\^

f itologial Surtes of iljc ^tatf ai ftto Iflrk.

M/

PALAEONTOLOGY;

Vol. V. Part I.

LAMELLIBRANCHIATA

II.

CONTAINING DESCRIPTIONS AND FIGURES

OF THE

DIMYA^RIA.

OF THE

UPPER HELDEKBERG, HAMILTON, PORTAGE AND CHEMUNG GROUPS.

Br JAMES HALL, -a *). '^'7

STATE OEOLOOIST. ,,^— f^Zf^O

ALBANY, N. Y.:
CHAELES VAN BENTHUYSEN & SONS,
1885.

05

Statu of New York, \

Albany, November, 1885. )

Published -uniier the nupervisioii of the Trustees of the State Museum of Natural History, pui-suant to

rhii|.t<T :K5 nf tho Tjiws of 1883.

/

DEDICATION

To His Excellency

DAVID B. HILL,

Governor of the State of New York :

From the conimencement of the publication of tiie Natural History of New-
York, the successive volumes have been dedicated to the Governor of the State.
In accordance with this custom I have the honor to present to your Excellency
a new volume of the work, being the second one published under the provisions
of an act of the Legislature of 1883, being a continuation of the work on the

PALiEONTOLOGY OF THE StATE OF NeW YoRK.

This volume, together with one published last year, is devoted to the descrip-
tions and illustrations of the fossil bivalve shells known as Lamellibranchiata,
and completes the work upon that class of organisms. The two volumes em-
brace the descriptions of all the fossils of this class at present known to occur
in the higher geological formations of the State, viz. : The Upper Helderberg,
Hamilton, Portage and Chemung groups, with a small number from the
Waverly group, which has its chief extension beyond the limits of New York.
The material has been chiefly collected in the field, or acquired from collections
previously made during a period of more than forty years. The number
described in the entire work, from the formations above indicated, amount to
about 500 species which are arranged under 65 genera, and are illustrated upon
ninety-six lithographed plates, of which fifty-one are included in the present
volume. The number and variety of forms is believed to be greater than are
yet known from the geological formations of the same age in any other part of

iv DEDICATION.

the world, and the illustrations will compare favorably with any similar work

elsewhere published.

Hoping that this volume may commend itself to your Excellency and prove

acceptable to the students of science, and not unworthy of a place in the series

of works comprising the Natural History of the State of New York,

I have the honor to be.

With great respect,

Your obedient servant,

JAMES HALL,

State Geologist.
Albany, November, 1885.

TABLE OF CONTENTS.

Page.
DEDICATION iii^ i^

TABLE OF CONTENTS v,' vi

Erkata vi

PREFACE " . . vii-x

INTRODUCTION xi-xxii

SYNOPSIS OF THE GENERA xxiii-lxii

DESCRIPTION OF SPECIES 269-518

MoDioMORPHA 269-293

GoNiopHORA 293-306

MiCRODOK (Cypricardella) 307-313

NocuLA 313-324

NuccLiTES 324-328

Leda . . . . . 329-332

PALiEONEILO 333-349

Macrodon 349-351

Ptyohodesma 352-354

Nyassa 354-358

Grammysia 358-384

EUTHYDESMA 385-386

Edmondia 386-393

Sphenotub 394-406

Spathella 407-408

conocardil'm 409-415

Panenka . . . . • 416-425

Glyptocardia 426-427

Pr.«cardium 427

Paracardiom 428

Pararca 429-433

Cardiopsib 433

LnN0LicARDiDM 434-439

Paracyclas 440-446

ScHizoDUB 447-459

Prothyris 460-462

Soleuya 463

vl TABLE OF CONTENTS

DESCRIPTION OF SPKClKti (Coiitiimed): page

TKLLIN0P8I8 464-465

CiMiTARiA 465-469

Pholadblla 469-472

Phthonia 473-478

Orthonota 478-48S

SOLKN, p. O. PALiSUeiULliN 483

Cypricardinia 484-487

PALiBANATINA 488-491

Prorhynchus 492-494

GL088ITB8 494-502

Eltmella 502-505

Sphbnotus ? 506

Grammysia ? . . . 507

Sanouinolitk.^ 508-509

Protomya 509-510

Promacrus 510

Cytuerodon 511-512

Clinopistha 512-513

Moi>iKi,i,A 514

Mkoambonia . • 515

Ammoenia 516-518

TABULAR ARRANGEMENT OF GENERA AND SPECIES .... 519-540
ALPHABETICAL ARRANGEMENT OF GENERA AND SPECIES . . 541-552

INDEX 353-561

PLATES AND EXPLANATIONS xxxiv-lxxx and xciii-xcvi

ERRATA.

Pmge lix, tenth line fi-nm bottom, for Pktbrinba i-ead Ptkrinba.

Pa^ 888, line 1, for Ekmoxdia obliqva, n. sp., read Edmondia tumidula, n. sp.

Pa^ 407, line 2, for Spathblla typica, read Sfathkli.a typica, n. sp.

PaJ^<^ i'M, line 3, for Pabarca ph-kckdkxk, read Paharca pr^eckdrns, n. sp.

Explanation of plate li, tig«. 28-31, for Dyktactklla tki,i-inikormi8, i-ead Clixopistha tbllihifokmis.

Explanation of plate li, lign. 32, 33, for Dystaotblla subnasuta, read Clinopistha subnasuta.

Explanation of plate Ixiii, tig-. 21, for Palaomya oBU>K<tA, read Protomya oui.onoa.

Explanation of plate Ixiv, ti^fx. l.'i, 16, 23, for Edmokdia ohliqda, i-ead Edmondia tumidula.

Exjilanation of plate Ixx, fijpi. 18-20, for Ph.klahdium vknustcm, i-ead Pn.«i'ARr)n:M vbti!RTUM.

Explanation of platt* Ixxiv, for figs. 21, 22, read fi^H. 20, 21.

Explanation of plat4! xcv, tigx. .^-8, for Edmo.nuia orliqua, reiul Edmondia tumidula.

Explanation of i)late xcv, lig. 31, for Dyhtactki.la kubnasiita, read Clinopistha kubnashta.

The family naniex on platex xl, li. Hi, Ixii, Ixiii, Ixiv, Ixv, Ixvi, Ixvii, Ixviii, Ixix, Ixx, Ixxi, Ixxiii, Ixxiv, Ixxv,
were ifiven without Hiitiirieiit knowledge of the ivlationH of the species and should be cancelled by the
•ttulent.

PREFACE.

This volume includes the letter press and plates containing the descriptions
and illustrations of the Lamellibranchiata, II, and constitutes a part of
Volume V, part I, of the Palaeontology of New York.

I have already stated, in the preface to the preceding volume, that the
original intention was to publish the work as a volume of text and a volume
of plates; but the exigencies of publication made it necessary to issue the
work in two parfj^. The inconvenience attending this plan has arisen from the
necessity of adding other plates to the first part, in the Monomyaria, following
plate Ixxx; the plates from i to bcxx having previously been lithographed.
In the present volume, the few plates added to the Dimyaria have been num-
bered xciii to xcvi, following the last number in the preceding volume.

These two volumes contain the descriptions and illustrations of all the well-
known and determined species of Lamellibranchiate shells from the Upper
Helderberg, Hamilton, Portage and Chemung groups, which formations are
recognized as belonging to the Devonian System ; together with a small number
of species from the Waverly sandstone, and rocks of corresponding age, which
are generally regarded as Lower Carboniferous. A few others have been
introduced for the sake of comparison, or to show the distinguishing features
of certain genera. The comparatively few species illustrated from the Waverly
group are not to be considered as affording full means of comparison with the
fauna of the groups below.

In commencing this work, the author had conceived the plan of bringing
together illustrations of all the authentic and well-established genera of
Palaeozoic Lamellibranchiata; both in order to show the relations of those

viii PREFACE.

already published with the newer work, and especially to render the volume
more usel'ul for reference and comparison, since much confusion has existed
regarding generic relations.

The original plan, as thus proposed, cannot now be carried out, owing to the
many delays which have come from extraneous sources, and the serious inter-
ference of other duties not contemplated at the time of its inception ; and more
especially the interruption of the progress of the work for many years and its
revival under lianitations precluding the employment of the time and means
necessary for the acquisition of material required for the proper illustration
of the subject. Moreover, the types of many of the genera are widely distant,
and could only be made available by visiting the museums or collections in
which they are preserved.

The author, therefore, finds himself obliged to publish the work in its incom-
plete condition ; trusting that what has been accomplished may prove of
assistance to those who follow him, and that it may stimulate some one, with
better means for undertaking the work, to complete a monograph of the
Palaeozoic Lamellibranchiata.

The comparatively few species from the Waverly Group, given in this volume,
with the more numerous forms elsewhere published from that horizon, and from
the Carboniferous rocks above, give some idea of what might be obtained by
systematic working in the upper palaeozoic formations.

It was at one time the ambition of the author to accomplish this work ; and
it has been partly with this object in view that he has taken nmch pains to
establish the line of demarkation between the Chemung and the succeeding
Waverly Group ; which limitation was not well understood when the present
work was begun more than fifteen years since.

The remarks in the third to the seventh paragraph of the prefaces of the
preceding volume are equally applicable to the present one. With the exception
of a few plates, the work of lithography had been completed in 1876. While
the work has been under revision, the plates jidded for the farther illustration
of the genera Modiomorpha and Goniophora, are xxxv and xlii. The plates
xciii-xcvi inclusive, were necessary for the illustration of new forms, and for

PREFACE.

IX

the correction or farther elucidation of forms already lithographed in the pre-
ceding plates.

Since that period, the material in the collections has received some accessions
and a very careful examination. The genera and species have been critically
studied and extensive revision has been made in the limitations of both. A
careful examination of those species supposed to have a vertical range from the
Chemung Group to the Waverly Group or the Burlington Yellow Sandstone,
has shown that they are allied forms, but specifically distinct.

In many cases the differences are not strongly marked, but are constant and
uniform, and are such changes as might very well come with the lapse of time,
the slight change in the nature of the sediments, and the geographical relations
of the localities. The genera prevalent in the Waverly Group are identical
with tho.se of the Chemung, and in all the collections which have come under
observation, there are but four genera of Lamellibranchiata of the former group
which are not also common to the Hamilton or Chemung.

The slow and gentle gradation of generic forms is well illustrated in the
succession of strata from the Hamilton to the Waverly, and in no group so
distinctly as in the Grammysidas, as will be shown under the descriptions
of genera in the following pages.

The nature of the sediments and the characters of the fauna from the
beginning of the Hamilton Group to the clo.se of the Waverly give evidence
of gradually encroaching dry land on the eastward, or shallow sea, and off-
shore deposits. This condition culminated in the eastern area by the great
accumulation of the coarse sediments of the Catskill Group.

The conditions of preservation of the Lamellibranchiate shells rarely admit
of the study of their interior structure, and the external form and sculpturing
must be relied upon to a great extent in the determination of generic relations.
It has happened, however, in a considerable number of forms, that we have
been able to obtain illustrations of the hinge characters, leaving no doubt of
the relations of the fossil. In many cases the surface sculpturing is so distinct
and peculiar that we may group the forms together without hesitation.

In the progress of the work to its final revision, it has been found necessary

B

jt- PREFACE.

to indicate a considerahle nuinhcM- of new generic forms, which it is believed are
well founded in nature, and which will prove useful in the study of this class
of fossils. The totiU number of genera described in the volume is sixty-five,
of which twenty-six are new to science. Thirteen of these belong to the
Monomyaria and thirteen to the Dimyaria.

The total number of species described is five hundred and twenty (520), of
which two hundred and thirty-eight (238) belong to the division Monomyaria,
and two hundred and eighty-two (282) to the Dimyaria. Four hundred and
eighty-five (485) of these species belong to the Devonian System, as at present
recognized. Thirty-five are from the Waverly or Lower Carboniferous, and
five Silurian species are introduced for the piu*pose of comparison. The
former volumes of the Palaeontology contain altogether descriptions and illus-
trations of about twenty genera and one hundred species of Lamellibranchiata.

In the revision of the species, and the publication of this volume, the author
acknowledges with great satisfaction the assistance rendered by Mr. C. E.
Beecher. The original drawings of the fossils have been chiefly made by
Mr. George B. Simpson. About twelve plates are by Mr. Emerton, and four
by Mr. J. W. Hall ; the supervision of the drawing and lithography was in
charge of Mr. R. P. Whitfield. The six plates of recent additions have been
drawn by Mr. E. Emmons. The lithography has been done chiefly by Mr.
Philip Ast and Mr. Paul liiemann.

The author has been indebted for the use of specimens for illustration in
this volume to the late Dr. James Knapp, of Louisville, Kentucky ; to Prof.
J. S. Newberry and Prof. J. J. Stevenson, of New York ; to Mr. C. E. Beecher,
of Albany, and for the loan of specimens from the collections of the Cornell
University. Prof. Winchell, of Ann Arbor, has kindly loaned the types of all
his described species from the Marshall Group and Burlington sandstones, of
which farther use would have been made in comparisons with New York
forms, but for the fact that he intends soon to publish the descriptions of the
same with full illustrations of the species.

Albany, November, 1885.

INTRODUCTION.

The fossil Lamellibranchiata, of the higher groups of the New York geological
series, are often very abundant, of great variety of form, and extremely interest-
ing to the student, when once he has acquired a moderate degree of knowledge
regarding their general character and their relation to existing forms. The
study of this class of fossils in New York was begun more than forty-five
years since by Mr. T. A. Conrad, who was commissioned as Palaeontologist of
the New York Geological Survey in 1837, and our earlier knowledge of these
fossils is almost wholly due to him through his publications in the Annual
Reports of the New York Geological Survey and the Philadelphia Academy
of Natural Sciences.*

In his first Annual Report, " on the Palaeontological Department of the
Survey," published in 1838, Mr. Conrad described eleven species of Lamelli-
branchiate shells. During the following years, until 1842, this work was
continued, both in the Annual Reports of the Survey and in the Journal and
Proceedings of the Academy of Natural Sciences of Philadelphia. The total
number of species described by Mr. Conrad, from all the formations from the
Trenton limestone to the Waverly group inclusive, is about one hundred and
ten, and fifty of these have been illustrated in the publications of the Academy.
The number of species at present known and described from the same forma-

* Ml-. C»iii-a(l had ali-eaiiy, in 1835, jiublished descrijHioiis and figures of some palaeozoic forms, including
a single |>ectenoid species from the coal nieasui-es of Pennsylvania.

In 1820, Pi-ofessor Amos Eaton notices the occuiTence of Lamellibranchiata in the New York System in
his " Index to the Geology of the Northern States," etc , pp. 7t)-81. No distinct species are referred to.

In 1824, Dr. J. K. De Kay (Annals of the New York Lyceum, vol. I, p. 45, pi. 5,) published a " Note
im the Organic Remains, termed Bilobitbs, /»•<«« the Catskill Mountains," recognizing these fossils as prob-
ably the " moulds or casts of an extinct species of Cardium." These were probably the earliest notices of
any fossil bivalve shells from the palteozoic rocks of New York.

xu INTRODUCTION.

tions, within the same area, is more than six hundred (600), of which about
five hundred (500) are from the rocks above the Oriskany sandstone.

In 1842, Mr. Connvd having resigned his position as PaliBontologist of the
Survey, without making any final Report, the Geologists were left to their own
resources in providing illustrations of the characteristic fossils of the forma-
tions within their several districts. The final Reports of the State Geologists,
therefore, will be found to contain illustrations of a considerable number of
the Lamelli branch lata.

During the interval named, and for many years subsequently, the writer, both
personally and by the aid of his assistants, made extensive collections of this
class of fossils in the State of New York, and to a less extent in other States.

At a still later period, from 1856 to 1870, extensive collections were made
preparatory for the Palaeontology of the State, through the means afforded by
appropriations of money by the Legislature.

In making preliminary studies of these fossils, the author found that the
types of Mr. Conrad's species were to a great .extent inaccessible, or were dis-
tributed through the collections of several institutions, and of private individuals.
In order to secure accuracy in the identification of the described forms, he
availed himself of the assistance of Mr. Connid for the study and comparison
of all the species. On three several occasions Mr. Conrad spent a considerable
time in Albany, in the study of the collections here accumulated ; and in the
identification and determination of species, labeling one or more specimens of
tho.se which he recognized as typical forms of the species he had previously
described. In this manner, and by later studies and comparisons, it is believed
that proper identification has been made with nearly all the described forms,
and due credit has been given in this wotk.

From the time Mr. Conrad ceased his publications upon the Lamellibriinchiata,
numerous writers have published descriptions and illustrations of American
species of this class of fossils, until at the present time the entire number of
palaeozoic species recorded is more than twelve hundred and fifty.

The principal authors, who have contributed to our knowledge of the subject,
are given below in alphabetical order. To cite the date and title of the pub-

INTRODUCTION.

xiu

lications of each one, would occupy more space than the author has at his
command in this introduction ; and moreover, few of these writers have pub-
lished species from the State of New York.

The following authors have published descriptions of species of American
Palaeozoic Lamellibranchiata :

Billings.

Hinde.

Salter.

Castelnau.

James.

Shumard.

Clarke.

Lea.

Stevens.

Conrad.

Marcou.

Swallow.

Cox.

Marcy.

Ulrich.

Dawson.

McChesney.

de Verneuil,

Dyer.

Meek.

Vanuxem.

Emmons.

Miller.

Walcott.

Gabb.

Morton.

White.

Geinitz.

Newberry.

Whitfield.

Hall.

Nicholson.

Williams.

Hartt.

Owen.

Winchell.

Haughton.

Pitt.

Worthen.

Hayden.

Safford.

During a long interval, after the close of Mr. Conrad's labors, very little was
done in New York beyond the accumulation and study of collections, and the
determination of specific forms for the illustration of the New York Devonian
Lamellibranchiata.

In 1869, the writer published " Preliminary Notice No. 2 of the Fossil
Lamellibranchiate Shells of the Upper Helderberg, Hamilton, Portage and
Chemung Groups," etc., to the number of eighty pages, which were issued in
December of that year, and one hundred copies in this form were distributed.
In January following the printing was resumed, and sixteen additional pages
were printed. The pamphlet thus augmented, together with a supplementary
page, stating the fact that the descriptions of other species were then in type,

XIY

INTRODUCTION.

was distributed to the public* Since that time, the author has had no
opportunity of completing the printing according to the original plan of the
work.

This Preliminary Notice was originally prepared for incorporation in the
23d Report of the State Museum of Natural History, but it was published in
advance, as a separate pamphlet, and has never been incorporated in any Report
of the State Museum. The species there described have been included in the
present and preceding volume with proper reference to the original publication.

The Preliminary Notice of the Lamellibranchiata No. 1, including the
Monomyaria, was communicated with the 34th Report of the State Museum
of Natural History, but was only published in the 35th Report, issued in 1884.

This paper, with plates giving generic illustrations, has been published in a
separate form, making a pamphlet of about 200 pages with five lithographed
plates of generic illustrations.

There are very few forms of Lamellibranchiata known in the primordial zone,
nor until we reach the Chazy and Trenton periods are the fossils of this class
found in any considerable number. In volume I of the Paleontology of New
York, there are but two species described from rocks below the Trenton lime-
stone. Twenty-six species were described from that formation, and in the
Utica slate and Hudson-river group, fourteen species were recognized. Later
collections have largely increased the number, and it is not improbable that a
study of the material since accumulated from the same localities will show
double the number then known. So far as observed, the individuals of species
in the Trenton limestone are not abundant, a few forms only having been
collected in considerable numbers.

The species are more common in the limestones where there is consider-
able argillaceous matter, either intimately mingled with the calcareous mass,
or when the calcareous layers are separated by argillaceous seams ; and the
fossils are usually casts of the interior, the shells being rarely preserved.

In the Hudson-river group, within New York, the species of this class, while

•The printiriff w«h disoontinued at this point, page 96, owing to the burning of the printing office with
nil the matter in type ex<^ept the atereotyped plat«a.

INTRODUCTION.

xy

fewer than in the Trenton limestone, are more numerous as individuals, and
make a much more conspicuous feature of the formation than they do in the
Trenton limestone.

In the Trenton limestone, at Ottawa, in Ontario, the shells of the Lamelli-
branchiata are replaced by silica. This condition of the fossil enabled Mr.
Billings to remove the calcareous matter by acid and determine the hinge-
structure of several forms which were before unknown. In the Canadian
Reports, this author has recognized a single species from the Calciferous sand-
stone and four species from the Chazy limestone. From the Lower Silurian
(as then understood), he has published thirty-two new species, or a number
nearly equal to all which had before been known to the public from the same
rocks. He has likewise recognized, in the Canadian rocks, a large proportion of
the species known in the New York formations of the same age.

The Trenton and lower limestones in their westerly extension are not more
prolific in species of Lamellibranchiata than the same rocks to the eastward;
but many new forms appear in the western localities. In this respect, how-
ever, the Hudson-river group forms a striking contrast with the same forma-
tion in the east. With the increase of calcareous matter in its composition, as
traced in a westerly and north-westerly direction, the fauna becomes more
abundant, and finally, in its greatest development, is more prolific in some
classes of invertebrate fossils than any other of the palaeozoic formations.
With this general development the Lamellibranchiata keep pace, and the
number of species described from this group in Ohio, Kentucky and Tennessee,
and other western localities, far exceeds all that have been described from all
the Eastern States. The entire number of species from this group, enumerated
in Miller's Catalogue, is eighty-seven.

In the succeeding sedimentary formations of the Medina sandstone and Clin-
ton groups of New York there are few species of this class of fossils ; and the
number in the calcareous measures constituting the Niagara group is scarcely
greater. In the Palaeontology of New York, vol. II, twenty-seven species are
described, of which two are from the Medina sandstone and nine from the
Clinton group, leaving the remainder (including those from the Coralline lime-

XVI

INTRODUCTION.

stone and from the Guelph limestone), sixteen species, which are of Niagara
age.

In the western extension of the Niagara group, the magnesian calcareous beds
of the north-west have furnished a considerable addition to the number of species
known in eastern localities ; while the more southerly exposures of the shaly
calcareous beds of the group in Indiana have furnished others which are quite
unlike either the New York, or the Wisconsin and Iowa species. The Niagara
of Tennessee has afforded little information in regard to the Lamellibranchiate
fauna of that period.

From the calcareous and shaly measures of the Lower Helderberg group, in
New York, there were described, in the PALiEONTOLOOY of New York, vol. Ill,
thirty-four species, and five species peculiar to the Oriskany sandstone. The
exposures of the same formation in the south-west have added little to our
knowledge of this class of fossils : though it is probable that many more species
will be found on careful investigation.

Rocks of the same age as the Lower Helderberg and Oriskany in eastern
Canada have afforded a considerable number of additional species, which have
been described in the Canadian Geological Reports.

Succeeding the Oriskany sandstone, which is usually considered as the line
of demarkation between the Silurian and Devonian systems, we find the Upper
Helderberg group with a moderately developed Lamellibranchiate fauna.

In the middle Devonian, including the Hamilton, Portage and Chemung
groups, this fauna for the first time in the geological history of the palaeozoic
formations in the State of New York, forms a conspicuous feature, both in
number of species and abundance of individuals.

In the eastern and central counties of the State, the fossils of this class are
distributed through more than one thousand feet in thickness in the sediment-
ary strata of the Hamilton group. These forms gradually diminish in number
and abundance as the formation becomes more calcareous in its western exten-
sion, and the arenaceous sedimentary portions grcodually become attenuated or
altogether disappear, giving place to fine calcareous shales, which are not favor-
able to the development of this class of organisms.

INTRODUCTION. xvii

The continuance of this fauna is almost entirely interrupted by the coming
in of the Genesee slate and the Portage shales and sandstones in central and
western New York, and is abruptly terminated in the eastern part of the State
by the sedimentary accumulation of the Oneonta sandstone.

The Portage group, in some of its typical localities, carries a few forms of
Lamellibranchiate shells, some of which, so far as we now know, have no
generic relations with the prevailing forms above or below this horizon.

The genus Panenka and Lunulicardium, as well as the cosmopolitan form
Glyptocardia, also occur in the Portage group. Thus far the pectenoid or
aviculoid forms are not known in the rocks of this age, but our knowledge is not
yet sufficient to speak positively of its entire fauna. Moreover, the western
extension of this group has not been satisfactorily determined, and we are
unable to present any facts regarding the distribution of species of that age
beyond the State of New York.

Following the final deposition of the two latter formations, the Lamelli-
branchiate fauna reassumes its prominence under a somewhat modified aspect. A
few of the forms which were predominant in the Hamilton group have become
subdued in force, while others are augmented. Among the Monomyaria, there
is a notable increase in the number of pectenoid and aviculoid forms, espe-
cially of Pterinea and Actinopteria.

In the formations below the Chemung, the genus Leptodesma is represented by
two species, while the total number described is fifty-seven. Leiopteria, on the
other hand, shows its greatest development in the Hamilton group. Pteronites
proper is unknown below the Chemung, and the genus Ptychopteria, with its
twenty-two species, is also unknown below that horizon.

Among the pectenoid forms there is a larger number of species of Pterino-
pecten below the Chemung, while Crenipecten, with its eight species in the
Chemung group, is also unknown to us in any lower formation.

The genus Glyptodesma, so abundant and varied in form in a single species
in the Hamilton group, is at present unknown in any higher formation.

Pterinea flabella, beginning its existence at the horizon of the Corniferous

XVUl

INTRODUCTION.

imestone, becomes very abundant and varied in form in the Hamilton group,
reappearing in considerable numbers, and acquiring very extravagant forms
in the Chemung group.

The genus Grammysia, so abundant and characteristic in the Hamilton group,
is far less conspicuous in the Chemung group, gradually losing its characteristic
features to such a degree that it becomes a question with regard to some forms
whether they shall be referred to Grammysia or AUorisma.

At the base of the Upper Helderberg group, the Schoharie grit carries a few
species of this class of fossils which are peculiar to that rock. A considerable
number of species make their appearance for the first time in the Corniferous
limestone ; and some of these are continued into the Hamilton group. A few
species in this rock are remarkable for their persistence. The Aviculopeden
princeps of Conrad is known in this horizon in New York, Ontario, Ohio and
Indiana.

The Hamilton group in its western extension becomes a calcareous forma-
tion, and is represented in Wisconsin, at the Falls of the Ohio, and at other
places, by a magnesian limestone, with more or less shaly matter interspersed
throughout the mass, or intercalated in thin laminae. At the Falls of the Ohio,
the Hydraulic beds, which are equivalent or representative of the Hamilton
group, contain at least twenty species of Lamellibranchiata, ten of which are
likewise common to the Hamilton group in New York.

On the Mississippi river, the Hamilton group is represented by a limestone
carrying many of the characteristic fossils (especially Brachiopoda) of the
formation in its eastern development.

The Chemung group in its lower members is more restricted in its geograph-
ical distribution than the Hamilton group. Its central and upper members,
have a wider expansion than the lower beds, and everywhere carry a peculiar
and characteristic Lamellibranchiate fauna. Some of the genera common to
the Hamilton group disappear almost entirely, while many new forms come in
above the Portage ; and several genera first appearing in lower horizons, here
reach their greatest development in number of species.

In the lower members of the group, as at Ithaca, and adjacent localities, a

INTRODUCTION. xix

notable number of Hamilton species recur, but in nearly all cases they appear
in a pauperized condition, as if the sediments were unfavorable to their growth
and development. The fauna of the group, as developed at Ithaca and vicinity,
is comparatively limited in geographical extent, being interrupted on the east by
the influx of coarser sediments, and, so far as observed, the strata soon thin
out on the west, or are merged in beds above and below, losing any distinctive
faunal character which may mark the formation in its central development.

A considerable number of species occur in this part of the group, which do
not pass above that horizon, and it was from this fact, and also from the recur-
rence of lower forms in the same strata, that Mr. Vanuxem proposed to
designate the formation as the Ithaca group. There are difficulties attending
such a separation and distinction, since there is yet no well-recognized limi-
tation between the fossiliferous beds of Ithaca and the Portage below, and, on
the other hand, it has not been shown that this formation is distinctly separated
from the typical Chemung lying above, and which has a great development in
Chemung and adjacent counties.

The Lamellibranchs most characteristic of the central part of the group,
are several species of Leptodesma and Pterinea, which are abundant in the
valley of the Chemung river and in numerous localities in the same
horizon.

The upper members of the Chemung series are in general well marked and
characterized by the abundant presence of Spirifera disjuncta=S. Verneuili, which
is common to the various beds of shale, flags, slates, sandstones, conglomerates
and calcareous bands found in the upper part of this group ; but the Lamelli-
branchiate fauna has no such general or uniform distribution.

These fossils occur in small assemblages of species and genera, and are very
circumscribed in extent, as if their duration or continuance was limited to each
change in the sediments, which were apparently deposited in shallow pools or
small areas over the sea bottom. This at least is the present aspect of the
question, and we can only await more extended and critical examinations of
the exposures of these strata before propounding any other solution of the
problem.

zz

INTRODUCTION.

In some localities we have the most positive evidence that the sediments
have been deposited in circumscribed areas, as in the case of the Panama con-
glomerate and the Salamanca sandstones, and in these examples we have a
peculiar and restricted fauna.

In its far western extension the Chemung group has become a calcareous
formation, bearing many of the characteristic forms of Brachiopoda and but few
of the Lamellibranchiata so characteristic of the group in the east.

The Waverly sandstone and its equivalent or representative formations in
the west, have not yet been studied with that degree of care and comparison,
over wide areas, which are sufficient to warrant generalizations regarding the
distribution of the Lamellibranchiate fauna. The species described from
widely separated localities are a sufficient evidence that the conditions for the
development of such a fauna have existed over a wider extent than in previous
periods of geological history.

In the process of sedimentation and the imbedding of the shells of this class,
the valves have, for the most part, been separated ; and the inner surface adher-
ing to the rock, it becomes very difficult to ascertain the hinge structure, a
character which should be the basis of generic distinction in fossils of this
class.

In far the larger proportion of the specimens of the Lamellibranchiata
obtained from the rocks of New York, the shells have been macerated or dis-
solved to such a degree that we have barely a film remaining which preserves
the external markings, or, in some species, the characters of the interior are
visible without having the exterior markings of the shell entirely destroyed.
Many of the shells are extremely thin, but some of the stronger forms, in cer-
tain conditions of the matrix, have the shell well preserved. In these forms
we have often well-marked casts of the interior, and rarely we may obtain
the exterior shell in such condition as to show its entire characters.

In the study of the species of this cl.ass of shells it is not always possible to
determine the changes in form and expression, which may be due to physical
influences, and in some degree also to the chemical effects operating upon the
enclosing matrix.

s

INTRODUCTION. xxi

In the gradual dessication and hardening of the soft muds in which the shell
was originally imbedded, extreme changes in form are sometimes wrought, as
is more distinctly shown where two valves held in connection by the liga-
ment, one has been imbedded horizontally, retaining essentially its original
form, while the other, imbedded vertically, or with its basal margin downward,
is narrowed by the vertical pressure to a degree which leaves it quite unlike in
form to the corresponding attached valve, as has been shown in a few illustra-
tions in this volume. Where such influences are exerted upon single discon-
nected valves we have no means of knowing the degree of distortion produced
except by comparison with other valves recognized as of the same species.
Shells Avhich in their original condition may have been convex or even gib-
bous, have become flattened by the pressure, especially in the thinly laminated
beds ; and unless found under more favorable conditions, their true proportions
may not become known. A slightly oblique pressure may change the position of
the beaks relative to the anterior or posterior extremities 'of the shell without
distorting the general form. The general outline of the shell may also sufier
from very slight movements of the solidifying matrix.

The surface markings may become more or less obliterated and sometimes
modified by a covering of very fine sand which adheres to the shell. The
sharpness of the surface striae is frequently subdued or nearly obliterated by
maceration, or from the presence of iron pyrites, where decomposition leaves
the resulting acid to attack the prominent portions of the surface and thus
modify or destroy the exterior characters.

Through the influence of such modifying conditions it may often happen
that characters which are regarded as of importance in the living shell may be
obscured or obliterated during the process of fossilization.

Considering the effect of all these influences, it often requires great care to
determine what are really specific distinctions, and what modifications may be
due to extraneous causes. With a small number of individuals, derived from
one or two localities, it may not always be possible to make the proper discrim-
ination. The true determination of the limits of species in this class of fossils

xxii INTRODUCTION.

is always attended with difficulty from the causes named, and the influence of
individual judgment should always be considered.

In order, therefore, to avoid erroneous conclusions regarding the real charac-
teristics of these fossil shells, it becomes necessary to acquire extensive collec-
tions, not only from one or a few localities, and a single condition of the rock,
but from numerous and widely separated localities, .and from the rock in all its
phases of composition and conditions of deposition.

SYNOPSIS OF THE GENERA INCLUDED IN THIS VOLUME.

Modiomorpha, Hall (Preliminary Notice Lamellibranchiata, 2, p. 72. 1870).
[Type, Pterinea concentrica, Conrad.]

Shell equivalve, very inequilateral, sub-ovate in outline, largest posteriorly.
Anterior end rounded, forming a projecting lobe of greater or less extent
beyond the beak. The valves are crossed obliquely by a more or less distinctly
defined cincture passing from the beak to the base, and constricting the basal
margin. Beaks small, compressed.

Surface of the shell marked by rugose or undulating concentric striae.

Hinge furnished with a strong wedge-form tooth in the left valve and
a corresponding cavity in the right. No lateral teeth have been observed.
Ligament external, attached to the thickened margin of the shell, which is
often longitudinally grooved for its reception. Anterior muscular impression
situated within the anterior extension of the shell. Posterior impression large
and superficial, situated on the posterior slope. Pallial line simple.

Examples : Modiomorpha concentrica, pi. xxxvi, figs. 1-18.
Modiomorpha mytiloides, pi. xxxviii, figs. 1-16. .

Goniophora, Phillips (Memoirs Geol. Surv. Gt. Britain, vol. ii, pt. 1, p. 264.
1848). [Type, Goniophora cymbiformis, Sowerby, sp.]

Shell equivalve, very inequilateral, rhomboidal or trapezoidal in outline,
obliquely truncate behind and rounded in front. Cardinal line usually straight
and not oblique. Beaks small, closely incurved, situated within or about the
anterior third of the shell. Umbo prominent. Umbonal slope continued as a

xxiv SYNOPSIS OF GENERA.

strong angiilivr ridge to the .'post-inferior margin. The valves are crossed
obliquely, sometimes vertically, by a broad undefined sinus extending from
anterior to the beaks to the basal margin, which is usually slightly constricted
at this point.

Surface marked by more or less regular concentric striae, which may be either
simple throughout or fasciculate on the anterior portion of the shell. Some
species are marked by strong radiating striae upon that portion of the valves
iKJtween the umbonal ridge and the sinus.

Hinge furnished with a strong oblique fold or tooth in the left valve, situated
just beneath the beak, and a corresponding depression in the right valve. No
lateral teeth have been observed. Ligament external, strong ; its attachment
to the shell is marked by one or more defined grooves. Muscular impressions,
two; the anterior one deep and strongly marked, situated a little anterior to the
beak and just within the anterior margin. Pallial line simple, continuing nearly
parallel to the basal margin until it crosses the umbonal ridge, and recurving
to the posterior muscular impression which is large and shallow, and situated
on the posterior cardinal slope sometimes near the middle of the length of the
shell.

This genus was proposed by Phillips * in 1848 as a generic designation for
the original Cypricardia cymbiformis of Sowerby, but without generic definition
or illustration of internal characters, and so far as known, the genus has never
been heretofore described.

The shells here referred to Goniophora have similar internal characters with
Modiomorpha, the external form and especially the strong umbonal ridge being
the principal distinguishing features. This generic form occurs in the Trenton
limestone, Niagara group, Schoharie grit, Hamilton and Chemung groups.

Examples : Gonioph(,ra perangulata, pi. xxxiv, figs. 1-6.
Goniophora Glaucus, pi. xliv, figs. 10-17.

• M«Miinin< (lool. Snrv. Gt. Britain, vol. 2, pt. 1, ]>. 2(54. •* If, as I suppose, Cypricardia cymhifor-iiiix be
dintinct, generically, and include species of tlie mountain limestone, the name Qoniophora seems suitable.
It ia, however, doubtless, a mytiloid shell."

SYNOPSIS OF GENERA. xxv

Microdot!, Conrad (Journal of the Academy of Natural Sciences, Philadelphia,
vol. viii, p. 247. 1842). [Type, Microdon bellistriata, Conrad.]

Shell equivalve, inequilateral, transversely sub-elliptical or sub-quadrate in
outline. Cardinal line straight or slightly arcuate. Anterior end narrowed
and rounded. Posterior extremity broad and truncate. Beaks small, pointed,
appressed, situated nearer the anterior end. Umbonal ridge more or less
defined, extending from the beaks to the post-inferior angle.

Surface marked by more or less rugose and regular concentric striae.

Hinge characterized by a triangular tooth in each valve, that of the left
valve short and situated beneath the beak, with a more elongate pit or groove
l)ehind it for the reception of the tooth of the right valve. The right valve
ha.s also a triangular pit beneath the beak for the reception of the short tooth
in the left valve, and a longer triangular fold behind, which is sometimes
double. No lateral teeth have been observed, unless the long oblique fold of the
right valve be regarded as a lateral tooth. Ligament external, extending almost
or quite the entire length of the cardinal line. Anterior muscular impression
moderately large, sub-circular or short reniform ; posterior scar superficial.
Pallial line simple.

Owing to the fact that the name Microdon had previously been established by
Agiissiz for a genus of fishes, the name Eodon was proposed by Hall and Micro-
dondla by (Ehlert. The genus Cypricardella (Trans. Albany Inst., vol. iv.
1856) has been shown to be identical with Microdon* If the name Microdon
in to be suppressed, the name Cypricardella will have precedence. Microdon is
retained for the present, using the genus Cypricardella parenthetically.

Examples : Microdon {Cypricardella) bellisiriatus, pi. Ixxiii, figs. 7-22 ; pi.
Ixxiv, figs. 5-10.
Microdon {Cypricardella) tenuistriatus, pi. Ixxiii, figs. 23-30; pi.
Lxxiv, tigs. 20, 21.

• R. P. "Whitfield. Bull. Am. Mus. Nat. Hist., vol. i, No. 3, p. 63. 1882.

xxvi SYNOPSIS OF GENERA,

Nucula, Lamarck (Hist. An. Sans. Vert. 1799).

Shell small, equivalve, inequilateral, trigonal or transversely elliptical or
sub-circular. Anterior or posterior extremity sometimes produced, usually
rounded. Beaks anterior or posterior to the middle of the length, often sub-
central. Cardinal line arcuate. Escutcheon marked.

Surface marked by concentric striae, which, in some species, are regular
and rugose.

Hinge furnished with a triangular, spoon-shaped cartilage-pit beneath the
beaks, with a series of small transverse teeth on each side. There are two
principal muscular impressions in each valve, with usually a smaller retractor
scar adjacent, and also the cavity of the beaks often shows several pits for
the attachment of umbonal muscles. Pallial line simple.

Most of the species described in this volume have the beaks anterior to the
middle. One species, N. lamellata, shows the beaks posterior to the centre, but
in a few specimens of this species it is sub-central.

Examples : Nucula Randalli, pi. xlv, figs. 6-10, 16, 23, 26, 27 ; pi. xciii, figs. 1-3.
Nucula varicoaa, pi. xlvi, figs. 12-23.

Nuculites, Conrad (Geol. Surv. N. Y., Ann. Rep., p. 49. 1841).
[Types, Nuculites oblongatus, Conrad, and Nuculites cuneiformis, Connid.]

Shell equivalve, inequilateral, transverse. Anterior end rounded. Posterior
end sometimes obliquely truncate and pointed. Beaks anterior. Cardinal line
arcuate. Post-umbonal slope rounded or angular.

Surface marked only by concentric striae in all the known species.

Hinge furnished with a row of transverse narrow teeth, beginning at the
anterior muscular scar and extending without interruption posteriorly as far
as the posterior scars. Ligament external, contained in a narrow groove along
the margin of the hinge. Anterior muscular scar deeply impressed, separated
from the cavity of the shell by a vertical or slightly oblique clavicle, or parti-
tion, extending about two-thirds the distance from the beak toward the base.
Posterior scar elongate, situated just below the termination of the hinge

SYNOPSIS OF GENERA.

xxvn

crenulations. Just anterior to the posterior adductor are one or two small
retractor impressions. The cavity of the umbo also usually shows three or
four impressions of umbonal muscles. Pallial line simple.

This genus differs very distinctly from Nucula in the anterior clavicle and
absence of cartilage-pit.

Examples : Nuculites oblongatus, pi. xlvii, figs. 1-12.
Nuculites triqueter, pi. xlvii, figs. 17-28.

Leda, Schumticher (Essai, p. 172, pi. xix, fig. 4. 1817).

[Type, Area rostrata, Chemn.]

Shell equivalve, inequilateral, transverse, often lunate, produced behind and
rostrate. Anterior end rounded. Beaks often turned toward the posterior.
Post-umbonal slope defined, extending from the beak to the posterior extremity,
and often forming a nasute extension.

Surface marked by more or less regular concentric striae.

Hinge furnished with a line of minute teeth which is interrupted at the beak
by the triangular cartilage-pit. Muscular impressions two, small. Pallial line
simple or with a very slight sinus.

Examples: Leda brevirostris, pi. xlvii, figs. 38-41.
Leda rostellata, pi. xlvii, figs. 42-47.
Leda pandoriformis, pi. xlvii, figs. 49, 58.

Palaeoneilo, Hall (Prelim. Notice Lamellibranchiata, 2, p. 6. 1870).
[Type, Nuculites constricta, Conrad.]

Nuculiform shells, transversely ovate or sub-elliptical, the posterior end
extended, often sub-rostrate, with a more or less defined sulcus along the
umbonal slope. Cardinal line arcuate.

Surface marked by striae of growth, which are often lamellose and elevated
into concentric ribs.

Hinge furnished with a row of regular small transverse teeth, which is some-
what interrupted beneath the beak by a change in the direction of the teeth,

xxviii SYNOPSIS OF GENERA.

or by several oblique teeth* Ligament external, contained in a shallow and
narrow groove along the cardinal border Muscular scars not strongly impres-
sed, situated below the extremities of the hinge-line. Pallial line simple.

This genus differs materially from Nucula, Leda and Yoldia, in the absence of
a cartilage-pit beneath the beaks ; in having an external ligament and a sulcus
on the post-umbonal slope. It differs from Nuculites in form, and in the absence
of a clavicular ridge on the anterior end. In general form and internal char-
acters this genus very closely resembles Tellinomya, and it is probable that
further study will prove that the two are congeneric.

Examples : Palaoneilo constrida, pi. xlviii, figs. 1-16.

Palaoneilo fecunda, pi. xlix, figs. 13, 15-24.
PaUumeilo attenuala, pi. 1, figs, 34-39.

Macrodon, Lycett (Murch. Geol. Chelt.).

Shell equivalve, inequilateral, transverse, sub-elliptical, or sub-ovate in out-
line. Anterior end angular at the cardinal line, rounded below. Posterior
end rounded or obliquely sub-truncate. Beaks anterior to the middle. Cardinal
line long and straight.

Surface marked by concentric striae which are often regularly laminose, and
in some species by fine radiating striae.

Hinge furni.shed with several (sometimes eight) small diverging teeth beneath
the beak and by from two to four lateral teeth situated near the posterior ex-
tremity of the cardinal line. Ligament external. Muscular impressions not
strongly marked. Pallial line simple.

Examples : Macrodon Hamiltonia, pi. li, figs. 1-7, 9, 10.
Macrodon Chemungemis, pi. li, figs. 11-16,

♦ The hing'e chai-acters of this gfenus and the resemblance to the genus Neilo were firat indicated to me
by Mr. R. V. Whitfield.

SYNOPSIS OF GENERA. xxix

Ptychodesma, Hall and Whitfield (Twenty-fourth Ann. Rep. N. Y. State
Museum Nat. Hist., p. 192. 1872).

[Type, Ptychodesma Knappianum, Hall and Whitfield.]

Shell equivalve, inequilateral, obliquely sub-ovate. Anterior end short, more
or less defined by a shallow cincture extending from the beak to the base.
Posterior extremity broadly rounded. Cardinal line short, nearly straight,
often arching. Umbonal slope rounded.

Surface marked by concentric striae of growth.

Hinge with two or more cardinal teeth and a wide and deeply excavated
ligamental area, the sides of which are sharply grooved in parallel lines. The
grooves and ridges are slightly arched beneath the apex of the valves where
they take their origin. Anterior muscular impression strong.

Example : Ptychodesma Knappianum, pi. li, figs. 22-27.

Nyassa, Hall (Preliminary Notice Lamellibranchiata, 2, p. 27. 1870).

[Type, Nyassa arguta, Hall.]

Shell equivalve, inequilateral, transversely elongate or sub-elliptical. Beaks
small, usually appressed, situated near the anterior end. Cardinal line long,
arcuate. The middle of the shell is often marked by an oblique cincture,
which produces a constriction in the margin. Umbonal ridge more or less
defined, extending to the post-inferior extremity.

Surface marked by concentric lines of growth, and in some species by obscure
radii.

The anterior end of the hinge-plate is furnished with a number of irregular
teeth or plications in the young stages, which become more or less thickened
and coalescent with age. Posteriorly, the hinge is marked by from one to four
elongate lateral teeth. Ligament external, inconspicuous. Anterior muscular
scar strong and deep. Posterior scar larger and fiiintly marked. Pallial line
simple.

Examples : Nyassa arguta, pi. liii, figs. 7-20.

Nyassa subalata, pi. liii, figs. 21-26.

XXX SYNOPSIS OF GENERA.

Grammysia, DeVerneuil(Bull. Soc. Geol. France, 2d 8er.,vol. iv,p.696. 1847).
[Type, Grammysia Hamiltonensis, De Verneuil, 1847 = Pterinea bisulcata,
Conrad. 1838.]

Shell equivalve (with the exception of the alternation of the cincture
and fold in the two valves, which produces a slight inequality), inequilateral,
transversely elliptical or sub-ovate. Margin.s closed. Beaks prominent and
incurved, situated anterior to the middle. Cardinal line straight or somewhat
arcuate. Escutcheon and lunule well defined. Valves, in the typical forms,
traversed from the beak to the base by an oblique cincture and adjacent fold,
which may be duplicate, and are alternating in the two valves, sometimes pro-
ducing a constriction and short extension of the ventral margin. Some species
show the cincture developed in the upper part becoming obsolete before reach-
ing the margin. Many forms show a broad cincture without an adjacent fold ;
and in some species the cincture is indicated by a line of slight interruptions
or irregularities in the concentric undulations ; other species have the surface
continuous, without cincture or fold.

Surface marked by concentric striae of growth, and often by strong concen-
tric undulations. Many species also show fine pustulose radiating striae.

Hinge-plate short and strong, with one or two thickened folds beneath the
beak of some species. Ligament external, closely resembling that of Unio.
Anterior and posterior muscular impressions faintly marked, the latter much the
larger. Pallial line simple, often broken into pits and furrows.

The above description is emended to include cingulate and smooth forms.
It has been found that the cincture is a very variable character even in the
same species, and that no generic line can be drawn between species having a
well-developed cincture and those in which this feature is obsolete.

This genus as properly limited will be found to include many species hereto-
fore referred to Allorisma,- Sanguinolites, Orthonota, Chcenomya, etc.

Dr. L. G. de Koninck has lately (Faune Calcaire Carb de Belgique, pt. v, p.
4. 1885)* referred most of the species heretofore regarded as Grammysia to the

♦The letter press of the deacriptions of species of this volume was all in type before Dr. de Koniuck s
publication was received, and hence no references or coiupai-isons of species could be made.

SYNOPSIS OF GENERA. xxxi

genus Chanomya, overlooking the fact that the type of Grammysia is a New-
York species, and has been made the basis of comparison of all the species
published in the Preliminary Notice of the Lamellibranchiata and in the present
volume ; Grammjsia has also a priority of seventeen years over Chanomya.
A reference to the type of Ch&nomya (C. Leavenworthemis) will also show the
marked differences between that form and those here referred to the genus
Grammysia. Chanomya has the valves gaping behind as in the recent genus
Mya, the pallial line is sinuate and the beaks are small and appressed.

Mr. J. W. Salter (Mem. Geol. Surv. Gt. Britain, pp. 359-361, 1848) considers
Grammysia as a sub-genus of Orthonota and that Allorisma is a synonym of the
latter genus. In accordance with this, he describes the species O. cingulata,
Hisinger sp., O. triangulata, Salter, and 0. extrasulcata, Salter, and notes their
relationship with the species of Grammysia, as defined by De Verneuil.

The genus Grammysia seems to be well-founded in nature, and is quite
distinct from Orthonota, although with our present knowledge it is difficult to
clearly separate Grammysia from Allorisma, as now recognized, on account of
the numerous intermediate species which seem to unite the two extremes of
variation.

Examples : {Section a. cingulata) Grammysia bisulcata, pi. liv, figs. 1-16 ; pi.
ivi, fig. 1 ; pi. xciii, fig. 25.
{Section b. obsoleta) Grammysia obsoleta, pi. lix, figs. 21-27.
{Section c. undulata) Grammysia alveata, pi. Ivii, figs. 1, 2; pi. Ix,

figs. 1-11.
{Section d. elongata) Grammysia communis, pi. Ixi, figs. 24-28; pi.
xciii, fig. 21.

For convenience of reference and description, the species described in this
volume have been arranged in the four natural groups as above indicated.
The first group represents the typical form of Grammysia, while the last group
includes species which have sometimes been referred to Allorisma, and may per-
haps with propriety be included in that genus.

The generic description of Allorisma (King, 1844), as redefined (King, Perm.
Foss., p. 196, 1850), is here given : " Equivalved : inequilateral, the posterior
side being the longest : in general slightly gaping. Valves granulated on the

xxxii SYNOPSIS OF GENERA.

surface ; more or less undulated or ribbed parallel to the free margins ; and
articulating with each other by means (only) of an external cartilage. Anterior
adductor muscular impressions, in general, near the antero-ventral margin. Sinus
deep in some species, and shallow in others."

" Type, Hiatella sulcata, Fleming."

In the volume of Plates and Explanations (1883), the name Sphenomya was
proposed as a sub-genus of Grammysia, differing from that genus in its ovate-
cuneate, oblique form, and absence of ligamental groove. It closely resembles
the typical form of Cuneamya, but also differs in the absence of the ligamental
groove. The name is at present confined to a single species.

Example: Grammysia (Sphenomya) cuneata, pi. Ixii, figs. 1-9 ; xciii, fig. 19.

Euthydesma, n. g. [Type, Astarte subtextilis, Hall.]

Shell equivalve (?), inequilateral, broadly sub-ovate with a sub-alate cardinal
expansion. Cardinal line rigidly straight. Anterior end short. Beaks sub-
anterior.

Surface marked by concentric striae of growth, and in the species described,
by slender radiating striae.

Hinge-line straight, and marked by a distinct, continuous ligamental groove.

But one species of this genus is at present known and its characters do not
seem to ally it with any described form.

Example: Euthydesma subtextile, pi. Ixiii, figs. 11-16; xciii, figs. 28, 29.

Edmondia, de Koninck (Anim. Foss. Carb. Belgique, p. 66). 1844.

Shell equivalve, oval or sub-circular. Beaks varying from sub-central to
nearly anterior.

Surface marked by concentric striae, and sometimes by obscure radii or fine
radiating striae.

Hinge narrow, without teeth. Ligament external, contained in a groove
along the cardinal line. Muscular impressions not strongly impressed. Pallial
line simple.

Examples: Edmondia Philipi, pi. Ixiv, figs. 9, 11-14, 17, 29; pi. xcv, figs. 1-4.
Edmondia subovata, pi. Ixiv, figs. 18-20, 26-28 ; pl. xcv, figs. 9-12,

SYNOPSIS OF GENERA. xxxiii

Sphenotus, n. g. [Typical species, Sanguinolites arcaeformis, Hall, and

Cypricardia contracta, Hall.]

Shell equivalve, very inequilateral, elongate sub-trapezoidal or cylindrical in
outline. Anterior end short. Posterior end usually obliquely truncate. Beaks
sub-anterior. Cardinal line long and nearly straight. Umbonal ridge defined,
extending from the beak to the post-inferior extremity. Post-cardinal slope
marked in all the characteristic species by a median ridge. Valves crossed
from the beak to the base by a more or less defined, broad cincture, which often
produces a constriction in the ventral margin.

Surface marked by concentric striae of growth, and rarely by fine radiating
lines. In a single species {S. solenoides) the surface is further ornamented by
fine, irregular, elevated vascular lines on the posterior half of the shell, espe-
cially above the umbonal ridge.

Hinge narrow, with two short, narrow cardinal teeth beneath the beak of the
right valve, and with one or two extremely slender lateral teeth. Ligament
external, contained in a slender groove along the cardinal line. Anterior mus-
cular scar strongly marked, situated close to the anterior margin. Posterior
scar shallow. Pallial line simple.

The species united under the preceding generic description have been refer-
red to several genera by various authors. The genus Sanguinolites, by an
unwarrantable extension of its true characters and the disregard of the type,
has heretofore included many species of this group. Also, a few forms have
been placed in the genus Allorisma. They differ from both these genera in the
umbonal and post-cardinal ridges, their trapezoidal form, in the cincture cross-
ing the valves, and in the characters of the hinge.

Examples: Sphenotus arcceformis, pi. Ixv, figs. 7-11.

Sphenotus contractus, pi. Ixvi, figs. 1, 3-9, 11-13, 15 ; pi. xciv, fig. 2.

Spathella, n. g. [Type, Spathella typica. Hall.]

Shell equivalve, very inequilateral, wider behind, transversely sub-cylindrical.

Anterior end short, narrowly rounded. Beaks sub-anterior, small. Umbonal

slope rounded or sub-angular.
E

xxxiv SYNOPSIS OF GENERA.

Surfivce marked by concentric striae, which are often more or less lamellose.
Interior unknown.

The species referred to this genus were originally described as Sanguinolites.
In the absence of a knowledge of their internal characters, they may be dis-
tinguished from Sphenotus by their elongate sub-cylindrical form, widest at the
posterior end ; want of defined umbonal ridge, with no fold on the post-cardinal
slope. Sanguinolites, as illustrated and defined by McCoy, is synonymous in
part with Allorisma, although the first species under the genus does not show
this relationship.

The two species of Spathella described, in external form and markings, seem
to be related to the Lithophagi, but can be referred to no known genus.

Examples : Spathella typica, pi. Ixvi, figs. 36-40.

Spathella ventricosa, pi. Ixvi, figs. 41, 42.

Conocardium,* Bronn (Lethaea Geognostica, vol. i, p. 92. 1835).
[Type, Cardium Hibernicum, Sowerby.]

Shell equivalve, inequilateral, more or less fusiform or trigonal. Posterior end
obliquely truncate, produced along the cardinal line into a siphonal tube and some-
times the antero-inferior margin is also produced. Anterior end conicaland gaping
in front. Beaks prominent and strongly incurved. Ventral margins crenulated.
Cardinal line straight. Umbonal ridge prominent and ornamented with an
expansion of the test in continuation of the truncated posterior end.

Surface marked by concentric striae, and usually ornamented with strong radii.

Hinge with anterior and posterior laminar teeth [Barrande]. Ligament
external. Muscular impressions two in each valve, situated near the cardinal
extremities. Pallial line simple. In the anterior end there is a thickening or
internal process forming apparently a foot-sheath.

Examples: Conocardium cuneus, pi. Ixvii, figs. 1-32; pi. Ixviii, figs. 1, 4-16;
pi. xciv, figs. 11, 12.
Conocardium normale, pi. ixviii, figs. 17-19.

• Dr. LinilHti orii. of Stookhnlin, writes that he has been eiigag'ed in thi! stndy of Omocardiiim, by cutting
numerouR 8|>ecimen8. and finds that they have no i-elation to the CardiaUie, a fact before suspected and
believed by many persons, but never proved until the present time.

SYNOPSIS OF GENERA. xxxv

Panenka, Barrande (Syst. Sil. de la Boheme, pt. 1, vol. vi, p. 128. 1881).

Shell equivalve, more or less inequilateral, transversely or longitudinally
elliptical or sub-circular. Beaks prominent and incurved. Cardinal line straight
or arcuate. In some species there is a small triangular area beneath the beaks.
Lunule sometimes present.

Test thin. Surface marked by lines of growth, and usually by well-developed
radii. Interior unknown.

The species referred to this genus were formerly grouped under the genus
Cardiola, from which they differ as shown by Barrande in their more expanded
superior margins, and surface ornaments. Illustrations of a species of Cardiola
(C. fluduans, Barr.), are introduced on plates Ixx and xciv, for comparison with
the species of Panenka and allied genera.

Examples : Panenka multiradiata, pi. Ixix, fig. 5 ; pi. xciv, fig. 18.
Panenka Lincklceni, pi. ixix, figs. 12-14.
Panenka radians, pi. Ixix, fig. 9.
Panenka equilatera, pl. Ixix, fig. 4; pi. xciv, fig. 17.

Glyptocardia, n. g. [Type, Venericardium retrostriatum, von Buch ;=Car-
dium palmatum, Goldfuss;=Avicula speciosa. Hall.]

Shell small, equivalve, inequilateral, broadly elliptical or sub-circular. Beaks
anterior to the middle, incurved.

Surface marked by strong radiating plications and by concentric striae which
are often lamellose and arching over the radii. Interior unknown.

The small shells for which this genus has been proposed, are. of very wide
distribution, and have been referred by various later writers to the genus Car-
diola, from which they differ in their expanded cardinal margins, their surface
sculpturing, their minute size, and absence of a cardinal area beneath the

beaks.

Example : Glyptocardia speciosa, pl. Ixx, figs. 2-9 ; pl. Ixxx, fig. 10.

xxxvi SYNOPSIS OF GENERA.

Praecardium, Burrande (Syst. Sil. de laBoheme, pt. 1, vol. vi, p. 141. 1881).

Shell equivalve, more or less inequilateral, longitudinally or transversely
elliptical or trigonal. Beaks prominent and incurved.

Surface marked by concentric striae of growth, and by strong elevated
radii, separated by distinct interspaces.

Posterior to the beaks is a small area which carries a series of vertical
nearly parallel teeth. Other characters of the interior unknown.

The species of this genus differ from Panenka in the characters of the hinge,
and from Pararca in form, surface markings, and in the cardinal area posterior
to the beaks.

Example : Pracardium vetustum, pi. Ixx, figs. 18-20.

The genus is represented in America, so far as known, by the single species
cited above, occurring in the shales of the Portage group.

Paracardium, Barrande (Syst. Sil. de la Boheme, pt. 1, vol. vi, p. 137.

1881).

Shell equivalve, more or less inequilateral, sub-circular or broadly elliptical.
Posterior side sub-truncate, resembling in this respect some broad forms of
Lunulicardium. Valves moderately convex.

Surface marked by numerous fine radii with narrow interspaces, and by tine
striae of growth.

Under the beaks is a small cardinal area, the margin of which is minutely
crenulated. Muscular scars and pallial line unknown.

The shells of this genus differ from those of the genus Pararca in the pres-
ence of a cardinal area. Pararca has a longer hinge-line and more extended
line of crenulations, and the form is more transverse.

Example: Paracardium Doris, pi. Ixx, figs. 10, 11.

Pararca, n. g. [Types, Pararca venusta. Hall, and Pararca erecta, iBEall.]

Shell equivalve, inequilateral, transversely sub-elliptical or rhomboidal in
outline. Posterior end often sub-truncate. Anterior end short and rounded.

SYNOPSIS OF GENERA. xxxvil

Valves moderately convex. Cardinal line about half the length of the valve,
arching at the beaks. Urabonal slope often defined.

Surface marked by more or less slender radii with narrow interspaces and
by fine concentric striae of growth.

Hinge narrow and long, furnished with a series of minute crenulations.
Ligament apparently contained in a narrow groove along the cardinal border.
Muscular impressions and pallial line unknown.

This genus is distinguished by the transverse form of the species, the surface
chtaracters and the crenulations of the hinge, although this feature has been
seen but in a single species, probably on account of the specimens having been
preserved in sandstones and arenaceous shales.
Examples : Pararca vmusta, pi. xciv, fig. 22.
Pararca Sao, pi. Ixx, fig. 17.
Pararca ereda, pi. Ixx, fig. 16 ; pi. xciv, figs. 20, 21.

Cardiopsis, Meek and Worthen (Proc. Acad. Nat. Sci. Phila., p. 144. 1861).
[Type, Cardiomorpha radiata. Meek and Worthen.]

Right valve gibbous, inequilateral, obliquely ovate or sub-circular. Beak
prominent, incurved. Cardinal line short.

Surface marked by radiating striae or costae, and concentric striae of growth.

Hinge with one or two cardinal teeth. Ligament and muscular impressions
unknown.

Although in the original description of this genus the valves are said to be
equal, it is probable that the description was written from observations based
upon right valves alone.

A comparison of specimens of this valve with the corresponding valves in
the type-specimens of the genus Dexiobia, shows a great similarity in form and
surface characters, and it is probable that the two may prove to" be generically
identical. Also the genus Dualim (Barrande, 1881) seems to be congeneric
with Dexiobia.

Example : Cardiopsis radiata, pi. Ixx, fig. 25.

xxxviii SYNOPSIS OF GENERA.

Lunulicardium, Minister (Beithige zur Petrefakten-Kunde, 3d heft, p. 69.

1840).

Shell equivalve, inequilateral, longitudinally or transversely suh-elliptical,
sub-circular or trigonal. Posterior side obliquely truncate by the cardinal
hiatus, with the margin often reflexed and produced. Beaks pointed, sub-cen-
tral or anterior. Cardinal line marked by a lunate hiatus in each valve which
was probably occupied by the ligament.

Surface marked by concentric striae and usually by more or less well-devel-
oped radii with distinct interspaces. Some species also show a minutely pustu-
lose character of the surface.

Ligament external, occupying the hiatus of the cardinal line.

Hinge, muscular scar and pallial line unknown.

Examples : Lunulicardium curtum, pi. Ixxi, figs. 18-23.

Lunulicardium iransversum, pi. xciv, figs. 24, 25.
Lunulicardium fragile, pi. Ixxi, figs. 1-14.

Paracyclas, Hall (Geol. Surv. N. Y. ; Report of the Fourth District,
p. 171. 1843). [Type, P. elliptica.]

Shell equivalve, sub-equilateral, sub-orbicular or broadly sub-elliptical. An-
terior end regularly rounded ; posterior end rounded or sub-truncate, somewhat
more produced below than the anterior ; beaks small and low, generally rising
little above the hinge-line.

Hinge-line short. Post-cardinal slope more or less defined by an oblique
furrow or depression, which sometimes leaves the extremity sub-alate.

Surface concentrically striated ; sometimes with strong concentric ridges
marking the exterior.

Structure of. hinge not fully observed. Ligament supported on each side,
internally, by a narrow plate, and leaving in the cast two diverging grooves,
directed forward from the beak. Muscular impression on the post-umbonal
slope. Pallial line parallel with and a little within the margin of the shell.

SYNOPSIS OF GENERA.

XXXIX

This fossil possesses many of the external characters of the finely striated
forms of modern Lucina ; and the distinguishing characters are not strongly
marked.

The original specimen on which the genus was founded is somewhat vertically
compressed ; giving it an elliptical form. In well-preserved specimens the length
is but little greater than the height. The genus is very distinctly limited, and
usually easy of recognition among the Devonian forms of this class of fossils.

Examples : Paracyclas elUptica, pi. Ixxii, figs. 23-33 ; pi. xcv, fig. 18.
Paracyclas lirata, pi. Ixxii, figs. 2-19 ; pi. xcv, fig. 19.
Paracyclas tenuis, pi. Lxxii, figs. 20-22 ; pi. xcv, fig. 25.

Schizodus, King (Annals and Magazine of Natural History, vol. xiv, p. 313.
1844 ; Geology of Russia and the Ural Mountains, vol. ii, pp. 308-9. 1845 ;
Monograph of the Permian Fossils of England, pp. 185-8, pi. xv. 1850).
[Type, Schizodus truncatus. King.]

" Diagnosis. Equivalved, inequilateral, the posterior side being the longest.
Anterior outline rounded ; posterior tapering toward the extremity. Right
valve with two smooth cardinal teeth ; left valve with three teeth. The teeth
of the left valve placed in front of those in the right valve. The central tooth
of the former more or less bifid, according to species, on its free side, and
embraced by both teeth of the opposite valve. Pallial line entire ; smooth or
ornamented with fine raised lines, running parallel to the margin."

This genus was proposed, but not described, by Prof King in the Annals
and Magazine of Natural History, as above cited, in 1844, to include cer-
tain forms of the Permian and Carboniferous formations which had before
been referred to Axinus. The diagnosis given by De Verneuil in Geology of
Russia, etc., above cited, Mr. King regards as incomplete, and the results of
his own observations are given above.

The Devonian species of New York correspond in external characters with
the typical species of King, and in three of these we have been able to deter-
mine a corresponding hinge structure, and muscular impressions. The external

xl SYNOPSIS OF G ENEMA.

expression of most of the species of this genus is very characteristic, and there
is little ilifficulty in assigning them to their proper generic association.

At the present time we do not know of any species of the genus below the
horizon of the Upper Helderberg group. They are more numerous in the
Clienmng than in the Hamilton group, and several species have been observed
in the Waverly sandstone. The latter have a more extended and narrower
posterior end than the Chemung forms.

American examples : Schizodus tumidus, pi. xv, figs. 25-29.

Schizodus appressus, pi. Ixxv, figs. 3-9 ; and other species
of the same plate of this volume.

Prothyris, Meek (Proc. Acad. Sci. Phila., vol. xxi, p. 172. August, 1869).*

[Type, Prothyris elegans, Meek.]

Shell equivalve, inequilateral, extremely elongate ; cardinal and basal mar-
gins often sub-parallel ; anterior end rounded or sub-truncate, with a deep notch
in the antero-ventral margin. Posterior end rounded, lanceolate, or truncate.
Cardinal line straight or slightly arcuate. Cardinal slope sometimes sub-alate.
Umbonal slope rounded and undefined or sub-angular.

Surface of the shell marked by fine concentric striae of growth, and in one
species described, by fine radiating striae on the cardinal slope. Internal char-
acters unknown.

Two species of this peculiar generic form have heretofore been described.
The type is from the coal measures, and the other from the Waverly sandstone.
Four additional species are illustrated in the present volume, two of which are
from the Hamilton and two from the Chemung group ; one of the latter pre-
senting some peculiarities. The shells of this genus are thin and fragile, pre-

•The only <lt>8criptioii of thiHg-enus which I tiiul is the following, fi-om a footnote on the page above cited :
" It in a Hinall, Hm(M)th, compresseii, elongateii. equivalve bivalve, with nearly parallel, straight upper and
lower inargioH, and a distinct, rather Urge, rectangular notch in the aiit<!rior ventral margin, forming a
hiatus similar lo that seen in the genus XyUrphaga, though it evidently hius no relation to that group, but
Sfpms to \<e allied to the Solenidre. In Dr. Hayilen's Report on the Geology of Nebi-aska, I have proposed
for this genus the name ProViyris." The ReiMtrt on Nel)ra8ka, page 223, contains the following : " Pi-othyris,
Meek. 1869, Proc. Aca<l. Nat. Sci. Phila., July, p. 172."

SYNOPSIS OF GENERA. xli

senting an aspect unlike most other Lamellibranchiata, and in some aspects
having much the appearance of a bivalved crustacean.

From our present knowledge of these fossils they appear to form a peculiar
group, which may be termed Prothyridae.

Examples : Prothyris lanceolata, pi. Ixxvi, figs. 2-8.

Prothyris planulata, pi. Ixxvi, fig. 1; pl. xciv, fig. 8.
Prothyris data, pl. xciv, fig. 7.

Solemya, Lamarck (Hist, v, p. 488; 2d edition, vi, p. 123. 1818).

[Type, S. Australis — a recent shell.]

Shell equivalve, inequilateral, transversely elongate, obtuse at the extremi-
ties. Epidermis shining, extending beyond the margin of the shell. Beaks
not prominent, scarcely distinct. A cardinal tooth in each valve, dilated, com-
pres.sed oblique, sub-concave on the upper side to receive the ligament. Liga-
ment in part internal and in part external.

Prof. King (Monograph of the Permian Fossils of England, p. 177) has pro-
posed the generic name Janeia for the fossil species before referred to Solemya.
At a later period, however (in the appendix, pages 246, 247), he has given the
result of some further observations upon the recent and fossil species of the
genus, and concludes that the latter are true Solemya, and gives an emended
diagnosis of the genus.

The European fossil species of the genus occur in the Devonian of the Eifel,
in the mountain limestone of England, and in the Permian of Russia and of
England.

Example : Solemya vetusta, pl. xlvii, figs. 53-55 ; pl. xciv, fig. 10.

Tellinopsis, Hall (Prelim. Notice Lamellibranchiata, 2, p. 80. 1869-70).
[Type, Nuculites subemarginata, Conrad.]

Shell equivalve, sub-equilateral, sub-elliptical. Anterior end rounded. Pos-
terior end sub-truncate or emarginate. Beaks small, not prominent. Cardinal
line gently curved. Umbonal slope prominent and defined above.

xlii SYNOPSIS OF GENERA.

Surface marked by concentric striae of growth, and by radiating striae which
may be partially or entirely obsolete. Ligament external, small. Interior
characters of hinge and teeth undetermined. Muscular impressions sliallow.
Prtllial line undetermined.

This generic name has been proposed for a fossil species of the Hamilton
group, described by Mr. Conrad as Nuculites subemarginata (Journal of the
Academy of Natural Sciences, Phila., vol. viii, p. 249 ; pi. xv, fig. 5. 1842).
It is very distinct in external characters from any form of Nuculites in the
absence of the clavicle, which is usually shown near the anterior end, and
there is no evidence that the hinge is furnished with teeth of any kind.

The general expression of the fossil suggests its relationship to the Tellinidae.

Example: Tellinopm subemarginata, plate Ixxvi, figs. 21-31.

Cimitaria, Hall (Prelim. Notice Lamellibranchiata, 2, p. 66. 1869-70).
[Type, Cypricardites recurva, Conrad.]

Shell equivalve, extremely inequilateral, transversely elongate ; form solenoid,
falcate or elongate-trapezoid. Anterior end short and rounded. Posterior end
elongate, the extremity truncate. Beaks strongly incurved, umbones promi-
nent. ' Cardinal line straight or concave. Umbonal slope angular and often
strongly defined.

Surface marked by strong concentric lines of growth, which are simple or
lamellose, and by fine radiating strias, which may be more or less strongly
marked or altogether obsolete ; a more or less distinct depression or cincture
extends from the umbones in a slightly posterior direction to the basal margin.

The hinge is marked by a narrow, elongate, ligamental groove, and anterior
to the beaks is a strongly defined lunule. Ligament external. Teeth unknown.
Muscular impressions and pallial line undetermined.

The species placed under this genus are remarkable for their transversely
elongate forms, the greater portion of which is posterior to the beaks. Some
of the forms bear a resemblance to Orthonota, but the hinge-line shows a dis-
tinct ligamental groove and the anterior margin is rounded, with a well-defined

SYNOPSIS OF GENERA. xliii

lunule. The species are closely allied to Pholadella, and when more forms
become known it may prove convenient to unite the two genera. In some
important points the genus approaches to Grammysia by the way of Alhrisma.
The marked external ligamental area and strong lunule are common to the
three genera, while the surface markings have many points in common. In
the absence of critical knowledge of the hinge structure we are unprepared to
make any more positive assertion regarding this genus and its allied forms.
Examples: Cimitaria recurva, pi. Ixxvii, figs. 9-14.

Cimitaria elongata, pl. Ixxvii, figs. 5-8.

Cimitaria corrugata, pl-. Ixxvi, figs. 1-4.

Pholadella, Hall (Prelim. Notice Lamellibranchiata, 2, p. 63. 1869-70).

[Type, Pholadella Newberryi.]

Shell equi valve, inequilateral, transversely elongate, ovate, sub-elliptical or
trapezoidal. Anterior end rounded or obliquely truncate. Posterior end trun-
cate. Beaks much in advance of the middle of the valve, closely incurved.
Umbones prominent. Cardinal line straight. Umbonal slope prominent,
rounded or sub-angular. Cardinal slope flat or sub-alate.

Surface marked by fine concentric striae, and partially by strong concentric
undulations, which may be confined to the anterior portion or extend over the
body of the shell. Distinct radii, originating at the umbo, mark the central
and often the greater portion of the body, leaving the anterior end and cardinal
slope free from this ornamentation.

The cardinal margin is marked by a strong cartilage groove, and the anterior
end by a deep and sharply defined lunule. The characters of hinge-teeth, and
muscular impressions have not been determined.

The typical form of this genus bears many characters of the genus Cimitaria,
and others are closely allied, by external form, to Grammysia. Indeed so
close is this external relation that one species of the latter genus, having an
elongate form and somewhat peculiar surface markings, has been referred to
the genus Pholadella. Three well-defined species are illustrated in this volume.

xliv SYNOPSIS OF GENERA.

The relations of Grammysia, Allnrisma, Pholadella .and Cimifaria, though
apparent in their exterior ornamentation, require further knowledge of the
hinge and inttyior structure before their true affinities can be determined.

Examples : Pholadella Newbernji, pi. Ixxviii, fig. 25.

Pholadella radiata, pi. Ixxviii, figs. 15-21 ; pl. xcvi, fig. 1.

Phthonia, Hall (Prelim. Notice Lamellibranchiata, 2, p. 70. 1869-70).
[Type, Cypricardites sectifrons, Conrad.]

Shell equivalve, very inequilateral, elongate, sub-elliptical. Anterior end
short and rounded on the margin. Posterior end wider, prolonged, sub-trun-
cate above and rounded below. Beaks sub-anterior, small and appressed.
Cardinal line straight or slightly arched, ascending from the beak. Umbonal
slope rounded, more or less distinctly defined.

Surface marked by fine concentric striaa of growth, and by fine or coarser
ratliating striag, which may sometimes become obsolete.

The valves are united by a narrow, elongate, external ligament (shown in
fig. 13 of plate Ixxviii), but the hinge characters have not been ascertained.
The anterior muscular scars are small and not deeply impressed ; the posterior
scars are superficial. The pallial line is apparently without sinus.

Thus far we know the species of this genus only in the Hamilton and Che-
mung groups.

Six species have been identified, but the individuals of each one are compar-
atively rare. Apparently these forms are not closely allied with any other
genus among Devonian Lamellibranchs, and for the present constitute a distinct
group, which are not difficult of recognition.*

Examples : Phthonia cylindrica, pl. Ixxviii, figs. 1-4.
Phthonia nodicostata, pl. Ixxviii, figs. 5-9.
Phthonia sectifrons, pl. Ixxviii, figs. 10-13,

* Phthmtia lirata may be compared with Solemya.

SYNOPSIS OF GENERA. xlv

Orthonota, Conrad (Geol. Surv. N. Y., Annual Report on the Pateontological

Department, p. 50. 1841).
[Type, Orthonota undulata.]

" Equivalved, profoundly elongated. Hinge and basal margins straight and
parallel. Beaks near the anterior extremity ; posterior extremity truncated."

The above is Mr. Conrad's description. The shells, in all the species referred
to the genus, are extremely elongate and inequilateral; the anterior end is
rounded and the posterior end truncate. The beaks are near the anterior end.
The cardinal line is straight or sometimes slightly concave, extending nearly
the entire length of the shell. The umbonal slope is rounded or angular, and
defined by one or more distinct folds, which extend to the post-basal extremity.

Surface marked by fine striae of growth, and in the typical species by strong
undulations on the post-cardinal slope and less conspicuously on the anterior
end. Two or more defined oblique folds, which may be rounded or angular,
extend from the umbones to the posterior and post-basal margins.

Hinge characters unknown ; no teeth or crenulations have been observed.
Cardinal margin with a long linear fold embracing the ligament, which is
apparently internal. The anterior end is without lunule, and the margins of
the valves continue in a straight line beyond the beaks. The muscular impres-
sions are obscure, and have not been satisfactorily determined. Pallial line
undetermined.

The few species of this genus yet absolutely determined form a very distinct
group, and, so far as known, are restricted to the Hamilton and Chemung
groups. The first species designated by Mr. Conrad (Orthonota pholadis), from
the Hudson River group, is known to us only by a figure of the species, and
this is evidently not congeneric with O. undulata, which Mr. Conrad always
regarded as the typical species of the genus.

The characteristics of the genus have not always been fully understood or
appreciated by palaeontologists, and the inclusion of forms allied to, or identical
with, Grammysia by several European authors has served to mislead. The
species of this genus are always elongate, extremely inequilateral, without

xlvi SYNOPSIS OF GENERA.

external ligamental cicatrix or lunule, which are always marked features in the
Granimysidffi. Some of the species- referred to this genus by American authors
will ultimately be referred to other genera.

Examples : Orthonota undulata, pi. Ixxviii, figs. 37-42.
Orthonota carinata, pi. Ixxxiii, figs. 34, 35.

Palaeosolen, n. sub-genus. [Type, Orthonota siliquoidea. Hall.]

Shell equivalve, very inequilateral, extremely elongate, solenoid. Dorsal and
ventral margins sub-parallel. Anterior end short, rounded at the extremity.
Posterior end elongate, extremity truncate, gaping. Beaks sub-anterior, small,
appres.sed. Cardinal line straight. Umbonal slope prominent and extending
toward the post-basal extremity.

Surface marked by concentric striae of growth.

Hinge characters and teeth unknown. Ligament apparently internal. Mus-
cular impression and pallial line undetermined.

Surface (of the cast) marked by the remains of fine striae of growth.

The only species known has the general aspect of Orthonota, but the surface
is smooth with the exception of the striae of growth. The posterior end is
gaping and the anterior margin has the appearance of being slightly reflexed.

Example and type : Palaosolen siliquoidea, pi. Ixxviii, fig. 33.

Cypricardinia, Hall (Palaeontology of New York, vol. iii, text, p. 266.

1859. Prelim. Notice Lamellibranchiata, 2, p. 81. 1870).

[Type, Cypricardinia lamellosa, Hall.J

Shell inequivalve ; the right valve the more convex, very inequilateral ;
sub-rhomboid, obovate or sometimes trapezoidal, wider posteriorly. Anterior
end short, declining from the beaks and rounded below. Posterior end wider
and obliquely truncate. Beaks sub-anterior, incurved and appressed. Umbo
of the right valve often prominent. Cardinal line straight or arcuate, rising
from the besiks. Umbonal slope prominent, often obtusely angular.

Surface marked by strong, concentric, lamellose undulations, with interme-
diate fine striae of growth, and in some species by radiating striae, which are

SYNOPSIS OF GENERA. xlvii

interrupted at the outer margin of the lamellae. The valves are crossed
obliquely by a shallow byssal sinus.

Hinge-line marked by a long fold or lateral tooth in one valve. Cardinal
teeth not determined. Ligament external, strong, leaving in the cast a deep,
elongate groove. Anterior muscular impression small, situated just within the
anterior margin of the shell. Posterior muscular impression large and strong,
situated on the cardinal and umbonal slope a little behind the middle of the
length. Pallial line parallel with the margin of the shell.

The largest of our species is not known to reach a length of 30 mm., but
Mr. Billings has described C. distinda from the Gaspe limestone series, which
he says has a greatest length of seventeen lines.

This genus includes a very natural and characteristic group of shells,
which begin their existence in the Silurian rocks, and extend to the coal
measures ; occurring in the Trenton, Niagara, Lower Helderberg, Upper Helder-
berg, Hamilton, Chemung and Waverly groups. They are usually readily
recognized by their form, the inequality of the valves and the lamellose surface.
In the C. planulata, from the Schoharie grit, the umbonal slope is limited above
by a distinct furrow, which is more pronounced on the cast. In addition to the
ordinary concentric surface markings, some of the species show radiating
striae originating at the apex of the valve, and these are sometimes crossed
by others which are vertical to the direction of the lamellae. Of the species
originally described under this generic term, in the third volume of the Paleon-
tology OF New York, only C. lamellosa and C. crassa can be regarded as strictly
belonging to the genus.

This genus is well known in the Palaeozoic rocks of Europe.

Examples : Cypricardites planulata, pi. Ixxix, figs. 1-5.

Cypricardites indenta, pi. Ixxix, figs. 6-16, 23.

Palaeanatina, Hall (Prelim. Notice Lamellibranchiata, 2, p. 85. 1870).

[Type, Palaeanatina typa. Hall.]

Shell inequivalve ; left valve larger than the right, inequilateral, transversely
elongate, narrowly sub-elliptical or sub-trapezoidal. Anterior end short,

xlviii SYNOPSIS OF GENERA.

rounded or sub-truncate. Posterior end long, vertically or obliquely truncate,
or rounded at tbe margin. Beaks low, appressed, that of the left valve rising
above that of the right. Cardinal line straight or gently arcuate. Umbonal
slope prominent and extending to the post-basal extremity. A broad, shallow
depression extends from the umbo to the base of the valve, causing a shallow
sinus in the ventral margin.

Surface marked by fine concentric striae of growth.

Ligament partially external ; a ligamental groove, just within the dorsal
margin, extending nearly to the post-cardinal extremity of the shell. Hinge
furnished with two slender processes just beneath the beaks, and in one speci-
men a slender oblique fold extends backward from beneatli the apex ; no
lateral teeth have been observed. Muscular impressions indistinct; the anterior
one small, situated just forward of the beak ; the posterior one larger and near
the cardinal margin of the valve. Pallial line apparently parallel to and near
the ventral margin of the valve.

The shells of this genus are more distinctly characterized by the inequality
of the valves than by any other feature. The known species occur in a coarse
arenaceous matrix, which renders their condition unfavorable for a critical
study of the internal or external characters. These forms seem to have no
near allies among the associated fossils of the same or other formations.

Examples : Palaanatina ti/pa, pi. Ixxix, figs. 26-28, 35-37.
PaUzanatina solenoides, pi. Ixxix, figs. 38, 39.

Prorhynchus, n. gen. [Type, Palaeanatina quadrata, Hall. J

Shell inequivalve, the left valve the larger and more gibbous ; inequilateral, sub-
quadrsite or rhomboidal. Anterior end truncate, anguLar or nasute at the antero-
dorsal extremity. Posterior end broad, margin truncate or broadly rounded.
Beaks low, appressed, the umbo of the right valve somewhat gibbous and rising
above the hinge-line; beak of left valve scarcely above the cardinal line.
Cardinal line straight, extending the entire length of the dorsal margin,
and alate at both ends. Umbonal slope sub-angular, extending to the post-

SYNOPSIS OF GENERA. xlix

basal extremity ; post-cardinal slope often with an obscure or more or less
defined fold along the middle of its area.

Surface marked by more or less regular, fine concentric striiB of growth.

Hinge-line (in the cast) marked by a groove indicating a strong lateral tooth
or fold. There is likewise a groove along the hinge-line anterior to the beak
and a divergent furrow extending toward the anterior margin. Ligament
external. Muscular impressions and pallial line undetermined.

The species of this genus constitute a remarkable group of inequivalve shells.
Their geological position is in the upper part of the Chemung group, and the
only others which might be considered as having relations with them are the
Palseanatinae, which are similar in their inequivalve character.

The hinge characters cannot be fully determined, but the remarkable feature
of a cardinal line extending the entire length of the shell with a longitudinal
fold, which seems scarcely to be interrupted at the beaks, together with the
diverging anterior process or clavicle, are characteristic and peculiar features.

Examples : Prorhynchus quadratum, pi. Ixxix, figs. 40-49 ; pi. xcvi, fig. 5.
Prorhynchus nasutum, pi. xcvi, fig. 6.
Prorhynchus angulaium, pi. xcvi, fig. 7.

Glossites, N. GEN. [Type, Glossites lingualis, Hall.]

Shell equivalve, inequilateral, narrowly or broadly elliptical in outline. An-
terior end short, margin declining from the beak and curving below. Posterior
end large, narrowly or broadly rounded at the extremity. Beaks small and ap-
pressed, sub-anterior, or in advance of the anterior third. Cardinal line long,
gently arcuate. Umbonal slope not defined, prominent above and usually
merging into the general convexity of the surface about the middle of the length.

Surface marked by fine concentric striae of growth, which are often raised
into sharp sub-lamellose elevations, or more rarely by stronger concentric ridges.
Obscure radiating striae are rarely observed.

Hinge characters undetermined. There is evidence of an elongate lateral
tooth or fold, and the valves are joined by a strong external ligament. Lunule
distinct. Muscular impressions shallow.

1 SYNOPSIS OF GENERA.

The species of this genus apparently constitute a very natural group, since
they present such characteristic features of form and surface characters.

These shells have sometimes been referred to Modiomorpha and to Sanguinolites,
but they are clearly distinct from either, and cannot be properly referred to any
previously established genus.

Some of the species in their natural condition have had considerable con-
vexity, or even gibbosity, in the umbonal region ; but they are evidently thin
shells, and usually much compressed. The shell rarely preserves evidence of
radiating striaa, which are scarcely superficial.

Examples: Glossites teretts, pi. xcvi, fig. 15.

Qlossites lingualis, pi. xl, figs. 16, 17 ; pi. xcvi, figs. 9-11.
Glossites elliptictis, pi. xcvi, fig. 8,

Elymella, n. gen. [Type, Elymella nuculoides. Hall.]

Shell equivalve, inequilateral, ovate-elliptical. Anterior end very short and
the margin rounded. Posterior end narrower and rounded at the extremity.
Beaks closely incurved; umbo prominent. Cardinal line short. Umbonal
slope prominent in the upper part, not defined and merging into the general
convexity of the shell.

Surface marked by fine concentric striae of growth, which are sometimes
lamellose and elevated into concentric ridges.

Hinge-line short, the internal characters undetermined. Muscular impres-
sions unknown.

The small group of shells here termed Elymella cannot, with propriety, be
referred to any established genus, and therefore this name has been chosen in
reference to the form and expression of the fossils. The form of the shell and
the direction and character of the concentric striae resemble some species of
Nucula ; but although occurring with specimens of the latter genus showing the
hinge teeth, none of the specimens of Elymella have preserved any indication of
such characters.

Examples: Elymella fabalh, pi. xl, figs. 5, 9.

Elymella nuculoides, pi. xl, fig^. 6, 7, 8.

SYNOPSIS OF GENERA. U

Sanguinolites, McCoy (Carboniferous Fossils of Ireland, p. 47. 1844).

The following is Prof. McCoy's original description :

"Transversely oblong, convex, equivalve, very inequilateral. Basal and
ventral margins parallel or nearly so. Anterior end short, rounded. Posterior
side lengthened, obliquely truncate, gaping. An oblique ridge usually extends
from the beak to the anal angle, but no flexure ; ligament external."

" This genus has been formed to .include a number of fossil shells of the
older rocks, hitherto classed with Sanguinolaria. The latter shells have the
ventral and dorsal margins curving toward each other posteriorly, forming a
sub-mucronate beak-like termination to the posterior end, while on the con-
trary, the dorsal and ventral margins of the present shells are nearly parallel,
so that the posterior end is as wide or wider than the other parts of the shell ;
they are also much more gibbous and have no posterior fold."

By reference to the figures cited, or given in illustration of the forms of this genus,
it will be seen that they are not congeneric, and later authors in adopting the
name, and endeavoring to reconcile the difficulties, have not made the
matter more clear. On carefully reviewing the subject, and giving due
weight to the later expressions of Prof McCoy,* and to the illustrations which
he claims to be characteristic species of the genus, I find the reasoning which I
adopted fifteen years agof to be untenable, and therefore the group of species
then referred to Sanguinolites have received another generic designation.

One of the characteristic forms of the genus referred to by Prof. McCoy,
S. sulcatus, has been made the type of the genus Allorisma by Prof. King ; but
there still remains a group of shells with strong concentric ridges or undulations
of the surface, which are without posterior fold, or defined umbonal ridge, and
cannot be properly referred to Grammysia or Allorisma, but which correspond
with some of the forms referred to this genus by its author.

* British Palffiozaic Fossils, page 276. 1854.

t Preliminary Notice of the Laraellibrauchiata, 2, page 34.

lu SYNOPSIS OF GENERA.

Protomya, n. gen. (Palaeomya by error, in Explanation of Plate Ixiii ;
not Paloeomya, Zittel and Goulers). [Type, Protomya oblonga. Hall.]

Shell equivalve, inequilateral, elongate, ovate-elliptical. Anterior end broadly
rounded. Posterior end narrower and regularly rounded at the extremity.
Beaks incurved. Umbo prominent. Cardinal line long, nearly straight. Um-
bonal slope gibbous above, merging into the general convexity below.

Surface marked by fine striae of growth and strong concentric undulations.

Hinge characters unknown. Ligament external. Muscular impressions cir-
cular, the anterior one strong and situated near the anterior margin.

This form cannot with propriety be referred to any of the established genera
of palaeozoic fossils. It differs from Grammysia very distinctly in the absence
of a mesial cincture, umbonal ridge, and deep ligamental cicatrix; and less
strongly from Alhrisma in the same characters. The beak is more nearly cen-
tral than in either of these genera and the surface presents no evidences of
radiating striae.

Promacrus, Meek (Am. Jour. Conchology, vol. vii, p. 4. 1^71).

[Type, Promacrus Andrews!, Meek.]

Shell equivalve, sub-equilateral, elongate, sub-trapezoidal ; anterior end much
produced and narrowly rounded at the extremity ; posterior end more or less
produced, obliquely truncate. Beaks sometimes sub-central, appressed, rising
little above the cardinal line. Cardinal margin nearly straight behind the beaks,
and declining in front. Umbonal slope distinctly angular, extending to the
post-basal extremity and leaving a broiid cardinal slope above.

Surface marked by fine striae of growth which are often fascicled and raised
into more or less distinct undulations. The anterior portion of the shell is
marked by strong radiating interrupted striae or ridges, which give the surface
a cancellated appearance.

Hinge characters undetermined. There are evidences of teeth beneath the
beaks, but no hateral teeth have been observed. The ligament is external.
Muscular impressions unknown.

Examples : Promacrus Missourimsis, Swallow, sp.

Promacrus cuneatus, Hall, pi. Ixxviii, fig. 28.

SYNOPSIS OF GENERA. liii

Cytherodon, Hall (Twenty-third Report on the State Museum of Natural
History. Generic illustrations, pi. xiv, fig. 21. 1872).
[Type, Cytherodon nasutus. Hall.]

Shell equivalve, inequilateral, form rhomboid-ovate, gibbous; anterior end
short, declining almost vertically from the beaks and rounded below into the
basal margin. Cardinal line arcuate. Umbonal slope gibboUs, not defined.
Post-cardinal slope concave.

Surface marked by fine concentric striae of growth which become lamellose
below and posteriorly.

Hinge area strong, with several angular teeth or crenulations beneath and
anterior to the beaks. Posterior to the beaks the hinge-line is marked by a
deep ligamental groove. Anterior muscular scars distinct, just within the mar-
gin of the shell ; posterior one large and shallow, situated on the post-cardinal
slope. Pallial line simple.

The general form of this shell is similar to some species of Schizodus, but the
umbonal slope is less defined, the muscular impressions are not so strong, and
are differently situated. The hinge characters are entirely distinctive. Before
having learned the hinge structure of the American forms of the latter genus
I referred some of them to Cytherodon in the belief that they were generi-
cally identical. A further study of these forms has shown the hinge teeth and
muscular impressions corresponding to Schizodus. These differences may be
seen by comparing figs. 1, 2 and 3 with figs. 11 and 12 of plate Ixxv and with
fig. 30 of plate xcv.

The typical form is known in the Hamilton group of Maryland and New
York.

Type and example: Cytherodon nasutus, pi. Ix.w, figs. 11, 12; pi. xcv, fig. 30.

Uv SYNOPSIS OF GENERA.

Clinopistha, Meek and Worthen (Proc. Acad. Nat. Sci., Phila., p. 43. 1870).

Dystadella, Hall and Whitfield (Twenty-fourth Ann. Rep.

N. Y. St4ite Museum Nat. Hist., p. 192. 1872).

Compare Solemya, Lamarck. 1818.

[Type, Clinopistha antiqua. Meek.]

Shell equivalve, inequilateral, transversely sub-elliptical, obliquely truncate
in front, with a callosity or fold occupying the place of the lunule. Beaks
small, situated anterior to the middle. Anterior end oblique, often nasute
below. There is usually a broad shallow cincture extending from the beaks to
the base, sometimes constricting the margin.

Test thin. Surface, in the known species, marked by concentric striae of
growth. Internal characters not satisfactorily determined. Several specimens
have shown some indications of crenulations along the hinge, but this appear-
ance may be due to the crystallization, and subsequent partial solution, of tlie
margin of the shell. Ligament external. Muscular impressions of moderate
size, distinctly marked, situated near the margins of the valve. Pallial line
entire, composed of a series of radiating pustules as seen on the cast.

The species formerly referred to Dystadella appear, on further examination,
to be congeneric with Clinopistha, and it would seem that this latter genus does
not tliffer exteriorly from Solemya, except in the oblique anterior end and absence
of radii.

The type species has many points of resemblance to the species which was
made the type of Dystadella {D. subnasuta), and further collections may prove
their identity.

Example: Clinopistha subnasuta, pi. li.figs. 32, 33; pi. xcv, fig. 31.

Modiella, Hall (Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. Ixxvii, figs. 9-20. 1883).

[Type, Modiella pygmaea, Conrad, sp.]

Shell equivalve, very inequilateral, obovate. Anterior end short. Posterior
end very broad and curved, or obliquely sub-truncate at the extremity. Beaks
anterior. Cardinal line arcuate. Umbonal region prominent above, merging
into the general convexity below.

SYNOPSIS OF GENERA. Iv

Surface marked by fine concentric striae with some faint curving radiating
striae on the body of the shell.

Hinge marked by an elongate groove and fold. Ligament linear. Anterior
muscular impression just beneath the beak and occupying the upper part of the
distinct anterior lobe, which is separated from the body of the shell by a byssal
sinus. Posterior muscular impression large and shallow. Pallial line simple,
parallel to the margin of the shell.

The shell is, in all respects, very similar to some recent forms of Modiola.
Type and example : Modiella pygmaa, pi. Ixxv, figs. 9-20.

Megambonia, Hall (Palaeontology of New York, vol. iii, p. 273, and Twelfth

Report of the State Cabinet of Natural History, p. 12. 1859).

[Type, Megambonia cardiiformis. Hall.]

Shell equivalve or sub-equivalve, very inequilateral, obovoid, body very
oblique ; anterior end (in two typical forms) lobed ; posterior large, constituting
the principal part of the shell ; beaks anterior ; cardinal line short, sub-alate
posteriorly ; umbonal slope ventricose, not defined.

Surface marked by fine striae of growth, which in some species are crossed
by fine radiating striae. Hinge-line short ; a distinct lateral fold and groove
near the post-cardinal angle. Ligament internal. Anterior muscular impres-
sion large and strong ; posterior impression large.

The type of this genus is well marked, and its form and external characters
are very distinctive. It does not, however, show the anterior teeth or crenula,-
tions mentioned in the original description.

In the third volume of the Palaeontology of New York, several species are
described under this designation, which farther study has shown not to be con-
generic. At the present time the only forms which I regard as strictly belong-
ing to the genus are from the Corniferous limestone and Oriskany sandstone.
Those from the Lower Helderberg group require more material for a final
determination.

Examples : Megambonia cardiiformis, pi. iii, figs. 1-8.

Megambonia bellistriata, pi. cix, fig. 4 ; Pal. N. Y., vol. iii.
Megambonia ? lamellosa, pi. cix, figs. 5, 6 ; Pal. N. Y., vol. iii.

Ivi SYNOPSIS OF GENERA.

Amnigenia, lliill. (Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. xl, ligs. 1-4 ; pi. Ixxx, fig. 12).
[Type, Amnigenia Catskillensis, Vanuxem, sp.]

Shell equivalve, very inequilateral, elongate, sub-elliptical or narrowly sub-
obovate. Anterior end very short, the margin rounded. Posterior end pro-
longed and wider than the anterior, the extremity rounded. Beaks sub-
anterior, low and appressed. Cardinal line gently arcuate. Umbonal slope
convex, not.defined.

Surface marked with concentric striae of growth, which become lamellose on
the posterior portion of the shell. An obscure, broad depression extends from
anterior to the beaks, obliquely to the ventral margin.

Hinge-line long, marked by one or two lateral folds parallel to the dorsal
margin. Other characters of the hinge unknown. Ligament strong, external,
extending more than half the distance from the beak to the posterior end of
the shell. Anterior muscular impression large and prominent, situated just
anterior to the beaks. Posterior muscular impression large, shallow. Pallial
line .simple.

The specimens of the type species vary very much in form and proportions
from the conditions under which they have been imbedded in the matrix. The
specimens illustrated on plate xl, figs. 2, 3 and 4, and plate Ixxx, fig. 12,
although laterally compressed, appear to retain nearly their natural form and
proportions. The specimen fig. 1, of plate xl, represents a very common con-
dition of the fossil when the shell has been vertically compressed and the propor-
tions are distorted.

This genus does not possess characters which properly ally it with any of the
palajozoic marine families. From its occurrence with the remains of land plants,
and the absence of brachiopoda, and other marine life, in the rocks where it is
found, it would seem that the single species yet observed had its habitat in
fresh or brackish water, and is a primitive representative of the comparatively
recent genus Margaron.

Type and example: Amnigenia Catskillensis, pi. xl, figs. 1-4 ; pi. Ixxx, fig. 12.

SYNOPSIS OF GENERA.

Ivn

APPENDIX.

Observations upon the genus Pernopecten, and allied genera*
PERNOPECTEN, Winchell.

Pi-oc. Acad. Nat. Sci. Philadelphia, p. 125. 1865.

[Tyi>e Aviculopecten Hmifonnis, White and 'Whitaeld.]

In part EntoUum, Mbbk. Geol. Siii-v. California, vol. i, p. 479. 1865.

"Generic Characters. — Shell bivalve, sub-equivalve, monomyary. Valves
more or less inequilateral and auriculate. Hinge-line straight; hinge furnished
with a central, triangular cartilage-pit, and a transverse plate bearing on each
side of the middle, a series of smaller pits, diminishing in size and depth from
the centre outward. The shell seems to be thin, and probably has a structure
more like Peden than Perna."

Fig. 1. Pkrsopbctbn limifoumis. A view of the type specimen of the species and of the genus
Burlington sandstone. Burlingttm, Iowa.

Fig. 3. An enlargement to two diameters of the cardinal portion of the preceding as obtained from a
gutta-jienha impi-ession, showing more clearly the chai-actei-s of the hinge.

Fig 3. PBRNorEOTBN Shumardanus. An enlargement of the cardinal portion of one of the type speci-
mens of this species, showing the charactere of the hinge. Waverly group. Newark, Ohio.

* These observations were written in 1884 to accompany a general descnption and discussion of the
PalsBozoic Monomyaria, and fomied a part of the original plan for the introduction to the present volume.
The discu.ssions of the genera of the Monomyana have been deferred for the present, but as the genus
Pernopecten hau been recognized in the Report of the State Geologist for 1882, and also refei-red to in note,
p. 81, Pal. N. Y., vol. v., pt. 1, Lamellibranchiata, 1, it is necessary to introduce here the portion treating
of Pernopecten and allied forms.

Iviii SYNOPSIS OF GENERA.

Considerable confusion has arisen as to the validity and chariicters of the
genera Pemopecten and Entolium, and a short historical sketch, and critical dis-
cussion of these genera is here given.

1865. In the Report of the Geological Survey of California, vol. 1, Apjjen-
dix B, p. 478, Mr. Meek proposed the name Entolium as a subgenus of Amus-
vmts of Klein, for a species (E. aurarium) found in the auriferous slates of
California, and supposed to be of Jurassic age (pp. 477-479 ut cit.). The figure
illustrating this species is of a pectenoid shell, the external surface of which
presents the concentric striae without radii ; the internal characters not shown
nor described.

At the end of the description of Amussium aurarium Mr. Meek says : " This
species appears to belong to a group of thin lenticular, sub-equivalve, smooth
or concentrically marked shells, with short, equal, flat, obtusely angular ears,
which are not defined in either valve, or on either side, by a distinct marginal
byssal sinus. They differ from the typical species of Amussium, in having the
lateral margins closed, and the valves without internal radiating costae. This
group may be distinguished by the name Entolium, with Pecten demissus, of Phil-
lips (as figured by Quenstedt, in his Der Jura, i, tab. 48, f. 6 and 7), as its type."

1872. In the Final Report of the U. S. Geological Survey of Nebraska,
p. 189, Mr. Meek cites the genus Entolium and publishes under it E. avicula-
tum. Swallow sp.^Pec/en aviculatus. Swallow (Trans. St. Louis Acad. Sci., vol. 1,
p. 215. 1858). After describing the shell, Mr. Meek says: "This shell evi-
dently belongs to a group for which I proposed, in the California Report, the
name Entolium with Pecten demissus, Phillips (not Fleming), as illustrated in
Quenstedt's Der Jura, pi. 48, fig. 6, as the type." Mr. Meek illustrates E. avi-
culalum, pi. 9, fig. 11, and also copies from Quenstedt the hinge structure of
E. demissum, in illustration of the generic characters (ut cit., pi. 9, fig. 14).

1873. In the Report of the Geological Survey of Illinois, vol. V, p. 588, we
find the following : Genus Entolium, Meek. Entolium aviculatum. Swallow sp.,
pi. 26, figs. 12o, c.

Pecten aviculatus, Swallow, 1858. Trans. St. Louis Acad. Sci., vol. 1, p. 213.
Entolium aviculatum, Meek. Final Report on Neb., p. 189, pi. 9, figs. 11a, /.

SYNOPSIS OF GENERA. Ux

1875. Geological Survey of Ohio, vol. 2, pi. 11; PaljBontology, 292, Mr.
Meek describes Entolium Shumardianwn, WmcheWl (sp.), pi. 15, figs. Aa, b =
Pernopeden Shumardianus, Winchell (1865). Proc. Acad. Nat. Sci. Philad.,
xvii, 126.

Compare P. limatus, Winchell (1865), ib., and Avicula Cooperensis (1855), Mis-
souri Geol. Rep.

1877. Mr. S. A. Miller, Catalogue of American Palaeozoic Fossils, cites Ento-
lium avicula, Swallow, 1858 {Peden aviculus), Trans. St. Louis Acad. Sci., Coal
Measures, and E. Cooperensis, Shumard, 1855 {Avicula Cooperensis), Low. Carb.

1865. Professor A. Winchell describes the genus Pernopecten (Proc. Acad.
Nat. Sci. Phila., 1865,* p. 125.

The author founds the genus upon Aviculopeden limiformis. White and Whit-
field, from the Burlington sandstone of Iowa. Professor Winchell also includes
under this genus, Pernopecten limatus, and a new species from the base of the
Burlington limestone, together with Pernopecten Shumardianus, Winchell, which
he says is Avicula circulus. Hall (not of Shumard) with Lima ? nbsoleta. Hall,
Lima glaber, H., and mentions several European species. " It agrees with
" Amussium in its sub-symmetrical ears, central cartilage-pit, and the absence of
" radiating ridges, but differs in its straight hinge-line and lateral cartilage-pits.

" It is probable that in addition to the two following species, others referred
" to Avicula, Peterinea and more especially Aviculopeden, Amussium and Peden,
" will be found to possess the assemblage of characters shown in Pernopecten.
"Lima? obsoleta. Hall (Rep. 4th [10th in error] Dist. N. Y., p. 265) = Pecten
" sub-obsoletus, D'Orb., is stated to have a ' crenulated hinge-line,' while its
" external characters are quite conformable to Pernopecten. Not improbably
" Lima glaber. Hall, belongs to the same association. The same may be said of
" Peden densistria, Sandb., from the Posidonomt/enschiefer of Nassau ; Avicula
" tumida and Avicula lavigata, de Koninck, from the Carboniferous limestone of
" Belgium, etc., etc." [Proceedings Acad. Nat. Sci., Phila., July, 1865, pp.
125, 126.]

♦This publication bears the imiii'int of July, 186.'). The Geo\og\ca,\ Report of California, containing the
ori^nal description of Eutoliuiu, bears date of 1865, and the Preface is dated November, 1865.

Ix SYNOPSIS OF GENERA.

1866. Geological Survey of Illinois, Palaeontology, vol. II, p. 334. Under
the discussion of Streblopteria, Mr. Meek states that " Prof. Winchell has
proposed the name Pemopeden* (Proc. Acad. Nat. Sci., Phila., July, 1865,
p. 125), for a somewhat similar type. That genus, however, diflfers 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."

1868. Geological Survey of Illinois, vol. Ill, p. 453. Mr. Meek cites Pemo-
peden, Winchell (1865), with the species P. Shumardanus, Winchell ? pi. 14,
figs. 6a, b, and the following synonymy :

" Avicula drculus, Hall, 1858, Geological Report Iowa, vol. 1, part ii, p. 522,
pi. vii, fig. 9. " Not A. drculiis, Shumard, 1855, Missouri Report, pi. C, fig. 14.

"Pemopeden Skumardianus, Winchell, 1865, Proc. Acad. Nat. Sci., Phila., p. 126.

"Compare A. Cooperensis, Shumard (1855), Missouri Report, pi. C, fig.
" 15 = ? Aviculopeden limaformis, White and Whitfield (1862), Proc. Bos-
" ton Soc. Nat. Hist., vol. viii, p. 295.

1875. Geological Survey of Ohio, vol. 2, part ii. Palaeontology ; Mr. Meek
places Pemopeden Shumardanus, Winchell, under the genus EntoUum. See
citations under the latter genus.

1877. Mr. S. A. Miller cites in his Catalogue the following species, viz. :
Pemopeden crenulatus, H., P. Jasdculaius, H., P. glaber, H., P. limiformis. White
and Whitfield, P. limatus, Winchell, P. obsoletus, H., P. Shumardanus, Winchell.

From an investigation of the literature upon Pemopeden and EntoUum, and
a study of the type specimens of the former genus, it is evident that Pemo-
peden has priority and includes Peden demissus of Phillips. EntoUum, if existing
in nature, should be restricted to the species first indicated {E. aurarium), and
other allied forms, if any, and it is probably not found at all in the palaeozoic

• "The type of Pernopecten is P. dmpereiui'ui — (AviclUa Cwrperrnsis, Shumard,— Avicnloi)ecten Ihna/onnis,
White anil Whitfield). The ty|)ical specimen of this species, figured by Dr. Sliuiuard in the Mis.souri Report,
shows a few oWure radiating' costic— an exceedingly rare cliuracter, tliougli we have occa.sionally seen
faint indications of them on other specimens. Hence, Dr. Shumard's species hiw not been generally identi-
6ed, and Prof. Hall, in the Iowa Keport, p. 52'2, pi. 7, fig. 9, erroneously refei-s apparently the same shell
to Avicula circulug, of Shumanl, a quite ditfcrent species." [Meek.]

SYNOPSIS OF GENERA. Ixi

formations. The typical species of Pernopecien of Winchell, erroneously
included by Meek under Entolium, have a crenulated hinge-plate, although from
the nature of the matrix this feature is often obscure or concealed, and the
crenulations are easily abraded by friction.

Permpeden should, in addition to the typical species, include those which
were afterward referred to Entolium, and properly exclude some of the New
York species of the Chemung group.

Euchondria is "not well understood, although different from Auiculopeden
as usually characterized. At present it can only comprise the species described
as Aviculopeden negledus, Geinitz.

CRENIPECTEN, Hall.

PaL N. Y., vol. V, pt. 1. Plates and Explanations: p. 3. 1883.
[Type C. creniilatus, Hall.]

Shell pectenoid in general form ; anterior ear the larger. Surface smooth
or radiated. Hinge furnished with a series of small, sub-equal, ligamental
pits or vertical teeth throughout its entire length.

See plate ix, figs. 15 and 17 of C. crenulatus, and fig. 28 of C. WinchelU.

This genus was instituted to include a number of species in the Chemung
and Waverly groups, which have a continuous row of sub-equal cartilage-pits
along the margin of the hinge. In Permpeden there is a ridge on each side
of the cartilage-pit, sloping downwards and following the course of the lower
side of the ears. Also the row of ligamental pits is not in a straight line, but
elevated towards the extremities of the ears, and it is interrupted by the well-
marked central cartilage-pit.

The external form of several of the species referred to Crenipeden bears
considerable resemblance to some species of Streblopteria, but that genus has
a slender, oblique, posterior cardinal tooth, and the ligament is contained in a
simple narrow groove along the margin of the ears.

brii SYNOPSIS OF GENERA.

EUCHONDRIA, Meek.

Am. Jour. Sci., 3d ser., vol. vii, p. 445. 1874.
[Type Pecten neglectiis, Geinitz.]

" Mr. Meek states, in a letter to one of the editors, that he proposes to
institute the genus Euchondria for Pecten negledus of Geinitz, on account of its
peculiar hinge as illustrated by figure 7c, plate xxvi, in vol. v, of the Illinois
Geological Report."

This genus as illustrated by Mr. Meek {ut cit.) has an unsymmetrical sub-
rostral cartilage-pit, and the crenulations on the two sides are unequal.

If these characters can be shown in other specimens and other species, it is
probable that this genus will prove to be clearly distinct. At present it can
include only a single species, E. negleda.

The figures of this species given in the Palaeontology of Illinois, are intro-
duced for comparison with Pernopeden and Crenipeden.

Figs. 4, 5. EncHONDRiA neolbota (Geinitz, sp.). A i-eproduction of tigs. 7c and
7a, of plate xxvi, Geol. Surv. Illinois, vol. v. Fig. 4, a right valve, enlarged to
two diametei-s. Fig. 5, an enlargement of the hinge. Coal measures. Illinois.

S
Uflllufez'iiiftFni

LAMELLIBRANCHIATA.

i

I

LAMELLIBRANCHIATA

OF THE

UPPEK IIELDERBEKG, HAMILTON, PORTAGE AND CflEMUNG GROUPS.

II.

DESCRIPTIONS OF SPECIP:S.

MODIOMORPHA, Hall. 1870.
MoDioMORPHA Schoharie.

PLATE XXXIV, FIG. 13 ; and PLATE XXXV, FIG. 14.
Mudiomorpha f^hoharle, H.\ll. PaL N. Y., voL v, pt. 1. Plates and Explanations: PL 34, fig-. 13. 18S3.

Shell large, general form ovate, narrow in front; length one-third greater
than the height ; ventral margin broadly curved ; posterior margin abruptly
rounded. Anterior end obliquely truncate above, abruptly rounded below.

Hinge-line oblique, equal to two-thirds the height of the shell.

Beaks oblique, situated on the anterior fourth of the shell, depressed, rising
very slightly above the hinge. Umbonal region depressed convex.

Test marked by strong, irregular, lamellose striae of growth, which are
stronger on the anterior end and pallia! margins.

The muscular impressions are well-defined in the cast of the interior.
The anterior adductor is the smaller and situated in the lower portion of the
anterior end of the valve. The posterior adductor is sub-circular and located
in the lower portion of the post-umbonal slope. Pallial line deeply impres-
sed, following near to the ventral margin of the valve.
35

270 PALEONTOLOGY OF NEW YORK.

A small specimen preserving both valves has a length of 53 mm., height
38 mm., and depth of both valves 13 mm. A large right valve has a length
of 80 mm., and a height of 36 mm.

This species is distinguished by the comparatively great width of the valves,
the rounded ventral margins and the compressed form of the shell. It resem-
bles M. Clarens in general form, but the posterior end is not so regularly rounded,
and the valves are higher than in that species. In M. complanata the umbo is
more prominent, the anterior end narrower and rounded, the posterior end not
so regularly rounded, and the posterior muscular impression is farther within
the cavity of the valv«.

Formation and locality. In the Schoharie grit, Schoharie, N. Y.

MODIOMORPHA REGDLARIS, n. Sp.
PLATE XXXV, FIG. I'i.

Shell above the medium size, elongate, sub-elliptical ; length less than twice
the height; anterior margin abruptly rounded; ventral margin broadly
curved; posterior margin regularly rounded. Anterior end somewhat
narrow.

Valves depressed convex ; the point of greatest convexity being near the
middle of the length.

Hinge-line longer than the height of the valve, very slightly oblique.

Beaks depressed. Umbonal region moderately convex.

Test marked by strong concentric lamina) of growth. Interior luiknown.

A right valve has a length of nearly 70 mm., and a height of 40 mm.

This species differs from M. Schoharie in its more elongate form, longer hinge-
line and more rounded anterior end. It somewhat resembles certain forms of
M. mytiloides, but the hinge is not so oblique as in that species, the anterior end
is broader, and the ventral margin is more regularly curving.

Formation and locality. In the Schoharie grit, Schoharie, N. Y.

LAMELLIBRANCHIATA. 271

MODIOMOBPHA PUTILLUS.

PLATE XLI, FIGS. 1, 2.

ModUniwrpha putillus, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 41, figs. 1, 2. 18S3.

Shell small, sub-ovate, gibbous; height more than half the length; anterior
margin abruptly rounded ; base broadly curving. Anterior end convex, lim-
ited by a broad depression extending backward from a point just anterior
to the beak to the ventral margin.

Valves very convex and obtusely sub-angular along the post-umbonal
slope; the point of greatest convexity is a little anterior to the middle of
the length of the shell.

Hinge-line slightly oblique, somewhat longer than the height of the shell.

Beaks prominent, curving down to the hinge-line. Umbonal region
gibbous.

Test not preserved. The internal mould shows traces of strong concentric
laminae which probably marked the exterior shell.

Anterior muscular impression comparatively large, situated close to the
anterior margin. Pallial line strongly impressed. Other characters of the
interior unknown.

A specimen of normal form and preserving both valves has a length of 17
mm., height 10.5 mm., and depth of both valves 9 mm.

This species more nearly resembles M. neglecta of the Chemung group than
any other, but may be distinguished by its narrower form and less oblique
hinge-line.

Formation and locality. In the Schoharie grit, Schoharie, N. Y.

MODIOMORPHA (?) PONDEROSA.

PLATE XXXIV, FIGS. 11, 12 ; ANO PLATE XXXV, FIG. 8.

JSkmffulnolUett ponderomis, Kkhh. Prelim. Notice Lamellibranchiata, 2, p. 35. 1870.
MoMomorpha ponderosa, Hall. S. A. Miller, Cat. Ainer. Pal. Foss., p. 196. 1877.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 34, figs. 11, 12.

1883.

Shell large, rhomboid-ovate, gibbous ; length one-third greater than the height;
posterior margin broadly rounded; basal margin slightly concave toward

272 PALEONTOLOGY OF NEW YORK.

the anterior. Anterior end comparatively narrow and abruptly rounded,
limited by a broad depression extending from the beak to the basal margin
about one-third the length of the shell from the anterior extremity.

Valves very convex, gibbous in the middle and in the unibonal region ;
the greatest convexity is about the middle of the length, sloping toward
the posterior end more abruptly than toward the umbo. The depth of
l)oth valves is nearly equal to the height of the shell.

Hinge-line oblique, equal to two-thirds the length of the shell.

Beaks prominent, incurved, directed forward. Umbonal region gibbous,
rising considerably above the cardinal-line ; posterior slope sub-angular.

Test thick, concentrically striated ; its special characters unknown.

Muscular impressions large ; posterior impression situated on the cardinal
slope.

The specimen described has a length of 105 mm., height 70 mm., and the
depth of both valves is about 60 mm.

This species is distinguished by its rhomboid-ovate form, its great gibbosity,
and the prominence of the umbonal slope. The relations of this form with
MoDiOMORPHA are not satisfactorily determined.

Formation and locality. In the upper member of the Upper Helderberg lime-
stone, at Clarence Hollow, Erie county, N. Y.

MODIOMORPHA COMPLANATA,

PLATE XXXIV, FIG. 14 ; AND PLATE XLI, FIG. 3.

UodloiMirpha coiaplaiMta, Hall. Pi-elim. Notice Ijamellibranchiata, 2, p. 73. 1870.

" " Pal. N. Y., vol. V, pt. 1. PlaU's ami Explanations : PI. 34, fig. 14 ; pi. 38,

tiffH. 1-16. 1883.
" pennxUa, Hall. In eiTor. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 41, fig. 3,

1883.

Shell large, broadly sub-ovate; length one-third greater than the height; basal
margin very broadly rounded; posterior margin abruptly and regularly
rounded ; cardinal margin arcuate. Anterior end narrow, sub-truncate just
below the beak and abruptly rounded below.

Valves moderately convex ; greatest convexity anterior to the middle.

LAMELLIBRANCHIATA. 273

Hinge-line oblique ; length less than the height of the shell, merging into
the general curvature of the cardinal border.

Beaks sub-anterior, appressed. Umbonal region moderately convex, not
gibbous.

Test thick, marked by concentric laminae of growth.

Anterior muscular impression close to the lower anterior margin. Pallial
line essentially parallel to the basal margin. Posterior muscular impression
large, situated upon the post-cardinal slope at some distance from the margin
of the valve. The internal mould shows strong radiating grooves from the
pallial line toward the basal margin.

A large specimen has a length of 115 mm., and a height of 81 mm. A
somewhat smaller specimen has a length of 103 mm., a height of 71 mm.,
and the depth of both valves, in the cast, is 24 mm.

This species somewhat resembles M. maciknta, but is slightly more elongate,
much more regularly rounded posteriorly, the cardinal line more regularly and
broadly arched, the anterior extremity less produced, the beak more obtuse, and
the umbonal slope less defined.

The specimen fig. 3, plate xli, was erroneously referred to M. perovata, in Pal.
N. Y., vol. V, pt. 1, Plates and Explanations, but clearly belongs to the present
species.

Formation and localities. In the Corniferous limestone, six miles N.-W. of
Delaware, 0. ; and Babcock's Hill, Herkimer county, N. Y.

MoDiOMORPiiA Clarens, n. sp.

PLATE XLI, FIG. 4.

Modiomorp/ia ptiomia (M. & W.), sp.. Hall. Pal. N. Y., vol. v, i)t. 1. Plates and Explanations : PI, 41, fig. 4.
Not Modiolopsm perovata, Mkkk & Wobthkn. Pi-oc. Acad. Nat. Sci., p. 246. 186.").

t " " " Pal. Illinois, vol. iii, p. 438 ; pi. 11, fig. 2. 1868.

Shell of medium size, ovate, sub-elliptical ; length nearly one-third greater
than the height; basal margin broadly curving (too straight in the figure);
posterior margin regularly rounded ; cardinal margin arcuate. Anterior end

274 PALAEONTOLOGY OF NEW YORK.

abruptly rounded below and sub-truncate above, produced considerably
beyond the beaks.

Valves moderately convex; the point of greatest convexity is a little
anterior to the middle.

Hinge-line oblique ; length less than one-half the length of the shell.

Beaks small, appressed. Umbonal region moderately convex, gently
merging into the general surfiice of the shell.

Test strong, marked by regular laminae of growth and fine concentric
striae. Interior unknown.

The specimen described has a length of 65 mm., and a height of 42 mm.

The shell is proportionally longer than in M. Schoharie and not so broad
posteriorly. It is not so extended anteriorly as in M. madlmta and M. mytiloides,
and not so prominent in the umbonal region. Compared with M. alta, the
liinge is shorter, less oblique, posterior margin much more regularly rounded,
basal margin more convex, .and the umbonal slope less distinctly defined. A
larger collection of specimens for comparison may show that this species has a
near relation to M. complanata.

This species has been identified with M. perovata, but a comparison shows it
to differ in the broader arcuation of the basal margin and the greater exten-
sion of the anterior end.

Formation and locality. In the upper member of the Upper Helderberg
gi-oup, Clarence Hollow, Erie county, N. Y.

MODIOMORPIIA LTNGUIFORMIS.

PLATE XXXIV, FIGS. (15?) 16, 17.

Modunnorplia HnffuifarmU, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 34, fijfs. 15-17.

1883.

Shell of medium size or larger ; form sub-elliptical ; length less than twice
the height; basal margin gently curving; posterior margin abruptly rounded;
cardinal margin arcuate, greatest elevation near the middle of its length.
Anterior end abruptly rounded, extending but little beyond the beaks.

LAMELLIBRANCHIATA. 275

Valves convex, not gibbous ; greatest convexity about the middle of the
shell.

Hinge-line oblique, extending for more than half the length of the shell.

Beaks sub-anterior, not prominent, directed forward. Umbonal region
convex, sometimes approaching to gibbous, not strongly defined.

Test thick, marked by concentric striae.

Anterior muscular impression strong. Pallial line, in the cast, marked by
a ridge extending parallel to the basal margin.

A medium-sized specimen has a length of 60 mm., and a height of 35 mm.

This form is proportionally longer than M. Schoharie, and broader than M.
cymhula, which is also sub-nasute on the posterior end, with more depressed
beaks.

Formation and localities. In the limestone of the Upper Helderberg group,
near Columbus, 0., and Cayuga, Ont.

MODIOMOKPHA CONCENTRICA.

PLATE XXXIV, FIGS. 9,10; PLATE XXXV, FIGS. 1^; and PLATE XXXVI, FIGS. 1-16 (17, 18?).

PteHneaeoneentrica, Conrad. Geol. Surv. N. Y., Ann. Rep., p. 116. 1838.
Oyprieardites eoneeiUrica, Cosbad. Geol. Surv. N. Y., Ann. Rep., p. 52. 1841.

" oblonga, " Geol. Surv. N. Y., Ann. Rep., p. 52. 1841.

Modiola concentrica, " Hall. Geol. Sui-v. N. Y., Rep. Fourth Dist., p. 196, tab. 78, fig. 9. 1843.

Modioinorpha concentrica, " " Prelim. Notice Lamellibranchiata, 2, p. 73. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 34, figs.

9, 10 ; pi. 36, figs. 1-16 (17, 18 ?). 1883.

Shell of medium size, ovate, extremely variable in its proportions ; length less
than twice the height ; basal margin often nearly straight, usually a little
concave on the anterior third ; posterior margin abruptly rounded below
and more gently curving above ; cardinal margin oblique in the prevailing
forms, moderately arcuate, often nearly straight, sub-alate in many specimens.
Anterior end produced beyond the beaks, abruptly rounded, sometimes
nasute, limited by a broad depression extending from the beak to about the
anterior third of the basal margin.

Valves moderately convex, gibbous along the umbonal slope ; the point of
greatest convexity is about the anterior third of the length of the shell.

276 PALEONTOLOGY OF NEW YORK.

Hinge-line extending half, or sometimes more than half, the length of the
shell.

Beaks sub-anterior, small, sharply angular, appressed, directed forward.
Uml)onal region a prominent sub-angular elevation, extending obliquely from
the beak toward the post-basal margin, usually dying out about the middle
of the length of the shell.

Test comparatively thick, strongly ornamented by regular concentric,
rounded or sub-angular striae, which become lamellose and coalescing on the
anterior end of the valves, where they are less prominent.

Anterior muscular impression strong, striated, situated just within the
anterior margin, with a small retractor scar above it. Posterior impres-
sion large and shallow. Pallial line moderately impressed. Hinge furnished
with a strong cardinal tooth just posterior to the beak in the left valve, and
a corresponding depression in the right valve. No proper lateral teeth have
been observed, but the cardinal margin is thickened and grooved from the
beak backward about half the length of the cardinal line.

Several specimens showing the ordinary range of form have the respective
lengths of 50, 40, 40, 30, 52, 63, 68 mm., and heights of 27, 25, 30, 22, 32,
38, 38 mm.

This species resembles M. mytiloides, but may be distinguished by its usually
smaller size in full-grown specimens, more prominent umbonal region, more
arcuate form, less prominent anterior end, and by the strong, regular, concentric
striae. It is a more elongate form than M. alta.

Formation and localities. In the shales of the Hamilton group from the eastern
portion of the St^ate ; al)undant in the central portion of the State, and less
abundant in the softer calcareous shales in the western part of the State of
New York ; in the siliceous layers above the hydraulic limestone at the Falls
of the Ohio, at Charleston, Ind., and in the shales of this group, near Cumber-
land, Md.

LAMELLIBRANCHIATA. 277

MODIOMORPHA MYTILOIDES.

PLATE XXXVII, FIG. 3; and PLATE XXXVIII, FIGS. 1-16.

CypHcardites mytihidfs, Conrad. Geol. Smv. N. Y., Ann. Rep., p. 52. 1S41.

Modiomoryha complanata. Hall. In error. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 38,

fijfs. 1-16. 188:^.
Modi-iaorpJia plannlata, " Pi-elim. Notice Laniellibranchiata, 2, p. 74. 1870.

Shell larger than the medium size, rhomboid-ovate, oblique; length less than
twice the height; basal margin nearly straight, or very slightly concave
anterior to the middle, curving to the anterior and ;posterior extremities;
posterior margin abruptly curving below and more gently recurving toward
the cardinal line ; cardinal margin arcuate. Anterior end narrow, extended,
abruptly curved on the margin; somewhat defined by the sinus which extends
from anterior to the beak to the middle of the shell.

Valves moderately convex ; in old shells gibbous in the umbonal region.

Hinge-line oblique, extending to about the middle of the length of the shell.

Beaks appressed, situated a little more than one-fourth the length of the
shell from the anterior end. Umbonal region not defined ; convex in young
shells, becoming more gibbous in older individuals.

Test of moderate thickness, concentrically striated with irregular lines of
growth which are sometimes elevated into concentric ridges. The post-
cardinal slope in well-preserved specimens shows fine vascular markings
similar to those on Sphenotus soknoides.

The anterior muscular impression is well marked and situated just within
the anterior margin below the beak. Other interior characters unknown.

The specimen fig. 13 of plate xxxviii preserves the ligament connecting
the two valves.

Three characteristic specimens have the following dimensions : Length 50,
60, 91 mm. ; height 29, 37 and 50 mm. respectively.

The individuals of this species from medium size upward resemble M. con-

cenlrira in form, but the anterior end is more produced and they do not show

the regular sharp concentric striiB which mark that species. It also resembles

some forms which are referred to M. alia, but may be distinguished by its more

36

278 PALEONTOLOGY OF NEW YORK.

elongate form, more regularly convex umbonal slope, more regularly rounded
posterior extremity, and narrower anterior end.

This is probably the species described by Mr. Conrad as Cypricardites myti-
loides, of which he gives the following description :

" C. mytiloides. Ovate, slightly ventricose ; lines of growth prominent; umbo
prominent ; dorsal margin elevated ; anterior basal margin very oblique and
slightly contnicted ; posterior side profoundly dilated and the margins regularly
rounded. Locality. Near Ogden's Ferry, tab. of forui. No. 2o."

Formation and localities. In the shales of the Hamilton group ; jjrincipally in

the eastern and central portion of the State, on the shores of Seneca and

Cayuga lakes.

MODIOMORPHA ALTA.
PLATK XXXVII, FIGS 1, 2 (4, 5, 6?), 7-li, l."!, 16; ANI> PLATE LXXX, FIG. 7.

Cypricarditts alta, Conrau. Geol. Surv. N. Y., Ann. Rep., p. 52. 1841.
JUtidiomorpha alta, (Conbad) Hall. Prelim. Notice Lamellibranchiata, 2, p. 75. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 37, figs. 1-16 ;

pi. 80, fig. 7. 1883.

Shell larger than the medium size, broad, rhomboid-ovate ; length one-third
greater than the height ; the basal margin for two-thirds of its length from
the anterior curve is nearly straight, varying from slightly concave to nearly
straight, abruptly curving at the post-basal extremity, and continuing to the
post-cardinal margin in an oblique, gently curved outline. In some examples
the posterior margin is regularly curved, cardinal margin sometimes form-
ing a nearly straight line, usually gently arcuate. Anterior end produced
beyond the beak from one-sixth to one-fourth the length of the shell,
obliquely truncated, obtuse, rounded below ; its greatest extension is below
the middle of the shell.

Valves convex, gibbous on the umbonal and medial portions of the
shell ; the umbonal ridge is gibbous and arched upward ; the point of
greatest convexity is about the middle of the shell or a little posterior.
The depth of both valves is equal to two-thirds of the height of the shell.

Hinge-line straight, oblique, extending for less than half the length of
the shell.

LAMELLIBRANCHIATA. 279

Beaks rounded, somewhat appressed, directed forward. Umbonal region
not strongly defined, depressed anteriorly, becoming gibbous in the middle
of the shell, gradually merging into tlie general contour in the posterior
portion.

Test of moderate thickness, marked by irregular concentric striae, which
become fasciculate and produce strong concentric ridges at irregular
intervals. The surface is marked by fine vascular lines, similar to those
referred to in M. mytiloides. The anterior muscular impression is situated
close to the anterior margin of the shell, with a small retractor scar above it.
Other characters of the interior unknown.

The type specimen has a length of 68 mm., and a height of 46 mm.
Three other specimens measure respectively, 65, 55 and 67 mm. in length,
and 45, 37 and 42 mm. in height.

This species has a greater proportional height than M. mytiloides, a broader
and often sub-truncate posterior end, while the anterior end is usually broader
and less extended ; the umbonal ridge is arcuate ; in other features it is very
similar. The form does not attain so large a size as M. macilenta ; it is more
ventricose in the umbonal region, the hinge-line is longer and the striae are
more irregular. In some of its conditions this species approaches M. mytiloides,
and it is not always easy to distinguish them.

This species shows a tendency to assume extremely gibbous and sometimes
distorted forms, as shown in fig. 2 of plate xxxvii and fig. 7 of plate Ixxx.
The specimen fig. 15 of plate xxxvii, is the type of this species.

Formations and localities. In the shales of the middle portions of the Hamilton
group at many localities in the eastern and central part of the State, and
especially on the shores of Seneca and Cayuga lakes ; in the Hamilton group
at the Falls of the Ohio, and Charleston, Indiana. Small individuals having
the characteristics of this species occur in the Marcellus shales near Skanea-
teles, N. Y.

280 PALEONTOLOGY OF NEW YORK.

MODIOMOEPHA MACILENTA.

PLATE XXXVII, FIG. 17; and PLATE XXXIX, FIOS. 1111.

Uodimnorpha macileiita. Hall. Pi-elim. Notice Laiiiellibi-andiiata, 2, p. 7ti. 1870.

" " •• Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 37, fig. 17; pi. M9,

Rgs 17-21. 1883.

Shell large, rhomboid-ovate ; length one-third greater than the height; basal
line nearly straight for more than half its length and abruptly curving both
anteriorly and posteriorly. Posterior end oblique, more gently curving from
the post-basal margin to the cardinal line, which is oblique and arcuate. An-
terior end short, rapidly declining and abruptly rounded below.

Valves moderately convex ; greatest convexity in the umbonal region,
gradually merging into the general convexity of the valves.

Hinge-line extending about half the length of the shell, slightly arcuate.

Beaks small, sub-anterior, appressed, scarcely rising above the cardinal line.

Test thin, marked by regular concentric striae which are scarcely fasciculate
on any portion of the shell. The surface shows the irregular vascular mark-
ings of other species of this genus, and of some of the species of Spiienotus.

The anterior muscular impression is strong, situated a little anterior to
the beak and just within the margin of the valves.

Three specimens have the following dimensions respectively : Length 90,
102, 108 mm.; height 60, 65 and 75 mm.

All the individuals which have been recognized as of this species are of
comparatively large size, and bear considerable resemblance to the larger
individuals of M. alta, but may in general be distinguished by their less convex
valves, less defined umbonal ridge, usually more rounded posterior extremity,
and finer and more regular concentric striae.

The typical forms here recorded under the specific designations of M. myliloides,
M. dlta and M. macilenta, are easily distinguishable ; but in the study of large
collections we find so many intermediate forms that it becomes difficult, if not
impriu!ticable, to arrange them under these several designations.

Formation and localities. In the soft calcareous shales of the Hamilton group,
shores of Canandaigua lake. North Bristol, Ontario county; Bellona, Yates
county; and York, Livingston county, N. Y.

LAMELLIBRANCHIATA. 281

MODIOMORPHA ARCUATA.

PLATK XXXVI, FIG. 21.

ModimnorpJta arcuata. Halt.. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 30, fig. 21. 1S83.

Shell of medium size, obliquely sub-spatulate or narrowly and obliquely
elongate-ovate; length more than twice the height; basal margin arcuate,
the greatest concavity a little more than one-third of the length from the
anterior end ; post-basal extremity abruptly rounded and more gently recurv-
ing to the cardinal margin, which is nearly straight and extends for about
one-half the length of the shell. Anterior end produced, nasute, the margin
abruptly rounded, limited by a sinus which extends to the base, more than
one-third the length of the shell from the anterior end.

Valves depressed convex in the posterior half, becoming gibbous and sub-
angular on the anterior half.

Hinge-line oblique, straight,, extending for less than half the length of
the shell.

Beaks small, sub-anterior, pointed, closely appressed and angular. Umbonal
region prominent, gibbous, sub-angular, the angularity extending for more
than two-thirds the length of the shell.

Test thin, with fine, thread-like concentric striae. The striae coalesce,
scarcely forming fiiscicles along the base and cardinal slope. Anterior mus-
cular impression sub-circular, close within the anterior margin of the shell.

The specimen described has a length of 66 mm., and a height of 25 mm.

This species is narrower and more elongate than any other form of the genus,
and is only approached by some of the extreme varieties of M. concentrica. It
bears very little resemblance to any known species found in the rocks of this
age, and is an extremely rare form, a single specimen only having occurred in
all the collections made in this horizon.

Formation and locality. In the harder arenaceous shales of the Hamilton
group at Bear's gulf, Schoharie county, N. Y. It is associated with Spirifera
mucronata, Rhynchonella congregata, and Chonetes coronata.

282 PALEONTOLOGY OF NEW YORK.

MODIOMORPHA CYMBULA.

PLATE XXXVI, FIGS. 19, 20.

MtMomorpha cynilmJa, Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 75. 1870.

•• " • " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 3(i, figs. 19, 20.

1883.

Shell of medium size, elongate, sub-elliptical ; length a little more than twice
the height ; basal margin regularly convex, acutely rounded at both extrem-
ities ; cardinal line regularly curving from the beaks to the posterior
extremity. Anterior end narrow, sub-nasute, without special limitation.

Valves moderately and regularly convex, the greatest convexity being
about the middle of the length.

Hinge-line oblique, curving ; length a little less than half the length of the
shell.

Beaks sub-anterior, small, narrow, acute, closely appressed. Umbonal
region moderately convex, without any defined ridge, but the prominence
extends parallel to the cardinal line for more than two-thirds the length of
the shell. The anterior side of the umbonal region is flattened or depressed
in the cast, the depression extending downward nearly to the base, but not
affecting the margin.

Test comparatively thick ; surface markings not preserved. The anterior
muscular impression is strong and large, with a small and deep retractor
scar. Pallial line parallel with the basal margin, abruptly recurving at the
posterior end and terminating in a large, shallow posterior adductor
impression.

The specimen has a length of 60 mm., and a height of 28 mm.

This form is more elliptical than any of the preceding species of the
Hamilton group, but is not so symmetrically elliptical as M. regularis and
M. linguiformis of the Helderberg limestone. It is distinguished from all the
species of the genus by its narrow and acute anterior and posterior extremities.
The species is of extremely rare occurrence, a single specimen only having
been observed in all the collections.

LAMELLIBRANCHIATA. . 283

Formation and locality. In the arenaceous shales of the Hamilton group, at
East Worcester, Otsego county, N. Y., associated with characteristic Hamilton
fossils.

MODIOMORPHA SUBALATA.

PLATE XXXV, KIGS. 6, 7 ; AND PLATE XXXLX, FIGS. 1-U, 16.

Cypricardites gubalata, Conrad. Geol. Sui-v. N. Y., Ann. Rep., p. 83. 1841. ^
Modiotnorpha subcUata (Cosbad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 77. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 39, figs.

1-14, 16. 1S83.

Shell of medium size or smaller, sub-quadrangular, or sub-ovate; sub-alate
posteriorly, with the extremity obliquely truncate ; length more than one-
third greater than the height ; basal margin straight or slightly concave on
the anterior half, and thence regularly curving to the post-basal extremity ;
posterior margin abruptly recurved below, and continuing with a gentle
curvature, or in a nearly straight line, to the cardinal margin ; cardinal mar-
gin oblique, nearly straight; post-cardinal area sub-alate. Anterior end
short, abruptly rounded, often a little concave below the beaks, and limited
by a more or less defined sinus, which extends from the beak to the basal
margin, usually at a point less than one-third the length of the shell from
the anterior end.

Valves moderately convex below and in the posterior portion, more convex
in the middle.

Hinge-line oblique, about half the length of the shell.

Beaks sub-anterior, incurved and directed forward, somewhat compressed.
Umbo prominent, flattened anteriorly ; the post-umbonal slope angular, gib-
bous above and gradually declining to the post-basal extremity, which is
sometimes obtusely angular.

Test thin, marked by fine concentric striae, which are sometimes fascicu-
late, forming distinct elevations upon the posterior slope, and often distinct
angular striae upon the antero-basal portion of the shell, frequently becom-
ing nearly obsolete on the umbonal region.

Anterior muscular impression circular, of moderate strength ; other interior
characters undetermined.

284 PALEONTOLOGY OF NEW YORK.

A medium-sized specimen has a length of 38 mm., and a height of 23
mm. A hirge individual mejisures 53 mm. in length and 29 mm. in height.

This species differs from any of the preceding forms in the more nearly
parallel cardinal and basal margins, in the angidar umbonal ridge, more direct
truncation of the posterior end, and the obsolescence of the strias on the um-
bonal region. As compared with M. rigida the basal margin is straighter, the
anterior end is wider, and the cardinal line less oblique.

Formation and localities. In the middle and upper portions of the Hamilton
group, at numerous localities in the central and western part of the State.

MoDiOMORPHA SUBALATA, var. Chemungensis, n. var.

PLATE XLI, FIGS. 5, 6, 8, 9, 11 (7, 10?) ; AND PLATE XXXIX, FIG. 15.

Modioinorpha rigida, in part. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 41, Bjfs. 10,

11. 18S3.

This variety includes the specimens from the Chemung group, and presents
the principal characteristics of the species. The forms are longer in proportion
to their height, the cardinal line less oblique, the posterior extremity usually
more rounded, the umbonal slope more arcuate, and the striae are filiform,
sharper and more regular. Although presenting these differences, it does not
appear advisable to propose a distinct specific name.

The specimens present considerable variety among themselves, as is seen by
reference to figs. 6, 7 and 10 of plate xli as compared with figs. 5 and 11 of
the same plate. A larger collection of specimens may afford the means of
a more positive separation of these forms from those of the Hamilton group.

Formation and localities. In the lower portion of the Chemung group, at
Ithaca and Cortland, N. Y.

MODIOMORPHA AFFINIS, n. sp.
PL.VTE XXXVII, FIGS. IS, U ; AND PLATK XXXV, FIG. 13

Mudimnorpha alta, in part {Coskkd), Hall. Pal. N. Y., vol. v. pi. 1. Platf.s mul Kxplanations: PI. 37,

figs. 13, 14. 1883

Shell large, robust, obliquely ovate, arcuate ; length about one-third greater
than the height ; basal margin straight or slightly arcuate, curving rather

LAMELLIBRANCHIATA. 285

abruptly both at the anterior and posterior extremities ; posterior margin
abruptly curving below and more gently forward to the cardinal margin ;
cardinal margin arcuate from the beaks to the post-cardinal extremity.
Anterior end short, scarcely defined, narrow, declining from the hinge-line
and regularly rounded below.

Valves convex, very gibbous in the middle and umbonal region ; depth
more than half the height of the shell. The umbonal elevation extends
from the beaks, curving above the middle, to near the post-basal margin,
forming an undefined arcuate ridge.

Hinge-line oblique, extending more than one-third the length of the valves.

Beaks small, sub-anterior, closely incurved.

Test comparatively thick, marked by fine concentric striae, which are fas-
ciculate and raised into strong abrupt ridges upon the umbonal and anterior
portions of the shell. Interior unknown.

The principal specimen described has a length of 70 mm., height 41 mm.,
and a depth in both valves of 29 mm. A smaller specimen referred with
some doubt to this species has a length of 50 mm., height 32 mm., depth 21
mm. This specimen shows a strong anterior muscular impression with an
accessory pit, and also a shallow posterior muscular scar on the post-cardi-
nal slope.

This form resembles M. alta, but is more elongate, distinctly arcuate ; the
anterior end is narrower below the beaks ; the posterior end is more produced
and curving more abruptly forward in the upper part, with the post-cardinal
angle rounded. The anterior end is less produced than in typical forms of M.
mytiloides.

Formation and localities. The original specimen is recorded as coming from a
compact limestone in the Hamilton group of Onondaga county, N. Y. The
small specimen referred to is from the Hamilton group in Clarke county, Ind.
37

286 PALAEONTOLOGY OF NEW YORK.

MODIOMORPHA RECTA, n. Sp.

PLATE X«XV, FIG. 9. - '

Shell of medium size, sub-ovate ; length less than twice the height ; basal
margin nearly straight, or gently convex, curving abruptly at the anterior
and posterior extremities. Posterior end somewhat abruptly rounded. Car-
dinal margin nearly straight. Anterior end short, abruptly rounded at the
extremity ; indistinctly limited by a broad flattening of the valves extending
from the umbo to the base of the shell, about one-third the length from the
anterior end.

Valves very convex, gibbous on the middle and umbonal regions, somewhat
abruptly declining toward the anterior and posterior extremities; depth less
than one-half the length of the shell.

Hinge-line straight, slightly oblique, a little less than half the length of
the shell.

Beaks sub-anterior, small, closely appressed. Umbonal region gibbous to
about the posterior third, thence regularly declining to the margin.

Test of moderate thickness, concentrically striated.

Anterior muscular impression strong, with an accessory muscular pit. Pal-
lial line not deeply impressed, following the general course of the basal
margin, recurving at the posterior extremity, and terminating in a broad
posterior muscular impression. The space between the pallial line and um-
bonal region is marked by pitted vascular lines.

One of the specimens described has a length of 57 mm., height 32 mm.,
and depth of both valves 25 mm. Another specimen measures 52 mm.
in length and 30 mm. in height.

The general form of the shell is similar to M. subalata, but it has not the
distinct umbonal ridge, nor alate post-cardinal slope.

Formations and localities. In the cherty-layers of the Hamilton group, in
Clarke county, Ind. ; and in the Corniferous limestone of Canada West.

LAMELLIBRANCHIATA. 287

MODIOMORPHA SDBANGULATA, n. Sp.
PLATE XXXV, FIGS. 10, 11.

Shell of medium size, elongate sub-ovate, wider behind ; length more than
twice the height ; basal margin slightly arcuate, abruptly rounding at the
extremities; posterior margin acutely rounded below and obliquely sub-
truncate to the cardinal line ; cardinal margin nearly straight. Anterior
end rapidly declining from the beak and abruptly rounded below.

Valves moderately convex in the posterior part, and gibbous and sub-
angular in the umbonal region. There is a broad depression or sinus which
extends from just posterior to the beak to the basal margin near the middle
of the length of the shell.

Hinge-line slightly oblique, extending about half the length of the shell.

Beaks almost anterior, prominent, small, angular, incurved and elevated
above the hinge-line. Umbonal region gibbous, with a prominent ridge
extending from the beaks to the post-basal extremity, angular in its upper
portion, becoming more subdued toward the posterior end.

Test thick, marked by fine concentric striaa, which are sometimes fascicu-
late, making stronger ridges on the surface. Anterior end marked by a
strong, muscular impression just below the beak, close to the anterior margin.

A large individual of this species has a length of 55 mm., and a height of
26 mm. A smaller specimen has a length of 39 mm., and a height of 19 mm.

This species bears some resemblance to M. subalata, but differs in its much
stronger and more angular umbonal ridge, which reaches to the post-basal
extremity, the basal margin is more arcuate, the cardinal and basal margins
are more nearly parallel, and the anterior end is shorter.

Formation and locality. In the Chemung group, Mansfield, Tioga county. Pa.

MODIOMOEPHA RIGIDA.
PLATE XLI, FIGS. 11-16.

Modiomorpha rigida. Hall. Pal. N. Y., voL v, pt. 1. Plates and Explanations : PI. 41, figs. 10, 11, 14-16

(figs. 10, 11 in error). 1883.

Shell of medium size or smaller, sub-rhomboid-ovate; length nearly twice
the height; basal margin regularly and gently curving from the anterior

288 PALEONTOLOGY OF NEW YORK.

end to the post-basal extremity, abruptly recurving and extending thence in
a nearly direct line to the cardinal margin ; cardinal margin nearly straight.
Anterior end short, rounded, without any indication of limitation by a sinus
or otherwise.

Valves moderately convex, scarcely gibbous in the umbonal region.

Hinge-line straight, extending about half the length of the shell.

Beaks sub-anterior, small, closely appressed, rising but little above the
hinge-line. Umbonal region defined, sub-angular; the slope straight and
rigid, extending from the beaks to the post-basal extremity.

Test thin, marked by fine concentric stria), which are rarely fasciculate
and elevated into ridges. Interior unknown.

A medium-sized specimen has a length of 41 mm., and a height of 22 mm.
A smaller specimen measures 30 mm. in length and 17 mm. in height.

This species bears some resemblance to M. subalata, but is less alate on the
posterior slope ; the umbonal ridge is more direct, the post-basal extremity is
directed more downward, basal margin more regularly convex and without
evidence of a sinus.

The original reference of figs. 10 and 11 of plate xli to this species is
erroneous, those figures representing the Chemung variety of M. subalata.

Formation and localities. In the sandstones of the Chemung group, near
Angelica; and at Rock creek, Alleghany county, N. Y.

MODIOMORPHA RECURVA.
PLATE XLI, FIG. 17.
Hodiumorpha recurva. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 41, fig-. 17. 1883.

Shell of medium size, ovate-sub-cuneate ; length about twice the height ; basal
margin regularly curving to the anterior and posterior extremities. Posterior
end acute, recurving very abruptly toward the cardinal line. Cardinal margin
arcuate or nearly straight. Anterior end short, abruptly rounded, limited
posteriorly by a very shallow and undefined sinus (which is much too strongly
represented in the figure).

LAMELLIBRANCHIATA. 289

Valves moderately convex, except in the umbonal region, where they are
somewhat gibbous in the middle.

Hinge-line slightly arcuate, extending about half the length of the shell.

Beaks small, sub-anterior, incurved. Umbonal region prominent, gradually
declining to the post-cardinal slope.

Test thin, marked by fine concentric striae. Interior unknown.

The specimen described is somewhat distorted by pressure, and has a length
of 50 mm., and a height of 25 mm.

In its normal condition this species would resemble M. subalata and its vari-
ety, and may be compared with figs. 5, 10 and 11 of plate xli. The shell is
nearly all exfoliated, and the surface characters are thereby rendered obscure.

Formation and locality. In the arenaceous shales of the Chemung group, at
Belmont, Alleghany county, N. Y.

MODIOMOKPHA QUADRULA.

PLATE XLI, FIGS. 18-26.

Mod'unmtrpha quadrula. Hall. Prelim. Notice Lamellibraiichiata, 2, p. 77. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 41, figs. lS-26.

1883.

Shell small, quadrangular or rhoinboidal, varying in length and height from
nearly equal to almost twice as long as wide ; basal margin nearly straight
or slightly convex, curving abruptly into the anterior and posterior margins.
Posterior extremity sub-truncate, sometimes nearly at right angles to the
ba.sal line. Cardinal margin nearly straight or gently curved. Anterior
end declining abruptly from the beaks, narrow and abruptly rounded, not
limited by any defined sinus.

Valves moderately convex toward the basal and posterior margins, slightly
gibbous in the umbonal region.

Hinge-line scarcely oblique, extending two-thirds the length of the shell.

Beaks sub-anterior, small and closely appressed. Umbo rising above the
hinge-line and extending in a more or less defined obtusely angular ridge to
the post-basal extremity.

290 PALEONTOLOGY OF NEW YORK.

Test tliin, linely striated concentrically, with rarely any evidence of
fasciculation.

Anterior muscular impression large, situated just within the anterior
margin of the shell. Posterior scar superficial.

A specimen of medium size has a length of 20 mm., and a height of 14
mm. A more elongate form has a length of 20 mm., and a height of 12
mm. A large symmetrical specimen has a length of 30 mm., and a height
of 20 mm.

This is a small species of quadrangular form, but subject to much varia-
tion in its proportions, depending chiefly on the manner in which the lateral
compression has been directed, whether in the line of the longitudinal or
vertical axis of the shell ; those lying in one direction on the surface of the
shale being lengthened, and those at the right angles being considerably
widened and shortened.

This species differs from any of the foregoing in its small size, quadrangular
form, well-defined, straight, sub-angular umbonal ridge. The specimens, although
imbedded in a fine micaceous sandy shale, have had their surface characters
almost entirely destroyed by the deposition of sand, which has become incorpo-
rated with the shell, giving the surface a roughly granulose texture.

Formation and localities. In the micaceous sandy shales of the Chemung
group, at Belmont and Rocicville, in Alleghany county ; and in Cattaraugus
county, N. Y.

MODIOMORPHA NEGLECTA.

PLATE XM, FIG. 13.

Modlomorpha neglecta. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 41, figs. 12, 13. 1883.

(Fig'. 12 in eri-or.)

Shell small, ovate, wider behind ; length and height as 3 to 2 ; basal margin
straight in the middle, curving abruptly both at the anterior and posterior
extremities ; posterior margin regularly rounded, curving into the cardinal
margin, which is gently arcuate. Anterior end very short, declining abruptly
from the beaks, and regularly rounded below ; obscurely limited by a depres-
sion extending from the beaks to the basal margin.

LAMELLIBRANCHIATA. 291

Valves moderately convex in the posterior part, gibbous in the middle and
umbonal region.

Hinge-line short, oblique, about one-third the length of the shell.

Beaks anterior, prominent, small, distinct. Umbonal slope rounded, flat-
tened on the anterior side.

Test thin, marked by fine concentric striae. Interior unknown.

The specimen described has a length of 24 mm., and a height of 15 mm.

This form is distinguished from M. subalata, var. Chemungensis, by the absence
of defined umbonal ridge, and in the regularly rounded posterior extremity.

Formation and locality. In the Chemung group. Buck's quarry, near Elmira,
N. Y., associated with Orthis impressa, Atrypa hystrix, and Produdella Boydi.

MoDioMORPHA Tioga, n. sp.

PLATE XL, FIG. 18.

Modiomorphaf amygdalbia fWiifCHBLL, sp ), Hah. Prelim. Notice Lamellibranchiata, 2, p. 78. 1870.
In part " " " " Pal. N. Y., vol. v, pt. 1. Plates and Explanations :

PL 40, figs. 15-19. 1883.
Not SanguijiolUes amygdedimts, Winchell. Proc. Acad. Nat. Sci. Phila , p. 13. 1863.

Shell of medium size, sub-ovate, wider behind, sub-truncate at both extrem-
ities ; length one-half greater than the height ; basal margin slightly sinuate
in the middle, curving toward the extremities, and abruptly rounded into
the anterior and posterior margins. Posterior margin sub-truncate in the
upper portion. Anterior end declining abruptly from the beak and narrowly
rounded in front, limited by an obscure depression extending from the beak
to the basal margin.

Valves depressed-convex posteriorly and in the lower part, moderately
convex in the umbonal region.

Hinge-line imperfect in the specimen described.

Beaks situated a little less than about one-fourth the length of the shell
from the anterior end, small, closely appressed, rising very little above
the hinge.

Test thin, marked by fine concentric stria3, which, in some parts, have

292 PALAEONTOLOGY OF NEW YORK.

become lamellose. Anterior muscular impression shallow, situated just
within the anterior margin.

The specimen described has a lengtlx of 50 mm., and a height of 27 mm.

This species bears some resemblance to M. mytiloides, but the beak and
umbonal region are much less prominent, the anterior end is broader and the
bo<ly of the shell does not expand so rapidly toward the posterior end, mak-
ing the hinge-line less oblique.

Formation and locality. In the Chemung group, Mansfield, Tioga county. Pa.

MODIOMORPHA HYALEA.
PLATE XLI, FIGS. 28-30.

ilod'unmtrylia hyalea. Hall. Pi-elim. Notice Lainellibranchiata, 2, yi. 79. 1870.

Pal. N. Y., vol. V, pt. 1. Plates ami Explanations : PI. 41, figs. 28-30. 1883.
" J " " Pal. N. y., vol. V, pt. 1. Plates and Explanations : PI. 40, figs. 5-11 (errone-

ous i-eference). 1883.

Shell larger than the medium size, sub-elliptical; length nearly twice the
height ; basal margin nearly straight, or slightly arcuate near the middle,
recurving somewhat abruptly at the extremities. Posterior end abruptly
rounded, obliquely sub-truncate above, and curving into the cardinal line.
Cardinal margin nearly straight, and parallel to the basal margin of the
shell. Anterior end gently declining from the beaks, produced, and abruptly
rounded below ; not limited.

Valves moderately convex in the lower and posterior part, becoming more
convex and scarcely gibbous in the umbonal region.

Hinge-line straight, less than half the length of the shell.

Beaks broad, moderately prominent, curving over the hinge-line, situated
a little less than one-third the length from the anterior end. Umbonal
region prominent, scarcely gibbous ; the ridge prominent and rounded but
not gibbous.

Test thin, marked by closely arranged concentric striae, with occasional
stronger undulations which are more frequent on the umbonal region. Mus-
cular impressions unknown. Surface of the cast for some distance within

LAMELLIBRANCHIATA. 293

the pallial line marked by radiating vascular striae. (These striae, by mistake
in the figure, are continued over the umbonal region, where they do not exist.)
Three specimens have the following dimensions respectively: Length 51,
68 and 70 ram., height 26, 35 and 37 mm.

This species bears some resemblance in its general form to M. Tioga, but the
anterior end is more produced, the posterior extremity less regularly rounded,
and the surface markings are more rigid and less lamellose. The reference of
figs. 5-11, plate xl, to this species, in the Plates and Explanations, cited above,
arose from copying an erroneous record, without comparison ; the specimens do
not belong to the genus Modiomorpha.

Formation and locality. In the Waverly sandstone, Granville, Licking county,
Ohio.

GONIOPHORA, Phillips. 1848.

GONIOPHORA PERANGULATA.

PLATE XXXIV, FIGS. 1-6 ; AND PLATE XLII, FIGS. 1-2.

Sanffuinolites perangulatux. Hall. Prelim. Notice Lainellibi-amhiata, 2, p. 35. 1870.

" " S. A. MiLLKB. Cat. Ainer. Pal. Foss., p. 203. 1877.

Oimiophorapemnffiilata,.llA.i.L. S. A. Miller. Cat. Amer. Pal. Foss., p. 1!)2. 1877.

" •' " Pal. N. Y., vol. .5, pt. 1. Plates and Explanations : PI. 34, figs. 1-6. 1883.

Shell of medium size or smaller, trapezoidal ; length equal to twice the height;
basal margin regularly curving for the greater part of its extent with an
undefined sinuosity about the anterior third of the length, and a slight con-
striction near the posterior extremity ; posterior margin obliquely truncate
to the cardinal line, which is nearly straight. Anterior end short, abruptly
rounded below, sometimes obscurely limited by an undefined depression
extending from the beak to the base of the shell.

Valves convex, gibbous in the anterior portion, abruptly declining to the
basal and post-basal margins.

Hinge-line nearly straight, slightly a.scending from the anterior end,
equalling half the length of the shell.

Beaks anterior, small, acute, closely incurved. Umbo acutely angular;
umbonal ridge, with a slightly downward curve, extending to the post-basal
38

294 PALEONTOLOGY OF NEW YORK.

extremity. Between the umbonal ridge and the cardinal line the shell is
concave.

Test of moderate thickness. Surface marked by fine regular concentric
striae, which are sometimes thickened on the lower side of the shell. In a
well-preserved specimen the valves below the umbonal angles are marked by
fine radiating striae, which are more conspicuous posterior to the sinus. The
test on the umbonal ridge is elevated into a sharp crest.

Anterior muscular impression immediately below the beaks and close to
the anterior margin of the shell. Pallial line not deepl}^ impressed. Poste-
rior muscular scar strong, situated on the cardinal slope near the margin,
leaving a shallow groove in its advance from just behind the beaks. Liga-
mental groove very strong.

A specimen of medium size has a length of 46 mm. and a height of 24
mm. A smaller individual measures 43 mm. in length and 20 mm. in height.

In its anterior beaks and narrow posterior end this species resembles G. acuta,
but the cardinal line is much shorter than in that form, the basal margin is
less strongly sinuate and the umbonal ridge is not regularly arcuate. Compared
with G. truncata, the umbonal ridge is more distinctly curving, the cardinal
slope is concave, the radii are finer and more closely arranged.

Formation and locality. In the Schoharie grit, at Schoharie, N. Y.

GONIOPHORA ? ALATA, n. sp.
PLATK XXXIV, FIG. 7 ; AM> PLATE XI.II, FIG. 3.

Shell large, trapezoidal ; length less than twice the height ; basal margin
nearly straight ; posterior margin very broad, truncate ; anterior end short,
small, limited posteriorly by an undefined sinus.

Valves convex below, gibbous on approaching the umbo, and depressed
above the umbonal ridge, with an undefined furrow extending from a point
anterior to the beaks to the posterior margin.

Hinge-line straight, oblique, about one-third the length of the shell.

Beaks anterior, small and acute. Umbo prominent, angular ; the umbonal
ridge continuing to the post-basal extremity.

LAMELLIBRANCHIATA. 295

Test marked by strong concentric striae, which are acutely recurved upon
the umbonal angle.

In the specimen figured on plate xxxv the umbonal ridge, in the middle of
its length, has been accidentally flattened and the stronger stria? crossing
this flattened area are preserved, showing only a gentle curve in their
direction instead of sharply recurving over the angular portion of the ridge.

Interior essentially unknown.

A specimen of medium size has a length of 75 mm., and a height of 45
mm. A smaller individual has a length of 60 mm., and a height of 35 mm.
One large specimen has a length of 90 mm.

This species differs from all others here described in the extremely expanded
and alate cardinal slope.

Formation and locality. In the Schoharie grit, Schoharie, N. Y.

GONIOPHORA ACUTA.

PLATE XLIII, FIGS. 1-3.

Sanguinolitai acutuJt, Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 37. 1870.

" " S. A. MiLi-KB. Cat. Amer. Pal. Foss., p. 202. 1877.

Ocnilophora acuta. Hall. S. A. Millbr. Cat. Amer. Pal. Foss., p. 192. 1877.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 43, figs. 1-3. 1883.

Shell large, trapezoidal, very much elongated posteriorly; length more than
twice the height; basal margin straight on the posterior part with a sinus
anterior to the middle, beyond which it curves into the anterior margin;
posterior margin obliquely truncate ; cardinal margin nearly straight, or
slightly arcuate, extending nearly two-thirds the length of the shell.
Anterior end short, rounded below, limited by an oblique sinus extending
from the beak to the base, just anterior to the middle.

Valves convex below the umbonal ridge, depressed at the sinus, slightly
concave between the umbonal ridge and the cardinal line.

Beaks anterior, small, closely incurved. Umbonal ridge angular, prominent,
extending to the post-basal extremity.

Test moderately thick, marked by closely arranged sub-lamellose striae.

296 PALEONTOLOGY OF NEW YORK.

which are fiisciculose on the anterior portion of the shell, lladiiiting striae
are obscurely visible on botli the specimens figured. On the UTubonal ridge
the test is raised into a thin crest. Interior unknown.

The principal specimen described has a length of 80 mm., and a height of
about 28 mm.

This species resembles G. Hamillonensis, but differs in having the becaks nearer
to the anterior end, in its more elongate form, and in the radiating strias of the
surface-characters not observed in specimens referred to that species. As com-
pared with G. truncata, it is a more elongate shell with a proportionally longer
and less oblique hinge-line.

Formation and locality. In the soft shales of the Hamilton group, on the
shores of Canandaigua lake, N. Y.

GONIOPHORA HaMILTONENSIS.

PLATE XLIII, FIGS. 8-15, 17-21.

Sanguinoliles HamiWinensiii, Hall. Pi-elim. Notice Lamellibrancliiata, 2, p. 36. 1870.
Oim'wpliora Haviiltoieiisig, Hall. S. A. Miller. Cat. Amer. Pal. Foss., p. 192. 1877.

" " " Pal. N. Y., vol. V, pt, 1. Plates and Explanations: PI. 43, figa. 8-21.

1883.

Shell large, trapezoidal ; length more than twice the height ; basal margin
gently curving, sometimes nearly straight and slightly affected by the sinus.
Posterior margin obliquely truncate. Anterior margin concave below the
beak and abruptly rounded below. Cardinal line very slightly arcuate,
extending for two-thirds the length of the shell ; margins inflected, forming
a long, deep escutcheon.

Valves moderately convex below the umbonal ridge, and concave above it
to the cardinal line.

Beaks sub-anterior, small, clo.sely incurved, situated from one-fourth to
one-sixth the length of the shell from the anterior margin. Umbonal ridge
angular, strongly defined, arching over the beaks and extending in nearly a
direct line to the post-basal extremity. Umbonal region scarcely gibbous,
separated from the anterior end by a broad undefined sinus, which becomes
obsolete in some specimens, owing to compression.

LAMELLIBRANCHIATA. 297

Test of moderate thickness, marked by regular, prominent, lamellose striae.

Anterior muscular impression strong, sub-circular. Inter-pallial area pus-
tulose in the cast. Hinge thickened, carrying a single cardinal fold. Liga-
ment extending about half the length of the cardinal line, strong and prom-
inent, frequently preserved in specimens retaining the valves in conjunction.

The striated area, anterior to the cardinal pit (fig. 19, plate xliii), does not
appear to be an organic feature of the hinge, but is probably due to the
infolding and impression of the surface strias. The hinge does not preserve
striae posterior to the beak, as shown in the figure.

Three chariicteristic specimens measure respectively 87, 82 and 38 mm. in
length, and 39, 36 and 18 mm. in height. The smallest individual observed
has a length of 10.5 mm. and a height of about 5 mm.

This species differs from G. rugosa in having the umbonal ridge more direct,
more prominent and strongly angular ; the anterior end is shorter and narrower,
the posterior extremity more distinctly truncate and the surface of the shell is
less rugose.

Formation and localities. In the shales of the Hamilton group, Fultonham
and Bear's gulf, Schoharie county, and throughout the eastern and central
portions of the State.

GONIOPHORA BUGOSA.

PLATE XLU, FIGS. 7,8a; and PLATE XLIII, FIGS. 4-7.

Cyprleardites rugosa, Conrad. Geol. Sui-v. N. Y., Ann. Rep., p. 53. 1841.
8anffuinolite» rugotus (Cohrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 37. 1870.
Qoniophora rugom, Conbad. S. A. Millkr. Cat. Amei'. Pal. Foss., p. 192. 1877.

.< •• " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 43, figs. 4-7.

1883.

Shell of medium or large size, sub-rhomboidal ; length less than twice the
height ; basal margin gently curved, flattened on approaching the anterior ;
posterior margin sub-truncate, gently curving from the post-basal extremity
to the cardinal line. Anterior end declining rapidly from the beaks and
abruptly rounded below. Cardinal line gently arcuate, slightly oblique,
extending for about two-thirds the length of the shell.

298 PALEONTOLOGY OF NEW YORK.

Valves moderately convex below the umbonal ridge, sometimes more con-
vex ; depressed convex or nearly flat above the umbonal slope.

Beaks sub-anterior, small, closely incurved. Umbo prominent. The
umbonal ridge is more or less strongly defined, extending in a slightly curv-
ing line to the post-basal extremity.

Test strong, marked by somewhat irregularly rugose or undulating lamel-
lose striae, which make an abrupt curvature or an angular return in crossing
the umbonal ridge. Interior unknown.

Three specimens have the following respective dimensions: Length 60, 51,
and 32 mm. ; height 35, 29 and 18 mm.

This species is distinguished by its short form, rounded posterior extremity,
and rugose surface characters.

Formation and localities. In the shales of the Hamilton group, shores of Canan-
daigua, Cayuga and Seneca lakes, and near Schoharie, N. Y.

GONIOPHORA TRUNCATA.
PLATE XLU, FIGS. 9, 10 ; AND PLATE XLIV, FIGS. 1-5.
Ooniophora truncata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 44, figs. 1-5. 1883.

Shell of medium size, trapezoidal ; length more than twice the height ; basal
margin rounded in the anterior part, slightly sinuate a little anterior to the
middle and nearly straight or slightly curving to the post-basal extremity ;
posterior margin obliquely sub-truncate, slightly curving. Cardinal line short,
straight. Anterior end short, rounded, limited by an oblique sinus extending
from the beak.

Valves convex below the umbonal ridge, gibbous in the umbonal region ;
the area above the umbonal ridge is flat or concave, or sometimes a little
convex.

Beaks anterior, acute and incurved ; umbo prominent, angular. Umbonal
ridge strongly defined, acutely angular, extending to the post-basal extremity.

Test of moderate thickness ; entire shell marked by fine, lamellose, con-
centric striae, and that portion of the surface between the xmibonal ridge and

LAMELLIBRANCHIATA. 299

the sinus is marked by strong, elevated, radiating strige, which dominate
the concentric striae. The test is raised into a crest along the umbonal
ridge, especially in the posterior half of its length.

Anterior muscular impression large and deep, situated close to the anterior
margin, truncated posteriorly by a strong ridge or clavicle. Pallial line
parallel to and near the basal margin, appearing as a shallow groove, recurv-
ing near the post-basal extremity and terminating in a broad, muscular
impression, the anterior margin of which is near the center of the length of
the shell.

A specimen of medium size has a length of 54 mm., and a height of 23
mm. A somewhat smaller individual measures 50 mm. in length and 20
mm. in height.

This species is very closely allied to G. perangulaia of the Schoharie grit, and
it is possible that they are identical. In the specimen fig. 3 of plate xl, the
hinge-line is shorter than in specimens of G. perangulata, but the compara-
tive length of the hinge-line appears to be variable in the two species. Other
differences are pointed out under the description of that species.

Formation and localities. In the shales of the Hamilton group, on the shores
of Cayuga and Skaneateles lakes, at Delphi and Pratt's falls, Onondaga
county, N. Y.

GONIOPHORA GlAUCUS.

PLATE XLm, FIG. 16; AND PLATE XLIV, FIGS. 10-17.

SanguinolUes Olaueus, Hall. Prelim. Notice Lamellibranchiata, 2, p. 38. 1870.
Goniophora glabra, Hall (in eiTor). S. A. Miller. Cat. Amer. Pal. Foss., p. 192. 1877.

.• " " Pal. N. y., vol. V, pt. 1. Plates and Explanations : PI. 44, figs. 9-17. 1883.

Shell large, trapezoidal ; length once and a half greater than the height ; basal
margin gently curved, sometimes scarcely sinuate anterior to the middle ;
posterior margin obliquely truncate ; cardinal line nearly straight or slightly
oblique ; anterior end declining from the beaks and abruptly rounded below.
Valves moderately convex below, sometimes becoming gibbous in the
umbonal region.

300 PALEONTOLOGY OF NEW YORK.

Beaks sub-anterior, small and closely appressed ; umbo prominent ; umbo-
nal ridge more or less strongly defined and distinctly angular, extending to
the post-basal extremity.

Test of moderate thickness, marked by regular concentric thread-like
striae, which are abruptly recurved on the umbonal ridge ; anterior muscu-
lar impression deep and strong. The pallial line extends parallel to the
ba-sal margin, and abruptly recurves over the umbonal ridge, terminating in
a large shallow posterior muscular scar upon the cardinal slope. The hinge
is furnished with a strong triangular fold beneath the beak of the left valve,
and a corresponding depression in the right valve.

Three specimens measure respectively 90, 61 and 49 mm. in length, and
49, 39 and 28 mm. in height.

This species closely resembles G. Hamiltmensis, but differs principally in its
proportionally shorter form, more convex basal margin and more direct umbo-
nal ridge.

Formation and localities. In the Hamilton group, Fultonham and Be.ar's
gulf, Schoharie county; Kelloggsville, Cayuga county, and on the shore of
Cayuga lake, N. Y.

GoNioPHORA Ida.

PLATE XLU, FIG. 13; AND PLATE LXV, FIG. 20.

Sanguinolites Ida, Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 43. 1870

Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 6."), fig. 20. 1883.

(( «(

Shell of medium size, elongate sub-elliptical ; length about two and one-half
times the height ; basal margin regularly curved ; posterior margin very
obliquely truncate. Cardinal line straight, less than half the length of the
shell. Anterior end gently declining from the beak, narrow, and abruptly
rounded at the extremity.

Valves regularly convex; cardinal slope depressed, and abruptly concave
just above the umbonal ridge.

Beaks at about the anterior third, small, appressed, slightly projecting

LAMELLIBRANCHIATA. 301

above the hinge-line. Umbo moderately prominent. Umbonal ridge dis-
tinctly angular, extending from the beak to the post-basal margin.

Test thin, marked by fine concentric striae, which are more or less fascicu-
late on the body of the shell, and very regular and uniform on the post-
cardinal slope. Interior unknown.

The right valve in the specimen figured on plate Ixv, fig. 20, has a length
of 49 mm. and a height of 19 mm. A larger and better-preserved specimen
has a length of 59 mm. and a height of 22 mm. Another specimen referred
to this species has a length of 45 mm. and a height of 18 mm.

This species differs from the others of the Hamilton group in its narrow ellip-
tical form, the regular curving basal margin, and narrow anterior end. The
hinge-line is comparatively shorter than in any of the species of the Hamilton
group except G. truncata.

Formation and localities. In the upper portion of the Hamilton group, at
Geneseo, Livingston county ; at Bellona, Yates county ; on the shore of Cayuga
lake, and from a boulder of Hamilton shale at Sexton's, near the head of Seneca
lake, N. Y.

GONIOPHORA CARINATA.

PLATE XLU, FIG. 11 ; and PLATE XLIV, FIGS. 6-8.

Cypricarditex cariiuUa, Co.vbad. Geol. Sui-v. N. Y., Ann. Rep., p. 53, plate, Hg. 21. 1841.
Sanfftdnolttes carinatux (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 43. 1870.
Compare Cypi-ieardites Chemungensis, Vancxem. Geol. Surv. N. Y., Rep. Third Dist., p. 181, 2 ; p. 179.

1842.

Shell of medium size or larger, trapezoidal; length more than twice the height;
basal margin sinuate anterior to the middle, curving gently to the post-basal
extremity and more abruptly to the anterior; posterior margin obliquely
truncate. Cardinal line nearly straight and parallel with the basal margin,
equal to one-half the length of the shell. Anterior end sloping gently from
the beak and abruptly rounded below, limited by a broad undefined sinus
which constricts the basal margin.

Valves moderately convex below the umbonal ridge, slightly concave on
the cardinal slope.
39

302 PALAEONTOLOGY OF NEW YORK.

Beaks situated less than one-third the length of the shell from the anterior
end, closely incurved. Umbo prominent. Umbonal slope distinctly carinated
and terminating at the basal extremity.

Test of moderate thickness, marked by fine undulating concentric strite,
which are aggregated into folds upon the lower and anterior part of the shell.
On the cardinal slope these undulations are less prominent. Interior unknown.

Four specimens have the following dimensions respectively : Length 70,
63, 35 and IG mm. ; height 28, 26, 16 and 7 mm.

This species is comparatively longer than G. Hamiltonensis and G. rugosa, and
the concentric striae are finer and strongly fasciculate, while the anterior end
is much longer. Compared with G. Chemungensis, the beaks are more distant
from the anterior end, the umbonal ridge is slightly curved, while in that
species it is very rigid ; the posterior extremity is wider.

Formation and localities. In the shales of the Hamilton group, associated with
Paracyclas lirata, Chonetes scitula, Spirifera mucronata and Hyolithes aclis, at Cop-
ley's quarry, Oneonta, and near Mount Upton, N. Y.

GONIOPHOKA TRIGON.\, n. Sp.

PLATE XUI, FIG. li ; AND i'LATE XLIV, FIG. 9.

Ooniophora gUibra, Hall (error for G. OUmcus). Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI.

44, fig. 9. 1883.

Shell large, trapezoidal; body sub-trigonal; length twice the height; basal
margin sinuate anterior to the middle, curving gently toward the post-basal
extremity and more rapidly to the anterior ; posterior margin obliquely
truncate ; cardinal line short, essentially straight ; anterior end large, slop-
ing somewhat abruptly from the umbo and narrowly rounded below, limited
posteriorly by a broad undefined sirms. Shell convex below, gibbous above ;
cardinal slope slightly concave, descending abruptly from the umbonal ridge
and gently rising toward the cardinal line.

Beaks at about the anterior third ; umbo very prominent ; umbonal ridge

LAMELLIBRANCHIATA. 303

distinctly angular, descending in nearly a direct line to the post-basal
extremity.

Test of moderate thickness ; the cast is marked by fine concentric strife,
which are strongly fasciculate on the anterior portion of the shell, and regu-
lar and uniform in strength on the post-cardinal slope. Interior unknown.

The specimen described has a length of 72 mm. and a height of 35 mm.

This species, compared with any other, has a much greater elevation of the
umbo above the base of the shell, a larger anterior end and a more rapid
declension to the post-basal extremity. The figure of this species given on
plate xliv does not correctly represent the specimen.

Formation and locality. In the Chemung group, near Franklin, Delaware
county, N. Y.

GONIOPHORA ChEMUNGENSIS.

I'LATK XLIV, FIGS. 18, 20, 22.

Cffpricarditen Chemungensin, Vaxixkm. Geol. Surv. N. Y., Reji. Thii-il Dist., p. 181, tig. 2; p. 170. 1842.

Saiiffuiiwlitet Chemii.ii(jfmis, " S. A. Miller. Cat. Amer. Pal. Foss., p. 202. 1877.

Chmkrphora Chemungetisis (Vani-xkm), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 44,

figs. 18-22. 1883.
Cypricarditeg carinifera, Conrad. Jour. Acail. Nat. Sci., Phila., vol. viii, p. 245, pi. 13, fig. 14. 1842.

Shell large, trapezoidal ; length two and one-half times the height ; basal
margin very gently curving, nearly straight, or slightly sinuate anterior to
the middle ; posterior extremity obliquely truncated. Cardinal line straight,
parallel to the base, extending for nearly two-thirds the length of the shell.
Anterior end sloping rapidly from the beak and abruptly rounded below,
limited by a very oblique, narrow, undefined sinus, which reaches the base
more than one-third of the length from the anterior end.

Valves moderately convex on the lower side, becoming gibbous in the
umbonal region. Post-cardinal slope fiat or slightly concave.

Beaks sub-anterior, small and closely incurved, situated less than one-
fourth the length of the shell from the anterior extremity. Umbo prom-
inent. Umbonal ridge distinctly angular, extending in a direct line or with
a gentle curvature to the post-basal extremity.

304 PALjEONTOLOGY OF NEW YORK.

Surface marked by fine, concentric striae, which become fascicled and form
strong undulations on the anterior end of the shell. The striae are acutely
recurved on passing the umbonal ridge. Interior unknown.

Three specimens measure respectively, 75, 63 and 55 mm. in length, and
28, 25 and 22 mm. in height.

Compared with G. carinata the anterior end is proportionally shorter, the
sinus more oblique, the posterior end narrower, and the recurving of the striae
over the umbonal ridge is much more abrupt.

The specimen fig. 18 of plate xliv is the typical specimen figured by Vanuxem
loc. cit.

Formation and localities. In the Chemung group, near Owego, Binghamton
and Chemung Narrows, N. Y.

GONIOPHOKA SUBBECTA, n. sp.

PLATE XLU, FIGS. U, 15 ; AND PLATE XLIV, FIGS. 19, 21.

Owiiophom ChemungensU (Vandxkm), Halt, (in error). Pal. N. Y., vol. v, pt. 1. Plates and Explanations :

PI. 44, figs. 19, 21. 1883.

Shell large, trapezoidal; length more than twice the height; basal margin
gently curving, with a slight sinuosity anterior to the middle; posterior
margin obliquely truncate, very gently curving ; cardinal line straight, par-
allel to the base, having a length of less than two-thirds the entire length of
the shell ; anterior end gradually declining from the beak, abruptly rounded
below, and limited by an obscure sinus, which reaches the base at about the
anterior third.

Valves moderately convex below the umbonal ridge, scarcely gibbous in
the umbonal region ; cardinal slope broad and essentially flat.

Beaks sub-anterior, small and closely incurved. Umbo prominent ; umbo-
nal ridge angular, slightly curving downward and extending to the post-
basal extremity.

Test concentrically striated. The striae above the ridge are simple and
continuous, and below they are aggregated into fascicles. Interior unknown.

LAMELLIBRANCHIATA. 305

Three specimens measure respectively 82, 57 and 50 mm. in length, and
32, 21 and 21 mm. in height.

This species more nearly resembles G. carinatus, but the anterior end is pro-
portionally shorter, the sinus not so strongly marked, the post-cardinal slope
broader, and the striae not so abruptly recurved in passing the umbonal ridge.
From G. Chemungmsis it differs in its wider posterior end, the gentle downward
curving of the umbonal ridge, the wider cardinal slope and the less abrupt
recurving of the striae in passing the umbonal ridge. It is easily distinguished
from the last-mentioned species by these characteristics.

Formation and localities. In the Chemung group, Franklin, Delaware county;
and at summit of hill, east of Charlottesville, and at Jefferson, Schoharie
county, N. Y.

GONIOPHORA MINOR, n. Sp.
PLATE XLII, FIGS. 4-6.

Shell small, trapezoidal ; length about one-third greater than the height ; basal
margin gently convex on the anterior half, becoming straight or slightly
arcuate behind ; posterior margin obliquely truncate. Cardinal line straight,
about two-thirds the length of the shell. Anterior end narrowly rounded
below the lunule.

Valves convex below, becoming gibbous in the umbonal region.

Beaks sub-anterior, closely incurved. Umbo prominent, angular. Umbo-
nal ridge sharply angular, continued to the post-basal extremity, and carry-
ing a conspicuous crest. Post-cardinal area slightly convex.

Surface marked by strong, regular, concentric strias, which are less con-
spicuous on the post-cardinal area. One specimen shows indications of fine,
radiating striae on the posterior half of the valve.

Anterior muscular impression strong, situated just within the anterior

extremity.

Two characteristic specimens have respective lengths of 12 and 11 mm.,
and heights of 8 and 7 mm. A comparatively shorter form has a length of
9 mm., and a height of 7 mm.

806 PALEONTOLOGY OF NEW YORK.

This species is much smaller than any form here described. It somewhat
resembles G. truncata, but differs in its greater proportional height, the area
between the carina and hinge-line is more convex; the concentric striae are
much stronger and the indications of radiating striae are quite obscure.

Formation and locality. At the base of the Clieniung (Ithaca group) at Ithaca,
N. Y.

LAMELLIBRANCHIATA. 307

MICRODON, Conrad. 1842.
CYPRICARDELLA, Hall. 1858.

EODON, Hall. 1877.
MICRODONELLA, (Ehleet. 1881.

MiCRODON (CyPRICARDELLA) MAJOR, n. Sp.
PLATE XLII, FIG. 21.

Shell large, rhomboid-ovate ; length one-third greater than the height ; basal
margin regularly curving ; more abruptly recurving at the anterior end and
less abruptly at the posterior ; posterior margin sub-truncate, slightly curv-
ing ; cardinal margin oblique, nearly straight. Anterior end broadly rounded.

Valves moderately convex, not gibbous.

Beaks, at about the anterior fourth of the shell, appressed. Umbonal
region distinctly convex, declining in an undefined ridge to the post-basal
cangle.

Test comparatively thick, marked by strong, regularly rounded concentric
striae, which are abruptly recurved on the post-umbonal slope. Interior
unknown.

The specimen described has a length of 73 mm., and a height of 50 mm.

As compared with M. bellastriata it is a much larger form, with broader ante-
rior end, more extended at the post-basal extremity and the striae more abruptly
recurving over the umbonal slope. In the extension of the post-basal extrem-
ity it resembles M. complanata, but in other respects it is quite different.

Formation and locality. In the Corniferous limestone of the Upper Helderberg
group, at Delaware, 0.

308 PALEONTOLOGY OF NEW YORK.

MiCROUON (Cypricardella) bellistriatus.

PLATS XLir, FIGS. 17-20; PLATE LXXIH, FIGS. 7-22; and PLATE LXXIV, FIGS. 8-10.

Microdou bellaatriata, CoKRiv. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 247, pi. 13, fig. 12. 1842.
" " " Hall. Geol. Sui-v. N. Y., Rep. Fourth Dist., p. 196, fig. 2. 1843.

" " " R00BR.S. Geol. Pennsylvania, p. 827. 1868.

•« " " Hall. Twenty-third Kept. N. Y. State Cab. Nat. Hist., pi. 14, fig. 8. 1873.

" " " " PreUni. Notice Laniellibranchiata, 2, p. 31. 1870.

Eodon bellistriatus (Conrad), S. A. Miller. Cat. Amer. Pal. Foss., p. 244. 1877.
Microdonella Mllitnata (Conrad), CEhlert. Mem. Geol. Soc., France, Third Ser., torn, ii, p. 27, pi. 4, figs.

4a, 4b. 1881.
Microdoa (MicrodoyuUa) (Eodon) bellistrkUus (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and

Explanations : PI. 73, figs. 7-22 ; pi.
74, figs. 4-10. 1883.
Compai-e Sanguinolaria Iwnelhsa, Goldkcss. Petrefacta, vol. ii, p. 279, pi. 59, fig. 12. 1834-1840.

Shell of medium size or larger ; form sub-rhomboidal to sub-elliptical ; pro-
portions of length and height extremely variable, varying from a length of
twice the height, to a length of less than one-third greater than the height ;
basal margin regularly curving anteriorly, often nearly straight in the poste-
rior half ; posterior margin almost vertically sub-truncate, sometimes gently
curving. Cardinal line nearly straight, sometimes slightly declining poste-
riorly, often arcuate. Anterior end narrowed, prolonged below and abruptly
I'ounded at the extremity ; constricted above by a distinct lunule.

Valves depressed-convex, becoming moderately convex in the umbonal
region.

Beaks usually at about the anterior third, but often nearer the anterior
extremity, small, closely appressed, scarcely rising above the hinge-liue.
Umbo sometimes moderately convex. Umbonal slope continued as a low
undefined ridge to the post-basiil angle.

Test of moderate thickness, marked by strong, even, angular striae, which
continue of nearly uniform character over the entire shell, Jind are subdued
in specimens from the softer shales.

Anterior mu.scular impression strong; posterior one superficial. Left
valve marked by a strong oblique fold or tooth, with a corresponding cavity
in the right valve. Posterior to this cavity are one or more obscure folds.
No lateral teeth proper have been observed.

LAMELLIBRANCHIATA. 309

Six characteristic specimens have the following dimensions, respectively :
Length 46, 37, 35, 37, 28 and 38 mm.; height 27, 22.5, 25, 28, 21 and 31 mm.

This species differs from M. gregarius in its broader cardinal slope, less
oblique posterior margin, larger size and stronger surface striae. M. complanatus
is a larger and more elongate form, the posterior and anterior extremities more
regularly curved, the striae irregular and fascicled, the beaks more elevated and
the posterior margin more obliquely truncate.

Formation and localities. In the shales of the Hamilton group throughout the
range of this formation in the State of New York, but more abundant in the
eastern and central portions ; also from the same horizon, near Cumberland,
Md. ; and in the Chemung group, near Elmira and Ithaca, N. Y. ; and from
Susquehanna and Tioga counties. Pa.

MiCRODON (CyPRICARDELLA) GREGARIUS.

PLATE LXXIU, FIGS. 1-6 ; AND PLATE LXXIV, FIGS. 1-4.

MicTodon gregaria, Hall. Prelim. Notice Lamellibranchiata, 2, p. 32. 1870.

Mlerodnn (Microdonella) (Eudon) greganus. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI.

73, figs. 1-6. 1883.

Shell small, rhomboid-ovate; length less than one-third greater than the
height; basal margin regularly curving, sometimes nearly straight toward
the post-basal angle ; posterior margin obliquely sub-truncate, slightly curv-
ing; cardinal margin gently arcuate or nearly straight. Anterior end
declining abruptly from the beaks, with the extremity narrow and abruptly

rounded.

Valves depressed-convex, more convex at the umbo and on the umbonal

ridge.

Beaks situated at less than the anterior third of the length, small, low,
closely appressed, scarcely rising above the hinge-line. Umbonal ridge dis-
tinct, but not strongly defined, continuing to the post-basal angle.

Test thin, marked by fine, concentric striae, which are somewhat fasciculate
on the anterior portion of the shell.
40

310 PALEONTOLOGY OF NEW YORK.

Anterior muscular impression not strongly developed, placed just within
the anterior border of the shell.

Three specimens measure respectively 29, 27 and 22 mm. in length, and
22, 20 and 16 mm. in height.

This shell, in its general form, resembles M. bellistriatus, but the posterior
end is always more curving, and the margin more distinctly directed forward,
the post-cardinal slope narrower, and the striae are always finer and less regu-
lar. As compared with M. tenuistriatus it is usually a little larger proportion-
ally ; the hinge-line is shorter, the beak situated a little nearer the anterior
end and more obtuse.

Formation and localities. In the flaggy layers of the upper part of the Ham-
ilton group, at Jefferson, Schoharie county ; in shaly sandstones of the same
group, between Jefferson and Summit ; and in the lower part of the Chemung
group, at Cortland, Ithaca, Elmira and Portville, N. Y. ; and Tioga county. Pa.

MiCRODON (Cypricardella) tenuistriatus.

PLATE XLII, FIG. 16 ; l-LATE LXXIII, FIGS. 23-30 ; AND PLATE LXXIV, FIGS. 20, 21.

MicrodoH tenuiitriata. Hall. Prelim. Notice Lamellibranchiata, 2, j). 32. 1870.

Microdon (Mierodoivella) (Hodon) tenimtriatus, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. 73, figs. 23-27, 29, 30 ; j)!. 74, figs. 20, 21. 1883.

Shell large, quadrangularly sub-ovate ; length one-fourth greater than the
height ; basal margin regularly curving ; posterior margin sub-truncate, from
oblique to nearly vertical and gently curving. Cardinal line gently arcuate.
Anterior end rapidly declining from the beak and abruptly rounded below.

Valves depressed-convex below, rising into moderate convexity in the
umbonal region.

Beaks at about the anterior third, small and appressed, rising a little
above the hinge-line. Umbonal slope scarcely defined, extending in a slightly
arching direction to the post-basal extremity.

Test thin, marked by fine, unequal, concentric striae, which are at intervals
raised into lamelliform undulations. In some specimens the striae upon the
umbonal region are very uniform, thread-like and equal throughout.

LAMELLIBRANCHIATA. 311

Anterior muscular impression large and strong, situated just within the
anterior margin of the shell.

Three specimens measure respectively 46, 42 and 38 mm. in length, and
35, 31 and 29 mm. in height.

As compared with M. bellisiriahis it is much larger than the prevailing forms
of that shell, the basal line is more strongly curved, the post-umbonal slope
not so well-defined, the posterior extremity usually more curved, and never
angular as in that species ; the striae, except upon the umbo, are never so well-
defined. In its extremely young state, its surface characters resemble M. bel-
listriatus, and the form is not essentially different, but it is less angular, and the
umbonal slope less distinctly defined.

Formation and localities. In the compact arenaceous shales of the Hamilton
group, at Hamilton, Madison county, and at Summit and Fultonham, Schoharie
county ; it also occurs in the softer calcareous shales of the group on the
shores of Canandaigua lake, Ontario county, N. Y.

MiCRODON (Cypricardella) complanatus.

PLATE XLII, FIG. 22 ; and PLATE LXXIV, FIGS. 14-19.

Mlerodon t eompianatus. Hall. Prelim. Notice Lamellibranchiata, 2, p. 33. 1870.

Mierodim (Mlerodonella) (Eodun) complanatus, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. 74, figs. 14-19. 1883.

Shell large, sub-rhomboid-ovate ; length more than one-third greater than the
height ; basal margin regularly curved, sometimes straighter on the posterior
portion ; posterior margin obliquely truncate, slightly rounded ; cardinal
margin usually slightly arcuate, often appearing nearly straight. Anterior
end declining somewhat rapidly from the beaks, and abruptly rounded below.
Valves moderately convex below, somewhat gibbous in the umbonal region
and flattened above. The shells are sometimes so compressed that the
umbonal ridge is obsolescent.

Beaks at about the anterior fifth, small and not prominent. Umbo prom-
inent. Umbonal ridge usually conspicuous, rounded, extending to the post-
basal extremity.

312 PALEONTOLOGY OF NEW YORK.

Test thin, marked by fine, concentric striaB, which are fasciculate on the
anterior portion of the shell.

Anterior muscular scar large and not deep, a little anterior to. the beak,
with a smaller accessory muscular scar above. Pallial line parallel to the
basal margin, terminating in a large, shallow, posterior muscular impression.
Interpallial area sometimes pitted. Hinge with an oblique fold in the right
valve and a strong ligamental area.

A large specimen has a length of 72 mm., and a height of 42 mm. Three
medium-sized specimens measure respectively 57, 51 and 50 mm. in length,
and 34, 30 and 31 mm. in height.

This species is more elongate than M. ienuistriatus, and is also more convex,
with a more prominent umbonal ridge and elevated beaks. Its absolute iden-
tity with the genus Microdon has not been fully determined from the internal
characters, but its external form and general features ally it more nearly with
that type than with any other known genus.

Formation and localities. In the Hamilton group, at Jefferson, and between
Jefferson and Summit, Schoharie county; and below Norwich, Chenango
county, N. Y.

Microdon reservatus.

PLATE LXXIV, FIGS. 11-13.

Microdon reservatus. Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 33. 1S70.

" " *' Pal. N. y., vol. V, i)t. 1. Plates and Explanations: PI. 74, figs. 11-13. 18S3.

Shell above the medium size, rhomboid-ovate ; length one-fourth greater than
the height ; basal margin regularly convex ; posterior margin almost verti-
cally truncate. Cardinal line short, arcuate. Anterior end declining some-
what abruptly from the beaks and rounded below.

Valves depressed-convex in the lower part, moderately and regularly con-
vex above.

Beaks at about the anterior third, small, rising little above the hinge-line.
Umbonal ridge scarcely defined, extending to the post-basal extremity in a
slightly arching direction.

LAMELLIBRANCHIATA. 313

Test thin, marked by moderately strong concentric striae, which are raised
into varices or concentric undulations at irregular intervals.

Anterior muscular impression just within the anterior border, above the
longitudinal center of the shell.

The three specimens figured measure respectively 45, 37 and 34 mm. in
length, and 35, 28 and 27 mm. in height.

This species differs from any other described, in the stronger curvature of the
basal margin, bringing the termination of the umbonal ridge higher, and giving
a proportionally narrower cardinal slope and posterior end ; in other respects,
it is very similar to the M. tenuistriatus of the Hamilton group.

Formation and locality. In the Waverly sandstones of Licking county, 0.

NUCULA, Lamarck. 1799.

NUCULA NIOTICA.

PLATE XI.V, FIGS. 1,2.

Nucala niotica. Hall and Whitfield. Twenty-fourth Ann. Rep. N. Y. State Mus. Nat. Hist., p. 190. 1872.
„ .< .. " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 45,

figs. 1, 2. 1883.

Shell small, obtusely sub-cuneiform ; length a little greater than the height ;
basal margin regularly curving, rounded posteriorly ; cardinal margin very
oblique ; anterior margin vertically truncate.

Valves very gibbous.

Beaks anterior, incurved. Umbo prominent. Umbonal slope very gibbous.

Test thick in the upper part, marked by fine, even, concentric strise, which
are aggregated into fascicles of growth.

The internal casts show strong anterior and posterior muscular impres-
sions, and three distinct umbonal muscles ; there are seven or more pos-
terior, and five anterior teeth in a specimen of medium size.

An internal mould has a length of 17 mm., and a height of 13 mm. A
specimen preserving the test has a length of 18 mm., and a height of 16 mm.

314 PALEONTOLOGY OF NEW YORK.

Formation and locality. In the upper beds of limestone, at the Falls of the
Ohio, of the age of the Hamilton group, near Louisville, Ky.

NucuLA Neda.

PLATE XLV, FIGS. S, 4.

Nucuia Neda, Hall and Whitkikld. Twenty-fourth Ann. Rep. N. Y. State Mus. Nat. Hist,, p. 191. 1872.
" " " " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 45,

figs. 3, 4. 1883.

Shell of medium size, rhomboid-ovate, cuneate, length about one-fifth greater
than the height ; basal margin broadly rounded ; cardinal margin sloping to
the anterior and posterior extremities, which are abruptly rounded.

Valves gibbous, with the umbones ventricose.

Beaks a little more than one-third the length of the shell from the anterior
end, prominent and incurved.

The surface has been marked by fine, concentric striae.

The cast shows strong anterior and posterior muscular impressions, with
three or four umbonal muscular scars and a narrow protractor scar just within
the cardinal line, and anterior to the posterior muscular area, as usual in the
genus.

The number of teeth cannot be determined, but there are as many as six
or eight on the posterior side, with a distinct ligamental cavity, in the cast,
beneath the beak.

The specimen described has a length of 21 mm., and a height of 17 mm.

This species is of the size and form of Nucula levata, of the lower Silurian
rocks, and differs but little from Nucula bellistriata, of Conrad.

Formation and locality. In the hydraulic limestone of the age of the Hamil-
ton group, near Louisville, Ky.

LAMELLIBRANCHIATA. 315

NucuLA Randalli.

PLATE XLV, FIGS. 6-10. 16, 23, 26, 27 ; and PLATE XCIll, FIGS. 1-3.

Nucula Randalli, Hall. Prelim. Notice Lamellibrauchiata, 2, p. 3. 1870.

In part Nttcula Handalli, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 45, figs. 5-16.

18S3.
CiicuUea opitna. Hall. Geol. Rep. Fourth Dist. N. Y., p. 197, No. 78, fig. 3, p. 196. 1843.

Shell robust, of mediuin size ; short ovate ; length about one-third greater than
the height ; basal margin regularly rounded, very abruptly curving at the
anterior and posterior extremities ; dorsal margin sloping gradually down-
ward ; anterior margin abruptly declining from the beaks.

Valves ventricose ; depth of the conjoined valves equal to the height of
the shell.

Beaks at about the anterior third closely incurved. Umbo very promi-
nent. Post-umbonal slope abruptly rounded and extending nearly to the
post-cardinal extremity.

Test comparatively thick, marked by fine, regular, angular thread-like
striae, which are interrupted by varices of growth, and are usually fasciculate
on the anterior portion of the shell ; also by extremely fine radiating striae,
which are usually more conspicuous below the middle of the valve, and which
are often obscure or entirely obsolete.

Muscular impressions strongly marked. Teeth coarse.

Four characteristic specimens measure respectively 25, 23, 22 and 21 mm.
in length; 17, 16, 15 and 15.5 mm. in height; and 18, 16.5, 14 and 12.5
mm. in depth.

This species presents the general form of N. lirata, but the beaks are broader
and more closely incurved, and the surface is not marked by the strong undu-
lations which characterize that species.*

• In the Preliminary Notice of the Lamellibranchiata, 2, page 3, the Cucullea ophna, of the Report of the
Fourth Geologic-al District, 1843, was eri-oneously referred to Nucula lirata of Conkad. I have recently
examined the original specimen of the Cueidlea opium, and there can be no hesitation regarding its identity
with N. Randalli, of 1870 ; but since the latter has gone into the literature of the science, I have preferred
to leave the name as it stands at the head of this description.

316 PALAEONTOLOGY OF NEW YORK.

In nearly all the well-preserved specimens of this species the beaks have
been eroded during life, as shown in figures on plate xciii.

Formation and localities. In the shales of the Hamilton group, at Pratt's falls
and Delphi, Onondaga county ; in Schoharie, Otsego and Madison counties,
and on the shores of Seneca lake.

NUCULA LIRATA.

PLATE XI-V, FIGS. », 11, 15, 17-!H, 24, 28; AND PLATE XCUI, FIG. 6.

Nucvlites lirata, Conrad. Jour. Acad. Nat. Sci. Phila., vol. viii, p. 250, pi. 15, fig. 7. 1842.

Nueula luieatat (Phillips), Hall. Geol. Surv. N. Y., Rep Fourth Dist., p. 197, No. 78, fig. 5, p. 196.

1843.
Nnevla lirata (Conbad), Hall. Prelim. Notice Lamellibranchiatn, 2, p. 3. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 45, figs. 17-27. 1883.

Not Nueula lineata (Phillips). Paljeozoic Fossils, p. 39, pi. 18, fig. 64. 1841.

Shell of medium size, ovate-triangular; length from one-third to one-fourth
greater than the height; basal margin regularly curving, more abruptly
rounded at the posterior extremity ; cardinal margin slightly arcuate, grad-
ually sloping toward the posterior. Anterior end short, sub-truncate, usually
abruptly rounded.

Valves very gibbous, ventricose in the umbonal region.

Beaks, at the anterior third or fourth of the length of the shell, distant,
elevated, rising considerably above the hinge-line. Umbo very prominent.
Umbonal slope elevated and rounded, merging into the general convexity
before reaching the posterior end.

Test thick, marked by regular, strong, sub-angular concentric undulations,
which are crossed by extremely fine radiating striae. In older shells the
margins are marked by fine, concentric striae, the strong undulations having
become obsolete.

The characters of the interior are strongly marked, as shown in figs. 24,
25, plate xlv.

A specimen preserving both valves in contact has a length of 21 mm.,
height 14.5 mm., and depth of both valves 12 mm. Three separate valves
measure respectively 22, 20 and 18 mm. in length, and 17, 15.5 and 12 mm.
in height.

LAMELLIBRANCHIATA. 317

This species is readily distinguished from any of the associated species by the
strongly Urate surface. It differs also from JV. Randalli in its surface strise,
lesser gibbosity and more distant beaks.

Formation and localities. In the shales of the Hamilton group, on the shores
of Skaneateles, Cayuga and Seneca lakes, N. Y.

NUCUL-A. SUBELLIPTICA.

PLATE XLV, FIG. 28.

NucuXa subelliplica. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 45, fig. 28, 1883.

Shell large, ovate, wider behind ; length about one-fourth greater than the
height ; basal margin regularly rounded, abruptly curving into the anterior
end. Posterior end rounded. Cardinal line slightly arcuate. Anterior end
short and abruptly rounded.

Valves convex, gibbous in the middle and on the umbonal region.

Beaks sub-anterior, prominent, rising above the hinge-line. Umbo gib-
bous. Umbonal slope I'ounded, becoming obsolete before reaching the post-
basal extremity.

Test and surface markings not observed.

The specimen is a cast of the interior, showing strong muscular scars and
the remains of very numerous and small post-cardinal teeth.
• The internal mould has a length of 27 mm., and a height of 20 mm., with
a depth to both valves of about 15 mm.

This species is distinguished from others of the horizon of the Hamilton
group, in its regular ovate form, which is broader behind, and by its rounded
umbonal slope. It somewhat resembles certain forms of N. bellistriata , but it is
a larger shell, more elongate in outline, with more prominent beaks and more
numerous hinge-teeth.

Formation and locality. In the shales of the Hamilton group, near Cumber-
land, Md,

41

318 PALEONTOLOGY OF NEW YORK.

NUCULA BELLISTRIATA.

PLATE XLVI, FIGS. 1-9.

NucuiUes beUaatrUtta, Cokrad. Geol. Sui-v. N. Y., Ann. Rep., p. 40. 1841.

Nucula beUaatriata (Conrad), Hall. Pi-elim. Notice Lamellibianchiata, 2, p. 2. 1870.

.< «" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 4(5, tigs.

1-11. 1883.

Shell of medium size, broadly ovate, usually somewhat wider behind ; length
about one-fourth greater than the height ; basal margin regularly curving.
Posterior end broad and rounded. Cardinal line oblique and arcuate. Ante-
rior end short, declining rapidly from the beaks, and abruptly rounded below.

Valves convex, gibbous on the umbo.

Beaks, at about the anterior fourth, appressed, rising above the hinge-line,
directed forward. Umbonal slope rounded, extending from the beaks in an
arching direction, to above the post-basal extremity.

Surface marked by fine, regular, sharp, concentric strias, which do not
appear to be aggregated into fascicles, but are sometimes interrupted, and the
surface undulated by strong varices of growth.

The cast of the interior shows the strong muscular impressions and a
broad, thickened hinge.

Three specimens measure respectively 21, 17 and 16 mm. in length, and
14, 13 and 12.5 mm. in height.

The distinguishing chariicters of this species are its broad and sub-circular
form and regular concentric striae. In some of its phases it resembles N. vari-
cosa, but that species is sub-trigonal in outline, with larger incurved beaks, and
the striae are fasciculate, forming strong undulations of the surface at irregular
intervals. It is less gibbous and broader than N. Randalli, the striae are finer,
usually without varices of growth, and the beaks more appressed and directed
forward.

Formation and localities. In the shales of the Hamilton group, in Schoharie
county ; near Smnyra, Chenango county ; at numerous localities in Onondaga
county, and on the shores of Seneca, Cayuga and Canandaigua lakes, N. Y.

LAMELLIBRANCHIATA. 319

NUCULA VARICOSA.

PLATE XLVI, FIGS. 12-23 ; AND PLATE XCIII, FIG. 4.

Nucida mricosa. Hall. Prelim. Notice Lamellibranchiata, 2, p. 2. 1870.

" " " Pal- N. Y., vol. V, pt. 1. Plates and Explanations : PI. 46, figs. 13-23. 1883.

Shell of medium size, ovate-triangular; length somewhat greater than the
height ; basal margin curving, more abruptly rounded posteriorly ; post-car-
dinal margin arcuate or sub-truncate. Anterior end very short and abruptly
rounded below.

Valves gibbous, ventricose in the umbonal region.

Beaks sub-anterior, prominent, incurved, arching over the hinge-line.
Umbonal slope narrowly rounded, arching upward and extending from the
beaks to the post-basal extremity. Post-cardinal slope narrow.

Test strong, marked by fine, irregular, concentric stria3, and by numerous
varices of growth, which are closely arranged on the marginal portions of
the shell.

Hinge strong, and posterior to the beaks it is marked by a narrow row of
very fine transverse teeth. Other characters of the interior unknown.

Four characteristic specimens measure respectively 18, 17, 16 and 15 mm.
in length, and 14, 16, 15 and 12 mm. in height.

This species is more erect and the beaks much more elevated than in N. belli-
striata ; it is higher in proportion to the length, giving a more triangular outline,
while the concentric striae are finer, with numerous strong varices of growth.

Formation and localities. In the shales of the Hamilton group, on the shores
of Cayuga lake ; and at Bellona, Yates county, N. Y.

NuCULA COBBULIFORMIS.

PLATE XLVI, FIGS. (10, 11 ?), 24-34 (35, 36, 37 ?).

Nttcula coHmliformis, Hall. Prelim. Notice Lamellibranchiata, 2, p. 2. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 46, figs. 24-37.

Shell of medium size, or smaller, broadly triangular, sub-ov.ate ; length about
one-fpurth greater ihm the height; basal margin broadly curving, more

320 PALAEONTOLOGY OF NEW YORK.

abruptly rounded at the posterior extremity. Cardinal line declining from
the beaks in both directions. Anterior end sloping rapidly from the beaks
and rounded below ; posterior end longer and more pointed.

Valves convex, gibbous in the umbonal region.

Beaks usually at about the anterior third, sometimes sub-central, short,
mo<lerately elevated, brosid and slightly incurved. Umbonal slope not dis-
tinctly defined, rounded, direct, extending to the post-basal extremity.

Surface marked by very fine concentric striae, and by irregular varices of
growth, which sometimes produce strong undulations in the surface of the
shell.

The post-cardinal teeth are large and strong, contrasting with the preced-
ing species, N. varicosa.

Three specimens measure respectively 17, 16 and 14 mm. in length, and
12.5, 12 and 9 mm. in height.

This species is distinguished by its sub-equilateral triangular form.

Formations and localities. In the shales of the Hamilton group, on the shores
of Cayuga, Seneca and Canandaigua lakes ; and a single doubtful specimen from
the Chemung group, of Ithaca, N. Y.

NUCULA LAMELLATA.

PLATE U, FIGS. 18-21i PLATE XLV, FIG. 13; AND PLATE XCIII, FIG. 7.

Xwtila laiaellata. Hall. Pal. N. Y., vol. v. pt. 1. Plates and Explanations : PL hi, tigs. 18-21. 1883.

Shell small, elongate-ovate, truncate behind ; length twice the height ; basal
margin broadly curving, straight, or slightly arcuate in the middle ; poste-
rior margin short, obliquely truncate. Cardinal line straight, directed some-
what upward toward the anterior. Anterior end large and regularly
rounded.

Valves gibbous, with a broad flattened depression extending from the beaks
to the base and sometimes slightly constricting the margin.

Beaks sub-central or posterior to the middle of the shell, incurved, rising
a little above the hinge-line. Umbo gibbous. Umbonal slope obtusely sub-

LAMELLIBRANCHIATA. 321

angular, extending from the beak to the post-basal extremity, declining
abruptly to the cardinal line.

Surface marked by strong, regular, lamellose, concentric striae which
appear to be made up of aggregations of extremely fine striae.

Six or eight strong transverse teeth are preserved on each side of the beak.

Three specimens measure respectively 9, 8 and 7 mm. in length, and 4.5,
4, and 3.5 mm. in height.

This species is remarkable for its sub-central beaks and obliquely truncate
posterior end, in which characters it differs from all others of the genus
described in this volume. In its surface characters it is similar to N. lirata
except that no radiating striae have been observed, but the form of the shell
is otherwise very different.

Formations and localities. In the shales of the Hamilton group, on the shore
of Cayuga lake, and in the lower part of the Chemung group, at Ithaca, N. Y.

NUCUL.\ UMBONATA.

PLATE Xr.VII, FlCiS. SI, 52.
Nucula umbonata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 47, figs. .51, .52. 1883.

Shell large, broadly ovate, wider in front ; length somewhat greater than the
height ; basal margin gently curving in the middle and abruptly rounded at
both extremities. Cardinal line sloping both anteriorly and posteriorly from
the beaks. Anterior end very short and rounded.

Valves gibbous, rising from the basal margin to the umbo, which is the
point of greatest gibbosity ; sloping abruptly to the anterior and posterior
cardinal margins.

Beaks at about the anterior fourth of the length, obtuse, scarcely rising
above the hinge-line. Umbo very prominent and gibbous. Umbonal slope
defined, rounded, extending from the beaks to the post-basal extremity.

Test and markings not preserved in the specimen described, which is a
partial cast of the interior, showing the elongate vertical anterior muscular
scars.

322 PALEONTOLOGY OF NEW YORK.

The specimen has a length of 21 mm., height 18 mm. and a depth to both
valves of 14 mm.

This species is distinguished by its broadly ovate form, very prominent
umbones and short anterior end.

Formation and locality. In the Chemung group, at Mansfield, Pa.

NUCULA DIFFIDENS, n. Sp.

PLATE XLV, FIGS. 12, M.

In part Nuetila RandaUi, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 45, figs. 5-16.

1883.

Shell of about medium size ; narrowly ovate ; length less than twice the
height; basal margin less curved toward the anterior and more curved
toward the posterior. Posterior extremity narrowly rounded. Cardinal line
declining posteriorly. Anterior end short, and abruptly rounded below.

Valves gibbous in the middle and above.

Beaks at the anterior third, prominent. Umbonal slope obtusely sub-
angular, merging into the general convexity of the valve before reaching
the posterior margin.

Surface marked by fine concentric striae, which are often irregularly
fasciculate, especially toward the margin. Muscular impressions strongly
marked. Teeth well developed.

Three specimens measure respectively 19, 17 and 16 mm. in length, and
11, 10 and 9 mm. in height.

This species resembles some of the smaller forms of N. RandaUi, but the
posterior end is wider, beaks less elevated and the umbonal slope is not so
strongly defined.

Formation and localities. In the shales of the lower Chemung group at Ithaca,
and in Chemung county, N. Y.

NuCULA OLOBULARIS, n. Sp.
PLATE XCni, FIG. 6.

Shell robust, of medium size ; sub-globose ; length somewhat greater than the
height ; basal margin regularly rounded, abruptly curving at both extrem-

LAMELLIBRANCHIATA. 323

ities ; posterior end regularly rounded. Cardinal margin declining on both
sides of the beak. Anterior end abruptly rounded below.

Valves ventricose.

Beaks at about the anterior third, rounded, incurved. Umbonal region
very gibbous. Umbonal slope not defined, rounded.

Surface marked by regular, sharp, concentric striae with a few varices of
growth. Interior unknown.

A specimen has a length of 20 mm. and a height of 17 mm.

This species somewhat resembles, in outline, N. bellistriata, but it is more
ventricose, the be.aks more erect and the umbonal slope is less defined.

Formation and localities. In a conglomerate of the Chemung group, associated
with Ptychopteria Sao and Spirifera Vemeuili, east of Panama, N. Y., and at
Warren, Pa.

NUCULA HOUGHTONI.

PLATE XLV, FIGS. 29-31.

NucuXa Houghtoni, Stbvbks. Am. Jour. Sci., 2d series, vol. 25, p. 262. 1858.
Nucvla Icwensis, Whitb and Wiiitfibld. Proc. Bo.st. Soc. Nat. Hist., vol. 8. 1862.

" " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 45, figs. 29-31. 1883.

Shell of medium size, ovate, sub-trigonal ; length more than one-fourth greater
than the height ; basal margin broadly curving, abruptly rounding into both
extremities. Cardinal line sloping rapidly from the beaks to the anterior
and posterior extremities. Anterior end short, declining rapidly from the
beaks and abruptly rounded below.

Valves gibbous, ventricose in the umbonal region.

Beaks at about the anterior fourth, prominent, arching over the hinge-line.
Umbo prominent. Umbonal slope defined, rounded, extending from the beak
to the posterior extremity of the shell.

Test strong, marked by very fine concentric striae which are scarcely fas-
ciculate on the body of the shell.

There are about ten strong teeth posterior to the cartilage pit, and five
anterior ones. Muscular scars strongly impressed.

324 PALJEONTOLOGY OF NEW YORK.

Tho three specimens figured are of about the same dimensions, having a
length of 17 mm. and a height of 13 mm.

This species resembles N. RandaUi, but is a shorter form, broader posteriorly,
and with a more arcuate cardinal line. It has been I'eferred to Tellinomya by
some authors, but in the specimens described (see fig. 31) there is a distinct
cartilage pit beneath the beaks, which character does not belong to Tellinomya
or Pal^onetlo. A comparison of the specimens figured with the type of the
species shows their identity.

Formation and localities. In the sandstones of the Waverly group, at Newark
and Richfield, 0., and near Hillsdale, and at Battle Creek, Mich.

NUCULITES, Conrad. 1841.

NUCCLITES OBLONGATUS.

IT.ATE XLVII, FIGS. I-IJ,

Nvctdltex Moiigata, Conrad. GpoI. Siirv. N. Y., Aim. Rep., \i. ;'>(), |)liite, fig. 8. 1841.

" " " Hall. Prelim. Notice Ijimellibranchiata, 2, j). 4. 1870.

" " " •• Pal. N. Y., vol. V, pt. 1. Plates ami Explanations: PI. 47, figs.

1-12. 1883.
Nuenldf Mmiga, Hall. Geol. Siirv. N. Y., Rep. Foiii'tli DLst., pp. 196-7. 1843.

Shell somewhat larger than the prevailing forms belonging to this group, elon-
gate-ovate, widest at the anterior end; length usually more than twice the
height ; ba.sal margin nearly straight, .sometimes gently arcuate ; posterior
extremity narrow and abruptly rounded. Cardinal line slightly oblique,
gently arcuate; just anterior to the beaks a small portion of the hinge is bent
abruptly downward, reaching to the anterior muscular scar. Anterior end
short and rounded, defined in the cast by the vertical clavicle.

Valves depressed-convex in the lower find posterior portions, more convex
on the anterior end and in the umbonal region.

Beaks at about the anterior fourth, appressed, not rising above the hinge-
line. Umbonal slope broadly rounded and undefined, extending to the post-
inferior extremity.

Test thick in the upper part of the shell. Surface marked by very fine

LAMELLIBRANCHIATA. 325

concentric strioe of growth, which are sometimes scarcely fasciculate on the
lower portion of the shell.

Hinge furnished with numerous transverse teeth, as represented in figs.
7-9, plate xlvii.

There is a strong vertical clavicular ridge just anterior to the beaks which
extends for more than half the height of the shell. Anterior muscular scar
sub-circular, distinct, situated within the cavity of the anterior end.
Posterior scar narrow-ovate, very close to the post-cardinal margin. Umbo
marked by three or four strong muscular pits. Pallial line distinct, distant
from the margin of the valve.

Four specimens measure respectively 35, 33, 26 and 24 mm. in length and
20, 15, 12 and 11 mm. in height.

This species more nearly resembles N. cuneiformis than any other, but is
readily distinguished by its shorter anterior end, wider post-cardinal slope and
rounded urabonal ridge. It also resembles Nucula [Nuculites] ovata, Sowerbv, as
identified by Phillips, but is somewhat more elongate in form, with the post-
cardinal line less oblique.

Formation and localities. In the shales of the Hamilton groujj, in Schoharie
and Otsego counties ; on the shores of Skaneateles, Cayuga, Seneca and Canan-
daigua lakes, and numerous localities in Western New York ; also in the same
horizon at Patterson's creek, Va.

Nuculites cuneiformis.

I'l-ATK XLVII, FI(!S, IS-IC.

Nucidifes cuneiformU, Conrad. Geol Surv N. Y., Ann. Rep., p. 50, plate, fijf. 7. 1.S41.
" " " Hall. Prelim. Notice Lamellibranoliiata, 2, p. 4. 1S70.

« «< " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations ; PI. 47, figs.

13-1(;. 1883.

Shell of medium size, elongate-ovate, cuneiform, widest in front and pointed

behind; length usually more than twice the height; basal margin gently

curving in the anterior part, becoming nearly straight behind, and abruptly

rounded into both extremities. Posterior extremity narrow, pointed, obliquely

42

326 PALEONTOLOGY OF NEW YORK.

truncate. Cardinal line nearly straight. Anterior end sloping I'apidly in a
straight line from the beaks, and abruptly rounded below.

Valves depressed-convex below, becoming convex and sometimes gibbous
in the umbonal region.

Beaks at about the anterior fourth, slightly incurved and rising .above the
hinge. Umbonal ridge angular, extending from the beak to the posterior
extremity ; post-cardinal slope abrupt.

Test marked by fine concentric striaa which are sometimes fasciculate on
the lower portions of the shell.

Internal characters similar to those of the preceding species.

Two specimens measure respectively 32 .and 29 mm. in length and 15 and
14 mm. in height.

This species is distinguished by its elongate cuneate form. It appears to be
a rare species, as but few specimens have been obsei'ved among extensive collec-
tions from the localities where it occurs.

Formation and localiiks. In the shaly sandstones of the Hamilton group, at
Jefferson and Fultonham, Schoh.arie county ; and Oneonta, Otsego county, N. Y.

NUCDLITES TRIQUETER.

PLATE XLVU, CIGS. I7-2S ; AND PLATK XCIII, FIGS. S-10.

NuculiteJi Iriqueter, Courad. Geol. Surv. N. Y., Ann. Rep., p. 50. 1841.

" " " Hall. Prolini. Notice Lamellibranchiata, 2, p. 4. 1S70.

" " " " Pal iV. Y., vol. V, pt. 1. Plates and Explanations : PI. 47, figs. 17-

LM. 1S83.

Shell of medium size, or larger, trigon.al, short; length from one-fourth to
one-third greater th.an the height ; ba.sal m.argin regularly curving, sometimes
straight on the posterior portion, abruptly rounded into both extremities ;
posterior margin obliquely truncate ; cardinal margin arcuate. Anterior
end short, rounded.

Valves convex, gibbous in the middle and above.

Beaks at the anterior third or fourth, very prominent, incurved, arching
over the hinge. Umbo prominent and gibbous. Umbonal ridge distinct.

LAMELLIBRANCHIATA. 327

sub-angular, arching upward and extending from the beak to the post-inferior
extremity. Post-cardinal slope short, descending abruptly from the angular
umbonal ridge to the obliquely truncate posterior margin.

Test thin, marked by very fine concentric striae which do not appear to
have been fasciculate.

Hinge comparatively short, furnished with more than twenty small teeth,
which are continued in a row under the beaks without interruption. Mus-
cular scars faintly marked. Clavicular ridge or septum very strong, sharply
defined and curved.

Three specimens of average size measure respectively 17, 16 and 12 mm.
in length, and 13, 13 and 10 mm. in height, and 11, 10 and 8 mm. in the
depth of both valves.

This species is somewhat similar in form to Nucula varicosa, but it attains a
much larger size, the umbonal slope is distinctly angular, and the surface is
usually smooth, or marked by very fine concentric lines, while the impression
of the curved muscular ridge or clavicle just anterior to the beaks serves to
distinguish the casts, in which condition the specimens are usually found.

This form presents a wide variation in size and specific characters. Some of
the specimens here included under this species were originally designated as
N. Nyssa, but larger collections have shown that they are only extreme varieties
of form. That species is now limited to the original specimens from the shales
in the western portion of the State, which seem to possess sufficient differences
to warrant a separate specific designation.

Formations and localities. In the shales of the Hamilton group, in Onondaga
county ; on the shores of Otisco, Skaneateles, Cayuga and Seneca lakes, N. Y. ;
and at Patterson's creek, Va. Several small specimens, apparently of this spe-
cies, have been found in the Marcellus shale, at Leroy and West Bloomfield,
N. Y.

328 PALEONTOLOGY OF NEW YORK.

NCCULITES NySSA.
PLATE XLVII, KlUS. 29, 30.

NucitlUex ?fj/i>xa. Hall. Prelim. Notice Lainellil>ranchiat«, 2, y>. 5. 1870.

In iMirt " " " Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 47, fig^s. 25-30. 1883.

Shell of medium size, broadly ovate, wider anteriorly ; length about one-third
greater than the height ; basal margin regularly curving, abruptly rounding
into both extremities; posterior margin oblique, sulj-truncate above and
abruptly rounded below. Cardinal line short, slightly arcuate. Anterior end
short, rounded.

Valves highly convex, gibbous in the umbonal region.

Beaks at about the anterior fourth, incurved, rising a little above the hinge.
Umbonal ridge prominent, extending to the post-hiferior extremity. Cardinal
slope abrupt.

Surface marked by fine concentric striae, which are slightly fasciculate,
producing low undulations of the surface.

Muscular scars faintly impressed. Clavicular ridge narrow, curving toward
the anterior end and extending about two-thirds the height of the valve.

The two specimens described measure respectively 18 and 14 mm. in
length and 12 and 10 mm. in height.

This species closely resembles N. triqueter, but has a more ovate form ; the
other comparisons are given nnder the description of th.at species.

Formation and localily. In concretionary layers in the shales of the Hamilton
group, on the shore of Lake Erie.

LAMELLIBRANCHIATA. 329

LED A, Schumacher. 1817.
Leda diversa.

PLATE XLVII, FIGS. 31-37.

Leda (Nuculana) diversa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : Pi. 47, fi^. 31-37.

1883.

Shell small, ovate-cuneate ; length about twice the height ; basal margin curv-
ing in the anterior portion, becoming straight or nearly so, behind. Posterior
extremity acuminate. Cardinal line straight, oblique. Anterior end propor-
tionately large, declining rapidly from the beak and regularly rounded below.

Valves gibbous in the anterior and umbonal regions, attenuated behind.

Beaks at about the anterior third, prominent, incurved, rising above the
hinge-line. Umbo prominent, obtuse. Umbonal ridge sub-angular, extend-
ing from the beaks to the posterior extremity; the surface sloping abruptly
from this ridge to the hinge-line.

Surface marked by fine, regular, concentric striae which are merged into
the umbonal ridge and are obsolete on the cardinal slope. Interior unknown.

A specimen of the usual form has a length of 10 mm. and a height of 5
mm. A somewhat larger and shorter individual has a length of 11 mm. and
a height of 6 mm.

This species differs from L. brevirostris in being narrower and more elongate
posteriorly, with more anterior beaks, and more direct umbonal ridge.

Formalion and localities. In the soft calcareous shales of the Hamilton group,
at Bear's gulf and Jefferson, in Schoharie county, and in Onondaga county,
N. Y.

Leda brevirostris.

PLATE XLVII, FIGS. 38-41.

Ledaf brevirostris. Hall. Pi-elira. Notice Lamellibranchiata, 2, p. 6. 1870.

Leda (Nwulana) brevirostris. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 47, figs. 38, 39

(40, 41 ? ). 1883.

Shell small, ovate-triangular, abruptly nasute behind ; length about one-third
greater than the height; basal margin broadly curved in the anterior por-

330 PALEONTOLOGY OF NEW YORK.

tion, becoming straight toward the posterior. Posterior extremity abruptly
acute, not attenuate. Cardinal line straight, oblique. Anterior end large,
broadly rounded, comprising half the shell.

Valves convex, very gibbous in the anterior portion and in the umbonal
region.

Beaks behind the anterior third, prominent, rising above the hinge-line.
Umbonal ridge defined, angular, curving downward, abruptly sloping to the
posterior extremity.

Surface marked by fine, even, concentric striae, which are obsolete on the
post-cardinal slope. Interior unknown.

Two specimens measure respectively 9 and 11 mm. in length, and 6 and 7
mm. in height.

This species differs from L. rostellata in the shorter and less curved posterior
end ; the anterior portion is broader and more extended ; the beaks are more
distant from the anterior extremity.

Formation and localities. In the shaly sandstones of the Hamilton group, from
near Summit and Jeflferson, Schoharie county, N. Y.

Leda rostellata.

PLATE XLVU, FIGS. 42-47.

NuculUes rostellata, Cokrad. Geol. Surv. N. Y., Ann. Rep., p. 50. 1841.
Ledat rostellata (Conrad), Hall. Pi-elim. Notice LanielliViranchiata, 2, p. 5. 1870.
Leda (Nucidana) rostellata (Conbad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 47,

figs. 45-47. 1883.
" " perstriata, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations ; PI. 47, figs.

42-44. 1883.

Shell small, falciform; length more than twice the height; basal margin
gently curving from the posterior extremity, more rapidly curving anteriorly.
Posterior end attenuate, arching upward, with the extremity narrowly
rounded or sub-truncate. Cardinal line oblique, declining posteriorly, and
regularly curved. Anterior end comparatively short, abruptly rounded.

Valves convex, somewhat gibbous in the umbonal region, depressed-convex
posteriorly.

LAMELLIBRANCHIATA. 331

Beaks between the anterior third and fourth of the length of the shell,
prominent, rising above the hinge-line. Umbonal ridge distinctly defined,
sharply angular above, becoming truncate below in its extension to the
posterior extremity.

Surface marked by fine, regular, equal, sharp concentric strise, which con-
verge upon the posterior end of the shell, cross the umbonal angle, and are
obsolescent on the post-cardinal slope.

Hinge crenulated with minute teeth which extend half the distance from
the beak to the posterior end.

Three specimens measure respectively 16, 13 and 10 mm. in length, and
6.5, 6, and 4.5 mm. in height.

This species differs from L. diversa in its more elongate form, in the more re-
curved and falcate posterior extremity, proportionally more anterior beaks, finer
and more regular stria), which do not become confluent on the umbonal ridge.

Some of the specimens are marked by extremely fine striae, which are scarcely
visible except under a magnifier. This character, and their somewhat shorter
form, led to their separation under the name of L. persiriata, but the distinction
is found not to be tenable, as in some specimens the striae are extremely fine in
the upper part of the shell, and have the characteristic appearance of typical
specimens of L. rostellata in the lower part. The older individuals are more
extremely attenuate behind than the younger specimens.

Formation and localities. In the shales of the Hamilton group, on the shores
of Skaneateles, Owasco and Seneca lakes, and at Pratt's falls, Onondaga
county, N. Y.

Leda obscura, n. sp.

PLATE XLVII, FIG; 48.

Leda (Nuculana) curta, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 47, fig. 48. 1883.
Not Leda curta, Mbbk. Proe. Acad. Nat. Sci. Phila. 1861.

Shell small, ovate-triangular, acute at the posterior extremity ; length one-third
greater than the height. Gibbous in the umbonal region, and regularly con-
vex below, with a slight depression at the base toward the posterior end.
Beak between the middle and anterior third. Umbonal ridge not defined.

332 PALEONTOLOGY OF NEW YORK.

Surface marked by fine, sharp, regular, concentric striae.

The specimen described has a length of 6.5 mm. and a height of 4.5 mm.

A single specimen only has been observed. It possesses the general form
and surface characters of Leda with some indications of its relations with
PAL.EONEILO in its depressed post-basal margin.

Formation and locality. In the arenaceous shales of the Hamilton group, at
Fultonhara, Schoharie county, N. Y.

Leda pandoriformis.

PLATE XLVII, FIGS. 49, 50.

Leda pandnrifonnis, Stkvens. Am. Jour. Sci., 2d ser., vol. 25, p. 262. ISSS.

Leda {Nuculana) Oh'weiisis, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 47, figs. 40, ."jO.

1883.

Shell large, elongate-ovate, sub-cuneate; length more than twice the height;
basal margin regularly curving in the middle and posteriorly, more abruptly
toward the anterior end. Posterior extremity attenuate, abruptly rounded
or sub-truncate. Cardinal line oblique, declining from the beak, and slightly
curving upward. Anterior end, in the cast, obliquely sub-truncate above,
and regularly rounded below.

Valves moderately convex, scarcely gibbous in the umbonal region, de-
pressed-convex or somewhat flattened along the posterior half.

Beaks at about the anterior third, rising above the hinge-line. Umbonal
ridge obtusely angular, extending to the posterior extremity.

Surface characters unknown.

Hinge marked both anteriorly and posteriorly by a row of slender teeth,
with a sub-rostral ligamental pit, which is imperfectly represented in the figure.

The specimen described has a length of 26 mm. and a height of 12 mm.

This species is larger than any other form here described, with a broader
posterior end. It has somewhat the shape of L. diversa, but is less gibbous in
the anterior portion and less abruptly attenuate behind.

Formation and locality. In the Waverly sandstone of Newark, 0., and at Bat-
tle Creek, Mich.

LAMELLIBRANCHIATA. . 333

PAL^ONEILO, Hall. 1870.

Pal^eoneilo constricta.
plate xlviii, figs. 1-16 ; axd plate li, fig. 17.

Nuctditeg amstrieta, Conkad. Jour. Aead. Nat. Sci. Phila., vol. viii, p. 249. PI. 1,'), fifr. 8. 1842.
Niicula bellatula. Hall. Geol. Sui-v. N. Y., Rep. Fourth Dist., p. 197, t. 78, fig. 7. 1843.
PalcBoneilo coiistricta (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 7. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 48, figs.

1-15. 1883.

Shell of medium size or smaller ; ovate-cuneate, sub-nasute behind ; propor-
tions of length and breadth extremely variable, the length usually about
one-third greater than the height ; basal margin rounded in the middle and
anterior portions, straight or slightly constricted toward the posterior end.
Posterior extremity narrowed, cuneate or sub-nasute, constricted below.
Cardinal line abruptly declining anterior to the beak, and more gently
declining to the posterior. Anterior end abruptly rounded.

Valves convex below and posteriorly, becoming gibbous above the middle
and in the umbonal region.

Beaks at about the anterior third, prominent, rising above the hinge-line.
Umbon.al ridge rounded, not strongly defined, with a depression or undefined
furrow below it, which extends from just posterior to the beak to the post-
inferior margin.

Surface, in well-preserved specimens, marked by fine, regular and even,
thread-like stria?, which frequently become obsolescent in the furrow and on
the post-cardinal slope.

Anterior and posterior muscular impressions strongly marked, and with
umbonal muscular scars. Hinge marked by numerous crenulations, which
are coarser toward the anterior and posterior extremities.

Three specimens measure respectively 20, 20 and 25 mm. in length, and
14, 12 and 18 mm. in height. Two extreme examples have respective lengths
of 23 and 16 mm. and heights of 13 and 13 mm.

This species is of about the size of Nucula bellistriata, and striated in the same
manner, but is readily distinguished by its form and constricted posterior end,
43

334 PALEONTOLOGY OF NEW YORK.

It is proportionally much higher than P. plana and smaller and more constricted
than P. maxima.

Formations and localities. In the shales of the Hamilton group, Fultonham
and Bear's gulf, Schoharie county; shores of Seneca and Cayuga lakes, N. Y.,
and Patterson's creek, Va. ; in the Portjige group, at Portland Harbor, Chautau-
qua coimty, and in the lower Chemung or Ithaca group, at Ithaca, N. Y.

Pal^oneilo constbicta, yar. flexuosa.

PLATE XLVIII, FIGS. 17-20.

PalfBoneilo constricta (CoMBADsp.), tjar. flexuoxa. Ham,. Pal. N. Y., vol. v, jit. I. Plates and Explanations :

PI. 48, tigs. 16-20 (16 in error). 18S3.

Specimens having the general aspect of P. constricta occur in the Chemung
group, at Ithaca. The shell is stronger, more elongate in form, more coarsely
and irregularly striated with the constriction at the posterior end strongly
marked.

Formation and locality. In the lower part of the Chemung group, at Ithaca,

N. Y.

Pal^eoneilo plana.

PLATE XLVUI, FIGS. 21-28.

PalcBoneilo plaTta, Hall. Prelim. Notice Lainellibranchiata, 2, p. 7. 1870.

" " Pal. N. Y., vol. .5, pt. 1. Plates and Explanations : PI. 48, figs. 21-28. 1883.

Shell below the medium size, transversely elliptical, compressed, elongate and
somewhat pointed behind ; length almost twice the height ; basal margin
regularly and gently rounded, with a slight and undefined constriction near
the posterior end. Posterior extremity acutely rounded. Cardinal line
declining on each side of the beak. Anterior end regularly rounded.

Valves depressed-convex.

Beaks anterior to the centre, small, rising but little above the hinge-line.
Umbonal slope not defined, obscurely indicated by an undefined depression,
which scarcely constricts the margin.

Surface marked by very fine concentric striae, which are often obscure or
obsolete. Interior as shown in figs. 25, 26 of plate xlviii.

Several specimens have a length of 15 mm. and a height of 8 mm.

LAMELLIBRANCHIATA. 335

This shell is delicate in texture, smaller, more elongate, and with beaks more
nearly central than P. consirida.

Formations and localities. In the shales of the Hamilton group, in Otsego
county, on the shores of Cayuga, Seneca and Canandaigua lakes ; and in the
lower beds of the Chemung group, at Ithaca, N. Y.

Pal^oneilo maxima.

PLATE XLVni, riGS. 29-38.

NveidUeg maxima, Conrad. Geol. Surv. N. Y., Ann. Rep., p. 50. 1841.
Tdlinat ovata. Hail. Geol. Surv. N. Y., Rep. Fourth Dist., p. 196, fig. 6. 1843.
PaloBoneilo ■maxima (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 9. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 48, figs. 29-

38. 1883.

Shell large, ovate-acute ; length one-half greater than the height ; basal margin
very convex in the middle, curving regularly to the anterior end, and more
nearly straight behind. Posterior extremity narrow and abruptly rounded,
or sub-truncate at the termination. Cardinal line declining rapidly on either
side of the beak. Anterior end somewhat narrowly rounded.

Valves regularly convex below, becoming gibbous in the middle and above.

Beaks anterior to the centre, prominent, small, with the apices very
slightly incurved. Umbonal ridge distinct, sub-angular, extending to the
upper side of the posterior extremity ; the furrow below is broad, obscure
and undefiued.

Surface marked by fine concentric strige, which are often very obscure or
obsolescent. Muscular scars unknown. Hinge-line crenulate, but not prop-
erly represented in figs. 37 and 38 of plate xlviii.

Three specimens measure respectively 31, 32.5 and 35 mm. in length, and
17, 19 and 20 mm. in height.

This species differs from all the preceding in its more gibbous form and
abruptly contracted posterior end, approached only by some of the elongate
forms of P. constrida. Its internal characters are obscure.

Formation and localities. In the shales of the Hamilton group, at Summit and
Fultonham, Schoharie county, and on the shores of Cayuga lake, N. Y.

336 PALEONTOLOGY OF NEW YORK.

Pal^oneilo tenuistriata.

PLATE XLIX, FIGS. l-II, U ; AND PLATE XCIII, KIG. 13.

Palaoneilo tenttMriata, Hall. Pi-clim. Notice Lamellibraiichiata, 2, p. 9. J 870.

Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 49, figs. 1-12. 1883.

Shell large, ovate-elliptical ; length more than one-third greater than the
height; basal margin regularly curving. Posterior end doubly truncate.
Cardinal line gently arcuate. Anterior end short, rounded.

Valves convex, gibbous above the middle and in the umbonal region.

Beaks at about the anterior third, moderately prominent, nearly straight,
little elevated above the hinge-line. The posterior end of the shell is
depressed-convex, with a more or less distinct depression extending to the
post-inferior extremity from just posterior to the beaks, giving a truncation
and slight constriction of the margin.

Test thick, especially in the dorsal region. Surface marked by very fine
concentric striae, which are often crowded together on the basal and poste-
rior portions of the shell, forming irregular undulations of growth. In some
well-preserved specimens the concentric striae are elevated into sharp lamellae.

Three specimens measure respectively 29, 33 and 37 mm. in length, and
18, 19 and 20 mm. in height.

This species may be distinguished from P. fecunda by its finer and more
irregular surface striae and u.sually shorter form.

Formation and localities. In the soft shales of the Hamilton group, on the
shores of Skaneateles, Cayuga and Seneca lakes ; at Pratt's falls and Delphi,
Onondaga county, and York and Moscow, Livingston county, N. Y. ; also from
Patterson's creek, Va.

Palaoneilo fecunda.

PLATE XLIX, FIGS. 13, 15-24.

Pal(eoneilo fecunda. Hall. Prelim. Notice Lamellibranchiata, 2, p. 8. 1870.

Pal. N. Y., voL V, pt. 1. Plates and Explanations : PI. 49, figs. 13-24. 188.3.

Shell large, elongate-ovate; length nearly twice the height; basal margin
brosidly curving. Posterior end obtusely roiuided or doubly truncate. Car-
dinal line arcuate. Anterior end regularly rounded.

LAMELLIBRANCHIATA. 337

Valves regularly convex below, gibbous above and in the umbonal region.

Beaks at less than the anterior third from the end, moderately elevated
above the hinge-line. Umbonal slope flattened, giving a slight angularity to
the shell above and below it, and an oblique truncation to the posterior
extremity.

Test thick, marked in the anterior portion by fine, regular concentric
striae, some of which become elevated into sharp, lamelliform striae, with
finer intermediate ones on the posterior half of the shell. The characters of
the interior are well shown in figs. 19, 20, 21 and 22 of plate xlix.

Three specimens measure respectively 35, 38 and 43 mm. in length, and
18, 21 and 24 mm. in height.

This species differs little in size and form from P. muta, but is distinguished
by the fine striae on the anterior portion of the shell, and the finer and more
subdued character of the lamellose striae on the posterior part.

Formation and localities. In the soft shales of the Hamilton group, on the
shores of Cayuga, Seneca and Canandaigua lakes ; at Darien, in Genesee county,
at York and Moscow, in Livingston county, N. Y. ; also in Hardy county, Va.

Pal^oneilo muta.

PLATE XLIX, FIGS. 25-32.

PcHOBimeilo muta, Hall. Prelim. Notice Lainellibranchiata, 2, p. 8. 1S70.

•< " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 49, figs. 25-32.

Shell large, elongate-ovate ; length less than twice the height. General form
and convexity similar to the preceding.

Entire surface marked by regular, strong, lamellose elevated striae, with
very fine, intermediate .striae.

Three specimens measure respectively 43, 41 and 35 mm. in length, and
24, 21 and 20 mm. in height.

This species has the form and proportions ot P.fecmda, differing principally
in the character of the surface, which is entirely covered by strong, lamellose

338 PALAEONTOLOGY OF NEW YORK.

striaj, while in that species the same character of surfjice affects only the poste-
rior half of the shell.

In form and proportions, the three species, P. tenuistriata, P. fecunda and P.
muta, are very similar, and might be included under one specific designation,
except for the wide and characteristic differences in the surface ornamentation,
which are constant even among specimens from the same locality.

Formation and localities. In the soft shales of the Hamilton group, on the
shores of Skaneateles, Seneca and Canandaigua lakes ; at North Bristol, in Onta-
rio county ; at Bellona, Yates county, and other localities in Western N. Y.
It likewise occurs in the same formation in Hardy county, Va.

Pal^oneilo emarginata.

PLATE L, FIGS. 1-11.

NuculUes emarginata, Conrad. Geol. Surv. N. Y., Ann. Rep., p. 50. 1841.

Palceonello emarginaia (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, \i. 7. 1870.

" " " " Pal. N. Y., vol. V, pt, 1. Plates and Explanations: PI. 50, figs.

1-12. 1883.

Shell of medium size or larger, sub-elliptical ; length usually more than twice the
height; basal margin gently curving or nearly straight from the post-inferior
angle to the anterior end, where it is more abruptly rounded ; posterior margin
deeply sinuate. Cardinal line gently arcuate. Anterior end regidarly and
somewhat abruptly rounded.

Valves regularly convex in the lower anterior half, becoming gibbous
above.

Beaks at a little less than the anterior third from the end, and, except
in the shorter forms, moderately prominent. Umbonal slope marked by a
strong elevation or ridge, with a depression above it, which produces a
marked emargination. The post-cardinal extremity, above this, is produced
into a linguiform extension, which is sometimes angular, but usually abruptly
rounded at the termination.

Surface marked by strong, elevated, distant, lamellose, concentric ridges,
extending the entire length of the shell, between which are very fine con-

LAMELLIBRANCHIATA. 339

centric stri«. The intermediate striae become obscure or obsolete, according
to the degree of weathering and nature of the matrix.

Five specimens measure respectively 22, 24, 26, 27, 28 and 40 mm. in
length, and 12, 13.5, 16, 12 and 16 mm. in height.

This species is distinguished by its regular, strong, lamelliform, concentric
striae, and deeply emarginate, post-inferior extremity.

Formations and localities. In the arenaceous layers of the Hamilton group, at
Jefferson, Summit and Fultonham, Schoharie county ; in the soft shales on the
shores of Skaneateles, Cayuga, Seneca and Canandaigua lakes, and at other
localities in Western N. Y. ; also in beds of the same age near Cumberland,
Md. It likewise occurs in the lower beds of the Chemung group, at Ithaca, N. Y.

Pal^oneilo perplana.

PLATE L, FIGS. 15-22; AND PLATE XCHI, FIG. 12.

Pakeoneiln f perplana. Hall. Prelim. Notice Lamellibranchiata, 2, p. 12. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. ,50, figs. 15-22. 1883.

Shell large, ovate, sub-cuneate ; length less than twice the height ; basal
margin gently curving, sometimes a little flattened or slightly sinuate in the
posterior portion ; post-inferior margin doubly truncate. Cardinal line gently
arcuate. Anterior end broadly and regularly rounded.

Valves convex in the lower part of the anterior half, gibbous above and
in the umbonal region.

Beaks usually at about the anterior third, sometimes just anterior to the
centre, broad, prominent, rising but little above the hinge-line, gently
incurved. Umbonal slope marked by two broad ridges, separated by a
broad, undefined sulcus, producing sinuations in the post-inferior and post-
cardinal margins; the shell, at the termination of the upper ridge, and
sometimes between the two ridges, is produced into a short, linguiform exten-
sion. Post-cardinal slope flattened or concave.

Entire surface marked by extremely fine, crowded striae, and at intervals
by strong, elevated lamellae, which are usually obsolete, except on the poste-
rior portion of the shell.

340 PALEONTOLOGY OF NEW YORK.

The central portion of the hinge-line is marked by fine crenulations (those
of the extreme ant<?rior and posterior are not determined). The post-cardinal
margin shows two longitudinal folds above the crenulated hinge.

Three specimens measure respectively 43, 38 and 34 min. in length, and
25, 21 and 20 mm. in height.

This species, in its general form, bears some resemblance to P. Jecunda and
P. mtita, but the umbonal ridge is less defined, the posterior extremity is more
extended, and the lamellose striae are more distant. Tlie surface is usually
smooth or polished, and the striae scarcely visible to the naked eye.

The larger proportion of the specimens are from the softer shales, and
extremely compressed, while others, in different conditions of preservation,
show the anterior half of the shell to be gibbous. The first specimens described
were from the soft shales, and gave origin to the name P. perplana.

Formation and localities. In the shales of the Hamilton group, at Fultonham,
and near Summit, Schoharie county ; near Clarksville, Albany county ; on the
shores of Seneca and Cayuga lakes ; and in the town of Bristol, Ontario county,
N. Y.

PALiEONEILO ViRGINICA, n. Sp.
PLATE XCm, FIG. 14.

Shell large, robust, elliptical ; length less than twice the height ; basal margin
gently curving; posterior extremity doubly truncate. Cardinal line long,
gently arcuate. Anterior end large, regularly rounded at the extremity.

Valves regularly convex in the lower and posterior portions, becoming
gibbous in the middle and umbonal regions.

Beaks at the anterior third, low, little elevated above the hinge-line.
Umbonal slope convex, not conspicuously defined in the cast, marked by two
low, rounded, diverging ridges, extending to the post-inferior extremity and
to the middle of the posterior end, forming a short, linguiform extension.
Post-cardinal slope slightly concave.

Surface marked by fine concentric striae which are fascicuhate, forming
undulations on the posterior portion of the shell. The cardinal line, in the

LAMELLIBRANCHIATA. 341

specimen, is partially exposed, showing the characteristic crenulations of the
hinge.

The specimen described has a length of 51 mm. and a height of 30 mm.

The nearest relation of this form is with P. perplana, but it is a much larger
shell and its general form more distinctly elliptical. The surface markings on
the posterior part of the shell are i^recisely similar to that species, but the
specimen described is a cast, and an exact comparison cannot be drawn.

Formation and locality. In the Hamilton group, at Patterson's creek, Va.

PaLjEONEILO arata.

plate l, fig. 23.

PalcBoneilii arata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. '>0, fig-. 23. 1883.

Shell of medium size, sub-elliptical; length about twice the height; basal
margin convex in the anterior half, concave posteriorly, and rather abruptly
recurving. Posterior extremity somewhat prolonged and abruptly rounded.
Cardinal line nearly straight or slightly arcuate. Anterior end regularly
rounded.

Valves moderately convex, gibbous in the umbonal region.

Beaks between the anterior third and fourth, not prominent. Umbonal
slope convex, without defined ridge, merging in the general convexity before
reaching the posterior extremity. Post-cardinal slope concave, constricting
the margin of the shell.

Surface marked by extremely fine concentric striae, which are often obscure
or obsolete, and by distant, strong, elevated, lamellose ridges. Interior
unknown.

The specimen described has a length of 30 mm. and a height of 16.5 mm.

This species somewhat resembles P. tmuistriata and P. fecunda, but there is
an entire absence of an umbonal ridge, or interruption in the curvature of the
posterior part of the shell, and the lamelliform ridges are stronger and more

distant.

44

342 PALEONTOLOGY OF NEW YORK.

Formation and locality. In the shales of the Hamilton group, near Norwich,
Chenango county, N. Y.

PaL^ONEILO BREVIS.

1"LATK L, FIG*. 24-33.

PaltBorurilo brevis. Hall. Pi-elim. Notice Laiucllibi-aiirhiata, 2, ji. 10. 1S70.

" " " Pal. N. Y., vol. V, pt. 1. Plates ami Explanations : PI. 50, figs. 24-33. 1883.

Shell small, ovate, or ovate-sub-triangular; length about ono-thii-d greater than
the height ; basal margin gently curving, with a slight constriction toward
the posterior extremity. Cardinal line arcuate. Anterior end usually short
and regularly rounded.

Valves convex below, gibbous in the middle and on the umbonal ridge.

Beaks usually at about the anterior third or a little posterior thereto,
prominent, moderately elevated above the hinge-line. Umbonal slope
marked by a slight flattening of the shell, which produces a gentle constric-
tion in the post-inferior margin. This depression is rarely margined on each
side by an undefined elevation.

Surface marked by fine, even, concentric striae ; the casts exhibiting only
the stronger elevations which give an irregular appearance to the concentric
striae. Anterior nmscular impression very strongly marked. Posterior scar
large and shallow. Hinge marked by numerous minute crenulations.

Three specimens of this species measure respectively 21, 20 and 14 mm.
in length, and 14, 12 and IC inm. in height.

This species is allied to P. constrida, but is more gibbous, less curved along
the basal margin, and the constriction of the posterior end is so slight as to be
scarcely detected in most individuals.

Formation and localities. In some shaly calcareous sandstones of the Chemung
group, at Franklin, Delaware county ; in arenaceous shales, at Philipsl)urgh,
Alleghany county, N. Y., and at Lawrenceville, Tioga county. Pa.

LAMELLIBRANCHIATA. 343

Pal^oneilo filosa.

PLATE XLIX, FIGS. 33-38.

NucidUes filosa, Conrad. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 250, pi. 15, fig. 7. 1842.
PaUBoneUo filosa (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 10. 1870.

" " " " Pa-1. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 49, figs. 33-38.

1883.

Shell below the medium size, elongate-ovate, or ovate-sub-cuneate in its shorter
varieties; length about twice the height in the prevailing forms. Basal
margin gently curving. Posterior extremity obliquely sub-truncate. Car-
dinal line arcuate ; anterior end regularly rounded.

Valves depressed-convex in the lower part, becoming convex and some-
what gibbous in the middle and in the umbonal region.

Beaks at about the anterior third, rising but little above the hinge-line.
Umbonal slope somewhat flattened.

Surface marked, on the anterior half, by fine concentric striae, which pass
into sharp, elevated, lamellose striae on the posterior half. Interior shown
in figs. 36, 37 and 38 of plate xlix.

Three specimens measure respectively 30, 25 and 23.5 mm. in length, and
15, 13 and 14 mm. in height.

This species is closely allied to P. fecunda, of the Hamilton group, but is
readily distinguished by having the posterior extremity prolonged at the car-
dinal line, giving the greatest length at this point, while in that species the
greatest length of the shell is usually considerably below the cardinal line.
The shell is also smaller, seldom attaining much more than half the length of
P. fecunda.

The prevailing forms, at the original localities, are proportionally longer than
that figured by Mr. Conrad, but there are among them forms of similar pro-
portions as in figs. 37 and 38. There being no other similar species known at
these localities, there can be no doubt of the propriety of this reference.

Formation and localities. In the lower part of the Chemung group, at Ithaca
and Cortland, N. Y.

344 PALAEONTOLOGY OF NEW YORK.

PaljEoneilo angusta, n. sp.

PLATE XCm, FIG. II.

Shell below the raedium size, elongate, sub-elliptical; length about twice the
height; basal margin regularly curving. Posterior extremity produced,
obliquely sub-truncate and doubly emarginate. Cardinal line straight and
long. Anterior end comparatively large and broadly rounded.

Valves very moderately convex below, scarcely gibbous in the middle and
above.

Beaks at about the anterior third, low, closely appressed, rising but little
above the hinge-line. Umbonal slope defined, sub-angular, extending to the
post-inferior extremity. Post-cardinal slope broad, and marked longitudinally
by a distinct angular fold reaching to the posterior margin.

Surface marked by fine concentric striae ; and on the upper anterior por-
tion, the umbo and post-cardinal slope, by regular somewhat distant lamellose
elevations.

Two specimens measure respectively 20 and 26 mm. in length, and 10 and
13 mm. in height.

In its elongate form it bears some resemblance to P. muta, but the post-car-
dinal slope is narrower, the ridge along this slope is stronger and more nearly
central and the posterior extremity is doubly sinuate.

Formation and locality. In the Chemung group, near Elmira, N. Y.

PALiEONEILO BISULCATA.
PLATE L, FIGS. 12-14.

PalcBojieilo bisulcata. Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 10. 1870.

" " " Pill. N. Y., vol. V, lit. 1. Plat«8an<l ExplanatioiiH: PI. 50,tijf8. 13, 14. 1883.

Shell small, broadly sub-ovate ; length nearly one-half greater than the height ;
basal margin regularly curving to the post-inferior extremity. Posterior mar-
gin sinuate, obliquely sub-truncate. Cardinal line arcuate. Anterior end
regularly rounded.

LAMELLIBRANCHIATA. 345

Valves moderately convex, slightly gibbous in the umbonal region.

Beaks small, situated a little more than one-third the length from the
anterior end. Umbonal slope marked by two distinct furrows, which are
limited by three rather sharply angular carinae, one very near the cardinal
line, one along the umbonal angle, and another one intermediate and equidis-
tant.

Surface marked by coarse, regular, elevated, concentric folds which are
strongly undulated as they cross the ridges and depressions of the posterior
slope.

A specimen of normal form has a length of 14 mm. and a height of 8 mm.

This is a comparatively rare form, and is most nearly allied to P. emarginata,
but differs in the characters of the posterior slope ; that species having a single
very deep sulcus, while this one has two shallower sulci, the upper one extend-
ing nearly to the cardinal line.

Formation and locality. In the Chemung group, near Elmira, N. Y.

Pal^oneilo elongata.

PLATE XLVm, FIG. 39 ; AND PLATE XCIII, FIG. 11 a.
PakBoneilu elongata, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations ; PI. 48, fig. 39. 1883.

Shell small, very elongate-ovate, attenuate posteriorly; length twice the
height ; basal margin regularly and gently convex, curving abruptly upward
at the anterior end. Posterior extremity abruptly rounded or sub-truncate.
Cardinal margin arcuate, anterior end regularly rounded.

Valves depressed-convex below and posteriorly, more convex above the
middle in the anterior and umbonal regions.

Beaks situated behind the anterior third, small, not prominent. Umbonal

ridge undefined.

Surface marked by very fine, even, slightly undulating concentric striae.

Interior unknown.

Three specimens measure respectively 16, 14 and 13 mm. in length, and

7, 7 and 6.5 mm. in height.

346 PALEONTOLOGY OF NEW YORK.

This species resembles P. atlenuata, but shows no constriction of the basal
margin, and the beaks are more nearly central.

Formation and localities. In the shales of the Chemung group, at Philipsburgh,
Alleghany county, N. Y., and at Warren, Pa.

PALiEONEILO ATTENUATA.

PLATE L, FIGS. M-89.

PalcBoneilo attenuata. Hall. Prelim. Notice Lamellibranchiata, 2, p. 12. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 50, figs. 34-39. 1883.

Shell above the medium size, ovate-lanceolate in outline ; length twice the
height ; basal margin gently curved in the anterior and posterior portions,
and sinuate a little behind the middle. Posterior extremity narrowly
rounded. Cardinal line gently arcuate, declining posteriorly. Anterior end
regularly rounded.

Valves in the posterior part, depressed-convex, with a shallow depression
in the middle ; the anterior portion is more convex, becoming gibbous in the
middle and above.

Beaks a little in advance of the anterior third, small, little elevated above
the hinge. Umbonal slope rounded, scarcely defined.

Test thin, marked by fine, closeJy-arranged striae of growth, with stronger
fascicles, at irregular intervals, which remain, in some degree, impressed upon
the cast.

The characters of the interior are shown in figs. 35 and 36 of plate 1.

Three specimens measure respectively 20, 31 and 42 mm. in length, and
10, 15 and 19 mm. in height.

This species is readily distinguished by the elongate form, depressed-convex
valves, and absence of the umbonal ridge and furrow. The only species with
which it can be compared is P. elongata of the Chemung group.

Formation and localities. In the Waverly sandstone, at Granville and Newark,
Licking county, 0.

LAMELLIBRANCHIATA. 347

PaLjEONEILO truncata.

plate l, figs. 40, 41.

Palaoneilo truncata. Hall. Pal. N. Y., vol. v, pt. 1. Plates ami Explanations: PI. 50, figs. 40, 41. 1883.

Shell of medium size, trapezoidal; length about twice the height; basal
margin nearly straight or slightly concave in the middle ; posterior margin
retrally truncate, acutely rounded above into the cardinal line, which is very
slightly arcuate. Anterior end rounded.

Valves convex below, becoming gibbous in the middle and upper part.

Beaks at about the anterior fourth, somewhat prominent, rising above the
hinge-line. Umbonal ridge broad, distinct. Post-cardinal slope depressed,
marked above by an undefined elevation near the hinge-line.

Test thick, marked by fine, closely-arranged, concentric striae, which in
some parts are crowded and fasciculate, but which do not rise into regular
lamellar expansions. Interior unknown.

The two specimens described measure respectively 30 and 24 mm. in
length, and 15 and 12 mm. in height.

This species may be compared with P. muta, but it is a proportionally longer
shell, the basal and cardinal margins are nearly parallel, the beaks are more
anterior, and the shell surface is not raised in regular lamellar expansions.

Formation and localities. In the sandstones of the Waverly group, at Rich-
field and Medina, 0.

Palaoneilo sulcatina.

PLATE I,, FIGS. 4-2-16.

Nueulites gtdcatina, Co.«ir.\d. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 250, pi. 15, fig. 10. 1842.
Leda nuculif<rrmis, Stevkns. Am. Jour. Sci., series 2, vol. xxv, p. 262. 1858.

" Barrlti, Whitk ami Whitfield. Proc. Boston Soc. Nat. Hist., vol. viii, p. 298. 1862.
PcUwmeilo liarrini (Whitk and Whitkikld), Hall. Prelim. Notice Lamellibranchiata, 2, p. 11. 1870.
« .. X " " Pal. N. Y., vol. V? pt. 1. Plates and Explanations :

PI. 50, figs. 42-46. 1883.
NuciUa HiMmrdi, Winchbll. Proc. Acad. Nat. Sci., Phila. 1862.

Shell of medium size or larger, sub-elliptical or narrowly ovate ; length nearly
twice the height; basal margin regularly curving. Posterior extremity
narrowly rounded, with sometimes an obscure retral truncation. Cardinal
line gently arcuate. Anterior end regularly rounded.

348 PALEONTOLOGY OF NEW YORK.

Valves convex posteriorly and below, becoming gibbous in the middle and
upper portion.

Beaks at about the anterior third, prominent, rising but little above
the hinge-line. Umbonal region regularly convex. Umbonal slope convex
or sometimes flattened, giving an obscure truncation to the posterior
extremity. (Fig. 43 exaggerates this feature, which is more properly shown
in fig. 44.)

Test thin, marked by fine, close, concentric striaB with sharp lamellose
elevations at irregular intervals. The characters of the interior are shown
in figs. 45 and 46 of plate 1.

Three specimens measure respectively 35, 30 and 22 mm. in length, and
18, 16 and 12 mm. in height.

This species is more symmetrically ovate and gibbous than any of the pre-
ceding forms. It is easily distinguished from P. attenuata, with which it is
associated, by its shorter and more gibbous form and absence of mesial con-
striction.

Its mode of occurrence at Hillsdale, Mich., is in the condition of casts, which
preserve some impressions of the finer strisB, while the place of the stronger
lamellae is marked by narrow, concentric sulci, suggesting the name given by

Mr. CONEAD.

A comparison with the type specimens of Leda nuculiformis, Stevens, leaves no
doubt of its identity with the species originally described by Mr. Conrad as
Nuculites sulcatina.

Formation and localities. In the Waverly sandstone at Richfield and Newark,
0. ; also occurring at Battle Creek, and abundantly at Hillsdale, Mich.

Pal^oneilo ? DOBiA, n. sp.

PLATE XCIII, FIG. 15.

Shell large, elongate-ovate ; length and height as five to three ; basal margin
regularly curving for more than the anterior half of its length, slightly sinuate
to the posterior extremity, which is narrowly rounded. Anterior end short,
contracted beneath the beak and rounded below.

LAMELLIBRANCHIATA. 349

Valves convex below, rising rather abruptly to the middle where they are
gibbous or ventricose.

Beaks sub-anterior, prominent and incurved. Umbonal slope regularly
rounded, and the convexity is continued to the posterior extremity. Below
the umbonal slope is a broad constriction occupying one-third of the length
of the shell.

Surface marked by fine concentric striae, and on the anterior and basal
portions by strong concentric undulations.

The specimen described has a length of 56 mm. and a height of 34 mm.

This form is larger than any other known species of the genus. The con-
striction near the posterior end is broader than, in any other. Its absolute
identity with Palseoneilo has not been determined.

Formation and locality. In the Corniferous limestone, at Delaware, Ohio.

MACRODON, Lycett. 1845.
Macrodon Hamiltoni^.

PLATE LI, FIGS. 1-7, 9, 10.

Macrodon Hamiltonite, Hall. Prelim. Notice Lamellibranchiata, 2, p. 13. 1870.

» <• •' Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 51, figs. 1-10 (fig.

8 in en-or). 1883.

Shell of medium size or larger, sub-elliptical or sub-ovate, wider behind ; length
about twice the height; basal margin broadly curving, sometimes nearly
straight in the anterior portion. Posterior extremity broadly rounded, some-
times sub-truncate in the upper half Cardinal line essentially straight,
obtusely sub-angular at both extremities. Anterior end abruptly rounded or

sub-truncate.

Valves convex in the posterior portion and gibbous in the anterior and

umbonal portions.

Beaks sub-anterior, prominent, rising above the hinge-line. Umbonal

region regularly gibbous.

Surface marked by regular, sub-equidistant, lamellose, concentric lines and
by fine radiating strise, which are usually interrupted at the edges of the
45

350 PALEONTOLOGY OF NEW YORK.

lamellae and become thickened at their lower extension. The radii are
stronger on the posterior part of the shell.

The hinge structure has the usual characteristics of the genus.

Four specimens measure respectively 35, 33, 23 and 21 mm. in length, and
21, 16, 13 and 10.5 mm. in height.

This species differs from M. Chemungensis in its wider posterior end, the
absence of a constriction in the basal margin, more ovate form and the regular
concentric varices.

Formations and localities. This species occurs in the Hamilton group in most
of the localities from Schoharie county to the centre of the State, but it is not
very abundant. The greater number have been obtained in Onondaga county
and at Canandaigua and Seneca lakes, N. Y. It has been observed in collec-
tions from the Hamilton group, near Cumberland, Md. A form undistinguish-
able from this species occurs in the soft shales at Bedford, Cuyahoga county, 0.

Macrodon Chemungensis.

PLATE LI, FIGS. 11-16.

Macrodon Cheinungenxix, Hall. Prelim. Notice Lamellibranchiata, 2, p. 14. 1870.

" " " Pal. N. v., vol. V, pt. 1. Plates and Explanations: PI. 51, figs. 11-16.

1883.

Shell of medium size or larger, arcaeforra ; cardinal and basal margins sub-
parallel ; length more or less than twice the height ; basal margin nearly
straight or gently curving with a slight constriction anterior to the middle.
Posterior end broad, sub-truncate or sometimes rounded. Cardinal margin
straight, extremities angular. Anterior end rounded below, truncate above.

Valves convex in the posterior portion, becoming gibbous in the middle
and anterior.

Beaks sub-anterior, prominent, rising a little above the hinge-line.

Umbonal region gibbous, with a prominent, undefined ridge extending
toward the post-inferior extremity, and a vertical depression extending from
the umbo to the base.

Surface marked by irregular, concentric, lamellose lines of growth.

LAMELLIBRANCHIATA. 351

Three specimens measure respectively 31, 27 and 22 mm. in length, and
14, 15 and 10 mm. in height.

This species is distinguished by its parallel basal and cardinal margins, the
truncated posterior end and its narrow form. It resembles M. parvus (White
and Whitfield), of the yellow sandstone of Burlington, Iowa, but it is a much
larger form and the beaks are more anterior.

Formation and localities. In the Chemung group, at Buck's quarry, near
Elmira, at Philipsburgh, Rockville, Chemung creek and Leon, N. Y. ; also at

Meadville, Pa.

Macrodon ovatus.

PLATE LI, FIG. 8 ; AND PLATE XCIII, FIG. 16.
Macrodon ovatus. Hall. Prelim. Notice Lamellibranchiata, 2, p. 15. 1870.

Shell small, ovate, wider behind ; length once and a half the height ; basal
margin gently curving with a slight constriction anterior to the middle ;
posterior margin regularly rounded below and obliquely truncate above.
Cardinal line very gently arcuate. Anterior end short and narrowly rounded.

Valves convex, very gibbous above the middle and in the umbonal region.

Beaks sub-anterior, prominent, rising a little above the hinge-line.
Umbonal region gibbous with sometimes an undefined ridge extending
obliquely backward to the basal margin, anterior to which is a gentle con-
striction, (too strongly represented in the figure).

Surface marked by concentric lines of growth, which appear to have
been lamellose; there is no evidence of radiating stride in the specimens
examined.

Anterior hinge-teeth minute, oblique; posterior teeth elongate, very
slightly curved, one long and one short in each valve.

Three specimens measure respectively 18.5, 15 and 15 mm. in length, and
12, 19 and 9 mm. in height.

This species differs from M. Hamiltonia in its shorter form, gently curving
hinge, apparent absence of radiating striae, and in not having the regular con-
centric varices of that species.

Formation and localities. In the Waverly sandstones, at Granville and New-
ark, O.

352 PAI.JEONTOLOGY OF NEW YORK.

PTYCHODESMA, Hall and Whitfield. 1872.
Ptychodesma Knappianum.

IM.ATE 1,1, FIUS. 22-27.

Ptydiode»ua KiiaypiaHum, Halt, and Whitfikld. Twenty-foui-th Ann. Rep. N. Y. State Mns. Nat. Hist.,

I>. 192. 1872.
" " " " Pal. N. y., vol. V, pt. 1. Plates and Explanations: PI.

51, figs. 22-27. 1883.

Shell obliquely sub-ovate ; length usually more than one-third greater than the
height ; basal margin oblique, often nearly straight in the middle of its length.
Posterior end broadly rounded. Cardinal line straight, oblique, having a
length posterior to the beaks of about one-half the length of the shell.
Anterior end very short, curving downward into the basal margin without
limitation.

Valves convex in the lower and posterior portions, gibbous in the middle
and above.

Beaks sub-anterior, small, distant, closely incurved, rising but little above
the hinge-line. Umbonal slope presenting an undefined ridge, which merges
into the general convexity of the shell about the middle of its length.

Test thick, marked by fine concentric striae, with distant imbricating
lamellae. The anterior and basal margins are thickened and present the
edges of numerous lamellae of growth.

Ligamental area deeply excavated, marked by numerous longitudinal
striae, which are abruptly arched just beneath the beak. Hinge with two
or more cardinal teeth. Anterior muscular impression strong.

Three specimens measure respectively 43, 38 and 35 mm. in length, and
28, 28 and 27 mm. in height.

This shell bears some resemblance externally to several forms of Modiomorpha
and Nyassa, but the deeply grooved ligamental area is a distinctive feature.

Formation and localities. In the cherty layers of the age of the Hamilton
group, from the Falls of the Ohio, and Dublin, Ohio. A form of this genus
occurs in the Hamilton group, in the State of New York, at several localities;

LAMELLIBRANCHIATA. 353

but the material at hand is too obscure to warrant its separation as a distinct
species.

Ptychodesma minor.

PLATE XLI, FIG. 27.
PlyclwXenmai vUiwr, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations; PI. 41, fig-. 27. 18S3.

Shell small, sub-ovate ; length about one-third greater than the height; basal
margin regularly rounded. Posterior extremity somewhat abruptly rounded,
and extended in the middle. Cardinal line short, oblique. Anterior end
short, regularly rounded below the beaks.

Valves regularly convex in the basal and posterior portions, gibbous in the
middle and in the umbonal region.

Beaks anterior, jjrominent, incurved. An undefined sub-angular umbonal
ridge extends to the post-inferior extremity of the shell.

Surface marked by fine concentric striae. Interior unknown.

The specimen figured has a length of 16.5 mm., and a height of 11 mm.

This species is distinguished by the slight obliquity of the body of the shell
to the hinge-line, the extension of the shell in the middle of the posterior mar-
gin, the forward direction of the beaks, and the strong umbonal ridge.

Formation and locaWy. In the shales of the Chemung group, near Elmira, N. Y.

Ptychodesma nanum, n. sp.

PLATE XCIII, FIGS. 17, 18.

Shell small, broad-ovate; length about one-fourth greater than the height;
basal margin broadly rounded posteriorly, with a sinus toward the anterior
end. Posterior extremity regularly and broadly rounded, recurving to the
cardinal line. Cardinal line short, oblique. Anterior end short and abruptly
rounded below the beak.

Valves moderately convex in the posterior and lower part, becoming gib-
bous in the umbonal region.

Beaks anterior, directed upward, rising but little above the hinge-line.
Umbonal slope rounded.

354 PALAEONTOLOGY OF NEW YORK.

Surface marked by fine, regular, concentric striae. Interior unknown.
Three specimens measure respectively 10, 15 and 16 mm. in length, and
8, 11 and 12 mm. in height.

This species resembles P. Knappianum in form, but has a much more distinct
sinus in the anterior portion of the valves, and so far as observed has main-
tained its small size, never exceeding 16 mm. in length in a collection of more
than thirty specimens.

Formation and locality. In the lower part of the Chemung group, at Ithaca, N. Y .

NY ASS A, Hall. 1870.
Nyassa arguta.

PLATE LIII, FIGS. 7-20.

Nyassa arffuta. Hall. Prelim. Notice Lamellibranchiata, 2, p. 28. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates ami Kxplanations : PI. 53, figs. 9-20. 1883.

Shell of medium to large size, elongate sub-elliptical or ovate-arcuate ; length
about twice the height ; basal margin nearly straight, often slightly arcuate
or contracted posterior to the middle, abruptly recurved at the post-inferior
extremity ; posterior margin curved or obliquely sub-truncate. Cardinal line
gently arcuate. Anterior end narrowed and abruptly rounded.

Valves depressed below, gibbous above and in the umbonal region.

Beaks sub-anterior, small, closely appressed, rising but little above the
hinge-line. Umbonal ridge prominent, rounded or sub-angular, arcuate,
extending to the post-inferior extremity ; below and parallel with the ridge
there is a flattening or depression of the shell extending from the beaks and
producing a constriction or sinuosity in the basal margin.

Test thick, marked by lamellose concentric lines of growth, without other
ornamentation.

The hinge is characterized by numerous small teeth or callosities beneath
the beak, which appear to be without special arrangement, the posterior ones
being directed backward and sometimes more elongated. Lateral teeth
two or three in number, parallel and extending nearly to the post-cardinal

LAMELLIBRANCHIATA. 355

extremity. Anterior muscular impression deep and strong. Pallial line sim-
ple, often strongly marked in the anterior part of the shell. Posterior mus-
cular impression situated on the cardinal slope, not strongly marked. Liga-
ment narrow, external.

Five specimens measure respectively 21, 28, 45, 47 and 52 mm. in length,
and 11, 16, 22.5, 24 and 24.5 mm. in height.

This species is distinguished from N. recta by its arcuate, sub-elliptical form,
sinuate basal margin, and larger size.

Formation and localities. In the arenaceous shales of the Hamilton group, in
Schoharie, Otsego, Madison and Onondaga counties, and abundant in some cal-
careous layers of the group at Pratt's falls, in Onondaga county, N. Y.

Nyassa subalata.

PLATE LUI, FIGS. 21-26.

Nyassa subalata. Hall. Prelim. Notice Lamellibranchiata, 2, p. 29. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations; PI. 53, fig.s. 21-26. 1883.

Shell of medium size or larger; body broadly sub-ovate, and including the
alation, rhoinboidal in outline; length one-third greater than the height;
basal margin regularly rounded and sometimes nearly straight in the middle,
abruptly recurving at the post-inferior extremity; posterior end oblique,
broadly truncate, with the margin slightly convex. Cardinal line oblique,
usually alate posteriorly. Anterior end short, narrowed and regularly rounded
below the beak.

Valves moderately convex below, becoming gibbous above and in the
umbonal region.

Beaks sub-anterior, small, appressed, rising but little above the hinge-line.
Umbonal ridge rounded, undefined, merging into the general convexity of
the shell before reaching the post-inferior extremity.

Test thick anteriorly, marked by fine, irregular, concentric strioa which
are often raised into strong fascicles along the basal and posterior margins.
A single young individual shows distinct, continuous, distant radii on the

356 PALEONTOLOGY OF NEW YORK.

posterior slope reaching to the posterior margin. This feature is also
obscurely shown on several of the older individuals (erroneously represented
in fig. 21).

Cardinal teeth not determined. One or two lateral teeth are present on
the cardinal alation, extending nearly to the posterior extremity. Anterior
muscular impression strong.

Five characteristic specimens measure respectively 23, 36, 38, 39 and 41
mm. in length, and 16, 24, 25, 27 and 28 mm. in height.

This species is readily distinguished from the known species of the genus by
its short, broad form and alate post-cardinal extension.

Formation and localities. In the shales of the Hamilton group, at Fultonham
and Summit, Schoharie county, N. Y.

Nyassa recta.

PLATE LIU, FIGS. 1-6.

Nyassa recta. Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 29. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 53, figs. 1-8. 1883.

Shell small or of medium size, ovate sub-cuneate ; length nearly twice the
height ; basal and cardinal margins sub-parallel ; basal margin gently curv-
ing or often nearly straight, abruptly recurved at the post-inferior angle and
more gently curving at the anterior end. Posterior extremity obliquely
truncate. Cardinal line straight or slightly arching, and declining toward
the posterior end. Anterior end short, narrowed and regularly rounded
below the beaks.

Valves regularly convex in the lower part, gibbous above and in the
umbonal region.

Beaks sub-anterior, prominent, rising above the hinge-line. Umbonal
ridge direct to the post-inferior extremity, with usually a slight flattening or
depression in the shell below the ridge, which extends from the umbo to the
base, scarcely constricting the margin.

LAMELLIBRANCHIATA. 357

Surface marked by fine, closely arranged, concentric striae, which become
crowded and fascicled at irregular distances.

.Anterior muscular impression strongly marked, situated close within the
anterior margin of the shell. The posterior extension of the cardinal line is
marked by two distinct lateral teeth.

Four specimens measure respectively 20, 21, 24 and 28 mm. in length, and
10, 11, 12 and 15 mm. in height.

This species is distinguished from N. arguta in its smaller size ; by its
straight hinge-line, more prominent beaks, the direct umbonal ridge and the
absence* of distinct constriction in the basal margin.

Formation and localities. In the softer shales and also the arenaceous beds of
the Hamilton group, near Fultonham and Summit, Schoharie county, N. Y.

Nyassa elliptica.

TLATE XXXIV, FIG. 8.

Nyassa elliptica. Hall. Prelim. Notice Lamellibranchiata, 2, p. 30. 1S70.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 34, fig. 8. 1883.

Shell of medium size, broadly elliptical in outline ; length and height as 7 to
4; basal margin regularly curving; posterior extremity regularly rounded.
Cardinal line gently arcuate from the beaks to the posterior extremity.
Anterior end short, regularly rounded below the beak.

Posterior and basal portions of the shell gently convex, becoming more
convex above and morterately gibbous in the umbonal region.

Beaks sub-anterior, appressed, rising but little above the hinge-line.
Umbonal slope marked by an undefined rounded ridge which extends toward
the post-inferior extremity, but merges into the general convexity a little
beyond the middle ; sometimes a slight depression below the umbonal ridge,
extending half way to the post-inferior extremity.

Test of moderate thickness, marked by fine concentric striae of growth.
The specimen is a cast of the interior, preserving a small portion of the shell.

Anterior muscular impression strong, situated just within the border of
46

358 PALEONTOLOGY OF NEW YORK.

the shell. Some portions of the shell preserved along the cardinal line give
indications of one or more lateral folds or teeth.

The specimen described has a length of 35 mm. and a height of 20 mm.

This species differs from all the others here described in its regular elliptical
form. Although its identity with Nyassa is not fully established, there seems
no sufficient reason to doubt its relations to this genus.

Formation and locality. In the Corniferous limestone, at Stafford, Genesee
county, N. Y.

GRAMMYSIA, De Verneuil. 1847.

a. cingulata.

Grammysia ovata, n. sp.

PLATE XCIII, FIG. 22.

Shell of medium size, ovate ; length about one-third greater than the height ;
basal margin broadly curving with a slight constriction near the middle.
Posterior extremity abruptly recurved from the base and obliquely sub-
truncate above. Cardinal line nearly straight, slightly declining posteriorly.
Anterior end short, regularly rounded below the lunule.

Valves regularly convex in the lower and posterior portions, gibbous in
the middle and above.

Beaks sub-anterior, moderately prominent. Cincture shallow, distinctly
defined above, extending from the beak obliquely to the basal margin, at
about the middle of its length. Umbonal slope sub-angular, continuing to
the post-inferior extremity.

Surface marked by fine concentric striae, which on the anterior and umbonal
portions are fasciculate, rising into sub-angular folds or ridges. Interior
unknown.

The specimen described has a length of 60 mm. and a height of 38 mm.

This species bears some resemblance to G. bisulcata, but is a proportionally
longer shell, the cincture is shallower, and there are no accompanying folds or

LAMELLIBRANCHIATA. 359

plications. In its general form it also somewhat resembles G. Canadensis of
Billings, but is otherwise very distinct.

Formation and locality. In the Corniferous limestone, Delaware, 0.

Gkammysia bisulcata.

PLATE LIV, FIGS. 1-16; PLATE LVI, FIG. 1 ; and PLATE XCIII, FIG. 25.

Pholadomya anmnala, Goldpuss. Pet. Germ., p. 272, pi. 157, fi^. 9. 1834-1840.

Ptennea bisulcata, Cokrad. Geol. Surv. N. Y., Ann. Rep., p. 116. 1838.

Cypricardites bisulcata, Conrad. Geol. Surv. N. Y., Ann. Rep., p. 52. 1841.

Qrammysia Hamiltoiumgis, Db Vkrneuil. Bull. Soc. Geol., France, 2d ser., vol. iv, p. 096. 1847.

Cardinia Hamillonensis, D'Orbigny. Prod. Paleon., vol. 1, p. 76. 1850.

Qrammysia bisulcata (Cokrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 49. 1870.

PS'l- N. Y., vol. V, pt. 1. Plates and Explanations : PI. 54, figs 1-
16 ; pi. 56, fig. 1. 1883.
Compare Nucida cingulata, Hisikger. Leth. Svecica, pi. 39, fig-. 1 ; supplement, p. 6. 1837.

Shell large, ovoid ; length once and a half the height ; basal margin broadly
curved, with a constriction near the middle of its length ; posterior margin
abruptly rounded below and broadly curving or sub-truncate above. Cardi-
nal line nearly straight, more than half as long as the shell. Anterior end
abruptly rounded below the deep lunule.

Valves regularly convex below and gibbous or ventricose in the middle
and above.

Beaks sub-anterior, strong, incurved over the cardinal line. Umbo promi-
nent, gibbous, with a cincture consisting of a strong fold with a furrow on
each side, extending from the beak to the basal margin at about the middle
of its length ; this feature, alternating on the two sides, gives a sinuosity to
the line of junction of the valves.

Entire surface marked by fine concentric striae, which, on some portions ol
the shell, are aggregated into fascicles ; and by strong, regular, persistent,
concentric ridges or folds, which are stronger upon the anterior part of the
shell and distinctly undulated in crossing the cincture. The undulations occa-
sionally become obsolete in the lower and posterior part of the shell, and
sometimes are to be seen only on the anterior and umbonal portion. In well-
preserved specimens the surface, especially in the umbonal region, is also

360 PALEONTOLOGY OF NEW YORK.

marked by very fine, radiating, granulose striae which may be more or less
interrupted by the concentric undulations.

Ligamental area deep and strong. Anterior muscular impression sub-cir-
cular, placed just within the anterior margin. Posterior scar large and shal-
low, situated about one-third the length of the sliell from the posterior
extremity. Pallial line simple.

Four characteristic specimens measure respectively 52, 53, 57 and 75 mm.
in length, and 38, 35, 34 and 50 mm. in height. ' A specimen preserving its
normal form and proportions has a length of 70 mm., height 45 mm., and a
depth to both valves of 37 mm.

In well-preserved specimens, this species is distinguished by the strong cinc-
ture with parallel furrows extending to the base. It differs from G. elliptica in
its more elongate form, less elevated and incurved beaks, less prominent umbo
and greater development of the concentric undulations.

Formation and localities. In the arenaceous shales of the Hamilton group, in
Schoharie, Otsego, Madison and Onondaga counties, and rarely in the softer
beds of the group in Ontario aud other counties in the western part of the State.

Grammysia nodocostata.

PLATE LV, FIGS. 1-11; PLATE LVI, FIGS. (2, 3?) ; and PLATE LVII, FIGS. 7, 8.

Qrammysia nodocostata. Hall. Pi-elim. Notice Lamellibranchiata, 2, j) 50. 1870.

" " Pill N. Y., vol. V, pt. 1. Plates and Explanations: PI. 55, ti^. 1-11. 1883.

Shkll varying from medium size to veryhirge; obliquely sub-ovoid; length
about one-third greater than the height; basal margin broadly curving,
flattened or constricted near the middle ; posterior margin abruptly rounded
below, and obliquely truncate above. Cardinal line straight, bordered by a
well-defined escutcheon. Anterior end abruptly rounded below the lunule.

Valves regularly convex below and in the posterior portion, becoming
gibbous or ventricose above and in the umbonal region. Often extremely
gibbous from vertical compression.

Beaks sub-anterior, prominent and strongly incurved. Owing to pressure
they often project beyond the anterior end. Umbo, in its upper portion.

LAMELLIBRANCHIATA. 361

marked by several radiating nodose ridges with intermediate sulci, which, with
the exception of a single strong ridge and furrow, become obsolete before
reaching the middle of the shell, while the remaining furrow and ridge
extend to the base and constrict the margin. The ridge is developed in the
right valve, and carries the majority of the nodose radii anterior to it. The
deepest furrow is developed in the left valve, and carries the principal part
of the nodose radii posterior to it. This feature makes the shell somewhat
inequi valve.

Entire surface marked by fine, crowded, concentric striae, which at some-
what regular intervals are fasciculate and elevated into strong angular ridges
or undulations. In the region of the cincture these are crossed and inter-
rupted by radiating ridges extending from the beak, and are more
developed in the young shells, and become obsolete below the middle in
old shells. Surface also marked by fine radiating pustulose striae, as shown
in fig. 11 of plate Iv, but which are more continuous than represented in the
figure. Anterior muscular impression sub-circular, situated just within the
anterior border of the shell.

Two specimens measure respectively 50 and 80 mm. in length, and 32 and
55 mm. in height. Several large individuals have lengths of about 100
mm. each.

This species resembles G. bisulcata, and has generally been confounded with
it, but is more oblique, with a shorter hinge-line ; the lunule in front of the
beaks is smaller ; the concentric folds finer and more numerous, besides being
angular, lamellose and fasciculate, with a greater number of interstitial ones.
The most conspicuous difference is in the oblique folds of the umbo, which
become nodose at their intersection with the concentric folds.

The typical forms of this species are very easily distinguished, but in the
older shells the characteristic features often become obsolete, and the shells
being distorted by pressure are not so easily separable from other species.

Formation and localities. In the shales of the Hamilton group, near Sherburne,
Chenango county; Hamilton, in Madison county; Pratt's falls, Onondaga
county, and on the shores of Cayuga lake, N. Y.

362 PALAEONTOLOGY OF NEW YORK.

Grammysia magna.

PLATE LVI, FIGS. 4-7 ; AND PLATE LVII, FIG. 9.

Omiainytia inagiia. Hall. Prelim. Notice Lamellibranchiata, 2, p. 50. 1870.

In part " " " Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 56, figs. 2-8; jil. 57,

fife's. 7-10. 1883.

Shell large, broadly ovate or sub-rhomboidal ; length more than one-third
greater than the height; basal margin gently curving except near the
middle, where it is constricted ; post-basal extremity abruptly rounded, with
the margin sub-truncate above. Cardinal line straight, extending more than
half the length of the shell, declining posteriorly. Anterior end short and
abruptly rounded below the lunule.

Valves regularly convex on the basal and posterior portion, becoming gib-
bous in the middle and above.

Beaks sub-anterior, large, prominent and incurved. Cincture in the right
valve, a distinct ridge, margined by a depression posterior to it ; in the left
valve there is a corresponding depression.

Surface marked by fine concentric striae, which become fasciculate, pro-
ducing folds or undulations which are conspicuous on the anterior and umbo-
nal portion of the shell, and usually obsolete on the posterior portion. The
concentric undulations in crossing the ridge near the beak appear like trans-
verse nodes. Well-preserved specimens show fine radiating striae crossing
the surface, especially in the upper portion. Interior essentially unknown.

Four specimens measure respectively 72, 82, 98 and 100 mm. in length,
and 45, 48, 65 and 65 mm. in height.

This is one of the large forms of the genus, and is closely allied to G. nodo-
costata, from which it differs principally in the form and structure of the oblique
cincture, which is a simple fold on the right valve and a furrow on the left, and
never divided into nodose ridges or accompanied by lines of nodes on the sides,
as in that one. The oblique furrow is often exaggerated by the crushing of
the shell, the folding taking place along that line.

Notwithstanding these differences, which are sufficiently well marked in

LAMELLIBRANCHIATA. 363

many individuals, it may be suggested that these are only old shells in which
the conspicuous markings have become obsolete. An approach to this condi-
tion is seen in fig. 8 of plate Ivii, which is referred to G. nodocostata.

Formations and localities. In the arenaceous shales of the Hamilton group, in
Schoharie, Otsego, Chenango, Madison and Onondaga counties, and in the Che-
mung group at Ithaca, N. Y.

Grammtsia erecta.

PLATE LVI, FIG. 8 ; AND PLATE LVII, FIG. 10.

Qrammyxia erecta. Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 52. 1870.

" magna. Hall, in error. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 56, fig. 8 ; pi.

57, tig-. 10. 1883.

Shell of medium or large size, erect, sub-triangular ; length one-fourth greater
than the height ; basal margin gently rounded except where slightly sinuated
by the cincture near the middle of its length ; posterior margin abruptly
rounded below and recurving to the cardinal line, which is short. Anterior
end below the lunule, broadly rounded.

Valves regularly convex below and gibbous above.

Beaks sub-anterior, very prominent and strongly incurved. Umbo ven-
tricose ; umbonal slope rounded and arcuate. Cincture in the right valve,
consisting of a fold and shallow furrow on each side, beginning at the beak,
and extending in a curving direction to near the middle of the base.

Surface marked by fine concentric striae, which become fasciculate on the
anterior half of the shell, and form strong angular elevations. These con-
centric undulations extend over the entire umbonal region, and are abruptly
sinuate in passing the cincture. Surface also marked by extremely fine
riuliating striae.

This species differs from any of those having a cincture, in its erect form and
sub-triangular outline. The specimens are distorted and fragmentary, and
therefore unsatisfactory.

Formation and locality. In the shales of the Hamilton group, at Fultonham,
Schoharie county, N. Y.

364 PALEONTOLOGY OF NEW YORK.

GrAMMYSIA CIRCULARI8.

PLATE LVII, FIU8. 3-« ; ANU I'l.ATE LVIII, VUi. 13.

Qrannnysia circnlarU, Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 51. 1870.

" " " Pal. N. y., vol. V, i)t. 1. Plates and Explanatioii.s : PI. 57, figs. 3-G; pi. 58,

fijf. 13. 18S3.

Shell from medium to large size, sub-circular in outline, ventricose ; length
about one-fifth greater than the height; basal margin regularly rounded,
except a slight sinuosity posterior to the middle ; posterior margin regularly
rounded from the post-inferior extremity to the cardinal line. Cardinal line
short and arcuate. Anterior end short and narrow, regularly curving from
the lunule into the basal margin.

Valves regularly convex along the lower portion, becoming gibbous and
ventricose above and in the umbonal region.

Beaks sub-anterior, prominent and strongly incurved. The beak and
umbo marked by a cincture, consisting of a ridge and shallow furrows, which
becomes somewhat obsolete on the middle of the valve, but is continued to
the basal margin, marking the shell in its passage by an undulation in the
striae which produces a slight projection in the centre, with a shallow con-
striction posterior to it. These features alternate in the two valves.

Surface marked by fine concentric striae, which become fasciculate toward
• the base and on the anterior end, forming distinct ridges or undulations of
the surface. No radiating striae have been observed.

The hinge, as shown in tigs. 5 and 6 of plate Ivii, has a strongly marked
ligamentnl area extending half the length of the shell, and a well-defined
lunule. Figs. 3 .and 4 show the anterior muscular impression just within the
anterior border and encroaching upon the lunule. The pallial line continues
parallel to the basal margin, recurving abruptly and terminating in the large
posterior muscular scar on the post-cardinal slope. The course of the pallial
line, in the cast, is marked by regular, elongate, pustulose striae, extending
from above and terminating in that line. The interpallial area is marked by
numerous elongate pustules.

Three specimens measure respectively 67, 70 and 87 mm. in length, and

LAMELLIBRANCHIATA. 365

55, 59 and 70 mm. in height. A specimen preserving both valves has a
length of 53 mm., height 42 mm., and a depth to both valves of 32 mm.

This species is readily distinguished from any of its associated forms by its
sub-circular outline, in which character it seldom varies; and also in the absence
of a distinct cincture below the middle of the valve.

Formations and localities. In the Hamilton group, in Albany, Schoharie and
Madison counties; in the Chemung group, at Nichols, in Tioga county, Cort-
land, Cortland county, and Ithaca, Tompkins county, N. Y.

Grammysia elliptica.

PLATE LVllI, FIGS. 1-12 (1, 6, 6?).

Oramiaysia elliptica. Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 53. 1870.

" Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. ."58, figs. 1-1-2. 18S3.

Shell of medium or large size, transversely elliptical ; length varying from
one-sixth to one-third greater than the height ; basal margin broadly curving,
slightly sinuate about the middle ; posterior margin abruptly rounded below
and curving into the cardinal line above, sometimes more or less truncate.
Cardinal line arcuate. Anterior end narrow and abruptly rounded below
the lunule.

Valves regularly convex below, becoming more or less gibbous above the
middle and in the umbonal region.

Beaks sub-anterior, very prominent, strongly incurved, rising considerably
above the hinge-line. Umbonal slope rounded, arcuate. Cincture consist-
ing of a fold and furrow, extending downward in a curving direction to
the base of the shell, producing a gentle sinuosity in the basal margin. The
fold is more strongly developed in the left valve and the furrow in the

right one.

Test thick, marked on the posterior and middle portions of the shell by
fine, irregular, concentric striae, which become aggregated into fascicles on the
middle of the shell ; and on the anterior part marked by strong concentric
undulations. No radiating striae have been observed.
47

366 PALMONTOLOGY OF NEW YORK.

The hinge of the right valve shows a thickened phite bearing a single
angular fold just beneath the beak. Nothing is satisfactorily known about
the muscular impressions.

Four specimens measure respectively 31, 57, 65 and 93 mm. in length, and
23, 36, 46 and 63 mm. in height.

This species more nearly resembles G. circularis than any other form of the
Hamilton and Chemung groups, but it is usually more elliptical in outline and
the umbonal ridge is stronger and more distinctly defined. In G. elliptica the
cincture is usually well defined, while in G. circularis it is obscure or obsolescent.

The specimen illustrated in figs. 5 and 6 of plate Iviii has the form of G.
circularis. The cincture is exaggerated in figure 5, being very obscure in the
specimen.

Formation and localities. In the Chemung group, at Philipsburgh, Alleghany
county; near Ithaca, Tompkins county, N. Y., and near Mansfield, Tioga
county, Pa.

b. obsoleta.

Grammysia obsoleta.

plate lix, figs. 21-27.

Oraiamysia obsoleta. Hall. Prelim. Notice Lamellibranchiata, 2, ju 60. 1870. '

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 59, tigs. 21-27. 1883.

Shell large, general form broadly ovate, becoming elliptical and sub-rhomboidal
from pressure ; length more than one-third greater than the height ; basal
margin regularly rounded, frequently with a slight constriction near the mid-
dle. Posterior extremity regularly rounded, curving into the basal margin
without limitation. Cardinal line more than half the length of the shell,
arcuate, declining toward the posterior extremity. Escutcheon distinctly
limited. Anterior end short and abruptly rounded below the lunule.

Valves regularly convex below and posteriorly, becoming gibbous in the
middle and above.

Beaks sub-anterior, large, elevated, with the apices strongly incurved.

I

LAMELLIBRANCHIATA. 367

Umbonal slope rounded, with no defined limitation. There is a scarcely per-
ceptible flattening of the lower part of the shell from below the umbo to the
middle of the basal margin — a feature which is not always present. The
anterior end of the shell below the beak is marked by a shallow furrow with
a ridge on each side extending to the antero-basal margin. The posterior
ridge merges into the general convexity of the valve above.

Surface marked by fine, closely arranged, concentric striae, which are some-
times crowded and fasciculate. The umbonal region and anterior end are
sometimes marked by strong, concentric folds.

A specimen of this species has a length of 65 mm. and a height of 45 mm.
A larger individual has a length of 70 mm.

In some of its phases this species resembles individuals of G. elliptica
which have the cincture scarcely developed, as in figs. 1 and 4 of plate Iviii,
but the broadly rounded posterior extremity of the present species, the sulcate
anterior end and constant absence of a cincture are distinguishing characters.
It also sometimes assumes the general form of G. drcularis, but in that species
the flattening of the shell and the constriction of the basal margin is posterior
to the middle, and it has no anterior fold or sinus.

Formation and localities. In the arenaceous layers of the Hamilton group, in
Schoharie, Madison and Onondaga counties ; and in the soft shales of the group
on the shores of Skaneateles, Seneca and Cayuga lakes, and also near Bellona
and Moscow, N. Y.

Grammysia bellatula.

PLATE LXm, FIGS. 1-3.

Cardimaorjjka bellatula, Hall. Prelim. Notice Lamellibranchiata, 2, p. 92. 1870.

" " •' Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 63, figs. 1-3. 1883.

Shell small, ovate ; length one-third greater than the height ; basal margin
regularly curved without apparent constriction. Posterior extremity abruptly
rounded. Cardinal line straight, extending half the length of the shell.
Anterior end short, abruptly rounded below the lunule.

"Valves regularly convex below and on the posterior end, becoming gib-
bous in the middle and umbonal region.

368 PALEONTOLOGY OF NEW YORK.

Beaks in advance of the anterior third, prominent and incurved. Umbonal
slope not defined.

Surface marked by fine concentric striae and by angular, somewhat distant,
concentric folds, which become obsolete on the middle and posterior parts
of the shell. Interior unknown.

Two valves of equal size have lengths of 14 mm. and heights of 10 mm.

Formation and locality. In the shales of the Hamilton group, York, Living-
ston county, N. Y.

Grammysia Eriopia.

PLATE LXni, FIGS. 7, 8.

Cardimniirpba Eriirpla, Hall. Pi-elim. Notice Lainellibraiichiata, 2, p. 92 1870.

Pal. N. Y., vol. V, pt. 1. Plates ami Explanations : PI. 63, figs. 7, 8. 1883.

Shell above the medium size, sub-circular or very broadly ovate ; length about
one-fifth greater than the height ; basal margin regularly rounded into the
broad posterior end. Cardinal line declining toward the posterior extremity.
Anterior end short, abruptly rounded below the lunule.

Valves regularly convex below and posteriorly, gibbous in the middle
and above.

Beaks at the anterior third or fourth, prominent and strongly incurved.
Umbonal ridge merging into the general convexity of the shell. Post-
cardinal slope marked by a low ridge which may become obsolete.

Surface marked by fine concentric striae and by fine, distant, radiating
striae, principally developed on the posterior slope. Also marked by strong,
concentric folds which are principally shown on the umbo and the anterior
portion of the valve. In young shells the undulations are present on the
posterior slope, limited above by the post-cardinal ridge. Interior unknown.

A small specimen has a length of 21.5 mm. and a height of 17 mm. A
larger individual has a length of 55 mm.

This species bears some resemblance to G. obsoleta, but there is an absence
of any anterior radiating folds, the Vjeak is more erect and the concentric

LAMELLIBRANCHIATA. 369

undulations are more strongly marked. It differs from G. circularis in the
absence of any mesial cincture.

Formation and localities. In the shales of the Hamilton group, on the shores
of Canandaigua and Seneca lakes, N. Y.

Grammysia glabra, n. sp.

I'LATE XCIII, FIG. 24.

Shell of medium size, ovate ; length one-third greater than the height ; basal
margin regularly convex, with a slight constriction anterior to the middle of
its length. Posterior extremity narrowly rounded. Cardinal line arcuate,
declining posteriorly. Escutcheon narrow. Anterior end large, declining
rapidly from the beaks, and regularly rounded below the lunule.

Valves regidarly convex in the lower and posterior portions, becoming
gibbous in the middle and above.

Beaks at about the anterior third, large, much elevated above the hinge-
line. Umbonal region regularly convex. Umbonal slope rounded, not
defined. There is a slight depression extending almost vertically from the
umbo, and producing a gentle constriction in the basal margin.

Surface marked by fine, sub-equal, concentric striae, which become fascicu-
late, and often rise into low undulations on the anterior portion of the shell.
Anterior muscular impression large, situated below the limits of the lunule.
Pallial line, in the cast, marked by a row of inconspicuous nodes, following
near to the ventral margin. Posterior scar large and superficial, situated on
the post-cardinal slope.

Two specimens measure respectively 53 and 57 mm. in length, and 36 and
38 mm. in height.

This species most nearly resembles G. obsoleta, but in its natural condition it
is not so broadly ovate, and it has no indication of the fold and sinus on the
anterior end, as in that species.

Formation and localities. In the upper sandstones of the Chemung group, at
Warren, Pa., and doubtfully at Clark's farm, near Panama, N. Y.

370 PALEONTOLOGY OF NEW YORK.

c. undulata.
Grammysia alveata.

PLATE LVir, FIGS. 1,2; and PLATE LX, FIGS. 1-11.

Ptki'idtmia alveata, Conrad. Geol. Surv. N. Y., Ann. Rep., p. 53. 1841.

Orammj/xia edveata (Conrad), Hail. Prelim. Notice Lainellibranchiata, 2, p. 55. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 57, figs. 1, 2;

pi. 60, figs. 1-11. 1883.

Shell large, ovate-rhomboidal ; length more than one-third greater than the
height ; basal margin regularly curved, abruptly recurving at the post-inferior
extremity and broadly truncate above. Cardinal line short, nearly straight ;
sub-alate at the post-cardinal extremity. Anterior end short, abruptly
rounded.

Valves convex below and posteriorly, ventricose above.

Beaks sub-anterior, large, prominent, strongly incurved over the hinge-
line. Umbonal slope rounded or sub-angular, extending to the post-inferior
extremity. Cardinal slope concave. Cincture obsolete.

Entire surface marked by fine concentric striae and, anterior to the umbonal
slope, by strong, angular, concentric folds or more gentle undulations.

Hinge marked by a thickened plate bearing an obscure fold which is not
so strongly marked as in several of the preceding species.

Two specimens measure respectively 68 and 88 mm. in length, and 47 and
62 mm. in height. A specimen preserving both valves has a length of 58
mm., height 42 mm. and depth of 36 mm. Three vertically compressed indi-
viduals of large size measure respectively 84, 94 and 104 mm, in length, 34,
58 and 39 mm. in height, and 52, 66 and 57 mm. in the depth of both valves.

This species closely resembles G. Urate, and that one may be only a modifi-
cation and smaller form of this species. In general it may be distinguished by
its fewer concentric folds and their entire absence on the posterior slope. It
differs from G. arcuata in its more erect form and the absence of the concentric
folds on the posterior slope.

Formation and localities. Abundant in the arenaceous shales of the Hamilton

LAMELLIBRANCHIATA. 371

group, in Schoharie and Otsego counties, and found in nearly all localities
througiiout Eastern and Central New York, but seldom in the softer shales in
the western part of the State. It also occurs in the shales of the Hamilton
group at Patterson's creek, Va.

Grammysia lirata.

[ Probably the young of Grammysia alveata. ]

PLATE LIX, FIGS. 6-12.

Orammynia lirata. Hall. Prelim. Notice Lamellibranchiata, 2, p. 57. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 59, figs. 6-12. 1883.

A farther e.vamination of this form, with larger collections, indicates that
the characters upon which the species was founded may be only those belong-
ing to an immature shell.

In these forms the concentric undulations are comparatively more numerous,
and are not so distinctly limited by the umbonal ridge. The numerous
and characteristic concentric folds are shown in figs. 6, 7 and 10 of plate lix.
The ridge adjacent to the escutcheon, as shown in fig. 10, is due to the vertical
compression of the shell, and does not differ from the same part of the shell in
G. alveata when preserved in similar conditions. The same figure shows the
concentric undulations extending over the cardinal slope in a subdued degree,
not limited by the umbonal ridge. In figs. 8, 9 and 11, the concentric folds
pass over the umbonal slope in a subdued condition, and are not anywhere
abruptly terminated by the umbonal ridge as in characteristic specimens of G.
alveata. In form and other characters these specimens do not differ from that
species.

This form is more abundant than any other in the Hamilton group, and is
perhaps subject to greater variation from compression than any other of the
genus. When occurring in what appears to be its normal condition, the shell
is much longer on the posterior end ; but many of the individuals in the collec-
tion have been so distorted as to leave this part of the shell not more than half
as long as the anterior end. The same degree of distortion is liable to occur in
the height or depth of the valves, so as to produce an almost endless variety
of form.

This species occurs in all the localities cited for G. alveata.

\

372 PALAEONTOLOGY OF NEW YORK.

Grammtsia globosa.

PLATE LXII, FIGS. 10-19.

Chvmmyiiia gMntsa, Hall. Prelim. Notice Lamellibranchiata, 2, p. 57. 1870.

Cardimnorpha cordatux, H.\i.l. Piil. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 62, figs. 10-19. 1883.

Shkll below the medium size, sub-globose ; valves sub-circular, or very broadly
ovate; length a little greater than the height; basal margin- regularly
rounded, curving into the broad, rounded posterior margin. Cardinal line
about half the length of the shell. Escutcheon strongly marked, limited on
the exterior by a strong fold, with a smaller intermediate fold. Anterior end
somewhat broadly rounded below the lunule, which is distinctly marked and
sometimes margined by a narrow fold.

Valves ventricose.

Beaks at about the anterior third, very prominent and incurved. Umbonal
slope rounded, not defined from the general convexity of the shell, sometimes
with a narrow obsolescent fold.

Surface marked by fine concentric striae and strong rounded or sub-angular
concentric folds, which are sometimes duplicate, all becoming obsolete on the
posterior slope. Interior unknown.

Two specimens measure respectively 20 and 28 mm. in length, 20 and 23
mm. in height, and 20 and 20 mm. in the depth of both valves. A larger
specimen has a length of 33 mm. and a height of 27 mm.

This species bears some resemblance to the shorter forms of G. arcuata, but
differs in its ventricose character and circular form. Among all the collections
which have been made no individuals have been noticed which are larger than
those illustrated on plate Ixii.*

Formation and localities. In the shales of the Hamilton group, in Schoharie
county ; Leonardsville and Hamilton, Madison county, Pratt's falls, Onon-
daga county, and on the shores of Cayuga and Canandaigua lakes, N. Y.

* The reference to the genus Cabdiomorpha, aa above cited, arose from copying an erroneous recoi-d of
the species. At that time, the name Orammysia globosa, previously g^ven, was overlooked.

LAMELLIBRANCHIATA. 373

Grammysia zonata.

PLATE LXIII, FIGS. 4, 5.

Cardiomorpha zonata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 63, fig. 5. 1883.
Cardwnwrpha cmicentrica. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations ; PI. 63, fig. 4. 1883.

Shell small, ovate-elliptical ; length one-third greater than the height ; basal
margin regularly curving into the anterior and posterior margins Avithout
evidence of constriction. Cardinal line nearly straight, slightly declining
backward. Anterior end short, abruptly rounded.

Valves moderately convex in the lower and posterior portions, and gibbous
in the middle and umbonal region.

Beaks at about the anterior third, directed forward and incurved. Umbo-
nal slope sub-angular above, merging into the general convexity of the shell
below. Post-cardinal slope limited below by a strong fold, with a narrow
plication between it and the cardinal margin.

Surface marked by fine concentric striae and strong concentric ridges,
which are continuous to the post-cardinal slope. Interior unknown.

The two specimens described measure respectively 13 and 20 mm. in
length, and 8.5 and 13 mm. in height.

This species differs from G. bellatula in its more elliptical outline, the strong
continuous concentric undulations of the surface and the cardinal .slope marked
by two distinct longitudinal folds.

Formation and locality. In the Hamilton group, near Summit, Schoharie
county, N. Y.

Grammysia arcuata.

PLATE LXI, FIGS. 1-9; PLATE LXIU, FIG. 6? ; and PLATE XCIII, FIG. 37.

Poiidtmiat arcuata, CosvikD. Geol. Sui-v. N. Y., Ann. Rep., p. 03. 1841.

Orammysia arcuata (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 56. 1870.

" (Leptodomus) arcuata (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. 61, figs. 1-9. 1883.

" donorf/onnw. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 63, fig. 6. 1883.

Shell of medium size, ovate ; length about one-third greater than the height ;
basal margin moderately curved, straight or slightly concave along the middle.
48

374 PALEONTOLOGY OF NEW YORK.

Posterior extremity regularly rounded. Cardinal line nearly straight, slightly
declining posteriorly. The anterior end varies from regularly and narrowly
rounded to obliquelj' truncate below and abruptly rounded above.

Valves regularly convex below and posteriorly, becoming gibbous above and
in the umbonal region.

IJeaks sub-anterior, large and prominent, inclined forward. Umbonal
ridge not defined ; shell usually indistinctly flattened from the beak to the
basal margin, which is often constricted by this depression.

Surface marked by fine, close concentric strife and by strong rounded or
sub-angular concentric undulations, which are usually continuous from the
lunule to the margin of the escutcheon. These undulations are sometimes
duplicated, or others intercalated on the anterior li<ilf of the shell, which are
thence continuous to the posterior termination. In some older specimens these
ridges become obsolete on the umbonal slope. Test also marked by fine, dis-
tant radiating striae, which have been observed only on the posterior slope.

Lunule large but not distinctly limited. Escutcheon, in well-preserved
specimens, very distinctly defined by a broad depression margined longitud-
inally on each side by a low ridge. Characters of the interior unknown.

Five specimens measure respectively 34, 38, 40, 45 and 57 mm. in length,
and 22, 26, 26, 28 and 35 mm. in height.

This species differs from G. alveata in its more elongate form, more rounded
posterior extremity, flattened or constricted basal margin, and in having the
concentric folds usually extending with nearly undiminished strength across
the umbonal slope.

Formation and localities. In the arenjiceous shales of the Hamilton group, in
Schoharie county, and common in the softer shales in central and western New
York. It has also been obtained from the soft shales of this group at Patter-
son's creek, Virginia, and in the cherty layers above the Corniferous limestone
at the Falls of the Ohio.

LAMELLIBRANCHIATA. 375

Grammysia subarcuata.

PLATE LXI, FIGS. 10-2> ; and PLATE XCIII, FIG. 26.

Gh-ammysta imtiarcicata. Hall. Prelim. Notice Lamelllbranchiata, 2, p. 61. 1870.

Grammysia (Leptodomus f) subarcuatu, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 61,

figs. 10-22. 1883.

Shell of medium size, sub-ovate, widest at the posterior end; length more
than one-third greater than the height; basal margin regularly convex,
sometimes straight or constricted toward the anterior end. Posterior
extremity rounded, or obtusely sub-angular, often sub-truncate above. Car-
dinal line nearly straight. " Anterior end short, abruptly rounded below the
lunule.

Valves moderately convex in the lower and posterior part, becoming gib-
bous in the middle and umbonal region.

Beaks sub-anterior, prominent, inclining forward and strongly incurved.
Umbonal slope rounded. Post-cardinal slope flattened or concave, some-
times limited by an elevation, at which line the concentric undulations ter-
minate. Anterior to the middle of the shell, extending from the beak to
the basal margin, there is a depression or cincture which often gives a slight
undulation to the concentric folds and a constriction to the margin.

Surface marked by fine, close concentric striae and by strong sub-angular
concentric ridges or folds, which are frequently duplicate posterior to the
cincture. The surface is also marked by fine, radiating, pustulose striae,
which are often very conspicuous. Interior unknown.

Three specimens measure respectively 36, 38 and 48 mm. in length, and
20, 23 and 33 mm. in height. The largest specimen observed has a length
of 70 mm.

This species resembles G. arcmta in its general aspect, but differs in its more
elongate form, more pointed posterior end, and the cincture is much more
strongly marked.

Formation and localities. In the arenaceous layers of the Chemung group, at
Ithaca, near Elmira, Portville and Chemung, N. Y.

376 PALEONTOLOGY OF NEW YORK.

d. elongaia.

GrAMMYSIA PRiECCRSOR.
I'LATE LIX, FIG. 1.

Orammy-^ia prcuiirsor. Hall. Prelim. Notice Lamellibranchiata, 2, p. 54. 1S70.

Orammyaia (Le]>todtnniuif) pracursor, Hull. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. .59,

fig-. 1. 1883.

Shell small, transversely ovate ; length nearly twice the height ; basal margin
regulai'ly curved with a slight sinus anterior to the middle. Posterior ex-
tremity sub-angular. Cardinal line straight. Anterior end short, narrowly
rounded below the distinct lunule.

Valves regularly convex below and posteriorly, becoming very gibbous in
the middle and above.

Beaks sub-anterior, prominent and strongly incurved. Umbonal slope
sub-angular. A shallow, indistinct cincture crosses the valve about one-third
of its length from the anterior end.

Surface of the valves marked by numerous concentric folds, which are
sharp on the anterior end of the shell, becoming more distant and rounded
toward the umbonal slope, and partially obsolete near the posterior extrem-
ity, with a few interstitial ridges rising anterior to the middle of the valve.

Some portions of the shell still remaining on the cast show fine concentric
striae, with finer radiating lines. Interior unknown.

The specimen described has a length of 30 mm. and a height of IG mm.

In some of its characters this species bears a slight resemblance to G. arcuata,
but the undulations are finer, the valves narrower behind and marked by a
distinct sub-angular umbonal slope.

Formation and locality. In the Schoharie grit, at Schoharie, N. Y.

Grammysia secunda.

PLATE LIX, FIGS. 2, X

Orammyfia secunda. Hall. Prelim. Notice Lamcllibranchiata, 2, p. 54. 1870.

Pal. N. Y., vol. V, pt. 1. Plat<>» and Explanations: PI. 59, ftgs. 2, 3 (4, 5 in
en-or). 1883.

Shell small, sub-elliptical ; length about twice the height ; basal margin gently
curving, with a distinct sinuosity near the anterior end. Posterior extremity

LAMELLIBRANCHIATA. 377

sub-angular, truncate above. Cardinal line straight, nearly two-thirds the
length of the shell. Anterior end short, regularly rounded.

Valves regularly convex below and posteriorly, becoming moderately
gibbous in the middle and above.

Beaks sub-anterior, not prominent, incurved. Umbonal slope angular,
extending to the posterior extremity, with a distinct fold above the middle
of the cardinal slope, and only slightly divergent from the cardinal line.

Surface of the cast marked by strong concentric folds, which are angular
on the anterior end, but become broader and rounded as they approach the
umbonal ridge, beyond which they are obsolete.

Ligamental area deeply marked. Other characters of the interior un-
known.

The specimen described has a length of 33 mm. and a height of 18 mm.

This species differs from G. precursor in being less ventricose, in having
stronger and less numerous concentric folds, and a more defined cincture ;
and from G. arcuala in the distinct umbonal ridge, and much stronger post-
cardinal fold.

Formation and localitij. In the Upper Helderberg limestones, at Clarence
Hollow, Erie county, N. Y.

Gkammysia constricta.
i'late lix, figs. 13-30, (4, 5?) ; and platk lxxvm, figs. 26, 27.

Qrammysia (L-^odomasf) coHStrieta, Hall. Prelim. Notice Lamellibranchiata, 2, p. 58. 1870.

I. <> " •< Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 59,

figs. 13-20 1883.
Pholadella constricta. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 78, fi{,'-s. 26, 27. 1883.

Shell small, or below the medium size, narrowly ovate, widest in front ; length
nearly twice the greatest height ; basal margin gently curving, with a dis-
tinct sinus a little anterior to the middle. Posterior extremity sub-cuneate,
narrowly rounded. Cardinal line essentially straight, somewhat rapidly
declining toward the posterior end. Anterior end short, rapidly declining
from the beaks, sub-truncate above and rounded below.

378 PALEONTOLOGY OF NEW YORK.

Valves moderately convex, below and posteriorly, becoming gibbous above
the middle.

Beaks sub-anterior, prominent, closely incurved and rising above the
hinge-line. Umbonal slope rounded, prominent near the beaks, but grad-
ually merging into the general convexity about the middle of the length
of the shell. There is a distinct cincture extending a little backward from
the beaks to the basal margin.

Surfivce marked by fine concentric stria3, and extremely fine, pustulose,
nidiating striae; also by strong concentric undulations, which are sometimes
duplicate or intercalate near the anterior end and rarely in the middle of
their length, becoming obsolete before reaching, or upon, the post-cardinal
slope. The undulations are often a little deflected on the line of the cincture.

Ligamental area distinct and elongate. Characters of the interior unknown.

One specimen has a length of 40 mm. and a height from beak to base of 22
mm. A smaller individual has a length of 20 mm. and a height of 13 mm.

This species is easily distinguished from any in the Hamilton group by the
strong, nearly vertical, mesial cincture and elongate form.

The cincture in G. subarcuata is much farther anterior than in this species.

From G. communis it is distinguished by the greater distance of the beaks
from the anterior end ; by its narrower posterior extremity, and by the more
nearly vertical direction of the mesial cincture.

Formation and localities. In the arenaceous beds of the Hamilton group, near
Fultonham, and other parts of Schoharie county, and in the soft shales of the
formation on the shores of Seneca and Canandaigua lakes, N. Y.

Grammysia communis, n. sp.

PLATE LXI, FIGS. 84-28 ; AND I'LATE XCUI, FIG. 20.

In part Grammysia ffannibalensis, (Shdhard), Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 62. 1870.
" Orammys'w. {Leptodumust) Hannibalensis, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explana-
tions: PI. 61, figs. 23-33. 1883.
Not Allorimna Haunibaleniiu, Shdmard. Gleol. Surv. Missouri, Rep., pt. ii, p. 206, pi. C, tig 19. 185.').

Shell small, ovate-cuneate ; length less than twice the height ; basal margin
gently curving with a slight constriction just anterior to the middle of the

LAMELLIBRANCHIATA. 379

length, abruptly recurving at the post-basal extremity and obliquely truncate
above. Cardinal line nearly straight, scarcely declining posteriorly. Ante-
rior end short, obliquely truncate above, at the lunule, and abruptly rounded
below, having an angle at the junction of the two lines.

Valves regularly convex in the lower and posterior portions, becoming
gibbous above and especially on the post-umbonal slope.

Beaks sub-anterior, prominent, large, strongly incurved. Umbonal slope
obtu.sely sub-angular, and extending to the posterior extremity, with a faint
indication of a plication on the post-cardinal slope. Valves marked by a
distinct cincture extending from the beak, more or less obliquely, to the
basal margin anterior to the middle of its length.

Surface marked by fine concentric striae, which are obscurely visible in
the cast ; and by strong concentric undulations which mark the anterior and
central portion of the valves, becoming obsolete on the umbonal ridge. Inte-
rior unknown.

Five specimens measure respectively 29, 30, 32, 35 and 44 mm. in length,
and 17, 17, 21, 17 and 24 mm. in height.

This shell has been identified as Grammysia (Allorisma) Hannibalensis, of
Shu.m.'VRD, but compared with authentic examples of that species from the
original locality it is found to differ in its more elongate form, sub-angular
umbonal slope, more oblique cincture, and more strongly defined concentric
folds.

Formation and localities. In the Chemung group, at New Albion, Olean, Port-
ville, and Little Genesee, N. Y. ; and at Warren, Pa.

Grammysia undata.
plate lxi, rig. 23; plate lxiv, fig. 30; and plate xcm, fig. 21.

Kdwmlia undata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. G4, fig. 30. 1883.

Shell below the medium size; ovate sub-elliptical; length about one-third
greater than the height ; basal margin gently curving, nearly straight, and
slightly constricted anterior to the middle of its length. Posterior margin

380 PALEONTOLOGY OF NEW YORK.

curving upward to about the middle of its height, above which it is obUquely
sub-truncate. Cardinal line straight, more than two-thirds the length of the
shell, slightly declining posteriorly. Anterior end short, regularly rounded.

Valves regularly convex in the lower and posterior portion, becoming
gibbous in the middle and above.

Beaks at about the anterior third or fourth, rather prominent. Umbonal
slope sub-anguljir above, and sometimes continued obscurely to the post-inferior
extremity. Cincture broad, undefined, extending from the beaks to the base
anterior to the middle, and producing a flattening of the valve and a slight
constriction of the basal margin.

Surface marked by fine concentric striaa, with a few, more or less distinct,
concentric undulations, which become obsolete at about the umbonal angle.
Interior unknown.

Three specimens measure respectively 21, 25 and 30 mm. in length, and
14, 16 and 21 mm. in height.

This species resembles G. communis, but the concentric undulations are not so
numerous, the umbonal slope less defined, the posterior end broader and not
so obliquely truncate above the middle, and the cincture more nearly vertical.

Formation and localities. In the conglomerate of the Chemung group, at
Panama, and four miles north of Panama, N. Y. ; in the same horizon, at Alle-
ghany Springs, Warren county. Pa. ; also in some shaly sandstones, near Sala-
manca, and in the conglomerate, at Portville, N. Y.

Grammysia duplicata, n. sp.

PLATE XCin, FIG. 2S.

Shell small, ovate, abruptly depressed and cuneate behind ; length more than
one-third greater than the height ; basal margin regularly curved with a
scarcely perceptible sinus anterior to the middle. Posterior extremity
abruptly rounded below and shortly truncate above. Cardinal line straight,
margined by a narrow escutcheon. Anterior end about one-third the length
of the shell, pointed, truncate below the lunule. Margin of the lunule nearly
straight and slightly declining.

LAMELLIBRANCHIATA. 381

Valves regularly convex toward the ventral margin, depressed-convex at
the posterior end and ventricose in the middle and above.

Beaks at about the anterior third, large and prominent, incurving over
the hinge-line. Umbonal slope convex, gibbous above and gradually de-
clining into the general surface of the shell. Cardinal slope marked by one
or two inconspicuous folds. Cincture vertical, not strongly defined.

Surface marked by fine concentric striae and by numerous concentric folds,
which are strong aud angular upon the anterior end, becoming regularly
bifurcated along the line of the cincture and thence continued to the
post-cardinal slope where they become rather abruptly obsolete. Interior
unknown.

The specimen described has a length of 28 mm. and a height of 17 mm.

This species is distinguished by the regular duplication of the concentric folds
along the cincture. It is more gibbous than either G. communis or G. Han-
nibalensis, more abruptly depressed at the posterior extremity, and distinctly
angular at the anterior end, a feature observed only in the first species here
cited.

Formation and locality. In the upper beds of the Chemung group, at Warren,

Pa.

f

Gbammysia Hannibalensis.

PLATE LXI, FIGS. 29, 30, 33.

AUorisiiia HaniiibalenxUi, Shumard. Geol. Surv. Missouri, Rep., pt. ii, p. 20(i, pi. c, tig-. 19. 1855.

In part Grammysia Haimihalentds (Shumard), Hall, f relim. Notice Lamellibnmchiata, 2, p. 63. 1870.

1 " " Mebk. Pal. Ohio, vol. ii, p. 300. PI. 10 ; tigs, 5a, b, c. 1875.

., .. {Leptodcrmuxi) Hamubalensi.'i(iiii\iKKRD),Mki,i.. Pal. N. Y., vol. v, pt. 1. Plates and Ex-

planations: PI. 61, tigs. 23-33. 1883.

Shell below medium size, narrowly ovate or sub-elliptical ; length more than
one-third greater than the height; basal margin gently curved, more abruptly
curving at the anterior end, with a gentle sinus anterior to the middle.
Posterior extremity regularly rounded to about the middle of its height and
sub-truncate above. Cardinal line straight, extending more than half the
length of the shell. Anterior end abruptly rounded below the lunule.
49

382 PALEONTOLOGY OF NEW YORK.

Valves regularly convex, becoming gibbous above the middle and in the
umbonal region.

Beaks in advance of the anterior third, moderately elevated and incurved,
rising but little above the hinge. Umbonal slope rounded, not defined. A
broad gentle cincture extends from the beak to the ventral margin anterior
to the middle of the length.

Surface marked by fine, closely arranged, fasciculate concentric striae, and
by stronger concentric folds, which are more distinctly developed in the
anterior and umbonal region. Frequently the concentric folds are very
irregular in their development, often bifurcating on the anterior part of the
valves and becoming obsolete before reaching the umbonal slope.

Ligamental area narrow. Other characters of the interior unknown.

Three specimens have lengths of 40 mm. each and heights of 25 mm.
Two smaller individuals measure respectively 33 and 38 mm. in length and
19 and 22 mm. in height.

This species bears some resemblance to G. subarcuata, but is proportionally
more elongate and the concentric folds are much more strongly developed.

Formations and localities. In the Waverly sandstones, at Summit and Cuya-
hoga Falls, 0., and in the Lithographic limestone at Hannibal, Mo.

Grammysia plena, n. sp.

PLATE LXI, FIGS. 31, 32.

•
In part Grammy»ia Hannibal ai/ris (Shimaud), Hall. Pi-elim. Notieo Laiiiellibranchiata, 2, p. 62. 1870.

" " (Leptodomusf) Haimilialtn^is (fyHV.MAHD),UALh. Pal. N.Y., vol. v, pt. 1. Plates and Kx-

planations: PI. 61, fife'.s. 23-33. 1883.

Not AUnr'unaa HannihaleTixis, Shumard. Geol. Surv. Missoui-i, Rep., pt. ii, p. 206, pi. c, fig. 19. 1855.

Shell below the medium size, ovate ; length about one-third greater than the
height ; l)asal margin regularly curved from the post-basal extremity, except-
ing a gentle constriction, or sinus, at about the anterior third. Posterior
extremity obliquely truncate above. Cardinal line straight, more than half
the length of the shell. Anterior end short, abruptly rounded below the
lunule. Lunule deep and distinct, extending more than half way from the
beak to the base of the shell.

LAMELLIBRANCHIATA. 383

Valves regularly convex in the posterior portion, becoming very gibbous
and ventricose in the middle and umbonal region.

Beaks sub-anterior, prominent and strongly incurved. Umbonal slope
sub-angular, extending to the post-inferior extremity, producing a slight
angularity in the margin. Post-cardinal slope broad, marked by a distinct
fold along the middle, which produces an undulation in the margin of the
shell. A shallow cincture extends from the beak, reaching the ventral
margin at about the anterior third.

Surface marked by fine concentric striae, which are somewhat fasciculate
on the posterior portion of the shell, and by fine radiating pustulose striae in
well-preserved specimens. The anterior half of the shell is marked by
strong sub-angular folds, or undulations, which become obsolete on the mid-
dle of the shell, or sometimes extending to the umbonal angle. These con-
centric folds are frequently bifurcate at or about the cincture. Interior
essentially unknown.

Two specimens measure respectively 36 and 39 mm. in length, and 22 and
22 mm. in height.

This species more nearly resembles G. Hannibalensis than any other, but the
shell is more gibbous, the cincture is stronger, the posterior extremity very dis-
tinctly truncate and the post-cardinal slope with a more or less defined fold.

Formation and locality. In the yellow sandstones at Burlington, Iowa.

Grammysia (Sphenomya) cuneata.

PLATE LXII, FIGS. 1-9 ; AND PLATE XCIII, FIG. 19.

Orammysia (Sphenomya) cuneata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 62, figs.

1-9. 1883.

Shell of small or medium size ; ovate-cuneate, very oblique ; length more than
one-half greater than the height ; basal margin regularly curved, with some-
times a visible constriction toward the posterior end. Posterior end nar-
rowly rounded at the extremity and obliquely truncate above. Cardinal
line short ; margins apparently not inflected. Escutcheon large, limited by
an indistinct groove and fold. Anterior end very short, abruptly rounded
below the lunule.

384 PALEONTOLOGY OF NEW YORK.

Valves moderately convex below and posteriorly, gibbous in the middle
and umbonal region.

Beaks anterior, directed forward and strongly incurved. Umbonal slope
sub-angular, extending to the posterior margin above its greatest extension ;
above this there is another sub-angular fold. Post-cardinal area very wide.
Cincture obscure, often obsolete, continuing as an undefined depression from
the umbo to the basal margin near the posterior extremity.

Surface marked by very fine, regular concentric striae, and upon the ante-
rior portion of the shell by angular concentric undulations, which become
obsolete on the posterior slope, usually between the cincture and the um-
bonal ridge ; these undulations are rarely duplicate in the upper and middle
portions of the shell. In well-preserved specimens extremely fine radiating
striae have been observed on the post-cardinal slope, which may also extend
to other portions of the shell. In many specimens there are a few continu-
ous, stronger radiating striae along the posterior slope, upon the umbonal
angle and above. Interior unknown.

Four specimens measure respectively 25, 36, 38 and 39 mm. in length,
and 14, 20, 21 and 21 mm. in height. The largest individual observed has
a length of 55 mm.

This species somewhat resembles G. precursor, but differs in the comparatively
finer concentric folds, smaller anterior end, more cimeate form, less defined
umbonal angle and the very oblique cincture.

At some localities specimens are extremely abundant, usually of small size
and much distorted from pressure. In all the collections only two or three
individuals have been obtained preserving the entire form.

Formation and localities. In the shales of the Hamilton group, in Otsego,
Chenango, Madison. Onondaga and Seneca counties, N. Y.

LAMELLIBRANCHIATA. 385

EUTHYDESMA, n. g.

EUTHYDESMA 8UBTEXTILE.

PLATE LXIII, FIGS. 11-16; and PLATE XCIII, PIGS. 28,29.

Astarte mMextilis, Hall. Geol. Surv. N. Y., Rep. Fourth Dist., p. 245, fig. 6. 1843.
Cardioinnrpha suhlextUU, Hall. Prelim. Notice Lamellibranchiata, 2, p. 93. 1870.

" " " (textUis, in eirtrr). Pal. N. Y., vol. v, pt. 1. Plates and Explanations

PI. 63, figs. 11-15. 1883.

" undulata, " Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 63, fig. 16. 1883.

Shell large ; body broeidly sub-ovate, with a sub-alate cardinal expansion ;
length one-fifth greater than the height; basal margin very regularly curv-
ing to the post-inferior extremity, which is sub-truncate above. Cardinal
line rigidly straight. Anterior end short and regularly rounded.

Valves moderately convex in the posterior part, very gibbous in the mid-
dle and umbonal region.

Beaks sub-anterior, large, prominent and incurved. Umbonal slope rounded
and merging into the general convexity of the shell.

Surface marked by fine, sharp, elevated concentric striaa, which, in well-
preserved shells, are crossed by fine, slender, radiating striae, giving the sur-
face a cancellated appearance. At the intersection of the striae, minute
nodes are formed. In old shells the surface becomes raised into unequal
concentric undulations and also into stronger undulations, which cross the
lines of growth obliquely on the middle of the shell. Some specimens show
two low plications along the post-cardinal slope.

Hinge-line straight and marked by a distinct, continuous ligamental
groove. Other characters of the interior unknown.

Two specimens measure respectively 37 and 45 mm. in length, and 80 and
37 mm. in height. The largest specimen observed has a length of about
75 mm.

A careful comparison of this fossil with other species shows it to be so
entirely distinct in its form and exterior characters, as well as in the features
of the hinge, that there are no allies in our geological formations with which it

386 PALEONTOLOGY OF NEW YORK.

can be compared. The specimens, showing the strong oblique folds on the
umbonal slope, were separated from the others, and designated as Cardiomorpha
undulala, as cited above ; a farther comparison shows that these are only old
individuals of the original species.

Formation and locality. In the Portage group, six miles north-east of Port-
land Harbor, in Chautauqua county, N. Y.

EDMONDIA, De Koninck. 1844.
Edmondia rhomboidea.

PLATE LXIV, FIGS. 7, 8 ; AND PLATE XCV, FIGS. 15, 16.

BdtHondia rhomboidea (Hall), S. A. MtLLUR. Cat. Am. Pal. Foss., p. 191. 1877.

Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 64, figs. 7, 8. 1883.

Shell small, rhomboid, sub-circular ; length a little greater than the height ;
pallial margin regularly rounded from the two extremities, with the posterior
end sometimes sub-truncate. Cardinal line short and straight.

Valves regularly convex below, gibbous in the middle and above.

Beaks at about the anterior third, large and prominent, incurved. Umbo-
nal angle obtuse above, merging into the general convexity of the shell.

The surface of the cast preserves evidences of fine concentric striaB,
which are fasciculate on some portions of the shell, and of fine radii which
have been principally observed on the anterior half of the shell.

There is a slight fold, indicating a lateral tooth, on the postero-cardinal
margin. Other characters of the interior unknown.

The two specimens described measure respectively 22 and 23 mm. in
length, and 19 and 21 mm. in height.

This species somewhat resembles E. Philipi, but it is usually a more nearly
circular and more gibbous form.

Formation and localities. In the sandstones of the Chemung group, at Sala-
manca, and four miles north of Panama, N. Y.

LAMELLIBRANCHIATA. 387

Edmondia Philipi.

PLATE LXIV, FIGS. 9, 11-14, 17, 29; and PLATE XCV, FIGS. 1-4.

In part Edvumdia Philipi, Hall. Prelim. Notice Lamellibranchiata, 2, p. 90. 1870

" " " " Pal- N. Y., vol. V, pt. 1. Plates and Explanations : PI. 64, tigs. 9-18.

1883.
Biirlingtonensis (White and Wihtfibld), Hall. Prelim. Notice Lamellibranchiata, 2, p.

90. 1870.
Pal. N.Y., vol. V, pt. 1. Plates and Ex-
planations : PI. 64, figs. 19-29. 1883.

Shell of medium size or larger, very broadly elliptical ; length greater than the
height. Pallial margin regularly curving from the extremities. Posterior
margin sometimes sub-truncate. Cardinal line straight or gently curving.
Anterior end broad and regularly rounded.

Valves moderately convex in the lower and posterior part, becoming gib-
bous in the middle and above.

Beaks sub-central. Umbonal slope convex, not defined.

Test thin. Surface marked by fine, closely arranged, concentric striae,
which are sometimes raised into slender, lamellose expansions. Specimens
in the sandstones often show obscure, broad plications along the pallial mar-
gin which do not extend above the middle of the valve, and are not external
features of the shell. Interior unknown.

Three specimens measure respectively 29, 32 and 44 mm. in length, and
24, 25 and 38 mm. in height.

This species, in some of its smaller individuals, closely resembles the pre-
ceding.

The general form of the shell in the shales is broadly sub-oval, approaching
sub-circular ; the surface is finely striated concentrically with some gentle
undulations of the shell.

The sharp, distant, elevated, lamelliform striae which mark the surface of
some specimens are due to the condition of preservation, the finer striae having
been obliterated.

Formation and localities. In the shales of the Chemung group, at Philipsburgh
and Kockville, in the sandstones at Hobbieville, Randolph and Connewango,
N. Y., and in the shales and sandstones at Mansfield, Pa.

388 PALEONTOLOGY OF NEW YORK.

Edmondia obliqua, n. sp.

PLATE UUV, FIGS. 16, 83 (10?) ; AND PLATE XCV, FIGS. 6-8.

In imi-t Edmondia PhUipi, Hall. Pi-eliiii. Notice Lamellibranchiata, 2, p. 90. 1870.

•• " " " Pal. N. Y., vol. V, l>t. 1. Plates and Explanations: PI. 64, tigs. 9-18.

1883.
Biirlingtoneitsis (Wiiitk and Whitkikld), Hall. Prelim. Notice Lamellibranchiata, 2, p.

90. 1870.
" " •• Pal. N.Y., vol. V, pt. 1. Plates and Ex-

planations : PI. 64, figs. 19-29. 1883.

Shell of medium size, obliquely sub-rhomboidal ; length a little greater than
the height ; basal margin broadly curving. Po.sterior extremity sub-truncate,
abruptly rounded below. Cardinal line short, straight. Anterior end short,
sub-truncate.

Valves of moderate convexity below, somewhat gibbous in the umbonal
region.

Beaks sub-anterior, prominent, oblique, rising above the hinge-line and
incurved. Umbonal slope prominent, obtusely sub-angular above, and merg-
ing into the general convexity before reaching the post-inferior extremity.

Surface marked by fine concentric striae, which are more or less fascicu-
late, producing varices of growth.

Four specimens measure respectively 19, 20, 27 and 30 mm. in length, and
16, 19, 22 and 26 mm. in height.

This shell is distinguished by its oblique form and sub-truncate extremities.
In some of its phases it more nearly resembles E. Philipi than any other, but
the beaks are more oblique and more anterior, and the form is not so regularly
rounded.

Formation and localities. In the Chemung group, at Rock creek, Hobbieville
and Painted Post, N. Y. ; and Mansfield, Pa.

LAMELLIBRANCHIATA. 389

Edmondia subovata, n. sp.

PLATE LXIV, FIGS. 18, 19, 20, -.'6, 27, 28 (10, 21?) ; and PLATE XCV, FIGS. 9-12.

In part Edmondia Philipi, Hall. Prelim. Notice Lamellibranchiata, 2, p. 90. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 64, figs. 9-18.

1883.
" " BwUngUmeiusix (White and Whitfikld), Hall Prelim. Notice Lamellibranchiata, 2, p.

90. 1870.
" " " " Pal. N.Y., vol. V, pt. 1. Plates and Ex-

planations : PI. 64, figs. 19-29. 1S83.

Shell from medium to large size, broadly elliptical ; length about one-third
greater than the height ; basal margin gently curving in the middle, more
abruptly curving toward either extremity. Posterior margin regularly
rounded. Cardinal line nearly straight. Anterior end large, regularly
rounded.

Valves regularly convex, somewhat gibbous in the umbonal region.

Beaks at about the anterior third, prominent and incurved over the hinge.
Umbonal slope gibbous above, not defined nor affecting the post-inferior
margin.

Surface marked by fine, lamellose, concentric striae, which are unequally
fasciculate, sometimes making conspicuous varices of growth.

Three specimens measure respectively 33, 35 and 46.5 mm. in length, and
22, 25 and 31 mm. in height.

This species differs from E. Philipi in its broadly elliptical form and more
anterior position of the beaks, characters by which it may be readily distin-
guished.

Formation and localities. In the Chemung group, at Philipsburgh and Hobbie-
ville, N. Y. ; and Mansfield, Tioga county. Pa.

Edmondia transversa, n. sp.

PLATE LXIV, FIG. 24.

In part Edmondia BurlingUmensvi (Whitb and Whitfibld), Hall. Pal. N. Y., vol. v, pt. 1. Plates and

Explanations : PI. 64, figs. 19-29. 1883.

Shell of medium size, rhomboid-elliptical ; length one-third greater than the
height ; basal margin straight in the middle, curving gently toward either
50

390 PALEONTOLOGY OF NEW YORK.

extremity. Posterior margin vertically sub-truncate. Cardinal line straight.
Anterior end short, abruptly rounded below the lunule.

Valves convex below and posteriorly, gibbous in the middle and umbonal
region.

Beaks sub-anterior, rather prominent, rising a little above the hinge-line.
Umbonal slope prominent, scarcely defined, but extending to the post-inferior
extremity. Post-cardinal slope broad.

Surface marked by fine concentric striae, which are abruptly recurved over
the umbonal slope, and are fascicled, rising into lamellose elevations. Inte-
rior unknown.

A specimen has a length of 30 mm. and a height of 21 mm.

This species differs from E. Philipi in its rhomboidal form, truncate posterior
end, prominent umbonal slope and lamellose concentric striae.

Formation and localities. In the sandstones of the Chemung group, at Cold
Spring, Cattaraugus county, and doubtfully near Olean, N. Y.

Edmondia Burlingtonensis.

PLATE LXIV, PIG. 22 ; AHD PLATE XCV, FIGS. 13, 14.

JSdtnonrfia BwrZi/ipfoiie/MM, Whitb and Whitkikld. Pi-oc. Bost. Soc. Nat Hist., vol. 8, p. 301. 18')2.

In part ICdmondia Burlmgtmiensui (White and Whitkibi.d), Hall. Prelim. Notice Lamellibranchiata, 2,

p. 90. 1870.
" " " " " Pal. N. Y., vol. V, pt. 1. Plates and

Explanations: PL 64, figs. 19-29.

1883.

Shell of medium size, ovate-elliptical ; length one-third greater than the
height ; basal margin straight in the middle, curving into both extremities.
Posterior margin regularly rounded. Cardinal line straight. Anterior end
short and regularly rounded.

Valves moderately convex below and posteriorly, gibbous in the middle
and umbonal region.

Beaks at about the anterior fourth, prominent, incurved. Umbonal slope
convex, not defined, merging into the general convexity of the shell before
reaching the post-inferior extremity.

LAMELLIBRANCHIATA. 391

Surface marked by fine concentric striae, which are more or less fascicu-
late, producing undulations which are more conspicuous on the posterior half
of the shell.

The specimen figured has a length of 27 mm. and a height of 18 mm.
Another individual has a length of 25 mm. and a height of 17 mm.

As compared with E. suhovata the beaks are more anterior, the basal mar-
gin is less convex, the umbo is narrower, the umbonal slope more prominent and
the post-cardinal slope is wider.

In tig. 22 of plate Ixiv, the beak is represented as too prominent, giving a
disproportionate height to the shell, and the posterior end is too wide.*

Formation and locality. In the Yellow sandstones, at Burlington, la.

Edmondia depressa.

PLATE LXIV, FIG. 32

EAmondia depreum. Hall. Prelim. Notice Lamellibi-anchiata, 2, p. 91. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 64, fig. 32. 1883.

Edtnondiaf tapemfurmU. Mkek. Pal. Ohio, vol. 11, p. 304, pi. 13, fig. 6. 1875.

Shell large, ovate-elliptical, sub-quadrangular ; length more than one-fourth
greater than the height ; basal m.argin gently curving to the post-inferior
extremity, where it is abruptly recurved and obliquely sub-truncate above.
Cardiniil line straight, scarcely declining posteriorly. Anterior end short and
regularly rounded.

Valves depressed-convex below and posteriorly, and somewhat gibbous
above.

Beaks sub-anterior, moderately prominent (much too prominent, as repre-
sented in the figure), slightly inclined forward and rising but little above the
hinge-line, Umbonal slope regularly rounded.

* The figure of E. Burliiuftonenslii, above cited, was made and lithographed about fifteen years since,
under the direction of Mr. R. P. Whitfirld, from a specimen then in his collection, and may therefore be
considered authentic. The other forms identified by him as of the same species, and thus published in
the " Preliminai-y Notice " and " Plates and Explanations," cited above, have, on farther examination,
proved to be distinct from that one, and are thus described in this volume. The illustrations on plate xcv
will serve to give a more satisfactory expression of the specific characteristics.

392 PALEONTOLOGY OF NEW YORK.

Surface marked by regular, coarse concentric strisB, which are sometimes
fasciculate, forming low undulations. Interior unknown.

The specimen described has a length of 48 mm. and a height of 35 mm.

This species differs from E. Philipi in its more elongate form, sub-anterior
beaks, longer hinge-line and coarser and more regular concentric strioB.

The specimen fig. 31, plate Ixiv, from the conglomerate, near Olean, was
originally referred to this species, but it is apparently distinct, differing in its
smaller beaks, sub-angular umbonal ridge and more truncate posterior extremity.

Formation and locality. In the Waverly sandstone, Licking county, 0.

Edmondia ellipsis, n. sp.

PLATE LXIV, FIG. S6.

In part EdinondUi BtLrliiigtonensis (Whitk and Whitfibld), Hall. Pal. N. Y., vol. v, pt. 1. Plates

and Explanations : PI. 64, figs. 19-29. 1883.

Shell large, broadly elliptical ; length more than one-fourth greater than the
height; basal margin regularly curving, and recurved over the posterior
end without any abrupt change, and thence to the cardinal line. Cardinal
line straight, slightly declining posteriorly. Anterior end short, regularly
roimded.

Valves moderately convex in the lower and posterior portions, becoming
gibbous above and in the umbonal region.

Beaks sub-anterior, moderately prominent. Umbonal slope convex, not
defined.

Surface marked by somewhat fine concentric striae, which are sometimes
elevated and lamellose, curving over the umbonal slope and joining the
cardinal line at a very small angle.

The hinge preserves a linear cardinal fold or groove posterior to the
beaks. Other characters of the interior unknown.

The specimen described has a length of 43 mm. and a height of 30 mm.

This species differs from E. Philipi in its more anterior beaks and longer

LAMELLIBRANCHIATA. 393

hinge-line ; and from E. depressa in its more gibbous form, narrower posterior
end, and more regular curvature of the basal margin into the posterior margin.
Formation and locality. In the Burlington sandstones, at Burlington, la.

EdMONDIA ? TENDISTRIATA, n. sp.

PLATE LXIII, FIGS. 9, 10 ; AND PLATE XCV, FIG. 17.

Cardvnnorpha xuborbiculariJi, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 63, figs. 9, 10.

1883.
Not " " " 8. A. Miller. Cat. Am. Pal. Foss., p. 186. 1877.

Not UngiUina suix>ti)icidarig. Hall. Geol. Surv. N. Y., Rep. Fourth Dist., p. 243, t. 106, fig. 2. 1843.

Shell of medium size, sub-orbicular ; length a little greater than the height.
Pallial margin regularly curved. Cardinal line short and straight.

Valves moderately convex, scarcely gibbous in the umbonal region.

Beaks sub-central, slightly tumid, rising but little above the hinge-line.
Umbonal slope undefined.

Surface marked by fine, regular, concentric striae, which are cancellated by
fine radiating striae ; the latter more conspicuous on the posterior slope.
Interior unknown.

The specimen described has a length of about 25 mm. and a height of 23
mm.

This species has been compared with and supposed to be identical with Ungu-
lina suborbicularis, loc. cit., but it is entirely distinct from that form and from a
different horizon. Its generic relations cannot be satisfactorily determined, and
it is placed provisionally under the genus Edmondia. But two specimens have
been observed and are worthy of note on account of their peculiar form and
surface characters.

Formation and locality. In the shales of the Chemung group, near Elmira,
N. Y.

394 PALEONTOLOGY OF NEW YORK.

SPHENOTUS, N. G.
Sphenotus truncatcs.

PLATK LXF, FIGS. 1, *-6.

Oyprieardites truneatux, Conrad. Jour. Acad. Nat. Sci., Phila., vol. viii, pi. 12, fig. 17, p. 244. 1842.
Sanffuiiwlites truncatus (Conbad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 42. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 65, figs.

1-6. 1883.

Shell small, trapezoidal ; length twice the height; basal margin nearly straight,
slightly constricted anterior to the middle. Posterior extremity obliquely
truncate. Cardinal line straight. Anterior end narrow, rounded.

Valves depressed-convex at the posterior end, moderately convex below,
becoming gibbous above the middle.

Beaks at about the anterior fourth or fifth, small, oppressed, incurved,
rising but little above the hinge-line. Umbonal slope angular, extending to
the post-inferior extremity. Post-cardinal slope flat, or concave, with an
obscure fold along the middle. A shallow cincture extends from the beak
obliquely to the base of the shell.

Surface marked by fine concentric striae, which are fasciculate on the
anterior portion and umbonal region, producing low undulations ; also marked
by very fine radiating striae. Interior unknown.

Three specimens measure respectively 10, 15 and 18 mm. in length, and 5,
7 and 9 mm. in height.

This species differs from S. arcmformis in its straighter basal margin, less
pointed and less obliquely truncate posterior end and in its smaller size.

Formation and localities. In the shales of the Hamilton gi'oup, at Summit and
Bear's gulf, Schoharie county, and on the shore of Skaneateles lake, N. Y.

LAMELLIBRANCHIATA. 395

Sphenotus arc^formis.

PLATE LXV, FIGS. 7-11; AND PLATE LXVI, PIG. .13?

SanguinoUtes arcceformis. Hall. Prelim. Notice Lamellibranchiata, 2, p. 40. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 65, figs. 7-U. 1883.

" Molus, Hall (in error). Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 66, fig. 43.

1883.

Shell of medium size, trapezoidal ; length usually more than twice the height ;
basal margin gently curved, sometimes nearly straight in the middle. Pos-
terior extremity obliquely truncate. Cardinal line straight, slightly declin-
ing posteriorly. Anterior end short, sloping rapidly from the beak and
narrowly rounded below.

Valves becoming gibbous in the middle and umbonal region.

Beaks at about the anterior fourth, small and closely appressed. Umbonal
slope distinctly angular, extending to the post-inferior extremity. Post-
cardinal slope concave, and marked by a scarcely defined fold which is nearer
to the umbonal ridge than to the cardinal margin. Most of the specimens
show a flattening or undefined depression extending from the beaks to the
basal margin.

Surfsvce marked by extremely fine concentric striae, which sometimes
become fasciculate in the anterior portion of the shell, and are undulating
on the post-cardinal slope ; also by fine radiating striae, which are rarely
well-preserved, and are mainly confined to the posterior half of the shell.

Five specimens measure respectively 23, 28, 32, 26 and 26 mm. in length,
and 11, 13, 14, 14 and 11.5 mm. in height.

This species diifers from S. cuneatus in its smaller size, narrower posterior
extremity, more convex basal margin, less conspicuous post-cardinal ridge, and
in the surface characters.

Formations and localities. In the shales of the Hamilton group, near Delphi,
at Pratt's falls and on the shore of Skaneateles lake, Onondaga county, N. Y. ;
and doubtfully in the Chemung group near Smethport, Pa.

396 PALEONTOLOGY OF NEW YORK.

SpHENOTUS C0NEATUS.

PLATK LXV, FIOS. li-17.

Plerinea eamata, Cohrad. Geol. Sui-\'. N. Y., Ann. Rep., p. 1 IG. 1838.

/Saiiffuhuilite* luueatux (Conrad), Hall. Pi-elini. Notice Laniellibranchiata, 2, p. 39. 1870.

" " " " Pnl. N. Y., vol. V, pt. I. Plates and Kxplanation.s : PI. G."), tig».

12-17. 1883.

Shell large, trapezoidal ; length more than twice the height ; basal margin con-
stricted anterior to the middle and gently curving to both extremities. Pos-
terior extremity obliquely sub-truncate, sinuate. Cardinal line straight.
Anterior end short, rapidly declining from the beak and narrowly rounded
below.

Valves depressed-convex posteriorly, moderately convex below the middle
and becoming somewhat gibbous in the umbonal region.

Beaks sub-anterior, small, flattened and closely appressed. Umbonal slope
marked by an obtusely angular fold or ridge, extending to the post-inferior
extremity. Post-cardinal slope concave, marked along its centre by a low
fold, which is a little nearer the cardinal line than to the umbonal ridge,
extending to the posterior extremity. Cincture oblique, extending from the
beak to the base of the shell, producing a depression of the surface and a
sinuosity in the margin.

Surface marked by fine concentric striae, which become fasciculate and
often form low undulations anterior to the umbonal ridge ; also by fine radi-
ating strisB on the body of the shell, which have not been observed on the
post-cardinal slope.

Four specimens measure respectively 33, 42, 42 and 48 mm. in length, and
14, 17, 18 and 19 mm. in height.

This species differs from S. arceformis in its proportionally greater length,
with a greater height at the posterior end ; in its sinuate posterior margin,
constricted basal margin and more regular concentric striae.

In certain conditions of preservation, the radiating striae are obscure or
ob.solete, and sometimes worn by weathering, and are therefore not to be relied
upon as characterizing the species in all cases.

LAMELLIBRANCHIATA. 397

The identification with Mr. Conrad's species was made from a lithographed
figure which has never been published.

Formation and locality. In the shales of the Hamilton group, in Schoharie
county, N. Y.

Sphenotus subtoktuosus.

PLATE LXV, FIGS. 18, 19.

Sangui7u>lite.i subtortvosux, H.KLL. Prelim. Notice Lamellibi-anchiata, 2, p. 41. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 65, tigs. 18, 19.

1883.

Shell largc,^ robust, trapezoidal ; length more than twice the height ; basal
margin constricted anterior to the middle /ind gently curving to either
extremity. Posterior extremity doubly truncate. Cardinal margin straight
or gently arcuate, and very slightly declining posteriorly. Anterior end
short, abruptly declining from the beak and narrowly rounded below.

Valves moderately convex posteriorly, becoming gibbous in the middle
and umbonal region.

Beaks sub-anterior, attenuate, appressed and incurved, rising but little
above the hinge-line. Umbonal slope marked by a low ridge, extending to
the post-inferior extremity, becoming undefined below the middle of its
length. Post-cardinal slope convex, marked along the middle of its width
by a low ridge, extending from the beaks to the posterior extremity, produc-
ing an angularity in the margin. Cincture broad, distinct, extending from
the beaks and constricting the basal margin a little anterior to the middle.

Surface marked by fine concentric striae, which in some parts of the shell
are fa.sciculate, producing low undulations of the surface ; Jind also by fine
radiating striae, which are often not well-preserved.

Ligiimental area narrow ; characters of the interior unknown.

Two specimens measure respectively 50 and 55 mm. in length, and 23 and
26 mm. in height.

This shell resembles the preceding, but is a larger and more robust form, the
valves are more gibbous ; the umbonal ridge is distinctly arcuate, not so

398 PALEONTOLOGY OF NEW YORK.

strongly developed, and becoming obsolete toward the post-inferior extremity ;
the posterior margin is distinctly doubly truncate, with the lower truncation
vertical, and the cincture is more strongly marked.

Formation and localities. In the shales of the Hamilton group, at Fultonham,
Schoharie county, and at York, Livingston county, N. Y.

Sphenotus solenoides.

PLATE LXV, FIGS. 21-29.

Satiffuinolites solenoides. Hall. Prelim. Notice Lamellibranchiata, 2, j). 38. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 65, figs. 21-29. 1883.

Shell large, trapezoidal ; length more than twice the height ; basal margin
nearly straight, slightly arcuate in the centre, curving toward the anterior
end. Posterior extremity obliquely truncate. Cardinal line straight, about
half the length of the shell, parallel to the basal line. Anterior end long,
gradually declining from below the beaks and narrowly rounded at the
extremity.

Valves moderately convex below and posteriorly, becoming somewhat gib-
bous in the middle and umbonal regions.

Beaks situated about two-fifths of the length of the shell from the ante-
rior end, small, appressed and incurved, rising but little above the hinge-
line. Umbonal slope distinctly angular, extending to the post-inferior
extremity. Post-cardinal slope flat or slightly concave, with an obscure fold
along the middle, extending to the posterior extremity. Cincture indistinct,
appearing as a flattening or slight depression, extending from the beak to
the basal margin anterior to the middle. (This feature is frequently obso-
lete, except in well-preserved specimens.)

Surface marked by fine concentric striae, which are fasciculate, producing
more or less distinct folds or undulations upon the anterior and middle por-
tions of the shell, and- bending abruptly upward on crossing the umbonal
ridge. The posterior half of the shell, especially above the umbonal ridge,
is further marked by fine, irregular, elevated vascular lines. In some speci-

LAMELLIBRANCHIATA. 399

mens similar markings appear, in a subdued degree, over the anterior portion
of the shell. Interior unknown. Ligamental area narrow.

Four specimens measure respectively 28, 33, 38 and 42 mm. in length,
and 12, 14, 16 and 16.5 in height. The largest specimen observed has a
length of 72 mm. and a height of 28 mm.

This species is distinguished by its long anterior end and peculiar ornamen-
tation on the posterior half of the shell.

Formation and localities. In the shales of the Hamilton group, Sherburne
creek near Sherburne, Hamilton, Bellona and on the shores of Canandaigua and
Cayuga lakes, N. Y.

Sphenotus contractus.

PLATE LXVI, FIGS. 1, 3-9, U-13, 15 (10, IB, 17, 19?); AND PLATE XCIV, FIG. 2.

Cypricardia eontravia. Hall. Geol. Sui-v. N. Y., Rep. Fourth Dist., p. 292, t. 139, fig. 4. 1S43.

In part Sanyuiiwlites rU/Uliis (White and Whitfield), Hall. Prelim. Notice Lamellibranchiata, 2, p. 44.

1870.
" " " " " Pal. N. Y., vol. V, pt. 1. Plates and Ex-

planations: PI. 66, figs. 1-19. 18S3.

Shell ranging from small to large size; trapezoidal, wider behind; length
more than twice the height; basal margin nearly straight, scarcely con-
stricted in the middle and gently curving to either extremity. Posterior
extremity oblique, somewhat doubly truncate. Cardinal line straight, long,
nearly parallel to the basal margin. Anterior end short, abruptly declining
from the beak and narrowly rounded below.

Valves of moderate convexity, except in the upper portion and umbonal
region, where they are gibbous.

Beaks sub-anterior, small, appressed and closely incurved over the hinge-
line. Umbonal slope distinctly angular, extending to the post-inferior
extremity. Post-cardinal slope flat, marked along its centre by a distinct
fold, which reaches to the posterior end, producing an extension of the mar-
gin, leaving a more oblique truncation above than below. Cincture without
distinct limitation, producing a flattening above and a slight depression
below the middle of the valve.

400 PALJEONTOLOGY OF NEW YORK.

Surface marked by fine, somewhat regular concentric striae, with obscure
indications of radiating striae upon the middle of the shell. The post-
cardinal slope is sometimes marked with fine undulating and bifurcating
vascular lines, which become obsolete below the umbonal ridge.

Ligamental area narrow. Hinge marked by two short triangular cardinal
teeth in the right valve, and by one or two extremely slender lateral teeth.
Anterior muscular impression strongly marked ; posterior scar shallow. Pal-
lial line simple, distinctly marked by closely arranged radiating lines extend-
ing from above and terminating at the line.

Five specimens measure respectively 29, 31, 32, 37 and 43 mm. in length,
and 13, 13, 15, 15 and 19 mm. in height.

This species resembles S. cuneatus, but the umbonal ridge is not so strongly
marked, the cincture is a much less conspicuous feature, and the posterior end
is more pointed.

Formation and localities. In the Chemung group at Philipsburgh and Rock-
ville, Alleghany county ; near Olean and Randolph, Cattaraugus county ; near
Ellington and north of Panama, Chautauqua county, N. Y. ; and at Warren and
Alleghany springs, Warren county, Pa.

Sphenotus (?) ARCUATUS, n. sp.

I'LATE LXVI, FIG. 18.

In part SanffuinolUes rigidus (White anil Wiiitkikld), Hai.i.. Pal. N. Y., vol. v, pt. 1. Plates and Expla-
nations: PI. 66, figp. l-lt>. 1883.

Shell large, elongate, sub-trapezoidal, arcuate ; length more than twice the
height ; biisal margin gently arcuate. Posterior extremity obliquely trun-
cate. Cardinal line long, straight, more than half the length of the shell,
parallel to the basal margin. Anterior end short, abruptly rounded below.

Valves becoming gibbous in the middle and umbonal region.

Beaks sub-anterior, appressed, incurved, rising but little above the hinge-
line. Umbonal slope obtusely angular, arcuate, declining gently to the
middle of the shell and then more abruptly to the post-inferior extremity.

LAMELLIBRANCHIATA. 401

Post-cardinal slope broad. Cincture extending from the beak obliquely to
the base, becoming broatl below the middle of the shell.

Surface marked by fine concentric striaj, the impressions of which are
preserved upon the cast.

Anterior muscular impression deeply marked, limited posteriorly by a
ridge, situated just below the beaks. Pallial line continued parallel to the
basal margin, recurving over the umbonal ridge and terminating in a large
muscular scar on the post-cardinal slope.

The specimen described has a length of 50 mm. and a height of 2?> mm.

•This species .somewhat resembles S. subtoHuosus, but the umbonal ridge is
more arcuate, the cardinal slope is wider and without distinct plication.

Formation and locality. In a conglomerate of the Chemung group, east of
Panama, N. Y.

Sphenotus clavulus.

PLATE LXVI, FIGS. 2, 20-26.

SaugaiHolite* f claenlitu, Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 45. 1870.

" " " Pal. N.Y.,vol. V, pt. 1. Plates and Explanations : PI. C6, figs. 20-26. 1883.

Shell of medium or large size, elongate, sub-trapezoidal ; length more than
two and a half times the height; basal margin nearly straight or slightly
arcuate in the middle, curving to the anterior and posterior extremities.
Posterior extremity narrowly rounded below and oblique above. Cardinal
line straight, .sli^itly declining posteriorly, nearly parallel to the basal mar-
gin and extending more than half the length of the shell. Anterior end
declining more or less abruptly from the beaks and narrowly rounded below.

Valves moderately convex below, gibbous in the middle, and on the umbo-
nal slope to beyond the middle of its length.

Beaks sub-anterior, small, closely appressed, incurved, and rising very
little above the hinge. Umbonal slope sub-angular from the beak to the
middle of its length, becoming rounded and less defined below and reaching
the post-inferior extremity. Post-cardinal slope moderately convex, with

402 PALEONTOLOGY OF NEW YORK.

an obscure fold which may sometimes be obsolete. Cincture scarcely per-
ceptible, sometimes producing a sliglit constriction in the inferior margin.

Surface marked by fine concentric striae, which may be more or less fas-
ciculate, producing gentle undulations of the surface. No radiating striae
have been observed.

Ligamental area narrow. Anterior muscular impression strongly marked.

Five specimens measure respectively 29, 31, 46, 48 and 49 mm. in length,
and 12, 13, 17, 17 and 18 mm. in height.

The shell is proportionally longer and narrower than any of the preceding
species, the form is more arcuate and there is no conspicuous fold on the post-
cardinal slope.

Formation and localities. In the Chemung group, at Philipsburgh, and in loose
masses of sandstone near Portville and Olean, N. Y.

Sphenotus rigidus.
plate lxvi, fig. 11.

Cypricardiaf rigida. White and Whitfield. Proc. Bos. Soc. Nat. Hist., vol. viii, p. 300. 1862.
In part Sanguhwlites rigidiis (White and Whitfield), Hall. Prelim. Notice Lamellibranchiata, 2, p. 44.

1870.
" " " " " Pal. N. Y., vol. V, pt. 1. Plates and Expla-

nations : PI. G6, figs. 1-19. 1883.

The figure is from the original specimen described.* It differs from S. con-
tractus in its more robust, shorter and more rigid form, more obtuse post-inferior
extremity, and more nearly vertical lower truncation of the posterior end. The
supposed clavicle corresponds with the posterior limit of the anterior muscular
impression as shown in fig. 9 of plate Ixvi.

Formation and locality. In the Yellow sandstones, at Burlington, la.

* The specimens here described as S. contraetus and 8. arcitattis wei-e identified by Mr. R. P. Whitfibld
as belonging to SaTiffuinolitex rigidux, White and Whitfield, and tluis refeiTed in the Preliminary Notice
of the Lamellibranchiata, 2 (above cited), and at the same time were thus arranged on the Plates for the
Pala;ontology of New York, then being lithographed. A cai-eful comparison of specimens with a cast of the
original of A. rigidus has shown the necessity of separating the Chemung 8})ecies, and recognizing in one of
the forms, the original of Cypricardia contracta, published in 1843.

LAMELLIBRANCHIATA. 403

Sphenotus flavius.

PLATE LXVI, FIGS. 27-29.

Sanguinolitm ? flavius, Hall. Prelim. Notice Lara3llil)i'anchiata, 2, p. 47. 1870.

" " " Pal. N. Y., vol. V, lit. 1. Plates and Explanations : PI. 66, figs. 27-29. 1883.

Shell of medium size, elongate, sub-cylindrical ; length nearly three times the
height in the vertically compressed specimen described ; basal margin gently
curving, straight or slightly constricted about the middle of its length. Pos-
terior extremity narrowly rounded or sub-acute, obliquely truncate above.
Cardinal line straight, nearly parallel to the basal margin. Anterior end
short, narrowly and sub-acutely rounded.

Valves moderately convex below and posteriorly, gibbous in the middle
and umbonal region.

Beaks sub-anterior, moderately prominent. Umbonal slope rounded,
scarcely sub-angular near the beaks, extending to the posterior extremity.
Post-cardinal slope with an obscure fold or plication. Cincture oblique, not
strongly defined, extending from the beaks to near the middle of the base.

Surface marked by fine concentric striaB of growth, which become fascicu-
late and form unequal undulations upon the posterior and umbonal portions
of the shell ; also marked by fine radiating striae. Interior unknown.

The specimen described has a length of 44 mm. and a height of 14.5 mm.

This species differs from any of the preceding forms in the anterior position
of the beaks. The extension of the umbonal slope to the middle of the poste-
rior end, and the gaping of the valves, are due to vertical compression.

Formation and locality. In the Waverly sandstones of Licking county, 0.

Sphenotus valvulus.

I'LATB LXVI, FI(i. 30.

Kanguinolites valmiluK, Hail. Pi-elim. Notice Lftmellibi-aiichiata, 2, p. 46. 1870.

.' " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 66, fijf. 30. 1883.

Shell large, sub-cylindrical, very elongate posteriorly ; length less than three
times the height ; basal margin very gently curving, with a slight constric-

404 PALEONTOLOGY OF NEW YORK.

tion near the anterior end. Posterior extremity apparently slightly gaping,
narrowly rounded ; the greatest extension being in the line of the longitud-
inal axis. Cardinal line straight, about two-thirds the length of the shell,
parallel with the basal margin. Anterior end short, gently declining from
the beaks and rounded below.

Valves moderately convex.

Beaks sub-anterior, low, closely appressed. Umbonal slope obscurely
marked by two low ridges, one extending to the post-inferior margin and the
other to the middle of the posterior end. Post-cardinal slope marked by an
obscure fold. Cincture narrow, not strongly defined, extending from the
beak to the basal margin at about the anterior third of the length of the
shell.

Surface marked by fine concentric striae, which, from the appearance of the
cast, have been fasciculate on the anterior and posterior ends of the shell.
No radiating stria? have been observed. Interior unknown.

The specimen described has a length of 49 mm. and a height of 18 mm.

This species is entirely unlike the other forms here described in its elongate
hinge-line, gentle convexity of the valves and undefined umbonal ridge.

Formation and locality. In the Waverly sandstones, at Newark, Licking
county, O.

Sphenotus ^olcs.

PLATE LXVI, YIQS. 31-K.

Sanguinnlites jSitlus, Hall. Pi-elim. Notice Lamellibrancfaiata, 2, ]>. 46. 1K70.

" " " Pal. N. Y., vol. V, i)t. 1. Plates and Explanations: PI. 66, figs. Sl-S."). 1883.

Shell large, elongate-ovat«, sub-trapezoidal ; length more than twice the
height ; basal margin gently rounded, sometimes nearly straight. Posterior
extremity obliquely sub-truncate. Cardinal line straight, or slightly arch-
ing and gently declining posteriorly. Anterior end declining gently from
the beaks and abruptly rounded below.

Valves convex below, gibbous in the middle and um1)onal region.

Beaks sub-anterior, small, appressed, closely incurved, rising but little

LAMELLIBRANCHIATA. 405

above the hinge-line. Umbonal slope distinctly angular, extending to the
post-inferior extremity. Post-cardinal slope flat or convex, with an obscure
fold along the middle, which may be obsolete in the cast. Cincture not
conspicuous, consisting of a slight depression or constriction extending from
the beaks oblifiuely backward to about the middle of the shell.

Surface marked by fine concentric stria?, which become fascicled, produc-
ing low undulations, which are usually more conspicuous on the anterior and
posterior portions of the shell ; also obscurely marked, in the cast, by fine
ra<liating striae posterior to the cincture. Interior unknown.

Three specimens measure respectively 50, 44 and 37 mm. in length, and
22, 20 and 16 mm. in height.

This species closely resembles S. rigidus, but the cincture is more oblique,
extending further backward on the basal margin ; the post-cardinal slope is
narrower and less distinctly marked by a fold along the middle.

Formation and locality. In the Waverly sandstone, at Newark, 0.

Sphenotus signatcs, n. sp.

PLATE XCIV, FIG. 3.

Shell large, very elongate-elliptical ; length nearly three times the height ;
basal margin gently curving. Posterior extremity doubly truncate, vertical
below and oblique above. Cardinal line long, very gently arcuate. Ante-
rior end produced, declining from the beaks and narrowly rounded.

Valves moderately convex along the basal and posterior portions, becom-
ing gibbous in the middle.

Beaks sub-anterior, small, but little elevated above the hinge. Umbonal
ridge rounded, scarcely angular, extending to the post-inferior extremity.
A sub-angular fold extends along the middle of the post-cardinal slope.

Surface marked by fine concentric striae, which are distinctly undulated
in passing over the umbonal and cardinal ridges.

The specimen described has a length of 55 mm. and a height of 20 mm.
52

406 PALEONTOLOGY OF NEW YORK.

This form is comparatively more elongate than any other species. In its
strong post-cardinal fold it may be compared with S. cuneatus and S. subtortuo-
sus of the Hamilton group, but it has no anterior depression nor sinuosity of
the pallial margin. The produced anterior end and regularly curving basal
margin are distinguishing characters.

Formation and locality. In the Waverly group, at Warren, Pa.

Sphenotus Telamon, n. sp.

PLATE XCIV, FIG. 1.

Shell large, elongate sub-elliptical ; length more than twice the height ; basal
margin very gently curved. Posterior extremity narrowly rounded below
and obliquely truncate above. Cardinal line very slightly arcuate. Ante-
rior end declining from the beaks and somewhat narrowly rounded below.

Valves gently convex in the lower and posterior portions, becoming gib-
bous in the middle.

Beaks at about the anterior fourth, incurved. Umbonal slope obtusely
angular above, extending to the post-inferior margin. Cardinal slope wide,
marked along its centre by a distinct fold, which extends to the upper pos-
terior margin.

Surface marked by fine concentric strias, which on the middle and poste-
rior portions are irregularly fasciculate, forming distinct undulations of the
surface ; anterior end with regular sub-angular ridges. The striae at the
post-inferior extremity are almost rectangularly recurved.

The specimen described has a length of 59 mm. and a height of 26 mm.

This species in its general external characters resembles Allorisma, but the
limitation of the post-cardinal slope by the umbonal angle and the distinct pli-
cation along the middle of this area are characteristic features of Sphenotus,
and on this account it is placed under that genus.

Formation and locality. In the Chouteau limestone of the lower Carbonif-
erous, in Cooper county, Mo.

I

LAMELLIBRANCHIATA. 407

SPATHELLA, n. gen.
Spathella typica.

PLATE LXVI, FIGS. 36-10.

In part SanguinoHten ventricoims (White and Whitfikld), Halt,. Pal. N. Y., vol. v, pt. 1. Plates and

Explanations : PI. G6, tigs. 36^2. 1883.

Shell of medium or large size, from sub-cylindrical to elongate-ovate, wider
behind ; length from two and a half to less than twice the height ; basal
margin gently curved, sometimes nearly straight. Posterior extremity nar-
rowly or broadly rounded. Cardinal line straight, less than half the length
of the shell. Anterior end short, narrowly rounded below.

Valves moderately convex posteriorly, gibbous in the middle and umbonal
region.

Beaks anterior or sub-anterior, small, closely appressed, rising but little
above the hinge-line. Post-umbonal slope rounded or sometimes sub-angular,
extending to the post-inferior extremity.

Surface marked by fine concentric striae, and at somewhat regular inter-
vals by sharp, lamellose striae. Interior unknown.

Eight specimens measure respectively 46, 46, 45, 43, 38, 35, 32 and 32
mm. in length, and 24, 18, 20, 20, 16, 16, 15 and 14 mm. in height.

This shell evidently belongs to the Lithophagi, but is not referable to any
known genus. The specimens are extremely variable in proportions, as shown
by the measurements, but are usually easily recognized by their sub-cylindrical
form and the distant lamellose elevated striae, which make a regular curve over
the posterior portion of the shell, turning forward to the cardinal line. This
character of surface somewhat resembles Macrodon, but the absence of radiat-
ing striae and the short cardinal line are distinguishing characters.

Formation and localities. In the Chemung group, near Elmira and Ithaca ; in
Lindley township, Steuben county, N. Y. ; and in Sullivan, Tioga and Brad-
ford counties, Pa.

408 PALAEONTOLOGY OF NEW YORK.

Spathella ventricosa.

PLATE LXVI. FIGS. 41, 42

Oiikmiota milrinKia, Wiiitk ami Whiti-iki,I). Proc. Boa. Soc. Nat. Hist., vol. viii, p. 297. 1862.
SiiugiihioliltK rtulriitixtm (W. an<l W.), S. A. Millkr. Cat. Am. Pal. Foss., p. 2"3. 1877.
Ill part " " " Hall. Pal. N. Y., vol. v, pt. 1. Plates ami Explanations : PI. 66,

tiffs. 36-42. 1883.

Sheli, of medium size, elongate, siil)-cyliiidrical, widest behind ; lengtli more
than twice the height ; basal margin nearly straight, scarcely arcuate in the
middle, curving into both extremities. Posterior extremity abruptly rounded.
Cardinal line nearly straight, about half the length of tlie shell, parallel to
the basal margin. Anterior end very short, abruptly rounded below.

Valves very convex, gibbous along the middle and in the umbonal region.

Beaks anterior, not prominent, small and closely incurved. Post-umbonal
slope rounded, gibbous.

Surfiice marked by fine concentric striae, which are fasciculate, or sub-
lamello.se, upon the umbonal and posterior regions. Interior unknown.

The two specimens described measure respectively 2G and 35 ipm. in
length, and 12 and 16 mm. in height.

This species resembles the preceding, in many respects, but the anterior end
is .shorter, the valves are more gibbous in the anterior portion, and the lanielli-
form stria? are not so strongly m.arked.

Formation and locality. In the Yellow sandstones, at Burlington, Iowa.

LAMELLIBRANCHIATA. 409

CONOCARDIUM, Bronn. 1835.

CONOCARDIUM CUNEUS.

PLATE LXVll, KIGS 1 3J ; I'LATE LXVIII, FIGS. 1, 4-16; AND PLATE XCIV, FIGS. U, 12.

PleimirhyHchm nmeiis, CoyHAj). Geol. Surv. N. Y., Ann. Rep., p. 206. 1840.
Comx-ardium cuiteux (Cosvlw), S. A. Mii.lkr. Cat. Am. Pal. Foss., p. 187. 1S77.

" " " H.\LL. Pal. N. Y., vol. V, pt. 1. Plates and Explanations ; PI. 67, figs. 21-

27, 29-32. 1883.
Pletiri>rJiynchiiJi atUiiiuiius, CosRAD. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 253. 1.S42.
Conocardinm attenuatum (Conrad), S. A. Millkr. Cat. Am. Pal. Foss , p. 187. 1877.

■' " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 67, tigs.

1-11. 1883.
■ Pleumrhynchus Mgonaliis, Hall. Geol. Surv. N. Y., Rep. Fourth Dist., p. 171, t. 67, tigs. 6, 6a. 1843.
Conocardinm trigmiale (Hall), S. A. Miller. Cat. Am. Pal. Foss., p. 187. 1877.

" " " Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 67, fig. 28; pi. 68,

tigs. (1?), 4-16. 1883.
ConiK-ardium, naxutum, Yi.Ki.h. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI 67, tigs. 12-20. 1883.
Bilobites, Dk Kay.* Ann. Ly. Nat. Hist. N. Y., vol. i, p. 45, pi. 5, figs. 1-4. 1824.

Shell large, angularly sub-ovate, or trigonal in outline ; length less than twice
the height ; basal margin gently curving from the post-inferior extremity to
the anterior end. Posterior extremity abruptly truncate, produced into a
tubular extension along the cardinal line. Cardinal line straight, margins
inflected toward the anterior end. Anterior end more or less rapidly atten-
uate, with the margins gaping before reaching the extremity.

Valves gibbous.

Beaks sub-central, vertical, prominent and closely incurved over the hinge-
line. Umbonal slope angular, usually strongly defined, extending to the post-
inferior extremity. Post-cardinal slope flat or concave.

Test thick, composed of two distinct layers. Surface marked by numer-
ous radiating plications and intermediate arching lamellose, concentric striga
on the bo<ly of the shell. The posterior slope is ornamented by curving
radii, extending from the beak to the posterior margin, with the interspaces
marked by transverse lamellose stria). From the entire periphery of the
umbonal ridge there extends a finely striated expansion of the shell, which
increa.ses in extent from the beaks downward, and in old shells is supported
anteriorly by a thickening of the shell along the basal margins, which often

* Note on the Or^nic Remains termed Bjlobites, from the CatskiU Mountains. By J. E. Db Kay, M. D.
Read October 13, 1823.

410 PALEONTOLOGY OF NEW YORK.

obliterates the radii. At the junction of these thickened portions, along the
base of the valves, the shell is excavated, leaving a tubular opening extend-
ing backward from the post-inferior extremity, as shown in figs. 27, 29 and
52 of plate Ixvii, and more fully in fig. 1 2 of plate xciv.

Valves crenulated along their margins. Anterior muscular impressions
elongate, deeply impressed, narrower behind.

Four specimens measure respectively 60, 47, 43 and 21 mm. in length,
and 30, 33, 26 and 13 mm. in height.

This species resembles C. normale, in the Hamilton group, but that form is
usually more elongate with uniform simple ribs, and the interradial spaces are
marked by fine radiating striae.

The specimens here referred to a single species are subject to great variation
in form and general aspect. The main differences are indicated in the follow-
ing varietal designations :

Var. aifenuatum, Conrad. PI. 67, figs. 1-11. The specimens referred to this
form are apparently the young of C. cuneus, preserving numerous uniform,
fine radii upon the surface and the posterior extremity not abruptly
truncated. Specimens having these characters, as they become larger,
show a duplication of the radii and gradually assume the character of
C. cuneus.

Var. trigonale, Hall. PI. 67, fig. 28; pi. 68, figs. 1, 4-16; pi. 94, fig. 11.
This name is given to the specimens occurring in the Corniferous limestone
and originally described as a distinct species.

Var. nasutum, Hall. PI. 67, figs. 12-20. This name is applied to short,
triangular forms, which are broad and abruptly truncated behind, abruptly
contracted in front, with the anterior end nasute. The body of the shell
is marked by fewer radii than in characteristic forms of C. cuneus.

Formations and localities. In the Schoharie grit, at Schoharie, and tlie Hel-
derberg mountains, and on the outcrop of the same formation in the neighbor-
hood of Rondout, Ulster county, and in Orange county, N. Y. ; in the Cornif-
erous limestone, at Williamsville, N. Y. ; at Dublin and Columbus, Ohio ; and
at the falls of the Ohio river. It also occurs at Cayuga and other places in
Canada West.

The species, in its varieties of form, occurs "at Pendleton, Indiana, in a sand-
stone which probably represents the horizon of the Schoharie grit,

LAMELLIBRANCHIATA. 411

. CONOCARDIUM OhIOENSE.

PLATE LXVIII, FIGS. 2, 3.

Conocardium Ohioenxe, Meek. Proc. Acad. Nat. Sci., Phila., p. 9. 1871.

" " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 68, tigs. 2, 3.

1883.

Shell small, ovate, sub-trigonal, ventricose behind the middle of its length ;
length one-third greater than the height. Posterior end prominent, pro-
duced in the middle and sloping abruptly to the post-cardinal angle. Ante-
rior end abruptly contracted in front of the middle and prolonged, nasute,
with the extremity narrowly rounded.

The body of the shell is marked by about six strong radiating plications
on the ventricose portion of the valve, and on each side by more numerous
and smaller plications. The interspaces between the ribs are marked by
lamellose concentric striae.

A specimen of this species has a length of 15 mm. and a height of 10 mm.

This species differs from C. cuneus in being more narrowly ventricose, and
the body of the shell marked by fewer plications, with a distinct constriction
in front ; the umbonal slope is more rounded and less oblique, while the poste-
rior extremity is more produced than in the usual forms of C. cuneus and C.
trigonale.

Formation and localities. In the Corniferous limestone, near Columbus, Ohio,
and at the falls of the Ohio river.

CONOCABDIUM NORMALE.

PLATE LXVIII, FIGS. 17-19.

Conocardium nonnale. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 68, tigs. 17-19. 1883.

Shell large, sub-ovate, trigonal ; length about twice the height ; basal margin
regularly curving. Posterior extremity obliquely truncate. Cardinal line
straight. Anterior end narrow, nasute.

Valves ventricose, abruptly contracted anteriorly and truncate behind.

Beaks posterior to the center, prominent, strongly incurved. Umbonal

412 PALEONTOLOGY OF NEW YORK.

slope angular, continuing to the post-inferior margin. Post-cardinal slope
concave.

Test thick, body of the shell marked by numerous radii, between which
are undulating lamellose concentric stride. When the shell is exfoliated the
nulii liecome stronger and the intermediate surfjice is marked by fine radiiit-
ing strisB. With the growth of the shell the anterior rays become greatly
strengthened and semi-tubular.

The cast of the foot-sheath is bilobed, and doubly pointed behind.

Two specimens measure respectively 50 and 60 mm. in length, 25 and 32
mm. in height, and 26 and 30 mm. in the depth of both valves.

This species bears a close resemblance to the elongate forms of C. cuneus.
There is, however, no tendency to a duplication of the ribs, which is a common
feature in the specimens from the Schoharie grit.

Formatum and locality. In the shales of the Hamilton group, near Cumber-
land, Md.

CONOCARDIUM EbOBACEOM.

PLATE LXVIII, FIGS. 20-23.

Cunocardium Eboraceum, Hall. Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 91. I860.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. «8, figs. 20-23.

1883.

Shell small, sub-ovate ; length less than twice the height ; basal margin gently
curving. Posterior end obliquely truncate. Anterior end abruptly con-
tracted, nasute, gaping.

Valves ventricose in the middle.

Beaks a little anterior to the middle, incurved. Umbonal slope angular,
and just within the cardinal slope the shell is marked by five or six angular
radiating ribs. The central portion of the post-cardinal slope is unknown.

Test thick. Body and anterior portion of the shell marked by obscure
plications and by strong, concentric, reflexed lamellose striae. The radii are
continued beyond the concentric laminae at the margin, as strong interlock-
ing denticulations.

In well-preserved specimens the concentric laminae from the umbonal

LAMELLIBRANCHIATA. 413

angle to the anterior end are very strong and elevated, obscuring the radii.
Interior unknown.

All the specimens known are much distorted by pressure, and the entire
characters cannot be determined.

One specimen has a length of 19 mm. and a height of 9 mm. A large
specimen measures 25 mm. in length.

Formation and locality. In the shales of the Hamilton group, at York, Living-
ston county, N. Y.

CONOCARDIOM DENTICULATUM.

PLATE I.XVni, FIGS. 24, 35.

Cortocardium denticulatuin. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 68, figs. 24, 25.

1883.

Shell small, ovate-cuneate ; basal margin straight. Body gibbous, truncate
behind, abruptly contracted and attenuate in front.

Body of the shell marked by five or six strong angular radii ; those of the
post-cardinal slope unknown. The anterior end is cancellated by fine radii
and lamellose concentric striae. The interspaces between the strong radii
are marked by fine concentric striae. Anterior portion of the shell gaping,
the margins of the valves furnished with distant lamelliform denticulations.
Interior unknown.

The fragment described has a length of 10 ram. and a height of about 5 mm.

This form differs from C. Eboraceum in the strong angular radii upon the
body of the shell ; the post-cardinal area is smaller and the anterior portion
more contracted and attenuate, with much finer radiating and concentric strise.

Formation and locality. In the shales of the Hamilton group, at York, Liv-
ingston county, N. Y.
53

414 PALEONTOLOGY OF NEW YORK.

CONOCARDIUM CONCINNUM.

PLATE LXVm, FIGS. 26, 27.

CbMOOordiNm ooncinnttm. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 68, figs. 26, 27.

1883.

Shell small, ovate-cuneate, gradually attenuate anteriorly. Posterior end
obliquely truncate along the umbonal angle. Post-cardinal slope slightly
concave and projecting at the junction of the valves. Valves marked by
numerous radii. Body of the shell, to near the anterior extremity, marked
by strong sub-equal radii, as preserved in the cast of the interior.

This species is not very different in appearance from C. attenicatum, but the
ribs are coarser.

Formation and localities. In the calcareous layers of the Hamilton group, at
Pratt's falls, Onondaga county, N. Y. ; and in the arenaceous beds of the same
group, from an unknown locality.

CONOCARDIUM LIRATUM.

PLATE LXVin, FIGS. 28, 29.

Qmoeardium liratuin. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 68, figs. 28, 29. 1883.

Shell small, trigonal ; length less than twice the height. Posterior slope very
broad, marked by about five sharp, distant, elevated plications. Anterior
part of the body abruptly contracted and marked by about twelve or more
finer plications. The entire surface is also marked by fine lamellose concen-
tric striae. Interior unknown.

A specimen has a length of 11 mm. and a height of 6 mm.

In general form this species resembles C. denticulatum, but is readily distin-
guished by the strong plications on the anterior portion.

Formation and locality. In the Chemung group, Ithaca, N. Y.

LAMELLIBRANCHIATA. 415

CONOCARDIUM RELIQUUM.

PLATE LXVIII, FIG. 33.

Cmiocardium reliquum. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 68, fig-. 33. 1883.

The specimen is the impression of the posterior end, marked by fine radii.
The original specimen is not accessible for description. A cast from the origi-
nal is recorded as coming from the Chemung group. Locality unknown.

CONOCARDIUM TEGULUM.

PLATE LXVIII, FIGS. 30, 31.

Cunocardium tegulum. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 68, figs. 30, 31. 1883.

The original specimen is not accessible for description. The figures illustrate
all that is known regarding its characters. The specimen is recorded as from
the Niagara group. Locality unknown.

CONOCARDIUM INCEPTUM.

PLATE UCVIII, FIG. 32.

Gmocardiwn ineeptum. Hall. Pal. N. Y., vol. iii, p. 491. 1859.

" rttgotum, " Pal. N. Y., vol. v, pt. 1. Plates and Exjilanations ; PI. 68, fig. 32. 1883.

Shell small, sub-ovate. Body of the shell gibbous or ventricose, marked by
six or seven strong rounded plications. Posterior extremity truncate, its
special characters unknown. Anterior end short, gaping; inner margin
marked by a few strong denticulations. Surface of the anterior portion can-
cellated by fine radiating and concentric striae, the latter extending over the
strong plications and marking the interspaces.

In the general surface characters it is very similar to C. denticulatum, but
the anterior end is comparatively shorter and more abruptly contracted at
the extremity ; the ribs on the body of the shell are more rounded.

The specimen described has a length of 20 mm.

Formation and locality. In the shaly limestone of the Lower Helderberg
group, Albany county, N. Y.

416 PALAEONTOLOGY OF NEW YORK.

PAN EN K A, Barrande. 1881.
Panenka dichotoma.

PLATE LXX, FIG. 21 ; AND I'LATE XCIV, FIG. 13.
Cardiolaf dichotoma, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, fig. 21. 1883.

Shell large, obliquely ovate ; length a little greater than the height. Pallial
margin curving very regularly from the anterior to the post-inferior extrem-
ity and then more abruptly returning to the hinge-line. Anterior end short ;
posterior end more extended.

Valves of moderate convexity in the lower portion, becoming gibbous in
the middle and above.

Hinge-line short and straight.

Beaks prominent, strongly incurved, turning distinctly forward.

Surface marked by numerous prominent, radiating plications, which fre-
quently bifurcate. Interior unknown.

Two specimens measure respectively 65 and 70 mm. in length, and 65
and 67 mm. in height.

This species bears considerable resemblance to P. robusta of the Portage
group, and was formerly recognized as the same, but the beaks ai"e more prom-
inent than in that species, the radii are more closely arranged and frequently
bifurcating, while in that one they are essentially simple.

Formation and localities. In the Schoharie grit in Albany and Schoharie
counties, N. Y.

Panenka alternata, n. sp.

Shell very large, broadly ovate; length a little greater than the height.
Anterior end short.

Valves moderately convex, becoming gibbous in the umbonal region.

Hinge-line short. Ligamental area narrow, visible beneath and posterior
to the beak.

Beaks strong, incurved, turning slightly forward.

LAMELLIBRANCHIATA. 417

Test marked by numerous sub-angular radii; on the umbo, each third
or fourth one being stronger than the others, becoming equal and rounded
below.

The specimen described has a length of about 110 mm. and a height of
97 mm.

This species is distinguished by its large size, moderate convexity and the
alternation of the radii in the umbonal region.

Formation and locality. In the Corniferous limestone, near Columbus, Ohio.

Panenka multiradiata, n. sp.

PLATE LXIX, FIG. 5; AND PLATE XtIV, FIG. 18.

In part Cardiola raiUmui (Cokrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanaticma : PI. 69, figs.

5-11. 1883.

Shell large, sub-circular or broadly ov.ate ; length greater than the height.
Pallial margin regularly rounded from the anterior to the middle of the
posterior end, whence it is a little more abruptly curving to the post-cardi-
nal extremity. Anterior end short and regularly rounded. Posterior end
expanded.

Valves regularly convex below, becoming gibbous or ventricose in the
middle and above.

Hinge-line short, straight. Ligamental area short and high.

Test thin. Surface marked by numerous, closely arranged, flattened or
convex radii.

The specimen described has a length of 65 mm. and a height of 57 mm.

Formation and locality. In the limestone of the Upper Helderberg group, at
Clarence Hollow, Erie county, N. Y.

Panenka ventricosa.

PLATE LXIX, FIGS. 1, 2.

Cardiolaf elevata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 69, figs. 1, 2. 1883.
Not Mcmntii elevata, Conrad. Proc. Acad. Nat. Sci., Phila., vol. iii, p. 23. 1846.

Shell of medium size or larger, sub-circular ; length greater than the height.
Pallial margin regularly curving. Anterior end large.

418 PALEONTOLOGY OF NEW YORK.

Valves regularly convex below the middle, becoming ventricose above.
Hinge-line straight. Ligamcntal area short and high.
Beaks sub-central, elevated, prominent and incurved.
Surface marked by very numerous fine and closely arranged flattened
radii, and by very fine concentric striae. Interior unknown.

The specimen described has a length of 48 mm. and a height of 42 mm.

This species is distinguished by its extreme ventricosity of the valves, prom-
inent beaks and finely radiated surface.

Formatim and locality. In the Goniatite limestone of the Marcellus shale,
Schoharie county, N. Y.

Panenka Hero.

PLATE LXIX, FIG. 3.
Carduilaf Heti>, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 69, fip. 3. 1883.

Shell small, sub-circular ; length a little greater than the height. Pallial mar-
gin regularly rounded.

Valves moderately convex.

Hinge-line short. Ligamental area narrow.

Beaks sub-central, small, pointed and incurved.

Surface marked by strong rounded or sub-angular plications, some of which
q,re duplicate. The plications are direct on the anterior portion of the shell
and curving on the posterior. Interradial spaces about equal in width to
the radii. Entire surface also marked by fine undulating concentric striiB.
Interior imknown.

One specimen has a length of 32 mm. and a height of 29 mm.

This species differs from any other in the strong elevated distant radii, and
in its small pointed beaks.

Formation and localities. In the Marcellus shale, on the Indian Reservation,
near Buff'alo, and in the same horizon near West Avon, N. Y.

LAMELLIBRANCHIA TA.

419

Panenka equilatera.

PLATE LXIX, FIG. 4 (7 ?) ; AND PLATE XCIV, FIG. 17.
Cardiola* equilatera. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 69, fig. 4. 1S83.

Shell of medium size, sub-circular; length a little greater than the height.
Pallial margin regularly rounded.

Valves convex below, gibbous in the middle and above.

Hinge-line short. Ligamental area well-defined, not high.

Beaks sub-central, elevated, turning forward, incurved.

Surface marked by from forty to fifty simple strong radii with equal inter-
spaces ; radii rarely bifurcating. Also marked by fine, close, concentric
striae.

Two specimens measure respectively 34 and 35 mm. in length, and 30 and
31 mm. in height.

This species has about the same size and proportions as P. Hero, but the ribs
are much more numerous and not so strongly elevated.

Formations and localities. In the Marcellus shales at Avon ; and in the Ham-
ilton group at Pratt's falls, Onondaga county, N. Y., and doubtfully from Cum-
berland, Md.

Panenka costata, n. sp.

PLATE XCIV, FIG. 15.

Shell large, broad-ovate ; length about one-fifth greater than the height. Pal-
lial margin regularly rounded in front and on the base, expanding behind.

Valves very ventricose in the iniddle.

Hinge-line short.

Beaks sub-central, prominent, incurved.

Surface concentrically striated, and marked by strong rounded or some-
what flattened costae with narrower interspaces. The radii curve distinctly
forward on the anterior portion of the shell. Interior unknown.

One specimen has a length of 51 mm. and a height of 42 mm.

420 PALEONTOLOGY OF NEW YORK.

This species differs from P. Hero in the more numerous, more rounded and
more closely arranged radii.

Formation and locality. In a limestone of the Marcellus shale, Stafford, Gen-
esee county, N. Y.

PaNENKA LiNCKLiENI.

PLATE LXIX, nUS. 12-14.

Cardtola Liiu-kUBni (Hall), S. A. Millkr. Cat. Am. Pal. Foss., i>. 18G. 1877.

" f " " Pal. N. Y., vol. V, pt. 1. Plates and Explanatiorhs : PI. 69, figs. 12-14. 1883.

Shell large, sub-orbicular or broadly ovate ; length about one-fourth greater
than the height. Pallial margin regularly curving, somewhat flattened along
the base and extended posteriorly.

Valves moderately convex below, gibbous in the middle and above. The
specimens usually occur in the soft shale and are extremely flattened.

Hinge-line short.

Beaks sub-central, elevated, directed forward and incurved.

Surface concentrically striated and marked by about thirty, broad, flattened,
radiating plications, with sometimes intermediate smaller ones, which arise
upon the umbo and continue to the basal margin. The intermediate radii
are sometimes confined to the anterior and posterior portion of the shell, but
often occupy the entire disc.

Three specimens measure respectively 63, 84 and 96 mm. in length, and
52, 63 and 73 mm. in height.

This species is distinguished for its large size, and broad, flattened radii.
Formation and- localities. In the Marcellus shale, Flint creek, near Phelps,
Ontario county, the Indian Reservation near Buffalo, and at Avon, N. Y.

Panenka mollis, n. sp.

PLATE LXXX, FIGS. 8 (9?).
Oardiolaf , Hall. Pal. N. Y., vol. v, pt. I. Plates and Explanations : PI. 80, dg. 8. 1883.

Shell of medium size, broadly obovate, length and height nearly equal. Pallial
margin regularly rounded, a little truncate on the posterior slope.

LAMELLIBRANCHIATA. 421

Valves moderately convex below, gibbous in the middle and above.

Beaks prominent, attenuate.

Surface marked by fine, undulating concentric striae and by about forty-
five rounded radii, with narrow interspaces. Some of the radii become less
conspicuous and duplicate upon the posterior slope.

The specimen described has a length, in its compressed condition, of about
28 mm. and a height of 31 mm.

In form this species is similar to P. retusa, but the shell is less oblique, the
posterior slope longer and the radii are more direct.

Formation and locality. In the Marcellus shale ; precise locality unknown.

Panenka retusa, n. sp.

PLATE LXIX, FIG. 6.

In part Cardiolaf radians (Cosrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 69,

figs. 5-11. 1883.

Shell of medium size, obovate, oblique ; length nearly equal to the height.
Pallial margin regularly curving.

Valves moderately convex below and in the middle, becoming gibbous in
the umbonal region.

Hinge-line short, straight. Ligamental area distinct.

Beaks sub-central, small, curving forward, not prominent.

Surface concentrically striated, and marked by about thirty-five moderately
rounded, curving plications, with somewhat narrower interspaces.

The specimen described has a length of 30 mm. and a height of 31 mm.

This species is distinguished by its broad obovate form, its sub-equal length
and height, and by its regular curving simple plications.

Formation and locality. In the shales of the Hamilton group on the shore of
Cayuga lake, N. Y.

54

422 PALAEONTOLOGY OF NEW YORK.

Panenka potens, n. sp.

PLATE LXIX, FIGS. 8, 10.

In part Oardiolaf radians (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 09,

figs. 5-11. 1883.

Shell large, obliquely broad-ovate ; anterior end expanded ; length greater
than the height. Pallial margin regularly curving along the posterior end,
a little truncate on the base and more narrowly rounded in front.

Valves moderately convex below, becoming gibbous or ventricose in the
middle and above.

Hinge-line one-third the length of the shell. Ligamental area long and
narrow.

Beaks large, prominent and incurved over the hinge-line.

Surfjice concentrically striated and marked by from thirty-five to forty
rounded, rarely duplicate plications, with narrower or sub-equal interspaces.

A specimen has a length of 80 mm. and height of 64 mm.

This species differs from P. radians in its more ovate, less nearly equilateral
form, and in the more simple radii.

Formation and localities. In the shales of the Hamilton group at Cazenovia
and other localities in Madison county, N. Y.

Panenka radians.

PLATE LXIX, FIG 9.

PUrinea radiaim, Comrad. Jour. Acad. Nat. Sci. Phila., ]). 252. PI. 1.5, fig. 1. 1842.
Monotis radiatm (Conrad), 8. A. Millkr. Cat. Am. Pal. Foss., p. 196. 1877.
Cardiola radiann (Hall), S. A. Millbr. Cat. Am. Pal. Foss., p. 186. 1877.

In part Oardiolaf radians (Conrad), Hall. Pal. N. Y., vol. v, pt. 1 Plates and Explanations: PI. 69,

figs. 5-11. 1883.

Shell large, brofidly ovate or sub-circular; length greater than the height.
Pallial margin regularly curving, broader anteriorly.

Valves moderately convex in the lower portion, becoming gibbous in the
umbonal region.

Ligamental area narrow.

LAMELLIBRANCHIATA. 423

Beaks sub-central, moderately prominent and incurving over the hinge-
line.

Surface marked by fine, closely arranged, undulating concentric striae, and
by from forty to forty-five rounded or somewhat flattened radii, which are
frequently duplicating on the anterior and posterior slopes. Interspaces nar-
rower than the plications.

A specimen has a length of 55 mm. and a height of about 42 mm. The
original figure given by Mr. Conrad has a length of 65 mm. and a height of
51 mm., and is a good representation of the species.

In form this species more nearly resembles P. Lincklczni than any other, but
the plications are much more numerous. It differs from P. potens in its more
rotund form and in the duplication and outward curvature of the plications on
the anterior portion of the valve.

Formation and localities. In the coarser shales of the Hamilton group at Caz-
enovia, and at Pratt's falls, N. Y.

Panenka abrupta, n. sp.

PLATE LXIX, FIG. U ; AND PLATE XCIV, FIG. 16.

In pai-t CardiolaJ radians (Cohbad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. G9,

tigs. 5-11. 1883.

Shell of medium size, obovate, broadest below, rapidly tapering above the mid-
dle ; length and height nearly equal in the cast. Pallial margin regularly
curving from the posterior along the basal margin, and somewhat straighter
upon the posterior slope.

Valves gibbous in the middle and above.

Ligaraental area distinct with an oblique fold under the beak.

Beaks sub-central, abruptly attenuate, elevated.

Surface marked by concentric striaa and by about thirty radii ; those upon
the body of the shell being strong, sub-angular and wider than the inter-
spaces. The plications sometimes show a tendency to bifurcation and inter-
stitial addition.

424 PALEONTOLOGY OF NEW YORK.

Two specimens measure respectively 35 and 40 mm. in length, and 35 and
38 mm. in height.

In form this species somewhat resembles P. equilatera, but the beaks are more
al>ruptl\- attenuate, and the radii are much stronger and more prominent, with
comparatively wider interspaces.

Formation and locality. In the shales of the Hamilton group, near Cumber-
land, Md.

Panenka degener, n. sp.

PLATE XCIV, FIG. 14.

Shell of medium size, broadly obovate ; length and height nearly equal. Pal-
lial margin regularly curving, somewhat obliquely truncate on the posterior
side.

Valves regularly convex, scarcely gibbous.

Beaks prominent, elevated and strongly incurved.

Surface marked by extremely fine, closely arranged concentric striae, and
by about forty-five nan-ow angular radii, which are less defined on the pos-
terior slope. Interspaces wider than the radii.

The specimen described has a length of about 40 mm.

This species is distinguished by its narrow, sharp, abruptly elevated radii.
Formation and locality. In the shales of the Hamilton group, at Pratt's falls,
Onondaga county, N. Y.

Panenka robusta.

PLATE LXX, FIGS. 22-24.

Ill part Cardinptu robvjtta (Hall), S. A. Millkh. Cat. Am. Pal. F().s.s , p. 186. 1877.

Cardiolaf robusta, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 70, figs. 22-24. 1883.

Shell large, obliquely obovate ; length somewhat greater than the height.
Pallial margin vertical to the hinge-line in front, thence more regularly curv-
ing around the base to the posterior extremity. Post-inferior extremity
extended.

LAMELLIBRANCHIATA. 425

Valves moderately convex below, becoming gibbous in the upper and
umbonal regions.

Beaks at about the anterior third, prominent and incurved.

Surface marked by closely arranged, undulating, concentric striaB, and by
about forty strong elevated sub-angular radii, which are narrower than the
interspaces. Several of the rays on the posterior slope are bifurcating.

The two specimens described measure respectively 62 and 63 mm. in
length, and 57 and 60 mm. in height.

This species resembles P. dichotoma (which is not well represented in fig. 21,
plate Ixx), but is distinguished by its more elevated and more angular plications,
a few of which only are bifurcate on the posterior slope, while in that species
they frequently bifurcate or trifurcate.

Formation and locality. In the Portage group, in the Genesee valley, below

Portage, N. Y.

In the Proceedings of the Academy of Natural Sciences of Philadelphia,
vol. iii, 1846, p. 23, Mr. Conrad has described two species referable to the
genus Panenka. They were described under the genus Monotis, and the pre-
viously described species, Pterinea radians, was there referred by Mr. Conrad to
the same genus. Panenka radians (Pterinea radians, Conrad), coming from the
Hamilton shales, in the State of New York, has been recognized and is described
and illustrated in the present volume, vide ante.

The following are the original descriptions as given by Mr. Conrad :
Panenka Poulsoni (Monotis Poulsoni, Conrad).

" Sub-orbicular, ventricose, not oblique, ribs about 44 in number, obtusely
rounded, interstices nearly flat, about as wide as the ribs, with minute trans-
verse wrinkles ; umbo broad and the summit prominent ; anterior and poste-
rior margins rounded.

" Locality. Jersey shore, Lycoming county, Pennsylvania. (Devonian shale.)

" This beautiful species occurs in a dark shale of the same geological age and
appearance as the shale of the Chemung Narrows in New York, which is a part
of the Devonian System."
Panenka elevata (Monotis elevata, Conrad).

" Obliquely oval, somewhat ventricose, ribs about 42 in number, prominent,
acutely rounded, interstices very narrow, except towards the anterior hinge
margin, where the ribs are larger; anterior and posterior margins nearly
straight ; anterior side very short.

" Locality. Occurs with the preceding species in the same rock."

426 PALEONTOLOGY OF NEW YORK.

GLYPTOCARDIA, n. o.
Glyptocardia speciosa.

PLATE LXX, FIGS. 2-» ; AND I'LATE LXXX, FIG. 10.

Avicula speciosa, Hall. Geol. Sui-v. N. Y., Rep. Fourth Dist., p. 243, t. 106, figs. 1, la. 1S43.
Cardiola speciosa (Hall), 8. A. Millkk. Cat. Am. Pal. Foss., p. 186. 1877.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 70, figs. 2-9. 18t^3.

Compare Venericardiuia retrostriatum, v. Been. Ueb. Ammon, p. 50. 1832.

" Oardioia refrusirjoto (v. Bucu), Kkyskrling. Petschora-Land, p. 254, pi. 11, fig«. 3-3c. 1846.
" " " " Sandbergbr. Vei-stein. Nassau, p. 270, pi. 28, figs. 8, 9, 10. 1850-

1856.
" " t " " var. Boheinica, Barrande. Syst. Sil. Bohfime, pi. 181, fig. II,

1-10. 1881.
" Cardium retrostriatum, " Qbinitz. Grrauwackenform. in Sachsen, 11, s. 47, taf. 12, fig. 7.
" " palmatum, Goldfuss. Peti-ef. Germ., p. 217, t. 143, fig. 7. 1837.

"' " " " F. A. RcKMBR. In Dunker and Von Meyer, Pateontographica,

B(l. Ill, a. 26/, taf. 4, figs. 11, 12. 18!)0.

Shell small, broadly elliptical or sub-circular, sometimes broadly obovate ; length
about one-fourth greater than the height; basal margin regularly curving,
somewhat obliquely truncate from the beak to the posterior extremity.

Valves regularly convex below, becoming gibbous in the middle and
descending thence to the beaks.

Beaks anterior to the middle, closely incurved and directed forward.

Surface marked by from twelve to fifteen plications ; those on the body of
the shell broad, flattened along their upper surface and sculptured by promi-
nent arching lamellose striae, which are sometimes raised into nodes. The
interspaces are finely, and inconspicuously, transversely striated.

Numerous specimens measure 7 mm. in length and 5 mm. in height. The
smallest specimen observed has a length of 3.5 mm. and a height of 2.5 mm.
The largest individual in the collection has a length of 10 mm.

The specimens are subject to considerable variation in form, chiefly owing
to the direction of the pressure from the enclosing matrix. The plications
also vary in width and prominence, and in the degree of sculpturing.

This species has a wide range in New York, occurring in the Hamilton
group, Genesee slate, Portage and Chemung groups. It is probably identical

LAMELLIBRANCHIATA. 427

with the Cardiola retrostriata (von Buch) of various authors, and with Cardium
palmatum of Goldfuss. Its citation by numerous authors shows its wide distri-
bution in Europe.

Formations and localities. In the shales of the Hamilton group near Geneva,
Ontario county; Sherburne creek, Chenango county, and on the shores of
Cayuga lake. In the Genesee slate at Bristol, Ontario county, and numerous
other localities. In the Portage group at Branchport, Yates county ; and at
Ithaca, Tompkins county, N. Y.

PRiECARDIUM, Barrande. 1881.
Pr^cardium vetustum.

PLATE LXX, FIGS. 18-20.

Ccardiwmf vetuxtmii. Hall. Geol. Surv. N. Y., Rep. Fourth Dist., p. 245, t. 107, fig. 2. 1843.
Cardiola vetiuta (Hall), 8. A. Millbr. Cat. Am. Pal. Foss., p. 186. 1877.

PrcBcardium retiuitum, H&LU Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, figs. 18-20. 1883.
Compare " dexpectum, Barrandb. Syst. Silur. de Boh4me, vol. vi, pi. 285, III, figs. 5-8. 1881.

Shell small, trigonal, arcuate, oblique ; length greater than the height. Ante-
rior margin concave, becoming rounded below ; basal margin gently curved.
Posterior margin contracted below, and obliquely truncate above.

Valves moderately convex below, becoming gibbous in the umbonal region.

Hinge-line declining posteriorly.

Beaks anterior, prominent and strongly incurved.

Surface marked by fine concentric striae and by from ten to fourteen strong
elevated flattened radii, which show a tendency to duplication on the ante-
rior end. Interspaces flat, as wide or wider than the radii.

Three specimens measure respectively 17, 17 and 16.5 mm. in length, and
14, 10.5 and 13 mm. in height.

This is a smaller species, but very similar to Pmcardium despectum, of Bar-
rande, loc. cit.

Formation and hcality. In the shales of the Portage group on the shore of
lake Erie, near Portland Harbor, N. Y.

428 PALEONTOLOGY OF NEW YORK.

PARACARDIUM, Barrande. 1881.
Paracardium Doris.

PLATE LXX, FIGS. 10, 11.
Girdiola Doris, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Exi)lanation8 : PI. 70, figs. 10, 11. 1883.

Shell minute, broadly ovate ; length and height nearly equal. Pallial margin
regularly curving, except on the posterior slope, which is sub-truncate.
Valves gibbous in the middle and above.
Beaks anterior to the centre, prominent, incurved.
Siu"face marked by numerous fine radii, with narrow interspaces.
A specimen has a length of 3.5 mm. and a height of 4 mm.

This form is similar to several species of the genus illustrated by Barrande.
The figures given on plate Ixx do not properly represent the form of the spe-
cies.

Formation and locality. In the soft shales of the Portage group, at Shakers'
Mill, Cashaqua creek, N. Y.

LAMELLIBRANCHIATA. 429

PARARCA, N. G.

[ Types P. transversa, P. veiiusta, P. Sao and P. erecta. ]

PaRARCA PRiECEDENS.

PLATE XCIV, FIG. 19.

Shell of medium size, broad-ovate, narrowing posteriorly ; length one fourth
greater than the height; basal margin regularly curving. Posterior extrem-
ity rounded. Cardinal line straight and apparently slightly declining poste-
riorly. Anterior end declining rapidly from the beak and regularly rounded
below.

Valves moderately convex below, becoming gibbous in the middle and
above.

Beaks at about the anterior third, prominent. Post-umbonal slope prom-
inent, extending to the posterior extremity.

Surface marked by numerous, fine rounded radii, with narrow interspaces.

The specimen described has a length of 31 mm. and a height of 24 mm.

This species diifers from P. neglecta in its larger size, more elevated beak and
finer striae ; the radii upon the anterior slope are notably much finer than in
that species. The species is described from a gutta-percha impression of the
natural mould.

Formation and locality. In the cherty layers of the Corniferous limestone, in
Cayuga, Canada West.

Pabarca transversa.

PLATK LXX, FIGS. 12, U, 15.

In part Cardiola transtersa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, figs. 12-15.

1883.

Shell small, oblong, sub-elliptical; length about one-third greater than the
height ; basal margin regularly and gently curving. Posterior extremity
broadly rounded or somewhat obliquely sub-truncate. Cardinal line straight,
55

430 PALjEONTOLOGY OF NEW YORK.

more than half the length of the shell. Anterior end short, declining from
the beaks and regularly rounded in front.

Valves regularly convex below, gibbous in the middle and upper portion.

Beaks at about the anterior third, prominent, directed forward and
incurved. Post-umbonal slope gibbous, defined and extending to the post-
inferior extremity.

Surface marked by numerous fine radii, which are somewhat stronger on
the anterior end, and by fine concentric striae.

Anterior muscular impression well-marked, situated just below the lunule.

Three specimens measure respectively 22, 24 and 25 mm. in length, and
15, 15 and 16 mm. in height.

This species somewhat resembles P. Sao, but it has a smaller shell, with much
finer and more numerous radii, which are direct, and not arched as in that
species.

Formation and locality. In the sandstone of the Chemung group near Sala-
manca, N. Y., and at Alleghany springs, Warren county, Pa.

Pararca Sao,

PLATE LXX, FIG. 17.
Cardiola Sao, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, fig. 17. 1883.

Shell large, broadly elliptical ; length less than one-third greater than the
height ; basal margin regularly curving. Posterior extremity obliquely sub-
truncate. Cardinal line slightly arcuate. Anterior end short and regularly
rounded below the lunule.

Valves regularly convex below, becoming gibbous in the middle and in the
umbonal region.

Beaks sub-anterior, moderately prominent, incurved. Umbonal slope con-
vex, not strongly defined, extending in an arching direction to the post-
basal extremity.

Surface marked by numerous strong, rounded plications. Those on the
antero-basal margin are much stronger than those on the posterior half of

LAMELLIBRANCHIATA. 431

the shell. Interspaces narrower than the radii. All the plications, except
those of the anterior end, are arcuate, corresponding essentially with the
direction of the umbonal slope. Entire surface marked by fine concentric
striae of growth.

Two specimens measure respectively 45 and 50 mm. in length, and 32 and
37 mm. in height.

In form this species somewhat resembles P. transversa, but it has a much
larger shell, the radii are coarser and the umbonal slope not nearly so abrupt.

Formation and localities. In the Chemung group at Meadville, associated with
Spirifera Verneuili, and also near Uniontown, Pa.

Paraeca venusta, n. sp.

PLATE XCIV, FIG. 22.

Shell large, broadly elliptical; length less than one-third greater than the
height ; basal margin regularly and gently curving. Posterior extremity
broadly rounded. Cardinal line short, slightly arcuate. Anterior end short,
regularly rounded below the lunule.

Valves regularly convex in the lower and posterior part, gibbous in the
middle and above.

Beaks sub-anterior, not prominent. Umbonal slope not defined, the line
of greatest convexity arcuate and continuing from the beak to the post-infe-
rior extremity.

Surface marked by numerous fine rounded radii, with narrower interspaces,
the radii of the anterior end being stronger as they approach the margin of
the shell ; crossed by fine concentric lamellose striae, which, toward the mar-
gins, become fasciculate and produce stronger varices of growth.

Two specimens measure respectively 39 and 43 mm. in length, and 31 and
32 mm. in height.

This species resembles P. Sao, in general form, but is proportionally narrower
posteriorly, and marked by much finer radii.

Formation and localities. In the upper part of the Chemung group, at Warren,
Pa. ; and at Panama, N. Y., above the conglomerate.

432 PALEONTOLOGY OF NEW YORK.

Pararca neglecta, n. sp,

. PLATE LXX, FIG. 13.

In part CardMa transversa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 70, figs. 12-

15. 1883.

Shell small, broadly sub-elliptical ; length one-third greater than the height ;
basal margin regularly curved. Posterior extremity broadly rounded. Car-
dinal line straight, about half the length of the shell. Anterior end short,
regularly rounded below the lunule.

Valves depressed-convex below, becoming moderately convex in the umbo-
nal region, somewhat flattened in the middle below the centre.

Beaks at about the anterior third, low, rounded, rising but little above the
hinge-line. Umbonal slope undefined.

Surface marked by numerous fine rounded radii, which are much stronger
on the anterior end. Interspaces much narrower than the radii. Entire
surface also marked by strong, regular, undulating concentric lamellose striae.

The specimen described has a length of 23 mm. and a height of 16 ram.

This species is distinguished from P. transversa by its broader and less gib-
bous form, coarser radii, coarser and regular concentric striae, and undefined
umbonal slope.

Formation and locality. In the sandstones of the Waverly group, at Mead-
ville, Pa.

Pararca erecta.

PLATE LXX, FIG. 16 ; AND PLATE XCIV, FIGS. 20, 21.
Cardiola erecta. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 70, fig. 16. 1883.

Shell of medium size or larger, sub-rhomboidal ; length and height nearly
equal ; basal margin rounded, abruptly recurving at the post-inferior extrem-
ity. Posterior extremity gently rounded or nearly vertically sub-truncate.
Cardinal line short, less than half the length of the shell. Anterior end
short, margin nearly vertical, gently curviujg to the basal margin.

LAMELLIBRANCHIATA. 433

Valves regularly convex below the middle, becoming gibbous above, some-
what depressed-convex, along the middle, from the umbo to the basal margin.

Beaks at about the anterior third, prominent. Umbonal slope sub-angular
above, declining very abruptly to the post-inferior extremity.

Surface marked by numerous fine rounded radii, with narrower inter-
spaces. The radii on the posterior slope are slightly stronger, and those on
the anterior are much stronger than those in the middle of the valve. Entire
surface marked by strong concentric undulating striae, which become fascicu-
late, and produce varices of growth below the middle of the shell.

Ligamental area narrow. Hinge-line with numerous crenulations.

Two specimens measure respectively 29 and 38 mm. in length, and 27
and 36 mm. in height.

This species is distinguished by its erect rhomboidal form, and nearly equal
length and height. The radii are also finer than in P. venusta.

Formation and localities. In the sandstones of the Waverly group, at Warren
and Meadville, Pa.

CARDIOPSIS, Meek AND WoRTHEN. 1861.
Cabdiopsis radiata.

PLATE LXX, FIG. iS.

Cardiomarpha radiata, Mkbk and WoRXHBif. Proc. Acail. Nat. Sci., Pliila., p. 448. 1860.
CardivpgU " " Pal. Ills., vol. ii, p. 157, pi. 14, figs. 6a, 6i. 1866.

" " " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. 70, fig. 25. 1883.
Megambonia Lyoni, Hall. Thirteenth Rep. N. Y. State Cab. Nat. Hist., p. 110. 1860.

The specimen figured is from the original locality, and is the type referred
to in the description of Megambonia Lyoni. It does not appear to be congeneric
with any of the forms occurring in the New York series.

The species has much resemblance to Cardiomorpha ovata, B.ali.=: Dexiobia

OVata, WiNCHELL.*

Formation and locality. In the Kinderhook group at Rockford, Ind.

* Dualhia, Bakkakdb, 1881, is apparently identical with Dexiobia, Winchkll, 1863.

434 PALEONTOLOGY OF NEW YORK.

LUNULICARDIUM, Munster. 1840.

LUNULICARDICM FRAGILE.

PLATE LXXl, FIGS. 1-U.

Av'tculafragUix, Hah. Geol. Suiv. N. Y., Rep. Fourth Dist., p. 222, t. 94, figs. 1, 2. 1842.
Arirulopecten frttffilis (Hall), S. A. Milluk. Cat. Am. Pal. Foss., p. 184. 1877.
Lunulicardium fragile. Hall. Pi-elim. Notire Lamellibraiichiata, 2, p. 97. 1870.

" " " PaLN. Y., vol. V, pt. 1. Plates and Explanations: PL 71, figs. 1-14. 1883.

Shell small, short, obovate, and more or less variable in form ; abruptly atten-
uate above ; length a little greater than the height ; basal and anterior mar-
gins regularly rounded. Po.sterior side obliquely truncate and margined by
a thin expansion of the shell.

Valves, in their natural condition, moderately convex in the lower part,
and a little gibbous in the umbonal region, but u.sually much compressed
where occurring in the soft shales.

Beaks attenuate, erect.

Surface marked by fine concentric striae, and in well-preserved specimens
by extremely fine radiating striae, which are sometimes more strongly
marked on the posterior portion of the shell.

Three specimens measure respectively 8, 10 and 12 mm. in length, and 8,
9 and 11 mm. in height.

The shells are small and fragile, and usually occur in great numbers in cer-
tain layers of the Marcellus shale and Genesee slate. These fossils are usually
deprived of the thin expansion bordering the hiatus on the posterior side, the
presence of which is shown in figs. 4, 8, 13 and 14 of plate Ixxi.

Formations and localities. Common to the Marcellus shale, Hamilton group,
Genesee slate and Portage group ; also found sparingly in the Chemung group,
N. Y. It has likewise been noticed in the Genesee slate of Ohio and Indiana.

LAMELLIBRANCHIATA. 435

LUNULICARDIUM MaRCELLENSE.

PLATE LXXI, FIGS. 15, 16.

Oypricardites MarcellensU, Vanuxbm. Geol. Surv. N. Y., Rep. Third Dist., p. 147, t. 35, fig. 4. 1842.
Lunitlicardium Marcelltnse, " Hall. Prelim. Notice Lamellibranchiata, 2, p. 97. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 71

figs. 15, 16. 1883.

Shell of medium size, somewhat obovate, truncate behind; length a little
greater than the height. Anterior and basal margins regularly curved. Pos-
terior slope obliquely truncate.

Valves moderately convex below, becoming gibbous in the upper portion.

Beaks anterior to the middle of the length, erect.

Test of moderate thickness. Surface marked by fine, closely arranged
concentric striae. In exfoliated specimens there are indications of radii
which are often more distinctly marked along the margin of the valve.

Three specimens measure respectively 30, 35 and 36 mm. in length, and
32, 33 and 33 mm. in height.

This form differs somewhat from the figure given by Mr. Vanuxem, and a
specimen corresponding, in form, to his figure, shows a few distinct plications
upon the upper anterior margin of the shell. The material in hand is very
unsatisfactory, and better collections may lead to a separation into two distinct
species.

Formation and localities. In the Marcellus shale of Cherry Valley, Sharon
Springs and Schoharie, N. Y.

LUNULICARDIUM RUDE.

PLATE LXXI, FIG. 17.

LunvXicardium rude. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 71, fig. 17. 1883.

Shell of medium size, obovate, obliquely truncate on one side ; length and
height nearly e^iual. Anterior and basal margins regularly curving. Post-
cardinal slope obli(iuely truncate ; margin thickened and deflected.

436 PALEONTOLOGY OF NEW YORK.

Valves n>oderately convex, a little gibbous in the umbonal region.

Beaks anterior to the middle, prominent, inclined forward.

Surface, in the cast, marked by about sixteen or eighteen strong rounded
plications, several of which bifurcate toward the margin. There are a few
irregular varices of growth indicating the aggregation of the concentric striae
and giving a slightly nodose character to the radii.

One specimen has a length of 30 mm. and a height of 29 mm.

This species resembles L. curtum, but the radii are stronger and bifurcate.
Formation and localities. In the Goniatite limestone of the Marcellus shales,
at Cherry Valley and Schoharie, N. Y.

LUNULICARDIUM OBBICULARE, n. Sp.

PLATE LXXI, FIG. 24.

LuniUicardium onuUumf Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 71, fig'. 24. 1883.

Shell of medium size, sub-orbicular; length and height about equal. Pallial
margin regularly curving. Post-cardinal slope obliquely truncate.

Valves moderately convex, scarcely gibbous above.

Be.aks sub-central, slightly inclined forward.

Surface marked by about thirty low rounded plications, which become a
little obscure on the upper anterior margin ; interspaces narrower than the
radii. Also marked by fine undulating concentric striae.

The specimen described has a length and height of about 26 mm.

This species resembles, in its surface characters, L. ornatum, but the shell is
shorter, the posterior truncation also shorter, the radii proportionally larger
and rounded, and the beak is less attenuate.

Formation and locality. In the Marcellus shale, Bloomfield, Ontario county,

N. Y.

LAMELLIBRANCHIATA. 437

LUNULICARDIUM CDRTUM.

PLATE LXXI, FIGS. l»-23.

Lunvlicardium curtum, Hall. Prelim. Notice Lamellibranchiata, 2, p. 97. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates ami Explanations : PI. 71, figs. 18-23. 1883.

Shell below the medium size, ovate, sub-trigonal ; length usually a little less
than the height. Anterior and basal margins regularly curving. Entire
length of the posterior side truncate, with a narrow alation along the margin.

Valves, in well-preserved specimens, regularly convex below, becoming
gibbous in the middle and above.

Beaks anterior to the middle, prominent, incurved and directed forward.

Surface marked by from twenty-five to thirty regular, narrow, rounded or
sub-angular plications, with wider interspaces, and by fine lamellose concen-
tric striae, which arch upward on the plications. Some specimens show a
pustulose character of the surface as indicated in fig. 23 of plate Ixxi.

Three specimens measure respectively 13, 20 and 23 mm. in length, and
14, 18 and 24 mm. in height.

This species differs from L. rude in its greater height, larger number of plica-
tions and more delicate characters. As compared with L. ornatum, it has a pro-
portionally much longer posterior truncation, and fewer and narrower plications.

Formations and localities. In the Marcellus shale at Alden, Erie county, N. Y.,
and in the Hamilton shales on the shores of Cayuga and Seneca lakes, and at
Pratt's falls, TuUy and Hamburg, N. Y.

L0NULICAEDIUM OKNATUM.

PLATE LXXI, FIGS. 25-32.

Pinnopsls onrntux. Hall. Geol. Suiv. N. Y., Rep. Fouith_Dist., p. 244, t. 180, fig. 8. 1843.
iMntdicardimn (yniatmii, Hall. Prelim. Notice Lamellibranchiata, 2, p. 97. 1870.

• ' " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 71, figs. 25-29. 1883.

PiniunmU ai.iiliroiitra, " Oeol. Surv. N. Y., Rep. Fourth Dist., p. 244, t. lOG, fig. 7. 1843.

LimulicanUiim aciUironlruin, Hall. Prelim. Notice Lamellibranchiata, 2, p 97. 1870.

<• " " Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 71, figs. 30-32.

Shell large, broadly obovate, truncate upon the posterior side. Anterior and
basal margins regularly rounded, recurving abruptly at the posterior.
56

438 PALEONTOLOGY OF NEW YORK.

Valves regularly convex below, becoming gibbous in the middle and above.

Beaks anterior to the middle of the length, attenuate, slightly directed
forward.

Surface marked by from forty-five to sixty regular, flattened plications,
with narrower interspaces ; crossed by closely arranged, undulating, lamel-
lose concentric striae.

Three specimens have lengths of 42, 45 and 55 mm. and are of nearly
equal heights respectively.

This species differs entirely from any of the preceding forms, except L. orbi-
culare, from which it is distinguished by a longer truncation upon the posterior
side, and by more numerous and flattened plications.

The typical specimen is of nearly equal length and height, and is marked by
about sixty flattened plications which are not quite properly represented in fig.
28 of plate Ixxi. The prevailing number of rays is from forty to fifty.

The typical specimen of L. acutirostrum has the anterior and posterior mar-
gins abruptly infolded, giving the shell a much narrower aspect than when in
its natural condition. The plications are more slender than in the prevail-
ing forms referred to L. ornatum, and from the infolding of the margin those
of the anterior end are invisible in the figure. The specimen figure 31, subse-
quently referred to the same species, has a greater proportional height than
the prevailing forms of L. ornatum, the plications are also narrower and with
narrower interspaces. A comparison of these forms with larger collections,
showing numerous intermediate phases, makes it impossible to draw lines of
specific distinction, and it is dou})tful if any fixed varietal form exists.

Formations and localities. In the shales of the Portage group at Cashaqua
creek, Livingston county, and in the arenaceous shales of the Chemung group,
at Elmira, N. Y.

LAMELLIBRANCHIATA. 439

LUNULICARDIUM TRANSVERSUM, n. Sp.
PLATE XCIV, FIGS. 24, 25.

Shell above the medium size, sub-cylindrical ; length more than twice the
height; basal margin gently curving. Posterior extremity narrowly
rounded. Cardinal line essentially straight, declining posteriorly. Hiatus
elongate, more than half the length of the shell ; margin defined, but with no
exterior expansion preserved. Anterior end short, narrowly rounded.

Valves very convex in the middle and above ; the convexity declining
gradually toward the posterior end and abruptly toward the base and ante-
rior.

Beaks sub-anterior, small, acute and directed forward. Umbonal slope
convex, not strongly defined, extending to the posterior extremity above the
middle of its height.

Surface marked by about forty narrow rays, which are flattened or rounded
on the middle of the shell, and sub-angular on the anterior and posterior ends.
Entire surface also marked by closely arranged, lamellose concentric striae,
which are often aggregated and at intervals produce sub-imbricating lamellae.

The specimen described has a length of 45 mm. and a height of 20 mm.

This species is distinguished by its elongate and sub-cylindrical form. The
specimen described is somewhat vertically compressed so that the height given
is less than that of the shell in its natural condition.

Formation and locality. In the Chemung group, at Elmira, N. Y.

440 PALEONTOLOGY OF NEW YORK.

PARACYCLAS, Hall. 1843.

[ Type P. elliptica. ]

Paracyclas elliptica.

PLATE LXXII, FIGS. 2S-38 ; AJID PLATE XCV, FIG. 18.

Paraeyclas elliptica. Hall. Geol. Surv. N. Y., Rep. Fourth Dist., p. 171, t 07, %. 2. 1843.

Pal N. Y., vol. V, pt. 1 Plates and Kxplamitions : PI. 72, fig-s. 23-30. 1883.
Lueina {Panuyclax) elliptica, var. Occident aim. Hall and Wiiitkikld. Twenty-fourth Ann. Rep. N. Y.

State MuB. Nat. Hist., p. 189. 1872.

Shell large, sub-circular or broadly sub-elliptical (subject to great variation in
form from compression); length and height about equal. Pallial margin
regularly curving from the extremities of the hinge. Cardinal line short,
more than one-third the length of the shell, slightly arcuate.

Valves regularly convex, somewhat regularly gibbous in the middle.

Beaks a little anterior to the middle, small, appressed and closely incurved,
rising but little above the hinge-line. Umbonal slope defined above by a
depression extending from the beaks to about the middle of the posterior
extremity, distinctly limiting the post-cardinal slope of the valves.

Test thin. Surface marked by fine concentric striae, which are aggregated
into fascicles at irregular distances.

Ligamental groove narrow and elongate. Posterior muscular impression
just within the post-cardinal margin and below the ligamental groove. Pal-
lial line parallel with the basal margin, marked in the cast by a row of elon-
gate nodes, which are the terminations of low ridges from above. Interpal-
lial area pustulose on the cast.

Five specimens measure respectively 30, 32, 40, 44 and 48 mm. in length,
and 29, 33, 37, 40 and 44 mm. in height.

This species has been generally identified with Lucina proavia, Goldfuss
(Petref. Germ., pi. 146, fig. 6, p. 226), but the hinge of that species is much
more declining, and the anterior end is more elevated and sub-auriculate, as
shown in his figures, which are not features in the American form.

LAMELLIBRANCHIATA. 441

The suggestion of the variety ocddentalis came from specimens occurring in
western localities, preserving the shell with all its exterior markings, in which
condition it has not been found in the Corniferous limestones of New York nor
in Ohio, so far as observed. A comparison of a large number of specimens, in
all conditions of preservation, indicates no differences of character which are of
varietal importance.

Formations and localities. In the Corniferous limestone of Western New York,
Canada West, Michigan and Ohio ; also in the limestone of the age of the
Hamilton group at the falls of the Ohio, and Clarke county, Ind.

Paeacyclas lirata.

PLATE LXXn, FIGS. 2-19 ; AND PLATE XCV, FIG. 19.

Posidonia lirata, Conkad. Geol. Surv. N. Y., Ann. Rep., p. 116, pi. [no numbei'], fig'. 12. 1838.

Luciva {Paracyclas) lirata (Conbad), Hall and Whitfield. Twenty-fourth Ann. Rep. N. Y. State Mus.

Nat. Hist., p. 200. 1872.
In part Pararyclas lirata (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 72,

figs. 1-19. 1883.

Shell of medium size, sub-circular or broadly elliptical ; length a little greater
than the height ; margins regularly rounded. Cardinal line short, less than
half the length of the shell.

Valves moderately convex below, becoming gibbous on the middle and
above.

Beaks anterior to the centre, small, appressed, rising but little above the
hinge-line. Post-cardinal slope not defined.

Surface marked by fine concentric striae, and by strong sub-angular con-
centric ridges, which are more or less sharply defined, depending upon the
condition of the specimen and the nature of the matrix in which the fossil is
imbedded.

Ligamental grooves distinctly marked and only moderately divergent from
the cardinal margin.

Four specimens measure respectively 15, 19, 25 and 28 mm. in length, and
13, 18, 22 and 25.5 in height.

442 PALEONTOLOGY OF NEW YORK.

In form, this shell is very like the preceding, but uniformly smaller in size
and marked by more or less distinct, angular concentric ridges. The variation
of form, and surface characters, is illustrated in the figures cited on plate Ixxii.

It also resembles Ludna lineata, Goldfuss (Pet. Germ., p. 226, pl. 146, fig. 8),
from the Devonian of the Eifel, and may not be specifically distinct.

Formations and localities. Very abundant in the shales of the Hamilton group,
in the ejistern and central parts of New York, and in the cherty layers above
the Hydraulic beds at the falls of the Ohio, and in Clarke county, Ind.

Paracyclas Ohioensis.

r

PLATE LXXU, FIG. 1 ; and PLATE XCV, FIG. M.

Lucina {Paracyclas) Ohioensis, Mbbk. Pi-oc. Acad. Nat. Sci., Phila., p. 6. 1871.

" " " " Pal. Ohio, vol. ii, p. 199, pl. 18, figs, la, b. 1873.

In pai"t Parcurydas lirata (Cokkad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: Pl. 72,

figs. 1-19.

This species is a smaller and more delicate form than P. lirata, and with
much finer concentric striae ; the anterior end is more produced and flattened
than in either of the preceding species, and the posterior depression, caused by
the ligamental groove, is more oblique and more decidedly marked on the exte-
rior of the shell.

The posterior extension, as shown by Mr. Meek, is exaggerated in the origi-
nal figures, giving the aspect of an appendage or extension on the posterior
side, while it is only that part of the post-cardinal slope above the ligamental
groove. Fig. 7b {loc. cit.) well represents the form of the species. A compar-
ison of several specimens of this species, with a large collection of P. lirata,
shows it to be a very distinct form.

Formation and localities. The original specimens were derived from Dublin,
Ohio. The specimens which have come under our observation are from cherty
beds above the Corniferous limestone at the falls of the Ohio and in Clarke
county, Ind.

LAMELLIBRANCHIATA. 443

Paracyclas tenuis.

PLATE LXXII, FIGS. 20-2-2 ; and PLATE XCV, FIG. 26.
Paracyclas tenuis. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations ; PI. 72, fig's. 20-23. 1883.

Shell small, sub-circular ; length and height about equal ; margins regularly
curving. Cardinal line short.

Valves moderately convex.

Beaks a little anterior to the middle, small, closely appressed, scarcely
rising above the hinge-line. Post-cardinal slope curved and rapidly declin-
ing backward, limited by the ligamental groove, which is very distinctly
marked.

Test extremely thin. Surface marked by very fine concentric striae, which
are sometimes aggregated into fascicles toward the pallial margin.

Four specimens' measure respectively 7, 8, 9 and 10 mm. in length, and
7.5, 7, 8, 5 and 9 mm. in height.

This species is distinguished by its small size, and very finely striated sur-
face, without distinct undulations.

Formation and localities. In the shales of the Hamilton group on the shores
of Skaneateles, Cayuga and Seneca lakes, N. Y.

Paracyclas Chemungensis, n. sp.

PLATE XCV, FIG. 23.

Shell large, sub-orbicular, erect; length and height nearly equal; margins
regularly rounded. Cardinal line short.

Valves depressed-convex below and convex above.

Beaks sub-central, rather prominent. Umbonal depression very oblique
to the cardinal line.

Surface marked by comparatively even, thread-like striae, which are some-
what fasciculate on the lower and posterior portions of the shell.

One specimen has a length of 30 mm. and a height of 29 mm.

444 PALAEONTOLOGY OF NEW YORK.

This species has the size and form of P. elliptica, but differs in its more prom-
inent beaks and more regular concentric strite.

Formation and localities. In the Chemung group at Mansfield, Pa., and doubt-
fully at Philipsburgh, N. Y.

Paracyclas ignota.

PLATE LXJOI, FIG. 34.
Paracyclas ignota. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 72, fig. 34. 1883.

Shell large, obliquely sub-circular, or very broadly sub-ovate ; margins regu-
larly curved, slightly produced in front.

Valves of moderate convexity.

Beaks sub-central, somewhat prominent, rising a little above the hinge-
line. Umbonal depression obscure.

Surface, in the cast, marked by fine concentric striae, which have been
somewhat fasciculate.

The specimen described has a length of 41 mm. and a height of 38 mm.

This species diflfers from P. Chemungensis in being a larger form, with less
prominent beaks, and with the shell more extended in the upper part. It also
differs from P. rotunda in its less prominent beaks, less marked umbonal furrow,
and in the upper anterior extension and obliquity of the body of the shell.

Formation and locality. In the Chemung group, Metidville, Pa. ^

Paeacyclas rotunda.

PLATE LXUI, FIGS. 18, 19 ; and PLATE XCV, FIG. 21.

In part Carditnuorplia rciunda. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 63,

figs. 17-20. 1883.

Shell large, sub-orbicular, or very broadly sub-ovate ; length a little greater
than the height. Anterior and basal margins regularly curving. Posterior
end sub-truncate.

Valves regularly convex below, becoming gibbous in the middle and above.

LAMELLIBRANCHIATA. 445

Beaks sub-central, prominent, rising above the hinge-line. Umbonal fur-
row oblique, broad and strongly marked.

Surface marked by fine concentric striae, which are sometimes fasciculate,
as shown on the cast of the interior.

A specimen has a length of 48 mm. and a height of 43 mm.

This species is distinguished by its large size, prominent beaks, and broad
defined umbonal furrow.

Formation and localities. In the sandstones of the Chemung group, at Kirk-
wood, Broome county, and Lindley township, Steuben county, N. Y.

Paracyclas erecta, n. sp.

PLATE XCV, FIG. 22.

Shell of medium size, rhomboid, sub-elliptical ; height one-fifth greater than
the length. Anterior margin regularly curving, from the beaks to the post-
basal extremity, which is slightly produced. Posterior margin vertical.
Cardinal line short.

Valves moderately convex below, becoming somewhat gibbous in the
umbonal region.

Beaks sub-central, small, but little elevated above the hinge. Umbonal
slope obtusely sub-angular, extending to the post-inferior extremity.

Surface marked by fine concentric striae which, toward the anterior and
basal margins, are fasciculate.

The cardinal margin, in the cast, is marked by two slender ligamental
grooves, diverging from behind the beak.

A specimen has a length of 20 mm. and height of 25 mm.

This species is unlike any other in its erect form, vertical posterior margin
and defined umbonal ridge. The umbonal ridge gives the fossil the aspect of
ScHizoDUS, but the shell is more delicate than in the species of that genus, the
hinge is shorter, the beaks small and appressed, and the diverging grooves,
along the cardinal line are similar to Paracyclas.
57

446 PALEONTOLOGY OF NEW YORK.

Formation and localilies. In the upper members of the Chemung group, at
Warren, Pa.

Paracyclas? pauper.

PLATE LXXV, FIGS. 2»-28 ; AND PLATE XCV, FIG. 20.

Cgtlierodon (Schizodus) pauper, Hall. Pal. N. Y., vol. v, i>t. 1. Plates and Explanations!: PI. 75,

figs. 24-26. 1883.

Shell small, sub-orbicular ; height nearly equal to the length. Margin regularly
curving from the distinct lunule to the post-inferior extremity, whence it
abruptly curves to the post-cardinal extremity. Cardinal line short.

Valves moderately convex below, gibbous in the middle and above.

Beaks at about the anterior third, somewhat prominent and arching for-
ward. Umbonal slope rounded, not strongly defined.

Surface marked by fine concentric striae, which are partially preserved in
the cast.

Three specimens measure respectively 15, 20 and 22 mm. in length, and
14, 18 and 20 mm. in height.

The general aspect and form of the shell appear to ally this species with
Paracyclas, but its absolute relations are undetermined.

Formation and locality. In the sandstone of the Chemung group, at Port-
viUe, N. Y.

LAMELLIBRANCHIATA. 447

SCHIZODUS, King. 1844.

SCHIZODUS ? FISSA.

PLATE LXXII, FIGS. 35-41.

Paracyclasf fissa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 72, fijfs. 35, 36. 1883.
elemta, " Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 72, figs. 37-41. 1883.

Shell of medium size or larger, obliquely sub-ovate, or sub-trigonal ; length
greater than the height ; basal margin regularly rounded. Posterior extrem-
ity narrowly rounded below, and gently curving toward the beak. Cardinal
line short, about half the length of the shell. Anterior end short, regularly
rounded.

Valves regularly convex below, gibbous in the middle and above.

Beaks in advance of the anterior third, large, acute, prominent and but
little incurved in the cast. Umbonal slope arcuate, marked by a slight
depression.

Surface of the cast marked by fine concentric striae.

This species carries a distinct lunule and a deeply marked escutcheon.
The anterior nmscular impression is very strongly marked, situated close to
the anterior margin, immediately below the lunule. Posterior scar large,
shallow, situated on the post-cardinal slope, near the extremity. The cast is
distinctly marked by a groove, extending from the beaks obliquely backward
more than half way to the base in well-preserved specimens, and is much
more strongly marked on the beaks and upper part of the valve.

Three specimens measure respectively 31, 34 and 40 mm. in length, and
28, 29 and 34.5 mm. in height.

This species is referred with doubt to the genus Schizodus, since we have no
means of ascertaining the characters of the hinge. As compared with the species
of that genus, in the succeeding formations, it differs in the arcuation of the
cardinal line, and the narrow and rounded post-cardinal slope. A further
examination of the specimens shows that those heretofore recognized as two
species should be united under a single name.

Formation and locality. In the Schoharie grit, at Schoharie, N. Y.

448 PALEONTOLOGY OF NEW YORK.

SCHIZODUS TUMIDUS.

PLATE LXXV, FIGS. 1, S.

Sdtitodus tumidus. Hall. Prelim. Notice I>ameIlibranchialA, 2, p. 94. 1870.

CfgUterodm " " Twenty-third Rep. N. Y. State Mus. Nat. Hist. Expl. PI. 14, tig. 19. 1872

(title page, in error, 1873).
C!ytlten)doH (Schizodux) iumidits, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 75,

figs. 1, 2. 1883.

Shell of medium size, rhomboid-ovate ; length about one-fourth greater than-
the height. Basal margin regularly rounded anteriorly, produced a little in
the middle and sub-truncate behind. Posterior margin obliquely truncate.
Cardinal line short, straight. Anterior end short and regularly rounded.

Valves convex below, gibbous in the middle and above.

Beaks at about the anterior third or fourth, prominent, rising considerably
above the hinge-line. Umbonal slope sub-angular, bending downward in
the middle and continuing to the posterior extremity, producing a nasute
extension.

Surface characters unknown.

Muscular impression strongly marked. Pallial line distinct.

The specimen described is a cast of the interior, having a length of 40
mm. and a height of 30 mm.

This species resembles S. appressa in general form, but the umbonal angle is
less sharply defined in the cast, the beaks are larger, and the posterior muscular
impression is much stronger and nearer to the beaks.

Formation and locality. In the limestone of the Upper Helderberg group, near
Columbus, Ohio.

LAMELLIBRANCHIATA. 449

SCHIZODUS APPRESSUS.

PLATE LXXV, KIGS. 3-9.

Nuculites appressa, Conrad. Jour. Acad. Nat. Sci. Phila., vol. viii, p. 248, pi. 15, tig. 4. 1842r
SchUodus appressus (Conrad), Hall. Prelim. Notice Lameliibranchiata, 2, p. 95. 1870.
Cytherodcm " " " Twenty-tliird Rep. N. Y. State Mus. Nat. Hist. Expl. pi. 14,

fig-. 20. 1872.
" (Schizodus) appressus (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

Pi. 75, figs. 3-9. 1883.
Schizodus Cayuga, Hall. Prelim. Notice Lameliibranchiata, 2, i>. 95. 1870.

Shell of medium or large size, sub-rhomboicl-ovate ; length one-sixth to one-
■ fourth greater than the height ; basal margin regularly rounded, with a
slight constriction or truncation of the margin near the posterior end. Pos-
terior extremity obliquely truncate. Cardinal line slightly arcuate, less than
half the length of the shell. Anterior end short, broadly rounded into the
basal margin.

Valves moderately convex below, becoming somewhat gibbous in the mid-
dle and above.

Beaks at about the anterior third or fourth, moderately prominent, rising
but little above the hinge. Umbonal slope sub-angular, distinct, extending
to the post-inferior extremity which is often somewhat nasute.

Surface marked by fine concentric strias, which are aggregated into fasci-
cles on the lower and posterior parts of the shell.

Muscular impressions and pallial line distinctly marked. Valves marked,
on the interior, by two narrow furrows along the umbonal slope, showing as
two ridges in the cast. Left valve with a single strong, divided cardinal
tooth, and a strong posterior lateral tooth which is grooved along its summit.

Five specimens measure respectively 22, 28, 32, 36 and 42 mm. in length,
and 18, 23, 25, 26 and 29 mm. in height.

This species is very similar in form to S. tumidus, but is less gibbous, the
beaks are less prominent and the posterior muscular impression is farther
behind the beak. S. tumidus is founded upon a single cast of the interior, and,
therefore a full comparison cannot be made.

450 PALMONTOLOGY OF NEW YORK.

The n.aine S. Cai/uga was given to a specimen sloping more abruptly along
the cardinal line, with the basal margin a little emarginate just anterior to the
post-inferior angle, which is distinctly nasute. These features are only a
greater development of characters belonging to typical forms of S. appressns.

Formation and localities. In the Hamilton group, on the shores of Seneca
and Cayuga lakes ; at Pratt's falls, Onondaga county ; and Summit, Schoharie
county, N. Y.

SCHIZODUS ELLIPTICU8.

I'LATE LXXV, FIGS. 13-15.

Schizodus elliplieics. Hall. Prelim. Notice Lamellibranchiata, 2, p. 96. 1870.

Cytherodon (Schizudtis) elliptietis, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 75,

figs. IS-LI. 1883.

Shell small, sub-elliptical ; length one-fourth greater than the height ; basal
margin regularly curving. Posterior extremity obliquely or sometimes
almost vertically truncate. Cardinal line short. Anterior end broadly
rounded.

Valves depressed-convex below, convex in the middle and above.

Beaks behind the anterior third, small, appressed, rising very little above
the hinge-line. Umbonal slope obtusely angular, extending to the post-
inferior extremity.

Surface marked by fine, somewhat regular concentric striae. Interior
unknown.

Two specimens measure I'espectively 15 and 24 mm. in length, and 12 and
16.5 mm. in height.

This species diifers from S. appressvs in its more elliptical form, longer ante-
rior end, and the post-inferior extremity is less produced.

Formation and locality. In the soft shales of the Hamilton group, on the shore
of Canandaigua lake, N. Y.

LAMELLIBRANCHIATA. 451

SCHIZODUS CONTRACTUS, n. sp.

PLATE LXXV, riGS. 27, 28.

In part Cytherodon (Schizodus) cuneus, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 75,

figs. 27-.30. 1883.

Shell small, ovate-cuneate ; length one-third greater than the height ; basal
margin regularly curving. Posterior extremity pointed, nasute below,
obliquely truncate above. Cardinal line more than half the length of the
shell. Anterior end short, regularly rounded.

Valves regularly convex below, gibbous in the middle and above.

Beaks at about the anterior third, prominent, incurved, flattened. Umbo-
nal slope distinctly angular, extending to the post-inferior extremity. Post-
cardinal slope concave, marked by a narrow depression near the cardinal
line.

Surface marked by fine, elevated, sharp, filiform concentric striae, which
become fasciculate toward the margin ; also sometimes marked by very fine
radiating striae.

Anterior muscular impression strongly limited posteriorly.

Two specimens measure respectively 14 and 15 mm. in length, and 9 and
10 mm. in height.

This species resembles S. cuneus, of the Waverly sandstone, but is propor-
tionally longer, the umbonal angle is sharper, the cardinal slope is broader and
the basal margin is more broadly rounded.

This shell hfis the general aspect of a Nucula, but the contraction of the pos-
terior end and the umbonal angle, indicate its relations with Schizodus.

Formation and locality. In the Hamilton group, near the top of the formation,
on the shore of Cayuga lake, N. Y.

452 PALMONTOLOGY OF NEW YORK.

SCHIZOUUS OREGARIUS.

PLATE LXXV. FIGS. lG-18 ; AND I'LATK XCV, FIG. 27.

SehiziHlit.t gregariux. Hall. Pi-elira. Notice Lamellibranchiata, 2, p. 97. 1870.

CythiTodon (Sdiizoiiux) gi-t-ffarivx. Hall. Piil. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 75,

tigs. 16-18. 1883.

Shell small, sub-rhomboid-ovate, sometimes sub-cuneate from compression ;
length from one-fourth to one-third greater than the height ; basal margin
regularly and broadly curving. Posterior extremity somewhat pointed
below and obliquely sub-truncate above. Cardinal line short, less than half
the length of the shell. Anterior end short, broadly rounded.

Valves moderately convex below, becoming somewhat gibbous in the mid-
dle and above.

Beaks at about the anterior third, small, rising little above the hinge-line.
Umbonal slope obtusely sub-angular, continuing to the post-inferior extremity.

Surface marked by fine concentric striae.

Two specimens measure respectively 12 and 15 mm. in length, and 9 and
12 mm. in height.

This species is similar in form to 3'oung individuals of S. appressus, but is
proportionally longer. It is also smaller and proportionally longer than speci-
mens of iS. rhombeus.

Formation and locality. Abundant in some chocolate-colored, sandy shales of
the Chemung group, on the banks of the Tioga river, near Covington, Pa.

SCHIZODUS RHOMBEUS.

PLATE LXXV, FIGS. 19-23.

C'ypricardiaf rhombea. Hall. Geol. 8urv. N. Y., Rep. Foui-th Dist., p. 291, t. 139, figs. 2, 3. 1843.
{•Icfiizodux rhmnlieim, Hall. Prelim. Notice I^amellil)ran<;hiata, 2, j). 97. 1870.

CijlJurndini (.S'cAizorfw) rhiinlM'Un, Hall. Pal N. Y., vol. v, jit. 1. Plates and Explanations: PI. 75,

figs. 19-23. 1883.

Shell below the medium size, sub-rhomboidal ; length a little greater than the
height ; margins regularly rounded from the anterior end to the post-inferior
extremity. Posterior extremity truncate. Cardinal line short.

LAMELLIBRANCHIATA. 453

Valves moderately convex below, and gibbous in the middle and above.

Beaks in advance of the anterior third, prominent, rising considerably
above the hinge-line, and incurved. Umbonal slope distinctly angular,
extending to the post-inferior extremity.

Surface marked by fine concentric striae, which are scarcely preserved in
the cast.

Two specimens measure respectively 18 and 20 mm. in length, and 16 and
18 mm. in height.

This species is distinguished by its rhomboid, erect form, its nearly equal
length and height, and the divergence of the umbonal slope from the cardinal
line, in which respect it resembles S. quadrangularis, but is a nmch smaller
form.

Figure 20 is of one of the original specimens from the sandstone of the age
of the Panama conglomerate, while the others are from lower beds. Larger
collections may show the necessity of separating these two forms, which are
from very distinct horizons.

Formation and localities. In the sandstone of the Panama conglomerate,
Chautauqua county, and from the middle portion of the Chemung group, near
Hobbieville, Alleghany county, N. Y.

ScHizoDcs Chemungensis.

PLATE LXXV, FIGS. 37-40, 45, 41 ?.

Nuculitis ChemungeniMS, Conrad. Jcjui-. Acad. Nat. Sci., Phila., vol. viii, p. 247, pi. 13, tig. 13. 1842.
SehUodun Chemungeiutis (Conrad), Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 96. 1870.
Cytherodnn (Sihizodus) ChemungeiiKis (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. 75, figs. 37-40. 1883.

Shell large, rhomboid-ovate; length one-fourth greater than the height.
Anterior margin broadly rounded, curving into the basal margin, which is
sometimes nearly straight posteriorly. Post-inferior extremity angular.
Posterior margin obliquely truncate. Cardinal line straight, less than half
the length of the shell.

Valves depressed-convex below, becoming gibbous in the middle and
58

454 PALEONTOLOGY OF NEW YORK.

above. In its usual condition of preservation the shell is very much
depressed.

. Boaks at about the anterior third, prominent. Umbonal slope sub-angular,
defined above, less prominent below.

Surface marked by fine concentric striae of growth, which are partially
preserved in the cast.

Three specimens measure respectively 33, 35 and 43 mm. in length, and
25, 29 and 30 mm. in height.

This species resembles S. appressus in form and proportions and is probably
only a variety of that species which lived under different conditions.

Formation and localities. In the Chemung group, at Chemung Narrows ; near
Ithaca and Cortland, and in Lindley township, Steuben county, N. Y. ; also in
Tioga and Susquehanna counties, Pa.

ScHizoDus Chemungensis, var. quadrangularis.

PLATK LXXV, HGS. 81-34, 36.

In part Scltizodux qitadrangularU, Hall. Prelim. Notice Lamellibranchiata, 2, p. 96. 1870.

" Cytherodim {Sclmodits) qtuidrangulari.1. Hall. Pal. N. Y., vol. v, i)t. 1. Plates and Explanations :

PI. 75, figs. 31-36. 1883.

Shell large, rhomboidal ; length somewhat greater than the height ; basal
margin broadly rounded. Posterior extremity pointed below and truncate
above. Cardinal line about half the length of the shell. Anterior end large,
broadly rounded.

Valves depressed-convex below, becoming convex or gibbous in the mid-
dle and upper portions.

Beaks between the middle and anterior third, prominent, rising above the
hinge-line. Umbonal slope distinctly angular, defined, extending to the
post-inferior extremity.

Surface marked by fine concentric striae, which are partially preserved in
the casts. The umbonal slope, in the cast, is marked by a sharp angularity
extending from the beak half way to the post-inferior extremity. The car-
dinal slope is marked by a furrow along the middle for half its length.

The pallial line extends at some distance from the margin, terminating in

LAMELLIBRANCHIATA. 455

an elongate posterior muscular impression. Anterior muscular impression
strongly marked.

Three specimens measure respectively 30, 34 and 38.5 mm. in length, and
26, 28 and 33 mm. in height.

This form appears to be only a variety of S. Chemungensis, with a more erect,
distinctly quadrangular outline, and having a wider post-cardinal slope.

Formation and localities. In the Chemung group, on Cayuta creek and at
Factory ville in Tioga county ; on the banks of Chemung creek and at Ithaca,

N. Y.

SCHIZODUS OBLATUS.

PLATE LXXV, FIGS. 43, 44.

Schizodus oblatus, Hall. Prelim. Notice Lamellibranchiata, 2, p. 97 1870.

In part Oytherodcm (SchUodiis) oblatits. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 75,

fig-8. 41-45. 1883.

Shell of medium size or larger, broadly sub-elliptical; length one-fourth
greater than the height; basal margin regularly curving. Post-inferior
extremity obtusely angular and the margin above sub-truncate. Cardinal
line less than half the length of the shell. Anterior end broadly rounded. .

Valves convex in the lower portion, becoming gibbous or ventricose in the
middle and above, depressed-convex along the middle of the lower portion of
the valve.

Beaks a little anterior to the middle, prominent, broad and rounded.
Umbonal slope obtusely sub-angular, extending to the post-inferior extrem-

ity.

Surface marked by fine concentric striae, which are but ftiintly preserved
in the cast.

Muscular impressions strongly marked. The posterior scar, on the cardi-
nal slope, is at about the middle of the height of the valve.

Two specimens measure respectively 30 and 32 mm. in length, and 22 and
24.5 mm. in height.

This form differs from any other of the genus, here noticed, in the prominent

456 PALEONTOLOGY OF NEW YORK.

sub-central beaks, the ventricose valves, and in the undefined sub-angular umbo-
nal slope.

Formation and locality. In a sandstone of the Chemung group, at Cold
Spring, Napoli, Cattaraugus county, N. Y.

SCHIZODUS DEGENER, n. Sp.
PLATE LXIII, FIG. 17.

In pai-t Cardioinorpha rotmula. Hall. Pal. N. Y., vol. v, pt. 1. Plates ami Explanations: PI. 63,

fijfs. 17-20. 1883.

Shell large, very broadly elliptical ; length one-sixth greater than the height.
Basal margin broadly curving. Post-inferior extremity scarcely extended
beyond the general outline ; margin sub-truncate above. Cardinal line less
than half the length of the shell. Anterior end large, contracted below the
beak and broadly rounded below.

Valves moderately convex in the lower and marginal portions, becoming
gibbous in the middle.

Beaks a little anterior to the middle, large and prominent, rising conspicu-
ously above the hinge-line. Umbonal slope obtusely angular above, merg-
ing into the general convexity of the shell below the middle.

Surface marked by fine concentric striae, which are obscurely preserved
in the cast.

A specimen has a length of 40 mm. and a height of 33.5 mm.

This species is distinguished from all others except S. oblatus by the sub-cen-
tral po-sition of the beaks, and also by the absence of an umbonal ridge at the
post-inferior extremity.

Formation and localities. The specimen figured is recorded as coming from
the Chemung group ; locality unknown. A single imperfect specimen having
similar proportions is from the Chemung group at Lawrenceville, Tioga
county. Pa.

LAMELLIBRANCHIATA. 457

SCHIZODUS PATULUS, n. Sp.

I'LATE LXIII, FIG. 20.

In part Cardiomorpha rotunda. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 63, figs. 17-20.

1883.

Shell very large, broadly ovate ; length one-fourth greater than the height.
Basal margin broadly curving. Post-inferior extremity narrowly rounded ;
margin above obliquely sub-truncate. Cardinal line short. Anterior end
large, contracted below the beak and broadly rounded below.

Valves moderately convex below, becoming gibbous in the middle.

Beaks a little anterior to the centre, prominent and rising above the hinge-
line. Umbonal slope not defined, its continuation indicated by an extension
of the shell at the post-inferior angle.

Surface marked by fine concentric strise which are obscurely preserved on
the cast of the interior.

The specimen described has a length of 60 mm. and a height of 45 mm.

This species is distinguished by the sub-central position of the beaks, unde-
fined umbonal ridge and flattened posterior end of the shell.

Formation and locality. In the Chemung group near Tioga, Tioga county. Pa.

SCHIZODUS EMINENS, n. sp.
PLATE XCV, FIG. 28.

Shell very large, obovate, sub-trigonal ; length a little less than the height ;
basal margin regularly curved. Post-inferior extremity sub-angular. Pos-
terior margin nearly vertically truncate. Cardinal line very short. Ante-
rior end short, broadly curving into the basal margin without limitation.

Valves moderately convex below, becoming gibbous in the middle and
above.

Beaks sub-central, prominent, rising a little above the hinge-line. Umbo-

458 PALEONTOLOGY OF NEW YORK.

nal slope distinctly angular, slightly arching, and extending to the post-infe-
rior extremity. Post-cardinal slope narrow, gently concave.

Surface marked by fine concentric striae, which are preserved in the cast,
and are fasciculate on some portions of the shell.

The specimen described has a length of 53 mm. and a height of 55 mm.

This species is distinguished by its large size, great elevation, broad rounded
base, narrow cardinal slope, and sub-erect umbonal ridge. In these characters
it differs very distinctly from any of the other species known in the rocks of
New York.

Fortnation and locality. In the Chemung group, one mile west of Guilford,
Chenango county, N. Y.

SCHIZODUS CUNEUS.

PLATE LXXV, FIGS. 29, 30 ?.

In part Cytherodon {Schizodtcs) cuiieus, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: P). 75,

figs. 27-30. 1883.

Shell small, ovate-cuneate ; length about one-fourth greater than the height ;
basal margin broadly curved. Post-inferior extremity angular. Posterior
margin very obliquely truncate. Cardinal line equal to about half the length
of the shell. Anterior end short, contracted just below the beak and regu-
larly rounded below.

Valves gently convex below, becoming gibbous in the middle.

Beaks at about the anterior fourth, moderately prominent. Umbonal
slope angular, defined, extending to the post-inferior extremity.

Surface marked by fine fasciculate concentric striae, the remains of which
are still preserved in the cast.

The anterior muscular impression is comparatively large and strongly
limited on the posterior side. The impression of the strong cardinal tooth
is preserved beneath the beak.

Two specimens measure respectively 20 and 22 mm. in length, and 15 and
15 mm. in height.

LAMELLIBRANCHIATA. 459

This species resembles S. contractus of the Hamilton group, but is a larger
shell, and differs in the more direct umbonal ridge, less gibbous valves, and in
the absence of a sinuosity in the posterior margin.

Formation and locality. In the Waverly sandstone, at Granville, Licking
.county, 0.

SCHIZODUS iEQUALIS, n. Sp.

PLATE LXXV, FIG. 35 ; and PLATE XCV, FIG. 29.

In part Cytherodon (Sehizodus) qvadrangularls. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations :

PI. 75, figs. 31-36 (35 in error). 1883.

Shell large, obovate ; body of the shell sub-triangular ; length a little greater
than the height ; basal margin regularly curved. Post-inferior extremity
very slightly produced. Posterior margin somewhat vertically truncate.
Cardinal line short. Anterior end large, contracted beneath the beak and
broadly rounded below.

Valves gently convex below, becoming moderately gibbous in the middle.

Beaks sub-central, elevated, rising considerably above the hinge-line.
Umbonal slope obtusely sub-angular, extending to the post-inferior extrem-
ity. Post-cardinal slope rather wide, gently concave.

Surface marked by fine concentric strias, which are partially preserved on
the nearly smooth casts.

A large specimen has a length of 52 mm. and a height of 45 mm.

This species bears considerable resemblance to S. Chemungensis, var. quadran-
gularis, but the base is more broadly rounded, and the anterior portion is more
expanded below, giving the shell a more equilateral appearance.

Formation and locality. In the Waverly sandstone, at Granville, Licking
county, 0.

460 PALEONTOLOGY OF NEW YORK.

P ROTH Y III S, Meek. 1869.
Prothyris planulata.

PLATE LXXVl, FlU. 1 ; and PLATE XCIV, FIG. 8.
Prothyris plawdata. Hall. Pal. N. Y., vol. v, l>t. 1. Plates and Explanations: PI. 7ti, fig. 1. 1883.

Shell small, Ugulate ; length more than twice the height. Basal margin nearly
straight, curving anteriorly and truncate behind. Posterior extremity verti-
cally truncate. Cardinal line long, straight, essentially parallel to the basal
margin. Anterior end auriculate, limited from the body of the valve by a
constriction and deep sinus in the margin.

Valves depressed-convex below, more convex above the middle of the shell.

. Beaks sub-anterior, low and inconspicuous. Umbonal slope angular,

extending to the upper posterior extremity, below which is a shallow groove

extending from the umbo to the post-inferior extremity. Post-cardinal

slope narrow and concave.

Surface marked by strong concentric stria3, which are aggregated into ftis-
cicles along the basal margin.

A specimen of ordinary size has a length of 17 mm. and a height of 7 mm.

This species differs from P. elegans, Meek, in being proportionally higher,
with convex basal margin, posterior extremity decidedly truncate, the umbonal
slope distinctly angular with a shallow furrow below, extending from the beak
to the post-inferior extremity, and in having more irregular concentric striae.

Formation and localities. In the shales of the Hamilton group at the outlet
of Crooked lake and near Norwich, Chenango county, N. Y.

Prothyris lanceolata.

PLATE LXJCVI, FIGS. i-8.
Prothyrit lanceolata, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 7(), figs. 2-8. 1883.

Shell of medium size, elongate-lanceolate ; length three times the height.
Basal margin very gently curving, often nearly straight on the anterior half.
Posterior extremity pointed, very obliquely truncate above. Cardinal line
about two-thirds the length of the shell. Anterior end truncate, margin

LAMELLIBRANCHIATA. 461

reflexed, with a slight constriction behind it and without any conspicuous
limiting notch.

"Valves moderately convex in the posterior part, gibbous in the middle
and umbonal portions.

Beaks sub-anterior, not prominent, slightly incurved. Umbonal slope
angular above, extending to the posterior extremity, often merging into the
general convexity of the shell below the middle. Post-cardinal slope nar-
row, slightly concave.

Surface marked by fine concentric striae, which are sometimes somewhat
fasciculate, producing gentle undulations of the surface.

Two specimens measure respectively 15 and 20 mm. in length, and 5 and
7 mm. in height.

This species differs from the preceding in its elongate lanceolate form,
obtusely angular umbonal ridge and in the pointed posterior extremity.

Formation and localities. In the shales of the Hamilton group at Fultonham,
Schoharie county ; Sherburne and Norwich, Chenango county ; Pratt's falls,
Onondaga county; and on the shores of Cayuga and Canandaigua lakes, N. Y.

Prothyris alata, n. sp.

PLATE XCIV, FIG. 7.

Shell small ; body of the shell narrowly ovate, acute ; length twice the height ;
basal margin gently curving. Posterior extremity pointed. Cardinal line
more than half the length of the shell. Anterior end truncated by a vertical
groove, beyond which is a narrow parallel fold, which is notched at the base.

Valves regularly convex.

Beaks sub-anterior, low, not defined. Umbonal slope angular, marked
below by two or three radiating striae, which extend from the umbo to the
posterior extremity of the shell. Cardinal slope alate, marked by distinct
radiating striae.

Surface marked by very fine concentric striae, and the cardinal slope by
fine radiating striae.

The specimen described has a length of 8.5 mm. and a height of 4 mm.
59

462 PALEONTOLOGY OF NEW YORK.

This species is distinguished by its alate cardinal slope, which is marked by
distinct radiating stria).

Formation and locality. \n the Chemung group, near Philipsburgh, Alleghany
comity, N. Y.

Prothyris exuta, n. sp.

PLATE XCIV, FIG. 9.

Shell large, elongate-trapezoidal ; length more than twice the height ; basal
margin nearly straight, gently curving toward the posterior extremity. Pos-
terior extremity obliquely truncate. Cardinal line more than half the length
of the shell. Anterior end regularly reunded, with a fold and constriction
just anterior to the umbo, and a slight notch or sinuosity in the margin at
the base of the constriction. '

Valves depressed-convex in the lower portion, becoming gibbous in the
middle and on the umbonal slope.

Pliice of the beaks occupied by an opening which appears to have existed
during the life of the animal. The margin of this aperture is not fractured,
but appears to be entire and to have ]>een slightly retlexed. Umbonal slope
obtusely sub-angular, extending in a slightly arcuate direction to the post-
inferior extremity.

Surhice marked by fine concentric striae, which are scarcely preserved in
the cast.

Two specimens measure respectively 32 and 34 mm. in length, and 13 and
14 mm. in height.

This species somewhat resembles P. lanceolata, but it is a larger shell, the
posterior termination is at the base and not in the middle, as in that species,
and the characters of the anterior end are very different.

The large opening in tlie place of the beaks appears to have existed in the
shell during its life-time, and is a very peculiar feature. It may, perhaps, when
further collections are studied, necessitate its separation from typical Prothyris.

Formation and locality. In the upper part of the Chemung group, at Warren,
Pa.

LAMELLIBRANCHIATA. 4G3

SOLEMYA, Lamarck. 1818.

( Janeia, King. 1850. )

SoLEMYA (Janeia) vetusta.

PLATE Xl.VlI, FIGS. 53-55; aNU PLATE XCIV, FIG. 10.

iSolenuia (Jaiieia) vetusta, Mkkk. Proc. Acad. Nat. Sci., Phila., p. 10. 1871.

Pal. Ohio, vol. 1, p. 206, pi. 18, tig-. 4. 1873.
Yoldiaf volvulus. Hall and Whitfield. Twenty-fourtli Ann. Rep. N. Y. State Mus. Nat. Hist., p. 190.

1872.
" " " Hall. Pal. N. Y., vol. v, i)t. 1. Plates and Explanations :

PI. 47, tigs. 53-.55. 1883.

Shell of medium size, elongate-elliptical ; length more than twice the height;
basal margin very gently curved. Posterior extremity rounded. Cardinal
line nearly straight, or gently arcuate. Anterior end large, narrower than
the posterior, rather abruptly rounded at the extremity, carrying on its upper
margin a distinct fold.

Valves moderately convex below, scarcely gibbous in the upper portion.

Beaks inconspicuous, situated anterior to the middle.

Surface marked by regular, distinct, laiiiellose, undulating, concentric
striae, which are crossed by distant radiating lines, between which the con-
centric striae curve downward.

Three specimens measure respectively 26, 27 and 35 in length, and 11, 12
and 15 mm. in height.

A careful examination has shown that this species is closely allied to
SoLEMYA, and we have not a sufficient knowledge of the interior structure to
separate it from that genus.

Formations and localities. In the cherty layers above the Hydraulic beds, at
the falls of the Ohio, in strata referred to the Hamilton group. It is cited by
Mr. Meek as occurring in the Corniferous limestone, at Dublin, 0.

464 PALEONTOLOGY OF NEW YORK.

TELLINOPSIS, Hall. 1870.
Tellinopsis scbemarginata.*

PLATK LXXVI, FIGS. 21-31.

NiicvJites .tiiheittaiylnaia, Cosrad. Jour. Acatl. Nat. Sci., Phila., vol. viii, p. 240, pi. 15, fig-. .'5. 1842.
Teilhtopsix mibvmargiiuUa (Conk.id), Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 80. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 7G,

figs. 21-31. 1883.

Shell large, elliptical, sub-quadrate ; length more than once and a half the
height. Biisal margin straight or gently curving. Posterior extremity sub-
emarginate in the middle and rounded above and below, sometimes truncate
or rounded with no emargination. Cardinal line gently arcuate. Anterior
end regularly rounded, large, usually equaling or greater than the posterior
half of the shell.

Valves moderately convex below and toward the extremities, becoming
gibbous in the middle and umbonal region.

Beaks sub-central, rather prominent, elevated above the hinge-line and
incurved. Umbonal slope rounded, distinct, defined above by a depression
which is sometimes a furrow extending from the beak to the middle of the
posterior margin or below, producing a slight emargination. The post-cardi-
nal slope above the depression is convex.

Surfiice marked by fine concentric striae, which are sometimes fascicled,
producing undulations of the surface, and also by radiating striae which are
more or less distinct. From the anterior side of the umbo there extends a
flattened space, limited on each side by a low ridge, extending to the antero-
basal margin, producing an undulation in the direction of concentric striae.

Five specimens measure respectively 20, 26, 28, 31 and 49 mm. in length,
and 12, 16, 16, 19 and 28 mm. in height.

This species has apparently no relation with any other form described in this

*A weIl-marke<J Bj«»(;im('n of this sp(>(ncR in tho author's collection beai'S the following label in Mr. Con-
rad's handwriting: " Posidonia lelliTundfXfConRiv. Outline fig., p. 1." The reference is to a plate of outline
figures never published, and the writer has not found the name i-ecoiiled in any publication of Mr. Cokrad.

LAMELLIBRANCHIATA. 465

volume. It is distinguished by the central position of the beaks, the emargi-
nate posterior end and the peculiar character of the surface radii.

Formation and localities. In the shales of the Hamilton group at Fultonham,
Schoharie county, and on the shores of Skaneateles, Otisco, Cayuga, Seneca
and Canandaigua lakes ; at Smyrna, Chenango county, and in other places in
the State of New York.

CIMITARIA, Hall. 1870.

CiMITARIA CORRUGATA.

I'l.ATK LXXVII, FIGS. 1-4.

Cj/prieardites eorrugata. Conrad. Jour. Acaii. Nat. Sd., vol. viii, p. 244, pi. 13, fig. 6. 1843.
Vimilaria cmiiigata (Conrad), Hall. Pi'elim. Notice Lamfllibranchiata, 2, p. 67. 1870.

" Pal. N. Y., vol. V, pt. 1. Platos and Explanations : PI. 77, figs. 1-4.
1883.

Shell large, sub-falciform, extremely elongate, with the cardinal line curving
upward at the extremities ; length three times the height ; basal margin
regularly curving, with a gentle sinuosity near the anterior end. Posterior
extremity vertically or somewhat obliquely truncate. Cardinal line concave,
essentially parallel with the basal margin. Anterior end obliquely truncate
above and rounded below into the basal margin.

Valves depressed-convex in the lower and posterior portions, more convex
and .somewhat gibbous in the umbonal region.

Beaks at about the anterior sixth, prominent and incurved. Umbonal
slope angular, marked by a distinct fold, which extends to the post-inferior
extremity. Post-cardinal slope comparatively wide, marked by one, or
several radiating folds, which are sometimes obsolescent. Cincture dis-
tinct, extending obliquely backward from the beak to the base, giving a
sinuosity to the margin.

Surface marked by numerous fine concentric strioa. The body of the shell
is also marked by irregular concentric undulations, which are sometimes
interrupted, giving the surface a rugose appearance. The undulations ter-
minate upon the angular umbonal slope, the post-cardinal area being simply

466 PALEONTOLOGY OF NEW YORK.

striate. Anterior to the cincture the surface of the shell is marked by fine
granulaj or minute pustules.

Three specimens measure respectively 33, 62 and 105 mm. in length, and
13, 22 and 30 mm. in height.

As compared with C. clongata, the shell is more distinctly recurved, the cinc-
ture is stronger and the granulose striae are finer. It differs from all other
species in the strong irregular concentric undulations on the body of the shell.

Formation and localities. In the Hamilton group, at Sherburne, Pratt's falls
and Delphi ; and on the shore of Canandaigua lake, N. Y. Mr. Conrad cites
the species from near Smyrna, Chenango county, N. Y.

CiMITARIA ELONGATA.

PLATE LXXVII, FIGS. 5-8.

Cypricardlteji ehmgatiu), Conrad. Geol. Surv. N. Y., Ann. Rep., p. 51. 1841.
Cimitaria elongata (Conrad), Hall. Prelim. Notice Lamellibrancliiafa, 2, p. (')9. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 77, figs. ii-S.

1883.

Shell below the medium size, as compared with other species of the genus,
sub-ensiform ; length about two and one-half times the height ; basal margin
gently curved, slightly sinuate anterior to the middle. Posterior extremity
obliquely truncate above. Cardinal line es.sentially .straight. Anterior end
short, obliquely truncate from the beak, abruptly rounded below. Lunule
very long and sharply defined.

Valves depressed-convex in the lower and posterior portions, and gibbous
in the umbonal region.

Beaks sub-anterior, prominent, appressed and incurved, Umbonal slope
obtusely sub-angular, extending to the posterior extremity. Post-cardinal
slope concave anteriorly, and becoming flattened at the posterior extremity.
Cincture a broa<l undefined depression, extending from the beak to the base
of the shell, giving a slight sinuosity to the margin.

Surface marked by fine concentric striae, which .an; somewhat irregularly
fasciculate, especi.ally on the anterior and posterior portions of the shell.

LAMELLIBRANCHIATA. 467

The surface of the anterior and middle portions of the shell is minutely pus-
tulose and marked by extremely fine radiating striae, which extend obliquely
backward from the beak.

Three specimens measure respectively 43, 50 and 52 mm. in length, and
17, 19 and 22 mm. in height.

This species is distinguished by its straight cardinal line and the gentle curva-
ture of the basal margin, and by the fact that the umljonal ridge extends to the
posterior extremity at about the middle of its height, while in the other species
it extends to the post-inferior extremity.

Formation and localities. In the Hamilton group at Pratt's falls, Onondaga
county, and in Schoharie county, N. Y.

CiMITARIA RECURVA.

• PLATE LXXVir, FIGS. O-U, 16.

Cjtpricardites remirva, Cokrad. Jour. Arail. Nat. Sc.i., Pliila., vol. viii, p. 24.'), ]>!. IS, tig-. 18. 1842.
Plerium pnmtuJata, Cosrad. Gool. Surv. N. Y., Ann. Rep., p. 116. 1838.
CyprU-ardites reaii-va, Vani'XKM. Geol. Sui-v. N. V., Rep. Third Dist., pp. 152-3. 1842.
dmUaria recurva (Cokrad), Hall. Prelim. Notice Lamellibrtinchiata, 2, p. t>8. 1870.
In part " " " " Pal. N. Y., vol. v, pt. 1. Plates and Explanation.s : PI. 77, figs. 9-1(5.

1883.

Shell large, falcate ; length nearly three times the height. Basal margin
broadly curving with a slight sinuosity toward the anterior end. Posterior
extremity broadly rounded or sub-truncate. Cardinal line long, concave.
Anterior end short, broadly rounded, obliquely truncated above by the lunule.
Escutcheon large. Lunule long and abruptly limited.

Valves depressed-convex in the basal and posterior portions, becoming
gib))Ous above and in the umbonal region.

Beaks sul)-anterior, prominent, appressed and closely incurved. Umbonal
slope obtusely angular, curving downward and becoming obsolescent before
reaching the post-inferior extremity. Post-cardinal slope broad, flattened or
slightly concave. Cincture an undefined flattening or depression, extending
from the beak obliquely backward to the base, and producing a slight sinuos-
ity in the margin.

468 PALEONTOLOGY OF NEW YORK.

Surfjwe marked by fine concentric 8tria9, which are irregularly fasciculate
and are raised into strong undulations on the anterior portion of the shell.
In well-preserved specimens the surface is also marked by fine radiating
pustulose stria3. In addition to this the post-cardinal slope is sometimes
marked by distant radii.

Four specimens measure respectively 90, 91, 92 and 108 mm. in length,
and 35, 36, 35 and 38 mm. in height.

This species is distinguished from all the preceding by its extremely falcate
form, more rounded posterior extremity and the strongly pustulose and radiat-
ing .surface.

Formation and localities. In the Hamilton group near Hamilton and Earlville,
Madison county ; Pratt's falls and Skaneateles lake, Onondaga county ; and
Mt. Upton, Chenango county, N. Y.

CiMITARIA ANGCLATA, n. Sp.

PLATE LXXVII, FIG. 15

In part Cimitaria recurva (Conkad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 77,

figs. 9-16. 1883.

Shell large, falcate ; length less than three times the height ; basal margin
gently curved, with a slight sinuosity a little in advance of the anterior third.
Posterior extremity obliquely truncate. Cardinal line concave. Anterior
end very short, almost vertically truncated by the lunule, and abruptly
rounded below.

Valves moderately convex below, depressed on the posterior slope, and
gibbous in the umbonal region.

Beaks sub-anterior, prominent and incurved. Umbonal slope prominent,
distinctly angular, the angularity extending to the post-inferior extremity.
Post-cardinal slope broad, tlat or slightly concave. Cincture an undefined
depression, extending from the beak to the base and giving a slight sinuosity
to the margin.

Surface marked by fine regular concentric striae which are .somewhat fas-

LAMELLIBRANCHIATA. 469

ciculate on the anterior and posterior extremities. The strise recurve over
the umbonal ridge, at a slightly acute angle.

The specimens are casts of the interior in sandstone, and the surface
markings are not well preserved. Anterior muscular impression large, not
deep, situated just within the margin below the lunule.

A specimen has a length of 82 mm. and a height of 30 mm.

This species resembles C. recurva, but diflfers in the strong angular umbonal
ridge, which extends to the post-inferior extremity, and by the sharp recurv-
ing of the striaB over this ridge.

Formation and localities. In the Chemung group at Chemung Narrows, and
between Elmira and Waverly, Tioga county, N. Y.

PHOLADELLA, Hall. 1870.
Pholadella kadiata.

PLATE LXXVIII, FIGS. 15-21 ; ani> PLATE XCVI, FIG. 1.

NuculUes radiata, Conrad. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 248, pL 12, fig. 16. 1842.
Pholadella radiata (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 63. 1870.

" " " ." Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 78, figs.

15-20. 1883.

" truntxUa^ Hall. Prelim. Notice Lamellibranchiata, 2, p. 64. 1870.

*' oniata, " Prelim. Notice Lamellibranchiata, 2, p. 64. 1870.

Shell from small to medium size, elongate-ovate, cuneate ; length about twice
the height. Basal margin regularly rounded, curving in a greater or less
degree according to the age of the individual. Posterior extremity more or
less obliquely, or sometimes vertically, truncate. Cardinal line straight,
sometimes a little concave. Anterior end short, obliquely truncated by the
lunule and narrowly rounded below. Escutcheon large and well-defined.
Lunule deep, marked by an abrupt incurving of the margin.

Valves, in their usual condition ot preservation, moderately convex below
and gibbous in the middle. In a well-preserved specimen the valves are
very gibbous, the depth of both valves being equal to the height of the shell.

Beaks sub-anterior, prominent, strongly incurved. Cincture extending
60

470 PALEONTOLOGY OF NEW YORK.

from the beaks to the base of the shell as a marked depression and producing
a slight sinuosity in the margin. Umbonal slope prominent, often distinctly
angular, extending to the post-inferior extremity. Post-cardinal slope gently
concave, often marked by a slight fold along the middle or by two or more
radii.

Surface marked by fine concentric striae, and by strong radii diverging
from the beak, usually marking that portion of the shell between the cinc-
ture and the umbonal ridge, sometimes covering the entire surface

Four specimens measure respectively 19, 22, 28 and 36 mm. in length, and
10, 11, 13 and 18 mm. in height. The largest specimen observed has a length
of 43 mm.

The majority of the specimens are of young individuals and present a con-
siderable variety of iispect, chiefly, however, in the development of the radii
upon the surface, of which there are sometimes not more thfin six or seven
upon the body of the shell, while in other examples these radii cover the entire
surface. The specimens also vary considerably in the form of the posterior
extremity, which is sometimes narrowly rounded, often obliquely or vertically
truncjite. An examination of a sufficient number of specimens shows no
rea.son for retaining the species heretofore indicated as P. trnncata and P. ornata.

Formations and localities. In the shales of the Hamilton group in Schoharie
county ; near Fabius and at Pratt's falls in Onondaga county, and in some con-
cretionary layers at Eighteen-mile creek, Lake Erie shore, N. Y. It is found
in the same horizon near Cumberland, Md. ; also in the lower part of the Che-
mung group at Ithaca, N. Y.

Pholadella parallela.

I'LATK i.xxvni, KIUS. -la-H.

OrammyxM pnrajleta. Hall. I'pf'lim. Notico LnmcHiI>ranchiatii. 2, p. 59. 1H70.

P/iolatUUa " " Pal. N. v., vol. V, pt. 1. Plalos luul Kxplaiuitions : PI. 78, %s. 22-24. 1883.

Shem. small, .short, ovate-cuneate; length less than twice the height; basal
margin gently curving or nearly straight. Posterior extremity obliquely

LAMELLIBRANCHIATA. 471

truncate. Cardinal line straight. Anterior end short, obliquely truncate
above, and narrowly rounded below.

Valves of moderate convexity below and posteriorly, gibbous in the umbo-
nal region.

Beaks sub-anterior, prominent, arcuate and projecting above the hinge-
line. Cincture obscure, scarcely perceptible, except toward the base of the
shell, where it produces a slight sinuosity in the striae and basal margin.
Umbonal .slope distinctly angular, extending to the post-inferior extremity.
Post-cardinal slope wide, distinctly limited.

Surface marked by fine concentric .stria;, which become fasciculate, and
by strong undulations on the anterior and middle portions of the shell.
Radiating striae sometimes mark the body of the shell, but are often obscure
or obsolete.

Three specimens measure respectively 10, 16 and 18 mm. in length, and
6, 9 and 9.5 mm. in height.

This .species bears much resemblance to P. radiata, but the prevailing forms
are smaller, the concentric undulations are much stronger and the radii are
obscure or obsolete. This form, however, may prove to be only the immature
condition of P. radiata.

Formation and localities. In the shales of the Hamilton group, at Fabius, and
on the shore of Skaneateles lake, N. Y.

Pholadella Newberryi.

PLATE LXXVUT, FIG. K.

PholarMla Nrwl>err!ji. Hku.. Prelim. Notice Lamellibi-anchiatfi, 2, p. fi.'i. 1870.

Pal. N. Y., vol. V, i>t. 1. Plates anil Kxpl.inations: PI. 78, fig. 2.5. 1883.
AllorUnna (fted-gicirkin f) pleiinqrixtha^ Mekk. Proc. Acail. N.-it. Soi., Phila, \ol. 23, p. 14. 1871.
" (CercnmynpsiJi) " " Pal. Ohio, vol. 11, p. 309, pi. 13, fiffs. 4a, b, c. 1873.

Shell large, elongate-ovate, sub-falcate; length less than twice the height.
Ba.sal margin regularly curving, with a gentle sinuosity anterior to the
middle. Posterior extremity vertically or somewhat obliquely truncate.

472 PALAEONTOLOGY OF NEW YORK.

Cardinal line concave. Anterior end short, obliquely truncate above and
narrowly rounded below.

Valves depressed-convex in the posterior and lower portions, becoming
gibbous in the middle and umbonal region.

Beaks at about the anterior fourth, prominent, strongly incurved and ris-
ing above the hinge-line. Cincture indicated by a gentle, undetined depres-
sion, extending from the beaks downward, producing a slight sinuosity in
the basal margin. Umbonal slope angular above, becoming less prominent
below and extending to the post-inferior extremity. Post-cardinal slope
broad, marked by a more or less distinct longitudinal fold.

Surface marked by fine concentric striae, which become fasciculate on the
anterior and posterior portions of the shell, and by radiating striae which
cover the body of the shell posterior to the beak, occupying the space from
the anterior side of the cincture to the umbonal ridge.

Lunule marked by an abrupt infolding of the shell, leaving an angular
margin.

Two specimens measure respectively 60 and 70 mm. in length, and 27 and
31 mm. in height.

This species is distinguished by its large size and strong raflii which cover
the. body of the shell. In its general form and expression it is very similar to
some varieties of Cimitaria recurva.

Formation and locality. In the sandstones of the Waverly group in Licking
county, Ohio.

LAMELLIBRANCHIATA. 473

PHTHONIA, Hall. 1870.

r Types P. sectifrmis and P. nodimstata. ]

Phthonia cylindrica.

PLATE LXXVIII, FIGS. 1-4.
Phthonia cyliiidrica, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 78, fig-s. 1-4. 1883.

Shell of medium size, elongate-elliptical or sub-elliptical ; length more than
twice the height ; basal margin straight or slightly concave, curving into the
posterior and anterior margins without interruption. Posterior extremity
regularly rounded, sometimes somewhat oblique on the upper posterior mar-
gin. Cardinal line very gently arching or nearly straight, about half the
length of the shell. Anterior end short, narrowed, and regularly rounded at
the extremity.

Valves moderately convex in the lower portion, scarcely gibbous in the
middle and upper portion.

Beaks sub-anterior, low, appressed, with sometimes a faint indication of a
depression extending from the beak to the basal margin Umbonal slope
not defined, rounded, arcuate, becoming obsolete before reaching the post-
inferior extremity.

Surface marked by fine, even concentric striae, and by extremely fine radi-
ating striae, which are more conspicuous along the middle and posterior por-
tions of the valve below the umbonal slope. (These striae are not sufficiently
indicated in the figures.)

Anterior muscular scar distinct.

Four specimens measure respectively 26, 27, 29 and 30.5 mm. in length,
and 11, 12, 12 and 13 mm. in height.

This species differs from the others described in its more elongate-elliptical
form, wider anterior end, and finer radiating striae, which are frequently obso-
lescent and often obsolete.

Formation and localities. In the shales of the Hamilton group, at Delphi ; at
Pratt's falls, Onondaga county ; and on the shore of Cayuga lake, N. Y.

474 PALEONTOLOGY OF NEW YORK.

PhTHONIA NODICOSTATA.

PLATE LXXVUl, FIGS. 5-9.

Phthunia nodicostata. Hall. Prelim. Notice Laiuellibraiichiata, 2, p. 71. 1870.

" " Pill. N. Y., vol. V, pt. 1. Plates and E.\planatioii8 : PI. 78, fij^s. 5-9. 1883.

Shell of medium size or larger, rhomboid-obovate ; length about twice the great-
est height as measured at the posterior end. Basal margin nearly straight
along the middle, curving gently upward anteriorly and more abruptly pos-
teriori}'. Posterior extremity obliquely sub-truncate above and rounded
below. Cardinal line straight, about half the length of the shell, oblique,
ascending posteriorly. Anterior end short, somewhat narrowly rounded.

Valves moderately convex below, becoming somewhat gibbous in the mid-
dle and umbonal region.

Beaks sub-anterior, small, low, appressed and scarcely rising above the
hinge-line. Shell somewhat flattened from the beaks backward to the base.
Umbonal slope sub-angular above, gradually merging into the general con-
vexity of the shell before reaching the post-inferior extremity.

Surface marked by fine concentric,' sub-lamellose striae ; also by strong
radii, extending from the beak over every portion of the shell, and which
are more distant from each other on the cardinal slope and anterior end.
These radii, at the crossing of the concentric strioe, are marked by transverse
nodose or pustulose elevations.

Four specimens measure respectively 23, 31.5, 34 and 35 mm. in length,
and greatest height at the posterior end, of 12, 16, 16 and 17 mm., while the
height at the beaks is 10, 14, 14 and 14 mm.

This species is distinguished by its great posterior elevation and the strong
radii marking the surface.

Formation and localities. In the shales of the Hamilton group, on the shores
of Cayuga and Canandaigua lakes ; and near Oneonta, N. Y.

LAMELLIBRANCHIATA. 475

Phthonia sectifrons.

PLATK LXXVIII, FIGS. 10-13.

Cyprivardittn stctifnms, Conhad. Jour. Acail. Nat. Sci., Phila., vol. viii, p. 245, pi. 13, fig. 8. 1842.
Pktltmiia sectlfruiis (Conrad), Hall. Prelim. Notice Lamellibrauchiata, 2, p. 70. 1870.

Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 78,
fi^. 10-13. 1883.

Shell above the medium size, elongate, sub-elliptical, somewhat obovate ;
length more than twice the height measured at the posterior end ; basal
margin nearly straight in the middle, curving gradually at the anterior and
more abruptly at the posterior end. Posterior extremity rounded below,
oblique and sub-truncate above. Cardinal line straight, more than half the
length of the shell, slightly oblique, rising posteriorly. Anterior end short,
narrowly rounded.

Valves depressed-convex along the basal and posterior portions, becoming
somewhat gibbous in the middle and above.

Beaks sub-anterior, small, low and appressed. Umbonal slope obtusely
sub-angular in the upper part, usually becoming merged in the general con-
vexity before reaching the post-inferior extremity. Above this, and slightly
diverging, is another low ridge extending to the middle of the posterior end,
and limitiug the post-cardinal slope.

Surface marked by fine concentric striae, and by numerous fine radii
extending from the beak to all parts of the shell. The radii on the umbonal
ridge and anterior end are stronger than those on the middle of the shell.
At the crossing of the radii and concentric striae, the test is raised into
minute elongate nodes, and'on the post-cardinal slope the concentric striae
and radii are nearly of equal strength, giving a cancellated and peculiar aspect
to the surface.

Three specimens measure respectively 26, 39 and 40 mm. in length, and
13, 15.5 and 17 mm. in height at the posterior end.

This species differs from P. nodicostata in its more elongate form, and much
finer radii.

Formation and localities. In the shales of the Hamilton group, in Madison
county; and at Pratt's falls, in Onondaga county, N. Y.

476 PALEONTOLOGY OF NEW YORK.

Phthonia lirata.

PLATE LXXVIII, FIG, 14.
Phthunia lirata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 78, figf. 14. 1883.

Shell small, elongate-elliptical ; length more than twice the height. Basal
margin regularly and gently curved. Posterior extremity regularly rounded.
Cardinal line nearly straight. Anterior end short, regularly rounded.

Valves regularly convex, approaching to gibbous in the umbonal region.

Beaks sub-anterior, low and appressed, scarcely rising above the hinge-line.
Umbonal slope regularly rounded, not defined.

Surface marked by fine concentric striaB, crossed by distant radii, which
are less frequent on the middle of the shell and obsolete on the anterior end.

The cardinal margin, just below the hinge-line, on the interior of the valve
is marked by two slender grooves.

The specimen described has a length of 8 mm. and a height of 3.5 mm.

This species is distinguished by its regular elliptical form, its small size and
slender, distant radii.

Formation and locality. In the Hamilton group at Norton's landing, Cayuga
lake, N. Y.

Phthonia truncata, n. sp.

PLATE XCrV, FIG. i.

Shell above the medium size, sub-trapezoidal ; length twice the height as
measured at the posterior extremity. Basal margin nearly straight, abruptly
recurving at the post-inferior extremity and curving upward in front.
Posterior extremity in the lower part almost vertically truncate, obliquely
truncate above. Cardinal line oblique, rising toward the posterior end.
Anterior end short, abruptly rounded.

Valves depressed-convex along the basal portion and on the post-cardinal
slope, somewhat gibbous in the umbonal region.

Beaks sub-anterior, small, appressed, rising very little above the hinge line.
The shell at the umbo is slightly flattened, and this feature is continued to

LAMELLIBRANCHIATA. ill

the base as a broad, undefined depression. Umbonal slope obtusely angular,
extending to the post-inferior extremity. Post-cardinal slope wide, marked
along the middle of its length by a distant fold.

Surface marked by fine concentric strige which, on the posterior part of the
shell, are somewhat fascicled. Surface also marked by fine, equal radiat-
ing striae, giving the surface a somewhat cancellated appearance. The radii
are obscure on the post-cardinal slope and are principally developed in the
umbonal depression.

The specimen described has a length of 39 mm. and a height, at the pos-
terior extremity, of 18 mm.

This species somewhat resembles P. sectifrcms, but is broader and more
abruptly truncate at the posterior end, and the umbonal ridge is more distinctly
defined.

Formation and locality. In the Chemung group, south-east of Panama, N. Y.

Phthonia nitida, n. sp.

PLATE XCIV, FIGS. 6, 6.

Shell below the medium size, narrow-elliptical ; length more than twice the
greatest height ; basal margin nearly straight, gently curving upward at the
anterior and more rapidly at the posterior. Posterior extremity rounded, a
little oblique above. Cardinal line nearly straight, or slightly arcuate.
Anterior end short, naiTOwly rounded.

Valves moderately convex below and posteriorly, becoming gibbous in the
middle and umbonal region.

Beaks sub-anterior, small, incurved and appressed. Umbo flattened, and
this feature is continued, as a broad undefined depression, to the basal margin.
Umbonal slope convex, not defined, merging into the general convexity
before reaching the post-inferior extremity.

Surface marked by fine, filiform concentric striae, which sometimes become
fasciculate on the posterior and basal portions of the shell ; and by fine radi-
ating striae extending from the beaks over the entire surface, being stronger
61

478 PALEONTOLOGY OF NEW YORK.

upon the body of the shell, more distant on the anterior end, and finer and
more closely arranged on the post-cardinal slope.

Two specimens measure respectively 18 and 23 mm. in length, and 8 and
9.5 mm. in height iit the posterior extremity.

In its surface characters this species is more nearly related to P. sedifrons,
but it is more symmetrically elliptical, more convex, the beaks more incurved
and there is no fold on the post-cardinal slope.

Formation and localities. In a shale of the Chemung group, near the level of
the Alleghany river, at Warren, Pa., associated with Echinocaris socialis and
other Phyllocarida.

ORTHONOTA, Conrad. 1841,
Orthonota undulata.

PLATE LXXVIII, KIGS. 37-42.

Orihtmota undtUcUa, Cohbad. Geol. Surv. N. Y., Ann. Rep., p. 51, pi., fig. 6. 1841.

" " Vakuxkm. Geol. Surv. N. Y., Rep. Third Dist., p. UO, fifj. 2. 1842.

" " " Hall. Pi-elim. Notice Lamellibranchiata, 2, p. 87. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI 78, figs.

37-42. 1883.

Shell large, extremely elongate, with parallel dorsal and ventral margins ;
length three times the greatest height ; basal margin nearly straight, slightly
constricted anterior to the middle. Posterior end somewhat vertically trun-
cate. Cardinal line straight, extending for about three-fourths the length of
the shell. Anterior end short, extending for a little distance along the hinge-
line and abruptly rounded.

Valves of moderate convexity.

Beaks sub-anterior, small, low, scarcely elevated above the hinge-line.
Cincture narrow, distinct, extending from the beak to the basal margin,
which is sometimes gently constricted. Umbonal ridge prominent, rounded,
limited below by a narrow furrow, and extending to the post-inferior extrem-
ity. Cardinal slope wide, marked by a distinct fold along the middle of its
length.

LAMELLIBRANCHIATA. 479

Surface marked by fine concentric striae, which are in some parts crowded
and fasciculate on the body of the shell ; marked by distinct undulations
upon the anterior end and post-cardinal slope.

Four specimens measure respectively 56, 57, 70 and 74 mm. in length, and
18, 19, 22 and 25 mm. in height at the posterior extremity.

This form is one of the typical species of the genus described by Mr. Conead,
and in the absence of any special knowledge of 0. pholadis it must be regarded
as the type. It is a common form and has been widely recognized.

Formation and localities. In the Hamilton group, at Bear's gulf and Fulton-
ham, Schoharie county ; at several places in Otsego and Onondaga coimties and
on the shores of Seneca, Cayuga and Canandaigua lakes ; and rarely in the
Genesee valley.

Orthonota cabinata.

IT-ATE l-XXVUI, I'IGS. 34, 35.

Orthonota carinata, Conrad. Geol. Siii-v. N. Y., Ann. Rep., p. T)!. 1841.

" " Hall. Prelim. Notice Lamellibranchiata, 2, p. 87. 1870.

" " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 78,

figs. 34, 35. 1883.

Shell small, elongate, cylindrical ; length more than five times the height.
Basal margin inflected, essentially straight, gradually curving anteriorly and
abruptly recurved posteriorly. Posterior extremity doubly emarginate below
and obliquely truncate above. Cardinal line long and straight, extending
the greater part of the length of the shell. Anterior end short, narrowly
rounded.

Valves regularly convex in the anterior half.

Beaks sub-anterior, low, rounded and scarcely defined. Umbonal slope
angular, the ridge extending to the post-inferior extremity and limited on the
lower side by a narrow groove. Post-cardinal slope longitudinally marked,
above the middle, by a strong angular ridge with a smaller longitudinal
ridge midway to the umbonal angle. These ridges give the posterior slope
of the shell a strongly plicate appearance and produce abrupt sinuosities in

480 PALEONTOLOGY OF NEW YORK.

the posterior margin. The unibonal angle and principal cardinal ridge arc
about equal in length and prominence.

Surface marked by fine concentric striae which are fasciculate on the body
of the shell and produce gentle undulations. The stria3 on the cardinal slope
and plications are sharply undulated and not fasciculate.

Three specimens measure respectively 25, 34 and 40 mm. in length, and 4,
4 and 6 mm. in height.

This species is much smaller and proportionally more elongate than 0. undulala
and is distinguished by the carinas on the post-cardinal slope and absence of
vertical undulations.

Formation and localities. In the shales of the Hamilton group at Vinegar-
brook glen, Norton's landing, Cayuga lake ; at Earlville, Madison county ; and
in Schoharie county. The original locality cited by Mr. Conrad is at Tinker's
falls, Onondaga county, N. Y.

OrTHONOTA ENSIFOHMIS.

PLATE LXXVIU, FIG. 36.

Orthonota enxifirrmig. Hall. Prelim. Notice Lamellibranchiatii, 2, \>. 89. 1870.

Pal. N. Y., vol. V, pt. 1. Plates ami KxplanatioiKs: PI. 78, fig. 3t). 1883.

Shell small, ensiform, sub-cylindrical ; length eight times the height ; basal
margin gently curving for the entire length of the shell. Posterior extrem-
ity obliquely truncate. Cardinal line concave, parallel to the basal margin,
extending nearly the entire length of the shell. Anterior end short and
narrowly rounded.

Valves of regular convexity throughout.

Beaks sub-anterior, inconspicuous. Umbonal slope indicated by a slender,
low ridge, extending to the post-inferior extremity. Post-cardinal slope
marked by a low, angular ridge, which is more conspicuous along the poste-
rior half of the shell.

Surface marked by fine, regular concentric strijE, which are abruptly bent
upward at the umbonal angle and undulated on crossing the post-cardinal
ridge.

LAMELLIBRANCHIATA. - 481

The specimen described is incomplete at the posterior extremity, and
had originally a length of about 42 mm. and a height of 5 mm.

This species, in its narrow and extremely elongate form, resembles 0. cari-
nata, but differs in its ensiform, arcuate character, and the absence of promi-
nent carinae on the posterior slope.

Formation and locality. In the shales of the Hamilton group, in Schoharie
county, N. Y.

Orthonota rigida, n. sp.

PLATE LXXX, FIG. 6.

In part SanffuinolHes undatus, Hai,i,. Pal. N.*y., vol. v, i)t. 1. Plates and Explanations: PI. 80,

ttgs. 5, 6. 1S83.

Shell small, trapezoidal ; length more than twice the greatest height ; basal
margin straight in the posterior half, gradually curving upward toward the
anterior end. Posterior extremity nearly vertically truncate. Cardinal line
straight, extending for three-fourths the length of the shell. Anterior end
scarcely declining from the beaks and rounded below.

Valves depressed-convex below, convex in the umbonal region.

Beaks at about the anterior fourth, small, appressed, scarcely rising above
the hinge-line. Umbonal slope angular, extending to the post-inferior
extremity. Post-cardinal slope wide, depressed, marked along the centre by
a depression, which is defined in the anterior p.art and obscure toward the
posterior.

Surface marked by fine concentric striae, and by regidar continuous con-
centric undulations, which are less conspicuous toward the basal and cardi-
n.al margins.

The specimen described has a length of 28 mm. and a height of 12 mm. at
the posterior end.

This species differs from O. undulata, in its shorter and broader form, the
umbonal slope is more distinctly angular, and is not limited by a groove below ;
the post-cardinal slope is not so strongly marked by the undulations and has no
distinct fold extending along the middle of its length.

Formation and localiti/. In the Chemung group, near Elmira, N. Y.

482 PALEONTOLOGY OF NEW YORK

OrTHONOTA (?) PARVULA.
PLATE LXV, FIOS. •-', 3 ; AND IM.ATK LXXVIII, FIGS. S9-32.

OrUionota parvula, Haix. Pi-elim. Notice Lamellibruiichiata, 2, p. 88. 1870.

" " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 78, figs. 29-32. 1883.

In jMU-t Sangu'molites truH<.-attui (Cokkad, sp.), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations:

PI. 65, figs. 1-15. 1883.

Shell small, elongate, sub-trapezoidal ; length three times the height. Ventral
and dorsal margins straight and sub-parallel. Posterior extremity vertically
or obliquely truncate below and curving forward above. Anterior end nar-
rowly and regularly rounded from the "cardinal margin.

Valves moderately convex below and posteriorly, becoming gibbous in the
middle and umbonal regions.

Beaks at about the anterior fourth, flattened and incurved, rising very little
above the hinge-line. Umbonal slope angular, extending to the post-inferior
extremity. Post-cardinal slope Hat or slightly concave, sometimes obscurely
marked by a depression or fold below the middle.

Surface marked by extremely fine, thread-like concentric striaa, which are
often lamellose on the post-cardinal slope.

Three specimens measure respectively 14, 15 and 20 mm. in length, and
4.5, 5 and 6 mm. in height.

This shell was placed under the genus Orthonota on account of its long,
straight hinge-line and absence of a lunule and any indication of external liga-
ment. The two valves are frequently in conjunction as in other species of
Orthonota. The surface markings are in no respect like 0. undulata, but do not
differ essentially from 0. carinata. Its generic relations are still in doubt.

Formation and localities. In the shales of the Hamilton group near Fulton-
ham and Summit, Schoharie county ; in Onondaga and Livingston counties ;
and on the shores of Seneca and Canandaigua lakes, N. Y.

LAMELLIBRANCHIATA. 483

SOLEN.
S. Genus P A L .E 0 S 0 L E N , n. s. g.

SoLEN (Pal^osolen) siliquoidea.

PLATE LXXVIII, FtG. 33.

Orthoiwia gUiqtioidea, Hall. Prelim. Notice Lamellibi-anchiata, 2, p. 89. 1870.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations : PI. 78, fig-, 33. 1883.

Shell solenoid ; length more than four times the greatest height. Basal and
cardinal margins sub-parallel. The cardinal margin is straight and the basal
margin extends slightly downward posteriorly. Posterior extremity abruptly
truncate, gaping. Anterior end very short, straight on the cardinal line and
regularly rounded below.

Shell sub-cylindrical. Valves regularly convex their entire length.

Beaks sub-anterior, low and undefined. Umbonal slope marked by a shal-
low, indistinct diagonal groove, which is merged in the general convexity
before reaching the post-inferior extremity. Post-cardinal slope wide,
slightly undulated.

Surface marked by fine concentric striae, the remains of which are pre-
served in the cast.

The specimen described has a length of G5 mm., a height at the beak of
10 mm., and at the posterior end of 14 mm.

This shell was originally placed under the genus Orthonota from its general
similarity in form, and from a disinclination to propose another generic name ;
but a proper limitation of that genus requires the separation of this species.

This species difters from any of the preceding in the regularly convex, cylin-
drical form of the entire shell, and the gaping posterior extremity.

Formation and locality. In the arenaceous beds of the Hamilton group in the
southern part of Schoharie county, N. Y.

484 PALEONTOLOGY OF NEW YORK.

CYPRICARDINIA, Hall. 1859.
Cypricardinia planulata.

ri,ATK LXXIX, FIGS. l-«.

PUrinea planulata, Conrai>. Jiiiir. Aoa<L Nat. Sci., Phila., vol. viii, \>. 2.")1, jil. 13, fig-, l,"). 1842.
Cj/pricardinia " " Hall. Pi-eliin. Notice Lainellibraiichiata, 2, ji. 82. 1870.

•• " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 79, figs. 1-5.

1883.

Shell large, sub-rliomboid-ovate ; length one-third greater than the height ;
basal margin broadly curving, with a shallow sinus anterior to the middle.
Posterior extremity abruptly rounded below, sinuate and truncate above.
Cai'dinal line slightly arcuate, oblique. Anterior end short, declining rapidly
from the beak, regularly rounded below.

Left valve depressed-convex below, more convex in the middle. Right
valve gibbous in the umbonal region.

Beaks sub-anterior, appressed, rising but little above the hinge-line. Cinc-
ture very distinct, extending to the base of the shell. Umbonal slope
obtusely angular, prominent, extending to the post-inferior extremity. Post-
cardinal slope broad, sinuate ju.st above the umbonal ridge.

Surface marked by fine concentric strife, and at regular intervals by
prominent concentric undulations.

Muscular impressions and pallial line, as shown in figs. 3-5, of plate Ixxix,
representing casts of the interior.

Four specimens measure respectively 15, 21, 26 and 27 mm. in length, and
10, 14, 17 and 19 mm. in height. A large specimen has a length of 30 mm.

This shell is distinguished by its large size, broad form and distinct sinuosity
extending along the post-cardinal slope, just above the umbonal ridge.

Formation and localities. In the Schoharie grit, in the Helderberg mountains,
and in Schohfirie county, N. Y.

LAMELLIBRANCHIATA. 485

Cypricardinia indenta.

PLATE LXXIX, FIGS. 6-16, 23 ; AND PLATE XCVI, FIG. 2.

Cypricardites indenta, Conrad. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 244, pi. 12, fig. 12. 1842.
In part Cypricardinia indenta (Conrad), Hall. Prelim. Notice Lamellibranchiata, 2, p. 83. 1870.

Pal. N. Y., vol. V, pt. 1. Plates and Explanations :
PI. 79, figs. 6-23. 1883.
Cypricardites inflata, Conrad. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 246, jil. 15, fig. 2. 1842.

Shell of medium size, sub-rhomboid-ovate ; length more than one-third greater
than the height; basal margin nearly straight, slightly sinuate anterior to
the middle. Posterior extremity abruptly rounded below and obliquely
truncate above. Cardinal line straight, oblique. Anterior end very short,
rounded below.

Right valve very convex, often extremely gibbous. Left valve usually
depressed-convex below and posteriorly, becoming moderately gibbous in the
umbonal region.

Beaks nearly anterior, small and appressed, rising but little above the
hinge-line. Cincture distinct on the right valve, less marked upon the left
valve. Umbonal slope rounded and prominent on the right valve, sub-
angular on the left valve.

Surface marked by extremely fine concentric striae and by unequally distant
but somewhat regular, lamellose, imbricating, concentric undulations ; and in
well-preserved specimens the entire surface is marked by fine striae, which radi-
ate from the apex of the shell, and in some conditions of preservation the sur-
face shows a second set of striae vertical to the direction of the lamellae.

Four specimens measure respectively 11, 14, 18 and 20 mm. in length,
and 7, 8, 11 and 11 mm. in height.

This species is smaller than the preceding, the right valve, when well-
preserved, is more gibbous, the depression or sinus above the umbonal slope is
not so distinctly defined, and the posterior margin is not sinuate. This spe-
cies probably includes the form described as Cypricardites inflata by Mr. Conrad,
which represents a gibbous specimen as preserved in the limestone. The speci-
mens, figs. 6, 7, 8, are from near the original locality of that species.

Formations and localities. In the Corniferous limestone, at Babcock's hill,
62

486 PALEONTOLOGY OF NEW YORK.

Oneida county, N. Y. ; at the falls of the Ohio ; and at North Cayuga, Ontario ;
in the shales of the Hamilton group, on the shores of Erie, Seneca, Cayuga,
Canandaigua, Skaneateles and Owasco lakes ; and at many other localities in
New York, and in Hardy county, Va.

Cypricardinia arcuata, n. sp.

PLATE LXXIX, FIG 17.

Ill part Cypricardinia indewla (Conrad), Hall. Pal. N. Y , vol. v, pt. 1. Plates and Explanations:

PI. 79, figs. «-23. 1883.

A single left valve of this species has been observed. It differs from C.
indenta in being more convex, and having the form and convexity of a right
valve. The umbonal slope is rounded, arcuate and not direct as in the other
species. The posterior margin is more vertically truncate, and the cincture
and sinuosity of the base are much more strongly marked.

The specimen has a length of 12 mm. and a height of 7 mm.

Other specimens are required to give a full description of the species.

Formation and locality. In the Chemung group, north of Elmira, N. Y.

Cypricardinia? cylindrica.

I'LATE LXXIX, FIGS. 24, 26.

Ogpricardiniat cylindrica. Hall and Whitfikld. Twenty-fourth Ann. Rep. N. Y. State Mus. Nat. Hist.,

p. 190. 1872.
" " " Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explana-

tions : PI. 79, figs. 24, 25. 1883.

The specimen is not accessible at the present time, and its generic relations
cannot be satisfactorily determined.

Formation and locality. The original specimen was from the Hydraulic beds
of the age of the Hamilton group, near Louisville, Ky,

Cypricardinia consimilis, n. sp.

PLATE LXXIX. FIGS. 19, 20, 21 (18?); ANU PLATE XCVI, t'IG. 3

In part Cypricardinia indenta (Cowrad), Hall. Prelim. Notice Lamellibrancliiata, 2, j>. 83. 1870.

" " " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations; PI.

79, figs. 6-23. 1883.

Shell small, sub-rhomboidal ; length nearly twice the height ; basal margin
gently curving or nearly straight. Posterior extremity extended below.

LAMELLIBRANCHIATA. 487

narrowly rounded and truncate above. Cardinal line slightly arcuate.
Anterior end short, declining abruptly from the beak and rounded below.

Right valve gibbous in the middle and umbonal region. Left valve more
depressed.

Beaks sub-anterior, appressed, rising a little above the hinge-line. Cinc-
ture shallow, undefined, continued to the basal margin. Umbonal slope
obtuse, prominent, extending to the post-inferior extremity.

Surface marked by fine concentric striae and on the middle and anterior
portion by strong regular concentric undulations, which are sometimes dupli-
cate on both .sides of the cincture, mainly on the posterior half of the shell.
Entire surface covered by fine radiating striae.

Hinge-line marked in the posterior part by a slender groove.

Three specimens measure respectively 8, 15 and 15.5 mm. in length, and
4.5, 8 and 8.5 mm. in height.

This species resembles C. indenta from the Hamilton group, but it is more
elongate, comparatively narrower at the posterior end, the umbonal slope in
the right valve is more direct than in the right valve of that species.

Formation and localities. In the Waverly sandstones, Licking and Medina
counties, Ohio, and at Warren, Pa.

Cypricaedinia sulciperus.

PLATE LXXIX, i^IG. «!.

Sang abwlitai milcif eras, Wischbll. Proc. Acad. Nat. Sci., Phila., p. 14. 1863.
In part Oypricardinia indenta (Conrad), Hall. Pielim. Notice Lamellibraiichiata, 2, p. 83. 1870.
" " " •' " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations :

PI. 70, figs. 6-23. 1883.

The figure is given from a specimen in the Yellow sandstone, at Burlington,
Iowa, and is three times enlarged. The material in our possession is not suffi-
cient to determine its intimate relations with the other species. It is, how-
ever, marked with fewer undulations than any other form here described.

488 PALEONTOLOGY OF NEW YORK.

PALiEANATINA, Hall. 1870.
Pal^anatina typa, Hall. 1870.

I'LATE I.XXIX, FIGS. 2t^-28, 85-S7.

PalaatuUitM typ<i, Sai,l. Pi-elim.Notice Lamellibi-anchiata, 2, p. 85. 1870.

In part " " " Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 79, fiffs. 20-39. 1883.

Shell short-soleniibrni, elongate, sub-elliptical; length twice the height; basal
margin slightly sinuate in the middle, often nearly straight and sometimes
gently curving. Posterior extremity abruptly rounded, often sub-truncate.
Cardinal line straight, or slightly arcuate. Anterior end short, regularly
rounded.

Valves unequally convex, and apparently slightly gaping at both extrem-
ities. Left valve somewhat gibbous in the umbonal region. Right valve
depressed-convex.

Beaks in advance of the anterior third, appressed, rising but little above
the hinge. Cincture very broad, undefined, affecting the lower half of the
valve, producing a broad sinuosity in the margin. Umbonal slope obtusely
sub-angular, extending to the post-inferior extremity. Cardinal slope nearly
Hat or slightly concave, with a narrow fold developed near the cardinal line.

Surface marked by fine concentric striae, which are frequently irregularly
fasciculate on the basal portion of the shell.

Four specimens measure respectively 16, 20, 28 and 31 mm. in length,
and 7.25, 10, 14 and 15 mm. in height.

The shells of this species vary considerably in form and expression. The
umbonal ridge and the post-cardinal fold are variously developed, the umbonal
slope being often scarcely angular, and the fold on the cardinal slope some-
times obsolete. The cincture is also sometimes excessively developed, produc-
ing a deep and broad sinuosity in the margin. But few specimens of the right
valve have been observed ; these are depressed, the umbonal slope subdued, the
l)eaks inconspicuous and without any evidence of a fold on the cardinal slope.

Formation and locality. In the conglomerate of the Chemung group, at Port-
ville, Cattaraugus county, N. Y.

LAMELLIBRANCHIATA. 489

PaljEanatina solenoides, n. sp.

PLATE LXXIX, FIGS. 38, 3a.
In part PaUBaTiatina typa. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 79, fig-s. 26-39.

Shell elongate, sub-quadrate ; ventral and dorsal margins sub-parallel ; length
two and one-half times the height ; basal margin nearly straight or a little
contracted anterior to the middle. Posterior extremity almost vertically
truncate. Cardinal line straight. Anterior end short, the upper side
extended in continuation with the cardinal line, and curving below.

Left valve regularly convex, scarcely gibbous in the umbonal region.
Right valve depressed-convex throughout.

Beaks at about the anterior fourth, that of the left valve rising a])ove the
hinge-line and incurved ; in the right valve scarcely rising above the cardi-
nal line. In the left valve there is a flattening of the beak, and a broad
undefined depression below, extending to the basal margin. Umbonal slope
of the left valve obtusely sub-angular for a short distance from the beak,
merging into the general convexity before reaching the middle of the shell.
In the right valve the umbonal ridge is obsolete. Cardinal slope not dis-
tinct from the general convexity.

Surface marked by fine concentric striae, which become fasciculate on the
posterior slope, and are nearly vertical to the hinge-line.

The ligamental area is comparatively short, about one-fourth the length of
the shell.

The specimen described has a length of about 42 mm. and a height of 17
mm.

This shell is more elongate than the preceding, the cardinal margin is more
extended and straighter, the posterior end truncate ; the umbonal ridge is less
defined, and there is no evidence of a fold upon the post-cardinal slope.

Formation and locality. In a conglomerate of the Chemung group, near Port-
ville, Alleghany county, N. Y.

490 PALAEONTOLOGY OF NEW YORK.

PALiEANATINA ANGDSTA, n. sp.

PLATE LXXIX, FIGS. 21KJ4.

In part Patttanatina typo. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 79, figB. 26-39.

1883.

Shell small, elongate, narrowly elliptical or sub-cylindrical ; length from two
and a halt" to three times the height ; basal margin straight or slightly sinu-
ate. Posterior extremity obliquely truncate or regularly rounded. Cardinal
line straight or slightly declining posteriorly. Anterior end narrow, rounded.

Left valve gibbous in the umbonal region. Right valve less gibbous and
more depressed below the umbonal ridge.

Beaks between the anterior third and fourth, small, scarcely rising above
the hinge. Umbonal slope obtusely sub-angular, extending to the post-
inferior extremity. Post-cardinal slope flat or concave, with a fold in the
left valve, a feature not observed in the right valve. There is a shallow
undefined depression extending from the umbo to the base, scarcely affecting
the margin.

Surface marked by fine concentric striae, which become fasciculate on the
posterior end of the shell.

Five specimens measure respectively 21, 24, 26.5, 30 and 32 mm. in
length, and 9, 10, 10, 10 and 10 mm. in height.

Compared with either of the preceding species this shell is comparatively
smaller, more elongate, and the difference in the convexity of the valves is less
conspicuous.

Farther collections may show the necessity of separating such specimens as
are represented in figure 30 of plate Ixxix.

Formation and locality. In a conglomerate of the Chemung group, near Port-
ville, Alleghany county, N. Y.

LAMELLIBRANCHIATA. 491

PaljEanatina sinuata, n. sp.

PLATE XCVI, FIG. 4.

Shell small, obovate, length about twice the height ; basal margin gently
curving, straight in the middle. Posterior extremity rounded below and
truncate above. Cardinal line gently arcuate. Anterior end narrow,
rounded.

Left valve depressed-convex below, becoming gibbous in the umbonal
region. Right valve unknown.

Beaks at about the anterior fourth, low, scarcely rising above the hinge-
line. The valve, from the beak downward, is depressed, but without a
distinct cincture. Umbonal slope prominent, obtusely sub-angular, limited
above by a distinct groove or sinus extending to the post-inferior extremity.
Cardinal slope convex, limited below by the sinus bordering the umbonal
ridge. The cast of the interior preserves the remains of fine concentric
striae, which were abruptly sinuate in passing over the umbonal ridge and
sinus.

A specimen has a length of 21 mm. and a height of about 12 mm.

This species is shorter and broader than any of the preceding, and is readily
distinguished by the defined umbonal ridge, with the narrow sinus on the
upper side.

Formation and locality. In the Chemung group, at Warren, Pa.

492 PALEONTOLOGY OF NEW YORK.

PRORHYNCHUS, n. g.

Prorhynchus quadratom.

PLATE LXXIX, FIGS. «M9 ; ANl> PLATE XCVI, FIG. 6.

Palcuinatina quadrata (Hall). 8. A. Millkr. Cat. Am. Pal. Foss., p. 199. 1877.

" " Hall. Pal. N. Y.. vol. v, pt. 1. Plates and Explanations : PI. 79. tig«. 40-49. 1883.

Shell large, inequivalve, quadrate, sub-rhomboid ; length usually more than
one-third greater than the height ; basal margin straight or gently rounded,
curving upward in front. Posterior extremity almost vertically truncate.
Cardinal line straight. Anterior end produced above, sub-nasute, obliquely
truncate or gently rounded below.

Left valve depressed-convex below, becoming gibbous in the middle, and
especially in the umbonal region. Right valve depressed-convex, almost flat.

Beaks at about the anterior third, appressed, rising but little above the
hinge. Umbonal slope of the left valve obtusely angular, somewhat arcuate,
extending to the post-inferior angle. Post-cardinal slope broad, marked by
an obscure fold below the middle of its length.

Surface marked by fine concentric striae, the impressions of which are left
on the cast of the interior.

The cast shoAvs some striae or grooves on the posterior portion of the car-
dinal line ; anterior to the beaks there is a groove along the hinge, and a
distinct narrow, divergent furrow, extending from the beak half way to the
anterior margin.

Four left valves measure respectively 19, 21, 38 and 45 mm. in length,
and 12, 15, 22 and 28 mm. in height. Three right valves measure respect-
ively 22, 24 and 32 mm. in length, and 13, 13.5 and 17 mm. in height.

This shell is remarkable for its sub-quadrate, rhomboidal form, long straight
hinge-line and the angular or sub-nasute anterior extremity.

Formation and locality. In a coarse sandstone in the upper part of the Che-
mung group, south of Smethport, Pa.

LAMELLIBRANCHIATA. 493

Prorhynchos nasutum, n. sp.

PLATE XCVI, FIG. 6.

Shell of medium size, sub-rhomboid-obovate ; length more than one-third
greater than the height; basal margin nearly straight, curving upward in
front. Posterior extremity almost vertically truncate. Cardinal line straight.
Anterior end nasute above, rounded below.

Left valve depressed-convex in the lower part, gibbous in the upper and
umbonal regions. Right valve depressed-convex, scarcely gibbous above.

Beaks anterior to the middle, appressed, incurved, scarcely elevated above
the hinge-line in the left valve. In the left valve there is a broad undefined
depression, extending vertically from the umbo to the base. Umbonal slope
obtusely angular and broad in the left valve, less conspicuous in the right,
extending to the post-inferior angle. Post-cardinal slope broad, limited by
a shallow longitudinal depression just above the umbonal ridge.

Surface marked by fine concentric striae, which are sometimes fasciculate.

A specimen has a length of 25 mm. and a height of 18 mm., the length,
including the nasute anterior extension, is 29 mm.

This species is distinguished from the preceding by its proportionally greater
height, more nearly central beaks, broad umbonal ridge, the nasute anterior
extremity and the greater convexity of the right valve.

Formation and locality. In the upper part of the Chemung group, at Warren,
Pa.

Proriiynchus angulatum, n. sp.

PLATE XCVI, FIG. 7.

Shell large, sub-rhomboidal ; length and height as five to three ; basal margin
nearly straight, oblique to the hinge-line. Posterior extremity obliquely
truncate, slightly sinuate in the middle. Cardinal line elongate, straight.
Anterior end long, narrow, produced above, angular at the extremity and
retrally truncate below, to the antero-basal angle.
63

494 PALEONTOLOGY OF NEW YORK.

Right valve depressed-convex, slightly concave from the beak to the base
in a broad undefined depression. Left valve unknown.

Beaks behind the anterior third, low, inconspicuous. Umbonal slope
defined, prominent, extending to the post-inferior angle, which is abruptly
rounded, limited on the up; :r side by a distinct furrow, which produces a
slight sinuosity in the margin. Post-cardinal slope broad.

Surface marked by fine concentric striae.

A specimen has a length of 53 mm. and a height of 30 mm. at the poste-
rior end, and of 20 mm. at the beak.

This shell is distinguished by its large size, extremely long cardinal line, the
retrally truncate anterior end, and the sinuate posterior extremity.

Formation and locality. In the upper part of the Chemung group, at Warren,
Pa.

GLOSSITES, N. G.
Glossites teretis, n. sp.

PLATE XCVI, FIG. 18.

Shell below the medium size, elongate, sub-elliptical, narrower in front ; length
more than twice the greatest height ; basal margin broadly curved, sinuate
anterior to the middle. Posterior extremity narrowly rounded, and with the
margin above sloping acutely forward. Cardinal line slightly oblique, about
half the length of the shell. Anterior end short, descending from the beaks
and narrowly rounded below.

Valves of moderate convexity below, becoming gibbous in the umbonal
region.

Beaks sub-anterior, small, rising but little above the hinge-line. Umbonal
slope convex, continued to the post-inferior extremity. Cardinal slope nar-
row. There is a shallow, undefined cincture extending from the beaks to
the anterior part of the basal margin.

Surface marked by fine striae of growth which are aggregated into irregu-
lar fascicles on the body of the shell and umbonal slope. Interior unknown.

LAMELLIBRANCHIATA. 495

The specimen described has a length of 34 mm., a height in the middle of
16 mm., and the depth of both valves is 9 mm.

This species is the only one of the genus yet noticed in the Upper Helderberg
group. It somewhat resembles G. lingualis, from the Chemung group, but the
anterior end is much shorter and more rapidly declining from the beaks, which
are more elevated, the umbonal slope is more convex, and the cardinal slope
is comparatively narrower.

Formation and locality. In the Corniferous limestone at Littleville, near
Avon, Livingston county, N. Y.

Glossites subtenuis, n. sp.

PLATE XL, FIGS. 12, 20.

In part Modiomorpha i amygdalina (Winchbll), Hall. Prelim. Notice Lamellibranchiata, 2, \> 78. 1870.
" " " " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations :

PI. 40, figra. 12-20. 1883.
finl SanffuinoHteg amygdalinus, Winchell. Proc. Acad. Nat. Sci., Phila., p. 13. 1863.

Shell small, elongate-elliptical ; length twice the height ; basal margin very
gently curved, turning abruptly to the anterior and posterior. Posterior
extremity regularly rounded. Cardinal margin nearly straight. Anterior
end short, without limitation, gently declining from the beak and abruptly
rounded at the extremity.

Valves depressed-convex in the basal and posterior portions of the shell,
becoming moderately convex in the umbonal region.

Beaks sub-anterior, small, closely appressed. Umbonal slope not defined.

Test thin, marked by fine concentric striae, which are fasciculate upon the
umbonal slope and posterior region, giving prominent undulations to the
surface. Interior unknown.

One of the specimens described has a length of 32 mm. and a height of 15
mm. A comparatively broader specimen measures 30 mm. in length and 15
mm. in height.

Compared with G. amygdalina, this species has a narrower shell with a
shorter anterior end ; the posterior end is narrower and the striae curve and

496 PALEONTOLOGY OF NEW YORK.

become almost parallel to the cardinal border, while in that species the stria3
terminate abruptly at the cardinal linf..

Formation and locality. In the central portion of the Hamilton group, near
Geneva, N. Y.

Glossites depressus, n. sp.

PLATE XL, FIGS. 15, 17 ; AND PLATE XCVI, FIG. 12.

In part Modwmorpha t amygdalina (Winchbli,), Hall. Prelim. Notice Lamellibranchiata, 2, p. 78. 1870.

" Pal. N. Y., vol. V, pt. 1. Plates and Explana-
tions : PI. 40, figs. 12-20 1883.
Not SanfftiinolUes amygdalinus, 'WiifcuKi,!,. Proc. Acad. Nat. Sci., Phila., p. 13. 18B3.

Shell above the medium size, sub-elliptical, wider behind ; length about twice
the height ; basal margin gently curved to near the extremities, where it
rapidly recurves. Posterior extremity abruptly rounded, obliquely sub-
truncated on its upper portion. Cardinal margin gently arcuate for its
entire length. Anterior end slightly produced, rapidly declining from the
beak and narrowly rounded below.

Valves depressed-convex in the posterior and basal portions, becoming
moderately convex in the umbonal region.

Beaks sub-anterior, small and closely appressed, scarcely rising above the
hinge-line. Umbonal slope not defined.

Surface marked by fine concentric striae, which are fasciculate upon the
middle and posterior portions of the shell, producing undulations of the sur-
face which are sometimes strongly marked in the cast.

Anterior muscular impression shallow, close to the anterior margin.

One of the specimens described has a length of 50 mm. and a height of 26
mm. A smaller individual measures 47 mm. in length and 24 mm. in height.

This species closely resembles G. lingualis, but the anterior end is propor-
tionally shorter and the vjilves are more expanded posteriorly.

Formation and localities. In the shaly sandstones of the middle portion of the
Chemung group, at Buck's quarry, north-west of Elmira, associated with Orthis
impressa ; and near Elmira, associated with Orthis Tioga and Leptodesma protextum.

LAMELLIBRANCHIATA. 497

Glossites lingualis, n. sp.

PLATE XL, FIGS. 16, 19 ; and PLATE XCVI, FIGS. 9 11.

In part Modiomorphaf amygdalina (Wiitcubll), Hall. Prelim. Notice Lamellibranchiata, 2, p. 78. 1870.
" " " " " Pal. N. Y., vol. V, pt. 1. Plates and Explana-

tions : PI. 40, figs. 12-20. 1883.
Not Sanguinolites amygdalimis, Winchbll. Proc. Acad. Nat. Sci., Phila., p. 13. 1863.

Shell of medium size or larger, elongate-sub-elliptical ; length usually a little
more than twice the height ; basal margin gently curved. Posterior extrem-
ity narrowly rounded. Cardinal margin slightly arcuate. Anterior end
somewhat produced, declining from the beaks to about the middle of the
height and abruptly rounded below.

Valves depressed-convex below the middle and on the posterior portion,
becoming moderately convex in the umbonal region.

Beaks at about the anterior fourth or fifth, small and closely appressed,
not rising above the hinge-line. Umbonal slope not defined. Some speci-
mens show a slight flattening or constriction of the valves extending from
the beaks to the base.

Test marked by fine striae of growth, which are often fasciculate on the
body of the shell producing undulations of the surface.

The cardinal border is distinctly flattened and there are indications of an
elongate tooth posterior to the beaks. The upper anterior margin is also flat-
tened in the cast, and this feature probably indicates the limits of the lunule.

Four specimens measure respectively 30, 32, 39 and 56 mm. in length, and
14, 14, 18 and 25 mm. in height.

This species is distinguished from G. depressus by its longer anterior end,
more elongate elliptical form ; and the cardinal line is not oblique, as in that
species.

Specimens are abundant in some parts of the Chemung group, and are sub-
ject to considerable variation, due to the nature of the matrix and the condi-
tion of preservation.

Formation and localities. In the Chemung group at Phillipsburgh, N. Y., and
at Mansfield, Pa.

498 PALEONTOLOGY OF NEW YORK.

GlOSSITES ELLIPTICUS, n. sp.

PI^TK XCVl, FIG. 8.

Shell above the medium size, elongate-elliptical; length more than twice the
height ; basal margin very gently curved, nearly straight in the middle.
Posterior extremity narrowly rounded, extending obliquely forward above to
the hinge-line. Cardinal line gently arcuate. Anterior end obliquely trun-
cate above by the long lunule, and abruptly rounded below.

Valves depressed-convex in the lower and posterior portion, becoming con-
vex in the middle and umbonal regions.

Beaks at about the anterior fifth, small and closely appressed, rising but
very little above the hinge. Umbonal slope moderately convex above, not
defined toward the post-inferior extremity.

Surface marked by fine concentric striae, which are fasciculate on the
body of the shell, producing somewhat regular undulations. Interior
unknown.

The specimen described has a length of 59 mm. and a height of 25 mm.

This species is distinguished by its regular elongate-elliptical form. The
specimen, forming the basis of the description, retains both valves and preserves
the hinge ligament. The ligament is strong and extends backward from the
beaks about 19 mm.

Formation and locality. In a fine-grained sandstone of the Chemung group,
at Mansfield, Tioga county. Pa.

Glossites budicula, n. sp.

I'LATK XCVI, FIG. 17.

Shell of medium size, elongate-elliptical, wider behind the middle ; length more
th.an twice the height ; basal margin gently curved in the posterior portion,
becoming nearly straight anterior to the middle. Posterior extremity nar-
rowly rounded, with the upper margin extending very obliquely forward to
the hinge. Cardinal line slightly oblique and gently arcuate. Anterior end
narrow, sloping rapidly from the beak and abruptly rounded at the extremity.

LAMELLIBRANCHIATA. 499

Valves depressed-convex in the lower and posterior portion, becoming con-
vex in the umbonal region.

Beaks at about the anterior fifth, small and appressed, rising but little
above the hinge-line. Umbonal slope convex above, not defined toward the
post-inferior extremity.

Surface marked by fine concentric striae, which are fasciculate, and pro-
duce undulations of the surface at irregular intervals, and are more con-
spicuous on the posterior half of the shell. Anterior muscular scar situated
just below the lunule, near the anterior extremity. Cardinal margin flat-
tened as in other species of this genus.

Two specimens measure respectively 40 and 51 mm. in length, and 17 and
22 mm. in height.

This species resembles G. depressus, but is distinguished by its greater con-
vexity, more elongate form, and much more extended anterior end.

Formation and locality. In a red sandstone of the Chemung group, at Nelson,
Tioga county. Pa.

Glossites procerus, n. sp.

PLATE XCVI, FIG. 13.

Shell above the medium size, elongate-sub-elliptical, narrower in front ; length
two and one-half times the height; basal margin gently curved, abruptly
rounded into both extremities. Posterior margin recurved to the hinge-
line. Cardinal line gently arcuate. Anterior end produced, declining from
the be<aks and narrowly rounded in the lower part.

Valves depressed-convex in the lower and posterior portions, becoming
moderately convex along the middle and in the umbonal region.

Beaks at about the anterior fifth, small and closely appressed. Umbonal
slope not strongly defined, but the convexity continues to the post-inferior
extremity.

Surface marked by fine striae of growth, which are sometimes fasciculate,
forming concentric undulations. Anterior muscular scar strongly developed.

600 PALEONTOLOGY OF NEW YORK.

The specimen described has a length of 57 mm. and a height of 22 mm.

This species is distinguished from G. lingualis in its more elongate form, nar-
rower anterior end and by the convexity of the umbonal slope continuing to
the post-inferior extremity.

Formation and locality. In a micaceous red sandstone of the Chemung group,
at Mansfield, Tioga county, Pa.

Glossites subnasutcs, n. sp.

PLATE XCVI, FIU. U.

Shell of medium size, elongate-sub-elliptical; length more than twice the
height ; basal margin gently curved, nearly straight in the middle. Poste-
rior extremity produced and sub-nasute below, curving forward above to the
hinge-line. Cardinal line gently arcuate, about half the length of the shell.
Anterior end declining from the beak and narrowly rounded.

Valves depressed-convex below and posteriorly, becoming convex in the
middle and above.

Beaks at about the anterior sixth, directed forward, low and appressed,
rising but little above the hinge-line. Umbonal slope convex, continuing to
the post-inferior extremity, and producing a sub-nasute extension of the
margin.

Surface marked by fine concentric striae, which are often fasciculate, and
sometimes produce regular undulations of the surface on the umbo.

Two specimens measure respectively 44 and 38 mip. in length, and 18 and
16 mm. in height.

This species is distinguished by the nasute extension of the post-inferior
extremity, in which character it dift'ers from any other species here described.

Formation and locality. In a sandstone of the Chemung group, at Mansfield,
Tioga county, Pa.

LAMELLIBRANCHIATA. 501

Glossites patulus, n. sp.

PLATE XCVI, FIGS. 15, 16.

Shell of medium size or larger ; length less than twice the height ; basal mar-
gin gently curved posteriorly, becoming nearly straight anterior to the mid-
dle. Posterior extremity abruptly rounded below, and obliquely sub-truncate
above. Cardinal line depressed, oblique, and gently arcuate. Anterior end
obliquely truncated by the lunule and narrowly rounded below.

Valves depressed-convex in the lower and posterior portions, becoming
moderately convex in the umbonal region.

Beaks at the anterior fourth or fifth, small and closely appressed. Umbo-
nal slope convex above, becoming depressed toward the post-inferior
extremity.

Surface marked by fine striae of growth, which are fascicled and produce
concentric undulations on the body of the shell. Anterior muscular scar
moderately impressed, situated just within the anterior border below the
lunule.

Four specimens measure respectively 28, 36, 45 and 50 mm. in length, and
17, 20, 25 and 28 mm. in height.

This species is distinguished by its broad, flattened form, in which characters
it diflers from any other species of the genus noticed in this volume.

Formation and localities. In the Chemung group, at Rockville, N. Y., and
Mansfield, Pa.

Glossites amygdalinus.

PLATE XL, FIGS. 13, U.

SanguinulUes aiaygdalinus, Winchell. Proc. Acad. Nat. Sci., Phila., p. 13. 1863.

In part Modionuyrpha f amygdalina (Winchell), Hall. Prelim. Notice Laraellibranchiata, 2, p. 78. 1870.
•• " " " " Pal. N. Y., vol. V, pt. 1. Plates and Explana-

tions : PI. 40, figs. 12-20. 1883.

Shell below the medium size, sub-elliptical ; length a little more than twice the
height. Basal margin gently curved, abruptly rounded into both extremi-
64

502 PALJEONTOLOGY OF NEW YORK.

ties. Posterior extremity rounded, nearly vertically sub-truncate above.
Cardinal line slightly arcuate. Anterior end short, declining rapidly from
the beaks and abruptly rounded below.

Valves depressed-convex in th,e lower and posterior portions, becoming
convex in the umbonal region.

Beaks at about the anterior fifth, small and closely appressed. Umbonal
slope not defined.

Surface marked by fine striae of growth which are fasciculate on the body
of the shell and form undulations at irregular intervals. Interior unknown.

A specimen has a length of 35 mm. and a height of 17 mm.

This species somewhat resembles G. depressus, but the beaks are farther from
the anterior extremity, the cardinal line is not oblique, and the valves are nar-
rower behind.

Formation and locality. In the Yellow sandstones at Burlington, Iowa.

ELYMELLA, n. g.
Eltmella fabalis, n. sp.

PLATE XL, FIGS. 5, 9.

In part ModUnaorphaf hyatea. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 40, figs.

5-11. 1883.
Not " " " Prelim. Notice Lamellibranchiata, 2, p. 79. 1870.

Shell small, sub-elliptical, narrower in front ; length more than one-half
greater than the height; basal margin regularly convex, curving more
gently to the anterior and more abruptly to the posterior. Posterior end
symmetrically rounded ; cardinal margin nearly straight, gently sloping
posteriorly. Anterior end very short, declining abruptly from the beak and
narrowly rounded below. Lunule deeply impressed.

Valves regularly convex posteriorly, becoming gently gibbous in the
middle and umbonal region.

Hinge-line direct, about half the length of the shell.

Beaks anterior, rounded and closely appressed. Umbonal ridge not defined.

LAMELLIBRANCHIATA. 503

Test thin, marked by fine, regular concentric striae, which become crowded
on the anterior end and sometimes fasciculate on the body of the shell.
Interior unknown.

A medium-sized specimen has a length of 14 mm. and height of 8 mm.
A larger specimen measures 15 mm. in length and 9 mm. in height.

This species is distinguished by its small size, regularly curving base, and
symmetrical posterior extremity.

Formation and localities. In the soft shales of the Hamilton group, on the
shores of Seneca and Cayuga lakes.

Elymella nuculoides, n. sp.

PLATE XL, FIOJS. 6, 7, S, 10?

In piirt ModUnnorpha 1 liyalea. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 40, figs.

5-11. 1883.
Not " " " Prelim. Notice Laraellibranchiata, 2, p. 79. 1870.

Shell small, broad, obliquely ovate ; length more than one-half greater than
the height ; basal margin regularly curving, more abruptly recurving at the
anterior end ; posterior margin regularly rounded, recurving into the cardi-
nal line, which is straight for half its length. Anterior end short, regularly
rounded.

Valves moderately convex on the posterior and ventral portions, becoming
gibbous in the middle and umbonal regions.

Hinge-line straight, extending a little less than half the length of the shell.

Beaks anterior, prominent and incurved, rising little above the hinge-line.
Umbonal region regularly gibbous, without defined ridge. When the shell
is partially compressed, it develops an undefined ridge in the line of the
umbonal slope.

Test moderately thick, marked by fine concentric striae which are fascicu-
late on the body of the shell, giving rise to strong undulations. Interior
unknown.

A medium-sized specimen has a length of 28 mm. and a height of 17 mm.
A larger individual measures 30 mm. in length and 18 mm. in height.

504 PALAEONTOLOGY OF NEW YORK.

Compared with E. fabulis, this species has a stronger test, with a greater
proportional height and much stronger surface characters. It is similar in
many respects to E. patula, but is less oblique, umbonal region more prominent,
and the anterior end shorter.

Formation and localities. In the Hamilton shales ; at Hamburgh-on-the-Lake,
Erie county ; Ludlowville, Tompkins county, and Cooperstown, Otsego county,
N. Y.

Elymella levata, n. sp.

Shell of medium size, sub-elliptical, wider behind ; length about twice the great-
est height ; basal margin nearly straight, scarcely sinuate anterior to the mid-
dle, curving regularly to the anterior and posterior ends. Posterior extrem-
ity symmetrically rounded, the greatest extension being below the middle of
the height. Cardinal line straight for less than half the length of the shell,
and curving posteriorly. Anterior end very short, declining abruptly from
the beak and rounded below. Lunule well-defined.

Valves regularly convex on the posterior half, becoming gibbous in the
middle and umbonal region.

Beaks sub-anterior, small, appressed. Umbonal slope prominent, not
strongly defined, becoming merged in the general convexity posterior to the
middle of the shell. The valves are flattened just below the beaks, and a
slight depression continues to the base, producing a gentle sinuosity in the
margin. Post-cardinal slope wide.

Surface marked by fine striae of growth which are more or less fasciculate.
The striae curve over the posterior slope and extend forward along the car-
dinal line nearly parallel with it. The substance of the shell is marked by
distinct radii, which are sometimes obscurely defined upon the surface.

The specimen described has a length of 27 mm. and a height at the pos-
terior extremity of 14 mm., and at the beaks of 10.5 mm.

This species is proportionally more elongate than any other in the genus,
and is also distinguished by the flattening which extends from the beaks to
the base, producing a slight sinuosity in the margin.

LAMELLIBRANCHIATA. 505

Formation and locality. In the shales of the Hamilton group, near Jefferson,
Schoharie county, N. Y.

Elymella patula, n. sp.

PLATE XL, FIG. 11.

In part Modiomorphaf hyalea. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PL 40, tigs.

5-H. 1883.
Not " " " Prelim. Notice Lamellibranchiata, 2, p. 79. 1870.

Shell below the medium size, obliquely sub-ovate, broader anteriorly; length
one-third greater than the height; basal margin gently curved, abruptly
recurving into the anterior and posterior extremities ; posterior margin
abruptly rounded, more gently recurving to the hinge-line ; cardinal margin
nearly straight for about half the length of the shell, then gently curving
toward the posterior end. Anterior end regularly rounded, short, abruptly
curving into the lunule, not limited by any sinus or depression.

Valves depressed-convex in the posterior and lower portion, and more con-
vex in the umbonal region.

Hinge-line straight, about one-half the length of the shell.

Beaks small, sub-anterior, distinct, incurved. Umbonal region moderately
convex, not defined nor continued as a ridge on the posterior slope.

Test thin, marked by fine, sharp, elevated concentric striae, which are
sometimes aggregated into fascicles, giving the surface an undulated charac-
ter. Interior unknown.

The specimen has a length of 32 ram. and a height of 20 mm.

This species resembles E. nuculoides, but differs in the slightly longer and
wider anterior end, less gibbous valves and less prominent umbo ; the posterior
end is also more narrowed toward the extremity.

Formation and locality. In the shales of the Waverly group, at Medina, 0.

506 PALEONTOLOGY OF NEW YORK.

SpHENOTUS (?) UNDATUS.

PLATE LXXX, FIG. 6.

In part SatiffiUrwlitea undatus. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 80, figs.

.'), fi. 1883.

Shell large, elongate-ovate, wider behind ; length more than twice the greatest
height ; basal margin nearly straight, gently curving to the posterior extrem-
ity and more abruptly curving anteriorly. Posterior margin oblique, gently
rounded or sub-truncate. Cardinal line straight, more than half the length
of the shell. Anterior end narrowly rounded.

Valves depressed-convex in the basal and posterior portions, becoming con-
vex and scarcely gibbous in the umbonal region.

Beaks sub-anterior, small, closely appressed, rising very little above the
hinge-line. Umbonal slope obtusely angular, extending to the post-inferior
margin. Post-cardinal slope wide, essentially flat, with a narrow, obscure
fold a little below the hinge-line. Cincture obsolete.

Surface marked by fine concentric striae, which become fasciculate, pro-
ducing regular, strong, rounded folds or undulations, which are stronger on
the middle of the shell and become obsolete in passing the umbonal ridge.
Interior unknown.

The specimen described has a length of 67 mm. and a height of 28 mm.

This species differs from others referred to this genus in the strong concen-
tric undulations and in the absence or obsolescence of a cincture. It is placed
under this genus with some hesitation, since only two specimens have been
observed, and we have no knowledge of its interior characters.

Formation and localities. In the sandstones of the Chemung group at Mans-
field, Pa., and Erwin, Steuben county, N. Y.

LAMELLIBRANCHIATA. 507

Gbammtsia? subnasuta.

PLATE LXIV, FIGS. 5, 6.
Edmondia xtUmasuta, Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 64, figs. 5, 6. 1883.

Shell somewhat below the medium size, narrowly ovate or trapezoidal in out-
line ; length more than one-third greater than the height ; basal margin regu-
larly curving from the post-inferior angle to the middle of the anterior end.
Posterior extremity obliquely sub-truncate. Cardinal line nearly straight,
gently declining posteriorly from the beaks. Anterior end narrowly rounded.

Left valve regularly convex below, becoming gibbous in the middle and
umbonal region.

Beaks at about the anterior third, prominent and rising above the hinge-
line. Umbonal slope not distinctly defined, gibbous and extending to the
post-inferior extremity, producing a sub-nasute extension.

Surface of the cast marked by fine concentric striae, and at the anterior
end there are some remains of concentric ridges which are obscurely visible
in the cast of the body of the shell. Interior unknown.

A specimen of normal proportions has a length of 35 mm. and a height of
20 mm.

This species may be compared with G. glabra, but it is a much narrower
form, with a proportionally longer hinge-line and more pointed and truncate
posterior extremity. The shell is clearly not related to Edmondia, but its
generic relations are more nearly with Grammysia.

Formation and locality. In the coarse sandstone or conglomerate of the
Chemung group, at Portville, N. Y.

508 PALEONTOLOGY OF NEW YORK.

SANGUINOLITES, McCoy. 1844.

SaNGUINOLITES (?) UNDULATUS.

PLATE JjaV, FIGS. 1, 2.

In part Sdmondia utKiuUUa, Hall. Prelim. Notice Lamellibranchiata, 2, p 91. 1870.
" " " " Pal. N. y., vol. V, pt. 1. Plates and Explanations: PI. 64, figs. 1-4.

1883.

Shell small, elliptical ; length more than one-third greater than the height ;
basal margin gently convex. Posterior extremity broadly and regularly
rounded. Cardinal line straight. Anterior end short and regularly rounded
from just below the beaks.

Valves uniformly convex below, gibbous above and in the umbonal region.

Beaks at about the anterior third, but little elevated above the hinge-line.
Umbonal slope not distinguished from the general convex surface of the shell.

Surface marked by fine concentric striae, which are fasciculate, giving ori-
gin to regular concentric undulations, which extend from the anterior end to
the post-cardinal slope. Interior unknown.

Three specimens measure respectively 24, 22 and 21 mm. in length, and
14, 14 and 13 mm. in height.

This species diflfers from the following (S. subtruncatus) in its stronger concen-
tric undulations, more rounded posterior extremity and the absence of an um-
bonal ridge.

Formation and localities. In the sandy shales of the Chemung group, near
Great Valley and East Randolph, Cattaraugus county, N. Y.

SaNGUINOLITES (?) SDBTRDNCATUS, n. sp.
PLATE LXIV, FIOS. 3, 4.

In part Ednumdia undulata. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 64, ligs. 1-4.

1883.

Shell small, sub-elliptical, truncate posteriorly; length more than one-third
greater than the height ; basal margin very gently curving, appearing to be

LAMELLIBRANCHIATA. 509

nearly straight, abruptly recurving at the posterior extremity, which is
almost vertically truncate. Cardinal line straight, scarcely declining poste-
riorly. Anterior end short and abruptly rounded below.

Valves regularly convex below, becoming gibbous in the middle and above.

Beaks near the anterior third, incurved and rising but. little above the
hinge-line. Umbonal slope obtusely angular, extending to the post-inferior
extremity.

Surface marked by fine concentric striae, which become fasciculate and are
elevated into somewhat irregular concentric undulations, which extend from
near the anterior end over the umbonal slope. Interior unknown.

Two specimens measure respectively 24 and 22 mm. in length, and 13 and
Vi mm. in height.

Formation and localities. In the arenaceous shales of the Chemung group, at
Counewango, Cattiiraugus county, and Cherry Creek, Chautauqua county, N. Y.

PROTOMYA, N. G.
Protomya oblonga.

PLATK LXUI, FIG. 21.
Cardiomorpha oblonga. Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations : PI. 63, lig-. 21. 1883.

Shell large, elongate-ovate, narrower behind ; length twice the height ; basal
margin very gently curving. Posterior extremity gaping, regularly rounded.
Cardinal line gently declining posteriorly. Anterior end large, rounded.

Valves moderately and regularly convex.

Beaks a little anterior to the middle of the length, low, not strongly de-
fined, rising but little above the hinge-line. Umbonal slope regularly con-
vex, not defined.

Surface, in the cast, marked by fine concentric striae, which are aggregated
into fascicles, producing low undulations of the surface.

Anterior muscular impression strongly marked, situated just within the
65

510 PALEONTOLOGY OF NEW YORK.

anterior border of the shell. Posterior scar large, round, situated on the
post-cardinal slope.

The two specimens observed measure respectively 67 and 72 mm. in
length, and 32 and 36 mm. in height.

The species is represented by two specimens, both occurring in the Hamilton
group, and it is so distinct from any other form as to preclude comparisons.
Its general form and aspect is somewhat similar to some forms of Panop^a.

Formation and locality. In the sandy shales of the Hamilton group, at Ful-
tonham, Schoharie county, N. Y., associated with Leiopteria Bigsbyi, Goniophora
Hamiltomnsis and Rhynchonella congregata.

PROMACRUS, Meek. 1871.
Promacrus cuneatds.

PLATE LXXVni, FIG. 28.

Pholadella enneata. Hall. Prelim. Notice Lamellibranchiata, 2, p. 66. 1870.

" decussate, " Pal. N. Y. vol. v, pt. 1. Plates and Explaiiation.s : PI. 78, fig. 28. 1883.

Shell below the medium size, elongate, attenuate, sub-cuneate anterior to the
beak.

The specimen is a fragment, preserving the anterior end and the beak. It
proves, upon comparison with Promacrus Missouriensis, to belong to the same
genus. It is distinguished by its smaller size, stronger and more regular con-
centric undulations, and distinct continuous radii of the surface, which become
nodose at their intersections with the concentric undulations.

The specimen, anterior to the beak, has a length of 45 mm. and a height at
the beak of 24 mm.

Formation and locality. In the Yellow sandstones, at Burlington, la.

LAMELLIBRANCHIATA. 511

CYTHERODON, Hall. 1873.
Cytherodon nasutus.

PLATE LXXV, FIGS. 10-12 ; AND PLATE XCV, FIG. 30.

CythenxUm , H.ali,. Twenty-third Ann. Reji. N. Y. State Cal). Nat. Hist. Kx. jil., pi. 14, fig-. 21. 1872.

" {Sehiz<>dus)nasittus,ll\Lh. Pal. N. y.,v'ol. v, pt. 1. Plates and Explanations : PI. 75, figs. 10-12.

18S3.

Shell large, obliquely ovate or sub-rhomboid al ; length a little greater than the
height. Basal margin broadly rounded in the middle and anterior portion,
constricted near the post-inferior extremity, which is sub-nasute and abruptly
rounded. Posterior margin obliquely sub-truncate. Cardinal line arcuate,
declining posteriorly. Anterior end short, sloping very rapidly from the
beaks and rounded below.

Valves convex in the lower and posterior portions, becoming gibbous in
the middle and umbonal region.

Beaks at about the anterior fourth, small, attenuate, rising above the hinge-
line. Umbonal slope defined by a flattening of the valve or shallow furrow
extending from the beaks to the sinus in the basal margin. Post-cardinal
slope moderately convex, with the margin abruptly descending from the
umbonal slope to the cardinal line.

Test thick. Surface marked by fine concentric striae which are sometimes
aggregated into fascicles.

Muscular scars distinct. Inter-pallial area in the cast marked by numer-
ous, very small pustules. Hinge thickened, encroaching upon the cavity of
the beaks, which is excavate in the cast of the interior. Cardinal teeth inter-
locking, situated beneath and anterior to the beaks. There are apparently
four cardinal teeth in the right valve and five in the left.

The specimen described is a cast of the interior, and imperfect along the
basal margin. When entire it has measured about 53 mm. in length and
about 50 mm. in height.

In its general form this fossil somewhat resembles several species of Schizodus,

512 PALEONTOLOGY OF NEW YORK.

but the chanicters of the hinge are very distinctive, and there is no defined
unibonal ridge extending to the post-inferior extremity.

Formation and locality. In the shales of the Hamilton group, in Hardy
county, Va.

CLINOPISTHA, Mkek and Worthen. 1870.

Clinopistha subnasuta.

PLATE LI, FIGS. 32,83; AMD PLATE XCV, FIG. 81.

Tdlinomya [Dystactella] svbtuisiita. Halt, and Whitkibld. Twenty-fourth Ann. Rep. N. Y. State Mus.

Nat. Hist., .p. 191. 1872.
Dyxtactella siibnaimta (Hall and Whitkield), S. A. Millbh. Cat. Am. Pal. Foss., p. 190. 1877.

" " " " Hall. Pal. N. Y., vol. v, pt. 1. Plates and ExplanationB :

PI. 51, figs. 32, 33. 1883.

Shell small, narrowly sub-elliptical, nearly straight on the basal side ; length
about twice the height. Basal margin nearly straight, curving abruptly to
the anterior and more gently to the posterior end. Posterior extremity
rounded. Cardinal line gently arcuate. Anterior end short, sub-nasute,
declining from the beaks and narrowly rounded below. The place of the
lunule is occupied by a fold or callosity which is distinctly limited by the
margins of the valve.

Valves moderately convex below and posteriorly, gibbous in the umbonal
region.

Beaks at about the anterior third, small, closely appressed. Umbonla
slope convex, not defined.

Test thin. Surface marked by somewhat regular, fine, thread-like strige
of growth, which in the perfect condition of the shell may have been lamel-
lose, and are fasciculate on some individuals.

The hinge shows some appearance of having been crenulated, but the con-
dition of the specimens is such as not to admit of positive determination.
Muscular impressions distinct. Pallial line entire, marked in the cast by a
series of radiating pustules.

Three specimens measure respectively 21, 26 and 27 mm. in length, and
12, 13 and 13 mm. in height.

LAMELLIBRANCHIATA. 6l3

This species bears some general resemblance to the fossil referred to Solemya
vetusta, especially in the fold of the shell on the upper anterior margin, and it
may prove congeneric with that form.

Formation and locality. In the cherty layers above the Hydraulic limestone,
near Louisville, Ky.

Clinopistha tellinifokmis.

PLATE M, FIGS. 28-31.
Dystactella teUiniformis, U.KU.. Pal. N. Y., vol. v, pt. 1. Plates ami Explanations : PI. 51, figs. 28-31. 1888.

Shell large, obovate ; length less than twice the height. Basal margin gently
curved, nearly straight anterior to the middle. Posterior end large and
rounded. Cardinal line arcuate. Anterior end produced, nasute, obliquely
truncate above.

Valves gibbous in the middle and umbonal region.

Beaks behind the anterior third, not prominent. Umbonal slope rounded,
not defined. Umbo flattened in the middle and the flattening continued
vertically to the base. On the anterior end there is a distinct angular ridge
on each valve, extending from the beaks to the antero-inferior extremity.

Surface marked by fine striae of growth very obscurely preserved in the
specimens described, which are casts of the interior. Interior unknown.

A large specimen has a length of 65 mm. and a height of about 38 mm.
An imperfect specimen has a height of 35 mm., a length anterior to the beaks
of 30 mm., and the depth of both valves is 26 mm. A small individual
measures 38 mm. in length, 20 mm. in height, and the depth of both valves
is 18 mm.

This shell is much larger than the preceding species, the anterior end is more
produced, and the valves are more gibbous.

Formation and locality. In the limestone of the Upper Helderberg group,
Cayuga, Ontario.

514 PALEONTOLOGY OF NEW YORK.

MOD I ELL A, Hall. 1883.

MODIELLA PYGM^A.

PLATE LXXVI, FIGS 9-20.

Ptfrinea pygiiuea, Conrad. Jour. Acad. Nat. Sci., Phila., vol. viii, p. 2.')1, pi. 13, fig. 15. 1842.
Cjfpricardinia pyffiiuta (Co.nkad), S. A. Millkr. Cat. Am. Pal. Fosa., p. 188. 1877.

MitdieUa jrj/iriium (Conrad), Hall. Pal. N. Y., vol. v, pt. 1. Plates and Explanations: PI. 76, figs. 9-20.

1883.

Shell small, obliquely ol)Ovate; length one-third greater than the height.
Basal margin arcuate anterior to the middle, broadly and distinctly curving
to the post-inferior extremity. Posterior margin obliquely and broadly
curved. Cardinal line distinctly arcuate, reaching beyond the middle of the
length of the shell. Anterior end short, auriculate, limited by a depression
extending from just anterior to the beak to the basal margin and producing
a more or less distinct sinus.

Valves very convex in the middle and upper portions of the shell.

Beak^: sub-.anterior, small, closely appressed and incurved. Umbonal
slope not distinctly limited, rather prominent, arcuate, extending to the post-
inferior extremity. Along the middle of the cardinal slope there is some-
times a depression extending to the posterior margin.

Surface marked by fine concentric striae, crossed by curving, radiating
striae which are more distinct on the body of the shell just posterior to the
sinus. In well-preserved specimens the junctions of the radii with the con-
centric striae are elevated into minute pustules.

Mu.scular impressions and pallial line distinctly marked. Hinge-line with
a narrow groove posterior to the beaks.

Three specimens measure respectively 10, 14 and 15 mm. in length, and
7, 9.0 and 10 mm. in height.

The shell has the general form and external characters of a Modiola, with a
constriction on the antero-basal margin indicating the place of a byssal sinus.

Formation and localities. In the shales of the Hamilton group at Pratt's falls,
Onondaga county, and on the shores of Skaneateles, Otisco and Cayuga
lakes, N. Y.

LAMELLIBRANCHIATA. 515

MEGAMBONIA, Hall. 1859.
Megambonia cardiiformis.

PLATE I.II, FIGS. 1-8.

Pterinea cardiiformis. Hall. Geol. Rep. Fourth Dist. N. Y., p. 172, fig. 1. 1843.
Megamhiiiiia cardiifomiis. Hall. Twelfth Ann. Rep. N. Y. State Cab. Nat. Hist., p. 13. 1859.

Pal. N. Y., vol. iii, p. 272. 1859.

" subcardiformis, " S. A. Miller.* Cat. Am. Pal. Foss., p. 194. 1877.

" " " Pal. N. Y., vol. V, pt. 1. Plates and Explanations :* PI. 52, figs. 1-8. 1883

Shell large, cardiiform, higher than long ; basal margin regularly rounded ;
posterior margin curving abruptly upward to the cardinal line ; cardinal
margin sub-alate posteriorly. Anterior end short, auriculate, separated from
the body of the shell by a distinct byssal sinus, which is conspicuously
marked in the margin of the shell.

Valves regularly convex, very gibbous in the umbonal region ; the depth
of the two valves is somewhat less than the length of the shell.

Beaks sub-anterior, incurved ; umbo prominent, rising above the hinge-line.

Test thick, marked by concentric lamellse of growth and by fine radiating
striae.

Anterior muscular impression large and deep, situated within the auricle
and occupying a large part of the lobe. Posterior muscular impression large,
situated near the post-cardinal extremity. There is an obscure indication
of a lateral tooth on the post-cardinal angle.

A large and nearly perfect specimen has a length of 59 mm. and a height
of 73 mm., with a depth to both valves of 46 mm. A larger specimen has
a height of 76 mm. and a transverse diameter of 64 mm.

This species somewhat resembles M. belUstriata of the Oriskany sandstone,
but differs in its greater gibbosity, shorter and more oblique sinus, separating
the auricle.

Formation and locality. In the upper member of the Corniferous limestone
at Clarence Hollow, Erie county, N. Y.

• The reference of this species under the specific name of subcardi/ormis has come from copying an
erroneous manuscript record of the species.

516 PALAEONTOLOGY OP NEW YORK.

AMNIGENIA, Hall. 1883.
Amnigenia Catskillensis.

PI.ATK XL, FIGS. 1-4; AND PLATE LXXX, KIU. 12.

Cyprlcarditm CaUkVlensiK Vanixkm. Geol. Surv. N. Y., Rep. Third Dist., p. 186. t. .52, fig. 1. 1S42.

Modiinnorphn " " S. A. Millkk. Cat. Am. PaL Fobs., p. 196. 1877.

Amnigenia " " Hali,. Pal. N. Y , voL v, pt. 1. Plates and Explanations : PI. 40,

figs. 1-4 ; PI. 80, fig. 12. 18S3.
Cyjiricarditm augiuifnta, Vanisskm. Geol. Surv. N. Y., Rop. Thii-d Dist., p. 186, t. .52, fig. 2. 1842.
^ofVumutrpha " " S. A. Millkk. Cat. Am. Pal. Foss., p. 196. 1877.

Modiola angusta (Co.nrad, in eiror), Dana. Manual of (leology, p. 292, fig. 508. 1863.

Shell large, elongate-sub-elliptical or narrowly obovate, somewhat arcuate ;
length more than twice the height ; basal margin often nearly straight, usu-
ally gently sinuate at about the anterior third and convex on the posterior
half, sometimes gently convex for the entire length. Posterior extremity
rounded, obliquely sub-truncate above from the extremity of the cardinal
line. Cardinal line gently arcuate, rising from the beaks to beyond the mid-
dle of the shell, with a slight alation. Anterior end short, rounded.

Valves depressed-convex posteriorly, becoming convex in the middle and
in the umbonal region.

Beaks sub-anterior, low, appressed, rising but little above the hinge-line.
Umbonal slope convex, undefined, extending to the middle of the posterior
extremity. Post-cardinal slope wide, not defined.

Surface marked by fine concentric striae, which are often strongly fascicu-
late on the posterior, basal and anterior portions.

Anterior muscular impression large, strong, situated just anterior to the
beaks and clo.se beneath the upper margin of the shell. The left valve shows
a double fold along the cardinal margin Ix'hind tiie beaks.

Three specimens measure respectively 105, 109 and 112 mm. in length,
40, 39 and 43 mm. in height at the beaks, and 47, 47 and 50 mm. in height
at the posterior third. A large specimen has a length of 155 mm. and a
height of 67 mm. A compressed specimen of the form described and
figured by Vancxem as Cypricardites angustata, measures 104 mm. in lengtli

AuoDST, 1885.

LAMELLIBRANCHIATA. 517

24 mm. in height at the beaks, and 27 mm. in height near the posterior
extremity. The various phases of this species seem to be all due to the
degree and direction of pressure during the process of imbedding.

Formation and localities. In the Oneonta sandstone, at Mt. Upton, Chenango
county ; Gilbertsville, Otsego county ; on the road from Jefferson to Gilboa,
and at the base of the hills to the south of Jefferson, Schoharie county, N. Y.
Prof. J. J. Stevenson has found a single valve of this fossil in the Catskill red
sandstone on Wills creek, about one mile from Hyndman, and 1,600 feet above
the base of the formation, in Bedford county, Pennsylvania. (Report T. 2, p. 103.)

This species is the only mollusk known in the Oneonta sandstone. At Mt.
Upton it occurs in a shaly stratum associated with numerous plant remains.
The bed containing the specimens of this species in great abundance is sur-
mounted by at least five hundred feet of shales, altern<ating with bands of
gray and reddish sandstones, containing great numbers of plant remains which
have not been identified.

The relations of the Oneonta sandstone to the Hamilton and Chemung
groups has heretofore been discussed,* and all subsequent studies of the locali-
ties in Delaware, Otsego and Chenango counties sustain the views published by
me in 1870 and 1880. This deposit, consisting of red and gray compact or
shaly sandstones, red and green marls, etc., comes in at about the close of the
Hamilton period, or more properly may be regarded as the result of changes
which terminated the conditions of the Hamilton group. The changes super-
vening in the east, at that time, seem to have affected the succeeding strata
throughout the entire length of the State, although this particular portion of
the series apparently merges into the succeeding Portage group, of which, farther
west, it forms a part. The presence of numerous fragmentary and drifted land
plants indicates the proximity of land, and in Schoharie county, just below
the commencement of the red deposits, we find the trunks of two species of
Psaronius, stsmding erect in the place and position in which they have grown,
enveloped by an argillaceous sandstone with their bases resting upon and imbed-

* 8«e Report upon the State Museum for 1870, and a paper i-ead before the National Aca<lemy of Sciences
in New York, 1880, of which an abstract was published in "Science," December 11, 1880.

66

518 PALEONTOLOGY OF NEW YORK.

ded in the underclay, showing that the ocean bed had been elevated above the
sea level for a considerable period of time. This horizon is probably the
equivalent of the lower part of the Oneonta series, and may be regarded as
of Hamilton age. The influx of these shore deposits into an area occupied by
marine sediments and a marine fauna has, for a considerable extent westward,
and through a considerable time, broken the continuance of the marine fauna,
though gradually mingling with the succeeding marine deposits in its western
extension.

The Oneonta sandstone in Otsego and Chenango counties, is succeeded directly
by strata bearing fossils of Chemung age, leaving no question as to its relations.
All the more recent investigations serve to show that the views heretofore ex-
pressed regarding the position and relations of this formation are correct, and
that properly it forms no part of the Catskill group, except so far as it is the
result of similar conditions which were intermitted at the close of the Oneonta
and resumed after the deposition of the Chemung sediments, and which may
have once been continuous in some far easterly locality. Moreover, with our
present knowledge, the higher beds of the Chemung, as known in the central
and western portions of the State, have no considerable extension to the east-
ward. The fossils obtained on the western flank of the Catskill mountains are
comparable with those of the middle portion of the group as developed in
central New York. Thus far I am not aware that the Chemung group has
been positively shown to exist on the eastern flank of the Catskills, and
the rapid thinning of that formation to the eastward, as shown on the geological
map, suggests the possibility of it having thinned out entirely before reaching
the Hudson river valley.

Catskill group,
Chemung group.

Portage group,

' Hamilton (Upper),
Hamilton group,
Corniferous limestone,
Oriskany sandstone.

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PALEONTOLOGY OF NEW YORK.

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IV, tigs. 1, 2.

I. tig. 5.

IV, tigs. 3-8 ; LXXXII, fig. 3.

II. figs. 1-4 ; LXXXII, fig. 5.
IV. tig. 9 ; VIII, figs. 9, 10.
XXIV, tig. 8.

IV, tig. 11 ; VII, fig. 26 ; X, figs. 6-12.

VII. fig. 25.

VIII. tig. 8.

IV, tig. 10 ; X, fig. 5 ; LXXXII, fig. 2.
X, tigs. 1, 2 ; LXXXII, fig. 6.

IX. figs 10, 11.
XXIV, fig. f,.

I, figs. 6. 7.

LXXXII. fig. 8.

1. fig. 4.

LXXXII. fig. 13.

I, tigs. 16, 17 ; LXXXm, figs. 6, 7.

1, tigs. 12, 14, 15.

I, tig. 13.
XVn, tigs. 13-15.

xvn, tig. 16.

XVII. tigs 17, 18, 20, 21.

XVII, tig. 22 ; LXXXII, figs. 9. 10.

XVII. tig. 19 ; LXXXIII, figs. 4, 5.

LXXXIII, fig. 1.

V, figs. )-S ; LXXXIII. tigs. 2, 3.

II. figs. 10-19 ; LXXXII, fig. 7.
XXIV, tig. 2; LXXXII, fig. 18.
XXIV, fig. 1.

LXXXII, figs. 11, 12.
LXXXII, figs. 15-17.

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yriopecten. Hall. 1
parallelodoiitu.s. Hall,
Dardaniis, Hall,
orbiculatus. Hall, .
interrailiatus. Hall,
inacrodontus. Hall, .
cynibalon. Hall,
tricostatus, Vanuxem
Polytlonis, Hall,
raagiiiticus. Hall, .
anoinia'formis. Hall.
Priamus. Hall,
fa.sciatus. Hall, .
solox. Hall, .

Pterinopecten, Hall
P. multiradiatus. Hall,
P. reflexus, Hall, .
P. insons. Hall, .
P. nodosus. Hall, .
P. exfoliatus. Hall, .
P. dignatus. Hall, .
P. la'tus. Hall. .
P. Hermes. Hall. .
P. spondylus. Hall,
P. con.spectns. Hall,
P. tilitextu.s. Hall.
P. interinedius. Hall.
P. i-egularis. Hall,
P. Vertumnu.s, Hall,
P. undosus. Hall.
P. (Aviculopecten ?) stii
P. imbecili.", Hall,
P. dispantlus. Hall,
P. erectus. Hall,

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VIII, tigs. 3, 4 ; LXXXII, fig. 14.

VIII, tigs 5-7.

VIII, tigs. 1,2; XXIV, tig. 10 ; LXXXII, fig. 4.

IX, tigs. 9, 13, 18.

IX, figs. 6, 7, 8, IB, 16, 17.

IX, fig. 14 ; LXXXIII, fig. 10.

IX, tigs. 19, 21.

IX, figs. 20, 22 '(

IX, fig. 23.

IX fig. 24 ; LXXXIII, fig. 9.

IX, tig 12 ; LXXXIII, fig. 8.

IX, figs. 1, 2, 4, 25-30.

LXXXIII, fig. 14.

XV, tigs. 2, 3 ; LXXXIII, flg. 13.

XIV. tigs. 1-21; XV, figs. 1, 4-6, 8-10;
LXXXIII, fig.s. 11, 12.

LXXXIV. fig. 22.

XV. fig. 7.

XVI. figs. 3, 7, 10, 12 ; LXXXIV, flg. 21.
XVI, figs. 1, 2, S, 9, 11 ; LXXXIV, fig. 23.,
XVI, figs 5, 6.

XVI, figs. 4, 13, 14.

XXIV, figs. 6, 12 ; LXXXIV, fig. 24.
XXIV, figs. 9, 11, 13.
LXXXII, figs. 19, 20.

XXV, fig. 1.
XVII, figs. 1-3.
XVIL fig. 4.

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P. crenicoBtatus. Hall, .

P. Neptunus, Hall

P. suborbicularis. Hall, .

Creulpecten, Hall. 1883.

C. ampins. Hall.. ....

C. crenulatus. Hall,

C. iinpolitus. Hall, ....

C. obsoletns. Hall, ....

C. glaber. Hall

C. niicropterus. Hall,

C. liratus. Hall,

C. Leon, Hall. ....
C. Winclielli, Meek

Pteriaea, Gokifuss. 1826.
P. grandis, n. sp., ....
P. pinguis, Hal .....
P. fiabella, Conrad

P. intei-strialis, Hall, ....
P. dispanda. Hall, ....
P. Cheniungensis, Conrad,
P. consimilis. Hall,

P. Hgida, Hall

P. prora. Hall, ....

s. g. VERTUMNIA, Hall. 1883.

P. (Vertumnia) revers<a. Hall, .

P. (Vertumnia) avis. Hall,

P. (Vertumnia) reproba. Hall, .

Actinopteria, Hall. 1883.

A. eximia. Hall,

A. muricata. Hall, ....
A. Doris, Hall,

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PALEONTOLOGY OF NEW YORK.

i
§

XVn. figs. 23, 2.%27, 29-31 ; XIX, fig. 25.
XVn. figs. 24. 28 ; XVIH. figs. 1-15 " XX. fig.

19; LXXXIV. fig. 4.
XIX. figs. 2-24. 26-HO ; LXXXIV, figs. 16, 17.
XIX. tig. 31 ; LXXXIV, fig. 14.
LXXXIV, fig 3.

XXIII, figs. 2, 7 ; LXXXIV, fig. 12.
LXXXIV. figs. 5, 6.
LXXXIV. fig 15.
XXXIII. fig. 3.
XXIII. figs. 4 (f,. 6 ?). 8.
XXIII. fig. 9 ; LXXXIV, figs. 1, 2.
LXXXIV. figs. 8-11
LXXXIV. figs. 18, 19.
LXXXIV, fig. 7.
LXXXIV, fig. 13.

XXIIL figs. 12. 14.

XXIII, fig. 13 ; LXXXV, fig. 8.

XXIII. figs. 17-20.

XXIII, figs. 16. 23 ; LXXXV, figs. 14-18.

XXIII. fig. 24 ; LXXXV, figs. 27, 28.

LXXXV. figs. 1^.

LXXXV. figs. 6, 7.

LXXXV. fig. 19.

LXXXV, fig. 9.

XXIII. figs. 25. 26 (21,22?); LXXXV, %.

26.
LXXXV, figs. 34, 35.
LXXXV. tigs. 10-13.
LXXXV, figs. 29-31.
LXXXV. figs. 21, 22.
LXXXV. fig. 20.
LXXXV, figs. 23-25.
LXXXV, figs. 38. 39.
LXXXV. figs. 32, 33.
LXXXV, fig. 5.
LXXXV, fig. 37.

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A. subdecussata. Hall

A. Boydi, Coni-ad.
A. perobliqua, Conrac
A. pusilla. Hall. .
A. perstrialis, Hall.
A. tenuistriata. Hall,
A. auriculata. Hall,
A. delta. Hall. .
A. epsiloi). Hall,
A. zeta. Hall, .
A. eta. Hall. .
A. thota. Hall, .
A. iota. Hall. .
A. kappa. Hall, .

Ptychopteria, Hal

P. Proto. Hall, .
P. sinuosa. Hall.
P. Salamanca. Hall,
P. Sao. Hall. .
P. Eucrate. Hall.
P. 'fhetis. Hall. .
P. fal.^ata. Hall. .
P. Spio, Hall. .
P. Eudora. Hall,
P. alata. Hall,

P. tngonalis, Hall,
P. eloiigata. Hall, .
P. Galene. Hall. .
P. Beechen. Hall, .
P. spatulata. Hall,
P. lata. Hall. .
P. perlata. Hall.
P. Thalia. Hall. .
P. gibbosa. Hall,
P. lobata. Hall,

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LAMELLIBRANCHIA TA.

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LXXXV, fig. 36.
XXIII, figs. 10, 11.

XI, figs. 1-10; XII, figs. 1-3, .5-9; XIII, figs.
1-4. 12-15; XXV, figs. 14-17 ; LXXXVI, figs.
1-S ; LXXXVII, figs. 1-3.

XII, fig. 4; Xin. figs. 5-11.
XV, fig. 12 ; LXXXVI, fig. 9.

XVII, figs .5-11 ; XX. fig. .5.

XX. figs. 1, 2, 4 ; LXXXVIII, figs. 1-4.

XX. figs. 9, 12 ; LXXXVIII. figs. 21, 22.

XV. fig. 1 1 ; XX. figs.6.7; LXXXVIII, figs. 27,28.

LXXXVIII, figs. 15-20.

XIX, fig. 1 ; XX, figs. 16-18; LXXXVIII, figs.
5-10.

XX, figs. 3, 11. 13-15 ; LXXXVIII. fig. 23.
XX, fiir. s ; LXXXVIII, fig. 26.
LXXXVIII, figs. 12. 13.

LXXXVIII. figs. 24, 25.

LXXXVIIL fig. 14.

XX. fig. 10.

XXn. fiffs. 17, 18.

LXXXVIII, fig. 29.

XXII, figs. 6, 7 ; LXXXVIII, fig. 11.

xvn. fig. 12.

XXI. figs. 1-9.

XXI. figs. 10-13 ; LXXXIX, fig. 1.

XXI, fitfs 14, 17-19 ; LXXXIX, figs. 2-4.

LXXXIX. figs. 5, 6.

XXI, figs. 15. 16, 20 ; LXXXIX, fig. 8.

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P. Vanuxemi. Hall, ....
P. expansa. Hall

Glyptodcsma, Hall. 1883.

G. erect iini, Conrad, ....

G. erectuni. var. obliquum. Hall,
G. oecidentale. Hall,

Lelopteria, Hall. 1877.

L. laevis. Hall

L Conradi, Hall, ....

L. Greeni. Hall

L. Rafine.s(|iiii, Hall,

L. Savi. Hall

L. De Kayi, Hall, ....

L. Bigsbvi. Hall

L. Mitehelli, Hall

L. Troosti, Hall

L Leai. Hall

L. Gabbi. Hall

L. Oweni. Hall, ....

L. Chemungensis. Vannxem,

L. linguiformis. Hall,

L. Torreyi, Hall

Leptodesina, Hall. 1883.

a, spinifera.

L. Marcellense, Hall

L Rogerai, Hall

L. spinigerum, Conrad,

L. longispinum. Hall,

L. Shumardi, Hall, ....

L. robustum, Hall, ....

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524

PALJEONTOLOGY OF NEW YORK.

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525

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XXII, fig. 28; XCI, fig. 2.
XXV, fig. 12 ; XCI, fig. 3.
XCI, fig. 1.
XCI, fig. 7.
XCI, fig. 8.

XCI, tig. 9.
XCL figs. 10, U.
XXII, tig. 2.

XXV, tigs. 8. 13 ; XCI, figs. 13, 14.
XCI, fig. 12.
XCI, tig. 18.
XCI, tigs. 16, 17.

XXI, tigs. 35-39 ; XCI, figs. 19, 20.
XCI, tig. 15.

XCI. fig. 21.

XXV, figs 7, 11 ; XCI, tigs. 22-25.

XXIL tigs. 25-27.

XXII, tig. 24.
LXXXVII, fig. 5.

XXV, tig. 18 ; LXXXVII, tig. 4.
XXV, fig. 19.

XXIII, figs. 27-30 ; LXXXIV, fig. 20.

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L. aliforme. Hall, ....

L. rude. Hall

L. Biton, Hall,

L. Lesleyi, Hall

L. aviforme. Hall, ....

d, patulata.

L. flaccidum. Hall

L. patulum. Hall

L. complanatum. Hall, . . ,

e, arcoidea.

L. Maclurii, Hall, ....
L. arciforme. Hall, ....

L. Phaon, Hall

L. propinquum. Hall,

L. Lichas, Hall,

L. quadratum, Hall,

/, mytiloidea.

L. acutirostrum. Hall,
L. mytilifoi-me. Hall,

Pteronites, McCoy. 1844.
P. profundus. Hall, ....
P. rostratus, Hall, ....
P. inoptatus. Hall

Palseopiuua, Hall. 1883.

P. flabella. Hall, . Oriskany Sand. .

P. recurva. Hall, ....

Ectenodesina, Hall. 1883.

E. birostratum. Hall

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529

•o

S
1

XLVIL figs. 1-12.

XLVII, tigs. 13-16.

XLVII, figs 17-28 ; XCIII, figs. 8-10.

XLVII, tigs. 29, 30.

XLVIL figs. 31-37.
XLVII, figs. 38-41.
XLVII, figs. 42-47.
XLVII, tig. 48.
XLVIL figs. 49, 50.

XLVIIL figs. 1-16 ; LL fig. 17.

XLVIII, figs. 17-20.

XLVIU, figs. 21-28.

XLVIII, figs. 29-38.

XLIX, figs. 1-12, 14 ; XCIII,;fig. 18,

XLIX, figs. 13, 15-24.

XLIX, figs. 25-i52.

L, figs. l-Il.

L, figs. 15-22 ; XCIII, fig. 12.

XCIII, fig. 14.

L, fig. 23.

L, figs. ^4-33.

XLIX, figs. 33-38.

XCIII, fig. 11.

L, figs. 12-14.

XLVIII, fig. 39 ; XCIII, fig. 11a.

L, figs. 34-39.

L, figs. 40,41.

L, figs. 42-46.

XCIII, fig. 15.

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N. obloiigatus, Conrad,
N. cuneiforrais, Conrad,
N. ti-iqueter, Conrad, .
N. Nyssa, Hall, .

Leda, Schumacher. 1817.

L. divei-sa. Hall,

L. brevii'ostris. Hall,

L. rostellata, Conrad,

L. obscura, n. sp., .

L. pandoiiformis, Stevens,

Palaeoneilo, Hall. 1870

P. constricta, Conrad,

P. c^nstricta, var. flexuosa,

P. plana. Hall, .

P. maxima, Conrad,

P. tenuistriata. Hall, .

P. fecunda. Hall, .

P. muta. Hall, .

P. emarginata, Conrad, .

P. perplana. Hall,

P. Virginica, n. sp.,

P. ai-ata. Hall, .

P. brevis. Hall,

P. filosa, Conrad,

P. angusta, n. sp., .

P. bisulcata. Hall,

P. eloiigata, Hall, .

P. attenuata. Hall, .

P. truncata. Hall, .

P. sulcatina, Conrad, .

P. ? dubia, n. sp., .

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630

PALEONTOLOGY OF NEW YORK.

1
1

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LI, figs. 22-27.
XLI, fig. 27.
XCIIL figs. 17, 18

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LIII, figs. 21-26.
LIII, tigs. 1-6.
XXXIV, tig. 8.

XCIII, fig. 22.

LIV, figs. 1-16 ; LVI, fig. 1 ; XCIlI,lfig. 25.

LV, figs. 1-1 1 ; LVI, figs. (2, 8 ?) ; LVII, figs

7. 8 ; XCVI, figs. 19-21.
LVI, figs. 4-7 ; LVII, fig. 9.
LVL fig. 8 ; LVIL fig. 10.
LVII, figs. 3-6 ; LVIII, fig. 13.
LVIII, figs. 1-12, (1, 5, 6?).\

LIX, figs. 21-27.
LXIII, 1-3.
LXIII, figs. 7, 8.
XCIII, tig. 24.

LVII, figs. 1, 2 ; LX, figs. 1-11.
LIX. figs. 6-12.
LXII. figs. 10-19.

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Gramniysia, De Verneuil. 1847.

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c. undnlata.

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LAMELLIBRANCHIA TA.

531

1

LXIII, figs. 4, 5.

LXI, figs. 1-9 ; LXIII, fig. 6 ? ; XCIII, fig. 27.

LXI, figs. 10-22 ; XCIII, fig. 26.

LIX, fig. 1.

LIX, figs. 2, 3.

LIX. figs. 13-20, (4, 51) ; LXXVIII, figs. 26, 27.

LXI, figs. 24-28 ; XCIII, fig. 20.

LXI, fig. 23 ; LXIV, fig. 30 ; XCIII, fig. 21.

XCIII, tig. 23.

LXI. tigs. 29. 30, 33.

LXI, figs. 31, 32.

LXII. tigs. 1-9 ; XCIII, fig. 19.

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LXIV. figs. 9, 11-14, 17, 29 ; XCV, figs. 1-4.
LXIV, tigs. 15, 23, (16?) ; XCV, tigs. 5-8.
LXIV, figs. 18, 19, 20, 26, 27, 28, (10, 21 1) ; XCV,

figs. 9-12.
LXIV, fig. 24.

LXIV, fig. 52 ; XCV, figs. 13, 14.

LXIV, fig. 32.

LXIV, fig 25.

LXIII, tigs. 9, 10 ; XCV, fig. 17.

Explanation of PL LXIV, tig. 31.

LXV, figs. 1, 4-6.

LXV, figs. 7-11 ; LXVI, fig. 431

LXV, tigs. 12-17.

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533

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a
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LXIX, fig. 5 J XCIV, fig. 18.

LXIX. figs. 1, 2.

LXIX, tig. 3.

LXIX, tigs. 4, (7 ?) ; XCIV, fig. 17.

XCIV, fig. 15.

LXIX. tigs. 12-14.

LXXX, tigs. 8, (9?).

LXIX. fig. 6.

LXIX, figs. 8, 10.

LXIX, tig. 9.

LXIX. fig. 11 : XCIV, fig. 16.

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LXX. figs. 22-24.

Not figured.

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PALEONTOLOGY OF NEW YORK.

1

1

X

LXXI. figs. 1-14.
LXXI, figs. 15, 16.
LXXI, fig. 17.
LXXI, fig 24.
LXXL figs. 18-23.
LXXI. figs. 25-32.
XCIV, figs. 24, 25.

LXXII. figs. 23-33 ; XCV, fig. 18.

LXXn, figs. 2-19 ; XCV, fig. 19.

LXXII, fig. 1 ; XCV, fig 24.

LXXII, figs. 20-22 ; XCV, fig. 25.

XCV, fig. 23.

LXXII, fig. 34.

LXin, figs. 18, 19 ; XCV, fig. 21.

XCV, fig. 22.

LXXV, figs. 24-26; XCV, fig. 20.

LXXII, figs. 35-41.

LXXV, figs. 1, 2.

LXXV, figs. 3-9.

LXXV, figs 13-1.5.

LXXV, figs. 27, 28.

LXXV, figs. 16-18 ; XCV, fig. 27.

LXXV, figs. 19-23.

LXXV, figs. 37-40,45,41?

LXXV, figs. 31-34, 36.
LXXV, figs. 43, 44.
LXIIL fig. 17.
LXIII, fig. 20.

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C. radiata. Meek and Worthen, .

Lunulicardium, Munster. 1840.

L. fragile. Hall

L. Marcellense, Vanuxem,

L. ru.le. Hall

L. orbiculai-e, n. sp.,

L. curtum. Hall

L. omatum. Hall, ....
L. transversum, n. sp

Paracycias, Hall. 1843.

P. elliptica. Hall, ....

P. lirata, Conrad, ....

P. Ohioensis, Meek

P. tenuis. Hall, ....
P. Chemungensis, n. sp., T

P. ignota. Hall

P rotunda. Hall

P. erecta, n. sp

P. I pauper. Hall

Scllizodus, King. 1844.

8. % fis.sa. Hall,

8. tumidus. Hall, ....

8. appressus, Conrad,

8. ellipticus. Hall, ....

8. contractus, n. sp

8. gregarius. Hall, ....
8. rhombeus. Hall, ....
8. Chemungensis, Conrad,
8. Chemungensis, var. quadrangula-

ris. Hall

8. oblatus. Hall,

S. degener, n. sp., ....
8. patulus, n. sp., ....

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LXXVI, figs. 2-8.
XCIV, fig. 7.
XCIV, fig. 9.

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LXXVII, figs. 5-8.
LXXVII, figs. 9-14, 16.
LXXVII, fig. 15.

LXXVIII, figs. 15-21 ; XCVI, fig. 1.
LXXVIII, figs 22-24.
LXXVin, fig. 25.

LXXVIII, figs. 1-4.
LXXVIII, figs. 5-9.
LXXVIII, tigs. 10-13.
LXXVIII, fig. 14.

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PALEONTOLOGY OF NEW YORK.

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LXXVIII, figs. 37-42.

LXXVIII, figs. 34, 35.

LXXVIII, fig. 36.

LXXX. tig. 6.

LXV, tigs. 2, 3 ; LXXVIII, figs. 39-88,

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LXXIX, tigs. 1-5.

LXXIX, figs. 6-16, 23 ; XCVI, fig. 2.

LXXIX, tig. 17.

LXXIX, tigs. 24. 25.

LXXIX, figs. 19, 20, 21, (18!); XCVI, fig. 8.

LXXIX. tig. 22.

LXXIX, figs. 26-28, 35-37.
LXXIX, figs. 3S. 39.
LXXIX, tigs. 29-34.
XCVI. fig. 4.

LXXIX. figs. 40-19; XCVI, fig. 6.
XCVI. tig. 6.
XCVI, tig. 7.

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Not figui-ed.
XL. fig. 11.

LXXX, fig. 6.
LXIV, figs. .5, 6.

LXIV, figs. 1, 2.
LXIV, figs. 3, 4.

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PALEONTOLOGY OF NEW YORK.

1

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a

m

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■a

S

LAMELLIBRANCHIATA.

539

SUMMARY.

NAME.

I
II

ni

IV

V
VI

vu

VIII

DC

X

XI

XII

XIU

XIV

XV

XVI

XVII

XVIII

XIX

XX

XXI

XXII

XXIII

XXIV

XXV i

XXVI i

XXVII

XXVIII

XXIX

XXX

XXXI

XXXII

XXXIU

XXXIV

XXXV

XXXVI

XXXVII

XXXVIII

XXXIX

XL

XLI

XLII

XLIII

XLIV

XLV

XLVI

XL VII

XL VIII

XLIX

L

LI

LU

34

13

22

9

12

18

22

3

15

57

3

2

1

5

1

15

2

2

24

13

6

13

4

5

20

3

3

4

27

1

10

15

2

13

17

1

1

1

6

1

7

9

15

4

1

1

4

3

6

5

1

6

Avjcnlopecten,

Lyriopecten, .

Pterinopecten,

Crenipecten, .

Pterinea, .

Actinopteria,

Ptychopteria,

Glyptodesma,

Leioitteria,

Leptoilesma, .

Pteronites,

Palaeopinna, .

Ectenodesma,

Limoptera, .

Byssopteria,

Mytilarca,

GoHselettia,

Modiola,

Mi>diomoi-pha,

Goniophora, .

Miorodon, .

Nucula,

Nuculites,

Leda,

Palaeoneilo,

Macrndon,

Ptychodesma,

Nyassa,

Grammysia,

Euthydesma,

Edmondia,

Spbenotus,

Si)athella, .

Conocardium,

Panenka, .

Qlyptocardia,

Pi-SBcardium,

Paracardium,

Pararca, .

Cardiopsis, .

Lunulicardiuin,

Paracyclas, .

Schizodus,

Prothyria,

Solemya, .

Tellinopeis, .

Cimitaria, .

Pholadella, .

Phthonia, .

Orthonota,

Palteosolen,

Cypricardinia,

i

12
4

8

1
5

2

11

1

2
2

'9
7
4
9
4
4

10
1
1
3

15

IH

7

7

8

10

10

22

'3

55
3

540

PALEONTOLOGY OF NEW YORK.

SUMMARY— Continued.

1

NAME.

1
1

9

1

1

1

S

1

i

M
1

1

1

LIII

LIV

LV

LVI

LVII

LVIII

LIX

LX

LXI

LXII

LXIII

LXIV

LXV

4
3
10
4
2
1
1
1
2
1
1
1
1

Palieanatina,

Prorhynchus,

Glossites, .

Elymella,

Sanguinolites,

Palffiomya,

Promacrus,

Cytherodon,

Dystactella,

Modiella,

Me^ambonia,

Amnigenia.

Allocardium,

1

1
1

1

3
1

1

1
1

i?
1

n

4
3

7

2

1

1
1

1

65

530

16

41

21

174

2

9

252

1

35

ALPHABETICAL ARRANGEMENT OF THE GENERA AND SPECIES.

Actiiiopteria, Hall. 1883
A. aui-iculata. Hall,
A. decussata, Hall,

A. Boydi, Conrad,

A. delta. Hall, .

A. Doris. Hall, .

A. epsilon. Hall,

A. eta. Hall,

A. exiraia. Hall,

A. iota, Hall,

A. kappa. Hall,

A. muricata. Hall,

A. pei-obliqua, Conrad.

A. perstrialis, Hall, .

A. pusilla. Hall,

A. subdecussata. Hall,

A. tenuistriata. Hall,

A. theta. Hall, .

A. zeta. Hall,

Allocardiuni, Hall. 1884
A. alternatum, Hall, .

Aniiii{;enin, Hall. 1883
A. Catskillen.si.t, Vanuxem,

AvicHlopecten, McCoy. 1851

A. tequilateralis, Hall,

A. bellus, Conrad, .

A. cancellatus. Hall, .

A. Caroli, Winchell,

A. celaus. Hall, .

A. Cleon, Hall.

A. convexua, Hall,

A. dolabriformis, Hall,

A. duplicatua. Hall, .

A. ellipticus, Hall, .

A. exacutus. Hall,

A. fasciculatus, Hall,

A. fomiio. Hall, .

A. Idas, Hall,

A. ignotua. Hall,

A. insig-nia. Hall, .

A. Itya, Hall, .

A. laiitua, Hall,

A. iniicronatua, Hall, .

A. ornatua. Hall,

A- patuluB, Hall,

AOE. PLATE AND I'IGUHB.

121 LXXXIV, fig. 15.

Ill XVII, figs. 24, 28 ; XVIU, figs. 1-15 ; XX, tig. 19 ; LXXXIV,

fig. 4.

113 XIX, figs. 2-24, 26-30 ; LXXXIV, figs. 16, 17.

121 XXIII, fig. 3.

109 XVIL tig. 4.

122 XXIII, tigs. 4 (5, 6 t), 8.

124 LXXXIV, figs. 8-11.

107 XXV. tig. 1.

127 LXXXIV, tig. 7.

128 LXXXIV, fig. 13.

108 XVII, figs. 1-3.

116 XIX, fig. 31 ; LXXXIV, fig. 14.
118 XXIII, figs. 2, 7 ; LXXXIV, fig. 12.

117 LXXXIV, fig 3.

110 XVII. figs. 23, 25-27, 29-31 ; XIX, fig. 25.
120 LXXXIV, figs. 5, 6.

125 LXXXIV, figs. 18, 19.

123 XXIII, tig. 9 ; LXXXIV, figs. 1, 2.

Explanation of fig. 15, plate XXIV.

516 XL, figs. 1-4 ; LXXX, fig. 12.

19 LXXXII, fig. 1.

35 II, figs. 5, 6, 9 ; LXXXI, fig. 8

18 VII, figs. 12, 14-19.

29 IX, fig. 5.

23 VII, figs. 29, 30.
6 I, fig. 1.

28 VII, figs. 22, 23.

26 Vn, fig. 21.

17 VII, figs. 1-7 ; LXXXI, figs. 9, 10.

25 VII, fig. 31.

8 III, figs. 18-22.

11 V, figs. 9-17 ; LXXXI, figs. 1-4.

9 V, figs. 20, 21.

13 III, figs. 1, 2 ; XXIV, fig. 4.

33 I, fig. 2.

34 I, fig. 8 ; III, fig. 13; LXXXI, fig. 7.

20 VII, fig. 13.

14 III, figs. 16, 17 ; LXXXI, fig. 5.
38 III, fig. 15.

37 II, figs. 7, 8 ; III, fig. 14.

24 VU, figs. 32, 33.

09

542

PALEONTOLOGY OF NEW YORK.

ALPHABETICAL ARRANGEMENT— Continued.

FLATS AJTD FIQDRB.

Aviculopecten pecteniformis, Conrad, 4 I, fip. 9.

A. Phorcua, Hall,

A. plenus. Hall,

A. princeps, Conrad, .

A. riigfsstriatas. Hall,

A. scabridas. Hall,

A. signatus. Hall,

A. squama. Hall,

A. striatus. Hall, .

A. tenuis. Hall, .

A. (Crenipecten ?) incultus. Hall.

A. (Pterinopecten t) invalidu.s. Hall, .

A. (Pterinopecten t) terminalis, HaU,

Byssopteria, Hall.
B. radiata. Hall,

1883.

10 V. fi^. 22.

21 XXIV, lis-. 3.

1 1, fiffs. 10, 11; V, liffs. 18, 19, 23, 24; VI, fi^. 1-9; XXIV,

fig-. 7 ; LXXXI, fiffa. 13-17.

1.5 VII. figs. 8-11 ; LXXXI, figs. 11, 12.

7 III. figs. 3-12.

29 VII, fig. 24.
27 VII, fig. 20.

22 X. figs 3, 4.

39 VII, figs. 27, 28 ; LXXXI, fig. 6.

30 IX. fig. 3.

31 I, fig. 18; LXXXII, fig. 21.

32 I, fig. 3.

252 XXXII, figs. 21, 22 ;;LXXX, fig. 11.

Cardiopsis, Meekand Worthen. 1861.

C. radiata. Meek and Worthen, . . 433 LXX, fig. 25.

Ciniitaria, Hall. 1870.
C. angulata, n. sp.,
C. corrugata, Conrad, .
C. elongata, Conrad, .
C. recurva, Conrad,

468 LXXVIL fig. 15.

465 LXXVII, figs. 1-4.

4BH LXXVII, figs. 5-8.

467 LXXVII, figs. 9-14, 16.

Clinopistlia, Meekand Worthen. 1870.

C. 8uhna.«uta, Hall and Whitfield, . 512 LI, figs. 32, 33 ; XCV, fig. 31.

C. telliniformis. Hall, ... 613 LI, figs. 28-31.

Conocardilim, Bronn. 1835.
C. concinnum. Hall, .

C. cuneus, Coni-ad

C. cuneus, vai-. attenuatum, Coni'ad,

C. cuneus, var. nasutum. Hall,

C. cnneuB. var. trigonale. Hall,

C. denticulatum. Hall, .

C. Ehoraceum, Hall, .

C. inceptum. Hall, Lower Helderberg,

C. liratum. Hall,

C. normalp. Hall, . . . ,

C. Ohioense, Meek, .

C. reliquum. Hall, . . . ,

C. tegulum. Hall,

Crenipecten, Hall.
C. ampins. Hall,.
C. crenulatus. Hall,
C. glaber. Hall, .
C. impolitu.o. Hall,
C. Leon. Hall. .
C. liratus. Hall, .
C. micropteriis, HaU,
C. obsoletns. Hall, .
C. Winchelli, Meek, .

1883.

1809.

Cypricardinia, Hall.

C. arcuata, n. sp.,

C. consimilis, n. sp.,

C. 1 cylindrica. Hall and Whitfield,

414 LXVin. figs. 26, 27.

409 LXVII. figs. 1-32 ; LXVIII, figs. 1, 4-16 ; XCIV, figs. 11, 12.

410 LXVII, fitrs. i-n.
410 LXVII, figs. 12-20.

410 LXVIL fig. 28 ; LXVIII, figs. 1, 4-16 ; XCIV, fig. 11.

413 LXVIII. figs. 24, 25.
412 LXVIII. figs. 20-23.

415 LXVIII, fig. 32.

414 LXVIII, figs. 28, 29.

411 LXVIII. figs. 17-19.
411 LXVIIL figs. 2, 3.

415 LXVIIL fig. 3:^.
415 LXVIII, figs. 30, 81.

81 IX, figs. 9, 13. 18.

82 IX. figs. 6, 7, 8, 15, 16, 17.

85 IX. figs. 20, 22 ■(

83 IX. fig. 14; LXXXIIL fig. 10..

88 IX, fig 12 ; LXXXIII, fig. 8.
87 IX fig. 24 ; LXXXIII, fig. 9.

86 IX. fig. 23.

84 IX. figs. 19, 21.

89 IX, figs. 1, 2, 4, 25-30.

486 LXXIX, fig. 17.

48« LXXIX, figs. 19, 20, 21, (18 ?) ; XCVL fig. 3.

486 LXXIX, figs. 24, 25.

LAMELLIBRANCHIA TA.

543

ALPHABETICAL ARRANGEMENT— Continueri.

PLATK AND KIGURK.

Cypi-icai-dinia inrlenta, Conrad,
C. planulata, Conrail,
C. sulcifei-us, Winchell, .

Cytherodon, HaU. 1873.
C. nasutos. Hall,

Ectenodesma, Hall. 1883.
E. biro.stratura. Hall, .

Edinoudia, De Koninck. 1844.
E. Burlingtonensis, White and ■Whit-
field,

E. depressa. Hall, .
E. ellipsis, n. sp.,
E. Philipi, Hall, .
E. rhomboidea. Hall. .
E. % aubcaiinata. Hall, .
E. subovata, n. ap.,
E ? tenuistiiata, n. sp., .
E. transvei'sa, n. sp., .
E. tumidula, n. sp.,

Elymella, »ov. gen.
E. fabalis, n sp ,
E. levata, n. sp.,
E. nuculoides, n. sp., .
E. patula, n. sp., .

Euthydesnia, .vov. obn.
E. subtextile. Hall. .

Glossites, Kov. qkit.

G. amyirdalinus. Winchell,

O. depressiis, n. sp.,

G. ellipticus, n. sp., ,

G. lingiialiB, n. sp.,

G. patulus, n. sp..

G. procerus, n. sj).,

G. rudicula. n. sp.,

G. subnasiitus, n. sp.,

G. subtenuis, n. sp., .

G. teretis, n. sp., .

Glyptocardla, »ov. obx

G. spcciosa. Hall,

Glyptodesnia, Hall. 1883.
G. erectum, Conrad, .

G. erectum, var. obliquuni, HaU,
G. occidentale. Hall,

Goiiiopliora, Phillips. 1848.
G. acuta. Hall, ....

G. ? alata, n. sp

G. carinata, C'onra<1, .

G. Chemungensis, Yanuxeni,

G. firlaucus, Hall,

G. Hamiltonensis, Hall, .

48.") LXXIX, figs. 6-16, 23 ; XCVL %. 2.
484 LXXIX, fig-s. 1-5.
487 LXXIX, tiif. 22.

511 LXXV, fif-s. 10-12 ; XCV, Hg. ;i()

242 XXIII, figs. 27-30 ; LXXXIV, tig. 20.

390
391
392
387
386

389
393
389
388

LXIV, fig. .2; XCV, tigs. 13, 14.

LXIV, fig. 32.

LXIV, fig 25.

LXIV, tigs. 9. 11-14. 17. 29 ; XCV, tigs. 1-1.

LXIV, tigs. 7, 8 ; LXXV. tig. 43 ; XCV, tigs. 15, 16.

Explanation of PI. LXIV, tig. 31.

LXIV, tigs. 18, 19, L'O, 26, 27, 28, (10, 21?) ; XCV, tigs. 9-12.

LXIII, tigs. 9, 10 ; XCV, fig. 17.

LXIV. tig. 24.

LXIV, tigs. 15, 23, (16'() ; XCV, figs. 5-8.

502 XL, figs, r., 9.

504 Not figui-ed.

503 XL, figs. 6, 7. 8, 10?

505 XL, fig. U.

385 LXIII, figs. 11-16 ; XCIII, figs. 28, 29.

496
498
497
501
499
498
500
495
494

XL, tigs. 13, 14.

XL, figs. 15, 17 ; XCVI, fig. 12. '

XCVI, tig. 8.

XL, figs 16, 19 ; XCVI, figs. 9-11.

XCVI, figs. 1.5, 16.

XCVI, fig. 13.

XCVL tig. 17.

XCVI, tig. 14.

XL, figs. 12, 20.

XCVI, tig. 18.

426 LXX, figs. 2-9 ; LXXX, fig. 10.

153 XL figs. 1-10; XIL tigs. 1-3, .'i-9; XIII, tigs. 1-4, 12-15 ;
XXV, tigs. 14-17; LXXXVI, figs. 1-8; LXXX VII, figs. 1-3
155 XII, tig. 4 ; XIII. figs. 5-11.

157 XV, fig. 12 ; LXXXVI, fig. 9.

295 XLIII, tigs. 1-3.

294 XXXIV, tig 7 ; XLII, tig. 3.

301 XLII. fiK-. 11 ; XLIV, tigs. 6-8.

303 XLIV, figs. IS, 20, 22.

299 XLIII, fig. 16 ; XLIV, figs. 10-17.

296 XLIII, figs. 8-15, 17-21.

544

PALEONTOLOGY OF NEW YORK.

HktOL

Goniophora Ha, Hall,

G. minor, n. sp.,

O. peraiiffulata. Hall,

G. rujfosa, Conrad,

G. subrecfa, n. sp.,

G. trig-ona, n. Rp., .

G. truiicata. Hall,

Oosselettia, Barrois.
O. retusa. Hall, .
G. triquetra, Conrad,

ALPHABETICAL ARRANGEMENT— Continued.

AOB. FLITB AVD FIODRH.

300 XLIL fiff 13: LXV, fig 20.

30!) XLII. fij.'S. 4-6.

293 XXXIV. fijrs. 1-6 ; XLII, figs. 1, 2.

297 XLII. tips. 7. 8<j ; XLII I. H^s. 4-7.
304 XLII. fips. 14, !.■> ; XLIV, figs. 19, 21.
302 XLII. fig 12; XLIV. fig. 9.

298 XLII, figs. 9, 10 ; XLIV, figs. 1-5.

1881.

Grainniysia, De Vemeuil

G. alveata, Conrad, .

G. arcuata. Conrad,

G. bellatula. Hall,

G. bisulcata, Conrad,

G. cii-ciilans. Hall,

G. communis, n. sp.,

G. constncta. Hall, .

G. duplicata. n. sp.,

G. elliptica. Hall,

G. electa. Hall,

G. Eriopia, Hall,

G. glabra, n. sp., .

G. globosa. Hall,

G Hannibalensis, Shumai-d,

G. lirata. Hall. .

G. magna. Hall,

G. nodocostata. Hall, .

G. obsoleta. Hall, .

G. ovata, n. sp, .

G plena, n. sp.,

G. pi-aecursor. Hall, .

G. secunda. Hall, .

G. Bubarcuata, Hall, .

G. (?) Rubnasuta. Hall,

G. undata. Hall,

G. znnata. Hall,

G. (Spbenomya) cuneata, Hall

Leda, Schumacher. 1817

L. brevii-ostris. Hall, .

L. divei-sa. Hall,

L. obscura, n. sp.,

L. pandoiiformis, Stevens,

L. i-ostellata, Conrad,

Leiopteria, Hall. 1877,

L. Bigsbyi. Hall,

L. Chemungensis, Vanuxem,

L. Coni-adi, Hall.

L De Kavi. Hall, .

L. Gabbi.'Hall, .

L. Greeni. Hall, .

L. IseviR. Hall,

L Leai. Hall. .

L. liiiguiformis. Hall,

L. Mitrhelli. Hall,

L. Oweni. Hall,

L. Rafinesqoii, Hall, .

1847.

266 XXXIIL figs. 1. 2.

265 XXXI, figs. 9-17 j LXXXYII, fig. 12.

370 LVIL figs. 1, 2 ; LX. figs. 1-11.

373 LXI. figs. 1-9 ; LXIII, fig. 6 ? ; XCIII, fig. 27.

367 LXIII, 1-3.

359 LIV, figs. 1-16 ; LVI. fig. 1 ; XCIII, fig. 25.
3«4 LVII, figs. 3-6 ; LVIII. fig. 13

378 LXI. figs. 24-28 ; XCIII, fig. 20.

377 LIX. figs. 13-20, (4, 5 ?) ; LXX VIII, figs. 26, 27.

380 XCIII, fig. 23.

365 LVIII, figs. 1-12, (1, 5, 6 !).
363 LVI. fig. 8 J LVII. fig. 10.

368 LXIU. figs. 7, 8.

369 XCIII. tig. 24.

372 LXII. figs. 10-19.

381 LXI. figs. 29. 30, 33.

371 LIX, figs. 6-12.

862 LVI. figs. 4-7 ; LVH. fig. 9.

360 LV, figs. l-U; LVI, figs. (2,8?); LVII, figs. 7, 8; XCVI,

figs. 19-21.

366 LIX, figs. 21-27.
3.58 XCIU. fig. 22.

382 LXI. figs. 31, 32.
376 LIX. fig. 1.

376 LIX. figs. 2. 3.

375 LXI. figs. 10-22 ; XCIII, fig 26.

507 LXIV. figs 5. 6.

379 LXI. fig. 23 ; LXIV, fig. 30 ; XCIIL fig- 21.

373 LXIII. figs. 4. 5.

383 LXII, figs. 1-9 ; XCIII, fig. 19.

32fl XLVIL figs. 38-41.

329 XLVII, figs. 31-37.

331 XLVII. fig. 48.

332 XLVII. figs. 49. 50.

330 XLVII, figs. 42-47.

165 XX. figs. 3, 11, 13-15; LXXXVIII, fig. 23.

172 XXn. figs. 17, 18.

1.59 XX. figs. 1, 2. 4 ; LXXXVIH. figs. 1-4.

164 XIX. fig. 1 ; XX, figs. 16-lt<; LXXXVIII, figs. 5-10.

169 LXXXVIII. tig. 14.

IKO XX. Hgs. 9, 12 ; LXXXVIII, figs. 21, 22.

1.58 XVIL fit's 5-11 ; XX. fig. 5.

168 LXXXVIII. figs. 24, 2.5.

173 LXXXVIII, fig. 20.

166 XX. fig. ^ ; LXXXVIII, fig. 26.

170 XX. fig. 10.

161 XV, fig. 11 ; XX, figs. 6, 7; LXXXVIII, figs. 27, 28.

LAMELLIBRANCHIA TA.

545

ALPHABETICAL ARRANGEMENT— Continued.

PAGE.

PLATE AND PIGDRE,

Leiopteria Sayi, Hall,
L. ToiTeyi. Hall, .
L. Troosti, Hall, .

Leptodesma, Hall. 1883

L. acutirostrum. Hall,

L. Agassizi, Hall, .

L. alatum. Hall, .

L. aliforme. Hall, .

L. arciforme, Hall,

L. aviforme. Hall, .

L. Becki, Hall, .

L. BiUingsi, Hall, .

L. Biton, Hall, .

L. Cadmus, Hall, .

L. CUtus, Hall, .

L. cnmplanatum. Hall,

L. Corydon, Hall,

L. Ci-eon, Hall,

L. curvatum. Hall,

L. Demus, Hall,

L. disparile. Hall,

L. extenuatum. Hall,

L. flaccidum. Hall,

L. Hector, Hall,

L. Jason, Hall, .

L. lepidum. Hall, .

L. Lesley!, Hall,

L. Liehas, Hall,

L. longispinum. Hall,

L Loxias, Hall,

L. Lysander, Hall,

L. Maclurii. Hall. .

L. Marcollense, Hall, .

L. Mathei-i. Hall, .

L. Medon, Hall. .

L. Mentor, Hall, .

L. Mortoni, Hall,

L. mytilifoi-rae. Hall,

L. navifoi-me. Hall, .

L. Nereus. Hall,

L. Orcus. Hall, .

L. OiiKlea. Hall, .

L. Orus. Hall, .

L. patulum. Hall, .

L. Pelops, Hall, .

L. Phaon, Hall, .

L. i>oten8. Hall, .

L. potens, var. juvens. Hall,

L. propinquum. Hall,

L. pi-otextuin, Conrad,

L. quadratum, Hall, .

L. i-obustum. Hall, .

L Rogersi, Hall,

L. rude. Hall, .

L. Shumardi, Hall,

L. sociale. Hall.

L. Rpinig-erum, Conrad,

L. Stephani, Hall, .

L. ti-uncatum. Hall, .

L. umhonatum. Hall,

L. umbonatum, var. depressum,

Hull.

162 LXXXVIII, figs. 15-20.

174 XXII, figs. 6, 7 ; LXXXVIII, fig. 11.

167 LXXXVIII, figs. 12, 13.

234 XCL fig. 21.

182 LXXXIX, figs. 17-19.

218 XC, figs. 26, 27.

220 XXII, fig. 28 ; XCI, fig. 2.

229 XCI, fig. 12.

224 XCI, fig. 8.

185 XXII, figs. 3-5.

192 LXXXIX, figs. 12-15. '

222 XCI, fig. 1.
2ul XC, figs. 6, 7.

210 XC, fig. 21.

227 XXII, fig. 2.

212 XC, fig. 22.

202 XC, tigs. 1 1-13.

196 XXV, tig. 5.

203 XC, figs. 15, 16.

186 XXV, figs. 2-4 ; LXXXIX, figs. 23, 24.
207 XXII, tig 23 ; XC, tigs. 17, 18.

225 XCI, fig. 9.
209 XC, figs. 19, 20.

213 XCI, figs. 4-6.

193 XXI, fig. 40 ; LXXXIX, fig. 16.

223 XCI, fig. 7.

232 XXI, figs. 35-39 ; XCI, figs. 19, 20.

179 XXI, tigs 14, 17-19 ; LXXXIX, figs. 2-A.

204 XC, tig 14.

216 XXII, fig. 22 ; XC, fig. 34.

228 XXV, figs. 8. 13; XCI, figs. 13, 14.

175 XVII, fig. 12.

193 XXII, tigs. 8, 9, 10 ; LXXXIX, fig. 25.

197 XC, tigs. 1-4

205 XC. tig. 5 ; XXIII, fig. 15 1

190 XXI, figs. 29, 31, 32 ; LXXXIX, figs. 9-11.

235 XXV. figs 7, 11 ; XCI, figs. 22-25.
200 XXII, fig. 15 ; XXIII, tig. 1.

217 XC, figs. 31-33.
215 XC, fig. 23.

206 XXV, figs. 6, 9, (10 1) ; XC, fig. 8.

219 XC, tig. 30.

226 XCI, tigs. 10, U.

214 XC, figs. 28, 29.

230 XCI, fig. 18.

188 XXI, figs. 21, 30 ; XXII, figs. 11, 12, 19, (20!), 21 ; LXXXIX, fig.7.

189 XXII, tig. 16.

231 XCI. tigs. 16, 17.

183 XXI. tigs. 22, 23.

233 XCI, tig. 15.

181 XXI, figs. 15. IR, 20 ; LXXXIX, fig. 8.

176 XXL tigs. 1-9.

221 XXV, fig. 12 ; XCI, fig. 3.

180 LXXXIX. figs. 5, 6.

187 XXI, figs. 24-28, (33. 34 1)

177 XXI, tigs. 10-13 ; LXXXIX, fig. 1.

194 LXXXIX, figs. 20-22.

211 XC. figs. 24, 25.

198 XXII. fig. 13; XC, fig. 9.

199 XXll, tig. 14 ; XC, fig. 10.

546

PALEONTOLOGY OF NEW YORK.

MAMK.

Liinoptcra, Hall. 1870.
L. cancellata. Hall,
L. cnrvata. Hall, .
L. macniptera, Connul,

L. nlKwIeta, Hall,
L. pauperata. Hall,

Liiiiiiilicardiiini, Munster. 1S40.

L. curtuin. Hall, .

L. frag-ile. Hall,

L. Mai-celleuse, Vaiiuxem, .

L. orbiciilai-e. n. sp ,

L. ornatuin. Hall,

L. ru.le. Hall,

L. transvei-siim, n. sp.,

Lyrlopecten, Hall. 1877.

L. anomiaeformis. Hall,

L. cynibaloii, Hall,

L. Dai-danus, Hall,

L. fasciatiiB, Hall, .

L. interrailiatus. Hall,

L. macnxlontu.s Hall,

L magiiifiois. Hall, .

L. orbiculatus. Hall,

L. parallelodontus. Hall, .

L. P()ly«loni.s Hall,

L Priamus, Hall,

L. solox. Hall,

L. tricostatus, Vanuxem, .

Macrodon, Lycett. 1885.
M. Cheiuunffensis, Hall, .
M. Hamiltonis, Hall, .
M. ovatiifl. Hall,

Megambonia, Hall. 1859.
M. cariliiformis. Hall,

Microdon, Conrail. 1842.

M. (C) bellisti-iatus, Conrad,

M. (C.) (;i>mplanatu.s. Hall, .

M. (C.) grejfarius. Hall, .

M. (C.) major, n. sp..

M. (C.) re«er\'atU8, Hall, .

M. (C.) tenuistriatus, Hall, .

Modiclla, Hall. 18«3.
M. pygina>a, Conrad, .

Mudiola, Lamai-ck. 1801.

M (Mytilops) metella,

M. (Mytilops) prtecedens, Hall,

Modioiiiorphiiv Hall.
M. afBnis, n. op.,
M alta, Conrail,
M. arcuata. Hall,

ALPHABETICAL ARRANGEMENT— Continued.

PAOB. PLATK AND FIUUKK.

244 XXVI, figs. 1-4 ; XCII, figs. 1-3.

250 XXVIII, figs. 1-3.

246 XXIV, fig. 14 ; XXVI, figs. 6-9 ; XXVII, figs. 1-10; XXVIII,

figs. 4, 5 ; XXIX, figs. 1-4 ; XCII, figs. 4-9.
249 XXIX, figs. 5, 6 ; XXVI, fig. 10 1 ; XCII, fig. 10.
243 XXVI, fig. .5.

437 LXXI, figs. 18-23.

434 LXXI, figs. 1-14.

435 LXXI, figs. 1.5, 16.

436 LXXI, fig. 24.

437 LXXI, figs. 25-32.
435 LXXI, fig. 17.

439 XCIV, figs. 24, 25.

53 IV, fig. 10 ; X, fig. 5 ; LXXXII, fig. 2.

47 XXIV, fig. 8.

41 I, fig. 5.

55 IX, figs. 10, 11.

44 II. figs. 1-4 ; LXXXII, fig. 5.

46 IV. fig. 9 ; VIII, figs. 9, 10.

51 VIII, fig. 8.

42 IV, figs. 3-8 ; LXXXII, fig. 3.
40 IV, figs. 1, 2.

50 VII. fig. 25.

54 X, figs. 1, 2 ; LXXXII, fig. 6.

56 XXIV, fig. 5.

48 IV, fig. 11 ; VII, fig. 26 ; X, figs. 6-12.

350 LI, figs. 11-16.
349 LI, figs. 1-7, 9, 10.

351 LI. fig. 8 ; XCIII, fig. 16.

515 LII, figs. 1-8.

308 XLII, figs. 17-20 ; LXXIII, figs. 7-22 ; LXXIV, figs. .'i-lO.

311 XLII, fig. 22 ; LXXIV, figs. 14-19.

309 LXXIII, figs. 1-6 ; LXXIV, figs. 1-4.
307 XLII, fig. 21.

312 LXXIV, figs. 11-13.

310 XLII, fig. 16 ; LXXIII, figs. 23-30 ; LXXIV, figs. 20, 21.

514 LXXVI, figs. 9-20.

268 XXXIII, figs. 23. 24 ; LXXXVII, fig. 9.
267 XXXIII, figs. 9-18.

284 XXXVII, figs. 13, 14 ; XXXV, fig. 13.

278 XXXVII, figs. 1, 2, (4, 5, 61), 7-12, 15, 16; LXXX, fig. 7.

281 XXXVI, fig. 21.

LAMELLIBRANCHIA TA.

547

ALPHABETICAL ARRANGEMENT— Continued.

Modiomorpha Clarens, n. sp.,
M. complanata. Hall, .
M. concentrica, Conrad,

M. cymbula. Hall, .

M. hyalea. Hall,

M. linguiformia, Hall,

M. macilenta. Hall,

M. mytiloides, Conrad, ,

M. neglecta, Hall,

M. ponderosa. Hall,

M. putillus. Hall,

M. quadrula, Hall, .

M. recta, n. sp., .

M. recurva. Hall, .

H. regularis, n. sp., .

M. rig^da, Hall,

M. Schoharie, Hall, .

M. subalata, Conrad,

M. subalata, var. Chemungensis, n.

M. sabangulata, n. sp., .

M. Tioga, n. sp.,

Mytilarca, Hall. 1870.
M. attenuata. Hall, .

M. carinata. Hall

M. Chemungensis, Conrad,

M. tibristriata. White and Whitfield,

H. gibbosa, Hall, ....

M. lata. Hall

M. occidentalis, White and Whitfield,

M. pyramidata. Hall, .

M. regularis. Hall, ....

M. simplex. Hall, ...

M. umbonata. Hall,

M. (Plethomytilus) arenacea. Hall,

M. (Plethomytilus) Knappi, Hall, .

M. (Plethomytilus) oviformis, Conrad

H. (Plethomytilus) ponderosa. Hall,

273

272
275

282
292
274
280
277
290
271
271
289
28G
288
270
287
269
283
284
287
291

PLATE AND FIQURE.
XLI, fig. 4.

XXXIV, fig. 14 ; XLI, fig. 3.

XXXIV, figs. 9, 10 ; XXXV, figs. 1-5 ; XXXVI, figs. 1-lG, (17,
18?)

XXXVI, figs. 19. 20.
XLI. tigs. 28-30.
XXXIV. tigs. (15?), 16, 17.

XXXVII, tig. 17 ; XXXIX, figs. 17-21.
XXXVIL fig. 3 ; XXXVIII, figs. 1-16.
XLI, fig. 13.

XXXIV, figs. 11, 12 ; XXXV, fig. 8.
XLI, figs. 1, 2.

XLI, figs. 18-26.

XXXV, fig. 9.
XLI, fig. 17.
XXXV, fig. 12.
XLI, figs. 14-16.

XXXIV, tig. lA ; XXXV, fig. 14.

XXXV, tigs. 6, 7 ; XXXIX, figs. 1-14, 16.
XLI. figs. 5, 6, 8, 9, 11, (7, 10 ?) ; XXXIX, fig. 15.
XXXV, figs. 10, 11.

XL, fig. 18.

260 XXXII, fig. 20.

259 XXXII, figs. 15-19 ; XXXIII, fig. 8.
258 XXXII, figs. 8-11, 13, 14.

264 XXXIII, figs 6, 7 ; LXXXVII, fig. 6.

262 XXXIII, fig. 20 ; LXXXVII, tig. 7.

262 XXXIII, fig. 22.

263 XXXIII, tigs. 3-5 ; LXXXVII, fig. 11.

256 LXXX, figs 1-3

260 XXXII, fig. 12.

261 XXXIIL figs. 19, 21.

257 XXXII, tigs. 1-7.

253 XXX, tig. 1 ; LXXXVII, fig. 10.
256 LXXXVII, fig. 13.

255 XXXI, figs. 1-8 ; LXXXVII, fig. 8.

254 XXX, figs. 2-7.

Nucula, Lamarck. 1799.

N. bellistriata, Conrad,

N. corbulifoi-mis, .

N. diffidens. n. sp., .

N. globularis, n. sp.,

N. Houghtoni, Stevens,

N. lamellata. Hall, .

N. lirata, Conrad,

N. Neda, Hall and Whitfield,

N. niotica. Hall and Whitfield,

N. Randalli, Hall,

N. subelliptica. Hall, .

N. umbonata. Hall,

N. varicosa. Hall,

Niiciilites, Conrad. 1S41.
N. cuneiformis, Conrad,
N. Nyssa, Hall,
N. oblongatus, Conrad,
N. triqueter, Conrad,. .

318 XLVI, figs. 1-9.

319 XLVI, figs. (10, 11 ?), 24-34, (35, 36, 37 ?).
322 XLV, figs. 12, 14.

322 XCIII, fig. 6.

323 XLV, figs. 29-31.

320 LI, figs. 18-21 ; XLV, fig. 13 ; XCIII, fig. 7.

316 XLV, figs. 5, 11, 15, 17-22, 24, 25 ; XCIU, fig. 5.

314 XLV, figs. 3, 4.
313 XLV, figs. 1, 2.

315 XLV, figs. 6-10, 16, 23, 26, 27 ; XCIII, figs. 1-3.

317 XLV, fig. 28.

321 XLVII, figs. 51, 52.

319 XLVI, figs. 12-23 ; XCIII, fig. 4.

325 XLVII, figs. 13-16.
328 XLVII, tigs. 29, 30.
324 XLVII, figs. 1-12.

326 XLVII, tigs. 17-28 ; XCIII, figs. 8-10

548

PALEONTOLOGY OF NEW YORK.

ALPHABETICAL ARRANGEMENT— Continued.

1841

1870

KAMK.

Nyassa, Hall. 1870

N. argiita. Hall, .
N. vlliptica. Hall,
N. recta. Hall, .
N. subalata. Hall, .

Orthouota, Coiira«l
O. carinata, Conratl,
O. eusiformis. Hall,
O. t pai-vula. Hall,
O. rigida, n. sp.,
O. undulata, Coni-ad,

Palseanatina, Hall
P. an(fU8ta, n. sp.,
P. sinuata, n. sp., .
P. solenoides, n. si>.,
P. typa, Hall,

Palseonello, Hall. 1870,

P. angusta, n. sp.,

P. aiata. Hall,

P. attenuata. Hall,

P. bi-sulcaU, Hall, .

P. brevis. Hall, .

P. constricta, Conrad,

P. con.stricta, var. flexuosa. Hall

P. ? dubia, n. sp., .

P. eloiigata, Hall,

P. emarginata, Conrad, .

P. fecunda. Hall,

P. filosa, Conrad, .

P. maxima, Conrad, .

P. muta. Hall,

P. perplana. Hall,

P. plana, Hall,

P. Hulcatina, Conra<l, .

P. tenuisti-iata, Hall,

P. truncata. Hall,

P. Virginica, n. sp..

PLATK AND KKiUKIS.

Paleeopinua, Hall.
P. flaliella. Hall,
P. recurva. Hall, .

Paiieuka, Barrande
P. abrupta, n. sp.,
P. ie(iuilat«ra. Hall,
P. alternata, n. sp.,
P. costata, n. sp., .
P. degencr, n. sp.,
P. dicbotoma, HaU,
P. elevata, Conrad,
P. Hei-o. Hall,
P. Lincklfeni, Hall,
P. mollis, n. sp.,
P. multiradiata, n. sp
P. potens, n. sp., .
P. Poulsoni, Conrad,
P. radians, Conrad,

1883.

1881

354
357
35G
355

479

480
482
481
478

LIII, figs. 7-20.
XXXIV, fig. 8.
LIII, figs. 1-G.
LIII, figs. 21-26.

LXXVIII, figs. 34, 35.

LXXVIII, tig. 36.

LXV, figs. 2. 3 ; LXXVIII, figs. 29-32.

LXXX, fig. 6.

LXXVIII, figs. 37-42.

490 LXXIX, figs. 29-34.

491 XCVI. tig. 4.

489 LXXIX, tigs. 38, 39.

488 LXXIX, tigs. 2fi-28, 35-37.

344 XCIII, fig. 11.

341 L, tig. 23.

346 L, tigs. 34-39.

344 L, figs. 12-14.

342 L, figs. 24-33.

333 XLVIII, figs. 1-16 ; LI, fig. 17.

334 XLVIII, tigs. 17-20.
348 XCIII, tig. 15.

345 XLVIII, tig. 39 ; XCIII, fig. 11a.

338 L, figs. 1-11.

336 XLIX, figs. 13, 15-24.

343 XLIX, tigs. 33-38.

335 XLVIII, figs. 29-38.

337 XLIX, figs. 25-32.

339 L, figs. 15-22 ; XCIII, fig. 12.
334 XLVIII, figs. 21-28.

347 L, tigs. 42-46.

336 XLIX, figs. 1-12, 14 ; XCIII, fig. 13.
347 L, tigs. 40, 41.

340 XCIII, fig. 14.

240 XXV, fig. 18 ; LXXXVII, fig. 4.

241 XXV, fig. 19.

LXIX, fig. 11 : XCIV, fig. 16.

LXIX, figs. 4, (7 t) ; XCIV, tig. 17.

Not figui-ed.

XCIV, tig. 15.

XCIV, fig. 14.

LXX. fig. 21 ; XCIV, fig. 13.

Not figured.

LXIX, fig. 3.
,^w LXIX, figs. 12-14.
420 LXXX, tigs. 8, (9 ?).
417 LXIX, tig. 5 ; XCIV, fig. 18.
422 LXIX, figs. 8, 10.
425 Not figured.
422 LXIX, tig. 9.

423
419
416
419
424
416
425
418
420

LAMELLIBRANCHIA TA.

549

ALPHABETICAL ARRANGEMENT— Continued.

PLATE AND PIQDRE.

Panenka i-etusa. Coni'ad,

P. robusta, Hall,

P. ventricosa, n. sp., .

Paracardiuin, BaiTamie. 1881.
P. Doi-is, Hall, .

Paracyclas, Hall. 1843

P. Chemungensis, n. sp.,

P. elliptica. Hall, .

P. ei-ecta, n. sp.,

P. ig-nota. Hall,

P. lirata, Conrad,

P. Ohioensis, Meek,

P. ? pauper. Hall,

P i-otunda. Hall, .

P. tenuis. Hall, .

Pararca, mov. oen.
P. erecta. Hall, .
P. venusta, n. sp., .
P. pi-aecedens, n. sp., .
P. Sao, Hall, .
P. transversa, Hall, .
P. neglecta, n. sp.,

1870,

PholodeUa, HaU.
P. Newberryi, Hall,
P. parallela. Hall, .
P. radiata, Conrad,

Phthoiiia, Hall. 1870.
P. cylindrica. Hall,
P. truncata, n. sp., .
P. nitiila, n. sp., .
P. nodicostata. Hall,
P. sectifrons, Conraii,
P. lii-aU, Hall,

Prsecardiiim, Baii-ande
P. vetustum. Hall,

Proiuacrus, Meek. 1871
P. cuneatus. Hall,

Prorhyiichus, nov

P. aiig'ulatum, n. sp.,
P. nasutum, n. sp.,
P. quadratum. Hall,

Prothyris, Meek. 1869,
P. alata, n. sp., .
P. exuta, n. sp.,
P. laticcolato. Hall,
P. planulata. Hall, .

Protomya, nov. ok».
P. oblonga. Hall,

70

1881.

421
424
417

444

441
442
446
444

432
431
429
430
429
432

LXIX, fig. 6.
LXX. figs. 22-24.
LXIX, tig-s. 1, 2.

428 LXX, figs. 10, 11.

443 XCV, fig. 23.

440 LXXII. tigs. 23-33 ; XCV, tig. 18

445 XCV, fig. 22.

LXXII, fig. 34.

LXXIL tigs. 2-19 ; XCV, fig. 19.

LXXII, fig 1 ; XCV, fig 24.

LXXV, figs. 24-26 ; XCV, fig. 20.

LXIII, figs. 18, 19; XCV, fig. 21.

t4» ijAiii, ngs. lo, i»; AUY, ng. 21.
443 LXXII, tigs. 20-22 ; XCV, fig. 25.

LXX, fig. 16 ; XCIV, figs. 20, 21.

XCIV, fig. 22.

XCIV, fig. 19.

LXX, tig. 17.

LXX. figs. 12, 14, 15.

LXX, tig. 13.

471 LXXVIII, fig. 25.

470 LXXVIII, tigs. 22-24.

469 LXXVIII, tigs. 15-21 ; XCVI, tig. 1.

473 LXXVIII, figs. 1-4.

476 XCIV, fig. 4.

477 XCIV, figs. 5, 6.

474 LXXVIII, tigs. 5-9.

475 LXXVIII, tigs. 10-13.

476 LXXVIII, fig. 14.

427 LXX, figs. 18-20.

510 LXXVIII, fig. 28.

493 XCVI, fig. 7.
493 XCVI. fig. 6.
492 LXXIX, figs. 40-49 ; XCVI, fig. 5.

461 XCIV, fig. 7.

462 XCIV, fig. 9.
460 LXXVI, figs. 2-8.

460 LXXVI, fig. 1 ; XCIV, fig. 8.

509 LXIII, fig. 21.

550

PALAEONTOLOGY OF NEW YORK.

ALPHABETICAL ARRANaEMENT— Continued.

KAMB.

PLATB JLSD PKIDRB.

Ptcrinea, Ooldfuss. 182t>.

P. Cheiimiif^nsis, Conrad,

P. .cimsiinilis. Hall,

P. dispandH, Hall,

P. flalwlla, ("oiinvd,

P. j^rrandis, n. sp.,

P. intei-strialif!. Hall,

P. pinguis. Hall,

P. proi-ii. Hall,

P. ri^riilii. Hall, .

P. (Vertumnia) avis. Hall,

P. (Vertumnia) rcpi-oba. Hall,

P. (Vertumnia) i-eversa, Hall,

Pteronites, McCoy. 1844.
P. inoptatus. Hall,
P. profundus. Hall,
P. rostratus. Hall,

Pterinopecten, Hall. 18S3

P. con.siHjotu.s, Hall, .

P. ci-enicostatus, Hall,

P. dig-natus. Hall,

P. dispan<lus. Hall,

P e rectus. Hall,

P. exfoliatus. Hall,

P. filitextu.s. Hall,

P. Hennes, Hall, .

P. imbecilis. Hall,

P. in.sons. Hall,

P. intermedius, Hall, .

P. Ia;tu.s, Hall,

P. multiradiatus, Hall,

P. Nei)tunus, Hall,

P. nodoaus. Hall,

P. i-eflexu8. Hall,

P. regularis. Hall,

P. spondylua. Hall,

P. snborbicularis. Hall,

P. unclosus. Hall, .

P. Vertumnus, Hall, .

P. (Aviculopecten 1) strictus. Hall

Ptychodesma, Hall and Whitfield,

1872.
P. Knappianum, Hall and Whitfield,
P. minor. Hall, ....
P. nanum, n. sj).,

Ptychopterla, Hall.
P. alata. Hall, .
P. Beecheri, Hall, .
P. elongata. Hall,
P. Eucrate, Hall, .
P. Euilora, Hall,
P. expanna. Hall, .
P. falcata. Hall, .
P. aalene. Hall, .
P. (fibl)08a. Hall,
P. Uta, UaU, .

1888.

its

100

97

93

91

96

92

102

101

105

106

104

XVI. figs. 3, 7, 10, 12 ; LXXXIV, fig. 21.

XVI, figs. 1, 2, S, 9, 11 ; LXXXIV, fig. 23.

XV, fig. 7.

XIV, figs. 1-21 ; XV, figs. I, 4-6, 8-10 ; LXXXIII, figs. 11, 12.

LXXXIII, fig. 14.

LXXXIII, fig. 14.
LXXXIV. fig. 22.

XV, fig.s. 2. 3; LXXXIIL fig. 13.

XVI. figs. 4, 13, 14.
XVI, figs 5, 6.
XXIV, figs. 9, 11, 13.
LXXXII, figs. 19, 20.

XXIV, tigs. 6, 12 ; LXXXIV. fig. 24

239 LXXXVIL fig. 5.

237 XXII, figs. 25-27.

238 XXII, fig. 24.

66 XVII, figs. 17, 18, 20, 21.

78 VIII, figs. 3, 4 ; LXXXII, fig. 14.

62 I, figs. 12, 14, 15.

76 LXXXII, figs. 11, 12.

77 LXXXH, figs. 1.5-17.

61 I, fig.s. 16, 17 ; LXXXIIL figs. 6, 7.

67 XVIL fig. 22 ; LXXXII, figs. 9, 10.

64 XVIL figs. 13-15.
75 XXIV, fig. 1.

.59 I, fig. 4.

68 XVIL fig. 19 ; LXXXIIL figs. 4, 5.

63 I, fig. 13.

57 I, figs. 6, 7.

79 VIII, figs 5-7.
60 LXXXU, fig. 13.

58 LXXXII, fig. 8.

70 LXXXIII, fig. 1.

65 XVn, fig. 16.

80 VIII, figs. 1, 2; XXrV, fig. 10; LXXXIL fig. 4.
72 II. figs. 10-19 ; LXXXIL fig. 7.

71 V, figs. 1-8 ; LXXXIII, figs. 2, 3.
74 XXIV, fig. 2 ; LXXXII, fig. 18.

353 LI, figs. 22-27.

353 XLI. fig. 27.

353 XCIII, figs. 17, 18.

139 XXIII, figs. 2.5, 2B (21, 32 1) ; LXXXV, fig. 26.

143 LXXXV, figs. 21, 22.

141 LXXXV, figs. 10-13.

133 XXIII, fig. 24 ; LXXXV, figs. 27, 28

138 LXXXV, fig. 9.

1.52 XXIIL figs. 10, 11.

136 LXXXV, figs. 6, 7.

142 LXXXV, figs. 29-31,
149 LXXXV, fig. 5.

145 LXXXV, figs. 23-25.

LAMELLIBRANCHIA TA .

561

ALPHABETICAL ARRANGEMENT— Continued.

NAME.

Ptychopteria lobata. Hall,

P. perlata, Hall,

P. Proto, Hall, .

P. Salamanca, Hall,

P. Sao, Hall,

P. sinuo-sa. Hall.

P. spatulata. Hall,

P. Spio, Hall, .

P. Thalia, Hall,

P. Thetis, Hall.

P. trig-onalis, Hall,

P. Vanuxemi, Hall,

PLATE AKD FIGURE.

150 LXXXV, fig. 37.

147 LXXXV, figs. 38, 39.

129 XXIII, figs. 12, 14.

131 XXIIL figs. 17-20.

132 XXIII, figs. 16, 23 ; LXXXV, fig

130 XXIII. fig. 13 ; LXXXV, fig. 8.
144 LXXXV, fig. 20.

137 LXXXV, fig. 19.

148 LXXXV, tigs. 32, 33.
135 LXXXV, tigs. 1^.
140 LXXXV, tigs. 34, 35.

151 LXXXV, fig. 36.

i. 14-18.

Sang-uinolites, McCoy.
S. ? subtruncatus, n. sp.,
S. t undulatus. Hall,

1844.

508 LXIV, figs. 3, 4.
508 LXIV, figs. 1, 2.

Scllizodus, King. 1844.

8. a>qualis, n. sp.,

8. appi-essus, Conrad,

8. Chemungensis, Conrad, .

8. Chemungensis, var. quadi'

i-is. Hall,
8. contractus, n. sp .
8. cunei«. Hall, .
8. degener, n. sp.,
8. ellipticus. Hall,
8. erainens, n. sp., .
8. t fissa. Hall, .
8. gi-egariu8. Hall, .
8. oblatus. Hall, .
8. patulua, n. sp., .
8. rhonil>eu8. Hall,
8. tumidus. Hall, .

Soleinya, Lamai-ck. 1818.
JANEJA, King. 18.50
8. (J.) vetusta. Meek,

gula-

4i)9 LXXV, fig. 35 ; XCV, fig. 29.

449 LXXV, figs. 3-9.

453 LXXV, figs. 37-40, 45, 41 ?

454 LXXV, figs. 31-34, 36.

451 LXXV, figs. 27, 28.
458 LXXV, figs. 29, 30 ?

456 LXIII, fig. 17.

450 LXXV, figs. 13-15.

457 XCV, fig. 28.

447 LXXII, figs. 35-41.

452 LXXV, figs. 16-18 ; XCV, fig. 27.

455 LXXV, figs. 43, 44.
457 LXIII, tig. 20.

452 LXXV, tigs. 19-23.

448 LXXV, figs. 1, 2.

463 XLVII, figs. .53-55 ; XCIV, fig. 10.

Solen, s. g. PAL^,080LEN,v.s.a.
8. (P.) siliquoidea. Hall, .

483 LXXVIII, fig. 33.

SpatlieHa. hov. gkh.

S. tjpica, n. sp 407 LXVI, figs. 36-40.

8. ventricoea, White and Whitfield, 408 LXVI, figs. 41, 42.

Splienotiis, NOV. GKN.

8. .^olus. Hall, .

8. artiefoi-inis. Hall,

8. ? ai-cuatus, n. sp.,

8. clavulus. Hall, .

8. contractus. Hall.

S cuneattis, Conrad,

8. flaviius. Hall, .

8. rigidus. White and Whitfipld,

8. signatus, n. sp.,

8. solenoides. Hall,

8. subtortuosus, Hall,

404
395
400
401
399
396
403
402
405
398
397

LXVI, figs. 31-35.

LXV, figs. 7-11 ; LXVI, tig. 43?

LXVI, fig. 18.

LXVL figs. 2, 20-26.

LXVI, figs. 1, 3-9, 11-13, 15 (10, 16, 17, 19?) ; XCIV, fig. 2.

LXV, tigs. 12-17.

LXVI, figs. 27-29.

LXVI. fig. 14.

XCIV, fig. 3.

LXV, tigs. 21-29.

LXV, figs. 18, 19.

552 PALEONTOLOGY OF NEW YORK.

ALPHABETICAL ARRANGEMENT— Continued.

HAJO. PA.QS. PLATB AKD FIQURB.

Sphenotua Telamon, n. sp., . . 406 XCIV, fij?. 1.

S. triineatus, Conrad 394 LXV. fijrs. 1, 4-6.

S. (1) undatus. Hall, ... 506 LXXX, fig. 6.

8. valvulus. Hall 403 LXVI, tig. 30.

Tellinopsis, Hall. 1870.

T. subemaiginata, Conrad, . . 464 LXXVI, &gs. 21-31.

INDEX

TO GENERA AND SPECIES DESCRIBED OR NOTICED IN PALEON-
TOLOGY OF NEW YORK, VOLUME V, PART L

[ The heavy-faced numbers indicate a description of a genus or species. ]
[The numerals in parenthesis, (xii,) (xiii,) (xiv,) have reference to the Synopsis of Genera in the first

part of this volume.]

Actinodetma cruci/orme, (Conrad) Hall,

. (xiii)

1.^3

Athvris, McCoy,

A.

erectum, (Conrad) Hall, .

153

Atrypa hystrix,

ACTINOPTEBIA, Ball, . . . (xll

xvii, 36, 107,

129

Avicula, Klein, .

A.

auriculata, Ball, .

181

A.

angustiroitra, Conrad,

A.

Boydi, {Conrad) BaU, 95, 113, lU

, 117, 118, 160,

168

A.

htUa, Conrad, .

A.

decnssata. BaU, .

111,118,

160

A.

Boydii, Conrad,

A.

delta, BaU, .

. 181,

la

A.

cancellala, PhiUips, .

A.

Doris, BaU,

109

A.

Chemungensis, Conrad,

A.

epsilon, BaU, .

. 188,

1J8

A.

Chemungensis, Vanuxem

A.

eta, BaU

184,

1-26

A.

drculus. Hall,

A.

eximia, BaU, . . . .

. 107,

109

A.

circulus, Sfiumard,

A.

iota, BaU

187

A. ■

Cooperensis. Shninard,

A.

Kappa, BaU, .

188

A.

cruci/ormis, Conrad, .

A.

Itander, Hall,

109

A.

decusmta. Hall,

A.

muricata, BaU,

108

A.

erecta, Conrad,

A.

perobliqna, (Conrad) fldW,

116

A.

JUibella, Conrad, ■

A.

perstrialiK, BaU,

118, 120,

121

A.

fragilis, Hall, .

A.

pasilla, BaU,

117

A.

laevigata, de Koninck,

A.

sniidecussala, BaU, .

110, 113,

114

A.

lams, Hall,

A.

tenuistriata, BaU, .

119,

180

A

longitpina. Hall, .

A.

theta, BaU,

. 185,

127

A.

muricata, Hall,

A.

zeU, BaU

183,

125

A.

orbiculata, Hall. .

Allocardiam altcrnatam, Ball,

. expl. PI.

24

A

parilis, Conrad,

ALIX>RI81iA, xviii, XXX, xxxi, xxxiii, xxx

iy, xliii. xliv.

li

A.

pecteni/ormis, Conrad, .

Hi,

40«

A.

perobliqua, Conrad, .

A.

Bannibalauit, Sbamard,

. 378,381,

382

A.

pleuroptera, Conrad,

A.

471

A.

proiexta, Conrad,

A.

iStdgvrickiat) pleuropiitha. Meek,

471

A

quadrula, Conrad,

Ambonycuia, Ball,

252

A.

reticulata, BiHnger, .

Amniobnia, Ball, ....

iTl!

516

At

signata, Hall,

A.

Catskillensis, Fanuxem,

. Ivi,

616

A

speciosa, Hall,

Amussicu, Klein

Iviii,

lix

A.

spinigera, Conrad,

A.

aurariam.

Iviii

A.

tricostata, Vanuxem,

Anomia, L., .

54

A.

tuberculata, Conrad,

Area rottrata, Chemn.,

xvii

A.

tumida, de Koninck, .

^»«or«« n.W<st««i», Hall, .

. [ xxxli.

885

AVICULOPECTEN, McCoy, (

(XU) lix

PAGE.

28

291

. 36,

175

115

35

113, 114, 115,

116

18

as

172

lix

Ix

Ix

lix

Ix

. 153,

156

,

HI

. 153,

156

93

434

lix

168

,

179

108

42

• 1, s,

4

1,4,

98

. 113,114,116,

117

. 113, 114,

115

. 183,

184

• 113, 114,

115

114

29

. XXXV,

426

177,

180

48

. e.xpl. PI.

15

lix

1, 31, 45, 74, 90,

248

554

INDEX.

T

«OB.

PAGE.

Arlonlopenten equilateralls, Hott, .

10

Cordlolal Hero. l\n\i, .

. 418

A.

aUut, Hitll,

23

C.J

UncHcm^, (Hall) S. A. Miller, .

420

A.

altus, WkiU. .

23

C.

rR<\\Kn», (Conrad) HaU,

. 417, 421

A.

bollus, (Conrorf) Hall. .

3B, 37, 88,

B4

C.

radiant, (Hall) S. A. sillier.

422

A.

cancellatus. HaU,

IK, 18,

20

C?

radians, (Conrad) HaU,

422, 423

A.

canccllatnltiM. MeCmj. .

18

C.

retrostrinia, (t>. Buck) Keyierling.

426, 427

A.

CtiToW, {WincMh HaU, .

H9

C.

robtuta. Hall, .

. 424

A.

celsus, HnU,

as,

30

C.

Sao, Hull

4:iO

A.

Cleon, HaU

e

C.

speciota, (Hall) S. A. Miller,

. 426

A.

eoDTexog, HaU. .

»8

C.

transversa, HaU, .

429, 432

A.

Coxanas, Meet <f Worthm, .

90

C.

vrtutta, (llalDS. A. Miller,

. 427

A.

doIabrifomii», Hail,

. «6,

27

Cardiomorpha bellntula, Ha.l\,

387

A.

duplicatus. Ball,

14, 1«, 17, IM,

22

C.

concentrica. Hall,

. 373

A.

ollipticns. Halt, .

,

28

C.

cordutus, Hall,

•m

A.

cxacutus, HaU.

6, 6, 8, 10,

15

C.

£riopw. Hall, .

. 3«8

A.

ni«ciciilatu!i, Hall,

. 11,14,28,

M

C.

oblonga. Hall,

509

A.

fortnio, HaU, .

9. 11, 12, 14,

1.5

C.

ovata, Hull,

. 433

A.

Anff^to. (Hall) S. A. Miller, .

4;m

C.

radiaUt, Meek ft Worthcii,

. xxxvii, 438

A.

Halleanue. D'Orblgny,

20

C.

nitunila, Hall, .

444,456, 457

A.

Ida.1. flaU,

13, SO,

22

C.

tuborbictilarU, Hall,

393

A.

ifrnotus, HaU, .

. 33,

3!l

C.

Nuliorbicularis, S. A. MUler,

. 393

A.

innlgnis, HaU,

34,

38

C.

subt&rtilis. Hall, .

385

A

lly», HaU.

14,

20

C.

undulata, Hall,

. 385, 386

A.

lantus. HaU,

14

C.

zontUa, Hall,

373

A.

Uml/ormU. White ft Whitfield,

Ivii, lix.

Ix

fjAKDiovsis, Meek if Worthen,

zxxvll, 4.i3

A.

mucronatus, HnU,

38

<J.

radiata, Meek 4 Worthen,

. xxxvii, 433

A.

neglectus, GetnUz,

Ixi

C.

radiata, (Meek tf WoHhen) HaU,

. 433

A.

orbicularis, McCoy,

,

42

C.

robusta, (HaU) S A. MUler, .

424

A.

orbiculatus, McCoy, .

•

42

Cardium, ....

. xl

A.

Omtet. Hall,

. 11,

12

c.

Hibemicum, Sowerby,

. xxxiv

A

ornatus, HaU, .

35, 37,

38

C.

palmatum, Goldfues, .

XXXV, 426, 427

A.

patulus, HaU,

24,

26

C.

retrostriatuni, («. Buch) OeinUz,

426

A.

pecteniformis, (Conrad) HaU,

3, 4, 8. 9,

12

C.I

vetustum. Hall,

. 427

A.

Phorcu*. HaU,

10

Ch.«:nomva, .....

XXX, xxxi

A.

plenus, HaU,

21

C.

Leaven worthensis

xxxi

A.

princcps, (Conrad) HaU, xviii, 1, 5

6,8,9,11,12,

33

Chon

tes coronata, ....

281

A.

repletut. Hall, .

11,

12

C.

scituia, ....

. 302

A.

rugsfgtriatus, HaU,

14, 16, 17, 18,

19

CIMITABIA, .ffaW, . xIII, xllli, xiiv, 4S.'>

A.

Sandnskyensis, (Meek) HaU,

1,

3

C.

angu\ntii, HaU, .

. 468

A.

scabridns, HaU, . . ;

1, 7, U, 16, 18,

22

C.

elongata, (Conrad) HaU,

466

A.

•IgnatuR, HaU, .

.

29

C.

corrugata, (Conrad) HaU,

. xliii, 465

A.

aqnama, HaU,

27

C.

recnwa. (Conradi Hall, xlii, xliii.

467,468,469, 472

A.

8triatu.5, HnU, .

az, u.

30

VLivopisviiA, Meek <f Worthen,

. Ilv, S12

A.

nibcnncellatut, Hall,

18

C.

antigua. Meek,

liv

A.

tenuix. Hall. .

. 34,

39

C.

subnasula, HaU,

. liv, 512

A.

undulattu. Hall, .

72

c.

tellinifonni^s, HaU,

613

A.

undulatns, McCoy,

72

CoNOCAUUiUM, Bronn,

ZXXlT, 409

A.

Wffiehem, Meek, .

89

C.

n««>u«<um J (Conrad) Hall,

409

A.

(Crenipecten ?) incaltua, HaU.

30

C.

attenuatum, (Conrad) S. A. Miller,

409, 414

A.

(PterlDopecten ?) invalidus, HaU,

31

c.

concinnun), HaU, .

414

A.

(P. ? ) temiinalis, HaU

32

c.

cuneuB, (Conrad) HaU, x\

xiv, 409,111, 412

AXIKD8

. xxxix

c

ouneus, (ConradI .S. A. Miller, .

409

BlLOBITea, Dt Kay, .

xl,

400

c.

cuiiens, var. attenuatum, Conrad,

. 410

BT880PTBBIA, JToU,

(XlT)

2S2

c.

cuneus, var. nasutum, HaU,

410

B.

radiata, Hatt, .

202

c.

euneu.s, var. trigoriale, HaU,

. 410

Cordinta HamtttonetuU. DOrbifrny, .

359

c.

dcnttculatiiin. HnU,

.413,414, 4IS

CABDtOLA, ....

XXXV

0.

Eboraceum, HaU,

. 412, 413

C?

, Hatt, ...

420

c.

inceptum, Hnll

415

O.I

416

c.

nriilam, HaU, .

. 414

c.

DorU, Hall,

428

c.

naeutum, Hall,

40(1

C.I

elemta, Hall, .

417

c.

normale, HaU, .

xxxiv, 410, 411

c?

equilatera, HaU,.

419

c.

Ohioense, (Meek) HaU, .

411

c?

XXXT

c.

Ohioenso, Meek,

. 4U

INDEX.

655

Conocai'dinm reliqaum, Hall,

C. rugosum,

C. tcgulam, Halt,

C. trigonale, {Ball) S. A. Miller,

Crenipectex, Ball,

(xll) xvii, 1x1, IxU,31,81,
. 81,

Ixi

8I,8«, Si, 84,

amplus, Ball, .

crenulatus, BaU, .

glnber, Hall,

impolitiis, BaU,

Leon, Ball,

liratas. Ball,

microptcrus, BaU,

obsoleuis, BaU,

Winclielli. {Meek) Ball,

(Pecten) Winchelli, (Meek) Hall,
OucuUea opima, flail, .
CUJtEAMYA, .....
Ctpricardei.la, HaU,
Cyprtcardin contracta. Hall,
C. cymbifonnis, .

C 1 rAomftea, Hall,
C. 1 rtgida. White * Whitnel.l, .
Ctprioardinia, Ball,
C. consimitis, flaW,

C. crassa, ....

C. ? cylinilripa, BaU .f Whitftdd.
C. (llBlincIa, killings.

C. inrtenta, {Conrad) BaU,

C. lamellota. ....

C. plannlata (Conrad) BaU,

C. py^wMBa, (Conrad) S A. Miller,

C. Bulrireni?, BaU,

Cfpricarditet alta. Cnnrn<\,
C. anj^tistata. Vanuxem, .

C. arcuata, BaU,

C. hintlcata, Conrad,

C. carinata. Conrad, .

C. carinifiTa, Conrad,

C CatfkUlemif. Vannxom, .

C. ChemunpemU, Vnnuxom,

C. concentHca, Conrad,

C. corragata, Conrad,

C. elonffatuSfConrtu], .

C. indenta, Conrad,

C infiata. Conrad,

C MarcellensU. Vaniixem,

C. mytUoide*, Con rail,

C oblonga. Conrad,

C. planulata, ....

C. recurva, Conrad,

C. recurva, Vannxem,

C. mgota. Conrad,

C. iect{f)ron». Conrad,

C. tubalata. Conrad,

C. <n«n<vi*iu, ('onrad,

Ctthkrodom. BaU,

C. , Hall,

C. <g>pretnu, (Conrad) Hall,

C. nanntna, BaU,

C. tumidaw. Hall, .

C. (^cAtexiiM) opprMOTM. (Conrad) Hall, .

C. 18. ) CA«niun$en«<«, (Conrad) Hall,

C. (S. ;. :) cunens, BaU,

86,

.83,
Ixi,

PAGE.

415

. 41.1

415

409,410, 411

90

83

86

85

83

88

87

87

84

89

8U

. Sl.'>

. xxxii

. XXV, 307

xxiil, 399, 402

. xxiv

452

. 402

xItI, 484

. 486

xlvii

. 486

xlvii

485,486, 487

xlvi, xlvii

. 484

514

. 487

278

. .MB

486

. S-W

301

. 3<B

516

301-303

'.£75

. 4(B

466

4S5

48.')

435

278

27.')

xlvii

467

467

297

475

283

394

511

511

. 449

liU, 511

. 448

449

. i!i3

451, 468

xlvii

277,

xliv.

■ill.

PAGE.

Cytherodon{Schizodus)ellipticut,H!i\], . 450

C. (5. ) gregarius. Hall, ... 452

C. {S. )nasutus. Hall, . .611

C. (S. ) oblatus, BaU, ... 465

C (5. ) pauper. Hall 446

C. (S. ) qiiadrangularis, BaU, 464, 459

C. (5. )rAom*e«», Hall, . . .452

C. tS. ) tumiduB, Hall, ... 448
Dkxiobia, . . xxxvii

D. ovata, Winckdl, ..... 433
DualiNA, Barramle, . . . . x:
DYsrACit.iA.k, Ball <f Whitfletd,
D. subiiasuta, (Hall & Whittteld) S. .\. Miller

D. ieUini/ormia, HaU, ....
E<;hinocarLs socialis, Beecher, .....
Ectenodesma, Ball, .... (XlT)

E. birostratum, Ball, .....
KvyiOSVI \, DeKoninck, . . xxxH, 386, 393,
E.
E.
E.
E.

liv.

433
liv
612
613
478
242
ii4%
507
depressa, HaU, .... 391, 393

ellipsis, HaU 392

Burlingtonensis, White (f Whitfield, . 390

liurlingtonensis, (JTWie tf Whitfield) HaU, 387, 388

389, 390, 392
388
xxjtii, 386, 387, 388, 389, 390, 392
386

E. obliqua, BaU,

E. Philipi, Ball, .

E. rhomboidea. Ball,

E. siibcarinata, Ball,

E. subnasuta. Hall,

E. subovata, Hall,

E. 1 tapesiformii, M< rk ,

E. tcnuistriata, Ball,

E. transversa, Ball,

E. undata. Hall,

E. undulata. BaU,

El,YMELl,A, Hall,

E. fabalis, BaU, .

E. levata, HaU,

E. nuculoi'les, Ball,

E. patuln, Hall,
ENTOLit;M, Meek,

Ivii,

E. aurariuin. Meek,

E. avii'ula. Swallow,

E. aviculatum. Swallow,

E. Cooperensis, SAumard,

E. demissuni, ....

E. Shnmardianum, Winchelli .

EoDON. Ball, .....

E. beltistriatus, (Conrad) S. A. Miller

EUCHONDKIA, Meek,

E. ncglecta, Meek,

EUTHYDFSMA, BaU

E. subtextile, BaU,

GlXJSSITES, BaU, ....

G. amygdalinus, ( Winchell) BaU,

G. depressa.-. Ball,

G. ellii>ticus,

G. lingualis, Hall, . xlix, 1,

G. patulus, Halt, .

G. procerus, HaU,

G. rudicula. Hall. .

G. subnasiUus, BaU, .

G. subtenuis. Ball,

G. toretts, HaU,

. expl. PI. 64

. 607

xxxii, 389, 391

. 391

393

. 380

379

. 508

. 1, 603

1, 602, 504

604

1, 503, .'>0.5

504, S05

Iviii, lix, Ix, 81

Iviii, Ix

. lix

Iviii

. lix

Iviii

. lix

XXV, 307

. 308

Ixli

. Ixii

xxxii, 335

xxxii, 385

xlix, 404

49.'), 501

496, 497, 499, 502

I, 498

495,496,497, 600

. 501

499

. 498

60O

. 495

. 1, 494

556

INDEX.

PAGE

PAGE.

Gltttucardia, BaU, .

. -XTil, XXXT, 4-.'6

Grammysia (I.«pto(lonius ?) praerursor.

BaU, . 876

G.

spociosa, Alii,

XXXV, 4«0

0.

{LI ) tubarcuata. Hall,

375

GLTPTODESMA, BaU, .

(xUI) xvii, l.Vt, lti.1

G.

(Spbcnomya), cuneata, BaU,

xxxii, 388

G.

erectum, (Conrad) BaU, .

1S3, 187

Biatella mlcata, Fleming, .

. xxxii

Q.

erectum, var. obliquum. Hall

. IBS, 1S6

ilyolith08 uclis, ....

. 302

o.

oeoidentale, BaU,

187

luoceramm Chemungentii, Conrad,

268

GONIOPHOBA. PkOUpt,

. xxill, 29 !

/.

oviformit, Conrad,

. 255

G.

acuta, BaU, .

2<Jf, ao6

Jankia. King,

xli, 463

a.?

alau. BaU.

. !J94

Janira longicauda, [DOrbigny],

48

o.

rarinnla, Batt,

301, 304, SO,')

Lkda

Schumacher, xxtII, xxvlii, 329, 332

G.

Cheniunirensis, ( Vanuxem) BaU, SOi, 303, SU4, 805

L.

BarrUi. White & Whitlleld.

347

a.

CYmb{ft>rmit. Sowcrby,

xxiv

LI

brevirostria. Hall,

. 320

a.

glabra, S. A MUUr. .

. 299, SOi

L.

brevirnstris, HaU.

xxvi;, 320

G.

Glnucus, BaU,

xxiv, !899, 302

L.

curln, Afeek.

. 331

G.

HamiltonenKi8, BaU, .

206, SOU, 302, SKI

T,.

divcisa, BiM,

. 320,331, 832

G.

Wn.BaU. .

300

L.

nuculiformU, Stevens,

347, 348

G.

minor, BaU,

. 30S

L.

obscura, BaU,

331

G

peran^lata, BaU,

xxiv, 203, «P9

L.

pandoiiformis, Stevens,

xxvii, 332

G.

rugosa, Conrad,

. 297, 3(h!

L

porstriata, .

331

G

subiecta. BaU,

304

L. ?

rostellata, (Conrad) Baa, .

. 330

G.

trigona, BaU, .

. 302

1-.

rostcllata, BaU. .

xxvii, 330, 8.31

G.

truncata, BaU,

29(, 290, 208, 301, 3U6

L.

{Nuculana) brevirottris. Hall,

. 329

GOSSKLETTIA, Barroit,

(XlT)2«3, 2H6

L.

{N. ) curta. Hall, .

331

G.

retnsa, BaU,

266

L.

{N. )diversa, llnW, .

. 3-29

G

triqaetra, (Conrad) BaU,

. 26S, 266

L.

(JV. ) OhioentU, Hall,

332

Grammysia, De yemaiU, xviii, xxx.

xxxi, xxxii, xliii, xliv

L

(JV. )per8triata,Ui\U,

. 330

li, lit, 368, 507

L.

(AT. ) ro«<e«o«o, (Conrad)

Hall, 3:<0

G.

alveata, {Conrad) BaU,

xxxi. 370, 371, 374

Leioptebia, Batt,

(xlll) xvli, 129, 188

G.

arrnala, [Conrad) BaU, . 370

372, 373, 375, 376, 377

L.

Bigsliyi, BaU,

. 168,167, 510

G.

bellatula. BaU,

. 367, 373

L.

Cliemunpensirt, ( Vanuxem) BaU

. 172, 174

G

bbulcata, iConrad) BaU,

. xxxi, 3.58, 380, 361

L.

Conradi, BaU,

. 160, 160, 165

G

Canadensis. ISiUings,

. .^TO

L.

Dekayi, BaU, .

164, 172, 173

G.

circularis, HaU,

364, 36C, .•i67, 369

L.

Gabbi, Ball.

160

G.

commanis, BaU,

xxxi, 378, 380, SSI

I..

Greeni.BaU, .

. 160, I6B

G.

constricta, BaU, .

377

L.

lasvis, BaU, . . . .

168

O.

donaci/ormis. Hall, .

. S7S

L.

Lcai, fln«.

. 168

G.

dnplicata, BaU,

380

L.

lin^uiformin, BaU,

173

G.

elliptica. BaU,

360,368,366, S61

L.

Mitcholli, BaU,

. 166

G.

erccta, BaU,

363

L.

nUida, Hall.

172

G.

EriopiH. BaU, .

. 368

L.

Oweni, BaU, .

. 170

G

glabra, BnU,

369, S<I7

L.

RaHncsqtiii, Bait, .

. l«l,lft'>, 186

G.

globosa. BaU, .

. 372

L.

Sayl, BaU.

. 162, 171

a.

BamUtonmtU, De Vernenil,

XTI. SRB

L.

Torreyi, B€Ul.

174

G.

HannibalenBis, {Shumard) Ba I. . 378. 381. 382. 38.1

L.

Troosti, BaU, .

. 167

o.

lirata, HaU.

.370, 371
. 362, 36!

LEITODESMA, BoU. . (Xlil) XVii,

Kix, 129, 176, 234, 239

G.

magna, HaU, .

L.

acutirostriim. Ball,

234

G.

nodocostaia, BaU,

. 360, .382, ,36;i

L.

Agassizi, Ball, .

. 182

G

obsoleta, BaU,

xxxi, 366, 3(18, 369

L.

alalum. Ball,

218

G

ovala. BaU,

368

L.

all forme, BaU. .

. 220

a.

paraUela. Hall,

470

L.

arciforme, Ball, .

220, 231

G.

plena, HaU,

nao

L.

avifonne, Ball.

. 224

G.

G.

O.

G?

G

G.

G.

pncanoT, BaU, 376,377, 3M
secuncla, BaU. ..... 379

subarcaata. flrtU, 37B,878, 382
snbna.-'iita, Batt, ..... 807

undata, BaU ' g^^

zonata, BaU ' 373

(Allorisma) Hannlbalenslg, Shumard, . . 379

L.
L.
L
L.

I..
L.
L.

liecki, BaU.
Billingsi, BaU.
Biton, fli/«,
Cadmus, BaU, .
Clitus, BaU,
complanatum, BaU, .
Corydon, BaU.
Creon, Ball.

188

. 102

222

. 201

210, 212

22c, 227

212, 216

202, 201, 205

O.

lleptodomtu) arcuata, (Conra<

1) Hall, S73

L.

eurvatuni, BaU.

106

a.

(L.? ) con»tiicta, BaU

. S77

L.

Hem us, BaU.

. 203, 205

Q.

iL.? ) Hannibalensis,

Shmnard) BaU, SIS

L.

disparile, BaU,

186

381, 882

L.

extenuatnm, .ffoU, . . 207,210,211,214, 211

INDEX.

557

X^ptodesma flaccitlutn, Hall^

I>. Hector, Ball, .

L. Jason, Hall,

L. lepidnm, ffall, .

L. Lesley!, Hall,

L. Lichas, Halt,

L. longispinum, Hall,

L. Loxia«, Hall, .

1j. Lysanfler, Hall, .

L. 3faclurii, Hall, ,

L. Marcellense, ffall,

h. Mathcii, ffall, .

L. Medon, ffall,

I>. Mentor, ffall, .

L. . Moi'toni, ffall,

Jj. mytiHfornie, ffall,

L. naviforme, Hall, .

L. Nereus, ffall, .

L. Orcus, ffall,

L. Orodes, Ball, .

L. Orus, fliia, .

L. patuIuin,/7aU, .

L. Pclops, ffall,

h. Phaon, ffall, .

L. potens, ffall,

L. potens, var, jiivens. Hall,

L. propin(|aum. Hail,

L. protextum, {Conrad) Ball,

L. qnadratnm. Hail, .

L. robuetum, ffaii, .

L. RoKersi, Hail,

I,. nido, fl<i«,

L. Shumardi, floH, .

L. sociale. Hail, .

L. splnlgernm, (Connul) floK,

L. Stephani, Hall,

L. truncatam. Ball, .

L. umbonatnn), ^oU,

L. nmbonatam, var. depressum

£<Ma fflalier, HaU,

£. a>aerofi<<ra, Conrad

£. r obtoUla, Hall, .

£. rugatiriata. Hall, .

IjImoptkra, ^nU,

PAGE.

826, 227

196, a09, 213

313

. 195, 197

233

204, 230, 333, 234

179,181,182,184,191, 192

. 204

. 215, 216, 218

207, 223, 338

176

. 193, 194

197

. 305,

. 182, 189,

315,
306, 214, 223,

236
190
335
300
317
218
235
219
336
■225
234

L. canrcllntn, Ball, .

L. caneellaia, var. oceidetu, H. A. W.,

L. curvata, Ball,

Ij. macroplen, I Conrad) Ball,

L. obsoleta. Ball,

L. paaperata, ffall,
LrciNA, . . . • •

1j. lineata, OoUHfutt, ■ .-

Iv. proavia. GoldfUsa. . . . . -

L. iParacycUu) elliptiea, v.nr occidentalu. Hall &
Whilflcld, . . 440,

L. [P. IZirnte, (Conrad) Hall &Wliitfleld, .

L. {P. ) Ohioemit, Meek

. 214, 220,

. 230,

188, 190, 193, 198, 199

. 189

331

. 183, 496

233

181, 185, 189, 191, 193, 198, 199

176, 178, 179, 187

. 221

180, 191

. 187

177,183, 184

. 194

211

. 198

203

ai

251

84

15

(xllil 243

244

. 244

250, 251

244, 246, 250

243. 249

. 243

xxxix

. 442

HaU, 199, 200, 202,

. Ilx,

246,

lix,

440

LtrutfLiCARDiim, Uuiuter,

£. aeuiirostrum. Hall,

L, cortum. Hall, .

J,. fragile, BtM,

\j. Marcellense, ( Vonuxem) Ball,

L. orblcalare. Ball, .

441

441

442

xvli, xxxvi, xzxvlil, 434

4:i7

. xxxTiii, 436, 437

. xxxviii, 434

. 439

436, 438

Lunulicardium omatuml Hull

L. ornntuni. Hall.

L. rude. Hall,

Ij. transveisam, Hall,

Lyriopectex, Hall, .

L. anomi.T?formis. HaU,

L. cymbaloil. Hall,

L. Dnrdanus, Hall,

T.. fasciatus, Hall,

L. interradiatus, ffall,

L. macrodontus. Hall,

L. magniflcus, ffall, .

L. orbiculatus, HaU,

L. parallelodontus, HaU,

L. Polydorus, Hall,

L. Priamus, Hall,

L. solox. Hall,

L. tricostatus, ( Vanuxem) Hall,

Macrodon, Lycett,

M. Chemungensis, HaU,

M. Hamiltonix, Hall,

M. ovatus, Hall, . .

PAGE.
. 4.i6
438, 437
. 435, 4.'i7
. xxxviii, 439
. (Xll)2, 40, 74
53
45, 47, 60
41
. 66
44, ,50
43, 45, 46, 48, 50, .W, 55, 57
45, 47, 48, .50, 51, .57
41, 43, 81
40, 42
45, 60, 57
43, .50, 54, 56
. 45, 51, 56
47, 48, 51
. XXTiii, 349, 407
xxviii, 360
xxviii, 349, 351
. 361

M. parvus. White (f Whitfield, ... 351

Margabon, . . . Ivi

Megambonia, Ball, .... Iv, 515

M. bellistriata, ..... Iv, 515

M. cardiiforniis, BaU, Iv, 616

M.? laniellosa, . . . . . Iv

M. Lyoni, BaU, ..... 433

M. subcardiiformis, (Hall) 8 A. Miller, . B15

Meristina, Ball, ...... 28

MiCRODON, Conrad, .... xxv, 307, 312

M. bellistriatus, .... 310, 311

M.1 complanatus. Hall, .311

M. complanatus, ..... 309

M. Rregarius 309

M. reservntus. Hall, ..... sig

M. lenuistriatns, .... 310, 312, 313

M. (Cypricardella) bellistriatus. Hall, 308

M. (C. ) complanatus, Hall, . 311

M. (C. ) grcgarius. Ball, 309

M. (C. ) major. Ball, . . 307

M. (C. ) tenuistrialus. Hall, . xxv, 310

M. IMicrodonella) [Eo(lon)beUistriatusAConr.)UnU, 308

^f (if. )(E. ) complanatus, Ua\], . 311

M. tU. ) (E. ) gregarius. Hall, . . 809

if. Of. ) (E. ) tenuistrialus. Hall, . 310

Microdonella, (Ehlert, .... xxv, 307

M. bellistriata, (Conrad) Qj^lilert, . xxv, 308

M. complanata, ...... 307

M. gregaria. Hall, ..... 309

if. tenuistriata, Hall, ..... 310

Modieli.a, Ball, ..... iiv, 514

M. pyi^msna, [Conrad) Ball, . Iiv, Iv, 514

MODloi.A, Lamarck, . (xiv) Iv, 175, 236, 267, 614

M. angn.sta, Dana, ..... 516

M. concentrica, (Conrad) .ffoU, ... 275

if. metella. Hall, . . . " . . .266

if. pracedens. Hall, ... 267, 268

M. (Mytilops) metella, fliiK, . .368

M. (M. ) prtecedcns, HaU, 367

Modiolopsis perovata. Meek if Worthen, . 273

JIoDIOMORPiIA, BaU, xxiii, xxiv, 1, 176, 234, 269, 272, 293, 352

71

558

INDEX.

M

H.

M.

U

M.

H.

U.

iff

H.

H

M.

M

M

H.

H.

II

M?

it.

U.

u.

H.
M
M.
M.
If.
M.
H.
M.
K.

mUer,

PAOE.
Modlomorpha afflnlx. Bait, ..... M4
M. ulla. ^CoHrad) HnU. 274, 276, 277, »78, 280, «4, «5

irr am^gdaibia, IWinchcll) H»ll. 291. 495, 496, 497, 501

angastaU, ( Vanuxem) S A.

arouata. Ball, .

Catskillcnsis, Vunuxem,

Clarens, Ball, .

complanata, Ball,

conoentrica, (Conrtut\ Ball,

cj'mbula. Ball,

h^tdta. Hall,
hyalea. Ball. .
linfruirormis. Ball,
macilenta, BaU,
mytiloides, Ball, .

neglecta, Ball,
peroTBla, [Jteek ^ WotHien)
perovata. Ball,
planulata. Hall, .
ponderosa, BaU,
pondtroM, Hall, .
putlllns. Ban, ,
quadmla. Ball,
recta. Ball,
recarva, BaU,
retrnlaris,
riglda, BaU,
Schoharie, Ball,
subalatn, iConrad) Ball,

516
. 881

51«

270, 873
270, 878,274, 277

xxiii, a7«, 277, 2S1
275, 888
. 292, 502, 60S
. 808
874, 28^;
. 27S, 274, 279, 28(1
xxiil, 870, 274, S78, 877, 279, 280
285, 292

271, 890
BaU, . 272,273, 274

. 273

277

. 871

271

. 871

889

. 886

388

. 870, 282

284, 887

869,270,274, 275

883,286,287,288, 289

subalata, rar. Cheniunfrensls, Ball,

sobangulata, Batt,

Tlcign, BaU, ....

884,288, 291

287

. 291, 29;1

MOHOMTARIA, ...... xvii

MONOTIS, . .425

M. elevata, Conrad, .... 417, 425

jr. PouUonI, Conrad, . .425

Jf. prineepi, Conrad, . 1, 4

M. radians, (Conrad) S. A. MUUr, .422

MrA, ....... xxxi

MtTILARCA, HiiB, (xlT) 253, 262, 266

Jr. arenaeea. Hall, ..... 2.^t

H. attennatA, Batt, ..... 200

M. carinata. Ball, .... 2.58, 869, 2fil

Chemun(cen8ii». ( C'onr. ) B , 2.57. 2158, 2.59, 261 , 262, 2W
fibristriata. I IThUe <f WhUJIeld) BaU, . 264

gibbooa, Batt, ..... 868

lata, Batt, ...... 868

occldentalis, ( Whit* <f WhUfield) BaU, 259, 863, 264

U.
M.
M.
H.
H.

jr.
jr.

M.
JT
M
M

jr

H.
M.

jr.

M.
M.
H.
M.

ovIformU, (Conrad) Hall, . . . 2.^5

ponderosa. Hall, ..... 264
prramidata, Batt, ..... 856
radiata. Hall, ..... 2.52

reKularis, Batt, . 860, 262, 283

simplex, Batt, ..... 861
triquettr. (Conrad) Ifall, .265

nmbonata, BaU, ..... 857
(Plethomytilns) arenaeea, Batt, . . 853, 2.54

iP. ) eordiformU, Hall, 254

(P. ) Knappi, Batt, . . . 856

(P. ) mytilimera, Conrad, . 2.54

(P. ) orata, BaU, .254

(P. ) OTlfonnls, Boa, . 866, 250, 26S

PAGE.

Mytllarca (Plethomytilas) ponderasa, BaU, . 854,

255

MVTII,<)P8, BaU, ....

(xlT) 282,

267

jr

[Uodiola ) Joto, Hall, .

282

if.

(jr. ) metella. Hall, .

268

if.

(jr. )prcKedent, Hall,

267

u.

(jr. ) tlmplex. Hall, .

,

261

Myth

us

. 176,

238

jr.

ChemutigemU. (Conrad) Phillips A Salter, .

2.58

jr.

fibrUtrintiu. White* Whitfield,

261

jr.

occidentalit. White & Whitfield,

263

jr.

WhUAeMianu; Winchell, .

264

Neilo

, .....

. xxvlil

NUCULA, Lamarck. . xxtI, xx^

II, xxTiil,8l3,

451

N.

bcllatuin, BaU,

.333

N.

bollistriata, ( Conrad) BaU, 314, 317, 318, 319, 323,

3.33

N.

cingulata, BUinger,

359

N.

corbuliforniis, BaU, .

319

N.

diffidcns, Batt,

328

N.

globularls, BaU,

383

N.

Honghtoni, Steven*,

383

N.

Bvbbardi, Winchell, .

347

If.

louitmU, Hall,

323

N.

lowenHs, White & Whitfleld,

323

N.

lamcllata, BaU,

xxvl.

380

N.

levata, ....

314

N.

lineata, PhUUpt, .

316

If.

2tnea<ar (Phillips) Hall,

316

•s.

lirata, (Conrndl »i«.

. 316, 316,

321

N.

Neda, BaU <f WhU/tdd,

314

N.

nlotica. BaU cf Whitfield,

313

If.1

oblonga. Hall, .

324

N.

Randalli, fliiZi, xxvl, 315, 317, S18.322,

324

N.

subelllptica. Ball,

.

317

N.

umbonfctJi, Ball, .

381

N.

vuricosa, BaU, . xxvl,

318, 319. 320,

327

N.

(Nnculites) ovata, Sowerby,

325

NncuLiTBS, Conrad, .

. XXTl, xlii,

324

N.

appretaa. Conrad, ,

449

y.

hellUlriata, Conrad, .

318

y.

Chemungen»i». Conrad, .

463

y.

conttricta. Conrad,

xxvii.

333

s.

ouneiforrais, Conrad,

XX vi.

325

y.

emarginata, Conrad, .

338

y.

fllota, Conrad,

.

343

y.

lirata, Conrad,

.

316

y.

maxima, Conrad, .

3.35

N.

Nyssa

. 827.

328

y.

oblongata, Conrad,

324

y.

oblongata, (Conrad) Hall,

324

N.

oblonRatas, BaU, .

xxvl, xxvii,

384

y.

radiata, Conrad,

46»

y.

roitettata, Conrad,

330

y.

tuhemarginata, Conrad,

. xlii.

464

y.

mlcatina, Conrad,

347,

348

N.

triqueter, Conrad,

. xxvii, 320,

3'S

NTA88A, BaU JCXll, 352, 354,

353

N.

ar^ta, BaU, .

. xxlx, 354,

357

N.

elllptica, Batt,

,

367

N.

recta, BaU,

. 3.55,

356

N.

subalata, BaU,

xxix,

365

' Orthis impressa,

2»1

O.

Tioga

.

496

j Obthomota, Conrad, . xxx, xxxl, xlll.

XlT. 478, 482,

483

INDEX.

559

OrthODOta carinatA, Conrad^*.

cingulata, Hisinger,
ensifoimis, Hall,
extrasulcata, Salter,
parvula. Hall, .
parvula. Ball,
pholailis, Conrad,
rigiila, HaU,
siligvoidta. Hall,
triangulaCa, Sailer,
anilalata, Conrad,
ventricofa. White & Whitflelil

O.
O.

o.

o.

o.?

o.

o.

o.

o.

o.

o.

Pal^asatina, Sail, .
P. anguata, Mall,

P. guadrata. Hall,

P. 8inaala, Hall,

P. 80lenoiiles, HaU,

P. typa, HaU, .

PALAioMTA, ZUtel4 Goulert,
Pai.a;oNkii,o, HaU,

P.

P.

P.

P.

P.

P.

P.

P.

P.?

P.

P.

P.

P.

P.

P.

P.I

P.

P.

P.

P.

P.

P.

Z PAOB.

xlvi, 479, 481, 482

xxxi

. 480

xxxi

. 482

48S

. xlT, 479

481

. xlvi, 483

xxxi

xlv, xlvi, 478, 480, 481, 482

4U8

XlTil, 488

490

xlviii, 492

491

xlviii, 489

xlvii, xlviii, 4188, 489, 490

. lii

xxTll, 324, SW, 333

. 344

341

xxviii, 346, 348

anguBta, HaU, .

arata, HaU, ....

attenaata, HaU,

farrin, (White ft Wliitacld) Hall, . 347

bisulcata, HaU, ..... 344

brevis, BaU 348

coaatricta, {Conrad) HaU, . xxviii, 333, 335, 342
constricta, var. flexuoda, (Com-., sp.) HaU, var., 334

dubia, BaU 348

eloDKata, HaU, .... 346, 346
emarpnata, (Conrad) HaU, . . 338, 345

fecanda, AiU, xxviii, 336, 337, 338, 340, 341, 313

fliosa, {Conrad) HaU. .... 343

maxima, {Conrad) HaU, . . 331, 339

routa, HaU, . 337, 338, 340, 344, 347

perplana. Hall,

pcrptana, HaU,

plana, HaU,

sulcatina, {Conrad) HaU,

tcnuiHtriata, BaU,

Iruncata, BaU,

virKiui<'a, HaU,
Paljcupinna, HaU,
P. nabella, HaU,

P. recurva, BaU, .

PAl.f080i.KM, BaU,
P. biliquoiilea, HaU,

Panekka, Barrande,

P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.

ahiapla, HaU, .
alternata, HaU,
contata, BaU, .
degener, BaU,
dichotoma. Ball,
elevata,

equilatera. BaU,
tlevn, BaU, .
I.incklaMii, BaU,
mollis. Ball,
multiradiata, BaU
potent, BaU,
Poulnoni,
radians, BaU,
retusa, BaU,

339

339, 31U, 311

334

. 347

336,338, Ml

. 347

340

. (xlv) 240

.* 840

. 241

XlTl, 483

. xlvi, 483

xvii, XXXV, xxxvi, 41)i, 429

. 423

416

. 419

424

. 416

425

. XXXV, 419, 424

418,419, 420

. XXXT, 420, 4-23

420

XXXV, 417

422, 423

.425

XXXV, 422, 4-26

. 421

Panenka robnsta, Hatt,

P. ventricosa, BaU,

Panop^a,

Pakacardidm, Barrande,

P. Doris, HaU, .

PakacyclaS, Ball,

P. Chemungensis, HaU,

P.l elevata. Hall, .

P. elliptica, HaU,

P. erocta, Hall,

P.J fissa. Hall, .

P. ignota. Hall,

V. lirata, {Conrad) HaU,

P. Oliioensis, BaU,

P.? pauper, HaU,

V. rotunda, HaiU, .

P. tenuis, BaU,

1'AHARCA, Bdtt, .

P. erecta, B<Ul,

P. neglecta, BaU, .

V. praece'iens, BaU,

P. Sao, BaU,

P. transversa, BaU,

I*. venusta, HaU, .

I'ECTEN,

I*. aviculatus, Swallow, .

P. aviculus. Swallow,

P. cancellatus. Hall,

P.I coHvexua, Hall,

P.J crenulatus. Hall,

1*. demiseus, PhUlips,

P. densistria, Sandb.,

P.l dolabri/ormu. Hall,

P. duplicatut, Hall,

/'. Balleanua, D'Orbignj',

P. neglectui, Geinitz,

P. striatua. Hall,

/'. subobsoletus, D'Orbigny,

P. Trauquebaricus, Gmelin,

I'. undulatus, McCoy,

I'ERNA, .....

I'EBNOPECTEN, fFincheU, (xll) ItII, Iviii

P. Cooperensis,

1*. crenulatus, BaU,

P. /asciculatus. Hall, .

v. glaber, BaU,

1'. limatus, WincheU, . . .

V. limiformis, Wlute ^ Whitfield,

1*. ob.soletus, HuU,

P. Shumardianus, WincheU,

I'HOLADELLA, HaU,

p. constricia. Hall,

/'. cuncita. Hall,

P. decussaia, Hall,

I*. Newberryl, BaU, .

P. OTTuUa, Hall, .

P. parallela, BaU,

P. radiata, {Conrail) BaU,

P. truncata. Hall,

Pholadomya anomala, Goldfilss,

PUTIIONIA, Hall, ....

P. cylindrical Ball,

P. lirata, HaU,

PAGE.
416, 424
. 417
.510
xxxTl, 428
.xxxvi, 428
XXXTlli, 410, 415, 44R
443, 444
. 447
. xxxviii, x.xxix, 440, 444
. 445
447
. 444
xxxix, 302, 441, 442
. 442
446
. 444
xx.xi.x, 443
XXX Tl, 429
xxxvi, xxxvii, 429, 432
429, 432
429
. xxxvii, 429, 430,
. 429, 431,
xxxvi, xxxvii, 429, 431,
Ivii,

Iviii,

Ix, Ixi, Ixii,

Ix,

lix,
Ivii,

431
432
433
lix
Iviii
lix
18
28
82
Ix
lix
26
17
18
Ixii
22
lix
48
72
Ivii
81
ix
ix
56
ix
Ix
Ix
Ix
Ix

Ivii, lix,

xliU, xliv, 469

. 377

510

. 610

xliii, xliv, 471

4«9, 470

470

-xliv, 469, 471

469, 470

. 359

ZllT, 473

. xliv, 473
476

660

INDEX.

riiUinnia nitiila, natl. .
I*. nodtrostHM, //«//, .

P. set'lifroiis, (Conrad) /loll.

P. trunoata, Hall,

PUYLLOCAKIDA,

PiHHoptU actitirotira. Hall,

/'. oriuitut. Hall, .

Plktiiuuytili'S, Hall,

P. ponderotut. Hall,

Pltarorhyncliut atteituntut, Coninil,

P. cuneut, Conrad,

P. trigoniUia, Hall,

Potitionia alvetita, i^t>\\ri\'\,

P.I arduita^ Conrad, -

P. liraia, Conrad,

P. tdlinoides, Conrad,

PRJkCAItUIUU, Barrandt,

V. deapectum, Ilarrandf,

P. \eluitum. Sail,

Pro<lucU:llu Uoydi, .

PROUACitus, Meek,

P. Amlrewtki, Meek,

I*. cuneatu.-s, Hall,

P. Ml^»uurieusi», Steallow,

PKUKurNciii's, Hall, .

P. anj^ulatuni. Hall, .

1'. nasutum, H<iU,

P. quadraluni, Hall, .

PUUTHYK18, Meet,

v. alala. Hall, .

1*. elej^ans, Metk,

1'. exula, Hall, .

P. laiiueolata. Hall,

P. planulala. Hall,

PUUTUMVA, /foU,

P. oblonga. Hall,

Ptkkixka, OoUifuM, .

P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.
P.

P.
V.
P.
P
/'.
P
/'.
P.
P
P.

. xli\ , 473, 474,
xliv, 47a, 475, 477,

(xU

avi*. Hall, .

Iii.-'ulcala, Conrad,

Boydi, Conra<l,

carili/ormu, llall,

Clienuni|jfc>n»i8, {Conrad) Hall,

concenlrica, Conrad, .

coiLsiuiiliM, Hall,

costulata, Uoemer,

euneata, Conrad, .

<Urtpanda, Hall,

faiH'.tctilata, Ooldfutt,

llaliella, Hall, .

KnmdU, Hall,

inlcrstrialis, Hall,

longitpina, (Hall) S. A. Miller,

|>in>;uis. Hall, .

pUiualata, Conrad,

prora. Hall,

prottxta, (Conrad) S A. Miller,

punctulaia, ConratI, .

pygmaa, Conrad, .

railianM, Conrad,

reprobut, llall,

retwr«a, llall, .

rcrCTM, var. avi$. Hall, .

rigida, RttU,

PAGE.
. 477

47.'>

478

476

. 478
437

. 4S7

(xiT) ■ua

. SM

40J

. 4(W

409

. S70

37S

. 441

4<.4

xsxvl, 4-27

4J7

. 4«7

291

Hi, SIU

lii

lii, 610

lii, 510

Xlvlll, 4».>

xlix, 403

. xlix, 403

xlix, 494

xl, 46U, mi

xli, 4«1
xl, 4tiO

xli, 4«0, 4(!J

xli, 460

III, Mt

Hi, 509

cix, lix,'i, 91

1U3, lu7

. XXX, 3.i9

113

. 51.5

■02

•273

100

93

1)5, 98, lUI,
. xxiii,

99,

vli,9l.

9-2, 93, 97,

91,
102, 104, 105,

42-2,
104,

97

93
98
01
96
179
Wt
481
107
183
467
614
425
72
105
105
101

IHtrineat tuborbicularit. Hall, .
/*. trigueter, Conrad,

P (Vcrlumnia) avis, Hall,

P. (V. ) rcprolm, ai«,

P. (V. ) revcrsa. Hall,

l^TERINOI'KCTKN, Hall,

P.
P.
P.
P.
P.

I*.
P.
1-
P.
P
P.
P.
1'.
/'.
P.
P.
I'.
1'.
P.

conspectus, Hall, . KJ,

rrenicoslatiis. Hall, .

crenulatut, llall,

difcnatus. Hall,

dispandiis. Hull,

erectus. Hall. .

exToliatus, Hull,

ftlitcxtus, Hall,

Berines, Hall. 59, (i-2,

imbecilis. Hall,

insons, Hall,

intennedius, Hall,

invalidus, llall,

\ailua. Hall, .03

iautus, llall,

multiratliatus. Hall,

Ncptunus, Hall,

nodosus, Hall, .

rcflexus, Hall,

regidaris. Hall,

spoitdylus, Hall,

ttrictus, llall, .

suljorl)iculai*is. Hall,

terminnlti, llall,

unilosus, Hall,

Vorlunums, Hall,

(Avicu!oi>cc,ten ?) strictus, Hall,

xlll xvii,57,
U5, 06, r>8. Oil,
58, 78, 79,

3-2, 62, M, «5,
72, 76,

.i9, 60,
67,
03, 64, 66, 67,

Ptero.vitks, McCoy,

(Xlil) xvii

1". inoptalus. Hall,

P. Jarfa, (llall). S. A. Miller, .

/*, muricatus, llall, .

P, profundus, HttU,

I*. ro.stratus, H^dl,

/'. spinigerut, (Conrad) S. A. Miller

/'. aubdecussala, llall,

I'TYCIIODES.MA, Hull if' Whitfield.

1". Knappinnuni, Hall if Whitfield,

P.I minor, llall,

P. minor, Hull,

P. nanuni. Hall,
PTYCIIOPTEUIA, Hall,

P.

alata. Hall,

p.

Bceclicri, Hall,

p.

clonftaUi, Hall, .

i>.

Kucrate, HaU,

p.

Eudora, Hall, .

p.

expansa, Hall,

p.

I'alcata, HaU, .

p.

Galeae, Hall,

I>.

)rilil>osa, HaU, .

p.

lata, HaU, .

p.

loliala, HaU,

p.

purlaui, HaU,

p.

ProU), HaU,

p.

Salamanca, HaU,

p.

Sao, HaU,

p.

8inuosa, HaU,

133,

132, 134,

PAGE.

80

. 265

106

. 106

104

248

60,

.31,
65, 66, 67, 75,

74
81
78
67
77

77

61
70
69

76
61

68
67

107

69,

44, 58, 77, 78,

67

70

60

68

70

66

74

80

. 32

72

71,76,79, 106

74

161,208, OT, '239

230

. 1.58

108

239

238

177

110

3.52

8.54

363

363

353

•206

144

143

141, 143

, 137, 138, 142, 143

. 138

152

. ise

142
140, ISO

146, 147
. ISO

147, 148
120, l:iS
131, 134

135, 137, 145, 148, 323
1-29, 130

237,

xxix,

xxix, 362,

xli) xvii, 1-29,
130, 141,

INDEX.

561

rtychopteria spatalata, StUl, .

I'. Spio, Ball, .

P. Thalia, floK, .

P. Thetis, Ball,

P. trigonaliis, Ball,

P. Vanuxemi, Ball, .

Rhynchonella congi'o^tji.

Sanguinolaria, .

S. laniellofia, Oold/tut, .

PAGE.

. 144

137, ISS

. 148

136, ise

140, 144

ISl

■JSl, SIO

li

. 308

SANGIIISOI.ITKS, McCoy, XXX, xxxiii, xxxiv, I, 11, 175, 508

S. acutut. Hall a»

5. .£olut. Hall, 404

S. amygdaUnu>,\Vinc.he\], 291 , 4»5, 496, 497, 501

S. arca/ormia. Hall, .... xxxiii, 39.')

S. carinatus, (Conrad) Hall, . ,301

S. ChemungeiuU, Vanuxein, . . 303

S.I elavultu. Hall 401

S. euiuatut, (Conraill Hall, . . . :i!IU

S.I fiaviut. Hall 40:1

S. Olaucu; Hall *«

,sr. Bamiltonensis, Hall, . . -296

S. Ida, Hall, ...... 300

S perangulatut. Hall, ..... '293

S.I pondero$u$. Hall 271

S. rtgidtu, (White .<t W'liitliclill Hall, . 3U-.I, 400, 402

jr. rugotut, (Conraill Hall, .... 297

S. toleuoida. Hall, :t»8

S. ntbtortuoMtu, Hall, .... 397

.S (?) »ulitruni-atu8. Hall 508

S. tulcalus, MrCo.v, ..... li

S. tulc\ftrut. Winchcll 487

S. <run<»i<u«, (Conrail, 8p.l Hall, . . 394, 482

S. undaiui. Hall. ..... 481, AOK

S. (?) unc|ulatu:<, Ball. ..... SOS

S. ralvultu. Hall 4U3

S. rentriconu, (White A Whitllelil) Hall, 407, 408

S. e«n<r<c<Mtu, (White .t WhilMclillS. A Miller, . 408

»CHIZt>ui:n, King, ssxix. 1 ill, 44.5, 417, 451

8. a.-i|uali9. Ball 459

S. UMtrviMi^, {Conrad) Ball, xl. 448, 449, 4.'>0, 4.52, 4.54

.S. Cayuga, Hall ■ . 449

■S. Cheinungenni^, iConrad) Ball, . 453, 4.Vi

S. Chemungcn!«is, var. (|ua<lrangularis, 454, 4ft(>

8. contractus, Ball *51, 45U

8. cuneus. Ball. .... 4,51, 458

8. degener, B€ill, ...... 456

S. elhpticus. Ball 450

8. eminent. Ball, ...... 457

8? flMa, HaU *47

8. gregariuii. Ball 4S«

PAGE.

Schizodus oblatus. Ball,

. 455, 456

S.

patulus, BaU,

467

s.

quadiangularis, BaU, .

453, 454

s.

rhombous, BaU,

458

.s.

truncatus. King,

xxxix

■S.

tuniiilus. Hall,

. xl, 448, 449

■SOLEMVA, Lamarck, .

Xll, liv, 463

S.

Australis,

xli

s.

vutusta, .

. xli, 513

s.

(Jancia) vetusta. Meek,

463

SOI-EN

,L.,

. 241, 483

S.

(Palieosolen) siliqnoidea

BaU,

483

Si'ATHELLA, Ball,

xxxill, xxxiv, 407

S.

typica, BaU,

. xxxiii, xxxiv, 407

S.

ventricosa, Ball,

xxxiv, 408

Sphenomya,

xxxii

SfHENOTUS, Ball,

xxxiii, xxxiv, 394, 406

8.

.aiolus. Ball,

404

:^.

arcajlormis.

xxxiii, 394, 396, 396

S.(?)

arcuatus, BaU,

400

S.

arcuatus.

. 402

S.

clavulus. Ball,

401

s.

contractus, Hall,

xxxiii, 399, 402

8.

cuneatus, Hall,

396, 396, 400, 406

s.

flavins. Ball, .

. 403

8.

rigidus, BaU,

403, 405

s.

signalus. Bail, .

. 405

S.

solenuides, .

xxxiii, 277, 398

s.

suliFortuosus, BaU,

397, 401, 406

.s.

Tclainon, BaU,

406

8.

truncatus, Ball,

. 394

S.(?)

nudalns. Ball,

606

.^_

valvuluj-. Ball, .

. 403

Spiri/era disjuncta, .

xix

.-•.

mucronata,

. 281, 302

8.

Vei-neniH, Murchison,

. xix

131, 189, 224, 2:18, 323

Streiiloiteria,

Ix, I.xi

TeUina ovata, IIM,

335

Tei.lino.mva,

xxviii, 324

T.

{.Dyitactella) subnamta,

Hall A Whitlleld, . 512

Tellinopsis, J7aU,

. xll, 464

T.

subemarginata, {Conrad) Ball,

xlii, 464

Ungulina suborbiculaiii^, BaU,

. 393

l^nio.

XXX

Venericardium retro.striatun), v

Buck,

XXXV, 426

Vertiimnia, BaU,

. (Xil) 104

-\ylop

laga, .

xl

Yoldia

, . .

xxviii

T.I

valvultu. Hall & Whittle

Id,

463

Klymklla lkvata. a .xiieciineii i-etaiiiing- lioth valves in conjunc-
tion. SvK pa^ 504. Hamilton Gi-ouj). Schoharie County, N. Y.

Pahbrka altkbnata. View of a large right valve showing the form of the shell and the general charac-
ter of the 8Ui-face ornamentation. The central portion of the valve has l)een broken away, and the ra<lii are
obscure on the marginal jxirtions. 'I'he specimen is pi-esci-ved in the rtolomitic limestone of the Upper
Uelderberg group, from near Columbus, Ohio. See pag'e 416.

PLATES AND EXPLANATIONS.

PLATE XXXIV.

GoNIOPHOItA PEKANGULATA.

Pnge ■i»3.
See Plata 42.
Fiffs. 1, 2. Two It'ft valves, showing the general clmracloi-s of the species.
Fi^. 3. A .small right valve.

Figw. 4-6. Right, aiit<>rior ami cardinal views of a .«ipe<uinen preserving both valves.
S<'hoharie grit. Schoharie, N. Y.

GONIOPIIORA ? ALATA.

Page iiH.
See Plate 42.
Fig. 7. An imi>erfect right valve.

Schoharie grit. Sc?ivharie, N. Y.

NyASSA ELLIPTICA.
Pnge 387.
Fig. 8. A right valve with the shell almost entirely i-emoved, showing the muscular scars an(i hinge-line
as pi-eserved on the cast of the interioi-.

Comiferous limestone. StMff"rd, N. Y.

MODIOMORPHA CONCENTRICA.

Page 275.
See Plates 35, 36.
Fig. 9. The right side of a small .specimen.
Fyf..,^lQ. A. l^Ege ^pecijiien shiiwing the anterioi' mugculfli- scar ar^d pallial line. , ^

MoDIOiMORPHA ? PONDEROSA.

Page 271.
See Plate 3.5.

Fig. II. A cardinal view of the specimen, with the right valve partially worn away.
Fig. 12. The left side of the same specimen. See plate 35, tig. 8, for another figure of the same.
Corniferous limestone. Clareiu-e Hollow, N. Y.

MouiOMORPHA Schoharie.

Pajcc 269.
See Plate 35.

Fig 13. The right side of a cast showing muscular scars and pallia! line.
Schoharie grit. iSrhoharie, N. Y.

MODIOMORPHA COMPLANATA.

Pago 272.
See Plate 41.

Fig. 14. A i;ast of a left valve showing muscular impressions and pallial line.
Comiferous limestone. Near Delaware, Ohio.

MODIOMORPHA LINGUIFORMI8.

Pnge 271.

Fig. 15. The right side of the cast preserving a portion of the thickened shell, referred with some doubt to

this species.
Fig. 16. A cardinal view of a cast of the interior of another spc(-imen.
Fig. 17. The right side of the preceding.

Comiferous limestone. Columhwi, 0.

IfflFIPlilE III2iaiE)IlIldIBIS2id(B ©miffiWlP.

Palaeontology NYVol V

( IIODIOMOIIPHIIJ^K . )

Plate

-G.B.Simpaci- del

avriiLtoii, Utb. .

PLATE XXXV.

MODIOMOKPHA COXCENTKICA.

Page 275.
:. '."-'^^'^kt-^' ^•'^ Plates 34, 36.

Fig. 1. A right valve of a young individual showing a strongly lingular umboiial I'idge, a furrow along
the middle of the cardinal slope, and the antei'ior muscular impression.
Hamilton gi-oup. Delphi, N. ¥.
Fig. 2. A somewhat larger left valve of an individual presenting' characters similar to tlie pi-ecoding.

Hamilton gi-ouji. filiore of Caijuya laki-, N. Y.
Fig. 3. Thi! right side of a large individual showing the arcuate forai characteristic of old individuals.

Hamilton group. Schoharie Co., N. Y.
Fig. 4. A left valve of medium size of very short and broa<l fonn.
Hamilton group. Shore of Cayuga lake, N. Y.
Fig. 5. The interior of a left valve of a short and broad form, showing a strong tooth inider the beak, with
the anterior and posterior muscular scars and ci>nni'cting pallial line,
.m ^ Hanjilton group. Delphi, N. Y.

MODIOMORPHA SDBALATA.
, , , Page 283.

See Plate 39.
Fig. 6. A right valve of an unusually short and broad specimen.

Hamilton group. Delphi, N. T.
Fig. 7. A right valve of unusually elongate form.

Hamilton group. Delphi, N. Y.

MomOMORPIIA PONDEROSA.
Page 271.
Sec Plate 34.
Fig. 8. The left side of a cast showing the form an<l muscular scars.
Coniiferous limestone. Clarence Hollow, N. Y.

MODIOMOKPHA RECTA.

I'liffe aSG.
Fig. 0. The nght side of a cast showing the muscular seal's and pallial line.
Hamilton group. Clarke Co., Ind.

MODIOMORPHA SUHAN(iUL.\TA.

Page 2S7.
Fig. 10. A Hght valve showing the anterior muscular scai'.

Chemung group. Ma7i,<sfiel(l, Pa.
Fig. 11. A smaller i-ight valve showing the muscular scare.

Chemung grcuip. Mansfield, Pa.

I'LATK XXXV— CoiiUiiuuil.

MODIOMORPHA REOULAUIS.
Pafto J70.
Vig. 12. A partial cast of a right valve pi*eserving the siii-face markings.

Schoharie grit. Scholiarle, N. Y.

.1.

MODIOIIOKPHA AFFINIS.

Page 281.
See Plate 37.
Fig. 13. The right kUh of the'specimen described.

Hamilton group. Onondaga Co., N. Y.

MoDioMOEPHA Schoharie.

Pago 369.
See Plate 34.
Fig. 14. The right side of a specimen imperfectly preserving the surface markings.
Schoharie grit. Sc/wliarie, N. Y.

ir!P3^Eii 2EEi.i]23n3sii(&:rD :s'M^msmm ®m^ms>.

Palaeontoloiy of N.T,Tol.YR.I,

PlateXXXV.

x'L.AiJT htii.

PLATE XXXVI.

MODIOMOKPHA CONCENTUICA.
Page -27').
See Plates 34, 35.
Figs. 1-12. Showiiij!' the variety of fonn, ni/.e ami surface marking's cliaractei-i.stic of the species.

Hamilton {fi-oup. Shores of Cayuga, iSeiieca, CaiMiuiaigtm lakes and Pralt's falls, N. Y.
Fig. 13. A cai-ilinal view showing' the ligamental ai-ea and ligament.
V'lg. 14. A i>ai-tial ca.st of the intei-ior showing the anterior muscular scar and pallial line.

Hamilton group. Cximbtrland, Md.
Fig. 15. The cast of the interior of a left valve showing muscular scars, pallial line, and the striated hinge ^

area of the opposite valve. ■■

Fig. 16. The interior of the left valve, partially obtained by a gutta-percha impression, showing the strong
UK>th and the callosity below, with musculai' scar and pallial line.
Hamilton gn)up. Cumberland, Md.
Fig'. 17. A cast of the left valve showing the anterior muscular scar, the cavity of the tootli and the impnw-

sion of the striated ligamental aiva. '

Fig. 18. A gutta-]iei-<;ha impi-e.ssion from the i)rece<ling, showing moit; clearly the charactei-s of the interim'.
Hamilton grwup. Schoharie Co., N. Y.

MODIOMOKPHA CYMBULA.

Page 282.
Fig. lit. A cast of the interior of a left valve showing the mu.scular .scars and pallial line.
Fig. 20. A gutta-pei-cha impression from the pi-cceding.

Hamilton gi-oup. East Worcester, N. Y.

MODIOMORPHA AKCUATA. i

!
Page 281.

Pi(f. 21. A partial ca»t of the interior, preserving' some of the surface markings and showing the anterior
muHcular scar.

Hamilton gi-oup. Schoharie Co., N. Y.

Palaeontology NYVolV

( .M o u 1 G M ini )' 1 1 i ^)A■: . )

Plate XXXVI.

O.B.&ilCL;:^;..

Riemanivhth

■ J ry.njio/.ir j-.u'iuc,.

PLATE XXXVII.

MODIOMORrHA ALTA.
Page 278.
See Plate 80.
F\g». 1, 2, 7-12, 15, 16. These fig-ures represent characteristic specimens of this species in its various
phases of growth. Fig. 15 is the type specimen descnbed by Mr. Conrad.
Hamilton group, ^hore of Seneca lake, N. Y.
Figs. 4-6 are doubtfully referred to this species, approaching H. mytiloideg in form.

MODIOMORPHA .MVTILOIUES.

Page 277.

See Plate 38.
Fig. 3. A small left valve of this species.

Hamilton group. Pratt's falls, N. Y.

MODIOMORPHA AFF1NI8.
Page 284.
See Plate 35.
Figs. 13, 14. Right and cardinal views of the specimen described.
Hamilton group. Onondaga Co., N. Y.

MOWOMOKPHA JIACILENTA.

Page 280.

See Plate 39.

Fig. 17. The right side of a crushed 8i)ecimen.

Hamilton group. From a boulder of shaU in Catherine township, Schuyler Co., N. Y.

.?fl4\MiniLlE'(BBg ©mmTDTIP.

Palaeontology NY.VolV.

f MOUIO.MOIU'IIII)^', . I

Plate XXXVE.

O.S.rixii^^iiGK). del .

PLATE XXXVIII.

MODIOMORPHA MYTILOIDKS.

Pafce i77.
Sc^ Plati' 37.
Figs. I-IH. A sfM'ies of speeiineiis illustrating' the principal varieties of form iiiiil sin-face characteiti of this
sjiecieH. In tig. 13 the valves ai-e still connected by the lig-ament.
Hamilton group. Eastern ami central Nno York.

m^AMniLirmsg ©mmwiF^

Palaeontology NYVolV

( MODIOMOHPIIID.*:

O.6. ^mpscox del

Wiemaiuvlish

r »Jw>iir|f.V

PI.ATE XXXIX.

MODIOMORPHA 8UBALATA.

Vage 283.
See Plate 3a.
Fif.'s. 1-14, 16. Illustrations showing: the pliiises of this species from the smaller' individuals to the larger
anil full-grown forms.

Hamilton group.

MODIOMOKPHA SUBALATA, V:ir. ChEMUNGENSIS.
Page 284.
See Plat* 41.
Fig. l."). A cardinal \new of a crushed specimen.

Chemung group. Ithaca, N. Y.

MODIOMORl'HA MACILENIA.

Page' 280.
See Plate 37.
Fig»<. 17-20. Two small left and two large right valves, fig. 20 i-epresenting a specimen of unusual size.

Hamilton group.
Fig. 21. A cardinal view of a crushed specimen showing the ligamental area with the ligament partially
presers-ed.

Hamilton group. Pnm a boulder of shale in Catherine township, Schuyler Co., N. Y.

lEL^saniLTFms'r ©mmwip.

Palaeontology NY.Vol V

( MonioMonpHiD^ . )

Plate XXXIX.

O.B. SimpaoKL del

Ri8mann,li:ii.

PLATE XL.

AUNIQENIA CaTSKILLENSIS.

Pajtc 516.
Sec Plate SO.
Vig. 1. A vertically compressed specimen, giviiifr ii imritiw a,spect. to the valve.

Tliis is the form orig-iimlly (lesci-ibcl by Va.vi'XBM as Cypricarditex aitgustata.
Kijfs. 2-4. The oiilinary forms of this species.

Oneonta sandstone. Near lit. UpUm, A'. 1'.

Elymklla fabalis.

Fig'-'. 5, Jt. Two sj)ecimens of onlinary si/,(', retaining: both valves.
Hamilton group. Slurre of Crtxtkcd hike, N. Y.

ElYMKLLA MUCliLOIDES.
Page 503.
Figs. 6-8 (10 ?). Individuals showing the jjhases of the species as observed in the Hamilton groii)i

ElYMELLA 1'ATUT,A.
Page 505.
Fig. 11. A specimen preserviiifr the two vahes in conjunction.
Waverly group. Mtd'ma, 0.

Glossites subtenuis.

Page 495.
Figs. 12, 20. Two right valves.

Hamilton group. Near Oeneva, N. T.

Glossites amygdalinus.

Page 501.
Figs. 13, 14. A right valve, and a specimen presei-ving the two valves in coiijiinctioii.
Yellow sandstone. BririingUm, Iowa.

Glossites depkessus.

i'ag« 496.
See Plate <»6.
Figs. 15, l7. Two left val\es of this si)ecios.

Chennnig group. Ithaca and Elmira. N. Y.

Glossites lingualis.

Page 497.
See Plate 96.
Figs. 16, 19. A left and light valve as pi-esei-ved in soft shales.
Chemung gi-oup. liehiitml, N. Y.

MoDiOMOKPHA Tioga.

Page 291.
Fig. 18. A left valve.

Chemung g^roup. Manxfield, Pa.

Palaeontology NY.Vol V

( ^to^IOMOHPl^^3vl•■. . I

PlatelL.

i^icTiai-aUi;

PLATE XLI.

MODIOMORPHA rUTILLUS.

J 'age 271.
Figa. 1, 2. Left and cardinal views of a cast.

Schoharie grit. Sc/wharie, iV. Y.

MODIOMOKPHA COMPLANATA.

Page 27-2.
See Plate 34.
Fig. 3. The left side of a siieciraen pai'tially preserving' the surface markings.
Coniiferous limestone. Bal>cock\s hill, N. Y.

MODIOMOKPUA Cl-AUENS.

Page -273.
Fig. 4. A light valve.

Corniferous limestone. Clare/ice Hullirw, N. Y.

MODIOMORPHA 8UBALATA, Viir. ChEMUNOENSIS.

Page 284.

See Plate 39.
Figs. .5, 6. Ijcft and i ight valves.

Lower Chemung group. Itliaca, iV. Y.
Pig. 7. A broa»ler foi-m with a convex ba.sal margin, doubtfully referred to this species.

Lower Chemung gi-oup. Ithaca, N. Y.
Figs. 8, 9. Two specimens ii;taining both valves.

Lower Chemung group. Ithaca, N. Y.
Fig. 10. A left valve.

Lower Chemung group. Ithaca, iV. Y.
Fig. 11. A right valve, more elongate than the usual fonn.

Lower Chemung group. Cortland Co., N. Y.

Leptodesma complanatum.

Page 227.
See Plate 22.
Fig. 12. A left valve an-anged on thi.-* plate by mistake. The position of the figure is obliciue, and the
decurving of the 8tri» along the hinge is not shown.
Chemung group. Steuben Co., N. Y.

MODIOMORPHA NEGLECTA.

Page 290.
Fig. 13. A right valve.

Chemung group. Near Elmira, N. Y.

PLATE XLI— Continued.
MOUIOMORPHA KIGIDA.

1-iigc -JST.
Figs. H-IO. Left vulves in their natural form and jii-oportions.

Chemung gi-ou|). Alhff/iany C'u., JV. Y.
Fig. 17. A specimen vertically compressed ; referi-etl with doubt to this species.

Chemung g-roup. Belintmt, N. T.

MoorOMORPHA QUADRULA.
Page -JsS.
Figs. 18-26. Figures presenting the prevailing varieties of fonn in this species.

Chemung group. AUeyhany and Vnttaravyiis couvtus, N. Y.

Ptychodesma minor.

Page *)3.
Fig. 27. A light valve of this species.

Chennuig group. Near Elmira, N. Y.

MODIOMORPIIA HVALEA.
Page 292.
Figs. 28-30. Three i-ight valves. In fig. 30 the radii are too strongly i-epreseuted.
Waverly sandstone. Chranmlle, 0.

Palaeontology NY.VolV

( MODIOMORPiriD^f. . )

Plate. ILL

I

O.B.oiityp»ou did.

PLATE XLII.

GONIOPIIORA PERANGULATA.
Page 293.
See Plate 34.
Fig. 1 . The right side of a small specimen preserving the test and surface markings.
Fig. 2. A cardinal view of a left valve showing the posterior muscular scar, the furrows left by its reces-
sion from the beak, and the convexity of the valve.
Schoharie giit. Schoharie, N. Y.

GONIOPHORA ? ALATA.

Page 294.

See Plate 34.

Fig. 3. A large right valve, somewhat crushed along the umbonal I'idge and preserving some of the

stronger concentric striae.

Schoharie grit. Schoharie, N. Y.

GONIOPHORA MINOR.

Page 305.
Fig. 4. A right valve. _

Figs. 5, 6. Left valves showing some variation in form.

Chemung group. Ithaca, N. Y. ■>

GONIOPHORA RUQOSA.

Page 297.
See Plate 43.
Fig. 7. A short, broad right valve of this species.

Hamilton group. Shore of Cayuga lake, below Ithaca, N. Y.
Fig. 8a. A short form with a strongly angular and curving umbonal ridge. A right valve of Mierodmi
(Cypricardella) hellistriata is on the same block of stone.
Hamilton group. lAuUowville, N. Y.

GONIOPHORA TRUNCATA.
Page 298.
See Plate 44.
Fig. 9. A cardinal view of a right valve.
Fig. 10. A left valve showing muscular scars and pallial line.
Hamilton group. Pratt's falls, N. Y.

GONIOPHORA CARINATA.

Page 301.
See Plate 44.
Fig. 11. A right valve showing the principal characters of the species in a very satisfactory manner.
Hamilton group. Mt. Upton, N. Y.

GONIOPHORA TRIGONA.

Page 302.

See Plate 44.

Fig. 12. A left valve, redrawn to show more clearly the specific characters than are represented in fig. 9 of

plate 44.

Chemung group. Franklin, Delaware Co., N. Y.

.IIJZ MTAjq

PLATE XI<n— ContInne<i:

Gojsioi'HOKA Ida.
18 1<>»1 siira«e aoo. I nemboqs lUnm «lo sbbi idiJrt sifT .1 .-jiH
• 8ee Platfi 65. ' ~ yi"^

Kig. 13. A si>ecimen retaining both valves connected by the hinge ligament.

Hamilton group. Belhna, N. F. ''■ •'i''^"''"'"'^ ■*"•» «"-i"«l3«

GONIOPHORA 8UBRECTA.
Page SW.

See Plate 44.
Fig8. 14, 15. Two left valves. :jlri li.r I jiH

Chemung group. CharlotteTiiUe and Jefferson, ScbdiarieOo.t.N. y

i ./. .:«iv>kV>i\ iV' 'iix srxurforfofl
MiCRODON (CyPRICARDELLa) TENUI8TRIATU8.
Page 310. ' ' ' '

See Plates 73. 74. ...vf-^ ,rf^h /

Pig. 16. A cardinal \'iew of a sjiecimen i"etaining both valves. .^;,I

Hamilton group. Ciiinherland, Md.

MiCRODON (CvPBICARDELLa) BELLI8TRIATU8.
Page 308.
See Plates 73, 74.
Fig. 86. A short and broad right valve, showing the hinge and the cardinal teeth. ''^ ■♦!"«* /

Hamilton group. LudloxBville, N. Y.
Fig. 17. A cardinal view of a small specimen preserving both valves. -■

Hamilton grouj). Cnmherland, Md. >>Hq)fJ)

Fig. 18. A specimen showing the valves opened and attached along the 'hinge-line.

Hamilton gi-oup. BdUma, N. Y.
Pig. 19. An unusually short and bi-oad form. ; , : '

Hamilton group. Shore of Cayuga lake, N. Y.
Fig. 20. An enlargement of the hinge of a right valve.

Hamilton group. Shore of Seneca lake, N. Y. . ^. .

'1 1)1111 i^-iii'w ■uUi! '1«7 rtal A .01 .-gVi

MiCRODON (CVPKICAftDliJt-LX') MAJOK.
Piiiie 307.
Pig. 21. A right valve showing the form of the shell and the Surface markings.
ComifeTOUs limestone. Delaware, Ohio.

MiCRODON (CyPRICARDELLA) COMPLANATUS. '!' J*!^" '

Page 311.

See Plate 74.

Fig. 22. The left side of a specimen which is a partial cast or the interior, showing the muscular si^ra and

pallial line.

Hamilton group. NorvAeh, N. Y.

•no'n 7roff^ oJ nwjnbai ^vUv ftoJ A .CI .1|1M

• iiifiinAffTk

im?ipi£ii :£!32LaD:EJ03Eii:B'3'D '^"jEEsoEr© ©m©TiJiP=

palaeontology of NY.Vol.yR.r.

PlateXLH.

■t..r,::iiii'.r.E iei.

Ph.AsT litii.

^p^

PLATE XLIII.

f

GONIOPHORA ACUTA.
FHge'295.
Figs. 1, 2. Left valve au<i cardinal view.

Fig. 3. A cardinal view of two valves in conjunction, somewhat compressed.
Hamilton group. Shore of Canandaiffua lake, N. T.

GoNIOl'HOItA RUGOSA.
Page 287.
See Plate 42.
Fig. 4. The left valve of a small indi\-idual.

Hamilton gixnip. /Shore of Catmndaigua lake, N. Y.
Fig. 5. A larg^ left valve in its natural form and proportions.

Hamilton group. Shore of Cayuga lake, N. Y.
Fig. 6. A left valve more produced anteriorly than the preceding.

Hamilton gi-oup. Stiore of Catmndaigua lake, N. Y.
Fig. 7. A specimen pi-eserving the two valves in conjunction.
Hamilton group. Schoharie Co., N. Y.

GONIOPHORA HaMILTONENSIS.

Page 296.
Fig. 8. A right valve below the medium size.

Hamilton gT-oup. FiiUonham, Schoharie Co., N. Y.
Figs. 9-12. A series of young individuals.

Fig. 13. An imj>erfect right valve preserving a portion of the test and showing the anterior muscular im-
pression.

Hamilton group. Faltonham, Schoharie Co., N. Y.
Fig. 14. A right valve in its natural proportions.

Hamilton group. Bear's &ulf, Schoharie Co., N. Y.
Fig. 15. The two valves in conjunction, the right valve pi-eserving its natural foi-m and proportions.

Hamilton group. Scholiarie Co., N. Y.
Fig. 17. A cardinal view of a specimen preserving both valves.

Hamilton group. Schoharie Co., N. Y.
Fig. 18. A partial cast of a large right valve, showing the imprint of the hinge area.

Hamilton group. Scholiarie Co., N. Y.
Fig. 19. A gfutta-percha impression fi-om the preceding.

Fig. 20. A cardinal view of two valves in conjiniction, which are somewhat narrowed by compression.
Fig. 21. A cardinal view of two valves conjoined by the ligament. The specimen is vertically compressed
and the cardinal slope flattened.

GONIOPHORA GlAUOUS.

Page 299.

See Plate 44.

Fig. 16. The left side of the specimen partially preserving the shell and showing the anterior muscular

impression.

Hamilton group. Shore of Cayuga lake, N. Y.

lEUV-MHaTTSSf ©Iii©W2i> =

Paleeontology NYVol V

( M 01)10.\U>l!riIII>,K

Plate XLUI

C-.B.rTUE4t»0L d«l

.PhiV^aiJiih.

PLATE XLIV.

GONIOPHORA TRUNCATA.

Page 298.
See Plate 42.
Fig-. 1. The right side of a crushed specimen showing the surface markings.

Hamilton group. Shore of Cayuga lake, N. T.
Fig. 2. The cardinal view of the preceding.
Fig. 3. The right valve of a large individual pi-eserving the surface markings, and showing the

form of the shell.
Fig. 4. A fragment of a right valve showing the surface markings.

Hamilton group. Delphi, N. Y.
Fig. 5. A portion of a right valve from a gutta-percha impression of the natural mould.

natural

Figs.

GONIOPHORA CARINATA.

I'agc 301.
See Plate 42.
6-8. A series of Bjjecimens showing the graxlation of form and size.
Hamilton group. Schoharie arid Otsego Co's, N. Y.

Fig. 9. The left valve described.

Chemung group.

GONIOPHORA TRIGONA.

Page SO-i.

See Plate 42.

Franklin, Delaware Co., N. Y.

GONIOPHORA GlAUCUS.
Page 299.
See Plate 43.
Fig. 10. A large right valve in which the cardinal slope is narrowed from compression.
Fig. 11. A right valve.

Hamilton group. Madison Co., N. Y.
Fig. 12. A partial cast of a right valve of short form, showing the anterior muscular impression and pallial

line. Hamilton group. Near Apiclia, Onondaga Co., N. Y.
Fig. 13. A cast of the interior of a left valve showing the hinge area, the anterior muscular impression and
pallial line.

Hamilton group. Bear's Qulf, Schoharie Co., N. Y.
Fig. 14. A gutta-jiercha iinpres.sion fi-om the preceding specimen.
Fig. 15. An unusually elongate left valve of this species.

Hamilton gi-oup. Kellogsville, Cayuga Co., N. Y.
Fig. 16. A cast of a right valve preserving some remains of the shell, and showing the anterior muscular
impression and pallial line.

Hamilton group. Schoharie Co., N. Y.
Fig. 17. A right valve of a specimen of medium size.

Hamilton g^roup. Madison Co., N. Y.

.Al'AWiaAD

PLATE XUV— Uonlinacd.

GONIOPHORA ClIEMUXGENSIS.

'■'i-'- '"■'= '■"■ Page SOS.
Fig. 18. A. right valve.

Chemung group. Owego, N. T.
Fig. 20. A left valve of this species.

Chemung group. Binghamlon, N. T.
Fig. 22. A right valve of a large individual.

GONIOPHORA SUBRECTA.

rage 304.
See Plate 42.

Pig. 19. A left valve preserving the usual form.

Chemung group. Franklin, Delaware Co., N. T.
Fig. 21. A left valve of a large individual.

taiH«q /.

-uii

iiL4\5MiLir®jtr ;i^ sisies^iims"© ©iii®T3i?s ,

Palaeontology NYVol V

( sionioMOHi'Hiu^: . )

Plate XLIV.

.O.3.lsitov»0n. d«.

PLATE XLV.

NOCULA NIOTIOA.
Page 313.
Fig. 1. A cast of a right valve showing- the muscular scars and umbonal pits.
Fig. 2. A right valve preserving the surface markings.
Hamilton group. Louisville, Ky.

NdCULA NeDA. ;iimb-ui3

PftSre 3U. '

Fig. 3. A cast of the left valve showing muscular scai-a and hinge crenulations.
Fig. 4. A cast of a right valve showing muscular scars.
Hamilton group. Louisville, Ky.

NUCULA LIRATA.
Pafte 316.
See Plate 93.
Fig. 5. A right valve showing anterior muscular scars.

Hamilton group, ffamilton, Madiscm Co., N. Y.
Fig. 11. A large right valve.

Hamilton group. Shore of Seneca lake, N. Y.
Fig. 15. The left side of a cast showing the muscular scars and hinge ci-enulation.s. The on-nnlatioiis in

the figrnre are continued too far towaiils the posterior end.
Pig. 17. A right valve more strongly marked than the preceding.

Hamilton group. Shore of Seneca lake, N. T.
Fig. 18. A left valve.

Hamilton group. Shore of Seneca lake, N. T.
Pig. 19. A right valve of gibbous foi-m.

Hamilton group. Sliore of Skaneateles lake, N. Y.
Pig. 20. A left valve.

Hamilton gi-oup. Shore of Skatieatelcs lake, iV. Y.
Fig. 21. A left valve enlarged, showing some of the crenulations of the hinge-liue.

Hamilton group. Shore of Ovoasco lake, N. Y.
Fig. 22. The surface of the preceding specimen enlarged.
Fig. 24. A cast of a left valve enlarged, showing muscular scars.
Fig. 25. The cai-dinal view of the preceding, showing muscular scai-s and hinge crenulations.

PLATE XLV— ConUnued.

NucuLA Randalli.

I'aRO 315.
See Plate 98l'l
Pigs. 6, 9. Right and cardinal views of a specimen.
Fig. 10. An enlargement of the left side of the preceding.
Figs. 7, 8. Right and left -vnews of another specimen.
Fig. 16. An enlargement from the preceding.
Fig. 23. A cardinal view of a specimen enlarged.

Hamilton group. Sliore of Seneea lake, N. Y.
Fig. 26. The left side of a cast showing muscular scai-s and pallial line.
Fig. 27. The cardinal view of the same showing muscular soirs and hinge crenulatious.

Hamilton g^-oup. Ovmberland, Md.

NuCULA DIFFIDEN.S.

P8ge82,!. ^ tiojlliilj'.ll

Fig. 12. A cast of a left valve showing muscular scat's and surface striae.

Lower Chemung gi-oup. Ithaca, N. T.
Fig. 14. A left valve, imperfectly preserved, showing surftice strise and posterior muscular scar.

Lower Chemung group. Ithaca, N. Y.

NnOUIiA tAMEt-TiATA.

Page 3-20.
See Plates 51, 93.
Fig. 13. An enlai-gement of a left valve of this species, imperfectly repi-esented.
Lower Chemung group. Itltaca, N. Y.

NucuLA Houghton I.

I'lige 3>3.
Fig. 29. A partial cast of a right valve showing the exterior markings.

Fig. 30. A giitta-pei-cha imjiression fi-om a cast of a left valve, showing hinge crenulations, musculai- scars
and pallial line.

Waverly group. Newark, Ohio.
Fig. 31. The cast of the interior of a left valve enlai-ged, showing muscular scai-s, pallial line, hinge ci-enu-
lations and cartilage pit.

Waverly group. Neumrk, Ohio.

„i,A SUBELLIPTIOA.

.•Mniil«Iiin*i!i fty^ntii Imji frm-xi tp.ii) i-. .-jaiii'

Pajfe 317.

Fig. 28. A cast of a right value, natural size, showing muscular scars.

Hamilton group. Cutnberland, Md.

Palaeontology NYYolV

Upper Heldorberg & V/averly Groups

PlateXLV:

7

13

17

18

^ ^

^jjJj^y^VllljaiW***'^

,^M^^'

2h-

25

'^W. -.i^^

28

O.B , IVinxps on di

fivirnjifM

PLATE XLVI.

NUCULA BELLISTBIATA.

Page 318. ,( Si ,M .; .: i

Fig. 1. A right valve, natural size. <» nA «f - i'l

Hamilton group. Delphi, N. Y.
Fig. 2. A right valve enlarged to two diametere, showing the surface markings and anterior musculai"

scar. Hamilton group. Northtnlle, Cayuga Co., iV. T^ .
Fig. 3 A right valve of broader form than usual, enlarged. ■

Figs. 4, 5. Two left valves enlarged, showing the foi-m and surface charactera.
Fig. 6. A large left valve, natural size.

Hamilton group. Shore of Skaneateles lake, N. Y.
Fig. 7. A specimen preserving both valves, enlarged.

Hamilton g:-oup. Tinker's falls, Onondaga Co., ^. T.
Fig. 8. An enlargement of the surface, from fig. 1 .
Fig. 9. A cardinal view of a cast, enlarged.

Hamilton groiip. Shore of Canandaigua lake, JV. Y.

NCCULA CORBULIFORMIS ?

Page 319.
Figs. 10, 11. Left and cardinal views of a cast of the interior, showing the muscular scars and hinge
crenulations.

Hamilton group. Shore of CaTiandaigua lake, N. Y.
Figs. 35, 36. Left and cardinal views of a compressed specimen, showing characters similar to the pi-eeed-

ing, enlarged to two diameters.
Fig. 37. A partial cast of a right valve of obscure character, enlarged.
Lower Chemung group. Ithaca, N. Y.

i:'/snq 9ril (iJldJ

PLATE XLVI— Contlnaed.

NUCULA VAKICOSA.

Page SI9.

See Plate 93.

Fig. ' 12. A left v&Ive, natural size.

Hamilton group. Shore of Cayuga lake, N. T.
Fig. 13. An enlaixement from the precedingBpepiniftf.-ji / mi
Fig. 14. A rijflit valve, natural size, witii more prominent umbo and beak than the preceding.

Hamilton gi-oup. Shore of Cayuga lake, N. Y.
Fig. 15. An enlargement from fig. 14. '"'■'''''■' '' ' ' ' ' l '^
Pigs. 16,17. Enlargements of left valves. .fij: •.-,

Fig. 18. An eularg<>ment of a left valve with an unusual gibbosity of flilf!*wSlBtf.*"' •

Hamilton group. Shore of Cayuga lake, N. Y. ■^l^^■>■<•'A >i<>JlinmH
Fig. I'i X len valve, ifftusually elongate fi-om tlie beak to the post-batol eifi^eittfty'.'etilarged.
Fig. 20. A right valve of the usual foi-m of the specie-s enlarged. • ; ; . ^

Fig. 21. An enlargement fi-om a specimen of unusual length fi-om the beak to the poRt-inferyoreJtti-enHtjf.
Fig. 22. An enlargement of the cardinal ai-ea showing the tine crenulations of the hinge. ' ' ' ■' ■'^' '

Hamilton group. Shore of Canaudaigua lake, N. Y. "' ''^■"'' ^ •* ■«'''

Fig. 23. An enlargement from the surface of the specimen, tig. 1?).

Hamilton ^-ou^i. Shore of Cayuga lake, N. Y. 'intasq. A .V .•giH

NdCULA CORBULIFORMI8.' "1" ^','

• iVi)\ o«y»ijIfftge 319. .qutrr^ ni>}IimaH

Fig. 24. An individual, natural size.

Hamilton gi-ouj). -Shore elf OvDOatolake, \N. YJ.
Fig. 25. A left valve of a larger individual.

liii \m\k-~\i.,^ uii, HaniiltiMi group. Bellona, Yates Co., ^. Y.

26. A right valve, with the umbo more elevated than usual, partly from compressiOD.

Hamilton gi-«)up^ Belioiia, JS- Y. ,,^ ,, ,, ..,;,, m

Fig, , 27^; AnenlBr^isenl.,fi:Qni tig. 34, showiqg more distiijctly th^ s^ju^ cjij^i^ters.^^ j^^j j^ ^ ^
Fig. 28. A left valve, enlarged.

Hamilton gi-oup. , Shore pfSkaneaieles Iqke, N. Y. ^ .„

Fig. 2i*. An enlargement of a left valve. .. „. ..™»j.i_ i

Hamilton gi-oup. Shore of Cayuga lake, N. i.
Fig. 30. An enlargement from fig. 25.
Fig. 31. A right valve, enlarged.

Hamilton group. Bellona, Yates Co., N. Y.
Fig. 32. A right valve, enlarged to two diameters.

Hamilton group. Ludlovmlle, N. Y.
Pig. 33. An enlargement of a left valve, which is more equilateral than the prevailing forms.

Hamilton group. Near Tully, N. Y.
Fig. 34. An enlargement from fig. 26, showing a few crenulations on the posterior part of the hinge.

Pig

m^ssaniLTrcDSjr ©m©TcriF.

Palaeontology NYVcl V

( nunjLiD.c . )

PlateXLVl.

O.B .Siiut>3c?u d*L .

■ Riemanrvlitl-i

PLATE XL VII. i

NUCUUTES OBLONGATUS.
Page 824.
Fig. 1. The cast of the interior of a left valve, partially preserving the surface strise.

Hamilton group. Sltore of Otisco lake, N. Y.
Fig. 2. A cast of the interior of a specimen preserving the two valves in conjunction, and showing the
crenulated hinge.

Hamilton group. Schoharie Co., N. Y.
Pig. 3. A cast of the intei-ior similar to the preceding.

Hamilton grouj) Bear's gulf, Schoharie Co., N. Y.
Fig. 4. A cast of the interior of a right valve, showing the charactei-s of the hinge.

Hamilton grouj). Shore of Skaiieateles lake, JV. Y.
Fig. 5. A large specimen similar to the preceding, showing more distinctly the muscular scars and pallial
line.

Hamilton group. Bear's giilf, Schoharie Co., iV. Y.
Fig. 6. The interior of a right valve as obtained from a gutta-percha impression.

Fig. 7. The interior of a large left valve as obtained from a gutta-percha impression from the natural
mould, tig. 9.

Hamilton group. Near Cumberland, Md.
Pig. 8. An enlargement from the preceding.

Fig. 9. A cast of a left valve preserving the muscular scai-s, pallial line and crenulations of the hinge, oi !
Fig. 10. A right valve of short form, preserving the surface stria?.
Hamilton group. Shore of Cayuga lake, N. Y.
Figs. 11, 12. Right and cardinal views of a cast of the interior, showing muscular scare and hinge
ci-enulations.

Hamilton group. Near Ciivibeiland, Md.

A'UCULITES CUNEIFORMIS.
tune 325.
Pig. 13. A cast of a right valve.

Hamilton group. Madison, Co., N. Y.
Fig. 14. A right valve, somewhat broader in the anterior portion.

Hamilton group. Schoharie Co., N. Y.
Pig. 15. A cast of the interior, preserving the pallial line and some of the surface striae along the base.

Hamilton group. FSdUmham, N. Y.
Pig. 16. A small left valve.

Hamilton group. Jefferson, Schoharie Co., N. Y.

PLATE XLVIl— Continued.

Ndculites TRIQUETEK.
Page 3S6..
See PUte 93.
Fig. 17. A cast of a left valve which i.s unusually acute at the t)Ost-inferior extremity.
Figs. 18-22. A series of specimens pi-esentiug the usiuil characters of the species.
Fig. 23. A caat of a lefl valve showing cituuilations on the binge-line.

Hamilton group. Cumberland, Md.
Fig. 24. A gutta-percha impression from the preceding, enlarged to two diameters.
Kgs. 2&-'i8. A series of specimens presenting some variations from the typical forms.

.■«i«te »mVu» aiii >|i NuCCLITES NySSA. Ma9 »rfT .1 .^

Page 328.
Vt||4l<ni'W>. Lefl and right valves.

Hamilton gi-oup. Bighteen-mile creek, N. T.

LeDA DIVEK8A.
Page 329.
Figs. 31-37. A series of figures showing variation in form and size, enlarged to two diameters.

' LeDA BREVIROSTBI8.

Page 329.
Figs. 38-41. A series of ligures illustrating the varieties of form, enlarged to two diameters.

Iiiiiitaii ml'

Leda ROSTELLATA.
Page 330.
Figs. 42-46. Present the usual varieties of form in this species. The figures are enlarged to two diameter^.
Fig. 47. A right valve, enlarged to three diameters.

Hamilton group. Pratt's falls, iV. F.

..^.,,1 i... -.„... ..,:,r,.i„„ .„iv„„;-. Leda obscura.

Page 331.
Fig. 48. A right valve, enlarged to two diameters.

Hamilton group. PiUtonham, N. Y.

Leda PANDORIFORMIS.
Page 332.
Fig. 49. A cast of a right valve.

Pig. 60. A gutta-percha impression from the preceding showing the characters of the hinge.
Waverly group. Newark, Ohio.
. >'.iiti -fiij ]|noi« «rua trwHini wit \o »u

NUCULA tJMBONATA.

Page 321. iftollUn /a

Figs. 51, 52. Left and caHinal views of a ca.st. niiiian

Chemung gi-oup. Maiixfield, Pa.

SoLEMYA (JaNEIA) VETU8TA.
Page 463.
See Plate 94.
Figs. 63-£5. Right, left and cardinal views of a characteristic specimen.
Hamilton group. Near LouisviUe, Ky.

P alae ontology NY.VolV.

Upper Helderberg &: Waverly Groups

PlatelLVn.

O.S.Simpsai.. u«i

PLATE XL VIII.

PaL^ONEILO CONSXUICTA.
Page 333.
See Plate 51.
Figs. 1-3. Three right valves of somewhat diffei'ent proportions.
Hamilton group. Central New Yin'k.
4, 5. Two right valves.
6. Cardinal view of a cast of the interior.

An enlargement of a specimen retaining the valves in conjun<^tion.

Hamilton group. BeUona, Yates Co., N. T.
A left valve enlarged showing the crenulations of the hinge-line.

Hamilton group iShttre of Cayuga Jake, N. Y.
A cast of a left valve, enlarged to two diameters.

Hamilton group. Near Cumberland, Aid.
A gutta-percha impression from the jireceding, showing the chai-acter of the interior, enlarged.
An enlargement of the surface from the specimen tig. S.

A cast of the interior of a left valve showing muscular impressions and qrejiulated hinge, enlarged.
Hamilton group. Pultonhain, Scholiarw Co., N. Y. ihiilinK:!

13. A partial cast of a right valve showing the crenulations of the hinge, and preserving the shell and
markings along the pallial line, enlarged.

Hamilton group. Bear's gulf, ScJwharie Co., N. Y.

14. A cast of two valves in conjunction showing the muscular scars and hinge crenulations, enlarged.
Hamilton group. Near Ouiiiberland. Md.

15. An enlargement of the hinge from the specimen fig. 9.

16. A cast of a small individual, somewhat more nasute at the posterior extremity than usual.
Lower Chemung group. Near Ithaca, N. Y.

-K ,Te .egi'l

Figs.

Fig.

Fig.

Fig.

Fig.

Fig.
Fig.
Fig.

Fig.

Fig.

Fig.
Fig.

7.

8.

10.
11.

12.

PLATE XLVIU— Continnoil.

Pal^oneilo oonsthicta, var. flexuosa.

PageSU.
Figs. 17-30. A aeries of specimens illustrating- this variety of form.
Lower Chemung gi-oup. Nvar Ithma, N. V.

Pal.*;oneilo plana.

Figs. 21-23. Three valves preserving the surface markings on the body of the shell and showing the crenu-

lations of the hinge, enlarged.
Fig. 34. A cast of the interior showing the crenulations of the hinge, enlarged.

Hamilton group. Tinker's falls, Orunidaga Co., A'. Y.
Fig. 25. A cast of the interior of a left valve preserving muscular imprints and hinge crenulations, enlarged.

Hamilton group. Butternuts, Ot.sego Co., N. Y.
Fig. 26. A giitta-per(;ha impression of the preceding, enlarged.
Fig-. 27. A cast of a left valve faintly showing the surface striae and the anterior muscular scar, enlarged.

Hamilton group. Shnre, of CanandaifftM lake, JV. Y.
Fig. 28. A left valve pi-esenting a slight variation in form, preserving the surface striae and showing the
crenulations of the hinge, enlai-ged.

Lower Chemung group. Ithaca, N. Y.

Pal.«;oneilo maxima.

Page 335.
Figs. 29, 30. Two left valves presei-ving the surface striae.

Hamilton group. Schoharie Co., N. Y.
Pig. 31. The right side of a cast of a specimen showing the large posterior muscular scar.

Hamilton group. Schoharie Co., N. Y.
Fig. 32. A left valve showing an unu.sual elevation of the umbo from compression.
Fig. 33. A right valve showing a greater height than usual.

Hamilton group. FHdtonham, N. Y.
Fig. 34. The cardinal view of the specimen fig. 31.
Fig. 35. An unusually short and broad right valve.

Hamilton group. Shore of Cayuga lake, N. Y.
Fig. 36. The left side of a specimen preserving the two valves in conjunction.

Hamilton group. Shore of Cayuga lake, N. Y.
Figs. 37, 38. Enlargements of hinge structure. The crenulations are erroneously represented, especially in
fig. 37.

Pal.«;oneilo elongata.

Page 345.
See Plate 93.
Fig. 39. A left valve showing the fine striae of growth, enlarged to two diameters.
Chemung group. Philipsburgh, N. Y.

nmMmiLirtDsr a tEsmBsiisr© ©simisiFg ,

Palaeontology NY.Vol V.

( NUCUI.ID^. )

Plate ILM,

OX . Siropaon. d^ .

PLATE

XLIX.

Pal^oneilo tenuistriata.

Page 33B.

See Plate 93.
Fig. 1. A light valve.

Hamilton group. Shme of Seneca lake, N. Y.
Figs. 2, 3. Left side and cardinal view of a siiecimen of ordinary proportions.

Hamilton group. Pratt's falls, Onondaga Co., N.T.
Fig. 4. A right valve.

Hamilton group. Shore of Skaneateles lake, iT. T.
Fig. 5. A left valve, proportionally somewhat longer than the preceding.

Hamilton group. Shore of Skaneatdes lake, N. Y.
Fig. 6. A specimen i-etaining both valves, showing the surface markings and crenulations of the hinge.

Hamilton group. JPra*Vs falls, Oiunidaga Co., N. Y.
Fig. 7. A right valve presei'\ing the surface markings and showing the crenulations of the hinge.

Hamilton group. Pratt's falls, Onondaga Co., N. Y-
Fig. 8. A right valve similar to the preceding. ■ j. .

Hamilton group. Shore of Cayuga lake, N'. Y.
Fig. 9. An enlargement of the surface from the specimen fig. 2.
Fig. 10. A cast of the interior of a left valve, showing the muscular scars and ci-eniilated hinge.

Hamilton group. Shore of Lake Erie, N. Y.
11. A cast of the right side of a specimen retaining both valves, showing muscular scai-s, pallial line
and ci-enulated hinge. The two valves ai-e slightly displaced, making two lines of crennlationB.

Fig.

Figs. 12, 14. Two specimens which are proportionally wider th.an the prevailing fiinns

Hamilton group. Near Cumberland, Md., and shore of Seneca lake, N. Y.

.A«0>n-? <>JIM/<X*.JA.M

■J <^ J >i; I ii'tj J'"

.quOT^ -yuuin

}%.

PLATE XLIX— Continued.

Pal^eoneilo FECUNDA.

Page 3Se.
Figs. 13, 15-17. Figures illustrating the usual forms in this species.
Fig. 18. A right valve of shorter form.

Hamilton group. Near Ouinberland, Md.
Fig. 19. The right .side of a cast of the interior, showing the muscular scars, pallial line and ci-enulated

hinge. Hamilton gi-oup. Near Cumberland, Md.
Fig. 20. The left side of a specimen similar to the preceding.

Hamilton group. Near Cumberland, Md.
Fig. 21. A gutta-percha impression from the 8})ecimen fig. 20.
Rg. 22. An enlargement of a part of the hinge, from the pi"eceding.
Fig. 23. An enlargement of the surface strite, from the specimen fig. 18wi-j iii>jlii
Fig. 24. The canlinal view of a cast of the interior, showing the ci"enulated hinge and muscular scars.. j,'|

Hamilton group. Near Cuml)erUind, Md.

PAL.EONEILO MUTA.

■.Villi! ■':)! t.l HlloitBiun-'

PBg« 337.

Figs. 25, 26. Two valves presenting the oi-dinary form of the smaller individuals.

Hamilton group. Bellona and shore of Canandaiffua lake, N. Y.
Fig. 27. A left valve of more elongate form.

Hamilton grpu];). Shore of Seneca lake, N . Y.
Fig. 28. A right valve.

Hamilton group. Shore of Canandaigiui lake, N. Y.
Figs. 29, 30. Left and right valves of large individuals.
Fig. 31. A left valve of unusually short fonu with the concentric lamellse very strongly developed.

Hamilton group. Shore <f Skaiieateles lake, N. Y.
Fig. 32. An enlargement of the surface, from the preceding.

PaL^ONEILO FIL08A.
Page 343.
Figs. 38-38. A series of right and left valves preserving the usual form of this species.
Lower Chemung group. Near Ithtua, N. Y.

%

Palaeontology NY.Voiy.

Plate Plate XLIX.

O.B . Simpson, d^ .

PLATE L.
Pal^eoneilo emarginata.

•. ■; .^-^. Page 338.

Figs. 1-6. A series of right valves showing- the gradations in size and the prevailing oharactei-s of the
species.

Hamilton group. Onondaga, Cayuga and Schoharie Co's, N. Y.

Figs. 7-10. A series of left valves. i > i / >-i

Hamilton group, i. ,/. i /:\ I I /. iKllA/' :i.'./ ' \
Fig. 11. A right valve of a small individual enlarged to two diametei"8.
' Lower Chemnng group. Ithaca, N. Y.

Pal^oneilo BISULCATA.

I'age 344.

Figs. 12-14. A right and two left valves enlarged to two <liameter8.
Chemung group. Near Elmira, NT. '

PaL.A;0.\E1L0 PERPLiiNA.

I'age 339.
See Plate 93.
Figs. 15-18. A series of left valves, sho\yi)ig gradation in size and vai-iation in form.

Fig. 19. An enlargement of the left valve of an individual with the umbo cut away, showing the crenulated
hinge.

Hamilton group. Ludhrwville, N. Y.'"
Fig. 20. A specimen retaining the two valves in conjunction.

Hamilton gi-oup. liear'sgidf, tichoharle Co., N. Y.
Fig. 21. A large right valve.

Hamilton group. Bear's gv,lf, Schoharie Co., N. Y.
Fig. 22. A specimen retaining both valves in conjauction.

Hamilton groiij). Btnr'fi gutf, SchoTinrif C"., N. Y.

Pai..eoneilo auata.

I'atrc m.
Fig. 23. The right side of a specimen retaining the two valves in conjunction.
Hamilton gi-oup. 'Near Norwich, Chenaiiip Co., N. Y.

P.iL.EOXlrtLd iltEVI.S. *■ ' ■''■*

rage 342.
Figs. 24-30. Natural ca-sts of the interior of right and left valves, presenting the general form of the fossils
and showiTig the anterior muscidar scai\

Chemung grouj). Franklin, Delaware Co., N. Y. ' Fig. 30 from Philipsbwrgh, N. Y.
Fig. 31. A specimen pi-eservang the surface markings.

Chemung group. Philipuhurgh, N. Y.
Fig. 32. A small specimen preserving the surface mai-kiiigs and showing the crenulations of the hinge.

Chemung group. Phili-pKbnrgh, N. Y.
Fig. 33. A cast of a right valve showing mu.scular sc'ars.

Chemung group. Franklin, Delaware Co., N. Y.

:'P5i;S

Pt^ATE I.r-Continued.

Pal^oneilo ATTENUATA.

Paite 34&
Fig. 31. A cast of the interior of a left valve.

Waverly p-oup. lAcHng Co., Ohio.
Fig. 35. The interior of a left valve from a gutta-percha impi-es,sion of the preceding.
Fig. 36. An enlargement of the same.
Fig. 37. A small individual of this species.

Waverly group. Newark, Ohio.
Fig. 38. The cast of a right valve of medium size.

Waverly grouj). Newark, Ohio.
Pig. 39. A cast of an unusually large left valve.

Waverly group. Newark, Ohio.

Paljeoneilo TRUNCATA.

Page HI.
Fig. 40. A small specimen retaining the shell and showing the surface markings.

Waverly g^-oup Bagdad, Ohio.
Pig. 41. A lai-ge right valve of this species.

Pal^eoneilo SULCATINA.

Page 347.
Fig. 42. A left valve.

Waverly group. Licking Co., Ohio.
Fig. 43. A cast from the impres.sion of the exterior, showing the character of surface strise and an unusual
truncation at the post-inferior exti-emity.

Waverly group. Newark, Ohio.
Fig. 44. From a gutta-percha impression of the natural mould. , , , li

Waverly group. Licking Co., Ohio.
Fig. 45. A cast of the interior of a right valve, showing muscular scars and crenulated hinge-line.

Waverly gi"oup. Licking Co., Ohio.
Fig. 46. A gntta-pereha impression from a right valve of this species.

Waverly group.jj \Richfield, Ohio.

Palaeontology NYVol V.

Plate L.

^>.£ 'iilbpA'JS. dri

i

PLATE LI.

Mackodon Hamiltonkk. l,

Pa^ 349.

Figs. 1-4. A series of ri^t valves, showing gradation in size and some slight variation in form.
Fig. 5. A specimen preserving the two valves in conjunction with the test mainly removed.

Hamilton group. Shore of Oanandaigua lake, N. Y.
Fig. 6. A left valve enlarged to two diametei-s.

Hamilton group. Shore of SkaneaUies lake, N. Y.
Fig. 7. A similar form from the Waverly group of Bedftrrd, Ohio.
Fig. 9. A cardinal view of a cast.

Hamilton group. Shore of Caynga lake, N. Y.
Fig. 10. A left valve of an unusually large individual. , ,'.j

Hamilton group. Near Cumberland, Md. ,,j-.|

Macrodon ovatus.

Page 381.
See Plate 03.
Fig. 8. A loft valve, natural size.

Wavei'ly group. Cfrantdltf, Ohio,

M.\CRODON ChEMUNGEN8I«.

I'ajte CiO.
Pig. 11. A cast of a small left valve.

CheraOng group. Near Uimira, N. Y.
Fig. 12. A large individual.

Chemung group. Near Meadville, Pa.
Fig. 13. A right valve.

Chemung group. Near Elmira, N. Y.
Fig. 14. A characteristic left valve.

Chemung group. Near Elmira, N. Y. .>iJ>l

Fig. l.*). A large left valve.

Chemung group. Near Elmira, N. Y.
Fig. 16. The left side of a cast with the umbo cut away to show the hinge; rliaracters. enlarged.

Chemung group. Near MeadvUU, Pa.

m-

PLATK LI— Continued.

PaLvKONEILO CONSTKICTA.
r««e333. l>]
Sec Plate 48.
Vig. 17. A left valve, enUrg«d. ttz/H vriuio

Portanfe group. Near Portland Harbor, N. T.

NUCULA LAMELLATA.
l"agc 3i0.
See PlatcR 45, 93.

V\g. 18. A right valve, enlarged.

Hamilton group. iSkore of Cayriya lake, N. Y.
Fig. 19. A specimen retaining the two valves in conjunction, enlarged.

Hamilton gi-oup. Shore of Cayuga lake, N. T.
Fig. 20. A left valve, enlarged.
Fig. 21. A right valve, enlarged.

Hamilton group. Sliore of Cuytiga lake, iV. Y.

Ptvchodesma Knappianum.

Page ■i.'ii.
Kga. 22, 23. Cardinal views of two specimens.

Figs. 24-2(i. Left and two right valves showing some variation in form.
Fig. 27. An enlargement of one side of the ligainental area.

Hamilton group. Near Lmiiisville, Ky., and Clarke County, Indiana.

Dystaotella telliniformis.

Page 51ij.
Figs. 28, 29. Lateral and cardinal views of a .small specimen.

Coniifei-ous limestone. Canada West.
Fig. 80. A cast of the interior preserving the remains of some concentric undulations. The specimen is
imperfect, and is completed in the figure by comparison with other individuals.
Coniifei-ous limestone. Canada West-
Fig. 31. A cast of the interior of a specimen.

CoiTiiferous limestone. Western New York.

DySTACTELLA SUBNA8UTA.
Page 51:i.
See Plate 95.
Fig. 32. The left side of a specimen showing mu.scular scar and pallial line.
Fig. 33. The right side of a specimen preserving the concentric strise.
Comiferous limestone. Near Louisville, Ky.

Palaeontology NY.Vol V

( AR C 1 D^K . }

Plate LI

J-'^.Handt-'.

KienaiuvUth.

PLATE LII.
Megambonia caruiiformis. ,

r»ge 515.
Fig. 1. A'small individual preserving- the surface striae.

Figs. 2, 3. Large specimens of the left valve preserving in a greater or less degree the surface charactei-s.
Figs. 4, 5. Casts of the interior of the right valve preserving some portions of the shell and the surface

markings.
Fig. 6. A cardinal view of the specimen illustrated in figs. 2 and 5.
Fig. 7. A cast of the interior of a left valve, showing the anterior muscular impression.
Fig. 8. A gutta-percha impression from the preceding.

Comiferous limestone. Clarence Hollow, Brie Co., iV. Y.

Meoalodon cuLCULiiATus, Sowei'by.

Fig. 9. The interior of a left valve, bhowiiig the muscular impression, teeth and hinge characters.
Devonian. Paffrath, Oennany.

Megalomus Canadensis, Hall.

Pig. 10. The interior of a left valve showing muscular scar, teeth and hinge characters.
Guelph. Canada West.
The figs. 9, 10 are given for comparison with the interior of the corresponding, MKaAHBONiA,
since generic identity has sometimes been claimed for these genera.

Palaeontology NY.Vol V

( ARCln.K.)

Plate LE.

Ph-;j-..5t,]i;h

PLATE Llll.

^YASSA KECTA.
PageSSe.
Figs. 1-6. A series of aijecimiMis illiustrating: this species in its gradation of size and modification of fonn.
Hamilton gi-oup. Scho/iaiie Co., N. Y.

Nyassa AKGUTA.

I'ago 354.

Fig. 7. A cast of the right valve of ordinary form, enlarfjed to show muscular impression and cardinal line.

Hamilton group. Pitcher springs, Chenaiigo, Co., N. Y.
Fig. 8. A giitta-jiei-cha impression from the same.
Kgs. 9-11. Three left valves.
Rg8. 12, 13. Two right valv<?s of this species.
Pig. 14. The cast of the interior of a right valve.

Hamilton group. Pratt's falU, N. Y.
Pig. 15. The cast of the right valve showing musculai- scars, pallial line and hinge i;haractei-8.

Hamilton group. Pratt's f alii, N. Y.
Pig. 16. A gutta-pentha imjiression from the preceding.
Fig. 17. A cast of a right valve of an unusually lai-ge individual.

Hamilton group. Otsego Co., N. Y.
Pig. 18. A gutta-i>ei-cha impres,sion from the pi-eceding specimen
Fig. 19. A portion of the hinge of the same greatly enlarged.

Fig. 20. A cast of a right valve, showing a strong anterior muscular scar, pallial line and cardinal folds
beneath the beak.

Hamilton group. Otsego Co., N. Y.

Nyassa slbalata.

PagcSSS,
Figs. 21-25. Right and left valves, showing the usual variety of form, the anterior musculai- scar and
pallial line.

Hamilton group. Schoharie Co., N. Y.
Fig. 26. A smaller left valve which has ilcveloped distinct I'adii upon the jiosterior slope.
Hamilton group. Fultonham, Schoharie Co., N. Y.

JI^2^^3lL^:nj2f ©mm^IF.

Palaeontology NYVolV

NVAHSIDyli .

PlateLin.

- B..'iiui;.Tr;i- de.

rVi^r>"!T'aliih.

%>

PLATE LIV.

GkaMMYSIA BI8ULCATA.

Page 369.

See Plates 56, 93.

Fi(p8. 1-5. Young and medium-sized specimens pi-esenting the usual charactei-s of this fossil.

Figf. 6. A left valve in which the stronger folds ai-e obsolete, pi-esenting characters which are partially

shown in figs. 4 and 5.
Kg. 7. The left side of a large individual preserving the usual characters.

Hamilton group. Madison Co., N. Y.
Figs. 8, 9. Left side and ant«Hor view of a partial cast preserving the natural form.

Hamilton group. Madison Co., iV". Y.
Fig. 10. A specimen preserving the two valves in conjunction.
Fig. 11. The right side of a specimen which has been vertically compressed.

Hamilton grouj). Madison Co., N. Y.
Fig. 12. The right side of a flattened specimen showing the valves retained in conjunction by the hinge

ligament.
Fig. 13. The left side of a smaller individual.

Hamilton group. Fultonham, Schoharie Co., N. Y.
Kg. 14. A specimen preserving the two valves in conjunction.

Hamilton group. Bear's gulf, Schoharie Co., N. Y.
Fig. 15. An unusually large individual preserving the two valves in conjunction with the ligament partially
preserved.

Hamilton group, ffeneseo, Livingston Co., N. Y.
Fig. 16. A specimen preserving Ixjth valves and having an unusually rotund form. See fig. 1 of plate 56.
Hamilton group. FUUmham, Schoharie Co., N. Y.

?IL-iV!MJTTL7rrmW ©m(DWlP.

Palaeontology NY.VolV

( GBAMUnrSID^.

Plate Lff.

Fmrrton fle!

kiem'TnnlUh

PLATE LV.

GrAMMYSIA N0D0C08TATA.

Page 360.

See Plates 56, 57, 96.

Pig-. 1. A small specimen pi-eserving both valves and showing the characteristic ornamentation.

Hamilton gi-oup. Madison Co., N. T.
Fijfs. 2-4. Anterior, posterior and cardinal views of a specimen vertically compressed.

Hamilton group. Madison Co., N. Y.
Figs. 5, 6. Left side and cai-dinal view of a small individual, showing the surface ornaments in a very satis-
factory manner.
Figs. 7-9. Left, anterior and posterior views of a large specimen which is vertically compressed, making
the valves much narrower and deeper than natural.

Hamilton group. Madison Co., N. Y.
Fig. 10. A ft-agment of a left valve pi-eserving the surface ornaments.

Hamilton g^roup. Shore of Cayuga lake, iV. Y.
Pig. 11. An enlargement from the surface of the preceding.

IlI^SfilllL'n'rrisg- ©mmwiF,

Palaeontology NYVol V

( (IRAMMYSID^ )

Plate LV.

i 11 FOmrrlon dd

awiiLtoi.,liti-..

PLATE LVI.

GrAMMYMA BISi;i,CATA.
Page 36».
See Plates 54, 93.
Fig-. 1. A left valve of a large individual of broad form.
Hamilton group. Ludlowville, N. Y.

GrAMMYSIA N0D0C08TATA ?
Page 360.
See Plates 55, 57, 96.
Figs. 2, 3. The right and left sides of a sjwcimen which is obliquely compressed and distorted.
Hamilton group. FuMonham, Schoharie Co., N. Y.

Grammysia magna.

Page 362.
See Plate 57.
Fig. 4. The right side of a partial cast of the interior.

Hamilton group. Madison Co., N. Y.
Fig. 6. The right side of a specimen pi-esei-ving the two valves in conjunction.

Lower Chemung group. Ithaca, N. Y.
Fig. 6. A large left valve which is a partial cast of the interior, presei-ving only the finer striae.
Fig. 7. A partial cast of a right valve preserving on the middle and anterior portions the stronger un-
dulations.

Hamilton g^roup. Schoharie Co., N. Y.

Grammysia erecta.

Page 363.
See Plate 57.
Fig. 8. An imperfect right valve pi-eserving the umbonal and anterior portion.
Hamilton group. Pultonham, Schoharie Co., N. Y.

Palaeontology NY.VolV

( GHA.MMVSln.^■. I

Plate LVI

J-H-r-nicrton id

iilTtTLtOJi, lull

PLATE LVll.
Gkammysia alveata.

Page 370.
See Plate 60.
Fig. 1. Cardinal view of a specimen vertically compressed.
Hamilton group. Chenango Co., 2f. Y.
Fig. 2. The ventral view of a specimen vertically compressed.
Hamilton gi-oup. Madison Co., N. Y.

GrAMMYSIA CIRCULARtS.

Page 36i.

See Plate 58.

Fig. 3. Two valves in conjunction which have been partially denuded of the shell, showing muscular scare

and pallial line.
Fig. 4. The i-ight side of a cast of the inteiior showing muscular scars and pallial line.
Fig. 5. Anterior view of the same specimen.

Hamilton group. Schoharie Co., N. Y.
Fig. 6. Anterior view of a specimen somewhat vertically compi-essed.
Chemung group. Ithaca^ N. Y.

Gkammysia nodocostata.

Page 3B0.
See Plates 55, 56, 96.

Figs. 7, 8. Cai-dinal view and right side of a large individual.
Hamilton group. Madison Co., N. Y.

Gkammysia magna.

Page 362.
See Plate 56.
Fig. 9. View of a crushed specimen, showing the escutcheon and ligamental ai-ea with a portion of the
ligament.

Hamilton group. Pompey, Onondaga Co., N. Y.

Gkammysia kkkota.

Page 3«8
See Plate 56.
Fig. 10. The umbonal and anterior portion of a right valve.

Hamilton group. Near Bear's gnlf, Sc-Jutharie Co., iV. Y.

nyvMniLiTCDa' (a siiiiEsa'Jit*jL& LSBisimpg ,

P alacontology N YVol V

I t;iiA.\iMY«in^c.|

Plate LVn.

J K Emcr!.on del

RiemaTin.litli.

\

PLATE LVIII.

(IkAMMYSIA ELLll'TICA.

I'ajfc sue.
Pig. 1. A Hiiiall left valve of umisiially i-otuiiil form, i-efeiTcd to this species with some doubt.

Lower Chemung gi-oup. Ithaca, N. Y.
Fig. 2. A left valve of the usual form and proportions.

Chemung group Alleghany Co., N. Y.
Fig. 3. A right valve similar to the pi-eceding.

Chemung group. Philipsburgh, N. Y.
Fig. 4. A right valve.

Lower Chemung gi-oup. Ithaca, N. Y.
Fig. 5. A left valve similar in fomi to fig. 1, and also referi-ed with doubt to this sjiecies.
Pig. 6. The opposil* side of the pi-eceding, showing the escutcheon and hinge.

Chemung group. Philipsburgh, N. Y.
Fig. 7. The left side of a sj>ecimen.

Chemung group. Maiutfifld, Pa.
Figs. 8, 9. Two left valves of young indiviiluals.

Chemung group. Philipsburgh, N. Y.
Fig. 10. A large right valve.

Chemung group. Manafield, Pa.
Fig. 11. The anterior portion of a large right valve of unusually erect fiirni.

Chemung group. Mansfield, Pa.
Fig. 12. The hinge of a right valve showing the ligamental area and cardinal fold.

Chemung group. Mansfield, Pa.

GkAMMYSIA CIECULARI8.

Pa^e 364.

See Plate 57.

Fig. 13. The left side of alai-ge individual. The sjiecimen was found in the town of Nichols, Tioga Co.,

N. Y. Its precise horizon is unknown.

cEMSSxawss"© ©mcDwip.

Palaeontology NY.VolV

( GBAMMYSID^C

PlateLVia,

J H Bmerlon del

Riemanivluh

PLATE LIX.

Gkammvsia pk>ecuusou,

Page 376.
Fig. 1. The right side of a ppecimen preserving both valve.s.
Schohaiie grit. Schnlmrle, N. Y.

Grammysia skcunda.

Page 376.
Figs. 2, 3. Cardinal view and right side of a specimen.

Comiferous limestone. Clarence ffollme, N. ¥.

-■ -yiirtAife'

GkAMMY8IA constricta ?
Page 3T7.
See Plate 78.
Figs. 4, 5. Right and left sides of the same specimen, refei-red to this sjiecit* with iloiibt.

Fi-om a compact limestone in the Mai-cellus shale. iVieor Buffalo, iV. Y.

Grammysia lirata.

Page 371.
Fig. 6. Left side of a small specimen.

Hamilton group. Schoharie Co., N. Y.
Fig. 7. A cardinal view of a .specimen holding the two valves in conjunction.
Fig. 8. A larger indiWdual.

Hamilton grouj). Schoharie Co., N. Y.
Fig. 9. The left side of an individual retaining the two valves in conjimction.
Fig. 10. Cardinal view of a larger 8i)ecimen.

Hamilton group. Schoharie Co., N. Y.
Fig. 11. A right valve of another individual.

Hamilton group. Schoharie Co., N. Y.
Fig. 12. A cardinal view of a specimen.

Hamilton group. Schoharie On., N. Y.

I'LATi;: LIX— Coiiltiiucd.

GUAMMYSIA CONSTRICTA.

Pago S77.

See Plate 78.

Vig. 13. The rig^ht fiiile of a small individual i-etaining the i)roi)er fonn of the shell.

Pig. 14. The right valve of another individual, the anterior end shortened by compression in an ubliqu6
ilii-ection.

Hamilt4>n jn"<'"P- Sliore of Seiieea lake, N. Y.
V\g. 15. A left valve, the anterior end shortened by compi-ession.
¥\g. 16. A right valve retaining the nonnal form.

Hamilton group. Schoharie Co., N. T. f •

Fig. 17. A small left valve somewhat shortened anteriorly by compi-ession, the surface presemng a few ot
the radiating strite, enlarged to two diametei-s.
Hamilton grouj). IjudUnpville., N. Y.
Fig. 18. A cai-dinal view of a specimen of ordinary dimensions.

Hamilton group. Shore of Canandaigna lake, N. Y.
Fig. 19. The right side of a specimen i-etaining both valves, the anterior end greatly shoi-tened by com-
presedon, the surface preserving the radiating stiise, enlarged to two diameters.
' ' Hamilton group. Schoharie Co., N. Y.
Fig. 20. An enlargement of the surface showing the pustulose character, from the specimen fig. 18

Grammysia obsoleta.

Page 366.
Figs. 21-23. Left side, anterior and cardinal views of a specimen which is vertically compressed.

Hamilton group. Oazeniovia, N. Y.
Fig. 24. The interior of a left valve showing the cardinal area and elevation of &e umbo.

Hamilton group. Svholuirie Co., N. Y,
Fig. 25 A specimen retaining the two valves in conjunction, each one of which is somewhat nan-owed by

compression.
Fig. 26. A left valve jireserving nearly the noimaJ propoi-tions. , .

Hamilton gi-oup. Pratt'.i falU, N. Y. .I«h1m /rimi ciili'riiK
Fig. 27. A left valve of a sjx-cimen somewhat > compressed and showing thft chaj-acteristic fold and sinus
np<m the anterior end of the valve. ii-.iiilKin'. A .L'l .yyi

Hamilton group. Schoharie Co., N. Y.

Palaeontology NY.Vol V

( GHAMMYSIID.t: . )

Plate LK.

J. a Bmertor.

-J'\

PLATE LX.
Gkammysia alveata.

I'agc 3T0.
See Plate 57.
Fip. 1. The left side of a specimen retaining' both valves.

Hamilton group. Madison. Co., N. Y.
V\g». 2-4. Left side, antei-ior and canlinal views of a specimen retaining its natural i>i-(>iioi-ti<)ns.

Hamilton group. SclioTmrie Co., N. T.
Fig. 5. Cardinal view of a specimen which is vertically compressed.
Fig. 6. The right side of a specimen pi-eserving nearly the normal fonn.

Hamilton group. Madison Co., N. Y.
Fig. 7. The cardinal area of a left valve.

Hamilton group. Otsego Co., N. Y.
Fig. 8. A left valve preserving the normal form.

Hamilton group. Madison, Co., N. Y.
Figs. 9, 10. Left side and anterior end of a large individual with sharp and distinct C(mcentnc fold

Hamilton group. Schoharie Co., N. Y.
Fig. 11. The left side of a compressed specimen fig. 1 of plate 57.

j'g^»\syirH!L"j'EJSf ©lamwiF.

P alae ontology NY Vol V

( GH^UIMYSIDvE

Plate. LX.

'. Hmrrlcfn del

vt^rjihih

PLATE LXI.

(il{AMMV.SIA AKCUATA.

Page 373.
See Plates 63, 93.
Fig«. 1-5. A series of valves pi-esenting the usual chai-actei-s of the species.
Pigs. 6, 7. Left side and anterioi- views of a specimen vrhich is vertically compressed.
Fig. 8. The right valve of a large indivi<lual.

Hamilton group. iSchottarie Co., N. Y.
Fig. 9. Ciinlinal view of a specimen vertically compressed, giving an extreme angularity to the uinlional
slope.

Hamilton group. •S'Aore of Canaiulaigua lake, N. Y.

f <ft

Gkammysia subarcuata.

rage 375.
See Plate 93.

Figs. 10-12. A series of left valves of the visual character.

Figa. 13-15. Larger individuals of the same species.

Figs. 16, 17. The left side and cardinal view of a compi-essed specimen.

Chemung group. Niar Elmira, N. Y.
Fig. 18. A cardinal view of a compres-sed specimen.

Lower Chemung gi-oup. Ithaca, N. Y.
Fig. 19. A caiilinal view of a crushed specimen.

Lower Chenuuig group. Ithaca, N. Y.
Fig. 20. A cardinal view of a crushed specimen.
Kg. 21. The right side of a verticjilly compressed specimen.

Chemung gi-oiip. Near Blinira, N. Y.
Fig. 22. An enlargement of the sui-face striae on the i^oat-cai-diiial slope of the siiecimen tig. 19.

Grammysia undata.

Pago if7».
See Plates 64, 93.
Fig. 23. A small left valve.

Chemung gi-oiip. Near Pananta, N. Y.

i'LATK LXl— CoDllnaeU.

Grammysia communis.

Page :I7».
See Plate 93.

Fig. 24. A right valve.

Chemung group. Near HobbietjUle, N. 7.
Fig. 25. A left valve proportionally l)roa<ler than the jjreceding.

Chemung group . Near HoWieville, N. T.
Fig. 26. A left valve of elongate form.
Fig. 37. A left valve of a smaller specimen.

Chemung group. Cattarauffus Co., N. Y.
Fig. 28. A large left valve.

Chemung group. Cattaraugun Co., N. Y.

Grammysia IIannibalensis.

I'llKe iWl.
Fig. 29. A right valve.
Fig. 30. The left side of a sjiecimen.

Waverly gi-oup. Cuyahoga Co., Ohio.
Fig. 33. A right valve.

Choteau limestone. Hannibal, Mo.

Grammysia plena.

.II'Hl

. I'^go 3S2.
Fig. 31. A left valve.

Yellow sandstone. Burlington, Iowa.
Fig. 32. A left valve of shorter form, showing the (characteristic plication on the post-<cttriliiiiil slope.

Yellow sandstone. Burlington, Tinoa.

Palaeontology NYVoiy

( GRAMMY SIID.E . )

Plate La.

I

■ il iir.ert.on del

IM.ATK LXll.

(lUAMMYSIA (Si'HENOMYA) CUNEATA.

I'llgO 3*!.

See Plate. 93.
V'lg. I A fsinall rig'ht valve.

Hainillon {ffoiiii. liinr'a ijnif, jStclmfiar'n: Co., N. Y.
Kiff 2. A cjinlinal view of a small iiiilivuliial.

Hamilton {fi-oiii). Xmr Apulia, N. Y.
V\g. 3. The rig-lit valve of a liir^ imrnidual somewhat vertically comin-esaeil.

Haiiiiltoti f,'i-oiii). Ntw Berlin, N. Y.
}?\g. 4. The left «ide of a crushed siiecimeii.
Fijf . 5. The light side of the same showing' the short hiiig-e line.
Kig. •!. The Hght side of a comjiressed specimen,
rig. 7. The right side of a specimen similar to the jireceding-.
Fig. 8 A caiilinal view of a speciiiuMi from a gutta-ixii-cha impression in the natural moidd.

Uamiltoii groviji. /Silii>?iarie Co., N. Y.
Fig. 9. ('anliiial view of a large indiviihial which hiun been vertically crushed.

Hamilton group. OUcyo Co., JS. T.

Grammv.sia 0IX)B0SA.

I'agc 372.
Fig. 10. The light side of a small individual.

Hamilton gi-oup. Leon/irfljitnlle, N. Y.
Figs. 11, 12. I^Kift side and cardinal view of a si)ecimen somewhat compi-essed.

Hamilton group. HamilUm, N. Y.
Fig. 13. Anterior view of the specimen fig. 10.
Fig. 14. Anterior view of the 8i>ecimen tig. 11.
Fig. IS. Anterior view of a specimen with the valves conjoined along the hinge and sepai*ate<I below.

Hamilton group. Hamilton, N. Y.
Fig. Hi. A view of the right valve of the pn^ceding specimen.
Fig. 17. A carilinal view of the same specimen.
Fig. 18. The right side of a specimen pr<^s<!rving both valves.
Fig. IS. The leftside of the same specimen, th(! valve distorted by pressure.

Hamilton group. Near HamilUm, N. T.

??uvs^niL'g(D5S' ©3mmwiF=

Palaeontology NYVolV

( C ABDIOMOHPHID.K )

Plate L;

t^.>c

18

J Ji Bmcrton M

PLATE LXUI.
Gkammvsia |{i:lla tl i.a.

Page 367.
Kig. 1. A small bliMik of shale j)ri;«iTviiig- two valves, pi-obtiVily of the same indivicUial.

Haiiiiltdii jri'oiip. York Center, LUHuysUm Co., N. Y.
Figs. 2, 3. The two valves eulai-g-ed.

GkAMMV.>5IA ZONATA.
rage sn.
Pig. 4. A left valve, enlwged.

Hamilton fj-roup. Sthoharie Co., N. Y.
Fig 5. A specimen i-etainin(r both valve« in conjimction. In the left valve the lidge on the uniboiial
slope is due to a fi-iicture and exaggerated in the figure

GkAMMYSIA AK( I ATA ?

Page 373.

See Plate-s 61, 93.

Fig. 6. The left valve of a caHt of the interior. The ridge on the unibonal slope is probably due to a
fra<;ture in the shell.

Hamilton group. Eighteen Mile creek, N. Y.

Gram-mysia EUIOPIA.

Pago 368.
Fig. 7. A right valve. The umbo M represented as too nari-ow in the fif.'-iire, and the aj)pai-ent furrow on
the post-cai-dinal sIhjm; is a gentle fold.

Hamilton grou]). Shore of Seneca lake, N. Y.
Fig. 8 A large right valve.

Hamilton group. Sliore of Canandnigua lake, N. Y.

Ed.MOMJIA ? TKNUISTUIATA.
Page 893.

See Plate 93.
Fig. 9. An imperfect right valve. jaBj^i^j

Chemung group. Near Elviira, N. Y. ^^B;
Fig. 10. An enlargement of the surface showing the concentric lines of growth and radiating strije.

I'l.ATK tJilll— Contiimea.

EUTHYDKSMA SUIJTKXTILE.

Pago 3t».

See Plato 93.

Vigs. 11-13. Left valves of this speeie.s.

Portage gi-oup. Jjoke Brie shore, Chautaiiqua Co., N. Y.
Ki(f. H. A right valve.

Fig. 15. An enlargement of the siirfiu-e, incorrectly representtjd.

Fig. 1*5. A left valve of an old individual pi-eseuting strong obliciue folds on the middle of the shell.
Portjige gi"oup. Lake Erie shore, Chautauqua Co., N. Y.

8cHIZODU8 UEGRNER.
Page 468.
Fifir. 17. A left valve. The umbo and beak are too much elevated in the figure.

PaKACYCL.VS itOTUNDA.
Page 444.

See Plate 95.
Fig. 18. A right valve.

Chemung group. Bnxnne Co., N. Y.
Fig. 19. A left valve.

Chemung group. Browne Co., N. Y.

SCHIZODUS PATULUS.

Page 457.
Fig. 20. A left valve.

Chemung gi-oup. Near Mansfield, Pa.

PALJ'iOMYA OBLONOA.
Page 509.
Fig. 21. A <-a8t of the interior of a left valve showing muscular imprints and strong concentric undulations
of growth.

Hamilton group. Schoharie Co., N. Y.

amsaniLirsss" ^ 'smmw^.s^ ©si^isips .

Palaeontology NY Vol V

( CARDIOMORPHID,*: )

Plate LM.

J H cjnericr d--^

S;->:nann,hili.

PLATE LXIV.

SaNGUINOLITES (?) UNDULATUS.

Page 508.
Figs. 1, 2. Right and left valves presenting some differences.
Chemung' group. Cattarauffus Co., iV. ¥.

SaNGUINOLITKS (?) 8UBTRUKCATUS.

Faffe 508.
Fig. 3. A left valve.

Chemung group. Clierry creek, Chatitmiqua Co., N. Y.

Fig. 4. A right valve. The anterior end as represented is too broad.

Chemung group. CoivMwango, Cattaraugus Co., N. Y.

GrAMMYSIA ? 8UBNASUTA.

Page 507.
Figs. 5, 6. Lefl valves.

Chemung gi-oup. Near Oleau, N. Y.

EUMONDIA RHOMBOIDKA.

Page 386.

See Plates 75, 95.
Fig. 7. A left valve.

Chemung grouj). Near iSalatuanca^ N. Y.
Fig. 8. A right valve.

Chemung group. North of Panama, N. Y.

Edmondia Philipi.

Pajte 387.
See Plate 95.
Fig. 9. A lefl valve of short and broad form.

Chemung grouj). HobbievUle, N. Y.
Fig. 11. A left valve.

Chemung group. I/obbieville, N. Y.
Fig. 12. A li^ft valve.

Chemung group. Connevoango, N. Y.
Fig. 13. A left valve.

Chemung group. Hobbieoille, N. Y.
Pig. 14. A right valve.

Chemung group. Philipghirgh, N. Y.
Pig. 17. A left valve.

Chemimg group. HobbieeUle, N. Y.
Fig. 29. A young individual,

Chemung group. I'hilipslnirgh, N. Y.

^

I'KATK I.XIV— Coiitinuoil.

l*>lJMONDIA SUBOVATA.

i'ago 889.
Si'e Plak- 95.
Vig. 10. A l«fl valv«' (loul)lfully ii'fL'ri-od to this Ki^cies.

Chciniiii^ jfi-oiip. PhUij}sbttrg/i, N. V.
Kijf. 18. A left valve preserving the cliaractfi-i.stic form.

Cbeiniiiig gi-oup. Nobbieville, N. Y.
FijfB. 19, 30. Two rijfht valves.

Chemuiijr (rroiip. Philipxhnryli, N. Y.
Fiff. -•• A nghl valve of inoi-e clciiffate form than usual, and j-eferred Wftt doubt to this species.

Lower Chemung' (jroup. Ithaca, N. Y.
Fig. 26. A large right valve.

Chemung gniup. Hobbieville, N. T.
Fig. 27. A right valve of medium size.

Chemung givup. PhUipslmrgh, N. Y.
Fig. 28. A right valve of a large individual.

Chemung group. PMUpsl>ur(/h, N. Y.

Edmondia obliqua.

Page 388.
See Plate 9.').
Fig. 15. A left valve.

Chemung group. UobMemlle, JV. Y.
Fig. 16. A right valve njferred with doubt to this species.

Chemung group. PhUipshurgli, N. Y. , ,
Fig. 23. A right valve of this species.

Chemung groui). PhUipslmrgh, N. Y.

EUMONDIA BURLINGTONENSIS.
Pago 390.
See Plate g.-i.
Fig. 22. A right valve. The beak and umbo are represented aa too much elevated.
Yellow sandstone. Burlingtim, loxca.

EimONUIA TKANSVEK.SA.
Page 389.
Fig. 24. A left valve.

Chemung group. Qittaraugus Co., N. Y.

P^DMONDIA ELLIPSIS.
Page 395.
Fig. 25. A left valve. The beak is represented as too angular and elevated.
Burlington sandstone. Burlington, loVM.

Gkammtsia undata.

Page 379.
See Plates 61, 93.
Fig. 30. A left valve. ■, -f a,,m,

Chemung grouj). J'ortvUle, JV. i.'

Edmondia ? suBCAHrNATA.

Fig. 31. The right valve of an imperfect specimen.

Chemung group. Near Oleav, ^i Y.

Edmondia depuessa.

Page 391.
Fig. 32. A right valve.

Waverly sandstone. Licking Co., Ohio.

Palaeontology NYVol V

( CARDIOMORPHID.+: .)

Plate LM

^

JV.'.H -V.

Rierr.annh'lL,

'i; ^-.-V*--'

■,-£f r

PLATE LXV. '^^^

Sphenotus tklncatus.

I'age 3!M.
Fig. 1. A small right valve.

Hamilton group. Schofiarie Oo.. N. Y.
Vig. 4. A BpeciiniMi pre.serving both valves. ^ .

Hamilton group, i^chohane Co , N. Y.
FifT. T). A Bmnlli^r imlividual enlarged to two (liamctors.

Hamilton group. Shore of Skiuneal4)l§ii Jake, N. Y.
Fig. 6. A left valve showing unusually strong concenti-ic nndulatitjuB.

Hamilton group. Schoharie ''n., y. Y. it, mjilin

OkTHONOIA ? I'AKVUtA.

I'ase 48-i.

See Plfttp 78.
Figs. 2, 3. Left anil right valves. The fold on the post-cardinal slope is too stfoj^gly r^pjsesented.

Sphenotus arc^;koumis.

^ :P»g« 3B5, , ,/ ;| . -

See PH,te 66.
Fi^s. 7-10. Four right valves showing some vai-iation in fonn and pi-ojwrtSons.
Fig. 11. A left valve. '

Hamilton group. Delphi, N. Y.

8PHENOTU3 CrONBATUS. : lijH sdT

Page'.'fiW.

Figs. I2-H. Three valves jjrcsentiiig the usual charactei-e of tlii.s sjn-cii-s.

UauUltou gi-ouj). SiJwharie Co., N. Y.
Fig. 1."). The right sidt; of a small specimen retaining the valvi-s in conjimction.

Hamilton group. Schoharie Co., N. Y.
Fig. 1 6. A large right valve.

Hamilton group. Schoharie Co , N. Y.
Fig. 17. A large sjM'i-imen with the valves (tonjoined.

Hamilton group. Schoharie Co., N. Y.

PLATE LXV— Continued.
SpHENOTUS 8UBTOKTUOSUS.

Page .'i97.
Pig-. 18. A left valve.

Hamilton group. Schoharie Co., N. Y.

Fijf. 19. A somewhat smaller left valve.

Hamilton group. York, Livingston Co., N. Y.

GoNioPHORA Ida.

Pa«:e 300.
See Plate 42.
¥ig. 20. A specimen preserving both valves.

Hamilton group. Genesee, Livingston Co., N. Y.

Sphenotus solenoides.

Page 398.
Figs. 21-23. lliree small left valves.

Fig. 24. A right valve of medium size.

Pigs. 2.5, 26. Left side and cardinal views of a specimen which is somewhat compressed vertically.

Hamilton group. iShore of Canandaigua lake, N. Y.
Fig. 27. The right side of a specimen presei-ving both valves.

Hamilton group. Bellona, N. Y.
Fig. 28. A large right valve.

Hamilton group. Shore of Canandaigua lake, N. Y.
Fig. 29. An enlargement of the posterior portion of the specimen fig. 22 showing the vascular-like marking!^.

rgUVBEgaiTiEBf ©lEiETDriF.

Palceontology NY.Vol V.

SAXGriXOLITID.+; )

Plate LBf.

O.B . SitRpsoc del .

P^cmanniifh-.

PLATE LXVI.

Sphenotus contractus.

Page 399.
See Plate 94.
Fig. 1. A left valve jireserWng- the shell in part, and showing the antei-ioi muKculai- iuipres-sion.

Cheraiing group. P/iUipxburf/h, N. Y.
Figs. 3, 4. Larger left valves.

Chemung group. Philipsburgb, N. Y.
Fig. 5. A smaller left valve impei-fect at the posteiior extremity.

Chemung group. Eight miles stmtli <if Mayville, N. Y.
Fig. 6. A small right valve somewhat compressed vertically, giving a narrow car<linal slope.

Chemung group. Philipshurgh, N. Y.
Figs. 7-9. Right valves of .specimens showing gi'aJation in size and the muscular scais.

Chemung group. Alleghany Co., IV. 1'.
Fig. 10. A right valve showing a wide post-cjirdinal slope and a rounded posteiior extremity, in which it
differs from the othei-s. . ■' A .0,-.

Chemung grouj). RockinUe, N. T. -~' ~

Fig. 11. The inner side of the right valve fig. tJ oidarged, showing the ligamental area and a narrow gi-oove

beneath the umbo.
Fig. 12. A right valve sho\ving anterior muscular impression.

Chemung group. Near Oleati, N. Y.
Fig. 13. A left valve of elongate form.

Chemung group. Near Olean, N. Y.
Fig. 15. A large left valve imperfect at the anterior end.

Chemung group. Cattarauffu.t Co., N. Y.
Figs. 16, 17. Shorter forms which are referred to this species with doubt.

Chemung group. Cattarattgus Cn., N. Y.
Fig. 19. A left valve doubtfully referi-eil to this species.

Chemung group. Cherry creek, Cattaraugux Co., N. Y.

SpHKNOTUS CLAVULU8.

Puge 401.
Fig. 2. A small left valve.

Chemung group. PhiUpxbiiryh, N. Y.

Figs. 20-26. A series of valves showing the variety of size :ii](l form.

Sphenotls kioii>u.s.

Page 402.
Fig. 14. The i-ight siile of the original specimen.

Burlington sandstone, liurliiujlan, Iirwa.

^■•%.

PLATE LXVI— CoiiUnueil.
SpHENOTUS? ARCDATD8.

Pftgc 400.
Fig'. 18. A catst of a right valve, showing the anterior muwiular impression and pieserving the remains of
stria' of growth.

Chenuing group. iVrtir Paiuniia, N. Y.

SpHKNOTUS FLAVI08.

Pajre 4(i:l.
Figs. 27-39. Left, right ami cardinal views of a speinnuMi wliich hius botMi somewhat compi-es-sed vertically.
Waverly group. Licking Co., Oldv.

Sphenotus valvulus.

Page 4oa.
Fig. 30. A right valve.

Waverly group. Newark, Ohio.

Sphenotus yEolus.

Page 404. m 'K>ii<.i^ti

Figs. 31-34. A series of right and left valves showing some variety of form and aspect.

Waverly group. Ohio.
Fig. 3.1. A canlinal view of the specimen fig. 33, showing the long ligameiital area.

Waverly group. Lirkinf/ Co., Ohio.

SpATIIELLA ITPICA.
Page 407.
Figs. 36-40. Left and right valves showing vai-iation in form and proportions.
Chemung gi"oup. Toinykins and Chemung Co's. JV. T.

Spathella ventkicosa.

Page 408.
Figs. 41. 42. Two left valves.

Burlington sandstone. BurlingUm, Iowa.

Sphenotus akc^fohmis.

Page 395.
See Plates 65, 76.
Pig. 43. A left valve, i-eferred with doubt to this species.

Chemung group. Near Smethport, Pa.

Palaeontology NYVol V

(sANGUINOLITIDvE )

Plate LOT.

O.B. &u&;>aoiL dtl .

.i^iemanalith.-

PLATE LXVII.

CONOCAHDIUM CUNKUS, vai'. ATTENUATUM.

Page 410.
Fig-. 1. A small right valve.

Schoharie grit. Knox, Albany Co., N. 1'.
Fig. 2. A cast of a small right valve.

Schoharie grit. Knox, Albany Co., N. Y.
Fig. 3. A vential view of the cast of the interior of a small specimen.

Schoharie grit. Schoharie, JV. Y.
Fig. 4. Cardinal view of a small individual, i-etaiiiing iiortions of the test.

Strhoharie grit. SchoJtarie, i\'. Y.
Figs. 5, 6. The right valves of two specimens showing simple radii.

Schoharie grit. Schoharie, iV. Y.
Figs. 7, 8. Loft and right .sides of a cast of the interior.

Schoharie gi'it. Schoharie, N. Y.
Pig. 9. The posterior end of a siie<'imeii retaining both valve.s.
Fig. 10. An enlaj'goment of the surface from the .-pecimeii lig. 5.

Fig. II. A ventral view of ii .simall ca.-^t of an interior, showing the furrows left by the thickene<l margins
of the shell.

Schoharie grit. Schoharie. N. Y.

CONOCARDIUM CUNKUS, Viir. NASUTUM.
Page 41U.
Pigs. 12, 13. Ventral and left sides of a small specimen.

Schoharie grit. Schoharie, N. Y.
Figa. 14, 15. Left side and ventral view of a s])eciinen retaining its natural form and showing a duplication
of the radii.

Schoharie grit. Schoharie, N. Y.
Fig. 10. A ventral view of a specimen retaining a portion of the test.
Fig. 17. The right side of a small specimen.

Schoharie grit. Schoharie, N. Y.
Figs. 18-20. The cardinal, left and posterior views of a large individual retaining its noi'mal form and
proportions.

Schoharie grit. Schoharie, N. Y.

I'l.ATK I-XVIl— Continued.

CONOCAKIMUM CUNEt'S.
rage 40a.
.See Platvs H8, <t4.
Fig. 21. The right side of 11 crii.«he(l sjH!cinu'n.
Ki(f. 22. An enlai-yeiiii-iit cf the surface from the jn-eceiling;.

Schoharie grit, l^c/ioharie, N. Y.
Fiff. 23. An iuijierfeft partial cast of ii left valve, showing Ihc !il>sc'iic(' of radii on thf surface of the test,
and the strong radii on the interior of the shell

Schoharie grit. Knox, Albany Co., iV. T.
Figs. 24-26. Ventral views of three 8i>e<nnienH, showing tiie dtiplictation of the radii towai-dsthe margin, and
the extension of the shell beyond the unibonal ridge.
Sohoharie grit. Albany Co., iV. Y.
Fig. 27. The posterior view of a specimen showing the expansion of the shell around the periphery of the

umbonal ridge.
Fig. 29. The ventral aide of a sjiecimen from which the shell is exfoliated.

Schoharie grit. Schoharie, N. Y.
Figs. 30, 31. The left sides of two casts of the interior.
Schoharie grit. Schoharie, N. Y.
Fig. 32. The ventral view of a specimen.

Schoharie grit. Albany Co., N. Y.

CONOOABDIUM CUNEU8, VUr. TRIQONALE.

Page 410.

See Plates 68, 94.

Fig. 28. Ventral view of the original specimen, which is a partial cast of the interior, retaining portions

of the test along the margins.

Corniferous limestone. Canada West.

Palaeontology NY.Vol V

(CARDIID-E.)

Plate Lira.

'"■-■B.fiir.jjB*.-.. .;*:1 ,

PLATE LXVIII.

CONOCARUIUM CUNEUS, Var. TKIGONALE.
Page HO.
See Plates 67, 94.
"Pig. 1. The ventral side of a small siwcimen.
Figs. 4-0. Ventral and cardinal views and right side of a small specimen retaining the shell.

Comiferous limestone. Near Zjouisville, Ky.
Fig. 7. An enlargement of the sui-face from the post-cardinal slope of the pi-eceding.
Fig. 8. An enlargement showing a portion of three radii and the extension of the shell beyond the

umbonal ridge, from the sjwcimen fig. 6.
Fig. 9. Cardinal view of a specimen .showing the surface nwirkiiigs.

Cornifei-ous limestone. Fallx of the, Ohio river.
Figs. 10, 11. Left side! and cai-dinal views of a specimen retaining portions of the test.

Comiferous limestone. Near Loulte'dle, Ky.
Fig. 12. Ventral view of a specimen showing the pedal opening and denticulate<i margins.
Fig. 13. Cardinal view of a ca.-st of the interior, showuig anterior and posterior muscular scars.

Coraiferoiis limestone. Columlnis, Ohio.
Fig. 14. The right side of a spec'inien, preserving portions of the test and showing the extent of the

umbonal expansion of the shell.
Fig. 16. Posterior view of the specimen fig. 12.
•

CONOCAKDIUM OhIOENSE.

Vug 4U.
Fig. 2. The left side of a six'cimen.

Comiferous limestone. Near Louixmlle, Ky.
Fig. 3. The left side of a nearly entire individual, enlarged to two diameters.

Comiferous limestone. Fhlla of the Ohio river.

^f|M^ CONOCABUIUM NOKMALE.

^ I'agc 411.

Figs. 17, IH. The rigli; ; I'ardinal views of a lai-ge partial cast of the exterior of a specimen.

Hamilton group. Ciimlxrland, ild.
Fiir 1!' The right sifle of a caiit of a sm.'illi'r specimen, showing the anterior muscular scar and the tilling
of the foot sheath.

Hamilton group, (iimberland, Md.

CONOCARDIUM EbORACEUM.

Page 11-2.
Figs. 20, 21. Ventral and cai-dinal views of a compressed specimen.
Hamilton group. York, Livingston Co., N. T.
Figs. 22, 23. Ventral view and left side of a small specimen retaining the test and surface ornamentation,
enlarged to two diameters.

Hamilton group. Tork, N. ¥.

I'l.ATK l.X\ 111— Continued.

CONOOARDIIIM DEXTICULATIJM.

rage 413.

Figs. 24, 25. Left side iind ventral views of an imperfect specimen, onlai'ged lo three diameters. Fig'. 25

repi-ei*ents the dentieulations of the margins as too slender, and interlocliing more than in the

specimen.

Hamilton group. York, N. Y.

CONOCAKUIL'JI CONOINNUM.
r:iKe 414.
V\g. 2C. Posterior view of a specimen.

Hamilton group. P^ratVs falls, N. Y.
Pig. 27. Ventral view <rf another individual.

CONOCAKDIUM LIKATUM.
Page 414.
Fig. 28. A rig-ht valve as obtained from a gutta-pei-cha impression of a natural mould, enlarged to three
diameters.

Lower Chemung group. lOiaai. JS. Y.
Fig. 29. Anterior view of a specimen enlarged to thi-ce diameters.

Lower Chemung gfroup. Jthaca, Xf- Y. .

' ' ' K IKI;

CONOCARDIOM TEGULUM.
Page 415.
Fig. 30. A fragment of an individual of this species.
Fig. 31. An enlargement of the surface of the preceding.
Niagara group.

CONOCARDIUM INCEPTUM.
I'age 415.
Fig. 32. Ventral view of a specimen, enlarged to two diameters.
Lower Helderbei-g group. Albany Co., N. Y.

CONOCARDIUM RELIQUUM.
Page 41S.
Fig. 33. A view of the posterior end of a specimen as obtained from a gutta-percha impression.
Chemung group.

{CARDIin.ffi .)

Palaeontology NY.Vol Y

Plate Lxym.

UK .,,.,.,, dd

PLATE LXIX.

PaNENKA VENTK1008A.

Page 417.
Fig. 1. The left valve of a specimen. The beak is represented as too obtuse in the figure.
Fig. 2. Cai-dinal view of the preceding, showing the ti-iaiigular area under the beak.
Gouiatite limestone. Sc/uiJiarie, N. Y.

Panenka Hero.

Pugc 418.
Fig. 3) A left valve. The beak is not sufficiently elevated in the figure.
Marcellus shale. Indian resercation, Brie Co., N. Y.

Panenka equilatera.

I'.ige 419.

See Plate 94.
Fig. 4. A right valve.

Marcellus shale. TAWfrille, N. Y.
Fig. 7. Cardinal view of a left valve, doubtfully referred to this species.

Hamilton group. Cumberland, Md.

Panenka multiradiata.

Page 417.
See Plate 94.
Fig. 5. The right side of the specimen described. See fig. 18, plate 94, for a correct drawing of the same.
Comiferous limestone. Clarence Hollow, Erie Co., N. Y.

Panenka retusa.

Page 421.
Pig. 0. Left valve. The radii are represented as too close together.
Hamilton group. Shore of Cayuga lake, N. Y.

ejjATK l.XIX-Uontiuued.

"PaNKXKA POTEN8. '

I'aifO 4Si.

Fig. 8. Right side of n specimon showing: the form and surface charsiRte™.

Haniilton group. Mailinon Co., N. ¥.

Kig. 10. Tho loft side of a s]iecimeii retaining- both valves in conjunction. The right valve is erroneously

represented a-s having a l)roa(l ligamental area.

Hamilton group. ilad-Uum Coi, N. Y.

I

Pajjenka radians.

Page <M.
Fig. 9. Left side of a sjiecimen i-etaining both valves.
Hamilton group. Cazeimria, N. 1'.

Panenka abkupta.

Piigc 423.
See Plate 94.
Fig. 11. Cardinal view of a cast of the intei-ior.

Hamilton group. Cmtiherland, Md.

Panenka Linokl*ni.

Page 420.
Fig. 12. A right valve of ordinary size.

Marcellus shale. Ontario Co., N. Y.
Fig. 13. A somewhat largei' I'ight valve of this species.

Marcellus shale. Musion House, four miles south of Buffalo, N. Y.
Fig. 14. An unusually large left valve.

Marcellus shale. Mission House, four miles south of Jitiffalo, N. Y.

Palaeontology NY.VolV

( cAHniin.E.)

Plate LXE.

JHEroertoti M

Riemaim,litli

PLATE LXX.

Cardiola fluctuans, Bavr.

¥ig. 1. Cardinal view of the right valve, showing the triangular area under the beak. This species is
introduced for comparison with American allied forms. See plate 94, fig. 23.
Silurian. Bohemia.

Gl..YPTOCARniA SPECIOSA.
Page 426.
See Plate 80.
Figs. 2, 3. Views of two specimens retaining both valves in conjunction, enlarged to four diameters.

Genesee slat«. Bristol Centre, N. ¥.
Fig. 4. A right valve enlarged to four diametere.

Genesee slate. Ontario (k>., N. Y.
Fig. 5. An eidargement of a small left valve.
Figs. 6-8. Three valves showing strong surface ornaments.

Portage gi-oup. Brawliport, N. Y.
Fig. 9. A right valve enlarge<l to three diametei's, .showing .strong arching lamellose striae on the radii.
Marcellus shale. Skaneateles, N. Y.

Paracakdium Dori.s.

Page 428.
Figs. 10, 11. Two valves of this species enlarged to six diameters.
Portage group. Cashaqua creek, N. Y.

Pabarca transversa.

Page 429.
Fig. 12. A lefl valve.

Chemung group. Salamanca, N. Y.
Figs. 14, 15. Two right valves.

Chemung group. SaJamaniu, iV. F. MB

Par ARC A NEGLEOTA.
Page 432.
Fig. 13. A left valve showing the form &nd surface characters.
Waverly group. Meadmlle, Pa.

PLATE LXX— Continued.

Pararca ERECTA.
Page 432.
See Plate 94.
Fig. 16. A left valve.

Waverly group. Meadville, Pa.

Pararca Sao.

Page 430.
Fig. 17. A right valve. The umbonal slope is more defined than repi-esented in the Bgure.
Chemung gi"oup. Meadville, Pa.

Pr.s:cardium venostum.

Page 427.
Figs. 18-20. Thi-ee valves showing the prevailing chai'acters of the species.

Portage group. Shore of LaJce Erie, Cliautauqtui Co., N. ¥.

Panenka dichotoma.

Page 416.
See Plate 94.

Fig. 21. A large right valve.

Schoharie grit. Schoharie, N. Y.

Panenka robusta.

Page 424.
Figs. 2^-24. Two left valves and one right valve of this species, showing the characteristic form and surface
ornamentation.

Portage group. Below Portage, N. Y.

Cardiopsis eadiata.

J'age 433.
Pig. 2.'). A right valve of this species.

Kinderhook group. Jtocltford, Iowa.

Palaeontology NY Vol V

(CARDIID^.)

Plate LXX.

, H £fn«u>n dd

Rjenr':i:uui

PLATE LXXI.

LUNULICARDIUM FRAGILE.
Page 434.

Figs. 1-8. A series of valves representing the prevailing chai-acters of this species, enlarged to two diameters.
Fig. 9. A specimen retaining both valves in conjunction, enlarged to four diameters.

Genesee slate. Bristol Centre, JV. Y.
Fig. 10. A small right valve, enlarged to four diameters.
Fig. 11. A specimen i-etaining both valves.

Genesee slate. Bristol Centre, N. Y.
Fig. 12. A left valve showing the expansion of the sheil along the posterior margin, enlarged to two diameters.

Genesee slate. Indian reservation, Erie Co., N. Y.
Fig. 13. A large left valve, enlarged to two diametei-s.

Genesee slate. Penn Yan, Yates Co., N. Y.
Fig. 14. The interior of two valves, eulai-ged to four diameters.

Genesee slate. Penn Yan, N. Y.

LuNULIOAKmUM Mauoellknse.

Pago 435.
Figs. 15, 16. Two left valves retaining portions of the test.
Marcellus shale. Cherry Valley, N. Y.

LUNULICARDIUM RUDE.
Page 435.
Fig. 17. A right valve, showing the foi-m and surface charactei-s.
Goniatite limestone. Cherry Valley, N. Y.

I'LATE LXXI— Cc.llUllucil.

LUNULICAHOIUM CUUTUM.
I Pago 4S7.

Pijf. 18. A left valve of this species.

Hamilton jfi-oup. Near Tully, N. F. •
Fig. 19. An enlarjfenient of the pi-ece<ling to .show nioi-e clearly its characteristic features.
Fig. 20. A right valve of somewhat ilitfei-eiit form.
Fig. 21. An enlargement of the same.

Hamilton group. Shore of Cay uya kih, y. Y.
Fig. 22. A right valve of a stnnewhat broader form.

Mai-cellus shale. AUUn, Erie Co., N. T.
Fig. 23. An enlargement of the surface from the lower margin of the specimen fig. 18, showing its
pustulose character.

LUNULICAEDIUM ORBICULARE.

Pago &a.
Fig. 24. A left valve.

Marcellus shale. Bloomfield, N. Y.

LUNULICARDIUM ORNATUM.
Page 437.
Pig8. 25-27. Three valves showing the characteristic foifn of this species. The beak of fig. 26 is repre-
sented as too obtuse.

Chemung group. Elmira, N. Y.
Fig. 28. A left valve. The radii are more flattened than represented in the figui-e.

Portage g^i-oup. Cashaqiui creek, N. Y.
Fig. 29. An enlargement of the surface from the preceding.

Fig. 30. A left valve, laterally compressed, producing an elongate form. The specimen is the original of
Pinnopiis acutinostra.

Portage group. Casha/iva creek, N. Y.
Fig. 31. A right valve similar to the preceding.

Chemung group. Near Elmira, N. Y.
Pig. 32. An enlargement from the surface of the specimen fig. 30. The summits of the rays are repre-
sented aa too concave.

Palaeontology NYVolV

' ( fAFIIIIl).)^.)

Plate L5

^i| ^j^

8 13 9 10

12

J li BmCTlon Id

4bl

PLATE LXXII.

Paracyclas Ohioensis.

P)i^ 442.

See Plate 95.
Fig. 1. The right side of a specimen retaining' the test.

Hamilton group. Falls of the Ohio river.

PaRACTCLAS lilRATA.

Page 441
See Plate 95.
Figs. 2-5. A Herie.s of specimens illustrating the principal varieties of form and surface markings charac-
teristic of the species, as found in the Cherty beds, above the Corniferous limestone belonging
to the Hamilton group, at the falls of the Ohio river and in Clarke Co., Ind.
Figs. 6-19. A series illustrating the i)rincipal varieties as found in th(! Hamilton group in the State of New
York. Figs. 9, 10 and 13 illustrate specimens distorted by pi-essure.

Paracyclas tenuis.

Page 443.
See Plate 95. j

Figs. 20, 21. Two right valves enlarge<l to three diameters. J

Hamilton group. Belhma and shore of Cayuga lake, N. ¥. '

Fig. 22. A large left valve enlarged to three diameters.

Hamilton gi-oup. Shore of Skaneatelet lake, N. Y.

T/? -.^nwoils te

I'LATK IJCXII— Continued.

PAKACrCLAS ELLIPTICA.
Page 440.
See Plate 95.
Fig'. 23. The left side of a specimen.

Comifei-ous limestone. Clcuretux, N. T.
Rg. 34. The right side of a cast.

Comiferous limestone. Columbus, OJiio.
Figs. 26, 26. Left side and cardinal views of a specimen which is vertically compressed.

Comiferous limestone. Leroy, N. Y.
Figs. 27, 28. The right side and cai-dinal view of the cast of the interior, showing muscular scars, pallial
line and ligamental grooves.

Comiferous limestone. Cayuga, Ontario.
Fig. 29. The left side of a lai-ge specimen.

Comiferous limestone. Western New York.
Fig. 30. The right side of a specimen, narrowed by compi-ession.

Comiferous limestone. Leroy, N. Y.
Figs. 31-33. Left, right and cardinal views of an individual, retaining the shell and showing the surface
characters.

Hamilton group. Fhlls of the Ohio river.

Paracyclas ignota.

Pago 444.
Fig. 34. A right valve of this species.

Chemung gi-oup. Meadville, Pa.

SOHIZODUS ? ri88A.
Page 447.
Figs. 35, 36. The right side and cardinal views of a cast of the interior.

Schoharie grit. iSc/ioharie, N. Y.
Fig. 37. The right side of a compressed specimen.

Schoharie grit. Schoharie, N. Y.
Rgs. 88-40. Right, left and cardinal views of a cast of the interior, showing muscular impressions.

Schoharie grit. Schoharie, N. Y.
Fig. 41. The right side of a cast showing anterior and posterior muscular scars.

Schoharie grit. Schoharie, N. Y.

Palaeontology NY.VolV

Plate LXXII

r

9'lliJ

^1

-'^5r-**

PLATE LXXIII.
MicRODON (Cypricaruklla) oreoabius.

Pago 309.
See Plate 74.
Figs. 1-6. Three right and thi-ee left valves showing the principal varieties of form and size.

MiCRODON (Cypkicardella) BELLISTRIATUS.

Page 3>;s.
See Plates 4:.', 74.
Figs. 7-20. A series of specimens illustrating' the principal varieties of form and surface characters.
Figs. 21, 22. The left and right sides of a specimen retaining both valves, showing the narrow form of the
right valve, as produced by vertical compression.
Hamilton grroup. N. Y.

MiCRODON (CvPRICARDELLA) TENUI8TRIATUS.

I'ago 310.
See Plates 42, 74.
Figs. 23, 24. Two right valves.

Hamilton group. Madison Co., N. Y.
Fig. 25. A partial cast of a left valve, showing the anterior muscular scar and surface markings.

Hamilton group. MctdUon Co., N. Y.
Fig. 26. A specimen retaining both valves in conjunction.

Hamilton group. /Summit, Sclioliarie Co., N. Y.
Figs. 27, 28. Right and left valves of elongate form.

Hamilton group. Shore of Canandaigua lake, N. Y.
Fig. 29. A left valve.

Hamilton group. Madlion Co., N. Y.
Fig. 30. The interior of a left valve, as obtained from a gutta-pei-cha impression, showing the hinge area,
anterior muscular scar and pallial line.

Hamilton group. Madison Co., N. Y.

mLAm.:imrmm ©mmwiF.

Palaeontology NYVolV.

( ASTARTID/E )

Plate IiXXm.

'-.n4-r. .x. d«l

sTaK-T,

Vb

■'UMh^

PLATE LXXIV.

MiCRODON (Cil'UlCAKDKI.l.A) UKEOAUIUS.
Page 309.
See Plate 73.
Figs. 1, 2. Right and left valves.

Chemung group. Cortiand, N. Y.
Fig. 3. A left valve of more elongate form.

Fig. 4. A small left valve enlarged to two diameters. The striie are represented as too regular and tliu
beak too elevated.

Chemung gi-oup. Near Elmira, N. ¥.

MiCRODON (Cypricardella) bellistriatus.

Pago 308.
See Plates 42, 73.
Figs. B, 6. Two right valves of elongate form.

Chemung group. Near Elmira, N. T.
Figs. 7, 8. Right and left valves.

Lower Chemung group. Ithaca, N. Y.
Fig. 9. The hinge of a left valve showing cai'dinal teeth and ligamental area, enlarged.

Hamilton group. Slu>re of Skaiieatdes lake, N. Y.
Fig. 10. The hinge of a right valve, showing similar characters, enlarged.

MiCRODON (CyPRICARDELLA) RE8ERVATCS.
Piigc 313.
Figs. 11-13. Three valves showing the principal characters of this species.
Waverly group. Licking Co., Ohio.

MiCRODON (CyPRICARDELLA) COMPLANATU8.
Page 3U.
See Plate 42.
Figs. 14-18. A series of valves showing the piincipal variations in size and form of this species.

Hamilton gi-ouj). Schoharie Co., N. Y.
Fig. 19. The interior of a right valve, as obtained from a gutta-percha impression in a natural mould,
showing hinge characters, anterior muscular scars and pallial line.

MiCRODON (Cypricardella) TENUISTRIATUS. %

Page 310.
See Plates 42, 73.
Figs. 21, 22. The hinges of a left and a right valve showing cardinal teeth and ligamental area, enlarged to
two diameters.

Palaeontology NYVolV

( ASTARTIDyE. )

Plate L2

OBR ifl

PLATE LXXV.

SCHIZODUS TUMIUUS.

Page US.
Figs. 1, 2. The right side and cardinal view of a cast of the interior, showing muscular scars and pallial line.
Comiferous limestone. Columbus, Ohio.

SCHIZODUS APPRESSUS.
Page 449.
Fig. 3. A cast of an interior of a right valve, showing umbonal fun-ows, muscular scai-s and pallial line.

Hamilton group. Pratt's falls, Onondaga Co., N. Y.
Fig. 4. A left valve of ordinary foi-m.

Fig. 5. A specimen preserving both valves conjoined by the ligament.
Fig. 6. A left valve which is somewhat iiasute at post-inferior extremity.

Hamilton group. Shore of Cayuga lake, N. Y.
Fig. 7. A right valve of elongate form.

Hamilton group. Shore of Cayuga lake, N. Y.
Fig. 8. A small right valve of rotund form.

Hamilton group. Schoharie Co., N. Y.
Fig. 9. A larger right valve.

CyTHEROTX)N NASUTUS.
Page 511.
See Plate 95.
Fig. 10. The left siile of the specimen described. See plate 95 for a coi'rect drawing of this specimen.

Hamilton group. Hardy Co., Va.
Fig. 11. Cardinal view of the preceding, showing the inipi-cssions of the cardinal teeth.
Pig. 12. The interior of the canlinal portion of the same, as obtained from a gutta-pei-cha impression.

SCHIZODUS ELLIPTIOUS.

Page 450.
Fig. 13. A right valve.

Hamilton group. Shore of Canandaigua lake, N. Y.

Yigs. 14, 15. Two small left valves.

Hamilton group. Shore of CaiuiTulnigna lake, N. Y.

'^^KSiu..

SCHIZODUS GKEGARIUS.
Page 452.

See Plate 95.
Pig. 16. A left valve of this species.

Chemung group. Near T%oga, Pa.
Pig. 17. A portion of a block preserving the remains of several individuals.

Chemung group. Near Tioga, Pa.
Fig. 18. A right valve.

Chemung group. Near Tioga, Pa.

SCHIZODUS RHOMBBUS.

Page 452.
Fig. 19. A left valve.

Chemung gi-oup. Hobbieoille, N. Y.
Pig. 20. A left valve of somewhat different foi-m.

Chemung group. Chautauqua Co., N. Y. 'HtSl^k

Figs. 21-23. A left valve and two right valves of this species. '^^^

Chemung group. Cattaraugus Co., N. Y.

PLATE LXXV— Contlnuml.

PaKACVCLAS ? I'AUPEU.

ruga M&

See Plate 95.

Fig. 24. A right valve, imperfectly i-epi-esented.

Cheniunj,' fe'i-oiip. Alleghany Co., N. T.
Fig. 25. A Kinall left valve. See fig. 20, plate 95, for a cori-ected drawing of this specimen.
Fig. 26. A large right valve.

Chemung gi-oup. Ntxir Olean, N. F.

SCHIZOnUS CONTRACTUS.

Page 451.
Figs. 27, 28. Two right valves enlarged to two diameters, showing the foim and surface markings.
Hamilton group. Shore of Cayuga lake, N. Y.

SCHIZODUS CUNEUS.
Page 438.
Fig. 29. A right valve of this species.

Waverly group. Qraninlk, Ohio.
Fig. 30. A right valve referi-ed to this species with doubt.
Waverly group. Orunville, Ohio.

fcjcuizoDus Chemungensis, var. (Juadranoulakis.

Page 4M. »

Fig. 31. A cast of the interior of a small left valve, showing muscular scars and pallial line.

Lower Chemung s'"0"P- Ithaca, N. Y.
Fig. 32. A partial cast of a larger right \ alve.
Fig. 33. A left valve of erect form.

Chemung group. Near Elviira, N. Y.

Fig. 34. A large right valve.

Chemung group. Tioga Co., N. Y.
Pig. 36. A left valve of medium size.

Chemung group. Factoryville, Tioga Co., iV. Y.

ScuizoDus >:qualis.

Page 469.
See Plate 95.
Fig. 35. The left side of an imperfect specimen preserving both valves.
Waverly gi-oup. Licking Co., Ohio.

ScHizoDUS Chemongensis.

Page 453.
Figs. 37-40. Two right and two left valves belonging to this species.
Fig. 41. An imi)erfect left valve referred to this species with doubt.
Fig. 46. A small left valve.

Chemung group. Cortland, N. Y.

Edmondia rhomboidea.
Page tSB.

See Plates 64, 95.
Fig. 42. A left valve. See plate 96, fig. 15, for a corrected drawing of this specimen.

SCHIZODUS OBLATU8.
Page 456.
Fig. 43. A left valve.

Chemung group. Napoli, Cattaraugus Co., iV. Y.
Fig. 44. The cast of interior of a right valve showing muscular scars.
Chemung group. Napoli, Cattaraugus Co., N. Y.

Palaeontology NY.VolV.

( CTTUIJtODOXTID^; .)

Plate LXW.

I'

PLATE LXXVI.

Pkothykis planulata.

Page teo.
See Plate 94.
Vig. 1. The left side of a specimen enlarged to two diametei's.

Hamilton group. Outlet of Crooked lake, N. Y.

Prothykis lanceolata.

Page 460.
KgB. 2-8. A series of specimens showing the prevailing forms in this species. Fig. 8 is enlarged to two
diametei's.

Hamilton group. Eastern and central New York.

MODIELLA PYGM^A.
Page 614.
Figs. 9-20. A series of valves illustrating the principal varieties of form and surface characters of this
species. Figures enlai-ged to two diametei-a.
Hamilton g^roup. Central New York.

Tellinopsis subemaeginata.

Page 464.
Figs. 21-31. A series of valves showing variations in size and form.
Hamilton group. Eastern and central New York.

Palaeontology NY Vol V

( FAMILIES rXDET )

Plate LXXVI.

RiemanrvLGi.

m

PLATE LXXVII.

ClMITARIA CORRUGATA.
Page 46S.
Kg. 1. The right side of an imperfect specimen showing plications on the post-cardinal slope.

Hamilton group. Monteith's point, CanandaigiiM lake, N. Y.
Fig. 2. The right side of a lai'ge individual.

Hamilton group. iSliore of Canandaigua lake, N. Y.
Fig. 3. A small left valve.

Hamilton group. Sherburne creek, N. Y.
Fig. 4. The right valve of a young individual, showing strong folds on the post-cardinal slope limiting the
umbonal angle.

CiMITARTA ELONGATA.

Pago 4«6
Kgs. 6, 6. Two left valves showing the prevailing form of this species.

Hamilton group. Schoharie and Onondaga Co's, N. Y.
Fig. 7. A large right valve.

Hamilton group. Pra'fs falls, Onondaga Co., N. Y.
Fig. 8. A cardinal view of a specimen retaining both valves.

ClMITARIA RECURVA.
Page 467.
Fig. 9. The right valve of a small individual.

Hamilton group. Delphi, iV. Y.
Fig. 10. The right valve of a large individual.

Hamilton group. Madison Co., N. Y.
Fig. 11. The cardinal view of a compressed specimen retaining both valves.
Fig. 12. The right side of the preceding.

Fig. 13. The right side of a specimen preserving the surface ornamentation.
Fig. 14. A left valve of falcate form.

Hamilton group. Madison Co., N. Y.
Fig. 16. An enlargement of the sui-face from specimen fig. 13.

ClMITARIA ANGULATA.

Page 468.
Fig. 16. A left valve of a specimen which is somewhat compressed vertically and folded along the umbonal
angle. Chemung group. Between Elmira and Waverly, Tioga Co., N. Y.

Palaeontology NY.VolV

( PHOI,ADELLIU,«: . )

Plate LXXVn.

t

J y. Emsncn Iri

PLATE LXXVIII.

PhIHOMA CYLINDEICA.
Page 473.
Figs. 1, 2. Two rig-ht valves showing the ordinary form of this species.

Hamilton group. Pompey Hill and share of Cayuga lake, Onondaga Co., N. T.
Figs. 3, 4. Two left valves of somewhat ditleront proportions from the preceding specimens.
Hamilton grouj). Oiwndaga Co., M. ¥.

Phthonia nodicostata.

Page 474.
Fig. 5. A small right valve.

Hamilton group. SJtore of Catiandaigua lake, iV. Y.
Fig. 6. A larger right valve.

Hamilton group. Near Oneonta, N. Y.
Figs. 7, 8. Two left valves showing the surface ornamentation characteristic of this species.

Hamilton group. Shores of Canandaigua and Cayuga lakes, N. Y.
Fig. 9. An enlargement of a portion of the surface from the specimen fig. 7, showing the nodose chai'acter
of the ra<iii.

Phthonia sectifkons.

Page 475.
Fig. 10. A small left valve.

Fig. 11. A large left valve narrowed by compression.

Fig. 12. A large right valve showing the fonu and surface characters.

Hamilton group. Cazeyunria, N. Y.

Fig. 13. A specimen retuning both valves in conjunction. .^^i^^

Phthonia likata.

Page 476.
Fig. 14. The right valve of the specimen described, as obtained from a gutta-pereha impression, enlarged
to three diameters.

Hamilton group. Slwre of Cayuga lake, Hf. Y.

Pholadella radiata.

Page 469.
See Plate 96.
Figs. lR-18. Two right and two left valves showing the prevailing forms of this species.
Fig. 10. Cai-iliiial view of a compn!s.sed s]>ccimen i-etaining both valves.

Hamilton group. Cazenoma, N. Y.
Fig. 20. A right valve of unusually large size.

Hamilton group. Fahius, N. Y.
Fig. 21. An elongate right valve.

Lower Chemung group. Ithaca, N. Y.

Pholadella pakallei,a.

Page 470.
Figs. 22, 23. Right and left valves.

Hamilton gi-oup. Shore of iStkaneateles lake, N. Y.
Fig. 24. A portion of a block preserving the remains of numerous individuals of this species.

Hamilton group. Near Fafnus, N. Y.

PLATE l.XXVIll— Contlnuo.l.

Pholadklla Newbkkryi.

I'nge 471.
Kijr- -5. A loft valve shuwiiijr tin? fni-iii niul 8Ui-fa<re markiiijff . Tho posterior extremity is i-estoi-ed in the
tig'ure. Wnverly gTOiip. Licking Co., 0/iio.

Grammysia constkicta.

Page 377.
See Plate SO.

FigB. 26, 27. Two right valves enlarged to two diauietei-s showing the form and surface characters.
Kig. 26, Hamilton group. Otsego bo'., if. T. '

, PROMACRU8 CUNEATU8.
Page 510.
Fig. 38. The anterior portion of an imperfect right \ alve.

Burlington Bandstone. Barlingtoti, Jotoa.

ORTHONOTA ? PARVULA.
Page 48-2.
See Plate 65.
Figs. 29-32. Four specimens retaining both valves in conjunction, showing some variation in size and pro-
portion. Figs. 29, 30 and 31, enlarged to two diametei's.
Hamilton group. N. Y.

SOLEN (PaL.«;OSOLEN) SILIQUOIDEA.

Page 183.
Fig. 33. The right valve described.

Hamilton group. Schoharie Co., N. T.

Orthonota oarinata.

Page 479.
Fig. 34. A specimen retaining both valves conjoine<l along the hinge, enlarged to two diameters.

Hamilton group. IShore of Cayaga lake, N. T.
Fig. 35. A right valve, natural size. The posterior extremity is incorrectly restored in outline.

.'. 1 t.'.iti.;i /.i.ir<(i/..i(i!

Orthonota ensiformis.

Page 480.
Fig. 36. A view of the right valve described as obtained from a gutta-pereha impression of the natui-al
mould. Hamilton group. Sclioliarie Co., N. Y.

Orthonota undulata.

Page 478.
Fig. 37. A young in<lividual reigning both valves.

Hamilton gi-oup. Bear's gulf, Seholuiru'. Co., N. Y.
Fig. 38. A specimen of medium size preserving both valves, conjoined at the hinge-line.

Hamilton group. Beat'* gulf, Schoharie Co., N. Y.
KgH. 39, 40. Left and right valves showing the forai and surface characters.

Hamilton group. Schoharie Co , K. Y.
Fig. 41. The right side of a large specimen.

Hamilt<m group. Bear's gulf, Schoharie Co., N. Y.
Vig. 43. The right side of a somewhat smaller individual.

Hamilton g^np. Fhtltonham, Schoharie Co., N. Y.

SMysairairmii? dk -w^ssymM,^ ©oaoimps ,

Palaeontology NY Vol V

( PHOLADELLID.C . )
( OBTHONOTID>« etc.)

Plate, ixxvnr.-

I

t J H tmcrt',r 1»1

PLATE LXXIX.
Cypricardinia planulata.

Page 484.
Figs. 1, 2. A right and a left valve of this species.

Schoharie grit. Scholiarie, N. Y.
Fig. 3. A cast of a right valve showing muscular scars and pallial line.

Schoharie giit. Schoharie, JV. Y.
Figs. 4, 5. Cardinal view and left side of a spooimen showing the inecpiality of the valves and muscular scai-s.

Schoharie grit. Schoharie, N. Y.

i

Cypbicakdinia indenta.

Page 485.
See Plate 96.
Figs. 6-8. Right and left valves showing the usual form of the species, enlarged to two diameters.

Comiferous limestone. Balcock's hill, Oneida Co., iV. Y.
Fig. 9. An elongate right valve, enlargeil to two diameters.
Fig. 10. A right valve, enlarged to three diameters.
Fig. 11. A left valve.
Fig. 12. A right valve, natural size.
Fig. 13. A small left valve, enlarged to three diameters.
Fig. 14. A right valve, enlarged to three diameters, showing the surface markings.

Hamilton group. Ontario Co., N. Y.
Fig. 15. An elongate left valve, enlarged to two diametei-s.

Hamilton group. Shore of Canandaigua lake.
Fig. 16. A left valve, similar to the preceding, natural size.

Hamilton group. Shore of Ovmuco lake, N. Y.
Fig. 23. A right valve preserring the test and sui-face markings.

Hamilton group. Moscow, N. Y.

. iGrPKIOAHUINlA AI^qUATA.
Page 486.
Fig. 17. A left valve of this species, enlarged to two diameters.
Chemung group. Near Elmira, N. Y.

PLATK LXXIX— Continucil.

CYPKICARniNIA CONSIMILI8.
Page ««.
See Plate 96.
Fig. 18. A right valve presei-ving a i>ortion of the test with the surface markings and showing the posterior
muscular scar, enlarged to two dianieters. Referred to this species with doubt.
Waverly group. HkhJUld, Summit Co., Ohio.
Pigs. 19-21. Left, right an<l cai-dinal views of a cast of the interior.
Waverly group. ZActnng Co., Ohio.

Cypkicakdinia sulciferus.

Pago 487.
Fig. 23. A partial cast of the interior of a right valve, enlarged to three diameters.
Yellow sandstone. Burlington, Imoa.

CyPRICARDINIA ? CYLINDRICA.
Page 486.
Figs. 24, 25. Left side and cardinal views of the original specimen.
Hamilton group. Near Louisville, Ky.

PAL.SANATINA TYPA.
Page 188.
Figs. 26, 27. Two left valves of the ordinary form.

Chemung gi-oup. Portville, N. T.
Figs. 28, 35. Two right valves, showing their deju-essed form.

Chemung group. Portville, N. T.
Figs. 36, 37. Two left valves with the cincture less developed than in figs. 26 and 27.
Chemung group. Portville, N. T.

Pal^anatina ANGUSTA.

Page 4»0.
Figs. 29, 30. Two right valves.

Chemung group. Near Portville, N. T.
Figs. 31-34. Four left valves showing some variations in form and proporUons.

Chemung group. Near Portville, N. T. '^'- •^"'"» "^'^«""

PaL^ANATINA SOLENOIDE8.

Page 489.
Figs 38 39 Left and right side of a specimen retaining both valves, showing the form and surface
characters. . i ,^. .,v,,«:,-V,u«/v .-i.;...,, ^w.msdU

Chemung group. Near PortvUle, N. T.

Prorhynchus quadratum.

Page 492.
See Plate 96.
Ftga. 40-49. A series of valves showing considerable variation in size and form.
Chemung group. Near Smelhport, Pa.

Palaeontology NY.VolV

( FAMILY? & PAI.AXATINID^.)

PlateLX

I

bf,'

PLATE LXXX.
Mytilarca pyramidata.

I'agc i86.
Figs. 1, 2. Left side and anterior view of a cast of the interior.

S<-hohaine grit. Schoharie, N. Y.
V\g. 3. The right side of a spe<'inien, somewhat smaller than the preceding.

Schoharie grit. Schoharie, iV. Y.

Leitodesma ?

Pig. 4. An olieuure right valve of undetermined relations.
Chemung group. Salaiiumca, N. Y.

SpHENOTUS (?) UNDATUS.

PageSOe.
Fig. 5. View of a left valve as obtaine<l fi-om a gutta-percha impression in a natural mould.
Chemung gi-oup. Mansfield, Pa.

ORTnONOTA RIGIDA.

Page 481.
Pig. 6. A right valve showing the form and surface markings.
Chemung group. Near Ehnira, N. Y.

MomOMORPHA ALTA.

I'ngi! 278.
See Plate 37.
Fig. 7. The right side of a distorted specimen.

Hamilton group. Pratt's falls, N. Y.

Panenka mollis.

Page 420.
Fig. 8. A specimen preserving both valves in conjunction, showing the form and surface characters.

Mareellus shale.
Fig. 9. Cardinal view of a small specimen retaining both valves in conjunction. Doubtfully referred to
this .species.

GlYPTOCARDIA 8PECI08A.

Pago 426.

See Plate 70.

Pig. 10. View of a specimen retaining both valves, showing strongly developed surface ornaments,

enlarged to four diametere.

Byssopteria radiata.

Page 25-2.

See Plate 32.
Fig. 11. A large right valve.

Chemung group. Mantfi^ld, Pa.

Amnigenl^ Catskillensis.

Pago 616.
See Plate 40.
Rg. 12. The right valve of a very large individual.

Oneonta sandstone. Pennsylvania.

wiFipaiii amLmiuMjisa© irm 'SMS'^miiLm m3i®mp^

Palaeontology NYVolV.

Plate IE

Riema-nn,iul^

PLATE XCIlI-Contlnaed.

Grammysia UNDATA.

V&ge 379. ••

See Plates 61, (i4.
Fijf. 21. A U'fl valve.

Chemnng group. Near Olean, Al T.

Gkammysia ovata.

Page 358.
Fig. 22. A specimen retaining both valves in conjunction.
Corniferous limestone. Delavxire, Ohio.

Grammysia duplicata.

Pago 380.
Fig. 23. A right valve showing surface ornamentations.

Chemung group. U'arre?!, Pa.
Fig. 23a. A profile of the preceding.

Grammysia glabra.

Pig. 24. A partial cast of a left valve showing the muscular scars and lines of gi-owth.
Chemung group. Warren, Pa,

Grammysia bisdlcata.

I'age :J59.
See Plates 54, 56.
Pig. 25. A right valve showing strong concentric umlulations of the surface and fine radiating stne.
Hamilton group. Albany Co., N. Y.

Grammysia subarcuata.

Page 373.
See Plate 61.
Fig. 26. Anterior view of a specimen showing a very strongly developed lunule.
Chemung group.

Grammysia arcuata.

Page S73.
See Plates 61, 63.
Fig. 27. The left side of a specimen showing concentric undulations.
Hamilton group. Pratt's falls, N. T.

EUTHYDESMA SUBTEXTILE.
Page 38.^.
See Plate 63.
Pig. 28. The hinge of a left valve showing the straight ligamental area.
Pig. 29. An enlargement of the surface from another specimen.

Portage g^-oup. Near Portland Harlxir, Chatitaitqua Co., iV. T.

irJ-^3^Sli 3EEa.I]lI3n3ER© irOD ■\!T^SyMI3:L'2' 'BlEliQ-iJiP.

Palaontology of N.T.Tol.YPt.I.

Plateicm.

T-'h.A.-.-t lr.il.

PLATE XCIV-ConUnued.

Panenka ABRUPTA.
Page 423.
See Plate 69.
Fig. 16. The left side of a specimen with the valves slightly displaced.
Hamilton group. Near Cumberland, Md.

Panenka equilatera.

Pago 4J9.
See Plate 69.
Fig. 17. The left side of a specimen showing the form and surface markings.
Hamilton group. DdpM, N. Y.

Panenka multiraoiata.

Page 417.
See Plate 69.
Fig. 18. The right side of the specimea described.

Comiferous limestone. Clarence BoUow, Erie Co., N. Y.

Pararca PR^CEDENS.

Page 429.
Fig. 19. An imperfect left valve as obtained fi-om a gutta-percha impre&sion of a natural mould.
Comiferous limestone. Cayuga, CaiMda West.

Pararca ereota.

Page 432.
See Plate 70.
Pig. 20. A left valve showing the foi-m and surface markings. A profile of this valve is represented at the
right of the figure.

Waverly group. Warren, Pa.
Fig. 21. The hinge of a right valve showing the minute crenulations.
Waverly group. Warren, Pa.

Pararca venusta.

Page 4.11.
Kg. 22. A right valve.

Chemxmg group. Warren, Pa.

Cardiola FLU0TDAN8, Banaiide.
See Plate 70.
Fig. 23. A right valve showing the fonn and surface ornamentations. Introduced for comparison with the
species of Panbnka, Pararca and allied forms.
Silurian. Bohemia.

LUNULIOARDIUM TRANSVERSUM.
Page 439.
Fig. 24. Cardinal view of the specimen described, showing the hiatus along the cai-dinal line.

Chemung group. Elmira, N. Y.
Pig. 25. The left side of the preceding.

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Plate XCr/.

Ph.JisT Iltit.

PLATE XCV.
Edmondia Philipi.

Pago 387.
See Plate G4.
Figs. 1-4. A series of valves showing the prevailing characters of this species.
Chemung group. AUegliany Co., N. Y.

P^DMONDIA OBLIQUA.

Page 388.
See Plate 64.
Fig. 5. A left valve.

Chemung group. Man.ifield, Pa.
Fig. 6. A larger left valve showing obscure radiating lines.

Chemung group. Hobl>ieville, N. Y.
Fig. 7. A right valve of this species.

Chemung group. Jiockville, N. T.
Fig. 8. A specimen preserving both valves in conjunction.

Chemung group. Mansfield, Pa.

Edmondia scbovata.

Page .S89.
See Plate 64.
Fig. S». A well-preserved ajiecimen showing both valves in conjunction.

Chemung gi'oup. Mansfield, Pa.
Fig. 10. A small right valve.

Chemung group. PhiUpulmrgli, Alleghany Co., N. Y.

Fig. 11. A left valve.

Chemung group. Ilobbieville, Alleghany Co., N. Y.
Fig. 12. A large right valve.

Chemung group. ManxJUld, Pa.

Edmondia Buulingtonensis.

Page 390.
See Plate 64.
FigB. 13, 14. Two valves showing the usual characters of this species.
Yellow sandstone. Burlington, Iowa.

PLATE XCV— Continued.

Edmondia RHOMBOIDEA.
Page 388.
See Plates 64, 75.
Fig. 15. A left valve showing the anterior muscular scar.
Fig. 16. A smaller and more convex j-ight valve.

Chemung group. JVear Panama, JV. T.

EdMONDIA ? TENUrSTRIATA.
Page 393.
See Plat* 63.
Fig. 17. A left valve showing the form and surface characters.
Chemung gi-oup. Elmira, N. Y.

Pakacyclas elliptica

Page 440.
See Plate 72.
Fig. 18. Cardinal view of a partial cast of the interior, showing the posterior diverging furrows.
Hamilton group. Falls of the Ohio river.

Pakacyclas lirata.

Page 441.
See Plate 72.
Fig. 19. Cardinal viewiof a specimen showing the small diverging ligamental grooves.
Hamilton group. Cbarlestovm, Indiana.

Pakacyclas ? pauper.

Page 446.
See Plate 75.
Pig. 20. The left side of a specimen retaining both valves.
Chemung group. Portville, J^. Y.

Pakacyclas rotunda.

Page 444.

See Plate 63.
Fig. 31. A larg« right valve.

Chemung group. Broome Co., N. Y.

Pakacyclas erecta.

Page 44S.
Fig. 22. The right side of a specimen showing the form of the shell.
Chemung group. Warren, Pa.

PLATK XCV— Coiilimicil.

P.VKACYCLAS OlIIOENSIS.
Page Ui.

See Plate 72.
Fig. 34. The left side of a specimen showing the form and surface (■hiua<:t('i-s.
Hamilton group. tlUis of the Ohio river.

Paracyclas tenuis.

Page 443.
See Plate 72.

Fig. 25. The right valve, natural size, showing the form and surface markings.
Hamilton group. Stim-e of Skaneateles lake, N. Y.

ScHizoDUS, sp. uiKletcniniued.

Fig. 26. The interior of a left valve as obtained from a gutta-pereha impression showing the cai-dinal teeth,
muscular scars and pallial line.
Hamilton gi-oup. Pa.

SCHIZODUS OKEGAKIU8.
Page 4M.
See Plate 7.').
Rg. 27. A left valve, natural size.

Chemung group. Near Tioga, Pa.

' SCHIZOUUS EMINENS.

Pago 487.
Fig. 28. A larg^ right valve.

Chemung group. Near Guilford, Chenango Co., N. Y.

SCHIZODUS ii;QUALI8.
Pago 459.
See Plate 75.
Fig. 29. The left side of a specimen.

Waverly gi-oup. Licking Co., Ohio.

CyTHERODON NASUTU8.
Page fill.
See Plate 75.
Fig. 30. The left side of the typical specimen, which is a cast of the interior, showing muscular scare.
Hamilton group. Hardy Co., Va.

Dystactella subxasuta.

I'age 512.
See Plate 51.
Fig. 31. Cai-dinal view of a specimen i-etaining the test, showing the fold or callosity in front of the beaks.
Hamilton group. Near Louisville, Ky.

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palaeontology of N.T,7ol.V Pt.I

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PLATE XCVI.
Pholadella radiata.

Page 469.
See Plate 78.
Fig. 1. A cai-dinal view of a specimen showing the convexity of the valves.
Hamilton group. Near Cumberland, Md-l ,

Cypricardinia indenta.

Page 485.
See Plate 79.
Fig. 2. A right valve redrawn from the specimen fig. 7, plate 79.

Upper Helderberg group. Babcock's hill, iV. Y.

Cypricardinia consimilis.

Page 4t6.
See Plate 79.
Fig. 3. A right valve with the beak broken away.
Waverly group. Warren, Pa.

PAL.ffiANATINA SINUATA.
Page 491.
Fig. 4. A left valve .showing the foi-m and proportions.
Chemung group. Warren, Pa. '

Pkorhynchus quadratum.

Page 4<J2.

See Plate 79.
Fig. 5. A large left valve.

Chemung group. Near Smetbport, Pa.

Pkorhynchus nasutum.

Pago 493.
Fig. 6. A specimen retaining both valves in conjunction. The anterior nasute extension of the left valve
has been broken away.

Chemung gi-oup. Warren, Pa.

Pkorhynchus angulatum.

Page 493.
Fig. 7. A large right valve.

Chemung group. Warren, Pa.

Glossites ellipticus.

Page 498.
Fig. 8. The right side of a specimen with the valves partially open and attached by the ligament.
Chemung group. MansfuUl, Pa.

PLATE XCVI— Continuei).
Glossites LINOUAIJS,

rage m.
Fig. 9. A left valve of medium size.

Chemung group. Manjifield, Pa,
Fig. 10. A large left valve.

Chemung group. Mansfield, Pa.
Kg. 11. A small right valve somewhat constricted at the anterior''end.

Chemung group. Mansfield, Pa.

Glossites depuessus.

Pago 496.
See Plate 40.
Fig. 12. A left valve i-edrawn from the specimen tig. 17, plate 40.
Chemung group. Near Eliuira, N. T.

Glossites puocerus.

Page 499.
Pig. 13. A left valve showing the elongate form of this species.
Chemung group. Mansfield, Pa.

Glossites subnasutus.

Page 600.
Fig. 14. A left valve of this species.

Chemung group. Mansfield, Pa.

Glossites i'atdlus.

Page 501,
Fig. 16. A left valve.

Chemung group. Mansfield, Pa.
Fig. 16. A smaller right valve.

Chemung group. Mansfield, Pa.

Glossites uudicula.

Pago 498.
Pig. 17. A left valve of the ordinary form.

Chemung group. Nelson, Tinga Co., Pa.

Glossites teretis.

Pago 494.
Fig. 18. The right side of a specimen showing the form and surface markings.
Comiferous limestone. LiWeville, N. T.

Grammysia nodocostata.

Page 360.
See Plates 5."), 56, 57.
Pig8. 19-21. Left, right and anterior ^dews of a specimen pi-eserving nearly its normal form.
Hamilton group. Schoharie Co., N. Y.

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Paleeontology of NT.Yol.yR.I.

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QH Natural history of New York

105

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V.23

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