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RECEIVED BY GIFT FROM
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bag

NORTH AMERICAN
INDEX FOSSILS

INVERTEBRATES

BY

AMADEUS. W. GRABAU;«S:M.7 $:D.

PROFESSOR OF PALZONTOLOGY IN COLUMBIA UNIVERSITY

HERVEY WOODBURN SHIMER, A.M., Pu.D.

ASSISTANT PROFESSOR OF PALA ONTOLOGY IN THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY

VOLUME I

PROTOZOA, PORIFERA, HYDROZOA, ANTHOZOA, BRYOZOA, BRACHIOPODA,
PELECYPODA, SCAPHOPODA AND GASTROPODA

NEW YORK
A Gy SEILER &: COMPANY
1909

Copyrighted 1909, by
A. W. Grapau AND H. W. SHIMER

PRESS oF .
TRE NEW ERA PRINTING COMPANY
LANCASTER, PA.

PREBACE,

This work is essentially a treatise on North American index
fossils, 7. e., on those fossils best adapted for the determination
or geologic horizons. Its aim is to render possible in the laboratory

or field, ready identification of faunas and the correlation of .

horizons. It is to some extent also a text-book of paleontology,
and the needs of the student in this respect have been kept in
mind in its preparation; but the student of index fossils, who is.
preparing himself for work in stratigraphic paleontology, will
find this work especially planned for him; to meet his needs has
been the principal aim of the authors.

The zoological rather than the. stratigraphical arrangement of
the material seems most in harmony with this aim. Brief discus-
sions of the classes included in the book are followed each by its
own included genera. The description of each genus is followed
by its included species, with brief characterizations to distinguish
them. It is hoped that the generic keys at the beginning of each
class and the specific keys accompanying the fuller genera may
make relationships and differences more clear. The arrangement
of the species of any one genus is, as a rule, in chronologic succes-
sion from the lower to the higher formations. In some cases, as
in the Bryozoa, it has been possible to keep the species and genera
of the Paleozoic and Mesozoic eras distinct, since in America
they are separated by a wide gap owing to the relative incom-
pleteness of the basal Mesozoic marine series.

By this zoological arrangement attention is called to closely
similar genera and to still more closely similar species of one
genus and to the distinctions between them, in a manner not pos-
sible when species are grouped wholly on a stratigraphic basis.
Repetition of generic characters is likewise thus avoided. A trial
of both methods of treatment in class-room and laboratory work
aas convinced the authors that it is the comparative method, made

_ possible by a zoological arrangement, which gives the student of

fossils the best grasp of the subject. The first requisite in the

iil

iv PREPACE.

training of a stratigraphic paleontologist is careful attention to
details such as is necessary in the identification of species. From
this arises the ability to discriminate between closely allied species
of one genus but of different geologic horizons, and the associa:
tion, in this book, of all the more important species of one genus
is hence not only desirable but necessary. The field geologist who
may use the book for the determination of his fossils and his
horizons, will likewise appreciate the value of a zoological arrange-
ment, as the stratigraphic method would require a previous knowl-
edge of his horizons.

The faunal summary at the end of the work is especially addressed
to the needs of the student of faunas. Such faunal summaries
need no pictorial or graphic accompaniment. The student quali-
fied to use them will form mental images of the species on seeing
them listed, and it is only when the name stands for the species
in the mind of the student that he will be able to appreciate faunal
geography and chronology.

Little attempt has been made at a classification and grouping
into divisions of less than ordinal rank. In some cases even the
orders have been omitted, especially where such classification is
based solely upon anatomical characters of the soft parts of the
animals and is not in full agreement with the fossil remains. The

authors believe that a classification should be founded upon a basis

of phyletic principles and a thorough appreciation of anatomical
details and of the relationships of hard as well as of soft parts.*

A fair grasp of the diagnostic characteristics of a large number
of genera and species can not be other than helpful in the more
special study of genetic relationships, and such an acquaintance as
will be given by a study of American as well as foreign index
fossils, may well precede the more detailed anatomical and com-
parative studies which are the especial field of the professional
student of paleontology and zoology.

Much thought has been given to the selection of material from
the wealth of American species, it being manifestly impossible to
include all known species. Selection has been based on three cri-
teria. First to be included were the species most characteristic

* For a discussion of the interrelationships of the hard and soft parts of

invertebrates and a comparison of fossil with living forms, see the forthcoming
introduction to the study of fossils by H. W. Shimer.

_— oe ee AS

tee | Bie

PREFACE. Vv

of the important stratigraphic divisions, 7. e., those of wide hori-
zontal (geographic) but of limited vertical (stratigraphic) distri-
bution. Secondly those species which have a wide horizontal dis-
tribution even though their vertical range is also great, in other
words, the very common American species (e. g., Atrypa reticu-
laris) have been selected. Thirdly such species or representatives
of genera have been considered as desirable additions which, though
limited in distribution and in stratigraphic importance, yet furnish
illustration of characters.needed to be understood by the student of
structural or anatomical paleontology. That many species which
should be included have probably been omitted and others included
which could well be omitted, few will realize so well as the authors.

Only a minimum of pages of the present work are devoted to a
discussion of the anatomical characters of the classes, for in a
general study of index fossils a knowledge of only the larger struc-
tural features is absolutely necessary.

No descriptions of plants or of vertebrates are included. They
are so important and have such numerous representatives that
separate treatises are needed for their discussion. Certain groups,
as the arachnids, insects, etc., are treated only in a general way, as
their remains are so fragmentary as to be intelligible only to
specialists. Likewise other groups of limited distribution or of
little value as index fossils, owing to their rarity or poor preser-
vation, have here received only slight attention.

The nomenclature of geologic formations advocated by the Inter-
national Congress of Geologists is here adopted, since this embodies
a uniform system of endings for terms of the same value.

The authors will deem it a favor if users of this work will in-
form them of errors when detected, for errors are sure to be pres-
ent in a work of. this character, even though carefully guarded
against. Especially is this the case in the distribution ranges given
for the species. Discoveries, which are constantly made, will sub-
ject this part of the work especially to modification from time
to time.

In the preparation of the book the authors have enjoyed the
sympathetic helpfulness of many American paleontologists who,
as authorities in their special fields, have rendered invaluable aid.
While making special acknowledgments to only a few of them,

Vi PREFACE:

the authors wish to thank all who, in one way or in another, by
furnishing material, suggestions, illustrations, etc., or by criticism
have furthered this work. They can not forbear to mention their
special indebtedness to Professor John M. Clarke, who has gener-
ously loaned illustrations and in other ways has been helpful; to
Mr. E. O. Ulrich and Dr. R. S. Bassler; to Professors Cumings,
Sardeson and Stuart Weller; to Dr. C. P., Berkey and to Dr.
Percy E. Raymond, who has furnished a number of illustra-
tions and some descriptions, as well as lists of species. Spe-
‘cial acknowledgments are further gladly made to Florence Henry
Shimer, A.M., and to former. and present students of the
senior author, especially Elvira Wood, A.M., and Fred. K. Mor-
ris, A.B. The generous manner in which American state geolo-
gists and boards of surveys have illustrated their palzonto-
logical publications has made possible the full illustration of this
work; constant and free use has been made of all such publica-
tions with the full confidence that their authors and editors sanc-
tioned such usage. In all cases (except where omitted by
oversight) the source of the illustrations has been given. The
descriptive material has been largely adapted from the original
descriptions and figures, published in the volumes of the various
surveys, societies, universities, etc., aided and checked, as far as
possible, by examination of material from type localities.

The earlier chapters through the brachiopods appeared during

the years 1906 and 1907, being published serially in the Columbia
_ University School of Mines Quarterly. The remainder of the
work now makes its first appearance. The authors trust that it
may serve the needs of American students of paleontology and
stratigraphy, to whom it is cordially dedicated.

New York anv Boston,
October 1, 1909.

ee eee See ee

CONTR N TecOr NL URL ih.

MEEUTOR ICY Ns 3 9 Soe 5s Catal rae Re ae On 2 a ER) Beas I

Definition, 1. Influence of the Character of the Bottom and Sedi-
ment, 2. Types of Fossils: (1) Actual Remains, Molds and
Casts; (2) Trails, Tracks and Burrows; (3) Artificial Structures ;
(4) Coprolites, 3-4. Mode of Preservation, 4. The Naming of
Fossils, 5. Table of the Animal Kingdom, 6-7. General Refer-
ence Works, 7.

I CRON ACPA 3.5095 0551.2 car veh eve > nm! reco ann oh viplw Te ime ch de ol vs
I EE I Oe 90000) 0) Sa Or ee ae eae
Literature, 8. Synopsis of Important Genera and Species, 9.
eet? TOMI OIOTIO™ 26 eh os ee ees a wee eee 12
Ln EE OE 4 01 2, Sen a ee eo 13
Literature; 13. Synopsis of Important Genera and Species, 14.
Memmi tt). COLENTERATA |... ... ois... ee ca ce ite eae 20
SRO eed x yt eS oide 4 Vendo 4 ak ere Sew 20

Graptolites, 21. Literature, 22. Key to the Genera, 23. Synopsis
of Genera and Species, 24. Order 1—Dendroidea, 24. Order
II—Graptolitoidea, 27. Hydrocorallines, 34. Stromatoporoidea,
34. Literature, 36. Key to the Genera, 37. Key to the Species
of ‘Stromatopora’ in the Old Sense, Based Chiefly on External
Characters, 38. Synopsis of Genera and Species, 39.

Bene sa 10200 OF. ACHNOZOG 2) solo os eles oe es 47
Literature, 49. Key to the Genera, 49. Tetrameral Corals, 54.
Tabulate Corals, 78. Octameral Corals, 96. Hexameral Corals, 99.

SE. MOLLUSCOIDEA 8. 0a Siac ve cdecse ea teven das 107

SRE EVOLOG (TP O))200) 2 ok x ids nds bev od be oe 107

Literature, 109. Artificial Key to the Genera, 110. Paleozoic
Species, 116. Order Ctenostomata, 116. Order Cyclostomata, 118.
Order Trepostomata, 127. Order Cryptostomata, 140. Mesozoic
and Cenozoic Species; 166. Order Cyclostomata, 166. Order
Chilostomata, 169.

RCM HOVOOR sik) oped BG CN Oak Se PN Oe . 170

Literature, 176. Artificial Key to the Genera, 177. Atremata,
188. Neotremata, 199. Protremata, 209. Telotremata, 281.

vil

Vili CONTENTS.

Phylum V. Mottusca te A

io:
2

Class “Pelety pO aii Wore CR ice iid an «Ts aca in g Ke er

Order 1—?

Literature, 363. Artificial Key to the Genera, 364. o
Order 2—Anomalodesmacea, 522. Order —

Prionodesmacea, 375.
3—Teleodesmacea, 533-

,

Class Scaphopoda Re

Nm
a.

Family Dentaliide, 578. Family Siphonodentaliide, 581.

= i

Class Gastropoda Rey er ac a

Literature, 584. Artificial Key to the Genera, 586. 7
branchia, 603. Opisthobranchia, 806. Pulmonata, 811. Hetero- |
poda, 823. : ; La :

INDEX ov GENERA, «fey ge Gisic, tet ns -n ie

r

~ } » ina ‘
Sem Re

gt di Min yi te rue sf ’ “y Ps ra Py 2
kh te 4 ae PN OR AY SPE yy pS we

NORTH AMERICAN INDEX FOSSILS.

INTRODUCTION.

Fossils are the remains of animals or plants, or the-direct record
of their presence, preserved in the rocks of the earth’s crust from
the earliest to the present time. They are the only reliable means
by which the age of any geologic formation can be determined,
and, as such, are of the utmost importance to all geologists deal-
ing with the non-igneous rocks. Not all fossils are equally good
indices of the age of the formation in which they occur, for some
are of very great vertical, and others of very limited horizontal dis-
tribution. It is evident that neither will serve as a good index
type. The best index fossils are those which combine a wide hor-
izontal with a limited vertical distribution, such as the graptolites
or the ammonites.

In general it may be said that the more precise the required
identification of a horizon the more limited must be the range of
the fossil or fossils which are relied upon to indicate that age.
Thus while trilobites as a class may be relied upon as indicators of
Palzeozoic age, being unknown above this, a certain group of trilo-
bites alone will serve to indicate Cambric age, while a genus (O/en-
ellus, or Paradoxides) serves to indicate the lower or middle Cam-
bric respectively. Furthermore, a certain group of species of Para-
doxides, as for example the species of the P. e/eminicus type, serve
to indicate a certain horizon in the Middle Cambric.

It often happens that the fossils of a certain formation in a given
region include no species of a restricted type, such as would indi-
cate the exact equivalency of this formation with the ascertained
horizon characterized by such a species in the type section.
Under such circumstances it is necessary to determine the position
of the formation in question by its assemblage of animal remains
or fauna or the assemblage of plant remains or flora.

I I

2 NORTH AMERICAN INDEX FOSSILS.

For example we may assume twenty species of organisms rang-
ing through five formations, 4 to &, in the type section, as shown
in the annexed diagram. It is evident that species 12 to 16 are
the special indices of the formations E to A, respectively. We
will now assume that a formation in another, not too far re-
moved, region, contains none of these but has the following species
generally abundantly represented: 2, 3, 6, 8, 17, 18, 19, while
more rarely represented are: I, 5 and 10. It is clear that this as-
semblage or fauna is most like that of formation C of the type sec-
tion, even though species 14, the special index species of that for-
mation, is wanting.

SIL te
Cees

minima
A eee

123456789 10 11 12:13 14 15 16 17 16 40700

Influence of the Character of the Bottom and Sediment. —In the
above illustration, the application is most reliable if the character
of the sediment is similar to that of the type section, indicating
similar conditions of existence. It is well known that with the
change in sedimentation occurs a change in fauna, whole classes
of organisms disappearing and new ones appearing. Thus nothing
can be more distinct than the calcareous beds of the Beekmantown
horizon of some parts of the Champlain Valley, with their trilobites,
cephalopods and gastropods, and the black shales of the same age
in the Hudson Valley, which contain only graptolites. It thus
becomes necessary that the fossils of the formations of the type
section should be determined for the different phases of occurrence.
This is necessary because each formation has normally an off-shore
or pure water (generally calcareous) facies and a shore facies con-
sisting commonly of quartz sands or even conglomerates, while
between these two are various transition facies.* Furthermore
a marine formation may in another region be largely represented

* The principles here touched upon are fully treated in the forthcoming ‘‘ Principles
of Stratigraphy ’’ by the senior author.

TYPES OF BOSS LES: 3

by a continental formation, z. ¢., a lake, river, or wind deposited
formation. Examples of such more or less equivalent marine and
non-marine formations are the Chemung and Catskill, the Pierre
and Belly River, and the marine Tertiaries of the Atlantic and
Gulf Coasts and the non-marine Tertiaries of the plains and Great
Basin region. *

Types of Fossils. —¥our types of fossils may be recognized,
namely : (1) Actual remains and their impressions; (2) trails and
tracks made by organisms in transit, and burrows; (3) artificial
structures; (4) coprolites.

1. Actual Remains. — Generally only the hard parts of animals
will be preserved but occasionally the fleshy parts also remain.
Examples of this are the mammoths and other animals preserved
in Siberian ice and the Tertiary insects of the amber found on the
shores of the Baltic. The hard parts most readily preserved are
the bones of vertebrates, the plates and spines of the external
armor of fishes and ‘reptiles, the exoskeleton of crustacea, the
plated armor or test of echinoderms, the shells of mollusks and
brachiopods, the “ coral ” structures of Bryozoa, corals, and hydro-
corallines, and the shells of Protozoa. The horny covering of hy-
droids is also more resistant than other soft animal tissue and is
commonly preserved in the form of carbonaceous films. Plant
tissue is more readily preserved than animal tissue; especially is
this true of wood, which is commonly preserved by being vari-
ously impregnated or replaced.

Molds and Casts—Frequently the actual remains of the organ-
ism decays or is dissolved, leaving only a mold behind; when the
structure was hollow, as in the case of shells, both external and in-
ternal molds (the latter often called casts) remain. Occasionally,
by the infiltration of mineral matter into the mold, a cas¢ of the ori-
ginal shell is produced. Inthe study of molds artificial casts must
frequently be made.+

2. Trails, Tracks and Burrows.— Foot-prints of vertebrates on
soft mud or sand and trails of worms, mollusks, or crustacea are often
preserved. Here no part of the animal remains, nor is this the only

*See the table of formations in the appendix (published with the last install-

ment).
+ For processes of making these see appendix.

4 NORTH, AMERICAN INDEX FOSSILS.

impression made by the animal, as in case of the molds of a shell.
Burrows of worms or other animals are more or less permanent
homes, and are often reénforced by walls made of agglutinated sand
particles. They then partake of the character of artificial struc-
tures, and they may be considered as intermediate between classes
2 and 3.

3. Artificial Structures. — Here belong the tubes built of agglu-
tinated sand grains by worms, the “shells” built of similar foreign
particles by many Foraminifera, and more especially the imple-
ments, habitations and other structures left by primitive man in the
later rocks of the earth’s crust, as well as the structures buried in
historic times.

4. Coprolites.— The excrements of many animals are character-
istic, serving to determine their presence in the formation in ques-
tion. Typical examples of these are the coprolites of Jurassic and
Cretacic reptiles.

MopE OF PRESERVATION.*

Under this heading we need to consider only the preservation of
the actual remains (hard parts) of animals and plants.

Burial and Removal of Organic Matter.— The first step in fos-
silization is of course burial, for without that even the hard parts
will soon be destroyed. This is well illustrated by the disappear-
ance, largely through decay, of the bones of the American bison,
which were left unburied in countless numbers on the western
plains. It is also illustrated by the annual decay of the fallen
leaves. After burial the organic tissue which forms the frame-
work of all hard animal structures is removed by decay, thus ren-
dering the remains more or less porous. This is well seen when a
fresh bone is compared with one buried for some time. Tertiary
shells often show the porosity due to the removal of the organic
framework. This porosity is indicated by adhesion to the tongue,
to the touch of which fresh shells feel perfectly smooth.

L[nfiltration. — Sooner or later the pores left by the removal of
the organic matter are infiltrated with lime, silica or other mineral
matter, the organism thus becoming completely petrified or turned
to stone. When silica infiltrates it tends to replace the original

* For a full discussion of this see Grabau, A. W., ‘ Principles of Stratigraphy.”

MODE OF PRESERVATION

NAMING OF FOSSILS. «

lime of the fossil, and in the end completely silicify it. Such silic-
ification is commonly indicated by the formation of ‘ Beekite
rings,’ numerous small rings scattered over the surface of the shell
or coral, and having at their centers a tubercle of silica. Silicified
fossils commonly weather out in relief (though this is true also of
calcified fossils), and they may be separated from calcareous rock
matrix by acid. Silicification commonly destroys the minute
structure of the organism while preserving its form. Many other
minerals replace organisms, most common next to silica being
iron pyrites. Wood may be partially or wholly silicified. In
the first case the silica merely fills the cells and ducts, while in
the second case the woody tissue is also replaced. Leaves may
leave a picture of themselves in precipitated iron oxide, or they
may be replaced by various minerals, or merely remain behind as
a film of carbon.

Distortion often results from silicification, while crystallization
frequently accompanies calcification, especially among the echi-
noderms.

Mechanical Deformation. — When rocks have suffered compres-
sion, fossils are commonly distorted. When the pressure is ver-
tical the fossils are flattened out. This is frequently the case in
undisturbed shales, where the compression of the beds, through
pressure of overlying rocks, flattens out the shells, which in inter-
calated limestones or sandstones retain their normal form and ro-
tundity. Where lateral compression has affected the strata various
distortions result, which often may make the determination of the
fossil a matter of difficulty. Brachiopod shells may in this way be
made to resemble pelecypod shells.

THE NAMING OF FOSSILS.

Each fossil is designated by a binomial term, the first part of
which is the gezeszc and the second the specific name. Generic
names are written with an initial capital letter, specific names always
begin with a small letter, even if derived from proper names.
Thus Heliophyllum hall is correct, while Heliophylum Hall is in-
correct. The ending of the specific name (except nouns) must cor-
respond to the gender of the generic name. The common endings
are US, a, um, or 7S, 7S, é, for masculine, feminine and neuter gender,
respectively. Specific names derived from proper nouns remain

6 NORTH AMERICAN INDEX FOSSILS.

the same for all genders and commonly'terminate in z. The Greek
ending ozdes remains the same in all genders. A generic name be-
comes a synonym when it is found that the same name has pre-
viously been used for an organism of another genus. It must then
be replaced by another name. A specific name becomes a syno-
nym when the genus in which it belongs already has a species
of thatname. Different genera may havespecies of the same name.
Sometimes an author describes and figures under the same name
several forms which are subsequently found to belong to distinct
species or even genera. In all such cases new names must be
used, the old names becoming synonyms for that species or genus,
though holding good for the forms to which they were originally
applied. In some cases a species or genus already named or a
form belonging to a species or genus already established is given
a new name by a later author. This new name then becomes a
synonym and unless restored to rank subsequently for the type for
which it was proposed, has no value whatever, but is dead. It can
never be used again.

TABLE OF THE ANIMAL KINGDOM.

The following table of the animal kingdom takes account only
of those classes which are represented among fossils, or, in other
words, only such which have hard parts capable of preservation.
The classes and subclasses in italics will be omitted in the succeed-
ing discussions :

Phylum. Branch. Class. Subclass.
( Mammalia.
| Aves (Birds).
TRS OW CLteRVAta! (cue 0n bes {4 Reptilia.
| Amphibia.

| Pzsces (Fishes).

(

Holothuroidea (Holo-
thurians. )

Echinoidea (Sea Urchins ).

|

}

|

L

f

| Asterotdea (Starfish).
VIII. Echinodermata.,. { Ophiuroidea (Brittle
|

stars).

Crinoidea.
{ Blastoidea.
| Cystoidea.
L

ee

Pelmatozoa. Asterozoa. Echinozoa.

PROTOZOA. 7

Phylum. Branch. Class. Subclass.
( Insecta.
Myriopoda.
Aveta Arachnida (Spiders).
ge eee cau ak Merostomata ( Eurypterids, etc.).
VII. Arthropoda..... 4 ( Malacostraca (Lobsters, Crabs).
| Cirripedia ( Barnacles).
RTMSER CED 5 Sens n't easton canis te Ostracoda.
Phyllopoda.
| | Trilobita.
We, enulosa............ Annelida.
( Cephalopoda.
| Pteropoda.
| Conularida.
Gastropoda.
V. Mollusca......... ape pier
Scaphopoda.

| Pelecypoda (Lamelli-
| branchiata).
Brachiopoda.
Bryozoa.
Anthozoa (Corals).
atl, <clenterata ..... Hydrozoa (Hydroids and

IV. Molluscoidea* .,

Hydrocorallines).
Se POmMeTA,........0+... (Sponges. ) ies
PEE MOLOZOG ...c..0e0sss BUM ZO POS. Gyo ons fewer psicogy ss ae -

General reference works:

Mitier, S. A. North American Geology and Palzontology:
1889 and appendices (lists all Palaeozoic species with reference to
literature).

Boye, C. B. Catalogue and bibliography of North American
Mesozoic Invertebrates, 1893 (with reference to literature), Bull.
U. S. Geol. Surv., 102.

WELLER, Stuart. Bibliographic index of North American Car-
boniferous invertebrates, 1898 (with synonymy and reference to
literature), Bull. U. S. Geol. Surv., 153.

Puoytum I. PROTOZOA.

These are the simplest types of animals, with a body consisting
of a single cell. Only two subclasses build hard structures which
may be preserved as fossils. These are the Foraminifera and the
Radiolaria. The first build external shells of lime, chitin or agglu-
tinated sand particles; the second secrete more or less internal
skeletal elements of silica and generally of an open lattice-like
structure.

* Placed here for convenience so as to bring the Bryozoa and Corals together,
many fossil forms of which are superficially alike,

8 NORTH AMERICAN INDEX FOSSILS.

Subclass 1. Foraminifera d’ Orbigny.

The shell may consist of a single chamber (unilocular) or of
many chambers (multilocular). The chambers may be arranged in
a straight line (nodosarian type, Fig. 1), wound in a horizontal
manner (nautiloid type, Figs. 2, 3), in a spiral manner (trochoid

Fics. 1-6. Diagrams illustrating types of Foraminiferal Shell (after Bagg).

type, Fig. 4), alternating in a double series (textularian type, Fig,
5), regularly embracing the preceding chamber (milioloid, Fig. 6),
irregularly clustered (globigerinoid, Fig. 14), simple globular (orbu-
linoid, Fig. 13), or wrapped about an imaginary axis — either disk-
like (orbitoid, Fig. 19) or spindle-shaped (fusoid, Fig. 18). The
shell is either pierced by numerous pores or foramina (perforate) or
is imperforate. A terminal or oral opening is generally present.
The shell is asecretion of lime or results from cementation of sand
grains (Fig. 11). |
Owing to the fact that the Foraminifera vary but slightly from the
upper Paleozoic to the present, they are of very little use as index
fossils. A few of the more abundant genera are here given in
order that they may be recognized as such. A few species which
are restricted in their geological range and are found in great
abundance are described.

LITERATURE.

1876. Brady, W. B. Monograph of Carboniferous and Permian
Foraminifera, Palzeontographical Society Monographs.

1884. Brady, W. 8B. Report on Foraminifera, Scientific Results,
Challenger Expedition. Zodlogy, XI.

1893. Woodward, A.,and Thomas, B. Cret. Foraminifera, Minn.,
Neb. and Ill. Minn. Geol. Surv., III., 28. “

1898. Bagg, R. M. Crét Foraminifera, N. J.» Bull: U.S. Gag
no. 88.

FORAMINIFERA. 9

1900. Chapman, F. Foraminifera from the Tertiary of California.
Proc. Cal. Acad: Sci, Ser:.3; Vol. Ji, -ppy: 247 26oy plese, Ax

tg01. Bagg, R. M. Eocene Foraminifera. Md. Geol. Surv. Rept.

1904. Bagg, R. M. Miocene Foraminifera. Md. Geol. Surv. Rept.

1905. Bagg, R.M. Miocene Foraminifera of California. Bull. U..
ta. no. 268.

SYNOPSIS OF IMPORTANT GENERA AND SPECIES.

I. PENEROPLIS Montford.

Shell a flattened cornucopia, with the small
end spirally enrolled and chambers extending
the entire width of the shell. Tertiary—Re-
cent.

Fic. 7. Peneroplis 1. P, planatus Montf. (Fig. 7.) Recent.

planatus, greatly en-
larged.

II. CrisTELvArIA Lam.
Shell regularly spiral. with coils completely enveloping one
another. Oral opening round. Trias—Recent.
2. C. cultrata Montf. (Fig. 8.) Cret.—Recent. 3. C. cretacea
Bagg. (Fig. 9.) Cretacic.

Fic. ga-b, Crystellaria cretacea ;
15, Anomalina ammonoides ; 11, Verneuilina triguetra ; 8, Crystellaria cultrata
- (all after Bagg), greatly enlarged.

III. Texturaria Defrance.
Chambers in two rows, alternating with each other and gradually

ice) NORTH AMERICAN INDEX FOSSILS.

increasing in size. Aperture usually an arched slit at the base of

the inner wall of the last chamber. Carbonic—Recent.

4. T. globulosa Ehr. (Fig. 10.) Cret.—Re-
cent. 5. T. (Verneuilina) triquetra
(Minst.). (Fig. 11.) Cret.—Recent.

NODOSARIA.

Chambers in a single row, smooth or or-

namented. Siluric (?)—-Recent. EN

6. N. communis (d’Orb.). (Fig. 12a. ae ee —
Perm.—Recent. 7. N. bacillum Defrance. ury.) eh aoe
(Fig. 126.) Eocenic. 8. N. zippei, Reuss (Fig. 12c.) Cretacic.

V. Orsuina d’Orbigny.

Shell a simple sphere with a large oral
opening and numerous foramina. (Cambric ?)
Trias—Recent.

9.0. universa d’Orb. (Fig. 13.) Trias—Recent.

Fic. 12. a, Nodosaria
communis, 6, N. bacil- Fic. 13. Orbulina universa.

lum; c, N. sippet (a-, Fic. 14. Globigerina bul- Fic. 16. 7runcatulina
Md. Geol. Surv.; ¢, J/ozdes (Minn. Geol. Surv.), lobatula (Md. Geol.
Bagg), greatly enlarged. much enlarged. Surv.), enlarged.

VI. GLOBIGERINA d’Orbigny.

Free, calcareous, perforated by coarse tubules. Composed of
several globular chambers, which are irregularly arranged or inan
imperfect spiral. (Cambric?) Trias-
sic—Recent.

10. G. bulloides d’Orb. (Fig. 14.)

Cret.—Recent.

Gloligerina, Textularia, etc., are very
abundant in the American chalk (Ni- Fic. 17. Endsdhre aaa
obrara) and also in the Atlantic and (after Whitfield), much en-
Gulf Tertiary. larged.

FORAMINIFERA. II

VII. ANoMALINA d’Orbigny.
VIII. TRuncatuina d’Orbigny.

Nautiliform or trochiform shells, the first nearly uniformly coiled,
the second flat on one side, while on the other side the last volution
covers most of the preceding ones. Carbonic—Recent.

11. A. ammonoides (Reuss). (Fig. 15.) Cret.—Recent; 12. T.
lobatula (Walk. & Jacob) (Fig. 16) Carb.—Recent.
IX. Enpotuyra Phillips.

Free, calcareous, irregularly spiral. Chambers numerous.
General aperture porous.
Abundant in Carbonic and continuing doubtfully to Recent.

13. E. baileyi Hall. (Fig. 17.) Lower Carbonic.

Sp

Fic, 18. sulina secalica (Ind. Geol. Fic. 19. Orbztoides mantefli. Outline and
Surv. ), natural size and enlarged. enlargement of peripheral portion.

Shell compressed, usually consisting of two or three oblique
convolutions of which little more than the last is visible on the
exterior. Margin thick, rounded, lobulate. Chambers inflated,
separated by depressed septal lines, variable in number from seven
to ten in each whorl. Diameter , to 4, inch or more.

Very abundant in Mississippian of southern Indiana.

X. CALCISPHERA Williamson.

Free, consisting of two thin-walled concentric chambers with
terminal apertures. Inner chamber smooth with tubular prolon-
gations at the ends. Outer chamber spirally marked. Texture
arenaceous compact. Resembles organs of fructification of Chara
with which it has been identified. Devonic—?

14. C. robusta Williamson. Dev.—Carb.

Shell nearly globular, about 1 mm. in diameter, with polar aper- |
tures. Wall composed of minute calcareous grains, smooth in-
teriorly. Outside banded by nine strongly defined regular spiral
ridges.

Onondaga limestone of Indiana, Kentucky and Ohio.

2 NORTH AMERICAN INDEX FOSSILS.

XI. Fusuzina Fischer.

Fusiform, laterally elongated and furrowed, coarsely perforate.
Chambers subdivided by numerous septa.

Exceedingly abundant in the Carbonic of North America, Europe
and Asia. Carbonic—Permic.

15. F. secalica (Say). (/ cylindrica Fischer.) (Fig. 18.) Car-
bonic.

Spindle-shaped, with rounded extremities, which generally have
the appearance of being slightly twisted. Volutions six to eight
and closely coiled. Sometimes one half inch long. 3

Widely distributed throughout the Middle and Upper Carbonic.

XII. Orpitoipes d’Orbigny.

Discoidal. Exterior smooth or ornamented with radial strie.
Composed of numerous concentric rings, which are divided by trans-
verse partitions into small rectangular chambers. A median series
of main chambers occurs. Upper Cretacic and Tertiary.

16. O. mantelli (Morton). (Fig. 19.) Oligocenic.
Discoidal, flattened, thin, thickest at center and tapering from
there to the sharp margin. Diameter % inch to I % inches.
Very abundant in the lower Oligocene (Vicksburg) beds through-
out the Gulf states, often forming beds of limestone.

Subclass 2. Radiolaria Miller.

The siliceous skeletons of these Protozoa are usually too much
broken for identification. In exceptional cases, as in the Miocene
of the Barbadoes, they are exceedingly numerous and well pre-
served. (Fig, 20.)

Fic, 20. Radiolaria. a@-é (upper left), Rhopalodictyum marylandicum ; Cano-
sphera porosissima; c, Hexalonche microsphera ; d, Anthocyrtium doronicum; e, Can-
nartiscus amphicylindricus. All Miocenic (Maryland Geol. Surv.), much enlarged.

Puytum II.

PORIFERA.

13

PORIFERA (SPONGES).

Multicellular animals, chiefly marine; body penetrated by a
complex series of canals, into which the water enters by the

pores of the wall.

FIG. 21.
showing: the structure of a simple
~ The
sponge substance (//) is lightly
shaded. The canal system is black,
the arrows showing the direction
of thecurrents. //, are the pores
or openings of the inhalant canals
(epirrhysa) which lead to the
flagellate chambers, cz. From the
latter depart the exhalant canals
(aporrhysa), 2c, which open into
‘the general cavity or paragaster. 09,
is the osculum or aperture through
which the water is discharged.
‘Haeckel, in Hall and Clarke. )

Diagrammatic figure

sponge in vertical section.

These canals widen out into, or give off at

intervals digestive chambers, and fin-
ally converge into one or more large
canals which open on the upper side
of the sponge in large craters or os-
cula. (Fig. 21.) Most modern sponges
secrete a-skeleton of horny fibers,
which is frequently reenforced by sili-
cious spicules of various forms. In
many extinct types these spicules were
the most prominent structure, and fre-
quently became thickened and united
to form a solid trellis or framework
which retained the form of the sponge
on fossilization. In some sponges this
framework is regularly reticulated, in
others it consists of very irregular
branching spicules, while in_ still
others it is apparently a solid mass
of spicules. Some forms (Dectyospon-
gia, etc.) were apparently delicate nets
of siliceous fibers, the form and im-
pression of these being preserved by
the infiltrated sand as an internal
mold.

Sponges as a rule are poorly pre-
served and difficult of determination.

They have been but little studied in this country.

LITERATURE.

1860. Roemer Ferd. Silurische Fauna des Westlichen ‘Tennessee.
1889. Beecher, C. E. Brachiospongide, Mem. Peabody Mus. Yale.

mer. LL, pt. T.

1898. Hall, J., and Clarke, J. M.

Paleozoic reticulate sponges.

Mem. II. N. Y. State Museum. Also papers by Whitfield Hall and

others.

14 NORTH AMERICAN INDEX FOSSILS.

SYNOPSIS OF IMPORTANT GENERA AND SPECIES.
I. ASTYLOSPONGIA Roemer.

Free, spherical, with a shallow depression on top. Base evenly
rounded. Surface furrowed by large canals and pitted with pores,

Fic. 22. <Astylospongia premorsa, with enlarged section (Roemer).

which terminate many fine radial canals. ‘Spicules four-rayed and
branching, with their nodes enlarged into knots. Siluric.

1. A. premorsa Goldfuss (Fig. 22). Siluric.

Summit shallow and pierced with many large holes. From the
edge of this depression radiate shallow furrows irregularly over the
sides.

Niagara of Indiana, Tennessee, etc.

2. A. inciso-lobata Roemer. Siluric.

Differs from A. premorsa in the absence of large pores above and
in that the furrows number but six to eight and are deeply incised,
thus dividing the surface into large, rounded lobes.

Niagara of Tennessee.

II. HinpiA Duncan.

Free, spheroidal. Spicules form a series of bifurcating, straight
canals radiating from the center and opening at the surface.
Siluric.

3. H. fibrosa Goldfuss. Ordovicic-Siluric.

Ball-shaped, about one inch in diameter. Surface covered with
very small, irregular, polygonal openings.

Reported from the middle and upper Ordovicic, the Siluric and
even the Helderbergian.

III. DicryosponeiA Hall and Clarke.

Subcylindrical, very gradually expanding. Smooth, with no
ornamentation except the reticulated meshwork of spicular threads.

PORIFERA. 14

Prism faces sometimes very obscurely developed toward the sum-
mit. Occurs as internal molds.

Characteristic of the Chemung and occurs also in the upper
Portage and Keokuk.

4. D. sceptrum Hall. (Fig. 23.) Upper Devonic.
Elongate, usually abnormally compressed. Surface covered
with coarse, transverse spicular bands from 10 mm. to I5 mm.

Fic. 23. Dictyospongia sceptrum < Vy (Hall & Clarke, N. Y. State Mus. ).

apart and crossed by less conspicuous vertical bands about 5 mm.
apart.

In the shaly sandstones of the upper part of the Chemung
group in New York.

IV. PrismopictyaA Hall & Clarke.

Elongate, usually slender, gradually expanding from the acute
base. Surface sharply prismatic, with eight faces reticulated by

16 NORTH AMERICAN INDEX FOSSILS.

spicular threads and rarely ornamented with inconspicuous nodes

Found as internal molds.
Characteristic of the Chemung and occurs also in the upper

Portage and the Keokuk.

5. P. prismatica Hall. (Fig. 24.) Upper Devonic
Often without perceptible expansion for a considerable distance

but usually expanding to an aperture whose diameter is the greatest

cueey

Fic. 24. Prismodictya prismatica (after Fic. 25. Hydnoceras tuberosum (alter
Hall). Hall).

width of the sponge. Sometimes curved or twisted. Prism faces
flat and each marked with one or two clearly defined spicular
threads and other minor ones.

Chemung of New York, Pennsylvania.

PORIFERA. 17

V. Hypnoceras Conrad.

Obconical, more or less rapidly expanding from an acute base.
Surface at first smooth except for the reticulated spicular threads,
but soon developing eight prism faces and prominent nodes in hori-
zontal and vertical rows. ‘These nodes usually lie at the intersec-
tion of adjoining prism faces and are connected with one another
in vertical rows by short prominent lameliz. Occurs only as in-
ternal molds.

Characteristic of the Chemung. Occurs also in the Portage and
Waverly.

6. H. tuberosum Conrad. (Fig. 25.) Upper Devonic.

Large. ‘Transverse section usually subelliptical from compres-
sion. Horizontal rows of nodes not exceeding four or five in ma-
turity and separated by broad
concavities. Vertical rows
eight and separated by con-
cavities. Surface regularly
reticulated by vertical and
horizontal series of spicular
bands.

Lower and Middle Che-
mung sandstones in New

York.

VI. BRraAcHriosponciA Marsh.
Fic. 26. Brachiospongia digitata, reduced

(Beecher’s mem.). Skeleton enclosing a hollow

central cavity which sends
out large hollow arms, closed distally. Wall thin and bearing a
net-work of spicules. Ordovicic.

7.. B. digitata (Owen). (Fig. 26.) Ordovicic.

Arms eight to eleven, radiating from circumference of body ;
at first they pass off horizontally, then turning at right angles
they rise nearly vertically. Size from six inches to one foot in
diameter.

Trenton of Kentucky. -

VII. AsTRAZ0SPONGIA Roemer.

Thick-walled, bowl-shaped. Upper surface concave, lower con-

vex, without traces of attachment. Skeleton composed of rela-
2

18 NORTH AMERICAN INDEX FOSSILS.

tively large, eight-rayed spicules, six of which are disposed in the
same plane while the two projected at right angles to these are
reduced to button-like prominence. Siluric.

8. A. meniscus Roemer. (Fig. 27.) Siluric.

f
RPE OY WEL OYE
ee ON
Ue SSIS
Wor ies

Fic. 27. Astreospongia meniscus with enlargement of spicule ¢ (Roemer).

Vertical section crescent- (meniscus) shaped. Star-shaped spic-
ules very conspicuous, especially on the concave surface.
Upper Siluric of Tennessee.

VIII. Recepracutites Defrance.

Globular to platter-shaped bodies, containing a central cavity
whose calcareous wall is composed of five-rayed spicules. Ord. to
Dev.

9. R. owen Tall) (Pig: 28.) Ordovicic.

Broad, varying in diameter froma few inches to two feet. Con-
sisting of a flat, circular disc with a small, funnel-shaped central
depression above, corresponding to the narrow projecting base of
attachment on the under side. Cell rows curving strongly as they
radiate from the center. Cell apertures quadrangular at surface,
becoming circular and decreasing in diameter towards the center.

PORIFERA. 19

The characteristic fossil throughout the lead region, of the
Galena limestone in Illinois, lowa and Wisconsin.

Fic. 28. Receptaculites owent (Minn. Geol. Surv., Schuchert & Winchell).

10. R. hemisphericus Hall. Siluric.
Small, rarely exceeding two inches in diameter. Hemispherical

or subglobular with truncated base. Cells in rows obliquely

radiating from a sub-central point, minute near point of origin but

rapidly increasing in size over the upper surface and again decreas-

ing down the sides. |
Niagara of Wisconsin.

11. R. ohioensis Hall & Whitfield. (Fig. 29.) Siluric.
Differs from FR. hemisphericus in its smaller size, not exceeding
one and one fourth inches in diameter, and in its smaller cells.
Niagara of Ohio.

12. R. mamillaris Walcott. Ordovicic.
Usually in form of an inverted cone with
a deep depression above. In more ex-
panded forms the center of the otherwise
broadly rounded base extends as a short-
pointed projection.
In upper portion of the Pogonip group

Fic. 29. Receptaculites
ohioensis (Ohio Geol, Surv. ).

(= Chazy) in Nevada.

13. R. (Ischadites) iowensis (Owen). (Fig. 30.) Ordovicic.
Base concave, upper surface, flatly dome-shaped, with an open-
ing into the hollow cavity. Small rhomboidal cells opening on
surface in curved rows, intersecting in arches.
Galena limestone of Iowa, Wisconsin and Minnesota.

20 NORTH. AMERICAN INDEX FOSSILS:

Puyium III.

COALENTERATA.

Class Hydrozoa Huxley.

This class comprises the modern hydroids, delicate moss-like
animals, mostly growing in branching clusters or colonies having a

common stem or acommon base. A
few simple forms occur in fresh wa-
ter ({/ydra), but with only one ex-
ception, the branching and clustered
species are all marine. They are
commonly found attached to the sea-
weed fringing our rocky shores, or
growing in the deeper waters, though
many also grow on rocks, where they
are attached by a network of delicate
root-like stolons, while others again
are attached to shells or live partly
buried in the mud.

Hydroids of the modern type are
rare in the fossil state, but two aber-
rant groups the Gvapéolites and the
Hydrocorallines are abundantly repre-
sented in American strata. It will

Te

QS

~<a -
——

ind
~~
Paes
> on

=
es

Fic. 30. Jschadites towensts
(Minn. Geol. Surv.).

be necessary, however, to briefly consider the characters of a mod-

Fic. 31. Sertularia pumila
Recent (after Nutting). 4, polyp;
ht, hydrotheca; yg, gonotheca
(much enlarged).

ern hydrozoan in order to understand
the essential characteristics of the ex-
tinct species. For this purpose, Serzu-
laria pumila (Fig. 31), a type abund-
ant on the rock-weed all along the
north Atlantic coast, will be selected,
since in its general form it suggests the
characteristics of the Grapéolites, though
in reality quite distinct from them. ?

In general appearance this species
resembles a delicate plant, consisting of
branching stems furnished with a double
row of opposite teeth, like those of a
saw. Under the microscope it is seen
that the organism consists of two es-

sential parts, easily distinguished if the specimen is properly stained

GRAP LPOLTT ES: at

and well mounted. In the center is the animal proper, consisting of
an elongated hollow stem,from which at regular intervals arise a pair
of opposite flower-like heads or folyps, connected with the stem by a
narrow. ‘‘neck.” The polyps form the swollen end of each tube,
which at the summit is contracted into a narrow opening, the mouth,
and furnished some distance below the summit with aring of Zenta-
cles. The hollow internal space or stomach cavity of each polyp is
continuous through the “ neck” with that of the main stem, which
in turn through the hollow tube of the rootstock is continuous with
that of other stems of the colony. At intervals peculiar large
polyps without mouth or tentacles occur, which serve the function
of reproduction. Insome types of hydroids free-swimming medusz
or ‘‘jelly-fish” are produced by these reproductive or gonopolyps.
Enveloping the rootstock, stems and branches, is a transparent
membrane composed of the organic substance “ chitin,’ which is
similar to the material of which sponges consist. This envelope
or periderm widens around the polyps into cups or hydrothece, into
which the polyps can withdraw by muscular contraction, after
which the opening is closed by a lid or operculum. In the figure
one of the polyps is expanded, the others are contracted or not
shown. The gonopolyps are surrounded by a bottle-shaped cup or
gonotheca, which has a short neck and broad opening. The sub-
stance of the periderm is such that it may be preserved in the form
of a carbonaceous film.
GRAPTOLITES.

The simplest groups of Graptolites (Axonolipa), characteristic of
the highest Cambric and lower half of the Ordovicic, are derived
by a succession of buddings from a primal hydrotheca known as
the szcula. If the first two buds extend in opposite directions, the
result is a type with branches composed of a single row of hydro-
thecz. These may be strung out in long rows, where each suc-
ceeding hydrotheca buds from near the margin of the preceding
one (Fig. 46), or they may bud rapidly so as to overlap each other.
In the former case the serrations are far apart; in the latter, which
is the more specialized, they are close together. When the first
two buds give off two buds each, four branches result ( 7e¢ra-
graptus) instead of two (Lidymograptus). If later buds again give
off two instead of one bud, a larger number of branches is produced
(Staurograptus, Dichograptus, etc.). When the branches are nu-
merous and united by cross-bars or dissepements a net-like struc-

22 NORTH AMERICAN INDEX FOSSILS.

ture is produced (Dictyonema). When the original buds from the
sicula are completely turned back upon themselves, so as to open
in the opposite direction from the sicula, and grow together,
back to back, a double-rowed structure is produced with hydro- ~
thecz on opposite sides of the median line. Types of this kind
(Diplograptus, Climacograptus) are reénforced by a median axis or.
rod, the zzr~gula, which extends the entire length of the branch and
beyond the last-formed hydrothece. It generally appears as a
shining, solid rod, extending beyond the hydrothece. A number
of types with a single row of hydrothece also possess a virgula.
Types possessing this structure are classed in a division by them-
selves (Axonophora). In all cases the colony derived by budding
from a single sicula is called a rhabdosome, whether consisting of
one (single- or double-rowed) or many (single-rowed) branches.
In many cases a number of rhabdosomes may be united by the
ends of their virgule (that farthest away from the sicula), forming
a compound rhabdosome, which in some cases is provided with a
float or air-bladder-like structure, from the base of which also de-
pend the gonangia or reproductive sacs (Diplograptus). (Fig. 54.)
While some of the Gvaptolites were probably attached to sea-
weeds like modern hydroids, others were free-floating or plank-
tonic organisms. ‘This and the fact that sea weeds when torn from
their anchorage would also float, explains the wide distribution of
the Graptolites and their presence in rocks of the same age in
widely separated parts of the world. They are best preserved in
fine mud-rocks, especially the black shales. They have, however.
been found in limestones (calcilutytes) and even in sandstones,
They are excellent index fossils of the lower Palzeozoic rocks.

LITERATURE.

Some of the more important works on American Gvapiolites
are:

1865. Hall, James. Graptolites of the Quebec group. Canadian
Organic Remains Decade II., Geol. Surv. Canada.

1868. Hall, James. Introduction to the Study of the Graptolites.
N. Y. State Cab. Nat. History, zoth Ann. Report.

1879. Spencer, J. W. Graptolites of the Niagara Formation. Can.
Naturalist, 1878-79, p. 457.

1884. Spencer, J. W. Graptolites of the Upper Silurian System.
Mus. Univ. Missouri Bulletin.

GRAPTOLITES. 23

1892. Gurley, R. R. The Geologic Age of the Graptoiite Shales of
Arkansas. Ark. Geol. Surv. Ann. Rep., 1890, 3: p. 4o1.

1895. Matthew, G. F. Two New Cambrian Graptolites with Notes
on Other Species of Graptolitide of That Age. N. Y. Acad. Sci.
Trans., Aug., 1895.

1896. Gurley, R. R. North American Graptolites. Jour. Geol.,
Bie, 4, NO. 1,4 p. 633 NO. 2)-p. “291.

1904. Ruedemann, R. Graptolites of New York. Part 1. N. Y.
State Museum Memoir, 7.

[ This is the most comprehensive and most important work that has
appeared in this country since Hall’s Graptolites of the Quebec Group. ]

KEY TO THE GENERA.

I. DENDROIDEA. Rhabdosomes irregularly branching in a shrub-like funnel or fan-
like manner. Hydrothece mostly in the form of pits, rarely prominent.. 4.
manckes joined as frequent imtervals: <0... .<ecdaeseesveeseyecteas sivesseavsecess cos’ E.
1. Branches joined by cross-bars or dissepiments............... I. Dictyonema.

1. Branches flexuous, coalescing at points of contact ; dissepiments rare.
II. Desmograptus.
meiranches not joined, or only at great Intervals ....0.....6.sseccercaseoesasvesnosnne 2
BMRIEMARE ROR TAU COTS oC clon oo gs gua deve vawnaae ovale sasueweiueanvaaworaxaeebves aa.

aa. Branches stout, bifurcating, irregularly dendroid.

III. Dendrograptus.
aa. Branches plumose, with branchlets arranged alternately on oppo-

eG PCS ce niece cole vics vets; vipat ta cadue Paveh evden argue IV. Ptilograptus.

2. Branches parallel, bifurcating at intervals ..............ce.eeeeee Callograptus.

II. GRAPTOLOIDEA. Rhabdosomes simple or branching but not shrub-like.
seyerothéce commonly distinctly marked ..........2.cssecretareepsunesesesecons B.

B. AXONOLIPA. MEG PRES BD SORE Sou nts Gedvage ass sas daeiaaed dadmmas va eaeeae ay unehas Us .?

3. Branches with single row of hydrothecze (monoprionidian)............... bb,

66. Branches of rhabdosomes bifurcating at irregular intervals, nu-

NCTM. c-iy pamsa ny ss stock Poe ae ane CME DEEM aD re due aeie dosh psn rece Rk,

&. Branches apparently four at center, making a cross.
V. Staurograplus.

fea. SEARCHES EWG ADNCEIUBE So decider iin nds ax oascgsinaeselolenise Tey ek «deca H

x, Primary branches S-shaped................. VI. ions tiie:

x. Primary branches not S-shaped............c0.00008 Bryograptus.

6b. Branches of rhabdosome regularly bifurcating................0.seeeeeees L.
Gena be ORIEWVES ATtOre CHAM D fi525 cn byrne cietetis ws bain Sato Sch dee odin da vals Gupedevens y.

y. Three bifurcations (sometimes more) producing 16 branches.
VII. Loganograptus,

y. Numerous bifurcations, regularly alternating.
VII. Goniograptus.

fg AMC MR NER st geass sare ep yesss dk tesa geniy Heh vdistpans asp eki'savng Z
g. Branches $; sometimes 6..........0.0s00+0s VII. Dichograptus.
Br PSUMIICHES Aichdtee Faces s viveiscdb rast tndees css VIII. Zetragraptus.

Sie DIGRCNOS) 2. icncide GEV Mae aya upaatn cian nnids ae X. Didymograptus.

24 NORTH AMERICAN ‘INDEX FOSSILS.

3. Branches leaf-like, four rows of hydrothece, generally appearing as two

nows froma COMPRESSION 6. csh 5s iadcdens awxnsiadn ene atmos ek IX. Phyllograptus.

Pat ER ONOP GRA, — War SA TER EIUG a6: witht <cpntas tele oc xa Chill Sarge Wn abecigaese ake Ge apie aaa 4.

4. Branches with a single row of hydrothece or only partly with double row ce.

cc. Branches entirely distinct, only a single row of hydrothece (Mon-
oprionidian) opening in a direction opposite to the sicula.

XV. Monograptus.

te.. Two branches, more or lessiumitedty. .00 00.0. Saihaecs ds lee Fae
m, Branches united only at base, V-shaped with hydrothecz gen-
erally om Ogtsid@ ce ieee... vstsccaeioamuedes XIII. Dicellograptus.

m. Branches united for some distance, above the base, Y-shaped.
XII. Dicranograptus.
4. Branches with double row of hydrothecz throughout ( Diprionidian).. dd.

Gd PENGENNN SOMA... sj cndi ves vGeee peek aor cena ta ting eae an ante a ae n.
ms’ Thydrothees haters ois sea: stan we esac oes XIV. Diplograptus.
#.. Figarotiece:sblunt:.2923Piatacceeet. veeoeeaee XI. Climacograptus.
dd, . Pevidetun adinie mesh works 1.552.495. fo eeaien hace XVI. Retioltes.

SYNOPSIS OF GENERA AND SPECIES.

OrvbEeR I. DENDROIDEA Nicholson.

I. Dicryonema Hall.

Rhabdosomes forming funnel or fan-shaped fronds, composed of
numerous bifurcating branches arising from an acute base, and
united at intervals by thin cross bars

or dissepiments. Hydrothecz sel-

\ | | wy dom well preserved, of several types,
WW MA YLAZ, a i ionally as teeth or as
N\A WHT WV) ppearing occasionally
iE pits on the side of the branches
ANF WHY turned toward inside of the funnel.
A Wy Camb.—Dev.
AN Mey 1. D. flabelliforme (Eichwald). (Fig.
Sg 33.) Upper Cambie!
SY : Rapidly expanding cones up to
Sy ten or twelve inches in length.
NY

Branches about .4 mm. wide, sub-

parallel, rigid, bifurcating at long in-

FIG. 32. Dictyonema flabelliforme tervals, separated by a little over I

(after Matthew). mm. Dissepiments about half as

thick as the branches.

In the shales forming the uppermost Cambric beds of eastern

North America (especially in eastern Canada) and widely distrib-
uted in Europe.

GRAPTOLITES—DENDROIDEA. 25

2.°D, retiforme Hall. (Fig. 33.) Mid-Siluric.
Broadly funnel-shaped. Branches rather coarse, frequently bi-
furcating, marked pas by flexuous striz. Dissepiments

iS
Nt th ti i

———————
SSS:
=

===

——.—

i \
a

—

SS =>,
== SS

HN ay an Ui
j at Th Ny WL ip Nay i
ae : yy
BANU AA Meh Ae
NM VAN AN Mt Ki i Mit Pe
Nt ANA NH Aine i iat My Ol
ta Mt Nv wl \ ulin ‘li atest ll
SCN Wy int th tH ati
Menton tt hay “A NN + i Cin an tl i
SSN
a aa ESS ‘ es WY i) NE ‘a fe
|! (omteqens ie Ss ri bi a i
Wy acest th ma fe 4 ie inn rainy 4 q ‘

KN ma mi if xu aah ia ‘i
J andl ee eee am i AN xi HN i Nt SLUT nay my

ne ra tog Sy

1 isp wt

na w
ance Be
Fic. 33. Dictyonema retiforme (N. Y. State Mus. Rep.).

ayn

———r

thin, diameter about a fourth that of the branches; rather oblique
and numerous.
In the Rochester shale (Niagaran) of New York and Canada.

3. D. gracilis Hall. (Fig. 34.) Mid-Siluric,

“ny

a
TZ.

“dey,
'Y

&
pa.
=e wh},
oe SZ
a nee t:
~~ Ds
— iY ;

—~

|
—_
a

Fic, 34. Dictyonema gracilis (N. Y. State Mus. Rep.).

26 NORTH AMERICAN INDEX FOSSILS.

Branches very slender, bifurcating and slightly diverging, irreg-
ularly striated or indented. Dissepiments slender and distant.
Occurs with the preceding.

4. D. hamiltonia. Hall. (Fig. 35.) Mid-Devonic.

Fic. 35. Dictyonema hamiltonie with enlarge- Fic. 36. Desmograptus cancel
ment. Jatus (Ruedemann, N. Y. State
Mus. Mem.).

Branches slender, bifurcating, somewhat flexuous and uniting as
in Desmograpius. Dissepiments scattered. (This may belong to
the next genus.)

In the Hamilton shales of New York and in similar beds in
Michigan.

I]. Desmocrartus Hopkins.

Differs from Duzctyonema in the flexuous character of the
branches, which unite at intervals when they come in contact.
Dissepiments chiefly in lower part of frond. Ord.—Dev.

5. D. cancellatus Hopkins. (Fig. 36.) Lower Ordovicic.

Branches 12 to 14 in 10 mm. forming long narrow meshes,
twice as long as wide. ‘Thecal apertures circular.

In shales of the age of the Lower Chazy in New York and
Canada (?).

III. DeEnNDROGRAPTUS Hall.

Rhabdosome with a strong main stem supporting a broad,
spreading, shrub-like, variously ramifying frond. Hydrothecz
commonly obscure, or in the form of pits, sometimes well marked.
Ordovicic.

6. D. flexuosus Hall. (Fig. 37.) Lower Ordovicic.

An inch or more in length, branches broadly and rather regu-
larly diverging.

GRAPTOLITES—GRAPTOLITOIDEA. 37,

In shales of age of Beekmantown ( Zetragrapius zone) of Canada
and New York.
IV. PricoGcraptus Hall.

Rhabdosome with branches
provided with two rows of alter-
nate branchlets. No traces of
thecal apertures have been found.
Ord.-Sil.

7. Pt. plumosus Hall. (Fig.

38.) Lower Ordovicic.

Branchlets slender, filiform and

Fic. 37. Dendrograptus flexuosus (Rue- : : °

demann, N. Y. State Mus. Mem. ). close set, diverging at about 40°;
and about 3.5 mm. long.

In shales of the age of Lower Chazy, in Canada and New York.

N

ORDER II. GRAPTOLITOIDEA

Lapworth. \ |
Suborder Axonouipa Frech. 4 , |
V. StTauroGRraPptus Emmons. (Clonograp-
tus Hall.)
Rhabdosome cruciform at the center, ow- Q
ing to the rapid budding of the early hydro- \
thece. Repeated bifurcations produce a
large number of branches, hydrothece long
and but slightly overlapping. Camb.—Ord. /
8. S. dichotomus Emmons. (Fig. 39.)(C/o-

rapt O17 -
nograptus proxi SX Y

|/ < matus Matthew).
{2 Upper Cambric. Fic. 38. Ptylograptus
y Heagetien upward plumosus (Hall, Can. Org.
i i Rem. ).

of forty, the result
| : of repeated bifurcation. Thece from II
i S to 13 in IO mm., in contact for a little
/ MM | over a third of their length. Apertures
‘3 nearly vertical to axis.
eciroeraphus dicko- In the upper Cambric shales of eastern

femus (after Matthew). Canada and United States (Dictyonema
shales).

28 NORTH AMERICAN INDEX FOSSILS.

VI. CaznoGrartus Hall.

Bilaterally symmetric rhabdusome, the main stem (of tubular
hydrothece) bent into an S with simple unicellular branches of
similar structure given off from the convex
side. The sicula appears at the center of
the principal stem. Ordovicic.

g. C. gracilis Hall. (Fig. 40.)
Middle Ordovicic,

Slender stem, branches with fine serra-
tions from crowding of the hydrothece, Fic. 40. Cenograptus
Normanskill shales, Hudson Valley, etc. gracilis.

VII. Dicnocraptus Salter. (Including Loganograptus
and Gontograptus.)
Rhabdosome of eight (typical) or more (Loganograptus and
Goniograptus) large and narrow branches, united by a common

Se AS STUY, stem in center which with the lobes

of the branches lies within a central

—————s SSS membranaceous' disc. Branches

with single row of hydrothecz, be-

SSS coming prominent some distance

from center. When branches occur
Fic. 41. a (upper), Loganograptus
logani,; 6 (middle left), Zeragraptus separated, they can only be deter-
quadribrachiatus; c, Dichograptus mined by the form of their hydro-
octobrachiatus ; @ (lower), Gonto- thece. Ordovicic.

graptus thureaui (all enlarged).
10. D. octobrachiatus Hall. (Fig.
Ar) Lowest Ordovicic.
Eight, large and coarse branches often a foot long — central
disk eight-angled.
Lower shales, Point Levis and Hudson River Valley, Beekman-
town horizon. Also European.

11. D. (Loganograptus) logani Hall. (Fig. 41, a.) Lowest

Ordovicic. |

Numerous (thirteen to twenty-five, normally sixteen) slender
branches up to nine inches long, symmetrically branching at base.
Hydrothecze become prominent only at some distance from base.
Central disk many-angled.

Lower graptolite shales (Beekmantown), Point Levis and Hud-
son River Valley. Also European.

GRAPTOLITES—GRAPTOLITOIDEA. 29

12. D. (Goniograptus) thureaui McCoy. (Fig. 41,d, 42.) Lower

Ordovicic.

Four nearly rectangular main branches of a zigzag outline with
regularly alternating secondary branches.

Lower graptolite shales of
Quebec and Hudson Valley
(Beekmantown), Also Euro-
pean.

ef VIII. TretrraGraptus Salter.

Typically of four short and
broad branches with large hy-
drothece. A common trans-
verse stem (funicle) occurs. A
croup still classed here is like a
Dichograptus with only four
arms, and a quadrangular cen-
tral disk. It really belongs to
a distinct genus. Ordovicic.

i

FIG. 42. Goniograptus thureaut.

13. T. bigsbyi Hall. (Fig. 43.) Lower Ordovicic.
Of four short broad arms, with narrow but long hydrothece
mucronate at the margin. Strong central stem.
Lowest graptolite beds (Beekmantown) of

Point Levis and Hudson Valley.

14. T. quadribrachiatus (Hall). (Fig. 41,
Are Lower Ordovicic.
Like half a Dichograptus octobrachtatus —

long slender branches with small hydrothece

and a quadrate central disk.
Lower graptolite beds (Beekmantown) of Canada and Hudson

Valley. Also Europe.

Fic. 43. TZetragraptus
bigsbyt.

IX. Puytiocrartus Hall. —

Like Zetragrapius with the four branches grown together, each
two back to back, forming a cross in section — generally preserved
in flattened form so as to appear as a single leaf-like body. Or-
dovicic.

15. P. typus Hall. (Fig. 44.) Lower Ordovicic.
Broad, oval to lanceolate, as appearing on shale, with 24 (22-26)

30 NORTH AMERICAN INDEX FOSSILS.

hydrothece to an inch. Broad axis or midrib, often crenulate or
serrate.

Lower graptolite shale (Meper Beekmantown) Canada and Hud-
son Valley.

16. P. ilicifolius Hall. (Fig. 45.) Lower Ordovicic.
b
a
Fic. 44. Phyllograp- Fic. 45. Phyllograptus itlictfolius. a, natural size;
tus typus (after Roemer), 46, enlarged; and ¢, restored crosssection (after Roe-

enlarged. mer).

Differs from the preceding in its thicker substance, proportion-
ally shorter and broader form, more closely arranged hydrothecze
(29-32 to an inch) and strongly mucronate or spinous lower lip of
hydrothece.

Shales of Middle Beekmantown age, Canada and New York.

17. P. angustifolius Hall. (Fig. 46.)
Lower Ordovicic.
Narrow elongate form, generally a little
broader at the base. Thecze strongly mu-
cronate on lower sides. Lower shales (Beek-
mantown) of Point Levis and Hudson Valley.

:
7
V

a

Fic. 46. Phyllograplus
angustifolius, enlarged
(after Roemer).

16, 2s apnavliall.” Lower Ordovicic.

More nearly rounded, often truncated, nu-
merous thece. Higher Beekmantown and
Lower Chazy horizon.

a

X. Dipymocraptus McCoy.

Rhabdosome consisting of two symmetrical
branches diverging from the basal cell (sicula) at angles from 10°
to 180° or over, with oblique hydrothecz opening inwards. Or-
dovicic.

GRAPTOLITES—GRAPTOLITOIDEA. 31

19. D. bifidus Hall. (Fig. 47, ¢, 48.) Lower Ordovicic.
Divergence of branches 15° to 20°, gradually widening through
increase in length of hydrothecz to about two thirds distance from

Fic, 47. @ (upper), Didymograptus nitidus; 6, D. Fic. 48. Didymogaptus
patulus ; c (lower), D. bifdus (all enlarged). bifidus.

base, then narrowing again to apex. Shales of upper Beekman-

town age (Deep Kill), Point Levis and Hudson Valley.

20. D. nitidus Hall. (Fig. 47, a, 49, 2.) Lower Ordovicic.
Thece closely arranged, margin slightly concave, rectangular to

axis of theca. Branches with wide angle of divergence (nearly or

quite 180°). Lower Ordovicic of Point Levis and Hudson Valley

(Beekmantown).

21. D. patulus (Hall). (Fig. 47, 4, 49, 2.) Lower Ordovicic.
—————E

Cd

Fic. 49. @ (upper), Didymograptus nitidus; 6, Didymograptus patulus.

Differs from LD. xztzdus in its wider and more rapidly widening
branches, with ends of hydrothecz concave and strongly acute in-
stead of rectangular.

Lower graptolite shales (Beekmantown) of Point Levis and
Hudson Valley.

Suborder AXONOPHORA Frech.

XI. CrimacoGraptus Hall.

Simple rhabdosomes, with parallel hydrothece, their outer
margin straight and parallel to the axis of the stem. Ordovicic.

32 NORTH AMERICAN INDEX FOSSILS.

22). picornis. | (Fig. 50; .5.1,,,a:) Middle Ordovicic.

Gradually widening upwards, hydrothece approaching rectangu-
lar outline, base with two diverging mucronate points.

Normanskill shales (Trenton) of Hudson
Valley, and equivalent beds of the Cincinnati
region.
23; C..typieussiiall.” (Fig. 5 1,0.)

Upper Ordovicic.

Differs from preceding in narrow almost
horizontal incisions between, and small mucro-
nate point at base of hydrothece.

Utica Slate of New York and Cincinnati re-
gion.

XII. DicranoGraptus Hall.

Lower portion of hydrosome biserial, upper
portion dividing into two uniserial branches.

Form Y-shaped. Hydrothecze as in Ch-
macograpius. Ordovicic.

Fic. 50. Climacog-
raptus bicornis (slightly
enlarged).

24. D. ramosus Hall. (Fig. 52.) Middle Ordovicic.
Undivided portion long, incisions between
hydrothece deep, the latter with mucronate
points.
Normanskill shales (Trenton), Hudson Val-
ley. Europe. |

Fic. §1) a; (left), "XII. Dickttocrartus Hopkins.

rraptus bicornis ; : 4 =
dei us bicornis Fikouie racsesaniee But divided to cnet
b, C. typicus (enlarged). =
V shaped. Ordovicic.

25. D. complanatus Lapworth. (Fig. 53, @, 2.)

Middle Ordovicic.

Diverging at angle of 30-50 degrees. Hy-

drothece narrow and very oblique; non-
mucronate.

Normanskill shales (Trenton), Hudson Val-

ley.
26. D. divaricatus Hall. (Fig. Sey) si, ric. «2
Middle Ordovicic raptus ramosus (slightly
Diverging at angle of over 90°, up to 130°; enlarged).

GRAPTOLITES—GRAPTOLITOIDEA. 33

hydrothece furnished with slightly incurved hook-like projections
on the upper outer region; 3 basal spines.
Normanskill shales (Trenton), Fiudson Valley.

27. D. sextans Hall. (Fig. 53,d, ¢.) Middle Ordovicic.

z

a
Fic. 53. a, Dicellograptus complanatus ; 6, same, enlarged ; ¢, D. divaricatus (en-
larged) ; ad, D. sextans; e, same enlarged.

Similar to preceding, but basal spines turned up and outward.
Normanskill shales (Trenton), Hudson Valley.

XIV. DirpLtocraptus McCoy.

Rhabdosomes linear to leaf-like, with two rows of alternating
oblique hydrothece. Virgula prolonged beyond the proximal end
and in perfect colonies attached with others to a floating (?) central
disk. Ordovicic.

28. D. pristis Hisinger. (Fig. 54.) Upper Ordovicic.
Large oblique, acute serrations,
pointed exteriorly, three basal
spines, the central one usually
longest.
Utica slate of New York and
other states and Canada. Europe.

29. D. foliaceus Murchison.

Fie. 54. Diplograptus pristis. Res- Middle and Upper Ordovicic.
toration of colony by Ruedemann. 72, }
pneumatophore or swimming bladder ; Hydrothece more oblique,
g, gonangia (N. Y. St. Geol. Rept.). | Smaller and more numerous than

D. pristis.
Normanskill shales (Trenton), Hudson Valley. Europe.

3

34 NORTH AMERICAN INDEX FOSSILS,

30. D. whitfieldi Hall. Middle Ordovicic.
| Like D. prestis, but hydrothece with spinose prolongations, and
base with a single spine.

Normanskill shales (Trenton) of Hudson Valley.

31. D. dentatus Brongniart. (= D. pristiniformis Hall.)
Lower Ordovicic.
Narrow slender stipes with closely crowded, very oblique hydro-
thece.
Graptolite shales of Point Levis and Hudson Valley. Lower
Chazy. Europe.

XV. Monocraptus Geinitz.
Rhabdosomes with only a single row of hydrothece, which in
the American form are drawn out into bent points, at the apices of
which are the openings. Silur.—Dev.

32. M. clintonensis Hall. (Fig. 55, 2.) Middle Siluric.

Stipes straight with well-marked virgula. Ends of hydrothece
bent over so that apertures open downward.
Clinton shales of Rochester,N.Y.

.
RH eee Ay
SNORT ATA

XVI. ReEtTIOLITES Barrande.

Rhabdosome with the periderm attenu-
ated and supported on a meshwork of
fibers. Hydrothece in two rows, opening Fic. 55. a (left), Retiolites
outward. Two virgule attached to oppo- venosus; 6, Monograptus
site sides, in the median plane. Ord.—Sil. ©”427¢s7s (both enlarged).

33. R. venosus Hall. (Fig. 55, 2.) Mid-Siluric.
Hydrothece slightly oblique; apertural margin concave; peri-
derm very tenuous. |
In the Clinton shales of western New York, associated with the
preceding.
Hydrocorallines.
STROMATOPOROIDEA Nicholson and Murie.

The Stromatoporoids are extinct organisms practically confined
to the Paleozoic, where they were extremely important reef-builders,
much of the limestone of the Siluric and Devonic resulting from
the destruction of reefs of these fossils. They are most closely re-
lated to the modern Hydrocorallines (Millepora) and to Hydrac-

HYDROCORALLINES. 35

tinia, an aberrant type of Hydroid. This latter will serve to
elucidate the structure of the Stromatoporoids.

Hydractinia (Fig. 56) commonly grows as an incrustation on the
shells of dead gastropods, which have been seized as a habitation
by hermit crabs. It is also found, how-
ever, encrusting rocks. The polyps are
naked, z. ¢., not protected by hydrothe-
cz, and of several kinds. The ordinary
feeding polyp or nutritive zooid has a
mouth and tentacles. A second type of
polyps has short, club-shaped tentacles
and bears a cluster of reproductive buds
or gonangia. These are the gonopolyps.
A third and sometimes a fourth order of

Fic. 56. Aydractinia (Re- polyps occur, scattered about or confined
cent), showing 3 types of polyps to certain regions. These have an offens-
ee hydrophy- ive and defensive function and apparently

warn the colony of approach of danger.

The colony secretes a basal horny or calcareous structure, the
hydrophyton, which consists of successive, slightly separated, hori-
zontal laminz, supported by numerous vertical columns known as
vadial pillars (Fig. 57). From the surface
arise hollow spines and tubercles, which
serve as a protection when the polyps are con-
tracted below their summits. The spaces be-
tween the lamine communicate with the sur- 5, wis wid achase:
face by mieans of tubes, and branching Cross-section of hydrophy-
grooves or astrorhiz@ are commonly present ton through a spine, show-
on the surface. In JJillepora the colony se- 18 horizontal laminz and
cretes a calcareous structure (cw@nosteum) not nar sacs
unlike some coral masses. This consists of a network of calcare-
ous fibers and is traversed at frequent intervals by large tubes sur-
rounded by a ring of smaller ones. The larger tubes (gastropores)
lodge feeding polyps, and the smaller (dactylopores) lodge fighting
polyps. Both sets of tubes are divided in the older part by hori-
zontal partitions or tabule.

The extinct Stromatoporoids combine the characteristics of the
two types outlined above. They consist of hemispherical, spread-
ing, encrusting, columnar, or nearly globular calcareous structures
sometimes attaining a diameter of five feet or over, or a length of

36 NORTH AMERICAN INDEX FOSSILS.

ten feet (Leaticea). The base is generally covered by a con-
centrically wrinkled calcareous crust or efztheca. In structure
these bodies recall the hydrophyton of Aydractinia as described
above, consisting of numerous concentric undulating calcareous
lamine, separated by interspaces, and supported by radial pillars.
Both lamine and supporting pillars are traversed in most cases by
minute canals, and in some types vertical “zooidal tubes” with
tabule occur, as in J/%llepora. The surfaces of the laminz are
marked by numerous pores, the openings of canals, and by
tubercles, blunt rounded prominences or “ mamelons,” or blunt
spines, and shallow furrows radiating from a center (As¢rorhiz@).
In some types (Actinostroma) the laminz are composed of a net-
work of calcareous rods disposed in a horizontal series. In some
cases the horizontal and vertical elements are so fused as to form
a dense reticulated tissue, when the separate components are with
difficulty distinguishable (Szromatopora). Frequently the hori-
zontal laminz are combined into strata or “latilamine” of some
thickness, separated from each other by a slight interspace.
Several species of Stromatoporoids encrust cylindrical corals
(Aulopora, Syringopora, Ceratopora, etc.) which become com-
pletely immersed in the Stromatoporoid, opening only on the sur-
face in circular orifices. These orifices were formerly thought to
be a structural part of the Stromatoporoid and the name Cauno-
pora was applied to these types. Similar commensalism occurs in
some Bryozoa.
LITERATURE.
1866. Winchell, Alexander. On the structure and affinities of the
Stromatoporoids. Proc. Amer. Assoc. Adv. Science, 1866, p. 91.
1873. Hall, James, and Whitfield, R. P. Description of new
species of fossils. 23d Ann. Report N. Y. State Cabinet, pp. 226-228,
pl. 9. }
1874. Nicholson, H. A. Paleontology of the Province of Ontario.
1875. Paleontology of Ohio, Vol. II.
1878. Nicholson & Murie. The minute structure of the skeleton of
Stromatopora and its allies. Journ. Linn. Soc., Vol. 14.
1878. Quenstedt. Petrefacten Kunde Deutschlands. Schwamme,
pl. 141 and 142.
1884. Spencer, J. W. Stromatopoids. Bull. Mus. University of
State of Missouri, 1, 43-52.
1886. Nicholson, H. A. On somenew or imperfectly described spe-
cies of Stromatoporoids, Ann. and Mag. of Nat. Hist., Ser. 5, Vol.
17, p.225 3-Vol.. 18, p. 8, Vol. 19, Pp...

HYDROCORALLINES—STROMATOPOROIDEA. 37

Foor:..“same, part [V., do , Ser, 6; Vol. 7, p. 360.

1886-92. Nicholson, H. A. A monograph of the British Stromato-
poroids. Palzontographical Society monograph.

1894. Girty, G. H. Revision of thesponges and ccelenterates of the
Lower Helderberg Group of New York. 14th Ann. Rept. N. Y. State
Geol., p. 289, Stromatoporoidea.

Two keys are herewith given. The first is based on the micro-
- scopic structure and requires thin sections. It is believed that by
its means most species may be traced to their proper genus.
The other is based on external characters and is given to make
possible field determination of the more important species of
«“Stromatopora”’ in the old sense. It applies only to the species
described.

I. KEY TO THE GENERA.*

A. Calcareous tissue a meshwork of horizontal and vertical rectangular elements..... yes
I, Structure an open meshwork, radial pillars distinct, horizontal laminze of cal-
Ares SM SEOMIGS DOTS Oo oa: nase aWiat ogi soabivanbee slave vaewh¥eneieanne
*, Radial pillars continuous through a number of laminz and interlaminar
EOC cae avid teense rar save cuyeng tae ise saescasiRoebysuvigapese I. Actinostroma.
peeaceatial Dillars’ CISCOMUNUOUS - 2... 002... sca-ceereacs vovseonnr II. Clathrodictyon.
I. Structure an open meshwork, radial pillars very large, horizontal elements thin
OR ORES oe eae sole cam annie rua Pcie bea aglaw weaeiaee Ha va gN oer as VII. Ladechia.
I. Structure a dense reticulate meshwork in tangential section, but more open in
vertical section, the radial pillars distinguishable..................eeeeeees ,
** Worm spherical, massive or expanding ........... ...-00«. kN aerate tance’ aa.
aa. Lamine bending upwards at regular intervals, forming a series of
vertical rod-like structures passing through the mass.

, IIL. Stylodictyon.

aa. Laminz not bending upwards, short irregular zodidal tubes.
IV. Stromatoporella.
** Form cylindrical and commonly branching, numerous well developed tab-

ulate zodidal tubes opening by circular pores .............. V. Ldiostroma.
I. Structure a dense reticulate meshwork in both tangential and vertical sections,
SIactel pillars Generally NOt CISUNCE ooo i... ceanncctesssenrons dwedieterdevese me

*** Structure reticulate, tabulate zodidal tubes well developed.
VI. Stromatopora,
*** Structure very dense, but vertical and horizontal elements distinguishable.
3 : VI. Syringostroma under Stromatopora.

8. Calcareous tissue of concentric laminz, no vertical pillars..... ......:.cseesecee eens Ad:
SEPERE WETUICAL CHDES... |... iocie-lcoutecnseseanseseseotonsenses VII. Stromatocerium.
BME TEDOUL VETUICA] CODES... 6. cecccasasecss sueveenscrsensesersrridnees VIII. Cryptozodn.
C. Calcareous tissue a single layer covered with a basal epitheca and with numerous
teem tabercles.on the surface...........5,0cceccccossceesescace, IX. Labechia (young).
D. Calcareous tissue a series of vesicles, form columnar ..............sese0. X. Beatricea.

* Based on microscopic structure.

38 NORTH AMERICAN INDEX FOSSILS.

II. KEY TO THE SPECIES OF ‘‘STROMATOPORA’’ IN THE OLD SENSE BASED
CHIEFLY ON EXTERNAL CHARACTERS.*

A. Form a flattened or undulating expansion, generally with a basal epitheca........ Ee
2 Preaar only attached at intial Pont. <. tac, schncsesnaceetes cacy sepereeatbelecnap aioe a.

ny DUTIREE WAL MANAG] ONS 2g on ara. egnns veoh crak dedinndday dude wheniane poe een vena aa.

aa, Mamelons prominent ; astrorhize present though inconspicuous, sur-

FACE DIAUWIALE. . « Sanisncinnaclanbeneenki nae combats g. S. granulata Dev.

aa. Mamelons low, astrorhizz absent ...............- I. S. expansa Dev.

a. Surface sometimes undulated, with tubercles instead of mamelons ; no astro-

FIUZORS jis: siaiditionee eehdn's Sheath ease MAe eatLS. <aperheieciaeee marae aided bo.

66. Tubercles of two sizes, the larger with pores. 10. S. ¢uberculata Dev.
6. Tubercles minute, in rows, with pores between rows.

5. 5. striatella Sil.
66. Tubercles scattered, meshwork very coarse....... 7. S. cellulosa Dev.

a. Surface without mamelons or tubercles......... cee: ss\a6-0.d.aakidnieiaiog a Ree cc
ec. Astrorhize: well developed ssc. <sscispantivevncen cane 2. S. fenestrata Dev,
C6) USIP OHIIZ2S SING) dos nae sic ceewoh fa pubs sienseete ete: 4. S. vesiculosa Sil.

* Encrusting other fossils. Tubercles instead of mamelons ; astrorhizz present.
II. S. zxcrustans Dev.

B. Form massive, hemispheric or spherical..............0..00+« pee er -.
** Divided into strata or latilamine.,...............+ sieges Ribena ae siamiee + scien b.

6, Surface with Mamelons . ..<.5:0004. 00a snse anne cue Mie dave as es nce shines tose ce

cc. Astrorhize well developed.......... scsssenes 14. S. monitculifera Dew.

ec. Astrorhiza: small. iii 5525 ..5- ee is divans sieving Vtaiteip Nem tas pe veeeon ae

1. Mamelons sharp and conical.................6- 3. S. nodulata Dev.

1. Mamelons low and rounded ; astrorhize minute.
17. S. centrota Lower Dev.

&. Surface with pustules instead of mamelons.............:<2-s0s«0-seceessdeeee dd.
dd. -Aatrorhiges sttiall ncc:5nisumeudes (a> meds ssasene 15. 5. Pustalifere Dew.

6, Surface without mamelons or pustules, ......0..0sss0c00<¢s'e<se0nseneenle ee ee.
2é;; AStEOPDIZE DECSEDE oc. cesabisetcun aa esas rasbiyacabanededwis dobagee esa

2. Vertical section shows only dense tissue ...... 16. S. densa Dev.

2. Vertical section shows minute tabulate tubes traversing the entire

SEPMEMINE LS aaciav ons denies vomeeees snare casetegseea ante 13. S. antigua Sil.

é¢,, Astrorhiza absent <i0a.0.05c00% EE LCN . 18. S. darretti Lower Dev.

** Not divided into strata, or but imperfectly so....... siti in i qalngat co oe 7apeeen cen a
c. Surface without true mamelons................05+ scbisiegt vata any orn aa F-
offs | ASUOMIN ZS GDSEI ssa fan cadaine pg tere a ueren us cnbeionssinaansduiseanavay eae mee

3. Surface finely granulated with pores between rows of granules.
5. S. striatella Sil.
3. Surface with pustules, formed by the ends of large vertical rods.
8. S. columnaris Dev.
3. Surface with pustules in regular diagonal lines, and large irreg-

ular nipple-like elevattons ..i<..<s.se0ssunoness 6. S. ostiolata Sil.

c. Surface with conical mamelons, astrorhize small,..... 3. S. zodudata Dev.

C. Form cylindrical or branching .............. ievakaas eas Kona amsnimvne nine edad meee Pi
*** Surface with prominent pointed tubercles .............cs0000sseesese Pere d.

d. Branches with rounded ends, surface porous ......... 12. S. cespitosa Dev.

* This is adapted only to the species here described. It does not include Stromato-
cerium, Cryptozoén, Labechia or Beatricea. Endings become feminine.

HYDROCORALLINES—STROMATOPOROIDEA. 39

SYNOPSIS OF GENERA AND SPECIES.

I. ACTINOSTROMA Nicholson.

Laminz consisting of a meshwork of fibers. Radial pillars more
or less continuous throughout, subequally spaced and generally

Fic. 59. <Adctinostroma fenestratum..

Fic. 58. Actinostroma expansum, sur- Vertical section x oa (After Nicholson. )

face. (N. Y. State Cab. Rep.)
projecting on the surface in the form of granules or tubercles. In

vertical section the pillars and laminz form a more or less regular

series of rectangular meshes. Astrorhize present or absent. Siluric
(rare)—Dev.

1. A. expansum (Hall & Whitfield). (Fig. 58.) Devonic.
Large expanding masses sometimes many feet in diameter,

Fic. 60. Actinostroma nodulatum with horizontal and vertical sections. (Nichol-
son, Pal., Ohio. )

slightly undulating surface with low broad mamelons, three eighths
to one half inch from center to center. Astrorhize absent.
In Upper Devonic rocks of Iowa and Canada.

40 WORTH AMERICAN INDEX FOSSILS.

2. A. fenestratum Nicholson. (Fig. 59.) Devonic.
Skeleton fibers coarser than preceding species — surface without
the prominences (mamelons); astrorhize well developed.
In Devonic limestones of Manitoba, etc. Also European.

3. A. nodulatum (Nicholson). (Fig. 60.) Devonic.
In large expanding masses, with large sharp conical mamelons
12 mm. apart and small astrorhize.
Onondaga of Ohio.

II. CratHropictyon Nicholson.
Laminz a meshwork similar to preceding genus. Kadial pillars
discontinuous, extending only from lamina to lamina. Astrorhizz

Fic. 61. a, Clathrodictyon vesiculosum, X 8; 6, Clathrodictyon striatellum, * 8;
¢, Stromatoporella granulata, X 8. (All vertical sections. )

present. Vertical section often appearing vesiculose. Siluric
(common)- Devonic (rare).

4. C. vesiculosum Nicholson & Murie. (Fig. 61, a, 62, 63.)
Siluric. ;
Laminar expansions covered by a concentric basal epitheca;

adult half a foot or more in diameter by an inch or more in great-

est thickness. No rounded
prominences; small astrorhizze

with centers from 3 to 5 mm.

apart. Nine to eleven lam nz

to.I mm.

In the Clinton and Niagara of

Ohio, Canada, New York and

Anticosti. Also European.

Fic. 62. Clathrodictyon vesiculosum, xX

Be C. striatellum d’Orbigny. 60. (After Nicholson. )

(tic, 61,0) Siluric.
Laminar or hemispheric with concentrically wrinkled epitheca.
Surface undulating but no “ mamelons,’ generally exfoliating con-

HYDROCORALLINES—STROMATOPOROIDEA. 4I1

centrically around elevated areas. Numerous minute rounded
tubercles, alternating with minute pores on well preserved surfaces.
No astrorhize. Coarse (5 lamine to I mm.) radial pillars like
spines growing downward from bot-
tom of lamine.

This is, according to Nicholson
and Hinde, the common species of
the Niagara of Canada, usually re-
ferred to as Stromatopora concen-
t‘vica.

6. C. ostiolatum Nicholson. Siluric.
Differs from the preceding in the

presence of nipple-like elevations of

the entire mass at intervals, and in

the occurrence of small perforated

tubercles at regular intervals in diagonal lines. |
In the Guelph of Canada and New York.

Fic. 63. Clathrodictyon vesiculo-
sum under or epithecal portion.

7. C. cellulosum Nicholson & Murie. (Fig. 64.) Devonic.
Differs from C. vesiculosum in the coarser meshwork (about 2
lamine to I mm.) and in having the surface covered with tubercles
or granules; and from C. stviatellum in the
coarser meshwork.
Onondaga limestone of Canada, New
York, etc. .

III. Stytopicryon Nicholson & Murie.

Coenosteum a dense tissue traversed by
numerous closely set circular vertical col-
umns of large size, formed by the upward
bending of the concentric laminae. They
terminate on the surface in small pointed
eminences. Between the columns the tis-
sue is more open, consisting of horizontal
lamine and vertical (radial) pillars, the

latter often imperfect. Devonic. Fic. 64. Clathrodictyon
8. S. columnare Nicholson. (S.wortheni sosum. (After Nichol-
4 . son.
Quenstedt.) (Fig. 65.) Devonic.

A large mass readily recognized by the vertical rods of dense
tissue formed by the upward bending of the lamine, and the small

42 NORTH AMERICAN INDEX FOSSILS.

rounded knobs in which the rods terminate on the surface, these
being separated by a little more than half their diameter. Middle
Devonic limestones of Ohio and Michigan (Traverse group).

a

VEL

% ~

Fic. 65. Stylodictyon columnare with enlarged vertical section ( Nicholson, Pal. Ohio),

IV. STROMATOPORELLA Nicholson.

Coralline mostly a lamillar expansion, furnished with a basal
epitheca. Latilaminze imperfect or not developed. In vertical
section concentric lamelle and radial pil-
lars distinguishable. In tangential sections
the ends of the pillars are distinguishable,
while the general character of the tissue is
reticulate; short irregular zooidal tubes
present. Devonic.

g. S. granulata Nicholson. (Fig. 61, c,
66.) Mid-Devonic. Za
Laps

J Fic. 66. Stromatoporella
=~ erases granulata enlarged vertical
Fic. 67. Stromatoporella tuberculata (after Nichol- section.

son).

Laminar expansions with concentrically wrinkled and striated
epitheca. Thickness from 2 mm. up to 2 or 3cm. Rather dis-

HYDROCORALLINES—STROMATOPOROIDEA. 43

tant rounded mamelons pierced by apical pores, and with astro-
rhize inconspicuous. Surface covered with granules.
Common in the Hamilton formation of Canada.

10. S. tuberculata Nicholson & Murie. (Fig. 67, 68.)
Mid-Devonic.
Differs from the preceding in absence of mamelons, the surface
being undulating and covered only with tubercles of two sizes, and
in coarser meshwork (about 6 lamine to 2 mm.).

Fic. 68. Stromatoporella tuberculatayen- FIG. 69. Stromatoporella incrustans
larged surfaceand section(after Nicholson). (N. Y. State Mus. Rep.).

In the Onondaga limestone of Canada and New York.

11. S. incrustans Hall & Whitfield. (Fig. 69.) Devonic.
Encrusting other fossils. Astrorhizz with central tubercles
pierced by pore.
Upper Devonic of Iowa and elsewhere.

V. Ipiostroma Winchell.
Form typically cylindrical, branching or growing in fascicles.
_ Each branch has generally a tabulate tube, while other smaller tab-
ulate zooidal tubes with rounded openings are abundant. Radial
pillars and concentric laminz distinct. Surface with prominent
pointed tubercles often arranged in ridges, or nearly smooth. De-
vonic.

12. I. cespitosum Winchell. Mid-Devonic.
Branching irregularly ; branches club-shaped.
Abundant in the limestones of the Traverse group (Hamilton) in
Michigan.

44 NORTH AMERICAN INDEX FOSSILS.

VI. SrrRoMATOoPORA Goldfuss.

Massive or laminar. Laminz grouped in strata or “latilamine”’;
radial pillars numerous, extending across a stratum and uniting with
the laminz to form a finely retic-
ulated tissue as seen in vertical
section. Tabulate zoodidal tubes,
and astrorhize present. Syring-
ostrvoma differs chiefly in its denser
structure and somewhat more dis-
tinct horizontal and vertical ele-
“ments. Silur. (rare)-Devonic.

13. S. antiqua Nicholson & Murie.
(Pig.-70.) Siluric.
Massive, spheroidal or hemis-

pheric, with well-marked strata or

latilamine 5 or6toIcm. Delicate
zooidal tubes traversing entire

stratum. Astrorhizal centers 4-5

mm. apart, mamelons absent.
Niagara limestone of Canada

and New York.

14. S. (Ceenostroma) monticuli-
fera Winchell. Devonic.
In large hemispheric or globu- Fic. 70. Stromatopora antigua, ver-

lar masses, surface with large ma- tical sections, the lower, 2 (after

; ; Nicholson).

melons and astrorhize; centers ~~

7-6 to 10 mm. apart. Extremely abundant in the Traverse (Ham-

ilton) group of Michigan. |

15. S. pustulifera Winchell. Devonic.
Similar to preceding, but surface with pustules instead of mame-
lons and smaller astrorhizal centers, 4 mm. apart.
Occurs with the preceding.

16. S. (Syringostroma) densa Nicholson. (Fig. 71.) Mid-
Devonic.
Surface without mammille but well developed astrorhize.
Structure exceedingly dense.
Onondaga of Ohio and probably eisewhere.

HYDROCORALLINES—STROMATOPOROIDEA. = 45

Fic. 71. Syringostroma densum with horizontal and vertical sections, enlarged

(Nicholson, Pal. Ohio).

17. S. (Syringostroma) centrota Girty. (Fig. 72, a, upper sec-
tions.) Lower Devonic.
Spheroidal, surface with rounded mamelons and minute astro-

rhize. |

Lower Helderberg of New York.

18. S. (Syringostroma) barretti Girty. (Fig. 72, 4, lower sec-
tions.) Lower Devonic.
Hemispheric with flat base, surface without mamelons or astro-

rhize. Laminze flexed in wave-like manner.
Lower Helderberg of New York.

Fic. 72. @ (upper two), Syringostroma centrotum, tangential and vertical sections ;
6 (lower two), Syringostroma barrétti, tangential and vertical sections (Girty in N.
Y. State Mus, Report), enlarged Io.

46 NORTH AMERICAN INDEX FOSSILS.

VII. Stromatoccarium Hall.

Coenosteum massive, of dense, thick horizontal and concentric
discontinuous lamine, separated by very narrow interspaces. No
radial pillars. Small vertical tubes penetrate the several lamina,
connecting interlaminar spaces. No astrorhize. Ordovicic.

19. S. rugosumHall. Middle Ordovicic.
Hemispheric, with wrinkled concentric laminz, and faint indica-
tions of vertical tubes.
Black River limestone, New York, Canada, etc.

20. S. eatoni Seely. Lower Ordovicic.
Expanding masses two inches or more in thickness, surface with
mamelons. On weathered surfaces numerous concentric rings
appear around the mameions.
Chazy of Lake Champlain.

VIII. Cryptozoon Hall.

Coenosteum of irregular concentric lamine, traversed by minute
canals which branch and anastomose irregularly. No astrorhize.
Camb.—Ord.

21. C. proliferum Hall. Lower Ordovicic.
Grows in compressed spherical cakes a foot or more in diameter.
In the Beekmantown horizon of New York, etc.

IX. Lapecuia E. & H.

Expanded, with a basal epitheca, vertical pillars a series of blunt
tubercles in the young form, connected in adult by thin calcareous
plates. Differs from Actnostroma in the large
size of the pillars which are connected by
plates instead of fibers. Ord.

22. L. ohioensis Nicholson. (Fig. 73.)
Ordovicic.
Laminar or encrusting. Surface often with
mamelons and with minute tubercles. Ra-
dial pillars distant, interspaces vesicular.
Upper Cincinnati beds of Ohio, Indiana, Canada, etc.

Fic. 73. Labechia ohio-
ensis, X 9.

X. Beatricea Billings.

Cylindrical or angulated stems, often fluted and ranging in size
to over ten feet in length and a foot in diameter. A central tube

STROMATOPOROIDEA—ANTHOZOA. 47

with cystose tabulz and a peripheral vesicular structure character-
ize the fossil. Ordovicic.

23. B. nodulosa Bill. (Fig. 74.) Ordovicic.
Cylindrical, with oblong, oval or subtrian-
gular blunt-pointed tubercles, sometimes ar-
ranged in vertical rows.
Trenton and Cincinnati groups Anticosti
and Kentucky.

24. B. undulata Bill. Ordovicic.
Surface sulcated longitudinally by short,
dulosa, transverse section . a :
ne? irregular, wave-like furrows, from two lines to
showing inner tube and 7 , ;
cystose character (after One inch across, according to size of specimen.
Nicholson). Cincinnati group of Anticosti.

Fic. 74. Seatricea no-

Class Anthozoa or Actinozoa (Corals).

‘Marine animals ranging from low water to depths of 1,500
fathoms, but chiefly at home in tropic seas above the fifty fathom
line. The animal or polyp may be simple, or give rise by budding
or division to a compound polyparium, in which the individuals
or polypites may be distinct or confluent.

The corallum or hard structure secreted by these animals is
simple or compound. Typically each coral is furnished with a cir-
cumferential wall, and radiating lamelle or sepéa, though either
the one or the other may be much reduced or even absent. The
wall may be an independent structure, growing up like the septa
from the bottom of the corallum (theca), or it may be formed of
the thickened and fused outer ends of the septa (pseudotheca).
The outer ends of the septa are frequently continued beyond the
wall as cost@. Often an outer more or less wrinkled envelope or
epitheca occurs, which shows concentric lines of growth. Between
the septa are various endothecal structures, such as cross plates or
dissepiments, cross-bars or synaplicule, or continuous floors or
tabule which extend across the whole coral. In some cases the
interior consists of a spongy mass, the septa being very rudimen-
tary (Cystiphyllum). The septa may be smooth, or furnished with
granules, or reinforced by vertical beams, which on cross section or
in the calyx of the coral, look like short regular bars (carzv@) cross-
ing the septum, and extend a short distance on each side (Helophyl-
lum). ‘The upper edges of the septa in the calyx may be spinous,
or smooth. A central rod or columella is frequently present, and

48 NORTH AMERICAN INDEX FOSSILS.

varies in form and texture. The twisting of the septa at the center
may give the appearance of such a structure (pseudocolumella).

In Palzeozoic corals the arrangement of the septa is often clearly
seen to be in four groups (Zetracoral/a) distributed in correspond-
ing quadrants. This arrangement is frequently well marked by —
the course of the lines which on tne exterior indicate the division
between the septa. A main or cardinal septum is distinguishable,
from which at either side branch off secondary septa in a pinnate
fashion (Fig. 75,4). These occupy the two cardinal quadrants, and
are limited by the a/ar septa on the sides of the corallum (Fig. 75,5).
From the alar septa branch off other secon-
dary septa ina pinnate fashion on the side
away from the cardinal septum, these filling
the two counter quadrants which are divided
from each other by the counter septum, which
lies directly opposite the cardinal septum
(Fig. 75, g). The cardinal septum is frequently
reduced so as to leave a marked groove or Fic. 75. Kunth’s dia-
fossula, The secondary septa are often united 8'#™ of tetrameral coral.

; ; : A, cardinal; g, counter;
to each other in such a manner that their united s, 5, lateral on slau
ends form a continuous wall around the fos-
sula, or they may unite in groups, one on either side of the cardi-
nal septum and one near each alar septum. The apparent
grooves thus produced are the pseudofossule. This wall may some-
times close completely so as to form an inner tube, into which the
septa do not extend. Tertiary septa often not reaching the center
occur. In most Mezozoic and later corals the septa occur in mul-
tiples of six, and are often very numerous, most of the cycles of
septa reaching the center.

In compound forms the corallites may be crowded, when they
are generally prismatic in form, or they may be far apart, remain-
ing either entirely dissociated at the upper surfaces, or being con-
nected by a dense or coarse calcareous tissue — the ce@nenchyma.
Sometimes the corallites are connected merely by their strongly *
developed costz. In a few cases they become confluent by in-
complete division, and present the character of winding grooves
with the septa pointing to the center of the groove. When the
septa are absent tabule are generally well developed (/avosites)
which in some forms may be-funnel-shaped (Syrmgopora). The
walls of such corallites are frequently pierced by a more or less

ANTHOZOA. AQ

regular series of round holes or smuval pores. A series of small
shelves or sguame@ are generally found onthe inside of the wall
near these mural pores. In form the COMmpanny coral mass may
be a hemispheric or spherical “head,” a plate-like expansion, or
variously branching with cylindrical branches.

LITERATURE.

1851. Milne-Edwards, H., et Haime, J. Monographie des Poly-
piers Fossiles des Terraines Paléozoiques. Arch. du Museum, Paris,
Vol. V. (describe many American species).

1874. Nicholson, H. A. Palxontology of the Pores of Ontario,
Toronto.

1876, Rominger, C. Fossil Corals. Geol. Surv. Michigan, Vol.
Pie pt. il., pls. 1-55.

1843-87. Hall, James. Palzontology of New York. Vols. t, 2, 3,
6, and Illustrations of Devonian Fossils.

1879. Nicholson, H. A. Tabulate Corals of the Palzozoic Period.
Blackwood & Sons.

1882. Hall, James. Fossil Corals of the Niagara and Upper Helder-
berg Groups. 12th Report Indiana Geol. Surv.

1885. Davis. Kentucky Fossil Corals. Geol. Surv. Kentucky.

1900. Vaughan, T. Wayland. The Eocene and Lower Oligocene
Coral Faunas of the United States. Mon. U.S. Geol. Surv., 39.

1898 to date. Green, G. K. Contributions to Indiana Paleontology.

1899-01. Lambe, Lawrence M. A Revision of the Genera and
Species of Canadian Palzeozoic Corals.’ Geol. Surv. Canada, Contr. to
Canad. Pal., Vol. 4.

KEY TO THE GENERA.
Es Evra ce ns rn sn cadia cine bla rastey ade sivis'sv'tn wicslv'e wine den'sins(eh tise chin domeewiad ie,
* Surface covered by a wrinkled epitheca which extends to the edge of the calyx.. f.
f Coral conical, cylindrical, or compressed conical not composed of invag-

ment C1US OP PANMCIS, (Ser acec tds bdeiscnsw sabe chtnih sy acheuvbaesoacadedive a.
a. Septa well developed, the longer reaching to center...............006 aa.
aa. Central columella well developed, not formed by the septa..... I.

1. Coral compressed, columella spongy, septa numerous in
multiples of six, earlier ones much larger than later ones.
LILI. Flabellum.

I. Coral conical columella projecting and solid............... rd.
11. Columella compressed......... XXVII. Lophophyllum.

EDs, COV I BOATS cs bac doen sh easaesabacr ns Cyathaxonia.

aa. Columella absent, pseudocolumella sometimes formed by twisting
Ba Se Recon atiga area tio ae sual suet aes bith eaves oe Once aeagnende 2.

2. Coral conical (cylindrical), the tetrameral arrangement of
the septa visible in the calyx or in the external septal

ELMMTED. Wance eer seen dere nixnsecnve nike nnsNimaneSoRianeasumtys ie

50 NORTH AMERICAN INDEX FOSSILS.

+ Epitheca normally wanting in basal portion.
XXVI. Duncanella.

{ Epitheca complete (except when denuded)............... 22
22. Septa radial in calyx, rarely uniting or twisted at the
center, fosstla, well developed ):%....) AGA eae cA

x. Septa smooth, tabulz well developed.

(Compare Streptelasma.) II. Zaphrentis.
x. Septa carinate.
40. ( Heliophyllum corniculum).
22. Septa radial, twisted or united in the center, fossula
rarely developed.

(Compare Zaphrentis.) 1. Streptelasma,
22. Septa radial, not twisted at the center. Fossula absent

aoa

Hie. SE DEA, SIMOOUN Fe ic de.t au wah» XIV. Cyathophyllum.
eae wepta ‘canimated ..0.5.0 4. ,45 40, XVI. Heliophyllum.

22... Septa arranged ina bilateral manmer../4.7,--.e HRs
xxx. Strong fossula to which the adjoining septa
COUVERIE) (07: Rekevatecaes 1V. Aulacophyllum.

xxx. Fossula occupied by large cardinal septum,
septa uniting into four groups.
1. Streptelasma profundum.
2. Coral cylindrical, the tetrameral arrangement obscure... 33.

33. Fossula and tabulz well developed ............... HERE.
xxx. Septa twisted at the center and with the tabulz
elevated tent-like ......... V. Acrophyllum.

xaxxx. Septa not twisted or faintly so, sometimes not
quite’ reaching center... 5 Il. Zaphrentis.

33. Fossula weak or absent, tabulze in central portion only.
Roe fe

axxxxx. Septa carinated, fossula occasionally devel-
CBE. eensn tems XVI. Heliophyllum.

HLLLK, Septa SMO p., 063s tk connects oe y-

, Septa reaching to center, fossula absent or
partly developed and faint. *
XIV. Cyathophyllum.
y. Septa not fully reaching center, fossula present
ali fatnit. 5) icc i eseeh ease XV. Campophyllum.
a, Septa well developed, not ‘reaching to center............50+n+-neleaeeee bo.
66. Septa, short strong vertical ridges, tabulze well developed.
VII. Pycnostylus (single branch).
66. Septa normal, reaching part way to center............«scesameme 3
3.. Fossula present \(tarely absetit). ....na..2..-. sehen 44.

44. Cylindrical, with numerous often sharp constrictions’

and well developed tabulz.......... Ill. Amplexus.

44. Cylindrical without constrictions, well developed tabu-
lee onto which the septa extend to within a short dis-

tance val cemberic. a: sari eia a aatusesean Il. Zaphrentts.

44. Conico-cylindrical not constricted, often abruptly bent,
tabulze in cent al vesicular tissue in peripheral area.

XV. Campophyllum.

ANTHOZOA. 51

3. Fossula absent, coral cylindrical, tabulz well developed.
20. Blothrophyllum promissum.

a. Septa faint or absent, interior cystose...............+- X. Cystiphyllum.

t+ Coral conical or cylindrical, composed of a series of invaginated cups or
FOMIELS. 20. 46 caitsaian Van winend’oo¥ a neae ee bok peel ao aaeeece ae a oaee tee ees b.

4. Sepia. well developed, ititerior noteystose< 220. ons ieie cnanaacoeson ces

cc. Cylindrical, of invaginated cups, tabulze well developed, center of
calyx smooth. Fossula present or absent.
VI. Blothrophyllum.
cc. Cylindrical or top-shaped, consisting of invaginated funnels,
sépta‘low,: teaching: centers, pctni iis sath wireanendecw eae 4.
4. Septa twisted in center into pseudo-columella.
IX. Ptychophyllum.
4. Septa ae weak, not twisted, no pseudo-columella.
VIII. Chonophyllum.
6. Septa faint or absent, interior wholly composed of cystose tissue ar-
ranged in a series of funnel-shaped layers. (Compare Chono-

phyllum where septa may be weak.)............... X. Cystiphyllum.

t Coral disk-shaped, with flat or slightly convex base covered by a wrinkled
aca le Dane hae a ee Ere BEE es Piaget Bet (aul eee Oe A &

c. Septa carinated or crenulate, the larger ones reaching the depressed
penter, mo fossulas. spc basen 0s GW ciate caver icons XI. Paleocyclus.

Eerie SmnOGtn, fossila PVESSIt viii se ceescncssscucees Yasees todo ds career vcs add.

a> Iisk shaped, oné fossula tis. ce.sivaiis.decst.oais XII. Microcyclus.

dd. Cushion or top-shaped, septa uniting into four groups, giving
the appearance of two lateral fossulz besides the cardinal one.
XIII. Hadrophyllum.

f Coral with one side flat, and the other arched; operculated and with the

PREM LW RNS, TEGLOOS, «ct gid Shan Sena po edaad ered iwc oas XXIX. Calceola.
* Wrinkled epitheca on lower part only, or rudimentary ................seeeeee seers d.
a -pimucture’of Coral porousy. ii .26 iii sck ites cesesscbins LIX. Balanophylia.
d. Structure solid, center with spongy columella... XLIX. Parasmyla.
RES (0G COUN ECAy Joy 2c.in si choksdd lassi sabVededevesttasstsarecsecsacwsnscas tT.
SRINCLERE WMUULELY POTOUS:..i.50<00 odie bes sui ddcces CUS esdawecinn beseecescenravecs é.
e. Compressed often with lateral wings................. LXI. Endopachus.
mre eiucal, pointed .at base, frees. iiss: tc05, <oxueraser oso LX. Eupsammia.
e. Conical with broad base of fixation, septa more or less united near
OMECL G25 ebay ones ers PP EREINEN Toe ENS LIX. Balanophylia.
PNET POLONSY 15 295.2325 55cb highs cde cepeecap tel. Ge arucko vgoa¥eradceevec oe
jf. With basal scar of attachment, conical, septa granular, columella
BR IMRIYN Aedes ih cs Gas nok, lanwaaattapotmncdsmeaay ree bn hoes XLIX. Parasmylia.
jf. Without scar of attachment, strong costee, and alternate septa uniting.
Wer Porm ‘Comical cos5 1 ecb Ale ee eee ee LVI. Zurbinola.
ee. Vortn Wed@e-Shaped 33) cci.ecs Jorccesasssee sabes LIV. Platytrochus.
6. “Por (disk-Shaped Reiss deisel iaeccaae ees LV. Discotrochus.
8. Corals compound, of loosely branching cylindrical stems each with a terminal
RMB IG EE ie Sica assis hs Son eke owead aaidaudee Uenmadasane Ge Stdbasome dent sgeds «wus *e,
ME ACCRLODOR 0. oo ncrvnrer a hab advert teviey oc deascbartuabaeesteuavles vacteatas TTts
erar As COMME IA PRESERE oo. Gh. 2 ey oil eye ck teas cawilescevdb cbs sesesseas g.

g. Epitheca present, columella rudimentary or wanting.
LI. Cladophyllia.

52 NORTH AMERICAN INDEX FOSSILS.

g. Epitheca wanting, columella papillose, Tree ee ee ce L. Pleurocora.
Pa GME TE PING ER oe urna nw cesic gti h vy eepnaWancashca ocelnahdesigeh Aah teeeeeUEee h.
eo aon jitter wall wres emt. iia. dd Rel B sek laces Esolbe din ca apeach acme He
if. Wall often incomplete, septa carinated.
XXV. Craspedophyllum.
pi Wall complete;:septa not carinatied 4...) ):.ccs.ivuitss ais eelene one 4.
4. Inner tube small, stems uniting by epithecal prolongations.
XXII. Lridophyllum.
4. Inner tube rather large, stems without epithecal prolongations
XXIV. Diplophyllum.
Ax Aer Wall Awa nti cre veistrceen tv tease Swe nas'-sice een aes ae ee ge:
gg. With epithecal proliferations, septa pede to near center.
XXIII. Synaptophyllum.
gg. Without epithecal proliferations, septa in form of short vertical
GEES ih wre Meese sae eo sa onaas Savoia VII. Pycnostylus.
gg. Without epithecal proliferations, septa well developed.
XLIX. Cladophyllia.
%* Septa absent:or represented by spines or faint ridges. .......ic.0.s ciesue nntiat oS
lite Encrusting or attached by whole under side....................ceceeceeeees
?. Pipe-like, buds regular, single or double from near se of a

COTOIY feiss So iect oh eles cok oem ata om Te oan XXX. Aulopora.

7. Cylindrical, irregular branching, on crinoid stems.
XXXIII. Aonzlopora.
tht Free. or only basally attached ie cicwesdinteies wcid scynaeh te one cog Rk.
&. Branches in numerous parallel bundles of thin cylindrical tubes 24.
hh. Branches distinct but united by hollow cross tubes at intervals.
Interior with funnel-shaped tabule. XXXIV. Syringopora.
hh. Tubes united by their sides, forming a chain work. Septa
sometimes quite STONE ......0..scsnss08 epi sas XLIV. Halysites.
hk. Bangles thin, regular or irregular, but not in parallel bundles..... 20.
. Branches in verticils, remote tabulze and occasional mural pores.
XXXI. Romingeria.
72. Branching by bifurcating, dendroid or irregular ; wall reinforced

Dy COARSE CYBER, ccciich wade picinteaite Soa ste oakmen XXXII. Ceratopora.
zz. Branching dendroid or irregular, wall dense, under high power
appears meticulate 2.1, 085). Rae csciintge XXXIII. Monzlopora.

k. Branches coarse, commonly irregular; interior coarsely cystose.
28. Cystiphyllum aggregatum.
C. Coral compound forming heads, expansions or branching stems of numerous con-

tommus corallites, ...5. ice sia tite vds a Web vencse vedas vb t ia deh aaa ee +Ex.

AEP FCaGS Ol CYUNATICAL TUDES. <.eccnceaiacin’ ossowassneren'e ve enatteryne os need ean ST:
5+ Tubes without septa or with septal ridges or spineS................0s ee eeeeee F;

7, Tubes united by porous cross branches’........ XXXIV. Syringopora.

/. Tubes united by vesicular coenenchyma ...... ......... XLV. Lyellia.

7, Tubes united by their sides and forming chains..... XLIV. Hadysttes.
7. Tubes united by their own expansions at intervals.
XXXVIII. Chonostegites.

57 Tubes. with well developed septa............0cs5- tvessuucdvedaas dae geen m.
m. Tubes united™by epithecal proliferations. .s.5.25 0... :.5c0s santas Rk,
kk. Vabes with inner wall jcni0seiek <lepaice oda0i XXII. Lridophyllum.

kk. Tubes without inner wall .............. XXIII. Synaptophyllum.

e
‘.

ANTHOZOA. 53

m. Tubes not united by proliferations, sometimes angular .............. dl.
“7. Tubes with inner wall complete, septa smooth.
XXIV. Diphyphyllum.
“7. Tubesewith inner wall often incomplete, septa carinated.
XXV. Craspedophyllum.
***' Heads, expansions or branching stems of prismatic tubes closely crowded. 6f.
Or. Corallites with: well-devéloped septa... scst2.s4i<\rausietnas aces caaseaanewene n,
mw. With well-marked styliform pseudo-columella.
XXVIII. Lethostrotion,
ye. Without columella, o....2.2. ns saetap ans teutoge.dueateanean ene panaharawesers mm.
mm, Septa carinated ........ eee RMON Tree Rete ear Cyr 5.
5. Head of numerous, comparatively small prismatic corallites.
XVII. Acervularia.
§. Head of afew large corallites iv.icyiiccets. cues sanwerenaces 55:
55. Corallites separated by definite walls,
38. Heliophyllum confluens.
55. Corallites confluent, not separated by definite walls.
XVILI. PArlipsastrea.
UME, HOPRB SHORE 24's acannie iaultepindewnante re ie V ie blneeeOhcaer dau sane 6,
6, Corallites prismatic with expanding calices, 12 strong septa
uniting in adjoining calices. Mural pores regular.
XXXIX. Thecia.
6. Corallites slender prisms, 12 septa, numerous tabulz, no

GEA) PORES (ori 5 csaco cus bseb eaeteee es XXI. Columnaria,

6. Corallites minute, 4 primary septa ...... XLVII. Zetradium.

6. Corallites prismatic, septa of 2 kinds, the longer extending

tothe ‘center; mG tabular i650 62052255 eens LII. Septastrea.

6. Corallites with central part of calyx elevated above periph-

SERN REE oc resus wind acunin madcounteneties XIX. Pachyphyllum.

6} Corallites with septa absent, or represented by low ridges or rows of
BE Facials Woy cisenice vam ndd aS emma RAM aah pea ten es daseu Wasete tania wae Ohcamets 0.

o. Corallites regular prisms, with numerous tabulze .................0008 nn.

nn. Septa in form of low ridges, with costz ; no mural pores.
. XXI, Columnaria.
nn. Septa represented by spines or absent, mural pores in definite
CE areas ss hase canine acum ewemne yanas e Camss 0 oe XXXV. Favosites.
nn. Septa represented by faint ridges; tabulze convex upward ;
mural pores irregularly scattered..... XXXVII. Michelinia.
nn. Tubes opening obliquely, openings crescentic on one side, mural

POTEe Inge, SCHLEFEU ics Accesses sd ens XXXIX. Alveolites.

0, Corailites prismatic, of varying size, tabulze few .................0008 00.
oo. Small hemispheric heads with basal epitheca. Mural pores
regularly SCAltETER ig occcccceccsee XXXVI. Pleurodictyum.

o. Corallites contracting at regular intervals. Tabule convex upward.
Septa tows of spinulles sic). ..c2505+. ck. 0008s. XXXVIII. Chonostegites.

o. Corallites thick-walled, elongate conical, opening obliquely, mural

pores present, tabule few. Commonly branching stems.
XLI. Cladopora.
*** Heads of superimposed strata or layers which are divided into depressed or
elevated pentagonal areas, with septal ridges extending over them. Basal
Seer SENCEANLY DYCKCIVER. «jc. .cccscicsi¥esessvovecssswecsts XX. Strombodes.

54 NORA AMERICAN TIN DEX-FOSSILS.

*** Heads with larger round corallites scattered among smaller angular, often

Miinube ames Pr alos SiN RO SS). 5 ae Lak Lawl denankas ne aesSsomenedveen rie

77 oepteransentsmiural Pores Preset 0.2.5. csesacecns. canis XXXV, Favosites.

7+ Septa present in large corallites, 12 in number; no mural pores......... Dp:

A. Septa/£2 intoldings of wall, short. <...dccdvspoceeecs oss XLVI. Heliolites.

p. Septa well developed, spinulose, smaller corallites imperfect, vesicu-

ose witiSetiensy basics Seeueienes Sv aeakehtethas XLVII. Plasmopora.

D. Corals compound, forming branching stems or expansions with numerous calices
Scaltcted over te SUniaees i sty) aisles donovathewsas bo pudiean eeeee eee <7

Pure. Cremencay iia, Separatine, CAlCES: vi5.0a.ses Wee Goa Casuna Lb Se Sale tele sae St.
Oy Waliees cep ulanGeptate <1) co 0.A 550 Cuore aa eiep eke atRed oc khan eee er q-

g» Columella papillose; ‘coenénehyma densé yi. 5.< ics .iecos se gduvaiew eee Fe

7. Branches cylindrical, calices spirally arranged. LVII. Ocudina.

7. Branches irregular, often flattened and expanded, Calices
SCAMET EME. yor muta nyey see deel wisentee ean LVIII. Astrohelia.

ak+s Branching; (coanenchy tia’ absent; 524 s<.cccc ia. dec can Sackees cenwacs Sone oT

gf Calices distinct, with septal strize surrounding the orifice.
vr. Thick-walled with circular openings, distant superficially.
XLIII. Zrachypora,
r. Thick-walled, circular orifices in polygonally depressed calices.
XLII. Striatopora.

of Cofallites without.septal ‘striae 12... caisessaccivwe+vaentersalen ale ane Ce
s. Corallites thin-walled, openings oblique, crowded, generally curved
CMD) ORE SURG ce) an sah OCR ean dans apron XL. Alveolites.

s. Corallites thick-walled, orifices irregular, distant.... XLI. Cladopora.
s. Corallites opening regularly with polygonal or rounded crowded aper-

tures. Mural pores in regular rows, tabule numerous.
XXXV. Favosites.

Tetrameral Corals.
I. STREPTELASMA Hall.

Simple conical corals, generally curved, with a funnel-shaped
calyx, which is generally deep and furnished with numerous septa,
the longer of which are in some species twisted at the center.
Fossula present in later types. Tetrameral arrangement of septa
shown by their external ends. Epitheca thin. Interior marked
by tabulz. Ord.—Dev.

1. S. profundum (Owen). (Fig. 76, a—d.) Lower Ordovicic.

Deep calyx and few septa, the septa not twisted at the center,
and strongly crenulated in their margins. Primary septa strong
and three pseudo-fossulz well developed, formed by union of ends
of septa next to cardinal and alar septa. Cardinal one double and
divided by cardinal septum.

In beds of Black River, Chazy, and doubtfully Beekmantown
age, Michigan, Wisconsin, Iowa, New York, Canada, etc.

ANTHOZOA—TETRACORALLA. 55

rt
1
i}

T

‘ HH by fa
Wii] the
'

SROUNG Hy ea ee

AMS

Fic. 76. a-b, Streptelasma profundum ; c-d, S. corniculum ; e-f, S. rusticum ; g,
Enterolasma calicula (Lambe-Contr. Pal. ).

2. S. corniculum Hall. (Fig. 76, cd.) Middle Ordovicic.
Corallum curved, calyx moderate, septa numerous, twisted at
the center.
Trenton and Galena limestone, New York, Canada, Iowa
Minn., etc.

3. S. rusticum Billings. (Fig. 76, e+.) Upper Ordovicic.

Fic. 77. Streptelasma ( Enterolasma) Fic. 78. Stereolasma rectum, (a). car-
calicuia (N. Y. State Geol. Surv.). dinal and (4) alar views.

Larger than preceding (214-3% inches), septa coarser and more

strongly twisted, forming a vesicular pseudocolumella at the center.

Lorraine and Richmond beds of Minnesota, Iowa, Indiana,
Ohio and Canada.

56 NORTH AMERICAN INDEX FOSSILS.

4. S. (Enterolasma) caliculum Hall. (Fig. 76, g, 77.) Middle

Siluric.

Small, slender, uniformly tapering corals with moderately deep
cup, and comparatively few (20-50) septa separated by twice their

width, and epitheca thin, showing costal
grooves. Septal ends unite into a reticu-
late pseudo-columella.

Niagara beds of New York, Canada, etc.

5. S. (Stereolasma) rectum Hall. (Fig. 78,
79.) Middle Devonic.
Generally larger and more robust than

preceding, with strongly wrinkled and often

irregular surface, owing to strong epitheca.

Septa comparatively few, uniting at the cen-

ter. A well marked fossula is present.
Hamilton group of NewYork,etc.

II. ZAPHRENTIS Rafinesque.

Fic. 79. Stereolasma
rectum, transverse and

Simple, conical or turbinate corals, becom- !°nsitudinal sections (af-

ing conico-cylindrical in some large species.

ter Simpson).

Calyx deep, with well developed septa, the primary ones gener-

Fic. 80. Zaphrentis gigantea, longitudinal
and transverse sections (Lambe).

ally reaching to the center.
Dissepiments and tabulz oc-
cur, the latter usually well
developed and bent down-
wards at the periphery. A
deep fossula marks the abor-
tion of the cardinal septum.
Epitheca thin. Sil.—Carb.

6. Z. gigantea Lesueur.
(Fig. 80.) Middle Devonic.
Generally of large size be-
coming cylindrical in the
adult. Length sometimes 214
feet with a diameter of three
inches. Bottom of calyx
often shows a tabulum, the
septa not reaching the cen-
ter. Fossula large and deep.
Epitheca strongly wrinkled.

ANTHOZOA—TETRACORALLA. 57

Found in the Onondaga limestone of New York, Canada, Mich-
igan, Ohio. Abundant at the Falls of the Ohio.

7. Z. prolifica Billings. (Fig. 81.) Middle Devonic.

Conical and generally curved, expanding rapidly. Septa meet
at the center of the deep calyx, where they unite more or less.
Broad fossula formed by abortion of cardinal septum.

i yf
A NU,

Fic. 81. Zaphrentis prolifica, lateral (a) and calicinal (4) views (after Billings).

Found in the Onondaga limestone of Michigan, Canada, Ohio,
Kentucky, etc., and in the Hamilton group of Michigan, Canada,
etc.

8. Z. convoluta Hall. Middle Devonic.
Conical and rapidly expanding. The septa unite before reach-
ing the center and become more or less twisting.

In the Onondaga limestones of the Falls of
the Ohio.

9g. Z. simplex Hall. (Fig. 82.)
Middle Devonic. :
More cylindrical than the preceding, regu-
larly tapering, septa scarcely reach the center.
In the Hamilton shales of New York.

10. Z. stokesi E. & H. Siluric.
ape eee aap hrentis Conical and curved with moderately deep
a4 (Pal. N. Y-5 calyx, in which the septa unite in the center
and become twisted as in _Streptelasma. A
stong fossula and tabulz are present.
In the Niagara of Canada, Michigan, Iowa, etc., and in equiva-
Jent beds of Anticosti aud Lake Temiscaming.

58 NORTH AMERICAN INDEX FOSSILS.

11. Z. cliffordana Edwards & Haime. Lower Carbonic.
Corallum a curved cone, with a deep calyx, the septa of which
are all nearly equal in strength, becoming thinner towards the cen-

DiS

Fic. 84. 4. cal-are-
forme. Transverse sec-
tion (Simpson).

Fic. 83. Hapsiphyl-
lum calcareforme (Ind. Fic. 86. Amplexus ham-
Geol. Surv. ). iltonia,

ter. Fossula generally on the side of
least curvature.
In the Kinderhook beds of Illinois, the

: Fic. 85. <Ampl. n-
Chester beds of Ohio, etc. caus plexus ya
del/t with transverse and lon-

12. Z. (Hapsiphyllum) calcareformis 'tudinal ‘sections »(iamiie
: wis ; Contr. Can. Pal.).

Hall. (Figs. 83, 84.) Lower Carbonic. fe

Small, slender and uniformly tapering, sometimes curved. Fos-
sula narrow, outlined by a compressed horseshoe-shaped wall
formed of septa united at the center. Shorter septa joining the
longer which in turn unite with the wall of the fossula.

In the St. Louis limestone of Spergen Hill, Lanesville, Indiana,
and other localities.

13. Z. (Hapsiphyllum) spergenensis Worthen. Lower Carbonic.
Like the preceding, but with two rudimentary pseudofossule,
and short epithecal spines.
Occurs with the preceding.

III. AmpLexus Sowerby.

Generally cylindrical or conico-cylindrical corals, with structure
much like Zaphrentis but with the septa only reaching a short way
out onto the well developed horizontal tabula. A strong fossula
is generally present. Ord. ?—Carb.

ANTHOZOA—TETRACORALLA. 59

14. A. shumardi (E. & H.). Middle Siluric.
Subcylindrical with numerous subregular constrictions all cov-
ered by a thin epitheca. Fossula well developed.
In the Niagara group of Michigan, lowa, Kentucky, Tennessee,
etc.

fem yandelli (EK. & H.). (Pig. 85.) Middle Devonic.
Irregularly cylindrical, often bent, constrictions irregular ; tabulz

more or less irregular.
In the Onondaga limestone of Indiana, Kentucky, Michigan and

Canada.

16. A. hamiltonie Hall. (Fig. 86.) Middle Devonic.
Small, cylindrical, often abruptly bent and constricted. Strong

distant septa reach about a third to the center, and stop abruptly.

Tabulz flat.
Abundant in the Hamilton shales of New York.

IV. AULACOPHYLLUM E. & H.

Like Zaphrentis, but the septa on either side of the fossula con-
verging toward it. Ord.?—Dev.

17. A. sulcatum d’Orbigny. (Fig. 87.) Middle Devonic.

Fic, 87. Aulacophyllum sulcatum (Ind. Geol. Survey).

60 NORTH AMERICAN INDEX FOSSILS.

Regularly curved, with oblique calyx, most of the septa con-
verging to either cardinal or alar septa.
Onondaga of Falls of the Ohio and other localities.

V. ACROPHYLLUM Thomp-
son & Nichols.

Similar to Zaphrentis but
with the tabule elevated
tent-like in the center of
the calyx, the septa running
out on them and twisted at
the center. Dev.

Ete

18. A. oneidaense (Bill-

ings). (Fig. 88.)

Middle Devonic.

Turbinate or subcylin-
drical, with periodic con-
strictions. Sides of calyx
nearly vertical, bottom of cup nearly half the diameter of the coral.
Fossula strong, extending from base of elevation to the margin
of the calyx. |

Onondaga limestone, Falls of Ohio, etc.

Fic. 88. Acrophyllum onetdaense with calyx
partly sectioned (Lambe).

VI. BLoTHROPHYLLUM Billings.

Cylindrical corals, consisting of a series of invaginated cups
which are like that of Zaphrentis in structure, with well-developed

tabule, and generally a marked fossula. Projecting margins of |

the older cups covered by the epitheca, when not wornaway. Sil.—
Dev.

19. B. decorticatum Billings. — Middle Devonic.
Large, with margins of old cups strongly projecting, generally

denuded of epitheca. In the calyx a deep fossula and smooth

central space are characteristic.
In the Onondaga limestones of Michigan, Canada and the Falls
of the Ohio.

20. B. promissum Hall. (Figs. 89-90.) Middle Devonic.
Slender cylinders with margins of old cups generally subdued,

the calyx with a flat central area free from septa, and no fossula.
In the Onondaga beds of the Falls of the Ohio.

ANTHOZOA—TETRACORALLA. 61

VII. Pycnosty_Lus Whiteaves.

Corallum of cylindrical tubes increasing by calicular budding of
three or four branches at distant intervals. Septa in form of short
vertical ridges, tabulz well developed, horizontal. Siluric.

Fic. 91. Pycnostylus
guelphensis with 2 buds sec-
tioned (Lambe).

Fic. 90. Blothrophyt-
lum promissum, Sec-
tioned (Ind. Geol. Sur-

vey).

Fic. 89. Blothrophyllum
promissum (Ind. Geol. Sur- Fic. 92. Chonophyllum niagarense (N. Y. Geol.
vey). Survey).

62 NORTH AMERICAN INDEX FOSSILS.

21. P. guelphensis Whiteaves. (Fig. 91.) Siluric.
Long slender corals from 3 to 7 mm. in diameter. Epitheca
with transverse constrictions and reélevations at irregular intervals,
but no longitudinal ribs.
Common in the Guelph beds of Canada, Wisconsin, Ohio, etc.

VIII. CHonopoytitum E. & H.

Generally top-shaped or subcylindrical corals composed of
invaginated funnels. Calyx large with numerous uniform septa.
Margins of old funnels not projecting. Sil.—_Dev.

22. C. niagarense (Hall.). (Fig. 92.) Siluric.
Cylindrical in the upper portion with frequent constrictions,
septa subdued, spiniform, with notched margins, extending to the
center of the deep calyx.
In the Niagara formation of Western New York, Kentucky, etc.

23. C. magnificum (Billings). Middle Devonic.
Large, top-shaped, with a spreading basin-shaped calyx. Septa
thickening outward.
In the Onondaga beds of Michigan, Indiana and the Falls of
the Ohio. |

IX. PrycHopPpHYLLUM E. & H.

Similar to Chonophyllum but with the septa twisted into a
pseudo-columella, at the center. Sil.—Dev.

24. P. stokesi E. & H. Middle Siluric.
Conical with a deep spreading calyx, furnished with low, broad
septa and a large pseudo-columella. Epitheca with root-like
processes.
In the Niagara beds of Drummond Island, Mich., and Louis-
ville, Ky.

xX. CysTIPHyLLuM Lonsdale.

Simple or compound corals, varying from depressed turbinate to
cylindrical or irregular growth. Entire interior of coral filled with
vesiculose tissue with a cone arrangement of the vesicles. Calyx
without septa or with only faint ridges as in Chonophyllum, from
which genus it is probably derived. A strongly wrinkled epitheca
is present. Sil.—Dev.

—

a

ANTHOZOA—TETRACORALLA. 63

25. C. vesiculosum Goldfuss (= C. americanum E. & H.).

(Fig. 93.) Devonic.

Large, cylindrical, frequently constricted, covered by a thin but

strongly wrinkled epitheca. Calyx with a faint simulation of
septa. Vesicular tissue coarsest near the center.

Fic. 94. Cystiphyllum conifollis (Pal.
Ne eye

Fic, 93. Cystiphyllum vesiculosum. Fic. 95. Cystiphyllum varians (Pal.
ING Ya}is

Abundant in the Onondaga and Hamilton strata of New York,
Canada and Michigan, Ohio, etc., also at the Falls of the Ohio.

26. C. conifollis Hall. (Fig. 94.) Devonic.
Slender, cylindrical, with periodic constrictions. Cysts arranged
radially at the base. of the calyx.
Common in the Hamilton group of New York, Canada, etc.

64 NORTH AMERICAN INDEX FOSSILS.

27. C. varians Hall. (Fig. 95.) Devonic.
Shorter and stouter than preceding, with stronger septal ridges
and coarser cysts arranged cup in cup.
Hamilton group of New York, etc.

Fic. 96. Cystiphyllum aggregatum (after Billings).

28. C. sulcatum Billings. Devonic.

Short conical and curved form (zaphrentoid) with a deep cardinal
fossula, and septa represented
by coarse plications of the
calyx floor. Cystoid structure
not visible in calyx.

In the Onondaga beds of
New York, Canada, Michigan
and the Falls of the Ohio.

29. C. aggregatum Billings.
(Figs. 96-97.) | Devonic.
Compound, of cylindrical

stems more or less closely

crowded.

In the Onondaga limestone
of Canada and the Hamilton
of Michigan.

XI. Patmocycius E..& H. FIG, 97. as REE a var.
. ; (after Lambe).
Corallum simple, disk-

shaped with flat base, or depressed topshaped, the base covered

ANTHOZOA—TETRACORALLA. 65

with a strong epitheca. Septa numerous, radial, in sevéral cycles
the larger ones reaching the center. Siluric.

30. P. rotuloides Hall. Siluric.
Center with a strong depression. About 20 thick crenulated
primary septa and an equal number of secondary ones. Base with
sharp costal ridges.
In the Clinton beds of New York.

XII. Microcyctus Meek & Worthen.

Disk-shaped coralla, with a flat base covered by an epitheca,
with numerous radiating septa and a septal fossula. Devonic.

31. M. discus M.& W. (Fig. 98.) Devonic.

Fic. 98. Microcyclus discus (enlarged, Fic. 99. Hadrophyllum a’ orbignyt (en-
<2). larged X 2).

Center depressed, smooth, adjoining septa uniting half way to
center, fossula well marked.- Base flat and with a concentrically
striate epitheca.

In the Hamilton beds of Canada and Illinois.

XIII. Hapropuytium FE. & H.

Cushion-shaped to top-shaped coralla, the base covered by an
epitheca. A large cardinal fossula and two small lateral pseudo-
fossulz occur. Devonic. ;

32. H. d@’orbignyi E.& H. (Fig. 99.) Devonic.

Flat cushion-shaped, the septa uniting before reaching center ;

pseudo-fossulz sometimes wanting.
In the Onondaga beds of the Falls of the Ohio region.

XIV. CyATHOPHYLLUM Goldfuss.
Corallum simple in primitive species but becoming compound in
more specialized types. Corallites conical, generally cylindrical in
5

66 NORTH AMERICAN INDEX FOSSILS.

the later stages of growth. Septa simple, without carine, extend-
ing to the center of the calyx where they are more or less twisted.
One or more fossulz present in some species. Tabulz in central,
cystose structure in peripheral areas. Ord.?—Carb.

33. C. robustum Rom. Middle Devonic.
Generally large, growth irregular, calyx deep, septa low, thin
and sharp, the longer reaching the center and uniting. Fossula
faint. e
Hamilton group of western New York, Ontario and Michigan.
Also at the falls of the Ohio.

34. C. conatum Hall. (Fig. 100.) Middle Devonic.

Fic. 100. Cyatho-
phylum conatum( Pal.,
ey rhe

Fic, 101. Campophyllum torquium with cross section (Ind.
Geol. Surv. ).

Cylindrical, generally small, and of irregular growth. Septa
strong and regular reaching the center. No fossula. Has many
characters of Llothrophyllum.

In the Hamilton group of New York and Ontario.

35. C. alpenense Winch. Devonic.
Cylindrical to conico-cylindrical, rather smooth; calyx deep
with steep sides marked by septa of a triangular cross-section.
‘labulz well developed in central portion.
Abundant in the Hamilton beds of Michigan.

ANTHOZOA—TETRACORALLA. 67

XV. CAMPOPHYLLUM E. & H.

Differs from Cyathophyllum, in that the septa stop short some
distance from the center. The central area with well developed

Fic. 102. Seliophyllum
halti (Pal., N. Y.).

tabulz, the interseptal space with dissepi-
ments. Dev.—Carb.

36. C. torquium (Owen). (Fig. 101.)
Middle Carbonic.

Cylindrical, often very long (9g inches or
more) and abruptly bent. Epitheca very
thin generally denuded. Calyx deep with
a moderate fossula, principal septa extend-
ing one half to two third distance to cen-
ter, secondary ones very short.

In the coal measures of Illinois, Iowa,
Kansas, Missouri and Nebraska.

XVI. HELIopHyYLLUM Hall.

Like Cyathophyllum, but the septa with transverse plates or carinz
which are few and weak in young or primitive species, but numer-
ous andstrong inothers. A fossula is frequently developed. Dev.

Fig. 103. Heliophyllum confuens.

68 NORTH AMERICAN INDEX FOSSILS.

a7. Hy halli EB. &. A. (Figy4oes) Middle Devonic.
Broadly turbinate at the base or in young specimens, becoming
cylindrical in old individuals, frequently with irregular constric-
tions showing rejuvenescence. Epitheca strongly wrinkled.
Abundant in the Hamilton group
of New York, Ontario, Ohio,etc., and
at the Falls of the Ohio.

38. H. confluens Hall. (Fig. 103.)
Middle Devonic.
Likethe preceding but compound,
the corrallites large, and polygonal
from crowding.
In the Hamilton group of New
York, Canada, Ohio, etc.

39. H. tenuiseptatum (Billings).
Middle Devonic.
Generally small, more or less cylin- Fic. 104. Helophyllum cornt-
drical, with numerous fine and thin ,,.7,.. (Ind. Geol. Surv.).
septa, strongly carinated.
Common in the Hamilton group of New York, Ontario, etc.

40. H. corniculum (Lesueur). (Fig. 104.) Middle Devonic.
Conical and curved at the base, general aspect like Zaphrents.
Calyx deep, with steeply sloping sides; broad nearly flat bottom,
numerous alternating carinated septa and a well marked fossula.
Common in Onondaga limestones of New York, Ontario, Indi-
ana, etc., and at the Falls of the Ohio.

XVII. ACERVULARIA Schweigger.

Coral heads astreiform, composed of prismatic corallites with

numerous septa, the longer of which reach the center. The ap-
pearance of an inner wall is caused by crowded dissepiments at the
same level. Base of colony covered with a strong peritheca. Sil—
Dev. |

41. A. rugosa (E. & H.). (Fig. 105.) Devonic.
Corallites from 10 to 15 mm. in diameter, individuals ribbed
longitudinally on the exterior and with transversely wrinkled epi-
theca. Larger septa meeting and sometimes twisting in the center,
carinze moderately developed.
In the Onondaga beds of Michigan, the Falls of the Ohio, etc.

a

ANTHOZOA—TETRACORALLA. 69

42. A. davidsoni E.& H. (Fig. 106.) Devonic.
_ Centers of calices abruptly depressed, diameter about 10 mm.
Septa alternating in length but equal in thickness at the margin

of the calyx, carinz abundant.

Common in strata of Hamilton age in Michigan, Iowa, etc., and

id HY) XA] gz
Rann ieeseate,

Z

H

os

Sox Fy
{]

2

OR!
uy

a"
a%
2aq
sas

GuvvEV Ey:
S
cy
ee

ie Geet
a ey HH rin ae
THT] HEY ats
SES pee
ttt NBO A
teeny >. sn ome
FIG. 105. Acervularia rugosa (after Fic, 106. Acervularia davidsoni (after

Simpson).

Simpson).

also found in strata of somewhat earlier age at the Falls of the

Ohio and elsewhere.

XVIII. Purtuipsastr#A D’Orbigny.

Coral heads composed of large confluent corallites, similar to
compound Helophyllum, but without the dividing walls. Calicular
surfaces flat, except at the center, where an abrupt depression,
usually surrounded by an elevated rim occurs. Longer septa

WZ 7 ) yy: FB
= = Ii Mf! = SS NY Zi c=
Wf} ; N= we a

I
a

SS
>= +

yi

4

AK MWK
Fic. 107. Phillipsastreaa verneuilli (after
Billings).

uniting at the center,
shorter stop at the central
pit. Dev.—Carb,

43. P. gigas Owen.
Devonic.
Large, the calices over
20 mm. in diameter and

their outlines defined; cen-
tral pit large.

In the Onondaga lime-
stone of New York, Can-

ada, Michigan and the Falls of the Ohio. Hamilton of Michigan.

44. P. verneuilli E.& H. (Fig. 107.)

Devonic.

Smaller, corallites from 10-15 mm. in diameter.

70 NORTH AMERICAN INDEX FOSSILS.
Onondaga of Canada, Michigan, etc.

XIX. PacuypHyi_tum E. & H.

Compound corallites bounded by polygonal walls, each with a
central conical elevation, at the top of which is a crater-like pit.
Septa extending over the outside of the cone as low ridges or
coste. The longer septa extend to within a short distance of the
center. Dev. |

45. P. woodmani (White). (Fig. 108.) Upper Devonic.
Growing in convex or hemispheric masses from I to 6 inches in
diameter; crater rims strongly elevated, sometimes more than an
eighth of an inch. Crater deep and variable in diameter.
In the Upper Devonic of Iowa, etc.

XX. STROMBODES Schweigger.

Coral composed of superposed layers or laminz, on the surfaces
of which are polygonal depressions representing the calices with

Fic. 108. Pachyphyllum woodmani(N. Fic. 109. Strombodes pentagonus (after
Y. State Mus. Rep.). Lambe). ,

the central part marked by an abrupt circular pit. Calicinal surface
with radial septal ridges, which unite in the center in a papillose
projection. Sil.—Dev.

46. S. pentagonus Goldfuss. (Fig. 1c9.) Siluric.

Calices shallow from 10 to 15 mm. in diameter; center with a
styliform columella, septa sharp at the pit, becoming low rounded
ridges at the margins.

In the Niagara beds of Michigan, the Falls of the Ohio, etc. —

ANTHOZOA—TETRACORALLA. 7}

47. S. striatus Owen. Siluric.
Much larger than the preceding, the calices ranging to 40 mm.
in diameter. Elevation around central pit pronounced.
Occurs with the preceding.

48. S. mamillatus Owen. Siluric.
Margins of calices depressed, center strongly elevated with a pro-
nounced crater-like pit at the top from 4 to 5 mm. in diameter. Dis-
tances between centers of pits of adjoining corallites 10 to 20 mm.
In the Niagara beds of Michigan, lowa, Kentucky, Indiana, etc.

XXI. CoLtumnariA Goldfuss.

Heads consisting of prismatic corallites, like that of Fazosztes,
but without mural pores, and with the septa either well marked or
indicated by vertical ridges. Tabule well developed. Ord.—Dev.
49. Columnaria halli. (= C. alveolata of most authors.)

Middle Ordovicic.

Septa represented by from 20 to 40 vertical ridges. Tabulz flat,
close and smooth in the centers. Tubes variable in diameter
from 2to 5 mm.; sometimes IO mm. tubes,
occur among the smaller ones.

In the Black River limestones of New
York, Canada and Michigan, and in strata of
the same age in Wisconsin, I[llinois and Iowa,
etc.

50. C. alveolata Goldfuss. (= Favistella

Fic. 110. Columna- stellata Hall.) (Fig. 110.)

ria alveolata. Horizon- Upper Ordovicic to Siluric.
tal and vertical sections

eek! Tubes varying from 3 to 6 mm. in diame-

ter. Septa from 20 to 30, alternatingly larger
and smaller, the former extending to the center. Center of tabule
marked by the septa. Common in the beds of the age of the
Cincinnati group throughout the central west Also recorded by
Rominger from the Niagara Group of Point Detour.

XXII. ErrpopaHytium E. & H.

Heads composed of loosely aggregated cylindrical corallites each
surrounded by a wrinkled epitheca, from one side of which pro-
longations extend uniting adjoining corallites. An inner wall en-
closing a narrow tabulate area is present. Sil—Dev.

72 NORTH AMERICAN INDEX FOSSILS.

51..H. rugosum bE. & H. (Figs. 111; 113, 2) Siluric.

Corallites less than 10 mm. in diameter, with prolific calicinal
budding, outline cylindrical with subregular constrictions, epi-

‘lp intl
‘in

Fic. 111. Lridophyllum rugosum (Ind. Geol. Survey).:

thecal prolongations spiniform. Septa extending to within a short
distance of the center, which is occupied by tabule.
Common in the Niagara beds of Indiana, Kentucky, etc.

52. E. vernuillianum E.& H. (Fig. 112.) Devonic.
Tubes 7 to 10 mm. in diameter, distant about their own diameter.
Strong epithecal proliferations. A sharp thin inner wall enclosing
a space about 2 mm. in diameter not crossed by septa.
In the Onondaga beds of northern Ohio and adjacent regions.

53. E. colligatum (Billings). Devonic.
Cylindrical stems expanding at regular and uniform intervals so

as to unite in polygonal outlines, after which they contract and |

——S erro

ANTHOZOA—TETRACORALLA. 73

again become round. Septa crenulate alternating, the longer
abutting against the inner wall.

Fic. 112. Eridophyllum vernuilhanum Fic, 113, a. Lridophyllum rugosum ;
(after Billings). b, c. Synaptophyllum simcoense (after
Simpson).

In the Onondaga beds of Canada, Michigan and the Falls of
the Ohio.
XXIII. SyNAPTOPHYLLUM Simpson. —
Like Eridophyllum but without the central wall, the septa extend-
ing across the tabulate area to near the center. Proliferations from
all sides of the tubes. Dev.

54. S. simcoense Billings. (Figs. 1134-115.) Devonic.
Similar in form to Endophyllum vernuillianum but smaller in
diameter, 2. ¢., from 4 to 6.5 mm. and distant
the same amount or somewhat less. Septa
from 40 to 50.
In the Onondaga limestone of New York,
Canada, Michigan and the southwest.

55. S. stramineum Billings. (Fig. 116.)
; Devonic.
ee syiapro- ogee from 4to5 mm.in Agen varying
phyllum simcoense (after fore ——- in contact to more than twice
Billings). their width apart. Central tabulate area large,
septa about 40, extending to near center.
In the Onondaga limestone associated with the preceding.

XXIV. DIPLopHYLLUM Hall.

Corolla similar to Syuxaptophyllum but without the connecting
epithecal expansions. Tabulate area large. Sil—Dev.

74 NORTH AMERICAN INDEX FOSSILS.

56. D. cespitosum Hall. (Fig. 117.) Siluric.

UUW) ¢

Sarl ‘lit
bm

Fic. 115. Synaptophyllum simcense (Ind. Geol. Surv.).

Fic. 116. Synaptophyllum stramineum (Ind. Geol. Surv.).

Slender cylindrical stems with a broad central tabulate, and a
narrow peripheral zone. Septa thin, reaching the center.

ANTHOZOA—TETRACORALLA. 78

In the Niagara and Guelph beds of New York, Canada, Wiscon-
sin, etc.
57. D. panicum (Rominger). |
Large stems, about 10 mm. in diameter and multiplying by

prolific calycinal gemmation. Abouta third of the tubes occupied
by the rather vesiculose compound tabule,

the outer zone by the carinate septa.
In the Hamilton beds of Michigan.

Devonic.

Dnt
WAN

ca i)

Da

)

=

=

58. D. arundinaceum (Billings).
Devonic.

Differs from the preceding by the nar-
Fie. 117. Liplophyl- ower vesicular zone, and regular tabule.

lum cespitosum (after : . e :
Septa not reaching center. Diameter of

Lambe).
tubes 6-10 mm.
In the Onondaga limestone of New York, Canada, etc.

XXV. CRASPEDOPHYLLUM Dybowsky.

Heads of cylindrical corallites as in Aridophyllum, but without
the epithecal prolongations and with the inner wall open on one
side, rarely closed, not crossed by the carinated septa. | Devonic,

~
S

<

Olie
Ui il hi;

#. j/ 4 V7

Fic. 118. Craspedophyllum archiact.

59. C. archiaci (Billings). (Fig. 118.) Devonic.
Stems nearly or quite in contact, sometimes becoming prismatic

from crowding, diameter from Ioto 20mm. Calices deep. Septa
of the first cycle joining the horseshoe-shaped inner wall.

76 NORTH AMERICAN INDEX FOSSILS.

In the Hamilton beds of New York, Canada, Michigan, etc.
Also in Devonic limestones of Ohio.

60. C. subcespitosum (Nicholson). Devonic.

Smaller than the preceding, of long slender stems increasing
chiefly by lateral gemmation. Septa more numerous and more
closely crowded than in the preceding, strongly carinated. Inner
wall often closed in the adult.

Common in the Hamilton beds of New York, Canada and
Michigan.

XXVI. DuncanELta Nicholson.

Coral slender, resembling Szreptelasma, with radial septa, and a
strongly developed epitheca which, however, is absent at the base
of the corallum, where the septa are visible. :
Siluric.

61. D. borealis Nicholson. Siluric.

Small, slender, and scarcely over half an
inch in length. Costz well developed.

In the Niagara group of Indiana and else-
where. |

XXVII. LopHorpuyttum E. & H.

Corallum zaphrentoid, but with a central
compressed columella often continuous on
one side with the cardinal septum. Carbonic,

62. L. profundum (FE. & H.). (Fig. 119.)
Carbonic.
Curved, horn-like corallum, with septa from
30 to 50 alternating in length. Columella
striated. Length of average individual 30
mm., width of calyx 9 mm.
In the coal measures of Iowa, Illinois, Kansas, Nebraska,
Texas; etc.

Fic. 119. Lophophyl-
lum profundum (Ind.
Geol. Survey).

XXVIII. Lirxosrrotion Lhwyd.

Heads composed of prismatic or cylindrical corallites, each
enveloped by an epitheca and all by a peritheca. Central portion
occupied by tabulz which are inverted funnel-shaped, terminating
in the calyx in a pseudo-columella. Septa well developed, outer
area with numerous dissepiments. Carbonic.

ANTHOZOA—TETRACORALLA. 77

63. L. mamillare E.& H. (Fig. 120.) Lower Carbonic.
Prismatic corallites, with moderately deep calices marked by the
conical elevation which is carinated by the septa and terminates in
-a compressed pseudo-columella.
In the lower Carbonic (St. Louis) limestone of Michigan, the
Mississippi Valley and Southern Appalachians generally.

'
D
Fic. 120. Lithostrotion mamillare (Ind. Geol. Survey).

XXXIX. CALcEOLA Lamarck.

Coral simple with one side flattened and a deep calyx opening
obliquely and furnished with an operculum; septa in the form of
low ridges. Structure densely cystoid. Sil.—Carb.

64. C. tenneseenensis Rom. (Fig. 121.) Siluric. |
Strongly curved, with a high arched operculum and interior
largely occupied by vesicular tissue.
In the upper Niagara beds of Tennessee.

78 NORTH AMERICAN ANDEX FOSSILS.

Tabulate Corals.

XXX. AuLopora Goldfuss.
Compound corals attached for the greater part to shells, corals
or other foreign bodies and consisting of a number of simple cor-
nucopia-shaped to cylindrical tubes, each arising by budding from

Fic. 121. Calceola tenneseenensis. Fic. 122. <Aulopora subtenuis enlarged
(Pal; Na ¥¥).

below the calyx mouth of its parent, with which it remains united
bya persistent pore. Tabula seem to be present in some species.
Septa represented by vertical ridges. Ord.—Carb.

65. A. subtenuis Hall. (Fig. 122.) Devonic.
Slender curving tubes very gradually enlarging. Generally a
single bud only. Length of tubes about 8 mm., diameter at aper-
ture I mm.
Common in the Helderbergian of New York, etc.

66. A. serpens Goldf, (Fig. 123.) Middle Devonic.
Attached by whole under surface; calices oblique upward, buds .

Fic. 123. Aulopora serpens on brachi- Fic. 124. Aulopora tub@eformis on
opod shell. Spirifer.

one or two, commonly reuniting so as to form meshwork. Com-
monly attached to brachiopods.
In the Hamilton shaies of New York, Ontario and Michigan.

ANTHOZOA

TETRACORALLA. 79

67. A. tubeformis Goldf. (Fig. 124.) Devonic.
Larger than preceding, with corallites crowded and occasionally
uniting laterally.
In the Hamilton beds of New York, Canada, etc.

68. A. cornuta Bill. (Fig. 125.) Devonic.
Less crowded, mouths of corallites about twice as large as pre-
ceding.
Onondaga and Hamilton of Canada, etc.

Fic. 126. Romingeria umbellt-
Fic. 125, a—c. Aulopora cornuta (after Billings). fera (after Billings).

XXXII. ROMINGERIA Nicholson.

Auloporoid tubes with the buds given off in a verticil. Remote
tabule, and occasional mural pores present, growth erect. Sil.—Dev.

69. R. umbellifera (Billings). (Fig. 126.) Devonic.
Tubes about I mm. in diameter, delicately annulate by growth
lines. Verticils from 6 to 12 buds, remaining at first close to-
gether, then bent rather abruptly outward radially.
Onondaga limestone of New York, Canada, Michigan, etc., and
Hamilton group of Michigan.

XXXII. CERATOPORA Grabau.

Coral like Awlopora in appearance, but tubes often much larger,
and never attached except at the base. Walls thickened by the
formation of coarse cysts, from the surfaces of which sharp spines
arise. Central space commonly open, the individual corallites re-
maining connected. Epitheca generally well marked. Devonic.

70. C. jacksoni Grabau. (Figs. 127, 128.) Middle Devonic.
Branches budding at irregular intervals, tubes large and coarse,
with longitudinal striation, marking the epitheca. Cysts coarse
and irregular.
In the Hamilton group of New York, Michigan, etc.

80 NORTH AMERICAN INDEX FOSSILS.

71. C. dichotoma Grabau. (Fig. 129.) Middle Devonic.

Prostrate, tubes with flattened lower and carinated upper portion,
and abruptly up-bent circular calices. Buds in pairs, at right
angles to each other. Cysts small.

Fic, 128. Ceratopora jacksoni.
Transverse and longitudinal section,

Fic. 127. Ceratopora jacksoni.

Fic. 129. Ceratopora dichotoma. Nat. size (a) and enlarged (é-d).

In the Hamilton beds of New York, Ontario, Michigan and the
Falls of the Ohio.

72. C. intermedia (Nicholson). Middle Devonic.

Small cylindrical, loosely branching corallites forming a colony
which probably grew erect. Epitheca smooth with only growth
lines.

ANTHOZOA—TABULATA. SI

In the Hamilton group of New York, Ontario, Michigan, etc.
Other species are abundant at the Falls of the Ohio.

XXXIII. Monitopora Nicholson & Etheridge.

External form similar to Cevatopora, but wall composed of
parallel layers separated slightly, and connected by numerous

Fic. 130. Monilopora beechert, a, 6, nat. size; c, enlarged cross-section ; d, portion
of ¢ still further enlarged.

transverse bars or trabeculz, which, in section, give a regular net-
like appearance. Dev.—Carb.

73. M. antiqua Whiteaves. Devonic.
Slender branches, surface reticulate. Free, or encrusting crinoid
stems.
Hamilton beds of Canada and the Falls of.the Ohio.

74. M. beecheri Grabau. (Fig. 130.). Lower Carbonic.
Free growing, or encrusting crinoid stems, sometimes forming a
confused agglomeration. Epitheca smooth except for growth lines,
tissue very dense, the lacune small and scattered.
Common in the Keokuk beds of the Mississippi valley.

$2 NORTH AMERICAN INDEX £OSSILS.

XXXIV. SyRINGOPORA Goldfuss.

Coral consisting of numerous irregular cylindrical tubes which
grow parallel but generally separated, and have at intervals trans-
verse hollow, tubular connecting processes. Interior filled with
funnel shaped tabula. Young as in Aulopora.
Septa represented by spines. Sil.—Carb.

75. S. verticillata Goldfuss. Siluric.
Tubes separated by from one to two or more

times their diameter (2 to 3 mm.) connected at

distant intervals by transverse tubes of which 2 FIG. 131.) Sie

or 3 are given off at the same plane. Eka oe ae
Niagara group of Canada, Michigan, etc. '

76. S. retiformis Billings. (Fig. 131.) Siluric.
Tubes a millimeter or somewhat less in diameter, irregularly

bending or geniculate, joining where in contact but not by tubes.
In the Niagara beds of New York, Canada, Kentucky, etc.

77. S. tubiporoides Y. & S. Devonic.
Tubes not parallel, about 3 mm. in diameter and separated by
greater distances.
Onondaga limestone of Kentucky, etc.
78. S. maclurei Billings. (Fig. 132.) Devonic.
Tubes about 25 mm. in diameter, more regular than preceding,
but coming closer together at more or less regular intervals..

Fic. 132. Syringopora FIG. 133. Syringopora Fic. 134. Syringopora
macluret. hisingert. perelegans.

(After Billings. )

In the Onondaga limestone of New York, Canada, Michigan, etc.
79. S. hisingeri Billings. (Fig. 133.) Devonic.

Corallites are slender tubes of less than I mm. diameter, sepa-
rated by their own width or a little less or more. Frequent con-
necting tubes occur.

ANTHOZOA—TABULATA. 83

In the Onondaga limestone of Canada, Michigan, Ohio, New
York, Indiana, Kentucky, etc.

80. S. tabulata E. & H. Devonic.

Fic. 135. Syringopora perelegans (Ind. Geol. Survey).

Corallites slender as in the preceding, but closer together and
parallel. Connecting tubes at uniform levels, giving the appear-
ance of horizontal floors connecting the corallites.

Fic. 1362. Favosites venustus.

In the Onondaga limestone of the Falls of the Ohio and else-
where.

84. NORTH AMERICAN INDEX FOSSILS.

81. S. perelegans Billings. (Figs.
134-135.) Devonic.
Between S. macluret and S. hisingert.
Associated with the preceding species.

XXXV. Favositzs. Lamarck:

Corallum massive, more rarely
branching, commonly forming heads
which may be a foot or more in diam-
eter. Corallites prismatic, thin, in con-
tact but not amalgamated by their walls,
which are perforated. by equidistant
mural pores in one or more rows.
Septa rudimentary or obsolete. Nu-
merous more or less regular tabula di- py, 1 36,, Tavicie
vide the intrathecal space. Peritheca enlarged sections (N. Y. Geol.
present on the under side of the Survey).
colony, and usually strongly wrinkled. Ord.—Carb.

82. F. venustus (Hall). (= +. hisiugen E. & Hoey
136 a—b.) ~ Siluric.
- Heads hemispheric or spheroidal, up to 2 or 3 feet in diameter,
with twelve ascending septal spines, generally visible in section.
Jn the Niagara group (Lockport beds) of New York, Ontario,
Michigan, Cumberland Md., Ohio and Kentucky.

83. F. favosus (Goldfuss). (Fig. 137.) Siluric. —
Tubes large —up to 6 mm. in diameter with the inside marked

a (fF

i GENEATTE et,
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\y

‘i
‘AK nai
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ly

Zs

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ig

ee
D:

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—* ? Ne ol *
Nit
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i ell

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; sil he

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eg
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e fs
.
h

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S.

iat

=

F-3
=

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x)

faa :
ae ae a
ed

OE tae

Fic. 137. Favosites favosus (Ind. Geol. Survey).

ANTHOZOA—TABULATA. 85

by twelve longitudinal furrows and by granulations. Tabulz
granulose, with their margins deflected into 12 (+E) pits or notches
corresponding to the longitudinal furrows, marginal pores com-
monly in more than two rows.

In the Niagara group of New York, Ontario, Michigan, Wis
consin, Iowa, and the Falls of the Ohio region.

84. F. niagarensis Hall. Siluric.
Tubes much smaller than in the preceding species (about 1.5
mm. in diameter), tabule rarely notched at margin; mural pores
scattered near the angles of the tubes. Inner surface of tubes deli-
cately spinulose.
In the Niagara group of New York, Ontario, Michigan, Iowa
and Kentucky.

85. F. helderbergie Hall. (Fig. 138.) Lower Devonic.
Heads lenticular or hemispherical, often large, and with the base
covered by a strongly wrinkled epitheca. Calices about 1.5 mm.
in diameter with strong longitudinal ridges.. Mural pores in one
or two rows, with elevated rim. Tabule close.
In the Lower Helderberg beds of New York and at Cumberland,
Md. i

86. F. winchelli Rom. Devonic.

Tubes much as in /. favosus, but with the marginal notching
rare. Not infrequently the whole rim of the septum is turned
down. Interior of tube with twelve well-marked longitudinal
furrows, without squame.

Fic. 138. avosites helderbergie (reduced) with a group of corallites enlarged
(Paki Ne: Vi

86 NORTH AMERICAN INDEX FOSSILS.

In the Onondaga limestone of New York, Canada, Michigan
and the Falls of the Ohio. Also in the Hamilton group of
Michigan.

87. F. basalticus Goldfuss. (Fig. 139.)
Devonice.

Tubes of medium size, sometimes unequal,
tabule complete, not very close together, the
squame often not preserved. Generally only
a single line of mural pores on each wall.

In the Onondaga limestone of New York,
Canada and Northern Ohio.
88. F. tuberosus Rominger. Devonic.

Columns of medium size (2-3 mm.), from two to three rows of
mural pores on each face, and two rows o/ stout horizontal squamez
on inside of each face; the squame of adjoining rows alternating
and often interlocking. Pores surrounded by small pits. Oper-
cula frequent and concave.

In the Onondaga limestones of western New York, Canada,
Michigan and the Falls of the Ohio.

89. F. epidermatus Rominger. Devonic.

Differs from /. zzberosus in irregular arrangement of squamz and
in elevated ring around the small distant pores in rarely more than
two rows. Interior of tubes with twelve longitudinal furrows
which are commonly visible in reverse on the outside of solid col-
umns. The squame are on the spaces between the grooves and
the tabulz are complete.

Common in the Onondaga limestone of Western New York,
Canada, Michigan, Indiana and Kentucky.

Fic. 139. Favosites
basalticus (enlarged).

go. F. emmonsi Rominger. Devonic.

Tubes from I1to1% mm.indiameter. Tabule for the most part
very irregular, closely crowded and compound from union with
squamz ; pores large, irregular, in from I to 3 rows and often
crowded. Differs from /. efzdermatus in the crowded incomplete
tabule and in the large crowded pores.

In the Onondaga limestone of New York, Canada, Michigan,
Ohio, Kentucky, etc.

gi. F. turbinatus Billings. Devonic.

Form turban-like, often simulating Cyathophylloid corals, z. ¢.,
cup-like; generally curved in the basal portions and not infre-
quently looking like the mold of large pelecypod shell. Coral-

ANTHOZOA—TABULATA. 87

lites curving outward, with their mouths nearly at right angles to
the main axis of the coral, from I to 2 mm. or more in diameter,
closed in perfect specimens by concentrically striated opercula.
Pores generally in single rows ; tabulz complete averaging I.5 mm.
apart, squame generally not prominent.

In the Onondaga of western New York, Canada, Michigan,
Ohio and at the Falls of the Ohio, and in the Hamilton of Canada
and Michigan.

92. F. hamiltonie Hall. (Syn. /& dilingst Rom.) (Fig. 140.)
Devonic.
Corals in form of hemispheric heads with the base covered by
a wrinkled peritheca. Adult corallites up to 2.5 mm. in diameter,
generally surrounded by smaller immature ones. Mural pores in
two rows, frequently obscure, tabule perfect, sometimes crowded,
more generally from 2 to 4 mm. apart, not infrequently with mar-
ginal notches. Fasily recognized by its distant perfect tabule.
Abundant in the Hamilton groups of west-
ern New York, Canada, etc.

93. F. alpenensis Winchell. Devonic.
Differs from /. hamiltonié in its manner of
growth, which results in the formation of
rounded or tuberose masses, with generally
only a small space for attachment; in the
somewhat smaller corallites, which are rounded
tubes on the interior owing to the thickening
of the walls, and in the more crowded tabule.
Very common in the Hamilton (Traverse) group of Michigan.
Also in northwestern Canada (Manitoba, etc.). At Alpena a vari-
ety forms large heads in the coral reefs.
94. F. canadensis (Billings). (Fig. 141.) Devonic.
Generally a more or less flat or undulating expansion, sometimes
digitate. Circular tubes, about I mm. in diameter, are scattered
subregularly between small angular
ones, of about one third their size.
Simple tabule in the smaller, and
tabulz complicated by squamez in the
larger ones. Opercula often present.
In the Onondaga limestone of New
York, Canada, Michigan, Indiana and
Kentucky. | 3

MS

)
4
J ek
= 28:

=

Min 2 ila Ld

> Tae

FIG. 140. Favosites
hamiltonia.

Fic. 141. Favosites canadensis
(after Billings).

88 NORTH AMERICAN INDEX FOSSILS.

(The ramose or digitate varieties lead to #. radiciformis Rom.)

95. F. placenta Rominger. Devonic.

Grows in broad, generally thin expansions of an undulating
character, the base covered by a wrinkled peritheca. Calices less
than a millimeter in diameter with clusters of smaller ones scattered
about. In some specimens (especially young ones), the larger
tubes are circular and scattered about separately thus forming
transition types from /., canadensis. Tabulze of smaller tubes
simple, of larger, complicated with squame. Pores uniserial.

Abundant in the Hamilton group of Canada and Michigan —
also in the same formation in western New York.

96. F. digitatus Rominger. Devonic.
Irregular finger-like stems, calices polygonal from one to one and
a half millimeters in diameter. Well developed transverse squame.
Abundant in the Hamilton beds of Canada, Michigan and other
regions.

97. F. clausus Rom. Devonic.

Like the preceding, but with large round calices and small
angular ones as in /. canadensis. Yhe coarse thick branches of
this general type are / radiciformis Rom. :

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Fic. 142. Favosites limitaris (Ind. Geol. Surv. ).

ANTHOZOA—TABULATA. 89

Common in the Onondaga and Hamilton beds of New York.
Canada, Michigan, and the Falls of the Ohio region.

98. F. limitaris Rom. (Fig. 142.) Devonic.

Cylindrical, commonly branching stems 5 to 15 mm. in diam-
eter. Calices circular, opening at nearly right angles to the axis
of the branch. Walls thick, the division lines between the coral-
lites shown only in certain states of preservation.

Common in the Onondaga limestones of the Falls of the Ohio.
Also in the Onondaga and Hamiiton of New York, Canada,
Michigan, etc.

XXXVI. PLEURODICTYUM Goldfuss.

Corallum depressed, discoidal, lower surface covered by a con-
centrically wrinkled peritheca. Corallites small, prismatic, funnel-
shaped ; septa faint or obsolete, a scanty development of tabulz
occurring; mural pores irregularly distributed. Young cells as in
_Aulopora. Devonic.

99. P. stylopora (Eaton). (Fig. 143.) Devonic.
Heads from I to 2 inches in diameter, septa faint, forming a
crenulation on the calyx margin; tabulze moderately numerous.
Common in the Hamilton beds of New York
and Michigan.

XXXVII. MicHetinta De Koninck.

Convex or hemispheric heads consisting of
prismatic corallites and basally covered with
a wrinkled peritheca. Septa represented
by longitudinal ridges. Tabule numerous, crowded and convex
upward, often incomplete and uniting. Mural pores numerous,
irregularly scattered. Differs from Favosztes in the greater diam-
eter of the corallites, in the crowded arched tabulz and in the
-numerous irregularly scattered mural pores. Dev.—Carb.

Fic. 143. Pleuro-
dictyum stylopora.

100. M. convexa (d’Orbigny). (Fig. 144.) Devonic.
Calices 8 to 10 mm. in diameter. Tabulz thin, very close,
strongly arched in the center, vesicular at the base.
In the Onondaga limestone of Canada, Michigan and the Falls
of the Ohio region.

101. M. cylindrica (Michelin). Devonic.
Corallites subcylindrical ; on the interior are regular annulations

9O WORTH AMERICAN INDEX FOSSILS.

which occupy the same level in the adjoining tubes. Principal
tabule numerous, slightly arched, uniting with the incomplete one.
In the Onondaga limestone of Michigan, Ohio and Kentucky, etc.

Fic. 144. Michelinia convexa (after Billings).

102. M. favositoidea Billings. Devonic.
Calices 4-6 mm. in diameter ; tabulz horizontal, pores numerous,
crowded. (Forms transition type to /avoszdes.)
In the Onondaga limestone in
New York, Canada, and the Falls
of the Ohio.

XXXVIII. Cuonostecites FE. & H.

Coral heads composed of cylindrical
tubes, either closely adjoining or
distinct and expanding at regular
intervals into connecting horizontal
plates, which are pierced by canal-
like pores. Tabule as in MUtchelinia,
septa represented by rows of spinules
New buds arise from the connecting plates. Devonic.

Fic. 145. Chonostegites ordina-
tus (after Billings).

103. ©. clappi E.. & H. Devonic.
Tubes 5 mm. or more in diameter, connecting plates crowded,
giving the whole a very compact appearance.
In the Onondaga limestone of western New York, Ontario, and.
Falls of the Ohio.

ANTHOZOA

TABULATA. QI

104. C. ordinatus (Billings). (Fig. 145.) Devonic.
Tubes smaller and more distant and plates more widely sep-

arated than in preceding. Whole aspect more loosely aggregated.
In the Onondaga beds of western New York and Canada.

XAALA, THECIA EB. & FH:

Generally massive corals composed of prismatic thick-walled
tubes with funnel-form calices. Base with a wrinkled peritheca.
Septa 12, strong, uniting in ad-
joining calices across the in-
tervening space. Tabule and
mural pores as in Favosttes.
Sil.—Dev.

105: T. major Kom.- . (Fig.
146.) Siluric.
Corallites 2 mm. in diameter;

septa extend half way to center,

their edges with two rows of
granulose spinules.
In the Niagara beds of Michigan, Tennessee, the Falls of the

Ohio and other regions.

106. T. minor Rom. (Fig. 147.) (Z. Swinderana ? (Goldf.).)

Siluric.

Tubes about I mm. in diameter, otherwise similar to the pre-
ceding. Occurs with the preceding.

107. T. ramosa Rom. Devonic.
Branching, cylindrical stems from half an inch to two inches in
diameter. Calices unequal from I to 2 mm. in diameter.
In the Onondaga beds of Michigan and the

Falls of the Ohio. oe

XL. ALVEOLITES Lamarck.
Fic. 147.: Thecia

Massive or arborescent coralla. Tubesthin- ,,,.. (enlarged).

walled, closely appressed, the calices oblique,
compressed, triangular or crescentic. Septa rudimentary. Tabule
complete; mural pores large but irregularly disposed. Sil.—

Dev.

108. A. niagarensis Rominger. Siluric.
Hemispheric masses of concentric laminz, with epitheca on

92 NORTH AMERICAN INDEX FOSSILS.

lower side. The large marginal pores cause a pouch-like dilation
of the tube-wall.
In the Niagara group of Michigan and the falls of the Ohio.

109. A. squamosus Billings. Devonic.

Differs from the preceding in the greater horizontal expansion
(5-6 in.) as compared with the thickness (I in.) also in the great
obliquity of the apertures, and in the absence of the pouch-like
protuberances. Septal spines present. Greatest diameter of tubes
5 to Imm.

In the Onondaga formation of New York, Canada, Michigan,
Ohio, Kentucky, etc.

110. A. goldfussi Billings. Devonic.
Flattened or disk-like expansions like the preceding with a basal
epitheca. Tubes larger (1.5 to 2 mm.), oblique and in various
stages of compressions in the same specimen.
In the Hamilton group of New York, Canada, Michigan, Iowa
and in strata of similar age near Louisville, Ky.

XLI. CLADOPORA.

Coral composed of branching stems or flattened expansions,
with thick-walled elongate, conical tubes, opening oblique to the
surface, with dilated orifices. Mural pores and occasional tabulae
present. Sil.—Dev.

FLATTENED EXPANDED SPECIES.

111. C. laqueata Rominger. Siluric.
Expansions. composed of round or compressed elliptical stems
from two to four millimeters in diameter and uniting repeatedly so
as to form a coarse network. Orifices of tubes distant with a
strong lip, oval, transverse to the branches, width nearly a milli-
Meter.
In the Niagara group of Michigan and at the falls of the Ohio.

112. C. lichenoides Rominger. Devonic.
Irregular expansions with peritheca on the under side. Tubes
flattened, extending outward, prostrate but bending upward at the
ends. Orifices oblique or at times nearly at right angles to the
tube, and polygonal.
In the Onondaga beds of New York, Canada, Michigan and the
Falls of the Ohio.

ANTHOZOA—TABULATA. 93

113. C, fisheri Billings. Devonic.
Flat leaf-like expansions attached at one point to foreign bodies,

and with oblique orifices on both sides.
In the Onondaga(?) beds of Kentucky and Indiana and in the

Hamilton group of Canada, etc.

RouND STEMMED SPECIES.

114. C. seriata Hall. (Fig. 148.) Siluric.

SIMs se :
toads eore |

Fic. 148. Cladopora seriata (N. Y. St. Geol. Surv.).

Nearly parallel crowded branches, forming a glomerate mass,
the branches sometimes bifurcating. Calices in ee series

with projecting circular lip.
In the Niagara group of New York, Canada, etc.

115. C. cryptodens (Billings). (Fig. 149.) Devonic.
Cylindrical bifurcating branches from five to ten millimeters in

Fic. 149. Cladopora cryptodens (af- Fic. 150, a-b. Cladopora labiosa (after
ter Billings). Billings).

diameter. Tubes with oblique dilated orifices from 1 to 1 "mm,
in diameter.

94 NORTH AMERICAN INDEX FOSSILS.

In the Onondaga beds of New York, Canada, Michigan, and
Western States.

116. C. labiosa (Billings). (Fig. 150, a-0.) Devonic.
Stems smaller dnd more frequently branching, often reuniting.
Oblique (2 to 5 mm. in diameter) subcircular orifices with a promi-
nent convex lip.
Abundant in the Onondaga of New York, Canada, Michigan and
the Falls of the Ohio. |

117. €. roemeri (Billings). Devonic.
Cylindrical or compressed stems, about 5 mm. or less in diame-
ter with large oblique orifices, which merge into an indefinite in-
terstitial surface or into angular pits.
In the Hamilton group of Canada and at the Falls of the Ohio.

118. C. pulchra Rominger. Devonic.
Similar to preceding but with circular orifices, more than a tube-
diameter apart, and often at the summit of a small elevation.
In the Onondaga of Canada, Michigan and the Falls of the Ohio.

119. C. robusta Rominger. Devonic.
Large compressed cylindrical stems from 10 to 20 mm. thick
and often forming net-like expansions covering several square feet.
Oblique orifices with strong semicircular lips.
In the Onondaga beds of Michigan and the Falls of the Ohio,
and in the Hamilton of Michigan.

XLII. Srria‘ropora Hall.

Coral stock of simple dividing cylindrical branches, with thick-
walled corallites, opening in rounded apertures, which are sur-
rounded by polygonal depressed calices, the sides of which are
striated by rudimentary septa. Occasional septal spines, tabulz
and mural pores present. Sil._Dev.

120. S. flexuosa Hall. (Fig. 151.) Siluric.
Bifurcating branches. Polygonal expansion of cells deep, and
bounded by angular ridges, vertically striate, the striz becoming
fainter upward. Calices circular at the base.
In the Niagara beds of New York, etc.

121. S. linneana Billings. Devonic.
Orifices of unequal size through intercalation of smaller ones,
moderately oblique, 2 mm. in diameter and narrowing in diameter.

ANTHOZOA—TABULATA. 95

Twelve radial furrows, not always preserved in fossilization, mark
the orifices and between them are rows of spinules.

In the Hamilton group of Canada and Michigan and in Devonic
beds of somewhat earlier age at the Falls of the Ohio.

a tii .
et Oe i et. ‘4 1
& we igeey Sey

: AN

ue: ’

Fic. 151. Striatopora flexuosa (N. Y. Geol. Surv. ).

XLII. Tracuypora E. & H.

Corallum consisting of branching cylindrical stems, which are
made up of polygonal corallites with very thick walls, and circular
calices, which are superficially far apart. Scattered mural pores,
remote tabule, and rows of spines
representing the septa, are charac-
teristic! Dev.

122. T. ornata Rom. (Fig. 152.)
| Devonic.
Stems 10 to -O mm. in diameter,
orifices circular or oval, generally
slightly elevated, irregularly dis-
persed, the interspaces wider than
the diameter of orifice, which is
about 1144 mm. Granules and short
radial ridges surround the orifices.
Common in the Hamilton group
of New York, also more rarely in
Canada and Michigan.

Fic. 152. Yrachypora ornata (=

T. limbata Hall) (Pal., N.Y.). 123+ 4. elegantula Billings.

Devonic.
Stems 2 to 5 mm. in diameter, orifices in four rows, oval and
partly edged by an elevated rim.
Hamilton group of Michigan and Canada.

96 NORTH AMERICAN INDEX FOSSILS.

XLIV. Hatysites Fisher.

Corallum composed of cylindrical or compressed corallites, which
are joined into intersecting and anastomosing laminz of single
layers of tubes united along the whole of their adjoining side.

Fic. 153. Halysites catenulatus (N. Y. Geol. Surv. ).

The tubes are covered by a continuous peritheca on their free
sides. No mural pores; tabulz well developed; septa obsolete or
in cyclesof 12. Ord.—Sil.

124. H. catenulatus (Linn.). (Fig. 153.) (Ord.) to Siluric.

Tubes oval in section united by their narrower sides, or with a
minute closely tabulate tube intervening.
Epitheca with fine and occasionally coarse
lines of growth; meshes formed by tubes,
large, irregular and varying in size.

In the Ordovicic beds of Anticosti, Wiscon-
sin, Colorado, but especially in the Middle Silu-
ric of Europe and North America generally.

Octameral Corals.
SUN, weet EB, & eo.

Coral head consisting of numerous cylin- Fic. 154. Zyellia am-
drical tubes, growing parallel and united by ¢7ena, vertical and
vesicular coenenchyma, septa 12, short, tabulae "*sverse Sections en-
: Ae} ies Taka , 3 larged (after Lambe).
irregular. Siluric. .

125. L. americana E.& H. (Figs. 154-155.) Siluric.

Tubes 11% to 2 mm. in diameter, separated by two tube-diam-
eters or something less. Septa comparatively short, coenenchyma
of fine cysts.

ANTHOZOA—OCTOCORALLA. 97

In the Niagara group of Michigan, Iowa and the Falls of the
Ohio. Also at Anticosti.

XLVI. HELIoLires Guettard.

Corallum compound, varying from spheroidal to flabellate, with
large cylindrical macrocorallites, furnished with twelve infoldings
of the wall, or pseudosepta, and numerous angular microcorallites

Fic. 155. Lyellia americana (Ind. Geol. Surv.).

investing the larger ones. “Tabulz in both corallites, more numer-
ous in the smaller. No mural pores. Basal peritheca present.

Ord.?_-Dev.

126. H. megastoma McCoy. Siluric.
Convex heads with the macrocorallites about 2 mm. in diameter
and distant somewhat less. Twelve very short pseudosepta. Form
subglobular.
In the Niagara group of New York, Canada, Michigan, Iowa,
Wisconsin, etc.
127. H. interstinctus Linn. (Figs. 156, 158, a, 0.) Siluric.
Discoid or in Jeaf-like expansions with a basal peritheca. Macro-

Fic. 156. eliolites interstinctus, with part of surface enlarged (after Roemer.) 5S

98 NORTH AMERICAN INDEX FOSSILS.

corallites slightly larger than in preceding, and somewhat more
distant. Pseudosepta nearly reaching the center in well-preserved
specimens. Microcorallites polygonal.

Fic. 157. L7eliolites elegans (N. Y. Geol. Surv.).

In the Niagara group of Michigan, Indiana, Kentucky, Ten-
nessee, etc. |
128. H. elegans Hall. (Fig. 157.) Siluric.

Hemispheric coralla with macrocorallites a little over .5 mm. in
diameter, and pseudosepta in the form of
oblique spines and reaching half way to the
center. Microcorallites crowded, minute.

In the Niagara group of New York,
Michigan, Indiana, Kentucky, etc.

XLVII. Prasmopora E. & H.

Differs from /Zefolites in having twelve yyg. 158 «6. Helio-
well-developed vertical rows of spinulose JZites interstinctus; c, d,
pseudosepta and ccenenchyma composed of //asmopora follis,vertical —
intersecting plates which however formno true ™¢_ horizontal. sections

; : enlarged (after Lambe).
microcorallites, and whose tabula become
more or less continuous, producing a vesicular tissue. Ord ?—Dev.

12G; P<itollis EST." (Fig: 159,.4, 22) Salar:
Tubes from I to I.5 mm. in diameter with circular crenulated

ANTHOZOA—HEXACORALLA. 99

orifices, and separated by an equal width. Growth in pyriform or
subcylindrical club-shaped masses, with a rudimentary peritheca
at the conical base.

In the Niagara beds of Michigan — more commonly in the same
beds of Indiana, Kentucky and Tennessee.

ALVUE Terrapin Dana.

Massive heads composed of numerous long, slender, prismatic
and thin-walled corallites, quadrangular or petaloid in section and
with four primary septa and numerous
» tabula. Increases by fission. Ordo-
ZW vicic.

T. fibratum Safford. (Figs. 159, 160.)

Ordovicic.
Septa nearly reaching center; diameter
of corallites 0.04 inch.

In Stones River and Black River of
New York, Canada, Tennessee and other localities.

Fic. 159. Zetradium fibratum.

Hexameral Corals.
XLIX. ParasMytia E. & H.

Cylindrical or conical, simple corals with a scar of attachment at
the base. Calyx circular, with granular septa and a spongy colu
mella. Epitheca absent or rudimentary, and
costz strong. Cretacic.

130. P. austinensis Roem. Cretacic.

Top-shaped coral attached by a broad Fic. 160. 7etradium
base, above which it is contracted, strong “%¢ratum, cross-section
equal costz. Calyx slightly compressed with a Sir
septa in four cycles.

In the Edwards limestone (Lower Cretacic) of Texas.

131. P. texana Vaughan. (Fig. 161.) Cretacic.

Differs from the preceding in having cost alternating large and

small.
In the Buda limestone (Lower Cretacic of Shoal Creek, Texas).

L. PxLeurocora E. & H.

Branching cylindrical corals with a thick compact wall without
epitheca. Columella of numerous points (papillose); septa granu-
lar, projecting above the calyx. Coste distinctly wavy. Cretacic.

100 NORTH AMERICAN INDEX FOSSILS.

132. P. coalescens Roem. Cretacic.
Slender cylindrical, much branching corals with calices 3 mm. in
diameter — septa not reaching to center, which is occupied by
spongy columella.
In the Edwards limestone (Lower Cretacic) of Texas.

Fic. 161. Parasmylia texana (Vaughan, Bull. U. S. G. S.).

ik Cuapveravinia F.& ee

Branching corals with cylindrical stems multiplying by fission.
Calices circular with a rudimentary columella or none; a well-de-
veloped epitheca is present. Cret.Recent.

133. C. furcifera Roem. (Fig. 162.) Cretacic.
Calices 4 to6mm.in diameter. No columella, septa in 3 cycles.
Growth a regular forking, with uniform
branches. Epitheca concentrically wrinkled.
In the Edwards limestone (Lower Cretacic)

of Texas. Fic. 162. Cladophyl-
lia furctfera, section of

LILI. Seprastr#aA d’Orbigny. Be

Compound corals, with corallites pris-
matic from crowding. Calices of moderate depth with simple septa,

Fic. 163. Septastrea marvlandica (Md. Geol. Surv.) reduced.

ANTHOZOA—HEX ACORALLA. IOI

the longer of which unite in the center, where they often form a
pseudocolumella. No true columella or pali occur. Tertiary.

134. S. marylandica (Conrad). (Fig. 163.) Miocenic.

Compressed stems with short, rounded branches, or large
flattened lobate or digitiform expansions. Corallites averaging
5 or 6 mm. in diameter. Twelve large and a similar number of
smaller septa occur ; sometimes a third series.

Abundant in the St. Mary’s Miocene
formations of various parts of the Atlantic
coast.

LIII. FLAsettum Lesson.’

Simple wedge-shaped compressed corals
free or attached, with numerous septa, and
a compressed columella. A wrinkled epi-
theca sometimes with spinous processes
occurs. Tert.—Recent.

135. F. cuneiforme Lonsdale. (Fig. 164.)

Eocenic to Oligocenic.

Base with a short prolongation of attach-
ment; exterior of compressed wedge-
shaped structure marked by strong ridges
or costz which are largest in the middle.
First three cycles of septa form the colu-
mella by fusion of their inner margins.
Claibornian, Jacksonian and Vicksburg-
ian groups of South Carolina, Alabama,
Mississippi, Louisiana,Arkansas and Texas.
Several distinct varieties are recognized.

Fic. 164. Hiabellum cune-

iforme, two varieties, with LIV. PLatytrocuus Milne-Edwards &
calyx of /. Jlerchi (after Haime

Vaughan, Mon. U.S.G. S.).
Simple cuneiform corals, with a colu-

mella formed of the fused inner edges of the septa. Externally
the septa are represented by thick costz, while within the outer
walltheir margins are carinated. Tertiary.

136. P. stokesi(Lea). (Fig. 165.) Eocenic.
Small, with the base drawn out into a wedge nearly as wide as
the coral above. Septa and costz 24, nine of which on the mid-

102 NORTH AMERICAN INDEX FOSSILS,

dle of each broad face, converge and unite downward, while those
on either side become broader. Surface rough with granules.
Columella papillose.

In the Claibornian group of South Carolina, Alabama, Missis-
sippi and Texas.

LV. Discotrocuus Milne-Edwards & Haime.

Free, disk-like corals, with a flat base and slightly arched upper
surface. Septa carinate, radial, the longer joining the papillose
columella. Costz simple. Tertiary.

137. D. orbignianus E.& H. (Fig. 166.) Eocenic.

Base with the large unequal costze becoming indistinct near the
concave center. Diameter 6 mm., height 1.5 mm.

Fic.165. Platytrochus stokesi (after Fic. 166. Dz¢scotrochus orbignianus,
Vaughan, enlarged). with partial enlargement (after Vaughan).

In the Lower Claibornian of Alabama, Mississippi, Louisiana
and Texas.
LVI. Tursinoria Lamarck.

Small, free, conical corals with a circular calyx. Septa prolonged
externally into strong costze. Septa in several cycles. Alternate
septa triple from union with smaller ones,
columella well developed. Tert.—Recent.

138. T. pharetra Lea. (Fig. 167.) Eocenic.

Twenty-four rounded and prominent coste,
with entire margins, twelve of which become
larger basally and only six occurring at the
base. A double row of pores occurs in the
furrows between the coste. Columella
slightly projecting in the form of a star, with
six rays, each of which fuses with a principal
septum.

Fic. 167. Turbinoha
pharetra (after Vaugh-
an, enlarged).

'
a
-

ANTHOZOA—HEXACORALLA. 103

In the Clatbornian and Jacksonian groups of Alabama, Missis-
sippi, Louisiana and Texas.

LVI. -Ocutina’ Lamarck.

Composite corals generally in the form of branching stems with
the calices spirally distributed over the stem, generally on crater-

Fic. 168. Oculina Fic. 169. Oculina
vicksburgensis. misstssippiensts.
(After Vaughan, Mon. U. S. G. S.)

like elevations and separated by dense layers of ccenenchyma.
Septa in several cycles, the longer reaching the center which is
occupied by a papillose columella surrounded by a cycle of vertical
rods or pali. Jert—Recent.

139. O. vicksburgensis (Conrad). (Fig. 168.) Oligocenic,
Branches 20 to 30 mm. in thickness. Circular calices separated
by once or twice their diameters or more, shallow, but often with a
prominent margin. Feeble flexous striz radiate from the calices
on the ccenenchyma. Diameter of adult calyx averaging 4 mm.
In the Vicksburgian and Red Bluff beds of Mississippi.
140. Q. mississippiensis (Conrad). (Fig. 169.) Oligocenic.
Calices strongly projecting, crowded, with thin septa. Costal
strize faint or obsolete.
In the Vicksburgian group of Mississippi.

104 NORTH AMERICAN INDEX FOSSILS.

LVIII. Astrouertia E. & H.

Similar to Ocudzna, but with the calices merely excavated, rarely
raised on crater-like elevations. Columella spongy. Tertiary.

Fic. 170. Astroh: lia palmata (Md. Geol. Survey) reduced.

141. A. palmata (Goldfuss). (Fig. 170.) Miocenic.

Branching, often coalescing, or in palmate expansions. Calices
circular, excavated, septa in three cycles, the first and second
reaching the columella.

In the Choptank and Calvert formations of the Miocene of the
Atlantic coast.

LIX. BALANoOPHYLLIA Wood.

Simple conical corals with a broad base of fixation. Septa very
numerous, closely crowded and partly fused together. Columella
spongy. Epitheca often present, structure porous. Eocenic—
Recent.

142. B. desmophyllum E.& H. (Fig. 172.) Eocenic.

Basal portions cylindrical, becoming conical upwards. Section
elongate, elliptical with rather deep calyx. Septa thin, coste fine.
Epitheca rudimentary or absent.

In the Chickasawan and Claibornian beds of Alabama, Mis-
sissippi, Texas and in Maryland.

143. B. irrorata (Conrad). (Fig. 171.) Eocenic.

Slender cylindro-conical, curved, cross-section elliptical, epitheca
on basal portion.

a ae

ANTHOZOA—HEXACORALLA. 105

In the Claibornian and Jacksonian beds of Alabama, Louisiana
and Mississippi. Varieties also found in Texas.

Sea ten OF
a * Vit I= Pr
: Sa 1
a)

Fig. 171. Balanophyllia trrorata with enlargement of calyx (Vaughan).

144. B. haleana (E. & H.). (Fig. 173.) Eocenic.
Conical, slightly curved, broadly elliptical in sections, basally at-

Fic. 172. Balanophylia Fic.173. Balanophyllia Fic. 174. ELupsammia
desmophylium. haleana. elaborata,
(After Vaughan. )

tached. Costz dividing upwards. Septa crowded, extremely thin,
with granulated surfaces. Columella large, spongy but dense.

Basal epitheca present.
Common in the Chickasawan of Alabama.

LX. EupPSsAMMIA EB. & 5H:

Like Balanophylia, but acutely pointed and free. Septa of the
last cycle stouter than the rest. Columella present or absent.

106 NORTH AMERICAN INDEX FOSSILS.

145. E. elaborata (Conrad). (Fig. 174.) Eocenic.
Conical with elliptical section; finely perforated, costz trifur-
cating upwards. No epitheca. Spongy columella, and thin anas-

tomosing septa; wall spongy.
In the Chickasawan beds of Maryland, Virginia and Alabama.

LXI. Enpopacnus Lonsdale.

Corals with the general form of Flade/lum, but with the porous
wall structure and septal arrangement of Euzpsammuia. Lateral wings
often developed. A compressed spongy columella occurs. Tertiary.

146. E. maclurii (Lea). (Fig. 175.) Eocenic.
Cuneate, with subparallel margins, sides and ends rounded.

nT n ESE, UAE >
EARS LY OCT MRL :

Fic. 175. LEndopachus maclurii (after Vaughan).

Lateral wings well developed. Columella narrow and elongate in

long axis of corallum; very vesiculate.
In the Claibornian and Jacksonian beds of Alabama, Mississippi,

Louisiana and Texas.

BRYOZOA. 107

Puytum IV. MOLLUSCOIDEA.

Class Bryozoa (Polyzoa). *

The Bryozoa or Polyzoa are marine or fresh-water animals
almost always occurring in colonies, known as zoaria, which in-
crease by gemmation. Each good of the colony is enclosed in a
membranaceous or calcareous double-walled sac, the zowcium, into
which it can withdraw (Fig. 176@). The animal possesses a mouth,
an alimentary canal, and an anal
opening,and, in addition to these,
a fringe of respiratory tentacles
—the lophophore (Fig. 1764).
The colony is commonly attached
to foreign bodies, which it either
encrusts or from which it arises
as an independent frond. The

Fic. 1762. Membranipora pilosai(re- frond may be unilaminar, 2 e.
cent). Two zooids, one expanded and wjth the cells opening on one
‘e ppc withdrawn into the transparent zo- side only. It may be encrusting
-ecium. Enlarged. (After Farre. ) ; : ;

or lined with a basal epitheca.
When the ends of such a unilaminar frond unite, a hollow
tube lined with epitheca is produced. Again the frond may be
bilaminar or bifoliate, with the epithecz of the two parts growing
together, forming a mesotheca. ‘This often contains median tubuls.
Other forms are massy (hemispheric, globular, or discoidal in
shape) with gemmation on all sides; vamose or branching and
dendroid.

A network is often formed, when the branches grow together,
leaving fenestrules along the border of which are found the apertures
of the cells. The branches, instead of anastomosing, may be
straight and united at intervals by cross-bars or dssepiments
_ which commonly have no apertures (Fenestella, etc.). The branches
_ may be ornamented by nodules, spines or a longitudinal £ee/ or
carina; this latter may be sharp, expand, or even bear a com-
plicated superstructure. In some types (Archimedes) these fronds

* Thin sections are required in the study of this class.

108 NORTH AMERICAN INDEX FOSSILS.

are twisted in a spiral form, of which generally the solid axis alone
is fully preserved in fossil form.

In the Paleozoic genera the cell apertures are often surrounded
by elevated rims or feristomes. Often a portion of the poste-
rior wall is more or less thickened
and curved toa shorter radius, form-
ing /unaria, the ends of which may
project into the tube as pseudosepta.
At the junction of the apertures
small cylindrical tubules projecting
above as spines, the acanthopores, of-
ten occur. When the zocecial tubes
are crowded and thin-walled their
apertures generally have an angular
outline, but when they are _ thick-
walled or separated by interspaces,
they are circular, oval or variously
. formed. ‘The interspaces may be oc- Fic. 1766, Diagram showing
cupied by smaller tubes, the 7eso- structure of single bryozoon zooid.
pores, or by vesicular tissue. The (After Busk.) a, anus; ¢, ectocyst;
mesopores may be scattered or gath- i, pergaste Spa.) 2

: ; lion ; 2, intestine ; 7, lophophore ;
ered into clusters. Elevations or ,, month; », ovary; 4) eeepmee
moniticules and flattened or depressed gus; ov, aperture of the zocecium ;
spots or maculae are other charac- ” ‘etractor muscles; s, stomach ;
teristic surface features. They may % ‘mtacless 2 tentacular sheath ;
be solid or contain the openings of
zocecia (generally somewhat larger than the ordinary) or of
mesopores.

In the Cryptostomata the opening of the zocecium is the cell
orifice. Above this occurs a tubular shaft formed by the thicken-
ing of the surface of the zoarium for strengthening or protective
purposes. This shaft is the vestibule, and its aperture is variously
formed. —

In most Palzeozoic Bryozoa the tubes are variously divided by
cross plates or diaphragms which in some types are vesicular, form-
ing cystiphragms (Trepostomata). The diaphragms may be com-
plete or pierced by a central opening. In the Cryptostomata addi-
tional plates the /emisepta project from the wall into the cavity.
When they project from the posterior wall, they are known as

superior hemisepta, when they project from the anterior wall they

x, testis; z, funiculus.

°

BRY OZQd. 109

are the zuferior hemisepta. In the Chilostomata the wall is fre-
q quently only partly calcified and hence in fossil forms the cell

opening is very large. Additional pores the aviculania are com-
_ monly found.

LITERATURE,

General Reference.

1900. Nickles, John M., and Bassler, Ray S. A synopsis of
American Fossil Bryozoa including Bibliography and Synonymy.
Bull. 173, U. S. Geol. Survey. This work is indispensable to the stu-
dent of Bryozoa. It contains complete references to literature, to date
of publicati n, generic descriptions and a bibliography of all described
American Palzeozoic species.

Pal@ozotc.

- 1847, 1852. Hall, James. Paleontology of New York, Vols. I. ard
II. Contains Bryozoa of the Ordovicic and Siluric of New York. |
1876-79. Hall, James. Fauna of the Niagara Group in central Indi-
ana. 28th Ann. Rep. N. Y. State Museum of Natural History ;
_ Trans. A:bany Inst., X., 1883...
1879. Nicholson, H. Alleyne. On the structure and affinities of the
__ _Tabulate Corals of the Paleozoic period. Edinburgh.
1881. Nicholson, H. A. On the structure acd affinities of the genus
~ Monticulipora, etc. Edinburgh.
_ 1882-1884. Ulrich, E. O. American Palzozoic Bryozoa. Journ.
Seeemcin. Soc. Nat. Hist., V., VI., VII.
1887. Hall, James. Fenestellidze of the Hamilton group of N. Y.
_ 6th Ann. Rep. State Geologist of N. Y., pp. 43-70, pls. i.—vii.
_ 1887. Hall, James, and Simpson, Geo. B. Palxont. of N. Y. VI.,
Corals and Bryozoa. (Lower and Upper Helderberg, and Hamilton.)
E. 1888. Hall, James. Fenestellidz of the Lower Helderberg. Rep.
state Geol. of N. Y. for 1887. 41st Ann. Rep. N. Y. State Mus,
Nat. Hist.
1890. Ulrich, E.O. Palzozoic Bryoz a. Geol. Surv. of Ill., VIII.,
. pp. 285-688, pls. XXIX.-LXXVIII.
1891. Hall, James. Continuation of descriptions of Bryozoa not
printed in Vol. VI. Pal. of N. Y. 44th Ann. Rep. N. Y. State Mus.
Nat. Hist., pp 67-87.
. 1893. Ulrich, E. O. Lower Silurian Bryozoa of Minnesota. Geol. -
meeominn., Iif., Pt. I., pp. 96-332, pls. i.—xxviii.
1897. Simpson, George B. Handbook of genera of North American
Palzeozoic Bryozoa. 14th Ann. Rep. State Geologist N. Y. for 1894,
pp. 407-608, pls. A-E, i.—xxv.

I1O NORTH AMERICAN INDEX FOSSILS.

1904 to date. Ulrich, E. O., and Bassler, R. S. A revision of
the Palzeozoic Bryozoa. Pt. I., Ctenostomata ; Smithsonian Miscell.
Coll. Vol. 45; 256-294, pls. 65-68, 1904; Pt. II. Trepostomata,
tbid., vol. 47, pp. 15-55, pls. 6-14, 1904.

1905. Nickles, John M. The Upper Ordovician Rocks of Kentucky
and their Bryozoa. Kentucky Geological Survey Bulletin 5.

1906. Bassler, Ray S. The bryozoan Fauna of the Rochester Shale,
Bull. 292, U. S. Geol. Survey.

Mesozoic and Cenozotc.

1845. Lonsdale, William. Polyparia from Timber Creek, N. J.
Quar. Jour. Geol. Soc. London, I., pp. 65-75. Corals from Tertiary
of North America. Jézd., pp. 495-509. Polyparia from the Eocene
Tertiary of N. Amer. /é7d., pp. 509-533.

1860. Gabb, W.M., and Horn, G. H. Cretaceous corals from
New Jersey. Proc. Acad. Nat. Sci. Phila., XII., pp. 366-367. New
species of American Tertiary and Cretaceous fossils. Jour. Acad. Nat.
Sci. Phila: -ser.2)1V 3 pp. 375-404:

1862. Gabb, W. M. and Horn, G. H. Monograph of fossil Poly-
zoa of the Secondary and Tertiary of N. Amer. Jour. Acad. Nat. Sci.
Phila:,ser,-2,. V5, ‘pp: 112-178; pis, Mixxx,

1890. Gregorio, Antonio de. Monographie de la Faune Eocenique
de |’Alabama et surtout de celle de Claiborne de l’Etage Parisien.
Ann. Géol. et Paléont., Livraisons VII., VIII. Palermo.

ARTIFICIAL KEY TO GENERA.

I. CTENOSTOMATA. — Zocecia horny or membranaceous, isolated, budding from
internodes of tubular stolon ; sometimes appearing as excavation in the host... A.

A. Thread-like, or'very slightly swollen in center..,........ic..2200» seoms<4eeaeeeeee ea

* Wrrengement. net-like Or pimMMGte?, i. 6.25 <0 vengst peancsicotess I. Rhopalonaria.

* Arrangement more of less ‘tadial 202.01.) «ssss0cv eseoatens’ eae ceuee Ill. Vinella.

A. Swollen, bulb or sausage-like |, .ias020s3 ccssaes ce tssenexoheete ese besiaenhe eee nn ae

am A crancement ims linGat Semmes. 5,04. nce docskbelen satus ear IV. Allonema.

** Arrangement radial, at intervals along slender stolon..... II. Ascodictyon.

Il. CYCLOSTOMATA. — Zocecia simple calcareous tubes, usually without transverse

partitions, singly lor I ASSOCIATION sf .iecedcacee. oss lade tea aee aka eoeee POPE) on B.
B. Zocecia free throughout in loosely united branches or strings................. WEE

*** Tubes in linear series, budding one from the other uniserially........... I.

1. Dichotomously branching, apertures subterminal..... V. Stomatopora.

1. Irregular branching, apertures terminal............... eee. X. Hernodia.

*** Tubes budding on two or more sides from a linear median stolon ..... 2:

2. Branching; tubes separate and distinct.................. IX. Hederella.

2. Branching ; tubes closely parallel in contact, and of uniform length.
XI. Reptaria.

B. Zocecia united wholly or partly in bundles of two or more ; no interstitial cells.
HKRK

BRYOZOA. III

*¥*%* Zocecia few in conical bundles of two'or MOFE,....... seececessesceesseeee 3:
3. Subterminal apertures not elevated ................. XIII. Phacelopora.
3. Terminal apertures, elevated at right angles to axis of branch, fre-
quently tree: picccthcanssoum onan cg ee Sere ooh see XCVIII. Filifascigera.

BA EX. ZCI: MUMMETOUS. -hn578s co Stir dean aca Soe hae eae eae sae cee coe le aR 4.
4. Zoarium a more or less flattened expansion or attached stem........ a.

a. Of flattened attached stems sometimes widening or uniting into
sheets, tubes slightly or not at all projecting.. VI. Prodboscina.

a. Spreading fronds, with ends of tubes projecting................. aa.
gy Mey BUDS fee cote alunite Lely pein tn VIII. Déiastoporina.

aa. Attached, tubes on one side only........... VII. Berenicea.

a. Obconical or cup-shaped, attached by center of sides with epi-
theca, tubes not projecting ......... omanease 8 XCIX. Discosparsa.

4. Zoarium a branching cylindrical stem with more or less freely pro-
jebteem tebecemas: sa. apis bites qcatduhiodions rs isha ccetyanbiaetest b,

b. Tubes regular, distant, generally much exserted.. XII. Wrtoclema.
6. Tubes crowded slightly exserted, branches hollow, cavity divided

by transverse ‘partitions... ..g.sny0. sense eggewny C. Cavaria.

B. Zocecia in compound zoaria, with interstitial cells or mesopores.. ........... ie
) 5* Walls of adjoining zocecia thoroughly amalgamated and pierced by numer-
IES IRS TOO) IRIN NG ee ite dtc oe ath A reaivs sn boeictea denen Rowen as tame tee 5

5. Variously formed generally massy with basal epitheca, and uniform

SMR OIN A DOCLMTER fosrinet siwaceverinadatee veal sabuagucinsee cay CI. Certopora.

5. Massy or branching, numerous mesopores or interstitial cells between

HIRE ZORRO ea Oe hat avin pia ed nate ahs raedvayis CII. Heteropora.

5. Of hollow branches the cavity divided by transverse plates; surface

with toacules And MMESOPOLES sc) ss f0sksbas vs cad cewenenseabee C. Cavaria.

5* Walls minutely porous, lunarium present, often very prominent, surface
rire: mineiiis ‘or MONtenles 3/5 Wiis. eh saw aeapap digs tobias ¥atha sd See son omeue cee « 6.

BPE ACT OMIDG fo boo tnt ook cia Eacunisu caverns ionawes dna aibee domeus dees nas abv 7

ps Ie OGG CR OAM SHOE. 3.5 /y5 ei sbe saucer had +0 Gaines savcloodcaasnabsise ae bb.

Bot ESO POLES ADUNMARE Weed tacsck tahatnesnaesbanees pale ne aoeend Ii.

zz. Lunarium forming pronounced hood.
XV. Ceramoporella.
zz. Lunarium not hooded, interspaces with vesicles.

fistulipora.
BO GEO POEs he We ate da noyevidin Deivavsie tna von e4) Seas egeasb ey 22.
22; | Mesoporesscatteredss5..vvcc..03. XVIII. Anolotichia,

22. Mesopores mostly in macule.......... XVI.. Crepipora.
c. Disc-shaped, apertures in radiating ridges... XXV. Botryllopora.

Dee RAM aR is OUR: BRASIL 52 ry atk, a ea uaa n ae ce txe 60) Sniwaned on eae pas Juunnss d.
@. Mesopores few, decreasing toward margin... . XIV. Ceramopora.
ff, PCEADONES TOMCR OUT 3 7, Freaks vinedckde buted + ch cnewedacavanpreddtehesas re

£6, LAAT WEN TAISEN eso dus would owwandh hea XX. Bythotrypa.

cc. Lunarium moderate, interspaces with vesicles.
XXI. Fistulipora,
cc. Lunarium a strong bidentate process, interspaces with
ERNE Bh, irarehasswNigrins «esis ances . XXIII. Buskopora.
SO; pranemne, more of less cylindrical. seisies in idesccescacssaverencivesyons é.
é. Branches hollow, lined on inside with epitheca, lunarium hooded.
XVII. Coeloclema.,

112 NORTH AMERICAN INDEX FOSSILS.

e. Branches hollow, with irregularly expanding and contracting axial
tube ; diaphragms few or absent, interspaces with vesicles.
XXII. Chilotrypa.

e. Branches solid ; diaphragms present.............. XVI. Crepipora.
G; -Zaarimn beloliate ss) S314. 2. 20k cc haat ss hats os vad Cola ca -
f. Lunarium prominent, hood like.............. XIX. Ceramophylla,

y. Lunarium not prominent, interspaces with vesicles.
XXIV. Meekopora.
III. TREPOSTOMATA. Zoaria compound, with walls of zocecia thickened in the
outer region with numerous diaphragms or cystiphragms, and monticules or mac-

ulz.on surface. Tubes separating upon fracture... ... 0.2.00. c.<..0cscisceensccetiane Gs
c. Cystiphragms always-in outer region, acanthopores vgs abundant.......... 6*;
o*'Mésopores few or wantiingsc. $5602. 2.a.coanc nec ch dee i0nceener~ enon eee ifs

7. Mesopores scattered or absent, acanthopores small and numerous,
cystiphragms throughout, walls granulose.. XX VI. Monticulipora.
7. Mesopores few, in clusters, acanthopores generally developed, cysti-

phragms in outer region only ................0 XXVIII. Homotrypa.

6* ‘Mesopores MUMEKOUS scase'c0.spacnerkaduee depses > beer neues sauehe seen 8.
8. Apertures irregularly petaloid.................... XXVII. Atactoporella.

8. Apertures rounded to polygorial :....220 00602. 5.56. scene ndsey one eueaneenae £:

g. Massive conical or discoidal usually free, with wrinkled epitheca

Om utider Side l 0s STs cn race dose talae en usses Soee pe rn dd.

dd, Zocecia with cystiphragms............... XXIX. Prasopora.

dad. Zocecia with oblique or funnel-shaped diaphragms (modified

CYSUPM TARE ) acces aw die encetn ammo XXXI. Mesotrypa.

g. Zoarium a thin expansion with epitheca...... XXX. Aspidopora.

c. Diaphragms instead of cystiphragms in outer region of zocecial tubes........... z
t Mesopores’ few’ or absent: 5. ..2 ois ee ara) cecenseehovbeens seg een Vip
7* Acanthoperes presetitc.s, <. 550. .ccteks vases scecnenechs sds >ceh eee tga 9.

g.. Acanthopores lari yo5..025. 512) lic ..f dee. ee oaeeee h.

h. Diaphragms of zocecia few or wanting................ceeeeeee ee.

ee. Erect, ramose, diaphragms few... XXXVI. Dekayia.
ce. Ramose, slender diaphragms practically absent, acan-
thopores sometimes wanting., XX XVIII. Biss

. Diaphragms often mumrerous .. 0. 0.0.00. Técc.sasos ‘ee
ff. Zocecia with well-marked division line between walls.
XXXII. Amplexopora.

ff. Zocecia with periodically thickened walls in mature

SE NGER I A AAS ae win oda, cna ene aay XL. Stenopora.

g. Acanthopores small, few, or wanting..............s.ssscsesseseesees 4;

2. Zooecia with well-marked division line. XXXII. Amplexopora.

2. Zocecia with thick walls... .........6.0.. XXXIX. Evridotrypa.

2. Bifoliate with flexuous mesotheca..... XXXIV. Petalotrypa.

7* Acanthopores absent. iy... 0.0.00. ccccs see cceseeanscsescesenceses case ennai 10.

io. Zocecia with well-marked division line.. XX XIII. Monotrypella.
10. Zocecia thick-walled, many diaphragms.. XXXIX. Lridotrypa.

fMesopores numerous i.) 020. 6s iscce cass osisea se ctenenesad oel¥ensese st sapeseeae anne or.
8* Zoarium ramose, sometimes with anastomosing branches............ i
11, Diaphragms NUMEPOUS!. ... 20... .565. 2. tees eves one oes ceveh ene ps

7. Acanthopores of two sets, large andsmall. XX XV. Dekayella.

| BRYOZOA. 113

ye j- Acanthopores small, few or wanting... XXXIX. Lridotrypa.

a _ g. Acanthopores large, abundant............ XLIII. Batostoma.
je Meamtizopores absent 5 020s aivscceavcs tess XLVII. Callopora.
Fi: Diaphiag meter iis ek eas Se iaeenandaes peace eaters R,

k. Mesopores small with subcircular openings.
XXXVII. Batostomella.
k. Mesopores irregularly angular, often obscurely moniliform.
XLVI. Zrematopora.
8* Zoarium erect, flattened fronds or laminar expansions............... rz.
12. Mesopores gathered into maculz, apertures on elevated stellate
36 ib Oe eR Eerie era, Up eee re | XLI. Constellaria.
12. Mesopores numerous, in interzocecial space, filled and obscured
by calcareous tissue in older individuals.. XLII. Micholsonella.
8* Zoarium encrusting foreign bodies, apertures oval, mesopores abun-
RE Ira tS ec ph ea ean hw ony Sandhwannsveneel XLIV. Stromatotrypa.
8* Zoarium massive, hemispheric, subglobose or discoidal; neither
a mesopores nor acanthopores : zocecial walls often crinkled.
3 XLV. Monotrypa.
“Iv. CRYPTOSTOMATA. Zoaria compound often highly ee ; zocecia with a
short tubular primitive portion, above which, in the ‘‘mature’’ part, is a tubular
shaft or vestibule, often with hemisepta, and surrounded by vesicular or solid
meen cous Licsue ; extettial Orifice FOUME Lo... 62... oe. cs eetedaneans cn socceavwenve’ D.
D. Zoarium a reticulated network or expansion pierced by holes or fenestrules and

celluliferous on one side DAE phe sth vata pee ny vata soa pte de skp caraaiiaehe owas sit 9

tt Branches and connecting bars or dissepiments distinct, the latter non-
PRATER GNIS ACGs hs fpr teddy Mn are LL On ortban d sabe bab eace wate belens 9*.

9* Apertures on branches in two rows separated by a median keel... 13.

13: Keel moderate, plain, or tuberculated................06.c.cc00sene. Z.

7. Funnel-shaped structure (fragments flat)...... L. Fenestella.

c Sowtally wound ais. <i) 3260.5) 600 eia set wes LVII. Archimewes.

13. Keel -high,expanded at the summit’. ..... 65 02..0..0c0iseecis enews mM.

m. Expanded portion of keel with large or scattered pores or

ag ea AMEDD SNS PPT ete 0) Sere Aer LII. Fenestrapora.

m. Expanded portion of keel without pores or pits.
LI. Semicoscinium.
Ey, Keel) supporting a superstructure, iio. k esse dae ccs ecs eats e..
2. Superstructure of thin oblique subimbricating plates (scale).
LIII. Unitrypa.

wm. Superstructure a reticulated network ...... LV. Hemitrypa.
g* Apertures in more than two rows (rarely twoO).............seeeeeeeees 14.
14 No. median: keel -(or Tow-of tubercles} csi. decese ccd ees ieteares 0.

o. Apertures in 2 to 8 rows in a branch, frond as in Fenestella.

LVIIL. Polypora.

o. Apertures in 2 to 5 ranges; frond supported by non-poriferous

U- or, V-shaped Base 2520100. 6 6c eee scaees -LX. Lyropora.

14. A prominent median keel present, with two rows of apertures

GORE GIN iach abtitoncteantat Seed arte LXI. Fenestralia.

tt Connecting bars absent or indistinguishable, branches anastomosing. I0*.
Eo” ‘Branehes irrépularly anastomosing 022.0202. .) cc. esacevedeseseenseecs 15.

15. Two to eight rows of apertures ; reverse side longitudinally stri-

CT Pe hed Ep ORE MAE GIP ae AE XLVIII. Phylloporina.

114 NORTH AMERICAN INDEX FOSSILS.

15. Apertures in 3 to 7 rows; reverse side not striated.

LVI. Reteporidra.
10* Regularly anastomosing, or connected by scarcely recognizable dis-

SUMAN eas itt hen ee casen Sct aane tude det ae Cee 16,
16. Apertures in two rows, carinze expanded sometimes to width of
Rap A ee ee ens Wate kcal LIV. Loculipora.

16. Apertures in 3 to 7 rows, no median carina. LVI. Reteporidra.
D. Zoarium a repeatedly branching frond, the branches rarely united by dissep-

iments (sometimes wanting)....... Jousges yasatd nev aediweseisine stapes ttt.
itt Branches flexuons, ard irr eater. 5935-5 x¢esionnasi n> see onan daese eae LIF;
11* Apertures angular........ See Rie eee mee XLIX. Drymotrypa.

EU WA er inmes aren ed ere. oop th ee aie nabas eas uy LIX. Thamniscus.

ttt Branches rigid, parallel and regular, sometimes absent................. 12.

12* Branches short, free, apertures in two rows with median keel.
LXII. Pinnatopora.
12* Branches long, oblique, smaller than stipe, occasionally united by

thin diesepiments 23) finn icse Se dacs gs annie aoe neonate LXIII. Ptlopora.

P2r AD raMcles: WARE): «ic su tient «2 se cae emake cries LXIV. Diploporaria.

D. Zoarium of more or less cylindrical branches, preserved generally as fragments.
ttt.

ttt{ Branches in articulating segments or articulated basally.............. 13%.

13* Segments with one of several faces longitudinally striated and with-

ONL APOSTLES, 01 vais desennapendeynarnansene ns aeen cies LXV. Arthrostylus.

13* Segments celluliferous on all. sidés......s...:el.ssshedelst eee i

17. Segments uniting by terminal articulation, ends often swollen.
LXVI. Helopora.
. 17. Segments with terminal and lateral (pinnate) articulation, the
segments commonly showing the articulating facet on the side.
LXVII. Arthroclema.
17. Slender, articulating only at the pointed base, branching above.
LXVIII. Mematopora.

iit Branches not articulating si. ccesssissinkevaents <ndeensedgumegy heen 14%,
14* Branch with one side striated and non-celluliferous, the other with

ENO FOWS OL POLES 1 susepewsaswsaneckacueipa+ses LXIV. Diploporaria.

14* Branches celluliferous on all. sideS.....:......:sieessd+5. 0ueseeseeeee 18.

18.- Branches Sou acs. uixeve . binwp vdiaos wloirpie:n view a:dla bin 0'5/a et p-

p. Apertures in diagonally intersecting series.............++00 &e:

ge Without peristomes: .........050000i00seenssee pee 33.

33. Frequently branching ...... LXIX. Khombopora.

33. Simple or rarely branching, pointed at base. —
LXXI. Bactropora.
pee With perigtomess ix sccciccws bh es 44.
44. Compressed, dichotomously dividing.
XCVI. Stictotrypa
é. Apertures in longitudinal series ............... ove <haehmeeeeee hh
hh. Cylindrical with pits between apertures.
LXXII. Streblotrypa.
Ahh. Cylindrical without /pits.<):...:.s..00e«oseueen Orthopora.
15, -Bimeaches hollow. oss 20 ccless edees PPT q-
g. Apertures with depressed vestibules, interspace narrow.

LXX. Coeloconus.,
-

BRYOZOA. 115

a g. Apertures small, with elevated generally oblique peristomes.
a XCV. Diamesopora.
meawonrium bifohate, an. explanate frond...) 2:5. ; 2. sssjesims cecnt-scebwleabwceyseeie pies i

5... Mesopores: present,. frond not.artioglated.. i i.i.0cae<ep splasetaw es weees ese £5".

ESM Mésopords ta bulgtedy 3... janice sn saa de ocean a LXXIX. Coscinella.

15* Mesopores not tabulated... ................006. LXXVII. Stictoporella.

PE LESOMOTED DRONE: Muu dis forcnatas ga aeldne> «ka sod paateby «ab. Vy tibe ane ments th sei es 16*:

16* Articulated basally, vestibules separated by thick walls.
a LXXV. Clathropora.
16* Not articulated, interzocecial spaces with vesicular tissue.
UXXXVI. Coscinium.

Pema bifolate,s not explamates Fs ii as odes scan cvnsp oie yeh bu~ vadaeseseiatniens>se OF.
6 Zoarium jointed or articulated at least at the base ...................e000 1 hl
17* Apertures arranged in longitudinal series,................ssesecseeeeee 19.

19. Simple unbranched, lanceolate or falciform frond with basal

eT altel tS 9k Sea ee ete Pot an LXXIII. Ptilodictya.

Ig. Bushy, of numerous articulating equal segments spread in a

RRL aeeE eee Shc cabs cokes oyna eeeacbee nee LXXVI. Arthropora.

Ig. Segments from cylindrical root, two buds from truncated end

OF PISCEGING,. Biv, cow aatienis sheer meeting LXXXVII. Acrogenia.

17* Apertures in decussating series surrounded by sloping hexagona.
BRC SS ces wide nilee Herons Ri gedek eoeseinys sea as ee LXXIV. L£scharopora.

epee em ATER, PUNE, GELTO DALE. 57 stow digs datviincad vals actus wineries edt ehapecioed at -e 13*.
SR RBCAO MIE ES ECSU ros. far. n ocncinewtengacucd novcesmobyitebap nwa tes'ewveeadae 20.
ac. Miesopotes: tabulated i556 dia dedeneteeeaenes Eo: cativcaeoaaen Fi

vy. Zoarium ramose, compressed, divided dichotomously.
LXXVIII. Lnutrapora.

20. Mesopores untabulated ................006. LXXVII. Stictoporella.
Wee MECUAD INOS: WOSEIIE, o05.0%.y 3.50 acc ucn ceeds ss4cbapehs aeaen do vane ge eons 2a,
21. Branches bifurcating, straight edged with parallel or sub-
parallel margins....... hada ogee bth aid rade Sabet routes «nae seen os S.

s. With well marked lunarium, nearest to the margin.
LXXXIII. Cystodictya.
NA LEMOUT TER OFIUTI; oh: avacceevened< coaccea's’ LXXX. Rhinidictya.
s. Without lunarium, with macule.... LXXXII. Pachydictya.
s. With strong central ridge making section somewhat rhombic.
| LXXXV. Taeniopora.
2a, Branches an.irtegular explanate frond; 0.0. )...:.2...2. 0. ee Saeien he
¢. Apertures subelliptical; thin bifoliate expansions, surface
. with solid. macula nf oc.c ec ecck es LXXXIV. Dichotrypa.
a z. Apertures semi-elliptical, with broad triangular space be-
neath each-aperture. ie... dsewnl. XCILI. Worthenopora.
z. Apertures with eight to ten vertical septa-like ridges.
XCII. Actinotrypa.
z. Apertures oblique, with posterior edge lip-like.

. LXXXI. Phyllodictya.
». Zoarium of prismatic branches triangular in cross-section............... pasittote yee
7{ Branches triangular, with faces crossed by transverse ridges.

LXXXIX. Scalaripora.
7 Faccs of triangular branches without transverse ridges.
LXXXVIII. Prismopora.

116 NORTH AMERICAN INDEX FOSSILS.

D. Zoarium not belonging to the foregoing.................ccccceseeseesees eakaca state St.
8{ Zoarium a thin expansion, traversed on both sides by salient ridges or crests
AAU CML PRM EMI Isl, nartdnis pis aa ceuaigs y bs cuca daa dewmedia se keeied XC, Glyplopora.

8{ Zoarium free, of four or more vertical leaves radially arranged.
XCI. LEvactinopora.
8{ Zoarium a subcircular unilaminar expansion with basal epitheca.
XCIV. Lichenaha.
8{ Zoarium a thin incrustation, with hexagonal or polygonal apertures. .
XCVII. Paleschara.
V. CHILOSTOMATA. Zocecia of various forms arranged side by side with more or less
anterior orifice of smaller diameter than zocecium and closed by a movable cover,
appearing often to occupy the whole surface of zoarium owing to non-calcifica-

tion of the front wall and its removal in fossilization............cccceccceeceeceeeees E.

gE. sBifeliate, mestly frees ir iicehs Nie on ic Ged cudeoee i Soebes dela des od bie of.
ot Apertures in longitudinal series, oval, and occupying most of the cell sur-
BRON Te rigs dp anlveudads Sabie vecilen athe Me Aey en tte eeane tote seas CIII. Aiflustra.

ot Apertures semilunar or crescentic in a large hexagonal area. ©
CIV. Onychocella.

BE, ‘Cellson ote side onbyei 3. Beh, AE 1of.
1oft Cells with openings occupying the whole or nearly the whole of the ex-
posed surlace + eneristing: sts ee oes vd eee CV. Membranipora.

tot Cells with opening only in anterior part; form bulbous or urn-shaped. 19%,
I9* Aperture entire, with one or more supplementary pores.
CVI. Adeonellopsis.
19* Apertures notched below, supplemental pores not present.
CVII. Schizoporella.

PALAZOZOIC SPECIES.
OrpdEk CTENOSTOMATA Busk.

I. RHOPALONARIA Ulrich.

Zoarium sunken for about half its mass into the object on which
it grows (generally a coral, crinoid stem, or shell) and usually pre-
served only as threadlike excavations in the surface of this object,
often filled with clay. Zocecia unknown. Ordovicic—Missis-
sippian.

1. R. venosa Ulrich. (Fig. 177, a!) Ordovicic.

Consists of delicate fusiform cells connected by slender stolons
of the average length of the cells; branching irregular, pinnate or
sometimes netlike. Fusiform cells average 0.3 mm. in length by:
0.1 mm. or less in diameter. Excavated in corals, shells, etc.

Richmond beds of Ohio and Indiana.

2. R. attenuata U. and B. Siluric.
Fusiform cells shorter and farther apart than in preceding.
Niagaran beds of New York and Pennsylvania.

BRYOZOA—CTENOSTOMATA, 117

Pie. 177. a, Rhopalonaria venosa X 9; 6, Ascodictyon florealeX 9; c, Vinella
_ repens X 1; a, Allonema fusiforme X9; ¢, Vinella repens X18. (After Ulrich,
and Ulrich and Bassler. )

_ 3. R. tenuis U. and B. : _ Devonic.
4 Like R. venosus, but fusiform cells narrower and longer, and
connecting stolons shorter.

Hamilton beds of Western New York, Canada and Michigan.

II. Ascopictyon Nicholson and Etheridge.

q Attached to shells, etc., and consisting of ovate or pear-shaped
__ vesicles in clusters or single, arranged along delicate hollow threads
-orstolons. Zocecia unknown. Sil.—Miss.

4. A. stellatum N. and E. Mid-Devonic.
_ Ovoid or pear-shaped calcareous vesicles, generally in clusters
of six or more (sometimes fewer) cells, averaging nearly I mm. in
_ diameter, and connected by filamentous tubes.

Hamilton beds of Western New York and Ontario.

_ 5. A. floreale U. and B. (Fig. 177, 4.) Mid-Devonic.
___ About half the size. of the preceding.

Hamilton of Michigan.

118 NORTH AMERICAN INDEX FOSSILS.

®

Ill. Vinevtxa Ulrich.

Attached to shells, crinoid stems, etc., and consisting of very
slender tubular stolons arranged in more or less distinct radial
manner,each marked in perfect specimens by a single row of pores.
Zocecia unknown.

Arey: repens Ulrich. (Fig. 177, ¢, ¢.) Ordovicic.
Radial arrangement imperfect. Stolons often bifurcating.
' Black River formation of Minnesota.

IV. ALtonema U. and B.

Attached, in form sausage-like strings of vesicles with minute
punctate surfaces and a large pore toward one end. Sil.—Penn. ?

7 A. fusiforme (Nich. and Eth.). (Fig. 177, :d.) Mid-Devonic.
Fusiform, sometimes ovate cells, isolated or joining one another.
Hamilton of Ontario, Michigan and the Falls of the Ohio.

OrpdER CYCLOSTOMATA Busk.

V. STOMATOPORA Brown.
Dichotomously branching colonies of attached subtubular or
subpyriform zocecia, arranged typically in a linear series; aper-
tures subterminal. Ord.—Dev.; Jur.—Recent.

8. S. inflata, Hall. (Fig. 178, a.) Ordovicic.
Pear-shaped cells often forming crowded clusters.
Trenton and Cincinnati beds of New York, Canada, Minnesota,
etc., and in the Cincinnati dome region.

9. S. delicatula (James). (Fig. 178, 2.) Ordovicic.
Cells longer and more slender than preceding.
Stones River to Richmond beds of Ohio, Indiana, Kentucky,
Tennessee, Illinois, lowa and Minnesota.

VI. Prosposcina Audouin.

Adhering, of several fused rows of cells, sometimes a sheet-like
expansion. Zocecia tubular with subterminal apertures. Ord.—
Dev. ?; Jur.—Recent.

10. P. frondosa Nicholson. (Fig. 178, c.) Ordovicic.

Branches reuniting, with distant zocecial apertures slightly

elevated.
Lorraine and Richmond beds of Ohio, Indiana, Kentucky,
Illinois and Manitoba.

BRYOZOA—CYCLOSTOMATA. 119

11. P. tumulosa Ulrich. (Fig. 178, @.) Ordovicic.
Narrow bifurcating branches, with a double (rarely triple) row
of bulbous zocecial swellings with apertures.
. Black River of Minnesota.

Fic, 178. a, Stomatopora inflata <9; 6, S, delicatulaX 12%; c, Proboscina
| frondosa <9; d, P. tumulosa X %, and X 4%; e, Berenicea minnesotensis %
and & 9; f, Diastoporina flabellata K % and * 3%, with annelid tube attached ; g,
_ 4, Mitoclema mundulum XK % and K 4%; 1, Phacelopora pertenuis, X 12% 3 7,
Ceramoporella inclusa X 9, and X 20; , Crepipora simulans, tangential section show-
_ ing a macula and lunaria < 9; /, Coeloclema trentonense X ¥% and K 4%. (All after
_ Ulrich.)

VII. BerenicEA Lamouroux.

Thin, discoid, flabellate or irregular incrustations with tubular
zocecia arranged in irregular, attenuating lines. Ord.—Silur.; Jur.—
Recent.

12. B. minnesotensis Ulrich. (Fig. 178, ¢.) Ordovicic.
_ Zocecia similar to P. tumulosa, arranged in irregular rows ona
_ flabellate surface. .

__ Stones River and Black River of Minnesota.

VIII. Drastoporina Ulrich.

Bifoliate zoaria with tubular zocecia prostrate and partly sunken
into the connecting mass. Ordovicic.

a

120 NORTH AMERICAN INDEX FOSSILS.

13. D. flabellata Ulrich. (Fig. 178, /) Ordovicic.
Flabellate or fan-shaped expansion, minute with distant, tubular
cells projecting obliquely. :
Trenton of Minnesota.

[X. HEDERELLA Hall.

Adhering zoaria with the tubular cells given off on alternate
sides from central tubular axis. Devonic.

14. H. canadensis (Nicholson). (Fig. 179, a, 0.) Devonic.
Profusely branching, with
long, slender zocecial tubes with
oval apertures.
Hamilton group of New York,
Ontario, Falls of the Ohio and
Upper Canada; Onondaga of

®
vat

ZE
° 443
Ontario. Eve
aa
=ErS
X. HeErnopiA Hall. Oess
dy 3 EARS
Similar to preceding, but later [Fy

zocecia budding from preceding
ones. Devonic.

15. H. humifusa Hall.
| Devonic.
Cells 5 mm. long, gradually
enlarging to aperture, which is
about I mm. in diameter, bud-
ding about one third the distance below the aperture.
Hamilton of New York and Falls of the Ohio.

7

K(
m1 Oh
y

pla
4 "yp,

Fic. 179. Hederella canadense, aX
1,412. (After Hall and Simpson. )

XI. Repraria Rolle. |
Like Hederella, but zocecial tubes parallel and closely placed.
Devonic.
16. R. stolonifera Rolle. (Fig. 180, a, 0.) Devonic.

Tubes of equal length, slightly annulated, with the last cell
terminal. 3

Hamilton of Western New York.
XII. Mrrocrema Ulrich.

Minute, cylindrical, branching stems with zocecia bending
abruptly outwards and often projecting free. Ordovicic.

BRYOZOA—CYCLOSTOMATA. 121

17. M. mundulum Ulrich. (Fig. 178, g, %.) Ordovicic.
Branches about half a millimeter in diameter, faintly striated trans-
versely, and with the tube-like zocecia projecting upward and out-
ward in a spiral series.
Trenton of Minnesota.

XIII. PHAcELoPoRA Ulrich.

Zoarium articulated; two or more
conical zocecia form cone-shaped
bundles, with circular slightly con-
tracted subterminal aperture. Ord—
Sil.

18. P. pertenuis Ulrich. (Fig.
178, 2.) Ordovicic.
Minute, thread-like, the segments

in linear series, frequently double,

producing a dichotomous branching,
and each comprising a pair of zoce-
cia, 0.6 to 0.8 mm. in length.

Richmond of Illinois.

XIV. CERAMOPORA Hall.
Fic. 180. Reptaria stolonifera :

} Discoidal zoaria free or attached
_ @, frond on Orthoceras <1; 4,
Mporion enlarged 6. (After Hall by center of base; under surface
and Simpson. ) with one or more layers of small ir-
. - regular cells; zocecia radiating from
_ depressed center on upper surface, with oblique apertures imbri-
_ cating, and short, irregular mesopores decreasing in number out-
a ward. Siluric. |
1g. C. imbricata Hall. (Fig. 181.) Siluric.
_ Depressed hemispheric, flattened or convex on lower side ; aper-
F tures arched or triangular, opening on all sides toward outer mar-
- gin, in alternate imbricating series.

Niagara of New York, Indiana, etc.

XV. Crarmoroeer.s Ulrich.

Zoarium of incrusting layers, often on other Bryozova, with short,
_ tubular, thin-walled zocecia with oval oblique apertures, the lu-
- narium forming a hood ; abundant mesopores. Ordovicic.

<a
a

122 NORTH AMERICAN INDEX FOSSILS.

20. C. inclusa Ulrich. (Fig. 178, 7.) Ordovicic.
Thin incrustations with the oval zocecial apertures occupying,
each with three mesopores, the bottoms of subtriangular or rhom-
boidal obliquely depressed spaces ; lunarium strongly elevated.
Stones River, Black River, and Tren-
ton, of Minnesota.

21. C. distincta Ulrich. Ordovicic.
Apertures oblique, with overhanging
hood, radially arranged about small
macule and separated by a linear series
of mesopores. Fic. 181. Ceramopora imbri-
Utica and Lorraine of Cincinnati ca¢a with enlargement of surface.
region.

22. C. ohioensis (Nicholson). Ordovicic.
Cells in intersecting diagonal lines disposed around elevated
clusters of larger zocecia; few mesopores.
Common in the Utica, Lorraine, and Richmond groups of Ohio,
Indiana, Kentucky, Tennessee, Illinois and Wisconsin.

XVI. Crepreora Ulrich.

Incrusting, lamellate massive, or hollow branches with long,
tubular, thin-walled zocecia, bearing diaphragms, and -having an-
gular or subpyriform apertures, the lunarium not overarching, its
ends usually projecting ; mesopores on elevated or depressed macu-
le. Ordovicic.

23. C. simulans Ulrich. (Fig. 178, £.) Ordovicic.
Clusters of mesopores at intervals of three or four millimeters,
with the zocecial apertures surrounding concentrically and larger
near the clusters; ]unarium not prominent.
Trenton of Kentucky and Tennessee; Lorraine of Ohio, In-
diana, Kentucky and Tennessee; Richmond, of Ohio, Indiana,
Illinois, Wisconsin and Kentucky.

XVII. CoEtocitema Ulrich.

Hollow branches lined internally with striated epithece ; zocecia
as in Ceramoporella, but with thicker walls. Ordovicic.
24. C. trentonense (Ulrich). (Fig. 178, 2.) Ordovicic.

Small apertures in depressed areas, with lunarium not promi-
nent, and two or three mesopores to each zocecium, regularly or
irregularly arranged.

Trenton of New York, Canada and Minnesota.

‘
j

4
i.

BRYOZOA—CYCLOSTOMATA,. £23

XVIII. Anototicuia Ulrich.

Ramose or digitate zoaria of subpolygonal tubes with remote
diaphragms, lunarium elevated at surface, traversed by fine vertical
tabulated tubes. Mesopores few. Ordovicic.

25. A. impolita (Ulrich). (Fig. 182, a:) Ordovicic.

Large, bushy, of frequently and irregularly divided solid
branches ; large, moderately thin-walled zocecia, with hexagonal,

-subrhomboidal apertures, practically of uniform size and with

well-developed lunarium. |
Stones River of Minnesota; abundant and characteristic.

Fic. 182. a, Anolotichia impolita, surface and section, K 9; 4, Ceramophylla fron-
dosa,< ¥% and surface, K 4%; ¢, Bythotrypa laxata, surface, «4% and X 9; d, Fastu-
lipora carbonaria, tangential and longitudinal sections, & 9; e, Chilotrypa hispida-
half of a vertical section with axial tube on right, and tangential section showing inter-
stitial vesicles, 9; /, Buskopora dentuta, surface K 4% and X 9; g, Meekopora
clausa and section, X %. (All after Ulrich. )

XIX. CERAMOPHYLLA Ulrich.
Like Ceramoporella, but erect and bifoliate, the two layers grown
back to back. Ordovicic.

26. C. frondosa Ulrich. (Fig. 182, 2.) Ordovicic.
Fronds 0.5 to 2.0mm. in thickness; substellate macule of meso-

pores at intervals of about 3 mm.; oblique apertures with posterior
margin well elevated, and 2 to 3 mesopores to each zocecium.

Black River of Minnesota.

XX. Bytsotrypa Ulrich.

Massy or lamellate, with long zocecial tubes with thin dia-

_ phragms, subovate apertures and large lunaria. Numerous meso-

124 NORTH AMERICAN INDEX FOSSILS.

pores open to the surface and form internally a loose vesicular
tissue. Ordovicic.

a7 iD. lamatasUnich.. (Big, 182); 0.) Ordovicic.
Massy, originally attached, with basal epitheca; subovate aper-
tures with broad, sharply elevated lunarium; numerous meso-
pores which at intervals form clusters (in weathered specimens)
from which zocecia radiate. Interior irregularly and loosely ar-
ranged; walls of granular structure.
Stones River to Trenton of’ Minnesota, Iowa and Jlinois.

XXI. Fistutrpora McCoy.

Form various, the under surface with wrinkled epitheca; cylin-
drical or somewhat compressed zocecial tubes with few diaphragms,

Fic. 183. Fistulipora torta; a, epithecal side, 1; 4, celluliferous side, K 1; ¢,
enlargement of part of 6. (After Hall.)

BRYOZOA—CYCLOSTOMATA. 125

surrounded by vesicles; apertures subradially arranged about the
maculz, with more or less strongly developed lunarium, and sepa-
rated by smooth or granular interspaces. Siluric to Carbonic.

28. F. neglecta Rominger. Siluric.
Irregular expansion; base with concentrically wrinkled epitheca ;
surface with irregularly scattered, smooth maculz, from which the
circular to oval oblique apertures radiate irregularly. Generally
adheres by celluliferous face. (Generally identified as Lichenala
concentrica.) |
Niagara of Indiana, Kentucky, etc.

29. F. torta (Hall). (Lichenaha torta Hall). (Fig. 183, a—c.)
: Lower Devonic.
Lamellate expansions, flat or involved and contorted, epitheca
finely striated radially on under side, and sharply on upper (when
cells are removed), nodose at junction, with concentric striz ; aper-
tures circular or oval to trilobate, posterior margin strongly ele-
vated and separated by interspaces of equal size with the apertures.
Helderbergian (Coeymans) of New York, etc. *

30. F. carbonaria Ulrich. (Fig. 182, d.) | Carbonic.
Irregularly lamellate or submassy, diameter several inches, thick-
ness half an inch or a little more. Apertures oval or circular, with
thin, inconspicuous peristome, with a single row of angular meso-
pores which at intervals form substellate maculz.
Upper Coal Measures of Missouri, Kansas, etc.

XXII. CuHitotrypa Ulrich.
Small, ramose, with narrow, irregularly contracting and expand-

3 4 ing axial tube; oblique elliptical apertures, the lower margin thick

and elevated ; diaphragms few or none. Sil.—Miss.

31. C. hispida Ulrich. (Fig. 182, 2.) Mississippian.
Zocecia in regular obliquely intersecting series, 8 or 9 in the
space of an inch; small maculz, surrounded by somewhat larger
cells; lip decreasing from posterior end forward ; interspaces dense
above, vesicular lower down.
Chester of Illinois and Kentucky.

32. C. ostiolata (Hall). (Fig. 184, a, 184, 2.) Siluric.
Irregularly branching cylindric stems, gradually tapering toward
the extremities, which are obtuse; apertures about their extremity

126 © NORTH AMERICAN INDEX FOSSILS.

apart, arranged in spirally ascending lines or irregularly; strong
peristomes; interapertural spaces smooth ; stems solid or encrust-
ing crinoids,

Rochester shales of New York and Ontario.

Fic. 184, a. Chelotrypa ostiolata, branch Fy, 184, 4. Chilotrypa ostiolata; en-
natural size and enlargement. larged.

XXIII. Busxkopora Ulrich.

Like Fistulipora, but with pronounced lunarium projecting as
bidenticulate process nearly half across aperture. Devonic.

33... B. dentata Ulsich, “(Vig. 182, 7.) Devonic.
Incrusting or free expansions, with concentrically wrinkled

epitheca on lower side; apertures in regular diagonally intersecting

lines; slightly elevated macule with smooth centers, at intervals

of 5 mm. ‘
Hamilton of Falls of the Ohio.

XXIV. MeEEKopora Ulrich.

Bifoliate (two layers growing back to back), zocecial tubes gently
curving outward, opening obliquely, distally pointed, and with
numerous diaphragms. Convex elevations or ovicells with small
apical opening occur at intervals. Silur.—Carb.

34. M. clausa (Ulrich). (Fig. 182, g.) Carbonic.

Compressed branches, surface with substellate macule, between —
which the zocecia are uniformly distributed in very regular oblique
series; interapertural space flat or slightly concave, usually smooth
or minutely pitted or granular, vesiculose in lower part.

Chester of Illinois and Kentucky.

BRY OZOA—CYCLOSTOMATA, TREPOSTOMATA. 127

XXV. BOTRYLLOPORA Nicholson.

Disk-shaped, often coalescing, attached bodies, the apertures in
two rows on elevated radiating ridges, increasing by bifurcation or
implantation towards margin,
No lunaria. Devonic.

35. B. socialis Nicholson. (Fig.
185.) Devonic.
Alternate ridges extend to the

central area, others one-half to

two thirds that distance; aper-
tures minute, often in contact or
= | inosculating.

Fic. 185. Botryllopora socialis, por- Hamilton of Western New

cin. aoe gt et ie York, Ontario, Michigan, and the

Falls of the Ohio.

OrDER TREPOSTOMATA Ulrich.
XXVI. Monticutipora d’Orbigny.

Form various, of prismatic zocecia with cystiphragms and poly-
gonal apertures; monticules and acanthopores occur; mesopores
few or wanting; zocecial apertures polygonal; cystiphragms in
mature region. Ord.—?Dev.

36. M. mammulata d’ Orb. Ordovicic.
Irregularly lobate or palmate, with prominent conical or some-

times elongated monticules; cells of monticules of about same

_ size as others.

Lorraine of the Cincinnati region and Kentucky.

37. M. arborea Ulrich. (Fig. 186, a.) Ordovicic.
Subcylindrical branches, monticules low or absent, apertures
with minutely granular walls bearing acanthopores. No meso-
pores.
Trenton of Minnesota, Iowa, and Kentucky.

XXVII. ATACTOPORELLA Ulrich.
Generally encrusting ; apertures petaloid, mesopores numerous,
frequently isolating the zocecia; acanthopores very numerous.
Ordovicic. .

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an

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a SP
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Fic. 186. a, Monticulipora arborea, peripheral part of vertical sect.*and tangential
sect. x 9; 4, Atactoporella typicalis var. praecipta, surface X 9; c, Homotrypa subra-
mosa, surface X 4%, ¢’’ & g and ¢’ half of vertical sect. & 9; d, Prasopora simulatrix,
tangential and vertical sections & 9; e, Aspidopora elegantula, entire head & %; e!,
part of surface 4% ; f, Mesotrypa quebecensis, vertical and tangential sections < 9,
&, Amplexopora cingulata, tangential sections & 9 and & 20, (All after Ulrich.)

38. A. typicalis Ulrich. (Fig. 186, 0.) Ordovicic.
Thin crusts on other bryozoans, groups of larger cells at un-

equal intervals, sometimes on monticules ; cells very regular.
Utica of Kentucky and Ohio. A closely related variety (var.

precipta Ulrich) occurs in the Black River of Minnesota.

XXVIII. Homorrypa Ulrich.

Frondescent or ramose, the surface showing monticules or
maculze of larger cells; zocecia with very thin or finely crenulated
walls, remote diaphragms in immature and cystiphragms in mature
region, and apertures often oblique. Mesopores and acantho-
pores present, the former few and in clusters. Ord.—Sil.

39. H. subramosa Ulrich. (Fig. 186, c.) Ordovicic.
Irregularly branching; monticules low and ill-defined; axial
region tabulated.
Black River of Minnesota.

BRYOZOA—TREPOSTOMATA. 129

40. H. obliqua Ulrich. Ordovicic.

Flattened branches with well-developed monticules as in Mont-
culipora, from which it is readily distinguished by the larger cells
of the monticules.

Lorraine of Cincinnati region.

41. H. curvata Ulrich. | Ordovicic.
Differs from preceding in absence of monticules, and occurrence

_ of stellar maculz of minute cells, but appearing smooth, and sur-

rounded by larger cells than average.

Lorraine of the Cincinnati region.

42. H. flabellaris Ulrich. Ordovicic.
Growth fan-shaped, surface with obscure maculz with centers
_ about 4 mm. apart; walls of tubes very thin, appearing flexuous
_ or crenulated in section, with few remote diaphragms in zocecia,
_ but many in mesopores.
Lorraine and Richmond of Illinois, Ohio, Indiana, Kentucky
and Tennessee. Common.

_ 43. H. minnesotensis Ulrich. Ordovicic.
Subcylindrical branches from 5 to 15 mm. in.diameter, gener-
ally dividing dichotomously ; clusters of larger cells conspicuous
in one variety, raised on monticules, about 25 mm. between cen-
ters; true mesopores wanting, acanthopores exceedingly small
and few; apertures oblique.

Stones River and Black River of Minnesota, Iowa, Kentucky.
and Tennessee.

XXIX. Prasopora Nicholson and Etheridge.

Massy, usually free, with wrinkled |epitheca on under side;
_ zocecia prismatic or cylindrical, thin-walled, with cystiphragms,
and generally surrounded by angular mesopores with crowded
_ diaphragms; acanthopores rarely numerous or strong. Ordovicic.

44. P. simulatrix Ulrich. (Fig. 186, d.) Ordovicic.
_ Discoidal to hemispheric or subconic, base concave; clusters of
_ larger cells with more numerous mesopores at intervals of about

4 mm., sometimes on monticules; an average of I1 cells in
p 3mm.

Black River and Trenton of Kentucky, Tennessee, Wisconsin,
and Minnesota.

°

130 NORTH AMERICAN INDEX FOSSILS.

45. P. lycoperdon (Hall). | Ordovicic.

Differs from preceding in absence of monticules and in large
irregular clusters of closely tabulated mesopores, an average of
9 cells in 3 mm., both cells and mesopores being somewhat larger
than in preceding species. (The original description is applicable
to so many species, which have gone by this name, that many
authors have discarded it altogether.)

Trenton of New York, Canada, etc.

XXX. ASPIDOPORA Ulrich.

Zoarium expanded or of superimposed layers, with a basal epi-
theca; zocecia decreasing in size outward from center, without
diaphragms and few cystiphragms; mesopores numerous, with
close diaphragms; acanthopores small or absent. Differs from
the preceding mainly in small size and thinness of expansion.

46. A. elegantula (Ulrich). (Fig. 186, e.) | Ordovicic.

Surface with large clusters of large cells at intervals of 3 or 4
mm., generally elevated ; mesopores between all zocecia; cysti-
phragms practically or quite wanting.

Trenton of Minnesota.

47. A. newberryi (Nicholson). Ordovicic.
Differs from preceding in absence of elevations and in greater
abundance of cystiphragms, which occur in each zocecium.
Utica beds of the Cincinnati region.

XXXII. Mesotrypa Ulrich.
Like Prasopora, but flatter, and with oblique or funnel-shaped
diaphragms, and zocecia separated by angular: mesopores with
numerous diaphragms; acanthopores sometimes large. Ord.-Sil.

48. M. quebecensis (Ami). (Fig. 186, /) Ordovicic.
Varying in height from 4 to 20 mm., and in diameter from 12
to 45 mm. Normal zocecia II or 12 in 3 mm., those of the
clusters 0.4 to 0.45 mm. in diameter; oblique diaphragms in
zones; acanthopores wanting.
Trenton of Quebec, Vermont, New York, Kentucky and Iowa.

XXXII. AMPLExoPORA Ulrich.

Ramose, discoidal or massy, with prismatic zocecia with dia-
phragms; acanthopores variable. Ordovicic.

BRYOZOA—TREPOSTOMATA. 131

_ 49. A. cingulata Ulrich. (Fig. 186, g.) Ordovicic.
4 Ramose, of cylindrical or subcylindrical branches dividing dicho-
| tomously; no monticules; apertures subpolygonal, a moderately
thin wall studded with granules between them; groups of cells of
larger size; no mesopores.

Lorraine of Kentucky and the Cincinnati, O., region.

XXXIII. MonorrypPetta Ulrich.

Like Amplexopora, but distinguished by the absence of acantho-
pores. Ord.—Dev. |

50. M. (Rhombotrypa) quadrata (Rominger). Ordovicic.
Irregularly cylindrical branches, from 4.5 to 10.5 mm. thick, the
tubes rhombic in section, arranged in curved diagonal lines. No
mesopores or monticules.
‘Richmond beds of Ohio, Indiana, Illinois, Wisconsin and Mani-
toba. Common and characteristic.

51. M.? arbuscula (Hall). (Fig. 187.) Siluric.
Fruticose, several slender (2-3 mm.) stems from a single base ;

bifurcation frequent; cell tubes very gradually diverging to surface.
A characteristic fossil of the Manlius limestone of New York.

Fic. 187. Monotrypella ? arbuscula.

XXXIV. PETALOTRYPA Ulirich.

Irregular, compressed, bifoliate branches or fronds, with pris-
matic zocecia arising from strongly flexuous mesotheca, with poly-
_gonal apertures. Devonic.

52. P. compressa Ulrich. (Fig. 190, a.) Devonic.
Smooth, with scarcely appreciable clusters of slightly larger and
_ somewhat more separated cells; zocecia subpolygonal to hexa-

132 NORTH AMERICAN INDEX FOSSILS.

gonal; mesopores irregular, scattered, sometimes in clusters;
height 2 mm. or more; width I cm. or less; thickness I to 4 mm.
Hamilton of Iowa and Illinois.
XXXV. DeKkavecra Ulrich.
Ramose, zocecia with numerous diaphragms, large and small
acanthopores, and a variable number of mesopores. Ordovicic.

53. D. praenuntia Ulrich. (Figs. 188, 4, 1go, 4.) Ordovicic.

YT

Fic. 188. 6, Dekayella prenuntia var, echinata,; e, Bythopora herricki; f, Erido-
trypa mutabilis,; 7, Constellaria floridi,; 7, Batostoma winchelli; k, B. fertile; m,
Stromatotrypa ovata; n, Callopora multitabulata,; 0, Nichoisonella pulchra, broad
form. All natural size. For further illustrations see Fig. 190, corresponding letters.
(All after Ulrich. )

Compressed cylindrical, from 4 to 12 mm. in diameter; no
monticules, but inconspicuous clusters of large cells; few, irregu-—
larly disposed mesopores and acanthopores.

Black River of Minnesota.

54. D. obscura Ulrich. | Ordovicic.
Small, slender stems, variously branching; monticules obscure.
Utica of the Cincinnati region.

55. D. ulrichi (Nicholson). Ordovicic.
Coarse, subcylindrical’ branching stems, three or more times the

diameter of preceding; low monticules of smaller cells (meso-

=

BRYOZOA—TREPOSTOMATA. 133

pores) regularly disposed, and surrounded by cells somewhat
above the average in size.
Utica beds of the Cincinnati region. A common fossil.

XXXVI. Dexayia E. and H.
_ Subcylindrical or flattened stems growing from large base; one
set of acanthopores and few or no mesopores and diaphragms.
Otherwise like preceding. Ord.—?Dev.
56. D. aspera E. and H. (Fig. 190, ¢.) Ordovicic.
General form and aspect like Dekayella ulnchi, from which it

_ differs in generic characters.

'
-

Lorraine of the Cincinnati region.

XXXVIJ. Batostometta Ulrich.
Slender branches, with thick-walled zcecia, few diaphragms, and

~ small circular or oval apertures with rounded or canaliculate inter-
_ spaces; numerous small acanthopores, and mesopores, the latter
_ with subcircular openings. Sil._Perm.

57. B. granulifera (Hall). ot eer
Oval to elongate apertures margined by wavy, raised, granu-

. lose lines, double between cells.

Rochester shale of New York, etc.; common. Waldron, Ind.

_ 58. B. spinulosa (Ulrich). (Fig. 190, @.) Mississippian.

Subcircular or oval apertures, surface hirsute in well preserved

_ specimens, from abundance of acanthopores.

Chester of Kentucky and Illinois.

XXXVIII. ByrHopora Miller and Dyer.
Usually slender branches, zocecia practically without diaphragms,

and with oblique apertures, canaliculate interspaces, few meso-
_ pores and comparatively strong acanthopores, rarely more than
_ one to each zocecium. Ord.—Dev.

59. B. delicatula (Nicholson). Ordovicic.
Like Bythopora spinulosa, but without the spines.
Richmond beds of Ohio, Indiana, Ontario and Manitoba.

60. B. herricki Ulrich. (Figs. 188, ¢, 190, ¢.) Ordovicic.

Similar to preceding, but with apertures long drawn out anter-

_ iorly and narrower.

Black River of Minnesota.

134 NORTH AMERICAN INDEX FOSSILS.

61. B. spinulosa (Hall). (Fig. 189.) Siluric.
Oval apertures on cylindrical branches with strong spines at
regular intervals.
Rochester shales of New York, etc.

XXXIX. Eripotrypa Ulrich.

Of slender branches with more or less oblique thick-walled
zocecia with diaphragms which may be absent in the axial and
apertural regions. Mesopores with close-
set diaphragms, acanthopores small and
scarce, or wanting. Ord.—Dev.

62. E. mutabilis Ulrich. (Fig. 188, f
190, 7.) Ordovicic.
Slender, branching, cylindrical stems av-

eraging 3.5 to 4.5 mm. in diameter. Aper-

tures very oblique, especialiy in young speci-
mens. Small macule commonly present
in older stems. Axial portion of tubes with
diaphragms distant about twice their diam-
eter:

Trenton of Minnesota, Iowa, Wisconsin,

Kentucky, Tennessee, Ohio and Canada.

Fic. 189. LBythopora spin-
wlosa, enlarged.

63. E. similis Bassler. Siluric.
Zoarium apparently free, consisting of a pointed basal portion
growing upward into branching stems.
Niagara (Rochester) of Western New York and Ontario. —

XL. STENOPORA Lonsdale.

Form varying from ramose to laminar or encrusting, with or
without monticules, and with wall of the zocecia periodically thick- —
ened in the mature region; diaphragms perforated centrally ; few,
irregularly distributed mesopores and large acanthopores. Miss.—
Mid-Carb.

64. S. carbonaria (Worthen). (Fig. 190, g.) Carbonic.
Subcylindrical branches 10 to 15 mm. in diameter ; surface
smooth, no cell clusters; apertures angular to subcircular, fre-
quently thick-walled, with numerous acanthopores and few meso-
pores.
Coal measures of Illinois, Kansas and Ohio.

BRYOZOA—TREPOSTOMATA. 135

XLI. CoNSTELLARIA Dana.

Erect, flattened branches or fronds from an attached basal ex-
pansion ; surface with depressed stellate macule, the spaces be-
_tween rays elevated and bearing two or three short rows of closely

“f

fees:

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NUNS

Fic.190. a, Petalotrypa compressa, tangential sections with few, and with many meso-
pores, @’’, vertical section, « 9; 6, Dekayella praenuntia, b’, var. echinata, surface
bs 4%; 6/’, var. multipora, thin-walled, small acanthopores, 9; 6//’, same, thick-
walled, large acanthopores, 9; d'”, same, & 25; 4’, same, vertical section, x 9;
¢, Dekayia aspera, tangential section, & 9; d, Batostomella spinulosa, %, and ver-
tical section, tangential section and surface, * 9; ¢, Bythopora herrickit, KX 4%; S;
Lridotrypa mutabilis, surface, * 4% ; g, Stenopora carbonaria, vertical section, X 9,
_ A, Constellaria varia, surface, X 4% ; 7, Batostoma winchellt, surface, K 4% and X 9
| &, B. fertile, var. circulare, surface, X 9; 1, Hemiphragma tenuimurale, surface with
4 incomplete diaphragms, « 41%; /, part of vertical section, & 9; m, Stromatotrypa
ovata, surfaces of two different layers (’ and m/’), «9; 2, Callopora multitabulata;
n’, surface, K 4% ; 2’’, surface showing zocecial covers, & 9; //’, vertical section,
<9; 0, Nicholsonella pulchra, surface K 4%. (All after Ulrich.)

approximated apertures; mesopores aggregated into macule with
crowded diaphragms. Ordovicic.

136 NORTH AMERICAN INDEX FOSSILS.

65. C. varia Ulrich. (Fig. 190, 2.) Ordovicic.
Flattened branches with large, irregularly stellate maculze very

slightly depressed ; zocecial apertures in clusters of from 4 to 10

each, slightly or not at all elevated; apertures subcircular.
Trenton of Minnesota, Canada and Tennessee.

66. C. florida Ulrich. (Fig. 188, 2.) Ordovicic.

Flattened branches covered with crowded “stars,” the rays
sharp, petaloid and strongly elevated.

Lorraine of Cincinnati, Ohio, Indiana, Kentucky and Tennessee.

Common.

XLII. NicHorsonerra Ulrich.

Laminar expansions, sometimes giving off flattened intertwining
branches or fronds ; interzocecial spaces wide, with numerous meso-
pores, having thicker and more numerous diaphragms than zocecial

tubes, but obliterated with age by filling of secondary calcareous
deposit. Ord.—Sil.

67. N. vaupeli Ulrich. Ordovicic.
Flattened, inosculating expansions with evenly distributed, low
monticules of larger pores than ordinary, with center free from
pores.
Lorraine of Cincinnati region.

68. N. pulchra Ulrich. (Fig. 188, 0, 190, o’.) Ordovicic.
Irregular, flattened branches, monticules faint and often indefi-
nite; interzocecial space papillase.
Stones River of Tennessee.

XLUI. Batostoma Ulrich.
Irregular branches from large basal expansion; zocecia thin-
walled in immature and thick in mature region, ring-like in section, —

with diaphragms ; mesopores irregular; acanthopores large. Or-
dovicic.

69. B. winchelli Ulrich. (Fig. 188, 7, 190, 7.) Ordovicic.
Subcylindrical or slightly compressed branches 4 to 10 mm. in
diameter, with rounded or subangular zocecial apertures with ridge-
like walls bearing acanthopores. Mesopores few.
Black River of Minnesota.

70. B. fertile Ulrich. (188, 2, 190, £.) Ordovicic.
Large, of coarse, compressed branches, with round or polygonal

BRYOZOA—TREPOSTOMATA. 137

apertures and often few mesopores. Clusters of larger zocecia en-
close a stellate macula scattered over surface.
Stones River of Minnesota.

Fic. 191. MJonotrypa tabu-
Were, a, fragment, <1; 34,
tangential section, 6, c, en-

_ largement of a group of tubes
showing corrugations. (After

Hall.)
ay

71. B.(Hemiphragma) tenuimurale UI-
fich,: (Fig..190, 2.) Ordovicic.
Cylindrical or compressed stems with

thin-walled polygonal apertures, without

acanthopores and few mesopores; dia-
phragms in peripheral region incomplete.
Galena of Minnesota.

72. B. (Hemiphragma) whitfieldi
(James). Ordovicic.
Like preceding, but more robust, and

with crinkled’ walls, readily seen on

-broken surface

Utica horizon of the region about Cin-
cinnati. ;

XLIV. Srromatotrypa Ulrich.

Encrusting, with short zocecia, oval in
cross section and with few diaphragms,

Walls thin, with periodically con-
stricted tubuli, one or more to each
zocecium. Oval apertures with minutely
papillose peristomes, separated by de-
pressed interspaces. Closely tabulate
mesopores, rarely showing on surface.
Ordovicic.

73. S$. ovata ~Ulrich.«. (Fig. 188,. m,
190, 7’.) “ -. Ordovicic.
Encrusting shells or other Bryozoa,

rarely free; without monticules, but with

smooth areas of more widely separated
apertures.

Stones River and Black River of Min-
nesota and Wisconsin.

MonorrypPa Nicholson.

Massy hemispheric or discoidal, zocecia comparatively large
prismatic, with thin and often crinkled walls throughout; dia-

138 NORTH AMERICAN INDEX FOSSILS.

phragms remote; no mesopores or acanthopores; mature and
immature regions indistinguishable. Ord.—Sil.

74. M. tabulata (Hall). (Fig. 191, a—c.) Lower Devonic.
Spheroidal or hemispheric; tubes polygonal, with thin and
strongly corrugated walls, the corrugations forming nodes at the
angles.
Helderberg (Coeymans and Port Ewen) of New York, etc.

75. M. ? amplectens Grabau. (Fig. 192 a—d.) Devonic.
Encrusting brachiopod shells, generally large Spirifers on which
species of Aulopora have grown. The openings of the Aulopora

oy vs

Ss
=

Os

Fic. 192. Monotrypa amplectens. a, encrusting Spirifer shell to which are attached
tubes of Aulopora, X 1; 4,.surface, X 8; ¢c, vertical section enclosing Au/opora, K 5;
d, surface surrounding mouth of Aulopora, * 8.

tubes are scattered among the apertures of the bryozoan, similar
to the ‘‘Caunopora” type of Stromatoporoids. Sometimes on
other corals.

Surface with monticules of larger apertures at regular intervals;
apertures angular; walls finely striated; diaphragms remote in
older, more closely set in outer part of tube.

Hamilton of Western New York and Michigan.

BRYOZOA—TREPOSTOMATA. 139

XLVI. TrematTopora Hall.

Zoarium ramose; surface smooth or with monticules; zocecia
thin walled, the contact lines of walls of adjoining zocecia distinct ;
diaphragms few, in the proximal end of zocecia ; apertures circular
or oval with a more or less well-marked peristome ; interspaces
solid; mesopores irregularly angular,
often obscurely moniliform, with dia-
phragms at the constricted parts; acan-
thopores of medium or small size usually
present.

76. T. tuberculosa (Hall). (Fig. 193.)
Siluric.
Irregularly ramose and stout branches;
tuberculous monticules; tubular cells
with oval apertures and thin elevated
calicle or margin which is spinulose (bearing acanthopores); in-
terapertural spaces solid, but separate below.
_ Rochester shales of New York.

Fic. 193. Zrematopora tu-
berculosa with enlargement of
surface. ;

Senate Cavvorows Park:

Branching, and frequently anastomosing into bushy clumps,
_ with prismatic zocecia which later become, in most cases, cylindri-
cal, and have their apertures operculated; diaphragms closely set
except in central part of tube, and crowded in the angular meso-
pores. Ord.—Sil.

77. C. multitabulata (Ulrich). (Fic. 188, 2, 190, 2.) Ordovicic.
With strongly elevated monticules, few mesopores and numer-
ous diaphragms.
Black River and Trenton of Kentucky, Tennessee, Minnesota,
Canada, etc.

_ 78. C. ramosa (d’ Orbigny). (Fic. 194, 1.) Ordovicic.
_ Forming large clusters of stout, irregular, cylindrical stems, with
strong, sharp monticules subregularly arranged, rarely uniting into
ridges. |
Common in the Lorraine of the Cincinnati region.
79. C. dalei (E. and H.) (Fic. 194, 3.) ; Ordovicic.
Branches more slender than preceding and with less prominent
monticules, which sometimes unite into ridges, as in the next
_ species.
Lorraine beds of the Cincinnati region.

,

140 NORTH AMERICAN INDEX FOSSILS.

80. C. rugosa (E. and H.) (Fic. 194, 2.) Ordovicic.
Of the type of C. vamosa, but the monticules united into prom-
inent transverse ridges with zocecial apertures. ~
Lorraine beds of the Cincinnati region.

Fic. 194. 1, Callopora ramosa, XI ; Ia, enlargement of surface; 2, C. rugosa,
X13; 3, C. dalet, XK 1; 3a, surface enlarged. (After Nicholson. )

81. C. elegantula Hall. (Fic. 195, a0.) Siluric.
Branches solid, extremities often hollow or cup-like, apertures

circular, the opercula with central perforation and radiating ridges.
Niagara of New York, Ontario, Indiana, Illinois, etc.

Fic. 195, a. Callopora elegantula with ‘FIG. 195, 4. Callopora elegantula, a

enlargements of surface and individual fragment much enlarged.
tubes.

OrDER CRYPTOSTOMATA Vine.

XLVIIL Puytroporina Ulrich.

Irregularly anastomosing branches, with two to eight rows of
apertures on one side, the other longitudinally striated; tabulated
interspaces, closed at the surface, generally present ; acanthopores
often present. Ord.—Sil.

~

BRYOZOA—CRYPTOSTOMATA. 141

® 82. P. reticulata (Hall). (Fic. 201, 2.) Ordovicic.
Generally as fragments of depressed, funnel-shaped zoarium with
rounded branches 0.2 to 0.3 mm. in diameter, frequently and regu-
larly inosculating; fenestrules about as wide as branches; three

‘Fic. 196. Phylloporina asperato-striata with enlargement of celluliferous and non-
celluliferous faces, the latter showing the asperate-striate character.

_ irregular rows of zocecia with subcircular apertures and numerous
- acanthopores ; reverse side finely striated.

Black River and Trenton of New York, Vermont, Minnesota
4 _and Canada.

¥ 83. P. asperato-striata (Hall). (Fic. 196.) Siluric.
_ Oval, somewhat unequal fenestrules; outer face roughly striated,
inner with three, four or more rows of subangular cells in
_ obliquely parallel lines. |
Rochester shale of New York, Canada; etc.

Fic. 197. Drymotrypa diffusa with celluliferous sides enlarged.

XLIX. Drymotrypa Ulrich.

Dichotomously and frequently branching, longitudinally striate .
on one side, and on the other with several ranges of tubular zocecia

t

142 NORTH AMERICAN INDEX FOSSILS.

springing from a thin double plate; vestibules expanding from
orifices to angular apertures. Ord.—Sil.

84. D. diffusa (Hall). (Fic. 197.) Siluric.
Several stems originate from a common base, forming a shrubby
frond ; stems frequently bifurcate and spread laterally ; apertures
quadrangular or subrhomboidal.
Rochester shale of New York.

L. FENresTELLA Lonsdale.
Fan or funnel-shaped reticulated expansion of straight or flexu-
ous rigid branches, apertures united by non-celluliferous cross-bars
or dissepiments at regular intervals; two rows of apertures on the

inside of branches, separated by a plain or tuberculated median
keel. Ord.—Carb.

85. F. elegans Hall. (Fic. 198.) Siluric,
Carina subdued, apertures with longer diameter oblique to direc-
tion of branches, which are slender and frequently bifurcating, and
are united by thin dissepiments; fenestrules on non-celluliferous
side oblong-quadrangular, rarely oval.
Niagara of New York, Canada, etc.

Fic. 198. enestella elegans with enlargements.

86. F. crebripora Hall. . Lower Devonic.
Fenestrules wider than branches which are connected by dis-
sepiments, slightly enlarging at contact; keel faint; non-celluli-
ferous side finely striated.
Helderbergian of Eastern New York, etc.

il

SS eS ss es. ee ae oe: eo er’

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BRYOZOA—CRYPTOSTOMATA. 143

87. F. emaciata Hall. (Fic. 199.) Mid-Devonic.
Large funnel-shaped ; dissepiments thin and oblique ; keel prom-
inent; apertures closely and regularly disposed.
Hamilton of New York.

88. F. cestriensis Ulrich. (Fic. 201, c.) Mississippian.
Branches irregularly dividing, slightly flexuose; carina angu-
lar; apertures circular, with peristomes; reverse side rounded,
smooth exept for scattered nodes.
Chester of Mississippi Valley, Kentucky, etc.

Fic. 199. Fenestella emaciata. a, fragment of frond (reduced) ; 4, non-cellulifer-
ous face showing striated branches and oblique dissepiments, 4; ¢, celluliferous face,
4; d, transverse section of branches, <4; ¢, lateral view of branches, showing
position of apertures, <4. (After Hall.)

89. F. tenax Ulrich. (Fic. 201, 4.) Mississippian.
Fenestrules narrower than branches; dissepiments moderately
thick ; no nodes, but faint striations on reverse side ; apertures cir-
cular, with peristomes.
Chester of Mississippi Valley and Kentucky ; Waverly of Ohio.

LI. Semicoscinium Prout.

Funnel-shaped, all openings on outer side, wide, short dissepi-
ments, the branches appearing to anastomose on non-poriferous
face, whose fenestrules are subrhomboidal or rounded; apertures in
two rows; median keel very high, expanded at the summit.
Sil.—Dev.
go. S. tenuiceps (Hall). (Fic. 200.) Siluric.

Carina sharp and thin; transverse dissepiments do not extend
as high as the branches, sometimes scarcely visible; apertures

144 NORTH AMERICAN INDEX FOSSILS.

large, round, opening laterally; fenestrules oval on non cellulifer-
ous side, which is striated, but appears granular when worn. -
Rochester shale of New York, Canada, etc.

Patt =~ eet:
ANG Stage R4grty
Meenntgrs tat
patios tetog, st cei 7 é

Fic. 200, a. Semicoscinium tenuiceps. Fic. 200, 6. Semztcoscinium tenutceps.
Clinton ; with enlargements. Niagara ; enlargements of celluliferous and
non-¢elluliferous faces.

g1. S. planodorsatum Ulrich. (Fic. 201, d.) Devonic.
Fenestrules. very small; carina prominent, with circular aper-
tures; reverse side flat, with irregularly oval to circular fenestrules,
showing no evidence of branching.
Hamilton of Falls of the Ohio.

Is IG
sped? £
A * taee~

Fic. 201. a, Phylloporina reticulata, X 9; b, Fenestella tenax, obverse and re-
verse faces, & 4% ; c, F. cestriensis, obverse face, K 443 @, Semicoscinium planodor-
satum, obverse side, K %4 and X 4%; ¢, Henestrapora occidentalis obverse, 4% ;
f, Hemitrypa proutana, non celluliferous and celluliferous faces, the latter with part of
superficial network, 414; g, var. nodulosa, X 4%; h, Reteporidra perundata, ob-
verse face, X 4%. (After Ulrich. ) :

SS ee ee er ee

ee

BRYOZOA—CRYPTOSTOMATA.: 145

LII. FENESTRAPORA Hall.

Differs from Seszcoscentum in the reverse of the zoarium and the
expanded summits of the carine being furnished with large scat-
_ tered pores or pits. Devonic.

92. F. occidentalis Ulrich. (Fic. 201, ¢.) Devonic.
Fenestrules oval; carina angular and expanded; the irregu-

larly disposed pits on the side, rather few in number; frond rather

coarse. . |
Hamilton of Iowa.

LIII. Unirrvpa Hall.

_ Differs from Fenestella in having the prominent carinze thick-
ened above and connected by thin, oblique, subimbricating plates

(scalz) varying from two to each fenestrule to the number of zocecia.
Sil.—_Dev.

93. U. scalaris Hall. (Fig. 202,a-¢.) — Devonic.

Fic. 202. Unitrypa scalaris. a, fragment of carinz and scalz ; 4, summits of car-
inz and scale, showing nodes on former, & 4; ¢, fragment showing thin carinz and
scale, X 4; d, fragment showing under side of carinz and scale, 4; e, /, transverse
sections of different fronds, <4; 2, transverse section much enlarged to show rhom-
_ boidal sections of branches, with dissepiment connecting them, the thin expanding car-
_ ine connected by scale. _ (After Hall.)

_ Branches straight, parallel and rigid, the carinz and scale mak-
ing a ladder-like structure, the carine projecting above the very
_ oblique scale. .
= meeemilton of New Mracls and Ontario.

146 NORTH AMERICAN INDEX FOSSILS.

94. U. acaulis Hall. Devonic.
Scalz very slender and closely disposed ; summit of carina very

prominent, sometimes noded. Length and width of fenestrules on

celluliferous face as 3 to 1; on non-celluliferous, as 2 to 1.
Hamilton of Falls of the Ohio.

LIV. Locuuipora Hall.

Funnel-shaped, dissepiments non-poriferous, reduced to a mini-
mum, carinated like the branches; the carine coalesce and expand
at the summits, their width usually equalling that of branches and
dissepiments. Sil.—Dev.

95. L. perforata (Hall). (Fig. 203.) Devonic.
Frond regularly reticulated, the fenestrules oval in a depressed
hexagonal surface, and each surrounded by nine or ten apertures.

|

Fic. 203. Loculipora perforata, a, fragment showing manner of growth; 4, non-
celluliferous face, showing angular slightly carinated branches and dissepiments, XK 4;
¢, celluliferous face, & 4. (After Hall.)

The expansion of the carina may make this face appear like the
non-poriferous face.
Hamilton of New York.

LV. Hemitrypa Phillips.

Differs from Fenestella in a reticulated superstructure, whose
meshes correspond in position and numbers to the zocecial aper-
tures, and rest on pillars which rise at regular intervals from the
moderate median keel of the branches. Sil.—Carb.

96. H. proutana Ulrich. (Fig. 201, f g.) Mississippian.

Superficial network of longitudinai bars, united by short transverse
bars, the former strong over the branches and weaker over the
interspaces of the underlying frond, the latter alternating in posi-

a

ae eee A el

BRYOZOA—CRYPTOSTOMATA. 147

tion on opposite sides of each weaker longitudinal bar. The
underlying branches have each a low carina with circular pores
with peristomes, on either side, and are connected by depressed
dissepiments half as wide as the branches.

Keokuk of Illinois and Iowa ; Warsaw of Illinois and Missouri ;
St. Louis of Kentucky.

LVI. RETEPORIDRA Nickles and Bassler.

Flabellate or undulating expansion with thickened margins, the
sinuous or zigzag non-carinate branches anastomosing at short
and regular intervals, producing a regular series of oval fenestrules ;
apertures in three to seven rows, non-celluliferous side not striated.

97. R. perundata (Hall). (Fig. 201, 4.) Mid-Devonic.

Fenestrules oval, irregular, non-celluliferous face angular or
carinated, celluliferous rounded; cell apertures in from three to
five ranges.

Hamilton of Western New York, etc.

LVII. ARCHIMEDES Owen.

Like Fenestella, but spirally wound and supported by a solid
calcareous central axis, which is often the only part remaining
intact.

98. A. communis Ulrich. (Fig. 205, 0’.) Mississippian.

Central axis or ‘‘screw”’ long, slender (I to 2 mm. in diameter)
and uniformly coiled, 7 or 8 volutions in 20 mm., the fenestrated
portion forming an angle of from 85 to 90 degrees with axis. (A.
intermedius Ulrich makes an angle of 72 degrees and has some-
what fewer whorls. A. swallowanus varies from 2.8 to 6.7 mm.
in diameter, and has an average of 5 volutions to 20 mm., the
angle of divergence of the fenestrated portion being 85 degrees.
A. proutanus Ulrich has from § to 7 volutions in 20 mm., and an
angle of 65 degrees for the fenestrated part. It is somewhat
thinner than A. communis.)

Chester of Kentucky and Illinois.

99. A. wortheni (Hall). (Fig. 205, a.) Mississippian.

Screw large and coarse (5 to 10 mm. in diameter), volutions
either right- or left-handed, from 5 to 6 in 50 mm., fenestrated
portion diverging at an angle of about 65 degrees. Zocecia

separated by strong spinose carina.

W arsaw of Illinois.

148 NORTH AMERICAN INDEX FOSSILS.

100. A. laxus Hall. Mississippian.
Very loosely coiled, axis formed of thickened edge of frond, one

volution in 25 mm. or more; angle of fenestrated portion acute.
Chester of Illinois and Kentucky.

101. A. sublaxus. (Fig. 205, 0.) Mississippian.
About half the size of the preceding.
Chester of Illinois.

102. A. terebriformis Ulrich. Mississippian.
Differs from A. communis in being more slender, with from 3 to
4 volutions in 20 mm. In coiling resembles A. /azus. Angle of
divergence 60 to 65 degrees.
Chester of Illinois and Kentucky.

LVIII. Potypora McCoy.
Differs from /enestella in having from two to eight rows of
zocecia on a branch, and the median keel reduced to a row of
strong nodes or tubercles, or absent altogether. Sil.—Carb. |

Fic. 204. Polypora incepta with non-celluliferous and celluliferous faces enlarged.

103. P. incepta Hall. (Fig. 204.) Siluric.
Branches regularly dividing with flexuous strie on the non-

celluliferous side, and several strong ridges separating the three or,

BRYOZOA—CRYPTOSTOMATA. 149

four rows of oval and alternating apertures, on the celluliferous
side; dissepiments thin, scarcely thickened at junction with
branches.

Rochester shale of New York and Canada.

104. P. fistulata (Hall). Mid-Devonic.
Two to three rows of apertures with strong peristomes; fenes-
trules oval, dissepiments expanding at the ends.
Hamilton of New York and Ontario.

105. P. shumardi Prout. (P. cultellata Hall). Mid-Devonic. |
_ Strong branches united by their dissepiments, forming narrow
_ fenestrules on celluliferous side, where branches are marked by
_ sharp nodes, and have from three to seven ranges of apertures ;
reversed side with broad oval fenestrules, and a faint keel or nodes,

: or smooth.
~ Hamilton of Falls of the Ohio.

Sconce os et:
WE a * N
se

Fic. 205. a, Archimedes wortheni, X % ; 6, A. sublaxus, showing fenestrated por-
_ tions, X % ; 6’, A communis, two specimens, * % ; c, Polypora submarginata, obverse
face, X4%4 ; d, Lyropora quinconcialis, poriferous face, 4%, a’, obverse side of basal
support, xX % ; ¢, Thamniscus furcillatus, obverse face, K % and <9;/, Pinnato-
pora conferta, KX % and X 4%; g, Ptilopora cylindracea, obverse face, * % and
4%; 4, Diploporaria bifurcata, X 4%; 1, Arthrostylus obliquus, lateral and non-
- celluliferous aspect, <9; /, Helopora spiniformis, x % and <9; &, Arthroclema
_ billingsi, frond, * % 3 1, A. armatum, segment of primary series with articulating
socket, X % and X9. (After Ulrich. ) gid hina :

150 NORTH AMERICAN INDEX FOSSILS.

106. P. submarginata Meek. (Fig. 205, c.) Carbonic.
Branches convex with a row of spines or tubercles, and five
ranges of apertures; five or six apertures to a fenestrule, the latter
irregular, elongate oval; dissepiments thin.
Upper Coal Measures of Nebraska, Iowa and Illinois.

LIX. Tuamniscus King.

Branches like those of Polypora, but bifurcating more freely and
rarely or not at all connected by dissepiments. Sil.—Carb.
107. T. furcillatus Ulrich. (Fig. 205, ¢.) Mississippian.

Branches small, with three to four ranges of apertures, with con-
tinuous or discontinuous low ridges between.

A characteristic species of the Chester group of Illinois and

Kentucky.
LX. Lyropora Hall.

Flabellate, the fenestrated portion spread between the arms of
a non-poriferons U- or V-shaped calcareous support, which is free
or pedunculate at the base; zocecia in from two to five ranges; no
median keel. Miss.
108. L. quincuncialis (Hall). (Fig. 205, d.) Mississippian.

U-shaped support narrow oval in cross section; fenestrules ir-
regularly oval; two or three ranges of apertures ; stout dissepi-
ments, which, on the non-celluliferous side, are often stronger than
the branches, forming transverse ridges.

Chester of Illinois and Kentucky.

-LXI. FEenestraria Prout.
Differs from Fenestella in having four rows of apertures, two on
each side of prominent keel. Miss.
109. F. sancti-ludovici Prout. Mississippian.
Branches with strong central carinz dilated into tubercles at
intervals; fenestrules oblong, subquadrangular; two ranges of
apertures on each side of carina; dissepiments about two-thirds the

width of the branches.
Warsaw and St. Louis of Missouri and Illinois.

LXII. PInNATOPORA Vine.

Small, delicate stipe, and short, free lateral branches given off at
regular, intervals ; apertures in two rows on one face only, separ-
ated by a moderate median keel. (Glauconome of authors.)

Dev. — Carb.

BRYOZOA—CRYPTOSTOMATA. I51

110. P. carinata (Hall.) (Glauconome carinata Hall.) (Fig. 206.)
Devonic.
Small, with broad central rachis, and alternating thin, short
lateral branches; non-celluliferous face with three prominent carine ;
apertures circular, with comparatively
strong peristomes and prominent carine
between the ranges.
Hamilton of Western New York, etc.

111. P. conferta Ulrich. (Fig. 205, f.)
- Mississippian.
Central rachis, and branches more nearly
of the same width; branches nearly op-
posite close-set; two ranges of close-set
pores on rachis and branches, separated
by low ridges.
Keokuk of Iowa and Illinois.

Fic. 206. /innatopora LXIII. Priropora McCoy.
carinata X 6. (After Hall

Differs from the preceding in having the
_ and Simpson. )

stipe much stronger than the oblique lat-
eral branches, which are occasionally and irregularly united by
_dissepiments. Dev.—Miss.

112. P. striata Hall. Devonic.
Branches rigid, diverging at angles of 45 degrees, and separated

by a space twice their width; dissepiments thin, irregular ; aper-

_ tures in two ranges.

Hamilton of Western New York and Ontario.

113. P. cylindracea Ulrich. (Fig. 205, g.) Mississippian.
Differs from the preceding in having a row of hollow nodes and
a median ridge on the rachis, and a similar row without the ridge
on the branches, and very thin, depressed, regular dissepiments.
Keokuk of Iowa and Kentucky.

LXIV. DrreLtoporariaA Nickles and Bassler.

Like Pinnatopora, but without the lateral branchlets. Miss.—
Coal Meas.

114. D. bifurcata (Ulrich.) (Fig. 205, .) Mississippian.
Small, cylindrical stipes (0.3 mm. in diameter) bifurcating at

152 NORTH AMERICAN INDEX FOSSILS.

regular intervals; apertures in two ranges on sides of stipe; re-
verse of branches finely striated.
Chester of Illinois, etc.

LXV. ARTHROSTYLUS Ulrich.

Bushy, dichotomously divided branches which consist of nu-
merous, exceedingly slender, equal subquadrate segments, united
by terminal articulations; one face longitudinally striated, the

other three (sometimes less) with a linear series of apertures generally

between longitudinal ridges. Ord.

115. A. obliquus Ulrich. (Fig. 205, z.) Ordovicic.
Segments needle-shaped, about 4 mm. long; subquadrangular
in section (0.2 x 0.15 mm.) slightly expanding to extremity;
apertures oblique, lower border prominent; no ridges between
ranges. :
Stones River of Minnesota.

LXWViI. : Hecopora Hall:

Differs from preceding in its larger segments, which have zocecial
apertures on all sides. Ord.—sil. a8

116. H. spiniformis (Ulrich). (Fig. 205, 7.) | Ordovicic.
Segments 5 to 10 mm. in length, obtusely pointed at the ends;
apertures oblique on all sides, in from : .
8 to 16 longitudinal ranges, and sep-
arated by slightly elevated lines.
Stones River of Tennessee and Illi-
nois.

117. H, fragilis Hall. (Fig. 207.)
Siluric.
Swollen at one end, apertures oval

or subangular, having a spiral direc-

tion around the stipe; length 5-6 mm.
Clinton and Niagara of New York and Ontario. -

Fic. 207. Helopora fragilis,
natural size and enlarged.

LXVII. AkTHROCLEMA Billings. —

Segments celluliferous on all sides, articulated laterally and termi-
nally in a pinnate manner; apertures oval in series between longi.
tudinal ridges. Ord. ‘H¢

ee ee ee ee ee ee ee ee a Se ae ee eee ee ee

BRYOZOA—CRYPTOSTOMATA. 153

118. A. armatum Ulrich. (Fig. 205, 2) Ordovicic.
Of three sets of joints, secondary and tertiary more slender
than primary which have sharply-defined articulating sockets, and
small apertures in six ranges with strong spines near each; sec-
ondary segments with apertures in five or six ranges between
strong ridges, and with lower lip spiniform.
Trenton of Minnesota, etc.
119. A. billingsi Ulrich. (Fig. 205, 2.) Ordovicic.
Primary segments 3.5 to 4 mm. long, each with two secondary
segments (4 mm. long) upon each side (4 in all), the succeeding
- ones 2 mm. long; apertures subquadrate, 6 in 2 mm,
Trenton of Canada.

LXVII1. Nemarorora Ulrich:

Slender, ramose, with pointed basal extremity, not jointed ; sub-
tubular zocecia arranged radially around one or two minute axial
tubes, with oval or subcircular apertures, and peristomes generally
in linear series between longitudinal ridges. Ord.—Dev.

120. N. ovalis Ulrich. (Fig. 208, a.) Ordovicic.
Bifurcating at intervals of 2 mm., diameter 0.3 too.4 mm. ; large
oval apertures, peristomes connected by short ridges, in four or
_ five ranges.
Trenton of New York, Canada, and Minnesota,

LXIX. RuomsBopora Meek.

Slender, non-articulate, and solid branches; apertures in longi-
tudinally or diagonally intersecting series; rhombic or diagonal
_vestibules, in the region of which the zocecia are thick walled ;
| acanthopores sometimes of two types, large and small. Sil.—
Carb.

121. R. tenuirama Ulrich. (Fig. 208, 2.) _ Mississippian.
Branches 0.4 to 0.5 mm. in diameter; apertures oval, between
slightly flexuous longitudinal ridges, carrying both large and small
_ spines.

Chester of Illinois and Kentucky.

122. R. lepidodendroides Meek. ~ Carbonic.
_ Average diameter of branches 1.75 mm., largest 3 mm.; zocecia
in regular quincunx order, oval, with rhombic vestibules, margined
by a single or double row of spiniform tubuli, with a large spine
at the angle.

154 NORTH AMERICAN INDEX FOSSILS.

Coal Measures of Nebraska, Kansas, Missouri, Iowa, Illinois,
and Ohio. Rather common.

LXX. Ca:Loconus Ulrich.
Simple hollow expansions from an attenuated striated base ;
zocecia short, with well developed hemisepta, and apertures in
diagonally intersecting series. Miss.

Fic. 208. a, Nematopora ovalis, K % and X 9; 6, Rhombopora tenuirama, K % and
6 and 12 (07, 6”) ; c, Coeloconus granosus, X ¥% and x 6; ad, Bactropora simplex, X
4 and X 6; e, Streblotrypa nicklesi, X ¥% and surface and section, « 9 ; f, Escharopora
subrecta, basal portion, &X 4%; g, Arthropora simplex, X %, and surface X 9g, and
xX 18; 2, Stictoporella cribrosa, K %, and portion X 9; 2, Rhinidictya mutabilis, X
y% and X 4%; 7, Phyllodictya varia, X% (7 ), surface X 4% (/” ), and portion
9 (:7" )... AM after Ulrich: )

123. C. granosus Ulrich. (Fig. 208, c.) Mississippian.
Lined on inside with thick epitheca; apertures oval to subcir-
cular, the interspaces with granules ; basal portion with vertical
granulose ridges between the oval apertures.
Chester of Illinois.

et i ee i _

eV

—

eo ee ee a ee ee Ss eee

BRYOZOA—CRYPTOSTOMATA. Isc

LXXI. Bactrropora Hall.

Like Rhombopora, but simple or only slightly branched, and
with lower extremity pointed. Dev.—Miss.

124. B. simplex Ulrich. (Fig. 208, d.) Mississippian.
Surface with transversely elongated monticules, appearing often
like annulations ; apertures oval to subcircular ; narrow interspaces
with a single or double row of small acanthopores; average size
I.5 mm. in diameter by 18 mm. in length. i
Keokuk of Iowa, Illinois, and Missouri.

LXXII. StrresBiotrypea Ulrich.

Ramose, slender, and solid, frequently bifurcating, with long
tubular zocecia diverging from the center, with hemisepta (inferior
one best developed) and regularly elliptical
apertures with peristomes usually arranged
in longitudinal series; one to fifteen small
pits below the apertures, and occasionally
very small acanthopores.

; as 209. 5 lt 125. S. hamiltonensis (Nicholson). (Fig.
Oe ca aie 209.) ; Devemc:
son). Apertures between prominent wavy lon-
gitudinal ridges, alternating in position in
adjoining ranges, and having two angular pits between the aper-
tures of each row.
Hamilton of Western New York and Ontario.

126. S. nicklesi Ulrich. (Fig. 208, ¢.) Mississippian.
Apertures small, between three straight longitudinal ridges,

alternating; peristomes strongest anteriorly; interspaces with

from nine to fifteen small pores in two or three rows.
Chester of Illinois and Kentucky.

LXXIII. Pritopictya Lonsdale.

Simple, unbranched, lanceolate or falciform frond, articulating,
with small basal expansion, and having zocecia on both sides except
the margin; zocecia narrow oblong-quadrate and arranged longi-
tudinally in the young and with additional variously formed zocecia
added in the adult; walls of vestibules thick, solid, and with a
double row of minute dots. Ord.—Dev.

156 NORTH AMERICAN [INDEX FOSSILS.

127. P. nebulosa (Hall). Lower Devonic.
A thin, leaf-like expansion from .a thickened, narrow, striated
_ base; rows of cells increase rapidly by intercalation; rounded
monticules, separated by about 3 mm. from each other, mark the
surface.
Helderbergian of New York, etc.

LXXIV. Escuaropora Hall.

Like Pilodictya, but with the apertures in decussating series,

and surrounded by sloping hexagonal areas. Ord.

128. E. falciformis (Nicholson). Ordovicic.
Falciform, narrow and long, apertures rhombic to oval, in diago-
nal curved series.
Lorraine of the Cincinnati region and Tennessee.

129. E. subrecta (Ulrich). (Fig. 208, 7) Ordovicic.
Elongate narrow, straight or curved, flattened and tapering
below ; apertures oval, between regularly wavy ridges, which
regularly approach and diverge; adult portion with a few meso-
pores, as in Stvedlotrypa.
Black River of Minnesota, Iowa and Wisconsin.

130. E. pavonia (d’Orbigny). Ordovicic.
Expanded, more or less irregular ; apertures oval to subcircular,

with hexagonal vestibules and low, obscure monticules of slightly

larger cells ; arrangement of cells in curved lines as in £. falciformis.
Lorraine beds of the Cincinnati region and Tennessee.

LXXV. CLATHROPORA Hall.

Anastomosing branches forming regular network with round or
oval fenestrules and pointed articulating base, apertures on both
sides usually subquadrate, arranged longitudinally. Sil.Dev.

131. C. frondosa Hall. (Fig. 210.) Siluric.
Flabellate or funnel-shaped fronds; apertures rhomboidal or
oblong quadrangular, opening obliquely upward.
Clinton of Ohio; Niagara of Western New York and Ontario.

LXXVJ. ARTHROPORA Ulrich.

Bushy, of numerous articulating equal segments spread in a
plane; apertures on both sides, elliptical, surrounded by delicate

ee eee a eee ee

BRYOZOA—CRYPTOSTOMATA. 157

peristomes, and with interspaces marked by variously disposed
thread-like ridges and a row of minute papillae. Ord.

Fic. 210. Clathropora frondosa, with portions of celluliferous face enlarged. (Hall. )

132. A. simplex Ulrich. (Fig. 208, g.) . Ordovicic.
Jointed, but generally found in isolated unbranched segments,
I2 to 19 mm. long and 1 to 1.8 mm. wide; margins free from
apertures; longitudinal wavy and papillose ridges, alternately con-
verging and diverging, surround the apertures.
Stones River and Black River of Minnesota and Iowa.

133. A. shafferi Meek. Ordovicic.
Segments flat, branching repeatedly ; apertures oval, rather dis-
tant; interspaces with from one to four wavy raised lines, visible
_ under high power.
Lorraine of the Cincinnati region.

LXXVII. StTIcropPporRELLaA Ulrich.

Branching and leaf-like, nonarticulate from spreading base;
_ zocecia on both sides, with primitive portion tubular, usually long,
generally without any septa, except occasionally an inferior one ;
orifices at bottom of wide sloping vestibule; thick walled, untabu-
lated mesopores on margins of frond and between apertures. Ord.
134. S. cribrosa Ulrich. (Fig. 208, %). | Ordovicic.
Fenestrules at irregular intervals and varying greatly in size and
form; apertures small, subcircular or elliptical, with sharply defined

158 NORTH AMERICAN INDEX FOSSILS.

polygonal or circular vestibules and numerous small mesopores,
which often completely surround the zocecia.
Stones River and Black River of Minnesota.

‘. LXXVIII. InrrRapora*Hall.

Ramose from a spreading base with compressed and dichoto-
mously divided branches; zocecia on.both sides, tubular, at first
parallel to mesotheca, then bending abruptly outward; apertures
oval, with peristome; minute angular pits, the openings of tabu-
lated mesopores, in the interspaces, sometimes closed by calcareous
tissue. Dev.—Miss. ;

135. I. puteolata Hall. By tt ee Devonic.

Flattened, dichotomously branching ond: from spreading base;
width usually 2 to 4 mm. but sometimes 20 mm. or more; ava
apertures closely and irregularly disposed,. frequently in contade

_ with strong peristomes, interspaces and margins with angular pits

or mesopores.
Hamilton of Falls of the Ohio.

LXXIX. CoscINnELLa Hall.

Explanate fronds of anastomosing branches from spreading
base; zocecia on both sides of frond, tubular, resting upon the
mesotheca, with rather long direct vestibules and irregularly dis-
posed circular apertures; spaces between vestibules and margins
of fenestrules occupied by numerous tabulated mesopores which
open on the surface as fine pits. Dev.

136. C. elegantula Hall and Simpson. Devonic.
Fenestrules irregular in form, size and distribution; apertures
circular, with pronounced peristomes, generally separated by a
single series of mesopores only.
Hamilton of Ontario.

LXXxX. Rurnipictya Ulrich.

Bifoliate ramose, of narrow compressed bifurcating straight-
edged branches with parallel margins, attached by continuous ex-
panded base; apertures between longitudinal, slightly elevated or
flexuous ridges, carrying a crowded row of small blunt spines;
space around apertures sloping to summit of ridges. Ordovicic.

137. R. mutabilis Ulrich. (Fig. 208, z.) Ordovicic.
Branches commonly from 2.3 to 3.2 mm. wide, dividing at inter-
vals of from 7 to 16 mm.; non-celluliferous margins often almost

.

ee ee ae Se eS vq

—— oo

Rte oe. ee ci

BRYOZOA—CRYPTOSTOMATA. 159

wanting; zocecia in I4 or I5 rows, the intervening ridges carry-
ing granules; apertures direct.
Stones River to Trenton, Minnesota and Iowa.

138. R. trentonensis (Ulrich). Ordovicic.
Marginal apertures generally somewhat larger; interspaces thin,
without granules; superior hemiseptum not developed.
Stones River of Tennessee, Minnesota, Wisconsin and Illinois.

LXXXI. PHyttopictya Ulrich.

Bifoliate, simple or irregularly branched, from an expanded at-
tached base; long tubular zocecia with diaphragms, but without
hemisepta, bending very gradually outward from central axis, form-
ing oblique apertures with posterior edge lip-like ; wide subsolid
interspaces, traversed vertically by minute tubuli, which appear as
papillz upon the surface. Ord.

139. P. varia Ulrich. (Fig. 208, 7.) Ordovicic.

Leaf-like expansions, surface with smooth or finely granulated
striate maculz at 4 mm. intervals; apertures pyriform, oblique,
with peristome strong posteriorly; granulose vertical ridges be-
tween the apertures. |

Black River of Minnesota.

LXXXII. Pacuypictya Ulrich.

Bifoliate, ramose, of narrow, bifurcating stipes with parallel
margins; or irregular undulating fronds with acute non-poriferous
margins; surface with small maculez, surrounded by apertures
slightly larger than the average ; marginal rows of apertures some-

_ times larger than average; zocecia thin-walled, elliptical or sub-

quadrate, separated by small vesicles; vestibules direct, thick-

walled, ring-like in section ; interspaces with minute tubuli; one or

more diaphragms present. Ord.—Sil.

140. P. fimbriata Ulrich. (Fig. 214, 2.) Ordovicic
Branches from 2 to 5 mm. wide, with subparallel, wavy or ruffled
non-poriferous margins; apertures in rows in central area, between
lines of minute pores.
Black River of Minnesota and Stones River of Tennessee.

141. P. acuta (Hall). Ordovicic.
Differs from the preceding in its smooth non-poriferous margin

160 NORTH AMERICAN INDEX FOSSILS.

and the greater interspaces between the apertures, which are much
larger near the margin than at the center.
Trenton of New York, Kentucky, Iowa, Minnesota and Manitoba.

142. P. crassa (Hall). Siluric.
Branches 2.5 to 3 mm. wide; cells elliptical, with strong peris-
tomes and separated by slightly wavy ridges; a marginal row of
larger apertures, with a non-celluliferous striated margin. |
Clinton of New York, Ohio and Ontario; Niagara of New
York; Anticosti group of Anticosti.

LXXXIII. Cystropictya Ulrich.

Ramose, of two layers of cells grown back to back, cross sections
elliptical ; subparallel margins non-poriferous ; apertures subellip-
tical in linear series between longitudinal ridges, with lunarium on
marginal side of apertures ; interspaces finely striated, granulose
or smooth. Worn specimens show pits and cells. Dev.-Carb.

143. C. gilberti (Meek). (Fig. 214, 0.) Devonic.

Repeatedly branching rows of apertures and separating ridges,
increasing rapidly by interpolation on the branches.

Onondaga to Hamilton
of Ohio and Ontario ; Ham-
ilton of Falls of the Ohio
and Utica, Indiana.

144. C. hamiltonensis Ul-
rich. Devonic.
Branches bifurcating, 2.5

to 3 mm. wide; apertures

nearly circular, alternating
in adjoining rows.

Hamilton of Iowa, IIli- Fic, 211. Cynediiye incisurata. a, natural
aoic AM icroasine | estarn size, and 4, portion enlarged. (After Hall and
? : Simpson. )

New York and Manitoba.

145. C. incisurata (Hall). (Fig. 211.) Devonic.
Branches bifurcating from 2 to 6 mm. in width, margins parallel
or slightly diverging; ridges continuous to the margin, where they
often cause denticulations, slowly increasing by intercalation ;
apertures circular to oval or irregular ; lunarium strong.
Hamilton of Centraland Western New York and Ontario.

ee en ee

and Simpson. )

BRYOZOA—CRYPTOSTOMATA. 161

LXXXIV. DicHorrypa Ulrich.

Like Cystodictya, but in form a large, thin, bifoliate expansion,
with solid maculz on surface. Dev.—Miss.

146. D. lyroides Ulrich. (Fig. 214, c.) Mississippian.
Frond free, lyre-shaped, with thick, solid, rounded margins;

surface with broad monticules, with solid circular or substellate

maculz, bordered by larger cells.

St. Louis of southern Kentucky.

LXXXV. Taniopora Nicholson.

Differs from Cystodictya in having a strongly elevated, longitudinal
central ridge on each face, making cross-section somewhat rhom-

boidal. Dev.

147. T. exigua Nicholson. (Fig. 212.) Devonic.
Non-celluliferous margin comparatively narrow, carinz on main
stem and branches strong, rounded; apertures circular, with strong
peristomes.
Hamilton of Western New York and Ontario.

148. T. penniformis Nich-
olson. Devonic.
Keel broader and more

strongly elevated, and non-

celluliferous margin wider,
than in the preceding; aper-
tures arranged in oblique
transverse rows; peristomes

Fic. 212. TZeniopora exigua. a, fragment pronounced.
1; and 4,-small portion 6. (After Hall Hamilton of Western

New York and Ontario.

LXXXVI. Coscinitum Keyserling.

Differs from Cystodictya in having the branches inosculating at
short intervals, so as to produce broad fronds, perforated at rhyth-
mic intervals by elliptical or circular fenestrules. Dev.—Carb.

149. C. cribriforme Prout. Devonic.
Cells tubular, very oblique, the apertures trilobate, or when

- worn, arched or subtriangular, closely and irregularly disposed ;
_ fenestrules varying greatly in size and distance from each other;
_ lunarium elevated. |

Hamilton of Falls of the Ohio and Utica Ind.

162 NORTH AMERICAN INDEX FOSSILS.

150. C. latum Ulrich. (Fig. 214, @.) Mississippian.
Branches wider than in preceding (4-5 mm.); cell apertures ele-
vated and disposed in diagonal lines.

Burlington of Illinois and Iowa.

LXXXVII. AcrROGENIA Hall.

Segmented, arising from cylindrical rootlets, two segments from

truncated ends of preceding one,

the base, later becoming flat-
tened and bearing apertures in
linear series, separated by ridges,
largest in marginal row; lunarium
prominent. Dev.

151. A. prolifera Hall. (Fig.
243.) Devonic.
Apertures small and circular,

with weak peristomes, and in

rows, separated by continuous
longitudinal ridges.

Hamilton of Centraland West-
ern New York.

LXXXVIII. Prismopora Hall.

Ramose, of triangular bifurcat-
ing or trifurcating branches,
sometimes anastomosing and
forming clumps; faces subequal,
usually slightly concave, edges
sharp, serrated, or wavy; the zo-
cecia arising from mesothecze

each obconical and striated at

Fic. 213. Acrogenia prolifera; (a)
frond, X 1, and (4) small fragment en-
larged, <6. (After Hall and Simpson. )

which radiate from center to margins; apertures sometimes on
summit of small papille ; interzocecial spaces vesiculate, often solid

on the surface. Dev.—Carb.

152. P. triquetra Hall.

Devonic. —

Faces of branches from 3 to 6 mm. wide, concave, the apertures
in diagonal transverse rows from center of face; peristomes promi-
nent posteriorly; relatively wide non-celluliferous margins; bifur-

cating branches frequent.
Hamilton of Falls of the Ohio.

Se ee ee ee Pees eS oe ee

_ » ed On

ee ee ee ee
oo

BRYOZOA—CRYPTOSTOMATA. 163

LXXXIX. ScALARIPORA Hall.

Like Prsmopora, but with faces of triangular branches crossed
by salient transverse ridges. Dev.

153. S. scalariformis Hall. Devonic.
Faces of branches 3.5 to 4 mm. wide, ray concave, the transverse
ridges at intervals of 1.5 mm.and having a height at center of face
of I mm.; celluliferous; apertures circular, with pronounced per-
istomes, irregularly disposed.
Hamilton, Falls of the Ohio.

pA Gisenerbieh Ulrich.

A thin expansion, with salient ridges or crests on both surfaces,
uniting into cup-shaped cavities; 1idges sometimes pronounced
and leaf-like, composed of two layers of zocecia arising from a
mesotheca; upper surface with solid macule or dimples. Miss.

154. G. sagenella (Prout). (Fig. 214, ¢.) Mississippian.
Cups elongate, often groove- or channel-like ; summit of ridges

OTT
ai ae

y

a

Fic. 214. a, Pachydictya fimbriata, K % and X 4%; 6, Cystodictya giiberti,
x 3; ¢, Dichotrypa lyroides, fragment showing base, & % ; d, Coscinium latum, K 4 ;
e, Glyptopora sagenella, KX %; f, Evactinopora radiata, basal and lateral views, « % ;
g, £. grandis, X %; h, Actinotrypa peculiaris, surface, KX 4%; 1, Worthenopora
spinosa, fragment showing spines, 41%, and portion of same enlarged, 14; 4,
Stictotrypa punctipora, X %, and fragment, & 2, (After Ulrich and Hall.)

164 NORTH AMERICAN INDEX FOSSILS.

sharp, non-poriferous ; apertures subcircular, with unequal peri-
stomes.
Keokuk of Iowa; Warsaw of Illinois.

155. G. (Phractopora) megastoma (Ulrich). Mississippian.
Cups large; apertures large, subcircular, most pronounced at
angles of cups; maculz conspicuous often on broad elevations;
_ apertures larger near macule; generally only fragments of cups
found.
Keokuk of Illinois and Iowa; Waverly of Ohio.

XCI. Evactinopora Meek and Worthen.

Free, of four or more vertical leaves of cruciform or stellate
arrangement ; rays united, thick and nonporiferous in basal por-
tion, free, with subcircular apertures on both sides in upper part;
vesicular interspaces, solid at surface. Miss.

156. E. grandis Meek and Worthen. (Fig. 214, ¢.) Mississippian.
Large, transverse diameter probably 7 inches; rays 4; apertures
small, regularly arranged in quincunx order, separated by about
twice their width.
Burlington of Iowa and Illinois.

157. E. radiata Meek and Worthen. (Fig. 214,/) Mississippian.
Rounded below, above of eight solid subcarinate rays, with cir-

cular pores on thin portions of rays ; greatest diameter, from tip to

tip of rays, 22.5 mm.
Keokuk of Missouri and Kentucky.

XCII. Actinotrypa Ulrich.

A thin, bifoliate expansion, with 8 to 10 vertical, septa-like ridges
in aperture, extending along sides of vestibule. Miss.

158. A. peculiaris (Rominger). (Fig. 214, 4.) Mississippian.

Apertures regularly arranged in diagonal intersecting series,
floriform from tooth-like projection of pseudo-septa; peristomes
raised; minutely punctured or granular subcircular macule char-
acterize the surface at variable intervals.

Keokuk of Missouri, lowa and Illinois.

XCIII. WortHEenopora Ulrich.

Bifoliate, branching or palmate, with regularly arranged elon-
gate rhomboidal zocecia with semi-elliptical apertures, the trun-

|
:
:
|

BRYOZOA—CRYPTOSTOMATA. 165

cated posterior margin somewhat raised; line of junction between
zocecia marked by ridge; plain, elongate triangular space below
aperture. Miss.

159. W. spinosa Ulrich. (Fig. 214, 2.) Mississippian.
: Elongate branches 3 or 4 mm. wide, 0.5 to 0.8 mm. thick;
acutely elliptical in section; margins subparallel, with a series of
slender spines, pointing obliquely upward.
Keokuk of Illinois and Iowa.

XCIV. LICHENALIA Hall.

Subcircular, unilaminar expansion, with prostrate, elongate sub-
rhomboidal zocecia, having direct subtubular vestibules and rounded
apertures with peristome much elevated on posterior side. Sil.

160. L. concentrica Hall. (Fig. 215.) Siluric.
Cup-form in young, flattened at maturity, and variously contorted
from irregular growth or accident ; concentrically striate and rugose

Fic. 215. Lichenalia concentrica, with enlargement of fragment. (After Hall.)

_ surface on non-celluliferous side; apertures in concentric lines,
opening on summit of elevated pustules.
Niagara of New York, etc.

XCV. DIAMEsopora Hall.

Ramose, of hollow stems, lined internally by an epitheca ; simple
_ hexagonal or rhomboidal zocecia with oval orifices in anterior half

166 NORTH AMERICAN INDEX FOSSILS.

forming with growth tubular vestibules, separated. by compact™or
horizontally laminated interspaces; peristomes equally elevated,
or highest posteriorly. Siluric.

161. D. dichotoma Hall. (Figs. 216, a, 216, 0.) Siluric.
Regularly bifurcating, generally filled with rock matrix, or
crushed; interior of hollow branches, transversely striated, apertures
in regularly ascending spiral lines, strongly
elevated posteriorly.
Niagara (Rochester) of New York, etc.

XCVI. Sticrotrypa Ulrich.

Ramose, not pointed at the base;
branches dichotomously dividing, narrow, Fc. 216, 2. Diamesopora
dichotoma enlarged showing
oblique peristomes.

compressed, with circular or elliptical aper-
tures, evenly elevated peristomes, and flat

or concave interspaces of horizontally laminated solid tissue. Sil.

162. S. punctipora Hall. (Fig. 214, 2.) Siluric.
Flattened, bifurcating; apertures min-
ute, punctiform with elevated peristomes
arranged in diagonal series.
Niagara (Rochester) of New York,etc.

XCVII. PaLtescuara Hall.
Thin incrustations with short, direct, gen-
erally thin-walled zocecia, with long, hex-
agonal or polygonal apertures. Ord.—Dev.

163. P.incrustans Hall. Lower Devonic.
On shells (Spz2fer perlamellosus) or other

Fic. 216, 6. Dzameso- onal in contact; walls thick, sometimes
orp er kvame, natoral B26). wich obbase spinose processes at the angles.
showing axial hollow.

Helderbergian of New York, etc.

MESOZOIC AND CENOZOIC SPECIES.

OrpER CYCLOSTOMATA.
XCVIII. FiriFascicera d’Orbigny.

Irregularly branching, repent zoaria, with apertures in clusters
of from two to five or more. Cret.—Tert.

bodies; 0.1 to 1.0 mm. thick; cells polyg- -

|
.
7
|
|

— ee a

BRYOZOA—CRYPTOSTOMATA. 167

Fic. 217. @, Filifascigera megera, <9, top and side views; 4, Dzscosparsa va-
rians, surface, X 6; c, Cavaria dumosa, portion of branch, « 4%; c’, fragment
showing gonocyst, 10; ¢’’, broken gonocyst to show tubes, 20; d, Certopora mt-
cropora, complete mass, 3, and surface, 10; e, Bzflustra torta, surface, X 10;

Ff, Onychocella digitata, surface, 10; and single zocecium showing lunarium-like

process, X 15; g, Membranipora oblongula, surface, K 10; h, M. rimulata, surface
of small-celled variety, & 10; 7, Adeonellopsis umbilicata, surface, X 8; 7, Schizopo-
rella informata, entire mass, XK 1% ; 7’, surface of same, & 8. (After Ulrich and Md.
Geol. Surv.)

164. F. megera Lonsdale. (Fig. 217, @.) Cretacic.
Minute, encrusting, with attached portion flattened, clusters of
tubes rising at nearly right angles from attached part.
Rancocas formation of New Jersey.

XCIX. Discosparsa d’Orbigny.
Like Lerenicea, but the obconical or cup-shaped zocecia attached
by center of baseonly. Cret—Tert.

165. D. varians Ulrich. (Fig. 217, 2.) Cretacic-Eocenic.
Apertures more or less radially arranged about small depressed,
smooth macule ; ringlike peristomes ; interspaces solid.
Common in Upper Cretacic (Rancocas) at Vincentown, N. J.,
and in the Aquia formation of Maryland.

C. Cavaria Hagenow.
Ramose, with cylindrical branches, the hollow axis divided by a
number of plates; apertures all around the stem, immersed and
with prominent peristomes. Gonocysts present.

i;
.
q :

168 NORTH AMERICAN INDEX FOSSILS.

166. C. dumosa Urich. (Fig. 217, c.) Eocenic.
A bushy mass of frequently and irregularly dividing and coa-
lescing branches I.5 to 3.0 mm. thick; surface with macule slightly
depressed, smooth or with mesopores ; gonocysts large rounded or
irregular inflations; axial hollow 0.2 to 0.4 mm., with partitions
incomplete. .
Aquia formation of Maryland.

CI. Cerropora Goldfuss.

Encrusting, massy, lobate, or ramose often in two or more
superposed layers of tubes; tubes, of one kind, subequal, in close
contact with amalgamated porous walls; apertures round or poly-
gonal over entire upper surface.

Abundant in Alpine Trias, less so in Jura, common in Cretacic;
Lert,

167. C. micropora Goldfuss. (Fig. 217, @.) Eocenic.
- Depressed globular, hollow beneath ; apertures polygonal varia-
ble in size. ;

Nanjemoy formation of Maryland.

CII. HeEtTERoporRA Blainville.

Generally ramose, sometimes of several layers of tubes; aper-
tures rounded, with raised peristomes ; mesopores numerous, angu-
lar, usually completely surrounding the zocecia or in clusters, their
orifices closed in perfect specimens. Structure as in Ceriopora.
Jura-Cret., abundant and Tert.—Recent rare.

168. H. parvicella Gabb and Horn. Cret.—Miocenic.

Branches round, irregular, often anastomosing, of several layers |

of cellules; apertures subregularly disposed with numerous round
mesopores, and marked peristomes. :
Upper Cretacic of New Jersey.
169. H. tortilis Lonsdale. Miocenic.
Apertures placed irregularly, with large irregular angular meso-
pores and thin walls.
Miocenic of Virginia and South Carolina.

OrpER CHILOSTOMATA Busk.

CIII. Brriustrra d’Orbigny.

Colony lamellose or ramose, cellules on sides in longitudinal
series, with slightly elevated peristomes, the anterior position partly

x ‘. =| fins Sa = bi eee ee
a ee a ae

BRYOZOA—CHILOSTOMATA. 169

membranous; the two layers of cells separate readily along the
median line. Cret.—Recent.

170. B. torta Gabb and Horn. (Fig. 217, ¢.) Cret.—Tert.
Small, of compressed branches, usually twisted; cellules in

longitudinal lines, usually in quincunx; close together; aperture

oval, about half of the cell surface, without lips or peristomes;

colony increases in width by interpolation of new rows of cells.
Rancocas of New Jersey and Aquia of Maryland.

CIV. OnycHoceLLta Waters.

Encrusting or erect, branches compressed, zocecia hexagonal
with raised margins (unless worn), oral openings semilunar or
crescentic ; scattered avicularian openings in pearshaped areas.
Cret._Recent.

171. O. digitata Morton. (Fig. 217, /) Cret.—Tert.

Branches compressed, acutely elliptical, bifurcating, somewhat
twisted, 2.5-3.0 mm. wide. Zocecia bounded by a slightly
impressed line, apertures in front of center. Small subcircular
cells (avicularia) on margins and below bifurcation.

Upper Cretacic (Rancocas) of New Jersey, Aquia of Maryland.

CV. MEmBRANIPORA Blainville.

Encrusting, irregular calcareous or subcalcareous expansions ;

_zooecia irregularly arranged or in rows, with variously shaped

apertures according to the degree of calcification of the front wall of

the zocecium. Cret.—Recent.

172. M. plebeia Gabb and Horn. Cretacic.
Encrusting, sometimes on O. digzfata, cells generally in radiating

_ lines, elongate to pyriform, separated by depressed lines; apertures

large; oral openings occupying the whole cellule.
Rancocas of New Jersey. “s

173. M. abortiva Gabb and Horn. eae Cathie Cretacic.
Cells elongate pyriform to suboval, irregularly arranged; aper-

_ ture occupying about half the cellule, nearly terminal oe acum-

inate in front and wide behind.
Common in the Upper Crétacic of Timber 5 ies — near
Mullica Hill, N; J: .

474. M. oblongula Ulrich: (Fig. ce etary go MAOCEnIC,

' Zocecial apertures in longitudinal series elongate ovate ‘to sub-

_ quadrate, about twice as long as wide, occupying entire cellule ;

170 NORTH AMERICAN INDEX FOSSILS.

walls generally thick, with numerous thin spines projecting in-
ward from them.
Choptank and Calvert formation of Maryland.

175. M. rimulata Ulrich. (Fig. 217, 4.) - Eocenic.
Zocecia hexagonal, arranged quincuncially with longitudinal
rows generally regular; apertures occupying entire cell, quite reg-
ularly ovate in form; interapertural space narrowed and rounded,
sometimes angular, often with depressed central line.
Aquia formation of Maryland.

CVI. ADEONELLopsis Macgillivray.

Encrusting with bulbous cells having subcircular to semicircular
opening, beneath which is a second circular or crescentic pore.
Cret.—Tert. .

176. A. umbilicata (Lonsdale). -(Fig. 217, z:) Miocenic.

Irregular nodose masses of numerous layers; zocecia irregular,
central and anterior portion elevated and outline of each marked
by a row of pores; upper front wall coarsely punctate; orifice
anterior, semielliptical, 2 smaller apertures on the proximal portion
of the cell. |

Chesapeake Group of Virginia and Choptank formation of Mary-
land. Common.

CVII. ScHIZOPORELLA Hincks.

Zoaria variable; zocecia urn-shaped, the front entirely calcified ;
orifice varying from semicircular to suborbicular, with a distinct
notch or sinus in the lower margin. Cret.—_Recent.

177. S. informata (Lonsdale). (Fig. 217, 7.) Miocenic,

Irregular botryoidal or nodulose masses of superposed layers of
zocecia, 20 to 40 mm. in diameter; cells with terminal subcircular
orifice with distinct peristome and deep and sharp proximal notch;
entire surface punctate; avicularia uncommon.

Chesapeake group of Virginia and Choptank formation of
Maryland.

Class Brachiopoda.

Brachiopods are marine animals secreting a shell of two pieces
or valves which may be calcareous or phosphatic or both. These
valves are dorsal and ventral in position and are usually of unequal
size, a larger, the pedicle or ventral valve and a smaller, the dvachial

2

a ees ese eee

MOLLUSCOIDEA—BRACHIOPODA. 171

or dorsal. They are usually attached to some foreign object, such
as rocks, etc., by a fleshy stalk, the pedicle (Fig. 219, 5); this pos-
terior prolongation of the animal’s body passes through an open-
ing, the delthyrium, or the more restricted foramen at the posterior
end ofthe pedicle valve. The shell is sometimes anchored by spines
and sometimes it is cemented to its support (Cvamza).

Fic, 218. Diagram of Spzrifer. (ABZ) longitudinal axis marking the height ;
(CD) transverse axis marking the width; (A) anterior (front) end; (2) posterior
(beak) end; (%) hinge line; (ca) cardinal area; (¢) cardinal extremities ; (d¢) del-
thyrium ; (#) umbo; (@) apex or beak,

The interior of the shell is lined by the mantle, a membranous
reduplication of the body wall, which is often studded with minute

-czeca or blind tubes which enter the perforations (tubules) of the

shell, thus giving the shell a punctate structure. The pedicle valve
is secreted by the ventral and the brachial valve by the dorsal
mantle lobe. In the Protremata the dorsal surface of the pedicle
secretes a third shellpiece, the de/tidium, or pedicle plate, which
unites with the posterior margin of the pedicle valve and continues
to grow anteriorly (Schuchertella, Fig. 276). In the Telotremata,
where this deltidium is absent, the extension of the ventral mantle

lobe effects the protection of that portion of the pedicle by a secre-

tion of two plates, the deltidial plates or de/farza which may unite
to form the pseudodeltidium. In some of the Neotremata (Ordicu-
loidea, etc.), a single plate, the /zs¢vzwm, forms between the apex of
the pedicle valve and the opening for the pedicle. In some forms
(Spzrifer) the delthyrium is filled by the deposition within the shell
of solid calcareous material. In extreme cases a tubular sheath, the
syrinx, is formed on this calcareous filling (Syvingothyris) (Fig. 436).

Externally the shell is marked with concentric lines (grow¢h
fines) which represent the successive stages of growth; as the shell

grows a new layer is added to the inside, projecting beyond the pre-

ceding layer, thus forming a “series of outcrops.” These growth

172 NORTH AMERICAN INDEX FOSSILS.

lines are more or less conspicuous. Besides this ornamentation,
shells frequently bear folds or plications radiating from the region of
the beak to the anterior portion of the valves (Spufer, Fig. 218,
Magellama, Fig. 219, 4-5). When these are fine they are gener-
ally spoken of as s¢riations. Frequently the striz alternate in size.
They may increase by intercalation or implantation of new ones
between the diverging older ones, or these latter may bifurcate.

(See Figs. 251 to 275 for variations).
of the brachial valve bears a much
larger fold called the smedian fold,
while the corresponding large depres-
sion on the pedicle valve is called the
median sinus (Spirifer, Fig. 409). In
some forms the sinus and fold are re-
versed in position (Avastrophia, Gypi-
dula, Enteletes, etc.), while in others
they are entirely wanting (Whitfield-
ella).

. The length or height of the shell is
the distance from the hinge line, or
line of junction of the valves, through
the middle of the shell to the opposite
edge or front (A-4 in Fig. 218). The
width is in the direction at right an-
gles to this or on a line extending

Frequently the median line

FIG.

219. 1, Delthyrium of
young Rhynchonella without delti-
dial plates; 2, the same at a later
stage with two triangular deltidial
plates ; 3, the same after completed
growth ; showing joining of deltidial
plates, and limitation of pedicle
opening to ventral beak (foramen);

from side to side of the shell (C—D in
Fig. 218). The dhzckness is in the
direction perpendicular to the plane
of length and width through the cen-
ter of the valves.

There is usually a flattened area at
the posterior portion of each valve between the dcak (a) and the
hinge line (h) and extending to the cardinal angles; this is the
cardinal area (ca in Fig. 218). The cardinal area of the pedicle
valve is the higher.

In the Articulata a pair of zeeth on the posterior portion of the
pedicle valve fit into corresponding sockets on the brachial valve.
Fitting between the teeth of the pedicle valve is a short prolonga-
tion of the brachial valve, the cardinal process (Fig. 261). Teeth and
sockets are usually absent in the Inarticulata. The dental sockets are

4, dorsal view of Magellania flaves-
cens, showing completed deltidial
plates de/; 5, profile of same; ws,
ventral (pedicle) valve; ds, dorsal
(brachial) valve ; 7, pedicle. (Af-
ter Beecher).

See eee ee eee

ey ee ete dee: i te ed a

6, adult loop of Zerebratalia obsoleta. (Af-

MOLLUSCOIDEA—BRACHIOPODA. 173

bounded on the inside by /znzge plates which are united above with
the cardinal process. Similar plates, the dental plates, bound the
inner side of the teeth; at times these unite before reaching the
bottom of the shell, thus forming a plate or cup upon which are
fastened the diductor, adductor and pedicle muscles. This cup is
called the spondylum (Gypidula).: In some genera (Mezista, etc.) a
free plate, of different origin, the shoe-lfter process, occurs in place
of the spondylium. The solid or excavated platforms in some of
the Atremata ( Z7zmerella, Fig.
226) are homologous to the
spondylium. A corresponding
structure sometimes occurs in
the brachial valve where it is
known as the cruralium. The
muscle areas are more deeply
impressed upon the posterior
portion of each valve. This
area in each valve is frequently
divided into halves by a ver-
tical plate or septum extending
from beneath the beak ante-
riorly, never reaching the

Fic. 220. 1, Dorsal valve of Zerebratu- front of the shell (Fig. 233, Ss).
lina septentrionalis with cirrated brachia at- Curving forward from the

tached; showing relation of calcareous loop posterior portion of the bra-
which is darkly shaded; 2, Centronelliform chial valve or ‘from the crura-
stage of loop of Dielasma turgidum X 6; 3, ,. i ‘

lium there is a pair of short

spirals and loop in Zygospira modesta K 21% ;
4, loop and crural plates of adult Dze/asma PYroOCesses, the cvura; to these
turgidum “ 4; 5, side view of same 4; jn many shellsare united more
or less complicated calcareous
ribbons, the Jdrachidia (Fig.
220, 2-6). When spirally coiled as in Speifer or Zygospira they
are called spzvala (Fig. 220-3).

The valves are opened and closed by muscular action. The
pedicle valve is held stationary by means of the pedicle. Through
the contraction of two pairs of muscles (aductors or dwwvaricators)
extending from the posterior portion of the pedicle valve to the
cardinal process on the opposite valve the shell opens, since the
cardinal process by its position posterior to the teeth forms a sort

ter Beecher, and Beecher and Schuchert).

of lever with the teeth and sockets’ as fulcrum, and the front of

174 NORTH AMERICAN INDEX FOSSILS.

the brachial valve as weight. The valves close by the contraction
of two muscles (adductors) passing from the brachial to the pedicle
valve. A pair of muscles extending from the brachial valve and an-
other pair from the pedicle valve with insertion on the pedicle,
enable the shell as a whole to move in many different directions.
In the Inarticulata the opening and closing of the valves is effected
by a more complicated set of muscles. (See Lingula, Fig. 221.)
The body of the animal, lying in the pos- ;
terior portion of the shell, occupies only
about one third of the interior. The body
wall gives: off two folds or mantles, one
fitting closely to and building the pedicle
valve, the other building the brachial
valve. Most of the space between the
mantles is filled with the tentacle-bearing
_ Lophophore (Fig. 220, 1); this is supported
by the brachidium. Those portions of
the lophophore which diverge arm-like
from the two sides of the mouth are called
the dvachia. Through this lophophore and _ FIG. 221. Lingula elderi,
tentacles as well as through the mantle outline of tater) a
the animal gets its necessary Oxygen ascular markings; @, di
There is also a cilia-lined groove, which is _ varicator muscular scars ; ad,
bounded on the outside by the line of ten- adjustor muscular scars; pa,
tacles and on the inner side by a wavy Posterior adductor scars; aa,
anterior adductor scars; x2,
ridge, and which extends from the mouth 4,,-% of advance of the mus¢
along each arm of the lophophore. cular scars; s, great pallial
Through :this, microscopic food. particles sinuses; 2s, postenor Cours
(diatoms, infusorians, etc.) are swept into = the latter 2 ae
: Ree cations of the sinuses. (Af-
the mouth by the action of the cilia. The |. Whitfield. )
mouth, a were slit, is in the middie of the
lophophore; it leads into a stomach through an wsophagius. The
stomach leads into an zzfestine, which often ends as a blind sac.
The body cavity or coelome extends into the lophophore and also
sends off four canals( pallial sinuses) into each mantle; the outer
ones are much branched. Impressions of these pallial sinuses are
often found on the inside of the shell and on internal molds (Fig.
2a sy.
ae function of the blood is performed mainly by the fluid fill-
ing the coelome and moved by the cilia lining it. A contractile
heart and some vessels leading from it have been observed.

valve showing muscular and

!
|

BRACHIOPODA. 178

The nervous system consists of a ring around the cesophagus
with two swellings or ganglia in it; nerves are given off to the
rest of the body.

It is apparent that the pedicle valve is so called because the
pedicle passes out through it and the brachial valve is so named
because the arms or brachia are fastened to it.

Brachiopods are, in the larval stage, free-floating or mero-
planktonic, and hence it is during this aceite of their lives that
their distribution takes place.

Brachiopods appear in the Lower Cambric; they reach their
maximum in the Siluric and Devonic and continue to the present.
There are about 6,000 fossil species known and 140 recent.

These shells often appear very similar to Pelecypods but may be
distinguished from them by the following characters, which as a
rule hold true:

BRACHIOPODS. PELECYPODs.
Equilateral. Inequilateral.
Inequivalved. Equivalved (generally).
Pedicle opening present coe in No pedicle opening present.
Atremata).
Teeth in one valve, sockets in the Teeth and sockets in each - valve
opposite valve (except Jvartic- . (typically).
ulata)..
No ligament present ; valves opened Valves opened by ligament or resilium
by muscles. at hinge line.

Brachiopods are divided according to the presence or absence
of teeth into two subclasses :

I. Jnarteculata — Teeth absent. Valves held in apposition by
muscles. This is subdivided into two orders:

1. Atremata — Pedicle emerging from between the valves and
usually with no pedicle opening present.

2. Neotremata — Pedicle opening confined to pedicle valve and
modified by false deltidium or by listrium.

Il. Articulata — Valves articulated by teeth and sockets. This
is subdivided into two orders:

1. Protremata — Pedicle opening restricted to dedi valve and
modified by true deltidium. Brachia have no calcareous supports
except very short ones in Pentamerus.

2. Telotremata — Pedicle opening shared by both valves in
early life and usually confined to one in later stages. Brachia
supported by calcareous supports. Deltidial plates usually present.

176 NORTH AMERICAN INDEX FOSSILS.

LITERATURE.
I. Btbliography and Synonymy.

1897. Schuchert, Chas. Bull. U. S. Geol. Surv. 87. See also
Miller, S. A., under general references.

Il. Descriptive Literature. — Selected Works.
1847-67. Hall, James. Pal. of New York, vols. 1-4.

1892-94. Hall, James, and Clarke, J. M. Pal. N.Y. vol.8. Pt. 1,
II. A discussion of the genera.

1892-94. Hall, James, and Clarke, John M. An introduction to the
study of the Brachiopods; intended as a Handbook for the use of stu-
dents. rrth Ann. Rep. N. Y. State Geol., p. 132 and 13th report, pt. II.

These series contain a most complete discussion of Paleozoic genera
and species.

1852. Owen, D. Geol. Rep. Wis., Ia. and Minn.
1858. Hall, J. Geol. Surv. Ia., 1, pt. 2.

1862-74. Billings, E. Palzeozoic Fossils, 1, 2.
1866-73. Meek and Worthen. Geol. Surv. Iil., 2-5.
1872. Meek, F. B. Final Rep. U. S. Geol. Surv. Neb.
1873-75. Meek, Hall, Whitfield. Pal. Ohio, 1, 2.

1875. Whire,C. A. U.S. Geol. and Geogr. Surv. west of rooth
Meridian, 4.

1877. Meek, F. B. King’s U.S. Geol. Expl. goth Parallel, 4.

1881-84. Hall and White. Rep. State Geol. Ind., ro, 11, 12, 13.

1884. Walcott, C.D. Mon. U.S. Geol. Surv. 8 (Eureka, Nevada).

1885. Whitfield, R. P. Mon. U. S. Geol. Surv. 9 (New Jersey
Cretacic and Tertiary).

1886. Walcott, C.D. Bull. U.S. Geol. Surv. 10, 30 (Cambric).

1889. Nettelroth, Henry. Kentucky Fossil Shells. Kentucky Geol.
Surv. Monographs.

1893. Winchell and Schuchert. Minn. Geol. Surv., pt. 3, 1

1894. Keyes, C. R. Mo. Geol. Surv., 4, 5.

1897 to date. Walcott, C. D. Proc. U. S. Nat. Mus., 19, 21, 25.

1900. Beede, J. W. Univ. Geol. Surv. Kan., 6 pt. 2 (Carbonic of
Kansas).

1903. Weller, S. Geol. Surv. of N. J., Pal. 3 (Paleozoic of Ni J}

1903. Girty, G.H. Prof. paper, U.S. Geol. Surv., 16 (Carbonic of
Colorado).

1907? Walcott, C. D. Geuden Brachiopoda. Mon. LI. U. S.
Geol. Survey. In preparation.

5s ee Le nce: See a

1

Pie)

BRACHIOPODA. 177

ARTIFICIAL KEY TO THE GENERA.

ERM NOU MALIA 55 55.5.05 55 sa bon d0 Saws win erie cone ULNA eealus an ave eae aah stately thames ‘i
I. Shell cemented, calcareous, with no pedicle opening or notch (rarely free).. I.

1. Interior of each valve with a large, elevated muscular impression.
XXV. Pholidops.

I. Interior of each valve with three or four muscular impressions............ a
a. An S-shaped vascular sinus present............ 2... XXIV. Crantella.
a. No S-shaped vascular sinus present .............sseee08 XXIII. Crania.

I. Shell attached by pedicle, phosphatic ; pedicle opening or notch present..... 2.
2. Pedicle opening a narrow groove, not extending to the margin of the shell. 4.
6. Pedicle groove very narrow, extending almost to the margin of the
SRE eoe re acialies Aw ag ead teas Contented hae ete se XIX. Orbiculoidea.
6. Pedicle groove suboval, extending about half way from the beak to
‘ EE Marsan OF Ce WAVE. 65.5 is dis ote seca vas Banc caceeaao vanaeeeipns LF;
Ir. Both valves convex, the pedicle the more so,. XXI. Schizotreta.
11. Brachial valve very convex ; pedicle valve concave..,......... aa.
aa. Pedicle opening surrounded by a depressed area.

XX. Discinisca.

aa. Pedicle opening not surrounded by a depressed area.
XXII. Remerella.

2. Pedicle opening round, abruptly truncating the apex .............ceeeeseeees Ee
c. Shell depressed-convex ; beak elevated...............0. XII. Acrothele.

eee OL ECU COTCRL fede aia. Ssia vp x tas win pe Modena bande decd avbues Saaqusened onder 22.

22. Pedicle valve with an apparent cardinal area .............0+ + bo.

66. Two wart-like protuberances on the umbo.. XI. Acrotreta.
66. No wart-like protuberances on the umbo... XIV. /phidea.

22. Pedicle valve without apparent cardinal area.
XIII. Linnarssonia.

aedicle opening. a triangular Hoth. 2.2 id5.05 caccseconses sedeaeessasceseuee nesses a.
d. Surface with prominent radiating pits... .............000. XV. Trematis.

Pe MMMACE WiKNOULPACiatinig: PIIS).4.0-cidiienes cies vaqheeencsas ves cov sneseeste 33.

33. Brachial valve extending beyond the pedicle valve on all sides. cc.

cc. Surface with radiating strize ............ XVI. Schizocrania.

cc. Surface without radiating striz..... XVII. Lingulodiscina.

33- Brachial valve not extending beyond the pedicle valve.
XVIII. Schizobolus.

a a i a i i i ei i i ie i i a i i el a ed, oe ee eel ee eee ees ee

esis cisions fy 38s casus eave tad seated an eh beavokiy peasaesdoesenade a7,
II. Cardinal area absent or if present rarely straight and generally confined to
pedicle valve ; hinged line curved or if straight very short ................... 3

3. Shell obolelloid — Small, thick-shelled, ovate in outline. Cardinal areas

eM MMRSEAe rag siats ae pe em ar eens ae tarot ae oon Sow dome anid baa eseaadavs wag ea deeus ee

BRSMeM CALCATEO<COMMEOUS,, . 54.2.005.segacs conse seetasves ces uee Il. Dicellomus.

PE MINTCUNERECIMML, Doro t, So sagnuntnobevudaqess'dec notes aahyous dame ¥epewiacwaoc’ 44.

44. Umbo very conspicuouS..............-.cseeeees XXVI. Kutorgina

BA MO MD HOE CONSPICUOUS, 2005 ci cceweaeaneds es sacdlewansievots I, Obolella.

3- Shell trimerelloid — Large, thick-shelled. Cardinal area of pedicle valve
very high ; beak straight and very prominent. Beak of brachial valve
inconspicuous. Interior of each valve has a conspicuous platform ex-
tending: from: the Desks: forward 15 i25.iias} cassia sivas sSd sane dads Gecnasacds Si

:
j

178 NORTH AMERICAN INDEX FOSSILS.

f. Platforms very prominent with conical cavities beneath
55. Conical cavities very long, extending from one third to one half
the length of the shell as shown by the internal molds.

V. Trimerella.
55. Conical cavities short, extending about one tenth the length of

EES el SPOS IN alo a ee ne RN III. Dinobolus.
jf. Platforms not very prominent, solid (2. ¢., with no cavities beneath
2) ee Se See ee SS eee ee IV. Monomorella.

3. Shell linguloid — Elongate, corneous, thin (except Limgulasma)........

g. Inequivalved (pedicle valve the larger, projecting posteriorly), <a
late 66.

SOF eee HEHEHE HEE EES SEH EHHE HEHEHE EEE EEE EEE HEH ETH ESE EEE SEES EE HEE EEE HEES EE EES

66 Cardinal area distinet:;.ic.. cs cna dies scsee2 vcedsonscopadaceenee aie dd.
dd. Shell minute (about 4, inch long).* VIII. Leptobolus.
dd. Shell larger ( % to 3 ich long) with high cardinal area.
VI. Lingulella.
66. Cardinal area not distinct ; pedicle valve often much produced

Si genia six; Pash kebas Lwedazsandisteeen meas VIL. Lingulepis.
g.) Eequivalved.. Surface glistening )...0....0tis.sseis se odes desea Th.

77. Platform present in the posterior portion of each valve.

X. Lingulasma.
772 rNo: platform present |.5) Sogo sseceg kh detcean te jux Sweagee - IX. Lingula.

3. Shell pentameroid — Usually longer than wide and expanding in width
from beak to front. Beak generally incurved, not truncated by fora-
men, rarely with area. Sinus and fold variable. A spondylium in

pedicle walveie:. jis tceecstesaesadeeiws say atadenlib douna¢ Suletans seem een A.

h. No radiating striz or plications........... TE EE er 88.
$3. Siaus or fold. presents; . if. oh76 dsenstedndve scan acgnee denen ee.

ee. Small (average length 3 inch)............. LXII. Camarella.

ee. Not so small t:

POCO OHO Se HEHEHE EHS SHE HEH ESHEETS ESHEHEE HEHEHE SESE OHS EE EES

t+ Umbo of pedicle valve very prominent and overarching *.
* Sinus in pedicle valve and fold in brachial.

LXVIII. Clorinda.

* Sinus, when present, in brachial valve and fold in

peeicles 2203 SiS aise. des cee LXX. Gypidula.
t+ Umbo of pedicle valve small....... LXVII. Pentamerus.
$8. Sinus:or fold absent... svc. iscsi. sevebaden ces sqonw ee 0acndeeeeeee
if. Umbo of pedicle valve prominent.......... LXX. Gypidula.
Pe ipso aN sinesarnacncsesindancsanniainse LXVII. Pentamerus.
A, With radiating strize or plications, without area............seseeeeeees 99.
99. Simus.or fold present 255.5 6cc000 eases 5.20 Sed odes see ge
gg. Strize or plications absent from umbo...............02+e+00 TT-
tt Small (average length % inch)..... LXII. Camarella.
TT Late a... cs cninanotesinhexatbanane [pin -nivy keene es
** Umbo of pedicle valve large..... LXX. Gypidula. —
** Umbo comparatively small...............2 sseeee 17h;

1’’ Shell outline subcircular.

LXIII. Parastrophia.
1’’ Shell outline subtriangular.

LXXII. Camarophoria.

* All measurements refer to adults,

i |

BRACHIOPODA. 179

gg. Striz or plications extending from umbo to front of shell. +f.
ttt Pedicle valve the larger with more prominentumbo. ***,
*** Radiating plications very few and broad...... otf,
2’’ Umbo of pedicle valve strongly overarching.
LXVIII. Clorinda.
2’ Umbo not overarching.

_LXVII. Pentamerus.
*** Radiating plications numerousand prominent. 3/7.

3/’ Spondylium only in pedicle valve.
LXXII. Camarophoria.
3/7 Spondylium in pedicle and brachial valve
A erAaNeUWIRM 9. 25 0k OOS oe de el eer enon ewes a’’.
a’’ Umbo of pedicle valve closely incurved

against the brachial.
LXVIII. Clorinda.
a’’ Umbo of pedicle valve projecting above
Pe EMC ME rane cece -vocirt steer ties Beer,
1/’/ Sinus, when present, on brachial
valve and fold on pedicle.

LXX. Gypidula.
1/’’ Sinus on pedicle valve and fold on
brachial... LXIX. Pentamerella.
ttt Brachial valve the larger. Both umbos very closely
incurved, that of the brachial valve the more prom-

RQGHES sped oop Ciakt yctasusap xt LXIV. Anastrophia.

Oo. oitis on-iold- absent... ..3 sel eencsJecexe Ae hd soy ties ee hh.
Ah. Shell: with radiating plications ..0..0... 0.050 s0.0aseeneces TTH:
tttf Plications few and broad...... LXVII. Pentamerus.

Fibs CHUCNS MUMCTOUS, 4... hoc. 5 cane vee seh scee aces sasiene iii

**** Plications angular ...... LXXII. Camarophoria.

SOE ACR IOUS FOUN: <1 co0im0 sociad shy ones seaviyn ads denans 4?

4’’ Spondylium in pedicle valve.
LXV. Conchidium.
4’’ Spondylium in both pedicle and_ brachial
WRIWOS Aaa enkavnn’ waseesuaeest LXX. Gypidula.
hh. Shell with radiating strize, very fine plications or smooth. 5}.
5t Pedicle valve with aspondylium. LXXI. Amphigenia.
5t Pedicle valve without a spondylium.
LXXXVIII. Rensseleria.
A. Shell with small area and with radiating striae or plications....... 000.
‘900. Area on both valves, nearly equivalve. LX VI. Stricklandinia.
ooo. Area on pedicle valve, which is the larger and has overarching
PRTG sie oA EA ah aia once One awh Smee vc aa dinate wu nace Suv naidte a2.
27. Sinus on brachial and fold on pedicle..... LXX. Gypidula.
zz. Sinus on pedicle and fold on brachial valve.
LXIX. Pentamerella.
3. Shell rhynchonelloid — Length and breadth sub-equal. Cardinal areas
rarely present. Umbo not prominent, becoming abruptly pointed
(z. e.. forming a concave line from beak to greatest width of shell). |
_ Beak usually closely incurved, generally not truncated by foramen.

180 NORTH AMERICAN INDEX FOSSILS.

Sinus and fold prominent, in typical forms surface with plice gen-
rea PRES E ceeacen. ean ay \ ccactuscrteeast. Acai aca nud kav encgcke doen px eee ts
G, MRbONe ane SMMIS AIS ORE Bi 2. <0 cass wanes sow nnnacaressen «se cgncde=starsaeeke III.
I1f. Large, with talse area, no spondylium, LXXXV Peregrinella.
111. Small, with spondylium.......... ......... LXXII Camarophoria,
¢. THONG Bind SMES ONOSERE Ef yA.; cite idaceeasecatewehcen tse pwartsaeeen eee 2223
222. Plicationsmoderately developed on the lateral slopes or wanting,
prominent centrally and anteriorly, no spondylium........... Bi
jj. Sinus exceedingly prominent............ LXXXII. Pugnax.
jj. Sinus moderately prominent...... LXXVIII. Letorhynchus.
222. Plications absent from the umbo,sponydium well developed. ££,
kk. Plications roughened by strong concentric growth lines.
LXXII. Camarophoria.
be; Plications smooth... 55s5<0i00%.c.seheysocessne0s toe re ee 6t.
6+ Shell very small (about 4 inch long).
LXII. Camarella.
a 6+ Shell moderately large........... LXIII. Parastrophia.
222. Entire shell covered with plications or striations.............. pie
77, Both umbos very prominent, that of the brachial valve the
more conspicuous, well marked spondylium in pedicle
MEV L E aace Sania Mert auee donanenenmay LXIV. Anastrophia.
1. Umbo of pedicle valve the more prominent................ oe
7+ Pedicle umbo very closely incurved over thebrachial. 5*.
5* Plications marked anteriorly by a faint median line.
Shells ventricose, no spondylium............ 5%
5’’ Median septum and cardinal process in brach-
ial valve well developed.
LXXIX. Uncinulus.
5’’ Cardinal process absent... LXXX Wilsonia.
5’’ Median septum in brachial valve very faint.
LXXXI. Aypothyris.
5* Plications not marked anteriorly by a median line.
6%
6/’ Pedicle valve with obscure muscular scars and
well-marked spondylium.
LXXII. Camarophoria.
6’’ Pedicle valve with prominent muscular scars
without spondylium............. ine ee
b/’ Brachial valve ies seen cpa ial
2///, Septum excavated posteriorly ;
teeth supported by lamellz ; no
cardinal process.
LXXVI. Camarotechia.
2//’, Septum not excavated ; strong
recurved teeth without lamella;
slender cardinal process.
LXXIV. Rhynchotrema.
6/’, Brachial valve without median septum,
“LXXVII. Stenochisma.
7+ Pedicle umbo projecting, not very closely incurved over
the brachial, commonly showing deltidial plates and
FOP AMEN cise dicedioeduis bu-0s vakictwbessedepiedonsoiee eee

TT -— S.-i. 2

lt i te te ne ee

BRACHIOPODA: 181

6* Hinge line straight with flattened margins ......7/7.

7/’ Pedicle valve prolonged posteriorly and

acutely triangular, flattening from large

Geltaritim. 2.35.52 LXXV. Rhynchotreta.

7’’ Pedicle valve not prolonged posteriorly ; flat-
tening a cardinal area in each valve.

LXXIII. Orthorhynchula.

6* Hinge line curved, no flattening................. aff,

8’ Pedicle valve with deeply excavated muscu-

lar scars, sinus forming nasute anterior pro-

longation......... roaeiretes LXXXIII. LZatonia.
8’’ Pedicle valve with muscular scars not deeply
CRCAVBECO co: iiss cenenasoeanalvaveesiis conpeon eft

c/’ Shell structure punctate.
LXXXIV. Rhynchopora.
c’’ Shell structure not punctate.......... 37/7.
3/’’ Pedicle valve with pseudo area and
strong teeth supported by lamel-
le ; brachial valve with septum
entire.

LXXXV. Rhynchonella.
3/// Small teeth with slender lamelle,
septum of brachial valve exca-
vated posteriorly............. ef"2.
a//’ Plications low and rounded.
LXXVIII. Lecorhynchus.
a/’’ Plications sharp and angular.
LXXVI. Camarotechia.
3 Shell terebratuloid or athyroid — Typically no flat cardinal area. Hinge
line curved. Beak incurved, often truncated by foramen. Median
sinus and fold often absent; when present usually broad and ill-de-
fined. Radiating plications or striz usually absent ; when present they
are never angular; arms generally supported by calcareous brachidium. 7.
J. Shell smooth, calcareous brachidium present...............eeeeceeeees 233.
333- Median sinus and usually fold present...............eeceesees mm.
mm. Beak of pedicle valve truncated by a round foramen., 8f.
8+ Length and breadth subequal, brachidium a spiralium.
7.

7* Shell usually small (about 3¢ inch long or less).
CXXIII. Semznula.

7* Shell of medium size, margins of sinus rounded.
CXXIV. Meristella.
7* Shell of medium size, margin of pronounced and
broad sinus angulated, fold with median groove.
CXXV. Pentagonia.
8} Length greater than breadth, brachidium a simple loop.
8*,
8* Beak of pedicle valve prolonged and greatly in-
curved over opposite valve. Pedicle opening
DAR ig Aisi ate ah brads eee eyes XC. Dielasma.

182 NORTH AMERICAN INDEX FOSSILS.

8* Beak of pedicle valve much less prominent... 9/7.
9’’ Shell usually plano-convex (pedicle valve
COMVER on act ana LXXXVII. Centronella.
9’’ Shell biconvex; length but slightly greater ©
than breadth....... niet XC. Cranena.

8+ Length greater than breadth, brachidium a spiral.
CXV. Whitfeldella.
mm. Beak of pedicle valve not truncated by a round foramen;
brachidium a spiralium or complex loop...............:. oT.
ot Median sinus a mere groove...... CXVII. Avxcleospira.
gt Median sinus very broad and ill-defined; no fold

resent CXX.* Meristina.
p See cere cress e ree sessereerees C X X I V : *% Meristelian

gt Median sinus very broad and pronounced, sides angu-
lated, fold pronounced and with median groove.
CXXV. Pentagonia,
9t Median sinus and fold both present and of normal
WUE og ech dene ap adeeuultiaeans ae ee ee 9*.
g* Sinus and fold only upon the anterior portion of the
shell, spire very short...... XCVIII. Cyclospira.
g* Sinus and fold extending from umbo ........... 10//
10’7 A broad plication present on each side of
median sinus and fold... CX VI Ayatella,
10’ No plications present........ CV. Martinia,
333. Median-sinus and fold absent,.:.....:....ccd.cs ches ste mm.
nn. Beak of pedicle valve truncated by a round foramen... I0f.
10f Length and breadth subequal; brachidiuma spire., 10%,
10* Concentric growth lines lamellose............ 16
11// Edges of the lamellze spinose.
5 CXXII. Cletothyzis.
11’’ Edges of the Jamellz not spinose. ©
CXXI. Athyris,
1o* Concentric growth lines few and not lamellose.
CXV. Whitfeldella.
1ot Length greater than breadth or subequal ; brachidium
@ IMO: nd xdtaed itexceitentwitnin manescescule eee 11*
11* Umbo comparatively narrow ; shell elongate, 12/’.
12// Concentric growth lines usually well marked.
LXXXIX. Cryptonella.
12’’ Concentric growth lines usually not prom-
PAB 55550 ania ¥eenccen ium eee XCI. Eunella.
11* Umbo broad; shell elongate., XCII. Zerebratula.
11* Umbo broad; shell subcircular,, XCV. Aingena.
nn. Beak of pedicle valve not truncated by a foramen..... Itt.
I1t Prominent cardinal area present.
380. Reticularia perplexa.
11f No cardinal area present........ CXVII. Nucleospira.
j» Shell radially plicate or striate; brachidium wanting in some forms... 444.

—

* These two genera are separated by the character of the loop.

BRACHIOPODA. 183

444. Median sinus and fold present; brachidium when present, a

spire liam i..544).. ii vcsde ad on ve ih dmar nik starmoulleede (nce memesiead 00.
oo. Beak of pedicle valve truncated by a foramen. Shell
transversely elongate ; spires extraverted ............ I2t:

12} Plications covered with minute spines.
CXIII. Parazyga.
12t Plications without spines........... CXII. Zrematospira.
oo. Beak of pedicle valve not truncated by a foramen...... Ft.
13¢ Shell with faint radiating strize ; spirals extraverted.
CXXIV. Meristella.
13} Shell radially plicate; spirals absent, or when present
Oe CXMAVEMEN ~.0-45.c3.vnre toeneceses EN Nope Bad 12",
12* Plications confined to anterior portion of shell ;
spiralium absent........ ones LXII. Camarella.
12* Plications covering whole shell................. ie
13” Sinus on pedicle valve and fold on brachial ;
spirals pointing into pedicle valve.
CXVIII. Axnoplotheca.
13” Sinus on brachial valve and fold on pedicle;
spirals pointing inward (introverted).
XCVII. Zygospira.

444. Median sinus and fold not present ............... fe estan ena aie Lp:
pp. Beak of pedicle valve truncated by a foramen; deltidial
PISCE PP DIR yee aantocwesacss tevadadsusbeyadediceisadsoesiceus 14f.

14} Shell with faint radiating striz; brachidium a loop,

deltidial plates minute...... XCIII. Zerebratulina.

14¢ Shell with coarse plications ; brachidium a loop, delti-

dial plates moderate............ XCVI. Zerebratella.

14+ Shell radially plicate; brachidium of extraverted
spires, deltidial plates pronounced, commonly co-

np 3 | Sa Poe Bera ie Siar RY mee RRS Mg 13".
13* Plications rather coarse............ CXI. Hustedia.
¥3” Piications fine or striate;.. 0.0 J......6ccsenscceos 14”.

14” Deltidial plates uncoalesced.
CX. Homeospira.
14” Deltidial plates coalesced............s+0000+« a”,
ad”, Surface plicate..... CIX. Rhynchospira.
a, Subiace ‘striate. .5... CXIV. Eumetria.
pp. Beak of pedicle valve not truncated by a round foramen. 15.
15 Brachidium a spire turned into the extremely convex
brachial valve ; plications rounded, low.

XCIX. Atrypa.
BG] PeacChicinin: & loops... 0ccaces cools pesnnensssavexdnenes 14*.

14* Length greater than breadth ; plications fine.
LXXXVIII. Renssellaeria,
14* Subcircular; plications angular, prominent; small
well defined cardinal area and deltidial plates
on pedicle valve ........:.. XCVI. Zerebratella.
II. Cardinal area present, straight. Hinge line straight and long, usually more
than one third the greatest width of shell.............ccscscscccesssrscscsossecsersscze Ge

184 NORTH AMERICAN INDEX FOSSILS.

4. Shell strophomenoid—Length and breadth subequal. Hinge line forming
usually the greatest width of the shell. Shell usually concavo-convex,
never strongly biconvex. Cardinal areas well developed; delthyrium
triangular and usually closed (open in Vitulina, Tropidoleptus, Syntro-
phia, Scenidium). Median sinus and fold usually absent ; when pres-
ent very broad and ill-defined. Surface radially striate, seldom plicate
OPSHIGOEN., 5563: Sesese en ssniiedsais nc ostctin$s Bow $G0% sa. bv Snenbe snes staae een k.

es5 Surtees radsally: Stet ake! I26, eivewnadadccodenstes v3 «aisvcanacems See 555-
555. Margins of hinge line finely grooved transversely............ 99°
gg. Shell normally concavo-convex (brachial valve concave,
pedicle:valye convex )i.s..0<0<0: XXXII. Stropheodonta.

gg. Shell resupinate (brachial valve convex, pedicle valve con-
CONE J td acticin ted Soda wtcon XXXIV. Strophonella,

555- Margins of hinge line not transversely grooved............... 1K.
rr. Cardinal margin of pedicle valve with a simple row of
SETH oc asi ceciisine deliois'bes'veuley abiclown dais sta ave en 167.

16f Shell normally concavo-convex..........0.+<sr«seones 15*.

15* Surface simply striate radially... XLII. Chonetes.

15* Surface with a double oblique series of striz ex-

tending from umbo........ XLIV. Chonopectus.

TOF Shell restipinate oo... caesocsezcs XLIII. Chonostrophia.

vr, Cardinal margins without spineS..............scsesesseeeee ivi
17} Radiating striz alternating in height ............... 16*,

16* Shell normally concavo-convex ............+8. ys -

25// Slrell large ies wc. XXXII. Rafinesquina,

15/7 Shell small ...... XXXVI. Plectambonites..

16* Shell resupinate.,.....:..<. XXXV. Strophomena.

17} Radiating strize subequal in height.................. 17%;

17* Front of shell geniculate (abruptly bent almost at
right angles) ; concentric wrinkles on older
POMONA Sa cc tee yar breres XXXVI... Leplena.

17* Front of shell not geniculate...............-0s 16/7,

16’ Radiating striz prominent, sharp, crowded ;
umbo apt to be distorted...............00. eft,
e’’ Pedicle valve with spondylium.
LIX. Chtambonites.
e/’ Pedicle valve without spondylium... 4/77.
4’’/ Muscular area of pedicle valve sur-
rounded by a strong ridge.
if XLI. Aipparionyx,
4’’/’ Muscular area of pedicle valve not
surrounded by a strong ridge.
b//?,
6/// High median septum present,
running through center of
muscular area.
XXXIX. Orthothetes.
6//’ High median septum not pres-
ent. XXXVIII. Schuchertella.
16// Radiating striz faint.,.....).<7/ceeeeeanee JT"
f// Shell concavo-convex, resupinate.
XXXV.. Strophomena.

BRACHIOPODA. OBE

f’’ Shell plano- or bi-convex.
XXVIII. Lillingsella.

A Surface. radially. plicated. isv..gasitencs sud Menta e eae oe 666.
666. -Plications’ coarse, radially striate...,...,55<252. 00 XL. Meekella.
666. Plications not radially striate .............. PAAR ren i Rep Rat ot PANN SS.

ss, Entire surface pustulose. Shell small..... CXIX. Vitulna.

ss. Spines irregularly distributed on the crests of the plications.
XXIX. Misusia.

sé. No spines or pustules present: | ioeeress dees seo suas:
15} Shell. distinctly pimetate,ao0cyretincanccos chee et eee 18*,

15*) Plications’ sharp: 2..c:3hivis. sk XXX. Protorthis.

18* Plications rounded......... XCIV. TZropidoleptus.

18} Shell not distinctly’ punctate.. 10. /....0.0....sc000000 19*

19* Shell very small, cyrtiniform (cardinal area of

pedicle valve very high)..... LX. Scenidium.

19* Shell comparatively large.
XXVIII. Bilhingsella.

Pucuriace spinose (productoid).).0 S04 (220 kasi .dveseeesutaveelasdebestin 777
777. Pedicle umbo prominent and strongly incurved............... tt

Rep ene PAG ien hse wach ab adeaperoncouie ides: XLVI. Productella.

Oe DiMIELL TRE LoL ssivet raed ces cebere ee XLVII. Productus.

777. Pedicle valve not strongly incurved, often truncate.
. XLV. Strophalosia.
k. Surface smooth except for concentric growth lines..........,....... 888,
888. Margins of hinge area vertically grooved.
XXXII. Pholidostrophia.

688..Marpins of hinge aréa not. grooved.......200./c.ccciee.sendceece uu.
uu. Hinge line short. Umbo usually conspicuous. No spon-
dylium, large delthyrium.............. XXVI. Kutorgina.

wu. Hinge linelong. Umbo inconspicuous; spondylium present.
LXI. Syntrophia.
4. Shell orthoid — Shell usually plano- or bi-convex, never definitely concavo-
convex. Hinge line usually much less than the greatest width of the
shell. Cardinal areas well and almost equally developed in each valve ;
triangular delthyrium usually well developed in each valve and open,
Median sinus when present generally very broad and ill defined. Sur-
face marked with radiating strize or plications CODE LA ie pele er eter: Pe
?,. Surface radially plicate (2. ¢., radiating lines coarse )..............68 999
999. Hinge line short, forming about one third the greatest width
of the shell>. Shell globular.) 2yci.....cac LVIII. LZuteletes.
Go TAINO Aime VOM. Vecchia tn coy sede ts teak onde rg uvasecnetowens UU.

vu. Pedicle valve flat or partly concave; brachial convex.
L. Dinorthis.

i
:
:
i
:
;
.
i

Pe, Ee OUICIE WHINE + GOW 85 0) eo lededate eles Meta aes asian LOT;
Iof. Sirachial-walve Mats js. i. civics. csces Reieean calle RE ie te 20*.

20* Deltidium present in pedicle valve............ aca

17/7 Spee GPO SOTIE, 05516 see eas XXIX. Misusia.

ESP PAM SETE oe ena du dens schetdpacens ve ett,

g/’ Shell punctate... XXVIII. Bilhingsella.
g’’ Shell impunctate..... XXX. Protorthis.

186

NORTH AMERICAN INDEX FOSSILS.

20° Ne geltidinm present... ladesisade cat eme@ance 18/7,

18/’ Shell cyrtiniform with erect cardinal area.
LX, Scentdium.
18/’ Shell not cyrtiniform...... XLVIII. Orthis.
Lot Brachial walve COMyeXiy, ois sass.o0sascueees nese 2%
21* Strong mesial fold on brachial valve and corre-
sponding sinus on pedicle valve, both with
sharp plications ........... LIII. Platystrophia.
21* No mesial fold present. Shallow sinus present or
GDSEMi dae cedasvanteusased sane XLIX. Plectorthis.
7, Surface radially striate (2. ¢., radiating lines fine; except Hedertella
DOW ERIES EVA) a sire Sebiseside dings Peete GC e xd doien neleioal see avalon IIII
II1I. Strongly two-lobed. Very small
1111. Not strongly two-lobed
ww. Hinge line short (about % the greatest width of shell). 207.

20t Valves subequal and gently biconvex.

LVI. Rhipidomella.
2ot Brachial valve very convex. Pedicle valve much less

CORVER: Sais sct a oeneeencehaceae eek LVII. Schizophoria.

ww. Hinge line long, pedicle valve deep, brachial valve flat or
SAMIOW «52 cccs sue.iss soesaive f2Sebaiec eee Haku ae went ean 21t

21} Shell substance punctate.............. LV, Dalmanella.

21f Shell substance impunctate.... .-......cs0ssueraee eee . 226

22* Pedicle valve subpyramidal. Deltidium and
spondylium present........ LIX. Clitambonites.

22* Pedicle valve depressed convex. ;;5...2..-9e08 Ig"

19’ Muscular impression of pedicle valve small,
almost confined between the dental la-
Mel ar shies ove cee .. LIL. Orthostrophia.
19/’ Muscular impression of pedicle valve mod- —
erately large, extending about one half

the distance from beak to front.
LI. Hebertella.
4. Shell spiriferoid — Usually transversely elongate with hinge line forming
greatest width of shell. Bi-convex, very seldom plano-convex.
Cardinal area with the open triangular delthyrium most conspicuous
on the pedicle valve, rarely with pseudodeltidium. Median sinus on
pedicle valve and fold on brachial (reversed in A/e¢aplasia, Vitulina,
Scenidium). Shell usually radially plicate, rarely smooth or striate.
Brachidium typically an extraverted spire.........c00«s.ssssseeeeepenee m.

m. Conspicuous spines present.

CIV. Reticularia (except R. nevadaensis, R. levis and R. perplexa).
ae; Wimite spines’ pr@Bent);. 0.00 kc sacservaeace 324. Spiriferina spinosa.
m.. Spines absent, or MICTOSCOPIC . 256.0. 022. os cee one's seen eds 2222.

2222,.. Sutface lacking plications.../.......<.2:<.cs00+ecnnes scene Bon

ax. Mesial fold and sinus normal in position (2. ¢., fold on
brachial valve and sinus on pedicle).............+ 227,

22} Surface smooth.
CVII. Ambocelia (except A. planoconvexa)
22} Surface with concentric strie. ............s00.0eee 23%)

———— =

BRACHIOPODA. 187

23* Sinus and fold undefined and shallow.
376. Reticularia levis.
23* Sinus and fold defined and angular.
; CV. Martinia.
22{ Surface radially striate........... 326. Spirifer radiatus,
22} Surface minutely granular (seen under lens).
388. Ambocela planoconvexa.
xx. Mesial fold and sinus reversed in position.
CVIII. Aletaplasia,
xx. Mesial fold and sinus lacking or faint.................... 23%.
23 Beak of pedicle valve high and incurved; that of
brachial not incurved. Shell nearly plano-convex.
XXVI. Kutorgina.
23{ Both beaks incurved. Shell bi-convex.
380. Reticularia perplexa.

S222. curlace splcCateds:.sasjiicstscast stevia wh oboSae tpwnss cebysenaees’ BAe
wy. Hel Aprachive® Miele, Malus .sbi sms -Sesasasis Goa vewnen dens 24.
PAP MMM gutewiies teva tteotuaes ber aN es war ae eee SaRSEN ON 24%,

2a* Cardinal area presents ...2: .csiss See saecognee es. 207,

20/’ Cardinal area very high, giving the shell a

semipyramidal form............ C. Cyrtina.

20’’ Width much exceeding length, the shell thus
lacking a semipyramidal aspect.
CII. Spiriferina.
24* Cardinal area absent. Umbo of pedicle valve
truncated by a round foramen.
CXII. Zrematospira.
24} Large, spiriferoid, with pedicle tube or syrinx in rostral
cavity of pedicle valve.......... CVI. Syringothyris.
yy. Shel structure not punetate ais... os... catesaaservorsees oo 25f.
25} Low fold on pedicle valve and sinus on brachial. 25*.
25*, Shell pustulose, brachidium a spire.
CXIX. Vitulina.
25* Shell not pustulose, brachidium absent.
LX. Scenidium.
25} Well marked sinus on pedicle valve and fold on brachial.
26*.
26* Cardinal areas of the two valves subequal in
height; plications angular, including fold and
sinus; no brachidium..... LIII. Platystrophia.
26* Cardinal area of pedicle valve greatly exceeding
that of the brachial ; brachidium spiral... 21/7.
21’’ Cardinal area very high, form of shell sub-
pyramidal, deltidium perforated.
CI. Cyrtia.
21’ Cardinal area variable, form not subpyra-
midal, deltidium absent or without perfora-
RGD pd cet gehts Sons te aep ven LA OEE er:

188 NORTH AMERICAN INDEX FOSSILS. 4

ATREMATA.

I. Oxsovetra Billings. :

Small, thick-valved, oval or round shells. Narrow cardinal area
on each valve; that on the pedicle valve is crossed by a pedicle |
groove, not a slit. A long narrow muscular impression is present —
on each side in the interior of both valves. Shell structure cal- —
careous. Cambric—?Ordovicic. |

1. QO. atlantica Walcott. (Fig. 222, a—d.) Lower Cambric.
-Resembles O. crassa but differs in its average smaller size (4-4 _

inch long), in its more circular form due to the lesser prominence ©

of the umbo and in its stronger concentric growth lines.
Etcheminian of Massachusetts, Newfoundland.

s

Fic. 222. a-d, Obolella atlantica; a, exterior of ventral valve; 4, mold of —
interior of same; c, exterior of dorsal valve; @, mold of interior of same (greatly en- ‘9
larged) ; e-g, Obolella crassa; e, ventral valve, & 2; f, mold of interior of same; gy
mold of interior of dorsal valve (a, cardinal ; ¢, central, and @, lateral or internal mus-
cular scars; f, pedicle groove ; x, area) ; 2, Obolella gemma, interior of a dorsal valve, —
much enlarged. (All after Walcott.)

2. O. crassa (Hall). (Fig. 222, e-g.) Lower Cambric.

Sub-orbicular with beaks extending slightly beyond the margin. —
The two valves are almost indistinguishable from each other; the
beaks of both are curved down, that of the brachial valve nearly —
touching the short, indistinct’ hinge line. Surface of both valves ©
radially and concentrically striated. Shell thick and solid. Average
shell is % inch in length.

BRACHIOPODA—ATREMATA. 189

Etcheminian of Massachusetts, and Georgian of New York,
Quebec.

3. O. gemma Billings. (Fig. 222, 4, 223, 4,0.) Lower Cambric.

Ovate. Pedicle valve with an acute beak. Brachial valve nearly
circular and obscurely triangular at beak. Surface of both valves
usually nearly smooth or feebly striate. Average length } inch.

Georgian of New York, Quebec.

4. O. nitida Ford. (Fig. 223, c.) Lower Cambric.
Brachial valve gently convex. Hinge line slightly curved and
equalling about one third the width of the shell. Surface marked
by a well defined median depression ex-
tending from the most elevated portion of
the valve forward for about one half the
length of the shell. Valve covered with
j very fine radiating and concentric strie.
Diameter about ¥% inch.
Georgian of New York, and Etchemi-
nian of New Brunswick.

II. DiceELtLomus Hall.

Small, thick-valved, ovate, biconvex
with apices marginal. Outer surface of
shell finely punctate. Shell substance cal-
careo-corneous. Differs from Odolel/a in
the partially corneous character of the Bea a hohe
: shell substance, in the absence of a fora- gemma, ventral valve, d< 6;
minal opening and in some internal char- 4, dorsal valve, & 63 ¢,
acters. In Dicellomus the interior of the 2 ”###da, dorsal valve, 5.
pedicle valve shows a short cardinal area ee)

with a median pedicle groove, composite muscle scars and a short
Shelf, like a spondylium extending into the valve from each side
of the pedicle groove. The interior of the brachial valve has a.
marrow cardinal area in one species, D. politus, Middle-Upper
Cambric.

5. D. politus Hall. (Fig. 224.) Middle-UpperCambric.

_ Valves moderately convex with greatest width near the front
which is broadly rounded. Pedicle valve acuminate. Umbos

190 NORTH AMERICAN INDEX FOSSILS.

prominent. Cardinal areas in both valves. Surface smooth
except for concentric lamelle.

Upper Cambric of Wisconsin, Minnesota, South Dakota, Middle
Cambric of Montana, Arizona, Oklahoma.

Fig. 224. Dicellomus politus exterior natural size, and interior of ventral and dor-
sel valves much enlarged. (After Hall.)

III. Drinosotus Hall.

Subcircular ; valves convex and thick. Pedicle valve with an
acute, prolonged beak; cardinal area triangular, deltidium present.
Brachial valve with inconspicuous beak. A V-shaped platform,
with the apex of the V anterior, extends in each valve from the
beak half way to the front; the vaults beneath are more conical
than in Zrimerella. Ordovicic—Siluric.

6. D. conradi Hall. (Fig. 225, a.) Siluric.
Oval, slightly wider than long and very symmetrical in outline.
About 1% inches wide by 13 inches long.
Niagaran of Ohio, Iowa, Illinois, Wisconsin.

IV. Monomere.ra Billings.

Gibbous. Umbo of pedicle valve more or less elevated with
high cardinal area; umbo of brachial valve inconspicuous, In-
ternal platforms of both valves much less prominent than in Trim-
erella and Dinobolus and with no empty space beneath; platform
of pedicle valve usually continued forward as a strong septum.
Siluric.

7. M. prisca Billings. (Fig. 225, d-c.) Siluric.

Pedicle valve ovate with greatest width at about the anterior
third of shell; beak narrowly rounded, front broadly rounded;
septum for about one third the length of shell. Brachial valve
about one fourth shorter than the pedicle and more convex, with a

’
_

Le ee ee ee ae eS eT

BRACHIOPODA—ATREMATA. IQI

more broadly rounded anterior portion. Pedicle valve one and a
half inches long by a little over an inch wide.
Guelph of Ohio, Illinois, Ontario.

Dinobolus

Monomerella

Fig. 225. «@, Dinobolus conradi, interior of pedicle valve, % (a, deltidium ; 4,
deltidial slope; ¢, deltidial ridges ; d, areal borders ; 7, side of crescent muscular area) 4,
Monomerella prisca, internal mold of brachial valve ; ¢c, internal mold of pedicle valve,
x %. (z,umbonal chambers; 4, platform-vaults ; 7, median scars ; 2, anterior scars;
o, lateral scars ; 7, side of crescent.) (After Hall and Clarke.)

V. TRIMERELLA Billings.

Thick, elongate-ovate. Cardinal area of pedicle valve very
prominent ; pedicle opening closed by a broad deltidium which is
concave owing to the bounding ridges. Brachial valve with no
cardinal area but incurved against the deltidium. Long and
narrow platforms are present in both valves extending from the
apex over half way to the anterior margin; that of the brachial
valve is the higher. The area beneath the platforms is occupied
by two long, tubular cavities. Most American specimens are
internal molds in dolomitic limestone. | Siluric.

8. T. acuminata Billings. Siluric.

Pedicle valve ovate, widest a little in advance of the middle,
tapering from there with nearly straight sides to the beak which
is almost acute; the platform bears a deep median furrow.
Brachial valve much shorter than the pedicle, more convex and
with beak more strongly incurved. Surface marked by coarse
concentric growth lines. A very large specimen measures 3%
inches in length by 3 inches in width.

Guelph of Ohio, Illinois, Ontario.

g. T. ohioensis Meek. (Fig. 226, a, 0.) Siluric. .

Differs from 7: acuminata in its broader form, and less produced
and blunter beak, with thicker septa as indicated by the mold.
In the Niagaran beds of Ohio, Illinois and Ontario.

192 NORTH AMERICAN INDEX FOSSILS.

10. T. grandis Billings. (Fig. 226, c d@.) | Siluric.

Ovate, with the greatest width a little in advance of the middle.
Both valves moderately and uniformly convex. Surface marked
with obscure concentric growth lines. Length of a large shell is
3 inches; width, 2% inches. This species differs from 7: acumt-

Trimerella

Fig. 226. a, Zrimerella ohioensis, pedicle valve with distorted umbo, K %; 6.
brachial valve, « 2%; ¢, Zrimerella grandis, internal mold viewed from brachial
side, X 24; d, the reverse of the same specimen, 24. (a, deltidium; c, deltidial
ridges ; d, areal borders ; 7, umbonal chambers ; 7, platform ; 2, platform vaults ; 7, me-
dian scars ; g, crown of crescent; 7, side of crescent.) (After Hall and Clarke.)

mata in that the tubular cavities of the interior do not extend to the
beak, the pedicle valve is broader and the concentric lines are

obscure. .
Guelph of Ohio, Wisconsin, Ontario.

VI. LINGULELLA Salter. he

Valves Lingula-like but pedicle valve pointed, with a cardinal

area, and elevated beyond the brachial valve; a distinct pedicle
groove present. Cambric-Ordovicic.

BRACHIOPODA—ATREMATA. 193

11. L. aurora Hall. Upper Cambric.
Broadly ovate; breadth about ¥% inch, length somewhat greater.

Pedicle valve with beak slightly attenuate, cardinal area high.

Brachial valve with very obtuse beak. Surface marked by concen-

tric strize crossed in partially exfoliated specimens by radiating striz.
St. Croix of Wisconsin, Minnesota.

_ 12. L. (Westonia) ella (Hall and Whitf.) (Fig. 229. a, 4.

i | Lower-Middle Cambric.

Brachial valve subcircular or ovate; pedicle valve longer than

| wide, cardinal slopes about 65 degrees (greater when compressed) ;

area flattened, rather broad and with narrow median groove.

Growth lines lamellose towards the front ; radiating lines indistinct.
Wasatch and Oquirrh. Mountains, Utah; near Pioche, Nevada.

VII. Lincutepis Hall.

- Lingula-like but strongly inequivalved. Pedicle valve generally
much produced at the beak. Differs from Lzngu/el/a in the absence
of a distinct cardinal area and
in the often much attenuated
beak of the pedicle valve. Up-

_ per Cambric-Ordovicic.

*

13. L. pinniformis (Owen).
fee (Pig. 227.) Upper Cambric.
Pedicle valve spatulate; pos-
terior portion attenuate, acute, = gee ev tok
: : ~ ; Fic. 227. Lingulepis pinniformis in-
convex in the middle. Anterior ternal molds of ‘pedicle and brachial valves,
“portion semicircular. Brachial y2. (After Hall. )
_ valve without the attenuate por-
tion. Surface of both valves marked with concentric striz and
_ where exfoliated, with faint radiating ones.
_ St. Croix of Wisconsin, South Dakota. Potsdam of New York
and Canada (L. acuminata).

14. L. prima (Hall.) 3 Upper Cambric.
Valves moderately convex with rounded front. Umbo very low.
Surface marked by a few concentric wrinkles and by many fine
longitudinal lines. An average shell measutes ¥ inch by 4 inch
_in length and breadth respectively.

Potsdam of New York, South Dakota.

194 NORTH AMERICAN INDEX FOSSILS.

VIII. Leprosouus Hall.

Minute, with convex valves. Pedicle valve with cardinal area cut
by a pedicle groove. Brachial valve slightly thickened on cardinal
margin. Interior of both valves with two or three diverging septa.
Ordovicic.

15. L. insignis Hall. Ordovicic.

Orbicular with a scarcely pointed beak. Valves regularly con-
vex when not compressed. Specimens usually found flattened.
Surface marked by concentric growth lines. Differs from L. occt-
dentalis in being more nearly circular, with a shorter beak and more
regularly convex valves.

Utica of New York, Ohio, Ontario.

16. L. occidentalis Hall. ' Ordovicic.
Widest below the middle. Valves moderately convex and most
prominent near the beak. Surface marked by concentric growth
lines. About 3, inch in length.
Maquoketa of Iowa and Wisconsin; Lorraine of Ontario.

IX. Lincura Bruguiére.

Shell thin, glistening, generally smooth or with fine concentric
or rarely radiating striz ; generally equivalved; broad anteriorly,
parallel sided or tapering posteriorly. Ordovicic—Recent.

A. Rectangular (sides straight and nearly parallel); hinge extremities abruptly rounded ~

OP GRUNER ECTS any cadens vax aves bolasioe ac dey'akbuins vcveus Snsie Uus'sdoeae anellve oss qt es nthe i
T, (Sutface nearly smooth and: Glossy: 5.5%. ¢ccckc. oases casnnaseastesnepeees 22. L. eldert.
L. ‘Surface'marked by concentric strize:.....,. <0... ccreeccnesce scenes otken eee een LF

5. (Strise Strong; sharp,. Slaell large... 5. cadsccencessone selene eee Pore a.

a.’ Radiatanp vetrice- absent o.55 1.0.2 scaes aceon spavearegne not 24. L. towaensis.

@, Radiating -sivias present. .c\~:vasss0scaacenaneeteck 20. L. rectilateralts,

Hoy SSt1Se AUN, cw atc wns da wsulamisinids w gle vk sie eRe a pen mares ap tine Se aw alee b.

6. Strize crossed by radiating fies aa Win. ines adi Carew oetemmines 26. L. clintont.

db. «strive not ‘crossed by radiating lines \. <..00c.0s ese s0sdes 29. L. cuyahoga.

B; Oval orvelliptical (sides. curving’). so... \se aeaee ser ane few dee count ctst eke eee 1
II. Small, not exceeding one-half inch in length.............. eo 2.
2. Length exceeding: breadth cc. 55 .. overs rdstogdvveacss reo. €.

F<. SPORE SUDETEMICALE. 5 cite tous nie, amnaPenine gm adpeehoac eat! 32. L. subspatulata.

¢. Front broadly rounded ............ccssceesrersocseevsos+sdoceesese hanna T:

of beaks: aitemigte is... swiss naass coe tae neon neieeneee 23. L. modesta,

F OARS DUNES Sid wn tiam onesie snes vienbetiae oa actes «pan eeenae 27. L. isa

c. Front régularly rounded ..... .5...scvecsass eanvas vvnnccnseeeeee eaten Ts

ft With flattening and faint radiating striz ............ 30. L. melie.

Tf Convex, without flattening or radiating striz.. 31. L. umbonata.

2. Length-and breadth. nearly equal... 5. .ivucexssevesvuene vee Maan 18. L. curta.

PY SLMtge EMCI IONS cae setciee' uscianst ov ast ae sunaletaeewecatves woah 17. L. cobourgensts.

BRACHIOPODA—ATREMATA. 195

mumenedce-shaped, with very-acute. beaks: ...2,':,.vialuwssdaaccbecacswunvekssleesempipuaeeens ELT.
Mie N BIVES CONWEX Ni icihincéicwoidugdvs bumepennnaese ee Mimoe's ts Caen eee a oe eae Be

ee EAT OE: o5 cc « ce sacnted ot acta Sisal n Peete eee sae 25. L. cuneata,

Se MU LIUILG sc setae Gas setae « 2 oe enia sao ae kectenle edsanlone ae 28. L. spatulata.

Me ALVES! CEpr essed Jeo cd sucs o.cacynaet ceoeneeon eens auaseats 19. L. trentonensis.
Senate conversing. but. ‘straight sides. 0.6.55. Sicsdtcey d,s ia deckvagcasevewnsdbeyeetetecanae IM.
Reema Ob ise, Large ot ese seces ocning Uv hadencaber jn Game onerea arene 21) L3 eba:
17. L. cobourgensis Billings (Fig. 228, a—d.) Ordovicic.

Large, oval. Both valves moderately convex. Length about one
fourth greater than width. Concentric growth lines fine, becoming

i] a \

fic. 228. a-b, Lingula cobourgensis,; c, L. rectilateralis. All natural size. (After
Billings Can. Geol. )

sharp. Elevated and closely crowded striz on the lateral slopes.
Trenton of Minnesota, southeastern Canada.

18. L. curta Conrad. Ordovicic.
Small, obtusely ovate, depressed convex. Length and breadth
nearly equal. Beaks scarcely projecting beyond the margin of
the shell. Front broadly rounded. Surface covered by elevated
concentric lines.
Trenton-Utica of New York, Pennsylvania, Quebec, Frobischer
Bay. |
19. L. (Glossina) trentonensis Conrad. Ordovicic.
O1 moderate size, ovate-acute, attenuate toward the apex; sides
nearly straight, front rounded. Surface depressed. Smooth or
marked by concentric lines which are crossed by obscure radiating
striz.
Trenton and Utica of New York, Wisconsin, Ontario.

20. L. rectilateralis Emmons. (Fig. 228, c.) Ordovicic.
Large, with nearly parallel sides, form elliptical; front regularly
rounded; surface marked by radiating striz. This species is
readily recognized by its large size.
Trenton—Lorraine of New York, Ottawa and Anticosti.

196 NORTH AMERICAN INDEX FOSSILS.

Y Die

)

Fic. 229. a, Westonia ella, X 2; 6, mold of interior of dorsal valve, & 2; c, Lin-
gula eldert, dorsal view, X 1; ad, L, ligea, X 2; ¢, L. modesta, XK 4; fg h, L. towaen-
sis; dorsal and profile views, and mold of interior of ventral valve, x1; 7/7, L. eva,
dorsal and profile views, X 1; 2, L. umbonata, <1. (After Walcott (a, 6), Win-
chell and Schuchert, and Ind. Surv. (2).)

21. L. eva Billings. (Fig. 229, 7.) Ordovicic.
Widest near the front, with nearly straight gradually converg-
ing sides; valves convex, flattened near front; surface with a few
prominent radiating strize on anterior half.
Black River of Canada, Minnesota, etc.

22. L. elderi Whitfield. (Figs. 221, 229, c.) Ordovicic.
Subquadrangular with nearly parallel margins and subequal ex-
tremities, the beak being somewhat angular and the front broadly
rounded. Valves quite convex. ‘The dorsal or shorter and more
convex valve marked by a flattening along the middle. Surface
nearly smooth.
Trenton and Lorraine of Ohio, Wisconsin, Minnesota.

23. L. modesta E. O. Ulrich (Fig. 229, ¢.) Ordovicic.
Minute, subovate; widest anteriorly. Valves nearly flat. An-
terior third uniformly rounded. Surface marked with very faint
concentric undulations.
Trenton-Lorraine of Iowa, Kentucky, Minnesota.

24. L. iowaensis Owen. (Fig. 2209, /, g, 2%.) Ordovicic.
Large, broadly subquadrate, generally a little narrower above
the middle than below. Beak obscurely angular, front rounded.
Sides gently rounded. Valves convex. Beak of pedicle valve
projecting a little beyond that of the brachial and more pointed.
Surface marked by strong and irregular growth lines.
Galena of Iowa, Illinois, Wisconsin, Minnesota, Manitoba. a

|
|
|

4 x

_ 29. L. cuyahoga Hall. (Fig. 232, 2)

BRACHIOPODA—ATREMATA. 197

25. L. cuneata Conrad. (Fig. 230.) . Siluric.

Wedge-shaped, very acute at beaks. Margins nearly straight,
converging uniformly from beak to front which is but slightly
curved (almost truncate). Valves con-
vex on the posterior half but flattened
anteriorly. Surface longitudinally stri-
ated.

Medina of New York.

26. L. clintoni Vanuxem. Siluric.
Sides of shell straight and nearly par-
allel; abruptly rounded at beak, abruptly

truncate at front. Shell flat anteriorly FIG. 230. Limgula cuneata

enlarged, X2. (After Hall &

but elevated into a ridge at beak and Clarke. )

Maence here very convex. Surface
_ marked by concentric growth lines and radiating striz. _

Clinton of New York, Pennsylvania, Ontario, Nova Scotia.

27..L. ligea Hall (Fig. 229, d.) Devonic.
Narrow elliptical with length twice the

width. Sides slightly curving. Extremities

subequal, with obtuse beak and_ broadly

rounded front. Surface marked by fine con-

centric striz.

Hamilton-Portage of New York, Ohio, Nevada, Ontario.

Fic. 231. Lingula
spatulata, 2.

28. L. spatulata Vanuxem. (Fig. 2 31.) Devonic.

Minute, spatulate, moderately convex; attenuate toward the

; beak ; widest across the middle. Length (scarcely three tenths of
an inch) about twice the width. Surface
marked by fine concentric striz.

Genesee and Portage of New York, Ohio,
Canada and elsewhere.

Devonic—Lower Carbonic. Fc, es aS Lingula
Length and breadth about as five to #ahoga, <1; (after Hall)
three. Sides nearly parallel, converging % 7”s“/@ eH large spect-
: ; : men, X 2; (Meek. -—Ohio
slightly toward the cardinal margins. Beak Pal. )
obtuse; front subtruncate. Surface covered
by fine concentric striz.

Chemung—Waverly of New York, Ohio.

198 NORTH AMERICAN TNDEX -FOSSILS.

30, L.melie Fall. (Fig, 232,'4.) Lower Carbonic.

Generally smaller than preceding, with curving sides and acute
beak, below which is a narrow flattened space gradually widening
to base. Growth lines crowded at intervals; radiating striz

obscure.
Waverly of Ohio.

31. L. umbonata Cox. (Fig. 229, £.) Upper Carbonic.
Of medium size, thin, elliptical with regularly rounding margins
and prominent umbonal portion. Surface smooth except for lines
of growth.
Coal Measures of Kentucky, Ohio, Iowa, and Missouri.

32. L. subspatulata Hall and Meek. Upper Cretacic.
Of moderate size, oblong. Lateral margins only slightly curved,
narrowing the shell toward the front. Anterior margin subtrun-
cate. Surface marked by fine concentric striz.
Nebraska, New Mexico, Manitoba.

xX. LINnGuLasmMa’ FO: Ulich:

Large, thick-shelled Lingule. Brachial valve much the deeper.
Muscles of both valves situated upon a platform which extends
over one-half the length of the shell; that of the pedicle valve is
low; that of the brachial is high and is continued anteriorly as a
strong septum. No pedicle opening present. Deltidium present
and probably entirely internal, thus forming a sheath resting upon
the posterior portion of the pedicle platform. Ordovicic.

Pre ae
--— °.

-

ca

s
Fic. 233. Lingulasma galenaense; interior view of ventral and dorsal valves, and
profile of inner mold with outline of shell dotted in (cv, crescent; g, umbonal scar; 4,
central scars; 7, anterior scars; 4, middle scars; /, lateral scars; s, septum; ¢,
transverse scars. 1. (After Winchell & Schuchert, Min. Pal.)

eh Se

-—— Sane ly Sewn yw ae

BRACHIOPODA—NEOTREMATA. 199

33. L. galenaense Winchell and Schuchert. (Fig. 233.) Ordovicic.
Large, oblong, with nearly straight lateral and anterior margins.
Both valves strongly convex. Surface marked with concentric
striz which at irregular intervals rise into small pustules.
Galena of Iowa, Wisconsin, Minnesota.

NEOTREMATA.

XI. AcrOTRETA Kutorga.

Pedicle valve subconical with apex truncated by pedicle opening.
Posterior margin flattened, triangular and resembling a true cardi-
nal area; this slope is divided medially by a shallow groove
widening downward. Brachial valve usually flat. Surface con-
centrically striated. Differs from Acvothele in having the slope
from the apex to the posterior margin vertical. Cambric.

Fic. 234. a@-c, Acrotretra gemma, side and summit view of ventral valve, and
dorsal valve, all & 3; d, e, Acrothele subsidua, interior of dorsal and exterior of
ventral valves, X 3; f, 2, Acrothele matthew?, interior, exterior and profile views,
<2; h, [phidea bella; 1,7, Iphidea swantonensis, ventral valve and profile, dorsal
valve. (/fand g after Matthew, the others after Walcott. )

34. A. gemma Billings. (Fig. 234, a-c.) Lower to Upper Cambric.
Minute. Brachial valve circular and: nearly flat with beak not
projecting beyond the hinge line and with wide, shallow mesial
sinus. Pedicle valve acutely conical with flat triangular area
whose base forms half the width of the shell.
Montana, Utah, Nevada, Newfoundland.

200 NORTH AMERICAN INDEX FOSSILS.

XIJ. ACROTHELE Linnarsson.

Corneous, subcircular. Pedicle valve subconical with excentric
beak truncated by the pedicle opening, anterior to which are often
two wart-like protuberances. Two such protuberances also form
the umbo of the brachial valve which is marginal. Differs from
Acrotreta in having the slope from the apex to the posterior margin
quite gentle, and in the absence of a cardinal area. Cambric.

35. A. matthewi (Hartt). (Fig. 234, f-g.) Middle Cambric.
Round, extremely flat and thin. The two small wart-like pro-
tuberances are present in front of the foramen of the pedicle
valve.
St. John beds of Newfoundland, New Brunswick.

36. A. subsidua (White). (Fig. 234, de.) Lower to Middle Cambric.

Thin, with transverse diameter slightly exceeding the longitud-
inal. Sides regularly and front broadly rounded. Posterior mar-
gin forms a short and nearly straight hinge line. Brachial valve
flat; pedicle valve somewhat convex near the umbo, with rather

prominent beak.
Utah, Nevada.

37. A. gamagei (Hobbs). Middle Cambric.
Differs from A. matthewi in its more nearly circular form, longer
hinge-line and in having the surface marked by radiating strie.
Surface flat or slightly convex instead of concave in anterior
portion.
Middle Cambric Paradoxides beds of eastern Massachusetts.

XIII. Linnarssonia Walcott.

Calcareous, subcircular, convex. Beak of pedicle valve excen-
tric, perforated by a minute pedicle opening. No cardinal area
on either valve. Differs from Odo/e//a in the absence of the great
lateral muscular impressions and cardinal areas, and also in the
presence of a pedicle opening in the pedicle valve. It is smaller
and more conical than Acrothele. Cambric.

38. L. pretiosa (Billings). Upper Cambric.
Breadth exceeding length with greatest width about the middle.
Beaks very obtuse. Surface covered with very fine lamellose con-
centric striz. Length about 4 inch.
Quebec.

BRACHIOPODA—NEOTREMATA. 201

XIV. Iparpea Billings.

Pedicle valve subconical, strongly elevated at beak; flattened
posteriorly, forming an appearance resembling a true cardinal
area; this area is crossed by a broad triangular ridge (deltidium).
Hinge line nearly straight. Beak excentric, perforated by the
pedicle opening. Brachial valve semicircular, slightly convex.
Surface of shell covered with fine concentric striae. The posses-
sion of the large convex deltidium distinguishes it from Acrotreta.
Cambric.

39. I. bella Billings (Fig. 234, Z.) Lower Cambric.
Small and conical. Pedicle valve about % inch wide by slightly

less long. Surface covered with fine concentric striz which are

continued across the large flat area. These striz are crossed by
a few obscure radiating ones.
Massachusetts, Quebec, Labrador.

40. I. pannulus (White). Lower and Middle Cambric.
Differs from J. de//a in its smaller size (4% inch) and in the charac-
ter of the surface markings; these consist of a fine network of ob-
lique, raised lines, visible under a lens.
New York, Utah, Nevada, Quebec, British Columbia.

41. I. swantonensis Walcott. (Fig. 234, 7.) Lower Cambric.
Hemispheric to semioval outline with high hinge area, marking

the greatest width of the shell and surface marked by concentric

growth lines. (This is also known under the name Faterina labra-
dorica.)
Georgian of Swanton and cues Springs, Vermont.

XV. Trematis Sharpe.

Subcircular. Pedicle valve unevenly convex, depressed in pos-
terior portion. The margin of the pedicle valve is interrupted by
the pedicle fissure which extends almost to the subcentral apex;
internally the sides of this fissure are often thickened. Brachial
valve convex ; apex marginal or slightly projecting. In interior of
pedicle valve radiating sinuses extend from the apex. Surface of
both valves covered with punctures which are arranged either in

_ quincunxial order or in radiating rows and penetrate the outer cal-

careous layers of he shell, but not the inner corneous ones. Or-

-dovicic.

202 NORTH AMERICAN INDEX FOSSILS.

42. T. ottawaensis Billings. (Fig. 235, c.) Ordovicic.
About one inch in diameter. Surface covered with fine radiat-
ing striz and crossed concentrically by fine discontinuous ridges,
Trenton and Lorraine of New
York, Kentucky, Minnesota, On-
tario, Anticosti.

43. T. terminalis Emmons.
Ordovicic.
About half as large as the preced-
ing or smaller; foraminal slit flanked |
by broad depression. Apex of bra-
chial valve marginal, not projecting.
Trenton of New York and Canada.

Fic. 235. a, and d, Trematis }
millipunctata, profileand ventral view, 44. T. millepunctata Hall. (Fig.

X # and enlargement of surface, 235, a—b, d.) Ordovicic.
16; ¢c, Zrematis ottawaensis, brachial

idle, 23h, (Afted Helland Chatice.) Intermediate in size between the

two preceding ; foraminal slit deep,
beak of brachial valve projecting. Surface punctate.

From the Utica and Lorraine of Cincinnati, O., and Coving-
ton, Ky.

XVI. ScuizocraniA Hall and Whitfield.

Subcircular, strongly inequivalve. Pedicle or lower valve flat
or concave; a deep, broad triangular notch extends from near the
subcentral beak to the margin where it constitutes about one sixth
of the periphery. In the apex of this notch is a triangular trans-
verse plate extending about one third the distance to the margin.
Surface covered with concentric lines. Brachial valve convex;
larger than the pedicle valve and extending beyond it on all sides.
Beak marginal or submarginal. Surface with radiating striz,
Ordovicic and Devonic.

45. S. filosa Hall. (Fig. 236, a.) Ordovicic.
Slightly ovate. Surface of brachial or upper valve covered with
fine, even, radiating striz. Pedicle valve strongly marked by irreg-
ular concentric undulations. This species is usually found attached
to brachiopods, particularly to Rafinesquina alternaia. .
Trenton—Lorraine of New York, Ohio, Minnesota, Ontario. |

XVII. Lrincuropiscrna Whitfield.

Upper (brachial) valve linguloid with nearly terminal beak in
typical species ; lower (pedicle) valve discinoid with centrally placed

aw eS ee es ewes SS Se ee eC

i i aol

ee

:
;
4

BRACHIOPODA—NEOTREMATA. .203

beak. Much like Schzzocrania but the brachial valvethas no radi-
ating striz. Pedicle area much elevated internally and cut bya
narrow, open fissure. Devonic—Lower Carbonic.

Fic. 236. a, Schizocrania filosa, 2, specimen with dorsal or upper valve partly
removed, only the margin remaining (4) and showing interior of ventral valve (/),
showing broad notch and pedicle groove g; /, walls of groove (Winchell & Schuchert) ;
b, c, Lingulodiscina newberryt, dorsal and ventral valves, & I (Ohio Pal.); d, Orbicu-
loidea convexa, dorsal valve, XK 1; e, Orbiculoidea missouriensis, X 1, (Ind. Survey);
I, & Discinisca lugubris, exterior and interior of dorsal valve, & 1 (Md. Surv).

46. L. newberryi (Hall). (Fig. 236, 4, c.) Lower Carbonic.
Brachial valve with prominent apex situated near the posterior
margin. Pedicle valve slightly concave with excentric apex and
large oval foramen with deeply depressed margins. Shell thick,
strong and of a lamellose structure. Surface marked by fine con-
centric lines.
Waverly of Ohio, Nevada.

XVIII. Scwsizosorus Ulrich.

Oval, depressed convex. Apex of pedicle valve at terminus of
a rather deep notch in the posterior margin ; apex of brachial valve
subterminal and but slightly elevated with no notch present. Each
valve with a pair of muscle impressions situated posteriorly and
separated by a median ridge extending about one third the distance
to the front of the shell. Devonic.

47. S. concentricus (Vanuxem). (S. ¢runcatus Hall.) (Fig. 237.)
Devonic.
Very small, rarely exceeding one fifth inch in length. Broader

204 NORTH AMERICAN INDEX FOSSILS.

anteriorly and with posterior margin abruptly rounded or truncate.
Surface marked by fine concentric strie and with faint radiating
lines. The brachial valve some-
what resembles a Lingula.
Genesee and Naples of New
York, Kentucky, Indiana.

Fic. 237. Schizobolus concentricus,in- XX. ORBICULOIDEA d'Orbigny
terior of pedicle and brachial valves and ;
exterior of pedicle valve, 2. Corneous, subcircular. Ap-

ices excentric. Pedicle valve
with a narrow pedicle groove beneath the beak extending almost
to the margin of the valve; just behind the beak this groove
penetrates through a long tube obliquely to the interior of the
valve where it opens near the margin; in this it differs from Di¢s-
cinisca. Brachial valve larger, depressed conical. Ordovicic—
Carbonic.

48. 0. lamellosa Hall. Ordovicic.
Apex nearly central. Surface covered with rather strong sub-
lamellose concentric growth lines which become more distinct and
coarser from the apex outward.
Trenton and Lorraine of New York, Minne-
sota, Ontario.

49. 0. lodiensis Vanuxem. (Fig. 238.)
Devonic.

Small, rarely exceeding one-third inch in
diameter. Brachial valve with minute apex.
Pedicle valve somewhat abruptly elevated at
apex, with linear foramen. Surface covered with fine concen-
tric striz and on the anterior half of the shell with faint radiating
folds or undulations.

Genesee of New York, Nevada.

50. 0. convexa (Shumard). (Fig. 236, d.) Upper Carbonic.
Pedicle valve broadly convex with height nearly equal to one half
the diameter ; apex moderately prominent, situated at about one
third the distance from the posterior margin. Surface marked by
distinct concentric growth lines. Diameter about one inch.
Ohio, Indiana, Missouri, Kansas.

Fic. 238. Orbicu-
oidea lodiensis, dorsal
valve, Kom

51. O. missouriensis Shumard. (Fig. 236, ¢.) Upper Carbonic.
Small, averaging about one fourth inch in diameter. Apex
-

BRACHIOPODA—NEOTREMATA. 205

prominent. Surfaces of both valves marked by concentric lines
and fine lamellations.
Ohio, Indiana, Iowa, Illinois, Missouri.

XX. Discrnisca Dall.

Lower or pedicle valve flattened or concave with an elevated inte-
rior pedicle disc perforated by an oval pedicle opening which
passes directly through the shell; externally this: pedicle disc
shows as a depressed area. Upper or brachial valve convex.
Apices of both valves nearly posterior. Shell structure more or
less horny. Miocenic and Pliocenic.

52. D. lugubris Conrad. (Fig. 236, #-g.) Miocenic and Pliocenic.
Small (about % inch in diameter), subcircular. Brachial valve

_ with rather elevated apex which is obtusely pointed and situated
at about one fourth the shell’s diameter from the posterior margin.
Surface strongly lamellose especially over the outer half. Very
faint radiating lines are visible. |

New Jersey, Maryland, Virginia, South Carolina.

XXI. ScuHIzoTRETA Kutorga.

Similar to Ordiculoidea but with thicker shell and with the rela-
tive convexity of the valves reversed, z. ¢., the pedicle valve very
convex and the brachial flattened. Ordovicic—Siluric.

53. S. pelopea Billings. (Fig. 241, a—0.) : Ordovicic.

Nearly circular with strongly elevated pedicle valve and de-
pressed convex brachial valve. Surface marked by numerous

strongly elevated concentric lines of growth. Pedicle opening

small, oval.
Trenton and Lorraine of Iowa, Wisconsin, Minnesota, Ontario,
Quebec.

54. S. tenuilamellata (Hall). Siluric.

Shell thin, larger and more circular than preceding, with thin,

| elevated, prominent, concentric lamellose growth lines; pedicle
_ valve elevated with concave foraminal slope, and elongate exter-
_nal pedicle opening.

Niagaran beds of New York, Ontario, and Nova Scotia.

XXII. RamMeretya Hall and Clarke. ,
Similar to Ovdiculoidea but with pedicle valve very concave and

brachial very convex. Devonic.

206 NORTH AMERICAN INDEX FOSSILS.

55. R. grandis Vanuxem. (Fig. 239.) Devonic.
Large, broadly elliptical. The direction of the foramen in the
pedicle valve is in the shorter diameter of the shell.
Hamilton of New York, Ohio, Indiana, Kentucky.

Fic. 239. Roemerella grandis, a group of dorsal and ventral valves, X 1. (After
Hall. )

XXIII. Cranra Retzius.

Nearly circular, inequivalved, with no pedicle opening but at- —
tached by apex or by the entire surface of the pedicle (lower) valve
which is depressed, conforming to the surface to which it is attached.
Brachial (upper) valve conical with subcentral and posteriorly
directed beak. In each valve is a pair of widely separated muscle
scars near the posterior mar-
gin and a pair close together ©
near the center; vascular sin-
uses digitate. Middle Cam-
bric-Carbonic. |

56. C. scabiosa Hall. (Fig.
240.) Ordovicic,
Small, with irregular out-

line and thickened margins.

Fic. 240. Cvrania scabiosa,a number of Brachial valve thin. Surface

shells attached to a brachial or of Rape of hotinvatves aan ally marlee
esquina alternata, the ornamentation of which

they adopt, 1. (After Hall and Clarke. ) by strongly lamellose growth -
lines. Found adhering to

brachiopods and sometimes unrecognizable because of their assum-
ing the surface features of the body to which they are attached.
Differs from C. modesta in that the average shell is larger and
more rugose.

BRACHIOPODA—NEOTREMATA. 207

Utica and Lorraine of Ohio, Indiana, Illinois, Wisconsin.

57. C. setigera Hall. (Fig. 241, e/) Ordovicic.
Small; often with nearly straight cardinal margin. Surface
marked with quite coarse pustules
or sete which are most distinct near
the margin of the shell.
Trenton and Lorraine of Iowa, Il-
linois, Wisconsin, Minnesota.

58. C. trentonensis Hall. (Fig.
241, c-d.) Ordovicic.

Brachial valve thick, thus differ-
ing from C. scadiosa and not cov-
ered as in C. setigera with elongate

Fic. 241. a, 6, Schizotreta pelopea,
dorsal and ventral valves, the latter

pustules. ety showing small oval pedicle opening;
Trenton of New York, Illinois, c, d, Crania trentonensis, dorsal and
Wisconsin, Minnesota. profile views; e, f, Crania setigera,
: ‘ dorsal and profile views. (After

59. C. lelia Hall. (Fig. 242.) Winchell and Schuchert. )

Ordovicic.

Small, moderately convex, apex of upper valve distant from mar-
gin one third diameter of shell; surface with fine sharp stri, in-
creased sometimes by implantation.

Utica to Lorraine of Ohio and Indiana.

Fic. 242. Crania lelia, four indi-

viduals attached to shell of Strophomena Fic. 243. Crania crenistriata, lat-
planumbona, <1. (After Hall and eral and top views of an elliptical dor-
Clarke. ) sal valve, X 1. (After Hall.)

60. C. crenistriata Hall. (Fig. 243.) Devonic.

_ Brachial valve depressed conical. Surface marked by elevated,
crenulate, radiating strie which reach nearly to the smooth
apex. Boss, 7

Onondaga and Hamilton of New York, Ohio, Kentucky,

q Michigan.

208 NORTH AMERICAN INDEX: FOSSILS.

61. C. modesta White and St. John. (Fig. 466, 2.)
Upper Carbonic.
Average diameter % inch. Brachial valve moderately convex.
Surface concentrically striated.
Ohio, Indiana, Iowa, Kansas.

XXIV. CRANIELLA (CKEhlert.

Large, subcircular or subquadrangular. Pedicle (lower) valve
thin, adhering by its entire surface. Brachial (upper) valve con-
ical with subcentral and posteriorly directed apex. Muscle scars
similar to Cvanza. Differs from Cvaniza in the vascular sinuses of

Fic. 244. 12, 2, Craniella hamiltonie, top and lateral view of dorsal valve; 3, a group
of ventral valves attached to shell of Cypricardella bellistriata, X 1. (After Hall.)

the brachial valve being S-shaped; they start from near the pos-
terior muscle scars and extend to the anterior portion of the valve,
sending to the sides of the valve dichotomizing secondary branches. —
Ordovicic—Devonic.

62. C. hamiltonie Hall. (Fig. 244.). Devonic.
Subcircular. Brachial valve nearly conical with subcentral
apex, pointed in well preserved specimens. Exterior marked by
concentric lamellose striz. Pedicle valve marked by four strong
adductor muscle impressions and by digitate vascular impressions.
Hamilton of New York; Hay and Athabasca rivers, Canada.

XXV. PHoLtipops Hall.

Small, ovate, unattached, equivalved and equiconvex; without
pedicle opening. The edges of the valves are flattened where they
join. The interior of each valve is marked by an elevated and
sharply defined muscular impression which is subtriangular with
the apex of the triangle pointing anteriorly. Ordovicic—Devonic.

BRACHIOPODA—PROTREMATA. 209

63. P. hamiltonie Hall. (Fig. 245.) Devonic.
Ovate with broader posterior end. Apex excentric and inclined:
backward. Surface marked by closely arranged lamellose growth
lines,
Hamilton of New York.
PROTREMATA.

XXVI. Kutoraina Billings.

Inequivalved ; hinge line nearly equal
to the greatest width of the shell.
Larger or pedicle valve usually much
more convex than the brachial; umbo
aa straight or incurved ; median sinus pres-
Fic. 245. Pholidops hamil-- ent or absent. Between the valves is a
ee ik. Pe : et relatively large and broad pedicle open-
ing owing to the rudimentary cardinal
areas. Surface with concentric growth lines. Interior with muscle

scars radiating from the beak. Lower—Middle Cambric.

64. K. cingulata Billings. (Fig. 246.) Lower Cambric.
Pedicle valve convex, arching over to the incurved and pointed
beak; mesial sinus often present. Brachial valve depressed, with

Fic. 246. <utorgina cingulata, ventral, profile and dorsal views, denuded mostly
of outer surface. (After Walcott. )

elevated but not incurved beak. Surface covered with coarse striz
and in older portions with undulations of growth.
Vermont, Quebec, Labrador.

XXVIII. Dicryonetra Hall.
- Subtriangular, biconvex. Pedicle valve with a broad median

sinus and acute and arched umbo. Delthyrium closed by a de-

pressed plate. Brachial valve with a broad median fold; median
septum high. Exterior surface pitted with quincunx, resembling

~Tvrematis. Siluric.

210 NORTH AMERICAN INDEX FOSSILS.

65. D. reticulata Hall. (Fig. 247.) Siluric.
Shell gibbous posteriorly and more attenuate in front. Pedicle
valve with small, acute and closely incurved beak which is flattened
on the back, forming a “ depressed plate.” :
Niagaran of Ohio, Indiana, Wisconsin.

Fic. 248. Sillingsella coloradoensis, dorsal and ven-
tral valves, natural size. (After Hall.)

Fic, 247. Dictyonella
reticulata, dorsal and car-
dinal views, X 2. (After
Hall, ) Fic. 249. Nésusia festinata. (After Walcott. )

XXVIII. BitLincsEL_ita Hall and Clarke.

Small, subquadrate or semicircular; hinge line straight. Pedicle
valve the larger and convex; cardinal area moderately high, ver-
tical or but slightly incurved, with a strong, arching deltidium.
Brachial valve flat or concave ; cardinal area lower than in pedicle
valve but usually also possessing a convex deltidium. Dental
plates continued along the bottom of the valve enclosing a small
muscular area near the apex. Entire surface covered with radiat-
ing plications. Cambric—Siluric.

66. B. coloradoensis (Shumard). (Fig. 248.) | Upper Cambric.
Differs externally from Protorthis billingsz in being less transverse
and in that the brachial valve lacks both sinus and cardinal area.
From Texas to Missouri, Minnesota, Wisconsin, Montana,
Wyoming and Idaho.

XXIX. Nisusia Walcott.

Differs from Ailing sella in that the radiating ribs support irregu-
larly distributed spines on their crests; and in the presence of a
mesial sinus on the pedicle valve and a faint mesial fold on the
brachial. Lower-Middle Cambric.

BRACHIOPODA—PROTREMATA. 211

67. N. festinata Billings. (Fig. 240.) Lower Cambric.

Hinge line straight, usually equalling the greatest width of the
shell. Pedicle valve elevated at the umbo with a high cardinal
area. Surface covered with narrow radiating ribs, increasing both
by bifurcation and intercalation. The spines are located on the
ribs more or less irregu-
larly. An average shell
measures about one inch
in width with length about
one third less.

New York, Pennsylva-
nia, Vermont, Quebec.

XXX. Protortuis Hall
and Clarke.

Like Billingsella but dif-
fering in the absence of a
true cardinal process and 7
in the punctate character of the shell substance. _Middle-Upper
Cambric. | :

68. P. (Billingsella) billingsi (Hartt). (Fig. 250.)
Middle Cambric.
Broader than long, with greatest width at hinge line. Most con-
vex at about the middle and depressed in front. Brachial valve
with sinus. Cardinal areavery narrow. Surface marked by about
thirty radiating striae crossed by distinct lines of growth.
New Brunswick. |

Fie. 250. Protorthis billingst, showing variation
of form. (Dawson and Walcott. )

XXXI. RarFinesguina Hall and Clarke.

Semi-oval; hinge line straight; cardinal area well developed
on each valve. Pedicle valve convex; brachial concave. Mus-
cular area of pedicle valve faintly delimited, consisting of two
broad, flabellate diductor scars enclosing an elongate adductor;
from the margin of the muscular area radiate irregular furrows and
nodose ridges. Brachial valve with bilobed cardinal process.
Entire surface covered with striae alternating in size and crossed by
finer concentric growth lines. Ordovicic-Siluric.

69. R. alternata (Emmons). (Fig: 251.) er Ordovicic.
Broadly semi-oval. Pedicle valve convex, flattened near the

212 NORTH AMERICAN INDEX FOSSILS.

cardinal extremities. Alternation of striz very pronounced on
both valves.

Trenton-Lorraine of New York, Ohio, {Indiana, Illinois, Missouri,
Wisconsin, Minnesota, Manitoba, Anticosti.

Sees

=.

SSS
SSS
—

=

c=

Fic. 251. Rafinesqguina alternata, ventral and dorsal views, <1. (Ind. Geol. Survey. )

70. R. deltoidea (Conrad. ) Ordovicic.

Pedicle valve abruptly deflected at the margin except a small
portion in front. Surface of the valve before deflection covered
with many irregular concentric wrinkles crossed by radiating
strize which, with the exception of one or two prominent ones in
the middle of the shell, are equal. Can be distinguished externally
from Leptena rhomboidalis by its usually deltoid outline and by
the lesser prominence of its corrugations.

Trenton and Utica of New York, Iowa, Missouri, Wisconsin,
Minnesota, Ontario, Manitoba.

71. R. minnesotaensis (N. H. Winchell). (Fig. 252.) Ordovicic.
Very similar to &. alfernata in form and surface features but
usually distinguishable by its smaller size and greater convexity.
Trenton of Kentucky, Tennessee, Iowa, Wisconsin, Minnesota.

’

\\

AWN
\;

ANAK
Sak

N

ZU WN
COUTTS
Fic. 252. Rafinesquina minnesotaensis (var. inguassa), ventral and profile views7of
a shell, and interior of brachial valve, 1. (Min. Geol. Survey. )

XXXII. SrroPpHEODONTA Hall.

Very similar to Rafinesquina but with cardinal margins finely
denticulate, z. ¢., marked by transverse bars which articulate as

teeth and pits. Shell structure coarsely punctate... Siluric-Devonic.
_

BRACHIOPODA—PROTREMATA. 213

Beeehell with radiating plications: ;..; 0.6.0 cisdzevan seensessaadaegeadebeees 83. S. costata,
MIOEELWACT FACILE BLOT F508 Jacinto ozo nana awake ceens bom ademet oan eee Loca eee Rani igs
mee IMERD MEALS Al ooo ids\- caidas wan nnia ae dianens venie Sbiana dee dees Andee sade been Ree uae CR).
(1) Surface with prominent concentric wrinkles .................. 75. S. becket.
(1) Surface with only oblique folds at the hinge margin... 72. S. corrugata.
(1) Surface with very slight concentric wrinkles or none..............2ce0e008 a.
a. Shell very thin. Strize usually. wavy.................. S. perplana.
a. Shell thin. Strive straight’ i5icsicevi dasceweses ccc sae Sy ae varistriata.
eee CHEELE COMCAVG-COMW EM sinc... po1n aus sors Hiedeanvesen@nicncaseantdyiievaeesobedsince vege Cr
(2) Shell large (about 114 inches long or longer)................066
B. Elinge.exthemities TOURER S. -isicdcsccsc dapcesivcch es ben 76, S ae
Po ORL a ime stmt ly, SR CENOR eee eos cinn necs vs tua ahs bsowsnue secaeetendeves ic

¢ Strong concentric strize present, crossing the finer striz. |
‘78. S. patersoni.

T Strong concentric strize absent ...............ceeeesseeeeneeeeeeeeeaenere tf:
{ Shell conspicuously concavo-convex .,........ sas hiean ahah eBie

x Pedicle valve with greatest aauvaatty near thé front. @a.

aa Striscralter mating... cco. vcec ce cseses 81. S. concava.

aa. Striz not alternating......... 80. S. hemispherica.

x. Pedicle valve with greatest convexity in the umbonal re-

ROMs halon tse sbi cns ck akenee 77. S. magniventer.

x. Pedicle valve regularly convex from beak to front.
73. S. profunda.

t Shell slightly convex to flat.........c00000088 74. S. varistriata.

epee ena (about Eine JONG) 4...) i.i od seen even vaqsewetesbyctecdnteadierts oP

c. Radiating striz strongest near the beak.................. 84. S. demissa.

c. Radiating strize not strongest near the beak...... 79. S. imequiradiata,

Pepeome! very small. (about %% inch long)... 0... ccsscadescrcocevsesonsesecnens d.

Greet Pere Ie OXLCTIC AC ac) ascites concwasdehanicta dns 82. S. inequistriata.

d. Hinge line less than greatest width of shell............ 86. S. arcuata.
-72.,8.,corrugata (Conrad.) (Fig. 253.) | Siluric.

Small, nearly flat ; hinge line extended. Surface covered with
_ fine prominent striz. Oblique folds present on the hinge margin.
Clinton of New York, Tennessee.

Fic. 253. Stropheodonta corrugata, with surface enlarged.

_ 73. S. profunda Hall. (Fig. 254.) Siluric.
Large, with width much greater than the length. Brachial valve
very concave with abruptly deflected nate: Surface covered
with fine unequal strie. ‘

214 NORTH AMERICAN INDEX FOSSILS.

Clinton and Niagara of New York, Kentucky, Indiana, Illinois,
Wisconsin.

Fic, 254. Stropheodonta profunda, with enlargement of strize.

74. S. varistriata (Conrad). (Fig. 255.) Siluric-Devonic.

Pedicle valve varying from slightly convex to gibbous, with
slightly elevated beak. Surface usually with alternations of more
or less prominent strize, the sharper ones being separated by several
minute ones.

Manlius and een of New York, Quebec, New Brunswick.

Fic. 255. Stropheodonta varistriata.

————— ee! —— se SS Se

Fic. 256. Stropheodonta ( Leptostrophia) inate interior and exterior of as
valves of different sizes; profile of complete shell.

BRACHIOPODA—PROTREMATA. 215

75. S. (Leptostrophia) beckei Hall. (Fig. 256.) Devonic.
Pedicle valve very depressed convex, with small beak. Brachial
valve nearly flat. Surface marked with strong, close, bifurcating
strize which are crossed by fine concentric lines and by more or
less regular concentric wrinkles. In its surface characters it thus
much resembles Leptena rhomboidalis but differs in being almost
- flat. |
Helderbergian of New York, Kennedy Channel of the Arctic

_ region.

S. (Leptostrophia) magnifica Hall. (Fig. 257:) | Devonic.
_ Very large, with rounded hinge extremities. Pedicle valve
depressed convex at the umbo; brachial valve slightly concave.

_ Fic. 257. Stropheodonta ( Leptostrophia) magnifica, pedicle valve partly removed
aad showing impressions of inner structures ; interior of brachial valve..

R; adiating striz rather faint and regularly bifurcating two or three
t times.
- Oriskany of New York, Maryland, Ontario.

a 7. S. magniventer Hall. Devonic.
} . usually 24 the breadth. Pedicle valve convex in the
_umbonal region with slightly incurved beak. Hinge line some-
times extended. Radiating striz regular and slightly elevated.
Oriskany of New York, Ontario, Quebec.

»

78. S. patersoni Hall. (Fig. 258.) Devonic.
Convex. Distinguished by its form, the pedicle valve being
_ gibbous just in the middle and somewhat hae Sipe ae at the

216 NORTH AMERICAN INDEX FOSSILS.

sides and front. The striz are distant and elevated with many

finer ones between. Strong wrinkles cross concentrically over

the fine strize, being interrupted by the larger ones.
Oriskany—Onondaga of New York,

Ohio, Illinois, Nevada, Ontario.

79. S. inaquiradiata Hall. (Fig.
259.) Devonic.
Pedicle valve somewhat gibbous,

often arching regularly from beak to

front and depressed or concave be-
iG onehlsihapadaoniivater tween ‘the umbo and the cardinal ex-
sont, pedicle valve. (After Hall.) tremities which are somewhat pro-
longed. Beak a little elevated above
the hinge line and incurved. Surface covered with striz, those on
the pedicle valve being often coarse, uneven and somewhat fas-
ciculate; those on the brachial valve are more uniform, the
stronger ones being distant and sharp with wide interspaces |
covered with very fine regular striz.
Onondaga of New York, Ohio,
Nevada, Quebec.

80. S. hemispherica Hall. (Fig.
260.) Devonic.
Form, size and general charac-

ters similar to S. concava from

which it differs in having the sur-
face strize fine and nearly uniform,
instead of alternating; generally
also somewhat more convex than

S. concava. |
Schoharie and Onondaga of

New York and equivalent horizons

of Ohio, Indiana, Kentucky, and

Ontario. . Fic. 259. Stropheodonta inequiradt-
‘ ata, with enlargement of interior of bra-
&1.°S. concava Hall. (Fig.:261-) 01 vale.

Devonic.

Large, with very convex pedicle valve. Cardinal areas high,
almost at right angles to each other. Surface marked by strong
sharp striz2 with finer ones between, all crenulated by concentric
strizc. Profile more concave than that of S. demzssa.

Onondaga and Hamilton of New York. .

BRACHIOPODA—PROTREMATA. ar?

82. S. inequistriata (Conrad). (Fig. 262.) Devonic.
Small. Pedicle valve quite convex. Hinge line extended with
acute and sometimes auriculate extremities. Surface marked by
distant striz with fine, almost invisible striz between.
Onondaga—Hamilton of New York, Kentucky, Indiana, Wiscon-
sin, Ontario.

Fic. 260. Stropheodonta hemispherica.

83. S. costata Owen. | Devonic.
_ Small (hardly 34 inch in diameter). Pedicle valve slightly con-
Vex ; brachial valve nearly flat. Surface covered with about
~ eleven prominent plications. |

Hamilton of Iowa, Michigan.

| 34. S. demissa (Conrad). (Fig. 263.) Middle and Upper Devonic.
: Length and width nearly equal. Pedicle valve strongly convex.
_ Surface striz numerous, strongest and most elevated near the beak
and increasing by intercalation and bifurcation toward the
front.

: Widely distributed throughout North America, especially in
_ Hamilton group.

; 85, S. (Leptostrophia) perplana (Conrad). (Fig. 264.) Devonic.
Thin, slightly convex, often almost flat. Extremities of hinge

_ equal striz, crenulated by fine concentric strie. Differs from S.
_ corrugata in its finer and less prominent strize and in the absence
_ of folds on the hinge margin.

218 NORTH AMERICAN INDEX FOSSILS.

Fic. 261. Stropheodonta concava, lateral and dorsal view of exterior of complete

shell; and lateral and front view of interior of brachial valve showing bilobed cardinal

process, muscular scars; dental sockets, and crenulations of the hinge line, X I.
(After Hall. )

Onondaga—Chemung. Widely distrib-
uted throughout North America.
86. S. arcuata Hall. Devonic.
Hinge line scarcely equalling greatest
width of shell below. Pedicle valve very
- arcuate with sometimes an undefined ele-
_ Fic. 262. Stropheodonta ‘ :
Deeiuiiicia, aedicle vale, VA008 along the center; cardinal extrem-
<1. (After Hall.) ities usually a little recurved, delthyrium

—= te

ee et

ee wee! ae. ll Ue.

ee

~~ S

—

BRACHIOPODA—PROTREMATA. 219

a F IG. 264. Stropheodonta (Leptostrophia) perplana, ventral view, and interior of
brachial valve.

an
Ea, *

closed. Brachial valve very concave. Surface covered with strong,
sharply elevated radiating striz, each alternating with three or five
smaller ones.

Chemung of New York, Iowa, Nevada, Manitoba.

A

-_——Ss XXXII. Puoxrposrroputa Hall and Clarke.

4 ag

_ Differs from Szvopheodonia in the smooth, often nacreous surface ;
marked only with a few squamose growth lines. The interior of
> brachial valve bears three

uscle area. Devonic.

87. P. iowaensis (Owen). (Fig.

, 265.) S. nacrea Hall. Fic. 265. Pholidostrophia iowaensis,
a dorsal, profile and ventral views, I.
(After Hall. )

*%

. Devonic.
Small, semielliptical, having
a bi ‘illiantly nacreous lustre. Brachial valve concave; pedicle valve
vex. Beak small and depressed. Surface apparently smooth,

220 NORTH AMERICAN: INDEX. FOSSILS:

Onondaga and'Hamilton of New York, Ohio, Michigan, Indiana,

Illinois, ees Iowa, Ontario.

XXXIV. SrRoPHONELLA Hall.

Pedicle valve concave; brachial convex. Otherwise like Szvophe-_

odonta. Siluric-Devonic.

88. S.-patenta (Hall). (Fig. 266.) Siluric.
Average shell 134 inches long by 154 inches wide; very con- ©

vex. Surface covered with fine unequal radiating striz crossed by

Hall. )

fine concentric ones. Inner surface of valves thickly covered with
sharp points.
Clinton of New York, Ohio, Indiana, Alabama.

89. S. striata Hall. (Fig. 267.) Siluric.
Almost flat, with fine radiating striz which increase by implanta-
tion. Average shell 5 inch long and 34 inch wide.

ana.

go. S. headleyana Hall. (Fig. 268.)
Devonic,

Length about three fourths the width.
Pedicle valve concave, especially near the
front and with scarcely elevated beak. Brachial valve depressed at
umbo and very convex toward the front. Cardinal area quite wide
and marked by transverse strie. Radiating striae coarse and
sharply elevated, increasing chiefly by implantation. _

Helderbergian of New York, Kennedy Channel and Cape Frazier
of the Arctic regions.

Fic. 267. Strophonella
striata. (After Hall.)

Fic. 266. Strophonella (?) patenta, with enlargement of surface features. (After ’

Niagaran of New York, Kentucky, iia

BRACHIOPODA—PROTREMATA, 221

E Fic. 268. Strophonella headleyana, profile and} ventral view7(exterior) ; interior
profile of pedicle valve. (AfterJHall. )

Fic. 269. Strophonella ampla, dorsal and§profile’views of brachialfvalve; cardinal
w and interior of pedicle valve. (After Hall. )

222 NORTH AMERICAN: INDEX FOSSILS,

gt. S. leavenworthana Hall. Devonic.
Distinguished by its strong geniculation toward the front and by
its concentric wrinkles, presenting a partial superficial resemblance
to Leptena rhomboidats.
Helderbergian of New York.

92. S. punctulifera (Conrad). Devonic.

About four fifths as long as wide. Cardinal area narrow. Striz
strong, increasing both by bifurcation and intercalation and dis-
tinctly punctate. The shell outline is much more abruptly curved
than that of S. headleyana.

Helderbergian of Maine, New York, Pennsylvania, Tennessee,
Nevada, Quebec, New Brunswick, Cape Hilgard and Louis Napo-
leon of the Arctic regions.

93. S. ampla Hall. (Fig. 269.) Devonic.

Large, length from two thirds to three fourths as great as width.
Pedicle valve very concave. Brachia! valve convex in the middle
and flat or concave at the.umbo. Surface covered with angular,
subequal, interrupted or rugose strize which bifurcate two or three
times before reaching the margin. In this
species resupination is more marked, and
the muscle impressions are stronger than
in S. headleyana.

Onondaga of New York, Ohio, Ontario-

94. S. reversa Hall. (Fig. 270.)
| Devonic.
Semi-circular to semi-elliptical, with
hinge line extended; about one third of
the shell (young) normal, after which it
Fic. 270. Sérophonella becomes strongly and abruptly reversed.
veversa, dorsal and ventral ; ,
anpecis. > (AREE Mail) Striz simple, strong and angular near the
beaks, dichotomizing from one to three
times towards the front; also increasing by implantation. Entire
surface punctate.
In the Chemung of New York and equivalent beds of Iowa.

XXXV. STrROPHOMENA (Rafinesque) Blainville.
Like Rafinesquina but with the convexity of the valves reversed.
Pedicle valve slightly convex at umbo, becoming concave towards
the middle; cardinal area conspicuous with convex deltidium ; mus-

BRACHIOPODA—PROTREMATA. 223

cular area subcircular and deeply excavated with an elevated ridge
nearly surrounding it. Brachial valve slightly concave at umbo,
rapidly becoming convex. Ordovicic—Carbonic.

mmreramearly Hat... scarcmctuct cote cath beutereeineiua bode peteenhon sees vopenede 95. S. bellingst.
B. Shell strongly concavo-convex, 2. e., pedicle valve concave and brachial convex., *,

* Shell triangular in outline. Cardinal extremities marked by oblique wrinkles.
98. S. trilobata.

* Shell transversely extended with acute hinge extremities ....................00. (i),
Phy linepes over, Eto dmehi Wide: ie hs inc ccs icahnays Donn das » 96. S. incurvata.

(1) Small, less than Ee CM AWUIES O25. saath ase Seascboct dos 97. S. trentonensts.

* Shell subquadrate with more or less rectangular hinge extremities............ (2)
(2) Of medium size, about 1% inches wide..................... 99. S. neglecta.

ba. mall, “less, Ean ta Cnet AVES. 5. isk a tnasic oh sn dais on dive due nee len aes cue a.

a. Shell not wrinkled on cardinal margin.................. 100. S. rugosa.

a. Shell obliquely wrinkled on cardinal margin.
100a. S. rugosa subtenta.

gs. S. billingsi Winchell and Schuchert. Ordovicic.
Small, usually not exceeding one inch in width. Both valves
nearly flat; beaks scarcely distinct from the cardinal area. Bra-
chial valve marked by a very faint mesial depression for about half
the way from the beak to the front of the shell. Radiating striz
fine and usually of different sizes.
Trenton of Minnesota, Ontario, Manitoba.
96. S. incurvata (Shepard). (Fig. 271, a—d.) Ordovicic.
Of medium size, usually about one and three fourths inches
wide, with greatest width along the hinge-line and with cardinal
_ extremities acutely angular-and deflected. Pedicle valve strongly
concave; brachial quite strongly convex. Radiating striz fine,
crowded, alternating in size and crossed by numerous concentric
lines and a few stronger growth lines.
Trenton of New York, Kentucky, Tennessee, Missouri, Iowa,
Wisconsin, Minnesota, Manitoba.

_ 97. S. trentonensis Winchell and Schuchert. (Fig. 272, @.)

} Ordovicic.
Valves thin. Radiating strize delicate. Cardinal margins

marked by oblique wrinkles. Internal markings undefined.

Trenton of New York, Kentucky, Tennessee, Wisconsin,
Minnesota.

98. S. trilobata (Owen). (Fig. 271, g—/.) Ordovicic.
Hinge line extended. Brachial valve broadly trilobate and very
_gibbous in front. Radiating striz fine and equal.

Trenton of Iowa, Minnesota, Manitoba.

224 NORTH AMERICAN INDEX FOSSILS.

\

AYA
(! il \

Fic. 271. a-d, Strophomena incurvata, a, exterior of convex brachial valve; 4,
interior of pedicle valve ; c, interior of brachial valve ; @, profile ; e—/, Strophomena ru-
gosa, ventral and dorsal views ; g—/, Strophomena trilobata, dorsal and profile views; 2-7,
Leptena unicostata, exterior and profile views of ventral valve. All natural size. (e-/
after Indiana Geol. Surv., the others after Winchell and Schuchert, Minn. Geol. Surv. )

99. S. neglecta (James). (Fig. 272, 2.) Ordovicic.
Of medium size, about one and one third inches wide by an inch
in length with usually the greatest width at the hinge line. Sides
meet the hinge line about at a right angle. Surface covered with
fine, subequal radiating striz.
Lorraine of Ohio, Indiana, Illinois, New Mexico.

100. S. rugosa (Rafinesque MS.) Blainville. (Fig. 271, ef)
, Ordovicic.

Pedicle valve deeply concave, brachial evenly convex. Of
medium size with greatest width at the hinge line. Cardinal ex-
tremities somewhat acute. Surface covered with numerous fine

BRACHIOPODA—PROTREMATA. 2u5

and close radiating striz, usually several smaller between two
larger, the smaller being always shorter than the larger.

Eze

a KAR SOOT LEE EOE

Fic. 272. a@ (upper), Strophomena trentonensis; b, Strophomena neglecta ; dorsal
views. (After Hall.)

Lorraine of Ohio, Indiana, Kentucky, Missouri, Wisconsin,
- Minnesota, Manitoba, Anticosti.

100, a. S. rugosa var. subtenta (Hall). Ordovicic,
| Differs from S. rugosa in being obliquely wrinkled along the
_ cardinal margins.

Occurs with the preceding in the Lorraine of Ohio, Indiana,
Kentucky, Missouri, Minnesota and Anticosti.

XXXVI. Leprana Dalman.

Very similar to Rafinesquina, but wider in proportion to its
_ length and usually with the flatter portions of the valves marked

Hasaliciddwir AN ys

Fic. 273, a. Leptena rhomboidalis ( Niagaran type. )

with conspicuous concentric wrinkles; where these cease the shell

226 NORTH AMERICAN INDEX FOSSILS.

is often abruptly and rectangularly deflected. The whole exterior
is marked with fine radial striations. Ordovicic—Carbonic.
101. L. rhomboidalis (Wilckens). (Fig. 273, a; 273, 0.)
Ordovicic-Lower Carbonic.
Small, usually semicircular; cardinal extremities often much ex-
tended. Pedicle valve slightly convex near the hinge, slightly con-
cave just before the deflection.
Trenton—Waverly; generally distributed throughout America
and Europe.

Fic. 273, 6. Leptena rhomboidalis, interior of brachial valve, profile and dorsal
views. Helderbergian type. (After Hall & Clarke. )

102. L. unicostata Meek and Worthen. (Fig. 271, 7+.)
Ordovicic.
Distinguished from the preceding by the complete absence of
concentric wrinkles and the presence of a small mesial ridge on the
outside of the pedicle valve.
Lorraine of Illinois, Wisconsin, Minnesota, Iowa, Manitoba.

XXXVII. PLEcTAMBONITES Pander.

Small. Pedicle valve convex, brachial concave. Hinge line
forming greatest width of shell. Cardinal areas narrow. Car-
dinal process large and simple, almost filling the delthyrium.
Dental plates continued around the long, narrow, muscular areas.
Surface striz very fine, often alternating in size. Ordovicic—

Siluric.
a

BRACHIOPODA—PROTREMATA. 227

103. P. sericeus (Sowerby). (Fig. 274, a—d.) Ordovicic—Siluric.
Pedicle valve convex in center, deflected at edge. Striz fine,

Fic. 274, a. Plectambonites sericeus,
pedicel valves showing variation. (After
Hall.)

Fic. 274, 6. Plectambonites sericeus,
exterior dorsal aspect, and interior of pedi-
cle and brachial valves, & 2. (After
Hall. )

a alternating with a few slightly elevated ones and crossed by a few
_ weak concentric ones. Surface shining.
_ Trenton—Clinton of New York, Ohio, Kentucky, Indiana, Mis-
_ souri, Wisconsin, Minnesota, Manitoba.

%

_ 104. P. transversalis (Wahlenberg): (Fig. 275.) Siluric.
Pedicle valve very convex, brachial very concave. Hinge line,
_ Owing to the strongly incurved beak of the pedicle valve, is inflected.

a
vg

_.

5 Fic. 275. Plectambonites transversalis, ventral, dorsal and cardinal views; and
i cardinal view of interior of brachial valve. (After Hall.)

a

_ Surface marked by distant and strongly elevated striz with ex-
_ ceedingly fine ones between. The strongly incurved beak of this
_ species is very different from the small beak of P. sericeus which
_ is scarcely distinct from the cardinal margin.

_ Clinton—Niagara of New York, Indiana, Wisconsin, Ontario,
New Brunswick, Anticosti.

’ >
a

228 NORTH AMERICAN INDEX FOSSILS.

XXXVITI. ScHUCHERTELLA Girty.
(Orthothetes of authors.)

Shell flat. Much like Stvophomena. Pedicle valve with well-
developed cardinal area, often irregular. Brachial valve with nar-
row cardinal area. Cardinal process bilobed when viewed from
within, quadrilobed when viewed from without ; a faint median

Fic. 276. Schuchertella subplana. (After Hall.)

septum present. Surface covered with slender radiating striz crenu-
lated by sharp concentric growth lines or fine plications. Sil.—Carb.

105. S. subplana (Conrad). (Fig. 276.) Siluric and Devonic.
Length and width nearly equal. Hinge line extended. Pedicle
valve at first convex, later becoming concave. Striz coarse, sharp
and angular.
Niagaran and Helderbergian of New Mane Kentucky, Tennessee,
Indiana, Illinois, Missouri, Ontario, Nova Scotia, Anticosti.

106. §S. interstriata (Hall).
(Fig. 277.) Siluric.
Semioval, subplano - convex.

Pedicle valve much elevated at

not arcuate, with interstitial striz
beginning below the beak. In-
terior of shell marked with di-
chotomous, Haden striz. All radiating striz crossed by rather
strong growth lines.

Fic. 277. Schuchertella interstriata.

the beak. Radiating striz strong,

BRACHIOPODA—PROTREMATA. 229

Cobleskill of New York, Greenfield of Ohio, etc.

107. S. woolworthana (Hall). (Fig. 278.) Devonic.
Semielliptical. Both valves depressed convex at beak, concave
toward the front. Beaks small. Surface with small, round, crowded,

Fic. 278. Schuchertella woolworthana. (After Hall. )

radiating strize, increasing by interstitial addition, crossed by fine
growth striz and few larger lines of growth. Interior of pedicle
valve marked by a large, flabellate muscular area.

Helderbergian of New York.

108. S. pandora (Billings). (Fig. 279.) Devonic.
Differs from S. chemungensis in the more regularly bilateral posi-
tion of the umbo and in its lesser prominence; also in the less
rectangular form of the shell.
Schoharie and Onondaga of New York, Ohio, Ontario, Nevada.

Fic. 279. Schuchertella pandora.

109. S. arctostriata Hall. (Fig. 280, a0.) Devonic.

Semielliptical or semicircular, often unsymmetrical. Pedicle
valve slightly convex at umbo, flattened anteriorly ; beak often dis-
torted; cardinal area usually unequal on the two sides of the fora-
men. Brachial valve usually depressed convex. Surface covered
__ with sharp, close, crenulated, radiating striz, increasing mainly by

230 NORTH AMERICAN INDEX FOSSILS.

interstitial addition. Length about Y to 3/ inch, width slightly
greater.

Hamilton of New York, Ohio, Kentucky and Nevada.

Fic. 280. a, Schuchertella arctostriata; 6, enlargement of surface; c> Schucher- $
tella perversa. (After Hall.) ;

110. S. perversa (Hall). (Fig. 280, c.) Devonic.

Subelliptical. Hinge line less than the greatest width of shell. ;
Length and width about as two to three. Front broadly rounded.
Pedicle valve very convex at umbo and less so toward the front ;
beak distorted; deltidium prominent and convex. Brachial valve
most convex above the middle, depressed toward the front. Sur- %
face marked with distant, elevated strize, increasing by interstitial
additions ; interspaces crossed by elevated, undulating striz.

Onondaga and Hamilton of New York, Nevada and Ontario.

111. S. chemungensis (Conrad). (Fig. 281, a—d.) Devonic.

Fic. 281. a,b, Schuchertella chemungensis (X 24 ); ce, S. crenistria (K %)3 )
J, Orthotetes heokuk. Cardinal regions of both valves viewed from within ; 7, cardinal
process; s, median septum in pedicle valve; d, dental lamelle; 7, teeth ( %)-

(After Hall.)
Pedicle valve slightly concave, with prominent umbo. Angles
of the hinge line with the sides nearly rectangular.

Chemung of New York, Pennsylvania, Ohio, Nevada, Manitoba. 9

a

aaa

BRACHIOPODA—PROTREMATA. 237

112. S. inequalis Hall. Mississippian.
Hinge line equalling the greatest width of the shell. Brachial
valve very gibbous, with the greatest convexity near the center.
Pedicle valve nearly flat. Surface marked by alternating larger
and smaller radiating striz.
Kinderhook of Pennsylvania, Ohio, Iowa, Utah.

113. S. crenistria (Phillips?). (Fig. 281, ce.) | Mississippian.
Wider than long, with hinge line slightly shorter than width of

_ the shell below. Brachial valve convex medially, pedicle valve
flattened. Surface covered with numerous subequal or alternating
_ larger and smaller radiating striz, crossed by fine and crowded

concentric striz. Length of a rather large specimen 134 inches:

and breadth 2 inches.

Ohio, Michigan, Nevada, Nova Scotia, Feilden Isthmus in lat.
$2°, 43’.

XXXIX. ORTHOTETES Fischer de Waldheim.
(Derbya of authors generally.)

In general like Schuchertella but the pedicle valve is at times
much elevated at the beak and is rarely concave. It differs dis-
tinctly from Schuchertella in the presence in the pedicle valve of a
high median septum extending longitudinally through the center
of the muscular area, which is one third to two thirds the length

of the valve. Carbonic.
114. O. (Derbya) keokuk Hall. (Fig. 281, /) Mississippian.

Differs from O. crassus in its broadly semielliptical outline and

. convexity of brachial valve which is often equal to one third the
_ width of the shell.

Kinderhook-Keokuk of Iowa, Illinois, Indiana, Missouri, Nevada.

115. 0. (Derbya) crassus (Meek and Hayden). (Fig. 282, a—d.)

Upper Carbonic.
Subquadrate, owing to the broadly rounded front and somewhat

_ straightened lateral margins. Pedicle valve nearly flat and usually
_ with a somewhat distorted beak. Brachial valve gently convex in
the middle. Surface marked by numerous. raised radiating striz
crossed by concentric lines and stronger growth lamella. Average
size about I inch in length and breadth.

Widely distributed through central and western North America.

222 NORTH AMERICAN INDEX FOSSILS.

Fic. 282. a-d, Orthotetes crassus,; e-g, Meekella striatocostata. (Ind. Geol.
Surv. )

XL. MEEkELLA White and St. John.

Very biconvex; often subpyramidal; surface plicated. Hinge
line straight, shorter than the greatest width of the shell. Cardinal
area of pedicle valve high, with deltidium which is convex in the
middle and flat along the sides. The prominent dental lamellz
are prolonged forward as septa for half the length of the shell.
Cardinal area of brachial valve linear; umbo gibbous; cardinal
process thin, erect and high, at times almost reaching the apex of
the umbonal cavity of the pedicle valve. Surface of valves, includ-
ing the coarse radiating plications, covered with fine radiating striz.
Upper Carbonic.

116. M. striatocostata (Cox). (Fig. 282, e-g.) Upper Carbonic.

_ Beak usually distorted by being flattened. Surface of both

valves marked by 10 to 14 angular plications, not extending to

the beak and separated by deep angular interspaces. The whole

surface covered with fine radiating striz which in maturity con-

verge upon the crests of the plications and meet one another.
Distributed throughout the western United States.

XLI. Hipparionyx Vanuxem.
Large, like Schuchertella but with a very convex brachial valve
which has no cardinal area; cardinal process high and _ bifid.
Pedicle valve nearly flat, with low cardinal area. Teeth supported

“—

BRACHIOPODA—PROTREMATA. 233

by lamelle which extend as strong ridges entirely around the
large muscular area. Oriskany (Devonic).

117. H. proximus Vanuxem. (Fig. 283.) Devonic.
, Pedicle valve nearly flat; its interior, marked by strong muscular
imprints which occupy a large cardiform space. The imprint of

Fic. 283. Hipparionyx proximus. (After Hall.)

this on the internal mold suggested the name of “horse’s hoof.”
~ Brachial valve convex; surface marked by fine subequal striz.
~ Oriskany of New York, Pennsylvania, Ontario, etc.

XLII. Cuonetes Fischer de Waldheim.

Small. Pedicle valve convex; brachial concave or flat. Hinge
dine straight, forming greatest diameter of shell. Hinge areas
narrow, that of the pedicle valve bearing a single row of hollow
: Resines on its upper margin. Muscular area of both valves divided
bya low median ridge. Cardinal process simple. Surface covered
with radiating strie. Siluric-Carbonic.

234 NORTH AMERICAN INDEX FOSSILS.

A. Shell with radiating strize
I. Pedicle valve with a mesial sinus
* Sinus very deep, giving the shell a bilobed appearance.

134. C. verneuthanus.
*JSinas with amesial foldii tty. i: css e cst ccc dence s vecsdnoe 132. C. mesolobus.

* Sinus shafow and without mesial fold................s.sssoscsonsenesseecnnonnne a.
a. Shell about three fourths inch wide................. 131. C. granulifer.

2, Shell smaller than above... 0.2: scisessc00+ 220 saseesddeoyseateeeeaa Ea

1. Hinge line forming greatest width of shell... 133. C. variolatus.

1. Hinge line equal to or greater than greatest width of shell

Ey, Strats pins wnaiune uv eeip eeteme te ot cle Yas a0 coGuws 126. C. lepidus.

He
** Five to seven oblique.spines on each side of the beak ..................0+- b.
6.. Shell large {about.1. inch wide) ...-..../-cs0sowasessscx+ssea-e es Seeman 2.

2. Jateralistrice curved anteriorly’... 0320\.4.ece00 118. C. jerseyensts.

23 Lateral wstiice straigint.) 6222. ohevos noes dasteeaaenee 122. C. coronatus.

6. Shell small (about 34 inch wide) .. /.. ic.c0cc00s0:0.00000008 een 3.

3. Shell with 100-120 striz near front.......... 129. C. tlinotsensis.

3. Shell with 50—60 strize near front...............00 124. C. scitulus,

** Two to four spines on each side of the beak (except 118 which may have
more )

aiuibialalnis Gin!s mio uioia/ ata sleisielnicinle vie) elalale'e/a]a'e\elain clnisie\e/watsioinicia e(sieic winiciol ola mn c.
0. SPURS WOT COs Seo a wan cw sone tatcde aumento 125. C. setigerus.
65: SPINES DUQUE Fy iets dacoenecoe dives aso ob le sees alt gn tat neey oiee a ee 4.

4. Shell large (three fourths inch wide or more)............-.00:06 T
¢ Striz curving

eases Senaics earaeperelemelebesentar 118. C. jerseyensis.
fr BESTS NOt “CUP VING 2.0 se sasnaneeartades 119. C. hemisphericus.

4. Shell of medium size (1% + inch in general).................0+. TT.
tt Hinge line forming the greatest width of the shell ...... aa.

aa. Umbo of pedicle valve very abruptly incurved at the

Hie Toso. el tev cone ee 123. C. pusillus.

aa, Umbo of pedicle valve not abruptly incurved.

128. C. logant.
tt Hinge line less than the greatest width of the shell
below 66.

OPPO eee EH HEHEHE EEE EEE ET ETE EEE ESE SEE EEE EEE EEEEEE EEE

be SPIER OID So cone Bees cdoaesett 121

. C. vicinus.
66. Two central strize stronger than the others.

126. C. lepidus.
4. Shell small (about one fourth inch wide).... me go

ttt Spines bending abruptly until avallclie ie ae ‘hinge aoe
120. C. mucronatus.

b Aee sa cathe. 2c 127. C. aurora,
JS, OREN SMIOOUNS 2am 5 een ceo yates eet eee ar ec ans Caen ta ch lates dere eoaaeene 130. C. glaber.
118. C. jerseyensis Weller. (Fig. 284.) Siluric.

Fic. 284. Chonetes jerseyensis. (After Weller.)

BRACHIOPODA—PROTREMATA. 235

Concavo- to plano-convex. Pedicle valve depressed convex.
Cardinal spines slightly oblique, about 14. Surface of both valves
with rather coarse radiating ribs, 3 or 4 in a space of 2 mm. at the
anterior margin; the lateral ribs often curve slightly anteriorly as
they approach the margin. Very fine concentric lines also present.
Large shell measures 14 mm. in length by 22 mm. in width.

Decker Ferry of New Jersey, Cobleskill, etc., of New York.

119. C. hemisphericus Hall. (Fig. 285, a—d.) Devonic.
Hinge line often much extended and with 3, 4 or morespines on

FIG, 285. a,b, Chonetes hemisphericus ; c,d, C. pusillus; e, f, C. aurora, with

enlargement of surface; g,%, C. /ogani, with enlargement of surface; 2, C. mesolobus.
(After Hall. )

_ each side of the middle. Pedicle valve very ventricose with promi-
nent, incurved umbo. Shell about 3 inch or 1 inch wide.
Onondaga of New York, Nevada, Ontario.

120. C. mucronatus Hall. (Fig. 286.) Devonic.
Small (about ¥% inch in width), moderately convex with rather
distant and strong radial striz. Cardinal spines, 2-3 on each

Fic. 286. Chonetes mucronatus, X2. (After Hall. )

_ side of the beak, curving out so abruptly as to become parallel to
_ the hinge line.

Oriskany—Hamilton of New York, Nevada, Ontario, Quebec.

236 NORTH AMERICAN INDEX FOSSILS.

121. C. vicinus (Castelnau). (Fig. 287.) Devonic.

Shell’¥%4 -'inch in°width, strongly convex. Cardinal margins
deflected when seen from the convex side. Striz finer and more
closely crowded than in C: mucro-
natus. Spines short and oblique. 2

Hamilton of New York, Ohio,
Wisconsin, Nevada. |

122. C. coronatus (Conrad). (Fig.
288.) Devonic.
Large (about % inch in width),

moderately convex, with numerous

surface striae and 5 or 6 oblique
“Be spines on each side of the beak.

Peete une es ae Interior of pedicle valve strongly pus-

with enlargement of interior of bra-

chial valve. (After Hall.) tulose outside the wide spreading ad-

} | ductor impressions.
Hamilton of New York, Pennsylvania, Illinois, Wisconsin,

Ontario.

123. C. pusillus Hall, (Fig. 285, cd.) - Devonic.
Small (about ¥% inch wide) with somewhat convex pedicle valve ;

Fic, 288.° Chonetes coronatus.” (After Hall. )

i

its umbo abruptly incurved at the hinge extremities which are
usually obtuse. Brachial valve nearly as concave as the pedicle is
convex. Striz but little elevated. —

Hamilton of Illinois, British America.

|
|
|
j
:

BRACHIOPODA—PROTREMATA. 237

124. C. scitulus Hall. (Fig. 289, a-d.) Devonic.
Somewhat gibbous, with numerous (50-60) striz near the front
of the shell and many (10-14) oblique cardinal spines. Interior of
brachial valve strongly pustulose.
Marcellus-Chemung of New York, Pennsylvania, Ohio.

125. C. setigerus (Hall). (Fig.
289, c¢.) |Devonic-Lower
Carbonic.

Moderately convex with three
vertical cardinal spines on each
side of the beak.
Marcellus-Waverly of New
- York, Pennsylvania, Ohio,
_ Michigan, Nevada.

126. Cc, lepidus Hall. (Fig. Fic. 289. a, Chonetes scitulus; 4,
280, d-e.) Pavone same, inbenion of brachial valve, & 23
eer : : d, ¢, C. lepidus, natural size and enlarged ;
; Similar to C. scztu/us but is ¢, C. setigerus, 2. (After Hall.)
smaller, the pedicle valve is
more convex, with a mesial sinus and 4 to 10 marginal spines.
Marcellus-Chemung of New York and Pennsylvania.

127. C. aurora Hall. (Fig. 285, e-~) Devonic-Lower Carbonic.
Differs from C. dogani in its smaller size (about ¥¢ inch wide
_and shorter hinge line, the hinge line being usually less than the
_ greatest width of the shell.

_ Tully—Burlington of New York, Ohio, lowa, Northwest Territory.

i

128. C. logani Norwood and Pratten. (Fig. 285, g-Z.)

: Mississippian.

Pedicle valve quite convex. Greatest width of shell at hinge

line (about % inch). Surface marked by 20-40 fine, dichotomiz-
_ ing, radiating lines, crossed by fine concentric striz.

Kinderhook—Burlington of Ohio, Illinois, Iowa.

129. C. illinoisensis Worthen. Mississippian.

Small (about % inch wide), with five or six oblique spines on

_ each side of the beak. Surface marked by 100-120 very fine dicho-
tomizing striz near the front of the shell.

; Burlington of Ohio, Indiana, Illinois, Iowa.

130. Cc. glaber Geinitz. Upper Carbonic.
Slightly larger than C.-smucronatus, thin, transversely subsemi-

i’

238 NORTH AMERICAN INDEX FOSSILS.

circular. Length less than one-half breadth. Hinge line slightly
longer than greatest width of shell below. Pedicle valve with a
broad and shallow mesial sinus which is at times wanting. Cardinal
margin with four to seven oblique spines on each side of the
beak. Surface smooth except for faint concentric striz.

Kansas, Iowa, Illinois, Colorado, Nebraska.

131. C. granulifer Owen. Upper Carbonic.
Rather large (about 34 inch wide). Distinguished by the broad
shallow sinus in the pedicle valve, the often extended hinge line
and the presence of six to ten oblique spines on each side of the
beak. Surface marked by very fine radiating striz.
Alabama, Missouri, Illinois, lowa, Kansas, Colorado, Arizona.

132. C. mesolobus Norwood and Pratten. (Fig. 285, z.)
Upper Carbonic.
Small. Distinguished by the presence of a lobe or fold in the
mesial sinus of the pedicle valve.
Ohio, Missouri, Illinois, Colorado, New Mexico, Arizona.

133. C. variolatus (d’Orbigny). Upper Carbonic.
Similar to C. granulifer but more convex, very small and with
the sinus of the pedicle valve well-marked.
Ohio, Illinois, Missouri, Kansas, Nebraska, Colorado.

134. C. verneuilianus Norwood and Pratten. (Fig. 290.)
Upper Carbonic.
Small and much wider than long with extended and sometimes
mucronate hinge extremities. Pedicle valve bearing a deep,
rounded mesial sinus, giving the valvea
two-lobed appearance. Hinge line with
four oblique spines on each side of the
beak. Brachial valve bearing an obtuse
median fold. Surface marked by many
fine radial strie. Especially distinguished
= : from other species by its deep sinus and
neutlianus, ater pedicle oked appearance.
valves showing variation.
(Ind. Geol. Surv. ) Indiana, Illinois, Missouri, Kansas, Ne-
braska, Colorado.

XLIII.. Coonostroputa Hall and Clarke.

Differs from Chonetes in having the pedicle valve concave and
the brachial convex; in the absence of a median septum in the
brachial valve and in the bilobed cardinal process.

Stas

ar Me es

Fic. 290. Chonetes ver-

BRACHIOPODA—PROTREMATA. 239

135. C. complanata Hall. (Fig. 291, 2.) Devonic.
Width 1 inch or more. About two thirds as long as wide.
Cardinal spines directed obliquely outwards. Surface with fine,
closely arranged, bifurcating
striz.
Oriskany of New York, On-
tario and Cumberland, Md.

XLIV. CuHonopectus Hall and
Clarke.

Chonetes-like in shape, and
presence of spines but with the
beak of the pedicle valve de-
pressed or distorted, leaving a
flattened area which is probably
a scar from attachment in early
growth. Surface ornamented
with a normal series of con-
centric growth lines and also
with a double oblique series of
wrinkles looking much like the
‘‘engraving on a machine-turned watch case.”

Kinderhook and Burlington (Lower Carbonic).

FIG. 291. a, Chonostrophia compla-
nata; b, Chonopectus fischeri; c, enlarge-
ment of surface of same. (After Hall.)

136. C. fischeri (Norwood and Pratten.) (Fig. 291, 4, c.)
Lower Carbonic.
Semielliptical. Hinge line with five to seven nearly straight
spines on each side of the beak. Surface marked by fine radiating
and concentric striz, beneath which is a “textile” appearance due
to a double set of diagonal lines.
Kinderhook and Burlington, of Pennsylvania, Iowa, Missouri, etc.

XLV. SrropHaLosia King.

Small, semicircular. Hinge line straight. Beak of pedicle valve
with scar indicating attachment. Cardinal area of pedicle valve
especially conspicuous; delthyrium large, covered; teeth large and
cardinal process erect and bifid. Surface of pedicle valve covered
with spines; that of brachial valve spinous, lamellose or smooth.
Devonic—Carbonic.

240 NORTH AMERICAN INDEX FOSSILS.

137. S. truncata (Hall). (Fig. 292.) Devonic.

Small. Pedicle valve gibbous, regularly arched and truncated at
the umbo. Cardinal extremities flattened and auriculate. Brachial
| valve gently concave. Surface of
both valves covered with scattered
soines.

Hamilton, Portage and Ithaca of
New York, Nevada, Ontario. .

XLVI. PropuctTetra Hall.
Fic. 292. Strophalosia truncata.

(After Hall. ) Productoid. Small, with straight

hinge line and narrow cardinal areas.

Pedicle valve strongly convex and produced anteriorly, with

_overarching beak; deltidium present; teeth small. Brachial

valve small, concave; cardinal process usually bilobed. Surface

marked by radiating ridges which bear spines at intervals. Differs

from Strophalosia also in the lack of umbonal attachment. De-
vonic—Carbonic.

A. SPIES MME OUS 478 coaiee anaes veer sceesedhe Sabine pudeammnde gues ban badcant cages ae iat
* Length much preater‘than breadth.....02c20:-sccsennesd ccoteatan 138. P. navicella.

* Length and breadth-about equalie, ......sceuvecssleuoevseenesved ses sqcoiey een ie

I. Spines arranged in concentric rOWS,.. ......c.sccce0eseneceese 142. P. speciosa.

r.. Spines “irregularly scattered |s)...1.2<..sencscenhynstisnds ns dee! og oe eee a.

a. Brachial valye moderately concave... .............0ss0dcast seein a

1’. Lamellose growth lines present...........0000 144. P. pyxidata.

1’. Lamellose growth lines not present....... 145. P. shumardana.

@. ‘Brachial valv€ very CONCAVE... .cc0.nan-i¢o sees danas vee ks ensnnh eee ae

2’. Cardinal margins conspicuously flattened... 139. P. spimulicosta.
2’, Cardinal margins not conspicuously flattened.
146. P. concentrica.

B. Spines few and scattered.............. A snnalneb a bsdidemaaispnes pied aaaiens Satuc uses ian ae,

** Length much greater than breadth, radiating strize coarse.
143. P. arcuata,

** Length and breadth about equal, radiating striz fine.......... 141. P. hallana,
7a enote much less tham btesUth, 224, scam dotancsaceetameries aes 140. P, subalata.
138. P. navicella Hall. (Fig. 293, a—0.) Devonic.

Small; length much exceeding width. Hinge line less than

FIG, 293. @, 6, Productella navicella,; c,d, P. spinulicosta. (After Hall.)

*

BRACHIOPODA—PROTREMATA. 241

width of shell below. Pedicle valve projecting about one third its
length above the hinge line. Surface marked above by fine spines
and below by coarse, spine-bearing ridges.

Onondaga—Hamilton of New York, Nevada.

139. P. spinulicosta Hall. (Fig. 293, c—d.) Devonic.

Differs from P. navicella in the broadly semielliptical or sub-
orbicular outline and in the beak of the pedicle valve which does
not extend beyond the hinge line as in P. xavicella.

Widely distributed in the Onondaga and Hamilton of North
America.

140. P. subalata Hall. (Fig. 294, 2.) Middle Devonic.

Semielliptical or semicircular, usually much wider than high.
Distinguished by the irregularly scattered spines on the surface.
Illinois, Missouri, Minnesota.

Fic. 294. a, Productella subalata,; b,c, P. hallana,; d, e, P. speciosa; f, g, P.
arcuata; h, P. pyxidata; i, P. shumardana. (After Hall, except 4, c, which are
after Walcott. )

141. P. hallana Walcott. (Fig. 294, d-c.) Upper Devonic.
Semielliptical. Length and breadth nearly equal. Pedicle
valve very convex with umbo elevated above the hinge line,
Brachial valve deeply concave. Surface of pedicle valve marked
by fine radiating striz, a few strong growth lines and a few scat-
tered spines. Surface of brachial valve marked only by regular
concentric lines.
New York, Iowa, Nevada, Northwest Territory.

242 NORTH AMERICAN INDEX FOSSILS.

142. P. speciosa Hall. (Fig. 294, d-e.)
Devonic—Lower Carbonic.
Broadly ovate with obtusely angular cardinal extremities.
Pedicle valve regularly arcuate from beak to front and abruptly
depressed between the umbo and the narrow, short ears. Surface
marked by fine concentric striae and on the ears by a few short
wrinkles. The whole body of the shell covered with about 25
concentric rows of spine-bearing tubercles.
Portage, Chemung and Kinderhook of New York, Ohio, ‘jawes
Nevada.

143. P. arcuata Hall. (Fig. 294, 7 g.) Lower Carbonic.
Length exceeding width. Pedicle valve very gibbous with
greatly incurved beak. Differs from P. zavicella in its larger size
and in the almost entire absence of spines on the radial costz, only
a few scattered ones occurring.
Kinderhook of Iowa, Ohio and Missouri.

144. P. pyxidata Hall. (Fig. 294, 4.) Lower Carbonic.
Width greater than length. Hinge line shorter than greatest
width of shell. Pedicle valve somewhat flattened and slightly re-
curved at the cardinal extremities; umbo narrow. Surface of both
valves marked with lamellose growth lines; spine-bearing radiat-
ing ridges at times present on pedicle valve.
Kinderhook of Illinois and Missouri.

145. P. shumardana Hall. (Fig. 294, z.) Lower Carbonic,

Hinge line about equalling the greatest width of shell. Pedicle
valve very convex, gibbous in the middle and towards the umbo;
cardinal extremities flattened. Brachial valve moderately concave.
Surface of both valves covered with fine concentric striz and
strong spine bases. Differs from P. pyridata in the absence of
lamellose growth lines.

Kinderhook of Missouri, lowa and Ohio.

146. P. concentrica Hall. Lower Carbonic.
Small. Hinge line scarcely equalling the greatest width of
shell. Brachial valve deeply concave, almost geniculate in front.
Surface of older portion of valve covered with strong concentric
wrinkles and a few tubercles ; the younger portion with elongate
spine bearing ridges.
Kinderhook of Ohio, Indiana, Iowa and Michigan.

:

BRACHIOPODA—PROTREMATA. 243

XLVII. Propuctus Sowerby.

Semicircular without functional pedicle but probably anchored
by spines of pedicle valve. Pedicle valve large, convex, with
inflated and greatly incurved umbo. Brachial valve small, concave
or almost flat. Hinge line straight; cardinal areas and teeth absent
or rudimentary. Cardinal process large, four-lobed when viewed
from within. A median ridge in each valve separates the muscular
areas. Surface with radiating ribs crossed by concentric lines or
wrinkles, the surface of pedicle valve often studded with spines.
Carbonic.

PER TOT. (OPO NRCHES: WIE) cide du cvesaticay oritannsvinew's 04 vel done sad ve Lamevveneanadedebncs ~
* Surface marked with regular concentric folds from beak to front.
160. P. punctatus,

* Surface marked with very coarse striz and a few concentric wrinkles.
152. LP. semtreticulatus.

feeeedium (between one and two inches wWide)...............cscecscscsecscessessscdecees ae.
MER AIDE SONI G60 5.00. s Shas gene dies vinsie evondwls sh awd alec. ovale cSuicesrdaunws'ns > tanctevae I.

Page terie CTEAtIY IWICUTVER Lis siaasbacagss Coaeetivieecsesaes 148. P. burlingtonensis,

Pee mrem Banal, SIIPRiLY: LNCMOCCE Joc nclveot el ctechs cans cov ebescesccosenas coveredbordt a.
ORGANS SURI COATS. 5.5.2.5, cance pau cash ovaes feSaeacne te 154. P. costatus.

@, Radiating strice very fine... ois .ciceresk isan Deseip testis: 155. L. inflatus.

MM NRE. de BELEN as Suiaiad cic Since wea oa Meh Aaa AAR Loe hire snd cWeN ERR Gn (eb cacegesics ones 2,

2. Hinge line somewhat shorter than width of shell below..................... b.

0, SPMes 1S w ened, SCALLETING., oh .cas- Cus accede ov dawes digesta vee 153. P. cora.

Pee Ce PNP IED OUD enc ceclwansreadaderenion sol « cxpiswdnat nes os.anesiee secon i

1’. Spines in 2 series; one series of large, the other of small spines.
159. P. nebraskaensis.

£” SOPs MN Ge SUIS SEVIES )<.isa4ece exes votes 161, P. symmetricus.
2. Hinge line much shorter than width of shell below (equalling only about

RUBLE CS. WAC ER iscs uisa tz. db bddewtebavss wife sis v'ddecwee Pans 147. P. levicosta.

I RPeES SAT ONE WCE WIGE ) oo cugewsesces seo cecnce vee seagesceusubnees sediedtvevcades tate
*%** Hinge line equal to or exceeding the width of the shell below................ 3-

3. Sides flattened, giving the shell a four-sided appearance from the hinge-

PARE SING SUBUS, - Zins soni gaae nt Sev eees tose ced dedenlex 157. 2. mexicoanus.

Maa MAMET SPREE I gts SNe raph teen teises = | xpi tn'o nh vial dploleniden's v'lcsifow ck Gasabianaees 6s "-

c. Hinge line extended. Broad mesial sinus........ 156. 2. /ongispina.

berate Nine HOt EXtenGets ieee cen aeven vasie st Wiens aes 158. P. muricatus.

*** Hinge line less than width of shell below..........cccccsseseessceeeseeeeceeseceees 4.

Mee IGS WNGKER DY COMCEMENIC WITRKIES) 0... .0ccecscessccteseccatessccdicoses sas d.

PAGS. Big aE: acca 118 Co See eae ees 150. P. marginicinctus.

@: Without a marginal fold: 5.1. cidcissnckssenes Gabo eae: 149. P. disertatus,

4. Surface marked by radiating strize ...............eeeeeee: 151i. P. fasciculatus.

147. P. levicosta White. Lower Carbonic.

Subtriangular in general outline, rapidly increasing in width from
the small, narrow beak to near the front where it is broadly

244 NORTH AMERICAN INDEX FOSSILS.

rounded. No mesial depression present. Hinge line short, form-

ing scarcely more than half the width of the shell. Surface marked

with very fine, thread-like striz. Spine bases scarcely visible.
Kinderhook of Iowa, Missouri, Utah.

148. P. burlingtonensis Hall. (Fig. 295, a—c.)
Lower Carbonic.
Pedicle valve extremely ventricose with beak incurved to near
the middle of the valve; median sinus present, extending from
near the beak to the front. Brachial valve moderately concave
above and abruptly geniculate in the middle. Surface marked by

Fic. 295. a-—c, Productus burlingtonensis; d-g, P. biseriatus. (After Hall and
Whitfield. )

radiating, bifurcating ribs crossed by fine concentric striz. Strong
wrinkles present on the upper portion of the shell and scattered
spines on the middle and lower parts.

Burlington of Illinois, lowa, Missouri, Utah.

149. P. biseriatus Hall. (Fig. 295, d-g.) Lower Carbonic.

Small, longitudinally ovate; hinge line scarcely as long as the
width of the shell below. Pedicle valve extremely gibbous, with-
out sinus and marked by five or six elevated, distant, concentric
undulations which bear on their upper margins a row of elongate
nodes and below this many smaller granulations. Beak attenuate
and extremely arcuate. Brachial valve flat near the front and
marked by 8 or 9 concentric bands set with granulations. -

St. Louis of Kentucky, Indiana, Illinois, Missouri.

BRACHIOPODA—PROTREMATA. 245

150. P. marginicinctus Prout. Lower Carbonic.

Brachial valve subquadrate. A conspicuous marginal fold or
cincture present on each valve. Surface covered with prominent,
rounded, bifurcating coste, the point of bifurcation marked by a
spine base. Fine concentric striz cover the entire surface; these
are accompanied on the older portion of the shell by prominent
concentric wrinkles. Width about 1 inch; length somewhat less.
St. Louis of Illinois and Missouri.

151. P.fasciculatus McChesney. Lower Carbonic.

Hinge line shorter than width of the shell below. Beak small
and appressed. Pedicle valve sharply arcuate above and gently
curving, with a slight depression. Surface marked with moder-
ately fine radiating striz which, when well preserved, have an
irregular knotty appearance caused by the thickening of the strie

Fic. 296. Productus semireticulatus. (Ind. Geol. Surv.)

246 NORTH AMERICAN INDEX FOSSILS.

at the spine bases. Very fine concentric growth lines present in
front and above, a few obscure transverse wrinkles.

Kaskaskia of West Virginia, Kentucky, Ohio, Indiana, Missouri,
Illinois, Utah.

152. P. semireticulatus (Martin). (Fig. 296.)
Lower and Upper Carbonic.
Large, much like P. costatus in form and character of plications,
but larger and with less distinct plications which are crossed by
regular concentric wrinkles in younger stages. Shallow mesial
sinus present giving the shell a bilobed appearance.
Throughout the Carbonic of North America.

153. P. cora d’Orbigny. (Fig. 297, a—0.) Upper Carbonic.
Pedicle valve uniformly convex with beak scarcely projecting

above the hinge line. Mesial fold and sinus absent. Surface

marked with fine radiating striz and with a few scattered spines.
Throughout the Upper Carbonic of North America.

Da AHEM ONS

‘ os Ue HH \\" aN
oh f Hones 1 Ye)
x a ‘ CY

an
can
ai

Fic. 297. a@, 6, Productus cora; c-e, P. costatus; f-g, P. longispina. (Ind.
Geol. Surv. )

154. P. costatus (Sowerby?) de Koninck. (Fig. 297, c-e.)
Upper Carbonic.
Of medium size. ~Pedicle valve gibbous with a broad, shallow
sinus producing a slight emargination at the anterior border.
Beak prominent but only slightly projecting over the hinge mar-_

BRACHIOPODA—PROTREMATA. 247

gin. Brachial valve concave with a very slight mesial fold. Sur-
face marked by coarse radiating plications sometimes bifurcating
or coalescing and crossed by a few concentric wrinkles. A few
strong, scattered spines present on the pedicle valve.

Throughout the Upper Carbonic of North America.

155. P. inflatus McChesney. , Upper Carbonic.
Very gibbous, subquadrate in outline. Beak small and incurved.
Sinus broad, shallow and distinct. Much resembles P. semzreticu-
latus but differs in its smaller size and in the fineness of its radial
striz. Concentric wrinkles present in the posterior third. Spines
few, distant and large.
Indiana and Colorado.

156. P. longispina Sowerby? (Fig. 297, fg.) Upper Carbonic.
Small, much wider than long with extended hinge line and
prominent ears. Pedicle valve gibbous with slightly projecting
beak and broad mesial sinus. Brachial valve concave. Surface
marked by obscure radiating ribs which are obsolete on the umbo.
Spines originally long but usually broken off.
Throughout the Upper Carbonic of the United States.

157. P. mexicoanus Shumard. © Upper Carbonic.
Small. Sides flattened, giving the shell a somewhat four-sided
outline when viewed from the hinge margin. Pedicle valve
strongly arched and without mesial sinus. Surface with 16-20
coarse radiating costz on which are scattered spines.
Nevada, New Mexico.

158. P. muricatus Norwood and Pratten. Upper Carbonic.
Small, semicircular with breadth exceeding length. Curvature
moderate. Distinguished by its surface markings, consisting of
concentric nodose wrinkles and coarse, somewhat nodose striae.
Whole shell covered by small spines.
Ohio, Illinois, Missouri, lowa, Colorado, New Mexico.

159. P. nebraskaensis Owen. (Fig. 298, @-c.)
Upper Carbonic.
Of medium size. Distinguished by the absence of a distinct
_ sinus in the pedicle valve and by the large number of spines scat-
_ tered over the surface of both valves. (See P. symmetricus.)
Ohio, Indiana, Illinois, Missouri, Nebraska, Colorado, Nevada,
New Mexico, Arizona.

248 NORTH AMERICAN INDEX FOSSILS.

160. P. punctatus (Martin). (Fig. 298, d-e.)
Upper Carbonic.
Distinguished by its large size, hinge line shorter than the width
of the shell below, slight mesial sinus in the pedicle valve, small,
incurved beak and numerous regular concentric folds with plain
interspaces. Spines numerous, minute and appressed.
Widely distributed throughout North America.

a. oe ie
ANS)
SAS

AN Sa
Peo Se

X NUR We
oe.

Fic. 298. a-c, Productus nebraskaensis; d, e, P. punctatus (Ind. Geol. Surv. )

161. P. symmetricus McChesney. (Fig. 299.)
Upper Carbonic.
Cardinal area a little less than greatest width of shell. Front
broadly rounded. Pedicle valve without mesial sinus; ears ob-
tusely angular, not well defined from the body of the shell.
Brachial valve moderately concave. Surface covered with small
concentric wrinkles, covered with many minute spines, Width

a

_—

BRACHIOPODA—ORTHIDE. 249

_ about two inches, length slightly less. Distinguished from P.
nebraskaensis by its less convex pedicle valve, its smaller concentric
wrinkles, and especially by having a simple series of small, rather
compressed spines without the additional stout and erect series
of spines.

Upper Carbonic of Indiana, Illinois, lowa and Nebraska.

Fic. 299. Productus symmetricus. (Ind. Geol. Surv.)

OR THEDA:

OrtuHis Dalman.

_ Under this name were formerly placed all forms having in general
a straight hinge line, cardinal areas well developed in each valve,
_ with usually an open triangular delthyrium in each with deltidium
_ developed only in younger growth stages. Dental lamelle well
developed in the pedicle valve and crural plates in the brachial
valve. Surface covered with radiating striz or plications.

This old genus of Ortkis has been subdivided into Orthis (re-
stricted), Plectorthis, Dinorthis, Hebertella, Orthostrophia, Platystro-
plua, Heterorthis, Bilobites, Dalmanella, Rhipidomella, Schizophonia,
Orthotichia, Enteletes.

ge. hell surface radially plicate (2. ¢., radiating lines coarse )/.........-..s.ccenecseseees ‘ah
* Hinge line short (forming about one third the greatest width of shell. Shell
SE Gensel a sene ayaa var semedsseavengadcceWn? LVIIL. Exteletes.

EE TIN Gs MONTERO Posy on Pu ahaa weiss Pate ra J Come asle es haem eke icon Pee dak i waded wan ondens i

1. Pedicle valve flat or concave. Brachial convex............... L. Dinorthis.
RICH VINE (CONV ER Got poh A cia soy sty vyat resis you sassy si cadpaanie Sdaedvedswsees a.

4.2 Brachial waive flat... ..i.51.05 600% Uaeancwiga Duet besivedcav XLVIII, Orthis.

250 NORTH AMERICAN INDEX FOSSILS.

1’. Strong mesial fold on brachial valve and corresponding sinus on
pedicle Walwe a. bic. se adside i ccccancbpe lad ad LIII. Platystrophia.

1’. No mesial fold present. Shallow sinus present or absent.
XLIX. Plectorthis.

B. Shell surface radially striate (7. ¢., radiating lines fine).............se0cseseaceenesees **,
ce Stronply two-tohed = “Wery small iiiciec,cswckas.ceacccccwdeacw diese LIV. Bilobites.

AE NOt MOHIOWEM = (ysoies an vawatte eo bun ape gsaajncsesne chewed anne hawaee Okan eeeuteats Dee 2:

2. Hinge line short (forming about one third the greatest width of shell).. 4.

6. Valves subequally and gently biconvex............ LVI. Rhipidomella.

6. Brachial valve very convex ; pedicle valve much less convex.
LVII. Schizophoria.

Be PAV TNE TOM Gray iite siay nioniseid ow sistan ats Gn ucleld ple bie sind Los Waals at Oemeteieelas Oleaee a fe
os ‘Shell substance punctate snes peswiencess.acorseacssetes LV. Dalmanella.
¢. shell:substance impumetates:.. 02.2 .ccivaavcase aveloas dsntloes (iene kana 2/.
2’. Muscular impression of pedicle valve small, almost confined be-
tween the dental lamellic ............60000. LII. Orthostrophia.

2’. Muscular impression of pedicle valve moderately large, extend-
ing about half the distance from the beak to the front of the
Shell wissen aspaenaneawsssuakes sees aap akeesaae meow ere LI. Hebertella.

XLVIII. Ortuis Dalman (emend Hall and Clarke).

Brachial valve flat; pedicle valve convex. Cardinal area of
pedicle valve elevated and somewhat incurved. Surface covered
with strong, sharp, and comparatively few plications which are
usually if not always simple. Dental lamelle slightly developed.
Cardinal process, a vertical plate lying at the bottom of the brachial
deltidial cavity, and longitudinally dividing it. Camb.—Carb.

162. O. costalis Hall. (Fig. 300, a—d.) Ordovicic.
Hinge line slightly less than the greatest width of the shell.
Pedicle valve very convex with high cardinal area and beak not

Fic. 300. a, 6, Orthts costalis ; c,d, Plectorthis fissicosta. (After Hall.)

incurved. Surface covered by about 30 distant, strong and rounded

plications.
Chazy of New York.
163. O. tricenaria Conrad. (Fig. 301, a—c.) Ordovicic.
Distinguished from O. fladellites by its smaller size and strongly
convex pedicle valve with very high cardinal area. :

Trenton; widely distributed throughout North America.

BRACHIOPODA—ORTHIDZ.. 251

Fic. 301. a-c, Orthis tricenaria; df, Plectorthis plicatella; g-i, P. whitfieldi.
(Minn. Geol. Surv. )
164. O. flabellites Foerste. (Fig. 302.) Siluric.
Semioval, with long hinge line. The coarse plications crossed
by concentric growth lines.
Clinton and Niagara of New York, Kentucky, Ohio, Indiana,
Wisconsin, Ontario.

XLIX. PLecTortTuis Hall and Clarke.

Differs from Orthis (restricted) in the subequal and convex
valves, in having less simple plications and in the comparatively
low cardinal area of the pedi-
cle valve. Ordovicic— De-
vonic. |

165. P. indianola Walcott.
Cambric.
Small, transverse. Hinge
line varying from slightly less
to one fifth greater than the
width of the shell below.
Pedicle valve about twice as
convex as the brachial, with
or without a mesial sinus. Brachial valve with a shallow or deep
mesial sinus. Cardinal areas low. Surface marked with strong or
fine radiating ribs or striz.

Fic. 302. Orthis flabellites. (Pal. N. Y.)

252 NORTH AMERICAN INDEX FOSSILS.

Middle and Upper Cambric of Indian Territory, Oklahoma,
Texas.

166. P. remnicha Winchell. Cambric.

Of medium size, usually slightly transverse. Hinge line varying
in length from nearly the greatest width of the shell to two thirds
the greatest width. Cardinal areasnarrow. Brachial valve slightly
less convex than the pedicle. Surface marked by bifurcating
radiating ribs that vary on shells of similar size from sixteen in the
space of 1 inch to three in the same space.

Saint Croix of Minnesota and Wisconsin, and equivalent forma-
tions of Wyoming, Montana, Indian Territory,

167. P. plicatella Hall. (Fig. 301, d/) Ordovicic.
Broadly semioval. Valves equally convex without depression
or elevation. Length and breadth as 3 to 4. Cardinal area nar-
row. Plications about 20-28.
Trenton—Lorraine of New York, Kentucky, Ohio, Wisconsin,
Minnesota.

168. P, whitfieldi(N.H. Winchell). (Fig. 301, g-z.) Ordovicic.
Larger than P. plicatella with an almost square outline. Cardi-
nal area strongly elevated. Plications numerous.
Lorraine of Illinois, lowa, Wisconsin, Minnesota.

169. P. fissicosta Hall. (Fig. 300, c—d.) Ordovicic.
Of medium size. Slightly and nearly evenly convex. Distin-
guished especially by the character of the coste which are angular
and become two or three times divided toward the margin of the
shell.
Lorraine of Ohio.

L. Dinortuais Hall and Clarke.

Differs from Ov¢/is (restricted) in the convex brachial valve, in
the pedicle valve which is elevated at the umbo and becomes
gradually depressed and finally flat or concave, in the dental
lamellz being extended around a subquadrate muscular area, and
in having an erect cardinal process. Ordovicic.

170. D. deflecta (Conrad). (Fig. 303, a-d.) Ordovicic.
Brachial valve moderately convex. Hinge line usually forming
the greatest diameter of the shell. Cardinal areas at right angles

to each other with broadly triangular delthyrium partially covered,

BRACHIOPODA—ORTHIDE. 253

' by aconvex deltidium. Surface covered with many fine elevated
striz crossed by finer concentric lines.

Trenton of Kentucky, Tennessee, Illinois, Iowa, Wisconsin,
Minnesota.

171. D. meedsi Winchell and Schuchert. (Fig. 303, e—-/.)
Ordovicic.
Biconvex owing to the slight convexity of the pedicle valve.
Hinge line shorter than the width of the shell below. Pedicle

Fic. 303. a-d, Dinorthis deflecta; e-h, D. meedsi,; t-l, D. pectinella (Minn.
Geol. Surv.) ; 7-0, D. subqguadrata (Ind. Geol. Surv.).

valve marked by a broad, shallow sinus. Surface marked by strong,
_ sharp, fasciculated strize crossed by growth lines.
Trenton of Iowa, Wisconsin, Minnesota.

172. D. pectinella (Emmons). (Fig. 303, 7-/.) Ordovicic.
Pedicle valve flattened with a broad central depression. Brachial
valve regularly convex. Surface marked with 22-30 prominent

254 NORTH AMERICAN INDEX FOSSILS.

radii which are as broad as the spaces between and present an
appearance much like the radii of Pecten.

Trenton of New York, Pennsylvania, Iowa, Minnesota, Ontario,
Manitoba.

173. D. subquadrata (Hall). (Fig. 303, m-o.) Ordovicic.
Larger and more subquadrate than the preceding species, the
sides and front being nearly straight. Surface marked by sharp
radiating striz which increase by bifurcation and intercalation.
Lorraine of the Ohio Valley, Missouri, Illinois, Wisconsin, Min-
nesota, Iowa, Manitoba, Anticosti.

LI. HEBERTELLA Hall and Clarke.

Cardinal area about equalling the greatest width of the shell,
that of the pedicle valve being much the higher. Pedicle valve
depressed convex, always less convex than the brachial which is
frequently much inflated. Both valves covered with fine, rounded
and closely crowded striz or plications which increase by interca-
lation ; these are crossed by concentric growth lines. Dental la-
mellz continued as a strong ridge around the obcordate muscular
area. Cardinal process simple, elongate. Shellimpunctate. Ordo-
vicic—Siluric.

A. *Snvall, less‘ thain. 34 sei lene yo, Shc aistisescbadt oa seeadsnratn 175. H. bellirugosa.
B. More tha 9 dich long) 1... 6..02 5 Pocasndedea dette conse dees sodebease nea sceete ade eeeaen =;
* ‘Broad sinus present on pedicle valve: 2; 2.1.32... <0000secneasencdenenwenna sagen Ts

Eo APERCE SUTIBCE f2ia wind vas. ctuinet an eBenedn's sine eae os 0 <cadialasise gia elec bane en a.

a. Strie irregularly bifurcating. Beak moderately high.
177. H. occidentalis
a. Strie stronger and regularly bifurcating. Beak very high.
178. H. sinuata.

Re OUR Ce PORES, oc pics cost Gendo@es sa avid Vows oa ss a= opeon aeaaemene 174. H. borealts.
* Wo Sits Present:on Pedicle VAIVES. onic. dc vce, 1525s eceecdeenaee 176. H. insculpta.
74. H. borealis (Billings). (Fig. 304, a—c.) Ordovicic.

Both valves convex. Hinge line somewhat less than the width
of the shell below. Brachial valve with a low, undefined mesial
prominence; pedicle valve with a broad and very shallow mesial
sinus. Surface covered with about 40 radiating ribs. Much like
Plectorthis plicatella, but differs in the presence of the fold and
sinus.

Chazy—Trenton of Kentucky, Tennessee, Wisconsin, Minnesota,
Ontario, Quebec

»

BRACHIOPODA—ORTHIDZ. 255

Fic. 304. a-c, Hebertella borealis (Geol. Surv. Canada); d, e, H. bellirugosa
{ Minn, Geol. Surv.) ; (-2, H. occidentalis (Ind. Geol. Surv.).

175. H. bellirugosa (Conrad). (Fig. 304, ad-e.) Ordovicic.

Small (less than ¥% inch long), subquadrate. Valves of nearly
equal convexity. Brachial valve with a conspicuous mesial sinus
and pedicle valve also at times with a sinus. Surface striz crossed
by imbricating lamellz which give the shell a rugose appearance.

Trenton of Kentucky, Tennes-
see, Wisconsin, Minnesota, Iowa,

176. H. insculpta Hall. (Fig.
305.) Ordovicic.
Distinguished from /7. delhru-

gosa by its larger size (over %

inch long), more convex brach-
ial valve and less prominent
concentric growth lines.

Lorraine of Ohio, Indiana, IIli-
nois, Wisconsin, Iowa.

Fic. 305. Hebertella insculpta. (After
Hall.)

177. H. occidentalis Hall. (Fig. 304, 7“) Ordovicic.

Length and breadth about as 5 to 7. Cardinal area of pedicle
valve high; delthyrium triangular, large and open. Pedicle valve
high at beak, depressed into a broad sinus toward the front.
Brachial valve regularly and strongly convex with greatly incurved
beak which projects slightly beyond the hinge line. Surface
marked by elevated, subangular striz crossed by fine concentric
growth lines.

256 NORTH AMERICAN INDEX FOSSILS.

Lorraine of Ohio, Indiana, Illinois, Missouri, Wisconsin, New
Mexico.

178. H. sinuata Hall. (Fig. 306.) Ordovicic.
Very similar to HZ. occidentalis from which it differs in the more
elevated and acute beak of the pedicle valve and in the stronger
and more regularly bifurcating striz.
Lorraine of Ohio.

Fic. 306. Hebertella sinuata. (Ohio Surv.)

LII. OrTHOSTROPHIA Hall.

~ Pedicle valve depressed convex; brachial very convex. Surface
striated. Cardinal process elongate and simple. Muscular area in
pedicle valve deep and narrow,
almost confined to the space be-
tween the dental lamellz. The
vascular markings are very distinct
on both valves. Siluric-Devonic.

179. 0.( ?) fasciata Hall. (Fig.
307.) Siluric.
Distinguished by its small size, often extended hinge line and

bifurcating and fasciculate striz.
Niagara of New York.

Fic, 307. Orthostrophia (?) fasctata.
(After Hall.)

BRACHIOPODA—ORTHIDZ. 257

180. O. strophomenoides Hall. Devonic.

Beak of pedicle valve but little elevated above the hinge line;
that of brachial valve somewhat the more prominent. Surface
marked by a distinct, narrow mesial elevation on the pedicle valve
from beak to front and by a corresponding depression on the
_ brachial valve.

Helderbergian of New York, Maine, Tennessee, etc.

LIT. PLatystropuia King.

Exterior spiriferoid but interior lacking the calcified brachidia of
Spuifer. Hinge line long and straight. Cardinal areas almost
equally developed on both valves, thus differing from Sporsfer.
Both valves very convex, the brachial the more so, with a strong
median fold on the brachial valve and a corresponding deep sinus

Fic. 308. a,b, Platystrophia crassa; c, d, P. lynx,var. (Minn. Geol. Surv.) ; e-7,
P. acutilirata (Ind. Geol. Surv.).

on the pedicle valve. Both valves marked by strong sharp pli-

cations which extend over sinus and fold. The teeth are thick and

very prominent. Ordovicic—Siluric.

258 NORTH AMERICAN. INDEX FOSSILS.

A. Height and breadth about equal. Shell very gibbous............... 181. P, crassa

Maem eC eRCER OX CCECMIMO MN GIS NE c22 ceciellina's aentnen! sivtiWa 0s vances slemsinieieeislapinlonle’s tales onpemene
* Hinge line rounded at extremities and less than the greatest width of shell.

183. 2. lyme

Babine Mime EX temde ds i. iui. vekgn ce dvanesossed ocseercen sctbacave asekqecssae nn I.
Distt Won py CANONS AMM SINNIS Io es viele ache ddan value Decree nx eae 185. P. biforata.

1, TRreeiOr More PUCAHONE IN SIMUS ic... cece ens tidasa rose cwasedecnene aan a.

a. Hinge line usually with mucronate extremities, Plications many. I’,

De oP OVE, PRONOUNCER. 5 occa sinda'nacion sar os'esemerdiskluae oh 185. P. diforata.

1431 Held Mot pronounced: iiics hace des cecaecdaeeed oes 182. P. acutilirata.

a. Hinge line extremities not mucronate. Plications wide and few.
184. P. laticosta.

181. P. crassaJames. (Fig. 308, a—0.) Ordovicic.
Hinge line short with rounded extremities. Shell as wide as

long. Both valves very gibbous. (Cf P. costata Pander.)
Lorraine of Ohio, Minnesota, Manitoba.

182. P. acutilirata (Conrad). (Fig. 308, e-z.) Ordovicic.
Usually much extended on hinge line which is often mucronate.

Plications simple, from 10 to 18 on each side of fold and sinus

with usually only three in the sinus and four on the fold.
Lorraine of Indiana, Ohio, Missouri and Louisiana.

183. P. lynx (Eichwald). (Figs. 308, c-d,; 309.) Ordovicic.
Large, wider than long. Hinge line usually less than the

greatest width of the valves, with obtusely angular extremities.

Plications (16-24) angular, with three (1-7) in the mesial sinus.

Trenton of New York, Lorraine of Ohio, Kentucky, Indiana, etc.

184. P. laticosta Meek. Ordovicic.
Of medium size, wider than long, with hinge line forming

greatest width of shell. Plications large and few, 5 to 7 on the

lateral slopes and I to 3 on the sinus and 2 to 4 on the fold; those

marking fold and sinus are irregular and of different sizes.
Lorraine and Richmond of Ohio valley.

185. P. biforata (Schlotheim). Ordovicic and Siluric.

Semielliptical or subquadrate, wider than long. Cardinal ex-
tremities varying from submucronate to obtuse. Usually about 2
(2-9) of the sharp plications are in the sinus while about 3 (3-10)
mark the fold, rapidly increasing in strength as they approach the
front.

Trenton of Hudson and Champlain valleys and Clinton of New
York, Ohio, Kentucky and Indiana.

BRACHIOPODA—ORTHID£. 259

LIV. Bitosires Linnzus.

Small, strongly bilobed. Hinge line short. Teeth and sockets
obscure. Cardinal process small and simple. Shell substance
punctate. Siluric-Carbonic.

186. B. bilobus (Linnzus). Siluric.

Cardinal extremities auriculate. Pedicle valve very convex:
brachial valve varying from slightly concave to slightly convex.

Fic. 309. Platystrophialynx. Inter- Fic. 310. Szlodites varicus. Exterior
ior of pedicle valve & 1. A, delthyrium; dorsal view X 3 and interior of brachial
0, ovarian impression ; #, pedicle muscle valve much enlarged; 7, cardinal process ;
scar; 7, diductor muscle impression; ¢, ¢, crura; @,adductorscars. (After Hall.)
teeth ; v, vascular markings. (After Hall.)

Differs from 4. varicus in its smaller size, its more extended hinge
line, greater inequality of the two valves and in its few radial striz.
Niagaran of New York, Indiana, Wisconsin.

187. B. varicus Conrad. (Fig. 310.) Devonic.
Ventricose. Cardinal area of pedicle valve the higher. Fora-
men high and narrow. Surface unequally striated, only a few of
the strie being visible to the naked eye. Differs from 4. dzlobus
in its larger size, greater gibbosity. and proportionally shorter
hinge line.
Helderbergian of New York, Tennessee, New Brunswick.

LV. DALMANELLA Hall and Clarke.

Plano-convex or subequally biconvex, subcircular in outline.
Pedicle valve elevated and arched over the cardinal area. Surface
covered with fine, rounded, bifurcating strize which curve very con-

260 NORTH AMERICAN INDEX FOSSILS.

spicuously from the umbo to the sides of the valve. Teeth promi-
nent. Ordovicic—Devonic.

A. Radiating striz prominent and coarse.......... Pent Rr a dnt 188. D. testudinaria.
Ps PR UOUNOAN UD EN SET MEN IDES ohne Warr ac vid acl a ye sein! det ous anigeamabou eds veg siph tna Cee %,
* SMeT Sia Akers tania ACR WIE) cc. scsi <cowssorodrcdsv enn veay soe Sovcsbene taka i

Tope CCGle ww Bive Wadler WAN LOW 0.2 demise na ce pen teeaetinasyeecc sun a.

RSE AMEN she actnctst ie cains vines mak acttite okamaiers oehve 189. D. emacerata.

Mag O OO VOM eg creeson aks vases sien asinep't dv Eon capes seaaReS 190. D. subequata,

E, (Pedicle valve Jonger than Wides.di..i<ns,sasieodtaccnaase Ig!. D. elegantula.

Or ENE MAS CAE. 94 STOR WIE s os foes ag dda uandinsivenubansdacisianse anaie tonya ceneeee ers

2. Brachial valve slightly convex and with broad mesial depression.
193. J. subcarinata.

2. Brachial valve strongly convex and with slight mesial depression.
192. D. perelegans.

188. D. testudinaria (Dalman). (Fig. 311, a-e.) Ordovicic.

Pedicle valve convex at umbo, rapidly decreasing in height
before the edge of the shell is reached; cardinal area high; umbo
but slightly incurved. Brachial valve very slightly convex or
depressed. Surface marked with very prominent radiating striez
crossed by faint concentric lines.

Chazy—Lorraine throughout America.

189. D. emacerata Hall, (Fig. 311, 2-7.) Ordovicic,
Distinguished by its thinness, the brachial valve being flat and
the pedicle valve depressed convex. Cardinal area almost linear.
Surface finely striated.
Utica of Ohio, Missouri, Minnesota and Quebec. \

MEAL ENN
Aa

Fic. 311. a-e, Dalmanella testudinaria; f-h, D. subequata ; 72—-m, LD. emacerata.
(Minnesota Geol. Surv, )

BRACHIOPODA—ORTHIDZ.. 261

190. D, subequata (Conrad). (Fig. 311, /-“.) Ordovicic.
; Both valves convex, the pedicle valve more than the brachial
especially at the umbo. Surface marked with fine radiating strie
which are perforate at intervals.
Trenton of Missouri, Wisconsin, Minne-
-sota, lowa, Quebec.

191. D. elegantula (Dalman). (Fig. 312.)
‘ Siluric.
Pedicle valve very strongly convex with a
high, narrow cardinal area. Brachial valve
nearly flat and marked with an undefined
median sinus. Striz fine and close set.

‘ : ; cS Fic. 312. Dalmanella
Clinton and Niagara; widely distributed epcaniula, (After Hall.

throughout eastern North America.

192. D. perelegans Hall. (Fig. 313.) Devonic.

Pedicle valve convex but not subcarinate as in JD. sudbcarinata.

Fic. 313. Dalmanella perelegans. - (After Hall.) -

_ Brachial valve very convex and only slightly depressed medially.
In other respects very like D. sudcarinata.
Helderbergian of New York and Tennessee.

193. D. subcarinata Hall. (Fig. 314.) Devonic,

Pedicle valve very convex, subcarinate along median line; umbo
strongly incurved over the cardinal area. Brachial valve slightly

262 NORTH AMERICAN INDEX FOSSILS.

convex near the hinge with an undefined depression along the
median line which broadens rapidly anteriorly. Strize very fine,
numerous and irregularly bifurcating.

Fic. 314. Dalmanella subcarinata. (After Hall.)

Helderbergian of New York, Tennessee, Missouri, Wiscon-
sin, Nova Scotia.

LVI. RHIPIDOMELLA Oehlert.

Shell almost circular. Both valves gently convex. Hinge line
short. Slight median depression present in each valve. Surface
covered with fine, hollow striz, often opening on the surface.
From the base of the-two strong teeth on the interior of the pedicle
valve acurving ridge extends forward and borders the large flabel-
liform muscular scars which extend one third or more the length
of the valve and are deeply impressed. Shell structure punctate.
Siluric—Carbonic.

A. Rounded posteriorly, z. ¢., beak but slightly elevated above hinge line........... =
* Large (average widthvover % inch) «..c2240.<sanseaeneses eben sepan ese abate &
1. ‘With broad medial depression in pedicle valve ........::,...-+ssssasmeunene a.

a. Outline usually transversely oval ...ssccc- cccceeeed ccs oo00ens onsen 2

a7; “Posterior border curved |. <aassies tee onsnetessetaoes 195. &. oblata.

r42-sPosterior border. straight -:/ 05 oe. cs sasgeaten ate taveones 196. &. alsa.

4, Omiing vemenlats seo. Vecis enes snd oteepead timated 198. A. vanuxemt.

1. Without broad depression in pedicle -valve...5...0...+c0ssss.- s00eseeeeeaam b.

be Beaks prominentyiig .iecs seccscsetes Rk pe 197. &. livia.

¢: sbeaks mot promiiient 255 tiscie5. 05 arn cee deena see -vonee vee meen ‘cone pctis

2’, Radiating strie indistinct /..4.\svcatescnee.sicas 202. R. michelint.

20). Radiating \Strice StrOnR 5.0634: alnnse women gto 200. A. penelope.

* Small (width not exceeding % inch))...¢...-0. becieoes noeneaer oe. «0h een 2.
2) Sinus present in/bothywalves. ics. sesmcksesdedectastetvenese 201. XR. thiemet.

2. Sinus absent in pedicle Wal veicss.2) ssodeedesd so, taneksans geese 205. A. pecost.

BRACHIOPODA—ORTHID&. 263

B. Pointed posteriorly, 7. ¢., with somewhat elevated beak...... Er ee
** Small (width not exceeding 24 inch))....2.... -..seveos sé salads. @ahantineeamaeee 3.
3. With slight mesial depression. Beak not incurved...... 194. &. hybriaa.

3. With strong mesial sinus. Beak of pedicle valve somewhat incurved.
204. 2. dubia.

wit medium size (not below 2 inch In Width) 3.5 0.0+- 0 sstsmenmcvidurteoareucnaanieah 4.
Sra XU VEU POSLETIONY..c.dvncebeceasuwven dems Tiusr oni Sue tee deta . 199. R. leucosia.
ehetralmit POSTEDLONLY: ics aus 5: peeckeae = cehus aucune teas . 203. R. burlingtonensts.

194. R. hybrida (Sowerby). (Fig.
i. 315.) Siluric. <>
Width exceeding length. Valves

very nearly equal. Beaks scarcely
‘incurved. Pedicle valve marked with
a broad, undefined depression.

Niagaran of New York, Kentucky, am
Tennessee, Ohio, Indiana, Missouri, 5... ie wiagetin la byleide.
Nova Scotia. _ (After Hall.)

195. R. oblata Hall. (Fig. 316-317.) Devonic.
Large, transversely oval. Pedicle valve convex at beak and
_ concave toward the front. Brachial valve very convex. leaks of

Fic. 316. Rhipidomella oblata.

(After Hall.)

a re

Fic. 317. Rhipidomella oblata internal molds. (After Hall.)

264 NORTH AMERICAN INDEX FOSSILS.

both valves of slight and nearly equal elevation. Surface faintly

striated.
Helderbergian of New York, etc.

196. R. alsa Hall. (Fig. 318.) Devonic.
Large, nearly transversely oval but hinge line somewhat ex-

tended, producing for some distance a straight posterior border.

oar 5
ae oer

Were

Fic. 318, Rhipidomelia alsa and internal molds. (After Hall.)

Pedicle valve depressed convex, becoming nearly flat. Brachial
valve convex and marked by a mesial sinus. Differs from 2.
oblata in the absence of the depression in the pedicle valve, in the
more extended hinge line and in the presence of a sinus in the
brachial valve.
Schoharie of New York, Michigan, etc.
197. R. livia (Billings). (Fig. 319, a-d.) Devonic.
Differs from A. vanuxemz in the lesser convexity of the brachial

Fic. 319. a-b, Rhipidomella livia, c, R. michelini (after Hall); d-g, R. dubia,
(After Whitfield. )
valve and in the absence of a mesial sinus, while the beak is shorter,
not rising to nearly the same height as in the pedicle valve. Its
suborbicular form distinguishes it from &. Zeucosza. 7
Onondaga of New York, Ohio, Ontario, Quebec.

BRACHIOPODA — ORTHID-. 265

198. R. vanuxemi Hall. (Fig. 320, a—c.) Devonic.
Subcircular. Pedicle. valve nearly flat, becoming moderately
convex near the beak. Brachial valve convex.
Onondaga—Hamilton of New York, Ohio, Michigan, Illinois,
Iowa, Ontario.

199. R. leucosia Hall. (Fig. 320, d-c.) Devonic.
Broadly ovate with pointed beak. Both pedicle and brachial
valves convex.
Hamilton of New York, Maryland.

200. R. penelope Hall. (Fig. 320, fg.) Devonic.

Large, subcircular. Brachial valve regularly convex and slightly
depressed medially. Pedicle vaive depressed convex above, be-
coming flat or concave toward the margin but lacking a sinuosity

in front. Beaks not prominent.
Hamilton of New York.

201. R. thiemei (White). Devonic and Mississippic.

Usually a little wider than long. Convex at beak but flattened
toward the front owing toa broad, faint sinus in each valve. Beak
of pedicle valve short, elevated and slightly incurved beyond the
cardinal area. Brachial valve the deeper. Differs from 2. vanux-

Fic. 320. a-c, Rhipidomella vanuxemi; d-e, R. leucosia; f-g, BR. penelope.

°°?)

(After Hall. )

266 NORTH AMERICAN INDEX FOSSILS.

emz in its smaller size, greater gibbosity and in the more elevated
and incurved beak of the pedicle valve.
Chemung of New York and Kinderhook of Iowa.
202.) Rk. michelin (1. Eveille).. (Fig. 319, .c.) Mississippic.
Quite similar to R. vanuxemi but differs in the parallel direction
of the dental lamellz and in the character of the radial striz.
Waverly of Pennsylvania, Ohio, Kentucky, New Mexico.

203. R. burlingtonensis Hall. Mississippic.
Of medium size, subcircular. Valves subequally convex. Beak
of pedicle valve extended and cardinal area high.
Burlington of Iiinois, lowa, Missouri.
204. R. dubia Hall. (Fig. 319, @-g.) Mississippic.
Distinguished by its small size, nearly equal convexity of the two.
valves, the prominent beak of the pedicle valve and the distinctly
defined sinus of the pedicle valve.
St. Louis of Kentucky, Indiana, Illinois, Missouri, Iowa.
205. R. pecosi (Marcou). (Fig. 321, a—c.) Carbonic.
Small. Length at times exceeding breadth. Pedicle valve often
flattened toward the front and lacking a definite mesial sinus.
Brachial valve more convex than the pedicle valve. Radiating
strize crossed by fine concentric growth lines-and near the front by
imbricating lines.
Throughout the Carbonic of North America.

‘ Yoke
ATS ‘ N
aN)

f \ ‘
2 a
pra}
Eats poiwi2 3)

Fic. 321. a-c, Rhipidomella pecosi; d-f, Schizophoria striatula (Ind, Geol. Surv.) »
gh, S. tioga. (After Hall. )

BRACHIOPODA—ORTHID£. 267

LVII. ScuizopHoria King.

Pedicle valve depressed convex, becoming slightly concave
toward the front. Brachial valve very convex. Hinge line short.
Cardinal areas moderately high. Plications rounded, hollow and
exceedingly fine. Muscular area of pedicle valve has elevated
margins and is deeply sunk in the substance of the shell. Shell
substance very punctate. his genus differs from Hebertella
principally in its much shorter hinge line and its punctate shell.
Siluric—Carbonic.

Men iuenpth exceeding. breadth............sssce+ss acaauvnatseersaseeree 210. S. macfarlani.
EME EC OCC! DIT LOT OLE, 22 sie ke sin csidesn vss. nnicaienien tic acesah vmcbiade seus 4a adive can aan tenner’ *.
ree FaAScieMlate, 2. €., 1 DUCES, j.4i.c0c08s vc noe coc etcacsevsseevocceses 211. S. dioga.
RRR M aso ECIIL GN FAP ois. x > sate ais ait nator otk <et > 6balines we'd ova puvincodetoas ravens tneyes i:

I, Hinge line quite long, forming nearly the greatest width of shell. Shell

large, often exceeding I inch in width.................... 212. S. swallovi.

1. Hinge line equalling only about half the width of the shell............... a.

a. Beak of pedicle valve prominent and pointed..................0eeeeees i’.

1’, Beak of brachial valve not strongly arched, vascular impressions

not bifurcating but diverging.............. 206. S. multistriata.

1’. Beak of brachial valve strongly arched, vascular impressions not

bifurcating, but parallel or converging...... 208. S. tulliensis.

1’, Beak of brachial valve arched, vascular impressions bifurcating.
207. S. propinqua.

a. Beaks of both valves about equal and not pointed.......... a sew ca 2.

2. COraim al ALEAS TALCOW sive cidn ieee in onde own 213. S. resupinoides.

2". Cardinal: areas moderately high \)..../5:.......... 209. S. striatula.

206. S. multistriata Hall. (Fig. 322.) Lower Devonic.

Of medium size. Ped-
icle valve with broad,
‘undefined sinus and
prominent, slightly in-
curved beak. Brachial
valve with obtuse beak.
Hinge line forming about
half the width of the
shell. Surface marked
by fine, equal, radiating
striz. Concentric growth-
lines very faint. Vascu-
lar impressions slightly
diverging forward but Fic. 322. Schizophoria multistrtata. (After
not bifurcating. Hall.)

Helderbergian of New York. :

268 NORTH AMERICAN INDEX FOSSILS.

207. S. propinqua Hall. Middle Devonic.
Brachial valve somewhat more gibbous than in S. mu/tistriata,
and pedicle beak and area generally somewhat more arcuate.
Vascular impressions on interior of valves bifurcating from one to
three times before reaching front of shell.
Onondaga of New York, Ohio, etc.

208. S. tulliensis Hall. Upper Devonic.

Differs from S. propingua and S. multstriata in being more
gibbous, with the beak of the brachial valve more elevated and
arching, and in having the divisions of the vascular impressions
running nearly parallel to each other or slightly converging, without
bifurcation.

Tully of New York, and equivalent horizons of Nevada, etc.
209. S. striatula (Schlotheim). (Fig. 321, af)

Middle and Upper Devonic,

Brachial valve sinuate in front. Pedicle valve with a broad, un-
defined sinus, sometimes incurving the margin of the shell. Sur-
face very finely and evenly striated.

Widely distributed throughout North America.

210. S. macfarlani (Meek). Middle and Upper Devonic.

Very gibbous. Length in adults slightly greater than the
breadth which is about I inch. Cardinal and umbonal regions
narrow. Hinge line scarcely equalling half the greatest width of
the shell. Pedicle valve depressed convex, bearing a broad sinus
anteriorly ; cardinal area of moderate height. Brachial valve very
gibbous with a greatly incurved umbo. About ten fine, bifurcat-
ing, radiating striz may be counted in the space of 54, inch.

New York, Iowa, Nevada, Northwest Territory.

211. S. tioga Hall. (Fig. 321, g—z.) Devonic.
Differs from S. s¢vzaézla in its smaller size, usually more pro-
nounced elevation of the pedicle valve and in the angular, fascicu-
late striz. ;
Portage and Chemung of New York, Ohio.
212. S. swallovi Hall. (Fig. 323.) Mississippic.
Large. Hinge line less than the width of the shell below.
Pedicle valve depressed convex near the beak and flat at sides with
a broad depression extending from the middle to the front.

Brachial valve gibbous. Surface covered with fine and close 7

radiating striz and sharp concentric growth lines.
Burlington of Illinois, lowa and Missouri.

Se Se ee Se Ole | ee

BRACHIOPODA—ORTHIDEZ. 269

FIG. 323. Schizophoria swallovi, K 2%. (After Hall.)

213. S. resupinoides (Cox). Carbonic.
Transversely ovate to subquadrate. Hinge line forming about

half the greatest width of the shell. Cardinal areas narrow, that

of the brachial valve being the higher.

Kentucky, Arkansas, New Mexico.

LVIII. ENTELETES Fischer de Waldheim.

Subglobular, plicate ; brachial valve the more convex. Hinge
line short. Cardinal area of pedicle valve high; that of brachial
valve low, at times linear. Cardinal process small, erect and
multi-lobate. Between the much extended and parallel dental

Fic. 324. a-—d,' Enteletes hemiplicata (Ind. Surv.); e-g, Clitambonites diversus,
ventral and dorsal views and interior of brachial valve (enlarged) ; 4-£, Scenidium
anthonense, ventral, dorsal and cardinal views and interior of brachial valve( Minn.

Surv. ).

lamellz is a blade-like median septum extending from beneath the
beak and enlarging to the middle of the valve where it suddenly
terminates. Crural plates of brachial valve support long, curved

270 NORTH AMERICAN INDEX FOSSILS.

crura. Entire surface of shell, including the few more or less
strong plications, covered with fine radiating striz. Upper Car-
bonic.
214. E. hemiplicata Hall. (Fig. 324, a—d.) Upper Carbonic.
Surface covered with fine and crowded radiating striz and a few
large and subangular radial plications which are distinct anteriorly
and die out towards the umbo. They are crossed near the front
by a few concentric lines of growth.
Missouri, Illinois, lowa, Nebraska, Colorado.

LIX. CLITAMBONITES Pander.

Semicircular. Hinge line straight, forming greatest diameter of
shell. Pedicle valve convex or subpyramidal; cardinal area high
and usually vertical with a broad convex deltidium perforate at
apex ; on the interior the dental plates unite to form a spondylium
which is supported on a median septum. Brachial valve depressed
convex or flattened. Upper Cambric—Ordovicic.

215. C. diversus (Shaler). (Fig. 324, e-g.) Ordovicic.

Subquadrangular. Umbo of pedicle valve always laterally in-
clined toward either extremity of the hinge line. - Surface marked
by numerous prominent strize crossed by delicate crowded growth
jines.

Trenton—Lorraine of Wisconsin, Minnesota, Ontario, Manitoba,

Anticosti.
LX. Scenipium Hall.

Small. Hinge line straight, usually equalling the greatest
width of the shell; delthyrium in each valve. Pedicle valve sub-
pyramidal with a high and usually erect cardinal area. Brachial
valve depressed, convex to concave, with low cardinal area. The
small cardinal process extends forward as a median septum through
the length of the valve and is at times so developed anteriorly as to
reach into the pedicle valve.. Ordovicic-Devonic.

216. S. anthonense Sardeson. (Fig. 324, 4-2.) Ordovicic.

Small with extended hinge line and conspicuous mesial sinus
and fold. Surface radiately striated.

Trenton of Tennessee, Illinois, Minnesota.

LXI. SynrropuHiaA Hall and Clarke.

Transversely elongate, biconvex. Hinge line nearly equalling
the greatest width of shell. Cardinal area long and straight; an
open delthyrium on each valve. Spondylium deep and:short, its
anterior half unsupported. Upper Cambric—Ordovicic.

BRACHIOPODA—PROTREMATA. 27%

217. S. calcifera (Billings). (Fig. 325.) Upper Cambric.
Brachial valve triangular posteriorly. Moderate sinus in pedicle
valve and fold on brachial. Surface marked by concentric growth
Jines only. Average length about 36 inch.
Saratogan, etc., of Mis-
souri, Utah, Nevada, Quebec,
Newfoundland.

LXII. Camaretra Billings.

Small, smooth in the um- Fic, 325. Syntrophia calcifera, pedicle and
bonal region with a few low brachial valves. (After Walcott. )

plications anteriorly ; no car-

dinal areas. Pedicle valve with erect beak and an open delthy-
rium. Well-defined spondylium present. Brachial valve at ma-
turity the more convex. Median sinus on pedicle valve and fold
on brachial. Ordovicic—Siluric.

218. C. varians Billings. (Fig. 326.) Ordovicic.
Subtriangular. Valves mod-
erately and equally convex.
Anterior angles rounded. Pili-
cations rounded, 6-8, of which
Fic. 326. Camarells varians (Canadian 2-4 occupy the mesial sinus and
Surv.). 3-5 the fold. Length about %
inch, width about the same.

Beekmantown-—Chazy of New York, Newfoundland, Mingan
Islands.

LXIII. Parastropuia Hall and Clarke.

Subcircular. Hinge line moderately long and straight. No
cardinal areas. Brachial valve the larger and more convex, its
beak projecting conspicuously beyond that of the pedicle valve.
Otherwise much like Camarella. Ordovicic—Siluric. :

219. P. hemiplicata Hall. (Fig. 327.) Ordovicic,

Subglobose, wider than long, with thickness often equal to length.
Hinge line short. Pedicle valve depressed convex with an abrupt
broad sinus. Brachial valve very convex with a broad median
fold. Surface marked by about 6-8 plications, strong toward the
front but fading away entirely toward the umbo. 2-3 plications
occupy the sinus and 3-4 the fold; all are crossed by concentric
lines.

272 NORTH AMERICAN INDEX FOSSILS.

: ; 7
Trenton of New York, Pennsylvania, Wisconsin, Minnesota,
Ontario, Manitoba.

LXIV. ANASTROPHIA Hall.

Differs externally from Parastrophia in having a more prominent
umbo in the brachial valve and in that the valves are covered with
many sharp plications extending to the beaks. Siluric-Devonic.

Fic, 327. Parastrophia hemiplicata ( Cana- Fic.. 328. <Anastrophia interplicata

dian Geol. Surv. ). (N. Y. State Surv. ).
220. A. interplicata Hall. (Fig. 328.) Siluric.

Subovate. Brachial valve much more convex than the pedicle.
Beaks very short and closely incurved. Plications three or four on
each side of the beak near the cardinal margins; an additional one
is inserted between each pair, except the central ones, about half
way toward the front.

Niagaran of New York, Kentucky and Wisconsin.

221. A. internascens Hall. (Fig. 329.) Siluric.
Ovoid or subglobose with brachial valve slightly the more
gibbous. Pedicle valve with depressed anterior portion marked by

Fic, 329. <Anastrophia internascens. Fic. 330. Anastrophia verneuth (Cana-
(After Hall. ) dian Geol. Surv. ).

a broad, undefined sinus and short beak closely incurved over
umbo of opposite valve. Brachial valve elevated in center, some-
times forming a broad undefined fold.

Niagaran of Kentucky, Indiana, Wisconsin. e

eS ee ee eae ee

eee

|
:

BRACHIOPODA—PROTREMATA. 273

-222. A. verneuili (Hall). (Fig. 330.) Devonic.

Globose with width generally exceeding length. Pedicle valve
with distinct sinus. Brachial valve very elevated with exceedingly
gibbous beak, strongly incurved and covering the foramen of the
opposite valve. | |

Helderbergian of New York, Tennessee, Greenland.

LXV. Concuipium Linnzus.

Elongate subpentagonal, strongly inequivalved, biconvex, with-
out well defined median sinus and fold. Pedicle valve highly
arched; delthyrium very broad. Spondylium narrow and deep,

Uf
YY, YA

Z
y

MN i

(
iM
NW

mn

Fic. 331. Conchidium occidentale (Canadian Geol. Surv. ).

supported by a higu septum. Beak of brachial valve closely in-
curved; cardinal process small; a pair of median septa in pos-
terior portion of valve. Surface with numerous radiating plica-

tions. Siluric-Devonic.

223. C. occidentale Hall. (Fig. 331.) Siluric.
Ovoid. Plications scarcely equalin width to the spaces between
them.
Guelph of Wisconsin, Ontario.

224. C. nettelrothi Hall & Clarke. (C. kuighti Nettelroth.)
(Pig, 332.) Siluric.
Differs from the preceding in its proportionately greater con-

vexity of valves, narrower form, higher pedicle valve, with strongly

incurved umbo and pronounced flattenings on either side of the
delthyrium, and in the coarser close and sparse plications which
extend to the beaks.

274 NORTH:AMERICAN INDEX FOSSILS.

Niagaran? of Falls of Ohio Region. Upper Siluric of Nova
Scotia.

225. C. laqueatum Conrad. Siluric.
Large, trigonal or trapezoidal and very ventricose; pedicle
valve twice as long as deep, with scarcely incurved but projecting
beak; brachial valve shallower. Pli-
cations rounded to subangular,more
widely spaced towards lateral mar-
gins where they disappear.
Niagaran of Indiana, common.

LXVI. STRICKLANDINIA Billings.

Usually large. Valves nearly
equal. Pedicle valve with a short
median septum in the interior sup-
porting a small and short spondy-
lium. Hinge line straight, cardinal
area present on each valve and beak
of pedicle valve not highly arched; .
otherwise very similar to Conch-
wdtum., Siluric.

Fic. 332. Conchidium nettelrotht.
(After Nettelroth. )

226. S. davidsoni Billings. Siluric.
Longitudinally ovate, ? inch—3 inches long with width about 4
less. Front of shell narrowed to a linguiform extension. Beaks

FIG. 333. Stricklandinia castellana. (After Hall and Clarke. )

only slightly developed. Pedicle valve often with a faint median
sinus in youth, becoming obsolete with age, often developing into

afold. Brachial valve with a fold widening into the linguiform ox

BRACHIOPODA—PROTREMATA. 275

tension. Surface covered with faint radiating ribs, 3-5 occupying
the width of } inch at the margin.

Anticosti group of Georgia, and of Anticosti and eastern
Canada.

227. S. castellana White. (Fig. 333.) Siluric.
Valves nearly equiconvex, subcircular ; surface of each valve with
strong, irregularly fasciculate or duplicate plications.
-Niagaran of Iowa.

LXVII. PenTamerus Sowerby.

Strongly inequivalved, biconvex with highly arched pedicle
valve. Like Conchidium, but with surface smooth or with but a
few broad, obscure, radiating undulations. Siluric.

228. P. oblongus Sowerby. (Fig. 334.) Siluric.
_ Very large, varying in outline with age. Wider anteriorly.
Valves strongly convex at beaks. Surface marked only by con-
centric lines of growth which are strongest in old shells. The pair

Fic. 334. Pentamerus oblongus, dorsal and internal views (Pal. N. Y.).

of septa in the brachial valve are near together and subparallel.
Clinton and Niagaran of New York, Kentucky, Ohio, Indiana,
Illinois, Iowa, Wisconsin, Ontario, Anticosti.

_ 228a. P. oblongus var. subrectus Hall. Siluric.
_ Elongate subquadrate; with high, subrectangular cardinal ex-
_ tremities. Each valve witi impressed longitudinal median and

276 NORTH AMERICAN INDEX FOSSILS.

two divergent grooves,which divide again. Sometimes indications
of a few coarse plications present.
Niagaran beds of Iowa.

2284. P. oblongus var. cylindricus Hall & Whitfield. Siluric.
Elongate, subcircular in cross-section. Valves more or less dis-
tinctly trilobed in anterior half, rounded or truncate in front, gen-
erally with shallow sinus in each valve in front. Beak of more
convex (pedicle) valve overarching.
Niagaran near Louisville, Kentucky, Wisconsin and Indiana.

LXVIII. Crorinpa Barrande.

Small, pentameroid. Median sinus in pedicle valve and fold in
brachia!. Surface smooth or rarely plicate. Spondylium without
a supporting septum. Siluric.

229. C. (Barrandella) fornicata (Hall).
(Fig. 335.) Siluric.
Pedicle valve very convex with over-

arching beak. Surface obscurely pli-

cate longitudinally. _Umbo of pedicle

valve much more gibbous than in C:

ventricosa.

Clinton and Niagara of New York, Indiana, Wisconsin.

Fic. 335. Clorinda fornicata
Pat. 2, ¥ 7.

230. C. (Barrandella) ventricosa (Hall). (Fig. 336, a—d).
Siluric.
Small, subglobose, usually wider than long. Both valves strongly
ventricose with incurved beaks, that of the pedicle valve being

Fic. 336. a-b, Clorinda ventricosa. (After Nettelroth.) ¢, Gypidula coms.
(After, Walcott. )

much the higher. Surface more or less marked by concentric
lines of growth.
Niagaran of Kentucky, Ohio, Illinois, Wisconsin.

= =

— ss er Ore eee

eo SS a =——=_ ©

:
j

BRACHIOPODA—PROTREMATA. 277

LXIX. PENTAMERELLA Hall.

Pentameroid, more or less rotund, with a sinus on pedicle valve
and fold on brachial. Much like Clovizda but larger and strongly
plicate, with a narrow cardinal area. Brachial valve with the crural
plates supporting septa conjoined so as to form a broadly sessile
spondylium. ? Siluric-Devonic.

231. P. arata (Conrad), (Fig. 337.) Devonic.
Ovate, with gibbous pedicle valve which in old age becomes very
arcuate with strongly incurved beak, Brachial valve only moder-

Fic. 337. entamerella arata, average sized, and extremely old age individuals

(Pal. N. Y.).

ately convex. Surface covered with angular plications, often
developed only below the first third of the length and usually
bifurcating.

Schoharie and Onondaga of New York, Ohio, Kentucky,
Indiana, Michigan, Ontario.

232. P. pavilionensis Hall. Devonic.
Differs from the preceding, in having the valves more nearly
equally convex, and fewer rounded plications which become
obsolete toward the beak and often on lateral slopes; and in having
a well defined fold and sinus with four and three (or two) plications
respectively.
Hamilton beds of New York, Falls of the Ohio, Michigan, ete,

278 NORTH AMERICAN INDEX: POSSILS.

LXX. Gypiputa Hall.

Pentameroid, ventricose. Pedicle valve much the larger, with
or without a mesial fold; cardinal area generally well defined, cross
striated ; spondylium unsupported for most of its length. Brachial
valve with or without mesial sinus; spondylium large, sessile, acute
anteriorly. Siluric-Devonic.

233. G. (Sieberella) galeata (Dalman). (Fig. 338.)
Siluric? and Devonic.
Subglobose. Pedicle valve gibbous with a mesial fold toward
the front and a strongly incurved beak. Brachial valve gibbous
above, with or without a mesial sinus near the margin. Surface in
youth smooth but developing longitudinal plications in older forms.

Fic, 338. Gypidula galeata (Pal. N. Y.).

Differs from G. coms in its greater gibbosity, in the absence of a
distinct cardinal area, in the greater prominence of the plications
and in the greater incurving of the beak of the brachial valve under
that of the pedicle valve, thus concealing the delthyrium.

Helderbergian (Coeymans) of New York, Pennsylvania, Mary-
land, New Brunswick, Northwest Territory. ? Niagaran of Indiana.
Middle Devonic of Europe.

234. G. (Sieberella) pseudogaleata (Hall). (Fig. 339.)
Lower Devonic.

Like G. gadeata but differs in the absence of radiating plications.
Becraft of New York, etc.

235. G. comis (Owen). (Fig. 336, c.) Middle Devonic.
Pedicle valve arcuate, with extended and strongly incurved beak ;

delthyrium large and bordered by a distinct area. Surface ele- .

i i i i ai ea i a hE,

BRACHIGPODA—PROTREMATA.

279

vated into a more or less distinct mesial fold. Brachial valve de-

pressed anteriorly into a sinus.
‘few rounded plications which

become obsolete above, leav-
ing the upper part of the valve
marked only by concentric
striz.
Illinois,
Manitoba.

Iowa, Nevada,

236. G. romingeri Hall and
Clarke. (Fig. 340.)

_ Devonic.

Large. Pedicle valve very

convex; brachial valve de-

pressed convex.

Surface usually bearing below a

FIG. 339.

Gypidula pseudogaleata (Pal.
N.Y.)

Surface covered with strong plications which

frequently bifurcate irregularly toward the front.

FIG. 340.
ternal view and interior of brachial
valve. (After Hall and Clarke. )

‘ York, Michigan, Ontario, etc.

Cypidula romingeri, ex- —

Hamilton of Michigan.

LXXI. AMPHIGENIA Hall.

Elongate-ovate, high-shouldered,
without median fold or sinus. Pedi-
cle valve with a spondylium, bra-
chial valve with a large hinge plate
perforated at the apex by a fora-
men. Surface marked by concen-
tric growth lines and faint radial
strize. Devonic.

237. A. elongata (Vanuxem).
(Fig. 341.)
More or less gibbous, with

broadly rounded front. Pedicle

valve the more convex; beak
closely incurved over the umbo of
opposite valve. Both valves often
abruptly elevated above the middle.

Shell structure punctate.

Oriskany and Onondaga of New

Devonic.

280 NORTH AMERICAN INDEX FOSSILS:

FIG. 341. Amphigenia elongata (Pal. N. Y., IV.).

LXXII. CamMaropuoria King.
Rhynchonelliform. Surface more or less plicated. Spondylium

Fic. 342. a-c, Camarophoria sub-
cuneata. (AfterWhitfield.) d-e, Ortho-
rhynchula linneyi. (After Nettelroth. )

St. Louis of Ohio, Indiana.

supported by a long median septum.
Devonic—Carbonic.

238. C. subcuneata Hall. (Fig.
342, a-c.) Mississippic.
Wedge-shaped with rounded

front, nearly equally biconvex.

Beak of pedicle valve very acute

and but little incurved, perforated

by a triangular foramen. Surface
marked by 12-14 angular plications,
crossed by concentric striz.

a eS ee ee ee

—_- = =

|
q
;

BRACHIOPODA—TELOTREMATA. 281

TELOTREMATA.
LXXIII. ORTHORHYNCHULA Hall and Clarke.

Rostrate, with narrowed beaks. Hinge-line straight, extending
about one third the transverse diameter of the valves. Cardinal
area present on both valves, that of the pedicle valve being the
higher; delthyrium open. No dental lamelle in the pedicle valve.
Cardinal process linear. Surface strongly plicate. It thus re-
sembles both Ortiis and Rhynchonella. Ordovicic.

239. O. linneyi (James). (Fig. 342, d, ¢.) Ordovicic.
Median fold and sinus well developed. Average length 4 inch,
width & inch, thickness + inch.
Lorraine of Kentucky, Tennessee, Ohio.

LXXIV. RHYNCHOTREMA Hall.

Rostrate, thick-shelled. Pedicle valve. with apex closely in-
curved over that of brachial. Teeth strong. Deltidial plates
concave, thick, cemented firmly to the bottom of the valve.

' Brachial valve with a thickened median septum. Cardinal pro-

cess slender, linear, with broad and stout crural plate on each side.
Ordovicic and Devonic.

240. R. inequivalve (Castelnau). (Fig. 343, ad.) | Ordovicic.

Small. Pedicle valve strongly convex at umbo and nearly flat
on each side of the deep median sinus, sloping laterally. Brachial
valve more convex than the pedicle. Surface marked with prom-
inent subangular plications, 15-22 on each valve with 3-5 on the
fold and 2-5 in the sinus, crossed by very delicate concentric zig-
zag lines.

Trenton. Widely distributed throughout North America.

241. R. dentatum Hall. (Fig. 343, e-g.) Ordovicic.

Pyramidal with breadth somewhat greater than length. Beak
of pedicle valve small and acute, closely incurved over that of the
brachial valve. Pedicle valve with a broad, deep and angular sinus,
strongly elevated toward the front. Surface marked by 8 org
strong and deep plications, two of which are very much elvated on
the fold of the brachial valve and one of which occupies the sinus

_ of the pedicle valve.

Trenton and Lorraine of New York, Tennessee, Ohio, Indiana.

282 WORTH (AMERICAN INDEX “FOSSILS.

242. R. capax (Conrad). (Fig. 343, 4-4.) Ordovicic.

Beak of pedicle valve closely incurved over that of brachial,
Apex of pedicle valve usually perforated by a small pedic'e open-
ing. Three (rarely 4) angular plications occupy the very promi.

Fic. 343. a@-d, Rhynchotrema inequivalve (Min. Survey); eg, Rhynchotrema
dentatum (Ind. Survey); 2-2, Rhynchotrema cafax (Ind. Survey); /-m, Rhyncho-
trema_ainsiit (Min. Survey).

nent sinus and 4 the corresponding fold on the brachial valve.
The angular radiating plications are crossed by many strongly zig-
zag growth lines. i
Lorraine ; widely distributed throughout North America.
243. R. ainslii N. H. Winchell. (Fig. 343, 4.) . Ordovicic.
Differs from A. zxeguivalve in being usually larger, more trans-
verse, and in having 28 to 34 plications with 6 to 8 on the fold.
Trenton of lowa and Minnesota.

LXXV. RHYNCHOTRETA Hall.

Elongate triangular, marked with angular plications. Beak of
pedicle valve acuminate and produced beyond that of opposite ~

BRACHIOPODA—TELOTREMATA. 283

valve. Pedicle valve at first with a median fold which later be-
comes a sinus; the brachial valve likewise reverses its early me-
dian sinus into a fold. Two elevated and longitudinally striated
deltidial plates fill the delthyrium. Siluric.

244. R. cuneata americana Hall. (Fig. 344.) Siluric.
_ Wedge-shaped. Beak of pedicle valve angular with compressed
sides. Deep frontal emargination extends as a broad sinus two
thirds of the distance to the beak.
Plications crossed by threadlike concen-
tric striz.

-Niagaran of New York, Kentucky,
Indiana, Wisconsin, Ontario.

Pie VI. CamAROTa@cHIA Hall and

Clarke. |
Rhynchonelloid, rostrate. Brachial :
valve the deeper. Pedicle valve shal- F'S. 344. Ahynchotreta cu-

neata var. americana ( Pal. N.

low with beak projecting over that of the Y., I.)

brachial. Surface radially plicate. Dis-
tinctive internal characters are: a median septum in the brachial
valve, dividing posteriorly to form an elongate spondylium, no car-
dinal process. In the pedicle valve slender vertical lamellze sup-
port the teeth. Ordovicic—Mississippic.

A, Small —less than ¥% inch wide....... Pi pcennvoa Makivnante auidts emp yet oen enh iets sardag sep im
CERTAIN WUGLISICATIY EQUAL... o.. csecgens vinetnw sous bacasteseaisesgaens ouneiteincuhes ent a
MN PORE EIN 5 iv Serge as nelecpamecbentoiin cvs wodab¥secasveasas 254. C. dotis.

EE TENTMIOUTY: ob ac cicel sorte, cst xe ade ace ts sonata lays Vive buys da wabertdnvwsies ade a.

a. Fold and sinus very conspicuouS...........0600s000eeees 246. C. neglecta.

a. Fold and sinus inconspicuous.............seeeseeeees 252. C. semiplicata.
I RCECQUE WIC a cece nda ses nnianveetacshceaesicerenacae: over. 247. C. acinus.
maeaach exceeding length., Surface rugose. ..............0ss0008- 250. C. damellata.

Beemer tum Size — 34 INCh OF MOTE WIE ......562.sercerecesacs senecavecinees cueceeees =)

meepransversely Oval, z. ¢., width exceeding length.............2.cecceetecec: scessenns re
2. Plications angular, numerous (20-24), of which 4-7 mark the mesial sinus
MMOUG ralea as Pears: diisxgnt i Atinanbatawaien ae lasesaihersedavaadasasis de deness b.

Bx TAMCAUOUS COATSE ANA PTOMINENE . 0s. sce cennescugecncences 256. C. sappho.

ie VigeiMemte IIE <3 05 Spe Losjweiek, Baa ast vehendatcba vig hos 255. C. horsfordi.

2. Plications obtuse, few (about 16), of which 2 or 3 mark the sinus and
Ee A nah eR eres aiid Gast Mah wp ab oa dabaddedabnigsig seth 258. C. sageriana.

** Somewhat quadrangular, 7. ¢., with length and breadth nearly equal ......... ef
Metre VAIVES, MDEICEADIY CONVO 51) i.cice ie cer nct care custencecsevivincascnces castes c.

don, ENICAUOMS PUR STOUS: (LA 20) 65.04 05 wp oilas cede sain dons? deowan tas ode<aedes i.

1’. Shell ventricose, thickness equal to or greater than length,
272. C. (Wilsonia) ventricosa.

284 NORTH AMERICAN INDEX. FOSSILS:

SS SoU Rit METRE CORE 2524 Lyn tint te ni cds andeakewannacban custea Gaeee al,
a’. Pedicle valve with small, closely incurved beak.
245. C. plena.
a’. Pedicle valve with large, not closely incurved beak.
251. C. litchfieldensis.
eo Up Nicatioms fey YOGA) us ccsikaninoseend yes apacnph. ined ccvaensiemeeeeenee 2
2’. Angle at beak between cardinal slopes less than go°.
248. C. indtanensis.

2', ,AMpie at beak ereater ThaniG@°. .....casscexoessaees 249. C. whiter.

Sock CONCISE VAIVE THRMCRON ooh Riss edu xackas case cmahetoesnidcbu tere eee da.

d. Sinus-and fold with 2—4 plications.................00. 257. C. contracta.

ad. Sinus and fold with 5 or 6 plications ...............sc0008 253. C. tethys.

245. C. plena Hall. (Fig. 345.) Ordovicic.

Gibbous. Pedicle valve
with small beak closely in-
curved over that of the bra-
chial valve. Surface of each
valve marked with 16-20
strong radial plications,
about 4 or 5 of which oc-
cupy the sinus and fold.
Chazy of New York, Ontario, Quebec.

Fic. 345. Camarotechia plena (Canadian
Geol. Surv. ).

240. C. neglecta Hall. (Fig. 346.) Siluric.

Small. Brachial valve the more convex. Sides sloping ab-

ruptly from beak. Plications 8-13. Strongly defined sinus and

fold, the former with 3, the latter with

4 plications. Deep frontal emargination a 6»

present.

Clinton and Niagaran of New York,

Ohio, Indiana, Wisconsin, Ontario,

Nova Scotia.

247. C. acinus Hall. (Figs. 347, 348, EE» dip
yam row.) . Seni. Fic. 346. Camarotechia neg-
Small, longitudinally ovate, narrowed ,,,, (Pal, Ni V. 1m

toward the beak and truncate in front.

Valves of nearly equal convexity. Surface marked by few plica-

tions of which there is one in the very low sinus of the pedicle

valve and two in the inconspicuous fold of the brachial.
Clinton of New York, Niagara of Indiana, Kentucky.

248. C. indianensis (Hall). (Fig. 348, middle row.) Siluric.

Subtriangular, moderately biconvex. Length and width nearly ~

ee eee

7

a

=
SS —se Oe ee

= a —

ee

BRACHIOPODA—TELOTREMATA. 285

equal (about % inch). Pedicle valve with pointed and incurved
beak. Surface marked by 9-12 strong plications of which 2-3
occupy the sinus and 3-4 the fold. Differs from C. weglecta in

Fic. 347. Camarotechia acinus. A specimen in which the fold and sinus are not
developed. Enlarged, 4. Clinton. (After Grabau. )

being larger and more robust with stronger and less angular pli-
cations.
Niagaran of Kentucky, Indiana.

249. C. whitei Hall. (Fig. 348, lower row.) Siluric.

Somewhat quadrangular. Pedicle valve with beak abruptly at-
tenuate and pointed; sides flattened. Surface marked with five to

Fic. 348.", (Upper row) Camarotechia acinus, X 4: (middle row) Camarotechia
indianensis ;*(lower row) Camarotechia whitet. (After Hall.)

six plications on each side of median sinus and fold, with usually
but one plication in the sinus and two on the fold. Interspaces
wider-than plications. Concentric growth lines close.

Niagaran of Indiana.

286 NORTH AMERICAN INDEX-FOSSILS.

250. C. lamellata Hall. (Fig. 349.) Siluric.
Small, subrhomboidal. Surface with six to seven simple plica-
tions on each side of fold and sinus; usually but two plications in
sinus and three on fold. Entire shell crossed
by strong, imbricating, concentric lamelle
which are conspicuously arched over the pli-
cations, giving the surface a rugose appear-
ance.
Rica. | Cuneo Upper Siluric (Cobleskill, etc.) of New

chia lamellata (Pal. N. York, New Jersey, Pennsylvania, Maryland
Ya).

and West Virginia.

251. C. litchfieldensis Schuchert. (Fig. 350.) Siluric.

Large, robust. Length and breadth subequal. Umbo of ped-
icle valve large and prominent. Surface with 16 to 18 plications,

Fic. 350. Camarotechia litchfieldensis, (After Schuchert. )

of which three and four occupy respectively the rather narrow and
unpronounced sinus and fold. |
Cobleskill and Rondout of New York.

252. C. semiplicata (Conrad). (Fig. 351.) Devonic.

Subtriangular. Valves nearly equal. Surface smooth in upper
portion with low plications toward the front, one to two of which
occupy the shallow sinus and two to three
the low fold; a few (one to four) are present
on each side of fold and sinus. Very similar
to C. acinus, but the angle at the beak be-
tween the cardinal slopes is larger, the sinus
and fold are more pronounced and the li
shell is larger, averaging about ,§ inch in _ IS. 35% -eaaseaaaee
length, while C. acizus averages only about hia sa
3; inch.

Helderbergian (Coeymans) of New York.

|
i

eS ee es SDC CO eee eee

255. C. horsfordi Hall. (Fig. 354, a, 3d.)

BRACHIOPODA—TELOTREMATA. 287

253. C. tethys (Billings). (Fig. 352, a-c.) Devonic.
Differs from C. contracta in its subtrigonal form and broader sinus
and fold which here bear 5 or 6 plications each.

8

Fic. 352. a-c, Camarotachia tethys. (After Nettelroth.) d@-g, Camarotechia
contracta (Pal. N. Y. IV.). 2, Letorhynchus sinuatum. (After Walcott. )

Onondaga of New York, Ohio, Kentucky, Indiana, Nevada,
Ontario. |

254. C. dotis Hall. (Fig. 353.) Devonic.
Subtriangularly ovate with shallow sinus and moderate fold.
Pedicle valve slightly flattened at the sides. Plications about 18
in number of which there are 3 or 4 in the
sinus and 4 or 5 on the fold.
Marcellus and Hamilton of New York,
Ohio.

FIG. 353. Camarote-

Devonic. chia dotis. (Grabau.)

Length to width as § to 6 or 7.
Brachial valve very convex. Pe-
dicle valve depressed-convex
with sinus appearing first at
about the middle of the shell,
abruptly curved upward in front.
15-24 angular plications on each
valve, of which 4-7 mark the
: * < sinus and fold.
am a Marcellus and Hamilton of

Fic. 354. a-b, Camarotachia horsfordi ; New York, Nevada.
c-d, Camarotechia sappho (Pal. N.Y.IV.).

288 NORTH AMERICAN INDEX. FOSSILS,

256. C. sappho Hall. (Fig. 354, c, a.) Devonic—Mississippic.
Large and robust, broader than long. Pedicle valve depressed-
convex with abruptly acute apex. Brachial valve gibbous, regu-
larly arching transversely. Surface marked with 20-24 strong,
angular plications.
Marcellus- Waverly of New York, Ohio.
257. C. contracta Hall. (Fig. 352, dg.) Devonic—Mississippic.
Subquadrate, abruptly and deeply sinuate. Pedicle valve very
slightly convex, often becoming almost flat near the front and
marked by a broad angular sinus. Brachial valve somewhat
gibbous in the middle and regularly convex transversely, marked
by a mesial fold. Surface with 16-20 angular plications of which
there are 4 on fold and 3 in sinus.
Portage-Waverly of New York, Pennsylvania, Ohio.

258. C. sageriana (A. Winchell). Mississippic.
Of medium size. Brachial valve quite convex with a prominent
and inflected beak and about 16 obtuse radial plications, some of
the central ones showing a groove on the summit toward the front.
Mesial fold developed only at front of valve where it consists of 2
or 3 slightly elevated plications.
Marshall of Michigan, Waverly of Tennessee, Ohio.

LXXVII. STENOCHISMA.

Differs from Camarotechia
in wanting the median septum
of the brachial valve with its
subcardinal cavity; and in
having the hinge plate divided
by a median fissure which ex-
tends to the bottom of the
shell and contains a slender
cardinal process. Devonic.

259. S. formosum (Hall).
(Fig. 355.) Devonic.

Fic. 355. Stenochisma formosum (Pal. N. J ‘
Y. I11.). : Subtriangular, the lateral

margins forming an angle at
the beak of 90° to 110°. Beak of pedicle valve prominent and
arched. Brachial valve the more convex. Surface marked with
20 to 24 simple, angular plications on each valve, 2 to 4 of which
occupy sinus and fold.

BRACHIOPODA—TELOTREMATA. 289

Helderbergian of New York, New Brunswick and Nova Scotia.
LXXVIII. Leioryyncuus Hall.

Similar to Camarotwchiia but with the plications on the median
fold and sinus highly developed while those on the lateral slopes
are slightly developed or wanting. Shell substance thin. Dev.—Miss.

260. L. mysia Hall. (Fig. 356.) Devonic.
Very small, usually not exceeding 3 inch in diameter, with
almost circular outline and with proportionally very strong plica-
tions of which there is at least
one in the sinus with at least
three on each side of it.
Marcellus of New York.

261. L. limitare (Vanuxem).
(Fig. 357, 2-0.) Devonic.
Small, gibbous, with mesial si- 3

nus and fold developed toward Fic. 356. Letorhjnchus mysia (Pal.

the front. Plicationsonfold and w_y. Iv.).

sinus bifurcating. Surface plica-

. tions covered with fine concentric striz.

Marcellus of New York, Ohio.

262. L. laura (Billings). (Fig. 357, c.) Devonic.
Length and greatest width nearly equal. Sinusand fold marked
with 3 to 7 rounded plications, all bifurcating. Concentric strie
present.
Marcellus-Hamilton of New York, Nevada, Ontario.

FIG. 357. a—, Letorhynchus limitare,; c, L. laura, dad, L. quadricostatum.,

__ 263. L. quadricostatum (Vanuxem). (Fig. 357, @.) | Devonic.

Broadly ovate. Plications of lateral slopes very faint. Sinus
and fold marked with 3 to 5 rounded plications. |
Genesee of New York, Indiana, Kentucky, Nevada.

290 NORTH AMERICAN INDEX FOSSILS.

264. L. sinuatum Hall. (Fig. 352, 7.) Devonic.
Differs from ZL. “imitare in its larger size and more robust
development and in its coarser plications which do not extend to
the beak.
Chemung of New York, Nevada.

LXXIX. Uncinutus Bayle.

Subcuboidal with an abrupt anterior slope. Fold and sinus
sharply developed only at anterior margin. Plications low, marked
anteriorly by a faint median line. Muscular scars of pedicle valve
very large and deep. Hinge plate of brachial valve undivided.
Cardinal process well developed, bifid or simple. Median septum
well developed. Siluric—Devonic.

A... Plieations numerous, about 25-10) 36-2. s...cccvoes ced cde eciicve sxe O09 cope Puen x
* Median fold, rather promiment ......000c cnccssesse vee de voceise ou cpesdce gynes Seen eae i

1. sides and front: abruptly deflected 2.4... 005.004.6200 \exe o« v'nssays = se oe a.

@, Sim0S, COMparatively MALTOW..cons00. ccs-c.e on eeetees ate 270. U. vellicatus.

@,, Sinus Jeomparatively broadv-tx iron. c ok he ee 269. U. abruptus.

1. Sides and front rounded, not abruptly deflected......... 265. U. stricklandt.

* Median’ fold younded, not promiment 4:5. Bisyicwsi. tne eoreeew onesies 271. U. nobrlis.

4B. Elications few, about P5:10 25 ves cceiosvisisons. acct sejoes voiessat cence ee pyle nen RB
* * Pedicle valve depressed: COMVER «206.0. sinnss enon svteve onbecnncsio nda sues seen 2

2. Brachial valve declining regularly from fiont to beak...267. U. uucleolatus

2. Brachial valve declining more abruptly near the beak.
266. U. campbellanus.
PTAA RIVES COVEN «00 Un Woes Panag here hoot so sie ae Sn, ae pes se aR 268. U. mutadbilis,

265. U. stricklandi (Sowerby). (Fig. 358.) Siluric..
Large (about I inch long), ovate very convex. Length and
breadth about equal. Sides and front rounded. Pedicle valve de-

Fic. 358. Uncinulus stricklandi. (After Hall.)

pressed-convex ; beak small, closely incurved over that of the
opposite valve; mesial sinus wide, deep in front. Brachial valve
gibbous; mesial fold wide, prominent anteriorly. Surface marked,

BRACHIOPODA—TELOTREMATA. 291

by 25-35 simple angular plications of which 6-8 occupy fold and
sinus.
Niagaran of Kentucky, Indiana.

266. U. campbellanus (Hall). (Fig. 359.) Devonic.
Laterally compressed. Width 2 length. Brachial valve the
larger, elevated near front into a broad undefined mesial fold,

curving abruptly at sides. Pedicle valve with a broad shallow

sinus towards the front; lateral margins of valve abruptly deflected

toward opposite valve, thus giving the sides of the shell a flat-

tened appearance. Surface marked by 20-26 simple plications.
Helderbergian (Becraft) of New York.

267. U. nucleolatus Hall. (Fig. 360.) Devonic.

Subspherical, declining towards the beak. Pedicle valve de-
pressed convex, abruptly deflected towards margins; brachial
valve very convex anteriorly, depressed posteriorly. Surface

Fic. 360. Uncinulus nucleolatus (Pai. N. Y., III.).

marked by 15-23 simple plications about 4 or 5 of which, by
their slight elevation on the brachial valve and their depression on
the pedicle valve form a more or less distinct fold and sinus.
Helderbergian (New Scotland) of Maine, New York, New Bruns-
wick,
268. U. mutabilis Hall. (Fig. 361.) _Devonic.
Ovate to spherical. Beak of pedicle valve small, pointed and
closely incurved over the opposite valve. Beak of brachial valve
incurved beyond the hinge line. Cardinal border on each side of

292 NORTH AMERICAN INDEX FOSSILS.

the beak concave. Surface bearing numerous (20-26) low, rounded,
simple plications of which six and five (sometimes 8 and 7) occupy
respectively the fold and sinus.

Helderbergian (Coeymans) of New York.

Fic. 361. Uncinulus mutabilis (Pal. NY; Bay

269. U. abruptus Hall. (Fig. 362.) Devonic.

Transversely oval. Pedicle valve depressed-convex and very
abruptly deflected (almost at a right angle) toward the opposite
valve on the lateral and anterior margins; beak small, closely in-
curved. Brachial valve very prominent in front; beak depressed.

Fic. 362. Uncinulus abruptus (Pal. N. Y., III.).

Surface with 25 to 33 simple, subangular plications; the low but
distinct fold and sinus occupied by about 7 and 6 respectively.

Helderbergian (New Scotland) of New York. -

~s ee ee

eile

BRACHIOPODA—TELOTREMATA. 293

270. U. vellicatus Hall. (Fig. 363.) Devonic.

Pedicle valve depressed-convex. Brachial valve gibbous in
front, depressed and rounded toward the beak. Surface with 24
to 36 plications of which 6 to 8
occupy fold and 5 to 7 the sinus.
Differs from U. adruptus in its
smaller size, its smaller and more
numerous plications; aiso in being
less ventricose, due to its narrower
and more pronounced median si-
nus and fold and its posteriorly less
convex brachial valve. BA Pie ee A eA

Helderbergian (New Scotland) of y y., Bch Sota SaaS
New York and New Brunswick.

271. U. nobilis Hall. (Fig. 364.) Devonic.
Pedicle valve depressed-convex; brachial valve declining later-
ally with an abrupt curve to meet the inflected margin of the ped-
icle valve ; its umbo rather
prominent and_ incurved.
Surface marked with 26 to
32 strong, angular plica-

* tions, six to eight of which
occupy the rounded mesial
fold and 5 to 7 the rounded
Fic. 364. Uncinulus nobilis (Pal. N. Y.,1II.). sinus. This species is more
elongate than U. adruptus

and less than U. campbellanus.

Helderbergian (Becraft) of New York and Pennsylvania.
LXXX. Witsonia Kayser.

Hingeplate small, divided by a shallow median incision; no car-
dinal process; otherwise like Uncinulus, from which it is indistin-
guishable by external characters. Siluric to Devonic.

272. W. ventricosa (Hall). (Fig. 365.) Devonic.

Spheroidal, ventricose. Cardinal region on each side of the beak
elevated. Beak of pedicle valve rather small and obtuse, closely in-
curved. Surface with 14 to 20 low, rounded plications. Very in-
conspicuous sinus and fold at times present, occupied by two to
four plications. Front of plications marked by a longitudinal

204 NORTH AMERICAN INDEX .POSSILS.

depressed line. Differs from Uncinulus nucteolatus externally in
having stronger plications.
Helderbergian (Becraft) of New York.

Fic. 365. Wilsonta ventricosa (Pal. N. Y., III.).

LXXXI. Hypotuyris King.

Subcuboidal, with plications. Similar to Uncznulus but muscu-
lar scars of pedicle valve are small and faint and the septum in
brachial valve is very faint. Devonic.

273. H. emmonsi (Hall and Whitfield). Middle Devonic.

Squarely truncate in front. Pedicle valve depressed-convex ;
beak small, projecting; median sinus very broad, at front abruptly
bent upward in a broad linguiform extension nearly equal to the
entire height of the shell and about two thirds as wide as the width
of the shell; the sides of this extension are straight and parallel

Fic. 366. a-d, Hypothyris cuboides (Pal. N. Y.,1V.); e{ Pugnax pugnus (Pal.
N. Y, IV.) ; g-h, Pugnax grosvenori (Ind, Geol. Survey).

almost to the top. Brachial valve very convex. Surface marked
by about 25 low rounded plications on each side of the mesial fold
and sinus with about 14 in each of the latter.

Iowa, Nevada, Athabasca.

BRACHIOPODA—TELOTREMATA. 295

274. H. cuboides (Sowerby). (Fig. 366, a—d.) Devonic.

Pedicle valve slightly less convex than the brachial and abruptly
depressed in a broad deep sinus. Umbo moderately elevated with
minute and closely appressed beak. Brachial valve very gibbous
with a defined mesial fold reaching above the middle of the shell
and sharply truncate in front, bearing 6 or 7 plications. Whole
surface covered with plications which are crossed by fine concen-
tric strize.

Tully of New York, Manitoba; Europe.

LXXXIJ. PuGnax Hall and Clarke.

Pedicle valve shallow with a deep median sinus. Brachial valve
deep with a much elevated median fold. Plications on lateral
slopes often obscure. Otherwise resembling Hypothyris. Upper
Devonic—Carbonic.

275. P. pugnus (Martin). (Fig. 366, ce) Upper Devonic.
Transversely ovate, z.¢., wider than long. Pedicle valve with
small, much incurved beak. Each valve has 9-14 plications which
become obsolete as they approach the umbo; from 3-6 occupy
fold and sinus. Length and breadth about I by I % inches.
New York, Nevada, Texas, Northwest Territory.

276. P. striatocostata (Meek and Worthen). Mississippic.

Subpentagonal, moderately gibbous, with length and breadth
about equal. Plications 9 to 11, broad and distinct, all except the
outer ones extending nearly to the umbos. Whole surface covered

. with distinct radiating striz and fine concentric lines.

Kinderhook of Missouri.

277. P. grosvenori Hall. (Fig. 366, ¢-/.) Mississippic.

Subglobose. Beak of pedicle valve small and nearly straight ;
that of brachial valve obtuse and closely incurved, meeting the
opposite valve nearly at aright angle. Sur-
face marked by 14-18 plications about 5 of

which mark fold and sinus. fs I
St. Louis of Kentucky, Indiana, Illinois. wisi
278. P. utah (Marcou). (Fig. 367.) Fic. 367. Pugnax
Carbonic. utah (Ind. Geol. Sur-
vey).

Small, emarginate anteriorly. Plications
angular, rarely exceeding 9 in number, of which 2—3 are on sinus
and fold.

296 NORTH AMERICAN INDEX FOSSILS.

Indiana, Illinois, lowa, Missouri, Kansas, Arkansas, Nebraska,

Utah.
LXXXIII. Eatonia Hall.

Anterior margin deeply sinuate. Pedicle valve nearly flat with
a broad deep sinus and small, perforate beak; muscle scars large
and deeply excavated. Brachial valve convex and often ventricose ;
cardinal process very long, resting upon a short median septum
and bifid at summit. Differs from ARhynchonella in the absence of
dental plates, in the presence of a cardinal process and in the
stronger muscle impressions of the pedicle valve. Devonic.

279. E. medialis (Vanuxem). (Fig. 368.) Devonic.
Hinge line nearly straight. Brachial valve regularly convex

from beak to front and elevated into a broad median fold. Pedicle.

valve somewhat convex at umbo and thence concave to the front

Fig. 368. “Aatonta meatalis (Pal. N. Y., IIT.).

and depressed into a broad sinus. Surface marked by 12-16 broad
plications of which 4 are on the summit of the fold and 3 in the
bottom of the sinus. |

Helderbergian of Maine, New York.

280. E. peculiaris (Conrad). (Fig. 369.) Devonic.

Longitudinally ovate. Hinge line much shorter and more
rounded than in £. medialis ; the mesial fold and sinus are much
less pronounced and the margins of the valves are denticulate.
Surface marked by fine radiating strie.

a

BRACHIOPODA—TELOTREMATA. 297

Helderbergian and Oriskanian of New York, Pennsylvania,
Maryland, Missouri, Quebec.

LXXXIV. RuyncHopora King.

Resembles Camarotechia but differs externally in its punctate
shell structure. Mississippic.

281. R. pustulosa (White). Mississippic.

Small, biconvex. Front broadly
rounded. Cardinal slopes straight-
ened. Surface marked by 16-22
simple rounded plications five of
which are on the sinusand fold each.

Kinderhook of Iowa, Utah, New
Mexico.

LXXXV. RHYNCHONELLA Fischer

de Waldheim. Fic. 369. Latonia peculiaris
. (Pal. N. Y., LII.).
Rostrate, subpyramidal. Apex

of pedicle valve but slightly incurved. Prominent median sinus
present on pedicle valve and fold on brachial in typical species.
In pedicle valve deltidial plates conspicuous; dental lamelle pres-
ent. In brachial valve a median septum present; no cardinal
process and no arm supports except crura. Surface radially pli-
cated. Ordovicic (?)—-Eocenic.

A. Plications present only upon anterior portion of shell ......... 285. &. eguiplicata.
Oa Dresent UPON ertire shell .i.2.15.i...cessevsdeswsvorvatesead Sedvereevecscnewovee 7H
*“Oatline subtrigonal. Shell less than 1 inch Wide. .......iccccsescscceasesect seees I,

1. Median sinus bearing less than 6 plications ........... 286. 2. gnathophora.

fe median sinus bearing 6-or more-PlHCAatiONs.:.., ...000...0.sscecsencsosececeeasee a.

DB. oumace, With 20 tO 25 pPliCAliONS: 20.02. fs.cs ec cececses 283. R. hubbardi,

a oubace With more than, 20-tO 25. HlicAtiONS .2..5....02 snes eoenesses. rE.

1’. Shell small, a half inch or less in width... 282. 2. eurekaensis.
1’. Shell of medium size, more than a half inch in width.
= 284. RR. myrina.
282. R. eurekaensis Walcott. (Fig. 370.) Mississippic.
Small, subtrigonal in outline. Width and length subequal.
Brachial valve slightly deeper than pedicle. Pedicle valve with a
prominent, projecting beak and with a rather shallow sinus that
forms about half the width of the shell anteriorly. Brachial valve
with a slight median fold; umbo strongly incurved. Surface of
each valve with 40 to 50 round, simple plications.
Nevada; Arkansas? (Spring creek limestone).

298 NORTH AMERICAN INDEX FOSSILS.

283. R. hubbardi A. Winchell. Mississippic.

Small. Cardinal slopes straight. Greatest width about the
middle of the shell. The two valves equally convex. Front
gently rounded. Pedicle valve with a broad,
shallow sinus occupied by 8 or 9 plications.
Brachial valve with no fold perceptible but
with a shallow sinus extending from the beak
for about one third the length of the shell.
Surface covered with about 21 narrow pli-

Fic. 370. Ahyncho-
nella eurekaensts. (Af-

ter Walcott. ) cations.
Waverly of Ohio, Marshall of Michigan.
284. R. myrina Hall and Whitfield. Jurassic.

Of medium size, broadly ovate with greatest diameter below the
middle. Brachial valve the deeper, nearly evenly convex from
beak to front and with a slightly elevated median fold. Pedicle
valve with a prominent projecting beak and a broad, moderately
depressed median sinus. Surface marked by 31-34 low, rounded
plications, 8-10 of which occupy the fold and sinus.

Dakota, Utah. |

285. R. equiplicata Gabb. Triassic.

Subglobose. Valves equally convex. Beak large, prominent
and incurved. Sides sloping convexly to extremities of hinge
line. Surface with about 14 nearly equal, rounded ribs, beginning
on each valve about one third the distance from beak to front; the
furrows equalling the ribs in width. Length and width about I
inch each but length slightly exceeding width. Growth lines
faintly developed.

Trias of Humbolt Mt., Nevada.

286. R. gnathophora Meek. Jurassic.

Of medium size, subtrigonal, with greatest convexity near the
middle. Postero-lateral margins straight, diverging from beak
at an angle of 80° to 100°. Brachial valve usually the more con-
vex, especially near the front where it rises into a median fold
traceable for about half the way toward the incurved beak. Pedicle
valve with a corresponding sinus; beak pointed. Surface with 16
to 20 simple plications of which three or four are in the sinus and
four or five on the fold. Length about .8 inch and breadth about
.7 inch.

Jurassic of California and Utah.

BRACHIOPODA—TELOTREMATA. 299

LAXXVI. PEREGRINELLA Céhlert.

Shell large, pedicle valve generally the more convex. Valves
without median fold or sinus; with even margins and plicated sur-
faces. Beak short, false cardinal area and deltarium present.
Cretacic.

287. P. whitneyi (Gabb.). (Fig. 371.) Cretacic.

Large, subcircular in outline; the two valves about equally
convex. No median fold or sinus present. Surface marked with
40 to 50 narrow, angular plications
which are equal in breadth to the deep,
angular interspaces. When young the
shell is much longer than wide. Length
and breadth each about 1% inches in
maturity.

Knoxville of California.

LXXXVII. CENTRONELLA Billings.

Usually small, terebratuloid in out-
line. Pedicle valve convex, angular in
the center; beak acute and incurved
with a terminal foramen, which is con-
tinuous with a partially closed delthy-
rium. Brachial valve plane or concave,
depressed into a median sinus. Brachid-
ium in two branches uniting medially into a triangular plate bear-
ing a median ridge. Devonic—Mississippic.

PiG. ~.37%. Pereerinela
whitneyt?. (After Stanton. )

288. C. glansfagea Hall. (Fig. 372, a-c.) Devonic.

Very small, broadly ovate. Pedicle valve much the larger, reg-
ularly arcuate from beak to front; beak much extended and
strongly incurved. Brachial valve convex above and concave in

d
Fic, 372. a-c, Centronella glansfagea. (After Nettelroth.) @-e, C. tmpressa.
(Pats ie Yogi Va he

300 NORTH AMERICAN INDEX FOSSILS.

the middle through a broad, undefined sinus; beak not incurved.
Surface smooth or with faint concentric growth lines.

Oriskany—Onondaga of New York, Kentucky, Indiana, Michigan,
Ontario.

289. C. impressa Hall. (Fig. 372, d-e.) Devonic.
Pedicle valve angularly convex. Brachial valve small with front
produced and curved downward to fill the sinuosity in the front of
the pedicle valve. Surface covered with fine concentric and faint
radiating striz.
Hamilton of New York.

LXXXVIII. RENsSEL@RIA Hall.

Oval or suborbicular, usually gibbous. Beak of pedicle valve
prominent, acute and incurved. Valves without mesial fold or
sinus. Brachial valve with large hinge plate; brachidium form-
ing a broad plate anteriorly and giving off two small, rod-like
processes posteriorly. Surface radially striated or finely plicated.
Shell structure punctate. Devonic. }

290. R. equiradiata (Conrad). ~ Devonic.
Elliptical, with nearly equal valves. Pedicle valve often sub-

angular along the center toward the umbo, with beak incurving

over that of the opposite valve. Surface marked by simple radi-

ating striz, which are most conspicuous near the margin.
Helderbergian of New York, Nova Scotia.

Fic. 373: Rensseleria ovoides (Pal, N. Y., III.).

291. R. ovoides (Eaton). (Fig. 373.) Devonic.

Length usually much exceeding the breadth, broadest above the»

BRACHIOPODA—TELOTREMATA. 301

middle and abruptly rounded toward the cardinal extremities, nar-
rowing toward the front. Surface marked by simple radiating
striez. Distinguished from R. @guzradiata by its different form,
larger size and more prominent striz.

Oriskany of New York, Pennsylvania, Maryland, Virginia,
Quebec.

292. R. cayuga Hall and Clarke. (Fig. 374.) Devonic.
Lenticular, often large, suboval in marginal outline. Valves
subequally biconvex. Very similar to A. @guiradiata, from which
it differs principally in its suboval marginal outline and in its large
size.
Upper Oriskany (Decewville) of Ontario.

Fic. 374. Rensseleria cayuga. Fic. 375. a-c, Cryptonella planirostris with
(After Hall and Clarke. ) beak of pedicle valve enlarged; a-e, C. rectt-
FAUTIS. Ce abn Yo. Y:

LXXXIX. CRYPTONELLA Hall.

Elongate-oval, unequally convex, usually without median fold
or sinus. Pedicle valve with extended and incurved beak, per
forated by a terminal foramen. Surface smooth or marked by
concentric strie. Shell structure finely punctate. Devonic—Mis-
sissippic.

293. C. planirostris Hall. (Fig. 375, a—c.) Devonic.
Often subpentagonal in outline. Pedicle valve with moderately
incurved beak. Brachial valve much shorter than the pedicle
Surface marked by fine concentric striz.
Marcellus and Hamilton of New York.

302 NORTH AMERICAN (INDEX, FOSSILS.

294. C. rectirostris IIall. (Fig. 375, a-e.) Devonic.
Distinguished from C. planirostris by its more elongate form and
extended and attenuate beak.
Hamilton of New York, Kentucky, Indiana.

XC. DieEcasMaA King.

Terebratuloid. Pedicle valve with a large foramen. Brachial
valve with a large, anteriorly acuminate hinge plate (muscular
platform) raised but little above the bottom of the valve and some-
times actually adhering to it. Brachidium a relatively short and
simple loop, consisting of descending lamelle, and a backward
arching transverse band. Devonic—Carbonic.

295. D. (Cranena) romingeri Hall. (Fig. 376, a-c.) | Devonic.
Small, ovate, with rounded cardinal slopes. Concentric striz
often crowded into wrinkles near the front.
Hamilton of New York, Michigan,
Indiana, lowa.

field). | Devonic.
Shell about-1% inches long by 14%
inches wide and about 54 inch in
greatest thickness. Pedicle’ valve
with umbo curved so that its fora-
Fic. 376. a-c, Dielusma (Cran- men is at right angles to the plane of
ena) romingeri (Pal. N. Y.,1V.)} separation of ‘the valves. | -Bracma
a-f, D. turgidum. (After Whit- . : .
; valve usually with a median fold near
field. )
the front. Surface smooth except

for a few concentric growth lines.
Chemung of Iowa, Northwest Territory.

297. D. turgidum (Hall). (Fig. 376, ¢/.) Mississippic.

Longitudinally ovate, often very gibbous, emarginate in front.
Sinus present in pedicle valve and sometimes in brachial. Surface
marked by strong concentric growth-lines and occasionally by
strong wrinkles in the anterior portion. Differs from D. romingert
in its greater gibbosity and in the more strongly marked sinus of
the pedicle valve.

Warsaw and St. Louis of Ohio, Kentucky, Indiana, Illinois,
Missouri, Iowa.

296. D. calvini (Hall and Whit-

BRACHIOPODA

TELOTREMATA. 303

298. D. bovidens (Morton). (Fig. 377.) Carbonic.

Elongate, ovate, averaging about 2 inch in length by } inch in
breadth. Pedicle valve strongly arcuate with prominent, incurved
beak and broad mesta! sinus, extending anteriorly from the middle
of the valve. Brachial valve
almost straight along the
median line from the ante-
rior margin to about the
middle where it begins to
curve gently to the beak;
mesial fold usually entirely
lacking. Surface nearly
smooth. This is larger than D. romngera and lacks its broader
ovate character. It differs from D. ¢urgzdum in its larger size,
less gibbous form and less emarginate anterior portion.

Widely distributed through the central United States.

Fic, 377. Dielasma bovidens (Ind. Geol.
Survey ).

XCI. Euxecra Hall and. Clarke.

Differs from Dielasma in the absence of the large hinge plate.
Devonic.

299. E. linckleni Hall. (Fig. 378.) Devonic.

Terebratuloid. Pedicle valve at times with a narrow mesial de-
pression; beak more or less abruptly incurved; umbonal slopes
concave toward the cardinal
margin. Surface of both valves
Gieteed. by fine. concentric
growth lines. Shell structure
_ punctate.

Marcellus and Hamilton of
New York, Michigan, Indiana.

XCII. TEREBRATULA Klein.

Form terebratuloid, elongate
biconvex generally with median nce
flattening or’ depression oa Each Fic. 378. LEunella ‘iaitcnioantas Views

: of two individuals showing variation ( Pal.
valve. Surface not striate; x y. ry.»,
deltidial plates complete. Loop
short, unsupported by a median septum at any stage of growth.
(Fig. 380.) Devonic(?)—-Recent.

304 NORTH AMERICAN INDEX. FOSSILS.

300. T. P humboldtensis Gabb. Triassic.

Of medium size. Front truncate and marked by a simple or
double fold and sinus. Pedicle valve slightly flattened across the
middle. Beak broad, prominent, but slightly incurved and trun-

Fic. 379. Zerebratula harlani. ‘Example of average size. (After Whitfield.)

cated by a large foramen. Cardinal borders strongly inflected and
flattened, forming an angularity along the edge of the beak. Sur-
face smooth except for strong and irregular concentric growth
lines. |

Triassic of Nevada and Nicola Lake, Canada.

301. T. harlani Morton. (Figs. 379 and 380.) Cretacic—Eocenic.
Large (sometimes 234 inches long),elon-
gate-oval with subparallel sides. Front

more or less truncate, at times slightly bilo-
bate. Valves very ventricose, covered with
concentric growth lines. Pedicle valve with
large beak, strongly incurved; foramen

Fic. 380. Terebratula large. Shell substance finely punctate.
oe ce ay Upper Cretacic (Rancocas) of New Jer-
sey, Delaware, South Carolina. Eocenic

of Maryland.
XCIII. TereBRATULINA d’Orbigny.

Ovate, biconvex. Cardinal extremities faintly auriculate. Ped-
icle valve with circular foramen; deltidial plates small, generally.

BRACHIOPODA—TELOTREMATA. 305

incomplete; dental plates wanting. Brachial valve with small car-
dinal process; hinge plate and median septum wanting; socket
walls prominent, supporting a short Dzelasma-like loop with the
crural spines typically united into a transverse band or jugum.
Surface finely radiate. Jurassic—Recent.

302. T. atlantica (Morton). (Fig. 381.) Cretacic.
Ovate. Valves unequally convex. Length about 3{ inch;
width % inch. Pedicle valve with large foramen; beak not in-
curved. Both valves covered
with numerous _ bifurcating
strie. .
Upper Cretacic (Manasquan)
Staten Island and New Jersey.

XCIV. Tropipo.Lertus Hall.

Form strophomenoid. Hinge
Jine straight; area well devel-
oped. Pedicle valve convex
with two broad divergent teeth and open, subcircular delthyrium..
Brachial valve concave or flat with large cardinal process bilobed
at summit. Teeth and dental sockets corrugated on their outer
surfaces. Shell substance highly punctate. Loop of descending
lamellz joined to median septum. Devonic.

Fic. . 381. Terebratulina atlantica.
(After Whitfield. )

303. T. carinatus (Conrad). (Fig. 382.) Devonic.
Plications simple, rounded, wider than the interspaces. Central
plication of pedicle valve broader and higher than the rest. Con-
centric striz fine with occasional coarser imbricating lamelle.
Marcellus and Hamilton of New York, Pennsylvania, Ohio.
Kentucky, Indiana, Illinois. Also foreign.

XCV. KINGENA Bacidsan,

Suboyate, biconvex, inequivalved ; terebratuloid in outline, con-
vexity and foramen. In brachial valve a cup-like hollow between
the sockets gives rise toa median septum extending about half the
length of the valve. Loop more complicated than in Zeredratula,
Shell structure punctate. Comanchic.

304. K. wacoensis (Roemer). Comanchic.
Pentagonal, frontal margin straight. Both valves very convex.
Pedicle valve with beak greatly incurved and with a distinct car-

306 NORTH AMERICAN INDEX FOSSILS.

Fic. 382. Zropidoleptus carinatus. External and internal views (Pal. N. Y., 1V.).

dinal area. Surface marked only with a few concentric growth
lines, :
Washitan of Texas, Vancouver Island.

XCVIJ. TEREBRATELLA d’Orbigny.

Plicated Terebratuloids, with straight or slightly curved hinge
line. Loop composed of descending and ascending branches, sup-
ported by a median dorsal septum throughout life or only in the
younger stages. Lias-Recent. |

305. T. plicata (Say). (Fig. 383.) Cretacic.
Subcircular, somewhat plano-convex, marked by 8-12 or some-
times more, sharply angular plications which extend from beak to

Fic. 383. TZerebratella plicata. Dorsal and side view ; and interior of brachial valve
enlarged. (After Whitfield. )

front. Pedicle valve strongly convex with an erect beak of small
size; foramen large. Structure strongly punctate.
Upper Cretacic (Matawan and Monmouth) of New Jersey, etc. »

BRACHIOPODA—TELOTREMATA. 307

306. T. vanuxemi Lyell and Forbes. (Fig. 384.) Cretacic.
Valves more convex than preceding, plications more numerous,
less angular and less distinct, except occasionally in central portion
of valve.
Upper Cretacic (Monmouth) of New Jersey, etc.

Fic. 384. 7Zerebratella vanuxemi, Dorsal and side view of average form; dorsal
view of more finely plicate form. (After Whitfield. )

XCVII. Zycospira Hall.

Subcircular, biconvex. Like Azvypfa but smalland with a median
plicated fold in the pedicle valve. Brachial valve marked by a
median sinus; cardinal process stout, bilobed. Spirals composed
of fewer coils than in A¢vypfa and turned inwards; primary lamellz
united by transverse jugum (Fig. 385, ¢); surface sharply plicate.
Ordovic-—Siluric—? Devonic.

307. Z. recurvirostris (Hall). (Fig. 385, a-e.) Ordovicic.
ILength slightly exceeding width. Smaller than Z. modesta.

Fic. 385. a-e, Zygospira recurvirostris ; nat. size and three views enlarged 2
(¢) brachidium still more enlarged & 4; f-2, Zygospira modesta, naturalsize’and three
enlarged views >< 2. (After Winchell and Schuchert. )

Trenton of New York, Kentucky, Wisconsin, Minnesota, On-
tario, Manitoba.

308 NORTH AMERICAN INDEX FOSSILS.

308. Z. modesta Hall. (Fig. 385, 42.) Ordovicic.

Width slightly exceeding length. Hinge line somewhat ex-
tended. Pedicle valve convex with a median ridge occupied by
four stronger plications; beak prominent and incurved. Brachial
valve depressed-convex and nearly circular with an ill defined
mesial sinus. Plications simple, about 18.

Utica to Richmond of New York, Ohio, Missouri, Wisconsin,
Iowa, Minnesota, Ontario. Clinton of Ohio.

308a. var. cincinnatiensis James. Ordovicic.
Differs from the preceding in its larger size, more pronounced
median fold and sinus, and coarser, more angular bifurcating pli-
cations.
Cincinnatian of Ohio, Tennessee, etc.

309. Z. nicoletti Winchell and Schuchert. (Fig. 386, a—c.)
Ordovicic.
Very small, usually not much exceeding % inch in width.

Length greater than breadth. In these respects it resembles Z.
recurvirostris ; it differs from that species in the faintness of its

Fic. 386. a-c, Zygospira nicolett?, three views much, enlarged ; a-h, Cyclospira
bisulcata four views enlarged 2; and brachidium still further enlarged & 4. (After
Winchell and Schuchert. )

plications and in the presence of a sinus on the pedicle valve and
a fold on the brachial, being in these respects exactly opposite.
Trenton of Minnesota, Wisconsin and Missouri.

Ss”

387.) Siluric.

lines.

BRACHIOPODA—TELOTREMATA. 309

XCVIII. Cyctospira Hall and Clarke.

Subquadrate. Pedicle valve very convex with a prominent, in-
curved umbo and keeled posteriorly with a median sinus anteriorly.
Brachial valve depressed, bearing a low median fold anteriorly ;
cardinal process small, supported by a low median septum.
Brachidium very simple (Fig. 386, 2). Surface smooth. Ordovicic—
Siluric.
310. C. bisulcata (Emmons). (Fig. 386, a—/.) Ordovicic.

Small. Beak of pedicle valve defined on each side by two ele-
vated ridges curving to the lateral margins of the valves.

Trenton of New York, Minnesota, Ontario, Manitoba.

XCIX. AtrryPA Dalman.

Subcircular, strongly inequivalved. Hinge line short. Brachial
valve very gibbous. Pedicle valve much less convex or nearly flat
with a small, incurved beak and bearing a median sinus. Teeth
large and widely separate. Muscu-
lar impressions strong. Spirals di-
rected dorso-medially; jugum in
extreme posterior portion. Surface
radially plicate. Siluric — Missis-
Sippic.

311. A. nodostriata Hall. (Fig.

Valves subequal. Surface nod-
ulose because of the lamellose growth

Clinton and Niagaran of New

York, Ohio, Kentucky, Wisconsin. _F!6- 387. 4éypa_nodostriata,
with striz enlarged (Pal. N. Y.

312. A. marginalis (Dalman). II.).
Siluric.

Length and breadth subequal. Beak of pedicle valve incurving
over, but not covering that of the brachial valve. Both valves
convex, the pedicle with a well-marked median sinus, bounded on
each side by one or two stronger plications, and the brachial with
a correspondingly well developed fold. Entire surface marked by
radiating plications, which are crossed by concentric striz; these
latter are often obsolete.

Niagaran of Kentucky, Tennessee, Ohio, Indiana, Illinois.

310 NORTH AMERICAN INDEX FOSSILS.

313. A. rugosa Hall. (Fig. 388.) Siluric.

Smaller than A. nodostitata and with equally convex valves.
Surface marked by strong sinus and}fold and concentric rugose
lamellz and by plications which
are less rounded than in A. xo-
dostriata.

Niagaran of New York, Ken-
tucky, Indiana, Anticosti.

314. A. reticularis (Linnzus).
Fic. 388. Atrypa rugosa, with stric LEIe®. 359; on 389, Bs 392,
enlarged (Pal. N. Y. II.). - aC.) Siluric and Devonic.
Pedicle valve often nearly

flat. Surface reticulated by the radiating and concentric striz.
A characteristic Siluric and Devonic fossil throughout the world.

Fic. 389, a. Alrypa reticularis (Helderbergian) (Pal. N, Y. III.).

lic. 389, 6. Atrypa reticularis (Onondaga) (Pal. N. Y. IV.).

315. A. impressa Hall. (Fig. 390.) Devonic.
Differs from A. reticularis in being more gibbous, in the absence

of a sinus in the pedicle vaive and in the depression of the brachial

valve toward the front. The striz are finer and less conspicuous.
Schoharie of New York, Michigan. | |

BRACHIOPODA—TELOTREMATA. cee

Fic. 390. <Atrypa impressa, with interior of pedicle valve (Pal. N. Y. IV.).

316. A. spinosa Hall. (Figs. 391 and 392, @.) Devonic.

i Hinge line but little less than the greatest width of the shell. Sur-
face marked by strong, rounded, radiating coste which bifurcate at
unequal intervals and are crossed by strong concentric lamelle;
where these cross the costz they are often
produced into tubular spines. Differs
from? A. reticularis in the smaller number of
| poses sand : inthe longer and more nearly
: straight hinge line.
| Onondaga—Chemung. Widely distrib-

uted throughout North America.

317. A. hystrix Hall. (Fig. ae if si Fic. 398. Atrypa- sph
mosa, a spineless individual
Differs from <A. spinosa in its fewer, (Pal. N. Y. IV.).
coarse, rounded plication which are crossed
byjlamellose lines of growth and occasionally prolonged into few.
coarse spines.
Chemung of New York, Pennsylvania, Iowa and Wisconsin.

f

317a. A. hystrix var. occidentalis Hall. (Fig. 392, 7) Devonic.
Gibbous, with few coarse plications and strong lamellose growth
lines but no spines.

Middle Devonic of Iowa and Robe Island, Ill.

Fic. 392, a-c. Atrypa reticularis ; a, interior of pedicle valve ; 4, cardinal portion
of brachial valve ; ¢, spirals showing after removal of brachial valve ; ¢, Atrypa spinosa ;
e, Atrypa hystrix; f, A. hystrix var. occidentalis. a, adductor scars; 4, dental
sockets ; c, crural bases; 44, hinge plate; 4, pedicle scar; 7, diductor scars ; 57,
crenulated ridge in sockets. (After Hall and Clarke. )

C. Cyrtina Davidson.

Small, spiriferoid, with very unequal valves. Differs from Spzvifer
in the semipyramidal form of the pedicle valve, the high, flat car-
dinal area and the narrow delthyrium closed by a convex pseudo-
deltidium which is usually perforated by acircular foramen. Shell
structure punctate. The dental plates converge from the inner
margins of the delthyrium and unite with the median septum,
which reaches to the front, thus dividing the interior of the valve
into two parts. Siluric—Mississippic.

A. Cardinalaréa of pedicle valve strongly ‘arched .).....,.......s0+see +000 .caaten (teen x;
eoneliiiarpe, more thai ineh: WIE. (cs. sides s.scsdeees aveces 321. C. alpenaensis.
* Shell small, less than’ 4) amch: Wide 4.5. .ve.aescntews oaeiennsen os 320. C. umbonata.

BRACHIOPODA—TELOTREMATA, 313

weecardinal areaof.pedicie.valve not ‘strongly arched). » civesvsssscncwosscaneursewecsace cake
a Deak iicurved: and. promoumced..,..0cs.4.isssesccss sass outa 319. C. hamiltonensis.

** Beak inconspicuous. Cardinal area of pedicle valve almost vertical............ P:

I. 2 to § plications on each side of fold and sinus........ 322. C. acutirostris.

I. 6 to g plications on each side of fold and sinus............ 318. C. dalmani.

318. C. dalmani (Hall). Devonic.

Brachial valve semicircular; mesial fold flat; beak scarcely de-
fined. Concentric lamelle strong. Surface granulose-punctate.

Helderbergian of New York, Tennessee, Missouri and New
Brunswick.

319. C. hamiltonensis Hall. (Fig. 393, a—c.) Devonic.
Beak slightly incurved and frequently distorted. Surface marked
with 6-8 plications on each side of the well marked sinus and fold.

a

Fic. 393, a—-c. Cyrtina hamiltonensis ; d-e, Cyrtina alpenensis
(Pato NY, LY. and Vi.)

Onondaga, Hamilton and Portage; distributed throughout North
America.

320. C. umbonata (Hall). Devonic.
Differs from C. hamiltonensis in its broader, arcuate and incurved

-umbo and beak and in that the 5 or 6 plications on each side of

the mesial fold and sinus become obsolete before reaching the
umbo, thus leaving that smooth or nearly so.
Hamilton of Illinois, Missouri, lowa, Michigan.

321. C. alpenaensis Hall and Clarke. (Fig. 393, de.) Devonic.
Very similar to C. wmbonata but is larger, with broad well de-
fined plications and smooth median fold and sinus.
Hamilton of Michigan.

322. C. acutirostris (Shumard). Mississippic.
~ Small. Pedicle valve with very high and nearly vertical cardinal
area. Brachial valve depressed-convex. Surface with two to five
simple rounded plications on each side of the median fold and
sinus; these are crossed by imbricating growth lines. Differs

314 NORTH AMERICAN INDEX FOSSILS.

from C. wmbonata in its smaller size, wider hinge line and higher
cardinal area.
Chouteau of Missouri.

Cl Cyrrima Dalman:

Semipyramidal shells with cardinal area vertical, that of the
pedicle valve high and triangular. Delthyrium narrow, generally
open. Otherwise like Spzvzfer. Siluric—Mississippic.

323. C. alta Hall. (Fig. 394.) Mississippic.

Semipyramidal with hinge line equaling the greatest width of
shell. Pedicle valve very elevated ; height to width about as three
to five; sinus broad and rounded?
cardinal area vertically striated. Bra-
chial valve depressed-convex; car-
dinal area comparatively wide ; sur-
face marked with 25 to 30 low,
rounded plications on each side of
the median fold. Median fold and
sinus faintly plicated.

Waverly of Pennsylvania and

Ohio.

CII. SprriFERINA d’Orbigny.

Differs from Cyrtina in that the
: dental plates do not unite with the
Fic. 394. Cyrtia alta & 2 (Pal. ‘ ; ‘

N. Y, VIII.). high median septum and in that the

valves are less unequal in_ size.

Shell substance punctate. Devonic? Mississippic—Jurassic.

324. S. spinosa (Norwood and Pratten). (Fig. 395.)

Mississippic—Carbonic.
Of less than medium size, semioval. Brachial valve with prom-
inent median fold. Pedicle valve slightly more convex than the
opposite with strongly defined mesial
sinus and slightly arched beak Sur-
face bearing four or five sub-angular or

rounded plications on each side the ye.
A : : Fic. 395. Spiriferina spinosa,
fold and sinus, crossed by imbricat- . \iscsissippi Valley anda Nev-
ing lamellz of growth. Whole surface ada specimen. (After Walcott. )

.

:
|
:
:
.
|
|
(
.
|
:

:
4

BRACHIOPODA—TELOTREMATA. 315

finely punctate. Numerous, irregularly scattered, small spines
present.

Kaskaskia of Kentucky, Indiana, Illinois. Upper Devonic?
Mississippic and Carbonic of Nevada.

325. S. kentuckiensis (Shumard). (Fig. 396.) Upper Carbonic.
Small, varying in outline from subcircular to transversely pro-
duced. Differs from 5S. sfzzosa in its smaller size, pointed hinge
extremities and greater number of plications (10-18).
Widely distributed in North America.

Fic, 396. Spiriferina kentuckiensis (Ind. Geol, Surv.).

CIII. SprriFER Sowerby.

Usually much wider than long, radially plicate or striate, crossed
by concentric growth lines. Hinge line generally long and straight.
Usually a median sinus present on pedicle valve and corresponding
fold on brachial. Pedicle valve with moderately high area and
open delthyrium, the margins of which are prolonged into stout,
simple teeth supported by dental lamellae. A calcareous brachid-
jum in the form of a double spire, whose apexes are directed
toward the cardinal extremities nearly fills the cavity of the shell.
Jugum incomplete. Cardinal process low. A median septum at
times present in one or both valves. Siluric-Carbonic.

A. Plications absent. Strong radiating striz present................06. 326. S. radiatus.
METERS NYE RAs 80 calc. ay ce Specs Sistas es veka weds 65 apiinda sdlcae vad vow esvavevsacereaeonaces cat
* Plications covering entire surface................ PMN eee Sas sentir cae Guile has gn nes T-

ft Plications arranged in bundles or groups (fasciculate)................ceeee ees i
perncations of neatly €qual size .. 62. ccccseves. cals sae sean 371. S. striatus.

} Piieations of umequal size ®ii lies .s ee ici) Nasseice. 372. S. cameratus.

RE EOTEMSIM IE TAOCICUNALE palace yea dyaiice bok s ¥-'" lav fo vcwielaCieos oie w oc ua 0d enive’s Ae

tt Plications on fold and sinus nearly or quite like those on rest of

og we sig: hacia By gee, SEA ey eae er ae [.

PE TOPPER WORLIICHBS ach caneas Noose aalen grees ov waasds scsaulnetuns tesa a.

a, Length exceeding breadth, very large...... 366. S. grimesi,

See, SSMCH CRCOCAIMG TOUTING. .ncacceh cack swears excess din'seusse ses .

1’. Sinus prominent, much produced anteriorly......... a’.

a’. Beaks of both valves very prominent and arching.
346. S. divaricatus.

a’. Beak of pedicle valve much more prominent than
PGE ORIRACIIAN wi. hov ccs: woscsess 368. S. logani.

316 NORTH AMERICAN INDEX FOSSILS. ;
1’, Sinus not produced anteriorly......... 339. S. arenosus.
i: Shellof medium: size ang Convexity.,.....5.1sss0cais.eucsaevabeotoes b.
Oey GUS OE ATED WY fs Sa asics onic ws nese end ca eee eee an
Be lie rAMMIOSe'.: css eay areal es 365. S. marionensts.
2 este Gk mranelonts 6 wiietscscsass <oike <a> eeu eak eevee b/,
o’, Hinge line extended.......... 364. S. centvonatus.
6’. Hinge line not extended......... 371. S. striatus.
by Cardinal, area moderately high, . 0. :.j.0i..5.0..02 ace vcaeeee 7:

3’. Hinge line shorter than width of shell below.
373. S. rockymontanus.
3’. Hinge line forming greatest width of shell (usually
recognized by internal mold).... 361. S. disjnctus.
tf Plications on fold and sinus extending only part way to the beak and

hence ‘differing from the other plications... .........cc0sssessescasese 24

2. TCAs APM os cue eterna es caeetink daha) slcgas's= 369. S. letdyt.

2. Plicationsamounded 0c, 45.016: setuagmadeh sodas «sadn eneny bine ae re

c. Cardinal extremities rounded. ..............ceceeeees se ohueeeeae 4’.

4’. Plications of sinus unequal............... 342. S. griert.

4’. Plications of sinusiequali.. 2 .c..sesscae. 363. S. keokuk.

4’, Plications of sinus: obscures... 2... 337. S. concinnus.

¢. Cardinal extremities angular..... ee 370, S. increbescens.

* Plications covering all the surface but fold and sinus - ...... ......00s0sseassumen TT-
tt Plications crossed by more or less conspicuous concentric lines, often pro-
ducing: a lamelose appearance ...0. 57.0601 cds emiet ncmednae eee Tt.
ttt Shell small, usually less than 1 inch wide .........ciscdees Gee 3-
3. Hinge line usually shorter than width of shell below........... d,

@.. Furrow in median fold .o2. c..ccinces casces 331. S. vanuxemt,

a. No furrow in’ median fold... .......0:.s0-s0sceces +00 ces eee

5’. Plications’ obsolescent ........;... 333. S. corallinensis.

5’. Plications well developed.......0:...+¢ 330. S. crispus.

a Esme Lime extended... .+ gepedanssacdassed 2dnees dyno f,

e. Plications 4-7 on each side fold and sinus... 329. S. sulcatus.

e. Plications many on each side fold and sinus............... oO";

6’. Front broadly rounded......... ..... 344. S. varicosus.

6’. Front narrowly rounded owing to the often mucro-

nate hinge extremities ....... weve 362. S. subattenuatus.

+tt Shell 1 inch or more wide except if young............... ee 4.
4. Furrow in fold of brachial valve, hinge line extended.. ........ fi

J. Cardinal areas: Natrow .ois..ceiwe.si%- sawovesscenceohene seen ge

7’. Plications few and absent from the cardinal extremities.
357. S. sculptilis.

ot PMCBHONS TRAD: 5225015000. scsgeures 354. S. mucronatus.

J. Cardinal a¥eas Wide... scecisiccswes «ete cece - seen ean ee

8’. Beak prominent........ ee een cer 356. S. consobrinus.

8 , emi SiMe IL Es 1282 ia. eisai edits Sede on 360. S. mesicostalis.

4. No, furrow in fold of brachial valve.............s00s:s000he0eeeeen £e
g. Hinge line shorter than width of shell below............... fe

9’. Beak of pedicle valve much elevated.

337. S. concinnus.
9’. Beak of pedicle valve not much elevated.

336. S. cyclopterus.

BRACHIOPODA—TELOTREMATA. 317

By ORD Tige THME SRNONGE, 8 sn5 cichen ne vous naa Cokes eee emda 10°.

Is Creel SECA MIG 2 co. os cst eceacs vecudecaenemoae meee c!,

c’. Plications few (2-5) on each side the mesial fold

MC SUDMIS occ 5 oe enup oat Ree eae 22.

22. Plications broad, nearly equalling the mesial

SUS Ir WEEE 235.4). daca 343. S. varicosta.

22. Plications much narrower than mesial sinus.

335. S. perlamellosus.

67>. PHCAMOUS INANY soonest uccea sexs 338. S. murchisont.

HOS. Cardia ara Liat). c.c.yiviciencast tinder eacsuohs Semckine &

ad’. Plications few (7 or 8on each side the mesial fold

aNd SINGS): 25 haadusasvens 340. S. duodenarius.

ck Weations. WARY a. ..02 vse. 200% 354. S. mucronatus,

meeesications marked by radiating Strige si i500. iieace ois veeecd acess seaspense Ft tt.
Py ONG It) RCW WERE a) 5.x, eerret ionws rs inahs cine vexicapaeh svn dadosliuevecaxe ie

5. Plications few (3-4 on each side the mesial fold and sinus).
327. S. eudora.

roqak gic Gre MT SaaS 38 Bs Seta RR et CCR h.
A. Shell small (3 inch wide).,............ eae 358. 5. callius.
#:. Shell-of mediunr size of large: wie sess vee secevs uoschnuns RI’:

11’. Hinge line much extended. Shell often inequilateral.
351. S. cowaensis.
11’. Hinge line only slightly longer than width of shell

e’. Cardinal area subsemicircular.. 347. S. ery leines.
e’. Cardinal area subtriangular,..... 348. S$. fornacula.
eet SMe) AEM TIMEUOW), us qsinds dacorden caudate» hove: caasatens axsemobens Baus Ob
6. Plications few (2 or 3 on each side mesial fold and sinus).
334. S. macropleura.
Sree Sch MMM TUAMLNT, ead Swae Sete Pane sues lake Wipic tux oe a cule oe Aide tes vieinn Ue se 2.
z. Fold and sinus rapidly expanding. Shell large.
359. S. mesistriahs,

z. Fold and sinus slowly expanding...... 328. S. niagarensis.

Plications granulose, sometimes in radiating lines........... cece ceseeeees 5i.

aa Ssioowe\ Usually presentin fold; Shell. large sci... 1c. veaens ossndeaseoee 7s

7. Granules scattered, sinus deep, angular...... 350. S. granulosus.

7. CGramiles in lines, smus rounded... ......0....0..000.0- 349. S. owent.

5{t No groove in fold. Shell of medium size,.............. 355. S. asper.

EME CATIONS AParE tly STMHOGLH, 25. 406.5) 1cue-gduuwensGs apse seecnacsseeuvasswoness 6t.
Sd SOPHIE WOT Yo OM OR debs saat. 2 te vambens chceuien asi yicetiia ces seunesenssbiansene 8.

Oi eat OVE eS WO OMOS WAKE nrc ipasizenadrariew amie Sisscenss «poses aadess Hie

Jj. Hinge line shorter than width of shell below.
367. S. neglectus.
j. Hinge line forming greatest width of shell................. ie fe
12’. Shell very ventricose with prominent triangular fold.
345. S. acuminatus.
12’. Shell moderately gibbous with low, rounded fold. /”.

J’. Plications numerous (30-35)........ 349. S. cwent,

J’. Plications few (10-16)........ 338. S. murchisont.

8. Small (about 3/ inch wide), often with conspicuous concentric
lines developed toward: the front..5...:5..ccsc0ccacess ecsesees k.

318 NORTH AMERICAN INDEX FOSSILS. 3
&, Plreations well. developed. ..)..csccccsevssso. 341. S. gregartus.
#. Plications nearly obsolete..;...........03..000 332. S. erzensis,
6 Shell moderately convex with extended hinge line...............0000 9.
9. Proportion of length to breadth as I-3......... 353. S. angustus.
9. Proportion of length to breadth as I-2........ 352. S. audaculus.
326. S. radiatus Sowerby. (Figs. 397, 398.) Siluric.

Beak of pedicle valve strongly incurved ; cardinal area moder-
ately high. Median sinus broad and shallow; median fold flat-

FIG. 397. Spirifer radiatus Smith, Westerntype. (After Hall.)

Fic. 398. Spirifer radiatus. New York type showing variation (Pal. N. Y., II.).

tened. No plications present but entire surface covered with fine,
uniform, radiating striz.

Clinton and Niagaran of New York, Tennessee, Kentucky, igs
diana, Illinois, Wisconsin, Ontario, New Brunswick.

Fic. 399. Spirifer eudora. (After Hall.)

227° S. eudora Hall.) (Fig) 399.) Siluric.
Of moderate size. Valves very gibbous. Hinge line less than
width of shell below, with rounded extremities. Surface marked

mail

BRACHIOPODA—TELOTREMATA. 319

by 3 to 4 strong, subangular plications on each side of the fold and
sinus. Mesial sinus broad and deep. Entire surface covered with
fine radiating striz.

Niagaran of Kentucky, Indiana, Wisconsin.
328. S. niagarensis (Conrad). (Fig. 400.) Siluric.

Of moderate size, convex with nearly equal valves. Pedicle
valve with strongly incurved beak. Surface covered with many
fine depressed plications which become ob-
solete toward the extremities and sometimes
appear quite flattened out. Fine, thread-like
radiating striz cover plications and inter-
spaces alike.

Niagaran of New York, Indiana. .

329. S. (Delthyris) sulcatus Hisinger. Mer ie oe
(Fig. 401.) Siluric. yy),
Gibbous. Valves unequal. Hinge line
more or less extended, often mucronate. Plications 4 to 7 on each
side of the mesial fold and sinus, crossed by strong imbricating

lamellz and longitudinally marked by fine striz.

Niagaran of New York, Ontario.

Fic. 401. Spirifer (Delthyris) sulca- Fic. 402. Spirifer crispus (Pal. N.
tus, with striz enlarged (Pal. N. Y., II.). Y., IL).

330. S. crispus (Hisinger). (Fig. 402.) Siluric.
Small. Pedicle valve very convex with incurved beak and high
cardinal area. Surface marked by broad plications, from 6 to 8 on
each valve, strongest near foldj'and sinus and crossed by fine,
thread-like concentric striz.
Niagaran of New York, Indiana, Ontario, Nova Scotia.

320 NORTH AMERICAN INDEX FOSSILS.

331. S. vanuxemi Hall. (Fig. 403.) | Siluric.
Small, with rounded extremities. Surface marked by 2 to 4
broad plications on each side the
mesial fold and sinus and by im-
bricating concentric growth lines.
Differs from S. crzspus in its nar-
rower cardinal area, less elevated
beak and less gibbous form, and
from S. cyclopterus in its smaller
size and fewer plications, and from
both in its scarcely distinguishable
Fic. 403. Spirifer vanuxemi. fold and sinus.
mm). Manlius of New Morelia
Michigan.

332. S. eriensis Grabau. (Fig. 404.) Siluric.
Pedicle valve very gibbous and almost square in outline. Car-
dinal area high. .Sinus and fold sharply de-
fined and angular, bounded by a few broad

and nearly obsolete plications.
Cobleskill and Manlius of New York, etc.
Fic. 404. Spirifer ert-

333. S. corallinensis Grabau. (Fig. 405.) .,.:. (After Grabau.)
Siluric. 7
Very small. Similar to S. crispus
but differing in the uniformly obso-
lescent plications and the angular me-
dian sinus.

Cobleskill of New York, etc.

Fic. 405. Spirifer corallinensts 334: = ser ad is one (ee
(Pal. N. Y., III.) 406.) Devonic.
Large, ventricose. Valves nearly
equally convex. Pedicle valve with broad, deep sinus and three
broad, rounded plications on each side. Brachial valve with broad,
rounded fold and two rounded plications on each side. Whole
surface covered with fine and close radiating striz.
Helderbergian (New Scotland) of Maine, New York, Maryland,
Tennessee.

335. S. (Delthyris) perlamellosus Hall. (Fig. 407.) Devonriic.
Hinge line more or less extended. Pedicle valve arcuate with
much extended and incurved beak. Sinus deep and profound, ®

eS oe
x, rae

marked by 7 or more rounded plica-

BRACHIOPODA—TELOTREMATA. ant

Fic. 406. Spiri/er macropleura (Pal. N. Y., VIII.).

produced anteriorly into a linguiform extension. Brachial valve
convex in the middle with closely incurved beak. Surface marked
by 4 to 6 strong plications on each side the median line and con-
centrically crossed by regular imbricating lamellee which are
strongly arched in passing over the
plications, giving the surface a rough
appearance.

Helderbergian of Maine, New York,
Pennsylvania, Maryland, Tennessee,
Missouri.

336. S. cyclopterus Hall. Devonic.

Semicircular. Hinge line usually
shorter than width of shell below. Con-
vexity of valves nearly equal. Surface

tions on each side of the mesial fold
and sinus, concentrically crossed by ,,, pet Spirifer (Delthy-
fine, close, lamellose striz. ris) perlamellosus (Val. N. Y.,

Helderbergian and Oriskanian of VIII.). J, deltarium; F, for-
amen; S, median septum; f,
teeth,

5

Appalachian region (Maryland to New
Brunswick and Gaspé).

337. S. concinnus Hall. (Fig. 408.) Devonic.

Semicircular. Hinge line usually shorter than the width of the
shell below. Beak of pedicle valve elevated and incurved. Sinus
and fold angular and sometimes marked by obscure plications
toward the front. Plications rounded, 12-14 on each side of the
median line and crossed by concentric strie. Differs from S.

322 NORTH AMERICAN INDEX FOSSILS.

cyclopterus in the more elevated beak of the pedicle valve, the
more numerous plications and in the angular character of sinus
and fold with occasionally obscure plications.

Helderbergian (Becraft and Port Ewen)
of New York. —

338. S. murchisoni Castelnau. (Fig.
HOO.) Gere Devonic.
Pedicle valve with elevated and incurved

beak and high, concave cardinal area.

Surface marked by 5 to 8 plications on

each side of the prominent sinus and fold.

Entire shell surface covered with fine,

close concentric and radiating striz. In-

ternal mold of pedicle valve distinguished
by a large, prominent striated process, in-
dicating the form and dimensions of the
muscular area. The mold is strongly
papillose on each side of this area.

Oriskany of New York, Maryland, Ontario.

339. S. arenosus (Conrad). (Fig. 410.) Devons
Large, with valves of about equal convexity. Pedicle valve
with broad and slightly incurved umbo. Mesial sinus very shallow

Fic. 408. Spirifer concin-
RAV A INN VA. \e

BRACHIOPODA—TELOTREMATA. 323

and often producing merely a flattening of the surface. Mesial
fold moderately elevated. Whole surface covered with 20 to 40

Fic. 410. Spirifer arenosus, External views and mold of interior (Fallon. 1X ., 111).

_ low and even plications. Occurs largely as internal molds in the
sandstones. ~

| Oriskany and Onondaga (?) of New York, Pennsylvania, Mary-
land, Virginia, Ontario. .

340. S. duodenarius (Hall). (Fig. 41 1.) Devonic.
__- Somewhat resembles S. cyclopterus but differs in its more ex-
tended hinge line which here forms the greatest width of the shell,
,, in the narrow cardinal area which is here almost linear and in the
_ less conspicuous striz. Both valves are flattened at the cardinal
_ extremities.

Onondaga of New York, Ohio, Kentucky, Indiana, Ontario.

324 NORTH AMERICAN INDEX FOSSILS. }

FIG. 411. spirtfer duodenarius (Pal. N. Y., IV.).

341. S. gregarius Clapp. (Fig. 412, d-e.) Devonic.

Small, ventricose. Cardinal extremities truncate or rounded.
Pedicle valve regularly arcuate from beak to front with strongly
incurved beak and high cardinal area ; mesial sinus much produced
in front. Surface marked with 6-10 strong ribs on each side of the
median line. Entire surface covered with concentric striz which
toward the front become strong zigzag lines.

Onondaga of New York, Ohio, Kentucky, Indiana, Ontario.
242.<\qp, Chery Hall. (Fie. 412, a—c.) Devonic.

Gibbous. Hinge line usually shorter than the width of the
shell below, with rounded extremities. Pedicle valve with promi-

Fic. 412. a-c, Spirifer grieri; d-e, Spirifer gregarius,; f-h, Spirtfer ( Delthyris)
raricosta. (After Nettleroth. )

nent and much elevated beak, incurved over the high arcuate area.
Sinus wide ard deep. Brachial valve with small beak, slightly in-
curved over a nearly vertical, narrow cardinal area. Fold promi-
nent and angular. Surface marked by 6 to 10 plications on each
side of the fold and sinus, while 3 or 4 smaller bifurcating plications
are usually present on fold and sinus. Concentric lines present on
well preserved specimens.
Onondaga of New York, Ohio and Kentucky.

343. S.(Delthyris) raricosta Conrad. (Fig. 412, -/.) Devonic.

Gibbous, with rounded cardinal extremities. Pedicle valve with
greatly elevated beak incurving over the high cardinal area.
Brachial valve with small arching beak. Surface marked by 2 to
4 strong rounded ribs on each side the median line, crossed by
concentric lamellose striz and marked by fine and close radiating
strie.

Onondaga of Maine, New York, Ohio, Kentucky, Indiana, Ne-
vada, Ontario, Quebec.

oe ai varicosus Hall. (Fig. 413, @—c.) Devonic.
Small, with length not exceeding half the width. Hinge ex-
tremities angular or mucronate. Pedicle valve much the more

Fig, 413. a-c, Spirifer varicosus ; d-e, Spirifer euryteines. ‘(After Nettleroth. )

convex with high cardinal area. Surface distinguished by the
strong lamellose lines of growth which give it a varicose ap-
pearance.

Onondaga of New York, Ohio, Kentucky, Nevada, New Bruns-
wick.

BRACHIOPODA —TELOTREMATA. 328

326 NORTH AMERICAN INDEX FOSSILS.

345. S. acuminatus (Conrad). (Fig. 414.) Devonic.

Large, ventricose. Pedicle valve with umbo incurved over the
wide delthyrium. Surface distinguished by the very elevated and
angular mesial fold and deep sinus, bounded by 16 to 20 plications.

Fic. 414. Spirifer acuminatus external views and internal mold (Pal. N. Y., IV.).

Onondaga and Hamilton of New York, Ohio, Kentucky, Indiana.

346. S. divaricatus Hall. (Fig. 415.) Devonic.

Ventricose. Hinge line less than width of shell below, with
rounded extremities. Cardinal areas wide. Beaks of both valves
prominent and arching. Sinus and fold prominent and angular.
Whole surface, including sinus and fold, covered with fine, rounded,
bifurcating plications which are crossed by fine, zigzag, concentric
striz.

Onondaga and Hamilton of New York, Ohio, Kentucky and
Port Colborne, Canada.

347. S. euryteines Owen. (Fig. 413, d-e.) Devonic.
Semielliptical. Cardinal area wide and slightly concave; beaks
sometimes more than % inch apart. Fold and sinus bounded on

BRACHIOPODA—TELOTREMATA. 327

each side by 18 to 20 plications. Fold marked by a shallow sinus
in the median line. Whole surface finely striated longitudinally.
-Hamilton of Iowa, Michigan, Nevada, Ontario.

Fic. 416. Spirifer fornacula (Ind. Geol. Survey ).

348. S. fornacula Hall. (Fig. 416.) Devonic.
Pedicle valve subpyramidal with the elevation equalling nearly
half the width, curving abruptly to the front and lateral margins ;

328 NORTH AMERICAN INDEX. FOSSILS.

cardinal area extremely elevated, nearly flat above, with a large,
open delthyrium. Brachial valve moderately convex. Sinus and
fold bounded on each side by 16 to 20 plications. Length about

34 inch,
Hamilton of Ohio, Kentucky, Indiana, Illinois, Wisconsin.

349. S. oweni Hall. Devonic.
Very similar to S. granulosus but differs in its smaller size, its
subangular plications and median sinus, fewer plications (15 to 17
on each side the median fold and sinus), its subauriculate hinge
extremities and especially in lacking the granulose surface so
characteristic of the latter species.
Hamilton of Falls of Ohio region and Michigan.

Fic. 417. Spirifer granulosus (Pal. N. Y., IV.).

350. S. granulosus (Conrad). (Fig. 417.) Devonic.
Large, robust and gibbous with high, curved cardinal area.

Brachial valve with a prominent rounded fold, marked by a median

depression. Plicationslow. Surface strongly granulose.
Hamilton. Widely distributed throughout eastern United States.

——

BRACHIOPODA—TELOTREMATA. 329

351. S. iowaensis Owen. (Figs. 418, 419.) Middle Devonic.

Often inequilateral. Hinge line much extended. Valves often
nearly equally convex. Beak of pedicle valve much elevated and
slightly incurved. Whole surface, including fold and sinus and

FIG 418. Spirifer cowaensis. (After Nettleroth )

Fic. 419. Spirifer cowaensis (S. pennatus Owen) < 24 with enlargement of surface.
(After Hall. )

numerous plications, covered with slender, radiating striz crossed
by concentric growth lines. ‘

Hamilton of Kentucky, Michigan, Indiana, Illinois, Wisconsin,
Iowa, Arctic North America lat. 82° 42’.

352. S. audaculus (Conrad). (Fig 420, a.) Devonic.

Ventricose when old. Pedicle valve with high, concave cardinal
area and incurved beak. Cardinal area of brachial valve linear.
Mesial fold and sinus well marked. Surface covered with many
concentric lines and plications marked with radiating striz. Differs
from S. granulosus in being smaller and in that the cardinal area of
the brachial valve is linear.

Marcellus and Hamilton of New York, Kentucky, Indiana, Wis-
consin.

330 NORDH AMERICAN. INDEX FOSSILS.

353. S. angustus Hall. (Fig. 420, 4.) Devonic.

Valves with great lateral extension and pronounced inequality ;
the pedicle valve forming nearly the entire thickness of the shell.
Rrachial valve flat with narrow
cardinal area and low mesial
fold. Plications fine, from 48 to
50.on each valve:

Hamilton and Portage of
New York, Wisconsin.

354. S. mucronatus Conrad.
(Fig. 421.) Devonic.
Hinge line extended and of--

ten mucronate, giving the shell

a width of from two to four

times the length or greater.

- Cardinal areas low. Fold in
Fic. 420. a, Spirifer audaculus; db, ;
Aerie wneudas (Pa Nee oi brachial valve often flattened or
srooved. Radiating plications
numerous, crossed by lamellose lines of growth which are often
crowded near the front. Often a plication in sinus.
Marcellus, Hamilton and Chemung of New York, Pennsylvania,
Maryland, Virginia, Wisconsin, Ontario.

Me =
Seene
se

Ge, Me

Fic. 421. Spirifer mucronatus, showing some of the varieties (Pal. N. Y., IV.).

BRACHIOPODA—TELOTREMATA. 331

355. S. asper Hall. Devonic.
Small, subpyramidal. Pedicle valve with high, flat cardinal
area, narrow del hyrium and broad, shallow sinus, rapidly narrow-
ing*toward the beak. Fold low and rounded. Plications fine and
low. Whole surface granulose.
Hamilton of New York, Illinois, Wisconsin, Iowa.

356. S. (Delthyris) consobrinus d’Orbigny. (Fig. 422, ad.)
Devonic.
Gibbous with pedicle valve the more convex and arcuate from
beak to front. Cardinal area elevated and concave. Sinus deep
and wide. Brachial valve with an abruptly elevated mesial fold
usually marked by a depression. Surface marked by 8 to 12
angular radial plications crossed by concentric lamelle.
Hamilton of New York, Kentucky, Ohio, Wisconsin.

Fic. 422. a-b, Spirifer (Delthyris) consobrinus ; c-d, S, (Delthyris) sculptilis ; e,
Spirtfer tullies (Pal. N. Y., IV.).

357. 8. (Delthyris) sculptilis Hall. (Fig. 422, c-d.) Devonic.

Gibbous. Hinge line prolonged into mucronate extensions.
Length of shell about half the width on the hinge’ line. Surface
strongly marked by 3 to 5 strong plications on each side of the
fold and sinus, leaving a somewhat wide space at the cardinal ex-
tremities marked only by the concentric striz which cross the
whole shell as strong imbricating lamelle.

Hamilton of New York, Pennsylvania, Kentucky, Indiana, On-
tario.

332 NORTH AMERICAN INDEX FOSSILS.

358. S. tullius Hall. (Fig. 422, ¢.) Devonic.
Small, gibbous, subelliptical. Pedicle valve with high cardinal
area. Plications rather flattened and low. Whole surface covered
with fine, uniform, radiating striz and faint concentric ones.
Sinus and fold well defined, extending quite to the beak.
Upper Hamilton of New York, Northwest Territory.

359. S. mesistrialis Hall. (Fig. 423.) | Devonic.
Large. Cardinal angles rounded or mucronate. Sinus and fold
broad, rapidly becoming expanded toward the front. Plications 16

Fig. 423. Spirifer mesistrialis with enlargement of stria (Pal. N. Y. IV.).

to 20. The whole shell, including sinus and fold, conspicuously
marked by fine radiating strie. |
Portage and Chemung of New York.

360. S. (Delthyris) mesicostalis Hall. (Fig. 424, a.) Devonic.

Cardinal extremities usually extended. Pedicle valve with small _

beak, the upper part only being abruptly curved over the moder-
ately high cardinal area. Sinus angular with a well defined fold in
the bottom. Brachial valve with linear cardinal area and mesial
fold marked by a deep groove in the middle. Differs from S.
mucronatus in the duplication of the mesial fold and in the long
septum extending from the beak nearly to the front of the muscu-
lar impression.

Ithaca and Chemung of New York.

BRACHIOPODA—TELOTREMATA. 333

361. S. disjunctus Sowerby. (Fig. 424, 0-d.) Devonic.

Very variable in shape from semicircular to attenuate winged.
Pedicle valve but slightly incurved at beak, its internal mold gives
a triangular area in part marked by the muscular impression dis-

Fic. 424. a, Spirifer mesicostalis; b-d, Spirifer disjunctus showing variation of form ;
d, internal mold (Pal. N. Y.).

joined from the sides of the shell by narrow fissures formerly occu-
pied by the dental lamellz. Surface of both valves, including sinus
and fold covered with very low, even plications. Sinus and fold
are sharply defined from the rest of the shell. |

_ Chemung; throughout North America.- Also Europe, etc.

362. S. subattenuatus Hall. Devonic—Mississippic.

Small, with hinge line often extended into mucronate points.
Mesial sinus deep-and subangular. Surface with 8 to 12 strong
plications on each side the median line, crossed by sharp concentric
lamine. Differs from S. mucronatus in its smaller size, more ele-
vated plications and stronger imbricating lamelle.

Chemung of New York and Marshall of Michigan; equivalent
horizons of Illinois, lowa, Northwest Territory.

. 363. S. keokuk Hall. (Fig. 425, a—d.) 7 Mississippic.
Gibbous. Valves nearly equal in convexity. Pedicle valve with

334 NORTH AMERICAN INDEX FOSSILS.

very prominent and strongly incurved beak. Plicatious many,
covering the entire shell and marked by fine radiating and con-

centric striz.
Keokuk of Ohio, Illinois, Iowa, Utah.

364. S. centronatus A. Winchell. (Fig. 425,c.) Mississippic.
Of medium size, broadest at hinge line, often mucronate.
Valves moderately convex. Beak of pedicle valve strongly
elevated and incurved. Surface with 34 to 42 small plications of
which 4 to 6 mark sinus and fold.
Waverly of Ohio, Michigan, South Dakota, Utah, Wyoming,

Nevada.

)
I TE
ene ee “sed

e-f, Spirifer increbescens. (After Hall, Nettelroth and Pal. Ohio. )

365. S. marionensis Shumard. (Fig. 425, d.) Mississippic.
Nearly semicircular with hinge line extended in mucronate
points. Valves nearly equally convex. Fold and sinus marked
by 2 or 3 dichotomizing plications. Cardinal areas narrow. Sur-
face covered with many plications which irregularly bifurcate.
Granulose.
Chouteau of Ohio, Missouri.

BRACHIOPODA—TELOTREMATA. 335

366. S. grimesi Hall. (Fig. 426.) Mississippic.
Very large and gibbous. Mesial fold and sinus broad and ill
defined. Entire surface cov-
ered with very depressed ,irre-
cularly bifurcating plications.
Kinderhook and Burling-
ton of Missouri, Illinois,lowa,
Arctic North America lat.
Ager a
367. S. neglectus Hall.
Mississippic.
Hinge line less than width
of shell below and rounded
at the extremities. Pedicle
valve a little more convex
than the brachial with
strongly arched beak and
cardinal area. Mesial fold
and sinus small at beak but
increasing very rapidly in
width toward the front. Sur-
face marked by about 6 plica-
tions on each side the fold

and sinus.

Keokuk of Illinois. Iowa Fic. 426. Spirifer grimesi, X 2%. (Af-
N ae i stor Hall. )

eva
368. S. logani Hall. (Fig. 427.) Mississippic.

Very large, gibbous. Length and widthas three to four. Fold
in brachial valve very prominent and elevated. Sinus in pedicle
valve broad and undefined, produced anteriorly. Surface, includ-
ing fold and sinus, covered with small, nearly equal plications.

Keokuk of Illinois, Tennessee and Missouri.

Lae |

369. S. leidyi Norwood and Pratten. (Fig. 428.) Mississippic.
Small. Pedicle valve gibbous; brachial valve depressed-convex.

Mesial fold bearing a well defined depression in the center, reach-

ing half way to the beak. Surface marked by 7 or 8 plications

and by longitudinal and concentric striae.

_ St. Louis of Kentucky, Indiana, Illinois, Utah, Nevada.

:
|

330 NORTH AMERICAN INDEX FOSSILS.

37c. S. increbescens Hall. (Fig. 425, e/) Mississippic.

Gibbous. Hinge line always as long as the greatest width of
the shell and terminating in more or less extended mucronate tips
which are often unequal on the two sides of the shell. Whole
surface covered with plications, those on the fold and sinus extend-
ing only part way to the umbo and narrower than those on the
sides of the shell.

Kaskaskia of Illinois and Kentucky.

Fic. 427. Spirifer logani, x 3%. (After Hall.)

Fic. 428. Spirifer letdyi, (After Whitfield. )

371. S. striatus (Martin). Carbonic.
Pedicle valve the more convex and marked by a broad, ill de-
fined mesial depression ; beak small, pointed and closely incurved.
Entire surface of valves marked by plications which are nearly
uniform in size with little tendency to become fasciculate as in
S. cameratus.
Utah, Nevada, New Mexico, Nova Scotia.

372. S. cameratus Morton. (Fig. 429.) Carbonic,
Of medium size or large, broadest at hinge line, with cardinal
extremities often pointed. Pedicle valve with concave cardinal
area of moderate height. Mesial fold and sinus as well as the rest
of the shell covered with many striz of unequal size, usually
arranged in bundles (fasciculate).
Throughout North America.

BRACHIOPODA—TELOTREMATA. Siw

Fic. 429. Spirifer cameratus. Two individuals showing variation.

(Ind. Geol. Survey).

373. 5; rocky montanus Marcou. (Fig. 430.)

Carbonic.

Hinge line a trifle shorter than the width of the shell below.

Pedicie valve with moderately well defined
sinus and concave cardinal area with beak
strongly incurved over it. Whole surface
marked by 24 to34 quite uniform plications.
Widely distributed through North Amer-
ica.
CIV. ReticuLrariA McCoy.

Like Sirzfer but with hinge line less than
the greatest diameter of the shell. Radial
plications obsolescent or absent. Surface
bearing rows of fine spines placed on concen-
tric striations or ridges. Siluric—Carbonic.

iy A meCMOUSslY Spine-bearing............ccccssesscscseuane’ va tee
Peer, ciaineter about 2 Inch, ......01..0ccscecncanmuaersrss

* Of medium size, diameter exceeding 1 inch ...........

fe yidth, much éxceeding length...)........J.c.ce0e

Bes NO. plications On .Surfiace ;(;..iidindiechsesvanss

FIG. 430. Spirifer
rorkymontanus. (After

Hall. )

*

eee eee ee ee ee

wieelsia wal s'visiaidiein Vin ain biaia aig a eveie.6 a.
... 378. RR. pseudolineata.

a. Low plications present (3-9 on each side the median line).

I. Width and length about equal...................66.

374. R. fimbriata.

aah Sa barely 379. R. setigera.,

338 NORTH AMERICAN -INDEX FOSSILS.

eed BE NOND SIME NERS sesh isin8 Po sdans | hts Soave aesce al diovsgaah's ov Taaoeseee sebbea che Sepa aO eee su
xe SlUnece sual smooth... Obéell large: ci. 3: ivi. odeacasavetieies sands 376. FR. levis.
** Surface smooth ;: shell of medium size...............0ss0+00s 375. A. nevadaensts.
** Surface’marked by crenulate concentric lines. Small....... 380. R. perplexa.
374. R. fimbriata (Conrad). (Fig. 431, a0.) Devonic.

Gibbous, with rounded cardinal extremities. Pcdicle valve with

Fic, 431, a-b. Reticularia fimbriata ; c—d, Reticularia setigera. (After Hall.)

small beak incurved over the high and concave cardinal area which
is striated vertically. Brachial valve with small and slightly arch-
ing beak. Surface marked by 3 to
9 low plications on each side the
mesial fold and sinus, crossed by
imbricating lamellose striz ; these
strie are studded with elongate
nodes or tubules. |

Oriskany —Ithaca. Widely dis-
tributed through North America.

375. R. nevadaensis (Walcott).
(Fig. 435, ¢.) Upper Devonic.
Less transverse than preceding;

or As, fold and sinus often more angular ;
Fic. 432. WReticularia luvis, X 3 eee ;
(Pal. N. Y. IV.). no plications, surface appearing
. smooth.
Devonic limestones of Nevada.

7 3

BRACHIOPODA—TELOTREMATA. 339

376. R. levis (Hall). (Fig. 432.) Upper Devonic.
Ventricose with rounded cardinal extremities. Length to
breadth as 2 to 3 or as 3 to 4. Pedicle valve with abruptly atten-
uate and arching beak; foramen partially closed by an arching
and very: convex pseudo-deltidium. Sinus either shallow or deep.
Brachial valve only moderately convex with an undefined mesial
fold. Surface usually smooth or marked only by concentric growth
lines. In old ageat times there appear a few obscure radiating folds.
Portage of New York.

377. R. cooperensis (Swallow). Mississippic.

Small (length and breadth about 2 inch), gibbous, with greatest
breadth alittle abovethe middle. Front subtruncate or slightly sin-
uous in the middle. Pedicle valve much the more gibbous with a

Fic. 433. Aeticularia pseudolineata, K 2, with enlargement of part of surface.
(After Hall. )

shallow mesial sinus; beak prominent and incurved beyond the
hinge line; foramen wide and triangular. Brachial valve depressed-
convex with low mesial fold. Surface covered with 2 to 4 very
obscure and depressed radial plications on each side the fold
and sinus.

Kinderhook of Tennessee, Indiana, Missouri, Iowa.
378. R. pseudolineata (Hall). (Fig. 433.) Mississippic.

Width greatly exceeding length. Pedicle valve with shallow
mesial sinus and prominent incurved beak. Surface marked by
more or less regular concentric lamellose folds or wrinkles and ra-
diating striz extended into long spines from the edges of the folds.

Burlington—Keokuk of Missouri, Indiana, Illinois ?, Iowa.
379. R. setigera (Hall). (Fig. 431, c-d.) Mississippic.

Much like 2. pseudolineata, but differs in that here the length
and breadth are more nearly equal and the beak is higher and
narrower.

Kaskaskia of Kentucky, Illinois, Utah.

340 NORTH AMERICAN INDEX FOSSILS.

380. R. perplexa (McChesney). (Fig. 434.) Carbonic.

Small; moderatcly gibbous. Beaks prominent and incurved. :
Pedicle valve without pronounced mesial®sinus, but slightly flat- |
tened or with a shallow though sharp depression anteriorly. Sur-
face marked by numerous very faint radiating lines and somewhat
stronger concentric lines, the latter{finely crenulate, marking the
bases of hair-like spines not preserved.

Widely distributed in North America.

Fic. 434. eticularia perplexa (Ind. Geol. Survey).

CV. MartintA McCoy.

Like Spzrzfer, but with hinge line shorter than the greatest width
of the shell,and cardinal angles obtusely rounded. Surface smooth
except for the concentric striz. Muscular impressions narrow and
faint. Devonic—Carbonic.

381. M. maia (Billings). (Fig. 435, a—d.) Devonic.
Longitudinally ovate. Cardinal area narrow and sometimes
hidden by the beak. Brachial valve with rounded mesial fold.

a Cc

Fic. 435. a-b, Martinia maia,; c, Reticularia nevadaensis. (After Walcott).

Pedicle valve more convex than the brachial, with a large in.
curved beak.
Onondaga of Ohio, Nevada, Ontario.

382. M. glabra (Martin). Carbonic.
Subcircular to ovate. Pedicle valve with a moderately devel-
oped mesial sinus, high cardinal area and incurved beak. In the .

BRACHIOPODA—TELOTREMATA. 341

brachial valve the mesial fold merges into the rest of the surface.
Nova Scotia var. conztracta in Chester of Illinois, Ohio and
Nevada.

CVI. Syrincotuyris A. Winchell.

Spiriferoid, usually large. Pedicle valve with high, erect, cardinal
area ; that of brachial valve low. Dental lamelle strong, surround-
ing the broad, muscular impressions. A tube (syrinx), open along
its inner margin, extends from the apex of the pedicle valve be-
tween the dental lamella and the deltidium (when present) for

Fic. 436. Syringothyris texta. (Ind. Geol. Survey. )

about half the length of the valve. It is formed by the deposition
of accretions to the margins of the delthyrium. Shell punctate.
Entire surface marked by minute, elongated pits, giving (under a
lens) the appearance of twilled cloth. Mississippic.

383. S. carteri (Hall). Mississippic.
Length usually more than half the width or subequal. Cardinal
extremities nearly rectangular. Pedicle valve the more convex;
prominent at the umbo.
Waverly, Burlington and Chouteau of Ohio, Missouri, Iowa,
Montana, Nevada.

342 NORTH AMERICAN INDEX FOSSILS.

384. S. texta (Hall). (Figs. 436-437.) Mississippic.
Large, 14 to % as long as broad. Height often greater than
Jength. Hinge line forming the greatest width of the shell.
Pedicle valve the more convex, very prominent at umbo; mesial
sinus deep, rapidly increasing in
width from beak to front where it
occupies about one fourth of the
anterior margin; beak angular;
cardinal area high and nearly
straight. Brachial valve most
convex near the front. Surface
marked by about 20 simple plica-
tions on each side the median line,
crossed by concentric growth
lines. Much heavier, wider and
more robust than S. cartert.
Waverly—Keokuk of Kentucky,
Fic. 437. Syringothyrts texta, var. : . rat
>< % (Ohio Pal.), Indiana, Ohio, Iowa, Illinois.

CVII. AmBoca:tia Hall.

Small. Sprifer-like. Pedicle valve greatly elevated, with a
conspicuous, strongly incurved umbo; cardinal area arched and
delthyrium open. Brachial valve with long, narrow cardinal
process, crural plates long, parallel,
erect; four well defined adductor
scars present near the anterior mar-
gin. Devonic—Carbonic. |

385. A. preumbona Hall. (Fig.
438, a—0.) Devonic.
Hinge line less than the great-

est width of shell, with rounded

cardinal extremities. Pedicle valve

very ventricose, bearing a shallow

: ‘ ; : Fic. 438. a-b, Ambocelia preum-
impressed median line. Brachial bona ; c-d, Ambocelia umbonata | Pal

valve slightly convex. Surface wy. Iv.).

marked only by concentric strie

which are sometimes crowded into imbricating folds.
Hamilton of New York.

a

BRACHIOPODA—TELOTREMATA. 343

386. A. umbonata (Conrad). (Fig 438, c-d.) Devonic.
Differs from A. pre@umbona in its smaller size, distinct though
narrow mesial sinus and proportionally longer hinge line which
here usually forms the greatest width of the shell.
Marcellus-Chemung of New York, Pennsylvania, Kentucky,
Indiana.

387. A. nana Grabau. (Fig. 439.) Devonic.
Small, transverse. Brachial valve convex, bearing a shallow

mesial depression. Surface covered with numerous elongated pits.
Marcellus and Hamilton of New York.

Fic. 439. Ambocala nana. (After Fic. 440. Ambocelia planoconvexa K
Grabau), enlarged, 2. 2 (Ind.Geol. Survey. )

388. A. planoconvexa (Shumard). (Fig. 440.) Carbonic.

Breadth and length about equal. Brachial valve circular except
for its truncation by the hinge line and nearly flat, with minute
beak and narrow cardinal area. Pedicle valve convex; mesial
sinus represented by a slight flattening in front. Surface seen to
be finely granulose under a lens.

Widely distributed throughout North America. Conemaugh of
Pennsylvania, Ohio and West Virginia.

CVIII. Meraprasia Hall and Clarke.

Spiriferoid but differing from Spirifer in the reversal of sinus and
fold, z. ¢., the pedicle valve bears the median fold and the brachial
the median sinus. The teeth are supported by lamellz, the mus-
cular impressions of the pedicle valve are separated by a short,
thick septum and the cardinal process is strong and bilobed. De-
vonic.

389. M. pyxidata Hall. Devonic.
Small. Pedicle valve with a strong, broad elevation, furrowed
by a narrow sinus down the middie. Brachial valve flat and
marked by a broad depression in the center of which is a narrow
elevation. Surface when perfectly preserved both concentrically
and longitudinally striated.
Oriskany of New York, Maryland, Ontario.

344 NORTH AMERICAN INDEX FOSSILS.

CIX. RHYNCHOSPIRA Hall.

Rostrate, subtriangular. Hinge line short and curved. Umbo
of pedicle valve incurved; apex truncated by circular foramen.
Deltidial plates coalesced; teeth small, not supported by dental
plates. In brachial valve hinge plate produced anteriorly into two
flat lobes. Median septum short and sometimes obscure. Surface
bearing simple radial plications. Shell punctate. Siluric-Missis-
sippic.

390. R. formosa Hall. Devonic.

Pedicle valve tapering toward the beak, which is prominent and
arched. Brachial valve gibbous, with closely incurved beak.
Surface marked by 18 to 23 simple plications, two or three of
which are smaller and slightly depressed on the middle of each
valve; these are crossed by fine concentric growth lines which be-
come strongly lamellose anteriorly.

Helderbergian of Maine, New York, Ohio.

Fic. 441. Homeospira wax XK 2. (Af- Fic. 442. Hustedia mormonit (Ind.
ter Hall, ) Geol. Survey).

CX. Homaospira Hall and Clarke.

Like Rhynchospiva but in the brachial valve the crural plates are
separated by a linear cardinal process, and a high median septum
is present, while the deltidial plates frequently remain uncoalesced ;
shell punctate. Siluric.

391. H. (Retzia) evax Hall. (Fig. 441.) Siluric.
Ovate, usually longer than wide, gibbous. Both valves some-
times bearing a shallow sinus anteriorly. Pedicle valve the deeper,
with greatly elevated and incurved umbo. Foramen circular.
Surface marked by 16 to 28 radiating plications crossed by fine
strize and imbricating, lamellose growth lines.
Niagaran of Tennessee, Indiana.

sill sacl

BRACHIOPODA—TELOTREMATA. 345

CXI. Husrepia Hall and Clarke.

Differs externally from Ahynchospira only in its much coarser
plications. Internally it differs in the structure of the hinge plate
and in the presence of a split and weak tube attached by one side
to the deltidial plates. Carbonic.

392. H. mormoni (Marcou). (Fig. 442.) Carbonic.
Both valves more or less gibbous. Umbo prominent
and arched. Surface marked by 14 to 17 simple radiating ribs.
Widely distributed throughout central and western United
States.
CXII. Trematospira Hall.

Spiriferoid, transverse with nearly equally convex valves. Hinge
line straight with abruptly rounded cardinal extremities. Surface
plicate. Pedicle valve with median sinus; beak truncated by a
circular foramen ; delthyrium covered by two short plates resting
upon the umbo of the opposite valve.
Teeth prominent. Brachial valve with
a median fold and with small and deep
dental sockets. Cardinal process very
prominent and elevated, divided into
four parts by a deep longitudinal and
a less prominent transverse groove.
Distinguished externally from Ahyx-

Fic. 443. Zrematospira camura
chonella and Spirtfer by its punctate (Pal. N. Y., IL.). -

structure. Siluric—Devonic.

393. T. camura Hall. (Fig. 443.) Siluric.

Small, transversely elliptical to subrhomboidal. Valves almost
equally convex. Sinus of pedicle valve marked by one or two
small plications which die out toward the beak. Fold of brachial
valve with two small plications which likewise become obsolete
toward the beak. Surface marked by four to six plications on each
side tne median line and by concentric growth lines.

Niagaran of New York.

394. T. multistriata Hall. Devonic.
Brachial valve the more convex. Surface granulose or punctate,
marked by many fine radial striz and by concentric growth
lamelle.
Hielderbergian of New York.

340 NORTH AMERICAN INDEX FOSSILS.

CXIII. ParazyGa Hall and Clarke.

Differs from Zrematospira externally only in the usually smaller
and simple plications and in the surface covering of very fine and
short spines; these are usually broken off, leaving only their bases.
Internally it has a weak deltidial tube similar to that in Hustedia.
Cardinal process low, bi-
lobed ; dental sockets broad.

Devonic.
395. P. hirsuta Hall.(Fig.
444, a—c.) Devonic.

Depressed orbicular.
Pedicle valve curving regu-
larly to the apex where it
is terminated by a circular
foramen. Surface marked
with 30 to 40 low striz
which are most conspicuous

Fic. 444. a-c, Parazyga hirsute (Pal.N. towards the margin; these
Y., 11); ae, Lumetria marcyi (Ind. Geol. are’ crossed by fine concen-

Surv. ), : :
tric growth lines and more

distant lamellz. Shell punctate.
Onondaga and Hamilton of New York, Kentucky, Indiana,

Ontario.
CXIV. Eumetria Hall.

Differs from Rhynchospira (No. CIX) merely in the greater com-
plication of the parts of the hinge plate and in the variation in the
form of the loop. Punctate. Mississippic to Carbonic.

396. E. marcyi (Shumard). (Fig. 444, d-c.) Mississippic.

Longitudinally ovate, almost equally biconvex. Beak of pedicle
valve elevated and incurved and with acircular foramen. Surface
marked by about 50 rounded, punctate striz.

St. Louis and Kaskaskia of Tennessee, Missouri, Arkansas,
Indiana, Iowa, Illinois.

CXV. WHITFIELDELLA Hall and Clarke.

Small, ovate or elongate, subequally biconvex. Beak of pedicle
valve not high. Cardinal slopes of both valves broad and not dis-
tinctly defined. Anterior margin subtruncate. Median septum
present in brachial valve. Surfacesmooth. Siluric-Devonic.

BRACHIOPODA—TELOTREMATA. 347

397. W. cylindrica Hall. (Fig. 445.) Siluric.
Elongate-cylindrical. Width and thickness nearly equa], Beak
of pedicle valve strongly overarching. Faint mesial depression
present in pedicle valve. Surface marked with fine radiating striz
near the front.
Clinton—Niagaran of New York, Ohio, Ontario, Anticosti.

Fig. 445. Whitfeldella cylindrica (Pal. N. Fic. 446. Whitfeldella inter-
wet ¥. }. media (Pal. N. Y.,; 11..).
398. W. intermedia Hall. (Fig. 446.) Siluric.

Obovate, rapidly expanding toward the front which is abruptly
rounded, Length and width nearly equal. Faint lines of growth
on surface. |

Clinton and Niagaran of New York, Pennsylvania, Ontario.

Fic. 447. Whitfieldelia nitida (Pal. Fic. 448. Whitfeldella nitida var. ob-
ie, 21. ). lata (Pal. NY), Ef).

399. W. nitida Hall. (Figs. 447-448.) Siluric.
Varies from broadly to narrowly ovate. Valves strongly and
equally convex. Beak of pedicle valve pointed and incurved.
Surface smooth except for concentric growth lines which are at
times strongly marked. Often a slight sinus occurs near the front
in both valves, producing a slight frontal emargination.
Niagaran of New York, Kentucky, Indiana, Ontario, Anticosti.

348 NORTE: AMERICAN INDEX: FOSSILS:

400. W. ? nucleolata (Hall). (Fig. 449.) Siluric.
Beak of pedicle valve pointed and incurved. Front of shell
indented. Surface with concentric growth lines. This species is
less elongate than W. zitzda and the frontal indentation is more
conspicuous.
Cobleskill of New York, Wisconsin.

401. W. sulcata (Vanuxem). (Fig. 450.) Siluric.
Distinguished by its elongate form, strongly ventricose character
and well marked mesial sinus in the pedicle valve.
Cobleskill and Manlius of New York.

Fic. 449 Whitheld- Fic. 450. Whitfeldella Fic. 451. Hyattella con-
ella nucleolata (Pal. N. selcata. (After Grabau. ) gesta (Pal.N. Y.jetie
5 ee 8 oe

CXVI. Hyatrecya Hall and Clarke.

Small, nearly five-sided. Valves subequally convex. Differs
from Whitfeldella in the form and in the absence of a median
septum in the brachial valve. Siluric.

Fic. 452. Hyattella congesta (Pal. N. Y., II.).

402. H. congesta (Conrad). (Figs. 451-452.) Siluric.

Gibbous. Pedicle valve strongly convex with a deep median
furrow which deepens and widens toward the front. Strong fold
on brachial valve with a more or less prominent lateral fold on

each side.

Clinton of New York, Pennsylvania, Ohio, Kentucky, Ontario. ©

BRACHIOPODA—TELOTREMATA. 349

CXVII. Nucreospira Hall.

Small, subcircular, gibbous. Hinge line short. Valves nearly
equal. Beak of pedicle valve slightly extended beyond that of
opposite valve. Brachial valve with a large, hook-like cardinal
process curved sharply posteriorly. Crura long and straight. A

Fic. 453. Lucleospira pisiformis. (After Hall.)

conspicuous median septum extends from beak to front in each
valve. Surface in perfect specimens covered with numerous
slender spines ; these are usually worn off.

Siluric-Lower Carbonic.

403. N. pisiformis Hall. (Fig. 453.) | Siluric.
Small. Each valve bears a slight depression down the center.
Surface marked with fine concentric striz.
Niagaran of New York, Kentucky, Indiana, Missouri.

404. N. concinna Hall. (Fig. 454.) -< Devonic.
Depressed spheroidal. Surface smooth, very finely papillose or
when perfect covered with very fine spines. |
Onondaga—Hamilton of New York, Pennsylvania, Virginia,
Ohio, Kentucky, Indiana, Nevada, Ontario.

Fic. 454. Nucleospira concinna (Pal. N. Y., i, ne

e a

CXVIII. AnopLorueca Sandberger (emend. Hall and Clarke).

Pedicle valve convex, with incurved umbo. Brachial valve
concave or flat, more rarely convex, with a high median septum.
No cardinal area. Plications few, crossed by fine concentric
growth lines, making the surface rough. Siluric~Devonic.

eLIemene OVEr 32 INCh Wide. v0.01. ci. sees dbadecsdenetacadsetsavetas 408. A. flabellites.
aieeateal) much less than 34 inch wide. s.... sisi desevseensveccadecssolavevececet occas *
MPMI Nial wale CONCAVE. 6. cous ose<s-assccdeusuedodse dbacebiaceysoeienes 407. A. concava.
EE ANUS AE OF CODVER occ. ssi tes ah baci ne poeyelsincaudanecnge wis ore slaseuiabbdae sas ¥.
Peainpe-line straight ..3.. 0... aa AF a ee 405. A. hemispherica.

MIS OIRO SCE VEER os 1/5 oy aust evvaie eu sOncaad tne rey > uibedaneisa’ 406. A. plicatula.

350 NORTH AMERICAN INDEX FOSSILS.

405. A. (Ceelospira) hemispherica (Sowerby). (Fig. 455.)
Siluric.
Hemispheric. Brachial valve flat. Hinge line nearly straight.
Surface marked by 8 to 12 or more rounded, simple plications
which are crossed by strong concentric growth lines.
Clinton of New York, Kentucky, Tennessee, Georgia, Alabama,
Nova Scotia, Anticosti. ;
406. A. plicatula (Hall). (Fig. 456.) Siluric.

Fic. 455. Avxoplotheca hemispherica Fic, 456. <Anoplotheca plicatula (Pal.
with strice enlarged (Pal. N. Y., II.). ie bee FS

Small, ovate. Valves subequal. Pedicle valve slightly carinate
at umbo, with a slight median sinus anteriorly. Brachial valve
almost flat toward the beak and elevated into a median fold an-
teriorly. Surface with two plications in sinus and three on fold
with six to eight on each side. Concentric striz not conspicuous.

Clinton of New York and Niagara of Wisconsin.

407. A. concava (Hall). Devonic.

Pedicle valve convex. Brachial valve flattened near lateral mar-
gins and at times depressed in the middle due to the rapidly
widening sinus. Surface marked by rounded striz; the one on the

Fic. 457. Anoplotheca (Leptocelia) flabellites (Pal. N. Y., IV.).

mesial fold is generally smaller than the others giving the fold a
slightly grooved appearance along its center quite to the beak.

Helderbergian of New York, and of Kennedy channel in Arctic
region.

BRACHIOPODA—TELOTREMATA. 351

408. A. (Leptoceelia) flabellites (Conrad). (Fig. 457.) “Devonic.
Pedicle valve convex, most prominently along the middle.
Brachial valve flat. Sinus of brachial valve and fold of pedicle

Fic. 458. Vitulina pustulosa (Pal. N. Y.,1V.).

valve quite indistinct. Shell much larger and striz less numerous
than in A. concava.

Oriskany and Onondaga of New York, Maryland, Illinois, On-
tario, Quebec.

CXIX. Virutina Hall.

Small. Pedicle valve usually convex and brachial flat. Hinge
line forming the greatest diameter of shell. Pedicle opening large
and triangular. Cardinal process
simple. Devonic.

409. V. pustulosa Hall. (Fig.
458.) Devonic.
On pedicle valve an elevated

fold present with depression in its

center; on brachial valve a sinus
with a corresponding fold in the
center. Surface marked with a few
coarse rounded plications. Inter-
rupted radiating lines give the shell

a pustulose appearance. .
Hamilton of New York, Penn-

sylvania.

CXX. MERISTINA Hall.

Like Jeristella externally, differ-
ing merely in the character of the Fic. 459. Avertstina maria, (Af-
loop connecting the spirals. Siluric. — ter Nettelroth. )

410. M. maria Hall. (Fig. 459.) Siluric.

Subquadrangular, gibbous, subequally biconvex. Beaks closely
incurved. Pedicle valve with a broad sinus anteriorly and brachial
valve with a corresponding fold. Surface marked merely with con-

352 NORTH AMERICAN. INDEX. FOSSILS.

centric growth lines. Length equalling or greater than the
width.

Niagaran of Ohio, Tennessee, Kentucky, Indiana, Illinois, Wis-
consin. |

CXXI. ATHyris McCoy (emend. Hall and Clarke).

Subequally biconvex, varying in outline from subcircular to
transversely elliptical. Beak of pedicle valve incurved, perforated
by a‘round foramen which encroaches upon the umbo. Surface

medially sinuate. Teeth prom-
inent and recurved at the tips,
supported by stout dental
jamella. Brachial valve with
broad and deep dental sockets
and strong hinge plate; the
' large muscular areas well de-
fined. Spirals laterally di-
retied. with a large saddle shaped jugum, the anterior portion of
which divides, each branch uniting again with the primary lamella.
Siluric-Mississippic.

Fic. 460. Athyris fultonensis (Ind. Geol.
Survey).

411. A. fultonensis (Swallow). (Fig. 460.) Devonic.
Differs from A. angelica in its subquadrate form and somewhat

Fic. 461. <Athyris spiriferoides (Pal. N. Y., IV.).

BRACHIOPODA—TELOTREMATA. 353

less prominent beak; from A. sfzriferoides in its smaller size, the
regularity of its lines of growth and the more prominent umbo.

Onondaga and Hamilton of Kentucky, Indiana, Michigan, Mis-
souri, lowa, Manitoba. |

412. A. spiriferoides (Eaton). (Fig. 461.) Devonic.
Robust. Front indented by a deep sinus. Surface marked by
coarse irregular concentric lam-
elle.
Onondaga and Hamilton of
New York, Pennsylvania, Mary-
land, Virginia, Ontario.

413. A. angelica Hail: (Fig. y erin iy athyris angelica (Pal. N.
462.) Pevonic,. 2.” |
Gibbous, deeply sinuate, with short hinge line and very prom-

inent beak. Surface marked by regular, equidistant lamelle.
Chemung of New York, Pennsylvania, Nevada.

414. A. lamellosa (L’Eveillé). (Fig. 463.) Lower Carbonic.

Length about two thirds of width. Hinge line long, nearly
straight, and rounded at extremities. Anterior margin usually
produced and subangular in the middle at the termination of the
mesial fold and sinus. Brachial valve slightly the more convex and

Fic. 463. <Athyris lamellosa (Pal. Ohio).

rising into a low, rounded mesial fold. Pedicle valve with shallow
mesial sinus. Surface of both valves with 8 or 10 strongly pro-
jecting lamellz. Differs from other species in its transversely
elliptical form. 7

Waverly—Keokuk of Ohio, Kentucky, Indiana, New Mexico.

CXXII. Ciioruyris King.
Differs from Azhyris in the surface ornamentation which here
consists of concentric rows of flat spinules and also in the spirals
and loop. Mississippic—Permic.

354 NORTH AMERICAN INDEX FOSSILS.

415. C. roissyi (L’ Eveille). Mississippic.

Differs from C. hirsuta in the unequal convexity of the valves,
the brachial valve being regularly convex while the pedicle valve
is convex above (near beak), but below is depressed and often
flattened. It differs also in the scarcely incurved beak of the pedicle
valve and in the character of the surface.

Keokuk—Kaskaskia of Mississippi Valley and western United
States.

416. C. hirsuta Hall. (Fig. 464.) Mississippic.

Nearly equally biconvex. Beak of pedicle valve prominent and
incurving over that of brachial valve. Surface marked by concen-
tric imbricating lamella on which rise rows of minute spines.

Fic. 464. Chiothyre. ts hirsuta (ind. Geol. Survey).

Sinus and fold absent, being represented merely by a slight de-
pression in the front of the pedicle valve.
St. Louis and Kaskaskia of Kentucky, Indiana, Illinois, Montana.

CXXIII. Szeminuta McCoy (emend. Hall and Clarke).
Small. Differs from Av¢hyris in the presence of a median sinus
on the pedicle valve and a fold on the brachial with often an
obscure fold on each side
on both valves. Surface of
valves smooth, never lamel-
lose. Mississippic-Carbonic.

417. S. subquadrata Hall.
Mississippic.

Subquadrate with length
and breadth nearly equal.
Brachial valve slightly the
more convex and bearing a broad, mesial fold. Sinus of pedicle
valve broad and deep and produced anteriorly. Surface marked
concentrically with fine Brent ie and toward the margin by
strong lamelle.

Kaskaskia of Ohio, Kentucky, Illinois, Utah.

Fic. 465. Semznula trinucleus (Ind. Geol.
Survey).

BRACHIOPODA—TELOTREMATA. 355

418. S. trinucleus Hall. (Fig. 465.) Mississippic.
Differs from the preceding in having a depression in the center
of the fold, and in the pronounced margins of the sinus, which
sometimes form distinct ribs near the front.
St. Louis of Indiana, Illinois, Missouri and Kentucky.

419. S. argentea (Shepard) (S. sabti/ita Hall). (Fig. 466.)
Carbonic.
Subovate, usually longer than wide, moderately gibbous. Ped-
icle valve slightly more convex than the brachial with prominent
beak; mesial sinus becoming obsolete about the middle of the

Fic, 466. Seminula argentea, one specimen with Cranza modesta (No. 61) attached
(Ind. Geol. Survey).

shell; a more or less distinctly impressed line usually extends
along the bottom of this sinus from beak to front. Brachial valve
with ill defined mesial fold. Surface marked with concentric
striz and faint traces of radiating lines. Average length about 1
inch.

Throughout the Upper Carbonic of North America.

420. S. dawsoni Hall and Clarke. (Fig. 467.) Carbonic.
Smaller and more triangular than preceding, with fold and sinus:
scarcely defined. Greatest width in anterior third of shell.
Windsor limestone of Nova Sco -
tia — extremely abundant.

CXXIV. MerIstTetra Hall.

Oval to suborbicular. Valves
unequally convex, with or without
a faint median sinus or fold. Umbo
of pedicle valve greatly incurved at maturity so as to conceal the
open delthyrium. No cardinal area or spondylium present. Sur-
face smooth or with fine concentric lines and very fine radiating

Fic. 467. Seminula dawsont.
(After Dawson. )

356 NORTH AMERICAN INDEX FOSSILS.

strize. Brachial valve with a strong cardinal process from whose
base extends a thin longitudinal septum half way down the valve.
Muscular area broadly ovate. Devonic.

aes Widtnwe mec acing leit hy 5 2s aek ted cbs sb snk bans eon seca ohne bas dede sk wha Genet e
* Median sinus in both valves........ Be ee, OE eee 421. M. bella.

* Median sinus in pedicle valve only scza. a ddheiahteks mee ciae Naseanon en 424. M. arcuata.

Be. LenGereeGee Gin Wadi scr c. cui. 2 Sadia Uncles ahe<ee4uuastaice teen nied ute cee espe patwaeeeem baie
er MTIPOLVOT TWAT OIG MGUITICBUE (soc aducces bo ndiescs vavenensseslsndtdees' 2 >oqniaee-ghes steam ie

I. Small, Baak of pedicle valve extended ........:5..<as0--+. 426. M. barrisi.

1. Large. Beak of pedicle valve closely incurved.............. 422. M. levis.

** Anterior margin more or less prolonged into a linguiform extension............ 2.

2. Greatest width of shell anterior to middle. Sinus in pedicle valve.
423. VW. princeps.
2. Greatest width of shell near middle. No sinus in pedicle valve.
425. MW. nasuta.
421. M. bella (Hall). | Devonic.
Valves of nearly equal convexity and both marked by a narrow
mesial sinus which in meeting give the front an emarginate char-
acter.

Helderbergian of New York, Ohio, New Brunswick.

422. M. levis (Vanuxem). (Fig. 468.) Devonic.
Ovate, gibbous. Somewhat resembles JZ. de//a but differs in its

Fic. 468. Aleristella levis (Pal. N. Y., I1.).

greater length proportionally and in the absence of a sinus on the
brachial valve. cy

'

BRACHIOPODA—TELOTREMATA. 357

Helderbergian of Maine, New York, Pennsylvania, Ohio, Mis-
souri, New Brunswick.

Fic. 470. Meristella arcuata (Pal. N. Y., I11.).

358 NORTH AMERICAN INDEX FOSSILS.

423. M. princeps Hall. (Fig. 469.) Devonic.

Large, ovate, ventricose. Pedicle valve depressed anteriorly
into a broad mesial sinus, terminating in old specimens in a lin-
guiform extension. Brachial valve greatly elevated in the middle,
producing a strong mesial elevation anteriorly. Distinguished
from JZ. nasuta in its greater width being anterior to the middle
and in the presence of a sinus in the pedicle valve.

Helderbergian of New York, New Brunswick.

Fic. 471. Meristelia urcucta, internal mold (Pal. N. Y., II1.).

424. M. arcuata Hall. (Figs. 470, 471.) Devonic.
Broadly ovate to transversely oval. Pedicle valve bearing an-
teriorly a shallow depression. Brachial valve gibbous along the
middle. Surface smooth except for a few faint radiating and con-
centric lines.
Helderbergian of New York and New Brunswick.

Fic. 472. Meristella nasuta, Schoharie form (Pal. N. Y., IV.).

BRACHIOPODA—TELOTREMATA. 359

425. M. nasuta (Conrad). (Figs. 472 and 473.) Devonic.

Subrhomboidal with greatest width near the middle. Pedicle
valve gibbous with prominent beak. Anterior margin marked by
@ nasute extension. Brachial valve moderately convex and ab-
ruptly elevated toward the front into a short, rounded fold. Beak
moderately incurved.

Fic. 473. Mertstella nasuta, Onondaga form (Pal. N. Y., IV.).

Schoharie and Onondaga of New York, Ohio, Kentucky, Indiana,
Nevada, Ontario.

426. M. barrisi Hall. (Fig. 474.) Devonic.
Ovoid, more or less elongate, sinuate anteriorly. Pedicle valve
depressed toward the front, with beak arching and not closely in-
curved. Brachial valve abruptly elevated near the anterior mar-
gin. Surface smooth or concentrically striated.
Marcellus and Hamilton of New York. Also in Russian Urals.

Fic. 474. Meristella barrist (Pal. N. Y., IV.).

CXXV. PENTAGONIA Cozzens.

Pedicle valve with a very broad median sinus outside of which
the lateral slopes are very abrupt. Muscular impressions like

360 NORTH AMERICAN INDEX FOSSILS.

Meristella. Winge plate rises vertically from the bottom of the
pedicle valve; its anterior face bears a low, median plication on
each side of which posteriorly rise the two short crura.- The pos-
terior face of the hinge plate bears a deep concavity. Devonic.

427. P. unisulcata (Conrad). (Fig. 475.) Devonic.

Subtrigonal, wider in front. Median sinus of pedicle valve oc-
cupying nearly the whole width of the valve and bounded on each
side by an angular fold; umbo prominent and incurved over that
of brachial valve. Brachial valve gibbous in middle, the promi-
nent mesial fold marked by a sinus extending to the beak. Sur-
face bearing a few concentric growth lines and rarely concentric
folds.

Oriskany—Hamilton of New York, Ohio, Kentucky and Ontario.

Fic. 475. Pintazonia unisulcata (Pal. N. Y., 1V.)

MOLLUSCA—PELECYPODA. 361

Puytum V. MOLLUSCA.
Class Pelecypoda. Goldfuss.

(Lamellibranchiata. Bainville.)

The Pelecypoda or Lamelibranchiata are marine or fresh-water
molluscs, with a bivalve shell. The valves are complementary,
and are in the majority of species of nearly similar outline and size.
In each valve may be distinguished an initial point, or beak, around
which the concentric “es of growth mark the successive additions
of shelly matter.

The orientation of most shells is effected by holding them with
the /zuge line uppermost and the beaks pointing away from the
observer. Thus placed, the upper border is the dorsal and the
lower the ventral border. The end farthest away from the ob-
server is the anterior end; that nearest, the posterior end. The
valves are designated as the right and left valves, respectively.
The articulation of the valves is commonly effected by the inter-
locking of ¢ee¢i which are borne on the hinge or cardinal margin
of the valves. They are very various, and not infrequently placed
upon a hinge plate. In primitive species, and in some specialized
types, the teeth may form a continuous row of nearly uniform pro-
tuberances and pits (taxodont dentition) as in Arca, Ctenodonta, etc.
The specialized type of tooth structure consists of a series (3 or
less) of short arid stout cardinal (starting at the beak) and (2 or
less) long, slender, /ateral (not reaching the beak) teeth placed
upon a hinge plate (diogenodont — Crassatellites, etc.) and in the
most specialized cases with additional structures, such as a
roughened area (Venus), accessory lamellze, extra cardinals
(Mactra), etc. (teleodont type of dentition). Other types of den-
tition are: coarse, variable, amorphous teeth (schizodont — Uzzo) ;
special curving and interlocking teeth derived from the shell below
the beak (isodont — Spondylus, and partly developed in Pecten) ;
strongly curving teeth from under the beak, without hinge plate
(cyclodont — Cardium, etc.); variously developed hinge structure
from exterior ornamentation (dysodont) and finally, absence of
teeth (anodont — Anodonta).

362 NORTH AMERICAN INDEX FOSSILS:

The opening of the valve is brought about by an external elastic
ligament stretched across the hinge line from valve to valve, or by
an internal cartilage or resilium. The ligament may extend on
both sides of the beak (amphidetic — Glycimeris) or be only behind
the beak (opzsthodetic — Venus). Inthe amphidetic type, a flattened
area is often developed under the beaks. This may separate into
a posterior escutcheon carrying the ligament as in the Teleodonta,
and into an anterior /unule. The ligament may consist of a single
elastic strand stretched across from beak to beak (ahvincular —
Lima), or there may be many such (multivincular — Perna, Arca,
etc.), or it may consist of a split cylinder in the form of a C spring
(parivincular — Tellina, Venus). The internal cartilage or resilium
may be lodged in cartilage pits or restlifers (also called chondro-
phore) (/actra) or supported by variously formed calcareous
pieces (/zthodesma). The closing of the valves is produced by the
contraction of closing or adductor muscles.

The scars marking the attach-
ment of the adductor or closing
muscle, or muscles, vary greatly,
and are frequently preserved in the

‘ fossil forms. When two are pres-
ent they are designated respectively
as the anterior and posterior adduc-
tor scars. The line of attachment
of the fleshy mantle which builds
the shells, z. ¢., the pallial line, is

Fic. 476. Diagrammatic view of often visible. Near the posterior
left valve of Cytherea; (a.a.) ante- and it frequently makes a reéntrant
rior adductor scar ; (f.@.) posterior : : iis.
adductor scar; (f./.) pallial line; curve — the pallial sinus — indicat-
(f.s.) pallial sinus; (2) ligament; ing that the animal had a retractile
(#,) teeth; (vm.) umbo or beak. cinhon. The various parts deseriaam
(After Lang, adapted. ) nik ; :

are indicated in Fig. 476.

The principal soft parts of the animal comprise: the mantle,
consisting of two fleshy folds, one lining each valve, and building
it ; the abdomen, with the anteriorly placed mouth, and the antero-
ventral foot; the gills. or branchie, which consist of complicated
lamella hanging on either side of the abdomen in the mantle
cavity ; and the szphons— present only in certain forms — pos-
teriorly placed, often capable of great extension, and serving, the

MOLLUSCA—PELECYPODA. 363

one for the entrance of the water and food particles, and the other
for the exit of the water and waste products.

In the development of the shell a primitive nuclear portion or
prodissoconch is always present, though not always recognizable.
In the majority of forms it has the general characters of a nuculoid
pelecypod with a taxodont hinge structure or provinculum. This
is later replaced by the true dentition, of which the taxodont type
retains the primitive character of the provinculum. The inference
from this is, that the pelecypod, ancestral to the types with a
prodissoconch as described, must have had in general, characters
similar in its adult stage to those of the prodissoconch.

In their early stages marine pelecypods like brachiopods are
free-swimming meroplanktonic larve, which at certain seasons
swarm in the pelagic district, and are thus widely distributed.
Fresh and brackish waters also abound in pelecypods, but on the
whole the number of species is relatively small.

In time, pelecypods are distributed from the Cambric, where
they are rare, to the present, where they appear to have reached
their acme of development, though many of their most bizarre
types were developed in the Comanchic and Cretacic.

Three orders are generally recognized, Prionodesmacea, Anoma-
lodesmacea and Teleodesmacea; under the aberrant division of
Palzeoconcha, which is probably not a natural group, are united
many primitive and perhaps degenerate types.

LITERATURE.
Refer also to General References, p. 7.
Descriptive Literature. — Selected Works.

1847-1885. Hall, James. Pal. N. Y., vols. 1-5. (Vol. 5 is exceed-
ingly important for discussion of middle and upper Devonic pelecy-
pods. )

1864-1869. Gabb, W. M. Geol. Surv. California, Pal. 1 and 2.

1873-1893. Hall, Whitfield, Meek, Ulrich. Pal. Ohio, 1, 2, Geol.
Wok

segue meck, F. B. U.S. Geol. Surv. Terr. 9 (Cretacic). Inval-
uable for its discussion of Cretacic genera and species.

1884. White, C. A. and Heilprin, A. U.S. G. S. Ann. 4 (Fossil
Ostreidz of North America).

1886 and 1907. Whitfield, R. P. and Weller, S. Pal. N. J., 1, 3,
4 (Paleozoic to Tertiary). Also Mon. U. S. Geol. Surv., IX. and
XXIV.

364 NORTH AMERICAN INDEX FOSSILS.

1889. Dall, W. H. Bull. U.S. Nat. Mus. 37 (geologic distribution
of recent species of southeastern coast of North America).

1893. Stanton, T. W. Bull. U. S. Geol. Surv. 106 (Colorado For-
mation).

1893. Cragin, F. W. Fourth Ann. Rep. Geol. Surv. Tex. (Cretacic).

1895-1903. Dall, W.H. ‘Trans. Wagner Free Inst. Sci., vol. 3, parts
3-6 (Tertiary). This exceedingly valuable work revises the classifi-
cation of the pelecypoda and gives a critical discussion of most of the
later genera and many species. It is indispensable to the student of
Pelecypoda.

1895 to date. Inst. Geol. Mexico Boletin.

1895. Stanton, T. W. Bull. U.S. Geol. Surv. 133 (Knoxville of
California).

1896-1897. Harris,G. D. Bull. Am. Pal. 4, 9 (Eocenic [Midwayan
and Lignitic] of Gulf region).

1897. Ulrich, E.O. Geol. Surv. Minn. 3, part 2. (A most impor-
tant discussion of the Ordovicic pelecypods throughout the middle
west. Especially good for generic descriptions. )

1898. Hill and Vaughan. Bull. U.S. Geol. Surv. 151 (Lower Cre-
tacic Grypheeas of the Texas region).

1900. Beede, J. W. Univ. Geol. Surv. agen 6, part 2 (Carbonic).

1903. Clarke, J. M. Naples Fauna. Mem. 6, N. Y. State Mus.

tgo1-1906. Clark, Martin, Glenn. Md. ea Surv. (Eocenic-
Pleistocenic). |

1906. Arnold, Ralph. Prof. paper U. S. Geol. Surv. 47 (Cenozoic
Pectens of California).

(See also references under Faunal summary.)

ARTIFICIAL KEY TO THE GENERA.

A. Distinct hinge-plate absent; also hinge margin usually thin and without teeth ;
when teeth are present they are merely modifications of the hinge margin and

not set upon a hinge plate. Two subequal adductor scars..............seeeeeeeees i

I, Pallial sinus absent; also pallial line usually obscure. Almost confined to the
Palaorote 3 esieeswsee Ancersarg cleaterdt nek Piipja cles oulaiael a wigs gecaleinabana aie pana an I.

FF. Beaks Very BD(EMION,...0 0. 41.<seysae ks cnucs dx > poe tataeataenre akan eee a.

a. Shell transversely elongate ; hinge and basal margins subparallel.......11.

11. Shell moderately elongate ; umbonal ridge slight..................08 aa.

aa. Anterior end vertically subtruncate from edge of beak.
VII. Cuneamya.

aa. Anterior end projecting forward from beak.............sssseeeereees f:
{. Beaks very prominent and incurved...............0.0<css-ssapegea =
7, EAMG MA TOUU TAU Ge Gacse ds caceumemnseanles XV. Cardismorpha.

*, Hinge margin thickened ;. ...d.\-s0sscussss0-- X. Grammysia.
f. Beaks not prominent... 0... 0... swede vase sevaueoos.s¢see sen bos
**, A broad sinus present basally anterior toumbonal ridge. 7/7

MOLLUSCA—PELECYPODA. 365

z/’, Shell higher posteriorly than anteriorly.............. a/!;
a’/’, Umbonal ridge obsolete.............. Il. Clinopistha.
a’’, Umbonal ridge present ............ IX. Orthodesma.

z’’, Shell width subequal posteriorly and anteriorly.
XIII. Paleanatina,
**, No sinus‘ anterior to umbonal ridge. ...........ccsseseseess 5: ee
0, Beh eamely Oval diia, civ tase ed acas onpacee oeseeanaues 6/7,

6’’, Depression posterior to umbonal ridge.
XII. Saffordia.
6’’, No depression posterior to umbonal ridge...... ptt
1//’, A narrow ridge present behind the beaks.

XIX. Edmondia.

POS MIRE GUSEOR Ci iicattid asthe XX. Fordilla.
BEE SSCA ARE OW LY OMe, ane cetade ees sks dislscue st seeloegiess che eT;
c/’, Umbonal ridge noticeable only above, near the
INST >; oa ilese srsa come tener uve tenes XI. Glossites.
c/’, Umbonal ridge as inconspicuous above as below,
PULA
2///, Posterior adductor scar three times size of
BDAEMON |. es saccatensen saree XVII. Pstloconcha.
2//’, Adductor scars subequal........11I. PAthonia.
Se onell Very lene and UAGOW 4.0. 52,0-<s poucceeetecccusedieNacnsscavesasens bb.

66. Posterior umbonal slope with different sculpture from rest of shell.
VI. Orthonota.

66. Posterior umbonal slope not differently sculptured.......... care k Ve
tt. Antero-basal end of shell notched................- V. Prothyris.
tft. Antero-basal end without notch............. IV. Sanguinolites.

a. Shell subcircular, with radial sculpture and prominent, incurved beaks.
XVI. Cardiopsis.

MR NCEREI os ssp nv cohen se vedaak ee. abe tes ulttovaths sweeter loaku tay here b.
SEEN IeaT LEAMGWELSCLY CLOMBMLE Sf 57505 Siw niacowed setaiebenidwecs nsbyvetiveoknseu ate 22.
ee Un race FAGisl by Sem pte 6s. 5 eas ivanace haute ie -dcinsticadbueaaeSbvdvasas lle

ee. Umbonal slope Conspicuous 4.25 sures. eves donee XIV. Zellinopsis.

cc. Umbonal slope very inconspicuous ........ ......cseeeeeee I. Solemya.

pa. ~putiace.without radial Tibs Or Sti. 354+ ccc) apeoacseviccws vavasses seins dd.

dd. Shell abruptly attenuate posteriorly ........... CXXX. Cuspidaria.

dd, Shell not attenuate posteriorly................ceceeeee OS PB mes rE Pe Tb

Tt. Beaks very strongly incurved 0.0) 5....0..5..00.: X. Grammysia.

TT} 1... Beaks net prominently menrved, vi0).5. coksbesceneaveneces ss HEX,

**%*, Furrow extending from beak to posterior basal margin.
VIII. LZhonia.

*%*, Shell lacking posterior furrow........... XIX, ELdmondia.

eeeencn, sab-circular or vertically. elongate. 2.006. vcasduesevesseses sacdes saveos 33%
a2, Sofface- with radial sculpture strongest. jis.c. isis cscse ce dnscesnoe ceases ee.

Gh, RIASS WAU LACH ALINE TIPS, ie ges sccunca-vcbs ceevelsscecnsientveres TTTT:

Pie NERO ING PUMICE Awan tnivag hovering iacdae eke thcrwoadst mee

ARES Umibo high, Marrow Sei.dicesns ce cee. ses5 XXI. Panenka.

were. Umbo low: BYOMAS Sve kecececse dos cones XXIV. Buchiola.

tttt. Hinge line curved ; also ribs numerous, small.
XXIII. Paracardium.
ee. Surface with fine radiating striz................:00008 XXII. Ontaria.

366 NORTH AAMERICAN INDEX FOSSILS.

33. Surface with concentric sculpture strongest......... XIX. ELdmondia.

I. Pallial sinus present ; also pallial line rather strongly impressed. The following
characters also usually hold true: Resilifer present; hinge line straight,
moderately long. Hinge and basal margins parallel. Umbos prominent..2.

2: Most prominent.suriace sculpture ConCentric,..; 5.05... .0sa0s<ecdecsarnseasesemene G
c. Concentric sculpture strongest medially..............00-e00 CXX. Allorisma.
e., Conceninc.sculpture strongest anteriorly. 0.2 ......c0s0'colesavucorsgnad cone 44.
44. Surface sculpture all concentric............... aes CXXII. Rhytimya.
44. Surface sculpture radial in middle of shell...... CXXIV. Pholadella,
44. Surface sculpture radial posteriorly 2... .c20.0c0620<e0r serene ee
ip: Umbonal sid gevannlar i: sisi gsr scc nse bcsew leash. CXXV. Cimitaria.
jf. No umbonal ridge present....... pasesemvaeniee CXXVIII. Anatimya.
¢, ‘Concentric sculpture uniidtm:-over entire shell......3...<<50shedcecs venemeee 55-
§§- Middle of each valve with radii, .b0.0.0..0cecasees CXXIX. Liopistha.
55, Middle of valves free from radii: .. 4 ;..5..2...0;, 2sexes san saeco ke.
gg. Hinge margin with a thin horizontal lamina,.CXIX. Pleuromya.
ge. Tdinge margin with no lamina. \... i :....00i..0.6 leo. esed, eee 5T-
5f- An anterior sinus present, extending from beak to base...5%.
Gry, Reeth presents Ss eipits hens nicane eeowrs CXXI. Sphenotus.
Se) PEC MRE clay .akt ea eva soaieeopaces CXXIII. Endodesma.
5t. No sinus on anterior portion of shell...... XVIII. Chenomya.
2. Most prominent surface sculpture radial, strongest medially, wanting pos-
HOTROELY: oy ania ada tea ciniaietiadn males eid dina, cs Sane ach Ven wisinds ae slena ge Sele acco teen da.
d. Posterior umbonal ridge well marked dorsally....... CXXIV. Pholadella.
@. Posterior umbonal. slope gently rounded. ..........:.5...5. sdss<srds beeen 66.
66,, Shell attenuate posteriorly. ....0.0.<.isers0sa000- CXXVII. Phenacomya,
66. Shell broadly rounded posteriorly, ...... i0.<.+2.:.<0ssssestoseanaceeeaee hh.
Wi. ARCGKS: SUMOC ORIEN. 5/52 GsE cates. sence nae wastenteconaes CXXIX. Liopistha.
WEA) DERNS OMUCLION (vera ict codawer ip ane sab agh oreo eae CXXVI. Pholadomya.
B. Mistinet hinge plate: presents 1 /2icccc ses cedan ose wag encos ov epade cals omeaeaena pens eee gen FH,

II. Shell winged or eared, z. ¢., the flattened dorsal portion is extended beyond the
convex body of the shell and more or less definitely constricted from it.

Etinge line Straights 2. iss. cnns neartanvendninsomesenee svianawiheleulpebapmens an pa: ern 3.
3. Hinge line marked with numerous vertical grooves for reception of ligament...¢.
4. Beaks, terminal ook. oisids coves kstede nde nest a/o own sadeshlesva seen vie
77. Concenttic sculpture. prominent, 450. c00,<. 2.502 LXVII. noceramia

77- poncenet sculpture not prominent...) scsssecesssse'cnss saeasenn eee 283

2. Posterior portion of hinge without teeth...... LXVI. Gervzlliopsis.

‘i Posterior portion of hinge with. teeth «...........:c..000 sssseseeeaa” of.

6+. Anterior and posterior lateral teeth parallel to hinge margin.

LXIV. Bakewellia.

6;. Anterior and posterior lateral teeth ranging obliquely upward.

LXV. Gervillia.

e: sbedks, aot terminal 6. 5.5 — nis snp hawtas gone reneds cen sepa geatacneseenenaea er 88.
88. Surface with prominent radiating sculpture...... XCVI. Crenipecten.
88. Surface with prominent concentric sculpture... LX VII. Jnoceramus.
88. Body of shell with concentric and ears with radial sculpture ; beak
GiDCORUEAL «Gece ec Paes en eve ae toasted Waeam ve day evan XCIII. Luchondria.

3. Hinge line not marked with numerous vertical grooves for the ligament.....7-
/. Shell ostreiform, 7. ¢., strongly inequivalve, distorted by early adherence
to other objects. Only one muscle scar present, subcentral. Teeth

MOLLUSCA—PELECYPODA. 367

absent or very obscure. Surface usually crossed by strong, plate-like

eomcentrie lamellae ty fis, at teccmaatee ew eau asue ous en seen othe keen eee 99.
991. Beaks, small, mot.curvedss abs pciwk vets A aelesyhea at LXXIX. Ostrea.
99. : Beaks-promiment,ctronglymearved 0.) 2: ues se lincaacesoseok Meameaeaie

jj. Beaks curved in the median plane................ LXXX. Gryphea.

jj. Beaks curved to right or left of median plane. LXXXI. Zxogyra.
Gey SOL, ROU OSEREIM NOIR 226i, Crome Rad cap ehaaka cade ge seameesnackesotupeeee aseotas 000.
000. Wings or ears two, a small anterior and a large posterior (when
small usually called ear ; when large, wing)...... ay bacneebucees Rk.
Aes; sublace tadially scwlpeured si siveccesee eel cesiviies dacs sexy ae bon vee Tats
7+. Hinge area longitudinally grooved on both sides of the beak. 6*.
GF, Aaa telor mAIsclé SEALS CWOs oops) gc iilecadveccs vcavee tects dees eis
3’. Pallial line and umbonal muscles indicated by many
ominll deep DHS. 3510. J iedsai Ns owed: XLVI. Limoptera.
GRE, CLD WOE PES: SN His seas a he acn oes XLV. Pterinea.
OF. “dductor mraiscleeear ome Oia cos sca cetcate ates 4.

4/’. Hinge line forming greatest width of shell.
XCIV. Prterinopecten.
4/’. Hinge line not equalling greatest width of shell.
XCV. Lyriopecten.
7+. Hinge area not grooved longitudinally ; also muscle scars

practically but one (see LXVIIL. Ptevia)...cc.ccccsoosecse “hgh
7*, Umbonal ridge very strong........... LXIII. Conocardium.
7%. Urabonal ridge! weak: Or wanting. £...000. cvereeseccsesacese Ue he

5/’. Anterior extremity of ear pointed.
LXXI. Ptychopteria,
45/’. Anterior extremity of ear rounded.
LXX. Actinopteria.
kk. Surface without radial sculpture (where muscle scars are reduced

practically to one, see LX VIII. Previa) ....cccccccsseseceeenens Of:
8t. Shell strongly oblique...... ENANGe aN aioe anlar wonaePammn ce oes aGex 3*.
SU AMET ot CAC ACME NS Riess ecweGaeedotate ventetuss news 6’,

6’’. Hinge longer than body of shell... LXIX. Preronites.
6/’. Hinge shorter than body of shell... XLIX. Leptodesma.
S* Anterior ear rotinded..< sh .cbi.casccesie XLVIII. Lecopteria.
8}. Shell but slightly oblique ; wing elongate, narrow.
XLVII. Actinodesma.
ooo, Ears two, the anterior much the longer ; byssal notch edged with a
comb-like series of small teeth................... XCVIII. Chlamys.
ooo. Ears two, the anterior longer; byssal notch smooth.
XCIX. Camptonectes.
Darian Ea BAO GOL 7, Serena Pamenac eis Sn alae Ga hgh is sda cyte seems oO Ha dae seed Zl.
Pens NOES IMPUINCE A idan cdenoveniey Se eat fot kcadeughios uviteccteedee< of.
gt. Shell with small internal ribs radiating from beneath the beaks.
CII, Amusium.
fa Ome WIKNOMt TEER MEL TIE, cid ial slent sccnduawencsssscegvennss 9*.
g*. Ears diverging at a sharp angle above the beaks.
C. Lntolium.
g*. Ears not diverging at a sharp angle............cceseeseeees mer
7/’, Ligament in shallow grooves roughly paralleling the
MAPSCO A NOT, chide pars theta’ vatigubes ds suas ae’,

368 NOR) AUAMERICAN: INDEX «FOSSILS.

ad’’, Shell very strongly lamellose.
XCII Acanthopecten.

d/’, Shell not lamellose............. XCI. Aviculopecten.

7//, Ligament in numerous grooves vertical to the hinge

rg eee Ss ee aE XCVI. Crenipecten.

7/’, Ligament in a median triangular internal pit........e/7.

e’’. Body of shell equilateral............ XCVII, Pecten.

é’* > Rody of shell inequilateral....<....ic.4, CIV. Lima.

Zi, Ears moderately distinct, though very small, the anterior one
larwer; no byssal nately s f.osikscecsearsdabeeaes CI. Syncyclonema.

i. Ears indistinct, merging with the rest of the shell.
LXXIII. Pseudomonotis.

ooo, Wing or ear one, posterior, or apparently SO. ........cceceseeeeeeees mm,
mm. Surface with radial sculpture, ribs or strice...........sceceeees Iof.
toy. Anterior byssal:opening presént......c02.4: fens civdaqcmeanee lon

ro*, Shell sshightly oblique. . hiss... d.+-cradedeaspcenehes eee fe ide

6, Ehing) with weeth. yc. etaes s2isiceacow oregon dome Desk

J/’’. Umbonal ridge exceedingly prominent.
LXIII. Conocardium.

Ff’. Umbonal ridge weak ......:::.. LVI. Byssonychia.

8//. Hinge -without teethc.ciis ae LVII. Adlonychia.

10*.. Shell quite OblQue. (.iv\ia. 592-500 ol soes veeenc ea ea oe
9’! 5. NV WET y AONB LSA ied vcs oa UeGaadt LV. Anomaledonta.

9/’. Wing very slightly marked....... LI. Lunulicardium.

fo" oohell wertgcal ss leest stihl coace LXXIII. Pseudomonotis.
1of. Anterior byssal opening absent; also shell rather strongly
co. 8119) ot A ER ay ad eg: Reais MA RE peg LIV. Ambonychia.

. Surface without radial pcfildtuce J vids avs sae sbage odd tae iE
ie Hane Aime long, e.csc. seesenaa ea cdh vag nde ave donde ren ee rr;

11*, Beaks narrowly pointed. Umbonal angle less than 90°.
LXXV. Myalina.
11*, Beaks rather broadly pointed. Umbonal angle about
QO? eicavaltas GAR Bute ficnanwede hbo cna ade hana eee ro
zo’’, Wing separated from body of shell by a deep sinus.
LXXII. Monofpteria.
zo/’, Wing not separated from body of shell by a deep
SINUS So cdnp bcs sntcnsn Vesa abs danke Se sme coe en ees ean abs
g/’. Wing very small, narrow, and appressed.
L. Loxopteria,
pf? Wane wery' bread... dcvi.sccktce a LX. Chonychia.
Bit: Hiwige line very shorts... 50 000.5 <-06s05-0 0c staone sop caneeenn 12;
12*, Cardinal teeth present; shell long and narrow.
LVIII. AZyttlarca.,

12*, Cardinal teeth absent; shell elongate-ovate...... ... IPG
z1/’, Umbo very strongly incurved... LX XVIII. Aucella.
zi/’, Umbo slightly incurved.......... LIX. Plethomytilus.

O00; haf One; ATLELION «cu. Jieu sa dewacaig cs Seow 1s dak feawelipd ets oo epee nn.
nn. Shell very elongate-triangular................6. LXI. Aviculopinna.
nn. Shell short-triangular or subcircular ............ LII. Plerochenia.

pie Shell Withouly Witsoe, ace sede cosh catde debe dena ode need es Suenpe Cie oss heen 4.

4. Hinge taxodont, z. ¢., composed of many alternating teeth and sockets which

MOLLUSCA—PELECYPODA. 369

are mostly similar and form a more or less continuous series............. £-
g. Shell nuculoid, z. e., hinge line rather sharply arched ; the small shell con-
centrically striate or smooth ; teeth numerous, similar and transverse..111.
111. Pallial sinus absent ; shell usually subcircular..................ec00e0 00

oo. Teeth interrupted beneath the beaks by a resiliifer.
XXVI. Mucula.

$0. DO FEstialer: PreseMAe nove ows hh Ge Hiabanendserensedasnanaebd xesncitette 1
12}. Shell transversely elongate............... XXVIII. Paleoneilo.

12}. Shell subcircular or vertically elongate...X XV. Ctenodonta.

I11. Pallial sinus present ; shell transversely elongate.................... Dp.

pp. An internal vertical partition beneath the beaks.
XXVIII. Meculites.

pp. No internal partition........ Spaeichtiey, ovis adh ok GaMhip aner sdalas oes ae New wns FST.

BQ}: k alliah sinus: SHAMO Wo 2x, ie sdncretnnttanevs sone oie XXIX. Leda.

Loh Pale Sime Meeps cia scis ites cke savant cass iets XXX. YVoldia.

g. Shell arcoid, z. ¢., hinge line straight or slightly arched ; teeth more or
less vertical or with laterals subparallel to the hinge margin....... 222.

mead Ol) teeth wertieal 250.55 ceiae tyes, Sisk ante eames XXIV. Buchiola.
222. All teeth vertical to hinge line except the end ones which are more

or less oblique.......<..<. Eaiituotnesded tomicesie mn

gq. Hinge area with Aigament:s grooves converging rio ae hinge
iat, te fhe Dewi, celle vt oavesbe sy vakedeet nasbwesaeids see aetia 14f.

14}. Shell transversely elongate.
XLIII. Arca and XLIIIA. Barbatia.

t4 7, Shell subtcioonel. 12,1 ssjciiaads.scs tsb XXXIV. Zrigonarca.

iat Shek subcirenlat oxy. y2thies tik oak ea bes XLIV. Glycimeris.

gq. Hinge area with ligament grooves vertical...XXXV. Breviarca.
woe, \eateral teeth Subparallel to Tinge line. sis... niesade cons secnecee ces ace rr.
rr. Only posterior laterals present..............4. XXXI. Parallelodon.

rr. Both anterior and posterior laterals present.. ..............0c0e0: I5t-
15. Shell transversely elongate................. XXXII. Memodon.

I5t. Shell subquadrate or subcircular.........XX XIII. Cucullea.

g. Shell cyrtodontoid, z. ¢., hinge line straight or only slightly arched ; teeth
not forming a continuous series but the posterior laterals widely sepa-

rated from the cardinals ; no anterior lateral present. All teeth more

‘or less parallel to hinge margin. Strongly convex, subcircular shells

MAR PORDINENE WRIDORL coca a cvauccsecds poe b cviwe cies Goleieead cm calainad vtena 333.
ae eC Orang! Ket LWO.OF WHORE 5 AK Gabinciiac cs decadehi, dus beccedeseesdes sei SS:
ss. Cardinals behind the beaks.,..............0s00: XXXVIII. Ortonella.
peoarcmels in Stomt ol the beaks ec jlo Znkiecsaleces sas ec.ccncaesevces 16+
16}. Anterior adductor scar deeply prominent.................000 13%.

13*. Anterior adductor scar excavated out of hinge-plate.
XXXIX. Vanuxemia.
13*. Anterior adductor scar free from hinge-plate.
XXXVII. Megambonia,
SOF AGsuctor Seats (SUbEQUAl Suicide decken seh cewnsioores.ssdianes 14*,
14*. Area posterior to beaks (escutcheon) mecied
XL. Whitella.
14*, Area posterior to beaks not'striated. XXXVI. Cyrtodonta.
333. Cardinal tooth one (astrong cardinal process)..X LI, Plethocardia.
IIH AMMOMMATN Yoo 5 5S cakes eich kad oe dae Shin esld Vash yGasnubGoleyecdaacd’epaces saqecs h.

370 NORTH AMERICAN INDEX FOSSILS.

A, Shell distorted usually by adherence to foreign objects, heavy, irregular,

Gata Py AREV ONY EDA AN oo ins thee caida ones elves dueSt wa, tsueoa acco 444.
444.2 Deethabsent ion wey) GUSCUPE i. <f0h3.0. 5.34 vos.ss oodewadesdeedh usta eee tt,
i Beakssmalll, siotienrved soo. chctiucs 2. cbi veces ceates sc LXXIX. Ostrea.,

7... Beaks prominent, stranely incurved..)5.225).<0.20d:¢s<0hcasteeemee yf
17{. Beaks curved in the median plane......... LXXX. Gryphea.

17{. Beaks curved to right or left of median plane............ 15"

15*. Valve (the larger) narrowing to beak with great sudden-
ness (looks like Capudlus, gastropod)...L. Loxopteria.
15*. Valve (thelarger) narrowing slowly. LXXXI. Exogyra.
444-- Meeth i wery prontinent;Meavy: .locaci2 fini va Castes tos ep cess ue uu.
uu. Shell with prolonged and irregularly twisted umbo.
CXLVII. Monopleura.
uu. Shell with regularly spiral umbo in one or both valves........ 18f.
18f. Surface strongly lamellose.................c000s CXLV. Chama.
1S}; Suiiaee nat/lamellose sis ccs. a a: See 16*;
16*. Attached (left) valve with regularly spiral umbo (right
valve operculum-like).............. CXLVI. Reguienia.
16*, Attached (right) valve coniform.
CXLVII. Caprina,
CXLIX. Jchthyosarcolites,

CL; Coralliochama.
uu. Shell (one or both valves) conical, elongate. .................06 Iof.
19t. Attached valve conical, vertically ribbed ; free valve flat or
COUNCAIRS Sony rennese count iaueatione eens CL. Radiolites.

Igt. Attached valve coniform ; free valve spiral ; shell marked
with concentric growth lines, though longitudinally fibrous

AUTEN 5. Peacse sav euitea nts cence CXLVIII. Caprina,

CXLIX. Jchthyosarcolites,
CL; Coralliochama.

A. Shell more or less distorted through boring habit; a calcareous siphonal
tube ObeSent:. .5,4:.yike nctn Cee Secsoweb vearabtstwents tees aon 555-
555- Tubes found in sand. No shell known, Tubes have transverse
SEDER sia. Pi cvist anal res kets apes day Caine CLXXXIII. Polorthus.
555- Lubes found: in wood ...0....002.5.ba0s th bec ceconssseenete coset heen vu,
vv. Valves with a prominent anterior notch........ CLXXXI. Zurnus.
Dts NANOS. ANMOWEN tM gine s ohaa owen Sas seb iowcehaap ins CLXXXII. TZeredo.
hk. Shell usually entirely free from distortion.,......5.........scccesenssvoer ens 666.
666. Surface marked with radial ribs... .).66. 05 .c000.25.0h0000n0ecee ae ww.
ww. Shell elongate laterally, the greatest length parallel with the
long, straight hinge line................ CXXXI. Pleurophorus.
we). Shell subtriangular sy. s..scc. id chess hs scenes cedeacs ac sauw tee 20f.
zof. Shell very elongate-triangular..................0. LXII. Pinna.
207.. Shell of medium ‘length or short... .c...:.....2:<.43<seeeeee 17%
17*. Surface with rows of nodes................+. XC, Trigonia.
27* SUTIACE SPINOSEs Laiswisececedkersooeec es sats asus. 5 cen Ie
r2/’, Byssal opening prominent............ LIII. Honeoyea.
r2//, Byssal opening absent..............+. CII, Plicatula.
17*., Surface free from spines and nodes........<:-.ssesrewa 17°)

73/’. Shell exceedingly thin; lower valve flat and per-
forate near umbo for the byssus..CVII. Paranomia.

MOLLUSCA—PELECYPODA. 371

£772 Suell thicker, not perforate. 0.50/20 20.4 ie caroekace es ae
A’ /.ayesal, openings prominent: 2/25. oot enscanodtes sl
3//’. Beak minute, strongly inflected.
LIII. Honeoyea.
3//’. Beak not minute, very slightly inflected.
LI. Lunulicardium.

h/’. Byssal opening absent......... CLXVII. Linearia.
und, opel semieimeular yc, tyant oo tetaskesccvkskcdess LXXIV. Halobia,
Dy SNACIUL SUNIL COAN 5). teed eee ec eet ovens pravcs choked Lyswaledaretiads 20:

21f. Shell exceedingly thin; lower valve flat and perforate near
the umbo:for the. byssus... :.....5...... CVII. Paranomia.

2giy doe I ORCC UDY THICEMERS, 9522 a. iinscusieavestsashanevesiaae 18*;
EG: PERUSE MERION eee dha Kidercshyeits snide Jove does, wae ductus tale
r4/’. Both anterior and posterior lateral teeth present...2/’.

f/. Ribs-over, entire. shell, ..i..5.:.. CLVII. Cardium.

2/’, Ribs only on posterior part of shell.
CLVIII. Protocardia.
14/’. No lateral teeth present...... CXLIV. Venericardia.
18*, Beaks not prominent ; cardinal teeth three in each valve.
CXLI. Ptychomya.

See NAN OVEN Te To Ae ie baie ep estore oot o artes CLXVII. Lenearia.
666. Surface not marked with radial ribs, though radiating striz may be
PR ie eee Reet ere cate aca Gola Saki deaied ele asianiu asia send ads sve Lee

BE: PCIE SHON ANE TATGK ANG ee cach ose saeatsscsesseSheceweencosawcaess>s 227.
22t. Greatest length of shell parallel with the long, straight hinge

DSi ras Se Ratna cattun hee er omeated Ae Geas hoes ot aa oe tntinna Gileelotilde » 19*.

19*. Beaks terminal or practically so.CXXXI. Pleurophorus.

19*. Beaks varying from subcentral to anterior............. rey.

15/’. Aninternal rib present, running from beak to base.7’’.
j’’. Left valve with two cardinal teeth.
CLXXI. Siligua.
j’’. Left valve with one cardinal tooth.
CLXXII. Leptosolen.

15/’. No internal rib present......... CLXXIV. Legumen.

22f. Greatest length of shell parallel with the long, arcuate hinge
EIA, CR Oe Let au nen et P a Seles viene dates 20%,

20*, Shell with a small, anterior lobe....................000. 10/",
z6/’, Umbonal ridge present..... LX XXIV. Anthracomya.

16’. No umbonal ridge............... LXXXIII. Natadites.

20*. Shell without a small anterior lobe..................66+ ylides
Fy 7 Caxminal: teeta presents: 2) scdoeyeceanasces ween occa ve’ Rk’,

k/’, Cardinals small, several, coalescent.
LXXXV. Wyassa.

k/’, Cardinals one or two, large, heavy.
LXXXVI. Unio.
a7), MC BPGIMAL AB CE OUSOING oe etealy dadicu cadens aeeoewansse se Yf,
//’, Lateral teeth absent......... LXXXVII. Anodonta.

//’, Lateral teeth represented by one or two folds.

LXXXII. Amnigenia.
22+. Greatest length of shell at about 45° to hinge line........ ary,
21*, Beaks prominent, terminal, elongate................566+ re’,

372 NORTH AMERICAN INDEX FOSSILS.

18/’. Byssal opening very prominent..LI. Lunulicardium.
18’, Byssal opening not prominent.......CXVI. AZyétzlus.
21*. Beaks small, appressed, very anterior but not terminal.
Shell rounded anteriorly and posteriorly, rather tumid,

ASSUME REO METS a S28 casas a ection aw tise dain da ves salem 5.
z9/’. Cardinal area with many longitudinal grooves for
LiL Wie Cols IR gain ge an a eR RSE PRE Se 96 Ae

m’’, Grooved area on both sides of the beaks.
LXXVI. Ptychodesma.
m/’, Grooved area only posterior to beaks.
CXIII. ZLurymya.

ro’. “Cardinal ‘area mot grooved)... 2. s000.cceste save ni’,
GBF NGRE QreseMit 5 auc i593 Sse wien es anda go ee hice
4/’’. Cardinals one to three in each valve...... ae

a’//’, Surface with strong concentric ridges.
CXXXIII. Cypricardinia.
a’/’’, Surface with concentric striz ............ rT).
z). Anterior adductor very deeply impressed.
XLII. Lschyrodonta.
z). Anterior adductor not very strongly im- —
pressediii.:cstx-lcstens CX. Modiolodon.
4’/’. Cardinals, one strong in left valve and corre-
sponding cavity in right.
CIX. Modiomorpha,
4/’’. Cardinals, one strong in right valve and cor-
responding cavity in left...CXI. Colpomya.
4//’. Teeth few, microscopic, beneath the beaks.
CXVII. Modziola.
WF Teeth) ADSeht ..ccc.0sces, ooh dep. wewaienten neon es
5//’. Furrow present, passing from in front of the
umbo to the posterior basal margin.....0//7.
6//’, Umbonal ridge strong and angular.
CXV. Goniophora.
6///, Umbonal ridge rounded or wanting.....2).
2). Umbonal slope sharply limited anteriorly.

a).
a). Umbo long and pointed
CXVII. Modiola.
a). Umbo broad and rounded.
LXXVII. Modiella.
2). Umbonal slope not sharply limited an-

CETIGIY chroot ope CVIII. Modiolopsis.
3//7, No farrow. present. ....05.< <2: Jacene0seea lite
éf//, Valves equal . ....:.... CXII. Whiteavesia.

c//’, Valves unequal ; shell minute.
CXIV. Aristerella.

xx. Shell broadly oval to quadrate ...........cscsceeeeeeeeereneseee see 23T-
23}T. Beaks prominent...........cseccssesccceescecescevececeeseeenseee 22%)
22*, Umbonal ridge prominent............. CXXXVI. Venztella,

22%. Unibonal ridge) wanting, .2.....i5.6.......sesasduc es eeaa 20°F,

20’. Posterior cardinal tooth in right valve bifid at its

MOLLUSCA—PELECYPODA. 373

SUMAN A acsnntien neds daesestews CXXXIV. Astartella.

20/’, Cardinal teeth not bifid........... CXXXVII. Astarte,

237i) Bewics Gwiall /Appresseds. (kao «aces he saa nwcder ecerperesbaneess aay.
24%. Umponml ridge presents. : : ii..3 cajessces cancsecs tes cowbess oars

21/’, Length and height subequal.
CXXXII. Cypricardella.
21/’, Length much greater than height.
CLXXIX. Saxicava.
23*. Two weak umbonal ridges present, an anterior and a

POSREN TOR ee verte Sade sea sctinasts'vsce nes CLXXIII. Solyma.
29%. Umbonal ridge abseut.. oc. ccset scons CLXXX. Panopea.
xx. Shell subtriangular.............. : veers Zh T+

24t. Strong umbonal tae ecbehin’ running aca Beek to pos-
terior basal angle foe iscccccieWes teas. boat Suan enseats
24*, Beaks sehenditely it abe: Hiicebaineced.: promi-
nent concavity beneath the beaks..CXX XVIII. Opis.
aq”. Beaks not, CXCCedINETY PTOMINENt. <i... icecisowenseed-anieie22’"s
22/’, Cardinal teeth (6-8) radiating fait ne ee erica
the beaks... ieciinsssfin LL RXAVIT. Lyrodesma.
22/’, Cardinal teeth two in right valve, three in left;
teeth more or less transversely striated.......... rote
o/’, Surface with rows of nodes...........XC. Zvigonia.
of/, Sarface not podose. .....0:.:.. LXXXIX. Schizodus.
22/’, Cardinal teeth two in each valve..........0..sceecees ie
Oa re gS SATRINed ceils Souths adp enna se slasler'nss Gee.
6’’’. Inner margins of valves dentate.

CXXXIX. Crassatellites.

6’/’, Inner margins of valves not dentate.

CXL. Etéea.

POP BUIE SULAS PROSCUE 5, foe acc ge dentin datos ten ininees Phe
mire, Aapketal teeth prolonged... 5.2. siscee see uses ae,
ht NR ORT CL MESO Ma zcsaen coe cated uceeweaesins eae

3). Resilifer elongate.....CLXIX. Semele.

3). Resilifer spoon-shaped.
CLXX. Cumingia.
a’’’, No resilifer present...... CLXVI. Zelina,
7///, Lateral teeth minute if any.
CLXVII. nona.
22/’, Cardinal teeth two in right valve, one in left.
CLXXVIII. Corbula.

24t. Shell without strong umbonal ridge..................0eseeee- 25.
25*.. Surface radially strinte: . 523.50. i0s.. CXVIII. Crenella.
25", ‘OUEISCE,WithOUl TadiGh Strigs isa \sse de ccews fac ceceneots 23".

23/’. Beaks exceedingly prominent, strongly incurved.
LXXVIII. Aucella.

297//. Beaks but moderately prominent .................0.. "ee
g/’. Cardinal teeth one in each valve; no resilifer
present... dis Me Pebad ski eiexs CLI. Zancredia.

q/’. Cardinal teeth two in each valve.
: CXXXVII. Astarte.
g/’. Cardinal teeth, two in right valve, one in left...87/7.

374 NORD AMERICAN ANDEX. FOSSILS,

8//’, Resilifer and ligament scar separated by a

EDIMSSED MUN ore wees che ces CLXXV. Mactra.
8//’. Resilifer and ligament scar not separated by
A" Sep iin ie. sda sh and sue tae elt,

e’’’, Margins of the combined resilifer and
ligament pit elevated.
CLXXVI. Cymbophora,
e’/’, Margins of pit not elevated.
CLXXVII. Schizodesma.
g’’. Cardinal teeth three in each valve.

CXLII. Corbicula,
xx. Shell semicircular and exceedingly thin...... CVI. Placunopsis.
Hy: SHSM ea CTCUNEE SS, Jones os sp coche ceed Picea eet cael oe 25t.
25f. Shell exceedingly thin, fragile, translucent................. 26%,
26*. Lower valve flat, perforated for the byssus ; upper valve
COMYE RG ik asin dost adtavsuasaneds sumee tera eteee CV. Anomia.

26*, Lower valve flat, not perforated for the byssus,
CVI. Placunopsis.

25;- Shell of median thickness 1.2. )c05c0sc5<. cscs ee 27%
27*.' Beals prominent oli. iv esd seemavsckectans oes cee Oe aid
24/’. Beaks spirally enrolled forward.....CLIX. Jsocardia.

24/’, Beaks merely curved forward.::.......:..0ssseestee 77%,

r/’, Cardinal teeth three in each valve.... .........9//7.

of/*, \Pallal-sinds present, .2.....2 cere eR bats

jf’. Pallial sinus lofg......:.. CLXI. Clementia.

f'’’. Pallial sinus: short: . 0.2. ..sgenestess eee 4).

4). Lateral teeth present....2.5...eecaeaee b).

6). A posterior lateral tooth in right
valve; height and length of shell
subequal.....CLXIV. Dosinzopsts.

6). No posterior lateral present; length
of shell greater than height.

CLXIII. Afleretrix.
4). Lateral teeth: absént....../....0.0tae c)s
c). Inner margins of valves crenulate.
CLXII. Venus.
c). Inner margins of valves smooth.
CLXV. Zapes.
o//’.. Pallial line ‘entire..-...47..4< CXXXV. Arctica.
7//, Cardinal teeth two in each valve........ssesses 10",
zo’’’, Left anterior and right posterior cardinal
teeth prolonged and curved,.CLVI. Zenea.
zo//’, Cardinal teeth not prolonged.
CLV. Diplodonta.
r/’. Cardinal teeth two in right valve and three in left.
CLX. Cyprimeria.
24/’, Beaks not curved ; shell inflated.
e CXLIII. Spherium.
27*,. Beaks small and ‘subcenttal.s.....20..2:..c.2+..2.5eeee agit.
25/’, Concentric sculpture strong and irregular.
CLIII. Paracyclas.

PELECYPODA—PRIONODESMACEA. 375

25"/,..Concentric sculpture, delicate: .:..2t4suesawacnperse si
Ge SC SREU, WAHATOES 50) casas pica seeops CXLIII. Spherium.
s/’, Shell but slightly convex............ CLIV. Lucina.

OrpER I. PRIONODESMACEA.

I. Soctemya Lamarck.

Elongate-cylindrical, gaping at each end, with obtuse extremi-
ties and very low beaks. Ligament internal, posterior, inserted
on an oblique process beneath the beak. No distinct pallial line.
Devonic—Recent.

1. S.(?) vetusta Meek. (Fig. 477, 2.) Devonic.

FIG. 477. a, Solemya ? vetusta, right valve ; 4, Clinopistha subnasuta, cardinal view,
showing callosity in front of beaks, Hamilton group ; c, same, right valve, Onondaga ;
ad, Phthonia cylindrica, right valve ; e, Prothyris lanceolata, right valve ; 7, Orthonota
carinata, both valves in conjunction, < 2. (Pal. N. Y., V.)

Anterior end longer. Surface marked by regular, distinct, and

lamellose concentric striz.
Onondaga: Ohio. Hamilton Group: Falls of Ohio.

2. S. occidentalis Stanton. (Fig. 478, a.) Comanchic.
Beaks directed backwards. Surface marked with distant, im-
pressed radiating lines, most prominent in the middle of the shell,

Fic. 478. a, Solemya occidentalis, internal mold of large right valve, with un-
usually strong radiating lines (U. S. G. S., Bull. 133) ; 4, c, Clinmopistha radiata, left
and dorsal views. (Ind. Surv. )

376 NORTH “AMERICAN INDEX FOSSILS.

and by obscure radiating ridges most prominent anteriorly. These
markings are preserved also on molds.
Abundant in Knoxville of California.

II. CiinopistHA Meek.

Moderately convex, with nearly straight basal margin, rounded
posterior, and short, subnasute anterior end. Callosity present in
place of lunule, anterior to beaks. Surface marked by fine growth
strie. Hinge possibly crenulated. Ligament external. Pallial
line simple. Devonic and Carbonic.

3. C. subnasuta (Hall & Whitfield). (Fig. 477, 0-c.) Devonic.
Hinge line gently arcuate. Anterior end nasute.
Hamilton: Kentucky.

4. C. radiata Hall. (Fig. 478, d-c.) Carbonic.
Anterior end scarcely nasute.
Coal Measures: Ohio—Missouri.

III. Paruonia Hall.

Elliptical, with short anterior end. Beaks small and appressed.
Hinge line straight or slightly arched. Umbonal slope more or
less distinctly defined. Surface marked with fine concentric striz,
and at times with radiating strie. Ligament external. Pallial
line simple. Devonic.

5. P. cylindrica Hall. (Fig. 477, d.) Devonic.
Radiating striz obscure or absent. Hinge arched.
Hamilton: New York.

IV. Sancuinovites McCoy.
Equivalve, elongate, obliquely truncate behind,- with beaks low

and near the anterior end. Surface concentrically striated and —

Fic. 479. Sanguinolites golus. (Pal. Ohio, II.)

bearing a ridge extending from the beak to the basal posterior
margin. Teeth absent; anterior adductor scar buttressed by a
ridge. Ligament external. Pallial line simple. Miss.—Carbonic.

PELECYPODA—PRIONODESMACEA. 377

6. S. eolus Hall and Whitfield. (Fig. 479.) Mississippic.
Two or three very obscure longitudinal ridges between the
slightly convex umbonal slopes and the cardinal margin.
Ohio (Cuyahoga shale), Nevada.

V. Protuyris Meek.

Thin-shelled, elongate, with very anterior beaks, and often nearly
parallel cardinal and basal margins. Lower anterior end gene-
rally notched. Surface covered with fine concentric striz. Hinge
without teeth. Ligamentexternal. Pallial line simple. Devonic
and Carbonic.

7. P. lanceolata Hall. (Fig. 477, ¢.) Devonic.

Length three times the height ; oblique, and pointed posteriorly.
Anterior end subtruncate, only slightly constricted, and lacking
any conspicuous notch.

Hamilton: New York, Pennsylvania. Portage: Pennsylvania.
8. P. elegans Meek. Carbonic.

Anterior notch well defined. Surface marked with an obscure
fold and furrow parallel to the hinge line. Striz nearly obsolete
on upper portion of shell. Length nearly three and one half times
height. Type of genus.

Ohio and Michigan to Nebraska.

VI. OrtHonota Conrad.
Extremely elongate, with very anterior beaks. Cardinal and

Fic. 480. Orthonota undulata. (Pal. N. ¥., V.)

basal margins straight and parallel. Umbonal slope defined by
one or more distinct folds which extend from the beak to the pos-

378. NORTH AMERICAN INDEX FOSSILS.

terior basal margin. Surface marked with concentric striae. Hinge

without teeth. Pallial line simple. Ordovicic—Devonic.

g. 0. undulata Conrad. (Fig. 480.) Devonic.
Posterior end nearly vertically truncate. Surface marked by

distinct undulations anteriorly and posteriorly.
Hamilton of New York and Pennsylvania; also Ithaca of New

York.

10. 0. carinata Conrad. (Fig. 477, /) Devonic.
Posterior end doubly emarginate. Postero-cardinal slope longi-

tudinally ridged.
Hamilton: New York, Pennsylvania.

VII.. CungamyaA Hall and Whitfield.

Differs from Grammysia in that the hinge plate is weak and with-
out teeth. A shallow median furrow usually present. Ordovicic.

11. C. miamiensis Hall and Whitfield. (Fig. 481.) Ordovicic.

Fic. 481. Cuneamya miamiensis. (Pal. Ohio, II.)

Posterior end acutely rounded.
Cincinnati Group: Ohio, Indiana.
12. C. truncatula Ulrich. (Fig. 482, a.) Ordovicic.
Anterior end truncate. Median furrow broad.
Middle Galena of Minnesota.

Fic. 482. a, Cuneamya truncatula, internal mold of right valve; 4, c, Orthodesmg
subnasutum ; d, e, O. canaliculatum, right and dorsal views. (Ulrich, Minn. Pal. )

PELECYPODA—PRIONODESMACEA. 379

VIII. Ixronta Billings.

Anterior end of shell larger than posterior. A broad furrow
extends from the umbos to the posterior basal margin. A large
subovate muscular scar in the upper half of the posterior
extremity. Noteeth. Siluric.

13. I. galtensis Whiteaves. (Fig. 483.) | 'Silurie.

Fic, 483. /lionia galtensis, left and right valves. (After Whiteaves. )

Umbos broad, subcentral. Surface concentrically striate.
Guelph: New York, Ontario. Cobleskill: New York.

14. I. sinuata Halil. Siluric.
Surface marked by two furrows extending posteriorly from the
beak, the one obliquely, the other vertically.
Cobleskill and Manlius of New York.

IX. OrtTHODESMA Hall and Whitfield.

Transversely elongate, somewhat higher posteriorly than anteri-
orly. Valves thin, gaping at each end, usually marked by an
umbonal ridge, anterior to which is a broad depression. Surface
marked by more or less distinct concentric striz. Hinge plate
without teeth, thin andlong. Ligament mostly external. Pallial
line simple. Ordovicic.

15. O. rectum Hall and Whitfield. (Fig. 484.) Ordovicic.

Fic. 484. Orthodesma rectum. (Pal. Ohio, II.)

Cardinal and basal lines straight and converging forwards.
Posterior end obliquely truncate.
Cincinnati Group : Ohio, Indiana.

380 NORTH AMERICAN INDEX FOSSILS.

16. O. subnasutum (Meek and Worthen). (Fig. 482, d-c.)
Ordovicic.
Cardinal and basal margins slightly diverging and curving.
Concentric undulations irregular.
Galena: Illinois, Minnesota.

17. QO. canalicylatum Ulrich. (Fig. 482, d-e.) Ordovicic.

Differs from other species in the strong, channel-like depression
of the hinge line, the nearly parallel cardinal and basal margins,
the rounded posterior margin, and in the peculiar pallial line
which consists (on the internal molds) of a straight row of obscure
pustules extending backward from the base of the anterior
adductor scar.

Cincinnati Group: Ohio, Indiana, Minnesota; Trenton of New

Jersey.
X. GRAMMyYSIA de Verneuil.

Fic. 485. a, Grammysia ovata; 6b, G. bisulcata ; c,d, G. globosa. (Pal. N. Y., V.)

Beaks prominent and incurved, anterior to middle. Escutcheon,
and lunule well defined. Valves often traversed from beak to base

PELECYPODA—PRIONODESMACEA. 381

by an oblique sinus or depression and adjacent fold, which may
be duplicate and which alternate in the two valves. Surface marked
with concentric growth lines and commonly with concentric undula-
tions. Hinge plate short and strong, with one or two cardinal folds
in the typical forms. Ligament external. Pallial line simple.
Siluric-Carbonic.

18. G. ovata Hall. (Fig. 485, 2.) : Devonic.
Length about one third greater than height. Surface marked
with subangular, concentric undulations. Sinus shallow and un-
accompanied by folds.
Onondaga: Ohio.

19. G. bisulcata (Conrad.) (Fig. 485, 0.) Devonic.
Distinguished by the strong fold with a furrow on each side, ex-
tending from beak to base and by the strong and regular concen-
tric ridges.
Hamilton: New York, Pennsylvania.

20. G. globosa Hall. (Fig. 485, cd.) Devonic.
Distinguished by its comparatively small size and by its globu-
lar form. No fold or sinus.
Hamilton: New York.

21. G. nodocostata Hall. (Fig. 486, a—d.) Devonic.
Outline oblique ; hinge line short and straight. Surface marked
with numerous concentric folds and on the umbo with radiating
nodose ridges.
Hamilton: New York.

22. G. obsoleta Hall. (Fig. 486, c.) Devonic-
Large, broadly ovate or elliptical from pressure, constricted at
middle of base. Hinge line arcuate and more than half the length
of the shell. Sinus and ridge present anteriorly. Differs from G.
circularis in having the anterior fold and sinus and in not being
flattened.
Hamilton: New York.

23. G. alveata (Conrad). (Fig. 487.) Devonic.

Hinge line short, almost winged posteriorly. Valves convex
below and ventricose above. Surface marked with fine concentric
striz and, anterior to the umbonal slope, by concentric folds which
are absent on the posterior slope.

382 NORTH AMERICAN INDEX. FOSSILS.

Hamilton: New York, Virginia.
24. G. lirata Hall. (Fig. 486, a.) Devonic.

S78

See SU

ES .

Fic. 486. a,5, Grammysia nodocostata; c, G. obsoleta; d, G. lirata; e,f, GC.

arcuata; g, G. circularis, left valve, partly denuded of shell, showing muscle scars
and pallial line ; 4, G. communis ; i, G. undata, a small left valve. (Pal. N. Y., Ve)

tat

PELECYPODA—PRIONODESMACEA. 383

Differs from G. a/veata in its smaller size and in the presence of
concentric folds on the posterior slope.
Hamilton: New York, Pennsylvania, Virginia.

25. G. arcuata (Conrad). (Fig. 486, ce) Devonic.
Distinguished by its somewhat elongate form, rounded posterior

extremity, flattened or constricted base, and by the extension of
’ the concentric folds across the whole length of the shell.

Hamilton of New York and the Appalachian region.

26. G. circularis Hall. (Fig. 486, z.) Devonic.
Subcircular, with lightly impressed fold and furrows extending
from beak to base.
Hamilton and Chemung of New York.

27. G. communis Hall. (Fig. 486, %.) Devonic.

Ns oe f

;

Fic. 487. Grammysia alveata. (Pal. N. Y., VY.)

Elongate, with subangular umbonal slope, oblique sinus, and
strong concentric undulations.
Chemung: New York, Pennsylvania.

28. G. undata Hall. (Fig. 486, 2.) Devonic.

Similar to G. communis, but has fewer concentric undulations,
a less angular umbonal slope, broader posterior end, and a more
nearly vertical sinus.

Chemung: New York, Pennsylvania.

29. G. hannibalensis (Shumard). Mississippic.

Similar to G. communis but is higher proportionally, and has a
more broadly rounded umbonal slope.

Characteristic of the Waverly and equivalent formations from
Ohio to Missouri ; also in the Mississipic of Nevada.

384 NORTH AMERICAN INDEX FOSSILS.

XI. GtossitTes Hall.

Elliptical, with short anterior and large, rounded posterior
extremity. Beaks small and appressed. Hinge line long and
gently arcuate. Umbonal slope prominent only above. Surface
marked with fine concentric striz which often become lamellose.
Lunule distinct. Teeth doubtful. Ligament external. Muscular
impressions shallow.

Distinguished from Modiomorpha by its regular elliptical outline
and by the presence of a lunule. Devonic.

30. G. lingualis Hall. (Fig. 488, a.) Devonic.
Length usually a little more than twice the height.
Chemung Group: New York, Pennsylvania.

Fic. 488. a, Glossites lingualis, left valve; 6,c, Paleanatina typa, left and right
valves; @, Tellinopsis subemarginata ; e, Cardiopsis radiata. (N. Y. Surv.)

XII. Sarrorpia Ulrich.

Rather small, transversely ovate, equivalve, and very inequi-
lateral, with beaks near the anterior extremity. Surface bearing
a moderate umbonal ridge and a more or less distinct depression
dorsally. Lunule and escutcheon present. One wedge-shaped
cardinal tooth and a posterior lateral tooth present in left valve
and corresponding cavities in the right. Resilifer present. Pal-
lial line simple.

Differs from Cuneamya in the thicker shell, more distinct muscu-
lar impressions, arcuate posterior cardinal margin, and different
hinge characters ; from Grammysta in the teeth and in the greater
depth of the anterior muscle scar. Ordovicic.

—-

PELECYPODA—PRIONODESMACEA. 385

31. S. modesta Ulrich. (Fig. 489, c.) Ordovicic.
Quite small, obliquely ovate.
Lower Galena: Wisconsin, Minnesota.

32. S. ventralis Ulrich. (Fig. 489, a—0.) Ordovicic.
More nearly circular than S. modesta.
Upper Cincinnati Group : Wisconsin, Minnesota.

XIII. PALazaANnATINA Hall.

Left valve larger than right. Elliptical, with short anterior and
longer posterior end. Beaks low, that of left valve rising above
that of right. Umbonal slope prominent. Valves crossed from
beak to base by a shallow depression ; both umbonal ridge and
depression less prominent in right valve. Surface covered with

Fic. 489. a, 6, Saffordia ventralis, view of left valve; c, Saffordia modesta, left view
of internal mold; d, ¢, Pstloconcha grandis, left and cardinal views. (Minn. Surv. )

fine concentric striz. Hinge with two slender processes beneath
the beak. Pallial line simple. Devonic.

33. P. typa Hall. (Fig. 488, d-c.) Devonic.
Left valve somewhat gibbous at umbo. Right valve depressed-
convex. Beaks anterior to middle.
Chemung Group: New York.

XIV. TeEtutnopsis Hall.

Elliptical, with rounded anterior and truncate or emarginate
posterior end. Beaks small, subcentral. Umbonal slope promi-
nent. Surface marked with concentric striz and weak radiating
strie. Hinge without teeth. Ligament external. Muscular im-
pressions shallow. Devonic.

386 NORTH O AMERICAN INDEX FOSSILS.

34. T. subemarginata (Conrad). (Fig. 488, @.) Devonic.
From the beak a flattening or depression extends to both the
anterior and the posterior margin. Type of genus.
Hamilton : New York, Pennsylvania.

XV. CARDIOMORPHA de Koninck.

Equivalve, inequilateral, oval, gibbous. Beaks almost at the
anterior extremity, prominent, spirally enrolled toward the front.
| Hinge line thin, arched. Hinge margin in-
flected nearly at right angles to form a hollow
lunette extending from the beak nearly to the
cardinal angle. Hinge teeth absent. Pallial

Fic. 490. Cardio- Jine simple. Ordovicic to Carbonic.
morpha missourten-
sis. (Kan. Pal., 35. C. missouriensis Shumard. (Fig. 490.)
VI/IL.)

Carbonic.
Surface marked with fine and crowded concentric striz.
Coal measures of Illinois, Kansas, Missouri, Nevada.

XVI. Carpbiopsis Meek and Worthen.

Valves gibbous, inequilateral, subcircular, with short hinge line
and prominent and incurved beak. Surface marked with radiating
striz or costz and with concentric growth lines. Hinge with one
or two cardinal teeth. ?

Differs from Cardiomorpha in the presence of cardinal teeth and
radial sculpture. Miss.—Carbonic.

36. C. radiata Meek and Worthen. (Fig. 488, ¢.) Mississippic.
Coste sharp, alternating in part. Type of the genus.
Kinderhook : Indiana, Illinois.

XVII. PsiroconcHa Ulrich.

Shell very thin, elongate, inequilateral, gaping slightly at both
ends. [linge plate very narrow, without
teeth. Ligament internal, linear. Mus-
cular impressions very shallow, the poste-
rior three times the length of the anterior. “™

Pallial line simple. Ordovicic. Fic. 491. Psiloconcha inor-
: g . nata. (After Ulrich, Pal.
37. P. grandis Ulrich. (Fig. 439, ad—e.) O., VIL.)

Ordovicic.

Posterior margin regularly rounded ; anterior angular.
Upper beds of Cincinnati Group of Ohio.

- > ee

PELECYPODA—PRIONODESMACEA. 387

38. P. inornata Ulrich. (Fig. 491.) Ordovicic.

Both ends regularly rounded. Surface marked only with
obscure concentric striz, usually appearing almost smooth.

Lorraine of Ohio.

XVIII. Cuznomya Meek.

Thin, equivalve, inequilateral, longitudinally oblong or subcyl-
indrical. Anterior side rounded, closed ; posterior long, truncated
and gaping. Surface marked with radiating granules and with
concentric growth lines. Cardinal margin inflected as in Aorisma.,
Teeth absent. Ligament external. Scars of anterior adductors
and pedal muscles connected. Pallial line with broad, shallow
sinus. Carbonic and Permic.

39. C. leavenworthensis Meek and Hayden. (Fig. 492.)
Carbonic and Permic.
Surface covered with growth lines and a few concentric undula-

Fic. 492. Chenomya leavenworthensis (Kan. Pal., VI/II.)

lations which curve up abruptly behind, parallel to the truncated

posterior margin. Type of genus.
Coal Measures of Illinois and Iowa to Colorado ; also Permic of

Kansas.

4o. C. minnehaha Swallow. Carbonic and Permic.

Smaller than preceding, with prominent posterior umbonal slope.
Coal Measures of Iowa, Illinois, Missouri, Nebraska ; Permic of
Kansas.

388 NORTH AMERICAN INDEX FOSSILS.

XIX. Epmonpia de Koninck.

Oval or subcircular, gaping anteriorly. A narrow ridge present
behind the beaks. Beaks varying from subcentral to nearly an-
terior. Surface marked by concentric striz. Hinge line thin,
arched, lacking teeth. Ligament external, resting in a groove
along the hinge line. Pallial line simple. | Devonic—Carbonic.

41. E. philippi Hall. (Fig. 493, 2.) Devonic.
Distinguished by its broadly oval form, at times almost circular,

: a
Fic. 493. a, Edmondia philippi,; 6, E. subovata, right valve; c, EZ. dburlingtonensis.
(Pal. N. Y., V.)
by the nearly central beaks, and by the fine concentric strize which

often become lamellose.
Chemung Group: New York, Pennsylvania.

42. E. subovata Hall. (Fig. 493, 2.) Devonic.
Elliptical. Beaks somewhat anterior.
Chemung: New York, Pennsylvania.

43. E. burlingtonensis White and Whitfield. (Fig. 493, c.)
Mississippic.
Differs from £. subovata in the more anterior beaks and in the
straighter base.
Lower Mississippic of Ohio, Iowa, Missouri.

Fic. 494. Ldmondia aspinwallensis, right and cardinal views. (Ind. Surv.)

44. E. aspinwallensis Meek. (Fig 494, a-0.) Miss.—Carbonic.
Greatest convexity of valves is in front of middle.
Mississippic of Utah; Coal Measures of West Virginia to Ne-
braska and Missouri.

<a ee meee err

— EO ee? ee

PELECYPODA—PRIONODESMACEA. 389

XX. Forpiizia Barrande.
Minute, thick, oval. Hinge margin nearly straight. Surface

concentrically striated.
This may be a bivalve crustacean allied to Estheria. Cambric.

45. F. troyensis Barrande. (Fig. 495.) Cambric.
Lower Cambric of southeastern New York, eastern Massa-
chusetts ;

Fic. 495. Fordilla troyensis, right valve and right internal mold, enlarged. (U.
5, G.'S.; Amn. 10.)

XXII. PANENKA Barrande.

Equivalve. Length and height nearly equal. Beaks prominent
and incurved. Hinge line straight or
arcuate. Shell thin, marked by growth
lines and usually by strong radii.
Siluric—Devonic.

46. P. canadensis Whiteaves.
Siluric.
Subcircular to longitudinally subo-
vate ; umbones prominent, surface with
numerous ribs.
Upper Monroe of Michigan, Ohio
and Canada.

: : Fic. 496. phere dichotoma.
47. P. dichotoma Hall. (Fig. 496.) (Pal. N. Y., V.)

Devonic.

Convex below, gibbous above. Hinge line short and straight.
Schoharie: New York.

48. P. ventricosa Hall. (Fig. 497, a—d.) Devonic.
Distinguished by its subcircular form, straight hinge line, ex-
tremely ventricose valves, prominent, subcentral beaks and nu-
merous, fine and close radii.
Agoniatite limestone of Marcellus shale: New York.

390 NORTH AMERICAN INDEX FOSSILS.

49. P. hero Hall. (Fig. 497, @.) Devonic.
Distinguished by small size, small, subcentral beaks, and strong,
distant radii.

Marcellus shale: New York.

Fic. 497. a, 6, Panenka ventricosa, \eft valve and cardinal view showing triangular area
under the beak; c, P. potens, right valve; d, P. hero, left valve. (N. Y. Surv.)

50. P. costata Hall. (Fig. 498, 2.) Devonic.
Differs from P. kero in the broader, more rounded radii and in
its larger size.

Marcellus shale: New York.

51. P. potens Hall. (Fig. 497, c.) Devonic.
Large ; radii rounded, numbering 35 to 4o.
Hamilton: New York.

PELECYPODA—PRIONODESMACEA. 391

52. P. robusta Hall. (Fig. 498, a.) Devonic.
Much like P. dichotoma but the plications are more elevated and
angular and rarely bifurcate.
Portage Group: New York.

Fic. 498. a, Panenka robusta, left valve; 6, P. costata, left valve. (N. Y. Surv.)

XXII. Ontaria Clarke. (Cardiola Broderip in part.)
Equivalve, exceedingly thin; beaks not very prominent, turned
posteriorly. Cardinal area beneath the beak nearly extinct. Sur-
face covered with fine concentric and radiating striae. Devonic.

Fic. 499. Ontaria suborbicularis, X< 2, with enlargements"of cardinal region, X 5.
(N>¥.. Mem; 6.)

53. O. suborbicularis (Hall). (Fig. 499.) Devonic.
Suborbicular; beak central to subcentral. Surface marked
with sharp, imbricating concentric striz ; very fine radial striz may
be present.
Portage (Naples fauna) of New York.

392 NORTH AMERICAN INDEX FOSSILS.

XXIII. Paracarpium Barrande.
Small, circular. Beaks high and slightly projecting. Surface
marked with fine, simple radial ribs. Hinge at times with a row
of minute tooth-like projections. Siluric and Devonic.

Fic. 500. Paracardium doris Hall, a small right valve, < 5 (slightly transverse from
compression) ; a larger left valve, 3; interior, X 10. (N.Y, Mem., 6.)

54. P. doris Hall. (Fig. 500.) Devonic.
Beaks minute, incurved, and directed forward. Surface covered

with 20 to 25 fine, rounded ribs, separated by narrower furrows.
Portage: New York, Pennsylvania.

XXIV. BucHIo.La Barrande.

Cardinal line long and straight. Beaks pointing forward. A
row of minute, tooth-like projections often present on the outer
edge of the narrow cardinal area. Surface marked with a few

Fic. 501. Buchiola retrostriata, conjoined valves, X 3; umbonal view of right
valve, showing the thin upturned edge of the hinge line, & 5; a right valve with
sharply defined features, 3. (After Clarke, Mem, 6, N. Y. State Mus.)

broad plications crossed by fine lines curved prominently upward
as they cross the ribs. Siluric and Devonic.

PELECYPODA—PRIONODESMACEA. 393

55. B. retrostriata von Buch. (Fig. 501.) Devonic.

Shell very convex. Umbos large, closely incurved. Surface of
ribs flat or concave with backward curving growth lines; grooves
narrower than ribs.

Portage: New York (also Genesee), Pennsylvania, Appa-
lachians.

XXV. Crenoponta Salter.

Equivalve. Surface smooth or with concentric growth lines.
Hinge arcuate, with a series of curved, transverse teeth which is
at times interrupted beneath the beaks. Cardinal area not
striated. Ligament small, immediately behind the beaks. Ad-
ductor muscle impressions nearly equal. Pallial line simple.

Differs from ucula in the absence of resilifer beneath the beak,
and in the absence of a flattened area (lunule and escutcheon).
Ordovicic and Siluric.

56. C. nasuta (Hall). (Fig. 502, 0.) Ordovicic.

Fic. 502. a, 6, Ctenodonta logani; c, d, C. gibberula, exterior of right valve and
internal mold of left; ¢, f, C. socials (f= hinge of right valves enlarged, 3) ; g, 4,
C. fecunda, right and\ cardinal views ; 7, 7, C. od/igua, internal molds, peak ar ae Fike a Oe
alta; m, C. albertina; n, C, calvini, internal mold of left valve; 0, C. nasuta, left
valve. (Minn. Surv. )

Teeth in a continuous and almost straight series.
Stones River: Tennessee, Illinois, Wisconsin. Black River :
New Jersey, Tennessee, Illinois, Minnesota, Wisconsin, Ontario.

57. C. gibberula Salter. (Fig. 502, cd.) Ordovicic.
Hinge strongly bent. Muscle scars prominent.
Stones River: Minnesota. Black River: Tennessee, Illinois,
Wisconsin, Iowa, Ontario.

394 NORTH AMERICAN INDEX “POSSTES:

58. C. logani Salter. (Fig. 502, a—0.) Ordovicic.
Beaks large. Muscle scars faint ; hinge nearly straight.
Black River : Wisconsin, Ontario.

59. C. socialis Ulrich. (Fig. 502, e/) Ordovicic.
Shell very small, quite inequilateral. Convexity moderate.
Very abundant in the Black River shale of Minnesota.

6o. C. alta Hall. (Fig. 502, £-/.) Ordovicic.
Erect, subtriangular. Hinge plate as in C. obfigua.
Galena: Illinois, Wisconsin, Minnesota.
61. C. levata Hall. Ordovicic.
Differs from C. alvertina in its greater proportional height and
convexity, and in the absence of a pit beneath the beak.
Trenton: New York, New Jersey, Wisconsin. Lorraine :
Pennsylvania.

62. C. astartiformis Salter. Ordovicic.
Differs from C. obfigua in its larger size (about twice that of
the smaller form), in its smaller and more bent beaks, and in ‘its
stronger and more irregular concentric striz.
Trenton: New York ?, Quebec, Lake Winnipeg, Manitoba.

63. C. fecunda Hall. (Fig. 502, g—/.) Ordovicic.
Hinge plate arcuate. + Muscle scars faint. Form suboval.
Maquoketa : Illinois, lowa, Wisconsin, Minnesota.

64. C. calvini Ulrich. (Fig. 502, z.) Ordovicic.
Differs from C. fecunda in its larger size and greater posterior

height.

Maquoketa : Illinois, Iowa.

65. C. obliqua Hall. (Fig. 502, 7.) Ordovicic.
Very small. Concentric lines comparatively strong. Hinge

plate bent at’ nearly a right angle.

Cincinnati group of Ohio, Indiana. Maquoketa of Iowa and
the Northwest.

66. C. albertina Ulrich. (Fig. 502, m.) Ordovicic.
Hinge plate sharply bent ; a small pit present beneath the beak.
Upper beds of Cincinnati group of Ohio and Minnesota.

67. C. macheriformis Hall. } Siluric.
Shell thin, elongate. Beak subanterior. Surface marked with

minute, equal, concentric striae. Dimensions 14 x % inches.
Clinton: New York.

PELECYPODA—PRIONODESMACEA. 395

68. C. equilatera Hall. Siluric.

Elliptical ; anterior and posterior ends nearly equal. A groove
extends from the beak nearly to the posterior extremity. Dimen-
sions I} x % inches.

Cobleskill: New York.

AX VAI Nucuca Lamarck.

Pearly, small, equivalve, varying in outline from trigonal to
nearly circular or transversely elliptical. Beaks often subcentral,
usually posterior to the middle and turned backward. Surface
marked by concentric striz. Hinge with a triangular resilifer
beneath the beaks and a series of small transverse teeth on each
side. Two subequal adductor muscle impressions in each valve.
Pallial line simple. Interior margins often crenulate. (Probably
a polyphyletic group.) Ordovicic—Recent.

69. N. lirata (Conrad). (Fig. 503, d.) Devonic.

Fic. 503. a, b, Nucula houghtoni; c, N. randalli,; d, N. lirata ; e, N. bellistriata ;
J, XN. corbuliformis, (N. Y. Surv.)
Gibbous. Concentric undulations strong and subangular.
Hamilton: New York, Pennsylvania, Ontario. Onondaga:
Indiana.

70. N. randalli Hall. (Fig. 503, c.) Devonic..
Valves ventricose, their depth conjoined equalling their height.
Striz fine and thread-like but interrupted, especially toward the
front, by growth varices.
Hamilton: New York, etc.

71. N. bellistriata (Conrad). (Fig. 503, ¢.) Devonic.

_ Differs from WV. vandali in its broadly ovate outline, less

gibbous valves, and finer striz, usually without varices of growth
Hamilton: New York, etc.

396 NORTH AMERICAN INDEX FOSSILS.

72. N. corbuliformis Hall. (Fig. 503, /) Devonic.
Distinguished by its small size and by its nearly equilateral
triangular form.
Hamilton: New York, Pennsylvania.

73. N. houghtoni Stevens. (Fig. 503, a—0.)
Upper Devonic and Mississippic.
Resembles WV. randall but is proportionally shorter and the
very fine concentric lines are uninterrupted by varices.
Chemung: Iowa. Waverly: Ohio, Michigan.
74. N. ventricosa Hall. (Fig. 504.) Carbonic.
Very convex. Concentric striz fine and regular.
Coal Measures: West Virginia to Colorado and Oklahoma.

75. N. beyrichi von Schauroth. (Fig. 505.) Carbonic.
Fic. 504. Mucula ventricosa. Fic. 505. Nucula beyrichi.
(Kan. Pal., VI.) (Kan. Pal., VI.)

Very small. Hinge line nearly rectangular at beaks.
Coal Measures of Illinois, Kansas, Nebraska, Iowa.

76. N. cancellata Meek and Hayden. Cretacic.

Subtrigonal, rather gibbous. Hinge line sloping abruptly an-
teriorly and posteriorly from the beak. Beaks slightly anterior
to the middle, and incurved nearly to touch each other. Surface

marked with radiating striz, crossed by fine concentric lines, so as_

to form a cancellate sculpture. Length about 1 inch; height
about 2 inch.

Pierre: Montana, North Dakota. Fox Hills: South Dakota,
Nebraska, Colorado. Montana of Alberta. Also in Mexico.

Fic. 506. Mucula percrassa, internal molds. (Pal. N. J., 1.)

77. N. percrassa Conrad. (Fig. 506.) Cretacic.

Large. Surface covered with irregular concentric lines and fine
radiating coste most strongly developed anteriorly. Well pre-
served internal casts are strongly crenate on the margin.

—

PELECYPODA—PRIONODESMACEA. 397

Ripleyan of New Jersey (Cliffwood—Wenonah), Maryland,
North Carolina, Alabama, Mississippi, Texas.

78. N. whitfieldi Weller. Cretacic.
Differs from WV. percrassa in the absence of radiating coste and
marginal crenulations.
Ripleyan of New Jersey (Cliffwood—Red Bank).

79. N. ovula Lea. (Fig. 507.) Eocenic.
Margin very minutely crenulated.
Maryland (Aquia), Alabama (Midway and Lignitic).

XXVII. Nucyrites Conrad. (Clecdophorus Hall.)

Differs from ucula in the absence of the resilifer beneath the
beak, the row of teeth extending without interruption from the
anterior muscle scar to the posterior, and
in the presence of a nearly or quite verti-
cal partition internally, separating the ante-
rior muscle scar from the cavity of the shell
and extending about two thirds the distance
from beak to base. This partition leaves a
deep furrow on the casts of the interior of

Fic. 507. Nucula ovula.

the shell in which condition specimens of (Md. Geol. Surv.)

Nuculites are usually found. Ordovicic—Devonic.

80. N. planulatus (Conrad). Ordovicic.

Differs from WV. neglectus in its smaller size, more prominent
umbonal ridge extending from the beak to the posterior extremity,
and in the conspicuous flattening of the shell hingeward from this
ridge.

This species is the type of Hall’s genus Clezdophorus founded
upon the fact that no hinge teeth had been ob-
served and also because of the flattening of the
shell just noted.

Lorraine: New York, Pennsylvania. Utica:
New York.

ee oR Nuculites 81. N. neglectus Hall. (Fig. 508, a—c.) eS
- (Cidophorus) neg- Ordovicic.
lectus. a,b,exter- Differs from LV. odlongatus in its smaller size
nal views; ¢, inter- eSshic ; ;
and in its subequal anterior and posterior ex-

nal mold, enlarged. rs
(Minn. Surv.) tremities.

398 NORTH AMERICAN INDEX FOSSILS.

Characteristic of the Maquoketa shale of Illinois, Iowa, Wis-
consin, Minnesota.

82. N. oblongatus Conrad. (Fig. 509, a—c.) Devonic.
Elongate-ovate, widest anteriorly. Beaks appressed and low.
Surface marked by very fine concentric striz.
Very abundant in the Hamilton: New York, Pennsylvania,
Virginia. Also present in Marcellus of New York and Portage
of Pennsylvania.

83. N. triqueter Conrad. (Fig. 509, a) Devonic.
Distinguished by its trigonal form, prominent arching beaks and
strongly arching umbonal ridge.

Very abundant in the Hamilton: New York, Pennsylvania, Vir-

d
FIG. 509. a-c, Nuculites oblongatus ; d—f, N. triqueter. (N.Y. Surv., V.)

ginia, Ontario. Also present in the Marcellus of New York, and
Portage of Pennsylvania.

XXVIII. PaLaonerLo Hall.

Shell Wucula-like, with extended anterior and posterior ends,
and more or less defined depression along the umbonal slope.
Ligament external and contained in narrow groove along the car-
dinal border. Pallial line simple.

Differs from Mucula, Leda and Yoldia in the absence of a resili-
fer beneath the beak and in having an external ligament and a
post-umbonal depression externally. Differs from Nucu/ites inthe
absence of the internal anterior ridge. Devonic—Triassic.

84. P. muta Hall. (Fig. 510, g-z.) | Devonic.
Varying in outline from more to less elongate, and thus resem-

i a i i a i i i a i ee i A be ee ees, ee
. r ‘

PELECYPODA—PRIONODESMACEA. 399

: .
bling both P. tenuistriata and P. fecunda. Differs from both in
the strong, lamellose strize with very fine striz intermediate.
Hamilton Group: New York, Pennsylvania, Virginia.

85. P. tenuistriata Hall. (Fig. 510, c.) Devonic.
Large, ovate, doubly truncate posteriorly. Surface marked with
fine and often crowded concentric striz.
Very abundant in the Hamilton of New York, etc.

86. P. fecunda Hall. (Fig. 510, &, 2.) Devonic.
Differs from PP. tenustriata in its more elongate outline and
coarser striz, while in P. muta the strie are still stronger, being
coarse and lamellose.
Hamilton Group: New York, Virginia, Wisconsin ?

87. P. plana Hall. (Fig. 510, /) Devonic.

Fic. 510. a, b, Paleoneilo constricta (natural size and enlarged); c, P. ¢emuzstriata,
right valve; d, P. brevis; e, P. marshallensis, right valve; f, P. plana, enlarged;
g-t, P. muta, 2 \eft and 1 right valve; 7, P. sulcatina; k, 1, P. fecunda; m-p,
neaemerginala, (Pal. N. Y., V.)

400 NORTH AMERICAN: INDEX #OSSEIDS.

Differs from P. constricta in its smaller size and more elongate
form.

Common in Hamilton of New York, Pennsylvania and Ontario.
Marcellus: New York. Ithaca: New York, Pennsylvania.

88. P. emarginata (Conrad). (Fig. 510, mp.) Devonic.
Posterior margin deeply emarginate owing to the strongly
marked ridge and depression on the umbonal slope. Concentric
striz strengthened into distant lamellose ridges with finer striz
between.
Hamilton: New York and Appalachian region. Portage:
New York.

89. P. constricta (Conrad). (Fig. 510, a, 0.) Devonic.
Basal margin rounded anteriorly and slightly constricted pos-
teriorly. Surface striz thread-like, often obsolescent.
Hamilton: Appalachian and interior regions. Portage and
Chemung of New York and Pennsylvania.

90. P. brevis Hall. (Fig. 510, d.) Devonic.
Similar to P. constricta in general outline but is more gibbous,
less curved along the basal margin, and only very slightly con-
stricted posteriorly.
Chemung: New York, Pennsylvania.

gi. P. marshallensis Winchell. (P. truncata Hall.) (Fig. 510, 2.)

Mississippic.

Distinguished by the nearly parallel basal and cardinal margins,

the short anterior portion, the truncate posterior margin, and the

fine striz, which though in parts crowded do not rise into varices.
Waverly of Ohio: Marshall group of Michigan.

92. P. sulcatina (Conrad). (Fig. 510, 7.)
Upper Devonic and Mississippic.
Valves gibbous, regularly rounded, with no marked truncation
or constriction. Concentric elevations sharp and lamellose inter-
spersed with finer concentric striz.

Chemung: Iowa. Waverly: Ohio, Michigan.
XXIX. Lepa Schumacher. (JVuculana Link.)

Porcelainous, often somewhat crescent-shaped and produced
posteriorly. Rounded anteriorly. Beaks often tumid, turned pos-
teriorly. Surface concentrically striated. Hinge with a line of

PELECYPODA--PRIONODESMACEA. 401

minute teeth, interrupted at beak by a triangular resilifer. Muscle
impressions two and small. Pallial sinus small. Differs from
Nucula in its more porcelainous structure, the presence of a pallial
sinus and in the usually entire margins of the valves ; also differs
usually in outline. Siluric—Recent.

93. L. rostellata (Conrad). (Fig. 511, @.) Devonic.
Very small. Differs from Z. diversa in its more elongate out-
line, more recurved posterior extremity, and finer striz.
Hamilton: New York, Pennsylvania, Ontario. Portage: Penn-
sylvania.

94. L. diversa Hall. (Fig. 511, c.) Devonic—Mississippic.
Very small. Length about twice the height.
Hamilton and Portage of New York and Pennsylvania. Bed-
ford shale of Ohio.

95. L. pandoriformis Stevens. (Fig. 511, a, 0.) Mississippic.

Fic, 511. a, 6, Leda pandoriformis; c, L. diversa; d, L. rostellata, c and d
enlarged, (2. “(Pals N. ¥.,°¥.,.}
Large, with posterior extremity attenuate but subtruncate at its
end.
Waverly: Ohio, Michigan.
96. L. bellistriata Stevens. (Fig. 512, a, 4.)
Mississippic—Permic.
Large. Surface covered with fine and regular concentric striz.

ss

: ; ——— 7 I
Fic, 512. a, 6, Leda bellistriata (Ind. Surv.); c, Leda parva, right valve
(Md. Surv. ). )

Widely distributed in the Carbonic from Ohio to Colorado.
Also in Mississippic of Tennessee (Waverly Group) and Michigan
(Marshall Group). Upper and Lower Permic of Kansas.

402 NORTH AMERICAN INDEX FOSSILS.

97. L. parva (Rogers). (Fig. 512, c.) Eocenic.
Minute (length about { inch). Sharp oblique sulcus and sharp
concentric lines present.
Atlantic and Gulf regions.

98. L. eborea Conrad. (Fig. 513.) Eocenic.
Distinguished by its almost triangular and
Fig. 513. Lede eborea. equilateral form. Surface smooth and pole
re ee ished. Length usually about 3 inch.
Abundant in Midwayan of Gulf region.

XXX. YouprA Moller.

Compressed, lanceolate, gaping behind, and more or less pro-
longed and tapering posteriorly. Beaks turned backward. Sur-
face nearly smooth. Hinge as in Nucula. Pallial sinus deep.
Differs chiefly from Leda in the gaping valves and in the deep pal-
lial sinus. Cretacic—-Recent.

gg. Y. septariana Cragin. Cretacic.
Elongate, subovate, with beaks anterior to middle. Hinge line
sloping abruptly on both sides from the beaks. Teeth 16—20 in
front of the beaks and 21-29 behind. Surface marked with con-
centric lines. Length 3 inch; height 2 inch. |
Very abundant in septaria of the Benton (Eagle Ford) of Texas.

100, Y. evansi Meek and Hayden. (Figs. 514-515.) Cretacic.

Fic. 514. Yoldia evanst, internal Fic. 515. Yoldia evansz (upper),
mold showing pallial sinus and left valve; Y. scztula (lower),
hinge-denticles. (After Meek.) left valve. (After Meek. )

Outline similar to that of Y. longifrons but the shell is smaller
(length not exceeding. 4 inch), and the surface is more nearly
smooth, the concentric strize being very obscure.

Fox Hills : South Dakota, Montana, Assiniboia. Pierre: Mon-
tana (Claggett), North Dakota (Bearpaw). Also Wyoming.

PELECYPODA—PRIONODESMACEA. 403

101. Y. longifrons (Conrad). (Fig. 516.) Cretacic.

Fic. 516. Yoldia longifrons ; with enlargement of hinge. (N. J. Pal., I.)
Surface of shell polished, marked only by fine concentric growth
lines. .
Ripleyan of New Jersey (Woodbury), Mississippi, Arkansas.

102. Y. scitula Meek and Hayden. (Fig. 515.) Cretacic.
Smaller than Y. /ongifrons (length about 2 inch) and marked
with distinct and regular concentric lines, which are strong on the
middle of the valves.
Fox Hills: South Dakota, Montana. Pierre: Montana. Mon-
tanan: Assiniboia.

XXXII. PARALLELODON Meek and Hayden.

Elongate to subquadrate. Anterior end angular at cardinal line
and rounded below. Posterior end rounded or obliquely subtrun-
cate. Beaks anterior to middle. Hinge line long and straight.
Concentric strize often lamellose. Hinge with several small, diverg-
ing teeth beneath the beak and two to four long, lateral teeth
near the posterior extremity, Ligament external. Pallial line
simple. Devonic—Tertiary.

103. P. chemungensis Hall. (Fig. 517, a.) Devonic.

Nye

Fic. 517. @, Parallelodon chemungensis, left valve; 6, c, P. hamiltonia, right
valve and internal mold with valves in conjunction, (Pal. N. Y., V.)
Distinguished by its narrow form, truncated posterior end, and
anterior constriction of the base. Concentric lines irregular and
lamellose.
Chemung: New York, Pennsylvania.

104. P. hamiltonie Hall. (Fig. 517,0,c.) Devonic—Mississippic. »
Differs from P. chemungensis in its broadly rounded posterior

404 NORTH AMERICAN INDEX FOSSILS.

end, the absence of a sharp constriction in the basal margin, and
in the presence of regular concentric varices.

Abundant in Hamilton: New York, Penn-
sylvania, Maryland, Ohio. Mississippic:
Ohio, Nevada.

Fic. 518. Parallelodom 105. P. tenuistriatus Meek and Worthen.
obsoletus. (Kan. Pal., Mississippic and Carbonic.
red Strong radiating lines, scarcely visible ante-

riorly. Umbo large ; anterior end rounded ; length 3 inch.
Waverly : Ohio. Coal Measures of Ohio—Nevada.

106. P. obsoletus Meek. (Fig. 518.) Mississippic—Carbonic.
Base a little sinuate medially and nearly parallel with the hinge

line.
St. Louis of Indiana. Coal Measures of West Virginia—Colorado.

XXXII. Nemopon Conrad.

Equivalve, thin, small, transversely elongate, with sinuous base.
Beaks depressed and anterior to middle. Hinge area narrow, long
and nearly straight. Teeth consisting of a few minute granular
denticles directly under the beak ; lateral teeth few, long, linear,
parallel to the hinge margin. Laterals longer than in Cucudllea.

Fic, 519. Memodon brevifrons, with enlargement of cardinal region. (N. J. Pal., I.)

Surface marked with very obscure, punctate, radiating striz and
concentric lines.
Distinguished from Arca and Parallelodon by its teeth. Cretacic.

107. N. vancouverensis Meek. Cretacic.
Hinge and basal margins nearly parallel. Posterior end rather
squarely truncate and the two extremities nearly equal in breadth.
Length of small specimen ? inch ; height } inch. Surface marked
with numerous prominent radiating ribs. Umbo much larger and
more elevated than that of VV. drevifrons.
Horsetown : California, Oregon. Chico: California, Vancouver.

PELECYPODA—PRIONODESMACEA. 405

108. N. brevifrons Conrad. (Fig. 519.) Cretacic.
Radiating lines nearly obsolete. Umbonal ridge rounded.
Ripleyan of New Jersey (Cliffwood, Wenonah ?), North Carolina,

Mississippi.

109. N. eufalensis (Gabb). (Fig. 520.) Cretacic.

Fic. 520. Nemodon eufalensis, with cardinal margin enlarged. (N. J. Pal., I.)

Valves marked with a mesial depression, producing a slight
emargination of the base. Radiating striz fine and numerous.

Ripleyan of New Jersey (Merchantville-Tinton), Georgia, Ala-
bama, Mississippi, Arkansas.

110. N. sulcatinus Evans and Shumard. Cretacic.
Similar to WV. eufalensis in outline but very small (length slightly

over 4 inch) and with mesial depression broad and deep.
Coloradoan: Utah, South Dakota. Montanan: Montana.

SRM: Cuocuri@s Tamarek:

Similar to Avca but hinge with short central transverse or
oblique teeth and two to five short lateral teeth nearly parallel to
the hinge line. Posterior adductor scar fixed to a thin raised plate.

The subgenus /donearca includes in general the forms with
thicker shells and fewer teeth than the typical Cucu//l@a. Jurassic
—Recent.

111. C. vulgaris Morton. (Fig. 521.) Cretacic.

Fic. 521. Cucullea vulgaris, internal molds. (N. J. Pal., I.)

Its internal molds differ from those of C. “#ppana in being more
oblique, with longer beaks.

406 NORTH AMERICAN INDEX. FOSSIES.

Jerseyan of New Jersey (characteristic of the Hornerstown
marl), Maryland (Monmouth).

Fic. 522. Cucullea tippana. (N. J. Pal., I.)

112. C. tippana Conrad. (Figs. 522-523.) : Cretacic.

Basal margin nearly straight ; pos-
terior obliquely truncate.

Ripleyan of New Jersey (Marshall-
town—Tinton), Texas (Navarro), Mis-
sisSippl.

113. C. neglecta Gabb. Cretacic.

Smaller than C. “ppana with more
rounded outlines.

Ripleyan of New Jersey (Merchant-
ville and Navesink), Alabama.

Fic. 523. Cucullea tippana, inte-
rior of valve. (N.J.Pal.,I.) 114. C. antrosa Morton. (Fig. 524.)

Cretacic.

Fic. 524. Cucu/lea antrosa, internal molds. (N. J. Pal., I.)

PELECYPODA—PRIONODESMACEA. 407

Subglobose. Its internal molds differ from those of C. zppana
in the more rounded outline and usually larger size.

Ripleyan of Arkansas, Texas, New Jersey (characteristic espe-
cially of the Merchantville, also occurs in the Navesink).

115. C. truncata Gabb. Cretacic.
Differs from C. gigantea in the narrower and more pointed and
upright, nearly central beaks.
Chico: California, Oregon.

116. C. gigantea Conrad. (Fig. 525.) Eocenic.
Varying much in size. Surface covered with numerous
radiating strize and concentric growth lamelle.

Fic. 525. Cucullea gigantea, \eft valve from within and without, ¥%.
(Md. Surv.)

Throughout the Eocenic of Maryland and Virginia; Lignitic of
Gulf states.
XXXIV. Triconarca Conrad.

Differs from Czcullea in its somewhat trigonal form, obliquely
truncated posterior margin, and somewhat angular posterior basal
extremity. Hinge curved. Teeth radially arranged. Hinge
area divaricately furrowed. Cretacic and Tertiary.

117. T. obliqua Meek. (Fig. 526, a—e.) Cretacic.
Beaks small, depressed. Posterior umbonal slope prominent.

Both muscle impressions are bordered by elevated ridges.
Coloradoan : Colorado (Pugnellus sandstone), Utah.

XXXV. BreEviARcA Conrad.

Small, suborbicular, with more or less rounded extremities.
Surface nearly smooth or marked only with fine radii. Hinge

408 NORTH. AMERICAN INDEX FOSSILS.

Tee
SS SOK aS >
WSS

SEG

~
Lorne

Fic. 526. TZyrigonarca obliqua, a, left valve of a large specimen; 4, internal mold
of left valve ; d, posterior view of same, shell on right valve ; ¢c, dorsal view of a smaller
specimen; ¢, hinge of right valve. (After Stanton. )

area with minute vertical striz. Denticles very fine and crowded.
Cretacic.

118. B.? siouxensis (Hall and Meek). Cretacic.

Anterior border vertically subtruncate but convex along the
middle and rounding rather abruptly into the base and hinge line.
Posterior side abruptly truncate above, narrowly rounded below.
Beaks subcentral, nearer
the posterior end, slightly
or not at all oblique.
Distinguished from other
species by its large size
(length nearly one inch
and height slightly less)

and by its straight basal
Fic, 527. Sreviarca saffordi, enlargement of margin.
hinge and exterior natural size. (After Whitfield, Dakotan: South Da-

Pal i 7h) é
oy kota, Texas (Woodbine),
119. B. saffordi (Gabb). (Fig. 527.) Cretacic.

Surface covered with fine radiating striz.
Ripleyan of New Jersey (Woodbury), Tennessee.

PELECYPODA—PRIONODESMACEA. 409

120. B. exigua (Meek and Hayden). Cretacic.
Is proportionally higher, shorter and more gibbous than BZ.
saffordi, but of about same size.
Pierre : Montana, South Dakota.

XXXVI. Cyrtoponta Billings.

Equivalve. Shell convex, usually heavy. Beaks prominent,
incurved, situated in the anterior third of the shell. Surface
marked with concentric lines. Hinge plate strong. Cardinal
teeth two to four, strongly curved, situated mostly in front of the
beaks. Posterior lateral teeth two or three, strong, elongate,
slightly curved and oblique. Two adductor scars present; the

Fic. 528. a-c, Cyrtodonta subovata; d, e, C. billingsi. (Minn. Surv.)

posterior the larger but less impressed. Pallial line simple. Or-
dovicic and Siluric.

121. C. billingsi Ulrich. (Fig. 528, d, ¢.) Ordovicic.
Internal umbonal furrow and
ridge present.
Upper Stones River: Illi-
nois, Wisconsin, Minnesota.

122. C. grandis Ulrich. (Fig.
529.) Ordovicic.
Large. Surface smooth,

marked with fine concentric ‘ o :

growth fra: IG. 529. a ae “pa IS ee jas
Trenton and Cincinnati

Groups: Pennsylvania, Kentucky, Tennessee, Wisconsin, Minne-

sota, lowa.

a)

410 NORTH AMERICAN INDEX FOSSILS.

123. C. subovata Ulrich. (Fig. 528, a—c.) Ordovicic.
Hinge rather short. Surface nearly smooth, but with age de-
veloping strong marginal growth lines.
Upper Stones River of Kentucky. Black River of Wisconsin.

124. C. undulostriata Hall. Siluric.
Surface marked with strong concentric folds, covered with fine
undulating concentric striz.
Rochester shale of New York.

125. C. canadensis (Hall). (Megalomus canadensis Hall). (Fig.
(ovr ae Siluric.
Shell extremely thick, ovoid, its depth equal to its height. Sur-

face concentrically striated. The space within the shell, beneath

Fic. 530. Cyrtodonta ( Megalomus) canadensis, internal mold. (After Logan. )

the beaks and extending over half way to the base of the valves
is very much thickened so that an internal mold shows two pro-
jections at the hinge line instead of the single one of the beak as
usual in Cyrtodonta.

Guelph : Ohio, Wisconsin and Ontario.

XXXVII. MecGamsonia Hall.

Equivalve or nearly so, gibbous, inequilateral, with shorter
anterior end which bears astrong muscularimpression. Posterior
extremity expanded and compressed, frequently wing-like. Sur-
face marked with concentric growth lines and often with fine
radiating strie. Teeth numerous, in the anterior portion of the
hinge.

PELECYPODA—PRIONODESMACEA. 4II

Differs from Amdbonyciia in the strong anterior muscular impres-
sion and the numerous teeth in the anterior portion. Siluric—Car-
bonic.

126. M. lata Hall. Devonic.
Anterior slope oblique; posterior basal margin expanded.
Gibbous in the middle and in the umbonal region.
Helderbergian : New York, Oklahoma.

127. M.? aviculoidea Hall. (Fig. 531.)
Upper Siluric and Lower Devonic.

Surface marked with fine concentric strize
which are unequally lamellose. This may
be a Pterinea.

Distinguished from similar species of
other genera by the very small anterior ear,
the strong anterior muscle scar characteristic
of the genus, and the posterior wing, not de- FS: 53%. Afegambo-

; nia? aviculoidea, eft
fined from the rest of the shell by sinus or ,.),, (Pal. N. Y., 11.)
change of ornamentation.

Manlius : New York, New Jersey. Helderbergian : New York.

128. M. suborbicularis Hall. (Fig. 532.) Devonic.
Anterior muscular impression prominent on internal molds.
Type of the genus.
New Scotland: New York.

b.

Fic. 532. Jlegambonia suborbicularis, a, left side of internal mold showing muscular
impression ; 4, profile of posterior side of same. (Pal. N. Y., III.)

129. M. ovata Hall. Devonic.
Distinguished by its nearly symmetrically ovate form with the

412 NORTH AMERICAN ANDEX - FOSSILS.

anterior side a little more regularly curved than the posterior, and
by the subacute beak.
New Scotland: New York.

130. M.? lamellosa Hall. (Fig. 533.) Devonic.
Both ears separated from the body of the shell by a depression.
Lamellose striz more or less prominent.
Oriskany : New York—Maryland.

Fic. 533. Megambonia ? lamellosa. (Pal. N. Y., III.)

XXXVIII. OrTONELLA Ulrich.

Equivalve, very inequilateral. Beaks and umbonal ridge mod-
erately prominent. Surface marked with concentric strie. Hinge
like that of Cyrtodonta but with cardinal teeth stronger and
placed immediately behind the beaks. Adductor scars subequal.
Ordovicic.

131. O. hainesi S. A. Miller. (Fig. 534.) Upper Ordovicic.
Concentric striz fine. Umbonal ridge rather strong. Type of
the genus. Uppermost beds of Cincinnati Group of Indiana.

; XXXIX. Vanuxemia Billings.

Differs from Cyrtondonta in the more nearly terminal beaks, and
in the anterior adductor muscle scars being excavated out of
the hinge plate. An internal umbonal ridge is well developed.
Ordovicic.

-

PELECYPODA—PRIONODESMACEA. 413

Fic. 534. Ortonella hainest. (Ohio Geol., VII. After Ulrich. )

132. V. terminalis Ulrich. (Fig. 535, g-z.) © Ordovicic.
Beaks terminal. Anterior muscle scars almost hidden.
Upper Stones River of Wisconsin, Minnesota.

FIG. 535. a—c, Vanuxemia dixonensis ; d—f, V. umbonata, right and cardinal views ;
gi, V. terminalis, internal molds, left, right and anterior views ; 7, V. rotundata; hk,
V. hayniana, right internal mold. (Minn. Surv.)

414 NORTH AMERICAN INDEX FOSSILS.

133. V. dixonensis Meek and Worthen. (Fig. 535, a-c.)

Ordovicic.
More oblique, more convex, and with more rounded hinge ex-
tremities than V. umbonata.

Upper Stones River of Illinois, Wisconsin, Minnesota.

134. V. rotundata Hall. (Fig. 535, 7.) Ordovicic.
More erect, with more circular outline than V. dzxonensis.
Upper Stones River of Wisconsin, Minnesota ?

135. V. umbonata Ulrich. (Fig. 535, ad) Ordovicic.
Shell substance rather thin. Cardinal teeth long.
Black River: Kentucky, Minnesota.

136. V. hayniana Safford. (Fig. 535, 2.) Ordovicic.
Not so high as V. wmbonata and with longer hinge line,
Trenton: Pennsylvania, Kentucky, Tennessee, Minnesota.

XL... -\WHtrecea > Ulrieh:

Differs from Cyrtodonta in its thinner shell, the presence of a
longitudinally striated area extending posteriorly from the beaks, an

Fic. 536. a, 4, Whitella scofieldi, left valve and its hinge; ¢, d, W. guadran-
gularis; e, f, W. ventricosa, right and anterior views of internal mold. (Minn. Surv. )

PELECYPODA—PRIONODESMACEA. 415

umbonal ridge, anterior teeth merely two to five oblique folds and
posterior lateral wanting ; internal ligament supported by a ridge
in each valve which is at times mistaken for a posterior tooth,
Ordovicic-Siluric.

137. W. megambona Whitfield. (Fig. 537, a, 0.) Ordovicic.
Hinge line very short. Striated area very short and narrow.
Upper Stones River of Wisconsin, Minnesota.

138. W. scofieldi Ulrich. (Fig. 536, a, 0.) Ordovicic.
Outline different and hinge and striated area longer than in W.
megambona.

Upper Stones River of Minnesota.

f Fic. 537. a, 6, Whitella megambona, right valve; c, W. obliguata, left internal
mold; a-/, Plethocardia umbonata. (Minn, Surv.)

139. W. ventricosa Hall. (Fig. 536, ¢, 7) Ordovicic.
_ Very convex.
Black River<Trenton: New York, Minnesota ?, Canada.

140. W. obliquata Ulrich. (Fig. 537, c.) Ordovicic.
Subquadrangular, very oblique.
Cincinnati Group: Ohio, Indiana, Minnesota.

141. W. quadrangularis Whitfield. (Fig. 536, c, a.) Ordovicic.
More convex, less oblique, than W. obliquata with larger beaks
and wider cardinal area.
Upper beds of Cincinnati Group : Ohio, Illinois, Minnesota.

416 NORTH AMERICAN INDEX FOSSILS.

AL PLETHOCARDIA: Ulnch

Very similar to Wiitella but differs from that genus in the large
and strong cardinal process which projects forward and downward
from just beneath the beak in each valve ; also differs in the deeply
impressed anterior adductor scar mar-
gined on the inner side by a curved
ridge extending from the under side of
the cardinal process. Ordovicic.

142. P. umbonata Ulrich. (Fig. 537,
af.) Ordovicic.
Type of the genus.

Black. River: New York, Ken-
tucky, Minnesota.

XLII. Iscuyroponta Ulrich.

Valves thick. Beaks small, ante-
rior. Hinge plate wide, without pos-
terior lateral teeth but with two strong
cardinal teeth in the left valve and one

Fic. 538. Jschyrodonta union. large one in the right. Ligament in-

oides, interior and internal mold; ternal posterior tothe beaks. Anterior
exterior of right valve. (Geol.
Ohio, VII. )

muscle scar sharply defined on the in-
ner side by a ridge extending from
the cardinal teeth to the base of the scar. Ordovicic.

143. I. unionoides Meek. (Fig. 538.) Ordovicic.
Surface marked with a few distant growth lines.
Middle beds of Cincinnati Group: Ohio, Kentucky.

144. I. modioliformis Ulrich. (Fig. 539.) Ordovicic.
Elongate. Surface marked with sub- |
regular concentric furrows and ridges. |
Upper beds of Cincinnati Group: Indi-
ana.

is: 1. truncata Ulrich. (Pf i¢g.-540.)
Ordovicic.
Subquadrate. Posterior margin trun-

FIG. 539. Lschyrodonta
modioliformis. (After Ulrich,
cate rounded.. Surface marked with a Geol. Ohio, VII.)

few sublamellose growth lines.
Near top of Cincinnati Group:: Ohio, Indiana.

PELECYPODA—PRIONODESMACEA. 417

Fic. 540. J/schyrodonta truncata. (After Ulrich, Pal. Ohio, VII.)

XLIII. Arca Lamarck.

Shell thick, ventricose, trapezoidal. Beaks conspicuous, distant,
separated by an area which has many ligamental grooves con-
verging from the hinge margins to the beaks.
Surface radially sculptured. Hinge line wide,
straight, transversely dentate; teeth small

and similar (taxodont). Cretacic—Recent. cane ee eee
This has been divided into several subgen- Cie nk ee

era of which Aarbatia is one. Pal, RT, To
146. A. quindecemradiata Gabb. (Fig. 541.). Cretacic.

Rather small, ventricose and very inequilateral ; anterior round-
ing rapidly into basal margin; beaks slightly incurved, a little in
front of the mid-length of the hinge line; obliquely truncate
posteriorly ; surface with coarse rounded ribs.

Jerseyan (Vincentown) of New Jersey. 7

XLIIIa. Barzatia (Gray) Adams.

Central teeth smallest and vertical; lateral teeth becoming
gradually larger, more distant, and more oblique. Periostracum
hairy. Cretacic—Recent.

147. B. micronema (Meek). (Fig. 542.) Cretacic.

Growth and radiating lines faint. Beaks in anterior fourth.

Colorado Group of Wyoming, Utah, Texas. Dakota of Texas.

148. B. cuculloides (Conrad). Eocenic—Oligocenic.
Valves marked with strong, subcentral sinus. Posterior side
elongated, strongly ribbed, and carinated ; anterior end truncate.
Surface reticulate by strong growth lines passing over the
radiating ribs.
Eocenic: Georgia, Alabama, Mississippi, Arkansas, Lower
Oligocenic: Mississippi.

418 NORTH AMERICAN INDEX FOSSILS.

TEED
mae

Lf
OT
Lhe

Y fod
bide

agen PERE) UE

wie

Fic. 542. Barbatia micronema, right valves. (U.S. G. S., Bull. 106.)

XLIV. Grycimeris Da Costa. (Pectunculus Lamarck.)

Shell thick, equivalve, suborbicular, almost equilateral. Umbos
central, slightly curved posteriorly, separated by a small triangular
area provided with diverging grooves for the ligament. Hinge
with an arched row of strong, transverse teeth, obliterated at the
center in older forms by the growth of the area. Margins of
valves crenulate inside. Adductor scars subequal. Pallial line
with a very small sinus. Cretacic—Recent.

149. G. (Axinea) subaustralis (d’Orbigny). (Fig. 543.) Cretacic.
Subcircular, very slightly oblique. Beaks strongly elevated

Fic. 543. Glycimeris (Axinea) subaustralis. (N. J. Pal., I.)

and pointed. Surface covered with concentric growth lines and
fine radiating coste.
Ripleyan of New Jersey (Merchantville—Tinton), Gulf states.

.

PELECYPODA—PRIONODESMACEA. 419

150. G. congesta (Conrad). Cretacic.
Differs from G. subaustrals in its smaller size, more elliptical
form, and straighter hinge line.
Ripleyan of New Jersey (Cliffwood—Wenonah), North Carolina.

Fic. 544. Glycimerts idonea, X 2. (Md. Surv.)

151. G. idonea (Conrad). (Fig. 544.) Eocenic.
Larger. Surface marked with obscure radiating striz.
Pamunkey of Maryland, Lignitic of Georgia and Alabama.

XLV. PTERINEA Goldfuss.

Inequivalve, very inequilateral. Left valve convex ; right valve
flat. Hinge margin constricted into ears. Surface radially
sculptured or smooth. Ligmental area extending on both
sides of the beak and longitudin-
ally grooved. Anterior teeth trans-
verse; posterior elongate, nearly
parallel to the hinge line. Anterior
muscle scar small. Pallial line
simple. Ordovicic—Carbonic.

152. P. demissa (Conrad). (Fig.

545.) Ordovicic.

Distinguished by its strong con- © Fig, 545. Lterinea demissa, (Geol.
centric growth lines and large an-_ Ohio, II. )
terior ear.

Cincinnati Group: New York—Iowa ; Wisconsin.

153. P. emacerata (Conrad). (Fig. 540.) Siluric.
Right valve flat, smooth, with striated wing. Left valve convex,
with strong radii crossed by concentric striz.

420 NORTH AMERICAN INDEX / FOSSILS.

Clinton and Niagara: New York, New Jersey (Decker Ferry),
New Hampshire ?
154. P. striecosta McChesney. (P. dvisa Hall.) Siluric.

Surface marked with strong, radiat-
ing and concentric strie and broad
radiating ribs.

Clinton: Ohio, Indiana, Kentucky.
Niagaran : Indiana, Wisconsin.

155. P. lanii Grabau. (Fig. 547.)
Siluric.
Strongly oblique, surface with con-
centric striz only.
Lower Monroe (Raisin River) of Michigan, Ohio and Canada.
156. P. securiformis (Hall). (Fig. 548.)
Upper Siluric-Lower Devonic.
Shell convex. Anterior ear practically ab-
sent; posterior small. Surface covered with
iy

concentric striz and distant strong radiating *!G. 547. Lverinea
laniz, left valve of a

ones. mee 2
: : small individual. (Af-
Cobleskill: New York. Helderbergian : ter whitfeld.)

New York, Oklahoma.

157. P. naviformis (Conrad). (Fig. 549.) Devonic.

Similar to Actinopteria com-
munis but differs in its much
larger posterior ear and in its
obscure radiating and concen-
tric striz.

Helderbergian : New York,
Gaspé.

158. P. gebhardi (Conrad).
(Fig. 550.) Devonic.
Large, suborbicular. Left

valve marked with about 15

3 - slightly impressed radiating

Fic. 548. Lterinea securtformis. (Pal. N. grooves, forming faint, wide

i lana, : and convex ribs. Ears equal,
not produced. Height about 5 inches.
Oriskany: New York.

Fic. 546. Pterinea emacerata.
(Palo Ny Vat.

SS = ir”, =

PELECYPODA—PRIONODESMACEA. 421

159. P. (Cornellites) flabellum (Conrad). (Fig. 551.) Devonic.

Left valve with beak curving to or over the hinge margin. Sur-
face marked with 6-12 strong ribs alternat-
ing with one to several weaker rays, the
latter present also on the ears. Right
valve with beak depressed, not rising above
the hinge; surface lacking rays except
weak ones on the posterior ear. Both
valves crossed by concentric growth lines.

Fic. 549. Pterinea navi-

on. formis, left valve. (Pal. N.
Characteristic of the Onondaga and V. IL.) (

Hamilton of New York to Indiana, Michi-
gan, Ontario and the Appalachian region; also rarely in the Che-
mung Group of the same region.

Fic. 550. terinea gebhardi, x}. (After Hall, Pal. N. Y., III.)

160. P. chemungensis (Conrad). (Fig. 552, a, 0.) Devonic.

Surface of left valve marked with slender, interrupted, irregularly
alternating rays which on the right valve are confined to the ears.
Surface of both valves crossed by fine concentric striz. Valves
are often less oblique than in figure.

Chemung Group: New York.

422 NORTH‘ AMERICAN _ INDEX* FOSSILS:

161. P. consimilis Hall. (Fig. 552, ¢.) Devonic.
Differs from P. chemungensis in being shorter, proportionately
more extended on the hinge line, with wider ligamental area, more
distinct rays, and greatly different proportions of length and
breadth.
Chemung Group: New York.

XLVI. Limorrera Hall.

Differs from Pterznea in the less conspicuous separation of the
posterior wing from the body of the shell, and in the numerous

Fic. 551. Pterinea (Cornellites) flabellum. (Pal. N. Y., V.)

small pits for the attachment of umbonal muscles in the inter-pallial
area. Pallial line also formed of a series of small deep pits.
Devonic.

162. L. cancellata Hall. (Fig. 552, c, d@.) Devonic.
Body of shell nearly vertical to hinge line. Surface covered
with regular sharp concentric striz and crossed by narrow rays
separated by broad flat interspaces.
Hamilton of Falls of the Ohio.

163. L. macroptera (Conrad). (Fig. 553, d@.) Devonic.
Right valve much less convex than left. Anterior ear very
small. Surface marked with rays which become obscure below
the middle of the shell. Concentric striza lamellose.
Hamilton: New York, Ontario.

164. L. obsoleta Hall. (Fig. 553, ¢.) Devonic.
Differs from L. macroptera in its less convexity, less angular

posterior ear and in the rays being absent or very obscure.
Hamilton: New York.

PELECYPODA—PRIONODESMACEA. 423

Fic. 552. a, 6, Pterinea chemungensts, right and left valves; c, Lzmoptera can-
cellata; d, surface of left valve of ZL. cancellata, enlarged; e, Pterinea consimilis,
femwalve. @,5,cande,< 2. (Pal. N. Y., V.)

XLVII. Acrinopesma Sandburger. (G/yptodesma Hall.)

Like Pterinea but with wings elongate and narrow and less
strong limitation between body of shell and wing. Surface con-
centrically striated. Devonic.

165. A. occidentale (Hall). (Fig. 553, c.) Devonic.
Differs from A. evectum in its more orbicular shell, more gibbous
umbonal region, more rugose concentric striz, and less strong
limitation between the body of the shell and the much extended
posterior wing.
Onondaga: Falls of the Ohio.

166. A. erectum (Conrad). (Fig. 553, a, 4.) Devonic.
Anterior wing limited by a distinct furrow. Surface covered
with concentric striz which are more conspicuous upon the ears.
Hinge line often greatly extended.
Hamilton: New York, Ohio, Indiana.

424 NORTH AMERICAN INDEX FOSSILS.

FIG. 553. @, 6, Actinodesma erectum, right and left valves; c, A. occidentale; d, Lim-
optera macroptera,; e, L. obsoleta. All figures, 3. (Pal. N. Y., V.)

XLVIII. Leropreria Hall.

Outline /verinea-like. Ligament area longitudinally striated.
One or two oblique lateral teeth present. Cavity of beak partially
separated from the anterior end by a short partition. Surface

without rays. Siluric—Mississippic.

167. L.? subplana (Hall). (Fig. 554.)
+s Silane
Depressed-convex. Right and left
valves similar. Ears poorly defined.
Rochester and Cobleskill of New
York. Guelph: New York, Canada.

168. L. levis Hall. (Fig. 555, a, 3.)
Devonic.
Length and height nearly equal.
Anterior ear marked by a strong, an-
gular fold. Surface covered with ob-
scure traces of radiating strie.
fig ey Piper? wclabonn. Marcellus and Hamilton: New York,
left valves. (Pal. N. Y., 11.) Pennsylvania.

PELECYPODA—PRIONODESMACEA. 425

169. L. rafinesquii Hall. (Fig. 555, c.) Devonic.
Anterior ear broadly arched. Surface covered with concentric
striz which at intervals are raised into strong lamellze and undula-
tions.
Hamilton: New York, Ontario. Lower Devonic of Nevada.

170. L. dekayi Hall. (Fig. 555, 2.) Devonic.
Differs from L. /gvzs in its larger size and more defined posterior

cardinal slope; from L. rafinesquiz in its finer and not lamellose

striz though concentric undulations are at times present.
Characteristic of the Hamilton of New York.

Fic. 555. a, 6, Leiopterta levis right and left valves, « 2; e ae iat gs d,
Li apkayi, &, 2. chemungensiss) (Pai. N.Y, Vi)

171. L. chemungensis Vanuxem. (Fig. 555, 2.) Devonic.
Differs from ZL. dekayz in its longer hinge line, larger posterior

ear, more acute beak, and narrower body of shell. |
Chemung of New York, etc.

XLIX. Lepropgesma Hall.

Differs from Lezopterta in its acute instead of rounded anterior
ear ; lateral tooth single and nearly parallel to hinge line.
Devonic.

426 NORTH AMERICAN INDEX FOSSILS.

172. L. rogersi Hall. (Fig. 556, 2.) Devonic.
Umbonal region gibbous. Posterior ear with mucronate ex-
tremity.
Hamilton : New York, Pennsylvania, Iowa.

173. L. sociale Hall. (Fig. 556, c.) Devonic.
Distinguished by its form and regular lamellose appearance of
the surface.
Chemung: New York.

174. L. maclurii Hall. (Fig. 556, a.) Devonic.
Body of shell gibbous, oblique. Anterior ear limited by a broad,
vertical furrow.

Chemung: New York, Pennsylvania.

Fic. 556. a, Leptodesma maclurit, \eft valve; 4, L. rogerst; c, L. sociale; ad, é,
Lunulicardium curtum, right and left valves; /-7, Pterochenia fragilis; j, Lunuli-
cardium acutirostrum, left valve. (Pal. N. Y., V.)

L. LoxoptTeriaA Frech.

Inequivalve, very inequilateral. Anterior muscle scar small.
Ligament external. Teeth obscure.
Appearance like the gastropod Capulus. Left valve very con-

bo a,

PELECYPODA—PRIONODESMACEA. 427

vex, with arched and incurved beak twisted backward. Right
valve depressed-convex, appearing like the operculum of the larger
valve ; this valve expands into a small posterior wing. Devonic.

175. L. levis Frech. (Fig. 557.) Devonic.
Surface marked only with concentric striz.
Portage (Naples fauna) of New York.

Fic. 557. Loxopteria /evis, right valve Fic. 558. Loxopteria dispar, left valve
(upper), <2; left valve, 1.5. (After (upper), X1I.5; right valve, <2. (After
Clarke, Mem. 6, N. Y. State Surv. ) Clarke, Mem. 6, N. Y. State Surv. )

176. L. dispar (Sandberger). (Fig. 558.) Devonic.
_ Surface marked with few radiating ribs but with very numerous
and fine radiating and concentric striz.

Portage (Naples fauna) of New York.

LI. LuNuLIcARDIUM Munster.

Usually triangular, with acute and abruptly terminal, posteriorly
turned beaks. Shell usually obliquely truncate in front, with a
deeply impressed area posterior to the beaks ; in this area, between
the two valves, is a conspicuous opening for the byssus. Posterior

428 NORTH AMERICAN INDEX: FOSSILS.

and basal margins regularly rounded. Surface crossed by con-

centric striz and usually by radii. Teeth absent. Pallial line
simple. Siluric and Devonic.
177. L. curtum Hall. . (Fig. 556, d, ¢.) Devonic.

Length usually less than height. Surface marked by 25-30
regular plications with wider interspaces and by fine lamellose
concentric strie.

Marcellus and Hamilton: New York.

178. L. ornatum Hall. Devonic.
Differs from ZL. curtum in its proportionately shorter and
straighter anterior margin and the more numerous plications
(45-60).
Hamilton—Chemung: New York.
179. L. acutirostrum Hall. (Fig. 556, 7.) Devonice.
Acuminate; lateral margins long. Surface marked with simple
radiating plications crossed by coarse concentric growth lines.
Genesee: New York.

LIT. Prerocyu ania Clarke.

Differs from Lunulicardium in its thin valves, surface marked
only with fine concentric growth lines; all radiating lines lie on
the inner surface of the valves and
may be outwardly visible by trans-
lucence. Beaks turned forward. An-
terior to the beaks and bounding the ©
conspicuous byssal opening is a wing-
like flange which is widest at the
beak becoming rapidly narrower to-
wards the base of the shell. Devonic.

180. P. fragilis (Hall). (Launulicar-
dium fragile.) (Fig. 556, f+.)

Devonic.

Fic. 559. Pterochenia sinuosa, : ‘ 1: : .
Riper ealeasc 3%, (deter Clase, Small, not exceeding 3 inch in di
N. Y. Surv. Mem., 6.) ameter, elongate-oval, fragile. Sur-

! : face marked with concentric strie.
Usually the flat expansion bordering the posterior edge is broken
off.
Marcellus—Portage : New York—Indiana.

PELECYPODA—PRIONODESMACEA. 429

181. P. sinuosa Clarke. (Fig. 559.) Devonic.
Differs from P. fragilis in its larger size, sinuous surface and
undulated outline.
Genesee: New York.

LIII. Honetovea Clarke.

Differs from Lunulicardium in the minute, inflected beak, and
the abrupt slope from the sides of the umbo to the hinge line.
Anterior to the beak is a_ byssal
notch and posterior to the beak is a
similar concave area which contains
no such opening between the valves.
Surface covered with radiating ribs.
Devonic.

182. H. erinacea Clarke. (Fig.
560. ) Devonic.

Subtriangular. Surface marked
with 12-15 sharply angular ribs al-
ternating with 3 or 4 weak rays.
The ridge bounding the posterior

hinge area gives off four to six hol- — F!6- 560. Honeoyea erinacea,
left valve, 5; cardinal view of
another left valve, 3. (After
Portage : New York. Clarke, N. Y. Surv. Mem., 6.)

low spines.

LIV. Amsonycuia Hall (emend Ulrich).

Equivalve and very inequilateral. Beaks nearly or quite ter-
minal. No anterior wing present but a more or less winged pos-
terior extremity. Valves ventricose, thin, and tightly closed all
around. Surface marked with fine radiating striz crossed by con-
centric growth lines and obscure undulations. .Two small, oblique
cardinal teeth present ; lateral teeth absent. Ligament external.
Posterior adductor scar large and bilobed; no anterior adductor
present. Pallial line simple.

Differs from Clonychia in the more convex valves, the more
strongly incurved beaks, the radial striations, and in the posses-
sion of a small, lobe-like cavity beneath the beaks where in
Chonychia there is a mere thickening of the margins of the
valves.

430 NORPE AMERICAN, EN DEX FOS SES.

Differs from Ayssonychia in the absence of the anterior byssal
opening and lateral teeth.

The Ambonychiide differ from the Aviculide in being equi-
valved and without anterior wing. Ordovicic.

183. A. bellistriata Hall. (Fig. 561, a, 0.) Ordovicic.
Beaks very prominent and strongly incurved. Surface marked
only by radiating striz.
Middle Trenton: New York. Middle Galena of Minnesota
and Cincinnati Group of Indiana.

Fic. 561. a, 6, Ambonychia bellistriata, \eft valve and anterior view; c, d, A. amyg-
dalina. (Minn. Surv.)

184. A. amygdalina Hall. (Fig. 561, ¢, d.) Ordovicic.
Differs from A. dellstriaza in its larger size, less incurved beaks,
and less angular post-cardinal margin.
Trenton: New York, Canada. Middle Galena of Minnesota.

LV. ANOMALODONTA Miller.

Closely similar to Améonychia in outline and general appearance
but differing in possessing a byssal opening. Distinguished from
both Ambonychia and Byssonychia in the absence of both cardinal
and lateral teeth. Ordovicic.

.

eee

PELECYPODA—PRIONODESMACEA. 431

185. A. alata (Meek). (Ambonychia alata.) Ordovicic.
Outline triangular with hinge line nearly at right angles to the
anterior margin. 24-28 strong, radiating ribs present.
Upper part of the Cincinnati Group of Ohio, Indiana.

LVI. ByssonycuiA Ulrich.

Resembles Ambonychia but differs in its more erect form and in
the presence of a byssal opening in the upper half of the anterior

ks

Fic, 562. a, 6, Byssonychia intermedia; Fic. 563. Byssonychia? byrnest. (Pal.
c, B. radiata (p=pallial line), (Minn. Ohio, VII.)
Surv. )

side and in the presence of two or three slender lateral teeth situ-
ated posteriorly, as well as several cardinal teeth. Radiating lines
usually stronger than in Ambonychia. Ordovicic.

186. B. intermedia (Meek and Worthen).
Brig. 502, 2, 0.) Ordovicic.
Small. Beaks strongly incurved, with a

slight forward direction.

Galena: Illinois, Wisconsin, Minnesota,

Lake Winnipeg,,Canada. ‘Fig. 564. _ Byssony-

2 J . chia acutirostris. (After

187. B.? byrnesi Ulrich. (Fig 563.) Ulrich, Pal. Ohio, VII.)
Ordovicic.

The hinge is peculiar, having no lateral teeth and only one
cardinal. It differs externally from B. acutirostris (Fig. 564) in
the byssal opening not being impressed ; hinge line slightly longer ;
radii 20 to 22 and slightly curved, instead of 36 to 4o and straight
as in BL. acutirosiris.

Utica: Kentucky, Tennessee.

432 NORTH AMERICAN INDEX FOSSILS.

188. B. precursa Ulrich. (Fig. 565.) Ordovicic.
Radii 38-42. Like 4. radiata but differs in its less obliquity,

longer hinge line, and especially in the flattening of its anterior
side.

Lorraine of New York, Ohio, Kentucky.

189. B. radiata (Hall). (Figs. 562, c, 566.) Ordovicic.
Surface marked by strong radiating ribs which are often grooved

on the upper portion of the shell, giving them a duplicate char-
acter.

Cincinnati Group: New York—Iowa and Wisconsin.

Fic. 565. Syssonvehia precursa. (Pal. Fic. 566. Byssonychia radiata. (Pal.
Ohio, VII.) Ohio, IT. )

LVII. Attonycuia Ulrich.

Like Lyssonychia in the possession of a byssal opening but with
neither cardinal nor lateral teeth. Likewise more erect than other
Ambonychia-like forms. Ordovicic.

190. A. jamesi (Meek). Ordovicic.
Not winged posteriorly but with a lobe-like projection anteriorly.

Surface marked with regular radiating ribs. Type of genus.
Cincinnati Group of Ohio.

a

LVtil.. Miyrinargca Hall,

Differs from /lethomytilus in the presence of cardinal teeth.
Devonic—Miss.

191. M. chemungensis Conrad. (Fig. 567, a, 0.)

Devonic.
Shell convex, of medium size. Beaks elevated.

Chemung of New York.

PELECYPODA—PRIONODESMACEA. 433

192. M. fibristriata White and Whitfield. (Fig. 567, c.)
| Upper Devonic and Mississippic.
Differs from MZ. chemungensis in its straighter form, more erect
beaks, and thread-like undulating radii.
Chemung: Iowa. Mississippic: Michigan, Ohio, Iowa.

Fic. 567. a, 4, Mytilarca chemungensis, right valve showing striated ligament area
and left valve showing small cardinal teeth; c, AZ. fibristriata, leftvalve; d, e, Pletho-
mytilus oviformis. (Pal. N. Y., V.)

LIX. PLetuHomytitus Hall.

Equivalve, very inequilateral. Hinge line straight. An obscure
posterior ear present. Surface covered with concentric striz.
Ligament external, its area striated. Lateral teeth oblique; no
cardinal teeth present. Pallial line simple. Devonic.

434 NORTH AMERICAN INDEX FOSSILS.

193. P. ponderosus Hall. (Fig. 568.) Devonic.
Shell gibbous, large.
Onondaga: New York, Ohio, Ontario.

Plethomytilus ponderosus KM%. (Pal. N. Y. V.)

194. P. oviformis Conrad. (Fig. 567, d, ¢.) Devonic.

Differs from P. ponderosa in its proportionately longer hinge
line, smaller size, and less gibbosity.

Hamilton: New York, Pennsylvania. Lower Devonic of
Nevada.

LX. Cxrionycuia Ulrich.

Resembles Ambonychia but differs in its smaller and but little

incurved beaks, in the possession of concentric striz alone, and in

Fic. 569. a, Clionychia lamellosa, \eft valve; 6, C. undata, left valve. (After
Ulrich, Minn. Surv. )

the thickening of the hinge margins anteriorly, producing in inter-
nal molds a well-marked impression in this part.

MOLLUSCA—PELECYPODA. 435

Differs from Mytilarca in its less oblique form and in the absence
of teeth. Ordovicic.

195. C. lamellosa Hall. (Fig. 569, a.) Ordovicic.
Anterior margin almost straight and sloping sharply back-
ward. Beaks attenuate. Concentric growth lines lamellose.
Stones River Group : Illinois, Wisconsin ; also Minnesota, Okla-
_ homa.

196. C. undata Emmons. (Fig. 569, 4.) Ordovicic.
Form subquadrate. Surface crossed by broad undulations.
Trenton: New York, Middle Galena of Minnesota.

LXI. AvicuLopinna Meek.

This differs from /2xzna in that its beaks are farther removed
from the extreme point of the shell though still nearly terminal ;
this leaves a small anterior ear,
best seen in internal molds. A
linear thickening is present along
the cardinal border. Surface
marked by strong, regular, equally

: é Fic. 0. Aviculopinna americana.
distant, concentric lamellz. Car- ae icaneds oa VI.)
bonic and Permic.

197. A. americana Meek. (Fig. 570.) Carbonic.

Beaks nearly obsolete, very oblique, and but slightly behind the
obtusely pointed anterior extremity. Surface marked with two or
three broad, faint, radiating ridges on the posterior dorsal region.

Coal Measures: Ohio, Iowa, Missouri, Nebraska, Kansas.

198. A.? peracuta Shumard. (Fig. 571.) Carbonic—Permic.
Shell almost cylindrical. Cardinal edges of valves suddenly
erected so as to give the hinged margin a keeled appearance.
Surface covered with very obscure growth lines. Differs from the
typical Aviculopinnas in its non-lamellose surface.
Throughout the Carbonic from Pennsylvania to Colorado and
Arizona. Also in the Permic of Kansas.

LXII. Pinna Linnzus.
Shell equivalve, thin, with a long hinge line. Beaks very
nearly or quite terminal. Valves keeled, triangular, wholly open
and truncate behind, without teeth. Muscle scars two. Shell

436 NORTH AMERICAN INDEX FOSSILS.

structure coarsely prismatic, with a thin, partial, nacreous lining;
byssiferous. Jurassic—Recent.

199. P. petrina White. (Fig. 572.) Cretacic.
Cardinal margin concave. Surface marked with strong growth
lines.
Benton : Colorado, New Mexico?

Fic. 571. Aviculofinna ? peracuta, X14. Fic. 572. Pinna petrina, left valve, < 4
(Kansas Pal., VI.) (After Stanton, Bull. 106, U. S. G. S.)
200. P. laqueata Conrad. (Fig. 573.) Cretacic.

Nine to eleven strong, simple radiating ribs on the dorsal
portion of valves; lower portion with very strong concentric
striz parallel to the margin.

Ripleyan of New Jersey (Merchantville—-Navesink), Gulf region.

LXIII. Conocarpium Bronn.

Very inequilateral. Anterior side short, truncated and flat-
tened laterally but produced along the hinge line into a beak-like
appendage ; this appendage, however, is usually broken away,
leaving a round hole in the flat anterior view. Posterior side

PELECYPODA—PRIONODESMACEA. 437

extended and gaping in lateral view. Beaks prominent and strongly
incurved. Hinge line long. Umbonal ridge prominent, outlining
the flat anterior side. Surface marked by concentric striz and

Fic. 573. inna laqueata, X 2. (Pal. N. J., I.)

3

usually by radiating plications which crenulate the basal margin.
Hinge bearing a single lateral tooth, with occasionally an obscure
cardinal tubercle. Ligament external. Pallial line simple.

There is often present an expansion of the shell extending ante-
riorly from the entire periphery of the umbonal ridge. Ordovicic—
Permic.

Fic. 574. Conocardium cuneus. GEaN.. Vay V)

201. C. cuneus (Conrad). (Fig. 574.) Devonic.
Valves gibbous. Umbonal slope angular. Radiating plica-
tions numerous, crossed by lamellose concentric striz.
Schoharie Grit and Onondaga of New York. Columbus of
Ohio, Falls of Ohio, Ontario. Also Hamilton of Illinois. A

438 NORTH AMERICAN INDEX FOSSILS.

closely related form, C. monroicum Grabau, occurs in the Upper
Siluric (Upper Monroe) of Michigan and Canada.

202. C. ohioense Meek. (Fig. 575.) Devonic.
Umbonal slope rounded. The produced posterior extremity is
sharply separated from the convex anterior.
Onondaga: Ohio, Falls of Ohio.

Fic. 575. Conocardium ohioense, right Fic. 576. Bakewellia gouldiz, internal
valve. (Pal No. Y., V2) mold. (Kan. Univ. Bull.)

LXIV. BaKkEWELLiA King.

Small, obliquely elongated, with posterior wing, subequivalve,
gaping in front for the passage of the byssus. Umbos depressed,
oblique. Surface covered with concentric strie. Hinge with
linear anterior and posterior teeth parallel to the cardinal margin.
Muscle scars as in Previa. Two to five cartilage furrows present
in each valve. Carbonic—Permic.

203. B. parva Meek and Hayden. Carbonic—Permic.
Very small, its axis forming an angle of about 30° with the
straight cardinal margin.
Carbonic: Kansas, New Mexico, Arizona. Permic: Kansas,
Nevada.

204. B. gouldii Beede. (Fig. 576.) Upper Permic.
Beaks low. Umbonal ridge well defined.
Common in Oklahoma (Whitehorse), Texas (Quartermaster).

LXV. GERVILLIA Defrance.

Very inequivalve. Beaks nearly or quite terminal. Posterior
wing obscure. Hinge plate thick, marked with a series of trans-
verse ligament pits and by obscure dental ridges subparallel to the
long axis of the valve.

Differs from Bakewellia in being larger and more elongate,
usually with more cartilage pits, and especially differing in that
its hinge teeth all range obliquely forward and upward instead of
those on the anterior and posterior sides being elongate parallel to
the hinge margin. Triassic—Eocenic.

PELECYPODA—PRIONODESMACEA. 439

205. G. propleura (Meek). (Fig. 577.) Cretacic.
More or less oblique. Right valve flat, smooth, without a
byssal notch.
Colorado (Benton), Utah (Coloradoan), Georgia (Ripleyan).

:

Fic. 577. Gervillia propleura, left valve. (After Stanton, Bull. 106, U. S. G. S.)

LXVI. GeErRvILLIOoPsis Whitfield.

Differs from Gervidiia in the absence of teeth on the posterior
portion of hinge and the oblique dental ridges below the ligament
area on the posterior end. It also differs in the truncation of the
anterior end, in the continuation of the ligamental (striated) area
along the anterior truncation, and in the gaping of the valves
anteriorly. Beaks terminal. Comanchic—Cretacic.

206. G. invaginata White. Comanchic.

Curved, marked by a central ridge running down its entire
length midway between the margins. Hinge line with about 12
ligament pits.

Upper Washita of Texas.

440 NORTH AMERICAN INDEX. FOSSES,

207. G. ensiformis (Conrad). (Fig. 578.) Cretacie,
Very oblique, elongate, narrow, and somewhat sickle-shaped.
New Jersey (Merchantville-Red Bank), and Gulf region.

Fic. 578. Gervilliopsts enstformis, interior of left valve and basal view of anterior -
end. «(After Whitfield, Pal. N.cj4 T.)

LXVII. INnocERAMus Sowerby.

Rounded, marked with more or less prominent concentric undu-
lations. Umbos prominent, somewhat anterior. Hinge line long,
straight, without teeth, but with numerous, small, transverse liga-
ment pits. Jurassic, Comanchic and especially Cretacic.

A: Malwés strongly vamedual’. 2 ciihshts nactactcany opeimaas wr tne sae ueaee ses 213. Ll. umbonatus.
5B; Walves subequal 5. 60 <- cic oss ethene aug vies a teow veties sud nove ea! Sune oes whee k,
lA median depression im Cache valve (ois 2s<cnsaced os Soe Wapcanane cena 212. 1. gilbertt.

EL. No median depressions ic... ocded bet vael s vgteee ieee le ut oea vers sdkoucah este nn e

1. Umbos thick, rather strongly elevated). 0.7.0. 5....0.., cicseonsoouce eee a.

a. Concentric undulations angular ......5...5... isc. 211. /. undabundus.

a, Concentric undulations rounded. .i..5..0:5.c.000ceuecrees 215. L. dcformis.

1. Umbos low’but often prominent... 0.625. ..6e6 Jaces ctee sn denussees eee b,

6, Height.of shell about 1 inch or less... die... kets acs 208. /, dimidius.

6. Height,of shell 2 inches or more:,:..55.i... s.dvenc.s. ss epee od cols

IT; BEG Very BOUle..2.cagsthewar ues reuse. lodees resedhae ieee aa,

ad. Height about: 1, § 1ichesy cc ic20Vivetntte ee 210. L, fragilis.

ao. Tieight ab@at © InChesy. 3 iov ast don ah enlane Peele 216. J. altus.

1X. Beak rather obtuse... 3 .2...5-..esessesesedess ae feeravecon geen b6.

66. Beak at anterior edge of shell ............... 220. L. barabini.

66. Beak not quite at anterior edge of shell.......... oseceeaeeemas ke

+. Average length of shell less than 3 inches.
218. 1. proximus.
+. Average length of shell more than 3 inches........ vente
*, Length and height about equal.
217. Ll. nebrascensis.
*. Length greater than height.. ;........../...cccceeem 17

PELECYPODA—PRIONODESMACEA. 441

1/’, Greatest length subparallel to hinge line.
209. J. simpsont.
1’’. Greatest length at about 45° to hinge line.
214. JL, labiatus.
66. Beak but little in advance of middle of shell.
219. Lf. vanuxemt.

208. I. dimidius White. (Fig. 579.) | Cretacic.
Shell small. Beaks pointed, small, £
but prominent. Valves subequal.

Coloradoan: Kansas, Colorado,
Utah, New Mexico.

209. I. simpsoni Meek. (Fig. 580.)
Cretacic. FIG. 579. Jnoceramus dimidius,
left and anterior views. (After Stan-

Large; length nearly twice the sie Bell: 166.1

height. Anterior end very short.
Beaks incurved, projecting but little above the hinge line.

Fic. 580. Jnoceramus simpsoni, right valve, K %. (U.S.G.S., Bull. 106.)

Coloradoan: Kansas, South Dakota ; also Cretacic of San Luis
Potosi.

210. I. fragilis Hall and Meek. (Fig. 581, a.) Cretacic.
Anterior side vertically truncate. Beaks almost equal, pointed,
scarcely rising above the hinge line, curving inward and slightly
forward at the points. Surface marked with fine growth.lines and
a few obscure concentric undulations,
Benton: Texas to Dakota and Montana.

442 NORTH’ AMERICAN INDEX “FOSSILS.

Fic, 581. a, Lnoceramus fragilis, right valve ; 4, c, Z. gelberti, left valve. All & %,
(U.S. G. S., Bull. 106, after Stanton.)

211. I. undabundus Meek and Hayden. (Fig. 582, c, a.)
Cretacic.

Fic. 582. a, Lnoceramus deformis, right valve ; 6, Z. umbonatus, cardinal view of «@
left internal mold; c, d, J. undabundus, left valve. All K %. (U.S.G.S., Bull.
106. )

PELECYPODA—PRIONODESMACEA. 443

Shell gibbous, obliquely subrhombic in outline. Beaks nearly
terminal. Concentric undulations strong, subangular.
Benton: Kansas, Montana.

212. I. gilberti White. (Fig. 581, J, c.) Cretacic.
Surface of each valve marked with a poorly defined median fur-
row and with extremely prominent concentric wrinkles.
Benton of Kansas and approximately the same horizon in Utah.

213. I. umbonatus Meek and Hayden. (Fig. 582, 6.) Cretacic.
Left valve very convex with strongly incurved beak; height
more than one third greater than the antero-posterior diameter.
Right valve subcircular, nearly flat; beak rather oblique; surface
marked with concentric undulations.
Benton: Kansas, Montana. Niobrara: Texas.

214. I. labiatus Schlotheim. (Fig. 583.) Cretacic.
Outline obliquely elongate. Surface marked with concentric
undulations. Average length about eee
4 inches; breadth at right angles ee ni we
to the greatest length 2 inches. Goce
Coloradoan throughout the
Plains and Rocky Mountain region.

215. I. deformis Meek. (Fig. +3
582, a.) Cretacic.
Beak moderately prominent, sit- » Bee? Sty

uated between the middle and the ?\ ae

anterior extremity of the hinge.

Surface with strong regular or very

irregular concentric undulations be- ¢

coming abruptly smaller on the Fic. 583. Inoceramus labiatus,
umbo where their curves indicate a A Seabee ie Sue et Ba
greater obliquity of the young §=

Shell. Shell thick, prismatic structure coarse.

Very abundant inthe Niobrara of the Rocky mountains and

Plains.

216. I. altus Meek. Cretacic.

Differs from /. fragizs in its larger size (about 6 inches high,
hinge length 2 inches), more concentric undulations, though ob-
scure, and faint traces of radiating markings.

444 NORTH AMERICAN INDEX FOSSILS.

Montanan of Kansas, Wyoming, Alberta; also Coloradoan of
South Dakota.

217. I. nebrascensis Owen. Cretacic.
Beak about one fifth the length of the shell from the anterior
border. Average length and height 5 inches. Anterior side
short, making a very broad, oblique curve from beak to base.
Posterior and basal margins broadly rounded. Hinge rather short.
Differs from /. proximus in its larger size and coarser concentric
undulations. |
Montanan of the Plains and Rocky Mountain regions.
218. I, proximus Tuomey. (Fig. 584.) Cretacic.
Hinge line about two thirds the length of the shell. Basal and
posterior margins broadly rounded. Average length and height
about two inches. Differs from /. daradini in being more com-

Fic. 584. Jnoceramus proximus. (After Whitfield, Pal. N. J., I.)

pressed, less oblique, and in having more regular and closely
arranged concentric undulations.

Pierre: South Dakota, Colorado. Ripleyan of New Jersey
and the Gulf region.

219. I. vanuxemi Meek and Hayden. Cretacic.

Subcircular. Hinge short. Beaks located a little in advance
of the middle. Valves slightly convex. Surface marked with
regular, coarse concentric undulations. Average length 5 inches;
height 4.5 inches. Distinguished from /. zebrascensis by its much
less convex and nearly circular form, its less prominent and more

|

PELECYPODA—PRIONODESMACEA. 445

flattened beaks which are also not so oblique and are more distant
from the anterior end.
Pierre: Rocky Mountain region.

220. I. barabini Morton. Cretacic.
Moderately gibbous anteriorly, cuneate posteriorly.
Abundant in Pierre of Rocky Mountain region; also in Fox
Hills formation.

LXVIII. Preria Scopoli. (Avicula Bruguiere.)

Obliquely oval, inequilateral, inequivalve. Left valve more
convex than right. Hinge line long, straight, with one or two
small cardinal teeth and a lamellar lateral. Posterior ear wing-
like, longer than anterior. A byssal sinus present under right
anterior ear. Ligament in a groove, partly internal and partly

external. Posterior adductor scar large, subcentral; anterior

scar absent in adults. Ordovicic—Recent.

This rather inclusive genus is divided into very many subgenera
among which are Actnopteria, Pteronites, Ptychopteria and Monop-
teria. Many species are left here for want of better material to
determine their subgeneric relations.

221. P. sulcata (Geinitz). (Fig. 585.) Carbonic.

Fic. 585. teria sulcata. (Kansas Fic. 586. teria longa. (Kansas
Pal., VI/II. ) Pal., VI/II.)

Marked anteriorly with two or three radiating furrows and with
several concentric folds.
Kansas, Nebraska.

222. P. longa (Geinitz). (Fig. 586.) Carbonic and Permic.

Body of shell obliquely elongated and more or less arcuate.
Coal Measures of Interior. Permic: Oklahoma, Texas.

223. P. petrosa (Conrad). (P. “inguiformis E. and S.)

Cretacic.
Surface marked only by concentric growth lines.

Ripleyan of New Jersey (Cliffwood—Wenonah). Montanan of
the Plains and of the Rocky Mountain region.

446 NORTH AMERICAN INDEX FOSSILS.

224. P. gastrodes Meek. (Fig. 587.) Cretacic.
Shell thick. Surface marked with fine and closely arranged
growth lines.
Benton: Kansas, Colorado. Coloradoan of Utah.

Fic. 587. teria gastrodes, left valve, « 24. Fic. 588. Pteria limula, \eft
(After Stanton. ) valve, (Md. Surv. )

225. P. nebrascana Evans and Shumard. Cretacic.

Differs from P. gastrodes in having smaller wings, a much
shorter hinge line, and a much more oblique axis. Anterior ear
very small. Surface under a lens shows traces of small radiating
ribs. Average length from end of anterior ear to posterior basal
margin .45 inch; length of hinge .32 inch; convexity of the two
valves .15 inch.

Montanan : Plains and Rocky Mountain region.

226. P. limula (Conrad). (Fig. 588.) Eocenic.
Beak acute. Sinus of posterior ear not deep.
Pamunky: Maryland, Virginia.

Fic. 589. Pteronites profundus. (Pal. N. Y., V.)

LXIX. Preronites McCoy.

Differs from Actinopteria in having hinge and rest of the shell
much extended posteriorly. Hinge line longer than body of shell; ~

PELECYPODA—PRIONODESMACEA. 447

surface marked by concentric strize. Upper Devonic to Missis-

sippic.

227. P. profundus Hall. (Fig. 589.) Devonic.
Umbonal region gibbous. Anterior ear acute. Posterior ear

not defined. Surface covered with concentric striz which rise at

intervals into undulations.
Chemung: New York.

LXX. ActTINopTERIA Hall. (Avicwla Bruguiere of American
authors in part.)

Inequivalve, oblique, thin. Anterior muscle scar faint or ab-
sent. Pallial line simple. Differs from Prerinea in the absence
of a broad striated ligament area and strong cardinal and lateral
teeth. Devonic.

228. A. communis Hall. Devonic.
Differs externally from Pterinea flabellum in its smaller anterior
ear, weaker rays of both sizes which are practically absent from
both ears, finer concentric striz, and in the greater similarity of
the surface marking on the two valves.
Helderbergian: Maine, New York (New Scotland), New Jer-
sey, Tennessee.

229. A. textilis Hall. (Fig. 590.) Devonic.

Externally very similar to Prerinea flabellum ,; distinguished by
the greater strength of its intermediate rays and by its longer
posterior wing and greater obliquity.

Fic. 590. Actinopteria textilis. (Pal. N. Y., III.)

Helderbergian: New York. Oriskany: New York, New Jer-
sey, Tennessee ?, New Brunswick.

448 NORTH AMERICAN INDEX FOSSILS.

230. A. textilis var. arenaria Hall. Devonic.
Distinguished from A. ¢extzlis by its greater size and its shorter
posterior wing which extends only about one half the distance
from beak to base.
Very common in the Oriskany of New York, New Jersey,
Pennsylvania, Maryland, Ontario, Quebec.
231. A. muricata Hall. (Fig. 591, 2.) Devonic.

Fic. 591. a, Actinopteria muricata, X 2; 6, A. subdecussata ; c, A. decussata, \eft
valves ; ad, Ptychopteria sinuosa, left valve, showing oblique cardinal and lateral teeth ;
¢, f, P. sao, left and cardinal views. (Pal. N. Y., V.)

Small. Beak acute and arching over the hinge. Anterior ear
separated from the body of the shell by a broad undefined furrow
which is bounded anteriorly by a strong fold. Surface marked
with 8-12 strong rays alternating with finer ones which are con-
tinued over the posterior ear. Rays crossed by concentric strie.

Marcellus: New York, Pennsylvania.

P
:

PELECYPODA—PRIONODESMACEA. 449

232. A. subdecussata Hall. (Fig. 591, 2.) Devonic.
Beak nearly terminal. Ear very small, limited by a vertical
furrow. Surface marked with alternating strong and weak, sub-
angular rays crossed by concentric striz.
Hamilton: New York, etc.

233. A. decussata Hall. (Fig. 591, c.) Devonic.
Differs from A. subdecussata in the greater and nearly equal
convexity of the two valves, in the broader furrow at the anterior

a Pines

FIG. 592, Actinopteria boydi. (Pal. N. Y., V.)

ear, and in the stronger rounded rays and their interruption by
the concentric lamellz.
Hamilton: New York, Pennsylvania.

234. A. boydi Conrad. (Fig. 592.) Devonic.

Differs from A. subdecussata in the less defined furrow at the
anterior ear, the less obliquity and broader body of the shell, and
in the rays being practically of one size.

Abundant in the Hamilton: New York, Pennsylvania, Indiana,
Ontario. Portage: New York (characteristic). Lower Devonic
of Nevada.

LXXI. PrycHopreria Hail.

Differs from Actinopteria in the pointed anterior extremity and
large, straight wing marked by a strong longitudinal fold. Hinge
line linear, with one or two linear oblique cardinal and lateral
teeth. Surface marked with fine rays. Devonic.

450 NORTH AMERICAN INDEX FOSSILS:

235. P. sinuosa Hall. (Fig. 591, d.) Devonic.
Extremities of hinge angular. Anterior portion of shell with
broad sinus. Surface marked by fine undulating rays, crossed by
concentric striz which are at times crowded into lamelle.
Chemung: Pennsylvania.
2360-P.s8a0 Flak 4 Pie O01, 08, 4.) Devonic.
Differs from P. s¢zuosa in the less distance between the anterior
end of the shell and the sinus, and in the longer and more truncate
posterior wing.
Chemung Group: New York.

LX XII. Monoprerta Meek and Worthen.
Differs from Pverinea in the absence of teeth, in the very obscure
or obsolete anterior muscle impression; anterior ear represented

Fic. 593. Monopteria longispina. (Kan. Pal., VI/II.) :
Fic. 594. «a, Monopteria gibbosa, right valve; 6, Pseudomonotis curta, left valve,
(Ind. Surv. and Kan. Univ. Quarterly. )

by a very small appendage drawn back between the beaks in a

deep lunule, not seen in side view. Posterior wing slender, pro-

duced. Body of shell obliquely produced and angular posteriorly.

Devonic to Carbonic.

237. Ms longispina (Cox). (Fig. 593.) Carbonic.
Surface covered with fine concentric growth lines.
Kentucky—Colorado.

238. M. gibbosa Meek and Worthen. (Fig. 594, a.) Carbonic.
Semicircular in antero-basal marginal outline, posterior end and

wing about equally produced.
Pennsylvania—Kansas.

LXXIII. PsEupomonotis Beyrich.
Suborbicular, inequivalve. Right valve convex, with prominent
incurved beak and small or obsolescent ears. Left valve flattened, ~

PELECYPODA—PRIONODESMACEA. 451

with slightly prominent beaks; anterior ear minute or wanting.
Devonic—Cretacic.

239. P. hawni Meek and Hayden. (Fig. 595.)
Carbonic and Permic.

Posterior ear narrow, obliquely trun-
Sate...” Anterion ear “larger: Surface
marked with irregular undulating ribs of
unequal size and concentric lamelle
which at times are very strong over the
cost.

Carbonic: Pennsylvania — Colorado.
Permic of Kansas.

240. P. kansasensis Beede. (Fig.
596.) Carbonic and Permtie. > 2 (S95, -eseecomonois
: : : hawni. (Kan. Pal., VI/II.)
Hinge line nearly straight. Both ears
rounded to meet the hinge. Radiating striz wavy.

i}
( \
Fic. 596. Psewdomonotis kansasensts. (Kan. Pal., VI/II.)

Coal Measures: Ohio—Colorado and Arizona. Permic of Kansas.
241. P. equistriata Beede. (Fig. 597.) | Carbonic and Permic.

Differs from P. hawni in being smaller and shorter, slightly
more convex, and in having regular striz.

Pennsylvanic: Kansas, Colorado. Permic: Kansas (Garrison).
242. P. subcircularis (Gabb). (Fig. 598.) Triassic.

Ribs alternating in size.

452 NORTH AMERICAN INDEX FOSSILS.

Triassic of Nevada; California—British Columbia

243. P. curta Hall. (Fig. 594, 3.) Jurassic.
Surface marked with fine radiating plications, crossed by con-

Fic. 597. Pseudomonotis equistriata, (Kan. Pal., VI/II.)

centric striz, producing small nodes at points of intersection.
Sundance: South Dakota, Wyoming.

LXXIV. Hatosia Bronn.

Equivalve, semicircular to semioval, with straight hinge, and
almost central, scarcely prominent beaks. Teeth absent. Surface
radiately ribbed. Wings absent or represented anteriorly merely
by a smooth, non-projecting area. Triassic.

—<—

Fic. 598. Pseudomonotis subctrcularts, left valve. (Pal. Cal.)

244. H. lommeli Wissmann. (Fig. 599.) Triassic.
Beaks very small, abruptly pointed, turned slightly forward.
Surface marked with more or less wide and irregular flat ribs,
separated by linear furrows, and by a few concentric growth lines
near the beak.
Nevada, British Columbia.

|
|
|

PELECYPODA—PRIONODESMACEA. 453

LXXV. Myatina De Koninck.

Inequilateral, inequivalve, obliquely ovate, slightly sinuous in
front for the passage of the byssus. Beaks pointed, terminal or
nearly so. Surface smooth or
marked with concentric striz.
Hinge without teeth. Ligament
area broad, and grooved parallel
with hinge line. Deep anterior
adductor scar under the beak.
Siluric—Permic.

245. M. sancti-ludovici Worth-
en. (Fig. 600.) Mississippic.
Subquadrate, oblique. Hinge

straight and equalling the great-

est width of the shell below.

Margin of shell regularly though

narrowly rounded at base, be-

coming broadly and shallowly
concave towards. the hinge line
anteriorly and posteriorly. Beak Fic. 599. Halobia lommeli; a slab
of left valve pointed, curving ob- with numerous individuals, (After Hall

, and Whitfield. )

liquely forward. Shell crossed

by strong and regular concentric lamine. Average length of

hinge line, # inch; length of shell at right angles to hinge, 1 inch.

Keokuk: Illinois, Kentucky, Missouri.

246. M. keokuk Worthen. Mississippic.
Distinguished from JZ. sancti-ludovici by its larger size (length
, ‘of hinge, 1.25 inches; length of shell at right

angles to hinge, 1.6 inches ; greatest length from
umbo forward, 2 inches), greater convexity of
body of shell and consequent greater promi-
nence of the posterior wing. Umbo stronger
and projecting above the hinge line. Anterior
side of shell more nearly truncate.

sancti-ludovict. (Pal. Keokuk: Illinois, Indiana, Iowa, Missouri,
i aeke Arizona (Escabrosa) ; also Colorado (Ouray).
247. M. angulata Meek and Worthen. Mississippic.

Differs from JZ. permiana in its larger size and concave hinge

454 NORTH AMERICAN INDEX FOSSILS.

line. Anterior margins of valves abruptly inflected from the um-

bonal ridge so as to meet on a plane at right angles to that of the

= valves. Beaks attenuate, compressed in front

FC 2 ) and behind. Posterior extremity of hinge
“Kh Dp angular. |

\\" iN Chester of Illinois. Kaskaskia of Missouri.

248. M. congeneris Walcott. (Fig. 601.)
Mississippic—Carbonic..
Differs from J7. perattenuata in having the
anterior and posterior margins parallel; also-
the anterior margin is straight while in JZ,
perattenuata it is concave.
Mississippic: Nevada. Upper Coal Meas-

ures of Kansas.

WAN

g (ff? /
Wn ANG,
NS

Fic, 601. Myalina 249. M. swallovi McChesney. (Fig. 602,.
congeneris. (Kan. Pal. a, b.)
VI/II.)

Carbonic..
Small, nearly equivalve. Cardinal area
very narrow. [Doctor Hind makes this a synonym of the Eng-.
lish shell Mazadites triangularis Sowerby. |
Indiana—Wyoming
250. M. recurvirostris Meek and Worthen. (Fig. 602, c.)
Carbonic..
Convex. Beaks pointed; that of left valve twisted. Anterior

Fic. 602. a, 6, Myalina swallovi, dorsal view and right valve; c, AZ, recurvirostris,
interior of left valve. (Ind. Survey. )

margin thickened beneath the beaks so as to present a kind of
false area. Indiana—Iowa.

PELECYPODA—PRIONODESMACEA. 466

251. M. subquadrata Shumard. (Fig. 603.) Carbonic—Permic.
Large. Left valve more convex than right which is nearly flat.
[Doctor Hind suggests that this is the
equivalent of the English Mazadites quaa-
vula (Sowerby). |
Carbonic: Colorado, Arizona? Also in
Permic (Matfield) of Kansas.

252. M. perattenuata Meek and Hayden.
(Fig. 604.) Carbonic and Permic.
Hinge line very oblique to body of

shell.

Carbonic: Illinois-Colorado. Permic:

Kansas, Oklahoma, Texas.

253. M. aviculoides Meek and Hayden. F!S- 603. Myatina sub-
ee Pein; quadrata, right valve, \.
( 1g. 005, a.) ie (Ind. Survey.)
Beaks slender, greatly prolonged, with a
slight upbending at the point. Umbonal ridge placed near an-
terior border and parallel with it, angular and very convex, giving
the shell an almost vertical anterior face.
Kansas, Oklahoma, Texas, Utah?

254. M. permiana Swallow. (Fig. 605, 4.) Permic.
Hinge line shorter than width of shell below. Differs from J/.

Fic. 604. Myalina perattenuata, (Kan. Pal., VI/II.)
Fic. 605. a, Myalina aviculoides, right valve; 6, MZ. permiana, left valve.
(After White. )

aviculoides in its less convex and narrower valves, more rounded
umbonal ridge, and in wanting the upturned beaks.
Kansas, Oklahoma, Texas, Utah ?

LXXVI. PrycHopgEsmaA Hall and Whitfield.

Anterior end short, posterior end broadly rounded. Hinge line
short. Surface concentrically striated. Hinge with two or more

456 NORTH AMERICAN ANDEX FOSSILS.

teeth and a deep ligament area whose sides are marked with paral-
lel grooves. Devonic.

255. P. knappianum Hall and Whitfield. (Fig. 606, a—c.)
; Devonic.

Valves convex below and gibbous above. Concentric striz
interrupted by occasional growth varices. Externally resembles
some forms of Modiomorpha but is distinguished by the deeply
grooved ligament area characteristic of the genus. Type of the
genus.

Hamilton group: New York, Ohio, Falls of Ohio.

LXXVII. Mopretxia Hall.

Equivalve, very inequilateral, with short anterior end and very
broad and curved posterior end. Hinge line arcuate. Surface
covered with fine concentric striae. Hinge area longitudinally
grooved. Pallial line simple. Very similar to recent species of
Modiola but lacking the pronounced epidermis. Devonic.

Cc

Fic. 606. a-c, Plychodesma knappianum, right valve, ligament area enlarged, and
cardinal view; ad, Modtella pygm@a, X 2.

256. M. pygmea (Conrad). (Fig. 606, a.) Devonic.
Basal margin indented anterior to middle owing to the depres-
sion just anterior to the beak and extends to the base. Type of

the genus.
Hamilton: New York, Pennsylvania.

LXXVIII. AuceLta Keyserling.

Obliquely ovate, with anterior beaks. Left valve larger and
arcuate, with a small ear set off from the body of the shell by a

»

PELECYPODA—PRIONODESMACEA. 457

deep groove which extends from the margin nearly to the beak.
Right valve flatter and smaller. Hinge without teeth but furnished
with an interlocking angle in the right valve which fits into a corre-
sponding notch in the left valve. Ligament external, in a long

Fic. 607. Aucella crassicollis. a,a large right valve; 4, hinge of a left valve; c, a,
var, gracilis, two views of a left valve. (After Stanton. )

and shallow groove beneath the overhanging beaks. Differs from
Inoceramus in the presence of the sinus beneath the beak and in
the simple ligament groove as compared with the row of ligament
pits in /voceramus. Upper Jurassic to Cretacic.

Fic. 608. Aucella piochit, a, b, an average sized left valve; c, d, two views of a
more slender specimen ; ¢, /, var. ovata, two views of an average specimen. (After
Stanton. )

458 NORD AMERICAN: INDEX. FOSSILS,

257. A. crassicollis Keyserling. (Fig. 607.) Comanchic.
Large, inflated. Concentric markings varying from irregular

constrictions to strong plications.

British Columbia, Alaska, eastern Greenland. Knoxville of

California and Oregon.

258. A. piochii Gabb. (Fig. 608, a, 0.) Comanchic.
Small, thin-shelled. Concentric undulations regular.
Knoxville : California, Oregon, Washington.

258a. A. piochii var. ovata Stanton. (Fig. 608, c, d.)

Comanchic.
Larger than A. piochi, more broadly triangular, and more
convex. |
Knoxville : California, Oregon, British Columbia.

LXXIX. Ostrea Linneus.

Shell distorted by adherence to other objects. Structure
lamellar. Inequivalve, fixed by the left or larger valve. Beaks
terminal. Left valve convex, often marked with radiating ribs.
Right valve flat or concave, often smooth. Sculpture usually dif-
ferent on the two valves. Teeth generally absent. Anterior
muscle impression absent; posterior nearly central. Ligament
cavity conspicuous, triangular or elongate. Pallial line indistinct.
Carbonic to Recent.

A; Surface conspicuously. plicate radially i..c.ccvasnse nes esac sssce sceeseneenseaee ern fe
TE. Qutline estlbeircalarys. 5 F.s.c00ecsceesecnrs 0b aadasaddevs spussh'vsqhengees scat I.
i. Piichons owerwhale Valve | Luis 5. 2 cccvacane as Sescgem de wedees 267. O. lugubris..

¥_, Blcations, Only WargQinal sic cacs0ss<atssvatnneseedenneestaghavgheohe 265. O. panda.

I. Ontline sickle-shaped,.¢..e:, curved laterally.....24.2..03..-00: oc deos0eesceeeeeaeae 2:
2. entire stiell placate cos. tos:.c4<.ndeednogwedseindes aseh'a.0 +0) Sart ney deeee een a.

BP MCRAIOMS Ae ova eccswnnicaddisns eebabdsunwa tals savkdwacinms 262. O. quadriplicata.

Ao Pieatons more Cian i’ .. |... <sncdswnddaces Watess scum naeaeemnt 271. O. falcata.

2. Median area Notsplicate. «0.0 cs<eies ddvigsediag towsianes vaitchiees staan nn b.

#: Shell of medium) S126 was cscs nn new sages ween ved barks pewear 273. O. nasuta.

b. well ‘Sima... eas ass age seeiess was och isle wane wt vest sn adjeres chp asl een enn II.

rr. Shell euricwlate. (02. iii v.scses ws keto enpreees 272. O. mesenterica.

EY. Shell not euriculate.,.. oc v2.6 sce sss aca shew fea oeee 279. O. pellucida,

a; -Ourtlinia * frranentlars. veces sap dae eh ences vas anced tateweseite sant 260. O. crenulimargo.

I. Outline oblong-ovate with height much exceeding transverse diameter.
261. O. subovata.
&. Surface not conspicuously plicate radially except in some forms when young.....11.
ii: Both ‘valves deeply SintOwsy.....:dessvs -xwisdenyeunesdearteroucinns 281, O. selleformis.
LT. + Valves: not Simuousi, soi sidi daha dod aes Fae lead dan th aes see yews <)deeeesh peer L?
3. Lower valve very convex; upper valve flat or only slightly convex........ is

PELECYPODA—PRIONODESMACEA. 469

c. Lower valve attached by whole lower surface and deep.............. 22;
22. Sides bent up from area of attachment almost at a right angle.
266. O. congesta.

224 Sides. curved. upwaxdsitic.3.4-cs ee Seren 259. O. strigtlecula.

c. Lower valve not attached by whole lower surface..................0000: 33-
33. Shell winged: :posteriotly 4 fve,d2. sels sons tas seeas 275. O. bryant,

33. Shell not winged posteriorly........ Tasetbegu zakopane Pave slece Fei ore aa.

aa. Lower valve broadest below middle....................c eee eee T-

t. Lower valve very convex in central portion.
270. O. subspatulata.
t. Lower valve very convex towards umbo.
280. O. vomer.

da. Cower. valve ‘broadest: af middle. so jicccis-esnncn cca vavedence TT.

Apes Mae Ee oceise wosutees foams santas 282. O. compresstrostra.

A Pec Gots a, vents andes. careers 268. O. cretacea.

Si Leh wely es ORLY SIIPUULY. CONVER,..:-. 00.) os vagsretx cbs Hamann sr cedewsh Oa anes d.
A MIS SDI UCM AE oie! cis sannsawadeddoats tree sasduapssskecnmansaectee's 44.
As. Large, 3-4 inches high |.2.5..).0.2. asvvastevecrens 283. O. trigonalis.

44.) Small, not-2-inehes: high... , zagitcssdesteny' sua-se 274. O. plumosa.

Fe SMELLS CHIMES OVA. nie sata cares suse eWaeetdas min tecrta ts Rtvh snus ice wash a 55-
55. Shell attached by whole under side............ 278. O. inornata.

55. Shell not attached by whole under Sideé...............0c.ececeeees 66.

66, Shell. sligitthy arcuate laterally! oo. 5c ois. jcsesecencscacewese ite

ttt. Large (3 inches & 1% inches)....... 276. O. glabra.

ttt. Small (2 inches * I inch) .....277. O. subtrigonalis.

$6, ‘Stell not, arcuate lateralby. cig ses2ts dececssnvecedavsadaces ve 4f.

4¢+ Margins crenulate....3.ci.<0...005- 269. O. denticulifera.

4t. Margins not crenulate.................. 264. O. haydeni.

ae MEME HOBO-GV AN, 25 55 Sink cnkse 8ob seve cow on taleseircs 284. O. percrassa.

@. Outline very long and narrow with nearly parallel sides.
263. O. soleniscus.

259. O. strigilecula White. (Fig. 609.) Jurassic.

Fic. 609. Ostrea strigilecula. (Kan. Univ. Quarterly. )

Small (up to 1 inch in diameter). Lower valve attached by
entire surface.
Throughout the Jurassic of the Interior.
260. O. crenulimargo Roemer. (Fig. 610.) Comanchic.
Thin, subtriangular. Beaks short and blunt. Lower valve

460 NORTH: AMERICAN ANDEX. FOSSILS:

marked by 5 to 8 strong ribs, 3 of them much the strongest and
frequently outlining the shell as a more or less equilateral triangle.
Upper valve flat; ribs nearly obsolete. Anterior and posterior
margins of both valves minutely crenulated.
Texas (Trinity), northern Mexico (Washita).
261. O. subovata Shumard. Comanchic.
Large and massive, oblong-ovate. Both valves only slightly con-
vex. Beak of lower (left) valve elevated and projecting beyond that
of right. Surface coarsely imbricate and radially plicate, the ribs

a

Fic, 610. Ostrea crenulimargo. a, external, and 4, internal view of the
free valve. (After Roemer. )

usually about 6 or 8, sometimes with tubercles or spines at top.
Average height 6 inches. |

Common in Fredericksburg and Washita of Oklahoma, Kan-
sas, Texas and New Mexico.

262. QO. quadriplicata Shumard. (Fig. 611.) Comanchic.

Fic. 611. Ostrea quadriplicata. (After Hill. )

Main radiating plications 4, produced at edge of valve.
Washita of Texas (Denison), Oklahoma and Kansas.

263. O. soleniscus Meek. (Fig. 612.) Cretacic.»
Long and narrow. Often very large and thick.

q

PELECYPODA—PRIONODESMACEA. 461

Through the whole thickness of the Cretacic of Utah, Wyoming
and Colorado, and in the Dakota of Texas.

Fic. 612. Ostrea soleniscus, X %. (After White.)

264. 0. haydeni White. (Fig. 613.) Cretacic.
Small, usually not exceeding 2 inches in height.
Bear River: Wyoming, Idaho.
265. O. panda Morton. Cretacic.
Free margins of valves impressed with broad plications which
do not extend to the beak.
New Jersey (Marshalltown), Delaware, Texas (Coloradoan).

Fic. 613. Ostrea haydeni. (After White.)

266. O. congesta Conrad. (Fig. 614, c, d.) Cretacic.
Lower valve cup-shaped, with large area of attachment around
which the shell margin abruptly bends up at a right angle. Upper
valve flat, with form of attached portion of lower valve.
Very abundant in and characteristic of the Niobrara of North
America. Also occurs in the Benton.

267.0. lugubris Conrad. (Fig. 614, a, 0.) Cretacic.
Varying from small to medium in size (breadth from 3 inch to
2} inches). Plications 12 to 18 on each valve but developed only
around the margin of the upper valve.
Kansas, Colorado (Niobrara—Pierre), New Mexico (Niobrara),
Texas (Eagle Ford—Navarro).

462 NORDEA “AMERICAN INDEX FOSSILS.

268. O. cretacea Morton. Cretacic.

Irregularly ovate, non-plicate. Lower valve moderately con-
vex ; upper valve nearly flat. Surface marked with concentric
undulations. Height about 4 inch; width slightly greater.

pee l

Hie

GA i EU f}
aN
ps Ye , A YY

Fic. 614. a, 4, Ostrea lugubris, lower and upper valves ; c, d, O. congesta, interior of

upper valve slightly enlarged and a group of attached lower valves. (After Stanton. )

Ripleyan of New Jersey (Cliffwood), Georgia, Alabama,
Arkansas.

269. 0. denticulifera Conrad. (Fig. 615.) Cretacic.

Flattened, thick. Surface obscurely striate. Margin with tooth-
like crenulations.

Ripleyan of New Jersey (Woodbury), Mississippi, ‘Tennessee.

Fic. 615. Ostrea denticultfera, Conr. (N. J. Pal., I.)

270. O. subspatulata Forbes. Cretacic.

Outline somewhat wedge-shaped with rounded margins. Shell
widest below the middle whence it narrows gradually upwards.
Lower valve strongly arcuate longitudinally. Surface marked

|
|
.
.
j
|
;
|
;

ae a a

PELECYPODA--PRIONODESMACEA. 463

with strong concentric undulations. Internal mold nearly smooth.
Height about 2 inches; greatest width about 14 inches.
Ripleyan of New Jersey (Wenonah), Georgia, Texas.
271. O. falcata Morton (0. /arva of Americanauthors). (Fig. 616.)
Cretacic.
Lower valve moderately convex with small scar of attachment.
Upper valve flat. Plications alike on both valves.

Fic. 616. Ostrea falcata Morton. (After Whitfield, Pal. N. J., I.)

New Jersey (very abundant in Marshalltown ; also in Navesink),
Arkansas.
272. QO. mesenterica Morton. Cretacic.
Smaller than O. fa/cata and with non-plicate central area. New
Jersey (very abundant in Navesink ; also in Red Bank and Tinton).

273. O. nasuta Morton. : Cretacic.

Fic. 617. Ostrea plumosa Morton. (N., J. Pal., I.)

Central portion non-plicate as in O. mesenterica, from which it
differs in large size and broader plications.

New Jersey (Red Bank and Tinton; sparingly in Navesink),
Texas.

274. 0. plumosa Morton. (Fig. 617.) Cretacic.

464 NORTH AMERICAN INDEX FOSSILS.

Thin. Sometimes faintly plicate. Upper valve marked with
fine radiating strize which diverge from a median line.

New Jersey (Marshalltown—Red Bank), Virginia, Gulf region,
Wyoming (Montana).

275. O. bryani Gabb. Cretacic.
Somewhat like Gryphe@a convexa but with evidence of attach-
ment of convex valve and with beak not strongly incurved.
New Jersey (Vincentown and Manasquan).

276. O. glabra Meek and. Hayden. (Fig. 618.) Cretacic.

Fic. 618. Ostrea glabra. Upper and lateral view of a nearly complete shell,
x %. (After White. )

Subovate, sometimes slightly arcuate laterally. Beak of lower
valve curved to the right; cardinal area small and deep. Surface
of both valves entirely free from radiating plications or projecting
concentric lamellz, though there are obscure strize and a few faint
growth ridges. Size 3 inches x 14 inches.

Laramie : Colorado, Montana, Alberta. Fox Hills: Wyoming.
Pierre: Montana, Assiniboia. Also San Luis Potosi.

277. Q. subtrigonalis Evans and Shumard. Cretacic:

Small, depressed, narrowly ovate, slightly arcuate laterally.
Lateral margins of lower valve crenate. Upper valve nearly flat.
Surface of each valve marked with concentric striz2 and furrows.
Height not quite 2 inches; width not quite 1 inch.

Pierre: Montana, Alberta, Assiniboia. Livingston: Montana.
278. O. inornata Meek and Hayden. Cretacic.

Small, subovate, thin, attached by whole under side of lower
valve. Beaks pointed and bent laterally.

PELECYPODA—PRIONODESMACEA. 465

Pierre: South Dakota, Colorado; also in Montana of Wyom-
ing, Alberta, etc.
279. O. pellucida Meek and Hayden. Cretacic.
Similar to O. mesentcrica in size, thinness, falcate outline, and
marginal plications, but differs in its larger scar of attachment
which extends from the umbo to near the middle of the valve;
also lacks the straight hinge line with ears characteristic of O.
mesenterica.
Montana: Wyoming, South Dakota (Fox Hills), North Dakota
(Pierre), Montana (Pierre).
280. 0. (Grypheostrea) vomer (Morton). (Fig. 6109). :
Cretacic—Eocenic.
Lower valve deep. Upper valve marked with concentric plates.

Fic, 619. Ostrea (Grypheostrea) vomer. a, wpper valve; 4, c, lower valve.
(Md. Surv.)

New Jersey (Marshalltown—Vincentown), Delaware, Texas.
Eocenic: Maryland. 7
281. O. selleformis Conrad. (Fig. 620, a.) Eocenic.
Both valves deeply sinuous through vertical folding.
Eocenic: Maryland (Nanjemoy)—Alabama (Lignitic).
282. 0. compressirostra Say. (Fig. 620, 4.) Tertiary.
When young much like O. sel/eformis in form and plicate sur-
face. Differs when adult in lacking the sinuosity of O. selleforms.
Eocenic: Matyland—Alabama. Oligocenic: Florida. Mio-
cenic: New Jersey—Florida.
283. O. trigonalis Conrad. (Fig. 621, a, 4.) Eocenic—Pliocenic.
Lower valve few-ribbed. Upper valve flat.

466 NORTH AMERICAN INDEX (FOSSILS.

Upper Eocenic (Jacksonian): Mississippi, Alabama, Louisiana.
Lower Oligocenic (Vicksburgian): Florida and Mississippi. Mio-

Fic. 620. a, Ostrea selleformis, lower valve, X 24; 6, O. compresstrostra, lateral
view. (Md. Surv.)

cenic: Maryland (Choptank) and North Carolina. Pliocenic:
Florida.

284. OQ. percrassa Conrad. (Fig. 621, c.) Miocenic.
Porous and vesicular, of light weight though very thick. Much

Fic. 621. a, 4, Ostrea trigonalis, lower valve, K % 3; ¢, O. percrassa, upper
valve, X 4%. (Md. Surv.)
like O. trigonals from which it differs in its somewhat larger size
and broader outline.
New Jersey, Maryland (Calvert), Florida.

— {se 7

——

PELECYPODA—PRIONODESMACEA. 467

LXXX. GryPH#A Lamarck.

Sessile when young, free when adult. Left valve strongly
arched, with beak incurved usually nearly in plane of median line
and usually not much deflected to right or left. Right valve flat
and opercular ; its beak inconspicuous and not deflected or coiled.
Surface usually marked only with concentric growth lines. Muscle
impressions as in Ostrea. Less irregular than Ostrea, with beak
of lower valve more produced and recurved. It usually also
lacks the strong radial plications often seen in Ostrea and Exogyra.
Also differs from Exogyra in that the beak of the lower valve
curves upward instead of laterally. Young Grypheas are often
much like Ostreas. Jurassic—Tertiary.

faeeenel marrow, widening but little from beak. .........015.0s.ccncnbersecencscnsspaccesecss iy
PEPER GML SITIES DFESENE 25 2h: v2 eine fesaae an chivachotinds'ndeeataxs Bedhead Sopataenevs «ttacast i.

i> loreal sinus, bepinning near, beaks; o.. oi clas caese edie ces 290. G. mucronata,

I. Dorsal sinus beginning some distance from beak........... 286. G. marcout.
Meena ML SUAS SIOSETIE Soa < ina vic ine anes <Welga oOo ees Souclad va spns shaven oo 285. G. mexicana
eeetren road, widening rapidly from beak... ......cccseccsaseccsscssneces ccecscocecesonsses HL:
PUIICSOTUR GOD BEESON Ey ..-c 5s Sitiae soatnsnesdvieatvis canta sedusssasiads sar 288. G. navia.
Semeetirial Keel BDSENE ain neisn ine adc adap evtaGnewranas [SRN aea REMORSE SPS este sed ceeeeagh ps 2.

2. Lower valve winged.............00+ pene ehoMemaa ee teateal deine wo Oia ie. rates a.

Bere TOS TON) PRILM SICIOE). it 6 oaycinnin crass acta a Sdans meh Odden dacs ndipeiteds anaes Il.

II. Small (less than 2 inches nig) Peta duc saae 289. G. washtitaensts,

. Large (over 2 inches high); lower valve nearly circular, slightly
compressed into wings at cardinal extremities.
292. G. mutabilis.

Ere MEO NS DOSCEMMGL S600 Sun tose Ta Jaen aideah ata Gio tectat en dalase siev ne sieseoun ra 22.

22, Wing not separated from rest of shell by deep sulcus; surface

marked with obscure concentric lines...... 291. G. vesicularts.

22. Wing separated from rest of shell by deep sulcus ; surface marked

Will TUMOSE CONCENUMIC NES 5. i. i50c beer vesende'es 293. G. convexa.

Seer GL. SAIVS NOt WINGED. cys vous oc canes edadcuuvesevsncnsate oda andounvescvssdscsess b.

6. Beak usually somewhat twisted............ 287. G. aca and vars.

emt AVON os Peas aves votahact ote de ovawanrad ieee ask 294. G. newberryt.

285. G. mexicana Felix. (Fig. 622.) Upper Jurassic.

Left valve with strongly curved beak which is flattened poster-
iorly. Growth lines usually thickened into wave-like elevations.
Right valve small, flat, and triangular.

Malone of Texas; also Mexico.

286. G. marcoui Hill and Vaughan. (Fig. 623.) | Comanchic.
Beak narrow and incurved. Dorsal sinus distinct.
Fredericksburg of Texas.

468 NORTH AMERICAN INDEX FOSSILS.

287. G. corrugata Say. (Fig. 624.) Comanchic.

Lower valve boat-shaped and thick. Growth lines coarse.
Dorsal sinus distinct. Beak usually slightly twisted toward dor-
sal margin. Upper valve somewhat triangular and thick.

Fic. 622. Grypha@a mexicana. a, side view of a small lower valve; 6, a larger
lower valve. (After Cragin. )

Washita of southwestern North America from Kansas to Mexico.
Especially common in the Preston of Texas.

Three varieties of G. corrugata have been recognized, distin-
guished mainly by differences in size.

Fic. 623. Gryphea marcout. (After Hill.)

287a. G. corrugata var. hilli Cragin. Comanchic.
Small, resembling the young of G. corrugata.
Very abundant in the Belvidere beds of Kansas.

2870. G. corrugata var. tucumcarii Marcou. - Comanchic.
Large.

.

es ees SS ee TF Oe Se

— ae

Ss

PELECYPODA—PRIONODESMACEA. 409

Kansas, Oklahoma, New Mexico, Texas.

287c. G. corrugata var. belviderensis Hill and Vaughan.
Comanchic.

Large but differs from ¢ucuwmcaru in its more triangular and
flattened outline.
Comanchic of southern Kansas and Texas.

SS

Fic. 624. Gryphea corrugata. Exterior and interior of lower valve, & %.
: (After Hill and Vaughan. )

288. G. navia Hall. (Fig. 625, d, ¢.) Comanchic.

Lower valve distinguished from G. corrugata which it resembles
in beak and surface characters, by its smaller size, the possession
of a dorsal carina separated from the dorsal sinus by a depressed
area which at times is marked by slight ridges and by having a
dorsal wing, produced by the expansion of the valve at the margin.

Characteristic of the Washita from Kansas to Mexico. Ex-
ceedingly abundant in the Kiamitia clays of Texas and Oklahoma.

289. G. washitaensis Hill. (Fig. 625, a—c .) Comanchic.
Thin. Lower valve with well developed wings on both sides.
Growth lines fine.
Characteristic of the middle Washita of Texas, usually asso-
ciated with Ostrea carinata and occurring in great sheets.

290. G. mucronata Gabb. (Fig. 626.) Comanchic.

Similar to G. marcouz but larger, heavier, and with less abruptly
constricted beak. The dorsal sinus begins farther up the umbo
than in G. marcoui and the growth lines are coarser.

470 NORTH. AMERICAN ANDEX: FOSSILS,

Fic. 625. a-c, Gryphea washitaensis; d, e, G. navia. (After Hill and Vaughan. )

Abundant in the upper Washita (Denison and Buda) of Texas,
and in Sonora.

291. G. vesicularis Lamarck. (Fig. 627.) Comanchic—Cretacic.

Fic. 626. Gryphaea mucronata. (After Hill.)

PELECYPODA—PRIONODESMACEA. 471

Differs from G. convexa in absence of sulcus and in smooth
surface.
Washita of Mexico. Cretacic: Delaware, Texas and Mexico

and west to Montana. Also Europe.

292. G. mutabilis Morton. (Fig. 628.) Cretacic.
Lower valve depressed-convex and comparatively thin.

Fic, 627. Gryphea vesicularis. Lower and upper valves. (Md. Surv.)

Especially characteristic of Marshalltown of New Jersey.

293. G. convexa (Say). (Fig. 629.) Cretacic.
Lower valve with posterior ear separated from the rest of the

Fic. 628. Gryphea mutabilis. (N. J. Pal., I.)

472 NORTH AMERICAN INDEX + FOSSILS,

shell by a conspicuous sinus, extending from the beak obliquely
backward. Upper valve flat.
Forms a conspicuous bed in the middle of the Navesink of

Fic. 629. Gryphea convexa, X 7%. (N. J. Pal., I.)

New Jersey; also in Marshalltown of New Jersey. Also in
Ripleyan of Alabama and Mississippi.

294. G. newberryi Stanton. (Fig. 630.) Cretacic.
Outline rounded. Beaks broad. Surface marked with con-

~ Tana

Fic. 630. Gryphea newberryt. (After Stanton. )

centric lines which occasionally become somewhat lamellose.
Coloradoan: Colorado, Utah, New Mexico, Arizona, Texas.

LXXXI. Exocyra Say.

Shell massive. Left or under valve always much the deeper.
Right or upper valve-usually flat. Shell fixed by the left valve.
Beak of lower valve always turned strongly backwards and usually
more or less spiral. Beak of upper valve inconspicuous but de-
flected or spiral. Upper Jurassic—Cretacic.

—-.s

PELECYPODA—PRIONODESMACEA. 473

Perrurtace smooth: or: nicarly (S0'.i0c sie vicass teas bcos ceded onunccerseeaar eee a caer eee fs
I. Larger valve marked with broad furrow .................06+ 298. £. suborbiculuta.

i, harger Valve not farrowed.s5 jgsccvicstavncudtnsies voeceeees obese 300. £. leviuscula.

B. Surface marked with prominent concentric lamell2..............ccecceeecescseeeeecees Il.
Riles ell Latte, .0 sa tehs'a cciwaamaess aeencignen sew deste decedent nepsn ces 301. L. ponderosa.

Be SILA SEOUL: co. cas ad cme Seine s cleus mh guage came eemre eee mea lktiasaci dee eae 297. £. arietina.

C. Surface marked with distinct radiating ribs or wrinkles................ccceeceeeeeees ETT.
en IN oo ace ain's awed swunsean bs sdasedeaccwnlh ales aa asses caked SRaM ANUP kasama lau I.

Pom eee ARAL M5. ds evn dincs tabness panene’s 295a. & texana var. weatherfordensis.

1g SEL A Cs Sg SA a ae San Oe Rea EPR PD Re A 4 MMe Va Mies h Poprt tn. ee Ha a ine yates a.

a. Shell with obtusely rounded umbonal ridge.......299. £. columbella.

a. Shell with angular umbonal ridge...................ceeeees 296. £. plexa.

MLS 6 Si. ocd ee xeanale suhadaidcnbasi ink cla boshimonnlccdnonabecnen web cacatinind rawew manners les 2:

2. Valves very unequal, the lower very convex, the upper nearly flat.
302. £. costata.

mae Volves subequal, fattened 5. oc. ci ccn cccccassgetwacesaveccssogess's 295. £. texana.

295. E. texana Roemer. (Fig. 631-632.) Comanchic.

Valves subequal, thick. Surface marked with unequal radiat-
ing ribs.

Widely distributed in the Comanchic of Texas, being especially

S:
S

(

Fic. 631. Lxogyra texana. Opposite valves. (After Hill.)

abundant in the Fredericksburg. Also in Fredericksburg and
Washita of Mexico.

295a. E. texana var. weatherfordensis Cragin. Comanchic.
Small, flattened, with somewhat semicircular outline. Lower

474 NORTH AMERICAN INDEX FOSSILS.

valve usually marked with plications which are delicate on the
posterior slope and somewhat tuberculate on the anterior.
Trinity of Texas.

296. E. plexa Cragin. Comanchic,
Lower valve divided into an anterior and’a
posterior slope by an angular ridge. Both
slopes usually marked with radiating lines or
wrinkles.
Comanchic: Texas (Fredericksburg and
Washita).
297. E. arietina Roemer. (Fig. 633.)
Comanchic.
Larger valve inflated, tortuous. Smaller
valve flat, a plane spiral. Without plications.
Washita: Texas, Mexico.

298. E. suborbiculata (Lamarck). (Fig.
635, ¢.) Cretacic.

Fic. 632. Zxegyra Tower valve marked with a broad furrow,
texana. 'The two valves

Se

ate extending obliquely from the umbo to the
in conjunction. ( After ‘
Hill. ) postero-basal margin. Surface smooth.

Benton: Colorado (Pugnellus sandstone).
299. E. columbella Meek. (Fig. 634, a—c.) Cretacie:
Small, left valve marked by radiating ribs. Right valve flat,
oval and smooth.
Colorado: New Mexico, Texas (Benton) ; also Dakota of Texas.

Fic. 633. LZxogyra arietina. (After Hill.)

300. E. leviuscula Roemer. (Fig. 634, 2.) Cretacie:
Both valves smooth except for concentric growth lines. Smaller
valve flat and nearly circular.
Very common in the Austin of Texas; also Benton of Kansas
and Utah.

.

- +, .

SE

Se ee | oe

—— eae ee CUFT

ey =”

FIG. 634.

475

fe vat S

PP.

a-c, Exogyra columbella, lower umbonal and upper views; ad, Z.
leviuscula, lower valve. (After Stanton. )

Fic. 635.

a, 4,

Lxogyra ponderosa; c, E. suborbiculata, lower valve. All x %.
(After Stanton. )

476 NORTH *AMERICAN SNDEX = FOSSELS:

301. E, ponderosa Roemer. (Fig. 635, @, 0.) Cretagie:
Left valve marked with strong concentric lamelle, fine concen-
tric striae and obscure radiating ribs. Right valve with horizontally
spiral umbo ; concentrically laminated.
Ripleyan of New Jersey (Marshalltown), Alabama, Arkansas.
In the Coloradoan of Utah, Texas (Austin) and Mexico.

Cretacic.

Fic. 636. Exogyra costata. Lower valve, x 4%. (After White.)

Differs from F. ponderosa in being strongly costate and in lack-
ing the lamellose extensions.

New Jersey (especially characteristic of Navesink ; also in Red
Bank and Tinton), Delaware, Maryland (Monmouth) and Gulf
region to Texas and San Luis Potosi.

LXXXII. AmniGcenia Hall.

Equivalve, very inequilateral, subelliptical, with very short an-»
terior end and prolonged and wider posterior end; both extremi-

PELECYPODA—PRIONODESMACEA. 477

ties rounded. Beaks low and appressed. Hinge line long, gently
arcuate. Umbonal slope not defined. Surface marked by con-
centric strize which become lamellose on the posterior portion of.
the shell. Teeth obscure. Hinge line marked by one or two
longitudinal lateral folds. Ligament external, extending more
than half way from the beak to the posterior end. Pallial line
simple. Lived in fresh water. Devonic.
303. A. (Archanodon) catskillensis (Vanuxem). (Fig. 637.)
Devonic.
Shell large, elongate-elliptical.
Oneonta: New York. Catskill: Pennsylvania.

Fic. 637. Archanodon catskillensis, X 24. (Pal. N. Y., V.)

LXXXIII. Natapires Dawson. (Anxthracoptera, Salter.)

Inequivalve, obliquely triangular, very inequilateral. Anterior
end oblique, forming a small lobe anterior to the umbonal ridge.
Hinge line straight. Hinge plate striated, with an obscure car-
dinal tooth, that in the left valve being anterior, and that in the
right posterior. Umbos small, inconspicuous, almost terminal.
Byssal notch always present. Shelli very strong anteriorly, fragile
posteriorly. Surface covered with flat concentric lamellz. Pallial
line entire, represented by a series of small pits. Brackish or
fresh water ; attached by byssus. Carbonic.

304. N. carbonarius Dawson. (Fig. 638, ¢.) Carbonic.

Hinge line more than half the length of the shell. Beak in an-
terior fourth of hinge line. Anterior margin abruptly rounded ;
basal margin nearly straight, with a slight sinus ; posterior margin
broad and regularly rounded. Shell usually much distorted by
pressure. Length one inch or more. Type of genus.

Exceedingly abundant in the Coal Measures of Nova Scotia and
Cape Breton.

478 NORTHAM ETRICAN TNDEX «FOSSILS.

LXXXIV. ANTHRACOMYA Salter.

Differs from Vazadites in posterior end being produced, ex-
panded, and usually truncate. Hinge with narrow internal ridge
parallel with the edge of the valve in its posterior portion. Hinge
plate not striated ; an oblique diagonal ridge passes from the umbo
downwards and backwards. Differs also in being equivalve, with
larger and more conspicuous umbos. No byssal notch present.
Carbonic. >
305. A. elongata Dawson. (Fig. 638, a, 0.) Carbonic.

Umbos less anterior than those of Wazadites carbonarius.

Fic. 638. a, 6, Anthracomya elongata, nat. size and enlarged; ¢, d, A. levis, nat.
size and enlarged ; e, Waiadites carbonarius. (After Dawson.)

Nova Scotia, Cape Breton.

306. A. levis Dawson. (Fig. 638, ¢, d.) Carbonic.
Less oblique than preceding ; beak more nearly central.
Coal Measures of Nova Scotia.

LXX XV ONYAssSA Hall:

Beaks small, anterior. Hinge line long and arcuate. Oblique
median depression and umbonal ridge often present. Surface
concentrically striated. Hinge with several irregular and coales-
cent teeth anteriorly and with 1 to 4 elongate lateral teeth pos-

Fic. 639. Myassa arguta.

teriorly. Ligament external and inconspicuous. Pallial line
simple. Devonic.

307. N. arguta Hall. (Fig. 639.) Devonic.

>
et

PELECYPODA—PRIONODESMACEA. 479

Distinguished by its arcuate, subelliptical form and sinuate basal
margin. Growth lines lamellose.
Hamilton: New York, Ontario.

LXXXVI. Unio Retzius.

Oval or elongated. Epidermis thin. Umbos more or less
anterior. Surface smooth, concentrically striated, corrugated, or
rarely spiny. Hinge line with heavy, amorphous, radial, pseudo-

Se Se eee eee Oe ee Th oY Ue or

Fic. 640. a-c, Unio vetustus; d, e, U. belliplicatus ; f, g, U. dane; h, U sen-
ectus ; 1,7, U. holmesianus. (After White.) All & ¥%.

cardinal and lateral teeth. Ligamentexternal. Pallial line simple.
Fresh water. Jurassic—Recent.

308. U. vetustus Meek. (Fig. 640, a—c.) Cretacic.
Beaks marked with regular concentric ridges that usually end
at the oblique umbonal ridge which extends from the umbo pos-
teriorly: a second ridge present between this and the cardinal
margin. Remainder of valve marked merely with growth lines.
Length about three inches.
Bear River: Utah, Wyoming, Idaho.

309. U. belliplicatus Meek. (Fig. 640, d, ¢.) Cretacic.

————— er ee ee eee

j
;
:

480 NORTH, AMERICAN, INDEX FOSSILS.

Umbonal slope with 5 to 8 (or more) coarse, rounded, rather
irregular folds or plications, which become obsolete in the last
built portion of the shell.

Bear River beds of Wyoming, etc.

310. U. subspatulatus Meek and Hayden. Cretacic.
Surface as of U. vetustus but differing from that species in more
arched hinge line, more anterior beak, straight base and general
proportions.
Judith River beds of Montana, Assiniboia.

311. U. dane Meek and Hayden. (Fig. 640, /, g.) Cretacic.
Similar to U. subspatulatus in size and form but its convexity is
greater, the beaks not so anterior, and it is unsculptured.
Alberta (Lower Belly River), Montana and Assiniboia (Judith
River); also Lower Laramie of Wyoming and Alberta.

312. U. senectus White. (Fig. 640, 4.) Cretacic.
Thin. Cardinal and lateral teeth separated by a considerable
space. Posterior to the line running from the beak to the pos-
terior basal angle the surface has numerous small crenulated un-
dulations. In front of this the surface is marked only with growth
lines. :
Montana (Judith River), Assiniboia (Lower Belly River); also
Laramie of Alberta.
313. U. holmesianus. (Fig. 640, 2, 7.) Cretacic.
Basal (latest built) portion of shell marked with only concentric
growth lines; the rest of the shell covered with radiating cost
of close-set rhombic papiilze. A strong medial sinus present.
Laramie: Wyoming, Utah.

LXXXVII. ANODONTA Cicer

Shell like Unio externally but usually much thinner and
smoother. Hinge without teeth. Fresh water. Cretacic—
Recent.

314. A. propatoris White. Cretacic.

Elongate, subelliptical, moderately convex. Beaks small,
slightly elevated above the hinge line. Hinge line long, straight.
Ventral border broadly convex ; front regularly rounded from the
base to the antero-dorsal border which is more abruptly rounded
to the hinge line. Postero-dorsal border oblique and slightly

a

PELECYPODA—PRIONODESMACEA. 481

convex. Surface only concentrically striated. Average length 2
inches ; height slightly over 1 inch.
Judith River: Montana, Assiniboia. Laramie: Wyoming.

LXXXVIII. LyroprEsma Conrad.

Moderately convex, equivalve, inequilateral. Beaks small,
anterior to the middle. Posterior umbonal slope usually promi-
nent. Surface concentrically striated. Hinge with 6 to 8 promi-
nent, subequal, transversely striated teeth radiating regularly
from the beak and placed on a thick plate. Posterior adductor

Fic. 641. a-d, Lyrodesma major, a, right valve; 4, cardinal view, slightly en-
larged ; c, vertical section through valve at beak showing thickness of hinge plate and
reason why the beaks in internal molds are widely separated ; d, interior of right valve ;
é, f, L. acuminatum, right valve and its hinge, fx 3. (After Ulrich. )

scar larger than anterior. Pallial line slightly sinuate posteriorly.
No ligament area present. Ordovicic and Siluric.
315. L. acuminatum Ulrich. (Fig. 641, e, /) Ordovicic.
Posterior cardinal slope with four or five radiating lines.
Teeth 6, the central ones curved backward; the anterior ones
short.
Stones River: Kentucky. Black River: Minnesota.
316. L. major Ulrich. (Fig. 641, ad.) Ordovicic.
Shell much prolonged posteriorly. Posterior umbonal and
cardinal slope marked with fine radiating lines. Hinge with 6
teeth.
Cincinnati Group : Ohio, Minnesota.
317. L. poststriatum (Emmons). Ordovicic.
Distinguished by its obliquely truncate posterior extremity and
strongly striated posterior umbonal slope.
Trenton—Lorraine: New York, Pennsylvania.

482 NORTH AMERICAN INDEX FOSSILS.

LXXXIX. Scuizopus King.

Shell thin, ovate, often tending toward quadrate, longest pos-
teriorly. Right valve with two teeth; left with three. Surface
marked with concentric striae or nearly smooth. Muscular im-
pressions two; the anterior with a small radial buttress. Pallial
line simple. Devonic—Permic.

318. S. chemungensis (Conrad) (S. appressus Conrad). (Fig.
642, 0.) Devonic.
Surface covered with fine concentric striz which often strengthen

into varices near the base.

Hamilton: New York. Chemung: New York, Pennsylvania.

da

Fic. 642. a, Schizodus gnadrangularis,; 6, S. chemungensis,; c, S. gregarius; a,
S. rhombeus. All left valves. (N. Y. Surv.)

319. S. gregarius Hall. (Fig. 642, c.) Devonic.
Distinguished by its small size and elongate form.
Chemung Group: Pennsylvania.

320. S. rhombeus Hall. (Fig. 642, a.) Devonic.
Distinguished by its nearly quadrate form. Below the medium
size but larger than S. gregarius.
Chemung Group: New York, Pennsylvania.

321. S. quadrangularis Hall. (Fig. 642, a.) Devonic—Carbonic.
Differs from S. chemungensis in its more quad-
rate form and more nearly central beaks.
Chemung Group: New York. Waverly:
Ohio. Coal Measures: Pennsylvania.

322. S. medinaénsis Meek. (Fig. 643.)

Fic. 643. Schizo- Mississippic.
dus medinaénsis. Subtrigonal. Surface nearly smooth.
a ie Waverly : Ohio, Indiana.

323. S. cuneatus Meek. (Fig. 644.) Mississippic—Carbonic.

PELECYPODA—PRIONODESMACEA. 483

Large. Beaks erect, incurved.
Mississippic : Nevada. Carbonic: Pennsylvania—Colorado.

324. S. curtus Meek and Worthen. Carbonic and Permic.

Fic. 644. Schizodus cuneatus. (Ohio Pal., II.)

Small, not exceeding } inch in length, nearly circular, with
very elevated and nearly central beaks.
Coal Measures: Indiana—Missouri. Permic: Kansas (Marion).

Fic. 645. Schizodus wheelert. a, 6, internal molds; c¢, exterior of smaller left valve
(Ind. Surv.)

325. S. wheeleri Swallow. (Fig. 645.) Carbonic—Permic.

Differs from S. chemungensis in outline, especially in the ob-
liquely truncated posterior portion.

Coal Measures: Pennsylvania-New Mexico. Permic: Kansas,
Wyoming?

XC. Triconia Bruguiere.

Thick, trigonal, very inequilateral, with rounded anterior and
produced and angular posterior margin. Generally marked with
a ridge extending from the umbos to the posterior border, cutting
off the posterior dorsal area which has a different ornamentation.

484 NORTH AMERICAN INDEX FOSSILS.

Beaks nearly’ terminal anteriorly, directed posteriorly. Surface
bearing rows of tubercles or radiating or concentric ribs. Cardi-
nal teeth two in the right valve; three in the left. Ligament ex-
ternal. Pallial line simple. Jurassic—Recent.
326. T. quadrangularis Hall & Whitf. (Fig. 646.) Jurassic.
Trigonal to subquadrangular, with two
sets of ridges making an acute angle with
each other.
Upper Jurassic of Wyoming, Dakota,
etc,

Ce ae taffi Cragin. Comanchic.
Very large (length and height each

Fic. 646. eratiny ae over 3 inches), rounded-subquadrate.
rangularis. (After Hall and Posterior dorsal area ornamented with
wae numerous, parallel, oblique ridges sepa-
rated by much broader interspaces ; the ridges near the beak be-
come resolved into:series of small granules. The rest of the sur-
face covered with close rows of small tubercles.

Trinity of Texas.

328. T. emoryi Conrad. (Fig. 647.) Comanchic.
Ribs 30 or more, strong and tubercled, becoming indefinite pos-

Fic. 647. Trigonia emoryi. (After Shattuck, )

teriorly ; they change direction in passing over the posterior dorsal
area and again over the escutcheon.
Fredricksburg and Washita : Texas, Mexico, Oklahoma.
329. T. equistriata Gabb. Comanchic—Cretacic.
Small, trigonal, elongate. Beaks prominent. - Cardinal margin

PELECYPODA—PRIONODESMACEA. 485

nearly straight and sloping posteriorly. Shell truncated pos-
teriorly. Surface crossed by regular broad concentric ribs with
flat and equal interspaces. An angular ridge extends from the
beak to posterior basal margin.

Horsetown and Chico: California, Oregon.
330. T. evansana Meek. Cretacic.

Somewhat similar to 7. eufaulensis in outline, convexity, and
strongly incurved beaks ; but its
beak is more elevated, its average ; ioe
length is 13 inches and height eS ‘ ay /
12 inches, its posterior basal , .
margin is straight or slightly
convex, not concave, its ribs are
18 to 23 and proportionally
much narrower than the inter-
spaces and less curved than in
T. eufaulensis.

Chico: California, Oregon.

Fic. 648. Zrigonia thoracica. (After
331. T. thoracica Morton. (Fig. Weller, N. J. Surv., Pal., IV.)

648.) Cretacic.

Ribs nodose, about 15, the anterior ones curving strongly for-
ward. The posterior dorsal area occupied by 12 to 14 subangular
ribs.

New Jersey (very abundant in Marshalltown; also in Wenonah
and Navesink), Gulf region.

332. T. eufaulensis Gabb. (Fig. 649.) Cretacic:

Fic. 649. Trigonia eufaulensis, (After Weller, Pal. N. J., IV.)

Drawn out posteriorly. Ribs angular, 12-14.
New Jersey (Merchantville-Wenonah), Gulf region.

480 NORTH AMERICAN INDEX FOSSILS.

XCI. AVICULOPECTEN McCoy.

Pectiniform, inequilateral, inequivalve, with right valve usually
less convex than the left. Hinge line straight with both anterior
and posterior ears. Surface usually radially sculptured. Liga-
ment internal, extending to both sides of the beak in many shallow
grooves roughly parallel to the long hinge line. Resiliifer present.
Teeth absent. Pallial line simple. Siluric—Carbonic.

A. Latge,— exceeding 12. inchesim- diameter... 25: o.cseicndbessve se nes peen en eeeeeea | Is
ie Strise fascteitlates sts poeta, cate ca taniaese aces aeteweane ae 343. A. providencesis.
LS SER. DENY Lhe cae eset mexeeeee ten scks scecetcea Jahres ob aU Ceegni eae aa 335. A. scabridus.
1. Strieegumple and Smooth, sie sea ticensa cates sanain ends cede edecntevs 334. A. princeps.
B. Of medium’ size, — about 1 inch’ an diameter. ..<<) yeoccec oc. its aes II.
LE: (RAYS Itt BERS OM MW ae cece ty ck acnbs mseseucccnextuaeaee Ree 337. A. aduplicatus.
BY, IRaYS ‘SPH. ceca ss cuatenak at snenteses oone eens ease 354. Acanthopecten carboniferus.
If, Rays in. bundles: ofirregular size: vascesasaicsnactevdpuenpeten 333. A. fasciculatus.
II. Rays 4-6, roughened by scales and separated by finer striz...............200008 i
I. Ribs prominent only on lower half of shell.................. 352. A. vanvleeti,
I. Ribs prominent from near the beak to the margin........... 351. A. maccoyt.
II, Rays of nearly but not quite equal size and crossed by crowded and regular
concentric striz ; hinge-line crenulated..........364. Crenipecten winchellt.
II. Rays'of equal size but-varying lengths ...2 50.000. Sov cseess vseckinen wees eee ae
2. Beak acute and projecting above the hinge line...... 353- A. oklahomaensis.
2. Beak nearly a right angle and scarcely projecting above the hinge line...a.
Mats: PROMMNNGHE too. eds sasca tae cde tues al -coureesranes 349. A. occidentalis.
ir CAPS SINAN pss ia Tegane tote kon esee ne uae OR STe 345. A. curtocardinalis.
Il. Rays regularly alternating............... ioasiaes se Vesey as vanseasianes cet pee ane: atin ek
3./ Smaller rays only neat iret wes. cscs sseuw tas caamane eae 348. A. weberensis.
3. Smaller rays extending néarly to beak... 6.02. ..cssasne-Cde-0ane'.nneeee eee b.
be. Small vays Several 2.2 s caitad beacave'des naewees eae. 346. A. occidaneus.
é, Small rays oneun broad ‘space...< 1...veiioiincssac-s anon! 347. A. parvulus.
II. Without rays, marked only by concentric lines............ 344. A. interlineatus.
. small, less than 1 inch ‘in, greatest diameter... .../:ccacerscu-ennceevecnes espana IIl.
III. Radiating stric fine and numerousS..........2.5.2ccevenes snecsdaseaees see eaten 4.

4. Radii crossed by fine concentric lines, producing a cancellated appearance..c.
c. Length and height nearly equal (about } inch)....342. A. pellucidus.
c. Height slightly exceeding length (about 4 inch wide).
| 338. A. cancellatus.

4. Concentric strie absent or not prominent... ..5.<.c0.2002006-sanenps teeta d.

@. Lengthand height nearly equal... :sistivtcceae eect en eks 339. A. carol.

d. Height:exceeding lene). ii ibs ekcatencnener conan ee eli 336. A. striatus.

III. Radiating striz rib-like and alternating in length.............2..s.00sscesns aan 5.

5. Length and ‘height/aboutiequal |... ..2.. done evens senseesieusmensea cues een é.

e. Posterior margin nearly straight................. 341. A. rectilalerarius.

#:, Posteriox marain anowlar. .5255,s, cs sick ba noacet semen tne nnn 340. A. coxanus.

5, deleightiexceeding Wem. ices a onse Pack oe va vests feta n as 350. A. germanus.

333. A. fasciculatus Hall. (Fig. 650, g.) Devonic.

Axis of shell quite oblique to the hinge line. Surface including

487

PELECYPODA—PRIONODESMACEA.

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ae

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488 NORDH AMERICAN ANDEX FOSSILS,

Hamilton: New York, Ohio, Kentucky, Indiana, Michigan.
335. A. scabridus Hall. (Fig. 650, /) Devonic.

Differs from A. princeps in its very obtuse angle at the hinge
line, and especially in the imbricating growth lines which usually
form short, almost tubular spines when passing over the rounded

rays.
Hamilton: New York.
336. A. striatus Hall. (Fig. 650, d.) Devonic.

Small; surface including ears covered with fine regular and
closely arranged rays.

Chemung: New York, Pennsylvania.
337. A. duplicatus Hall. (Fig. 650, a.) Devonic.

Beaks obtuse, prominent. Ears small. Surface including ears
covered with regular duplicating rays crossed by fine concentric
striz ; umbo nearly smooth.

Chemung: New York, Pennsylvania.

338. A. cancellatus Hall. (Fig. 650, ¢.) Devonic.
Height slightly greater than length. Lateral margin of anterior
ear rounded. Surface including ears marked with fine rays crossed
by fine strize, giving the shell a cancellated appearance.
Chemung: New York.
339. A. caroli Winchell. (Fig. 650, c.) Mississippic.
Differs from A. s¢rzatus in its more circular form, obtuse beak,
and stronger radii. |
Waverly : Ohio, Iowa.
340. A. coxanus Meek and Worthen. (Fig. 651.) Carbonic.
Radiating ribs alternating in size, the smaller ones
dying out before reaching the hinge. Concentric striz
fine and close.
Coal Measures: Pennsylvania—Oklahoma and Ne-
braska.

Fic. 651.
Aviculopecten 341. A. rectilaterarius (Cox). Carbonic.
Caceres, Height and length about equal (about # inch). An-
beam al, terior ear separated by an indistinct furrow from bod
VI/II.) P y 3

of shell. Posterior ear not defined, large. Posterior
margin nearly straight. Radiating striz somewhat rib-like, crossed
by concentric lines. Differs from A. coranus in its slightly larger
size; larger posterior ear and straight posterior border.

PELECYPODA—PRIONODESMACEA. 489

Kentucky, Indiana, Illinois, Kansas, Colorado (Hermosa), Okla-
homa (Poteau Group).

342. A. pellucidus Meek and Worthen. Carbonic.
Very small, somewhat oblique, extremely thin and fragile.
Ears subequal; the anterior acutely angular. Surface cancel-

lated by the concentric and radiating striz@ (12 radii in 5/5 inch at

Fic, 652, Aviculopecten providencesis. (Kan. Pal., VI/II.)

anterior margin). Length and height about equal (4 inch).
Hinge line shorter than length of shell below.
Hlinois, Colorado.
343. A. providencesis (Cox). (Fig. 652.) Carbonic.
Large. Striz in bundles of 3 to 5 which are separated by
broad grooves. :
Kentucky, Indiana, Missouri, Kansas.

344. A. interlineatus Meek and Worthen. (Fig. 653.)
Carbonic.
Surface marked only with strong concentric ridges and with
fine concentric strize between.
Ohio—Missouri, Arizona.
345. A. curtocardinalis Hall and Whitf. (Fig. 654, 2.)
Carbonic.
Smaller than A. occidentalis, with smaller ears and bifurcating
simple striz.

490 NORTH AMERICAN INDEX FOSSILS:

Upper Carbonic of Utah, Wyoming and elsewhere in west.
346. A. occidaneus Meek. (Fig. 654, 0.) Carbonic.

Fic, 653. Aviculopecten interlineatus. (Kan, Pal., VI/II.)
Fic, 654. <Aviculopecten curtocardinalis, K 2 (left); A. occtdaneus. (After Hall
and Whitfield, and after Meek. )
Slightly more oblique than preceding ; striz alternating, 2 to 4
smaller between larger.
Occurs with preceding.

347. A. parvulus Hall and Whitf. (Fig. 655, a.) Carbonic.

—

Fic. 655. Aviculopecten parvulus, X 3 (left); A. weberensis.
(After Hall and Whitfield. )

More elongate and with larger ears than preceding, large ribs
sharp and strong, smaller generally only one. |

Occurs with the preceding.
erensis Hall and Whitf. (Fig. 655, 4.) | Carbonic.

Ears more pronounced than in preceding,
plications smaller, several near front only.

Occurs with preceding generally.

349. A. occidentalis (Shumard). (Fig.
656.) Carbonic—Permic.
Both valves crossed by distinct radiating

ribs, those of the left valve the more prom-

inent. Whole valve crossed by concentric
growth lines. Ears large ; umbo rectang-

Fic. 656. Aviculopecten
occidentalis, left valve. (Ind. ular to acute.
Surv. ) Common in Carbonic rocks of the United

States from Pennsylvania and Kentucky, westward and southward

7,7

PELECYPODA—PRIONODESMACEA. 491

to Utah and Arizona. Ranges from Lower Coal Measures to the
Upper and into Permic in Kansas and Texas.

350. A. germanus Miller and Faber. (Fig. 657.) Carb.—Permic.
Radiating ribs about 12, alternating with about the same num-
ber of shorter ribs, and all separated by wide, flattened spaces.

Fic. 657.
Fic. 658. Aviculopecten maccoyt. (Kan. Pal., VI/II.)

Coal Measures: Kentucky, Kansas, Oklahoma. Permic: Kansas.

351. A. maccoyi Meek and Hayden. (Fig. 658.) Car.—Permic.
Ribs 3 to 6, roughened by scale-like projections and separated
by smaller striz.
Coal Measures: Kansas, Oklahoma. Permic: Kansas. Also
Carbonic of New Mexico.

352. A. vanvleeti Beede. (Fig. 659, c.) Permic.

Fic. 659. a, 6, Acanthopecten carboniferus ; left and right valves, (Ind. Surv.)
c, Aviculopecten vanvileeti. (Kan. Sci. Bull. )

Differs from A. maccoyi in larger size and in the larger rays
which are prominent only when half way down the shell.

Upper Permic: Oklahoma (Whitehorse), Texas (Quarter-
master).

492 NORTHOAMERICAN “INDEX FOSSILS.

353. A. oklahomaensis Beede. | Permic.

Differs from A. occidentalis in its frequently smaller angle at the
beak, and in the more pronounced concentric lamelle.

Upper Permic: Oklahoma (Whitehorse), Texas (Quarter-
master).

XCII. AcANTHOPECTEN Girty.

In surface characters distinguished from <Avzculopecten by its
large, angular plications, and spinose margin and growth lines.
Carbonic.

354. A. carboniferus (Stevens). (Fig. 659, a, 0). Carbonic.

Small; right valve less spinose, and less strongly plicate than
left. Type of the genus.

Distributed widely in the Coal Measures from West Virginia to
Colorado and New Mexico.

XCIII. Eucuonpria Meek.

Like Aviculopecten but with an unsymmetrical resiliifer beneath

the beak and with numerous pits on the two

sides of it unequal in number and shape.

Carbonic.

355. E. neglecta Geinitz. (Fig. 660.)

Carbonic.

Small, with concentric striz only on body

Fic. 660. Euchondrig Of Shell, but ribs on ears. Type of genus.

neglecta, right valve, <2; — Illinois, Iowa, Kansas, Nebraska, Missouri.

hinge greatly magnified,

showing oblique cartilage XCIV. PTERINOPECTEN Hall.

pone ase pus. ‘Differs from Aviculopecten’ in the longer
al. Tal... Ve

hinge line, and ears not well defined; from
Lyriopecten in its distinctly angular anterior ear. Devonic.

356. P. exfoliatus Hall. (Fig. 661, d.) Devonic.

Subrhomboidal. Left valve very convex ; right less convex.
Hinge line longer than shell below. Umbo prominent. Surface
of left valve marked with strong rays alternating with one or two

finer ones ; rays on right valve less strong.
Marcellus: New York.
357. P. intermedius Hall. (Fig. 661, c.) Devonic.
Differs from P. exfolatus in its greater obliquity, smaller umbo,
comparatively smaller posterior and larger anterior ear. Surface
rays more thread-like.

PELECY PODA—PRIONODESMACEA. 403

Hamilton : New York.
358. P. vertumnus Hall. (Fig. 661, a.) Devonic.
Depressed-convex. Surface marked with irregular, alternating,

flexuous and flattened rays, crossed by sharp concentric striz.
Hamilton: New York.

Fic. 661. a, Pterinopecten vertumnus, left valve; 6, P. suborbicularis; c, P.
intermedius; ad, P. exfoliatus; e, P. dispandus, right valve; f, g, P. undosus, right
and left valves. (Pal. N. Y., V.)

359. P. undosus Hall. (Fig. 661,49.) | Devonic.
Hinge line less than length of shell below. Valves depressed-

convex. Surface marked with many rays crossed by lamellose

growth lines and by 3-10 strong concentric undulations.
Onondaga and Hamilton of New York.

360. P. dispandus Hall. (Fig. 661, ¢.) Devonic.
Rays prominent, alternating with irregular finer ones, those of

right valve bifurcate. Rays crossed by strong concentric growth
lines, Ear with fold.

494 NORTH AMERICAN INDEX «FOSSILS.

Chemung Group: New York, Pennsylvania.
361. P. suborbicularis Hall. (Fig. 661, 2.) Devonic.

Depressed-convex. Extremities of ear angular. Rays regu-
lar, about equalling the interspaces, crossed by concentric lamel-
le. Differs from Lyriopecten orbiculatus in lacking broad ligament
area.

Chemung Group: New York, Pennsylvania.

XCV. LyRrIoPpEcTEN Hall.

Differs from Avzculopecten in the much less distinct ears and in

col

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Fic. 662. Lyriopecten orbiculatus. a, ligament area of right valve, < 3 ; 4, interior
of left valve; c, d, L. tricostatus, left valve and enlargement of surface. (Pal. N. Y., V.)

the rounded anterior ear, which is much smaller than the posterior
ear or absent. Devonic.

362. L. orbiculatus Hall. (Fig. 662, a, 4.) Devonic.

Length and height about equal. Beak obtuse. Surface

PELECYPODA—PRIONODESMACEA. 495

marked with regular rays crossed by sharp concentric lamelle.
Hamilton: New York.

363. L. tricostatus (Vanuxem). (Fig. 662, c, d.) Devonic.
Large ; beak pointed, not extending to margin of hinge. Rays

of three sizes, crossed by fine concentric lines.

Lower and Middle Chemung of New York.

XCVI. CRENIPECTEN Hall.
Like Aviculopecten but with hinge line composed of a long row
of alternating teeth and sockets. Carbonic.
364. C. winchelli Hall. (Fig. 663.) Mississippic—Carbonic.
Left valve moderately convex; beak acute, prominent; sur-

Fic. 663. Crenipecten winchelli. Left valve, and its upper portion enlarged to two
diameters. (Pal. N. Y., V.)

face with numerous rays. Right valve nearly flat; beak obtuse,
depressed ; surface marked with obscure rays.
Waverly: Ohio. Upper Coal Measures: Pennsylvania.

XCVII. Pecten Miller.

Nearly equilateral, very inequivalve, with well developed and
equal ears. One valve, usually the right, more convex than the
other. Surface usually marked with radial sculpture. Hinge
line straight, with a strong resiliifer, on each side of which inter-
locking ridges and grooves radiate in the adult. Byssal notch
always present in right valve, not very conspicuous. Single ad-
ductor muscle present. Carbonic—Recent.

The genus Pecten has been divided into very many subgenera,
the most important of which are: Chlamys, Camptonectes, Ento-
lium, Syncyclonema, Amusium. Under each are here placed those
species which are most widely designated by these subgeneric
names.

De OL valves Without radial ribs .cdesc. ccs chcesscvceduccesctcscvacccoccancevtv ceveceses ie
TI. Interior of valves marked with small radial ribs.................cccccceccecescccees ie
Se MRNUCHIO’, TINGS... cou eseavineas beebevausevshes sxe 395. P. (Amusium) alabamensis.

496 NORTH AMERICAN ANDEX FOSSILS.

Eo SO GHOr TIDS TO OF MGR. es aces ike seiteees 396. P. (Amusium) mortoni.
He: MESA AEE ROME DUIS , sans esc sinc es adaan cha paeWnees acts sasebe Ls tienda (ska nica tick once 2.
2. Ears subequal, diverging at a sharp angle above the beaks............. ... a.
a. Height greater than breadth....393. P. (Zmtolium) operculiformis.

a. Height and breadth subequal......... 392. P. (Entolium) aviculatus.

2. Ears not diverging at a sharp angle above the beaks,................0000000: é.
6. Sariace crossed ‘by concentric folds, 5.35. 250i. (0k c0s't cicadas dodocs pene Li;

11. Height greater than length ....394. P. (Syucyclonema) rigidus.

it. Height and length nearly= équal..........¢000 sse+saa00) seeeweaeeen aa.

aa. Folds extending across ears ............000- 368. P. conradi.

aa. Folds not extending across ears...371. P. burlingtonensis.

4, Surface not crossed: by concentric’ folds, 2. vss.j, «203. «ss Close seeeaaie eee 22.

22. BURIACE “SEHOGUN sc.) c¥. nace vce es cadceve te vest semtkpeincas'oo ety eee bb.

6e.¢ Mars subequal) 'ss. saies tabsecsiaaces err ea 369. P. simplicius.

6b. Ears unequal \....7..2.05.. 394. P. (Syncyclonema) rigidus.

22;, Surface: radially striated . 53. ...0.05-s0sss0 pends o> sve eters ce.

cc, Height:greater than breadth....; .......5.15/c.s0,0.0edetau ena ft:

t. Anterior ear narrow, separated by a deep byssal sinus
from body of shell.

390. P. (Camptonectes) pertenuistriatus.

ft. Anterior ear broad. Byssal sinus shallow.
372. P. argillensis.
cc. Height and breadth subequal

Tt. Shell oblique to hinge, large.

388. P. (Camptonectes) bellistriatus,
tt. Shell nearly erect...389. P. ( Camptonectes ) extenuatus.

#., Sortace of valves with radial ibs 205.5. ccci 344 cjnsivie <anvse sone cavieeuing shovee sae aeeeannan II.
I]. “Ribs, few, abeut-G;.-.40./. 3... e.8 Perr Mee eae ie apo 370. P. guinguenarius.

AES ARDS FRAIIY GP 5 aries dates clave Bento tg hiainclab's eaten Secaeled edie sas en, deta: Oe ieee

3. Rerbs stbequall 1. cu. o. Cidcct sada sintietdviins aalnacpatnteek av recier none snancaeeteeamennae c.

a, Maciel Mly, (StVe te s.27 Kiva tee Sees sicatinn pi cieness kaa seater agit wah See 33.

33. Stries TORS OF SPINY. (5.05 i50ssie ck ooo cated eens sone teape ee een dd.

ad, Ribs. fat-toppeds:...:..5.0.+.- 383. P. (Chlamys) magnolia.

da. Ribs subangular..., oo... ,002 380. P. ( Chlamys) perplanus.

Od, RIDS- TOWNES oosic. ois cdouate cs vw ates sinwen Sect ys cess eee TT}:

ttt. About 6 fine strize on top of each rib.

382. P. (Chlamys) jeffersonius.
ttt. About 3 coarse strize on top of each rib.

381. P. (Chlamys) madisontus.

33; Strise not SPINY sc. is.cssc0'nseneewessu's swede bape becouse ets en ee.
2b. GRIDS BUOUE (OMe het kas ovis nese 373. L. (Chlamys) stearnsit.
ee; Ribs -ADoOW- lA site scnos de 379. P. (Chlamys) wahtubbeanus.

C. INOb Tadially “SITIAte... inti iacaceesvandeescoses capunsacceneoude qsaaeen 44.

44. ‘Ribs ‘bifurcating, ... 2.07.24 sss: 376. P. (Chlamys) choctavensts.

A4u | Ribs simple. esis. didedssscesden, ddis-decdnbes Seassse cede ees saaannnnn

ff. Ribs increasing by implantation at front of shell.
378. P. (Chlamys) johnsont.

ff. Ribs not increasing by implantation........ ....cccseeereeeses 4f-
Ay. WRibs\25~30 ..hise.-. hades oe 377. L. (Chiamys) sreggt.
Afr FRIDS 1 LATS dese vine cad abv s'enc snone.e ble « bh 04 pet een

*, Shell } inch’high..375. P. ( Ch/amys) nebrateeae

PELECYPODA—PRIONODESMACEA. 497

*, Shell\s-speh high: si 2k anaes 365. P. texanus.

3. Ribs strongly unequal, 7. ¢., major and minor ribs,............ceeeeeseeeeeees d,
@. Radtally stvaste oa foscc. oti aia Gae eet a ou. vajails Micke ete dames Makai 55-
55. Ribs not prominent............ 374. P. (Chlamys) complexicosta.

BG RIBS Very Prominent; (inch sae yaa ckek mate tak os oeune dnucnas aoeedainns £e-

gg. Major ribs unequal.............. 386. P. (Chlamys) fucanus.

gg. Major ribs equal............. 385. P. (Chlamys) estrellanus.

DoS AVOL WAGUMAIG SUIGRE OP oe Gadd oh date Rte eek os ates ane Ye sedlaees 66,
66. Ribs not prominent............ 384. P. (Chlamys) marylandicus.
GPUS VED PONE yc ty t «fake nas d as vos van sep denete dp Lees’ ssitws ceaies hh.

hh. Ribs: bifurcating. issu cise ce..s vee 387. P. (Chlamys) healeyi.

FEUER PAINE GUINELO a case dares ens be cW ow nio hs Wee his Sata Ke nig vives Sneneve 5T.

5+. Anterior margin scalloped between the major ribs....**.
**, Shell very large, about 6 inches high,

366. P. roemert.
**_ Shell less than 2 inches high.

367. P. guinquecostatus.
5t. Anterior margin not scalloped.
380. P. (Chlamys) perplanus.

365. P. texanus Roemer. (Fig. 664.) Comanchic.
Surface of convex valve marked with 6
rounded ribs the spaces between occupied by
two lower though equal, rounded ribs.
Very abundant in the Washita, also present
in the Fredericksburg of Texas.

366. P. (Vola) roemeri Hill. (Fig. 665.)
Comanchic.
Large, thick, suboctahedral. Hinge line |
two thirds length of shell. Both ears and, Kb 4. Pato see
rest of shell marked with radiating coste, the anus. (After Shattuck. )
latter coarse and unequal.
Very abundant in the upper Washita (Buda) of Texas ; also in
Mexico.

367. P. (Neithea) quinquecostatus (Sowerby). (Fig. 666.)
Comanchic—Cretacic.
Right valve very convex, with incurved beak. Surface bearing
six strong, rounded, principal radiating ribs and two to four smaller
ones between ; ears also ribbed. Left valve flat.
Comanchic: (Washita), Texas, northern Mexico. Cretacic:
New Jersey (Merchantville—Navesink).

368. P. conradi (Whitfield). (Figs. 667-668.) Cretacic.
Surface of right valve crossed by crowded concentric folds

498 NOKTH AMERICAN INDEX FOSSILS.

Fic. 665. ecten ( Vola) roemeri, x 2. (After Shattuck. )

which do not extend across the ears, and are usually marked with
five or six radiating lines. Left valve usually smooth.
New Jersey (Merchantville—Navesink).

Fic. 666. ecten (Netthea) guinguecostatus. A large specimen. (After
Whitfield, Pal. N. J., I.)

369. P. simplicius Conrad. (Fig. 669.) Cretacic.
Differs from P. conradi in the smooth surface of its valves.

PELECY PODA—PRIONODESMACEA. 499

New Jersey (Red Bank and Tinton) ; also Alabama, Mississippi,
Arkansas, Texas.

370. P. quinquenarius Conrad. (Fig. 670.) Cretacic:

Fic. 667. Pecten conradi,; enlarged. (N. J. Pal., I.)
Fic. 668. Pecten conradi, enlargement of surface. (N. J. Pal., I.)

Right valve flat; left convex. Surface bearing 5 or 6 broad
ill-defined radiating ribs.
New Jersey (Wenonah and Navesink), Mississippi.

Fic. 669. Pecten simplicius; enlarged. (N. J. Pal., I.)

371. P. burlingtonensis Gabb. (Fig. 671.) Cretacic.
Right valve nearly flat; left valve depressed-convex. Surface
of each valve crossed by concentric bands continuous across the

Fic. 670. Pecten quinguenarius, a small right valve, (N. J. Pal., I.)
Fic. 671. Pecten burlingtonensis. (N. J. Pal., I.)

nearly equal ears, and marked with very fine radiating strie.
Large shells have a height of over two inches.
New Jersey (Merchantville-Wenonah), more common in former.

500 NORTH AMERICAN INDEX FOSSILS.

372. P. argillensis Conrad. (Fig. 672.) Cretacic,
Right valve depressed-convex ; left valve more convex. Sur-
face of both valves marked with fine, even, bifurcating, radiating
strie and close concentric lines which
project slightly as they cross the radii.
New Jersey (Merchantville—Navesink ;.
especially typical of the Woodbury),
Mississippi, Texas.
373. P. stearnsii Dall. (Fig. 675, ¢.)
Pliocenic.
Right valve with about 26 square ribs.
separated by narrower interspaces ; top:

Fic. 672. Pecten argillensis, of each rib marked by a median shallow
right valve. (After Whitfield,
Pal. N. J., I.)

groove and by one or two faint riblets.
on each side of the groove. Surface
crossed by concentric lamellz finer and twice as crowded on the
right valve as on the left. On the left valve the interspaces are
wider than the rounded ribs. Differs from P. healeyz in its radial
striation and more numerous ribs.
California.
XCVIII. Curamys Bolton.

A nearly equivalve Pecten, with small, unequal ears (posterior
the smaller) and deep byssal notch on whose edge is a well-
developed comb-like series of small teeth (ctenolium) in which
the byssal threads rested.» Surface of shell marked with radial
ribs or striz. Concentric lines often elevated into little tongue-
like extensions where they cross the radii. Triassic-Recent.

374. Pecten (Chlamys) complexicosta Gabb. (Fig. 673, g.)
Comanchic.
Surface marked with minute radiating striz and with 12 to 14
obscure radiating ribs with at times smaller ribs intercalated.
Very abundant in Knoxville of California.

375. P. (Chlamys) nebrascensis Meek and Hayden. _ Cretacic.

Small, suborbicular. Hinge line less than length of valve
below. Both ears separated from body of shell by rather angular
depressions. Surface of each valve marked with 12 to 15 large,
usually simple, angular, radiating ribs, separated by furrows of
about the same width as the ribs.

501

PELECYPODA—PRIONODESMACEA.

ST TAMARA ARRAN HHS

madt-

~

C

,

c

ht and left valves enlarged ;

7s, rig

Chlamys choctavens

?

a a,b

673
left valve,
ZUus,

FIG

“3
oe wi
=~
te
2
ae
ae
&
So
5 ane
S
x. ~~
S
Sw
s 3
a Sa
Cys
oc
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Sat
o &
sere
So
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os
et A
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=
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eee
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C. iefferson
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North Dakota, Wyom

.

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after

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.
>

Montanan
376. P. (Chlamys)

la

ibo

In

Montana, Assi
673,

ing,

choctavensis Aldrich.

)

b
Eocenic.

’

a

(Fig.

502 NORTH AMERICAN INDEX FOSSILS.

Surface imbricated when mature.
Maryland (Aquia and Nanjemoy), Alabama (Lignitic).

377. P. (Chlamys) greggi Harris. Eocenic.
Differs from P. choctavensis in its small number of ribs, and their
lack of bifurcation and imbrication.
Lignitic: Alabama, Georgia.
378. P. (Chlamys) johnsoni Clark. (Fig. 673, d@.) Eocenic.
Small. A few ribs implanted at front of shell.
Maryland, Mississippi.
379. P. (Chlamys) wahtubbeanus Dall. Eocenic.
Differs from P. johnsoni in its fewer ribs (about 14), each with 2
or 3 imbricated radial striz increasing by bifurcation.
Claibornian and Jacksonian: Alabama, Mississippi, Louisiana.

380. P. (Chlamys) perplanus Morton. Eocenic—Oligocenic.

Ribs subangular, about 23, with sloping sides and equally wide
interspaces ; an obsolescent thread on each side of the median
keel of each rib; all crossed by regularly spaced, low lamelle,
slightly produced over each rib. Byssal notch conspicuous but
not deep. Height 34 mm.; width 35 mm. (about twice the length
of the hinge).

Eocenic: Alabama (Jacksonian), Mississippi. Lower Oligo-
cenic: Florida (Vicksburgian).

381. P. (Chlamys) madisonius Say. (Fig. 673, ¢.) | Miocenic.
Whole surface covered with scaly striz ; ribs usually about 16,
rounded, with about 3 striz on top of each. Upper part of byssal
ear with few and coarse radiating striz. Byssal notch one third
length of ear.
New Jersey, Maryland, Virginia, North Carolina.

382. P. (Chlamys) jeffersonius Say. (Fig. 673, 7) | Miocenic.
Differs from P. madtsonius in its fewer ribs, with about 6 striz
on top of each, byssal ear covered with fine uniform and numerous
radiating striz, byssal notch barely one eighth the length of the
ear. As with many of the Pectens these two species grade into
each other.
Maryland, Virginia, North Carolina.
383. P. (Chlamys [Lyropecten]) magnolia Conrad. (Fig.
674, a.) Miocenic.

. | polices

PELECYPODA—PRIONODESMACEA. 503

Differs from P. 7effersonius in its flat-topped ribs, with about 10
radiating striae on each, the flat-bottomed interspaces, and the
byssal ear with a few obsolescent rays.

Very characteristic of the lower Miocenic (Vaqueros formation)
of California.

384. P. (Chlamys) marylandicus Wagner. (Fig. 673, ¢.)
Miocenic.
* Distinguished from P. madisonius by its want of elevated ribs ;
scales few.
Maryland (Calvert, Choptank), Virginia, North Carolina.

385. P. (Chlamys [Lyropecten]) estrellanus Conrad. (Fig.
674, 0.) | Miocenic.
Shell quite convex. Right valve with somewhat square ribs,

Fic. 674. a, Pecten (Lyropecten) magnolia, b, Pecten (Lyropecten) estrellanus.
Both & %. (After Arnold. )

separated by interspaces narrower than the ribs and in each of
which is a squarish riblet. Left valve with ribs more rounded,
narrower, and with wider interspaces whose riblets are inclined to
bifurcation. Both valves marked with radiating lines especially on
the anterior and posterior portions.

504 NORTH AMERICAN INDEX FOSSILS.

Throughout California.
386. P. (Chlamys) fucanus Dall. (Fig. 675, a, 6.) | Miocenic.
Surface reticulate. Right valve marked with more or less une-
qual, squarish, radially striate ribs, with at times smaller riblets

d

Fic. 675. a, 6, Pecten (Chlamys) fucanus; c, d, P. (Patinopecten) healeyi; e,
Pecten stearnsit. All < %. (After Arnold.) |
between. Left valve with radially striate ribs, the median one
stronger than the rest and usually with imbricating scales.
Washington, Alaska.
387. P. (Chlamys [Patinopecten]) healeyi Arnold. (Fig.
6075; .¢; 2.) Pliocenic.

PELECYPODA—PRIONODESMACEA. 555

Left valve marked with rounded ribs (slightly keeled at top) and
each of the wide interspaces marked with a smaller rib. Right
valve marked with squarish ribs, more or less bifurcating ; inter-
spaces narrow.

California, Lower California.

XCIX. CAMPTONECTES Agassiz.

A small, thin Pecten, nearly smooth, more or less inflated,
marked with fine, almost microscopic and more or less vermicular
groovings which radiate from the umbo and are deflected laterally
from a median line on each valve. (This so-called ‘“ Camptonectes
striation’’ is common to many recent /ectens both ribbed and
smooth.) Valves similarly sculptured. Posterior ear small,

Fic. 676. Camptonectes bellistriatus. (After Stanton. )

obliquely truncate; anterior much larger, in the right valve cut
by a deep byssal sinus. Jurassic—Recent.

388. Pecten (Camptonectes) bellistriatus Meek. (Fig. 676.)
Jurassic.
Shell very thin, slightly oblique to the hinge line, compressed.
Outline subcircular, slightly wider than high. Posterior ear very

506 NORTH AMERICAN INDEX FOSSILS.

short, about one half the size of the anterior. Anterior ear rather
large, separated from the body of the shell by an angular sinus
about half as deep as the length of the ear. Radiating striz very
fine and regular, increasing by intercalation. Concentric strie
fine and regular, closely arranged. Average height and breadth
each 1} inches. Differs from P. platessa in being proportionally
broader, with shorter ears and finer radiating striz.
Upper Jurassic: South Dakota, Wyoming, Utah.

389. P. (Camptonectes) extenuatus Meek and Hayden.
Jurassic.
Differs from P. dellistriatus in its smaller size, more convex
valves, more erect form, and height slightly greater than width.
Umbonal angle about 105°, height 3 inch ; breadth ;% inch.
Upper Jurassic: South Dakota (Sundance), Wyoming (Shirley),
Utah.

390. P. (Camptonectes) pertenuistriatus Hall and Whitfield.
Jurassic.
Differs from P. eatenuatus in its
more attenuated beak (umbonal angle
about 90°), flattened valves, finer:
striz, and more elongate form. Aver-
age height 1 inch; breadth 3 inch.
Montana, Wyoming. |
391. P. (Camptonectes) platessa’
White. (Fig. 677.) Cretacic.
Surface marked with fine radiating
striz which at the sides of the shell
recurve.
Coloradoan: Utah, Arizona.

right valve. (After Stanton. )

C. Entortium Meek.

A thin Pecten, with nearly equal ears which diverge at a sharp
angle above the beaks. Surface nearly smooth. Mississippic
Cretacic.

392. P. (Entolium) aviculatus (Swallow). (Fig. 678.)
Mississippic and Carbonic.

Surface marked with fine, close concentric striz and occasional

faint traces of radiating ones.

PELECYPODA—PRIONODESMACEA. 507

A characteristic Coal Measures species: Ohio to Oklahoma and
Wyoming ; also in Mississippic of Ohio and Arizona.
393. P. (Entolium) operculiformis Gabb. (Fig. 679.)
Comanchic—Cretacic.
Height greater than breadth. Sides of umbo straight, forming

Fic. 678. L£xntolium aviculatum, left valve. (Ind. Surv.)
Fic. 679. Entolium operculiformis. (Pal. Cal.)

almost a right angle. Surface smooth, polished.
Chico: California. Horsetown: California, Oregon.

CI. SyncycLonEMA Meek.

A small, nearly equivalve, vertically ovate Pecten. Hinge line
very short. Ears very small, the anterior the larger. Margins
closed all around, with no defined byssal sinus in either valve.
Surface only concentrically striated. Cretacic.

394. Pecten (Syncyclonema) rigidus Hall and Meek. Cretacic.

Hinge line about half the transverse diameter of the valves.
Posterior ear obliquely truncate, and hardly half as large as the
anterior which is subtrigonal, and slightly pointed. Right valve
marked with rather strong and regular concentric ridges and fur-
rows ; left valve smooth. Anterior margin with only a shallow,
rounded sinuosity under the ears which is nearly as deep in the
left valve as in theright. Average length 0.19 inch; height 0.23
inch. Differs from P. semplicius in the concentric ridges of the
right valve, the more regularly rounded outline of its narrower
valves, and in the different form of its ears.

Montanan : South Dakota, Montana, Wyoming.

CII. Amustum Schumacher.

A Fecten with raised radial riblets internally. Smooth exter-
nally or faintly striated. Valves of about equal convexity, large,

508 NORTH AMERICAN ANDEX FOSSILS.

rather flat. Ears subequal. Ctenolium absent; byssal notch in-
conspicuous or absent. Jurassic—Recent.

395. Pecten (Amusium) alabamensis Aldrich. Eocenic.
Very small. Surface of right valve nearly smooth; left with

a few radial threads crossed by distant concentric lines.
Midwayan: Alabama, Arkansas.

396. P. (Amusium) mortoni Ravenel. (Fig. 680.)
Miocenic—Recent.
Thin. Inside of valves marked with 18 to 24 radiating double
ribs.
Miocenic: Atlantic coast. Also Recent: Gulf of Mexico.

Fic. 680. Amustium mortoni, right valve, «3. (Md. Surv.)

CIHII. Prircatuta Lamarck.

Inequivalve, nearly equilateral, compressed. Surface bearing
coarse, radial, and often divaricate ribbing. Teeth long, shallow,
and crenulate, diverging at a sharp angle. Muscle scar single,
excentric. Shell sessile. Triassic-Recent.

397. P. dentonensis Cragin. Comanchic.

Rounded, subtriangular. Surface marked with numerous,
crenulated, and often spine-bearing ribs with intercalated shorter
and finer ones.

:

PELECYPODA—PRIONODESMACEA. 509

Very abundant in Washita of Texas.

CIV. Lima Bruguiere.

Shell inflated, marked with radial sculpture. Valves equal,
gaping anteriorly and sometimes posteriorly. Beaks pointed.
Hinge line straight, terminating in slightly unequal ears. Hinge
area of each valve triangular and with central resiliifer. Teeth
absent. Muscle impression single and large. Carbonic—Recent.
398. L. retifera Shumard. (Fig. 681.) Carbonic.

Surface marked with about 25 angular ribs about equalling the
spaces between, becoming obsolete on the umbo. Entire shell
covered with numerous, fine concentric striz.

Coal Measures: Ohio—Oklahoma.

399. L. wacoensis Roemer. Comanchic.

Differs from L. wtahensis in being slightly larger, more oblique
(obliquity about 45°), and more ventricose. Radiating ribs

Fic. 681. Lima retifera. (Kan. Pal., VI/II.)
Fic. 682. Lima utahensis, internal left mold of valve. (After Stanton. )

coarser, more angular, less uniform in size, and less regularly
arranged. The ribs frequently increase by implantation and
bifurcation.

Washita: Texas, Mexico; also Fredericksburg of Mexico.

400. L. utahensis Stanton. (Fig. 682.) Cretacic.
Moderately convex. Small.
Coloradoan: Utah, Mexico.

CV. Anomia Linné.

Thin, translucent, irregular or subcircular, attached by a calci-
fied byssus passing through a rounded sinus near the umbo of the
right valve. Right valve flattened, conforming to subjacent sur-
face, bearing a central adductor impression. Left valve larger,
convex, with four muscle scars on a central area, —three byssal
and one adductor. Teethabsent. Ligament more or less internal
and supplemented by a resilium. Jurassic—Recent.

510 NORTHMAMERICAN VN DEX (FOSSILS:

401. A. argentaria Morton. Cretacic.
Upper valve with submarginal apex; its surface covered with
irregular growth lines and at times with faint radiating strie.
Ripleyan of New Jersey (Cliffwood—Red Bank), Atlantic and
Gulf regions to Mexico.

402. A. propatoris White. (Fig. 683.) Cretacic.

Shell a little obliquely subovate. Beak
of upper valve depressed. Surface mark-
ed with rather coarse growth wrinkles
and a few radiating ones and by fine,
raised radiating striez. Differs from A.

ryphorhynchus in having a less promi-
FIG. 683. Axomia propator’s, EVIP Ly g p

Unhes. valve. shally ulameede ie and rounded umbo, in possessing

(After Stanton ) radial and concentric wrinkles and radial
striz.

Coloradoan: Colorado, Utah, New Mexico. Montanan: Utah.

403. A. gryphorhynchus Meek. Cretacic.

Elongate, convex. Beak elevated. Growth lines not strong.
Brackish water.

Montanan: Montana, Wyoming, Assiniboia, Mexico? Laramie:
Colorado, Wyoming.

CVI. Pracunopsis Morris and Lycett.

Free or attached, without foramen for passage of byssus.
Rounded, thin, with upper or right valve irregularly convex,
and lower or left valve flat or, when sessile,
conforming to the surface to which it was attach-
ed. Beaks very small, central. Surface marked
with irregular radiating lines and broad, faint
concentric wrinkles. Carbonic—Cretacic.

404. P. carbonaria Meek and Worthen. )Fig.
684.) Carbonic. '¢ wa ae
Car rta e
Concentric and radiating lines nearly obliter- i ete VI/I1.)
ated by an oblique series of ridges.
Ohio—Kansas.

CVII. Paranomia Conrad.

Irregular, inequivalve. Upper valve depressed-convex. Lower
valve flattened, often attached near the umbo to other objects,

PELECYPODA—PRIONODESMACEA. 511

very thin, probably perforate. Surface of both valves marked
with distant, rounded, radiating ribs. Cretacic.

405. P. scabra (Morton). (Fig. 685.) Cretacic.

Fic. 685. Paranomia scabra. (After Weller, Pal. N. J., IV.)

Ribs produced at irregular intervals into hollow spines.

Ripleyan of New Jersey (Merchantville-Navesink), Tennessee
and Gulf region.

CVIII. Mopitotorsis Hall.

Shell thin, obliquely elongate, very inequilateral, with small
anterior and large posterior end. Beaks nearly at anterior ends.
Valves crossed by an oblique depression extending backward from
the anterior portion of the umbo. Teeth absent, occasionally
represented by an obscure thickening and corresponding depres-
sion. Muscle impressions two ; anterior deep, and posterior large
and faint. Ligament chiefly external, deep seated.

Differs from Modiomorpha in the absence of teeth. Ordovicic
and Siluric.

406. M. faba (Conrad). Ordovicic.

Very small, with prominent umbonal ridge and sinus.

Trenton: New York, New Jersey, Wisconsin.

407. M. mytiloides Hall. (Fig. 686, 2.) Ordovicic.

Fic. 686. a, Modiolopsis concentrica; b, M. mytiloides. (Minn. Surv. )

Subcylindrical, marked by fine concentric lines interspersed with
stronger wrinkles. Junction of posterior margin with hinge line
almost angular.

512 NORFH AMERICAN INDEX FOSSILS.

Trenton: New York, Canada. Middle Galena: Wisconsin,
Minnesota.

408. M. concentrica Hall and Whitfield. (Fig. 686, a.)
Ordovicic.
Surface marked by regular concentric furrows which become
obsolete on the umbonal ridge.
Cincinnati: Ohio, Indiana, Kentucky.

Fic. 687. Modiolopsis modiolaris. (After Logan.)

409. M. modiolaris (Conrad). (Figs. 687 and 688.) Ordovicic.
Shell narrowed anteriorly, obliquely truncate posteriorly. Beak

not prominent. Surface crossed by concentric undulations.
Lorraine: New York, Pennsylvania. Cincinnati region.

Fic. 688. Zodiolopsis modiolaris, internal mold. (Pal. O., II.)

410. M. orthonota (Conrad). (Fig. 689.) Siluric.
Subquadrangular, surface marked with concentric lines only.
Medina: New York.

411. M. primigenia (Conrad). (Fig. 690.) Siluric.
Posterior end with ear. Surface marked with strong concentric

striz and very faint radiating ones.
Medina: New York.

PELECYPODA—PRIONODESMACEA. 513

412. M. dubia Hall. Siluric.
Differs from JZ. orthonota in that the umbos are nearly at the

anterior extremity and the concentric striz are at times replaced
by stronger wrinkles.
Manlius: New York.

Fic. 689. Modiolopsis orthonota. (Pal. N. Y., II.)
Fic. 690. Modiolopsis primigenia. (Pal. N. Y., II.)
CIX. Mopromorpna Hall.

_ Subovate, widest posteriorly, crossed obliquely from beak to
base by a more or less distinctly defined depression, constricting

Fic. 691. «@, Modiomorpha complanata, internal mold of left valve; 4, AZ. mytiloides ;
both 5<.% =: (Bal Ns¥ 25 ¥.)

the basal margin. Beaks small, compressed. Surface marked by
rugose or undulating concentric striz. Hinge with strong wedge-
shaped tooth in left valve and corresponding cavity in right. No

514 NORTH AMERICAN INDEX FOSSILS.

lateral teeth present. Ligament external, attached to thickened
margin of shell which is often longitudinally grooved for its recep-
tion. Pallial line simple. Devonic.
413. M. complanata Hall. (Fig. 691, a.) Devonic.
Large. Margins regularly rounded.
Onondaga: New York, Ohio.
414. M. mytiloides Hall. (Fig. 691, 4.) Devonic.
Above medium size, oblique. Basal margin nearly straight or

Fic. 692. a, Modiomorpha quadrula, 6, M. subalata,; c, M. alta; d, M. concentrica.
(Pal. N. Y., V.)
very slightly concave anterior to middle. Cardinal margin arcuate.
Anterior end narrowed and extended.
Hamilton : New York, Pennsylvania, Indiana ?

415. M. alta Hall. (Fig. 692, c.) Devonic.

PELECYPODA—PRIONODESMACEA. S18

Differs from JZ, mytiloides in its greater proportional height and
broader and less extended anterior end.
Hamilton : New York, Indiana, Falls of Ohio.

416. M. concentrica Hall. (Figs. 692, d; 694, @.) Devonic.
Of medium size. Distinguished by its strong and regular striz.
Differs also from JZ. mytiloides in its smaller size and more promi-
nent umbos ; from JZ. complanata in its more nearly straight base ;
from JZ. a/ta in its more elongate form.
Hamilton: New York and Maryland—Indiana and Wisconsin.

417. M. subalata Hall. (Fig. 692, 4:) _Devonic,

Of medium size or smaller. Distinguished by its more nearly
parallel cardinal and basal margins, angular umbonal ridge, and
the obsolescence of the striz on the umbonal region.

Hamilton: New York, Pennsylvania; also in Marcellus and
Ithaca of New York.

417a. M. subalata var. chemungensis Hall. Devonic.
Differs from the species in being longer in proportion to the
height, cardinal line less oblique, its posterior extremity usually

Fic. 693. Modiolodon oviformis. (Ohio, VII.)

more rounded, umbonal slope more arcuate, and striz are filiform,
sharper and more regular.
Characteristic of Portage of New York, Pennsylvania.

418. M. quadrula Hall. (Fig. 692, a.) Devonic.

Small, quadrangular, with straight umbonal ridge.
Chemung: New York.

516 NORTH AMERICAN INDEX FOSSILS.

CX. Mopiotopon Ulrich.

Modioliform, ovate shells, differing from Modolopsis and Modio-
morpha in the possession of one to three oblique cardinal teeth in
each valve. Hinge much like that of Ischyrodonta. Ordovicic.
419. M. oviformis Ulrich. (Figs. 693; 694, a.) Ordovicic.

Surface marked with a few faint concentric striez. Differs from

Cc

. b

Fic, 694. a, Modiolodon oviformis, hinge of left valve; 4, c, WZ. patulus, small
shell and internal mold of large one ; ¢, Modiomorpha concentrica, hinge‘of left valve.
(Minn. Surv. )

Modiolopsis modtolaris in its cardinal teeth, more oval shape, and
rounded instead of sinuate basal margin. Type of genus.
Basal Trenton of Kentucky and Tennessee.
420. M. patulus Ulrich. (Fig. 694, 4, c.) Ordovicic.
Anterior end very short, in the internal mold occupied almost
entirely by the elevated anterior muscle scar. Wider, more erect,
and more uniformly convex than JZ. oviformis.
Middle Galena: Minnesota, lowa. Trenton: Kentucky.

CXI. Corpomya Ulrich.

Inequilateral. Hinge and basal margins subparallel. Broad
mesial furrow distinct. Beneath beak of right valve is a tooth-
like prominence which fits into a corresponding depression in the
opposite valve, differing thus from d/odtolodon ; beneath this de-
pression is a strong projecting process. Ordovicic.

421. C. constricta Ulrich. (Fig. 695, a, 0.) Ordovicic.

Valves very convex.on umbonal ridge. Beaks strongly in-
curved. Surface marked with strong concentric growth lines.
Type of genus.

Upper Trenton of Kentucky.

.PELECYPODA—PRIONODESMACEA. 517

CXII. WuHitkAvEsia Ulrich.

Very similar to M/odtolopsis but differs in its thinner hinge plate
and shell, in the convex basal outline and absence of a mesial fur-
row. From Orthodesma it also differs in these last two character-
istics as well as in its tightly closing instead of gaping valves.
Ordovicic. |
422. W. modioliformis Meek and Worthen. (Fig. 695, @.)

Ordovicic.

Shell obliquely oval, marked with rather strong concentric

wrinkles especially anterior to the umbo.

Fic. 695. a, 4, Colpomya constricta, right and left valves; c, Whiteavesia cincinnat-
zensis, right valve ; d, W. modioliformis, left internal mold. (Minn, Surv.)

Stones River of Wisconsin, Minnesota ?

423. W. cincinnatiensis Hall and Whitfield. (Fig. 695, c.)
Ordovicic.
Surface marked with numerous, irregular concentric and faint
tadiating lines. Type of genus.
Eden of Ohio, etc.

CXIII. Eurymya Ulrich.

Somewhat triangular, with broad and wing-like posterior, and
greatly narrowed anterior end. Base oblique. Hinge line straight.
Beaks small, near anterior extremity. Hinge with obscure cardi-
nal tooth in left valve and corresponding depression in right, and
with broad and longitudinally striated ligament area posterior to
the beaks. Muscle impressions as in MWodtolopsis. Differs from
Modiolopsis and Modiomorpha in the wing-like posterior extremity

518 NORTH. AMERICAN INDEX FOSSILS.

and in the presence of a striated ligament area. It also lacks the
mesial depression of Modiolopsis. Ordovicic.
424. E. plana Hall. (Fig. 696, a, 0.) Ordovicic.

Small, triangular, marked with strong concentric growth lines.
Type of genus.

Stones River of Minnesota, and Wisconsin (Lower Blue lime-
stone).

CXIV. ARISTERELLA Ulrich.

Subovate, small, moderately convex, nearly smooth, inequivalve.
Left valve the smaller. No mesial furrow present. Hinge appar-
ently very thin and without teeth. Muscle and pallial impressions.

Fic. 696. a, 6, Eurymya plana, interior of left valve and its hinge enlarged; c—e,.
Aristerella nitidula, natural size and enlarged. (Minn. Survey. )

as in Whiteavesia. Differs from Eurymya and Whiteavesia in its.
unequal valves. Ordovicic.
425. A. nitidula Ulrich. (Fig. 696, c, d, ¢.) Ordovicic.
Minute; surface nearly smooth. Type of genus.
Black River: Minnesota.

CXV. GonropHora Phillips.

Equivalve, very inequilateral, obliquely truncate posteriorly,
rounded anteriorly. Cardinal line straight. Beaks small and
closely incurved. Umbo prominent. A _ strong angular ridge
extends from the umbo to the posterior margin and a broad, un-

Fic. 697. Goniophora dubia, right valve enlarged and natural size. Cardinal view
of a complete specimen, natural size. (After Whitfield. )

defined sinus from umbo to base. Surface marked by concentric
strie. Ligament external. Like Modzomorpha in internal charac-

Ee Oe ee

PELECY PODA—PRIONODESMACEA. 519

ters but differing externally in form and in the strong angular
umbonal ridge. Siluric-Carbonic.

426. G. dubia Hall. (Fig. 697.) Siluric.
Small, elongate; umbonal ridge subangular, a broad shallow
sinus below it.
Lower Monroan of Michigan and Ohio. Manlius of New York.
427. G. perangulata Phillips. (Fig. 698.) Devonic.

Fic. 698. Goniophora perangulata. (Pal. N. Y., V.)

Umbo acutely angular. Umbonal ridge elevated, sharp, curv-
ing slightly to the posterior basal extremity. Shell beneath the
umbo concave.

New York (Schoharie Grit), Nevada.

428. G. modiomorphoides Grabau. Devonic.
Distinguished from other species by its very short anterior end
scarcely extending beyond the beaks.
- Middle Hamilton (Encrinal limestone): New York.

429. G. hamiltonensis Hall. (Fig. 699, c.) Devonic.
Length more than twice the height. Margin but slightly curv-
ing. Umbonal ridge strongly angular and prominent.
Hamilton: New York, Pennsylvania.
430. G. truncata Hall. (Fig. 699, 2.) Devonic.
Basal margin rounded anteriorly and slightly sinuate near the
middle. Cardinal line short. Concentric striz on the surface
between the umbonal ridge and the sinus crossed by radiating
striz.
Hamilton: New York.
431. G. ida Hall. (Fig. 699, a.) Devonic.
Distinguished by its narrowly elliptical form, the regularly
curving basal margin; the hinge line is comparatively shorter
than in any other of the Hamilton species except G. truncata.
Hamilton: New York.

432. G. carinata Hall. (Fig. 699, d@.) Devonic.

520 NORTH: AMERICAN INDEX FOSSILS:

Fic. 699. a, Goniophora ida, b, G. truncata; c, G. hamiltonensts ; ad, G. carinata ;
e, G. chemungensis, Allright valves. (N. Y. Surv.)

Surface marked by fine undulating concentric striz which are
aggregated into folds upon the lower end and anterior portions.

Anterior end long.
Hamilton: New York.
433. G. chemungensis Hall. (Fig. 699, ¢.) Devonic.
Distinguished by its elongate form, short anterior end and fine
concentric striae which form folds anteriorly.
Chemung: New York.

CXVI. Myrirus Linné.

Equivalve, very inequilateral, elongated, usually thin, with
terminal pointed beaks. Valves wider and rounded below, gap-
ing a little for the byssus, usually smooth. A conspicuous epi-

PELECYPODA—PRIONODESMACEA. 521

dermis and a thin nacreous layer present. Hinge with a few
small teeth under the beaks or without teeth. Pallial line simple.
Triassic—Recent.

434. M. conradinus d’Orbigny. Miocenic.

Fic. 700. Mytilus conradinus, right valve, & %. (Md. Survey.)

Shell very convex. Beak heavy, solid. Hinge with slightly
prominent teeth.
New Jersey—Texas.

CXVII. Mopiora Lamarck.
Like Mytilus but umbos obtuse and anterior though not ter-
minal. Valves inflated in front. Epidermis rather hairy. De-
vonic—Recent.

435. M. major Gabb. (Fig. 701.) Comanchic.

Fic. 701. Modiola major, X %. (Pal. Cal., II.)

Shell very large and thick.
Very abundant throughout the Shasta of California.

436. M. multilinigera Meek. (Fig. 703, a.)

Cretacic.
Surface covered with fine radiating and con-_
centric lines. Fic, 702. Modiola
Coloradoan: Kansas—Utah. saffordi, left valve.
437. M. julia Lea. Cretacic, ‘After Haris.)

A rounded umbonal ridge passes backward from the beak to
the posterior basal margin. Surface markings are concentric

522 NORTH AMERICAN INDEX FOSSILS.

growth lines, which are strongest on the posterior umbonal slope.
Ripleyan of New Jersey (Merchantville, Woodbury), Texas.

438. M. saffordi Gabb. (Fig.
FOR.) Eocenic.
Umbo and umbonal ridge

more prominent than in JZ.

alabamaénsts.

Midway: Tennessee, Texas.’

EERO,
EX
CESSES GSES
IES SIS
oS iL = SSSA
1 TSS
SS SN

:
FESS
ah, OF a 0,
nena
ttt
Zee one
Led

439. M. alabamaensis Ald-
rich. (Fig. 703, 0.)

Serer Le? Li Eocenic.
y Hinge margin _ slightly
curved, ascending. Shell

Fic. 703. a, Modiola (Brachydontes) strongly arcuate. Umbones
multilinigera, left valve. (After Stanton. ) prominent, curved.
b, M. alabamaénsis, right valve; with indi-

cator of size. (Md. Survey.) Pamunkey : Maryland, Vir-

ginia.
CXVIII. CrRENELLA Brown.

Shell small, ovoid. Beaks more or less incurved. Surface with
a thin epidermis and a fine radial striation. Cretacic-Recent.

440. C. serica Conrad. Cretacic.
Radiating strize seen under a lens; concentric lines large, fine
and regular. Anterior slope from umbo abrupt.
New Jersey (Marshalltown and Red Bank), Gulf region.

441. C. elegantula Meek and Hayden. Cretacic.
Differs from C. sertca in its much larger size, its proportionately
broader form, and in the absence of conspicuous concentric
markings.
Montanan: Nebraska—Montana; Tinton of New Jersey.

Order 2, ANOMALODESMACEA.
CXIX. PLeEuromya Agassiz.

Slightly inequivalve. Posterior side the longer, somewhat
gaping. Hinge margin with a thin, horizontal lamina in each
valve, the left inferior; the margin with a feeble notch behind the
lamina. Individuals of the same species quite variable. Triassic—
Comanchic.

PELECYPODA—ANOMALODESMACEA. 523

442. P. subcompressa Meek. (Fig. 704.) Jurassic.
Surface crossed by concentric ridges. Posterior end sloping.
Widely distributed in the Jurassic from the plains to the Pacific

coast.

Fic. 704. Pleuromya subcompressa, right and cardinal views. (After Logan. )

443. P. inconstans Castillo and Aguilera. (Fig. 705.) Jurassic.
A broad, shallow sinus usually present in the anterior umbonal
region. Posterior end high.
Texas, Mexico. One of the most widely distributed fossils of
the Malone formation.

Fic. 705. Pleuromya inconstans, (After Cragin.)

CXX. ALLoRISMA King.

Equivalve, inequilateral, elongate, thin, arcuate. Anterior side
short; posterior long and gaping. Beaks anterior, depressed.
Sculpture concentric, strongest medially. Hinge without teeth.
Ligament external. Cardinal margin inflected, forming a lanceo-
late depression along its border behind the beaks. Posterior ad-
ductor scar large. Pallial line sinuate. Carbonic and Permic.

444. A. geinitzi Meek. Carbonic.
Small. Umbonal slopes carinated from the beaks posteriorly.
Surface marked with fine, radiating and concentric lines.
Coal Measures: Illinois, Kansas.

524 NORTH AMERICAN INDEX FOSSILS.

445. A.costatum Meek and Worthen. (Fig. 706.) Carbonic.
Radiating coste present on posterior slope ; concentric lamelle
elevated.
Coal Measures: Illinois, Ohio, Kansas, Missouri, Iowa.

Fic. 706. Adlorisma costatum. (Kan. Pal. Vi.
Fic. 707. <Adlorisma granosum. (Kan. Pal., VI/II.)

446. A. granosum Shumard. (Fig. 707.) Carbonic and Permic.

Beaks very prominent, incurved; a slight sinuosity sometimes
present in the base.
Upper Coal Measures: Kansas, Missouri. Permic of Kansas.

, 3 " a
eee ee are
Patera Sy

Fic. 708. Allorisma terminale. (Kan. Pal., VI/1I.)

447. A. terminale Hall. (A. subcuneata Meek and Hayden.)
(Fig. 708.) Carbonic and Permic.
Large. Dorsal and basal margins subparallel.

Coal Measures of United States from Pennsylvania to Utah.

Permic of Kansas.

CXXI. SpuHenotus Hall. ,
Entire shell almost cylindrical in shape. Posterior end usually ,
obliquely truncate. Beaks very near anterior end, hinge line long

:
:

PELECYPODA—ANOMALODESMACEA. 526

and straight. Valves marked with a well-defined umbonal ridge
and a broad sinus which often constricts the basal margin. Con-
centric growth striz present. Hinge narrow, with two short teeth
beneath the beak and with one or two slender lateral teeth. Liga-
ment external and contained in a slender groove, along the hinge
line. Muscle impressions two. Pallial line simple. Differs from
Sanguinolites and Allorisma in the umbonal and posterior cardinal
ridges, its trapezoidal form, in the cincture crossing the valves, and
in the characters of the hinge. Devonic and Mississippic.

Fic. 709. Sphenotus truncatus. (Pal. N. Y., V.)
Fic. 710. Sphenotus cuneatus. (Pal. N. Y.)

448. S. truncatus. (Fig. 709.) Devonic.
Small truncate posterior end, strong angular umbonal ridge.
Ithaca of New York, Pennsylvania, etc.

449. S. cuneatus. (Fig. 710.) Devonic.
Larger than preceding, with more pointed anterior and more

rounded posterior end ; a second pronounced ridge above umbonal

ridge.
Ithaca of New York, etc.
450. S. contractus Hall. (Fig. 711, c.) Devonic.

Fic. 711. a@, 6, Sphenotus eolus; c, £ contractus, right valve. (N. Y. Surv.)

526 NORTH AMERICAN INDEX FOSSILS.

Posterior extremity oblique, somewhat doubly truncate. Sinus
without distinct limitation, merely flattenening the shell above and
slightly depressing it below.

Chemung Group: New York, Pennsylvania.

451. S. zolus Hall. (Fig. 711, a, 0.) Mississippic.
Distinguished from S. contractus by its larger size, more rounded

base, simply truncated posterior end, and lamellose growth lines.
Waverly : Ohio.
CXXII. Ravytimya Ulrich.

Shell very thin, elongate, gaping slightly at both ends. Hinge
and basal margin subparallel. Beaks prominent. Mesial furrow
wide. Ligament external. Hinge apparently without teeth.
Muscle scars very faint. Surface covered with concentric folds,

Fic. 712. _Rhytimya radiata. (Ohio Survey, VII.)
Fic. 713. Rhytimya producta. (Ohio, VII.)
strongest on anterior end, crossed on posterior half by radiating
rows of small granules. Ordovicic.
452. R. radiata Ulrich. (Fig. 712.) Ordovicic.
Mesial furrow very slightly developed.
Lower beds of Cincinnati Group of Ohio, Kentucky.
453. R. producta Ulrich. (Fig. 713.) Ordovicic.
Surface crossed by about ten sharp concentric folds anterior to
the beaks, becoming less sharp over the rest of the shell. Type
of genus.
Middle beds of Cincinnati Group of Ohio, Kentucky.

Fic. 714. Rhytimya mickleboroughi. (Ohio, VII.)

454. R. mickleboroughi Whitfield. (Fig. 714.) Ordovicic.
Shell very elongate, anterior end acute.
Middle beds of Cincinnati Group of Ohio.

PELECYPODA—ANOMALODESMACEA. 527

CXXIII. EnNnpopgesma Ulrich.

Shell very thin, equivalve, convex, elongate. Hinge and basal
margins subparallel. Mesial depression deep. Umbones com-
pressed, elevated. Hinge thin, apparently without teeth. A flat-
tened area (lunule) present in front of beaks. Surface covered
with concentric lines. Muscle scars very faint. Ordovicic.

455. E. orthonotum Meek and Worthen. (Fig. 715, 4, c.)

Ordovicic.
Umbonal slope subangular dorsally.
Stones River limestone of Illinois and Minnesota.
456. E. gesneri Billings. (Fig. 715, a.) Ordovicic.

b
Fic. 715. «a, Endodesma gesneri, right valve; 5, c, E. orthonotum,; d, e, E.
cuneatum, all internal molds. (Minn. Surv.)

Differs from £. orthonotum in its subangular anterior extremity,
its more rounded upper posterior edge, and its comparatively
shorter length.

Black River and Trenton of Ontario.

457. E.cuneatum Ulrich. (Fig. 715, d, ¢.) Ordovicic,

Surface of internal mold bearing a few obscure concentric folds.
Type of genus.

Middle Galena of Minnesota.

CXXIV. PHOLADELLA Hall.

Transversely elongate, with truncate posterior end and rounded
or obliquely truncate anterior end. Beaks anterior to middle and
prominent. Umbonal slope prominent. Surface marked with fine

528 NORTH AMERICAN INDEX FOSSILS.

concentric striz, often becoming strong undulations, and, on the
body of the shell, with distinct radii which are absent from the
anterior end and cardinal slope. Ligament external. Devonic.

458. P. radiata (Conrad). (Fig. 716.) Devonic.

Fic. 716. Pholadella radiata ; a, b, right valves; c, d, left valves.
(Pal. N. Y., V.)

Basal margin slightly sinuous, owing to the depression extend-
ing from beak to base.

Hamilton: New York, Pennsylvania, Maryland. Ithaca: Penn-
sylvania.

CXXV. Cimiraria Hall.

Very elongate, with anterior and strongly incurved beaks,
short and rounded anterior end and long and truncate posterior.
Umbonal slope well defined. Surface crossed by strong concen-
tric growth lines and marked by very fine radial strize and by a
depression extending somewhat posteriorly from the beaks to the
base. Lunule present. Ligament external. Hinge without teeth.
Devonic.

459. C. corrugata (Conrad). (Fig. 717, d.) Devonic.

Posterior cardinal slope comparatively wide, marked by one or
several radial folds. Body of shell marked by concentric undu-
lations.

Hamilton: New York.

460. C. recurva (Conrad). (Fig. 717, a, 0.) Devonic.

Differs from C. corrugata in its more curving outline and more
rounded posterior extremity. Type of genus.

Hamilton: New York, Pennsylvania.

461. C. angulata Hall. (Fig. 717, c.) Devonic.

Umbonal ridge strong and angular. Concentric strie regular
and covering the whole shell.

Chemung: New York.

CXXVI. PHOLADOMYA Sowerby.

Shell thin, translucent, subovate, ventricose, equivalve, gaping
posteriorly and sometimes anteriorly. Anterior side short, rounded.

.

PELECYPODA—ANOMALODESMACEA. 529

Fic. 717. a, 6, Cimttaria recurva, right and cardinal views; c, C. angulata, left
valve ; @, C. corrugata. (N. Y. Surv.)

Surface marked with radiating ribs (feeble in the posterior dorsal
region), crossed by concentric striza. Umbos prominent. Liga-
ment external. Hinge without teeth or with an obscure thicken-
ing. Adductor scars feeble. Pallial sinusdeep. Jurassic—Recent.

462. P. sancti-sabe Roemer. (Fig. 718.) Comanchic.
Beaks prominent ; ribs noded by concentric ridges.
Fredericksburg to Denison: Texas, Oklahoma.

463. P. papyracea Meek and Hayden. Cretacic.
Beaks depressed, small, incurved. Surface of each valve marked

530 NORTH AMERICAN INDEX FOSSILS.

with 10 to 12 radiating ribs and with very regular, sharply defined
and closely arranged concentric ridges. In form quite similar to
P. marylandica but it is much smaller (average length 1.2 inches ;
height 0.8 inch; convexity 0.6 inch),
and the surface markings are more
prominent.
Benton: Kansas, Montana.
464. P. occidentalis Morton.
Cretacic.
Surface marked with 25 to 30 radi-

ating, somewhat irregular, and wavy

Fic. 718. Pholadomya sancti- ribs, closest together on middle of
shell.

Ripleyan of New Jersey (Cliffwood—
Woodbury) ; Gulf region, Arkansas.

sabe. (After Meek, Mex. Bd.
Surv. )

Eocenic.

Fic. 719. Pholadomya marylandica, left valve. (Md. Surv. )

Length about 3 inches, very fragile.
Aquia: Maryland.

CXXVII. Puenacomya Dall.
Equivalve, thin, marked with feeble radii. Anterior end more
or less expanded and truncate. Posterior end attenuate and
smoother. Eocenic.

PELECYPODA—ANOMALODESMACEA. 531

466. P. petrosa (Conrad). (Fig. 720.) Eocenic.
Ventricose anteriorly. Radii sharp, numerous,
Aquia of Maryland.

Fic. 720. Phenacomya petrosa, \eft and cardinal views, x 2. (Md. Surv. )

CXXVIII. Anatimya Conrad.

Oblong. Anterior side with concentric sculpture ; posterior
with concentric and radiating ribs. Cretacic.

4607. A. anteradiata Conrad. (Fig. 721.) Cretacic.

FIG. 721. Anatimya anteradiata. (After Weller, Pal. N. J., IV.)

Beaks scarcely elevated above hinge line, pointing posteriorly.
Valves depressed-convex. Margins subparallel.
Ripleyan of New Jersey (Woodbury, Wenonah), Mississippi.

CXXIX. LiopistHa Meek. (Includes Cymetta Meek.)

Equivalve, oval, thin, inflated. Valves gaping and compressed
posteriorly, concentrically or radially striated. Beaks prominent,
incurved. Hinge inflected along its entire length. Cardinal teeth
two, projecting directly outward from beneath the beaks. Liga-
ment sunken, partly external. Cretacic.

The typical Lzopistha has the shell ornamented principally by
strong radial ribs, while in the subgenus Cyme//a the chief sculp-
ture is the large, strong, regular concentric undulations which are
crossed by only a few radiating markings.

532 NORTH AMERICAN INDEX FOSSILS.

468. L. meeki White. (Fig. 722.) Cretacic.
Surface marked with radiating striz and fine concentric growth
lines.
Coloradoan : Utah.

Fic. 722. Liopistha meeki, cardinal and right views. (After Stanton.)

469. L. (Cymella) bella (Conrad). (Fig. 723.) Cretacic.
Radiating ribs strongest on middle of valve.
Ripleyan of New Jersey (Cliffwood—
Wenonah), Virginia and Gulf region.

470. L. protexta(Conrad). Cretacic.
A concave area at posterior extrem-
ity nearly or wholly destitute of ribs.
Ripleyan of New Jersey (Wenonah—
Tinton), Gulf region.
: 471. L. (Cymella) undata Meek and
Fic. 723. Cymella bella. (N. Hayden. Cretacic.
J. Pal., I.) 7 Radii finer than in LZ. della. Type
of subgenus Cymella.
Montanan : throughout the Rocky Mountain region ; Wenonah
of New Jersey.

CXXX. CuspipArRrA Meek.

Hinge without teeth, but with a small, internal, posteriorly in-
clined resilifer in each valve and an elongated ridge behind it.
Ligament subinternal, anterior to the beaks or obsolete. Pallial
line simple. Surface concentrically sculptured. Jurassic—Recent.
472. C. ventricosa Meek and Hayden. Cretacic.

Posterior side of shell the longer, usually abruptly contracted.
Surface marked with concentric striz.

Ripleyan of New Jersey (Wenonah-Tinton), Montanan of South
Dakota and Montana.

473. C. moreauensis Meek and Hayden. (eera moreauensis.)
Cretacic.

PELECYPODA—TELEODESMACEA. 533

Distinguished from C. ventricosa by its regular, concentric ribs,
instead of mere striz. |
Montanan: South Dakota, Montana, Assiniboia.

Order 3: TEREODESMACEA,
CXXXI. PLeuRopHoRuS King.

Inequilateral, elongated, rectangular, with beaks nearly terminal.
Two cardinal and one posterior lateral tooth present in each valve.
- Anterior muscle scar deep, bounded posteriorly by a ridge. Pallial
line simple. Devonic—Triassic.

474. P. tropidophorus Meek. (Fig. 724.) Carbonic.

Posterior slope doubly angular with two ridges that pass ob-
liquely backward from the beaks. Surface marked with strong
concentric growth lines.

Coal Measures of Ohio, Missouri.

475. P. oblongus Meek. Carbonic.

Somewhat similar to P. tropidophorus but differs in. the small
size, with length never exceeding .5 inch, in the wider posterior

Fic. 724. Pleurophorus tropidophorus, right valve. (Kan, Pal., VI/ II.)
Fic. 725. Pleurophorus subcostatus, left internal mold. (Kans. Pal., VI.)
Fic. 726. Pleurophorus albequus, right valve. (After Beede. )

end, producing a slight divergence of the basal and cardinal mar-
gins, in lacking the doubly angular slope and in the finer concen-
tric striz.
Illinois, Missouri, Arkansas, Nebraska.
476. P. subcostatus Meek and Worthen. (Fig. 725.)
Carbonic.
Surface covered with fine growth lines and with three or four
radii extending from the beak to the posterior margin.
Ohio—Colorado. |
477. P. occidentalis Meek and Hayden. Carbonic and Permic.
Much like P. oblongus in size but with narrowing posterior end
instead of the vertically truncate end of P. obd/ongus and with radi-
ating ridges extending from the beak to the posterior margin.
Carbonic: Nebraska, Colorado. Permic: Kansas, Nebraska,
Texas, New Mexico.

534 NORTH AMERICAN INDEX FOSSILS.

478. P.? albequu'’s Beede. (Fig. 726.) Permic.

Surface marked with two to six faint ribs extending from the
beak to the posterior margin ; growth lines strongest on anterior
portion of shell. Differs from P. occidentalis in being larger, and
in having an arcuate hinge; from P. od/ongus in being proportion-
ally much longer and in possessing radiating ridges.

Very abundant in the upper Permic of Oklahoma (Whitehorse)
and Texas (Quartermaster).

CXXXII. Cypricarpeia Hall. (Microdon Hall.)

Equivalve, inequilateral, subquadrate, with straight or nearly
straight hinge line. Anterior end narrow and rounded. Posterior
end longer, broad, and truncate. Beaks small, appressed. Um-
bonal ridge more or less defined, extending backward from the
beaks. Surface marked with more or less lamellose concentric
strie. Hinge with a triangular tooth in each valve and corre-
sponding sockets. There is also in the right valve a longer trian-
gular fold or lateral tooth. Ligament external, extending nearly
or quite the whole length of the hinge line. Pallial line simple.
Devonic and Mississippic.

479. C. tenuistriata Hall: (Fig. 727, a, 4.) Devonic.

Fic. 727. a, 6, Cypricardella tenuistriata, \eft valve, and cardinal ‘view of small
specimen; c, a, C. bellistriata. (Pal. N. Y., V.)

Larger than C. del/istriata with less angular umbonal slope and
less well-defined striz.
Hamilton: New York.

PELECYPODA—TELEODESMACEA. 535

480. C. gregaria Hall. Devonic.
Smaller than C. delfstriata, with more curving posterior end
and finer striz.
Hamilton—Chemung: New York, Pennsylvania.

481. C. bellistriata Conrad. (Fig. 727, c, a.)
Devonic—Mississippic.
Distinguished by its strong surface striz.
Marcellus-Chemung : northern Appalachian region ; abundant
in Hamilton of New York, Pennsylvania, Maryland, Lower Wav-
erly of Ohio.

482. C. oblonga Hall. (Fig. 728.) Mississippic.

Fic. 728. Cypricardella oblonga. a, cardinal view ; 4, internal mold of right valve,
showing muscular impressions ; ¢, hinge of right valve enlarged; d, ¢, left and right
valves. (After Whitfield. )

Base subparallel to hinge line. Posterior margin obliquely
truncate.
Indiana (St. Louis), Kentucky (St. Genevieve).

CXX XIII. Cypricarpinia Hall.

Inequivalve, with more convex right valve, somewhat rhomboid
or trapezoidal. Anterior end short and rounded ; posterior wider
and obliquely truncate. Beaks nearly at anterior extremitiy.
Umbonal slope prominent. Surface marked by concentric lamel-
lose ridges with intermediate fine growth striz and in some species
radial striz. Two to three cardinal teeth present. Ligament ex-
ternal. Pallial line simple. Shell thicker than in Modiolopsis
and concentric striz stronger. Siluric—Mississippi.

483. C. arata Hall. Siluric.
Surface crossed by strong concentric lamellose ridges.
Niagaran: Indiana, Wisconsin, Oklahoma. Also Siluric of

Alaska.

484. C. lamellosa Hall. Devonic.
Gibbous, with short anterior and long posterior extremities.

536 NORTH AMERICAN INDEX FOSSILS.

Helderbergian : New York.
485. C. indenta Conrad. (Fig. 729, c.) Devonic.
Length more than one third greater than height. Hinge line

straight and oblique.
Onondaga: New York, Falls of the Ohio, Ontario. Abundant

Fic. 729. a, 6, Cypricardinia consimilis, right and cardinal views; ¢, C.
indenta. (N. Y. Surv.)

in Hamilton of New York, Pennsylvania, Virginia. . Also in Lower

Devonic of Nevada.

486. C. consimilis Hall. (Fig. 729, a, 0.) Mississippic.
More elongate than C. zudenta, with comparatively,

narrower posterior end and less sinuate basal margin.

Waverlyan: Pennsylvania, Ohio.

FIG. 730.

Cypricardi- 487. C, carbonaria Meek. (Fig. 730.) Carbonic.
nia carbona~ Small. Surface marked with 15 to 20 flattened,
ria. (Kan. Tene SeneM Ys $a
Pal., VI/1I.) Subimbricating concentric ridges.

Ohio, Kansas, Missouri, Colorado.

CXXXIV. AsTARTELLA Hall.

Shell thick, smooth or concentrically furrowed. Lunule im-
pressed. Two cardinal teeth present in each valve ; the posterior
tooth in the right valve has a longitudinal pit on the summit.
Ligament external. Carbonic.

488. A. vera Hall. (Fig. 731.) Carbonic.

eel

Fic. 731. <Astartella vera. (Kan. Pal., VI/II.)
Fic. 732. Astartella newberryt. (Pal. Ohio, II.)
Surface marked with strong concentric furrows separated by
sharp angular ridges.
Coal Measures : Ohio—Oklahoma.
489. A. newberryi Meek. (Fig. 732.) Carbonic.

PELECYPODA—TELEODESMACEA. 537

Differs from A. vera in the less prominent and more nearly cen-

tral beaks and the more numerous and regular concentric ridges.
Coal Measures: Ohio, Arkansas, Oklahoma.

CXXXV. Arctica Schumacher. (Cyprina Lamarck.)

Orbicular or oval, inflated, with thick epidermis. Beaks prom-
inent, incurved. Lunule absent. Three cardinal and one ridge-
like posterior lateral in each valve; the middle cardinal of left
valve the largest. Surface marked with concentric striz. Margins
of valves smooth. Ligament external and prominent. Pallial line
simple. Jurassic—Recent.

490. A. coteroi Castillo and Aguilera. (Fig. 733.) Jurassic.

b rai

Fic. 733. Arctica coteroi, left and front views of internal mold. (After Cragin. )

Surface of shell when preserved marked with concentric growth
lines and occasional concentric grooves. Length less than 2
inches.

Upper Jurassic of Texas (Malone) and central Mexico.

491. A. occidentalis (Whiteaves). (Fig. 734.) Comanchic.

ii . E eS
Fic. 734. Arctica occidentalis, right valve. (Aftér Stanton. )

—>

538 NORTH AMERICAN INDEX FOSSILS. 3

Beaks broad and prominent.

Knoxville of California; Queen Charlotte of Queen Charlotte
Islands.
492. A. ovata (Meek and Hayden). Cretacic.

Transversely ovate. Beaks rather small and not much elevated.
Surface marked with distinct growth lines. Length 21 inches;
height nearly 2 inches. |

Montanan : North Dakota, Montana, Alberta, Assiniboia, Sas-
katchewan.

CXXXVI. VENIELLA Stoliczka.

Very similar to Arctica, but the left valve has the anterior car-
dinal teeth strong and subtriangular and there is present a more
or less pronounced posterior umbonal slope. Cretacic—Tertiary.

493. V. conradi (Morton). (Fig. 735.) Cretacic.

Fic. 735. Veniella conradi. (N. J. Pal., I.)

Surface marked with several strong projecting growth lamellae
which do not extend across the posterior umbonal slope. A low
subangular ridge curves from the beak to the posterior extremity
of the hinge line.

Ripleyan of New Jersey (Merchantville — Tinton), Gulf region.

494. V. trigona (Gabb). (Fig. 736.) Cretacic.

Fic. 736. Veniella trigona Gabb. (N. J. Pal., I.)

PELECYPODA—TELEODESMACEA. 539

Differs from V. conrad in its thicker and larger shell, and pres-
ence of the projecting growth lamelle only upon the younger
portion of the shell ; the rest being covered only by strong wrinkle-
like ridges.

Ripleyan of New Jersey (Navesink, Tinton), Gulf region.

495. V. mortoni Meek and Hayden. Cretacic.

Differs from V. ¢vzgona in being more oblique, more depressed
at the beaks, which are also placed directly over the more trun-
cated anterior margin. Dorsal margin also longer, giving it a
greater proportional length, and less sloping.

Benton : Colorado, Montana.

496. V. humilis Meek and Hayden. (Fig. 737.) Cretacic.

Fic. 737. Veniella humilis, anterior and left views. (After Meek, Surv. Terr., 1X.)

Umbonal slope rounded. Surface concentrically striated.
Fox Hills: South Dakota, Wyoming, Colorado.

CXXXVII. AstartEe Sowerby.

Shell thick, inequilateral, usually rounded triangular or oval,
closed, with smooth or concentrically sculptured exterior. Epi-
dermis thick. Lunule impressed; escutcheon elongate. Ligament
external. Two cardinal teeth present in each valve; the right an-
terior strong. Lateral teeth rudimentary. Adductor scars strong,
nearly equal; above the anterior is a pedal impression. Pallial
line simple. Jurassic—-Recent.

497. A. carlottensis Whiteaves. Comanchic.

Subcircular to transversely subovate in outline, moderately and
regularly convex. Length and height about equal. Margin form-
ing a continuous subelliptical curve from the posterior end of the
hinge to the lower end of the lunule. Hinge short and gently
convex. Beaks about half way between the middle and anterior

540 NORTH AMERICAN INDEX FOSSILS.

margin, prominent, turned forward. Lunule large, deeply and
sharply impressed. Surface crossed by numerous, regular, con-
centric undulations. Average measurements of two types : length
and height 20 mm.; length 26 mm., height 20 mm.

Queen Charlotte Islands, Vancouver.

498. A. trapezoidalis Stanton. (Fig. 738.) — Comanchic.

: = ie ee
Fic. 738. Astarte (?) trapezoidalis, right and cardinal views. (After Stanton.)

Shell elongate, marked with a broadly rounded umbonal ridge
and crossed by prominent, subangular, concentric ridges.
Knoxville : California. |

CXXXVIII. Opis Defrance.

Trigonal cordate, smooth or concentrically striate, with pro-
nounced epidermis. Beaks prominent, curving strongly so as to be
concave forward. Lunule very deep, bordered by a keel. Cardi-
nal teeth very long, narrow; one in the right valve, two in the left.
Triassic—Cretacic.

499. O. californica Stanton. (Fig. 739.) , Comanchic.

Fic. 739. Opis californica, two views of the right and one of the left valve.
(After Stanton. )
Surface marked with fine growth lines and more distant, irregu-

lar, concentric furrows.
Knoxville: California, Oregon.

CXXXIX. CRASSATELLITES Kruger.

Shell solid, attenuated behind. Umbos small, close together.
Lunule distinct. Resilifer present beneath the umbo. Hinge

PELECYPODA—TELEODESMACEA. 541

plate heavy, flat, with two cardinal teeth in each valve; lateral
teeth present, one (posterior) in each valve, with a small anterior
lateral at times in the right valve. Free margins of valves crenate.
Adductor impressions deep. Pallial line simple. Cretacic-Recent.

500. C. aleformis (Conrad). (Fig. 740, a, 0.) Eocenic.

Fic. 740. a, 6, Crassatellites aleformis, left and right valves; ¢, d@, C. aguiana, left
and cardinal views. (Md. Surv.)

Base of attenuated posterior portion varying from broadly convex
to broadly concave ; sculpture strong.
Very abundant in the Aquia of Maryland.

501. C. aquianus (Clark). (Fig. 740, ¢, d@.) Eocenic.
Differs from C. aleformis in its shorter and broader posterior
extremity, its higher umbos, and the absence of deep prominent
furrows on the umbos.
Aquia of Maryland.

502. C. gabbi Safford. (Fig. 741.) Eocenic.
Surface marked with heavy concentric ribs which become faint
at the posterior umbonal slope.
Midway: Gulf region.

542 NORTH AMERICAN INDEX FOSSILS.

503. C. halei Harris. Eocenic.
No posterior umbonal slope present.
Lignitic: Georgia, Alabama.

Fic. 741. Crassatellites gabbi, interior and exterior of the left valve and hinge,
enlarged. (After Harris. )

CXL;. Etrea Conrad.

Differs from Crassatellites in the absence of crenulations on the
inner free margins of the valves and in the hinge characters, pos-
sessing beside its two cardinal teeth, an elongate anterior and a
posterior lateral tooth in each valve ; anterior cardinal of left valve
triangular, fitting into a triangular pit of the right valve between
the two cardinal teeth of that valve. Cretacic.

504. E. carolinensis Conrad. Cretacic.
Umbonal ridge subcarinate. Surface of shell marked with
strong, more or less irregular concentric growth lines.
Abundant in Ripleyan (Marshalltown) of New Jersey. Also in
North Carolina.

505. E. trapezoidea (Conrad). Cretacic.
Less elongate than &. carolinensis and its posterior obliquely
truncate margin is longer than in that species.
Ripleyan of New Jersey (Merchantville), Alabama, Texas.

CXLI. Prycuomya Agassiz.

Like Crassatelhtes but with radial sculpture and with three
cardinal teeth in each valve, the posterior being very long and
double in the right valve, with resilifer in front. Comanchic—
Cretacic.

506. P. ragsdalei (Cragin). (Figs. 742-743.) Comanchic.
Of medium size to large. Radial ribs in three systems which
run at angles to one another.

PELECYPODA—TELEODESMACEA. 543

Common in Comanchic of Texas.

Fic. 742. Ptychomya ragsdale?, interior 1%. (After Shattuck. )
Fic. 743. Ptychomya ragsdalei,; fragment of exterior. (After Shattuck. )

CXLII. Corsicuta Megerle von Muhlfeld.

Shell porcelaneous, with conspicuous epidermis-and marked with
concentric growth lines. Pallial line simple or with slight sinus.
Ligament prominent, external. Adductor scars nearly equal.
Hinge with anterior and posterior laterals distinctly separated from
the cardinals and sharply cross striated. Cardinal teeth bifid at
summit and usually three in each valve. Fresh and brackish
water. Cretacic—Recent. |

507. C. durkei Meek. (Fig. 744, a—c.) Cretacie:
Beaks very strongly incurved.

ee

Fic. 744. a-c, Corbicula durkei; d—f, Spherium formosum, natural size and
enlargements ; g, 2, Sph. planum. (After White. )

544 NORTH AMERICAN INDEX FOSSILS.

Very abundant in the Bear River of Wyoming, Utah and Idaho.
508. C. occidentalis Meek and Hayden. Cretacic.

Shell thick, subtrigonal. Average length and height 1 inch ;
convexity .75 inch. Slopes from beak subequal ; the anterior
slightly concave, the posterior somewhat convex. Base broadly
curved. Beaks elevated, gibbous.

Especially abundant in the brackish water strata of the Mon-
tanan of Wyoming, Montana, Assiniboia, Alberta; also present in
the Laramie throughout this region.

CXLIII. SpxHarium Scopoli.

Small, thin, inflated, rounded. Sculpture concentric, never
strong. Cardinal teeth usually two in each valve, variable, thin,
often nearly parallel to the hinge line or in part defective. Lateral
teeth compressed, lamelliform, the anterior shortest. Ligament.
short and feeble, deep-set in a groove. Muscle impressions near
margin and scarcely apparent. Pallial line simple. Fresh water.
Cretacic—Recent.

509. S. planum Meek and Hayden. (Fig. 744, g,%.) Cretacic.

Much compressed, with very small nearly central beaks that
scarcely rise above the hinge line. Surface marked by obscure
and irregular concentric striz.

Judith River (Pierre): Nebraska, Montana, Assiniboia. Laramie:
Wyoming.

510. S. formosum Meek and Hayden. (Fig. 744, da)
Cretacic—Lower Eocenic.

Very small (length less than .2 inch). Beaks somewhat tumid
and rising alittle above the hinge line, a little anterior of the
middle. Surface marked by distinct and regular concentric lines.

Pierre (Belly River) of Alberta and Assiniboia. Fort Union of
Montana.

CXLIV. VeENERIcARDIA Lamarck.

Shell rounded or cordate, inequilateral, with radiating ribs.
Umbos prominent. Basal margin crenulated internally. Liga-
ment external. Hinge thick with no lateral teeth but with the
posterior cardinal much prolonged. Adductor impressions un-
equal. Pallial line simple. Cretacic—Recent.

511. V. smithi Aldrich. (Fig. 747, 0.) Eocenic.

PELECYPODA—TELEODESMACEA. 545

Ribs flat on central part of shell, tuberculated on anterior and
posterior portions.

Midway: Gulf region.
512. V. alticosta Conrad. (Fig. 745.) Eocenic.

ES,

bic. 745. Venericardia alticosta, right valve. (After Harris,
g )
Fic. 746. Venericardia planicosta var, regia, K V4.

Ribs about 22, much elevated and nodulose ; those on anterior
side are laterally keeled.

Claibornian and Jacksonian of Alabama and Louisiana.
513. V. planicosta Lamarck. (Figs. 746 and 747, a.)

Eocenic.
Large, with length at times of 3 or 4 inches.

It has been proposed by some authors to distinguish the Ameri-

Fic. 747. Venericardia planicosta, left valve, and V. smithi, right valve.
(After Harris. )

can representative of the V. planicosta of Europe by the varietal
name of regia.

5406 NORTH AMERICAN INDEX FOSSILS.
Agquia: Maryland. Tejon: California. Eocenic of Alaska.

CXLV. CHAmA Linné.

Unequal, irregular, attached by umbo of left and larger valve.
Beaks more or less spiral, turned forward. Hinge plate heavy.
Hinge teeth one in the free valve; two in the attached, the an-
terior broad and grooved, the posterior long and curved parallel
with the hinge line. Sculpture lamellose and more or less spiny.
Adductor impressions large, oblong, nearly equal. Ligament and
resiliiim external in adeep groove. Shell structure in three layers,
the external colored, laminated with oblique lines of growth and
corrugated at right angles to the laminz, spiny ; the middle layer
corrugated ; the inner translucent and bearing minute processes
that give a granular appearance to the internal molds of the shell.
Sometimes attached by right valve, in which case the dentition is
reversed, the single tooth being always in the free valve. Cretacic—
Recent.

Fic. 748. Chama congregata, interior of left and exterior of right valves.
(Md. Surv.)

Small, plump, usually attached by beak of left valve which is
quite turbinate. Internal margins crenulated. Both valves cov-
ered with scales.

Miocenic: Atlantic coast. Also Recent: North Carolina to
Yucatan. )

CXLVI. Regurenia Matheron.

Usually very inequivalve, attached by umbo of left valve. Left
valve spiral, with deep cavity. Right valve smaller, somewhat
spiral or flat. Teeth feeble. Ligament external. Posterior ad-
ductor scar bordered by a prominent, subspiral ridge in each valve.
Comanchic.

PELECYPODA—TELEODESMACEA. 547

515. R. patagiata White. (Fig. 749, a) Comanchic.

Both valves convex below and flat above, the peripheral angle
formed by the meeting of the upper and under sides is bordered in
the left valve by a thin, somewhat wrinkled carina. Beak of left
valve distorted by attachment. Right valve of more regular shape

Fic. 749. a-c, Reguienia texana, v ew of both valves and of the left and the
right; @—/, XR. patagiata, three views of a specimen with both valves together, « %.
(After White. )

than the left. Surface of both valves marked by irregular con-
centric growth lines.
Fredericksburg : Texas, Mexico.

516. R. texana Roemer. (Fig. 749, a—c.) Comanchic.
Larger, thinner-shelled, than R. patagiata with less prominent

spires and without a prominent carina on the peripheral angle.
Fredericksburg: Texas, Mexico.

CXLVII. Monoprteura Matheron.

Very inequivalve, smooth or ribbed, attached by right valve
which may be either twisted or coniform. Left valve conical
or flat. Dentition: two cardinals in free valve, and one in the
attached. Ligament external in a deep groove. Posterior adduc-
tor scar buttressed. Shell substance without canals. Shell often
found in groups adhering laterally. Comanchic.

548 NORT IL AMERICANS INDEX FOSSILS.

517. M. texana Roemer. (Fig. 750.) Comanchic.
Right valve low, conical, with angular umbonal ridge; left valve
gently convex.
Fredericksburg : Texas, Mexico.

Fic. 750. onopleura texana, a, large valve from above; 4, showing
both valves. (After Roemer. )

518. M. pinguiscula White. (Fig. 751, a, 0.) Comanchic.
Right valve elongate. Radiating lines very much fainter than
in 7. marcida. Individuals apparently grew separately.
Upper Fredericksburg of Texas.

519. M. marcida White. (Fig. 751, ¢, @.) Comanchic.

Fic. 751. a, 6, Monopleura pinguiscula ; c,d, M. marcida. (After White.) ;

Surface of both valves covered with numerous raised radiating
lines besides the concentric growth lines. The individuals often
grew in clusters.

Upper Fredericksburg of Texas.

PELECYPODA—TELEODESMACEA. 549

CXLVIII. Caprina d’Orbigny.

Very inequivalve, attached by the coniform right valve which is
marked only with growth lines and possesses an almost internal
ligament groove. Hinge margin, with several deep cartilage pits
and with one large posterior tooth. Left valve large, spirally
twisted ; anterior tooth supported by a plate which divides the
umbonal cavity lengthwise; posterior teeth obscure. Inner layer
of lower (right) valve made up of concentric lamella between
which cavities are sometimes left. The middle layer of the free
valve traversed by numerous simple, wide, parallel canals, extend-
ing from the margin to the apex. A series of depressions present
between the posterior adductor scar and the margin. Comanchic.
520. C. crassifibra Roemer. (Fig. 752.) Comanchic.

Larger free valve spiral, tortuous or sickle-shaped.

Upper Fredericksburg and lower Washita : Texas.

FIG. 752. Caprina crassifibra ; a, complete valve, partly worn towards the end;
6, section of the same. (After Roemer. )

521. C. occidentalis Conrad. (Fig. 753.) Comanchic.
Sickle-shaped, flattened on the side of the outer curve, convex
on the opposite side. Outer margins acutely rounded. Surface

550 NORTH AMERICAN INDEX FOSSILS.

very obscurely striated transversely. Substance coarsely fibrous.
Upper Fredericksburg: Texas.

FIG. 753. Caprina occidentalis, views of both sides and cross section of left
valve, Xx %. (After Meek, Mex. Bd. Surv.)

=

Fic. 754. Jchthyosarcolites anguis, complete individual with united valves and longi-
tudinal section of a part of a larger shell. (After Roemer. )

PELECYPODA—TELEODESMACEA.

551

CXLIX. IcHTHYOSARCOLITES Desm.

Fixed by right valve or free.
open tubes with a thin superficial lamina.
tained in several deep pits.

Composed of a thick layer of
Cartilage internal, con-
Umbos more or less chambered.

Right valve conical or elongated, with ligament furrow on the

convex side.

Hinge with one oblique plate.

Left valve oblique

or spiral ; hinge with two teeth, the anterior supported by a plate

which divides the umbonal cavity lengthwise.
(Fig. 754.)

522. I. anguis Roemer.

Comanchic.
Comanchic.

Lower valve elongate, snake- like, at times a foot long and over

one inch thick. Ligament
furrow runs entire length
of shell. Transverse sec-
tion of valve oval or subtri-
gonal. Upper or free valve
spirally once enrolled.

Upper Fredericksburg :
Texas.

CL. CoRALLIOCHAMA
White.

Shell a large cone fixed
by apex of lower (right)
valve growing separate or
in clusters, thick, of three
layers, the outer prismatic,
the middle cellular, the in-
ner porcelainous ; lower
valve irregularly conical,
somewhat distorted, upper
valve convex with broad
incurved beak. Hinge sim-
ilar to preceding. Cretatic.

523. C. orcutti White.
(Fig. 755.) Cretacic.
Type of genus. The cel-

lular portion of the shell

resembles /avosites. (See

Balw. S, G. S. No. 22.)

wiDNd:

~
a}

MLM ATR.

Tit

Re
Yj
minty
is
Is
ov
i
oe
A)
AS
Ti

ms wet
ee
se
@,

| earane am DR
BS OSES AY
ea) RRO —
& art Parespsanss NI
‘ i
7.

4, - abs, awe =

RGSS eas

A S
sence en ca

Fic. 755. Coralliochama orcutti ; a, complete
adult shell; 4, diagram of transverse section of
lower valve, showing outer prismatic, inner por-
celainous and middle cellular layers; c, section of
part of upper valve; d, fragment of lower valve
showing cellular structure, All, & %. (After
White. )

552 NORTH AMERICAN INDEX FOSSILS.

Lower Chico of California and Lower California.

CLI. Rapro.iteEs Lamarck.

Lower valve conical, erect, elongated, vertically ribbed or made
up of successive layers ; usually with two, somewhat smooth bands
extending from the apex to the upper margin, probably marking
the position of the siphon openings. Outer layer very thick, com-
posed of large, polygonal cells or hollow prisms. Upper valve

Fic, 756. Radiolites texanus, large valve. (After Roemer. )
Fic. 757. Radiolites texanus, section enlarged. (After Roemer.)

PELECYPODA—TELEODESMACEA. 553

operculum-like, flat or conical, with central or eccentric umbo.

Teeth not forming the hinge but specially modified for the verti-

cal motion of the operculum-like valve; they consist of two

vertically striated processes on the smaller valve, fitting into
sockets near the outer wall of the fixed (larger) valve ; next to and
outside of the sockets are two large un-
equal, slightly excavated muscle scars into
which fit the two broad projecting muscle
plates from the upper valve. Pallial line
simple, enclosing the whole cavity. Co-

-manchic—Cretacic.

524. R. texanus Roemer. (Fig. 756-
77.) Comanchic.
Larger valve marked with twelve sub-

equal vertically ridged ribs.

Upper Fredericksburg (Edwards): Texas.

525. R. davidsoni Hill. (Fig. 758.)

Comanchic.
More slender than preceding, with more
numerous and finer ribs.
Upper Fredericksburg: Texas.

526. R. austinensis Roemer. Cretacic.

Larger valve made up of successive lami-
nz which are bound firmly together by
some of the polygonal cells composing
each lamina, being so arranged as to form
furrows upon the inside and ridges on the
outside. These laminz are almost perpen-
dicular to the broad funnel-shaped interior

Fic. 758. Radiolites da-
of the shell. — vidsoni. (After Hill. )
Characteristic of the Austin (Niobrara) of

Texas; and at about the same horizon in San Luis Potosi.

527. R. maximus Logan. Cretacic.
Shell inversely conical. Outer surface of lower valve marked

by parallel longitudinal ridges composed of overlapping plates ;

inner surface smooth. Valve composed of circular plates placed

one upon the other. Upper extremity of lower valve resembling

a flange bent upward and outward. Height of lower valve 3 to 4

554 NORTH VAMERICAN, INDEX FOSSILS.

feet ; diameter at top 10 inches; thickness of outer layer of shell
3 inches.
Niobrara: Kansas.

CLI. Tancrepia Lycett.

Trigonal, usually with nearly central beaks, but anterior side

attenuated and somewhat the longer and posterior wider, shorter,
and usually obliquely truncate. Somewhat gaping posteriorly.
Margins entire. Surface smooth. One cardinal and one posterior
lateral tooth in each valve. Ligament external. Pallial line
simple. Triassic—Cretacic.
528. T. bulbosa Whitfield. (Fig. 759.) Jurassic.
| Anterior portion marked with a broad and
shallow depression. Surface smooth except for
very fine concentric lines.

Sundance: South Dakota, Wyoming.

- 529. T. americana Meek and Hayden.

Fic. 759. TZan- Cretacic.
credia bulbosa. 3 z Z
(Rites Sagat) Thick. Posterior end broader than anterior,

: obliquely truncate and gaping above. Anterior
narrow and somewhat rostrated. Hinge line slightly concave
anterior to beaks and convex posteriorly. Beaks small. Length
2.5 inches. :

Montanan: Colorado, Alberta, Assiniboia.

CIE. PARACYCEAS: Hall

Suborbicular, thin-shelled, with small and low beaks and short
hinge line. Posterior portion near the beaks more or less defined
by an oblique furrow, sometimes with posterior hinge extremity
almost winged. Surface marked with concentric striz which are
often developed into ridges. No lunule present. Ligament set in
a deep groove. Pallial line simple. Devonic.

530. P. ohioensis (Meek). (Fig. 760, c.) Devonic.
_ Anterior end produced and flattened. Concentric striz very
fine. Rather small. :

- Onondaga: Ohio, Indiana.

531. P. elliptica Hall. (Fig. 760, a.) Devonic.

Large. Concentric striz lamellose at irregular intervals.

PELECYPODA—TELEODESMACEA. 555

Onondaga: New York, Ohio, Michigan, Ontario. Also more
rarely in the Hamilton.
532. P. lirata (Conrad). (Fig. 760, 0.) Devonic.

Smaller than P. e/iptica and more uniformly marked with less
angular concentric ridges.

Hamilton: New York—Iowa, Ontario. More rarely in the

Fic, 760. a, Paracyclas chemungensis,; 6, P. lirata; c, P. ohioensis, right valve ;
d, P. elliptica, left valve. (Pal. N. Y., V.)

Onondaga. Abundant in Portage of New York and Pennsylvania.
533. P. chemungensis Hall. (Fig. 760, a.) Devonic.
Differs from P. e/iptica in its more prominent beaks and in the
finer more regular concentric striz.
Chemung Group: New York?, Pennsylvania.

CLIV. Lucina Bruguiére.

Shell thin, rounded, convex or lens-shaped, slightly inequilat-
eral, equivalve. Shell substance porcelaneous orchalky. Lunule
deep and narrow ; no visible escutcheon present. An oblique fur-
row extends from the umbo to the posterior border. Hinge, usually
with two cardinal teeth and one or two lateral in each valve ; either
the lateral or cardinal may be absent. Ligament and resilium
deeply inset but visible. Anterior adductor scar elongated and
placed mostly within the pallial line. Pallial line entire. Surface
concentrically striated. Triassic-Recent.

rem rremicter less than .35 INC sy... 6... -0ces0csceeccsenvbvadelerdsrvciestesvasccdnethaes I,
NNUAL PEBENE Sf 7, 5c concapruvavses onewdeveeduaeasecacscenecuns 538. L. smithi.
oe merarior 101d: Hot present; .5.-...5.....cevessecadysoeesdevecedieatesseeves 539. L. curta.

or medium size—diameter about .5 InCh..............ccecececvedenccessesceccesevcsdesecs II
Seemeaiaal Maroin nearly Straights ch. cuc..sacdessssecndv ocaeuttohesedscstapaescsccsiesepe r.

1. Concentric undulations large and distant..................... 535. L. cretacea.
1. Concentric undulations small and closed................... 534. L. subundata.
II. Hinge line rounded.............. idee tah rea he Bagh er ey EN 537. L. aguiana.

C. Large — diameter over 1 inch....... Rr oh Se PR 536. L. occidentalis.

556 NORTH AMERICAN INDEX FOSSILS.

534. L. subundata Hall and Meek. Cretacic.
Similar to L. cretacea in form but is usually smaller, rarely reach-
ing .5 inch in height, and with finer and closer concentric lines.
Coloradoan: Utah. Pierre: South Dakota, Montana, Assiniboia.
Fox Hills of Wyoming.

535. L. cretacea Whitfield. Cretaciz:

Hinge line nearly straight. Surface marked with a deep con-
striction passing from the beak to the posterior margin. Concen-
tric lines distant and lamellose.

New Jersey (Cliffwood—Red Bank).

536. L. occidentalis Morton. (Fig.
761.) Cretacic.
Broadly oval, rounded anteriorly,

somewhat truncated posteriorly. Poste-

rior flattening of shell nearly obsolete.

Hinge line nearly straight, slightly de-

clining posteriorly. Surface crossed by
Fic. 761. Luctna occidenia- distinct concentric lines.- . Largevspeem

zs, left valve. (After Gilbert. ) pa measure — height 1.5 inches ;

length slightly more.
Pierre: Colorado and Kansas—Canada. Fox Hills of South
Dakota.

537. L. aquiana Clark. (Fig. 762, c, d.) Hote

Fic. 762. a, 6, Lucina curta (L. uhleri Clark), left valve; c, d, L. aguiana, right ©
valve ; ¢, L. smithi (L. whitei Clark), left valve. All enlarged. (Md. Surv.)

PELECYPODA—TELEODESMACEA. 557

Nearly circular. Concentric strize very fine.
Maryland, Virginia.
538. L. smithi O. Meyer. (ZL. whitei Clark.) (Fig. 762, ¢.)
Eocenic.
Surface marked with strong concentric lamellz and posteriorly
by a shallow fold extending backward from the umbo. Margin
crenulated.
Maryland—Louisiana.
539. L. curta Conrad. (L. whleri Clark.) (Fig. 762, a, 0.)
Eocenic and Oligocenic.
_ Similar to L. smzthi in size and shape but differs in the smooth
margin and absence of posterior fold.
Chickasawan—Vicksburgian: Maryland and Gulf region.

CLV. DripLtoponta Brown.

Thin-shelled, orbicular, convex, concentrically striate or pustu-
lose. Cardinal teeth two in each valve, the left anterior and the
right posterior bifid; laterals obscure or absent. Adductor scars
continuous peripherally with the pallial line. Tertiary—Recent.

Fic. 763. a, 6, Diplodonta acclinis, right valve; c, d, D. hopkinsensis. (Md. Surv.)

540. D. hopkinsensis Clark. (Fig. 763, c¢, a.) Eocenic.
Shell globose. Umbones rather prominent.

558 NORTH AMERICAN INDEX FOSSILS.

Common in the Chickasawan (Lignitic) of Atlantic and Gulf
region.
541. D. acclinis Conrad. (Fig. 763, a, 0.)

Miocenic and Pliocenic.
More transverse. Growth lines strong.

Characteristic of the Miocenic of New Jersey—North Carolina.
Pliocenic : South Carolina and Florida.

CLVI. TrEnea Conrad.

Subcircular, thin-shelled, tumid. Left valve with V-shaped
cardinal tooth, the anterior lobe of which is continued along the
anterior margin of the shell and separated from it by a deep groove.
Right valve with two cardinal teeth, the anterior falcate, the pos-
terior curved backwards. No laterals present. Valve margins
smooth. Pallial line with a narrow and deep sinus. Cretacic.

542. T. parilis Conrad. (Fig. 764.) Cretacic.

a a a EE oo oO ee ere ers 4 Se eee

Fic. 764. TZenea parilis. (N.J. Pal., 1.)

Surface nearly smooth, marked only by fine growth lines. At
times 1.5 inches in diameter.

Widely distributed through the upper Cretacic of New Jersey,
also in North Carolina and Gulf region.

CLVII. Carpium Linné.

Convex, nearly equilateral, rounded-oval. Umbones prominent,
incurved, turned slightly forward. Surface marked with radiating,
often spiny ribs. Margins of valves crenulated. Two cardinal
teeth, one anterior lateral and one posterior in each valve. No
lunule nor escutcheon present. Ligament external. Adductor
impressions shallow. Triassic-Recent. |
543. C. pauperculum Meek. (Fig. 765.) Cretacic.

Height slightly exceeding length. Diameter .5 to .75 inch.
Specimens are usually flattened or otherwise distorted. When the

PELECYPODA—TELEODESMACEA. 559

plications are preserved an angular appearance is given to the
posterior umbonal slope by the greater elevation of three or four
of the plications there.
Coloradoan : Wyoming, Utah, Colorado, New Mexico.
544. C. speciosum Meek and Hayden. Cretacic.
Subcircular, with height slightly ex-
ceeding length. Beaks almost central.
Surface marked with numerous, very
regular, radiating ribs; in the grooves
between these are regularly arranged
series of small tubercles. Average diam-

; Fic. 765. Cardium pauper-
eter slightly over .5 inch. culum, right valve enlarged.

Montanan: Colorado, Montana. (After Stanton. )

545. C. tenuistriatum (Whitfield). (Figs. 766; 767.) Cretacic.
Internal molds strongly gibbous and with abrupt posterior slope.
Ripleyan of New Jersey (Merchantville—Navesink ; the most com-

mon and widely distributed Cardium of the New Jersey Cretacic).

Fic. 766. Cardium tenuistriatum, (N. J. Pal., I.)

546. C. eufaulensis Conrad. Cretacic.
Height exceeding length; hinge arcuate; shell narrower than
preceding with stronger angular costz (35-40).
Ripleyan of New Jersey (Wenonah)—Mississippi.
547. C. spillmani Conrad. Cretacic.
Usually occurs as internal molds which are larger than those of
C. kimmel, with more anteriorly curved beaks, and with radiat-
ing ribs on posterior portion.
New Jersey (Merchantville and Navesink)-Texas and Ok-
lahoma. :

560 NORTH AMERICAN INDEX FOSSILS.

548. C. kummeli Weller. Cretacic.

When found as internal molds it is like the molds of C. spzll-
mant in its long and slender form, but it is not usually so large,
and lacks the radial ribs which are
usually impressed on the posterior
slope of those molds.

Ripleyan of New Jersey (Nave-
sink—Tinton), Alabama, Mississippi.
549. C. meekianum Gabb.

Pliocenic.

Large (over 2.5 inches in height),
oblique, with abruptly truncated
posterior end and prominent and
rounded anterior. Radiating ribs

about 22, absent from the posterior
Fic. 767. Cayenne tenuistriatum, slope, large and flattened on top.
Se eer rae a ean Me nel croaeed by irregular lamellose

Pal., I.)
concentric lines which become tu-

bercles toward the beaks. |
Upper and Lower Pliocenic and possibly Miocenic of California.

CLVIII. Prorocarpia Beyrich.

Similar to Cardium but with radiating ribs only on posterior
portion of shell, the remainder covered with concentric ridges. No
lunule or escutcheon present. Comanchic—Recent.

550. P. texana Conrad. (Fig. 768.) Comanchic.
Small to very large (over three inches long).
Posterior fifth of shell covered with about fifteen
radiating ribs.
Washita of Colorado, Texas (especially com-
mon in the Buda).

551. P. subquadrata Evans and Shumard. Fig: 73 ee
tocardia texana.

Cretacic. (After Shattuck).
Small (diameter less than .5 inch), more quad-

angular than P. Zenzs with posterior margin truncated. Gibbous.
Radial ribs of posterior portion somewhat obscure.

Montanan: North Dakota, South Dakota, Wyoming, Assini-
boia, Saskatchewan.

PELECYPODA—TELEODESMACEA. 561

552. P. lenis Conrad. (Fig. 769.) Eocenic.

Fig. 769. Protocardia lenis, right valve. (Md. Surv.)

Posterior margin oblique. Radiating lines about 22.
Pamunkey of Maryland, Virginia, Alabama (Lignitic).

CLIX. Isocarpia Lamarck.

Inflated, smooth or concentrically striated. Beaks distant,
prominent and much produced and spirally enrolled toward the
front. Each valve with two nearly parallel cardinal teeth and one
posterior lateral. Jurassic—Recent.

553. I. cliffwoodensis Weller. Cretacic.
Ventricose (convexity of valves 6.5 mm.). Beaks small,
strongly incurved and directed forward. Anterior umbonal slope
abrupt ; posterior slope convex. Surface smooth.
Ripleyan of New Jersey (Cliffwood—Wenonah), Texas.

Fic. 770. Jsocardia fraterna, right and left valves, x 24. (Md. Surv. )

554. I. fraterna Say. (Fig. 770.) Miocenic.
Surface crossed by rather large concentric wrinkles.
Maryland—North Carolina.

562 NORTH AMERICAN INDEX FOSSILS.

CLX. CypriIMERIA Conrad.

Similar to Venus but right valve with two cardinal teeth, the
posterior bifid; left valve with three cardinals ; each valve with a
posterior lateral. Pallial sinus very shallow. Resilium usually
external, embraced by the ligament. Comanchic—Cretacic.

555. C. texana (Roemer). (Arcopagia texana.) Comanchic.
Nearly circular, very thin, owing to slight convexity of valves ;

valves slightly unequal with a somewhat twisted appearance.
Very abundant in the Fredericksburg of Texas.

556. C. crassa Meek. Comanchic—Cretacic.
Differs from C. ¢exvana in its larger size and much greater thick-
ness. Height, 67 mm.; length, 78 mm.; depth, 23 mm.
Fredericksburg and Eagle Ford of Texas. Fredericksburg and
Washita of northern Mexico.

557. C. excavata (Morton). Cretacic.
Posterior portion of shell obliquely truncate.
Ripleyan of New Jersey (Marshalltown—Navesink), Gulf region.

CLXI. Crementia Gray.

Thin-shelled, inflated. Beaks prominent. Valve margins entire.
Surface concentrically sculptured. Anterior left and two posterior
right hinge teeth more or less bifid; no lateral teeth present. Pal-
lial sinus long and angular, narrow and ascending. Tertiary—Re-
Cent,

558. C. inoceriformis (Wagner). (Fig. 771.) Miocenic.
Posterior hinge area marked by an angular ridge, which is wedge-

Fic. 771. Clementia inoceriformis, \eft and right valves, & 24. (Md. Surv.)

PELECYPODA—TELEODESMACEA. 563

shaped posteriorly and overlaps a groove which runs backward
from the beak.

Maryland, Massachusetts ?

CLXII. Venus Linne.
Valves equal, inequilateral, oval or rounded, heart-shaped, thick,
concentrically or radiately sculptured. Margins crenulate. Hinge
plate broad, with three cardinal teeth in each valve and no lateral

Fic. 772. Venus mercenaria, right and left valves, & 1%. (Md. Surv.)

teeth. Pallial sinus short, angular. The two adductor scars sub-
marginal. Jurassic-Recent.

559. V.mercenaria Linne. (Fig. 772.) Miocenic—Recent.
Type of genus.
Atlantic coast region.

CLXIII. Merretrix Lamarck.

Thick, trigonal, smooth or concentrically striated. Lunule
well marked. Margin entire. Ligament external. Hinge thick,
with three cardinal teeth in each valve, two laterals in the right
and one in the left, beneath the lunule; no posterior laterals present.
Pallial sinus rather shallow, not acutely angular.

_ Differs from Venus in the possession of lateral teeth, and in
lacking the fine crenulations of the valve margin. Jurassic—-Recent.

560. M. tippana Conrad. (Fig. 773.) Cretacic.
Beaks slightly anterior to center. Length slightly exceeding
height. Concentric lines fine and regular.
Ripleyan of New Jersey (Cliffwood—Wenonah), Arkansas, Mis-
sissippi, Texas. Also Cretacic of Mexico.

564 NORTH AMERICAN INDEX FOSSILS.

561. M. eufaulensis (Conrad). Cretacic:
Nearly rotund. Concentric strie fine and especially conspicuous
and regular for half the distance down from the beak.
Ripleyan of New Jersey (Marshalltown—Navesink), Alabama.

562. M. veta (Whitfield). (Caryatis veta.) Cretacic.
Length less than 1 inch. Pallial line faint and with a deep and

Fic. 773. Meretrix tippana. (N. J. Pal., I.)

narrowly rounded sinus. External surface rarely well preserved,
marked with fine concentric lines.
Jerseyan of New Jersey (Hornerstown—Manasquan).

563. M. ripleyana Gabb. (Fig. 774.)
Cretacic and lower Eocenic.
Shell nearly smooth around the umbo but marked with concen-
tric lines from the middle downwards.
Eocenic (Midway) of Georgia and Texas. Cre-
tacic (Ripley) of Tennessee.

564. M. subimpressa Conrad. (Fig. 775, ad)

Fic. 774. Eocenic.
Meretrix ripley- Produced posteriorly so that length considerably
ana. (After
exceeds breadth.
Harris. )

Maryland (Nanjemoy), Alabama (Lignitic).

565. M. uvasana Conrad. Eocenic.
Over 2 inches long by 1.75 inches high. Beaks nearly ante-
rior. Surface marked with concentric ridges separated by wider
spaces which are either plain or striated.
Tejon: California, Oregon.

566a. M. ovata var. pyga Conrad. (Fig. 775, a,0.) | Eocenic.
Large, thick, ventricose, oval.
Aquia: Maryland.

—

PELECYPODA—TELEODESMACEA. 565

566. M. ovata var. ovata (Rogers). (Fig. 775, c.) Eocenic.
Smaller, thinner and more elongate than JV. ovata var. pyga and
with less rounded basal margin.
Nanjemoy: Maryland.

Fic. 775. a, 6, Meretrix ovata var. pyga, left valve; c, MZ. ovata var. ovata, d-f,
M. subimpressa. (Md. Surv.)

CLXIV. Dosrniopsis Conrad.

Very similar to Meretrix but the pallial sinus is acutely angular
and ascending. Beside the anterior lateral teeth there is a single
distinct posterior lateral in the right valve with a corresponding
socket in the left. Posterior cardinal of right valve broad and
deeply channeled above. Shell rotund. Cretacic-Eocenic.

567. D. deweyi Meek and Hayden. Cretacic.
Broadly oval, with length slightly exceeding height, rather thin-
shelled, moderately convex. Beaks nearly central, somewhat
gibbous and incurved to nearly meet each other. Surface marked
by fine and regular concentric lines. Diameter slightly less than
Iinch. Pallial sinus narrowly rounded at apex.
Montanan: North Dakota, South Dakota, Montana, Colorado,
Wyoming, Assiniboia.
568. D. owenana Meek and Hayden. Cretacic.

566 NORTH AMERICAN INDEX FOSSILS.

Like D. deweyz in shape, but thick-shelled and larger (diameter
about I.5 inches). Concentric striz moderately distinct.
Fox Hills: Montana, Colorado.

569. D. nebrascensis Meek and Hayden. Cretacic.
Lunule and escutcheon both prominent. Slightly smaller than
D. owenana but more nearly circular, the height being about seven
eighths the length. Pallial sinus narrowly rounded at apex.
Fox Hills: Nebraska-Wyoming, Assiniboia, North Dakota?
Pierre: South Dakota.

570. D. lenticularis (Rogers). (Fig. 776.) Eocenic.

Fic. 776. Dosiniopsis lenticularis, right valves and cardinal view,

x %. (Md. Surv. )

Shell varying from moderately thin to heavy. Diameter about
2 inches or more. Type of genus.
Aquia: Maryland.

CLXV. Tapes Megerle von Muhlfeld.

More or less elongate-oval, with narrow hinge plate, divergent
and often bifid cardinal teeth, no laterals, and a deep pallial sinus.
Differs from Venus in the absence of lateral teeth; also the inner
margins of valves are smooth. Comanchic—Recent.

571. T. hilgardi Shumard. Comanchic—Cretacic.

Benton (Eagle Ford) of Texas. Fredericksburg and Washita of
Mexico.

CLXVI. Texxina Linné.

Oval, transversely elongate, slightly inequivalve, compressed,
rounded anteriorly, angular and gaping posteriorly. Surface
marked with an oblique fold extending from the umbo to the
lower posterior border. Beaks more or less twisted. Margins of
valves smooth. Two cardinal teeth present in each valve and one

PELECYPODA—TELEODESMACEA. 567

anterior and one posterior lateral. Laterals often indistinct in left
valve. Ligament external, prominent. Pallial sinus very wide and
deep, differing slightly in the opposite valves. Jurassic—Recent.

572. T. equilateralis Meek and Hayden. Cretacic.
Anterior and posterior sides nearly equal. Posterior end

slightly truncated. Umbonal angle about 140°. Posterior slope

more convex than anterior and slightly excavated for the reception

of the ligament. Umbonal ridge not very distinctly marked.

Surface marked with small, irregular concentric wrinkles and ob-

scure growth lines. Length 1.7 inches; height 1 inch.
Montanan: Wyoming, Montana.

573. T. virginiana Clark. (Fig. 777, c.) Eocenic.
Cardinal teeth small; laterals indistinct. Pallial sinus obscure.

Fic. 777. Tellina declivis, left valve; 6, ad, 7. wiliamsz, right valve ;
c, TZ. virginiana, left valve, (Md. Surv. )

Surface covered with fine concentric growth lines.
Maryland, Virginia.

574. T. williamsi Clark. (Fig. 777, 4, d.) Eocenic.
Posterior cardinal tooth bifid. Lateral teeth strongly developed.

Surface covered with elevated, close-set concentric ridges or

lamelle.

Aquia and Nanjemoy: Maryland, Virginia.

575. T. declivis Conrad. (Fig. 777,@.) |Miocenic—Pleistocenic.
Posterior end abruptly declining. Lateral teeth distinct.
Miocenic: New Jersey, Maryland, Virginia. Pliocenic and

Pleistocenic : Florida.

CLXVII. Linearia Conrad.

Differs from TZe//ina in the lengthening of the bifid cardinal
teeth, the rounding of the shell posteriorly and anteriorly, the sur-
face partially or wholly radiately ribbed ; umbonal ridge obsolete.
Cretacic. |

568 NORTH AMERICAN INDEX FOSSILS.

576. L. metastriata Conrad. (Fig. 778.) Cretacic.
Surface marked with ‘fine concentric and coarser radiating ribs,

the latter fainter or obsolete on the central portion of the shell.
Ripleyan of New Jersey (Cliffwood—Red Bank), Gulf region.

Fic. 778. Linearia metastriata. (N. J. Pal., I.)

CLXVIII. AEnona Conrad,

Subtriangular, inequilateral. Beaks very small, pointed. Lunule
lanceolate, marked by a deeply impressed line. Two very small,
widely divergent cardinal teeth in the right valve, one bifid and one
rudimentary tooth in the left valve. Cretacic.

Fic. 779. 4£nona eufaulensis, (N. J. Pal., I.)

577. A. eufaulensis Conrad. (Fig. 779.) Cretacic.
Surface smooth and semipolished.
Ripleyan of New Jersey (Woodbury), Alabama, Mississippi,
‘Lexas.
CLXIX. SEMELE Schumacher.

Large, rounded, thick. Posterior side slightly folded. Both
cardinal and lateral teeth present. Pallial sinus large and rounded.
Resilifer elongate. External ligament feeble. Tertiary and
Recent.

578. S. carinata (Conrad). Oligocenic—Pliocenic.

Concentric lamellz separated by equal or wider interspaces and
crossed by fine concentric and radial striz.

Uppermost Oligocenic of Florida (possibly as a variety). Mio-
cenic: Maryland—South Carolina. Pliocenic: South Carolina.
579. S. subovata (Say). (Fig. 780, a.) Miocenic.

More oval, thinner than S. carinata, with finer and closer con-
centric striz.

Maryland, Virginia, Texas.

PELECYPODA—TELEODESMACEA. 569

CLXX. CuminGcia Sowerby.

Small, thin, oval, rounded anteriorly, somewhat wedge-shaped
posteriorly. One small cardinal tooth ineach valve. Right valve
with two strong lateral teeth ; left valve with extended dorsal mar-
gins to fit in the channels above the laterals of the right valve.
These dorsal extensions form a lunule and escutcheon which are
thus nearly confined in the left valve. Surface marked with radi-
ating striz. Concentric lines fine or lamellose. Resilifer spoon-
shaped. Pallial sinus deep and wide.

Habit nestling, z. ¢., though not excavating burrows they occupy
those made by true borers. Eocenic—Recent.

Fic. 780. a, Semele subovata, right valve; 4, c, Cumingia medialis, left valve,
exterior and interior views. (Md, Survey. )

580. C. medialis Conrad. (Fig. 780, 4, c.) Miocenic.
Anterior portion of shell inflated ; posterior depressed. Resilifer
prominent, projecting.
Maryland (Choptank), Virginia, North Carolina, South Carolina.

CLXXI. Sirigua Megerle von Muhlfeld.

Shell flattened, straight. Hinge line feeble with one right and
two left vertical cardinal teeth and in each valve a posterior hori-
zontal tooth. An internal rib runs vertically from the beak.
Cretacic—Recent.

581. S. huerfanensis Stanton. (Fig. 781.) Cretacic.
Shell thin. Average length 2 inches. Interior rib runs

Fic, 781. Siligua huerfanensis, internal mold of right valve retaining portions of
shell and showing pallial sinus. (After Stanton. )

570 NORTH AMERICAN INDEX FOSSILS.

obliquely forward just in front of the beak, ending about half way
between the dorsal and ventral margins.
Benton: Colorado; probably similar age in Utah.

CLXXII. LEPpTOSOLEN Conrad.

Thin. Beaks anterior, Epidermis unpolished. A_ strong
internal rib directed vertically extends from beak to basal margin.
Pallial sinus very shallow. Hinge with a single cardinal tooth in
each valve. Comanchic—Cretacic.

582. L. conradi Meek. Comanchic.

Differs from L. diplicatus in its smaller size (average length 1
inch ; height .35 inch) and in the absence of the two plications.

Upper Comanchic of Kansas and Colorado.

583. L. biplicatus Conrad. Cretacic.

Anterior extremity compressed, marked with two obscure pli-
cations extending obliquely forward and downward from the beak.
Surface covered with inconspicuous growth lines. Average length
1.5 inches ; height .5 inch.

Ripleyan of New Jersey (Cliffwood—Red Bank), Gulf rggion.

CLXXIII. Sotyma Conrad.

Elongate-ovate, thin, equilateral, ventricose.
Right valve with two cardinal teeth. Cre-
tacic.

ee 584. S. lineolata Conrad. (Figs. 782, 783.)

Fic. 782. Solyma lin- Crete

eolata. (After Whitfield, ( ? ey

Pal. N. J., I.) Posterior margin truncate. Both anterior

and posterior umbonal slopes marked by an

obscure ridge. Surface of internal molds marked with fine and
jtregular concentric lines. Type of genus.

Fic. 783. Solyma lineolata, interior of Fig. 782 and enlargement of hinge.
(After Whitfield, Pal, N. J., I.)

Ripleyan of New Jersey (Cliffwood—Red Bank), Georgia.

PELECYPODA—TELEODESMACEA. 571

CLXXIV. LEGUMEN Conrad.

Equivalve, very inequilateral. Hinge with two slender teeth in
the right valve under the beak, and one posterior, very oblique,
and prominently lamelliform lateral tooth. Cretacic.

585. L. planulatum (Conrad). (Fig. 794.) Cretacic.

Anterior muscle scar bounded posteriorly by a low ridge which
curves forward below. Surface covered with concentric growth
lines.

Ripleyan of New Jersey (Merchantville-Red Bank), Gulf region,
Montanan of Wyoming.

CLXXV. Mactra Linné.

Nearly equilateral, rounded-triangular. Surface smooth or con-
centrically sculptured. Margins smooth. Valves equal. Cardi-
nal teeth in right valve two, soldered together dorsally ; one
cardinal in left valve. Lateral teeth elongate. Hinge plate well
developed. Resilifer subtriangular, excavated out of hinge plate
and separated from the scar of the external ligament by a thin

Fic. 784. Mactra clathrodon, interior and exterior of left and interior of
right valve. (Md. Survey.)

raised plate, just posterior to the beak at the margin of the shell.

Tertiary—Recent.

586. M. clathrodon Lea. (Fig. 784.) Miocenic.
Shell thin. Lateral teeth crossed by equidistant, minute striz.
Maryland (St. Marys and Calvert).

CLXXVI. CymsBorHora Gabb.
Like Wactra but the ligament area and the resilifer are not
separated by a plate. Margins of the pit holding ligament and
resilium are elevated above the hinge line. Cretacic.

572 NORTH AMERICAN INDEX FOSSILS.

587. C. ashburneri Gabb. Cretacic.
Subtrigonal. Average length 1.62 inches; height 1.25 inches.
Beaks subcentral. Anterior border slightly concave; posterior
straight ; basal broadly rounded. Angle between the cardinal mar-
gins at umbo 90°. Regularly rounded concentric ribs numerous,
few, or absent.
Very abundant in Chico of California and Washington.

Fic. 785. a, Cymbophora utahensts, right valve ; 4,c, C. emmonsi, left valve. (After
Stanton. )

588. C.? utahensis Meek. (Fig. 785, a.) Cretacic.
Beaks incurved, with little obliquity. Growth lines fine and
obscure.
Coloradoan of Utah.
589. C. alta Meek and Hayden. (Fig. 786.) Cretacic.
Thin-shelled. Dorsal slopes diverging from the beaks at an
angle of about 110°. Extremities subangular or abruptly rounded.
Base forming a broad, semi-oval curve. Beaks very elevated,

Fic. 786. Cymbophora alta, right valves, interior and exterior, x 24. (After Meek,
Surv. Terr., IX.)

small or pointed, incurved, and very nearly central. Lunule and

escutcheon lance-oval, the latter the larger and bounded by a dis-

tinctly angular ridge. Surface concentrically striated. Average

length 2.6 inches; height 2.2 inches; convexity 1.2 inches.
Montanan: Colorado—Alberta.

PELECYPODA—TELEODESMACEA. 573

590. C. lintea (Conrad). Cretacic.
Beaks slightly incurved. Umbonal ridge more or less obscure.
Concentric growth lines regular.
Ripleyan of New Jersey (Cliffwood—Tinton), Gulf region.
591. C. emmonsi (Meek). (Fig. 785, 4, c.) Cretacic.
Surface marked with fine and obscure concentric growth lines.
Pallial sinus short, rounded.
Coloradoan: Kansas, Colorado, Montana ?, Utah.
592. C. warrenana Meek and Hayden. Cretacic.
Differs from C. emmonsz in its larger size (average length 1.5
inches; height 1 inch), more convex valves, coarser concentric
strie, more gently rounded base and more prominent umbo.
Angle between cardinal borders 110°.
Montanan of Colorado—Assiniboia ; especially in the Fox Hills.

CLX XVII. ScuizopEsma Gray.

Very similar to Cymbophora but lacking the
elevated margins of the ‘“‘pit.” Pallial sinus
angular. Ligament scar connected with the
upper part of the resilifer. Ligament and re-
silium only slightly separated by a strong rib aE ae eet
which has in one valve developed a small gy,,,500. (Me J, Bak,
tooth or projection and in the other an obscure I.)
socket to receive it. Cretacic—Recent.

593. S. appressa Gabb. (Fig. 787.) Cretacic.

Beaks prominent, nearly erect. Surface concentrically striated.

New Jersey (Cliffwood—Wenonah), Georgia, Texas.

CLXXVIII. Corsura Lamarck.

Shell ovate, very inequivalve, closed, rounded in front, contracted
behind. Umbones prominent. Right valve convex, the larger with
a strong cardinal tooth in front of the resilifer, and also a posterior
cardinal tooth. Left valve also with a resilifer and with one pos-
terior cardinal tooth. Pallial line slightly sinuous posteriorly.
Triassic—Recent.

594. C. pyriformis Meek. (Fig. 788, a—d.) Cretacic.

Surface crossed by concentric ridges and furrows most strongly
defined on the umbonal region; at times only growth lines
present.

574 NORTH AMERICAN INDEX FOSSILS.

Very abundant in Bear River of Wyoming, Idaho and Utah.

595. C. engelmanni Meek. (Fig. 788, e, f) Cretacic.
Differs from C. pyriformis in its smaller size, different outline,
less convexity of valves and less incurving of beaks.
Bear River: Wyoming, Idaho.

596. C. subtrigonalis Meek and Hayden. Cretacic.

Fic. 788. a-d, Corbula pyriformis, right, cardinal, anterior views of complete shell,
interior of left valve. e, 7, C. engelmanni. (After White. )

Outline triangular. Very convex. Average length .75 inch;
height .5 inch. Anterior end abruptly rounded ; posterior longer
and more angular. Umbonal angle about 90°. Beak incurved,
gibbous. Posterior umbonal slope subangular. Surface marked
with concentric lines and a few growth ridges.

Especially abundant in the Montanan (brackish water beds) of
Wyoming, Montana, Assiniboia. Also present in the Coloradoan
and Laramie.

597. C. bisulcata Conrad. Cretacic.
Beak small, incurved. Surface crossed by fine concentric growth
lines.
Ripleyan of New Jersey (Cliffwood—Woodbury), North Caro-
lina, Mississippi, Arkansas.
598. C. crassiplica Gabb. Cretacic.
Beaks large, inflated, enrolled, a little anterior of middle. Left
valve much the less convex and without the strong concentric ribs
of the right valve.

PELECYPODA—TELEODESMACEA. 575

Merchantville-Red Bank of New Jersey; especially character-
istic of the Woodbury. Also in Mississippi, Arkansas, Texas.

599. C. subcompressa Gabb. (Fig. 789.)

Eocenic.
Umbonal ridge angular with slope abrupt.
Midway (basal Eocenic) of Alabama, Tennessee, Fic. 789.
Arkansas. Corbula subcom-
ay : pressa, (After
600. C. aldrichi Meyer. (Fig. 790, d, ¢.) Peis.)
Eocenic.

Umbos without concentric lines but marked with radiating striz.
Maryland, Alabama.

601. C. oniscus Conrad. (Fig. 790, a—c.) Eocenic.
Solid, with numerous and wrinkled concentric lines.
Maryland, Virginia and the Gulf region.

—=ao

Fic. 790. a-c, Corbula oniscus, right valve and cardinal view; @, e, C. aldrichi,
right and left valves, (Md. Surv. )

CLXXIX. Saxicava Fleuriau.

Small, equivalve, oblong, elongated, gaping and hence not fully
covering the animal. Umbones anterior. Ligament external.
Teeth absent in adult; consisting of one or two cardinals in the
young. No laterals present. Surface rugose. Pallial line sinu-
ated, discontinuous. Bores into soft rocks. Tertiary—Recent.
602. S. arctica (Linné). (C. rugosa.) (Fig. 791.)

Miocenic—Recent.

576 NORTH AMERICAN INDEX FOSSILS.

Surface marked with two ridges extending backward from the
beak to the margin.

Miocenic: New Jersey, Maryland, North Carolina, Alaska.
Pliocenic: Florida, California. Pleistocenic: northern America.
Recent : Almost universal in temperate and cooler seas.

Fic. 791. Saxtcava arctica, right and left valves. (Md. Surv.)

CLXXX. Panopea Menard.

Large, thick, equivalve, inequilateral, oblong, gaping widely be-
hind and slightly in front, thus not fully covering the soft parts of
the animal. Shell concentrically striate. Margins smooth. Liga-
ment external on a prominent ridge. An obscure cardinal tooth

in each valve. Pallial sinus very deep. Epidermis conspicuous.
Cretacic—Recent.

603. P. elongata Conrad. (Fig. 792.) Lower Eocenic.

Fic. 792. Panopea elongata, left valve and enlargement of surface. (Md. Surv.)

Concentric striz crossed by close radiating lines of small
granules which, when worn, give the surface a “ honey-combed
appearance.”

Aquia: Maryland, Virginia.

604. P. decisa Conrad. Upper Cretacic.

Surface marked with strong concentric undulations.

Ripleyan of New Jersey (Merchantville-Red Bank), Gulf region.

PELECYPODA—TELEODESMACEA. 577

CLXXXI. Turnus Gabb.

Thin gaping, furrowed from beak to base by an umbonal groove
which appears as a ridge on the interior of the shell. Posterior to
this is another internal ridge, passing likewise from beak to base
but not evident on the surface. The anterobasal portion of the
shell obliquely or angularly truncate, the growth lines curving up
around this truncation. Burrows in wood and secretes a shelly
tube. Cretacic.

605. T. kummeli Weller. ; Cretacic.

Tubes exceedingly contorted ; maximum diameter about .35 inch.
In anterior view the shell is cordate in outline. Beaks in front
of middle of shell, pointed and stongly incurved. Umbones very
prominent. Anterior basal truncation rectangular.

Ripleyan of New Jersey (Marshalltown—Merchantville), Texas.

CLXXXIIL. TEREDO Linné.

Shell much reduced, equivalve, more or less globular, gaping
at both ends. Valves trilobed, with concentric striz. In interior
beneath the umbones is a long, narrow plate for the insertion of the
pedal muscles; adductor scars unequal. Pallial
line coincident with the valve margins. Posterior
portion of animal (elongated siphon) covered by
a long calcareous tube, which is cylindrical,
straight or curved. The animal bores into wood,
the valves occupying the bottom of the burrow
and connecting with the exterior by the calcare-
ous tube; the external opening is protected by
small accessory simple spatulate valves. Juras-
sic—Recent.

606. T. irregularis Gabb. (Fig. 793.)
. Cretacic.

Tubes exceedingly contorted. Shell subglo- Sy
bose, heart-shaped in outline from in front, widely nae ORs ga etaee

F : ; : irregularis. (After
gaping behind, open in front. Beaks a little an- wie) d.)
terior of middle, prominent, much elevated above
the hinge line and strongly incurved. Tubes vary in diameter.

Ripleyan of New Jersey (Magothy and Merchantville), Ar-
kansas.

578 NOKTH AMERICAN INDEX: POSSIES.

CLXXXIII.. Potortuus Gabb.

Teredo-like, calcareous tubes, with habit of boring into sand of
sea bottom instead of wood. Tubes with transverse septa of two
kinds. Bivalve shell of any kind unknown. Cretacic.

607. P. tibialis (Morton). Cretacic.

Septa convex towards the smaller end of tube, perforated cen-
trally by an elliptical slit. Just below the terminal series of septa
is an annular muscle scar. Towards the larger extremity of the
tubes there are one to three transverse septa convex toward the
larger extremity of the tube.

Jerseyan of New Jersey (Vincentown).

Class Scaphopoda Bronn.

The scaphopods are marine mollusks whose bilaterally sym-
metrical body is protected by a tubular shell, which is generally
somewhat curved and open at both ends. The smaller opening
permits the expulsion of waste and genital products, while the
larger one is the anterior or mouth opening. The concave side
of the shell is the dorsal side, and the additions to the shell are
made at the larger end. The smaller end suffers by wear and
resorption, and in some genera becomes notched or slit. The shell
consists of three distinct layers.

The modern species inhabit mostly deeper waters where they
are partly embedded in the mud or sand. Their known range is
from 2 to over 2,400 fathoms. The fossil species described prob-
ably lived in moderate depths.

LITERATURE: Papers on the marine Tertiaries elsewhere cited.

Family DENTALIID Gray.
I. DenTALIUM Linnzus.

Shell tusk-like, tubular, curved and regularly tapering, with
circular cross-section and open ends; surface with strong longi-
tudinal ribs (sexs. strict.) or with longitudinal striz or smooth;
apex entire or with notch or slit of greater or less length. Ordo-
vicic >—Recent.

1. D. (Levidentalium) martini Whitfield. (Fig. 794.)
Devonic.

SCAPHOPODA—DENTALIIDA.. 579

Smooth, rather rapidly expanding, moderately curved ; section
circular, growth lines arching forward on concave side.
Columbus limestone of Ohio.
2. D. (Levidentalium) pauperculum M. & H. (Fig. 795, 2.)
Cretacic.
Minute, smooth, gently curved, gradually tapering, section cir-
cular, shell thick, lines of growth oblique.
Pierre and Fox Hills of upper Missouri river region.
3. D. gracile Hall and Meek. (Fig. 795, 4-d.) Cretacic.
Very gently tapering and slightly curved, section nearly or
quite circular; apical end smooth; fine round longitudinal lines

FIG. 794. Fic. 795. a, Dentalium pauperculum, Fic. 796.

Dentalium natural size; b-d, Dentalium gracile; 3, Dentalium
martini. part of shell; c, enlargement of surface ; stramineum.
(After Whit- , section of large end, (After Meek.) (After Gabb. )

field. )
over most of shell, increased by intercalation and becoming obsolete
toward larger end.
Pierre formation of Dakota and the Yellowstone river region.
4. D. stramineum Gabb. (Fig. 796.) Cretacic.
Rather rapidly tapering, slightly curved, and with numerous
longitudinal lines or ridges.
Upper Cretacic of California.
5. D. (Antalis) cooperi Gabb. (Fig. 797.) Cretacic.
Very gently curved, moderately tapering, surface with numerous
fine parallel striz separated by depressed lines.
Upper Cretacic of California and Sucia Island.
6. D. subarcuatum Conrad. Cretacic.
Slender, very gently arcuate, tapering in 47 mm. from 5 mm.

580 NORTH AMERICAN INDEX FOSSILS.

to 2 mm. Internal molds smooth or with faint lines, and with
rounded ridge on cancave side ; shell surface with about 12 angu-
lar longitudinal costz and fine annular strie.

Ripleyan of New Jersey and Alabama.

7. D. nanaimoense Meek. Cretacic.
Distinguished from JD. gracile by its thinner shell and more
slender form, and less distinct lines of growth.
Nanaimo of Vancouver and Sucia Islands.

8. D. (Graptacme) mediaviense Harris. (Fig. 798.) — Eocenic.
Rapidly tapering, curved near small end, smooth near large

Fic. 797. Dentalium cooperi, with Fic. 798. a, 6, Dentalium mediaviense; c,
enlargement. (After Gabb. ) Cadulus turgidus (see right). (After Harris. )

end; elsewhere striated with fine sharp alternating longitudinal
strize ; faint concentric annulations occur; shell thick except near
larger end. Maximum diameter 3 inch.

Midwayan of Alabama and Mississippi.

9. D. (Graptacme) minutistriatum Gabb. Eocenic.
Smaller, and less rapidly tapering than preceding; curvature
gentle, with minute, regular, non-alternating strie.
Claibornian of Texas — Nanjemoy of Maryland.

10. D. thalloides Conrad. (Fig. 799.) | Eocenic.
Curved most strongly near small end, rapidly tapering ; coste
strong, alternating, or of three sizes.

ee lL ee eee eee

SCAPHOPODA—SIPHONODENTALIIDA. 581

Claibornian of Alabama, Louisiana and Mississippi. Abundant.

11. D. attenuatum Say. (Fig. 800, a.) Miocenic.
Arcuate and rapidly tapering; surface with 12 to 16 rounded

Fic. 799. Dentalium thalloides. Fic. 800. a, Dentalium attenuatum ; 6,
(After Conrad.) c, D. caduloide, (Md. Surv.)

ridges separated by broader interspaces, and obsolete towards
narrow end.
Chesapeakean of Maryland.
12. D. (Laevidentalium) caduloide Dall. (Fig. 800, 4, c.)
Miocenic.
Smooth, regularly tapering and more gently curved than the
preceding. Section circular.
Chesapeakean of Maryland.

Family ST7PHONODENTALIIDZ Simroth.
HH. 'CapuLos: Phil.
Differs from Dentalium in being swollen near the middle and
tapering toward each end. Cretacic—Recent.
13. C. turgidus Meyer. (Fig. 798, c.) Eocenic.
Rapidly increasing for about two thirds of length and then more

rapidly decreasing. Section circular.
Midwayan of Alabama.

14. C. abruptus M.& A. (Fig. 801, a.) Eocenic.

582 NORTH AMERICAN INDEX FOSSILS.

Rather large, somewhat depressed, inflation less pronounced
than in preceding species and nearer to larger end, suddenly de-
creasing.

Chickasawan of Alabama, Nanjemoy and
Aquia of Maryland, etc.

15. C. thallus (Conrad). (Fig. 801, 2.)
Miocenic.

Slightly curved, smooth and polished,
swelling greatest below middle, regularly
tapering in both directions, then more rapid-
ly to small end.

Chesapeakean of Maryland, Virginia,
later Miocenic of North and South Carolina
and Alum Bluff, Florida.

Fic. Sor. a, Cadulus ab-
ruptus ; 6, C. thallus. (Both
after Md. Surv.)

Class Gastropoda (Snails).

The gastropods or snails are marine, fresh-water or terrestrial
mollusks, with a well-developed head which usually bears tentacles,
eyes, ears and a mouth furnished with a file-like lingual ribbon
or radula. Ventrally the animal is provided with a muscular
“‘foot’’ which is generally a broad expansion and sometimes very
large but may be variously modified. The visceral organs are gen-
erally protected by a calcareous (rarely horny) shell secreted by
a mantle. The shell may be conical or saucer-shaped, but is
generally coiled into a spiral, either right-handed or left-handed,
the former being the more common type. In all cases the shell
may be considered a gradually widening cone, which is generally
coiled around an imaginary axis which is often hollow.

The shell begins with the minute embryonic whorls of the proto-
conch, which in many types is quite distinct from the rest of the
shell. From this portion, which forms the apex of the sfzre, the
coils or whorls of the shell gradually increase in size. Normally
the whorls are circular or elliptical in section, but from compres-
sion and other causes a variety of forms results. The spire may
be high or low, broad or slender according to the mode of enroll-
ment, the apical angle varying accordingly. The whorls may rest
loosely upon one another or embrace to a greater or less extent up
to the middle or amditus, or even beyond, so that the earlier whorls
may be largely or wholly covered by the later ones. When an

MOLLUSCA—GASTROPODA. } 583

angulation occurs, the space between it and the suture above it
constitutes the shoulder. The shoulder angle may be simple or
keeled, or furnished with nodes or spines.

The primitive ornamentation of the shell consists of revolving
ridges or sfzrals, and of transverse folds or vzbs. Primary spirals
appear in regular succession on either side of the first primary,
which generally becomes the shoulder angle if angulation occurs.
_ Secondary spirals appear by intercalation between the primary
ones, and generally are absent in the young shell, except in some
highly accelerated types. Tertiary spirals are intercalated between
the preceding groups in more specialized species. Ribs are regular
transverse foldings of the shell generally extending from suture to
suture. They are usually spaced uniformly and crossed by the
spirals. In specialized types when a shoulder angle is formed,
they become concentrated as zodes upon this angle, disappearing
from the shoulder above and the body below. Spines may replace
the nodes in later stages. They form as notches in the margin of
the shell and are subsequently abandoned, often remaining open
in front. Irregular spines may also arise on various parts of the
surface of the shell (see Platyceras). When a row of spines is formed
at the edge or outer lip of the shell — this sometimes remains
behind as a varix (Murex). Varices may also be formed by simple
expansion of the outer lip, and a subsequent resumption of growth
from the base of the expansion. These simple varices may project
from the shell (Sca/a) or be reflected backwards (Harpa). Periodic
enlargements of ribs (Murex, Cerithium) are not to be classed as
varices.

The aperture or peristome of the shell may be simple or variously
modified. An outer and an inner (columellar) “f are generally rec-
ognized. These may be continuous with each other, or may be
divided below by an anterior notch. This, in some types (/usus,
etc.) is drawn out into an anterior canal, of greater or less length.
An upper or fosterior notch is present in certain (chiefly old age)
types, and this may result in the formation of a ridge or shelf
next to the suture (C/aviithes). An outer (lateral) emargination
or notch, sometimes prolonged into a s#¢ occurs in certain types
(Pleurotomide, Pleurotomaride, Bellerophontide, etc.), and the
progressive closing of this slit may give rise to a definitely marked
slit band. In some cases the slit is abandoned and left as a hole

584 NORTH AMERICAN: INDEX FOSSILS.

(fissuridea), or by periodic renewal as a succession of holes
(Trematonotus). The outer emargination is often only indicated
by the reflected course of the dines of growth on the shell. On
the inside of the outer lip various ridges or plications called re
are sometimes found, and these occasionally may be strong and
tooth-like (Merinea). Similar ridges or columellar plice or folds
are more often found on the inner lip, next to the columella or
central spiral twist. These may be oblique or normal to the
axis of coiling (horizontal), few or numerous, readily seen, or far
within the shell so as to be invisible except in broken shells.
When the axis of coiling is hollow (perforate spire) the opening at
the base constitutes the wmdilicus. This varies greatly in size,
and may be wholly or in part covered by an expansion or callus
of the inner lip (Vatica).*

Most modern shells are covered by a horny smooth or hairy
epidermis or periostracum, which hides the (often brilliant) color
markings of the surface. This, as well as the coloration, is rarely
preserved in fossil shells.

The apertural end of the gastropod shell is the azterior end,
the apex of the spire the posterior. Most authors figure the shells
with the apex of the spire uppermost. French authors generally
figure them with the anterior end uppermost. The aperture is
often closed by a horny or calcareous operculum, of very variable
form in the different groups. It is secreted by and attached to
the foot of the animal.

LITERATURE.
A. Paleozoic Species.

1847-1879. Hall, James. Paleontology of New York. Vols. L,
iL and lil, and Vol. V.,.Ft. 11.

1861. Billings, E. Paleozoic Fossils. Vols. I. and II. .

I908. Raymond, P. E. The Gastropods of the Chazy Formation.
Annals of the Carnegie Museum, Vol. IV., nos. 3 and 4.

Ig08. Ulrich, E. O., and Scofield. The Lower Silurian Gastro-
poda of Minnesota. Minn. Geol. Surv. Paleontology, Pt. II.
(This is in many respects the most important work on American
Palzeozoic Gastropods. )
For descriptions of American Palzeozoic species, see further: The

.

* For further discussion of these characters see A. W. Grabau, ‘‘ Studies of Gastro-
poda, I. and III.’’ (Am. Nat,, XXXVI., No. 432, and XLI., No. 490.)

MOLLUSCA—GASTROPODA. 585

publications of the Canadian Survey, especially ‘‘ Contributions to Cana-
dian Paleontology ’’ and ‘‘ Canadian Organic Remains’’ ; various re-
cent publications of the New York State Survey, especially memoirs 5,
6 and gq; Vol. 3 of the Palzontology of New Jersey ; the two volumes
on the Paleontology of Ohio; and Vol. VII. of the Geology; the
Paleontological volumes of the Illinois Survey; the early volumes of
the Iowa Survey; certain volumes of the Indiana Survey (especially
the 28th); Kentucky Fossil Shells by Nettelroth, 1889 ; certain publi-
cations of the United States Geological Survey (especially Monograph
8); Vol. to of the Powell and Vol. 4 of the Wheeler (100th meridian )
surveys ; and professional papers nos. 16, 58, and numerous papers in
periodicals by Beede, Billings, Girty, Hall, Meek and Worthen, Salter,
Ulrich, Whiteaves, Whitfield and others.

B. Mesozotc Species.

1886. Whitfield, R. P. Gastropoda and Cephalopoda of the Raritan
Clays and Green Sands of New Jersey. Pal. N. J., Vol. 1, and
Monograph U. S. Geol. Survey, Vol. 9.

Also the following publications : Canadian Geological Survey, Meso-
zoic Fossils, and Contribution to Canadian Palzontology ; New Jersey
Geol. Surv. Paleontology, Vol. IV.; Palzontology of California, Vols.
1 and 2; Geology and Paleontology of the Black Hills, and the publi-
cations of the several United States Geological and Geographical Sur-
veys, especially the Wheeler Survey of the tooth meridian, Vol. 4,
1877; the Hayden Surveys of the Territory, Vol 9; 3d annual report
of the U. S. Geol. Survey under Powell; Bulletins 106, 133; the
Boletin de Instituto Geologico de Mexico, especially No. 24, and various,
papers by Conrad, Cragin, Gabb, Hill, Roemer, Stanton, White and
Whitfield.

C. Cenozoic Spectes.

1832-38. Conrad. Fossil Shells of the Tertiary Formation a Fossil
Shells of the Medial Tertiary.

1833. Lea. Contributions to Geology.

1890. Gregorio, A. de. Monographie Eodc. Alabama. Annales de
Geologie et de Paléontologie de Gregorio.

1893. Cossmann, M. Notes Complémentaires sur la Faune Eocé-
nique de 1’Alabama. Ann. de Geol. & de Pal. —Gregorio. No. 12.

1895-1899. Harris, G. D. The Midway Stage and the Lignitic
peage, Ft. It. Bull.. Amer..Pal., Vols. I. and III.

1890-1892. Dall, W.H. Tertiary Faunaof Florida. Pts. I. and II.
Transactions of the Wagner Free Institute of Science, Vol, 3, 1890-

92.

586 NORTH AMERICAN INDEX FOSSILS.

1900-1906. Clark, W. B., and Martin, W.G. Eocene, Miocene
and Pliocene Gastropods of Maryland in Geological Survey of Mary-
land.

1857. Toumey, M., and Holmes, F. S. Pliocene Fossils of
South Carolina.

1860. Holmes. F. S._ Post-Pliocene Fossils of South Carolina.

1903. Arnold, Ralph. [Illustrations of Tertiary Gastropods, etc., of
California, in Bulletins U. S. Geological Survey, Nos. 321, 322; and
Paleontology and Stratigraphy of the Marine Pliocene and Pleisto-
cene of San Pedro, Cal. Memoirs Cal. Acad. Sci., Vol. III., 1903.
Also the Paleontological volumes of the California Survey, the Sur-

veys of Texas, Alabama and Georgia.

Besides the above, see papers by Aldrich, Arnold, Conrad, Dall,

Emmons, Gabb, Harris, Heilprin, Johnson, Lea, Maury, Meyer and

others.

ARTIFICIAL KEY TO THE GENERA,

A, Shell patelliform or conical, often curved, but not coiled, or with only a minute.

spiral protoconch which is not generally preserved.,..........ccecescoesseereeees Ki;

1.) Shellewith a slitior perforations... ..4.505.005.0 uscie sexed Znccnns silvasdppunsasan seen I.
E. GSUit WAAR UI ood bewngnuanapasle sek si cdastel ons nen aw senuy XCVIII. Zmarginula.

1. Without slit, but with apical perforation.. ..............64 XCIX. Fissuridea.

1. Withoat ‘Slit Gr petforalion : foci cec ss aes sons osisoe bes ondenn seas ie dentes ae eee em
2. Aperture ovoid, narrower at one end, sometimes but slightly so........... ei

*, Beak nearest to, and curved toward, narrow end...........ccesee2 seeeee a.

a. Surface with growth lines only or with coarse plications.
I. Zriblidium.
a. Surface with fine radiating stric. .....00c.:60.-s0<% II. Helcionopsis.
*, Beak curved to broad end... 20....ccscss.500careaecueadsuseessssaesaen b.
b. High and conical; muscle scars in disconnected pairs,
III. Aipseloconus,
b. Rather low, patelliform ; muscle scars a continuous band ; aper-

ture sometimes almost oval............sceeeeeees IV. Archinacella.

2. Aperture circular or oval, form symmetrical ........,....0sss0ssssesseaseeeaue ini
**, Surface sculpture of concentric wrinkles, radiating striz when pres-

Ont Very MME sco. veissdaanswee ddd citehatecevellsidesas¥ aces dee ean Cc

c. Apex subcentral, wrinkles uniform, continuous aigane shell.

V. Paleacmea.
c. Apex submarginal, wrinkles strongest away from beak.

VI. Helctonella,

#*, Surface sculpture radial or absent ..........:3 seecssess sosessecumoneee aan d.
A: AOR ReTLON AES ca. 5c cewcees ecanane~dvaticnna@asece XCIX, Fissuridea.

d.” Apex Net. pertorated .. 021k .usut fsdvonssesenees 1 pa ce Ged cee Il.

11. Surface plicate at least in lower part..............00-seeeeees aa.

aa. Apex with minute coiled protoconch...............+000 T-

{. Cup-shaped platform on the interior.

;

:

CX. Crucibulum.

MOLLUSCA—GASTROPODA. 587

f. Without interior platform...........CVII. Capulus.
ad... APEX POUNted. 7. J. 2c oleae wethevass cow tacck edesee coemopmame TT:
Pfs: Apex straight 25. cassettes LXXVII. Jgoceras.
tt. Apex curved but not enrolled.

LXXVI. Orthonychia.
II, Surface striate or faintly plicate, rarely smooth............ bb.
bh Beak! mohumcitved sys...) 0 toowsats sss vances Medeaseees TTT:
ttt. Beak subcentral, muscle scars forming a circle at
about mid-height............-..... VIL. Scenella.
ttt. Beak excentric, striz fine or absent, muscle scars

horseshoe-shaped, open in front.
VIII. Lepetopsis.

bb. Beaks strongly incurved.................. CVII. Capulus.

**, Surface smooth or with few coarse and faint plicze..................000 e.
e. Horseshoe-shaped muscle scar open in front..............0s0e000s 22.

22. Beak .scearcély incurved... j.ycazccevewssop-cones VIII. Lepetopsis.
22. Beak strongly incurved but scarcely enrolled, surface often

RAMI hte ak Ciopoau vm ddone da soenttesa ae .CVII, Capulus.

e. Horseshoe-shaped scar open behind........... CCVII. Antsomyon.

e. Muscle scar faint or absent, dorsum often carinate.
LXXV. Paleocapulus.

2. Aperture circular or oval, form unsymmetrical............-ccsesconssseseses ra
***, Low, patelliform, surface often with oblique angulation and posterior
RPUMNEMUANY Sb he ashe et vans one eoag aa kct iuacteeteeetets CCVI. Hercynella.

***, High, curved, surface smooth or coarsely plicate.
LXXVI. Orthonychia.

MPP EROLS DALY CLOSER oho. acm nds SeridengeuPeecacinaavasavesecepesnssvensuy adiasie sore
4*. Closure by a thin platform, beak marginal, curved laterally.
CIX. Crepidula.

4*. Closure by the thick, flattened lower portion of the body whorl.
XCVII. Velatella.

B. Shell nautiliform, coiled in a single plane throughout, or apparently so........... Ti,
II. All whorls in same plane, with median notch or reéntrant in outer lip
NEN MINNIS a PAE ira aide Hak ay SeMubiverdick suave nodnnsasaWe duane ahs aereh 4.

4. Shell with rounded dorsum, often modified by elevated or sunken fold

DSCC T I Cine SUM Ne Seiciains ts ona iis naka edd ndebu tine ka@ewmnaes 5*.

eee With large open TMbIiCUs,...i..4..<2s2<0000 os cs0d000 Bets nenelarsousateven f.

f. Aperture abruptly lagna es trumpet-like, volutions scarcely em-

EWU CHA ce ues athnts aaeaisick nadia ad Remade Med las te bewey aalg ne 33

33. With a long narrow dorsal slit, closed at aperture.
XV. Salpingostoma.

33. With slit replaced by a series of elongate openings.
XVI. Zrematonotus.

f, Aperture not expanded into trumpet mouth...............seceeeeees 44.
44;_Lip, with, sinws:but no Slit Band... ccsuvescisexceuvessweesoaenss cc

cc. Dorso-ventrally compressed whorls, sinus shallow and

ENECHAIAS, gslasu skins xinks extort oy sek ntio ose nwacnaty X. Owenella.

cc. Rounded whorls, umbilicus mostly small, sinus deep.
XI. Protowarthia.
44. Lip with well-marked slit and slit-band..................48. dd.
dd. Surface with oblique revolving lines...XIV. Bucania.

588 NORTH AMERICAN INDEX FOSSILS.

Algh-) AUTRE SMIOOUN £4 cs es sarindas cos osc XIX. Bellerophon.

BY, Umlbjliqus minute oniabsents os, Jain ices cteandes sia davan Cokwasen sock sa aeeen g.
ei Apertere abriotly expanming io). ad.ccc.savecan casos anerepanneneneee 55:

55. Lip -emmuate, Morslit-bandss,. icccedas seavecoes XXII. Promatis.

55. With narrow strong slit-band....... XXIII. Phragmostoma.

g. Aperture not abruptly, but regularly expanding .................. 66.

66. Aperture with central emargination and slit-band, often on

median Mees... Weenies ta vocde candeynnaiedaee cee ee.

ee. Inner lip expanded as a flat septum.

; XXIV. Carinaropsis.
ee. Inner lip callous, but not expanded into septum.,....4f.
4ft. Surface with growth lines only; umbilicus small
OP QDSOIN tied inn cevelss nas spa oes XIX. Lellerophon.
4f. Surface with revolving as wellas growth lines. ...1”,

1”, Revolving striz uniform over entire shell.
XXI. Bucanopsts.
1”. Strize in form of parallel ridges on inner lip

and over part of preceding volution.
XX. Luphemus.
66. Aperture without slit-band, but deeply bilobed; surface
finely spiraled (or smooth), umbilicus mostly small.

XI. Protowarthia.
4. Shell with rounded dorsum, modified by revolving keels or folds or by

DOUESS ica certnncanina gyn tas ned asinctnn oki dqe eden eden leant ee 6*
6*. With revolving. folds only. iis sccsi'es oisicncinewndcateusey oF00 ese nn h.
h. With median fold, bearing short slit, and one or more lateral
HOLES Os CACI SIDE soiai.04< Hoes uae oslactquesstecaeaons XII. Zetranota.
h. Dorsum deeply trilobed ; aperture sinuate...... XII. Bucaniella.
6*, ae HOES OF {LaNSVETSE: TUDE. vo secc vie saicate's -s.aaccres vackbe i olan seen is
mabilious: Pare). jctth uit ccaecieact saa cote ceterenees XXV. Porcellia.
; Umbilieus ‘snaal lor. absent: jc) cic.raucracenoestee XIX. Bellerophon.
4. Shell with sharp dorsal keel, strongly compressed laterally .............. 7h)

7*, Whorls more or less triangular, 10: 00. )..56 5 oi0c2. < cee ve uaara’ ce ‘

j. Sides angular, generally with ribs, slit short or absent. .

IX. Cyrtolites.

j. Sides rounded, strong lamellose growth-lines; slit long.

XVIIL. Phragmolites.

7*, Sides flatly rounded, shell disciform, strongly compressed keel

SBE idiariahaincairtistcunbsiasnuneiinnereenes taulrscen nana emee XVII. Oxydiscus.

II. Inner whorls forming low spiral, outer whorl in same plane.................008: 5.

5. With median notch and slit-band ; shell marked by nodes or ribs.

XXV. Porcellia.

5. Without median notch or slit, surface smooth............ CCXIV. Planordzs.
II. All whorls very nearly in same€ plane... ...00 5.22. ..ccccecesse0000<s0+00yeehee 6.
6.-Rapidly- enlarging ; ‘shell minute). so.) 4s esseases conces CCXX. Pelagiella.
bo, Gradwally @nlarome fe canti se cass ont catn ee cevvendiansnneeete CCXIV, Planorois.

C. Shells naticoid or varying from flat to oval, with round whorls showing rarely a
faint angulation and forming a moderate sometimes flat spiral. Final

(sometimes all) whorls’ may be loose-coiled...........s0«»s00s«aussaeqnmiias ui. #

III. Surface without ribs or spirals, but growth-lines may be prominent........... re
7. shell umbilveated oi ii0ssidesecn tates veces co yas siacsecnd~ sete wcote anges cane 8*

MOLLUSCA—GASTROPODA. 589

8*. Whorls round, resting one against the other without impression ; last

part oftemlpase-comleds 1...) 2.25 a che ian cbbcateecctne sc nmemaces k.

k. Small, umbilicus moderate ................... XLIX. Straparollina.

k. Turbinate to discoid, umbilicus large.............. L. Straparollus.

le; Minute, wabilicts minate 22, i). 62.5065 sleerssven ven LXVII. Cyclora.

k. Minute, turbinate or discoidal umbilicus moderate (fresh-water
EPPO )e dicids Vetenwer es Maen ee Nilabiol en nctarssoa} CCXIV. Planorbis.

8*. Whorls rounded, not in contact with each other ................ceseeee 1.
L, Witheut notth orikeels aio ccc aee erent LI. Phanerotinus.

1. Notch or keel faintly developed... .......... LIX. Lecyliomphalus.

8*. Whorls round except for impressed zone at the point of contact. m.
m. Spire sunken into a flat surface or below it
77. Whorls flattened dorso-ventrally, umbilical margin notched.
CVI. Solarium.
77. Whorls not flattened, somewhat angular..................... fi.
ff. Many whorled, smooth............... CCXIV. Planoris.
ff. Few-whorled with lamellose growth lines.
CCXII1. Vorticifex,

(ri OPES OU BUM GHy 5 iF lon aati veehGee Wotace sta Tecss.cuachimoute eagle 88.
So.) Spite bows minbilicus latge sis... ccs eclacessnetzontncn sedate gg.
gg. Whorls rapidly enlarging, umbilicus open or covered

Diy TERRI oh Sa unpesivden ast eats XCIII. Zeznostomata.

gg. Whorls numerous, slowly enlarging, umbilicus open
only in internal mold......... LXVI, Pycnomphalus.

S8.: Spite moderately Wid, 2a. fi seii.cisedSalssnake sadveoee bh.
hh. Whorls strongly embracing ; iemabifiens large, often

CO OEE coche Bisa on us geenan hen net ee es nan etete eres ST-

5t. Lip interrupted at the body-whorl; umbilicus

large and deep...... CCXVIII. Archeozonites.

5t. Lip continuous, not interrupted at the body whorl.

2s

2/* Umbilicus large and round,.........0.c04.. ar’.

a’’. Whorls few, round, rapidly enlarging,
umbilicus often covered by callus.
CXIII. Natica.
a/’, Whorls less rapidly enlarging, with a
depressed sutural band, and generally
an angulation around the umbilicus.
CXIV. Gyrodes.
2’/’. Umbilicus small, whorls scarcely impressed.
D*.
b/’. Small, smooth........ CXVIII. Valvata.
LXVII. Cyclora.
b’’, Large, with strong growth lamelle.
LXXI. olopea.
hh. Whorls moderately embracing or barely in contact or
even free. Internal molds of many naticoid shells
- which may be non-umbilicate when perfect or may
be strongly embracing, or may have spirals or even

ribs.
NECN NOGLOUL TMOMLCUIN, 5, devs s codabye sa aeulis Gea rsa vin rvaredadssaliasdtosdssasens or.

590 NORTH AMERICAN INDEX FOSSILS.

oF Whorls few, tapidly ‘enlarrine ils), 00) 5c csevnvinhanae dcdancaboeecokeadncteien ni,
n. More or less globular except when uncoiling....:.............00. 99.

go. Inner lip thickened ‘by callus. isistie se cci ss. selec tues eseee ii.

ii. Inner lip flattened, callus smooth or transversely striate;

aperturcioval scoop ik. cnestaneeap LXVIII. Waticopsis.

ii. Inner lip not flattened, callus smooth, aperture semi-

Cie AT GONOVAL oe scsi dissnenhcwnren cess CXIII. WNatica.

ii. Callus with straight, commonly denticulate border.
XCVI, Nerita.
99. Tnuer lip not thickened: by callus):2i:.023).<c002 s2enckeereee jJ-
jj. Lower lip twisted and grooved, aperture round.
LXXII. Strophostylus.
jj. Inner lip with columellar fold, aperture elongate.
LXXXIX. Spherodoma,
n. More or less conical, with base flat, and last whorl extended so

as to: form flatsperiphieny. . .. te. e.sscccer weihaseen CVIII. Calyptrea.
n. Elongate, ‘body whorl extended s,s... i. ccc ctaeee ee 000,
ooo. Coiling dextral or right-handed .,.....;,..:...0ccassaestaeeeeeee kk.

kk. Shell thin, body whorl moderate......CCXI. Zimnea.
kk, Shell thick, body whorl very large.
CXCIX. Acteonia.

ooo. Coiling left-handed or sinistral.............. CCXII. Physa.

9*. Whorls regularly and gradually enlarging.............10s<sec0sescheeeeene oO.
o. Spire low,. columella not’ plicate: ........%...2..0ceasesseseeueeee Fig:

TEES Close-cotled o 5. vegaut lanaks sathigee toda es sot oaqveodeetiges eee 11.

as Rees. Ss Soak Le honns eaelan dk aerean cement en 6f.

6+. Whorls few, aperture circular.
LXXIII. Diaphorostoma.
6+. Whorls many, aperture with umbilical extension.
LXVI. Pycnomphalus.
ll. Medium sized, aperture interrupted at body whorl;

outer lip frequently with varix....... CCXIX. Helix.

T).* NEI GGe rre ieak ie Se ata ew ngs close se ee The
7+. Vertically compressed......... LXV. Anomphatus.

7+. Last whorl ventricose ...... LXVA. Protospiralis.

111, Last portion not coiled; aperture circular or variable.
LXXIV. Platyceras.

©, Spite low, columella with plications....:........:.:ccs:sn«seeanemae 222.
222. Shell broadest in upper part, often with distinct shoulder
BASIE: 5 5 ch yee ivassaasdegntes sadecre sta aeee enn mm

mm: Surface smooth ../.. ois. .0ssesescsse CCVIII. Melampus.

mm. Surface with wrinkles or faint ribs in upper part.

CCIX. Rhytophorus.
222. Shell broadest in middle or below, no shoulder.

CCX, Alexia
o. Spire spoderately bighy..vsciscedesass, +s as 0ssc0sseecesnen ee 333-
333. Aperture circular or subcircular,...........0..00s01sseeneee nn,
nn. Aperture generally more than half the height of shell.
LXXI. Holopea.
nn. Aperture generally less than half the height of shell.
St.

MOLLUSCA—GASTROPODA. 591

8}. Inner lip thickened, shell thick.

CXX. Campeloma.
8t. Inner lip not thickened, shell moderate.

CXIX. Viviparous.

333«: Aperture: elongates. jee csi uS Rates eb siecenndnaeeateauneeen 00.
oo. Generally with distinct sutural shelf and smooth col-
Mane 5 hate peste on ant esten es ge CXV. Amauropsis.

oo. Without sutural shelf and with columellar fold.
LXXXIX. Spherodoma.
III. Surface with transverse striz or ribs; or with spirals or with both........... 8.
8. Shell umbilicated, umbilicus covered by callus of inner lip.............. 10%,
10o*, Spirals or revolving plications most prominent, but not producing
PERCE RHOWIGEE “SA ROTE Sf Mei 5 aca sdns a soerGtac’nialiaabacnasoadeionne p-
p- Spirals or plications not uniformly distributed, shell partly non-
OM. ec se etiteawi Raman Nel See gh hed ovoinee huis LXXIV. Platyceras.
p- Spirals more or less uniform, shell mostly or wholly coiled
Pico ROS 3 < .1te55 <9 cats cpu eencah Don peapaen de asa toaeexacs 444.
444. Whorls and aperture round, generally only touching
Without embraces, ci.j saad ivan ese sk Gasoolianeneetans pp-
pp- Spirals much stronger than transverse sculpture.
LXII. Poleumita.
pp- Spiral sculpture not strong...........XCII. Margarita.
444. Whorls more or less embracing, aperture round or irreg-

Gs Sotely StaPtaCin Sag. c.sisarsnases oo sviecsvenecndareavesaay of.
gt. Whorls somewhat subangular, spirals smooth.
XC, Gibbula.
9f. Whorls round, spirals regular, fine.
CXI. Sigaretus.
qas. Moderately. embracing.) .isistecdigevessiseel s \ccssdens Iof.
Iot. Spirals, strongly nodose, spire leased.
LXIX. Trachydomia.
of. Be spirals, not nodose, spire vertically com.

Lic as Ip memer er nee ae err e XCIV. Adeorbis.

10*. Spirals faint or absent, transverse striz prominent................+. q.
q. Shell round-whorled, or more rarely angulated or even com-
PERU, Sse dda snctiaun rst ccehadspacepacscads Cepekemmeeogens 555-

555. Transverse striz straight and over entire shell.
LXXIX. Callonema,
555. Striz only on upper portion of shell,.... LXXX. Jsonema.

8. Shell not umbilicated (rarely with faint umbilical indentation)......... ou.
11*, Spirals pronounced, transverse sculpture weak or absent............ i

r. Lip discontinuous, whorls slightly impressed, spire acute to rect-

Ce | SMP Ee Peer Peet eee Pee PAE, Cie SrueNer. CME De nee ™ 666.

666. Spirals numerous, nearly or quite impressed.
LXIII. Cyclonema.
666. Scitets few, not ws same size, one or more often beaded.
XCI. Calliostoma.
r. Lip continuous, outer lip sometimes reflected.............0.0000 777:
777. Outer lip reflected and thickened. Columellar plications
LPPEBSIE he. sea vadertwveas sesrdnidn rede og acy dando} svesenesicne Ny

592 NORTH AMERICAN INDEX FOSSILS.

rr. Body whorl inflated, aperture forming more than half

the Tenoth of the shell: iiss cicsctacscansss CC. Cinulia.
rr. Body whorl not inflated, aperture less than half the
STEMS 117-07 ea ee Lee eee ae CCI. Ringicula.

777. Outer lip neither reflected nor thickened, without col-

umellar plications, sometimes with small teeth or tu-

Dercles Ma PeriSlamMeAss ...sebl.cccese dan aecee XC. Gibbula.

11*, Spirals and transverse sculpture equally developed or nearly so... s.
s. Inner lip thickened with angular emargination in middle.

XCV. Nerztopsis.

s. «dinner lip not thtekened » smooth. ic0Ni lili. sceaverun ented 888.

888. Vertical sculpture oblique, rib-like folds.

CXII. Vanikoropsis.

888, Vertical sculpture interrupted transversely so as to produce

only rows of tubercles.............. LXIX. Zrachydomia.

11*, Transverse sculpture or ribs alone present ; spire low, shell narrow-

ing anterior-wards, ribs only near suture...CCIX. Rhytophorus.

15*,: Faint spisals/alone presentiis). fo2 405 i2s adelaasacs CXX. Campeloma.
IVY...Surface with nodes’ or: spinesiasasy hoi iyabs Woe ac chp daetbaievvcwae+ see des eee 9.
gi: Shell non-umbilteated spc dan log Vas Sots A Gs vege ace dw de usioda ane ee 12*,

12*. Whorls few, rapidly and regularly enlarging, surface nodose.
. LXIX. Trachydomia.
12*. Whorls few, forming irregular spiral which is sometimes conical,
base flat, formed by extended last whorl; surface irregularly
STUBS nes ew ac eet Roe evo « loons wan aseae’ CVIII. Calyptrea.
g. Shell umbilicated when not wholly uncoiled...............sceccsceccesevecs 13*;
13*. Spines irregular, tubular, last whorls mostly uncoiling.
LXXIV. Platyceras.
D. Shell in general form like the preceding group, but with the roundness of the
whorls modified by one or several strong angulations, often flattened; no
mharginahmoetoly OY Slit |Z 20. fact entice sd wae been¥sisenn sie seed pehnbevenan nein IV.
PV, Shell umabtlicatod si. 3606 3 jesus eadeavsewiny es eek sve diana. a5 ites pect eon eae enn 10.
10. Angulations few (3-5), with all or most of the spaces between them flat-
FENNEC: OF COMMAVE <5 .ci-oxteeeemt pat cave ob bees ntan dae LXIV. Zvrochonema.
Io. Angulation only on upper surface or around umbilicus or both........ es
14*, Naticoid, high-spired with flattened shoulder and oblique lip. _
. LXI. Omphalotrochus.
14*, Spire low or flat, the upper carina in center of whorl.
LVII. Euomphalus.
14*. Spire low, embracing to marginal angulation, last whorl free.
LVIII. Calaurops.
14*. All whorls disconnected, carina on upper surface; well-preserved

specimens always show apertural notch.....LIX. Zccylomphalus.

14*. Spire flat, coil left-handed (sinistral), angulations on periphery and

URAAP TOU, urea RD Saeed Ak eGdaee scl Nese snes lope ke LX. Maclurea.

EV. -oNon-pmabilica ted 0... ics scedicione ameBenmitirn a ¥5is/acwe Slleeaienicna swe actions) stan eeeannnn i:

11. With strong peripheral keel alone modifying the roundness of whorl in
adult, and with strong oblique folds on upper part of whorl.
LXX. Zurbonopsts.
E. Shells trochiform, spire more or less continuously conical, basal portion abruptly
deflected and often flattened. No apertural notch. ...............csceeeeeeseees V.

MOLLUSCA—GASTROPODA. 593

V. Peripheral margin more or less strongly angulated but not sharp; surface with:

regular ornamenitationed aii ieegst KN cali acs is ee iz:

Fay Nton-unbilicated, 2,525 12. bees eee Se aes OR tent XCI. Calliostoma.
vie Usabilicatedd;, 2:0 s).. vis iaseey Rca b cane tdaea Coates tonan ehdenant ee eee 15*..
15*. Umbilicus with distinct and notched spiral.......... CVI, Solarium.

15*. Umbilicus without markedly notched margin or spiral.
XCIA,. Eutrochus.
V. Periphery sharply angular, often produced, surface frequently modified by

mementation of foreign substamces:......iccssddecasceecscenss CXVII. Xenophora.

F, Shell turreted, mostly high-spired, with round or more rarely flattened and angulated
whorls, and entire aperture without peripheral notch or slit.. .............. Vi.
RN EMETEMN MS 55/20 sSidisig iawn peu Salute Uedja de detan Deayed a Ve baled Peed en «Svvenied vas 13:

oe surtace smooth, except for lines of Prowth. .........s.0..sscdecescnccoseness 16",

16*, Whorls flattened, sutures scarcely or not at all impressed............ ft:

t... Golumnellar lip with tooth to. .cac lid ceas caneus CIV. Odostomia.

t. Columellar lip with several oblique folds.

LXXXVIII. Soleniscus.
ce commeblene Lig emmmoting Nise ts Aiea os fan e eee eee Sakae one ven 999.
ggg. Dextral, ‘aperturé elonpate 7 4...¢.0.....00 crete danke aceaeses SS:

ss. Inner lip only visible in lower half.
LXXXVI. Meekospiria.
Son Romer Teer Complelel es fidwsiend clan ne seas cheese eter «ated EIT;
11t. Shell smooth and lustrous, protoconch dextral.
C. Eulima.
11f. Shell thick, apex generally wanting, not dextral.
CXXX. Goniobasis.
996. Sinistral, aperture OVOId...1..52....0500- 20.00 CCXIL:. | Prysa:
16*, Whorls rounded, sutures more or less deeply impressed.............. u.
u. Body whorl long, one half or more of length of shell, aperture

elongate, suture sometimes with narrow shelf.

LXXXVII. Bulimorpha.
u. Body whorl much longer than the spire, aperture elongate, an-

teriorly somewhat drawn out............... LXXXV. Fusispira,

u. Aperture rounded, body whorl not very large...............++. LLEL,

1111, With fine sigmoid striz............... LXXXI. Loxonema.

1111. Without strize (when perfect showing a faint peripheral

EMER i cclea cine rotcame, .eewenw cep caticad XLVI. Hormotoma.

13. Surface ornamented with ribs or spirals or with both,................0065 17*.
Be TRL SGCUEGES COMIMANE 50. J. 50 cue see vweceatasereedannncrecsshnetwaneys v.

v. With fine sigmoid transverse lines.............. LXXXII. Aclisina.

v:° With lines of growth not sigmoid................c0cssceccceeseees 2222.

a2o2. Spirals few (2 or 2) ‘or absent. 6 (oni. hoo ec war eg hese es tt.

tt. Whorls rounded, one or more spirals nodose.

LXXVIII. Acanthonema.
tt. Whorls angular, spirals not noded...................+. I2t..

12t. Short and tapering, embracing to angulation.
LXXXIII. Orthonema.
12+. Very long and slender, generally not embracing
to angulation...... ie ecarede CXXI. Zurritella.
2222. Spirals numerous; spire high and slender, many-
WINKIOW ty carowtisiersecosderkscaseeartuencdacte ten Saabs uu..

594 NORTH AMERICAN INDEX FOSSILS.

un. Coiled throughout jise.ccccise:sascecs CXXI. Turritella.
uu. Last whorls uncoiled................. CXXII. Vermetus.
2222. Spirals numerous; spire short, few-whorled........... vv.

vv. With two columellar plications.
CXCVII. Zornatellea.

vv. With one columellar plication...... CXCVIII. Acteon.
17*, Vertical sculpture dominant or equal to spiral..............sceeeeeees w.
yi. With sunple vertical, 11D8is..cccscseus tiers divapecacctia eee ee 3333.

3333. Form slender, turritelloid, protoconch erect, reversed.
CII. Zurbonilla.
3333. Form more tapering, whorls more rounding.
LXXXI. Loxonema.
3333- Short and rather solid, sutures scarcely impressed.
CXXVI. Hypsipleura,

w. With sharp, regular varices instead of ribs.......... CV. Scalaria.
W.. With bothiribs and spirals .:.0sjsccusidsi dialed. tends oR ee 4444.
4444. Later whorls mostly with shoulder angle bearing spinose
BOCES ys ustecainiag oPaiaica acs nisin sits se seen ae ww

ww. Spire high and slender............ CXXVII. Melania

CXXX. Goniobasis.

ww. Spire short, shell thick-set.....CXXIX. Pyrgulifera.

4444. All whorls fouiid:..........<¢s00-0005i0ean eedete nee eee XX.

xx. Columella with tooth........ bulges CIII. Chrysallida.

xx. Columella without tooth............ CXXX. Goniobasis.

CXXVII. Melania.
VI. Shell umbilicated, surface smooth, whorls flat or gently convex, suture not
impressed, aperture oval, protoconch dextral..................sseeeees CI. Niso.
G. Shells pleurotomarioid and murchisonioid, varying in form from naticoid or trochi-
form to high-spired, and characterized by a marginal notch or slit, often

continued backward into a slit-band.

VII. Shell turritelliform, with slender spire of numerous whorls..............000+ 14.
14. Lip; with deep noteh, but-no slit... 5...) casecess vsanktvanwesy essen eeeeeeeen 1S*,
18*, Band generally formed but rarely very prominent..................0+ x.

x. Aperture slightly produced anteriorly, no umbilicus.

XLVI. Hormotoma.
x. Aperture round, shell umbilicated............... XLVII. Celidium,
18*. Band strong, between two pronounced ridgeS...............eeeeeeeeees y:

y. Very slender, surfaces flat between carina, whorls compressed.
XLVIII. Solenospira.
18*. Band on shoulder formed by slight flattening and angulation of
WHORL Ts nc Setssudaratauneks oereastepaptcuaduba vdeo ces XXX. Ormospira.

14.) Toip wit Shit ca ck etna taepediqsdi cs Uivbicaaastwamdes gale edie ets Murchisonia.

VII. Shell relatively low-spired, apical angle varying from moderately acute (rarely
less than 45°) to moderately obtuse (rarely more than 120°)........ 15.
15. Whorls angulated, shoulder flat or gently concave (rarely gently convex).
19*.,
19*, Whorls embracing to angulation, forming more or less trochiform
SPINE... ise isles de nlagdal ad cause oasis baov vio hws o pa'in’S vita Rta eee enn Ze
z. Peripheral angulation drawn out into smooth or spinous flange.
XXVIII. Zuomphalopteris.

z. Peripheral angulation not drawn out... .....0.00<+s+<ssssesueneee 5555.

MOLLUSCA—GASTROPODA. 595

5555. Aperture with notch, but no slit; a peripheral band gen-

Cray PEESONE. 5 00'22 a 5nc 2. tatancereanadandamercensde mas? yy:
yy. Band vertical on angulation................ Seameuan aie 8
13t. Band faint, spire obtuse........ XXXV. Liospira.

13{. Band strong, spire mostly acute.
XXXVIII. Clathrospira.
yy. Band on upper side of angulation ..............s00000s l4t-
14f. Base nearly flat ..........000000s XXXVI. Zuconia.
14f. Base rounded.......0.....0 XXXVII, Zotomaria.
BGR 5. Apertenre Watt Silay ci siyencenn sida < as daaiuinaNowmanate peste aa’,
aa’. Base flat-or pently CONVEX, 2. 62 dessiscdaccssavecanses 15f.
15}. Slit short, upper sutural edges of whorls noded.
XLV. Trepospira.
157. Slit long, sutural edges not noded.
XLIV. Euconospira.
aa’. Base strongly rounded, suture channeled.
XLII. Bembexia.
aa’. Base ventricose, suture not channeled.
XLI. Mourlonia.

19*, Whorls not embracing to angulation, spire scalariform............. ar.
a’, With one or more strong carinz, the median one carrying the

NP IMONIAE, © Sits te whee actaan, haces dN venti Beeoeaneds cenit 6666.

6666. Aperture with notch only............. XXXI. Lophospira.

BOGS, Aperture With, SHEN cu wis Vensiinn cii'sei nesiesecgsclecien ocenesses bb’.

bb’. Band simple.............cccuerssee XXXL. Schizolopha.

bb’: Band, cremulated so. iaiescacsied oe XXXIV. Worthenia.

a’. With carinze between flat shoulder and large rounded body whorl.
7777:

7777. Aperture more or less drawn out anteriorly.............. Ce’.

cc’, Shoulder flat, at right angle to axis of coiling.
XXIX. Scalites.
cc’. Shoulder sloping, carrying the band.
XXX. Ormospira.
7777. Aperture not drawn out, band only on last whorl.
XXXIII. Phanerotrema.
15. Whorls rounded, globose, with vertical slit band near middle of whorl.
XXXIX. Euryzone.
15. Whorls rounded and vertically compressed, slit band above deep suture.
XL. Spiroraphe.

15. Whorls rounded except for strong revolving spirals....... XLII. Gyroma.
VII. Shell very obtuse (more than 120°) to flat, or with sunken spire, the last
prior! somictimes loosely COMED. i015. .cesceinsesdgnNcnesdaasevecdenreavnnad 16.

16. With strong keel on upper side of whorl..................cesscscereeceecees 20*,

20*, Lines of growth not deflected by keel...........LVII. Euomphalus.
20*. Lines of growth turning back over keel, forming distinct notch...b’.
b’. Keel low, within the periphery......... gesos inka narectp hh co's 8388.
$985... Spite Hat OF SUMRCI. 8. is cgiencoecavacthaeenades vase cease dd’.
dd’. Whorls slowly enlarging, flat on under side.

LII. Ophileta.

dd’. Whorls rapidly enlarging, under side concave.
LVI. Pleuronotus.

596 NORTH AMERICAN INDEX FOSSILS.

8888. Spire slightly elevated, shoulder deeply concave.
LV. Helicotoma.
b’. Keel marginal, often sharp and high, forming a nearly vertical
blade, spire deeply depressed............... LIV. LZecyliopterus.
20%, Keel withvdieunctsslit band iic6 icc. cases se nes dander: LIII. Ophiletina.
16, Notch only on outer margin of upper surface, no keel, with raised line
on upper surface, interrupting lines of growth...X XVI. Raphistoma.
16. Without notch or band, but with strong peripheral carina; depressed-

OMEGA saaae arena ve tvagpe de serereeee base erie scntn toons XXVII. Raphistomina.

H. Shell with aperture notched anteriorly or drawn out into a canal of greater or less
length.

VIII. Shell turreted, long and slender, aperture less than half the greatest length
of-shell; rarely 1s, eqital J .02.2.st5scesaaceeersee woeises toeack age een Ye

17. Aperture without expanded ‘lip; noteh short. .....:......2...2,.sagenceeeeeeee 21%,

21*. ‘Aperture’ modified by sharp folds. ..3..2....0.0:043.:/iccaen eee nde

ce’. Aperture more or less oblique .4:.02..5.4...se2esnccsaearcee eee 9999.

9999. Folds always on columella, generally on outer lip as

WHEL Sis) A dedonseec atest a vebatsacateccewss CXXXI. Merinea.

9999. Fold on outer lip, sometimes also on columella.

CXXXII. Werinella.
c’. Aperture elongate axially ; folds on columella ; notch faint.
RO,
50. Spire elevated, smooth or with ribs... CLXXXIV. Jtra.
50. Spire short, shell oval, surface smooth.

CLXXXIII. Marginella.
50. Spire short, surface ribbed.......CLXXXIVA. Conomttra.

21*. Aperture unmodified by folds.c. 2.00.05. 21.2.02000 ativedeaseeeeen a
d’. Aperture oblique, canal oblique....>..5...:...ceo-nsss<57e see 51.
50. “puriace ermamented. 2). 0iG. crc cos sae CXXXIV. Cerithium.

BI. OULMCe SMMOOTM, . 55.0500: ce. dare tsesaes CXXVIII. Melanopsis.

d’, Aperture oval to quadrilateral... ........2...c0.0«ss0ss50e eee 52.
R28 Outer is entire.) oe) five. Sasecnaae oheaewes CXCII. Zerebra.

52. Outer lip with faint notches............... CXXV. Glauconia.

d’. Aperture elongate; OVOId 20.20... ..sscasescany LXXXV. Fusispira.
d’. Aperture elongate, NarrOW.........c.0.00e<0, s002400ecacse seen 53.
§3. Outer Tp entire, oo. scctex eet. bcc bedeonde anes seats eae oy aeeee ce,

ee.) Surlace Smooth... ...cce2deseen ave LXXXIV. Sudbulites.

ee’. Surface cancellated by ribs and spirals.
CXXXIII. Bittiium.

53.. Lip with notel or shit. .0.... cc: ..5.000-++s0rdn one iT”,
ft 7: Noteh at ‘sttaré ac 0.5% isgdsteceaane CXCV. Mangilia.
fi7; Note below ‘situte.i 0s. .censtenee CXCIV. Drilla.

17. Aperture with outer lip expanded (often broken away or not shown in
immature individuals) J... 2.00. c0000sc0desecseuanasesunap eee ae*;

22*, Expansions wholly adhering to spire which may be mostly covered.
CXXXVI. Calyptrophorus.

22*, Expansion free or only partly adhering to spire, which may never-
theless be concealéd by it i200. .cdc..ceececeocsneceesscenaneeneeeae eo:

e’. Expansion simple, free, and blade or wing-like, sometimes di-

vided, anterior end drawn out into canal.
CXXXV. Anchura ~

MOLLUSCA—GASTROPODA. 597

e’. Expansion compound, posterior notch drawn out and adhering
to spire, sometimes covering it; outer lip often much divided.
CXXXVII. Aporrhais.

17. Aperture with outer lip thickened, but not expanded..................... 23%.
23*. Anterior notch very slight, shell small, surface ribbed, rarely
SIMGOK |. 2 sri. FGeauae ng es mete teas yee CXVI, Rissoina

23*. Anterior notch drawn out into short canal, inner lip reflexed.
CXL. Rimella,

Beene Short ond thighs, |... -..v.dicsWases«Hiatowaghchoaseuinled: uch awiaveke 18.
1§. All whorls smooth and rounded, shell subglobose...... CXC. Ancillopsis.

18. At least the younger whorls angulated or ornamented or both......... eu”.

BAY saber Tiyy nat ep iCUigte ai ta te Saas ecarat lates ooatasen chase (sieaecncdewss i.

f’. Surface with few strong fold-like spirals...CLXXXII. Zcphora.

f’. Surface smooth or with ribs and fine spirals,.................0008- 54-

54. With distinct shoulder, angle strongly nodose, notch faint.
CXXIX. Pyrgulifera.

54. Without shoulders, whorls rounded, notch strong.
CXLVII. Auccinum.

ga. Omer lip denticwlate or liratess, ic. dacs .cwssss tiv, soteac sack oeeb ee tua gw.
g’. Surface smooth or spiralled..:.............68. CXLVI. Columbella.
g*.. purine With: Tbs: and) Spiral e,.:o. icss. ce vaciceo bud dosex oben yenevenee 55:
55. With strong columellar folds............. CXCI. Cancellaria.
55. Columella without folds, rarely denticulate............... ge’.
gg’. Canal short, deflected, often only notch-like.
" CLI. WVeisa.

gg’. Canal longer, slightly bent or straight.
CLXXVIII. Cvosalpinx.
24*. Outer lip reflexed, inner lip expanded, anterior canal short, twisted
and bent backwards). ds:c.colgsin eed ihan cedets CXLIV. Cassidaria.
24*,. Outer lip thickened, inner lip smooth. Anterior notch very slight.
CXVI. Rissoina.
VIII. Shell varying in form, with aperture as long as, or longer than, the length

I NC IED is Ferny, sats eo gar nas dere THR Tes VUE Tn ARARTENSE Ee cad Ht deus Sh Ndignaes' 19.
Me oupeRtUe WAEMOMt EXDANCOC TD oi. cso c0s% acs inowsn sain saiievnecieneate ante ae.
25*, Shell fusiform and slender, drawn out anteriorly into more or less
SeCM Ge BNA, C2... tee tae Aas es UNSC <6 wiser ne copes amen wad be:

h’, Spire high, about equal in length to aperture.................... 56.

56. Outer lip with notch or slit, often with slit band........ hh’.

FE. CAN LODE fos cn taniasad cndvedowneed CXCIII. Pleurotoma.

hh’. Canal short, less than half the length of shell.....16+.

16f. Slit or notch at suture......... CXCV. Mangilia.

16f. Slit or notch below suture...... CXCIV. Drillia.

56. "Outer lip without motel or Slits)... icc. c.0scescescresaccioneas ii’.

ii’. Columellar lip without folds ..\.. ¢sc..sséeccense.s0s00es 177T.

17}. Early whorls ribbed, last whorls smooth, often

with sutural shelf........CLX XII. Clavilithes.

17f. All whorls smooth or only with spirals, body
whorl strongly convex.

CLXXVII. Mazzalina.

17{. All whorls ribbed or spiralled or both........... ve

t. Ribs strong, aperture not abruptly contracted

598

NORTH AMERICAN INDEX FOSSILS.

but narrowing gradually....CLXIV £xzlia
{. Aperture abruptly contracted to anterior canal.
a.
a. Spire slender, suture deeply impressed. 7’.
z’. Whorls mostly round, ribbed and
spiralled, an angulation may
appear in later whorls, canal
Straight... aceckaden meena a’.
a’. Protoconch erect, last portion
ribbed and ending ina strong
VEER .sosenateras CLX. Fusus.
a’, Protoconch mostly covered with
fine ribs, not ending in varix,
outer lip with slender lirz.
CLXIII. Hetlprinia.
1’. Whorls round, canal twisted.
CLXVI. Streptolathyrus.
z’, Whorls mostly angular, protoconch
merging into conch........0/.
6’, Ribs and spirals characterizing
most or all of the whorls,
apical portion of protoconch
of several whorls, gradually
increasing.
CLXI. Falstfusus.
6’. Ribs replaced by spires, apical
whorl or protoconch swollen,
erect.
CLXII. Fulgurofusus.
a. Spire short, thick and few-whorled.
CLXXVIII. Uvosalpinx.

ii’. Columella with folds or plications... ..........2s0e006 18.
18+. Shells with ribs and nodes or smooth in adult,
but. not spinose. <......0....s«.ss.0saseeaaa noe

tt. Protoconch papillose.
CLXXIV. Zurbinella.

{{}.' Protocench not papillose.........coneeeeee b.
6. Spire slender, fusiform, sutures deep, ribs.

and spirals well developed......2’.

2’, Plications few, strong....... canes oh,

c’. Canal shorter than spire....a/a.

a’a. Inner lip strong, often

umbilicated, with sev-

eral plications; outer

lip lirate.

CLXV. Latirus.

a’a. Inner lip with a single
tooth-like plication.

CLXXI. Odontofusus.

c’, Canal as long as spire; inner lip

MOLLUSCA—GASTROPODA. 599

weak ; no umbilicus or lire.

CLXVII. Pseudolathyrus.

2’. Plications in form of slender lines or

ridges.

CLXIIIA. Barbarofusus.

6. Sutures not so deeply impressed ; aper-

ture less rapidly contracting, ribs and

spirals fainter; typically a strong, ob-
lique, anterior columellar fold.

CLIX. Fasciolaria.

18}. Shell strongly spinose.......... CLXXV. Vasum.

h’, Spire short and thick, less than apertural length................ 57-
57: Whorls moderately embracing ......:0sc.cectsssecesecaneveccas iV

jj’. Aperture abruptly contracted to anterior canal, ribbed

mine) “Soiree: ore coces oe ocsmes cents ~Siaaebeuwees 1of.

I9t. Columellar and outer lip lirate.
CLXIII. Hezlprinia.
I9t. Columella with single tooth.
CLXXI. Odontofusus.
I9t. Columella smooth, canal short, slightly curved.
CLXXVIII. Urosalpinx.
‘, Aperture not-abruptly, contract€d)..:.6c.sccscees cues 20f.
20f. Columella with strong plications............... tr.
ttt. Whorls round or moderately angulated with
continuous ribs, spinose or tuberculated
on the angle....CLXXXV. Volutilithes.
ttt. Whorls angulated and generally spinose ;
aperture broad in front, canaliculated pos-
teriorly ; plaits numerous.
CLXXXVI. Voluta.
ttt. Whorls rounded in adult only, and without
ribs or spirals.....CLXXXVII. Aurinia.
ttt. Whorls round, smooth throughout........... t.
c. Aperture sharp behind, widening forward,
oblique grooves on columella...3/.
3’. Surface smooth.
CLXXXVIII. Olkva.
3’. Surface with vertical striations.
CLXXXIX. Olfivula.
¢. Aperture more or less patulous, strong pli-
cations on columella.
CLXXVI. Caricella.
57. Whorls strongly embracing, rounded.................s00000 kk’,
kk’, Aperture abruptly contracted to long canal.
CLIII. Pyropsis.

kk’. Aperture not contracted iio. . cedeeu sac te wc esawedaveds 21.
21. Aperture wide and patulous......CXLV. Pyru/la.
Sf PAPOPtOre WALCO Wii iinces deena cavenn as viene cos ccs Fit.

iite Inner lp not éxpanded.. oc. ovis.ccc.douse d.

d, Aperture sharp behind, widening forward.
5”

600 NORTH AMERICAN INDEX FOSSILS.

5’. With several oblique folds on the

columella.
CLXXXVIII. Okva.
5’. Without folds....... CXCVI. Conus.
ad. Aperture blunt behind, scarcely widening
POP WATGn05 si.cene-ctei semen eee o.

6’. Lip and columella smooth, spire
conical or flat... CXCVI. Conus.
6’, Lip and columella denticulate, spire
mostly covered.
CXLIII. Zvrato.
t{it. Inner lip expanded, partly covering body
whorl and spire,........<..<ieccumnenennee t.
e. Outer lip smooth,
CXXXIX. Orthaulax.
e. Outer lip lobed.
CXXXVIII. Pugnellus.

57. Whorls strongly embracing, angulated............ dee iV’.
ll’. Spire very flat, canal strongly contracted below body
WOT 5... cicndcnsicceessseecnkw nye esaen eee 22T
22}. Protoconch papillose, columella plicate, outer
Lip Tiate cis wts ies mies CLII. Zudicla.
22+. Protoconch not papillose, without columellar
plices Or Mires... sacscccteisenes CLIII. Pyropsis.
ll’. Spire of moderate height, often continuously conical,
whorls angulated..........<sssvasrssssdaeeeana 231.
23{. With canal abruptly contracted below body whorl
outer whorl biangular....... CLIV. Perisolax.

23+. Canal gradually contracted below body whorl.
5t.

5{. Shell with flat or concave sloping shoulders
and angle nodose, keeled or spinose, at
least In YOUNG. ...c0000.00040 cause

f- Shell small... i.5.22.255....07 0 ey

7’, Canal straight.
CLVIII. Levifusus.

7’, Canal reflexed.
CLVII. Strepstdura.
f- Shell large. .2....2...+ssses0s0seeeeeeean 8’.

&’, Suture channeled.
CLVI. Sycotypus.
_ &’, Suture not channeled.
CLV. Fulgur.
5i. Shell with several angulations, and wide
patulous canal.......:.::.:ss00neeee eee £
g. Spire low, angulations pronounced on
body whorl...... CLXIX. Fulguroficus.
g. Spire moderately high, angulations less
pronounced on body whorl.

CLXX. Fusoficula.
25*. Shell fusiform, but thick set, spire of few rapidly enlarging whorls. i’.

MOLLUSCA—GASTROPODA. 601

i’. Canal strongly: deflected. cicaduawss «i cckecedaivencacnwals eaeanie Pkeae 58.
58. Surface with spirals and in some cases with ribs also.
CXLIX. Stphonaha.

58. Surface with ribs and spirals, the former often thickened and

SPM OSE cca awl wee sese sacs dos nitneoe det CLXXIX., Murex.

i’. Canal straight or faintly deflected, aperture wide, surface with
spirals and. ribs Tavely smooth c.).....-.5.0cscseuashasesne 59.

59. Spirals faint, sometimes obsolete............. CL. Neptunea.

59. Spirals moderate, shell small, aperture rather abruptly
COMERS 205 5 osu ecwonde esas «alnaicioois CLXVIII. Lirofusus.

59. Spirals strong, shell large, aperture but slightly contracted.
CXLVIII. Buccinofusus.
25*. Shell not fusiform, spire small, aperture occupying greatest length of

BRETAL GN GBTR LG ORs Siar So teaaane ee vide ao Whee cede sc psn ve ane Hu duasuaidan ae

j’. Shells short and thick, more or less globular.................+6- 60.
60. All whorls smooth, not umbilicated....... CXC. Ancillopsis.

60. Whorls more or less ornamented, at least the earlier ones ;
shell umbilicated...... haute Wier dsleanees CLXXIII. Lacinia.

j’- Shell elongate....... daladdvontarsstatreegrsade ha Need cause Ge ksee seRees 61.
61. Columella with plications or oblique grooves, outer lip
SANCMIEEY Silo bas 91 cia can een Suiie ean Svea Rhee e mm’.

mm/’,. Whorls rounded im adult,)\.3...)0...¢seeledecs easedads 24T

24f. With continuous ribs....CLXXXV. Volutilithes.

DAT SMM tetasnal Wii eyhs ARF scold cn dante sda san 6t.

6{. Round-whorled in adult only.
CLXXXVII. Aurinia,
6{. Round-whorled and smooth throughout. ...4.
h, Aperture narrow behind, widening for-
oS Neeatienia'sl BWaee J.
9’. Surface smooth.
CLXXXVIII. Okva.
9’. Surface vertically striate.
CLXXXIX: Olkvula.
A. Aperture more or less patulous.
CLXXVI. Caricella.

Bint 5. WN MATS: PURE I GE Sk cin ves oe naw nc anv tedangae aden 25f.
25+. With continuous ribs, spinous or tuberculated on
REO in cet ses ceaeences CLXXXV. Volutilithes.

25f. ai sanerne spinous, aperture broad in front.
CLXXXVI. Voluta.
OF, Raliegh, 9 ess ds so tdakec a tn nina Raa okies nn’,
nn’. Columellar and outer lip with numerous small notches.
CXLII. Cyprea.
nn’. Columella smooth except for plications; outer lip

RGN GO SE Scie ened cana tes thansce CXLIII. LZrato.

nn’, Outer lip smooth............. CLXXXIII. Marginella.

Oks Cobuirielia MO EEE eedien seis 190s «sdxcniepiatone 00’.
oo’. Form conical, spire flat.................. CXCVI. Conus.
00’. Form subconical, spire elevated.........CLV. Fulgur.

eg; Aperture with expanded outer lip......s.cscsecccesscccsssssceessesencsgerecs 26*,

602 NORTH AMERICAN INDEX FOSSILS.

26*, Apertura] expansion one of three or more similar ones on same

WHOM MOLINE WAFIEES sects bn cue de Raho ndnt case reo ten svn slessied ia ueate k/.
k’. Varices broad lamellz or rows of spines....CLX XIX. Murex.
k/. Varices rib-like, ending in hollow shoulder spines.............+: 62.

62. Varices of considerable strength, anterior canal covered.
CLXXX. TZyphis.

62. Varices weak, anterior canal open...... CLXXXI. Zrophon,

26%, .Apertural expansion jaloné presente. .i.i.0s3 .o.1.0300sddedaeossaeeeeeeee ¥;
1’. Expansion a broad and thick lamella, at posterior notch covering
SPLEEN osiirs were cninak ca Kar Rabies an nid «tip siewie Seu geet Gy cee 63.

- 63. With anterior and faint marginal notch...CXLI. Strombus.

63. Without marginal notch.............. CXXXVII. Asorrhais.

I’, Expansion lobed or digitate sss icici. wichstisoeseuep tselisaneenteeea 64.

64. Inner lip expanded and partly covering spire and body

NELQUD Koma, seats: Hams ew ae BBS CXXXVIII. Pugnellus.

64. Inner lip not expanded, but expansion of outer lip often
partly-covering. the spire.\..i¢..,0..s02 CXLIA, Pterocera.

VIII. Shell with spire sunken beneath body whorl, which often completely hides
PRE. SPIE sa. 50:2 Fa sive wcitesagie's s vinlye viens Vine SRNR oh ia WeNoce ae aren eke ee 20.

20. Outer lip enrolled in adult, marginal slit lined by denticulations.
CXLII. Cyprea.

20, Outer Tp sharpi.i.ss .diodpescees toattowil 0s, .x+chiels odee oe sk cee een r fiale
27*.. Apex perforated, over. the sunken spire. ...:...00«ss<-0cn-sb eee m/.

m/’, Shell oval, inflated columella smooth............... CCIII. Bulla.

m/’. Cylindrical, columella with small plications .....CCV. Cylichna.

27%: Apex not. perforated . is a.cossicse ccc vewse sce cite ogcnnsctea ee eee aetna n’.

n’., Cylindrical, aperture extended posteriorly so as to form sharp
point above apex, surface smooth or with few spirals,
CCIV. Volvula.
n’. Oval without projecting point, surface with fine spirals.
CCI]. Haminea.

I... Not belonging to the preceding GIVISIONS .......4 s<ss<ssasc<esupeecesons svecbesge annnemann EX.
IX. Shell twisted or loose-coiled, whorls not in contact .............ceeeeeceeceeeess 2%:
21. Irregularly twisted, with or without apical coil................cceseeeeeeees 28*.

28*, Tube entire, ornamented by longitudinal strize or smooth.
CXXII. Vermetus.

28*, Tube with a slit, OF a TOW Of POLES... 5208008 CXXIV. Sitlguaria.
21. More or less regular, loose spital..i.........0<<..s0000ssssssneeseasuneeunaae 2g:
29*. Twisted into corkscrew spiral... ..... to deere ays s0eecns en ann Oo’.

o’, Spiral broad, open; tube scarcely increasing.
CXXIII. Laxispira.
o’. Spiral long, slender, tube regularly increasing................... 65.
65. Taberentire....viessess CXXI (internal mold of) Zzrritella.
65. Tube with slit or row of holes..........CXXIV. Sit/iguaria,
29*. Twisted in single plane, from a part of a volution to several volu-

tions not in contact........... hens seieidee s.oelsivid aa ewinlse ge a ee p’.
p’. Whorls round, unmodified by carina............LI. Phanerotinus.
-p’.. Whorls with.carina or keel.on upper side.............cosmsuusan 66,

66. Carina blunt; aperture with broad, shallow notch.
LIX, LEccyliomphalus.

GASTROPODA—PALAACM AIDE. 603

66, Carina sharp, when perfect drawn out into high collar;

apertutal Noten Geet os. scdocnnsantee LIV. Lecylopterus.

Pag. Spel! coiled. .:...0.3% Ln aia melght Sl eieebaerin aera BONG malar de be oles ete eee eet a eee 22;
22. Cylindrical or oval, generally narrowing towards aperture.............. 30%,
30*. Aperture incomplete, oblique.or anterior. ©. .4.ca0e--.2caciseneoaeataes q.

q’. Columella-and: outers lige with teeth ooci ve cncseasersenaness couse tans 67.

67. Columella with callus, aperture with rounded posterior

HOCH Gc. 5 Ridacaapasseaaevssatiacs oe CCXVI. Anthracopupa.

67. Columella without callus, no posterior notch. ;

CCXV. Pupa.
q’. Columella and lip without teeth; center of outer lip nearly in
extol lutie GF Shell. coi. S<aktsoeansanecbas CCXVII. Dendropupa.

Family PAL@ACMID# * Grabau and Shimer.

I. Tripiipium Lindstrom. (Emend. Berkey.)

Patelliform obovate shells, narrowest anteriorly, often acuminate ;
conical with beak varying from nearly marginal to overarching
anteriorly ; muscular scars in rings of seven or eight disconnected
pairs ; anterior pair meeting in front beneath the beak. Lines of
growth, and rarely obscure broad radial plications, mark the sur-
face. Cambric—Ordovicic.

T. rectilaterale Berkey. (Fig. 802, a, 0.) Cambric,

: b
Fic. 802. a, 6, Triblidium rectilaterale; c,d, T. convexum, e, f, T. barabuensis,
peep at: (After Berkey, Am. Geol.; 21.) !

Large, conical, high, with straight sides and apex somewhat
behind the front ; aperture ovate-acuminate.
St. Croix fBrecbach) of Minnesota.

| oa ‘

* The names starred are new,

604 NORTH AMERICAN INDEX FOSSILS.

2. T. convexum Berkey. (Fig. 802, c, a.) Cambric.
Larger than preceding, lower, and with more broadly ovate-
acuminate aperture, and anterior beak.
Associated with the preceding.
3. T. barabuensis Whitfield. (Fig. 802, e, f) Ordovicic.
More narrowly ovate than preceding ; beak slightly overhang-
ing; anterior slope concave.
In the Lower Magnesian series (Jordan sandstone) of Wis-
consin.
4. T. nycteis (Billings). (Fig. 803.) Ordovicic.
=~

Fic. 803. TZriblidium nycteis. (After Billings. )

Larger than the preceding, and with the beak curved down-
wards.
Beekmantown of Mingen Islands.

II. Hetcronopsis Ulrich and Scofield.
Like Z7ibiidium, but surface marked by fine radiating striz.
Ordovicic—Siluric.
5. H. striata Ulrich. (Fig. 805, a, 0.) Ordovicic.
Ovate, rather narrow in front, apex incurved and slightly pro-
jecting ; radiating lines round, equal.
Upper Cincinnatian : Kentucky and Ohio.

III. HypsreLoconus Berkey.
High conical shells, differing from Zrid/idium in being curved
towards the broader side of the shell. Cambric—Ordovicic.
6. H. recurvus (Whitfield). (Fig. 804, a, 0.)
Cambric—Ordovicic,
Curvature very slight, not beyond posterior margin; shell high ;

angle somewhat variable. |
St. Croix (Upper Dresbach) and Lower Magnesian of Minnesota

and Wisconsin. .

- = we

GASTROPODA—PALZAACM 4IIDEZ. 605

7. H. cornutiformis Berkey. (Fig. 804, c, d@.) Cambric.
Slender and high, strongly curved, beak much overhanging.
St. Croix formation (Dresbach shales), Minnesota.

8. H. franconiensis Berkey. (Fig. 804, ¢, /) Cambric.

Sten
Fic. 804. a, 6, Hypseloconus recurvus; c,d, H. cornutiformis ; e, f, H. franconien-
sts, (After Berkey, Am. Geol., 21.)

Curved so as to perform half a volution.
St. Croix formation (Franconia sandstone) of Minnesota.

IV. ARCHINACELLA Ulrich.

Patelliform shells with surface showing only lines of growth, an-
terior end generally widest ; apex in front of center and often sub-
marginal, generally curved, muscular scars forming a continuous
band. Ordovicic.

g. A. deformata Hall. (Fig. 806.) Ordovicic.

. Broader proportionally than A. de/eta, beak more anterior and
overhanging (max. size II x 8 mm.).
Common throughout the Chazy of the Lake Champlain region.

Fic. 805. a, b, Helcionopsts striata ; =; Archinacella deleta; f, 7, A.simulatrix; g,
h, A, cingulata, (After Ulrich, Pal. Minn. )

606 NORTH AMERICAN INDEX FOSSILS.

10. A. deleta (Sardeson). (Fig. 805, c—e.) Ordovicic.
Small, elliptical, smooth, apex a short distance from front,
incurved.
Black River of Minnesota.

1. A. patelliformis (Hall). Ordovicic.
Small, slightly narrower anteriorly, beak projecting to margin
of shell ; growth lines sublamellose.
Trenton of New York.
12. A. simulatrix Ulrich and Scofield. (Fig. 805, f, 2.)
Ordovicic.
Small, widest anteriorly ; beak slightly projecting anteriorly.
Black River of Minnesota. Trenton of Kentucky. |
13. A. cingulata Ulrich. (Fig. 805, g, 4.) Ordovicic.
Large; beak strongly incurved and projecting slightly beyond
the somewhat broader anterior end. Growth lines sublamellose.
Trenton of Kentucky.

V. PaLta#acmM#aA Hall and Whitfield.

Patelliform, circular or elliptical shells with subcentral apex and
broad concentric wrinkles marking the surface. Cambric—Ordo-
VICIC.

14. P.(Parmophorella) acadica (Hartt). (Fig. 809, c.) Cambric.

When uncompressed, oval in outline, with beak one third or one
fourth distant from the end. Concentric wrinkles weaker on

Fic. 806. Archinacella de- Fic, 807. Paleacmea typica. (After Hall &
formata. (After Raymond. ) Whitf., 23d N. Y. Mus. Rep.)

shorter end. When depressed, beak appears subcentral as in the
figure.

St. John formation of New Brunswick a 1, c) and Hayward
argillutytes of Braintree, Mass.

15. P. typica Hall and Whitfield. (Fig. 807.) Cambric:

GASTROPODA—PALZEACM AIDE. 607

Broadly oval, depressed conical, apex nearly central; undula-
tions strong, subangular. (Type of genus.)

Potsdam sandstone of New York.
16. P. irvingi Whitfield. Cambric.

Larger than preceding, but smaller than the next, more nearly
circular, with compressed apex, and broad but depressed flat
undulations.

St. Croix beds of Wisconsin.

17. P. quebecensis (Billings). (Fig. 808.) Ordovicic.

Fic. 8308. Paleacmea quebecensis, Fic. 809. a, 6, Paleacmea humilis; c,
<x %. (After Billings. ) P. (Parmophorelia) acadica. (a, 6, after

U. and S., Pal. Minn. ; c, after Walcott,
Ball. ro, U.S::G. Sx)

Large, elliptical, conical, three inches or more in length, with
excentric apex, and coarse, shallow concentric undulations.
Quebec (Beekmantown) of Point Levis, Canada.

18. P. humilis U. and S. (Fig. 809, a, 0.) Ordovicic.
Small, broadly subovate, anterior outline semicircular, posterior

prolonged. Apex slightly bent forward, a short distance in front

of center. Concentric wrinkles few, strong, growth lines faint.
Stones River and Black River of Minnesota.

VI. HeELcIONELLA * Grabau and Shimer.

Differs from Paleacmea in having the apex submarginal and
incurved. Concentric folds broader and most pronounced on the
side away from the beak ; faint or obsolete under the beak. (Type
Metoptoma rugosa Hall.) Cambric.

19. H. rugosa (Hall). (Stexotheca rugosa of authors.) (Fig.
810.) Cambric.

608 NORTH AMERICAN INDEX FOSSILS.

Elliptical to subcircular, moderately high, with beak slightly
incurved. Concentric folds strong on the convex side, nearly
absent on concave.

Lower Cambric (Georgian) of Troy, N. Y.; Bic Harbor, Que-
bec; l’Anse au Loup, Labrador, and (?) Etcheminian of New-
foundland.

VII. Scenetra Billings.

Conical, often high, shells with subcentral apex and radial pli-
cations. Muscular scars forming a circle above the mid-height.
Cambric—Devonic.

20. S. reticulata Billings. (Fig. 811, a, 0.) Cambric.

Fic. 810. Selcionella ru- Fic. 811. a, 4, Scenella reticulata, en-
gosa, showing variations. (After larged ; c,d, S. retusa. (After Walcott, roth
Walcott. ) Ann, Rep. U. S. G. S.)

Small, with excentric apex, and an obscure carina extending
from apex to one side of margin.
Etcheminian of Newfoundland and Massachusetts.

21. . netusa Ford: (Pig. 811, 2d.) Cambric.
More nearly circular, smaller, beak subcentral, front slope con-
cave ; faint concentric and longitudinal strize present.
Georgian of Troy, N. Y., Bic Harbor, Canada.

22. S. superba Billings. Ordovicic.
Large, ovate to circular, diameter up to go mm., height some-
what over half diameter, apex subcentral ; radiating plications fine,
sharp.
Stones River of Minnesota; Black River of eastern Canada.

23. S. montrealensis (Bill.). (Figs. 812, 813.) Ordovicic.
Small, obtusely elliptical, acutely conical, apex slightly excen- »

GASTROPODA—BELLEROPHONTIDE. 609

tric and curved forward, radiating striz fine, concentric growth-
lines and occasionally wrinkles occur.
Chazy of Montreal and New York.

Fic, 812. Scenella mentrealense, oe 813. Scenella montrealense,
<2. (After Raymond.) x< 2. (After Raymond. )
.

VIII. Lepetorsis Whitfield.

Broadly oval, low conical shells with subcentral apex, growth
lines, and more rarely radiating lines. Muscular impression horse-
shoe-shaped, open in front. Mississippic—Carbonic.

24. L. levettei (White). (Fig. 814.) Mississippic.

Fic. 814. Lefetopsis levettet. a, perfect shell; 4, with apex removed, showing im-
pression of muscular area; c, a more elongate form ; d, side views of the two forms
superposed. (After Whitfield. )

Nearly oval, conical, beak slightly excentric, anterior and pos-
terior slopes slightly different ; growth lines somewhat lamellose,
radiating strize obscure.

St. Louis group of Indiana.

Family BELLEROPHONTID& M’Coy.

IX. CyrtTo.uires Conrad.

Shells coiled in median plane, regularly enlarging, angulated or
carinated laterally and on dorsum, aperture with or without
median notch. Ordovicic.

25. C. ornatus Conrad. (Fig. 815, a, 0.) Ordovicic.

610 NORTH AMERICAN INDEX FOSSILS.

Two to three volutions sharply carinate dorsally, sides sub-
angular; surface pitted. Aperture a little wider than high.

Common in the Lorraine and Richmond of New York, Canada,
Pennsylvania, Ohio, Indiana, Kentucky,

26. C. retrorsus Ulrich. (Fig. 815, c, @.) Ordovicic.
More rapidly enlarging than the preceding ; aperture subquad-

Fic. 815. a, 4, Cyrtolites ornatus (6, enlargement of surface) ; ¢, d, C.
retrorsus; e-g, C. carinatus. (After Ulrich, Pal. Minn.)

rangular, keel sharper; transverse ribs curving backwards on
dorsum.

Black River and Trenton of Kentucky, Tennessee, and Ohio,
and Eden of Ohio and Covington, Ky.

27. C. carinatus Miller. (Fig. 815, e-g.) Ordovicic.
Sharply carinate, with latero-dorsal slopes concave; margin
notched medially ; sides sharply angulated ; surface without un-
dulations, but with lines of growth marked.
Cincinnatian of Cincinnati region, Wisconsin, Iowa, and probably
Minnesota.

X OwENELLA U.and S

Thin, subglobose, bellerophontid shells with rounded outer sur- |
face and gradually enlarging, dorso-ventrally compressed, close-
coiled whorls; open umbilicus, and broad insinuation of the lip
without slit band. Cambric.

28. O. antiquatus (Whitfield). (Fig. 816.) Cambric.

Fic. 816. Owenella antiquatus. (After Ulrich and Scof., Pal. Minn.)

GASTROPODA—BELLEROPHONTIDZA. 611
Small, generally not more than => in. in diameter; whorls
strongly involute, surface with growth lines.
St. Croix sandstone of Wisconsin.

XI. ProrowartTuHia U. and S.

Bellerophon shells with aperture large but not abruptly ex-
panded ; bilobate or deeply lobed outer lip, but no slit band; and
when perfect, fine revolving and transverse striz. Umbilicus
mostly small. Ordovicic—Devonic.

29. P. rectangularis U.andS. (Fig. 817, a—c.) Ordovicic.

Fic. 817. a—c, Protowarthia rectangularis ; ad-f, P. pervoluta, g-1, P.
cancellata. (After Ulrich, Pal. Minn.)

Abruptly rounded dorsally, with small umbilicus and deep mar-
ginal sinuation, the lobes of which are rectangular.
Stones River group of Minnesota, Wisconsin, and Illinois.

30. P. pervoluta U. andS. (Fig. 817, ad) Ordovicic.
Dorsum rounded, emargination moderate, lateral lobes of lip
rounded.
Black River and lowest Trenton of Kentucky and Black River
of Minnesota.

31. P. cancellata Hall. (Fig. 817, g-z.) Ordovicic.
Regularly rounded dorsum with minute umbilicus and only
moderately expanding lip. Sinus deep and more nearly U-shaped.
Surface beautifully cancellated by transverse and revolving striz.
Trenton to Richmond of New York, Canada and throughout
the Middle States, chiefly in the Trenton.

612 NORTH AMERICAN INDEX FOSSILS.

32. P. acutilirata Hall. Devonic.
Umbilicus rather large and margins subangular ; sinus broad
and of moderate depth.
Hamilton of New York, Pennsylvania, etc.

XII. BucAnrEL_tA Meek.

Bellerophontoid shells with deeply trilobed dorsum, slightly em-
bracing, dorso-ventrally compressed volutions, sinuate aperture
without slit band, and faint surface striz. Siluric.

33. B. trilobata Sowerby. (Fig. 818.) — Siluric.

Small, strongly trilobed, the median lobe larg-
est; sinus broad and shallow; surface with fine
Fic. 818. 8u- revolving lines and lines of growth.

caniella trilobata. Wfiedina and Clinton of New York, Ohio, Penn-
(After Hall. )

sylvania. etc. Also Europe.

XIII. Tretrranota Ulrich and Scofield.

Bellerophontids with dorso-ventrally compressed shells, laterally
expanding aperture, open umbilicus, and sinus ending in a short
slit situated on a median revolving fold and flanked on either side
by one or more revolving ridges ; surface with sharp growth lines.
Ordovicic.

34. T. bidorsata (Hall). (Fig. 819, a—d.) Ordovicic.

een
i

a ae
St
ia eR

Fic. 819. a-d, Tetranota bidorsata (d =enlargement of surface); e-h, 7, 7. |
sexcarinata (/= transverse section of whorl); 7-4, 7. odsoleta. (After Ulr. and
Scof., Pal. Minn.)

GASTROPODA—BELLEROPHONTIDZ. 613

With one obtusely angular ridge on each side, half way between
umbilicus and ridge flanking the sinus. A median ridge occurs in
the slit band, though often not preserved.

Stones River of Tennessee; Black River and Trenton of Min-
nesota, Canada, New York, and Tennessee.

35. T. sexcarinata Ulrich and Scofield. (Fig. 819, e-h, 2.)
Ordovicic.
Larger, with stronger and more persistent ridges, with an addi-
tional one on either side, making six in all. Surface striz strong.
Stones River of Minnesota, Illinois, and Tennessee, and Trenton
of Minnesota.
36. T. obsoleta Ulrich and Scofield. (Fig. 819, 7-2.)
Ordovicic,
Revolving ridges obsolete, umbilicus smaller than in 7. dcdorsata,
volutions more rounded.
Stones River of Wisconsin, Black River of Kentucky and Min-
nesota, Trenton of Minnesota, Utica of Cincinnati region.

XIV. Bucania Hall. (Emend. U. and S.)

Bellerophontid shells with generally large umbilicus and de-
pressed volutions which do not expand rapidly or abruptly ; aper-
tural sinus ending in a slit; slit-band distinct, raised or depressed ;
surface with oblique revolving lines and lines or lamellz of growth.
Ordovicic.

37. B. sulcatina Emmons. (Figs. 820, 821). Ordovicic.

“Fl SLITS
fi ‘

Fic. 820. Bucania sulcatina, K %. Fic, 821. Bucania sulcatina,
(After Raymond. ) < s

_ Large; whorls angular at umbilicus, width of aperture about
equal to height of shell. Apertural angles acute. Surface with
strong revolving and finer transverse strie.

Chazy of Champlain region.

614 NORTH AMERICAN INDEX FOSSILS.

38. B. halli Ulrich and Scofield. (Fig. 822.) Ordovicic.
Aperture twice as wide as high. Lateral anglesacute. Smaller
than preceding.
Stones River of Minnesota, Black: River of Kentucky.

Fic, 822. Aucania hal. a, 6, side and dorsal v'ew; ¢, a, sections of whorls.
(After Ulrich and Scofield, Pal. Minn. )

39. B. punctifrons Emmons. Ordovicic.
Rather small with large umbilicus and subpentagonal aperture

slightly wider than high; slit band somewhat elevated; surface

covered by a meshwork, which gives it a punctate appearance.
Trenton of Canada, New York, Tennessee.

XV. SALPINGOSTOMA Roemer,

Bellerophontid shells, with gradually enlarging, scarcely em-
bracing volutions, and abruptly expanding, trumpet-like mature
aperture. Inner volutions with a slit band as in Bucanza, last half
of whorl with long, narrow slit, closed behind the peristome ; sur-
face with revolving lines often oblique and wavy, and lines of
growth. Ordovicic.

40. S. buelli Whitfield. (Fig. 823, a—c.) Ordovicic.
Of about three and a half volutions, rather large; gradually ex-
panding ; lip flaring out abruptly.
Stones River and Black River, Minnesota, Wisconsin, and
Illinois.

41. S. expansa Hall. Ordovicic.

Subangular, large, of about four volutions, with abruptly ex-
panding aperture, and obtusely carinated dorsum. Section of last
volution subtriangular, surface striate.

Trenton limestone of New York, Canada, etc. : pe
42. S. richmondensis Ulrich. (Fig. 823, d.e.), | Ordovicic..

About three volutions; the last expanding. somewhat more
rapidly, and the lips flaring less abruptly than in the preceding ,
species. Richmond group of Indiana.

GASTROPODA—BELLEROPHONTID. O15

In the Trenton limestone of New York, Canada, etc.

Fic. 823. a—c, Salpingostoma buelli, K 7%; d, e, S. richmondensis, x %. (After
Ulrich, Pal. Minn. )
XVI. Trematonotus Hall.

Like Salpingostoma but with a series of elongate elliptical per-
forations in the center of the last whorl, instead of a single long
slit. Siluric—Devonic. |

43. T. alpheus Hall. (Figs. 824, 825.) Siluric.

Fic. 824. TZrematonotus alpheus, XK 24. (After Clarke & Ruedemann,
Guelph Fauna. )

Whorls 3 to 4, scarcely impressed by preceding ones, aperture
with flaring lip, turning out at right angles and finally reflected,
frequently long. Surface with coarse flat-topped spirals, increased

by intercalation, and concentric wrinkles. Perforations on narrow
keel.

616 NORTH AMERICAN INDEX FOSSILS.

Guelph of New York, Canada, IIl., Ohio, and Racine beds of
Wisconsin.
44. T. profundus Conrad. Devonic.

More strongly embracing, obscurely carinate whorls, with pro-
foundly flaring margin, the latter seldom fully preserved.

Becraft limestone of eastern New York (common).

XVII. Oxypiscus Koken.

Strongly compressed, disciform shells, with mostly slightly
embracing, gradually expanding, and sharply-keeled whorls, a
lanceolate or subtriangular aperture, without inner callosity, and
a deep V-shaped dorsal sinus continued as a long and _ narrow slit
in dorsal keel. _Ordovicic—Mississippic.

45. 0. subacutus Ulrich. (Fig. 826.) Ordovicic.

Fic. 825. TZrematonotus alpheus, Fic. 826. Oxydiscus sub-
< %, ‘section. ( After Clarke & acutus. (After Ulrich & Sco-
Ruedem. ) field, Pal. Minn. )

Volutions embracing one third to one half of the preceding,
acutely carinated; section of whorl subtriangular, abruptly in-
flected at umbilicus.

Trenton of Kentucky, Tennessee (?), and Minnesota (?).

46. O. curvilineata (Conrad). (Fig. 827.) Devonic.

Whorls embracing about half the preceding one ; sides rounded,

rather abruptly inflected at the umbilicus, sinus about one fourth.

of a volution ; striz of growth often in fascicles ; keel sharp.
Oriskany, Schoharie, and Onondaga of New York.
47. O. cryptolites (Hall). Mississippic.
Whorls more embracing than in preceding species, so as to leave
only a small umbilicus; less compressed; carina less sharply
marked ; aperture subtriangular.

ae _

]

|

GASTROPODA—BELLEROPHONTID. 617

Rockford limestone of Indiana, Kinderhook of Iowa, Marshall
of Michigan, and Waverly group of Ohio.

Fic. 827. Oxydiscus curvilineata. (After Hall.)

XVIII. PHRaGMoLITHES Conrad. (Conradella U. and S.)

Differs from the preceding in the absence of marginal angular
sinus and in the coarsely wrinkled lamellose growth lines. Slit
generally long, aperture expanded. Ordovicic.

48. P. triangularis U. andS. (Fig. 828, a, 4.) Ordovicic.

Fic. 828. a, b, Phragmolithes triangularis,; c, da, P. fimbriatus ; e, f, P. dyeri
(f/ enlargement of surface). (After Ulrich and Scofield, Pal. Mirn. )

Readily distinguished by its rather rapidly enlarging volutions
of strongly triangular section and abrupt inflection at the um-
bilicus.

Stones River of Minnesota, Wisconsin, Illinois and Tennessee.

49. P. fimbriatatus U.andS. (Fig. 828, c, @.) Ordovicic.

’ Rounded whorls sharply carinate and with periodically expand-

ing lip, leaving numerous strong imbricating growth lamelle.
Stones River group of Minnesota and Illinois.

50. P. compressus Conrad. | Ordovicic.
Volutions scarcely contiguous, rounded, and sharply and pro-

618 NORTH AMERICAN INDEX FOSSILS.

foundly carinated ; narrower and less rapidly enlarging than pre-
ceding species ; surface striz strongly zigzag, rather distant, and
subimbricating, with finer striz between.

Trenton of New York and adjoining Canadian regions.
si. Po dyeriiall::\ (Fig, 828; ¢,/.) Ordovicic.

Small, whorls embracing about one third, rounded laterally and
less strongly carinated than in preceding. Surface with spirals due
to regular emargination of lamelle.

Richmond group of Indiana, Ohio, Kentucky, and Minnesota.

XIX. BELLEROPHON Montfort. (Emend. Waagen.)

Subglobose, umbilicus mostly small or absent, dorsum rounded,
aperture generally expanded, usually with a callosity on the inner
lip. A central emargination and slit band or elevated blunt
(rarely noded) keel present; surface marked only by strong
growth lines, rarely by one or more rows of nodes. Ordovicic—
Permic.

52. B. troosti (d’Orbigny) Safford. (Fig. 829, a—c.) Ordovicic.

Fic. 829. a-c, Bellerophon troosti; d-g, B. platystoma (g, cross-section of
whorl). (After Ulrich, Pal. Minn. )

Whorls rounded, rapidly enlarging, flaring at lip; umbilicus
very small, sharp and deep ; dorsum with distinct rounded keel in
adult.

Trenton of Tennessee and Kentucky.

GASTROPODA

BELLEROPHONTIDEZ. 619

53. B. platystoma Meek and Worthen. (Fig. 829, d—g.)
Ordovicic.
Whorls subtriangular, gradually expanding to aperture, which
expands more rapidly ; umbilicus rather large.
Trenton (Galena) of Illinois and Minnesota.
54. B. exiguus Foerste. Siluric.
Small, umbilicus minute, lip expanding, emarginate aperture
subtrigonal, carina rounded; lines of growth strong.
Clinton of Ohio, Indiana. ,

55. B. pelops Hall. (Fig. 330.) Devonic.

Fic. 830. Lellerophon pelops, three views. (After Hall. )

Subglobose, non-umbilicate, aperture expanded, with moderate
sinus, and broadly rounded lobes on either side. Keel narrow,
sharp; lines of growth marked.

Schoharie and Onondaga of New York, Ohio, etc.

56. B. newberryi Meek. (Fig. 831, c.) Devonic.

Fic. 831. @, 6, Bellerophon propinguus ; c. B. newberryi.
(After Meek, Pal. Ohio, I.)

Smaller than preceding, less expanding; surface striz more
pronounced and rib-like. In the closely related B. propinguus
Meek (Fig. 831, a, 0), the striz are more crowded and the dorsal

_keel has a median impression. In worn specimens the keel in

both may be obsolete.
Columbus (Onondaga) limestone of Ohio.

620 NORTH AMERICAN INDEX FOSSILS.

57. B. nactus Hall. Devonic.
More abruptly rounded and with sharper keel; aperture less
abruptly expanded.
Chemung of New York and Pennsylvania.

58. B. sublavis Hall. (Fig. 832.) Mississippic—Carbonic

Fic. 832. Bellerophon sublevis. (After Whitheld, Bull. Am. Mus, Nat. Hist. )

Medium-sized, subglobose, non-umbilicate, with transverse aper-
ture and an extended thickened lip, with deep emargination and
low rounded dorsal carina. Surface smooth except for growth
lines, which, together with the carina, are often obsolete.

St. Louis and Chester groups of Indiana, Ilinois, Ohio, Missouri,
and Arkansas, and Lower Coal Measures of Pennsylvania.

59. B. crassus Meek and Worthen. (Fig. 833.)
Carbonic—Permic.
Large, subglobose, thick-shelled, slightly umbilicated, with nar-

SZ
oe INES @
NN in nh
Hibs VATE . :

Fic. 833. Bellerophon crassus. (After White, 13th Ind.)

row, prominent, subangular keel ; inner lip strong, spreading over

umbilicus ; surface with growth lines and fine wrinkles. '

Ee eee

Se eee eee eee eee eee eee

-

:
:

GASTROPODA—BELLEROPHONTIDZ. 621

Coal measures of Illinois, Indiana, Ohio, Pennsylvania, Arkan-
sas, Missouri, and Nevada ; Permic of Texas.

60. B. percarinatus Conrad. (Fig. 834, a—c, dS) Carbonic.
Medium-sized, rapidly expanding, non-umbilicated ; outer lip
laterally thickened ; dorsum with three rows of nodes, the median
one most prominent, the lateral ones dying out as ribs. A variety
with the lateral nodes obsolete occurs with this (Fig. 834, a—c).

Fic, 834. a-c, Bellerophon percarinatus var. 3B; d—f, B. percarinatus; g, h, Buca-
nopsis montfortianus. (After White, 13th Ind. Rep. and Bull. 77, U.S. G. S.)j

Coal measures of Nebraska, West Virginia, Pennsylvania, Ohio, .
Indiana, Illinois, Iowa, Missouri.

XX. Eupuemus McCoy. (Emend. Waagen.)

Closely involute, subglobose, Bellerophontid shells, not ab-
ruptly expanded, and with wide, but generally obscure band ;
inner lip with low parallel columellar folds or ridges, often extend-
ing as a thin covering over the greater part of the preceding whorl,
giving a part of the shell a strongly striate aspect. Carbonic—
Permic.

61. E. carbonarius (Cox). (Fig. 835, a-c.) Carbonic.

Small, globose, with broadly rounded dorsum, and transversely
compressed sublunate aperture, without expanded lip ; band ob-
scure, sometimes concave ; surface, except on final portion of last
whorl, with 18-25 strong revolving lines, nodose near the um-
bilicus. |

Coal measures of West Virginia, Ohio, Kentucky, Indiana,
Illinois, Iowa, Missouri, Kansas, Nebraska, Arkansas, and Texas..

62. E. nodocarinatus. (Fig. 835, d, ¢.) Carbonic.

622 NORTH AMEKICAN INDEX: FOSSILS;

Large, heavy, subglobose, slightly expanded aperturally, earlier
whorls as in preceding, final whorl carinate, with central depressed
band and another obscure ridge on each side.

Coal measures of Pennsylvania, Ohio, Indiana, Illinois, Iowa,
and Missouri.

63. E. subpapillosus White. Carbonic,
Like £. carbonarius but larger and with last portion of final

Fic. 835. a—c, Euphemus carbonarius,; d, ¢, E. nodocarinatus. (After White,
13th Ind.)

whorl studded with slightly raised papille in rows continuous with
the revolving ridges of preceding portion.
Upper Carbonic of Utah (Upper Aubrey group), of Colorado
and Arizona.
XXI. Bucanoprsis Ulrich.

|

:

;

Like Bellerophon, but surface cancellated by regular straight :
revolving and transverse strie. Ordovicic—Permic.
(A polyphyletic group, retained for the present.)

64. B. carinifera Ulrich. Ordovicic.

Fic. 836. Bucanopsis carinifera. (After Ulrich, Pal. Minn.) .

GASTROPODA—BELLEROPHONTID:. 623
Small, moderately embracing, gradually expanding whorls, with

rather abruptly expanding lip; slit band on flat-topped carina ;
revolving striz stronger than transverse.

Trenton of Kentucky, Lorraine of Ohio.
65. B. leda Hall. (Fig. 837.) | Devonic,

Aperture rapidly expanding,
rounded; slit not deep;

»

rh
ah
ad
ESTER
Z Z
Sb.
Lt

carina

revolving striz
alternating in size, sometimes fasciculate,

principal ones broad and rounded, trans-
verse striz fine.

Hamilton of New York, Ontario, etc.
66. B. lyra Hall.

Ted

a
aN
aX

yy)

SSS ONS

Fic, 837. Bucanopsis leda.

_ (Copy from Hall.)
Devonic.

Less ventricose than preceding and with less abruptly expanded
aperture ; carina elevated and revolving striz equal and firm.

Hamilton of New York, Falls of Ohio, etc.
67. B. keneni Clarke. (Fig. 838.)

Devonic.

Fic. 838. Bucanopsis keneni, <2. (After Clarke. )
Like &. /eda, but smaller, with less rapidly expanding lip and

surface strongly tuberculate, through accentuation of ornamenta-
tion of B. /eda type.

Portage (Styliolina limestone) of New York.

68. B, textilis Hall. (Fig. 339.) Mississippic.

- Fic, 839, Bucanopsis textilis, (After Whitfield, Am, Mus. Nat. Hist. Bull.)

624 NORTH: AMERICAD INDEX “FOSSILS.

Differs from 4. deda in its narrower band, less rapid expansion,
less pronounced umbilicus and finer striz.
St. Louis of Indiana and equivalent horizon of Nevada (?).

69. B. marcouana Geinitz. (Fig. 840.) Carbonic.

Like 4. leda, but with fine, regular,
simple striz and rather strong rounded
carina, transversely lined. Spirals on
band very fine.

Coal measures of West Virginia, Ohio,
Illinois, Missouri, Nebraska, and Arkan-
sas.

“as 70. B. montfortiana Norwood and
Fic. 840. Bucanopsis mar- _— Pratten. (Fig. 834, g, 4.) Carbonic.
Raat ne Shell non-umbilicate, small, but with
large expanded lip ; band in median depression from each side of
which extend large subnodose wrinkles to near the umbilicus,
except on the expanded apertural part. Surface with revolving
coarser and finer striz, which are somewhat nodose on the ribs.

Coal measures of West Virginia, Ohio, Indiana, Illinois, Lowa,
Missouri, Kansas, Nebraska, Texas, and Utah.

XXII. :Promatis Clarke.

Like Bellerophon, but with very rapid and broadly expanding
lip, which is sinuate in front, and without band; granulose callus
on inner lip, whorls narrowly umbilicate. Devonic.

71. P. patulus (Hall). (Fig. 841.) Devonic.

Fic, 841. Ptomatis patulus, (After Hall.)

Smooth, except for growth lines, which on earlier whorls are

strong and regularly costate ; callus granulate ; sinus very shallow.
s

GASTROPODA—BELLEROPHONTID:. 625

Hamilton of New York, Falls of the Ohio, Maryland, Virginia,
and Pennsylvania.

72. P. rudis (Hall). (Fig. 842.) Devonic.
Differs in having slight median angulation and strong concen-

Fic. 842. Ptomatis rudis, in different states of preservation, showing strize and strong
undulation, somewhat distorted. (Pal. N. Y., V.)

tric rugee on last whorl; radiating strize often seen between ruge.
Hamilton group of eastern New York, etc.

XXIII. PHracmostoma Hall. (Emend. Clarke.)
Differs from Ptomatis in having a narrow, sharply defined slit-
band, callus of inner lip thick, flattened, and wedge-shaped, but
does not form a true septum as in Carinaropsis. Devonic.

Fic, 843. Phragmostoma natator. (After Clarke. )

73. P. natator Hall. (Fig. 843.) Devonic.
Abruptly expanding lip, narrow deep sinus, surface with growth
lines and wrinkles only.
Portage (Naples) beds of New York, etc.

74. P. chautauque Clarke. (Fig. 344.) Devonic.
With more strongly pronounced narrower young whorls longi-
tudinally striate, smooth in adult, with narrow, sharp slit-band, and
abruptly expanding lip.
Portage (Naples) of New York.

626 NORTH. AMERICAN INDEX FOSSILS.

Fic. 844. Phragmostoma chautaugue, (After Clarke. )

XXIV. CARINAROPSIS Hall.

Patelliform shells with apex slightly enrolled in median plane,
aperture flaring, emarginate anteriorly; dorsal surface angular
medially ; a strong concave septum constricting the aperture below
the beak ; septum carinated on inner side. Operculum generally
present. Ordovicic.

75. C. carinata Hall. Ordovicic,

Gradually expanding from minutely enrolled apex ; faint anterior
sinus and strong dorsal carina.

Trenton of New York.

76. C. cunule Hall. (Fig. 845, a—c.) Ordovicic.

Fic. 845. a-c, Carinaropsis cunule, c showing sharp dorsal band ; d-g, C. cymbula.
J, g; a broken specimen showing septum; 4 and g, sections (0 = outline of operculum,
arb.). (After Ulrich, Pal. Minn. )

Dorsum faintly subcarinate, the carina often replaced by a slit-
band; septum broad, but slighty excavated.

Trenton of Tennessee and Kentucky.
77. C. cymbula Hall. (Fig. 845, a—g.) Ordovicic,
- Like the preceding, but septum deeply excavated on the outer,
and strongly carinated on the inner side. <a

Trenton of Kentucky, etc.

GASTROPODA—PLEUROTOMARID:. 627

XXV. PorcELLIA Leveille.

Widely umbilicated, often large shells, the adult whorls coiling
in a single planeas in Bellerophon, and with a dorsal slit and prom-
inent band. Inner whorls in a flat spire. Surface ornamented by
ribs or nodes.

78. P. crassinoda (White and Whit.). (Fig. 846.) Mississippic.

Fic. 846. orcellia crassinoda, two views of type specimen, X 1%. (After Weller,
St. Louis Acad. Sci. Trans., X.)

Very large, dorsum flatly rounded, very
broad, with well-marked narrow median slit
band; dorso-lateral angles coarsely nodose,
the nodes dying out towards the umbilicus.
Cross-section of whorls subtriangular, sur-

face with revolving and transverse lines.
Kinderhook of Iowa.

79. P. nodosa Hall. (Fig. 847.)
Mississippic.
Smaller, volutions more nearly rounded,
nodes sharper and more pronounced. ©
Kinderhook of Illinois, Burlington of Illinois and Missouri.

Fic. 847. forcellia no
dosa. (After Keyes. )

Family PLEUROTOMARIIDE d’ Orbigny.
XXVI. Rapuistoma Hall.

Flat-spired, umbilicated shells with close sutures and sharply
angular volutions of triangular section, without slit or band, but
with a shallow notch in the lip at the outer angle, and with the
lines of growth interrupted on the flat surface by a raised line and
curving forward on the body of the whorl. Ordovicic. |

80. R. striatum (Emmons). (Fig. 848, c, 2.) ~ Ordovicic.

628 NORTH AMERICAN INDEX FOSSILS.

Large and high with nearly flat spire, sometimes with early
volutions elevated; shoulder angle large, often 90°; umbilicus

Fic. 848. a, 6, Raphistoma stamineum ; c, d, R. striatum, (After Raymond. )

closed except in internal molds; surface with coarse rounded
striz or undulations.
Chazy of New York and Quebec (Aylmer sandstone).

81. R. stamineum Hall. (Figs. 848, a, 6; 849.) Ordovicic.

Fic. 849. Raphistoma stamineum. (After Hall.)

Large, central portion of spire slightly elevated above outer
volution; body of whorl ‘subventricose; shoulder nearly flat ;
angle sharp; striz rounded.

Chazy of New York.

82. R. planistrium Hall. Ordovicic.

Smaller than preceding, of greater proportional
height; shoulder slightly concave; striz flat,
Fig. ate Raphis- imbricating ; aperture narrow, trigonal; umbili-

12

tomina attleborough- cus sniall.

ensis,enlarged. ( After Chazy of New York.
Walcott, roth Ann. :
Wie e5 83. R. peracutum Ulrich and Scofield.

(Fig. 851, a—d.) Ordovicic.
Small, spire perfectly flat, shoulder angle very sharp ; umbilicus
above a fourth of diameter ; revolving line a third of the shoulder
width from the suture.
Black River of Minnesota.

»

GASTROPODA—PLEUROTOMARIIDZ. 629

XXVII. Rapuistomina Ulrich and Scofield.

Depressed conical, umbilicate, with sharply angular and carinate
whorls, the carina projecting over the moderately impressed suture ;
growth lines below carina at first curving backwards ; no notch or
band. Cambric-Ordovicic.

84. R. (?) attleboroughensis Shaler and Foerste. (Fig. 850.)
Cambric.

Minute, low-spired; shoulder whorls flat or faintly concave,
base of whorls rather flat, shoulder angle not very sharp.

Lower Cambric of Newfoundland? and eastern Massachusetts.

Fic. 851. a-d, Raphistoma peracutum \(a, X 1; 6, enlargement of surface; c, d,
<2): eg, Raphistomina lapicida; hj, Euomphalopterus valerius var. obsoletus
{After Ulrich and Scof., Pal. Minn. )

85. R. lapicida Salter. (Fig. 851, e-g.) Ordovicic.
Medium-sized, height of spire about equal to height of body of

last whorl; whorls embracing to angle except last one, which

occasionally falls below ; peripheral angulation sharp and carinate.
Black River of Canada and Tennessee.

XXVIII. EvoMPHALOPTERIS Roemer.

Trochoid or subtruncate, broadly umbilicated shells, with the
shoulder flat or concave and the body receding, the angle being

630 NORTH AMERICAN INDEX FOSSILS.

drawn out into a thin flat carina, which may be very broad and

entire or broken up into rude spines. Siluric.

86. E. valerius (Billings). (Figs. 851, 2,7; 852.) Siluric.
Shoulder angle drawn out into a broad hollow flange with com-

paratively smooth edge, and smooth base without revolving ridge

around the umbilicus.

Niagara of Waldron, Indiana, Guelph of Canada, Ohio, and

Fic. 852. Euomphalopteris valeria, Fic. 853. Zuomphatopteris elora ,

umbilical view. (After Whiteaves, Pal. apical view. (After Whiteaves, Pal.
Foss., TIT.) Foss., III.)

New York, and Upper Monroe of Michigan. |
87. E. elora (Billings). (Fig. 853.) Siluric.
Similar to preceding, but smaller and with the shoulder angle
drawn out into a series of flat spines.
Guelph of Ontario.

XXIX. ScALirEs Emmons.

Spirally coiled, with whorls embracing more or less strongly,
shoulder flat and horizontal, base of whorl drawn out into a short
anterior notch. Ordovicic.

88. S. angulatus Conrad. (Fig. $54, 2.) Ordovicic.
Spire forming about one half of the length of the shell, sutures
canaliculated, angle slightly acute, sides of whorl nearly perpen-
dicular ; shoulder with obliquely backward bending strie.
Chazy limestone of-New York, etc.

GASTROPODA—PLEUROTOMARIDE. 631

XXX. Ormospira Ulrich.

High-spired, of many rapidly enlarging volutions. Structure
as in Rhaphistoma, but with very loosely embracing whorls.
Ordovicic.

89. O. laticincta Ulrich. (Fig. 854, 4, c.) Ordovicic.

Large; angle between shoulder and body of whorl obtuse ;

Fic. 854. .a, Scalites angulatus; b, c, Ormospira laticincta, with enlargement of slit

band ; @, Ormospira alexandra. (After Ulrich, Pal. Minn. )

shoulder flat; striz interrupted near middle by revolving spiral, at
which they change from convex to concave.
Black River of Tennessee.

go. QO. alexandra Bill. (Fig. 854, 2.) Ordovicic.
With smaller apical angle and more rounded whorls than pre-
ceding.

Black River of Canada and Kentucky.

XXXI. LopHosprra Whitfield.

Shells with more or less elevated spires; close coiled whorls
except in senescent (phylogerontic) species. Whorls angular, gen-
erally with several carinze of which the central one forms a strong
keel and is marked by an obtusely rounded peripheral “ band’”’
which is often marked with spirals of which the central one is
heaviest. Umbilicus nearly always present. Outer lip notched
but without slit. Ordovicic-Devonic.

A. Lines of growth forming very slight or no peripheral reéntrant,

632 NORTH AMERICAN INDEX FOSSILS.

gli. L. rectistriata Raymond. (Fig. 855.) Ordovicic.
Distinguished by its small size, nearly straight lines of growth
and rather prominent carina beneath the periphery.

Fic, 855. Lophospira rectistriata, <4. (After Raymond. )

Common throughout lower and middle Chazy of the Lake Cham-
plain region.
92. L. bicincta (Hall). (Fig. 856, ad.) Ordovicic.

Shell 15 to 30 mm. high, with apical angle about 60°. Six
subangular volutions, the last ventricose-tricarinate, the lower carina
hidden in younger whorls. Notch in lip exceedingly shallow.
Growth lines sharp.

Stones River and Trenton group of Kentucky, Tennessee, Min-

Fic. 856. a-d, Lophospira bicincta ; e, f, L. quadrisulcata. (After
Ulr. and Scof., Pal. Minn. )

nesota, Illinois, Wisconsin, New York, and Canada. Also in the
Cincinnati group of Minnesota.

93. L. quadrisulcata Ulrich and Scofield. (Fig. 856, ¢, /)
Ordovicic.
Like ZL. dicincta, but with an additional carina and groove on
the body whorl, all grooves and carine being more pronounced.
Richmond group of Minnesota.

94. L. helicteres Salter. (Fig. 857.) Ordovicic.
Whorls bicarinate, intercarinal spaces concave; embracing to
lower carina except last whorl, which is free, and which has an
additional carina formed by the sutural margin.
Black River of Ontario, Kentucky, and Wisconsin.

a

GASTROPODA—PLEUROTOMARIIDE. 633

95. L. wisconsinensis Ulrich and Scofield. (Fig. 858.)
Ordovicic.
_ All except apical whorls loose-coiled and free ; carinz obsolete
towards lip.
Stones River of Minnesota, Wisconsin, and Illinois.
B. Lines of growth forming strong peripheral reéntrant, with >-shaped notch,

Fic. 857. Lophospira helicteres, last, non-coiling portion of large specimen and
nearly complete individual; s, sutural edge. (After Salter, Can. Organ. Rem.
aec., 1.)

96. L. perangulata Hall. (Fig. 859, a—c.) Ordovicic.
Small, embracing to within one half or two thirds the shoulder
width of the periphery, last whorl often free, shoulder slightly con-
cave; apical angle 50° to 70°; band prominent, trilineate ; lower
carina pronounced ; umbilicus small.
Stones River of Kentucky, Tennessee, Minnesota; Lowville of

. wile

Fic. 858. Lophospira wisconsinensis. (After Ulrich and Scofield, Pal. Minn.) >

| 634 NORTH AMERICAN INDEX FOSSILS.

New York and Ottawa River, Canada (“Black River’ group).
Chazy of New York.
97. L. acuminata Ulrich and Scofield. (Fig. 859, d.)
Ordovicic.
With sharper periphery and lower carina than preceding, more
numerous whorls and smaller apical angle ; no umbilicus.
Richmond group of Indiana, Ohio, and Minnesota.

Fic. 859. a-c, Lophospira perangulata; d, L. acuminata; e-h, L. medialis ; t—k,
L. pulchella. (After Ulrich, Pal. Minn. )

98. L. medialis Ulrich and Scofield. (Fig. 859, e-Z.)
Ordovicic.
Embracing to near periphery; apical angle 58° to ey lower
carina faint; umbilicus small.
Trenton a New York, Minnesota, Kentucky, Tennessee, and
Missouri.

gg. L. pulchella Ulrich and Scofield. (Fig. 859, 2-2.)
Ordovicic.
With well-marked subsutural carina, concave shoulder and
lower carina strong and obtuse; angle 50° to 56°; umbilicus
minute or closed.
Black River of Minnesota, Trenton of Kentucky. Variety with
smaller angle (50° to 46°) in Richmond of Minnesota.

100. L. oweni U. and S. (Fig. 860, a—c.) Ordovicic.
Subsutural carina broad and obscure; band thick, rounded;
shoulder less concave than preceding ; lower carina obsolete in
adult. |
Stones River and Black River groups of Kentucky and Min-
nesota, and a variety in Eden of Ohio.

GASTROPODA—PLEUROTOMARIIDZ. 635

101. L. ampla Ulrich. (Fig. 860, d, 2.) Ordovicic.
Broader than preceding (apical angle 70° to 80°); shoulder
with pronounced carina near suture.
Lorraine of Ohio and Kentucky; Richmond of Indiana and
Kentucky.

102. L. tropidophora Meek. (Fig. 860, #-/.) Ordovicic.

=

Fic. 860. a-—c, Lophospira oweni; d,e, L. ampla,; f-h, L. tropidophora, i, 7, L.
sumnerensis. (After Ulrich, Pal. Minn. )

Like the preceding, but without the upper carina.

Cincinnati group (Eden to Richmond) of Ohio, Kentucky, and
Indiana.
103. L. sumnerensis Safford. (Fig. 860, z, 7.) Ordovicic.

Body whorl large, vertical below periphery ; band prominent,
rounded ; shoulder concave; apical angle 60° to 73°; no acces-
sory carine.

Trenton of Tennessee, Kentucky, and Minnesota.

104. L. bowdeni Safford. (Fig. 862, a—c.) | Ordovicic.

High-spired ; apical angle 26° to 34 ° ; shoulder concave below,
convex near suture from obscure carina; band round, not prom-
inent ; lower carina faint or absent ; umbilicus covered by reflexed

lip.

636 NORTH AMERICAN INDEX FOSSILS.

Upper Nashville of Tennessee; Lorraine and Richmond of
Ohio, Indiana, and Kentucky.

105. L. augustina Billings. (Fig. 861.) Ordovicic.

Large, with 8 to 10 strong volutions, up to
120 mm. in height; apical angle 33° to 40°,
embracing to within two thirds shoulder width
of periphery (to within one third in var. smn-
nesotensis Ulrich and Scofield).

Quebec group of Newfoundland; Trenton
of Minnesota and Ottawa, Canada.

106. L. serrulata Salter. (Fig. 862, d, e, f.)
Ordovicic.

Very sharply carinate with intercarinal
spaces deeply concave; shoulder carina in
upper third, two nearly equidistant carinz on
body whorl ; final whorls generally free ; some

specialized varieties scarcely coiled.
Fic. 861. Lophes- Stones River beds of Minnesota, Wiscon-
; o : 2 . . . .
BPO AEs X18 in Illinois; Black River of Wisconsin, Ten-
(After Billings. ) , : f
nessee, and Ottawa River, Canada.
107. L. bispiralis (Hall). | Siluric,
Apical angle about 60°, whorls embracing so as to leave body-
space equal to one half or two thirds the shoulder width; band,

Fic. 862. a-c, Lophospira bowdent, d, e, L. serrulata,; f, L. serrulata var. laxa.
(After Ulrich, Pal. Minn. )

which is concave, bordered by raised line, and at the center of
the body whorl ; shoulder nearly flat, with median carina, strong
in young but faint in adult individuals. Emargination slight.

ae

GASTROPODA—PLEUROTOMARIIDE. 637

Guelph of Canada and New York, Upper Monroe of Michigan
and Canada.
108. L. adjutor (Hall). (Fig. 863.) Devonic.

Whorls of round aspect ; periphery depressed; band concave,
margined by two spirals ; shoulder and body carine nearer to pe-
ripheral band.

Onondaga of New York and Ohio.

109. L. trilix (Hall). (Fig. 864.) Devonic.

Fic. 863. Lophospira adjutor. Fic. 864. Lophospira trilix, <2. (Pal. N.
(After Hall, Pal. N. Y., V.) Vp)

Peripheral band tricarinate ; shoulder with strong median or
supra-median and sometimes faint sutural carine ; body with two
close set carinze crossed by later whorls; growth lines strong,
lamellose.

Hamilton of eastern New York, Pennsylvania, Maryland, etc.

XXXII. ScuizotopHa Ulrich.

Like Lophospira, but with the apertural notch prolonged into
a long slit with parallel edges.

110. S. moorei Ulrich. (Fig. 865.) Ordovicic.

Fic. 865. Schizolopha moorei ; a, \ateral, and 4, umbilical, view of internal mold Bid,
specimens with shell preserved. All x 24. (After Ulrich, Pal. Minn. )

Apical angle about 75° (more or less); whorls embracing to
within one half or one third shoulder width of the angle ; shoulder
and body free from spirals, gently concavo-convex ; slit occupying
about one fifth of length of last whorl.

Lorraine and Richmond of the Cincinnati dome region.

638 NORTH AMERICAN INDEX FOSSILS.

XXXII. PHANEROTREMA Fischer.

Turbinate shells with few rapidly enlarging whorls, developing
a shoulder angle in the later whorls, slit band deep on the angle
of the last whorls. Siluric-Carbonic.

111. P. occidens (Hall). (Fig. 866.)
Siluric.
Angle extending back through most
of the whorls, final coil somewhat
loose; shoulder flat but sloping, with
strong revolving spirals, cancellated
Fic. 866. Phanerotrema occt- by growth lines ; body of whorls
dens, < %%. (After Hall, 20th rounded.
Mus. Report. ) Niagara limestone of Wisconsin.

112. P. labrosa (Hall). (Fig. 867.) Devonic.
Large, last whorl very ventricose, angulation chiefly on last
portion of outer whorl, spirals strong on all parts of shell, can-
cellating lamellz strong.
Helderbergian (Becraft) of New York, etc.

113. P. grayvillensis N. and P. Carbonic,

Fic. 867. Phanerotrema labrosa ; a, b, opposite views of a specimen partly denuded
of the shell, & 2; ¢, enlargement of surface markings. (Pal. N. Y., III.)

Small, high-spired; volutions all angular, shoulder slightly
concave ; spirals strong.

Coal measures of West Virginia, Kentucky, Illinois, Indiana,
Iowa, Missouri, Nebraska, and Arizona.

GASTROPODA—PLEUROTOMARIIDZ. 639

XXXIV. WortTHENIA DeKoninck.

Conical, with whorls embracing part way to angulation, which
is pronounced and carries the slit. This extends back one third
or one fourth the length of the whorl; band regularly nodulated
or crenulated ; spirals well developed. Carbonic.

114. W. tabulata (Conr.). (Fig. 868.) Carbonic.

Fic. 868. Worthenia tabulata. (After White, 13th Ind. Rep. )

Large, exposed part of whorl below carina equalling width of
shoulder, and like it flat or slightly concave. Nodulated band
prominent; spirals more subdued. A second carina on body
whorl at level of suture.

Coal measures of Pennsylvania, Indiana, Illinois, Missouri, and
Texas. Also in Belgium.

as

Fic. 869. Worthenia subscalaris, opposite views. (After Meek and Worthen,
Illy; Palsy F1.)

640 NORTH AMERICAN INDEX FOSSILS.

115. W. subscalaris (Meek and Worthen). (Fig. 869.)
Carbonic.
Large ; early whorls embracing to near periphery, later showing
space below carina equal to shoulder. Lower carina strong ;
spirals and nodulations subdued.
Coal measures of Illinois and Missouri.

116. W. speciosa (Meek and Worthen). (Fig. 870.) Carbonic,

eo

Fic. 870. Worthenia speciosa; a, 6, opposite views, nat. size; c, enlargement of part
of surface. (After Meek and Worthen, Pal. Ill., II.)

Less than half the size of the preceding, of seven or more volu-
tions, whorls embracing to within half the shoulder width of the
carina ; slit-bearing angulation and lower carina strong ; shoulder
slightly concave, with growth lines strengthened at regular inter-
vals ; spirals numerous, fine.

Coal measures of Illinois, Missouri, and Oklahoma.

XXXV. Liosprra Ulrich and Scofield.

Pleurotomariod shells with low spire, subrhomboidal volutions,
which are flat, gently convex or slightly concave above, and not
infrequently angular at the edge of the umbilicus. The aperture
is deeply notched and the band is scarcely distinguishable. Ordo-
vicic,

117. L. micula (Hall). (Fig. 871, ad.) Ordovicic.

Small; whorls flattened and continuous in the spire, the suture
scarcely depressed. Umbilicus filled by reflex callosity of lip.

Trenton group of Kentucky; Eden and Lorraine (?) (Maquo-
keta) of Minnesota, Wisconsin, Illinois, Iowa, Ohio, and Ken-
tucky.

118. L. progne (Bill.). (Fig. 871, e-g.) Ordovicic,

Like Z. micula, but about twice as large or more.

Stones River and Black River beds of Canada, Kentucky, Ten-
nessee, and Minnesota. |

GASTROPODA—PLEUROTOMARIIDZ. 641

119. L. vitruvia (Bill.). (Fig. 871, 2-2.) Ordovicic.
Larger than preceding, with stronger, backward deflected lines
of growth and more strongly defined band. Umbilicus open and

Fic. 871. a-d, Liospira micula (d, surface enlargement); e-g, L. progne,; h-k,
L. vitruvia ( g and # = longitudinal ‘sections showing hollow axis). (After Ulrich
and Scof., Pal. Minn. ) ;

often a third of the diameter of the shell. Lower lip with tongue-
ike projections.

Stones River to Trenton ; Canada, New York, Tennessee, Ken-
tucky, Ohio, Indiana, Illinois, lowa, Wisconsin, and Minnesota.

120, L. americanus (Bill.). Ordovicic.
Differs from LZ. vtvuvia in more rounded lower lip, as shown by
lines of growth. Umbilicus wider and less abrupt and without
angulation.
In the Trenton limestones of eastern Canada, New York, Min-
nesota, and Manitoba ; Stones River and Black River of Tennessee.

Fic. 872. Liospira eugenia. (After Billings. )

121. L. eugenia (Bill.). (Fig. 872.) Ordovicic.
Shoulder convex near suture, concave near periphery ; periphery
elevated ; umbilicus closed.

642 NORTH AMERICAN INDEX FOSSILS.

Black River of Canada (Encampment d’Ours, etc.).
122. L. mundula Ulrich. (Fig. 875, a, 0.) Ordovicic.
Differs from L. eugenia in having shoulder wholly concave,
peripheral band high and obtuse, and umbilicus open.
Black River of Paquette’s Rapids, Canada; Trenton of Ken-
tucky.
XXXVI. Euconia Ulrich.
Subtrochiform shells with nearly flat base and regular conical
spire, the suture scarcely depressed, the
base umbilicated; band on upper side of
peripheral edge, mouth subquadrate. Or-
dovicic—Siluric.
123. E. ramsayi (Bill.). Ordovicic.
Of medium size, regularly conic and with
small umbilicus.

Fic. 873. Auconta etna:
A small specimen.
Beekmantown of Canada.

124. E. etna (Bill.). (Fig. 373.) Ordovicic.
With wide umbilicus ; often large (2 in. in basal diameter and
nearly same in height).
Beekmantown of Newfoundland.
125. E. (?) pervetusta (Conrad). (Fig. 874.) Siluric.

Fic. 874. Luconia pervetusta.

Small, with gently convex whorls (about four) embracing to
ambitus or beyond ; umbilicus large and deep, extending to apex.
Medina of New York.

XXXVII. Eoromaria Ulrich and Scofield.
Depressed-conical pleurotomarioids, characterized by a notch
but not a slit, and with the band onthe upper side of the periph-
ery ; surface with simple lines of growth. Ordovicic—Siluric.

126. E. dryope Bill. (Fig. 875, c—e.) Ordovicic. _

GASTROPODA—PLEUROTOMARIIDE. 643

Shoulder convex near suture, concave near band; coiling some-
times slightly loose ; umbilicus moderate.
Stones River of Minnesota; Black River of Tennessee.

127. E. vicina Ulrich and Scofield. (Fig. 875, 7) Grdaticic:

Fic. 875. a, 6, Liospira mundula ; c—e, Eotomariu dryope; f, E. vicina.

Like the preceding, but with shoulders flat, forming a cone
equal in height to body of last whorl.
Stones River of Minnesota and Wisconsin.

128. E. supracingulata (Bill.). (Fig. 876.) Ordovicic.

Fic. 876. Lotomaria supracingulata, three views, < 24. (After Ulrich, Pal. Minn.)

Large; whorls not embracing to periphery ; shoulders gently
convex ; notch deep; umbilicus large.

Stones River and Black River of Illinois, Wisconsin, Michigan,
and Minnesota; Pogonip group of Nevada (?).

129. E. areyi Clarke and Ruedeman.

Siluric.
Large and robust, with nearly flat shoul- __-“
ders, a prominent band, and the sides of the \ \
body whorl nearly vertical. beg
In the Guelph of Canada and New York; SS
Upper Monroe of Michigan. Fic. 877. Hotomaria
130. E. galtensis (Bill.). (Fig. 877.) 7 NE rg
Siluric, |

Depressed conic, apical angle about 100°, shoulders nearly flat,
whorls embracing to ambitus, body portion receding, making
ambital angle often less than 90° ; growth lines recurving, some-
times strong on upper surface.

644 NORTH AMERICAN INDEX FOSSILS.
Guelph of Canadaand New York; Upper Monroe of Michigan.

XXXVIII. CLatHRospirA Ulrich and Scofield.

Distinguished from Hotomaria by a delicate cancellated surface
sculpture, and concave vertical band onthe periphery. Ordovicic—
Devonic (?).

131. C. subconica(Hall). (Fig. 878, ac.) Ordovicic.

Volutions flattened above and embracing nearly to the periph-
ery of the preceding, under side rounded; band sharply defined,
covered by succeeding whorls ; surface marked by spiral and simi-
lar cancellating growth lines.

Stones River and Black River groups of Minnesota, Wisconsin,

Fic. 878. a-c, Clathrospira subconica,; d-f, C. conica. (c, f enlargement of sur-
faces.) (After Ulrich and Scofield Pal. Minn.) .

Illinois, Kentucky, and Tennessee; Black River and Trenton of
Canada and New York. Also doubtfully in the Cincinnati group
of Ohio, Indiana, and Kentucky.

132. C. conica U. and S. (Fig. 878, 7) Ordovicic.
Smaller; shoulder concave or flat, body concave below ‘pe-
riphery, the concavity bounded below by an angulation or faint
carina.
Black River and Trenton of Minnesota ; Trenton of Kentucky
and Lorraine of the Cincinnati region.

XX XIX. Euryzone Koken.

Round-whorled Pleurotomarias, sometimes with slightly flat-
tened shoulder and with a slit band near the middle of the whorl
often covered by the margin of the succeeding whorls. Band
concave, flat or rarely convex; surface with fine revolving striz

tah

GASTROPODA—PLEUROTOMARIIDEZ. 645

cancellated by lines of growth, rarely smooth. Umbilicus variable.
Devonic.
133. E. ruguilata (Hall). (Fig. 879, 2.) Devonic.

Last whorl greatly expanding ; revolving striz faint, generally
not preserved ; band broad, concave, generally showing on all
volutions; slit moderate.

In the Agoniatite limestone horizon of the Marcellus of eastern
North America ; also in the Hamilton group (?) of New York.
134. E. itys (Hall). (Fig. 879, 4.) Devonic.

Higher spire than preceding, volutions regularly expanding,
band narrow, partly covered by succeeding whorls ; revolving striz
equal to transverse or stronger, often nodose from cancellation.

>

ZW
SOY

Fic. 879. il rugulata, X 2; E. itys, xX 24; E. lucina, XK 4%. (Copies

from Hall. )

Hamilton beds of New York, Maryland, and Virginia, and
representative form at Falls of the Ohio.

135. E. (Pleurorima) lucina (Hall). (Fig. 879, c.) Devonic.

Large; whorls rather more compressed vertically than in pre-
ceding, and regularly and more rapidly enlarging; band wide,
crossed by succeeding whorls except in senile individuals ; revolv-
ing striz equal to or fainter than transverse.

Onondaga and Hamilton of western New York and Falls of the
Ohio.

XL. SpPrroRAPHE Perner.

Umbilicated pleurotomarioids of depressed-rounded whorls, with
profound suture and subquadrangular section. Band above suture
throughout, forming strong, convex or flat spiral. Growth lines
strong, often elevated, strongly reflected backwards. Spiral sculp-
ture absent. Ordovicic—Devonic.

136. S. arata Hall. (Fig. 880.) Devonic.

Whorls depressed; moderate spire and deep sutures; body
whorl ventricose toward aperture; umbilicus not large; surface

646 NORTH AMERICAN INDEX FOSSILS.

with strong, often elevated transverse striz ; increasing by inter-
calation in last whorl.
Schoharie grit and Onondaga of New York, etc.

XLI. Mourtonira DeKoninck.

Umbilicated pleurotomarioids, with body of whorl large, shoulder
more or less flattened, forming conical or discoidal spire; band

Fic. 880. Spiroraphe arata. (After Fic. 881. Mourlomia mississippien-
Hall.) sis. (After Meek, Pal. Ohio, IT.)

heavy just above the ambitus; surface with spirals cancellating
the growth lines. Mississippic—Carbonic.

137. M. mississippiensis (Wh. and
Whit.). (Fig. 881.) Mississippic.
With nearly flat shoulders; whorls

embracing to ambitus, generally cover-

ing band of preceding whorl.

_ Kinderhook of Iowa; Waverly of

Ohio.

XLII. Gyroma Oehlert.
Round-whorled pleurotomarioids or-
Fic. 882. Gyroma capilla- namented by revolving spirals and trans-
ra, -(Atter Hall.) verse ridges. Band above the middle
Devonic.

«
q

:

GASTROPODA—PLEUROTOMARIIDE. 647

138. G. capillaria (Conrad). (Fig. 882.) Devonic.
Turreted, with deep suture, 2-3 strong spirals above the con-

cave band, which is also bound by spirals ; aperture subrhomboidal.
Hamilton of New York.

XLIII. Bemsexia Ocehlert.

Depressed subconical shells with angular volutions and concave,
vertical or oblique band, situated on the periphery, with a slit about
one fourth volution in length ; surface strongly striate. _Devonic—
Mississippic. |
139. B. sulcomarginata (Conrad). (Fig. 883.)

; Devonic—Mississippic.

Moderately high-spired ; volutions embracing to base of band ;

Fic. 883. Bembexia sulcomarginata. (After Hall. )

shoulder with two revolving ridges, one below the suture and one
near periphery ; growth lines strong, regular, even, and lamellose.
Suture often canaliculate ; body rounded, with a faint carina below
the band.

Hamilton of New York, Maryland, Virginia, and Falls of the
Ohio ; Bedford and Berea of Ohio.

XLIV. Evuconosprira Ulrich.

Almost regularly conical shell with nearly flat (concave or
slightly convex) base, with flat shoulder, except in the young ; slit
covers from a third to a fourth of the last volution, with concave
band between sharply elevated lines; fine spirals on the later
whorls. Mississippic-Carbonic.

140. E. turbiniformis M. and W. (Fig. 884, 2,4.) | Carbonic.

With slightly convex base and small umbilicus bordered by ob-
scure ridge ; surface cancellated by fine spirals and oblique growth
lines.

648 NORTH AMERICAN INDEX FOSSILS.

Coal measures of Illinois, Indiana, and Missouri.

XLV. Treposrira Ulrich and Scofield.

Early whorls rounded, later with flat shoulder embracing up to
the peripheral angulation ; no umbilicus, slit short, band wide and
concave ; sutural edge of later whorls nodose. Devonic—Carbonic.
141. P. rotalia Hall. Devonic.

Shoulder of last whorls gently convex, nodes faint.

Hamilton of New York.

142. P. spherulata (Conrad). (Fig. 884, c, df) Carbonic.

Shoulders flat or slightly concave ; nodes prominent.

Fic. 884. a, 6b, Euconospira turbiniformis ; c, Trepospira spherulata; d, e, T.
spherulata var. a; f, var. B; g, 7. tllinotsensis. (a-e, after White, 13th Ind.; / g,
after Ulr. and Sc., Pal. Minn. )

Coal measures of the Alleghanies, Indiana, Illinois, Iowa, Mis-
souri, Kansas, and Texas.

143. P. illinoisensis (Worthen). (Fig. 384, g.) Carbonic.

Smaller than preceding and more depressed, with greater apical
angle ; nodes smaller, round, separated by more than their
diameter.

Coal measures of Kentucky, Iowa, Illinois, Missouri, and
Arkansas.

Family MURCHISONIDZ: Koken.
XLVI. Hormotoma Salter.

Shell elongate, consisting of from 8 to 14 rounded or subangular
whorls, the outer lip with a broad and deep V-shaped notch, but
no slit. Band near the center generally obscure, marginated on

|

.

:

|

4

each side by a delicate raised line. Ordovicic—Devonic.
2

el

GASTROPODA—MURCHISONIDEZ.. 649

144. H. gracilis (Hall). (Figs. 885, a-d; 886, a—-d.) | Ordovicic.
Slender, small, and rather loosely coiled, the whorls embracing
very little, generally rounded or slightly angulated.
A number of varieties have been recognized, one or another of
which occurs in most of the Trenton and Lorraine localities in

Fic. 885. «@, Hormotoma gracilis, Fic, 886. a, Hormotoma gract-
typical form; 4, var. sublaxa; c. lis, part of fig. a enlarged; 4, var.
var. multivolvis,; d, var. angusta. sublaxa, part of 6 enlarged, 2,

c, another specimen of same, < 2 ;
d, var. angusta, X 2.

eastern United States and Canada. It ranges as far down as the
Stones River group, and into the Chazy of Lake Champlain.
145. H. salteri Ulrich. (Fig. 887, ¢, @.) Ordovicic.

Fic. 887. a, Hormotoma bellicincta, b, H. trentonensts ; ¢, d, H. saltert.
(After Ulrich, Pal. Minn. )

Large, and with greater apical angle than A. gracilis ; whorls
embracing to two thirds or less shoulder width ; faint subsutural
band present.

Black River of Paquettes Rapids, Canada (var. canadensis) and

650 NORDEA AMERICAN INDEX FOSSILS.

Tennessee (var. tennesseensis); Trenton of Kentucky (also var.
nitida).
146. H. bellicincta (Hall). (Fig. 887, a.) Ordovicic.
Stout, with rapidly enlarging whorls, whose
diameter is about twice their height; apical
angle 42° to 50°; small umbilicus and flat
band.
In the Trenton limestone of New York and
Canada; also in Minnesota, etc. A great
number of forms have generally been identified

with this species, the M/urchisonta bellicincta of
Hall.

147. H. trentonensis U.and S. (Figs. 887,
Bs BSS." ) Ordovicic.
Longer and more slender than preceding,

apical angle averaging 35°. Commonly con-

j founded with A. dellicincta Hall.

Pa es ot oe Occur generally as internal moulds in the
ma trentonensis. (After Trenton limestone of New York and Canada.
Ulrich and Scof., Pal. Also in Minnesota and Illinois, Kentucky,
Minn. )

and Tennessee, though rarely.

148. H. major (Hall). (Fig. 889.) Ordovicic.
Large, apical angle about 25°; generally preserved as internal

molds. In these the suture is deep, with an angulation on the

upper side of the whorl and a flat space beyond this. In the shell
the whorls embrace far up on the preceding one.

Trenton (Galena) of Minnesota, Wisconsin, Iowa, Missouri,
Dakota.

149. H. subcarinata Grabau. Siluric.
Differs from H. sa/tert in its looser coiling, the exposed body of
whorl being often half again as wide as the shoulder and bearing
a faint indication of a lower spiral.
In the upper Monroe of Michigan, Ohio, and Ontario.
150. H. desiderata Hall. (Fig. 890.) Devonic.
Large, slender, embracing to within one half or two thirds the
shoulder width; shoulder flat above, gently convex near band,
which is flattened or slightly concave.
Onondaga of Falls of Ohio and New York (?).

GASTROPODA—MURCHISONIDE. 651

Fic. 889. Hormotoma major, x 2%. (After Ulrich, Pal. Minn.)

151. H. (Hormotomina*) maia (Hall). (Fig. 891.) Devonic.

Whorls embracing more strongly, shoulder more convex, lines
of growth strong ; a faint carina close to the suture and another
in the middle of the band. Onondaga limestone of Ohio.

Fic. 890. Hormotoma desiderata, natural Fic. 891. Hormotoma ( Hormoto-
size and part of a whorl enlarged. (After mznza) maia, natural size and a single
feat, Fal. N. Y., V.) whorl enlarged. (After Pal. N.Y.,V.)

652 NORTH AMERICAN INDEX FOSSILS.

XLVII. Ca:tipium Clarke and Ruedemann. © (Celocaulus,
Oehlert.)

Differs from Hormotoma in greater length and more numerous
depressed whorls and perforated axis, small umbilicus and rounded,
not produced aperture. Ordovicic—Devonic.

152. C. linearis (Bill.). Ordovicic.

More strongly embracing than the next, suture almost obliterated.

Beekmantown of Mingen Islands.

153. C. oehlertiU. andS. (Fig. 893, a, 0.) Ordovicic.

Fic. 892. Celidium macrospira, longitudinal section, showing perforate axis, and
two more or less complete shells, showing form and surface character. (After Clarke
and Ruedemann, Mem. N. Y. State Museum, V.)

Of numerous (30 ?) closely embracing compressed whorls, mak-
ing an apical angle of 12°.

Galena of Illinois.
154. C. macrospira (Hall). (Fig. 892.) Siluric.

Large, apical angle 20° to 25°, early whorls embracing to within
one half shoulder width or less, later ones to two thirds shoulder
width or wider; periphery subangular with faint band; surfaces
above and below gently convex.

Guelph of Canada, New York, Wisconsin, etc.

————

OO ees

:

GASTROPODA—EUOMPHALIDZA. 653

XLVIII. Sorenospira Ulrich.

Small shells differing from Hformotoma in the small apical angle,
the compressed character of the whorls, the surfaces of which
are mostly flattened and divided by a prominent median band, de-
pressed between sharp spirals, with or without other ridges ; mouth
without slit. Ordovicic—Mississippic (?).

155. S. prisca (Bill.). (Fig. 893, c.) Ordovicic.
Apical angle about 14°; shoulder ;

and body flat or gently concave ; band

wide, carinze prominent, a third carina

below the periphery, covered by later
whorls.

Beekmantown of Mingen Islands ;
Stones River of Minnesota, Wisconsin,
and Tennessee.

156. S. pagoda (Salter). (Fig. 893, &
d, ¢.) Ordovicic. Fre, 893. a, 4, Celidium ochl-
Differs from the preceding in having ert: , c, Solenospira prisca; d, S.

an additional carina just below the 428942; ¢, enlargement of part of

suture, the lower carina also being sc ini papa: Sse
commonly visible above the suture.

Black River of Minnesota and Canada.

157. S. minuta (Hall). Siluric.
Minute, apical angle about 17°, shoulder and

body gently concave; carinz only two, sharp and

3 margining the Herth band.

A Manlius limestone of New York ; Lower (and

€ Upper ?) Monroe of Michigan.

Fie. Sos. 158. S. (?) turritella (Hall). (Fig. 894.)
Solenospira ? Mississippic.

furritella.( After Small, slender, with narrow shoulder and two or
Galea ons more spirals below the band.
Bull. ) a St. Louis (Spergen) of Indiana.

Family EvompHALip#@ de Koninck.
XLIX. STRAPAROLLINA Billings.
Shell small, spirally coiled, spire low, whorls rounded, umbilicus
of moderate width. Cambric—Ordovicic.

654 NORTH AMERICAN INDEX: FOSSILS.

159. S. remota Bill. (Fig. 895, a, 0.) Cambric.
Small, with low spire of three whorls sometimes slightly angular

at outer margin; height 4.5 to 6.75 mm., width 6.75 to 9 mm.
Lower Cambric (Etcheminian) of Newfoundland and eastern

Massachusetts.

160. S. primeva (Bill.). (Platyceras primevum Bill.) (Fig.
895, ¢.) Cambric.
Minute ; spire depressed ; last whorl partly free. (Some spec -

Bi it @
Fic. 895. a, 6, Straparollina remota, c, S. primevum. (After Walcott, roth Ann.
Rep.U. SGls: }

mens show deep dorsal sinus, while others appear to be without
it (Massachusetts). These may represent distinct groups of
phylogerontic shells in which the power to coil becomes obsolete.)

Lower Cambric (Georgian) of Quebec, and Troy, N.Y. Etch-
eminian of eastern Massachusetts.

L. STRAPAROLLUS Montfort.

Shells varying from broadly turbinate to discoidal, with rounded
whorls without sinus, and with broad umbilicus. Siluric(?)—Jurassic.

161. S. clymenioides Hall. (Fig. 896.) Devonic.

5
“ ATRL
ARISES)

Fic. 896. Straparollus clymenioides. Fic. 897. Straparollus rudis, K %.
(Alter Tat N. Y:; V¥.) (Copy from Hall. )

Four to five gently enlarging volutions almost in same plane,
slightly compressed ; diameter 1 to 2 inches.
Schoharie of New York ; Decewville of Canada.

162. S. rudis Hall. (Fig. 897.) Devonic.

GASTROPODA—EUOMPHALIDE. 655

More rapidly enlarging ; volutions less rounded below;; strize
often fasciculate and irregular.
Hamilton of New York.

163. S. cyclostomus Hall. (Fig. 898.) Devonic

Fic. 898. Straparollus cyclostomus. (After Hall, Geol. Iowa, I., 2.)

Low-spired, of five or six round, gradually increasing smooth
volutions with circular aperture.
Hamilton of Iowa.

164. S. hecale Hall. Upper Devonic.
Similar to S. rudis, but with the whorls more gently enlarging.
Chemung of New York and Pennsylvania.

165. S. ammon Wh. and Whitf. (Fig. 899.)

Mississippic.
Small; whorls round, rising but little above plane Fic. 899.
of volution. Straparollus
Kinderhook and Burlington of Iowa and Missouri ; on eae
also western New York.

166. S. planispira Hall. (Fig. 900, a, 0.) Mississippic.

FIG, 900. a, 6, Straparollus planispira ; c-e, S. spergenensis. (After Whitfield, Am.
Mus. Nat. Hist. Bull. )

Small, with flat or scarcely concave spire of 5 or 6 slender, very
gradually enlarging, rounded, smooth volutions.
St. Louis beds of Indiana.
167. S. spergenensis Hall. (Fig. 900, c-e.) Mississippic.
Early whorls flat, later slightly depressed, umbilicus deep.
St. Louis of Indiana and Missouri.

656 NORTH AMERICAN INDEX FOSSILS.

LI. PHANERoTINUS Sowerby.

Like Straparodlus, but with the whorls disconnected, forming an
open spire. Devonic—Carbonic.

168. P. laxus Hall. (Fig. go.) Devonic.
Whorls round, gently enlarging in very loose
spiral almost in same plane.
Onondaga and Hamilton of New York.

169. P. eboracensis Hall. (Fig. 902.)
P Devonic.

Fic.go1. Phanero- ike Straparollus rudis, but loose-coiled, often
4inus laxus. (After

Hall. )

showing scars of attachment of foreign objects.
Hamilton of New York.

170. P. paradoxus Winchell. (Fig. 903.) Mississippic.

Fic. 902. Phanerotinus eboracensis. (After Fic. 903. Phanerotinus para-—
Hall, Pal. N. Y., V.) doxus. (After Hall, Pal. N.Y.,V.)

Like P. /axus, but the inner whorls depressed below plane of
outer, and less loosely coiled.
Kinderhook—Burlington of Iowa and Missouri.

LII. OpyiLtetTa Vanuxem.

Shells with depressed spire and flat base, consisting of narrow
whorls which enlarge very slowly and are in contact throughout.
They are flattened or gently convex on the under side, and have a
faint lower and stronger upper keel, the latter ending in a deep
>-shaped apertural notch. Ordovicic.

171. O. complanata. (O. compacta Salter.) (Fig. 904.)
Ordovicic.
Of numerous whorls, flat on the lower and strongly concave on
the upper side, outer face flat and nearly vertical, upper surface
sharply keeled. Diameter 1 to 1% inches.

657

GASTROPODA—EUOMPHALIDZ.

In the Beekmantown (and Upper Potsdam ?), widely distributed
Also European.

throughout North America.

Umbilical (6) and upper view; @, outer keel; d,

Ophileta complanata.
(After Salter, Can. Org. Rem., Dec., I.)
Ordovicic.

FIG. 904.
inner angle,
172. O. bella Bill. (Fig. 905.)
* Whorls more rounded than preceding, basal portion less flat,
spire less sunken, fewer whorls, upper keel nearly central ; growth

lines coarse, subsquamose.
Div. P, Quebec group, Newfoundland.

\\\h :
eS aiid
S i See
Fic. 905. Ophiteta bella. (After Billings. )
LIT. Opuiretina U. and S.
Like Ophileta, but with a distinct slit-band on the upper carina.
(Fig. 906, a, 6.) — Ordovicic.

173. O. sublaxa U. and S.

Small, flat above, concave below (reversed in var. depressa), final
whorl free ; upper surface with two, outer with one median carina,

a fourth at the baso-lateral angle.
Stones River of Minnesota, Wisconsin, and Illinois ; varieties

in Tennessee and Trenton of Minnesota.

658 NORTH AMERICAN INDEX FOSSILS.

LIV. Eccytioprerus Remele. ~

Contiguous or disconnected whorls with the structure of Ophileta
but with the upper carina drawn out into a thin vertical “collar,”
which is not always preserved. Ordovicic.

174. E. beloitensis U. and S. (Fig. 906, c-e.) Ordovicic.

Rapidly enlarging, whorls in contact, coiling nearly in same
plane, outer surface convex, moderately high collar.

Stones River of Wisconsin and Kentucky.

Fic. 906. a, 4, Ophiletina sublaxa (6, enlargement of surface); c-e, Eccyliopteris
beloitensis; f, g, E. owenensts (g=section); 2, 7, Helicotoma planulata,; 7, k, H.
tennesseensis. (After Ulr, & Sc., Pal. Minn. ) ;

175. E. owenensis Meek and Worthen. (Fig. 906, f, g.)
Ordovicic.
Smaller, with the sides flat, and the collar, when preserved, very
high and thin.
Galena (Trenton) of Minnesota and Illinois.

LV. HeEticotoma Salter.

Differs from Ophileta in having a low spire rising above the
outer volution, a deep umbilicus, and the whorls rounded on the
under side. The carina is generally high and sharp. Ordovicic—
Devonic (?).

176. H. planulata Salter. (Fig. 906, 4, z.) Ordovicic.

With three to six strong, simple or double spirals on the outer
side of the whorls. |

_

GASTROPODA—EUOMPHALIDE. 659

Black River of Paquettes Rapids, Canada; Trenton of Mis-
sourt; Stones River of Illinois (var. vobusta). A somewhat lower-
spired form, with wider and shallower umbilicus, deeper notch, and
fainter spirals (/7. umdilicata U. and S.) occurs in the Stones River
of Minnesota, Wisconsin, and Illinois.

177. H. tennesseensis Safford. (Fig. 906, 7, £.) Ordovicic.

Like the preceding, but without the spirals; suture slightly
canaliculate.

Very abundant in lower Stones River of Tennessee, also in Black
River; Stones River and Black River of Kentucky. (//. planul-
atoides Ulrich.)

LVI. PLevronotus Hall.

Shells with flat or concave spire and broad, shallow umbilicus ;

_apertural notch deep; a distinct

revolving band present. Siluric(?)

—Devonic.

178. P. decewi Billings. (Fig.
907.) Devonic.
Large, spire flat or gently con-

cave, of three or four volutions,

periphery in adult flat and sepa-
rated from the upper surface by

a strong carina. Fic. 907. Pleuronotus decewi. (After
Onondaga of New York, Can- Hall.)

ada, Ohio, Michigan, and elsewhere.

LVII. Evompuatus Sowerby.

Shells with flat or low spires, angulate and carinate above, but
without marked notch as in Pleuronotus. Young like Straparollus.
‘Carbonic.

179. E. latus Hall. (Fig. 908.) Mississippic.

Of about four or five volutions, spire very little elevated, upper
surface obliquely flattened inside of carina, outer margin angulate
and subcarinate; inner abruptly elevated and somewhat carinate
at suture line ; base broadly umbilicate.

Burlington of Iowa, Illinois, Missouri; Waverly of Ohio.

180. E. similis M. and W. (Fig. go9.) Mississippic.

Small, subdiscoidal, spire flat in var. A/anus, otherwise slightly

660 NORTH AMERICAN INDEX FOSSILS.

elevated ; angulation nearly median as viewed from above. Diame-
ter one third inch or less.

Fic. 908. Luomphalus latus. (After Keyes. )

St. Louis of Illinois; Maxville of Ohio; Batesville of Arkansas.
181. E. planidorsatus M. and W. (Fig. gio.) Mississippic.

Fic. 909. LEuomphalus similis. (After Whitfield, N. Y. Acad. Sci. Trans. )

Similar to the preceding but about an inch in diameter; angu-
lation somewhat nearer to periphery.
Chester of Illinois, Missouri, etc.

Fic. 910. LEuomphalus planidorsatus. (After Meek and Worthen, Pal. Ill., II.)

182. E. pernodosus M. and W. (Fig. 911.) Carbonic.
Large, up to two inches in diameter. Spire flat, shoulder

*

GASTROPODA—EUOMPHALIDZ. 661

strongly concave, outer margin angulated, lower with row of blunt
nodes.
Coal measures of Illinois, Iowa, Missouri, and Arizona.

183. E. catilloides Conrad. (£. subrugosus M. and W.) (Fig.
QI2.) : Carbonic.

Fic. 911. Euomphalus pernodosus, upper side, profile and under side, K 24. (After
Meek and Worthen, Geol. I11., V.)

Rather small, strongly carinate both above and below, carinz
subrugose ; base rounder, wider than shoulder; outer portion of
whorl depressed below carina.

Coal measures of Indiana, Illinois, Iowa, Kansas, Missouri,
Nebraska, Eureka district; Nevada.

Ps ae

vy

Fic. 912. Euomphalus catilloides. (After White, 13th Ind. Rep.)

184. E, subquadratus M. and W. (Fig. 913.) Carbonic.
Up to an inch or more in diameter ; upper carina strong, nodose ;

Fic. 913. Zuomphalus subquadratus. (After Meek and Worthen, Ill. Geol., v5)

662 NORTROAMERICAN INDEX FOSSILS.

lower less strongly marked; a third carina on outer, nearly flat
portion of whorl, nearest to upper carina. Otherwise as in the
preceding.

Coal measures of Ohio, Illinois, Missouri, Arkansas, Texas.

LVIII. Caraurors Whitfield.

Inner whorls forming a low spire, embracing up to the angula-
tion, which is pronounced ; last whorl free and becoming straight.
Ordovicic.

185. C. lituiformis Whitf. (Fig. 914.) Ordovicic.

Fic. 914. Calaurops lituiformis, two views with cross-section, K %. (After
Whitfield, Bull. Mus, Comp. Zodl. )

Inner portion of about two and one half volutions, depressed-
convex to flat; angulations less pronounced on free whorls, which
curve toa larger radius and then grow straight. Surface with
coarse wrinkles alternating with finer growth lines.

In the Upper Beekmantown or Ft. Cassin beds of ih Lake
Champlain region.

LIX. EccytiompHarus Portlock.
Shells of loose coiled or disjointed spirals in a plane, like Phane-
rotinus, but with a well developed though shallow apertural notch,
and more or less strong upper keel. Ordovicic-Devonic (?).

GASTROPODA—EUOMPHALIDEZ. 663

186. E. distans Bill. (Fig. 915.) Ordovicic.
A loose, regularly spiral coil of two or more slender whorls,

separated by about once and a half their diameter; upper side

carinate, others rounded.
Quebec group (Beekmantown) of Newfoundland.

Fic. 915. Lccyliomphalus distans, lower side. (After Billings. )

187. E. undulatus Hall. (Fig. 916.) Ordovicic.

Whorls more distant and more rapidly increasing than in the
preceding ; section subtriangular or ovate-triangular, a broad sinus
in the upper lip. Surface often indented from attachment of
foreign objects. Inner whorls often cut off by imperforate septa.

Stones River of Minnesota, Wisconsin, Illinois, and Tennessee.

Fic. 917. LZecyliomphalus triangulus, in-
ternal mold, showing the collar but faintly.
(After Ulrich, Pal. Minn. )

Fic. 916. LZccyliomphalus undu-
jatus. (After Ulrich and Scof., Pal.
Minn. )
Ordovicic.

188. E. triangulus Whitf. (Fig. 917.)
Very loose coils, one and one half volutions rather rapidly en-

larging ; keel sharp and prominent, often forming a collar, upper

664 NORTH AMERICAN INDEX FOSSILS.

surface concave, lower rounded ; notch moderate. (This parallels
Eccithopterus in the development of the high collar, and some
place it in that genus.)

Beekmantown of New York, Vermont, and Canada.

LX. Macrurea Leseur. (aclurites Leseur.)

Shell a left-handed or sinistral coil of few rapidly enlarging
whorls, the spire flat, and the base somewhat prolonged and
umbilicated. Ordovicic.

189. M. magna Leseur. (Figs. 918, 918, A.) Ordovicic.

Fic. 918. MJaclurea magna, ~ 24. (After Halil. )

Large, of about six whorls, obtusely angular at outer edge,
breadth more than twice the height; upper surface of whorls
gently convex; operculum long, parallel-sided with nucleus in
center of upper side. _

Chazy (middle) of New York, Virginia, Kentucky, Michigan,
and other southern and western localities.

190. M. bigsbyi Hall. (Fig. 919.) Ordovicic.

Medium-sized, diameter about twice the height. Umbilicus
large and abrupt, exposing about half of each of inner whorls.

Growth lines cancellated on periphery by revolving lines. Oper- -

culum with nucleus at upper inner angle.
Stones River of Wisconsin, Illinois, and Tennessee.
191. M. logani Salter. (Fig. 920.) Ordovicic.
Up to 3% inches in diameter, of few rapidly enlarging whorls,
the width of the outer whorl being about three times that of the

GASTROPODA—EUOMPHALIDE.. 665

Fic. 918, A. Maclurea magna, a, 6, c, upper, lower and side view of a character-
istic shell, X %4 ; d-f, 3 views of large operculum, & %. (After Raymond. )

whorl next adjoining ; upper surface almost flat, outer surface of
whorls with deep revolving grooves. Operculum with nucleus
near rim.

Black River (?) of Ottawa River region in Canada, also European.

Fic. 919. Maclurea bigsbyi, < 7%. Upper, profile and umbilical views. (After
Ulrich, Pal. Minn.)

666 NORTH AMERICAN INDEX FOSSILS.

192. M. (Maclurina*) manitobaensis Whiteaves. (Fig. 921.) —
Ordovicic.
Maximum diameter 8% inches, proportionately low, whorls

Fic. 920. Maclurea logani, x 24. Young with operculum in place ; operculum of
adult ; umbilical view of first specimen. (After Salter, Cau. Org. Rem., I.)

slowly increasing in diameter; umbilicus moderate ; upper side
with periodic growth constrictions.

Fic. 921. Maclurea ( Maclurina) manitobaensts, x 24. (After Ulrich, Pal. Minn. )

Trenton of Minnesota and numerous localities in Manitoba and
elsewhere.

193. M. (Maclurina) cuneata Whitf. (Fig. 922.) Ordovicic.

Fic. 922. Maclurea (Maclurina) cuneata, X 7%. (After Ulrich, Pal. Minn.)

* Maclurina is separated from MJaclurea by Ulrich and Scofield on account of the
absence of the muscular projections on the inside of the operculum characteristic of the
true MWaclurea (see Fig. 920).

GASTROPODA—TROCHOTURBINIDE. 667

Medium-sized, with small umbilicus and regularly sloping under
sides.

Trenton (Galena) of Minnesota, Wisconsin, and Iowa. Similar
though larger specimens occur in the limestones of Lower Trenton
age in the Big Horn and Black Hill regions.

Family TROCHOTURBINIDZ Koken.

LXI. OmpHacotrocuus Meek.

Large and ponderous euomphalids, with high spire, whorls
touching slightly, aperture oblique, with upper lip projecting.
Shoulder, and sometimes also the periphery, flattened or concave.
Mississippic—Carbonic.

194. 0. springvalensis White. (Fig. 923.) Mississippic. |

Fic. 923. Omphalotrochus springvalensis. (After Keyes. )

Whorls rounded, except for a slight flattening of the shoulder ;
gradually enlarging ; height 55 mm., basal diameter 70 mm.
Kinderhook and Burlington of Iowa and Missouri.

LXIJI. Porteumita Clarke and Ruedemann.
Small, and with the round whorls merely touching, and strongly
marked by spirals. Siluric.

195. P. scamnata Cl. and R. (Fig. 924, 2.) Siluric.
With numerous sharp spirals ; faint transverse markings.
Guelph of New York and Canada. Monroe of Michigan ?

196. P. crenulata (Whiteaves). (Fig. 924, a.) Siluric.

’

668 NORTH AMERICAN. INDEX. FOSSILS.

Few and coarser spirals ; strong transverse sculpture.

Guelph of New York and Canada.

Fic. 924. «a, Polenmita crenulata,; 6, P. scamnata (right). (After Clarke and
Ruedemann, Guelph Fauna.)

~LXIII. Cycronema Hall.

Shell of ventricose whorls, turbinate or conical, with numerous
spirals, an oblique aperture, and a thickened, reflected, and flat-
tened or excavated columellar lip and no umbilicus. Ordovicic—
Devonic.

197. C. bilix Conrad. (Fig. 925, a, 0.) Ordovicic.

FIG. 925. a, 6, Cyclonema bilix; c,d, C. mediale; e-g, C. humerosum ; h,t, C. vart-
cosum,; 7, C. sublave. (After Ulrich & Scofield, Pal. Minn. )

GASTROPODA—TROCHOTURBINIDEA.. 669

Whorls embracing to ambitus; suture slightly excavated ;
shoulder nearly flat ; spirals comparatively simple, an intercalated
series occurring on the body whorl; sharp oblique lines of growth,
often strongly marked and crowded.

Richmond group of Indiana, Ohio, Illinois, and Minnesota.

198. C. mediale Ulrich. (Fig. 925, c, @.) Ordovicic.

Whorls more ventricose than preceding, spirals coarser, suture
shallow.

Lower and Upper (C. kumorosum) Lorraine of Ohio, Kentucky,
and Indiana. In those of the upper beds, the whorls embrace
more strongly, the form becoming more compact and wider angled
(C. humorosum Ulrich, Fig. 925, e-g).

I9gg. C. varicosum Hall. (Fig. 925, %, 2.) Ordovicic.

Round-whorled, primary spirals coarse, with several finer
between.

Trenton of Kentucky, Tennessee, Michigan, etc.

200. C. subleve Ulrich. (Fig. 925, 7.) Ordovicic.

Similar to C. mediale but with spirals more or less obsolete
especially on the shoulder.

Lower Lorraine of the Cincinnati dome region.

LXIV. TrocHonema Salter.

Turbinate shells with angulated whorls and a wide peripheral
band bounded by more or less sharply-defined carinze. Addi-
tional carinze at suture and umbilicus often present. Aperture
oblique and umbilicus wide. Ordovicic—Siluric.

Fic. 926. a, 6, Trochonema umbilicatum ; c, d, T. umbilicatum var. (After Ulrich
and Scofield, Pal. Minn. )

201. T. umbilicatum Hall. (Fig. 926.) Ordovicic.
Shoulder flat or slightly concave; peripheral band vertical,
rarely concave; umbilicus bounded by well-marked angulation,

670 NORTH AMERICAN INDEX FOSSILS.

between which and the peripheral band is a nearly flat, sloping
surface. Last whorl often partially loosened.

Trenton of Canada, New York, Kentucky, Tennessee, Wiscon-
sin, and Illinois. Several varieties are recognized.

Fic. 927. TZrochonema belottense. ( After Ulrich, Pal. Minn. }

202. T. beloitense Whitf. (Fig. 927.) Ordovicic.
More rapidly expanding, higher volutions, thicker test, coarser
surface markings, more prominent angles, and smaller umbilicus.

Fic. 928. a,b, Trochonema vagrans; c,d, T. (Eunema) nitidum ; e, f, T. ( Gyro-
nema) pulchellum, g,h, T. (Gyronema) duplicatum. (After Ulrich, Pal. Minn.)

Stones River of Minnesota, Wisconsin, and Illinois.
203. T. vagrans U. and S. (Fig. 928, a, 4.) Ordovicic.
Similar to 7. delottense, but whorls somewhat more slender, and
the last more than half free.
Stones River group, Minnesota.

204. T. (Eunema) nitidum Ulrich. (Fig. 928,c,d@.) | Ordovicic.

GASTROPODA—TROCHOTURBINIDZ.. 671

Small, high-spired, shoulder concave, lower peripheral carina
obsolete. In Z. sa/tert U. and S. the spire is still higher (less
embracing), and the lower peripheral carina almost as strong as
the upper.

Trenton of Minnesota (7: sa/tert); Utica of Cincinnati region (7.
nitidum).

205. T. (Gyronema) pulchellum Ulrich and Scofield. (Fig.
a23, ¢, /.) Ordovicic.
Small, rather high-spired, with apical angle about 85°. In the

body whorl occurs a spiral on the shoulder near the suture,

between the two peripheral ones, and five or six on the basal por-
tion of the whorl. Intercarinal space convex.

Black River of Minnesota and Kentucky.

206. T. (Gyronema) duplicatum U. and S. (Fig. 928, g, 4.)

Ordovicic.

Larger than preceding, with closed umbilicus, carina fainter,
shoulder carina often obsolete, central peripheral one sometimes
double or with an additional one ; lower 6 or 7 faint.

Black River of Wisconsin, Minnesota, and Illinois.

LXV. ANompHALUS Meek and Worthen.

Shell naticoid, small, but without umbilicus ; low spire and in-
complete aperture. Carbonic.

207. A. rotulus M. and W. (Fig. 929.) Carbonic.

Fic. 929. Anomphalus rotulus, side Fic. 930. Anomphalus ( Protospirialis)
and under views, & 21%. (After Meek minulissima, X 5. (After Clarke. )
and Worthen, IIl., V.)

Small, depressed, with scarcely visible spire ; volutions increas-
ing rather rapidly ; aperture transversely suboval ; surface smooth.

Coal measures of Illinois, lowa, and Missouri.
208. A. (Protospirialis) minutissima Clarke. (Fig. 930.)
| Devonic.

672 NORTH AMERICAN INDEX FOSSILS.

Minute (1.5 mm. in height and width) with three or four rapidly
expanding whorls, last one ventricose ; aperture subcircular, outer
lip thin, inner lip slightly reflexed, scarcely covering umbilicus.

Abundant in Portage (Naples) beds throughout western New
York, etc. Pelagic. (Clarke refers them to the pteropods. They
may be pelagic protoconch stage of other gastropods. )

LXVI. PycnompHatus Lindstrom.

Round-whorled, strongly embracing shells, with the umbilicus
covered by an inner flange-like expansion of the shell, which thus
appears non-umbilicate. In the internal mold a large umbilicus is
seen. Siluric.

209. P. solarioides (Hall). (Fig. 931.) Siluric.

d

Fic. 931. Pycnomphalus solarioides. a, apical view of internal mold; 4, lateral
views of same; c, vertical section, showing prominent inner spiral lamella; ¢, umbil-
ical views of shell. (After Whiteaves, Pal. Fossils, III.)

Large, rather low-spired whorls strongly embracing, viewed from
above, very gradually enlarging, and numerous. Base broad,
flat, without umbilicus in shell.

Guelph of Canada, New York, Ohio (?).

7

GASTROPODA—NATICOPSIDE. 673

Family Naticopsip# * Gr. & Sh.
LXVII. Cyctora Hall.

Minute spiral shells of rounded whorls, loosely embracing so as
to leave deep suture and umbilicus; surface smooth, lip thin,
aperture circular. Ordovicic—Devonic.

210. C. minuta Hall. (Fig. 932.) Ordovicic.

er

Fic. 932. Cyclora minuta, x 6. (After Meek, Pal. Ohio, I.)

Subglobose, wider than high, with much depressed spire, three
rapidly increasing volutions ; suture almost channeled ; umbilicus
small. (Possibly pelagic protoconchs of other gastropods.)

Cincinnati group of Ohio and Kentucky, etc. Abundant.

LXVIII. Narticorsis McCoy.

Oval to globose non-umbilicated shells, with small spire, large
body whorl, oval aperture, and with inner lip more or less cal-
lous, flattened, and sometimes transversely striated. Operculum
non-spiral. Devonic—Triassic.

211. N. ziczac Whitf. (Fig. 933.) Mississippic.

FIG. 933. <A avicopszs ztczac, natural size FIG. 934. Vaticops7s ventricosus,
and enlarged. (After Whitfield, N. Y. opposite views. (After Meek and Worth-
Acad. Science Proc. ) en, “Ill, ‘Geol... ¥s)

Small, whorls regularly though rapidly increasing in size, sur-
face of body whorl with marked zigzag strie.
Chester (Maxville) of Ohio.

674 NORTE MER ICAN: INDEXCROSSILS.

212. N. ventricosa Norwood and Pratten. (Fig. 934.) 3
Mississippic—Carbonic, __
Whorls rapidly enlarging, last one ventricose-elongate, and |
strongly concave below the suture.
Archimedes limestone of Illinois; Coal measures of Indiana
and Missouri.

213. N. altonensis McChesney. (Fig. 935.) Carbonic.
Larger than the preceding, spire more sunken, body whorl more
rounded, concavity proportionately less broad and at greater angle
with axis of shell. Var. giganteus M. and W. is larger and con-
cave shoulder broader.
Coal measures of Illinois and New Mexico.

214. N. torta (Meek). (Fig. 936.) Carbonic.

a

Fic. 935. Vaticopsis alto- Fic. 936. Vaticopsis torta. (After
nensis. (After Meek and Meek, Ohio Pal., II.) .
Worthen, Ill. Geol., V.)

Early whorls close-coiled, adult whorls loose ; aperture circular,
a slight rounded ridge on the outer part of the last whorl, and a
faint flattening above is observable.

Coal measures of Ohio.

LXIX. Tracuypomia M. and W.
Like Maticopsis, but with nodose surface. Devonic ?—Carbonic.
215. T.(?) precursor (Clarke). (Fig. 937.) Devonic.
Early whorls round, adult flattened and angulate below; adult
ornamentation of numerous regular spiral rows of nodes.

Portage (Naples) and Chemung of New York, Maryland, etc.

216. T. wheeleri (Swallow). (Fig. 938.) Carbonic.
Rapidly-enlarging whorls, body whorl gibbous, aperture sub-

GASTROPODA—NATICOPSIDZ. 675

ovate ; surface with numerous revolving rows of small tubercles
increasing in size with the whorls.

Fic. 937. Trachydomia pre ursor. (After Clarke. )

Coal measures of Indiana, Illinois, Iowa, Missouri, and New
Mexico.

217. T. nodosum M. and W. (Fig. 939.) Carbonic.

Fic. 938. TZrachydomia wheeleri. ( After FIG. 939. Trachydomia nodosum.
White, 13th Ind. ) (After Meek and Worthen, II]. Pal., II.)

Larger, more rapidly enlarging, nodes irregularly scattered or
arranged in vertical instead of horizontal rows.
Coal measures of Ohio, Illinois, and Missouri.

LXxX. Tursonopsis* Grabau and Shimer.

— Young shell as in Matecopsis; adult whorls expanding; with
wrinkles or ribs, and a median carina. Devonic.

a

Fic. 940. TZurbonopsis shumardi, young and adult, «K %. (After Hall, Pal. N
May Mie)

a

676 NORTH AMERICAN INDEX FOSSILS.

218. T. shumardi (de Verneuil). (Zurbo shumardi.) (Fig. 940.)

Devonice.

Large, last two whorls with strong oblique folds on shoulder

portion, these appear gradually and progressively increase in

strength; median carina strong, blunt ; aperture subpentahedral.

Onondaga of Ohio, Falls of Ohio, Indiana, Kentucky, and New
York (?).

Family STROPHOSTYLID& * Grabau & Shimer.
LXXI. Hotopea Hall.
Spirally coiled shells with round whorls generally smooth, and
complete aperture. Ordovicic—Mississippic ?
220. H.-amplasU and 5... (Pig. g41-) | Ordovicic.

Fic. 941. Holopea ampla, X 7%. (After Ulrich, Pal. Minn.)

Large, umbilicated, growth lines frequently fasciculate and coarse.
Stones River of Minnesota and Wisconsin.

220. H. similis U. and S. (Fig. 942, a (left).) Ordovicic.,
Smaller, higher spired, more slender and with smooth whorls.
Black River of Minnesota, Lorraine of Kentucky.

221. H. rotunda U. and S. (Fig. 942, 4 (right).) Ordovicic.
Small, whorls higher, spire less obtuse, umbilicus smaller than

in preceding.

Stones River of Illinois; Trenton of Tennessee.

Fic. 942.. Holopea similis (left); .
rotunda (right). (After Ulrich and ( After Ulrich and Scofield, Pal.
Scofield, Pal. Minn. ) Minn. )

GASTROPODA—STROPHOSTYLIDZ. 677

222. H. textilis (Ulrich and Scofield). (Strophostylus textilis U.
pe )S,).4 (Fig. 943.) Ordovicic.
High-spired (apical angle 60°—70°), six or seven whorls; re-

volving lines cancellated by oblique lines.

Black River and Trenton of Minnesota; Trenton of Kentucky.

223. H. antiqua (Vanuxem). (Fig. 944.) Siluric.

Fic. 944. Holofea antigua, internal Fic. 945. Holopea pervetusta, com-
molds. (Pal. N. Y., III.) plete shell and internal mold. (Pal.
PN kl.)

High-spired, suture depressed, smooth except for lines of growth.
Manlius of New York, New Jersey, etc. Upper Monroe of
Michigan.
224. H. pervetusta Hall. (Fig. 945.) Siluric.

More slender and higher spired than
preceding. Occurs with preceding.

225. H.(?) proutana Hall. (Fig. 946.)
Mississippic.
Very high-spired for the genus, apical
angle acute, aperture round-ovate, no um-
Dilicus. Fic. 946. olopea (?)

: oe" proutana. (After Whitfield,
St. Louis (Spergen) of Illinois and In-‘y.. Mus. Nat. Hist. Bull.)
diana.

LXXIJ. Stropyostytus [all.

Round-whorled shells, generally
with low spire and very ventricose
body whorl; peristome round; colu-
mellar lip twisted and grooved; sur-
face often finely cancellated, though
frequently only lines of growth ap-
pear. Ordovicic—Carbonic.

UE .
ES. Sirophosty/us cyclosto- 226. S. cyclostomus Hall. (Fig.
mus. (After Hall.) 947.) Siluric.

678 NORTH AMERICAN INDEX FOSSILS.

Of medium size, whorls gradually enlarging ; body whorl en-
larging rather rapidly ; strong vertical and rather fainter revolving
Strix.

Niagaran of Indiana ; Monroan of Michigan.

227. S. expansus Hall. (Fig. 948.) Devonic.

Fic. 948. Strophostylus expansus. (After Hall. )

Large, with a few small apical whorls and a very large and
rapidly-expanding body whorl.

Oriskany of New York.
228. S. carleyanus (Hall). (Fig. 949.) Mississippic..

Small, subglobose, final whorl expanded most vertically ; aper--
ture ovate; sutures deep.

St. Louis (Spergen) of Illinois and Indiana.
229. S. nanus (M. and W.). (Fig. 950, a, 4.) Carbonic.

Small ; differs from preceding in greater horizontal and less ver-
tical diameter, and in shallow sutures.

Coal measures of Illinois, Indiana, Ohio, Iowa, Missouri,
Arkansas, and Nevada.

230. S. remex (White). (Fig. 950, c.) Carbonic.

GASTROPODA—STROPHOSTYLIDZ. 679

Medium-sized, of four volutions, very oblique through loose
coiling, last one partly free; expanding rapidly, but more uni-
formly than in most species.

Carbonic limestones of Missouri, Texas, and Utah.

Fic. 949. Strophostylus carley- Fic. 950. Strophostylus nanus, a, 6, 2 views;
anus, (After Whitfield, Am. Mus. c (right), S. remex. (Ind. Surv. & Bull. 77,
Nat. Hist. Bull.) GeS. G5.)

LXXIII. DiarHorostoma Fisher. (Platyostoma Conrad.)

Differs from Strophostylus in the regular enlargements of the
whorls, the last not being ventricose ; columellar lip smooth.
Siluric—Devonic.

231. D. niagarense Hall. (Fig. 951.) = \o stare.

Fic. 951. Diaphorostoma niagarense. (After Hall. )

Body-whorl inflated toward aperture ; sutures deeply depressed ;
3-4 volutions ; fine spiral and strong transverse striz.

Niagaran and Guelph of New York and nearly all other
exposures.
232. D. ventricosum Conrad. (Fig. 952.) Devonic.

Larger and more ventricose than preceding ; aperture nearly
circular.

Helderbergian and Oriskanian of New York, etc.

680 NORTH. AMERICAN INDEX. FOSSILS.

Fic. 952. Diaphorostoma ventricosum, (After Hall.)

233. D. lineatum (Conrad). (Fig. 953.) Devonic.
Regularly enlarging whorls, forming moderate spire; scarcely
depressed sutures ; fine regular spirals and transverse striz.
Onondaga and Hamilton of New York, Indiana, and elsewhere
in eastern North America.

Fic. 953. Diaphorostoma lineatum. (After Hall.)

LX XIV» -PLATYCERAS Conrad:

Young shell coiled asin Diaphorostoma, late stages non-coiling,
. often spinous. (In this polyphyletic genus are
commonly included non-coiling shells of di-
verse origin; the typical species are derived
from Diaphorostoma.) Siluric—Carbonic.
234. P. niagarense (Hall). (Fig. 954.)
Siluric.

Apex only enrolled in one volution; re-
mainder rather rapidly expanding, last portion
longitudinally undulated.

Niagara of New York and elsewhere.

Mis. 934. f¥atyceras 945. PB, gebhardi Hall. (Fig: 955, oem

niagarense. (After D :
Hall.) evonic,

S LAke Diaphorostoma ventricosa, but loose-
coiling, last whorl partly free.

GASTROPODA—STROPHOSTYLIDZ. 681

Helderbergian of New York, etc.; Oriskany of Maryland, etc.
236. P. ventricosum Conrad. (Fig. 957.) Devonic.

Fic. 955. Platyceras gebhardt. Fic. 956. Platyceras gebhardi, side
(After Hall.) view. (After Hall.)

Probably derived from a Strophostylus. Last whorl partly free,
and extremely ventricose.
Helderbergian of New York, etc. Oriskany of Maryland.

237. P. tenuiliratum Hall. Devonic.

Fic. 957. Platyceras ventricosum. (After Hall.)

Like a small P. wentricosum, with reflexed inner lip, sinuous
margin, and surface cancellation by fine revolving and transverse

Sstrie. |
Helderbergian of New York.

Fic. 958. Platyceras multisinuatum. (After Hall.)

682 NORTH AMERICAN. INDEX. FOSSILS.

238. P. multisinuatum Hall. (Fig. 958.) Devonic. ~
Like a small P. gebhardi, with longitudinal folds and strongly
sinuous margin.

Helderbergian of New York.
239. P. unguiforme Hall. (Fig. 959, a—c.) Devonic.

Fic. 959. a-c, Platyceras unguiforme var. multicarinatum ; b, P. unguiforme ;
d-f, P. dilatatum, showing varieties (¢, /, opposite views of same specimen). (Pal.
Ni Ves TBE

Like preceding, but mostly non-coiling.
Helderbergian of New York.

240. P. dilatatum Hall. (Fig. 959, a)
Devonic.
Like P. tenuchratum, but only apex coiled;

sometimes carinate.
Helderbergian of New York.

241. P. spirale Hall. (Fig. 960.) Devonic.

Non-coiling except at apex, but with a
few irregular twists ; somewhat plicate.

Helderbergian of New York. (A more
slender, less plicate form occurs in the
Oriskany (P. fortuosum), and a similar one
making only half a twist (P. dentalium) in
the Onondaga of New York.)

Bi aes. Pada an 242. P. magnificum Hall. (Fig. 961.)
(After Hall. ) Devonic.

vale,

GASTROPODA—STROPHOSTYLIDA. 68 3

Like P. ventricosum with apex only coiled.
Oriskany of Maryland, etc.

Fic. 961. Platyceras magnaficum, a small individual. (Pal. N. Y., III.)

243. P. reflexum Hall. (Fig. 962.) Devonic.
Like P. gebhardi, but only coiled apically.
Oriskany of Maryland, etc.

244. P. arkonense Shimer and Grabau. Devonic.

Fic. 962. Platyceras reflexum, opposite views of two individuals. (Pal. N. Y., III.)

Similar to the next, but with scattered slender spines.

Hamilton of Ontario, Michigan, and Iowa, Charlestown, Indiana.
245. P. erectum Hall. (Fig. 963, a.) Devonic.

Like Diaphorostoma lineata, with last whorl free, and margin
oblique and sinuous.

Hamilton of New York, Ontario, etc.

246. P. carinatum Hall. (Fig. 963, 2.) Devonic.

684 NORTH AMERICAN INDEX FOSSILS.

Like P. mudltisinuatum, but with compressed or carinated periph-
ery and very oblique aperture.

Hamilton of New York, Ontario, etc.; Sellersburg of Indiana.
247. P. symmetricum Hall. (Fig. 964.) Devonic.

Like P. evectum, but only apically coiled ; margin sinuous.

Hamilton of New York, etc.

248. P. thetis. (Fig. 963, d.) Devonic.

Fic. 963. a, Platyceras erectum,; 6, P. carinatum; d, P. thetis,; e, P. bucculentum.
(Copied from Hall.)

More slender than preceding and strongly plicate.
Hamilton of New York, Ontario, etc.; Sellersburg of Indiana.
249. P. bucculentum. (Fig. 963, ¢.)
Devonic.
Rapidly enlarging, lip strongly sinuate,
especially on one side.
Hamilton of New York, Ontario, etc. ;
Sellersburg of Indiana.

250. P. nodosum Conrad. (Fig. 965.)

Fic. 964. Platycer - .

9 4 aLyces as Symme Devonic.
tricum. (Copied from Hall.)

Like P. gebhardi when young, but

with last volution bearing numerous strong rounded nodes. Adult
molds generally without coiled young, and strongly nodose.
Helderbergian and Oriskanian of New York, etc.
251. P. dumosum Conrad. (Fig. 966.) Devonic.
Coiled only apically, rapidly expanding, numerous nodes (in
molds) and hollow spines corresponding to them.
Onondaga of New York and Ontario ; Columbus of Ohio and
Michigan ; Jeffersonville of Falls of the Ohio. |

252. P. vomerium Winchell. Mississippic.

GASTROPODA—STROPHOSTYLID-. 685

General form as in P. ducculentum, but apex merely incurved
instead of enrolled.
Kinderhook of Iowa; Waverly of Ohio.

253. P. tribulosum White. (Fig. 967.) Mississippic.

Fic. 965. Platyceras nodosum, mold of a large scarcely coiled form. (After Hall.)

Similar to preceding, with strong sinuosities in lip, and three
rows of hollow spines. |
Burlington of Iowa and Missouri.

254. P. haliotoides Meek and Worthen. (Fig. 968.)
Mississippic.

Fic, 966. Platyceras dumosum, K 24. (After Hall.)

686 NORTH AMERICAN INDEX FOSSILS.

Haliotis- \ike ; resembling vertically compressed small P. ventri-
cosum with very oblique aperture. :

Waverly of Ohio ; Choteau of Missouri.
255. P. paralius White and Whitf. (Fig. 969.) Mississippic.

Small, apex slightly enrolled, lower portion strongly plicate.

ces

Fic. 967. Platycerastribu- Fic. 968. Platyceras halio- Fic. 969. Platyceras
losum, (After Keyes. ) toides. (After Keyes. ) paralius, type. (After
Keyes. )

Kinderhook of Iowa and Missouri; Waverly of Ohio ; Burling-
ton of Missouri.

256. P. parvum (Swallow). (Fig. 970.) Carbonic.

Fic. 970. Platyceras parvum, opposite views of a specimen attached toa crinoid stem.
(After White, 13th Ind. )

Entire shell making about one loose volution ; aperture very
sinuous.

Coal measures of Kansas, Nebraska, Illinois, New Mexico,
Indiana, Iowa, Missouri.

LXXV. PALAocAPULUS * Grabau and Shimer.

Symmetrical platyceroids with the beak incurved but scarcely
enrolled in the median line or slightly deflected. (Possibly derived
from Cyrtolites.) Type P. lodiensis. Devonic—Mississippic.

257. P. expansus Hall. (Fig. 971.) Devonic.

FIG. 971. Paleocapulus expansus. {Pal. Ne Y., TIEg

GASTROPODA—STROPHOSTYLIDEZ. 687

Apex strongly incurved, shell rapidly expanding, ventricose
and dorsally carinate ; aperture nearly circular.

Oriskany of New York and Pennsylvania ; Decewville of Ohio.
258. P. equilateralis (Hall). | Mississippic.

Symmetrically expanding from incurved but not enrolled apex.
Generally attached to crinoids.

Keokuk of Iowa, Illinois, Maryland, Missouri; Burlington of
Iowa and Missouri.

259. P. lodiensis (Meek). (Fig. 972.) Mississippic.

pe
et aS
eins

Fic. 972. Paleocapulus lodiensis. (After Meek, Pal. Ohio, II.)

Symmetrical, with slightly overhanging but scarcely incurved
beak and strong dorsal fold from beak to base. (Type of genus.)
Waverly of Ohio.

LXXVI. Ortuonycuia Hall.

Platyceroid shells with apex incurved but not enrolled, and
generally long, slender, though not symmetrical &
body portion. A polyphyletic group. Devonic—
Carbonic.

260. O. subrectum Hall. (Fig. 973.)
Devonic.
Minute (and solid) apex, abruptly incurved ;
shell long and slender, nearly straight ; no plica-
tions.
Onondaga of New York, etc.

FIG. 973. Orthony-
chia subrectum.

261. O. formosum Keyes. (Fig. 974.) (After Hall, Pal. N.
Mississippic. ees
Elongate ; strongly and regularly curved, lower portion plicate.
Transitional to Igoceras.
Kinderhook of Iowa; Burlington of Missouri. Attached to
crinoids.

688 NORTH; AMERICAN INDEX, FOSSILS.

262. O. cyrtolites McChesney. (Fig. 975.) Mississippic.
Slender, smooth, with apex curved over strongly; dorsally sub-
angular.

Burlington of Illinois, Iowa, and Missouri.
263. O. chesterensis M. and W. Mississippic.

Fic. 974. Orthonychia formosum, at- Fic. 975. Orthonychia cyrtolites.
tached to crinoid. (After Keyes.) (After Keyes.)

Small, strongly curved, with about five grooves and very sin-
uous aperture.

Chester of Illinois, Missouri, and Kentucky.
264. O. acutirostris Hall. (Fig. 976, 977.)

Mississippic—Carbonic.
Apex making about a single volution, not in contact; shell

Fic. 976. Orthonychia acutirostris on Pterotocrinus acutus. (After Keyes. )

widening abruptly below apex, often with shallow plications ;
aperture subcircular with sinuate margin.

Keokuk and Warsaw of Illinois, Indiana, and Alabama; St.

Fic. 977. Orthonychia acutirostris. (After Whitfield, Mus. Comp. Zodl. Bull. )

GASTROPODA—STROPHOSTYLIDE. 689

Louis of Indiana, Illinois ; Chester of Arkansas ; Coal measures
of Pennsylvania.
LXXVII. IGoceras Hall.

More or less broadly conical platyceroids with apex not in-
curved ; body portion plicate. (Probably a polyphyletic group.)
Devonic—Carbonic.

265. I. plicatum (Conrad). (Fig. 978.) Devonic.

Apex sublateral, one side more strongly curved; height about

Fic. 978. Jyoceras plicatum. (After Fic. 979. /goceras conicum. (After
Hall. ) Hall, PalicN. ¥.,. V.)

one and one half times greatest diameter; plications few and
shallow, generally only on straight side.
Helderbergian of New York, etc.
266. I. conicum (Hall). (Fig. 979.) ai) Devonic,
Irregularly conical, with apex pointed and subcentral or excen-
tric; height equal to or less than basal diameter ; plications strong,
rounded, sometimes obsolete.
Onondaga and Hamilton of New York, Ontario, and Falls of
Ohio.
267. I. capulus (Hall). (Fig. 980.) Mississippic.
Subregularly conical, with nearly central apex ; a slight flatten-
ing and very faint undulations occur on one side; height less than
basal diameter ; aperture nearly circular.
Burlington of Iowa, Missouri, and Illinois.

690 NORTH AMERICAN INDEX FOSSILS. |

Fic. 980. Jgoceras capulus. (After Keyes. )

268. I. quincyense (McChesney). (Fig. 981.) Mississippic.

Height nearly equal to basal diameter ; lower half deeply and
coarsely plicate ; apex subcentral.

Fic. 981. Jlyoceras quincyense, at- Fic. 982. Jgoceras fissurella, (After
tached to calyx of crinoid. (After Keyes. )
Keyes, )

Burlington of Illinois, Iowa, and
Missouri. |

269. I. fissurella Hall. (Fig. 982.)
Mississippic.
Higher, somewhat more strongly

plicate, and with more excentric apex
than /. capulus.
uate.

Aperture more sin-

Burlington of Iowa; Keokuk of
I]linois.

270. I. pabulocrinus
Owen. (Fig. 983.)
Mississippic.
Like 7 fissurella, but Fis. 984.
Fic. 983. Jgoceras pabulocrinus

é Igoceras sub-
on Platycrinus hemisphericus. (Aft- more slender and with at-

plicatum..
er Keyes. ) tenuated, often bent apex ; (AfterKeyes. )

GASTROPODA—LOXONEMATIDZ. 691

folds indistinct ; lines of growth often undulating and imbricating
in adult portion. Commonly adhering to crinoids.

Burlington of Iowa and Missouri; Keokuk of Iowa, Illinois,
and Indiana.

271. I. subplicatum Meek and Worthen. (Fig. 984.)
Mississippic.
Small, depressed conical, rapidly expanding, beak excentric ;
folds coarse, irregular, few.
Waverly of Ohio; Chester of Illinois.

Family LoxoNEMATID# Koken.
LXXVIII. AcANTHONEMA Grabau.

Turreted shelis, with gradually enlarging round whorls marked
‘by three (rarely two) spirals, one or more of which are nodose.
Type A. holopiforme Grabau. — Siluric.

272. A. holopiforme Grabau. Siluric.
Short, rather thick, round whorled, lower
spiral covered except on body whorl; upper
two nodose. (Middle one absent in var.
-obsoleta.)
Upper Monroe of Michigan, Ohio, and
‘Canada.
273. A. laxum Grabau. Siluric.
Long and slender, whorls six or more,
all three spirals visible, upper two nodoso-
spinose.

FIG, 985. Acanthonema

Upper Monroe of Michigan, Ohio, etc. —xewserryi, nat. size and
f . A. i (Meek). io. enlarged. (After Meek,
274. A. newberryi (Meek). (Fig = Ds Sc) aa

More slender than preceding ; nodulations chiefly confined to
upper spiral
Upper Monroe of Ohio and Michigan.

LX XIX. CALtonema Hall.

Broad and rather low-spired,. umbilicated shells with round or
‘ssubangular whorls, thin outer lip, and thickened columellar lip
spread over volution above and extended below. Surface with
regular, sharp, transverse striz. Devonic.

692 NORTH AMERICAN INDEX FOSSILS.

275. C. bellatulum Hall. (Fig. 986.) Devonic.
Whorls (six or seven) round to flattened on the shoulder and
subangular below. In form and size like Cyclonema bilx, but
readily distinguished by its transverse striz.
Onondaga of northern Ohio, Michigan, and Falls of the Ohio.

276. C. lichas Hall. Devonic.

i

Fic, 986. Callonema bellatulum. (After Fic. 987. Callonema humile.
Hall, Pale NOY. V2) (After Meek, Pal. Ohio, I.)

Larger, with larger apical angle and last volution more ventricose.
Onondaga of New York and Ohio and Falls of the Ohio. |
277. C. humile Meek. (Fig. 987.) Devonic.

Spire broad and low; whorls strongly embracing, rounded, and
rapidly enlarging; stria finer and more crowded on adult por-
tion than in preceding.

Onondaga of Ohio and Falls of the Ohio.

LXXX. IsoneEmA Meek and Worthen.

Differs from Callonema in its compressed whorls and angular
periphery, and in the obsolescence of the striz below the angula-
tion. Devonic.

278. I. depressum M. and W. Devonic.
Small, depressed, whorls embracing above periphery.
Hamilton of Illinois. s

LXXXI. Loxonema Phillips
Turreted shells, the high spire of many whorls, non-umbilicated ;
transverse striae forming a double curve. Siluric ?—Carbonic.
279. L. robustum Hall. Devonic.
Robust, last volution ventricose, nearly an inch in diameter,
length about 4 inches,

GASTROPODA—LOXONEMATIDZ. 693

Schoharie and Onondaga of New York.
280. L. pexatum Hall. (Fig. 988.) Devonic.
More slender than preceding, with deeper sutures, volutions
slightly flattened below suture; striz gently curved.
Onondaga of New York and northern Ohio.

281. L. hamiltonie Hall. (Fig. 989.) Devonic.

Fic. 988. Loxonema pexata. (After Fic. 989. Loxonema hamiltonie.
Fiaityral. N. Y., V.) (After Hall, Pal. N.Y, ¥.)

Very slender, volutions flattened or slightly concave below,
deep sutures, embracing to about one half shoulder width of
periphery. Striz strongly marked.

Hamilton of New York, etc.

282. L. delphicola Hall. (Fig. 990.) Devonic.

Fic. 990. Loxonema delphicola, (After Hall, Pal. N. Y., V.)

With distinct subsutural band.
Hamilton of New York, etc. ; Bedford shale of Ohio.
283. L. noe Clarke. (Fig. 991.) Devonic.
Very slender, round-whorled ; concavity of strize in upper third
of whorl.
Portage (Naples) of New York.

694 NORTH: AMERICAN INDEX FOSSILS.

284. L. terebra Hall. (Fig. 992.) Devonic.
Whorls embracing to just below periphery ; shoulder flat or
concave ; spire slender ; striz strong.
Chemung of New York.

285. L. yandellana Hall. (Fig. 993.) Mississippic.

FIG. 991. Loxonema noe, XK 3, and Fic. 992. Loxonema terebra. (After
apical portion enlarged, & 13. (After Fiall,’ Pal, N.Y. Vn)
Clarke. )

Small, with gently convex whorls and deep sutures ; striz very
gently undulating, not curved.

St. Louis (Spergen) of Indiana ; Waverly of Ohio (?).
286. L. multicostatum M. and W. (Fig. 994.) Carbonic.

Fic. 993. Loxonema Fic. 994. Loxonema Fic, 995. Loxonema

yandellana, ( After multicostatum, <2. (After rugosum, X 2. ( After
Whitfield, Amer. Mus. Meek and Worthen, Pal. Meek and Worthen, Pal.
Nat. Hist. ) 1 1a ABN, Tl, dae)

Small, round-whorled, rather broad-spired, with numerous gently
and simply curved striz, about 30 on the body whorl.
Coal measures of Illinois, Iowa, and Missouri.

GASTROPODA—LOXONEMATID.. 695

287. L. rugosum M. and W. (Fig. 995.) Carbonic.
Like the preceding, but the striz stronger, scarcely curved and
almost rib-like, about 18 to a whorl.
Coal measures of Illinois, New Mexico, etc.

288. L. scitulum M. and W. (Fig. 996.) Carbonic.

A
F

i

Fat

r
¥
oe

Fic. 996. Loxonema scitulum. (After Fic. 997. Loxonema ( Streptaxis)
Meek and Worthen, Pal. IIl., II.) whitheldi, X 4, with protoconch and
body whorl further enlarged.

Smaller than preceding, suture more deeply impressed, coste
about &4 to a whorl, obsolete on base of body whorl.

Coal measures of Illinois, lowa, and Missouri.
289. L. (Streptaxis) whitfieldi Meek. (Fig. 997.) | Carbonic.

Minute, slender, loose-coiled, with 8 or g long slender whorls.
and deep suture, aperture oval; surface striz fine, numerous, and.
doubly curved ; apex erect.

Coal measures of Illinois and Iowa (roof of Danville coal).

LXXXII. Actisina de Koninck.

Like Loxonema, but with spiral lines on the whorls, the vertical
sigmoid lines weak. Carbonic.

290. A. robusta Stevens. (Fig. 998.) Carbonic.

Fic. 998. Aclisina robusta, X 2%, FIG. 999. <Aclisina stevensana, com-

and body whorl much enlarged. (After plete individual, 3; body whorl greatly
Meek and Worthen, III. Geol., V.) enlarged. (After Meek and Worthen,

Ill. Pal., II.)

Minute (5 mm. long), rather broad-spired, round-whorled, with
numerous fine revolving lines and sigmoid lines of growth.

*

696 NORTH AMERICAN INDEX FOSSILS.

Coal measures of Illinois, Iowa, and Missouri.

291. A. stevensana M. and W. (Fig. 999.) Carbonic.
Minute, 6.5 mm. long, rather slender, deep-sutured, with 5 or 6
strong, slender, and distant spirals, the lower generally covered,
except in the body whorl.
Coal measures, Illinois, Missouri, and New Mexico.
292. A. minuta Stevens. Carbonic.
Minute, slender, deep-sutured, of nine or more volutions; aper-
ture subcircular ; surface with numerous fine spirals.
Coal measurers of Illinois, Iowa, and Missouri.

LXXXIII. OrtTHoNEMA M. and W.

Whorls more or less angulate and marked by a few revolving
spirals. Otherwise as in preceding. Carbonic.
293. 0. conicum M. and W. (Fig. 1000.)
Carbonic.
Small ; whorls flattened, angulated below ; sutures
moderately deep; spirals three, very faint, the lower

, below angulation, covered except in body whorl.
SECS, Coal measures of Iowa and Illinois.

Orthonema : Lie ;
conicum. 294. O. subteniatum Geinitz. Carbonic.

(After Meek With three subequally spaced revolving carine,
and Worthen, the lower one covered in all but the body whorl.

i. Vv,
) Coal measures of Iowa, Nebraska, etc.

Family SusuLitip Lindstrom.
LXXXIV. SusuLites Conrad.

Thin, slender, subulate or fusiform shells, with high, flat, or
slightly convex whorls, faintly impressed suture, elongate narrow
aperture, acuminate above and wider or somewhat truncate below,
with lip strongly recurved. Surface smooth. Ordovicic.

295. S. elongatus Conrad. Ordovicic.
Six or more flattened or very gently convex volutions; spire

tapering gently, body more rapidly enlarging.
Trenton of New York, Canada, etc.

296. S. regularis U. and S. (Fig. 1001, a.) Ordovicic.
Large; more slender than preceding ; eight or ten whorls, rapidly

contracting in lower half of body whorl.

GASTROPODA—SUBULITIDE. 697

Stones River and Black River of Minnesota,
Tennessee, Kentucky, and Canada.
297. S. nanus Ulrich. (Fig. 1oo1, 2.)

Ordovicic.

Minute, not over 15 mm. high, very acute apex,
and narrow elongate aperture not quite the length
of the spire.

Stones River of Tennessee and Kentucky.

LXXXV. Fusispira Hall.

Differs from Sudulites in the heavier shell, broader
and shorter aperture, more rounded whorls, and |
deeper sutures. Ordovicic.

298. F. inflata M. and W. (Fig. 1002, 2.)
Ordovicic.

Short, concave-spired, whorls embracing to am-
bitus, body whorl large, inflated.

Trenton of Minnesota, Wisconsin, and Illinois.
299. F. subbrevis U. and S. (Fig. 1002, 0.)

Ordovicic.

Thicker spire, whorls less embracing, body whorl

large and long, but not inflated.

FIG. I0o!.
Trenton of Minnesota and Iowa. Subulites regula-

300. F. subfusiformis Hall. (Fig. 1002, c.) Fo 8 RECS:
F .. (After Ulrich and
Ordovicic. cof, Pal. Minn.)
Slender, whorls gradually enlarging, convex,
body whorl not proportionately larger; apical angle about 25°.

Trenton of Minnesota, Kentucky, New York, and Canada.

301. F. convexa U.andS. (Fig. 1002, @.) Ordovicic.
Like preceding, but apical angle 33° to 37°; whorls more
convex, shorter, and with deeper sutures; aperture relatively
wider ; occasionally with distant revolving spirals.
Trenton of New York and Minnesota.
302. F. angusta U. and S. (Fig. 1002, ¢.) Ordovicic.
More slender, less closely-coiled, and with longer and less
convex volutions than in F. subfusiformes.
Trenton of Minnesota and Kentucky.

698 NORTH AMERICAN INDEX FOSSILS.

SEF d
Fic. 1002. a, Fusispira inflata, 6b, F. subbrevis; c, F. subfusiformis,; d, F. convexa;
e, F. angusta, all x 24. . (After Ulrich, Pal. Minn. )

LXXXVIL MEEKospira Ulrich.

Whorls nearly flat, embracing to ambitus, regularly enlarging ;
aperture short, rounded below, acute above; inner lip visible gen-
erally only in lower half of aperture. Ordovicic ?—Carbonic.

303. M. peracuta M. and W. (Fig. 1003, a, 0.) Carbonic.

Fic. 1003. a, 6, Meekospira peracuta, c,d, M. nitidula, (After White, 13th Ind.
Rep. )
Slender, with acute apex, 12 or more volutions, nearly flat ;
sutures scarcely impressed.
Coal measures of Illinois, Indiana (?), and Missouri.

304. M. nitidula M. and W. (Fig. 1003, ¢, @.) Carbonic.
Less slender, with 8 or more somewhat more convex volutions

last one somewhat longer than half the length of the shell.
Coal measures of Illinois and Indiana.

GASTROPODA—SUBULITID:. 699

305. M. inornata M. and W. Carbonic.
Shorter and somewhat broader than the preceding, sutures less
deeply impressed, body whorl nearly two thirds the length of the
shell.
Coal measures of Illinois, Ohio, Missouri, and Arkansas.

LXXXVII. ButimoreuHa Whitfield.

Like Meekospira, but with more convex volutions, base of aper-
ture acute and notched; outer lip with slight notch at suture.
Mississippic—Carbonic.

306. B. bulimiformis (Hall). (Fig. 1004.) Mississippic.

Fic. 1004. Bulimorpha bulimifor- Fic. 1005. Lulimorpha minuta (a),
mis. (After Whitfield, Am. Mus. Nat. << 4; 4, body whorl greatly enlarged.
Hist. Bull. ) (After Meek and Worthen, IIl., V.)

Small, spire nearly half the length of the shell, volutions con-
vex, suture impressed, surface smooth.
St. Louis (Spergen) of Indiana and Missouri.
307. B. minuta (Stevens). (Fig. 1005.) Carbonic.
Minute, with distinct flat but narrow sutural shelf.
Coal measures of Illinois, Iowa, etc.

LXXXVIII. SorLeniscus M. and W.

Like Aulimorpha, but with base produced into a short, straight
canal, and with a more or less distinct columellar fold. Carbonic.

308. S. typicus M. and W. (Fig. 1006, a, 0.) Carbonic.
Small, slender, acute spire, base much produced, last whorl
nearly three fourths length of shell ; fold strong within.
Coal measures of Illinois and Missouri.
309. S. fusiformis Hall. (Fig. 1006, c, d.) Carbonic.
Whorls regularly enlarging, spire more than half length of
shell; columellar fold broad and low externally ; inner lip with
strong callus.

700 NORTH AMERICAN INDEX FOSSILS.

Coal measures of Iowa, Indiana, Illinois, Ohio, and Arkansas.
310. S. planus White. (Fig. 1006, ¢, /.) Carbonic.

Shorter and more convex than S. fuszformis ; columellar fold
strong.

Coal measures of Ohio, Illinois, and New Mexico.
311. S. newberryi Stevens. (Fig. 1006, g, /.) Carbonic.

Shorter and more convex than preceding; columellar folds
double.

Coal measures of Illinois, Jowa, and Missouri.

312. S. paludineformis Hall. (Fig. 1006, z.) Carbonic.

Fic. 1006. a, 6, Solentscus typicus; c,d, S. fustformis,; e, f, S. planus; g, h, S. new-
berryi,; t, S. paludineformis; 7, k, S. brevis. (All after White, 13th Ind. Rep.)

Short and thick ; spire short but gently concave ; body whorl
large, ventricose ; columellar fold strong.
Coal measures of Iowa, Indiana, Ohio, and Missouri.
313. S. brevis White. (Fig. 1006, 7, 2.) Carbonic.
Small, short and thick, with very convex body whorl. Ap-
proaches Spherodoma.
Coal measures of Iowa, Missouri, Illinois, and New Mexico.
314. S. gracilis Cox. Carbonic.
Like the preceding, but more slender and with much higher
spire.
Coal measures of Iowa, Missouri, and Kentucky.
315. S. regularis Cox. (Fig. 1007.) Carbonic.
Large, with long spire of nine convex volutions. Body whorl

GASTROPODA—SUBULITIDE. 701

comparatively short and contracted. Columellar fold strong.
Coal measures of Ohio and Kentucky.

Fic. 1007. Soleniscus regularis. (After Fic. 1008. Soleniscus klipparti.

Whitfield, N. Y. Acad. Sci. Proc. ) (Pal. Ohio, II.)
316. S. klipparti Meek. (Fig. 1008.) Carbonic.

Last few whorls irregular, elongate, flattened, upper part of
spire normal; columellar fold strong.
Coal measures of Ohio.

LXXXIX. SpH#RODOMA Keyes.

Like Solentscus, but short, thick, and more or less globular ;
body whorl generally very convex. Devonic—Carbonic.
317. S. hamiltonie Hall. Devonic.
Four or five volutions rapidly enlarging, body
whorl ventricose ; base of lip scarcely notched.
Hamilton of New York, Pennsylvania, etc.
318. S. intercalare (M. and W.). (Fig. 1009.)
Carbonic.
Medium-sized, with regularly but rapidly enlarg- |
ing whorls, the last one about two thirds the entire ¢ 4 ee ie
length. tercalare. (After
Coal measures of Nebraska, Illinois, Pennsyl- Meek and Worth-
vania, and West Virginia. Soe ne

‘es

319. S. mediale M. and W. (Fig. 1010, a, 4.) Carbonic.
Subovate, spire short, gently convex, body whorl moderately
ventricose, columellar fold obtuse, notch shallow.

702 NORTH AMERICAN INDEX FOSSILS.

Ps

Coal measures of Illinois, Indiana, Ohio, Iowa, and Missouri.

320. S. texanum Shumard. (Fig. 1010, ¢, d.) Carbonic.
Shorter and more globose; notch strong; columellar callus
strong.
Coal measures of Texas and Illinois.

321. S. primigenium (Conrad). (Fig. 1010, ¢.) Carbonic.

Fic. 1010. a, 6, Spherodoma mediale; c,d, S. texanum,; e, S. primigenium, f, S.
ponderosum. (After White, 13th Ind. Rep.)

Larger, and with scarcely developed columellar fold; thick
shell; otherwise like preceding.

Coal measures of Pennsylvania, Ohio, Indiana, Illinois, lowa,
Missouri, and Arkansas.
322. S. ponderosum Swallow. (Fig. roto, /) Carbonic.

Very large, with deeply sinuous inner lip but no fold; whorls
convex, embracing to above ambitus.

Coal measures of Kansas, Iowa, Missouri, and Ohio.

Family TrocHipa Adams.
XC. GIBBULA Risso.
Trochoid, rarely round-whorled, usually umbilicated shells, em-

bracing to ambitus, with angle and aperture rounded. Tertiary—
Recent.

GASTROPODA—TROCHIDE. 703

323. G. glandula (Conrad). (Fig. ro1t, a.) Eocenic.
With deeply impressed suture and numerous fine spirals ; several

angulations due to coarser spirals ; right lip toothed at base within.
Aquia formation, Maryland, etc.

XCI. Cariiostoma Swainson.

Trochoid shells, with abrupt basal deflection, peripheral keel,
and flattened shoulders; surface with ribs or spirals. The um-
bilicated forms are referable to Eutrochus A. Adams. _ Triassic—
Recent.

324. C. philanthropus (Conrad). (Fig. 1011, 2.) Miocenic.

With pronounced peripheral keel, the upper spirals beaded or

e cd gets a 2
Fic. 1011. a, Gibbula glandula, X 4; 6, Calliostoma philanthrofus, x 43 ¢, C.

eboreum, X 3%; ad, C. aphelium, <2; e-g, C. (Eutrochus) humeli, x $. (After
Martin, Md. Survey. )

nodulated. Some varieties have three beaded or nodulated spirals,
with sometimes intercalated smaller smoother ones.
Chesapeakean (St. Mary’s, Choptank, and Calvert formations)
of Maryland.
325. C. eboreum (Wagner). (Fig. Iorl, c.) Miocenic.
Mostly smooth, with faint concavity in upper part of shoulder,
and, rarely, fine spirals, except below the obtuse keel, which is
seen on the body whorl. (C. aphelium Dall (Fig. 1011, @) has
somewhat more rounded whorls and subsutural row of white spots.)
Choptank and Calvert formations of Maryland.
326. C. (Eutrochus) humile (Conrad). (Fig. 1011, e-g.)
Miocenic.
Umbilicated, broad, low-spired; keel faint; spirals fine ; aper-
ture subrhomboidal.
St. Mary’s formation, Maryland; common.

704 NORTH AMBRICAN, INDEX. FOSSILS.

XCII. MARGARITA Leach.

Trochoid umbilicated shells, with rounded whorls and impressed
suture. Cretacic—Recent.

327. M. ornatissima (Gabb). (Fig. 1012.)
Cretacic.
Of naticoid form, umbilicus moderate, apical
angle less than in J/. abyssina, suture moderately
impressed, surface finely spiralled.

Fic reyes ite Nanaimo group of Vancouver ; Chico of Cali-
garita ornatissima, fornia, etc.
enlarged. After : .
Gabb ) ( 328. M. abyssina (Gabb). (Fig. 1013.)
Cretacic.

Four or more volutions; apical angle 70° or 75°; umbilicus

Fic. 1013. Margarita abyssina. (After Whitfield. )

broad and open; shell thin, with very fine spirals, and apparently
a stronger peripheral one.
Ripleyan of New Jersey.

Family ADEORBIID Fischer.
XCIII. Trrnostomata Adams.

Low-spired or discoidal shells, with the broad umbilicus covered
by callus in the adult ; whorls flattened vertically ; surface smooth.
Miocenic—Recent.

329. T. nanum (Lea). (Fig. 1014.) Miocenic.

ral

FIG. 1014. Zeinostomata nanum, much enlarged. (Md. Survey.)

Shell smooth and highly polished, umbilicus covered by thick
callus, bounded by faint impressed line; spire very low.
Chesapeakean of Atlantic coast.

GASTROPODA

ADEORBIIDZ—NERITOPSIDZ. 705

330. T. milium Dall. Miocenic—Pliocenic.
Of three whorls; suture not impressed; open umbilicus of
young bounded by obscure angular ridge; in adult, with callus
having concave surface ; aperture nearly round.
Chesapeakean of North Carolina, Pliocenic of Caloosahatchie and
Shell Creek, Florida.

XCIV. ApvEoRBIS Wood.
In form like the preceding, but with large open umbilicus and
surface generally spirally sculptured, often angulated, and some-
times ribbed. Oligocenic—Recent.
331. A. supranitidus Wood. (Fig. 1015.)
Oligocenic—Recent.
With three strong carinz, one medially placed,

and one each on upper and lower side; surfaces
between mostly flat.

Oligocenic of Santo Domingo and of Florida la
ie av i

(Chipola beds) ; Chesapeakean of Maryland and
North Carolina; Pliocenic (Waccamaw beds) of
South Carolina and of Europe. Recent on both
sides of the Atlantic. )

332. A. concavus Lea. Miocenic—Pliocenic.
Smooth, except for angulated periphery, with |
flat spire and strongly embracing whorls, large Fic. 1015. Ade-
part of aperture being applied to the body. a Bie teak
Chesapeakean of Virginia and North Caro- ao eR
lina; Pliocenic of North Carolina and Florida.

Family NErRITopsID# Fischer.
XCV. NeEriTopsis Grateloup.

Naticoid shells, non-umbilicate, with depressed spire and large
body whorl; surface with ribs and spirals; inner lip thick, angu-
larly emarginate in the middle. Operculum calcareous, not spiral.
Triassic—Recent.

333. N. biangulata Shumard. Cretacic.

Depressed, wider than high, spire about one fifth of the height
of shell. Volutions three to three and one half, angulated, with
narrow, flat shoulder, declining very gradually from angle of

706 NORTH AMERICAN INDEX FOSSILS.

periphery to suture. Body whorl very convex, angulated below
as well as above, but less sharply ; surface with coarse, oblique
strie of growth; height 1.1 in., width 1.42 inches.

Eagle Ford formation of Texas.

Family NERririp& Lam.
XCVI. Nerita Linn.

Semi-globose, non-umbilicate, naticoid shells, with minute spire
and large body whorl; inner lip callous, and
with straight, commonly denticulate border.
Triassic ?—Holocenic.

334. N. nodilirata Cragin. (Fig. 1016.)
Jurassic.

Fic. 1016. Nerifano- With strong rounded folds on upper part of
dilirata. (After Cragin,

Bull, U. $. G: $,, 266.). WHOIS.

Malone formation of Texas.
335. N. nebrascensis M. and H. (Fig. 1017, a-c.) Jurassic.
Small; inner lip smooth; surface with zigzag color bands.
Upper Jurassic ? of Dakota (Black Hills).

336. N. (Neretina) naticiformis White. (Fig. 1017, d, e.)

Cretacic.
Small, surface smooth, inner lip faint.
Bear River formation of Wyoming and Utah.

337. N. crebrilineata White. (Fig. 1017, 7 g.) Cretacic.

Fic. 1017. a-c, Merita nebrascensis; d,e, N. (Neritina) natictformis; f, g, N.
crebrilineata ; h, i, N. pisum. (After White, U. S. G. S.)

Larger than preceding ; spire minute ; callus of inner lip strong ;
surface with regular fine spirals.
Laramie of Wyoming and Colorado.

GASTROPODA—NERITIDA:—FISSURELLIDZ.. 707

338. N. pisum Meek. (Fig. 1017, %, 2.) Cretacic.
Small (height 0.22 in.), smooth, with four denticles on inner lip,
in groups of two.
Colorado of Coalville, Utah.

XCVII. VELATELLA Meek.

Neritoid shells, depressed-convex above, flattened on apertural
side, with large inner lip; enlargement of body whorl such as to
- give the shell a patelliform aspect ; with minute, slightly incurved
apex; Cretacic.

339. V. patelliformis Meek. (Fig. 1018, a, 4.) Cretacic.

)

4 i

B31

E47"

ZB,
ABS

BZA

A
AA
A P,
Zi ¢

a
Z:

Fic. 1018. a,, Velatella patelliformts; c, V.carditoides ; d-h, V. bagtistd: (After
White, U.S. G..S:)

Small, thick, oval, almost perfectly bilateral ; inner lip broad
and thick, faintly denticulate, extending more than half the length
of the base of the shell; surface with growth lines.

Lower Colorado of Coalville, Utah, and Bear River, Wyoming.
Common.

340. V. carditoides Meek. (Fig. 1018, c.) Cretacic.

Surface with well-marked radiating rib-like spirals.
Upper Colorado, Coalville, Utah.

341. V. baptista White. (Fig. 1018, d—-/.) Cretacic.
Enrolled apex prominent; surface smooth except for color
bands, which are sometimes preserved. Edge of inner lip smooth.
Laramie of Wyoming and the region of the Bow and Belly
rivers, Canada.

Family FissuRELLID# Risso.
XCVIII. Emarcinora Lam.
Subconic shells with submedian or posterior apex, and anterior

marginal slit. (These characters are also those of young /zssu-
videa.) Carbonic—Recent.

708 NORTH AMERICAN INDEX. FOSSILS.

342. E. arata Conrad. (Fig. 1019.) Eocenic.
Oblong-ovate, slit large but not deep, on {narrower end ; apex

central, strongly incurved ; surface with angular ridges, largest on

posterior (broad) end and increasing by intercalation or division.
Claibornian of Alabama, rare.

343. E. marylandica Martin. (Fig. 1020.) Miocenic.

Fic, 1019. Emarginula arata, Fic. 1020. LEmarginula mary-
(After Conrad. ) landica. (Md. Survey. )

Smaller than preceding and more nearly oval, beak nearer the
posterior end, radiating ridges round, uniform on all parts of shell,
distant with smaller ones between.

Choptank formation of Maryland.

XCIX. FissuripEA Swains. (/issurella in part of authors.)

Subconical or subcapuliform shells of oval base and the apex
anterior to the middle and replaced by a perforation with a callus
on the interior. Carbonic (?)—Recent. ,

344. F. griscombi (Conrad). (Fig. 1021, a-d.) ‘Miocenic.

Fic. 1021. a-d, Fissuridea griscombi, a, b, XK %, ¢, d, young, XK 5; ¢, f, &. marylna-
dica, X %. (Md. Survey. )

Young with enrolled protoconch, later resorbed by advancing
fissure ; moderately high, subconical laterally compressed surface,
plice strong, alternating, generally two or three finer ones be-
tween two coarser.

Chesapeakean of Maryland and New Jersey.

GASTROPODA—EULIMIDA—PY RAMIDELLIDZ. 709

345. F. marylandica (Conrad). (Fig. 1021, ¢, /) Miocenic.
Differs from the preceding chiefly in its finer radiating plications
or striations, in not being compressed laterally and in the larger
apical fissure.
Chesapeakean of Atlantic coast.

Family Eurimip Fischer.
C. Eutima Risso.

Small, turreted, smooth and lustrous non-umbilicated shells
with dextral protoconch. (Acolumellar tooth occurs in Syrnola
Adams.) Triassic—Recent.

Miocenic.

Fic. 1022. a, Eulima eborea » 6, Miso lineata; c, Turbonilla nivea,; d, T. inter-
rupta,; e, Chrysallida melanoides ; f, Odostomia conoidea. (After Md. Survey. )
Long, slender (13 whorls), sides of whorls flat, suture flush,

surface smooth, base of body whorl curving.

St. Mary’s and Calvert formations of Maryland.

CI. Niso Risso.
Like the preceding, but deeply umbilicated. Triassic—-Recent.
347. N. lineata Conrad. (Fig. 1022, 0.) Miocenic.
Sides (shoulders) of whorl nearly flat and smooth ; peripheral
angulation pronounced, generally visible only on body whorl.
Calvert formation of Maryland.

Family PyRAMIDELLID® Gray.
CII. TursBonicya Risso. (Chemnitzia d’ Orb.)
Like Aulima, but with depressed suture, protoconch coiling in
vertical plane, and smooth or ribbed. Columellar tooth present
in Pyrgulina. Tertiary—Recent.

710 NORTH AMERICAN INDEX FOSSILS.

348. T. nivea Stimpson. (Fig. 1022, c.) Miocenic ?—Pleistocenic.
Long and slender with regular rigid vertical ribs.
St. Mary’s of Maryland, Pliocenic and Pleistocenic of the
Carolinas.
349. JT. interrupta (Totten). (Fig. 1022, @.) Miocenic.
With narrower intercostal spaces occupied by interrupted spirals ;
spirals marked on base of body whorl.
St. Mary’s, Choptank, and Calvert formations of Maryland.

CIII. CurysaLiipa Carpenter.
Like Zurdonilla but with both ribs and spirals and columellar
tooth. Tertiary.
350. C. melanoides (Conrad). (Fig. 1022, ¢.) Miocenic.
Small, rather broad; spirals on side (shoulders) of whorls
nodulated by ribs ; simple on body of whorl.
St. Mary’s formation of Maryland.

CIV. OpostomiA Fleming.

Like Zulima, but with more depressed sutures and columellar
tooth; surface smooth. Differs from Syrnola in convex whorls
and depressed sutures. Tertiary—Recent.

351. O. conoidea (Brocchi). (Fig. 1022, /) Miocenic.

Small, short, with elongate body whorl ; angle of young greater
than of adult. |

Choptank and St. Mary’s(?) of Maryland; Calvert of New
Jersey ; Sub-Apennine of Italy.

Family ScaLARuD# Broderip.
CV. ScarariaA Lam. (Scala Klein.)

Turreted non-umbilicated shells, with deep sutures and convex
whorls, marked at regular and frequent intervals by smooth varices.
Triassic—Recent.

352. S. sillmani Morton. (Fig. 1023.) © Cretacic.

Broad-spired and rather closely coiled, with very oblique sharp
varices and very fine spirals. Internal mold smooth, with deep
sutures.

Ripleyan of New Jersey and Alabama.

353. S. sayana Dall. (Fig. 1024, a.) Miocenic.

GASTROPODA—SCALARIIDZ—SOLARIIDZA 71k

Varices about 9 (7 to 11) toa whorl, sharp and slightly oblique ;
interspaces smooth.
St. Mary’s and Choptank formations of Maryland.
354. S. (Sthenorhytes) pachypleura Conrad. (Fig. 1024, 0.)
Miocenic.
Short and thick, with large body whorl. Varices thick, sub-

Fic, 1023. Scalaria silimant. Fic. 1024. a@, Scalaria sayana eo) 6): Se
(After Whitfield. ) (Sthenorhytes) pachypleura. (Md. Surv. )

spinose above; body whorl with a cingulum or discontinuous
spiral in the interspaces ; mouth nearly circular, lips expanded.
St. Mary’s, Choptank, and Calvert formations of Maryland, etc.

Family SoLrariup# Chenu.
CVI. Sorarium Lam.

Depressed-conical to flat and deeply umbilicated shells with
strong peripheral angulation in the most specialized species ; nuclear
whorls heterostrophic ; surface smooth or with spirals, etc. ; aper-
ture quadrilateral ; umbilicus with notched margins or spiral ;
operculum horny. Jurassic—Recent.

355. S.? planorbis Roem. (Fig. 1025.) Comanchic.

= TERRI
iad 2 Be

\ Lf eS a 2 aN ie
MSG =r Peat a

Fic. 1025. Solarium planorbis. (After Roemer. )

Depressed, spire flat or sunken; whorls dorsoventrally com-
pressed, slightly embracing ; surface smooth except for a line of
notches along the umbilical edge.

Edwards limestone of Texas, etc.

712 NORTH AMERICAN INDEX FOSSILS.

od
.

356. S. alveatum Conrad. (Fig. 1026.)
Eocenic.
Spire trochiform; sutures not impressed ;
whorls flat, smooth, with two spirals near
suture ; angulation sharp, base flattened with

peripheral grooved lines ; umbilicus profound,
margined by ring of triangular dentations.
Abundant in Claibornian of Alabama.

357. S. trilineatum Conr. (Fig. 1027.)
Miocenic.
Periphery with smooth carina, beneath
_ which on the body is another smooth carina ;
r ee aed gently convex shoulder with two beaded
rad. ) spirals, one close to each bounding suture.
Calvert formation of Maryland.

Dn
SO \\
= x hn Wh

Nee

CoA

MAR

Fic. 1027. Solarium trilineatum. (After Md. Survey.)

Family CapuLip# Cuvier.
CVII. Carutus Montfort.

Conical or cap-shaped shells with apex curving towards the pos-
terior end, and often slightly enrolled.
A horse-shoe shaped muscle impres-
sion on the interior ? (This is probabably
a polyphyletic group; the Paleozoic
species referred here belong elsewhere.)
Triassic—Recent. |

358. C. expansus (Whitf.). (Fig. 1028.) a. yoo8, Capt joni
Eocenic. (After Harris. )
Small, broadly expanded, apical volu-
tions one to two; surface with growth lines.
Chickasawan (Lignitic) of Alabama.

GASTROPODA—CAPULIDE. 713

CVIII. Caryprr#a Lam. (Galerus Gray.)

Thin, conical spiral shells, with the last whorl greatly expanded,
bearing a wide aperture with flat periphery ; whorls often spinose.
Cretacic—Recent.

359. C. centralis Conrad. (Fig. 1029, a—c.)
Oligocenic—Miocenic.
Conical, with apertural rim projecting beyond the last whorl ;
surface smooth except for a few irregular spiral lines and growth
lines.

Chipolan of Gulf States ; St. Mary’s of Maryland.
360. C. aperta Solander. (Fig. 1029, d.) Miocenic-

FIG. 1029. a-c, Calyptrea centralis, nat. size; ad, C. aperta, X 24. (Md. Survey.

Large, gibbous, with regularly enlarging spirals, the later ones
strongly spinose.

Choptank and Calvert formations of Maryland; Shiloh marls
of New Jersey.

CIX. Creprputa Lam.

Slipper-shaped, with beak nearly or quite marginal, and often
enrolled. The elongate aperture is partly covered
by a platform or thin lamellar expansion of the
inner lip. Cretacic-Recent.

361. C. lirata Conrad. (Fig. 1030.) Eocenic.
Beak much produced, strongly curved to side
and forward, with subspiral apex; form narrow,
elongate and deep; surface with irregular striz or
coste and transverse wrinkles.
Claibornian of Alabama, very common.

. FIG. 1030.
ape C. Plana may: ee. pear re is ‘ . Crepidula lirata.
Oligocenic—Recent. (After Conrad.)
Flat; apex marginal, not enrolled; shell elon-

gate; platform covering about half the length of shell.

714 NORTH AMERICAN INDEX FOSSELS.

Chipolan of Gulf States ; St. Mary’s and Calvert formations of
Maryland ; Miocenic and Pliocenic of Virginia, the Carolinas, etc.;
modern seas. |
363. C. fornicata (Linneé

TS INN

b s
Fic. 1031. a, 6, Crepidula plana, nat. size; c, d, C. fornicata, enlarged. (Md.
Survey. )

Convex, with enrolled apex, and deep-set platform.
Widely distributed in marine Miocenic and Pliocenic of America
and abundant on modern coasts.

CX. CrucisuLtum Schum.
Patelloid shells with coiled protoconch and strongly expanding
body whorl. Platform deeply concave, producing the cup and
saucer aspect. Tertiary—Recent.

364. C. chipolanum Dall. Oligocenic.
Like C. auricula, but radiating striz sharply cut and stronger,

Fic. 1032. a, 6, Cructbulum costatum, XK 74; c-e, C. pileolum, c, young, XK 1% ;
a, e, adult, X 2%. (Md. Survey. )

though not as strong as in C. pileolum ; rarely dichotomous.
Chipolan of Gulf States.

365. C. costatum (Say). (Fig. 1032, a, 0.) Miocenic.
Mostly smooth, with faint costa near margin, cup attached on

ne side.
O >

GASTROPODA—NATICIDZ. 716

Miocenic of Maryland.
366. C. pileolum (Lea). (Fig. 1032, c—e.) Miocenic.

With strong plications, often extending to beak; cup free at
periphery in adult.

St. Mary’s of Maryland, Virginia, etc.

367. C. auricula Gmelin. Pliocenic- Recent.

Depressed, with fine radiating, frequently dichotomous lines on
upper surface.

Waccamaw beds of South Carolina; Caloosahatchie beds of
Florida. Living west coast of Florida to northern Brazil, 25 to
100 fathoms. |

Family Naticip# Forbes.
CXI. Sicaretus Lam.

Broad-spired naticoid shell with rapidly enlarging
whorls, distended aperture with horny operculum,
and spiral surface sculpture. Tertiary—Recent.

368. S. bilix (Conr.). (Fig. 1033.) Eocenic.

Rotund ; umbilicus large; spirals crowded and in

: FIG. 1033.
pairs. Sigaretus btlix.
Chickasawan and Claibornian of Alabama. (After Harris. )

369. S. fragilis (Conr.). (Fig. 1034.) Miocenic.

Fic. 1034. Sigaretus fragilis. (Md. Surv.)

Larger than preceding (22 mm. high), aperture about four fifths
of length of shell; inner lip less prominent, umbilicus small,
spirals uniform, crowded.

Miocenic of Atlantic coast.

CXII. Vanikoropsis Meek.

Practically non-umbilicated shells of naticoid form; inner
lip thin, smooth, adhering to columella; surface with spirals and
oblique rib-like folds.

716 NORTH AMERICAN INDEX FOSSILS.

370. V. suciensis White. Cretacic.
Small, subovoid, with small spire and blunt apex ; volutions
four or five; body whorl much expanded, with large oval aper- —
ture ; surface with fine spirals throughout.
Nannaimo of Vancouver ; similar beds of California, etc.

371. V. tuomeyana (M. and H.). (Fig. 1035.) Cretacic.

Fic. 1035. Vantkoropsis tuomeyana, with enlargement of surface. (After Meek. )

Thick, few whorled, last whorl large, rounded ; aperture ovate ;
faint umbilical indentation ; spirals numerous; ribs on body whorl
only.

Claggett formation of Montana and Canada.

CX. Navrica icam,

Varying in form from globose to pyramidal, with smooth and
lustrous (rarely striated) surface, typically with umbilicus, which
is often more or less covered by a callus; some groups non-
umbilicated. Aperture semicircular to oval with thickened inner

Fic. 1036. Natica williamst. (After Cragin, Bull. U. G. S., 266.)

and sharper outer lip. (A number of subgenera are recognized.)

Triassic—Recent.
372. N. williamsi Cragin. (Fig. 1036.) Jurassic.
Non-umbilicate, of five whorls, the spire short, of much em-
.

GASTROPODA—NATICIDEA. IVT

braced somewhat sunken whorls and large body whorl, with long
aperture narrowing upwards.
Malone formation, Texas.

373. N. (Lunatia) pedernalis Roemer.
ig. 1037.) Comanchic.
Very large, whorls embracing to a

little above the middle, last one ven-

tricose, somewhat separated.
Glen Rose, Comanche Peak of

Texas, etc. 7

374. N. (Lunatia) halli Gabb. (Fig.
1038.) Cretacic.
Spire elevated, height about one

and one half times the diameter;

suture of internal molds deep; um- 4. ENED ere Ne ee
bilicus large; aperture acute above, pedernalis, x %? (After Hill.)
acutely rounded below.

Ripleyan formation of New Jersey, Alabama, Mississippi.

Fic. 1038. Lunatia halli. (After Whitfield. )

375. N. (Lunatia) avellana Gabb. (Fig. 1039.) Cretacic.
Subglobose, embracing to above the ambitus, with
impressed suture, moderate spire, large, minutely
umbilicated body whorl; inner lip slightly callous,
aperture acute above.
Horsetown of California, etc.

370. N. (Lunatia) shumardiana Gabb. (Fig. 1040.) ey

Cretacic-Eocenic. Fic. 1039.

Body whorl more convex than in preceding ; base oe
more extended at aperture; inner lip more strongly Gabb.)

callous; umbilicus small.

aaa 23 “a gig
an seal

718 NORTH AMERICAN INDEX FOSSILS.

Nanaimo of Vancouver; Chico and Tejon of California.
377. N.(Lunatia) marylandica Conr. (Fig. 1041.) Eocenic.
Suborbicular to subovate, with low, broad spire of five volu-

Fic. 1040. Lunatia shumardiana. Fic, 1041. Lunatia marylandica. (Md.
(After Gabb. ) Survey. )

tions; whorls slightly depressed below the suture; the aperture
with a faint posterior canaliculation ; umbilicus moderate.
Nanjemoy and Aquia of Maryland, Virginia, etc. A closely
related form, JV. emznu/a, occurs in the Chickasawan and Clai-
bornian of Alabama and Texas.
378. N. (Lunatia) semilunata Lea. (Fig. 1042.) Eocenic.
Smaller than JV. /eros and with higher spire; callus of inner lip
partly covering umbilicus, which is normally surrounded by a
carination.
Chickasawan (Lignitic) of Alabama and Texas.

379. N. mediavia Harris. Eocenic.

Fic. 1042. Vatica Semtlunata. Fic, 1043. Vatica ( Cryptonatica) flori-
(After Harris.) dana, X4. (After Dall.)

With about 5 whorls, slightly shouldered or flattened near the
depressed sutures; large globular body whorl; aperture ellip-
tical, with thickened lip forming a varix. |

Midwayan of Georgia and Alabama.

380. N. (Ampullina) mississippiensis Conrad. Oligocenic.
Large; spire somewhat elevated ; suture deeply canaliculate,;

a a |.

GASTROPODA—NATICIDE. 719

body whorl somewhat depressed-convex ; aperture ovoid ; inner
lip expanded over umbilical region.
Claibornian of Alabama ; Upper Eocenic of Mississippi.

381. N. (Cryptonatica) floridana Dall. (Fig. 1043.) Oligocenic.
Differs from WV. duplicata in its somewhat more globular form,
more elongate aperture, and smaller callus; from JV. eros, in its
smaller size, absence of shoulder concavity or flattening, somewhat
narrower aperture, and the callus.
Chipolan and Orthaulax beds of Florida.

382. N. (Lunatia) heros (Say). Miocenic—Recent.

Large, with globular whorls strongly embracing, and generally
slightly depressed below the suture, especially in adult ; umbilicus
large, scarcely encroached upon by callus of inner lip.

Chesapeake group of Atlantic coast; Pliocenic of southern
United States ; Pleistocenic of South Carolina and Canada. Widely
distributed on modern Atlantic coast of North America.

383. N. (Neverita) duplicata. Miocenic—Recent.

Strongly embracing, spire with scarcely impressed sutures ;
callus of inner lip large, nearly or quite covering the umbilicus.

Chesapeake of Atlantic coast; Pliocenic of southern United
States ; Pleistocenic of Atlantic coast from Virginia south ; Recent
from Massachusetts Bay southward.

CXIV. Gyropes Conrad.
Naticoid shells with broad and deep umbilicus generally sur-
rounded by an angulation, and a flattened or concave band at the
suture in the later whorls. Cretacic.

384. G. depressa Meek. (Fig. 1044, @.) Cretacic,

\\

\

Fic. 1044. a, Gyrodes depressa,; 6, ¢, G. conradi. (After Stanton.)

Spire depressed or somewhat elevated. Body whorl rapidly
enlarging, subangular or narrowly rounded below, with large um-
bilicus ; aperture ear-shaped.

720 NORTH AMERICAN INDEX FOSSILS.

Colorado formation of Colorado, Utah, etc.

385. G. conradi Meek. (Fig. 1044, 4, c.) Cretacic.

Low spire, broadly rounded body whorl with a subsutural angu-
lation and a narrow flattened or concave band between this and
the suture ; strongly carinate in the central basal portion, while a

Fic, 1045. Gyrodes crenata. (After Whitfield. )

further angulation margins the broad funnel-shaped umbilicus ;
aperture subrhombic, about twice as wide as high.
Colorado formation (Benton, and Pugnellus sandstone), of South
Dakota and Colorado.
386. G. crenata Conrad. (Fig. 1045.) Cretacic.
Like the former but with the carination below the suture crenu-
lated or nodulated, generally not shown in the internal mold.
Ripleyan of New Jersey, Alabama, Mississippi.

387. G. abyssina (Morton). (Fig. 1046.) Cretacic.

Fic. 1046. Gyrodes abyssina. (After Whitfield. )

Like the preceding, but without the basal carination.
Ripleyan of New Jersey, Alabama, Texas.

388. G. petrosa (Morton). (Fig. 1047.) Cretacic.
Like G. adyssina but smaller and with the space below the |
suture flat instead of concave.

her.

ee a eee ee ee

GASTROPODA—NATICIDZ.. 721

Ripleyan of New Jersey, Alabama, Mississippi, Texas.

389. G. conradiana Gabb. Cretacic.
Like G. conrad: but without the inner angulation around the
umbilicus.
Vancouver group of Washington and Canada, Chico of
California. |

Fic. 1047. Gyrodes petrosa. (After Whitfield. )

390. G. expansa Gabb. (Fig. 1048.) Cretacic.
Whorls flattened at suture and flat or slightly concave below the
sutural angulation, basal portion without angulation.
Chico of the Pacific Coast.

=
-

Fic. 1048. Gyrodes expansa. (After Gabb.)

. CXV. Amavuropsis Morch.

: High-spired, non-umbilicate, sides of whorls more or less flat-

_ tened; those of the body whorl often parallel to axis; sutural

flattening or shelf often nearly rectangular to sides.

~ Comanchic-—Tertiary.

: 391. A. avellana Roemer. (Fig. 1049.)

| Comanchic.
Small, subglobular with five or six whorls closely

embracing the last one. Large, rounded aperture, bis i
: . - MaUropsis
semilunar, narrowing upwards; outer lip slightly joing.

reflexed, inner lip strong ;_ surface smooth. (After Roe-
Edwards limestone of Texas. mer. )

722 NORTH AMERICAN INDEX FOSSILS.

392. A. bulbiformis (Sowerby). (Fig. 1050.) Cretacic.

Fic, 1050. Amauropsis bulbiformis, X 74. (After Stanton. )

Large, whorls moderately convex, slightly
depressed below sutural angulation; sutural
shelf depressed or canaliculate, outer lip nearly
vertical.

Colorado group (Pugnellus sandstone and
Benton shale) of Colorado, Widely distribu-
ted in Europe and Asia.

393. A. alveata (Gabb). (Fig. 1051.)
Cretacic (?)—Tertiary.
Fic. 1051. Amauropsis Like preceding but with more convex
atveata. (After Gabb.) horls and broader not depressed sutural
shelf.
Chico (?) and Tejon formation of Pacific coast.

Family Rissorp# Troschel.
CXVI. Ruissoina d’Orbigny.

Small turreted shells with arcuate outer lip thickened and
slightly notched or drawn out below, and angular above. Sur-
face with ribs, more rarely smooth. Jurassic~Recent.

394. R. levigata Adams. Oligocenic—Recent.
Smooth, with sutures scarcely depressed ; body whorl rounding
below; protoconch of several whorls, shaped like a small Vertigo.
Chipolan and Caloosahatchie beds of Florida ; living from Cape
Hatteras to the Antilles, also Indo-Pacific.

a»

toy. 9 iA hn. Fd Bh eer a

GASTROPODA—RISSOIDZ—XENOPHORIDE. 723

395. R. decussata Montague. Oligocenic—Recent.
Moderately high-spired, whorls slightly rounded, sutures
slightly impressed ; fine, flat, slightly curved ribs, fine spirals vis-
ible only between the ribs, except near the base of body whorl ;
anterior notch faint, outer lip moderately thickened, length 7-8 mm.
Chipolan (Oligocenic) beds of Florida; Miocenic of France,
Italy, and Austria; Coloosahatchie (Pliocenic) of Florida and
Italy; Recent: Antilles, Mediterranean, Panama, Indo-Pacific
region.
Family XEXOPHORID# Desh.
CXVII. XeENopHoRA Fischer.

Broadly conical or trochiform, whorls flat, abruptly angulated ;
angulation often prolonged as a sharp, sometimes spinous, rim or
carina; basal portion flat or rounded, surface commonly with
agglutinated foreign particles. Cretacic—Recent.

396. X. leprosa (Morton). (Fig. 1052, 4.) Cretacic.

Fic. 1052. LEndoptygma umbilicata (left); Xenophora leprosa (right). (After
Whitfield. )

Carina apparently absent, the internal molds appearing rounded
at the angle ; embracing of whorls not quite to angle ; surface gen-
erally showing cicatrices where foreign particles were attached.

Ripleyan of New Jersey, Alabama.

397. X. (Endoptygma) umbilicata (Tuomey). (Fig. 1052, a.)
Cretacic.

Smaller than X. /eprosa, with open umbilicus and a revolving
furrow on basal portion, a third of the distance from umbilicus to
‘periphery.

Ripleyan of New Jersey, Mississippi, Alabama.

398. XK. conchyliophora (Born.). (Fig. 1053.)
Oligocenic—R ecent.

With moderately overhanging carina, emarginate on outer

724 NORTH AMERICAN INDEX FOSSILS.

(lower) side ; umbilicus covered by callus. Generally covered
with shell fragments.

Chipolan (Oligocenic) of Gulf States ; Chesapeakean (Miocenic)
of Atlantic coast.

Fic. 1053. Xenophora conchyliophora, K 24. (Md. Survey.)

Family VaALvATID# Gray.
CXVIII. Varvata Miller.

Small umbilicated shells, of naticoid form with few regularly en-
larging whorls, forming a conical or discoidal spire ; aperture
circular, peristome continuous; operculum horny, multispiral.
Habitat fresh water. Jurassic—-Recent. .
399. V. scabrida M. arfd H. (Fig. 1054, ac.) Jurassic.

Minute, rather loose-coiled, with obtuse conical spire and deeply
impressed sutures ; aperture circular.

Como (Atlantosaurus) beds of Black Hills, Morrison of
Colorado.

400. V. nana Meek. (Fig. 1054, d, ¢.) Cretacic.

Fic, 1054. a-c, Valvata scabrida; d, e, V. nana, f, g, V. subumbilicata. (AN
enlarged.) (U.S. G. S.)

Minute, spire very low, approaching flatness, whorls in contact

but not impressed.
Coalville (Coloradoan) of Utah.
401. V. subumbilicata M. and H. (Fig. 1054,/, g.) Cretacic.
Larger than preceding (nearly three times as large), few-whorled,
spire low, umbilicus small.
Laramie formation of the upper Missouri River region.

:
|
|

GASTROPODA—VIVIPARID. 726

Family VIVIPARID# Gill.
CXIX. Viviparus Montford. (Paludina Lam.)

Conical or turbinate shells with acute spire of rounded or flat-
tened whorls; suture depressed, and often accentuated by thick-
ening of shell below its aperture, with continuous peristome ; um-
bilicus minute or absent. Angulated forms are generally referred
to 7Tulotoma,; the smooth, thick shelled species with thick inner
lip are referred to Campeloma Rafinesque. Habitat fresh water.
Jurassic—Recent.

402. V. gilli M. and H. (Fig. 1055, a, 0.) Jurassic.
Small, of about four rounded volutions, increasing rather rapidly ;

suture simply impressed ; aperture oval; growth lines faint.
Upper Jurassic (Morrison) of Black Hills.

403. V. couesii White. (Fig. 1056, a.) Cretacic.

Fic. 1055. a, 6, Viviparus gilli; c, V. reynoldsianus, d,e, V. trochiformis; f, g,
V. formosa; h, t, V. conradi, (U.S. Geol. Surv.)

Large, high-spired, whorls round, sutures deep, body whorl
somewhat flattened and slightly shouldered without angulation.
Bear River formation of Wyoming.

404. V. conradi M. and H. (Fig. 1055, 4, z.) Cretacic.

Apical angle from 45-60 degrees; sutures scarcely impressed,
whorls nearly flat, angulated below.

726 NOKTH AMERICAN INDEX FOSSILS.

Judith River formation of Wyoming, Montana, and Bow River
region, Canada.
405... leat M: and H.. (Fig..1056, 2, c.) Cretacic.

Broader and shorter than V. conradi ,; sutures somewhat more
impressed, whorls gently rounded not angulated below, faintly
umbilicated.

Laramie of Colorado, N. Dakota and the Upper Missouri River
region generally, also the Bow River region and elsewhere in
Canada.

406. V. leidyi M. and H. (Fig. 1056, 2.) Cretacic.

Fic. 1056. a, Viviparus couesii; b,c, V. leat, d, V. leidyt; e, V. plicapressus ; Fi ks
V. prudentia; h-k, V. ( Tulotoma) thompsoni. (After White, U. S. G. 5.)

Large, apical angle about 45 degrees ; sutures impressed, whorls

uniformly rounded.
Laramie of Dakota and Montana, and the Upper Missouri river

region generally. ‘

GASTROPODA—V IVIPARIDZ. 727

407. V. plicapressus White. (Fig. 1056, ¢.) Cretacic.

High-spired, whorls embracing to ambitus, slightly shelved at
the suture; aperture nearer axial line than in most species.

Laramie of Colorado and Wyoming.

408. V. prudentia White. (Fig. 1056, 7% g.) Cretacic.

Broad and low-spired, apical angle approaching 90 degrees ;
whorls few, round, suture moderately impressed.

Laramie of Colorado and the Canadian region.

409. V. raynoldsiannus M. and H. (Fig. 1055, ¢.) Eocenic.
Smooth, round-whorled with apical angle 60-65 degrees, nearly
circular aperture and small umbilicus. |

Fort Union beds of Montana, etc.

410. V. trochiformis M. and H. (Fig. 1055, d, ¢.) Eocenic.

With three revolving spirals, or angulations between which the
shell is flattened.

Fort Union beds of Montana. A biangulate mutation occurs in
Wasatch of Utah.

411. V. formosa Meek. (Fig. 1055, f% g.) Eocenic.

Broad with shallow sutures and three to four spirals.

Fort Union beds of Montana.

412. V. (Tulotoma) thompsoni White. (Fig. 1056, 4-2.)

Like V. trochiformis but with more accentuated spirals which in
some of the specialized mutations become more or less strongly
nodose.

CXX. CAMPELOMA Rafinesque.

Like Viviparus but thick-shelled and with thickened inner lip.
Smooth, rarely with exceedingly fine spirals. Cretacic—Recent.
413. C. macrospira Meek. (Fig. 1057, a, 0.) Cretacic.
Large, rather long-spired, volutions round, smooth and with
moderately impressed sutures ; aperture ovate; inner lip thickened.
Bear River (Coloradoan), Wyoming, Idaho, etc.
414. C. vetulum M. and H. (Fig. 1057, ¢, d@.) Cretacic.

Like preceding but smaller and slightly more acute, inner lip
scarcely thickened, umbilical region indented ; surface obscurely
spiraled.

Judith River beds, Montana, and Canada.

415. C. multilineatum M. and H. (Fig. 1057, e-g.) Cretacic.

728 NORTH AMERICAN INDEX FOSSILS.

Rather high-spired, with more or less distinct sutural shelf and
exceedingly fine spiral lines.

Laramie of the Upper Missouri Region, and of the Bow and
Belly River regions of Canada.

416. C. multistriatum M. and H. (Fig. 1057, %.) Cretacie:

FIG. 1057. a, 6, Campeloma macrospira; c,d, C. vetulum,; e-g, C. multilineatum ;
h, C. multistriatum ,; t-k, C. productum, (After White, U. S. G. S.)

Rather small, many-whorled, apical angle about 45 degrees;
sutures impressed, no shelf, whorls round.

Laramie of Colorado, Wyoming, and the Upper Missouri River
region generally.
417. C. productum White. (Fig. 1057, 7-2.) Cretacic.

Long and slender, approaching Gomzobasis. Apical angle 30-40
degrees, in some cases with very faint sutural shelf, rarely faintly
angulate and with few faint spires.

Laramie of the Yellow Stone River region, and in the Bow t
River region and elsewhere in Canada. :

GASTROPODA—TURRITELLIDZ.. 729

Family TurRITELLID Gray.
CXXI. Turriterta Lamarck.

Shell with high turreted and acuminate spire, numerous, variously
spiraled whorls, separated by sutures of moderate depth anda
round, oval, or quadrangular aperture, with thin outer lip and no
plications. 7

418. T. (Mesalia) seriatim-granulata (Roem). (Fig. 1058.)
Comanchic.
Large, slender, elongate, with numerous whorls flattened on the
side, each later projecting basally over the preceding. Alternating
spirals noded, varying in number; the nodes low and round or
elongate, with spirals rather coarse and well separated.
Fredericksburg of Texas; in corresponding horizons of Cali-
fornia, Mexico, etc.

419. T. (Mesalia) belviderei Cragin. Comanchic.

Fic. 1058. Zurritella seriatim-gran- Fic. 1059. Zurritella white. (After
ulata. (After Gabb, Pal. Cal., I.) Stanton. )

Differs from the preceding in its smaller size, finer granules,
which are prominent, numerous, and crowded, their greatest diam-
eter transverse or oblique to the abruptly elevated spirals. Lines
of growth show strong sinuosity in lip.

Kiowa shales of Kansas. Common.

420. T. kansasensis Meek. Comanchic.

Similar to the preceding, but the spirals without nodes or gran-
ulations.

Kiowa shales of Kansas, etc.

421. T. whitei Stanton. (Fig. 1059.) Cretacic.

730 NORTH AMERICAN INDEX FOSSILS.

About thirty slender whorls, when full grown, embracing nearly
or quite to the moderate angulation. Sides (shoulder) flat or
gently convex; primary spirals 6-8, minutely nodose in later

Fic. 1060. TZurritella vertebroides, shell surface, and internal mold. (After
Whitfield. )

whorls and subspinous in adult; secondary spirals generally

present.
Coloradoan of Utah and Colorado.
422. T. vertebroides Morton. (Figs. 1060, 1061.) Cretacic.

Fic. 1061. Zurritella vertebrot- Fic. 1062. TZurritella encrinoides, frag-

des, enlargement of part of surface ment of shell, and enlargement of surface.
of the type. (After Whitfield.) (After Whitfield. )

Slender, long, apical angle about 12 degrees ; volutions gently

GASTROPODA—TURRITELLIDZ. 73

convex with 5 or 6 strong primary spirals, with weaker second-
aries, and still fainter tertiaries. Suture depressed.
Ripleyan (Monmouth) of New Jersey and Alabama.

423. T. encrinoides Morton. (Fig. 1062.) Cretacic.

Center of whorl flattened, basal angle pronounced, whorls em-
bracing to within a short distance of the angle.
About 3 or 4 strong primary spirals, with
strong secondary ones between. Internal
mold more compact than in 7. vertebrotdes.

Ripleyan (Navesink) of New Jersey and
Alabama.

424. T. trilira Conrad. (7. ¢vélineata H. and
Meee Pig. 1063.) Cretacic.
Whorls slightly convex, sutures depressed,

three strong spirals, a fourth generally covered

at the suture.
Ripleyan of New Jersey, Alabama, Missis-

Sippi, Navarro of Texas, Arkansas, etc.

425. T. tippana Conrad. ACETACIC:
Differs from the preceding in the scarcely
depressed suture and in having four spirals, | |
the lower three equidistant, the upper more ROR deg
q cae PP tella trilira. (After
distant and stronger, and in the presence of a Hill. )
few intercalated spirals.
Ripleyan of New Jersey and Mississippi.

426. T. mortoni Conrad. (Fig. 1064.) Eocenic.
Volutions angulated, shoulder slightly concave, with two or

three primary and several secondary spirals. Keel very angulate

in specialized varieties (7. postmortont, Fig. 1064,a). Body whorl,
below angulation, mostly covered by succeeding whorl. Aperture
subquadrangular.

In the lower Pamunkey (Aquia formation) of Maryland and
Virginia — especially abundant on Aquia Creek. Midwayan of
Alabama, Texas, Arkansas, Mississippi, Tennessee. Occurs often
as internal mold (Fig. 1064, 4).

427. T. (Mesalia) vetusta Conrad. Eocenic.

Sutures sharply impressed, but shallow, spirals fine, alternating
in size; ribs arcuate, indistinct, generally obsolete ; whorls slightly

AMERICAN INDEX FOSSILS.

Fic. 1064. TZurritella mortoni, three varieties and internal mold, > % ; @ is mutation
postmortont, X 2%. (Md. Survey. )

angulated just below the suture, aperture obliquely elliptical,
effuse ; inner lip somewhat folded, slightly reflected at the base.
Claibornian of Alabama, abundant.

428. T. humerosa Conrad. (Fig. 1065.) Eocenic.
Whorls nearly flat in the center, with strong primary and fainter
secondary spirals; an angulation near the base, visible only in the
body whorl, and a strong subsutural thickening carinated by two
spirals. Aperture subquadrate.
In the Aquia formation less common than 7. mortont. Mid-
wayan, of Texas, Alabama, Arkansas.

.

429. T. tampe Heilprin. (Fig. 1066.) Oligocenic.
Center of whorls slightly concave with a zone of two sunken
spirals or three spiral grooves, basal angle pronounced and slightly
carinate. Sutures scarcely depressed except final gerontic stages.
Whole surface of shell covered with fine, sharp but almost micro-
scopic spirals.
Orthaulax bed of Florida, etc.

430. T. gatunensis Conrad. (Fig. 1067.) Oligocenic.
Whorls convex, but convexity marred by three strong spirals.
Vicksburgian, and Orthaulax beds of Florida. Isthmus of

Darien, Panama, Costa Rica, etc. P

GASTROPODA—TURRITELLIDZ. 733

ra ik
SC
at

Fic. 1065. 7Zurritella Fic. 1066. TZurritella Fic. 1067. TZurritella
humerosa, X %. (Md. tampa. gatunensis,
Survey. )

431. T. indenta Conrad. (Fig. 1068, 4, c.)
Oligocenic and Miocenic.
With very deep sutures in older whorls owing to abrupt lower
and upper angulations of whorls, and slight, loose coiling ; young
whorls in contact. Sides concave, faintly spiraled.
Chipolan beds of Chipola River, Florida, and Chesapeake beds
of Maryland.

432. T. equistriata Conrad. (Fig. 1068, a.) Miocenic.
Small, whorls embracing nearly up to the angulation, above
which they are almost flat, except for a second faint angulation or
strong spiral some distance below the suture, and very fine spirals.
Aperture longer than wide.
Shiloh marls of New Jersey, Chesapeakean (Calvert) of
Maryland.

~~

734 NORTH AMERICAN INDEX FOSSILS.

433. T. plebeia Say. (Fig. 1068, ad) Miocenic.
Whorls convex, suture depressed ; spirals numerous. A variety

has the whorls flattened (Fig. 1068, ¢). Another variety, octo-

naria, has one strong spiral, the others variable (Fig. 1868, /).
Chesapeake formation of New Jersey, Maryland, Virginia. :

Fic. 1068. a, 7urritella equistriata; b, c, T. indenta; d—f, T. plebeia, (After
Martin, Md. Survey. )

434. T. variabilis Conrad. (Fig. 1069, a.) Miocenic.
Very long and slender, sutures scarcely impressed, four primary

spirals thick, rounded, in pairs, separated by secondary finer ones.
Chesapeake formation of Maryland, Virginia, etc.

”

435. T. cumberlandia Conrad. (Figs. 1069, 4, and 1070.) b

Miocenic. i

With two, rarely three, strong spirals and numerous finer ones. 4

Suture closed or depressed. }
Chesapeake of New Jersey, Maryland, etc. °

GASTROPODA—TURRITELLIDEZ. 735

436. T. exaltata Conrad. (Fig. 1069, c.) Miocenic.
Slender like the preceding, with strongly carinate angle over-

hanging ; shoulder concave with faint spirals, one near suture.
Chesapeake (Calvert) formation of Maryland, etc.

Fic. 1069. a, Turritella variabilis; 6, 7. cumberlandia; c, T. exaltata. (After
| Martin, Md. Surv.)

437. T. subannulata Heilprin. (Fig. 1071, c.)
Oligocenic—Pliocenic.

Main angulation at the center of whorl pronounced, whorls flat
and sloping above, vertical below to the second carina, after which
the whorl rounds downward; whorls embracing nearly to the
second carina; a strong spiral above suture. |

Abundant in Caloosahatchie marls of Florida, and the Wacca-
maw beds of Carolina. Also in the Chipolan beds (Oligocenic) of
Florida.

438. T. perattenuata Heilprin. (Fig. 1071, a.) Pliocenic.
Very long and slender, whorls deeply concave in the middle, a

736 NORTE AMERICAN INDEX POSSILS:

Fic. 1070, TZurritella cumber- Fic. 1071. a, Turritella perattenuata,
landia. (Md. Survey.) X44; 4, TZ. apicalis, Xx 1.8; 6.7
nulata XK 2).

strong rounded, commonly cancellated, spiral above the basal
angulation, and a stronger double or triple one at a similar dis-»

GASTROPODA—TURRITELLIDE. VA

tance below the suture, which is broadly depressed. One or two
faint spirals in concave space of adult whorls.
Caloosahatchie beds of Florida.
439. T. apicalis Heilprin. (Fig. 1071, 0.) Pliocenic.
Shorter and more rapidly tapering than the preceding, with a
similar cancellated median spiral ; upper carina single.
Caloosahatchie beds of Florida.

CXXII. Vermetus Adams.

Young shell like Zurritella, adult portion loose and variously
twisted ; the young shell gradually disappearing and the aperture
becoming round. (The species are mostly terminals of various
genetic lines of Zurritella.) Eocenic—Recent.

440. V. (Petaloconchus) varians d’Orbigny.
Oligocenic—Recent.

Irregularly convoluted, forming a loosely glomerated mass with
longitudinal rugose ridges or costz, or smooth. On the inside of
tube, two scarcely curved lamellze extend obliquely inward from

Fic. 1072. a, Vermetus graniferus; 6, part of same enlarged; c, V. virginicus.
(After Martin, Md. Survey. )

the ends of the more flattened side, with often a short one arising
between them.

Oligocenic of Florida. Pliocenic of Carolina (Waccamaw beds)
and Florida (Caloosahatchie beds). Post Pliocenic, Florida reefs ;
living southwest Florida to Rio Janeiro.

441. V. graniferus (Say). (Fig. 1072, a, 0.) Miocenic.

Turritelloid portion short, non-coiling portion very much con-
torted and vermetoid, in complex clusters; surface with longi-
tudinal, granulose striz ; size varying according to age.

Chesapeake formation of Maryland, New Jersey, etc.

738 NORTH AMERICAN INDEX FCSSILS.

442. V. virginicus (Conrad). (Fig. 1072, c.) Miocenic.
Differs from the preceding in being less intricately coiled, and
in the absence of surface sculpture, except lines and wrinkles of
growth.
Chesapeake formation of Maryland, Virginia, etc.

CXXIII. Laxispira Gabb.
Vermetoid shells of subregular, loose coils, forming a corkscrew
spire. Cretacic—Tertiary.
443. L. lumbricalis Gabb. (Fig. 1073, a.) Cretacic.

Fic. 1073. a, Laxispira lumbricalis (left) ; 6, Siliquaria pauperata (right). (After
Whitfield. ) |

Loose-coiled spirals, the section of shell nearly circular except
in last volution ; surface with fine spirals and lines of growth.
Ripleyan of New Jersey and southern states.

CXXIV. Siriquaria Bruguiere.
Like the preceding but with a continuous cleft or row of pores
along one side of the entire shell. Cretacic-Recent. .
444. S. pauperata Whitfield. (Fig. 1073, 0.) Cretacic.
Coil loose, surface apparently smooth, cleft on upper side of
whorls.
Ripleyan of New Jersey.

| CXXV. Grauconia Giebel.
Turritelloid shells with faintly canaliculated aperture, the outer
lip of which has an anterior and a median notch or emargination.
Comanchic—Cretacic.

445. G. (Vicarya) branneri (Hill). (Fig. 1074.) Cretacic..

GASTROPODA—MELANIIDEZ. 739

Whorls close, sides flat or concave, the later whorls with a row
of strong nodes on each side next to the sutures.
Glen Rose beds of Texas.

446. G. coalvillensis (Meek). (Fig. 1075.) Cretacic.

Fic. 1074. Glauconia branneri. Fic. 1075. Glauconia coalvillensts,
{After Hill. ) x %. (After Stanton. )

Often large ; whorls strongly angular, embracing so as to leave
a rather pronounced space exposed below the carina ; shoulder
with a submedian strong spiral, body with two fainter ones below
the carina.

Colorado of Utah.

Family MeLanupa& Lam.
CXXVI. HypstpLEurA Koken:

Turreted shells with entire oval aperture, scarcely impressed
sutures, and gently convex whorls. Surface ribbed.

447. H.? occidentalis Stanton. (Fig. 1076, a.) Comanchic.
Small, with strong curved ribs, separated by more than their
width ; fine revolving spirals, especially visible between the ribs.
Abundant in beds near the top of the Knoxville near Paskenta,
California.

448. H. gregaria Stanton, (Fig. 1076, 6.) Comanchic.
Smaller than the preceding and with the ribs only partly devel-
oped below the suture. Spirals absent.

740 NORTH AMERICAN INDEX FOSSILS.

Upper part of Knoxville near Paskenta, California.

CXXVII. Merania Lamarck. (Compare Goniobasis.)

Turreted shells with surface varying from smooth to spirally
striate, ribbed or with sharp nodes upon the angulation of the
whorls. Aperture oval, rounded anteriorly. Operculum horny,
apex usually dehiscent. Form less slender and whorls more
strongly individualized than in Zurritella. Jurassic—Recent.

449. M. insculpta Meek. (Fig. 1076, c.) Cretacic.

Fic. 1076, a, Hypsipleura occidentalis, enlarged; 6, H. gregaria; c, Melanta in-
sculpta,; d, e, M. wyomingensis; f, M. sculptilis; g, M. taylori; h, t, Melanopstis
americana. (a, 6, after Stanton, the others after White, U. S. G. S., III.)

-

Sutures scarcely impressed, ribs continuous on the flattened
whorls, thick, round and separated by impressed lines only.
Laramie of Wyoming. |
450. M. (Pachychilus) wyomingensis. (Fig. 1076, d, ¢.)
Cretacic.
Young like the adult of the preceding species ; later whorls ab- -
ruptly angulated, with concave shoulders, and the ribs replaced
by spinose nodes on the angulation. Spirals simple, not strong.
Laramie of Wyoming and Colorado. :
451. M. sculptilis Meek. (Fig. 1076, /) Miocenic.
Short, with comparatively few whorls. Sutures with a false

GASTROPODA—MELANIIDEZ. 741

shelf due to prominence of spiral. Five strong spirals, of which
the upper three appear on all whorls. Faint vertical sculpture
between these. Aperture ovoid.

Fresh-water Miocenic of Idado, Nevada.

452. M. taylori Gabb. (Fig. 1076, g.) Miocenic.
High-spired with three strong spires visible on all whorls, suture
impressed, vertical sculpture moderate between spirals ; aperture
oval.
Fresh-water Miocenic of Idaho.

CXXVIII. Metanopsis Lamarck.

Shell generally shorter and thicker than Me/ania, with aperture
bearing strong basal notch and with inner lip callous. Surface
smooth or ornamented as in Welania. Cretacic—Recent.

453. M. americana White. (Fig. 1076, 4, z.) Cretacic.

Small, sutures not impressed, whorls flattened, shell gently
tapering from middle of body whorl ; canal short, slightly reflexed ;
surface smooth.

Laramie of Colorado.

CXXIX. PyrRGULIFERA Meek.

Thick, elongate, oval shells, whorls with narrow shoulder
bounded by strong angulation on which the ribs are produced as

Fic. 1077. Pyrgulifera humerosa, opposite views of two specimens showing varia-

tion. (U.S. G. S.)

spinose tubercles; spirals numerous but subdued, aperture oval,

sometimes with very faint canal. Cretacic.

454. P. humerosa Meek. (Fig. 1077, a—d.) Cretacic.
Shoulder concave, tubercles strong, blunt, and produced down-

742 NORTH AMERICAN INDEX-FOSSILS.

wards as ribs which die away on lower body whorl; spirals broad

but generally faint ; a faint indication of anterior notch in aperture.
Bear River formation of Wyoming and Utah.

CXXX. Gonrosasis Lea.

Shell characters like those of JZe/ania from which these shells.
are practically indistinguishable. This genus is the American rep-
resentative of the Old World genus Melania which is doubtfully
represented in the American Eocenic. The chief differences are
that Melanza is viviparous and Goniobasis is oviparous. Both are
fluviatile animals.

455. G. (Pachymelania) chrysallis Meek. (Fig. 1078, a.)
Cretacic.
Whorls flattened to slightly concave, sutures not impressed but
margined below by blunt carina which is often crenulated. Sur-
face with spirals.
Bear River formation of Wyoming and Utah.

456. G. (Pachymelania) chrysalloidea White. (Fig. 1078, 3.)
Cretacic.
Short and thick, whorls flat, sutures with faint shelf, surface
with rounded ribs and few faint spirals.
Bear River formation of Wyoming and Utah.

457. G. (Pachymelania) cleburni White. (Fig. 1078, c.)
Cretacic.
Large, gently tapering, sutures faintly impressed, surface with
low rounded ribs, gently concave forward, extending from suture
to suture, and generally separated by wider interspaces ; no spirals.
Bear River formation of Wyoming and Utah.
458. G. convexa M. and H. (Fig. 1078, d@.) Cretacic.
Smooth, slender, suture not impressed, surfaces flat, spirals faint.
Variety zupressa has the sutures slightly impressed.
Laramie, mouth of Judith River, Montana.
459. G. endlichi White. (Fig. 1078, e,/) Cretacic.
Short and thick, whorls round and smooth and sutures strongly
impressed.
Bear River formations of Wyoming and Utah.
460. G. gracilenta Meek. (Fig. 1078, g.) Cretacic.
Small, smooth, sutures slightly impressed, surfaces gently con-
vex ; faint vertical striz.

GASTROPODA—MELANIIDE. 743

Laramie of Colorado, Wyoming.
461. G. invenusta M. and H. (Fig. 1078, Z.)
Smooth, with somewhat larger apical angle than preceding.
Laramie of Montana (upper Missouri River region).
462. G. macilenta White. (Fig. 1078, z.) Cretacic.
Whorls flattened, sutures not impressed, marked by faintest of
shelves, surface smooth.
Bear River formation of Wyoming and Utah.

463. G. nebrascensis M. and H. (Fig. 1078, 7.) Cretacic.

Fic. 1078. a, Goniobasis chrysallis ; b, G. chrysalloides; c, G. cleburni,; d, G.
convexa ; ¢, f, G.endlichi; g, GC. gracilenta; h, G.invenusta,; 1%, G. macilenia; 7,
G. nebrascensis ; kh, G. sublevis ; 1,m,-G.subtortuosa; n, 0, G. tenuicarinata; p, G.
simpsoni; g, G. ltenera; r-t, G. nodulifera; u, v, G. carteri; w, G. columinis.
Omar Whitf., U.S. G. S., III.)

Smooth, broad, thick, sutures slightly impressed, surfaces gently
convex ; lines of growth the only surface marking.

Laramie of Yellowstone River region ; Canada, upper Missouri
River region ; Colorado and Utah.

744 NORTH AMERICAN INDEX FOSSILS.

464. G. sublevis M. and H. (Fig. 1078, 4.) Cretacic,

Larger and somewhat more slender than G. gracilenta and suture
slightly impressed.

Laramie (Judith River) of Upper Missouri River region.

465. G. subtortuosa M. and H. (Fig. 1078, /, m.) Cretacic.

Small, low-spired, strongly angulated near the middle, shoulder
nearly flat; no ribs or spirals.

Laramie of Upper Missouri River region and the Bow and Belly
River regions of Canada.

466. G. tenuicarinata M. and H. (Fig. 1078, 7,0.) — Cretacic.

Angulated, short and thick-set, shoulder flat, limited by sharp
carina, below which are two or three sharp spirals.

Laramie of Montana, the Upper Missouri River region, Col-
orado, east of Rockies, Utah and various localities in Canada. _
467. G. simpsoni Meek. (Fig. 1078, 7.) Eocenic.

Smooth, whorls convex, suture impressed.

Bridger Eocenic, Wyoming.

468. G. tenera Hall. (Fig. 1078, @.) Eocenic.

Like the preceding but with faint ribs extending part way below
the suture, and with faint spirals.

Eocenic, Utah. ©
469. G. nodulifera Meek. (Fig. 1078, 7-7.) Eocenic.

Ribs mostly replaced by faint nodulations on the median angu-
lation. Shoulder flat.

Fresh-water Eocenic of Rocky Mountain region.

470. G. carteri Conrad. (Fig. 1078, w, v.) Eocenic.
_Nodules strong, ribs not altogether obsolete.

Fresh-water Eocenic of Rocky Mountain region.

471. G. columinis White. (Fig. 1078, w.) Eocenic.

Strongly angular, nodes large and sharp and continued in ribs
nearly to sutures; spirals strong.

Fresh-water Eocenic of Rocky Mountain region.

Family NERINEID# Zittel.
CXXXI. Nerinea Defrance.
Like Zurritella in-form, but aperture with short anterior notch,
columella with simple folds which are also commonly found on
both inner and outer lip. Jurassic—Cretacic.

i}

GASTROPODA—NERINEIDZ. 745

472. N. goodelli Cragin. (Fig. 1079, a, 0.) Jurassic.

Sides of whorls concave, strongly carinated at base, with three
to four rather marked spirals; outer wall with one prominent,
thin, acute fold internally, extending scarcely half way across the
chamber (well seen in longitudinal sections). Columella partly

Fic. 1079. a, 6, Nerinea goodelli; c-e, Nerinella stantoni, with enlargement and
section. (After Cragin, Bull. U. S. G. S., 266.)

hollow and with a smaller fold, while a third one occurs near the
middle of the upper side of the chamber.

Malone formation of Texas ; a related, if not identical form ap-
pears in the Upper Jurassic (Sequanien ?) of the Mazapil region of
Mexico.

473. N. austinensis Roemer. (Fig. 1080, a.) Comanchic.

Large, apical angle about 20°, whorls gently concave, smooth,
basal angulation nodose. Columella with two or three sharp folds,
the middle one, if present, smallest, outer lip with one sharp fold
directed downwards.

Edwards limestone of Texas.

474. N. cultrispira Roemer. (Fig. 1080, 0.) Comanchic.
Much more slender than preceding; whorls smooth, strongly

concave ; basal carina a sharp, blade-like keel. Columella witha

single fold and outer lip with a faint one, obsolete in the adult shell.
Edwards limestone of Texas.

746 NORTH AMERICAN INDEX FOSSILS.

CXXXII. NERINELLA Sharpe.

Like erinea but with columellar fold generally wanting ; a fold
commonly occurs on the inside of the outer lip. Jurassic—
Comanchic.

475. N. stantoni Craigin. (Fig. 1079, c-e.) Jurassic.

Fic. 1080. a, WMerinea austinensis; b, N. cultri- Fic. 1081. erinella
spira, (After Roemer. ) subula. (After Roemer. )

Exceedingly slender ; whorls with gently concave sides bearing
four equidistant spirals; upper and lower angulations sharp and
appearing as spirals. No columellar fold but a blunt one on inner
side of outer lip.

Malone formation of Texas.

476. N. subula (Roemer). (Fig. 1081.) Comanchic.

Slender and subulate; suture scarcely depressed; sides of
whorls flat with two (more rarely three) rows of small tubercles on
the basal portion of the body whorl; aperture elongate. No

columellar or labial folds. 7

r

ee

.
2 eS er

GASTROPODA

CERITHIDA. 747

Family CrerirHipa Menke.
CXXXIII. Birrrum Leach.

Turreted shells with spirals and costz which generally cancel-
Jate each other. Aperture with short, straight canal and sharp
outer lip. Jurassic—Recent.

477. B. permutabile Dall. (Fig. 1082, c.) Oligocenic.

Greatest convexity of the whorls below the middle of the ex-
posed part; costz strong but becoming obsolescent towards the
suture ; spiral fine, often compound. Aperture with feeble canal.

Chipolan marls of Florida.

478. B. cossmannii Dall. (Fig. 1082, 0.) Oligocenic.,

Fic. 1082. a, Bittium (Styliferina) boiplex, X 7.53 6, Bittium cossmannit, K 334 ;
c, B. permutabile, ~ 4.6.

Shorter and stouter than preceding, rather inflated, with ribs
mostly obsolete on adult whorls except here and there a strong
varix-like one.

Chipolan marls of Florida.

479. B. (Styliferina) boiplex Dall. (Fig. 1082, a.) Oligocenic.
Long, slender, round-whorled ; three strong spirals cancellating
the ribs ; occasionally strong varix-like ribs; simple spirals on
body of last whorl, and sometimes above suture. Aperture with-
out canal.
Chipolan marls of Florida.

748 NORTH AMERICAN INDEX FOSSILS.

480. B. (Styliferina) cerithidioides Dall. (Fig. 1083.)
Oligocenic—Recent.
Upper whorls angular; later rounded, with only close-set
rounded ribs ; aperture with very faint anterior notch.
Bowden beds of Jamaica, W. I., Caloosahatchie (Pliocenic) ;
Florida and Costa Rica; Post-Pliocenic, South Carolina ; living off
the southeastern coast of the United States.

CXXXIV. CERITHIUM Bruguiere.

Turreted, non-umbilicate, variously sculptured, and with the
aperture bearing a short, backwardly-curved canal, and frequently
a notch or short canal, on upper or posterior side of aperture.
Columella concave, often with one or two folds. Numerous sub-
genera. Jurassic—Recent.

481. C. bosquense Shumard. Comanchic.
Large; apical angle 22~-25°; whorls flattened with 11-12
broad rounded ribs on each; moderately distinct above, but be-

Fic. 1083. Aittium (Styliferina) ceritht Fic. 1084. a, Cerithium obliterato-
dioides Dall, &X 13. (After Dall. ) granosum, 6, C. austinense. (After
Roemer. )

coming obsolete towards lower suture ; aperture ovate, oblique,
widest below the middle.
Walnut shale and Comanche Peak and Goodland limestones of
cexas.
482. C, (Fibula) obliterato-granosum Roemer. (Fig. 1084, 2.)
Comanchic.
Round-whorled with somewhat depressed sutures and oblique
ovate aperture with faint anterior canal (not always preserved) and,

GASTROPODA—CERITHIIDZ. 749

a reflexed inner lip. Sculpture in the form of vertical rows of
fine nodules.

_ Edwards limestone of Texas.

483. C.(?) austinensis Roemer. (Fig. 1084, 6.) | Comanchic.

Round-whorled with pronounced round ribs and 6-8 strong
spirals, continuous across the ribs, and frequently with intercalated
finer ones. Aperture with short, curved canal.

Edwards limestone of Texas.

484. C. (Newtoniella) conicum Aldrich. Eocenic.

Small and slender, sutures depressed ; sides of whorls nearly
flat with uniform distant ribs, crossed and somewhat
rounded by three strong spirals ; a fourth, nearly cov-
ered at the suture by the succeeding whorl, gives the
characteristic appearance to the shell.

Claibornian of Alabama.

485. C. (Cerithiopsis) fluviatile Aldrich. Eocenic. :
Differs from the preceding in the absence of the wg
spiral at the suture and the freedom from nodes of the he

- first spiral above the suture. Fic, 1085.

Chickasawan (Lignitic) of Alabama. Cerithium ( Se-

486. C. (Seila) adamsii H.C. Lea. (Fig. 1085.) oN pariae
Oligocenic to Recent. —

Small (length 7 mm.), slender, whorls flat, suture not impressed,
about four equal spirals with equal interspaces, strong anterior
and fainter posterior notch in aperture.

Chipolan beds of Florida, Miocenic of Virginia and North Caro-
lina, Croatan beds (Pliocenic) of North Carolina ; Waccamaw beds
of South Carolina, Caloosahatchie of Florida, Post-Pliocenic of
Atlantic and Gulf States ; living on South Atlantic coast of U. S.

487. C. (Potamides [Tympanotonus]) hillsboroense Heilprin.
(Fig. 1086.) Oligocenic.
Suture loose; whorls flat or slightly concave ; upper spiral

strongly nodose; next below, thin and finely granulose ; third,

coarser and nodose and the fourth, just above the suture, smooth.
Orbitoides limestone of Florida.

488. C. (Rhinoclavis) caloosaensis Dall. (Fig. 1087.) Pliocenic.
Ornamentation of whorls complex, consisting of coarse and fine
spirals, some traversed by ribs, others noded. The body whorl is

750. NORTH AMERICAN INDEX FOSSILS.

non-angulate, the preceding two or three are angulate ; while the
earlier ones are more or less flat and ribbed. Lip drawn out at
each end to form a narrow, deep canal.

Caloosahatchie beds of Florida.

489. C. (Potamides)scalatum Heilprin. (Fig. 1088.) Pliocenic.

Fic. 1086. a, Cerithitum Fic. 1087. 6, Cerithium Fic. 1088, c, Potamides
Aillsboroénse, X 1.3. (After caloosaénse, X 24. (After (Pyrazisinus) scalatus, x 2.
Dall. ) Dall. ) (After Dall. )

Whorls round, slightly concave below the suture, ribs simple,
not reaching to upper suture ; faint spirals between ribs ; outer lip
broadly notched. :

Caloosahatchie beds of Florida, etc.

Family APporRHAIDA Philippi.
CXXXV. ANcHuURA Conrad.

Turreted shells with the base drawn out into a long canal,
and the outer lip prolonged into a single wing-like expansion
which may divide terminally, but is often broken away in the
specimens. Comanchic—Cretacic.

490. A. kiowana Cragin. Comanchic.
Differs from the next in its somewhat shorter spire, more pro-

nounced costz, roundness of body whorl, and restriction of carina

nearly to falcate process of lip, which is only slightly upturned.
Kiowa shales (Washita) of Kansas.

491. A. exilis Gabb. (Fig. 1089.) Cretacic.
Small, whorls rounded except for strong median carina of body .
whorl, above which shoulder is concave ; ribs low and faint.

GASTROPODA—APORRHAIDZ. 751

Nanaimo formation of Vancouver and Martinez.

492. A. rostrata Gabb. (Fig. 1090.) Cretacic.
Apical angle about 35°; early whorls round with slightly im-
pressed suture and obliquely forward-curving, round and close-set
ribs; body whorl with ribs more distant and becoming obsolete ;
lip broadly expanded, upper angle somewhat produced.
Ripleyan formation of New Jersey, Mississippi, Texas.

Fic. 1089. Anchura exilis, enlarged. Fic. 1090. <Axnchura rostrata.
(After Gabb. ) (After Whitfield. )
493. A. pennata (Morton). (Fig. 1091.) Cretacic.

Larger and with sharper and more distant ribs on the younger
whorls, obsolete on body whorl ; lip with two upper corners more

Fic, 1091. Anchura pennata. (After Fic. 1092. Anchura abrupta.
Whitfield. ) (After Whitfield. )

strongly prolonged upwards. Internal molds with deep sutures.
Ripleyan of New Jersey and Alabama.
494. A. abrupta Conrad. (Fig. 1092!) Cretacic.
~Whorls more rounded than preceding; ribs like those of A.
rostrata, but fainter ; a faint spiral sculpture, becoming an angula-
tion on body whorl and lip.

762 NORTH AMERICAN INDEX FOSSILS. 2

Ripleyan of New Jersey, Alabama, Mississippi. :
495. A. sublevis (M. and H.). (Fig. 1093.) Cretacic.
Much smaller than preceding ; high-spired with round whorls

FIG. 1093. Anchura sublevis, type of species. With apertural expansion wanting.
(After Meek. )

marked by faint spirals only.
Pierre of Yellowstone and Black Hills.

CXXXVI. CALYPTRAPHORUS Conrad.

ff

Differs from Axchura\in® having the entire shell more or less
covered by the expansion of the lips; this hides the character of
the whorls. Tertiary—Recent.

496. C. velatus Conrad. (Fig. 1094.) | Eocenic.

Fic. 1094. Calyptraphorus velatus var. compressus. (After Harris. )

Expanded but rounded lip, the enamel covering most of the
whorls, leaving only the upper part of the spire exposed ; rostrum
long and pointed. In the variety compressus Aldrich, large gaps
remain in the enamel covering the upper edge of the lip which is
much prolonged and pointed.

GASTROPODA—APORRHAIDE. 753

Claibornian and Jacksonian of the Gulf States; the variety
occurs in the Midway horizon of the Gulf States from Georgia to
Texas.

497. C. trinodiferus Conrad. (Fig. 1095, a, 0.) Eocenic.

Fic. 1095. a, 5b, Calyptraphorus trinodiferus,; c, d, C. jacksoni. (All & %.)
(Md. Survey. )

With ornamentation of early whorls faint, and with great pro-
longation of the reflected upper angle of the lip.

Pamunkey formation of Atlantic coast. Lignitic (Chickasawan)
of Alabama and Texas.

498. C. jacksoni Clark. (Fig. 1095, ¢, d.) Eocenic.
Large, solid, whorl wholly covered by subsequent expansions.
Aquia of Atlantic coast.

e

CXXXVII. AporrRHAIS da Costa.

Like Anchura but lip with posterior canal either closely adher-
ing to the spire, or free from same; outer lip expanded, lobed or
digitate. Jurassic—Recent.

499. A. (Perissoptera) prolabiata White. (Fig. 1096, a.)
Cretacic.
Spire with rounded whorls marked by rounded ribs more than
their width apart; lip with strong, acute spine, separated by a
rounded sinus from the broader subquadrate portion of the lip ;
expansion of lip partly covering penultimate whorl.
Colorado formation of Utah and New Mexico (?).

754 NORTH AMERICAN INDEX FOSSILS.

500. A. (Lispodesthes) nuptialis White. (Fig. 1096,b,c.) Cretacic.
Body whorl with angulation that extends into the spinose pos-
terior prolongation of the lip; anterior canal straight and rapidly

Fic. 1096. a, Aporrhats (Perissopltera) prolabiata; b, c, A. (Lispodesthes) nupti-
alis. (After Stanton. )

tapering; surface of whorls generally completely enveloped in
callous deposits.
Colorado formation of New Mexico, Arizona, etc.

sor. A. (Tessarolax) distorta Gabb. (Fig. 1097.) Cretacic.

Spire concealed by smooth surface deposits; body whorl with
two carinations, each of which bears an irregular blunt node, the
lower one formed after the upper one, and each extending into

Fic. 1097. Aforrhais ( Tessarolax) distorta, slightly reduced. (After Gabb. )

a canaliculate spine; anterior and posterior ends of aperture
drawn out into similar curved canaliculate spines.
Nanaimo of Vancouver, B. C., and Chico of California.

GASTROPODA—STROMBIDEA. 755

502. A. (Pterocerella) tippana Conrad. (Fig. 1098.) Cretacic.
Spire angulated, with keel and flattened shoulder; lip with six

finger-like processes somewhat winged by marginal expansions.
Ripleyan of New Jersey, Mississippi, Texas.

503. A. falciformis Gabb. (Fig. 1099.) Cretacic.

Fic. 1098. Aporrhais (Pterocerella) tippana. Fic. 1099. Aporrhais falciformis,
(After Weller. ) slightly reduced. (After Gabb. )

High, slender spire, round whorls, scarcely impressed sutures,
narrow rounded and distant ribs gently concave forward, and
cancellated by simple spirals. Body whorl nearly smooth; aper-
ture with long, falciform expansion.

Upper Cretacic of California.

Family StromBipz d’Orbigny.
CXXXVIII. PuGNnetius Conrad.

Young shell fusiform; adult suboval; inner lip massive, extend-
ing as a callus over the whorls; outer lip variously lobed. Cretacic.
504. P. fusiformis Meek. (Fig. 1100.) Cretacic.

Spire somewhat curved; body whorl somewhat nodose; outer
lip with falciform extension and several pronounced lobes.

Coloradoan (especially Pugnellus sandstone) of Colorado, Utah,
Wyoming.

756 NORTH AMERICAN INDEX FOSSILS.

Fic. 1100, Pugnellus fusiformis. (After Stanton. )

CXXXIX. OrTHAULAx Gabb.
Spire of smooth whorls, lip simple, extending at each end into
a canal; spire mostly enclosed by a deposit of enamel. Eocenic-
Miocenic.
505. O. gabbi Dall. (Fig. 1101.) Oligocenic—Miocenic.

Young showing many whorls, lip expanding posteriorly and
covering spire; later whorls each with three irregular varices;

Fic. t101, Orthaulax gabbi, about three fourths Fic. 1102. Rimedla laqueata.
nat. size. (After Dall.) (After Conrad. ) .

columellar pillar thick, slightly recurved, canal short, the outer
lip somewhat thickened.
Chipolan and Alum Bluff beds of Gulf States.

GASTROPODA—STROMBIDE. 757

CXL. RIMELLA Agassiz.

More or less high-spired shells; base drawn out into short sharp
canal; inner lip with expansion covering part of spire, outer lip
with thick but scarcely expanded margin, entire or crenulated and
with anterior notch. Cretacic—Recent.

506. R. laqueata Conrad. (Fig. 1102.) Eocenic.

High spired; sutures scarcely impressed; ribs acute, slightly

curved, restricted to upper part of whorl; spirals fine; outer lip
smooth.

Claibornian of Alabama.

CXLI. Strromsus Linné.

Young shell more or less fusiform with conical spire variously
ornamented by ribs, spires and tubercles; adult with large body
whorl, and thick, expanded but not spinose outer lip, often pro-

‘>

Fic. 1103. Strombus aldrichi, slightly reduced, <$. (After Dall. )

duced posteriorly, sinuate or channelled anteriorly ; columellar area
smooth, enameled. Cretacic—Recent.

507. S. aldrichi Dall. (Fig. 1103.) Oligocenic.

Youngest whorls round and ribbed, later ones angular, the
ribs becoming concentrated as tubercles on the angle, and coarse
on body whorl; lip moderately expanded, subrectangular above

(posteriorly) with slight posterior, and strong broad anterior
(lower) channel.

Abundant in the Chipolan beds of Florida.

758 NORTH AMERICAN INDEX FOSSILS.

508. S. chipolanus Dall. (Fig. 1104.) Oligocenic.
Differs from the preceding in its larger size, stronger and
sharper shoulder nodules, more slender spire and less thickened

.\ \

Fic. 1104. Strombus chipolanus, about three fourths nat. size. (After Dall.)

outer lip, with stronger posterior and larger anterior notch, and
less elevation posteriorly. Body and throat lirate.
Occurs with the preceding.
509. S. pugilis Linné. 7 Miocenic—Recent.
Larger than the preceding; spire low, strongly spinose; body
whorl tapering, outer lip not strongly expanded, with deep antero-
lateral, and strong anterior notch. Callus of inner lip extensive.
Miocenic of Haiti, Jamaica, and Costa Rica; Pliocenic of Costa

Rica and Florida; Pleistocenic and Recent from the Carolinas to
Florida and the West Indies.

Family CypR#ID@ Gray.

CXLII. Cypraa Linné.

Spires of adult wholly covered by expanded outer lip, which
curves inward, leaving a narrow, elongate aperture, both sides of
which are strongly lirate; entire surface smooth and _ polished.
Jurassic—Recent.

510. C. mortoni Gabb. Cretacic.
Small, ovate; margins of aperture finely crenulated.
Ripleyan (generally internal mold) of New Jersey and Alabama.

GASTROPODA—CY PRAIIDA:—CASSIDID.. 759

511. C. pinguis Conrad. (Fig. 1105.) Eocenic—Miocenic.
Ventricose near the middle; outer lip strongly curved at the
spire; crenulation thick; basal callus rather marked.

FIG. 1105. Cyprea pinguts, profile and apertural views, 1.4. (After Dall. )

Eocenic of Louisiana, Oligocenic and Miocenic of Florida and
North Carolina.
CXLIII. Erato Risso.

Small shells with some of the characteristics of the young
Cyprea; the spire only partly covered; columellar surface partly
denticulate; outer lip strongly so. Cretacic—Recent.

512. E. perexigua (Conrad). (Fig. 1107, a.) Miocenic.

Spire with a few smooth whorls embracing to above ambitus;
outer lip thick, with numerous strong denticulations; those of
columella small, few and scattered.

Chesapeakean of Maryland and Shiloh marls of New Jersey.

Family Cassipip# Adams.
CXLIV. Cassmarta Lamarck.

Shells with short, conical or turbinate spires ;

large body whorl drawn out anteriorly into a

. twisted canal which is bent sideways or back-

ward; expanded inner and reflected outer lip,

often crenulated, the columellar border plicate.
Cretacic—Recent.

513. C. brevidentata Aldrich. (Fig. 1106.)

ie Eocenic. Pt aN aS
. 7 aria reviaenilaia.
Whorls embracing to just below the shoulder (After Harris. )

Fic. 1106. Cassze

760 NORTH AMERICAN INDEX FOSSILS.

angle, which is regularly nodulated. Two strong non-nodose

spirals produce a marked biangulation of the body whorl; inner

lip with three plications in the (posterior) upper part.
Chickasawan (Lignitic) of Alabama.

Family DoLtiip# Adams.
CXLV. Pyruita Lamarck.

Thin, low-spired shells with strongly embracing whorls, drawn
cut anteriorly into a canal; aperture indented with sharp outer
lip; surface spirally sculptured. Comanchic—Recent.

514. P. (Ficus) penita Conrad. (Fig. 1108.) Eocenic.
Spire conical; sutures scarcely impressed; body whorl round
except for three faint carinze; surface cancellated by spirals and
vertical striz; lip thickened towards the margin.
Claibornian of Alabama, Nanjemoy of Maryland.

515. P. mississippiensis Conrad. Oligocenic.
Thin, pyriform, with short spire and convex whorls; the body

whorl flattened on top; surface latticed by large distant spirals and

finer ones between, and closely arranged, vertical lines.
Vicksburgian of Mississippi.

516. P. harrisi Martin. (Fig. 1107, 0.) Miocenic.

Fic. 1107. a, Erato perexigua; b, Pyrula harrist ; c, Columbella communis.
(After Martin, Md. Mioc. )

Inflated with rather short canal, large aperture, and short spire;
surface sculptured by fine spiral lines.
Chesapeake Miocene of Maryland.

GASTROPODA—COLUMBELLIDA—BUCCINIDA. 761

Family COLUMBELLID& Troschel.
CXLVI. CoLuMBELLA Lamarck.

Small, ovate or fusiform shells, with narrow aperture, lirate or
denticulate outer lip. Tertiary—Recent.

517. C. (Astyris) communis (Conrad). (Fig.1107,c.) Miocenic.
Rather high spire, smooth or with spirals visible only under

lens, except on spindle. Outer lip strongly denticulate within.
Chesapeakean of Maryland and New Jersey.

Family Bucctnip# Troschel.
CXLVII. Buccinum Linn.

Stout inflated shells, smooth or ribbed and spiraled; spire short,

Fic. 1108. yrula penita, K %. Fic. 1109. SBuccinofusus parilis, K %.
(After Conrad. ) (Md. Survey.)

aperture wide, anterior canal short; outer lip sharp, thin, smooth;
inner lip with callus. Tertiary—Recent.

518. B. mississippiensis Conrad. Oligocenic.
Small, spire rather high, with distant narrow ribs and raised

alternating spirals. Outer lip lirate within; columella striate.
Vicksburgian of Mississippi.

762 NORTH AMERICAN INDEX FOSSILS.

CXLVIII. Bucctnorusus Conrad.

Large and stout fusoid shells with round, rapidly increasing
whorls, short canal scarcely contracted at the anterior end which
is slightly reflected; ribs and spirals coarse, the former becoming
fainter in the adult shell. Differs from Siphonalia chiefly in its
straighter canal, and wider more patulous aperture.

519. B. parilis Conrad. (Fig. 1109.) Miocenic.

Whorls round, contracted rather rapidly to long, slightly re-
flected canal; aperture wide; ribs strong on younger, weaker on
adult whorls; round and broad spirals uniformly strong, with
numerous threadlike intercalated secondary spirals between each
pair of primary. |

Chesapeakean of Atlantic coast.

CXLIX. SrpHonartia Adams.

Short, thick-set fusoid shells with ribs and spirals, or with
spirals only and with short, strongly reflected anterior canal.
Eocenic—Recent.

520. S. devexa (Conrad). (Fig. 1110, a.) - _Miocenic. —

Fic. 1110. a, Siphonalia devexa; 6b, S. migrans, both X 24. (Md. Survey. )

Shoulders concave; angle blunt; ribs concentrated on angle,
dying away in either direction; spirals numerous; frequent inter-
calations ; canal sinuous.

Chesapeakean of Atlantic coast.

521. S. migrans (Conrad). (Fig. 1110, D.) Miocenic.

Last whorls non-angulate, without ribs, with numerous spirals ;
angulation of early whorls less pronounced.

GASTROPODA—BUCCINIDE. 763
Chesapeakean of Maryland.

CL. NeEpTuNEA Bolton.

Fusoid shells with long, slender, many-whorled spire, and rather
short, often bent canal. Eocenic—Recent.
522. N. bella (Conrad). Kocenic.

Small, high spired; whorls round; suture depressed ; canal short,
strongly curved; ribs narrow, round, widely separated; spirals,
fine, regular.

Claibornian of Alabama.

CLI. Nassa Martini.

Differs from Buccinum in its higher spire, shorter aperture
with short, reverted canal, and lirate outer lip. Cretacic—Recent.
523. N. trivittatoides (Whitfield). (Fig. 1112, a.) Miocenic.

Small (half an inch or less in length), with moderately high
spire and faint sutures; whorls with strong ribs, cancellated by

Fic, 1112, a, Nassa trivittatoides, K 5; 6, ¢, Fic. 1113. vassa bidentata,
LV. peralta, X 2. (Md. Survey.) . < 4.3. (After Dall.)

continuous strong spirals; canal very short; outer lip thick; lire
strong; columella with faint plaits.
Chesapeakean of Maryland and Shiloh of New Jersey.
524. N. peralta (Conrad). (Fig. 1112, Db.) Miocenic.
Larger and more elongate than the preceding; the ribs crowded
and smooth; interspaces with fine spirals; a single small spiral
beads the ribs just below the suture.
Chesapeakean of Maryland.
525. N. vibex Say. . Pliocenic—Recent.
Rather small; suture not impressed; whorls almost flat, ribs and
spirals obsolete or very faint; aperture subcicular.

764 NORTH AMERICAN INDEX: FOSSILS.

Caloosahatchie (Pliocenic) of Florida; living off Atlantic coast.
526. N.bidentata Emmons. (Fig.1113.) Miocenic and Pliocenic.

Like N. trivittatoides, but stouter with coarser ribs and pro-
portionally finer spirals; outer lip with two strong teeth (lire)
on inner side.

Miocenic marls of North Carolina and New Jersey (Shiloh).
Caloosahatchie and Shell Creek Pliocenic of Florida, abundant.
527. N. harpuloides Conrad. Miocenic.

Whorls square-sided, spire elevated; spirals on shoulder oblique
to suture; labial callus thick, outer lip thick, somewhat reflected,
and lirate; a subsutural ridge occurs.

Chesapeakean of Virginia, North Carolina.

528. N. scalaspira Conrad. Miocenic.

Shorter and more acute spire than preceding; last whorl inflated ;
spiral sculpture on latest whorl parallel with the suture.

Chesapeakean of Virginia, North Carolina, etc.

Family FuLtgurip&2* Grabau and Shimer.
CLI. Tupreis Bolten:

Shell with papillose protoconch, and rapidly enlarging whorls,
with nearly flat almost horizontal shoulder, and spinose angulation,
the whorls embracing to the angle; a second row of spines often

Fic. 1114. Zudicla marylandica, K 24. (Md. Survey. )

occurs on body of whorl. Anteriorly drawn out into long fusiform
canal; columellar lip plicate near the base; outer lip lirate: Ter-
tiary—Recent. Py

GASTROPODA—FULGURIDZ. 765

529. T. marylandica Clark and Martin. (Fig. 1114.) Eocenic.
Young whorls round, sunken; shoulder of body whorl convex

near suture, concave near the strongly spinose angulation.
Aquia formation of Maryland.

CLIL, > Pyrorsrs. Conrad.

Differs from Tudicla in its non-papillose apex, and the absence
of lire and columellar plication. Cretacic—Eocenic.

530. P. coloradoensis Stanton. (Fig. 1115.) Cretacic.

Rather robust; canal gently curved, umbilicated ; body whorl not
abruptly contracted below, biangulate, the angles with small,
rounded nodes, both covered in early whorls; spirals numerous;

Fic. 1115. Pyrops?s coloradoensis, shell and internal mold, & 24. (After Stanton. )

lip with posterior canal producing a slight channeling of the suture.
Colorado group (Pugnellus sandstone) of Colorado and Utah?

531. P. richardsoni (Tuomey). (Fig. 1116.) Cretacic.

Spire depressed, low, often almost flat (angle about 135°);
shoulder angle strong with irregular flat nodes; lower angulation
fainter, also noded (angulations appear smooth in internal molds) ;
spirals numerous, strong, alternating in size, those between the
angulations more or less crenate. |

Ripleyan of New Jersey, Alabama, Georgia and Mississippi.
532. P. trochiformis (Tuomey). (Fig. 1117.) Cretacic.

Spire depressed, early volutions almost flat ; body whorl gibbous,
without angulations, rather abruptly contracted into the anterior

766 NORTH AMERICAN INDEX FOSSILS.

Fic. 1116. yropsis richardsoni, X 2%. (After Whitfield. )

canal; spirals numerous, alternating, the primary ones noded.

Internal molds with loose sutures and smooth surfaces.
Ripleyan of New Jersey, Alabama and Mississippi.

Fic. 1117. Pyropsis trochiformis, internal mold and fragment showing surface, « 2%.
(After Whitfield. )

533. P. whitfieldi Weller. (Fig. 1118.) Cretacic.
Small; whorls round; later whorls embracing only to ambitus;
flattened below the suture; spirals simple, rather coarse, noded by
ribs of equal size.
Ripleyan of New Jersey and Alabama.

GASTROPODA—FULGURIDZ. 767

534. P. octolirata (Conrad). Cretacic,
Like the preceding but body whorl somewhat more abruptly con-
tracted; without sutural flattening or ribs, though one of the 8
or 9 spirals is slightly noded.
Ripleyan of New Jersey and Mississippi.

CLIEV. . Preenssouax Gabb.

Spire conical and smooth; canal long; last whorl inflated; bian-
gular, and ornamented by ribs and spirals; columella without plaits.
Differs from Pyropsis chiefly in its long spire. Cretacic.

535. P. brevirostris Gabb. (Fig. 1119.) Cretacic.

’

Fic. 1118. Pyropsis whitfeldi. (After Fic. 1119. Perissolax brevirostris,
Whitfield. ) nat. size. (After Gabb. )

Shoulders of whorls flat, spiraled, whorls embracing to shoulder
angle, forming conical spire of nearly 90° apical angle. Last whorl
with two strong angulations, a third towards the end; traversed
by distant, narrow ribs which are nodose on the angles.

Nanaimo group of Vancouver; Chico of California.

CLV. Futcur Montford.

Whorls (except very young) angulate with flat shoulder and
nodose or spinose angulation; rarely round and smooth whorls
generally embracing to shoulder angle; aperture not abruptly
contracted, but canal long. Protoconch oblique, smooth. Eo-
cenic( ?)—Recent.

768 NORTH AMERICAN: INDEX FOSSILS,

536. F. fusiforme Conrad. (Fig. 1120, aandc.) Miocenic.

Whorls embracing to angle which bears small nodes; shoulder
gently concave; aperture moderately contracted.
Chesapeakean of Atlantic coast.

537. F. tuberculatum Conrad. (Fig. 1120, b.) Miocenic.

Fic. 1120, a, ¢, Fulgur fustforme,; d, Ff. tuberculatum. (Md. Survey.)

Later whorls embracing only part way to angle; nodes flat and
wide; spirals numerous; aperture more abruptly contracted.
Chesapeakean of Atlantic coast.

538. F. maximum Conrad. (Fig. 1121, c.)
Miocenic and Pliocenice.
Large; young whorls tubercled, adult whorls smooth, rounded;
shoulder slightly concave.
Chesapeake Miocenic of Virginia. A more slender, elongate
form of same character (F. rapum var., Fig. 1121, a) occurs in the
Caloosahatchie beds of Florida and Duplin beds of North Carolina.

539. F. tritonis Conrad. (Fig. 1121, D.) Miocenice.
Earliest whorls tubercled as in F. tuberculatum, intermediate
smooth as in F. maximum, adult whorls regularly spinose on
shoulder angle.
Chesapeake Miocenic of Atlantic coast. A slender form [F.
rapum Conrad of another genetic series] with these characters
occurs in the Pliocenic of the Carolinas and Florida.

GASTROPODA—FULGURIDZ. 769

540. F. caricum (Gmelin). Pliocenic—Recent.
Large (length up to 223 mm., width up to 120 mm.) with all
the whorls strongly spinose on the shoulder angle, except the
earliest which bear only round nodes.
Pliocenic of the Carolinas; Pleistocenic and living Atlantic coast
from Cape Cod to West Indies.

541. F. contrarium Conrad. (Fig.1121,d.) Miocenic—Pliocenic.

Fic. 1121. (a-c, upper three, left to right; d, e, lower two); a, Fulgur rapum
var.; 0, J. tritonis,; c, F. maximus, ad, F. contrarium, e, Sycotypus excavatus. All

xX %. (After Grabau. )

Reversed; earliest whorls noded, adult smooth.

Duplin beds of the Carolinas; Caloosahatchie beds of Florida.
(Reversed species with the character of F. tritoms or F. rapum
(F. obrapum Grabau) and one with the characters of F. caricum
(F. perversum) occur in the Pliocenic-Recent deposits of the
Atlantic coast.

CLVI. Sycotypus Browne.

Like Fulgur in form, but with a canaliculate suture and typi- .
cally without spines, the tubercles of the young often uniting into
a smooth keel in the adult. Miocenic—Recent.

542. S. rugosus (Conrad). (Fig. 1122.) Miocenic.

Shoulder angle nodulated throughout, the nodes in the adult
becoming broad and subconfluent.

770 NORTH AMERICAN INDEX FOSSILS.

Chesapeakean formation of the Atlantic coast.

543. S. canaliculatus (Linn.). Pliocenic—Recent.
Young whorls nodulated, adult with more or less strongly
developed carina.
Pliocenic of the Carolinas; Pleistocenic and Recent, Cape Cod
to Gulf of Mexico.

544. S. pyriformis (Conrad). Miocenic.
Young whorls tubercled, later keeled ; adult with rounded whorls.

Fic, 1122. Sycotypus rugosus, X 2%. (Md. Survey.)

Miocenic of North Carolina. In S. pyrus of the modern fauna
the rounded outer lip begins early, the curvature being continuous
from the sutural canal.

545. S. excavatus Conrad. (Fig.1121,e.) | Miocenic—Pliocenic.
Differs from the preceding in having the outer lip of last whorl

continuous without shoulder angle, and with sharp posterior notch.
Duplin beds of Carolinas.

CLVII. StrepsipurA Swainson.
Like Fulgur but with short, curved canal, higher spire, and
whorls often ribbed. Eocenic—Miocenic.
546. S. subscalarina Heilprin. (Fig. 1123, a-c.) Eocenic.
Primitive varieties (Fig. 1123, a) high-spired; whorls rounded
or subangular, and ribbed, specialized varieties (Figs. 1123, c, b)

GASTROPODA—FULGURIDZ. 771

with later whorls strongly embracing, angular, the ribs reduced to
sharp nodes and the shoulder flat. Spirals numerous, intercalated ;
inner lip callous; outer lip lirate.

Pamunkey formation of Maryland and Virginia.

Fic. 1123. a, Strepsidura subscalurina ; b, c, var. nodosus. (Md. Survey.)

CLYVITI. Levirusus’ Conrad:

General form like a small Fulgur but generally with a second
angulation on the body of the whorl; canal of varying length, outer
lip lirate; protoconch of several gradually increasing, smooth
whorls.

547. L. trabeatus Conrad. (Fig. 1124, a.) Eocenic.
Whorls of spire exposing part of body below the angulation; a

second angulation in line with posterior end of lip, flat nodules on

both angulations, outer lip strongly lirate. Canal slightly bent.

Fic. 1124. a, Levifusus trabeatus,; b, L. pagodiformis. (After Harris. )

772 NORTH AMERICAN INDEX FOSSILS.

Midwayan to Claibornian from Alabama to Texas; Nanjemoy
of Maryland (?).
548. L. pagodiformis Heilprin. (Fig. 1124, b.) Eocenic.

Whorls embracing to angulation, the flat tubercles of which
show just above the suture; shoulder concave, steep, second angu-
lation wanting, canal straight.

Midwayan and Chickasawan of Alabama.

CLIX. FAScIoLARIA Lamarck.

Protoconch and the young whorls typically of the fusoid type,
later whorls ribbed and spiraled, with a sharp angulation and flat
shoulder or with rounded whorls. Canal shorter than in Fulgur
and spire longer. Columella with two or three oblique plications in
anterior end, and in typical forms with a strong, oblique anterior
angulation. Cretacic—-Recent.

549. F. (Cryptorhytis) utahensis (Meek). (Fig.1125.) Cretacic.

Whorls embracing to shoulder angle, shoulder of later whorls
flat, earlier ones rounded; ribs faint or condensed to tubercles;
body whorl gradually contracting to slightly bent canal. Colu-

Fic. 1125. asciolaria (Cryp- Fic. 1126. Fasciolaria (Ptestrochetlus)
torhytis) utahensis. (After Stan- culbertsoni, views of two fragmentary speci-
ton. ) mens; a, type broken below; 4, not show-

ing columellar plaits and with broken spire.
(After Meek. )

mella with one strong-fold so far back that it is hardly visible in
a perfect specimen.

Colorado formation of Utah and Colorado. (Pugnellus sand-
stone. )

GASTROPODA—FUSIDE. 773

550. F. (Piestrocheilus) culbertsoni M. and H. (Fig. 1126.)
Cretacic.
Fusiform spire of length of aperture; whorls round; suture
scarcely impressed; surface with rounded, low ribs which become
obsolete in adult of many specimens; spirals uniform; from one to
four plaits on columella, not visible at aperture.
Fox Hills of Moreau, River, and of Black Hills of Dakota.

Family Fusip&.

CLX. -Fusus.. Lamarck.

Spindle-shaped, with spire and canaliculate rostrum of about
equal length in typical forms; protoconch oblique and smooth in
early, ribbed in later whorls; abruptly defined from conch which

Fic, 1127. a, Fusus hattensis; 6, F. henekent. (After Guppy, Q. J.G.S., XXXII.)

begins with round ribbed whorls; later whorls often angular and
nodose; body whorl abruptly contracted to canal; lips smooth.
Eocenic—Recent.

774 NORTH AMERICAN INDEX FOSSILS.

551. F. henekeni Sowerby. (Fig. 1127, D.) Oligocenic.
Whorls round, rather closely embracing, with stout round ribs

and simple spirals, with intercalated secondary ones in the later
whorls.

Bowden beds of San Domingo and Jamaica.
552. F. haitensis Sowerby. (Fig. 1127, a.) Oligocenic.
Like the preceding, except that the last two whorls show flatten-

ing of the shoulders and peripheral angulation, with rude nodes.
Occurs with the preceding.

Fusoip SHELLS OF UNDETERMINED RELATIONSHIP.
CLXI. Fatsitrusus Grabau.
Like Fusus in general form, but with protoconch consisting of
a number of gradually enlarging, smooth whorls merging into the
conch, the whorls of which early become angular. Eocenic.

553. F. meyeri (Aldrich). (Fig. 1128.) Eocenic.

Fic. 1128. Falsifusus meyert. Fic. 1129. Fulguro- Fic. 1130. Fulguro-
(After Harris. ) fusus quercollis, (After fusus rugatus. (After
Harris. ) Harris. ) :

Whorls angular almost throughout; ribs and simple spirals con-
tinue to lip; spire and canal of equal length, very slender. _
Midwayan and Chickasawan of Gulf States.

GASTROPODA—FUSOIDEA. 775

CLXII. Fuxcurorusus Grabau.

Like Fusus in form; protoconch oblique and without ribs as in
Fulgur, merging into an angulate conch which throughout has con-
cave or flat shoulders and a sharp, peripheral keel bearing nodes.
Eocenic. ,

554. F. quercollis (Harris). (Fig. 1129.) Eocenic.
Carina with sharp, flat nodes; spirals faint; sutures very deep.
Lower FEocenic of Alabama, etc.

555. F. rugatus (Aldrich). (Fig. 1130.) Eocenic.
Nodes of keel spinose in adult; spirals on body strong, some-

times spinulose; suture less depressed than in preceding.

With the preceding.

CLXIII. HeErLtprinia Grabau.

Fusoid shells with protoconch ribbed throughout, body whorl
more or less abruptly contracted into the canal. Columella usually
plicate in adult, outer lip commonly lirate. Pliocenic—Recent.

The more loose-coiled forms with larger spire and less con-
tracted aperture are referred to Barbarofusus Grabau and Shimer
gen nov., type B. barbarensis.

556, H. equalis (Emmons). (Fig. 1131, b.) Miocenic.

Fic. 1131. @, Heilprinia caloosaensis; 6, H. equalis ; c, H. caloosaensis var.; all
about 4 nat. size. (After Dall.)

776 NORTH AMERICAN INDEX FOSSILS.

Differs from H. caloosaensis in having the last whorls free from
indications of ribs, well rounded and strongly marked by spirals.
Both outer and inner lip strongly lirate on apertural side.

Cape Fear River Miocenic of North Carolina.

557. H. (Barbarofusus) exilis (Conrad). Miocenic.
Later whorls rounded, owing to prominence of first shoulder
spiral; ribs disappear in later whorls; spirals compound; aperture
less sharply contracted than in preceding.
Miocenic or Upper Oligocenic of Florida.

558. H. caloosaensis (Heilprin). (Fig.1131,a@andc.) Pliocenic.
Shoulder of later whorls flat but angle not pronounced, ribs
faint on later whorls; spirals mostly primary, more rarely fine
secondary ones intercalated; aperture and whorl abruptly con-
tracted to the slender canal which is slightly sinuous; inner lip
strong, multiplicate; outer lip strongly lirate.
Pliocenic of Florida and the Carolinas.

559. H. (Barbarofusus) barbarensis (Trask). (Fig. 1132).

Pliocenic.
Spire slender, whorls round, sutures deep, apical angle 30° or

Fic. 1132. Hetlprinia ( Barbarofusus) Fic. 1133. Zxilia pergracils.
barburensis, X 1.5. (After Arnold. ) (After Harris. )

GASTROPODA—FUSOIDEA. 977

more, ribs narrow, twice their width apart, often obsolete on last
whorl; spirals strong; canal of moderate length, outer lip lirate
within.
Pliocenic of California coast,
500. H. (Barbarofusus) robusta (Trask). Pliocenic—Recent.
Like the preceding but shoulders more flattened and whorls
more bulging in adult; shell shorter and less slender.
Pliocenic—-Recent of California coast.

CLAcl V2 -ExiLta Conrad:

Slender, fusoid shells with sutures not deeply impressed, surface
with regular ribs and aperture gradually contracted to long canal.
Eocenic.

561. E. pergracilis Conrad. (Fig. 1133.) Eocenic.
About twelve rounded volutions with faintly sigmoidal ribs,
more than their width apart; straight canal, shorter than spire;
spirals fine.
Midwayan of Alabama and Mississippi.

CLXV. Latuyrus Montford.

Fusiform but thicker and more solid than Fusus; generally
with a straight canal shorter than in Fusus; columella with two or
three plaits anteriorly; sometimes umbilicated; whorls with ribs
and spirals; outer lip lirate within; generally angulated. Cretacic—
Recent.

562. L. floridanus Heilprin. (Fig. 1134.) Eocenic—Miocenic.
_ Whorls round but shoulder flattened; ribs dying away towards
suture; spirals pronounced with very fine secondary ones; lire
strong ; columella with two obscure plaits; outer lip with additional
lire in adult specimens.

Nummulitic (Eocenic) beds of Tampa and Miocenic silex beds
of Ballast Point, Florida.

CLXVI. STREPTOLATHYRUS Cossman.
Differs from Lathryus in its strongly twisted canal which pro-
duces a corresponding change in columella; surface with or with-
cut ribs. Eocenic.

778 NORTH AMERICAN INDEX FOSSILS.

563. S. interstriatus (Heilprin). (Fig. 1135.) Eocenic.
Whorls round; suture moderately deep; ribs simple and con-
tinuous from suture to suture, about their width apart; spirals

Fic. 1134. Lathyrus florida Fic. 1135. Streptolathyrus interstriatus, en-
RUSK 18. Chater Dall; ) larged. (Md, Survey. )

numerous ; compound columella with one strong oblique plication;
lire of outer lip rather strong. |

Pamunkey formation of Maryland and Virginia; Chickasawan
(Lignitic) of Alabama.

CLXVII. PsEupoLtatHyrus Bellardi-

Shell fusiform, with protoconch of Falsifusus type. Whorls
mostly angular with ribs and spirals, the former often becoming
obsolete except on angle. Canal straight, not twisted, non-umbili-
cate; columella plicate in adult. ocenic—Pliocenic.

564. P. tortilis (Whitfield). (Fig. 1136.) Kocenic.

Whorls angulated; shoulder flat; ribs weak, far apart, scarcely
extending below angulation; embracing of whorls falls short of
angulation by half the shoulder width; contraction to canal grad-
ual; columella with two plice, the upper one faint. Spirals com-
pound.

Midwayan of Alabama, Georgia and Mississippi.

CLXVIII. Lrrorusus Conrad.
Short, thick-spired, fusoid shells with short, somewhat inflated
canal, pyriform aperture, and lirate outer lip; no columellar plica-
tions. Eocenic.

GASTROPODA—FUSOIDEA. 779

565. L. subtenuis (Heilprin). (Fig. 1137.) , Eocenic.
Whorls rounded but with a flattening above the last spiral, and
below the strong subsutural spiral, which sometimes produces a
channeling of the suture; spirals strong and simple. Ribs well
defined on young whorls, but fainter or obsolete on the adult.

Fic, 1136. Pseudolathyrus tortilis. Fic, 1137. Lirofusus subtenuis, en-
(After Harris. ) larged. (Md. Survey. )

Pamunkey of Maryland and Virginia; Chickasawan (Lignitic)
of Alabama.
CLXIX. Futcuroricus Sacco.

Shell small, fulguroid, with low spire, and patulous, wide canal,
and several peripheral angulations. Surface with ribs which
become sharply nodose on the angulations. Eocenic.

566. F. argutus Clark. (Fig. 1138, a, D.) Eocenic.

, :

Pic. 1138. a, 6, Pulguroficus argutus ; c,d, Fusoficula juvenis. (Md. Survey. )

Body whorl with three strong angulations rather far apart, and
nodose where they cross the thin, rather sharp and distinct ribs ;
early whorls more or less rounded.

780 NORTH AMERICAN INDEX FOSSILS.

Pamunkey of Maryland and Virginia; Chickasawan (Lignitic)
of Alabama.
CLXX. FusoFicuLa Sacco.

Differs from the preceding in its higher spire, less pronounced
angulations and less patulous aperture. LEocenic.

567. F. juvenis (Whitfield). (Fig. 1138, c, d.) Eocenic.

Shoulder flat to concave with ribs nodose on angle and extending
a short distance above and below; whorls embracing to a second,
sharp, smooth, peripheral angulation below which is a third fainter —
one; space between angulations concave, marked by numerous fine |
spirals.

Pamunkey (Aquia) of Maryland; Chickasawan of Alabama
and Texas.

CLXXI. Opontorusus Whitfield.

Fusiform, round-whorled, ribbed shells, with rather short canal
and a single oblique plication near the center of the columella.
Cretacic.

568. O. medians Whitfield. (Fig. 1139.) Cretacic.

Fic. 1139. Odontofusus medians. (After Whitfield.)

Whorls round; ribs straight, thin and distant; aperture broad; —
canal short.
Ripleyan of New Jersey and Mississippi.

CLXXII. CLAvILITHES Swainson.

Fusiform shells with cylindrical protoconch of many whorls ;
early whorls ribbed and spiraled, later ones generally smooth, more
elongate and flattened ; a posterior canaliculation with sutural shelf
generally occurs. |
569. C. kennedyanus Harris. (Fig. 1140.) Eocenic.

Early whorls strongly ribbed, somewhat concave below the

GASTROPODA—TURBINELLIDZ. 781

suture; later whorls smooth, flat, with scarcely impressed suture;
outer lip gently rounded; body whorl abruptly constricted to
canal.

Chickasawan and lower Claibornian of Alabama and Texas.

CEX RIL. Fea Cinta Conrad: e

Melongenoid shells, with body whorl marked by angulations or
spirals, umbilicated aperture with callous columellar lip. Eocenic.

570. L. alveata Conrad. (Fig. 1141.) Eocenic.

Fig. 1140. Clavilithes kennedya- Fic. 1141. Sacinia alveata. (After
mus var. (After Harris.) Conrad. )

Large, subglobose, thick body whorl with channeled suture;
several angulations with flat or concave interspaces, a strong obtuse
carina around umbilicus; aperture, large, patulous; inner lip
strongly callous, reflected. |

Claibornian of Alabama.

Family TuRBINELLIDAZ Swainson.
CLXXIV. TurpineLta Lamarck.

Similar to Clavilithes but generally without shelf, and with
strong columellar folds; protoconch long and papillose. A dis-

782 NORTH AMERICAN INDEX FOSSILS.

tinct shoulder occurs im some species,
with the ribs noded on the angle. The
last whorl generally smooth, but may
retain the ribs and nodes as irregular
folds. Oligocenic—Recent.

571. T. wilsoni Conrad. (Fig. 1142.)
Oligocenic—Miocenic.
Differs from the next species in
its smooth, somewhat subcylindrical,
or flattened last whorl, in the number
of ribbed young whorls (7 or more);
concave shoulder, rather steeply in-
clined, angle rounded and faintly and
bluntly nodulated; faint spirals on
lower part of body whorl.
Vicksburgian of Mississippi; Alum
Bluff beds of Florida.
572. T. chipolana Dall. (Fig. 1143.)
Oligocenic—Miocenic.
Young whorls (two or three) with
coarse ribs which become obsolete
later on; last whorl round; interca-
lated spirals between the strong pri-
Fic. 1142. Zurbinella wilsoni. Mary ones; columella with three
(After Conrad. ) oblique folds; protoconch cylindrical,
of many whorls.
Chipolan and Alum Bluff beds of Florida.

CLXXV. Vasum Link. (Cynodonta Schum.)

Like Turbinella but with flat or concave shoulder and angle
with strong, coarse and flat spines; one or more additional rows
of spines on the lower part of whorl. Oligocenic—Recent.

573. V. haitense Sowerby. (Fig. 1144.) Oligocenic—Miocenic.

Spire high, acute, of flat-ribbed whorls, rapidly broadening out
in last 2 or 3 whorls which have concave shoulder and strong,
triangular, compressed spines; a second row of smaller, sharp
spines near base; spirals faint. The variety engonatum (Dall)
has more spines and less elevated and less acute young spire.

GASTROPODA—TURBINELLIDEZ. 783

Lower Miocenic (Oligocenic?) of Santo Domingo, Chipolan beds _
and Alum Bluff beds of Florida.

574. V. horridum Heilprin. Pliocenic.

Fic. 1143. Zurbinella chipolana, Fic. 1144. Vasum haitense,< %.
young shell, 1.2. (After Dall.) (After Sowerby. )

With numerous, strong, compressed, slightly upward curving
spines opening forward, and covering most of the spire and body
whorl.

Caloosahatchie beds of Florida.

CLXXVI. Mazzattna Conrad.

Shells thick, of smooth, strongly convex whorls
contracted below to a curved canal; outer lip regu-
larly curved; a faint posterior canal generally devel-
oped; typically with columellar plaits. Eocenic—
Recent.

575. M. (Bulbifusus) inaurata (Conrad). (Fig.

1145.) Eocenic.
Suture sunken from thickening of whorl just
below ; columella smooth. Fic, 1145.

Represented by numerous varieties in Chicka- 4720"? (8

; } : bifusus) inaurata
sawan, Claibornian and Jacksonian beds of the Gulf ,,, plena, (After

States. Harris. )

784 NORTH AMERICAN INDEX FOSSILS.

Family Muricip2# Tryon.
CLXXVII. UrosaLtpinx Stimpson.

Short and thick fusiform shells with spire of few regularly
enlarging whorls, and with an anterior canal of moderate length,
often slightly bent; aperture pyriform, outer lip often denticulate.
Surface with ribs and spirals. Tertiary—Recent.

570. Mh. rustica (Conrad). (Fig. 1146, a, b.) Miocenic.

Fic. 1146. a, 6, Urosalpinx rustica; c,d, U. cinerea. (Md. Survey.)

More slender than U. cinereus, shoulder somewhat flatter, pri-
mary spirals strong, secondary and later numerous. Inside of
outer lip strongly toothed or lirate.

Chesapeakean of Atlantic coast.

577. U. cinerea Say. (Fig. 1146, c, d.) Miocenic—Recent.

Whorls rounded, rarely with a shoulder flattening, no angula-
tion, ribs narrow, round and distant, becoming obsolete above and

Fic. 1147. Urosalpinx (Scalaspira) strumosa, two varieties. (Md. Survey.)

below, often wanting on body whorl; spirals numerous, not coarse,
in several cycles.

GASTROPODA—MURICIDZ. 785

Chesapeakean of Maryland and Virginia; Pliocenic—-Recent on
southern Atlantic coast of United States.
578. U. (Scalaspira) strumosa (Conrad). (Fig. 1147.) Miocenic.

Differs from the other species in its flat shoulder and flat sides
of whorls, marked by two or three very strong spirals, the lower
one covered at the suture and cancellated by narrow, distant, ver-
tical ribs.

Chesapeakean of Maryland and Virginia, etc.

Chee Vitti: . Morsx: Linn:

Round whorled or angular whorled fusiform shells, the spire
ribbed and with spirals, aperture drawn out anteriorly into a
straight or curved canal; outer lip expanded into a varix with or
without simple or compound spines; varices of former aperture
persistent, three or more to a volution. This includes a number of
distinct genetic series. Cretacic—Recent.

579. M. mississippiensis Conrad. (Fig.1148.) Oligocenic—Recent.

Small, with three non-spinous varices and often two or more
faint, rounded ribs between the varices; spirals compound, strong,
often crowded; canal strongly deflected, very narrow.

Vicksburgian beds of Mississippi; Chipolan and Silex beds of
Florida.

580. M. (Chicoreus) rufus Lamarck. Miocenic P—Recent.

Of moderate size, with three varices of much divided or fron-

Fic. 1148. Murex mississippiensts. Fic. 1149. TZyphis curvtirostratus.
(After Conrad. ) _ (After Conrad. )

dose spines, with a single large rib between the varices, anterior
end of canal deflected.

Miocenic of North Carolina; Pliocenic of Florida; Post-Plio-
cenic of Antilles; living from Cape Fear, N. C., to the Gulf.

786 NOKTH AMERICAN INDEX FOSSILS.

CLXXTX.: Tyvpris Montfort:

Like Murex, but the varices are rib-like, the spines are hollow
and less regular, and the short anterior canal is completely closed.
Cretacic—Recent.

581. T. curvirostratus Conrad. (Fig. 1149.) Oligocenic.

Spire somewhat lower than the next; sides of whorls more nearly
straight; ribs strong and ending in vertical spines; aperture small
and round; anterior beak strongly curved.

Vicksburgian of Mississippi.

582. T. acuticosta Conrad. (Fig. 1150, a,b.) Miocenic.

Fic. 1150. a, 6, Zyphis acuticosta ; c, da, Trophon tetricus. (Md. Survey. )

Whorls with four or five varices ending at the shoulder angle
in compressed spines, alternating with four shorter, rounded varices
ending in hollow spines or tubes. Rostrum slightly reflected.

Chesapeakean formation of Atlantic coast.

583. T. obesus Gabb. Oligocenic—Pliocenic.

Short and broad with low spire; whorls sharply angulated, con-
cave above and convex below suture; four varices to each whorl,
acute-angular on their margins and ending in blunt process on
upper angle of whorl; shell swollen at base of tubular spines; sur-
face polished, with few spirals.

Chipolan beds of Jamaica and Florida; Miocenic of Haiti; Plio-
cenic of Trinidad.

CLXXX. TropHon Montfort.

Like the preceding, but the varices are lamellose and the canal
open. Tertiary—Recent.

GASTROPODA—PURPURIDZ:. 787

584. T. tetricus Conrad. (Fig. 1150, c,d.) Miocenic.
With 9-12 varices which are sharp and end at the shoulder angle
in compressed open spines; canal long and straight.
Chesapeakean of Atlantic coast.

Family PurPURID Gray.

CLXXXI. Ecpuora Conrad.

Large, short and thick shells, rather loosely coiled towards the
last, leaving a wide umbilicus. Aperture more or less pyriform,
extended into a short anterior canal. Surface marked by coarse
spiral folds, rarely by finer spirals. Muiocenic.

585. E. quadricostata (Say). (Fig. 1151.) -Miocenic.

Fic. 1151. a, Ecphora quadricostata, X 24; 6, var. umbilicata, X 7%; ¢, young,
2.5 (Md Survey?)

Adult shell deeply umbilicated, with four very prominent, pro-
jecting spiral folds, often T-shaped in section, less prominent and
somewhat noded in the young. Variety wmbilicata (Fig. 1151, D)
has a larger umbilicus, looser coil, thinner, not T-shaped spirals.
E. tricostata (Fig. 1152, b) has the lower spiral weak or absent.

Chesapeakean formation of Maryland and Virginia.

586. E. tampaensis (Dall). (Fig. 1152, a.) Miocenic.

Resembles the young of E. quadricostata; spiral folds moderate,
numerous on anterior portion, on main part of whorl with finer

intercalated ones; growth lines lamellose between spirals.
Silex beds of Florida; Chesapeake beds of Maryland.

788 WORTH AMERICAN INDEX FOSSILS.

Fic. 1152. a, Ecphora tampaensis ; 6, E. tricostata. (Md. Survey. )

Family MARGINELLIDZ Jousseaume.

CLXXXII. MarcInettaA Lamarck.

Oval or long shells with smooth exterior, low spire and elongate
aperture which is slightly canaliculate anteriorly; three to four
equal oblique folds on the columella; outer lip often thickened
and dentate. Eocenic—Recent.

587. M. minuta Pfeiffer. (Fig. 1153, a.) Miocenic—Recent.
Spire very low, sunken; last whorl rounded, smooth; aperture
elongate ; columella with four folds in anterior end; outer lip thick-
ened, smooth.
Chesapeakean of Maryland and Virginia; Pliocenic of North
Carolina and Florida; Recent on southern Atlantic coast of North
“America and Cuba.

588. M. virginiana Conrad. Miocenic—Recent.
Larger than the preceding, with the spire low but not sunken;
body whorl tapering forward, giving the shell a Conus-like aspect.
Chesapeakean of Virginia; Caloosahatchie beds of Florida;
Recent off coast of North America from North Carolina to
Yucatan.

589. M. limatula Conrad. Miocenic—Recent..

Small, with low spire and apertural part of last whorl reaching
up and bending over on the spire; four plications near the base of
columella; outer lip denticulate within; aperture widening regu-
larly forward.

GASTROPODA—MITRIDZ. 789

Miocenic of the Carolinas and Virginia; Pliocenic of South
Carolina and Florida; Recent off Carolina coast.

590. M. denticulata Conrad. (Fig.1153,b.) | Miocenic—Recent.
Small; spire high for the genus, of about 5 regularly enlarging
whorls, nearly flat, with suture slightly depressed ; body whorl nar-
rowing towards front; aperture narrow and ovoid, widest in the
middle, with four strong plicze on columella and denticulations on
the outer lip; no anterior notch.
Chesapeakean of Maryland and Virginia; Caloosahatchie beds

Fic. 1153. «@, Marginella minuta; 6, M. denticulata. (Md. Survey.)

(Pliocenic) of Florida; Recent from Cape Hatteras to Florida and
Barbadoes.
Family Mirriw2.

CLXXXITE.. Mrrra Lamarck.

Differs from Marginella in having its spire drawn out, so as to
be longer than aperture, which is slightly notched anteriorly.
Tertiary—Recent.

591. M. holmesii Dall. (Fig. 1154.) Pliocenic.

Spire about twice the length of aperture; sutures moderately
depressed ; whorls somewhat flattened and marked by strong, nar-

Fic, 1154. Mitra holmesii, * 8. FIG. 1155. Conomitra staminea, < 1.8.
(After Dall. ) (After Dall. )

row ribs about twice their width apart. Columella with three pli-
cations, the posterior straight; spirals rounded, equal.

750 NORTH AMERICAN INDEX FOSSILS.

Caloosahatchie beds of Florida.

592. M. (Conomitra) staminea Conrad. (Fig.1155.)
Oligocenic—Recent.
Spire and aperture about equal; whorls rounded; suture moder-
ately depressed; ribs faint; columella with four plications.
Vicksburgian of Mississippi; Miocenic of Florida.

Family VoLuTip@ Gray.
CLXXKIV: © VoLUTILITHES Swainson:

Fusiform or Fulgur-shaped shells with more or less conical
spire; protoconch of several increasing whorls, acute; whorls cos-
tate; aperture elongate and with broad but short canal; columella
plicate, more strongly near anterior end. Cretacic-Recent. (A
number of subgenera, better perhaps regarded as genera, are in-
cluded here. )

593. V. petrosus (Conrad). (Fig. 1156.) Eocenic.

Fic. 1156. Volutilithes petrosus, opposite views, Fic. 1157. Volutilithes
and young. (Md. Survey.) sayana. (After Conrad.)

Young shell Fulguroid, whorls embracing to angle which is spi-
nose, the spines continued downward as ribs; shoulder changing
from round to concave; in adult the whorls are more irregular;
last one with strong spines on the angle; callus of inner lip large,
covering part of whorl and shoulder; presence of earlier calluses
indicated on shoulder of preceding whorls; columella with three
plications.

GASTROPODA—V OLUTIDZ. 791

Pamunkey of Maryland, etc.; Chickasawan and Claibornian of
Alabama, Texas, etc.

594. V.sayanus (Conrad). (Fig. 1157.) Eocenic.
Shoulder angle rather blunt, ribs extending over it, but dying
out on shoulder and short distance below the angle on body whorl;
surface with spirals which cancellate the ribs; columella with four
plications, one of which is obsolete.
Claibornian of Alabama.
595. V. rugatus (Conrad). (Fig. 1158, a.) Eocenic.
Whorls round, with rounded, strong and rather distant ribs
crossed by compound spirals; callus of inner lip reaching only part
way over the whorl; columella with three folds, the middle one
obsolete.
Midwayan of Texas and Alabama.

596. V. limopsis (Conrad). (Fig. 1158, b.) Eocenic.

Fig. 1158. a, Volutilithes rugatus, \eft ; Fic. 1159. Volutomorpha conradi.
b, V. limopsis, right. (After Harris. ) (After Whitfield. )

Like the preceding, but with more numerous, narrower and
sharper ribs cancellated and spinulated by strong, sharp spirals,
especially marked on the ribs.

Midwayan and Claibornian of Texas and Alabama.

262 NORTH AMERICAN INDEX FOSSILS.

597. V. (Volutomorpha) conradi Gabb. (Figs. 1159-1161.)
Cretacic.
Rather large; spire moderate, of rounded whorls with impressed
sutures, sometimes a slight subsutural flattening ; body whorl four
fifths of length, varying in convexity, but contracted to the short

Fic. 1160. Volutomorpha conradi, Fic. 1161. Volutomorpha conradi, in-
internal mold. (After Whitfield. ) ternal mold (After Whitfield. )

anterior canal; ribs narrow, far apart, cancellated by strong spirals;
internal molds commonly smooth.
Ripleyan of New Jersey .
598. V. (Rostellites) biconicus Whitfield. (Fig.1162.) Cretacic.
Spire elongated, forming about half the total length, somewhat
strongly flattened at the suture which in the internal molds is deep.
Ripleyan of New Jersey, etc.

GASTROPODA—V OLUTIDE.. 793

599. V. (Rostellites) texturatus Whitfield. Cretacic.
With short spire and very long, slender body whorl forming
about six sevenths of entire length; aperture long and narrow;

Fic. 1162. Lostellites biconicus, internal mold. (After Whitfield. )

surface marked by strong spirals and weaker lip-like ridges, which
sometimes node the spirals.
Ripleyan of New Jersey, Alabama and Mississippi.

600. V. (Rostellites) dalliStanton. (Fig. 1163,a,b.) | Cretacic.

Fic. 1163. 7,6, Rostellites dali, c,d, R. ambigulus. All < %. (After Stanton. )

Spire moderate; shoulder concave; angle with nodes which con-
tinue downwards as ribs for a short distance; early whorls rounded
and ribbed. Spirals numerous and compound; canal nearly straight.

704 NORTH AMERICAN INDEX FOSSILS.

Colorado formation (Pugnellus sandstone) of Colorado, also in
New Mexico(?).
6o1. V. (Rostellites) ambigulus Stanton. (Fig. 1163, c,d.) Cretacic.

Whorls round but not bulging; sutures moderately depressed ;
earlier whorls with regular, somewhat oblique ribs rather close
together; body whorl with ribs only near suture; canal slightly
curved; two strong oblique plications on the columella, with faint
indications of others.

Colorado formation (Pugnellus sandstone, abundant) of Colo-
rado; Benton of Kansas, also New Mexico(?).

Cx XX: Votura ine

Fusiform or Fulguroid shells with moderate spire of angulated
(except the earliest) whorls, ribbed and generally tubercled on the
angle; adult whorls smooth in certain subgenera; aperture narrow,
canaliculate behind; inner lip often with a thin callus; columella
with numerous plaits of varying strength. Tertiary—Recent.

602. V. musica Linn. Pliocenic—Recent.
Protoconch many-whorled, round, increasing regularly; later

whorls with spirals; early conch whorls round with round ribs,

later ones ribbed and subsequently noded; last whorl with strong

nodes bounding concave shoulder ; columellar plications numerous;

surface marking chiefly in lines and spots resembling musical notes.
Pliocenic of Costa Rica; Recent in West Indies.

CLXXXVI. CariceLtta Conrad.
Like Aurinia, but with four strong columellar plaits. Eocenic.

603. C. pyruloides Conrad. (Fig. 1164.) Eocenic.
Pyriform, smooth, spire low, shoulder flat; body whorl rounded,
tapering regularly to anterior end; columellar plaits four, distant
and oblique.
Claibornian of Alabama; Aquia of Maryland(?).

CLXXXVII. Avurinia Adams.

Like Voluta but generally with rounded adult whorls, which are
free from ribs or spirals; outer lip regularly curved. Tertiary—
Recent.

GASTROPODA—V OLUTIDZ—OLIVIDEZ. 795

604. A. mutabilis (Conrad). (Fig. 1165.) Miocenic.
Long and rather slender; last two or more whorls smooth, but

with concave shoulder; angle rounded; aperture long; canal some-

what curved; plice, two strong and a fainter one between.
Chesapeakean of Maryland, etc.

605. A. typus (Conrad). (Fig. 1166.) Miocenic.

Fic. 1164. Cazicella Fic. 1165. <Aurinia mu- Fic, 1166. Aurinia

pyruloides, x 24. (After tabilis, X24. (Md. Survey. ) typus, X 2%. (Md. Sur-
Conrad. ) vey.)

Shorter and more robust than preceding; aperture broadening
towards the front. Two columellar plications present.
Chesapeakean of Maryland, Virginia, etc.

Family Ovtivip#& d’Orb.
CLAXXVITEOriva Brug:

Shell of subcylindrical outline, smooth and shining, with short
spire and long body whorl; sutures sharply depressed; aperture
narrow; columella with oblique folds. Cretacic—-Recent.

606. O. litterata Lamarck. (Fig. 1167.) Miocenic—Recent.

Slightly inflated above the middle; suture canaliculate ; columella
plaited throughout.

_ Miocenic of New Jersey, Maryland, North Carolina, west of
Florida to San Domingo, Jamaica; Pliocenic of the Carolinas and

796 NORTHVUAMERICAN INDEX FOSSILS.

Caloosahatchie beds of Florida; Pleistocenic of South Carolina
and Florida; Recent off North Carolina and West Indies.

607. O. (Olivella) alabamensis Conrad. (Fig. 1168.) Eocenic.

Fic. 1167. Oliva titterata. (Md. Fic. 1168. Ofivella alabamen-
Survey. ) sts. (After Conrad. )

Spire acute, elevated, whorls scarcely round and suture faintly
impressed, a notched spiral above the suture; aperture rather
broad; a notched band near base of body whorl.

Claibornian of Alabama, abundant and variable, especially in
‘length of spire.

608. O. (Olivella [Dactylidia]) mutica Say. Miocenic—Recent.

Small, tapering towards both ends; spire proportionally high;
aperture about half the length of the shell, narrow; columella
smooth.

Miocenic of San Domingo, to North Carolina; Pliocenic of

Fic. 1169. Olcvula Fic. 1170. Amncillopsis Fic. 1171. Cancellaria con-

staminea, X %. (After szbglobosa, XK %%. (After vadiana, nat. size. ( After
Conrad. ) Conrad. ) Dall. )

Florida; Pleistocenic of Florida to South Carolina; Recent, West ,
Indies to Carolina coast.

GASTROPODA—CANCELLARHDE. 797

CLXX XIX. - Onivuca: -Gonurad.

Vertically striate, Oliva-like shells with somewhat channeled
suture.
609. O. staminea Conrad. (Fig. 1169.) Eocenic.

An impressed line just below the suture constricts off a sub-
sutural band; aperture rather broad posteriorly; columella ante-
riorly with striated callus; surface with strong vertical, and faint
revolving lines.

Claibornian of Alabama and Texas.

CXC. ANCILLOPsIS Conrad.

Subglobular; with short spire and large body whorl; inner lip
with strong callus. Differs from Ancilla chiefly in its subglobose
form. LEocenic.

610. A. subglobosa Conrad. (Fig. 1170.) Kocenic.

Subglobose to suboval; apex sharply pointed; suture obsolete;
columella with profound callus projecting in the middle.

Claibornian of Alabama.

Family CANCELLARIIDAZ Adams.
CXCI. CANCELLARIA Lamarck.

Moderately spired shells, with generally round whorls; inflated
body whorl; broad aperture with short canal or notch; columella

Fic. 1172. a, Cancellaria graciloides, XK 4; b, C. alternata, X 3; c, C. alternata
var., X $5 @, C. lunata, X 3; ¢, C. (Trigonostoma) biplicifera, xX 2, (Md.
Survey. )

with several strong oblique plicze; ribs commonly cancellated by

the spirals. Cretacic—Recent.

611. C. graciloides Aldrich. (Fig. 1172, a.) Eocenic.
Whorls elongate-rounded ; suture deeply depressed, with a slight

798 NORTH AMERICAN INDEX FOSSILS.

subsutural flattening; spirals numerous, finely nodulated; no ribs;
outer lip expanded and toothed; columella with three folds.

Aquia formation of Atlantic coast; Chickasawan of Gulf coast.
612. C. conradiana Dall. (Fig. 1171.) Oligocenic.

Whorls somewhat flattened on the side, and with a rather pro-
nounced subsutural flattening; ribs strong, distant; spirals of
almost equal strength, numerous; columella with three sharp
plaits.

Chipolan beds of eastern United States.

613. C. alternata Conrad. (Fig. 1172, b,c.) Miocenic.
Round-whorled, subglobose; with strong round ribs, thicker in
the middle, crossed by sharp spirals; aperture broad; outer lip
lirate ; columella with two strong folds. —
Chesapeakean of Atlantic coast.

614. C. lunata Conrad. (Fig. 1172,d.) Miocenice.
Higher spired than preceding though low coiling; ribs farther

apart; aperture drawn out into a somewhat longer canal.
Chesapeakean of Atlantic coast.

615. C. (Trigonostoma) biplicifera Conrad. (Fig. 1172, e.)
Miocenic.
Larger, with a well developed subsutural shelf, rather strongly
channeled; coarse irregular ribs on the body whorl; the aperture
with both anterior and posterior canaliculation; the outer lip lirate;
the columella with strong callus and two plications.
Chesapeakean of Maryland.

Family TEREBRIDA Adams.
CXCII. Trresra Lamarck.

Shell usually high-spired, slender and acuminate, whorls regu-
larly enlarging, body whorl not inflated; aperture with short,
curved canal, generally sharp or slightly canaliculate posteriorly.
Surface of whorls smooth or ribbed; a depressed spiral occurs a
short distance below the suture constricting off a subsutural band;
this is weak or wanting in the subgenus Acus, Humphrey. Ter-
tiary—Recent.

616. T. unilineata Conrad. (Fig. 1173,a, 0.) Miocenic.
Constricting spiral prominent, the space between it and the suture

GASTROPODA—TEREBRIDE.. 799

above, being marked by short, oblique, rib-like undulations gen-
erally wanting in the older whorls. Surface otherwise smooth,
except for oblique lines of growth.

Chesapeakean of Maryland; corresponding beds of North
Carolina.

617. T. (Acus) curvilineata Dall. (Fig. 1173, c-f.) Miocenic.
Shorter and less tapering spire than preceding, whorls with

Fic. 1173.
ations; g, 7. curvilirata; h, T. (Hastula) simplex; i, var. sublirata. (All from
Md. Survey. )

vertical ribs, the subsutural depressed spiral faint or obsolete.
In variety whitfieldi, Martin (Fig. 1173, c, d) the ribs are strong
but narrow and vertical, while fine sharp spirals mark the spaces
between the ribs. Aperture narrow. In variety dalli Martin
(Fig. 1173, e) the ribs are obsolete except just below the suture;
while in the variety calvertensis Martin (Fig. 1173, f), the sub-
sutural, depressed spiral is rather strong, the ribs being nodulated
upon the band thus produced.
Chesapeakean of Atlantic coast from New Jersey south.

800 NORTH OAMERTCAN INDEX FOSSILS.

618. T. curvilirata Conrad. (Fig. 1173,g.) Miocenic.
With ribs curving backwards and slightly nodose on subsutural
band.
Chesapeakean of Atlantic coast.

619. T. (Hastula) simplex Conrad. (Fig.1173,h,1.) |Miocenic.
With broader apical angle (broadest in var. sublirata Conrad,

Fig. 1173,17). Surface smooth except for curving lines of growth.
Chesapeakean of Atlantic coast.

Family PLEUROTOMID# Stoliczka.
CXCIII. PLeurotoma Lamarck.

Fusiform shells with rather high spire, and more or less con-
stricted anterior canal of equal length with the spire; whorls var-
iously ornamented with ribs and spirals, rarely smooth; outer lip
with a notch or more or less deep slit, generally on the shoulder
angle; columella smooth; operculum horny, with apical nucleus.
Cretacic—Recent.

(This group contains a large number of distinct genetic series,
which include many distinct genera. )

620. P. (Surcula) persa Whitfield. (Fig. 1174.) Eocenic.

Volutions rounded below but with concave shoulder, embracing
to lower side of rounded angle which is prominent above the

Fic. 1174. Surcula persa. Fic. 1175. Surcula ostrarupis.
(After Harris. ) (After Harris. )

suture; notch broad on the shoulder; surface marked only by
spirals and lines of growth.
Midwayan of Alabama.

621. P. (Surcula) ostrarupis Harris. (Fig. 1175.) Eocenic.
Broader than preceding, with shorter, more curved canal, more

GASTROPODA—PLEUROTOMIDE. Sol

concave shoulders and short, sharp riblets on the shoulder angle
and just below it.
Midwayan of Alabama and Texas.

622. P. (Hemipleurotoma) childrani Lea. (Fig.1176.) Eocenic.
Aperture one third of the length of the shell; shoulder concave
with moderate sinus in lip; angle pronounced, strongly tubercled;
suture channeled ; surface with strong spirals, generally granulated.
Aquia formation of Atlantic coast; Chickasawan of Gulf coast.
623. P. moorii Gabb. (Fig. 1177.) Eocenic.
Slender, with long, contracted canal, shoulders moderately con-
cave, with notch; shoulder angle carinate, a second weaker carina

ea
been Ww 3 WS

Fry

we

oe

Fic. 1176. Pleurotoma ( Hemipleu- Fic.1177. Pleu- Fic. 1178. Pleuro-
rotoma) childrani, much enlarged. vrotoma moorii. (Aft- toma terebralis, (After
(Md. Survey. ) er Harris. ) Harris. )

en body of whorl, just above the suture, the space between the
two being concave; surface with spirals and lines of growth only.
Chickasawan (Lignitic) of Alabama and Texas.
624. P. terebralis Lamarck. (Fig. 1178.) | Eocenic.
Like the preceding but broader, the upper angle more strongly
carinate and faintly tubercled; the lower carina and the stronger
spirals also granulate.
Midwayan of Gulf States, also European.

625. P. (Hemipleurotoma) albida Perry. (Fig. 1179, a.)
Oligocenic—Miocenic.
Canal less than half the length of the shell; shoulder with a
marked median angulation ; body with a strong carina at the suture .
and a fainter one between this and the main angulation which bears
the notch; additional spirals on body whorl.

802 NORTH AMERICAN INDEX FOSSILS.

Chipolan beds of the Gulf States; Chesapeakean of Maryland.
626. P. (Hemipleurotoma) communis Conrad. (Fig. 1179, b, c.)

Miocenic.
Whorls divided midway by a strong, slender carina which bears

Fic. 1179. a, Pleurotoma ( Hemipleurotoma) albida ; b,c, P. (H.) communis ;
ad, P, (Surcula) marylandica,; e, P. (S.) biscatenaria,; f, Drillia incilifera; g, D.
incilifera-distans ; h, D, limatula ; 1, Mangilia parva; 7, Surcula engonata.

the notch; surface on either side flat or concave; a second stronger
spiral just at or above the suture, and a third below this on the
body whorl; canal less than half the length of the shell. In
variety protocommunis Martin (Fig. 1179, c), additional interca-
lated spirals occur.

Chesapeakean of Atlantic coast.

627. P. (Surcula) marylandica Conrad. (Fig.1179,d.) Miocenic.

Slender, with attenuated canal; deep reentrant shown by growth
lines on shoulder which is concave but not limited by an angula-
tion, the whorls being regularly rounded below; growth lines lamel-
lose at intervals, giving a rib-like appearance; spirals numerous

GASTROPODA—PLEUROTOMIDE. 803

but faint; whorls appressed below the suture, forming a sub-
sutural band.

Chesapeakean of Atlantic coast.
628. P. (Surcula) biscatenaria Conrad. (Fig.1179,e.) Miocenic.

Larger and more robust than preceding, with three strong spirals
at the ambitus of the whorls, the upper one double, the lower one
commonly divided at the suture; interspiral spaces concave; canal
curved at the base.

Chesapeakean of Atlantic coast.

629. P. (Surcula) engonata Conrad. (Fig.1179,7.) Miocenic.
Fusiform, with strong nodules on the shoulder angle and concave
shoulder; nodes not continued as ribs.
Chesapeakean (St. Mary’s) of Maryland.

CXCIV. DriLiia Gray.

Like Pleurotoma in general form but with a short canal; aper-
tural notch gentle. ‘Tertiary—Recent.

630. D. ostrearum Stearns. Oligocenic—Recent.
Fusiform, high-spired, with narrow, concave shoulder bounded
by a subsutural spiral; ribs numerous, close-set, cancellated by
spirals. Length, 16 mm.
Chipolan beds of Florida; Caloosahatchie (Pliocenic) of Florida;
Recent from North Carolina to Yucatan.

631. D. abundans Conrad. Oligocenic—Recent.
Canal about half as long as the spire; nearly straight; whorls
depressed convex, with a subsutural concavity, and a crenulated
spiral; ribs acute, nearly straight.
_ Vicksburgian of Mississippi; Caloosahatchie (Pliocenic) of
Florida.
632. D. incilifera (Conrad). (Fig.1179,f,g.) | Miocenic.
Shoulder concave, with three strong spirals, the lower covered
except in body whorl, the upper two noded by incomplete ribs.
In the variety angulata Martin the angle is marked by coarse, round
regular nodes which appear just above the suture, and the apical
angle is broader. In var. distans Conrad, the apical angle is higher,
the spire is higher and the nodes elongated downwards. The
shell is also less abruptly contracted at the base.
Chesapeakean of Atlantic coast.

804 NORTH VAAMERICAN INDEX FOSSILS.

633. D. ebenina Dall. (Fig. 1180.) Miocenic—Recent.
Whorls round, a sharp, revolving keel flanked by concave sur-
faces at the suture. Ribs narrow, widely separated, gently convex
forward; spirals fine; aperture elongate ; canal very short.
Miocenic of San Domingo; Caloosahatchie (Pliocenic) of
Florida; Recent in Gulf of Mexico.

634. D. limatula (Conrad). (Fig. 1179, h.) Miocenic.

With concave shoulder and strong, nodulose ribs which begin at
the angulation and extend below the suture; no spirals; var. dis-
similis Conrad has the ribs obsolete on the later whorls, sometimes

Fic. 1180. Drillia ebenina, K Fic. 1181. Mangilia infans.
2,4. after Dall”) (After Harris.)

wholly wanting; in var. pyramidalis Martin the ribs are strong but
the apical angle is much greater than in the typical form. —
Chesapeakean of Atlantic coast.

CXCV. MawnciriA Risso.

Small, differs from Pleurotoma in having the notch at the suture,
and in its short truncate canal; inner margin varicose. Eocenic—
Recent.

635. M. infans Meyer. (Fig. 1181.) Eocenic.
Aperture and canal about one third of the length; shoulder
concave, with a spiral just below the suture, and several just below
the median (main) carination; of these only one is visible on the
earlier whorls, being covered by the later ones.
Chickasawan and Claibornian of Gulf coast.
636. M. parva (Conrad). (Fig. 1179,1.) Miocenic.
Concave portion of shoulder very narrow, and near the suture;

GASTROPODA—CONID.. 805

ribs extending beyond the lower suture; spirals fine, numerous.
Chesapeakean of Maryland, etc.

Family Conip& Adams.
CXCV b= -Congs dinn.

Whorls with a narrow shoulder and straight sides, the angle
between the two being more or less pronounced; the whorls em-
brace to the shoulder angle thus making a continuously sloping
spire, which is generally steepest in the young, and may be at right
angles to the axis; forward, the tapering of the shell is a regular
one, producing the conical form; aperture long, narrow, with an-
terior and posterior canaliculation; outer lip sharp. Cretacic—
Recent.

637. C. planiceps. (Fig. 1182.) Oligocenic.

Fic. 1182. Conus planiceps, summit and apertural Fic. 1183. Conus diluvianus,
views, young shell, 2.3. (After Dall.) 24. (After Dall. )

Spire low, conical, with papillose apex; shoulder surfaces gently
concave with a strong revolving spiral near the suture.
Vicksburgian of Florida; Chipolan beds of Gulf States.

638. C. diluvianus Green. (Fig. 1183.) Miocenic.
Spire steep, slightly terraced in the young from failure of the
whorls to embrace freely to the angle; surface faintly grooved just
below the suture, and concave above the angle; base of columella
slightly twisted inwards.
Chesapeakean of Atlantic coast.

806 NORTH AMERICAN INDEX FOSSILS.

OPISTHOBRANCHIA.
Family Act#onipa@ d’Orbigny.
CXCVII. TornatTeELL#a Conrad.

Shells with short, thick spire of rounded whorls, embracing
half way or more; aperture with both anterior and posterior notch.
Columella with two plications near the front and outer lip thick
and crenulated near the margin. Surface strongly spiraled.
Jurassic—Miocenic. .

639. T. lata Conrad. Eocenic.

Aperture more than half the length of the entire shell; colu-
mellar plications distant; spirals rounded and close together.

Eocenic of Shark River, New Jersey, and of Alabama.

640. T. bella Conrad. (Fig. 1185, a.) | Eocenic.

Less ventricose than preceding; sutures less pronounced; inter-
spiral depressions punctate.

EKocenic (Pamunkey) of Maryland and Virginia; Midwayan
and Chickasawan of Gulf region.

CXCVIII. Actzon Montford.

Shell with sinistral protoconch differing from Tornatellea
chiefly in the deeper sutures and consequently

. more pronounced whorls of the spire and in
having only one plication on the columella.
Cretacic—Recent.

Fic. 1184. Acteon :
attenuatus, view of the 641. A. attenuatus (M. and H.) . (Fig. r 184.)
type and surface en- Cretacic.
ee See eter nek ) Small, whorls elongate, slightly convex;
suture scarcely depressed but distinct; surface with spirals and
faint growth lines.

Pierre of Yellowstone River and Canada.
642. A. shilohensis Whitfield. (Fig. 1185, D.) Miocenic.

Spire appearing almost steplike from impressed sutures, rather
short; body whorl ventricose with narrow, long aperture; spirals
alternating, obsolete above the middle of whorl; plication pro-
nounced.

Shiloh marls of New Jersey; Chesapeakean of Maryland.

GASTROPODA—ACT ZONIDA:—RINGICULIDZ. 807

643. A. ovoides Conrad. (Fig. 1185, c.) Miocenic.
Differs from A. shilohensis in its straighter sides, proportion-

Fic. 1185.
ately higher whorl, and stronger subsutural shelf; spirals alter-

nating over entire shell.
Chesapeakean of Atlantic coast.

CXCIX. Actzonina d’Orbigny.
Shell elongately spired, with large

Shell large ; body whorl about three
fourths of entire length of the shell.

body whorl, becoming narrower to- \
wards the base; columella without f |

folds; outer lip sharp. Carbonic— / i"
Recent. / /

644. A.californica Gabb. (Fig. 1186.) | feo

Comanchic. | | a

\

Surface smooth; inner lip with basal ah
Z é }
callus. fi j
e ° \ f
Horsetown beds of California. MI /
Eee j
| /
: ‘ 4 V6
Family RINGICULID. eh ere
oc. CINULIA Gray. Fic. 1186. Actwonina califor-

Globose shells with short spire and 7” Mt: size. (After Gab. )

inflated body whorl; outer lip reflected, thickened; columella with

numerous folds; surface spirally grooved or punctate. Comanchic—

Cretacic. ;

645. C. mathewsoni Gabb. (Fig. 1187.) Comanchic.
Shell of four and a half whorls, the body whorl expanded;

808 NORTH AMERICAN INDEX FOSSILS.

outer lip thick and extended; surface with uniform fine spirals,
slightly crenulated; columellar lip thick with three narrow, equal
and prominent folds.

Horsetown of California, etc.

646. C. (Ringinella) polita Gabb. (Fig. 1188.) Comanchice.
Spires higher, whorls rounder, and sutures more impressed than

Fic. 1187. Cinulia matthewsoni, with Fic. 1188. Cinula ( Ringinella)
enlargement of surface. (After Gabb.) polita, enlarged. (After Gabb. )

in preceding; outer lip scarcely thickened, not extended; columella
without callus and with two unequal columellar teeth. Surface
with spirals.
Horsetown of California, etc. |
647. C. obliqua Gabb. (Fig. 1180.) Cretacic:
More globular than C. mathewsom, spire shorter, almost covered ;
body whorl large; outer and inner lips strongly thickened, the latter

Fic. 1189. Ctnulia obligua. Fic, 1190. Ringicula dal/i, much
(After Gabb. ) enlarged. (Md. Survey.)

with one large columellar fold and slight intumescence; surface
with spirals; interspiral space with crossbars.
Upper Cretacic beds of Pacific coast and Canada.

CCI. Rinercuta Deshayes.

Thick-shelled, with mamillose protoconch, short spire, large
body whorl and outer lip with reflected and greatly thickened

——~ ——"

GASTROPODA—AKERATIDA—BULLIDZ. 809

margin; columella with callus and two to four plice. Cretacic-
Recent.
648. R. dalli Clark. (Fig. 1190.) Eocenic.
Minute, five-whorled ; suture moderately impressed; surface with
regular close-set spirals; outer lip thick, ornamented within; colu-
mella with thick callus and two plice.
Pamunkey formation of Maryland and Virginia.

Family AKERATIDZ Pilsbry.
CCII. Haminea Leach.
Thin and brittle shells with concealed spire, oval in contour;
surface mostly with spirals. Cretacic—-Recent.
649. H. subcylindrica M. and H. (Fig. 11091.) Cretacic.
Subcylindrical, large for the genus (about one inch long) ; very

Fic. 1191. Haminea subcylin- Fic. 1192. MHaminea occidentalis, two in-
drica. (After Meek.) ternal molds. (After Meek. )

thin; summit with slight pit over apex; lip extended below.
Pierre of upper Missouri and Black Hills.
650. H. occidentalis (M. and H.). (Fig. 1192.) Cretacic.
Smaller and less cylindrical than preceding ; widest below middle ;
upper end obliquely truncated, with minute, central pit.
Pierre of Yellowstone, near Platte River, and in the Saskatche-
wan region of Canada.

Family Butiip# Pilsbry.
CCIII. Butta Klein.

Smooth, involute shells with sunken spire and inflated body
whorl; aperture rounded at both ends; outer lip sharp. Juras-
sic (?)—Recent.

651. B. macrostoma Gabb. Cretacic.

Subglobular, with two or three volutions; aperture very broad,

810 NORTH AMERICAN INDEX FOSSILS.

broadly rounded in front, narrowly so posteriorly ; surface smooth
except for lines of growth.
Ripleyan of New Jersey, Alabama and Mississippi.

Family ToRNATINIDA Fischer.
CCIV. VotvuLta Adams.

Cylindrical with concealed spire; long, narrow aperture, pointed
above, rounded below. Eocenic—Recent.

652. V. iota (Conrad). (Fig. 1193, 4, db.) Miocenic.

Fic. 1193. a@, Volvula iota marylandica, b, V. tota diminuta ; c, Cylichna calvert-
ensis. (Md, Survey. )

Minute ; a few impressed spirals near each end, aperture narrow-
est at center; in var. marylandica Martin, apertural end is strongly
pointed above, shell narrowing towards each end; variety diminuta
Martin is more cylindrical, the upper end less pointed, base of
aperture broad; var. calverta Martin has a proportionally greater
diameter than diminuta, and variety patusentia Martin is wider
below than above.

Chesapeakean of Atlantic coast.

Family SCAPHANDRIDZ.
CGV, CyLicHna ‘Loven;
Like the preceding, but spire deeply sunken leaving apical per-
foration; columella with plications, often umbilicated. Triassic—
Recent.

653. C. costata Gabb. | Cretacias
Rather large, with aperture widening towards base; whorls more
nearly cylindrical than.in the next species; a single fold near the
base of the columellar lip; surface with broad spirals.
Nanaimo of Vancouver and northwestern United States.

GASTROPODA—SIPHONARIIDE. SII

654. C. scitula M. and H. (Fig. 1194.) Cretacic.
Oval, widest in the middle, summit truncated with large depres-

sion; aperture narrow; a small, indistinct fold near the base of

the inner lip; surface with spirals cancellated by growth lines.
Upper Cretacic of Nebraska, South Dakota and Colorado.

655. C. galba Conrad. : Eocenic.
Cylindrical except for slight contraction near the middle; pro-

Fic. 1194. Cylichna scitula, XK 3. (After Meek. )

portionally larger and more slender than the other species; inner

lip reflected at base; obsolete spirals near anterior (basal) end.
Claibornian of Alabama.

656. C. calvertensis Martin. (Fig. 1193, c.) Miocenic.
Minute; apical end with sunken spire nearly flat.
Chesapeakean of Maryland, etc.

PULMONATA..
(Air-breathing Snails.)

Family SIPHONARIID Gray.
CCVI. HeErRcyNELLA Keyser.

Non-spiral, more or less cap- or bowl-shaped, unsymmetrical,
somewhat patelliform shells ; often truncated at one end and usually
with an umbonal angulation. Siluric—Devonic.

657. H. canadensis Grabau. Siluric.

Beak curved towards truncated end, which is asymmetrical ;
angulation regularly curved.

Upper Monroe of Canada.

CCVII. Awntsomyon Meek and Hayden.
Shell patelliform with oval or circular (rarely ovoid) aperture,
centren, or between center and anterior end; beak pointed, more
or less strongly recurved, but not spiral, generally broken away.

812 NORTH AMERICAN INDEX FOSSILS:

Muscle scar horseshoe-shaped, open in front, in the form of a

strong band on the left and a weak or broken line on the right
(see Figs. 1195 and 1196, c). Surface smooth, sometimes with a

FIG. 1195. Anisomyon alveolus, top and side view. | {After Meek.)

few coarse plications, more rarely finely striate. Jurassic—Cretacic.
658. A. meeki Gabb. Comanchic—Cretacic.
Elliptical, apex nearly centren, strongly pointed and curved, sur-
face flat, with faint, concentric undulations.
Horsetown of California; Nanaimo of Vancouver.
659. A. centrale Meek. Cretacit:
Broader than the preceding, more nearly circular; slopes, except
anterior one, nearly straight. Surface with fine radiating strize
and a few, coarse, radiating grooves.

Colorado formation of New Mexico and Colorado; also in west-
ern Canada.
660. A. alveolus (M.and H.). (Fig. 1195.) . . Cretaeie

x 04

Fic. 1196. Axnisomyon patelliformis,; a, 6, side and front view of a specimen; ¢,
top view of the type specimen. (After Meek. )

Elliptical, beak excentric; surface slopes very gently convex.
Pierre of Yellowstone, Black Hills and Canada.

661. A. patelliformis Meek and Hayden. (Figs. 1196-1197.)

Cretacic.

Subovate, broadest posteriorly, high, with beak rather sharp,
slopes irregularly convex.

Pierre of Nebraska, Yellowstone and Black Hills.

GASTROPODA—SIPHONARIIDZ. 813

662. A. subovatus M. and H. (Fig. 11098.) Cretacic.
Somewhat more elongate than preceding; sides somewhat par-

Fic. 1197. Anzisomyon patel- Fic. 1198. Anisomyon subovatus. (After Meek. )
liformis var. (After Meek.)

allel; beak more anterior; apical angle larger, slopes gently convex.
Pierre of Yellowstone River and of Black Hills.

663. A. sexsulcatus (M. and H.). (Fig. 1199.) Cretacic.

ase
powcr mm

Fic. 1199. Anisomyon sexsulcatus. (After Meek.)

Large; beak in anterior third; surface with six radiating grooves.
Pierre of Yellowstone River and of Colorado.
664. A. borealis (Morton). (Figs. 1200-1201.) Cretacic.
Very large; beak excentric, sometimes almost anterior; a regular
rounded fold from beak to posterior end.

c
ABs

Fic. 1200. 4, ¢, Anisomyon dorealis, side and anterior view of Fig. 1201, a. (After
Meek. )

814 NORTH AMERICAN INDEX FOSSILS.

Pierre of New Mexico, Colorado, Black Hills, etc.
665. A. shumardi M.& H. (Fig. 1202.) Cretacic.

a

oO a wpa

Fic. 1201. a, Antsomyon borealis, view FIG, 1202. Antsomyon shumardt.
from above. (After Meek. ) (After Meek. )

Somewhat smaller and more elongate than preceding, with beak
nearer the center.
Pierre of Missouri River.

Family AURICULID# Blainville.
CCVIII. Mertampus Montfort.

Shell ovate-conical, with short, obtuse spire and entire, narrow,
elongate aperture. Columellar lip with several plications; outer
lip sharp, lirate within. Surface smooth. Jurassic (?)—Recent.
666. M. olivaceus Carpenter. Pliocenic—Recent.

Spire conical, barely elevated, of 4-5 flat whorls, slightly angu-
lated below the shoulder. Columella and inner lip with one strong
and several weaker plications; length, 12 mm.

Pliocenic—Recent in California.

CCIX. RuyrorpHorus Meek.

Like Melampus but with shoulder bearing small, rib-like crenu-
lations. Columella with two plications; outer lip smooth within.
Cretacic.

667. R. meeki White. ~ (Fig. 1203, d.) Cretacig:

Narrower and more slender than R. priscus with whorls rounded ;
aperture wider anteriorly.

GASTROPODA—AURICULIDA:—PHYSIDZ.. 815

Bear River formation of Wyoming.
668. R. priscus Meek. (Fig.1203,e.) ° Cretacic.
Obovate, about once and a half as long as wide; shoulder some-
what pronounced and slightly angulated.
Bear River formation of Utah and Wyoming.

CCX. > ALEXI« . Leach.

Differs from Melampus in its higher spire of round whorls em-
bracing to above the ambitus, the absence of a shoulder, and in
evoid aperture. Protoconch erect. Cretacic—Recent.

669. A. antiqua (Meek). (Fig. 1203, a-c.) Cretacic.

Fic. 1203. a-c, Alexia antigua, with enlargement; d, Rhytophorus meehki,; e, R.
priscus; f, g, Limnea altivuncula; h, L. consortis; i, L. nitidula; 7, k, L. tenut-
costata; 1, L. meeki; m, L. shumardi, (After White, U. S. G. S.)

Smooth, with whorls gently convex and four columellar plica-
tions, the median one strong.
Colorado formation of Coalville, Utah.

Family Puysipz Dall.
CCXI. Puysa Drap.
Shell thin, reversed (sinistral) ; aperture large; columella twisted
or simple; surface smooth. Jurassic-Recent (fresh-water).

670. P. carltoni Meek. (Fig. 1205, a.) Cretacic.

Of moderate size, last whorl with pronounced shoulder.
Belly River beds of Utah.

816 NORTH \AMERICAN INDEX FOSSILS.

671. P. copei White. (Fig. 1205, b,c.) Cretacic.
Large, elongate; spire small; body whorl relatively slender.
Upper Cretacic (Judith River beds) of Upper Missouri River

region of Montana, and the Bow and Belly River regions of

Canada.

672. P. felix White. Cretacic.
Large; body whorl strongly shouldered;

sides straight and vertical; growth lamelle

often with serrate edges.
Laramie of Colorado.
673. P. bridgerensis Meek. (Fig. 1205, e.)
Eocenic.
Smaller than preceding, with higher spire
and less rounded whorls.
Bridger beds of southern Wyoming.
674. P. pleromatis White. (Fig. 1205, d.)
Eocenic.
Shorter and stouter than P. copei, with
Fig. “1204-0 faysa, aperture wider-and shorter.
Sri sche i asad Wahsatch group of southern Wyoming,
Colorado and Utah.

675. P. meigsii Dall. (Fig. 1204.) Pliocenic.
Spire higher and of more volutions than in P. cope; lip much

prolonged anteriorly.
Caloosahatchie marls of Florida.

Family Limna1p#@ Brod.
CCXIT. Limnaa Lamarck.

Shell very thin, translucent, with small acute spire and large
body whorl; aperture wide, with sharp outer lip. Jurassic—Recent};
(fresh-water ).

676. L. altivuncula White. (Fig. 1203, f,g.) Jurassic.

Small, slender, embracing part way to middle only; aperture
somewhat drawn out anteriorly. 7

Morrison formation near Canyon City, Colorado.

677. L. consortis White. (Fig. 1203, h.) Jurassic. —

Somewhat larger than preceding ; whorls ventricose ; spire short;
suture deep; nearly rectangular depression between the whorls.

With the preceding.

GASTROPODA—LIMN ZIDZ. ei 7

678. L. (Lymnophysa) nitidula (Meek). (Fig. 1203,7.) Cretacic.
Of medium size, high-spired; whorls rounded; sutures deep;
spire as long as or longer than aperture, rather thick-set in aspect.
Bear River formation of Wyoming.
679. L. (Pleurolymnza) tenuicostata M.andH. (Fig. 1203, 7, k.)
Eocenic.
Very slender, anterior end of lip extended, surface with sharp,
narrow, flexuous coste.
Fort Union beds of Upper Missouri country.
680. L. meeki Evans & Shumard. (Fig. 1203, /.) Oligocenic.
Of medium size; spire of about four rapidly tapering, rounded
whorls; body whorl round, large, sutures moderately impressed.
White River group of Upper Missouri region.
681. L. shumardi Meek & Hayden. (Fig. 1203, m.) Oligocenic.
Body whorl somewhat shorter than in preceding; aperture pro-
portionally somewhat broader.
White River group of Upper Missouri region.

CCXIII. Vorricirex Meek.

Heliciform or Planorbiform shells of ventricose aspect, open, but
small umbilicus and somewhat angulated whorls, one of the angu-
lations bounding the umbilicus; strong coste of growth, especially
in the young. Miocenic. _ ,
682. V. binneyi Meek. (Fig. 1205, j, g.) Miocenic.

Umbilicus large; spire flat; surface with regular variciform
growth lines.

Miocenic of Kawsoh Mountains, Nevada.

683. V. tryoni Meek. (Fig. 1205, h-/.) Miocenic.

Smaller than preceding, surface ornamentation fainter; umbili-
cus small.

Occurs with the preceding.

CCXIV. PLanoreis Guettard.
Coiled typically in a discoid manner, the entire spire below the
body whorl, but not symmetrically involute; aperture oval, varying
to crescent-shaped and with a sharp outer margin. Lias—Recent.

818 NORE AMERICAN INDEX “FOSSILS.

if

If YK)
My fyftii

q

FIG. 1205. a, Physa caritoni; b,c, P. cope; d, P. pleromatis ; Ae bridgerensis ;

hi &; Carinifex binneyi, h-z, C. tryont.

684. P. veternus M. and H. (Fig. 1206, a-f.) Jurassic.
Small; whorls numerous, regularly enlarging, coiled nearly in

a single plane. :
Non-marine Jurassic -of Colorado, Dakota (Black Hills) and

British Columbia.

685. P. convolutus M. and H. (Fig. 1206, 9-7.) Cretacic.
Larger than preceding, with less symmetrical disposition of

whorls.

Judith River beds of upper Missouri River region.
686. P. (Bathyomphalus) amplexus (M.andH.). (Fig. 1206, j,k.)
Cretacic.
Numerous whorls, very gradually enlarging, deep umbilicus,
with shell slightly angulated around it.
Judith River beds of Nebraska.

687. P. (Bathyomphalus) planoconvexus (M. and H.). (Fig.
1206, 1.) Eocenic.
Spire flat, whorls depressed above, angulated externally and

around the umbilicus; umbilicus very large.

GASTROPODA—LIMNALIDZ.. 819

Fort Union beds of upper Missouri River region.
688. P. utahensis Meek. (Fig. 1206, m-o.) Eocenic.
Large and much compressed vertically; aperture transverse;

outer margin subangular; variety spectabilis (Fig. 1206, p) has
the outer margin more rounded.

Bridger group of southern Wyoming.
689. P. cirratus White. (Fig. 1206, g-s.) Eocenic.

5

Fic. 1206. a-f/, Planorots veternus ; small (a-c) and larger form; g—z, P. convo-
lutus; 7, k, P. (Bathyomphalus) amplexus; 1, P. (B.) planiconvexus ; m-o, P.
utahensis, P. var, spectabilis; g-s, P. cirratus; ¢t-v, P. vetustus; w, x, P. leidyi;
woage eenata, ~( All after White, U. S. G. S., III.)

Small, of numerous, very slightly increasing whorls coiling
nearly in a plane; upper and lower aspect much the same.
Green River of southern Wyoming.

690. P. vetustus Meek & Hayden. (Fig. 1206, tw.) Oligocenic.
Smaller than 7. utahensis and the outer side of last whorls more

sharply angulated; spire less depressed.
White River beds of Dakota.

8 20 NORTH AMERICAN INDEX FOSSILS.

691. P. leidyi Meek and Hayden. (Fig. 1206, w, x.) Oligocenic.
Stout and thick with much embracing whorls, small umbilicus
and flat spire.
White River group of Dakota.
692. P. lunatus Conrad. (Fig. 1206, y, 2.) Miocenic?
Similar to P. leidyi, but more nearly symmetrical in plane of
coiling.
Miocenic(?) of Oregon.
693. P. conanti Dall. (Fig. 1207, a, b.) Pliocenic.

- \Vyaae

Fic. 1207. a, 6 (left and upper middle), Planorbis conanti; c, d (right and lower
middle), Planorbis disstont, XK 1.3. (After Dall.)

Spire sunken; whorls embracing to moderate extent, upper sur-
face with angulation below the suture; height and width of aper-
ture nearly the same.

Caloosahatchie marls of Florida, especially in Planorbis bed.

694. P. disstoni Dall. (Fig. 1207, c, d.) Pliocenic.
Angulation more distant from suture and more pronounced;

shell proportionally higher, aperture higher than wide.
Caloosahatchie marls of Florida.

Family Pupab@ Gray.
CEXV 1 Pures igamarck.

Cylindrical, generally narrowing towards both ends, with suture
scarcely depressed and with semicircular aperture which is com-
monly constricted by teeth on columella and on the inner and outer
lip. Carbonic—Recent. |
695. P. vermilionensis Bradley. (Fig. 1208, f, 9.) Carbonic.

Few rounded, gradually enlarging whorls, with deep sutures;
aperture with one basal and one strong columellar tooth.

Coal measures of Indiana.

GASTROPODA—PUPADEZ. 821

696. P. arenula White. (Fig. 1209, a, D.) Eocenic.
Small, short and thick, with much contracted aperture.
Green River beds of southern Wyoming.

CCXVI. ANTHRACOPUPA Whitfield.

Minute pupiform shells with few volutions, imperforate axis
and nearly vertical aperture; peristome thickened, with inner lip
forming a nearly transverse callus, bearing teeth; inner margin of
lip also with teeth and a nearly circular notch. Carbonic.

697. A. ohicensis Whitfield. (Fig. 1208, a—c.) Carbonic.

Fic. 1208. a-—c, Anthrocopupa ohioensis ; d, e, Dendropupa vetusta ; f, g, D. vermil-
tonensis; h, 1, Archeozonites priscus. (All after White; 3d Ann. U.S. G. S.)

Small, with 3 or 4 strongly embracing whorls, reflected thick-
ened lip, bearing a tooth antero-laterally, and inner lip callous, also

bearing a single tooth. Surface with fine growth lines; length
about 3.3 mm.

Upper Coal measures of Ohio.

CCXVII. DENpRopuPA Dawson.
Like Pupa, but with aperture toothless. Carbonic (fresh-water ).
698. D. vetusta Dawson. (Fig. 1208, d, e.) Carbonic.
Long, subcylindrical, of numerous, rather irregular whorls,

slightly convex, with moderately impressed suture; aperture pro-
duced with reflexed lower lip.

Coal measures of Nova Scotia (Joggins beds).

822 NORTH AMERICAN INDEX FOSSILS.

Family ZoNITIDZ.
CCXVIII. Arcu#ozonites Sandberger.

Thick-shelled, globose, Helix-like shells, with rather high spire,
and deep umbilicus; outer lip sharp; surface smooth. Carbonic—
Miocenic.
699. A. priscus Dawson. (Fig. 1208, h, 1.) Carbonic.

Small; spire rather low and broad; whorls compound and
rounded; surface with fine growth lines.

Coal measures of Nova Scotia (Joggins).

Family Heticip@ Keferstein.
COXIXS - Beni Linne:

Generally thin-shelled, of several whorls, ‘more or less regularly

increasing, flat- or low-spired (obtuse) ; aperture incomplete, with
disconnected margin; umbilicus present or absent; lip simple or
with terminal varix. Many subgenera are recognized. More than
3,400 species. ‘Terrestrial. Eocenic—Recent.
700. H. leidyi Hall and Meek. (Fig. 12009, c,d.) Miocenic.
High-spired; apical angle approaching 90°. Many whorled;
body whorl subglobose. ,
701. H. diespiter Dall. Pliocenic.
Many-whorled, low-spired ; base horizontally flattened ; umbilicus
small, partly covered; oval aperture with pronounced expansion,
where lip joins body whorl; a terminal deflection or varix.
Silex bed of Ballast Point, Florida.
702. H. crusta Dall. Pliocenic.
Smaller with umbilicus less covered, aperture smaller and
less oval.
Associated with preceding.
703. H. (Polygyra) albolabris (Say). Pleistocenic—Holocenic.
Larger than preceding, non-umbilicate; spire low, finely striate ;
lip sharply reflected; strong umbilical covering. 3
Loess of southern Mississippi Valley; living in eastern North
America.
704. H. (Pyramidula) alternata (Say). Pleistocenic—Holocenic.
Low-spired, deeply and broadly umbilicate, with 5 or more
whorls, with sharp growth lamallz above, smooth below, last one

»

GASTROPODA—HELICIDZ—HETEROPODA. 823

sometimes carinated; with broken color lines; oblique aperture
with a sharp lip; suture slightly impressed.
Loess of Mississippi Valley; living in eastern North America to
Labrador.
HETEROPODA.

CCXX. PELAGIELLA Matthew.

Small thin shells, coiled nearly or quite in a single plane of few
whorls ; compressed and with wide entire aperture ; probably pelagic .
like modern Atlanta to which it seems most nearly related.
Cambric.

705. P. atlantoides Matthew. (Fig. 1210.) Cambric.

Fic. 1209. a, 6, Pupaarenula; c, a, Fic. 1210. FPelagiella atlantoi
Helix leidyi, (After White, U.S. G.S., des. (After Matthew. )
III. )

Rapidly enlarging, one side less convex than other, making a
slightly asymmetric coil; margin with somewhat constricted rim.
Protolenus bed at base of Middle Cambric, New Brunswick.

PDE OOP GENERA.

This includes likewise names of subgenera, families, orders, classes and
All numbers refer to pages.

phyla.

VOLUME I.

as synonyms are printed in ttalics.

Acanthonema, 691
Acanthopecten, 492
Acervularia, 68
Aclisina, 695
Acrogenia, 162
Acrophyllum, 60
Acrothele, 200
Acrotreta, 199
Actzon, 806
Acteonide, 806
Acteonina, 807
Actinodesma, 423
Actinopteria, 447
Actinostroma, 39
Actinotrypa, 164
Actinozoa, 47
Acus, 799
Adeonellopsis, 170
Adeorbiide, 704
Adeorbis, 705
ZEnona, 568
Akeratide, 809
Alexia, 815
Allonema, 118
Allonychia, 432
Allorisma, 523
Alveolites, 91
Amauropsis, 721
Amboceelia, 342
Ambonychia, 429
Amnigenia, 476
Amphigenia, 279
Amplexopora, 130
Amplexus, 58
Ampullina, 718
Amusium, 507
Anastrophia, 272
Anatimya, 531
Anchura, 750
Ancillopsis, 797
Anisomyon, 811
Anodonta, 480
Anolotichia, 123
Anomalina, 11
Anomalodesmacea, 522
Anomalodonta, 430
Anomia, 509
Anomphalus, 671
Anoplotheca, 349

Antalis, 579
Anthozoa, 47
Anthracomya, 478
Anthracoptera, 477
Anthracopupa, 821
Aporrhaide, 750
Aporrhais, 753
Arca, 417
Archezozonites, 822
Archanodon, 477
Archimedes, 147
Archinacella, 605
Arcopagia, 562
Arctica, 537
Aristerella, 518
Arthroclema, 152
Arthropora, 156
Arthrostylus, 152
Ascodictyon, 117
Aspidopora, 130
Astarte, 539
Astartella, 536
Astreospongia, 17
Astrohelia, 104
Astylospongia, 14
Astyris, 761
Atactoporella, 127
Athyris, 352
Atremata, 188
Atrypa, 309
Aucella, 456
Aulacophyllum, 59
Aulopora, 78
Auriculide, 814
Aurinia, 794
Avicula, 445, 447
Aviculopecten, 486
Aviculopinna, 435
Axinea, 418
Axonolipa, 27

Bactropora, 155
Bakewellia, 438
Balanophyllia, 104
Barbarofusus, 775, 776
Barbatia, 417
Barrandella, 276
Bathyomphalus, 818
Batostoma, 136

824

Names of genera and subgenera regarded

' Botryllopora, 127

Batostomella, 133
Beatricea, 46
Bellerophon, 618
Bellerophontide, 609
Bembexia, 647
Berenicea, 119
Biflustra, 168
Billingsella, 210
Bilobites, 259
Bittium, 747
Blothrophyllum, 60

-Brachiopoda, .170
Brachiospongia, 17
Breviarca, 407
Bryozoa, 107
Bucania, 613
Bucaniella, 612
Bucanopsis, 622
Buccinofusus, 762
Buccinide, 761
Buccinum, 761
Buchiola, 392
Bulbifusus, 783
Bulimorpha, 699
Bulla, 809
Bullide, 809
Buskopora, 126
Byssonychia, 431
Bythopora, 133
Bythotrypa, 123

Cadulus, 581
Calaurops, 662
Calceola, 77
Calcisphera, 11
Calliostoma, 703
Callonema, 691
Callopora, 139
Calyptrea, 713
Calyptraphorus, 752°
Camarella, 271
Camarophoria, 280
Camaroteechia, 283
Campeloma, 727
Campophyllum, 67
Camptonectes, 505
Cancellaria, 797
Cancellariide, 797

Caprina, 549
Capulide, 712
Capulus, 712
Cardiola, 391
Cardiomorpha, 386
Cardiopsis, 386
Cardium, 558
Caricella, 794
Carinaropsis, 626
Cassidaria, 759
Cassidide, 759
Cavaria, 167
Centronella, 299
Ceramophylla, 123
Ceramopora, 121
Ceramoporella, 121
Ceratopora, 79
Ceriopora, 168
Cerithiide, 747
Cerithiopsis, 749
Cerithium, 748
Chenomya, 387
Chama, 546
Chemnitzia, 709
Chicoreus, 785
Chilostomata, 168
Chilotrypa, 125
Chlamys, 500
Chonetes, 233
Chonopectus, 239
Chonophyllum, 62
Chonostegites, 90
Chonostrophia, 238
Chrysallida, 710
Cimitaria, 528
Cinulia, 807
Cladophyllia, 100
Cladopora, 92
Clasmopora, 98
Clathrodictyon, 40
Clathropora, 156
Clathrospira, 644
Clavilithes, 780
Cleidophorus, 397
Clementia, 562
Climacograptus, 31
Clinopistha, 376
Clionychia, 434
Cliothyris, 353
Clitambonites, 270
Clonograptus, 27
Clorinda, 276
Ceelenterata, 20
Celidium, 652
Celocaulus, 652
Ceeloclema, 122
Ceeloconus, 154
Ceelospira, 350
Cceenograptus, 28
Ceenostroma, 44
Colpomya, 516
Columbella, 761

INDEX OF GENERA. 825

Columbellide, 761
Columnaria, 71
Conchidium, 273
Conidz, 805
Conocardium, 436
Conomitra, 790
Conradella, 617
Constellaria, 135
Conus, 805
Coralliochama, 551
Corals, 47
Corbicula, 543
Corbula;: 573
Cornellites, 421
Coscinella, 158
Coscinium, 161
Cranena, 302
Crania, 206
Craniella, 208
Craspedophyllum, 75
Crassatellites, 540
Crenella, 522
Crenipecten, 495
Crepidula, 713
Crepipora, 122
Cristellaria, 9
Crucibulum, 714
Cryptonatica, 719
Cryptonella, 301
Cryptorhytis, 772
Cryptostomata, 140
Cryptozoon, 46
Ctenodonta, 393
Ctenostomata, 116
Cucullea, 405
Cumingia, 569
Cuneamya, 378
Cuspidaria, 532
Cyathophyllum, 65
Cyclonema, 668
Cyclora, 673
Cyclospira, 309
Cyclostomata, 118, 166
Cylichna, 810
Cymbophora, 571
Cymella, 531
Cynodonta, 782
Cyprea, 758
Cypreide, 758
Cypricardella, 534
Cypricardinia, 535
Cyprimeria, 562
Cyprina, 537
Cyrtia, 314
Cyrtina, 312
Cyrtodonta, 409
Cyrtolites, 609
Cystiphyllum, 62
Cystodictya, 160

Dactylidia, 796
Dalmanella, 259

Dekayella, 132
Dekayia, 133
Delthyris, 319, 332
Dendrograptus, 26
Dendroidea, 24
Dendropupa, 821
Dentaliide, 578
Dentalium, 578
Derbya, 231
Desmograptus, 26
Diamesopora, 165
Diaphorostoma, 679
Diastoporina, 119
Dicellograptus, 32
Dicellomus, 189
Dichograptus, 28
Dichotrypa, 161
Dicranograptus, 32
Dictyonella, 209
Dictyonema, 24
Dictyospongia, 14
Didymograptus, 30
Dielasma, 302
Dinobolus, 190
Dinorthis, 252
Diplodonta, 557
Diplograptus, 33
Diplophyllum, 73
Diploporaria, 151
Discinisca, 205
Discosparsa, 167
Discotrochus, 102
Doliide, 760
Dosiniopsis, 565
Drillia, 803
Drymotrypa, 141
Duncanella, 76

Eatonia, 296
Eccyliomphalus, 662
Eccyliopterus, 658
Ecphora, 787
Edmondia, 388
Emarginula, 707
Endodesma, 527
Endopachus, 106
Endoptygma, 723
Endothyra, 11
Enteletes, 269
Enterolasma, 56
Entolium, 506
Eotomaria, 642
Erato, 759
Eridophyllum, 71
Eridotrypa, 134
Escharopora, 156
Etea, 542
Euchondria, 492
Euconia, 642
Euconospira, 647
Eulima, 709
Eulimide, 709

826

Eumetria, 346
Eunella, 303
Eunema, 670
Euomphalide, 653
Euomphalopteris, 629
Euomphalus, 659
Euphemus, 621
Eupsammia, 105
Eurymya, 517
Euryzone, 644
Eutrochus, 703
Evactinopora, 164.
Raia, 7977
Exogyra, 472

Falsifusus, 774
Fasciolaria, 772
Favistella, 71
Favosites, 84
Fenestella, 142
Fenestralia, 150
Fenestrapora, 145
Fibula, 748
Ficus, 760
Filifascigera, 166
Fissurella, 708
Fissurellide, 707
Fissuridea, 708
Fistulipora, 124
Flabellum, t1o1
Foraminifera, 8
Fordilla, 389
Fulgur, 767
Fulguride, 764
Fulguroficus, 779
Fulgurofusus, 775
Fuside, 773
Fusispira, 697
Fusoficula, 780
Fusulina, 12
Fusus, 773

Galerus, 713
Gastropoda, 582
Gervillia, 438
Gervilliopsis, 439
Gibbula, 702
Glauconia, 738
Glauconome, 151
Globigerina, 10
Glossina, 195
Glossites, 384
Glycimeris, 418
Glyptodesma, 423
Glyptopora, 163
Goniobasis, 742
Goniograptus, 29
Goniophora, 518
Grammysia, 380
Graptacme, 580
Graptolites, 21
Graptolitoidea, 27

Grypheza, 467
Grypheostrea, 465
Gypidula, 278
Gyrodes, 719
Gyroma, 646
Gyronema, 671

Hadrophyllum, 65
Halobia, 452
Halysites, 96
Haminea, 809
Hapsiphyllum, 58
Hastula, 800
Hebertella, 254
Hederella, 120
Heilprinia, 775
Helcionella, 607
Helcionopsis, 604
Helicide, 822
Helicotoma, 658
Heliolites, 97
Heliophyllum, 67
Helix, 822
Helopora, 152
Hemiphragma, 137
Hemipleurotoma, 801
Hemitrypa, 146
Hercynella, 811
Hernodia, 120
Heteropoda, 823
Heteropora, 168
Hexacoralla, 99
Hindia, 14
Hipparionyx, 232
Holopea, 676
Homeeospira, 344
Homotrypa, 128
Honeoyea, 429
Hormotoma, 648
Hormotomina, 651
Hustedia, 345
Hyattella, 348
Hydnoceras, 17
Hydrocorallines, 34
Hydrozoa, 20
Hypothyris, 294
Hypseloconus, 604
Hypsipleura, 739

Ichthyosarcolites, 551
Idiostroma, 43
Igoceras, 689
Ilionia, 379
Inoceramus, 440
Intrapora, 158
Iphidea, 201
Ischadites, 19
Ischyrodonta, 416
Isocardia, 561
Isonema, 692

Kingena, 305
Kutorgina, 209

INDEX. OF GENERA.

Labechia, 46
Lacinia, 781

Levidentalium, 578, 581
Lamellibranchiata, 361

Lathyrus, 777
Laxispira, 738
Leda, 400
Legumen, 571
Leiopteria, 424
Leiorhynchus, 289
Lepetopsis, 609
Leptena, 225
Leptobolus, 194
Leptoceelia, 351
Leptodesma, 425
Leptosolen, 570

Leptostrophia, 215, 217

Levifusus, 771
Lichenalia, 125
Lichenalia, 165
Lima, 509
Limnea, 816
Limnzide, 816
Limoptera, 422
Linearia, 567
Lingula, 194
Lingulasma, 198
Lingulella, 192
Lingulepis, 193
Lingulodiscina, 202
Linnarssonia, 200
Liopistha, 531 _
Liospira, 640
Lirofusus, 778
Lispodesthes, 754
Lithostrotion, 76
Loculipora, 146
Loganograptus, 28

‘Lophophyllum, 76

Lophospira, 631
Loxonema, 692
Loxonematide, 691
Loxopteria, 426
Lucina, 555
Lunatia, 717
Lunulicardium, 427
Lyellia, 96
Lymnophysa, 817
Lyriopecten, 494
Lyrodesma, 481
Lyropecten, 502
Lyropora, 150

Maclurea, 664
Maclurina, 666
Maclurites, 664
Mactra, 571
Mangilia, 804
Margarita, 704
Marginella, 788
Marginellide, 788
Martinia, 340

Mazzalina, 783
Meekella, 232
Meekopora, 126
Meekospira, 698
Megalomus, 410
Megambonia, 410
Melampus, 814
Melania, 740
Melaniide, 739
Melanopsis, 741
Membranipora, 169
Meretrix, 563

Pe Meristella, 355

Meristina, 351
Mesalia, 729, 731
Mesotrypa, 130
Metaplasia, 343
Michelinia, 89
Microcyclus, 65
Microdon, 534
Mitoclema, 120
Mitra, 789
Mitride, 789
Modiella, 456
Modiola, 521
Modiolodon, 516
Modiolopsis, 511
Modiomorpha, 513
Mollusca, 361
Molluscoidea, 107
Monilopora, 81
Monograptus, 34
Monomerella, 190
Monopleura, 547
Monopteria, 450
Monotrypa, 137
Monotrypella, 131
Monticulipora, 127
Mourlonia, 646
Murchisonia, 650
Murchisonide, 648
Murex, 785
Muricide, 784
Myalina, 453
Mytilarca, 432
Mytilus, 520

Naiadites, 477
Nassa, 763
Natica, 716
Naticide, 715
Naticopside, 673
Naticopsis, 673
Neithea, 497
Nematopora, 153
Nemodon, 404
Neotremata, 199
Neptunea, 763
Nerinea, 744
Nerineide, 744
Nerinella, 746
Nerita, 706

INDEX

Neritidez, 706
Neritopside, 705
Neritopsis, 705
Neverita, 719
Newtoniella, 749
Nicholsonella, 136
Niso, 709
Nisusia, 210
Nodosaria, 10
Nucleospira, 349
Nucula, 395
Nuculana, 400
Nuculites, 397
Nyassa, 478

Obolella, 188
Octocoralla, 96
Oculina, 103
Odontofusus, 780
Odostomia, 710
Oliva, 795
Olivella, 796
Olivide, 795
Olivula, 797
Omphalotrochus, 667
Ontaria, 391
Onychocella, 169
Ophileta, 656
Ophiletina, 657
Opis, 540
Opisthobranchia, 806
Orbiculoidea, 204
Orbitoides, 12
Orbulina, 10
Ormospira, 631
Orthaulax, 756
Orthide, 249
Orthis, 249, 250
Orthodesma, 379
Orthonema, 696
Orthonota, 377
Orthonychia, 687
Orthorhynchula, 281
Orthostrophia, 256
Orthothetes, 231
Ortonella, 412
Ostrea, 458
Owenella, 610
Oxydiscus, 616

Pachychilus, 740
Pachydictya, 159
Pachymelania, 742
Pachyphyllum, 70
Paleacmea, 606
Paleacmeide, 603
Paleanatina, 385
Paleocapulus, 686
Paleocyclus, 64
Paleoneilo, 398
Paleschara, 166
Paludina, 725

OF GENERA.

Panenka, 389
Panopea, 576
Paracardium, 392
Paracyclas, 554
Parallelodon, 403
Paranomia, 510
Parasmylia, 99
Parastrophia, 271
Parazyga, 346
Parmophorella, 606
Patinopecten, 504
Pecten, 495
Pectunculus, 418
Pelagiella, 823
Pelecypoda, 361
Peneroplis, 9
Pentagonia, 359
Pentamerella, 277
Pentamerus, 275
Peregrinella, 299
Perissolax, 767
Perissoptera, 753
Petaloconchus, 737
Petalotrypa, 131
Phacelopora, 121
Phanerotinus, 656
Phanerotrema, 638
Phenacomya, 530
Phillipsastrea, 69
Pholadella, 527
Pholadomya, 528
Pholidops, 208
Pholidostrophia, 219
Phractopora, 164
Phragmolithes, 617
Phragmostoma, 625
Phthonia, 376
Phyllodictya, 159
Phyllograptus, 29
Phylloporina, 140
Physa, 815
Physide, 815
Piestrocheilus, 773
Pinna, 435
Pinnatopora, 150
Placunopsis, 510
Planorbis, 817
Plasmopora, 98
Platyceras, 680
Platyostoma, 679
Platystrophia, 257
Platytrochus, I1o1
Plectambonites, 226
Plectorthis, 251
Plethocardia, 416
Plethomytilus, 433
Pleurocora, 99
Pleurodictyum, 89
Pleurolymneza, 817
Pleuromya, 522
Pleuronotus, 659
Pleurophorus, 533

$28

Pleurorima, 645
Pleurotoma, 800
Pleurotomariide, 627
Pleurotomide, 800
Plicatula, 508
Poleumita, 667
Polorthus, 578
Polygyra, 822
Polypora, 148
Polyzoa, 107
Porcellia, 627
Porifera, 13
Potamides, 749, 750
Prasopora, 129
Prionodesmacea, 375
Prismodictya, 15
Prismopora, 162
Proboscina, 118
Productella, 240
Productus, 243
Prothyris, 377
Protocardia, 560
Protorthis, 211
Protospirialis, 671
Protowarthia, 611
Protozoa, 7
Protremata, 209
Pseudolathyrus, 778
Pseudomonotis, 450
Psiloconcha, 386
Pteria, 445
Pterinea, 419
Pterinopecten, 492
Pterocerella, 755
Pterochenia, 428
Pteronites, 446
Ptilodictya, 155
Ptilograptus, 27
Ptilopora, 151
Ptomatis, 624
Ptychodesma, 455
Ptychomya, 542
Ptychophyllum, 62
Ptychopteria, 449
Pugnax, 295
Pugnellus, 755
Pulmonata, 811
Pupa, 820

Pupade, 820
Purpuride, 787
Pycnomphalus, 672
Pycnostylus, 61
Pyramidellide, 709
Pyramidula, 822
Pyrgulifera, 741
Pyropsis, 765
Pyrula, 760

Radiolaria, 12
Radiolites, 552
Rafinesquina, 211
Raphistoma, 627

INDEX OF GENERA.

Raphistomina, 629
Receptaculites, 18
Rensseleria, 300
Reptaria, 120
Requienia, 546
Reteporidra, 147
Reticularia, 337
Retiolites, 34
Retzia, 344
Rhinidictya, 158
Rhinoclavis, 749
Rhipidomella, 262
Rhombopora, 153
Rhombotrypa, 131
Rhopalonaria, 116
Rhynchonella, 297
Rhynchopora, 297
Rhynchospira, 344
Rhynchotrema, 281
Rhynchotreta, 282
Rhytimya, 526
Rhytophorus, 814
Rimella, 757
Ringicula, 808
Ringiculide, 807
Ringinella, 808
Rissoide, 722
Rissoina, 722
Remerella, 205
Romingeria, 79
Rostellites, 792

Saffordia, 384
Salpingostoma. 614
Sanguinolites, 376
Saxicava, 575
Scala, 710
Scalaria, 710
Scalariide, 710
Scalaripora, 163
Scalaspira, 785
Scalites, 630
Scaphandride, 810
Scaphopoda, 578
Scenella, 608
Scenidium, 270
Schizobolus, 203
Schizocrania, 202
Schizodesma, 573
Schizodus, 482
Schizolopha, 637
Schizophoria, 267
Schizoporella, 170
Schizotreta, 205
Schuchertella, 228
Seila, 749
Semele, 568
Semicoscinium, 143
Seminula, 354
Septastrza, 100
Sieberella, 278
Sigaretus, 715

Siliqua, 569
Siliquaria, 738
Siphonalia, 762
Siphonariide, 811
Siphonodentaliide, 581
Solariide, 711
Solarium, 711
Solemya, 375
Soleniscus, 699
Solenospira, 653
Solyma, 570
Spherium, 544
Spherodoma, 7o1
Sphenotus, 524
Spirifer, 315
Spiriferina, 314
Spiroraphe, 645
Sponges, 13
Staurograptus, 27
Stenochisma, 288
Stenopora, 134
Stenotheca, 607
Stereolasma, 56
Sthenorhytes, 711
Stictoporella, 157
Stictotrypa, 166
Stomatopora, 118
Straparollina, 653
Straparollus, 654
Streblotrypa, 155
Strepsidura, 770
Streptaxis, 695
Streptelasma, 54
Streptolathyrus, 777
Striatopora, 94
Stricklandinia, 274
Stromatocceerium, 46
Stromatopora, 44
Stromatoporella, 42
Stromatoporoidea, 34
Stromatotrypa, 137
Strombide, 755
Strombodes, 70
Strombus, 757
Strophalosia, 239
Stropheodonta, 212
Strophomena, 222
Strophonella, 220
Strophostylide, 676
Strophostylus, 677
Styliferina, 747
Stylodictyon, 41
Subulites, 6096
Subulitide, 696
Surcula, 800, 802, 803
Sycotypus, 769
Synaptophyllum, 73
Syncyclonema, 507
Syntrophia, 270
Syringopora, 82
Syringostroma, 44, 45
Syringothyris, 341

Tabulata, 78
Tzniopora, 161
Tancredia, 554
Tapes, 566
Teinostomata, 704
Teleodesmacea, 533
Tellina, 566
Tellinopsis, 385
Telotremata, 281
Tenea, 558
Terebride, 798
Terebratella, 306
Terebratula, 303
Terebratulina, 304
Terebra, 798
Teredo, 577
Tessarolax, 754
Tetradium, 99
Tetragraptus, 29
Tetracoralla, 54
Tetranota, 612
Textularia, 9
Thamniscus, 150
Thecia, 91
Tornatellea, 806
Tornatinide, 810
Trachydomia, 674
Trachypora, 95
Trematis, 201
Trematonotus, 615
Trematopora, 139
Trematospira, 345
Trepospira, 648
Trepostomata, 127
Triblidium, 603

Trigonarca, 407
Trigonia, 483
Trigonostoma, 798
Trimerella, 191
Trochide, 702
Trochonema, 669

Trochoturbinide, 667

Trophon, 786
Tropidoleptus, 305
Truncatulina, 11
Tudicla, 764
Tulotoma, 725
Turbinella, 781
Turbinellide, 781
Turbinolia, 102
Turbo, 676
Turbonilla, 709
Turbonopsis, 675
Turnus, 577
Turritella, 729
Turritellide, 729
Tympanotonus, 749
Typhis, 786

Uncinulus, 290
Unio, 479
Unitrypa, 145
Urosalpinx, 784

Valvata, 724
Valvatide, 724
Vanikoropsis, 715
Vanuxemia, 412
Vasum, 782
Velatella, 707

INDEX OF GENERA.

Venericardia, 544
Veniella, 538
Venus, 563
Vermetus, 737
Verneuilina, ro
Vicarya, 738
Vinella, 118
Vitulina, 351
Viviparide, 725
Viviparus, 725
Vola, 497
Voluta, 794
Volutide, 790
Volutilithes, 790
Volutomorpha, 792
Volvula, 810
Vorticifex, 817

Westonia, 193
Whiteavesia, 517
Whitella, 414
Whitfieldella, 346
Wilsonia, 293
Worthenia, 639
Worthenopora, 164

Xenophora, 723
Xenophoride, 723

Yoldia, 402

Zaphrentis, 56
Zonitide, 822
Zygospira, 307

829

i OY Ob SPECIES:

VOLUME I.

Varieties are printed as species. When a species name of adjective form is
followed by two or more genera or subgenera of differing gender, there are
placed after it the appropriate endings in the order—masculine, feminine and
neuter. All numbers refer to pages. Name of genera, subgenera and species

regarded as synonyms are, when possible, printed in italics.

abortiva, Membranipora, 169
abruptus, a,

Anchura, 751

Cadulus, 581

Uncinulus, 292
abundans, Drillia, 803
abyssina,

Gyrodes, 720

Margarita, 704
acadica,

Paleacmeza, 606

Parmophorella; 606
acaulis, Unitrypa, 146
acclinis, Diplodonta, 558
acinus, Camaroteechia, 284
acuminatus, a, um,

Lophospira, 634

Lyrodesma, 481

Spirifer, 326

Trimerella, 191
acuta, Pachydictya, 159
acuticosta, Typhis, 786
acutilirata,

Platystrophia, 258

Protowarthia, 612
acutirostris,

Cyrtina, 313

Orthonychia, 688
acutirostrum, Lunulicardium, 428
adamsii,

Cerithium, 749

Seila, 749
adjutor, Lophospira, 637
zolus,

Sanguinolites, 377

Sphenotus, 526
equi. See equi
aggregatum, Cystiphyllum, 64
ainslii, Rhynchotrema, 282
alabamensis (alabamaénsis), e,

Amusium, 508

Modiola, 522

Oliva, 796

Olivella, 796

Pecten, 508
aleformis, Crassatellites, 541
alata,

Ambonychia, 431

alata,

Anomalodonta, 431
albequus, Pleurophorus, 534
albertina, Ctenodonta, 394
albida,

Hemipleurotoma, 801

Pleurotoma, 8o1
albolabris,

Helix, 822

Polygyra, 822
aldrichi,

Corbula, 575

Strombus, 757
alexandra, Ormospira, 631
alpenensis (alpenaénsis), e,

Cyathophyllum, 66

Cyrtina, 313

Favosites, 87
alpheus, Trematonotus, 615
alsa, Rhipidomella, 264
alternatus, a,

Cancellaria, 798

Helix, 822

Pyramidula, 822

Rafinesquina, 211
alticosta, Venericardia, 545
altivuncula, Limnza, 816
altonensis, Naticopsis, 674
altus, a,

Ctenodonta, 394

Cymbophora, 572

(Cyttia, gi4

Inoceramus, 443

Modiomorpha, 514
alveata, um,

Amauropsis, 722

Grammysia, 381

Lacinia, 781

Solarium, 712
alveolata, Columnaria, 71
alveolus, Anisomyon, 812
ambigulus,

Rostellites, 794

Volutilithes, 794
americana, um,

Aviculopinna, 435

Cystiphyllum, 63

830

INDEX . OF SPECIES.

americana, um,

Liospira, 641

Lyellia, 96

Melanopsis, 741

Rhynchotreta, 283

Tancredia, 554
ammon, Straparollus, 655
ammonoides, Anomalina, 11
ampla,

Holopea, 676

Lophospira, 635

Strophonella, 222
amplectens, Monotrypa, 138
amplexus,

Bathyomphalus, 818

Planorbis, 818
amygdalina, Ambonychia, 430
angelica, Athyris, 353
anguis, Ichthyosarcolites, 551
angulatus, a,

Cimitaria, 528

Drillia, 803

Myalina, 453

Scalites, 630

angustifolius, Phyllograptus, 30

angustus, a,

Fusispira, 697

Spirifer, 330
anna, Phyllograptus, 30
anteradiata, Anatimya, 531
anthonense, Scenidium, 270
antiqua,

Alexia, 815

Holopea, 677

Monilopora, 81

Stromatopora, 44
antiquata, Owenella, 610
antrosa, Cucullea, 406
aperta, Calyptrea, 713
aphelium, Calliostoma, 703
apicalis, Turritella, 737
appressus, um,

Schizodesma, 573

Schizodus, 482
aquianus, a,

Crassatellites, 541

Lucina, 556
arata,

Cypricardinia, 535

Emarginula, 708

Pentamerella, 277

Spiroraphe, 645
arborea, Monticulipora, 127
arbuscula, Monotrypella, 131
archiaci, Craspedophyllum, 75
eremed, Saxicava, 575

arctostriata, Schuchertella, 229

arcuata,
Grammysia, 383
Meristella, 358
Productella, 242
Stropheodonta, 218

arenaria, Actinopteria, 448
arenosus, Spirifer, 322
arenula, Pupa, 821
areyi, Eotomaria, 643
argentaria, Anomia, 510
argentea, Seminula, 355
argillensis, Pecten, 500
argutus, a,
Fulguroficus, 779
Nyassa, 478
arietina, Exogyra, 474
arkonense, Platyceras, 683
armatum, Arthroclema, 153

arundinaceum, Diplophyllum, 75

ashburneri, Cymbophora, 572
asper, era,

Dekayia, 133

Spirifer, 331

asperato-striata, Phylloporina, 141

aspinwallensis, Edmondia, 388
astartiformis, Ctenodonta, 394
atlantica,

Obolella, 188

Terebratulina, 305
atlantoides, Pelagiella, 823
attenuatus, a, um,

Actzon, 806

Dentalium, 581

Rhopalonaria, 116

attleboroughensis, Raphistomina, 629

audaculus, Spirifer, 329
augustina, Sopho-spira, 636
auricula, Crucibulum, 715
aurora,
Chonetes, 237
Lingulella, 193
austinensis, e,
Cerithium, 749
Nerinea, 745
Parasmylia, 99
Radiolites, 553
avellana,
Amauropsis, 721
Lunatia, 797
Natica, 717
aviculatus, um,
Entolium, 506
Pecten, 506
aviculoidea, Megambonia, 411
aviculoides, Myalina, 455

bacillum, Nodosaria, 10
baileyi, Endothyra, 11
baptista, Velatella, 707
barabini, Inoceramus, 445
barabuense, Triblidium, 604
barbarensis,
Barbarofusus, 776
Heilprinia, 776
barretti,
Stromatopora, 45
Syringostroma, 45

832 INDEX OF SPECIES.

barrisi, Meristella, 359
basalticus, Favosites, 86
beckei,

Leptostrophia, 215

Stropheodonta, 215
beecheri, Monilopora, 81
bella,

Cymella, 532

Iphidea, 201

Liopistha, 532

Meristella, 356 :

Neptunea, 763

Ophileta, 657

Tornatellea, 806
bellatulum, Callonema, 692
bellicincta,

Hormotoma, 650

Murchisonia, 650
belliplicatus, Unio, 479
bellirugosa, Hebertella, 255
bellistriatus, a,

Ambonychia, 430

Camptonectes, 505

Cypricardella, 535

Leda, 401

Nucula, 395

Pecten, 505
beloitensis, e,

Eccyliopterus, 658

Trochonema, 670
belviderei,

Mesalia, 729

Turritella, 729
belviderensis, Gryphea, 469
beyrichi, Nucula, 396
biangulatus, Neritopsis, 705
bicincta, Lophospira, 632
biconicus,

Rostellites, 792

Volutilithes, 792
bicornis, Climacograptus, 32
bidentata, Nassa, 764
bidorsata, Tetranota, 612
bifidus, Didymograptus, 31
biforata, Platystrophia, 258
bifurcata, Diploporaria, 151
bigsbyi,

Maclurea, 664

Tetragraptus, 29
bilix,

Cyclonema, 668

Sigaretus, 715
billingsi,

Arthroclema, 153

Billingsella, 211

Cyrtodonta, 409

Favosites, 87

Protorthis; 211

Strophomena, 223
bilobus, Bilobites, 259
binneyi, Vorticifex, 817
biplicatus, Leptosolen, 570

biplicifera, um,

Cancellaria, 798

Trigonostoma, 798
biscatenaria,

Pleurotoma, 803

Surcula, 803
biseriatus, Productus, 244
bispiralis, Lophospira, 636
bisulcata,

Corbula, 574

Cyclospira, 309

Grammysia, 381
boiplex,

Bittium, 747

Styliferina, 747
borealis,

Anisomyon, 813

Duncanella, 76

Hebertella, 254
bosquense, Cerithium, 748
bovidens, Dielasma, 303
bowdeni, Lophospira, 635
boydi, Actinopteria, 449
branneri,

Glauconia, 738

Vicarya, 738
brevidentata, Cassidaria, 759
brevifrons, Nemodon, 405
brevirostris, Perissolax, 767
brevis,

Paleoneilo, 400

Soleniscus, 700
bridgerensis, Physa, 816
bryani, Ostrea, 464
bucculentum, Platyceras, 684
buelli, Salpingostoma, 614
bulbiformis, Amauropsis, 722
bulbosa, Tancredia, 554
bulimiformis, Bulimorpha, 699
bulloides, Globigerina, 10
burlingtonensis,

Edmondia, 388

Pecten, 499

Productus, 244

Rhipidomella, 266
byrnesi, Byssonychia, 431

caduloide,
Dentalium, 581
Levidentalium, 581
czspitosum,
Diplophyllum, 74
Idiostroma, 43
calcareformis, e,
Hapsiphyllum, 58
Zaphrentis, 58
calcifera, Syntrophia, 271
caliculum,
Enterolasma, 56
Streptelasma, 56
californica,
Acteonina, 807

INDEX OF -SEACTERS. 833

californica,
Opis, 540
caloosaénsis, e,
Cerithium, 749
Heilprinia, 776
Rhinoclavis, 749
calverta, Volvula, 810
calvertensis,
Acus, 799
Cylichna, 811
Terebra, 799
calvini,
Ctenodonta, 394
Dielasma, 302
cameratus, Spirifer, 336
campbellanus, Uncinulus, 291
camura, Trematospira, 345
canadensis,
Cyrtodonta, 410
Favosites, 87
Hederella, 120
° Hercynella, 811
Megalomus, 410
Panenka, 389
canaliculatus, um,
Orthodesma, 380
Sycotypus, 770
cancellatus, a,
Aviculopecten, 488
Desmograptus, 26
Limoptera, 422
Nucula, 396
Protowarthia, 611
capax, Rhynchotrema, 282
capillaria, Gyroma, 647
capulus, Igoceras, 689
carbonarius, a,
Cypricardinia, 536
Euphemus, 621
Fistulipora, 125
Naiadites, 477
Placunopsis, 510
Stenopora, 134
carboniferus, Acanthopecten, 492
carditoides, Velatella, 707
caricum, Fulgur, 769
carinatus, a, um,
Carinaropsis, 626
Cyrtolites, 610
Glauconome, 151
Goniophora, 519
Orthonota, 378
Pinnatopora, 151
Platyceras, 683
Semele, 568
Tropidoleptus, 305
carinifera, Bucanopsis, 622
carleyanus, Strophostylus, 678
carlottensis, Astarte, 539
carltoni, Physa, 815
caroli, Aviculopecten, 488
carolinensis, Etea, 542

carter,
Goniobasis, 744
Syringothyris, 341
castellana, Stricklandinia, 275
catenulatus, Halysites, 96
catilloides, Euomphalus, 661
catskillensis,
Amnigenia, 477
Archanodon, 477
cayuga, Rensseleria, 301
cellulosum, Clathrodictyon, 41
centralis,
Anisomyon, 812
Calyptrea, 713
centronatus, Spirifer, 334

- centrota,

Stromatopora, 45
Syringostroma, 45
cerithidioides,
Bittium, 748
Styliferina, 748
cestriensis, Fenestella, 143
chautauque, Phragmostoma, 625
chemungensis,
Goniophora, 520
Leiopteria, 425
Modiomorpha, 515
Mytilarca, 432
Paracyclas, 555
Parallelodon, 403
Pterinea, 421
Schizodus, 482
Schuchertella, 230
chesterensis, Orthonychia, 688
childrani,
Hemipleurotoma, 801
Pleurotoma, 8o1
chipolanus, a, um,
Crucibulum, 714
Strombus, 758
Turbinella, 782
choctavensis,
Chlamys, 501
Pecten, 5or
chrysallis,
Goniahasis, 742
Pachymelania, 742
chrysalloidea,
Goniobasis, 742
Pachymelania, 742
cincinnatiensis,
Whiteavesia, 517
Zygospira, 308
cinerea, Urosalpinx, 784
cingulata,
Amplexopora, 131
Archinacella, 606
Kutorgina, 209
circularis, Grammysia, 383
cirratus, Planorbis, 819
clappi, Chonostegites, 90
clathrodon, Mactra, 571

834 INDEX VOP SPECIES.

clausus, a,
Favosites, 88
Meekopora, 126
cleburni, Pachymelania, 742
cliffordana, Zaphrentis, 58
cliffwoodensis, Isocardia, 561

clintonensis, Monograptus, 34

clintoni, Lingula, 197

clymenioides, Straparollus, 654

coalescens, Pleurocora, 100
coalvillensis, Glauconia, 739
cobourgensis, Lingula, 195

colligatum, Eridophyllum, 72

coloradoénsis,
Billingsella, 210
Pyropsis, 765
columbella, Exogyra, 474
columinis, Goniobasis, 744
columnare, Stylodictyon, 41
comis, Gypidula, 278
communis,
Actinopteria, 447
Archimedes, 147
Astyris, 761
Columbella, 761
Grammysia, 383
Hemipleurotoma, 802
Nodosaria, 10
Pleurotoma, 802
compacta, Ophileta, 656
complanatus, a,
Chonostrophia, 239
Dicellograptus, 32
Modiomorpha, 514
Ophileta, 656
complexicosta,
Chlamys, 500
Pecten, 500
compressirostra, Ostrea, 465
compressus, a,
Calyptraphorus, 752
Petalotrypa, 131
Phragmolithes, 617
conanti, Planorbis, 820
conatum, Cyathophyllum, 66
concavus, a,
Adeorbis, 705
Anoplotheca, 350
Stropheodonta, 216
concentricus, a,
Lichenalia, 165
Modiolopsis, 512
Modiomorpha, 515
Productella, 242
Schizobolus, 203
Stromatopora, 41

conchyliophora, Xenophora, 723

concinnus, a,
Nucleospira, 349
Spirifer, 321
conferta, Pinnatopora, 151
confluens, Heliophyllum, 68

congeneris, Myalina, 454
congesta,
Glycimeris, 419
Hyattella, 348
Ostrea, 461
congregata, Chama, 546
conica, um,
Cerithium, 749
Clathrospira, 644
Igoceras, 689
Newtoniella, 749
Orthonema, 696
conifollis, Cystiphyllum, 63
conoidea, Odostomia, 710
conradi,
Dinobolus, 190
Gyrodes, 720
Leptosolen, 570
Pecten, 497
Veniella, 538
Viviparus, 725
Volutilithes, 792
Volutomorpha, 792
conradiana,
Cancellaria, 798
Gyrodes, 721
conradinus, Mytilus, 521
consimilis,
Cypricardinia, 536
Pterinea, 422
consobrinus,
Delthyris, 331
Spirifer, 331
consortis, Limnza, 816
constricta,
Colpomya, 516
Palzoneilo, 400
contractus, a,
Camaroteechia, 288
Martinia, 341
Sphenotus, 525
contrarium, Fulgur, 769
convexa, um,
Fusispira, 697
Goniobasis, 742
Grypheza, 471
Michelinia, 89
Orbiculoidea, 204
Triblidium, 604
convolutus, a,
Planorbis, 818
Zaphrentis, 57
cooperensis, Reticularia, 339
cooperi,
Antalis, 579
Dentalium, 579
copei, Physa, 816
cora, Productus, 246
corallinensis, Spirifer, 320
corbuliformis, Nucula, 396
corniculum,
Heliophyllum, 68

INDEX: OF SP EE DE.

corniculum,
Streptelasma, 55
cornuta, Aulopora, 79

cornutiformis, Hypseloconus, 605

coronatus, Chonetes, 236
corrugata, :
Cimitaria, 528
Gryphea, 468
Stropheodonta, 213
cossmannii, Bittium, 747
costalis, Orthis, 250
costatus, a, um,
Allorisma, 524
Crucibulum, 714
Cylichna, 810
Exogyra, 476
Panenka, 390
Productus, 246
Stropheodonta, 217
coteroi, Arctica, 537.
couesii, Viviparus, 725
coxanus, Aviculopecten, 488
crassicollis, Aucella, 458
crassifibra, Caprina, 549
crassinoda, Porcellia, 627
crassiplica, Corbula, 574
crassus, a,
Bellerophon, 620
Cyprimeria, 562
Derbya, 231
Obolella, 188
Orthothetes, 231
Pachydictya, 160
Platystrophia, 258
crebrilineata, Nerita, 706
crebripora, Fenestella, 142
crenata, Gyrodes, 720
crenistria, Schuchertella, 231
crenistriata, Crania, 207
crenulata, Poleumita, 667
crenulimargo, Ostrea, 459
cretacea,
Cristellaria, 9
Lucina, 556
Ostrea, 462
cribriforme, Coscinium, 161
cribrosa, Stictoporella, 157
crispus, Spirifer, 319
crusta, Helix, 822
cryptodens, Cladopora, 93
cryptolites, Oxydiscus, 616
cuboides, Hypothyris, 295
cuculloides, Barbatia, 417
culbertsoni,
Fasciolaria, 773
Piestrocheilus, 773
cultellata, Polypora, 149
cultrata, Cristellaria, 9
cultrispira, Nerinea, 745
cumberlandia, Turritella, 734
cuneatus, a, um,
Endodesma, 527

cuneatus, a, um,
Lingula, 197
Maclurea, 666
Maclurina, 666
Rhynchotreta, 283
Schizodus, 482
Sphenotus, 525
cuneiforme, Flabellum, 1o1
cuneus, Conocardium, 437
cunule, Carinaropsis, 626

curtocardinalis, Aviculopecten, 489

curtus, a, um,
Lingula, 195
Lucina, 557
Lunulicardium, 428
Pseudomonotis, 452
Schizodus, 483
curvata, Homotrypa, 129
curvilineatus, a,
Acus, 799
Oxydiscus, 616
Terebra, 799
curviliratus, a,
Acus, 800
Terebra, 800
curvirostratus, Typhis, 786
cuyahoga, Lingula, 197
cyclopterus, Spirifer, 321
cyclostomus,
Straparollus, 655
Strophostylus, 677
cylindracea, Ptilopora, 151
cylindricus, a,
Fusulina, 12
Michelinia, 89
Pentamerus, 276
Phthonia, 376
Whitfieldella, 347
cymbula, Carinaropsis, 626

cyrtolites, Orthonychia, 688

dalei, Callopora, 139
dalli,
Ringicula, 809
Rostellites, 793
Terebra, 799
Volutilithes, 793
dalmani, Cyrtina, 313
danz, Unio, 480
davidsoni,
Acervularia, 69
Radiolites, 553
Stricklandinia, 274
dawsoni, Seminula, 355
decewi, Pleuronotus, 659
decisa, Panopea, 576
declivis, Tellina, 567

decorticatum, Blothrophyllum, 60

decussata,
Actinopteria, 449
Rissoina, 723

defiecta, Dinorthis, 252

8 36 INDEX .OF SPECIES.

deformata, Archinacella, 605
deformis, Inoceramus, 443
dekayi, Leiopteria, 425
deleta, Archinacella, 606
delicatula,

Bythopora, 133
Stomatopora, 118
delphicola, Loxonema, 693
deltoidea, Rafinesquina, 212

demissa,
Pterinea, 419
Stropheodonta, 217
densa, um,

Stromatopora, 44
Syringostroma, 44
dentalium, Platyceras, 682

dentatus, a, um,

Buskopora, 126

Diplograptus, 34

Rhynchotrema, 281
denticulata, Marginella, 789
denticulifera, Ostrea, 462
dentonensis, Plicatula, 508
depressa, um,

Gyrodes, 719

Isonema, 692
desiderata, Hormotoma, 650

desmophyllum, Balanophyllia, 104

devexa, Siphonalia, 762
deweyi, Dosiniopsis, 565
dichotomus, a,
Ceratopora, 80
Diamesopora, 166
Panenka, 389
Staurograptus, 27
diespiter, Helix, 822
diffusa, Drymotrypa, 142
digitatus, a,
Brachiospongia, 17
Favosites, 88
Onychocella, 169
dilatatum, Platyceras, 682
diluvianus Conus, 805
dimidius, Inoceramus, 441
diminuta, Volvula, 810
discus, Microcyclus, 65
disjunctus, Spirifer, 333
dispandus, Pterinopecten, 493
dispar, Loxopteria, 427
dissimilis, Drillia, 804
disstoni, Planorbis, 820
distans,
Drillia, 803
Eccyliomphalus, 663
distincta, Ceramoporella, 122
distorta,
Aporrhais, 754
Tessarolax, 754
divaricatus,
Dicellograptus, 32
Spirifer, 326

diversus, a,
Clitambonites, 270
Leda, 4o1
dixonensis, Vanuxemia, 414
d’orbignyi, Hadrophyllum, 65
doris, Paracardiuni, 392
dotis, Camaroteechia, 287
dryope, Eotomaria, 642
dubia,
Goniophora, 519
Modiolopsis, 513
Rhipidomella, 266
dumosa, um,

Cavaria, 168
Platyceras, 684
duodenarius, Spirifer, 323

duplicatus, a, um,
Aviculopecten, 488
Gyronema, 671
Natica, 719
Neverita, 719
Trochonema, 671

durkei, Corbicula, 543

dyeri, Phragmolithes, 618

eatoni, Stromatoccerium, 46
ebenina, Drillia, 804
eboracensis, Phanerotinus, 656
eborea, um,
Calliostoma, 703
Eulima, 709
Leda, 402
elaborata, Eupsammia, 106
elderi, Lingula, 196
elegans,
Fenestella, 142
Heliolites, 98
Prothyris, 377
elegantula,
Aspidopora, 130
Callopora, 140
Coscinella, 158
Crenella, 522
Dalmanella, 261
Trachypora, 95
ella,
Lingulella, 193
Westonia, 193
elliptica, Paracyclas, 554
elongatus, a,
Amphigenia, 279
Anthracomya, 478
Panopea, 576
Subulites, 696
elora, Euomphalopteris, 630
emacerata,
Dalmanella, 260
Pterinea, 419
emaciata, Fenestella, 143
emarginata, Palzoneilo, 400
emmonsi,
Cymbophora, 573

INDEX OF SPECIES. 837

emmonsi,
Favosites, 86
Hypothyris, 294
emoryi, Trigonia, 484
encrinoides, Turritella, 731
endlichi, Goniobasis, 742
engelmanni, Corbula, 574
engonata, um,
Pleurotoma, 803
Surcula, 803
Vasum,
ensiformis, Gervilliopsis, 440
epidermatus, Favosites, 86
equalis, Heilprinia, 775
equilatera, Ctenodonta, 395
equilateralis,
Paleocapulus, 68
Tellina, 567
equiplicata, Rhynchonella, 298
equiradiata, Rensseleria, 300
equistriata,
Pseudomonotis, 451
Trigonia, 484
Turritella, 733
erectum,
Actinodesma, 423
Platyceras, 683
eriensis, Spirifer, 320
erinacea, Honeoyea, 429
estrellanus, a,
Chlamys, 503
Lyropecten, 503
Pecten, 503
etna, Euconia, 642
eudora, Spirifer, 318
eufaulensis, e,
AZnona, 568
Cardium, 559
Meretrix, 564
Nemodon, 405
_Trigonia, 485
eugenia, Liospira, 641
eurekaénsis, Rhynchonella, 297
euryteines, Spirifer, 326
eva, Lingula, 196
evansana, Trigonia, 485
evansi, Yoldia, 402
evax,
Homeeospira, 344
Retzia, 344
exaltata, Turritella, 735
excavatus, a,
Cyprimeria, 562
Sycotypus, 770
exfoliatus, Pterinopecten, 492
exiguus, a,
Bellerophon, 619
Breviarca, 409
Tzniopora, 161
exilis,
Anchura, 750
Barbarofusus, 776
Heilprinia, 776

expansus, a, um,
Actinostroma, 39
Capulus, 712
Gyrodes, 721
Paleocapulus, 686
Salpingostoma, 614
Strophostylus, 678

extenuatus,
Camptonectes, 506
Pecten, 506

faba, Modiolopsis, 511
falcata, Ostrea, 463
falciformis,

Aporrhais, 755
Escharopora, 156
fasciata, Orthostrophia, 256

fasciculatus,

Aviculopecten, 486

Productus, 245
favositoidea, Michelinia, 90
favosus, Favosites, 84
fecunda,

Ctenodonta, 394

Palxoneilo, 399
felix, Physa, 816
fenestratum, Actinostroma, 40
fertile, Batostoma, 136
festinata, Nisusia, 211
fibratum, Tetradium, 99
fibristriata, Mytilarca, 433
fibrosa, Hindia, 14
filosa, Schizocrania, 202
fimbriata, us,

Pachydictya, 159

Reticularia, 338

Phragmolithes, 617
fischeri,

Chonopectus, 239

Cladopora, 93
fissicosta, Plectorthis, 252
fissurella, Igoceras, 690
fistulata, Polypora, 149
flabellaris, Homotrypa, 129
flabellata, Diastoporina, 120
flabelliforme, Dictyonema, 24
flabellites,

Anoplotheca, 351

Leptoceelia, 351

Orthis, 251
flabellum,

Cornellites, 421

Pterinea, 421
flexuosus, a,

Dendrograptus, 26

Striatopora, 94
floreale, Ascodictyon, 117
florida, Constellaria, 136
floridanus, a,

Cryptonatica, 719

Lathyrus, 777

Natica, 719

838 INDEX OF SPECIES.

fluviatilis, e,
Cerithiopsis, 749
Cerithium, 749
foliaceus, Diplograptus, 33
follis, Plasmopora, 98
formosus, a, um,
Orthonychia, 687
Rhynchospira, 344
Spherium, 544
Stenochisma, 288
Viviparus, 727
fornacula, Spirifer, 327
fornicata,
Barrandella, 276
Clorinda, 276
Crepidula, 714
fragilis, e,
Helopora, 152
Inoceramus, 441
Lunulicardium, 428
Pterochenia, 428
Sigaretus, 715
franconiensis, Hypseloconus, 605
fraterna, Isocardia, 561
frondosa,
Ceramophylla, 123
Clathropora, 156
Proboscina, 118
fucanus,
Chlamys, 504
Pecten, 504
fultonensis, Athyris, 352
furcifera, Cladophyllia, 100
furcillatus, Thamniscus, 150
fusiformis, e,
Allonema, 118
Fulgur, 767
Pugnellus, 755
Soleniscus, 699

gabbi,
Crassatellites, 541
Orthaulax, 756
galba, Cylichna, 811
galeata,
Gypidula, 278
Sieberella, 278
galenaénse, Lingulasma, 199
galtensis,
Eotomaria, 643
Tlionia, 379
- gamagei, Acrothele, 200
gastrodes, Pteria, 446
gatunensis, Turritella, 732
gebhardi,
Platyceras, 680
Pterinea, 420
geinitzi, Allorisma, 523
gemma,
Acrotreta, 199
Obolella, 189
germanus, Aviculopecten, 491

gesneri, Endodesma, 527
gibberula, Ctenodonta, 393
gibbosa, Monopteria, 450
gigantea,
Cucullea, 407
Naticopsis, 674
Zaphrentis, 56
gigas, Phillipsastrea, 69
gilberti,
Cystodictya, 160
Inoceramus, 443
gilli, Viviparus, 725
glaber, bra,
Chonetes, 237
Martinia, 340
Ostrea, 464
glandula, Gibbula, 703
glansfagea, Centronella, 299
globosa, Grammysia, 381
globulosa, Textularia, 10
gnathophora, Rhynchonella, 298
goldfussi, Alveolites, 92
goodelli, Nerinea, 745
gouldii, Bakewellia, 438
gracilenta, Goniobasis, 742
gracilis, e,
Ccenograptus, 28
Dentalium, 579
Dictyonema, 25
Hormotoma, 649
Soleniscus, 700
graciloides, Cancellaria, 797
grandis,
Cyrtodonta, 409
Evactinopora, 164
Psiloconcha, 386
Remerella, 206
Trimerella, 192
graniferus, Vermetus, 737
granosus, um,
Allorisma, 524
Ceeloconus, 154
granulata, Stromatoporella, 42
granulifer, era,
Batostomella, 133
Chonetes, 238
granulosus, Spirifer, 328
grayvillense, Phanerotrema, 638
gregarius, a,
Cypricardella, 535
Hypsipleura, 739
Schizodus, 482
Spirifer, 324
greggi,
Chlamys, 502
Pecten, 502
grieri, Spirifer, 324
grimesi, Spirifer, 335
griscombi, Fissuridea, 708
grosvenori, Pugnax, 295
gryphorhynchus, Anomia, 510
guelphensis, Pycnostylus, 62

INDEX” OF SSP BC TE.S.

hainesi, Ortonella, 412
haitensis, e,
Fusus, 774
Vasum, 782
haleana, Balanophyliia, 105
halei, Crassatellites, 542
haliotoides, Platyceras, 685
hallana, Productella, 241
halli,
Bucania, 614
Columnaria, 71
Heliophyllum, 68
Lunatia, 717
Natica, 717
hamiltonensis,
Cyrtina, 313
Cystodictya, 160
Goniophora, 519
Streblotrypa, 155
hamiltonize,
Amplexus, 59
Craniella, 208
Dictyonema, 26
Favosites, 87
.Loxonema, 693
Parallelodon, 403
Pholidops, 209
Spherodoma, 7o1
hannibalensis, Grammysia, 383
harlani, Terebratula, 304
harpuloides, Nassa, 764
harrisi, Pyrula, 760
hawni, Pseudomonotis, 451
haydeni, Ostrea, 461
hayniana, Vanuxemia, 414
headleyana, Strophonella, 220
healeyi,
Chlamys, 504
Patinopecten, 504
Pecten, 504
hecale, Straparollus,’ 655
helderbergiz, Favosites, 85
helicteres, Lophospira, 632
hemiplicatus, a,
Enteletes, 270
Parastrophia, 271
hemisphericus, a,
Anoplotheca, 350
Chonetes, 235
Ceelospira, 350
Receptaculites, 19
Stropheodonta, 216
henekeni, Fusus, 774
hero, Panenka, 390
heros,
Lunatia, 719
Natica, 719
herricki, Bythopora, 133
hilgardi, Tapes, 566
hilli, Gryphza, 468
hillsboroénsis, e,
Cerithium, 749

hillsboroénsis, e,

Potomides, 749

Tympanotonus, 749
hirsuta,

Cliothyris, 354

Parazyga, 346
hisingeri,

Favosites, 84

Syringopora, 82
hispida, Chilotrypa, 125
holmesianus, Unio, 480
holmesii, Mitra, 789
holopiforme, Acanthonema, 691
hopkinsensis, Diplodonta, 557
horridum, Vasum, 783
horsfordi, Camarotcechia, 287
houghtoni, Nucula, 396
hubbardi, Rhynchonella, 298
huerfanensis, Siliqua, 569

humboldtensis, Terebratula, 304

humerosa,
Pyrgulifera, 741
Turritella, 732
humifusa, Hernodia, 120
humilis, e,
Calliostoma, 703
Callonema, 692
Eutrochus, 703
Paleacmza, 607
Veniella, 539
humorosum, Cyclonema, 669
hybrida, Rhipidomella, 263
hystrix, Atrypa, 311

ida, Goniophora, 519
idonea, Glycimeris, 419
ilicifolius, Phyllograptus, 30
illinoisensis,

Chonetes, 237

Trepospira, 648
imbricata, Ceramopora, 121
impolita, Anolotichia, 123
impressa,

Atrypa, 310

Centronella, 300

Goniobasis, 742
inequi. See inequi
inaurata,

Bulbifusus, 783

Mazzalina, 783

incepta, Polypora, 148

incilifera, Drillia, 803
inciso-lobata, Astylospongia, 14
incisurata, Cystodictya, 160
inclusa, Ceramoporella, 122
inconstans, Pleuromya, 523
increbescens, Spirifer, 336
incrustans,

Paleschara, 166
Stromatoporella, 43
incurvata, Strophomena, 223

indenta,
Cypricardinia, 536

839

840 INDEX HOF SPECIES.

indenta,

Turritella, 733
indianensis, Camaroteechia, 284
indianola, Plectorthis, 251
inequalis, Schuchertella, 231
inequiradiata, Stropheodonta, 216
inequistriata, Stropheodonta, 217
inequivalve, Rhynchotrema, 281
infans, Mangilia, 804
inflatus, a,

Fusispira, 697

Productus, 247

Stomatopora, 118
informata, Schizoporella, 170
inoceriformis, Clementia, 562
inornata,

Meekospira, 699

Ostrea, 464

Psiloconcha, 387
insculpata, Melania, 740
insculpta, Hebertella, 255
insignis, LeptoBolus, 194
intercalaris, Spherodoma, 7or1
interlineatus, Aviculopecten, 489
intermedius, a,

Archimedes, 147

Byssonychia, 431

Ceratopora, 80

Pterinopecten, 492

Whitfieldella, 347
internascens, Anastrophia, 272
interplicata, Anastrophia, 272
interrupta, Turbonilla, 710
interstinctus, Heliolites, 97
interstriatus, a,

Schuchertella, 228

Streptolathyrus, 778
invaginata, Gervilliopsis, 439
invenusta, Goniobasis, 743
iota, Volvula, 810
iowensis (iowaénsis),

Ischadites, 19

Lingula, 196

Pholidostrophia, 219

Receptaculites, 19

Spirifer, 329
irregularis, Teredo, 577
irrorata, Balanophyllia, 104
irvingi, Paleacmza, 607
itys, Euryzone, 645

jacksoni,
Calyptraphorus, 753
Ceratopora, 79
jamesi, Allonychia, 432
jeffersonius, a,
Chlamys, 502
Pecten, 502
jerseyensis, Chonetes, 234
johnsoni,
Chlamys, 502
Pecten, 502

julia, Modiola, 521
juvenis, Fusoficula, 780

kansasensis,

Pseudomonotis, 451

Turritella, 729
kennedyanus, Clavilithes, 780
kentuckiensis, Spiriferina, 315
keokuk,

Derbya, 231

Myalina, 453

Orthothetes, 231

Spirifer, 333
kiowana, Anchura, 750
klipparti, Soleniscus, 7o1
knappianum, Ptychodesma, 456
koeneni, Bucanopsis, 623
kiimmeli,

Cardium, 560

Turnus, 577

labiatus, Inoceramus, 443
labiosa, Cladopora, 94
labrosum, Phanerotrema, 638
lelia, Crania, 207
levicosta, Productus, 243
levigata, Rissoina, 722
levis,
Anthracomya, 478
Leiopteria, 424
Loxopteria, 427
Meristella, 356
Reticularia, 339
leviuscula, Exogyra, 474
lamellata, Camaroteechia, 286
lamellosa,
Athyris, 353
Clionychia, 435
Cypricardinia, 535
Megambonia, 412
Orbiculoidea, 204
lanceolata, Prothyris, 377
lanii, Pterinea, 420
lapicida, Raphistomina, 629
laqueata, um,
Cladopora, 92
Conchidium, 274
Pinna, 436
Rimella, 757
larva, Ostrea, 463
laticincta, Ormospira, 631
laticosta, Platystrophia, 258
latus, a, um,
Coscinium, 162
Euomphalus, 659
Megambonia, 411
Tornatellea, 806
laura, Leiorhynchus, 289
laxata, Bythotrypa, 124
laxus, um,
Acanthonema, 691
Archimedes, 148

INDEX’ OF (SPECIES.

laxus, um,

Phanerotinus, 656
leai, Viviparus, 726
leavenworthana, Strophonella, 222
leavenworthensis, Chenomya, 387
leda, Bucanopsis, 623
leidyi,

Helix, 822

Planorbis, 820

Spirifer, 335

Viviparus, 726
lenis, Protocardia, 561
lenticularis, Dosiniopsis, 566
lepidodendroides, Rhombopora, 153
lepidus, Chonetes, 237
leprosa, Xenophora, 723
leucosia, Rhipidomella, 265
levata, Ctenodonta, 394
levettei, Lepetopsis, 609
lichas, Callonema, 692
lichenoides, Cladopora, 92

logani,

Spirifer, 335
lommeli, Halobia, 452
longa, Pteria, 445
longifrons, Yoldia, 403
longispina,

Monopteria, 450

Productus, 247
lucina,

Euryzone, 645

Pleurorima, 645
lugubris,

Discinisca, 205

Ostrea, 461

lumbricalis, Laxispira, 738

lunatus, a,
Cancellaria, 798
Planorbis, 820

lycoperdon, Prasopora, 130

lynx, Platystrophia, 258
lyra, Bucanopsis, 623

841

ligea, Lingula, 197 lyroides, Dichotrypa, 161
limatula,
Drillia, 804

Marginella, 788

maccoyi, Aviculopecten, 491
macfarlani, Schizophoria, 268
limitaris, e, machzeriformis, Ctenodonta, 394
Favosites, 89 macilenta, Goniobasis, 743
Leiorhynchus, 289 maclurii,
limopsis, Volutilithes, 791 Endopachus, 106
limula, Pteria, 446 Leptodesma, 426
limulatula, Drillia, 804 Syringopora, 82
linckleni, Eunella, 303 macropleura, Spirifer, 320
lineare, Ccelidium, 652 macroptera, Limoptera, 422
lineata, um, macrospira,
Diaphorostoma, 680 Campeloma, 727
Niso, 709 Ceelidium, 652
lineolata, Solyma, 570 macrostoma, Bulla, 809
lingualis, Glossites, 384 madisonius, a,
lingwiformis, Pteria, 445 Chlamys, 502
linnzana, Striatopora, 94 Pecten, 502

linneyi, Orthorhynchula, 281
lintea, Cymbophora, 573
lirata,
Crepidula, 713
Grammysia, 382
INucula, 395
Paracyclas, 555
litchfieldensis, Camaroteechia, 286
litterata, Oliva, 795
lituiformis, Calaurops, 662
livia, Rhipidomella, 264
lobatula, Truncatulina, 11
lodiensis, e,
Orbiculoidea, 204
Paleocapulus, 687
Platyceras, 687
logani,
Chonetes, 237
Ctenodonta, 394
Dichograptus, 28
Loganograptus, 28
Maclurea, 664

magna, Maclurea, 664

magnifica, um,
Chonophyllum, 62
Leptostrophia, 215
Platyceras, 682
Stropheodonta, 215

magniventer, Stropheodonta, 215

magnolia,
Chlamys, 502
Lyropecten, 502
Pecten, 502
maia,
Hormotoma, 651
Hormotomina, 651
Martinia, 340
major,
Hormotoma, 650
Lyrodesma, 481
Modiola, 521
Thecia, 91
mamillaris, e,
Lithostrotion, 77

842 INDEX OF SPECIES.

mamillaris, e,
Receptaculites, 19
mamillatus, Strombodes, 71

mammulata, Monticulipora, 127
manitobaénsis,

Maclurea, 666

Maclurina, 666
mantelli, Orbitoides, 12
marcida, Monopleura, 548
marcouana, Bucanopsis, 624
marcoui, Gryphea, 467
marcyi, Eumetria, 346
marginalis, Atrypa, 309
marginicinctus, Productus, 245
maria, Meristina, 351
marionensis, Spirifer, 334
marshallensis, Palzoneilo, 400
martini,

Dentalium, 578

Levidentalium, 578
marylandicus, a,

Chlamys, 503

Emarginula, 708

Fissuridea, 709

Lunatia, 718

Natica, 718

Pecten, 503

Pholadomya, 530

Pleurotoma, 802

Septastrea, Io1

Surcula, 802

Tudicla, 765

Volvula, 810
mathewsoni, Cinulia, 807
‘matthewi, Acrothele, 200
‘maximus, um,

Fulgur, 768

Radiolites, 553
‘medialis, .e,

Cumingia, 569

Cyclonema, 669

Eatonia, 296

Lophospira, 634

Spherodoma, 7o1
medians, Odontofusus, 780
mediavia, Natica, 718
mediaviensis, e,

Dentalium, 580

Graptacme, 580
medinaénsis, Schizodus, 482
meedsi, Dinorthis, 253
meeki,

Anisomyon, 812

Limneza, 817

Liopistha, 532

Rhytophorus, 814
meekianum, Cardium, 560
megera, Filifascigera, 167
megambona, Whitella, 415
megastoma,

Glyptopora, 164

Heliolites, 97

megastoma,

Phractopora, 164
meigsil, Physa, 816
melanoides, Chrysallida, 710
melie, Lingula, 198
meniscus, Astrzospongia, 18
mercenaria, Venus, 563
mesenterica, Ostrea, 463
mesicostalis,

Delthyris, 332

Spirifer, 332
mesistrialis, Spirifer, 332
mesolobus, Chonetes, 238
metastriata, Linearia, 568
mexicana, Gryphea, 467
mexicoanus, Productus, 247
meyeri, Falsifusus, 774
Miamiensis, Cuneamya, 378
michelini, Rhipidomella, 266
mickleboroughi, Rhytimya, 526
micronema, Barbatia, 417
micropora, Ceriopora, 168
micula, Liospira, 640
migrans, Siphonalia, 762
milium, Tinostoma, 705
millepunctata, Trematis, 202
minnehaha, Chenomya, 387
minnesotensis (minnesotaێnsis),

Berenicea, 119

Homotrypa, 129

Lophospira, 636

Rafinesquina, 212
minor, Thecia, 91
minuta,

Aclisina, 696

Bulimorpha, 699

Cyclora, 673

Marginella, 788

Solenospira, 653
minutissimus, a,

Anomphalus, 671

Protospirialis, 671
minutistriata, um,

Dentalium, 580

Graptacme, 580
mississippiensis, e,

Ampullina, 718

Buccinum, 761

Mourlonia, 646

Murex, 785

Natica, 718

Oculina, 103

Pyrula, 760
missouriensis, —

Cardiomorpha, 386

Orbiculoidea, 204
modesta,

Crania, 208

Lingula, 196

Saffordia, 385

Zygospira, 308
modiolaris, Modiolopsis, 512

INDEX

modioliformis,

Ischyrodonta, 416

Whiteavesia, 517
modiomorphoides, Goniophora, 519
monroicum, Conocardium, 438
montfortiana, Bucanopsis, 624
monticulifera, um,

Coenostroma, 44

Stromatopora, 44
montrealensis, Scenella, 608
moorii,

Pleurotoma, 801

Schizolopha, 637
moreauensis,

Cuspidaria, 532

Neera, 532
mormoni, Hustedia, 345
mortoni,

Amusium, 508

Cyprea, 758

Pecten, 508

Turritella, 731

Veniella, 539
mucronatus, a, um,

Chonetes, 235

Gryphza, 469

Spirifer, 330
multicostatum, Loxonema, 694
multilineatum, Campeloma, 727
multilinigera, Modiola, 521
multisinuatum, Platyceras, 682
multistriata, um,

Campeloma, 728

Schizophoria, 267

Trematospira, 345
multitabulata, Callopora, 139
mundula, um,

Liospira, 642

Mitoclema, 121
murchisoni, Spirifer, 322
muricatus, a,

Actinopteria, 448

Productus, 247
musica, Voluta, 794
muta, Paleoneilo, 398
mutabilis,

Aurinea, 795

Eridotrypa, 134

Grypheza, 471

Rhinodictya, 158

Uncinulus, 291

Dactylidia, 796
mutica,

Oliva, 796

Olivella, 796
myrina, Rhynchonella, 298
mysia, Leiorhynchus, 289
mytiloides,

Modiolopsis, 511

Modiomorpha, 514

nacrea, Stropheodonta, 219

OF (SPECIES: 843

nactus, Bellerophon, 620
nanaimeense, Dentalium, 580
nanus, a, um,
Amboceelia, 343
Strophostylus, 678
Subulites, 697
Tinostoma, 704
Valvata, 724
nasuta,
Ctenodonta, 393
Meristella, 359
Ostrea, 463
natator, Phragmostoma, 625
naticiformis,
Nerita, 706
Neritina, 706
navia, Grypheza, 469
navicella, Productella, 240
naviformis, Pterinea, 420
nebrascana, Pteria, 446
nebrascensis (nebraskaénsis),
Chlamys, 500
Dosiniopsis, 566
Goniobasis, 743
Inoceramus, 444
Nerita, 706
Pecten, 500
Productus, 247
nebulosa, Ptilodictya, 156
neglectus, a, ,
Camarotechia, 284
Cucullea, 406
Euchondria, 492
Fistulipora, 125
Nuculites, 397
Spirifer, 335
Strophomena, 224
nettelrothi, Conchidium, 273
nevadaénsis, Reticularia, 338
newberryi,
Acanthonema, 691
Aspidopora, 130
Astartella, 536
Bellerophon, 619
Gryphea, 472
Lingulodiscina, 203
Soleniscus, 700
niagarensis, e,
Alveolites, 91
Chonophyllum, 62
Diaphorostoma, 679
Favosites, 85
Platyceras, 680
Spirifer, 319
nicklesi, Streblotrypa, 155
nicoletti, Zygospira, 308
nitidula,
Aristerella, 518
Limnea, 817
Lymnophysa, 817
Meekospira, 698

-

844 INDEX OF SPECIES.

nitidus, a, um,
Didymograptus, 31
Eunema, 670
Obolella, 189
Trochonema, 670
Whitfieldella, 347
nivea, Turbonilla, 710
nobilis, Uncinulus, 293
nodilirata, Nerita, 706
nodocarinatus, Euphemus, 621
nodocostata, Grammysia, 381
nodosa, um,
Porcellia, 627
Trachydomia, 675
Platyceras, 684
nodostriata, Atrypa, 309
nodulatum, Actinostroma, 40
nodulifera, Goniobasis, 744
nodulosa, Beatricea, 47
noe, Loxonema, 693
nucleolatus, a,
Uncinulus, 291
Whitfieldella, 348
nuptialis,
Aporrhais, 754
Lispodesthes, 754
nycteis, Triblidium, 604

obesus, Typhis, 786
oblata, Rhipidomella, 263
obliquata, Whitella, 415
obliquus, a,
Arthrostylus, 152
Cinulia, 808
Ctenodonta, 394
Homotrypa, 129
Trigonarca, 407
obliterato-granosa, um,
Cerithium, 748
Fibula, 748
oblongatus, Nuculites, 308
oblongula, Membranipora, 169
oblongus, a,
Cypricardella, 585
Pentamerus, 275
Pleurophorus, 533 |
obrapum, Fulgur, 769
obscura, Dekayella, 132
obsoletus, a, um,
Acanthonema, 691
Grammysia, 381
Limoptera, 422
Parallelodon, 404
Tetranota, 613
occidaneus, Aviculopecten, 490
occidens, Phanerotrema, 638
occidentalis, e,
Actinodesma, 423
Arctica, 537
Atrypa, 311
Aviculopecten, 490
Caprina, £40

occidentalis, e,
Conchidium, 273
Corbicula, 544
Fenestrapora, 145
Haminea, 809
Hebertella, 255
Hypsipleura, 739
Leptobolus, 194
Lucina, 556
Pholadomya, 530
Pleurophorus, 533
Solemya, 375

octobrachiatus, Dichograptus, 28

octolirata, Pyropsis, 767

cehlerti, Ceelidium, 652

ohioێnsis, e,
Anthracopupa, 821
Ceramoporella, 122
Conocardium, 438
Labechia, 46
Paracyclas, 554
Receptaculites, 19
Trimerella, 191

oklahomaێnsis, Aviculopecten, 492

olivaceus, Melampus, 814
oneidaénse, Acrophyllum, 60
oniscus, Corbula, 575
operculiformis, e,

Entolium, 507

Pecten, 507
orbiculatus, Lyriopecten, 494
orbignyanus, Discotrochus, 102
orcutti, Coralliochama, 551
ordinatus, Chonostegites, 91
ornatissima, Margarita, 704
ornatus, a, um,

Cyrtolites, 609

Lunulicardium, 428

Trachypora, 95
orthonota, um,

Endodesma, 527

Modiolopsis, 512
ostiolata, um,

Chilotrypa, 125

Clathrodictyon, 41
ostrarupis,

Pleurotoma, 800

Surcula, 800
ostrearum, Drillia, 803
ottawaénsis, Trematis, 202
ovalis, Nematopora, 153
ovata,

Arctica, 538

Aucella, 458

Grammysia, 381

Megambonia, 411

Meretrix, 565

Stromatotrypa, 137
oviformis,

Modiolodon, 516

Plethomytilus, 434

INDEX OF SPECIES. 845

ovoides,
Actzon, 807
Rensseleria, 300
ovula, Nucula, 397
owenana, Dosiniopsis, 565
owenensis, Eccyliopterus, 658
oweni,
Lophospira, 634
Receptaculites, 18
Spirifer, 328

pabulocrinus, Igoceras, 690
pachypleura,

Scalaria, 711

Sthenorhytes, 711
pagoda, Solenospira, 653
pagodiformis, Levifusus, 772
palmata, Astrohelia, 104
paludineformis, Soleniscus, 700
panda, Ostrea, 461
pandora, Schuchertella, 229
pandoriformis, Leda, 4o1
panicum, Diplophyllum, 75
pannulus, Iphidea, 201
papyracea, Pholadomya, 529
paradoxus, Phanerotinus, 656
paralius, Platyceras, 686
parilis,

Buccinofusus, 762

Tenea, 558
parva, um,

Bakewellia, 438

Leda, 402

Mangilia, 804

Platyceras, 686
parvicella, Heteropora, 168
parvulus, Aviculopecten, 490
patagiata, Requienia, 547
patelliformis,

Anisomyon, 812

Archinacella, 606

Velatella, 707
patenta, Strophonella, 220
patersoni, Stropheodonta, 215
patulus,

Didymograptus, 31

Modiolodon, 516

Ptomatis, 624
patuxentia, Volvula, 810
pauperata, Siliquaria, 738
pauperculum,

Cardium, 558

Dentalium, 579

Levidentalium, 579
pavilionensis, Pentamerella, 277
pavonia, Escharopora, 156
pecosi, Rhipidomella, 266
pectinella, Dinorthis, 253
peculiaris,

Actinotrypa, 164

Eatonia, 296

pedernalis,
Lunatia, 717
Natica, 717

pellucidus, a,
Aviculopecten, 489
Ostrea, 465

pelopea, Schizotreta, 205

pelops, Bellerophon, 619

penelope, Rhipidomella, 265

penitus, a,

Ficus, 760
Pyrula, 760

pennata, Anchura, 751

penniformis, Tzniopora, 161

pentagonus, Strombodes, 70

peracuta, um,
Aviculopinna, 435
Meekospira, 698
Raphistoma, 628

peralta, Nassa, 763

perangulata,

Goniophora, 519

Lophospira, 633
perattenuata,

Myalina, 455

Turritella, 735
percarinatus, Bellerophon, 621

percrassa,
Nucula, 396
Ostrea, 466

perelegans,

Dalmanella, 261

Syringopora, 84
perexigua, Erato, 759
perforata, Loculipora, 146
pergracilis, Exilia, 777
perlamellosus, a,

Delthyris, 320

Spirifer, 320
permiana, Myalina, 455
permutabile, Bittium, 747
pernodosus, Euomphalus, 660
perplanus, a,

Chlamys, 502

Leptostrophia, 217

Pecten, 502

Stropheodonta, 217
perplexa, Reticularia, 340
persa,

Pleurotoma, 800

Surcula, 800
pertenuis, Phacelopora, 121
pertenustriatus,

Camptonectes, 506

Pecten, 506
perundata, Reteporidra, 147
perversa, um,

Schuchertella, 230
pervetusta,

Euconia, 642

Holopea, 677
pervoluta, Protowarthia, 611

846 INDEX OF SPECIES.

petrina, Pinna, 436
petrosus, a,
Gyrodes, 720
Phenacomya, 531
Pteria, 445
Volutilithes, 790
pexatum, Loxonema, 693
pharetra, Turbinolia, 10z
philanthropus, Calliostoma, 703
phillipi, Edmondia, 388
pileolum, Crucibulum, 715
pinguis, Cyprza, 758
pinguiscula, Monopleura, 548
pinniformis, Lingulepis, 193
piochii, Aucella, 458
pisiformis, Nucleospira, 349
pisum, Nerita, 707
placenta, Favosites, 88
planatus, Peneroplis, 9
planiceps, Conus, 805
planicosta, Venericardia, 545
planidorsatus, Euomphalus, 660
planirostris, Cryptonella, 301
planispira, Straparollus, 655
planistrium, Raphistoma, 628
planoconvexus, a,
Amboceelia, 343
Bathyomphalus, 818
Planorbis, 818
planodorsatum, Semicoscinium, 144
planorbis, Solarium, 711
planulatoides, helicotoma, 659
planulatus, a, um,
Helicotoma, 658
Legumen, 571
Nuculites, 397
planumbona, Strophomena, 224
planus, a, um,
Crepidula, 713
Eurymya, 518
Paleoneilo, 399
Soleniscus, 700
Spherium, 544
platessa,
Camptonectes, 506
Pecten, 506
platystoma, Bellerophon, 619
plebeia,
Membranipora, 169
Turritella, 734
plena, Camarotechia, 284
pleromatis, Physa, 816
plexa, Exogyra, 474
plicapressus, Viviparus, 727
plicata, um,
Igoceras, 689
Terebratella, 306
plicatella, Plectorthis, 252
plicatula, Anoplotheca, 350
plumosus, a,
Ostrea, 463
Ptilograptus, 27

politus, a,

Cinulia, 808

Dicellomus, 189

Ringinella, 808
ponderosus, a,

Exogyra, 476

Plethomytilus, 434

Spherodoma, 702
postmortoni, Turritella, 731
poststriatum, Lyrodesma, 481
potens, Panenka, 390
precursa, Byssonychia, 432
precursor, Trachydomia, 674
premorsa, Astylospongia, 14
prenuntia, Dekayella, 132
preumbona, Amboceelia, 342
pretiosa, Linnarssonia, 200
prima, Lingulepis, 193
primevum, a,

Platyceras, 654

Straparollina, 654
primigenius, a,

Modiolopsis, 512

Spherodoma, 702
princeps,

Aviculopecten, 487

Meristella, 358
priscus, a,

Archeozonites, 822

Monomerella, 190

Rhytophorus, 815

Solenospira, 653
prismatica, Prismodictya, 16
pristiniformis, Diplograptus, 34
pristis, Diplograptus, 33
producta, um,

Campeloma, 728

Rhytimya, 526
profundus, a, um,

Lophophyllum, 76

Pteronites, 447

Streptelasma, 54

Stropheodonta, 213

Trematonotus, 616
progne, Liospira, 640
prolabiata,

Aporrhais, 753

Perissoptera, 753
prolifera, um,

Acrogenia, 162

Cryptozoon, 46
prolifica, Zaphrentis, 57
promissum, Blothrophyllum, 60
propatoris,

Anodonta, 480

Anomia, 510
propinqua, Schizophoria, 268
propleura, Gervillia, 439
protexta, Liopistha, 532
protocommunis,

Hemipleurotoma, 802

Pleurotoma, 802

INDEX

proutanus, a,

Archimedes, 147

Hemitrypa, 146

Holopea, 677
providencesis, Aviculopecten, 489
proximatus, Clonograptus, 27
proximus,

Hipparionyx, 233

Inoceramus, 444
prudentia, Viviparus, 727
pseudogaleata,

Gypidula, 278

Sieberella, 278
pseudolineata, Reticularia, 339
pteromatis, Physa, 816
pugilis, Strombus, 758
pugnus, Pugnax, 295
pulchella, um,

Gyronema, 671

Lophospira, 634

Trochonema, 671
pulchra,

Cladopora, 94

Nicholsonella, 136
punctatus, Productus, 248
punctifrons, Bucania, 614
punctipora, Stictotrypa, 166
punctulifera, Strophonella, 222
pusillus, Chonetes, 236
pustulifera, Stromatopora, 44
pustulosa,

Rhynchopora, 297

Vitulina, 351
puteolata, Intrapora, 158
pyga, Meretrix, 564
pygmea, Modiella, 456
pyramidalis, Drillia, 804
pyriformis,

Corbula, 573

Sycotypus, 770
pyruloides, Caricella, 794
pyrus, Sycotypus, 770
pyxidata,

Metaplasia, 343

Productella, 242

quadrangularis,

Schizodus, 482

Trigonia, 484

Whitella, 415
quadrata,

Monotrypella, 131

Rhombotrypa, 131
quadribrachiatus, Tetragraptus, 29
quadricostata, um,

Ecphora, 787

Leiorhynchus, 289
quadriplicata, Ostrea, 460
quadrisulcata, Lophospira, 632
quadrula, Modiomorpha, 515
quebecensis,

Mesotrypa, 130

OF i SPEEMES,

quebecensis,

Paleacmea, 607
quercollis, Fulgurofusus, 775
quincuncialis, Lyropora, 150
quincyense, Igoceras, 690
quindecemradiata, Arca, 417
quinquecostatus, a,

Neithea, 497

Pecten, 497
quinquenarius, Pecten, 499

radiatus, a,
Byssonychia, 432
Cardiopsis, 386
Clinopistha, 376
Evactinopora, 164
Pholadella, 528
Rhytimya, 526
Spirifer, 318
rafinesquii, Leiopteria, 425
ragsdalei, Ptychomya, 542
ramosus, a,
Callopora, 139
Dicranograptus, 32
Thecia, 91
ramsayi, Euconia, 642
randalli, Nucula, 395
rapum, Fulgur, 769
raricosta,
Delthyris, 325
Spirifer, 325
raynoldsianus, Viviparus, 727
rectangularis, Protowarthia, 611
rectilateralis, e,
Lingula, 195
Triblidium, 603
rectilaterarius, Aviculopecten, 488
rectirostris, Cryptonella, 302
rectistriata, Lophospira, 632
rectum,

- Orthodesma, 379
Stereolasma, 56
Streptelasma, 56

recurvirostris,
Myalina, 454
Zygospira, 307

recurvus, a,

Cimitaria, 528
Hypseloconus, 604
reflexum, Platyceras, 683

regularis,

Soleniscus, 700

Subulites, 696
remex, Strophostylus, 678
remnicha, Plectorthis, 252
remota, Straparollina, 654
repens, Vinella, 118
resupinoides, Schizophoria, 269
reticularis, Atrypa, 310
reticulata,

Dictyonella, 210

Phylloporina, 141

847

848 INDEX OF SPECIES.

reticulata, rugosus, a, um,

Scenella, 608 Loxonema, 695
retifera, Lima, 509 Saxiedva, 575
retiformis, e, Stenotheca, 607

Dictyonema, 25 Stromatocerium, 46

Syringopora, 82 2 Strophomena, 224
retrorsus, Cyrtolites, 610 Sycotypus, 769
retrostriata, Buchiola, 393 rugulata, Euryzone, 645
retusa, Scenella, 608 rustica, um,
reversa, Strophonella, 222 Streptelasma, 55
rhombeus, Schizodus, 482 Urosalpinx, 784
rhomboidalis, Leptena, 226
richardsoni, Pyropsis, 765 saffordi.
richmondensis, Salpingostoma, 614 Breviarca, 408
rigidus, um, Modiola, 522

Pecten, 507 sagenella, Glyptopora, 163

Syncyclonema, 507 sageriana, Camarotechia, 288
rimulata, Membranipora, 170 salteri,
ripleyana, Meretrix, 564 Hormotoma, 649
robustus, a, um, Trochonema, 671

Aclisina, 695 sancti-ludovici,

Barbarofusus, 777 Fenestralia, 150

Calcisphera, 11 Myalina, 453

Cladopora, 94 sancti-sabe, Pholadomya, 529

Cyathophyllum, 66 sao, Ptychopteria, 450

Heilprinia, 777 sappho, Camarotechia, 288

Helicotoma, 659 sayanus, a,

Loxonema, 692 Scalaria, 710

Panenka, 391 Volutilithes, 791
rockymontanus, Spirifer, 337 scabiosa, Crania, 206
roemeri, scabra, Paranomia, 511

Cladopora, 94 scabridus, a,

Pecten; 497 Aviculopecten, 488

Vola, 497 Valvata, 724
rogersi, Leptodesma, 426 scalariformis, Scalaripora, 163
roissyi, Cliothyris, 354 scalaris, Unitrypa, 145
romingeri, scalaspira, Nassa, 764

Cranzna, 302 scalatus, um,

Dielasma, 302 Cerithium, 750

Gypidula, 279 Potamides, 750
rostellata, Leda, 4o1 Pyrazisinus, 750
rostrata, Anchura, 751 scamnata, Poleumita, 667

-rotalia, Trepospira, 648 sceptrum, Dictyospongia, 15
rotuloides, Palzocyclus, 65 scitulus, a, um, -

rotulus, Anomphalus, 671 Chonetes, 237

rotunda, Holopea, 676 Cylichna, 811
rotundata, Vanuxemia, 414 Loxonema, 695

rudis, Yoldia, 403

Ptomatis, 625 scofieldi, Whitella, 415

Straparollus, 654 sculptilis,
rufus, Delthyris, 331

Chicoreus, 785 Melania, 740

Murex, 785 Spirifer, 331
rugatus, secalica, Fusulina, 12

Fulgurofusus, 775 securiformis, Pterinea, 420

Volutilithes, 791 selleformis, Ostrea, 465
rugosus, a, um, semilunata,

Acervularia, 68 Lunatia, 718

Atrypa, 310 Natica, 718

Callopora, 140 semiplicata, Camarotceechia, 286

Eridophyllum, 72 semireticulatus, Productus, 246

Helcionella, 607 senectus, Unio, 480

INDEX: -OF SPECTES,

septariana, Yoldia, 402
seriata, Cladopora, 93
seriatim-granulata,

Mesalia, 729

Turritella, 729
serica, Crenella, 522
sericeus, Plectambonites, 227
serpens, Aulopora, 78
serrulata, Lophospira, 636
setigerus, a,

Chonetes, 237

Crania, 207

Reticularia, 339
sexcarinata, Tetranota, 613
sexsulcatus, Anisomyon, 813
sextans, Dicellograptus, 33
shafferi, Arthropora, 157
shilohensis, Actzon, 806
shumardana, Productella, 242
shumardi,

Amplexus, 59

Anisomyon, 814

Limnea, 817

Polypora, 149

Turbo, 676

Turbonopis, 676
shumardiana,

Lunatia, 717

Natica, 717
sillmani, Scalaria, 710
simcoénse, Synaptophyllum, 73
similis,

Eridotrypa, 134

Euomphalus, 659

Holopea, 676
simplex,

Arthropora, 157

Bactropora, 155

Hastula, 800

Terebra, 800

Zaphrentis, 57
simplicius, Pecten, 498
simpsoni,

Goniobasis, 744
Inoceramus, 441
simulans, Crepipora, 122

simulatrix,
Archinacella, 606
Prasopora, 129
sinuata, um,
Hebertella, 256
Ilionia, 379
Leiorhynchus, 290
sinuosa,

Pterochenia, 429
Ptychopteria, 450
siouxensis, Breviarca, 408

smithi,
Lucina, 557
Venericardia, 544
socialis, e,
Botryllopora, 127

socialis, e,
Ctenodonta, 394
Leptodesma, 426

solarioides, Pycnomphalus, 672

soleniscus, Ostrea, 460
spatulata, Lingula, 197
speciosa, um,
Cardium, 559
Productella, 242
Worthenia, 640
spectabilis, Planorbis, 819
spergenensis, e,
Hapsiphyllum, 58
Straparollus, 655
Zaphrentis, 58
spherulata, Trepospira, 648
spillmani, Cardium, 559
spiniformis, Helopora, 152
spinosa,
Atrypa, 311
Spiriferina, 314
Worthenopora, 165
spinulicosta, Productella, 241
spinulosa,
Batostomella, 133
Bythopora, 134
spirale, Platyceras, 682
spiriferoides, Athyris, 353

849

springvalensis, Omphalotrochus, 667

squamosus, Alveolites, 92
staminea, um,
Conomitra, 790
Mitra, 790
Olivula, 797
Raphistoma, 628
stantoni, Nerinella, 746
stearnsii, Pecten, 500
stellata, um,
Ascodictyon, 117
Favistella, 71
stevensana, Aclisina, 696
stokesi,
Platytrochus, 1o1
Ptychophyllum, 62
Zaphrentis, 57
stolonifera, Reptaria, 120
stramineum,
Dentalium, 579
Synaptophyllum, 73
striecosta, Pterinea, 420

striatellum, Clathrodictyon, 40

striatocostata,
Meekella, 232
Pugnax, 295

striatula, Schizophoria, 268

striatus, a, um,
Aviculopecten, 488
Helcionopsis, 604
Ptilopora, 151
Raphistoma, 627
Spirifer, 336
Strombodes, 71

850 INDEX OF “SPECIES.

striatus, a, um,

Strophonella, 220
stricklandi, Uncinulus, 290
strigilecula, Ostrea, 459
strophomenoides, Orthostrophia, 257
strumosa,

Scalaspira, 785

Urosalphinx, 785
stylopora, Pleurodictyum, 89
subacutus, Oxydiscus, 616
subequata, Dalmanella, 261
subalata,

Modiomorpha, 515

Productella, 241
subannulata, Turritella, 735
subarcuatum, Dentalium, 579
subattenuatus, Spirifer, 333
subaustralis,

Axinea, 418

Glycimeris, 418
subbrevis, Fusispira, 697
subcespitosum, Craspedophyllum, 76
subcarinata,

Dalmanella, 261

Hormotoma, 650
subcircularis, Pseudomonotis, 451
subcompressa,

Corbula, 575

Pleuromya, 523
subconica, Clathrospira, 644
subcostatus, Pleurophorus, 533
subcuneata, um,

Allorisma, 524
Camarophoria, 280
subcylindrica, Haminea, 809
subdecussata, Actinopteria, 449

subemarginata, Tellinopsis, 386

subfusiformis, Fusispira, 697
subglobosa, Ancillopsis, 797
subimpressa, Meretrix, 564
sublevis, e,

Anchura, 752

Bellerophon, 620

Cyclonema, 669

Goniobasis, 744
sublaxus, a,

Archimedes, 148

_ Ophiletina, 657
sublirata,

Hastula, 800

Terebra, 800
submarginata, Polypora, 150
subnasuta, um,

Clinopistha, 376

Orthodesma, 380
suborbicularis,

Megambonia, 411

Ontaria, 391

Pterinopecten, 494
suborbiculata, Exogyra, 474
subovatus, a,

Anisomyon, 813

subovatus, a,

Cyrtodonta, 410

Edmondia, 388

Ostrea, 460

Semele, 568
subpapillosus, Euphemus, 622
subplana,

Leiopteria, 424

Schuchertella, 228
subplicatum, Igoceras, 691
subquadratus, a,

Dinorthis, 254

Euomphalus, 661

Myalina, 455

Protocardia, 560

Seminula, 354
subramosa, Homotrypa, 128
subrectus, a,

Escharopora, 156

Orthonychia, 687

Pentamerus, 275
subrugosus, Euomphalus, 661
subscalarina, Strepsidura, 770
subscalaris, Worthenia, 640
subsidua, Acrothele, 200
subspatulatus, a,

Lingula, 198

Ostrea, 462

Unio, 480
subteniatum, Orthonema, 696
subtenta, Strophomena, 225
subtenuis,

Aulopora, 78

Lirofusus, 779
subtilita, Seminula, 355
subtortuosa, Goniobasis, 744
subtrigonalis,

Corbula, 574

Ostrea, 464
subula, Nerinella, 746
subumbilicata, Valvata, 724
subundata, Lucina, 556
suciensis, Vanikoropsis, 716
sulcatinus, a,

Bucania, 613

Nemodon, 405

Paleoneilo, 400
sulcatus, a, um, .

Aulacophyllum, 59

Cystiphyllum, 64

Delthyris, 319

Pteria, 445

Spirifer, 319

Whitfieldella, 348
sulcomarginata, Bembexia, 647
sumnerensis, Lophospira, 635
superba, Scenella, 608
supracingulata, Eotomaria, 643
supranitidus, Adeorbis, 705
swallovanus, Archimedes, 147
swallovi.

Myalina, 454

INDEX OF SPECIES.

swallovi,

Schizophoria, 268
swantonensis, Iphidea, 201
swinderana, Thecia, 91
symmetricus, um,

Platyceras, 684

Productus, 248

tabulata,
Monotrypa, 138
Syringopora, 83
Worthenia, 639
taf, Trigonia, 484
‘tampe, Turritella, 732
tampensis, Ecphora, 787
taylori, Melania, 741
tenax, Fenestella, 143
tenera, Goniobasis, 744
tennesseensis,
Calceola, 77
Helicotoma, 659
tenuicarinata, Goniobasis, 744
tenuiceps, Semicoscinium, 143
tenuicostata,
Limneza, 817
Pleurolymnea, 817
tenuilamellata, Schizotreta, 205
tenuiliratum, Platyceras, 681
tenuimurale,

Batostoma, 137
Hemiphragma, 137
tenuirama, Rhombopora, 153

tenuis, Rhopalonaria, 117
tenuiseptatum, Heliophylium, 68
tenuistriatus, a, um,
Cardium, 559
Cypricardella, 534
Paleoneilo, 399
Parallelodon, 404
terebra, Loxonema, 694
terebralis, Pleurotoma, 801
terebriformis, Archimedes, 148
terminalis, e,
Allorisma, 524
Trematis, 202
Vanuxemia, 413
testudinaria, Dalmanella, 260
tethys, Camaroteechia, 287
tetricus, Trophon, 787
texanus, a, um,
Arcopagia, 562
Cyprimeria, 562
Exogyra, 473
Monopleura, 548
Parasmylia, 99
Pecten, 497
Protocardia, 560
Radiolites, 553
Requienia, 547
Spherodoma, 702
texta, Syringothyris, 342

textilis,
Actinopteria, 447
Bucanopsis, 623
Holopea, 677
Strophostylus, 677
texturatus,

Rostellites, 793
Volutilithes, 793
thalloides, Dentalium, 580

thallus, Cadulus, 582
thetis, Platyceras, 684
thiemei, Rhipidomella, 265
thompsoni,

Tulotoma, 727

Viviparus, 727
thoracica, Trigonia, 485
thureaui,

Dichograptus, 29

Goniograptus, 29
tibialis, Polorthus, 578
tioga, Schizophoria, 268
tippana,

Aporrhais, 755
. Cucullea, 406

Meretrix, 563

Pterocerella, 755

Turritella, 731
torquium, Campophyllum, 67
torta,

Biflustra, 169

Fistulipora, 125

Lichenalia, 125

Naticopsis, 674
tortilis,

Heteropora, 168

Pseudolathyrus, 778
tortuosum, Platyceras, 682
trabeatus, Levifusus, 771

transversalis, Plectambonites, 227

trapezoidalis, Astarte, 540
trapezoidea, Etea, 542
trentonensis, e,

Ceeloclema, 122

Crania, 207

Glossina, 195

Hormotoma, 650

Lingula, 195

Rhinidictya, 159

Strophomena, 223
triangularis, Phragmolithes, 617
triangulus, Eccyliomphalus, 663
tribulosum, Platyceras, 685
tricenaria, Orthis, 250
tricostatus, a,

Lyriopecten, 495
trigona, Veniella, 538
trigonalis, Ostrea, 465
trilineata, um,

Solarium, 712

Turritella, 731
trilira, Turritella, 731
trilix, Lophospira, 637

851

852 INDEX OF SPECIES.

trilobata,
Bucaniella, 612
Strophomena, 223
trinodiferous, Calyptraphorus,
trinucleus, Seminula, -355
triqueter, tra,
Nuculites, 398
Prismopora, 162
Textularia, 10
Verneuilina, 10
tritonis, Fulgur, 768
trivittatoides, Nassa, 763
trochiformis,
Pyropsis, 765
Viviparus, 727
troosti, Bellerophon, 618
tropidophorus, a,
Lophospira, 635
Pleurophorus, 533
troyensis, Fordilla, 380
truncatula, Cuneamya, 378
truncatus, a,
Cucullza, 407
Goniophora, 519
Ischyrodonta, 416
Palzoneilo, 400
Schizobolus, 203
Sphenotus, 525
Strophalosia, 240
tryoni, Vorticifex, 817
tubeformis, Aulopora, 79
tuberculata, um,

Fulgur, 768
Stromatoporella, 43
tuberculosa, Trematopora, 139

tuberosus, um,

Favosites, 86

Hydnoceras, 17
tubiporoides, Syringopora, 82
tucumcarii, Gryphea, 468
tulliensis, Schizophoria, 268
tullius, Spirifer, 332
tumulosa, Proboscina, 119
tuomeyana, Vanikoropsis, 716
turbinatus, Favosites, 86

turbiniformis, Euconospira, 647

turgidus, um,
Cadulus, 581
Dielasma, 302
turritella, Solenospira, 653
typa, Paleanatina, 385
typicalis, Atactoporella, 128
typicus, a,
Climacograptus, 32
Paleacmeza, 606
Soleniscus, 699
typus,
Aurinea, 795
Phyllograptus, 29

uhleri, Lucina, 557
ulrichi, Dekayella, 132

umbellifera, Romingeria, 79
umbilicata, um,
Adeonellopsis, 170
Ecphora, 787
Endoptygma, 723
Helicotoma, 659
Trochonema, 669
Xenophora, 723
umbonatus, a,
Amboceelia, 343
Cyrtina, 313
Inoceramus, 443
Lingula, 198
Plethocardia, 416
Vanuxemia, 414
undabundus, Inoceramus, 442
undata,
Clionychia, 435
Cymella, 532
Grammysia, 383
Liopistha, 532
undosus, Pterinopecten, 493
undulatus, a,
‘Beatricea, 47
Eccyliomphalus, 663
Grammysia, 383
Orthonota, 378
undulostriata, Cyrtodonta, 410
unguiforme, Platyceras, 682
unicostata, Leptena, 226
unilineata, Terebra, 798
unionoides, Ischyrodonta, 416
unisulcata, Pentagonia, 360
universa, Orbulina, 10
utah, Pugnax, 2905
utahensis,
Cryptorhytis, 772
Cymbophora, 572
Fasciolaria, 772
Lima, 509
Planorbis, 819
uvasana, Meretrix, 564

vagrans, Trochonema, 670
valerius, Euomphalopteris, 630
vancouverensis, Nemodon, 404
vanuxemi,

Inoceramus, 444

Rhipidomella, 265

Spirifer, 320

Terebratella, 307
vanvleeti, Aviculopecten, 491
varia,

Constellaria, 136

Phyllodictya, 159
variabilis, Turritella, 734
varians,

Camarella, 271

Cystiphyllum, 64

Discosparsa, 167

Petaloconchus, 737

Vermetus, 737

INDEX OF SPECIES. 853

varicosus, um,
Cyclonema, 669
Spirifer, 325

varicus, Bilobites, 259

variolatus, Chonetes, 238

varistriata, Stropheodonta, 214

vaupeli, Nicholsonella, 136
velatus, Calyptraphorus, 752
vellicatus, Uncinulus, 293
venosus, a,
Retiolites, 34
Rhopalonaria, 116
ventralis, Saffordia, 385
ventricosa, um,
Barrandella, 276
Clorinda, 276
Cuspidaria, 532
Diaphorostoma, 679
Naticopsis, 674
Nucula, 396
Panenka, 389
Platyceras, 681
Whitella, 415
Wilsonia, 293
venustus, Favosites, 84
vera, Astartella, 536
vermilionensis, Pupa, 820
verneuili,
Anastrophia, 273
Phillipsastrea, 69
verneuilianus, um,
Chonetes, 238
Eridophyllum, 72
vertebroides, Turritella, 730
verticillata, Syringopora, 82
vertumnus, Pterinopecten, 493
vesicularis, Gryphea, 470
vesiculosum,
Clathrodictyon, 40
Cystiphyllum, 63
veta,
Caryatis, 564
Meretrix, 564
veternus, Planorbis, 817
vetulum, Campeloma, 727
vetustus, a,
Dendropupa, 821
Mesalia, 731
Planorbis, 819
Solemya, 375
Turritella, 731
Unio, 479
vibex, Nassa, 763
vicinus, a,
Chonetes, 236
Eotomaria, 643
vicksburgensis, Oculina, 103
virginiana,
Marginella, 788
Tellina, 567

virginicus, Vermetus, 738
vitruvia, Liospira, 641
vomer,
Grypheastrea, 465
Ostrea, 465
vomerium, Platyceras, 684
vulgaris, Cucullea, 405

wacoensis,
Kingena, 305
Lima, 509
wahtubbeanus, a,
Chlamys, 502
Pecten, 502
warrenana, Cymbophora, 573
washitaensis, Gryphea, 469
weatherfordensis, Exogyra, 473
weberensis, Aviculopecten, 490 *
wheeleri,
Schizodus, 483
Trachydomia, 674
whitei,
Camarotechia, 285
Lucina, 557
Turritella, 729
whitfieldi,
Acus, 799
Batostoma, 137
Diplograptus, 34
Hemiphragma, 137
Loxonema, 695
Nucula, 397
’ Plectorthis, 252
Pyropsis, 766
Streptaxis, 605
Terebra, 799
whitneyi, Peregrinella, 299
williamsi,
Natica, 716
Tellina, 567
wilsoni, Turbinella, 782
winchelli,
Batostoma, 136
Crenipecten, 495
Favosites, 85
wisconsinensis, Lophospira, 633
woodmani, Pachyphyllum, 70
woolworthana, Schuchertella, 229
wortheni,
Archimedes, 147
Stylodictyon, 41
wyomingensis,
Melania, 740
Pachychilus, 740

yandellanum, Loxonema, 694
yandelli, Amplexus, 59

ziczac, Naticopsis, 673
zippei,, Nodosaria, 10

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