that such a form can be properly referred to Panopzxa, nor can
we agree with those who refer to that genus any palzeozoic species.

Prof. Swallow has described, in the Transactions of the St. Lowis Academy
of Sciences, several species from Kansas, under the names Mdmondia and Car-
diomorpha?, some one of which may be identical with our shell, but as he has
only published rather brief descriptions, without figures, we have not the means
of satisfactorily determining this point.

Our figure is from an internal cast, and shows the i impression Gen 6 and 6 a)
of the internal cartilage plate.

Locality and position: North branch of Saline creek, Gallatin county, Illi-
nois; Upper Coal Measures.

Genus PLEUROPHORUS, King, 1844.

(Ann. Mag. Nat. Hist., xiv, p. 313.)

PLEUROPHORUS suBCosTATUS, M. and W.

Pl. 27, fig. 2 and 2a.
Pleurophorus subcostatus, Mzrx and WortuHen, Dec., 1865. Proceed. Acad. Nat. Sci.,

Philad., p. 246.

Suet elongate-oblong, moderately convex; umbonal ridges
the most convex part of the valves, and extending obliquely
from the beaks towards the postero-basal margin; anterior
ventral region somewhat compressed ; basal and cardinal mar-
gins very nearly straight and subparallel, the former being

348 PALAONTOLOGY OF ILLINOIS.

usually somewhat sinuous or arcuate along the middle; extremi-
ties rather narrowly rounded, the posterior being generally a
little wider than the other, and sometimes faintly subtruncate
obliquely. Hinge line long and nearly straight; posterior
lateral tooth of each valve elongated parallel to the hinge mar-
gin, very remote from the cardinal teeth, and extending back
a little beyond the posterior muscular impression. Beaks de-
pressed upon a line with the dorsal margin, small, somewhat
compressed, and placed about one-ninth the entire length of
the shell behind the anterior margin. Scar of the anterior
adductor muscle deep, trigonal-subovate, pointed above, and
strongly defined by the prominent vertical ridge just behind it;
those of the pedal muscles small, nearly marginal, and located
directly over the anterior adductors; posterior adductor scars
larger and more shallow than the anterior, subquadrate in out-
line, and placed close up under the posterior hinge teeth. Pal-
lial impression well defined. Surface of casts showing traces
of a few obscure concentric markings, crossed on the postero-
dorsal region by traces of about three equal obscure radiating
cost. Exterior surface and cardinal teeth unknown. Length
of a medium sized specimen (internal cast), 0.88 inch; height
of do., 0.37 inch; convexity, 0.26 inch. Some larger speci-
mens, of same proportions, measure 1.33 inches in length.

This species is apparently related to P. costatus, of Brown (sp.), some vari-
eties of which, as figured by Prof. King (Monogr. Permian Fossils, England,
pl. xv), it closely resembles, at any rate so far as can be determined from the
comparison of internal casts. Yet it evidently differs from that species, in
having the sears of its pedal muscles nearly marginal, and placed directly over
those of the anterior adductors, instead of partly behind them upon the inter-
nal ridge. This ridge is also stronger in our species, while the basal margins
of its valves are likewise more sinuous.

This shell is also scarcely distinguishable from a form that has been regarded
as a variety of P. subcuneatus, Meek and Hayden, in the Permian and Permo-
carboniferous beds of Kansas. Whether specifically identical with this Kansas
shell (the supposed variety of P. subcuneatus), may admit of some doubt; but
it certainly differs materially from the typical form of P. subcwneatus, not only

INVERTEBRATES. 349

&
iz attaining a much larger size, but in its distinctly sinuous instead of convex
basal margin; also in the presence of radiating postero-dorsal costze.

Locality and position: North branch Saline Creek, Gallatin county, Illinois,
in a bed belonging to the Upper Coal Measures.

Genus SOLENOMYA, Lamarck, 1819.

(Solemya, Lamarck, An. Sans. Vert., vol. v.)

SoLENOMYA RADIATA, M. and W.

Pl. 26, fig. 10a, 108.

Solemya radiata, Murx and WorTHEN, October, 1860. Proceedings Acad. Nat. Sci.,
_ Philad., p. 457.

SHELL thin, narrow oblong-oval or elongate subelliptical,
moderately convex, nearly closed at each end; pallial margin
rather straight or very slightly contracted along the middle,
and rounding up more gradually in front than behind; anterior
(longer) side narrowly rounded, its most prominent part being
above the middle; posterior (shorter) side narrowly rounded
below and obliquely subtruncate above; dorsal outline nearly
parallel to the base; beaks much depressed, located less than
one-fourth the entire length of the shell in advance of the
posterior extremity. Surface with obscure marks of growth,
crossed by flat, nearly obsolete, radiating plications, which are
sometimes separated, near the middle of the valves, by spaces
greater than their own breadth; plications very oblique and
more closely arranged on the anterior side. Length, 1.17
inches ; height, 0.47 inch; convexity, about 0.33 inch.

Some specimens show the radiating plications nearly as distinctly on the
internal cast as on the exterior of the shell. These casts retain distinct impres-
sions of an oblique ridge just in advance of the posterior muscular impression,
but both the muscular scars seem to be very faintly marked. It is possible our
specimens may have been partly closed by pressure in the matrix, though they
have the appearance of having been but slightly gaping at either end—more
particularly behind.

350 PALEONTOLOGY OF ILLINOIS.

From the same locality and position we have a few specimens of a nearly
allied form, that may possibly belong to the same species as this, though we
think they are distinct. These are considerably larger and less depressed,
with scarcely any traces of radiating markings, but have more distinct concen-
tric wrinkles. They also differ in being more broadly rounded in front.

The species under consideration (S. radiata) seems to be related to S. pri-
meva of Phillips (Geol. Yorksh., vol. ii, tab. 5, fig. 6), but differs in being less
depressed, more narrowly round in front, and entirely destitute of any traces of
fine radiating strize between the obscure costz.

Locality and position: Schuyler county, Illinois; Coal Measures.

Genus ALLORISMA, King, 1844.

(Ann. Mag. Nat. Hist., xiv, p. 315.)

ALLORISMA (sp. undt).
Pl. 27, fig. 9, 9a.

THE only specimen of this species we have seen is a mere cast, not entirely
perfect at either extremity, so that we have not the means of determining sat-
isfactorily whether it is new or not. As near as can be determined, it seems
to be proportionally shorter and more gibbous than any otherwise similar spe-
cies with which we are acquainted. Ina side view it is not unlike a species
from the middle Coal Measures at Lexington, Missouri, described by Prof.
Swallow, under the name A. /ata. On comparison, however, with the typical
specimen of that species, it was found to be much more gibbous, and marked
with proportionally larger concentric ridges. Compared with A. subcuneata,
Meek and Hayden, from the Coal Measures of Kansas (Paleontology Upper
Missouri, pl. i, fig. 10a, 106), it will be seen to be proportionally much shorter,
and more broadly rounded posteriorly.

Locality and position: North Branch Saline creek, Gallatin county, Illinois;
Upper Coal Measures.

INVERTEBRATES. Bist |

GASTEROPODA.
Genus PLEUROTOMARIA, Defrance, 1826.

(Dict. Sci. Nat., xli, p, 381.)

PLEUROTOMARIA SUBCONSTRICTA, M. and W.
Pl. 28, figs. 6a, 60, Ge.

Pleurotomaria subconstricta, Manx and Wortuen, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 458.

SHELL small, conical-subovate, longer than wide; spire mod-
erately elevated. Volutions five and a half to six, obliquely
flattened or concave above, excepting near the suture, where
there is a subangular prominence occupied by a series of small
folds or nodes. Body whorl forming rather more than half the
entire length, biangular around the middle, the lower angle
being less prominent and more obtuse than the other, and not
exposed on the'‘spire, while the other passes around near the
middle of each upper turn; between the two angles, the middle
of the body volution is vertically flattened, or a little concave,
while its under side is convex. Suture linear, but occupying
a rather distinct, somewhat rounded constriction or depression.
Aperture broad, subovate, or subcircular. Columella rather
arcuate, not perforated. Surface ornamented by about fifteen
revolving lines, some ten or twelve of which occupy the under
side of the body whorl, where they are larger than above;
crossing all these lines, are extremely fine, closely arranged
transverse striz, which, on the under part of the body turn,
show a tendency to cluster into small, regular wrinkles. Spiral
band narrow, flat, and located just above the middle angle.
Length, 0.33 inch; breadth, 0.24 inch; apical angle nearly
regular; divergence, 65°.

As near as we have been able to determine from a brief written description,
unaccompanied by figures, this species would seem to be related to P. Prout-

352 PALEONTOLOGY OF ILLINOIS.

tana, Shumard (Trans. Acad. Sci. of St. Louis, vol. 1, p. 15), but as Dr. 8.
gives 43° as the divergence of the spiral angle of his species, while that of
eur shell measures about 65°, it is scarcely possible that they can be identical.
Dr. S. also describes the revolving striz as being finely granose on the under
side of the body whorl in P. Proutiana, which is not the case with the species
now before us—though they are sometimes apparently obscurely crenulated by
the crossing of the small transverse wrinkles formed by the elustering of the
strie of growth.

Locality and position : Hodges creek, Macoupin county, Illinois; Lower Coal
Measures.

PLEUROTOMARIA SPECIOSA, M. and W.

Pl. 28, figs. 5a, 56, 5e.
Pleurotomaria speciosa, MnuxK and WorrTueEn, -Oct., 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 459.

SHELL attaining nearly a medium size; length slightly greater
than the breadth; volutions seven to seven and a half, last one
forming about half the entire length,-all subangular just below

the suture, thence obliquely flattened, or a little concave, to a ~

distinct revolving carina, a little below the middle of the upper
turns, and about the middle of the body whorl. Below this
second much stronger angle, the outside of the last turn is
vertically flattened, or somewhat concave, so as to produce a
third more obtuse revolving prominence below the middle—
beneath which the under side of the whorl is convex, but not
ventricose. Suture well defined. Spiral band narrow, promi-
nent, occupying and partly forming the middle revolving angle,
neatly crenulated, like the milled edge of a piece of coin.
Aperture subcircular, approaching a subquadrate outline; um-
bilicus small or nearly closed. Surface ornamented by eighteen
to twenty-two thread-like revolving lines, about twelve of
which occupy the under side of the body whorl, four to seven
the upper slope, and two or three the outer flattened space
around the middle. Crossing all these, there are numerous
extremely fine, very regular, closely arranged, transverse lines,

INVERTEBRATES. 303

about every fourth or fifth one of which is considerably larger
and more prominent than the others near the suture above;
and they all curve obliquely backwards as they approach the
angle supporting the spiral band. Length, 0.55 inch; breadth,
0.52 inch; apical angle regular, divergence 82°; breadth of
spiral band not more than about 0.03 inch.

This very neat, elegantly ornamented species, will be readily distinguished
from any of those yet known in our Coal Measures (resembling it in form), by
its peculiar prominent, neatly crenulated spiral band, and its extremely fine,
closely arranged lines of growth.

Locality and position: Same as preceding.

PLEUROTOMARIA ScITULA, M. and W.

Pl. 28, figs. 9a, 9, 9c, 9d.

Pleurotomaria scitula, Merk and WorrTHEN, Oct., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 461.

SHELL small, trochiform, length and breadth nearly equal;
spire depressed-conical; volutions six, a little convex, last one
prominent and narrowly rounded, or subangular on the peri-
phery, slightly convex below; suture somewhat canaliculate ;

- aperture subcircular, approaching a subquadrate form; umbili-

cal region impressed, but not distinctly perforated; spiral band
of moderate breadth, concave, and located a little above the
periphery of the body whorl, but passing around, slightly below
the middle of the other volutions. Surface ornamented by
from about seventeen to twenty-two revolving lines, only three
or four of which occupy that part of the body whorl above the
band, where they are larger and more widely separatéd than
below; distinct, but much smaller, regularly arranged, thread-
like lines, mark the volutions transversely. Length and
breadth each about 0.22 inch; apical angle convex, diver-
gence, 79°.

=A Spr. 25, 1866.

Oo

54 PALEONTOLOGY OF ILLINOIS.

This handsome, symmetrical little shell has much the form and general ap-
pearance of a Solarium, excepting that it has no umbilicus, and possesses the
peculiar spiral band characteristic of the genus Pleuwrotomaria. On the upper
part of the whorls, the transverse strize crossing the revolving lines are very
regularly arranged, at intervals a little greater than their own breadth, but in
crossing the spiral band they become more crowded, and curve gracefully back-
wards, parallel to the sinus of the lip. They are also rather closely and very
regularly arranged on the under side of the body whorl.

Locality and position: Same as last.

PLEUROTOMARIA BRAZOENSIS, Shumard?
Pl. 28, figs. la, 18, 1¢, 1d.
Pleurotomaria brazoensis, SHUMARD, 1860. Trans. St. Louis Acad. Sciences, i, p. 624.

SHELL rather under medium size, trochiform, height and
breadth nearly equal. Volutions five and a half to six,
obliquely flattened or a little concave above; last one com-
posing about half of the entire length, flattened or slightly
convex below, and very prominent around the middle, where
it is provided with two nearly equal caring, between which is
located the band of the sinus. On the spire only the upper of
these carinee is seen above the suture. Just below the well
defined suture the upper edge of the whorls is a little thick-
ened so as to form a subangular prominence, which is provided
with a series of small, obscure nodes. Aperture subquadrate
or subrhombic; columella perforated. Surface ornamented by
about twenty-five small, thread-like, revolving lines, some
twelve or thirteen of which occupy the underside of the body
whorl; crossing all these are numerous similar, equidistant,
transverse striae, the whole forming a regular cancellated style
of ornamentation. Length, 0.43 inch; breadth, 0.41 inch;
spiral angle nearly regular, divergence, 70°.

Being in doubt whether or not this species is really identical with Dr. Shu-

mard’s P. brazoensis, we have preferred to describe our specimens instead of
quoting his carefully written diagnosis. They seem to agree very closely with

se

INVERTEBRATES. 300

the characters given by him, unless by the “thirteen to fourteen rather strong
filiform strive” he mentions as ornamenting the whorls, he intends to convey
the idea that this is the entire number of these lines seen on any one whorl,
including those on the under side of the body volution; in which case we
should scarcely entertain a doubt in regard to our shell being a distinct species,
Since it uniformly has about double that number of revolving striz on the
last whorl. Dr. S. also describes the two sets of striae as “giving the surface
a handsome, crenulated appearance.” The word “crenulated” here is probably
amisprint; at any rate it is not applicable to the species before us, the strie of
which are not crenulated, but form a neat, cancellated style of sculpturing hav -
ing much the appearance, as seen under a magnifier, of a piece of musquito
netting pasted upon a smooth surface,

Should the shell under consideration prove to be distinct from that deseri-
bed by Dr. Shumard, which is not improbable, we would propose to designate
it by the name of Pleurotomaria intertexta.

Locality and position: Hodge’s creek, Macoupin county, Illinois; Lower
Coal Measures.

PLEUROTOMARIA TENUICINCTA, M. and W.

Pl. 28, fig, 3a, 3b, 3c, 3d.

Pleurotomaria tenuicincta, Munk and Wortun, October, 1860. Proceed. Acad. Nat.
Sci., Philad., p. 459.

SHELL small, conical-ovate; spire moderately elevated; volu-
tions seven, obliquely flattened or concave above, convex and
more or less distinctly angular around the middle, last one
prominently rounded below; suture distinct; spiral band very
narrow, concave, located a little above the middle of the
body whorl, and passing around rather below the middle of the
others; aperture apparently subcircular; umbilical region
indented, but apparently not distinctly perforated. Surface
ornamented by about fifteen to twenty, rather distinct revolv-
ing lines, only two or three of which occupy the flattened or
concave upper slope above the band, where they are less promi-
ment than the others; while the two forming the margins of
the band are more salient than any of those below. Fine,

356 PALAONTOLOGY OF ILLINOIS.

regularly arranged strie, which are much more distinct near
the suture on the upper slope than below the band, mark the
whorls transversely. Length, 0.24 inch; breadth, 0.20 inch ;
apical angle adittle convex, divergence 60°.

We have seen but a single specimen of this little shell, yet it differs suffi-
ciently from all the other species we have met with from these rocks, to be
readily distinguished. Amongst its most marked peculiarities, that may be
mentioned, are the prominently rounded, or ventricose character of the under
side of its body whorl, and the extreme narrowness of its spiral band, with its
prominent marginal caringz. We know of no species very closely allied to
it from foreign localities.

Locality and position: Springfield, Illinois; Upper Coal Measures.

PLEUROTOMARIA GRANULO-STRIATA, M. and W.

Pl. 28, fig. 2a, 26, 2c, 2d.

Pleurotomaria granulo-striata, Muzx and WortHEN, October, 1860. Proceed. Acad. Nat.
Sci., Philad., p. 459.

SHELL very small, conical-subovate, or subtrochiform ; spire
moderately elevated ; volutions compressed-convex, last one
prominently rounded or subangular around the middle ; suture
well defined; aperture apparently subcircular; spiral band
not distinctly defined, located near the middle of the body
whorl, and passing around just above the suture on the other
turns; calumella imperforate; surface ornamented by about
twelve or thirteen comparatively distinct revolving lines, eight
of which occupy that portion of the body whorl below the
band, where they are a little smaller and more closely
arranged than above.

On the upper sloping side of the whorls, the three or four
revolving lines occupying that part of the shell are crossed
obliquely by transverse lines, which are so much stronger on
the revolving striz than between them, that they present the
appearance of small nodes or granules at the points of crossing.

—. .

* ay

INVERTEBRATES. Bish

A revolving line occupying the middle of the spiral band, is
more prominent than the others, and obscurely crenulated.
Length, 0.17 inch; breadth, 0.15; apical angle regular, diver-
gence 60°.

. The interrupted or granulose appearance of the striz on the upper sloping
side of the whorls in this little shell, will readily distinguish it from any other-
wise similar species with which we are acquainted, in ourrocks. In form and
general appearance it resembles some of the species described by Prof. de Kon-
inck and others in foreign works, but it differs in the details of its surface
ornaments.

Locality and position: Macoupin county, Illinois; Lower Coal Measures.

PLEUROTOMARIA PRATTENI, M. and W.

Pl. 28, fig. Ta, 76, Tc, Td.

Pleurotomaria Prattent, MnEK and WorTHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 459.

.SHELL very small, conical-ovate, the breadth being about
two-thirds the length; spire rather elevated, but not acute at
the apex; volutions six to six and a-half, slightly convex, in-
creasing gradually in size, those of the spire more or less dis-
tinctly angular around the middle, last one sometimes slightly
flattened around the most prominent part of the middle, just
below the indistinct angle, and convex on the under side;
suture well defined; spiral.band of moderate breadth, flat, or
sometimes slightly concave, occupying the middle of the body
whorl, and passing around so as to bring its lower margin a
little above the suture on the other turns. Aperture subcir-
cular; columella imperforate; outer lip thin, sinus deep and
comparatively narrow. Surface ornamented by about eighteen
to twenty very fine revolving strize, some twelve or thirteen of
which occupy the body whorl below the band, where they are
a little larger than those above the angle, and more regularly
arranged; lines of growth extremely minute and obscure.

358 PALHONTOLOGY OF ILLINOIS.

Length, 0.24 inch; breadth, 0.18 inch; apical angle convex,
divergence, 37°.

The most marked peculiarity of this species is the fineness of its surface

markings, particularly the lines of growth, which are scarcely visible even by |
the aid of a common lens. The revolving striz, although much larger than

those crossing them, are not distinctly seen without the use of a magnifier.
Generally the carina on the middle of the upper whorls is well defined, but it
becomes less distinct on the body volution. The measurements given above
are from an adult specimen slightly above the medium size.

The specific name of this beautiful little shell was given in honor of our
lamented friend, Henry Pratten, Hsq., deceased, formerly of the Illinois Geo-
logical Survey.

Locality and position: Same as last.

PLEUROTOMARIA SUBSINUATA, M. and W.
Pl. 28, figs. 4a, 43, 4c, 4d.

Pleurotomaria subsinuata, MuEK and WortueEn, Oct., 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 460.

SHELL under medium size, conical-ovate; spire rather ele-
vated; volutions six, convex, last one in mature shells some-
times obliquely flattened a little above, just below the suture,
thence rounded below; suture well defined ; spiral band narrow,

. prominent, angular, located above the middle of the body whorl,
at the lower edge of the slight flattening of its upper side, and
passing around the middle of the upper turns; sinus of the lip
shallow, judging from the slight curve of the lines of growth ;
aperture nearly circular; columella not distinctly perforated.
Surface ornamented by about fifteen distinct revolving lines,
some three or four of which on the middle are larger than those
above, while those below gradually diminish in size towards

the small umbilical impression; only two or three of the smaller —

lines usually occupy the slightly depressed portion of the
whorls above the spiral band, where they are crossed obliquely
by a series of regularly arranged wrinkles; lines of growth ex-

q
‘
‘
4

INVERTEBRATES. 359

tremely fine and very obscure. Length of largest specimen,
0.40 inch; breadth, 0.31 inch; apical angle convex, diver-
gence, 50°.

The spiral band of this species is so little apparent that we were at first in
doubt whether it really belongs to the genus Plewrotomaria. On examining
carefully, however, by the aid of a lens, the obscure lines of growth, we observe
that they make a small but distinct backward curve in crossing the upper of
the three or four larger revolving lines passing around the middle of the body
whorl, so as to indicate the presence of a shallow sinus in the lip at the termi-
nation of this revolving line. The band of the sinus being angular or carinated,
and scarcely larger than the other revolving lines, would not be distinguished
from them, where the surface has been a little weathered so as to obliterate the
obscure striz of growth.

The surface markings will at once distinguish this shell from any of its asso-
ciates, and we know of no foreign forms with which it is lixble to be confounded.

Locality and position: Same as preceding.

PLEUROTOMARIA TURBINIFORMIS, M. and W.

Pl. 28, fig. 8a, 8b, 8c.

Pleurotomaria turbiniformis, Mnnx and WortHeEn, Oct., 1860. Proceed. Acad, Nat. Sci.,
Philad., p. 461.

Pleurotomaria bicarinata, McCuusney, Feb., 1860. New Paleozoic Fossils, p. 90; (not
P. bicarinata, Sowerby, sp., 1818, de Koninck, 1843, nor of Munster, 1844).

SHELL rather large, trochiform; height and breadth nearly
equal; spire conical, moderately depressed; volutions about five
and a half, flat, last one distinctly angular around the periphery,
and flattened or slightly convex below; umbilical region a
little concave; umbilicus very small, and bound by a small,
obscure, revolving ridge; spiral band extremely narrow,
grooved, occupying the angle around periphery of the body
whorl, and passing around scarcely above the suture on the
other volutions, margined above and below by a sharply eleva-
ted line; suture linear, having a somewhat banded appearance
in consequence of the development of a rather distinct revolv-
ing line at the upper margin of each whorl; aperture appa-

360 PALEONTOLOGY OF ILLINOIS.

rently rhombic-subquadrate in form. Surface-ornamented by
about twenty obscure, closely arranged, revolving strize, crossed
by stronger, very regular transverse lines, which are most
distinct on the upper part of the whorls, and pass with a
gentle curve backward and outward to the spiral band. Below
the angle the under side of the body whorl is nearly smooth,
or only marked by very obscure lines of growth, and faint
traces of revolving striz. Length, about 0.93 inch; breadth,
nearly 0.97 inch; apical angle regular, divergence 64°.

This shell seems to be very closely allied to P. Riddelii, of Shumard (Trans.
Acad. Seti. St. Louis, vol. i, p. 625), and a more careful comparison with his_
description leads us to suspect that it may possibly prove identical. Yet, as
Dr. S. describes his species as having only twelve or thirteen revolving lines
on each whorl, while our shell shows uniformly nearly double this number, we
are in doubt whether they should be considered identical or not. It is also
related to Plewrotomaria missouriensis=(Trochus missouriensis, Swallow), but
never attains near so large a size as that noble species, from which it also
differs in having much stronger transverse strize ; while Prof. Swallow’s species
has not the prominent linear ridge just above and below the spiral band, seen
in our shell.

At the time we first published our description of this species, we had not

_seen Prof. McChesney’s paper in which he published it under the name P.
bicarinata, nor had we any knowledge of its publication until about the 10th
of March, 1860. Our paper was published Nov. 24th, of the same year.
These dates are of no consequence, however, so far as the species under con-
sideration is concerned, since the name under which Prof.. McChesney pub-
lished it, had been previously used for three other species, the first as far back
as 1818.

Locality and position: Sasalle, Illinois; Upper Coal Measures.

PLEUROTOMARIA SUBSCALARIS, M. and W.
Pl. 28, figs. 10a, 100 (by error on the plate, 9a, 9b).

Pleurotomaria subscalaris, MnEK and WortHEN, October, 1860. Proceed. Acad. Nat.
Sci., Philad., p. 460.

SHELL large, rather thick, conical-ovate ; spire moderately
elevated; volutions six, those near the summit of the spire

INVERTEBRATES. 361

flattened, the others convex, and provided with a distinct,
rather sharp, apparently smooth carina, which occupies a posi-
tion a little above the middle of the body whorl, passes around
near the middle of the second, becomes lower on the third, and
sinks below the suture on the others. Below this angle there
is on the body volution a second less distinct subangular promi-
nence, with a broad, vertical, nearly flattened or slightly con-
cave space between the two. Under side of last turn a little
convex; umbilical region somewhatindented, but not perforated;
suture well defined. Spiral band narrow, and occupying the
principal angle of the whorls. Length, 2 inches; breadth,
1.83 inches; apical angle convex, divergence, 70°.

Our specimen is somewhat eroded, but it retains traces of about twenty
rather strong revolving lines, eight or nine of which occupy the upper side of
the whorls, above the carina, some three or four the flattened outer side of the
body whorl, and the remainder the under side. On the upper sloping surface
of the whorls there are also regularly arranged, oblique transverse strize, which,
in well-preserved specimens, are probably continued upon the outer and under
sides of the last turn.

This fine species might be confounded, on a hasty examination, with
P. tabulata of Conrad, with which it agrees in size and some other respects.
It differs, however, in having the upper part of the spire much more depressed,
and without any angle visible above the suture. The principal angle on its
other turns appears to differ in being less prominent, and destitute of the crenu-
lations so distinctly seen on that of P. tabulata. In addition to these differences,
the substance of the shell under consideration is much thicker than in that
described by Mr. Conrad.

Locality and position: Hodge’s creek, Macoupin county, Illinois; Lower Coal

Measures.

PLEUROTOMARIA? TUMIDA, M. and W.

L Pl. 31, fig. la, 16.
Platyostoma? tumida, Manx and Wortuen, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 463.
SHELL rather large, very thin, rhombic subovate in outline,
a little longer than wide; spire much depressed or nearly flat;
AG Supr. 26, 1866.

a

362 PAL.ZONTOLOGY OF ILLINOIS.

volutions four to four and a-half, convex, increasing very rapidly
in size; last one large, forming about eight-ninths of the entire
length, prominent, and narrowly rounded above the middle,
slightly convex on top, and contracted and somewhat extended
below; suture well defined; aperture large, longer than wide,
obovate, the inner side being straighter than the other; lip
very thin; columella perforated?; surface (of an exfoliated
specimen) retaining traces of rather strong revolving lines.
Length, 1.24 inches; breadth, 1.20 inches; length of aperture,
1.05 inches; breadth, about 0.65 inch; apical angle regular,
divergence, 1.32°.

We are in much doubt in regard to the generic relations of this shell, not
haying seen specimens in a condition to enable us to determine whether or not
it possessed the spiral band and sinus in the lip, so characteristic of the genus
Pleurotomaria. It certainly differs materially from the usual forms of the
species of that genus, having more the outline of the recent genus Janthina.
We suspect it will prove to belong to an undescribed genus, which should pro-
bably include a Russian form figured by Murchison de Verneiul and Keyser-
ling, in the Geology of Iussia, pl. xxiii, fig. 14, as an undetermined Janthina.
Ifso, we would propose for the group the name Janthinopsis, from its resem-
blance to the genus Janthina.

We cannot believe that Carboniferous shells such as this can he properly
referred to the recent genus Janthina, since no species of that genus are known
from any of the succeeding rocks, until we ascend to the most recent Tertiary
beds; nor can we agree with d’Orbigny in placing them in the Lower Silurian ge-
nus Scalites, which was founded upon thick shell, with distinctly angular whorls.

Locality and position: Grayville, Illinois; Upper Coal Measures.

Genus STRAPAROLLUS, Montfort, 1810. (See page 158.)
(Conch. Syst., ii, p. 174.)

STRAPAROLLUS UMBILICATUS, M. and W.
Pl. 29, figs. la, 1, le.

Straparollus umbilicatus, MrEx and WortTuHEN, Oct., 1860. Proceed. Acad. Nat. Sci.,
Phila‘d., p. 462.

SHELL of medium size, depressed subtrochiform; spire rather
elevated for a species of this genus; volutions five to five and

INVERTEBRATES. 363

a half, convex, increasing gradually in size, nearly horizontally
flattened on the upper side, about half way across from the
suture, where there is a rather distinct revolving angle; below
this angle the upper oblique outer slope is slightly flattened to
near the middle of the outer side, which, in the last whorl, is
rather narrowly rounded; under side of last turn rounded to
a moderately distinct angle within the middle, thence rounding
into the umbilicus; umbilicus large, or nearly twice as wide as
the diameter of the last whorl near the aperture, very deep,
and permitting the inner side of all the volutions to be seen to
the summit of the spire. Surface marked by fine, rather
obscure or moderately defined lines of growth. Height, 0.88
inch; breadth, 1.15 inches; breadth of umbilicus, measuring
across from its marginal angle on opposite sides, 0.68 inch;
apical angle convex, divergence about 100°.

This species is evidently closely allied to Straparollus acutus=( Cirrus acutus,
Sowerby, Min. Conch., pl. 141, figs. 1 and 2), but has a proportionally wider
umbilicus and narrower whorls, while the angle on the under side of its last
whorl is farther in, so as to form the margin of the umbilicus. Its lines of
growth are also less strongly marked, those of S. acutus, being described by
de Koninck as forming even imbricating laminz on the last turn.

Locality and position: St. Clair county, I]. ; Lower Coal Measures.

Genus NATICOPSIS, McCoy, 1844.

(Carb. Foss. Ireland, p. 33.)
Synon.—WNatica, of some authors ; (not of Aadanson).

SHELL oval or subglobose, solid, imperforate, composed of
few, convex, rapidly expanding whorls, the last one of which
is large; spire short; aperture broadly subovate, straighter on
the inner side, and rounded below; columella callous, more
or less distinctly flattened, and often showing a longitudinal
impression for the reception of the edge of the operculum ;
sometimes transversely furrowed or striated; lip sharp and
entire. Surface generally nearly smooth on the middle and

364 PALZONTOLOGY OF ILLINOIS.

lower part of the whorls, and marked with more or less strongly
defined, regular, oblique strize or costze near the suture above,
rarely passing down upon the middle and lower part of the
body whorl; sometimes covered with small nodes or granules.

This genus, as we understand it, includes at least three rather marked sec-
tions, which may be defined as follows:
1. NATICOPSIS, (proper.)
Shell smoother, excepting oblique strie parallel to the lines of growth, near the
suture.
N. Phillipsit, McCoy,* NV. ventrica, Norwood and Pratten, Watica plicistria,
Phillips, etc. :

2. ——
Shell with oblique, strong striz or costz, most distinct near the suture, but
well defined over tlfe whole body whorl. f
Nerita subcostata, Goldf.; Littorina biserialis, Phillips, etc. iy ;
3. TRACHYDOMIA, Merx and Woxrtsen. (teazous, rough ) Owpa, a house. )

Shell with surface ornamented with small, more or less regularly disposed, j
nodes or granules.
Naticopsis nodosa, Meek and Worthen;+ WV. (Lrachyd.) Wheeleri—(Littorina
Wheeler, Swallow) ; Natica Mariz, Murchison, deVern. and Keys.; Buceiuwm
breve, Sowerby, etc. 7
In redefining this genus at a later date, in his valuable work on the British |

Palzxozoic Fossils, p. 301, Prof. McCoy describes it as having “a minute um-
bilicus, only seen in the east.” As we have had an opportunity to examine
numerous fine specimens of several species of this genus, without seeing any
traces of a perforation in the columella, we can but regard the minute um-
bilicus mentioned by Prof. McCoy in the cast, as merely the cavity left in it
by the columella itself. : |
The shells of this genus often have so much the aspect of some types of the
Neritidx, that we were at one time under the impression that they must belong
to that family. On breaking open a number of specimens, however, of various
species, and finding that the inner whorls are not absorbed away as in the Neri-
tidx, we were led to doubt the correctness of that conclusion, and since seeing
numerous specimens of opercula found associated with these shells in our Coal
Measures, under circumstances scarcely admitting of a doubt that they belong
to them, we have-been confirmed in the opinion that this genus must belong to
some other family. The opercula alluded to, have exactly the form and size
corresponding to the aperture of typical species of Naticopsis, with which they

* This being the first species mentioned by McCoy, and agreeing best with his diag- —
nosis, may be regarded as the type of the genus. .
{ We regard this as the type of this subgenus.

— as lS ee ee ee

INVERTEBRATES. 365

are associated, while they do not so agree with that of any other univalves
known in the same rocks. They are moderately thick and shelly, oval or sub-
circular in form, with a lateral or submarginal nucleus, and show not the slight-
est traces of the spiral or subspiral stricture, and articulating projection, so charac-
teristic of the Neritidx. On the inner side they show a distinct reniform scar
of attachment, and on the outside the fine, but distinctly concentric, lines of
growth. It will also be remembered, that Prof. McCoy figured a specimen of
Naticopsis Phillipsi, in his “‘ Carboniferous Fossils of Ireland,’ with an oper-
culum within its aperture, and that it shows no indications of a spiral structure.

From all that is therefore known in regard to this genus, we are also inclined
to doubt the propriety of referring it either to the Naticidz or Littorinidex, and
to believe it will be found to be the type of an extinct family Maticopsidx, near
the Naticide.

We are not sure this genus occurs in the Silurian rocks; a few Devonian
species seem to belong to it, but it attained its maximum development during
the deposition of the Carboniferous deposits. It is also apparently represented
by a few species in the Permian rocks.

NATICOPSIS NANA, M. and W.
Pl. 31, figs. 4a, 46.

Platyostoma nana, Munx and WortHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 463. ea

SHELL small, subglobose, wider than high, spire much de-
pressed; volutions three, increasing very rapidly in size, last
one large and ventricose; suture well defined ; aperture large,
broad-subovate, somewhat straightened on the inner side,
equaling near seven-eighths the entire length of the shell;
outer lip thin; inner lip not much thickened; columella
slightly flattened. Surface marked by fine lines of growth,
but slightly stronger and more regular near the suture on the
upper side of the whorls. Length, 0.19 inch ;’ breadth, 0.21
inch ; length of aperture, 0.15 inch; breadth of ditto, 0.11 inch;
apical angle about 123°.

Since describing this little shell, we have succeeded in clearing the matyx
from the columella, which we find presents the characters of Naticopsis. It is

366 PALEONTOLOGY OF ILLINOIS.

a neat, symmetrical little species, somewhat resembling Nerita spirata, Sowerby,
excepting that its spire is not so much depressed, while the upper side of its
whorls are not flattened. Itis proportionally shorter and more ventricose than
Naticopsis ventrica=(Natica ventrica, Norwood and Pratten), from which it
also differs in not having its body whorl constricted around the middle.

We have before us a number of specimens from the Lower Coal Measures on
Hodge’s creek, Macoupin county, Illinoisjspresenting almost precisely the same
form and general appearance as the species under consideration, but differing
in attaining three or four times as large a size, and in having the thickened
columella sometimes transversely striated. It is possible the species here
described may be identical with these, but we think the specimens alluded to
from Hodge’s creek, the young of a large ponderous species quite common at the
same locality. Ifso it would seem scarcely possible that the little shell here
described, from the Upper Coal Measures, can be the same species.

In our figure of the species under consideration, the engraver has, by some
accident or mistake, carried a ridge around the inner upper side of the aper-
ture, which gives it an unnaturally rounded appearance above.

Locality and position : Upper Coal Measures, Springfield, Illinois.

Surcenus TRACHYDOMIA, M. and W. (See page 364.)

NAticopsis NoposA, M. and W.
Pl. 31, fig. 2a, 26.

Naticopsis nodosa, Merk and WorTHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 463.

SHELL rather large, obliquely subrhomboidal in outline,
rather thick; volutions four and a half, convex, increasing
rapidly in size, last one large, gibbous, and composing three-
fourths of the entire length, rounded on the outer side, and
having a shallow revolving depression near the suture above ;
suture moderately distinct ; aperture rounded subovate, some-
what straightened on ‘the inner side; lip sharp; columella
distinctly flattened, smooth, and having a small opercular
groove near the base, not perforated. Surface ornamented by
numerous prominent nodes, which are arranged in quincunx,
so as to form oblique rows nearly parallel to the lines of growth,

INVERTEBRATES. 367

which are fine, rather regular, and scarcely deflected from
their course by the presence of the nodes. Length, measuring
from the most extended part of the aperture obliquely to the
apex of the spire, 1.08 inches; breadth, 0.98 inch; apical angle
convex, divergence about 100°.

Locality and position: St. Clair county, Illinois ; Lower Coal Measures.

NATICOPSIS NODOSA va7. Ho~LipAyi, M. and W.
Pl. 31, fig. 3a, 30.

Naticopsis Holidayi, Mnunx and Worruen. October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 463.

Tuis agrees so nearly with the last, that we doubt now, the propricty of
regarding it as a distinct species. It only differs in having its columella more
broadly flattened, and its nodes more numerous, and more crowded. In the
figures of both of these forms, the engraver has made the nodes to appear to
arise too abruptly from the surface of the shell. They are all more spreading at
the base. Length, 1.24 inches; breadth, 1.10 inches; apical angle nearly
regular, divergence 100°. pe

Locality and position: Hodge’s creek, Macoupin county, Illinois; Lower
Coal Measures.

GreNuS MACROCHEILUS, Phillips.

Synon.—Buccinum (sp.), Sownrsy and others; (not of Linnzus).
Macrocheilus, Puinurrs, 1841. Paleozoic Fossils, p. 103; (not Kirby, 1838,
genus Coleoptera).
Plectostylus, Conrad, 1842. Journal Acad. Nat. Sci., Philad., vol. viii, p. 275;
(not Beck, 1837).

SHELL subglobose or more or less elongate; spire pointed at
the apex, and composed of several smooth, moderately convex
volutions; body whorl large; aperture ovate or subovate, rounded
and sometimes slightly effuse below and angular behind; colu-
mella imperforate; outer lip thin, and without notch or sinus;
inner lip thin or wanting above the middle of the aperture,

368 PALEONTOLOGY OF ILLINOIS.

more or less thickened, and generally twisted into an obtuse
fold below.

_As originally proposed by Phillips, this genus was made to include, in addi-
tion to the typical forms, species belonging apparently to our genus Sohenterns
and to Naticopsis of McCoy. If we were to follow the rule adopted by some,
of always regarding the first species described by an author, under a new generic
name, as the type of the genus, we would have to take Buccinwm breve, of
Sowerby, as the type of Macrocheilus, that being the first species described by
Phillips. And as that shell seems to be a nodose species of McCoy’s subse-
quently proposed genus Naticopsis, we would probably have to substitute the
name Macrocheilus for the Naticopsis group. As Phillips, however, only re-
ferred the B. breve provisionally to his genus, and distinctly states that he
thought it allied to Natica, and the species B. arculatum and B. imbricatum to
his genus Loxonema, while he says he regards the other species as “alone suffi-
ciently peculiar to deserve a generic title,” it is evident he did not view any of
those just mentioned as typical examples of his new genus. Consequently we
must look for the type amongst the other included species, which are Buccinum
acutum, Sowerby, and Macrocheilus elongatus and M. harpula, Phillips.* Hence
de Koninck, and others who first followed Phillips in the use of this generic
name, have regarded J. acutus and other congeneric species as typical forms;
which conclusion has been adopted generally amongst Palzeontologists. Con-
sequently in proposing the clearly distinct genus Soleniscus (probably including
M. elongatus of Phillips), we adopted the generally accepted opinion in regard
to the particular group for which the name Macrocheilus should be retained, as
had also been done by McCoy in proposing his genus JVaticopsis.

As thus understood, Phillips’s genus includes those rather thick, smooth,
subglobose, oval, or more or less fusiform shells, with convex whorls, an oval
aperture, neither distinctly notched nor provided with a canal below, and a
more or less callous inner lip, usually twisted into an obtuse revolving fold on
the imperforate, somewhat flattened columella, such as MZ. acutus, Sowerby (sp.),
M. primigenius, Conrad (sp.) ,M maculatus, de Koninck, JM. ventricosus, Hall,
M. Newbery, Stevens, etc. These shells vary considerably in the elevation of
the spire, though it is always acute at the immediate apex, even when depressed.
In texture, smoothness of surface, the thickening and often obtusely folded
character of their inner lip, as well as in general appearance, they remind one
of those ponderous Cretaceous and Jurassic shells often referred to Actxonella;
such for instance as A. Reynauxiana, d’Orbigny, A. obtusa and A. elliptica,
Zekeli, upon which one of the writers has proposed to found a distinct genus,

* He also included M.? neglectus, Phillips; but as he did so with a query, we could
not view it as one of the intended typical species.

:

INVERTEBRATES. 369

Trochactxon.* The Carboniferous species of Macrocheilus were doubtless origi-
nally handsomely colored shells, since a species described by de Koninck, from
the Carboniferous rocks of Belgium (J. maculatus), retains rows of. large
rectangular, oblong spots, like some of the modern Mitras and Cones. ‘
~The elongated species of this genus are not always easily distinguished from
certain forms of Polyphemopsis, especially when the aperture and columella
cannot be seen. They, however, differ entirely in their thickened inner lip,
usually provided with an obtuse fold, and in generally having the body whorl
proportionally larger. They also differ in having a larger aperture, which is
more rounded below. From ZLoxonema, with which they are sometimes
confounded, they are distinguished by their more callous inner lip, with
its fold or ridge, their usually less elongated spire, and smooth surface.{

So far as known to us, the genus Macrocheilus seems to have been introduced
during the Devonian epoch, and attained its maximum development during the
deposition of the Carboniferous rocks, particularly the Coal Measures. Prof.
King refers to it an elongated shell from the Permian rocks of England (J.
symmetricus), resembling some species, apparently of this genus, from the Coal
Measures of the Western States, excepting that its columella seems not to be
thickened, and its lines of growth have a flexure more like we see in Loxonema,
to which genus it may more properly belong. We cannot remember any Triassic
species, though it is not improbable that the genus was represented during that
epoch.

Mr. A. Adams refers to this genus a recent shell from the coast of Japan,
under the name I. japonicus (Ann. and Mag. Nat. Hist., 1860, p. 407), and
says it agrees almost exactly, in form, with M. acutus, but has no fold on the
columella, which is thickened. Notwithstanding its close resemblance to the
type of the genus Macrocheilus, we may reasonably doubt its identity with that
genus, of which we have no authentic examples from the Jurassic, Cretaceous
or Tertiary rocks.

It is not improbable that the rules of nomenclature may require, that the
name of this genus shall be changed, because it had been previously used for
a genus of Coleoptera. Mr. Conrad’s genus, Streptostylus, was evidently
founded upon internal casts of one or two species of this genus; and his name
might be retained for it, in case it should be thought desirable to make a
change, were it not for the fact that it was proposed for another group of Mol-
lusks by Beck, in 1837. .

* See Am. Jour. Sci., xxxv, Sec. series, p. 89, for a paper on the Actzonidx, to which
family the genus Macrocheilus seems to belong.

+ By some error, Chenu figures Plewrotomaria Yvanii, Leveille, a spirally striated
shell (Conch., i, p. 228), as Macrocheilus acutus, Sowerby.

Any, Serr. 27, 1866,

PALZONTOLOGY OF ILLINOIS.

(Si)
“I
=)

MAcrocHEILUS MEDIALIS, M. and W.
Pl. 31, fig. 5a, 5d.
Macrocheilus medialis, Mpzx and WorTHEN, October, 1865. Proceed. Acad. Nat. Sci.,

Philad., p. 466.

SHELL of medium size, rather thick, rhombic-subovate ; spire
depressed conical, acutely pointed at the immediate apex, form-
ing about one-third the entire length ; whorls six to six and a
half, convex, increasing rapidly in size, last one large, but not
very ventricose, the widest part being near the middle; suture
moderately distinct ; aperture rather narrow subovate, or sub-
rhombic, acutely angular above, and narrowly round or slightly
effuse at the base of the columella below; outer lip sharp,
nearly straight in outline ; columella somewhat tortuous, and
more or less sinuous about half way up the aperture; inner lip
thickened to the top of the aperture, and showing a slight ten-
dency te form an obtuse fold or prominence just below the
sinuosity at the middle of the columella, marked by regular,
obscure, transverse wrinkles or strize above the middle. Sur-
face apparently smooth, but showing under a lens obscure traces
of fine lines of growth. Length, 1.17 inches; breadth, 0.83
inch; length of aperture, 0.72 inch; breadth of ditto, 0.37
inch; apical angle convex, divergence 83°.

On comparing what we believe to be authentic examples of Macrocheiles
primigenius, Conrad (sp.), sent by Dr. R. P. Stevens, from the Coal Measures
near Pittsburgh, Pennsylvania, with the form under consideration, we find that
they differ from our shell in having the body whorl more ventricose, the revoly-
ing fold on the columella more distinct, and the broad spiral furrow above it
deeper, and continued down around the base of the body whorl. These. Penn-
sylvania specimens, also show no traces of the small transverse wrinkles, or
strize, seen on the callous of the inner’ lip of our species above the middle of
the aperture.

The engraver did not follow carefully enough the shading of the drawing, in

fig. 5a, of our plate 31, representing the aperture of this shell. This defect
makes the columella look too flat and straight in the figure.

Locality and position: Upper Coal Measures; Springfield, Hlinois.

'
j
|

INVERTEBRATES. — 371

MACROCHEILUS INTERCALARIS, M. and W.

Pl. 31, fig. 6a, 65.

Macrocheilus intercalaris, Manx and WorrtueEn, October, 1860. Proceed. Acad. Nat. Sci.
- Philad., p. 467.
Macrocheilus pulchellus, Mnnx and WorrTHEN, Oct. 1860. Ib.

SHELL of medium size, rhombic-subovate; spire conical,
forming about one-third the entire length, pointed at the
extremity; volutions six to seven, compressed-convex, increas-
ing rather rapidly in size, last one comparatively large, but not
ventricose, widest near the middle, and compressed above;
aperture narrow subovate, acutely angular above, narrowly
rounded and slightly effuse below; outer lip sharp, a little
prominent along the middle; columella somewhat tortuous,
moderately callous, and provided with an oblique prominence
or obtuse fold near the middle of the aperture, sinuous just
above the fold. Surface smooth, but showing under a lens,
obscure traces or lines of growth. Length, 1.15 inches; breadth,
0.70 inch; length of aperture, 0.70 inch; breadth of ditto,
0.34 inch; apical angle convex, divergence 64°.

This species differs from the last, not only in being less ventricose, and in
haying the whorls less convex, but in having the callosity of its inner lip smooth,
instead of striated above the middle.. The differences of form are generally
more strongly marked than would appear from our figures 5a and 5), since a
majority of the specimens of NV. medialis have the body whorl proportionally
larger, and the spire shorter, than in the specimen represented by our figures
5a and 56, though that is much the best specimen we have seen.

We now regard the form we described under the name JM. pulchellus, as most
probably only a variety of the M. intercalaris. It is exceedingly difficult,
sometimes, to separate the species in this genus, since they are generally varia-
ble, and are sometimes very closely allied.

Amongst the specimens sent by Dr. Stevens from Pittsburgh, there are two
that we think belong to this species, as they agree well with its type in form
and general appearance, while they differ materially from those we regard as
M. primigenius, from the same locality.

Locality and position: Same as last; also from same horizon at Pittsburgh,
Pennsylvania.

wo
~I
bo

PALAONTOLOGY OF ILLINOIS.

MAcROCHEILUS, (undt.)
Pl. 27, fig. 10.

Or this shell we have only seen internal casts, none of which show the aper-
ture nor the columella; hence we cannot determine whether it is identical with
any of the described species or not. In form it seems to agree quite nearly
with M. primigenius, Conrad (sp.). The impression left by the columella, how-
ever, in the matrix, appears to show no traces of the obtuse fold seen on that
of Mr. Conrad’s species. It may be a new species, but we have thought it
would be better not to propose a new name for it until other specimens can be
obtained for examination. -

The appearance of an umbilicus in the figure is merely the cavity occupied
by the columella, the specimen being an internal cast, and the appearance of
fine, revolving striz on the body whorl, is an error in the engraving.

Locality and position: Bridge north branch Saline river, Gallatin county,
Illinois; Upper Coal Measures.

Grnus POLYPHEMOPSIS, Portlock.

Synon.—Buccinum (sp.), Sowerby, 1839. Murchisons Sil. Syst., p. 642; (not Linnzus,
1758).
Polyphemus (sp.), Sowerby, 18—. Geol. Trans. (2d ser.) vol. v, p. 492; (not
Montfort, 1810.)
Polyphemopsis, Portlock, 1843. Geo]. Londonderry, p. 415.
Bulimeila, Hall, 1856. Trans. Albany Inst., vol. iv; (not Pfeiffer, 1852).

SHELL subfusiform, spire more or less elongated, and usually
pointed at the apex; whorls flattened or somewhat convex,
last one moderately large, but not ventricose, generally forming
more than half the entire length, somewhat produced below;
outer lip simple, thin and nearly straight; inner lip wanting
(or sometimes a little developed below, and winding around up
the columella, so as to pass out of sight opposite the middle of
the aperture?); columella without folds or callosity, slightly
twisted or winding, curved outwards below to meet the outer
lip, at the connection with which it is usually truncated ; aper-
ture narrow subovate, in the typical species effuse, or slightly

a
=

INVERTEBRATES. 373

notched at the base of the columella ; surface smooth, or only
with obscure lines of growth.

The shells belonging to this group have generally been supposed to be related
to Achatina and Bulimus. They have not, however, as remarked by Col. Port-
lock, the obtuse mammillated apex of Achitina (Polyphemus), to which they
have been sometimes referred, while their smooth, or even polished surface—
only showing obscure lines of growth under a magnifier—gives them a differ-
ent aspect from any of the land shells with which they have been compared.
In addition to this, the fact that all their associates, both in this country and
in Kurope, are clearly marine types, is a sufficient evidence that they are not
related to any of these land shells. On the contrary, they seem rather to be
related to the Ulimide, or some of the allied families.

The Silurian group Subulites, Conrad, 1847, presents, so far as known, ap-
parently the essential characters of this genus, and if generically distinct,
evidently belongs to the same family. The close similarity of these types is
not so apparent in the particular species figured by us, as in P. elongata, of
Portlock (Geol. Lond., pl. 31, fig. 2), and P. fusiformis=(Polyphemus fusifor-
mis, Sowerby; Geol. Trans., vol. v, pl. xxix, fig. 26), both of which are typi-
eal Carboniferous species of this genus.

Where the aperture and columella cannot be seen, it is sometimes difficult to
distinguish these shells from elongated forms of Macrocheilus, from which they
differ in wanting the callosity and fold, or revolving ridge, of the columella,
characterizing that type, and in the truncated base of the columella. The lat-
ter character, and their smooth surface—destitute of the distinct curved striz
or costee,—distinguishes these shells from Phillips’s Loxonema.

The little shells upon which Prof. Hall proposed to found a genus Bulimelia,
agree exactly in all their generic characters with Polyphemopsis. It is true
they are much smaller than the types of that genus, such as P. elongata and
P. fusiformis, but if we were to make size a generic character in this instance,
we would have, on the same principle, to create new genera for nearly all the
shells found at the same locality, since they are almost all diminutive in size,
although presenting exactly the generic characters of Murchisonia, Pleurotoma-
via, Loxonema, Conularia, Conocardium, and various other genera. The species
described by Prof. Hall under the preoccupied name Bulimella, are Polyphe-
mopsis bulimiformis, P. canaliculata and P. elongata.

The presence of an inner lip below the middle of the columella, of some
species of this genus, is stated with doubt in our diagnosis, because we have
only seen it in one species (our P. peracuta), which may possibly not belong
properly to this genus. -

Unless this group includes Subulites, and some doubtful Devonian forms, it
would seem to be confined to the Carboniferous rocks.

374 PALEONTOLOGY OF ILLINOIS.

PoOLYPHEMOPSIS INORNATA, M. and W.
Pl. 31, figs. 8a, 86, 8c.

Loxonema inornata, Mrnx and Worruen, October, 1860. Proceed. Acad. Nat. Sci.

Philad., p. 463.

SHELL small, conoid-subfusiform ; spire moderately elevated,
pointed but not attenuate at the apex; volutions seven, nearly
flat, increasing rather gradually in size, last one somewhat
prominently rounded in the middle, but not ventricose, form-
ing about two-thirds the entire length; suture rather shallow ;
aperture narrow subovate, angular above and somewhat effuse
below; columella arculate and tortuous; outer lip thin, not
sigmoid in outline; surface smooth or only showing very
obscure traces of fine striz of growth under a good lens.
Length, 0.38 inch; breadth, 0.18 inch; apical angle convex,
divergence about 30°. Length of aperture, 0.16 inch; breadth
of ditto, 0.09 inch.

This species resembles our P. peracuta somewhat, but is much smaller. It
is also proportionally shorter, and has scarcely more than half the number of
whorls; while its volutions are rather more convex, and its spire not near so
slender, nor so pointed. It also wants the inner lip of that species. Our spe-
cimens have the lip broken at the base of the aperture, so as to make the figure
8a, appear as if the columella is more abruptly truneated, than is natural.

Locality and position: Springfield, Illinois; Upper Coal Measures.

POLYPHEMOPSIS NITIDULA, M. and W.
Pl. 31, fig. 9a, 90.

Loxonema nitidula, Muex and Wortuen, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 465.

SHELL of medium size, subfusiform ; spire elongated, conical,
rather attenuate and acutely pointed above; volutions eight
to eight and a half, rather convex, last one comparatively large,
composing less than two-thirds of the entire length, somewhat

INVERTEBRATES. 375

contracted and produced below; suture well defined, especially
between the lower whorls; aperture narrow-subovate, a little
oblique, acutely angular above; rather narrow, and apparently
provided with a small, rounded sinus at the base of the colu-
mella below ; outer lip thin and sharp, with a slightly promi-
nent margin; columella arcuate, and somewhat twisted below;
inner lip nearly or quite obsolete above. Surface smooth, but
showing under a magnifier extremely fine, obscure lines of
growth. Length, 1.10 inches; breadth, 0.43 inch; apical angle
regular, divergence 30°. Length of aperture, 0.47 inch;
breadth, 0.20 inch.

This species has much the form and proportions of Macrocheilus fusiformis,
Hall (Jowa Report, pl. 29, fig. '7), but seems to be more attenuate, and has a
rather more rapidly ascending spire. The figures given by Prof. Hall, however,
are from an imperfect specimen, and it is possible that when we can have an
opportunity to compare the aperture, it may be found necessary to include these
forms under one name, as more varieties of the same species. If so, that pro-
posed by Prof. Hall cannot be retained, for the reason that the name fusi/ormis
had been used, by Sowerby, for one of the typical species of this genus.

The form under consideration may be distinguished from the last described
species by its larger size, more slender and more pointed spire, deeper suture,
and more convex whorls. We have not seen a specimen with the lip quite per-
fect below; the one figured, owing to a fracture of the lip, makes the trunca-
tion of the columella appear too distinct, though the lines of growth show that
it must be rather distinctly truncated.

Locality and position: Same as preceding.

POLYPHEMOPSIS PERACUTA, M. and W.

Pl. 31, fig. Ta, 76.

Bulima? peracuta, Meex and Worruen, October, 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 466.

SuELL rather large, elongate-conical; spire much elevated,
attenuate, very acutely pointed at the apex. Whorls about
thirteen, nearly or quite flat, and increasing gradually in size ;
last one forming more than half the entire length, slightly

376 PALHONTOLOGY OF ILLINOIS.

prominent around the middle, somewhat extended below; suture
moderately distinct between the lower whorls, but scarcely
impressed above. Aperture rather narrow-subovate, acutely
angular above, narrow and apparently somewhat effuse below;
outer lip thin, sharp, and nearly straight; inner lip somewhat
reflexed below, and winding around the columella so as to pass
out of sight opposite the middle of the aperture; obsolete above;
columella arcuate and tortuous, curving outwards to connect
with the outer lip at the base of the aperture. Surface smooth,
but showing under a good lens extremely fine, very obscure
striz of growth. Length, 1.67 inches; breadth, 0.54 inch;
apical angle regular, divergence 22°. Length of aperture,
0.55 inch; breadth of ditto, 0.30 inch.

We have seen this beautiful species in collections labeled Loxonema Halli.
A single glance, however, at the figure and description of that species published
by Norwood and Pratten (Jour. Acad. Nat. Sci., Philad., vol. iii, p. 77, pl. 1x,
fig. 11), will be sufficient to satisfy any one that it is a clearly distinct species.
Norwood and Pratten represent their species as having the upper edge of the
whorls tumid, and separated by a deep suture; while all the volutions in our
shell are nearly or quite flat, with a very shallow suture between. It also has
three or four more whorls and a totally different formed aperture—that of L.
Halli being ‘‘three times as long as broad,” while in our species it is scarcely -
twice as long as wide. Our shell has likewise a much more arcuate columella,
while its body whorl is convex, instead of concave, around the middle.

We have not seen a specimen of this species with the lip entire at the base
of the aperture. In our figure 76 it was restored in outline below, but it is
there shaded in the engraving so as to give it a somewhat unnatural appearance.
As near as we can determine from the direction of the lines of growth, there is
not a truncation of the columella below, though we have not been able to see
exactly how it connects with the outer lip. In the figure, the engraver has
also carried the.inner lip too far up. It is not developed above the middle of
the aperture, where it passes around out of sight.

Locality and position: Near Urbana, St. Clair county, Illinois; Upper Coal
Measures. Also, near Springfield, in same position.

INVERTEBRATES. 377

Genus LOXONEMA, Phillips, 1841.

. (Paleozoic Fossils, p. 98.)

We doubt the propriety of referring such forms as we here range under
the name Loxonema, to the recent genus Zurbonilla, Risso (= Chemnitzia,
d’Orbigny), since they are generally not only much larger shells, but differ in
not having, so far as we have been able to see, the apex of the spire reversed,
as in the species upon which the genus Jurbonilla was founded. We therefore
agree with those who prefer to retain Phillips’s name, Loxonema, for these
older fossil species. It is, however, we think, generally made to include species
belonging to other allied, but distinct types: L.? compacta, L.? obtusa, ete., of
Hall (Paleontology of New York, vol. iii, pl. 54), for instance, belonging
apparently to Reemer’s genus Michelia.

LoxoNEMA ScITULA, M. and W.

Pl. 31, figs. 10a, 10, 10c.

Loxonema scitula, Marx and WortHEN, Octover, 1860. Proceedings Acad. Nat. Sci.,

Philad., p. 464.

SHELL small, elongate-conical; spire elevated and regularly
tapering; volutions eight to eight and a-half, very slightly
convex, increasing gradually in size, last one rounded and not
produced below; suture moderately well defined; aperture
obliquely ovate, acutely angular above and rounded below.
Surface ornamented by distinct, regularly disposed vertical
folds or costee, about fourteen of which occupy each turn; folds
equaling the depressions between, and on the last turn becoming
suddenly obsolete below the middle; no lines of growth visible.
Length, 0.23 inch; breadth, 0.10 inch; length of aperture,
0.07 inch; breadth of ditto, 0.04 inch. Apical angle regular,
divergence 27°.

Locality and position: Lower Coal Measures, Hodge’s creek, Macoupin Co.,
Illinois.*

* In first publishing this species, Springfield was by mistake given as the locality.

aS Szrr. 26, 1866.

378 PALEONTOLOGY OF ILLINOIS.

Loxonema ruGosA, M. and W.

Pl. 31, figs. lla, 118, lle.

Loxonema rugosa, Munx and Worrnemn, October, 1860. Proceedings Acad. Nat. Sci.,
Philad., p, 465.

SHELL small, elongate-conical; volutions seven and a half to.

eight, very slightly convex, increasing gradually in size, last
one rather abruptly rounded in the middle, not extended below;
suture moderately impressed; aperture obliquely ovate. Sur-
face of each whorl ornamented by about eighteen straight, dis-
tinct, rounded vertical folds or costa, which equal the depres-
sions between, and are disposed so as to range in regular lines

from the body whorl to the summit of the spire; those on the —

last whorl becoming abruptly obsolete below the middle. No
lines of growth visible. Length, 0.44 inch; breadth, 0.18
inch; length of aperture, 0.12 inch; breadth of do., 0.08 inch.
Apical angle convex, divergence 25°.

This shell is very nearly like the last, but differs in being less attenuate
towards the summit of the spire, and in having its coste arranged in regular
rows up the spire, while those of the last are usually arranged so as to alternate
on the different turns. Its cost are also proportionally a little smaller, and
somewhat more closely arranged. Notwithstanding these differences, however,
more careful comparisons of other specimens examined since we first published
a description of this form, lead us to suspect that it may possibly prove to be
only a variety of the last, though we have not been able to fully satisfy our-
selves that this is the case.

The lip of our specimen being broken, our figure does not show the form of
the aperture, which must have been more rounded than the specimen figured
would indicate.

Locality and position: Springfield, Ill.; Upper Coal Measures.
LoXoNEMA MULTICOosTATA, M. and W.

Pl. 31, fig. 12@, 126, 12¢.

SHELL small, conical; spire moderately elevated; volutions
about seven and a half, somewhat convex, increasing gradually

—s

«

INVERTEBRATES. 379

in size, last one forming about one-third the entire length,
rounded, but not much produced below; suture well defined ;
aperture oval subrhombic, slightly effuse on the inner~side
below; outer lip thin and nearly straight; inner lip a little reflex-
ed. Surface ornamented by small, regular, straight, vertical
folds or coste, about equaling the spaces between, and number-
ing near thirty on the body whorl. Costze obsolete on the under
side of the last turn; no lines of growth visible under a lens.
Length, 0.36 inch; breadth, 0.15 inch; apical angle nearly
regular, divergence about 28 °.

This species resembles the last two in its general appearance, but differs in
having more numerous, smaller, and more closely arranged costz. Its whorls
are also more convex, and its suture deeper. It is more nearly allied to Z.
scalaroidea (sp.) of Phillips, but differs from de Koninck’s figures of that spe-
cies, in having perfectly straight, instead of flexuous, coste. The number of
its costz is also less than in L. scalaroidea, and its spiral angle is greater than

given by de Koninck in his a ee (22°), though less than represented in
his figures (about 32°).

Locality and position: Macoupin county, Ill.; Coal Measures.

LoxXoNEMA CERITHIFORMIS, M. and W.
Pl. 31, fig. 13a, 136, 13¢.

Loxonema cerithiformis, Mex and Worruen, Oct., 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 465.

SHELL rather under medium size, elongate-conical; spire ele-
vated, gradually tapering to an acute point; volutions eleven
to twelve, convex, and increasing gradually in size; last one
not much enlarged, somewhat abruptly rounded below the
middle. Suture deep. Aperture oval subrhombic, a little
longer than wide, apparently provided with a small notch
or angularity at the base of the columella; outer lip thin,
rather distinctly sigmoid in outline; columella somewhat tor-
tuous. Surface nearly smooth, but showing under a lens very
fine, obscure lines of growth, which curve parallel to the mar-

380 . PALAONTOLOGY OF ILLINOIS.

gin of the lip; just below the suture these lines are gathered
into a series of minute, short, regularly arranged wrinkles or
‘crenulations, scarcely visible without the aid of a lens. Length,
0.70 inch; breadth, 0.24 inch; length of aperture, 0.18 inch;
breadth of do., 0.11 inch. Apical angle regular, divergence 24°.

In some respects this species is closely allied to Chemenitzia subconstricta,

de Koninck (Sup. An. Foss., pl. lviii, p. 17), particularly in form, and the
peculiar minutely wrinkled or crenulated character of the upper margin of its
whorls. It differs, however, in the form of the aperture, which is more quad-
rangular, and less produced below, than de Koninck’s species, and the columella
is also straighter. The lip of our specimen being broken, may give an unnatu-
ral appearance to the base of the aperture, but it certainly looks very much as
if there had been a small oblique notch at the end of the columella, as we see
in Cerithium. If this is natural it can scarcely be a true Loxonema.

Locality and position: Springfield, Ill.; Upper Coal Measures.

Genus ORTHONEMA, M. and W.
(Ltym.—op%oc, straight; vyya, a thread.)
Orthonema, Munk and WortHmEn, June, 1861. Proceed. Acad. Nat. Sci., Philad., p. 146.

SHELL elongate, many-whorled; volutions ornamented with
revolving carinse, crossed by nearly straight lines of growth;
body whorl generally angular, not much enlarged or produced
below; aperture angular above, slightly effuse below; peri-
stome incomplete; outer lip simple, nearly straight; axis im-
perforate.

The shell upon which we proposed to found this genus has much the appear-
ance of a Murchisonia, but differs in being entirely destitute of a spiral band, or

a sinus in the lip, as in that genus and Pleurotomaria—the lines of growth

being distinctly seen crossing the carinz, and the spaces between, without
making the slightest curve. In first indicating the typical species of this genus,
we referred it, with a query, to Mr. Salter’s genus Hunema; later comparisons,
however, have satisfied us that it cannot be properly placed in that group, since
it does not possess the peculiar sigmoid lip characterizing the forms described
by Mr. Salter. It also differs in having its whorls closely contiguous at all

a

‘INVERTEBRATES. 381

stages of growth, while its inner lip is less developed, and its columella is not
provided with a ridge or angle, as in the typical species of Hunema.

From the genus Jwurvitella, some species of which our shell resembles in form
and general appearance, it differs in its slightly effuse and less rounded aperture,
disconnected peristome and straight outer lip. It is probably more nearly allied
to Loxonema than to any of the groups we have mentioned, but presents the
_ well marked differences of being provided with distinct revolving carinze and a
straight instead of a sigmoid outer lip and lines of growth. It will probably
include several species of Turritella-like shells from the Coal Measures.

OrTHONEMA SALTERI, M. and W.

Pl. 31, fig. 14a, 14, 14c.

Hunema? Salieri, Menx and WortHen, October, 1860. Proceedings Acad. Nat. Sci,

Philad., p. 464.

SHELL small, elongate-conical, acutely pointed at the apex.
Volutions about thirteen, vertically flattened around the middle
and sloping obliquely to the suture above, increasing gradually
in size ; last one angular around middle, and a little convex, but
not much extended below; suture linear, rather well defined.
Aperture ovate, angular above, and rounded or slightly effuse on
the inner side below; outer lip thin, and nearly straight; inner
lip but slightly developed; columella arcuate. Surface orna-
mented by three rather distinct revolving lines or carine, two of
which occupy the upper margin of the whorls, while the third
is placed just above the suture, on the spire, but passes around
the middle of the last turn. Lines of growth small, rather
obscure, and nearly straight from the suture until they reach
the under side of the body whorl, where they arch a little for-
ward, and then curve backwards to the base of the columella.

A single revolving, impressed line is sometimes seen below the
angle, on the under side of the last turn. Length, 0.50 inch;
breadth, 0.17 inch. Length of aperture, 0.17 inch; breadth,
0.10 inch. Apical angle convex, divergence 23°.

Locality and position: Hodge’s creek, Macoupin county, Illinois; Lower
Coal Measures.

382 PALZONTOLOGY OF ILLINOIS.

Genus TURRITELLA, Lamarck, 1799.

(Prodr., p. 74.)

TURRITELLA? ? STEVENSANA, M. and W.
Pl. 217, fig. 8 and 8a.

SHELL very small, elongate, slender, and very gradually taper-
ing to a pointed apex; volutions ten to twelve, distinctly convex,
and rather rounded, increasing gradually in size, last one form-
ing about one-fourth the entire length—all very slightly flat-
tened just below the suture, the flattened space being narrow
and sloping outwards; suture well defined in consequence of
the convexity of the whorls. Surface ornamented by small,
prominent, thread-like, revolving lines or coste, separated by
impressed spaces about three times their own breadth; of these
costze, five or six may be counted on the body whorl, and four
or five on each of those of the spire. Crossing all the coste
and spaces between, there may also be seen, by the aid of a
magnifier, numerous minute, strongly sigmoid lines of growth.
Aperture unknown. Length, 0.27 inch; breadth, 0.09 inch;
apical angle very regular, divergence about 20°.

We only know this little shell from moulds left in the matrix, and our figures
were drawn from wax casts made in one of these moulds, which, however, are
so sharply defined as to show clearly the most minute surface markings. Judging
from the form of the last whorl, it is probable the aperture is nearly circular,
and the lines of growth indicate that the outer lip must be broadly retreating,
near or a little above the middle (without, however, haying any traces of a
defined sinus), and very prominent below. The moulds also show that the
under side of the last whorl is marked by small, rather crowded, revolving lines,
considerably less than those above, and indicate that the columella was probably
not perforated.

It is with great reluctance that we refer this little shell, even provisionally,
to the genus Turritellu, since we have good reasons for believing that that genus
was not introduced until long after the Carboniferous period. As it seems,
however, not to belong to any of the known paleozoic genera, and is more like

INVERTEBRATES. 383

the existing genus Jwrritella than any of the Mesozoic or other more modern
types, we have concluded to refer it, for the present, to that group, rather than
to propose for its reception a new genus, without being able to point out good
characters by which it can be distinguished from Turritella. Its lines of
growth curve much like those of Loxonema, from all the species of which, how-
ever, it differs in its revolving coste. At a first glance it might be mistaken
for a Murchisonia, but it certainly differs from that genus in having no trace of
a revolving band or labial sinus.

Prof. Swallow has described, from the Coal Measures at Lexington, Missouri
(St. Louis Acad. Sci.,1, p. 203), under the name Murchisonia minima, a very,
similar little shell, which may possibly be the same species, unless it really has
the sinus in the lip, and the spiral band, of Murchisonia, to which, however,
Prof. S. makes no allusion in his description. Dr. Stevens has also described
a somewhat similar shell, under the name Aciis minuta, from the Upper Coal
Measures at Danville, of this State (Am. Jour. Sci., (2), xxv, p. 259), but his
shell differs specifically in the number of its spiral costze.

Our specific name is given in honor of Dr. R. P. Stevens, of New York City.

Locality and position: North branch Saline creek, Gallatin county, [linois;
Upper Coal Measures.

Genus SOLENISCUS, M. and W., 1860.

(swiyvtcxos, a little channel or gutter.)
Soteniscus, Mpnx and WorrTHeEn, Oct., 1860. Proceed. Acad. Nat. Sci., Philad., p. 457.

SHELL fusiform; spire pointed; whorls nearly flat, last one
more or less convex in the middle, contracted and produced
below into a straight canal; surface smooth, or only marked
by very obscure lines of growth; aperture narrow; outer lip
thin and entire; columella straight, imperforate, and provided
with one sharply elevated, plait or fold.

The species constituting the type of this genus bears some analogy to the
genus Fasciolaria, but as it differs in having only one nearly transverse fold on
the columella, instead of two or three very oblique ones; while its surface is
entirely destitute of nodes, coste, or revolving markings, and its outer lip
smooth within, there is little reason for supposing it to be nearly related to
that group, which is unknown below the upper Cretaceous. Its texture,
smooth surface, pointed spire, shallow suture, and general physiognomy, would

384 PALEONTOLOGY OF ILLINOIS.

appear to indicate affinities to Macrochetlus and Polyphemopsis ; but the posses-
sion of a distinct canal, and straight columella, remove it widely from these
genera. Macrocheilus limnxiformis, of MeCoy, and M. elongatus, of Phillips,
should doubtless be ranged in the same group with our shell.

SOLENISCUS TyPicus, M. and W.
Pl. 31, figs. 15a, 15d.

Soleniscus typicus, Munk and WortTHEN, October, 1860. Proceed. Acad: Nat. Sci.,
Philad:, p. 467.

SHELL fusiform; spire rather elevated, and acutely conical ;
volutions seven to seven and a half, flat or but slightly convex,
increasing rather rapidly in size, last one forming more than
three-fourths the entire length, somewhat ventricose in the
middle, and contracting rather gradually into the straight
canal below; suture somewhat shallow ; aperture very narrow,
or lanceolate, acutely angular above, and narrowing gradually
into the canal below; outer lip sharp; fold of the columella
located a little below the middle of the aperture. Surface
smooth or only showing very obscure traces of lines of growth.
Length, 0.73 inch; breadth, 0.30 inch; apical angle slightly
concave, divergence 40°. Length of aperture and canal, about
0.34 inch; breadth of former, 0.11 inch.

This interesting shell is more nearly like Macrocheilus limnzxiformis, McOoy
(Brit. Palzxozoic Fossils, pl. 3, i, fig. 40), than any other species with which we
are acquainted, but is smaller, and much less ventricose around the middle of
the body whorl. The resemblance is so striking, however, that we have little
hesitation in referring Prof. McOoy’s species to our genus.

Locality and position : Upper Coal Measures, Springfield, Illinois.

a

INVERTEBRATES. 385

Genus BELLEROPHON, Montfort, 1808.

(Conch. Syst., i, p. 50.) .

BELLEROPHON CRASSUS, M. and W..
Pl. 31, fig. 16a, 16.

Bellerophon crassus, Merk and WortHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 458.

SHELL large, very thick, subglobose, or a little longer than
wide; volutions expanding moderately, rounded over the dor-
sum and sides; umbilical region somewhat excavated; mesial
band narrow, rather prominent, and subangular; aperture
transverse, reniform or sublunate; lip strongly thickened near
the umbilical excavations on each side, but not covering them,
thinner and moderately prominent in outline on each side of
the narrow sinus in the outer margin, and spreading in the form
of a rather thick, smooth callous, over the inner whorls, and
between the callosites on each side; surface marked by rather
distinct strie of growth, and irregular, transverse wrinkles,
which latter are strongest in the umbilical region and near the
aperture ; lines of growth and wrinkles making a very gentle
forward curve in crossing from the umbilicus to the dorsal band.
Greatest length, 2.26 inches; breadth, 2 inches; ditto of aper-
ture, 1.70 inches; breadth of mesial band near the aperture,
about 0.12 inch.

This fine Bellerophon resembles, somewhat, B. costatus, Sowerby, as figured
by de Koninck (Ann. Foss., pl. xxvi, fig. 2), but differs in having its aperture
less expanded, its umbilicus more exposed, and its surface not near so regularly
and distinctly costated. Its marks of growth are also much less arched back-
wards as they approach the mesial band, thus indicating a much smaller sinus
in the lip. Our specimen is somewhat weathered, but its marks of growth
appear never to have been near so strongly defined on the mesial band, as rep-
resented by de Koninck’s figures of B. costatus.

It has more nearly the form of de Koninck’s figures of B. vasulites, Montfort,
but differs in not being regularly costate, and in having the callosites of its lip
less developed in the umbilical region.

Locality and position: Pittsburg, St. Clair county, Ill.; Lower Coal Measures.

9 Sarr, 28, 1866,

386 PALAONTOLOGY OF ILLINOIS.

CEPHALOPODA.
Genus NAUTILUS, Linneeus, 1758.

(Syst. Nat. Ed., 10, t. 1, p. 709.)

NAUTILUS PLANORBIFORMIS, M. and W.
Pl. 29, fig. 4a, 46, 4c.

Nautilus (Discus) planorbiformis, Menx and WorTHEN, Oct., 1860. Proceed. Acad. Nat.
Sci., Philad., p. 469.

SHELL of medium size, compressed-discoidal ; umbilicus very
wide, shallow, and showing nearly all of each inner whorl.
Volutions about four, increasing gradually in size, very slightly
embracing, nearly rounded in young shells, but becoming a
little compressed on the sides and dorsum in mature individu-
als; having a row of obscure nodes around each dorso-lateral
margin. Aperture slightly oval, its longer diameter being in
the plane of the shell. Septa deeply concave; their margins
arching gently backwards on the sides and dorsum, and sepa-
rated by spaces less than one-third the transverse diameter of
the whorls; siphuncle small and central; surface apparently
smooth. Length or greatest diameter, 3.74 inches; height, 3.10
inches; breadth, about 1 inch.

This and the following species, together with such forms as LV. occidentalis
of Swallow, should probably constitute another subgenus distinct from Dis-
cites and Trematodiscus (see p.161). We are rather inclined to doubt, how-
ever, the propriety of retaining either of these groups in the genus Nautilus,
as founded upon widely different recent shells,

Locality and position: Alpine, Iowa; Coal Measures.

NAUTILUS SANGAMONENSIS, M. and W.
* Pil. 29, figs. 3, 3a, 3b.

Nautilus (Discus) sangamonensis, Merk and WorTHEN, Oct., 1860. Proceed. Acad. Nat,
Sci., Philad., p. 470.
Compare Discites tuberculatus, OwEN, 1852. Geol. Report Wisconsin, lowa and Min-
nesota, p. 581, tab. v, fig. 14; (not Mautilus tuberculatus, Sowerby, 1821).
Or this species we have seen but a single specimen, consist-

ing of about half of one volution. It is a little wider trans-

INVERTEBRATES. 387

versely than from the dorsal to the ventral side, and increases
rather gradually in size, from the smaller to the larger end,
being evidently part of a discoid shell, with an umbilicus about
equaling the transverse diameter of the outer whorl. On the
dorsum it: is nearly flat, or but slightly convex, and the sides
are a little concave with an outward slope, the greatest con-
vexity of the whorls being at the margin of the umbilicus. The
ventro-lateral margins are obliquely flattened so as to form an
abrupt slope into the umbilicus, leaving a subangular promi-
nence around the margin of the umbilicus. The ventral side
is moderately concave along the middle, for the reception of
the inner whorls, each of which is probably about ong-third
hidden. On each dorso-lateral angle there is a series of rather
low nodes, about twenty-three to twenty-four of which proba-
bly existed on each entire whorl.

A transverse section of the whorls is nearly quadrangular
in outline, if we regard the small ventral concavity, and the
two sloping ventro-lateral margins together as one side. The
septa are moderately concave, and arch gracefully backwards
on each side, and in the ventral depression; while they make
a less distinct curve in the same direction in crossing the
periphery or outer side. The siphuncle is small, and located a
little nearer the outer than the inner side of the whorls.
Aperture and surface markings unknown. Length, or greatest
diameter, as inferred from the curve, about 2 inches; height,
about 1.45 inches; breadth near the aperture, 0.88 inch.

This species bears some relations to J. occidentalis, Swallow, 1858(=—N.
quadrangulus, McChesney, 1860), but has more slender whorls, and its dorsum
differs in being moderately convex and smooth along the middle, instead of con-
cave and provided with two rows of nodes. Its dorso-lateral nodes are likewise
less prominent, and its ventro-lateral angles differ in being destitute of any
traces of nodes. The whorls of our shell are also more deeply embracing than
those of the species described by Prof. Swallow. The form published by Prof.
McChesney under the name of V. nodocarinatus, is also only a variety of the

NV. occidentalis.
Our shell is more nearly like a form referred by Murchison, de Verneuil and

>

388 PALAONTOLOGY OF ILLINOIS.

Keyserling, to VV. tuberculatus, Sowerby, in their Geol. Russ. and Ural Mount.,
vol. ii, pl. xxv, fig. 12 a, b, but differs in having its sides flattened and sloping
outwards from the prominent margins of its umbilicus, instead of inwards from
the outer angles; while the nodes of its outer angles are more numerous and
more crowded. According to Sowerby’s and Phillips’s figures of NV. tubercu-
latus, the node-bearing angles are situated near the middle of each side, from
which points the whorls round abruptly into the umbilicus, without any inter-
mediate flattening of the sides. Hence our shell must differ more widely from
the form upon which NV. tuberewatus was founded, than from the Russian form
alluded to. Prof. McCoy also describes WV. tuberculatus as having the ‘“siphun-
cle very large, central,” while in our shell it is small and placed a little outside
of the centre.

The shell figured by Dr. Owen as Discites tuberculatus, Owen, (Report Geolo-
gical Survey Wisconsin, Iowa and Minnesota, tab. v, fiig. 14), is possibly iden-
tical with our species, but as Sowerby had used the same name for an allied
species of this group, we cannot retain it for this shell.

Locality and position: Upper Coal Measures, Sangamon county, Illinois. -

Genus CYRTOCERAS, Goldfuss, 1832.

(Dech. in de la Beche, p. 536.)

CYRTOCERAS (APLOCERAS) cuRTUM, M. and W.
Pl. 30, figs. la, 18, le.

Cyrtoceras curtum, MrEK and WortTHEN, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 468.

SHELL having the form of a short, moderately compressed,
rapidly tapering, and slightly curved cone; section subcircular
a little below the middle, but transversely oval above,—the
dorsal and ventral sides being compressed, convex, and the
lateral margins somewhat flattened. Surface ornamented by
numerous, regularly arranged, annular strize, or impressed lines,
which arch a little forward in crossing the dorsum, where they
are separated by spaces several times their own breadth,
excepting near the smaller extremity of the shell. On the
lateral and ventral sides these strize become much more crowded,
and more deeply impressed. Septa rather deeply concave ;
siphuncle small, and placed about half way between the middle
and the dorsal side. Length of a specimen imperfect at the

x

a =

INVERTEBRATES. 389

smaller end, 1.25 inches; greater diameter at the aperture,
about 1.24 inches; smaller ditto, 0.92 inch; greater diameter at
the smaller end, 0.54 inch; smaller ditto, 0.43 inch.

This species has somewhat the form and general appearance of C. depressum,
Goldfuss, but is less compressed, and differs in being a little flattened on the
sides; while its siphuncle is smaller, and not so near the dorsal margin. As
near as can be determined by the direction of the lines of growth on our shell,
it would also seem to differ in having the lip more prominent on the dorsal side.
It isa very remarkable, rapidly expanding form, that may possibly belong to
an undescribed genus.

Locality and position: Grayville, Illinois; Upper Coal Measures.

CYRTOCERAS? DILATATUM, M. and W.

Pl. 29, fig. 2.

Cyrtoceras 2? dilatatum, Mrnx and WortuHeEn, October, 1860. Proceed. Acad. Nat. Sci.,

Philad., p. 468.

SHELL broadly conical, very rapidly expanding, rather thick
especially on the ventral side, slightly curved and apparently
somewhat compressed on the dorsal and ventral sides. Surface
ornamented by numerous, distinct, regularly arranged, subim-
bricating, annular marks of growth. Septa at about two inches
from_the smaller end, separated by spaces equaling near one-
twelfth of the greater diameter of the shell at the same place.
Siphuncle and form of the aperture unknown. Length of an
entirely septate specimen, incomplete at both extremeties, 3.50
inches; breadth at the larger end, about 3 inches.

It is possible this may be a larger distorted specimen of the same species as
the last, but with the specimens we have yet had for comparison, we cannot do
otherwise than regard them as distinct. The form now under consideration
differs from C. curtum, so far as we have been able to determine, in not being
flattened on each side, and in having its lines of growth passing straighter
around, instead of deflected downwards on the sides. Like the last, it can only

be referred provisionally to the genus Cyrtoceras, from the typical species of
which it differs materially in form.

Locality and position: Springfield, Illinois; Upper Coal Measures.

390 PALHONTOLOGY OF ILLINOIS.

Genus GONIATITES, de Haan, 1825. (See p. 165.)

GONIATITES GLOBULOSUS M. and W.

Pl. 30, fig. 2a, 26, 2c, and accompanying cuts.

Goniatites globulosus, Munk and WortTHEN, Oct., 1860. Proceedings Acad. Nat. Sci.,
Philad., p. 471.

Fig. 38.

Goniatites globulosus.
Cut showing the outline and septa of a very large specimen from Eastern Kansas, Natural size,

INVERTEBRATES. 391

Big, 89. SHELL attaining a large size, length and
breadth often nearly equal; very broadly
rounded over the dorsum; umbilicus deep,
less than half as wide as the transverse di-
ameter of the outer whorl; volutions more
than three times as wide transversely as
the diameter from the dorsal to the ventral

cain side, subangular around the margin of the
Outline of the typical speci- umbilicus. Aperture lunate, breadth about

men, natural size, to show

fon of thespertureas determin three and a half times the dorso-ventral
diameter. Surface of internal casts sometimes slightly con-
stricted at intervals, as if from an occasional thickening of the
inner lip. Septa moderately distant; dorsal lobe nearly as
wide as long, and deeply divided into two slightly diverging,
simple, lanceolate branches; dorsal saddle linguiform, being
regularly rounded at the end, and a little narrower than the
dorsal lobe, but equaling it in length, and slightly contracted
in the middle; superior lateral lobe as long as the dorsal sad-
dle, but narrower, and pointed at the extremity ; lateral saddle
a little broader than the dorsal saddle, which it resembles in
other respects, excepting in being shorter on the ventral side ;
inferior lateral lobe very short, but with a pointed apex—not
visible when the umbilicus is filled. Surface unknown. Length
or greatest diameter, of the typical specimen, 1.18 inches;
height, 1 inch; breadth near the aperture, about 1.18 inches.

Prof. Cox has figured in the Kentucky Report, vol. iii, pl. x, fig. 1, a shell
which seems to be related to this, but from the measurements given by
him it is manifest that the form he has figured is more compressed, and has
a proportionally smaller umbilicus, while his diagram of a septum shows a
more deeply divided dorsal lobe, with less spreading divisions. He also repre-
sents the sinus of the dorsal lobe as being pointed instead of obscurely bifid, as
in our species, and the dorsal saddle pointed instead of rounded at the extremity.
Our shell likewise differs in having a proportionally smaller superior lateral
lobe.*

* In making comparisons with Prof. Cox’s description and diagram, it is necessary,
in order to understand him clearly, that the reader should bear in mind that he has

392 PALEONTOLOGY OF ILLINOIS.

G. sphxricus, Martin, agrees more nearly in form with our shell, but has a
much smaller umbilicus, while its septa are entirely different. The septa of
G. diadema, of Goldfuss, are very similar to those of our species, but that
species has also a smaller umbilicus, and is much less ventricose than ours.

For the use of the very fine specimen from which our large outline cut No.
38 was made, we are indebted to Prof. EH. Daniels. It is much larger than the
typital specimens found in this State, and has the whorls a little less angular
on each side, though we believe it belongs to the same species. Prof. Daniels
obtained it from a clergyman in Kansas, who could give no information in
regard to the locality from which it was obtained, beyond the fact that it was
found in Kastern Kansas. It shows faint traces of obscure nodes on the obtuse
lateral angles of the whorls.

Although our figures on plate 30 show apparently the average size of this
species at the Springfield locality, we have before us a fragment from there,
indicating a size of nearly half that of the Kansas specimen.

Locality and position: Upper Coal Measures, Springfield, Illinois. Also
Eastern Kansas.

GONIATITES I0OWENSIS, M. and W.
Pl. 30, fig. 3a, 36, 3c.

Goniatites cowensis, Merk and WortueEn, October, 1860. Proceed. Acad. Nat. Sci.,
Philad., p. 471.

SHELL attaining a rather large size, discoidal or nearly flat
on the sides, and narrowly rounded on the dorsum. Umbili-
cus rather shallow, about one-half as wide as the breadth of
the outer whorl from the ventral to the dorsal side, showing
apparently about one-third of each inner whorl. Volutions
increasing gradually in size, but slightly convex on the sides,
nearly twice as broad from the ventral to the dorsal side, as
the transverse diameter, and profoundly grooved within for the
reception of the inner whorls; aperture, as near as can be
determined from a section of the whorls, narrow-subovate,
deeply sinuous on the ventral side. (Surface unknown.)

reversed the usual mode of describing the sinuosities of the septa. That is to say, he
has described the lobes as sinuses, and the sinuses or saddles as lobes.

—————————

— ee

=

ee ee ee

.
—- ee ee ee ee eee eee

4

INVERTEBRATES. 393

Septa rather crowded and deeply sinuous; dorsal lobe large,
considerably wider than long, profoundly divided into two
large lanceolate branches, each of which has an acutely pointed
extremity ; dorsal saddle linguiform, slightly oblique, a little
larger than the divisions of the dorsal lobe, and longer than
wide; superior lateral lobe conical or short lanceolate, as long
as the dorsal saddle, but not more than half as wide, and
acutely pointed at the apex; lateral saddle a little shorter than
the dorsal saddle, but narrower at the extremity; inferior
lateral lobe rather shorter than the superior, particularly on
the ventral side, but resembling it in other respects; ventral
saddle shorter than the others, and broadly rounded.

So far as we have been able to compare this fine species with figures and
descriptions of those described from foreign localities, or from American rocks,
it seems not to be very closely allied to any other form with which we are
acquainted. It evidently attains a large size, the specimen figured by us con-
sisting entirely of septate whorls. Length, or greatest diameter, about 4.20
inches; height, about 3.42 inches; breadth or convexity near the aperture, a
little over 1 inch.

Should it be ascertained that the type of Montfort’s proposed genus Aga-
nides, was a true Goniatite, then the names of this and preceding species would
become Aganides globulosus and A. iowensis.

Locality and position: Alpine, Iowa; Coal Measures.

AW TLC Ul AT As

CRUSTACEA.
ENTOMOSTRACA.
XIPHOSURA.

Genus BELLINURUS, Keenig.

(Icones Sectiles, 18—, iii, p. 230.)

Nor having had an opportunity to consult Koenig’s original diagnosis of this
genus, nor indeed a good description of it by any other author, we are not
—50 Oor, 1, 1866.

394 PALHONTOLOGY OF ILLINOIS.

aware what characters were assigned it, or how its author proposed to distin-
guish it from the existing genus Limulus. Most authors, including Milne
Edwards, Bronn, Prestwich, Mantell, Portlock, Murchison and others, referred
the species to Limulus, though Portlock, in doing so, remarks that the distinct
trilobation and segmentation of the abdomen in these fossil species, seem to
constitute a generic distinction. Pictet admits the genus in his TJraite de
Palzxont., ii, 538, and remarks that it is distinguished from Limulus “by the
articulation of the tail, and above all by the abdominal buckler presenting two
distinct longitudinal furrows.” Prof. Owen also admits the genus in his valua-
ble Palzeontology, or Systematic Summary of Extinct Animals, p. 43, and says
it differs from the “ King-Crab (Zimulus) in the movable condition of the body
segments.”

A careful study, however, of fine specimens of the species described below,
has satisfied us that the segments of its abdomen are not movable, but as firmly
and completely united into a single shield as in the genus Limulus. We are,
therefore, led to believe that this genus is mainly distinguished from Limulus
(so far as its characters have yet been made out) by the more transverse form
of its cephalo-thoracic shield, its proportionally much longer and more slender
legs,* the transverse or subcircular form and distinct trilobation and segmenta-
tion (not complete division, however) of its abdomen, as well as by its flattened
borders without movable spines. There are also some differences in the more
anterior position of the eyes, the stronger and more continuous character of the
ocular ridges, as well asin the subdivisions of the area included by these
ridges in Bellinurus. Other differences, of perhaps greater importance, will
probably be observed, when the appendages of the under side can be seen.

None of our specimens are in a condition to show the small anterior pair of
simple eyes, though from the general analogy of this interesting crustacean to
the genus Limulus, it is more than probable better specimens may show them.
And yet it is possible, from the anterior position of the eyes, corresponding to
the larger reticulated pair in the genus Limulus, that the small supplementary
pair may not have been needed. As in Limulus, it shows a row of six small
pits in each of the longitudinal furrows of the abdomen, marking the position
of the muscular apophyses within; while the condyle, for the articulation of the
abdomen with the cephalo-thorax, seems to agree exactly with that of Limulus.
We are not aware of the nature of the peculiarities in the articulation of the

*One of our specimens of the following described species, (as well as one of B. anthraz,
figured by Prestwich, Trans. Geol. Soc., London, v, p. xli, fig. 1), shows that at least
one pair of the legs (or possibly the antennz) must have been quite as long as the
abdominal and cephalo-thoracic shields together; which would be proportionally more
than twice the length of any of the legs or antenne in Limulus.

INVERTEBRATES. 395

caudal segment mentioned by Pictet, none of our specimens being in a condi-
tion to show the connection of that appendage with the abdomen satisfactorily,
while he does not explain in what the difference consists.

Betuinurus Dana, M. and W.
Pl. 32, fig. 2, 2a.

Bellinurus Danz, Mzex and Wortuen, March, 1865. Proceedings Acad. Nat. Sci.,

Philad., p. 43.

CEPHALO-THORACIC shield transversely crescentric, more than
twice as wide as long, moderately convex, the height nearly
equaling half its length ; anterior and antero-latera: margins
broadly and regularly rounded; lateral angles produced obliquely
backwards and outwards, with a very slight inward curve,
into slender mucronate spines, terminating remote from, and
nearly opposite the middle of the abdomen; posterior margin
on each side for about two-thirds of the way in from the lateral
angles, toward the middle, concave in outline; nearly straight
or very slightly concave along the middle between these points.
Mesial lobe small, somewhat lower than the ocular ridge on
either side, but rounded and well defined behind, where it
supports a small central tubercle (or short spine?), thence nar-
rowing forward, and sometimes showing a slight tendency to
develop a second much smaller tubercle, at about one-third
the length of the shield from its posterior margin—near
which point it suddenly contracts into a mere linear carina,
that extends forward to the anterior transverse division of the
ocular ridge. Area included by the ocular ridge, crown-
shaped or subquadrangular in outline, and composing the cen-
tral third of the cephalo-thoracic shield; a little wider anteri-
orly than its length, which equals about five-sixths that of the
shield; lateral margins concave in outline; anterior side con-
vex, with a central emargination; internal surface divided into
four irregular subordinate areas, by the mesial lobe with its

396 PALEONTOLOGY OF ILLINOIS.

linear anterior continuation, and a less distinctly defined,
secondary transverse linear ridge. Ocular ridge narrow, but
distinct, its lateral divisions arching inwards behind the eyes,
and terminating posteriorly at the margin of the shield, nearly
opposite the middle of each lateral lobe of the abdomen, in a
(triangular) spine? which is directed backwards, outwards, and
a little upwards; anterior transverse division arching forwards
on each side, and curving backwards in the middle. Com-
pound eyes small, remote and located one at each antero-late-
ral angle of the crown-shaped central area, at points about one-
third the length of the shield from its anterior margin. Sim-
eyes, if they existed, unknown.

Abdomen transversely suboval, being wider than long, and
nearly straight anteriorly, with lateral margins, rounding in
abruptly in front, and more gradually into the regularly
rounded posterior outline; generally rather more depressed
than the cephalo-thorax, particularly in front. Flattened late-
ral border rather narrow, and regularly scolloped between its
projecting marginal spines. Mesial lobe narrow, or of about
the same breadth as that of the cephalo-thorax, and near half
as broad as, and a little more elevated than, the lateral lobes;
segments well defined; first and third each provided with a
small central tubercle; sixth as long as any three of the others,
rather abruptly narrowed and depressed behind, and _sur-
mounted anteriorly by a large tubercle (or spine?). Lateral
lobes somewhat flattened on the inner half, and rounding down
rather abruptly to the flattened free borders on each side and
behind; segments defined by distinct linear ridges, which are
separated by flattened spaces four or five times as wide; these
ridges extend obliquely outwards and a little backwards across
the lateral lobes and their flattened borders, beyond which
they are produced into slender mucronate spines, of nearly
equal length, curved obliquely backwards.

Telson apparently nearly two-thirds as long as the abdomen,

INVERTEBRATES. 397

gradually tapering, and trigonal or subtrigonal, being flat below,
angular on each side, and angular or rounded above. *

Appendages of the under side unknown, excepting one of
the legs, which is seen in one specimen, projecting out from
under the cephalo-thoracic shield, between its posterior margin
and the abdomen. It is slender, and shows of the first seg-
ment proje€®ting from under the shield, a length of about 0.12
inch. The next segment appears to be 0.25 inch in length,
with a breadth of only 0.04 inch. The succeeding segment
can be traced in the matrix for a distance of about 0.30 inch,
being slightly curved near the extremity, and apparently
tapering to a point, but the specimen is not in a condition
to show its termination. It is not possible to determine which
one of the legs this is. Entire length, from the extremity of
the caudal segment to the anterior margin of the cephalo-tho-
rax, about 1.90 inches. Length of cephalo-thorax, 0.57 inch;
breadth of do. to the extremities of postero-lateral spines, 1.70
inches; length of area included within the ocular ridge, 0.50
inch; greatest breadth “of do. (which is the distance between
the eyes), 0.60 inch. Length of abdomen, 0.65 inch; breadth
of do., exclusive of the flattened margin, 0.94 inch, including
it, 1.06 inches; breadth of mesial lobe, 0.23 inch; length of
caudal segment, about 0.60 inch.

Of the known species of Bellinurus, ours seems to be most nearly related to
B. bellulus, Koenig (the type of the genus, if we mistake not), which is
regarded as being identical with Limulus rotundatus, of Prestwich, (Zrans.
Geol. Soc., London, v. p. 491, pl. xli, figs. 4, 6 and 7.) From this species,
however, it may be at once distinguished by having the lateral angles of its
cephalo-thorax produced into long, slender spines, and the flattened border of

its abdomen proportionally much narrower, and armed with a series of sharp-
curved spines, instead of being merely serrated.

We should also remark here, that Prof. Owen’s figure of B. bellulus (Palz-
ontology, p. 42), as well as that given by Murchison of the same, under Prest-
wich’s name rotundatus ( Siluria, p. 281), represent the eyes as being located

at the lateral extremities of a large, transversely oval or subelliptical area;
while within this there is a smaller, crown-shaped area, defined by a

398 PALZONTOLOGY OF ILLINOIS.

ridge, and in all its principal features corresponding to that which in our spe-
cies has the eyes located at its anterior lateral angles. This wide difference in
the position of the eyes, as well as in the ridges of the central region of the
cephalo-thoracic shield, if they really exist, would apparently be of more than
specific importance. The close general agreement, however, of these forms, in
all their other essential characters, renders it very improbable that they belong.
to different genera. Hence, we would suggest that there may have been some
error in the figures cited above, representing the eyes (which ar@with difficulty
seén in any but well preserved specimens) in this outer position, and the pre-
sence of a large outer ocular area surrounding that corresponding to the quad-
rangular one in our species. Weare the more inclined to think this is the
ease, from the fact that Owen’s and Murchison’s figures appear to have been
reduced from Prestwich’s figures 5 and 6, cited above, which represent the two
halves of a nodule, containing a specimen and its mould, of B. bellulus, with a
large transversely oval space in the central region of the cephalo-thorax, as we
must think, accidentally crushed in. This view seems to be sustained, too, by
Mantell’s figures of the same species, from specimens collected by him at the
same locality (see Medals of Creation, p. 550), which show no traces of this
outer transversely oval ocular area.

In the elongated, spine-like character of the lateral angles of its cephalo-
thoracic shield, as well as in having the margins of the abdomen armed with
sharp spines, our species agrees more nearly with B. anthrax(= Limulus an-
thrax, Prestwich), but it differs in the form of the outline of the anterior side
of the cephalo-thorax, as well as in the direction of its prolonged lateral angles,
and its less produced spines around the flattened margins of the abdomen.
Hence, it appears to be intermediate in its characters between B. anthrax and
B. bellulus.

This fine species, the first of the genus discovered in America, was with
great pleasure dedicated by us to Prof. James D. Dana, the author of one of
the most important works on the Crustacea ever published; to whom we are
indebted for the loan of one of the specimens from which the foregoing descrip-
tion was drawn up.

Locality and position: Morris, Grundy county, Illinois; near the base of the
Coal Measures.*
es are a a eee eee
* By an oversight, the position of the Batrachian described from this bed, on p. 135,
is wrongly given, in a note at the bottom of that page, as above the middle of the Coal
Measures.

INVERTEBRATES. 399

TETRADECAPODA.
ISOPODA.
(ANISOPODA.)

Genus ACANTHOTELSON, M. and W.

Acanthotelson, Munk and WorrtHEN, October, 1860. Proceed. Acad. Nat. Sci., Philad.,
p. 457.

SUPERIOR antenne nearly as long as the inferior, and provided
with well developed accessory appendages; flagella of both
pairs longer than the peduncles; head about equaling the
length of the first two anterior thoracic segments. Thoracic
and abdominal segments (excepting the last one) not differing
materially in length, and each shorter than the head. Ante-
rior thoracic legs longer than the others, not chelate?. Telson
or terminal segment simple, long, spine-like, and laterally com-
pressed. Stylets with second segments (double?) much longer
than the first, and similar to the telson.

The fact that the oral apparatus, and other appendages of the head, as well
as the branchiz, always so important in the classification of the Crustacea, are
so rarely preserved in fossil species, especially those of smaller sizes, renders
their study more difficult than that ef most organic remains. Hence, in descri-
bing new species, genera, or other groups, the palzontologist is often unable to
give any information in regard to the very parts that would be the first to claim
the attention of the Carcinologist in the investigation of recent species.
Another difficulty also arises from the fact that, as in other departments of
palzontology, it often happens in the study of fossil crustacea, that we meet with
types presenting a combination of characters which in existing species are dis-
tributed in widely distinct groups. So that on finding a new type showing only
a part of its characters, we would often be led at once to place it in a group
with which probably the next specimen found would show it to possess some
one or more wholly incompatible peculiarities.

On first examining specimens of the typical species of the genus above
described, our impression was, that it must be, beyond all doubt, a true Amphi-
pod. A more careful examination, however, soon showed that it presents

.
400 PALEONTOLOGY OF ILLINOIS.

the radical difference from all the known types of that extensive group, of
having only one pair of the abdominal appendages, styliform, and the other
five natatory, instead of three pairs styliform and three natatory; thus combin-
ing with its Amphidodan abdomen, thorax, head, anterior appendages, and
general physiognomy, the single pair of styliform appendages of the Jsopoda.

Being therefore left in doubt in regard to its affinities, we sent sketches of
some of the best specimens to Prof. Dana, who had also previously received
some imperfect specimens of the same species from Illinois. On examining
these sketches and specimens, Prof. Dana wrote that he thinks this crustacean
most probably belongs to a group holding an intermediate position between the
typical Jsopoda and the Amphipoda, for which he has proposed the name Aniso-
poda. This intermediate group, as first shown by Prof. Dana, is characterized
like the Amphipoda, by having the three posterior pairs of thoracic legs in one
series, and the four anterior in another; while, as im the Jsopoda, the branchiz
are abdominal, and only one pair of abdominal appendages are styliform, and
five branchial. ;

In regard to the division of the thoracic legs into two series, we would
remark, that we have observed no evidence of it in all the specimens we have
seen, excepting one of those kindly loaned us by Prof. Dana. In this, however,
four pairs of these legs seem to be directed backwards, and only three forward;
which, if not produced by accidental distortion, would indicate Jsopod affinities.
Yet, in all the other specimens seen, the whole seven pairs are directed forward.
Although much inclined to believe the latter their normal arrangement, it
should be remembered, as suggested by Prof. Dana, that however important
this character may be in the study of the recent Tetradecapod crustacea, it can
scarcely be made available in the investigation of crushed fossil species, where
so many accidents might have occurred to place the legs in an unnatural
posture.

We have not been able to clearly satisfy ourselves whether or not our crusta-
cean had squamiformly developed epimerals, as in the normal groups of
Amphipoda ; though some of the specimens appear to show indications of such
development; while the shortening of the vertical diameter of the thoracic
segments, as compared with those of the abdomen, would seem to be, as it were,
an arrangement to make room for such scale-like epimerals. In addition to
this, the fact that all of the six or eight specimens we have yet seen, lie in the
concretions upon one side or the other, would appear to indicate that the lateral
motion of the thoracic legs was in some way restrained so as to prevent the
animal from taking an erect posture, which is precisely the effect produced in
the normal Amphipoda by the possession of well developed squamose epimerals.
If this should prove to be the case, it would show that the remarkable combi-
nation of Amphipod and Isopod, or Anisopod characters, already alluded to in

INVERTEBRATES. 401

this fossil, are real, and not simulative; since it would thus present mainly the
anterior structure (possibly even to the thoracic position of the branchie) of a
normal Amphipod, combined with the single pair of styliform, and five natatory
abdominal appendages of the Jsopoda or Anisopoda.

It must be evident, we think, that such an ensemble of characters as that
presented by our fossil, would exclude it from any known family of the Tetra-
decapoda; hence we can but regard it as the type of a new family, Acanthotel-
sonidzx.

ACANTHOTELSON Stimpsoni, M. and W.

Pl. 32, fig. 6, 6a to 6f.

Acanthotelson Stimpson, Mpnx and WorrueEn, March, 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 47.

LinEAR or sublinear in form. Upper antenne at least as long
as the head and first five thoracic segments; peduncle moder-
ately stout, rather longer than the head; first joint a little
longer and wider than the two others, which are of nearly
equal length; flagellum slender and very minutely jointed ;
accessory appendage nearly or quite as long as the flagellum,
and like it, minutely jointed. Inferior antenne as long as the
head and seven thoracic segments; peduncle slightly longer,
but otherwise similar to that of the upper antennze; flagellum
a little stouter and longer, but in other respects as in the upper
pair. Head, as seen in the (compressed) side view, subquad-
rangular, longer on the upper than the lower side, in conse-
quence of the obliquity of the anterior side; eyes small, round,
placed just below the bases of the upper antennz. The (four-
teen) thoracic and abdominal segments distinct, and (excepting
the last one) of nearly equal length—a few of those nearest
the head being a little shorter than the others; all diminishing
in depth (side view) from about the antepenultimate one for-
ward ; their anterior basal margins rounded ; posterior rectan-
cular or a little rounded.

== Fil Oor. 3, 1866.

402 PALEONTOLOGY OF ILLINOIS.

First pair of thoracic legs about one-fourth longer and a
little stouter than the succeeding five pairs, and apparently
terminating in a slender, sharp dactylus; first joint above a
little shorter, narrower, and more tapering than the next—
neither more enlarged than the others above. Five suc-
ceeding pairs of legs of nearly equal size and form; their
upper two (or three?) segments very short, and not enlarged ;
seventh pair nearly as long as the first, and more slender
than the others. Natatory abdominal appendages long and
slender; styliform pair with first segment short and quadrangu-
lar ; second and only other joint (double?) with each branch
(if there are two) simple, equal and as long as the telson,
which they nearly exactly resemble in form; their upper and
lower margins each with a row of short, oblique, rather distant
setae, between which may be seen, by the aid of a magnifier, a
series of much more minute, closely-arranged setze. Telson as
long as the last four abdominal segments; at its base one-half
as wide vertically as the penultimate abdominal segment ;
thence tapering, at first rapidly and then very gradually, to a
mucronate point—upper and lower margins setigerous, like
those of the stylets.

It is possible that when we can have an opportunity to examine additional
specimens, we may have to modify some of the characters given in the forego-
ing generic or specific description; though not, we believe, in any very essential
particular. We hope, however, to be able hereafter to add other characters,
and to clear up several doubtful points in the structure of this interesting type,
when we can have better specimens for study.

Length from anterior side of head to the extremity of the penultimate abdo-
minal segment, 1.30 inches; length of telson, 0.31 inch; length of the first six
abdominal segments, 0.52 inch; length of the seven thoraci¢ segments, about
0.64 inch. Height of third abdominal segment, 0.20 inch; height of each first
two or three thoracic segments, 0.12 inch; length of stylets about 0.31 inch.

Locality and position: Same as preceding.

INVERTEBRATES, 403

ACANTHOTELSON INHQUALIS, M. and W.

Pl. 32, fig. 7, Ta.

Acanthotelson inequalis, Mrnx and WortHEN, March, 1865, Proceed. Acad, Nat. Sci.,
Philad., p. 48.

THE specimen*upon which we proposed to found this species appears to agree
with the last in almost every respect, excepting in the proportional size and
the form of the segments. In the first place, the penultimate abdominal seg-
ment is nearly twice the length of any of the others, instead of being nearly or
quite of the same length; while the other abdominal segments (as seen in a side
view) are more cuneiform than in the last. Again, the fifth and sixth thoracic
segments are longer, particularly above, and the fourth shorter, than any of the
others, instead of all being of about the same length. We have not been able
to see the stylets, nor to make out the nature of the legs; but from a part of one
of those of the anterior pair, they would seem to be rather stouter than in the
last described species.

As these differences can scarcely be due to accidental distortion, we can but
regard this form, with the material now at hand for comparison, as a distinct
species. If we are correct in this view, it is probable good examples will show
other differences than those mentioned above.

Length of head, thorax and abdomen, 0.90 inch; length of head, 0.12 inch;
length of the seven thoracic segments, about 0.50 ineh; length of first five abdo-
minal segments, 0.26 inch; length of penultimate abdominal segment, 0.09 inch.
Height of third abdominal segment (flattened side view), 0.13 inch; height of
anterior thoracic segments, about 0.07 inch. Length of lower antennz at least
0.43 inch; length of upper not less than 0.36 inch, and probably a little more.

Locality and position: Same as last.

Genus PALAZOCARIS, M. and W.
*
(xalatoc, ancient; xapic, a shrimp.)
Palzocaris, MrEx and WorTHEN, March, 1865. Proceed. Acad. Nat. Sci., Philad., p. 48.

INNER and outer pairs of antenne of nearly equal length,
the former each bearing a well developed accessory appendage;
peduncles of both pairs shorter than the flagella. Head about
as long as the first two abdominal segments. Thoracic legs

404 PALEONTOLOGY OF ILLINOIS.

long and slender; anterior pair not chelate. Telson long,
tapering and horizontally flattened; stylets with first joint
very small, second double, and also flattened horizontally.

This‘is another remarkable type, presenting, so far as can be determined,
even a more puzzling combination of characters than that we have described
under the name Acanthotelson. In the nature of its antenne, with their appa-
rently well developed basal scales, the structure of its caudal appendages, and
its long, slender legs, spread out on each side, for walking in an erect attitude ;
as well as in the depressed, slender form of its abdomen and thorax, it seems
to present decidedly the aspect of a Macrural Decapod. Yet, on a closer exami-
nation, we can see no traces of a carapace, the thorax being apparently divided
into seven segments, like those of the abdomen, and each provided with a pair
of legs, as in the Yetradecapoda. If we are not mistaken in these latter
characters, and we certainly believe we are not, it must show a most extraordi-
nary union of characters, which, amongst recent crustacea, belong to different
primary divisions. From all that can be made out of its structure, we are
therefore inclined to view it as one of the “embryonic” or “comprehensive”
types, so often met with in various departments of paleontology, and which
furnish the advocates of the Darwinian hypothesis with some of their strongest
arguments.

For the present, this genus is placed, provisionally, along with the Tetrade-
capoda, though it cannot, we think, be included in any known family of that
division; while if it should prove to be an embryonic or low type of the Deca-
poda, it may be even necessary to establish for its reception a division of more
than family importance. It is proper to remark here, however, that we have
not seen any one specimen showing the caudal appendages we have described,
united with the other characters of-the thoracic and cephalic members, men-
tioned above. One imperfect specimen shows the seven thoracic and five or
six of the abdominal segments, with their legs and natatory appendages, the
head, antennze, and apparently their basal scales; while another shows the
caudal appendages, and all of the thoracic and abdominal segments, very dis-
tinctly, without any of the other members. The general agreement, however,
of these specimens, in the parts preserved in each, is such that scarcely a doubt
can be entertained, that they belong to the same species. Yet, in order to pre-
vent confusion, we would remark, that in case they should prove to belong to
different genera, or species, that it is the form showing the head, antenne, tho-
racic and abdominal segments, with their appendages, &c., that we regard as
the type of the genus and species.

INVERTEBRATES. 405

PALAOCARIS TyPUS, M. and W.

Pl. 32, fig. 5, 5a, 56, 5e, 5d.
Palxocaris typus, Mnux and WortuEn, March, 1865. Proceedings Acad. Nat. Sci.,
Philad., p. 49.

Lryear, with thorax slightly wider near the middle than the
abdomen ; thoracic and abdominal segments of nearly equal
length. Inner antenne equaling the length of the head and
thorax; peduncles stout, first joint a little longer and wider
than either of the other two, which are of nearly equal length,
and minutely and closely setigerous on their inner margins;
flagellum very slender, and minutely jointed; accessory ap-
pendage nearly or quite as long as the flagellum, and scarcely
differing from it otherwise. Outer antenne possibly a little
longer than the others, peduncles slightly longer than those of
the other pair, and like them minutely setigerous in front; basal
scales (?) oblong, about as long as first joint of peduncles,
squarely truncated. Thoracic legs slender and long, anterior
ones apparently not longer or larger than the others, none of
them (so far as can be seen) chelate, or with any of the seg-
ments enlarged; all the others with the first two or three joints
very short; fourth? joimt horizontally extended, tapering, and
about as long as four segments of the body; succeeding joints
(in the specimen examined) very slender and abruptly bent
downwards and backwards. Natatory abdominal appendages
acutely lancelinear, and some of them as long as four of the
abdominal segments. ‘Telson nearly as broad at the base as
the penultimate segment, tapering, and as long as two and a
half of the abdominal segments; minutely setigerous on each
side. Stylets, with first joint very minute; second with each
division as long as the telson, and lancelinear in form, with
pointed extremities, and parallel, more or less setigerous mar-
gins. Length of head, thorax and first six abdominal segments,
0.78 inch; do. of head, 0.12 inch; do. of the seven thoracic

406 PALZONTOLOGY OF ILLINOIS.

segments, 0.35 inch; do. of the first six abdominal segments,
about 0.31 inch. Length of telson, about 0.14 inch; do. of
stylets, near 0.13 inch. Length of lower or outer antenne,

not less than 0.38 inch (probably more), of which the pedun- —

cle forms 0.15 inch; do. of inner, 0.40 inch. Breadth of thorax,
0.13 inch.

Locality and position; Same as preceding.

DECAPODA.

MACRURA.

?Genus ANTHRAPAL AMON, Salter.

Anthrapalemon, Sauter, 1861. Quart. Jour. of Geol. Soc. of London, xvii, p. 529.

““Carapace scarcely so broad as long, (except when crushed
flat), simple, flatter than semicylindrical, the sides a little
arched outwards. A strong central ridge in front, projecting as
a thick (serrate ?) spine is separated by a concave space, or
slight furrow, from a posterior central ridge, which only occu-
pies Gin the type species, Grossari) a small portion of the
length. Front margin serrated. The outer antenne have
wide, square, basal joints, apparently without any advantage ;*
the second and third joints not much oblique; the rest about
as broad as long. Abdomen as broad as long, of six joints
(besides the telson), broad and very short; the pleure, except
the second, poimted. Telson very broad; appendages to the
penultimate joint, double on each side, subtrigonal,. broad.” —
(Salter.)

The name Anthrapalemon was proposed from its supposed affinities to the
recent genus Palemon, but Prof. Dana thinks it more nearly related to Zglea
and Galathea. The original type of the genus was found in the Coal Measures
of Scotland.

*Ts this not a misprint of the word appendage?

—S- —s *

INVERTEBRATES. 407

ANTHRAPALEMON GRACILIS, M. and W.
Pl. 32, fig 4, 4a, 4b, 4c.

Anthrapalemon gracilis, Munx and WortHEN, May, 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 50.

It is with considerable doubt that we venture to refer this species to Mr.
Salter’s genus, the only specimen we have seen being imperfect, and not in a
condition to show the more important characters. In form and general appear-
ance, however, as well as in such of its details as can be made out, it seems to
agree well with that genus. The specimen consists of the abdomen and
caudal appendages (in a crushed condition), and an impression in the
matrix of the under side of the carapace, the outer pair of antennze, and appa-
rently of the eyes. The carapace, as seen from above, presents nearly an
oblong form, excepting that the lateral margins are moderately convex in out-
line; the two extremities are truncated, and the breadth nearly or quite equal-
ing three-fourths the length. Its lateral margins, in front of the middle, are
each finely serrated by six small, sharp, projecting points, as in the type of the
genus, excepting that they are sharper and directed more obliquely forward.
At each antero-lateral angle there is also a considerably larger projecting point,
forming a short spine, exactly as in the type of the genus, excepting that it is
extended more nearly directly forward. The outer pair of antennze are moder-
ately stout, each peduncle showing three joints, diminishing rather gradually
in size, the first longer than wide and the other two apparently of nearly equal
length and breadth, and obliquely articulated. The flagellum is narrower at
its base than the last joint of the peduncle, and composed of very short seg-
ments, which are scarcely more than one-third as long as wide. The entire
length of the antennz can not be determined, as neither flagellum is entire in
the specimen examined; buf as the portion remaining tapers very gradually,
they were probably rather long. They are both, in the specimen examined,
deflected abruptly outwards, nearly at right angles to the longer diameter of the
carapace, which would seem, from the oblique articulation of the second and
third joints of the peduncles, to be their natural position. (Inner antennx
unknown.)

Immediately between the bases of the two outer antenne, the specimen
shows what appear to be impressions of the two globose eyes, which with their
peduncles extend forward about two thirds-as far as the peduncles of the an-
tennz. These may possibly be the peduncles of the inner antenne; but they
look very much like globular eyes, on more slender peduncles.

408 PALEONTOLOGY OF ILLINOIS.

The abdomen is more than half the length and about two-thirds the breadth
of the widest part of the carapace. It shows five short segments and apparently
part of another, the first of which is a little smaller and the second a little
larger than the others. None of them, however, are more than one-fifth as long ©
as the breadth of the abdomen.

The caudal appendages being unfortunately bent down and crushed, it is not
possible to make out the form of the telson or the details of the other parts,
though the whole together seem to have been wider than the abdomen, and as
wide as the carapace. No surface sculpturing can be clearly made out, though
there is some appearance of a few irregular scattering granules near the mar-
gins of the carapace. (Other parts unknown.)

It will be observed, from the foregoing remarks, that our specimen shows
no traces of the central spine or beak, extending forward from the anterior ex-
tremity of the carapace, nor of the longitudinal carina connected with it, which
constitutes such a marked feature in Anthapalemon. It is possible, however,
that this character may have been obliterated in breaking open the concretion
since our specimen only shows an impression of the under side of the carapace,
while the appendage alluded to projects forward from the upper side, and may
consequently be imbedded in the other half of the concretion, which we have
been unable to obtain. Still, as it is possible that this appendage may be want-
ing in our fossil, we should not be surprised if it would prove to belong to an
allied but distinct genus. J

Specifically, at least, it differs from A. Grossarit, of Salter, in the propor-
tionally much shorter joints of the flagella of its outer antennz and the oblique
articulations of the segments of their peduncles ; while the latter, as well as the
surface of other parts, are without any traces of the fine pitting represented by
Mr. Salter’s figures. Our specimen also shows traces of what appear to be
squarely truncated basal scales to the outer antennz, about as long as their first
joints, while Mr. Salter’s figure (1) represents apparently a triangular scale
over one of the antennz.

Length from the end of the caudal extremity to the anterior margin of the
carapace, 1 inch. Length of carapace, 0.60 inch; breadth of do., 0.43 inch.
Length of abdomen, about 0.30 inch; breadth of do., 0.27 inch. Length of
caudal appendages, 0.10 inch.

Locality and position: Same as preceding.

INVERTEBRATES. 409

MYRIAPODA
?Genus ANTHRACERPES, M. and W.

(avSpak, coal; épzw, to creep ;—in allusion to its Carboniferous age, and proba-
ble habits.)

ANTHRACERPES TyPus, M. and W.

Pl. 29, fig. 1, la.

Anthracerpes typus, Murx and WorTHEN, May, 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 51.

Tuis genus and species were founded upon a slender worm-like fossil, the
relations of which have not been very clearly determined. The specimen con-
sists of a well defined mould or impression left in a concretion, and measures
1.50 inches in length, and about 0.09 inch in breadth (height), as seen lying
upon one side. It is regularly arched from end to end, so as to form about
one-third of a circle of 0.65 inch radius. For most of its length, it is of very
uniform breadth or height, but it tapers very gradually towards what appears
to be the posterior end, where the last segment terminates in three or four
short, slender, hair-like, or spine-like appendages, directed backwards on a
- line with the general curve of the body. The other end being broken away in
the only specimen yet known, the nature of the head and its appendages can-
not be determined.

The entire body is distinctly articulated, and shows clearly nineteen seg-
ments, and part of another. The segments are of nearly uniform size, or only
vary from 0.08 to 0.10 inch in length; the last one, however, has only a
breadth or height of about 0.03 inch, and the next about twice that. Crossing
the segments near the upper side, may be seen in the mould an undefined fur-
row (produced by a ridge in the fossil itself), which bends downwards and then
up again as it passes across from side to side of each segment. ,Anteriorly it
is less distinct and placed very near the dorsal margin, but in tracing it back-
wards it is found to descend and become more defined, until it reaches the
fourth segment from the extremity; on this it passes obliquely downward to its
posterior inferior corner, so as not to be seen on any of the succeeding divis-
ions behind. Below the middle of each segment, there is in the mould a small
prominence, evidently marking the position of a corresponding pit in the fossil.
These agree in position and appearance with the spiracles or breathing aper-
tures in the Myriapoda. We have not been able to make out very clearly, any

pe) Oo. 5, 1866,

410 PALZONTOLOGY OF ILLINOIS.

indications of feet or other appendages; though there is near the base of each
segment of the mould, a short oblique impression, that may possibly have been
left by very small, feeble legs folded backwards.

As this fossil shows too many segments for a larval Insect, and has not the
aspect of an Annelid, we are rather inclined to view it as a Myriapod.

Locality and position: Same as preceding.

INSECTA.
LEPIDOPTERA.

Genus PALAZOCAMPA, M. and W.

(xadatos, ancient; xayzy, a caterpillar. )

PALMOCAMPA ANTHRAX, M. and W.

Pl. 32, fig. 3.

Palxocampa anthrax, Menx and WorTHEN, May, 1865. Proceed. Acad. Nat. Sci.,
Philad., p. 52. ‘

The fossil for which the above generic name is proposed, is about 0.90 inch
in length, and some 0.13 inch in breadth, exclusive of the projecting tufts of
hairs. It is an arcuate, worm-like body, that has been divided or split length-
wise in breaking open the concretion in which it is enveloped; so that it is
only a longitudinal section we see in looking at either half of the concretion.
At both extremities, and along the upper or convex side of the curve, we
observe densely packed tufts or fascicles of hairs individually radiating, as if
from small, wart-like protuberances. These hairs are straight, and about 0.30
inch in length. At one extremity, which appears to be the anterior, two of
the bundles of hairs are more radiating than the others, and directed forward.
The bundles distributed over the curved or dorsal side are regularly arranged,
and have each a general direction at right angles from the part of the arched
side from which they spring. At the posterior extremity there are also two
tufts directed backwards, the individual hairs of which are less radiating than
those at the other extremity. Between some of the bundles ranged along the
upper side, some shorter tufts are seen, which appear as if they originate in
another series of protuberances farther over on the other side embedded in the
matrix. If we suppose each of these principal bundles along the curved side,
and the two bundles at either end to each belong to a single segment, it would
make about ten or eleven segments to the entire body.

INVERTEBRATES. 411

& The specimen is not in a condition to show the head or feet; yet we are

strongly inclined: to believe from its form, and peculiar, regularly arranged
bundles of hairs, that itisa CATERPILLAR. If we are right in this suggestion,
its discovery is certainly an interesting one, as it would present an evidence of
the existence of Lepidopterous Insects, at a much earlier period in our world’s
history than has hitherto been suspected.

As this fossil will doubtless be met with in the Coal Measures at other locali-
ties, whether or not its relations to the mature Butterfly or Moth can ever
be positively established, it seems desirable for convenience of reference, that
it should receive a name; although we are unable to point out any well defined
characters from the only specimen seen, by which it can be distinguished from
the larva of several existing types. That there is any probability, however,
of its belonging to any existing genus, will, we think, not be maintained by any
person familiar with the range of generic types of Insects in time.

Locality and position: Same as last.

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LVL. ae tae chad (deca te AE LA, Leaed — me fr7 x,
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~

SUPPLEMENT TO DESCRIPTIONS OF INVERTEBRATES,

DESCRIPTIONS OF POLYZOA FROM THE PALAOZOIC ROCKS.

By H. A. PROUT, M. D.*

Coscintum WorTHENI, Prout.

Pl. 22, fig. 1.

Coscinopora Wortheni, 1860. Proceed. St. Louis Academy of Science, vol. 1, p. 571.

Potyzoum a leaf-like expansion, with a zig-zag midrib, eleva-
ted much above the déclining sides of the expansion; having
lateral branches given out at its salient points, which are like-
wise raised above the declining surfaces proceeding from it,
and which, as they proceed downward, change at right angles
to the original planes of expansion. Dimples long, elliptical ;
longitudinal diameter five to seven and a-half; transverse, one
to one-half m. m., oppositely pinnate both on the branches and
midrib, about four m.m. apart. Cells large, about four longi-
tudinally or transversely in the space of two m. m.; lips round,

* These descriptions were originally published by Dr. Prout in the Transactions of
the St. Louis Academy of Science. Had he lived to revise them for this Report, he
would doubtless have modified them in some respects, but as we have not at hand all
the specimens before him at the time he drew up the descriptions, we have thought it
better to give them as first written by him. M. and W.

SS

INVERTEBRATES. 413

thickened on the lower border, but not distinctly nasiform ;
direction of the cells, slightly upward and outward to the plane
of the surfaces from the midrib, being only slightly modified
by the elevation of the lateral branches. Intercellular spaces,
or net work, minutely capillary, as this tissue is developed from
the approximating and receding ridges of the sole.

This species is dedicated to Mr. A. H. Worthen, State Geologist of Illinois,
whose indefatigable labors in the field, and whose zeal and devotion to the inte-
rests of science, promise a rich harvest to Western Geology, and through whose

kindness and liberality we have been permitted to describe this and the follow-
ing species of Polyzoa.

Geological position and locality: Keokuk group, near Warsaw, Illinois.

COSCINIUM ELEGANS, Prout.
Pl. 22, fig. 2.
Coscinium elegans, Prout, 1860. Proceed. St. Louis Acad. of Sci., vol. i, p. 572.

Potyzoum a leaf-like expansion between what seems to be a
wide bifurcation of the midrib, rythmical dimples from each
branch pointing at first obliquely toward each other, meeting
irregularly toward the middle, and anastomosing towards the
' superior border, which is reflected upon itself by compression.
Dimples small, sharp and pointed, sometimes long; longitudi-
nally, or transversely, there are from five to six in a space of
twentym m. Cells large, almost visible to the naked eye,
with two prominent rounded lps, on the border of the dimples
they seem larger, and give to it a notched appearance.

Though the measurements in this species are very nearly the same as in C.
Keyserlingt, from the Keokuk group, we are inclined to refer it to a distinct
species, from the narrower, longer and more pointed dimples which are lanceo-
late, while in C. Keyserlingi they are broader and more oval; this, together
with the difference in the surface distribution of the dimples, will, it is believed,
warrant the distinction.

Geological position and locality: Lower beds of the St. Louis group; War-
saw, Illinois.

414 PALEONTOLOGY OF ILLINOIS.

CoscrniuM PLUMOsUM, Prout.
Pl. 22, fig. 3, 3a.
Coscinium plumosum, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. i, p. 572.

PoLtyzoum an irregular, leaf-like expansion, midrib sharp,
crust-like, raised irregularly above the surface, more or less
alternately branching, the spaces between the branches being
more or less concave, and rising upon their outer borders to be
united with other concave expansions from other branches.
Where the expansions are large, the long, narrow, rythmical
dimples, and corresponding ridges between them, are sometimes
curved like long plumes, gracefully waving over one another,
but the distribution of the dimples is mostly irregular, from
the irregular growth of the polyzoum. In one specimen, be-
longing to my own cabinet, the opposite face of the polyzoum
is broken up into cup-shaped cavities about the size and shape
of those which characterize the Michelinia favosa, Koninck.

These cup-shaped cells are bounded by interstitial plates,
with thin, salient and entire lips, denuded of chalices near the
margin, and are marked by rythmical and abortive spaces,
occasionally towards the centre. Sometimes this cupuliferous
expansion is found separate from the wider and more plumose
form of the polyzoum, and would, by those who are not careful
in distinguishing forms, be most probably referred to Michelima.

Geological position and locality : Lower beds of the St. Louis group; War-
saw, Illinois, and Barrett’s Station, St. Louis county, Missouri.

Coscinrum Micuetinia, Prout.
Pl. 22, fig. 4.
Coscinium Michelinia, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. i, p. 573.

PoLyzoum encrusting, extending over a considerable surface,
divided into larger or smaller, more or-less hexagonal, cup-

INVERTEBRATES. 415

shaped cavities, with salient tuberculated lips, bottoms of the
cups haying sometimes deep lanceolate, or oval depressions;
interior surfaces marked with irregular ridges covered by cell
pores or chalices, leaving occasional abortive spaces between
them. Thisis separated from the preceding species on account
of its more robust growth, the irregular notched or tubercula-
ted form of the lid, and the other characters assigned to it
above. The thin and salient lips of the plwmoswum would
scarcely assume the tuberculated form in a regular develop-
ment of the polyzoum.

Geological position and locality: Lower beds of the St. Louis group; War-
saw, Illinois.

2

CoScINIUM SAGANELLA, Prout.

Pl. 22, fig. 5.

Coscinium saganella, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. 1, p. 572.

Potyzoum expanding and encrusting; cell divisions. very
long, more or less irregularly hexangular, border of the septa
not as acute as in C. plumosum. I have provisionally sepa-
rated this from the two species above, until we are able to pro-
cure more perfect specimens. Named from its resemblance to
Saganella, Hall.

Geological position and locality : Lower beds of the St. Louis group; War-
saw, Illinois.

CoScINIUM TUBERCULATUM, Prout.

Pl. 22, fig. 6.

Coscinium tuberculatum, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. 1, p. 573.

PotyzouM an expansion somewhat concave and broadly
recurved toward one margin; tuberculations more or less
irregularly arranged in lines, with rythmical dimples marking
their summits; those towards the upper border are not dim-

416 PALEONTOLOGY OF ILLINOIS.

pled, and are still covered with chalices. Dimples oblong-oval;
in a space of twenty mm there are three to four in perpen-
dicular, and four in oblique lines. The mammillation is more

crowded towards the upper border, than near the central and.

lower part of the expansion. I was at first disposed to
regard this as an irregular form of the C. Keyserlingi, but the
arrangement of the dimples on the summits of the mammille,
and the existence of mammillary swellings instead of an irregu-
larly waved surface, will, it is believed, sufficiently distinguish
them from one another.

Geological position and locality: Keokuk group ; Warsaw, Illinois.

a
~

CoscINIUM ASTERIA, Prout.

Pl. 22, fig. 7, Ta.

Coscinium asteria, Prout, 1860. Proceed. St. Louis Acad. of Science, vol. i, p. 574.

Potyzoum a thin, irregular encrusting expansion, covered

with small chalices, except at certain points, which have the
appearance of oblong, radiating or substellar markings formed
of more prominent lines of chalices, with narrow abortive spaces
between them. These substellar dimples are more or less
irregular in form, the rays being sometimes unduly prolonged,
but are somewhat regularly arranged in relation to one another,
being more or less quincuncial in their distribution. The dis-
tance between the substellar points is in general about 5 m. m.

Geological position and locality: Keokuk group, Warsaw, Illinois.

CoSscINIUM ESCHARENSE, Prout.
Pl. 22, fig. 8, 8a.
Coscinium escharense, Prout, 1860. Proceed. St. Louis Acad. Science, vol. i, p. 574.

-Potyzoum a flat expansion, most probably encrusting, covered
with small chalices except at rythmical points, where the very

INVERTEBRATES. 417

.

shallow dimples seem to have denuded the surface. These
scars are somewhat irregular in form and distribution, but are
mostly oblong-oval in shape. This is no doubt a beautiful
species, but the specimen from which the description is drawn
is too small and imperfect to give a full view of all its characters.

Geological position and locality: Keokuk group, Warsaw, Illinois.

Gunus CYCLOPORA, Prout.

Cyclopora, Prout, 1860. Proceedings of St. Louis Academy of Science, vol. i, p. 574.

Potyzoum discoidal, frondescent, or irregularly incrusting ;
plates sometimes superposed, with subprismatic chalices longer
than broad, having their sides formed of a minutely porous inter-
stitial net-work, developed from a sole marked by transverse
bands or wrinkles more or less concentric, sometimes intercur-
rent or contorted, which are crossed at right angles by delicate,
slightly interrupted lines, separating the bases of the chalices
and radiating to an actual or imaginary centre almost as regu-
larly as the hymenium of a mushroom or the plates of a Fungia,
without being, like these, entire in their vertical expansion ;
chalice apertures on one or both faces shallow and expanded,
with interstitial spaces porous and net-like.

We have been induced, from the considerations which follow, to separate
this genus from the Ceriopora of Goldfuss. This genus, as defined by its
author, was rendered too comprehensive, and embraced within its limits too
large au assemblage of heterogeneous forms. Many of these have been
transferred by subsequent writers to other genera; and M. deOrbigny has
more recently excluded from its limits all expansive or incrusting forms,
restricting it to such as are ramose, having one or more layers of cells
superimposed upon one another, which includes in part the Jnwersaria of
Hagenow. We do not feel disposed to admit this mere modification in the
growth of the polyzoum, taken separately and alone, as an adequate basis for
generic distinction ; for it is well known that the superposition of layer upon
layer may be the result of age, and we have observed several times, in our in-

2253 Oor. 5, 1866.

418 PALEONTOLOGY OF ILLINOIS.

vestigations, that the expanding and incrusting forms may gradually assume
the ramose or convolute modes of growth. On reflection, it will be readily
perceived how these accidental modifications of form may be developed, for the
approximating borders of an expansion may fail to meet each other in exact
apposition, and the convolute form be induced, or an excess of development at
certain points on the surface or the margin of the polyzoum may give rise to
. the ramose forms; or if this latter should be arrested, to a simple tuberculation
of the surface.

It will be readily inferred, from these observations, how much difficulty at-
tends the correct classification of this order of the animal kingdom, in which
the generic and specific characters are so extremely limited. If we leave out
of consideration external forms, which are so invariable and definite in the
higher orders of animal life, and search into the minute anatomical elements
of their organization, we scarcely feel more secure in our distinctive determi-
nations; for when these are profoundly investigated and viewed in all their
relations, they seem but modifications, gradually taking their origin in a com-
mon type, as with the Anthozoa, modified as it is into all the beautiful and
diversified forms which it presents. We are enabled to ground our groupings
into families and genera only on developments, when not accidental, which re-
sult from the plastic calcareous or corneous secretions and the form and general
arrangement of the cells or chalices; while for specific distinctions we are
restricted to narrower limits, or to details of minor importance, such as the
relative size and form of the cells, their number and distance apart, and some-
times to phenomena of a purely negative character.

These principles, when more accurately defined, and limited to their proper
sphere, may lead to a more correct classification or a more natural arrangement
of the Polyzoa than those which have been previously proposed. It must be
admitted that the present classification ‘is almost as defective in Polyzoology
as when the profound and gifted mind of de Orbigny essayed to establish order
where the wildest confusion had previously prevailed. In all deference to his
genius and his labors, which are worthy of all praise, we are compelled to be-
lieve that he has given too great an expansion to many parts of his system by
the multiplication of genera in the different groups, and has sometimes associa-
ted forms which have no generic affinities, from losing sight of the terms or the
characters on which his distinctions were founded. Those who fully compre-
hend the difficulties of a correct classification of these often minutely developed
forms of living beings, will regard with proper indulgence these errors in an
attempt to restore order where nothing but the most indiscriminate complexity
had formerly existed. In attempting to make our descriptions conform to a
strictly natural system, we are not certain that we shall meet with greater suc-
cess. All that we can promise is to adhere strictly to this basis of classification,

INVERTEBRATES. 419

having full faith that principles grounded in nature, fully comprehended and
properly interpreted, cannot very far mislead the earnest and humble inquirer
after truth. We hope, by our labors, to remove some of the difficulties which
oppose themselves to a better understanding of the zoological and paleeontologi-
cal value of this beautiful and interesting, but hitherto much neglected order
of fossil forms.

The genus established above is one which embraces several discoidal and
incrusting forms. The concentric, more or less banded basis or sole which
from its thickening into folds or ridges, gives more strength and firmness to
the net-work in which the tiny workers above were implanted, sufficiently dis-
tinguishes it from the Semicoscinium, with its more or less lamellar and con-
densed intercellular spaces, and its sole condensed in parallel ridges; from
Coscinium, with its raised chalice lips, and its sole formed of approximating and
receding ridges; or from Chztfetes, with its more condensed intercellular spaces
and its longer tubes, which take their origin in an uncondensed cellular or
cancellous structure. The basis of its separation from its congeners of the
same group is founded mainly upon the form and character of its sole. This
banded arrangement of the condensed base seems to be represented in Ceriopora
verrucosa, Gold., tab. x, fig. 6c, which most probably belongs to this genus.
Now, it may be said that where the general characters and the arrangement of
the chalices are nearly the same, the distinctions in the form of the sole possess
little or no generic value; but this objection can have but little force, unless it
can be proved that these differences in the character of the basal plates, and
the direction and distribution of the chalices which impressed these forms upon
them, were accidental, and not strictly the result of differences in the laws
which regulate the definite development of organic forms.

CYCLOPORA FUNGIA, Prout.

Pl. 22, fig. 9, 9a, 95.
Cyclopora fungia, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. 1, p. 577.

Potyzoum a flattened disc, about two inches in diameter,
with a central depression on the lower surface, and a some-
what irregular margin; strie or sole-lines radiating from the
centre, somewhat whorled at first, delicate, interrupted or
jagged, being apparently formed of long, slightly waved, sep-
tate, flattened tubes, in juxtaposition on a common plane of
expansion; concentric rings more or less rugosely plicated, and

420 PALEONTOLOGY OF ILLINOIS.

marked by depressions, which seem to have resulted from
abortive cells larger than those which formed the radiating
strix. As the annulations become more prominent toward the
border, the striations become less distinct and more irregular.

Chalices only seen upon the upper face by grinding the
lower surface, where they appear to be round or subprismatic,
longer than broad, vertical in direction, alternately juxtaposed
in radiating lines, with no sheaths distinct from the plexiform
interchalicular spaces, which are formed by the union of minute
cells, varying in size and development.

A careless observer might refer this species to the genus Fungia, as in
general appearance it resembles very closely some of the discoidal forms of this
coral, more particularly the Pungia discoidea, Gold., tab. xiv, fig. 9a. But a
minute examination of its structure renders it manifest that it is a true
polyzoan, allied somewhat to Ceriopora (Gold.) The chalices and the inter-
chalicular spaces are not septate, for we have found on careful examination
that the septa in the forms submitted to examination are more imaginary than

real, being caused by the breaking in of cells forming a part of the net-like
interchalicular spaces.

Geological position and locality : Keokuk group, St. Francisville, Mo.

CYCLOPORA DISCOIDEA, Prout.

Pl. 22, fig. 10.
Cyclopora discoidea, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. 1, p. 578.

PoLyzoum a flattened subconcave or subconvex expansion,
with a central elevation; discoidal portion about two or two
_and a half inches wide, with radiations distinctly marked,
showing the bases of the chalices on the upper surface in con-
nected lines and alternate series. Margin irregular, running
into irregular frondescent expansions, which still preserve the
concentric form of the banded sole. One specimen is so deeply
concave as to become infundibuliform; chalices only on one
side, larger and not so long as in C. fungia.

Geological position and locality: Keokuk group, Warsaw, Illinois.

INVERTEBRATES, 431

CYCLOPORA POLYMORPHA, Prout.
Pl. 21, fig. 5, 5a, 5b. ‘
Cyclopora polymorpha, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. 1, p. 578.

Potyzoum a large incrusting expansion, with the ridges vari-
ously contorted without the appearance of a disc, although it
seems to have had several centres of development. Chalices
larger than in the two former species, with the interchalicular
spaces more rugose; chalices on both faces, with evidences
here and there of a disposition in the layers to superposition.
The specimen from which this description is drawn is about
four inches broad by as many long, and the whole expansion
of the polyzoum seems to have been several times as broad as
the space comprehended by these measurements. It is, we
think, evidently specifically different from the two preceding
forms.

_ Geological position and locality: Chester group, Pope county, Illinois. _

Genus POLYPORA, McCoy, 1844.
(Carb. Foss. Ireland, p. 206.)
PotyporA HALLIANA, Prout.
Pl. 21, fig. 4, 4a, 40.

Polypora Halliana, Prout, 1860. Proceed. St. Louis Acad. Sci., vol. i, p. 580.

Potyzoum a broad fan-shaped expansion, with apparently
entire rigid longitudinal rays radiating from a central point,
with fenestrules obvious to the naked eye. Longitudinal rays
regular, on a plane of expansion only slightly waved without
folds or plications, round, straight, or direct, bifurcating nearly
‘oppositely near the base, about: two lines near the middle,
about four and not so frequently towards the border. Dissepi-
ments mostly alternate, small, depressed, often not much more
than connecting points between the longitudinal rays; about
one-fourth as long as the fenestrules, and somewhat expanded

422 PALAONTOLOGY OF ILLINOIS.

at their junction with the longitudinal rays. Owing to their
depression the spaces between the rays appear as long furrows,
somewhat notched. Fenestrules long, oval and narrow, being
from twice to three times as long as broad. Two longitudi-
nally in a space of two lines, three transversely. Chalices
small, pore-like, juxtaposed in sinistral, spiral lines upon the
longitudinal rays; about four lines of alternate chalices, and
sometimes five, rarely three towards the base. In straight
lines there are about four to each fenestrule, in zigzag eight to
nine.

Comparisons—Resembles P. Mexicana, but differs by the want of contrac-
tion and expansion above and below the bifurcations, in the fewer number of
chalices upon the borders of the fenestrules, and in the general form of the
polyzoum.

Geological position and locality: Base of the St. Louis group; Warsaw, IIl.

POLYPORA GRACILIS, Prout.

Pl. 21, fig. 1, la.

Polypora gracilis, Prout, 1860, Proceed. St. Louis Acad. Sci., vol. i, p. 580.

Potyzoum a long, narrow net-work, proceeding from a pedi-
cle with longitudinal rays of nearly uniform size, appearing to
branch much more frequently towards the margins than near
the base. Longitudinal rays round, dilating very slightly at
the bifurcations; spaces between the bifurcations long, lanceo-

late, dichotomizations from two to five lines apart, but on par-

allel rays nearly opposite. Dissepiments very small, expanded
at their junction with the longitudinal rays, dividing them into
a somewhat irregular net-work. Fenestrules long, oval, but
sometimes quadrangular, about as broad as the large, longitu-
dinal rays. Chalices in lines alternately distributed with cal-
careous raised lips when perfect, common to the chalice open-
ings, which are sometimes depressed at certain points, or
elevated by the expansion of the cells forming the substance of

INVERTEBRATES. 423

the longitudinal rays; four to five lines of chalices on each
ray, mostly dextral; about fifteen to twenty to each oscule,
with no interjacent lines of very minute pores between them ;
when the longitudinal rays are worn they appear minutely
tubular striate. Reverse long, tuberculate, anfractious, with
occasional small pores.

Comparisons.—This very large and graceful species of Polypora is allied
somewhat, in character, to the Retepora laza, Phillips (Polypora, McCoy;
Gorgonia ripisteria, Goldfuss, vii, fig. 2), but differs from it in being much
larger, in branching more regularly, in having no interjacent lines of pores
between the chalices, and in the long, ovate form of its oscules.

Geological position and locality: Keokuk group; Warsaw, Illinois.

PotyporA HAMILTONENSIS, Prout.
Pl. 21, fig. 6, 6a.
Polypora Hamiltonensis, Prout. MS.

Potyzoum depressed infundibuliform, or nearly flattened ;
rays bifurcating rather regularly, rounded and apparently
smooth below; dissepiments short, expanding at their connec-
tion with the rays, which they nearly or quite equal in size,
scarcely more impressed than the rays, with which they also
agree in being rounded and nearly smooth on the under, or
non-poriferous side. Fenestrules oval, or oval-subcircular,
alternately arranged. Cell pores small, arranged in oblique
rows varying from three to four in each oblique range across
the rays, generally about four to each longitudinal row opposite
each fenestrule. Entire size unknown; fenestrules usually six
or seven in 0.20 inch, measuring longitudinally parallel to the
rays; and about eight in the same space, counting them in the
oblique, transverse rows.

Geological position and locality : New Buffalo, Iowa, where it is common on
slabs, with one or more species of Fenestella, Crinoid columns, etc. Hamilton
group, of the Devonian series. Also, less abundantly, in same position at
Rock Island, Illinois.

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PALHONTOLOGY OF ILLINOIS.

SECTION III.

REPORT ON THE FOSSIL PLANTS OF ILLINOIS.

By LEO LESQUEREUX.

may Oor. 6, 1866.

_

FOSSIL PLANTS.

AN ENUMERATION OF THE FOSSIL PLANTS FOUND IN THE
COAL MEASURES OF ILLINOIS, WITH DESCRIPTIONS OF
THE NEW SPECIES.

FIRST DIVISION.—FERN LEAVES.

Genus Nevuropreris, Brgt. Frond pinnately or bitripinnately
divided ; pinnules or leaflets cordate at the base, or nearly so,
rarely narrowed; entire or cut-toothed, lanceolate, broadly
oval, round, kidney-shaped, etc., joined to the rachis by the
middle or the base of the medial nerve, which is sometimes
elongated into a short pedicel. Nerves oblique arched, either
branching from a medial nerve, which disappears in ascending,
or flabellate and dichotomous from the base. This definition
unites both genera, Newropteris and Nephropteris, Bret.

Neuropteris hirsuta, Lsqx. Geol. Rep. of Penn., p. 857, tab. 3,
fig. 6, and tab. 4, fig. 1 to 16. This is a very polymorphous
species. Pl. 35, fig. 8,9 and 10 of this report, represent large
leaflets, placed around the stem of this species at the point of
attachment of a primary or secondary pinna. Such leaflets were
formerly separated and placed in the genus Nephropteris or
Cyclopteris, Brgt. Fig. 6, of the same plate, is one of the
smallest leaflets of this species. Fig. 7 shows a peculiar and

498 PALAONTOLOGY OF ILLINOIS.

abnormal division of a terminal leaflet of the same. Found in
the whole thickness and over the whole extent of the Coal

Measures, especially in connection with coal No.1 B. Abounds .

at Murphysboro, Jackson county, Illinois.

Neuropteris Clarksoni, Lsqx. Geol. Rep. of Penn., p. 857,
tab. 6, fig. 1-4. A small specimen from Mazon creek, Grundy
county, Illinois; found by Mr. J. Even.* Coal No. 3.

Neuropteris flexuosa, Brgt. Hist. des Veg. Foss., 1, p. 239,
tab. 65, fig. 2 and 3, and tab. 68, fig. 2. Abounds at Murphys-
boro. It follows the same distribution as the former.

Neuropteris rotundifolia, Brgt. Hist. des. Veg. Foss., 1, p.
238, tab. 70, fig. 1. Found at Grayville, White county, Ill.
It is perhaps a variety of the former. Upper Coal Measures.

Neuropteris plicata, Sternb. Vers., 2, p. 74, tab. 19, fig. 1-3.
Locality: Mazon creek, Grundy county, Illinois. Coal No. 3.

Neuropteris Loschii, Brgt. Hist. des Veg. Foss., 1, p. 242, tab.
73. Locality: Mazon creek. Same position as last.

Neuropteris vermicularis, Lsqx. Geol. Rep. of Ky., vol. 4, p.
434, (pl. 2, fig. 7, ined.) Locality: Mazon creek. Same posi-
tion.

Neuropteris tenuifolia, Brgt. Hist. des Veg. Foss., 1, p. 241,
tab. 72, fig. 3. There is in the State Cabinet at Springfield, a

specimen of this species, marked Grayville, and another from ~

Colchester. Upper Coal Measures.

Neuropteris rarinervis, Bunb. PI. 33, fig. 1 to 5, and Pl. 34,
fig. landla. This species has a tripinnate or polypinnate
frond; secondary pinne alternate, long, linear or linear-lance-
olate; pinnules alternate, contiguous or distant, oblong, obtuse,
cordate and somewhat dilated at the base, with the exterior

* To prevent the necessity of numerous repetitions, I will state once for all, that all
the specimens indicated from Mazon creek, Grundy county, were communicated by
Mr. Joseph Even, and found in iron-stone concretions.

:

/

FOSSIL PLANTS. 429

lobe a little extended, a little undulate on the margin; termi-
nal pinnule deltoid, nearly trilobate; superior pinne simple,
_linear-lanceolate, pinnatifid or with slightly undulate margins;
medial nerve distinct, strong near the base; veins distinct, flat,
thick, bifurcate.

Our species is evidently the same as that published by Mr.
Bunbury from the coal fields of Nova Scotia, though his figure
represents the nervation somewhat differently from what it is
on our specimens. The number of veinlets along each border
of the leaflets varies according to their size. They are equi-
distant, and not separated in fascicles, as shown by Mr. Bun-
bury’s figure. In the fig. 1 of our plate 34, the veinlets are so
close, and the medial nerve so strong, that the species looks
more like a Pecopteris than a Neuropteris. The veins and vein-
lets of this Newropteris, seen through a glass, appear broad,
flattened, or rather divided into two in their whole length, their
borders being inflated on both sides, and the middle depressed,
as seen in the enlarged part, pl. 33, fig. 4 a, and pl. 34, fig. La.
This peculiar conformation of the veins shows the identity of
the large leaves (pl. 33, fig. 3, 4, 5) with this species.* It is
common enough in our Coal Measures. I have found it in
Pennsylvania, Kentucky and Illinois, generally in connection
with coal No. 3. The fine specimens figured pl. 33, fig. 1 and
4, come from Murphysboro, and were presented to me by Mr.
James Sampson, of New Harmony, Indiana. A number of
specimens in the State Cabinet at Springfield have been found
at the same place, and also at DuQuoin. Lower Coal Measures.

Neuropteris Villiersit, Brgt.. Hist. des Veg. Foss., pl. 1, p.
233, tab. 64, fig. 1. A very rare species, found only in small
specimens. Locality: Murphysboro, Jackson county. Same
position as last.

* JI have lately received from Newport, R.I., a specimen of this species, with a
round leaf (Cyclopteris) attached to the base of a branch, bearing small lanceolate,
oblong leaflets (Vewropteris), a conclusive proof of the identity of both forms.

430 PALEONTOLOGY OF ILLINOIS.

Neuropteris heterophylla, Brgt. Hist. des Veg. Foss., 1, p.
243, tab. 71 and 72, fig. 2. This species is abundant in the

Anthracite basin of Pennsylvania, in the shales of coal No. 3.

and 4, but apparently rare westward. The State Cabinet has
a single small specimen on sandstone, from Drury’s Landing,
Rock Island county, Illinois. Lower Coal Measures.

Neuropteris Desori, Lsqx. - Geol. Report Penn., p. 859, tab.
5, fig. 11 and 12, and tab. 20, fig. 5 to 8. Locality: Mazon
creek. A very small specimen, referable with doubt to this
species. Coal No. 3.

Neuropteris fimbriata, Lsqx. Geol. Report Penn., p. 855, pl.
4, fig, 17 and 18. The specimen of this species (No. 351 of
the State Cabinet) was found by myself at Murphysboro, Illi-
nois. It is more like a true Newropteris than any other speci-
men of this fine species. The fringe of the leaflets is shorter

and comes nearer that of Neuropteris dentata, Lsqx., with -

which it may be identical. Lower Coal Measures.

_ Neuropteris Eventi, Sp. nov. Pl. 36, fig.4. Frond pinnately
divided into alternate, distant, ovate, cordate, obtuse leaflets,
attached to the main flexuous rachis by a short pedicel. Veins
thin, distant, forking twice, either flabellate from the base or
emerging from a short, thin, scarcely noticeable medial nerve.
By the general outline of the leaflets, this beautiful species has
some likeness with Newropteris crenulata, Brgt., but the mar-
gins of our species are evidently entire, and the veins much
thinner, though the derm appears pretty thick. The round,
smooth, flexuous rachis looks as if this species had been a climb-
ing one. Found at Mazon creek by Mr. Joseph Even, who
has greatly enriched the fossil flora of Illinois by his researches,
and to whom the species is dedicated.

Neuropteris pachyderma, Sp. nov. Pl. 36, fig, 5. Frond
pinnately divided; divisions distant, opposite, sessile, ovate,
somewhat pointed, cordate at the base, thick, convex, with a

FOSSIL PLANTS. 431

narrow, flattened or recurved margin; nervation obsolete;
veins distant and apparently forking once only. The scarcely
visible veins are more distant than in the former species. ~ The
surface of the leaves is traversed crosswise by irregular wrin-
kles or fissures through the thick epidermis. The convex,
narrowly-margined or flattened leaflets look as if their under
surface was thickly covered with spores, though no trace of
them can be seen marked by compression upon the upper sur-
face. Locality: Mazon creek. Coal No. 3.

Neuropteris inflata, Sp. nov. Pl. 37, fig. 2. Apparently
bipinnately divided. Leaflets large, nearly round or broad
oval, rounded at the base, lanceolate above, attached to the
rachis by a broad base, inflated or convex on the upper surface.
Nerves flabellate, dichotomous or forking in ascending, arched,
distinct,~thin, resembling those of Newropteris hirsuta, but
better marked and inflated near the base. The specimen fig-
ured is also from Mazon creek. It shows two opposite leaflets
attached to a narrow, irregularly striated rachis, which is appa-
rently connected with a broader main stem, about half an inch
thick. Another specimen from the same locality represents
the upper part of a pinna, with a number of leaflets, each
attached to the rachis by a broad base and diversely folded and
superposed. On one side of the branches the leaves are round,
like those of our figure, while on the other they are longer, |
oval-lanceolate, somewhat pointed, resembling the large form
of Neuropteris hirsuta, but shorter and with a convex surface.
From these specimens, and also from two fine ones preserved in
the Cabinet of Princeton College, New Jersey, the upper sur-
face of this species appears always convex or inflated.

_ Neuropteris verbencefolia, Spamove | Plo, hel. This re
markable species is known only by a single specimen from
Mazon creek. It is a single leaflet, oval-lanceolate in outline,
obtuse at the top, taper-pointed towards the apparently petioled
base. The margin is regularly and deeply serrate. The veins

432 PALAONTOLOGY OF ILLINOIS.

pinnately branching from a thin medial nerve, are thin, dis-
tant, oblique, arched, forking once only above the middle, each
branch ascending to the point of one of the teeth of the leaf.
This species has no relation with any other species of our Coal
Measures, except perhaps with Neuropteris fissa, Lsqx. (Geol.
Report of Fenn., p. 857), which it resembles only by the dis-
tant veinlets, and the large size of the leaves.

Genus OpontorteEris, Bret. Frond bi or tripinnately branch-
ing; pinnules variable, attached to the rachis by the entire,
sometimes decurrent or enlarged base; medial nerve slightly
or not at all marked; nervules simple or furcate, some of them
emerging from the rachis and parallel to each other, some flabel-
late from the base and dichotomous.

Odontopteris Worthent, Sp. nov. Pl. 36, fig. land 16. Frond

bipinnatifid. Primary divisions alternate or opposite, ovate, —

lanceolate, unequally lobed, either entire in the lower part or
scarcely divided, with a kidney-shaped leaflet under the point
of attachment to the main rachis, or pinnately alternately divi-
ded in obovate, obtuse, decurrent divisions, which are gener-
ally curved backwards and separated below the middle by
an acute simus; terminal leaflet either cut in two obovate, obtuse
divisions, or entire larger, deltoid, obtuse, with short alternate
lobes near the base; veins very thin and close, once or twice
forked, slightly arched, emerging from a large, flat medial nerve;
surface apparently covered with short, straight hairs. Though
this beautiful species has some of its large leaflets nearly entire,
with arched and dichotomous veins, like those of a Newropteris,
it is evidently, by its parallel basilar nervation, a true Odon-
topteris. In the upper part of the frond the pinnee are deeply,
pinnately divided, while the inferior ones are more and more
entire, with always a kidney-shaped small leaflet attached to
the under side of this base. By these leaflets, and also by its
apparently hairy surface, this species has some likeness with
Neuropteris hirsuta; but it can not be considered as a variety of

ee

FOSSIL PLANTS. 433

this polymorphous fossil fern, especially on account of the nery-
ation. This nervation is apparently like that of Dyctiopteris
newropteroides, Gutb., in Geinitz Verst., p. 23, tab. 28, fig. 6;
and if the short cross lines marked on the surface of the leaves,
and resembling short hairs, are divisions of the veinlets, our
species would be a new Dyctiopteris. But on account of the
fineness of the veins, it is impossible to decide if these lines—
generally placed in the same direction, but sometimes irregular
and even stronger than the veinlets, as marked in our fig. 16—
are true hairs or subdivisions of the veins, and thus constitute
a peculiar reticulation. Locality: Mazon creek, Grundy county.

Odontopteris heterophylla, Sp. nov. Pl. 38, fig. 2-5. Frond
bipinnately and tripinnately irregularly divided; pinneze lanceo-
late in outline or cordate ovate; pinnules either entire, oblong
or obovate, obtuse, decurrent on the rachis, becoming broader,
shorter, cuneiform, even, kidney-shaped at the base of the
pinne, or elongated, diversely lobed with unequal, long-linear
or short, lanceolate, pointed divisions; terminal leaflet large,
ovate-deltoid, obtuse, with an obtuse alternate short lobe on each
side; veins sharply marked, inflated. near the base, generally
twice, rarely thrice forking. In the decurrent leaflets the veins
are also somewhat decurrent on the rachis, as in fig. 2a; in the
oval, broad leaflets the veins are obliquely attached to it—fig.
4a (somewhat enlarged, like the former). This very variable
species is known only from small specimens, found only at
Murphysboro. The one of fig. 5 was presented to me by Mr.
James Sampson, of New Harmony, Indiana. The others were
- found by Prof. A. H. Worthen and myself, and belong to the
State Cabinet of Illinois.

Odontopteris subcuneata, Bunb. Quat. Geol. Journ., vol. 3, p.
23. It is somewhat doubtful if the branch of Odontopteris,
figured in our pl. 36, fig. 8, is the same species as that of M.
Bunbury. The general form of the leaflets, especially the

—99 |. Oor. §, 1866,

434 PALEONTOLOGY OF ILLINOIS.

basilar prolongation into an ear-like appendage, and also the

thinness and ramification of the slightly arched and dichoto-
mous veins, are the same. But in Mr. Bunbury’s species the
leaflets have all the same obovate, obtuse or oblanceolate form
and are opposite, while in ours these leaflets vary from short,
kidney-shaped, very obtuse, to oblong, lanceolate, acute in out-
line, and are alternate. The figure of the Nova Scotia species
also shows, perhaps by mistake, the veins running into or de-
current upon the main rachis, while in ours they evidently
come out from the base of the leaflets. Nevertheless these dif-
ferences are not marked enough to authorize a specific separa-
tion, and we may consider this branch of ours as the inferior
part, while Mr. Bunbury’s specimen represents an upper part
of a frond. By the general outline and the apparent variations
of the leaflets, this species is related to the former; but it
greatly differs by the thinner, closer and arched veins. Lo-
cality: Mazon creek, Grundy county, Illinois. Coal No. 3.

Odontopteris cequalis, Sp. nov. Pl. 36, fig. 2. Nothing is
preserved of this peculiar species but the broken part figured
here. From this it is not possible to know anything about the
primary division of this fossil fern. By its peculiar nervation,
and the regularity of the obtuse pinne, this species is different
from any other of this genus. The pinna was apparently
long and linear; its leaflets, separated to below the middle by
an acute sinus, either slightly decurrent or perpendicular on
the narrow, convex, smooth rachis, are short, about of equal
size, rounded at the top; the veins, though thin, are distinct,
distant, all parallel at and near the base, oblique or perpendicu-
lar, following the direction of the leaflets, and simple or fork-
ing once only from above the middle. The thinness of the
veins and the general form of the smooth, convex leaflets, sepa-
rate this species from Odontopteris Schlothemi, Brgt. Locality
-and. position :. same as last.

ee ee ee ee

qj

- FOSSIL PLANTS, 435

Genus SPHENOPTERIS, Brgt. Frond bi or tripolypinnatefid,
pinnules generally wedge-form or narrowed at the base, lobed,
with the inferior division larger; nervation pinnate, primary
veins ascending to the margin, flexuous, secondary veins dicho-
tomous, forking once, twice or thrice in each lobe.

Sphenopteris paupercula, Sp. nov. Pl. 41, fig. 4 and 4a.
Frond bipinnatifid ; pinne linear-lanceolate, apparently long,
with a strong rachis; pinnules nearly equal, distant, oblong
obtuse, somewhat decurrent by a narrowed base, and oblique
on the rachis; margins equally sinuate, or nearly pinnately
round lobed; medial nerve flat, broad, pinnately branching in
each lobe; veins forking two or three times. Distantly rela-
ted to Pecopteris Schenbemiana, Brgt., of the Keuper of Europe.

The figured specimen is from St. John, Perry county. I have

got afew others from Pennsylvania, but all broken and too
small. Coal No. 3.

Sphenopteris irregularis, Sternb. Vers., 2, p. 63, tab. 17, fig.
4. A few specimens of this fine species are preserved in the
State Cabinet. Locality: Colchester, McDonough county. Coal
No. 3. 7

Sphenopteris obtusiloba, Bret. Hist. des Veg. Foss., 1, p. 204,
tab. 53, fig. 2. The only specimen of this species in the State
Cabinet is poor. It comes from Murphysboro, Jackson county.
Lower Coal Measures.

Sphenopteris latifolia, Brgt. Mist. des Veg. Foss., 1, p. 208,
tab. 57, fig. 1 to 6. One specimen from Mazon creek shows
well the general outline of this species, but the leaflets appear
somewhat denticulate by the strong veins projecting beyond
the margins and forming points.

Sphenopteris rigida, Brgt. Hist. des Veg. Foss., 1, p. 201,
tab. 53, fig. 4. The species figured in our plate 39, fig. 5, 5a,
and 6, 6a, is, by its ramification, the form of the leaflets, and
the obscure nervation, apparently the same as Brongniart’s.

436 PALAONTOLOGY OF ILLINOIS.

But there is a difference worth mentioning. M. Brongniart
says that the leaves are coriaceous and very smooth; while in
our specimens the surface is evidently rugose, as if it had been
originally squamose or hairy. On a specimen in the Cabinet
of Amherst College, the surface of the leaflets appear perfectly
smooth and the veins deeply marked, thus agreeing exactly
with Brongniart’s description. The difference is probably
casual, and caused by a more or less prolonged masceration of
the plants, before the solidification of the shales. The Illinois
specimens are from Colchester (coal No. 3), and the fern has
preserved its epidermis transformed into a thin coat of coal.
The specimen at Amherst has a naked surface.

Sphenopteris abbreviata, Lsqx. Geol. Rept. Penna., p. 861,
tab. 9, fig. 1 and 16. Mazon creek; a small specimen.

Genus HyMENOPHYLLITES, Gopp. Frond membranaceous,
many times regularly pinnately divided or irregularly cut, lobed
with pinnatifid or dichotomous divisions decurring on a broad
common rachis, which is sometimes indistinct; veins pinnate,
. percurrent, solitary in each division.

Hymenophyllites pinnatifidus, Sp. nov. Pl. 34, fig. 2 and 2a.
Frond tripinnate; primary pinne large, with divisions alter-
nate and open, perpendicular on the smooth round rachis;
secondary pinne lanceolate, with alternate ovate-lanceolate
short pinnules, which are also pinnately parted in ridge-shaped
divisions. These are generally cut in two or three lanceolate,
obtuse lobes, the terminal one simple and small. The species
is related to Hymenophyllites Hildrethi, Lsqx., Geol. Rept. Penn.,
p. 863, tab. 9, fig. 5 and 5a, differing from it by the ramifica-
tion, the shorter and more obtuse lobes, etc., and also (but dis-
tantly) to Sphenopteris lanceolata, Gutt. Abundant at St. John
and Colchester, in the roof shales of coal No. 3.

Hymenophyllites spinosus (Sphenopteris), Goppt. Gattg. Foss.,
pl. 3-4, p. 70, tab. 12. This very fine and rare species is

FOSSIL PLANTS. 437

fieured pl. 34, fig. 3 and 3a. It does not differ from the
European species. Only in ours the nervation, till now unde-
scribed, is, though obsolete, distinct enough for examination.
The main or medial nerve is formed from a facicle of very thin,
filiform, parallel veinlets forking with its division, percurrent
or running to the margin, where they still appear double.
This nervation renders the base of the leaflets and the common,
somewhat winged rachis, inflated or thickened in the middle.
It is thus a true Hymenophyllites, more properly belonging to
the second division (Pachyphyllum). This species was found
at Colchester. Coal No. 3.

Hymenophyllites alatus, Brgt. Pl. 39, fig. 1.

Sphenopteris alata, Brgt. Hist. des Veg. Foss., 1, p. 180, tab.
48, fig. 1. Our species is apparently identical with that of
Europe, but like most of our other species of fossil plants, it
has some peculiar characters, which do not perfectly accord
with the typical form. The lobes or divisions of the pinnse
.are not perpendicular on the rachis, asin M. Brongniart’s figure,
but oblique and much more approached to each other; and the
veins, pretty thick at and near the base, become thinner in
ascending and dividing, and are lost or obsolete near the mar-
gins. A fruiting specimen, figured by Geinitz, Verst., tab. 24,
* fig. 15, resembles our American form more than Brongniart’s.
Locality: Roof shales at Colchester. A good specimen of this
species has recently been found at Morris, Grundy county—
showing that our species is identical with the European.

Hymenophyllites hirsutus? Lsqx.

Pachyphyllum hirsutum? Lsqx. Geol. Rept. of Penna., p.863,
tab. 8, fig. 3. The specimens are too small for a satisfactory
examination. ‘The surface of the stem is hairy, but the lobes
or divisions are more obtuse than in the Pennsylvania speci-
men. Mazon creek, Grundy county. Coal No. 3.

438 PALEONTOLOGY OF ILLINOIS.

Hymenophyllites Clarkii, Sp. nov. Pl. 39, fig. 7. Frond ap-
parently large, irregularly divided; primary divisions oblique,
decurrent, obovate, irregularly subpinnately cut in obtuse, ob-
lanceolate, short, subreflexed lobes; veins fasciculate at the
base and along the common inflated rachis, simple in ascending
into the secondary or tertiary divisions, or irregularly dichoto-
mous, thin, ascending to the sinuses of each lobe. It is dis.
tantly related to Hymenophyllites Guthierianus, Ung. We
know it only from small specimens. The first one sent to me
was found by Mr. James H. Clark, of Newport, R. I. The
one figured here is from Mazon creek, Grundy county, Illinois,

Genus ALETHOPTERIS, Sternb. and Gopp. Frond bitripinnate
or tripinnatifid; secondary nerves perpendicular or nearly ob-
lique to the medial nerve, simple, once or twice forking; mar-
gins of the pinnules often revolute.

Alethopteris aquilina, Brgt. Hist. des Veg. Foss., 1, p. 248,
tab. 90. Our American form does not agree perfectly with the
descriptions and figures of the European species. The leaflets
are narrower, the margins more reflexed, the nervation less
distinct, sometimes obsolete. Locality: St. John, Perry county,
Tllinois.

Alethopteris Massillonis, Sp. nov. Pl. 40, fig: 1-4. Frond

tripinnately divided; primary rachis about one inch thick, .

irregularly grooved and striated, smooth, with horizontal, alter-
nate branches; pinna diversely divided. In the superior one?
the naked rachis bears alternate long, linear, pointed pinne,
deeply pinnately lobed, with alternate, oval-lanceolate or oblong
obtuse pinnules, irregularly undulate on the margins, and sep-
arated to near the base, by a broad, flat or acute sinus. In the
inferior? primary pinnze, the narrow rachis is winged, or the
shorter secondary pinnae are pinnately divided into regular,

proportionally broader pinnules, becoming shorter in ascend- °

ing, and forming only regular, broad, alternate undulations
near the top of the pinne—fig. 3. The terminal pinnule is
lanceolate, acute, undulate, lobed at the base. Medial nerve

eee eee

ne

FOSSIL PLANTS. 439

broad, ascending to at least three-fourths of the leaflets; ner-
vules oblique, deeply marked, all forking twice.

This species appears distinct from all the others of this
genus. It has some relation to the former and also to Alethop-
teris Dournardii, Brgt., especially by its pointed terminal leaf-
let, but it is different from both by the nervation, the size and
the form of this terminal leaflet. As in Pteris aquilina of our
time, part of the pinnz, probably the lower ones, have a
winged rachis, and the tertiary divisions become insensibly
shorter in ascending to the point of the pinna, which is thus
only pinnately divided near the top.

The species is abundantly found at Massillon, Ohio, in the
shales of No.1 B coal. I have never seen it elsewhere, except
once among the specimens sent by Mr. Even from Mazon creek.
Though this last specimen has its nervation somewhat obsolete,
it evidently belongs to this species. It is copied fig.4. A large
specimen, showing the common broad rachis and horizontal
branches, as described above, is not figured here.

Alethopteris Owenu, Lsqx. Geol. Rep. of Arkansas, vol. 2, p.
309, pl. 2, fig. 1 and la. A small indistinct fragment from
Mazon creek, is referred with doubt to this species.

Alethopteris Serli, Brgt.. Hist. des Veg. Foss., 1, p. 292, tab.
85. Abounds at Murphysboro, Jackson county, Illinois.

Alethopteris crenulata, Gopp.

Pecopteris crenulata, Brgt. Hist. des Veg. Foss., 1, p. 500, tab.

87, fig. 1. This species is extremely rare. M. Brongniart saw

and figured only a small branch of it, resembling that of our
fig. 4. Though still incomplete, the specimens figured on our
plate 39, fig. 2, 3 and 4, evidently show that this species is a
true Alethopteris, of large size, at least bipinnately, but more
probably tripinnately divided, with a punctulate and irregu-
larly striated rachis. In all our specimens the pinnules are
ovate, obtuse, regularly divided to near the rachis, separated
by a flat sinus, and thus leaving a narrow margin along the

440 PALEONTOLOGY OF ILLINOIS.

tertiary rachis.. In the specimens fig 2 and 4, the derm of the
leaflets is gone, and the nervation is perfectly distinct. All
the veins are oblique on the narrow midrib, arched and forked
once. In the large specimen, fig. 3, the derm of the leaflets is
preserved, and the indistinct veins appear simple and straight,
just as they are figured by M. Brongniart. All our specimens
are from Mazon creek, Grundy county. Coal No. 3.

Alethopteris stellata, Sp. nov. Pl. 34, fig. 4 and 4a. Frond
pinnate; pinnee oblique, linear, obtuse or abruptly cut; mar-
gins undulate, decurrent along the medial nerve or common
rachis; primary and secondary veins pinnately branching;
veinlets simple, alternate, oblique, slightly arched, bearing at
their extremities, just on the border of the somewhat elevated
margin, a round, stellate, six-lobed sporange. I have figured
all that can be seen of this remarkable species, which should
perhaps be referred to the genus Asterocarpus, Gopp. It ap-
pears, nevertheless, more nearly related to Alethopteris cristata,
Gutb., from which it is essentially different by the decurrent
margin of the leaflets. The medial primary nerve is strong
enough, but the secondary veins are thin, straight, and ascend-
ing, without thinning, to the top of the leaflets. Fig. 4a and
4 6 show the enlarged form of the sporanges as distinctly as it
is possible to see it with a glass. Locality and position: same
as last.

Genus CA.LuipTeris, Brgt. Frond bi or tripinnatifid; pin-
nee long, decurrent on the common rachis; pinnules continu-
ous, oblique, obovate or oblanceolate, united and decurrent at
the base; medial nerve thick, oblique or arched; secondary
nerves oblique, arched, dichotomous.

Callipteris Sullivantu, Lsqx. Pl. 38, fig. 1, and Geol. Rep.
of Penn., p. 866, tab. 5, fig. 13. This fine species was first
found at Shamokin, in the Anthracite coal fields of Pennsyl-
vania, in poor and broken specimens. From the numerous

1
;
!
i

ae

FOSSIL PLANTS. 44]

specimens found at Colchester, in the roof shales of coal No. 3,
the species has been more satisfactorily studied. Frond appa-
rently very large, and at least bipinnate; secondary pinnz
lanceolate, with a broad canaliculate rachis; pinnules alternate,
oblique, obovate or oblong, nearly contiguous, slightly decur-
rent by the base, and united together with a slightly obtuse
sinus; medial nerve broad and flat, abruptly disappearing above
the middle of the leaflets; veins obliquely arched, slender,
close, mostly twice forked.

Genus Pecorreris, Brgt. Frond bi or tripinnate, or many
times pinnately divided; pinnules ordinarily enlarged, united
together or decurrent at the base; veins oblique on the medial
well marked nerve, simple or forking; fruit dots round, ordi-
narily two ranked. The genus Pecopteris may be, and has
already been, subdivided, but this separation is based on such
variable or indistinct characters (the fructification) that it is
scarcely possible to attempt it, or to admit it, with the mate-
rials now at hand.

Pecopteris pteroides, Brgt. Hist. des Veg. Foss., 1, p. 329, tab.
99, fig. 1. Specimen in the State Cabinet, from Mazon creek.
It is the only one which I have seen from the Coal Measures
of America. Coal No. 3.

Pecopteris Cistu, Brgt. Hist. des Veg. Foss., 1, p. 830, tab.
106, fig. 1 and 2. This specimen, also from Mazon creek, has
the nervation and the form of the leaflets of Pecopteris abbre-
viata, Brgt., and could be referred to this species, but for the
very narrow rachis. It is probably the upper part of a frond
of Pecopteris Cistit.

Pecopteris polymorpha, Bret. Hist. des Veg. Foss., 1, p. 331
and 332, tab. 13. (Pecopteris Miltoni, Brgt., Loc. Cit.) It
abounds in fine specimens on the Wabash river, below New
Harmony, Indiana, and also at Grayville, Illinois; Upper Coal

Measures.
6 Oor. 9, 1866.

442 PALEONTOLOGY OF ILLINOIS.

Pecopteris velutina, Lsqx. Geol. Report Penn., p. 866, tab.
12, fig. 3 and 38a. A rare species. The locality of the speci-
men in the State Cabinet is unknown.

Pecopteris villosa, Brgt. Hist. des Veg. Foss., 1, p. 316, tab.
104, fig. 8. Abounds in the roof shales of coal No. 3, at St.
John, Crooked creek, Carlinville, ete.

Pecopterts oreopteredis, Brgt. Hist. des Veg. Foss., 1, p. 317,
tab. 104, fig. 2; tab. 106, fig. l to 3. Found at Murphysboro
and at Mazon creek, Grundy county.

Pecopteris arborescens, Brgt. Hist. des Veg. Foss., 1, p. 310,
tab..101. Locality: Mazon creek, Grundy county. Rare in
Tllinois.

Pecopteris lepidorrhachis, Brgt. Hist. des Veg. Foss., 1, p.
313, tab. 103, fig. 1 to 5. Our species is exactly conformable
with the description and figures of M. Brongniart. The rachis
is squamose, the leaflets sometimes a little broader. It is eyi-
dently distinct from the former species. Locality: Mazon
creek, Grundy county. Coal No. 3.

Pecopteris unita, Brgt. Hist. des Veg. Foss., 1, p. 342, tab.
116, fig. 1 to 5. Abundant at Duquoin, Colchester, Mazon
creek, etc.

Pecopteris plumosa, Brgt. Hist. des Veg. Foss., 1, p. 348, tab.

121 and 122, and Pecopteris acuta, Brgt., Loc. Cit., 1, p. 350, -

tab. 119. Same distribution as the former species.

Pecopteris nervosa, Brgt. Hist. des Veg. Foss., 1, p. 297, tab.
94. The State Cabinet has only a small specimen from Mur-
physboro, Jackson county. Lower Coal Measures.

Pecopteris callosa, Sp. nov. Pl. 35, fig. 1 to 5. Frond bi or

tripinnatifid. Pinnee linear-lanceolate, obtuse, with a broad _

unequally lobed, deltoid-terminal leaflet; pinnules oblong or
ovate-lanceolate, or broadly oval, narrowed at the base, and
somewhat decurrent on the winged rachis, distinct, sometimes

.

FOSSIL PLANTS. 443

distant, with more or less undulated or pinnately round-lobed
margins; medial nerve flat and smooth. The epidermis of the |
leaflets is thick, smooth, and the veinlets obsolete—appear
generally as marked fig. la. Fig. 2a represents the only
leaflet where I could distinctly see the vems. They are pin-
nately branching from the medial nerve, arched oblique, fork-
ing once below the middle. Found at Murphysboro, in small
specimens. Lower Coal Measures. .

Pecopteris Newberryi, Lsqx. Sphenopteris Newberryi, Lsqx.,
Geol. Report of Penn., p. 862, tab. 9, fig. 4. Locality: Mazon
creek. Small specimen. Coal No. 3.

Pecopteris Murrayana? Brgt. Hist. des Veg. Foss., 1, p. 358,
tab. 26, fig. 1 to 5. A small specimen from Mazon creek, and
a large one from Newport, R. I., have all the characters of this
species of the Oolite of Europe. M. Brongniart already re-
marks, in his examination of this species, that one species
apparently identical with it is found in the Coal Measures of
France. A small specimen also from Mazon creek, is referable
by the form of the leaflets to Pecopteris cherophylloides, Brgt.,
Hist. des Veg. Foss., 1, p. 357, tab.. 125, fig. 1 and 2, but the
nervation is indistinct.

SECOND DIVISION.—LEAVES OF UNCERTAIN OR UNKNOWN AFFINITIES.

Genus Corpaites, Ung. Stem erect, ringed by the persist-
ent base of the leaves; leaves simple, half embracing the stem,
long, linear, sometimes obovate, one to two inches broad; veins
thin, parallel, equal or rarely forking. .

Cordaites borassifolia, Ung. Abounds in the roof shales of
the coal strata, presenting various forms which probably belong
to different species. The long, narrow, entire leaves resemble
those of some Palms. Some of the numerous rootlets found
in the Coal Measures have been referred to this genus by hy-

444 PALEONTOLOGY OF ILLINOIS.

pothetical induction. Locality: Murphysboro, St. John’s, ete
Lower Coal Measures.

Genus SpHENOPHYLLUM, Brgt. Stems articulate, branching
from the articulations; leaves verticillate by six to twelve,
wedge-shaped, truncate at the top, either bilobate, or dentate,
or furcate; nerves ascending from the base, equal, forking.

Sphenophyllum Schlotheimii, Brgt. Prod., p. 68, is not rare
at Colchester and Duquoin. Obval No. 3.

Sphenophyllum emarginatum, Brgt. Prod.,p.61. Generally
found with the last.

Genus ANNULARIA, Sternb. Stems slender, articulate, branch-
ing from under the base of the leaves; leaves verticillate
around the articulations, united at the base, entire, generally
obtuse, oblanceolate, single nerved, of unequal length.

Annularia longifolia, Brgt. Prod.,p. 156. Especially found
in connection with coal No. 3 and 4. Mazon creek, Grundy
county, Illinois.

Annularia Sphenophylloides, Ung. Is found with the former,
also at Murphysboro, Jackson county.

Genus ASTEROPHYLLITES. Stems articulate, with opposite
branches, and leaves at the articulations; leaves numerous,
verticillate, slightly united at the base, of equal length and
size, linear acute, marked with a medial nerve. Inflorescence
from ear-like receptacles at the end of the branches or sessile
on the stems, apparently dioecious.

Asterophyllites longifolius? Brgt. Prod., p. 159. Leaves sub-
ulate, about three inches long, straight. The specimen in the
State Cabinet is from Mazon creek, Grundy county, and indis-
tinct. It may belong to Asterophyllites rigida, Brgt. Coal
No. 3.

Asterophyllites equisetiformis, Bret. Prod., p. 159. Locality:
Duquoin, Perry county. Coal No. 3.

FOSSIL PLANTS. 445

Asterophyllites subleevis, Lsqgx. Geol. Rept. of Penna., p. 851,
tab. 1, fig. 3. A few small specimens from Mazon creek.

Asterophyllties lanceolatus, Lsqx. Geol. Rept. of Penna., p.
852. Mazon creek, Grundy county. Coal No. 3.

THIRD DIVISION.—STEMS OF UNCERTAIN OR UNKNOWN AFFINITIES.

Genus CALAMITES, Suck. Stems cylindrical, hollow, articu-
lated, striated lengthwise; furrows or striz either alternating
or converging at the articulations; leaves whorled, encircling
the stem at the articulations like an open sheath; ramification
regular or irregular from the articulations; elevated scars or
tubercles marked above or below the point of attachment of
the leaves.

Calamites Suckowti, Brgt. Hist. des Veg. Foss., 1, p. 124, tab.
15, fig. 1-6. Variable, and found at various situations. Carmi,
Wabash river. Locality: Upper Coal Measures.

Calamites ramosus, Bret. Hist. des Veg. Foss., 1, p. 127, tab.
17, fig. 5 and 6. Locality: Duquoin and Murphysboro.

Calamites cruciatus, Sternb. Vers., 1-4, p. 27, tab. 49, fig. 5.
Found at Duquoin.

Calamites cistit, Bret. Hist. des Veg. Foss., 1, p. 129, tab. 20.
Some specimens of the State Cabinet are from Grayville; some
have no marked locality.

Calamites pachyderma, Brgt. Hist. des Veg. Foss., 1, p. 1382,
tab. 22. There is in the State Cabinet a single specimen,
without marked locality. This species is always found within
or below the Millstone-grit or Conglomerate formation.

Calamites bistriatus, Lsqx. Geol. Rept. of Penna., p. 850, tab.
2, fig. 1. A specimen in the State Cabinet. Locality unknown.

Calamites approximatus, Brgt. Hist. des Veg Foss., 1, p. 134,
tab. 24, fig. 7 and 8. Not rare in Illinois. Carmi, Springfield,
Duquoin, etc. Upper Coal Measures.

446 PALEONTOLOGY OF ILLINOIS.

Genus ArtisiA, Sternb. Woody cylinders, apparently a
central pith, narrowly transversely ribbed, referred to Lomato-
floyos, Sternb., by Corda, to Conifers by some authors, and to
Calamites by some others.

Artisia transversa, Sternb. Specimens in the State Cabinet
from Grayville, Upper Coal Measures. I have in my posses-
sion some of these woody cylinders, about two inches in diame-
ter, somewhat compressed, exhibiting transversal ribs on one
side and longitudinal strie, just like those of Calamites, on the
other.

FOURTH DIVISION.—BRANCHES, STEMS AND FRUITS OF LYCOPODIACHKA.

Genus SELAGINITES, Bret. Stems dichotomous; -leaves small,
numerous, imbricated, sometimes enlarged at the base, scarcely
leaving any visible scars.

Selaginites uncinnatus, Sp. nov. Pl. 41, fig. 3. The only
specimen seen of this species is in the State Cabinet. I found
it at Colchester, on a broken slab of roof shale, where nothing
more can.be seen but what I have figured. It evidently repre-
sents a plant of the Lycopodiacee, with a slender, irregu-
lar forking stem, covered with short, acicular, numerous leaves,
mostly perpendicular to the stem, apparently not enlarged at
the base. On the branches the leaves appear shorter, more
erect and imbricated. The small and latest branches, in their
unfolding, have the same spiral disposition as some Lycopodia-
cee and the Ferns. This species is distantly related to Selagi-
nites Erdmanni, Germ. Coal No. 3.

Selagunites cavifolius, Lsqx. Lycopodites cavifolius, Lsqx.
Geol. Rept. of Ky., vol. 4, p. 437, tab. 4, fig. 4 and 4a, ined.
Small specimens from Colchester. Coal No. 3.

Selaginites crassus, Sp. nov. Pl. 39, fig.8. Stem thick, ap-
parently creeping, dichotomous, with short, thick branches,

——

FOSSIL PLANTS. 447

covered with densely imbricated oval, concave, somewhat
pointed leaves. It differs from the former by the shorter, less
concave leaves and short branches. Mazon creek; a small
specimen. Same position as last.

Genus Lycopopitss, Brgt. Branches pinnately divided and
continuous; leaves either placed all around the stem or dis-
tichous, in opposite series, scarcely leaving distinct cicatrices.

Lycopodites asterophyllitefolius, Sp. ndv. Pl. 87, fig. 8. The
two branches figured are apparently from the same stem. The
long, linear, pointed leaves, placed all around the slender
branches are generally curved either upward or backward,
sometimes reflexed from the middle, apparently marked by a
medial nerve, thus resembling the leaves of Asterophyllites.
The scars left on the branches are only irregular points, with-
out any trace of a peculiar form. The leaves are apparently
sessile by their whole not enlarged base; the medial nerve is
scarcely marked. These branches could be considered as
belonging to some primeval species of coniferous trees, rather
than to Lycopodiacee. 'The communication of this remarkable
species is due to Mr. Joseph Even, who found it in an iron
nodule at Mazon creek. Position same as last.

Genus SrigmariA, Brgt. Stems creeping or floating, horizon-
tal, two to four inches in diameter, sometimes very long, fork-
ing or dichotomous, with a generally eccentric cylindrical pith;
bearing around it long, leaf-like, cylindrical appendages, simple
or rarely forking, slightly contracted at the base, with a single
central vascular fascicle. Scars or bolsters more or less regu-
larly placed in spiral, round, with a double ring, and a single
elevated point (mamilla) in the middle.

Stigmaria ficoides, Brgt. Mem. Hist. Nat., p. 82 and 88.
This species has the characters of the genus. It never —
_ theless shows various forms, which have generally been con-

448 PALEONTOLOGY OF ILLINOIS.

sidered as varieties, but which most probably are species.
Mentioning a few of them, we have:

var, undulata, Gopp. —_ the scars de pubeaeal by undulate
ribs.

var. reticulata, Gopp. With a reticulated surface.

var. stellata, Gopp. With the scars surrounded by regular
wrinkles, resembling the rays of a star.

The species is generally and abundantly found in the whole
thickness of our Coal Measures. Beautiful specimens of the
three varieties enumerated above, found in Pope county, under
the upper Archimedes limestone, are preserved in the State
Cabinet, together with Stigmaria anabathra, Corda, Stigmaria
minor, Gopp., and Stigmaria umbonata, Lsqx., which can not
be separated from this Stigmaria ficoides, unless the other
varieties are admitted as true species.

Stigmaria Evenii, Lsqx. Pl. 39, fig. 9. This speces is not
comparable to any other form of this genus. It is remarkable,
indeed, for the great irregularity of position of the scars, their
generally small and at the same time very variable size, some-
times as small as a point. They are then approached by two
together, while the largest are isolated. Generally they are
separated by short undulate ribs, somewhat like those of Stig-
maria undulata, Gopp., but less regular and shorter. The
central point is obsolete, and sometimes entirely undiscernable.
Found at Mazon creek, by Mr. Jos. Even. Coal No. 3.

Genus SicituariA, Bret. Stem large, tree-like or erect,
marked on its surface with parallel ribs or reticulated in dif
ferent directions, even nearly smooth, impressed with the cica-
trices of deciduous leaves, placed around the stems in spiral
or quincuncial order; cicatrices disciform, oblong, or round,
with mostly angular sides, the upper part emarginate, marked
in the middle by scars of vessels, horizontally placed in three,
sometimes two, rarely simple.

FOSSIL PLANTS. 449

Some authors have attempted to divide the genus Sigillaria,
and also the genus Lepidodendron, into a number of different
genera; but this attempt appears to be a failure, from the
great unreliability of the characters considered as spttific.
Some of our American types might authorize such a division
more appropriately than any European species. Nevertheless
- such divisions can not be proposed in a report where all the
necessary materials can not be brought together and examined
in detail.

Sigillaria monostigna, Sp. nov. Pl. 42, fig 1-5. A very

fine and remarkable species. In its corticated state, the scars
(fig. la and fig. 3) are broadly rhomboidal, acute at the sides,
marked near the obtuse upper angle by a small, round, vascular
scar and a central point, resembling, by its general form, that
of a Stigmaria, but much smaller. The surface between the
cicatrices is striated by straight, parallel, narrow lines, running
in the direction of the four axes or perpendicular to the four
sides of the rhomboidal scar. These scars bear on both sides,
from the corners of their acute angles, inwardly curved appen-
dages like those of some species of Lepidodendron. In the
decorticated state, the striz of the surface are obliterated and
the scars have various forms, changing from rhomboidal to
oval, then to arched lines or to round points only, representing
the vascular scars, which are generally preserved.. The pas-
sage from one form to the other can easily be followed on the
figures. Fig. 4 represents a specimen apparently deprived of
the whole thickness of the bark. It shows the lower side of a
thin plate of shale, about one-eighth of an inch thick, which
bears upon its upper surface corresponding scars like those of
fig. 5. Goldenberg, in the second Liv. of his Flora Sarreepon-
tana, etc., has recently published a new species—Sigillaria
rimosa, Gold.—which is somewhat related to our American
species. ‘The general form of the scars, even of those of fig. 4,
is much alike; but the essential character, viz: the position
—d7 Oor. 10, 1866,

&

450 PALEONTOLOGY OF ILLINOIS.

and the form of the vascular scars is totally different. The
surface is also striated in another manner. Our species repre-
sents a new type, till now peculiar to America, and far more
different from the true Sigillarie than is the genus Syrigoden-
dron, Bret. . Locality: Colchester.

Sigillaria sculpta, Lsqx. Geol. Rept. Penna., p. 871, tab. 13,
fig. 3. Locality: Duquoin, Perry county.

Sigillaria Menardi, Brgt. Hist. des Veg. Foss., 1, p. 430, tab.
158, fig. 5, 6. The figured specimen of our pl. 43 was found
by myself at Colchester, and belongs to the State Cabinet, at
Springfield. It shows the scars of the leaves and the broad
round cicatrix of a branch. This cicatrix makes of our species
a true Ulodendron, nearly related, indeed, to Ulodendron punc-
tatum, Sternb., while the scars of the leaves show it to be a
true Sigillaria. I can not see any difference between this
species and Sigillaria Menardi, Brgt. The outline of the scars,
as it is seen from the figure, is very variable, passing from
rhomboidal, pointed at both ends, to conical-obtuse, then to
enlarged-polygonal, and even to acute-hexagonal. The differ-
ences are easily accounted for by a difference of direction of
the angles, according to an irregular compression of the sides,
following the place occupied by the base of the leaves. The
branch scar is broadly oval or nearly round, bordered by a
small margin, narrowly and irregularly wrinkled, with a small
axis, marked by a deep cavity.

The specimen figured here is of true scientific interest, first,
in showing the great variations of the leaf-scars, even on a sur-
face of small extent; secondly, by proving that the genus
Ulodendron, as it has been established, represents only
a peculiar state of some species of Lepidodendron—or rather,
that some species of the genus Sigillaria, belonging to the sec-
tion of the Levodermarie (without ribs), are more nearly related
to the genus Lepidodendron than to the costate Sigillaria.

FOSSIL PLANTS. 451

They form an intermediate genus which, difficult to limit as it
is now, will become separated when our American oe
have been more fully collected and studied.

Sigillaria Brardu, Brgt. Hist. des Veg. Foss., 1, p. 431, tab.
158, fig. 4. Colchester and Duquoin.

Sigillaria tessellata, Brgt. Hist. des Veg. Foss., 1,.p.436, tab.
157, fig. 1, and tab. 162, fig. 1-4. Found at Colchester.

—s- Sigillaria intermedia, Brgt. Hist. des Veg. Foss., 1, p. 474,
tab. 165, fig. 1. The State Cabinet has two specimens, from
Carmi, White county. Upper Coal Measures.

Sigillaria Yardleyi, Lsqx. Cat. of Foss., pl. —, p. 17, tab. 2,
fig. 4. Locality: Big Vermilion river.

Sigilaria reniformis, Brgt. Hist. des Veg. Foss., 1, p. 470,
tab. 142. A common species. The specimen in the State
Cabinet is without indication of locality.

Genus SYRIGODENDRON, Brgt. Stems furrowed; ribs equal,
parallel, narrow, convex, bearing on the corticated surface of
the ribs, small, round or curved mammille, without any vascu-
lar scars.

Syrigodendron pachyderma, Brgt. Hist. des Veg. Foss., 1, p.
479, tab. 66, fig, 1. A specimen in the State Cabinet without
indication of locality.

Genus LrpipopEnpRon, Sternb. Stems of various size, some-
times very large and long, with a dichotomous ramification or
forking in ascending; and bearing linear, grass-like leaves on
the young branches; surface of the stem marked by the im-
pressions or cicatrices left at the base of the leaves, or at their
point of attachment; cicatrices rhomboidal or oval, acute at
both ends, sometimes deltoid, marked in the middle or in the
upper part by triangular or rhomboidal vascular scars. These
are ordinarily marked in the middle by three points; some-
times they have, descending from both the angular sides, two

452 PALEONTOLOGY OF ILLINOIS.

arched lines, named appendages, and just under the scars, near
the middle, two oval, slightly diverging impressions, named
tubercles. The vascular scars are also sometimes overtopped
by triangular, trapezoidal or pointed marks, named, the crown.
According to the form of the cicatrices, and the form and posi-
tion of the scars, this genus has been divided into four sections: |
Lepidodendron, Sagenavia, Aspidaria and Bergeria, considered
by some authors as true genera. But as some of our American
species belong at the same time to at least two of these divis-
ions, according to their corticated and decorticated appearance,
I have not yet found the advantage of preserving any of them
for a classification.

Lepidodendron diplotegioides, Lsqx. Pl. 49, fig. 2, and Geol.
Report of Ark., tab. 4, fig. 2. Stem apparently of small size;
cicatrices rhomboidal, obtuse on both sides, acute at both ends,
margin broad and smooth; vascular scars elliptical, enlarged
and acute at the sides, arched above, obtuse below, marked in
the middle by three oval, close, nearly continuous points;
appendages and tubercles none; crown an irregular oval point;
medial line scarcely marked by a few deep wrinkles. In the
decorticated state the cicatrices are exactly rhomboidal, some-
what inflated, marked in the middle by a straight line, or an
elongated, deep point. Our specimen, which I found at Col-
chester, and which belongs to the State Cabinet, completes the
small decorticated specimen from the lower coal of Arkansas,
from which the species was established. It proves at the same
time that some species of Lepidodendron ascend from the coal
under the Conglomerate, as high as our coal No. 3.

Lepidodendron Worthenti, Sp. nov. Pl. 44, fig. 4 and 5.
Stem slender; cicatrices oblanceolate, narrowed and continu-
ous at the base, transversely much wrinkled, bordered with a
narrow, smooth margin. Vascular scars as broad as the cica-
trices, acute at both sides, emarginate above, very obtuse,

FOSSIL PLANTS. 48

arched in the lower part, marked in the middle by three equal
small points, and overtopped by a pointed crown; tubercles
none, appendages marginal. A fine species found at Murphys-
boro, Jackson county. Coal No. 1 B.

Lepidodendron turbinatum, Sp. nov. Pl. 44, fig. 6. Cica-
.trices very inflated, obovate, obtuse at both ends, rugose near
the base, encircled with a high, smooth, obtuse, broad margin ;
vascular scars obscure, placed at the top of the cicatrices, broad,
acute on the sides, slightly emarginate above, very obtuse
below, marked with three points, without tubercules or append-
ages. Locality: Carroll’s place, Pope county; Chester group.

Lepidodendron costatum, Sp. nov. Pl. 44, fig. 7. Cicatrices
scarcely marked if at all; apparently oval, wrinkled, flat, sepa-
rated by a rugose half an inch broad, straight contiguous mar-
gin, resembling the intermediate ribs of a Sigillaria. Vascular
scars deeply and broadly notched above, arched below, angular
on the sides, marked in the middle by two large external points,
and a smaller medial one; appendages long and well marked;
crown a large oval point. A beautiful species, found also at
Carroll’s place, under the Upper Archimedes limestone. Ches-
ter group.

I was at first inclined to consider the three last named spe-
cies as representing different forms of the same, at different
stages of the growth of the plant; but there is too much differ-
ence in the form of the cicatrices. Should other specimens of
these species support the first supposition, the two last forms
may be described as varieties, and the specific name, Lepido-
dendron Worthen, preserved. Itis but just that such a fine
species bears the name of Prof. A. H. Worthen, who has done
so much for the Paleontology of the West by his indefatiga-
ble researches.

Lepidodendron obscurum, Sp. nov. Pl. 44, fig. 1 to 3. Cica-
trices flat, rhomboidal, obscurely marked, distant and separated
by longitudinal, deep, slightly undulate striz, becoming more

454 PALEONTOLOGY OF ILLINOIS.

and more marked, and forming deep furrows in the old part o
the trees. Vascular scars central, round or oval, irregular,
without appendages and tubercles. This species is from Car-
roll’s place, like the former. It is distantly related to Lepido-
dendron Carpentiert, Gopp., and like both the following species
belongs to the section of the Aspidarie. Chester group.

Lepidodendron radicans, Sp. nov. Pl. 46, fig. 1. Cicatrices
large, irregularly oval, very obtuse on the sides, pointed or
somewhat narrowed and continuous at both ends; vascular
scars central, generally eccentrical on one side of the cicatrices,
obliterated by irregular, deep, large striz or narrow ribs, appa-
rently the marks of flattened rootlets. The species has some
relation with Caulopteris macrodiscus, Sternb., but in one speci-
men the scars are continuous and have the spiral portion of
the cicatrices of Lepidodendron. I found this specimen at
Duquoin. It belongs to the State Cabinet.

Lepidodendron simplex, Sp. nov. Pl. 45, fig. 5. Cicatrices
narrowly elliptical, acuminate at both ends, continuous, sepa-
rated only by narrow, linear margins, entirely naked and
smooth; vascular scars central, rhomboidal, very obtuse above,
narrowed at the sides and also at the obtuse base; marked by
three equal points. No traces of appendages, or tubercles, or
crown.

This species is nearly related to Lepidodendron rimosum,
Sternb., differing essentially by the cicatrices being closely
placed, not separated by broad, wrinkled margins, and the scars
obtuse (not angular). The leaves of this species are narrow,
as seen in the figure, of the same breadth as the leaves of Lepi-
dodendron vimosum. I have figured one leaf as it appears
attached to the stem; but this appearance might be deceptive.
The leaves, fig. 6 and 7, also leaves of another species of Lepi-
dodendron, are abundantly found in the shales of the same
coal bank.

FOSSIL PLANTS. 455

» Itis remarkable that Prof. Geinitz, in his Coal Flora (Vers-
teinerungen) of Saxony, describes under the name of Lepidos-
trobus variabilis, a species nearly related to our Lepidostrobus
princeps, and considers it as a cone of Lepidodendron rimosum.
Lepidostrobus princeps could be thus considered as a cone of
Lepidodendron simplex. But at Colchester, where the specimen
of Lepidodendron was found, there are no remains of Lepidos-
trobus; and this last species is in plenty at Duquoin, where no
specimen of Lepidodendron was found. It is well to remark,
nevertheless, that both Duquoin and Colchester coal banks are
placed at the same geological horizon. Coal No. 3.

A number of specimens of other species of Lepidodendron,
some apparently new, are preserved in the State Cabinet at
Springfield, mostly from Pope county, but most of them are too
much broken and obliterated for determination. Among the
species already known, there is in the cabinet the following:

Lepidodendron clypeatum, Lsqx. Geol. Report Penn., p. 875,
tab. 15, fig. 5, and tab. 16, fig. 7. Locality: Rock Island
county.

Lepidodendron obovatum, Sternb. Vers., 1, p. 10, tab. 6, fig.
1. Locality: Same as last.

Lepidodendron Veltheimianum, Sternb. Vers., 1-4, p. 12,
tab. 52, fig. 2. Carroll’s place, Pope county; Chester group.

One specimen from the same place is referable with doubt to
Lepidodendron gracile, Brgt., and another to Lepidodendron ele-
gans, Bret.

Genus Lepipostrosus, Bret. Cones or catkins of species of
Lepidodendron, formed by winged sporanges perpendicularly
attached all around a common axis, with the wings or blades
(Lepidophyllum) upraised and imbricated.

Lepidostrobus princeps, Sp. nov. Tab. 45, fig. 1 to 4. Cone
large, cylindrical, about one foot long, or more; blades sagit-
tate at the base, lanceolate, taper-pointed, marked with a broad

456 PALEONTOLOGY OF ILLINOIS.

nerve in the middle; pedicel of the sporanges oblanceolate,
slightly obtuse, attached to a slender axis. This species, as it
was remarked above, is related to Lepidostrobus variabilis, fig-
ured and described by Geinitz; but the blades of ours are
broader, the pedicels bearing sporanges longer and the axis
narrower. The name variabilis was given to the Huropean
species on account of the great variety in the size of the cat-
kins. The American species appears always large—at least,
all the numerous specimens collected at Duquoin are as large
as fig. 1, which represents only part of a cone, and is already
more than one foot long. Fig. 2 and 3 show the transversal
sections of a catkin; fig. 4, a detached blade with its pedicel.

Lepidostrobus hastifolius, Sp. nov. Cone about one inch thick;
scales densely imbricated, with the blade open, nearly horizon-
tal, at least near the base; blade short, enlarged at the base
into two acute, angular, diverging points, ovate-lanceolate,
somewhat obtuse at the summit; pedicel of the sporange nar-
row, linear, acute, a little enlarged above.

This is the cone whose blade I have named Lepidophyllum
hastatum, Geol. Rept. Penn., p. 876, tab. 17, fig. 7. The pre-
served part of the cone is about three inches long, but it is
broken and its whole length is not known. Locality: Mazon
creek, Grundy county. Coal No. 3.

Genus Lepipopnytium, Bret. This genus is preserved for
the classification of the fruit-bearing leaves or bladed sporanges
- of the Lepidostrobi, for as far as they are known only in their
isolated state, and have not been seen attached to a common
axis.

Lepidophyllum lanceolatum, Bret. Figured and described in
the Geol. Report of Penn., p. 875, pl. 17, fig. 1. :

Lepidophyllum majus, Bret. Prod., p. 87. Specimens of this

and the former species are in the State Cabinet of Springfield.
Locality unknown.

FOSSIL PLANTS. 457

Lepidophyllum auriculatum, Sp. nov. Pl. 36, fig. 6.. Blade
long, lanceolate, pointed, a littleenlarged in the middle, mark-
ed by a broad, medial nerve, bearing at the base two small,
round auricles; pedicel of the sporanges thick, ovate, enlarged
under the blade, a little obtuse at the base. Found at Neely-
ville, Morgan county.

Genus Lermopuioyros, Brgt. Stem cylindrical, bark covered
with scales, or by the persistent base of decayed leaves, and
marked with broad, rhomboidal scars. The relations of this
genus are not well ascertained.

Lepidophloyos obcordatum, Sp. nov. Pl. 41, fig. 1 and 2.
Scales lanceolate, truncate, inflated in the middle; scars of the
decorticated surface, cordiform, obtuse, overtopped by button-
like, round, small crowns, corresponding with the base of the
scales. The specimen originally showed the under part of the
bark; but by removing accidentally the coat of clay upon
which the impressions are marked, the scales were discovered.
(Fig. 1, specimen from Duquoin.) Fig. 2 is from a smaller
specimen found at Colchester—coal No. 3. In this one the scars
have nearly the same general outline, dilated on both sides,
obtuse below, showing above a vascular scar about of the same
form, marked by three horizontal points.

Genus Knorri, Sternb.and Gopp. Stems tree-like, bearing
basilar conical remains of nearly imbricated, or closely and
spirally placed leaves. —

Knorria imbricata, Sternb. Vers., 1, p. 87, Chester group.

FIFTH DIVISION.—STEMS OF FERN TREES.

Genus Mucapuytum, Artis. Stem tree-like, apparently large,
furrowed, dotted, marked by large scars. of a horse-shoe figure,
left by the base of the petioles of large fronds and placed in
two or more parallel rows. This definition is somewhat modi-

JO Nov. 1, 18663

458 ' “-~PALMONTOLOGY OF ILLINOIS.

fied from the author’s. Our American specimens evidently
. prove that the scars were left by the petioles of large fronds,
and not of branches. This genus is thus, as Prof. Geinitz has
already remarked, nearly related to Caulopteris. If the name
of Megaphytwm should be appropriated to represent stems bear-
ing scars of undeveloped or adventive branches, following Gol-
enberg’s description of his Megaphytum giganteum, a new

genus should be established for the classification of our species.

Megaphytum protuberans, Sp. nov. Pl. 47, fig. 1 and 2.
Scars convex, elevated, square-oval, slightly emargenate above,
marked in the upper part by vascular lines of nearly the form
of a reversed horse-shoe; stem irregularly striated and pointed;
points of various size and placed without apparent order. Fig.

‘1 represents a large specimen one-third of natural size; fig. 2
two scars of natural size. It is a beautiful species found in
the sandstone under the upper Chester limestone at Carroll’s
place, Pope county.

Megaphytum McLayi, Sp. nov. Pl. 48, fig. 1. Scars very
large, nearly contiguous, flattened, surrounded by a broad,
smooth margin, broadly square, somewhat rounded, separated
in two by a broad, irregular rib, and marked on both sides by
the irregular auriculate impressions of the ducts. I have seen
of this remarkable species another specimen similar to the one
figured here, and having four scars still larger than these. It
was found at St. John, by Mr. John McLay, to whom the spe-
cies is dedicated, and who fell at the battle of Shiloh, in Ten-
nessee, in defending the cause of his adopted country and
human liberty.

Genus CAuLopreris, Lindley and Hutt. Stems tree-like,
bearing on the surface large, oval, peltate scars, showing the
point of insertion of petioles of large fronds of ferns; scars dis-
tant, disposed in spiral or in a quincuncial order, surrounded
by a broad, simple or double margin (annulus) diversely marked
by oval or curved above, and horn-like vascular impressions.

FOSSIL PLANTS. 459

This definition brings together the genera Cauwlopteris, Stemma-
topteris and Ptychopteris of Corda, for reasons which cannot be
discussed here. Species of this genus are rarely found in the
Coal Measures. The whole coal flora of Europe has a single
species of the section Stemmatopteris, and three or four species
of the true Caulopteris. The coal flora of the United States
already counts six species of Stemmatopteris, but none referable
to the section Cawlopteris.

Cawlopteris insignis, Sp. nov. Pl. 49, fig. 1. Scars very
large, exactly oval, bordered by a smooth, broad (about one
inch) annules. Vascular scars horse-shoe shaped, with the
internal branches descending nearly to the basal line, where
they unite in a point, forming a spatulate, pointed or beaked
medial rib, with two at first parallel and then diverging semi-
lunar appendages; surface smooth, except the rib which is
marked by irregular, deep points in its whole length, and in
the space between the appendages. The State Cabinet has two
specimens of this remarkable species, both from Duquoin.
Lower Coal Measures.

From the size of these scars it could be supposed that they
were from very large trees. But the marks of the petioles of
fern trees are comparatively large. The stem of the following
species is ten inches in circumference, and the size of the scars
is one-fourth of those of this species. Ifthe proportion in the
development of the stem was the same, the tree bearing this
cicatrix would have been only about 14 inches in diameter.

Caulopteris Worthenvi, Sp. nov. Pl. 50, fig. 1. Stems slen-
der, about three inches in diameter, somewhat compressed ;
scars distant, round at the base, narrowed, horse-shoe shaped
above, with converging branches; vascular scars of the same
form as the annules, marked near the base by a semi-lunar
obscure appendage. The specimen figured here is replaced
by sandstone. It appears to be decorticated; at least the sur-
face is perfectly smooth. The position of the scars is marked

460 PALMONTOLOGY OF ILLINOIS.

by the pointed lines, a, 8, ¢, fig. 1. The lower scar, a, is fig-

ured 10, and has a different form from the upper one, la.

The scars at 6 and c, fig. 1, are obsolete, scarcely visible, and
consequently the true disposition of the leaves is only supposed.
It appears to be nearly in one-fourth. Fig. Le is the cross sec-
tion of the stem, natural size. Found at Carmi, White county.

SIXTH DIVISION.—FRUITS OR NUTLETS.

Genus Triconocarpum, Bret. Fruit ovoid, three or six cos-
tate, generally marked at the point a attachment by a hexa-
gonal depression.

Trigonocarpum juglans, Sp. nov. Pl. 46, fig. 3. Fruit of ©

large size, about one inch and a half in diameter, nearly round,

apparently three ribbed; ribs elevated, suleate; surface nearly
smooth, slightly striated or marked by narrow, distant lines,
parallel to the ribs. The figure shows all that can be seen of
the preserved part of this fruit. Found in a piece of iron
shale at Murphysboro, Jackson county. Lower Coal Measures.

Trigonocarpum rostellatum, Sp. nov. Pl. 46, fig. 6. Fruit
oval, a little flattened, three ribbed only near the point, which
is curved in a short beak; lower part of the fruit round and
smooth. Locality: Grayville, White county. Upper Coal
Measures. |

Genus CARPOLITHES, Sternb. Wruits of various forms and
of doubtful affinity.

Carpolithes multistriatus,? Sternb. Pl. 46, fig. 2. I refer
this fruit with doubt to the species figured by Sternberg, Vers.,
vol. 2, tab. 39, fig. 1 and 2. The American form is longer,
more evidently pointed at the base, more obscurely ribbed. It
is oblong, nearly two inches long, apparently originally inclosed
in a large shell or woody envelope transformed into coal. It
is remarkable that in our fruit, as in figure 1 of Sternberg’s,
the envelope of coal matter appears to be extended above or

.

<

FOSSIL PLANTS. 461

around the fruit by a kind of frame looking like a part of a
destroyed envelope. Locality: Unknown. Specimens of the
true QO. multistriatus have been found at Colchester. They are
broader but shorter than this described form, and do not have
any trace of the coaly, envelope.

_ Carpolithes Jacksonensis, Sp. nov. PI. 46, fig.4. Fruit about
two inches long, one inch broad, ovate, oblong, pointed, marked
with six? elevated ribs. This species is not rare in coal No.1 B.
It may be, perhaps, referable to Carpolithes sulcatus, Sternb.,
though far different in general outline. Locality: Murphys-
boro, Jackson county. Lower Coal Measures.

Carpolithes cistula, Sp. nov. Pl. 46, fig. 5. (From a speci-
men in my cabinet, found at Murphysboro.) ‘This fruit,
which in general outline is about square-oblong, appears formed
of three parts: an outer, broad or thick envelope; a medial
one, apparently hard and thin, replaced in the specimen by a
thin coat of coaly matter; an inner kernel or fruit, elliptical,
inflated or convex, smooth and marked in the middle by an
irregular rib.

Carpolithes fasciculatus, Sp. nov. Pl. 46, fig. 7. Fruits gen-
erally flattened, smooth, oval, short-pedicelled, marked in the
middle by a short, narrow furrow. A common species, found
especially in the high coal. These fruits are generally three,
‘four or more together in close proximity, as if they had been
attached to a common pedicel or in bunches. I have never-
theless not been able to see them in a more evident connection
than in the specimen copied, fig. 7. Is plenty at Grayville,
White County; Upper Coal Measures.

SEVENTH DIVISION.—ROOTS OR ROOTLETS.

Genus PinnvxariA, Lindl. and Hutt. Irregularly branching
- filaments, of various forms and sizes, have been classed under
this name. One of them, with numerous thread-like, irregu-

s

462 PALEONTOLOGY OF ILLINOIS.

ar branches, Pinnularia capillacea, Lindl. and Hutt., is very
abundant in the coal shales, especially with coal No. 8. The
State Cabinet has numerous specimens of it.

It may not be out of place to mention here the remarkable
Gyromices ammonis,Gopp. PI. 38, fig. 6,66. A spiral, organized
body, which has been referred, by Prof. Goppert and other Ger-
man authors, to a species of fungus, found under or within the
coaly matter of some leaves and stems of the coal shales. This
species is abundant at Colchester with the remains of various
plants, under the leaves of Callipteris Sullivantu, Pecopteris,
Stigmaria, Oordaites, etc. Tt is true that these remains appear
sometimes within the coaly matter of the plants, or imbedded
in it, a cigscumstance which may have led the German Palzon-
tologists to consider the species as a fungus. But in most
instances, these small bodies have left their prints deeply
marked, or rather their casts, in the shales, under the coaly
matter of the leaves. Their substance was consequently hard.
It is thus easy to understand that if ever they lived under the
leaves or floating stems, the pressure has forced them some-
times within the softened substance of the leaves and stems, as
it_has forced them within the clay. I have examined many
specimens of this species under divers circumstances of posi-
tion, etc., and cannot consider them but as the small, thick
shells of an Annelid. Professor Dawson, of Montreal, who
examined this species a long time ago, has considered it in the
same light, and named it Spirorbis carbonarius. The shell
makes about two spiral turns, and is marked crosswise by
strong ribs, each separated by three or four thinner ones. Fig.
6 shows a cross section of the species. Fig 6 and 6a are en-
larged ten diameters.

ane F

FOSSIL PLANTS. 463

SUMMARY.

*

Only 120 species of fossil plants are named and described in

-the above enumeration.* Is not this number very small, and

shall we not admit at once that the fossil flora of the coal fields
of Illinois is extremely poor? Before coming to such a con-
clusion, and to arrive at a better understanding of the general
flora of our American coal fields, we had better, I think, com-
pare the distribution of the species of Illinois, in their differ-
ent genera, with those of Ohio and Pennsylvania, as far as
they were known when my catalogue of Fossil plants was
published in 1858. This is easily done in the following table:

‘stom
dg
sansoy

~ey30 ut saroads
‘oures

*arojaq
Oy} UT seroeds ssayy

GENERA.

*SIOUTI][T Ul saroads
jo aequinu ejoy Ay
*SIOUNTT] UT S910
-ads AOU Jo 1OQUITLNT
“III Ut punoy satoa
*SIOUTTTT TE pundg
jou pus endojEyR0
uw paysrqnd saroedg
jo iaqminu soy

paystqnd you

. Noeggerathia +
PO VCIOPUCHIS: acces success o0a0
MA NICMIU OULU ne sncectsincsaecladesse(sscsseiee once I
PONG ONO DUCE Seis dhs duasls staes son orecakisee once
CTV OMUCHI Shs swscacaaistdatccsceseencersieicees ct
SMEG pterisiencsescs se cacecsesbecccteeniccsecs
. Hymenophyllites
2 PUIG TIO) QUCINES endcconodounddcaenonceedoecaeeoan
. Callipteris.....
10. Pecopteris.....
11. Crematopteris
HVS COMOP CHOLES -accceutvocecerasscstsanconenes
MeseenS CHUAO DUCT Seccsckwoscesecoecieadsaesuccenseees
T4y Cammophyllites.............cseccesccsvencsonns
TBs (CORLEW Se ocedcintcar docpensapsennonausonennooces
MGR SpilenopbiyWiina yn <ce.ascjncnss alco» sso seriecsis a>
item AOA ACMA Nels ceecisisssscecsjiesstosceessece ae see
Re Asher oply Mites svc. <caeeccces ess etereetaets c
GRO ALAMOS enectsaciasesejsscerccccceiiscenseseesecns
20. Artisia...... Ips yesncbcirodesbde anno can AmROSUIDoIEOS

bo

COP OR OR RP RHR OF OOTrHATONWD

is}

jt

OCONBDATRWNYE
SCNTONTAOHP HEH HE DWOWTWHNTIAND
it

bo

H

=i

PTPNODRrFOOCOOCOCOOrAAIHROKRTOO

SOCOCOCOCOCOCOFONNFOWROSO

FOrFCOOCOOCOCOOCAOCORRWORTDOSC
=

SON ONOCOKHOHP HEY EY HE EF rPaATDAOWWH Pp

* Since this examination was made (1860), the number of species of the Hlinois
fossil flora has been increased by the discovery of more than 30, mostly new species, —
to be published hereafter.

+ All the species of the genus Noeggerathia, as I have limited it, belong to the old
réd sandstone. There is no trace of it in the western coal basin. -

{ Our only species of American Dictyopteris is abundant in Pennsylvania, Ohio, Ken-
tucky, and even in Arkansas, and should have been found already in Illinois. Itis a
local species, always found in plenty, but in surfaces of small extent, and rather ap-
pearing in the low Coal Measures. '

464 PALEONTOLOGY OF ILLINOIS.

ojeq
s10u

peystiqnd you ‘sy

“ones

ey} Ur soloeds mony

*onZoy

-2]89 mM saloads

“2.

GENERA.

*SIOUTIT] UI $910

*sIOUT]]J Ul se10eds
jo dJequinu efor A,
-eds mou Jo 19quin sy
“HII U1 pungy se1oedg

*sIOMIT]] U1 punoy
jou pie ensopuzwo
Ur poqstiqnd saedg
jo saquinu ofoy Ay

- =| ~ — ———

MPa DOL AP INGUOS wae ccanenencaneencwarwcced seiner
DAL MLiy COPOUINGS recancccececsunaseeaieuntresesiisiacate
FEY SUV aIRAEW Ae sqogccaneogaoca con oa oaans0ecn90000
BA IP LAN ences cesiestncessuscelsenessecsinaccssued
ZOOS V WM COULMONOM eicacactsssvscasceeesicncsntence
26. Lepidodendron.....,......s.sesececcsenrereese 1
ie WAPPLOOPNLOVOS neossccesaneoasenivesasieveinestens
28. Diplothegium
29. Ulodendron......
30. Megaphytum.. 3008
SMC AM OPUCLIS meetensteccenscomianacsn cease emcee
32. Knorria..........

33. Lepidostrobus... pad nnadae coo.noa sap dd0 000
34, Lepidophyllum.... Ponceeatisn saeneserers ecmiece sions
35. Brachyphyllum..............0+00. pdo3agg85900
BOMOATATO Carp Onieerisescesenscaeseresroscneree sees
Bile RDA GOCALP OSpecescaasec-mccimene-eenees scree
SO. SUriSONOCANP UI peeks issceceerssehuecsesseeaeee
39 ACATPONEES veewwasiscsecsureisesecsseitases= arate
AQ NPINUUIALIA ss. cerssceuecesscssvssensoetaccenseiee

ist)

SOATWHOH URN OH DY HEY RYE ROO
i

SCR RNP OFRODHY NSF OCOCOCOFOMCSO

_
RPOTW OR TR WWRP NH DY OWATATOO

PRN OCOWNHENNOOFrPNH ODE W
SCWNSCCTCOFPNONNOOKRODROFHEH Dh
SCWNCSCONNONNCOFOAOCONH HH WH

e
i)
So

37 60 219 280 146

To this comparative table I will only add a few remarks.
The whole number of species hitherto known from all the coal
fields of the United States, is not much over four hundred.

Most of the species of our American coal plants have been .
collected in Pennsylvania, where the coal is extensively
worked, not only over the whole extent of the coal fields, but
in the different stages of the measures.

In Illinois, on the contrary, the coal is oiled at a few
places only, and most of the banks hitherto opened are roofed
either with limestone or with calcareous shales, having an
abundance of animal remains, but no plants.

In some parts of the Eastern coal fields, especially in Penn-
sylvania and Ohio, a number of Geologists and of amateurs
interested in the advancement of botanical palzeontology, have
for many years given their attention to the collection of fossil
plants, and have preserved the specimens, either in private
cabinets or public museums. In Illinois very few persons ap-

FOSSIL PLANTS. 465

pear to have collected fossil plants from scientific interest, and
it is evident from what I have seen myself in the coal mines
of Colchester and Duquoin, that the want of a more general
interest in the collection and study of the coal plants, is the
main reason of the apparent deficiency of species indicated by
the table.

From the collections made by Prof. A. H. Worthen, Mr.
Joseph Even and myself, there have been procured already
some data which are worth recording.

The number of new species, including those which, though
described from Europe, are new for America, is already propor-
tionally as great as in the enumeration of the coal plants of
Pennsylvania—fully 50 per cent. This is a new evidence of
the riches of the American coal flora. It proves, at the same
time, that we are acquainted only with a small number of spe-
cies of fossil plants, compared with what we may expect to find
hereafter.

The numerous and remarkable new species found within the
ironstone concretions of Grundy county seem to indicate that
the fossil plants preserved in the shales and sandstone of our
Coal Measures represent only a part, and perhaps a proportion-
ally small one, of the whole flora of the Carboniferous epoch.
The maceration has apparently entirely destroyed all the spe-,
cies whose tissue was not hard and woody. Some of these soft
remains have been left in broken pieces, as the nuclei of iron
concretions; but many, without doubt, will remain always
unknown to us. This conclusion is already indicated by the
great amount of fruits or nutlets which we find in various strata
of the Coal Measures, and which can not be referred to any
species known to us by their leaves or other organs.

In considering the fossil plants of Illinois according to their
_. stratigraphical and geographical distribution, we may still
remark :

Ist. That in Illinois we have, for the first time, the oppor-

tunity of studying the plants of Carboniferous strata lower than
—99 Oor. 9, 1866.

466 PALMONTOLOGY OF ILLINOIS.

the Millstone grit (from the Chester group of the Subcarbonif-
erous series). The plants collected in Randolph and Pope coun-
ties, though found in the Subcarboniferous measures, are mostly
species of Lepidodendron, Knorria and Stigmaria. All are of
the true Carboniferous type; some of them even, especially all
the Stigmaria, ascend high in the true Coal Measures above
the millstone grit, thus indicating for the low coal an identity
of formation by an identical vegetation.

2d. That the predominance of large vegetables of the
Lycopodiacezx, viz: The Lepidodendron is remarkable in these
Subcarboniferous strata of Illinois, and strengthen the conclu-
sion already takén from the examination of the Coal Measures
of other States: that the flora of the lower coal was essentially
composed of large species of Lepidodendron, and that these were
subsequently replaced by other species or genera. To confirm
this opinion we have only to compare the Subcarboniferous
fossil flora of Pope county with that of Colchester, Duquoin
and Mazon creek, three coals whose geological horizon is near
the base of the Mahoning sandstone. Here we have scarcely
any species of Lepidodendron, a few Sigillaria of the section of
the Leiodermaria, and of small size, and a proportionally very
large number of ferns. This peculiar distribution of fossil re-
mains of plants being, in Illinois, in perfect accordance with
what has been observed in the Coal Measures of other States,
evidently shows that the varieties of vegetation are not due to
peculiar and local influences, or to peculiar botanical zones, but
are truly in concordance with the different horizons of the Coal
Measures, and thus indicate successive or different formations.
, If, then, we were all to study and to know the plants which
have contributed to the formation of each bed of coal, the re-
mains of these plants, when found in the shales, would always
indicate a peculiar horizon.

3d. The examination of the coal flora of Illinois proves the
identity of vegetables in the whole American coal fields. The

FOSSIL PLANTS. 467

only fossil plant described from the Nova Scotia Coal Measures,
which had not yet been found in Pennsylvania and Ohio, viz:
Odontopteris subcuneata, has been found at Mazon creek. ‘The
plants of this last place are mostly identical with those of New-

port, Rhode Island. Those of coal No. 3, at Colchester and

Duquoin, are also mostly the same as ieee of the Haddoc coal
bank at Breathett, Kentucky, of South Salem vein of Potts-
ville, Pennsylvania, of Stark county coal in Ohio, etc. Thus,

I think, we can readily admit that the contemporancousness | _
of formation is recognizable over the whole extent of our coal |

fields, not only on a general point of view, but even considering | |
each separate bed of coal.

APPENDIX.

Stnce 1863, when my report was delivered, I have had

opportunity to examine a large number of specimens, found in _

the iron concretions of Mazon creek, near Morris, Grundy
county.* As the species of a certain locality, compared with
the number of specimens in which they are represented, give
us a pretty fair insight into the vegetation of the coal epoch,
at least for a peculiar horizon, it may be interesting to have
enumerated in a table‘all those which, to my knowledge, have
been found in that remarkable locality.

No. of spec. $ No. of spec,
1, Neuropteris hirsuta, Lsqx..............120| 9. Neuropteris Desorii, Lsqx........... otal
2 ue Clarksoni, Lsqx........... iH WO) uf fimbriata, Lsqx.@........ 1
3 ue flexuosa, Brgt.t........+ L} 11. ne Evenii, Lsqx........... esol 2
4, a plicata, Sternb............ 1} 12. ae pachyderma, Lsqx..:... 2
5. BY Loschii, Brgt...........+00 4| 13. oe inflata, Lsqx..........0.-
6 3 vermicularis, Lsqx...... 2] 14. RG verbenefolia, Lsqx.||... 4
7 a tenuifolia, Brgt.{......... 2) 15. Odontopteris Wortheni, Lsqx....... 3
8 a rarinervis, Bunb.......... 16] 16. Us subcuneata, Bunb.... 4

* Especially in the cabinet of Prof. J. D. Dana, of New Haven, of Schenectady Col-
lege, and of Mr. Even, at Morris; this last remarkable indeed for the number and
beauty of the specimens.

7 An obscure specimen only; it may be a large form of Neuropteris Loschit.

{ This species is abundant in the shales above and below the upper coal at Morris,
and also at Colchester.

§ A fine specimen of this species, with alternate leaves attached to the rachis. This
species, rare in Illinois, is common in the iron concretions between Athens and Mari-
etta, Ohio, at the same horizon. ;

|| From specimens in Mr. Even’s cabinet at Morris. The species appears bipinnately
divided; the alternate leaflets of the same form as the one described and figured in

i)

APPENDIX. 469
; No. of spec. No. of spec.
17. Odontopteris zequalis, Lsqx........... 2| 41. Pecopteris lepidorrhachis, Brongt.
18. Sphenopteris rigida, Brgt........ opood 2 (stems)........... Spoconmy 14
19, trifoliata, Bret......... 1] 42. &“ cyathea, Brgt..........00006 1
20. i latifolia, Brgt........ 1] 43, ot MeN AO. hose senna 65
21. a abbreviata, Lsqx...... 1] 44, &t Grandini, Brgt...... Becets 2
22, Hymenophyllites Clarkii, Lsqx...... 12] 45, plumosa, Brgt....ceere 6
23, a hirsutus, Lsqx... 1] 46. UG Murrayana, Bret......... . 4
24. Alethopteris Massillonis, Lsqx.*... 1) 47, GG Newberryi, Lsqx ......... 3
25. a Owenii, Lsqx.y........ . 1] 48. Cordaites borassifolia, Ung......... 1
26. ue Serlii, Brgt...........04 5| 49. Sphenophyllum Schlotheimii, Brgt 10
27. Gh Coxiana, Lsqx.......... 9] 50, ( emarginatum,Brgt 4
28. es crenulata, Brgt...... » 10/51. Annularia longifolia, Brgt..,........ 26
29. ue rugosa, Lsqx............ 1] 52. Wi sphenophylloides, Ung.. 12
30. iy Pluckneti, Brgt........ 3 | 53. Asterophyllites longifolius, Bret... 1
31. ui nervosa, Brgt.......... 1] 54, iG rigidus, Sternb..... 2
32 i pectinata, Lsqx.f...... 1} 55. & equisetiformis, Bgt 15
S33 Gh stellata, Lsqx......... 1] 56. CG foliosus, Lindl. and
34. Callipteris Sullivantii, Lsqx....... «. 10 Piuibivguesessecsesss 4
35. Pecopteris pteroides, Brgt............ 1] 57. (6 sublevis, Lsqx...... 4
36. 66 Cistii, Brgt........... acondD 1] 58. tc lanceolatus, Lsqx.
37. ce polymorpha, Bret......... 2 (Gites) /peecneccenee 2
38. ue villosa, Brgt...... ......00 185 | 59. Calamites nodosus, Brgt........ ....+. 4
39. ie oreopteredis, Bregt........ 3 | 60. OP approximatus, Bret...... 2
40. es arborescens, Brgt......... 3| 61. Selaginites cavifolius, Lsqx......... 2

the report, vary in size from one to three inches long.

To the genus Weuropteris should

be added some specimens of the formerly admitted genus Cyclopteris var. Cyclopteris

obliquua, Brgt., and Cyclopteris ingens, Lind\. and Hutt., both found at Morris.
is referable with doubt to Newropterus hirsuta, the second to Newropteris rarinervis.

The first
I

have seen six specimens of this last form, and ten of the first.

* An obscure specimen.

May represent a form of Alethopteris aquilina, Brgt.,

which is abundant in the shales of the coal at Morris, and of that of Neelysville and
Duquoin.

+ A poor specimen.

{ A new species, sent for determination, by Mr. Wilbur, of Chicago.

May be referable to Alethopteris Ooxiana, Lsqx.

It is a fruit-

ing frond, lanceolate, taper pointed in outline, bipinnately divided. The pinnz are
‘ linear, narrow, undulating, rather turned upwards from the middle, with a narrow
rachis; the pinnules are very narrow, short, linear, obtuse, deeply marked in the stone,
very numerous, perpendicular to the rachis, with a strong medial nerve, veinlets obso-

lete. In the upper part of the frond the pinne decreases in size and pass into simple
pinnules. On the same stone there are a few detached pinnules of Alethopteris Coxi-
ana. The new species might be its fruiting frond, though there is no likeness what-

ever in the leaflets.
@ Most abundant in stems and floating roots in the shales under the coal at Morris.

470 ened

No. of spec. No. of spec. ‘

62. Selaginites crassus, Lsqx.............. 1] 68. Lepidostrobus lanceolatus, Brgt... 1
63. Lycopodites asterophyllitfolius, 69. Carpolithes multistriatus, Sternb} 1

LSqXsseore ccsseccsscsseseeesssreseeseesere 1/70. Pinnularia capillacea, Lindl. and —
64. Stigmaria Evenii, Lsqx.*............. 2 ElWGtvecceWrecanevevensxes) ©
65. Lepidodendron simplex, Lsqx........ 1] 71. US fucoides, Lsqx............ 2
66. Lepidostrobus princeps, Lsqx...... 3] Seventy-one species, represented by 614
67. ce hastifolius, Lsqx..... 2] specimens. ;

* It is worth remarking that Stigmaria is generally absent in the shales and concre-
tions of coal No. 3. This may account for the absence of species of large Sigillaria. —
The deep part of the swamps appear to have been filled mostly with stems, floating
‘branches or roots, and leaves of Asterophyllites foliosus.

+ A remarkable specimen, sent also for determination by Mr. Wilbur. The end of
the fruit is truly flattened by a deep impression of a leaf of Callipteris Sullivantit,
proving that even the hardest veinlets have been softened to a mere paste by the pro-
cess of emerecausis, or slow combustion in water.

INDEX.

PAGE PAGE.
ACANTHOTELSONsssssessssseesses snes aaeerets 399 | ARCH AOCIDARIS......ssecceeeee seseccccseressns tO
Acanthotelson inzqualis..................-.403 | Archeocidaris mucronata........scesesceee 295
— Stimpsoni............-.....-401 | ARTICULATA «....000 seis cavatsnasceasieatessease 393°
ACTINOGRINUS ......0. egacedtee BeweetoeenlaigrZ (0.0) | ARIISLAUsst i) \usscccsuecveatachecssmsncensaceee4 0
Actinocrinus asteriscus.............. BepamneZON: It ASPIDODUB'4s-.ssceesecces eves, avcoteasanceesve -. 92
= CONCINDUS.......00+ steeeeeeaee 200 | Aspidodus ConvolutuS.........00+sses0ee0 «. 94
oe dodecadactylus........+.+4..205 — CLENUIAtUS ......s.ceeeseeeeseerer 9B
— pistilliformis .........0s...0151 | ASTEROIDEA ..scccceuceveceess epsonece obedecece 2277
— scitulus........ Sonenne cesonoon: 202 | ASTEROPHYLLITES ....... peogeeces Seeaceoncore 444
— SSMU re eestese sicietcsles cepdiceo 204 | ATHYRIS ......000. soonoadarcaenss n0080% wenseeeeee LD4
ALETHOPTERIS .....0csseceeee veeseees Steamsvsacls 438 | Athyris planosulcata......... pancbenodncea 254
Alethopteris crenulata........:...... coeeeee439 | AVICULOPECTEN. ...ccsseesesscease 231, 256, 326
— Massillonis........... pascseoon 438 | Aviculopecten amplUus............sseseesseee 257
—_— PECLINALS ........25-c000 enneee 469 — burlingtonensis ........... 231
—_ stellata........ CH G0 patennacc 440 _— CoxanuS........0000- roneeeeeo 2G)
Allorisma (sp. undt.)...... nodbeasaqaace +000 300 _ Interlineatus........04060.329
Amphibamus grandicepS........ssseesecane 135 a Koninckii............00000 328
AQMP ORACRINUStss0nct<cssescesneensveds cares 209 — OD1ONGUS ..........02200 +0000 258
Amphoracrinus subturbinatus............ 212 == occidentalis..............+. 331
PAINTS OB OD Mi eeretcntloaadccn<aisicse-dscicieesses +0399 — Oweni....... seeeeaeeneeneee e250
RGR TRITAN RUE cer Se cete enc baccecs sedi ica won4 44 == pellucidus....... sereeseeeee S27

JAN THRACERPIG! c..c0s(eccsccovcsstarcavscecoees 409
Anthracerpes typus........ ansconces pecker, 409 | BATOCRINUS....... Sevarsserncseen-o D0, LSI, 205
DACNIDIIRU PIA OM ONivescesete odcaccecteceeesidocece 406 | BELLINURUS.......,. Sec0ccad Baccoctce nncenenacos 3
Anthrapalemon gracilis....... Seater ee 40a bellinunus) Danes ccscccoscosncesseee eter ces 395
ANTLIODUS.....0..4 Siesescacuisseacortingecess 33, 38 | BanuzRopHon...... (Idocuddatodbaccoosbade 160, 385
AtnitlTO dus CHUCUILUS csctaceisscecssccseecccee 41 | Bellerophon crassus.........0..sssesccescnees 385
a TE PWTTNNS passe amesennoaee Voeseeen se 43 — cyrtolites ........... piecoronen LAH)
ans mucronatus........ Het Be ee 38 | BLASTOIDEA.........000+ adoabscocase baseanaabace 274
eee ATY AUS ess eses. ves. ccottecs 38 | BRACHIOPODA...... aera .153, 251, 280, 297

— FOUTS) noeeanégenecccceeeacooncace . 42
— MODUSHUSEs sccejacesesacascecenes ese 39 | CALAMITES ...cscceeee secceeee Baancododasoobccc ce Alea)
— similis......... aoe0bS sgnaascaanoc .. 4] | CALLIPTERIS ......0000.. eden 2Acosz0eRa Soontcotc 440
— SUMP XA ieeccscreeisarcesledesascese «. 44) Callipteris Sullivantii.............sssscecsse 440
— sulcatus...... dosssoasooos0ese coves 40) | CAMAROPHORTA.....cccccecsnacacasenscsestece 251
ARCH EOCIDARIDA .o.seceeescsees ooatsae ++eee-229 | Camarophoria subtrigona........ diseeneceee 20M

II

CARCHAROPSIS....... He SOoIIIIS SERS Sere . 69
Carcharopsis Wortheni.........rees 69

GARDIOPSIS teescens cccctencesaaticnnss perestas OO
Cardiopsis radiata...........+. Rect snsceereenetOl
CARPOLITHES......csseeeeeee Recaseseses Suceeeee -460
Carpolithes cistula......... AgReRoS sscnnanse tet!
_— FASCIULALUS c.vecce-ceseesvevesss FOL
— JACKSONENSIS ceseeeceeseeoreeee 461
—_ MUILtistTiatUS .....0..00eeee++ 460

CAULOPTERIS .....s.000 Dacelp satan? Ssonsee 905! 458
Caulopteris INSIQIS.....secererseee Sipdoson 459
Worthenii..........ccseeeeeeeneve409
CENTROORINUS......+ oagudasroodane s38o0 Snindaa0 172
CEPHALOPODA.........000008 161, 286, 304, 386
CHOMATODUS weeseerseoeee Measersenseaesenero, Ol

Chomatodus affinis...........ccsccssess sarees 54
55

_ ANGULALUS vreeeseeeveeeeresvere
— COSTATUS.....cccenecee SoonEcebon 85
— CUlLCLIMS, crecccns osx pesccrisacd 52
— elegans....... cwevasencencssous . 86
_— gracillimus.........0. ssaosncce Il
_ TOLITORMNTS se sssemeckssisesaer . 58
— TaN ANE| SoaneeMoooooocoossIonca Me
— MUltiplicatus ........ssr000. 57
— TOITENINS seo sroegnnanonssesconnas |)
CHONETES sescescecesvees So OToooECMnoangIS waDNKZA SH)
Chonetes planumbona,..........seeee Sts 253
CLADODUS...... practise Rdscinsnecoadcananrsssda%o 20
Cladodus angulatus .........s.seee sssesene 24
—_ (OEM EWI IS) --aanoddorononenonascas3c80 27
— ETO Rises eas seirecinccnesecenp eres ea er 26
— PTACIIS areas rpanens sronoaoston su Gio)
— QTANGIS venssecsenses= aneosenAdaccoae 8)
— TATAMOTGSS tee aace sieves eceneenseen tO
— MALNIACUS ....5.0000eee0r pacabasn, 2128
—_ WAU OW Saaccosthocoononcsaoac sacs, ZAll
— TeNONH Bb ET ees Heododacaeoco noc ocon . 22
— politus...... See nconadc Aaacannand ALL
— TODUStUS .....0066 Bas aenaanne aces 20
— SPINOSUS.....+00- teccecensroece sore 7474
—_ StENOPUS...0reee00e ssevees mseeensias 23
_ CUTIES ere ee ee ariaslsenss 28

LY FOPUS. weeeerere Senesver Apggasoes 25
Coal Measures, Invertebrate fossils of..319
Cochliodus? crassus....... nadocepacrccaonscn lL
Cochliodus nobilig..........sscccceeeeerevere 89
CGsTOCRINUBSesrssessacverstsrorcestere Gonecccnnn le

eS

PAGE,

Coelocrinus concayus......... Abcomacaronsos alle)
CorDAITHS...... Goosdess Selenoeabinaaeh tere nc anaeaseeee
GoOSciniUm ASteNTAiececesccecssesesasiecsssrseo lO
— CLEP ANN wescacsascecsoanpicnva staan lc
La escharensemesssseeerseeeres 416
— PLUMOSUM..........ceecerceeeee 414
—_ Michelinia.........6 seseseveee 414
— sagenella ........0.. Besosseoannac sles
— tuberculatum........... Sessosen LD
— WiOTtheniiccsccccsssssse ADO. 412

CRINOIDEA......147, 167, 234, 263, 288, 310
ORUSTACHA TS ..seccnssccesasenedassalssepeaesensOOe
OTENACANTHUS...... peUEdBnacsoticoaccaneacsarrnd ll
Ctenacanthus angulatus .....scsccrreererrl 18
2 COStAtUS)....-sccssnsenrenssLaO
gracillimus...... sascessecean AD
CTrENOPTYCHIUS...... Packeaiemet teeeseeanseOOnilin
Ctenoptychius semicircularis.:........++.
CYATHOORINUS ....cccseeessreeees 175, 234, 310

Cyathocrinus angulatus......s.e00 woe ae. 284
— Saffordii.cvessessses-eeeeeeae
—_ ? SANGAMONENSIS.......2++6. 310
— PBCULPLUIS verecnsueoasovesereseil OG

COXOTOBROR Avemseesicceueesenseaumeceiseep sesicueane ne aii

— POLYMOFPha........0seesecnere +421
CYRTOOMRAS ye..ssercosenass eeeeeaes ancien 220.388
Cyrtoceras (Aploceras) curtum...........388

— 7 dilatatum......csesccseecseeese G00

DAGIVUODUSa-s.cecaccrseccceccnesscadeasee aur o
Dactylodus inflexus ........ dodoassrioapcesoan 48
Moats sacnaemansedsseiaveeees Bocoe chit
PEINCEPSy.cereceneresienesicpinn

DRG ODA we ceewtuae sentacemsclaestenahastnunisestae sees
DHE TOD US sescnsconinsiecncasiseslonsiovsldonissaleseised
Deltodus angularis......... cosoress

—

— cingulatus........... Apeaconecucn, 2S)
— complanatus ............. nesersae OG
— = QTANGIS ......eeeee t necsescvosceres «101

THOMbOUM CUM yecccscesesserestersee LOO

— spatulatus......serecersscereerees LOO
— ptellalugi..<.cccacec cascsieretaneatees wou
—— UNM abWSiccccscesatieersssusereri= moe

Dentalium venustum ....... meee) 1284
DICHOCRINUS sss +cevceessrccvees svecercves LON, 20d

PAGE.

Dichocrinus CONUS ...sccsscveescseeeseeeeeees 169
UPAAOMITSM eee s savas sae vadataernstweavcckses 59
Diplodus COMpressus.....sssesseccsseeseeeee 60
—_ duplicatus....... Reiniiedbavslcsiae a (OL
— AIGUMVALS fereekcescisaatewssiec>orcscs O
Ei AMIE HUB Won etisnhneeseee Diecswcdssiesess, BO
DREPANACANTHUS. swsssccecsecsseeeseeee -120
Drepanacanthus anceps.......0...0- Chicietran'= 122
—_ SEMMALUS......eeereneeeee 123

— ? stellatus......s0sc beet 45)
EXCHINOIDEA..eeeseeecesseseeeseeees 220, 247, 294
HECHINODERMATA.....147, 167, 234, 263, 288
EDESTUS ...... nnoceon: Raesieshhestiatnainannieexeire 84
HIG OStUS HOMO se skvechsbnetatessiskesessensetsas G4:
EDM ONDIVAG acoveeals(coseeclertessessicnesseentieacwerO 40

HEdmondia unioniformis?.............00066.346
HIN DOL OB US acess besbassaujlaceswseesovacaes erat Ong
ENTOMOSTRACA seseecece ceeesees Races somes 393
ERISOCRINUS......005 aasenvatininswsite paumeese hele 315
HLisSOCrinus CONOIGEUS........eceeveeeees oon tg)
— tuberculatus......... siaeieseaeate 319
— (OW Sheermonteecees Godan cmansOsaee 317
IDIMTGRODIS:..5.s0csrsencaceisnvaes Sec Ores 1050336
Humicrotis Hawni var. sinuata.......... .338
EXUPACHYORINUS ceeseceeneescrces shecdan ReewtollTt
FORBESIOCRINUS ....... Srasestiduusswerissice 270.
INOSSUIMMCLNIG... .ccccncsccesccessnsuseses Gaceavess 427
Fossil Fishes in Illinois strata, occur-
ROMCELOL sc csseecssacees Ssepiotesaie Wamaahtaseeeec Lalas
Fossil Plants, report OM.........sseseeserees 425
GASTEROPODA...... 158, 260, 284, 302, 351
GONIASTEROIDOCRINUS .....0ceseeeee ~- 219, 222
GONTATITHS. ....0.08c00000 Gnedasoooednaaco Gly eX
Goniatites globulosus ............. BACKER 390
— LOWEDSIS ..cccsceeveceeces a BH
— ILD YONA, aceboantooenenoeausooouanep Ges 165
GRANATOCRINUS ....cccececesceees Pieaestonatciacs 274
Granatocrinus cornutus...... RivcciNicletuinerse 276
GILBERTSOCRINUS.......... conan 217, 219, 222
Gilbertsocrinus fiscellus............00.0006-222
Gyromices ammonis........... Aoccesobeseebes 462
ERR OD UG Wisc ante iowwcvosncite eekeats Rector cone ties
Helodus angulatus..........0.s0c00 nobpodaos 83
— biformis ..... asetontceeescececcasecs TT

Oct. 10, 1866.

PAGE

Helodus carbomarius.......scccves Seana 75
==); +2 \COMPLESSUSs..sacecensavcetereeveve en (8
— CONMCMIMS) Coes cscavcen tees wisiaehtseesia 75
— Comsolicdatiisiesdesesasccenstecean tell
— crenulatus .......s000. apecesas Riker 82
— denishinmianieisechjsscessivecierteeaesia iG
—_ Gemnbiclaitistssersssaccsneseeeecser 81
Eom! ea CLYjUDHi variance telseamtiepneesnishon eaten tetes 78
See UD DIOSUSieereeetseeieceie peniroseaste ge 79
— Timex inpeckvscmceaeemeessepeeerseenieee 80
— (Cochliodus) nobilis....... Ponca, ats)
— Dlalcenitian sonscesescureiewceeresc eet 80
— POLUHWSceNs sieved eel wore 79
— SIDUICEN AT hieeannaconctiigce cescs .. 83
— UNGAULACUS. osedvttneeecdveceeaeeeen Oe
HOMACANTHUS ..2s:cecevescvacda vec pleats}
Homacanthus gibbosus..........0.s0000e0e113
— 2? rectus...... ghoenoosoonoconcs 115

TAY MENOP HV LITES | 0.0. ccesceanesse onsets reves 436
Hymenophyllites alatus ......... ep anoeedgd 437
— Clair Kisiietecekeaeee 438

— hirsutus............ 10000437

— pinnatifidus ............436

— SPINOSUS ......0.-eeeceoee 436

ADIN ISIE OTA Es Sas cise lesloisslomeisiearesielonsievcisawseomienaines ALO
Invertebrate Fossils of Coal Measures..310
Invertebrates, supplement to...........+4 412
ISOPODA......0000- .399
LAMELLIBRANCHIATA..156, 231, 256, 281, 300
LEPIDODENDRON .......-ee0e0s «451
Lepidodendron clypeatum ...............+ 455
— COSTATUM, ...... 00000000000 403

— diplotegioides............452

— ODOVAtUM... 0.0... 00.0000 455

— ODSCULUM...... 2.0 see eee ee 453 |

— TACICADS ...... 000 cece vere 44

— SIMPlEX ......... see eee eee D4

— turbinatum .......6.s...+ 453

— Velthemianum........... 455

— WiOrthenil \ccecscrccccsens 452
LEPIDOPHYLLUM.. ..-0-seeeccccsssccecsvescceses 456
Lepidophyllum auriculatum............... 457
— lanceolatum ......... Geo anc 556

—_ ERGY|TIS) sanindcrososriagD AaCOOoOE 456
LEPIDOPHLOYOS. «seccscescscsenceeceerecceeseoes 457
Lepidophloyos obcordatum................ 457

IV

———————__—————————

PAGE
LEPIDOPTERA wcccccsessenves Oeecuenee ieee seas 410
LEPIDOSTROBUS.. KA aOaeee ere uetcnchincen EDO
Lepidostrobus hastifolius Ra ghascestifaccsty -456
_ PLINCEPS.....see. seceseeneae4 DD

TMP MAGANWDUSsvucievietccnvemowsbasiseieed se wore LLG
Leptacanthus? occidentalis...............116
THORONRMNA occ cocsclvsencoosbindchetivabeentibaas acs 317
Loxonema cerithiformis ........ Sbeee asses 379
— multicostata........- ecuseawenes 378

— TUPOSEH..0.s.cccccenscenveronecesess 378

_— SCUMULA en eweaee clases stetaccnass ek 377

TN COPODITED ces'tanscuncnacisaceebisbassawalsasec ae 447
Lycopodites asterophyllitefolius......... 447
MACROCHEILUS ......-.secceseee Sahencsosadb0de. 367
Macrocheilus intercalaris...... Secalsies salves 371
— MEIALIS...cccercecee .370

= (dt) P Rabe ec sserewen 8 12
(MWAVG TR Ung seen enimiensantameorieiias acetates siemeests 406
MARSUPIOCRINITES......0.. Sabine nee see Ratsed 172
MARTINIA ..1ccvsnsscennaciensssrecsesrenselOO, 208
MBGAPHYTUM ....-cncccsessccoreseccsrcceveseres 457
Megaphytum McLayi............ BOONE 005% 458

protuberans ........0++6 458
Melonites multipora..........s00e000.227, 228

neeaee

DM ONO P/SIS leteieiom\ajainerailola\aranisatle)s] oleae sisted nace 249
MouuuscCa........- 153, 231, 251, 280, 297, 320
MONOPTERIA ....... GaSe oSnaNeeBaeceHcoe bucbodlans 339
MYALINA......0sscecsa0e dosboseacos 281, 300, 341
Myalina angulata.........cceceoesesesereeseee 300

==) (CONCCIPTICA ecssqnesi-cwsiiinehingasls 281

——"* MEliMIFOUMLS sins sesnmisioaseceearipnn 343

TECULVILOSETIS. 00.24.00 cee eee

Se | HOW AO Milestens pakineslehe nesles durinas «as OA
MYRIAP ODA... 0s. ccecveass ane cane 409
NaAricopsis . Sere 363
Naticopsis nana, ho 365

— npdeuare var. Holliday... . 367
— (Trachydomia) todean. nando 366
NFAT OMG So eeleceisceaeiamanseiels spears 161, 305, 386
Nautilus chesterensis.......... Saeanieia pase 306

— = GIZONUS......secscaneeee RaCa NBO SUC 163

— globatus!......... Scepercananistsesa 305

— planorbiformis ..........sss000 386

— .SANZAMONENSIS ........+00, PCL 4°49)

(Endolobus) spectabilis........308

PAGE.
Nautilus ES) trisulcatus...162

NBEUROPTERIS ...scsecsccecerees Riis wie ONT
Neuropteris Evenii..... eR
— ANH EIAs aeisaisieehomalelsws sstbielams s'eoeeoL
— Mb ESAPUIEY Anceern negconsssomeedee al
— pachyderma..........+0+ +0430
—_— verbenefolia... so... ceeece ee 431
INTC ULAIN Asses cciacalecawentash tsb hieneldnelopniensien ieaeccrs
NiiGuilainia:?, CUT tal janis sbrensisien salons ane sesieveeecoo:
ODONTOPTHRIS)=s2.-necskceesseuriars toeieeseeniere oe

Odontopteris z2qualis.........ss00e.

— Worthenii......... ccc cee eee 0482

— SUDCUNEATA 00... c0e cee eee eee 433

— heterophylla .........40. 06.0433
OLIGOPORUSG v.csvesrsctontereratowssterscnceneon ll,
Oligoporus Dane .......... 000 ceceeeee eve vee ene 249
Onychocrinus MONTOENSIS. ......000+.0 e001 244
— INOW OO diascascsrssctcosteescecsm 245
OBA CAN THUS ccviscxscesecaspouscenvsssovesveteincersenrente 117
Oracanthus pnigeus 11
OrRoDUs ... ceaeniedceedstthceeconsdemi On
Orodus elaserinee Scored 5ioq exanconogwors (BE
— mammillaris................ Snmcpopdd (hs
— = MINUSCUIUS .........ececececsesereees OF
— minutus...... Sele snes saint eadeaarereedy 68
— 7? multicarinatus.............. veveve (OM
— ornatus.......... Snengon6ds damcbasoaso hel)
Ea PU CAMS eananceescsceneseasacinaseande Oo!
—= T 4UDEreUlatus'......csscnccccerewavess 66
ORTHOOERAS...cccnssceceemecerencscsteces 286, 304
Orthoceras annulato-costatum............ 304
— EXPAN SWea sess eseeeplmeanaane +. 286
ORTHONEMA......... Silene Botianeasers ainceacnas -380
PUAN 20 CHUN DD tes sesnecisisinne sisinaivn dele ee aAsonas 229
PALAMOHINUS....+-scesvers MisiRee nen ae analensene 229
Palzchinus burlingtonensis...... Soossecnc 230
PALBOCAMPA.......e000. poconodaabaenc Rokercane 410
Paleocampa anthrax............. Seiten 410
PAT; 200 CURIS ease scmceiseeceess danancsee cideeaateas 403
PaleOcaris tH PWS. msec sacaaencasetinacssenaney 405
FYATZOONUS OUR) <sa0caeisemecaicanaisiiaapescnieteene 17
Palzoniscus peltigerus ...... Hpoonscericsente “Li
PHCOPTERIS.....ccseeeeeseees Ara oeeercp rer yiiceil
Pecopteris callosa........ Giaaeippeeisemeeetaee 442

PERISCHOECHINIDE ..eeesereereee220, 247, 294

a

INDEX. V
PAGE PAGE
PETALODONTIDA vevessececcncccevessscecve -... 31} Polyrhizodus porosus ....... olaeintetteenar ae 49
Petalodont genera, Synopsis of........... 31} Polyzoa, descriptions of.........+. arenes 412
PHDATODUSicnnasens ensnn=-0 npodsabpcdasuhee Sips 5) PRO TERIO CRIN US venssaesschasesseediecress 179, 237
Petalodus destructor.......ccsceseceee sO3C00 35 | Poteriocrinus Swallovi ............ssecaseee 183
—_ Tin QyafOP -s,sewacher<<<lacsemeloee Reif) (eR OD OMS sosnsscvcenesesrereneres 280, 297, 320
PHTALORHYNCHUSs.seceseeee cca es a 32, 40} Productus nanus.......... siete a erent 320
Petalorhynchus striatus .......s000secereeee 40 = IOEHINAEIS Stamascacioerenias ante Horace: 297
PEPRODUS .....00cceeeeee. Sefatia vais aaa geats Renee 70 _ scitulus...... mis at uisleamtailetetesemane 280
Petrodus acutus ......... Ceternnroctcn angie 1(2)) LP TOMNOVAQIN poonpacenerceassaancecccos 145, 262, 233
as Maciclentailisesc-te eee acne an Ol SAM MODUS... cceccecscoceveccuucheescneececacess 107
PETROSPONGIAssssereeeceeseoeese L450, 233, 262] Psammodus angularis .......sceseeeee sence 107
PINNULARIA.....+005 siainaans sige iee saabucceheab bee 461 —_ PONOSUSH) cancccmiteseneenaanceey 107
PLATYORINUS......-. Rocreocerisn BngAaooeEn 170, 264 _ TELCO EM ADIE| SaonaeAgenoncncron cr 109
Platycrinus penicillus.........csecsceseneees 266 = ? rhomboideus .........4. seal LO)
— plenus...... SocecenciQonSnso9 200 267 = TO SUS) oc save lect sereeaeaeeete 108
— Prattemanus.....cccccceseceee 264 _— ? semicylindricus........ +109
wae subspinosus........ ee sets 5. sake ABs MELDERIUN DIAL -osaicinajomep asain ceericeaseipie Samaras 339
PLEUROCRINUS..sseceeeeeereeseeeeeeeess.L 72, 173 | Pterinea (Monopteria) gibbosa........ +340
PLEUROPHORUS....0eeeceeeeee PERC AEEaseO ie 347 | PTEROTOCRINUS..........00ee0s apPoneocanacren 288
Pleurophorus subcostatus.................347 | Pterotocrinus chesterensis........ssscsse- 292
PLEURTOMARIA ....000. tas vaneaceas 260, 303, 351 = GUPISISNEIEL aosragcnannnonncoosgncs 290
Pleurotomaria brazoensis......... noodteced 354

5 RADIATA... ....0- 147, 167, 234, 263, 288, 310

—_— chesterensis .........066 .. 303 u d : z J
FRURENTOIIS sin cscess sisenencadccacissecsccvcen cans se 106
—_ granato-costata ..........356 ERS eo sleColtts Ave

—_— PLAGienlseiscsesascesesaccs 357 SREP Dh PARE eae eT
ae ROU een nee nao 353 UYINOHON BELA \isssssciscesacnesnscvecuasnciress 153
ia Sipterced ee ok aa Rhynchonella missouriensis..........0.0:. 153
ae APOCHOSE cane cde sence 352 EUETAZ/ ODIO Sitsla eewsceictaineleiariee ssoaeeeeisjaceecemaces 3) IL}
es SRC OTIC RICt al eee 351 | Rhizodus occidentalis..... Boapdonods eceen eee 19
yp SuBecateris ssepanereancnr ODO St. Louis Group, Invert. Fossils of.......262

-- subsinuata ...... maeiesteeee 358

aus Beard ap) vy, oad 355 VANDA ODU Sis. ssssissanceascstecsacsescaceaveeees 102
iba’ peter AE ADDR Gaal ts CHETAN Sandalodus Bar nek ennoOr pongacouacnnedcs 103
tae FS Magan ae eee 359 —_ earbonarius...... peconenac donc 104
Poecilodus Ornatus..........ccceeeesecreesees 95 iat Stands’. -2-.2sc..: an Sige See OS
Sao TIO SUS R este ane cmeoees ersten tak 94 = LeeViSSIMUS «-..-2++eeeeeeeerens 104
PROMCMONAY Meutchinre te eel tinesacaser sce ase, vonseA4al ca PATVULUS..sceeeesereeeeescee eee 102
Bolyporai/praeilisies seccsaesestienssseccesen0 422 <= spatulatus....... seneeevereenens 1038
Me Hallianan ce nee. eek 421 | Section I. Vertebrates...........00. Seoases 9
— ThamiltOnensis.......0.ccesecceeece 423] Section Il. Invertebrates...........sse0+0+ 143
POLYPHEMOPSIS ........-0eesesereceeseeereeeed72 | Section III. Plants........ GaaconsnoDaGOc Os 425
Polyphemopsis inornata.......... Bieeiesone STAs | PS WIWAG TNT HG: a cnclssisiclentecisis or eeslecsesiieeaaceaa 446
— nitidula...... cadeboeponaores 3174 | Selaginites CraSSUS......ssscseseseseveensees -446
— DERACWUA) weccsesciesseser es 375 — UNCINNAtUS......... anoosuonaccas 446
POLYRHIZODUS......00c000 vee paacoapaodencec 34, 49 | SCAPHIOCRINUS ........eseeceees sete noeosocs 237
Polyrhizodus dentatus.....cccscsescssscesees 50 | Scaphiocrinus decadactylus.......... 000 238

_ POMFICUIUS.........00cc0s0000. DL

SCHIZODUS ...ccserrereeeseeseerevcesoesee-S0l, 345

VI INDEX.
nnn ee Inn D nnn nen
PAGE PAGE.
Schizodus chesterensis ....cevseeseeeeeseers 301 | Straparollus similis ........ modtecacon jer +285
SOHCENASTER ..cccescesenccececcneeeeenane cents 207 —_ similis va7. plenus.......000+ 286
Scheenaster fimbriatus......+.e0+ ereeeetesn 278 _ UMbILICAtUS. ......seeveereneee 362
SUGILDARTA.cccesreseviececsenenecssennsnss 447, 448 STREBLOPTURIA .eseeeseeeeees sicllisulds cathaconeane 332
Sigillaria Brardii ......cscccseesereseree cere 45] | Streblopteria? tenuilineata,........2000+ 334
ae Gnbermedlalvsssiheccomeeeenestons 451 | SLROTOORINUS «seeseseeseeee ieseneee Aectrescd .188
ead Menards ccuieccesstosonsece 400 Strotocrinus regalis..... SuoBdee tutte aces 192
— MONOSTIGMA.......cseeeemrereeere 449 | Supplement to descriptions of Verte-
— TEMUMONMAIS seecee ec euceislcieneiicenslne 451 TDIEDLC Secmenstereitalcemrenteldenieeietals BARRAGE CALE rer oli 3)
= Cul piiaeessoricassceceeirncsteaermce 450 | SYNTRIBLASMA 2.0000. cesccewee veoveescscesene Sol
=e HORGOL Tatas seea oan ee eee 451 | Syntrielasma hemiplicata.......sceseced23
oe Vrarrdllevalesraneer sere eeeeee ssernee 45] | SYRIGODENDRON ...ecceseeee - eeceees Apcoscoshil
SOLMNUSCUStsce ce nec aceseeoeczee tec onenans sane 383 | Syrigodendron pachyderma.............+. 451
Soleniscus tyPicus ....cesesceceeceeesreeseees 384
SG OMMNOMW Ass icdswedccclesosehieaee cei poretoreeiact 349 | TAXOCRINUS..+00+0ressees soeeescecceceens 268, 210
Solenomya radiata.........0see seesees sia 34g | Taxocrinus semiovatus ..........++es0- 1 272
Sp HUNOPHYLLUM oes beleeeeleeeoesekenueeone 444 | TETRADECAPODA......++.. doogronqeeoaondaasocs 399
SPpHENOPOTHRIUM fcscccotceetesee 145, 233, 262 T RACH YDOMIA ves ccceenecuseeceeesannvesen 364, 266
Sphenopoterium compressum......-s.++- 934 | PREMATODISCUS ...... saanonaincoeaseaseesenens 161
es GiNROA TAY Jes 262 TRIGONOCARPUM...ssseeeseseeeeees Apsnosctornos 460
es SOTO ao ee eae 146 Trigonocarpum rostellum..........s.s.-.++ 460
es enorme var. depressum.146 — juglans........ anonaspacreca 460
woe UCR GIG ess ee 233 TRIGONODUS ....sescsreccesesscenees ssogec se5sco 111
SPHENOPTERIS......-2seeeeee edocs soe canewereee 435 | Prigomodus MajOr....ssseeeeeeerereeerrees 112
Sphenopteris paupercula.........++ere010435 a ZCI SNe PS peaconcice re Ag Ce209 Teenaeeleee 112
fei Tigida sss Neeit ASS Vopeannais soopnocenes papedenosoenatecaadons 382
SuVmINMR scam eeetonts sere STS SO pe IES SPEDE ES TIEE ats satoso3 soos 382
Spirifer COOperensis.......sseeee: seveereeeeLO5 | UPBROCRINUS cccececesaesceccescceceseatcneecess 151
— glaber var. contractus .......... 298
Spirorbis carbonarivs.......ccsecceereqeraee-462 MIP HOS URAC Sei ctwececseencsseveessisetewemers cers 393
SHON GEA Rerexieedagaee sestasea ORES Sr LO Veo rim een comer ce te ee eee Heaaiescee Oe
ISTHE AN OCHINUA pa schetereren Renemnenenmscrr |) aWoldaa/? Neyiieria tae see |e eee ee
Steganocrinus aTaneolus.........cessseeeeee 198
STIGMARIA .....00eeeeeee Faa3 Aqvansanaagoan sag ser 4A | ZEACRINUS...0.csssaeeeeee cosnoncon -185, 240, 312
Stigmaria Evenil............- Speanocoasrocaas 448 | Zeacrinus? crassus........- Sanco niconcca nono sHl st
STRAPAROLLUS.ecscceeveseee 158, 285, 302, 362 — CMS GUS eieekeenisnetheeeesisi cereeneend 12
— len Spwaame-reeseieee asoso0ec) argagd 159 — planobrachiatus......ssses0: 240
— planidorsatus........sssseeee 302 — Troostanus...... neonnceag Beso 186

secibieurine ath oie

7 ull

¥ a 7 ie a
7 . hoe 7 a -
~~ : Vo! ff Na
on el
- ie
¥ , ~~.
ERRATA.
oye,
Page 61, 15th line from bottom, for “D. gracillis” read “D. gracilis.” ha
Page 71, 9th line from bottom, for “exuvee”’ read “exuvix.”” 8 F
Page 81, 10th line from top, for “Strophodus tanuis” read “‘Strophodus tenuis.” Eo ;
Page 114, 4th line from bottom, for “spacies” read “species.” ce
Page 124, 17th line trom bottom, for “stringent” read “‘strongest.”” A

Page 126, 10th line from bottom, for “Ctenocanthus” read “Ctenacanthus.”

Page 131, 6th line from top, for ‘Ch. loriformus’’ read ‘‘Ch. loriformis.”’

Page 135, 3d line from bottom of note, for ‘above the middle” read ‘‘near base of Coal Measures.’””

Page 137, 1ith and 14th lines from top, for ‘‘Opisthoczlian” read ‘“‘Opisthoceelian.”

Page 138, 2d line from top, for *Borborocstes” read “Borborocetes.””

Page 146, 12th line from bottom, for “Gonialite” read “‘Goniatite.”

Page 150, 1st line at bottom, for “species” read ‘‘specimens ;”’ also, 18th line from. bottom, as well as 5th line
from top, of p. 165, for “palceontologists” read ‘‘palzeontologists.”’

Page 152, 3d line from bottom, for “graulose” read.“‘granulose ;’’ and 12th line from top, for ‘hexigonal” read
“hexagonal.”

Page 153, 15th line from bottom, for ‘*Rynchonella” read “Rhynchonella.”

Page 160, 6th line from top, for “1810” read ‘1808 ;” and 7th line,.for “II, p.174,’’ read “I, p.50.””

Page 167, 4th line from top, for ‘‘Miller” read “‘Munster.”

Page 191, 5th line from top, strike out “the” after ‘‘Batocrinus ;”’ and 14th line from bottom, for “Prelim” read
“Berlin.”

Page 202, 8th line from bottom, for “‘abconical” read “obconical.”

Page 218, 9th line from: top, for “‘supraradials 3.or 4x10” read ‘‘supraradials 2x10 ;’” and 2d line from below,
for “over the interradial and anal spaces’ read “over the axillary spaces.”

Page 240, ist line at top, insert ‘is’ before “like Scaphiocrinus simplex ;”’ 2d line, insert ‘‘but” before “differs.”

Page 263, insert ‘“‘Dichocrinus constrictus, M. and W..,’’ between the 9th and 10th lines from top.

Page 272, 9th line from. bottom, strike out the ‘?”’ after “Body.”

Page 280, 13th line from top, for “1814” read ‘1812 ;”’ and 14th line, for “tab. 68’ read “I,.p. 53.””

Page 299, 4th line from top, for ‘Dorsal valve” read ‘“Ventral valve.”

Page 364, 8th line from top, for ‘‘shell smoother” read ‘shell smooth.”

Page 396, 11th line from top, for “‘sim- eyes’”’ read ‘‘simple eyes.’”

Page 415, 18th and 15th lines from top, for “Saganella” read “‘Sagenella.’”

Explanations of Pl. X, 4th line from top, for “angustas”’ read “‘angustus.”’

,
N. B.—A few errors and omissions in the references in the text, to particular figures.on some of the plates,
are corrected by the explanations of the plates.

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2 a.
2b.

CLADODUS ROBUSTUS.
Base in outline from above.

CLADODUS MICROPUS.

Side view.

Base from above.

CLADODUS SPINOSUS.
Base from beneath.

CLADODUS STENOPUS.
Base from above.

CLADODUS MORTIFER.
CLADODUS MAGNIFIcUS? Anterior face...........s..000006.24 Ht i
Base from above.

CLADODUS ANGULATUS.

Anterior face.

Base from below.

CLADODUS ZYGOPUS.
Base, under side.
A larger specimen.

CLADODUS FEROX. Anterior face......
Base from beneath.

CLADODUS POLITUS.

CLADODUS cosTATUS. Anterior face......... cut: Nathanien tent C hasl :
Base, under side.

CLADODUS TURRITUS.

CLADODUS GRANDIS.
Base of a small specimen.

- CLADODUS LAMNOIDES.

Side view.

CLADODUS GRACILIS.

Anterior face....

PLATE I.

PAGH

Anterior face.......seseseeceseeeeees 20

Anterior face....

Anterior face.......... Fasclgndedeaeee

Anterior face.......

Anterior face............. suagelenenee

Posterior face......

Anterior face..

Anterior face....

Anterior face.......5 sscees

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PAGE
Fig. 1, la PETALODUS DESTRUCTOR cc... scss:nnedusnrcne’ east eieeananere
2, 2a. Anterior and posterior crown faces of another specimen:
2b. Root, posterior surface. y
2c. Profile section.
3. Small low tooth.

rs

Fig. 4. PETALODUS LINGULEBR. das nnope diveses es naeaa ee Lune

Natural size.
4a. Vertical view. :

4b, Profile section.
5, 5a. Posterior and anterior views of worn specimen.
5

ee

5b, 5c. Profile sections of two teeth.
Fig. 6, 6a, 6b. ANTLIODUS MUCRONATUS....0cccccsssessesssessevssseseesDQ Ot Qe
Posterior and anterior views and section.
Fig. 7, 7a, 7b. ANTLIOD US: PAB V UWS canescens sols on septa eem nl: Ape e ees
Posterior and anterior views and section. r ;
Fig. 8, 8a, 8b. PETALODUS (Petalorhynchus) STRIATUS....... Savery a wal
Posterior and anterior views and section.
Fig. 9, 9a. ANTLIODUS ROBUSHUSyrene lente sis see eee ee Autti
Posterior and anterior faces. Ng
9b, 9c. Side view and section. : : ;
Fig. 10, 10a. ANTLIODUS SIMILIS......-.+. se tivsacondesinenwnp sone nces4 inn
a |

Anterior face and section. a

tae, Es

ale PL. 11.

CARBONIFER OUS>

Dr J.S Newberry, del A.H Worthen, divext. Western Engraving

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PLATE III.

PAGE

ANTLIoDUS cUCULLUS. Posterior face..... aravaurnetnns sicher 41
Anterior face.
Section.

ANTLIODUS PoLITUS. Posterior face.............ccecseee 49
Section.

ANTLIODUS MINUTUS. Posterior face, natural size....... .. 48
Same enlarged. 4
Section enlarged.

ANTLIODUS SIMPLEX. Anterior face..................00- 44
Section. 2

ANTLIODUS SULOATUS. Pesterior View....... re ee . 45
Section. j

Dacrytopus prinorps. Anterior face.................. . 45
Posterior face.
Section.

_ Daocrytopts topatus. Posterior face................... 47 >

Section.

DaoryLopus infLexus. Posterjor face............... Ais GALS
Section.

PoLyRHIzODUS PoROSUS. Posterior face.................- 49
Section.

PoLYRHIZODUS DENTATUS. Posterior view.............-.- 50
Section. ;

PolLyrgizopus PontiouLus. Anterior face............... 51
Section,

CHOMATODUS GRAOILLIMUS. Posterior face............... 52
Section.

CHOMATODUS CULTELLUS. Anterior fate................. nD,
Section.

CHoMATODUs PusiLLUS. Anterior face................. ae SOB.
Crown from above.
Section.

CHOMATODUS AFFINIS. Posterior face...............-++-> 54
Section.

CHOMATODUS ANGULATUS. Posterior face ..............- . 55
Section.

CHOMATODUS MOLARIS. Anterior face..... EEN as ras oe 56
Section.

CHOMATODUS MULTIPLICATUS. Posterior face............. 57
Anterior face.
Section.

CHOMATODUS LORIFORMIS. Posterior face.......... ne Lone, 58

Section.

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CHOLOCUONG SWNT We Were iS

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PLATE PV:
PAGE
Hig. dholasle. , sDievopUsiAnus ie psec -leiieerrreteratieitele shes ates he detanets oye ete 59 .
Fig. 2. DIPLODUS COMPRESSUS .........2+-0000 scaertor hetero te de bids O08 s
Fig. 3. DivLopUs DUPLIOATUS......-----2-0-eeeee shite Heseeee aes Reon 2 ,
3 a. Opposite side of same tooth magnified.
Fig. 4. DirpLopus incuryus. Posterior aspect, enlarged.............. 62 4.
4a. Side view in outline.
: ’
Fig. 5. Orovts pLicatus. Side view........ eel ateke fedora eve ete ete thet tote 63 db nwa deo é
Fig. 6, 60. ORODUS ELEGANTULUS. Top and side view....... OC Reig 3 . 64 Buadkoneybs Se :
| pk Lone
Fig. 7, 7. Oropts orNaAtus. Upper surface large and small tooth enlarged. 65 Kuk! we
8, 8a. Side and top views of smaller specimen, natural size. ¢ a
s+ wo ue
Fig. 9, 90. Oops TUBERCULATUS. Side and crown surfaces exlarged...... 66 Buotargles By
Fig. 10, 10¢. ORODUS MAMMILLARIS. ‘op and side views, natural side.......66 Katha, F a Le
Fig. 11. Oxopus minusoutus. A series of four teeth, magniffed once... .67 Rieti, . =
Fig. 12. Oropts minutus. A series of four teeth, enlarged once ....... Cog
Fig. 13. OrRopUS MULTIOARINATUS. Upper surface, natural size......... 62 Kivid extent g rf
3a. Side view of same fragment. ee
Sub~tede
Fig. 14, 14a. Caronaropsis WortsENI. Posterior face and profile, nat. size.694 Wulentte -
Fig. 15, 15a, 15), Pzrropus ocorenTauis. Top and side views, two specimens..70 Cov, Yrrex 7
Fig. 16, 16a. PETRODUS OCCIDENTALIS. Var?
Fig. 17. Prreopus Aourus: | Enlarged. oc: os. veceh oe ee ee 72 Cook
Fig. 18, 187, 18). CrenoprycHits SEMICIRCULARIS. Front, top and side views....:72 %*
Fig. 19. 194. HELopwus conicuLus. Posterior and side views..............- To x eee Boel
Fig. 20, 20¢. HELODUS CARBONARIUS. Posterior face and profile section..... 75 Cok enews
k
Fig. 21, 210,214. Hztopus pensaumanr. ‘Top and side yiews and profile..... .. 76 Rar Xs
Fig. 22. HEtopvs Birormis. A series of three teeth.............. alate tater
22a. A detached tooth.
c St i ‘ . Ca / bd 2 y
Fig. 23. HeEtLopvs ELyTRA. A series of three teeth..:............. ee 8 (rived ee
Fig. 24. Epestvs minor. Side view of tooth, fragment of jaw attached. .84 Cas. Yragu

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Fig. 1.

Fig. 2.

Fig. 3, 3a.
Fig. 4,44,
Fig. 5,54, 54,
Fig. 6, 6, 6,
Fig. 7, 74.
Fig. 8, 84, 85.

Fig. 9, 94, 9,
10 to 15a.

Fig. 16, 164.
Fig. 17, 17 4.

Fig. 18,187, 18", CooMaropvus ELEGANS. Side and top views, and profile section 86

Pie a os,

HeLopus compressus. Dnlarged to two diameters............ 78 Pramolorry bam
Hetopus vourus. Posterior face ..............0.0ec sees Baie ifft3) Kuk AL
Hetopvus aispsposus. Posterior face and profile section......... 79

-) 80 ee

HeLopus 1iMax. Top, side and end views..................-

HuELopvus PLACENTA. Upper and posterior surfaces.......

HeELopvus pENTICULATUS, Side and top views, and profile section 81 Katara

He.opvus orENuLATUs. Upper and under surfaces BD oe

HeELopus unputatus. Top and side views, and section..... a

Hetopus anevtatus. Top, side and end views...

Teeth of different sizes and forms.
HELopUSs suLoATUS. Top and side views of small tooth........ 83 Rewla/K-

85 ie
nh

Cnromatopus? cosratus. Upper surface and section

WOOL. ’ rileV

TOL. 11
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PLATE Var

PAGE
HELopus consonmpatus. Superior face.................. 87 Au
Inferior face.
Profile.
A shorter tooth,
Under side of tooth.

HELODUS (COCHLIODUS) NOBILIS. Posterior face......
Superior surface.
Profile.
Series of teeth seen from above.
Posterior face of largest tooth.
Profile of No. 4. 4
Series of teeth found with Cochliodus nobilis.
Profile of same series,

Profile of series of smaller teeth from same individual ag No. 5

*

a

—a es

PL, VI

: CRSLERG CMEC EUNE SHEL: UE OR OR ES

CARBONIFER OUS> « Keokuk Limestone. | FISMKS.,

Western Engraving Co Chicego

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latus aa re Mele oh “My PAGE
CocHtiopUs, NOBITIS,)....... -Whuadg. ened th oo ckine bee ese erso
Terminal tooth of upper jaw,? lett side, ? upper surface.
Terminal tooth of upper jaw,? right side, ? upper surface. — soa
Terminal tooth of lower jaw, ? left side?
Profile of same.

Terminal tooth of lower jaw? right side ?

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PLATE Nii

. atus
Fig. 1. CoonLiopus lets Upper surface of terminal tooth...... 89

$ er =) ik 4 ) wh Fig. 2. ‘CoonLiopus ? ORASSUS. Upper BUISACE asian we eae nig
Lan wraaind 2a. Profile outline. re
Fig. 3, 34. AsPIpoDUS CRENULATUS. Most convoluted pair of teeth. bar 93 UO NA

4, 4a. Pair of arched teeth with more rounded outline.
5,5a. Pair of pentagonal teeth.

6,lla, Teeth of various forms.

Fig. 12, 12 a. ASPIDODUS CONVOLUTUS. Upper surface and profile section. . 94 : ba
Fig. 13. Poxomopus RuGOSUS. Upper sunrise: otis Wee: pies ae neice

Fig. 13. @, PoxroiLopts oRNaTUS. Upper surface...................

a =<? 2 Ss hh CU tt —— —_

AG SONA uM onary,

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3.

PLATE IX.

PELTODUS ANGULABIS..-

DELTODUS STELLATUS.

Anterior lateral? tooth.

3a. Profile of same.

Fig. 9.

9a.

i

DELTODUS UNDULATUS.

DELTODUS CINGULATUS.

Sach steihajae si anreraLe eee Skate ati

Posterior terminal tooth .....-+ Leo

DeLTODUS SPATULATUS. Upper surface

. DELTODUS RHOMBOIDEUS.

DELTODUS GRANDIS.
Profile.

Upper surface of t

Upper surface of terminal tooth... 99

of terminal tooth...100

Upper surface of terminal tooth..100

erminal tooth..... ..100

h 98 Berane) be nC

DELTODUS COMPLANATUS. Upper surface of terminal toot
Upper surface of terminal tooth... 98) Pawo,

hs 2 i Dal ee

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VOL. £1 Th. 1X

GRUCOGIENS SOY oF eer,

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PLATE X.

i
donne ne f, 4
; LOU als SANDALODUS PARVULUS. Upper surface....................102 eee wn 4 Vinee

la. Profile view.

Fig. 2. SANDALODUS) SPATULATUS!,....0( 0a. diuasaienr enya... nde ana 4

‘

: SANDALODUS ANGUSTASS., .n<cjon s-cmchencee dan snapesante wesc Oes Roel i

a
? SANDALODUS CARBONARIUS......00::c0sccersssneenntecnercerss LOA Cord W a

3

4

5. Larger specimen of opposite side.
x

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)

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; SAND ALODUS GRANDIS.0i.0:1.0ace5 1m auenaeeetaernee Mase ees ame yy

. ; Vin: ;
Fig. 10. Rinopus cALceous. Seen from above.............---...-.106 Hommdl ys Gro 4
10a, Side view. a

10. Profile section.

10c. Portion of triturating surface, magnified.

‘
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CARBONIFEROUS & DEVONIAN

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PLATE XI.
PAGE
PsamMopus porosus? Upper surface..........-: nebact te LOT
Side view.
End view in outline.
PsAMMODUS ANGULARIS. Upper surface.........+-+++++++ aoe hn
Side view.
End.

Psammopus nuGosus? Upper surface of small tooth......108
Side view.

PsAMMODUS SEMI-CYLINDRICUS. Upper surface............109
Profile.

PSAMMODUS RETICULATUS. Upper surface ........- Peroni)
Profile.

PsamMopUS? RHOMBOIDEUS. Upper surface.........--
Side view.

TRIGONODUS MINOR. Upper surface.....+.0+-s++ss+++ Se
Side view.
TRIGONODUS MAJOR. Upper surface.....+-..seseseeeererss

Opposite tooth, ditto.
Side view.

PL. XI,

CARBONIFER OUS> ( Sub-Carboniferous ) FISHES,

a Dr J S&S Newberry, del. A.H Worthen, divext. . “Western Engraving Co Chicago

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Fig. 1. Homaoantuus eiszosus. Side view—natural size................118 HL;
Fig. 2. LEPTAOANTHUS? OCOIDENTALIS.........0-eceeeececeeeccceesces s LG .
Fig. 3. QRAGANTHUS PNIGEUS é ciciy/e« sisic's ities «ince s ceel sper me recor atari Te Lae

Fig. 4. OrenacanruUs aNeULANIE........</+.0--+-1¢;teebaes, 6 aces a

4a. Side and posterior faces—natural size. . yf rc,

. 9 ,
Fig. 5. OTENAGANTHUS? COSTATUS .-- 02-222 0ee eset eee eeee eee eeese ees 0120 SL,

Fig. 6. Homaoantuvs? rgotus. Side view—natural size.................115 4
_ Fig. 7. DgeraNAGanrays? srersaTue...././..'..02.. du. daey se sence ee Rob

Fig. 8. DREPANACANTHUS ANOEPS .6 5 .02.ce0seceseonesootsccesenses cs 192 Cypleueie

/

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/ al

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j : VOL.11.

CARB ON TIF IR OWS \ Sub-( arboniferous })

LSS

ee

DEJ_SNewberry del A.H_Worthen dirext. Western Engraving CoG hicago

BGs yam Sth vay

Pavan oxalate

PAGE
DeEPANACANTHUS GEMMATUS. Side view..............-.....123
Section.
Tubercles, enlarged.
Base of another specimen.
CTENAOANTHUS GRAOILLIMUS. Side view...................-126
Medial section.

Basal section.
Bone of a fish, from Burlington group, Quincy, Illinois.

CARI CU LENE, STOLE Oe OO Os

CABIBON LERIR OS. © Sub Garboniferous ) PIS TiS.

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awe. ouderl

PLATE XIV.

PAGE

Rig. ae SPHENOPOTERIUM ENORME, M. and W..........-.-:eeeee ences 146
la. Lateral view.
1b. Magnified view of surface markings.

Fig. 2. SPHENOPOTERIUM ENORME, var. DEPRESSUM, M. and W.......... 146
2a. Lateral view.
26. View of summit.

Fig. 3. AOTINOORINUS PISTILLIFORMIS, M. and W...........-.-+..----- 151

Side view of body and vault, without the base and proboscis,

Fig. 4. RAYNOHONELLA MISSOURIENSIS, Swallow..........-..- Searice oS 153
4a. Front view.
46. Ventral view.

Fig. 5. SPIRIFER COOPERENSIS, Swallow.........-...-.-- Eepnany sists ge 155

= 5a. Lateral view.

5b. Dorsal view.

Fig. 6. GCARDIOPSIs RADIATA, Menand Wi .2is .5;5 scicclas cles alee healt 157 2
6a. Side view. ’
66, Front view of right valve..

Fig. 7 STRAPAROLLUS LENS, Hall, sp.......... bia Migheik e miehsiacnie eee leno 159
7a. Side view, showing the outline of the aperture.
76. View of the upper side.

Fig. 8. BELLEROPHON OYRTOLITES, Hall..... dkeaaodas dedesoccocsat sn 160
8a. Side view.
86. Dorsal view.

SO oie Navtitus (Zrematodiscus) pigonus, M. and W...... side Saleeere ss 163
9a. Dorsal view of small specimen.
9b. Side view of same.
9c. Section of one of the whorls, showing the siphuncle.
9d. Dorsal view of a large imperfect specimen.
9¢. Side view of same.

Fig. 10. Navritus (Zrematodiscus) trisuLcatus, M. and W....... FG coo 162

10a. Side view.
104. Section of the outer whorl, showing the position of the siphuncle.
10 c¢. Dorsal view.

Fig. 11. Gontatites Lyont, M. and W.................++- jp tisiaire sinus 165
ll a. Dorsal view of internal cast.
116. View of one of the septa, slightly enlarged.
llc, Lateral view of internal cast.

OU LLNS

(Kinderho ok Group ) WES CH bIhAI IK OW 8

+
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Fig.

PRATER AV.

STEGANOORINUS ARANEOLUS, M. and W........--++eeeeee eee 198
Posterior view of the body, with the proboscis, free rays and arms
broken away.
View of under side of same.

CYATHOORINUS SOULPTILIS, Hall?..........------2-- eee aac hs)
View of under side of body.
Posterior view of same, without the arms.

Actrnoorinus poproaDAoTYLus, M. and W.....--.--++-+----:- 205
View of posterior side of body, without the arms or proboscis.
View of anterior side.
View of under side.

AMPHORAORINUS SUBTURBINATUS, M. and W.......------++---> 212
Posterior side of body without the arms; showing the anal and arm
openings.
Anterior side of same.
GiLBERTSOORINUS FISOELLUS, M. and W.......-+---++-++2++-20> 222

Side view of body, with all the appendages broken away. The true
arm openings are seen over each division of the rays, and those of
the false arms over the interradial spaces. ~

PLaryorinus suBsPinosus, Hall.........------ Sieloie ie mistelacetners 173
Under side of body and arms.

Acrrnoorinus soirutus, M. and W....-.------ ---+-sseere-s 202
Anterior view of body, with arms and proboscis broken away.

Posterior side of same.

Aorrnoorinus astertsous, M, and W....-.---------+--- eaeree 207
View of summit, with the proboscis and arms broken away.

Posterior side view of same.
View of under side of same.

ActINnooRINUS CoNCINNUS, Shumard.......---+--+sserseeercee 200
View of anterior side of body, with arms and proboscis broken away.
Posterior view of same.

Caoorinus concavus, M. and W.........---+++eesserter ee: 215

View of under side of body.
Side view of same without the arms, showing the minute arm openings.

View of opposite side of same.

CARB ONIFEROUS (Burlington, Limestone ) CRIN OIDKA

je

E_B. Meek. del. AH Worthen .darext Eng. by Western Engraving Co. Chicago

SEOLOCIOAL SURVEY OF HLwInVOTS, =

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As “Lo wsly 4} ofagT

PLA DOV:

PAGH

AVIOULOPEOTEN BURLINGTONENSIS, M. and W............--.----281
View of left valve, with surface partly exfoliated.
A portion of the surface, magnified.

Zeaorinus Troostanus, M. and W..............---20eeees--- 186
Body and arms entire.

PALAOHINUS BURLINGTONENSIS, M. and W........ Baobancadanss aa
View of a specimen, showing a part of the ambulacral and inter-ambula-
cral plates.

An enlarged view of a part of one of the ambulacra, and the adjacent
inter-ambulacral plates on each side.
One of the surface spines, magnified about three diameters.

PorERIOcRINUS SWALTONEY Mand. Wi «..\sietvs sseanirdaarerec ts OS
View of anterior side of body and arms.
View of posterior side same.

DioHoorinus conus, M. and W.........265 weeccceccceeses--- LOO
Side view of a specimen without arms. ,
Posterior view of same.

STROTOORINUSREGADIGS .). SMa atals occ (oustaleve nlere eile stele Seats alevetoteresnerse stage
Anterior view of the body, with expanded yault and arms broken away.
Posterior view of same.

4% 4 PI18.
| SUL OCGA, SOIC Ole UG) i epics
CATR DWF OWS (Burlin pton. Limeston e) CRIVOMMEA & MOLILWS CA

2 saa ae aE

Western Engraving Co-Chicago

AH Worthen dirext

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PLATE XVI,

PAGE
SPHENOPOTERIUM COMPRESSUM, M. and W..................234
Side view.
Magnified surface markings.
Profile view in outline.
SPHENOPOTERIUM OBTUSUM, M. and W............ eee OO
Upper side of a large specimen, with nine cells.
Profile view of another specimen, with four cells.
Upper side of same.
Magnified surface markings of same.
Under side of specimen, with four cells.
Onycuocrinus Norwoopt, M. and W.......... eae Ses

Anterior view, showing the body, with portions of the rays and column.
CYATHOCRINUS ANGULATUS, M. and W............-.-- +0000. 234
Side view of body (distorted) and portions of arms.
CYATHOCRINUS SAFFORDI, M. and W.............2.2s020+0e00-200
Anal side of body, without the arms. -
Under side.
ScAPHIOCRINUS DECADACTYLUS, M. and W..................238
Side view of body and two of the arms, with fragments of other arms.
OnycHocrinus Monrosnsis, M. and W............sse000062-244
Side view, showing body, arms and column, with the small finger-like
series of anal pieces in their natural position between the two poste-
rior rays.
OLiGoPoRUS DAN) M. and W...:.<.c0+ «aus sueeeseee aaeeeeananee ee

Side view of a flattened specimen, showing two of the ambulacra, and
the large inter-ambulacral plates filling the space between.

GEOLOGICAL SORVEY OF Weer ors
CARBONIFEE OU S (Keokuk Limestone)

MITES (CIES ths IL) AON TK D1 St

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Dorsal view.
Ventral view.

Surface markings, enlarged.

Outline section, showing the arching of the valves.

AVICULOPECTEN OweENt, M. and W.................0:. aha 256
View of right valve.
Surface markings, magnified.
Outline profile view of right valve.

AVICULOPECTEN OBLONGUS, M. and W.............--..55 pian AOS
Left valve.
Mould of same in matrix, without the hinge margin.

AVICULOPECTEN AMPLUS, M. and W........... ye see 257
Right valve, showing the deep sinus in the margin for the passage of
the byssus.
Ligament area.
A large left valve, with surface somewhat worn. The dotted line
showsthe position of muscular scar, as seen in another specimen.

ZRACRINUS PLANOBRACHIATUS. ...-.yes-ccccccccnesucesscrseoneeQtO
Side view of body and arms.

PLEUROTOMARIA SHUMARDI, M. and W.............. i emer eOU
Side view showing the aperture.
Opposite view.

CAMAROPHORIA SUBTRIGONA, M. and W........... begat ogee 251

View of ventral valve.

Profile view.
Front view.

ATHYRIS PLANOSULCATA, Phillips? (sp.)......-.-..+.- Sadak 254
Profile view of the two valves united.
Dorsal view of same specimen.
Dorsal view of a larger specimen.
Ventral view of last.

aw

cigtohentnkts PL.1¢

COLD) SUGGS OU 7S Oe UG bi Oy iisy

CARI OD WP IMI OW Ss (Keokuk Limestone ) CRIN KA & MOOI CA
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PLA PE xT.

SPHENOPOTERIUM CUNEATUM, M. and W............... sesso 22
Side view of a specimen containing four cells. —
Profile view of same.
Side view of another larger specimen.
Enlarged surface markings.

DicHoOcRINUS CoNSTRICTUS, M. and W............c...05- peace 2A os!
Under side view.
Anterior view of same, without arms.
Anal side of same.

MYALINA concenTRICA, M. and W......... RCE hia supe Ok
View of left valve.
Anterior view of same.
Enlarged surface markings.

STRAPAROLLUS SIMILIS, M. and W.. ....... Burda foc OS.
View of upper side.
Profile showing the aperture.

STRAPAROLLUS SIMILIS var. PLANUS, M. and W............286
Upper side.
Profile showing the aperture.
View of umbilicus and under side.

PLATYCRINUS PENICILLUS, M. and W....... Doda eteniooreneeane 266
Specimen with arms, column and tentacles attached.
Part of column enlarged. \
One of the segments of the same.

ScH@NASTER FIMBRIATA, M. and W........... MP hon GAs)

View of a nearly entire specimen, dorsal side.

Enlarged view of one of the rays, showing the arrangement of the pieces
and pores, as seen when the surface is ground down.

Under side of same, showing the oblique arrangement of the adambu-
Jacral pieces and the intervening ambulacral furrow, which latter is
proportionally much too broad, in consequence of compression.

Under side of an imperfect specimen, natural size, showing the adam-
bulacral and oral pieces, without the disc.

DENTALIUM VENUSTUM, M. and W.......ccccccceceeneeee ener 284

ECROLOCICAL SHNVEY OW Wb woos. *

CARBON IRIE IR OWS (Saint Louis Limestone)

'S.-4)

EB Meek & Mrs. Myers: del. AH Worthen. dirext.

MIS CIB LhANIE Ow

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PLATE) XOxe

Fig. 1. GRANATOCRINUS coRNUTUS, M. and Mos erosos haste 276
Side view, without the arms and column, ey

Vig. 2. Piarycrinus Prarrenanus, M. and W.............:0.00.-- 264
Side view of body and arms. ;
Pe Vig. 3. PLATYCRINUS PLENUS, M. and W......-.0.0-.00006 cee ee
Deis . Showing body and arms, with a portion of the column.
Fig. 4. TAXOCRINUS SEMIOVATUS, M. and W......0.0h:.0s0sc000e00e 19% 72

4a. View of a specimen, with arms and column attached. Lee,
46. Enlargement of one ray of same to the second bifurcation.

Mera. - Propuctus scrrunus, M. and W...........-01.-.00+ eee

5a. Profile view (strie too coarse).
5 6. Enlargement of striz. pee
5c. Ventral view. t : ‘
ot 2 Striz too coarse.
- ; 5d. Front view.
nat Fig. 6. Nucunana curva, M, and Mesdincoidncrieata gale
ed F 6a. View of left valve. =
f! 6b. Surface strie, enlarged.
<a fe Th YorupIA? vevisrrrava, Moand Wo.....-c--nsete tue eens
a ‘Ta. Left side view. ; ates
NA 76. Enlarged surface markings. —
a Fig. 8. ORTHOCERAS EXPANSUM, M. and W..........ccecereesereee 286

8a. Side view of a specimen, somewhat flattened by pressure at larger end.

8 6. Section showing the expanded character of the siphuncle between the
septa.

8c. Section of the small end, showing the position of the siphuncle,

© Be

VOL. 11

CARIB ON IUME IR OWS

FB. Meek & Mre. Myers, del

(St.Louis Limestone \

A H Worthen, dirext

ins

by Western

SMS CE LLANE OUS

insravine Co Chicage

“

AXZ% APAII

vee. dvOTT .e10ame AdoTrICT
-oxla letpta
Papen Bar oblgenersiitog Yo Ieamog alot
20 or {BO dizx lq oats o98) tuor @atiovera A1090,10¥0
moodsigqa 10 vlog aah, od Waievos ,osie lerudin hrontioogs & lo wsiv ebia=/
( pe ety 4 Hla -bia sobau odd to
10 moitrog 4 to larGates Td owode ex ,sost1e eoistisog Lote meg al Ay
sat ack .oloa odd

eee g mee ee ee SDOTH ABAIIIGH anosrvsoed ’
ovis (rivjan abia enoitiiog 1a wort

4 bodingemy emixe

shie siieeqan orl Io Snooron iad

Peewee HOUT ,anaowy.10t Anodo10YO
: reste Issudnn gbia asorstirog-nowl
i: -bottiagsm mee

boitingao shia sso1stited

WE orl aiacaxoriaman wAOFEION
sie Intend obie ibis to wei¥

nstog odd guiworla bie stizoqyo Io woiv belingalt

PLATE*X XI.

Re PAGE.
max Vig. 1. Ponyrors GRAommIs,) Prout. 6: 00.5. .teony. 0 dene an eee
Petal 1. Natural size.
la. Enlargement of poriferous side.

Fig. 2. CYoLoPoRA DISCOIDEA, Prout. (See also, pl. xxii, fig. 10, 102)...420

; 2. Side view of a specimen, natural size, covered by the sole or epitheca tr
_ of the under side.
= . 2a. Enlargement of poriferous surface, as shown by removal of a portion of
Ei. the sole.
Fig. 4. Ponvrors PArrIANA Prout, 0.5che cans oot en aera .
4, View of poriferous side, natural size. ‘
4a. Same, magnified. } £ ~

4b. Enlargement of the opposite side.

Fig. 5. @YCLOPOEA FOLYMORPHA, Prout,.2oeeence as eae eet el
5. Non-poriferous side, natural size. nf
5a. Same, magnified.
5b. Poriferous side, magnified.

Fig. 6. POLYPORA HAMILTONENSIS, Prout... . 00.22. 0c ws. een eee oes vse edee.
6. View of under side, natural size.
6a. Magnified view of opposite side, showing the pores.

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deen ++- SOL ob Ema (BA. VMinIOKOD.
in Pate (aru be 9 Erte auosetings

Foie tte tee er se... d01F evar A Anat wUIDROD
tte lninten si fiage epétetinad

~ Boitiwanc 29T0g ot Stig. eolqarih ant to on)

‘10 t+ AMG e ot... SOIT phat ANOTO.I9F0
. osiz lainien ,obie vahas odd gatvode samtooge

t j snrne to mints ooKttee,
botirgent tadwoooe obi stizoqqyo no esto
HUSE. . (wk Sonit ARE Aq ols 994) .torT -anaiopnia asoqo10xD
93iz laaniae Tynomivega 6 10-obiaszebntl
EyG) 16 avend ods Yo bons TAIGHR ond anions inne’ to sortase Dogialo ot
‘" #0ottiqg at Mguords 1598 ee ,zo700

~%

[

Fig.

Fig.

>

Fig.

roo)

PLATE XXE

PAGE
CosointuM WoRTHENT, Prout... 2... .0. 22. sees sneevecenee .. 412
View of specimen, natural size.
Enlargement of a part of surface, so as to show one of the dimples and
the pores.

CosoINIUM ELEGANS, Prout............ Siolaipiaislsrereiete hier teree trees 413
Poriferous side, natural size.
One of the dimples with the surrounding pores, magnified.

CosoInIuM PLUMOSUM, Prout ................ccseeeeeeeeeees 414
Specimen showing the poriferous surface, natural size.
Opposite side, showing the cup-shaped cavities, natural size.

One of the dimples and the pores, magnified.

Coscrnipm Micueninta, Prout. + cu eek seineee seieelnte aaer 414
Specimen showing the poriferous side, natural size.
One of the cup-like cavities, enlarged, showing the dimples and the
surrounding pores,

CoscINIUM SAGENELLA, Prout........---.00-eeeceeeceeee eres 415
Specimen, natural size, showing the cup-shaped cavities and surface
pores.
One.of the surface cavities, enlarged, so as to show the dimples and
pores.

CoscINIUM TUBEROULATUM, Prout......... OCOD OUCH SONGAS Od 415
Specimen showing the dimples and pores, natural size.

CosoInIuM ASTERIA, Prout..........-.-. bodconodeos Saletan 416
Poriferous surface, natural size.
One of the star-shaped dimples, and surrounding pores, magnified.

CoscINIUM ESCHARENSE, Prout....... Santee (avctacereiere ak elorepel oval ote Sree 416
Poriferous surface, natural size.
One of the dimples, with the pores, magnified.

CyCropoRA MUNGTAY ETOUts yo eiels)ercleitelefoletteter reread ete etait 419
Specimen showing the under side, natural size.
Surface strie of same.
Pores on opposite side, somewhat magnified.

CYOLOPORA DISCOIDEA, Prout. (See also, pl. xxi, fig. 2, 2a.)....420
Under side of a specimen, natural size.
Enlarged surface of same, showing the appearance of the bases of the
pores, as seen through the epitheca,

Plate

VOL_II-
CROLOCIGAML, SWEENEY WL MLL nous:
Papeete race an ci « Kookuk & Stouts I imestone.) eras

10@
Aug it
a8,

Phil_M_Springer del- AH Worthen dirext. Western Engraving Co_Chicago-

a”

MUX BTAIA

iriakiek ins 8, ht a bua M fisaaaaresny aa ammoorerer th
ei 10: baosyid Jail page) teaian gate iw cominaqe « to, wel?

th {
onad gerieodte
fidsiox how Jend bay ieee adh to Duidsienoo jzbhod ad) Ya

Infos det! his’ Usbtat Te hao 99a ou} dtiw todieyot 4, i

efits od} Jusultivy

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E 5 pha ING Me
aon. sev Mein bans

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at Stair oli Pita enone Galina 1 aAd0 woivohie volv9isoF

We
_ i

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si a » paola DA hey ‘panies wing otto enO yf
aaa odo to weie Sombie doa 41) 2v ino. ¢ ogeateathe A

‘woes alt] [eds nda ae i ands

Lie owt ald Yor orine ay ee es
ori Bhs ay a ve be

33%

Wie % ©

one ine yoy baw ose8101 2 an pee ce

WORT: Fistiiaus aii nat

PeUeAM eyes “145! urea

. W bas .M arenas widoaoa

raja ods yatworde dasoe Io wale 20iTobo dk

Ooms ot Io vrory Seistet

dt exihaivoonn ARIAT,
Seam Hiont ca pki POnetiyA

Fig.

Fig.

PLATE X XO:

PAGE
PTEROTOORINUS CHESTERENSIS, M. and W..........--- ---5.4..292

View of a specimen with arms attached (somewhat flattened by pres-
sure), showing base.

Anterior view of the body, consisting of the basal and first and second
radial pieces, together with the secondary radial and first brachial
pieces.

Anal view of the same, without the arms.

Prerorockinus orassus, M. and W..........---eceee-ee-eee-: 290
Specimen with the arms attached, showing the base and posterior side.
Posterior side view of the body of same, without the arms.

AROHZOOIDARIS MUCRONATUS, M, and W..........--..-..----- 295
One of the primary spines, natural size.
Enlargement of the fine surface striz of the same.
One of the interambulacral plates.

PRODUCTUS PARVpS; M.cand W.\\- sence = one cert Meee ieriereieen
Profile view.
Section showing the curve of the two valves.
View of dorsal side.
Ventral view.
Enlarged surface markings.

SPIRIFER GLABER var. conTRAoTUS, M. and W.................-298
Dorsal view, showing foramen and very small area.’
Profile lateral view.

SoOHIZODUS OHESTERENSIS, M. and W............2-00eeeeeeee+ B01
Anterior view of a cast, showing the anterior muscular impressions.
Lateral view of the same.

MYVATINAVANGUDATA HM r ANA Wh. .' -1ein eerie ciate lec etasiieieeie enya n OO
Anterior view, showing the broad, flattened surface formed by the in-
flection of the anterior margins of the yalyes.
Side view.

VOL. 11 PL. 23
COLO CTE SOLA fos.
CARBONIFEIROUS ( Chester Limestone } MIS CRLLANEOUS

ao

©
BE

FB Meek & Mrs.Myers del A H Worthen, dirext Eng. by Western Engraving Co Chicago.

wee, ow e ve “pean } swung? eter “adrienne
ee, = » ? ,

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tn KE vrgai9 eu ii dguvone qooh otk
yt

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_—_

5 8,

PLATE XXDV:

PLEUROTOMARIA OHESTERENSIS, M. and W...............-- Fee ani0h)
Side view, showing the form of the aperture, spire, etc.
View of the opposite side.
Enlargement of surface markings.

STRAPAROLLUS PLANODoRSATUS, M. and W..........-- sida ma DOI
View of upper side.
Outline profile, showing the form of the aperture, spire, etc.
Under side of a smaller specimen, showing the umbilicus.

ORTHOOCERAS ANNULATO-cosTATUM, M. and W...... aisrapaions reer B04 —
Side view of an imperfect specimen.
Dorsal or ventral view of the same.

NAUTILUS OHESTERENSIS, M. and W..........-..... spies iot Sitter 306
Dorsal view. re es |
Side view, showing the size of the umbilicus in the cast.

Navritus GLOBATUS, SOWerbY? ......-00eeeeecceeee reece eee = B05

Lateral view, showing the size of the umbilicus in the cast.

Dorsal view, showing the outline of the lip, the sinus of which is not
quite deep enough in the engraving.

: YOonu.1l.

p

ie End MS ASL SERVE OP WEE Oren Sa

CARBONITEEIR OU S> (Chester Limestone } GASTEROP ODA & CEPHALOPODA

57 e ‘

ober afer ie

e]

¥

AEA PAT

GG Ney Fie vedo in ciesarsveasane VE On AVITAL STIW ASAP TA

) @labs as to ehodw tonni 662 1 xomsiosge Bs bo wely elitorl

o's shoonigia oni lo nolti wee

eboilidmn odd yniwoie sarae Vinod 4
\

PLATE.

eal. NAUTILUS SPECTABILIS, M. and Was..s.-sssseeseeereres ere,

la. Profile view of a young specimen, or the inner whorls of an aint, na Y

showing the position of the siphuncle, etc.
1b. Lateral view of same, showing the umbilicus.

ss

.
GRUPO GEGEN STOLE OP oe opens.

CARBONE IR OUS. (Chester Limestone j Cc

SPH ALBPODA

Meek, del. A tis if

. &
i

a u aero

ea. aa WM uss: f avin kN ; :
’ te tos big soba
buh 2 to ohie rotisteoY _,

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. waly out ne ve ily
not o wsiY 2
am “WIV LaTovet- 908
i ateon to twoctogania iy

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ple oun amey Ato. Ate vy
eyoi alta 98} tise, bout me

as rn

A 2 tae Mt aD | Maroaqoa04y ies es
gat at teeieth OOF bar oytal oof qidgileoyeoD) .oviny Pr fall, ne 8
(. onivergite

ee, sc AE) hos PIATAOS VHUDEH AVIIAY NM |” “8
Hox to cllomelghisastitts Sithsastioy cite’: ovine ftofte aie rset Rigo ye

Pri

29 /8ote Yeni: TRS lao Tee’ orate Jolwseirm ont Ruinoile SABRE. “to obiens, oe
o=T9Dib vlkdmits * *tig ii golwods, boviny eovlev ows add tO waiy sotneig ix RI

gee Sty, eanod Tonpoxir -yminodo. less qo Tinie Wosiioe qo"

re Wo baa 1 BULAGK LET OT "Arosa ee a)

Soa 2 * Vaviayadaite v8

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GE és se Gitoenaabaencaeons's WE bar oT ATALGAS ‘eon a, Lie ee “er aii i
: | woTY iiotl > OL;

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‘Al earn tet ns ct anh eet Jue hg a oe = .

vahpundts st ddbhewyo:s ER wit cabal Si} Jo xsies 2970! Hel od? ep-ore at Pobylha nome one *
saat alii} ito ont Hoyatenia sw gotsog? owt THTOGR ofoleiy SO -OTO TRE LT,

a
i;
a"

Fig.

Fig.

Fig.

9*,
9a.
9b.

g. 10.

10 a.
10 b.

PLATE XRT:

PAGE
CYATHOCRINUS? SANGAMONENSIS, M. and W........ ...... 310
View of anal or posterior side of the body, without the arms.
View of under side of same.
ZEACRINUS? oraAssus, M. and W........... clus eh Fics gee lets 314

Posterior view of body to the top of second radial pieces.
View of under side of same,

ABAGRINUS, DISCUS, MM jamid Wa. casoancueedssean dace reine epmio ic
Under side of body.
Posterior side of same to the top of first radials.

Propuctus NANUS, M. and W.......... aeteelcteras eae secant 320
Ventral view.
View of front.
Lateral view.
Enlargement of costz on front.

AVICULOPECTEN PELLUCIDUS, M. and W............. Readeth 327
Left valve.
Enlarged surface markings.

AVICULOPECTEN CoxANUs, M. and W...........0068 daetenae 326
Left valve.
Enlarged surface markings of same.

AVICULOPECTEN INTERLINEATUS, M. and W..............- 329
View of left valve.
Surface markings, enlarged.

AVICULOPECTEN Kownincxktt, M. and W...............0.065: 328
View of right valve. (Coste slightly too large and too distant, in the
engraving. )
MYALINA RECURYVIROSTRIS, M. and W.............. RAPA h 344
View of outside of left valve, showing the imbricating lamelle of growth.
Inside of same, showing the muscular impression, cardinal area, etc.
Anterior view of the two valves united, showing their slightly differ-
ent convexity, small byssal opening, unequal beaks, etc.

STREBLOPTERIA TENUILINEATUS, M. and W...............d04
Right valve.
Enlargement of the very fine striz.
SOLENOMYA RADIATA, M. and W.............4- a enicapecc oon 349
Dorsal view.
Side view of partly exfoliated specimen,

* The figures here alluded to are on the left lower corner of the plate. By an oversight, in changing
figures from one plate to another, two species were numbered nine on this plate.

VO TT Pu
SHULO SICAL Swerys
CARD DA 1G mR ww s Coal Measures

mB Meek del - AH Werthen dirext Western Engraving Co Chics

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teow levee WY bon WM auvareoudtiua sso Rndoavad'L,

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Fig.

Fig.

PLATE XxVaiins

PAGE
1. MYALINA SWALLOVI, McC.............. isda « alll prem Mase E RRR eeseelL
ile Side view.
la. Dorsal view of an internal cast.

1. Dorsal view of another specimen.
le. Side view of same.
ld. Surface stria of same.
2. PLEUROPHORUS SUBCOSTATUS, M. and W.................00- 347
2. Side view of an internal cast, showing the muscular and pallial impres -
sions, as well as the impression of the long posterior hinge tooth.
2a. Dorsal view of the same.
MYALINA MELINIFORMIS, M. and W............-+.000- paises eae
Side view of an internal cast, showing muscular and pallial impressions. °
4-5 AVICULOPECTEN OCCIDENTALIS, Shum?.......... Babee Sakistetst 331
4, Internal cast of a right valve, showing the muscular scar, deep byssal
sinus, and the impression of the cardinal area.
5. Internal cast of left valve. (Cost not well represented in engraving.)
5a. Surface marking of left valve slightly enlarged,
tae EDMONDIA UNIONIFORMIS, Phillips?..............26 velas nee sO
6. Dorsal view-of an internal cast.
6a. Dorsal view of a left valve of another specimen, showing the impres -
sion of the cartilage attachment. '
6b, Side view of same.
7. ScHIZODUS|\————,, (Spi) soe eerne ene BA ene Up aepecada cacao 345
Side view of an imperfect internal cast.
8. TURRITELLA? STEVENSANA, M. and W...........sc0sceeseees 382
8. Side view enlarged. (Natural size shown by the line at its side.)
8a. Body and succeeding whorl, considerably enlarged, to show the sur-
face markings.
9. AT AOBUGNDAY, (Sp WMG), cpsel dea sceeeeceemaee n=. <ceene eatueeseOOW
9. Dorsal view of internal cast.
9a. Side view of same.
10. MACROCHEILUS, (undt.)............. miacelepiaeaceeie G93 sas IOSE 372
View of internal cast.

dptil, PrERINEA (MoNnopTERIA) GIBBOSA, M. and W....... we DAO

Ig View of internal cast left valve.

lla. Anterior view of internal cast of right valve, showing the lunle.

11%. Side view of the last.

. 12-14. Eumicroris’ Hawn var. siNuUATA, M. and W.......... 1.4, 338

12. Anterior view of internal cast of a left valve.

12a, Side view of same, showing the sinuous anterior margin.

12b. Surface markings of left valve.

13. Internal cast of a right valve, showing the deep byssal sinus and mus-
cular scar; also, the beak of the left valve rising above, with the
cast of the cartilage pit beneath it.

14, A cast of another left valve, differing somewhat in form from fig. 12a,

* The fossils figured on this plate are placed together, because they are all associated in a bed once
supposed to be probably of Permian age.

. br
K Poradynonitnrs .-

iat ; PL.2
CECLUGICAL SUNY ST OF TLLiyvows
“ OAIRTB © 39 1 IFW TR wT Ss (Goal Me asures) ’ MOL sis

F' B Meek _del_ AH Werthen dirext. Wester Engraving Co.Chicago.

: ws egnhnndh, sontiog io satecit hiogtalt
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PLATE XXVIEI. . sg

PAGE

Fig. 1. PLEUROTOMARIA BRAZOENSIS, Shumard?........c.0.c0000-304 Le Coto
la. Side view, a little enlarged, showing aperture.

1. Opposite side of same.
le. Natural size.
1d. Enlarged diagram of surface markings. ;
Fig. 2. PLEUROTOMARIA GRANULO-STRIATA, M. and W............356 ol. Cote
2a. Side view, enlarged, showing the aperture. .
26. Opposite side of same.
2c. Natural size.
2d. Enlarged diagram of surface markings.
3

Fig. 3. PLEUROTOMARIA TENUICINCTA, ] M. and W...........00006-:300 As Cot
3a. Side view, enlarged. :
36. Opposite side of same, showing (imperfectly) the aperture.
3c. Natural size.
3d. Enlarged diagram of surface markings. .
Vig. 4. PLEUROTOMARIA SUBSINUATA, M. and W........:..0c00000+ 358 < Cokin We
4a. Side view, enlarged, showing the aperture.
46. View of the opposite side of the same.
4c. Hnlarged diagram of surface markings.
4d. Natural size.

Fig. 5. PLEUROTOMARIA SPECIOSA, M. and W.......-.seccreceneeees302 oh - Culm
5a. Side view, natural size.

5 6. Opposite view of same.
5c. Hnularged diagram, showing the surface markings.
Fig. 6. PLEUROTOMARIA SUBCONSTRICTA, M. and W............... B51 ds Cop - mee
6a. Side view, magnified, and showing the aperture.
66. Opposite side of same.
6c. Natural size.
6d. Diagram, enlarged, showing the surface markings, spiral band, etc. .
Fig. 7. PLEUROTOMARIA PRATTENT, M. and W.......-.-s--.-+e0e-0 357 1. Cat
Ta. Side view, enlarged, showing the apertiine and the sinus in the lip.
7b. Opposite side.
7c. Natural size.
7d. HEHnlaiged diagram of surface markings.
Fig. 8. PLEUROTOMARIA TURBINIFORMIS, M. and W..............- 359 Us Gd =m
8a. Side view, natural size.
8b. Opposite view of same.
8c. Diagram showing enlarged surface markings. ;
Fig. 9. PLEUROTOMARIA ScITULA, M. and W........ beteeeeesseeee BOB tt Cosham
9a. Side view, enlarged, showing the aperture.
96. Opposite view of same.
9c. Diagram showing surface markings and spiral band.
9d. Natural size.
Fig. 10.* PLEUROTOMARIA SUBSCALARIS, M. and W...........066044:360 do Coloy
10a, Side view. {
10 4. View of opposite side, both natural size.

* The error in the numbering of the figures of this species, mentioned on p. 360 of the text, was after-
wards corrected on the plate.

VOLAIL. GEOLOGICA I, Sip pay Va a, WW Gh if 3C3C, a dba dt NOUS

i
CARBONE R OVS Coal Measures GASTHOF WM IDA

La 2a Ya ae ae

ed

————4

Onborn. del. A_H_ Worthen. dirext. stern Hnugraving Co. Chicapo-

Algor ods Sea ah #8 08 bevonter

.W bos WM eieuatousnuas eoxurrvaVl
to Iled dugde to Jaro lantaiti 30 obie latins ¥
; omine oil) to waiv obia
Blt oid Yo oniliso ond guiwode soijode
: \ -olonaugie

BOB nar rie eta. et wdig eri NY OLS: M PIMAOUATOAAIT BISITT.A VE
o} a8 o@ fevowsi ade Isntoiuo ons Adin (jend.dostieqmai as to woiv obit
ge i -piqe8 oot wore

{ ; ¢ parse Yo ,sniliuyooni, woiv olfor4

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eloaudgia od3 to coifipg bas gsie od? hag lotr

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an ee
RS tale

PLATE XXIX.

Fig. 1. STRAPAROLLUS UmBILIoATUS, M. and Ww. WOOO TIS GACT OH eHibeo Ge.

la. View of the umbilicus and underside. : Me

1. Side view, showing the elevation of the spire.
ple View of upper side.

:

eee! (he

Fig. 2. _ Cyrroceras? pinaratum, M. aid Wc o.

A specimen imperfect at both extremities, with a (portion of the shell
removed so as to show the septa. ; ‘y
Fig. 3. NAvrinus sANGAMOoNENSIS, M. and W................-- stenes 386

3a. Ventral side of internal cast of about half of one yolution.

3b. Side view of the same.

3c. Section showing the outline of ae whorls ana the position of the
siphuncle. P

.

:

ae Fig. 4. NAUTILUS PLANORBIFORMIS, M. and W.......2- cescccccescees 386
4a. Side view of an imperfect cast, with the external shell removed soas to _

show the septa.

4b. Profile view, in outline, of same. By seh Me

4c. Section showing the outline of the outer whorl, the thickness of the ‘

shell, and the size and position of the siphuncle.

.
x

volL.ll.

*PL.29
SRULUSNE Senay oe weep

NN SS
, CARBONTEE ROUS. ‘ Coal Measures.) GASTEROPODA & CEPRALOPOMA
Het ae
ne

eT
ce

F. B. Meek, del.

A. H Worthen, dirext.

Western |

TT dld

ret

bas Mo wna easaporay)
B28 xolleine ont dtiyr agerivaqe to woiv 9 hie
bap nite soho oft to gaiilars of) gui
Gate Cee pat to

ne ee eS es ae

)
-
.
a
.

valle

ars

2,

ate

2 a.
2b.
2¢,

3 a.
5} (Ds
3 ¢.

Profile outline of same.

PLATE XXX.

PAGE
CYRTOCERAS CURTUM, M. and W......-.-- .0-.seeceneeeeeeeeee OBO
Side view of specimen with the smaller extremity broken away, show- ‘
ing the arching of the surface striz and lip, as well as the position We8
of the siphuncle at 5. eet

GoNIATITES GLOBULOSUS, M. and W......:-.....secccceee0-e 090,
Dorsal side, of an internal cast, showing the septa. ae
Lateral view. 2 es
Diagram of one of the septa. _ Yes er
GONTATITES TOWENSIS, Ml. and W .5...ccscans-s-55 eestor eee eee
Side view of an internal cast, showing the septa. ;

Diagram of the lobes and saddles of a septum, near natural size.

VoL... \ PL. 30.
CRUE CEE, STOEL EN OFF Pepe Oren.
CARBON TMAROUS, ‘ Coal Measures.) CEPHALOPODA ,

ee

: ‘F, 6. Meek, del AH Worthen. divext. Western Enéraviné Co Chiez

ie. 12.

12 a,
Wor
12 ¢.

ig. 13.

13 a.
13 6.
13 c.

14.

14 a.
14 b.
14 ¢.

Pals

15 a.

15 b.

g. 16.

16 a.
16 bd.

PLATE. XX X1.—Continuep.

PAGE
LOXONEMA MULTICOSTATA, M.'and Wiivi. i.e eee scenes BUS
Magnified side view, showing the aperture,
Opposite side of same.
Natural size. __

LOXONEMA CERITHIFORMIS, M. and W....csececeees vesesees 79
Side view, showing the aperture, with lip’somewhat broken.
View of opposite side, ;
Enlarged diagram, showing the arching of the lines of growth, and the
crenulations just below the suture.

ORTHONEMA SADLER M, ANd Woerryayeeycfeocscessescceches BBL
Side view, enlarged, showing the aperture,
Opposite view,
Natural size.

SoLENIscus TYPICUS, M. and W.......0306.Jeaeddaes.. 00h ds... O04
View, natural size, showing the aperture, canal, and the fold onthe
columella.
Opposite side.

BELLEROPHON CRASSUS, M. and W.......00 cesevees seeeeee es OO0
View showing the ‘aperture, spiral band, etc.
Lateral view, showing the small, nearly closed, umbilicus, and wrin-
kles of growth.

Fig.

7

10 a.
10 b.
10 c¢.

ll a.

11 3b.
lle.

fond toss | Ana Dd
= 8

“aA

POAT EX XX RIT AL

PAGE

PLEUROTOMARIA? TUMIDA, M, and) Wyy...... siaaiemealt 0,361
Side view, showing the form of the aperture,, 4/); i I
Opposite view.

Naricopsis noposa, M. and W.......:28684 JAmiat,..ASf..366
Side view. : 10 AMG : if
Opposite view, showing the aperture Si the lip partly broken.

NATIcopsis NODOSA var. Hontrpayy, Mivand Wi....3.5.).. 367

Side view, showing the aperture — flattened ‘columella:
View of opposite side.
Narrcopsis NANA, M! and W AMILOUTAO...... er es!)
Side view, enlarged: 7 Woy | wt
View of opposite side, showing the aperture, which ‘is’ too Been
rounded within above, in the engraving. -OS1@ BARN

y ; =
.

Natural size. NW ie fh BUDETY - tl a

MAcROCHEILUS' MEDIALIS, M. and Wi 28.8 00..-8.45..3870
Side view, natural size. ME
View of ovposite side, showing the aperture and transverse stric on
. the thickened inner lip.’ (The-columellaandyinner lip above itjjare | |
shaded so as to appear too much as if flattened, on a plane.)

MAcROGHEILUS INTERCALARTS; M. and Wein otal B71
Side view, natural size.
View of opposite side, showing aperture.

POLYPHEMOPSIS PERACUTA, M. and W.............. Pe gene Oe.

Side view.

Opposite view, showing the aperture, with the lip broken. (The broken
outer lip, which was merely restored in outline, is made to appear
unnaturally thickened below, by the shading in the engraving; and
the inner lip is carried too far up.)

PoLYPHEMOPSIS INORNATA, M. and W........ escapees 374
Side view, enlarged, showing the aperture, with the lip broken.
Opposite view.
Natural size.

POLYPHEMOPSIS NITIDULA, M. and W................00ese00 374

Side view, showing the aperture, with lip broken.
View of opposite side.

LOXONEMA SCITULA, M. and W.......... “aaah Ma Pec ronda 377
Side view, enlarged, showing the aperture.
View of opposite side.
Natural size.

LoxoneMA RUGOSA, M. and W........... poaaagssace Samed 78
Enlarged side view.
Opposite side of same, showing aperture, with lip somewhat broken.
Natural size.

Oy CB cant

vy

F_B.Meek & A_Schénbom Del. A A Werthen® dirext Western Engraving Ge.Ghicag

Yee bare way oe aD Nii ot ioe
ihe a 09 & nb au oan lh Yo. nay Bergh an 10 wil
; pail 1 eriren 91} YO Jaamey rating nae
: Se ke Levey os ad: aA a agitate
hon hosts) old dtiw .ronsiosqs ottoe ylapit #10 9abe thor93o1 a8 to wail
agian te Ee bdtbiaps ahyailea, MT Neoy ast to om08
ah LO Ho store oul tioidwai mae silt to wiv olitorg sniltmo pk
Aiigve xia odd to ban jeegod)- clsdgeo old to shia 1nivetsog atli io
2ontl hostob mi beioites esle ais »xevod) oi to
a Pereererivieee W bos DD XARHTAA ATM ADOMIAT
Rens At onstanos gtlnye 2 ol oooh 86 extn [ntdan liegeot odj to wail
. oS ee ee We baw: M 2h Asp, MOMRIATASAT OA
Mo dal an ,lisaoh oi 6 eisey Qoini gawd Seqorehain telesoiqmi oi to woi¥
, a :pailtv0 ri be sewayi ai ia pone ge asi aay ppolsersaus a iit
bers oh Builivo boyralat
A OORT AIG 3 adit To
ig i tit aloe mA
a
eaattiea oily
iit tO. as xorg 4

A ihr, bilhy
of tl

ry eat ne mtty se
‘ PALO ATAT
rohan atolyste baa ee Ys ais it oi Ron a) ie weit
we ‘apyabuogan ee eae wagtre, ein ra
gil ot dure

} olrio dnt)
sein ods oe bY $i On es ee ; sei il bg ta Stofator 03), MowloT
paunate Agaigipte
: Marcie howioty 3
ohaernt gt a ! Aaa ipsavecace
oA Sa —...e fay Ye Sais nox: ieetead’
toiternos dt Pigiiel 2452 Bb", MaETAD YE Sto liad ao wSi¥ bhi A
yiciaisn oft hae Syst arti to ALT OH ide) Cutedy et alt Eten 11
~s.) edt Yo ono to nolsivis oko til Syoda Bab. aopphes niga. faciurbin
aad Kok) Ja drow witeliirtie, wat Atin.,aiplate

iniou HORST AL auiwotle fo sTsoqe wi fond oO im

waa lawitobas ale dy. yur Haya, vate Angted oft} Lo nenacolagn aitlinO , 8m pa
8 a, soba ‘ K ,
isle oj Lo ato, bo! i asikinpoee silat + Pa, Vaginas yal) ke nent

(Gi aotamih & auods hikari only? atic fo rl

é
desl add ti esq Jespt Hol ee VePray nee Pdlitonoleraienp apitinnA 478
odd ci gvvilyt ot nonnon ovis 7 88 oda D7 abalite bit} Io afaio(
A ‘ 4 : * : JSBao
Hayods od od su Eat siiiba rt otbinl: pol pais Feds 10 on0. —b &
; 1 MH GHrwo oP to aur WiokIxe ti Hy
to.ow! no atone nat aieas i Naw odd lo Hoh Ya inUago hogs lake’ > 9°
heiniog a ni odg ain Paeay ‘bebo ofBUD Lit ajo} fanfoCl Ataio, Bud
va i e out Sd tenor Ont due aulytonb k
se ) . ..mtos Isargi any bh wie awh Sis" oy, ne bt Pogardsa wwiireiiees nocspolt. Aare ‘gi
eae cS aA Rm cc) te homed AOBIATGUr ADA J gil ee
itd 1 aoargat Miwa ehod bia sgebde se” bine tei any (abaMige:io9qs 10 . silt
oalet add Se nuitroyis Dita eloltis 4h spin dale angtins regal oda} Wee . i
a apt se Saris rere AAMC. pi tp. aInGwA ho 8 il oS ai
iAoiternada s Fo tel Odes Hi i900 GH ids Hoge Mo verROe « Qaids baer ae et ;
by A) 90 nib § bogndtes De ae th
‘ in

Fig.

Fig.

Fig.

ww Re ee
= °

vo

pe

6 a.
6b. |

PLATE XXXII.

PAGE

ANTHRACERPS Typus, M. and W........ nan dlebjevaciibieniseesistaaieneal GG)
View of an impression of the fossil left in a concretion; natural size.
An enlargement of the same.

BELLINURUS Dana, M. and W......... .csesesee vais watote eee 395
View of an internal cast of a nearly entire specimen, with the telson and
some of the posterior margin restored.
An outline profile view of the same, in which the projecting appendages
of the posterior side of the cephalo-thorax, and of the sixth segment
of the thorax, are also restored in dotted lines.

PALMOCAMPA ANTHRAX, M. and W...........-..020¢« vewewenoelO
View of the fossil, natural size, as seen in a split concretion.
ANTHRAPALZMON GRACILIS, M. and W.............0.0ceeee0 407

View of an impression, and some remaining parts of the fossil, as seen
in a concretion, the caudal appendages being restored in outline.

Enlarged outline, to show the serrations of the anterior lateral margins ©
of the carapace.

An enlargement of the three joints of the peduncle, and a portion of
the flagellum, of one of the antenne.

A portion of the flagellum, considerably enlarged, to show its minute
segments,

PaLMmocaris Typus, M. and W............. Reseaeuebaeerodace ..405

View of a nearly entire specimen, with the telson and stylets restored.

Another specimen, consisting of the body and caudal appendages with-
out the legs and head.

One of the small natatory abdominal appendages from fig. 5, enlarged.

Telson (incomplete at the extremity) enlarged so as to show the minute
marginal site.

Enlarged outline of the telson, stylets, and two of the abdominal seg-
ments—from 5a.

ACANTHOTELSON STiMPSONI, M. and W.............2s0+000--- 401

A side view of a nearly entire specimen, as seen lying in the concretion.
It wants the antennz, some portions of the legs, and the natatory
abdominal appendages, and shows but one division of one of the
stylets, with the similarly formed telson above.

Another specimen, showing the antenne.

Outline restoration of the telson, stylets and two of the abdominal seg-
ments, as they must appear if the second or last joints of the stylets
are not double. (Enlarged about 2 diameters.)

Another restoration of the same parts, as they must appear if the last
joints of the stylets are double, as we have reason to believe is the
case.

One of the thoracic legs, enlarged in outline, as it appears to be, though
its extremity may not be complete.

Enlarged outline of one of the anterior legs, showing the setz on two of
the joints. The last joint of this leg appears to terminate in a pointed
dactylus, but this may not be the case.

The telson, still farther enlarged, to show the two sets of marginal sete.
ACANTHOTELSON INZQUALIS, M. and W............0+ Sogo 403
View of specimen showing the head, antenne and body, with fragments
of the legs, but wanting the stylets and a poition of the telson.
AMPHIBAMUS GRANDICEPS, Cope.......-....+ Srquicaasetins econ) 135

Representing a nearly entire skeleton, as seen in the half of a concretion;
enlarged 2 diameters.

ABO, Oy

CARBONIFREROUS .

FB Meek & Ad Ibbotson_

AH Worthen dirext.

IMU SS (CIB TILA 1 a

Western Engraving Co.Chicago

Ieee ATA

i \ i
E Ae ’

died anv aay iis eneTIosdaY

oh “C roitservga ynd woke inant: to! ataltngt Dinas! ad
‘ashy heaters 3 ftiw gO eit todnaad .

soy i! Mi bgsaha Tuan: palaoqu pMmiee edt VG disiteal oat

av Ht Rts in UNC ks erysiqplo yi

bowls CRE Oi) Ip .etolaiay

PLATE XXXIII.

NEUROPTERIS RARINERVIS, Bunb......... ...+-
Enlarged leaflets of the same, showing nervation.

Branch of the same, with a terminal pinnule.

Large leaflets of the same species, formerly placed in the genus
Cyclopteris or Nephropteris. Fea BOR ra ger

Veinlets of the same, enlarged

VOL._TI_

BEVLOCICAL SURVEY OF Wi ous

1. ve oh
CARIB OW WIE oD we ( Coal Measures ) WD 8 Sis WT tb eR A

|

theo Lesquereux_del-

AH Worthen dirext Western Engraving Co-Chicago

Bis pati ero a

Motsvian pAriode dingy ed) to jaiaol bay siall

LEX AP nah & &

ho? P
~ 4 K

(
hk

Srey cress e DUT Tyga Ae Best

hoins} worten bos hinges diiw yoithy A

(4 @uarIraunit agTELyadovamyl

iwode sms od? to deRaal bsyyai ad

Aon eceovise aiTilavndonamMeh

WT Iae yRiwode oat od Yo tohaol-hoyrslod

is ee a

PLATE XXXIV.

PAGE
NEUROPTERIS RARINERVIS, Bumb..........s0ccceeeee seneeeee 428
A variety with close veins and narrow leaflets.

Enlarged leafiet of the same, showing nervation.

HYMENOPHYLLITES PINNATIFIDUS, Spec. nov......005 666-436

Enlarged leaflet of the same, showing nervation.

HYMENOPHYLLITES SPINOSUS, Gopp.....s.cssssccseee seeeeee 436

Enlarged leaflet of the same, showing neryation,

.
\

P LL-XAXIV

a iy NS]

{rn ~ a,
DAUEIE OOM we, (Coal Measures ) MDSST LDA

Leo Lesquereax_del _ A. orthen dirext- Western Engraving Co-Chicago.

y VAX RII

a)
¢
%

29,.9°
en Sees

* 4 : vr '
Awa wekie FO .QG APOLIAD armaTtoogd

' erty Ronig to zodonard
inbayred guiwode ,otsee od Yo atoltes! hagitalatt

Af

Wreveres SPQ ATUCHIH aINTTIORUA
JoReel Iiswe *

Hehivibyleiaoleg eviooge smae oid to tofine.J

POO Atha to (aspiqoloy | walsol syrad

PLATE XXXV.

Fig. 1-2. SPECOPPERTIS CATMOSA, Sp. MON: onarein- nent) ahacma eens ee
Branches or pinne. . face.
la, 2a. Enlarged leaflets of the same, showing nervation.

a

Fig. 6-10. | NEUROPTERIS HIRSUTA, LsqX.......0cesecsseeseesrcacence
6. A small leaflet. ie
amy Leaflet of the same species, palmately divided.

8,9, 10. Large leaflets (Cyclopteris) of same species.

CRULUEUGAL SONYEY OF TLL

———

ea
by

’ CARR ON Lie owe ( Coal Measures ) KOSSTls PiLOrmA

Leo Lesquereux Del. AH Worthen dirext

Western Eng raving Co.Shicage

i
‘

PARR Ger Pal I

4

CU OSTA aaa ine Wf aisaTioTaodt),

Serrano de weise odt to ioe ie

TOU SGA ALPE Oo. AIBATTOTAOUU

tear ty

bE% Men dui Pema upaue sinatromuodO
OSD... Ween ei Sa 9q3 nov, aberina ia 7

Obbicccccccccccseee ee VOU .99q% AMHACY HOT ALAe EMORY

TEb evcceiececdeece-aeVOM 90q7 MUTATUOIAIL MULT IIOOIIAT -

PLATE xe,

i Opontopreris WorTHENTI, Spec. DOViessesessseesnsssessssss BZ
b, Enlarged leaflet of the same, showing nervation.

,

ODONTOPTERIS AQUALIS, Spec. nOV.....sc0cseeeeereee ree AB

il

2,

Or ODONTOPTERIS SUBCUNEATA? Bunb........-..000 Soc ACM
4

NEUROPTERIS HvENi, Spec. NOV...0..c0ccsnseseee-rcreseeeee ee 400
NEUROPTERIS PACHYDERMA, SpeC. NOV.......:s0eeeeseeeeeeee ABO
LEPIDOPHYLLUM AURICULATUM, Spee. NOV... sere ABT

$

ler
*
MOTs 11.

CAOLOEIGAL SUL OW TOLNOUS

TROD SSL Fs NAN

(OAC TRNB AD INTE TRIN TR a WT { Coal Measures )

A Worthen dirext NVestern Engraving Co.Chicago
Leo esquereux_del - AH Worthen dirext g g g

ind
‘

ae hed onde arses ouek fans A
‘ sinae odd Y Siam bye iota seein 4 Piney

cole

i" My >

PLATE XXXVII.

. PAGE
N&UROPTERIS VERBENAFOLIA, Spec. nV... eee ABI
NEUROPTERIS INFLATA, Spe. NOV.....c.cseesceeseeeeeseereee ABIL
LYCOPODITES ASTEROPHYLLIT#FOLIUS, Spec. nov...........447

ALETHOPTERIS STELLATA, Spec. MOViessesieseecarersvorers eA
4a, 4b. Bnlarged leaflet and spotange of the same, :

U7

VoL... : PL.37.

io t POUL OFF omen eres. }
CARBONTEEIR OWS.» ‘ Coal Measures.) FOSSIL MLORA, -
]
‘ \ ’
s _ ; .
. Western &
j

Te ART AIT Oy
rail ay arias ‘eigaranatAD)
ya ang ALON ty era)
sqshied to oR ood re a

‘aaa ose. oN ee iH sigandornodO™™; oae.c ot &

sesh berea hd Bnivode anne 6H I stefeal bo gieiat wd wes
Ps

ass ORY. Bipomwn, exormonrD 8 nd ax

jsvatyorsch. 01 bogieiad

Wisi,

la.

Fig. 2 to 5.
2a, 4a.

Fig. 6, 6a, 60. GYROMICES AMMONIS, Gop

Enlarged 10 diameters. Bape
Mapas oe Sho F ental ape -
} ‘ .

PL.88

GROLVCUCAL SWE EY OW InuLiKesy

CAIIB OI II Ew ws (Coal Measures)

IPDS Bs TPs RAN

Leo Lesquereux del +H Worthen dirext. Wester Emgraving Co Chicago.

LAD power aR cork. Seeizioniy: M

Dy OD) ATAIUYERD PaTIONTATA

W ; 5 d ah ” by nape * ‘V
Swarts es pie Sseopeeaile SyTa! TOR OT Oe 4:
7 c i - ’ * e Ys * z by
; ogee ott eenesl Soyintadl owe ye

Le HORM MoS .Thowtaa’

Laginhiyntensary i

Lavon 40 UREA BN EPO ATA

:

Tieiekgnals | oy te LL RAL) vam VON 0OG A ESCA CL CRIA MTT

HYMENOPHYLLITES ALATUS, Bret..
ALETHOPTERIS CRENULATA, Gopp.
SPHENOPTERIS RIGIDA? Brgt......

a, 6a, Enlarged leaflets of the same. biginal2"
HyMENoPHYLLITES CLARKII, Spec. nov

4

STIGMARIA E-VENII, Spec. nov .........eseeereeere:

ba

Ht

8. SELAGINITES CRASSUS, Spec. nov......
9.

a hones ale | >t30

GEOCOCLOCAL, SUWLNE Oe Wey nS,

CAR ONT OWS : (Goal Measures) FO § SIL WILORA

Leo Leequereux.del AH Worthen dirext Western Engraving Go

meters kIT

+40

%,

GREET en Ning FO 9qA RETO TUAGAM, AUIETION TAA
| ; ae hy

moter ysivwods stolssl bayralad wk ol

* , cet
‘-

Fig. 1-4, ALPTHOPTERIS MASSILLONIS, Spi
la, 3a. Hnlarged leaflets, showing neryation. —

2
; :
i »
j 1
“ *
:
:
; *
Wie yi

CAULOCIONL SURVEY OF

CARB ONIFEIR ous

FPO SSL IG DIA

Leo Lesquereux del-

i bs

sig Reeth Hoyt MurAERODSTO ‘ovoid
M nthe pil) Yo eolace bogialad

4 ibeyiqed bus .a1acg din aogaivogs ay poiuage Sinsa od) yidadort
i Ww a9igoe

ne e

¥

"3 £ .gi Yo 192 hogielal

Bs sissecn ee POR 0oq2, AUTAAHIOKY HarInInAIs

VON 09q% ,ALDOMULUAT slATTIOMmLT
aouatien goiworda .oatne 913 10 Jofteal hoytalos

Sera e eee wene eters

eh A

PLATE XLI.

LEPmorHnoyvos OBCORDATUM, Spec. NOV.........seeenes

la, 1b. Enlarged scales of the same. ie

2a.

Probably the same species; a specimen with scars, and depuieel of
scales,

Enlarged scar of fig. 2.

SELAGINITES UNCINNATUS, Spec. nOV.........0scseeeeeeeeeess AAG

SPHENOPTERIS PAUPERCULA, Spec. nOV......---seeeseeeseeers +435
Enlarged leaflet of the same, showing nervation.

op ia li Pua ge
CRULOTICAL SONNE OW nLLnnous
CARBON IIE ROOE ( Coal Measures ) i RD SiMe TAD DR A

-
‘
4
(
| S ‘
,
5 ¥
.
|
;
,
.
,
j
i juereux del A_H Werthen dirext Western Engraving Ca Chicago
= 4 Poe ys “ = . 5 5

. Vw _—h

%

A, GR OTe

LK 0 ; = 4 ay
’ at. = a

“leo KOM nage AM PPTROVON AMADA ©
; Hotaei here yet Saga Jit To poate Boqqr esovrey Dik

: RAO MIG

‘Fig. 1-5.
And various appearances of the
a. ; specimens.

Ca Wisc

>

VO ells FL. 42
ARURG OE GCE, SHA oe oceans.
CARBONTERIR OUS. ‘ Coal Measures.) FOSSIL FLORA,

*

OS

Nf
ee

A.H Worthen, divext.

~~ sn in soleil
Pete rai

i Wve ee

’ onl Me ageren j< oan

Pi tuee ee we Mee

FE
aa

OB) ile ; or aie yee ORT TOT ALEM CIR AAI TOL, &

ee,
rh ‘ p "4 ity. as Pe ;
OS. te past art abe

a SIGILLARIA MENARDI,
With scar of a branch. ;

FRYE UF CRATES.

CARBONIEEIR OVS. ‘ Coal Measures. )

FOSSIL IMLORA ,

el A ner divext Western
fA Worthen, d x

‘ tt

— ered

4

be. eron yea Ah voAoeso Abdevobdreastt

sabre Py

dey: uF ee eae o anibagooe ‘Saad YW Soo Hiesq ye woe

rt

mito a Wate ooORA boughs, YwanrnoW, wosara coat.

seething ay lig oy ae VO wage mur AMIS AT iT wosawmaoaraad |

¥ seit von oy i rated poaunmaoaTT

‘ 4
‘ 7

Fig.

Fig.

Fig

5

Fig.

PLATE XLIV.

PAGE

LEPIDODENDRON OBSCURUM, Spec. NOV........sseseeeeee woes 453
Various appearances of bark, according to age.

LEPIDODENDRON WORTHENT, Spcc. NOV........0+ ceeeeeeee sees 452

LEPIDODENDRON TURBINATUM, Spe. NOV.......0-:sc0sseeeeees 453

LEPIDODENDRON COSTATUM, Spee. nov...... dckinsesion Saha be 453

OT,.11

V

Sir

aN LORE

oP teepes

L

Va

SE.

sp Ost

Sub -Carbonif

st,

FLORA.

FOSSIL

al Measures

ta)

C

rous &

e

(

NFER OU Ss

RIBO

CAT

»

a ek ee

A

VIX Sor Ape

ui a Rei owt)
Wh 5, AOA S9: Be030) Lf
(or pik id Becate 5 yui
He Rio | ois"

Ady ome

‘ag tute ‘eosinhadbilboaT 3

MRE Sderot

h: >

PRA, XGUN:

PAGK

LEPIDOSTROBUS PRINCEPS, Spec. MOVssscserssserssserenssennse BB

(Two-thirds of natural size.)
Cross section of the same, showing the position of the Bp ORNE ee P

ing axis, and of the upraised blades.
Pedicel of the sporange and its blade, or Lepidophyllum princeps.

ig
LEPIDODENDRON SIMPLEX, Spec. NOV... .csseceesenec ees eee ee AD
. Leaves of Lepidodendron.

voL.l.

CARBONIFER OUS>,

Leo Lesquereux, del.

( Coal Measures.)

A.H Worthen, divext.

PL. 45.

SHRP OF Oe rer is.

FOSSIL ELORA,

Western Engraving Co Chic

CAmmagneRROUD., - § Qoal mPa ea

_ 0d BR ee von Log? iunnnian ponuwecoaratl
is ROR. + fll a: dareit Senn LAT TTT HUNTS. roqin
008. soneeeetes he “atk 7OU bag! Wekacoo. musa snononisT!

Pweg
ij) ee Taig ne ME “og PLETLANO8 aaah aur zos en)
TOR seo ssesees ti pete so dee HOM. Gane (uratO air y104a nD

rr oO. 9q@ MORE haere MusmacowooraT

fOb.....:..... eee seq, BUTALI SOAS ek HITTOU AD

h

Ta

PLAS, Xow ae

LEPIDODENDRON RADICANS, Spec. NOV....000 csecerereeeceeee edt
CARPOLITHES MULTISTRIATUS? Borne cieseenenensss6 Pe:
TRIGONOCARPUM JUGLANS, Spec. nov......... ae brant ee OD) ae
CARPOLITHES J ACKSONENSIS, Spee: gar ede ena
CARPOLITHES CISTULA, Spec. WOW eaten hesetteenecrss AGI
TRIGONOCARPUM ROSTELLATUM, Spec. nOV........s0000000+++.460

CARPOLITHES FASCICULATUS, Spec. NOV........ssseseereeeeee AGL

ES Se

VOL 11

CARBONIDEEIR OWS. ‘ Coal Measures. ) FOSSIL FLORA,

Ferrel Suse i

&

Ae ARTAU TS
>. ie

xis Lage

PEATE hw

Fig. 1. MEGAPHYTUM PROTUBERANS, Spec. noy.....
(One-third of natural size.)
2. Two sears of the same; natural size.

VoL.l1. PI
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PLATE XLVIII._

Mxcapuyrum McLayt, Spee. nov.............506.:
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Mage Cross section of the stem ; natural size.
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VOL.11

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