The fossil turtles of North America

ee

aa

Soe

earn apareeaee

tins

ete

Se
Tate

it
Estey Zeiot sas

teeta see

Breas

=

Ps)

re ae
ae
ay a) al
ag
om
. a
ol)
a
Vie
‘
4 its

cr

a
oa ah
i
i
f ocr toy
.
i
‘
a=
i ' :
v
1 t a
: iv
f
-
{
:
1 ae :
AF
=x
i
.
es ,

imi

ag cht

ethos
ei

G8

—
n

'

es ee a
-

e
*
‘

ss iy VAN Be ae

iy
ae

ul
ab.

woke
ono

says
. ¥@s

RAY :
W poe AEE Nilpe he florea tesaady ff

a FOSSIL TURTLES

OF

meri AMERICA

BY

OLIVER PERRY HAY
l

WASHINGTON, D. C.
Published by the Carnegie Institution of Washington

1908

Th Cadbrt :

CarNEGIE INsTITUTION OF WasHINGTON, PusiicaTion No. 75

VA

A onian lay a>
A VASET ATION

STEJNEGER
COLLECTION
Natidriat NuseS77

ISAAC H. BLANCHARD COMPANY
NEW YORK

HAS
Copy ra

BRegiiles

7O 2

PREFACE.

In this treatise on the Fossil Turtles of North America there are described
266 species, of which 76 are regarded as hitherto unknown to science. In the
preparation of this work the writer has had access to most of the collections which
contain remains of North American fossil turtles. “The most important of these
collections is that of the American Museum of Natural History, in New York.
In this are found many of the specimens described by Professor E. D. Cope,
including many of his types. In addition to these, large numbers of turtles have
been brought together by the expeditions sent out by this museum during the past
fifteen years. Free access has been given the writer to the materials in the United
States National Museum, where There are many of the specimens described by
Dr. Joseph Leidy and Professor Cope; to those of the Academy of Natural Science
of Philadelphia, where are found other materials rendered precious by the labors
of the authors just mentioned; to those of the Carnegie Museum, Pittsburgh;
the Field Natural History Museum, Chicago; the University of Kansas, Lawrence;
the University of Texas, and the University of Nebraska. At Yale University
the writer has been permitted to study and describe valuable materials brought
together by Professor O. C. Marsh, besides other specimens which form the
types of species described more recently by Dr. George R. Wieland. ‘Thru the
courtesy of Professor W. S. Valiant some of Dr. Leidy’s types preserved at Rutgers
College were made accessible. Specimens for study have been sent to the writer
from most of the museums mentioned; also from the University of Chicago, by
Mr. S. W. Williston; from the University of California, by Dr. J. C. Merriam;
from the Geological Survey of Canada, by Mr. L. M. Lambe; and from the
Vanderbilt University, Nashville, by Professor L. C. Glenn.

It has been the author’s earnest wish to see all the types of the hitherto described
species; and most of these have come under his notice. Unfortunately some are
without doubt utterly lost; others have, for the time, disappeared from view.

The author has endeavored to illustrate as fully as possible the species described.
Whatever may prove to be the little or great value of the text, the writer can commend
the illustrations. By far the greater number of the figures of the plates are from
photographs which were taken at the American Museum of Natural History by
Mr. A. E. Anderson. Other photographs and drawings have been furnished by
the Geological Survey of Canada thru Mr. L. M. ibarielse3 others by Dr. George R.
Wieland, ence wale University Museum; others by Dr. W. J. Holland, director
of the Carnegie Museum, Pittsburgh. The photographs of Basilemys sinuosa
came from the Field Natural History Museum, thru Dr. E. R. Riggs. A consider-
able number of the drawings found in the plates were prepared many years ago,
for the late Dr. George Baur by the United States Geological Survey; thru the
courtesy of the Survey these were placed in the hands of ane writer. [he major-
ity of the drawings that appear in the text were executed by Mrs. Lindsay Mor-
ris Sterling, artist in the department of vertebrate paleontology in the American
Museum of Natural History. A number of these text-figures are the work of Mr.

Ill

Vi : PREFACE.

R. Weber, of the same museum. Most of the wash-drawings that appear in the
plates were produced by Mr. Erwin C. Christman of the American Museum of
Natural History.

The thanks of the author are due, first of all, to the Carnegie Institution of
Washington for the support it has given him in the preparation of this monograph;
in the next place, to Professor H. F. Osborn, of the American Museum of Natural
History, New York, for the opportunity to use the materials in that museum;
finally, to all the persons and institutions above mentioned and others who have
contributed in any way to whatever there may be of value in this work.

It is not believed to be necessary to append a list of the papers and memoirs
consulted in the preparation of this monograph; inasmuch as the writer’s Bibliog-
raphy and Catalogue of the Fossil Vertebrata of North America, Bulletin 179 of
the United States Geological Survey, records the literature of the subject up to the
year 1901 and the important writings since published are cited in the text of this
monograph.

WasHINGTON, November 20, 1907.

THE FOSSIL TURTLES OF NORTH AMERICA.

ON THE SOURCES OF OUR KNOWLEDGE OF THE FOSSIL TURTLES OF
NORTH AMERICA.

The study of the fossil turtles of North America began in 1851, when Dr.
Joseph Leidy described, under the names Stylemys nebrascensis, Testudo lata,
Emys hemispherica, and Emys oweni, the extremely common fossil turtle of the
Oligocene Badlands of the present state of South Dakota, then a part of the Terri-
tory of Nebraska. It is true that in 1842 Dr. Richard Harlan had described and
figured (Amer. Jour. Sci., xim, p. 144, pl. 1, figs. 2, 3) as Chelonia couperi a bone
which he believed to be the femur of a large sea-turtle; but it is quite certain that
the bone was no part of any turtle. Dr. Leidy continued at intervals up to 1889 to
describe new species of fossil turtles. Most of Dr. Leidy’s shorter papers appeared
in the Proceedings of the Philadelphia Academy, but his most important illustrated
works on the subject are found in D. D. Owen’s Geological Survey of Wisconsin,
etc., 1852; in the sixth volume of the Smithsonian Contributions to Knowledge,
1854; and in the first volume of the monographs of Hayden’s Geological Survey
of the Territories, 1872. Professor E. D. Cope began his publications of species
of fossil turtles in 1867; his last paper containing matter on the subject was pub-
lisht in 1899, after his death. His papers on the subject are numerous and will
be found cited in the writer’s Bibliography and Catalogue of the Fossil Vertebrata
of North America, 1902. Cope’s most important expositions of the turtles are to
be found in the fourteenth volume of the Transactions of the American Philosophical
Society, 1869 and 1870; in the second volume of the Hayden Survey monographs,
1875; in volume four of Wheeler’s Survey West of the rooth Meridian, 1877; and
in the third volume of the monographs of the Hayden Survey, 1884.

Professor O. C. Marsh described only three species of fossil turtles. No new
fossil species are to be credited to Dr. George Baur, but he was the author of a
number of papers which made important additions to our knowledge of their
structure and relationships. Dr. S. W. Williston and Dr. E. C. Case have con-
tributed a number of valuable papers on the subject, especially on the turtles
derived from the Niobrara beds of Kansas. Dr. George R. Wieland has given
especial attention to the marine turtles of the Upper Cretaceous; and, especially,
he has described that remarkable chelonian monster Archelon ischyros.

Other authors who have busied themselves more or less with the North American
chelonian population of past times are J. Z. Gilbert, L. M. Lambe of the
Canadian Geological Survey, Dr. F. B. Loomis, W. J. Sinclair, E. S. Riggs, and
O. P. Hay. The results of the studies of the authors mentioned are that more than
260 species of fossil turtles are now known from the geological deposits of North
America; the nearly complete structure of a considerable number of these has
been determined and much of that of others; and much light has been gained
regarding the history and relationships of the members of the order. Undoubtedly
many additional species will be discovered as the years pass away and species now
known only from a few bones will become far better known.

2 FOSSIL TURTLES OF NORTH AMERICA.

ON THE OSTEOLOGY OF THE TUR TEES:

The turtles, or tortoises, form an order of the great class of reptiles; and they
probably constitute the best defined of all the orders of that class, no member of
the group having yet been discovered about whose chelonian affinities there need
be any dispute, in case the animal 1s represented by enough of its skeleton, and
nearly every bone of a turtle is so characteristic that its neloman nature is evident.

It is generally supposed that the most characteristic thing about a turtle is the
fies PRR ERAOT of the bones of the body walls into a sort ie box, into which the
animal can withdraw its head, legs, and tail. However, no one would mistake the
relationships of the leatherback (eat: helys), altho little more than a crocodile
or a cayman does he possess a box into which he can withdraw his exposed members.
It is rather the broad, relativ ely short body of these animals, the small head on a
more or less elongated neck, and the toothless, horn-covered jaws that stamp these
animals as turtles.

Of turtles existing at the present day there are somewhat more than 200 species.
Dr. George A. Boulenger, in his Catalogue of Chelonians (1889), estimated the
number at 201 species, and a number of others have been deseahed since that
time. They inhabit all the continents and all parts of the continents that are not
too cold nor too dry for them. Many islands, even some, as the Galapagos, far
removed from continental bodies of land, possess or have possest their species.
All the warmer seas are visited by pelagic turtles, of which there are at least 5
species. Even dry and hot deserts may support their peculiar forms of these
animals. The geographical distribution of the living species will be discust on
another page. The geological history extends back into the middle Triassic; and,
with little doubt, turtles existed in the Permian.

THE EMYDID/E. THE TERRAPINS.

For the information of the reader a general description will here be given of the
osteology of members of the principal groups of turtles. We shall begin with the
shell of one of the Emydidz, a central el of the order. This belongs to the
geographic turtle (Graptemys geographica), an inhabitant of the lakes and larger
streams of the Mississippi Valley. The shell reaches a length of at least 225 mm.
and is only moderately archt. In this case, as in the great majority of the members
of the order, it forms a box into which the head, legs, and tail can be retracted.

The shell consists of two parts, an upper, the carapace (fig. 1), and a lower, the
plastron (fig. 2). On each side, between the fore and the hind leg, the two portions
are joined by the bridge. The carapace is composed of 50 bones, each of which
is articulated by jagged sutures with the adjoining bones. In front and behind
the bridges, the outer ring of bones projects freely like the eaves of a roof. “Twelve
of the bones of the carapace are arranged in a row along the midline. In front is
the nuchal bone (nw. p). Behind this comes a series of 8 neurals (n. 1, 1. 2, etc.).
The last of these is followed by two suprapygals (spy, 1, 2), and the hindermost of
these is succeeded by the pygal (py), forming the last oi the median series. The
8 neurals are connected with the neural arches of the dorsal vertebrae, of which
they appear to be mere expansions. The nuchal, the suprapygals, and the pygal
are not connected with the vertebre.

On each side of the row of neurals and articulating with them are 8 costal plates,
or -costals-(e-p, I, 2, etc.). These appear to be only expansions of the ribs; and
study of the embryology shows that they are connected with the ribs from the

earliest appearance of the bone. Nevertheless, there are reasons for believing that

OSTEOLOGY. g

originally the costals and the neurals were distinct from the ribs and neural spines.
Outside of the costals, extending on each side of the body from the nuchal to the
pygal, is a series of 11 bones, the peripherals, often-called the marginals (1, 2, etc.,
_ on the left side of fig. 1).

Fig. 2 represents the plastron of the same shell. It consists of a median bone,
the entoplastron (ent) and four pairs of bones, the eprplastra (epi); the hyoplastra
(hyd); the hypoplastra (hypo); and the xiphiplastra (xiph). On each side, between
the fore and the hind leg, the hyoplastron and the hypoplastron articulate with
peripherals 3 to 7 inclusive to form the bridge. The free borders of the epiplastra
are modified so as to produce a sort of lip. “Fhe-rear-of the plastron is notcht.
The notch from which the front leg protrudes is the axillary notch, that from which
the hind leg emerges is the inguinal notch. That portion of the plastron in front
of the axillary notches is the anterior Jobe, that behind the inguinal notches is the
posterior lobe.

Figs. 1 and 2. Graptemys geographica. X}.

1. Carapace. c. p.1,c. p.2, etc., the costal plates, or bones; c. s. 1, c. s. 2, etc., the costal scutes; m. I, m. 2, etc.,
the neural bones; nu. p, the nuchal plate, or bone; nu. s, the nuchal scute; py, pygal bone; spy, suprapygal
bone; spy. 2, second suprapygal; v. s. 1, v. s. 2, etc., the vertebral scutes; 1,2,3, . - . - 12,0n the right
side, the marginal scutes; I,2,3,.-..- - 12, on the left side, the peripheral bones.

2. Plastron. ab, abdominal scute; an, anal scute; ent, entoplastron; ep/, epiplastron; fem, femoral scute; g, gular
scute; hum, humeral scute; hyo, hyoplastral bone; hypo, hypoplastral bone; im, inguinal scute; py, pygal bone;
xiph, xiphiplastron; 1, 2,3, . . - - 12, on the right side, the marginal scutes; 1, 2,3, .-. - . 11, on the
left side, the peripheral bones.

Just behind the axillary notch the hyoplastron sends upward a stout process,
the axillary buttress, to fit into an excavation in the third peripheral and the inside
of the lower end of the first costal. Just in front of the inguinal notch the hypo-
plastron sends up a similar process, the inguinal buttress, which fits into an excavation
in the seventh peripheral and the inside of the lower end of the fifth costal. The
space on the inside of the shell between the axillary and the inguinal buttresses is
called the sternal chamber.

Seen from below, each costal plate presents a broad ridge along the middle.
This is the true rib; and at the end of the costal this rib enters a pit in one of the
peripherals. In this species the peripherals over the bridges are not suturally
joined to the costals. At their upper ends the ribs again free themselves from the

4 FOSSIL TURTLES OF NORTH AMERICA.

costals as rib-heads, which articulate with the vertebral centra. At the front of the
shell each rib-head articulates with two centra, at their junction with each other;
more posteriorly, the rib-head falls farther and farther behind the intervertebral

articulation. There is no movement of the rib-heads on the centra, nor of these on _

one another.

The first dorsal vertebra articulates with the last cervical, permitting a very
free motion. Its ribs are short, have no costal plate, and lie closely joined to the
front of the rib of the first costal plate. From this it will be seen that the second
rib has coalesct with the first costal plate, the third rib with the second costal, and
soon. The tenth dorsal rib is short and slender; its distal end is consolidated with
the eighth costal plate, and has the upper end of the ilium abutting against it.

In life the bones of the carapace and the plastron are covered by a number of
horny plates, the scutes. Where the edges of any two of these meet they impress a
furrow in the bone, forming a sulcus. When the skeleton is prepared the scutes
fall off, but the sulci remain to betray the number and form of the scutes. In the
figures here shown (figs. I, 2), as in nearly all the figures of this work, the sulci are
represented by stippled bands; the sutures between the bones, by zigzag lines.
In fig. 1 the scutes are represented on both sides of the shell, but the symbols of
the names are placed only on the right side. Immediately in front, at the midline,
there is a small seute, the nuchal (nu.s). “Then comes a row of five large scutes,
the vertebrals (J. 1, ¥. 2, etc.), each extending out beyond the neural bones. The
sulci separating these seutes cross respectively the first, third, fifth, and eighth neu-
rals. On each side of these vertebrals is a row of four large seutes, the costals(c.-s,
I; eS, 2; etc.). The sulci between these descend respectively on the second,
fourth, sixth, and eighth eostal bones.

The borders of the carapace are invested by a series of marginal seutes, twelve
on each side (f, 2,3, etc., on-right side). The sulci dividing these from the costal-
scutes run along near the upper border of the peripheral bones. At the free borders
of these peripherals the scutes turn down and appear on the under sides of the
bones. “* fe her

It will be observed that the scutes coincide neither in number nor position with
the underlying bones. It is seldom that the sulci follow the sutures. ‘This matter
will be discust hereafter.

In fig. 2 are represented the plastral seutes, the characters indicating the names
appearing in the right side of the drawing. A median longitudinal suleus runs
from the front to the rear of the plastron, separating the-scutes of each pair. In
front is a pair of gular seutes (g)s then a pair of humerals (hum); followed by the
pectorals (pec), the abdominals (aby, the femorals (fem), and finally, by the anals
(an). Just behind each axillary notch is an axillary seute; while just in front of
each inguinal notch is found an inguinal scute. .“The marginal seutes-seen in this
figure-are the same that appear in fig. I.

We may now examine the vertebrz in front of and behind the dorsals. In all
of the turtles there are normally 18 presacral vertebra, of which 8 belong to the
neck. The more anterior and the more posterior cervicals are the shorter. The
neck as a whole is about as long as the dorsal series of vertebrae. ‘The first is com-
posite, consisting of four distinct pieces. On each side is a neural arch, aiding in
forming the neural canal. Below, these abut on a median piece, the hypocentrum.
These three bones unite in forming a concavity, into which fits the ball-like occipital
condyle. Behind the arches and the hypocentrum 1s the odontord process, the proper
centrum of the first cervical. Behind, this articulates with the centrum of the
second cervical but does not become anchylosed with it.

—y>

AT pi

Res

OSTEOLOGY. 5

Of the other cervicals the arches are separable from the centra along a line of
cartilage. The neural arches are all low and devoid of spines. There are no
lateral processes. As regards the articular ends of the centra, there is great diversity.
In Trachemys scripta, the second and third are convexo-concave; the fourth and
the eighth are convexo-convex; the fifth is concavo-convex; and the seventh, concavo-
concave. The articulations between the fifth and sixth, the sixth and the seventh,
and the seventh and the eighth are extended from side to side and divided medially,
forming a true hinge joint, which permits very free motion up and down, but
restricts it from side to side. The anterior and the posterior zygapophyses are
little elevated above the centra and are placed far apart. ‘These arrangements
contribute to free motion in a perpendicular plane, but limit it in a horizontal.

Behind the last dorsal vertebra come two sacrals. Their ribs expand distally
and articulate with the upper ends of the ilia. The sacrals are followed by a number
of caudals, about 15, but varying with the species, or even in individuals. Most
of these have transverse processes.

The skull of Trachemysscripta seen from above (fig. 3) presents three pairs of
bones which join at the median line. In front are the prefrontals, extending back-
ward to the middle of the orbits. The anterior ends roof over the nasal cavity.
A strong process descends from each to join the vomer and the palatine, and to
form the front wall of the orbit. Behind the prefrontals are placed the larger
frontals. “Vhey aid in forming the rim of the orbits. The parietals are important
bones, inasmuch-as they form the roof and much of the lateral walls of the brain-

case. The anterior end of each sends downward a strong process which joins the
pterygoid. Besides the pterygoid, the lower border of the parietal articulates with
the prootic and the supraoccipital. he latter bone is greatly prolonged backward,
as it is in almost all turtles. It forms a small part of the boundary of the foramen
magnum.

The maxilla bounds the nasal cavity on the side, the orbit below, and its lower
border forms an acute cutting-edge. In life this edge is covered with a horny
sheath. Posteriorly the maxilla articulates with the jugal. ‘The hinder part of the
rim of the orbit is formed of the jugal below and of the postjrontal above. ‘These
two bones form a postorbital bar of moderate width.

A large tympanic cavity is excavated in the quadrate,-an-extremely important
bone among the reptiles. Below the cavity mentioned, the quadrate descends to
form a movable articulation with the lower jaw. In the hinder border of the quad-
rate is a small, but deep notch for the passage of a long, rod-like bone, the columella.
Interposed between the anterior border of the quadrate and the jugal bone is the
quadratojugal. “Vhe jugal and quadratojugal form the zygomatic arch. Above
and behind the quadrate 1s the squamosal.

The sides of the hinder part of the skull are occupied each by a long excavation,
the temporal fossa. he floor of this is formed of the parietal on the inside, of the
prootic,and paroccipital in the middle, and of the quadrate and squamosal on the
outside.

Fig. 4 represents the skull of the same species as seen from below. In front are
the premaxille, bounding the nasal cavity below and entering into the roof of the
mouth. On each side and behind the premaxilla is the maxilla. It presents out-
wardly the cutting-edge already mentioned. Its inner border joins, in front, the
vomer, posteriorly the palatine; the middle portion is mostly a free edge, forming
the lateral boundary of the choana.. Between the two borders is a broad triturating,
or alveolar, surface, which in life is covered with a horny sheath. Along the middle
of this, parallel with the cutting-edge, is a sharp ridge, slightly tootht.

6 FOSSIL TURTLES OF NORTH AMERICA.

The midline behind the premaxillz is occupied by the single vomer. Anteriorly
it divides the nasal passages from each other; laterally it articulates with the
palatines; posteriorly, with the pterygoids. The palatines assist in roofing the
nasal passages and in forming the triturating surface mentioned. Between each
and the maxilla of its side is seen an opening, the posterior palatine foramen.

The pterygoids meet each other at the midline anteriorly, but posteriorly are
separated by the basisphenoid. ‘They extend backward so far as to exclude the
bone last mentioned from contact with the quadrates. The lateral border of each
pterygoid is mostly a sharp free edge. Behind the basisphenoid comes the bastocci p1-
tal. It is joined on each side by the exocci pital, and all three of these bones join in
forming the occipital condyle. From this view is seen also a portion of the par-
occipital and squamosal. On each side of the basicranial axis are seen foramina
for the passage of various nerves and blood-vessels.

Each ramus of the lower jaw is composed of six bones. In front 1s the dentary,
furnishing the triturating surface of the jaw, covered above with a horny sheath, and

WwW

Figs. 3 and 4. Trachemys scripta.

3- Skull seen from above. X1. fr, frontal; ju, jugal; pa, parietal; paoc, paroccipital; pfr, prefrontal; pof, post-
frontal; pro, prootic; gu, quadrate; sg, squamosal; soc, supraoccipital.

4. Skull seen from below. 1. a/v, alveolar surface of maxilla; boc, basioccipital; bsp, basisphenoid; exc, exoc-
cipital; mx, maxilla; pal, palatine; paoc, paroccipital; pmx, premaxilla; pro, prootic; pt, pterygoid; qu. art,
articulation of quadrate with lower jaw; gj, quadratojugal; sg, squamosal; vom, vomer.

completely co-ossified with its fellow of the opposite side at the symphysis. On the
lower border of the jaw this bone extends backward nearly to the articulation with
the quadrate. The upper border of the jaw, behind the triturating surface, is formed
in front by the coronord bone; posteriorly by the supraangular. These two bones
are to be seen both from the outside and from the inside of the jaw. Behind the
supraangular is a nodular bone that articulates with the quadrate, the articular.
On the inner surface of the jaw, near the hinder end, are two bones, whose names
are in dispute. Baur (Anatomischer Anzeiger, x1, 1896, p. 413) calls the lower of
the two the splenzal, the upper the angular.’ Williston (Science, XVIII, 1903, p. 830)
regards the lower bone as the angular, the upper as a dermal articular. The same
author has, in his work on North American Plesiosaurs, 1903, page 30, called the
latter bone the prearticular, and this name is adopted by the present writer.
The shoulder-girdle of an emyd turtle consists of two bones on each side. One
of these, the scapula, consists of two slender portions placed at nearly a right angle
with each other. The longest portion, the proper scapula, the body of the scapula,

OSTEOLOGY. 7

extends from the glenoid cavity, of which it furnishes more than half, upward and
inward, to become ligamentously attacht to the upper end of the first costal plate.
The other part of this bone ‘extends from above the glenoid cavity inward and
forward, to be attacht by ligament to the entoplastron. This process has been
variously interpreted, but here it is regarded as the procoracoid, which has become
co-ossified with the scapula. It will be called the procoracoid process. For a dis-
cussion of this subject and a list of writers who have considered it the reader is
referred to a paper by Max Furbringer in Jenaische Zeitschrift, xxxtv, 1900.
The other bone of the girdle is the coracord. It starts from the glenoid cavity,
and proceeds inward and slightly backward, to approach closely its fellow at the
midline.

The writer regards the chelonian limb as belonging to a relatively primitive
type. If the reader will peruse Huxley’s chapter on the position of the limbs, in
his Anatomy of Vertebrated Animals (Appleton’s edition, 1872, p. 33), and com-
pare his statements with what he can see in the limbs of a turtle, he will probably
agree with the view here presented. ‘The apex of the angle at the elbow, instead of
being directed backward, is rather directed forward and upward. ‘There is no
crossing of the ulna and radius.

The humerus of the emyd is rather strongly bent in the plane passing through
the axes of the three segments of the limb. The head is directed upward. The
strongly developt tuberosities for attachment of muscles, the radzal, or lateral, and
the ulnar, or medial, are bent toward the lower face of the bone. The ulnar is
always the larger. At the distal end of the bone, on the anterior or radial side, is a
passage for the radial nerve, the ectepicond ylar joramen.

Of the two bones of the lower arm the radius is the smaller. It has a shallow
cavity at the proximal end that meets the articular end of the humerus. Its distal
end is expanded and articulates with the intermedium and the radtocentrale of the
carpus. he ulna is the stouter bone, is flattened, has the suggestion of an olecranon
process, and articulates distally with the imtermedium and the ulnare.

The carpus is simple. Besides the bones already mentioned as belonging to the
carpus, there is another in the proximal row, on the outer side of the ulna. There
are 5 bones in the distal row, but sometimes the fourth and the fifth are co-ossified.
“There are 5 metacarpals, each of medium length. The digits are 5 in number, the
first and the fifth the shortest. “Vhe first digit has 2 phalanges, the others 3 each,
exactly as in the Mammalia.

The pelvis is broad and short, and each half is composed of 3 bones, all of
which take part in the formation of the acetabulum. The ilium is expanded antero-
posteriorly above and is articulated with the outer ends of the sacral ribs. The
middle of the bone is slender. Each rschium has a posterior process which rests
on the xiphiplastron and an anterior process which runs forward to join the pubis
of its side. There is thus produced on each side a large heart-shaped fontanel,
the ischio-pubic foramen. Each pubis has a lateral process which rests on the
xiphiplastron. The pubis is prolonged forward considerably, and between the two
there is a median notch which in life is filled with cartilage, the prepubic; but this
does not become ossified.

The femur resembles considerably the humerus; but it is a longer bone and
there is no perforation corresponding to the ectepicondylar foramen. ‘The head is
larger and of different form. The trochanters are of about the same size and the
digital fossa separates them far down. The tibia is a stouter bone than the fibula.
Its upper end is the larger and presents a large surface for articulation with the femur.
The lower end has a saddle-shaped articular surface to join the large bone forming

8 FOSSIL TURTLES OF NORTH AMERICA.

the first row of the tarsus. The fibula is slender, with the broader end downward,
articulating with the same bone as does the tibia. The bone of the tarsus just
foaoncdk is the only one present in the upper row, and is regarded as representing
three bones that theoretically belong in the upper row, Reece the centrale. In the
lower row of tarsal bones there are five present, all articulating above with the
large bone of the upper row and distally each with one of the Cena. The
fifth of these bones is peculiarly expanded in the turtles.

The 5 metatarsals are rather elongated in Graptemys and Trachemys, as are,
too, the phalanges. In the first digit howe are 2 phalanges; in each of the others, 3.
All the terminal phalanges are invested in horny claws, except the fifth.

THE CHELONIID/E. THE SEA-TURTLES.

Some of the salient features of the Cheloniidz will now be described. ‘These
constitute a family of the Cryptodira, a superfamily to which also the Emydidz
belong. The Cheloniidz are greatly different in some respects from the Emydide.
The shell is composed of the same elements, but many are less completely developt.
In general, the border of the carapace is excavated in front for the neck; and on
Each side of this for free movement of the fore limbs. Behind, it is nemreds so
that in form the carapace is somewhat heart-shaped. The costal plates fall short
of reaching the distal ends of the ribs, as a result of which open spaces, or fontanels,
are left between the costals and the peripherals. Usually none of the costal plates
come into contact with the peripherals. The ribs of the costals, however, reach
these bones and each enters a pit in a corresponding peripheral. In the loggerhead
(Caretta caretta), for example, rib-ends enter peripherals 3 to 8 inclusive and
peripherals 10 and 11. In some forms, as Lepidochelys, there are supernumerary
bones interposed among the neurals, so that the number of these seems to be as
high as 14.

The carapace is furnisht with scutes similar to those of the Emydidz. In
Caretta and Lepidochelys there is a supernumerary costal scute in front of the
normal first.

Altho the plastron of these turtles is composed of the same elements as that of
the Emydidz, some of these are greatly modified. The hyoplastra and the hypoplas-
tra are not suturally connected with the peripherals of the bridge; nor do the
plastral bones just named come into contact with their fellows at the midline, so
that the space between the bones of the right and of the left sides is occupied by a
great fontanel. On each side there is another fontanel inclosed by the bridge
peripherals, the outer end of the hyoplastron, and that of the hy poplastron. The
inner and the outer borders of the two sets of bones last mentioned send out a
number of digitations into the fontanels. The epiplastra are saber-shaped bones
which join each other and the entoplastron at the midline, without jagged sutures;
and their distal ends are applied to the outer border of the corresponding hyo-
plastrals. The xiphiplastra are narrow, curved bones that approach each other
at their distal ends.

Carapaces and plastra similar to those of the Cheloniide are found among the
Thalassemydidz, and to these the reader is referred for illustrations.

The neck of the Cheloniidz is much shorter than that of the Emydidz and the
head can hardly be retracted within the shell. In the loggerhead the neck is but
little more than half as long as the series of dorsal vertebrae. The eighth cervical
articulates by a synovial surface with the inferior side of the nuchal bone. The
series of caudal vertebrz is short.

OSTEOLOGY. 0)

The skull of the Cheloniidz differs in some important respects from that of the
Emydidz. In order to illustrate this, figures are here introduced giving upper
(plate 1, fig. 1), lower (plate 1, fig. 2), and lateral (plate 2, fig. 1) views of the skull
of Lepidochelys kempi Garman. These figures were prepared for Dr. George Baur,
in 1888, but reverted to the United States Geological Survey, the then director of
which, Dr. C. D. Walcott, has permitted them to be used here. No figures of
this species have hitherto been publisht. he most interesting feature of the
skulls of the sea-turtles is the great extent of the bony roof covering the temporal
region. This roof extends from the orbit to behind the plane of the occipital con-
dyle. The postfrontal bone, narrow in the emyds, is carried backward nearly to
the hinder border of the roof. he squamosal sends upward and inward a plate
that meets a horizontal plate from the parietal, forming a parieto-squamosal arch.

‘The lower side of the skull is interesting
chiefly because of the broadening of the triturat-
ing surfaces of the jaws. The palatal plates of
the vomer extend backward until they meet
similar plates from the palatines. The choane
are thus thrown much farther toward the middle
of the skull than in the skull represented by text-
figure 4. The crushing surfaces of the lower
jaw are correspondingly widened (plate 1, figs.
3 and 4). In the Thalassemydide the choane
may be pusht much further backward, as ma
be seen by examining the skull of Rhetechelys
platyops (Cope). There are no posterior palatine foramina.

In the Cheloniidz the procoracoid process makes an obtuse angle with the body
of the scapula, and there is a distinct neck between the process and the glenoid
fossa. The coracoid bone is longer than the scapula and moderately expanded at
its free end. hese bones are represented by fig. 2 of plate 2.

The humerus of these sea-turtles is strongly modified from the primitive form.
It is much straighter than that of the Emydide and has become flattened in the
plane of the distal end. ‘The head and the radial and ulnar tuberosities have changed
positions. The head is turned downward and proximad into the plane of the bone,
while the tuberosities are lifted into this plane, each on its proper border of the bone.
The radial tuberosity is carried along on the shaft of the bone until it has lost its
connection with the head. It becomes divided into two parts, one for the deltoid
muscle, the other for the supracoracoid. Fig. 3, plate 2, represents the humerus of
Lepidochelys as seen from above; fig. 4, as seen from below.

Relatively to the humerus, the radius and the ulna are shortened, the ulna
more than the radius. In the carpus the radiale remains small, the intermedium
and the ulnare are enlarged and flattened, while the centrale is distinct. There are
five bones in the distal row, one articulating with each metacarpal. The third and
the fourth may be co-ossified. On the ulnar side of the carpus there is a large flat
bone assisting to broaden the carpus. It may be regarded as the pisiform.

The second, third, and fourth digits are greatly elongated, the bones flat-
tened, and all are bound together in a mass of muscles and skin to form an undivided
oar. The first, and in some cases the second, digit is provided with a claw.

The pelvis of the Cheloniidz is broad and deprest (fig. 5). The ilia are short;
the upper end is slender and turned backward and the axis of the bone is nearly
in the plane of the pubes. The latter bones are broad. Between the two, at the

Fic. 5.—Caretta caretta. Pelvis from
below. x.

10 FOSSIL TURTLES OF NORTH AMERICA.

midline in front, there is a deep notch, filled in life by the prepubic cartilage. The
lateral processes are broad. The ischia are without posterior lateral processes, and
they are not connected with the pubes on the midline by bone; thus the ischio-
pubic foramina unite into one in the prepared skeleton.

The femur, which in the emyds is longer than the humerus, 1 is, in the sea-turtles,
shorter than the latter element. The shaft is not so straight as is that of the humerus
and the head is not so much deflected toward the axis of the shaft. “The trochanters
differ considerably in size and the digital fossa does not descend far between them.
The tibia and the fibula are relatively stout bones. While in the emyds described
above, the two upper segments of the fore limb are considerably shorter than the
corresponding segments of the hinder, the reverse is true in the Cheloniide. Figs.
5 and 6 of plate 2 represent the femur of Lepidochelys.

The hinder foot of sea-turtles is, compared with the fore foot, greatly reduced.
In Caretta the hinder foot, including the tarsus, is only about half as long as the
fore foot. There are 2 bones in the first row of the tarsus, 5 in the second row.

THE TRIONYCHOIDEA. THE SOFT-SHELLED TURTLES.

We will give our attention now to members of another superfamily, the din=
ony choidea, popularly known as soft-shelled turtles, sometimes as mud-turtles, or
river turtles. ‘Vhe two last-mentioned names are, however, often applied to other
groups of turtles.

In these, as in other turtles, there is a carapace and a plastron; but they differ
greatly in appearance from those of the emyds. The whole body is greatly deprest.
For illustrations of these portions of the shell the reader may consult the figures of
the fossil species on succeeding pages. The carapace is usually composed of neurals,
7 or 8 in number, 7 or 8 pairs of costals, and a nuchal bone. Only in one genus,
Trionyx (Emyda Gray), including two Asiatic species, are there any suggestions of
peripherals. ‘The costal bones are closely articulated to their neighbors and the
contiguous neurals; but often these costals do not extend to the eae of the ribs;
or, if they do, it is only in very advanced age. In life the periphery of the shell is
surrounded by a rim of dense and flexible connective tissue, terminating all round
in a sharp edge. It is this rim that has suggested the name soft-shell.

The whole upper surface of the carapace is ornamented with a network of
ridges which inclose pits of various forms. The size and arrangement of the ridges
and pits vary in the different species. There are never any traces of horny scutes,
the outer skin always remaining soft.

The plastron in some respects resembles that of the sea-turtles, inasmuch as
there are median and lateral fontanels and the connection with the carapace 1s
a ligamentous one. The hyoplastra and the hypoplastra are furnisht with median
and lateral digitations. Of the median digitations one belongs to each hyoplastron
and is directed forward and inward, to come into contact with the entoplastron.
Two belong to each hypoplastron, one being directed toward that of the opposite
side, the other toward the xiphiplastron. Of the lateral digitations one set is
directed from each hyoplastron forward and outward, the other from the hypo-
plastron backward and outward. The hyoplastron and the hypoplastron of each
side are closely sutured together, in some cases co-ossified.

The entoplastron is V- shaped, the apex being directed forward, an arm resting
against the hyoplastron of each side. The epiplastral bones are slender and curv ed,
usually not in contact with each other at the midline. They differ from these
bones in all other turtles in being excluded from contact with the hyoplastra by
the arms of the entoplastron.

OSTEOLOGY. II

The xiphiplastra are usually more or less curved bones, whose anterior ends
interdigitate with the hypoplastra, while their posterior ends meet at the midline.

In some cases the plastral bones are smooth and devoid of ornamentation. In
many other cases there are developt on their lower surfaces patches of more super-
ficial bone, the callosities. “These callosities are sculptured into pits and ridges,
somewhat like the bones of the carapace, but the pattern may be different. Each
callosity may occupy but a small part of the bone developing it or it may extend
over the whole bone. The callosities are more extensive in the Cretaceous and
Tertiary species than in those now existing.

The best description of the plastral bones of living Trionychide has been
publisht by Dr. Friedrich Siebenrock (Sitzungsber. Akad. Wiss. Wien, CXI, 1902,
pp. 807-846).

In the Plastomenide the median fontanels are filled up; and the whole lower
surface of the hyoplastra, hypoplastra, and the xiphiplastra is sculptured.

The neck of the soft-shelled turtles is long and slender, and, like that of the
Cryptodira, it bends most freely in a perpendicular plane. Ina specimen of Platy-
peltis spimifera at hand all the centra are convex in front, concave behind, except
that the hinder end of the eighth is reduced to a thin edge. ‘This cervical is con-
nected with the first dorsal almost wholly by the zygapophyses.

The skull of the soft-shelled turtles presents many distinctive features. Fig.
1, plate 3, represents that of Platypeltis ferox, a Florida species, seen from above;
fig. 2, plate 3, the same skull as seen from below. The skull is elongated and pointed
in front. ‘The posterior region is notable for the three large backwardly directed
processes, the supraoccipital and the two squamosal processes. Of the temporal
roof there is no part except the postorbital and the zygomatic bars. The prootic
extends much in front of the articulation of the lower jaw. The hinder border of
the pedicel of the quadrate is closed behind the stapes, so that this occupies a canal,
instead of a notch. The premaxille have coalesct into a single small bone. Seen
from below, the skull presents in front a median prepalatine foramen and the two
choanz. Altho the latter open rather far backward, they are not underfloored by
yomerine, palatine, and maxillary plates. The triturating surfaces of this species
are rather broad. The vomer is always small. The palatines meet throughout
their length at the midline, and posteriorly they articulate with the basisphenoid.
The pterygoids are broad, run backward alongside the basioccipital, and do not
meet on the median line. The basioccipital and the exoccipitals all take part in
the occipital condyle. The paroccipital is a large bone.

The lower jaw (plate 1, fig. 5) 1s composed of the same elements as that of the
emyds. The coronoid bone is large and the angle of the jaw projects considerably
behind the articulation with the quadrate.

The hyoid apparatus is strongly developt.

In order to accommodate itself to the flattened form of the body, the scapula 1s
directed from the glenoid fossa upward, forward, and inward, making an angle of
about 50 degrees with the procoracoid process (plate 3, fig. 3). The latter is slightly
expanded toward its distal end and flattened. The coracoid is broad and flat and
somewhat saber-shaped.

The humerus (plate 3, figs. 4, 5) is a stouter bone than that of the emyds above
described, and it is less neatly modeled. The proximal tuberosities, the radial and
the ulnar, are larger, with a broader fossa between them. The ectepicondylar passage
is a groove. The radius is half the length of the humerus; the ulna is still shorter.

The fore foot is as long as the humerus, a condition due to the elongation of
especially the median digits. The three on the radial side have claws, the others

12 FOSSIL TURTLES OF NORTH AMERICA.

do not. The phalangeal formula of the first three digits is 2, 3, 3, as in Emydide.
The fourth may have 4, 5, or 6, while the fifth finger may have 3 or 4 phalanges.

‘The pelvis resembles much that of the Chelonide: but the opening representing
the united ischio-pubic foramina is larger. ‘The ilium is short and slender and
the upper end is turned backward. ‘The ischia have short posterior processes.

The femur (plate 3, figs. 6, 7) is shghtly longer than the humerus, which it
resembles considerably. It may be distinguisht by its having no ectepicondylar
groove and by the narrower, more elongated, head. The trochanters are wide
apart and wholly separated by the interdigital fossa.

The tibia is a stout bone nearly three-fourths as long as the femur. As in other
turtles, the tibia is a slenderer bone. ‘The hinder foot 1s still more elongated than
the anterior, that of P. spinifera being more than a third longer than the femur.
The first three digits have the same number of phalanges as other turtles; that is
2, 3, 3.. The fourth digit may have 4 or 5 phalanges; the fifth, 2 or 3. The first
three have claws.

THE PLEURODIRA. THE SNAKE-NECKT, OR SIDE-NECKT TURTLES.

It is necessary to make some observations on the osteology of the members of
another superfamily, the Pleurodira. The shell is composed of the same elements
as in the emyds and often presents no important differences from that of the latter.
There are genera in which the neurals are reduced in number and a few in which
these bones have been wholly supprest. In a few living genera and in some
that are extinct there is present a pair of bones, unknown in the Cryptodira and
Trionychoidea, the mesoplastrals, interposed between the hyoplastrals and the
hypoplastrals. In Pelustos (Sternotherus) these bones join across the plastron.
In Pelomedusa they are small triangular bones occupying the middle of the bridge
only. The same bones occur in the species of Baéna; and the reader may consult
the figures under that genus.

The shell of all Pleurodira differs from that of other turtles in forming sutural
connections with the pelvis. The eighth costal plates develop each a sutural surface
for the upper end of the illum. On each of the xiphiplastrals are two sutural scars,
the anterior for union with the pubis, the posterior for union with the ischium.
On other pages will be found figures of the species of Taphrosphys, which represent
these articulations. Inthe Pleurodira there is probably always an intergular scute
present. Sometimes the gulars meet in front of it.

The cervical vertebrz are, as in all turtles, 8 in number, but they differ greatly
from those of the Cryptodira and of the Trionychoidea. In contradistinction to the
neck of the latter turtles, that of the Pleurodira is constructed for free flexure in a
horizontal plane. This is effected by having the centra joined by ball-and-socket
joints and by having the zygapophyses of the two sides placed close together and
high above the centra. A description of these vertebra is given from the neck of
H ydromedusa te ctifera.

The neck is nearly a third longer than the dorsal series of vertebrae. ‘The first
cervical, unlike that of the other superfamilies, has all the elements consolidated
and is two-thirds as long as the longest. As regards the articular ends of the centra
we have the following: The first and the seventh are concavo-concave; the second,
third, and fourth are convexo-concave; the fifth and the eighth are convexo-convex;
the sixth is concavo-convex. All the cervicals possess well-developt transverse
processes, with broad bases. Along the lower side of the centrum of each runs
a sharp crest. The postzygapophyses of the first two vertebra are separated by

OSTEOLOGY. 13

only a slight notch; all the others have coalesct. The prezygapophyses are close
together, but have not coalesct. Those of the eighth are very small, thus greatly
different from those of the members of the other superfamilies.

In some of the other Pleurodira the intercentrum and the odontoid process of
the first cervical are distinct from the arches. In the Pelomedusidz only the second
cervical is convexo-convex; all the others concavo-convex.

In none of the Pleurodira is the neck withdrawn into the shell as it is in the other
turtles, but is bent sideways and brought under the projecting borders of the shell.
In harmony with this action, the anterior bones of the carapace and of the plastron
often project farther than in other turtles.

The skull of the Pleurodires offers many pec uliar structures. ‘That of H ydrome-
dusa may first be considered. This skull is long and very flat. There are distinct
nasal bones. The prefrontals do not send down | processes to the vomer. There is a
postorbital arch, but no zygomatic arch. At the rear there is a very slender palato-
squamosal arch. Seen om above the whole upper surface of the ptery goids and the
whole temporal fossee are exposed to view. There is no ridge projecting outward
from the parietal over what may be called the suprapterygoid fossa, as in other
turtles; nor does the prootic project forward over this fossa. The fossa just men-
tioned is bounded outwardly by the upturned outer border of the broad pterygoids.
The premaxille are small. The supraoccipital spine is extremely short.

Fig. 6 represents the skull seen from below. The
triturating surfaces of the upper jaw are very narrow.
The choanal openings are very large and are separated
by the splint-like vomer, which comes into contact with
the pterygoids. The latter bones separate widely the
small palatines. Behind the latter bones are the posterior
palatine foramina. The pterygoids are greatly developt
anteriorly and laterally. They are in contact on the mid-
line in front, but for more than half their length the
basisphenoid bone comes between them. ‘The pterygoids
are abbreviated behind, so that they permit the quadrates
to join the basisphenoid. This arrangement is character-
istic of the Pleurodires and distinguishes them from all
other turtles. The quadrate is notcht behind for the
passage of the stapes.

The lower jaw is slender and the coronoid processes
are low. The articular furnishes a ball for articulation
with the quadrate. There is present what Baur called

Fic. 6.—Hydromedusa. Skull

Pe ieee ean a presplenial, but which is here regarded as the true
aes :
nee _ splenial, a bone absent from most turtles.
boc, basioccipital; bsp, basisphenoid;
exoc, exoccipital; mx, maxilla; pa, The hyoid apparatus is greatly developt, but need not

parietal; pal, palatine; paoc, paroc- here be described.
Bee ae ae ee The scapula is a strong bone. The procoracoid
lation of quadrate with lower jaw; process makes less than a right angle with the body of
cei fs the bone. Between the two portions, in the angle, is a
sharp crest. The glenoid fossa is at the end of a long neck. The coracoid is
relatively short, much bent in a horizontal plane, and expanded at the free end.
The humerus resembles that of the emyds in most respects. The ulnar and
radial tuberosities are somewhat larger, the ulnar ascending slightly above the head,
the radial descending lower than in the emyds. ‘The ulna has no suggestion of an

14 FOSSIL TURTLES OF NORTH AMERICA.

olecranon. The tarsus and digits do not differ enough from those of emyds to
require further notice here.

The pelvis of Hydromedusa differs greatly from that of the emyds and triony-
chids. The ilia are much expanded and triangular at their upper ends, and have
become joined by a rough suture with the eighth costals. The lateral processes of
the pubes are stout and are sutured to rough surfaces on the xiphiplastra. The
anterior branch of the pubis is slender and joins its fellow at the midline. The
ischia are stout bones, sutured to the hinder border of the xiphiplastra. The lower
portion of each ischium expands into a great lateral process, which runs forward
and inward to join the one from the other side, the whole length of each process
being sutured to the xiphiplastron. ‘There is no bony union of the pubes and the
che along the median line. As shown by Baur (Jour. Morphology, tv, 1891, p.
351) there is, in many Pleurodires, a greatly lengthened prepubic cartilage. It is
to be compared with the prolongation forward seen in the pubes of species of
Baéna and Chisternon.

The hinder limb does not differ notably from that of the emyds.

Illustrations are here furnisht of the skull of Podocnemis expansa, another
Pleurodire, the structure of which in many respects strikingly differs from that of
Hydromedusa. From plate 4, fig. 1, it will be seen that the temporal region is
nearly as completely rooft over as is that of Lepidochelys (plate 1, fig. 1). There
are no nasal bones and the supraoccipital spine is long. In one feature of the
temporal roof this turtle is different from Leprdochelys. In the latter the postfrontal
bone extends backward nearly to the hinder border of the roof; in Podocnemis
the postfrontal bone is very small and its place in the roof is mostly occupied by the
quadratojugal, which rises over the squamosal, excluding the latter from contact
with the parietal (plate 4, figs. 1-5).

Fig. 2, plate 4, represents a palatal view of the same skull. The premaxillz are
of considerable size. The vomer is absent. The triturating surface of the maxilla
is broad and furnisht with ridges. The choanz are restricted. The palatines are
broad and meet throughout their length at the midline. The pterygoids, too, are
broad, little separated mesially by the basisphenoid, and the outer border of each is
turned upward into a scroll-like process. ‘The articular surface of the quadrate,
for the lower jaw, is seen to be concave.

Fig. 5, plate 4, shows the same skull viewed from the side.

The lower jaw (plate 4, figs. 3, 4) presents a ball-like articular surface for the
quadrate. In front of this are seen the angular, the prearticular, the splenial, and
the dentary, the latter consolidated with its fellow at the symphysis and furnisht
above with a broad and ridged triturating surface. On the outside of the hinder half
of the ramus is the supraangular.

THE DERMOCHELYID/E. THE LEATHERBACK TURTLES.

It is necessary now to describe in brief terms the skeleton of the leatherback
(Dermochelys cortacea), one of the most extraordinary of turtles. It attains a great
size and is the most thoroly aquatic turtle that is known (fig. 7). Figures of all
portions of the skeleton may be found on the plates illustrating a paper by Paul
Gervais on this turtle, publisht in the Nouvelles Archives du Muséum d’Histoire
Naturelle de Paris, volume vit, 1872.

The ribs of this turtle, instead of being consolidated with costal plates that
unite edge to edge to form a carapace, are wholly free from one another. The first
rib is wholly free from the second, the tenth from the ninth. The only thing that

OSTEOLOGY. 15

may be supposed to represent the costal plates is the irregular border of the some-
what expanded ribs. Of the other elements entering into the carapace of an emyd
or a pleurodirid, the leatherback possesses only the nuchal bone.

But the leatherback has a carapace peculiar to itself. ‘This is composed of a
layer of thin, polygonal bones which are buried in the thick skin of the animal. Of
these bones there are 7 rows of larger ones, that appear in the living animal as so
many sharp dorsal keels. One of these rows is along the midline; three run along
each side. In front, this layer of mosaic-like bones overlies the nuchal. Smaller
bones fill up the spaces between the rows.

On the inferior side of the turtle there are 5 rows of similar bones, but the spaces
between the rows are not so completely filled as on the upper side. Beneath the
skin which supports these rows of bones there is a ring of elongated bones which
represent the plastron of more normal turtles. ‘These represent the epiplastra,
the hyoplastra, the hypoplastra, and the xiphiplastra. The entoplastron is missing.
All these bones are slender and thin, and they surround a vast fontanel.

a -

Fic. 7.—Dermochelys cortacea. Greatly reduced.

The cervical vertebra differ in no important respect from those of Caretta, and
the neck is equally short. The dorsals are ten in number and immovably joined to
those in front and behind by rough articular ends. The neural arches are moved
forward, so that each articulates pont equally with its own centrum and that in
advance. They are somewhat expanded above, but do not come into contact with
plates from the ribs. In fact, these plates are extremely vestigial. There are two
sacral vertebrae, whose ribs articulate with the ilia; and there are about twenty
caudals.

The skull at first glance presents many resemblances to that of members of the
Cheloniidz. The temporal roof extends backward as far as the occipital condyle.
The postfrontal and the jugal are large, and the squamosal joins the parietal.
The supraoccipital spine is short. The prefrontals extend backward to beyond the
orbits. The external nares look forward and strongly upward. The maxillz are
not strongly developt; and they have hardly any triturating surfaces. The choanz
are placed far forward and open directly into the roof of the mouth. A splint-like
vomer separates them, and extends backward to the pterygoids. The palatines are
broad, and they reach forward nearly to the vomer, sometimes coming into contact
with it. Thus, they bound the choane outwardly. The pterygoids join on the mid-
line for a short distance only in front; otherwise, they are widely separated by the

16 FOSSIL TURTLES OF NORTH AMERICA.

basisphenoid and the basioccipital; they shut off the latter bones from contact
with the quadrate. The inner borders of the pterygoids lie upon the upper side of
the basisphenoid.

In one important respect the leatherback and its few fossil relatives differ from
all other turtles. This is in the fact that the parietal bone does not send downward,
in front of the exit of the trigeminal nerve, a plate to join the pterygoid.

The occipital condyle remains cartilaginous. ‘The pedicel of the quadrate is
slender and directed strongly forward. ‘The lower jaw is feebly developt and fitted
for soft food. The articular remains cartilaginous. ‘The angular and the supra-
angular are short, as seen from the outer side of the jaw, but are prolonged on the
inner side. The prearticular and the coronoid are not present.

The parts of the scapula are short and thick. The procoracoid process makes
an obtuse angle with the body of the bone. The coracoid bone is about twice as
long as the process mentioned, and the free end is somewhat expanded and flattened.

The humerus is a massive bone and much flattened. The general form is that
of the_humerus of Lepidochelys, but the radial tuberosity is brought down to a
point more than half-way from the head of the bone to the distal end. The end
for articulation with the ulna and the radius is very broad, and nearly semicircular
in outline. The ectepicondylar passage is a foramen wholly in the bone, about the
middle of its width.

The radius and the ulna are stout bones of about equal length and only about
half as long as the humerus. The carpus has 2 bones in the first row, a centrale,
5 bones in the second row, and a large pisiform. Sometimes the fourth and the
fifth distal carpals are co-ossified. ‘he digits have the normal number of pha-
langes; that is, 2 in the thumb and 3 in each of the others. The second, third and
fourth digits are greatly elongated, being twice the length of the humerus measured
from the head: None of the. digits Ree a claw. All are bound together in a com-
mon envelope of skin to form a powerful flipper.

The pelvis is in many respects different from that of the Cheloniide. The
form of the ilium and its position with respect to the pubis do not differ greatly
from those of the ilium of Caretta, but the ischia are broader fore and aft than in
Caretta. The pubes are connected along the midline for a much greater distance
than in the Cheloniidz. Posteriorly they approach the ischia, so as nearly to join
them, the interspace being filled by cartilage. The ischio-pubic foramina are
extremely small and nearly separated 1 in the reatne’ The lateral processes are
very large, extending outward and forward, so that at their extremities the pelvis
is twice as wide as it is across the narrowest part of the pubes. Each process
terminates in a large plate of cartilage. There is likewise a large spatulate prepubic
cartilage.

The hinder limb is reduced in size, as in the Cheloniidz, and offers differences
only in detail.

MODIFICATION IN TURTLES. 17

ON THE AMOUNT OF MODIFICATION UNDERGONE BY TURTLES
SINCE THEIR EARLIEST APPEARANCE.

On preceding pages a brief exposition has been presented of the principal
structures shown in the skeletons of turtles of various groups. It is now intended
to consider the differences of structure from another point of view, that of determin-
ing the amount of differentiation these animals have suffered since their earliest
appearance, especially as compared with the changes undergone by other orders of
reptiles. It is generally supposed that turtles have been unusually conservative in
their changes; that, as in their movements so in their development, they have
progrest slowly. We are to inquire to what extent this impression is true.

Let us first consider the shell, that part which is most often found preserved in
the rocks and the part which is regarded as most characteristic of turtles. ‘Lhe
theory accepted by the writer is that originally the upper side of the body was
protected by a rim of peripheral bones, a median row of neural bones, and eight
pairs of bony plates which overlay the ribs and had possibly in the earliest turtle
coalesct with them, probably joining one another by their contiguous edges; and
that in addition to the bones enumerated, subdermal in their position, there was a
more superficial layer of bones, dermal in position and forming seven longitudinal
zones, a median or vertebral zone, two costal, two supramarginal, and two marginal
zones. The plastron was formed of at least eleven subdermal bones, while super-
ficially there were found five zones of dermal bones, a median and two lateral on
each side of it. Starting with this outfit, the vast majority of turtles have wholly
or almost wholly divested themselves of the dermal layers and have acquired a solid
shell composed of the subdermal bones. On the other hand, the leatherback
turtle, Dermochelys, appears to have retained the dermal and to have almost wholly
surrendered the subdermal bones, for the costal plates now form only unimportant
fringes on the ribs; the peripherals and neurals are wholly gone; the nuchal
is reduced; and the plastral bones are only eight slender rods. As regards the
carapace, Dermochelys possesses little that is homologous with that of most other
turtles.

If we view the modifications undergone by the shell within the group known as
Thecophora we find that they are extensive. We can hardly doubt that the primi-
tive turtles possest a pair of mesoplastral bones; and yet we know that all turtles
have discarded these, except a few of the Pleurodira. Within the latter super-
family the shell has not suffered remarkable modifications. Nevertheless, most
of the genera have no mesoplastra. In some the plastron is connected with the
carapace ligamentously, while in others strong axillary and inguinal buttresses rise
from the plastron and articulate with the inferior surface of some of the costals. In
all, the hindermost costals have contracted a sutural union with the ilia. In a
considerable number of genera the neurals have become wholly supprest. In
Pelusios (Sternotharus) there is a hinge behind the hyoplastra.

In the superfamily Trionychoidea the shell has undergone extensive reduction.
No traces are known of the original dermal layer of bones The neurals and the
costal plates are retained; but mehe latter show retardation in their dev elopment,
attaining the distal ends of the ribs not at all or only at a late date in life. The
peripherals are wholly missing, except perhaps in the genus Trionyx (Emyda Gray).
In the plastron we never find mesoplastra and all the bones are more or less reduced.
In the great majority of cases there are fontanels on the midline and at the bridges.
The form and relations of the entoplastron and the epiplastra are very different
from those of other turtles, but homologies are easily traced.

2

18 FOSSIL TURTLES OF NORTH AMERICA.

It is in the extensive group of Cry ptodira that we meet with the greatest number
of what may be regarded as the minor modifications of the shell. If we except
T oxochelys, no moan Cryptodire shows more than vestiges of the ancient layer
of dermal bones. In some, as Protostega and Archelon, OF the Upper Cretaceous,
the costal plates are nearly as much reduced as in Dermochelys. In these and a
number of other genera of Cretaceous turtles the peripherals are slender, but they
persist. Probably the neurals are never wholly absent. The elements of the
plastron degenerate i in some cases; but, with the exception of the entoplastron of a
few genera, “All persist.

It is in this group that we discover the greatest variety in the forms of the shell,
ranging in convexity from much deprest to highly vaulted and bombous, and from
relate ely long and narrow to a breadth greater than the length. There may be
one or more carinz on the carapace and its free borders may be smooth or variously
notcht or rolled.

In some genera of Cryptodira, as the snappers and the sea-turtles, there are
extensive Foeanels between the distal ends of the ribs and others at the sides and
the middle of the plastron. In most Cryptodira the bones are solidly articulated,
abrogating all fontanels. In the snappers and the sea-turtles again, the plastron
is only ligamentously joined to the carapace. In other genera, as Batagur , Hardella,
and Echmatem ys, the plastron sends up powerful axillary and inguinal buttresses to
the inside of the carapace. Between these extremes there are all gradations.

Among the Cryptodira there is a great variety of hinges between portions of the
shell. ine G yclemys there is a hinge between the hyoplastron and hypoplastron,
and both these bones are sutured to peripherals. In Terrapene there is a similar
hinge, with the bones only ligamentously joined to the carapace. In the extinct
genus Ptychogaster there is a sliding j joint between the hy poplastron and the contig-
uous peripherals. In Kinosternon there is a hinge between the epiplastra and the
hy oplastra, and another between the hypoplastra and the xiphiplastra. In Kinixys
there is a hinge in the carapace between the fourth and the fifth costal plates.

Attention may be called to the modifications of the neurals and the costal plates
in Testudo. The neurals are alternately large and octagonal and small and quadrate.
The costals are truncated wedges, placed so that broad and narrow ends alternate
both next the neurals and the peripherals.

There are numerous interesting modifications in the number, form, and disposi-
tion of the horny scutes of the shell among the turtles. “There are supposed to have
been originally 12 rows, or zones, of cece scutes, corresponding to the 12 rows of
dermal hones of Derren: and the ancestral turtle. A scute coincided with each
bone. In each row some scutes grew at the expense of the others and persisted even
after the disappearance of its supporting bone. Whole rows of the scutes dis-
appeared, as the supramarginals and the median plastral row of most turtles. The
supramarginals are represented in Macrochelys by a few scutes over the bridges.
The anterior and posterior ends of the supramarginal series are found in the Triassic
Proganochelys. Many genera furnish the inframarginals, as nearly all the Derma-
temydidz. In the Emydide all have vanisht except one in the axillary notch and
another in the inguinal. In the Baénidz, the Dermatemydide, and the Pleurodira
we find the muddle plastral row represented by the intergulars. Archeochelys
Lydekker and Polythorax Cope present more posterior scutes i this row. Between
a young Dermochelys with its 12 rows of epidermal scutes, with many in each row,
and Terrape ne, with only 7 rows, there are many and interesting stages.

But the Trionychidze carry the reduction of the scutes to the extreme, for none of
the whole superfamily shows any traces of these whatever. In various species of the

MODIFICATION IN TURTLES. fe)

other groups the boundaries of the scutes are not visible on the shells; but in most
of these cases the scutes were probably very thin and their edges did not impress
the bone. In the living Carettochelys and the extinct Penienienie yx, both Crypto-
dires, there are no scutes.

The principal characters which belong to turtles in general will be given on a
succeeding page. Besides these common characters, others that have been lost or
modified were possest by the more primitive members of the order. Of these may
be mentioned the presence of nasals, of lachrymals, and of an extensive roof over the
temporal region. ‘The presence of this roof in the skulls of the older turtles is so
general, perhaps rather so universal, that its primitive nature can hardly be doubted.
Its frequent presence in the skulls of the lower forms of living turtles and its general
absence in the case of the higher forms confirm this conclusion. ‘This roof must have
been inherited from the Cotylosaurian ancestors of the order. Otherwise, we must
suppose that it was developt during the history of the chelonians and again lost by
most of them. It appears obvious that the roof has been reduced in proportion to the
elongation of the neck and the ability to withdraw the head beneath the shell. In
Dermochelys and the Cheloniide the roof extends backward as far as the occipital
condyle; and all these turtles have short necks and can furnish beneath the shell
little protection to the head. In the snappers the roof is moderately developt; in
most of the Emydidz and all the Trionychoidea the roof is reduced to a narrow
postorbital bar and to a zygomatic bar. In some species of Terrapene and in some
other genera the zygomatic bar is missing. While in some Pleurodira, as Podocnemis,
the roof is wide, 1 in others nothing is left but the postorbital bar. Several genera
possess a parieto-squamosal arch (Rhinemys, Hydrasprs, Hydromedusa). Dr.
George Baur showed the various ways in which these results have been attained.
In the Cryptodira the roof has been eaten away from behind forward and in front
of the tympanic cavity, severing first the union of the parietal and the squamosal,
then that of the postfrontal and the squamosal, and finally in rare cases that of the
jugal and the quadratojugal. In the Pleurodira the reduction has followed the
reverse course, beginning in front of the tympanic cavity and moving upward and
backward. In several genera of Pleurodira there has been left only a very narrow
parieto-squamosal bar; in others, not even this. In all cases the remov al of the
bone has begun at one border or the other of the bone and never by the formation of
fontanels in the roof.

In no other order of reptiles do we find such enormous variation in the character
of the temporal roof. Superfamilies and families of turtles present modifications
that would characterize orders of other reptiles.

The palatal region offers variations in structure that are of wide range. Primi-
tively the choane opened i in the front of the mouth one on each side of the narrow and
shallow vomer. A broadening of the triturating surfaces of the jaws required that
the choanze be pusht backward. This was accomplisht by the development of
a median descending plate of the vomer, which spread laterally and joined palatal
plates from the maxilla, the palatines, and sometimes even from the pterygoids.
Thus a floor was formed beneath the nasal channels, carrying these backward
sometimes more than half-way to the occipital condyle. The process is similar to
what occurred in the order of Crocodilia; only, in the most primitive known forms
of the latter the choanz are placed immediately in front of the pterygoids, while in
the most advanct forms the choanz are in the rear of these bones. These differences
were regarded by Huxley as sufficient to justify the recognition of two groups of
crocodiles, the Mesosuchia and the Eusuchia. Variations oi greater extent among the
turtles characterize families only or even genera.

20 FOSSIL TURTLES OF NORTH AMERICA.

The jaws have suffered extensive modifications. In the less differentiated
turtles the cutting-edges of the jaws are low and the triturating surfaces narrow.
The cutting-edges may become deep, without increase of the width of the triturating
surfaces and wice versa. For an illustration of great width of the grinding surfaces
the reader is referred to the species Rhetechelys platyops (Cope).

The lower jaw becomes modified to correspond with the upper jaw. The rami
of that of Toxochelys latiremts are narrow and slender; while those of Erquilinnesia
are broad, flat, and fitted for crushing hard objects.

The vomer, which is always developt in the Cryptodira, the Trionychoidea and
some of the Pleurodira, is wholly missing in some forms of the latter superfamily.

There is great variation in the pterygoids. The primitive condition appears to
be essentially that now found in the Cryptodires in which these bones are of
moderate width and extend backward so as to exclude the quadrates from contact
with the basicranial bones. This condition exists also in the Amphichelydia and
the Trionychoidea. In the Pleurodira the pterygoids have become shortened poste-
riorly, so as to let the basicranial bones join the quadrates. “They have also become
expanded, and the outer edge is rolled up in a scroll-like manner.

The necks of turtles furnish us with many interesting features. There is
no doubt that in the early turtles the neck was short, perhaps less than half as long
as the dorsal series of vertebra. Doubtless the lengthening has been brought
about to facilitate the prehension of food, but it has had other consequences. In
some species of each of the superfamilies of Thecophora the neck 1s considerably
longer than the dorsal series, but it has retained its primitive shortness in Dermo-
chelys and the other sea-turtles. The elongation of the neck is never due to any
increase in the number of vertebra, but to the lengthening of the individual vertebra.

The most important modifications of the cervical vertebra are to be found, not in
their mere elongation, but in the structure of their parts. Originally, as we learn
from Glyptops plicatulus, the vertebral centra were all biconcave. In Baéna and
Chisternon we find the beginnings of differentiation in the articular ends of the
centra. The highest stage of differentiation is perhaps to be found in species of
Testudo. In Testudo radiata, of Madagascar, the second cervical is convexo-
concave; the third and the eighth convexo-convex; the fourth, fifth, and sixth,
concavo-convex; the seventh, concavo-concave. ‘The joint between the sixth and
seventh and that between the seventh and the eighth are elongated from side to side
and divided into right and left portions, forming true ginglymoid articulations.
Variations of this arrangement are found even within the genus Testudo. Modifi-
cations and less differentiated stages are to be found in other families of Cryptodira.

The necks of the Trionychoidea are usually greatly elongated and the vertebre
are essentially as in the Cryptodira. The Pleurodira do not possess ginglymoid
joints, but in at least one genus there are saddle-shaped vertebral articulations, as
in birds.

In the development of the mechanisms permitting flexion of the neck two distinct
paths were followed, the Athece, the Cryptodira, and the Trionychoidea taking the
one, the Pleurodira the other. The goal reacht in each case is very different from
that attained in the other. In the first case, the neck is bent in a perpendicular
plane; in the case of the Pleurodira, in a horizontal plane. As the neck of members
of the Cryptodira and Trionychoidea lengthened, the head began to be withdrawn
within the shell for protection. In the case of the Pleurodires the neck is bent
laterally, and it and the head are protected by the projecting borders of the shell.
If the neck is so long that it would carry the head beyond the axilla it is bent first
in one direction, then in the other.

MODIFICATION IN TURTLES. 21

To permit these different modes of flexion the mechanical arrangements must
be different. In the Cryptodires and the trionychids there are ginglymoid joints
at the base of the neck, facilitating bending in a perpendicular plane. The neural
arches are low, with the zygapophyses wide apart, favoring motion in the vertical
plane, restricting it in the horizontal. In the Pleurodires the arches are high, the
zygapophyses close together, often confluent, and at least one end of most of the
centra semiglobular, arrangements aiding motion in a horizontal plane.

It is doubtful whether there is another group of vertebrates that possesses so
many modifications of the cervical vertebra as are found in the turtles.

‘There has occurred a considerable amount of modification in the pelvis of these
reptiles. As shown by Glyptops, of the Jurassic, and Baéna and Chisternon, of the
Bridger, the pelvis was not originally suturally joined to the shell. In both the
Cryptodires and the trionychids the pelvis has retained its original freedom. In
the Pleurodires the ilia effected, before the close of the Cretaceous, strong sutural
connections with the hindermost costal plates; while the ischia and the pubes
became closely sutured with the xiphiplastra.

In the Amphichelydia the ischia and the pubes are joined along the midline by
a bar of bone, thus defining right and left ischio-pubic foramina. In the Baénide,
so far as known, and possibly in Glyptops, the prepubic process was strongly
ossifed. In the Emydidz and the Testudinidz the ischio-pubic bar is ossified; but
in the Cheloniidz and the Trionychoidea this region is wholly cartilaginous. ‘That
the primitive condition of the ischio-pubic bar and of the prepubic process in the
Amphibia and the early Reptilia was cartilaginous we can not doubt. That these
should be ossified in the Amphichelydia is remarkable. It suggests that the carti-
laginous condition in so many living tortoises may be due to degeneration.

The limbs of most swamp-loving turtles present primitive conditions of the
reptilian limb, both with respect to their composition and their disposition. The
segments of the limbs are mostly flext in one plane, and this plane stands more or
less at right angles with the axis of the body. The apex of the angle at the elbow
is directed forward, rather than backward as in the mammals, and the ulna and the
radius do not cross. There have occurred few unions of bones and these are con-
fined to the carpus and the tarsus. No bones have suffered important reductions
or modifications. In the limbs of swamp-inhabiting turtles there have been few
changes since Jurassic times; and, since the Amphichelydia, the Cryptodira, and
the Pleurodira possess similar limbs, it is evident that the primitive turtles possest
limbs not greatly different.

From this simple type of limb there has been divergence in two directions; one
to adapt the animal for life on the land, the other for habitual life in the water.
The highest expression of the former adaptation is perhaps to be found in the limbs
of species of Testudo. In these the principal modification in the proximal bones
of the limbs is the drawing downward and toward each other of the tuberosities of
the humerus. Most important is the shortening suffered by the bones of the digits
and the reduction of the number of phalanges in each to no more than two. The
fifth hinder digit may become vestigial. The result of these changes is the pro-
duction of a short foot resembling that of an elephant and adapted for travel over
rough and hard ground.

To fit the animal for habitual life in the water the anterior limb tends to be
converted into a flipper. First of all, the fingers become elongated to support a
broad web. Usually the number of phalanges remains unaffected. In the Trio-
nychidz some of the digits are much elongated and the phalanges are more numerous
than the normal, and two of the claws have disappeared. In the sea-turtles,

22 FOSSIL TURTLES OF NORTH AMERICA.

never coming on land except to deposit their eggs, the fore limbs have become
transformed into definite flippers with the fingers elongated and all bound together
in a common mass of skin and muscles. Only one or two claws remain. ‘The
phalanges and carpals are considerably flattened, as is also the humerus. The
latter also becomes straighter and the insertions of the deltoid muscle descend on
the shaft. While these changes progrest the hinder limb became relatively smaller
and fitted for steering the animal. ‘The extreme of these modifications is to be
seen in the limbs of the leatherback, Dermochelys. Between the short club-lke
foot of Testudo and the long and powerful flipper of Chelonia and Dermochelys there
is a vast interval.

Amid all the changes that have occurred in the turtles certain fundamental
structures have remained unaffected. The jaws have always retained their horny
covering. The quadrate has remained fixt. The cervical vertebrae have kept
unchanged their number, 8, and the dorsals their original number, 10. All four
of the limbs have persisted and all the segments of each.

A consideration of the changes which turtles have undergone and a comparison
of these with the modifications suffered by other groups of reptiles lead to the
conclusion that no other order of these animals, except the Squamata, can display
such a variety of structures. The Squamata, embracing the mosasaurs, the lizards,
the chameleons, and snakes, have undoubtedly, in adaptation to different modes
of life, diverged in more directions and gone farther than have the turtles. The skull
has become modified in more ways; the vertebra, at least as regards the number in
the column, have varied more; the limbs have undergone more varied adaptations
for walking, for climbing, for grasping, for swimming, for leaping; and in the whole
group of snakes and in many lizards the limbs have wholly disappeared. ‘To these
denizens of the earth, swarming since probably the Triassic, the turtles must yield in
variety of form and structure and habits, but probably to no other order of reptiles.

PRIMARY AND SECONDARY CHARACTERS. 23

ON THE PRIMARY AND THE SECONDARY CHARACTERS OF TURTLES.

It may be interesting and productive of some useful result to endeavor to separate
the osteological characters that belonged to the most primitive turtles from those
that may be called the secondary characters, those that have been acquired in later
times through the exaggerated development or reduction or the suppression of cer-
tain parts of the skeleton or their modification of form and connections, in order to
adapt them to new uses. We will, as heretofore, consider first the shell of the turtles.

As already stated, the writer holds the view that the earliest turtles possest
practically two kinds of shell, one purely dermal, consisting of probably a mosaic
of small bones arranged in at least 12 longitudinal zones. Each zone probably
consisted of a row of larger bones, bordered on each side by smaller ones. It is not
necessary to suppose that the spaces between the zones were wholly occupied by
these smaller bones. Each of these bones was covered by a horny scute. The
nearest approach to such a dermal shell is in our days seen in Dermochelys, as has
already been stated.

Beneath the skin there seems to have existed a carapace more or less complete
which consisted of a nuchal, a median row of neurals, 8 pairs of costals, a pygal,
probably one or more suprapygals, and about 11 peripherals on each side. To
what extent the neurals and the costal plates had become anchylosed to the neural
spines and the ribs respectively it is now impossible to determine. Nor can we say
to what extent the various elements of this carapace had become connected with one
another. ‘The existence of the dermal carapace would appear to indicate that the
subdermal box was not yet closed.*

There was a subdermal plastron that was composed of at least 11 bones.
Portis has described Polysternon, which had an additional pair of bones between the
hypoplastra and_ the xiphiplastra, making 13 all together. Between these various
bones there may have existed more or less extensive fontanels.

According to the author’s views, as time went on the external, mosaic-like shell
disappeared in most turtles, while a more efficient armor was developt out of the
subdermal elements. In the ancestors of Dermochelys, however, the dermal armor
was retained, while the more deeply seated one disappeared, with the exception of
the nuchal bone.

It is proper to state that all authors do not hold that Dermochelys has descended
to us in a direct line distinct from other sea-turtles, but has been derived from them
at a more recent date. On this subject the reader must consult the papers of Baur,
Boulenger, Case, Dollo, E. Fraas, Hay, Van Bemmelen, and Wieland.

Most Thecophore turtles have lost the bones of the outer dermal shell. There
are yet traces of it perhaps in the dorsal and ventral keels of various turtles, in the
tubercles that diversify these keels, and especially in the rows of horny scutes that
had their origin from these dermal bones. In one turtle, however, Toxochelys,
of the Upper Cretaceous, there are yet remains of the dermal armor in the shape of
a row of bones along the dorsal median keel. For a description and illustrations of
these the reader must consult later pages of this work.

In a paper written in 1898 (Amer. Naturalist, xxx11, p. 929) the writer denomi-
nated such bones as the nuchal, the peripherals, and suprapygals as ‘‘fascia bones.”
This was done simply to distinguish them from more superficial bones, called
dermal. Ina recent paper Mr. H. H. Newman (Biol. Bull. x, p. 74) has referred
to this paper and has insisted that the nuchal is a dermal bone. Such it doubtless

*For Dr. George Baur’s latest views regarding the primitive condition of the carapace and plastron
of the turtles see Anatomischer Anzeiger, XII, 1906, p. 567.

24 FOSSIL TURTLES OF NORTH AMERICA.

originally was, but it is now overlain by the dermal mosaic. Mr. Newman holds also
that the peripherals and the suprapygals are dermal bones, not what the writer called
fascia bones or subdermal bones. If the reader will consult the succeeding pages that
deal with Toxochelys he will see that one of the dermal nodules overlies the second
suprapygal. ‘The latter is therefore not equivalent to the row of nodules in front
of it and to those on the tail of the snapping-turtle, but is a bone of a deeper layer.

We may, therefore, for the present regard the characters of the most primitive
turtles as having been the following: There was a superficial armor composed of
dermal bones arranged in at least 7 zones above and at least 5 zones below, with
many bones in each zone, and each bone covered by a horny scute. Beneath this
was a subdermal armor. On the upper side of the body, this consisted of the nuchal,
a row of neurals, 8 pairs of costal plates, suprapygals, and peripherals; below, of
the entoplastron and at least 5 pairs of subdermal bones. ‘There were 18 presacral
vertebra, of which 10 belonged to the trunk and were without transverse processes
and more or less immovyably joined to each other and to the ribs and neural plates.
The neck was short and consisted of 8 biconcave vertebra, which possest transverse
processes and low neural spines. ‘There may possibly have been present some
cervical ribs. ‘There were 2 sacrals. “The tail consisted of biconcave vertebre,
each provided with free ribs, with chevron bones below, and perhaps with one or
more rows of bony nodules above.

The skull had a complete temporal roof, but the temporal fossa was probably
not widely open behind. There were nasals, lacrimals, and prefrontals, all
distinct from one another. “There was no parietal foramen. A vomer was present
but no prevomers. The choanz opened far forward in the roof of the mouth. The
quadrate was fixt, somewhat excavated to form a tympanic cavity and notcht
behind for the stapes. Probably the palate was closed by the union of the pterygoids
with each other and with the basisphenoid. The parietals may or may not have
sent down each a plate to the pterygoid, in front of the exit of the trigeminal nerve.
The paroccipitals were free from the exoccipitals. “UVhe jaws were without teeth and
were covered by a sheath of horn. Each ramus of the lower jaw was doubtless com-
posed of 7 elements, and the dentaries were probably not co-ossified at symphysis. ‘I he
outer surface of the bones of the skull was covered by horny scutes. ‘I he shoulder-
girdle consisted of a pair of coracoids, a pair of scapula, and a pair of procoracoids;
the latter probably co-ossifying somewhat late in life with the scapula. Limbs, fore
and hinder, probably not greatly different from those of living Chelydridz, but more
crudely modeled. “Lhe phalangeal formula was 2, 3, 3, 3, 3 in all the feet.

If the views exprest above regarding the original composition of the armor of
turtles is correct, the possession of a carapace consisting exclusively of a mosaic
of dermal plates, as in Dermochelys, is a secondary character; as 1s likewise the
possession of a shell constituted only of the deeper elements, as in the great majority
of turtles. Other secondary characters are the absence of entoplastron (Dermo-
chelys, Kinosternon), the absence of peripherals (Trionychotdea), and the absence of
mesoplastra, as in most living turtles. Such too is the lack of nasals and lacri-
mals in the great majority of turtles. ‘The adaptation of the limbs for habitual
swimming is, of course, a secondary modification of these organs.

In this category, too, belong those modifications of the cervical vertebra by
virtue of which the neck has become so greatly elongated in most forms and made
most freely flexible in a horizontal plane in the Pleurodira and in a perpendicular
plane in all the others. Most extraordinary of all the secondary characters is that
complex of modifications which permits the head and neck to be retracted between
the scapulz, the loop in the neck sometimes reaching backward quite to the pelvis.

CLASSIFICATION. a5
THE CLASSIFICATION OF THE TURTLES.

It is not the purpose of the writer to give here an account of the various schemes
of classification that have been proposed by writers on the turtles. For such an
account the reader may consult the third part of the sixth, volume of Bronn’s
Klassen und Ordnungen des Thierreichs, beginning with page 347. The following
is the arrangement of suborders, superfamilies, and families accepted by the writer.

All of these families, except those in italics, have fossil representatives.

Orver Testudines.
SuporpDeER I. Athecz.
Famity. Dermochelyide.
SusorpeR II. Thecophora.
SurERFAMILY 1. Amphichelydia.
Famutigs. Pleurosternida, Baénide, Plesiochelyida ?
SUPERFAMILY 2. Pleurodira.
Famities. Bothremyide, Pelomeduside, Chelyide, Miolanide.
SUPERFAMILY 3. Cryptodira.
Famities. ‘Thalassemydide, ‘Voxochelyide, Desmatochelyide, Protostegida, Cheloniide,
Tretosternida, Chelydrida, Dermatemydide, Platysternide, Kinosternide
Carettochelyd, Emydide, ‘Testudinide.
SupeRFAMILY 4. Trionychoidea.
Famiuies. Plastomenide, Trionychide.

The arrangement and names of the suborders and superfamilies above given
are the same as those used by Mr. George A. Boulenger in his Catalogue of the
Chelonia of the British Museum, 1889. Mr. Richard Lydekker employs practically
the same groups in his Catalogue of the Fossil Reptilia of the British Museum,
part 11, 1889; but to some of his groups are given different names. Dr. Louis
Dollo, of Brussels, also divides the turtles into the two suborders Athece and
Thecophora. Altho this eminent writer believes that Dermochelys, the only living
representative of the Atheca, was derived from the Cheloniidz, he separates it as
the representative of a distinct suborder on account of its extreme modifications of
structure. It was Cope who first proposed to make this turtle the type of a distinct
suborder.

In his Bibliography and Catalogue of the Fossil Vertebrata of North America,
1902, the present writer assigned to the ‘Trionychoidea, under the name Trionychia,
the rank of a suborder. A further consideration of the subject has convinct him
that these turtles should rank lower than a suborder; not higher than a super-
family. Indeed, they appear to have brancht off from the earliest Cryptodira;
but their lineage is so ancient, and they have undergone so many modifications of
structure, that they are of equal rank with the Cryptodira. The skull is more like
that of the Cryptodires than that of the Pleurodires, but has developt peculiarities
of its own. Like the Cryptodires, the temporal roof has never been eaten away from
below, and always a zygomatic arch remains. The neck is wholly cryptodiran in
its modifications and is retracted within the shell in the same way. This isa feature
unique among animals, and it seems improbable that it could be hit upon independ-
ently by two distinct groups of turtles. The pelvis in its parts and its relationships
to the shell is entirely cryptodiran.

Ernst Haeckel, in his Systematische Phylogenie der Wirbelthiere, 1895, page 320,
has taken the position that the Trionychoidea had probably arisen already in the
Triassic and that they are to be lookt upon as the group from which all the The-
cophora have been derived. That the group was establisht even in the Trias is
possible; that it gave origin to the other groups of Thecophora seems quite impos-

26 FOSSIL TURTLES OF NORTH AMERICA.

sible. None of the superfamily has nasals, lacrimals, or temporal roofing. Their
derivatives must have acquired these bones. ‘The neck is most completely of all
turtles adapted for retracting the head within the shell. ‘To give origin to the neck
of the Pleurodires this neck must have lost its peculiar mechanisms and acquired
those of the side-neckt or snake-neckt turtles. To have produced the neck found
in the Amphichelydia, that of the Trionychoidea must have shortened greatly
and have changed its biconvex and its concavo-convex vertebra into biconcave
ones. The Amphichelydia, the Cryptodira, and the Pleurodira must have developt
peripheral bones, instead of inheriting them from their ancestors. “The Amphiche-
lydia and many Pleurodires did not inherit their mesoplastral bones, but acquired
them independently. The limbs of those Thecophora that are fitted for walking
must, according to the scheme of derivation proposed by Haeckel, have been evolved
from feet fitted for swimming. ‘Turtles endowed with a covering of horny scutes
came from a race which are wholly devoid of these coverings. All these procedures
are the exact reverse of what is generally believed to be the course followed by animals
in their evolution. If it be claimed that the Trionychoidea of that early time possest
nasals, lachrymals, and a temporal roof, that the neck was yet short and composed
of biccelous vertebra, that they had peripheral bones and mesoplastra, then they
were not [rionychoidea at all, but Amphichelydia or something very close to them.

It is a dithcult matter to estimate properly the relative rank of the three super-
families of the [hecophora—the Pleurodira, the Cryptodira, and the Trionychoidea.
As to the Amphichelydia, there can be no doubt that this group ranks below all
the others and that from it have been derived all the others. It appears that the
Pleurodira are usually regarded as the most specialized turtles. There is no doubt
that the skull and the pelvis have departed farther from those of the Amphichelydia
than have those of either the Cry ptodira or the Trionychoidea. The most im-
portant modification in the skull is the posterior shortening of the pterygoids,
Ww hereby the basisphenoid is permitted to join the quadrate. Likewise the outer
anterior border of the pterygoids has become rolled up in a peculiar manner. On
the other hand, the skull of a number of genera has retained the nasals and the
posterior notch in the quadrate, both primitive features. It seems to the writer that
the neck is less specialized than that of the Cryptodira and Trionychoidea. The
shell has undergone far less specialization than that of the other groups mentioned,
many of the genera retaining the mesoplastra, elements unknown in the others.
On the whole, the writer is inclined to place the Pleurodira below both the Crypto-
dira and the Trionychoidea.

As regards the Trionychoidea, it is believed that the skull has departed further
from the amphichely dian pattern than has that of most of the Cryptodira. ‘This is
seen in the universal reduction of the temporal roof to narrow postorbital and
zygomatic arches, the backward prolongation of the squamosal processes, and the
closure of the stapedial notch in the quadrate. Altho the articular ends of the cer-
vicals present, so far as is known, less variety of form than in the Cryptodira, the
neck is, as has been said by Boulenger, more perfectly adapted for complete and
rapid retraction than in any other dhelomione The carapace has become greatly
specialized through degeneration of the peripherals and of the horny scutes. The
limbs have Become moderately specialized for swimming. The Trionychoidea can
hardly rank below the Cry ptodira; it is convenient to let them, in a scheme of
classification, f follow the group just mentioned.

In fig. 8 an attempt has been made to indicate the connections between the
different families of turtles. ‘his chart differs in some respects from the one pub-
lisht by the present writer in the Bulletin of the American Museum of Natural

CLASSIFICATION.

—— ee

aDP MHD

<

apprtphjaVg

opp iphuawusad

Pleisto-

appih}ayI0}IMND

DPM )AYIOULLAT

appryohUuorvl

IDPLULPNISIL,

appiphugy

Pliocene
Miocene

DpPit Uo2OUO

IDPISNPIULOPAT

cene

app ihjayoojnusagq —>

9091607807 0.bq —> |—_—$_———— - - - +

apprijaya0x0 [, —>

DD PLUoUWOISD]

appiphuawyjog

IDPLULIISOJIAT,

IDPLUIVT

ss

ceous

avprphwassP) OY L

Ds nap

IDPLULISOLNI) | —> ——_ |

anpiijayI0180)q—> —__—__———— - ----

ceous

oye

4

Jurassic

todira

JryP

Primitive iC

aAlmphichelydia

Triassic

e Thecophora

Primitir

Permian

1es

genetic chart showing supposed relationships of the famil
and higher groups of turtles.

Fic. 8.—Phylo

28 FOSSIL TURTLES OF NORTH AMERICA.

History, volume xx1, 1905, page 167. Since the publication of that paper discovery
of new materials has shown that Anosteira belongs among the Dermatemydide.
The family Bothremydide, recognized in the present work, is represented in the
chart as springing from ancestral Pelomeduside during the Lower Cretaceous.
It is wholly possible that Taphrosphys itself belongs to the Pelomedusidz, instead
of the Bothremydide. It has been concluded that the stock that gave origin to the
Emydidz, and the Vestudinidz ought to be brought into closer connection with the
Dermatemydide. The Carettochelyida also are represented as arising from the
Dermatemydide. It is not improbable that they should have been regarded as
direct descendants of the Tretosternide.

The geological distribution of the families will be considered on a coming page.

THE DERIVATION OF THE ORDER OF TURTLES.

At the present day the most interesting and the most difficult questions that
confront the student of any group of animals or plants are: From what lower group
was this derived? and: What are its relationships to kindred groups? We must
here at least make the inquiry: From what lower order of reptiles have the turtles
been derived ? and the further inquiry: What are the relationships of this order to
other orders of reptiles? The reply must be: We can not yet give definite answers
to these questions.

Nevertheless, some progress appears to have been made toward framing answers
to these inquiries. It is quite generally agreed that the Cotylosauria or closely
related forms, known from remains occurring in Permian deposits, are the lowest,
the least differentiated, of all reptiles hitherto discovered, having themselves been
derived directly from the Stegocephalia. On this point see Baur (Anat. Anzeiger,
x11, 1896), Cope (Proc. Amer. Philos. Soc., xxx, 1892, p. 279), Osborn (Mem.
Amer. Mus. Nat. Hist., vitt, 1903, p. 450), Woodward (Vert. Paleontology, 1898,
p. 144), Broile (Paleontographica, L1, 1904, p. 106). From the Cotylosauria, Baur
derived the turtles thru rhynchocephalian ancestors, animals not distantly related
to Sphenodon. Cope concluded (Proc. Amer. Philos. Soc., xxxv, 1896, p. 124)
that the cotylosaurian Otoccelida, which he afterward removed to the order Chely-
dosauria (Syllabus of Lectures, 1898, pp. 54, 61), were the source of the turtles.
Osborn, as cited (p. 465), brings the line of descent of the turtles from the Coty-
losauria through the Anomodontia. Woodward, as cited (p. 170), calls attention to
the apparent relationships between the turtles and the Anomodontia, in which group
he includes the Cotylosauria and the Chelydosauria. Case has publisht a paper
(Jour. Geology, x11, 1905, p. 126) in which he describes a species of Diadectes.
In this communication he shows that the family of Diadectidz is to be transferred
to the Chelydosauria; and he demonstrates that there are many resemblances
between the skull of his specimens and that of turtles. He holds that we have in the
Diadectidze “forms very closely related to the ancestral stem of the turtles, which tell us
much regarding the development of the Testudinata directly from the Cotylosauria.”’

The Cotylosauria and the closely related Chelydosauria indicate their eligibility
to stand as the ancestors of the turtles by the possession of a complete roof over the
temporal fossa, by the character, rare among reptiles, of having 18* presacral
vertebra, by the existence of digits having the phalangeal formula, 2, 3, 3, 3, 3-
Case has shown that the claims of the Diadectidz for the honor of the ancestry of
the turtles are superior to those of the Cotylosauria, as limited by him, inasmuch as

*Broili states that in Labidosaurus hamatus there are at least 24 presacral vertebra.

DERIVATION OF ORDER. 29

in Diadectes the temporal roof is notcht where applied to the quadrate and the latter
is excavated to form a tympanic cavity; instead of a pair of prevomers, there is a
single vomer; and there is a sort of carapace composed of bony plates ov erlying
ae pairs of the ribs.

It seems evident that we are getting close to the base of the phylogenetic tree of
the chelonians; but, likewise, et we have not yet reacht it. Taking into con-
sideration the fact that no turtle possesses a temporal fenestra, that when the
temporal roof is deficient either the zygomatic arch or the parietal arch or both are
missing, it seems impossible to derive ake turtles from any group of reptiles in which
even the beginning of such fenestra has been made. If this view is correct, there are
excluded at once from the chelonian ancestry all those reptiles belonging to Professor
Osborn’s Diapsida and all the Anomodontia, limited so as not to include the
Cotylosauria. The Diadectide, too, would be excluded, if they really possest
temporal fenestrae. If the presence of a pair of prevomers, instead of a vomer, has
the importance attributed to it by some recent authors, the Cotylosauria, as limited
by Case, would have to forego their claims. Of known reptiles we appear to be
limited to the Diadectidz and the Otoccelide, in our search for the ancestors
of the chelonians.

It is improbable that any of the reptiles of the Permian of Texas or equivalent
deposits were the ancestors of the turtles. When we consider that already in the
Upper Trias the turtle Proganochel ys possest a typical shell, we must conclude that
the earliest of the race must have been in existence as early as the Permian itself.
It is, of course, possible, indeed quite probable, that some earlier, less differentiated
form of one or the other of the two families just mentioned gave origin to the most
primitive turtles.

It is a serious objection to any of the Cotylosauria, using the name in the wider
sense, that have been mentioned as possible ancestors of the fartlest that they appear
to Rave possest no ventral armor. Almost certainly the turtles inherited this portion
of the shell, in some form, from the Stegocephalia. The Diadectes described by
Case presented no traces of a plastron, or of abdominal ribs. There are various
other reasons why this reptile can not pose as the founder of the chelonian line.
Among these are ‘the elevated spines of the vertebra, the great amount of motion
between the several dorsal vertebra, their complex structure, the anchylosis of the
sacrals, and the fact that the plates of the carapace lie between the scapula and the
ribs. In turtles the scapula lies inside, not outside, of the costal plates.

Dr. O. Jaekel, of Berlin, has described (Neues Jahrb. Min., 1, 1902, p. 127) an
interesting genus named by him Placochelys and regarded by hin as standing in
ancestral relations to the turtles. The body of the apanale is short and broad, and is
covered by an armor of thick small plates, all closely joined. There is no ventral
armor. The specimen was found in the lower portion of the Keuper. The well-
preserved skull shows that there were large supratemporal fenestre and that the
nasal openings were separate and far behind the end of the snout. These structures,
especially the first named, make it improbable that this reptile is at all closely
related to the turtles.

The discovery of Otocelus and Diadectes and Placochelys is like the capture of
so many strag glers and deserters from an army of heterogeneous composition.
From these prisoners we may learn something of the personnel and the equipment
of that army; but it would be unsafe to ee from the data obtained too wide
conclusions. From Plac ochelys we learn that in Triassic times there were broad and
short bodied reptiles of tortoise-like form and covered with an armor of small plates.
From Diadectes and Otocelus we discover that in Permian times there were more

30 FOSSIL TURTLES OF NORTH AMERICA.

elongated reptiles, in the skulls of which there were many chelonian characteristics
and whose bodies were protected by an armor of elongated plates overlying the ribs.
The stegocephalian genus Archegosaurus, of the Permian, possest a ventral armor
of elongated plates. We may confidently expect that in the Permian there will yet
be found an animal possessing such a combination of these characters, together
with other features, that we can recognize in it the ancestor of the order of turtles.
As to the relationships of the turtles to the orders of reptiles, other than the
Cotylosauria, only a few words can be said. The opinion is generally maintained
that their relationships are closer to the Plesiosauria than to any other order. Baur
(Jour. Morphology, 1, 1887, p. 98) has enumerated a number of resemblances
between the two groups. Among other things, he states that the pelvic arch of the
Nothosauride, among the most primitive of the Plesiosauria, is only comparable
with that of the Testudinata. It may be remarked that the pubes in both the turtles
and the plesiosaurs are greatly expanded forward and laterally. The ischia are not
so much alike, those of “the plesiosaurs being much more extended backward than
those of the turtles. Baur says that in the humerus of the lower Plesiosauria there
is an ectepicondylar foramen; but, according to Furbringer, there is only an
entepicondylar foramen. Baur does not compare the skulls of the two orders. The
strongest argument in favor of the relationships of the two orders is found in sup-
osed resemblances in the shoulder-girdles. Probably the best presentation of this
is to be found in Fiirbringer’s elaborate paper in the Jenaische Zeitschrift, Xxx1v,
1900, page 326. In that treatise the author takes the ground that the process
directed interiorly and inwardly from the scapula in the turtles is a procoracoid, a
view adopted by the present writer. Fiirbringer also holds that the procoracoid
was present in the Plesiosauria. This opinion ihe been accepted by some authors
and disputed by others. To the present writer the tract of bone in question appears
to be simply an extension forward and mesially of the scapula, whether that
extension is regarded as an acromion or a “ventral ramus” of the scapula. The
tract advanct gradually from the scapula to the midline, and there is no evidence
that it ever was a distinct bone. The fact that the two clavicles do not lie between
the ends of these processes does not appear to be decisive, for in numerous reptiles
the clavicles extend laterally on the scapula. Opposed to the idea that there are any
special relationships between the turtles and the plesiosaurs are the facts that the
latter always possess large supratemporal fenestra, the former never; and that the
most primitive plesiosaur, Lartosaurus, has the digital formula belonging to the
Diapsida and not that of the Synapsida.
At best, the relationship between the turtles and the plesiosaurs is not close;
and the most that we can say 1s that possibly the cotylosaurian stocks of the two
orders were a little closer to each other than to stocks that gave rise to the other orders.

THE GEOGRAPHICAL DISTRIBUTION OF LIVING TURTLES.

At the present day turtles exist in all the larger divisions of the earth, wherever
there is sufficient heat, at least a moderate amount of moisture, and a supply of food.
They occupy too all the warmer seas. Fig. 9 is an outline map that includes all the
lands and seas in which these reptiles are found: The areas occupied by the land and
fresh-water forms are indicated by parallel rulings, except that certain small islands
are made black; but no attempt has been made to show the distribution of the marine
species. Their realm may be taken as comprising all the seas between the ruled areas.
This map and those succeeding i it have been compiled with considerable care; but
itis not possible in all cases to determine exactly the limits of the groups.

GEOGRAPHICAL DISTRIBUTION. 31

A glance at fig. 9 will show at once the great influence of heat and cold and the
lack of moisture. In western Europe, warmed by the sea, the turtles are represented
by a species which ranges nearly as far north as St. Petersburg; while in Central
Asia none is known to occur north of Turkestan and the Himalaya Mountains.
The southern portion of Arabia and the greater portion of the Sahara Desert are
without turtles, on account of the dryness of the climate. In North America the
high and cold range of the Rocky Mountains supports no chelonian life. On account
of its dryness, the western coast of South America has no turtles; and the southern
extremity of the continent none, on account of its coldness. So much can we say
with regard to turtles in general; but when we come to study the different groups
we shall find that they are often absent from regions where the conditions appear
to be wholly favorable for their existence.

EQUATOR

Fic. 9.—Map showing geographical distribution of living turtles, excepting those strictly marine.
Occupied areas ruled with parallel lines, except some Snail islands: which are in solid black.

Fig. 10 is intended to display the distribution of the Cryptodira. It is seen to
differ from the previous map principally in that it shows that Australia possesses no
representatives of the superfamily.

ae

Fic. 10.—Map showing geographical distribution of the Cryptodira.

The absence of Cryptodira from Australia is evidence that that region has for
many geological ages been cut off from the regions to the north of it. It appears
certain that had the turtles of this superfamily once gained access to this region they
would have flourisht there. In numbers the Cryptodira exceed today all other

32 FOSSIL TURTLES OF NORTH AMERICA.

groups of turtles combined. Accepting the genera and species as described by Mr.
George A. Boulenger in his Catalogue of the Chelonians, there are 30 genera of
Cryptodira with 140 species; 21 genera of Pleurodira, with 24 species; 6 genera of
Trionychidz, with 24 species. The headquarters of the superfamily is North America.

RR Sp TS {, (ee, SN AAT”
ey ee > baat, Fa on “A ) NS at PD fee J
is My @ a » HK Bs po 4 4

p )

‘ sie es > wt
EQUATOR yey SS — —
|p ___ ce et NGsy

Fic. 11.—Map showing geographical distribution of the Chelydrida. Portions of the western
hemisphere and the island of New Guinea.

Fig. 11 shows the distribution of the Chelydride. The northern limits of the
family are somewhat uncertain. The same species, Chelydra serpentina, that occurs
in Canada, is found also in Ecuador, South America. Until recently it has been
supposed that the members of this family are confined to the New World; but J.
Douglas Ogilby has reported (Proc. Roy. Soc., Queensland, x1x, 1905, p. 11) the
discovery of a new genus and species, “Devista “mythodes, i in the Fly river, New
Guinea, the river that has furnisht likewise the remarkable turtle Carettochelys.
The New Guinea snapper has a length of 860 mm., the carapace being 330 mm.
long. This distribution of the snappers is even more remarkable than that of the
camels and tapirs.

\ \ /
YN Ree
Si Sy een a
N “ y w 8
Sea

Fic. 12.—Map showing distribution of the Dermatemydide.

Fig. 12 displays the distribution of the Dermatemydidz. This is one of the
decadent families of the order, for it abounded in genera and species in the Upper
Cretaceous of North America and still existed in reduced numbers during the Ter-
tiary. The family, now consisting of three genera and four species, is confined to
portions of Mexico and Central America.

As seen from fig. 13, the Emydidz have a wide distribution, occupying all the
habitable portions of North America, South America, Europe, rete and most of the

GEOGRAPHICAL DISTRIBUTION. 33

Kast Indian islands. ‘They are wholly missing from Australia and are conspic uously
restricted in Africa. Only 2 species occur in 1 the latter continent, and it is possible
that one of these was introduced by man, since it inhabits also the south of Europe.
Additional remarks on the distribution of the family will be found under the head
of Emydidz, on a subsequent page. Unless the genus Gyremys belongs really to
the Emydidz, the known members of the family appeared at about ihe same time

EQUATOR

Fic. 13.—Map showing geographical distribution of the Emydidz.

in America and Europe, in the Lower Eocene. It is remarkable that no members of
the group were able to find their way into Africa with the Testudinidz, for the latter
were establisht there by the time of the Upper Eocene.

The Emydide that occur in South America are all, without doubt, descendants
of those that entered that continent at a rather late period from North America.
This was probably during the Phocene. Only 4 species are known. Of these 1
belongs to Trachemys, represented by several species in North America, and 3 to
Nisei, a genus occurring also in eastern and southern Asia. Nucorra, however,

xy
aN

Fic. 14—Map showing geographical distribution of the Testudinide.

does not appear to be greatly different from Echmatemys of the Bridger beds, yet
distinct; and it is wholly probable that both Asia and South America received their
stock from our own country. The distribution of these turtles resembles that of the
tapirs. North America possesses at least 25 species of Emydide.

In fig. 14 we have a map representing the distribution of the Testudinide, at
present, or at least within historic times. It will be observed that North America,
which during the Tertiary was probably everywhere, except in the coldest parts,

34 FOSSIL TURTLES OF NORTH AMERICA.

inhabited by these land tortoises, presents only two very restricted areas. ho at
that time it abounded in representatives of the family, some of them of gigantic size,
it is now poor in species, there being only 3. Almost the whole of South America
is occupied by the family, but there are only 3 known species. Europe claims
2 species; while Asia possesses 7. Africa is the headquarters of the family, at
least 20 species occurring on that continent. These belong to 3 recognized genera.
‘The most remarkable f(ocue of the distribution of the Vestudinid is the occurrence
of species, some of great size, on islands far away from any large body of land, as the
Galapagos Islands Bind islands in the Indian Ocean. For purer discussion of this
subject the reader is referred to the treatment of the family on a succeeding page.

The geographical distribution of the Pleurodira is represented by fig. 15. It
will be seen that the species are almost wholly residents of the torrid and dhe south
temperate zones. A single species has an outlying colony on the ‘Tropic of Cancer,
at the head of the Red Sea. The wide distribution of these turtles is not surprising,
seeing that they are a very ancient group. The earliest species that are known to

S
belong to the superfamily are described in the present work and come from the

Upper Cretaceous of New Jersey and New Mexico.

Doubtless the group existed

= —— = J

Fic. 15.—Map showing the distribution of the Pleurodira.

during the Lower Cretaceous and probably during the Jurassic. In those early
days the land masses had connections very dierent from those now obtaining;
and these turtles were able to become diffused to regions now widely separated by
deep seas from the original home of the creatures. It erould appear more reasonable
to suppose that South America had received its original pleurodiran population
from North America, by the way of some Mesozoic land connection; but it is
possible that these immigrants reacht that continent from Africa. A considerable
number of authors, viewing the subject from different positions, have concluded that
there was, during the Mesozoic era, a land connection between South America and
Africa, which connection was interrupted about the beginning of the Tertiary.
The existence of such a bridge would enable us to account for the occurrence of
some closely related species in Madagascar and South America. These species are
usually referred to the genus Prdbeneutins but Baur regarded the Madagascar
species as belonging to the closely related genus Erymnoc helys. Two species of
Podocnemts are reported from the Middle Eocene beds of the F ayum, Egypt.
Inasmuch as Pleurodires once occupied a large part of the north temperate zone,
it is remarkable that they have not been able to maintain themselves there. The
first and the last that are known to have lived in North America flourisht during

GEOGRAPHICAL DISTRIBUTION. 35

the Upper Cretaceous. In England species existed during the Eocene and a species
of the same epoch has been described from India as a FH ydras pis, a genus now
existing in South America. It is worthy of note, too, that in North America the
Pleurodires apparently disappeared long before the Amphichelydia did, the stock
that gave origin to the Pleurodires. The Amphichelydia continued on into the
Bridger and the Uinta.

It will be observed from the map (fig. 16) that the Trionychide occupy the
habitable portion of North America east of the Rocky Mountains; Africa south of
the Sahara Desert; Asia south of the Sayanskii and Yablonoi Mountains and
between the Persian Gulf and the Caspian Sea; and most of the East Indian islands,
including New Guinea. Altho the oldest-known representatives of the Trionychide
have been found in the middle of the Upper Cretaceous of North America and altho
that continent is still inhabited by at least 6 species, it is Asia that furnishes the
greatest number of living forms of the family, at least 15 species having been
described from that region, including the islands appertaining to it. In Africa there
occur about 6 species, so far as now known. As in the case of the Cryptodires, the
trionychids have prest southward close to Australia, without having succeeded in

7

Fic. 16.—Map showing the distribution of the Trionychide.

reaching it, Pelochel ys cantoris having been reported from New Guinea. No Triony-
chide have been found in the Tertiary beds of the Fayum, Egypt. Considering
the fact that true trionychids antedate known pleurodirids, it appears strange that
the former were not able to reach Australia with the pleurodirids; more especially
since the trionychids are, and have been since the Judith River epoch, excellent
swimmers. A problem fully as hard to solve is the absence of trionychids from the
continent of South America. So far as we can judge, they might easily, within
rather recent geological times, have made their way thither from North America.
Again, Ameghino has described what he regards as a species of T rionyx from the
Cretaceous of Patagonia. The description 1s very brief and no figures have been
furnisht. If representatives of the superfamily had reacht the continent by the
time of the Upper Cretaceous it is remarkable that they were not able to maintain
themselves there. No region appears to be better adapted than this for river-loving
species of turtles. ;

In Europe we have another illustration of the fact that animals may be driven
from a region in which they have once obtained foothold. No species of the
superfamily now occupies that region; but numerous species did exist there during
the Eocene, the Oligocene, and the Miocene. It has not yet been determined
what the influences were that operated against them.

36 FOSSIL TURTLES OF NORTH AMERICA.

THE GEOLOGICAL DISTRIBUTION OF THE TURTLES.

In tables 1 and 2 the writer has endeavored to present in as accurate and effective
a manner as possible the chronological distribution of the fossil turtles of North
America, with the positions of the turtle-bearing beds and the level at which each
species has been found. ‘Table 1 represents the principal divisions and subdivisions
of the Mesozoic age, except the Triassic, while table 2 deals in hke manner with the
Cenozoic. No small difficulty is experienct in the preparation of such tables. The
limits of the larger formations and the periods which they represent have not
received general acceptance; and when we come to consider the smaller divisions
and the correlation of deposits in distant regions there are in many cases widely
divergent views. Again, in the collection of the fossils there has often been too
little care exercised in preserving records of localities and levels. An interroga-
tion mark (?) preceding any generic name indicates that the species immediately
succeeding possibly does not belong to the level indicated.

‘TABLE 1.—Princt pal divisions of the Furassv and Cretaceous, with the Species of turtles known from each,

Denver. | ?Glyptops depressus.

Arapahoe. Adocus? lineatus, Plastomenus? punctulatus, P. insignis, Aspideretes vagans.

Baéna marshi, B. hatcheri, Eubaéna cephalica, E. latifrons, Thescelus insil-
iens, T. rapiens, ?Naiadochelys ingravata, Basilemys sinuosa, Compsemys
victa, C.? obscura, Helopanoplia distincta, Aspideretes foveatus, A. beech-
eri, A. austerus, A. fontanus, A. vorax.

Laramie.

Fox Hills. No turtles known.

Bear Paw. No turtles known. Eastern Recion.
= 7 (Greensand, etc., approximately
Baéna_ callosa, B. equivalent to Pierre, etc.)
antiqua, Boremys — Bothremys cooki, Taphrosphys sul-
pulchra, Neuranky- catus, T. longinuchus, T. leslianus,
lus eximia, Chari- T. strenuus, T. molops, T. nodo-
temys captans, sus, T. dares, Amblypeza entellus,
Polythorax missuri- Osteopygis emarginatus, O. gibbi,
SOSIS, Basilemys O.robustus, O. chelydrinus, O.ero-
variolosa, B. im- sus, O. borealis, O. platylomus, oO.
Judith River. bricaria, ?Compse- sopitus, Catapleura repanda, C.
Gere ae ponderosa, Peritresius _ornatus,
oot Pierre. specta rr aston Lytoloma angusta, L. jeanesi, Die
menus costatus, wielandi, Erquelinnesia molaria,
Aspideretes fovea- Rhetechelys platyops, ?Neptu-
Mesongiee tus, A. coalescens, | nochelys tuberosa, Atlantochelys
A. splendidus, A. | mortoni, Adocus beatus, A. puncta-
beecheri. | tus, A. lacer, A. syntheticus, A.
| agilis, A. pravus, Agomphus turgi-
=|| dus, A. petrosus, A. tardus, A.
Clagget. Toxochelys latire- pectoralis, A. firmus, A. masculi-
mis?, Porthochelys | nus, Zvygoramma striatula, Z. micro-
Eagle. browni, Archelon | — glypha, Homorophus _ insuetus,
ischyros, A. marsh. Amyda? prisca, A.? halophila.
Toxochelys latiremis, T. serrifer, T. brachyrhina, T. steno-
Niobrara pora, T. elkader, T. procax, T. bauri, Cynocercus incisus,
Porthochelys laticeps, Protostega gigas, P. potens, P.
advena.
Benton. Glyptops pervicax, Desmatochelys lowi.
Dakota. No turtles known.
Washita. Glyptops? belviderensis.
. Lower Fredericksburg. No turtles known.
Cretaceous.
Trinity. Glyptops celatus (In Potomac beds).
Morrison. Glyptops plicatulus, Probaéna sculpta.
Jurassic. Unk papa. No turtles known.

Sundance. No turtles known.

GEOLO

Tasie 2.—Princtpal divisions of th

|

GICAL DISTRIBUTION.

e

Cenozoic, with the names of the turtles found 1m each.

Chelydra serpentina, Clemmys percrassa, C. insculpta, Chrysemys timida, Trachemys petrolei, T.
bisornata, T. trulla, Terrapene marnochi, T. eurypygia, ?T. canaliculata, Testudo laticaudata, T.

Macroclemys floridana, Deirochelys floridana, Trachemys sculpta, T. jarmani, T. euglypha,
Pseudemys extincta, Terrapene putnami, Testudo crassiscutata, Platypeltis ferox ?

Blanco. Testudo turgida, T. pertenuis, T. campester, Clemmys hesperia (Rattlesnake beds).

| Pleisto- |

|) -cenes hexagonata, T. atascose.

_—— ———

Peace

| Creek.

Pliocene. | ae) —_=
| eee ES :

| Upper. Trachemys hilli,

Miocene.

| Prains AND Mountain REGION.

ede, T. hollandi, T. impensa, T. niobra-
rensis, T. gilberti, T. undata, T. klettiana. lulosa.

|
Testudo orthopygia, T.

Middle. Clemmys saxea, Testudo pansa, T. osborniana, T. farri.

Lower. Testudo vaga, T.

ae x ae ;
ohn Day.) Stylemys oregonensis, S. capax, S. conspecta, ?S. calaverensis.

arenivaga, T. peragrans, T. inusitata, T. emilia.

Yorktown Epocu or Atrantic REGIon.

Syllomus crispatus, Procolpochelys gran-
deva, Amyda? buiei, A.? lima, A.? cel-

Stylemys nebrascensis, Testudo thomsoni, T. laticunea, T. ligomia, T.amphithorax, T.

D. ?Echmatemys septaria (Washakic), ?Amyda egregia

(Washakie).

C. Anosteira ornata, Amyda _ salebrosa, Platypeltis

serialis, P. postera.

ternon undatum, C. hebraicum, Baptemys wyomin-
gensis, ?B. fluviatilis, Anosteira ornata, Clemmys
morrisie, Echmatemys wyomingensis, E. haydeni,
E. stevensoniana, ?E. septaria, E. arethusa, E.
cyane, E. shaughnessiana, E. ocyrrhoé, E. egle,
E naomi, E. pusilla, E. latilabiata, ?E. polycypha,
terrestris, Hadrianus corsoni, Achilemys
allabiata, Plastomenus thomasi, P. visendus, P.
tantillus, P. eedemius, P. molopinus, Aspideretes
guttatus, A. ellipticus, A. grangeri, Amyda uinta-
ensis, A. scutumantiquum, A.? concentrica, A.
francisce, A.? exquisita, A. mira, A.? tritor,
Temnotrionyx manducans, Platypeltis serialis, P.
trionychoides, P, heteroglypta, P. extensa.

A. Anosteira radulina, Hvbemys arenaria, Amyda equa.

Baptemys tricarinata.

Rocky Mountain Recion.

| Baéna arenosa, Kallistira costilata, Notomorpha gravis,
Echmatemys lativertebralis, E. cibollensis, E. me-

E. testudinea, E. euthneta, Hadrianus

majusculus, Plastomenus catenatus, P. corrugatus,

P. communis, P.? leptomitus, P.? lachrymalis, P.?
fractus, Amyda cariosa, A. radula, Platypeltis serialis.

| Baéna escavada, Alamosemys substricta, Hoplochelys

| Aspideretes singularis.

Oligocene.) Brule. quadrata, T. cultrata.
ichrauhiae leucopotamica.
J Ii
Upper. | Uinta. Winpdaccacs
Cenozoic. ie
Eocenc. Middle. Bridger.
tes
Wind —
- River. Maes
Wasatch. gaulax,
Lower.
| Torrejon.
| | Puerco.

?Hoplochelys crassa, Conchochelys admirabilis, Aspideretes sagatus,
cencis, A.? nassau (Fort Union beds).

Xenochelys formosa, Graptemys inornata, Testudo brontops, T. exornata, Platypeltis |

Baéna emilix, Echmatemys callopyge, E. uintensis, Hadrianus tumidus, —

Gutr Reoion.
Jackson epoch.

B. Baéna arenosa, ?B. clara, B. sima, B. riparia, Chis- Hadrianus schucherti

| Eastern Recon.

| Lembonax — polemi-
cus, L. insularis,
L. propylaus, Che-
lonia_ parvitecta,

Agomphus oxyster-
num, Amyda? pen-
nata, A.? virgin-
jana.

saliens, H. paludosa,

A. puer-

38 FOSSIL TURTLES OF NORTH AMERICA.

In North America no turtles are known to have existed in deposits below the
Morrison beds of the Upper Jurassic. Dr. Edward Hitchcock has indeed assigned
to the tortoises certain tracks observed by him in the Triassic sandstones of Massa-
chusetts and Connecticut; but, while there is no improbability that turtles occurred
there and then, there is no certainty of it. As is seen from table 1, 2 species of
turtles, both belonging to the Amphichely dia, have been found in the Mowncon beds
of the Rocky Mount: un region. ‘hese beds are sometimes regarded as belonging to
the Lower Cretaceous, equivalent to the Wealden of Europe, Bad it is more probable
that they correspond to the Kimeridge Clay or the Purbeck (Fraas, Zeitschr. deutch.
geol. Gesellsch., Litt, 1902, briefl. Mitth., p- 59) or even a little lower. So far as now
aor n, no other group than the Amphichelydia are represented until we reach the
Benton, of the Upper Cretaceous. I[n the lowest division of this there occurs an
undoubted marine turtle belonging to the Cryptodira. A species of Glyptops is
found in the Potomac beds near Washington, District of Columbia, and another
species of probably the same genus in the Washita beds of Kansas.

‘Turtle remains are not uncommon in the Niobrara beds of Kansas, but when we
come to examine the list, we find the species not numerous, and they belong to only
four genera. The species of Toxochelys and of Porthochelys z appear to have lived in
the Niobrara ocean near the coasts. The species of Protostega, on the other hand,
evidently ventured far out on the high seas. Toxochelys and Porthochelys appear to
have continued on into the Pierre; Pecionte ga was there replaced by, or transformed
into, the huge Archelon.

About the middle of the Upper Cretaceous, conditions were favorable for the
existence and the inhumation of many species of turtles. These are found now in
two widely removed regions and in deposits made under widely different conditions.
On the Atlantic border, especially in New Jersey , occurs a series of marine deposits
from which have been derived about 40 species of turtles, including g species
of Pleurodira and 2 species of Trionychidaw. The remainder are Cry ptodira, among
them many coast-inhabiting Thalassemydidz, all of which were probably furnisht
with jaws fitted for crushing hard mollusks and crustaceans. The family of Dermate-
mydide, represented now by only 3 genera and 4 species, appear in great numbers
and variety, especially in the New Jersey Cretaceous greensand. Whence this
assemblage of turtles came we have no clue. Scant remains indicate the existence
of two species of large marine turtles, 4tlantochelys and Neptunochelys.

In the heart of the continent at nearly the same time, possibly a little earlier,
there were being laid down fresh and brackish water deposits, now known as the
Judith River beds. They are found in Montana and British America, and have
furnisht about 15 species of turtles; but these are quite different from those of the
Atlantic coast deposits just mentioned. ‘There are, indeed, 4 or 5 species of triony-
chids of the genus A spideretes, a genus living now in Asia, a species of Plastomenus,
and 3 or 4 species of Dermatemy didz:; but che latter belong to genera distinct from
uhese found in the New Jersey deposits. In these Judith River beds reappear rep-
resentatives of the Amphichely dia, turtles which we have found to characterize the
Upper Jurassic and the Lower Cretaceous. In America the turtles of this group
appear generally to have avoided true marine conditions.

Succeeding the Pierre and the Fox Hills epochs came that of the Laramie. In
the fresh and brackish water deposits laid down during this time there were buried
remains of a great variety of turtles, but inforainately these remains are usually
very fragmentary; 16 species are recognized as belonging here. Their relationships
are close to the turtles of the Judith River beds, some species being as yet undis-
tinguishable. The conditions under which the two deposits were laid down were so

GEOLOGICAL DISTRIBUTION. 39

similar that there 1s no wonder that the faunz did not ditter greatly. Inthe Laramie,
as in the Judith River, there were Baénidz and Trionychide. The Dermate-
mydidz are represented by at least one species, Basilemys sinuosa, not greatly
different from B. vartolosa of the Judith River. The Pleurodira appear to be
represented by one species, Natadochelys ingravata, from New Mexico.

On entering the Tertiary there is no striking change in the turtle fauna. In the
Fort Union, the Puerco, and the Vorrejon, ere are yet Prionychide, Dermate-
mydidz, and Baeénidz. Representatives of the same families pass up into the
Wasatch. Here, however, new elements enter, the Emydidz and the Testudinide.
It is not improbable that Gyremys spectabilis of the Judith River beds is an emyd,
but the group 1s unmistakably represented 1 in the Wasatch by Echmatemys, a genus
in some respects highly specialized. ‘The Testudinidz are represented by the
genus Hadrianus, the oldest-known genus of the family. All these Wasatch turtles
inhabited either the land or the fresh waters of streams.

In the Atlantic region we have nearly contemporaneous deposits; and in them
we find fragmentary remains of a few probably marine turtles and of Trionychide.

The Wind River beds have so far furnisht only a single species of Baptemys, and
the humerus, 187 mm. long, of a trionychid.

The Bridger beds of Wy oming are exceedingly rich in turtle remains, as they
are also in ha bones of crocodiles and mammals. The Baénidz were numerous in
species and individuals. Only 2 genera of dermatemyds have been found. Emy-
did abounded, and Triony ines ran riot. In addition to these there were a few
species of Plastomenide. All together, there are 50 or more species of turtles
described from the Bridger Eocene. The abundance of Baénide and especially
of the Trionychidze shows that there were numerous streams and lagoons; and this
conclusion is confirmed by the presence of many species of eewendiles: ‘The occur-
rence of the great turtle Hadrianus seems to indicate the proximity of dry land.

Nearly calle the species of Bridger turtles occur in the lower portion, that known
as level B. No turtles have yet been described from the limestone bands, but
fragmentary remains occur there. These bands appear to have been laid down in
Shaler lakes.

So far as known the turtles of the Uinta beds belong to genera found in the
Bridger beds. No Plastomenide have been found, and the Baénidz appear for the
last time in our calendar.

During the Oligocene epoch the scene, for the student of turtles, shifts from the
sea shore and the mountain regions to the Great Plains. In the lowest division, the
Chadron or Titanotherium beds, are found 1 trionychid, 1 dermatemyd, and
1 emyd, silent witnesses of the presence of streams. On the other hand, there were
numerous species of Testudinide, or dry-land tortoises, some of which attained a
large size. Of Stylemys nebrascensis great numbers of shells have been found in
Sauch Dakota and Colorado, in the Bale clays, or Oreodon beds. Species of
T estudo were more abundant in the same deposits in Colorado. There can be no
doubt that at this time the climate of the Plains region had become arid and the
streams few. A similar climate appears to have prevailed in the John Day region
of Oregon, where 2 or 3 species of Stylemys abounded, but, so far as iGroneh. no
other turtles.

The Miocene deposits of the interior of the continent are characterized by the
presence of species of T estudo, many of them of large size, resembling the gigantic
tortoises of the Galapagos Islands. Sixteen species are described. In the. “Middle
Miocene of Oregon there has been found a species of Clemmys (C. saxea); 1n the
Upper Miocene of Kansas, Trachemys hill. In the Yorktown beds of the Atlantic

40 FOSSIL TURTLES OF NORTH AMERICA.

Slope are found two species of the Chelonidz and fragments of three species of
Trionychida. We can not doubt that in the streams of the Mississippi Valley and
eastward there was an abundant population of water-loving turtles, but farther
westward this order of reptiles was represented principally by the land tortoises.

During the Pliocene the land tortoises continued to predominate, especially in the
interior region. [hree species are known trom the Blanco beds of Texas. In deposits
of apparently the same age in Oregon there has been found a species of Clemmys.

In the Peace Creek beds of Wionea: belonging apparently to the Upper Pliocene,
there are found, with one large T estudo, numerous Emydidz and a species of
Chelydride. These are closely prelate to Species } yet living i in that region. Among
the numerous turtle bones put in the writer's s hands foil Hillsborough County,
Florida, are many fragments that evidently belonged to yet undescribed species of
Emydide and Triony chide.

In the scattered deposits of the Pleistocene, 1 in which we might expect to find
remains of turtles, we discover a few species; and these present a astill closerapproach
to those now inhabiting the same territory. In what probably corresponds to the
Equus, or Sheridan, beds of the region west of the Mississippi River have been
discovered a species of Chrysemys, 3 species of Trachemys, a species of Terrapene,
and 3 species of Testudo. It is worthy of note that no Tee aera the size
that was reacht by species of the genus during the Miocene and the whole of the
Pliocene. In the Atlantic region, in caves and superficial deposits, have been found
remains of the snapping- iretles the sculptured turtle, another supposed species of
Clemmys, and one or more species of box-tortoises.

Briefly let us consider the geological history of the turtles of other regions.

The earliest known turtle remains have been found in the Middle Tiaesies the
Muschelkalk, of Germany. Huene (Palzont. Abhandl., x, 1906) has described
a few cervical vertebra which he regarded as probably having belonged to crypto-
diran turtles. In the Upper Triassic of the same country, the Keuper, has been
found Proganochel ys, a nearly complete shell of which has been described by E. Fraas
(Jahresh. V er. Naturk. Wiirrt., Lv, 1899, p. 401). The present writer believes that
this turtle belonged to the Amphichelydia, and it is probable that the cervical
vertebra from ae Muschelkalk belonged to some turtle of the same group.

The next oldest known turtle, known only from impressions of the carapace on
slabs of rock, is Protochelys strickland1, from the Stonesfield slate, of the Great
Oolite, of Oxfordshire, E ngland. It belongs probably to the Amphichelydia.

In contrast to the scanty chelonian population of the North American Upper
Jurassic, that of Europe was extremely numerous. From the Jurassic at Solothurn,
Switzerland, about 15 species have ‘been described. From deposits of approxi-
mately the same age in Germany, France, and England, numerous other species
have been reported. Many of the species have come from the Kimeridge, of the
upper portion of the Great Oolite, a formation found in England, France, and
Germany, and belonging near the level of the Morrison beds of Wyoming, as
already stated. The principal g genera described from the Upper Jurassic of Europe
are Ple urosternon, Plat yc helys, IB le stochelys, Idioc helys, Hydr opelta, Parac helys,
Acichelys, Thalassemys, Ste gochelys, and Tropodemys The first two belong
without doubt to the Amphichely dia, Pleurosternon being closely related to Glyptops
and Platychelys to Probaéna. Craspedochelys and Ple siochelys are almost certainly
not Pleurodira and may be referred provisionally to the Amphichelydia. The
other genera are to be referred to the Thalassemydida, a family of Cryptodira.
Sais turtles are found a little higher up in the European Jurassic, 1 in the Purbeck

GEOLOGICAL DISTRIBUTION. 41

and Portlandian; likewise, in the Wealden, of the Lower Cretaceous deposits of
approximately the age of the Trinity and Potomac. In the Portlandian is found a
species of Pleurosternon. In the Wealden occurs the genus Tretosternon, which
may have given origin to the Dermatemydidz.

In the Gault, at the base of the Upper Cretaceous of England, have been found
remains of a large turtle which is called by Lydekker Chelone jessont (Quart. Jour.
Geol. Soc., xLv, 1889, p. 231). While it is possible that this species belonged to the
Chelonidz, it is improbable that it was congeneric with our living green-turtle. It
would be more proper to call it Cimochelys jessont.

The Cambridge Greensand, of the Cenomanian, near the time of the American
Dakota or Benton, furnishes a number of turtles. “These are represented by skulls
alone and are placed in the genus Rhinochelys. heir affinities are uncertain, but
they are neither Pleurodira nor Trionychoidea. The genus seems not to be repre-
sented in America.

In the Lower Chalk, Turonian, of Kent, England, are found remains which are
assigned by Lydekker (Cat. Chelonians, 1889, p. 34) to Chelone benstedt. For the
reason noted above, this species ought to be called Cimochelys benstedi, as it was
named by Owen. The Turonian was deposited approximately at the time of our
Niobrara beds.

In the Upper Cretaceous of England and the continent is found a huge marine
turtle, Allopleuron hoffman; its costals are greatly reduced. In Italy has been
found another large sea-turtle, Protos phargis, reminding us of Protostega and
Archelon, of the American Upper Cretaceous.

In the Upper Cretaceous of Provence, France, has been discovered the remark-
able turtle, Polysternon. Besides mesoplastra it possesses a pair of bones between
the hypoplastra and the xiphiplastra, and the pelvic bones are sutured to the xiphi-
plastra. It 1s regarded as a pleurodire; and it appeared about the time that this
group presented itself in America.

During the Tertiary period the history of European turtles appears to have run
on much as it did in America, altho in each country the history had its peculiar
features. Osborn (Ann. N. Y. Acad. Sci., x11, 1899, p- 7) finds that America and
Europe had a similar mammalian fauna throughout the Lower Eocene, but that
there followed a Middle and Upper Eocene interval of faunal separation of the two
countries; while again there was an approach, from the beginning of the Oligocene
onward until the late Pleistocene. With respect to the turtles it may be said that
the two regions were farther apart at the beginning of the Eocene, converged to
perhaps the middle of the Pliocene, then diverged.

In the London Clay of England is found Eosphargis, the earliest representative
of the Athecae. In Belgium at the same time there existed Pseudotrionyx, a relative
of the living Carettochelys. In England there were yet two species of Pleurodires.
So far as known, the group was not represented at the time in America. In Lurope
there were no Amphichelydia, no Dermatemydidz, no known species of Plasto-
menide, and no Trionychide. ‘The species of Argillochelys may belong to the
Cheloniide. Species referred by Lydekker to Chrysemys represent the Wasatch
Emydide, while Homopus comptont represents Hadrianus.

The Middle Eocene of Europe witnest a great multiplication in the number of
Trionychide. Species referred to the yet living Asiatic genus Ocadia, of the
Emydide, resembled the Bridger genus Echmatemys. The Bridger epoch differs
from the European Eocene in its numerous species of Baénide.

During the Oligocene, Europe possest numerous Trionychide. Doubtless in
America, too, they existed in numbers, but they have mostly escaped preservation.

42 FOSSIL TURTLES OF NORTH AMERICA.

America at that time yet harbored Dermatemydide; while Europe gave asylum to
Chelydride and to the peculiar genus Ptychogaster.

During the Miocene, land tortoises, Vestudinidz, abounded in both America
and Europe, turtles especially characteristic of dry lands. Europe possest various
genera of Emydidz and species of Chelydra, a genus now found only in North
iGaatier but apparently a late immigrant thither.

There are evidences that during the Phocene the turtle population of Europe
diminisht in genera, species, and probably in individuals. “Trionychidz were still
found in Italy. , but are not known after this time in Europe.

An interesting region for the student of chelonians is found in India. Here
numerous species of Trionychide, Emydide, and Testudinide have been exhumed
from late Tertiary; but most of the forms < appear to belong to existing genera.

From the Upper Eocene fluviomarine beds of the Fayum of Egypt we have
recently secured a most interesting and instructive addition to our knowledge of
the turtles of that time, Dr. C. W. Andrews having described g species from Thee
beds. One of these 1s a species of Psephophorus, related to Dermochelys. Of
Testudo there are 3 species, a shell of one of which had a length of 1500 mm. A
portion of the skull of a supposed species of Thalassochelys is also described. Of
Podocnemis there are 2 species. Besides these, a new genus of Pleurodira, Ste-
reogenys, with remarkable characters, is made known to us.

We must not omit to mention that remarkable Pleurodiran turtle, Mrolania,
which was originally described from remains found in Pleistocene deposits on
Lord Howe Teliad. east of Australia. A second species was afterward discovered
in Queensland, Australia; and more recently Dr. A. S. Woodward has described
a third species from northern Patagonia. Outside the remarkable structure of
this turtle, it becomes interesting for the reason that its presence in the regions
named appears to confirm the theory that there was once land connection between

Australia and South America.

DESCRIPTION OF GROUPS AND SPECIES. 43

DESCRIPTION OF GROUPS AND SPECIES.

Order TESTUDINES Batsch. Turtles and Tortoises.

Reptiles with the body relatively short and broad. Quadrate bone immovably joined to the
pterygoid, the prootic, and paroccipital; its outer surface excavated to form a tympanic cavity.
Paroccipitals not consolidated with the exoccipital. Vomer single, if not missing. Pterygoids
closing the palate by their inner borders. Teeth never present; the jaws always armed with a
horny covering. Nasal opening single. Dorsal ribs each with a single head; at least the anterio1
ones intervertebrally attacht. A nuchal bone always present. Cervical vertebra eight; dorsals
ten. Epiplastra (clavicles) and at least six other bones present in the abdominal wall. No
sternum or sternal ribs ever developt. Each half of the pelvis composed of three bones, all con-
tributing to the acetabulum. Four limbs always present. Humerus with ectepicondylar passage.

This order of Reptilia is divided into two suborders, the ATHEC# and the
‘THECOPHORA.
Suborder ATHEC Cope.

Turtles which retain the primitive dermal armor, with at least traces of the subdermal
expansions connected with the ribs.

Of this suborder there is no known representative from North American
deposits, unless possibly certain dermal bones that have been found to accompany
the remains of Basilosaurus (Zeuglodon) belonged to some otherwise unknown
species of the group. This is improbable, however, as shown by Dames (Pal.
Abhandl., v, 1894, p. 220). In Europe the suborder is represented by Eosphargis,
of the London Clay of England, by Psephophorus, of the Oligocene and Miocene ot
the Continent, and perhaps by Pseudosphargts, of the Upper Oligocene of Germany.
The latter genus is based on a very imperfect skull; and, while presenting many
resemblances to Dermochelys, is not regarded by the present writer as being at all
certainly a member of the Athece. This turtle possest descending plates from the
parietals to the pterygoids.

Suborder THECOPHORA Dollo.

Turtles in which the primitive dermal armor has become obsolete or abolisht. Always a
more or less complete carapace formed by at least the expansions of the ribs, the nuchal bone
and with rare exceptions a series of neurals; usually a very complete shell formed by the bones
mentioned, together with series of peripherals and a varying number of plastral bones. Skull
always furnisht with descending parietal plates.

This suborder, containing the vast majority of turtles, living and extinct,
consists of four superfamilies, the AMPHICHELYDIA, the PLEURODIRA, the CryPTo-
pirA, and the TRIoNYCHOIDEA. Of the first there are no living representatives.

Kry To SUPERFAMILIES OF | HECOPHORA.

1. Mesoplastra present or absent. If absent, hinder lobe of plastron with rough scars for umion with
pelvic bones except in Plesiochelyide.

a'. Mesoplastra always, so far as known, present; no plastrall/scais.r-..2 ae Amphi helydia

a’. Mesolpastra present or absent; rough scars on hinder lobe of plastron Pleurodira
2. Mesoplastra always absent; no sutural scars on plastron.

a’. Peripheral bones always present....-..-+--+---+2+25+000- TEBE Cryptodira

a’. Peripheral bones present only in one genus now existing. ae Trionychotdea

Superfamily AMPHICHELYDIA Lydekker.

Thecophorous turtles having a carapace composed of neural, costal, and peripheral bones
and a plastron in which the epiplastra are in contact with the hyoplastra. Mesoplastra usually,
perhaps always, present. Intergular and inframarginal scutes probably always developt.

44 FOSSIL TURTLES OF NORTH AMERICA.

Skull essentially cryptodiran in structure, but with various primitive elements. Neck short,
the vertebra little differentiated. Limbs, so far as known, fitted for w alking.

This group was establisht by Mr. Richard Lydekker, to include, as he states,

a number of generalized late Mesozoic forms which may be regarded as allied to the

earlier (and een unknown) progenitors of the Pleurodira anu Cryptodira. He
characterized them as having a shell constructed on the plan of that of the Crypto-
dira and Pleurodira, in which mesoplastral bones and an intergular shield are
developt. ‘The pubis may articulate, without sutural union, with the xiphiplastron.
At the time he wrote the skull and neck were not known. The coracoid and the
humerus were regarded as being of the pleurodiran type. The genera included
were Pleurosternon, Baéna, and ”Platyc helys. (Lydekker, Cat. Foss. Rept. Brit.
Mus., pt. 111, 1889, p. 204.)

In 1890 (Amer. Naturalist, xxiv, p. 530) and 1891 (Proc. Acad. Nat. Sci. Phila.,
p. 411) Dr. George Baur, working on materials at Yale University, added greatly
to the knowledge of the group, regarded by him asa suborder. He likewise furnisht
a dehnition of the group. Lhe present writer (Bull. Amer. Mus. Nat. Hist., xx1,
1905, p- 137), having studied well-preserved remains of Baéna trom the Bridger
beds, was enabled to make further additions to our knowledge of the Amphichelydia
and to correct some of Dr. Baur’s statements and generalizations.

In this superfamily the plastron appears to en in all cases more or less closely
joined to the carapace by sutural union with the peripherals, and in the Baénidz
the union 1s strengthened by powerful axillary and inguinal buttresses. In all
forms known to belong to the group there are w ell-dev elopt mesoplastra; but since
these bones have been abolisht from the plastron of all the Cryptodira and from
that of most of the Pleurodira, there seems to be no good reason to suppose that they
might not have been supprest in the case of some of the Amphichelydia. Accord-
ingly the writer has ventured (Bull. Amer. Mus. Nat. Hist., xx1, pp. 144, 167) to
include provisionally in the superfamily the Plesiochelyida. Nothing 1s known
certainly of the members of the family except the shells.

On the c carapace of the Amphichely dia, besides the scutes found in such turtles
as the Emydide, there may occur supernumerary vertebrals, costals, and supra-
marginals. On the plastron there are, in all known cases, intergulars and full series
of inframarginals. ‘The boundaries between the scutes are jiable to vary in their
positions. The sulcus between the paired scutes of the plastron especially is often
found wandering far from the midline. It is as if the limits of the scutes had not
in these early forms yet become firmly establisht. In the skull there are such primi-
tive elements as distinct nasals and lacrimals. The temporal region 1s always
covered over and the quadrates are notcht for the passage of the “stapedial rod.
The pterygoids never have the wing-like expansions that characterize the Pleuro-
dira; and, unlike the latter, the pterygoids push themselves backward between the
quadrates and the basioccipital and fhe basisphenoid.

The cervical vertebra may, as in Glyptops, be all biccelous, or, as in the Baénidee,
one end of most of them may be convex. The neck was short and the differentiation
of the cervicals had progrest so little that probably these turtles could protect their
heads neither by withdrawing them within the shells as do the Emydidz, nor by
laying them on one side beneach the front border of the carapace after the manner
of fhe Pleurodira.

In the Pleurosternidze and the Baénidz, whose limbs are now known, these were
fitted for progression on land. Doubtless they were inhabitants of the waters of
lakes and rivers and were good swimmers, but there was no special modification of
the limbs for swimming.

PLEUROSTERNIDA. 45

In addition to the families Pleurosternide and Baénidz here treated, and the
Plesiochelyidz provisionally included, the writer refers to this superfamily with-
out hesitation the Triassic genus Proganochelys, which has recently been so well
described by Dr. E. Fraas. SWachoue doubt this genus forms the type of a distinct
family, the Proganochelyide, characterized by the broad shell, the hinder border of
which is deeply scallopt, by the extremely broad vertebral scutes, by the series of
supramarginal scutes in front of the first costals and behind the last ones, and by
the mesoplastra, which meet at the midline and are enormously expanded at their
outer ends. The genus Proganochelys is the oldest turtle of which we have any
considerable know ledge, coming. as it does from the Keuper, of the Trias. Cervical
vertebre of a genus named Chelyzoon have been described by Huene from the
Muschelkalk of Germany. They have been supposed to belong to the Cryptodira,
but there is little reason why they should not be referred to fae Amphichely dia.

The most recent certainly known member of this subfamily comes to us from the
Uinta beds of Utah. Pleurosternon miocenum Portis has been described from the
Tertiary near Lausanne, Switzerland, but it is based on a badly damaged plastron.

Axillary and inguinal buttresses feebly developt. Plastron aaa not notcht behind;
mesoplastra usually not narrowed at midline . xe .. Pleurosternide
Axillary and inguinal buttresses strongly developt; mesoplastra narrowing toward midline.. Baénida

Family PLEUROSTERNID& Cope.

A family of Amphichelydia. Carapace with costals articulated to the peripherals by close
sutures and by gomphosis of ends of ribs. Plastron joined to the carapace by sutures and by
narrow axillary and inguinal buttresses; the former ascending to the first costal, the latter
attaining the borders of “hie fifth and sixth costals at their junction. In Feloc helys the union of
carapace and plastron probably less intimate. Mesoplastrals meeting broadly at the midline,
not much expanded toward the outer ends. Exposed surfaces of carapace and plastron tuber-
culated or shagreened. Intergulars and inframarginals present. Skull elongated and pointed;
the bones mostly finely tuberculated. The cervical vertebra are biconcave. Coracoids
distally expanded.

So far as the writer knows, the name Pleurosternidz for this family was proposed
by Prof. Ek. D. Cope in 1868 (Proc. Acad. Nat. Sci. Phila., p. 282) and was employed
by him at various times afterward. He regarded it as a family distinct from the
Baénidew. Both families appear to have been alw ays included by him among the
Cryptodira. Lydekker (Cat. Foss. Reptilia, 111, p. 205) includes in it the Baénide.
Baur (Proc. Acad. Nat. Sci. Phila. 1891, p. 428) thinks it better to leave Baéna ina
distinct family, nearly related to Pleurosternon. “To the present writer each group
appears to be worthy of family rank. The genus Helochel ys, of the Cenomanian of
Germany, evidently belongs with the Pleurosternide. Pleurosternon is found in the
Purbeck and Portland Oolite of England. A species described by Roemer as
Emys menket, from the Wealden of ‘Germany, is believed to belong to Pleuro-
sternon. Portis has described P. miocenum from the Tertia ary near Lausanne,
Switzerland. In our own country, it appears that Glyptops existed from the
Upper Jurassic through the Lower Cretaceous (G. celatus) and the Benton (G.
pervicax) into the Denver (G. depressus) of the uppermost Cretaceous.

Genus GLYPTOPS Marsh.

Carapace deprest. Exposed surfaces of the shell rough with small tubercles and twisted
ridges. Neurals hexagonal, with the broad end in front. Costo-marginal sulci mostly below
the costo-peripheral sutures. Axillary buttresses reaching border of first costals. Inguinal
buttresses each entering an excavation at lower borders of fifth and sixth costals. Mesoplas-

40 FOSSIL TURTLES OF NORTH AMERICA.

trals joining extensively at the midline. Bridge about twice as broad as long. Inframarginals
almost wholly on the plastral bones. Plastron with hinder lobe not shortened and not notcht
behind. Pelvis not suturally articulated with the plastral bones. Skull pointed anteriorly;
most of its surface bones finely tuberculated. Bones of lower jaw smooth; the symphysis
short.

This genus was establisht by Professor Marsh in the year 18go (Amer. Jour.
Scl., XL, p. 177), his type being G. ornatus, collected in the Upper Jurassic of
Wivontne: This species is apparently identical with Cope’s Compsemys plic atulus.
A comparison of specimens of Compsemys victus Leidy with Cope’ S species just
mentioned makes it certain that the two forms are not congeneric. Compsemys
plicatulus must therefore be removed from Compsem ysya and Marsh’s genus Gl yptops
becomes available. The eas ie by Cope of various species oe Jurassic and
Cretaceous turtles to Compsemys was evidently due principally to supposed resem-
blances inthe sculpture; but all of these species, except the type, C. victa, must be
referred to other genera. ‘There are no evidences that C. victa possest mesoplas-
tra. The total absence of distal prolongations of the costals for insertion in the
peripherals of C. victa and their presence in G. plicatulus sufficiently separate them
generically.

To Gly ptops is provisionally referred G. pervicax, which in some respects
approaches more closely Pleurosternon, more especially in having the plastron
slightly notcht behind. On the other hand, the bridge is longer than in Glyptops
plicatulus. It is not improbable that it represents an undescribed genus.

It is to be noted that usually when authors have referred to the genus Compsemys
they have had in mind the species C. Cane ae because its Ghercrer: were well
known through Professor Marsh’s and Dr. Baur’s descriptions; whereas, little is
even now known about C. victa. For these references the writer’s Bibliography and
Catalogue of the Fossil Vertebrata of North America, 1902, p. 437, may be consulted.

As here employed, G/yptops will include 4 species: the type, G. plicatulus of the
Jurassic, G. celatus of the Lower Cretaceous, G. pervicax of the Benton, and
G. depressus of the uppermost Cretaceous. Possibly when more is known of the two
last-mentioned species they will be removed from the genus.

Glyptops is closely related to Pleurosternon Oxtn as already recognized by
Dr. Baur. However, it differs from the latter in having the hinder lobe of the
plastron less constricted and without posterior notch, in having the inframarginals
almost wholly on the plastral bones, in having the costo- marginal sulci well below
the costo-peripheral sutures, except over the bridges, and in having longer bridges.
The distance from a line joining the free border oF the anterior iene of che plastron
with the posterior lobe to the outer end of the mesoplastron is contained in the width
of the bridge about three times in Plewrosternon and about two times in Glyptops.

Heloc hel ys i is another relative of Glyptops. Its hinder plastral lobe is little more
than half as long as wide; the plastron appears to have been less closely joined to
the carapace than in Glyptops; the bridges are short; and the last neural, the only
one known, 1s hexagonal, with the broader end directed backward.

KrY To THE KNowN SPECIES.
7. Jurassic.
a. Morrison beds : plicatulus
4A. Cretaceous.

a. Lower Cretaceous.
b. Potomac beds : calatus
bb. Benton beds Lt ; pervicax

aa, Upper Cretaceous.
c. Denver beds? depressus

PLEUROSTERNID&. 47

Glyptops plicatulus (Cope).
Plates 5, 6; text-figs. 17-27.

Compsemys plicatulus, Cope, Proc. Amer. Philos. Soc., xvi, 1877, p. 196.—Baur, Amer. Naturalist,
XXIV, 1890, p- 534; Proc. Acad. Nat. Sci. Phila. 1891, p. 411; Anat. Anzeiger, x11, 1896, p. 565.—
Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 437.

Glyptops ornatus, Marsu, Amer. Jour. Sci. (3), XL, 1890, p. 177, pl. vii, Ags. 1, 2; Monogr. U. S.
Geol. Surv., xxv, 1897, p. 507, figs. 63, 64.

The present species is one of the two oldest known from North America, coming as it does
from the uppermost Jurassic. The other species which comes from the same deposits is
Probaéna sculpta, but it is represented by only an imperfect shell; whereas Glyptops plicatulus
is represented by nearly all portions of the skeleton.

The species had for its type various fragments that had been collected for Professor Cope
by Mr. O. W. Lucas, at Canyon City, Colorado, from freshwater deposits that were called by
Professor Marsh the Atlantosaurus beds, by Scott and Knight the Como beds, and by W hitman
Cross the Morrison beds. Cope’s type is No. 6099 of the American Museum of Natural
History. The principal parts present are one complete costal, apparently the third of the left
side (plate 5s fig. 1), the proximal end of what is regarded as the fifth of the night side, the right
axillary region, most of the left hypoplastron, and a part of the contiguous left xiphiplastron.
The supposed third costal is shorter than the corresponding one oF the American Museum
specimen, No. 336, a slightly smaller individual, as shown by the hypoplastra. It might be
regarded as the fifth were it not that the distal end is crost by the costo-marginal sulcus. The
vertebral scutes are narrower than those of No. 336. Also the bases of the rib-heads are
slenderer. The hypoplastral is somewhat longer and at the same time slightly narrower than
that of No. 336. There is a possibility that we have here two species. The sculpture appears
to be identical in the two specimens. Baur appears to have examined the type bones and he
identified them as being the same as Marsh’s Glyptops ornatus.

Professor Marsh’s types of his Glyptops ornatus were obtained at Como, Wyoming, from
deposits regarded as of the same age as those of Canyon City. The remains consisted of a
skull nearly complete, portions of two other skulls, and portions of the shells of two or three

other individuals. These were briefly described and figured by Marsh, as cited above. The
figure of the skull particularly is very poor. This ekull had been crusht laterally and hence
the figure shows it as narrower than it was in life. A side view of the same skull, prepared for
the U. S. Geological Survey, by F. Berger, is here presented (plate 5, fig. 2). In 1891 Dr.
Baur, as cited, publisht a more extended description of Marsh’s specimens and criticized some
of Marsh’s statements. The writer has examined the skull fgured by Marsh. The occipital
condyle is broken away. The length from the condyle to ihe tip of the snout was close to
62 mm. The temporal region was originally rooft over to a perpendicular plane passing
through the articulations of the quadrate for the lower jaw. The extent of this roof from the
orbits was 38 mm. The median suture may be traced from the tip of the snout to near the rear
of the skull. Most of the other sutures are invisible. The supraoccipital spine appears to have
been destroyed. The orbit is circular, with a diameter of 12 mm. The nasals are distinctly
separated from the prefrontals and have a length of 4 mm. The premaxilla are small and
distinct from each other and from the maxilla. What bone forms the septum between the orbit
and the nasal cavity can not be determined. The maxilla has a thin cutting-edge and a narrow
triturating surface. This bone extends far behind the orbit and has a length of 33mm. From
its hinder end the suture between it and the jugal may be traced upward and forward to the
border of the orbit.

On the lower side of the skull is seen the anterior end of the vomer; the remainder is
broken away. The choane were placed far forward. The palatines ran forward nearly to a
line joining the fronts of the orbits. The pterygoids are interposed between the quadrates
and the basioccipital. Where narrowest the pterygoid portion of the palate is 11 mm. wide.
The articulation of the quadrate for the lower jaw is concave in all directions, most so from
side to side.

In the American Museum of Natural History there is a specimen of this species that was
collected at Bone Cabin quarry, Wyoming, about 10 miles from Como, the locality of Marsh’s

48 FOSSIL TURTLES OF NORTH AMERICA.

specimens just mentioned. ‘The number of the specimen is 336. It presents the shell complete,
the dorsal and the cervical vertebra, the skull quite complete, the shoulder and pelvic girdles,
and portions of all the limbs. The skull will be described first.

When buried the skull was undoubtedly complete, but has suffered somewhat during
disinterment and preparation (plate 5, figs. 3, 4). The bone is extremely brittle and much
fractured. On this account, and because of the roughness of the surface, the sutures are mostly

undeterminable. The length from the occipital

a condyle to the end of the snout is 66 mm., nearly
Soe i the same as that of Marsh’s specimen. In form it

3 a is wedge-shaped, but not so narrow as Marsh’s
laterally crusht specimen. The width at the
at ro quadrates is 48 mm. The supraoccipital spine is

% a 4 missing. It is doubtful whether it ever had any
| considerable length. The parietals lack about 5

: aan mm. of extending backward as far as the occipital

; | condyle. The roofing of the temporal region is

—— =k \ like that of the skull just described. Whether or
{not the parietals join the squamosals can not be
wae | determined; they probably do. The orbits had a
a ei ae diameter of 15 mm., but some allowance must
ae 1 be made for distortion; they appear to have

4 as hee f | been larger than those of Marsh’s type. The
i ~~ /% | interorbital space measures g mm. Apparently
_ the sutures bounding the frontals laterally can be
2 distinguisht, and possibly those limiting these
/ bones anteriorly. Nasal bones can not be distin-
VE ao ‘(ae guisht. The maxillary bone is only 3 mm. wide
are fe ae ] below the orbit. The tympanic cavity appears to

De ee ey have been small. The stapedial passage was open

aS behind. The quadrates appear to have been
ae directed slightly forward. The lateral squamosal
processes extend behind the occipital condyle
about 5 mm.

On the upper surface there is observed on
each side a groove, or sulcus, which starts about 8
mm. from the midline at the hinder border of the
temporal roof, runs first forward and inward to
near the midline, then toward the orbit. Similar
sulci are seen in Chelydra and it is thus rendered
probable that the surface of the head was covered
with horny scutes.

The basioccipital and the basisphenoid are
narrow. The suture between the two can not be
certainly distinguisht. The basisphenoid can be
traced forward about 30 mm. from the condyle.
It is 7 mm. wide posteriorly and narrows ante-
riorly. It is doubtful if the pterygoids came in
contact at any point. The pterygoid region, where
narrowest, is 14 mm. wide. Toward the anterior
end of the basisphenoid there is on each side,

Fic. 17.—Glyptops plicatulus. Carapace. x4. between this bone and the pterygoid, a foramen,
No. 336 A. M. N. H. Shows the various such as is seen in Baéna, probably for the passage
bones and many of the scutes. of a vein. In the skull here described a groove

Fic. 18.—Glyptops plicatulus. Carapace. 4. proceeds backward for some distance, and the
No. 1357 Yale University. Shows only the appearance is such that the presence of a slit
bones. Figure from U.S. G. S. between the bones is suspected. The ectoptery-

PLEUROSTERNID&. 49

goid processes are very large. The anterior region of the roof of the mouth is damaged,
so that little is to be learned from it.

The lower jaw is closely prest against the remainder of the skull. From its tip to the
hinder end is 54 mm. The two rami are co-ossified. The symphysis is 10 mm. long. All the
bones are smooth.

Here it may be permitted to make some remarks on Bautr’s description of the
skull of this species. The sculpture of the bones is not exactly like that of the shell,
it being finer and more pustular. Baur, in opposition to Marsh, states that the
exoccipitals take part in the formation of the condyles. It seems probable that
Baur came to this conclusion from the presence of the pit, making the assumption
that this is found only where the basioccipital meets the exoccipital. In the skull
of a Bridger Baéna the basioccipital takes no part in the condyle, and yet there is a
very distinct pit. The skull of G/yptops in the American Museum does not enable
us to decide the question.

Portions of 7 of the cervicals are preserved in the American Museum specimen, the first
not being present. As a whole, the neck seems to have been short and slender. Its total
length did not exceed 120 mm., the carapace being 300 mm. The articular end of the second
cervical has a diameter of only 4 mm., while that of Trachemys elegans, with a carapace 230 mm.
long, has a diameter of 5 mm. All the cervicals present a deep, comprest, and sharp keel along
the lower side, thickening behind. All, excepting probably the first, possest transverse pro-
cesses, each about 4 mm. long. All have the anterior and posterior articular surfaces more or
less concave. The hinder end of the eighth is concave, without the convex portion men-
tioned by Dr. Baur. The anterior end also is concave. The postzygapophyses are close
together, but have not coalesct. The hinder end of the seventh is nearly flat, and we may
suppose that it has entered on the first stages in forming a convex articulation. Barring the
articular surfaces, these cervicals resemble closely those of Baéna.

The first dorsal vertebra has a very distinct keel along its lower side and the anterior end
of the centrum is concave. The first rib is long, about 57 mm., and has apparently lost a
portion of its extremity. It has a diameter of about 5 mm. and is applied closely to the rib of
the first costal plate. The rib-heads are much like those of Baéna. The one belonging to the
first costal plate is the broadest, about 12 mm. in diameter. Most of the others are smaller,
about 8 mm. wide. The last two are considerably smaller. The tenth rib is short and thick,
its length being 15 mm., its diameter 4 mm. Its outer end is somewhat enlarged, to support
the ilium, and it is applied against the lower surface of the eighth costal. The first sacral rib is
the larger, about 20 mm. long, and expanded at its outer end to a width of ro mm. The
second sacral rib is much slenderer. Both of them resemble corresponding parts of Chelydra
and Baéna.

The carapace (plate 6; text-fig. 17) is 300 mm. long in the midline, and 272 mm. wide. It
is much deprest, but this is due to some extent to distortion during burial, for some of the
costals and peripherals are spread apart. Anteriorly the border is slightly excavated in the
midline. Posteriorly the carapace is truncated and broadly and shallowly excavated. Marsh’s
figure represents his specimen as more rounded behind. The peripherals extended outward
nearly horizontally. Their borders are subacute near the midline in front and behind, but
they thicken and become more obtuse toward and over the

{hig eee bridges. The whole surface of the carapace and of the plastron
Neural. Length. Width. | . ; Pics : fi
| is finely sculptured with tubercles and winding ridges, there
i eee 7 | | being about 12 ridges in a line 10 mm. long.
I 33 | The nuchal bone is quadrilateral, with the broadest side
g | a | joining the first costals and the first neural. This side is 80
s 3 co a . °
4 260 | (23 mm. long. The free border is 42 mm. long. The accompanying
5 27h we Nh 23 | table presents the dimensions of the neurals.
I 1 . . . . .
; 3 Fs There is in this specimen a single suprapygal. Baur states
8 18 2K | that in the Yale specimens there are two of these bones, but

|
|
|

Marsh figures only one. A sketch in the writer’s possession,

50 FOSSIL TURTLES OF NORTH AMERICA.

made apparently for Dr. Baur, and here reproduced (fig. 18), represents the first as small and
occupying the space between the costals of the eighth pair. The suprapygal of No. 336 1 is
large. Its length is 36 mm., its width anteriorly 14 mm.; the maximum 64 mm.; the posterior
width 38 mm. This bone somewhat resembles in form that of a Testudo.

The costal plates narrow in succession backward. The peripherals are 11 in number on
each side. Anteriorly and posteriorly they are high; over the bridges they are low. The
first and second have a height of 35 mm.; the fifth, 18 mm.; the ninth, 40 mm.

Figs. 19-27. Glyptops plicatulus. No. 336 A.M.N.H.

1g. Plastron. ><4. Shows bones and many of the 23. Pelvis from below. >%#%. Somewhat crusht
scute areas. fore and aft.

zo. Scapula. 3. Procoracoid process, on the 24. Pelvis from left side. > 3.
right, shortened by crushing. 25. Right femur. > 3. From tibial border.

21. Coracoid and procoracoid process of scap- 26. Right femur. z. From dorsal surface; some-
ula. x3. what crusht.

22. Right humerus. 4%. Dorsal surface. 27. Digital bones. 1.

The plastron is flat (fg. 19). Its length is 260 mm. The anterior lobe is 80 mm. long;
its width at the base, 122 mm. The edges are thick and rounded. The bones at the epihyo-
plastral suture are 8 mm. thick. The entoplastron is 43 mm. long and 47 mm. wide and
broadly rounded behind. The hyoplastrals meet at the midline about 50 mm. The meso-
plastra differ in width at the midline, the left being 30 mm. wide, the right 22 mm. The
hinder lobe is 78 mm. long and 106 mm. wide at the base. The hinder border is truncated.
The tree Bede are acute- edged. The bone thickens rapidly from the borders to about 10 mm.

The plastral bones are joined to the bridge peripherals by the usual rough sutures. Strong
buttresses rise to the costals.

The sulci bounding the epidermal scutes are extremely obscure and in many places can
not be determined. Where they can be observed they have been represented in the diagram-
matic figures. Those of the plastron are less difficult of observation. The gular scutes are
very broad, the sulci bounding them posteriorly curving outward and backward to near the
epihyoplastral suture. The intergulars can not be made out on No. 336, but they are shown
by Baur in a figure furnisht for him by the United States Geological Survey (plate 5, fig. 5)-

PLEUROSTERNID&. 51

These intergulars slightly overlap the entoplastron. The humero-pectoral sulcus passes
behind the entoplastron. Dr. Baur’s figure of the median sulcus represents it as running an
exceedingly irregular course. In fig. 19 this sulcus is probably represented much too straight.
On the bridges are very distinct inframarginals, as represented in fig. 19. Only the angles
of these extend over on the peripheral bones.

Dr. Baur states that a nuchal scute is present in this species, but in No. 336 it can not
be distinguisht with certainty. On most of the peripherals the sulci may be seen, both on
the upper and the lower sides. The boundaries of the three anterior vertebrals have been
determined quite satisfactorily. The width of these scutes is about 90 mm.

Dr. Baur has briefly described the shoulder-girdle. This is present in specimen No. 336
(figs. 20, 21) altho the distal portions of the coracoids are damaged so that their exact form
can not be determined. The left half of the girdle is least injured and distorted. Here we
find the scapula, the procoracoid process, and the coracoid standing at nearly right angles with
one another. In this respect they are much as in Chelydra. The scapula is relatively shorter
than in Chelydra, and the procoracoid is shorter still. “The lower end of the scapula is strongly
comprest. The glenoid fossa is removed outward some distance from the perpendicular
portion of the scapula. This fossa presents some interesting peculiarities. It measures 7 mm.
by 9 mm. and it has the long axis directed nearly horizontally. The fossa of Chelydra, nearly
of the same shape, is directed nearly perpendicularly. Furthermore, there is, running along
near the lower border of the fossa, a prominent ridge, which is found to correspond to a groove
on the head of the humerus. Nothing of the kind is found in either Chelydra or Testudo,
except in the most rudimentary form. However, in a specimen of Trachemys rugosa there are
found similar structures; but here too, the long axis of the fossa is directed strongly upward.
Examination of the naturally articulated parts of Trachemys shows that the motion of the
humerus is nearly confined to a plane which is directed backward and downward. The
motion of the humerus of a TJ estudo, with its round head, is much more free and varied. The
T estudo is a tortoise adapted solely for walking; the Trachemys is to a great extent a swimmer.

Dr. Baur states that the fore limb of Compsemys (Glyptops) is long and resembles the
elements of the Emydidae. However, the humerus (fig. 22) is a little shorter proportionally
than in Trachemys rugosa and the limb is rather feeble. The humerus is but little more than
one-half as long proportionally as that of Chelydra. The bone is, however, not so slender
as that of Trachemys, but has more of the form and proportions of Chelydra. This applies
also to the size of the radial and ulnar tuberosities. The distal end of the humerus has points
of interest. Its breadth is like that of Chelydra. There is distinct evidence of the presence
of a deep coronoid depression. The ectepicondylar foramen pierces the bone at a distance
of 11 mm. above the condyle. The trochlear surface reminds one of that of some mammal.
Instead of forming an elongated smooth surface, convex in both directions, it presents two
prominent ridges separated by a groove. ‘The distal end of the humerus of Trachemys rugosa
presents a somewhat similar structure, but the guiding ridges are far less prominent. As in
Glyptops, the most prominent one is that for the head of the radius. The result of these
arrangements must be that the motion of the forearm of both genera is confined to one plane,
like that of the forearm of a man.

There is this difference, however, between the humeri of Trachemys and Glyptops. In
the former these ridges run nearly parallel with a plane passing through the long axis of the
head of the humerus. The effect of this is to make the forearm move in the same plane as
the upper arm; that is, downward and backward. In Glyptops, on the other hand, the ridges
of the trochlear surface are directed at an angle of about 45° with the plane of the head of the
humerus. Hence, when the limb is drawn backward, the humerus moves in a horizontal
plane, while the forearm, if flext, would move downward and backward.

One ulna is present. It is slightly longer proportionally to the humerus than it is in
Trachemys, and its distal end is broader. Of the hand the writer can say nothing.

Baur has dealt with the pelvis without figuring it. He errs with regard to the inner ramus
of the pubis, when he says it is a slender element and that the ischium is larger than the pubis.
The contrary is true (figs. 23, 24). The pubis, aside from the lateral processes, does not differ
greatly from that of Chelydra or Testudo. In the specimen before me it has an antero-posterior
extent of at least 25 mm. It is quite deeply notcht in front. Baur is possibly, but not certainly

52 FOSSIL TURTLES OF NORTH AMERICA

correct when he states that it did not come in contact in the midline with the ischium. The
pelvis in the specimen here described has probably suffered some antero-posterior crushing,
but the pubes and ilia do join. In Baéna, whose pelvis is identical with that of Glyptops,
there is, at least in aged individuals, a union of these elements in the midline.

The lateral pubic | processes are quite different from those of Chelydra, being more massive.
At their extremities, where they come into contact with the xiphiplastra, they are enlarged and
rough. Above this they are constricted into a sort of neck. The ischium is narrow from front
to Feels about 12 mm., and thin, as in Baéna. Its hinder lower border is nearly straight until
the processes are reacht on which the ischium rests on the plastron. These processes stand
at a distance of 30 mm. apart. Each is terete, pointed at its free end, and about 15 mm. long.
They are directed backward.

The ilium is not greatly different from that of Chelydra, except that it is shorter and
proportionately stouter. The sacrum is in general smaller and weaker than that of Chelydra,
except that the distance of the acetabula apart is the same. The pelvis is essentially like that
of Baéna and all parts should be compared with those of the latter genus.

The only portion of the hind limb present is the right femur and probably some foot bones.
Dr. Baur states that the femur agrees with that of the Emydidz. In length, it is exactly that
of the Trachemys mentioned and relativ ely much shorter than that of Chelydra. It is much
curved, especially toward the distal end (figs. 25, 26). The greater trochanter is separated
from the lesser by a deep fossa. From che? greater trochanter a prominent crest runs down
on the hinder side of the femur one-third or more of its length. The distal end of the femur is
damaged, but it presents indications of having had the condyles more prominently developt
than in turtles in general. The total length of the femur in a straight line is 61 mm.

One complete toe, which probably belonged to a hind foot, is preserved with the parts in
place (fg. 27). It shows a metatarsal and three phalanges, and these have a total length of 42
mm. The metatarsal is slender and has a length of 22 mm.

> ‘ oe f ae
~~ iy Ne s _
G4 ASS
ert wae
ee —~J
=
in ae eee)
ig eae Oy ee |
ESA Pita a 31.
y Ft po <
SS fii ee 30°
Figs. 28—- Glyptops celatus. Type specimen in U. S. N. M.
28. Portions of first and second peripherals and 30. Section across hinder peripheral.
first costal. 4. 31. Proximal end of costal bone, showing scute
2g. Section across second peripheral. 3. areas and sculpture. 3.
’ Glyptops czlatus sp. nov.

Plate 7, figs. 1, 2; text-figs. 28-31.

The fragments of tortoise to which this name is given were collected by Mr. J. B. Hatcher,
in 1887, at Muirkirk, Maryland, in deposits belonging to the Potomac formation of the Lower
Cretaceous. The fragments consist of portions of "eostals and of peripherals. The most
important fragment consists of the right first costal, a part of the first and most of the second
peripherals. ‘There is also a part of a costal situated further back in the carapace. These
bear the number 1930, and belonged doubtless to one individual. There is present also a
hinder peripheral and a first right peripheral which have the number 1939. There are also
two fragments of costals of a young individual, one of which shows the rib-head. The bones
bearing - the number 1930 are regarded as being the type of this species. All the specimens
are in the United States Nacional Museum.

PLEUROSTERNIDZ. 53

The first costal (plate 7, fig. 1; text-fg. 28) has a length, from its union with the neural
to the pointed distal end, of 103 mm. and a width, fore and aft, of 50 mm. The thickness of
the costal at the posterior border is about 5 mm. ‘The anterior half of the bone is thickened
to as much as 18 mm. to forma shoulder for the reception of the axillary buttress of the plastron.
The latter must have been considerably more strongly developt than in Glyptops plicatulus.
The head of the rib is stout. The first rib lies in front of and against the rib of the first costal
plate. The first peripheral lacks its anterior half so that its antero-posterior extent can not be
accurately determined. However, the missing portion is partly supplied by No. 1939. The
anterior, or free, border is obtuse. At one end is the sutural surface for union with the nuchal
bone. It appears quite unlikely that there was any considerable excavation in the front of the
carapace for the neck of the animal. The first peripheral of No. 1930 was 30 mm. wide,
parallel with the edge of the shell. The second peripheral has a fore-and-aft extent of 40 mm.
and the width along the free border is the same. This border also is obtuse (fg. 29) and at a
short distance from the edge the thickness is about 8 mm. It resembles very closely the
corresponding one in G. plicatulus.

The posterior peripheral, probably the tenth of the right side, numbered 1939, 1s 39 mm.
wide from the free border to the union with the costal, and 35 mm. along the free border.
Its thickness, where it joined the costal, is 10 mm., and it has come down to an acute free
edge (fg. 30). Its form is therefore that of a thin wedge.

The fragment of costal numbered 1930 (plate 7, fig. 2; text-fig. 31) shows neither the
length nor the breadth. The piece is 35 mm. wide and has an epidermal sulcus running
parallel with the sutural border and 27 mm. distant from it. The costal was therefore of
considerable total width. Its thickness is only 5 mm. “The true rib does not appear on the
lower surface, as it does in G. plicatulus.

The sulci of this species are narrow and shallow, but quite distinct. Apparently the
epidermal scutes resembled those of G. plrcatulus, altho neither the vertebrals nor the marginals
were so broad as in the latter species.

The sculpture of the surface is quite different from that of G. plicatulus. In the latter it
has a more granular appearance and is produced by distinct raised dots and by short ridges
formed of coalesct dots. In G. celatus the dots are larger, the ridges also broader, longer, and
smoother. The spaces between the elevations are as wide as the latter. In the centers of the
bony surfaces the ridges are irregular in length and direction, and often vermiculate. Border-
ing the sutural edge is a broad Bandi in mice the ridges and grooves run at right angles with
the suture. On aye costals this band may be as Tahch as 13 mm. wide.

Glyptops? belviderensis (Cragin).
Plate 7, figs. 4, 5.

Plesiochelys belviderensis, CRAGIN, Colorado Coll. Studies, v, 1894, p- 71, pl. 1, figs. 1-8.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 439-

The present writer has not seen the type specimens of this species. They belong to Colo-
rado College, Colorado Springs, Colorado. ‘They consist of two first costals, fragments of other
costals, a eal bone and a dorsal vertebral centrum. These bones were feuinid’d in the Kiowa
shales, a portion of the Comanche series and near the top of the Lower Cretaceous. The
locality is near Belvidere, Kiowa County, Kansas.

Dr. Cragin referred these bones to the genus Plesiochelys, but there appears to be no special
reason for this assignment. The species of this genus, so far as certainly known, belong to the
Jurassic, Kimeridge, and Wealden of Europe. “i he sculpture of the costals of Cragin’s species
suggests Glyptops Valahas and accordingly the species is referred with doubt to Glyptops. Two
of Cragin’s figures are here reproduced. Fig. 5, plate 7, represents a neural seen from the
under ede It is relatively considerably ioader than theneuralsof Plestochel ys (Zittel’s Hand-
buch Palzontologie, p. 545, fig. 502; Lydekker’s Cat. Foss. Rept., pt. 11, fg. 44). The front
costals figured by Cragin are narrow, the width being 38 mm., the length $2 mm. The longest
costal was III mm. long. The upper surface of fhe. shell is said to Re ornamented with deli-
cate vermicular grooving and pitting. Fig. 4, plate 7, is intended to represent this sculpture
of the costals.

54 FOSSIL TURTLES OF NORTH AMERICA.

Glyptops pervicax sp. nov.

Text-fig. 32.

The type of the present species is No. 1018 of the American Museum of Natural History.
It was collected by Mr. Barnum Brown, in 1902, from near the base of the Graneros shales of
the Benton deposits, i in Yellowstone County, Montana. These shales are of marine origin.
The locality more exactly described is on Brush Creek, to miles east of Pryor, in the county
named. The remains consist of the front and the dorsal region of the carapace and the greater
part of the plastron. The shell is that of an aged individual. Not a trace appears of the sutures,
so that the structures can not be in all respects accurately determined.

The carapace had a length of about 375 mm. There was apparently a broad, low, rounded
ridge running along the back in the areas of the second, third and fourth vertebral scutes.
At the midline of the front, over the neck, there was a rounded excavation. The anterior free
border was obtuse and about 10 mm. thick. The sulci are obscure, due mostly to an adhering
incrustation of clay, but some of them can be traced. Portions of
the second, third and fourth vertebral scutes may be mapt out.

( They were considerably broader than long. The third was 83 mm.
Rt a long and had a maximum width of 130 mm.

On the visceral surface of the carapace may be seen the bases
of the rib-heads. These were not so strongly developt as in G.
plicatulus. In the latter, as shown in No. 336, A. M. N. H., the

_~— rib-heads have a dinmerer of 10 mm., while in G. eroene the

NS diameter is about 7 mm. in a larger caividuall The whole series

| is shown, on one side at least. The extremity of the tenth rib

} | was co-ossified with the eighth costal about 10 mm. behind the

K z if rib-head of the costal named. On the first costal plate there is a

fr Nay prominent ridge which ran from the first and second vertebral

‘ } / centra to the border of the third peripheral and met the buttress

ros) Y of the plastron. At the peripheral this ridge has a width of about

; ri 18 mm. and a thickness of 11 mm. How high the buttress

Fic. 32.—Glyptops pervicax. ascended can not be determined, for the suture is obliterated.

Plastron of type. X 6+ Jr appears that the buttresses and the costal ridges meeting them
Shows scute areas. No. ; : 3 aera re

tor8 A. M_N. H. were more strongly developt in this species than in G, plicatulus.

The total length of the plastron. (fig. 32) was very close to

335 mm. The anterior lobe is broadly rounded in front, as it is in G. plicatulus. Its length

is 85 mm., its width about 150 mm. The free border is obtuse. The bone is about 10 mm.

thick. The limits of the entoplastron can not be determined. On the upper surface of this

lobe, about 18 mm. behind the anterior border, there are two low processes, one on each side

of the midline, which were probably for ligamentous attachment of the procoracoid pro-

cesses of the scapula. In G. plrcatulus the corresponding processes are about 34 mm. from

the border.

The bridge has a width of 140 mm. Its inner end starts from a low ridge which runs from
the free border of the anterior lobe to that of the posterior. The outer ends of the bridges are
mostly missing.

The length of the posterior lobe was approximately 110 mm.; the width at the base, 142mm.
The free horien are acute on a level with the lower surface. From this edge the bone is beveled
and rises to a thickness of 12mm. Beyond this, toward the midline, the thickness diminishes
again. At the hinder end of the lobe the thickness is only 5 mm. Most of the hinder
extremity of the lobe is missing. A small fragment is present, but on account of some doubts
it has not been used in the figure. On the upper surface of the lobe, very close to its border,
there is a circular depression about 7 mm. in diameter, which received a process of the ischium.
On the same surface about 60 mm. behind the inguinal notch, begins another depression, con-
siderably larger, for the reception of the pubis.

Most of the plastral scutal areas can be mapt out. The intergulars measured 32 mm.
along the midline. Taken together, they had a width of about 28 mm. a can not be determined
certainly whether or not they’ were divided at the midline. The gulars, as in G. plicatulus, had

PLEUROSTERNID&. 55

been crowded out of contact with each other. The humerals measured 47 mm. at the midline;
the pectorals, 63 mm.; the abdominals, 54 mm.; the femorals, about 78 mm. There were
doubtless inframarginals on the bridges, but the sulci are obscure.

Since the preceding description was written a second specimen has been made available
for study. This was collected by Mr. Barnum Brown, in 1904, in the Crow Reservation,
Montana, at a point about 50 miles southeast from Billings and about 25 miles east of Pryor.
The catalog number of the specimen in the American Museum is 6071. It furnishes more of
the shell than does the type, but unfortunately the plastron is fractured and faulted obliquely
to its length and the carapace is fractured and faulted in several directions.

The carapace was about 325 mm. long and the width is close to the same. The anterior
border is preserved on each side to behind the axillary notches; it is obtuse and about 10 mm.
thick. The surface presents the same kind of sculpture as the plastron, consisting of low wind-
ing ridges. The sulci are rather obscure, but the vertebral scutes were broad, as in the type,
while the right third costal is seen to have been only 70 mm. high.

The length of the plastron appears to have been close to 295 mm. The bridge is 125 mm.
wide. From the line joining the free borders of the anterior and posterior lobes of the plastron
the bridge rose to the free border of the carapace, a distance of about 110 mm. The hinder
lobe has a width of 125 mm. and a width of 110 mm. at its base. At the ends of the femoro-anal
sulci the width is 83 mm. The hinder border confirms the accuracy of fig. 32. On the bridges
are some indications of inframarginal scutes, too obscure to be traced.

Figs. 33 and 34. Glyptops depressus. Specimen in U.S. N. M.

33- Carapace of type. 3.
34. Portion of plastron of type. 4. ax.b, axillary buttress; ent, entroplastron; epi, epiplastron; hyo,

hyoplastron; hypo, hypoplastron; ing. b, inguinal buttress; mes, mesoplastron.

Glyptops depressus sp. nov.

Text-figs. 33, 34-

The type of this species belongs to the United States National Museum. It appears to
have been secured by one of Professor O. C. Marsh’s collectors in 188g, inasmuch as it bears
his packing number “1998. Box 3.” With the specimen comes a statement by Mr. Whitman
Cross, of the United States Geological Survey as follows:

“*No. 2 Box B. ’89,’ (Cannon’s designation). An isolated fragment. (I think this fossil is
from the Denver beds, from the nature of the sandstones between the shells and the apparently
zeolitic material in cells of the bone.)”

Professor Marsh has recorded Compsemys plicatula from the Denver beds, but whether on
the evidence of this specimen can not be determined. The probabilities that the same species
is found from the top of the Jurassic to the top of the Cretaceous are remote. ;

The specimen presents considerable portions of the carapace and of the plastron. The

56 FOSSIL TURTLES OF NORTH AMERICA.

hinder end of the carapace has, at the time of burial, been crusht down to the plastron. After
having been weathered out of the matrix the specimen suffered further damage, all that part
behind the seventh neural having been destroyed. All the peripherals are likewise missing.

The length of the carapace (fig. 33) was originally about 120 mm.; the width was about
110mm. The shell is deprest and was so probably during life. The surface of the carapace
presents indistinct evidences of having been sculptured finely as in G. plic atulus, or possibly
more like Compsemys victa. The anterior border of the nuchal bone is eroded away. The
width of the bone was close to 38 mm. Its form is quite different from that of G. plicatulus.
In the latter the postero-lateral onder are nearly parallel with each other, while in the present
species they make nearly a right angle. The accompanying table presents the dimensions
of the neurals present.

The great relative width of these neurals as compared with those of G. plicatulus is striking.

The proximal end of the first costal is 14 mm. wide, while
the width at the middle of the length is 26 mm. In G. plicatulus
the median width is little more than the proximal. The succeed-
= iz ing costals, at the middle of the length, measure as follows:

Neural. Length. Width.

I 12 | 9 The second, 14 mm., the third, 14 mm., the fourth, 12 mm.,
: = 13 the fifth, 11.5 mm., the sixth, 19 mm. The third expands
P

3 12 14

eat i 14 distally to nearly 20 mm. whe width of the sixth is relatively
2 ue lees much greater than that of G. plicatulus, but it corresponds to

I 1

7 | a matt the ee length of the sixth neural.

The anterior lobe of the plastron appears to have been
rounded like that of G. plicatulus. The epiplastra are badly
eroded, but the width of each is 13 mm. The entoplastron is 22 mm. long and 26 mm. wide.
The antero-lateral borders come together to form an obtuse angle; the hinder end of the
bone is more pointed. The mesoplastra are relatively broader fore and aft than those of G.
plicatulus. That of the right side is about 15 mm. wide at the midline; but it expands later-
ally, so that at the middle of its length the width is 24 mm. ‘That of the left side is 23 mm.
wide at the midline, but narrows laterally for a short distance. The remainder is missing. It is
remarkable how close the hinder border of the mesoplastron comes to the inguinal buttress,
differing in this respect much from G. plicatulus.

There are evidences of rather strong axillary and inguinal buttresses. They appear to
have articulated with the distal ends of the fifth and sixth costals, at their junctions.

On account of the weathering to which this shell has been exposed, the boundaries of the
scutes can not be determined.

Family BAENIDZ Cope.

Amphichelydia having the plastron firmly joined to the carapace by sutural union with the
lateral peripherals and with the costals by strongly developt axillary and inguinal buttresses.
Mesoplastra usually meeting at the midline and | expanding toward the outerends. Skulls, so
far as known, broad and ce Temporal roof extensive. Neck short, most of the vertebral
centra with only one end concave.

To this family are assigned provisionally the genera Polythorax Cope and Archeochelys
Lydekker. The former possest intergular and interhumeral scutes; the latter genus appears to
have had a complete series of median plastral scutes.

The Baénide are closely related to the Pleurosternide, but the great advances made in the
structure of the cervical vertebra and the extension of the plastral buttresses seem to set the
species off as a distinct family.

According to our present knowledge this family had an existence extending from the
Upper Jurassic to the Upper Eocene. Probaéna, a close relative of Platychelys, of the Upper
Jurassic of Europe, has been described from the Como, or Morrison beds, occurring there with
Gly ptops. Species belonging to Baéna are now known from the Judith River beds, the Lara-
mie, and from all the diasous of the Eocene to the Uinta. Boremys Lambe comes from the
Judith River deposits, Eubaéna trom the Laramie, and Chisternon from the Bridger.

Baéna appears to be the genus most prolific of species and in most respects the one most
advanct. The carapace possesses a series of 8 neurals and a corresponding number of costals,

BAENIDZ. 57

a nuchal, 12 pairs of peripherals, and what must be regarded as a suprapygal, but no true
pygal. The plastron has, besides the bones found in the Emydida, a pair of mesoplastrals,
which usually reacht the midline and expanded greatly outward to join the fifth and sixth
peripherals. The axillary and inguinal buttresses are high and wide. Between the axillary and
the inguinal of each side there is a large sternal chamber. The axillary buttress ascended to
a point a little above the lower border of the first costal, meeting there the comprest rib of
the first dorsal vertebra. ‘The inguinal buttress rose above the lower border of the fifth and
sixth costals and was articulated in a ridge rising trom the adjacent borders of these costals.

The scutes of certain regions of the shell are extremely variable; in other regions they vary
little. On the carapace it 1s ee area occupied in the Emy didzx by the first renenral: the nuchal,
and the first pair of costals that is subject to variation in its scutes. There may be on each side
a supernumerary first costal scute, or it may occur on only one side, or it may be wholly absent.
In some specimens is a second pair of supernumerary costals, lying just behind the nuchals.
There may even be a supernumerary vertebral cut off from the front of the normal first
vertebral.

On the plastron the gulars and intergulars are variable in form and size. The infra-
marginals vary in number and size and form. There are usually 4, but often the second from
the axillary notch is missing on one or both sides. In this case the pectoral scute may or may
not reach the marginals.

In Chisternon there intervenes between the nuchal bone and the first neural a large bone
that is not present in Baéna (fig. 76). This the writer calls the preneural. In this genus too the
occasional variations in the scutes of the front of the carapace appear to be quite the rule. The
normal first vertebral scute is transversely divided, so that there are 6 vertebrals. ‘There is
usually on each side a supernumerary costal and sometimes two of them, making 6 pairs of
these. The same variations occur in the scutes of the plastron of this genus that we find in
Baéna. In one case there are 5 inframarginals.

It would be worth much to know the meaning of these variations in the bones and scutes.
Is the presence of the preneural in Chisternona primitive or a secondary condition? The writer
does not regard it as probable that a bone like the nuchal has become secondarily divided, or
that a new bone has become developt in that region. It appears more probable that both it and
the nuchal are continuations forward of the row of neural bones, and that in the most
advanct turtles the preneural has been crowded out of existence by the growth of the nuchal.
It is evidence in favor of this view that in Boremys Lambe there is present a small preneural;
also that it is present in the trionychoid genera Aspideretes and Plastomenus. “These genera
have probably inherited this bone from their Amphichelydian ancestors.

As regards the supernumerary scutes, we have the same questions to answer as in the case
of the prenuchal. Do we have here a breaking up of the normal scutes into smaller areas, as has
been observed in some modern genera by H. Gadow, W. P. Hay, and R.E. Coker; ordo we have
the normal number of scutes that were present in the earlier turtles, together with a tendency
to a suppression of some of them? We must recognize the fact that on most parts of the shell
the scutes are as stable as in ordinary turtles; aio, especially on the plastron, there is a ten-
dency for the sulci to wander somewhat wildly. It is to be noted that the variations occur in
those regions where, in modern turtles, certain scutes have been supprest. There can be no
doubt that intergulars were primitively a possession of all turtles, but in most Cryptodira they
have been supprest. The primitive turtles likewise possest on each bridge a complete row of
inframarginals; but in most living genera these have been eliminated, with usually the excep-
tion of an axillary and an inguinal scute. There is probably not so much evidence that one or
more anterior costal scutes hay e been supprest. In H. von Meyer’s representation of Acichelys
crassipes (his Paleomedusa testa, Lithogr. Schiefer, pl. xx, fig. 1) there is shown a pair of super-
numerary costal scutes. It is Also interesting to observe in that specimen 2 neurals between the
first pair of costal bones. The anterior of these is probably the preneural. In the modern
genus Caretta there are 5 pairs of costal scutes. It appears probable that the preneural and
the supernumerary anterior vertebral scute tended to disappear together.

The skull of the Baénide presents various primitive features. ‘The presence of distinct
nasals, of lacrimals, and a wide temporal roof is to be cited. The writer has not found
epipterygoids. The short supraoccipital is likewise primitive. When we leave aside these

58 FOSSIL TURTLES OF NORTH AMERICA.

characters the skull appears to be cryptodiran in structure. The neck must be regarded as
primitive and intermediate between the Cryptodira and the Pleurodira. No features strictly
pleurodiran appear.

The cervical vertebra are described under the species Baéna riparia and Chisternon
hebraicum. Considering the shortness of the neck, the structure of the vertebra, and the nar-
rowness of the anterior border of the carapace, it seems probable that these turtles were able to
find in the shell little protection for their heads.

The tail was long, resembling that of Chelydra. With two or three of the skeletons there
have been found some conical bones, the bases of which were buried in the skin. Some of
these are symmetrical and it appears probable that they were placed in a row on the upper
midline of the tail, as in Chelydra. Others of these bones are unsymmetrical, and possibly
formed parts of lateral rows on the tail. If there had been an armor of dermal bones on the
legs it would probably have been observed in some of the specimens.

For the shoulder-girdle and the pelvis the reader is referred to succeeding descriptions of
Baéna and Chisternon. ‘The limbs are of the walking type.

The following key may be of some use in determining the genera of the family:

A. No interhumeral scute.
a. A preneural present.
bs. No supramarginallscutes: 45 202...0 saan otis os sem Sets ed antes ee rete tee Chisternon
bb. Supramarginals: presents: 22. <.isee vieic.cis. the ote sialon a sree ies te osate susapererns oe oath oe Boremys
aa. No preneural so far as known.
c. Plastron projecting little, if at all, beyond front of carapace.

d. Skull with¢choanze*welllin*fronts..c..- ees. eee eee eee Baéna
dd. Skull with choanz between orbits..................2..0.00005 .... Eubaéna
ddd. Skull unknown. Plastron with median fontanel.................... Probaéna
cc. Front of plastron projecting in front of the excavated carapace.
e. The axillary and inguinal buttresses not greatly developt...... Thescelus
ee. Axillary buttresses rising high on first costals............... .. Charttemys
aaa. Characters not well known. A UBT RIES present; the vertebral scutes broad; 9 pairs
ofscostal ssn type 082 Adon. gn sseelege Sanus & ered orsen se Ayes Clie temeens sae ota skas Neurankylus
AA. Plastron with an interhumeral scute.
a» Outer surkacerot plastron nl Oseis seer acne apse ee eee tere teen Polythorax
. Outer surface of plastron with globular cleyationSa.. amet ae OR eerie Naomichel ys

Genus PROBAENA Hay.

A genus closely related to Baéna, but with a more deprest carapace, the hinder border of
which is little or not at all notcht. Vertebral scutes broader than the costal scutes. Plastron
with its hinder lobe rounded. A fontanel (permanent?) between inner ends of mesoplastra.

It is not improbable that when the skull and the cervical vertebra of this genus shall be
discovered, it will prove that it belongs to the Pleurosternide and that the Baénidz had not yet
diverged from the former family.

Probaéna sculpta Hay.

Plate 7, fig. 5.
Probaéna sculpta, Hay, Ann. Carnegie Museum, 11, 1903, p. 201, plate iii, figs. I, 2.

The type is a small and somewhat imperfect turtle, represented by about three-fourths of
the carapace and the greater portion of the plastron.

It belongs to the Carnegie Museum, Pittsburg, and was collected by Prof. J. B. Hatcher,
in 1g0f, in the “‘ Marsh quarry” in the lower portion of the Morrison, or Atlantosaurus beds,
8 miles north of Canyon City, Colorado, The catalog number is 917.

The length of the carapace is at present 105 mm., very near the original length; the
width is 70 mm. The shell has apparently been rather flat, but probably somewhat less so in
life than at present. The greatest distance between the upper and the lower surfaces is now 27
mm. The borders of the carapace behind the inguinal notches are considerably flared upward,
but this may be due somewhat to post-mortem distortion. This border appears to have been

BAENID&. 59

little or not at all notcht, except in the midline behind, where there is a slight excavation.
In the nearly smooth hinder border this genus differs from the species of Baéna.

Most of the sutures and of the epidermal sulci are obscure; and in most parts of the cara-
pace the sutures are incapable of determination. The sulci bounding the second, third, and
fourth vertebral scutes are satisfactorily seen. These scutes were very broad, each about 34
mm.; while the costal scutes were only about half as wide. The areas occupied by the median
scutes are conspicuously sculptured. The sculpture, as shown by the third scutal area, con-
sists of ten or twelve prominent, sharp, uneven ridges, which radiate forward and outward
from the middle of the hinder border of the area. Evidently a somewhat similar, but less bold,
sculpture characterized the areas of the costal scutes; but these surfaces have been injured so
that it can not be described. There is no evidence of the presence of supramarginal scutes.

On the left side the costal and marginal plates are broken away. The anterior and
posterior buttresses of the plastron are thus revealed; and it is evident that the anterior one,
joining the second costal plate, projected inward a considerable distance, as in Baéna, to form
the anterior boundary of a lateral chamber, whose posterior boundary was formed by the
hinder buttress joining probably the sixth costal plate.

When the costal plates broke away, the extremities of the third, fourth, and fifth ribs were
left adhering in the matrix. These evidently past downward deeply against the inner sides of
the corresponding marginal plates, as in Chelydra. Such was probably not the condition in
Baéna. The ends of the ribs are terete, not flat as in most other cases. So far as can be deter-
mined, there were no fontanels between the costal plates and the marginals.

Of the plastron (plate 7, fig. 5) all is present except the epiplastrals, and possibly the
anterior part of the entoplastron. ‘The plastron resembles closely that of Baéna; but the hinder
lobe is not notcht posteriorly, but rounded. There is a considerable fontanel between the inner
ends of the mesoplastra. This may be due to the immaturity of the specimen; but judging
from the closeness of all the sutures of our specimen, and from the fact that in Baéna the bones
soon co-ossify, it seems probable that the fontanel would persist till a late period of life.

The anterior as well as the posterior lobe has a width at the base of 36 mm. The posterior
has a length of 30 mm., and the anterior was probably about as long. The posterior lobe
diminishes in width rather rapidly backward. The entoplastron was unusually long and narrow
in its hinder portion. Nothing can be determined regarding the intergular and gular scutes.
The mesoplastron is narrowed at the inner end, as in some species of Baéna. Each is
traverst by the pectoro-abdominal sulcus.

The bridge is 30 mm. wide, fore and aft. The inframarginal scutes which covered the
bridge can not be mapt with certainty, but there can be little doubt that they were present and
much like those of Baéna.

P. sculpta may be regarded as a form ancestral to the later numerous species of Baéna
which have been found in Belly River, Upper Laramie, Puerco, Bridger and Uinta beds. Dr.
Baur regarded Glyptops plicatulus as the forerunner of Baéna (Proc. Acad. Nat. Sci. Phila.
1891, p. 421); but we now find in the same quarry from which G. plicatulus has been reported
a form much nearer to Baéna than is Glyptops. It becomes evident that we must go back much
further to find the common ancestor of Glyptops and Probaéna.

Platychelys, of the Upper Jurassic of Solothurn, Switzerland, is closely related to Baéna
and Probaéna, and has been assigned by Lydekker to the Pleurosternide. It differs in having
a more highly sculptured carapace, supramarginal scutes, and mesoplastrals which do not

reach to the midline. .
Genus BAENA Leidy.

Shell firmly joined to the carapace by sutural union with the lateral peripherals and by
broad and high axillary and inguinal buttresses. Hinder border of the carapace scallopt, and
with an extensive excavation over the tail. Nuchal bone in contact with the first neural; no
preneural; no supramarginal scutes; anterior lobe of plastron not extended in front of the
carapace. Mesoplastra large, with the outer ends expanded. Posterior plastral lobe slightly
emarginated. Intergulars, gulars, and inframarginals present. Skull broad, with the temporal
region extensively rooft, the squamosals in contact with the parietals. Jugal forming a part of

60 FOSSIL TURTLES OF NORTH AMERICA.

the rim of the orbit. Triturating surface of the maxilla furnisht with a prominent longitudinal
ridge. Choanz opening on a line joining the fronts of the orbits.

Key to Species oF BAENA.
A". Judith River species.
1. Length of anterior lobe 0.60, its width 0.82, of width of bridge; width of hinder lobe
0.94 of width of bridge; entoplastron longer than broad ....................... callosa
2. Plastron known only from part of anterior lobe; the entoplastron broader than long . . antiqua
A*. Laramie species.
1. Length of anterior lobe 0.92, its width 1.00, of width of bridge; width of hinder lobe
1.04, Of width of brid gee. eens: aes rater ate eae hatchert
2. Length of anterior lobe 0. 58, its length 0.79, of width of bridge; width hinder lobe 0.75

of width oftbridpe’....s..s50c eae cence ee ee eee ee eee eee eerie marsht

Av.) Torrejon species mo caa: coe care een ene Cee escavada
A‘. Bridger species.

1. Shell broad behind and deeply scallopt; strongly sculptured on back................ arenosa

2. Not so strongly sculptured; a broad groove) alonp» the ibackvy «24-11 eres oie riparta

3- Shell oval, thin; the sculpture broken up into wrinkles; no median groove .......... sima

4. Shell oval; rounded behind; néanly,4smoothis- nt osc beee abe eee tel eee clara

AP Unita speciestanciy: iy. Abteeity eR AE EA OT Ce Eee emilia

Baéna callosa Hay.
Plate 8, fig. 1; text-figs. 35, 36.
Baéna callosa, Hay, Ann. Carnegie Museum, 11, 1904, p. 178, plate ix, text-figs. I, 2.
This species is based on an incomplete shell which belongs to the Carnegie Museum, in
Pittsburg, Pennsylvania. The number is 330. It was collected in the year 1903, by Mr. J. B.
Hatcher, in the Judith River beds of Willow Creek, Gallatin County, Montana.

The posterior fourth of the carapace is missing; and of the anterior three-fourths, many of
the peripherals and portions of the costals are wanting (text-fig. 35). The entire length of the

a) yoo. Son “

Figs. 35 and 36. Baéna callosa. Type. X#.

35- Carapace. c.s. 1, c.s. 2, etc., costal scutes; v.s. 1, v.s. 2, etc., vertebral scutes.

36. Plastron. ab, abdominal scute; am, anal scute; ent, entoplastron; epi, epiplastron; fem, femoral scute; g, gular

; scute; hum, humeral scute; hyo, hyoplastron; hypo, hypoplastron; fg, intergular scute; mes, mesoplastron;
pec, pectoral scute; xiph, xiphiplastron.

BAENID&. 61

shell was about 250 mm.; the width something over 200 mm. ‘The sutures between the various
bones are not obliterated, but the preservation is such that they can not be satisfactorily traced.
Most of the anterior border of the nuchal is broken away. ‘The thickness at the free border
is 6 mm.; and this border was rounded in section. The third costal is much thickened for
the reception of the axillary buttress of the plastron, and the fifth and sixth were similarly
thickened for the inguinal buttress. The second costal, near its proximal end, is § mm. thick.

The surface of the carapace presents evidences of a low ridge along the midline. On the
area of the first costal scute there is a low elongated boss; and just in front of it, near the border
of the shell, is a smaller one. In a complete shell there would probably be found a lateral
carina on each side.

The first vertebral scute is small, having probably a length of less than 30 mm. and a
width of 60 mm. The second is 48 mm. long and 65 mm. wide; the third, §7 mm. long and 75
mm. wide. In the original description the figures indicating the widths of the second and the
third had exchanged places. The fourth was fully as long as the third. The first costal
scute is small, being about 36 mm. in fore-and-aft extent.

The plastron lacks the hinder extremity (plate 8, fig. 1; text-fhg. 36). The total length
must have been close to 205 mm. The breadth, measured on the mesoplastra and following
the curves, is 186 mm. The median region is slightly concave as far outward as a ridge which
joins the free border of the anterior lobe with that of the posterior lobe. From this ridge the
lower surface slopes upward and outward to the outer borders of the plastral bones. The
bridge has a fore-and-aft extent of 87 mm. The anterior lobe is short and narrow, the
length being 52 mm.; the width at the base, 72 mm.; at the hinder ends of the epiplastra, 38
mm. The latter bones are small, and they meet along the midline, in front of the entoplastron,
only 5mm. The entoplastron is relatively large, the length being 28 mm.; the width, 17 mm.
Seen from the upper surface, this bone is broadly spear-shaped, with an anteriorly directed
process, a longer one directed backward, and a right and a left process. Its length on this
upper surface is 33 mm. The free borders of the anterior lobe are rounded in section. The
thickness of its various bones is about 7 mm.

On the upper surface of this plastron there is a low ridge passing from one axillary buttress
to the other, making the thickness of the bone at the midline g mm. A similar thickening of the
bones is found between the inguinal buttresses, the thickness becoming 11 mm.

The mesoplastral sutures are distinct everywhere except near the midline in front of the
right mesoplastron. The left mesoplastron is 21 mm. wide at the midline and apparently 43
mm. at the outer end. The mesoplastron of the right side is only 36 mm. wide at the outer end,

re SS The posterior lobe is 83 mm. wide at the
| ieren perl Buse base. It is flat below. On the upper surface

Dimensions. | hatcheri.| marshi. | callosa.| there is a thickening parallel with the free border
on each side. From the summit of the ridge thus
formed the surface slopes to the acute border

|
| Width of bridge...... 1,00 1.00 1.00

| Length of anterior lobe | _.92 58 Ge and toward the midline. Just behind the inguinal
| Width of anterior lobe. 1.00 79 82 notch the thickness of the bone is 14 mm.; where
| Width of hinder lobe.. | 1.04 75 94

the hypoxiphiplastral suture crosses the midline,
only 4 mm. thick.

The sulci are in general distinctly developt. Those behind the intergular are somewhat
obscure. The intergulars do not separate the gulars. The various scutes meet their fellows
along the midline as follows: Intergulars, 12 mm.; gulars, 9g mm.; humerals, 32 mm.;
pectorals, 41 mm.; abdominals 27 mm.; femorals, 40 mm. The length of the anals is indeter-
minable. They lie partly on the hypoplastral bones. On each bridge there are 3 inframar-
ginals, whose outer borders rested on the bridge peripherals.

The table herewith is intended to present the most obvious differences in the proportions
of the plastral bones in the three species, B. hatcheri, B. marshi, and B. callosa. The width of
the bridge is taken as the unit.

It is seen that B. hatcheri has, relatively to the width of the bridge, large anterior and
posterior lobes; that B. marshi has both lobes small; and that B. callosa has the anterior
lobe short and of moderate width, while the hinder lobe is broad at the base.

62 FOSSIL TURTLES OF NORTH AMERICA.

The anterior lobe of the present species is narrower and more pointed than that described
by Lambe (Cont. Canad. Palaont., 111, 1902, p. 44, figs. 10, a, b) under the name B, antiqua.

Baéna antiqua Lambe.
Text-figs. 37, 38.
Baéna antiqua, Lampe, Contrib. Canad. Palzont., 111, 1902, p. 44, figs. 10, a, b.

The materials on which this species was based belong to the Canadian Geological Survey.
‘They were collected in 1go1, in the Judith River beds, on Red Deer River, British America, by
Mr. L. M. Lambe, of the Canadian Survey. The type of the species
consists of the median region of the anterior two-thirds of the cara-
pace. Near it was found the greater part of the anterior lobe of

a ~ the plastron, and this is believed to belong to the same individual.
40 73 The front of the carapace (fg. 37) was apparently broad
ze ee and rounded. The nuchal bone is 28 mm. fore and aft; 58

5 mm. from side to side. The neurals are irregular in form and
outlines. The vertebral scutes are broader than long. The
dimensions of the three present are given in the accompanying table.

No supernumerary costal appears on each side of the first vertebral, such as is found in
many species of the genus.

The fragment of plastron (fig. 38) presents an entoplastron that differs from all others at
present known in being lozenge-: shaped and broader than long. Its length is 22 mm.;_ its
breadth, 28 mm.

Vertebral. Length. Width.

wwe

Fic. 37-—Baéna antiqua. Carapace. Type. 4. Reduced from Lambe’s original drawing. c. p. 1, etc., costal
bones; n. 1, etc., neural bones; nu. p. nuchal bone.

Fic. 38.—Baéna antiqua. Anterior lobe of plastron. >. From drawing by Lambe.

Fic. 39.—Baéna marshi. Plastron of type. X 7o-

Baéna marshi Hay.
Plate 8, fig. 2; text-fig. 39.
Baéna marsht, Hay, Amer. Jour. Sci., XVIII, 1904, p. 261, plate xi, text-fig. 1
The type and only known specimen of this species comes from the Laramie deposits of
Wyoming. It was collected in 1889, by Professor J. B. Hatcher, in Converse County, between
Buck anid Lance Creeks, and is now in the Yale University Museum.

The specimen is considerably damaged. There are present the cast of the greater portion
of the interior of the shell, the greater part of the central portion of the carapace and most of the

BAENID&. 63

left side, and a large part of the plastron. The length of the carapace is conjectural, but it
appears to have been at least 300 mm. The width was 220 mm. Its composition can not be
determined, since the bones have co-ossified and obliterated the sutures. In the median region
the bones reach a thickness of from 10 to 13 mm. The outer surface is smooth. The sulci are
narrow and shallow, and in most places are not traceable. The second, third, and fourth
vertebral scutes varied from 65 to 70 mm. inwidth. The first and fifth were probably somewhat
wider.
The hinder extremity of the plastron (plate 8, fig. 2; text-fig. 39) is missing, so that its
form can not be determined. The anterior lobe has the right border nearly complete to
beyond the midline in front, so that its form is known.
lec a The dimensions of the plastron are shown in the

Dimensions. Batra Coens accompanying table. In order that the distinctness of
marshi. hatcheri. i 5 sy : :
| the species from B. hatcher1 may be seen, the dimensions
| | of the latter are added.

Se een i ae ne The plastron is somewhat concave. The concavity
Length of anterior lobe..| 70 ie extends laterally to a rounded ridge which runs from the
ee ee | adl BS outer border of the anterior lobe to the outer border

t n r eal - 2 a
GAC or Rae Loe a ee of the posterior lobe. From this ridge the outer ends

of the hyoplastron and hypoplastron. extend upward
and outward to the peripherals, and the elevation is
continued on the latter to the carina which unites the free borders of the third and the seventh
peripherals. From the midline of the plastron to the ridge is 55 mm.; from the ridge to the
lateral carina is about 85 mm., the measurements being taken on the mesoplastron.

Most of the sutures of the plastron may be traced. The limits of the entoplastron are
not determinable; nor have the sutures between the xiphiplastra and the hypoplastra been
observed. The mesoplastra meet along the midline for about 23 mm. while their outer ends are
65 mm. wide. The sutures between the plastral bones and the bridge peripherals are distinctly
shown. The whole width of the plastron, on the mesoplastra, and following the curves, is
215mm.

The gular scutes appear to have met for some distance along the midline. The gulo-
humeral sulcus runs nearly directly across the lobe and meets the median line 27 mm. behind
the anterior border. The following are the antero-posterior dimensions of the various plastral
scutes, measured along the midline: Intergulars,17mm.; gulars, 10 mm.; humerals, 46 mm.;
pectorals, 50 mm.; abdominals, 47 mm.; femorals, 53 mm.; anals, 45 mm. On the bridge
there are 4 inframarginals, of which the inguinal is the largest, and the axillary somewhat the
smallest. The outer borders of these overlap on the bridge peripherals.

This species appears to differ from Baéna hatchert in the smaller plastron, the longer
bridge, and the greater thickness of the bones of the carapace, especially of the dorsal region.
It is named in honor of Professor O. C. Marsh, formerly professor of vertebrate paleontology
in Yale University.

Baéna hatcheri Hay.
Plates 9, 10; text-figs. 40, 41.

Baéna hatchert, Hay, Ann. Carnegie Museum, 1, 1901, p. 325, plate xv.—Hartcuer, Bull. U. S. Geol.
Surv. No. 257, p. 79.

The type of the species is a very complete shell which was collected by Mr. J. B. Hatcher,
in the year 1900, in the Ceratops beds of the Laramie formation, in Converse County,
Wyoming. The locality given more particularly is a sandstone bluff on the south side of
Lance Creek, opposite the mouth of Dolgie Creek. The specimen belongs to the collection
of the Carnegie Museum.

The whole plastron is present and all of the carapace except a small portion of the rear.
The sides of the carapace are somewhat crusht in, and some crushing has been suffered by the
bridge peripherals; but these defects do not stand in the way of determining the characters of
the species. It displays all the epidermal sulci and nearly all of the bone sutures. Moreover,
the matrix, a soft sandstone, has been removed, so that the interior too can be observed.

64 FOSSIL TURTLES OF NORTH AMERICA.

The total length of the carapace (plate g) was originally 368 mm.; the total breadth,
280 mm.; the height from the bottom of the plastron, about 145 mm. The greatest breadth
of the carapace was somewhat behind the inguinal notches. From here the border rounds
rapidly to the median excavation behind. The anterior end is rather pointed. In front, the
margin of the carapace is unbroken by serrations or sinuses, except that the nuchal is slightly
excavated. The hinder portion, from the inguinal notches backward, is scallopt as in the
other species of the genus. It is also thin and rather acute. Even at the bridges the border was
narrowly rounded.

Fic. 40.—Baéna hatchert. Type. Fic. 41.—Baéna hatchert. Type.
x}. Carapace. x4. Plastron.

The sutures between the bones are fine and their course is often indicated by only the
finely striated border of the adjoining bone.

The nuchal bone is nearly quadrate in form. It is 43 mm. long fore and aft, with a width
of 59 mm. in front and a maximum width of 72 mm. ‘The neurals in general are hexagonal,
with the broader end forward. The table annext presents the dimensions of the neurals.

The single suprapygal had a length of 50 mm. and a width of 56 mm. No true pygal is
interposed between the peripherals of the last pair.

The costal plates vary considerably in the fore-and-aft extent. Measured at their proximal
ends they have the following widths: First, 48 mm.; second, 40
mm.; third, 47 mm.; fourth, 33 mm.; fifth, 47 mm.; sixth, 32 mm.;

Beuea).1 | lenge. Waste seventh, 32 mm.; eighth, 31 mm. The fifth costal presents the
a |; peculiarity of being very narrow at the distal end—only 9 mm.
I 40 40 The peripherals are high, the first two about 38 mm.; the
a 3° a third, 33 mm.; the next three, about 52 mm.; the seventh, eighth,
3 3 : 5
4 38 33 ninth, about 68 mm.; the tenth, eleventh, and twelfth, about
; 47 33 48 mm. The sutures between the peripherals behind the eighth
- oe 28 are not visible, but they were probably not far removed from the,
8 23 30 lines representing them.

The epidermal scutes are all defined by sulci which are

BAENIDZ. 65

distinct, but very narrow and shallow. The vertebrals are relatively wider than they are in any
of the other species of the genus. From the first vertebral there is cut off on each side an acces-
sory lateral scute, and this has much reduced its size; also, from its anterior end there is cut off
a small supernumerary vertebral, so that there are really 6 vertebrals, as in Chisternon. The
table herewith gives the dimensions of the vertebrals. The width of the central ones is really
somewhat greater than the figures indicate, on account of some lateral compression.

The triangular supernumerary lateral scutes are each 39 mm. fore and aft, and 50 mm.
from side to side.

The area usually occupied in turtles by the nuchal scute is broken up into 4 scutelle
unsymmetrical in form and size. Of these the extreme right and left are larger and much
alike in form and size; the median two are much unlike, one being very small.

Behind the nuchal scutella there are 13 marginals on each side. Usually the costo-marginal
sulci run along some distance below the costo-peripheral sutures. The first marginal extends
back from the border of the shell only 16 mm.; the fourth, 40 mm.; the sixth, 55 mm., and
rises above the costo-peripheral suture; the eighth, 53 mm.; the eleventh, 41 mm. The thir-
teenth is considerably smaller than the twelfth. As in other species of Baéna, there was no
supracaudal scute.

The plastron (plate 10) is rather narrow, especially the hinder lobe. Its total length is
305 mm. The bridge has a width, fore and aft, of 115 mm.; a length, from the inner end to the
border of the carapace, of g5 mm. It rises considerably from the inner end to the outer. The
anterior lobe is 106 mm. long; 115 mm. wide at the base. The width diminishes gradually to
the gulo-humeral sulcus, then rapidly to the midline in front. The thickness of the border of
the lobe is about 8 mm.; behind the entoplastron, about 6 mm.

The hinder lobe is 98 mm. long; 120 mm. wide at the base. The lateral borders are
nearly straight and convergent to the ends of the femoro-anal
sulcus. Here the width is 71 mm. Behind this, the sides are

Vertebral. | Length. | Width. f .
errata Peet 7. nearly parallel for a short distance; then they round rapidly to
~~ the shallow hinder excavation. Just behind the inguinal notch
I 19 32 the thickness is 18 mm.; near the hinder extremity, only 7 mm.
a x 2 The entoplastron is oval, 47 mm. long and 36 mm. wide.

3 75 90 een
4 80 90 The hyoplastrals extend along the midline 85 mm., and each
; 99. ag reaches laterally, behind the axillary notch, 105 mm. There are

55 ‘

large mesoplastrals. The median ends are 24 mm. wide, the
lateral ends, 61 mm. Each extends outward from the midline
125 mm. The hypoplastrals join along the midline for the distance of 75 mm.; the xiphi-
plastrals, 60 mm.

The intergulars and gulars are of about the same form and size, all starting from a point
near the front of the entoplastron. The humerals are 63 mm. long and meet for some distance
behind the entoplastron. The pectorals occupy about 54 mm. of the midline; the abdominals,
about 48 mm.; the femorals, about 78 mm.; the anals, 37 mm.

On the bridge of each side are seen 4 large inframarginals. These lie principally on the
plastral bones, but partly on the peripherals.

The hyoplastra and hypoplastra send upward strong buttresses against the inner surfaces
of the first, and of the fifth and sixth costals respectively ; ; but these buttresses, especially the
inguinal, do not extend inward so far as they do in the other species of the genus. The axillary
Baie is directed upward and forward toward the front of the first dovsal vertebra. Its
inner border is acute. At its upper end the buttress joins the first rib, which is wide and fur-
nisht with a sharp border; thus the partition bounding the sternal chamber anteriorly is
carried up to the first dorsal vertebra. The inguinal buttress, seen from behind, appears to be
about 30 mm. wide; but in front of it the sternal chamber extends far out toward the border of
the carapace.

Baéna escavada sp. nov.
Plate 11, figs. 1, 2; text-figs. 42, 43.

The chelonite on which this species is based was obtained by Dr. J. L. Wortman and Mr.
Walter Granger in 1896, in the Torrejon deposits, at the head of Escavada Creek, in New

5)

66 FOSSIL TURTLES OF NORTH AMERICA.

Mexico. ‘The specimen is not quite complete, being somewhat crusht and fractured and
having a portion of the margin of the left side missing.

The species closely resembles the others of the genus, but possesses sufhciently distinctive
characters. The specific name is that of the stream near which the specimen was found. The
catalog number is 1203, of the American Museum of Natural History.

All traces of the sutures between the bony elements of the shell are obliterated thru co-
ossification. ‘The sutures between the epidermal scutes are distinct, but narrow and only
moderately imprest. The total length of the carapace (plate 11, fig. 1; text-fg. 42) is 381 mm.
In the midline the length is about 12 mm. less, on account of the slight emargination in front
and the excavation in the rear. The breadth was close to 300 mm. ‘The carapace is broad,
ovate, obtusely pointed in front, truncate behind. On each side of the anterior emargination
the border was gently repand. The hinder border, on each side of the excavation for the tail,
was scallopt. On the hindermost part of the carapace there is a moderate rounded keel. From
this there may be traced forward faint indications of the two parallel grooves so distinct in
B. arenosa. Except these grooves, the ornamentation seen in the latter species is absent.

rj
P ‘ : oa
ares F-
. ; / 2
\ /
\ | A]
| eae
\ ze
\ / 3 § i
| a en L
| | ) eee . at hae 43.
42. \ / . ;
| oe
a

Fics. 42 AND 43.—Baéna escavada. Type. 4. Form of shell and the scute areas.
42. Carapace. 43. Plastron.

The most distinctive character of this species is seen in its narrow and spatulate anterior
plastral lobe (plate 11, fg. 2; text-fig. 43). The plastron as a whole is relatively small. The
total length is 295 mm. The anterior lobe has a length of 83 mm. and a breadth, at its base, of
g6 mm. From the base the lateral borders run forrond and inward to within 30 mm. of the
front, at the ends of the sutures between the gular and humeral scutes. Here the width is 61
mm. Beyond these points the lobe expands again to 64 mm.; then curves forward and inward
to the ends of the intergular sutures. The extreme end of the lobe is truncated and falls about
30 mm. short of the anterior border of the carapace.

The posterior lobe has a width of 114 mm. at the base and a length of 75 mm., failing to
reach the excavation in the carapace by about 47 mm. It narrows, as it passes bacleyaxde more
rapidly than does that of B. arenosa. The hinder border is slightly concave.

The bridge has a width of 135 mm. Its length, to outer margin of the shell, is 105 mm.

BAENID&. 67

The vertebral scutes are relatively narrow, the second having a length of 88 mm.anda width
of 65 mm.; the third a length of 85 mm. and a width of about 70 mm.; the fourth a length of
80 mm. ead a width of 70 mm.; the fifth a length of 48 mm. and a width of 80 mm. In the
case of the first vertebral the same lack of symmetry is to be seen as has been observed in so
many other specimens belonging to the genus Baéna.

The costo-marginal sulci are distant from the edge of the carapace about 22 mm. Those
subdividing this anterior marginal region are too obscure for certain determination. There
are indications of one which crost this region about 15 mm. to the left of the midline. There
was, therefore, probably a nuchal scute 30 mm. long from side to side. Beyond this the
marginals increase in length and breadth. Over the bridge they rise on the sides of the
carapace 45 mm.

On the plastron are distinct gulars and intergulars. The humero- pectoral sulcus crosses the
midline on the line joining the axillary notches. Laterally the sulcus is suddenly turned forward
and outward. The pectoral scutes meet along the midline for a distance of 53 mm., and extend
laterally about 72 mm. The abdominal scutes occupy 52 mm. of the midline; the femorals 67
mm.; the anals 50mm. As in other species of Baéna, the suture between the femorals and the
anals runs outward, then turns backward for some distance, then again outward.

There are 4 large inframarginals.

Baéna arenosa Leidy.
Plate 12; plate 13, fig.1; plate 14, figs. 1-3; text-figs. 44-51.

Baéna arenosa, Letpy, Proc. Acad. Nat. Sci. Phila. 1870, p. 123; U. S. Geol. Surv. Wyoming, etc.,
1870 (1871), p- 367; U. S. Geol. Surv. Montana, etc., 1871 (1872), p. 368; Contrib. Ext. Vert.
Fauna W. Terrs., 1873, pp. 161, 343, pl. xiii, figs. 1-3; fpl. xv, figs. 1-5; pl. xvi, figs. 8, 9. —Copr,
?Append. LL of Ann. Report Guick of Engineers, 1875, p. 96; ?Wheeler’s Surv. rooth Merid.,
1877, p. 52, pl. xxiv, fig. 32.—Baur, Proc. Acad. Nat. Sci. Phila. 1891, p. 426, fig—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 437.

Baéna affints, Leroy, Ann. Report U. S. Geol. Surv. Wyoming, etc., 1870 (1871), p. 367.

Baéna arenosa, the type of the genus Baéna, was based on a shell lacking only the anterior
lobe of the plastron and the anterior border of the carapace. This specimen is now in the
United States National Museum at Washington. It was figured and described at length in Dr.
Leidy’s work of 1873. The specimen was obtained in the Bridger deposits, at the junction of
the Big Sandy and Green Rivers, in southwestern Wyoming. These beds are regarded as
belonging to the lowermost of the Bridger formation.

The specimen described by Leidy evidently had originally a length of close to 340 mm. and
a width of 288 mm. The rear of the carapace is broadly rounded: The vertebral scutes are
broader than long. The hinder lobe of the plastron is broad and it narrows slow ly backward.
The width of the anterior lobe, taken from the outer ends of the humero-pectoral sulci, equals
half the length of the plastron behind this. Dr. Leidy states that the position of the former
sutures can not be detected. This is true as regards the outer surface of the bones; but on the
upper side of the plastron the sutures on each side of the mesoplastrals are to be observed.
The left mesoplastron had a width of about 25 mm. at the midline; that on the right side was
narrower.

A portion of the pelvis and the sacral vertebra and ribs of this specimen were figured by
Dr. Leidy. Later, Dr. Baur obtained from the matrix of the specimen additional parts of the
pelvis and briefly described them. While some parts are still wanting there is enough to show
that the ischia were united with the pubes along the midline and that the pubes extended at
least 35 mm. in front of their hinder border at the midline (figs. 44, 45). The upper end of
the illum was expanded backward. The width of this expanded part was equal to the height,
35 mm.

The writer follows Dr. Leidy and Professor Cope in identifying the former’s B. ajfinis as
the earlier described B. arenosa. The original description of B. affinis was exceedingly brief and
hesitating. It was supposed to be distinct from B. arenosa because of the presence of only
3 inframarginals. In Leidy’s next reference to the species, he referred it to his earlier B.
arenosa. The type is now in the collection of the Philadelphia Academy. It was

68

FOSSIL TURTLES OF NORTH AMERICA.

obtained at Church Buttes, in the level known as B. Dr. Leidy’s figure makes the anterior
lobe of the plastron appear too short and too narrow. The plastron has a total length of 275
mm. The anterior lobe is 75 mm. long and 70 mm. wide at the base. The bridge has a width
of 123mm. The hinder lobe is 77 mm. long and 110 mm. wide at the base. The carapace has
straight line. The surface is uneyen, especially within the areas of the

a length of 300 mm. ina

Type of B. No.
| Werte: affints. A.M.
bral.
Length. Width. Length. Width.
1 50 2 48
2 73 61 72
3 73 64 77
4 6o 63 62
5 55 75 57

5973

Nets

vertebral scutes. There appear to have been no supernumer-
ary costal scutes. The dimensions of the vertebrals are given
in the accompanying table.

The American Museum expedition of 1903 collected a
number of specimens which must be referred to this species.
The most important of these is No. 5973, collected at Grizzly
Buttes, Wyoming. It furnishes a somewhat damaged shell,
the skull, lacking the left side and the lower jaw; a portion of
the shoulder-girdle; the humerus, lacking the distal end; and
the ulna. The length of the carapace (plate 12) in a straight
line is 330 mm., to the bottom of the posterior notch, 320 mm.;
its width, about 315 mm. The bones are thoroly co-ossified

and the sutures obliterated. The anterior border projects somewhat at the midline. The pos-
terior border is broad, with a median excavation 60 mm. wide and lateral scallops.

Fics. 44-48.—-Baéna arenosa. No. 5973 A. M.N. H.

44. Pelvis seen from left side. 3. 47. Left humerus. X 3.
45. Left half of pelvis seen from below. 3. 48. Right ulna. 3.
46. Plastron. >}.

On each side of the first vertebral there is a small supernumerary costal scute. Along the
midline there is a narrow ridge and within the areas of the vertebral scutes a number of sym-
metrically arranged ridges.

The plastron (plate 13, fig. 1; text-fig. 46) is 287 mm. long. The anterior lobe is 77 mm.
long; 104 mm. wide at the base; and 77 mm. at the gulo-humeral sulcus. The limits of the
entoplastron can not be traced. The bridge is 125 mm. wide. By means of the striations on the

The dimensions of the vertebrals are given in the table above.

BAENIDA. 69

bones the limits of the mesoplastrals can be pretty well determined. They appear to have
joined each other at the midline for a distance of about 25 mm. The hinder lobe is 84 mm.
long; 114 mm. wide at the base; and g2 mm. wide at the gulo-humeral sulcus. At the rear
there is a broad and shallow notch. ‘The plastral scutes offer no especial deviations from the
normal. ‘Their forms and dimensions may be determined from the figure. On each of the
bridges there are 3 inframarginals.

The right humerus (fig. 47) lacks the distal end. Its length has been approximately 70 mm.
The resemblance to that of Chelydra is close. The head is, however, not so large, and especially
it is comprest in a plane perpendicular to the dorsal surface of che bone. Furthermore, the
plane of this comprest head inclines to the radial side of the humerus; whereas, in Chelydra,
it falls far outside of the ulnar side. The ulnar and radial processes are large and the distance
from the outside of one to the outside of the other measures 32 mm. In the case of the humerus
of the type of B. riparia this distance is only 26 mm. In B. arenosa, as well as B. riparia, the
planes of the two processes are at right angles with each other, as in Chelydra. The processes
are much thicker than in Chelydra. The shaft has a diameter of 8.25 mm. The groove
leading to the ectepicondylar foramen is broad and deep. A fragment from near the distal end
of the left humerus has a width of 21.5 mm. The right ulna ( (fig. 48) is present. The shaft is
not flattened like that of the Cryptodira, but is nearly cylindrical, like that of Hf ydromedusa.
The articulation for the humerus is, however, like that of the Cryptodira. The bone is 52 mm.
long; 15 mm. wide at the distal end.

Plate 14, figs. 1-3, represents what is left of the skull. The occipital condyle and the
premaxilla are wanting, but the length between these two was close to 60 mm. The greatest
width (plate 14, fig. 1) Just in front of the ty mpanic cavities was 62 mm. From the tips of the
nasals to the extremity of the supraoccipital i is 57mm. All the sutures of the roof of the skull
are obliterated. The tympanic cavity (plate 14, fig. 2) has a horizontal diameter of 15 mm. and
a vertical of 18 mm. The stapedial rod remains in its natural position. The eyes appear to
have lookt upward and outward more than in Chisternon hebraicum (fig. 78, p. 8g), and were
smaller. The orbits are circular with a diameter of 16 mm. The interorbital space is 22 mm.;
the nasal opening, 20 mm. wide; the maxilla, below the eye, 10 mm. wide. Seen from below

(plate 14, fig. 3), the cutting-edge of the maxilla is sharp, thickened upward to 5 mm., and at
least 30 mm. long. There is a prominent ridge on the triturating surface of the maxilla, highest
on each side of the choanaz. The least width across the pterygoids i is 13 mm. From the outer
posterior angle of the basioccipital bone a strong ridge runs forward toward the basisphenoid.
The basisphenoid did not come into contact with the vomer. Unfortunately, the lower jaw 1s
missing.

On the upper side of the skull are seen numerous anastomosing grooves, the boundaries of
horny scutes that covered most of the upper surface. Some of aiece are represented in fig. 1
plate 14.

The skull differs from that of Chisternon hebraicum in having a wider interorbital space,
a smaller eye, and far more prominent masticatory ridges on the upper jaws. It is most like
that of B. rrparra. Unfortunately, both skulls are damaged, so that full comparison is not pos-
sible. The two skulls are of almost exactly the same size. The snout of B. arenosa was broader,
as was also the interorbital space. The eye of B. r:paria appears to have had a greater vertical
diameter, but of this we can not be certain at present. In B. riparia the maxilla below the orbit
is only g mm. wide. In B. riparia the ridge along the junction of the basisphenoid and the
pteryg goid is far less prominent. In this species, too, therel is a low ridge running from the pedicel
of the quadrate to meet the free border of the pterygoid. Another: starting from the same
point, runs forward and upward along the suture between the quadrate and the pterygoid.
The surface of the bone between these two ridges is somewhat scoopt out. In B. arenosa the
ridges are little developt and the space between them is convex.

No. 1115 of the American Museum is identified as belonging to the present species. It
was collected by the museum’s expedition of 1893 into southwestern Wyoming. The locality
whence it was obtained is Laclede Meadows, southwest of Bitter Creek station and west ot
Haystack Mountain. The deposits belong to the Washakie formation. Of this individual the
front and a part of the right border of the carapace (fig. 49) and the front of the anterior lobe
of the plastron (fig. 50) are missing. The remainder of the shell is well preserved. It had origi-

7O FOSSIL TURTLES OF NORTH AMERICA.

nally a length of about 395 mm., measured in a direct line. The greatest width, 340 mm., 1s
across the middle of the length of the carapace. Across the axillary notches the width is 315
mm., and that taken 25 mm. in front of the hinder extremity of the plastron is 306 mm. It will
be seen therefore that the extremities of the shell are broad. The height of the shell is now 145
mm. but it was doubtless greater during life.

Fics. 49 AND 50.—Baéna arenosa. X}. No. 1115 A. M.N. H.

49. Carapace. Shows the scute areas. Front injured.
50. Plastron. Shows many of the bones and the scute areas. Front restored.

The hinder border of the carapace (fig. 49) is rather thin and acute, scallopt as in the
other species of the genus, and flared somewhat upward. The anterior border is obtuse. All
the bones are thoroly co-ossified, so that the forms of the neurals
can not be determined. The surface is uneven, and especially

Vertebral. | Length. Width. . 5 :
in the areas occupied by the vertebral scutes there are various
longitudinal, transverse, and oblique ridges. A slight depression
- fe occupies the midline of vertebrals 3 and 4. The accompanying
2 79 . . . a
3 30 95 table gives the dimensions of the vertebral scutes. In general,
4 80 go they are wider than long.
5 75 100 .

As is not infrequent in the species of the genus, there are, on
the left side at least, 5 costal plates. The most Anterior is cut
from the front of the one usually called the first; altho the most anterior vertebral is reduced
somewhat in width thereby. The portion of the rim of the carapace between the outer border
of the small anterior costal scute and the posterior vertebral is occupied by 12 marginal scutes.

The plastron (fg. 50) has an even, but granulated, surface. The anterior lobe is 133
mm. wide at the base. The bridges are 155 mm. wide. The limits of the mesoplastra are
indistinctly discernible. They were about 20 mm. wide at the midline and expanded distally
to about go mm. The hinder lobe is 141 mm. wide at the base and 105 mm. long. It dimin-
ishes in width slowly backward and the end is truncated. At the ends of the femoro-anal sulci
the width is yet 113 mm. The lobe lacks about 60 mm. of reaching backward to the hinder
border of the carapace.

BAENID&. 71

On the left" bridge there are four inframarginal scutes. Of these the second is the smallest,
the first and the fourth the largest. All the ‘plastral, as well as the carapacial scutes, agree
closely with those of Leidy’s type.

A portion of the pelvis is preserved (fig. 51). So far as can be determined, it agrees well
with that of the type of the species. Unfortunately, the upper end of the ilium is missing.

Professor Cope figured and described what he regarded as a specimen of B. arenosa (Vert.
Tert. Form. West, p. 148, plate xvi, figs. 1,2). The specimen is in the American Museum and
has the number 1112. The present writer regards it as belonging to B. riparia.

Professor Cope has described and figured also a portion of a carapace found by him in the
Wasatch beds of New Mexico. As the type of B. arenosa
was discovered in the lowermost beds of the Bridger, it is
not impossible that the species may occur in the Wasatch;
but the identification based on a part of the shell is not
to be depended upon.

However, the American Museum expedition of 1906
into the Wasatch deposits of Wyoming secured a specimen
of Baéna which is referred to this species. This was found
near Knight’s Station, not far from Evanston. The level
was about 200 feet above Bear River. The catalog number
of the specimen is 6041. About one-third of the carapace
in front has been eroded away, but otherwise the shell is
in fair condition. The length of the carapace was origi-
nally about 240 mm. The width at the middle of the length
is 222 mm., and this width is fully maintained to opposite the ends of the femoro-anal sale.
So far as can be determined this specimen differs from most Bridger specimens in the greater
smoothness of the areas of the vertebral scutes; but this appears to have been nearly the
condition of Leidy’s type. Cope’s specimen obtained in the Wasatch of New Mexico and
referred by him to the present species had the back sculptured as in most Bridger specimens.
It appears best, until more is known about the Wasatch form, to identify it as B. arenosa.

2
3°

Fic. 51.—Baéna arenosa. X
Pelvis seen from below.

Baéna sima sp. nov.
Plate 13, figs. 2, 3; plate 14, figs. 4-6; plate 15; text-figs. 52-56.

The present species has for its type No. 5971 of the American Museum of Natural History.
This specimen was collected by that museum’s expedition of 1903 into the Bridger beds. The
locality is on Little Dry Creek, south of Fort Bridger, and the level is that designated as B. The
specimen furnishes nearly the whole of the shell, the skull, with the lower jaw, a number of
vertebra, and portions of the limb bones.

The bones of the shell are so thoroly co-ossified that few of the sutures can be made
out. The carapace (fig. 52) has an axial length of 360 mm.; the width was close to 260 mm.
It was apparently rather elevated. There is no depression along the midline. In outline the

—— —__ Carapace was pointed i in front and somewhat contracted behind.
Wengen | “Width: Posteriorly there is in the border, over the tail, a rather deep

Vertebral.

igen excavation 72 mm. wide. The posterior peripherals are flared
: ‘ ‘e upward. The surface of the carapace is very uneven, being
3 81 6 everywhere covered with coarse pustular elevations; just outside
4 79 82 of the third and fourth vertebral scutes there are some longitu-
5 4 8 dinal wrinklings. About 25 mm. outside of these vertebrals there

SSS SS are seen on each side distinct traces of a lateral carina. The
median symmetrically arranged folds and grooves seen in B. arenosa are here quite indistinct.
The nuchal scute has a fore-and-aft width of 16 mm. and a transverse extent of about 40mm.
The first vertebral is 51 mm. long and 80 mm. wide; but there appears to be on the left side
a small supernumerary costal scute cut out of its normal area. The other scutes have the areas
given in the table.
Outside of the nuchal scute there is, on each side, a minute triangular marginal scute.
The next one, the second, is 21 mm. long on the free border and 21 mm. high. The third is

72 FOSSIL TURTLES OF NORTH AMERICA.

38 mm. long and 15 mm. high. The seventh, lying below the hinder half of the second costal, is
56 mm. long and it rises about 36 mm. above the free border of the shell. On account of the
obtuse border over the bridge the elevation of the lateral scutes is difficult to estimate.

The plastron (fig. 53) is 320 mm. long. The anterior lobe is 92 mm. long, 112 mm. wide
at the base, and 80 mm. wide at the gulo-humeral sulci. The bridge has a width of 138 mm., 60
per cent. of the length of that part of the plastron behind the axillary notches. The hinder lobe
is 92 mm. long, 127 mm. wide at the base, and g2 mm. at the ends of the femoro-anal sulci.
The hinder border is slightly excavated.

The mesoplastra are solidly co-ossifed with the contiguous bones, but some traces are
found of the sutures. The bones appear to have been about 15 mm. wide at the midline.

The forms of the various plastral scutes are shown in the figure. The course of the median
sulcus is very tortuous and there are some irregularities in the others. The axillary region is
damaged on both sides, but appearances indicate that there were 3 left inframarginals, the

52. 53:

Fics. 62 AND 52.—Baéna sima. Type. 1. Showing the form of carapace
3 5 4 g P
and plastron and the scute areas.

52. Carapace. 53- Plastron.

pectoral scute apparently having extended out to the marginals. There is a large inguinal
inframarginal and another in front of it. There was doubtless an axillary scute, but the bones
are missing which supported it. On the right side there were 4 inframarginals.

The skull of this species (plate 13, figs. 1, 2; plate 14, fig. 4) is remarkable for its breadth
and shortness. The premaxillary region is missing and likewise the condyle of the basioc-
cipital; but the length from one to the other was very close to 64 mm. The breadth across the
quadrates is 71 mm. From the quadrates the outline of the skull contracts rapidly to below
the front of the orbits, where there is a sudden constriction. From this the outline contracts
slowly, then rounds into the broad snout. The upper surface is convex. All the bones are
solidly co-ossified, and no sutures are to be traced.

The temporal foss are rooft over extensively, so that between the end of the short
supraoccipital and the postero-lateral angles there is on each side only a shallow sinus. The
interorbital space is 26 mm. wide. The orbits have their greatest diameter, 17 mm. directed per-

BAENID&. 73
pendicularly, while the horizontal diameter is only 14 mm. The narial opening ts 21 mm. wide
and it looks strongly upward as well as forward. The bones roofing it are 6 mm. thick. The
tympanic region 1s damaged, but the vertical diameter was 20 mm. The quadrate is deeply
notcht for the passage of the stapedial rod.

At their narrowest part the pterygoids are 14 mm. wide. There are large postpalatine
foramina. The front of the choane is placed 17 mm. behind the premaxille. The cutting-
edges of the maxille converge at nearly right angles. The triturating surface is 7 mm. wide.
At its inner border, on each side of the choanz, arises a sharp crest. These crests converge to
the front of the choana, then run parallel to near the premaxille, thus producing a deep
groove in front of the choanz.

The lower jaw (plate 14, figs. 5, 6) is thick and heavy. From the middle of a line joining
the front borders of the articulation for the quadrates to the tip of the jaw is 4o mm. This line
prolonged backward even with the extremities of the rami would measure about 52 mm. while
the greatest width was 60 mm. The triturating surfaces are concave transversely, and are 7
mm. wide. The middle of each ramus is 9 mm. thick and 15 mm. high. The tip of the jaw is
turned upward, beak-like. The length of the symphysis on the lower side is 21 mm.

The upper surface of the skull was undoubtedly covered with numerous horny scutes.
These are shown, as far as determined, in plate 13, fig. 1. They are somewhat irregular in
form and disposition, but there is no difficulty in making out some symmetry in their arrange-
ment. The horny covering of the maxilla appears to have been divided, for a deep sulcus runs
downward from the front of the orbit to the cutting-edge.

Fics. 54-56.—Baéna sima. No. 5907 A. M. N. H.

54. Pelvis, right side. X}- 56. Digit. XX. 55- Distal end of humerus. 4.

Accompanying the shell of this specimen are various portions of the internal skeleton,
mostly fragmentary, however. The left humerus is represented by the proximal and the distal
ends. The proximal shows a width, from the outside of the ulnar to the outside of the radial
process, of 33 mm., a single millimeter more than in the specimen of B. arenosa, No. 5973,
above described. Nevertheless, the long diameter of the head is 14.5 mm.; that of No. 5973,
13mm. The ulnar process has a thickness of 11 mm.; that of No. 5973 a thickness of g mm.
The distal end of this bone is 27 mm. wide. The trochlea has a narrow rounded ridge for the
head of the radius and a broader one for the head of the ulna, the two being separated by a
groove. Above the trochlea is a deep olecranon depression. The prepubic process resembles
that represented in fig. 86, but it is thin and flat. With this specimen are found 3 conical dermal
bones whose bases were buried in the skin, the remainder being covered with horn. Two ot
these are symmetrical and may have been placed on the midline of the upper side of the tail, as
in Chelydra. However, they are not comprest, but circular in section. The base of one is 10
mm. in diameter and the height is the same; the other is smaller. The third is unsymmetrical
and somewhat flattened. It 1s possible that on the tail were 3 rows of dermal bones or there
may have been dermal bones on the legs, as in some species of Testudo.

No. 5965 may be regarded as the paratype of the present species. It furnishes only the
carapace and plastron. It was secured in 1903, at Grizzly Buttes, Wyoming. The carapace is
more complete than that of the type and has furnisht plate 15. The length is 333 mm. along

74 FOSSIL TURTLES OF NORTH AMERICA.

the midline. The height, after some crushing, is still 132 mm. The scallops of the hinder
border are shallow. The surface of the carapace is sculptured as in the type. The symmetrical
ridges and grooves found in B. arenosa and B. riparia are here obscure. On the hinder half of
the carapace there are a few irregular longitudinal folds and a system of anastomosing
ridges and pustular elevations. The outer ends of the costal scute areas, the marginal areas,
and the whole anterior half of the carapace are much smoother. The nuchal scute is not
divided. On each of the bridges there were four inframarginal scutes. The bridge region of
fig. 53 has been completed from this specimen.

No. 5907 of the American Museum was collected in 1903 by the writer at Grizzly Buttes,
Wyoming. It may be regarded as a second paratype. It furnishes the shell, fragments of the
skull, fhe pelvis, and some limb bones. The shell appears not to have been distorted by
pressure. The plastron has exactly the length of that of the type. The width of the carapace
is 290 mm.; the height above the bottom of the plastron, 150mm. On the right bridge there
are only 3 inframarginal scutes, and the pectoral scute joins the sixth marginal. On the carapace
the nuchal scute is not divided longitudinally. On each side, as in the: other specimens, is a
small marginal followed by a much ‘larger one, that on the right side being larger. The super-
numerary costals are not found at the sides of the first vertebral.

The pelvis is represented by fig. 54. The shaft of the ilium, where narrowest, has a diam-
eter of 10 mm. The expanded head is 34 mm. high and 33 mm. wide, while in Chisternon
undatum the head is considerably higher than wide. The pubis is thin, 4.5 mm., slightly
convex aboye, concave below. ‘The pelvis resembles closely that of the type of B. arenosa.

Fig. 55 is that of the distal end of the humerus, seen from above. The radius is a terete
bone 57 mm. long. Fig. 56 represents one of the digits. The right femur is 78 mm. long and is a
stout bone with a minimum diameter of 8 mm. The plane passing thru the strongly comprest
head falls outside the tibial border of the distal end far less than in a specimen of Trachemys
elegans. ‘The tibia had a length somewhat exceeding 63 mm., and the least diameter of the
shaftis7mm. The distal end of the fibula has a width of 13 mm.

The greater portion of the lower jaw is present and it is of the same heavy construction as
that of the type. Fragments of the roof of the skull show that the bones in the midline, behind
the orbits, were 7 mm. thick.

Baéna clara sp. nov.

Plate 16, figs. 1, 2; text-figs. 57, 58.

This species is based on a nearly complete shell which was collected by the American
Museum expedition of 1893. It was obtained in the Bridger beds of Wyoming and bears the
number 1675. The exact level and locality are not known. Only unimportant portions of the
front of the carapace are wanting.

The extreme length of the carapace (plate 16, fig. 1) is 362 mm.,; its width across the middle,
where it is widest, is 300 mm. The shell is but little distorted by pressure. It is elegantly oval
in form, with the edges of the hinder border of the carapace furnisht with shallow scallops,
and with a deep excavation in the rear, as if for a large tail. The shell is flat transversely in the
region occupied by the vertebral scutes. There is no carina, except along the fifth vertebral
scute. Immediately i in front of this, for a short distance, there is a narrow median ridge, like
that seen in B. arenosa. Over and behind the posterior legs the shell is flared Guevard and
slightly upward. In front and behind the bone is rather thin; but anteriorly it soon thickens,
so that over the fore legs it has a thickness of about 15 mm. At the sides the margins of the
shell are massive.

The carapace is smooth, with only some faint indications of the sculpturing seen in B.
arenosa.

The plastron (plate 16, fig. 2; text-fig. 58) has a length of 333 mm. in the midline. It was
flat as far out as the bridges. From the inner ends of these the plastron rises upward and
outward to the margins of the carapace, so that the latter stands some 50 mm. above the level
of the plastron. ‘The highest part of the shell stood above the plastron about 150 mm.

The anterior lobe of the plastron is tongue-shaped, rounded in front, and feebly notcht.
In the figures it appears foreshortened, having been prest upward during fossilization. Its

BAENID&. 75
width at its base is 125 mm.; its length in the middle line is g0 mm. At a point half-way
between the tip and the base the width is 88 mm. The width of the bridge is 145 mm. The
hinder lobe of the plastron is broadly tongue-shaped, with the tip truncated and broadly
notcht. Atits base this lobe is 125 mm. wide; and in the midline it is 100 mm. long.

The sutures between the various bones of the shell are usually very obscure, but most of
them are determinable. The limits of the neurals (fig. 57) are somewhat conjectural. Those
between the costals and the peripherals run probably close to the sulcus between the costal and
peripheral bones. The most anterior peripherals, however, rise above this sulcus.

The sutures of the plastron are hard totrace. Only the general course of those limiting the
entoplastron and the epiplastra is discernible. The sutures between the bones of the plastron
and the peripherals lie about 44 mm., mesiad of the shell margin. At a point about 40 mm.
behind the axillary notch is observed the suture between the hyoplastron and the mesoplastron.
Its course is inward and somewhat backward to a point in the midline about 66 mm. behind the
line joining the axillary notches. Another distinct suture may be observed about 38 mm. in
front of the inguinal notch on the left side. It can be traced toward the midline, where it
becomes obscure. This suture is that between the mesoplastron and the hypoplastron. Thus
the inner ends of the mesoplastron are about 24 mm. wide.

Fics. 57 AND 58.—Baéna clara. Type. +.

57. Carapace. 58. Plastron.

At a point in the midline about 45 mm. behind a line joining the inguinal notches the
sutures between the hypoplastra and the xiphiplastra are seen running nearly directly outward.

The impressions defining the epidermal scutes are usually very distinct. The sides of the
vertebral scutes are bracket-shaped. The lateral boundaries of the first vertebral run nearly
parallel and the scute is nearly as wide in front as it is behind. It has a length of 56 mm., a
posterior breadth of 63 mm., and an anterior breadth of about 58 mm. The lateral sulcus
on the left side is deflected somewhat toward the right side as it passes forward. It is possible
that an accessory lateral scute is cut off from the front of the usual first lateral scute and lies
to the left of the first vertebral. It is provisionally represented in the diagram above.

76 FOSSIL TURTLES OF NORTH AMERICA.

The second vertebral scute is go mm. long in the midline, and is 72 mm. wide across its
middle. Similarly, the third scute is 87 mm. long and 72 mm. wide; the fourth, 75 mm. long,
deeply concave behind, and 75 mm. wide. The fifth scute is 35 mm. long and 100 mm. wide.
Its posterior edge comes to the border of the shell, there being no supracaudal.

The anterior marginals are somewhat damaged. In front there is a nuchal scute 30 mm.
from side to side and 16 mm. fore and aft. On the mght side there are 2 small marginals,
each about 15 mm. long. On the left side there is 1, perhaps 2, corresponding marginals. Then
follows, on each side, a marginal about 44 mm. long, piceeeded by several Others of about
the same or greater length. Further behind they shoeten gradually, and the last one is very
small. The first long marginal has a height of 20 mm. at its middle; the majority of them
have a height of about 38 mm. Further behind the height is less.

The iets running along the midline of the plastron pursues a very irregular course, and
the same is true of some of the others. That behind the gulars runs arn the midline
outward and backward for half its length, thence forward and outward. That defining the
intergulars does not, at the midline, quite reach the one behind the gulars. The pectorals are
about 87 mm. wide at the midline; the abdominals about 35 mm.

The sulcus between the femorals and the anals is extremely irregular. The right
femoral at the midline is 62 mm. wide, the left, 78 mm. wide. There are four inframar-
ginal scutes. The first, or axillary, is 58 mm. long and 40 mm. wide; the second has the form
of a trapezium, with outer and hinder borders each about 40 mm.; the third is four-sided,
50 mm. long, 60 mm. wide. The inguinal scute is pentagonal, about 46 mm. long and broad.

A second specimen belonging apparently to this species, No. §957 of the American Museum,
was collected in the Bridger beds in 1903. It has the first vertebral scute symmetrical, 43 mm.
wide in front, 65 mm. wide posteriorly. ‘There is on each side of it a triangular super-
numerary costal scute.

From B. arenosa the present species differs in displaying with considerable distinctness
the sutures between the various bones. In no specimens of B. arenosa that have hitherto been
collected have the sutures of the carapace been observed. It is unlikely that this disappearance
of the sutures is due to greater age of the specimens of B. arenosa. Furthermore, the cara-
pace of B. arenosa has a quite elaborate sculpturing along the middle of the back. Of this
B. clara shows only the merest suggestions. The rear of B. clara is scallopt, but the cuts
are much shallower than in the other species. The vertebral scutes of B. clara are narrower
than those of B. arenosa. However, the most striking differences between B. clara and the two
species above mentioned are found in the shape of the shell. The outline of B. clara is oval.
The widest part is across the middle of the length and from this the border curves gracefully
toward the front and rear. In B. arenosa the outline is somewhat quadrate. The: sides are
approximately parallel as far back as the rear of the plastron; then the border turns abruptly
toward the midline.

Baéna riparia sp. nov.
Plates 17, 18; plate 19, figs. 1-3; text-figs. 59-66.
Baéna arenosa, Core, Vert. Tert. Form. West, 1884, p. 148, plate xvii, figs. 1, 2 (not of Leidy).

Baéna riparia has as its type a fine shell and skeleton, a prize of the American Museum
expedition of 1903 into the Bridger deposits of southwestern Wyoming. It was found at the
Grizzly Buttes, about 15 miles southeast of Fort Bridger. The beds belong to those designated
as B. The specimen is in the American Museum of Natural History and hes the aumber 5977

The carapace (plate 17; text-fig. 59) of this specimen is slightly crusht on the left ide
and the hindermost peripherals are mostly gone; otherwise the Sie is complete. The cara-
pace is especially valuable because the Bones are not co-ossified, and practically all the
elements may be determined. It has an axial length of about 315 mm., a slight dislocation ot
the bones of the rear making the estimate inexact. The width is 260 mm. From the middle
of the length the width oe gradually to the somewhat projecting front. The rear hasa
wide but shallow sinus over the tail. In fig. 59 the outline of the rear behind the eighth periph-
eral to near the pygal is somewhat conjectural, but must be close to the real condition.
Along the middle of the back there runs a distinct channel which extends out beyond the
neural bones. Along the middle of this there is seen a narrow ridge, on each side of which

»

BAENIDZ. 77

is a groove. From a point a little behind the center of each vertebral scute a few folds radiate
to the ends and angles of the scutal areas. Outside of these areas the surface of the shell is
somewhat uneven.

The anterior neurals are widest in front, very narrow behind. The three or four posterior
are wider. The sutures are somewhat irregular. Only 7 neurals can be determined. The
ee seventh is larger than the others and corresponds to the seventh
and eighth costal plates; but no suture can be seen crossing it.
The nuchal bone is slightly broader than long, 46 mm. by 35
| — mm. The pygal, somewhat damaged, is broader than long.

a ‘i The peripherals do not differ greatly in height, this being about

7 57 27 mm. ‘There were apparently 12 of these bones on each side.

68 61 The sulci are distinctly imprest, but narrow. The nuchal

50+ go+ j x ome nae : : a ‘ .
| scute 1s distinctly divided into a right and a left. At each side of
= it is a minute triangular first marginal. The second marginal is
33 mm. long on the free border; the third, 39 mm.; the eighth, 38 mm. The dimensions of
the vertebral scutes are shown in the table.

(Vertebral. Length. | Width.

ApwWrn He

aN
‘ ac infm ™. :
Se

Fics. 59 AND 60.—Baéna riparia. Type. 3.

59. Carapace, showing bones and scute areas.

60. Plastron. ab, abdominal scute; an, anal scute; ent, entroplastron; ep, epiplastron; fem, femoral scute; g,
gular scute; hum, humeral scute; hyo, hyoplastron; hypo, hypoplastron; infm, inframarginal scutes;
mes, mesoplastron; pec, pectoral scute; x1ph, xiphiplastron.

There are on each side 5 costal scutes, a small supernumerary one being situated on each
side of the first vertebral. Whether there are 13 or 14 marginals is uncertain. There is no
supracaudal scute occupying the midline over the tail.

The plastron (plate 18; text-fig. 60) is 262 mm. long on the midline. Its width is close to
200 mm. As in the other species of the genus, it sends upward strong axillary and inguinal
buttresses. The former rise to within 25 mm. of the first dorsal vertebra. They are joined

78 FOSSIL TURTLES OF NORTH AMERICA.

by the ribs of the vertebra mentioned. These buttresses extend inward from the sides of the
shell, forming partitions whose inner borders are distant from each other 85 mm. The upper
ends of the inguinal buttresses rise high against the contiguous borders of the fifth and sixth
costal plates. Between the axillary and the inguinal buttresses of each side there is a deep
sternal chamber.

The anterior lobe is 70 mm. long, 90 mm. wide at the base, and 64 mm. at the gulo-humeral
sulci. It contracts gradually to these sulci, then sweeps round to the midline. The free
border is obtuse and the greater part of the lobe is 10 mm. thick. The entoplastron is long and
narrow, its length being 45 mm., its width 26 mm. The mesoplastra fail by about 16 mm. of
reaching the midline. Laterally they expand to a width of 64 mm. The bridges are 116 mm.
wide—62 per cent. of the length of that part of the plastron behind the axillary notches.

The hinder lobe is 78 mm. long, 114 mm. wide at the base, and 80 mm. at the femoro-anal
sulci. The hinder border is slightly notcht. The free borders are subacute. At the inguinal
notch the thickness of the bone is 18 mm., but backward it thins to about 4 mm.

The intergulars and the gulars both overlap the entoplastron. On each bridge there are
3 inframarginals, an axillary, another at the end of the pectoro- -abdominal sulcus, and an
inguinal. The pectoral scute comes into contact with the sixth marginal.

Faq

Fics. 61-66.—Baéna riparia. Type. x3.

61. Scapula. 65. Femur, dorsal view.
62. Coracoid. 66. Right hind leg.
63. Humerus, dorsal view. 66a. Femur.

64. Humerus, radial border.

The skull (plate 19, figs. 1, 2) of this specimen is considerably
damaged. Most of the temporal roof is missing, as are the squa-
mosals and the premaxilla. The length from the latter bones to
the occipital condyle was close to 57 mm.; the breadth across the
quadrates is 56 mm. ‘The orbit has a perpendicular diameter of 17
mm., a horizontal diameter of 15 mm., being somewhat larger than the orbit of B. stma, which
had a larger skull. The interorbital space is 18.5 mm. wide. The nasal opening is 17 mm.
wide. The narrowest part of the pterygoids 1 is 13mm. wide. On the inner border of the tritu-
rating surface of each maxilla there is a sharp ridge, as in B. sima.

The lower jaw (plate 19, fig. 3) of this species differs greatly from that of B. sima, being of
much lighter construction and having a shorter symphysis. ‘The distance from the tip of the jaw
to the saddle of a line joining the front of one articulatory surface for the quadrate with that
of the other 1s 40 mm., the same as in the type of B. sima. The distance from the outside of one
of the articulatory surfaces to the other is 50 mm., much less than in B. szma. The height
of the middle of a ramus is 10 mm., the thickness 7 mm., the width of the gutter-like triturating
surface 4mm. The length of the lower side of the symphysis is 15 mm. Of the sutures of the
upper surface of the skull the median, running between the nasals, prefrontals, frontals, and
parietals, and the transverse which separates the parietals from the frontals, are determinable.

BAENIDE. 79

The course of the parieto-frontal suture is different from that of Chisternon hebraicum, since
mesially it is placed further forward and runs outward and somewhat backward to the orbit.
The upper surface of the skull appears to have been covered with horny scutes.

All of the cervical vertebra are present, except the first. The whole series had a length of
close to 100 mm., not quite one-third the length of the carapace. All have transverse processes.
All have a sharp crest on the lower side of the centrum. These crests are so deep that they
would have interfered greatly with any considerable flexure of the neck in a perpendicular
plane. The second centrum is flat anteriorly, very concave posteriorly. The third is moder-
ately convex in front, deeply concave behind. The fourth has the anterior end concave in the
center, but the concavity is surrounded by a broad convex wall. The hinder end is shallowly
concave. The fifth is rather deeply concave in front, flat behind. From the outside of one of
the postzygapophy ses to that of the other of the vertebra is 13 mm. The centrum of the sixth
cervical 1s concave in front. The form of the hinder end can not be observed. The front of
the seventh is concave, the hinder end flat. The eighth is concave in front; the hinder end is
quite convex, but small. The first dorsal has a large concavity to receive the convex surface
of the eighth cervical. This concavity looks directly forw ard, as in the Pleurodira, not down-
ward as in the Cryptodira. This is another indication that the head and neck were not
retracted within the shell. In the hindermost of the cervicals the zy gapophyses stand high
above the centra. Furthermore, the ends of the centra, especially when they are flat or
convex, are considerably higher than wide. Both these conditions would be unfavorable to
the flexure of the neck in a perpendicular plane. The postzygapophyses of the last cervical
and the prezygapophyses of the first dorsal are short, not long and curved like those of the
Cryptodira. On the other hand, the lateral motion of the neck could hardly have been so free
as in the Pleurodira; and there was no projecting roof of the carapace under which the head
could be concealed. We must conclude that these turtles could protect their heads hardly more
than the sea-turtles. ;

The ascending portion of the scapula (fig. 61) is long and slender; as is also the precoracoid
process. The coracoids (fig. 62) are somewhat damaged; but it is evident that the median end
was not greatly expanded, not so much as in some E mydidae. The humerus (figs. 63, 64) is
67mm. long. The shaft is little bent. The distance from the outside of the radial process to the
outside of the ulnar is 27 mm. The breadth of the distal end is 21 mm. The ectepicondylar
foramen is situated g mm. above the condyle. The humerus is slightly longer in propor-
tion to the length of the carapace than in Graptemys, but not so long as in Chelydra. The
ulnar process doce not extend so far above the head as in Chelydra. The remainder of the
fore limb is missing.

The pelvis is badly crusht, but there appear to be no striking differences between it and that
of Chisternon hebrarcum (figs. 85, 86). The ossified prepubic process is long, and it resembles
that of the species just mentioned. The femur (figs. 65, 66) is 68 mm. long and moderately bent.
In proportion to the length of the carapace the femur is shorter than that of Graptemys and
still shorter than that OF Chelydra. The tibia and the fibula (fig. 66) are each 53 mm. long.
The tarsal bones and some of the metatarsals are preserved. ana second metatarsal is 21.5
mm. long. This appears to indicate a rather long foot.

The tail was long. Eleven of the vertebra are preserved, having a length of 143 mm.;
and there were evidently several more. So far as determinable, they were convexo-concave. All
probably bore chevron bones. Some of the anterior caudals have, in the position of the neural
spine, a rounded boss, as if for the support of a distinct bone, such as occurs on some of the
caudals of Chelydra.

The specimen figured and described by Cope (Vert. Tert. Form. West., p. 148, pl. xvii,
figs. 1, 2) as Baéna arenosa is now in the American Museum of Natural History and has the
catalog number 1112. Cope’s figures are one-fourth the size of nature and are inverted. His
measurements are in some Cases erroneous. The carapace is 320 mm. long, instead of 450 mm.
The carapace is somewhat crusht and its transverse diameter was nearer 260 mm.than 240 mm.
The length of the plastron is 290 mm. The anterior lobe is 82 mm. long; the posterior lobe
87mm. The width of the base of the anterior lobe is 102 mm.; that of the base of the posterio1
lobe, 116 mm. The width of the anterior at the gulo-humeral sulci is 71 mm.; that_of the

so FOSSIL TURTLES OF NORTH AMERICA.

posterior at the femoro-anal sulci, 87 mm. As stated by Cope, there are three inframarginal
scutes on each bridge. The present writer regards the specimens as belonging to B. riparza.
The sutures are obliterated.

Baéna emiliz sp. nov.

Plate 20, figs. 1, 2; text-figs. 67, 68.

The type of this species is a nearly complete shell, No. 1925, of the American Museum of
Natural History and was collected in 1894, by Mr. O. A. Peterson, in the middle Uinta of Utah.
Through pressure the left side has been crusht in and small portions there are missing; the
edges of some of the posterior right peripherals are also broken off. On one side or the other
all parts are present. The elements of the shell are not co-ossified, and we are therefore able
to determine the limits of nearly all the bones entering into its composition.

The length of the carapace, measured in a straight line, is 368 mm. (plate 20, fig. 1; text-
fig. 67). Its greatest width, taken at the middle of the length, is 294 mm.—almost exactly
the size of the specimen described as B. clara and not much smaller than the specimen of B.
arenosa, No. 1115 of the American Museum. It may therefore be conveniently compared
with them.

67. |

Fics. 67 aND 68.—Baéna emilie. Type. 4. Shows bones and scute areas.
67. Carapace. 68. Plastron.

The form is much like that of B. arenosa, being rather wide behind, 245 mm. at the hinder
end of the plastron. The posterior border is furnisht with 5 or 6 scallops, the cuts between
which are of a depth intermediate between those of B. arenosa and B. clara. The upper midline
is slightly channeled, except on the last vertebral, where there is a prominent carina.

The plastron (plate 20, fig. 2; text-Ag. 68) resembles in general that of the other species,
but the anterior and the posterior lobes are comparatively narrow. The total length is 320 mm.
The anterior lobe has a length of 80 mm., a width of 110 mm. The tip is evenly rounded, the
lateral border first convex, then further back concave; so that its width at the middle of its
length is only 8r mm. The posterior lobe has a length of 83 mm. and a width of 122 mm. at the
base. Its posterior border is nearly straight. The width of the bridge is 160 mm. The plastron
comes within about 40 mm. of the end of the carapace.

This species agrees with B. clara in having only 4 costal scutes, instead of 5. The lateral
margins of the ae vertebral are parallel anal they meet the marginals. Then the edge of the

BAENIDA. 8

vertebral runs forward and inward to the midline. The table below gives the dimensions of
the vertebral scutes. These are narrower than they are in B. arenosa of the same size, and
the third is longer than in any of the described species. There are 5 small marginal scutes

4 ae a ee lying in front of the first vertebral. Two of these, quadrilateral
in form about 26 mm. long and 20 mm. wide, occupy respectively

Vertebral. | Length. Width.
| the night and left thirds of the front border of that vertebral. A
a pentagonal scute 25 mm. from side to side occupies the middle
2 third. It measures 15 mm. fore and aft; and its narrowed front
3 92 75 scarcely reaches the margin of the shell, since two other small
4 ig a scutes come in front of it, one on each side. No sulcus is seen
. -

along the midline.

The lateral marginals of B. emilia are higher than they are in
either B. arenosa or B. clara. The upper border of the one below the-anterior angle of the third
costal scute stands about 50 mm. above the lower edge of the shell. In the specimen of B.
arenosa, No. 1115, larger than the shell being described, the corresponding marginal hardly
reaches 40 mm. The: upper borders of the marginals of B. emilie appear to fallow closely
the sutures between the peripheral bones and the costal plates.

There appear to be 13 marginals on each side, including the minute anterior one.

The epidermal sulci of the carapace are deeply imprest; those of the plastron are rather
obscure. The intergulars reach about two-thirds the distance to the humero-gular sulcus.
There is a row of 5 inframarginals on each side. As to the other plastral scutes, it is not
observed that they are especially different from those of B. arenosa.

It is possible to trace the sutures between all the bones of the shell, except those sur rounding
a few of the anterior neurals and some of the posterior peripherals; but even these may be
located approximately.

It will be observed that the nuchal does not have the great antero-posterior extent that it
does in the recent Pleurodira. The neurals are in general elongated hexagonal, with the broad
end forward. The first and second measure together 83 mm., and the Font one is probably
a little the shorter. Of their width one can not be certain. The third is 55 mm. long, and
apparently 30 mm. wide, the fourth, 43 mm. long, 27 mm. wide; the fifth, 43 mm. long, 31 mm.
wide; the sixth, 35 mm. long, 32 mm. wide; the seventh: 30 mm. long, and the same in width;
the eighth, 30 mm. long, and 34 mm. wide. Behind the last neural comes the pygal, 30 mm.
long and 60 mm. wide. No suprapygal is found between the last neural and the pygal. The
eighth costal plate occupies the whole lateral border of the eighth neural and, in addition,
the postero-lateral portion of the seventh neural.

The nuchal bone has a fore-and-aft extent of 37 mm. Its width from side to side is about
50 mm. in front and about 85 mm. behind.

There are almost certainly 12 peripherals on each side. The most anterior sutures are
easily distinguisht; but, for various reasons, not the posterior ones. Over the bridges the
sutures between the peripherals are continuous with the sutures between the costal bones;
posteriorly, there is not this correspondence. The sutures are not traceable, but there is
undoubtedly one between each two epidermal sulci.

On the plastron all the sutures are easily distinguisht. ‘The total length of the plastron is
320mm. The epiplastra meet in the midline by a suture 13 mm. long; the length of each bone
is 42 mm. The entoplastron resembles that of 6. arenosa, as figured by Leidy ( (Cont. Ext.
Fauna W. Terr., pl. xv, figs. 4, 5). Its length is 40 mm.; its breadth 34 mm. The suture
between the hyoplastra is g6 mm. long. The ae ool meet in the midline for a space
of 33 mm. At their outer ends they are 75 mm. wide. The suture between the hypoplastra
is 87 mm. long. The xiphiplastral suture is 50 mm. long, and each, measured at its anterior
end, is 50 mm. wide. The anterior and posterior buttresses of the plastron are like those of
Be arenosa.

The intergulars measure on the midline 18 mm.; the gulars, 9 mm.; the humerals, 51 mm.;
the pectorals, 84 mm.; the abdominals, 42 mm.; the femorals, 64 mm.; the anals, 54 mm.
On the bridge are 5 inframarginals.

In the middle line above there are some longitudinal ridges and grooves and some irregular
elevations, which are rudiments or vestiges of an ornamentation similar to that of B. arenosa.

6

82 FOSSIL TURTLES OF NORTH AMERICA.

This species differs from B. arenosa in the form of the anterior vertebral scute and in
having no accessory lateral scute. In these respects it agrees with B. clara. From the latter it
differs in having the shell broader behind, a wider and more deeply scallopt postero- -lateral
border, higher lateral marginal scutes, a different arrangement of the most anterior marginal
scutes, and narrower plastral lobes. The bridge of the plastron is also wider. It measures
160 mm., while that of the type of B. clara is only 150mm. The bridge of B. arenosa, No. 1115,
a larger shell, also measures only 150 mm. On the under side of the postero-lateral border of
the shell. at the fifth scallop, the distance from the line where the soft skin of the animal began
to the outer edge of the shell is 40 mm.; in B. clara this space is only 33 mm.

There is in the American Museum’s collection a second specimen of this species from the
same level. It is somewhat smaller, with a total length of 323 mm., and is less perfect than the
one which has furnisht the above description. Nevertheless, the principal characters distin-
euishing the species from the others are exhibited. Altho smaller, the sutures have almost
wholly disappeared, so that it furnishes no aid in tracing these.

In the collection of Princeton University there is a somewhat damaged shell which is
referred to this species. The catalog number is 11263. It was collected by Mr. J. B. Hatcher,
in 1895, in the Uinta Eocene, at Kennedy's Hole, Utah. The beds contained remains of
Dolichorhinus cornutus.

Genus EUBAENA nov.

Skull resembling that of Baéna, but with the temporal region less extensively rooft over,
the squamosals not coming into contact with the parietals. Jugals excluded from the rims of
the orbits. “Triturating ice: of the maxilla transversely broad and concave. Choane
opening between the orbits: and at nearly one-third the distance from the snout to the occipital
condyle. Shell unknown.

Type : Eubaéna cephalica Hay.
Eubaéna cephalica Hay.
Plate 19, fig. 4; plate 21, figs. 1, 2.

Baéna cephalica, Hay, Amer. Jour. Sci. (4), XvI, 1904, p. 262, plate xu, figs. 1-3.

The name Eubaéna cephalica is given to a fine skull which is in Yale University Museum.
This skull, which lacks only the lower jaw, was collected in the Laramie deposits of Converse
County, Wyoming, by Professor ]. B. Hatcher, then employed by Professor O. C. Marsh. The
specimen bears Bastescon Marsh’s receipt number 2110.

In general form the skull is broad behind, rather flat above, and with pointed snout. The
length from the snout to the occipital condyle is 67 mm.; to the end of the supraoccipital
spine, 74mm. The greatest breadth, just in front of the tympanic chamber, is 65 mm. From
these chambers the width diminishes to the snout. The flat upper surface of the skull descends
each way to the perpendicular sides. The sides of the face about the orbits look upward and
outward, as well as forward. The tympanic opening is nearly circular, 19 mm. 1n its perpen-
dicular, 15 mm. in its horizontal axis. The orbit is circular and small, its diameter being 14mm.
The interorbital space is 25 mm. wide. The nasal opening, as seen from in front, 1s somewhat
heart-shaped, and is directed above and forward. From the orbit to the tympanic opening is
24mm.; from the nares to the orbit is 10 mm.

The temporal region is rooft over, but not so extensively as in species of Baéna from the
Bridger beds. On each side of the supraoccipital this roof is excavated as far as a line joining
the anterior borders of the tympanic chambers. From the orbit to the bottom of the excava-
tion is 22mm. The hinder end of the postfrontal is interposed between the parietal and the
squamosal.

In general, the sutures of the skull are very distinct, but no trace has been found of those
between the frontals and the parietals. There are distinct nasals, and these and the prefrontals
resemble closely the same bones in the Bridger species of Baénide. The prefrontal of each
side joins the postfrontal, so that the area of fie frontal is excluded from the border of the orbit.
The sagittal suture extends from the prefrontals to the supraoccipital spine, a distance of

BAENIDZ. 83

42mm. The postfrontal is large, having a length of 32 mm., being in contact by its lower
border with the maxilla, the jugal, and the quadratojugal; and by its posterior border with
the squamosal.

The jugal is small, being only 8 mm. in length and 15 mm. in heigth. The squamosal forms
the hinder border of the tympanic opening. Superiorly it has a thin crest, a relic of the former
backward extension of the temporal roof. The tympanic chamber extends backward into this
bone. The lower border of the zygomatic bar is considerably excavated. Seen from the side the
maxilla is convex on its lower borden. From this border the bone rises 11 mm. to the orbit.
The premaxill are distinct from the maxilla and from each other. At the symphysis they are
only 3 mm. high, but at the union with the maxilla, 10 mm. high. As in the Bridger species
of Baéna there are distinct lacrimal bones. The lower border of each comes into contact
with the vomer. The jugals are excluded from the rims of the orbits (Plate 19, fig. 4).

As seen from below, the maxilla has a broad masticatory surface, its width being 14 mm.
from its inner border to the cutting-edge. The inner border of this surface is fairiisht by the
palatine bone. The latter forms the whole of the outer border of the choana. The masticatory
surface does not extend forward on the premaxilla. In front of the choanz there is a deep
groove, which in front expands on the lower surface of the premaxilla. There are postpalatine
foramina (Plate 21, fig. 2).

The pterygoids come into short contact with the maxilla. They have distinct ectoptery-
goid processes. Where the hinder part of the palate is constricted it is 18 mm. wide. The
pteryg goids extend backward to the hinder border of the pedicel of the quadrates, thus sepa-
rating the latter widely from the basioccipital and basisphenoid. ‘There is a considerable
groove between the quadrate on each side and the median bones of the skull. The pterygoids
join in the midline for a considerable distance in front of the basisphenoid. There is on each
side of the latter bone, about the middle of its length, a venous foramen.

The pedicels of the quadrates are short. The surface for articulation with the mandible
is deeply concave from side to side, nearly plane from front to back.

A pair of epidermal scutes appears to have occupied the space between the anterior
halves of the orbits. Behind each of these and bounding the hinder half of the orbit was a
smaller scute. A very large scute, or more probably a pair of them, occupied the area of the
frontal bones and overlapt behind this on the parietals. The hinder half of this scute, or
these scutes, if two, was separated by two median scutes. The more anterior of these last was
circular; the more posterior was broadened backward and lay on the whole or part of the
supraoccipital processes of the parietals.

Eubaéna latifrons sp. nov.

Figs. 69, 70.

The specimen on whrch the present species is based was found by Mr. Barnum Brown, of
the American Museum of Natural History, in Laramie deposits, on Seven Mile Creek, W yom-
ing, about 40 miles northwest of Edgemont, South Dakota. It has the catalog number 6139.
The specimen consists of the Silo without the lower jaw. This skull is crusht downward
somewhat, and the right maxilla is forced inward partly over the triturating surface of that
side. The left maxilla is missing. A part of the temporal roof is broken away and most of
the supraoccipital spine is gone.

It is not impossible that the shell of this species has already been described as one of the
Laramie species of Baéna; but this can not be determined until the skull and the shell have
been found together. The skull resembles that of E. cephalica; but a number of differences
exist, which will be mentioned as the description proceeds.

How far the premaxilla extended beyond the front of the nasal bones can not be deter-
mined exactly; but the distance appears to have been less than in is ce phalica. It may be
assumed to have been about 5mm. The length of the skull, from the front of the nasals to the
occipital condyle, is 72 mm. The width from one quadratojugal to the other is 73 mm.
Evidently the orbits looked upward less than in E. cephalrca, for the width of the interorbital
space is 32 mm.; in E£. cephalica, only 25 mm. The horizontal diameter of the orbit is 17 mm.
being thus more than in the species with which it is compared. The tympanic chamber, too,

$4 FOSSIL TURTLES OF NORTH AMERICA.

is larger than that of the other species, the horizontal diameter being 24 mm. The perpen-
dicular diameter is now only 16 mm., but this is due, no doubt, to crushing. From the orbit to
the tympanic cavity 1s 22 mm,

The roofing of the temporal region resembles that of E. cephalica. Few of the sutures of
the upper side of the skull can be traced with certainty; but it is evident that the parietal
union with the squamosal had been severed by the excavation in the hinder border of the roof.
There are reasons for believing that the parietals were each 15 mm. wide posteriorly. If the
prefronto-nasal suture is where it seems to be, the nasals were unusually large, running along
the midline 8 mm. The parieto-frontal and the fronto-prefrontal sutures can not be deter-
mined with certainty. The nasal opening has now a width of 23 mm. One premaxilla 1s
present and has the height and the width each 9g mm. The maxilla, below the orbit, is 11 mm.
wide, being thus narrower than that of E. cephalica.

The upper surface of the skull is rough with narrow ridges, separated by sharp furrows.
‘This interferes with the tracing of the sutures; for the latter do not appear to be really absent.
Occasional narrow grooves indicate that the skull was covered with horny plates; but these
can not be mapt.

ee
\ SEA

Fics. 69 AND 70.—Eubaéna latifrons. Skull of type. X#.
69. Skull seen from above. jo. Skull seen from below. pmx, premaxilla; va, vorner.

The base of the skull and the roof of the mouth resemble in general the same regions of
E. cephalica. At the pterygoid constriction the width is only 16 mm. The postpalatine
foramina are placed 24 mm. apart; whereas, in E£. cephalica they are only 18 mm. apart. The
maxillary triturating surfaces appear not to have been so wide as those of EF. cephalica. As in
the latter species, they are bounded on the inner margin by a rough ridge.

Genus CHISTERNON Leidy.

Related closely to Baéna, but having 2 bones, an anterior and a posterior, occupying the
region of the nuchal of Baéna. Normally 2 scutes occupying the area corresponding to the first
vertebral of Baéna. No supramarginals. Maxilla with a nearly plane triturating surface.

Type, Baéna undata Leidy.

The genus was based by Dr. Leidy on the presence of the mesoplastra, but these were after-
wards found to be present in Baéna arenosa also. The existence of the two bones in the region
of the nuchal, with the absence of supramarginals, will characterize the genus.

Two specimens of C. undatum and one belonging to Cope’s Baéna hebraica in the American
Museum of Natural History show unmistakably the two bones mentioned as occurring in the
region of the anterior neural.

Remarks on the significance of the preneural and the supernumerary scutes will be found
on page 57.

BAENIDA. 85

Chisternon undatum Leidy.
Plate 22; text-figs. 71-75.

Baéna undata, Lewy, Proc. Acad. Nat. Sei. Phila. 1871, p. 228; U.S. Geol. Surv. Montana, ete., 1871
(1872), p- 369. —Corr, 6th Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 622; Vert. Tert.
Form. West, 1884, p. 147, plate xix, figs. 3-5.—Osporn, Scott, and Sprer, Contrib. Mus. Geol. and
Arch. Prinéeton Univ., No. 1, 1878, p. 96.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438.

Chisternon undatum, Lerpy, Proc. Acad: ne Sei. Phila. 1872, p. 162; Contrib. Ext. Patina West. Terrs.
1873, pp. 169, 341, plate xiv, figs. 1,

The type of Leidy’s Chisternon undatum is in the collection of the Academy of Natural
Sciences at Philadelphia. The specimen is said to have been collected in a range of buttes a few
miles from Fort Bridger. This range is probably Grizzly Buttes and the lev elis B. The shell
belonged to a turtle whose carapace had a length of about 485 mm. The front and the rear of
the shell are missing, so that Leidy could not Pnew the structure of the bones and scutes of the
front of the carapace. As stated by that author, the shell is rather high and archt, its upper
surface standing above the bottom of the plastron about 7.5 inches, equal to 190 mm. The
sutures may be fracca by means of the band of striations that crostthem, and Leidy was enabled
to map correctly the bones of the plastron. The mesoplastra come to a point at the midline.
The costo- marginal sulci over the bridges run about 50 mm. above the borders of the shell.

Fics. 71 AND 72.—Chusternon undatum. Carapace and plastron.

71. Plastron of No. 3932 A.M.N.H. X }. Anterior lobe missing.
72. Carapace of No. 5959 A.M.N.H. x }. Areas of some bones not mapt.

Many characters given by Cope as distinguishing this species from C. hebrarcum are not
conclusive. There is no appreciable difference in the sizes of the anterior lobes; nor do the
intergular and gular scutes of C. undatum always start from a common point. So far as the
writer has observed, the marginal scutes of C, hebraicum rise considerably higher above the
margins of the shell over the ‘bridges than they do in C. undatum. As will be shown below,
there are important differences in the skulls.

In the American Museum there are 4 large shells which are regarded as belonging to this
species. In none of these are the boundaries of all the bones to be made out, altho in some of
them many sutures may be traced. ¥

No. 3932 (plate 22; text-fig. 71) was collected in 1893 in the Bridger beds of Wyoming, but
the exact locality and level are unknown. The length along the midline is 433 mm.; the

86 FOSSIL TURTLES OF NORTH AMERICA.

greatest width, 387 mm. The outlines of many of the neural bones are determinable. On the
front of the carapace, however, the indications are obscure. The vertebral scutes are a little
longer than wide. The scutes on the front of the carapace are unsymmetrical. On the left
side there is a supernumerary costal, but not on the right side. The anterior vertebral is not
transversely divided as it is in the other specimens. Over the bridges the marginal scutes are
not more than 45 mm. high. The,anterior lobe of the plastron is missing. On the left bridge
there are only three inframarginal scutes.

No. 5974 was collected in 1903 near the mouth of Cottonwood Creek, in the level called B’.
It has a length of 490 mm. along the midline, and a maximum width of 425 mm. The rear of
the carapace is scallopt. Most of the sutures are indistinct, but the small nuchal and the
large preneural are plainly separated. The former is 38 mm. long and 46 mm. wide; the latter,
45 mm. long and 72 mm. wide. The first vertebral scute is transversely divided, so that there
are present really 6 vertebrals. On each side of the two anterior ones 1s a supernumerary costal,
and an extra scute has been cut off from the first vertebral and the right supernumerary costal.
The marginals over the bridges appear not to run more than 50 mm. above the borders of the
shell. The plastron is 440 mm. long. The entoplastron has a length of 80 mm. and a width
of about 45 mm. The mesoplastral sutures are not wholly distinct, but these bones appear
to have come to a point at the midline. The anterior lobe is 120 mm. long; 150 mm. wide at
the base; 93 mm. wide at the gulo-humeral sulci. The bridge is 205 mm. wide. The hinder
lobe has a length of 125 mm.; a width of 155 mm. at the base, 122 mm. at the femoro-anal
sulci. On each bridge are 4 inframarginal scutes. The gulars meet each other for a dis-
tance of 13 mm. at the midline.

>
> hd

Fics. 73-75.—Chisternon undatum. Skull of No. 5962 A. M.N.H.

toe

73. Skull seen from above. 74. Skull seen from below. 75. Right half and tip of lower jaw.

No. 5959 (fg. 7) was obtained at Grizzly Buttes, Wyoming, in 1903. ‘The axial length of
the carapace is 455 mm.; its width, 400mm. As in No. 3932, there i is a broad depression along
the midline of ee carapace. There is a distinct nuchal bone, followed by a larger preneural.
There are 6 vertebral scutes, whose dimensions are given in the accompanying table.

There is a small supernumerary costal scute on each side of
the first vertebral scute and another on each side of the second
(fig. 72). The border of the shell over the ght bridge is crusht,
but the costo-marginal sulci appear to have run not more than

Vertebral. Length. Width.

I 35 36 60 mm. above the border of the shell. The entoplastron is 80
2 g2 . . .

2 ss ae mm. long and about 48 mm. wide. On the right bridge are five
3 95 95 pag 5, z z : : ee = g

4 105 97 inframarginals. The left bridge is missing.

5 Joh 96 No. 5962 was collected at Grizzly Bate! in 1903. It was
6 69 105 59 9 Be

lying close to No. 5961, a specimen of C. hebraicum. The cara-
pace is much crusht laterally and diagonally. The specimen is
valuable because it furnishes the skull. The carapace was at least 460 mm. long. So far as
can be determined, the costo-marginal sulci pursued their courses above the bridges at a moder-
ate height. There are 6 vertebral scutes and a pair of supernumerary costals in front. There
are traces of the suture between the nuchal and the preneural.

Most of the dimensions of the skull (figs. 73, 74) are presented on page 8g. It differs from
that of C. hebrarcum especially in the broader triturating surfaces of the maxilla and the broader

BAENID. 87
pedicels of the quadrates. There appears to have been only a rudimentary ridge on the
triturating surface. The sutures between most of the bones may be traced, but those separating
the frontals from the parietals have not been observed. Nasals were quite certainly present, but
they are broken away. The lower jaw is present (fig. 75). The triturating surface is trans-
versely concave and g mm. wide. The tip of the jaw is damaged so that the length of the
symphysis can not be exactly determined; but it was not far from 15 mm.

Chisternon hebraicum Cope.
Plate 21, figs. 3, 4; plate 23, fig. 15 text-figs. 76-87.

Baéna hebraica, Corr, Paleont. Bull. No. 1, 1872, p- 463; Proc. Amer. Philos. Soc., x11, 1872, p- 4635
6th Ann. Report, U.S. Geol. Surv. Terrs., 1872 (1873), p- 62; Vert. Tert. Form. West, 1884, p. 146,
plate xix, figs. I, 2.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438.

Baéna undata, Hay, Bull. Amer. Mus. Nat. Hist., XX1, 1995, P- 138, figs. 1-3.

Professor Cope’s type of the present species consists of about two-thirds of the anterior
portion of the carapace and the plastron. It was obtained by him in the Bridger Badlands
along Cottonwood Creek, Wyoming, and hence in the level known as B. This type is now in the
U.S. National Museum at Washington. It appears to be necessary to correct some of Cope’s
measurements. The transverse axial width
is given by him as 500 mm., but it is only

Nu Dp

Le Spren XP oN 420mm. Accordingly, Cope’s figures are

a aa RS ; just one-third the size of nature. Cope’s
Dea o nay \ estimate of the length was also 500 mm.,
j Cpe aah OE dims We BS but the writer would make it only about 425
SN ‘ mm. In either case the shell is about as

{ \ broad as long. The length of the anterior

i aa, ‘ lobe of the plastron, to a line joining the

i . _\ bottoms of the axillary notches, is 125 mm.

- Its width is 147mm. The bridges are 162

ae : mm. wide. The hinder lobe has a basal

width of 160 mm.

As shown by Cope’s figures, the nuchal

we } i ~ and the anterior marginal scutes have small

ee extent at right angles with the free border,

i ee and the first vertebral is transversely divided

so as to make 6 vertebrals in all. Themargi-

Fic. 76.—Chisternon hebratcum. Portion of carapace. nals over the bridges are higher than long,

x4. No. 5961 A. M. N. H. and the corresponding costal scutes become

thereby about as high as long. There is

likewise a supernumerary costal scute on
each side of the first vertebral.

The shoulder-girdle is present, but has not been wholly freed from the matrix. The
scapula is at least 90 mm. long from the glenoid fossa to the upper end. At its base the cora-
coid has a diameter of 7 mm.; ata distance of 65 mm. from the glenoid fossa the diameter 1s
65 mm.

No. 5961 of the American Museum is referred to this species. It was collected in 1903 by
Mr. L. S. Quackenbush, a member of the museum’s party. The locality is Grizzly Buttes,
not far from the locality where Cope’s type was collected. It was found lying in close prox-
imity with the specimen numbered 5962 and referred to Leidy’s Chisternon undatum. Both
specimens furnisht good skulls and other skeletal parts. Figure 76 represents the carapace
of No. 5961; fig. 77, the plastron. The shell, especially in the region of the distal ends of the
costals, is thin and fragile and some parts were lost. The right half of the nuchal is gone, the
rear of the carapace is missing.

The axial length of the carapace was close to 474 mm.; the greatest width 435 mm. It was
moderately convex. The surface 1s nearly smooth. Along the areas of the vertebral scutes

are some traces of the sculpture so conspicuous 1n the case of species of Baéna. Across some ot

cu pPat; front costal plate; c.s. 1, first costal scute; .1, 7.2,
neural bones; pren, preneural.

88 FOSSIL TURTLES OF NORTH AMERICA.

the intercostal sutures are a few of the grooves described by Cope. Fortunately the sutures
between the bones are yet open, so that the whole structure can be observed. The most
striking feature of the carapace is the presence of two bones in the region usually occupied by
the nuchal,asmall anterior and a large posterior. The anterior bone (fig. 76,nu.p), here regarded
as the true nuchal, has awidth of 52 mm. and a length, fore and aft, of 30mm. The other bone,
the preneural (fig. 76, pren), is 75 mm. wide and 38 mm. long. The first neural is pyriform,
the others hexagonal, with the wider end forward.

The first three peripheral bones are each 42 mm. high.
Those over the bridges have a height of about 65 mm.

Neurals. Vertebrals. 3 fy ae >
There are 6, instead of 5, vertebral scutes, the areas usually

No. a 5 Set 2 :

covered bythe first being transversely divided. The dimensions
Length, Width. Length. Width. of the neurals and vertebrals are shown in the table.
The nuchal scute is small and was probably not divided
1 44 42 40 70 along the midline. It is 24 mm. wide and 10 mm. fore and
Z 57 ch 2 i|p C2 aft. The first marginal is small and triangular. The second
3 60 39 111 115 fe 5 5 :
Fi ee 30 «0s, | aig | has a length of 25 mm. along the free border and a height of 16
5 48 38 of mm. The third is not so high. Those marginals over the
6 : 34

bridge rise above the borders of the costal bones and have
a height of approximately 70 mm.

A little of the hinder border of the plastron (fig. 77) is broken away, but the total length
was very close to 415 mm. In general it resembles the plastron of species of Baéna. The length
of the anterior lobe is 113 mm.; its width at the base, 160 mm.; at the outer ends of the gulo-
humeral sulci, 85 mm. The entoplastron is 65 mm. long and 45 mm. wide. The symphysis of
SO the epiplastra is only 14 mm. long. From

x

pe the entoplastron the hyoepiplastral sutures
ee run outward and backward. The bridge
4 has a width of 180 mm. The mesoplastra
{ join at the midline for a distance of 20 mm.,
( the left one being somewhat the wider.

They expand outward to awidth of 105mm.

The length of the hinder lobe was
originally about 105 mm. Its basal width is
175 mm.; at the hypoxiphiplastral suture,
145 mm.; at the femoro-anal sulci, 120
mm. The thickness of the center of the
anterior lobe is 11 mm. Between the
axillary buttresses, on the upper surface,
runs a broad ridge which thickens the bone
to 15mm. A similar ridge crosses from
one inguinal buttress to the other. From

C3 ale the latter buttresses a ridge runs backward
BiG: 77.—Chisternon hebratcum. Plastron. » i. No. near each free border of the hinderlobe, and

5961 A. M. N. H. Shows bones and scute areas. thru these the thickness is 17 mm. The
central part of the hinder lobe is concave.

The skull (plate 21, figs. 3, 4; plate 23, fig. 1; text-fgs. 78-81) of this specimen is nearly
complete, lacking only a part of the left maxilla, and the premaxilla. At the time the writer
publisht his figures of this skull, he had not yet discovered the differences between this
specimen and that numbered 5962, described here as Chisternon undatum. In order to allow
comparisons the measurements of the two skulls are given in the table on p. 89.

There is a difference of only 5 mm. in the lengths of the skulls. There is a difference of this
same amount in the widths of the maxilla below the orbits, a difference of 8 mm. in the widths
of the skulls at the quadrates, a difference of 6.5 mm. in the distances from the orbit to the
tympanic cavity.

The skull is short, broad behind, wedge-shaped in front. The temporal region is broadly
rooft over and the squamosal comes into contact with the parietal.

BAENID. 89

Nasals are present. The frontals are triangular, with one apex directed to the corre-
sponding orbit, without reaching it. The exoccipitals meet in the midline neither above nor
below the occipital foramen. The occipital condyle belongs wholly to the basioccipital. On
the lower side of the skull the pterygoids exclude the quadrates from contact with the basioc-
cipital and the basisphenoid. The latter bone does not quite reach the vomer. On each side

Chisternon Chisternon
hebratcum, undatum,
No. 5961. No. 5962.
Length from front of inaxilla to occip. condyle 67 72
Width across the quadrates....... Danes 69 77
Diameter of tympanic cavity..... oe ayers 16.5 21
Breadth of temporal roof from orbit.......- : 24 29
Diameter of orbit.......-..++. ees 20 2355
Interorbital space........-.+++++-> ae : 20 23
Breadth of maxilla below orbit.........----+- 8 13
Width of pterygoids....... a mc eutenes 175 17.5
Width of hinder end of maxilla from outside of
cutting-edge to suture with palatine. .. . ‘ 11 15
| Orbit to border of tympanic cavity. ...--...5055 18.5 25
Width of pedicel of quadrates on level with palate 16 20

of the basioccipital is a foramen, doubtless for a vein, wrongly regarded formerly by the
author as for the internal carotid artery.

The choane are placed far forward. There is no masticatory ridge on the maxilla. Just
within the rim of the orbit there is a distinct suture which cuts off the lacrimal from the
prefrontal.

The lower jaw (fig. 81) presents a rather broad grinding surface.

The femora of this specimen are present. The total length is 107 mm. The head is
comprest. The plane passing through this head would come into contact with the tibial

~I
oo

Fics. 78 AND 79.—Chisternon hebraicum. Skull. x2. No. 5961 A. M.N. H.

78. Seen from above. fr, frontal; mx, maxilla; ma, nasal; pa, parietal; pro, prootic; sq, squamosal.
79. Seen from below. ju, jugal; mx, maxilla; pal, palatine; pt, pterygoid; qu, quadrate; qu. art, articulation
of lower jaw; Sy squamosal; vom, vomer.
border of the distal end of the bone. In Trachemys elegans this plane makes an angle of
re NG Aes Maat Salta see Signa =
perhaps 40° with the axis of the bone on the tibial side. The diameter of the shaft of the femur
of the species here described is 11 mm. The width of the distal end is 31 mm.

No. 5904 of the American Museum was also found at Grizzly Buttes. It is believed to
belong to the present species. It furnishes a large shell nearly complete, a portion of the skull
and lower jaw, the neck, the shoulder-girdle, and the complete pelvis. The carapace has an
axial length of 505 mm., anda maximum width of 470 mm. The carapace is moderately convex

go FOSSIL TURTLES OF NORTH AMERICA.

above and the bridges rise considerably above the bottom of the plastron. The outline of the
carapace is somewhat pointed in front and furnisht behind with rather shallow scallops.
In the midline behind is an excavation about 80 mm. wide. As in the other carapace the bones
are rather thin. The specimen has the characteristics pointed out by Cope as distinguishing
his Baéna hebraica, the presence of coarse grooves across the intercostal sutures and the high
marginal scutes over the bridges. The bones are thoroly co-ossified and no certain traces
can be seen of the suture between the nuchal and the preneural. The dermal sulci are mostly
distinct, but even these are obscure in the front of the carapace. The vertebrals are as in No.
5961. The marginal below the front of the first costal scute, probably the fourth, has a height
of about 35 mm.; two over the bridge have a height of 85 mm.

The plastron presents no novel features, its sutures and sulci being obscure.

The hinder portion of the skull is present, as well as the lower jaw. Its width behind is
gomm. The temporal roof extended backward somewhat further than in No. 5961, but this

pa i, r

Fics. 80 aND 81.—Chisternon hebratcum. No. Fic. 82.—Chisternon hebraicum.
5961 A. M.N.H. Fig.80, x}. Fig. 81, x4. x2. No. 5904 A. M.N. H.
8o. Skull from right side. Cond, occipital condyle; fr, End views of third, fourth, sixth, and
frontal; ju, jugal; /a, lacrimal; mx, maxilla; eighth cervical vertebre. On the right
na, nasal; pa, parietal; pmx, premaxilla; q]> side the anterior ends; on the left, the

quadra-tojugal; gu, quadrate; sq, squamosal. hinder ends.

may be due to greater age. Over the brain-case the bone is g mm. thick. The lower jaw is
nearly complete. From the tip to the middle of a line joining the hinder ends of the rami the
distance is about 60 mm. The symphysis measured about 20 mm. The triturating surfaces
are concave in both directions; their width, g mm. The coronoid process stood 23 mm. above
the lower border of the bone.

The neck had a length of 165 mm., about one-half of the length of the dorsal part of the
column (figs. 82, 83). The zygapophyses are high and not far removed from the midline.
There is a sharp crest on the lower midline of each centrum. The second and third are con-
vexo-concave; the fourth, biconcave; the fifth to the eighth, concavo-convex. The neural
arches appear to be co-ossified with the centra. Fig. 84 represents the scapula.

The pelvis is shown in figs. 85 and 86. The ilia, the ischia, the pubes, and the epipubic
process are all solidly co-ossifed. The expanded upper end of the ilium has a height of 52 mm.
and a width of 42 mm. ‘The posterior articular end of the centrum of the second sacral

BAENIDZ. gI

(fig. 87) has its upper half very little concave, while the lower half is slightly convex and uneven.
The anterior articular surface of the first caudal is decidedly concave, but not so much so as is
the hinder end.

On the upper surface of each xiphiplastron is a depression about 30 mm. long and half as
wide. The inner borders of the two are 55 mm. apart. The tuberosities of the ischia appear
not to have fitted into these depressions, for they are less than 55 mm. apart. From each of the

ve

—

‘Gs. 83-87.—Chisternon hebratcum. No.

5904 A. M. N. H.

83. Side view of all the cervical vertebra. The front
ends toward the left. 3.

84. Scapula. 4.

85. Pelvis, from right side. xh.

86. Pelvis, from below. 4.

87. Sacral vertebra and ribs. %.

tuberosities there projects backward a long pointed process that must have extended somewhat
behind the hinder border of the plastron. The lateral processes of the pubes rested on the
hypoplastra at points about 25 mm. inside the free borders of the hinder lobe.

Genus BOREMYS Lambe.
Boremys, LamBr, Ottawa Naturalist, x1x, 1906, p. 232.

Like Baéna, but having on each side supramarginal scutes, which alternate with the
costal scutes. Nuchal bone short and wide. A preneural present.

Type: Boremys pulchra Lambe.

Q2 FOSSIL TURTLES OF NORTH AMERICA.

Boremys pulchra Lambe.
Figs. 88, 89.

Baéna hatchert, Lambe, Geol. Sury. Canada, Contrib. to Canad. Paleont., 11 (4 to), pt. 2, 1902, p. 43,
hg. 8.

Baéna pulchra, Lampe, Ottawa Naturalist, x1x, 1906, p. 187, plate ini, fig. 4; pl. iv.

Boremys pulchra, Lampe, Ottawa Naturalist, XIx, 1906, p. 232.

The type of the present species belongs in the collection of the Geological Survey of Canada.
It, together with at least one other specimen, was collected by Mr. [eaeeeonee M. Lambe, of the
Survey, from beds belonging to the Belly River series, equivalent to the Judith River beds. The
locality is the mouth of ‘Berry Creek, on the Red Deer River, Alberta. The type consists of
the anterior half of the carapace and the complete plastron. The other specimen furnishes the
anterior portion of the carapace only. Through the kindness of the discoverer of the species the
writer has had the opportunity of examining it.

Fic. 88.—Boremys pulchra. Carapace of type. 4. From Lambe’s figure.
pren, preneural; sm, supramarginal scutes.

The specimen was originally referred to Baéna hatcheri tor the reasons that it was not then
generally accepted that the Judith River formation was distinct from the Laramie, that the
specimen is somewhat crusht, that it resembles in various ways B. hatcheri; and for the reason
finally that the presence of the supramarginals was then overlookt. The broader front of the
carapace was noted and caused some hesitation. The presence of the supramarginals and
the small preneural makes the separation of the species as the type of a new genus justifiable.

The type specimen was a rather small individual, having close to three-fifths the length of
the type of Baéna riparia and a little more than one-half that of B. hatcherz. The carapace
(fig. 88) had a length of about 195 mm. It is doubtful whether the width has been increast
by the crushing to which it was subjected.

The front of the carapace is considerably broader and more rounded than that of B.
hatcher1. The neurals, so far as preserved, appear to differ in no important respect. The
first appears to be transversely divided into two parts. The anterior portion is to be regarded
as a preneural, such as is seen in Chisternon. The shortness of the nuchal bone is remarkable.
Whereas, in B. hatcher: and other specimens of Baéna which reveal the sutures, the nuchal has
about the same fore-and-aft length as the first neural, in Boremys pulchra the nuchal is not
one-half as long as the neural. Its width is about 4 times its length.

BAENID. 93

The scutes in front of the first vertebral are more symmetrically arranged than in Baéna
hatcheri; but in Baéna and possibly in Boremys these scutes are subject to great variation.
The vertebrals are slightly longer than broad. In B. hatcheri they are much broader than long.
There is an accessory, or supernumerary, costal scute on each side of the first vertebral. In
species of Baéna one or both of these may be absent. The presence of large supramarginals
(fig. 88, sm) is surprising. In Macrochelys there are three or four of these on each side: but
these are comparable in size and position with the marginals. In Boremys pulchra, on the
contrary, the supramarginals are as long fore and aft as are the costals and alternate with them.

The plastron (fig. 89) has a length of about 172 mm. The anterior lobe is slightly narrower
than that of B. hatchert. The entoplastron is long and narrow. The bridge is somewhat
narrower relatively to the length of the plastron than in B. hatchert. The mesoplastra join
along the midline for a space of about 14 mm. The hinder lobe seems to differ little from that
of the species just mentioned. The intergulars are small and do not reach back on the ento-
plastron, thus differing from those of B. hatcher?.

/

Fic. 89.—Boremys pulchra. Plastron of type. 4. From Lambe’s figure.

Genus NEURANKYLUS Lambe.

A genus of uncertain position and known only from a portion of the carapace of the type
species. Eighth neural large, followed by an expanded suprapygal. In the type a ninth pair
of costal bones. The vertebral scutes nearly twice as wide as long.

Type: Neurank ylus exImius Lambe.

This genus is placed provisionally in the Baénide. When the last neural of Neurank ylus
eximius is compared with that of Baéna riparia they are seen to be very similar. The pre-
ceding neural in the latter species is elongated and appears to occupy the place of two neurals;
and it is possible that the sixth and seventh neurals of Lambe’s figures were consolidated. The
presence of the ninth pair of costals is probably an individual variation and of no classificatory
value, as suggested by the Yale specimen of Echmatemys wyomingensis (Leidy), which possesses
ten pairs of costals. The very broad vertebral scutes indicate that the genus is distinct
from Baéna. Mr. Lambe placed the genus provisionally among the Chelydride, but as no
genera of this family are known from deposits older than the Tertiary and as the type has some

O4 FOSSIL TURTLES OF NORTH AMERICA.

resemblances to the Baénide, which flourisht at that time, it seems better to refer Neurankylus
to this family until more 1s known about it.

Neurankylus eximius Lambe.
Neurankylus extmius, Lambe, Contrib. Canad. Palont., 1 (4 to), 1902, p. 42, fig. 7.

The remains on which this species was based were collected by Mr. Lawrence M. Lambe
in 1901, from Judith River deposits, Belly River series, on Red Deer River, Alberta. They
consist of the costals of the third pair; the right fourth; the left fifth, sixth, seventh, eighth,
and the supernumerary ninth; the most posterior neural; and the suprapygal. No peripheral
bones were secured. The individual appears to have had a carapace 360 mm. long. The
eighth neural is elongated and wider behind than in front. It articulates laterally with the

7 eo

Fic. go.—Neurankylus extmius. Hinder portion of carapace of type.
From Lambe’s figure. 4.

Ce P. 3, C+ ps 4, etc., costal plates; 1. 3, . 4, etc., neural plates; spy, suprapygal.

costals of the seventh, eighth, and ninth pairs. The posterior neural of Baéna riparia artic-
ulates with the seventh and eighth pairs of costals. The suprapygal of Neurankylus eximius
was probably followed by a pygal.

The vertebral scutes are relatively broad, the third being nearly twice as wide as long.
The sides are bracket-shaped. The costo-marginal sulci evidently ran along on the peripheral
bones. The costal scutes had relatively little height.

Mr. Lambe states that no very decided sculpture is shown on the surface of the bones.
Striations occur adjoining and at right angles with the sutures; elsewhere, especially near the
proximal ends of the costals, there is some roughness, produced by small, obscure, and irregular
depressions. On two of the costals there occur some comparatively large, concentrically
curved groove-like markings.

Genus THESCELUS nov.

Carapace with an enamel-like surface, which is sculptured into raised dots and lines, the
latter irregular in length and direction, with intervening pits and valleys. The front of the
carapace shortened and excavated in the midline; the rear somewhat pointed. The plastron
like that of Baéna. Bridges broad, extending far forward. The buttresses feebly developt.

Type: T hescelus insiliens H ay.

The bridges of the members of this genus extend far forward, so that the opening for the
head and fore legs is narrowed. The movements of the fore legs must have been a good deal

BAENID&. 95

restricted. On the other hand, the openings for the hind legs were large. It seems probable
that these turtles were nceiscomed to lying in the water in wait far passing victims and
leaping on them and seizing them. The hinder limbs were probably large and strong.

Quere alium, tua quem moyeant miracula, dixit
Thescelus; utque manu jaculum fatale parabat
Mittere, in hoc haesit signum de marmore gestu.
—Ovid, Met., V, 181.
Thescelus insiliens sp. nov.

Plates 24, 25.

The basis of this species is a specimen which was collected for the American Museum of
Natural History by Mr. Barnum Brown, in 1goo, in the Laramie beds of Wyoming. The
locality more accurately stated is on Seven Mile Creek, about 5 miles north of the Chey enne
River, and about 40 miles west of the town of Edgemont, South Dakota.

The specimen is a very complete one, presenting both the carapace and the plastron. The
carapace is in some parts, especially at the peripherals over the bridges, considerably fractured.
Very few parts are, however, missing, and the form and the general structure can be deter-
mined. Unfortunately, both the bone and the matrix filling ‘hes interior are very friable.

Traces of the sutures between the costals are present 2 and have been indicated in the figures.
It has been found impossible to determine the boundaries of the neurals. Faint traces of the
sutures have lead to the provisional delimitation of the nuchal bone. The first peripherals are
probably correctly represented. It is believed also that the sutures between the various bones
of the plastron are correctly determined, where indicated definitely. The form and extent of
the epiplastra and entoplastron are conjectural, as no traces of the sutures can be made out.

The form of this turtle is rather remarkable. Seen from above, the shell resembles that of
Caretta caretta. It is broad, not greatly elevated, with a median frontal excavation for the
neck, and narrowed behind. ‘The plastron peernbles greatly that of the species of Baéna.
It extends, however, far beyond the front of the carapace, while it fails equally as much to
reach the hinder border of the carapace. The bones are thin.

The length of the carapace (plate 24) in the midline is 397 mm. The first peripherals
extend 21 mm. in front of the bottom of the anterior excavation; thus the total length is 418 mm.
The greatest breadth, across the middle, is also 397 mm. The height above the plastron is
140 mm., but in life it has evidently been somewhat greater.

From the ends of the axis of greatest width the border of the carapace curves forward to
the anterior excavation. Passing backward from the axis referred to, the border is at first
very slightly concave to just behind the inguinal notches; then rather strongly convex for some
distance: then again rather strongly concave; at length convex to the midline behind. The
last concavity in ‘the border would be over the hind legs, when extended backward. Beyond
the sinuosities mentioned, there are no notches, scallops, nor indentations in the free borders of
the carapace. The edge of the shell just behind the inguinal notches appears to have been
somewhat flared upward; but this appearance may be Sie to some distortion.

In the hinder region of the carapace the peripherals are about 7 mm. thick and with acute
free borders. As the border of the carapace is followed forward, it becomes more obtuse. The
nuchal and the first peripherals are about g mm. thick. There are nowhere any carinz or
bosses on either the carapace or the plastron.

The whole surface of the carapace is covered with a hard, enamel-like layer, like that of
Compsemys, Glyptops, and Trionyx. The ornamentation consists of raised dots and lines.
The latter are sometimes straight, sometimes bent, or brancht, or anastomosing. The general
effect is that of shagreened leather. On each side of the sutures between the costals a band of
the surface is striated at right angles with the suture. It is from this striation, when present,
that the position of the sutures can be made out. Near the rear of the carapace there are such
indications of sutures as to justify the outlining of a suprapygal similar to that of G/yptops
plic atulus.

The anterior portion of the carapace is unusually short, the abbreviation being at the
expense of the first costals, the anterior peripherals, and the nuchal. The form and position
of the latter are indicated provisionally, but there seems to be sufficient evidence to show that

gb FOSSIL TURTLES OF NORTH AMERICA.

its antero-posterior extent was only about 30 mm. Were the anterior excavation not present,
the fore-and-aft extent of the nuchal would be about normal.

The first peripheral has a fore-and-aft extent of about 43 mm. Its length, parallel with the
border, can not be accurately determined; it was about 65 mm. From this specimen it can not
be learned where the sutures between the costal and the peripheral bones were situated, except
in the case of the first peripherals. However, since in both G/yptops and Baéna these sutures,
over the bridges, follow the sulci between the costal and marginal scutes, it is probable that
they do so in Thescelus. In Glyptops plicatulus, behind the bridges, the sutures rise a
considerable distance above the epidermal sulci; in Baéna emilia, a very little above. In
Thescelus insiliens the structure of the surface of the bone appears to indicate that behind the
bridges the sutures are placed somewhat above the scutal sulci, and they are accordingly so
represented provisionally.

The number and the extent of the peripherals along the border can not be made out with
certainty.

The epidermal scutes and their limits are for the most part determinable. The sulci are
narrow and shallow, but usually distinct. The first vertebral is 60 mm. long in the midline,
concave in front, behind, and on each side. The width behind is 75 mm., but in front it is
expanded to g8 mm. The next three vertebrals are from go mm. to 95 mm. wide. The exact
limit between the fourth and the fifth can not be determined. The fifth vertebral is 1romm. wide.

There seems to have been no nuchal scute. The first marginal on each side is very narrow,
8 mm. to 10 mm., and extends along the free border of the carapace 30 mm. The succeeding
marginals increase in height and length to the fourth, which is 55 mm. high and occupies
85 mm. of the free Border: The succeeding marginals retain this width to beyond the inguinal
notch; the posterior are much narrower. Tigers were probably paired supracaudal scutes.

The plastron (plate 25) has a median length of 420 mm. The anterior lobe has a length of
117 mm. The base is 170 mm. wide, but the lobe narrows forward so rapidly that at the
crossings of the gular sulci the width is only gt mm. The posterior lobe is 110 mm. long,
168 mm. wide at the base, and 130 mm. wide at the ends of the femoro-anal sulci. The
posterior end is broad, and occupied by a wide emargination 10 mm. deep.

The bridge is 194 mm. wide, fore and aft. From its inner end to the border of the carapace
is about 120 mm.

The sutures bounding the epiplastron and the entoplastron are not demonstrable; hence
they are represented provisionally. The thickness of the epiplastra is about 9 mm.

There are very broad mesoplastra extending across the plastron. The width of the outer
end of each bone is about 100 mm., being apparently a little greater on one side than on the
other. Where the bones meet at the midline they are 54 mm. wide. These mesoplastra differ
from those of G/yptops in being proportionally larger and in having their median ends narrower
than the outer. They are much like those of Baéna emilie.

The extent of the hy oplastra along the midline equals about 105 mm.; that of the hypo-
plastra 100 mm. The anterior borders of the xiphiplastra run straight across the plastron,
except near the border of the plastron, where they send forward on each side an angular
process into the hypoplastron. Just behind this process the xiphiplastron is 10 mm. thick;
near the hinder end, 6 mm.

The intergulars and gulars of this species are much like those of Baéna emilie. The
former, taken together, extend 30 mm. from side to side; 16 mm. fore and aft. The gulars are
very large, the sulci bounding them behind meeting the midline 54 mm. behind ine front of
the plastron, and diverging with an angle of aout 140°. If the entoplastron has been even
approximately defined, the humero- -pectoral sulcus falls far behind it. The fore-and-aft
extent of the humerals along the midline is 87 mm. The sulci between the pectorals and the
abdominals are deflected backward near the midline on each side. The pectorals occupy only
55 mm. of the midline. The femorals are 60 mm. fore and aft; the anals 72 mm. The femoro-
anal sulci are directed far forward as they approach the midline, exactly as in Baéna.

On the bridge there are 4 large inframarginals whose boundaries have been satisfactorily
determined.

The buttresses of the plastron are intermediate, in extent of development, between those of

Gly ptops and Baéna.

BAENIDA. 97

Thescelus rapiens sp. nov.
Figs. 91, 92.

This species is represented by a single shell, which was collected from Laramie deposits,
at Ojo Alamo, San Juan County, New Mexico, in 1g04, by Mr. Barnum Brown, of the
American Museum of Natural History. The catalog number of the specimen is 6066.
The shell has been damaged considerably by weathering, and lacks a portion of the carapace
in the nuchal region, some portions of the right costals, most of the peripherals, the front of the
plastron, and the rear of the xiphiplastrals.

The length of the carapace must have been close to 400 mm.; the width about 375 mm.
Apparently the shell was considerably deprest. The front of the carapace over the neck was
excavated, but not so deeply as in 7. msiliens. The area occupied by the vertebral scutes
presents a broad, shallow longitudinal channel; but in this, over the neural bones, there is a
low ridge. The free borders of the anterior peripherals are rather obtuse.

The sutures of the shell are obliterated, but a few of them may be traced by the fine stria-
tions which cross them. So far as they can be made out, they are shown in the diagrammatic

et Ss. of: aoa *. .Q2.
i 2% nw. as we EZ CS x

ne - /

/

\ a \
e a a \
NY \ \ /
= 1 Gon A S. /
Fics. gt AND g2.—Thescelus rapiens. Carapace and plastron. Type. Xt.
gi. Carapace. g2. Plastron.

figures. The scutal areas are distinctly markt on the shell. They present various irregularities.
The vertebrals (fg. g1) are broader than long; their dimensions are shown in the table
on page 08.

On the left side there is a supernumerary costal scute. his has been cut off mostly from
the first costal proper, but to some extent from the second marginal. The fourth marginal,
shown on the left side, has a height of 57 mm., rising somewhat on the costals.

The plastron (fig. 92) is large. From a low ridge which joins the free border of the front
lobe with that of the hinder lobe the bridges ascend at an angle with the remainder of the
plastron. The axillary notch is far forward, falling about 55 mm. behind the front of the
carapace. The opening for the head and Jegs is thus considerably restricted. The front lobe
extended evidently much beyond the front of the carapace. Its length can not be determined.

i

gs FOSSIL TURTLES OF NORTH AMERICA.

The width of the base is 150 mm. The bridge is 167 mm. wide The length of the hinder lobe
was approximately 100 mm.; the width at the base is 165 mm. It narrows rather rapidly
backward, so that at the femoro-anal sulcus the width 1s 104 mm.

There are present large mesoplastra, the boundaries of which can be pretty satisfactorily
determined. These are about 35 mm. wide at the midline, but they expand to about 85 mm.
at the peripherals.

The median longitudinal sulcus runs a very irregular course, and across the femorals it
can not be distinguisht with certainty. The erieale occupy 70 mm. of the midline; the
pectorals, about g0 mm.; the abdominals, about 35 mm.; the
femorals, about 52mm. The femoro-anal sulcus runs far forward
from its starting point on the border of the plastron. Probably on
account of weathering, the sculpture of the carapace is nearly

Vertebral. Length. Width.

(ea | 82+ Q B : r a - ake
! ae iP obliterated, appearing only in a few spots. On the plastron it 1s
2 7 | 2 . . = = a o ome
3 Sele Ge more distinct. It appears to have resembled that of T. insiliens
4 61 9 and consists of narrow and low ridges and tubercles. Some traces
5 os 36

are observed of the ridges due to the growth of the scutes.

This species differs from J. imsiliens in having the nuchal
less deeply excavated, in having a median depression along the back, and in having the hinder
lobe of the plastron more rapidly reduced in width backward. In T. insiliens the bridges are
considerably wider than the base of the hinder lobe.

Genus CHARITEMYS nov.

A genus of Baénide. So far as known like Thescelus, but with the axillary buttresses
ascending to near the neural borders of the first costals. Inguinal buttresses probably ascend-
ing on inner surfaces of the fifth and sixth costals, but not to so great a height as did the axillary
buttresses.

Type: Charitemys captans Hay.

Charitemys captans sp. nov.

Text-figs. 93-95.

The type of the present species is No. 6098 of the American Museum of Natural His-
tory. It forms a part of the Cope collection of fossil reptiles and was collected in 1876, by
Messrs. Sternberg and Isaac, in the Judith River deposits of Montana. There are present
considerable parts of both the carapace and the plastron, but unfortunately important parts
are missing.

In size this species appears to have been somewhat smaller than the type of T hescelus

insiliens, judging from the plastral bones, but of the same size, if we judge from the widths of

6 costal bones.

Of neurals there are portions of only two. One of these, probably the eighth, has a width
of 44 mm. Its length can not be determined, what is regarded as the posterior end being
broken away. On fhe supposed anterior end 1s a scunaedn carina. ‘The broader end is crost
bya sulcus, probably that between the fourth and the fifth vertebral scutes. On the under side
are three impressions for three neural spines. The other neural is only 30 mm. wide. It
probably belonged near the beginning of the series.

Of the costals there are present the proximal end of the first of the left side, the right
second, third, and sixth, and the left fourth, fifth, sixth, and seventh. Fig. 93 represents the
second and third right costals; fig. g4, the fourth to the seventh of the left side. Of the latter
three, more or less of the distal ends are missing. The supposed first presents difhculties.
On the upper surface are found portions of the first and second scute areas and of the first
costal area. The area of the first vertebral scute on this costal is only 16 mm. wide. The
whole width of this scute could hardly have exceeded 65 mm. On the lower side is a large tri-
angular articular scar for the axillary buttress of the plastron. This approacht aitan 21
mm. of the neural border of the costal. Between the scar and the neural border is a sharp
ridge from which appears to have been broken the rib-head of the costal. This was much
slenderer than those of the succeeding costals. The slenderness of this rib-head was hardly to

BAENIDZ. 99

have been expected. There is present a portion of one plastral buttress, the length of which is
72 mm.; but this has the appearance of being the inguinal buttress.

The second costal (fig. 93) has a length of 142 mm., a width of 54 mm. at the costo-vertebral
sulcus, and of 60 mm. at the distal end. The proximal end is crost by the sulcus bounding
laterally the second vertebral. This had a width of about 110 mm. Anteriorly it narrowed
considerably. Its anterior end occupied only 18 mm. on the first costal plate. The distal end
of the costal is crost by the costo-marginal sulci, a condition showing that the fourth and fifth
marginal scutes overlapt on the costal bone.

The third costal plate (fg. 93) is slightly narrower than the second at the proximal end and
wider than the latter at the distal end. The fifth and sixth marginal scutes overlapt slightly
on the distal end. The proximal end was occupied by a part of the second and a small part of
the third vertebral scutes. The fourth left costal (fig. 94) is 48 mm. wide at the costo-vertebral
sulcus; 66 mm. at the distal end. That portion of the third vertebral scute on the proximal
end of this costal is 48 mm. wide. The costo-marginal sulcus skirts along the distal end of the

Fics. 93-95.—Charitemys captans. Costal bones and plastron of type. 4.

g3- Second and third right costals, the second on the right. 94. Fourth to seventh costals of left side.
95. Plastron considerably restored.

bone. The fourth and fifth costals are each 45 mm. wide. Of the seventh there is present a
fragment 46 mm. long and 31 mm. wide at the sulcus. The rib-heads of the fifth and sixth
costals have a diameter of about 6 mm. No trace of the articulation for the inguinal buttress
appears on the parts preserved of the fifth and sixth costals. It is evident, therefore, that this
buttress did not ascend to as high a point as did the axillary. From the form of the sutural
border of the supposed inguinal buttress it is believed that the latter was articulated to the
fifth and sixth at their junction.

Of the plastron (fig. g5) there are present a fragment of the left epiplastron, a large part
of the right hyoplastron, the left hypoplastron, and a portion of the free border of the right
xiphiplastron. These are represented in the diagrammatic figure.

That this turtle possest a mesoplastron is evident; otherwise, the bridges would have been
only about 100 mm. wide, about one-half as wide as the costals spanned by the two buttresses
of one side. No part of the mesoplastrals appears to be included among the bones present.
Their antero-posterior width ts only conjectural,

100 FOSSIL TURTLES OF NORTH AMERICA.

The piece of epiplastron present is g mm. thick. The gulo-humeral sulcus crosses the
hinder end as in Gly ptops and Baéna.

The length of the hyoplastron, from the epiplastral suture to the mesoplastron, is 120 mm.
The width of the anterior lobe was about 142 mm. The distance from the axillary notch to
the mesoplastron measured yery close to 50mm. ‘The thickness of the bone at the entoplastral
suture is 6mm. The free border in front of the axillary notch is subacute. Most of the border
which rose to meet the peripherals is broken away. A portion of the sulcus between the
abdominal scute and the anterior inframarginal is present.

The length of the hypoplastral at the midline is go mm.; the width at the base of the
hinder lobe, 80 mm.; the width from the midline to the union with the bridge peripherals,
130 mm. A portion of the outer end of the bone is missing, but a section of the sulcus is seen
starting forward from the inguinal notch and section of another sulcus between the hinder
inframarginal and the contiguous marginals. The hinder inframarginal has a width of about
45mm. Its anterior end appears to have extended on the mesoplastron.

The fragment of xiphiplastral is 53 mm. long. It shows the free border. This is subacute,
and from it the bone thickens soon to 10 mm. No portion of the upper surface was covered
with scutes. On the lower surface the femoro-anal sulcus crost the bone about 30 mm. behind
the suture with the hypoplastron. The form of the hinder border of the lobe can not be
determined.

Of the skull there is present the pedicel of the left quadrate. The condyle for the lower
jaw is concave, 11 mm. from side to side, and less than 5 mm. antero-posteriorly. At the inner
side of this condyle there ascends toward the lower end of the parietal plate a sharp ridge. The
rough surface for the pterygoid lacks 8 mm. of reaching the condyle, a fact that enone that
hit genus did not belong to the Pleurodira.

The upper surface of the carapace was more or less uneven, especially along the midline.
All the articular borders of the bones are striated perpendicularly to the sutures. Besides this,
there is a delicate pitting of the surface which gives the effect of leather. The lower halves
of the costals are markt by coarse ridges, which have been produced during the growth of the
costal scutes.

The plastral bones have all the sutures conspicuously markt by striz, which run at right
angles with the sutures. The whole surface is occupied by a fine network of delicate ince

Genus POLYTHORAX Cope.

An insufficiently known genus of uncertain position. Plastron suturally united with the
carapace; furnisht with the usual scutes, besides intergulars and interhumerals. Lower jaw
with narrow ramus; the triturating surface bounded outwardly by a sharp margin; the
symphysis short.

Type: Polythorax missuriens1s Cope.

This genus is arranged provisionally among the Baénida; but it is probable that it and
Archeochelys Lydekker belong to a distinct family.

Polythorax missuriensis Cope.

Polythorax mussurirensts, Cope, Proc. Acad. Nat. Sci. Phila. 1876, p. 258; Bull. U. S. Geol. and Geog.
Surv. Terrs., 111, 1877, p. 573.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, < 438.—HatTcHER,
Bull. U. S. Geol. Surv. 257, 1905, p. 77.

It is not at present known what has become of the type of this species. It was found in the
Judith River deposits of Montana, in 1876. The plastron appears to have been pretty complete,
but we are not told how much of the carapace was secured. No part of the species has ever
been figured.

The plastron had a total length of 183 mm.; hence the individual was not a large one,
perhaps attaining about the size of our Trachemys elegans. The anterior lobe had a length of
49 mm. The bridge was 76 mm. wide and as long. ‘The anterior lobe is stated to have been
narrower at the base than the bridge. We must eoreline therefore that this lobe was not one-
third as wide as the carapace. Its anterior extremity was rounded. The width of the base of

BAENID. IOI

the hinder lobe is not given, but its posterior extremity was 35 mm. wide, truncated, and
with rounded angles. It was shorter than the anterior lobe. Its thickness in the inguinal
region was 10 mm.

The surface of the plastron was obsoletely, but coarsely, rugose; roughest in front, where
the sculpture consisted of short, raised lines irregularly disposed.

The intergulars were distinct. These were followed by a pair of interhumerals, which were
longer than ide and crowded the humerals away from each other, and they seem to have
extended themselves backward between the pectorals likewise. The pectoro-humeral sulcus
appears to have been advanced well forward. Cope states that it was impossible to determine
whether or not “intermarginal” scutes were present, and that if they existed their position was
quite external. It is probable that by “intermarginals”” was meant inframarginals.

The carapace is stated to have possest an openly dentate posterior horden The surface
was irregularly swollen, especially along the margins of the vertebral scutes. The latter were
wide; the marginals are said to be narrow, by which is probably meant that they rose but a
short distance from the free margins.

The description of this species given by Cope indicates that it was related to Baéna rather
than to Adocus. The thoro co-ossification of the bones, so that the presence of mesoplastrals
could not be proved or disproved, the uneven surfaces of the shell, the notcht border of the
carapace, all point toward Baéna. At the same time, the presence of the interhumerals
marks it off as different from all North American turtles hitherto described. Archeochel ys
(Lydekker, Cat. Foss. Rept., pt. 11, 1889, p. 219), from the Wealden of England, has the
humerals separated by what has been regarded as an intergular, but which is quite as likely
an interhumeral. Behind this come in succession an interpectoral, an interabdominal,
and an interfemoral. The latter extends itself backward between the anals also. That is, the
scutes which usually join in pairs along the median line are here separated the length of the
plastron by a series supposed to be azygous. These median scutes in both Polythorax and
Archeoc helys are probably homologous win the median series of Dermochelys. ;

Mr. Lydekker places his genus 5 provisionally i in the Amphichelydia.

Genus NAOMICHELYS nov.

A genus known only from the entoplastron. Outer surface ornamented with elevations
resembling small shot. A long narrow scute (intergular or interhumeral) occupies most of the
length of the bone. Gulars ? and humerals? present.

Type: Naomichelys speciosa Hay.

The relationships of this genus are not certain. It may belong among the Pleurosternidz
rather than among the Baénide. It is here put in the vicinity of Polythorax.

Naomichelys speciosa sp. nov.

Plate 40, figs. 2, 3.

The only portion of this species at present known is an entoplastron which was collected
in 1904, by Mr. Barnum Brown, of the American Museum of Natural History. It was secured
in the Upper Jurassic, Morrison beds, 25 miles east of Pryor, Montana. The catalog number
is 6136. The bone is complete, except that the extreme anterior end is broken away. The bone
is 85 mm. long, and was originally about 10 mm. longer. The width is 78 mm. The thickness
is quite uniformly close to 7 mm. Where the bone joined the epinlastia the upper surtace
extends out a little farther than the lower. The hyoplastrals overlapt extensively the ento-
plastron, as may be seen from plate 42, fig. 3. Fig. 2 of the same plate shows the scutes and
the ornamentation of the inferior surface. Five scutes are represented in the bone. There
is a long median scute which narrows forward, as well as backward. It seems probable that
anteriorly i it did not extend beyond the bone. This scute may be the intergular which was
crowded backward by the eulars as in GC lokagi noveguinee (Boulenger, Cat. Chelonians,

pl. vi), or it is possibly an interhumeral « ran interpectoral. Attention is called to Cope’s
Polythorax and Lydekker’s Archeochelys.
On each side of the scute just described is another which may be either an intergular or a

gular. Behind this is a large scute which is assumed to be the humeral.

[O02 FOSSIL TURTLES OF NORTH AMERICA.

The surtace of the bone is covered with rounded elevations which resemble small bird shot.
There are about eight in a line 10 mm. long. The basis of each elevation is often of less
diameter than the body of it. Many of them are broken off near the surface of the bone,
leaving circular scars. Along the edges of the bone which joined the hyoplastra there is a
narrow border nearly free from the pustules.

This turtle differed from Polythorax missuriensis in the character of the ornamentation,
this consisting in the latter species of short raised lines. In that species, too, the pectoro-
humeral sulcus appears to have been pushed well forward. In the species here described
there is no trace of the presence of this scute.

Superfamily PLEURODIRA Cope.

Thecophorous turtles having a carapace composed of costals and peripheral bones and
usually a series of neurals and a plastron in which the epiplastra are in contact with the hyo-
plastra. Mesoplastra present or absent. Intergular scutes developt, the inframarginals
wanting. Temporal roof of the skull varying from nearly complete to nearly obsolete. Ptery-
goids not extending backward between the quadrates and the basisphenoid; broad, with the
outer border uprolled. Neck bending sideways; not capable of being withdrawn between the
scapula. Ilia suturally joined to the eighth costals; the pubes and the ischia, to the xiphi-
plastra.

The living Pleurodira are divided by Boulenger into 2 families, the Pelomedusidz and the
Chelydidz. About 30 species are known. None of these have had the anterior limbs trans-
formed into flippers, like those of the Chelonude. The geographical distribution of the living
species is illustrated by fig. 15, on page 34. The earliest turtles certainly known to belong to
this superfamily occur in the Upper Cretaceous of North America. Cope referred these to the
Pelomeduside; but the present writer, following Baur, accepts for them the family Bothremy-
dida. So far as is known, no species of the superfamily lived in North America after the end

of the Upper Cretaceous.
Family BOTHREMYDID Baur.

Extinct pleurodire turtles having the skull probably extensively rooft over in the temporal
region. Vomer present. Triturating surfaces of the jaws, upper and lower, broad and deeply
excavated. Shell as in the Pelomedusidz, with small mesoplastra.

Baur was the author who proposed this family, making it include Bothremys and T aphro-
sphys. Cope had arranged these genera under the Podocnemidida. To the present writer
it appears that the presence of a vomer, but still more the extraordinary excavations found
in the jaws, upper and lower, are sufficient to set off Bothremys as a member of a distinct family.
With it must go for the present T aphrosphys.

Kry To THE GENERA.
A. Known from skull only:

Each side of jaws, upper and lower, with a deep pit. : : Bothremys
AA. Known from shell only:

1. Nuchal bone not shortened; free borders of peripherals acute : .. Taphrosphys

2. Nuchal short and broad; free borders of peripheral obtuse ; aa Ambly peza

3. Only the xiphiplastron known; the ischiadic scar extending to the midline. . .. . Natadochel ys

Genus BOTHREMYS Leidy.

Vomer well developt, not separating the palatines. Choane behind the centers of the
orbits. The nasal passages underfloored by the surrounding bones. Crushing surfaces of jaws
broad and occupying portions of the manillz and of the palatines; the excavation contracting
to a pit in each. Lower jaw with the dentaries co-ossified. Shell unknown.

Type: Bothremys cook: Leidy.

It has been suspected that the skull represented by the type of Bothremys is that of some
species of Taphrosphys, all the species of which are known only from shells. This is entirely
possible, but nothing is to be gained at present by reducing Taphrosphys to a synonym otf
Bothremys.

BOTHREMYDID&. IO

oe

Bothremys cooki Leidy.
Plate 23, figs. 2, 3; text-figs. 96, 97.

Bothremys cookt, Lrivy, Smithson. Contrib. Knowl., xrv, art. v1, 1865, pp. 10, 120, plate xviii, figs.
4-8.—Copr, Cook’s Geol. New Jersey, 1868 (1869), p- 735; Amer. Naturalist, 111, 1869, p. 89;
Ext. Batrach., Reptilia, Aves N. A., 1870, p. 1573; Vert. Cret. Form. West, 1875, p. 263.—Maack,
Palaontograph., XVIII, 1869, p. 280.—Baur, Ann. and Mag. Nat. Hist. (6), Iv, 1889, p. 38.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438.

The skull which has furnisht all that we know of this species 1s a most extraordinary one.
It was found in the lower bed of greensand, belonging to the upper Cretaceous, near Barnes-
boro, Gloucester County, New Jersey, and is now in the geological collection of Rutger’s
College, New Brunswick, New Jersey, where the writer has been permitted to examine it. It
was fully described and figured by Leidy in his original description. His figures are stated
to be of the size of nature, but they are really somewhat reduced. Plate 23, figs. 2, 3, of the
present work is reproduced from drawings belonging to the U.S. Geological Survey. These
were prepared in 1888 for Dr. George Baur, who was then preparing to monograph the fossil
turtles. The one showing the lower surface of the skull differs from that of Dr. Leidy in
indicating the positions of the sutures. It will be observed that in this drawing the missing
quadrate regions are restored in outline.

The skull, from the tip of the snout to the occipital condyle, had originally a length of
close to 70 mm. The width at the hinder end of the maxilla is 7omm. From the latter point

Fics. 96 AND 97.—Bothremys cookr. Skull of type.

96. Seen from above. 97. Seen from right side.

the outline of the skull rounds rapidly to near the end of the snout. Just before this is reachr
the curves change somewhat, so that the snout is slightly prolonged. The skull is flat above
(text-figs. 96, 97) there being a slight descent from the orbits forward. The interorbital
space 1s 17 mm. wide. The eyes lookt strongly upward. Both diameters of the orbits
measure 14 mm. From the upper borders of the orbits the sides of the face sloped downward
and outward with a moderate curvature. The outline of the upper jaw, seen from the side,
is very convex. The nasals are absent. Whether or not the temporal region was widely
rooft over is uncertain, but it is probable that such was the case.

A view of the lower surface of the skull shows many interesting features. “Phe premaxille
are large, extending backward a distance of 18 mm. Behind these comes the well-developt
vomer, which presents feeble palatine plates, to aid in underflooring the nasal passages.
The length of the vomer as seen from below is 15 mm. It lacks much of reaching the
pterygoids. The palatines meet the vomer in advance of the choane. The anterior borders of
the choane are placed 24 mm. behind the tip of the snout. These choanz lie in a vaulted
excavation, which, beginning on the premaxilla and expanding backward, reaches to the post-
palatine foramina, being shallow in front of the choanz. The excavation is bounded on each
side by a prominent tootht ridge, the inner boundary of the triturating surface of the jaw.
The pterygoids meet along the midline a distance of only 7 mm. As in the Pleurodira gener-

104 FOSSIL TURTLES OF NORTH AMERICA.

ally, the pterygoids are wide, and the outer border is uprolled in a scroll-like manner. The
basisphenoid, most of which is present, is large, the width being 13 mm.

The most striking feature of the skull is presented by the triturating surfaces of the upper
jaws. On the premaxilla they are very narrow. Backward each expands rapidly and occupies
most of both the maxilla and the palatine. The greatest width is 24 mm. Each, instead of
being flat, is deeply excavated. At the suture between the maxilla and the palatine the exca-
vation contracts into a circular pit which rises in the maxilla to the height of the floor of the
orbit. The walls inclosing this pit are smooth. The remainder of the triturating surface is
perforated by openings for blood-vessels.

The lower jaw shows little else than the co-ossified dentaries. “These are of very solid
construction. ‘The jaw as a whole is thin and pointed in front, but the coronoid processes rise
toa height of 27 mm. The sy mphysis has a length of 20 mm. The triturating surfaces are as
pcracricaple as those of the upper jaw. Each may be described as containing a deep pit,
situated at the hinder end of the dentary and opening forward and upward, trumpet-like, on
the upper surface of the dentary. The trumpet-shaped mouth extends forward to near the tip
of the jaw. It is bounded outwardly by the cutting-edge of the J jaw; inwardly by a ridge, which
rising at the tip of the jaw, runs backward and upward, increasing in height to the coroner’
process, along the inner border of the ramus.

The purpose of the pit-like excavations in the jaws, upper and lower, is problematical.
In speaking of the pit in the upper jaw Leidy said that it did not appear like an alveolus for a
tooth, but that it may have accommodated a corneous tooth-like process springing from the
corresponding hollow of the lower j jaw. Baur thought that the pits lookt much like the alveoli
of large tusk-like teeth.

It does not appear probable that there were any teeth in this turtle. It seems far more
probable that both jaws were covered with plates of horn, as are those of all other known
turtles. The whole construction of the skull of Bothremys indicates that it was accustomed to
crush hard objects as food. Probably these objects were of such a nature that economy of
force demanded that they should be brought to a particular spot on the jaw for crushing. To
provide for the rapid reproduction of the horn beneath these areas for crushing, these pits
became developt in a way analogous to the human “‘nail-bed.”

Genus TAPHROSPHYS Cope.
Prochonias Cope.

A genus of pleurodirid turtles known only from the shell. Carapace with 7 neurals, the
costals of the seventh and eighth pairs meeting their fellows at the midline; a large suprapygal;
and 11 pairs of peripherals, the posterior thin and with acute free borders. No nuchal scute.
Plastron with 11 bones, the mesoplastrals small and well out on the bridges. A single intergular
almost wholly confined to the entoplastron. Hinder lobe with large notch. Large pits in the
first and the fifth costals for the axillary and inguinal buttresses. Ilium firmly articulated with
the carapace at the junction of the seventh and eighth costals. Ischium and pubis articulated
to the xiphiplastron.

Type: Platemys sulcatus Leidy.

In Cook’s Geology of New Jersey, 1868 (1869), page 735, Cope mentions the generic name
Taphrosphys in connection with 3 specific names, as follows: J. molops, T. princeps, and
T. sulcatus, The first two had not yet been described, the last was Leidy’s Platemys sulcatus.
In the April (1869) number of the American Naturalist, Cope again mentions the name
Taphrosphys, this time in connection with molops only, while to the new genus, Prochontas,
were referred the species P. sulcatus, P. strenuus, and P. princeps. Of these again none had
yet been described except P. sulcatus (Leidy). The latter therefore is the type both of
Taphrosphys and Prochonias. Which of these names has precedence depends on which was
issued first to the public, the April number of the American Naturalist or Cook’s Geology of
New Jersey. Investigations not wholly satisfactory seem to show that the latter was first
publisht, probably some time about the first of March, 1869. This conclusion enables us to

BOTHREMYDID&. 105

retain the name to which Cope finally referred all the species named above and some others.
In his monograph of 1869 and 1870, he described all his species and made Prochonias a
subgenus of Taphrosphys. Here T. molops was regarded as the type of T aphros phys.

All the species known to belong to this genus are represented by fragmentary individuals,
but these furnish us the means of obtaining a pretty clear idea of the structure of the carapace
and the plastron. Nothing is known regarding the skull, unless it be that the skull known as
Bothremys cook: belongs to a species generically identical with Taphrosphys. Of the limbs
extremely little is known. Evidently the genus belonged to the Pleurodira and was not far
removed from Podocnemis. There were 8 pairs of costal bones, the last two pairs meeting on
the midline. The nuchal bone is large and expanded behind. There were seven neurals, the
first large, the last small. There were 11 pairs of peripherals, a suprapypal and a pygal. The
peripherals of the hinder part of the carapace were thin and acute. Those of the anterior
portion of the bridge, the fourth and fifth, appear to have had the free border thickened and
rounded or with faces at right angles; while those succeeding them had the free borders acute
and the faces, upper and lower, meeting at an angle less than right.

On the inferior side of the first costal was a deep pit for the reception of the axillary buttress;
on the fifth was another pit for the inguinal buttress. An extensive excavation, partly in
the seventh costal and partly in the eighth, received the upper end of the ilium. This excava-
tion occupied more than a half of the length of these costals.

The upper surface of the carapacial bones is markt by irregular grooves, which anastomose
more or less and divide it into areas differing in size and form in the different species and on
different parts of the same individual. The sulci are shallow and sometimes obscure. Evi-
dently, the epidermis was thin. There was no nuchal scute. The vertebrals were rather
broad. The marginals did not overlap on the costal bones.

The plastron was well developt, but the anterior lobe was short and broad, and rounded.
Strong buttresses rose from the plastron to articulate with the carapace. On the xiphiplastrals
were well-developt articulatory surfaces for union with the ischia and the pubes. The posterior
notch was large and rounded. As stated by Cope, and as shown by the borders of various
hyoplastra and hypoplastra, there were small triangular mesoplastra, which occupied each a
position on its bridge. The free borders of the anterior lobe were mostly obtuse; those of the
hinder lobe were mostly acute. The inferior surface is sculptured like the carapace; but
often the markings are obscure. The scutes of the anterior lobe are not all satisfactorily
determined. There was a large intergular that occupied a considerable part of the entoplastron.
Apparently, as shown in the figure of the anterior lobe of 7. molops (fig. 116), this was bounded
in front by a sulcus across the entoplastron, thus permitting the gulars to meet each other at the
midline. It is possible that the intergular extends to the front of the lobe, as represented in
fig. 106, and that the gulars do not join each other. The humerals lie on the outer ends of the
epiplastra, overlapping on the hyoplastra. The arrangement of the other plastral scutes may be
seen from the figures. Those on the bridges are not known.

A‘. Species with shell having an even surface, except that it bears a network of vascular grooves.
a‘. Surface of shell usually with a close network of rather broad grooves.
1. A large species with bones of moderate thickness; the fourth vertebral scute

nearly a half wider than long......... a apeidiceatevin cha Aaa ne ee sulcatus
2. A species of moderate size; second and fourth vertebral scutes little wider

EN aMMlON Gry weteyc sia Seale niga osetia seer eee Sores aaa doe = longinuchus
3. Asmall species with thin bones; second vertebral scute twice as wide as long;

the fourth probably as wide as the second...................0.0e eee eees leslianus
4. A large species with thick bones; front of plastron broad, truncated, or concave
: on each side of the thickened epiplastral symphysis...... : Lote esses. Strenuus
5. A large species with bones of moderate thickness; front of plastron rounded;

the first and third vertebral scutes about one-half wider than long..... .. molops

a’. Surface with thread-like grooves which form large meshes.
A large species with thick bones; entoplastron broader than long, its postero-
lateral sides excavated..................... Bee ene te er cote dares
A’. Surface of shell coarsely sculptured like that of the Trionychidz..... i -..... nodosus

106 FOSSIL TURTLES OF NORTH AMERICA.

Taphrosphys sulcatus Leidy.
Text-figs. 98-100.

Platemys sulcatus, Letpy, Proc. Acad. Nat. Sci. Phila., vit, 1856, p. 303; Smithson. Contrib. Knowl.,
XIV, art. vI, 1865, pp. 109, 120, plate xix, fg. 4—Maack, Paleontographica, xvii, 1869, p. 281.

Taphrosphys sulcatus, Cope, Cook’s Geol. New Jersey, 1868 (1869), p. 735; Ext. Batrach., Reptilia,
Aves N. A., 1870, pp. 159, 164, text-figs., 45, 45 brs; Vert. Cret. Form. West, 1875, p. 264.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 4309.

Prochontas sulcatus, Cope, Amer. Naturalist, 111, 1869, pp. 89, 90; Ext. Batrach., etc., p. 165, line 8,
plate Xl, hg. zi

As has occurred too often in the history of paleontology, the present species was based on
very meager materials. These consisted of 3 peripheral bones, regarded as the fifth, sixth, and
seventh, and a xiphiplastral. Only the peripherals were figured. einer were large, measuring
altogether 8 inches along the free border. They came from the Cretaceous greensand at Tinton
Falls, Monmouth County, New Jersey, and are preserved in the geological collection of Rutgers
College, New Brunswick, New Jersey. Leidy’s description of these bones is very brief. Each
bone hae two faces, an upper and a lower, the lower broad and flat, the upper inclining toward
it at an angle of nearly 45°, the two meeting along an acute margin. The fifth is 54 mm. long on

-F

Fics. 98 AND 99-—T aphros phys sulcatus. No. 1468 A. M.N. H.

g8. Section of seventh peripheral of type. 99. Rear of carapace. X}.

we

the free border; the sixth, 60 mm.; the seventh, 76 mm. The sixth rises from the free border to
the costal border, 69 mm.; the seventh, 70 mm. The anterior end of the seventh is much thick-
ened and has afforded an articulation with the inguinal buttress. In front of this articulation
the bone is somewhat excavated by the sternal chamber. The hinder end of this peripheral is
thin, not exceeding 14 mm. (hg. 98). The free borders of all these peripherals are acute.
The superior surface ts Scnamented by a close articulation of grooves. Fig. 98 represents a
section along the sulcus between the marginal scutes that overlapt this bone: The piece of
xiphiplastron displayed the scar for union with the pelvis.

With this species Cope identified a specimen which he obtained from the upper greensand
bed at Barnesboro, Gloucester County, New Jersey. This specimen furnisht him the three
hinder pairs of costal plates, the suprapygal, the pygal, and a number of the hinder peripherals.
There are present also portions of two bridge peripherals and some fragments of other costals.
There appears to be no reason for doubting the correctness of Cope’s identification. This
specimen (figs. gg, 100) is now in the American Museum and has the catalog number 1468.
It now lacks all the peripherals that Cope figured, except one. According to his figure, Cope
lackt the eleventh peripheral. The one now present was certainly in Cope’s hands, having
his marks on it; and yet, after careful examination, that bone is found to fit in the place of the

BOTHREMYDID&. 107

right eleventh peripheral and nowhere else. With it is connected a portion of the pygal. The
proximal half of the left sixth costal is now missing. On the other hand, the distal end of the
right seventh costal has been found and included in the figure.

The individual was a large one, the length of the carapace being estimated at 650 mm.
Cope states that his figure is one-third the Gaaial size, but in reality it is in width only a little
more than twenty-two hundredths of the original. As regards the length of his figure, it is
much foreshortened.

As in the other species, the costals of the last two pairs (fig. 99) meet at the midline. The
eighth neural was not developt and the seventh was short. The sixth costals are 66 mm. wide
at their distal ends; the seventh, 70 mm., the eighth, 54 mm. The sixth is g mm. thick where
it joined the neural; 5 mm. at the distal end.

The suprapygal, described by Cope under the name of pygal, is triangular, pointed above,
83 mm. long and 99 mm. wide behind. The eleventh peripheral measures 72 mm. along the free
border and is 65 mm. high. The free edge is acute. It is slightly thicker at the hinder end than
in front, being 10 mm. posteriorly.

Fragments of two bridge peripherals are present. One, probably belonging near the
hinder end of the bridge, has the two faces meeting with an angle of about 50 degrees between

Fic. 100.—T aphros phys sulcatus. Under side of rear of carapace. >

“~

No. 1468 A. M. N. H.

AA, excavated area for ilium; x, sacral rib.

them at one end, probably the anterior. At the other end the faces meet at an angle of about
30 mm., the free border being acute. The other fragment has the two faces meeting at an angle
of about go°. This bone probably belonged near the front end of the bridge.

As Cope states, the sculpture of the upper surface of the carapace is coarsely reticulate,
tending to enclose areas longitudinal with the costals toward their middle and distal portions,
while that of the peripherals is closer. The sulci are shallow and narrow. The fourth vertebral
scute was about 110 mm. long and 154 mm. wide; the fifth was 110 mm. long, 162 mm. wide,
only 50 mm. anteriorly. Its lateral extremities are sharply angled. The costo-marginal sulci,
so far as they are represented, are confined to the peripherals.

On the inferior surface of the carapace (fg. 100) we find, excavated partly in the seventh,
partly in the eighth costals, a large pit, 78 mm. long and 28 mm. wide, for the reception of the
upper end of the ilium. The pit is bounded anteriorly by a sharp ridge proceeding from the
tib-head of the seventh costal. This ridge is highest at the upper end, lowest in the middle.
Behind, the pit is bounded by a low rough ridge running along the middle of the eighth costal.
Both the costals are much thickened at the lower end of the pit. The upper end of the pit is
inclosed in front by a low ridge derived from the base of the rib-head of each costal; behind,
by a distinct squarish bone, which is to be regarded as the tenth dorsal rib, corresponding to the

108 FOSSIL TURTLES OF NORTH AMERICA.

enlarged extremity of the tenth dorsal rib of the Cryptodira. On its hinder angle is a broken
process, apparently the base of the rib-head. The distal end of this bone abutted squarely
against the ium. Behind this squarish bone is an irregular and rough excavation in the
eighth costal, which seems to have received another bone, probably the first sacral rib. Behind
dhe rough surface just mentioned 1s another, lying partly on the anterior border of the suprapy-
gal; and this may have supported the second cage rib, not yet lost in these early Pleurodira.

On the contiguous ends of the seventh and the eighth costals, in the midline, are 3 rough
articular surfaces which were in contact with the nena arches of three vertebra. Cope speaks
of these as having been in contact with “‘rudimental and inferiorly placed vertebral pieces.”
It seems evident that the rib-head of the eighth costal was connected with the most anterior;
the rib-head of the tenth rib with the second; while the first sacral rib-head joined the third.

The portion of the xiphiplastron present shows this part of the shell to have been thinner
than in J. molops. The thickness at the hypoxiphiplastral suture is 7mm. The edge of the
bone at the bottom of the posterior notch is present. This edge is acute, while from it the bone
thickens to only g mm. The scar for the pubis is somewhat elongated, 46 mm. long and g mm.
wide; therefore, much narrower than in J. molops. On the inferior surface is seen a distinct
reticulate sculpture of moderate closeness.

No. 1469 of the American Museum, a part of the Cope collection, is labeled by Cope as
having been found at Barnesboro, New Jersey, in 1869; but it has not been identified as any
one of those mentioned in his monograph so often quoted here. The left second costal bone is
39 mm. wide at the middle of the length and 8 mm. thick. The third costal is 49 mm. wide at the
middle of its length. Besides these costals, there are present portions of the three posterior of
the right side. These agree with those of No. 1468 described above. Attacht to the sixth
costal is the sixth neural. It is hexagonal, 35 mm. long, 36 mm. wide, and 8 mm. thick. The
epidermal scute areas also are like those of number 1468. The lateral apex of the second
vertebral is 67 mm. from the neural border of the costal. Most of the right hypoplastron is
preserved. The length at the midline is about 105 mm.; the width at the abdomino-femoral
sulcus 130 mm.; along the hyohypoplastral suture, 100 mm. The bone is 8 mm. thick at the
anterior inner angle; 6 mm. at the hy poxiphiplastral suture.

This species differs from T. longinuc hus in having the suprapygal wider than long and in
having the fourth vertebral scute relativ ely much wade

Taphrosphys longinuchus Cope.
Text-figs. 101, 102.

Taphros phys (Prochontas) longinuchus, Corr, Ext. Batrach., Reptilia, Aves N. A., 1870, p- 159.
Taphros phys longinuchus, Corr, op. cit., p. 162; Vert. Cret. Form. West, 1875, p. 263.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 438.

Cope stated in his description of this turtle that it had been obtained from the excavations
of David Haines, New Jersey. The label accompanying the specimen, now number 1125 of the
American Museum of Natural History, informs us ae the locality was Medford, which is in

Burlington County. The level is stated by Cope in his Vertebrata
of the Cretaceous Formations, page 263, as being “‘Greensand
Neural’) jp cLengthe” ) )Wadth: No. 5,” which would be the upper bed of Cretaceous greensand.

The type specimen furnishes a large portion of the carapace

and of the plastron, but it was much fractured. Fig. ror repre-

I rt:
a 34 sents the restored carapace; fig. 102 the restored plastron. A con-
: a 56 siderable number of other fragments remain, but can not be fitted
5 32 22 to their places.

; ee = The species was one of moderate size and one whose shell

was of rather light construction. The length of the carapace (fig.

101) was close to 415 mm.; the width about 390 mm. The
form was deprest and convex in all directions. Only the eighth peripheral shows any tendency
toward upward flaring. Only 3 neurals have been preserved—the fourth, fifth, and seventh.
The forms of most of the others are indicated by the proximal ends of the contiguous costals.
The dimensions, so far as determinable, are given in the accompanying table.

BOTHREMYDID. 109

The borders of the fourth and fifth neurals are 8 mm. thick. On the under side of each
is attacht the neural arch of the corresponding vertebra. The eighth neural was not developt
and the costals of the seventh and eighth pairs met at the midline. The ninth and tenth dorsal
vertebra and the first sacral appear to have had their arches articulated with the inferior
surface of the seventh and eighth costals at their junction. The accompanying table gives the
dimensions of the three posterior neurals.

The nuchal bone is urn-shaped, go mm. long, 43 mm. wide in front, 86 mm. across the
widest part, and 10mm. thick. Its free border is acute. The first peripheral measures 58 mm.
along its free border; the second, 53 mm. The first appears to
have been about 60 mm. high, measured at the suture with the
second. The free border of these two peripherals is subacute.
The greatest thickness of the second, at the distal end, is 12 mm.

66 67 On the right side most of the peripherals are wanting from the

E x * second to the eighth (exclusive of both); all are missing behind the

: second on the left side, except one, probably the sixth. The upper

and lower faces of this sixth meet at the acute free border at an

angle of about 45°. This border is 45 mm. long and from this the bone rises 56 mm. to the

costals. In the restoration (fig. 101), this bone has been omitted from its supposed place.
The lower face of the bone, that proceeding to the plastron, is mostly missing.

Neural. Length. Height.

Fic. 101.—T aphrosphys longinuchus. Carapace of the type. 4. The stippled areas
represent the known bones.

All of the peripherals have acute free borders. Of the eighth, that portion to which the
inguinal buttress was attacht is broken away. From the free border each of these bones
thickens on the under side to half its height, then becomes gradually thinner.

The suprapygal is triangular, 62 mm. long and 60 mm. wide posteriorly. Evidently it
articulated on each side with the eleventh peripheral and medially with the pygal.

110 FOSSIL TURTLES OF NORTH AMERICA.

The fore-and-aft width of the first costal is 64 mm. at the proximal end; its greatest width
was about go mm. Its length is estimated at 120 mm. On the lower side, at the distal end, is a
deep triangular excavation, 40 mm. long, for the axillary buttress. From it a broad ridge
ascends to the rib-head of the costal. ie front of the ridge, along its proximal third or more,
is another ridge, sharper and more prominent, representing the fat rib.

The fifth costal is 6 mm. thick at its distal end. On the under surface of the distal end is an
excavation for the inguinal buttress, a groove ascending about 60 mm. above the peripheral
border and 6 mm. wide. It is deepest at the upper end, becoming very shallow at the lower end.

The seventh and the eighth costals are modified for close articulation with the ium. On
the seventh the thickening produced by the rib proper lies near the hinder border of the bone.
The hinder part of the thickening is excavated somewhat, espe-
cially near the proximal end of che costal, to form a broad groove

Vertebral. Length. Width.
for the ilium. The proximal end of the groove is closed ‘partly
by the ridge proceeding from the rib-head of the eighth costal and
; 75 Bo partly by a subcubic bone, which appears to be the tenth rib.
2 75 77
‘ ne co This lies in a depression of the eighth costal. The iliac groove
4 75 86 is 18 mm. wide at its upper end; and here its bounding walls are
5 ; 110

most prominent. Behind the ridge limiting the groove posteri-
orly is another groove, shallower and roughly Sree which
appears to have lodged a bone, probably the first sacral rib.

The surface on the carapace is even, but it is sculptured everywhere by a network of
shallow grooves. On the costals the network is the coarsest, the grooves lying from 2 mm. to
5 mm. apart and mostly directed parallel
with the length of the costal. On the
neurals and peripherals the network is
much closer.

The sulci of the carapace are broad
and shallow. There is no nuchal scute,
the first marginals joining at the midline a
distance of 44 mm. The length of the sul-
cus between the first and the second margi-
nals is 44 mm.; that between the second
and the third, 23 mm. The sulcus between
the eighth and ninth marginals, on the
eighth peripheral, is 37 mm. long; the next
one, 31 mm.; the next, 27 mm.

The vertebral scutes of this species are
much narrower than those of TJ. leslianus,
as shown by the table above.

The sulcus between the fifth vertebral
and the hindermost marginals falls behind
the suprapygal.

The exact length of the plastron (fig.
102) can not be determined, the connection
between the epiplastron and the hyoplas-
trals not being present. The length was,

type. 4. Known portions represented by however, NOE far from 340 mm. The notch

stippled areas. in the rear of the plastron was about 30

mm. deep, so that the length along the
midline was about 310 mm. ‘The epiplastrals are relatively small, especially when compared
with those of Hydromedusa. The hinder end of each is broken off, but each was probably
about 70 mm. long. The width was about 33 mm., while the greatest thickness of the outer
end is 7mm. The free border*is acute at the midline, becoming subacute distally. Cope
describes, under the name of mesosternal, a portion of the entoplastron, but this is now lost.
He did not give the dimensions. He states that the extremities are acute-angled and that
the bone was even more transverse than it is in 7. molops.

hic. 102.—Taphrosphys longinuchus. Plastron of

BOTHREMYDID. III

At the midline the hyoplastra are 77 mm. long. ‘The usual thickness of the bones is 6 mm.
Laterally, each rises into a rather broad, but thin, axillary buttress. The bridge was probably
about 125 mm. long. ;

The hypoplastrals are 87 mm. long at the midlin . The bridge portions of the bones are
mostly missing. There is no trace of the mesoplastrals, tho these doubtless were present.

The xiphiplastrals extend 82 mm. along the midline. The notch in the rear is 90 mm.
wide. The borders of the hinder lobe are thin and acute. On the upper surface of the xiphi-
plastrals are the articular scars for the pubes and the ischia. The scars for the latter are
mammiform, 17 mm. long and 11 mm. wide, and are sharply ridged and cleft. The pubic
scars are somewhat elevated, 40 mm. long, g mm. wide, and rough.

The arrangement of the scutes of the anterior lobe can not be wholly determined. On the
epiplastra appear a pair possibly coalesct at the midline, the gulars. There was probably an
intergular on the entoplastron. The sulci that separated the humerals from the pectorals is not
seen. The latter scutes crost the plastron about 18 mm. in front of the hyohypoplastral suture.
The abdominals are 40 mm. wide at the midline; the femorals, 90 mm.; the anals, 60 mm.

Cope described limb bones which he regarded as two humeri and a small part of the prox-
imal end of femur, but it is quite certain that what he called humeri are femora. The right
femur lacks the fibular process and the distal end. Of the left femur there is the distal end.
These bones agree closely with those of H ydromedusa, except that the tibial process extends
down farther on the shaft. Cope estimates from these bones that the length was 97 mm. It
was probably 10 mm. shorter. What seems to be the head of a humerus is too imperfect for
definite conclusions.

Fic. 103.—Taphros phys leslianus. Anterior half of carapace of type. +4. Known bones
3 P t } yp 3
shown by stippled areas.

Taphrosphys leslianus Cope.
Text-figs. 103-106.

Taphrosphys leslianus, Cope, Ext. Batrach., Reptilia, Aves N. A., 1870, pp. 159, 166; Vert. Cret. Form.
West, 1875, p. 264.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438.
Prochontas lesltanus, Corr, Ext. Batrach., etc., p. 165, line 14.

The present species is, up to this time, known from only a single specimen, Cope’s type,
No. 1467, of the American Museum of Natural History. This specimen has not, until this
time, been figured. In his description of the specimen Cope did not state the locality or the
level from which it had been derived; but his label accompanying the specimen informs us that
it was found at Hornersville, New Jersey. This is in Monmouth County. In his Cretaceous
Vertebrata, page 264, he informs us that it belongs to “‘Greensand No. 5;”’ so called because
he regarded the uppermost bed of Cretaceous greensand as representing the Fox Hills group.

The type specimen consists of the left side of the nuchal, the first and second left periph
erals, a posterior peripheral, a part of both costals of the first pair, the whole of the third

112 FOSSIL TURTLES OF NORTH AMERICA.

costal of the left side, parts of the second and the fourth left costals, the distal end of the fifth
right costal, the entoplastron, the left hypoplastron, and a portion of the right xiphiplastron.

The species was one of relatively small size, with a deprest carapace (fig. 103), probably
about 260 mm. long. The carapace is thin, the first costal being 6 mm. thick at the center;
the fourth at its sutural border, 5 mm. thick. The first neural has a length of 35 mm. and a
width of 18 mm.; the second, a length of 20 mm. and a width of 24 mm. The next two were
somewhat longer. The broader end of each was in front, as in the genus generally. The
nuchal bone was relatively long and narrow, the length being close to 67 mm., the width close to
60 mm. The width in front was only 28 mm. Tie bone Hee eailes closely ‘that of H ydrome-
dusa. Its anterior border was thin and acute.

The first costal bone is 62 mm. wide fore and aft, and 75 mm. long and 6 mm. thick posteri-
orly. On its inferior surface at the distal end is an excavation for the axillary buttress. This
rises 30 mm. above the lower end of the bone and is 9g mm. wide. The third costal is 21 mm.
wide and 105 mm. long. The right fifth is 33 mm. wide distally. On its inner surface, near
the distal end, is an excavation for the inguinal buttress, 33 mm. long and 7 mm. wide. The
first and the second, and probably all the other costals articulated wich the peripheral bones.
The rib-heads were moderately developt.

yop

Fics. 104 AND 105.—Taphrosphys leslianus. Portions of type.

104. Entoplastron. 3. 10s. Portions of rear of plastron. 4.
4 P 3 5 Pp 3

Known bones shown by stippling.

The first peripheral has a length of 42 mm. along the free border, and rises from this a
distance of 49 mm. The second is 37 mm. along the free border and 33 mm. high. The free
border of the first is acute; that of the second, subacute. The upper surface of each is convex
in all directions. The thickness of the hinder end of the second peripheral is 8 mm. A posterior
peripheral is 35 mm. long. It flares upward toward the free border. The latter is acute.

The surface of the carapace is smooth, but there appears everywhere a rather indistinct
reticulation of grooves, which are narrower than the inclosed spaces.

The sulci are shallow but not difficult to trace. There is no nuchal scute. The first
marginals join at the midline a distance of about 30 mm. The sulcus between the first and
second marginals is 38 mm. long; that between the second and
the third, 22 mm. Posteriorly the marginals rose rather high on
the peripherals. The intermarginal sulci are nearer the anterior
ends of the peripherals. The vertebral scutes have the dimensions
I 48 64 given in the accompanying table.

55 The entoplastron (fig. 104) is diamond-shaped, with rounded
angles. The length is 30 mm.; the width, 31 mm.; the thick-
ness, 3.5 mm. No other part of the anterior lobe is present.

A considerable portion of the left hypoplastron is preserved (fig. 105). The hyoplastral
border makes an angle of about 60° with the free border of the hinder lobe and a right angle
with the median border, so far as the latter is represented. Cope appeared to thine that the

Vertebral. Length. Width.

vs)
1

BOTHREMYDID&. 113
mesoplastron continued to the midline. This is not probable. The mesoplastron evidently
extended inward only to the change in the direction of the anterior border of the hy poplastron;
that is about one-third the distance from the peripherals to the midline.

The inguinal buttress is prominent, but thin. The hinder lobe narrowed rapidly, so that,
while aout 150 mm. wide at the inguinal notch, it was only about 120 mm. at the hypo-
xiphiplastral suture. The thickness of the bone behind the inguinal notch is 4 mm. Only a
fragment of the right xiphiplastral is preserved. It extends fac the midline to the free border
along the anterior end; backward to behind the scar for the pubis. The free border was acute.
The ischiadic scar is elevated, 28 mm. long, and 11 mm. wide.

The surface of the plastral bones shows no sculpture. On the entoplastron may be traced
sulci bounding laterally and posteriorly the intergular scute. Its anterior boundary can not be
made out. On the xiphiplastron is seen the femoro-anal sulcus, 18 mm. behind the front border
at the midline; 26 mm. toward the free border.

No. 1471 of the American Museum of Natural History is referred provisionally to this
species. The specimen was one of the Cope collection and accompanied another specimen
that was labeled as coming from Barnesboro, Gloucester County, New Jersey. Without
doubt it came from the Upper Cretaceous. It consists of the right epiplastron (fig. 106), a part
of the left epiplastron, a portion of the left hyoplastron, a part of the left hypoplastron, and a
few other fragments. The individual was nearly as large as the type of 7. molops, and there-
fore considerably larger than the type of 7. le slianus. ee plastral bones are thin, the thick-
ness of the hinder end of the epiplastron being 8 mm., that of the hyoplastral border near the
axilla,g mm. They are thinner than most of the corresponding bones of the type of 7. lon-
nines. a considerably smaller individual.

The epiplastron measures, in a straight line from the epiplastral symphysis to the hyo-
epiplastral suture, 86 mm. The length of the symphysis is 20 mm.; the greatest width of the
epiplastron is 37mm. An abrupt ridge
at the symphysis increases the thick-
ness to 10 mm. The free border is
subacute for a short distance on each
side of the midline; elsewhere, obtuse.
Most of the free border of the hyo-
plastron is obtuse.

The entoplastron had a width of
close to 70 mm.; it was probably not
over 60 mm. long. The thickness of
the hyoplastronimmediately behind the
entoplastron is 6 mm.

The fragment of hypoplastron ex-
tends along the midline go mm. This
suture was very jagged. At a ridge
on the upper surface near the front of this bone the thickness amounts to 12 mm. Posteriorly
it becomes reduced to 5 mm. Of the hyohypoplastral suture there is present 110 mm.
The hinder bone was somewhat overlapt by the hyoplastron.

The inferior surface of these bones shows little sculpture. Only faint traces are seen of the
network of grooves present in most of the species of the genus. On the hypoplastron are seen
some faint grooves running at right angles with the median longitudinal suture.

About certain of the anterior sulci there is some doubt. Those which appear to be present
are represented in fig. 106. There is some doubt about the first sulcus represented on each
side of the midline. Probably there ought to be a sulcus drawn across the anterior end of the
entoplastron, but since this bone is missing we can not determine this. There is certainly a
gulo-humeral sulcus across the epiplastron, ana a humero-pectoral across the front ends of the
hyoplastrals. The abdomino-femoral sulcus crost the hypoplastron 39 mm. behind the
hyohypoplas‘ral suture. Mainly on account of the thinness of these bones they are refer red
to J. leslianus; for there are no parts common to this specimen and the type. The parts ot
the hypoplastra present hardly coincide. No. 1471 was considerably larger.

Fic. 106.—Taphrosphys leslianus. Anterior lobe of
plastron. 3. No. 1471 A. M. N. H. Known
bones shown by stippling.

8

114 FOSSIL TURTLES OF NORTH AMERICA.

Taphrosphys strenuus Cope.
Figs. 107-111.

Taphrosphys princeps, Corr, Cook’s Geol. New Jersey, 1868 (1869), p. 735 (name only).
Taphrosphys strenuus, Corr, Ext. Batrach., Reptilia, Aves N. A., 1870, pp. 157, 166-B; Vert. Cret.

Form. West, 1875, p. 264; Kerr’s Report Geol. Surv. N. C., 1875, Append. B, p. 34; Amer. Nat-

uralist, x11, 1878, p. 128.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 439-
Prochonias strenuus, Corr, Amer. Naturalist, 111, 1869, pp. 89, 90; Ext. Batrach., etc., pp. 159, 167.
Prochonias princeps, Corr, Amer. Naturalist, 111, 1869, p. 89; Ext. Batrach., etc., pp. 160, 167, line 44.

Altho the present species had been previously mentioned, the earliest description of it is
found in Cope’s monograph on the Extinct Batrachia, Reptilia, and Aves of North America,
page 166-B, issued in April, 1870. Here Cope states that he had in his possession 3 specimens.
Only one of these, the second mentioned by him, has been found in his collection in the
American Museum of Natural History. This has the number 11206. It appears that the first
specimen mentioned by him had been intended as the type of the species, while the one now
numbered 1126 had been intended as the type of his species princeps. Before the description
of the latter was printed it appears that he concluded to abandon it. Cope’s description of
T. strenuus bears evidences of imperfect revision. The second specimen, number 1126, is
labeled by Cope as having been obtained from the West Jersey Marl Company’s pits at Barnes-
boro, Gloucester County, New Jersey. The level is the Upper Cretaceous. The remains
are much broken, consisting of about 75 pieces; and so many parts are missing that it is
impossible to determine the exact position of many of those which remain. Of the neurals
none is preserved. A few fragments of the costals remain. One, probably the fragment

i
Fic. 107.—Taphrosphys strenuus. Anterior lobe of plastron. 3. No. 1126 A. M.N. H.

Known portions shown by stippled areas.

whose width and thickness are given by Cope, is gt mm. long, 57 mm. wide, and 10 mm. thick.
The rib scarcely shows on the inferior surface. The upper surface presents a network of
shallow grooves at one end, but at the other the grooves inosculate but little and run nearly
parallel with the sutural borders. Cope states that the peripherals are rough from the reticu-
late sculpture. A fragment of what is believed to be an anterior peripheral shows a close
network of grooves. The greatest thickness of this bone is 21 mm. Its free border is obtuse.

Large portions of the plastron are preserved. The bones are thick and heavy. Pieces
which belong at the crossings of the sutures measure in thickness about 18 mm., increasing in
places to 20 mm. As in other species of the genus, the transverse sutural faces are oblique to
the upper and lower surfaces of the plastron, so that the hyoplastron overlapt somewhat the
hypoplastron; and the latter, the xiphiplastron. On the inferior surface the network of
grooves is coarse. On one fragment is seen a narrow and shallow sulcus.

The anterior lobe of the plastron was broad and short (fg. 107). The right epiplastron is
present and shows the whole of its free border, but some of the entoplastral border is broken
away. To this is attacht a part of the free border of the hyoplastron. The width of the lobe
at the hyoepiplastral suture was close to 300 mm. The front of the lobe was concave for a
considerable distance on each side the midline. The fragment of hyoplastron is 18 mm. thick,
but it thins to the subacute free border. On the epiplastron the free border becomes obtuse,
the thickened part of the bone coming nearer the edge than on the hypoplastron. At the
epiplastral symphysis the bone rather suddenly thickens to 22 mm.

BOTHREMYDIDE. I 15

The entoplastron must have been unusually large. Its anterior end approacht within
32 mm. of the anterior border. The anterior angle was slightly greater than 100°. The sides
bounding this angle were approximately 130 mm. long. The width must have been about
160 mm. The inferior surface of the epiplastron displays an obscure reticulation, but the
hypoplastron is smooth.

There are present 2 fragments of the right xiphiplastron. One of these is the hinder angle
and bears the ischiadic articulation; the Gels shows the bottom of the great notch at the rear

poe 109. and a part of the edian suture. These
5 4 i fragments join and are represented by fig.
) ; _ 108. The angular extremity had a very obtuse
. ; 110. tree border. A short distance from the edge
: the thickness is 17mm. The ischiadic articu-
latory (fig. 108, #) surface is elevated and
about 40 mm. long and 24 mm. wide. It is
now much eroded. In front of this articula-
tion the thickness is 13 mm. The median
—.~ longitudinal suture is coarse and jagged. Fig.
iad poe gs er sirendus: 3 TOO Teptesents.a section across the hinderouter
eseeA A NOE: angle along the line CD of fig. 112. Fig. 110
: is a section along the line 4B of fig. 108. The
ee Aa a al i oe ane posterior notch was about 180 mm. wide and
represented by figure 109; E, ischiadic articulation, | relatively shallow. It appears to differ much
109. Section along line CD of figure 108. from the notch in other species of the genus.
Baan > on along. ling Po Agbre 708, While the free border of the extremity of

111. Section at hypoxiphiplastral suture. A aad J
the xiphiplastron is very obtuse, more anteri-

orly it becomes acute. Fig. 111 is a section at the hypoxiphiplastral suture.

Cope described a bone which he regarded as the proximal end of the femur. With little
or no doubt the bone is the left humerus. It presents close resemblances to the corre-
sponding bone of Chelydra, the radial and ulnar processes, however, not being so thin as in
the latter genus. Cope also described as a coracoid a bone which certainly “belongs to the
pelvis, having, as Cope states, 2 sutural faces and 1 cotyloid face.

Taphrosphys molops Cope.

Figs. 112-120.

T aphros phys molops, Core, Cook’s Geol. New Jersey, 1868 (1869), p.735 (name only); Amer. Naturalist,
11, 1869, p. 893 Proc, Amer. Philos. Soc., x1, 1870, p. 274; Ext. Batrach., Reptilia, Aves N. A.,
1870, pp. 158, 159, plate vii, fg. 16, text-figs. 43, 44; Vert. Cret. Form. West, 1875, p. 263.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438.

Taphros phys molops var. enodts, CoPE, ane eaear , ete., p. 162.

Prochontas enodts, Cope, Ext. Batrach., etc., pp. 158, 160.

Bothremys (Taphros phys) molops, Z11TE1., ‘Handbuch Palzontologie, 1889, p. 547.

Of this species Cope had a number of specimens, none wholly complete, most of them
very incomplete. The one which presented large portions of the carapace and the plastron
had been obtained from the upper bed of Creticests greensand, at Barnesboro, Gloucester
County, New Jersey. This specimen is now in the American Museum of Natural History and
has the number 1472. Portions were figured by Cope, and it seems proper to regard it as the
type of the species. It is probable that the description of a specimen from SPomncrtow n
appeared a short time before the detailed description given in the Extinct Batrachia, etc.; but
that earlier description is not one that would enable us to determine the species, no part was
figured, and the specimen was not intended by Cope to stand as the type.

Of the carapace (fig. 112 ) Cope figured the nuchal and the right and left first peripherals.
Portions of all these bones are now missing. The anterior outline of the carapace was rounded
as in T. longinuchus, and the free border was acute. The shell appears to have been of only
moderate convexity. The width of the nuchal anteriorly was 50 mm.; its greatest width, close
to 115 mm.; its length was probably about 115 mm. Its proportions were therefore as in 7.

116 FOSSIL TURTLES OF NORTH AMERICA.

longinuchus. From the acute edge the bone thickens, at first rapidly, then gradually, to 12 mm.,
at the middle of the length. The first peripheral has an extent of 82 mm. along the free border,
and 80 mm. from this to the hinder border. Its thickness is about that of the nuchal. The
second peripheral measures 65 mm. along the free border. The edge is acute.

None of the hinder peripherals is present, but there are parts of two from the bridge
region. One of these is 65 mm. long and presents 2 faces, which meet at a right angle along an

Fic. 112.—Taphrosphys molops. Restoration of carapace of type. 3. No. 1472 A. M. N.H.
Known portions represented by stippled areas.

obtuse lateral carina. Fig. 113 presents sections of the ends of this bone, a showing the ante-
rior end, }, the posterior. A sulcus crosses both faces a little nearer the thicker end. The width
of one face, probably that parallel with the plastron, is 43 mm. The other peripheral presents
2 faces meeting at an acute angle. Fig. 114 shows sections of the ends of this bone, c being the
anterior end, d, the posterior. The length of the bone is 60 mm. It seems quite certain that

BOTHREMYDID. 1 GF

the peripheral with the obtuse carina is the more anterior, the one with the acute carina
belonging near the inguinal notch.

Portions of the right and left first costals are present. ‘These fragments show that these
bones had an antero-posterior width of about 110 mm. The thickness at the neural border is
between g mm. and 10 mm. On the inferior side of the bone is seen the base of the rib-head;
in front of this a sharp ridge corresponding to the first rib. Each of the first costals articulated
with four peripherals. A ridge proceeding from the rib-head becomes, toward the peripheral
border, high and broad. In this is excavated a large pit, 20 mm. wide and rising about 50 mm.

a b é d

" ‘
i it
a) s%

SO (\ be ee

Tia 114.
Fics. 113-115.—T aphrosphys molops. 4. No. 1472 A.M.N

113. Sections of a bridge peripheral. a, anterior end; 6, posterior end.
114. Sections of another peripheral of bridge. c, anterior end; d, posterior end.
115. First costal, inner surface. Shows axillary pit.

above the lower border of the costal (hg. 115 ). “This is for the reception of the axillary buttress.
Its upper end is much the deeper.

There are fragments of the second, third, fourth, fitth, and sixth costals. These are
represented in the restoration (fg. 112). From the proximal end of costals three and four we
get an idea of the forms of nemesis: but only approximate information regarding their widths.
The third costal is 12 mm. thick at the neural border but only 6 mm. at the distal end. The
fifth and the sixth costals are wider than those preceding them, as in T. longinuchus.

Fic. 116.—Taphrosphys molops. Anterior half of plastron of type. +.
Known portions stippled. —™.p, mesoplastron.

The upper surface of the nuchal and the anterior peripherals is rather strongly sculptured
with a network of grooves. The interspaces vary greatly in form and size, few being less than
5 mm. in diameter. Of the bridge peripherals one face is distinctly sculptured, the othe:
obsoletely so. The sculpture on the costals is distinct, but usually not so strongly exprest as on
the nuchal. The deepest furrows are mostly nearly parallel with the long axis of the costal.

The sulci are shallow but distinct. There is no nuchal scute. The queue between the
first marginals is 58 mm. long. Each measures 66 mm. along the free border. The second
marginals had an equal extent along the free border. The width at the anterior end is 60 mm.;
at the distal end, 40 mm.

118 FOSSIL TURTLES OF NORTH AMERICA.

The first vertebral scute had a length of about go mm., a width of about 140 mm. in front
and of about 80 mm. behind. The approximate proportions of the next three are shown in the
restoration.

Cope figured (Ext. Batr.,Rept., etc., p.160, fig. 43) a considerable part of the anterior lobe
of the plastron. Another portion of the same specimen has been found, the border of the left
axillary region, and this is included in fig. 116. This specimen suffices to give us a clear idea
of the form of the anterior half of the plastron. This lobe had a length of about 135 mm. and
a width of about 260 mm. It was rounded in front, with a slight median concavity. The free
edges are obtuse, except at the union of the epiplastrals with the hyoplastrals. The thick-
ness is everywhere close to 10 mm. The entoplastron was diamond-shaped, 65 mm. long and
86 mm. wide. The suture of the hyoplastron with the hypoplastron was oblique to the surfaces
of the bones, so that the hyoplastron overlaps the hypoplastron somewhat. A portion of the
axillary region is preserved. The base of the buttress did not extend far within the free border
of the anterior lobe.

It is unfortunate that the epiplastron is not complete to the midline, for we are left in some
doubt regarding the more anterior scutes. An intergular occupied a large part of the entoplas-
tron. Cope represented this as overlapping some distance on the epiplastrals, but it seems to
the writer that a sulcus crosses the entoplastron close to its anterior border. Probably the
culars met, possibly coalesct, at the midline, in front of the intergular. The humerals occu-
pied the hinder half of each of the epiplastra. In some specimens of this genus there seems to
be a scute cut off from the inner end of each gular. Such a scute, or such scutes, would be
without name. Better specimens are required to settle this matter. The arrangement of the
scutes in this region appears to resemble that of Chelodina. The pectorals measure 87
mm. along the midline; the abdominals occupy the posterior 26 mm. of the hyoplastra.

Cope presents a figure of the hinder half of the plastron of this specimen. It 1s difficult to
determine just how much of that part of the plastron was in his hands. At present there is
with the specimen only a fragment of the left inguinal region, a fragment of the left xiphiplas-
tron, and the hinder angle of the right xiphiplastron. The latter is marked in Cope’s figure
with the letters /s. The fragment of the inguinal region extends forward to the suture with
some bone, probably the mesoplastron. On the upper surface about 40 mm. behind this
suture is a prominent ridge, the base of the inguinal buttress. This ridge is much more
strongly developt than in 7. longinuchus.

The base of the xiphiplastron presents a coarse suture with the hypoplastron. The free
border of the bone is acute. From the edge the bone thickens to 12 mm. On the upper
surface of this bone is a part of the much elevated and rough articulating surface for the pubis.
On the hinder angle of the xiphiplastron is the circular elevated and rough surface for articu-
lation with the ischium. The notch in the rear of the plastron was about 140 mm. wide.

On the anterior half of the plastron there is little evidence of sculpture. It is more conspic-
uous on fragments of the hinder half, where it consists of a network of grooves.

Cope mentions a specimen of this species from Hornerstown, New Jersey, which displayed
the mesoplastral bones. These presented a rounded interior outline and were applied to an
equal extent of the hyoplastrals and the hypoplastrals. They reacht one-third the distance
toward the midline. The plastron was 10.5 inches between the inguinal notches. The speci-
men is now lost.

Another specimen, No. 1343 of the American Museum, an individual a little larger than
the type, shows a portion of the right hyoplastron from front to rear. The length is 170 mm.
Just behind the axillary buttress the posterior sutural border makes a turn forward at nearly
a right angle. It appears evident that this was to receive the mesoplastron. No. 1474 of
the American Museum, a part of the Cope collection of fossil reptiles, was obtained by Cope,
February 22, 1871, and therefore not mentioned in his monograph of 1869 and 1870. It
came from Birmingham, Burlington County, New Jersey. It furnishes, besides some fragments
of costals, a large part of both hypoplastra and the complete left xiphiplastron (figs. 117, 118).
The individual was of almost exactly the same size as the type. The distance along the median
line, from the hyohypoplastral suture to the bottom of the notch in the rear, is 243 mm. The
left hypoplastral came into contact with the right xiphiplastron, an irregularity not uncommon
in the early turtles. The right hypoplastron is 115 mm. long; the left xiphiplastron, 105 mm.;

BOTHREMYDID&. 1p) (0)

both measured at the midline. Neither hypoplastron exhibits either the inguinal region or the
border for the mesoplastron.

The hyoplastron overlapt somewhat the hypoplastron, and the latter similarly overlapt
the xiphiplastron. At the antero-interior angle the hypoplastra are 16 mm. thick; at the
postero-interior angle, 8 mm. The whole free border of the hinder lobe is acute. The hinder
notch is 135 mm. wide. and 42 mm. deep. On the upper surface of the xiphiplastron (fig. 118)

———

Fics. 8 119.—T aphros phys molops.

117. Hinder half of plastron seen from below. 4. No. 1474 A.M.N.H. Known bones inclosed by solid lines.

118. Upper surface of left xiphiplastron. ><}. No. 1474 A. M.N.H. Shows ischiadic and pubic articulations.

119. Three neural bones. 4. No. 1470 A.M.N.H.
are seen the circular scar for the ischium and the elongated one for the pubis. Both are elevated
and furnisht with sharp ridges.

The inferior surface of this part of the plastron is rough, due partly at least to erosion.

The abdominal scutes occupy about the anterior 30 mm. of the hypoplastra. The femorals
are large, measuring about 135 mm. along the midline; the anals, 75 mm.

The specimen of this species mentioned by Cope as having come from Birmingham ts now
No. 1129 of the American Museum. The femur supposed by Cope to belong with the specimen
is missing. The remaining fragments throw no light on the species.

No. 1470 of the American Museum is labeled by
Cope as having been received by him ‘9/8, 1870,” and
was therefore not mentioned in his monograph. It was
secured at Barnesboro. The individual was somewhat
larger than the type. The nuchal bone has a length of
107 mm., a width anteriorly of 64 mm., and a maximum
width of 117 mm. The notch in the midline behind, tor
the first neural, is only 24 mm. wide. Three neural
bones (fig. 119) accompany the lot, but the exact position
of none of them can be determined. None shows a cross-
ing sulcus, and yet two of them were in contact. Figures
of these are presented.

The right first costal shows a great pit for the axillary
oo buttress. A fragment of the right fifth presents the some-
what eroded ridge and elongated pit for the inguinal
The latter is 10 mm. wide. The pubic scar is

Fic. 120.—T aphros phys molops. Por-
tions of seventh and eighth costal buttress. ! :
bones and part of suprapygal. No. 53 mm. long and 15 mm. wide, elevated and rough. I he
1477 A. M.N.H. pubic sear is circular.

120 FOSSIL TURTLES OF NORTH AMERICA.

Cope described a specimen from Barnesboro (Ext. Batr., Rept., etc., p. 161) which is
important because on it he based the distinction between his Taphrosphys and Prochonias.
The specimen is No. 1477 of the American Museum. Cope states that this specimen exhibits
an azygous bone in contact with the caudal marginal. As a matter of fact, all the species
possess such a bone, the suprapygal, but Cope evidently meant a bone still in front of this.
He states that this appeared to be the co-ossifed proximal portions of the last pair of costals
and that the fragment appeared to be bounded posteriorly by a continuous suture. A close
examination of the region in question shows that it is identical in structure with the same
region in J. sulcatus. A figure of the fragment is presented (fig. 120). The costals of the
eighth pair meet in the midline, as usual. Behind them there is the anterior end of the
suprapygal. Cope overlookt the sutures between the suprapygal and the eighth costals and
the suture between the contiguous ends of the costals just mentioned. hee xiphiplastron is
present and shows the Features described by Cope. The epiplastron lacks the outer end. On
the free border, at a distance of 48 mm. from the symphysis, begins the gulo-humeral sulcus, as
in the figure of the type. There appears to be no sulcus nearer the symphysis. Furthermore, no
sulcus is seen running in front of the suture with the hyoplastron and toward the opposite side.

Cope described a variety enodis of this species. The specimen on which this was based has
not been seen by the present writer. According to Cope’s description the free border of the
hypoplastron was of equal thickness and equally obtuse, differing thus from the typical speci-
mens of J. molops. Also the free margin of the hyoplastral was comprest and acute. It may
be a distinct species.

Taphrosphys dares sp. nov.

Figs. 121-124.

No. 1127 of the American Museum of Natural History belongs to portions of a fossil
turtle which is a part of the Cope collection of fossil reptiles. No label came with the speci-
men to tell what was its origin. The matrix adhering to the bones shows that the fossil did not
come from the greensand of New Jersey. It consists of a yellowish or reddish sand in which
are small flakes of mica. In his monograph of 1869 and 1870 Cope states, on page 167, that
he had received some portions of a Taphrosphys from North Carolina, but the brief descrip-
tion given by him does not agree sufficiently with the specimens here numbered 1127. Cope
had Aico seen specimens of what he regarded as T. strenuus from Georgia, and it appears proba-
ble that these are the ones. Further attention is given this matter below. It had evidently been
Cope’s intention to describe and figure these bones for he has indicated on them that they were
to be numbered 1, 2, 3, and 4.

Wherever these bones were found, it is quite certain that they belong to a species hitherto
undescribed, and were from the Upper Cretaeeous. The lot presents the distal end of a fifth
costal, probably the right, most of a right peripheral, the seventh or the eighth, the entoplastron,
a large portion of the left xiphiplastron, and a fragment of the right xiphiplastron.

The fragment of costal has a length of 180 mm. and a edit of 85 mm. One border has
a thickness of 11 mm.; the other, of 16 mm. The thicker sutural border presents a sort of
tongue, the middle layer of the bone projecting beyond the outer and the inner. The thinner
sutural border has the outer and the inner layers projecting beyond the middle, so that the edge
is grooved. ‘The sutures between the costals seem therefore to have formed what carpenters
call a tongue-and-groove joint. At the distal end of the costal, on the thicker side, is a rough
surface which indicates that the costal was slightly overlapt by one of the peripherals.

The upper surface of this bone is smooth, but it is markt by a coarse network of shallow
and thread-like grooves.

On the inferior side of this costal, nearer the thicker side, is a pit for the reception of the
inguinal buttress of the plastron. This pit is excavated in the summit of a ridge, the rib proper.
The pit has a length of 60 mm. and a width of 23 mm. Its upper end is placed 105 mm.
above the lower border of the costal. Below it is a rough surface which probably joined a
portion of the buttress. Altogether it appears that this costal belonged to the right side; in
which case the thicker border was the hinder one.

The peripheral, the seventh or the eighth of the right side, is massive (fig. 121). Unfor-
tunately the free border is everywhere broken away, so that we can not be certain whether it

BOTHREMYDID&. 121

was acute or obtuse; but the probability is that it was acute. At one point it runs down to a
thickness of only 11.5 mm. The fore-and-aft extent of the bone is 84 mm. ‘The anterior
border is very thick, 52 mm. at one section; and is excavated to form a part of the sternal
chamber. The hinder border was not more than 15 mm. thick. The upper border joined the
ends of 2 costal bones, proof that the peripheral does not belong to the axillary region of the
left side. “

Figure 122 is a section which is taken 20 mm. to the left of the front border. The costal
that articulated with the anterior half overlapt the peripheral, but the succeeding one was
overlapt by the peripheral. Satisfactory contact is not obtained between the peripheral here
described and the fifth costal above described, so that their exact relations are not known.

The upper surface of the peripheral (fig. 121) is ornamented by a network of grooves
similar to those of the costal, but forming a much closer reticulation. That portion of the
inferior surface of the peripheral covered by horn has a still closer network of grooves. On the
upper surface is seen a triradiate sulcus, which bounds a portion of the third costal scute and
portions of two marginals.

Fig. 123 represents the entoplastron. Its length is 84 mm.; its width, 109 mm.;_ its
greatest thickness, 14 mm. In the hinder border is a constriction. The outer surface presents
neither sculpture nor distinct traces of sulci.

Dae fee
Be * Dt a 7 << s -
baa : 124.
{
12 }
© 3 ? =
aN yi
.
} \ J |
\ ) }
a nail 122 |
ee /

Fics. 121-124.—T aphros phys dares. Parts of the type. x 4. No. Li2y A. M.N.H.

121. Seventh or eighth peripheral, upper surface. 123. Entoplastron
122. Section of peripheral of fig. 121. 124. Section along hypoxiphiplastral suture.

The left xiphiplastron is present from the anterior border to the hinder end of the pubic
scar. Its greatest width is 140 mm.; so that the hinder lobe was 280 mm. wide at the hypo-
xiphiplastral suture. This suture was, as seen from below, a very close one; seen from above,
the adjoining bones sent coarse digitations into each other. The anterior end of the right
xiphiplastron overlapt the left as much as 28 mm. The median suture was jagged above,
but more even on the under side. Near the antero-median angle the bone is 17 mm. thick;
the postero-median portion, 12 mm. The free border, for some distance behind the hypo-
xiphiplastral suture, is thin and acute. Fig. 124 is a section taken near the suture. The notch
in the upper surface was filled by a digitation from the hypoplastron. On the upper surface
of the bone is a large elevated area which articulated with the pubis. This articulation is
much eroded. Its length was about 66 mm.; its width, about 27 mm. The lower surface of
the bone shows no distinct sculpture. The femoro-anal sulcus crosses the bone, beginning at
the median line about 45 mm. behind the hypoxiphiplastral suture and meeting the free border
about 66 mm. behind the suture.

What appears to be a portion of the right xiphiplastron is preserved. It bears the elevated
articulation for the ischium. On the left is a part of the median suture. The articulation for
the ischium is about 48 mm. long and 17 mm. wide. Unless there is some error regarding this
bone, the notch in the hinder lobe must have been quite different from that of the other species
of the genus.

ede) FOSSIL TURTLES OF NORTH AMERICA.

While related to 7. strenuus, this species shows several differences. So far as the sculpture
of the costals can be compared, that of 7. strenuus consisted of more numerous and deeper
grooves. The entoplastron of 7. strenuus was much larger than that of the species here
described. As shown by the section taken at the junction erie the hypoplastron the xiphi-
plastron of 7. strenuus thickened much more rapidly and from a less acute edge, and its
hinder portion was considerably thicker than in 7. dares. 5

In the collection of the Geological Survey of Georgia, at Atlanta, are some portions of a
turtle which appears to belong to this species. Indeed, fiiere are reasons for believing that they
are portions of the same individual as the type bones. They are believed to have been secured
in the same locality and formation as the carapace of Peritrestus ornatus; that is, on Bonna-
hachee Creek, Stewart County, Georgia, in the Ripley formation, of the Upper Cretacéous.

Among the fragments is one including apparently the anterior inner angle of the hypo-
plastron. Sixty mm. behind the supposed hyohypoplastral suture the aiickness is 26 mm.
Toward the suture mentioned the thickness is reduced. Here the upper two-thirds of the bone
is beveled off, showing that the hyoplastron somewhat overlapt the hypoplastron.

Another plastral fragment belongs probably to the hypoplastron behind the inguinal notch.
‘Toward the median longitudinal suture the thickness is 16 mm. Toward the free border the
thickness is much reduced, but the edge is rounded. The xiphiplastral bone in the American
Museum shows that as the free border was continued backward it became acute.

Another bone appears to be the second peripheral. It is 100 mm. long on the subacute
tree border. The height was originally at least 82 mm. and the greatest thickness is 25 mm.
‘The upper surface 1s convex from end to end, nearly plane up and down.

Named after Dares, a pugilist beaten in an encounter described in the Eneid, book v.

Taphrosphys nodosus Cope.

Taphros phys nodosus, Corr, Ext. Batrach., Reptilia, Aves N. A., 1870, pp. 159, 167, plate i, fig. 16; Vert.
Cret. Form. West, 1875, p. 264.—-Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 438.

The type of the present species forms No. 1480 of the American Museum of Natural
History. The remains are evidently those of a large, thin-shelled turtle; but these remains
are meager and fragmentary. They were obtained at Hornerstown, Monmouth County, New
Jersey, apparently from the uppermost bed of Cretaceous greensand. The fragments are
charged with iron pyrites and are disposed to fall to pieces. Portions of costals are to be
recognized and a peripheral or two.

Cope figured portions of 2 costals. His fg. 16 1s from a fragment 58 mm. wide and 10 mm.
thick, but the inferior layer of the bone has peeled off. Another bone which comes down to an
acute eee is probably a peripheral. Its thickness at a distance of 25 mm. from the edge is
g mm. . still farther away, it becomes 12 mm. Another piece of bone is part of a bridge
peripheral: having two sc ulptured faces at about a right angle with each other.

The sc ulpture will, more than anything else, assist in the recognition of the species. This
consists of pits and grooves, the latter anastamosing more or fees and separating tortuous
ridges and pustules. ‘The general effect is that seen on the carapace of a coarsely sculptured
trionychid. About 4 ridges are crost by a line 20 mm. long.

This species will perhaps ev entually be found to belong to a genus distinct from T aph-
rosphys. Indeed, the present writer knows of no characters “distinguishing i it from Peritrestus
ornatus (Leidy)

Genus AMBLYPEZA nov.

A genus of pleurodirid turtles which differs from Taphrosphys in having the nuchal bone
Shore and its front relatively broader and in having the free borders of the hinder peripherals
thick and obtuse. Apparently a nuchal scute was present.

Type: Ambly peza entellus Hay.

Amblypeza entellus sp. nov.
Bigs. d25-132-

The type of this species is a lot of bones which belong to the collection of the Geological

Survey of ‘New Jersey, and which were loaned to the writer by the present State geologist, Dr.

BOTHREMYDID&. 123
Henry B. Kimmel. These bones had lain for many years in the basement of the capitol and
all knowledge of their origin had been lost. Without doubt, they had been obtained from the
Upper Cretaceous ereensand of New Jersey.

Of this individual there are large portions preserved, but there are so many parts missing
that the shell can be only partially restored. Of the carapace there were sec ured a considerable
part of the anterior and posterior free borders and some fragments of costals. Of the plastron
some important parts can be identified. The individual is estimated to have had a carapace
about 700 mm. long.

Most of the nuchal bone is present (fig. 125), but, on account of the absence of a section of
it, its exact width can not be determined. It was not far from 120 mm. The hinder portion is
missing. The thickness near the midline in front is 13 mm.; backward the bone thins to
6 mm., while at its outer ends it is 18 mm. thick. The whole free edge is obtuse. The first
peripheral (fig. 125) has a length along the free border of 83 mm., a fore-and-aft extent of
65mm. The thickness at the suture with the second peripheral is 24 mm.; at the suture
with the first costal,8 mm. The second peripheral (fg. 125) extends go mm. along the free
border; 70mm. fore and aft; and is 26 mm. thick where it joined the third. Its hinder
border somewhat overlapt the first costal.

Fics. 125-130.—A mblypeza entellus. Portions of the type in State collection of New Jersey.

125. Nuchal and anterior peripherals of type. }. 127. Section along intermarginal sulcus of peripheral
nu. p, nuchal plate; mu.s, nuchal scute; per. 1, of fig. 126. Xt.
first peripheral. 128. Hinder peripheral. x}.

126. Hinder peripherals (7 ? and 8 ?)of left side of type. x}. 129. Section of peripheral of fig. 128. x}.

130. Inner surface of fifth costal. x4. Shows surface for inguinal buttress.

The peripherals behind the bridges were larger and thicker than those in front. One
whole one and portions of two others are present. The free borders of these are thickened and
very obtuse, thus contrasting strongly with the corresponding bones of T aphros ph: ys. The
exact positions of these posterior peripherals can not be made out. Fig. 126 represents portions
of two; and from the thickness of the bone at the left hand, 27 mm., and the height of the
costo-marginal sulcus, that peripheral is believed to belong not far from the inguinal notch,
being possibly the left eighth. Fig. 127 is a section taken along the intermarginal sulcus. The
upper surface is convex in all directions. On the under side the horn-covered surface rose
above the free border about 45 mm., descending somewhat backward. Fig. 128 represents a
complete peripheral, probably the tenth of the right side; fig. 129 1s a section of the anterio1
end. It measures 104 mm. along the free border aac is 104 mm. high. The thickness near the
lower border is 21 mm.; at the upper border, 13 mm. On the v jeceral side the surface covered
with horn is 40 mm. wide anteriorly, but toward the hinder end is only 15 mm. wide. The free
border is very obtuse.

A fragment of a costal has a length of 130 mm., a width of 77 mm., and a thickness of
15 mm. at the sutural border, 20 mm. through the rib. Another freemen is part of the fifth

I24 FOSSIL TURTLES OF NORTH AMERICA.

costal (fig. 130) and shows the scar for the articulation of the inguinal buttress. This fragment
is 91 mm. wide, 13 mm. thick at the sutural border, and 29 mm. thick through the ridge in
which is excavated the pit for the inguinal buttress. This pit is shallow and quite different
from that of any species of Taphros phys.

The sculpture of the anterior peripherals is obscure, due probably to weathering; that
of the hinder peripherals is more distinct. It is very different from that of Taphrosphys dares,
and consists of a pretty close network of rather broad grooves. On the costals the interven-
ing spaces are about as broad as the grooves and the latter run mostly parallel with the long
axis of the bone.

Fics. 131 AND 132.—Amblypeza entellus. Known parts shown by stippling.

131. Restoration of anterior lobe of plastron. +4. 132. Restoration of hinder half of plastron of type. +4.

Appearances indicate that there was a nuchal scute about 60 mm. wide. If this be true,
the generic distinctions are strengthened. The sulci are, however, obscure. The first vertebral
scute extends much nearer the front of the nuchal bone than in any species of Taphrosphys.
At the midline the distance is only 20 mm. If there is a nuchal scute, the first marginal
measures only 64 mm. along the free border of the carapace. The width at the proximal end
is 24 mm.; at the distal end it has increast to 40 mm. The second marginal is 86 mm. long
and 60 mm. high at the middle of the length. The marginal lying on the supposed eighth and
ninth peripherals is 102 mm. long and 85 mm. high in front. On the supposed tenth
peripheral the marginal descended to within 42 mm. of the lower border of the bone.

BOTHREMYDID&. 125

The bones of the plastron (figs. 131, 132) are so fragmentary and contacts between the
pieces so rare that it is difficult to obtain measurements. The right epiplastron (fig. 131) is
represented by two fragments. One of these furnishes the symphysis. This is 36 mm. long
and the bone is 22 mm. thick. The hinder border was in contact with the entoplastron and is
18 mm. thick. The other fragment furnishes the hinder end of the epiplastron. There is
missing probably only a few millimeters of bone between the two pieces. The epiplastron, and
eherefare the whole anterior lobe, was of a different form from what we see in T aphros phys
strenuus. From the obtuse free border of the epiplastron to the entoplastron was nearly
7o mm. If the restoration here attempted approaches correctness the entoplastron must have
been at least 200 mm. wide.

The hypoplastra at their inner anterior angles are 23 mm. thick. The upper layers of
the hyoplastra overlapt somewhat the hypoplastra.

Of the hinder lobe (fig. 132) there are preserved several pieces. The restoration of this
lobe has been attempted and the recognized pieces of the lobe are represented by the stippled
areas. On the right side is seen a fragment which extends from near the inguinal notch to the
hypoxiphiplastral sulcus. The free border is rather obtuse, but becomes less so toward the
suture. The upper surface rises rapidly about 40 mm. and the thickness becomes 20 mm. On
the left side is a fragment presenting a portion of the hypoplastron and 110 mm. of the free
border of the xiphiplastron. The border may be called subacute. Three pieces of the right
xiphiplastron enable us to make out its characters; two of these form close contact and give us
the hinder angle and the notch. The other piece bears on its upper surface the eroded elevated
scar for articulation with the pubis. It appears to have the size and form seen in the species of
Taphrosphys. Just outside of this surface the bone is 17 mm. thick.

The othe in the rear of the plastron had a width of about 185 mm. and a depth of about
80 mm. As the backwardly projecting angle of the xiphiplastron is approacht the bone
thickens and the free border becomes very obtuse. The thickness just outside the ischiadic
scar is 18 mm. The latter was elevated and rough, and apparently pear-shaped in outline.

The anterior end of the epiplastron is ornamented with a close network of grooves, which
inclose spaces extremely irregular in size and form. On the hinder end of the bone the inclosed
areas are larger, more elongated, and parallel with the free border of the bone. The sculpture
of the rear of f the plastron is similar to that just described. It is obscure on the central portions
of the plastron. The sulci of the plastron are obscure. On the epiplastron there is a gulo-
humeral sulcus beginning 38 mm. from the epiplastral symphysis and running backward
and a little outward to the suture with the entoplastron.

This species is dedicated to Entellus, who, though old and lacking confidence, had endur-
ance and beat his younger opponent (Virgil’s A’neid, book v).

Genus NAIADOCHELYS nov.

An imperfectly known genus of Pleurodira, having the plastral surface smooth, the hinder
lobe deeply and broadly notcht, and a large elevated ech! articular surface which extends to
the midline.

Type: Natadochelys ingravata Hay.

This genus differs from Taphrosphys i in having the lower surface of the plastron smooth,
instead of ornamented with longitudinal or anastomosing grooves, and in having a much more
extensive articular surface for the ischium. At present, only the hinder half of the xiphiplastron
is known.

Naiadochelys ingravata sp. nov.

Fig. 133-

This species is based on a fragment furnishing about the hinder half of a left xiphiplastron.
It was collected in the year 1900, by Professor F. W. Putnam, having been brought to him by
Indians, at Chaco Cany “on, New Mexico. The geological formation whence it was derived is
uncertain, but it was probably the Laramie, which is well developt in that region. The
specimen has been transferred from the department of anthropology of the American Museum
of Natural History to the department of vertebrate paleontology. ‘T he present number of the
specimen is 6078. The small amount of matrix yet clinging to specimen is a yellow sandstone.

120 FOSSIL TURTLES OF NORTH AMERICA.

The fragment of xiphiplastron present indicates a turtle of moderate size, but furnisht
with a very thick and heavy plastron. It is estimated that the plastron had a total length of
18 inches (about 460 mm.). The thickness, to the summit of the ischial articular surface,
is 206 mm.; at the base of this, where it appears to be rising
toward the pubic articular surface, 1g mm.; at the sutural
border for union with the bone of the opposite side, 11 mm.
In a specimen of Taphros phys molops, No. 1474, these measure-
ments, in the order given, are 15 mm., 10 mm., and 10 mm.
This specimen is estimated to have had a plastron 21 inches
long.

The lower surface of the bone is very flat and smooth.
From the outer border the upper surface rises at first rapidly,
then more slowly, to the base of the articular eminence, being
thus convex. From the hinder border the upper surtace rises
more and more steeply, being thus concave. The articular
surface for the ischium is much larger than in Taphrosphys.
It is approximately triangular in outline, the hinder border
running somewhat parallel with the hinder border of the bone,

On. while the outer border runs parallel with the outer border
aie cea Gece of the bone and about 25 mm. distant from it. This articular
$2. NO. 9078 MS surface extends mesially to the midline, differing thus from
Taphrosphys and resembling Hydromedusa. The figure presented will show fhe form and
extent of the surface. At its summit it has been comer eroded, and the border at the
anterior angle may have been slightly extended. Where not eroded, the summit is roughened
to afford attachment to the fechas At the anterior angle of the eminence the smooth Sce
of the plastron at first descends, then begins to ascend, as af rising toward the articular eminence
for the pubis; but no part of this is present.

Fic. 133.—Natadochelys ingra-
vata. Portion of left xiphi-

Superfamily CRYPTODIRA Cope.

Thecophorous turtles having the carapace composed of neurals, costals, and peripherals.
The neurals in a few cases greatly reduced. The plastron having the epiplastra in contact with
the hyoplastra. Entoplastron occasionally wanting. Mesoplastrals, so far as known, never
present. Temporal roof varying from complete to obsolete. Pterygoids extending backward
between the basisphenoid and the quadrates. Neck bending in a sigmoid curve in a vertical
plane and capable of being retracted between the scapula. Elements of the pelvis never
suturally joined to the carapace and the plastron.

Of the Cryptodira there are 8 families and about 140 living species. Their geographical
distribution is discust on page 31 and illustrated by fig. 10. To a greater extent than the mem-
bers of any other superfamily he Cryptodira have been able to adapt themselves to the varying
conditions of the globe. All lands, except the very coldest and the dryest, have been occupied
by them. Most deserts have their species. Species inhabit forests and prairies, swamps,
rivers, lakes, and the high seas. Their structure varies accordingly. By their wide geograph-
ical distribution, the number of their species, and their great differentiation of structure,
the Cryptodira proclaim themselves to be the successful group among the turtles.

Geologically they reach back, according to present knowledge, to the Jurassic, being
represented i in the Lower Kimeridgian of Europe by species of Thalassemy dide.

Fig. 8 represents the author's present views regarding the origin and reJationships of the
various families. Much remains to be determined as to these relationships.

Family THALASSEMYDID Rutimeyer.

Shell more or less incompletely ossified. Usually at least a central plastral fontanel
present; often also costo-peripheral vacuities. Plastron loosely connected with the carapace;
never closely sutured thereto. Limbs fitted for walking; never developt as flippers. Skull,
when known, with the temporal fossze more or less caatt over. ‘Triturating surfaces of the
jaws probably always broad. Neck short.

THALASSEMYDID&. 127

The present writer unites what have usually been regarded as two distinct groups of turtles.
For the one there have been employed the names Elvalesserivdes. Thalassemydide, Eury-
sternida, Acichelyida, for the other the family names Propleuridze, Lytolomide, C helonemy-
dide. The first includes mostly Jurassic genera, the second, Cretaceous and Lower Tertiary
forms. Recently a number of writers have grouped the latter in the family Cheloniidz.

The relationships of the Jurassic genera to Osteopygis and its kindred appear to be too
close to permit the recognition of two distinct families. Much remains to be learned about the
skulls of both groups; but so far as they are known, there appear to be no violent disagree-
ments. In all, the temporal region 1s more or less completely rooft over by bone, and the jaws
are, usually at least, fitted for crushing hard food. Nevertheless, among the Cheloniida, and
some other families, there is the greatest variation in respect to the character of the jaws.

A remarkable resemblance is to be observed between the shells of 4 plax (Eurysternum)
and Osteopygis. Zittel’s figure of the former ( (Palaontographica, xx1v, pl. xxvii) shows that
the hyoplastron sent fouwaad a long process that came into contact with the second peripheral,
just as in Osteopygis. The hy poplastron, too, reacht backward to the eighth peripheral.
There were, likewise, extensive fontanels enclosed by the outer ends of these plastral bones
and the peripherals.

As indicating on the part of writers a recognition of close relationship between the various
elements united here into one family, it may be recalled that, while the later forms have been
actually incorporated with the Cheloniidz, the Jurassic Thalassemydide have been regarded
as the source from which our living sea-turtles have been originally derived.

Key To THE GENERA OF THALASSEMYDID.

es A pit in the second peripheral for the hyoplastron.
At least the two anterior peripher: als suturally joined with disk of carapace. Rib of
eighth costal entering a pit in the tenth peripheral. Shell smooth or pitted Osteopygts
AA. No pit, so far as known, in the second peripheral for hyoplastron.
b. Two anterior peripherals of each side articulating with the disk of the carapace.
c. Rib of eighth costal a i in eleventh peripheral; the skull and lower
jaw cee n. E ... Catapleura
bh. None of the peripherals, so far as known, articulating witb dhe disk.
d. Lower jaw not furnisht with a beak.
Symphysis of lower jaw not more than two-thirds the width of the

jaws at the mental foramina F Lytoloma
e. Symphysis three-fourths the width given . Erguelinnesta

dd. Lower jaw with beak. Skull with rooft temporal region, Choan in
anterior half of roof of mouth. Shell not known ; Rhetechel ys

Genus OSTEOPYGIS Cope.

Carapace including 8 pairs of costal plates and 11 pairs of peripherals, with all or only a
part of the peripherals suturally articulated with the costals and the suprapygals. All the
costals sending the ends of their ribs into pits of the corresponding peripherals. Five vertebral
and 4 pairs of costal scutes. The nuchal scute much wider than long. Plastron relatively
small; its connection with the peripherals extensive, reaching from the second to the eighth
peripherals, not by close sutures. Bridge relatively narrow. Fontanels in the midline and at
the ends of the hyohy poplastral suture. Inframarginal scutes present. Lower jaw with a
broad and flat crushing surface; not beakt.

Ty pe: Osteopygts emarginatus Cope.

This genus was establisht by Cope in 1868 ( Proc. Acad. Nat. Sci. Phila., p. 147), and
had for its type O. emarginatus. With it were included these species described at a later date:
O. sopitus, Om helydrinus, and O. repandus. In his next publication on the subject (Amer.
Naturalist, 11, 1869, p. 88) Cope subdivided the genus, setting up Prople ura with O. sopitu
(=O. borealis) as the type. The two genera were 1 regarded as differing i in this, that Osteopygis
had all the heal suturally ainited with the disk of the carapace, ile in Propleura nee
the most anterior peripherals were so joined.

128 FOSSIL TURTLES OF NORTH AMERICA.

When this author’s work (Synopsis of the Extinct Batrachia, Reptilia, and Aves of North
America) was issued in 1870, he described (pp. 105-234) both Osteopygis and Propleura
as possessing 10 pairs of costal plates. In the latter genus he included only the species
sopitus, his repandus being made the type of a new genus Catapleura, and his chelydrinus
being referred to Osteopygis. Cope concluded that there were 10 pairs of costals because he
found a pit, as if for a rib, in the second peripherals and supposed that he had found a pit in
each of the eleventh peripherals.

In that portion of the Synopsis (pp. 235-252) which appeared in December, 1870, Cope
stated that as regards Osteopygis the ascription to it of 10 pair of costals was an error, the last
peripheral not having had a costal corresponding to it. As to Propleura, he adhered to his
previous opinion ark it possest 10 pairs of costals.

In 1875 Cope (Vert. Cret. Form. West, p. 257) had concluded that the possession by Pro-
pleura sopita of 10 pairs of costals was very doubtful; and this species, with platylomus and
his new erosus were referred to Osteopygis; while chelydrinus went to Catapleura. Cope
still believed that Osteopygis possest at least g pairs of costals.

In 1882 (Proc. Amer. Philos. Soc., xx, p. 144) and again in 1884 (Vert. Tert. Form.
West, p. 112), Cope defined Osteopygis as having 10 pairs of costals and Propleura as having
g, statements directly opposite to those formerly made.

The correction of Cope’s errors regarding the number of costals in the species of this group
was made by Dr. Baur (Zool. Anzeiger, x1v, 1889, p. 42). He studied the very complete
specimen which has since served Dr. Wieland as the type of O. gibbr; and from this he
concluded that there were only 8 pairs of costals, and that the pit in the second peripheral
was for the reception of a process of the hyoplastron. Baur examined also Cope’s types of
the species of Osteopygis, Propleura, and Catapleura and concluded that there were no generic
differences among them.

Baur’s results respecting the number of costals have been confirmed by Wieland. Never-
theless, Wieland adopts Cope’s genus Propleura. He holds that Propleura differs in having
costo-peripheral fontanels, conical rib-pits, and humeri grooved on their distal ends.

So far as concerns the grooving of the distal articular ends of the humeri, the present
writer does not believe that enough is known about the humeni, not only of the species of the
group in question but of the living species, to justify the use of the character proposed by
Wieland to separate genera. Among species of Testudo it is found that the distal end of the
humerus of many, perhaps of most, is smooth and rounded; but that of Testudo orthopygia
has a broad trochlear groove.

ANALYSIS OF THE SPECIES OF OsTEOPYGIS.

1. All the peripherals sutured to the costals (Osteopygis).
A. Posterior peripherals emarginate; upper borders of peripherals not notcht by the
rib pits; thickness of outer end of nuchal about one-eighth its width. emarginatus
AA. Posterior peripherals not emarginate.
a. Outer end of nuchal about one-eighth the width in front; upper borders of

peripherals notcht by rib-pits . : gibbt
aa. Thickness of outer end of nuchal about one-sixth its width in iron upper
borders of peripherals not notcht by rib-pits. ae ae robustus
2. Peripherals 3 to ro inclusive free from the peripherals (Propleura).
A. Hinder peripherals angulated at end of sulcus ; : chelydrinus

AA. Hinder peripherals neither angulated nor emarginate.
a. Rib-pits of eighth and succeeding peripherals flattened; one face or both notcht
by rib-pits. The seventh at least two-thirds as wide as long.
. Bones thick and heavy; thickness of distal end of first peripheral in its length
3.5 times; only upper face of hinder peripherals notcht by rib-pits. . erosus
bb. Boucs thinner, thickness of distal end of first peripheral in its (enech
4.4 times; both faces of upper border of hinder peripherals notcht by
FIDE PLES! visor dis <b <n die epel syseePaya- aca ved sts ee aecrenrape eRe agence le ah memes : borealis
bbb. Bones thinner; thickness of fist peripheral i in its s length 4.4 times; rib-pits
of sixth and seventh peripherals flattened; both faces of peripherals notcht p/atylomus
aa. Seventh peripheral only half as wide as long Res ere sopitus

THALASSEMYDID&, 129

The possession of conical rib-pits on the part of Wieland’s Propleura borealis, if a good
generic character, removes it from Propleura, for the type of the latter, P. sopita, has the pits
in the hinder peripherals all flat. This statement is true as regards Leidy’s type of his Chelone
sopita and of Cope’s specimen, now regarded as belonging to Osteopygis borealis.

There remains therefore only the presence of the costo-peripheral fontanels to separate
Propleura from Osteopygis. This is one of those characters which can not be sharply defined
and which may be expected to exhibit in closely related species all gradations. We can not
be sure that at any time a species may not be found in which a number of the lateral peripherals
are joined suturally with the costals, while others are free. Indeed, we can not be certain that
in some of the described species of Propleura some of the lateral peripherals did not become
sutured to the contiguous costals. An aged Colpochelys kempi has a perfectly solid carapace.

Therefore, until better characters have been proposed for the separation of Osteopygis
and Propleura, the present writer prefers to employ only the former name.

Osteoygis emarginatus Cope.
Text-figs. 134-141.

Osteopygis emarginatus, Cope, Proc. Acad. Nat. Sci., 1868, p. 147 (nom. nud.); Cook’s Geol. New Jersey,
1868 (1869), p. 735 (nom. nud.); Amer. Naturalist, 111, 1869, p. 89; Ext. Batrach., Reptilia, Aves
N. A., 1869, pp- 135, 136, 235, plate vii, fig. 3; Vert. Cret. Form. West, 1875, p. 259.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 441.

Osteopygis platylomus, Cope, Ext. Batrach., etc., p. 134, fg. 39 in part.

The two specimens described by Cope under this name are in the American Museum of
Natural History. Both had been discovered in the upper bed of greensand of the Upper
Cretaceous, at Barnesboro, Gloucester County, New Jersey. The bones figured by Cope

betes |

We =

Fic. 134.—Osteopygts emarginatus. Nuchal, right first peripheral, and portions of first
costals. 3. No. 1485 A. M.N.H.

¢. p. 1, First costal bone; nu.p, nuchal bone; nu.s, nuchal scute; per. 1, first peripheral.

belong to the second individual described by him. This is in the American Museum and bears
the number 1485.
There is, however, some doubt attached to the peripheral which furnisht Professor Cope s
figure 3c. In his explanation of the figure, Cope says that it is the tenth of the left side.
In reality, it is the eighth. He states that the eleventh peripheral of the right side is present, but
it is not in the collection. It seems probable that the one he called the eleventh 1s the same one
he called the tenth of the left side. On the bone there has at some time been written, probably

9

130 FOSSIL TURTLES OF NORTH AMERICA.

by Cope,“ 10 R,” but the digit on the right had evidently been changed from “1” to “‘o” and
an “LL” to an “R.” Finally ink lines had been drawn across these characters and “8”
written near by. These changes indicate that originally Cope regarded the peripheral as the
eleventh; that before he went into print he came to regard the bone as the tenth; and
that at some later period he became convinct that it was the eighth. The measurements
of the bone do not at all agree with those of the tenth peripheral of Cope’s first specimen,
but they do agree quite closely with those of the tenth of the second.

Cope (his plate vii, fig. 3a) has represented the nuchal, the right first peripheral, and the
proximal end of both first costals. These elements are here shown in fig. 134. The free
border of the nuchal and first peripherals is obtuse. At the midline, back from the free
border, the thickness is 15 mm. ‘The free border of the nuchal is 122 mm. long, in a straight
line. The first peripheral is 65 mm. along the free border, and 48 mm. at right angles with
this. It is 17 mm. thick at the proximal nd (fig. 135) Pal 19 mm. at the distal (fig. 136).
The upper surface is convex, with a low concavity running parallel with and just behind the
free border.

The fifth left peripheral (Cope, pl. vii, fig. 34, seen from the lower and inner faces)
measures 77 mm. along the free border; 58 mm. on the upper face anteriorly, 60 mm. poste-
riorly; 52mm. across the inner face anteriorly, 48 mm. posteriorly. The inner face contains
a large pit, circular in section, for the end of the rib of the third costal. This pit occupies
about one-third the length of the peripheral. The upper face is concave up and down; the
lower face is convex. There was no sutural connection with the plastron, but the upper
border of the upper face was suturally joined to the costal. Fig. 137 represents the anterior
end of this bone; 138 the posterior end. The hinder end of the bone corresponds exactly with
the anterior end of the sixth peripheral of O. erosus.

a) —s »} 38.7 a
j

135. 136.

139. 140. 141.

Fics. 135-141.—Osteopygts emarginatus. Portions of shell. 3. No. 1485 A. M.N.H.

135. Section of proximal end of first left peripheral. 139. Anterior end of eighth left peripheral.
136. Section of distal end of first left peripheral. 140. Hinder end of eighth left peripheral.
137. Anterior end of fifth left peripheral. 141. Neurals.

13

8. Posterior end of fifth left peripheral.

The eighth peripheral (Cope, plate vii, fig. 3c) is nearly plane above. The free border is
mostly missing, but it had apparently about the form shown restored in Cope’s figure. It
was therefore rather strongly emarginated, the bottom of the emargination being at the oni of
the sulcus. The fore- and- aft extent of the bone at the middle of the height is go mm.; the
height from the end of the sulcus, 100 mm. It must have been about 115 mm. high at te ends
of the bone. The greatest thickness at the anterior border (fig. 139) is 24 mm.; on the
posterior border (fig. 140), 22 mm. On the upper border the bone was sutured to the costal
touching it. The rib-pit, mostly in the posterior half of the inner face, 1s 30 mm. long and is
flat. It does not notch the upper face.

The first costals (fig. 134) present only their proximal halves. The greatest width fore
and aft is g7 mm. The thickness in front is 12 mm.; posteriorly, 8 mm. The rib-head was
prominent. In front of the ridge descending from it 1s a rough surface to which was articulated
the rudimentary first rib.

Among other fragments of costals is the distal two-thirds of one, probably the fourth. It
is possibly the one mentioned by Cope as having a width of 3 inches and 2 lines, this being the

THALASSEMYDIDZ. 131

width not far from the distal end. Its thickness is about 9 mm. It is interesting, because it
shows plainly that it was articulated suturally with the contiguous peripheral. Fhe bone is
traverst longitudinally by a deep sulcus. Its surface is pitted just like a costal of O. erosus.

The neural figured by Cope (fig. 141) is present, as well as fragments of two others. The
one figured is 55 mm. long and 36 mm. wide, deeply notcht in front, and crost behind by a
transverse sulcus. It is probably. one of the more posterior neurals, the seventh or the eight.

The surface of the anterior bones of the carapace is relativ ely smooth. The fifth peripheral
is somewhat pitted, but the result probably of accident.

The nuchal scute measures 60 mm. in front, 110 mm. behind, and 25 mm. fore and aft.
The first marginal measures 52 mm. along the free border and 39 mm. across the end next the
second marginal.

The first vertebral had a width anteriorly of 185 mm. and a length of 82 mm. The second
vertebral appears to have been about 75 mm. wide. No trace is seen of the costo-marginal
sulcus on the upper border of the fifth peripheral; but doubtless on the sides of the shell the
sulci followed closely the costo-peripheral sutures. On the eighth peripheral the costo-mar-
ginal sulci lie from 12 mm. to 25 mm. below the upper border of the bone.

The femur is represented by a portion of the proximal end; but the head and both trochan-
ters are missing. The shaft has a diameter of 15 mm.

The first specimen described by Cope bears the American Museum’s number 1344. It
was an individual of almost exactly the same size as that regarded as the type. It furnishes
the nuchal, the first right peripheral, the first, second, fourth, fifth left peripherals, the proximal
half of the first left eect, some other unimportant costal fragments, a part of the right hyo-
plastron, a part of the right hypoplastron, and the greater part of both xiphiplastra. Cope
mentions additional peripherals, but they do not accompany the bones mentioned above, and
have not been recognized in the Cope collection.

That paragraph of Cope’s description which occupies the upper two-fifths of page 137 of
the Synopsis may be regarded as a riddle; for in it Cope constantly compares the species he is
describing with itself. The explanation appears to be the following: With the specimen, in
Cope’s writing, is a label ‘ ‘Osteopygis platylomus, Cope, type: nr. Barnesboro, Gloucester
Co; N. J.” At some subsequent time two pencil lines have been drawn through ‘ ‘platylomus.’
‘Where can be no doubt that the specimen is the one Cope describes as O. emarginatus; and
there can be little doubt that the plastral bones furnisht the right hand portion of Cope’s
fig. 39, said to be that of the plastron of O. platylomus. We may suppose therefore that at one
time Cope regarded this specimen as: platylomus and intended to make it the ty pe of the
species; but coming to see that it was O. emarginatus, a portion of the manuscript was
transferred to the latter species without proper changes.

The parts common to this specimen and the type of the species present no important
differences. The second peripheral is 75 mm. long; 57 mm. at right angles with the free border
and at the proximal end, and 21 mm. thick at the same end. The distal end has a large exca-
vation for the process of the hyoplastron. The fourth peripheral is 67 mm. on the free border,
38 mm. across the lower face. Most of the upper face is broken away. An obtuse keel
separates the upper face from the lower. The inner face of the fifth was more excavated than
in the same bone of the type; and, as Cope states, the pit for the end of the rib is much
smaller.

The bones belonging to this specimen which Cope appears to have employed in his fig. 39 are
the hyoplastron, the hypoplastron, and xiphiplastron of the right side. The figure shows
these bones and those of the type of O. platylomus as seen from above. A fontanel existed in
the midline where it was crost by the hyohypoplastral suture. Where the plastral bones
joined along the midline the sutures are coarse and jagged. ‘The xiphiplastron sent a strong
process into the outer border of the hypoplastron and the latter sent one outside of this into the
xiphiplastron. Just in front of this exchange of digitations the hypoplastron is 15 mm. thick.
At this level the hinder lobe of the plastron was about 165 mm. wide. On the lower side of the
hypoplastron the abdomino-femoral sulcus is seen in the position represented by Cope in his
figure 39. Crossing the xiphiplastron the femoro-anal sulcus falls a little further forward
than represented by Cope in the figure quoted.

None of the bones of this specimen is pitted.

132 FOSSIL TURTLES OF NORTH AMERICA.

Osteopygis gibbi Wieland.
Plate 26, fig. 1; plate 27, figs. 1, 2; text-figs. 142-146.
Osteopygts gtbb1, WIELAND, Amer. Jour. Sci. (4), XVII, 1904, p. 118, plates v—vill and text-figs. 3-7.

The type of this species is No. 783 of the Marsh collection of Yale University. It was
obtained from the upper bed of Cretaceous greensand, at Barnesboro, Gloucester County,
New Jersey, in 1870. It was originally studied by Dr. George Baur (Zool. Anzeiger, xu,
1889, p. 42), who determined from it that Cope had been in error when he stated that the
genus Osteopygis possest 10 pairs of costal plates. Fig. 1, plate 26, is reproduced from a
drawing prepared under Baur’s direc-
tions and shows the nuchal, the periph-
erals, and the pygal as seen from below.
In 1904 the specimen was fully prepared
and the parts put together under the
direction of Dr. Wieland. A number of
the figures made by Dr. Wieland are
here reproduced.

The specimen is the most complete
that is known of any species of the family
and it serves to give us a clear idea of
the form and the constituents of the
shell. It will be observed that the out-
line of the carapace as restored by Dr.
Baur (plate 26, fg. 1) differs from that
as restored by Wieland (text-fig. 142).
Since, however, Dr. Wieland fitted the
costals to one another and to the periph-
erals, and brought the plastron into
relation with the carapace, which Baur
did not do, itis quite certain that the
later restoration is the more accurate
one. It can hardly be wrong except in
small details. Fig. 143 shows the shell
from the side.

In form the carapace is elongated

Fic. 142.—Osteopygis gibbi. Carapace of type. X#. oval, rounded in front and somewhat
; ; ; pointed behind. It is somewhat deprest
c. 8. 1, first costal bone; m. s. 12, twelfth marginal scute; 1.1, : : ES

first neural; 7.8, eighth neural; 2u.p,nuchal bone; »xz.s, nuchal and especially the hinder peripherals look

scute; py, pygals spy.1, spy.2, spy.3, suprapygals. more upward than outward. The length

ina straight line is given as 690mm.; the
extreme width, as about 580 mm. The nuchal bone is 127 mm. wide in front and has a maximum
widthof145 mm. Its length is75mm. The dimensions of the neural bonesare shown in the table.

The eighth neural is apparently followed by a small first suprapygal. ‘This is succeeded
by an irregularly shaped second suprapygal, 60 mm. long and 162 mm. wide. Behind this
comes the posterior suprapygal, which has a length of 60 mm, and a width of 97 mm.

All the peripherals are suturally articulated with the contiguous ends of costal bones, except
the eleventh, which articulates with the suprapygals The peripherals, except the first, second,

Neural. Length. Width.
1 95 41
2 65 47
3 65 47
4 65 43
5 504 37
6 45+ 33
e 45+ 30 <<
8 65+ 384

Fic. 143.—Osteopygis gibbt. Shell from left side. 4.

THALASSEMYDID. 133
and the eleventh, have each a pit in the inner face to receive the end of a rib extending beyond
the costal ea In the hinder peripherals these pits are flattened; also they produce notches
in the upper face of a number of the hinder peripherals, as they do in O. borealis. This

deficiency in the upper wall of some of the pits

| it eee Width. ae marks one difference between this species and
Perip eral. vength. Thickness. (Olte 0 : : = pay
em cretenice O. emarginatus, the type of the genus. The
inner face of the second peripheral has a large
; ae be 7 pit for the reception of the outer anterior exten-
iy 32 Ga a of sion of the hyoplastron. The inner face of the
3 75 os . - third, fourth, fifth, sixth, and seventh periph-
76 Te} wa
2 A av a erals is broad and longitudinally excavated.
6 85 62 4 These bones have thus three borders, the outer,
| z 92 - - ; or free border; the upper border, which articu-
s 95 e 26 e . re i
i as ee Rae i. lates with the costals; and the inferior border,
| 10 90 11 14 which comes into contact with the plastron. In
it 83 110

the anterior end of the eighth there is a cavity
into which the outer posterior process of the
hypoplastron projects. The inner face of the peripherals behind the eighth becomes narrow
and curves into the lower face. Thus, these hinder peripherals are thin and wedge-shaped.
The dimensions of the peripherals are shown in the table herewith.

The acute free border of the hinder peripherals may be traced forward on the more anterior
ones, where it forms a keel separating the upper face from the lower. The peripherals, from
the seventh to the eleventh inclusive, are slightly concave on the

|Vertebral.| Length. | Width, | UPPer surface. ;
Che pygal bone measures about 85 mm. along the free border

| and has a height of about 75 mm.

| ' be re The sulci between the various scutes of the carapace are
3 | 133 115 rather deeply sunken. The dimensions of the vertebral scutes
4 142 435 are given in the table.
5 sid The hinder border of the fifth lies on the posterior supra-

pygal. The supracaudals join along the midline a distance of
7o mm. and each is 40 mm. wide. ‘The costo-marginal sulci lie w holly on the peripheral bones,
close to their upper margins, except at the rear, as just noted.
There are four pairs of costal scutes.
The surface of the bones of the carapace is usually smooth; but in places there appear
striations, which are directed outward and backward. ‘There are no pits.

ME epi NN ar

“yy
i
>

| hypo

146.

Fics. 144-146.—Osteopygts gtbbi. Plastron and limb bones of type.

144. Plastron. X$. ab, abdominal scute; am, anal scute; ent, entoplastron ; epi, epiplastron; f, f, median and
posterior fontanels; fer, femoral scute; hyo, hyoplastron; infm?, supposed inframarginal scute; pec, pec-
toral scute; x/ph, xiphiplastron.

145. Humerus, dorsal surface. x}. 146. Femur, dorsal surface. +.

134 FOSSIL TURTLES OF NORTH AMERICA.

Relatively to the carapace the plastron (plate 27, fig. 2; text-fig. 144) is smaller than in
Caretta caretta. Nevertheless, the connection between the borders of the plastron and the
peripherals is more extensive than in the genus just mentioned, extending from the second to
the eighth peripherals. The outer anterior prolongation of the hyoplastron reaches forward
as far as does the anterior lobe, and the outer posterior prolongation of the hypoplastron
extends backward nearly as far as does the hinder lobe. The hyoplastron sends a process into
the second peripheral, and the hypoplastron has its hinder prolongation inserted in an excava-
tion of the seventh and eighth peripherals. In the fourth and sixth peripherals are small
pits for digitations of the plastral bones. The median longitudinal suture is a coarse one.
There is a median fontanel at the crossing of the hyohypoplastral suture and the median
longitudinal. On each side, at the ends of the hyohypoplastral suture, is another fontanel.
A fourth is found on the median line just in front of the xiphiplastra.

The epiplastra are narrow bones which have a length of about 85 mm. and a width of

15 mm. The entoplastron is only in part preserved. It appears to have been 85 mm. long
and 59 mm. wide.

The least width across the bridges is 114 mm. ‘The hinder lobe is much reduced, leaving
free play for the hinder limbs. The xiphiplastra are 185 mm. long and 55 mm. wide.

The sulci of the plastron are very obscure, but Wieland appears to have mapt them
correctly. ‘There were quite certainly inframarginals on the outer ends of the bridges. The
sulcus between the gular and the humeral scutes has not been observed; nor that between the
humeral and the pectoral. Wieland calls the pectoral scutes the fipierals: the abdominals,
the pectorals; the femorals, the ventrals; the anals, the femorals. The abdominals have a
width, at the midline, of about 65 mm.; the femorals, a width of 78 mm.; the anals, a width
of nearly 150 mm.

Wieland has figured the humerus (fig. 145). The total length is 145 mm.; the short
diameter of the flattened shaft, 18 mm.; the long diameter, 21 mm. It resembles the humerus
of Chelydra. The angle between the planes of the ulnar and radial crests is obtuse. The
distal end of the bone is grooved, as in some species of Emydide and of Testudinide. The
ectepicondylar passage is a deep perforation. The femur has a length of 150 mm., therefore is
longer than the humerus. It resembles that of Chelydra, except that the distal end is grooved.
In this respect too it differs from the femur of O. borealis.

Wieland has described and figured the ulna, the tibia, 2 metatarsals, and 1 cervical
vertebra. Fig. 146, from Wieland, represents the femur.

This species is most nearly related to the type of the genus, Osteopygis emarginatus
Cope. The latter differs in having the posterior peripherals emarginated on the free borders
at the end of the intermarginal sulci, in not having the upper borders notcht so as to expose
the end of the rib, in having a shorter first vertebral scute, and apparently in having narrower
second and third vertebral scutes. The type of O. emarginatus is only slightly smaller than

the type of O. grbb:, the nuchal of the former measuring along the front 122 mm.; that of

the latter, 127 mm. The first vertebral scute of O. emarginatus is close to 82 mm. long; that
of O. gibbi, 110 mm. The width of the second vertebral of O. emarginatus, at the anterior
end, is close to 75 mm.; that of O. gzbbi, about 102 mm.

Osteopygis robustus sp. nov.
Figs. 147-151.

In the American Museum of Natural History is a lot of bones which is accompanied by a
label written by Professor Cope, stating that they were found at Birmingham, New Jersey,
that he regarded them as belonging to Osteopygis emarginatus, and that he received them
November 13, 1870. Those bones which can be safely regarded as belonging to one individual
are the nuchal, the first and second peripherals of both sides, the tenth and eleventh peripherals
of both sides, the fourth costals of both sides, the left fifth, the left seventh and the eighth, and
the proximal, end of the right eighth. There are also fragments of other costals of unde-
termined position. To this specimen is given the number 2360.

A comparison of these bones with those of the types of O. emarginatus and O. gibbi makes
it evident that they belong to a hitherto undescribed species. The differences will appear as we

THALASSEMYDID&. 135
progress with the description. “That which especially strikes one is the greater thickness of
the bones here described, as compared with corresponding ones of O. emarginatus and O. gibbr.
The three types are of nearly the same size. The dimensions of various bones are given in
the following table. Except the length, the dimensions of each bone are taken at the anterior
end. The thickness of the nuchal is taken
at the midline. The columns headed by

Element. Length. Height. Thickness. : J
1 belong to O. emarginatus; those by 2,

Pe etal eel ala | 2 | 4 | te Ougrbde: those by 3, to O.robustus.
The nuchal bone (fig. 147) appears
| Nuchal .... | 122 | 127 | 125 vss js. | T§ 16 20 to have extended backward further in
Peripheral 1 = 63 79 78 | 48 60 60 19 17 30 : : : : : “os
5 acalleraee levee Ve ea lie i >» this than in the species with which it is

2 82} 83) 4 50 | 60 ZO: | 21 | 26 : :
Io go 89 111 110 14 18 compared above. The hinder portion
u 83 90 110 |Loo+ '9 of the bone is broken away, but the por-

Pygal oes 83 96 71 | 68 20 /

tion remaining is 80 mm. wide antero-
posteriorly. The nuchal of O. emargina-
tus measured in the same place gives us 70 mm.; the nuchal of O. gibbi has a length of 75 mm.
Fig. 148 is a section at the articulation between the nuchal and the first peripheral.

The upper border of the first peripheral, articulating with the first costal, has a thickness
of 10 mm. (fig. 148). The left second peripheral lacks the hinder end; and that of the right
side has the hinder end of the inner face so eroded that it does not show the pit for the hyo-
plastron. These peripherals articulated with the first costal. The other peripherals are
missing to the ninth, and of these only unimportant fragments remain. The tenth and eleventh
(fig. 149) are nearly plane above, or slightly convex. The rib-pits are flat; and that of the

we

Fic. 147.—Osteopygts robustus. Nuchal bone and first peripheral right and left, of type.

nu. s, nuchal scute; per. 1, first peripheral.

tenth is rooft over to the articulation with the eighth costal plate with bone 7 mm. thick. It is
possible, but not probable, that the ninth peripheral had its upper border notcht by the rib-
pit, as it is in the case of all the hinder peripherals of O. grbbr. No rib entered the eleventh
peripheral. This and the pygal articulated suturally with the last suprapygal. The upper
sutural border of the pygal is 13 mm. thick. The free borders of the tenth and eleventh
peripherals are acute. Fig. 150 represents the front end of the tenth peripheral. There are no
indications of emarginations of the free border such as are supposed to characterize O. emar-
ginatus. The pygal (fig. 149) is notcht somewhat at the midline. Fig. 151 is a section thru
the middle of the pygal.

There are present what are regarded as the proximal and the distal portions of the left
fourth costal; the proximal end of the right fourth; the left seventh, lacking most of the front
border; the left eighth entire; and the proximal end of the right eighth. These bones are all
thick. Where the suture with the neurals is shown the bone is 10 mm. or If mm. thick. At
the middle of the length of the costals the sutural edges are about 6 mm. thick. The distal
ends of costals four and five were suturally joined to the corresponding peripherals; and the
same is true of the seventh and the eighth. The fourth costal has a width of 62 mm. at the
costo-vertebral sulcus and 70 mm. at the distal end. The end of the rib of this costal projects
from near the front border of the distal end, as it appears to do, likewise, in O. gibb:. The width

130 FOSSIL TURTLES OF NORTH AMERICA.

of the fifth costal at the distal end is 77 mm. At the costo-vertebral sulcus the seventh and
eighth costals (fig. 149) are each 39 mm. wide. The eighth is 47 mm. wide at the distal end.
On the inferior side of the eighth costal is seen the base of the small rib-head. Behind this is
the co-ossified end of the vestigial tenth rib.

The surface of the bones of the carapace is almost everywhere more or less uneven. On
the nuchal and the anterior peripherals the areas occupied by the scutes are tumid, and the
sulci run in deep and broad valleys. The same remarks apply to the dorsal region of the
carapace, so far as represented. The sulci of the distal portions of the costals and of the hinder
peripherals are deeply imprest.
_ VS \ The upper surfaces of the hinder
y 3 \ peripherals are more or less undu-

: i y \ y lating.
148, é we The nuchal scute (fig. 147) is

\ smaller than that of either O.

_— —- emarginatus or O. gibb1; its width

, ; av anteriorly being 47 mm.;_poste-

ops i riorly, 80 mm.; its fore-and-aft

YO Sa 7 A extent, 24 mm. The first marginal

per.9 \ er, is 62 mm. along the front; 30 mm.

5 A where it joins the nuchal; 45 mm.

Sg where it joins the second marginal.

\ On the tenth peripheral the costo-

pe — marginal sulcus runs 30 mm.

: } below the upper border of the

eas 150. bone. At the midline behind, the

\ 4A cra sulcus crosses on the hinder supra-
< / | a pygal.

ee peti ; \ The anterior vertebral scute

had a width of about 200 mm.

py ‘’ On the fourth costal the costo-

{

perso

ee nN J vertebral sulcus crosses the bone
ees tL ; at a distance of about 44 mm.
eo. from the neural border. Esti-

ISI. : mating the width of the neural at

Fics. 148-151.—Osteopygis robustus. Costals, peripherals, 45 mm. the width of the third ver-
and pygal of type. tebral would be about 135 mm.

148. Section at proximal end of first peripheral. 3. The fourth vertebral, at the ante-

149. Right seventh and eighth costals, hinder peripherals, and pygal. x4. rior border of the seventh costal,
150. Section of anterior end of tenth peripheral. xh. to have b 5
151. Section along middle of pygal. 4. ep pests YEN WS och Ue inete)
mm. wide. That of O. g1bbi was
about 135 mm. wide. The fifth vertebral had a width posteriorly of 190 mm. Its length was
close to 155 mm.

On account of the common feature of sutural union of all the peripherals with the costals,
this species needs comparison only with O. emarginatus and O. gibb1, and such comparisons
have already been made.

Osteopygis chelydrinus Cope.

Plate 23, figs. 4-7; plate 28, figs. 1-4; text-figs. 152-154.

Osteopygis chelydrinus, Cope, Proc. Acad. Nat. Sci. Phila. 1868, p. 147 (nom. nud.); Geol. New Jersey,
Cook, 1869, Append., p. 735 (nom. nud.); Amer. Naturalist, m1, 1869, p. 89; Ext. Batrach..
Reptilia, Aves N. A., 1869, pp. 135, 138, plate vii, fig. 8—Hay, Bibliog. and Cat. Foss. Vert.
N. A., 1902, p. 441.

Catapleura chelydrina, Corr, Vert. Cret. Form. West, 1875, p. 259.

In his Synopsis of the Extinct Batrachia, Reptilia, and Aves of North America, Professor
Cope stated that this species was represented by “‘only 10 marginal plates more or less perfect
and some costals”; also that the species was referred to the genus Osteopygis because the

THALASSEMYDID&. 137

“anterior rib-bearing marginal bone has been united with the middle disk by suture.” In the
Vertebrata of the Cretaceous Formations of the West he says that the reference of the species
to Catapleura is not final, ‘as the anterior costals and marginals are not known.”

Of Cope’s type only a single bone was figured, the peripheral which he regarded as doubt-
fully the tenth of the right side. In the Cope collection of fossil reptiles in the American
Museum of Natural History this figured bone is found (plate 23, figs. 4, 5; text-fig. 152). It is
accompanied by a number of other bones, some of which are markt in such a way that it is
evident that Cope intended to figure them; besides other bones which probably do not belong
to the species. It is evident that several of the bones belonging to the type have been fost,
while it is probable that a few of other species have become mingled with it. It is certain,
therefore, that our future identification of the species in new materials must depend princi-
pally on the figured peripheral. The catalog number is 1131. Cope’s label shows that the
type came from Barnesboro, New Jersey.

It is evident that the bone in question does not belong to the right side. Usually in the
related species the pit for the rib lies nearer the hinder end of the bone and the sulcus reaches the
upper border in front of the pit; but if this bone is assigned to the right side, this pit will lie
nearer the front end and the sulcus will fall behind the pit. The bone appears to be the seventh
of the left side. It resembles closely the seventh of a specimen of O. borealis, but with specific
differences.

Cope has given the length and breadth of this bone as being respectively 2 inches g.3 lines
(70 mm.) and 3 inches 2 lines (80 mm.), by length meaning evidently the distance from the
suture with the bone in front to that with the bone behind, and by width the distance from the
costal border to the free border. These dimensions will vary somewhat with the points selected

152: , a
oe

153;
154.

Fics. 152-154.—Osteopygis chelydrinus. Sections of peripherals of type. X#.

152. Section of seventh peripheral. 153. Section along intermarginal sulcus of second left peripheral.
154. Section at front of third peripheral.

on the borders. The free border of the bone originally measured at least 75 mm.; the
upper border now measures 53 mm.; and the anterior border 80 mm. Cope states that
these peripherals are remarkable for their shortness, but a careful comparison hardly confirms
this statement. A more certain character appears to be found in the thickness of the bone.
The thickness of the end regarded by the present writer as the anterior is slightly more than
23 mm.; that of the other end is 19 mm. This is considerably more than the thickness of even
the eighth peripheral of any known species, regard being had for the other dimensions.

Another character has been noted by Cope, the angulation of the free border, at the end
of the epidermal sulcus. The angle included between the two portions of this border is about
130°. In other species the border is nearly straight or slightly concave where met by the
sulcus. Usually in turtles, when the border of the carapace is notcht, the sulcus ends at the
notch. Whether or not the angulation of the border is found in all of the posterior peripherals
we have now no means of determining; but in all probability all were angulated.

The pit for the extremity of the rib is elliptical in section and 29 mm. deep. The horizontal
diameter is 15 mm.; the perpendicular, 11 mm.

The bone may be regarded as having three faces, an upper, a lower, and an inner. The
upper is slightly concave along a line from the costal to the free border. The epidermal
sulcus is broad, but rather shallow. The sulci between the marginal scutes and the adjacent
costal scutes appear to have run along close to the costal border. The lower face is consid-
erably convex along a line from the free to the costal border. On this face there is a broad
shallow sulcus, corresponding to the one above. The inner face contains the rib-pit. This
face is concave and irregular, with the upper portion overhanging the lower. The bone did
not form a sutural connection with the border of the first costal plate.

128 FOSSIL TURTLES OF NORTH AMERICA.

The second peripheral of the left side (plate 23, figs. 6, 7; text-fig. 153) measures 64 mm.
along the free border and has a minimum width of 45 mm. From the thin costal border the
bone thickens rapidly on the lower side until a thickness of 16 mm. is attained at the proximal
end of the bone and of 19 mm. at the distal end. The inner half of the lower surface is a little
concave; the outer half very convex and rising to meet the upper surface. The anterior half
of this face looks forward. The distal end oF the lower surface is deeply excavated for the
outer anterior angle of the hyoplastron. There can be little doubt, it is believed, that this is
the peripheral w hose length and breadth Professor Cope has given respectively as 2 inches
6 lines and 1 inch g lines. It was evidently suturally united with che first costal plate.

The third peripheral (plate 28, figs. 1, 2; text-fig. 154) of the right side is present. It has
an extent of 61 mm. along the free margin and 42 mm. at right angles with this. It presents
three faces, an upper, an inner, and a lower. The inner face is concave and is to a great extent
occupied by an excavation for the reception of the rib of the first costal plate. Its width is 42
mm. where widest. It is separated from the lower face by a sharp ridge.

The upper face is nearly plane except in front where it rises to the summit of a ridge,
on which it joins the lower face. A sulcus crosses this face nearer the proximal end. Its hinder
border is grooved by the sulcus between the marginal and the first costal scute. The maximum
width of this face is 34 mm. The lower face is quite convex vertically, the upper portion of it
looking upward and forward, the remainder downward and forward. Its width is 23 mm.
What distinguishes these anterior peripherals especially is the carina where the upper face
meets the lower.

Accompanying the bones above described is the lower jaw of a turtle, consisting of the
united dentaries (plate 28, figs. 3, 4). This has written on it, doubtless by Professor Cope, the
name “‘chelydrinus.”” It is hardly conceivable that he would not have mentioned this j jaw had
it been present when he described the other bones. It is difficult to understand why he should
have referred it to this genus and species without some good reason, when it would naturally
have been placed in his genus Lytoloma. It is possible that he discovered after his description
had been publisht that it belonged with the type of O. chelydrimus, yet he does not mention
the lower jaw in his reference oe the species to Catapleura 1 in 1875; but he does give, under
the genus Osteopygis, a description of the lower jaw, which description might have heen based
on the j jaw now under consideration; and no other jaw is known which ae been referred to
Osteopygis. The matrix clinging to the jaw is exactly like that on the peripherals. The
matter is very obscure.

This jaw resembles that of Lytoloma angusta, but there are at least specific differences.
Figures of it are here presented. In the j jaw called“ “chelydrinus” the outline is almost that of
a semicircle whose center lies a little behind the posterior end of the symphysis and whose

radius is 38 mm. In Lytoloma angusta the outlines of the jaw run in nearly direct lines from

the front of the masseteric fossa to near the tip of the jaw. In the jaw “‘chely ‘drinus”’ a line
joining the mental foramen, lying in the front of the left masseteric fossa, with that of the
right side falls at or a little behind the posterior end of the symphysis. In the type of Lyto-
loma angusta the same line falls in front of this end of the symphy sis a distance equal to
one-sixth the whole length of the symphysis. In “‘chelydrinus” the symphysis forms 47 per
cent. of the width of the jaws at the front of the masseteric fossa; in Lytoloma, 58 per cent.
It is quite evident, therefore, that the jaw labeled ‘“‘chelydrinus” represents a species distinct
from Lytoloma angusta. It differs fully as much from the jaw figured by Wieland under the
name Lytoloma angusta, here described as Lytoloma wielandi.

Osteopygis erosus Cope.

Plate 26, fig. 2; text-figs. 155-162.

Osteopygis erosus, Cope, Vert. Cret. Form. West, 1875, p. 258.—Hay, Bibliog. and Cat. Foss. Vert. N.A.,
1902, p. 441.

The type of Cope’s Osteopygrs erosus is now in ie American Museum of Natural History
and bears the number 1130. The specimen appears to have been discovered in the upper bed
of Cretaceous greensand, at Barnesboro, New Jersey, in 1869. It was probably found too
late for inclusion in the monograph of 1869 and was reserved for publication until 1875. The

———

THALASSEMYDID&. 139

type specimen comprises all the peripherals of the left side, except the third, tourth, fifth, and
eleventh; the second, fourth, eleventh and half of the ninth of the right side; the first left
costal, lacking the distal end; the distal end of the first right costal, and many fragments of
other costals; two neurals and a portion of a suprapygal; some fragments of the plastron;
and two vertebra. Cope mentions five vertebrz.

An estimate, based on the dimensions of the peripherals, shows that the carapace was
probably slightly shorter than that of the type of
O. gtbbi; that is, it was about 740 mm. long in a
straight line.

Professor Cope stated that this species is
abundant in the upper bed of Cretaceous green-
sand at several localities in New Jersey, but the
present writer knows of but one other specimen.

The nuchal bone is missing, but its form and
proportions were probably similar to those of the
nuchal of O. emarginatus. The following table
presents the dimensions of the peripherals (plate
26, fig. 2; text fig. 155). The length is taken
along the free border. The height is the distance
at the anterior end of the bone, from the free
border to the costal border. The thickness is the
greatest taken at the anterior end of the periph-
eral. Where a definite inner face presents itself,

First and second peripherals and first costal of type. as from peripherals 4 to 8, the thickness is

X}. First peripheral at the right. replaced by the dimensions of these faces. The

dimensions of the hinder end of any bone are the same as the dimensions of the front end of
the succeeding bone.

The free borders of the first (fig. 156) and second (fg. 157) peripherals are thick and
obtuse. On the fourth there is a subacute, slightly upturned free edge, which may be traced
forward as an obtuse keel, even to the first peripheral. On the fourth peripheral (fig. 158)
the upper and the lower faces form an angle with each other greater than a right angle; but on
the sixth (fig. 159) this is already less than a right angle; and more posteriorly the two faces
E become more nearly parallel (figs. 160,

Width. 161). The upper faces of the four ante-
rior peripherals are irregularly convex;
those of the sixth and seventh are some-
what concave; those of the others are

Fic. 155.—Osteopygts erosus.

Peripheral. Length. Height. | Thickness.
Lower face. Inner face.

I 83 61 21

5 81 so 5A nearly plane.

3 : st 31 - In the hinder end of the second
is a - a e peripheral (fig. 157) is a deep pit for the
6 83 654 i 57 47+ anterior prolongation of the hyoplas-
i 85 ze ‘Y = tron. Cope thought that this pit was
5 ak eae 8 it * for the rib-end of the first costal. The
10 95 97 17 c - pits in the greater number of the periph-
8 got 105+ 7 erals are circular in section. Those of

= 7 the ninth, tenth, and eleventh are fat-

tened. In the last-mentioned cases the pits produce notches in the upper faces of the periph-
erals. The anterior end of the inner face of the eighth peripheral is deeply excavated for the
posterior outer angle of the hypoplastron. The inner face of the seventh is considerably
excavated for the same purpose. Several shallow pits appear along the lower borders of the
inner face of the sixth and seventh peripherals for digitations of the plastron. There was no pit
in the eleventh peripheral. This bone had a thickness of 18 mm. where it joined the pygal.
As regards the connection of the peripherals with the costals, we appear to have the fol-
lowing: The first and second peripherals were closely sutured with the first costal. ‘The distal
end of this costal shows that at least the anterior half of the third peripheral was sutured with
it. The anterior end of the upper border of the fourth costal is smooth; the posterior two-

140 FOSSIL TURTLES OF NORTH AMERICA.

thirds is rough, indicating sutural union with the second costal. Probably the sixth peripheral
was free from union with a costal; also the seventh. The hinder portion of the border of
the eighth peripheral is rough, as if it had formed a suture with the contiguous costal. The
upper borders of the succeeding two peripherals are broken away, so that we can not determine
their mode of connection with the costals. The eleventh peripheral articulated suturally with
the suprapygals.

The first costal bone (fg. 155) has an extreme width of 104 mm. The outer end of its
rib was inserted in the third peripheral. In front, where it articulated with the nuchal, it 1s
10 mm. thick and the suture is beveled in a manner to show that the nuchal slightly overlapt
the costal. The hinder border is 9g mm. thick. Another costal has a width of 72 mm. anda
thickness of 10 mm. The rib is not conspicuous on the under side.

The two neural bones are probably the third and fourth (fg. 162). Measured along the
midline the bone anterior is 84 mm. long, while the width is 42 mm. The anterior end is
narrowly notcht for the reception of the preceding neural. ‘There is no definite angle between
the antero-lateral and the postero-lateral sides. The other neural is 61 mm. long and 40 mm.
wide.

The sulci which mark the boundaries of the horny scutes are extremely distinct, becoming
sometimes deep and broad. The outer end of the first marginal is 46 mm. wide. The second

158.

159- 162. 161.

Fics. 156-162.—Osteopygts erosus. Portions of shell of type. No. 1130 A. M. N. H.

156. Section of first peripheral. 3. 159. Section at anterior end of sixth peripheral. 3

157. Hinder end of second peripheral. 3. Shows 160. Section at middle of length of eighth peripheral. 3.
pit for process of hyoplastron. 161. Hinder end of tenth peripheral. 3.

158. Section of fourth peripheral. 3. 162. Two neurals. 4.

extends from the free border 55 mm.; the third, 41 mm. Behind this, the costo-marginal
sulci run along on the upper borders of the peripherals. From the upper borders of the
eleventh peripheral the sulcus crost on the last suprapygal, not coming into contact with the
pygal. The first vertebral scute appears to have been as in O. emarginatus. Its width can
not be determined.

All the bones of the carapace are more or less rough and uneven, but that which especially
distinguishes them is the presence of numerous pits. These vary in size, depth, and distri-
bution. The average diameter is about 5mm. These pits are relatively few on the anterior
portion of the carapace. They are numerous on the costals, and present commonly on the
peripherals (plate 26, fig. 2).

The fragments of the plastron furnish no useful information,

Accompanying the bones are a scapula and an ilium. The upper end of the scapula
and the distal end of the procoracoid process are broken off. The remainder of the bone
resembles the same bone in Caretta caretta. The ilium is broader and flatter above than in the
genus just named.

THALASSEMYDID&.

141
Osteopygis borealis (Wieland).
Plate 26, fig. 3; text-figs. 163-171.
Osteopygis sopita, Cope, Proc. Acad. Nat. Sci. Phila. 1868, p.147; Vert. Cret. Form. West, 15 755 p- 258.—

Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 441.
Propleura sopita, Cope, Cook’s Geol. New Jersey, 1868 (1869), p. 735; Amer. Naturalist, t11, 1869, p. 88;
Ext. Batrach., Rept., Aves N. A., 1869, pp. 140, 235, p. Vii, figs. 4-7, text-fig. 39. ,
Propleura borealis, W1ELAND, Amer. Jour. Sci., (4) xv, 1904, p. 1209, pl. ix; thid, XVIII, 1904, p. 190,
fig. 4.

Under Osteopygis sopitus the writer has presented his reasons for concluding that Cope
erred when he referred to that species the specimen of Osteopygis which he described in his
Extinct Batrachia, etc., p. 140, plate vii, figs. 4-7.

The type of Wieland’s Propleura borealis is No. 778 of the Marsh collection, in the Yale
University museum. It was obtained in 1870, from the upper bed of greensand, near Horners-

isch

Fic. 163.—Osteopygis borealis. The humerus, and parts of carapace, plastron and pelvis.» $.

C. p. 1, ¢. p-2, etc., costal plates; um, humerus; /yo, hyoplastron; hypo, hypoplastron; #/, iltum; isch, ischiusn;
n.1,m,2, first and second neurals; nu. p, nuchal plate; pub, pubis; x/ph, xiphiplastron. 1, 2, 3, etc., right
and left peripherals.

town, Monmouth County, New Jersey. It furnishes the nuchal and the first and the second
neural; the second, third, fifth, sixth, and seventh right peripherals; the first, second,
third, fifth, and sixth left peripherals; the first, second, fourth, and fifth right costals; the first
and second left costals; the right hyoplastron and hypoplastron; both xiphiplastra; the
left humerus; the left pubis and ilium; and both ilia. These bones are in a fine state of
preservation.

142 FOSSIL TURTLES OF NORTH AMERICA.

Wieland suggested that his type might prove to belong to O. erosus. However, the latter
differs in having thicker bones and a longer nuchal. To illustrate this statement we will
consider the seventh peripheral. The length of this is 88 mm., just three-fourths that of the
same bone in the type of borealis, yet the thickness of the inner face is 47 mm.—7 mm. more
than in the latter species. This is too great to be due to age or individual variation. The

= length of the nuchal in borealis is go

Width. mm. This bone is not present in the

Peripheral. Length. Height. ecora a type of erosus, but the left peripheral
ower face.|Upper face. s

—— and first costal show that it extended

backward at least go mm., and it cer-

i 103 6o 23 i i Ks
2 95 60 28 Bi me tainly was still longer. If the animal
3 75 45 - 40 45 had grown to be a fifth or a fourth
: oS <8 - ro ie larger the nuchal would have been
6 104 68 : 60 50 much more than go mm. in length.
7 te es = th ni) The anterior peripherals of O. erosus

are higher than those of the type of
borealis, altho the latter belonged to a considerably larger individual.

On comparing the bones of borealis with those of Cope’s supposed sopitus in the
American Museum of Natural History no important differences are observed. The nuchals
agree. The surface of borealis is marked by pits resembling rain-drop impressions; but the
surface of Cope’s specimen is so markt to some degree, and a larger specimen referred to the
species has such impressions in abundance. Some differences do appear, when careful compari-
sons are made among the measurements of the peripherals, but these fall within a few
millimeters. Greater Oifeceners may be observed between other specimens which are regarded
as belonging to O. borealis. Figures and measurements are presented above of various parts
of Wieland’s specimen. A portion of these are taken from Dr. Wieland’s paper, but most
of them have been kindly furnisht me by the author.

Fig. 163 is redrawn from Wieland’s figure in the American Journal of Science and reduced
by one-fourth making the figures one-eighth the size of nature.

Fa 164a,

Fics. 164-168.—Osteopygts borealis. Peripherals of type. 3.
164. First left peripheral, with section (1642) of the 166. Anterior end of fifth peripheral.
proximal end. In the section the upper surface 167. Anterior end of sixth peripheral.
is directed toward the left. 168. Anterior end of seventh peripheral.

165. Anterior end of third peripheral.

Fig. 164 presents the first left peripheral from above, together with a view of the end
which joins the nuchal bone; figs. 165, 166, 167, and 168 represent the anterior ends respect-
ively of the third, fifth, sixth, and seventh right peripherals.

The length of the first neural is 102 mm.; its greatest width is 55 mm. The first costal
has a maximum width of about 120 mm. The second i is go mm. wide at the costo-vertebral
sulcus. The first vertebral scute is about 285 mm. wide; the second, about 180 mm.

The plastron (fig. 163) in general resembles that of O. gibbi; but the fontanels appear to
have been larger and the bridge was wider. The latter has a width of 138 mm. The whole
plastron had a width, taken across the hypoplastra, of about 520 mm. The hyoplastron
extended forward from the hyohypoplastral suture 138 mm.

THALASSEMYDID&. 143

The humerus (fig. 163, hum) has an extreme length of 170 mm. The shaft dorso-ventrally
is 17 mm. thick. The smooth rounded end is 54 mm. wide. The ulnar crest rises above the
head. Between the plane of the two proximal processes the angle is obtuse.

The pelvis (fig. 163 11, zsch, pub) resembles in general that of Chelydra.

The specimen referred to above as having been described by Cope as Osteopygis sopitus
is now in the American Museum of Natural History and has the number 2351. Tt consists
of peripherals one to four, seven, eight, and ten, of the right side; peripherals one, three to
five, seven, eight, and ten, of the left; the nuchal, the proximal portions of costals one to
four of the left side; one nearly complete costal, perhaps the third of the right side; many
fragments of other costals; a number of plastral bones; parts of both humeri; and a complete
left femur.

Cope has, from this specimen, produced a figured restoration of the carapace (Ext. Batr.
Rept., etc., p. 139, fig. 39). This is represented as having ro pairs of costal plates and a corre-
sponding number of neural bones. It is difficult to understand how that author could suppose
that the rib of the first costal could extend far enough forward to enter the pit in the second
peripheral. Evidently he saw no other possible use for the pit. The eleventh peripheral is
not present. On the tenth is found the number “‘1o,” written in ink; but at that time the
right hand digit ‘‘o’’ was written upon a “1.” Altho on page 235 of the work cited, Cope
concluded that the genus Osteopygis had only nine pairs of costals, he maintained, from exami-
nation of the present specimen, that Propleura had ten pairs. Nevertheless, in his Vertebrata
of the Tertiary, publisht in 1884, he stated that Osteopygrs had 10 pairs and Propleura g pairs.

Cope figured a part of the nuchal,

Width. the first left peripheral, and a part of
Peripheral.) Length. | Height. Thickness. the first left costal. They are refigured

Lower face. Inner face.

(hg. 169, p. 145), with the addition of
fragments overlookt by Cope. The

|
|

: 77 2 e - front of the carapace, along the nuchal,
3 oa 42 39 font was somewhat concave. The free bor-
4 73 36 29 40 ders of the nuchal and the anterior per-
75 ea rt ie ipherals are obtuse and thick. At the
7 2 65+ 57 24 midline the nuchal is 10 mm. thick.
8 go - 16 . - The fore-and-aft length of the nuchal
ne 87 88 aa - - is 78 mm.; its width along the free bor-

der was close to 120 mm. The border

which joined the first neural is only 5
mm. thick. The table gives the dimensions of the peripherals, the measurements, except
the lengths, being taken at the anterior ends. In a few cases a dimension has been taken
from the contiguous end of the peripheral in front.

The first peripheral was suturally joined to the first costal; probably also the second, but
the border is missing. It is probable that all the other peripherals to the eleventh were free
from the contiguous costals, but the upper border of the fifth has some appearance of having
formed a suture. The upper faces of the anterior peripherals are nearly plane. Beginning with
the fifth, the upper faces are more or less concave from the free edge to the costal border. The
hinder peripherals have a thin acute border and this may be traced forward, but becoming less
acute, to the first peripheral. In the hinder end of the second peripheral, in the inner face, is a
pit, like a deep thumb impression, for the anterior prolongation of the hyoplastron. The other
peripherals have each a pit for the end of the corresponding rib. They are at the middle of the
length of the inner face. Most of them are circular in section, but those of the last two or three
peripherals are somewhat flattened; and they notch the upper face of the bone.

The first costal has a maximum width of 98 mm. The second is 66 mm. wide; the third,
60 mm.; the fourth, 46 mm., all measured at the costo-vertebral sulcus. At the sutural
borders these bones are 5 mm. thick.

The surface of most of the bones is more or less roughened; and on many of them, espe-
cially the costals, there are present scattered pits, each about 3 mm. in diameter. These pits
are less conspicuous on the hinder peripherals.

144 FOSSIL TURTLES OF NORTH AMERICA.

The area of the scutes of the carapace is distinctly markt. The nuchal scute measures
58 mm. along the free border; 90 mm. along the posterior border. Fore and aft it is only 20 mm.
The first vertebral had a width of about 200 mm. Its length was100 mm. The second vertebral
was 100 mm. wide and 150 mm. long. Behind the first peripheral the costo-marginal sulcus
ran along the unossified space between the costals and the peripherals.

The plastron evidently had the form presented in O. gibbt. The piece of the bone consid-
ered by Cope as the epiplastron is the anterior outer end of the hyoplastron. At the axillary
notch the hyoplastron had a thickness of 11 mm. At the inguinal notch the hypoplastron was
14 mm. thick. As in the other species, there was an interchange of digitations between the
hypoplastron and the xiphiplastron.

Cope figured the right humerus. This bone lacks the head, both trochanters, and a little
of the distal end. The original length must have been close to 120 mm. The radial and the
ulnar crests made apparently something more than a right angle with each other. The shaft
is bent and flattened. The dorso-ventral diameter is 13 mm.; the horizontal diameter, 19 mm.
The width of the distal end is 38 mm. The femur is practically complete. The extreme
length is 132 mm. The bone resembles closely that of Chelydra. The planes of the tibial and
the fibular crests make a right angle with each other. The diameter of the shaft is 14 mm.;
that of the distal end, 36 mm.

In the American Museum of Natural History are portions of a large individual which is
referred to this species. There are present peripherals 7 to 11 inclusive of the left side, periph-
erals eight, ten, and eleven of the right side, and a considerable part of the hindermost
suprapygal. With these are other bones, some or all of which may belong to another individual,

possibly to another species. These con-
Width. sist of 2 complete costals, 3 neurals, the

Peripheral. Length. Height. | Thickness.;————— left hyoplastron lacking the inner end,
er oes face, Innerface. the left hypoplastron lacking a small

portion of the outer end, and a femur.

: 4 a * sd sh Besides these, there are parts of first,

9 106 103 17 a 7 second, and third suprapygals that can

= res a ‘ - not belong to the same individual as

a * as did the peripherals. All these bones

are included under the number 1132.

This is the specimen mentioned by Cope (Ext. Batr., Rept., etc., p. 142) as having been
found at Hornerstown, Monmouth County, New Jersey.

The peripherals (plate 26, fig. 3) indicate a large individual, with a carapace about 825 mm.
long. The dimensions of the peripherals are given in the table above, the measurements
being taken as in the case of the type specimen.

The pits for the rib-ends entering the hinder three peripherals are flattened, as in the No.
2351, and similarly they notch the upper face of the bones. None of the peripherals present
was suturally articulated with the costals, but the eleventh was sutured with the hindermost
suprapygal. The latter had a length of about 75 mm. and a width of 180 mm. It was there-
fore quite different from that of O. gibbi.

A fragment that must have belonged to another individual presents the first, second, anda
part of the third suprapygals, and a part of the eighth costal. The first suprapygal is about
40 mm. long and the width is the same. The second suprapygal has a length of 45 mm. and
a width, along the nearly straight hinder border, of about 130 mm. Of the third there is only
a small piece. The first suprapygal is crost by the sulcus between the fourth and the fifth
vertebral scutes.

One of the costals is probably the third of the right side. It has a length, over the curve, of
about 275 mm., not including the projecting rib-end. The breadth near the proximal end is
87 mm.; near the distal end, about 95 mm. The thickness at the sutural edges is 7mm. The
distal end had not been sutured with the peripherals. Articulated with this costal is a neural,
probably the third. Its length originally was about go mm.; its breadth anteriorly is 58 mm.
The posterior end is narrowed and rounded. The costal and this neural supported portions
of the third and fourth vertebral scutes. The fourth, at the hinder border of the costal, had a
width of about 140 mm.; the third was apparently slightly narrower.

-

THALASSEMYDIDA. 145

All the bones of the carapace here described are plentifully furnisht with pits. These vary
in size from I to 10 mm. in diameter. That some of them are not the result of disease or
parasites can hardly be afhrmed, but they must have been produced during the life of the
individual. i

The plastron may not have belonged to the individual that furnisht the peripherals; but
the size befits it. In form it agrees with that of O. gibbi. At the narrowest portion of the
bridge the hyoplastron and hypoplastron are each 67 mm. wide. As nearly as can be deter-
mined, the width of the plastron from side to side was about 480 mm. There was evidently
a fontanel inclosed by the two plastral bones mentioned and the peripherals. There was
another at the crossing of the median and the hyohypoplastral sutures. There was probably
still another at the midline just in front of the xiphiplastrals.

The thickness of the bones at the bridge is 20 mm.

The femur lacks the distal end. In form it resembles that of supposed O. sopitus, as
figured by Cope; but the size is greater. The diameter of the shaft is 18 mm.

No. 2216 of the American Museum of Natural History comes from some unknown locality
of the Cretaceous greensand of New Jersey, and forms a part of the Cope collection. It

Fics. 169-171.—Osteopygis borealis. Portion of carapace and lower jaw.

169. Front of carapace of specimen regarded by Cope as 0. sopitus. No.2351 A.M.N.H. c. p. 1, first
costal plate; nu. p, nuchal plate; nu.s, nuchal scute; per. 1, first left peripheral. XX #2

170. Lower jaw, seen from above. No. 2216 A.M.N.H. X43

171. Section along symphysis of same jaw. <4

is referred confidently to the present species, altho some differences may be observed.
It furnishes peripherals three, four, six to ten of the left side, five and eight of the right side;
the eleventh of one side or the other; the outer end of the left hypoplastron; and a large part
of the lower jaw. The latter is here described and figured.

Fig. 170 represents the jaw as seen from above. Fig. 171 is a section along the symphysis.
The length of the symphysis is 62 mm. The thickness at the hinder end of the symphysis
is18mm. This is gradually reduced forward. The symphysis extends backward about 9 mm.
behind the line joining the mental foramina. The width at the mental foramina is 92 mm. The
crushing surface is broad and flat, rising at the sides to the cutting-edges. For a distance of
about 32 mm. from the tip the cutting-edges are acute and are directed outward; they then
become obtuse, as is shown by section. There certainly was no upturned beak at the tip of the
jaw. Along the inside of the rami and behind the symphysis is a deep groove. The lateral
halves of the jaw are solidly co-ossified, but there remain distinct traces of the suture.

Osteopygis borealis differs from O. emarginatus, O. gibbt, and O. robustus in not having
the peripherals between the second and the eleventh joined by suture with the distal ends of
the costals. From O. erosus it differs in having bones of much thinner and lighter construction.
The anterior peripherals are, relatively to their length, of less height. In O. borealis the pits for

10

146 FOSSIL TURTLES OF NORTH AMERICA.

the ribs notch both the upper and the lower faces of the peripherals behind the seventh; in
O. erosus they notch only the upper borders.

O. platylomus differs in having the anterior peripherals higher in proportion to their
length and in having the upper border of the first and second thicker. In O. platylomus the
rib-pits of the sixth and seventh peripherals are decidedly flattened; in O. borealis they are
conical. O. chelydrinus differs in having the free border of the hinder peripherals angulated.

Osteopygis platylomus Cope.
Figs. 172-180.
Osteopygis platylomus, Core, Amer. Naturalist, 111, 1869, p. 89; Cook’s Geol. New Jersey, 1868 (1869),

p- 735; Ext. Batrach., Reptilia, Aves N. A., 1869, pp. 135, 137, and p. 1, figs. 38, 39; Vert. Cret.
Form. West, 1875, p. 258.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 441.

The type of Cope’s Osteopygis platylomus is a fragmentary specimen which belongs to the
Academy of Natural Science of Philadelphia. It was presented to that institution by Samuel
Ashhurst, having been discovered in the uppermost greensand bed of the Cretaceous, at Pem-
berton, Burlington County, New Jersey. It now consists of the anterior half of one neural,

ee a

Fics. 172 AND 173.—Osteopygis platylomus. Portions of type.
172. Part of a neural. #. 173. Pygal, suprapygal, and tenth and eleventh peripherals. 4.

most of the suprapygal, a portion of the nuchal, wholes or parts of all the peripherals of the
right side, except the fifth, wholes or parts of the first, third, sixth, eighth, ninth, tenth of
the left side, many fragments of costals and portions of the plastron. It appears that a few
parts have been lost since Cope described the specimen.

Cope estimated the length of the carapace at 2 feet 2 inches. ‘he writer regards the length
as having been close to 30 inches or about 750 mm.

The fragment of neural (fig. 172) is crost by a sulcus and is therefore probably either
the third or the fifth. It is deeply notcht in front for the preceding neural, and this notch gives
evidence that the neural was not the first one. The greatest width of the bone is 56 mm.

The bone described by Cope as the “posterior vertebral” is really the suprapygal. Only a
portion of the left end of the nuchal remains. It is articulated to a portion of the first left
peripheral. The free edge is obtuse and at the suture with the first peripheral the thickness is
17 mm. The bone extends backward from the free border a little more than 60 mm., to
articulate with the first costal. Here the thickness is only about 6 mm. The first marginal
scute occupies the outer end of the nuchal and the anterior end of the first peripheral. Along
the free border it is 58 mm. and it extends backward from the free border of the bone 33 mm.
Cope states that the nuchal scute was confluent with the first vertebral; but the writer regards

THALASSEMYDID&. 147

this as a mistake. After passing about 6 mm. the sulcus between the nuchal scute and the
first marginal, the sulcus between the nuchal and the vertebral scutes suddenly becomes very
shallow, but the writer believes that it continues on in its usual position.

A considerable part of the suprapygal (fig. 173) is missing. Cope’s statement that it is
only 2 inches and 4 lines wide is an error or meant to apply to some other bone. The bone in
question is at least 110 mm. wide. It occupies an area that in O. gzbbi is occupied by two bones,

——— = but a close examination shows a line running
Gength |! Height |e Width. from the upper angle of one eleventh peripheral

Peripheral. | 2 border. at sulcus. y | face. Innerface, t0 that of the opposite side, along which 2 bones

a= | is i — have co-ossified. The angulation of the upper
; p : 7 border of the eleventh peripheral shows that
5 75 49 15 y there were two suprapygals. Itis probable that
3 70 . 2 7 the sutural edge of the eleventh peripheral joined
es s as a the anterior suprapygal instead of the eighth
6 86 51 41 37 costal plate. The dimensions of the peripherals
g x Pe a 2 are shown in the table.
A 3 52 és 7 The sixth peripheral (figs. 174,175) presents
10 - Be Ee three faces, an upper concave, a lower convex,
a ae | 95 - and an inner irregular. The upper and lower

faces meet at the acute free border. In the
inner face is a large, somewhat flattened pit for the end of a rib. Its mouth occupies one-
half the length of the face. Along the lower border of the face are two or three shallow pits
for digitations of the hypoplastron.

As we proceed forward from the sixth peripheral the free border becomes less acute,
until, on the third, it is obtuse and the upper, now convex, face rounds into the lower. On the
second and first peripherals (figs. 176, 177) the lower face becomes the obtuse free border

of the bones. The inner faces of

‘ the fourth and the third contain pits

‘ for the corresponding rib-ends. The

= inner face of the second has a large

excavation which received the anterior

outer process of thehyoplastron. Fig.

176 represents the first, second, and

third peripherals of the right side.

The upper border of the first and

b the anterior half of that of the second

peripheral had a sutural articulation

with the first costal (fig. 176). The

thickness of these borders is 6 mm.

The hinder half of the upper border

of the second and the upper borders of all the other peripherals to the eleventh are smooth.

The upper border of the eleventh appears to have articulated with the suprapygals, as
already stated.

Passing backward from the sixth peripheral, the upper and lower borders of all the
peripherals broaden and become flatter. The inner face narrows, and finally on the eighth
(figs. 178, 179) and succeeding peripherals, curves into the lower face. Each of these periph-
erals, except the eleventh, has a pit for a rib-end. The hindermost peripherals are thin, the
ninth being 14 mm. thick, the eleventh about 10mm. The flattening of the rib-pits begins with
the sixth peripheral. The pygal is represented by fig. 173. Fig. 180 shows one lateral border.

There are present many fragments of costal bones, but no complete costal. The remains
seem to show that the carapace was rather flat. The thickness of the costals near the neurals
was about 6 mm.; near the distal ends, about 5 mm. The rib-heads were strongly developt.
Distally, each rib projected beyond the costal and entered the pit in a corresponding periph-
eral. The edges of the costal plates approacht closely the upper borders of the peripherals.

On the proximal ends of two costals the costo-vertebral sulci run along about 35 mm. from
the neural border. Another fragment shows that the vertebral scute was strongly angulated

d

Fic. 174.—Osteopygts platylomus. Sixth left peripheral

of type. X4.

a, from above; b, hinder end; c, anterior end.

148 FOSSIL TURTLES OF NORTH AMERICA.

laterally. The distal end of a costal bone is 70 mm. wide. The surface of the bones is usually
moderately smooth, but markt by irregular, rather straight, vascular grooves. The sulci are
usually quite distinct.

The nuchal scute is present, as stated. Its lateral extent is conjectural; the fore-and-aft
width is about 30 mm. The widths of the vertebral scutes can not be exactly determined;
but they all appear to correspond closely to those of O. gibbi Wieland. The first evidently

Fics. 175-180.—Osteopygis platylomus. Peripherals and sections.
Type. X#.

175. Sixth, seventh, and eighth right peripherals.

176. First, second, third, and fourth right peripherals.

177. Sections of first and second left peripherals. a, distal end of second; },

proximal end of second; c, near proximal end of first.

178. Hinder end of eighth: peripheral.

179. Front end of eighth peripheral.

180. Section along right articular border of the pygal.
extended laterally to about the middle of the first peripheral. The
eleventh reacht laterally the hinder border of the pit for the last rib.
The costo-marginal sulci run along on the upper borders of the first and second peripherals,
then disappear, to reappear on the upper borders of the eighth to the eleventh. From the
third to the eighth peripherals the sulci occupied doubtless the space between the costals and
the peripherals.

At present there remain of the plastron only a part of the left hyoplastron, most of the left
hypoplastron, and most of the right xiphiplastron. The plastron seems not to have differed
in any important way from that of O. borealts. Evidently there was a fontanel between the
hyoplastra in front and the hypoplastra behind. At the narrowest part of the bridge the hypo-
plastron is 58 mm. wide. The thickness at the inguinal notch is 16 mm. No sulci are to be
seen on these bones, except a faint one near the base of the xiphiplastron. To the present
writer it seems evident that the bones on the right of Cope’s figure of the plastron of this species

THALASSEMYDID&. 149

have been taken from the plastron of one of the specimens described by him as O. emar ginatus.
Remarks on this specimen are made under the last-named species. In Cope’s figure of the
plastron the hyoplastron on the left side of the drawing is placed too horizontally. T tie anterior
outer angle ought to be directed strongly forward. This species resembles O. borealis. For
differences see under the latter species.

Osteopygis sopitus Leidy.
Figs. 181-184.

Chelone sopita, Leipy, Smithson. Contrib. Knowl., xtv, 1865, pp. 104, 119.—Maack, Paleontographica,
xvi, 1869, pp. 238, 283.
Osteopygis sopitus, Hay, Pibien: and Cat. Foss. Vert. N. A., 1902, p. 441 (in part).

The type specimen of the present species has not hitherto been figured. It belongs to the
New Jersey State collection and is at Rutgers College, New Brunswick, New Jersey, where
the writer has examined it. This type consisted of 4 peripherals, but Leidy was uncertain
whether or not they belonged to one individual. These bones had been obtained in the
Cretaceous greensand at Tinton Falls, Monmouth County, New Jersey, probably in the upper
bed. Other specimens, which were mentioned by Leidy in his description of this species and
figured, were afterwards referred by Cope to Lytoloma angusta, and probably correctly so.

182a.

H
?

3

)

t

4

3

z

5

4

;
=

i
|
'
1

184.

Fics. 181-184.—Osteopygts sopitus. Peripheral of type.

181. Seventh? peripheral, with section.

182. Hinder peripheral, with section (182a). The interrupted line of the
section indicates the depth of the pit.

183. Hinder peripheral.

9.

184. Section of a peripheral.

Other specimens were referred by Cope to Leidy’s species. One of these had been
secured at Harrisonville, Salem County, New Jersey, in a sort of limestone. This specimen 1s
now in the American Museum of Natural History and has the number 2361. Almost certainly
it is not a species of Oste eopygis, and it has in the present work been referred provisionally
to Rhetechelys platyops (Cope).

The four peripherals of the type belonged behind the bridges. Figures taken from three
of these are here presented. Fig. 181 represents in outline one which is regarded as being the
right seventh. It is 115 mm. long, 59 mm. wide near the anterior end, 20 mm. thick at this end,
and 12 mm. at the posterior end. There are 3 faces—an upper, a lower, and an inner, or
visceral. The pit for the rib is nearer what is regarded as the hinder end and is somewhat
flattened in section. Above the figure is a section taken at the anterior end of the bone. Another
peripheral (fig. 182) is about 87 mm. long, 82 mm. wide, 18 mm. thick at one end, 14 mm. at
the other. In the visceral face is a pit for the end of a rib. Each diameter of the pit at its
opening is g mm. The upper face is quite concave from the acute free border to the costal
border. Near the figure is a section (1822) taken at the thicker end of this peripheral, which
represents the diameter and depth of the rib-pit. Another peripheral, probably a ninth or
tenth, has the costal border broken away. The rib-pit is flattened. Figure 183 is a section of
this bone. Its greatest thickness is 24 mm. Fig. 184 is a section taken alshe the transverse
sulcus of a fragment representing about one- -half of a peripheral. The upper and lower faces

150 FOSSIL TURTLES OF NORTH AMERICA.

measure 48 mm. each, while the concave visceral face is 22 mm. wide. The mouth of the pit
is circular.

Cope referred to this species a specimen which now has the number 2351 of the American
Museum and which is regarded here as belonging to the species since described by Wieland
as Propleura borealis, here as Osteopygis borealis. If all of the peripherals described by Leidy
belong to the same species this can not be the same as Cope’s species; for the peripheral here
represented by fig. 181 is too long and narrow. Furthermore, the peripheral with the missing
costal border is too thick. In ‘he doubt, therefore, it seems best to regard Leidy’s materials
and Cope’s as belonging to distinct species, making the elongated peripheral of Leidy’s spec-
imens the type of his species and leaving it to future discoveries to determine whether or
not any of Leidy’s materials are co-specific with Cope’s specimen.

Genus CATAPLEURA Cope.

A genus not well known. Nuchal bone little broader than the anterior peripherals.
Nuchal and first and second peripherals suturally joined to the first costal bone. The other
peripherals to the eleventh probably not suturally connected with the disk of the carapace. No
pit in the second peripheral for the hyoplastron. A pit in the eleventh peripheral for the rib of
eight costal. Plastron probably resembling that of Osteopygis, but not extending so far along
the peripherals.

Type: Catapleura repanda Cope.

This genus differs from Lytoloma in having the two anterior peripherals solidly joined to
the first costal. It differs from Osteopygrs in the much narrower nuchal bone and in having
no pit in the second peripheral for the process of the hyoplastron. From both Lytoloma and
Osteopygis it differs in the much thicker posterior peripherals.

The genus was establisht by Cope in 1870 (Ext. Batrach., Reptilia, Aves N. A., p.
143). On page 235 of the work cited Cope exprest himself in doubt whether there were
nine or ten costal plates present. In 1884 (Vert. Tert. Form. West., p. 112) doubt is exprest
whether there were g costals. There can now be no doubt that this genus, like Osteopygrs
and the great majority of turtles, had only 8 pairs of costals.

Catapleura repanda Cope.
Figs. 185-188.

Osteopygis repandus, Cops, Proc. Acad. Nat. Sci. Phila. 1868, p. 147 (nom. nud.).—Hay, Bibliog. and
Cat. Foss., Vert. N. A., 1902, p. 441.

Propleura repanda, Corr, Cook’s Geol. New Jersey, 1868 (1869), p. 735 (nom. nud.).

Catapleura repanda, Cope, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 143, plate vii, fig. 2; Vert. Cret.
Form. West, 1875, p. 259-

The present species is based on very meager materials and none additional has been
discovered since the first description of the species. The type is now in the American Museum
of Natural History and consists of a part of the nuchal, the succeeding three peripherals and a
part of the fourth of the right side, the first of the left side, and four other peripherals, one
nearly complete costal and parts of others, and a portion of a femur. The catalog number is
2353. These bones were obtained from the upper bed of Cretaceous greensand at Barnesboro,
Gloucester County, New Jersey.

The nuchal bone (fig. 185) is remarkable for its narrowness fore and aft, being only 47 mm.
The widths of the first and second peripherals are respectively 43 mm. and 44 mm. The
free border of the nuchal is somewhat obtuse and the thickness soon becomes IO mm., at
the end of the bone. The posterior border articulated suturally with the first costal. The
posterior sutural edge is oblique to the surfaces of the bone and the nuchal slightly overlapt the
first costal. The thickness of this border is 8.5 mm. The posterior border of the nuchal was
much wider from side to side than the anterior border. On the end of the nuchal, nearer the
anterior border, there is a notch which receives a process of the first peripheral (fig. 185).
The latter measures 50 mm. along the anterior border, 17 mm. along the posterior. Its free
border is more obtuse than that of the nuchal. The second peripheral (fig. 185) extends 53
mm. along the free border. It is 13 mm. thick near the free border, 7 mm. thick at the hinder

°

THALASSEMYDID&. rt 51
border. The hinder border both of this bone and of the first peripheral is oblique and overlapt
the first costal, as did the nuchal. The hinder half of the upper border of the second peripheral
is broken away and we can not tell how much of it was sutured to the costal. There is no pit
in the second for the anterior outer angle of the hyoplastron, and it is not probable that the
latter bone extended so far forward.

The third peripheral is 60 mm. long on the thickened and obtuse free border. On the inner
face is a deep pit, directed backward, for the rib-end of the first costal. Below this, in the pro-
jecting edge is a notch, possibly for a digitation of the hyoplastron. Of the fourth peripheral
there is present only a portion. Its lower face is 26 mm. wide, and this makes an angle of ninety
degrees with the upper face, the angle where they meet being rounded off. The upper borders
of the third and the fourth peripherals are broken away. Cope figured what he regarded as the
sixth peripheral, and there is a fragment of a peripheral, which he has markt as the sixth;
but it is impossible now to to say that the bone present is the one figured. The bone has one
face, apparently the upper, 44 mm. wide. Another face, somewhat concave, is separated from

Mena monic,

,

oe

Fics. 185-188.—Catapleura repanda. Portions of shell of type. x 3.

185. Nuchal, and first and second peripherals. nw. p, nuchal bone; per. 1, per.
2, first and second peripherals.

186. Portions of the eighth and ninth peripherals. Free border toward the right.

187. Section across ninth peripheral. 188. Third or fifth costal.

this by a subacute free border. Cope has figured what he regarded as the eighth and part of the
ninth peripherals. In reality, there is only a small portion of the eighth and about two-thirds
of the ninth (fig. 186). Evidently these belong to the right side, since the intermarginal sulcus
crosses in front of the rib-pit. The latter is in the hinder half of each bone. The upper border
of the upper face of both these bones is missing, but that part of the face of the ninth which
remains is 47 mm. wide and is slightly concave. The lower face, also slightly concave, is 46
mm. wide. The inner face has been about 25 mm. wide. Fig. 187 is a section of the ninth
along the intermarginal sulcus. The outer free border of the bone is acute and has projected
slightly at the end of the intermarginal sulcus, making the free border somewhat repand.

On the free border and between the two bones here described is a long notch which, during
the life of the animal, inclosed a distinct ossicle. This reminds us of similarly disposed ossicles
described by Wieland as occurring in his Lytoloma angusta (L. wieland:), and which he was
inclined to regard as a part of a disappearing primitive osteo-dermal armor of turtles. From the
manner of growth of the horny scutes one would rather expect to find such bones, if a part of
the ancient armor, at the ends of the intermarginal sulci.

152 FOSSIL TURTLES OF NORTH AMERICA.

There is present a part of a peripheral which Cope has labeled as the tenth. The upper
borders of both the upper and lower faces are missing, but these faces are yet 58 mm. wide. At
its upper, or proximal, border, the bone is 18 mm. thick. The hinder half of the bone is lost
but enough apparently remains to show a part of the rib-pit, had it been present in the bone.
Since in C. ponderosa the eighth costal sent its rib-end into the eleventh peripheral, it is prob-
able that there was no pit in the tenth. If the bones regarded by Cope as the eighth, ninth
and tenth are really such they differ greatly from the corresponding ‘bones of Osteopygis,
being, relatively to their length and height, much thicker.

The costals are extremely interesting, but they are not well understood. There is one which
is nearly complete, quite certainly either the third or the fifth. It has a width of about 50 mm.
(fg. 188). The curvature shows that the carapace was considerably archt from side to side.
Cope regarded this costal as that of the right side, but there are reasons for believing that it
belongs to the left. One sutural border is thicker and has the suture oblique to the surface of
the bone in such a way that it must have been overlapt by the contiguous bone. We have
seen that the hinder border of the nuchal and the first two peripherals overlapt the first costal.
It seems improbable that from having the anterior border overlapt in the first costal a change
would be made, about the middle of the shell, to having the posterior border overlapt. The
present costal can not, however, be the first, for the proximal end of its fellow bone is present
and does not accurately fit to the nuchal and first peripheral. It can not be the second, for it is
not traverst by a sulcus separating two costal scutes. It seems probable that it is the left
third. The posterior sutural edge is at right angles with the surface and hence it did not overlap
the succeeding bone. The thickness, too, is reduced to 5mm. The upper surface of the costals
is smooth. On the one described there are parts of 2 vertebral scutes, probably the second and
the third. On the supposed posterior border of the bone the costo-vertebral sulcus is 25 mm.
from the neural border. The surfaces of the peripherals are markt by zigzag vascular grooves.

On the under side of the costal is seen a large rib-head and stout ridge proceeding from it to
the distal end. At the proximal end this ridge lies a little nearer to the supposed anterior border
and on its way to the distal end it gets closer to this border, being only 3 mm. away from it
finally. In his description Cope states this ridge lies near the posterior border. In front, that
is on the side next the beveled border of the costal, there is a rough groove, as if a rudimentary
first rib had been applied against the ridge. The meaning of the groove is unknown. It is
found in three of the costals represented.

Not enough of the femur is present to furnish definite information regarding its structure.
The head is missing. The shaft has a diameter of 11 mm.

What is determinable regarding the vertebral scutes has been stated above. On the
nuchal and the anterior peripherals the marginal scutes rise only a moderate distance above the
free border of the shell. On the median and hinder peripherals the costo-marginal sulci appear
to have followed the unossified space between the costal and peripheral bones. The nuchal
bone does not reach the midline, and hence we can not determine exactly what was its width
nor that of the nuchal and first vertebral scutes. ‘The boundary between the nuchal scute and
the first marginal is believed to be where shown in fig. 185. The first vertebral scute lacks a
considerable space of reaching the outer ends of the nuchal bone, and was, hence, evidently
narrow. ‘The first marginal rises about 28 mm. above the border of the carapace; the second
about 18 mm.

Catapleura ponderosa Cope.
Figs. 189, 190.

Catapleura ponderosa, Core, Proc. Amer. Philos. Soc., x11, 1871, p. 46; Vert. Cret. Form. West, 1875, p.259-
Osteopygis ponderosa, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 441.

The present species is based on materials even less satisfactory than is C. repanda. They
consist of portions of the eleventh peripheral and the pygal, portions of about 6 costals, a
part of a supposed hypoplastron, a scapular arch, a considerable part of a humerus, a part of
a femur and a part of a lower jaw.

The type is now in the American Museum of Natural History and has the number 1475.
These bones were obtained by Cope from the uppermost bed of Cretaceous greensand, at
Hornerstown, New Jersey.

THALASSEMYDID&. 15 3

The pygal bone (figs. 189, 190) had a width of about 80 mm. along the free border. Some
of the upper border has crumbled away, but the height of the bone was close to 65 mm. Its
thickness a short distance below the upper border is 1g mm. The upper surface is concave fore
and aft; convex from side to side. On the lower side the directions of these forms of surface
are reverst. The free border is acute. The upper border was probably suturally articulated
with the suprapygal. On neither the upper nor the lower side of this bone is there any trace
of a sulcus. ;

Of the eleventh peripheral Cope had no more than is now present, the hinder half, articu-
lated with the pygal. It is concave from the free edge to the upper border on the upper surface,
rather strongly convex on the lower surface. In the upper border there remains a portion of
the deep pit for the rib-head of the eighth costal. The greatest thickness of the bone is 19mm.
While a considerable part of the free border is broken away, that remaining seems to indicate
that this border was emarginate, as was stated by Cope. No sulcus appears on this bone.

Two of the costals represented are evidently those of the same pair. Cope thought they
were those of the second pair. The proximal end was 82 mm. wide. One of the sutural
borders is 11 mm. thick, and the suture is oblique to the surfaces of the bone. It was evidently
overlapt by the bone to which it was articulated. The opposite border is only 5 mm. thick.
Under C. repanda reasons have been given for regarding the border bearing the oblique suture
as the anterior one; and the costals of the two species are so similar that the same rule applies
here. As in C. repanda, the rib-head is strongly developt, as well as the rib in its course along

Fics. 189 AND 190.—Catapleura ponderosa. Portions of type. 3.
189. Pygal and eleventh peripheral. 190. Section along midline of pygal.

the under side of the costal. As in C. repanda, this rib gets nearer and nearer the thickened
side of the costal on its way toward the distal end. There is also a rough groove near the prox-
imal end of the front of the ridge; but it is not so conspicuous as in the other species. More-
over, it is seen only on the two costals supposed to belong to the second pair.

On none of the costals or peripherals are there observed any remains of sulci, to mark the
limits of the horny scutes. The costals are markt by very distinct branching vascular grooves.

There is present a fragment of a plastral bone, which was interpreted by Cope as the
hinder part of the left hypoplastron.- The writer finds it impossible to identify the bone satis-
factorily. One border is obtuse and 14 mm. thick. The opposite border is thin and irregular.

Only the proximal half of the right humerus is present. The long axis of the head
measures 35 mm., the shorter 24 mm. The radial process is missing, but it continued to the
head of the bone. The ulnar process lacks much of rising to the level of the head, and the ridge
descending from it runs well down on the shaft. The planes of the radial and ulnar processes
make with each other an angle of more than go°. The shaft of the bone is comprest, having
a diameter of 15 mm. in the perpendicular plane; of 11 mm. in the horizontal. It is therefore
comprest in a manner directly opposite to that of the Chelonide.

The femur is that of the right side and lacks the distal end. The portion remaining is 93
mm. long; and the whole bone must have been about 120 mm. long. As in the more primitive
turtles, the head and the processes resemble those of the humerus. The head has diameters
respectively of 23 mm. and 30 mm.

154 FOSSIL TURTLES OF NORTH AMERICA.

The fibular process rises only to the lower level of the head. The tibial process is broken
off. The planes of the two made with each other an angle of more than go°, and there is a
broad fossa between them, open below. The ridge from the tibial process runs far down on
the shaft. The least diameter of the latter is 12 mm.

The present species appears to differ from C. repanda in having no traces of sulci between
the epidermal scutes, in having the ridge formed from the rib on the under side of the costal
more strongly developt and more angular, and apparently in having the hinder peripherals
more recurved toward their free margins. To judge from the types, C. ponderosa was con-
siderably the larger species.

In his description of this species Cope mentions a portion of the mandible which had
accompanied the other bones. ‘This bone is now at hand. It consists of the nght dentary. The
tip of the dentary and the hinder portion of the cutting-border are missing. The break
between two dentaries appears to have followed the midline. The length of the symphysis
was close to 36 mm. and its hinder end extended back to a line joining the mental foramina.
The latter are small. From,the symphysis the upper surface of the dentary descends slightly
outward, then rises considerably to the cutting-border. ‘The lower side of the dentary is
flat for a considerable distance on each side of the midline, then rises in a strong curve to
the cutting-edge. The thickness at the hinder end of the symphysis is 11 mm. The jaw is
strongly grooved behind. This dentary resembles that described under O. chelydrinus; but,
having the same width, the latter is thicker and heavier.

Genus LYTOLOMA Cope.

Lower jaw with broad, flat crushing-surface and long symphysis; the tip not beaked.

Carapace resembling that of Caretta caretta but less pointed behind. None of the anterior
peripherals suturally articulated with the costal plates, rib-pits of most of the peripherals in
the hinder half of these bones. The eleventh peripheral with pit for mb of eighth costal.
Plastron not well known, but believed to have a narrower connection with the carapace than
in Osteopygis. Limbs not well known, the humerus and femur supposed to have about equal
development, with tendencies toward the structure of the same parts in Cheloniide.

The type of this genus is Lytoloma angusta Cope. This is represented by some peripherals
and a lower jaw, all supposed to belong to the same individual. Dr. Wieland has described and
figured a considerable portion of a carapace which he referred provisionally to L. angusta, but
which is here placed with doubts under L. wieland1.

A considerable number of species from the Eocene of England and Belgium have been
arranged under this genus, after having been assigned variously to Chelone, Pudlasies Puppi-
gerus, Clossee helys, P achyr hynchus, R iisles woenelye. and Erquelinne sta. For the accuses of
the subject the reader is referred to the original papers. These are cited by Mr. Richard
Lydekker in his Catalogue of Fossil Reptilia, part 111, page 51.

It is evident, however, that few, if any, of these species really belong to Lytoloma. Owen's
Chelone crassicostata, the palatal view of which is figured by Lydekker (Exoc. Zool. Soc. Lond.,
1889, pl. vi), under the name of Lytoloma crassicostatum, has the choane pushed backward to
the hinder third of the skull, and the palatine bones meet for a considerable distance behind
the vomer. In the article accompanying the figure just cited Mr. Lydekker informs us that
Dollo’s species originally described under the name of Pachyrhynchus gosseleti is identical
with Owen’s Chelone crassicostata. For the genus represented by this species it appears that
Dollo’s name Erquelinnesia will have to be employed.

The skull of Owen’s Chelone planimentum resembles in general that of his C. crassicostata,
but its palate appears not to have been described. Nevertheless, the carapace presents several
peculiarities. ‘The neurals have the antero- lateral and the postero- lateral sides equal, the ribs
present themselves on the under side of the costals as prominent, narrow, and angular ridges,
and the peripherals are much more reduced than in C. crassicostata. It seems probable that
we have here a distinct genus, and for this Seeley’s name Glossochelys will be available.

Dr. W. B. Clark has publisht ( Johns Hopkins Univ. Circ. xv, 1895, No. 4; Bull. U.S. Geol.
Surv., No. 141, 1896, p. 59) a mention of some fragments of a large carapace found in the
Aquia formation in Maryland, which he supposed might belong to Cope’s Euclastes. Case

THALASSEMYDID&. S55

(Geol. Surv. Maryland, Eocene, 1901, p. 97. pl. x, hg. 7) has repeated Dr. Clark’s words and

figured one fragment. The materials are generically indeterminable.

Lytoloma angusta Cope.
Plate 28, figs. 5, 6; text-figs. 191, 192.

Chelone sopita (in part), Leipy, Smithson. Contrib. to Knowledge, x1v, 1865, p. 105, plate xix, fig.

Lytoloma angusta, Cope, heten Naturalist, m1, 1869, p. 105 (nom. nud); Ext. Batrach., Reptilia, reer
N. A., 1869, p. 145, plate xi, figs. 1, 1b; Vert. Cret, Form. West, 1875, p. 257 —Hay, Bibliog. and
Cat bse Vert. N. A., 1902, p. 442.

Cope’s first mention of this species was in the American Naturalist, as quoted above, but
this mention was made only incidentally and what was said is not sufficient to distinguish
either the species or the genus from various other turtles. When he came to describe and figure
the species Cope stated that his materials consisted of three peripheral bones, a fragment of a
costal,and a lower jaw. He says that the costals and marginals were found at the same time and
place as the jaw and probably belong to it. It seems that he regarded the peripherals as the
type of the species, and since he figures only one of these, this especially must be taken as the
type. That he so regarded the peripherals is evident from the fact that
from peripherals alone of this species and L. jeanes: he drew all his generic
characters. Further proof is afforded by the specimen of the jaw itself,
which bears, in Cope’ s writing, the label “?Lytoloma angusta Cope, Bir-
mingham, N. J.” Incase he fod lookt upon the jaw as the type he could
hardly have questioned its belonging to the species. It is wholly prob-
able that at least the figured peripheral and the costal belong with the
jaw; and until it has been shown that they do not, all may pass as types.
These specimens were obtained in the upper greensand beds of the Creta-
ceous, at Birmingham, near Pemberton, New Jersey. Inasmuch as the jaw
is labeled by Cope as coming from Birmingham, itis probable that the
specimens were obtained from some marl-pit between the two towns.
They are now in the American Museum of Natural History and bear the
number 1133.

The figured peripheral (plate 28, fig. 6) is said by Cope to belong to
the left side, but on the bone itself he has written “5 R,” from which
it appears that he regarded it as the fifth of the right side, and such it
——~s.---' seems to be. It has a length, along the acute free margin, of 67mm. A
section of the bone is triangular, and therefore it shows three faces (fg.

ilmenite. 191). The visceral face is 22 mm. wide, somewhat concave, and contains
Peripherals of in the hinder half of the bone a deep conical pit for the rib-end of the
type. x3. third costal. “The upper face is slightly concave at right angles with the
free border, 22 mm. wide at the anterior end, 29 mm. at the posterior.
1g. Section through filth The inferior face is slightly convex and 32 mm. wide at each end.
peripheral. Pit R ere ee! re os
shown by inter- Another peripheral (fig. 192) is markt by Cope “?2 R.” It has a
tupted line. length of 70 mm., a thickness at the visceral face of 16 mm. at one end
eee ie eae ae and 13 mm. at the other. The upper and lower faces are somewhat con-
Bee Pept vex. In the free border there is a broad emargination. At the bottom
of this emargination the bone is 28 mm. wide. At one sutural end the width is 34 mm. There
is no rib-pit in the visceral face. The peripheral, supposed by Cope to be the fourth, is not
now with the other bones.

The fragment of costal has a width of 47 mm. near the sutural border for the neural. At
the middle of the width the thickness is 10 mm.; at the sutural border it is about 4 mm. As
stated by Cope, there is present the sulcus bounding one of the vertebral scutes. From a
comparison with the figure publisht by Wieland, and ‘here reproduced (fig. 196), this costal is
believed to be the endl. of the right side. The outer angle of the vertebral scute is placed neat
the hinder sutural border of the bones, at a distance of 50 mm. from the neural.

The lower jaw (plate 28, fig. 5) is of the greatest interest. It is considerably eroded and
does not lend itself well to illustration. It is remarkable for the great length of the symphysis,

Fics. 191 AND 192.—

156 FOSSIL TURTLES OF NORTH AMERICA.

52 mm., and for the flatness of the triturating surfaces. An unimportant part of the tip of the
jaw is broken off. There was certainly no upturned beak, such as there must have been in
Rhetechelys platyops (Cope); nor was there a cutting-edge that rose much above the triturating
surface. The lower surface of the jaw is likewise very flat, rising abruptly toward the bee
borders. The thickness at the hinder end of the symphysis is 18 mm.; at a distance of 25 mm.
behind the tip the thickness is 16 mm. The coronoid process rises 40 mm. above the bottom
of the ramus. The rami are thoroly co-ossified. There are no other bones of the jaw
present except the right coronoid, which is crowded to the inside of the coronoid process of the
dentary.

At the tip of the jaw the borders of the dentaries diverge at an angle slightly greater than a
right angle. At the fronts of the fossa for the masseter muscles the width is gt mm.; at the
hinder end of the dentaries it is 110 mm. ‘The fossa just mentioned are large and deep. That
part of each on the dentary is 40 mm. long and 26 mm. high. At the front of each fossa is
a mental foramen. A line passing from one of these to the cher falls 12 mm. in front of the
hinder end of the symphysis.

The fragmentary skull materials described by Wieland provisionally under the name of
L. angusta (Amer. Jour. Sci., xvuI, 1904, p. 184, 185, figs. 1, 2) are here made the types of a
new species. The carapace which that author has also referred to L. angusta (op. cit., p.
187, pls. vi-vin) doubtfully belongs to it. In case the peripheral regarded by Cope as the
second really belongs with the type, the carapace described by Wieland certainly does not
belong to the species to which he has assigned it, for that peripheral in. the type has the border
emarginate. Furthermore, the fifth peripheral of L. angusta does not resemble closely any
of those of the carapace described by Wieland. It resembles most nearly the fifth of Wie-
land’s specimen, but differs in relative length and width; apparently also in the position of
the pit for the rib. Only future discoveries can decide this point.

The bones figured by Leidy (as cited in the synonymy) under the name of Chelone sopita
have been referred by Cope to Lytoloma angusta. They appear not to agree with any species
of Osteopygis in that they are much longer than wide, have the sulci crossing the middle of
the length and have the pits well toward the rear end of the bone.

Lytoloma jeanesi Cope.
Figs. 193-195.
Propleura jeanesit, Cope, Cook’s Geol. of New Jersey, 1868 (1869), p. 735 (nom. nud.).

Lytoloma jeanesi1, Corr, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 145; Vert. Cret. Form. West,
1875, p. 257.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452.

Of this species Cope studied what he regarded as portions of 2 individuals. Of the first,
discovered in the upper bed of Cretaceous greensand, near Barnesboro, Gloucester County,
New Jersey, there were secured only the nuchal bone and the first peripheral. Cope appears
to have lookt upon this lot as the type of the species. Where these bones are now is not
known. The second individual was obtained in the same bed of greensand, at Hornersville,
New Jersey. This specimen, or most of it, is now in the American Museum, where it has the
number 1473.

The nuchal bone which belonged to the first-named individual was described by Cope as
resembling an ordinary peripheral, differing entirely from the nuchal of Chelydra and Chelone.
The anterior border appears to have been obtuse. Its length, from side to side, is not given;
the width is stated to have been 16.5 lines (about 34 mm.). The nuchal scute which it bore is
said to have been about 18 mm. wide. The bone is described as having joined the first
peripheral by a coarse gomphosis, the process coming from the first peripheral. There was
also a sutural border for union with the first neural; but we are not told whether or not the
nuchal articulated with the first costals.

The first peripheral is described as having a free inner border, a condition showing that it
did not articulate with the first costal. Its suture with the nuchal was straight; that with the
second peripheral had the entering angle seen in Osteopygis sopitus, etc. The width of the first
peripheral is given as 15.5 lines, AnGut 32 mm. This width was three-fifths of the length,
therefore about 53 mm.

THALASSEMYDID. 1S 7

Of the second individual examined by Cope the first peripheral is at hand (fig. 193). It
has an obtuse free outer and an acute free inner margin. The thickness near the proximal
end and the outer border is 12 mm. At the hinder end (fig. 194) the thickness is somewhat
less. On the distal half of the bone and near the free margin, or rather, forming the free
margin, is a low sharp ridge, at which the upper and the lower surfaces meet. The suture with
the nuchal is oblique, running from the inner border forward and toward the midline, then
forward and outward, then again forward and toward the midline. The end of the bone was
somewhat overlapt by the nuchal. The length along the free outer border is about 65 mm.;
along the free inner border, about 40 mm.; from one extremity to the other, 80 mm. The
greatest width is 35 mm.; that near the hinder end is 27 mm.

The peripheral regarded by Cope as the sixth (fig. 195) has a length of about 100 mm.
A part of the free border is broken away. The bone is triangular in section, presenting thus
three faces. The inner or visceral face is quite concave the whole length and has in the
hinder half a deep conical pit for the end of a rib. The bone is about 30 mm. wide. The lower
face is slightly concave and is 30 mm. wide. The upper face has a width of from 35 mm. to
38 mm. and it is nearly plane. According to the present interpretation, the bone belongs to
the right side. All of the free borders are acute, especially the upper inner, and in none of
them is there any emargination.

Fics. 193-195.—Lytoloma jeanest. Peripherals. 3. No. 1473 A. M.N. H.
193. Right first peripheral.
194. Section near distal end of first peripheral.
195. Section of sixth? peripheral. Pit shown by interrupted line.

Accompanying the bones above described is a fragment of a costal which agrees in its
dimensions with the one mentioned by Cope. Its width is 90 mm., while the thickness
thru the middle of the width is 11 mm. Cope states that the costals showed no sculpture.
However, the present costal has its surface broken by numerous pits of varying form and size,
resembling thus closely the costals of Osteopygis erosus. It is probable that the bone belongs
elsewhere.

The peripheral described above as probably the sixth differs so much from the fifth of
L. angusta that a distinct species is clearly indicated. The ratios of width to length in the
two bones are very different. The width of the peripheral of L. angusta is contained in the
length about two and a third times; while in that of L. jeanes: the width is contained in the
length three and a third times. The results are equally decisive in case both peripherals
should happen to be fifths or sixths. It is wholly probable that neither of them can belong
farther backward in the series.

The various measurements of this bone show that the carapace described by Wieland can
not belong to L. jeanest.

Lytoloma wielandi sp. nov.
Plate 28, figs. 7, 8; plate 29, fig. 1; text-figs. 196, 197.
Lytoloma angusta?, WirLanv, Amer. Jour. Sci. (4), XVI, 1904, p. 183, plates vi-viii, text-figs. 1-3;

Ibid., xx, 1905, p. 333, fig. 5-

Dr. George R. Wieland has, with exprest doubts, referred some lower jaws, the front of a
skull, and a carapace of a Lytoloma to L. angusta. His specimens are in the Yale University
collection. The skull bones were secured by Professor O. C. Marsh from the upper Cretaceous
greensand bed at Hornerstown, New Jersey. The carapace came from Barnesboro. It seems
evident that these remains do not belong to the species to which they have been assigned,
and they are here made the types of a new species, named in honor of Dr. Wieland.

158 FOSSIL TURTLES OF NORTH AMERICA.

In case it shall hereafter be discovered that more than a single species is represented by
these bones, the lower jaw figured by Wieland shall be regarded as the type of L. wreland1.

That this lower jaw is not identical specifically with that regarded as belonging to the
type of L. angusta appears from the following considerations:

(1) The angle subtended by the cutting- Gomer of the jaw of L. angusta forms at least a
right angle; in L. wieland1 this angle is 80 degrees.

(2) ia L. angusta the lateral Gitlines of the jaw continue outward and backward in nearly
straight lines to the mental foramina; in L. wieland the borders are deflected more nearly
backward at a considerable distance in front of these foramina.

(3) In L. angusta a line drawn from one foramen to the other falls 12 mm. in front of the
hinder end of the symphysis; in L. wreland: it falls at the hinder end of the symphysis.

(4) In L. angusta the descent from the summit of the coronoid is much more abrupt than in
the other species considered. In the former species the height of the coronoid process is 77
per cent. of the length of the symphysis; in the new species, only 60 per cent.

(5) The tip of the jaw of L. wrelandi appears to have been more upturned, more acute,
and in every way more beak-like than in L. angusta.

Differences so great as indicated above in two jaws whose symphyses are respectively 52
mm. and 42 mm. can hardly be attributed to differences in age or sex. At least, so great
differences do not appear in a number of jaws of the log eperhead turtle, to which the jaws of
Lytoloma have great resemblances. In a huge skull of the loggerhead, the length of which
from snout to occipital condyle is 230 mm., the line joining the mental foramina falls at the
hinder end of the symphysis, while it falls only 12 mm. behind the symphysis in a young
specimen whose skull is only 130 mm. long. As to the lateral outlines of jaws, the elevation of
the coronoids, and the form of the tip, there is not much difference among specimens of middle
and large sizes. The angle subtended by the outlines of the anterior portions of the lower
jaws of Caretta may, however, vary as much as in the case of L. angusta and L. wieland1.

The width of the j jaw forming the type of L. wielandi, taken at the mental foramina, is
66 mm.; taken at the hinder ends of the dentaries, 75mm. The length of the symphysis is
42 mm. The greatest thickness at the symphysis is rt mm.

The front of the skull figured by Wieland agrees in size and in the angle made by the
borders of the upper jaws with the lower jaw just described. A comparison made with the
jaw of the loggerhead indicates that the skull of which it formed a part had a length of about
156 mm. Seen from above or below, it resembles considerably the same part in the log-
gerhead. Seen from the side, the tip of the snout is much more deprest than in the loggerhead,
a condition due probably to the little-developt cutting-edge of Lytoloma. Plate 28, fig. 7, rep-
resents Wieland’s type skull seen from above; plate 28, fig. 8, as seen from below; and plate
29, fig. 1, as seen from behind. These figures are reproduced from drawings made for Dr.
Baur in 1888.

The orbit was large. The prefrontals joined along the midline for a distance of at least
12 mm. and to a line crossing the skull considerably behind the fronts of the orbits. In Rhe-
techelys platyops (Cope) the prefrontals were parted by the frontals to a line considerably in
front of the orbits.

The external nasal opening has its transverse and its longitudinal dimensions each 20 mm.
The snout as seen from above is not acuminate, as it was in Rhetechelys platyops.

The vomer appears, as in Rhetechelys platyops, to have wholly separated the horizontal
plates of the palatines. It has a length of 33 mm. and a width of 20 mm. The width of the
perpendicular plate of the vomer, between the narial passages, is 11 mm. The choane are
thrown well backward, but it is doubtful whether they were pushed backward as far as they
were in R. platyops, to a line joining the hinder borders of the orbits.

There is no certainty that the carapace described by Dr. Wieland belongs to the present
species, and it is so referred only because it seems to belong neither to L. angusta nor L.
yeanest.

This carapace (fig. 196) was received by Prof. O. C. Marsh, May 1, 1869, it having been
sent to him from the upper greensand bed of the Cretaceous, near Barnesboro, New Jersey.

The estimated length of the carapace is 580 mm.; the greatest breadth, 530 mm. In
general, it resembles the carapace of the loggerhead, but it is far less pointed behind, a con-

THALASSEMYDID. 159

dition showing that the turtles of this genus had not yet become seafarers. At Dr. Wieland’s
disposal, belonging to this specimen, were wholes or parts of the third, fourth, fifth, and sixth
neurals, wholes or parts of two suprapygals, wholes or parts of all the costals of the right side
and of most of those of the left side, wholes or parts of all the peripherals of the left side behind
the third and of most of those of the right side behind the third, and a portion of the pygal.
The nuchal and the three anterior pairs of peripherals were missing.
The neurals are hexagonal, with the broader end forward, and nearly as wide as long.
The third is 44 mm. long and 44 mm. wide; the fifth 41 mm. long and 41 mm. wide; the sixth
41 mm. long and 34 mm. wide. They are each 6 mm. or 7 mm. thick. The anterior suprapygal

Fics. 196 AND 197.—Lytoloma wielandi. Carapace and sections of peripherals of type.

196. Carapace. X4. After Wieland. c.p.1,c.p.6,c. p.8, first, sixth, and eighth costals; c.s.1,¢. 5.4, first and
fourth costal scutes; f, lateral fontanels; m.s. 5, m.s.9, m.s. 12, fifth, ninth, and twelfth marginal scutes;
n.3, .6, third and sixth neural bones; nu. p, nuchal bone; mw. s, nuchal scute; per.2, per. 9, per-
11, second, ninth, and eleventh peripheral bones; py, pygal; spy.2, spy. 3, second and third suprapygal
bones; v.5.1, v. 5.2, first and second vertebral scutes.

197. Sections through middle of length of peripherals. 4. The numeral on each indicates the position of the
bone. The dotted line indicates the pit. py, section along middle of pygal.

is 37 mm. long and 80 mm. wide; the posterior, 60 mm. long and perhaps 80 mm. wide. ‘The
posterior articulated narrowly with the pygal.

The costals varied in width from 50 mm. to 60 mm. It is evident that the first costals
articulated with the nuchal at its outer extremities. Cope states that the nuchal of
L. jeanesi articulated with the first neural, but he says nothing about the articulation with
the first costals. The latter species possest a nuchal extremely narrow, little wider than
the first peripheral, and therefore quite unlike that shown in Dr. Wieland’s restoration.
However, as Dr.Wieland’s specimen lackt the nuchal and
the anterior peripherals, we do not know their structure

Width.
Peripheral. Length. —— and connections.
Upper face.Inner face. The eighth costal had its rib-end thrown back, so as
F _ 4 ie to entera pit in the eleventh peripheral, afeature common
6 72 3 22 in the Cheloniidz. As in the Cheloniidz, too, there were
8 80 56 15 extensive fontanels between the distal ends of the costals
ae 75 se 3 and the peripherals.

160 FOSSIL TURTLES OF NORTH AMERICA.

The peripherals have each three faces, an inner or visceral, a superior, and an inferior.
Each of them, from the fourth to the ninth inclusive, has a pit for the reception of the end of
arib. Fig. 197 from Wieland represents sections of these peripherals. It will be observed that
they grow broader and thinner from the front of the carapace. The dotted line in each repre-
sents the depth of the pit. The table, p. 159, gives the dimensions of some of the peripherals.

Dr. Wieland has described certain ossicles intercalated between the peripherals along the
free borders of his specimen. He suggests that these are a part of the disappearing osteo-
dermal covering of primitive turtles.

The carapace was covered with horny scutes, which have left distinct impressions of the
sulci on the various bones. There were, so far as appears, 5 vertebral scutes, 4 pairs of costals,
and probably 12 pairs of marginals and a nuchal. The vertebrals are strongly angulated
laterally where the sulci running down between the costals are
given off. The table herewith shows the dimensions of three
vertebral scutes.

How high on the costal bones the marginal scutes rose can

Vertebral. Length. | Width.

2 100 145 not be determined.
a 110 135 ke . -
5 a 2 There were preserved with this carapace some fragments of

the plastron, but not enough to permit a restoration of it. Wie-
land regards the plastron as having been more reduced than it
was in Osteopygis, but otherwise much like it. Small pits in the hinder half of the lower
inner free margin of the fourth peripheral show that the hyoplastron extended forward only
to it. There are no pits to show how far backward the hypoplastron extended.

The reasons for regarding this carapace as distinct from that of L. angusta are presented
under the latter species.

Genus ERQUELINNESIA Dollo.
Pachyrhynchus, Dotto, Bull. Mus. roy. d’Hist. nat. Belgique, 4, 1886, p. 130 (preoccupied).
Erquelinnesia, Dotto, Geol. Magazine (3), tv, 1887, p- 393-

Skull resembling that of Caretta caretta, but more elevated and descending more rapidly
in front of the orbits. Palate flat, bounded by low cutting-edges, and extending backward to
the hinder half of the roof of the mouth. Choanz in the hinder half of the roof of the mouth,
their anterior boundary formed by the palatines, which have met behind the palatal plate of
the vomer. Lower jaw not beakt. Shell resembling that of Caretta, but more rounded behind.

Type: Erquelinnesia gosselett Dollo=Chelone crassicostata Owen.

For the structure of the palate of this genus the reader is referred to Mr. R. Lydekker’s
figure of Lytoloma crassicostatum (Proc. Zool. Soc., London, 1889, plate vi). This figure
shows that the choanz are placed in the posterior third of the cranium and that the palatal
plates of the palatine bones meet each other in the midline behind the vomer and beneath the
narial passages. In the article accompanying this plate Mr. Lydekker states that Dr. Dollo’s
Erquelinnesia gosselett is identical specifically with Owen’s Chelone crassicostata. For refer-
ence to other views of the skull and to figures of the carapace of this species, and to the
literature, the reader is referred to Lydekker’s Catalogue of Fossil Reptiles, part 111, 1889,
page 60. On page 26 of this work is presented a figure of the humerus of E. crassicostata.
It is evident that the members of the genus had not yet developt a limb adapted for life on
the open sea.

The following species is assigned provisionally to Erquelinnesia on account of the great
length of the symphysis of the lower jaw. This seems to indicate that the choane were located
far toward the rear of the skull, so far that the palatines must have met behind the vomer. It
is probable that in Osteopygis the choanz were not removed so far toward the rear of the skull.

Erquelinnesia molaria sp. nov.
Figs. 198, 199.

This species is based on a lower jaw which is found in the collection of the Academy of
Natural Sciences of Philadelphia. It is labeled as being Lytoloma platyops, as having been
presented by Rev. L. H. Lighthipe, and as having been secured at Birmingham, New Jersey.
It has, therefore, been collected from the upper bed of the Cretaceous greensand.

THALASSEMYDID&. 161

This jaw (figs. 198, 199) is remarkable for the great length of the symphysis, this length
considerably exceeding that of Lytoloma angusta. The width of the jaw, at the mental fora-
mina, is 88 mm.; at the hinder ends of the dentaries, 100 mm.., dimensions almost exactly those
of the jaw belonging with the type of L. angusta. The length of the symphysis is 65 mm., that
of the jaw of L. angusta being 52 mm. In the latter species the hinder end of the symphysis
falls 12 mm. behind the line joining the mental foramina; in E. molaria it falls 22 mm. behind
that line. The triturating surface is flat to near the inconspicuous cutting-edges, to which
it ascends. The lower surface of the jaw also is flat, ascending rather abruptly to the cutting-
edges. Anteriorly the lower surface approaches gradually the upper surface at the sharp-
edged tip of the jaw. The outline of this tip
is truncated and about 20 mm. wide. The
coronoid process rises about 33 mm. above the
bottom of the ramus, and the descent from it
toward the tip of the jaw is gradual. The
masseter fossa is large.

The greatest thickness of the triturating
surface is near the hinder end of the symphysis.
The angle between the borders of the jaw, in
front, is considerably more than a right angle.

This jaw can not be that of Rhetechelys
platyops (Cope) for at least two reasons. The
angle between the lateral borders is too great
to fit the upper jaw of R. platyops. The type
of the latter species belonged to an individual
about twice as large as the possessor of the jaw
here described; and, if they belonged to the
same species, the angle of the jaw of the type of
R. platyops ought to be the larger. Again,in case
the present jaw had belonged to R. platyops,
the hinder end of the symphysis would have
AEE fallen a distance behind the choanz equal to the
Fics. 198 AND 199.—Erquelinnesta molaria. length of the palatal plate of the vomer. The

Lower jaw forming the type. 3. results of this would have been that a large part
of the triturating surface of the lower jaw would
have had no surface to oppose it and it would
have been applied against the choanz, thus interfering with breathing.

From both Lytoloma angusta and L. wieland: this species differs in the greater length of
the symphysis and in the smaller angle between the borders of the jaw.

198. Upper view of jaw. 199. Side view of jaw.

Genus RHETECHELYS nov.

Skull broad and deprest. Temporal region widely rooft over. Triturating surface of upper
jaw broad, involving the maxillz, the palatines, and the vomer. Choane near the middle of
the roof of the mou h:; the palatines not meeting behind the vomer. A pit between the pre-
maxillz for the reception of the upturned beak of the lower jaw. Shell and limbs unknown.

Type: Euclastes platyops Cope.

This genus differs from the species of Lytoloma (to which genus it has been referred since
the discovery that the name Euclastes is preoccupied) in having had the tip of the lower jaw
furnisht with an upturned beak. The existence of this is inferred from the presence of a deep
depression between the palatal plates of the premaxilla and an interruption of the bone.
Similar conditions are found in the skull of Macrochelys. Osteopygis, Lytoloma, and F rquelin-
nesia all have lower jaws with broad, flat triturating surfaces, but in none of them do we find
any traces of a beak. ; ;

The only known species of the genus was a large and powerful animal, whose skull equaled
in size that of the largest specimens of the living loggerhead.

Dy

162 FOSSIL TURTLES OF NORTH AMERICA.

Dr. W. B. Clark has referred provisionally (Johns Hopkins Uniy. Cire., xv, 1895, No. 45
Bull. U.S. Geol. Surv., 141, p. 59) some fragments of a large turtle to Euclastes. One of these
fragments has been again mentioned and figured by Dr. Case in the Eocene volume of the
Geological Survey of Maryland ( p. 97, plate x, fig. 7). The fragment is not susceptible of
generic determination.

Rhetechelys platyops (Cope).
Plate 29, figs. 2, 3.

Euclastes platyops, Corr, Proc. Acad. Nat. Sci. Phila. 1867, p. 41; Cook’s Geol. New Jersey, 1868
(1869), p- 7353 heer Naturalist, 11, 1869, p. 89; Ext. Batrach., Reptilia, Aves N. A., 1869, p.
149, plates vi, vii, fig. g; Vert. Cret. Form. West, re p- 259.

Lytoloma paapee Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 442.—W1kELAND, Amer. Jour. Sci.

(4), XvilI, 1904, p. 185.
?Propleura sopita, CoPE, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 140 (Harrisonville specimen).

All that we know at present regarding this species is what is to be derived trom the type
skull. This is in the collection of fhe Academy of Natural Sciences at Philadelphia. It was
found in a coarse granular limestone, at Hurffsville, Camden County, New Jersey. This
deposit belongs to ie Upper Cretaceous and was regarded by Cope as equivalent to the Fox
Hills group. The species formed the type of Cope’s genus Euclastes, a preoccupied name.

The oo was a large one, the total length being estimated by ‘Cope as II inches, about

280 mm.; but this must have included the supraoccipital process. At any rate, the length was
equal to that of the largest specimens of Caretta. The occipital condy le is missing, sett the
length from the premaxillae to this condyle must have been close to 200 mm., perhaps a little
more. The width, a short distance behind the orbits, is 220 mm. From this widest part the
aiteral outlines converge rapidly to the pointed snout. Beneath the orbit the outlines are
slightly concave. The “angle included between the borders of the maxilla is somewhat less
than a right angle. The roof is broad and deprest, the frontal region being flat. The slope
from the rear to the nasal opening is only slightly sinuous. There is no such sudden descent
from the orbits to the premaxilla as We see in the species of Glossochelys. The temporal region
was broadly rooft over, as in Caretta, but extended backward still further. The various bones
appear to have been disposed about as in the living genus mentioned.

The orbits look outward, forward, and upward. The upward inclination exceeds that of
Caretta. The greatest diameter of the orbit is 63 mm. The least interorbital width is about
5omm. The frontal bones are more produced forward than in Caretta, their suture measuring
55mm. They are excluded from the rim of the orbits by the union of the postfrontals with she
prefrontals. The latter bones meet along the midline a distance of 12 mm.

The nasal opening has a width of 30 mm. It looks forward and strongly upward. As in
other Cryptodira, the prefrontals send dow nward on each side a column of hone to the vomer.

The roof of the mouth resembles in general that of Caretta, but there are important differ-
ences. The cutting-edges of the cacclles are only feebly developt, descending but little below
the level of the grinding surface. This surface is formed by the union of the palatal plates of
the premaxillz, ivan. vomer, and palatines. It extends backward a distance of nearly
100 mm. from the premaxilla. It is somewhat concave on each side of the vomer and in the
premaxillary region. In the roof of the mouth the maxilla are each 41 mm. wide; the palatines
about 26mm. The vomer is 50 mm. long and 28 mm. wide.

The occipital condyle is missing, bar the choane fall within the anterior half of the length
to the roof of the mouth. They are bounded laterally by the palatines and anteriorly by dhe
vomer, the edge of this being g8 mm. behind the tip of the snout. They are thus quite different
from those of the species of Erguelinnesia. The palatal openings of the temporal fossa are
broader than long. The borders of the pterygoids were strongly emarginated.

Between the anterior ends of the premaxillz is a perforation supposed to be for the recep-
tion of a hook on the lower jaw, as in Macrochelys.

Professor Cope supposed that the whole length of the animal which possest this skull
was a little over 6} feet; but it is not safe to estimate the size of a turtle from the size of the
head. Nevertheless, it must have been a large and formidable brute. Probably it haunted
the coasts of the Cretaceous seas, betaking itself at times to some distance from the shore.

THALASSEMYDID&. 163

Its food has been supposed to have been hard-shelled animals, such as mollusks, which were
crusht between its mill-stone-like jaws. The possession of a hookt beak like that of the
alligator- snapper suggests, however, that the animal may have been accustomed to the captur-
ing of a more active prey, such perhaps as fishes.

Cope, as cited in the synonymy above, referred certain bones obtained at H: arrisonville,
Salem County, New Jersey, to Prople ura sopita. hese consisted, as he says, of 2 2 peripheral
bones, part of a costal, half a femur, and 2 phalanges. This lot is in the American Museum and
is found to include three peripherals, a fragment of a costal, and the distal end of a femur,
The foot bones are missing. The number is 2361. These bones quite certainly do not belong
to Osteopygis. In all specimens known to belong to the latter genus the pit for the rib-end is
placed at the middle of the length of the peripheral or not oe behind it. Only in the tenth
peripheral is it placed close to the hinder end of the peripheral. In the bones of the Harrison-
ville specimen the pit is placed far backward. Since Rhetechelys platyops was found in the
same limestone not many miles distant, the bones found at Harrisonville are referred provis-
ionally to the species just named.

One of the peripherals appears to be the left first. Its length is 85 mm.; its height 48 mm.
the thickness of the obtuse free border, 1g mm. in front. The articulation with the first oneal
was not strong and apparently only along the anterior end of the bone. It is not certain that
any part of the first vertebral scute descended on this peripheral. Another peripheral is prob-
ably the left fifth. The anterior end is broken off, but the length must have been about 110 mm.
From the hinder end to the intermarginal sulcus is 60 mm. The height of the upper face, at
the sulcus, is 62 mm.; the lower face, 53 mm.; the inner face, 50 mm. The pit is in the hinder
third of the bone. The upper face is slightly concave; the lower slightly convex; the inner
concave. The remaining peripheral 1 is probably the seventh. Cope regarded i it as the eighth.
Most of the outer border is broken away. The length is g5 mm.; the height, 79 mm.; the
thickness of the costal border, 28 mm. in front, 24 mm. behind. The upper surface Is some-
what concave; the lower, convex; The circular rib-pit is almost wholly in the hinder third
of the inner face. The piece of costal is 7 mm. thick at the sutural border. All these bones
are smooth, but markt by vascular grooves. The width of the femur at the distal end is 45
mm. The diameter of the shaft is 1g mm. The bone was considerably bent.

Family TOXOCHELYID Baur.

Skull somewhat deprest. Temporal region extensively rooft. Quadrate notcht for the
columella. Choanz situated well forward; not underfloored by the palatines. Palatines
extending forward to the vomers and forming the outer boundaries of the choanz. Carapace
with eleven pairs of peripherals, in addition to the nuchal and pygal. Nuchal not furnisht with
costiform processes. Epidermal shields present. Plastron loosely articulated with the carapace,
not extending forward to the third peripheral and backward hardly to the eighth. Fore foot
with at least 2 claws; the phalanges furnisht with condyles; the limb as a whole resembling
that of the Trionychidz.

Genera 2, Toxochelys and Porthochelys. With these may be included provisionally the
insufficiently known genus Cynocercus.

The writer excludes the members of this family from the Cheloniidz especially because the
fore limb had not yet become developt into a flipper like that of the modern sea-turtles. “The
humerus offers scarcely an approach to that of the sea-turtles. Nor was the hinder limb
nearly so much reduced as in the latter. The limbs were probably greatly like those of the
Trionychidz. That the anterior limbs were not habitually employed in swimming appears to be
shown by the fact that the shell was not excavated over these limbs as it is in the Cheloniidz.

Genus TOXOCHELYS Cope.

Skull longer than broad. No nasal bones. Carapace with large lateral fontanels. None
of the peripherals i in contact with the disk of the carapace. Midline with prominent carina,
rising at intervals into tubercles, some of which are distinct bones. Tail with a series of
comprest tubercles above. Plastron with median and lateral fontanels.

Type: T oxochel ys latiremis Cope.

164 FOSSIL TURTLES OF NORTH AMERICA.

The known species of this genus, 7 in number, are from the Niobrara deposits of Kansas.
All these species except T. bauri Wieland are based on parts of the skull; and this portion
of the skeleton is more commonly found than even the carapace, a rare circumstance in the
case of fossil turtles. However, the greater part of the shell and limbs is known from two or
three of the species.

From studies made on this genus some years ago (Field Columb. Mus. Pubs., Zool. ser.
1, 1896, p. 101) the writer concluded that the position of this genus is near the Cheloniidz, but
with evident relationships to the Chelydrida, constituting a distinct family, which is to be
called, as Baur has proposed, Toxochelyida. This conclusion has been confirmed by more
recent investigations made by Case, Wieland, and the present writer. The resemblances to
Chelydra are to be found especially in the anterior portion of the skull, in the structure of the
carapace, in the humerus and femur, and in the tuberculated tail.

The roof of the mouth is practically identical with that of Chelydra except that the palatine
extends forward to articulate with the vomer in front of the choane. The masticatory surfaces
of the two are equally flat, the cutting-edges of the maxilla are low in both, the choanz are
placed well forward and are not underfloored by processes from the palatines; and there are
in both genera large palatine foramina. On the other hand, as in the Cheloniidz, the tympanic
cavity has not yet entered the squamosal bone, the notch in the hinder face of the quadrate
remains open, and the back of the skull is extensively rooft over by the parietal, postfrontal,
and squamosal bones. As regards the carapace, it is evident that the nuchal resembles
more that of the Cheloniide, it having had no such long costiform processes as we find in the
Chelydride. Again in the presence of a surface for articulation with the spine of the eighth
cervical, as determined by Wieland, the nuchal resembles more that of the Cheloniidez. There
were 11 peripherals, as in Chelydra and most Cheloniide. The costal plates were less developt
than in the Chelydrida, even less than in any living Cheloniude, so that there are extensive
fontanels at the sides of the carapace. The elements in the midline appear to have resembled
more those of Chelydra, but there were peculiarities. There was a prominent carina, which at
intervals rose into comprest tubercles. The latter were distinct bones, which rested on the
contiguous portions of two neurals or suprapygals. The first rested on the first neural; the
second, on the second and third; the third, on the fourth and fifth; the fourth, apparently
on the seventh and eighth or on the eighth peripheral and the first suprapygal. If the fourth
was placed on the seventh and eighth neurals a fifth tubercle rested on the second suprapygal.
Wieland has named these ossicles “‘epineural spines,” but they are hardly to be thus homol-
ogized with the epineural bones of fishes. They were continued backward on the upper
surface of the tail as a series such as we find on the tail of Chelydra. The position of all these,
except the most anterior, was described and figured by the writer in 1898 (Amer. Naturalist,
XXXII, p. 936, fig. 2). Dr. Case was the first to observe the presence of one of these bones.
Wieland in 1905 (Amer. Jour. Sci., Xx, p. 331) describes a small bone on the first neural
which probably represents the first of this series of ossicles. Wieland in 1896 (Amer. Jour.
Sci., 11, p. 400) suggested that Archelon may have borne a series of dorsal spines; but as those
spines were believed to be horny and their existence only hypothetical, their discovery has
nothing to do with that of the bony spines. The writer has elsewhere presented his reasons
for believing that these tubercles represent the original dermal skeleton of the Testudines,
now retained only by Dermochelys (Amer. Naturalist, xxx, 1898, p. 929).

The writer presents here a description and figures (plate 30, figs. 1, 2) of a portion of a
carapace belonging to an undetermined species of this genus, remains which were collected
by Mr. H. T. Martin in Gove County, near Monument Rock, Kansas. Since this carapace
was not accompanied by any part of the skull, it was not possible to identify it specifically.

The specimen furnishes 15 peripherals, some fragments of costals, and a series of median
elements, of which 2 appear to be suprapygals. The median line of the carapace was occupied
by a strong and sharp keel. Anteriorly the right and left sides of this keel make about a right
angle with each other, but posteriorly they meet at a smaller angle, so that the keel is high and
sharp. At intervals the keel rises into comprest tubercles. These were in all cases originally
distinct bones, but most of them, especially posteriorly, have become co-ossified with the
supporting bones. The first neural appears to be wanting, together with the nuchal. There
is present I neural which does not furnish satisfactory contact with any of the others. There

TOXOCHELYID&. 165

are 3 others joined in their natural relation, and 3 more joined together and the hinder-
most united with the suprapygals. The single neural must belong in front of all the others.
It can not be the first one, because it is too thick in front for the nuchal, in case this was as
thin behind as in the genus generally; also because it is not crost by the sulcus separating the
first from the second vertebral scute. It can hardly be anything else than the second neural.
At the hinder end of the upper surface there is a half-facet for another bone, one of the series
of ossicles mentioned above. The neural which is regarded as the third has on its anterior
end a half-facet which completes the one on the supposed second neural. Behind this facet
is a sulcus, believed to be the one which divides the first from the second vertebral scutes.
The fourth neural has no tubercle of its own, but its hinder end supported a small part of
the tubercle which belongs to the fifth neural. This tubercle has a length of 20 mm. Behind
it is the sulcus which passes between the third and the fourth vertebral scutes. The tubercle
is wholly co-ossified with the bones on which it rests, but there are traces of the sutures. The
sixth neural is sharp along the midline, while its sides slope steeply, like a high-pitcht roof.
The seventh neural is short and closely joined to the eighth. A long and strongly comprest
tubercle occupies nearly the whole length of both these neurals and appears to be co-ossified
with both, only traces of the sutures remaining.
The suprapygals are co-ossified. The first is sharply rooft, while the next one has a rather
high and comprest tubercle. The anterior suprapygal appears to have been expanded on
- = ______ each side, but the expansions are broken away. The sulcus
between the fourth and the fifth vertebral scutes doubtless

Element. Length. Width. :

| ate crost behind the tubercle on the second suprapygal. The
| pygal is represented in plate 30, fig. 1. Its height is 14 mm.;
an ae ef F its width from side to side, 27 mm. Its upper, or anterior,
Rass 18 2B border appears to have articulated with a suprapygal which
| aS 28 24 isnow missing. The upper surface of the pygal is longitudi-
oe a z os nally grooved, while the inferior has a more extensive longi-

Sie eodlesetnie: 10 15 tudinal channel. This pygal is quite different from that

Ist suprapygal.. . 24 - of the type of I. stenopora. The dimensions of the neurals

2d suprapygal.... 31 13

and suprapygals are shown in the accompanying table.

It is evident that there were 11 pairs of peripherals, as
in most turtles. The two anterior are narrow and thin. These are followed by 4 others which
are thicker and broader, and these again by others which are thin. The table gives the
dimensions of the peripherals present. The width is taken at the front end.

The anterior end of the first peripheral is oblique for articulation with the nuchal. The
third and the succeeding peripherals to the ninth inclusive have each a pit for a corresponding
rib-end. The tenth has no pit. The eleventh is not present. Since the hinder end of the
tenth peripheral is 19 mm. wide and the articular end of the pygal only 12 mm. wide, it follows
that the eleventh was considerably wider at one end than the other. All the peripherals are
crost by shallow sulci.

Dr. Wieland has represented (Amer. Jour. Sci., XX, 1905, p. 335, fig 6; here reproduced
as fig. 229) the rib-end of the eighth costal as entering a pit in the anterior end of the eleventh
peripheral. The end of the rib was not present and it is

Width

ae stated that the rib-pits are all small. In the specimen
Peripherals.| Length. i; Thickness. ea : : =
upper face. ficured by Dr. Case (Univ. Geol. Surv. Kans., 1v, 1898)
5 . y .

: ee is the eighth costal comes down to a thin edge and there
2 26 ir “ appears to have been no rib-end. Moreover, Case states
3 30 8 12 that the eleventh peripheral has no groove nor pit for a
ee S F Pr rib. At my request Dr.C. E. McClung, of the University

S ) * -T7 ‘ * « = n r
6 38 15 10 of Kansas, examined this specimen. He finds the pygal
36 i : and the eleventh peripheral in their natural positions and

32 i . ‘s -
9 a a Be the eighth costal with a sharp border and no trace of a
Io 32 16 75 rib. Case is probably in error in representing the rib of

the seventh costal plate as going to the tenth peripheral.
The plastron appears to have resembled quite as much that of the Cheloniidz as it did that
of Chelydra. As in the former family, that part of the plastron which lay between the fore and

166 FOSSIL TURTLES OF NORTH AMERICA.

hind legs was much broader than it is in the case of Chelydra; and, as in the sea-turtles, there
was a fontanel between the outer end of the hyoplastron and hypoplastron. There was also
an extensive umbilical fontanel. The bones of the right and left sides were joined along the
midline more like those of Chelydra than like those of the Chelonide. The epiplastron and
entoplastron are figured by Wieland (Amer. Jour. Sci., XX, p. 336, figs. 7,8). The former are
slender, the latter broad and lance-shaped. The xiphiplastron, as represented by that of
T. stenopora (Case, op. cit., plate Ixxx., fig. 5), is slender and apposes digitations to its fellow.

Cervical vertebra have been figured by Dr. Case (op. cit., plate Ixxxiu, figs. 2-4). These
were more or less injured, being comprest laterally. A more complete series is in the Marsh
collection at Yale, and these have been described by Dr. Wieland (Amer. Jour. Sci., XIv, 1902,
p. 102). According to this author, the anterior 5 have their articular ends fashioned as in
Chelydra and the great majority of turtles; that is, the first is composed of 4 bones; the
centra of the second and third are convex in front and concave behind; that of the fourth is
convex at both ends, as in turtles generally. The next four centra are concave at the anterior
ends, convex at the posterior. Toxochelys differs from modern Cheloniide in not having the
double concayities developt on the anterior end of the last cervical. The specimen furnishing
these cervicals was not accompanied by the carapace, so that we can not estimate the length of

Fic. 200.—T oxochelys latiremts. Front limb. .28. Specimen in Yale Univ. coll.

a, head of humerus; 6, radial process; c, ulnar process; cen, centrale; e, ectepicondylar groove; g, entocondyle;
hum, humerus; int, intermedium; /, pisiforme; rad, radius; ul, ulna; u/n, ulnare; I, I, etc., metacar-
pals; 1, 2, 3, etc., distal carpal bones. Figure by Wieland.

the neck relatively to the shell. The estimated length of the neck is 226 mm. The skull was
114 mm. to the occipital condyle.

Regarding the caudal vertebre little that is certain is known. It is not at all improbable
that the vertebra which were described by Cope under the name Cynocercus incisus belong to
Toxochelys. Two caudals are in a small collection of bones received from the University of
Chicago, with the catalog number 230 and belonging to Toxochelys latiremts. The centrum
of one is 18 mm. long. These vertebrae probably belonged toward the end of the tail. They
are proccelous and possess short lateral processes. In general these vertebra resemble those
of Cynocercus, but the cup is deeper and without sign of the perpendicular incision seen in
Cynocercus, and the ball is more prominent.

The coraco-scapular arch is more like that of the sea-turtles than like that of the snappers.
The coracoid is long, narrow, and spatulate. A considerable neck is interposed between the
glenoid fossa and the base of the proscapular process.

The fore limb is best known from a specimen in the collection at Yale (fig. 200), which
has been described by Dr. Wieland (Amer. Jour. Sci., X1v, 1902, p. 95, fig. 1). The humerus
has also been figured by Dr. Case. Dr. Leidy also has figured the proximal end of the humerus
of what is no doubt a member of this genus (Cont. Ext. Vert. Fauna West. Terrs., 1873, plate
xxxvi, fig. 17). For a figure of the humerus of T. latiremts ‘see fig. 200, shown above. This
specimen was accompanied by the lower jaw, and its identification thus made certain.

The humerus of Toxochelys is regarded by Dr. Wieland as representing the form which
he has called ‘‘thalassoid,”’ especially because he believes that the radial process has descended
lower on the shaft than it is in Chelydra and that the ulnar and radial processes have moved

TOXOCHELYID. 167
/

nearer their respective borders of the humerus. ‘To the present writer the principal changes

which have affected the thalassic and parathalassic humeri, as represented by Caretta ane

Dermochelys, are to be found in the straighte ning of the shaft; the change of the head from a

position looking upward, in the natural position of the bone, to one iGokine toward the median

plane of the animals the descent of the radial process, on the shaft; the transference of this
process, or of a component of it, toward the radial border; and the removal of the condyles
for the radius and ulna and of the ectepicondylar foramen or groove toward the ulnar border of
the bone. Of all these changes none seems to have taken place in Toxochelys, except a slight
descent of the radial process. In every other respect the bone retains the characteristics of

Chelydr a.

In many other features the fore limb of Toxochelys has made approaches to the flipper of
the marine turtles, as Dr. Wieland has shown. The ulna, as compared with that of Chelydra,
has become shorter relatively to the humerus while the radius has
become longer, as it has also to a greater degree in Caretta. The ulna
has become shorter than the radius, and the third and fourth fingers
have become greatly elongated; but in these respects it is far behind
Caretta. The first and second fingers retain about the same ratio to
the humerus that they have in Chalyara: Taken altogether, the limb
may be regarded as standing between that of Chelydr a and the sea-
turtles but nearer to that of C helydra. From the fact that the head of
the humerus had the position that it has in the freshwater turtles and
that the phalanges possest well-developt condyles we may be quite cer-
tain that the species of Toxochelys had no difficulty in getting about
on the land.

The first and second fingers of Toxochelys were composed of
phalanges which were much stouter than those of the other fingers.
The terminal phalanges were encased in horn and formed strong
curved claws. The other fingers did not probably extend beyond the
border of the skin. Dr. Case (op. cit., plate Ixxxii, figs. 1, 2) repre-
sents the first finger as having 3 phalanges. This figure is evidently
that of the second finger.

Fic. 201.—Toxochelys The following measurements are taken from Dr. Wieland’s des-
sp. indet. “Vibia, fb- cription of the fore limb in Yale University Museum (fig. 200): Length
ula, and some foot ¢ : és ee ere S : u
aes of humerus, 135 mm.; radius, 75 mm.; ulna, 66 mm. 3 total length

4 of the first fnger, 65 mm.; of second finger, 95 mm.; of third finger,

estimated, 130 mm.; of fourth finger, estimated, 135 mm.; of fifth finger, estimated, go mm.

The pelvis is somewhat more like that of Caretta than like that oe Chelydra. Dr. Case
has given figures of the ilium (op. cit., plate Ixxxi., fig. 8) and of the ischium (op. cit., pl. Ixxxi,
fig. 6). The antero-lateral processes of the pubis are broader than they are in Chelydra.

The femur is not an uncommon bone in collections of Toxochel ys materials. Figures of

the bone are presented by Case (op. cit., plate Ixxxi) and Leidy (op. cit., plate xxvi, fg. 18).
Unfortunately the bone is usually crusht, so that its exact form is questionable. It is certain,
however, that the greater and the lesser trochanters were separated by a deep fossa, as Case
has dascrived the bone. This fossa was probably like that found in Chelydra. In Caretta
and again in Testudo this fossa 1s nearly obsolete. Case believed that the femur was a weaker
bone than the humerus. This view is probably correct, and is corroborated by the relative
izes of the humerus and femur figured by Leidy. It is not certain, however, that these bones
belonged to the same individual. ite G helydr athe femur is the longer bone.

Whe tibia and fibula are not well known. There is presented i in fig. 201 a portion of the
hinder limb in the possession of the author and believed to belong to T oxoc helys. The tibia
and fibula are elongated and slender, more like those of Chelydra than like those of Caretta.
Four tarsals are present. The metatarsal is probably that of the first toe. Case (op. cit., p. 378
describes the hind foot of an incomplete specimen, but the error 1s made of assigning pik
phalanges to the first digit. The digit may have been the second, including the metatarsal.
The terminal claw was strong and eiuck curved. The phalanges of the remaining digits were
longer and slenderer, and the terminal one did not support a claw.

168 FOSSIL TURTLES OF NORTH AMERICA.

Key to Species oF TOXOCHELYs.
A. Species based on skull.
a. Symphysis of lower jaw short, about one-fifth of length of lower crushing-surface of jaw.
b. Snout rather pointed.

c. Jaws slender and weak; symphysis thin, sloping on upper surface........ latiremis
cc. Jaw rather heavy; the upper surface of the symphysis horizontal ........ Serrtfer
bb: Snout, broad and! rounded sacs meters te ete tee erate erates brachyrhina

aa. Symphysis long, at least one-third the length of the crushing-surface.
d. Nasal opening narrow; upper surface of the symphysis sloping....... steno pora

dd. Nasal opening normal; symphysis flat above.

@: Skull as" broadtastlong tacts locust tot asi teeters avofored Se elkader
ée:*Skull@longer:thanmibroad: seers se eee es ce ett aeee Estee arise = procax
AA=Speciés. based’ on: shellfouly:,. 2/23 wteerrs te octetatenee eee eee ear Petey baurt

Fics. 202-205.—T oxochelys latiremis. Skulls and lower jaw. +.

202. Upper view of front of skull. No. 1496 A.M.N.H.

203. Upper view of skull. No. 1497A.M.N.H. at, atlas; ax, axis; sg, squamosal.

204. Lower view of same skull as preceding. at, atlas; ax, axis; qu, quadrate; sq, squamosal.
205. Dentary portion of lower jaw, with section along the symphysis. No. 1497 A.M.N.H.

Toxochelys latiremis Cope
Figs. 200, 202-206.

Toxochelys latiremis, Cope, Proc. Acad. Nat. Sci. Phila. 1873, p. 10; Vert. Cret. Form. West, 1875,
pp- 98, 260, pl. viii, figs. 1, 2; Proc. Amer. Philos. Soc., xvit, 1877, p. 176.—Hay, Pubs. Field
Columb. Mus., Zool., 1, 1896, p. 101, pls. X1v, xv; Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 4423
Bull. Amer. Mus. Nat. Hist., xx1, 1905, p. 177-—CaseE, Univ. Kansas Geol. Surv., 1v, 1898, p. 371,
plate Ixxix; plate Ixxx, figs. 1,2; ?plate Ixxxi, figs. 1-8, 10-13; ?plate Ixxxil, figs. 1, 2; plate Ixxxiii,
figs. 2-4.—Wacner, Kansas Univ. Quarterly, vir, A, 1898, p. 201, fig. 1—WieLanp, Amer. Jour.
Sci. (4), XIV, 1902, p- 95, figs. I, 2.

Cynocercus incisus, LEIDY, Cont. Ext. Vert. Fauna West. Terrs., 1873, p. 279, plate xxxvi, figs. 17-21.

The type of the present species consists of a portion of the lower jaw and a coracoid, of
the Cope collection of reptiles and fishes, and is now in the American Museum of Natural
History, New York, having the number 2362. The specimen was collected by Professor

res

TOXOCHELYID&. 169

B. F. Mudge, in the Niobrara deposits of Kansas, near the forks of the Smoky Hill River.
The animal was a large one, since the mandible, from the symphysis to the angle of the jaw,
measures 157 mm. In 1877, as cited in the synonymy, Professor Cope came into possession
of 2 nearly complete skulls, which he identified as belonging to 7. latiremis, and these he
described. These skulls are now in the American Museum and bear respectively the numbers
1496 (fig. 202) and 1497 (figs. 203, 204). The latter (and probably both specimens) was
collected somewhere along the Smoky Hill River. A comparison of the lower jaws of these
skulls with that of the type makes it certain that the former were correctly referred.

The first publisht figure of the skull of this species was made by Hay, as cited. This
skull lackt the lower jaw; but a comparison with the skulls described by Cope reveals no
differences. Other skulls have been figured by Case and Williston, as cited.

This appears to have been the commonest turtle in the Niobrara beds of Kansas, yet many
parts of its skeleton remain unknown. ‘The size attained was considerable. If the length of
the coracoid bore the same relation to the length of the carapace that subsists between these
bones in Chelydra or Caretta, the carapace must have been about a meter in length. It may be
remarkt here that the coracoid of Cope’s type was 225 mm. long, that author’s statement
that it was 250 mm. being incorrect. The ramus of the mandible has a length of 157 mm., so
that the skull, from the tip of the snout to the occipital condyle, was close to 160 mm.

The skull of this species is broad posteriorly.
In front of the quadrates the width is gradually
reduced, so that the head is wedge-shaped and
the snout pointed. Altho all the skulls yet found
are considerably flattened by pressure, it is quite
certain that the head was rather deprest, more
like that of Chelydra than like that of any of the
living Cheloniide. The supraoccipital is long.
The temporal region is rooft over about as in
Caretta, and the squamosal appears to have come
into narrow contact with the parietal. The orbits
lookt upward and outward, resembling more
those of Chelydra than those of the Cheloniidz.
The opening of the anterior nares is large, con-
trasting strongly with that of 7. stenopora. The
tympanic cavity did not extend into the squa-
mosal, but had the stage of development seen in
the loggerhead. The cutting-edge of the maxilla
is moderately high anteriorly, but becomes very
low at the hinder end. As seen in profile, it is convex. There is a rough ridge on the palatine
near its articulation with the maxilla. The alveolar, or masticatory, surface of the upper jaw is
somewhat concave from side to side. Including the ridge on the palatine, this surface is not
so wide as is the fossa containing the choane. There are large posterior palatine foramina.
The narrowest portion of the palate, across the pterygoids, is rather wide compared with the
other species, and is flat. More posteriorly each pterygoid bears a groove which is directed
outward and backward toward the hinder border of the quadrate.

The lower jaw is relatively weak. The alveolar surface is narrower than in the other
species in which it has been observed. Fig. 205 represents the lower jaw belonging to
specimen shown in figures 203 and 204. The outer edge is sharp and rises somewhat above
the inner edge. The latter rounds off into the inner face of the jaw, which face is in no
way hidden by the surface referred to. At the symphysis the alveolar surface extends back-
ward little more than one-half as far as does the lower face of the bone. The tip of the jaw is
slightly beakt.

Notwithstanding the fact that a considerable number of skulls of this species have come
to light, portions of the carapace or plastron are rare. Wieland (as cited) mentions portions
of the carapace and plastron in Yale University, but he does not describe them.

The cervical vertebra and some caudals have already been described in the discussion
of the genus. No other vertebra are known.

Fic. 206.—Toxochelys latrremis. Scapula and
coracoid. 4. Redrawn from figures by Case.

170 FOSSIL TURTLES OF NORTH AMERICA.

For description of the shoulder-girdle (fig. 206, from Case) and remarks thereon, see page
166. The structure of the anterior limb has also been described and illustrated.

No pelvis definitely known to belong to this species has been described. References to
femora supposed to belong to this species have already been given, but these may have belonged
to other species, as 7. procax or T. brachyrhina. Case (op. cit., p- 378) describes a hind foot
which he refers to 7. /atrremis. This has already been mentioned on page 167.

Wagner has described and figured a portion of a skull of a turtle from the Pierre shales
of Kansas, which he identifies as 7. /atiremis. The present writer has not seen this skull.
The lower jaw figured by Wagner certainly does not belong to T. /atrremus.

Toxochelys serrifer Cope.
Figs. 207-213.
Toxochelys serrtfer, Cope, Vert. Cret. Form. West, 1875, p- 299.—Hay, Bibliog. and Cat. Foss. Vert.
N. A., 1902, p. 442; Bull. Amer. Mus. Nat. Hist. xx1, 1905, p. 178, figs. 1-7.
The type of this species is No. 1835 of the Cope collection of reptiles and fishes in the
American Museum of Natural History, New York. It consists of the greater portion of both
maxilla, the left dentary, the greater portion of the pterygoids, the right quadrate, the frontals

Fires: 207-212.—T oxochelys serrtifer. Portions of skull of type. XT.

207. Left dentary. Shows cutting-edge and grinding- 210, Cutting-edge and grinding-surface of upper jaw.
surface. mx, maxilla; pal, portion of palatine.

208. View of inner face of dentary. 211. Base of skull. boc, basioccipital; pt, pterygoid.

209. Symphysis of lower jaw. 212. Upper aspect of skull. fr, frontals; pa, parie-

tal; prf, prefrontal.

and prefrontals, and two peripherals. “They were collected somewhere in the Niobrara deposits
of Kansas by Professor Merrill, in 1865.

The dentary (figs. 207-209) had not yet become co-ossified with its fellow. Its length is,
as Cope states, 48 mm.; its width above, g mm.; the depth of the inner face, 7 mm. Longi-
tudinally the alveolar surface is more strongly concave than in J. latiremis. Near the sym-
physis the surface is considerably concave transversely, but posteriorly it is nearly flat. The
inner border of this surface is nearly on the same level as the outer. At the symphysis (fig. 209)
the alveolar surface extends nearly as far backward as does the lower face of the bone. The
inner face of the dentary is occupied by a broad groove. The length of the alveolar surface of
the symphysis is g mm.

Slightly more than the posterior half of each maxilla (fig. 210) is present. The alveolar
surface is flat, and the cutting-edge retains its height to its hinder end. In I. latiremis the
height becomes reduced posteriorly. The pterygoids (fig. 211, pt) present no peculiarity.
Where narrowest the portion of the palate formed by the pterygoids is 15 mm. wide. The
quadrate does not differ from that of 7. latiremis, except that the articular surface for the

©OXOCHELYID&A. LAL

lower jaw is much smaller. This surface is triangular, the inner lobe seen in T. latiremis
being greatly reduced in T. serrifer.

The interorbital space (fg. 212) had a width of 16 mm. where narrowest. ‘The groove on
the under surface of the frontals for the olfactory nerve is relatively narrower chan in 7.
latiremis, in which the groove is nearly one-third as wide as the interorbital space; whereas,

ek in T. serrifer it is only about one-sixth the width of that space. The
Ne anterior borders of the prefrontals are broken away, so that the
wn width of the anterior narial passage can not be determined. It is

certain, however, that the nasal cavity itself had the lateral extent
that it had in 7. latiremts.

An estimate shows that the length of the skull from the snout to
the occipital condyle was about 80 mm.

Two adjacent peripheral bones are present, probably the left
eighth (fg. 213) and the ninth. The eighth is 40 mm. long and 32
mm. ae the ninth 43 mm. long and 32 mm. wide. Each is notcht
just behind the widest portion and here the width of the eighth is 2
mm., of the ninth 27 mm. The thickness of the inner fre is nearly
7 mm., and at the hinder end of this face is a pit for a rib.

The specimens which were referred to this species by Case (Univ.
Geol. Surv. Kan., rv, p. 379) are described as 7. stenopora. From
the latter species ie serrifer differs in having a dentary with an
alveolar surface much wider in proportion to its “depth, and not beakt
at the tip.

It is evident that the skull (and probably the whole skeleton) of T. serrifer was much larger
than that of 7. stenopora. This makes it all the more remarkable that the dentary of the
former is relatively so short and that the depth of 7. stenopora is so great. It seems not im-
probable that the carapace and part of the plastron described by Wieland as 7. hauri will
prove to belong to the present species.

Fic. 213—Toxochelys ser-
rifer. One peripheral
and part of another.
Tie

Toxochelys brachyrhina Case.
Plate 31, fig. 1.

Toxochelys brachyrhinus, Case, Univ. Geol. Surv. Kansas, tv, 1898, p. 378, pl. Ixxxiv, figs. 1, 2—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 442; Bull. Amer. Mus. Nat. Hist., xx1, 1905, p. 177.

The type of this species is a skull, the property of Kansas University, and bearing the
number 1212. Dr. Case’s description of it is exceedingly brief. The character which he gives
as distinguishing it from 7. /atiremrs is the much blunter snout. Case’s fig. 1 of his plate i is
three- faurche of the natural size; and, while the form of the skull is shown, the details are not
well represented. His fig. 2 is a restoration of the size of nature, but it does not indicate the
sutures; likewise it represents the anterior half of the skull as somewhat too broad.

The skull of this species appears to be distinguisht from that of 7. /atiremis in being
narrower posteriorly in relation to the length and in having a broader snout. Another distin-
guishing character seems to be found in the narrower posterior region of the palate. In the
case of a large specimen of 7. Jatrremzs, 130 mm. from the snout to the occipital condyle, the
pterygoid portion of the palate, where narrowest, is 36 mm. wide. Inthe type of T. brachyrhina,
117 mm. to the occipital condyle, the palate is only 20 mm. wide. The interorbital space also
is relatively narrower than in T. latiremis. In the specimen of the latter referred to, the space
between the orbits is 24 mm. wide, in T. brachyrhina, only 19 mm.—too great a difference to
be due to difference of size alone.

The following measurements are given of the type specimen:

Millimeters.

Length from the snout to the occipital condyle. .................005. 117
Length to extremity of supraoccipital bone. . 134
Distance between the outer faces of quadrates. F go
Distance between outsides of squamosals... . ; : O+
Width at hinder borders of orbits.......... ; ; 80

Width at front of orbits........ Me cin se shy ian ye Gara tA. t- L50

172 FOSSIL TURTLES OF NORTH AMERICA.

The anterior nares do not appear to have been different from those of 7. latiremis. As
seen in the type and the figures here presented, the quadrates have been squeezed forward
somewhat. The lower jaw is present, but is so closely prest against the roof of the mouth
that its alveolar surface can not be seen. So far as can be judged, it is not greatly different
from that of J. Jatiremis; but the symphysis is evidently shorter. It is very desirable that
this surface should be seen, in order to distinguish this species clearly from T. serrifer.

In explanation of the figure, it should be said that the inner nares are hidden by some
fragments of bone, probably of the hyoids.

The type was found in the Niobrara deposits of Gove County, Kansas.

Fics. 214-220.—T oxochelys stenopora. Portions of type.

214. Dentary portion of lower jaw. XI. 218. View of palatal surface of skull. Xr.

215. Left dentary, showing inner face. X1. 219. Supraoccipital. X1.

216. Section along symphysis of lower jaw. 1. 220. Left hyoplastron, hypoplastron, and xiphiplastron
217. Upper aspect of skull. X1. fr, frontal; mx, of type. X4. Redrawn from figure by Case.

maxilla; pa, parietal; pal, palatine; pmx,
premaxilla; prf, prefrontal; pr, pterygoid.

Toxochelys stenopora Hay.
Figs. 214-220.

Toxochelys serrifer, Case, Univ. Geol. Surv. Kansas, 1v, 1898, p. 379, plate Ixxx, figs. 3-9; plate Ixxxii,
figs. 4, 5; plate Ixxxiii, fig. 1—Hay, Amer. Naturalist, xxx, 1898, p. 935, figs. 1-3; Bibliog. and
Cat. Foss. Vert. N. A., 1902, p- 442, in part.—WILListon, Trans. Kansas Acad. Sci., Xvi, 1901,

. 198.

Poschaie stenoporus, Hay, Bull. Amer. Mus. Nat. Hist., xx1, 1905, p. 180, figs. 8-12.

The present writer is not able to agree with Dr. Case in his identification of the testudinate
remains belonging to the University of Kansas which he has described and figured as T ox-
ochelys serrifer. The type of Cope’s T. serrifer belongs to the American Museum of Natural
History and was not accessible to Dr. Case when he was studying the fossil turtles of Kansas.

Of the bones figured by Case, the skull (plate Ixxxii, figs. 4, 5), the marginals (fg. 1,
plate Ixxxiii), and the hyoplastron (fig. 3, plate Ixxx), are markt with the number 2060; while
the elements furnishing fig. 4 of the last-named plate, and the neurals and suprapygal of fig. 1,

TOXOCHELYID. 173

plate Ixxxiii, belong to No. 1270. There appears to be no reason for doubting that these bones
all belong to the same species.

The principal differences between the present species and Cope’s T. serrifer must be sought
in the form of the lower jaws and of the peripheral bones. Unfortunately we can not determine
= ane: the form of the anterior nares of T. serrifer.
Toxochelys Toxochelys Lhe lower jaw of T. serrifer shows no indica-

ee :
a serrifer. | stenopora. tions of a beak, while that of 7. stenopora

Ss = —— (figs. 214-216) is plainly beakt. Case recog-
Length from tip of jaw to hinder end nized this difference. The table herewith
ce eee ma BON Oteaaes 48 33 presents the dimensions of the two jaws.
| Width of grinding surtace.......... 9 6.5 : 7

Winter iiss face at riddle of It is seen from these measurements that,
Wet encte eee eens > 4 although the lower jaw of T. steno pora, as
| Whole depth of jaw at middle ...... 8 9 represented by the masticatory surface, is
Length of symphysis on upper surface 10 11.5

much shorter than that of T. serrifer, the jaw
is nevertheless deeper, the inner face of equal
depth, and the symphyseal line of the masticatory surface longer. The width of the inner
face of T. stenopora may be somewhat greater than the figures indicate, since there is evi-
dence of some downward crushing. The symphyseal line above slopes downward and back-
ward in J. stenopora; in T. serrifer, it is nearly horizontal.

The peripherals of T. serrifer are much broader and flatter in proportion to their length
than in 7. stenopora. Thus, in comparing what appear to be the eighth peripherals, we find
that of 7. serrifer measuring 49 mm. in length and 32 mm. in width, while that of T. steno-
pora is 23 mm. long and 10 mm. wide.

The bones bearing the number 2060 of Kansas University museum are made the type
of the present species, and in case it should be found that the skull and the other bones of
2060 are not all of the same species, the former is to be regarded as the type.

As will be seen from the figures (figs. 217, 218), the skull has been damaged, especially the
hinder portion. Nearly the whole of the roof of the temporal region is missing. The quadrates
and the supraoccipital are present, but detacht from the rest of the skull. Dr. Case’s figures
represent the skull as larger by one-half than the originals; but this has probably been due to
the failure of the engraver to reduce the original drawings.

The skull was evidently short and bredd. The Hecance between the hinder ends of the
maxillz equaled the distance from the snout to the middle of the basisphenoid; whereas in
T. latiremis the distance between the extremities of the maxillz extends only to the narrowest
portion ct the pterygoids. The length of the skull to the hinder border of the basisphenoid is
46 mm.; to the occipital condyle was probably about 10 mm. more; while the length to the
hinder end of the supraoccipital bone was about 82 mm. The palate, where narrowest, 1s
10 mm. wide; the interorbital space, 13 mm. The alveolar surface of the upper jaw, including
the rough ridge on the palatine, is rue ely broader than in 7. lJatrremzs, being contained in
the length of the cutting-edge 3 times. In T. latiremis it is contained 4 times. This increase
in the width of the surface appears to be at the expense of the fossa for the choanz, which is
but little wider than the surface referred to; whereas in 7. latiremis the fossa is much wider.
In the wideness of the alveolar surface and the narrowness of the fossa the present species
resembles TJ. procax.

There were without doubt posterior palatine foramina, as in the other species of the genus.

That which distinguishes this species from all others of the genus, so far as known, is the
narrowness of the anterior nares. ‘This slit-like opening is evidently natural, or due only very
slightly to any compression during fossilization. The skull is flattened somewhat by pressure,
from which condition we may conclude that the narial opening originally had possibly a more
perpendicular position than at present.

A portion of one parietal bone is among the remains of the skull. It presents a part of
the roof of the temporal region. The supraoccipital (fig. 219) has a length of 35 mm. and a
maximum height of 16 mm., being thus relatively long and high.

This skull is accompanied by the pygal and nearly all of the peripherals of one side. Some
of these have been figured by Dr. Case (op. cit., plate Ixxxiii, fig. 1). The pygal has a sharp
posterior border and a rounded anterior border. From the latter there springs a process which

174 FOSSIL TURTLES OF NORTH AMERICA,

has joined the hindermost suprapygal. Above and below, the pygal is broadly grooved from
front to back. The most anterior peripheral is thin and narrow. The second is only slightly
wider. The third has its inner face more developt and possesses a pit which received the
extremity of the rib of the first costal plate. The inner, or costal, face of the succeeding periph-
erals increases in breadth, until a section of the bone is a nearly equilateral triangle; then
the face is reduced, so that at about the eighth the bone has grown quite thin and flat and
relatively broad. Each peripheral, except the first and the orcad has a pit for the reception
of a rib- end, until we come to the tenth. t

Ordinarily in turtles the eighth costal plate sends its rib to the tenth peripheral, but in
T oxochelys the eighth costal plate i is short and its rib does not extend beyond the border of the
plate. As in Ghelyar a and most other turtles, there is no rib-end reaching the eleventh periph-
eral. In the Cheloniide the rib of the eighth costal plate is turned Backward/to eis periph-
eral, one of the more anterior peripherals not receiving a rib. However, Wieland represents
the rib of the eighth costal plate as entering a pit in the eleventh peripheral. See fig. 235 of
the present eg

No. 1270 of the Kansas University museum furnishes a number of costal plates, a few
neurals and the anterior suprapygal bone. ‘These are represented in Case’s figure already
referred to. According to the present writer’s views, another peripheral ought to be inserted
between the last one of that figure and the pygal; and there was almost certainly at least one
suprapy gal behind the one eee represented. The neural which Dr. Case has called the ninth
is certainly the eighth, since it has articulated with it the eighth costal. Resting partly on this
neural and the fet suprapygal is a comprest tubercle at the base of which is a ican suture.
The neural seen in front of the one just referred to is probably in its correct position; but the
next one in front is certainly wrongly placed, being probably the fifth. The facet on the anterior
end of the upper surface of the sixth has undoubtedly supported a tubercle similar to the one
resting on the eighth neural.

ae midline of the carapace of .T. ste nopora was traverst by a sharp and tuberculated
keel, such as has been described as occurring in the specifically undetermined species (p. 164).
As in that form, the more anterior tibeccles were connected with their underlying bones by
open sutures. The elevation of the shell was probably about the same that we find in Chelydra.

In the figure presented by Dr. Case, the costal plates are probably correctly placed ‘with
reference to one another. As will be seen, there were large fontanels between the distal ends
of the ribs.

The plastron i is represented by fig. 220, reproduced from Dr. Case’s work so often quoted.
Nothing is known regarding the entoplastron and epiplastron. There was a large umbilical
foneanel. while there was, on each side, another fontanel bounded by the peripherals outwardly
and by the hyoplastron and hy poplastron i in front and behind. The lateral digitations of the
plastral bones did not enter into pits in the peripherals. The median digitations probably
approacht closely those of the opposite side. A prominent longitudinal ridge on each side
crost the hyoplastron and hypoplastron.

Toxochelys elkader sp. nov.
Figs. 221-223.

Of the type of this species, No. 6137 of the American Museum of Natural History, there
were secured the skull nearly complete; large portions, perhaps the whole, of the plastron;
the shoulder-girdles; portions of the pelvis; aad apparently one or two peripherals. Excepting
the skull, the parts have not yet been prepared for study. The specimen was found in the
Niobrara beds, near Elkader, Logan County, Kansas, by Mtr. H. T. Martin, of the University
of Kansas.

The skull, like most specimens found in the Niobrara beds, is somewhat crusht. The
length from the snout to the occipital condyle is 105 mm.; to the end of the supraoccipital
spine, 143 mm. From the outside of one quadrate to that of the other is 101 mm. The outline
of the skull, from a little in front of the quadrate, is nearly straight to the rather pointed snout.

Both squamosals (fig. 221) are missing, but it 1s probable that each sent upward a process
to the parietal. The latter bones are complete. The jugal extended nearly to the pedicel of the

TOXOCHELYIDE. 175
quadrate. On the right side the whole of the quadratojugal is missing, but on the left most of
it 1s present, but crusht. The interorbital space is 22 mm. wide. The orbit has an antero-
posterior length of 38 mm. The nasal opening is 15 mm. wide,

The pterygoid portion of the palate (fig. 222), where narrowest, is 20 mm. wide, being
narrower than in 7. latiremis. The distance between the ends of the pterygoid processes is
46 mm.; whereas, in 7. latiremis of the same size, the distance is 53 mm. The postpalatine
foramina have a diameter of 5 mm.; those of 7. Jatiremis, a diameter of 13 mm.

Fics. 221 AND 222.—Toxochelys elkader. Skull of type. x4.
221. Upper view. 222. Lower view.

The choanz are slightly further from the snout than in 7. /atrremzs, the anterior boundary
being 28 mm. away. This region is constructed much as in 7. procax, but the choanz are
relatively nearer the snout. The triturating surface of the upper jaw is 21 mm. wide, including
a roughened ridge 5 mm. wide on the palatine.

halower | jaw (fig. 223) is apparently somewhat crusht downward. It is complete, mere
that both articulars appear to be missing. The triturating surface looks directly upward, i
slightly concave transversely, and its inner border ov erhangs the inner face of the bone. The
surface is 15 mm. wide at ‘the middle of the length, widening
forward, becoming narrower backward. The symphysis has
a width of 23 mm., both above and below.

So far as is to be seen, the plastral bones do not differ
from those of 7. serrifer. One coracoid is observed. The
length is 85 mm.; the width of the free end, 48 mm. The bone
is therefore both shorter land wider 'than that of TZ. latiremrs.

Some of the ways in which ‘this species differs from
T. latiremis have been mentioned; but the lower jaws are
especially different. In 7. /atiremis the grinding-surface is
narrower and it slopes downward and inward toward the inner
face.

T. serrifer differs in having the grinding-surface more con-
eee ceodhalys elkades “O° from front to back, of equal width from end to end, and

Lower jaw of type, with section the superior line of the symphysis equal to the width of the
at symphysis. X¢. grinding-surface, and to the lower line of the symphysis.

: In 7. stenopora the triturating surface of the lower jaw
slopes downward and inward to meet the inner face of the jaw. The upper line of the sym-
physis slopes downward and backward and is somewhat shorter than the lower line. “he
nasal opening is contracted. The length of the prefrontal suture is equal only to one-half

176 FOSSIL TURTLES OF NORTH AMERICA.

the interorbital space, whereas in 7. e/kader the same suture is equal to the whole width of the
interorbital space.

T. brachyrhina is a species with a blunter snout, a narrower lower jaw, and a much shorter
symphysis. The skull is narrower behind in proportion to the length.

T. procax also has a relatively narrower skull and the choane are placed further behind
the snout.

T. bauri, having been founded solely on portions of the shell, can not be compared with
any species based on the skull alone.

Toxochelys procax Hay.

Figs. 224-228.

Toxochelys procax, Hay, Bull. Amer. Mus. Nat. Hist., xx1, 1905, p. 181, figs. 13, 14.

The type of the present species is a large, but somewhat damaged, skull which belongs to
the American Museum of Natural History, New York. Its Siac is 234. It was obtained
from Mr. H. T. Martin, who collected it in the Niobrara deposits along the Smoky Hill River,
in Kansas, in 1gort. On the lower surface, the lateral wings of the pterygoids are broken away;
also the hinder extremity of one maxilla, and a small portion of the palatines. On the upper
surface, the greater part of the frontals and parietals is gone, as well as the whole of the jugals,

Fics. 224-228.—Toxochelys procax. Skull and lower jaw. 3.

224. Upper aspect of anterior portion of skull of type.

25. Skull of type, showing palatal surface.

26. Tip of lower jaw, with section (226a) along
symphysis. No. 234A.M.N.H.

7. Tip of lower jaw. No. 220A.M.N.H.

8. Dentary bones. No. 2050 Kansas Univ.

quadratojugals, and squamosals. On the lower jaw there are present a portion on each side
of the symphysis and the hinder end of one dentary.

The form of the skull (figs. 224, 225) is like that of T. latiremis, except that the outlines of
the maxilla, as seen from below, are nearly straight, until the snout is approacht; whereas
in T. latiremis the whole outline is convex. The skull is likewise more elongated than that of
T.latiremis. The interorbital space is 27 mm. wide; and the pterygoids, where narrowest, are

TOXOCHELYID. 177
22 mm. wide, taken together. In T. latrremis, No. 1497 of the American Museum, with skull
only two-thirds as long as the type of T. procax, the interorbital space is 20 mm. and the ptery-

-goids are 23 mm. T. procax is therefore characterized by a very narrow palate. :

The most important character for differentiating this species from T. latiremis is found in
the lower jaw. As shown by the symphyseal portions of the dentaries, the alveolar surface is very
broad, horizontal, and very slightly concave. In the midline this surface extends as far back-
ward as does the symphysis on the lower side of the jaw; whereas in 7. /atiremis the alveolar
surface extends backward little more than half as far as the lower face of the bone.

From the type of Cope’s T. serrifer this species is likewise distinguisht by the width of the
symphyseal portion of the alveolar surface. In 7. serrifer the surface extends backward nearly
as far as does the lower surface of the bone; but the width above is contained in the length of the
alveolar surface nearly 5 times, whereas, in 7. procax, it is contained only 2.5 or 3 times. The
inner face of the dentary is furthermore much deeper proportionally in 7. serrifer than in
T. procax. From T. brachyrhina this species differs, so far as known, in having a more pointed
head and a still narrower pterygoid region. The lower jaws of the two can not yet be com-
pared. From T. stenopora the present species differs in a much wider narial orifice and in the
character of the lower jaw, as well as in various other respects. 7. elkader hasa relatively
broader skull and choanz not so far removed from the snout. The lower jaws of the two species
appear to be greatly alike.

The length of the skull of the type of T. procax is 165 mm. from the tip of the snout to the
occipital condyle. The distance between the outer faces of the quadrates is 138 mm. Seen
from below the skull is wedge-shaped, and the snout rather pointed. The anterior narial
opening is of the usual form. Little can be said regarding the upper surface of the skull.

The alveolar surface of the upper jaw (fig. 225) is broad, and a strongly developt and very
rough ridge starts from the premaxilla and runs backward, first on the premaxilla, then on the
palatine. Between the anterior ends of these ridges there runs a deep median groove. The
palatine bones encroach more on the choanz than they do in J. /atiremis, so that these orifices
resemble somewhat those of Chelona. The alveolar surfaces are fully as broad at the anterior
ends of the choanz as they are posteriorly; whereas in J. latiremis they widen posteriorly.
There is a deep pit in the midline on the lower surface of the premaxilla, from which we may
infer that the lower jaw bore a sharp horny beak. The cutting-edges of the maxilla descend
but little below the level of the alveolar surfaces.

The tympanic cavity appears to have had about the same degree of development that we
find in Caretta.

At the symphysis (fig. 226) the alveolar, or masticatory surface, extends backward as far
as does the lower face of the bone, and each measures 32 mm. The alveolar surface is slightly
concave on each side of a low median ridge, which forks posteriorly. The symphysis has a
thickness of but 12 mm., which thinness may be due slightly to compression, but this is doubt-
ful. The groove on the inner face of the dentary continues to the symphysis. Fig. 227 repre-
sents another jaw fragment in the American Museum. Its number is 220.

No. 2050 of the Kansas University furnishes the united dentaries of this species (fg. 228),
but it has belonged to a smaller specimen than the type. A small portion has been broken from
the tip. The total length of one dentary is 80 mm. The width of the masticatory surface at
the symphysis is 24 mm., and it extends as far backward as the symphysis does on the lower
side of the jaw. The thickness of the bone at the hinder end of the symphysis is 9 mm., but
in life this may have been greater. The masticatory surface is broad and flat, but narrows
posteriorly. Both the inner and the outer borders are sharp, the latter overhanging the groove
along the inner face of the bone. The groove just referred to passes forward to the symphysis.

The writer has been enabled to examine a skull and lower jaw of this species, which belongs
to the University of Chicago. Its catalog number is 572. The exact locality in Kansas is
unknown. The skull is 117 mm. long from the snout to the condyle. The upper surface is
damaged to the same extent as in the type specimen. The masticatory surface of the lower
jaw extends backward 60 mm. from the tip of the jaw. Anteriorly it is somewhat concave,
but along the symphysis there is a rather prominent ridge. The thickness of the jaw at the
hinder end of the symphysis is 10 mm.

12

178 FOSSIL TURTLES OF NORTH AMERICA.

Toxochelys bauri Wieland.
Figs. 229-230.
Toxochelys baurt, WreLanp, Amer. Jour. Sci., XX, 1905, p. 325, plate x, text-figs. 1-8.

Up to the present time no better carapace of a Toxochelys has been recovered than that
forming the basis of Wieland’s Toxochelys baurz. This specimen forms No. 2823 of the Yale
University collection. It was found in the Niobrara deposits, near Monument Rocks, Gove
County, Kansas. It furnishes all the neurals, and the nuchal; large portions of all the eostals
of the right side, except the fifth; the proximal ends of all the costals of the left side; all the
peripherals of the right side, except the fifth to the eighth inclusive; all of those of the left side,
except the first slicer and the seventh, ninth, and eleventh. Of the plastron there is present
a considerable part of the right hyoplastron and hypoplastron. A number of Wieland’s figures
are here reproduced.

As to the distinctness of this species from all that have hitherto been described there may be
doubts, which it is too early to remove. Of two of the described species, T. brachyrhina and

Fic. 229.—T oxochelys baurt. Carapace of the type. X45.

C. p.1, Cc. p.2, ¢. p. 8, first, second and eighth costal plates; f, fontanels behind nuchal; n.1, 1.2, etc., the neural
bones; nu. p, nuchal plate; per. 10, the tenth peripheral; py, pygal bone; spy. 1, spy. 2, spy. 3, the
suprapygal bones. Or, spy. 1 may be the ninth neural; spy. 2 and spy. 3, first and second suprapygals.

T. procax, no portions of the shell are known; and 7. baur: may be the shell of one of these.
Of T. latiremis only small portions of the shell are known; but to judge from the figures of the
nuchal that have been publisht, the species is distinct from 7. baur:. The latter appears pretty
certainly to be distinct from 7. stenopora. Of the carapace of T. serrifer Cope there are known

only two peripherals, apparently the eighth and the ninth. ‘These appear to resemble greatly
the same peripherals of Wieland’s species. They belonged to an individual about half the
size of the latter. The eighth of Wieland’s type hada length of 80 mm. and a width, at the
notch, of 45 mm.; the ante a length of 75 mm. and a width of 45mm. The eighth of T. serrifer
is 41 mm. long and 25 mm. wide; "he ad 43 mm. long and 27 mm. wide. It will be seen that

TOXOCHELYID&. 179

the latter two peripherals are slightly wider proportionally than are those of JT. bauri. As
regards the thickness no definite statements can be made about either species, but both appear
to resemble the corresponding peripherals of Lytoloma.

The carapace of J. bauri has a length of about 530 mm.; its greatest width, when restored
to what is regarded as its original form, is about 400 mm. The species was therefore of consid-
erable size and the form was relatively narrow. In front the outline is concave along the nuchal;
while the rear is rounded. There are no excavations over the anterior limbs, such as are seen
in the modern Cheloniidz.

This carapace is composed of 8 pairs of costals, a nuchal, g neurals, apparently 3 suprapy-
gals, a pygal, and 11 pairs of peripherals. The first, second, and tenth peripherals had no
connection with the costals. The others received each the extremity of a rib in a pit. In all,
except the third and the eleventh, this pit is nearest the hinder end of the peripheral. There
are large costo-peripheral fontanels, which extended from the peripherals half-way to the
neurals. Besides these vacuities, there is a small one on each side at the common meeting-
place of the nuchal, the first costal, and the first neural. Similar vacuities are found in a few
of the Trionychide.

The accompanying table shows the dimensions of the neurals, taken from Wieland’s
description of the species. The forms may be determined from fig. 229.

Neural. Length. Width.

I 38 38
2 d4 37
3 44 40
4 46 44
5 34 45
6 50 40
7 40 38
8 25 35 Fic. 230.—Toxochelys bauri. Shell presenting left side. x}.
) i) 35

f, fontanels behind the nuchal; s,s, s, series of ossicles surmounting certain of the
neural bones. Reproduced from figure by Wieland.

It seems evident that an extra neural was intercalated in the series. This is shown by the
fact that, as the series runs, most of them are crowded somewhat out of their natural positions,
being nearly as much in contact with the costals in front of them as with those to which they
belong. This intercalation is shown in another way. There is a series of ossicles, 4 in number,
along the midline—ossicles which Wieland calls epineurals. The first forms a slight boss on
the first neural. The second lies across the suture between the third and the fourth neurals;
the third, across the suture between the fifth and the sixth neurals; the fourth rests on the
eighth and ninth neurals and the first suprapygal. This arrangement does not agree with
that appearing to exist in the other specimens of this genus which have furnisht the neurals.
Moreover, it does not correspond with the usual arrangement of the horny scutes of turtles. In
the specimen described by the writer in the American Naturalist (xxxu, 1898, p. 936) and in
the specimen here described on page 164,a sulcus passes behind each of the tubercles surmount-
ing the neurals. This sulcus in each case separates two of the
vertebral scutes. Now, almost without exception, the first sulcus
crosses the first neural, the second crosses the third neural, the
third traverses the fifth neural. The position of the fourth trans-
verse sulcus varies somewhat, but it is usually found on the eighth

Peripheral.) Length. Width.

I 60 25

5 5° + neural. Inthe present specimen the sulci must have crost on the
7 a - first, the fourth, the sixth neurals and the first suprapygal. It
5 65 28 seems evident that it is the third neural of the series that is an
° ie a8 intruder and disturber. Ina specimen of Colpochelys kempzr, in
8 80 45 the American Museum of Natural History, there are all together
9 75 45 13 neurals. The sulci cross on the first, the fourth, the eighth,
= pa FF and the twelfth neurals.

The nuchal bone has a width of 120 mm. along the free

180 FOSSIL TURTLES OF NORTH AMERICA.

border; a maximum width of 145 mm. Its fore-and-aft extent is 55 mm. ‘The table gives the
dimensions of the peripherals. “The width is taken at the notch of each where the sulcus crost
the free border.

On account of considerable crushing the thickness has not been given. We are informed
by Wieland that transverse sections are approximately as in the peripherals of Lytoloma
angusta ( I wieland1).

The pygal measures 65 mm. along the free border and 45 mm. along the midline.

The reader is referred to page 165 for remarks on the connection of the rib of the eighth
costal plate with the eleventh peripheral of this species.

Genus CYNOCERCUS Cope.

A genus based on caudal vertebra and a medapodial. Caudals proceelous and provided
with chevrons. The articular cup with a median perpendicular groove or incision.
Type: Cynocercus incitsus Cope.
This little-known genus is placed in the present family because of the possibility that it is
identical with Toxochelys.
Cynocercus incisus Cope.

Cynocercus tnctsus, Cope, Proc. Amer. Philos. Soc., x11, 1872, p. 308; Proc. Acad. Nat. Sci. Phila. 1872,
p. a Be Ann. Report U. S. Geol. Sury. Mont., ete., 1871 (1872), p. 335; Vert. Cret. Form.
West, 1875, pp. 96, 260, plate viii, figs. 3-5. —Wiuiston, iinet Geol. Surv. Kansas, tv, 1898,
p. 368, He 6.—Hay, Pubs. Field Colum. ‘Museum, Zool., 1, 1896, p. 106; Bibliog. and Cat. Foss.
Veet N. Avesl O02 aipin4 42,

Cynocercus incisus was based on two caudal vertebra and a metapodial. These were
found. by Cope in the yellow chalk, probably the Niobrara, near Butte Creek, south of Wallace,
Kansas. These bones are now in the American Museum of Natural History and have the
number 1582. It is not known whether the metapodial belongs to the fore or the hinder foot.

The vertebrae were fully described and figured by Cope as cited above. Williston repro-
duced a portion of the description and the figures of the vertebra. The reader is referred to
these authors. It may be here stated that the length of the centrum of each of these vertebra
is 27 mm., a fact showing that the animal must have been of considerable size. They did not
belong among the most anterior, for they possest chevrons. Cope stated correctly that they
differ Aram Figse of Chelydra in being proceelous. They differ further from those of the latter
genus in being more comprest and in having higher neural arches. Cope suggested a resem-
Bec to those of the Trionychoidea. Brom fhe latter they differ in possessing chevrons and
in having the transverse processes attacht to the centrum. ‘The vertebrz of the anterior half of
the tail of soft-shelled turtles have high neural arches; from these spring transverse processes.

What appears to distinguish fice caudals from those of any other known genus is the
presence of a sharp grooye, or incision, running perpendicularly down the middle of the articu-
lar cup. It has Been suggested by more dian one author that these vertebre are those of
some species of Toxoc helye: but this has not yet been proved.

Genus PORTHOCHELYS Williston.

Skull as broad as long. Nasal bones present. Lateral fontanels of the carapace obsolete.
All of the peripherals articulating closely with the costals. No carina along the middle of the
back and no tubercles. Plastron with small median and lateral fontanels.

Type: Porthochelys laticeps Williston.

Porthochelys laticeps Williston.

Plate 31, figs. 2, 3; text-figs. 231-234.

Porthochelys latice ps, ee Trans. Kansas Acad. Sci., xvit, B, 1901, p. 195, plates xvili—xxil.
Hay, Bull. Amer. Mus. Nat. Hist. xx1, 1905, p. 183.

The type of this fine species is the property of Kansas University and was collected in the
Niobrara beds, on the Saline River, in Trego County, Kansas. The remains comprize the
oreater portion of the skull, nearly the whole of the left side of the carapace, the whole of the

TOXOCHELYID&. I8I

plastron (except the epiplastra and the entoplastron) and the right humerus. From the portion
of the carapace present the whole has been restored, as seen in Professor Williston’s original
description. The figures presented in the present work have been redrawn, with slight modi-
fications, from Williston’s paper.

The skull (figs. 231, 232) is remarkable for its breadth and the massiveness of the jaws.
As shown bythe figures, the posterior breadth is maintained with slight diminution far forward,
so that the head appears very blunt, altho the snout is somewhat produced. The narial
opening is broader than high, and its upper boundary is furnisht mostly by a pair of small
nasals. The orbits are rather large and directed rather strongly upward. The interorbital
space is 19 mm. wide. The bones covering the temporal region are so much damaged that the

Fics. 231 AND 232.—Porthochelys laticeps. Skull of type. x3.

231. Upper surface. 232. Palatal surface.

extent of the roof can not be determined; but it was probably as extensive as in Toxochelys.
The bones of the upper surface of the skull are much roughened, as in Chelydra. :

The palatal surface of the skull is shown in fig. 232. The cutting-edge of the maxilla is
deeper than in Toxochelys latiremis, and its depth increases toward the jugal bone. The palatal
surface of the bone, 10 mm. wide in front, increases to 20 mm. at the hinder end. The masti-
catory surface extends over on the palatine and is markt internally by a rough ridge. “Trans-
versely the surface is slightly concave. The choane are not encroached on by plates from the
vomer and palatines, as they are in the Chelontida, but lie well forward in a shallow fossa.
They are separated by the vomer, which is wide anteriorly, narrow between the choanz, and
develops a sharp ridge on its palatal surface. As in Chelydra, each pterygoid developt a strong
lateral process, against which the inner surface of the
dentary workt. The width of the pterygoids, where
narrowest, is 30 mm. The quadrates are notcht behind
for the passage of the columella, as in 7 oxochelys.

Of the mandibles only the united dentaries are pres-
ent (fig. 233). They are very heavy and strong bones.
The masticatory surface is somewhat concave both trans-
versely and longitudinally, and is bounded internally
along the anterior half by a rough ridge. At the sym-
physis the two ridges unite and run to the front of the
jaw. This masticatory surface is, in front, only about
half as wide as is the symphysis itself; but it widens
backward and overhangs the inner lower border of the
jaw. The coronoid process is considerably elevated.

The carapace (plate 31, fig. 2; text-fig. 234) is now very flat. How deprest it was during
life it is impossible now to say; but it probably had no great elevation. It is nearly circular,

Fic. 233.—Porthochelys laticeps. Den-
tary bones of type. 4. Redrawn
from Williston’s figure. Shows grind-

ing-surfaces.

182 FOSSIL TURTLES OF NORTH AMERICA.

the width being 785 mm., the length only 730 mm. The border appears to have been slightly
excavated in front, elsewhere somewhat repand. The costal plates are so extensively ossified
that there now remain only insignificant fontanels at their outer ends. The greater portion of
the nuchal bone is missing. The peripherals are eleven in number on each side. They are
rather narrow in front but their width increases posteriorly, and they become quite thick.
The sixth from the front is equal in width to one-eighth of the width of the carapace; the eighth
is a little more than one-sixth of the width of the carapace.

Of the neurals the fifth and sixth are wholly wanting, while the fourth and seventh are
represented each by only a small portion. Those present are narrow, about 30 mm.wide. The

= — second, third, and fourth have their anterior outer angles
cut off by contact with the costals in advance. ‘The
neurals are smooth, and without trace of the tubercles
which are so conspicuous in J oxochelys. There are two
suprapygals, each forming a symmetrical trapezoid, and
these are placed base to base.

Dermal scutes were present, and are indicated by very
distinctly markt sulci. The vertebrals are narrow, the
third and fourth being about one-seventh as wide as the
shell. The first is slightly wider; the fifth has a width
equal to one-fourth the width of the shell. The mar-
ginal scutes lie almost wholly on the peripheral bones.

The plastron (plate 31, fig. 3) resembles greatly that
of Toxochelys. There were small central and lateral
fontanels. Probably the right and left halves of the
plastron approacht each other more closely than is
shown in the figure. The thickness of the hyoplastron
and hypoplastron where they join is from 10 to 12 mm.
They are thin and serrated along the median border.

The right humerus accompanies the remains, but the
ulnar process is broken away. The bone is flattened,
mostly as a result of compression during burial. It
appears to have resembled closely the corresponding bone
of Toxochelys; but the radial process has been directed

Fic. 234.—Porthochelys laticeps. Cara-
pace of type. 3. Restored por-

fone aicared by dotted lines: more strongly toward the ulnar side. The total length of

the bone was 140 mm. The position and extent of the
epicondylar groove and of the condyles for the radius and ulna seem to have been the same as
in Toxochelys. Two cervical vertebra,a small portion of the scapula,and a claw are mentioned
by W illiston as furnishing no important differences when compared with those of Toxochelys.
In general appearance this turtle differs greatly from Toxochelys. The head is of heavier
construction and of blunter form; there are nasals; the carapace is circular, instead of
elongated and pointed behind; it is more extensively ossified; and there is no carina along the
middle of the back. Otherwise Porthochelys agrees with Toxochelys. As already remarkt,
the presence of nasals is regarded as being of no more than generic value.

Porthochelys browni Hay.
Figs. 235-237-
Porthochelys browni, Hay, Bull. Amer. Mus. Nat. Hist. xx1, 1905, p. 183, figs. 15, 16.

The type of this species was collected during the summer of 1903, by Mr. Barnum Brown
of the American Museum of Natural History, in deposits shown by their invertebrate fossils
to belong to the Pierre formation. The locality is 20 miles southeast of Edgemont, South
Dakota. The catalog number of the specimen is 6080.

The specimen presents the skull and the lower jaw nearly complete, some pelvic bones,
one humerus, one scapula, a femur, and some other limb bones. Unfortunately most of the
bones are crusht nearly flat and were covered with a layer of gypsum. Altho the skull is consid-
erably crusht, the most essential elements of its construction may be determined.

}

TOXOCHELYID. 183

The skull is broad and it was probably originally considerably deprest, but to what extent
the present flatness is due to pressure can not be determined. The outlines as seen from above
(fig. 235) are greatly like those of Porthochelys laticeps, but the skull of the present species
is longer than broad. The sides of the skull converge slowly to the front of the orbits, where the
width is still 100 mm., then rapidly approach the tip of the snout. The outline is such that the
snout appears somewhat produced. The occipital condyle is broken away, but from its esti-
mated position to the end of the snout is 160 mm.; from the end of the supraoccipital spine to
the snout, 190 mm. The breadth from the outside of one quadrate to that of the other is 142
mm. The bones of the upper surface of the skull are smooth, whereas those of P. latice ps are
ridged and grooved. The temporal region is rooft over not quite as far backward as the
hinder borders of the exoccipitals and paroccipitals, so that the latter bones are seen from above.
Hence, the roof is not so extensive as in Chelonia mydas, but about as complete as in Caretta.

Fic. 235.—Porthochelys brownt. Skull of type, upper aspect. 4. No. 6080 A. M.N. H.
fr, frontal; ju, jugal; mx, maxilla; pa, parietal; pof, postfrontal; prf, prefrontal; sg, squamosal.

The eyes of this turtle were evidently directed strongly upward as well as outward. The
distance from the middle of the lower part of the rim of one orbit to that of the other is go mm.
The width of the interorbital space is 30 mm. If now the middle of the interorbital space
stood 50 mm. above the roof of the mouth the plane of the orbits would stand at an angle of
45° with the horizontal. It is not probable that the elevation of the skull was greater than that
supposed. The longitudinal diameter of the orbit is 50 mm. The transverse diameter of one
is now 33 mm., of the other 30 mm. If the elevation of the skull was originally 50 mm. above
the roof of the mouth the transverse diameter of the orbit must have been about 43 mm. It
is not likely to have been more. Hence, we seem to be justified in believing that the eyes were
directed strongly upward.

It is evident that the nasal opening was higher than wide. Its present width is 19 mm., its
height 21 mm. The distance from the orbit to the hinder border of the temporal roof is 53 mm.

The anterior borders of the choanz are placed 43 mm. behind the tip of the snout (fig. 236).
The palatines appear to have joined the vomer, as in Toxochelys. The crushing-surtaces of
the upper jaws have a width of about 27 mm. They are concave from the cutting-edge of the
jaw to the palatines. The width of the combined pterygoids, where narrowest, is 39 mm.

184 FOSSIL TURTLES OF NORTH AMERICA.

The lower jaw (fg. 237) is nearly complete. The crushing-surface has a width of 18 mm.
and is convex transversely. The cutting-edge is acute and directed outward, possibly due
partly to distortion. The tip of the jaw appears to have been somewhat upturned as a beak,
and there is a corresponding pit in the upper jaw just behind the premaxilla. The symphysis
has a length of 35 mm.

The humerus is crusht very flat and the ulnar process is broken off. The length of the bone,
measured from the proximal surface of the head to the distal end, is 156 mm. The impression

Fics. 236 AND 237.—Porthochel ys brownt.
Skull and lower jaw of type. 3.
236. Palatal surface. mx, maxilla; pal, palatine;
pt, pterygoid; qu, quadrate; vom, vomer.
237. Lower jaw. ang, angular; art, articular;
dart, dermarticular; den, dentary; sur,
supraangular.
of nearly the whole head appears on the upper side of the flattened bone; hence it is evident
that the head was directed upward when the bone was horizontal and not as it is in the
Cheloniide. The radial process was connected with the head and there existed a broad exca-
vation, or fossa, between this process and the ulnar process. In short, the humerus appears
to have had practically the form of that of Chelydra.
The distal end of the femur is missing, but the bone was at least nearly as long as the
humerus. It was, however, a slenderer bone.
The ilium resembles closely that of Toxochelys.

Family DESMATOCHELYID£ Williston.

Skull with temporal region rooft over as far backward as the occipital condyle. Large
nasal bones present. Choanz placed well forward, not underfloored by the vomer, maxille,
and palatines. Small posterior palatine foramina present. Humerus indicating a paddle-like
fore limb. Plastron loosely joined to the carapace.

The type of this family is the genus Desmatochelys, but the genera Atlantochelys and
Neptunochelys are provisionally included. The two latter are known only from humeri.
These are not greatly different from the same bones in the Cheloniide.

Genus DESMATOCHELYS Williston.

Desmatochelys, WiLLIston, Kansas Univ. Quart., m1, 1894, p. 5-
Desmochelys, BoULENGER, Zool. Record, Reptiles, 1895, p. 29-

‘The generic characters are not yet to be distinguisht from those of the family.
The type of the genus is Desmatochelys low: Williston.

DESMATOCHELYID. 185

This genus is a most interesting one, inasmuch as it shows evident relationships with the
Cheloniidz, and at the same time presents characters which must be regarded as more primitive
than those of the latter family. Among these characters is the possession of well-developt
nasal bones. ‘The choanz too have their primitive position just behind the premaxilla and are
separated by the body of the vomer. In the Cheloniide the latter bone sends downward a
perpendicular plate, the lower border of which expands laterally and joins horizontal plates
of the maxilla and of the palatines, forming a floor beneath the narial passages and pushing
the choane further backward. The possession of small posterior palatine foramina shows a
closer connection with Amphichelydian stock than exists in the Cheloniida, which have lost
these foramina.

Williston thinks that the cervical vertebra indicate pleurodiran characters. The posses-
sion of strongly developt transverse processes is to be regarded as an inheritance rather from
the Amphichelydia than from the Pleurodira. The articular ends of the cervical vertebre
show decided affinities with the Cryptodira. An intervertebral articulation which is 26 mm.
wide and only 15 mm. high, belonging to a centrum only 26 mm. long, would not lend itself
readily to flexure sidewise, while it would permit easy flexure in a perpendicular plane.

The Desmatochelyidz are to be arranged close to the Cheloniida; but their many prim-
itive characters demand that they be kept in a distinct family. For those who are seeking a
Cretaceous ancestor for the modern sea-turtles, Desmatochelys presents itself as a more eligible
form than any of the Cretaceous Thalassemydide.

Fics. 238 AND 239.—Desmatochelys lowt. Skull of type. 4.

238. Upper surface. 239. Seen from below.

Desmatochelys lowi Williston.
Figs. 238-243.
Desmatochelys lowii, Witiiston, Kansas Univ. Quart., m1, 1894, p. 5; Univ. of Kansas Geol. Sury.
Iv, 1898, p. 353, plates Ixxiii-Ixxvili—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 443-

The original and only known materials belonging to the present species are the property
of the University of Kansas. They consist of the skull, finely preserved, but lacking the hinder
part of the base; 3 cervical, the sacral, and some caudal vertebre; the pectoral girdle, the
humerus, radius, and some metacarpal bones; most of the pelvic bones and an incomplete
femur; some fragments of the carapace and some of the plastron. The animal was appa rently
preserved in fine condition, but was damaged in collecting. The remains were found in Benton

186 FOSSIL TURTLES OF NORTH AMERICA.

deposits, near Fairbury, Nebraska. An extended description of the species, with figures, is
given by Williston, as cited above. A number of his drawings have been reproduced in the
present work.

This turtle was evidently a large one. The skull (figs. 238, 239) is uncrusht, but the hinder
portion of the base is damaged. The total length from the snout to the end of the supraoc-
cipital spine is 205 mm.; the width thru the quadrates is 145 mm. The skull is remarkable
for the length of the posterior lateral, or squamosal, processes. These lack but little of extend-
ing backward as far as the supraoccipital process; while the latter has about its usual length.
The parietals are unusually narrow. Williston informs us that these bones join the squamosals.
The frontals and the prefrontals together occupy the area occupied in Chelonia mydas by the
frontals. In front of the prefrontals come the large nasals, bones rarely found in Cryptodira.
These nasals are about 13 mm. long and each is about 1g mm. wide. The antero-posterior

Fics. 240-243.—Desmatochelys lowt. Portions of the type.

240. Humerus. 242. Fragments of peripheral bones.

241. Pelvic bones. #/, illum; isch, ischiuin; pub, pubis. 243. Fragments of plastron and peripheral bones.
diameter of the nasal opening is 24 mm.; the transverse diameter, 18 mm. It looks strongly
upward. The orbits have an antero-posterior diameter of 60 mm. The interorbital space is
58 mm. wide.

The palate (fig. 239) is remarkable on several accounts. The choane are considerably
further forward than they are in the Cheloniide; but what is more important, there is no Hoor
beneath them formed by the bones bounding them. Each is at the anterior end of a longitudinal
concavity, whose depth diminishes backward. The transverse sutures between the palatines
and the pterygoids are relatively much further backward than they are in Chelonia mydas.
The pterygoid processes are therefore more posterior than usual. The possession of posterior
palatine foramina is another feature distinguishing this species from any of the modern sea-
turtles. They are small, and may be regarded as vestigial. Behind the pterygoid processes
the palate narrows to a width of about 22 mm. In front of the processes named there 1s another
slight constriction of the palate. The longitudinal median sutures are not discernible, and it
is not certain that the palatines joined in the midline.

DESMATOCHELYID&. 187
The lower jaw is firmly cemented to the skull, hence no examination can be made of the
triturating surfaces; they were, however, undoubtedly narrow. The symphysis is 43 mm. long.
Williston has described and figured one cervical vertebra. It is 26 mm. long, a fact indi-
cating that the neck was short. The articular surface is 26 mm. from side to side and 15 mm.
vertically. Near the hinder end of the centrum there is, on each side, a stout transverse process.
The sacral and several caudal vertebre are preserved and have been described by Williston.
The caudals are all small and proccelous. :

The length of the scapula, measured from the tip to the lower border of the proscapular
process, is 158 mm. The process just named is 82 mm. long. The coracoid has a length of
100 mm. and a width, at the free end, of 35 mm. The shaft is much constricted in the middle
of the length.

The humerus (fig. 240) is a large flat bone, which, by its whole structure, shows that it
belonged to a turtle which dared the open seas. The tength, from the proximal surface of the
head to the distal end, is 202 mm.; while the extreme length is 260 mm. The last dimension
indicates the great height of the ulnar process. The width across the head and the ulnar
process is about 110 mm. ‘The shaft, where narrowest, has a diameter of 80 mm. The distal
end is rounded and has a width of 80 mm. The radial process is large and extends downward
on the shaft about 90 mm. below the upper surface of the head.

Williston figures a radius, a supposed ulna, and various bones belonging to the hand.
Fig. 241, from Williston, represents the ilium, ischium, and pubis of the right side. Williston
figures also an incomplete femur. Evidently it was a feebler bone than the humerus.

But little of the carapace was secured. The costal plates have a thickness of only 2 or 3 mm.
The rib-heads are stout. One of the hinder costals has a width, near the proximal end, of
40mm. The neural corresponding to it is 32 mm. wide. No sulci have been observed on any
of the bones of the carapace.

Fig. 242, from Williston, represents the pygal and the adjoining right peripheral. The
pygal measures antero-posteriorly at the midline, 61 mm.; and from side to side, 97 mm.
Its thickness is 6 mm.

Fig. 243 represents a fragment of one of the plastral bones and one of the lateral peripherals.
Evidently, the plastral bones were loosely connected with the carapace, as in the Cheloniide.
The peripheral has a length of 130 mm., and a width of about 35 mm., and a thickness of 6 mm.
Other peripherals, believed to be more anterior in position, are thicker and longer.

Not enough of the plastron was secured to furnish exact knowledge regarding its structure.

Genus NEPTUNOCHELYS Wieland.

A genus based wholly on a humerus of a turtle which was adapted for lite on the sea.
Humerus flattened; the head, the ulnar, and the radial processes in the plane of flattening, or
nearly so. Radial process not so far removed from the head as in the Protostegida. Humerus
resembling that of the Cheloniida, still more that of Desmatochelys, differing from the latter
in having the head more nearly in the axis of the bone and the ulnar process nearly parallel
with the axis.

Type: Neptunochelys tuberosa (Cope).

Neptunochelys tuberosa (Cope).
Fig. 244.
?Holcodus acutidens, Leiwy, Smithson. Contrib. Knowl., x1v, art. vi, 1865, pp. 42, 118, plate viii, figs. 1, 2.
Protostega tuberosa, Cope, Fifth Ann. Report U.S. Geol. Surv., Montana, etc., 1871 (1872), p-3345 Vert.
Cret. Form. West, 1875, p. 257-
Atlantochelys tuberosus, Lewy, Ext. Vert. Fauna West. Terrs., 1872, p. 342.
Neptunochelys tuberosa, WIELAND, Amer. Jour. Sci. (4), 1X, 1900, pp. 417, 418.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 440.

No part of this great sea-turtle is known except the humerus. This was found many
years ago by Dr. Spillman, in Upper Cretaceous deposits, at Columbus, Mississippi. Having
been found associated with the bones of a mosasauroid reptile and described before the limbs of
the Mosasauria were known, it was believed to be possibly the humerus of Holcodus acutidens.

188 FOSSIL TURTLES OF NORTH AMERICA.

Cope was the first to refer the bone to the turtles, and he placed it in his genus Protostega.
At a little later time Leidy referred it to Atlantochelys. In 1889 Baur correctly concluded
that it could belong to neither Protostega nor to . Atlantochelys, but he did not name the genus.
Thistvassesenvedde Wiclandicotonn 1900.

The total length of the humerus (fig. 244) 1s 10 inches, or 253 mm. ‘The shaft, where
narrowest, is 48 mm. wide and 28 mm. thick. The distance from the extremity of the ulnar
process to that of the radial process was estimated to be 152 mm. The breadth of the distal
end is 93 mm.; the thickness, 30 mm. The form of the bone is shown by the figure, copied
from Leidy.

Genus ATLANTOCHELYS Agassiz.

A genus based on the proximal end of a humerus of a sea-turtle. The head and the ulnar
and radial processes in approximately the same plane. Radial process hardly separated from
the head. Ulnar process directed nearly parallel with axis of bone. Shaft unusually slender.

Type: Atlantochelys mortont Agassiz.

Fic. 244.—Neptunochelys tuberosa. Fic. 245.—Atlantochelys mortont. Portion of humerus
Humerus forming the type. »}. forming the type. +. After Leidy.

Atlantochelys mortoni Agassiz.
Fig. 245.

Atlantochelys mortont, AGassiz, Proc. Acad. Nat. Sci. Phila. 1849, p. 169 (no description); in Lripy,
Smithson. Contrib. Knowl., xiv, art. vi, 1865, p. 43.—Leipy, Ext. Vert. Fauna West. Terrs.,
1872, p. 342.—WIELAND, Ree Jour. Sci. (4), 1900, p. 419, figs. 14-16.—Hay, Amer. Nafuralise
XXXII, 1898, p- 930; Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 440.

Misacaurus mitchell, Leipy, Smithson. Contrib. Knowl., xiv, art. vi, 1865, 43, 117, plate vil, figs. 3-5

Protostega neptunta, Cork, Fifth Ann. Report U. 5. Geol. Surv. Terrs., 1871 (1872), p. 334; Proc. Amer.
Philos. Soc., x11, 1872, p. 433; Vert. Cret. Form. West, 1875, p. 257.

Like Neptunochelys tuberosa, this species is based on a humerus which was derived from
the Upper Cretaceous formation. The exact locality and level were not reported, but we
know that the fossil was found in one of the beds of Cretaceous greensand in Burlington
County, New Jersey.

Of this humerus (fig. 245) there was secured only the proximal half or less. This fragment
had a length of about 280 mm. The shaft was extremely slender, being 73 mm. mide and
60 mm. thick. The ulnar process rises above the head about 75mm. The radial process is

DESMATOCHELYID&. 18g

hardly separated from the head. The ulnar process is nearly parallel with the long axis of the
bone. The head is farther removed from the axis than in Ne eptunochelys. In these two
respects Atlantochelys resembles Desmatochelys; but it differs from the latter in having a
slender shaft. This humerus must have been fully as long as that of Archelon, but it was of
very different form. A very large turtle is indicated.

Family PROTOSTEGIDZ Cope.

Marine turtles with the fore limbs converted into flippers resembling those of the Che-
loniidz. Carapace greatly reduced, the disk extending not one-half the distance toward the
distal ends of the ribs. Peripherals present. Plastron loosely connected with the carapace
and with a large median fontanel. Entoplastron T-shaped, with the lateral wings elongated
and distally expanded. Epiplastra not certainly known. Xiphiplastra short and bent. Skull
large, temporal region broadly rooft over. Region i in front of the orbits elongated. Jaws with
large crushing-surfaces. Choanz far fovwacd: not underfloored by the surrounding bones.

Genera: Protostega, Archelon, and probably Protosphargis, all of the Upper Citaccous:

The writer is strongly of the opinion that the genera Protoste gaand Archelon ought to be
kept apart from the syodein sea-turtles as a dance family. Vat both the Protostegide

ee

Fic. 246.—Protostega potens. Entoplastron and xiphiplastron of type.» 5.

ent, entoplastron; xiph, xiphiplastron.

and the Cheloniide had their origin from a common ancestor, which was a sea-going turtle,
need not be denied; but the two branches have been separated so long, and each has developt
so many peculiarities, that it seems unwise to force them into the same family. That the
Cheloniide have been derived directly from the Protostegida it 1s impossible to believe. The
latter family was in several respects more highly difereneated than the living sea-turtles.
The greatly reduced carapace, the peculiar entoplastron, the abbreviated xiphiplastra, the
large preorbital region, and the strongly modified humeri are examples of these differentiations.

For the discussion of the relationships of this family to the Chelonidz and to the Der-
mochelyidz, the reader is referred to the papers of Baur, Case, Furbringer, Van Bemmelen,
Boulenger, Lydekker, Dollo, Wieland, and Hay.

The bone which is here regarded as the entoplastron (fig. 246, ent) was, in Protostega,
originally described by the present writer, on the advice of Dr. Baur, as the nuchal. ‘This
view was adopted by Case and afterwards by Wieland.* The latter, in describing Archelon,
originally held the bone to be the coalesct epiplastra and entoplastron, called by him the
paraplastron. A re-examination of the subject, in the light of all the known materials, has
led the present writer to change his opinion. The reasons for regarding this bone as the
entoplastron are the following:

(1) The bone has never been found in direct connection with peripheral bones.

(2) It has been found four times closely associated with plastral bones, and in two o1
three of these cases it was in its apparently ‘natural position with relation to the hyop ylastra.

5f

*Since this was sent to the press Dr. Wieland has publisht a paper (Ann. Carnegie Mus., iv, 1906,
p. 8) in which he accepts the view that the bone is the entoplastron.

Igo FOSSIL TURTLES OF NORTH AMERICA.

In the first instance it accompanied only plastral bones that were described by the writer.
Then Case found it with its lateral wings resting on the hyoplastra. He supposed that it
had fallen from the carapace to its position, a not unreasonable conclusion. After this
Wieland informed us that he had found it twice in place, resting directly upon the anterior
portions of the hyoplastra and beneath numerous other skeletal parts.

(3) Wieland described a bone as the nuchal which can hardly be anything else.

(4) In the specimen described here as P. potens the bone in question again occurs. On
the visceral surface, near the anterior border, there is, on each side, a deep and broad groove
(fig. 246) that must have received another bone. This groove reaches nearly to the midline.
It is quite improbable that the first peripheral had a long process that filled this groove. On
the other hand, the epiplastron might be expected to lie on the upper side of the entoplastron.
The structure of this entoplastron is not far distant from that of Chelydra. In this genus
there is a median backwardly directed process from the anterior end of which, on each side,
there projects a lateral slender process. Were these lateral processes to become directed
at right angles with the median process and to become broader, we would have just such an
entoplastron as we have in Protostega. In Chelydra, Chelonia, and Caretta we find that
the epiplastra overlap the lateral processes of the entoplastron, just as they seem to have
done in Archelon and Protostega.

As regards the superposition of the T-shaped bone on the hyoplastra of Protostega there is
this to be said. The entoplastron appears naturally to join the hyoplastra edge to edge. Often,
perhaps usually, the hyoplastra push themselves slightly over the entoplastron anteriorly.
It is, however, certain that the posterior spine-like prolongation falls above the hyoplastra.
If the entoplastron expanded laterally without suturally joining the hyoplastra, there appears
to be no reason why it should not rather pass above than below the latter bones. The epiplastra
are missing in all the specimens in which the T-shaped bone accompanies plastral bones.
These were, however, probably thin, light bones and could easily be removed from their
natural position. Their outer ends, doubtless, were in ligamentous union with the anterior
borders of the hyoplastra.

In Wieland’s paper just referred to he describes a bone of Archelon which he regards
as the left epiplastron. He holds that this bone was overlapt by the outer end of the T-
shaped entoplastron, that certain grooves in the bone were filled by digitations or ridges of
the entoplastron, and that the thickened anterior end of the bone projected outward and
forward as in the trionychids. The present writer finds it impossible to place the bone in
this position. It seems more probable that the bone is the right epiplastron, that the thinner
end narrowed to a point and was directed inward on the upper surface of the wing of the
entoplastron, while the thickened end was directed backward along the border of the hyo-
plastron.

Genus PROTOSTEGA Cope.

Premaxillary beak less developt than in Archelon. Maxilla with a rather broad grinding-
surface, which extends backward to behind front of orbit. Lower jaw with the rami early
co-ossified. Entoplastron T-shaped, with the middle third of the anterior border concave
from side to side, the distal ends convex. Radial process of humerus large.

Type: Protostega gigas Cope.

Protostega gigas Cope.
Figs. 247-253.

Protostega gigas, Cope, Proc. Amer. Philos. Soc., xu, 1871, pp. 175, 452; Fifth Ann. Report U.S. Geol.
Surv. Montana, etc., 1871 (1872), pp. 323, 335; Vert. Cret. Form. West, 1875, pp. 48, 102, 256,
plate ix, figs. 1-7; plates x-xi; Amer. Naturalist, x11, 1878, p. 137.—Hay, Pubs. Field Columb.
Mus., Zool., 1, 1895, p. 57, plate iv, v; Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 440.—Casg, Jour.
Morphology, xiv, 1897, p. 21, pee —vi.—WIELAND, Amer. Jour. Sci. (4), IX, 1900, pp. 416, 420,
figs. 8,19; Mem. Carnegie Mus., 11, 1906, p. 279, plates xxxi—xxxiil, text-fg. 1.—WILLIsToN, Amer.
Jour. Sei, (4), XIII, 1902, p. 276, fig. Ondo’ Science, XIX, 1904, p. 35.—STERNBERG, “Tans
Kansas Acad. Sci., XIX, 1905, p. 123.

Atlantochelys gigas, Dana, Manual Geol., ed. 11, 1875, p. 466.

PROTOSTEGID. Igl

The specimen of this species which Cope originally described was found by him in 1871
in Niobrara deposits, near Butte Creek, south of Wallace, Kansas. This is now in the Ammen
can Museum of Natural History and has the number 1503. At the time of its discovery the
bones were much distorted and comprest; and most of them were much fractured in collecting
them. Cope states that the portions described by him were reconstructed out of over Soo
pieces. One of the large bony plates, described as overlying the ribs, had been broken into
108 pieces. Most of the bones are yet in the condition in which Cope left them; the large
plates are, to a great extent, again broken up.

As stated by Cope, the remains preserved include many parts of the skull; 5 vertebra,
more or less incomplete; the scapular arches of both sides, with the coracoids; both humeri
perfect, and some phalanges; 10 ribs; 1 doubtful neural bone; 10 peripherals; parts of 4
large plates, described as overlying the ribs; and some undetermined bones.

From his study of his materials Cope arrived at the conclusion that Protostega was a
large marine-turtle closely allied to Dermochelys, and had a total length of about 12 feet.

The first author who added to the knowledge of the species was Dr. George Baur, who
(Zool. Anzeiger, 1x, 1886, p. 688), regarding the genus as Atlantochelys, stated that the plates
assigned by Cope to the dorsal region were really portions of the plastron. This determination
was undoubtedly made from the bones collected by Cope. Hay, as cited, gave, in 1897, a

Cope’s determinations of the bones within parentheses. ju (pt), jugal, Cope’s pterygoid; mx (por), maxilla,
called by Cope the postorbital; prf, prefrontal; pof, postfrontal; guj (col), quadratojugal, Cope’s columella;
sq (mx), squamosal, called by Cope maxilla.
description, with figures, of the hyoplastra and hypoplastra of a specimen that had been
collected for him near Butte Creek, Kansas. Case (1897, as cited) described portions of the
skull and a more complete plastron than had previously been secured, materials now in the
University of Kansas; and made correction of Hay’s restoration of the xiphiplastra. More
recently Wieland has described excellent materials which belong to the Carnegie Museum,
at Pittsburg.

Cope had considerable portions of the skull and most of these he figured. The writer
has studied these bones and has found that in most cases Cope’s determinations were incorrect.
Baur had also examined these cranial bones and accepted Cope’s determinations (Amer.
Naturalist, xxiv, 1890, p. 532).

Fig. 247 represents these bones, each having its name indicated. Cope’s determinations
are indicated in parentheses.

The first of these elements that will be noticed is that which Cope called the postfrontal
(Vert. Cret. Form. West, plate xi, figs. 32, 34). In his description he called this the left post-
frontal; but, since the straight margin was regarded as the lower, the bone would have to be
placed on the right side. In reality, the bone is the left maxilla (fig. 247, 1x), joined to the
prefrontal. The straight border is the cutting-border of the maxilla; and the crusht tritu-
rating surface is seen, in Cope’s figure, pushed below this border. Evidently the cutting

1g2 FOSSIL TURTLES OF NORTH AMERICA.

edge did not extend much below the triturating surface during life. We can not now tell
how wide the triturating surface was originally. At its anterior end is seen a broad articular
surface for the vomer. Cope thought that this surface was for the “‘zygomatic” bone. Cope
did not recognize the suture between the lower and the upper portions of the mass of bone
figured by him. The suture is not distinct, but the radiations on the surfaces of the bones
show distinctly where the suture is located. The upper bone is the prefrontal, prj. On the
inner side of its upper border is a broad articular surface for union partly with its fellow bone,
partly with the frontal. Posteriorly the prefrontal articulated with the postfrontal, pops this
excluding the frontal from the orbit. In Cope’s fig. 3a 1s seen a bridge of bone joining the
prefrontal with the maxilla. The upper part of his bridge is undoubtedly the descending
plate of the prefrontal which joined the vomer; the lower portion of the bridge is quite certainly
a portion of the palatine. The foramen between the bridge and the maxilla is the nasopalatine.
Cope did not explain the presence of such a bridge af bone on the supposed postfrontal.

The bones described by Cope as the pterygoid and the columellar, and accepted as such
by Baur, are the jugal, ju, and the quadratojugal, quj. Those of the right side are shown in
Cope’ s fig. 5, plate x; those of the left side in his fig. 1, plate x1. What Cope regarded as the
posterior send of the larger bone is the anterior. The more concave border formed a part of
the rim of the orbit. The form of both these bones is almost exactly as in Archelon ischyros,
as figured by Wieland. As in that species, the jugal extended backward to the quadrate.
The hinder border of the quadratojugal is concave to form the anterior boundary of the
tympanic cavity. | It is to be noted that the conspicuous oval mark shown in Cope’s fig. 1
plate xi, is nothing but a little matrix overlaid by a thin layer of bone, probably of some fist
In Cope’s fig. 5, plate x, the quadratojugal is in nearly i its natural position. It is there recog-
nized as the zygomatic (quadratojugal), but it is the fellow of the bone which on the other
side is determined as the ptery goid. The other bone, the jugal, has been turned end about,
to agree with Cope’s idea of its proper position.

Both quadrate bones are present; and that of the right side is represented in Cope’s
fig. 5, plate x. Both are badly crusht, but that of the nght side shows the condyle less distorted.
Just above the condyle, on the outside of the bone, is a scar where the quadratojugal articu-
lated with the quadrate. On the inner border of the latter bone is another articular surface for
the hinder end of the ptery goid.

Cope’s fig. 2, plate xi, represents a bone which he identifies doubtfully with the anterior end
of the ptery goid. It is really nearly the whole of the pterygoid, a small portion of the anterior
end alone being broken away. Cope’s figure represents the bone as seen from below. At the
hinder end of the bone, on its upper surface, is a large rough surface for articulation with the
quadrate. From this extends forward a ridge which may have joined anteriorly either the
columellar bone of the lower end or the descending process of the parietal. At the hinder end
and below, and represented in Cope’s figure, is a rough excavation for the border of the basioc-
cipital. The mesial half of the middle third of the lower surface is occupied by a rough surface
which was overlapt by the basisphenoid. The relations here appear to have been muh as in
Dermochelys. The pterygoids are relatively narrow, outer borders thickened and obtuse.

The bone identified by Cope as the maxilla (fig. 247, sq) is the squamosal. Cope represents
that of the left side. He regarded the curved order above the elongated process as the border
of the orbit and states that the width of the bone below the orbit was 35 mm. Fortunately, the
corresponding bone of the other side is present; and this shows that that curved border is the
result of damage to the bone. The upper edge of the bone should extend above the lower
border at least go mm. What Cope took to be the cutting-edge of the maxilla is the free,
sharp, and smooth hinder border of the squamosal, ascending toward the parietal. What
Cope regards as the premaxillary border is a free border descending to the quadrate. The wing
of bone seen extending upward in Cope’s figures is the horizontal plate of the squamosal w hich
OV erlapt the upper end of the quadrate and the outer end of the paroccipital. Pressure has
caused it to lie nearly parallel with the body of the bone. On the outer border, that opposite
the long, straight border, is seen a portion of the tympanic cavity. Wieland’s figure of the skull
of this species shows that a process of the squamosal reaches the outer border of the parietal.

The true postfrontal bone (fig. 247, pof) is present, but it was not figured by Cope and
appears not to have been mentioned. It has on its lower border a process which articulates

PROTOSTEGIDZ. 193

with the upper border of the jugal. The hinder end of the bone is broken away, so that the
whole length can not be determined. The breadth of the bone, taken just Behind the process
mentioned, is 105 mm.
. No cs ae of a deipaine appear to have been preserved than that already mentioned.
o parts of the premaxilla, nor vomer, nor parietals, n ipi y
Bieaied with the bones above described. Se a ete eee
Portions of the skull of this species were described by Case as cited in the synonymy.
The supraoccipital is stated to resemble closely that of the Cheloniid, and to be quite different
from that of Dermochelys. The basioccipital resembles that of the latter species, except that
the portion belonging in the condyle is well ossified. The basisphenoid is said to resemble that
of Dermochelys, but is not so large. Case pointed out that the hinder end of the pterygoid was
as in Dermochelys, separated from the exoccipital by a lateral process of the basioccipital. The
imperfectly preserved palatines indicated that the choanz were placed far forward. The vomer
had no descending process to assist in underflooring the nasal passages. The quadratojugal
and the squamosal were found to be as in the Cope_specimen, but to the present writer it

rad

VEN

lal

/
=,

i] \ ul
SN ox
j ae
per. 3 ZS

- g ENO)

“hum

7

— pe

Fic. 248.—Protostega gigas. Skull, limb bones, and front of carapace. X4.
No. 1421 Carnegie Museum, Pittsburg.

Skull. fr, frontal; ju, jugal; mx, maxilla; nar, nares; orb, border of orbit; pa, parietal; prf, prefrontal; pmx,

premaxilla; pof, postfrontal; gu, quadrate; qj, quadratojugal; sg, squamosal.

Lower jaw. ang, angular; dart, dermarticular, or prearticular; den, dentary; hy, hyoid; sur, supraangular.

Carapace. nu. p, part of nuchal; per. 1, per. 2, first and second peripherals; r.2, second rib.

Fore limb. c, centrale; Aum, humerus; rad, radius; ul, ulna; ral?, radiale?; 7, intermedium; w/n, ulnare; pr,

pisiforme; 1-5, carpals of second row; I-V, metacarpals.
appears that Case has mistaken the upper border of the quadratojugal for the lower. The
mandible was in perfect condition. The symphysis is represented as being equal to a very little
more than one-third the whole length of a ramus. In addition to the bones found in the lower
jaw of ordinary turtles Case states that the bone called by Baur,the presplenial, by Williston
the true splenial, is present.

The bones described and figured by Cope as metapodials (Cope’s plate xii, figs. 3, 4) are
certainly not such, but epipodials. The original of his fig. 3 appears to be a tibia. The bone
on the right of his fig. 4 may be a radius. The same bone in 4rchelon, as Wieland informs
the writer, is now regarded by him as the ulna.

No. 1421 of the Carnegie Museum, Pittsburg, was secured in the Niobrara Cretaceous,
near Hackberry Creek, Gove County, Kansas. It furnishes the nearly complete skull; the
humerus, radius, ulna, most of the carpal bones, and some phalanges of the right flipper; and
the nuchal and first three right peripherals. These bones are yet imbedded in the matrix, so
that only their upper surfaces are visible. The remains have been studied and described by
Wieland, whose figure is here reproduced (fig. 248). The following measurements of the skull
are taken from his paper:

=)

194 FOSSIL TURTLES OF NORTH AMERICA.

Millimeters.
Extreme lengthiof-ramuss of lowertawcs <i csi ee eer eee 370
Extreme length/ofsymphysis of lower jaws 2.1.0. 92) s cmt soa clase 160
Length of skull from beak to end of supraoccipital spine................-- 580
Median lengthof narial opening. 22)... oe eet oe ees Oy aA 75
Width of narial opening........... Aa gs Ccpee tee eae 55
Antero-posterior length of orbit........... Rt Ahi ras Seen ete Sea She 120

It will be observed that this skull was nearly 2 feet in length. In Wieland’s figure the
suture between the parietals was omitted; but this is here supplied.

It is unfortunate that only a portion of the nuchal was preserved. Its presence would haye
settled the question regarding the identity of the T-shaped bone, which has been regarded as
the nuchal. The portion of fhe nuchal (hg. 248, nu. p) remaining with this specimen does not,
the writer believes, particularly favor the opinion that it is the T-shaped bone.

No. 1393 of the Carnegie Museum was obtained at Twin Butte Creek, Logan County,
Kansas. It is fragmentary, but presents various portions of the plastron, limbs, and skull.

Fic. 249.—Protostega gigas. 1's. Carapace of No. 1420 Carnegie Museum.
I-10, the ribs of the carapace; s, sacral rib.

Some series of the peripherals show that there was a sharp free border along each side. From
this a plate of bone from 50 to 70 mm. wide rose over the distal ends of the ribs. From the
same border another plate, from 25 mm. to 30 mm. wide, past horizontally inward below the
rib-ends. The hyoplastron and the hypoplastron taken together measure about 400 mm. in
length. ‘he greatest thickness of the hyoplastron is aan 15 mm. The hypoplastron 4 is
somewhat hinned Both xiphiplastra are present. They are of the form shown in Case’s
figure, but they are not so abruptly bent.

Little is known regarding the vertebra of this species. Cope had remains of 5, but he was
unable to determine here ‘they belonged. They probably appertained to the tail. Cope
supposed that the dorsal vertebrae possest transverse processes, but Wieland’s figure shows
this conclusion to have been erroneous. Wieland stated that a specimen at the Carnegie
Museum furnisht 6 of the cervicals, but he did not describe them. Case describes 2 caudals.
They were proccelous.

The carapace of this species is of great interest, and has been studied by Cope, Case, and
Wieland. Cope had secured portions of 10 ribs of the type specimen. He recognized clearly

iy

PROTOSTEGID&. 195

the fact that the costal plates were greatly reduced, so that the ribs were free from one another
to near their proximal ends. He supposed that he had found evidences, from the great lenoth
of the costal plates from the origin of the rib-heads to the proximal border, that rhere ereaaD
neural bones, and that the rib-heads were attacht to transverse processes. He was undoubtedly
wrong in both conclusions. Case had for examination only fragments of the ribs. He found
that the neural borders of the costal plates were digitated; and from the considerable extension
of these plates toward the midline from the origin of the rib-head, he concluded that there was
no room for neurals. He found that the costal plates extended along the ribs for about a third
of their length. Wieland had the opportunity to study a carapace, No. 1420 of the Carnegie
Museum, which showed a nearly complete series of ribs. Fig. 249, reproduced from Wiclend:
shows this carapace as seen from below. He found the neurals to be present, but of papery
thinness and much crusht down on the neural arches. Contrary to what is found in most
turtles, the first rib is not turned backward against the second. It is relatively short. The
other ribs are about 35 mm. wide at the middle of their length. The costal plates, forming the

Fic. 250.—Protostega gigas. Plastron. »,';. After figure by Case.
ent, entoplastron; hyo, hyoplastron; hypo, hypoplastron; xsph, xiphiplastron.
On the left is a number of peripherals.
disk of the carapace, extend not more than one-third the length of the ribs. The total length
of the ten dorsal centra was 680 mm. The distance between the distal extremities of the
ribs of the fourth pair was 1060 mm.

The nuchal bone of some members of the Protostegide has already been discust. Cope
figured a bone which he regarded as the nuchal. It is certainly a median bone, but it appears
to be too small to be the nuchal, and may be the pygal. The nuchal may be supposed to
resemble that of Archelon, as figured by Wieland (Amer. Jour. Sci., v., 1898, p. 17).

Of the peripherals Cope had 12, but the exact position of these could not be determined.
They were, moreover, greatly flattened by the pressure to which they had been subjected.
Some of these had only a single lamina, that rising to the ribs. Others possest, besides this, a
lamina that projected toward the bones of the plastron. The end of a rib was partly buried in
the lower surface of the upper lamina of each. The external border of each peripheral behind
the second was acute. The upper lamina was thin and its upper border terminated in digita-

196 FOSSIL TURTLES OF NORTH AMERICA.

tions. We are indebted to Case for more exact knowledge of the peripherals. He had a series
of 8 of these in their natural order (fig. 250). The most anterior was supposed to be the second.
It is slender, concave along its free border, as if to make room for free movements of the limb,
and has no pit fora rib. Itis 170 mm. long and only 30 mm. wide. The third is strong, broad,
and has a rib-pit. Its length is 170 mm. and its width 118 mm. The succeeding ones are longer
than wide and have 2 lamine, the uppermost of which is the broader. All these peripherals
are closely joined together by means of coarse sutures.

Wieland figures ( (Mem. Carnegie Mus., 11, p. 282) a portion of a nuchal bone and the first
and second peripherals. The figure i is here reproduced (fig. 248).

The hyoplastra and the hypoplastra were described by Cope as dermal bones that were
supposed to overlie the ribs. Baur’s suggestion that these bones belonged to the carapace has
been mentioned. They had been comprest until the greatest thickness was only about 15 mm.
A plastron described by the present writer showed that these bones were really thick and heavy,
the thickness amounting to as much as 45 mm. in the case of the hyoplastron. The plastron
described by Case (fig. 250) was somewhat larger than the one last referred to and furnisht
representatives of all the elements except the epiplastra. The hyoplastra and hypoplastra are
bones of an irregularly triangular form, with all the borders digitated, except over the fore and

Fic. 251.—Protostega gigas. Right shoulder-girdle and limb; dorsal view. Xs.

c, centrale; cor, coracoid; hum, humerus; int, intermedium; I-V, the digits; met, metacarpals; phal, first row of
phalanges; p/, pisiforme; pcor, procoracoid process; rad, radius; u/, ulna; uln, ulnare; 1-5, carpals of second row.

hinder limbs. From the anterior inner angle of the hyoplastron a thickening, appearing on the
lower surface as a low ridge, runs backward thru the articulation with the hypoplastron and
on backward to the xiphiplastra. From this ridge, in each direction, the thickness 1s reduced
until the borders are reacht. Evidently there were considerable spaces left between the plastral
bones and the peripherals. In the midline there was a great fontanel, which extended from
the entoplastron to the xiphiplastra. The union of the plastral bones with the peripherals was
a ligamentous one.

As stated, the entoplastron was first described by Hay as a nuchal. Case figured a more
complete specimen as a nuchal. This was found lying with its wings overlapping the anterior
ends of the hyoplastra (fg. 250). It extended from side to side a distance of 599 mm. The
greatest breadth of the wings was 131 mm. From the midline of the bone there reacht back-
ward a spine which must have attained a length equal to that of the wings. The outline of this
bone was concave in front to middle of wings, then convex. The epiplastra are unknown.

The xiphiplastra are remarkable bones. Instead of extending backward and gradually
inward as they do in the Cheloniidz, just behind their Aciculaven with the hypoplastra they
turn directly inward at almost a right angle, to meet at the midline by an overlapping joint.

The limbs of this species, as of ail fhe. Protostegidz, are modified for permanent residence
on the seas,

PROTOSTEGID. 197

Cope described and figured the humerus and some other limb bones. Case also added to
our knowledge of the limbs; to Wieland most of all we are indebted for their complete restora-
tion. The materials furnishing his observations are in the Carnegie Museum, at Pittsburg.

The scapula, with its procoracoid process, is a stout bone. The coracoid is eo long that it
reacht the pelvis. The humerus is greatly modified, resem-
bling in some respects that of Dermochelys. The fingers are
elongated to form a great paddle for beating the sea. The
length of this limb, from the glenoid cavity to the tip of the third
finger, is estimated by Wieland as being 1060 mm. The greatest
spread of the fore limbs is supposed to have been 2500 mm. For
details on the structure of the flippers the student is referred
to Wieland’s paper and to the figure here presented (fig. 251).

Fig. 252, reduced from Wieland’s paper, represents a
humerus of Protostega now in Carnegie Museum. The total
length is 340 mm.

Fig. 253, taken from Wieland, represents the hinder limb
and the pelvis. Both the pelvis and the limb resemble closely
those of the Cheloniidz. The ilium is a stout bone. The
ischium and the pubis appear to have met on the midline. The
hinder limb, in comparison with the fore limb, is relatively
longer than it is in most Cheloniide. The greatest spread of
the hinder flippers is given as 1900 mm. Wieland thinks that
four of the toes were clawed.

Estimates varying greatly have been made regarding the
size of this sea-turtle. It is highly probable that earlier esti-
mates made by Cope and Hay were too great. Cope concluded
Bey ca Proto de ed sinus. that his specimen had a total length of 12.83 feet, about 3900

Pumesu, Sc. e's mm. From the specimen studied by Hay about the same con-
clusion was reacht. The discovery by Case that the plastron
was much shortened behind caused him to conclude that the
total length was considerably less than had been supposed. He estimated the length, including
the head, as about 2270 mm. He made the length of the carapace as 1640 mm., the width as
1235 mm. However, if we may judge from the carapace described by Wieland, the width

e, ectepicondylar passage.

Fic. 253.—Protostega gigas. Pelvis and hinder limb. Xt.

astc, astragalo-calcaneum; fem, femur; fib, fibula; I-V, the digits; #/, ilium; isch, ischium; met, metatarsals;
7 p» first row of phalanges; pub, pubis; ti, tibia; 1-5, tarsals of second row.
was considerably greater than the length. It is now estimated that the length of the carapace
of the Pittsburg specimen was about 1100 mm. and the width about 1200 mm. ‘The total
length of the animal then must have been perhaps something over 2 meters. Its humerus
was 340 mm. long; that of Cope’s type, 300 mm.

198 FOSSIL TURTLES OF NORTH AMERICA.

As regards its habits, we may safely conclude that this turtle was an active swimmer on the
open seas and that it was carnivorous in its diet. Wieland is of the opinion that all the members
of this group were powerfully equipt for both swimming and attack, and may well have
hunted actively swimming prey. As to swimming, we must memember that the boldest swimmer
among turtles ‘of our day is the leatherback, iil has an elongated body. The short, broad
carapace of Protostega must have imparted to the animal an unsteady bearing under efforts to
make rapid progress.

As regards the nature of the food, the long symphysis of the lower jaw appears to indicate
a habit of “crushing hard-shelled animals, such as crustaceans and mollusks.

Protostega potens sp. nov.
Figs. 246, 254, 255.

This species has as its type No. 180 of the American Museum of Natural History. This
was collected by Mr. H. T. Martin, in 1897, in the Niobrara beds, near Elkader, Logan
County, Kansas. The individual is represented by large portions of the skeleton, but only a
part of it has been prepared for study.

There is present the hinder half of the lett side of the skull. This is strongly crusht down-
ward and toward the right side. The structure appears to be in general fue same as in P.

Fics. 254 AND 255.—Protostega potens. Basioccipital and hyoplastron of type.

254. Section across front of basioccipital. 1. 255. Hyoplastron. Xt.

gigas. Sutures are not discernible, but from the striations on the bones, their limits may be
pretty accurately determined. The orbit had a perpendicular diameter of 70 mm. The dis-
tance from the hinder border of the orbit to the posterior angle of the saleiaaeal was nearly
200 mm. On lifting the anterior end of the parietal there is exposed a broad plate of bone
which runs donmnmard from the inner border of the parietal. This is without doubt the descend-
ing plate of the parietal, whose presence has hitherto been somewhat doubtful. The occipital
condyle i is large, having a diameter of 50 mm. The bones composing it are wholly co-ossified.
Its inferior portion is eroded away. The condyle is broadly rounded behind, without trace
either of a pit or of division into its constituent three bones. The lower surface of the basi-
occipital appears to have been greatly different from that of P. gigas. Case describes the latter
as having its under surface nearly smooth and lying in the plane of the horizontal axis of the
skull. From this we may infer that this surface is nearly flat. In the present species the midline

PROTOSTEGID&. 199

of the bone is traverst by a prominent ridge, the summit of which anteriorly is about 10 mm.
wide and which expands posteriorly to fies condyle. The sides of the ridge are formed by two
bold grooves which run backward and outward from the front of the bone. Whether or not any
portion of the basisphenoid 1 is present in the fragment of bone 60 mm. long from the oce ipital
condyle is not certain. Fig. 254 1s a section taken near the front of the fragment. ‘The summit
of the ridge has been eroded off.

The carapace is represented by the midline and the ribs of the left side. It resembled that
of P. gigas, as represented by Wieland, but the ribs are free from one another to points neare1
the midline. The neurals are crusht dow n against the vertebra and most of them have been
subsequently eroded away. The boundaries of none can be traced. The distance from the
base of the first rib to that of the tenth is close to 800 mm.; the length of the first rib is 205 mm.,
that of the fifth at least 655 mm. The carapace must have had a length of about 1250 mm.
and a width of about 1500 mm. The ribs are free from the adjoining ones to about 120 mm.
of the midline.

Large portions of the plastron are preserved, but all have not yet been made available for
study. The right hypoplastron is nearly complete. Its lower surface is traverst by a low
longitudinal ridge. The length of the bone along this ridge is 400 mm. The width is nearly as
great. The right and left borders are furnisht ail numerous digitations. At the hinder end
is a notch for the reception of the xiphiplastron. Most of the process of the hypoplastron
which joined the xiphiplastron on its outer border is broken away.

‘The xiphiplastron (fig. 246, x1ph) is remarkably thin, being nowhere more than 10 mm.
thick. Itis not so abruptly turned toward the midline after Being freed from the hypoplastron
as is that of P. gigas. Its length was originally close to 375 mm. Beyond the hypoplastron
both of the borders are acute; ae inner Is ahe thinner. The outer border joined, for more than
the proximal half of its length, a process of the hypoplastron. :

The left hyoplastron (fig. 255) is present. Unfortunately many digitations are lost, so
that not all its dimensions. are determinable. From the hyohypoplastral suture to the
anterior end the length is 580 mm., measured on a straight line. From the just-named suture
to the bottom of the Gallary notch alte distance is 300mm. ‘The entire width of the bridge was
not far from 625 mm. The low ridge seen on the hypoplastron 1s continued forward on the
hyoplastron. The suture between the hyoplastron and the hypoplastron was evidently consid-
erably shorter than in P. gigas. Here the bone is about 25 mm. thick.

The T- -shaped entoplastron (fg. 246) is preserved, but lacks much of the lateral wings.
The lower surface is mostly convex, but on the outer end of each wing it is slightly concave in
all directions. The visceral surface is concave from side to side. Near the front border, at
a distance of about 25 mm. from the midline, begins a broad groove, quite deep at first, but
becoming shallower on the wings. ‘This was alimést certainly occupied by the epiplastron.
At the midline, near the anterior border, the bone is about 20 mm. thick. About 50 mm. from
the midline, on each side, there is a rough surface, as if for a ligament. To this may have been
tied the anterior end of the procoracoid process of the scapula. At the outer end of the right
wing, as preserved, the thickness of the bone is only 6 mm. Here the surface which was
covered by the epiplastron is 65 mm. wide.

The left scapula, without the procoracoid process, is preserved. Its length, trom the upper
end to the glenoid fossa, is 275 mm. The coracoid has a length of 425 mm., and a small portion
of the distal end is missing. It was not expanded at the distal end. The left humerus is well
preserved and not much crusht. The total length is 402 mm.; from the head to the distal end,
385 mm. From the head to the lower end of the radial process is 245 mm. ‘The width of the
distal end is 185 mm. The ectepicondylar passage is a foramen with a large opening on the
articular surface.

One femur, much distorted by pressure, is present. Its length is 335 mm. The diametet
of the shaft is 50 mm.

Protostega advena sp. nov.
Figs. 256-259.

The chelonian remains to which the name Protostega advena is given are the property ot
Kansas University and have the number 1209. There is no history of the time or place ot

200 FOSSIL TURTLES OF NORTH AMERICA.

collection or of the collector. There is no doubt, however, that the specimen was obtained
from the Niobrara deposits of Kansas. It consists (fig. 256) of the greater portion of the
plastron, 12 peripherals, 2 or 3 neurals, and portions of 2 costal plates. With these are some
other bones which are either undetermined or they doubtfully appertain to the specimen.

The hyoplastra and hypoplastra closely resemble those of Protostega gigas. The two of
these bones which are found on the same side were apparently united for a short distance by
a coarse suture. The two hyoplastra evidently came close together along the midline; but
the hypoplastra were widely separated. The median fontanel has therefore extended from
the hyoplastrals to the xiphiplastrals. The latter bones are not so elongated as in modern
sea-turtles and Chelydra, nor so short and abruptly incurved as in Protostega gigas. The
greatest thickness of the hyoplastrals is about 10 mm. The other plastral bones are thinner.
There are no longitudinal carine on the plastron, such as we find on that of Caretta caretta

Fics. 256-259.—Protostega advena. Portions of type. 4.

256. Plastron and peripherals, seen from above. 257. Two neurals. 258. Costal bone. 259. Postfrontal.

and Protostega gigas. Vhe forms and positions of the various bones may be seen from the
figures. The distance from the anterior border of the hyoplastron to the hinder border of
the xiphiplastron is 278 mm. ‘The entoplastron and the epiplastra are wanting.

The anterior peripherals of both sides are absent from the materials. On the right side
the most anterior peripheral present appears to be the one which has received the rib-end of
the first costal plate. This is provisionally regarded as the fourth from the nuchal bone.
The most anterior one on the left side is the fifth. On the left side one is believed to be missing
next to the pygal; while on the right side three in front of the pygal are supposed to be gone.
These peripherals prove that this individual is not a young Protostega gigas, since they are
relatively much shorter and broader than are the corresponding bones of the latter species.
They are likewise much heavier bones.

PROTOSTEGIDZ2. 201

Each of the peripherals, except the posterior three, may be said to be V-shaped in trans-
verse section, one limb of the V extending toward the edge of the plastron, the other inward
and upward toward the costal plate. The upper plates are slightly concave above; the lower
ones somewhat convex below. The concave and the convex surfaces of each peripheral come
together to form a sharp edge, and the border of the carapace so formed runs from the fourth
peripheral to near the pygal. ‘The three posterior peripherals have no lower, or plastral,
plate developt. What is regarded as the tenth peripheral has a half-pit at its hinder end.
It is therefore believed that the rib-end of the eighth costal was swung backward to be inserted
between the contiguous ends of the eleventh and the twelfth peripherals. In Caretta this rib-
end has moved backward still further and is inserted in the middle of the last peripheral.

The antepenultimate peripheral has a pit for the rib-end of the seventh costal near its
hinder end and this pit lies partly in the anterior end of the penultimate peripheral. If the
eighth costal plate is regarded as sending its rib to the last peripheral, the next peripheral in
front has no rib-end corresponding to it. In Caretta it is the antepenultimate peripheral
which receives no rib.

The peripherals are smallest posteriorly, and they increase in size as far forward as they
are represented. The fourth, the most anterior one present, has its two plates standing at an
obtuse angle with each other; the fifth has them at nearly right angles, the others at less than
a right angle. The plastral plate of the fifth is 37 mm. wide, the carapacial plate is 30 mm.
wide. Two long narrow peripherals accompany the specimen, but they appear to be intrusive
and to belong to Toxochelys. Two neurals (fig. 257) are present, probably the third and the
fourth. The more anterior is 39 mm. long and 28 mm. wide; the other 30 mm. long and 25
mm. wide. The middle line of each rises into a low carina, which on the more anterior one
rises into a tubercle. The hinder end of the anterior neural is crost by a narrow dermal
sulcus, a fact which shows that dermal scutes were present. The peripherals also are crost
by sulci, but these are broader than that on the neural.

The pygal is a rather peculiar bone, being nearly square, thick, convex on the hinder,
or upper, surface, and with a thick free border. It is 27 mm. high, 33 mm. wide and 11 mm.
thick.

With the remains described is found a detacht median dorsal tubercle exactly like those
occurring in the dorsal carina of Toxochelys; but it is regarded as foreign to the specimen,
having probably been introduced with the peripherals just mentioned.

Fig. 258 represents a costal plate of this species. It will be seen that it is less completely
ossified than the costals of our modern sea-turtles, but more completely than in even a large
Protostega gigas. Inthe figure the distal end is restored in outline from another costal present.
Measured thru the middle of the width the costal is 7 mm. thick, but near the sutural
border it becomes reduced to 3 mm. The costal figured is probably the fifth of the right side.
On it are found the sulci which separated two vertebral scutes from each other and from a
costal scute. These sulci are narrow and shallow. It is evident that the vertebral scutes
were relatively very broad, about 110 mm., nearly equal to one-third the width of the carapace.

There are present two bones which are referred to the skull; they are the two postfrontals
(fig. 259). Each is 30 mm. wide and 60 mm. long. At the hinder end the bone thins down
to a sharp, nearly smooth edge; so that it becomes probable that this edge formed the hinder
border of the roof of the temporal region; and hence, that the squamosal did not join the
parietal. The roof was probably not so extensive as in Caretta.

In the Cope collection of the American Museum of Natural History is the left humerus
of a small sea-turtle which was collected in Gove County, Kansas, in 1877, by one of Professor
Cope’s collectors. This humerus has every appearance of being that of an adult turtle. It has
suffered no compression or distortion whatever. Its length, from the proximal surface of the
head to the distal end of the bone, is 64 mm. The ulnar process rises slightly above the head.
The radial process descends 35 mm. below the proximal surface of the head. This process
is 11 mm. thick. The width of the humerus across this process is 23 mm. Just below the
process the width is 16 mm. On the upper surface of the bone, opposite the radial process,
is a deep muscular scar. At the distal end there is nearly a right angle between the surface
for the radius and that for the ulna. The ectepicondylar passage is a shallow groove close to
the radial border.

202 FOSSIL TURTLES OF NORTH AMERICA.

A wholly similar humerus is contained in a small collection of bones sent the writer from
the University of Chicago. The few skeletal bones accompanying it are not sufficient to
identify the humerus as that of P. advena, but it seems probable that both it and the humerus
in the American Museum belong here.

Genus ARCHELON Wieland.

Premaxillary beak more strongly developt than in Protostega. Crushing-surface of upper
jaw mostly on the premaxillaries; that on the maxilla extending back only to opposite the
choanz. Lower jaw with the rami not co-ossified at symphysis; at least, not until old age.
Entoplastron T-shaped, with the anterior border concave from end to end. Radial process
of humerus feeble.

Type: Archelon tschyros Wieland.

Fic. 260.—Archelon tschyros. Carapace with the entoplastron. zo.

Archelon ischyros Wieland.

Figs. 260-268.

Archelon ischyros, W1ELAND, Amer. Jour. Sci. (4), 1, 1896, p. 399, plate vi, text-fgs. 2-19; ibid., 1x,
1900, p. 237, plate ii, text-figs. 1-3, 6; ibid., xiv, 1902, p. 99, fig. 2; ibid., xv, 1903, p. 211, fig. 1;
Ann. Carnegie Mus., tv, 1906 (1907), p. 8, figs. 1, 4.—Hay, Bibliog. and Cat. Foss. Vert. N. A.,
1902, p. 440.

Protostega tschyros, Wituiston, Uniy. Geol. Surv. Kansas, 11, 1897, p. 246.—W1ELAND, Amer. Jour.
Sci. (4), v, 1898, p. 15, plate il, text-figs. 1, 2.

We owe our knowledge of this species to the study and the publications of Dr. G. R.
Wieland. All the known specimens have been found by him near the South Fork of Cheyenne
River in South Dakota, in the upper beds of that part of the Pierre formation that is below

PROTOSTEGID. 203
the Judith River formation. The species was probably the largest that is at present known
to have existed. From the length of the neck and the carapace Wieland estimates that the
total length of type specimen was about 3.5 meters. Specimen in Yale University collection.

Of the remains of this great turtle the present writer has studied only the skull. The
greater part of the description here given has been derived from Wieland’s papers. The
figures are reproduced from those papers. Fig. 260 represents the carapace as shown in
Wieland’s latest restoration of it (Amer. Jour. Sci., xv, p. 212). In this figure (p. 189) a large
bone is shown in front as the nuchal but which the present writer regards as the entoplas-
tron. This figure is based on the type specimen, except that the first rib is added from
another individual. The carapace, so far as is known, was composed of 8 neurals, 1 or
more suprapygals, 10 pairs of ribs, a nuchal, a pygal, and an undetermined number of pairs of
peripherals.

The estimated total length of the carapace, exclusive of the nuchal, is 1.7 meters; with the
nuchal, it was probably about 1.9 meters. The width, exclusive of the peripherals, must have
been about 2 meters; including the peripherals, about 2.5 meters.

The neurals are mostly broader than long. Their borders are furnisht with long and
coarse digitations, which interlock with others from the contiguous neurals and costal plates.
It is difhcult, therefore, to determine the widths of the neurals, but these widths may be taken
as from 175 mm. to 225 mm. The neurals are relatively thin, being only about 5 mm. The
median line of most of the neurals is markt by a deep and narrow groove, which becomes
widest at the center of the neural. From this center there radiate outward characteristic
surface striations. In his first description Wieland thought that these neurals probably con-

2 sisted each of paired bones. He concluded also that the longi-
Width at tudinal groove was filled with horny materials and that the animal

Rib. Length.

middlepart. may have borne a row of dorsal spines. The last one or two
7 neurals and the suprapygals have not been well determined.
; oe . Little can be said concerning the pygal. Indeed, the terminal
A 7525 78 bone shown in Wieland’s figures of the carapace is probably a
5 1020 75 suprapygal.
: bees a The ribs and the costal plates resemble much those of Pro-
8 = 60 tostega. he disk formed of the costal plates and the neurals is
2 = 35 much reduced, extending outward from the median line hardly
os =)

one-fifth the distance to the ends of the ribs Beyond the borders
of the disk the ribs are wholly free from one another. The first
rib is extraordinarily large, as compared with the same rib in other turtles, being three-fourths
as long as the second. Its lengthis 740 mm.; its diameter, about 75 mm. The other ribs have,
in the type specimen, the dimensions shown in the table.

Where the ribs emerge from the disk their thickness averages only about 25 mm. It is
thus seen that they increase much in thickness toward the middle of their length.

The bone described by Wieland (Amer. Jour. Sci., v., 1898, p. 17) as the nuchal (fig. 261)
and now regarded by the present writer as such, is roughly triangular, with a concave anterior
border. The lateral extent of the bone is 640 mm.; its antero-posterior extent, 250 mm. On
the inferior surface there is a trapezoidal elevation, which Wieland regarded as having afforded
an articulation with the last cervical vertebra. The thickness through the elevation is 35 mm.;
elsewhere, from 10 mm. to 15 mm.

Little has yet been publisht about the peripherals. A fragment of one was figured by
Wieland in his earliest description of this turtle. Ina later paper (Amer. Jour. Sci., Xv, p. 211)
he states that the inner borders of these bones are strongly digitated.

The plastron (Amer. Jour. Sci., v, p. 16) has the same general structure as that of Pro-
tostega, altho the principal bones appear to have been broader and to come nearer filling up the
median fontanel (fig. 262). As represented by Wieland, the digitations bordering them are
extraordinarily numerous and elongated. The T-shaped entoplastron (fig. 262, ent) has a
breadth of 940 mm. and a length of 450 mm. The anterior border is concave to the outer
extremities, thus differing from that of Protostega. The extremities of the wings are 280 mm.
wide. They appear in the figure to occupy their natural position on the hyoplastra. The

204 FOSSIL TURTLES OF NORTH AMERICA.

greatest thickness of the entoplastron, at the midline, is 60 mm.; at the narrowest part of the
lateral portion, 50 mm. ‘The epiplastra probably overlapt the entoplastral wings nearly to the
midline and ran backward a short distance on the borders of the hyoplastra. Wieland (Ann.
Carnegie Mus. tv, p. 8) describes what he regards as the epiplastron. For the present writer’s
opinion on this, the reader is referred to page 190.

The hyoplastra (fig. 262, hyo) have each an antero-posterior length of 1030 mm.; while the
width, inclusive of the spines, is 1100 mm. The greatest thickness is 48 mm. The articulation
with the hypoplastron is about 150 mm. wide.

The hypoplastron (fig. 262, hypo) from the hyoplastral articulation to the extremities of
the processes embracing the xiphiplastron, has a length of about 960 mm. The greatest
breadth, including the spines, is 1000 mm.; the greatest thickness is 41 mm.

Fics. 261 AND 262.—Archelon tschyros. vo. Nuchal bone and plastron of type.

261. Nuchal bone. 262. Plastron. ent, entoplastron; hyo, hyoplastron; hypo, hypoplastron; «xiph, xiphiplastron.

The xiphiplastra (fig. 262, x1ph) are each 500 mm. long, 170 mm. wide, and 36 mm. thick.
The proximal end of each fits in between processes of the corresponding hypoplastron, being
grooved to receive the borders of those processes. The distal ends of the two xiphiplastra join
at the midline by interlocking digitations. These bones are less abruptly curved than are
those of Protostega, and greatly resemble those of Protostega advena.

The total length of the plastron, according to Wieland’s figure, is about 2100 mm., being
thus longer than the estimated length of the carapace. The latter was certainly the longer.

The skull (fig. 263) of this species reacht an enormous size both relatively to the length of
the carapace and absolutely. Wieland’s restoration of the one studied by him is here repro-
duced. The same individual furnisht also a nearly complete skeleton. It was about three-
fourths the size of the type specimen. The skull has a length of 720 mm. Another, but
fragmentary specimen, indicated a skull fully a meter in length.

PROTOSTEGID&. 205

_Points to be especially noted in this skull are its long and narrow form, the long preorbital
region, the hookt beak, the posterior position of the orbits, and the upwardly directed nasal
opening. Contrary to what is usually seen in turtles, the orbits are placed in the middle of the

pa

—— pos
=

CONG

sith: ju den

Fic. 263.—Archelon tschyros. Skull. x4.

ang, angular; art, articular; den, dentary; fr, frontal; ju, jugal; mx, maxilla; nar, nares; prf, prefrontal; pal,
palatine; pmx, premasilla; pa, parietal; pof, postfrontal; qu, quadrate; guj, quadratojugal; $q, Squamosal;
st, stapedial rod; sur, supraangular; vom, vomer.

length of the head. This results from the great development of the preorbital region. The
horizontal diameter of the orbit is 150 mm. ;

Both the maxilla and the premaxille are greatly prolonged. The distance from the tip
of the beak to the anterior rim of the orbit is 240 mm.; from the orbit to the suture between the

pia
vol
cho
Hts
up
fl \
“pu = ee: = 1
ys 7 pm
von
Ne. pal. mu
pt
Fics. 264 and 265. Archelon tschyros. Skull.
264. Palatal surface. X,'g. bsp, basisphenoid; cho, cho-
—bsp ane; ju, jugal; mx, maxilla; oc, occipital condyle;
pal, palatine; pmx, premaxilla; pt, pterygoid; qu,
“a quadrate; guj, quadratojugal ; sq, squamosal; vom,
qu vomer ; vp, vomero-palatine region.
265. Side view of front. X}. mx, maxilla; nar, nares;
-sq o, orbit; pal, palatine; pmx, premaxilla; prf, pre-

frontal; vom, vomer.

maxilla and the premaxilla is about 150 mm. The tip of the premaxilla is bent down at nearly
a right angle with the axis of the skull, forming a great hawk-like beak.

The nasal opening
looks wholly upward. Its length is 120 mm.; its width, 70 mm.

206 FOSSIL TURTLES OF NORTH AMERICA.

From the front of the orbit to the quadrate the free borders of the maxilla, the jugal, and
the quadratojugal form a nearly straight line. Above the orbit the prefrontal meets the
postfrontal, thus excluding the frontal from the orbital rim. The relations of the bones behind
the orbit are in general like those of Protostega. In describing the quadratojugal of Protostega
Case appears to have inverted the bone and this has led Wieland to suppose that the bone
mentioned and others of the region are different in Archelon. Wieland’s figure of the skull
of Protostega shows that the region in question is the same in both genera. The squamosal is
figured by Wieland as sending a process upward to meet the parietal. Probably the same
occurs in Protostega. The supraoccipital is represented as very short, but there is probability
that it was longer. The width across the quadrate region is about 350 mm.

Various interesting structures appear on the palatal surface of the skull (figs. 264, 205).
As in Protostega, the basioccipital was small. The basisphenoid too appears to have been
small, but it is not well known. The pterygoids are extremely narrow. The exact relationships

scp.

A\\
NY \

Fic. 266.—Archelon ischyros. Shoulder-girdle, humerus, and a cervical vertebra. 1'0.

cer.v, third or fourth cervical vertebra; the figure on the right giving front view, that on the left a side view.
cor, coraccid; hum, humerus; scap, scapula.

of the palatines are not known. The hinder end of the vomer is missing, but it is probable that
it interposed between the palatines. The choane were placed far forward, immediately below
the external nares, and were not underfloored by the surrounding bones. The great crushing-
surface of the upper jaw was developt mostly on the premaxillaries, an unusual thing among
the turtles. On the maxilla this surface extends backward only to opposite the choane.
Behind these, the free border of the maxilla is narrow and weak. The crushing-surface was
therefore about 240 mm. long and about 140 mm. wide across the vomer. The anterior portion
of the vomer formed a boss in the center of the crushing-surface.

The lower jaw (fg. 263) was massive. Its lateral halves were not co-ossihed, thus differing
from those of Protostega. The symphysis has a length of 120 mm., the total length of the jaw

PROTOSTEGID&. 207

being 465 mm. At the hinder end of the symphysis its depth is 110 mm., and the width of
the jaw, 155mm. On the under surface the symphysial end of the jaw turns strongly upward
but the upper surface rises little. Wieland found the splenial to be present. - ,

Wieland has described 5 cervical vertebra (fig. 266, cer. v) which belonged to the type
specimen (Amer. Jour. Sci., 11, p. 401; XIV, p. 102). These centra indicate a neck of great
strength. The centrum of one, regarded as the third or the fourth, is proccelous, 95 mm. long
and 140 mm. wide. Dorsal, sacral, and caudal vertebra also are described by the same auithes

The shoulder-girdle of the type specimen was described by Wieland (Amer. Jour. Sci.
i, p. 404). The scapula (fig. 266, scap) is a stout and heavy bone, resembling that of Peo
tostega. The length of the body of this bone, from the upper end to the glenoid fossa, is
450mm. The coracoid (fig. 266, cor) is elongated and slender, as in Protostega. The length is
650 mm., the width of the distal end, 127 mm. :

A sit
Fic. 267.—Archelon tschyros. Limb bones. X 1.

fem’, left femur, dorsal surface; fem’’, left femur, tibial border; fem’, proximal end of left femur, fibular border ;
fib, fibula; hum, left humerus; rad, ulna; tb, tibia; u/, radius. The bones marked rad and u/ should
exchange places, be placed with the other ends up, and exchange explanatory letters.

The humerus (figs. 266, 267, hum) is an enormous bone, the length from the head being
580 mm.; the total length, 650 mm. The width of the distal end is 340 mm. This bone differs
from that of Protostega in having a relatively smaller head and the radial process much reduced.
Wieland describes also the radius, the ulna, and some phalangeal bones. The figures by
Wieland are here reproduced. In the figure of the fore limb the upper ends of the ulna and
the radius have mistakenly been represented as the lower. When the ends are reversed they
will have the positions that they have in Wieland’s figure of the anterior flipper of Protostega
gigas. The bones must also exchange places and legends.

The pelvis of the type specimen is described and figured in the journal so often quoted
(vol. 1x, p. 247). The figure is here reproduced (fig. 268). This pelvis is of astonishing size,
the length and the width being each nearly half the length of the carapace. In general, its

>

208 FOSSIL TURTLES OF NORTH AMERICA.

structure resembles that of the pelvis of the Cheloniidz, but it differs in having a median
bridge of bone connecting the pubes and the ischia. In this way ischio-pubic foramina are
formed, but they are of small size. As stated by Wieland, the extreme antero-posterior length
of the pelvis is 970 mm.; the extreme width, 810 mm. The fore-and-aft length of the pubis
is 460 mm. The length of the ilium is 300 mm., and its diameter, at the middle of the shaft,
is 105 mm.

The femur (fig. 267, fe) has the ratio to the humerus that it has in Caretta caretta. Its
extreme length is 460 mm. The tibia (fig. 267, 7b) has a length of 330 mm.; the fibula (fig. 267,
fib) a length of 310 mm.

As in the case of Protostega, we can not doubt the adaptation of this turtle to marine
aquatic life. Its excursions on land must have been confined to those for the deposition of

\\ nN) iy

Le
\

Fic. 268.—Archelon tschyros. Pelvis seen from below. 1o.
1], ilium; fp, ischio-pubic foramen; fsch, ischium; pub, pubis.

its eggs. We can only speculate as to what extent it spent its life on the high seas away from
the coasts. It seems probable that the broad and heavy body and the ponderous head were
obstacles in the way of sustained journeys over rough seas. Its prolonged beak, furnisht
with a broad crushing-surface, appears to indicate a diet, not of soft and actively swimming
animals, but of mollusks and crustaceans. Associated with the fossil were various genera of
tetrabranchiate cephalopods, and the jaws of the turtle seem to have been admirably adapted
to pick up and crush such objects.

Archelon marshi Wieland.

Archelon marshit, WieLanp, Amer. Jour. Sci. (4), IX, 1900, p. 248; ibid., xv, 1903, p. 215.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 440.

This species was secured by Wieland in the upper beds of the Pierre formation, in South
Dakota, on the east side of the South Fork of the Cheyenne river. It is described in the
briefest terms. The remains are stated to consist of the plastron, the humerus, ribs, and a
number of peripherals. These indicate a turtle about 11 feet in length. The humerus is
said to be rather straighter than that of 4. rschyros and the plastron relatively more massive,
being fully one-half thicker than in the latter species.

Family CHELONIID Gray.

Thecophorous turtles fitted for life on the sea. Skull with temporal region extensively
rooft over. No nasal bones. No posterior palatine foramina. Quadrate notcht behind for

CHELONIIDE. 209

the stapedial rod. Choanz placed on the line joining the centers of the orbits; the nasal
passages underfloored by plates from the vomer and the palatines. Neck short, head not
retractile. Carapace heart-shaped, excavated in front for the neck and for the fore limbs:
often with costo-peripheral fontanels. Plastron loosely and ligamentously joined to the cara-
pace; usually with median and lateral fontanels. Entoplastron small and lance- shaped.
Limbs unfitted for locomotion on the land; converted into paddles for swimming; the anterior
the more powerful. Humerus straightened and flattened; with the head nearly in the axis
of the bone and with the ulnar al radial processes nearly in the plane of the distal end;
the radial process below and free from the head. Second to fifth fingers elongated, the phalanges
without condyles; and all bound together in the skin and muscles. Cee I or 2.

At the present day the Cheloniide are represented by probably 4 genera (Eretmochelys,
Colpochelys, Caretta, and Chelonia) and 5 or 6 species. Most, if not all, of these species
enjoy a wide distribution, being found in all tropical and subtropical seas. All are seafaring
animals, coming on the land only to deposit their eggs. They are mostly carnivorous in their
food habits, but Chelonia feeds on vegetation. ;

If Allopleuron hoffmanni, of Bolland: belongs to this family, as usually supposed, the
family history extends backward to Upper Cretaceous times. Well- preserved remains of
sea-turtles belonging to the divisions of the Tertiary are not common. In America we have
a few species which are here assigned to the family with some doubt; such as those of Peri-
trestus of the Upper Cretaceous of New Jersey and Georgia and Lembonax of the Eocene of
New Jersey. It can hardly be doubted that Syllomus crispatus of the Miocene of Virginia
belongs to the family; while it is probable that the species here called Procol pochelys ee
and Chelonia parvitecta are also true Chelonidz. All of these are, however, imperfectly
known. In Europe the known Tertiary forms are hardly more numerous or better known,

Allopleuron hojjmann: is greatly specialized in some respects. Especially is its carapace
much reduced. It is improbable that from it have been derived the modern Chelonide.
It is more likely that the latter have descended from some Upper Cretaceous ancestor not
distant from Toxochelys. The ancestors of Allopleuron must have become sea-turtles long
before the Upper Cretaceous—consequently long anterior to the time when the ancestors
of our modern Cheloniidz could be called sea-turtles. It is therefore probable that 4/lo-
pleuron really belongs to a family distinct from the Chelomiude.

Key to GENERA HERE DESCRIBED.

A. First costal articulating with peripherals. Shell coarsely sculptured as in some

Mito myChidusiem see tia sac Soci omit ieee = agstrie. vie sicfrs got Estws Sela vette ey Peritrestus

AA. Costal plates articulating to peripherals and sculptured... ....... veeeeeeee. Syllomus
A! is he bones, so far as known, not articulating with peripherals and not sc ulptured.

. Plastral bones without median digitations. .... eee eae See Lembonax

aa. Plastral bones with median digitations.
b. Some neurals in contact with three pairs of costals. Rib of first costal entering
pit in third peripheral......... AEs eoe Uk eee ee ecceae Procol pochelys
bb. Neurals in contact with two pairs of costals. Rib of first costal entering pit in

itd! peripienall aiwtecs toe eu vies oe eee ess a ee es cre Chelonta

Genus PERITRESIUS Cope.

Carapace cordate, as in the Chelonide generally; the anterior peripherals suturally
joined to the costals of the first pair; the posterior peripherals joined to costals by gomphosis
of ribs only; a high dorsal keel; surface of carapace coarsely sculptured.

Type: Chelone ornatus Leidy.

In 1882 (Proc. Amer. Philos. Soc., xx, p. 144) and again in 1884 (Vert. Tert. Form.
West, p. 112) Cope characterized this genus as having 9 pairs of costals, 2 anterior peripherals
joined to the costals, and a high dorsal keel. It is now evident that he had derived his infor-
mation from a carapace sent to him by Dr. George Little, at one time State Geologist of
Georgia (Amer. Naturalist, 111, 1878, p. 129).

14

210 FOSSIL TURTLES OF NORTH AMERICA.

Cope arranged this genus among his Propleuride. The cordate form of the carapace
in the state collection at Adlanea: deeply excavated in front and pointed behind, appears to
indicate close relations with the Cheionide and to this family the species is here provisionally
assigned.

Peritresius ornatus (Leidy).

Chelone ornatus, Leipy, Proc. Acad. Nat. Sci. Phila. 1856, p. 303; Smithson. Contrib. Knowl., xiv,
1865, pp. 105, 119, plate xvi, fig. ro.

Perttresius ornatus, Copr, Cook’s Geol. New Jersey, 1868 (1869), p. 735; Amer. Naturalist, 11, 1869,
p. 88; Ext. Batrach., Reptilia, Aves N. A., 1870, p. 150; Vert. Cret. Form. West, 1875, p. 260;
Amer. Naturalist, ut, 878, p. 129.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 441.

This is yet an imperfectly known species. It was based by Leidy on conjoined portions
of two lateral peripherals, which had been found in Cretaceous greensand in Burlington
County, New Jersey. This greensand probably, but not certainly, belonged to the upper
bed. The bones are probably now in the collection of the Philadelphia Academy, but they
have not been seen by the present writer. They were described by Leidy as measuring an
inch and a half in breadth and as being we edge- shaped in section. The outer border was
acute; the inner border grooved, and eight lines, about 17 mm., high. Both the upper and the
lower surfaces were coarsely, but beautifully, tuberculated, and the tubercles showed a tendency
toward a radiate arrangement. Some of the tubercles at the ends of the peripherals are
lengthened out into ridges. Cope states that there were no indications of dermal sulci on the
bones. He mentions also a costal which he thought belonged at least to the genus.

Under the species Taphrosphys nodosus the present writer has suggested that it may be
identical with the species here described.

In the collection of the Geological Survey of Georgia is the greater portion of the carapace
of what appears to have been a large sea-turtle. This specimen was at one time in the hands
of Prof. E. D. Cope and was by him identified as Peritresius ornatus Leidy (Amer. Naturalist
1, 1878, p. 129). Considering the facts that Leidy’s type consisted of portions of two
evidently hinder peripherals and that all the hinder peripherals of the Georgia specimen are
wanting we can not be sure that the identification is correct. For the present it may be allowed
to ane Undoubtedly it was on this specimen that Cope based his definition of the genus
Peritresius. It is not known why Cope concluded that there were g pairs of costals.

The specimen here described was found by Mr. Loughridge, of the Georgia Geological
Survey, then under the direction of Dr. George Little, in fhe Ripley formation! of the Upper
Cretaceous, on Bonnahachee Creek, Stewart County, Georgia. It presents most of the carapace,
but unfortunately the left side is yet concealed by a mass of matrix. This has prevented an
accurate study of the specimen and the production of a figure. The length of the portion pres-
ent is 675 mm. ina straight line, 735 mm. over the curve. The original | length of the carapace
must have been about goo mm. In form the carapace is cordate, like that of are -tta. Anteriorly
there is an excavation in the border 200 mm. wide and about 30 mm. deep. The free border is
obtuse and the bone is about 16 mm. thick. The costals are about 8 mm. thick. The anterior
peripherals are suturally joined to the first costals. Behind this they are missing; but it is
evident that some of them were connected with the costals only by gomphosis of the ios

The most conspicuous feature of the carapace is the great dorsal keel. This begins on the
nuchal bone and continues to the rear of the carapace. Te) is thick and obtuse on the anterior
half of the carapace. Here the sloping sides of the keel are very steep, the summit is obtuse,
and the height is about 36 mm. Posteriorly the summit is more acute.

On account of the great number of fractures it is difhcult to follow the sutures. Where
observed these are coarse and zigzag. A few of the sulci are traceable. The third vertebral
scute has a width of about 125 mm. The sulci forming its lateral boundaries are nearly parallel
with the axis of the animal.

The whole upper surface of the carapace is coarsely pitted and ridged, much like that of
some species of Trionychide. 5 or 6 ridges are usually to be counted in a line 25 mm. long.

The anterior border of a second specimen is in the same collection. Found with it is the
greater portion of the united dentary bones. The triturating surfaces are flat. The length
of the symphysis is 53 mm.

CHELONIID. 2

The writer has been permitted to examine these specimens thru the courtesy of the
present state geologist, Prof. William S. Yeates. :

In the American Museum of Natural History is a small collection of bones, without indi-
cation of origin, but which are provisionally assigned to the present species. The number of
the lotis 1410. They are a part of the Cope collection and evidently were found in New Jersey.
These bones are filled with iron pyrites and they are black, with some surface stain of chocolate.
One fragment is that of a costal. The sutural border is 12 mm. thick, but thru the rib
the thickness is 17 mm. The upper surface is covered with coarse ridges and tubercles, irregular
in size and arrangement. They resemble greatly those of Amyda virginiana illustrated on
plate 96, figs. 7, 8. Another fragment appears to be the upper end of a costal, with the base
of the rib-head. The thickness varies from 7 mm. to 10 mm. The fragment is 75 mm. wide.
Another piece seems to be a part of a peripheral, showing the acute free border, but not extend-
ing to the costal border. The length of the fragment is 56 mm.; the width, 63 mm.; the thick-
ness of the upper border, 21 mm. The upper surface is convex from the free border upward,
while the lower surface is concave. One end appears to have come close to the suture, and
here the tubercles run at right angles with the suture. Those at the outer end are small and less
elongated. Between the two regions are some ridges running at right angles with the free border.

Three fragments belong to the plastron. The best of these resembles the outer end of the
left hyoplastron of the loggerhead. The fragment is 135 mm. long, 67 mm. wide, and 20 mm.
thick at the proximal end. Toward the outer end the bone thins and ends in a number of
digitations. The border, supposed to be axillary, is concave in outline, with the edge obtuse
near the digitations, but subacute more proximally. The supposed hinder border evidently
articulated with another bone, probably the hypoplastron, out nearly to the digitated border,
thus abolishing the fontanel. The greater part of the inferior surface of the bone is orna-
mented with anastamosing ridges and some tubercles, about three or four of them lying along
a line 20 mm. long.

Genus SYLLOMUS Cope.

Costal bones suturally articulated with the peripherals. Surface of carapace sculptured
with grooves and ridges. Humerus much flattened distally. Ectepicondylar passage a com-
plete foramen. Radial process remote from head of bone.

Type: Syllomus crispatus Cope.

Syllomus crispatus Cope.
Plate 32, figs. 1, 2; text-fig. 269.

Syllomus crispatus, Cope, Proc. Amer. Philos. Soc., xxxv, 1896, p. 139.—Hay, Bibliog. and Cat. Foss.
Vert. N. (A., 1902; ‘p. 442.

The remains on which this species was based are now in the American Museum of Natural
History and bear the number 6134. These remains consist of the right humerus, lacking only
the ulnar process, and 2 fragments of costals. These were collected by Cope in Miocene
deposits, on the Pamunkey River, Virginia.

The first fragment of costal belongs to the distal end of the bone (plate 32, fig. 1). The
width at the end is 47 mm., but this diminishes proximally. The thickness at the proximal
end of the fragment is 6 mm.; but at the distal end this has become only 2mm. This border
articulated by close suture with the contiguous peripheral. Doubtless the rib passed beyond
the border and entered a pit in the peripheral. The surface of the bone is sculptured with
anastomosing grooves and ridges, usually parallel with the long axis of the costal. The sculp-
ture becomes coarser toward the proximal end of the bone. Parallel with and close to the
peripheral border is a shallow groove which may be a portion of a costo-peripheral sulcus.

The other fragment of costal comes from near the neural end (plate 32, fig. 2) and the
width is 45 mm. It is crost by a narrow, but sharp, ridge, which indicates that the carapace
was traverst on each side by a lateral keel. We may also safely assume that there was a median
keel. The thickness of the bone, on what is probably the proximal side of the keel, is 7 mm.
Toward the distal end the thickness diminishes. The surface of this fragment is more coarsely
and irregularly sculptured than that of the other and the elevations vary more in size and form.
No trace of sulci appears on this fragment. A portion of the surface is, however, destroyed.

2.02 FOSSIL TURTLES OF NORTH AMERICA.

The humerus (fig. 269) resembles that of a true sea-turtle. The total length is toomm. The
distal end is broad and flat. The head of the bone is elongated reniform, the long axis being
at nearly right angles with the plane of the distal end. Its long diameter is 32 mm.; the
shorter, 17mm. The ulnar process is broken away,
but a groove separated it distinctly from the head.
The radial process is divided into two portions; one
part being on the under side of the shaft, 40 mm.
below the upper border of the head; the other part
on the radial border, still further down on the shaft.
Both portions are prominent. The narrowest part
of the shaft is 20 mm. wide and 11 mm. thick. The
distal end is 41 mm. wide. The ectepicondylar pas-
sage is a foramen. It emerges on the lower side
of the bone 10 mm. above the distal extremity.
The condyles are distinctly separated from the sur-
rounding bone. Their fore-and-aft extent is 22 mm.
The radial epicondyle is broad, thick, and flat; the
ulnar little prominent. It is remarkable that Cope
in his description of this bone regarded the anterior
border as the posterior.

Genus LEMBONAX Cope.

Fic. 269. —8 yllomus cris patus. Right . Plastron with probably 2 fontanel extending

humerus. Type. >3. from the entoplastron to the xiphiplastra. No
digitations of bone proceeding from the plastral
bones toward the midline. Epiplastra firmly sutured
to the hyoplastra, the suture oblique to the midline; the xiphiplastra similarly joined to the
hypoplastra, the suture at right angles with the midline.

Type: Lembonax polemicus Cope.

On left, the ventral surface; on right, the radial border.

The position of this genus is very problematical. Cope concluded originally that the
relationships were with the Chelydride rather than with the Cheloniidz. At a later time he
stated (Amer. Naturalist, xvi, 1882, p. 989) that not enough was yet known to assure us to
what family the genus belonged, except that they were not “Trionychide. Nothing has been
added to our knowledge on that point since that time. Cope referred two addigonal species,
L. propyleus and L. isulariss to the genus. While the present writer retains these species
in this genus provisionally, there appears to be no evidence whatever that they belong there.

Ror want of knowledge where Lembonax polemicus belongs it is here referred to the
Cheloniide.

Lembonax polemicus Cope.

Fig. 270.

Lembonax polemicus, Corr, Ext. Batrach., Reptilia, Aves N. A., 1870, p. 168.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 444.

This species was sent to Professor Cope from the Eocene greensand near Farmingdale,
Monmouth County, New Jersey. The type and only known specimen is now in the Agiencan
Museum of Natural History and bears the number 1134. It furnishes a portion of the plastron
and the base of the scapula. The materials indicate a large individual, but they furnish
meager information regarding its structure and relationships.

The most important parts of the plastron are a portion of the right hyoplastron and a
portion of the right hypoplastron. The outer borders of both these bones are wanting.

The hyoplastral fragment (fig. 270) has at present a length of 233 mm., having apparently
lost a slight portion since it was studied by Cope. The greatest width is 136 mm. The thick-
ness varies from 10 to 15 mm. Anteriorly the bone terminates at the union with the epi-
plastron. Posteriorly, there is no indication of suture with the hypoplastron, and this may
have been farther away than indicated in the figure. The inner border of the bone is thick,

CHELONIIDA. 212
obtuse, and along the hinder third is somewhat dentated. Anteriorly, the upper surface is
furnisht with ridges which are sharp and prominent as they approach the free inner border,
but which become obsolete in the opposite direction. These ridges seem to diverge from the
anterior buttress of the hyoplastron (fig. 270, C), if such
existed. At the anterior end of the bone the inner border
turns slightly outward and, at an angle of about 75°, meets
the sutural border for articulation with the epiplastron (fig.
270, Ato B). These bones were not joined by squamosal
suture, as they are in the Cheloniide and the Chelydridz,
but by dentated suture. The lower surface of the bone is
smooth and convex, especially transversely. The upper
surface is concave. At the anterior end of the bone, on
the upper surface, 190 mm. behind the anterior end (fig.
270, C), is a slight elevation, as if it were the base of an
axillary buttress. The lower surface of the bone just behind
this point also indicates that the plastron rose toward the
carapace,

The portion of hypoplastron has a length of 155 mm.
and a width of 125mm. Anteriorly the suture for the hyo-
plastron is missing. The inner border is subacute and
smooth, thus differing from the corresponding border of the
hyoplastron. The suture for the xiphiplastron runs at right
angles with the midline. It shows that the two bones were
firmly united by coarse interdigitating teeth. ‘Toward the
outer border the bone has a thickness of about 13 mm.,
but this diminishes slowly toward the inner border. As the
outer border is approacht, the bone begins to ascend in a
decided manner, as if approaching the carapace (fig. 270,
D). If this conclusion is correct, as indicated by both hyo-
plastron and hypoplastron, these bones were, relatively to
their length, very narrow; and there is indicated a wide fonta-
Fic. 270.—Lembonax polemicus. nel, that extended from the entoplastron to the xiphiplastra.

Portion of plastron. Type. 4. It seems improbable that the inner borders came into close
No. 1134 A.M.N. H. proximity. There were certainly no digitations extending
Mice pecdecior arietlation with the epi: from the hyoplastron and hypoplastron toward the mid-
plastron; C, base of axillary buttress; line, as there are in the Cheloniide and the Chelydride.
D, probable base of inguinal buttress; A fragment of bone present indicates that the hyohypo-
a ice eas ke MIDRPIAT On: plastral suture was formed by the interdigitation of finer
processes than that of the hypoxiphiplastral suture. On the anterior end of the fragment of
hypoplastron there are traces of this suture, so that this bone appears to have had a fore-
and-aft extent of about 170 mm. : —

The fragment of scapula present was that of a very large turtle. It is possible that it did
not belong to the same individual as the plastral bones. The long diameter of the neck of
the bone is g8 mm.; the short diameter, 42 mm.

Lembonax? insularis Cope.
Fig. 271.

Lembonax insularis, Cope, Proc. Acad. Nat. Sci. Phila. 1872, p. 16.—Hay, Bibliog. and Cat. Foss.
Vert. N. A., 1902, p. 444.

Professor Cope’s materials representing this species were meager and his descriptions of
it unsatisfactory. Nor have the means for increasing our knowledge of it been augmented;
they have even been reduced. In the American Museum of Natural History there is a lot of
bones labeled by Cope as the type of his Lembonax insularts, and bearing the museum's
number 2347. This lot came to Cope from the Eocene bed of greensand at best evan
Burlington County, New Jersey. Cope stated that the species was based on nuchal anc

214 FOSSIL TURTLES OF NORTH AMERICA,

peripheral bones; but he also exprest doubt whether these bones might not rather belong
to the rear of the carapace. Among the bones in the lot mentioned there is none that can be
recognized as a bone belonging in the midline. Fragments are found which, when fitted
together, furnish fig. 271. The: bone markt by 1 is certainly that called by Cope the first
marginal. It seems impossible to determine just where it belonged. It is, for various reasons,
improbable that it belonged in front. Hence, assuming that Cope had a symmetrical bone
which joined the supposed first peripheral, the latter is here taken to belong behind and to
be the last left peripheral.
Cope estimated the length of the bone 1 to be 153 mm. It is not known whether he took
account of the narrow fragment on the right of the figure; but there is no doubt that this
fragment belongs where it is placed.
ak The length of the bone then, not includ-
ing a deeper plate on the right that
sould be hidden when the hone joined
the one next to it, is 165 mm. The
greatest width, omitting a deep sutural
: 7 plate, is 100 mm. The thickness on the
\ a wale y right side is 27mm. The greatest thick-
ness is to the left of the middle of the
length and is 45 mm. Cope states that
this is the thickness nearthe suture of the
second peripheral; from which expres-
sion we may infer that the narrow frag-
ment on the left of the hgure, markt 2,
is a part of the penultimate peripheral.
The free border of the bone 1, so far as
represented, is thick and obtuse. Fig.
271 gives a section froma to 6. The free

Fic. 271.—Lembonax insularts. Fragments of two bones

F : ete od
of the carapace, with section of one. Type. . Lenierotens bone,on the left, projected
a to b, direction of section. 1, probable last peripheral; in an obtuse angle. It appears improb-
2,iprobable penultimate peripheral, able that such’ an irregular border

would be found on the front of the carapace. The upper surface is convex and undulating
but there is no definite sculpture. ‘Toward the free border the surface is pitted and rough.

Seen from below the bone is concave. Near the hinder border of the narrow fragment on
the right is a prominent ridge. A suspicion is awakened that this is the fragment which Cope
mentions as bearing the support of a vertebra. The ridge mentioned continues for some
distance on the larger part of the bone of which the fragment is a part. Behind it, on the
larger fragment, are two equally prominent ridges, followed by some smaller ones, and these
are separated by deep grooves. What is the meaning of these grooves and ridges can not be
determined. It is possible that the median bone, whether nuchal or pygal, sent a process
along the under surface of the bone 1, two-thirds its length.

The bone shown on the left of the one indicated by 1 has a thickness of 33 mm.; and it
is possible that this is a part of what Cope called the nuchal. In that case the bone 1 would
be either the right ultimate peripheral, or first left peripheral.

As in the case of L.? propyleus, it is impossible to state with certainty that this species
belongs to the genus Lembonax.

Lembonax? propylzeus Cope.
Fig. 272.
Lembonax propyleus, Corr, Proc. Acad. Nat. Sci., Phila. 1872, p. 15.
Lembonax prophyleus, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 444.

The type of this species is now in the American Museum of Natural History, and has
received the number 1310. This specimen was found in the Eocene greensand, in the vicinity
of Farmingdale, ie aioush County, New Jersey, the same formation and locality that furnisht
the type of F the genus, L. polemicus.

CHELONIID®. 215

The type specimen (fig. 272), all that is known of the species, consists of a nuchal bone, a
considerable part of the first left peripheral, and a fragment of the right.

The species is remarkable on account of the great excavation in the front of the nuchal,
reminding us of that of the nuchal of 4/lopleuron hoffmani (Gray). The individual was a
large one, the distance between the extremities of the nuchal being about 225mm. The antero-
posterior extent of the bone, at the midline, is 105 mm. The thickness on the midline and half-
way between the fore and hinder borders is 25 mm. The anterior border is subacute, except
toward the extremities, where it becomes thick and obtuse. In the hinder border there is a
notch for the front end of the first neural bone.

The border for union with the first peripheral is beveled, so that the first peripheral some-
what overlaps the nuchal. The suture between the two bones is a coarse one. A portion of
the border for union with the first costal presents a kind of tongue-and-groove joint, there being
on the edge of the nuchal 2 grooves and 3 slightly projecting lamine. : :

The upper surface of the bone is smooth and there are no traces seen of the presence of
sulci. On the under side of the bone, there is, on the midline near the hinder border, an eleva-

Fic. 272.—Lembonax propyleus. Nuchal and portions of right and left first peripherals.

Type. X#.

tion that probably furnisht an articulation for the neural spine of the first dorsal vertebra.
There is no surface for articulation with the last cervical, such as is found in the living
Chelonidz.

Cope referred this species unqualihedly to the genus Lembonax and stated that it threw
much light on the character of the genus. As there are no carapacial bones accompanying the
type of L. polemicus and no plastral bones accompanying the type of his L. propyleus, it is
difficult to understand why they should be so confidently referred to the same genus. On the
other hand, it is possible that both types belong to the same species.

Genus PROCOLPOCHELYS nov.

An imperfectly known genus of Cheloniida. Shell large, with thick and heavy neurals and
costals; two or three pairs of costals articulating each with 3 neurals. The neurals probably
exceeding 8 in number. First costal plate of each side suturally articulated with the nuchal
and the first peripheral; its rib-end entering pit in third peripheral. Large fontanels between
the costals and all the peripherals behind the first.

Type: Chelonia grandeva Leidy.

The known materials of the type of this genus lack much of yielding a satistactory knowl-
edge of the characters of the genus. Nevertheless, it seems evident that Leidy’s species does
not belong to the same genus as Chelonia mydas. Cope referred the species to his genus
Puppigerus; but, inasmuch as Lydekker in 1889 (Cat. Foss. Reptilia, 111, p. 52) made Ch

216 FOSSIL TURTLES OF NORTH AMERICA.

longiceps the type of Puppigerus, and the latter 1s not congeneric with Chelonia grandeva, this
species can not be placed under Puppigerus.

A study of the known materials of Chelonia grandeva makes it apparent that the first
costal bone was articulated with the nuchal and the first peripheral of each side and that some
of the costals were articulated proximally with 3 neurals each. In these respects the species
differs from any belonging to either Chelonia, Eretmochelys, or Caretta,

As regards the relations of the costals to the neurals, we find similar conditions in a spec-
imen of Colpochelys kemp: in the American Museum of Natural History. In this there are
apparently 13 neurals, and the costals of the third, fourth, fifth and sixth pairs articulate each
with 3 of these neurals. Nevertheless, nearly all the neurals are hexagonal, none octagonal,
as in Testudo, where some costals articulate with 3 neurals.

On a comparison of the widths of the costals with the lengths of the neurals we find a
confirmation of the conclusion that there were, as in Colpochelys, more than 8 neurals.

But while agreeing with Colpochelys in these respects Procol pochelys differs from it in
another. In Colpochelys the end of the rib of the first costal bone enters a pit in the fourth
or fifth peripheral, while in Procol pochelys grandeva, as in most Cheloniidz, the end of the
first costal rib enters a pit in the third peripheral.

Procol pochelys is therefore distinguisht from all the hitherto recognized genera of Che-
lonide.

On pages 8, g, and 10 Colpochelys kemp: has been referred to the genus Lepidochelys.

Fics. 273 AND 274.—Procol pochelys grandeva. Neurals. X.

273. Two neural bones. Type. 274. Neural. No. 1027 A. M.N.H.

Procolpochelys grandeva (Leidy).
Figs. 273-280.

Chelonia grandava, Leipy, Proc. Acad. Nat. Sci. Phila., v, 1851, p. 329; Ibid., vit, 1856, p. 303.—
Corr, Cook’s Geol. New Jersey, 1868 (1869), p. 738; Ext. Batrach., Reptilia, and Aves N. A.,
1870, p. 153, figs. 40, 41.—Maack, Paleontographica, xvi, 1869, p. 283.

Puppigerus grandevus, Corr, Ext. Batrach., etc., 1870, p. 235; Proc. Amer. Philos. Soc., x1v, 1875, p.
363.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 443.

Dr. Leidy’s Chelonia grandeva is an insufhciently known species. The type belongs to
the Philadelphia Academy. It consists of three neural bones which had been found in what
is regarded as Miocene marl, in Salem County, New Jersey. One of these neurals appeared
to Leidy to be the first. A portion of the anterior end had been broken off, yet the part
that remained was 67 mm. long and 48 mm. wide. The other two neurals were hexagonal,
as wide as long or wider, and each had a posterior process, showing that some of the neurals
were sharply notcht in front. One of these (fig. 273, @) was 54 mm. long, 67 mm. wide, and
15.5 mm. thick; the other (fg. 273,4) was 58 mm. long, including the process, and 58 mm. wide.

Cope, in 1870, as cited, further described the species. He had some fragments of costals;
a fragment of probably the nuchal; the scapula, which he figured; and what he described as
the femur, but which was evidently the humerus, as indeed he says it was in his explanation

CHELONIIDA. D7
of the figures on page 11. These came from Shiloh, Cumberland County, New Jersey. These
specimens are now in the American Museum and have the number 1319. The scapula re-
sembles that of Caretta, except that the upper end is more flattened. The humerus is now
missing from this lot of bones. The radial process is stated to have been on the shaft some
distance below the head. The costal plate is 82 mm. wide and 13 mm. thick. This and other
fragments of the costals show that these bones were not suturally joined to the peripherals;
but also that there was no considerable interval between them, the projection of the rib being
short. With this lot is the “‘nuchal or marginal vertebral” mentioned by Cope. It appears to
be the left end of the nuchal. The thickness at the median end of the fragment is 15 mm.,
that near the junction with the first costal, 21 mm. The first peripheral sent a thin process for
some distance beneath the nuchal, near the anterior border.

Cope mentions another specimen, belonging to the Philadelphia Academy, which presented
4 peripherals and a fragment of a hypoplastral. A peripheral, believed to be the third, had a
length of about 47 mm., and a width of 21 mm. Cope concluded that the rib of the first costal
did not run parallel with the hinder border of the costal, but approacht the hinder border
toward the distal end. Another peripheral belonging near the middle of the series was trigonal
in section, measuring 59 mm. across the lower face and 45 mm. across the inner, or visceral,
face. This and two other peripherals were emarginate at the middle of the outer border. The
dermal sulcus crost the peripherals a little behind the middle.

In the American Museum of Natural History is a lot of fragments labeled by Cope
as belonging to this species. The catalog number is 1027; the locality uncertain, but probably
in New Jersey. A neural appears to confirm Cope’s determination. This neural (fig. 274) is
63 mm. long, in the midline of the upper surface and including the process. The width is
71mm.; the thickness, 16mm. The anterior border is beveled so that the neural was oyerlapt
somewhat by the preceding neural; and the hinder border similarly overlapt the succeeding
one. A peripheral, probably the second, is $5 mm. long, 47 mm. wide at the middle of the
length, and 20 mm. thick. The outer border is obtuse; the inner, acute (fig. 275). Frag-
ments of three other peripherals belonged probably near the rear of the carapace; at least,
they have a much narrower visceral face than those described by Cope. One has the upper
and lower faces 48 mm. wide; the inner face only 19 mm. The other bones throw little
or no additional light on the species.

In the paleontological collection at Princeton University is a lot of turtle bones that are
labeled as having been received in December, 1879, from Mr. George Erety Shoemaker, now
of Philadelphia. This gentleman writes that these remains came from a marl bed near Shiloh,
Cumberland County, New Jersey. This marl belongs to the Miocene. While there is a large
amount of this material, it unfortunately consists of the remains of at least four turtles, belong-
ing apparently to 2 genera. It has been found impracticable to separate these satisfactorily,
but apparently there are parts of 3 individuals of the present species.

With these bones are 2 neurals which, it can hardly be doubted, belong to P. grandaeva.
One of these is 50 mm. long, with a short posterior spine, 48 mm. wide, and 12 mm. thick.
To it is attacht the neural arch. Another, a more posterior and smaller one, is 32 mm. long
and 44 mm. wide. Two other neurals present are only 8 mm. thick and evidently belong to
a quite different turtle.

There are in the lot, belonging apparently to P. grandeva, at least five proximal ends of
costals, and most of these show that they articulated each with three neurals, of which the
median one was the smaller. These costals vary in width from 80 mm. to 105 mm. and in
thickness from 10 mm. to 14 mm. The rib-heads were large. Besides the proximal ends of
costals, there are many other portions of these bones. A part of a right first costal requires
description. The proximal end is missing. Near the distal end the width is 110 mm.; the
thickness 12 mm. The anterior border articulated with the nuchal and with the first periph-
eral, the two sutural borders making between them an angle of about 135°. The remainder
of the distal border, 65 mm., was free from the adjacent peripheral, the second. Near the
hinder border issues the rib, making its way to the pit in the third peripheral. Only a portion
of the second costal has been recognized. Another costal, probably the fourth, is represented
by the distal two-thirds. The distal end is 133 mm. wide; the other extremity, 111 mm. The
thickness, at a distance of 85 mm. above the free border, is 18 mm.; but at the proximal end

218 FOSSIL TURTLES OF NORTH AMERICA.

of the fragment, only 12 mm. ‘The sutures are very jagged. Nearer one sutural border a
sulcus descends, which separated two costal scutes. Two other costals measure each 72 mm. in
width at the distal end. In all these the free end of the rib projected beyond the distal border.

A nuchal is represented by the greater part including the entire front. There was an
articular tuberosity for the eighth conical: the anterior border of this bone was 200 mm.
long. It is excavated somew hat for the neck and head. The upper surface is quite convex
from side to side. Antero-posteriorly the bone measures g6mm. ‘The front border is obtuse;
behind it a short distance the thickness is 16 mm., increasing at the ends of the bone to 20 mm.
The hinder border joined suturally the first costal bone.

The first left peripheral is connected with the nuchal. It is 110 mm. long and 80 mm.
wide. The hinder border articulated with the first costal. The free border is obtuse and the
distal end is 18 mm. thick. There is present the proximal end of another left first peripheral
which is considerably thicker than the one just described.

What are evidently right and left second peripherals, of an individual smaller than either
of the above, are present. The proximal end of the one of the left side is 65 mm. wide, whereas
the distal end of the left first, described above, is 72 mm. wide; besides, the two do not fit

Fics. 275-280.—Procol pochelys grandeva. Various peripherals. X32.
/) Beli? 3

275. Section across middle of supposed second peripheral; free border toward
right. No. 1027 A.M.N.H.

6. Section at anterior end of second peripheral. Princeton Univ. Coll.

7. Section near hinder end of third peripheral. Princeton Univ. Coll.

. Section near front end of supposed fifth peripheral. Princeton Uniy. Coll.

g. Right hinder peripheral, view above. Princeton Univ. Coll.

o. Upper surface of supposed eleventh peripheral. Princeton Univ. Coll.

vw NK
i i i |
oo

together as they should if they belonged to the same oe No differences are seen
that indicate different species. This second peripheral (fig. 276) is 95 mm. long, 64 mm.
wide and 22 mm. thick proximally; 51 mm. wide and 25 mm. thick distally. The anterior
border is obtuse, the hinder acute and with suture for a costal. The succeeding, or third,
peripherals are joined to those just described. They measure about 95 mm. along the free
border and are 70 mm. wide at the distal end. A ridge that begins on the inferior surface of
the second becomes more conspicuous near the outer border of the anterior half of the third;
and just above it, near the front of the bone, is the pit for the rib of the first costal. Fig. 277
is a section at the hinder end of this peripheral.

There are present nineteen peripherals, not counting the part of a first which belongs to
the larger individual. At least three are not at all represented; but at least two that are

CHELONIID. 219

present on one side are not represented by their fellows of the opposite side. ‘There is therefore
both a redundancy and a shortage. Evidently neither fourth peripheral is present. There
are representatives of 3 peripherals, probably the fifth, sixth, and seventh of the left side.
The supposed fifth (fg. 278) is gg mm. long and consists of two plates which meet each other
at an acute free border. The two succeeding this, the sixth and the seventh, are damaged,
but the faces make a smaller angle with each other. The fifth presents an extremely shallow
rib-pit, located in the hinder half of the length. It is highly probable that these peripherals
belong to a turtle of some other genus.

On the left side are three peripherals following in their natural order. Each of these
has three faces, a somewhat convex upper face, a flat lower face, and a channeled visceral
face. The rib-pit of the first one is a little behind the middle of the length. This bone
resembles one in lot number 2215, of the American Museum mentioned above; but both sides
of the latter are flat. The bone under description is 125 mm. long, 64 mm. wide in front, and
22 mm. thick. The next one is a very little shorter and slightly narrower. It presents no pit.
This is in the front end of the next peripheral, close to the suture. This next bone is 115 mm.
long, 46 mm. wide anteriorly and 21 mm. thick. In general, the section of it resembles that
of the first of the three here described. Bones corresponding to the second and third of those
just described appear to be represented on the right side of the animal. On this side the pit
which was in the front end of this third of the side is moved forward to the left junction between
the two bones. On this side, too, the hinder of the two is broken, but both ends of it appear
to be present. Following what almost certainly is its hinder end is a similar peripheral, with
its hinder end missing. This bone has a small pit for a rib. The inner, or visceral face, is 21
mm. wide.

Besides these peripherals there are four others present which require consideration. Two
of these are corresponding bones of opposite sides. Fig. 279 represents the one taken to
belong to the mght side. It will be observed that there is a decided change in the direction
of the curve at the supposed anterior end. This bone is 88 mm. long and 48 mm. wide at the
sulcus. On its channeled inner face, at the end of the sulcus, is a deep pit fora mb. A portion
of another peripheral is attacht to what is supposed to be the anterior end of this curved
peripheral. Its inner face is narrower.

The curved peripheral of the other side has, at some period of life, had the supposed
anterior end damaged, so that it has the appearance of having formed a false joint with its
contiguous peripheral. Attacht to the hinder end of this bone is another peripheral (fig. 280)
whose fellow is not present. It is 105 mm. long. The inner face is channeled but there is
no pit. One end, supposed to be the posterior, is narrow—only 24 mm. wide. It is probable
that this bone is the eleventh and that the narrow end joined the pygal.

To add to the difficulties, there is present what appears to be the left half of a pygal bone.
This was 86 mm. wide and 65 mm. high. It articulated suturally with a suprapygal and
laterally by its whole height with the contiguous peripherals, the eleventh pair; but certainly
not with the one regarded above as the eleventh.

Portions of a large thick plastron are present. One piece may be part of a hyoplastron.
A free border, probably the outer, is digitated. One border articulated suturally with another
bone, supposedly the hypoplastron.

On the nuchal bone the sulcus bounding posteriorly the nuchal scute or the first marginal
is 44 mm. behind the free border, near the midline and 54 mm. from the border at the outer
end of the bone. The limits of the nuchal scute can not be made out. On the first and second
peripherals the costo-marginal sulcus is seen running nearer the costal margins of the bones
than the free margins. Posterior to these the costo-marginal sulci doubtless lay on the intervals
between the costal and peripheral bones. Each peripheral is crost by a sulcus separating
two marginals.

The outer surfaces of all the bones are smooth, except that they are markt by numerous
vascular grooves.

In the paleontological collection at Rutgers College, New Brunswick, New Jersey, are
found one peripheral and one complete costal which are labeled as belonging to this species
and as having come from the Miocene marl at Tinton Falls. There is probably an error in
the locality.

220 FOSSIL TURTLES OF NORTH AMERICA.

The peripheral appears to be the second of the series. Its length is 116 mm.; its greatest
width, 66 mm.; and the thickness, 22 mm. This is reduced gradually to the acute hinder
border. The anterior border is obtuse.

The length of the costal, omitting the portion of the mb projecting from the peripheral
border, is 220 mm. The width is 87 mm.; the thickness 11 mm. at the proximal end, 14 mm.
distally. Proximally the costal articulated with 3 peripherals, as we have found to be the case
with some of the costals of the Princeton specimen. “The middle and smallest of these neurals
was crost by a sulcus which divided two vertebral scutes. “This sulcus is 36 mm. long on the
costal, a fact that indicates that the vertebral scutes were not wide.

The surface of the bone is smooth, but markt by vascular grooves. The distal border was
not articulated to the peripherals, except by gomphosis of the end of the rib.

Genus CHELONIA Brongniart.

Cheloniide with persisting costo-peripheral fontanels; four pairs of costal scutes; jaws not
hookt; the grinding-surface of each maxilla with a prominent tuberculated ridge which
terminates in front in a sharp tooth and which does not extend on the narrow premaxilla.
Limbs each usually with a single claw.

Type: Chelonia mydas | Linneus).

To this genus there is assigned, with doubt, a single species of North American fossil
turtles. It is ahae called by Cope Puppigerus parvitectus. In the writer’s Bibliography and
Catalogue, 1902, p. 443, this species and Leidy’s Chelonia grandeva were catalogged under
the genus Puppigerus; and he would be glad to retain them there were it possible. In that
work it was stated that the type of Puppigerus was Leidy’s Chelonia grandeva; but the fact
was overlookt that Mr. Richard Lydekker had, in 1889, chosen as the type of that genus Owen’s
Chelone longiceps. According to Lydekker, Puppigerus becomes a synonym of Lytoloma Cope.
It is possible that such 1s er case; but it appears more probable that Puppigerus i is a distinct
genus, with P. longiceps as its type. The writer can not believe that Leidy’s C. grandava
is congeneric with P. longiceps and he has for that reason proposed for C. grandava the generic
name Procolpochelys. Furthermore it is improbable that parvitecta belongs i in the same genus
as Leidy’s grandava.

About the only reasons for placing the species parvrtecta under Chelonia are that we thus
avoid erecting a new genus on extremely insufhcient materials and that we return the species
to the genus to which it was originally referred, which genus 1s probably not far from the true
one yet to be establisht.

On page 143 of the Proceedings of the Philadelphia Academy for 1867, Cope described
fragments of what he regarded as two species of Chelone; but he applied no specific names to
these. In the Miocene volume of the Maryland Geological Survey, 1904, page 63, Case has
copied Cope’s descriptions. Case has also described and figured (op. cit., p. 64, plate xxv1,
fig. 5) the proximal portion of a scapula which he refers to an unnamed species of Chelone.
This, as well as Cope’s specimens, was found in the Calvert formation of the Miocene. These
remains are not generically determinable.

Chelonia? parvitecta Cope.

Plate 32, fig. 3.

Chelone parvitecta, Corr, Ext. Batrach., Reptilia, Aves N. A., 1870, p. 155.

Chelone parviscutum, Cope, Cook’s Geol. New Jersey, 1868 (1869), p. 738.

Chelone parviscutatus, Cope, Amer. Jour. Sci. (2), 1, 1870, p. 138.

Pupptgerus? parvisc utum, Core, Ext. Batrach., Reptilia, Aves N. A., 1870, p. 235, 244.
Puppigerus parvitecta, Corr, Proc. Acad. Nat. ae 1872, p. 15

Puppigerus parvitectus, Hay, Bibliog. and Cat. ves Vert. N. A., 1902, p. 443.

The present species, whose specihe name has been so greatly abused, has as its type a
single costal plate, which is now in the American Museum oe Natural History and bears the
Dee 1318. It was found at Squaankum, Monmouth County, New Jersey, and was supposed
by Cope to have come from the Miocene marl; but this is Lower Eocene. He reported having
found another costal in Charles County, Maryland.

CHELONIIDE. 22k

The costal here described (plate 32, fig. 3) appears to have been the sixth of the right side,
and to have belonged to an individual whose carapace had a length of about 400 mm. The
length of the bone, from the neural border to the distal end, is 125 mm. The width at the
middle of the length is 44 mm. The thickness at the sutural border is 5 mm. The rib adds
about 3 mm. through the middle of the width. The distal end of the bone is cut off obliquely
and the margin 1s smooth, showing that there were costo-peripheral fontanels and no suture
with the peripheral.

On the proximal end of the upper surface appears a portion of a vertebral scute, probably
the fourth. The outer angle is distant 45 mm. from the neural border and the angle is less than

= : :
go°. The sulcus between the third and the fourth costal scutes runs on the bone near the
posterior border.

The upper surface of the bone is markt by numerous vascular grooves. In general, these
run toward the distal end, branching and anastamosing. When followed toward the proximal
end they soon enter the bone. In the area of the vertebral scute the surface is pitted by vascular
openings. The anterior border of the bone is grooved somewhat at right angles with the
sutural edge.

Family CHELYDRIDZ Agassiz.

Plastron loosely joined to the carapace; consisting of nine elements and considerably
reduced. The entoplastron T-shaped; the bridge narrow. Nuchal bone with long costiform
processes. A full series of neurals. Skull with temporal region incompletely rooft over; the
postfrontal bones large. Quadrate notcht for passage of the stapedial rod. Crushing-surfaces
without ridges and processes. Caudal vertebra mostly opisthoccelous.

At the present day this family is represented by 3 genera, Chelydra and Macrochelys of
North America and Devista of New Guinea. The first contains two species; Macrochelys
and Devisia only one each. Chelydra serpentina is the best-known species and ranges east
of the Rocky Mountains from Canada to Ecuador.

The members of this family are regarded as being among the most primitive of the living
turtles. Nevertheless, known remains of the family have not been found in deposits earlier
than the Upper Oligocene. Chelydra murchisoni is found in the Upper Miocene of Switzer-
land and C. decheni in the Upper Oligocene of the Rhine region, near Bonn.

While the Chelydride are in many respects primitive in their structure, in other respects
they have deviated considerably from their Amphichelydian ancestors. The roof of the tem-
poral region has suffered considerable reduction. The plastron has undergone reduction.
The writer can not believe that the opisthoccelous caudal vertebra are primitive. The costi-
form processes of the nuchal are a late acquisition.

As the writer has stated elsewhere, he holds that the Chelydrida are related to the Chelo-
niide through some Cretaceous ancestor of Toxochelys. Altho he has indicated (Bull. Amer.
Mus. Nat. Hist., xx1, 1905, p. 167) that the Emydide and the Testudinide sprang from the
Chelydride he is now inclined to hold that they had their origin from the Dermatemydide.

Genus ACHERONTEMYS Hay.

A genus of Chelydride. Carapace broad, considerably deprest. Neural bones eight,
about as broad as long, mostly hexagonal, with the broader end forward. A single broad
suprapygal. Peripherals, 11 pairs, placed opposite the ends of their respective costals. Verte-
bral scutes very broad.

Type: A cherontemys heckmant Hay.

The relationships of the present genus are yet somewhat uncertain, but they are believed
to be with the Chelydrida. A comparison of the plan of the carapace of the species described
below with those of the carapaces of Chelydra and Macrochelys (Boulenger’s Cat. Chelonians,
pp- 22, 24) will show that there are great resemblances. The nuchal bone has not the back-
ward extension seen in the Emydide. The peripherals do not alternate with the costals.
Acherontemys differs from the living genera mentioned in having the costals more closely
articulated with the peripherals and in possessing extremely broad vertebral scutes.

222 FOSSIL TURTLES OF NORTH AMERICA.

Acherontemys heckmani Hay.

Fig. 281.

Acherontemys heckmant, Hay, Proc. U.S, Nat. Mus. xxu, 1899, p. 23, plate vi; Bibliog. and Cat. Foss.
Vert. N. A., 1902, p. 446.

The type of the present species belongs to the U.S.
National Museum. It was found near Roslyn, State of
Washington, in what is known as the Roslyn sandstone,
of the Miocene formation.

The carapace (figure 281) is broad and must have
been rather deprest. There are no evidences of serrations
on the hinder border of the carapace. The length is
181 mm.; the width, 118mm. The median line appears
to have a sort of keel, with low bosses. The sutures
between the bones are distinct. There are 8 neurals. The
first is nearly square; the eighth pentagonal and elon-
gated; the others hexagonal. The nuchal is about twice
as wide as long. The peripherals are nearly square, and
those at the sides are placed opposite the ends of their
respective costals.

The sulci are distinctly imprest. The region of the
nuchal scute is damaged. The vertebrals are extremely
E. broad. The first has a width of 75 mm.; the second,

3 go mm.; the third, 85 mm.; the fourth, 75 mm.; the
fifth, 65 mm. ‘The costal scutes are correspondingly diminisht in transverse extent. The
first, fourth, and fifth vertebrals are short. In the case of the fourth this is caused by the
crossing of the sulcus between it and the third on the sixth, instead of on the fifth neural.

Nothing is known regarding the plastron of this species.

Fic. 281.—dAcherontemys heckmant.

Carapace of type.

Genus MACROCHELYS Gray.

Three or four additional, or supramarginal, scutes on each side. Orbits lateral. Tail
with small scales inferiorly (Boulenger).

Type: Macrochelys temmincki (Troost).

This genus is represented in the living fauna by the alligator snapper, a magnificent
turtle that lives in the lower Mississippi River region. It reaches a large size and has a dis-
proportionately large head.

Macrochelys floridana sp. nov.

Figs. 282-285.
Macrochel ys flortdana, Hay, Bull. Amer. Mus. Nat. Hist. XXill, 1907, p- 847, figs. I-4.

Four peripheral bones of perhaps as many individuals, a portion of the Jarman collection
in Vanderbilt University, indicate a hitherto undescribed species of alligator snapper. It was
found in what are probably Peace Creek beds, Hillsboro County, Fleada,

A fourth left peripheral (fig. 282) is 46 mm. long, 34 mm. high, and 21 mm. thick. The
upper and lower faces are of te odevate convexity mak meet in a subactite free border. At the
hinder end of the bone is an excavation for a process of the hyoplastron, occupying nearly
half the length of the bone.

The right seventh peripheral (Ags. 283, 284) is 60 mm. long, 50 mm. high, and 25 mm.
thick. The: upper border was anientced to the costal by a jagged suture. The slightly convex
upper and lower faces meet to form an acute free border. As in M. te mmunck1, there is a
long excavation for the hypoplastron.

The ninth peripheral (fig. 285) has in the free border a notch and is tootht both in front
and behind this notch. In M. temmunck: there is a single tooth, the one in front of the notch.

This species differs from the living M. temmincki in having the free border of the fourth
peripheral far less acute, the upper ee more convex, the rib-pit nearer the hinder end of the

CHELYDRID&. 223
bone, and no excavation for the hyoplastron; also in having the free border of the seventh
peripheral much more obtuse and the upper border not in sutural contact with the costal;
further, in having a single process on the free border of the ninth peripheral.

3 2% wrens
NRO oman Stonvanaeeev™ Pa

%
3
5
3
{
2
=
=
2

Sonnin

pst

Prald

Fics. 282-28 5.—Macrochelys floridana. Peripherals of type. 3.

282. Fourth left peripheral, with section across riddle of length.

283. Seventh right peripheral seen from above, with section across middle of length.
284. Seventh right peripheral seen from below.

285. Ninth right peripheral seén from above, with section near hinder end.

Genus CHELYDRA Schweigger.

No supramarginal scutes. Orbit directed outward and upward. Tail with large scutes
inferiorly (Boulenger).
__ This genus is represented in North America, in a fossil state, only by the following species.
Cope’s Chelydra crassa will be described under the genus Hoplochelys.

Chelydra serpentina Linnzus.

Testudo serpentina, Linnaus,-Syst. Nat., ed. x, 1858, p. 199.
Chelydra serpentina, SCHWEIGGER, Prod., 1814, p. 23.—BouLENGER, Cat. Chelonians, 1889, p. 20,
figs. 3, 4.

Cope (Extinct Batrachia, Reptilia and Aves of North America 1869, p. 125) reports
briefly that Samuel R. Harrison, of Easton, Maryland, had found remains of this species in
Pleistocene deposits at Oxford Neck, Talbot County, Maryland. They were accompanied
by bones of Elephas americanus, Cervus canadensis, Cariacus virginianius, and Terrapene

eurypygia.
Family DERMATEMYDID& Gray.

Plastron in most cases suturally articulated to the carapace; with an entoplastron, but
without mesoplastra; the anterior and posterior lobes usually reduced in size. Nuchal bone
with or without costiform processes. Neural bones reduced in number, except in Baptemys;
some of the hinder costal bones meeting their fellows in the midline, except in the same genus.
Peripheral bones in 10 or 11 pairs. Plastron furnisht with a full series of inframarginal
scutes, except in Basilemys. The scutes of the anterior lobe perhaps in all cases modified
from the condition seen in Baéna. Caudal vertebre in all the known forms proccelous. The
hinder lobe of the plastron often with a scar for the pelvis, but the latter never suturally joined
to the plastron. Temporal region not rooft over and no parieto-squamosal arch. Quadrate
notcht behind for the stapedial rod.

224 FOSSIL TURTLES OF NORTH AMERICA.

So far as the writer can determine, there is no good reason for separating the fossil genera
that have been arranged under the name Adocrde from the living dermatemyds. The name
Dermatemyde was employed by Gray in 1870, apparently a Sheet time before Cope pro-
posed the name Adocide, and ought, under the form Dernzatemydid@, to be used for the family.

It is difficult to frame a definition of the family. Our knowledge of the few living forms
is not complete. Of the great mass of the fossil genera we are acquainted with little more
than the shells, and often with only small portions of these. Of no fossil genus have we the
skull, except that of Baptemys. The limbs and feet and the caudal vertebra are unknown.
In the shells there is a great variety of structure. Perhaps no other family furnishes so many
deviations from what is regarded as the normal condition in turtles.

Usually in the members of this family some of the hinder neurals are aborted, a condition
that permits one or more pairs of the hinder costals to meet their fellows in the midline. In
Baptemys, however, there is a full series of neurals. In the living genera, Staurotypus and
Claudius, he nuchal bone has long costiform processes, and the possession of these has been
regarded as a characteristic of the family; but these processes are absent in Dermatemys ;
while i in Adocus and Xenochelys, and perhaps others, they are short; in Anosteira they are
absent. The plastral lobes are in nearly all cases shortened and often narrowed. In the
living Dermatemys (fig. 286) the lobes are quite
well developt. In nearly all forms the plastron
is suturally articulated with the carapace; but
in living Claudius the union is ligamentous.
In some of the fossil genera the sutures are
coarse, forming a transition from the ligamen-
tous connection to the closely knit sutures.
In Adocus and Baptemys axillary and inguinal
buttresses rise to the costals, or nearly so. In
probably all genera, except Basilemys, there
is a series of inframarginal scutes crossing the
bridge. In Xenochel ys and (penn the
number is reduced to two. In probably all
genera there is some deviation in the arrange-
ment of the scutes of the anterior lobe from the
arrangement seen in such a primitive turtle as
Baéna. In Adocus and some others, this pro-
ceeds no further than the great development of
the intergulars, by virtue ot which the gulars
are greatly reduced and pushed far from each
other. If this should in any cases have proceeded to the entire suppression of the gulars,
the usurping intergulars would be mistaken for the abolisht scutes. Undoubtedly, in some
cases, there has occurred either a coalescence or a suppression of scutes. In Baptemys
wyomingensts there are only 5 pairs on the plastron, excepting the inframarginals. Two pairs
occupy the area covered in Adocus by the intergulars, gulars, humerals, and_pectorals.
The pectorals appear to have advanct so as partly to cover the epiplastrals. Three pairs of
scutes ought to be found in front of this; but there is only one pair. In B. tricarinata, there
are apparently distinct evidences of a sulcus crossing the front of the entoplastron and the
middle of each epiplastron. This probably bounds the humerals in front.. It seems probable
that the area in front of this sulcus is occupied by the intergulars and that the gulars have
been extirpated.

The plastral scutes of 4gomphus appear to be arranged like those of Baptemys.

In Xenochelys we find the modifications of the plastral scutes to have gone still further.
On each bridge there are only 2 scutes. What we must regard as the intergulars have coalesct
into a single scute. This is followed by a scute on each side which does not come to the mid-
line. T He whole area extending from these to the femoral scutes is occupied by a single pair
of scutes. The pair of scutes ‘following the intergular may be gulars, but it appears more
probable that the pectorals have advance still furiier forward ‘fan in Baptemys and have

Fic. 286.—Dermatemys mawt. Carapace and
plastron. After Boulenger.

infm 1, etc., inframarginal scutes.

Arte

DERMATEMYDID&. 225

crowded the humerals against the intergulars into the place of the supprest gulars. Then
the pectorals and the abdominals have coalesct.
In Anosteira apparently the plastral scutes were so delicate that they left no impressions
of the sulci on the bones. ;
Usually there are no striking modifications of the scutes of the carapace; but attention
may be called to those of Xenochelys, and more especially to those of Anosteira.
As regards the geological continuance of the family, we find the earliest form, Basilem ys,
in the Judith River beds and three genera exist to-day. All together sixteen genera are here
recognized, and these have the geological distribution presented in the accompanying table.
. . . . p e D cé r 7 yx 1 ;
Geological Distribution of the Genera of B I ee * has been described from the
Dee Heald. Bruxellian of Belgium by Dr. Louis Dollo.
> _ There can be no doubt that it is related to Anos-
Formations. Genera. terra of America. The Bruxellian beds are equiv-
alents of our Wind River deposits. Anostetra
anglica has been described from the Lower Oli-
| Pleistocene....... gocene of Hordwell, England. The character of
———|— === = ~~ the sculpture and the straightness of the hypo-

= — z
IRECEN bese tearalsirr<ts Dermatemys, Staurotypus, Claudius.

Pliocene......... : : : ‘
a el ___ xiphiplastral suture suggest a closer relationship
a | with Pseudotrionyx than with Anosterra. Like
; —|——_————_—_——_——— Anostetra, Pseudotrionyx probably had only 10
| Oligocene. --| Xenochelys, Anosteira ? pairs of peripherals ;
Pere ne eA crea naptemys, ePacudotrionys, We know nothing about the history of the

Kallistira, Notomorpha, Alamos-| Dermatemydidz prior to the Upper Cretaceous.
emys, Hoplochelys. Tretosternon Owen, of the Wealden, suggests
We sbetcrerartous | Adects,, Homorophus, Zygoranima, strongly the genus Adocus; but the skull is said

Agomphus, Compsemys, Basilemys. by Dollo (Peltochelys duchastel11, Bull. Mus. roy.
Ci <a ss a a @hist. nat., Belgique, 111, 1884, p. 79) to have
the temporal region protected by a bony roof. It is easy to conjecture that some form similar
to Tretosternon was the Jurassic ancestor of the Dermatemydidz, which during the Upper
Cretaceous times evolved into so many genera and species.

As already stated, Pseudotrionyx of the Middle Eocene is evidently related to the Derma-
temydide. It is believed to be related also to Carettochelys insculpta, a species living in the
Fly River, New Guinea. Happily, our knowledge of this species has been increast by the
description of a better specimen than either of those previously known. ‘This description is
given by Mr. Edgar R. Waite in the Records of the Australian Museum, vi, 1905, pp. 110-118,
and is illustrated by four plates and three text-hgures. Baur regarded this turtle as belonging
among the Trionychidz, but as being closely akin to Pseudotrionyx and exhibiting connections
with the Dermatemydida. Waite shows that the turtle is a true Cryptodiran nearest to the
Dermatemydidz, but also as connecting the Cryptodira with the Trionychide. The animal
is certainly a Cryptodire, but not a dermatemyd. It belongs to a family near the Derma-
temydide. Probably Pseudotrionyx belonged to the same family; and a comparison of the
figures of the shell with those of Dollo’s Peltochelys duchastellit (Bull. Mus. roy. Hist. Nat.,
Belgique, 111, 1884, p. 78, plate I1) shows many striking resemblances. Waite states that
the quadrate is not completely closed behind, but that there is a posterior notch, wide but not
deeply cleft. On the other hand his figure (op. cit., plate xxvi, fig. 3) appears to show dis-
tinctly that the stapes entered the tympanic cavity by a hole in the quadrate, just as it does
in Trionyx. If this conclusion is correct, this differentiates the family from the Derma-
temydide; as does also the wide separation of the pterygoids by the palatines and the basi-
sphenoid.

It seems not unreasonable to suppose that from the Dermatemydidz there sprang the
Emydidz and the Chelydridae. From the least differentiated Dermatemydide, as ddocus,
the Emydide differ especially in the lack of intergulars and inframarginals; but both these
series of scutes might cease to be developt. In one of the earliest of the Dermatemydidz
there are no inframarginals, except at the axillary and inguinal notches. Were it not for the
intergulars and the extraordinary sculpture of Basilemys we might regard it as an Emyd.

)

226 FOSSIL TURTLES OF NORTH AMERICA.
Key to THE AMERICAN GENERA OF FossiL DERMATEMYDIDA.

A. Upper Cretaceous genera.

a’. No inframarginals, coarsely sculptured with pits, furrows and pyramidal elevations Basilemys
a2. culpturestine and, pranullater accep ei ee eee eet eee teers Compsemys
a*, Sculpture consisting of shallow pits. Borders of carapace acute-edged. Plastron

rounded in front and behind, with full set of plastral scutes. Hinder marginal

scutes srisine welllon itheicostalabones meat. «rites eee ee Adocus
a’, Like Adocus, but with axillary and inguinal buttresses and costals sending long
rib-heads/intoithe peripheralss, Bonesithimy ecient terete siesta tear Zygoramma
a’. Shell thick and heavy; the free borders of carapace thick and obtuse. Hinder
marginal scutes rising little or not at all on thecostalibonessee aera ..... Agomphus
® Vertebral es said to b lly ver th i 1 bones H hi
a®. Vertebral scutes said to be usually narrower than the neural bones... .. .........Homorophus

AA. Tertiary genera.
a‘. Like Adocus, but hinder marginal scutes not rising on costal bones. Torrejon... d/amosemys

a’. See 4. a® above. Hinder lobe of plastron pointed. Midway................... Agomphus
a®. Shell thick; free borders acute; three ridges along back; the plastron rather loosely

joined to carapace. No inguinal buttresses. Torrejon...................... Hoplochelys
a‘, Like Hoplochelys, but without inguinal buttresses. Wasatch................. Kallistira
a’. Not well known. At least the anterior peripherals obtuse. Wasatch.............. Notomorpha
a®. A full set of neurals. Carapace smooth, with a median carina on rear of cara-

pace. Plastron sutured to carapace. Wasatch, Wind River, and Bridger.... | Baptemys
a’. Shell finely sculptured. Plastron much reduced and loosely joined to the carapace.

ya tbs( reeneeee n Rr an rent on pace Oma tenikas ah onesie” eae ....... Anosteira
a’. Shell smooth; no buttresses; five pairs plastral scutes. Oligocene.............. Xenochelys

Genus BASILEMYS Hay.

Shell highly sculptured. Epiplastra much thickened. Bridge wide. Intergular scutes
present. Pectorals greatly expanded at the midline, narrowed laterally. An axillary and an
inguinal scute but no other inframarginals.

Type: Compsemys variolosus Cope.

This genus differs from other known genera of Dermatemydide in having no infra-
marginals, except the axillary and the inguinal.

Basilemys variolosa (Cope).
Plate 32, fig. 4; plate 34, fig. 1; text-fig. 287.

?Compsemys ogmius, Cope, Vert. Cret. Form. West, 1875, pp- 91, 261; Proc. Acad. Nat. Sci. Phila.
1875, p. 9; Brit. N. A. Bound. Sury., Report on aes and Resources 1875, p. 336.
Compsemys vartolosus, Cope, Proc. Acad. ‘Nat. Sci. Phila. 1876, p. 2573 Bull. U. S. Geol. Surv. Terrs.,

mt, 1877, p. 573- : lok
oe us vartolosus, LAMBE, Ottawa Naturalist, xv, 1901, p. 63, plates mi—vi; Cont. Canad. Palzont.,

I (4to), p. 39, plate u, text-figs. 4-6.
ie. vartolosus, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p- 445.
Adocus (Basilemys) variolosus, OsBorn, Cont. Canad. Palzont., 111 (4to), 1902, pp. 12, 16.
Basilemys ogmtus, HatcuHeR, Bull. U. S. Geol. Surv. No. 257, 1905, p. 76.

The type of the present species consists of nearly the whole of the plastron, various periph-
eral bones, and two imperfect costal plates. These are now in the American Museum of
Natural History, and bear the catalog number 1465. This type, with fragments of other
individuals, was collected for Professor Cope, in 1876, by Mr. Charles H. Sternberg, in the
Judith River beds of Montana. Since that time arker specimens of the species have been
collected by members of the Geological Survey of Canada, in Judith River deposits, just
north of the United States boundary line and east of the Rocky Mountain range. More
accurately, the remains were taken on Mackay Creek, along Old Man River, and on Red
Deer River.

Fig. 287 is reproduced mostly from Cope’s type, but it is probable that the fragment of
bone around the axillary notch and the piece of epiplastron do not belong to the same indi-
vidual as the remainder of the specimen, these anterior pieces being somewhat larger than we

DERMATEMYDID&. 227

might expect. The diagrammatic figure has been constructed partly from the type and
partly from materials belonging to the Canadian Survey. ; :

This species was a large one, and it is distinguisht by a rather remarkable form of orna-
mentation. The length of the plastron of the type was not far from 670 mm. and the total
length of the carapace approximated 775 mm. The form and the elevation probably resembled
closely those of the species of 4docus. The sculpture seems to be an exaggerated development
of that of the genus just mentioned. It resembles considerably that of some species of the
Trionychidz, but the pits are more commonly arranged in rows, and the intervening ridges
are more acute. Often where three ridges meet, there is formed a sharp trihedral elevation.
The effect is to produce a very rough surface. There are usually about three rows of pits
in 10 mm. The whole shell is covered with this sculp-
ture. It is best developt on the upper and lower surfaces
of the anterior and posterior peripherals. On the upper
halves of the peripherals of the bridge it may be obscure.
So also sometimes on parts of the plastron, as in the case
of the specimen in the collection of the Canadian Survey.

The bridge of the plastron is very wide antero-pos-
teriorly, the anterior and posterior lobes relatively short.
The rims of the lobes are much thickened, the interior
portions considerably thinner. The epiplastron of the
Canadian specimen (plate 32, fig. 4), which was about
as large as Cope’s more complete specimen, is 38 mm.
thick near its union with its fellow. This thickness
diminishes toward the axillary notch, where it is 28 mm.
Behind the entoplastron it is only 15 mm. or even less.
The epiplastron of Cope’s material has an extreme thick-
ness of 51mm. The hyoplastral and hypoplastral bones
are only 10 mm. thick where they join. At the inguinal
notch the rim of the hinder lobe is 40 mm. thick. This
gradually diminishes to 12 mm. near the midline behind.

The anterior lobe is about 325 mm. wide and 144
mm. long, measured from a line joining the two axillary
notches. Its sides slope forward toa rather blunt point.
The lateral face of the thickened rim stands ata right
angle with the flat lower surface of this lobe. The sculp-
ture rises on this face and extends for a distance on the
upper surface.

The entoplastron is large, being about 160 mm. wide,
but only 100 mm. long. It is hexagonal, with the lateral
borders shortest.

Fic. 287.—Basilemys vartolosa. Right On the lower surface of the front lobe is found a
ce oe Mostly from pair of large intergulars which extend backward to the
oe anterior border of the entoplastron and separate widely
the reduced gulars. The humero-pectoral sulcus is at first directed backward from the
axillary notch for about 50 mm., then is turned suddenly forward and inward to the middle
of the entoplastron. ;

The posterior lobe is approximately 340 mm. wide and only 160 mm. long. It is broadly
rounded behind. On the upper surface of this lobe is a large, smooth scar which marks the
point of attachment of the pubis.

The pectoral scutes are narrow at their outer ends. The abdominal scutes are large.
The median sulcus pursues a very irregular course from the front to the rear of the plastron.

The bridge is remarkably wide, being about 360 mm., considerably more than one-half
of the length of the plastron. ;

Behind the axillary notch there is a rather short and wide axillary scute, followed by the
narrowed lower end of the fourth marginal. The fifth marginal is likewise narrow, but the
sixth is greatly expanded. The seventh and eighth are pointed at their lower ends. There is a

228 FOSSIL TURTLES OF NORTH AMERICA.

single narrow inguinal. We see, therefore, that, excepting the axillary and the inguinal scutes,
there were no inframarginals. This conclusion is confirmed by the more complete shell of
Basilemys sinuosa Riggs.

Of the elements of the carapace the nuchal is unknown and but little is known of the neu-
rals. With the type are parts of 2 costals. One of these appears to be the eighth of the right
side. The length of the fragment is 144 mm.; its width was at least 56 mm. At the middle
of the width the thickness is 13 mm. The borders and the course of the rib on the inferior
surface show that the costal was curved backward from its proximal to its distal end. Not far
from its hinder border it is traverst by a deep dermal sulcus. The position of the other costal
fragment can not be determined.

Of the peripherals there are present an anterior one, probably the second, the lower halves
of most of those forming the bridge on the right side, and those of the right side from the
inguinal notch to the pygal. In the collection of the Canadian Survey the third right peripheral
is represented by the portion bounding the axillary notch. The greater part of the pygal is
with Cope’s type. Therefore, with the exception of the nuchal, one anterior peripheral, and
the outer halves of the bridge peripherals, we are acquainted with the whole rim of the carapace.

The anterior peripherals did not project so far beyond the soft parts of the animal as did
the posterior. The supposed second projected beyond the soft skin of the under side 52 mm.
Its length along the free border is go mm. The thickness is 21 mm. The portion which articu-
lated with the first costal is missing. The upper surface of the bone is nearly flat; the lower
is somewhat convex; the free border is acute.

The third peripheral, as represented by the Canadian specimen, has the thinner portion
which articulated with the first costal broken away. The sutural edge which joined the outer
anterior angle of the hyoplastron 1s present. On the anterior end of the outer surface is a
right-angled ridge, which farther forward passes into the sharp free border of the carapace.
Below this ridge the sculptured surface lookt downward toward the axillary notch; the surface
above the ridge was a part of the upper surface of the shell. The whole length of the bone is
about 90 mm. and its greatest thickness is 38 mm.

The figure shows what parts of the various bridge peripherals are present. Probably just
beyond the line of fracture the peripherals curved upward to join the lower ends of the costals.
This outer, or upper, portion of these bridge peripherals appears to be represented by one bone
in the Cope collection. The costal margin of this bone was about 18 mm. thick and this
border is nearly straight. The length of this peripheral is 103 mm. and it rises at least 110 mm.
The sculpture of the outer surface is not so coarse as on most of the bones.

The seventh peripheral (plate 34, fig. 1), the one entering into the inguinal notch, 1s thick
and heavy. Its length is 82 mm.; its thickness anteriorly, 44 mm., posteriorly, 20 mm.; its
height, at least 70 mm. Its free border is rounded in the middle of the length, becoming
broader and flatter anteriorly, sharper posteriorly. The figure just referred to shows the
details of the sculpture. The next four peripherals have respectively the lengths 100 mm., 87
mm., 62 mm., and 53 mm. The heights vary from at least 100 mm. in the eighth to 75 mm. in
the eleventh. The upper border of all appears to be broken away, but the suture evidently was
near. The eighth, ninth, and tenth have their outer surfaces somewhat concave from above
downward, so that these have a slight upward flare. A fragment of the pygal has on it the
descending sulcus, thus showing that the bone was about 60 mm. wide. Its free border is
acute and the bone is 18 mm. thick, 70 mm. above the free border.

The connection of the costals with some of these posterior peripherals is interesting. It is
well shown in an eighth right peripheral in the Canadian collection. This is broken so as to
show that the end of the rib beyond the costal plate extends downward into the substance of
the peripheral about 30 mm., forming a gomphosial articulation. No such articulation is seen
in the bridge peripheral above described.

The greater portion of the pygal is present in the type of the species. It had a length of
60 mm. along the free border and a height of about 75 mm. The outer surface is nearly flat,
the inner convex. The free border is acute, as is that of most of the peripherals.

So far as can be determined, the sulci between the costal and the marginal scutes followed
pretty closely the sutures between the costal and the peripheral plates. No sulci are found
crossing the two costal plates present. On the eighth and ninth peripherals a deeply imprest

DERMATEMYDID&. 229

sulcus runs an irregular course across the upper ends, 65 mm. above the free border, then rises
and does not appear on the more posterior peripherals and pygal.

Mr. L. M. Lambe, of the Canadian Geological Survey, describes (op. cit., p. 40) some
conical, rugose bones which he believes belonged on the tail of this species.

Cope speaks of the dermal sulci as being deeply imprest. This is true of many of them,
especially of those of such costals as are known—the anterior plastral sulci, and some others;
but many are extremely narrow and shallow, and are difficult to follow as they wander over
and among the pits and ridges of the sculpture.

Compsemys ogmius was based on a fragment of what Cope regarded as a costal plate and
on a fragment of the plastron. These were never figured. They were obtained in the Judith
River beds by Dr. G. M. Dawson, of the British Boundary Survey, at a point along the Milk
River, near the boundary between Assiniboia and Alberta. These fragments are now at
Ottawa. An examination of the bone identified as part of a costal shows that it is really a part
of a bridge peripheral, and that it possibly belongs to Basilemys variolosa. The fragment is
exceedingly poor. It is only §5 mm. square and shows only a small area of the sculpture, the
remainder having been weathered off. Where shown, the ornamentation is obscure. The
piece of plastron 1s g3 mm. long, 35 mm. wide, and 12 mm. thick. The sculpture is nearly
effaced by weathering. While these bones may belong to B. variolosa, there is too much
doubt regarding them to permit us to adopt for them and the last-named species the earlier
name ogmius. Even if ogmius were a species distinct from varvolosus, it is doubtful whether
new materials could be identified by means of the type.

Cope’s assignment of the species described above to the genus Compsemys is an error.
The sculpture of the latter is of a very different character and there were probably infra-
marginals.

Fics. 288 anp 289.—Bastlemys stnuosa. Carapace and plastron. 1).

288. Carapace. 289. Plastron.

Basilemys sinuosa Riggs.
Plate 33, figs. 1, 2; text-figs. 288, 289.
Basilemys sinuosus, Riccs, Pubs. Field Columb. Mus., Geol. ser., 11, 1906, p. 249, plates Ixxvi, Ixxvu.

The fine specimen on which this species is founded was collected by Dr. E. S. Riggs, ot
Field Natural History Museum, Chicago. It was secured in the Laramie deposits of Chalk
Buttes, near Powderville, Custer County, Montana. With it were found bones of Triceratops,
Trachodon, and other characteristic Laramie fossils. The shell is nearly complete. Of the
plastron nothing is missing, except some parts of the bridge peripherals. Of the carapace

230 FOSSIL TURTLES OF NORTH AMERICA.

some portions of the neurals and the contiguous borders of the ght third and fourth costal
plates are wanting.

The carapace (plate 33; text-fg. 288) is deprest, due probably in some degree to pressure.
The anterior border is excavated over the neck, broadly rounded behind. Behind the ingui-
nal notches the borders are somewhat flared upward.

The length of the carapace from the bottom of the notch in front to the rear, measured in
a straight line, is 715 mm.; the breadth is very close to 585 mm. The anterior notch is 22 mm.
deep. The free border in this notch is about 25 mm. thick. On each side of the midline the
border thins rapidly and soon forms an acute edge, which continues to the axillary notch.
Behind the inguinal notches the free edges are acute.

The nuchal bone measures 85 mm. along the midline; its width is 145 mm. The first
neural was about 80 mm. long and 60 mm. wide behind. The second neural is oval, 68 mm.
long, 40 mm. wide. The third is broadest in front, 80 mm. long, 50 mm. wide. The fourth
neural is wanting; the fifth 1s defective. The sixth is 70 mm. long, 50 mm. wide. The seventh
and eighth are small and irregular in form. There is a small first suprapygal. The second
is bifurcate, as in Testudo. It measures along the midline 60 mm.; its lateral extent is 170
mm. The third suprapygal is 72 mm. along the midline and 135
mm. wide. The pygal bone is 52 mm. high and 75 mm. wide.
The tenth peripheral bone is 85 mm. along the free border and
102 mm. high. There are 11 pairs of peripherals.

Vertebral. Length. Width.

z 190 se The nuchal scute is small, about 25 mm. long and 15 mm.
2 145 100 o = . .

z sae 168 wide. The first vertebral scute is unsymmetrical. On the left
4 125 go side the anterior border extends 100 mm. from the midline; on the
3) 140 235

right side apparently only 60 mm. The left appears to be the nor-
mal side. The table herewith gives dimensions of the vertebrals.

It will be observed that, with the exception of the first and the last, the vertebrals are
considerably longer than wide. The costal scutes are large. The second has a longitudinal
extent of 160 mm. and a height of 240 mm. They extend far below the costo-peripheral
sutures. Of the marginal scutes there are 12 pairs. The second extends from the free border
42 mm. to the first vertebral scute. The third has a height of 60 mm.; the ninth a height of
60 mm.; the twelfth, a height of 75 mm.

On the lower side of the first and second peripherals the portion covered by the horny
scutes is about 50 mm. wide. Toward the nuchal bone and the axillary notch this narrows
greatly. Behind the inguinal notches the horn-covered surface on the lower side of the periph-
erals is about 45 mm. wide to the midline behind.

The plastron (plate 33; text-fig. 289) has a total length of 660 mm. The lobes are short,
the bridges wide. The length of the anterior lobe, to a line joining the bottoms of the axillary
notches, is 160 mm. The breadth, taken from the inner border of one axillary notch to the
other, is 330 mm.

Anteriorly the lobe ends in a beak as prominent as that of many species of Testudo.
From the anterior end of one gulo-humeral sulcus to the other, the width is 95 mm. The beak
extends 42 mm. in front of this. On the lower surface the beak is nearly flat, but toward the
front it develops a broad median channel. Laterally the borders of the beak, like those of
the whole anterior lobe, are subacute. From this subacute edge the bone rises abruptly and
nearly perpendicularly, finally rounding off into the convex upper surface of the beak. The
maximum thickness of the bone is 50 mm. On the upper side of the beak the ornamented
surface extends back about 55 mm. From the sides of the beak this sculptured surface narrows
toward the axillary notch. At the junction of the epiplastron with the hyoplastron the bone
is 35 mm. thick. The median portions of the anterior lobe are much thinner.

The entoplastron is short but very wide. Its fore-and-aft extent is 110 mm., the breadth,
145 mm. The form is shown in the figures.

The bridges are about 370 mm. wide. The hinder lobe has a length of 145 mm. and a
width of 300 mm. At the borders, for some distance behind the inguinal notches, the bone
turns abruptly and perpendicularly upward to the summit of a ridge running backward from
the inguinal notch. From the summit of this ridge the bone slopes rapidly downward to the
central portion of the lobe. At the hypoxiphiplastral suture the ridge is 50 mm. above the

a

DERMATEMYDID&. 231

lower surface of the plastron; at the femoro-anal sulcus, only 20 mm. On the upper surface
of each xiphiplastron is a scar for the pubis. This scar is 55 mm. long and 30 mm. wide.
The inner borders of the two are 100 mm. apart. The hinder end of the lobe is truncated
and bent upward as the hinder extremity is approacht.

The median portion of the plastron is very concaye, a condition which appears to indicate
that the individual was a male.

On some parts of the plastron the sulci bounding the epidermal scutes are very distinct;
in others they are obscure, but determinable. They consist of very narrow, thread-like grooves,
some of which pursue their course at the bottoms of broad channels, while others keep on
the level of the general surface. The median sulcus runs an extremely irregular course, being
first on one side of the midline, then on the other. The intergulars occupy the whole lowe:
surface of the lip, extending backward 100 mm. along the midline. The gulars meet at the
midline a distance of 35 mm. Their posterior borders run parallel with the anterior.

At the midline the humerals join for a distance of only 8 mm.; but from this they expand
rapidly and their outer ends reach about 60 mm. behind the axillary notch. The pectoral
scutes are, fore and aft, extremely broad, meeting along the midline a distance of 195 mm.
Their outer ends are only 30 mm. wide. The abdominal scutes extend along the midline 160
mm., while their outer borders are 240 mm. long. The length of the femorals at the midline
may be taken as go mm.; that of the anals as the same.

The scutes covering the bridge are separated from the plastral scutes just described by a
nearly straight sulcus running from the axillary to the inguinal notch. Of these scutes the
most anterior and the posterior alone appear to represent the inframarginal series. The
others are bridge marginals. Of these, one, the sixth marginal, has become greatly expanded
at the abdominal end; the other marginals are greatly narrowed at their lower ends. ‘This
absence of a series of inframarginals is remarkable in this family.

The sculpture of this species resembles closely that of its predecessor, B. variolosa. The
carapace and the plastron are both rough with sharp elevations, which are usually triangular
pyramids. These are mostly arranged in rows, of which three or four are spanned by a line
to mm. long.

The present species differs from B. variolosa in various points. The gulars of the Judith
River species are crowded far from the median line; in B. sinuosa they are in contact with
each other. The pectoral scutes of B. sinuosa extend backward nearer to the hyohypoplastral
suture than they do in B. varrolosa. The hinder extremity of the plastron of B. sinuosa is trun-
cated, bent upward somewhat, and has its borders acute; that of B. variolosa is broadly
rounded, flat, and the borders are thick and obtuse. From some peripherals present, belonging
to the type of B. variolosa, it appears that the sculptured, horn-covered surfaces on the under
side of the peripherals are considerably broader than they are in B. smmuosa. On the eighth
peripheral this surface is 70 mm. wide; in B. sinuosa it is only 50 mm. wide. The plastron
of the type of B. variolosa is only about 10 mm. longer than that of B. snuosa Riggs.

A fragment of the epiplastral lip of what is regarded as this species was found by Mr.
Barnum Brown of the American Museum, on Hell Creek, Dawson County, Montana.

Basilemys imbricaria (Cope).
Plate 32, figs. 5, 6, 7; text-figs. 290, 291.

Compsemys imbricartus, Cope, Proc. Acad. Nat. Sci. Phila. 1876, p. 257; Bull. U. S. Geol. Surv., m1,
EH By SIS an er ox

Basilemys imbricarius, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445.—Hatcuer, Bull. U.S.
Geol. Surv. No. 257, 1995, p- 77-

Adocus (Bastlemys) tmbricartus, OsBoRN, Cont. Canad. Palzont., 111 (4to), 1902, p. 16.

This species was founded by Professor Cope on very unsatisfactory materials. The type,
to which only three fragments (No. 6102 of the American Museum of Natural History) can be
referred with any certainty, was found in the Cope collection mingled with fragments of two
or three other species. The identified bones are here figured of the natural size (plate 32
figs. 5, 6, 7). All are probably portions of costal plates. The larger piece is traverst by a
narrow and sharply imprest sulcus, and appears to be the fragment mentioned by Cope as

232 FOSSIL TURTLES OF NORTH AMERICA. °

having the direction of the ridges of sculpture running at nght angles with the sulcus. The
inner ures of the bone is removed, so that the dhichaess oF the fragment can not be deter-
mined. It was more than 6 mm.

The piece of medium size has a sutural edge along one side. ‘The thickness is 6 mm.
where thickest, 5 mm. where thinnest; and it may be the fragment whose measurement Cope
gave. The smallest piece of bone is only 3 mm. thick.

This species is distinguisht especially by its sculpture. It is thus described by Cope:

It consists, in the Compsemys imbricartus, of excavations bounded on the sides by a short ridge
each, which [excavations] alternate with each other. Thus each bounding ridge terminates abruptly
at the fundus of one of the fosse, while the other end of the fossa rises and contracts into another
ridge. The result is precisely that seen in the interior sculpture of Saracenic domes and niches,
and is one quite unique among tortoises. The direction of the ridges is at right angles to the costal
dermal sutures.

Cope states that three of the fossae measure in length 6.5 mm. and crosswise, 5mm. Inthe
case of the largest of the three fragments of the type three foss taken together measure 7 mm.
and crosswise, 6 mm.

While this style of ornamentation appears to be very peculiar, something scarcely dis-
tinguishable in pattern may be seen here and there on the carapace of B. variolosa, and for
that reason the present species has been referred to Basilemys. In fact Cope has jabeled as
Compsemys imbricaria some fragments the sculpture of which appears quite identical with that
of B. vartolosa. With these eter fragments, however, there is what seems to be the thickened
rim of the front of the carapace (fig. 290, No. 6100 A. M. N. H.), and this is plainly different
from that of B. variolosa. Evidently there is another species occurring with B. variolosa,
related to it, but differing in important characters. For this species we may for the present
retain the name Basilemys imbricarta.

The remains of this form were collected in 1876, in the Judith River beds of Montana, by
Mr. Charles H. Sternberg.

Fig. 290 represents a section across the supposed anterior peripheral, No. 6100 A. M. N. H.
The part of this peripheral which joins the costal
is missing. On the under side it appears to extend
pecan to the line reacht by the soft skin, a
distance of 27 mm. from the free border. The
extreme thickness of the fragment is 16mm. The
upper surface is slightly convex; the lower surface
strongly so. The ornamentation is coarse, there

Sections. 3. No. 6101 A. M.N.H. being 3 fossein g mm. This peripheral differs from
2go. Section across peripheral. one in the same region of B. variolosa in having
291. Section across border of xiphiplastron. C : -
the sculptured surface on the under side of the bone
much narrower from the free edge to the skin line in proportion to the thickness of the bone.

It is to be noted that these ‘coarsely sculptured fragments possibly do not belong to B.
imbricaria.

In the Cope collection there is another fragment (No. 6101) which possesses a sculpture
like that of the specimens just described, and this is evidently a portion of the left xiphiplastron
(fig. 291). There are 3 fosse in 8 mm. It differs from that of B. varrolosa in having a sharp
border separating the lower surface from the surface which looks outward and upward. In
B. vartolosa the lower surface of the hinder lobe rounds gradually into the upper surface.

Professor Cope has labeled as Compsemys aye) aria other specimens from the Judith
River beds which have a sculpture similar in pattern but much more delicate. In these

(No. 6103 A. M. N. H.), some of them fragments of costals, there are 4 fossa in a line 5 mm.
long. The scutal sulci are thread-like. Orier fragments, peripherals from the bridge perhaps,
cae similar ornamentation but the sulci are very broad. It seems very probable that the
fragments here described belong to more than one species, but the discovery of additional and
much better materials will be required in order to determine the structure and generic position
of Cope’s Compsemys imbricaria.

201.
Fics. 290 AND 291.—Basilemys imbricarta.

if

ha

DERMATEMYDID&. 23 3
Genus COMPSEMYS Leidy.

Little-known turtles belonging probably to the Dermatemydidz. Free surfaces of the
bones of carapace and plastron ornamented with small, close-set, enameled tubercles which
produce the appearance of shagreen. Neurals hexagonal, with the broader end forward.
Costals without distal prolongations into the peripherals. Sulci thread-like. The plastron
suturally articulated with the contiguous peripherals and sending up axillary and inguinal
buttresses to the costals. No evidenees of mesoplastra. Inframarginal scutes probably on
the bridges. Vertebral scutes not greatly expanded. -

Type: Compsemys victus Leidy.

The genus Compsemys was establisht in 1856 by Professor Leidy, to receive the scanty
remains which he named Compsemys victus. Later discoveries have added little to our
knowledge regarding the genus; altho it is evident that it is represented over a wide area of
territory and thru a eoieidceble range of deposits, having been reported from levels rang-
ing from the Judith River beds to the Denver The only characterization that Leidy gave to
his genus is exprest in the following words:

The peculiarity of the specimens which has led to the proposal of the genus consists in their exterior
surface being closely studded with uniform granular tubercles, which give to them a shagreened appear-
ance, quite different from anything I have had the opportunity of seeing in other turtles.

At a later time Professor Cope assigned to Compsemys Leidy’s Emys obscurus and after-
wards returned it to Emmys. At the same time he referred to Compsemys his own Adocus
lineolatus without explanation. These two species undoubtedly belong elsewhere. The
same verdict must be pronounct regarding the three species described by Cope in 1875 and
1876, from the Judith River beds, ane called by him Compsemys ogmius, C. imbricurius,
and C. vartolosus. In 1877 Cope described his Compse mys plicatula from the Jurassic of
Colorado, and there can be little doubt that his generic reference of the specimen was based on
the similarity of the sculpture to Leidy’s species. Especially since Dr. Baur’s description of
Cope’s C. plicatula it has been regarded as representing the characters of Compsemys. How-

ever, there can be no doubt that c phieatala belongs to a wholly different genus from wrcta, and

to another superfamily. Most of the references in scientific literature to the genus Compsemys
(for which see the writer’s Bibliography and Catalogue of Fossil Vertebrata N. A., 1902,
p- 437) are to the genus as typified by C. plicatula and are therefore to be tranaferied to
Glyptops. When Baur (Proc. Acad. Nat. Sci. Phila. 1891, p. 412) states that the Laramie
forms of Compsemys show all the characters of the Jurassic form he seems to have had in mind
Cope’s Compsemys variolosa, but this certainly has no mesoplastron.

So far as at present known the only species to be assigned with any certainty to this genus
is the type, C. victa. It is probable that when the Foran that has been reported to occur in
the Judith River beds is better known it will prove to be a second species.

Compsemys victa Leidy.
Plate 34, figs. 2, 3; text-figs. 292-295.

Compsemys victus, Leipy, Proc. Acad. Nat. Sci. Phila. 1856, p. 312; Trans. Amer. Philos. Soc., x1,
1860, p. 152, plate vi, figs. 5-7.—Coprr, Trans. Amer. Philos. Soc., x1v, 1869, p. 124; Seventh Ann.
Report U. S. Geol. Surv. Terrs., 1873 (1874), p- 454; Bull. U.S. Geol. Surv., 1, No. 2, 1874, p. 303
Vert. Cret. Form. West, 1875, pp. 91, 261, plate vi, figs. 15,16; ?Brit. N. A. Bound. Comm. Report,
1875, pp- 333, 330; ?Bull. U. S. Geol. Surv., 111, 1877, p. 573.— ?Cross, Monogr. U. S. Geol. Surv.,
XXvII, 1896, p. 227.—?Marsu, Monogr. U.S. Geol. Surv., xxvu, 1897, p. 527.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 437-

Professor Leidy’s type of the present species consisted of a neural; a considerable portion
of a costal, regarded as a fifth; and a fragment of the eighth costal. These are now in the
U.S. National Museum and bear the aimier g6o. They were secured in deposits of probably
Laramie age, at Long Lake, North Dakota. The species was afterward reported by Cope
from supposed Laramie deposits in Colorado, now regarded as Arapahoe or Denver (Cross,
op. cit., pp. 227, 244), and with doubt from Judith Rin er beds (Cope’s Fort Union) and from

234 FOSSIL TURTLES OF NORTH AMERICA.

beds of the same period in the region about Milk River, British America. As the Judith
River beds are now known to be much lower in the geological scale than the Laramie it is
probable that a distinct species is there included. The Arapahoe and Denver beds being prob-
ably above the Laramie, it is not improbable that the remains reported from that horizon by
Cope and Marsh belong to a third species of the genus.

Leidy’s type an dicated a turtle whose carapace had a length of about 365 mm. The neural,
regarded as the fourth, was 26 mm. long and 27 mm. adel The costal plate believed to be
che fifth, was 28 mm. wide at the middle OF the length. It is rather strongly archt, showing that
the shell was not deprest. This costal had a thickness of 7 mm. where it joined the neurals.
It is crost at the proximal end by the costo-vertebral ice from which proceeds the sulcus
that separated the third and fourth vertebral scutes. The position of the longitudinal sulcus
indicates that the vertebrals had a width of about 65 mm. Leidy’s estimate that they were
2 inches wide 1s too small.

The specimens figured by Cope in his Vertebrata of the Cretaceous Formations of the West,
plate vi, figs. 15, 16, were collected in 1873, in northeastern Colorado. No statement is made as
to the exact locality, but they probably came from the Denver beds in the region about Bijou
Creek. We can not be really certain that they belong to Leidy’s species. Cope’s fig. 16
represents a posterior peripheral, apparently the ninth of the left side, with the sulcus between
the third and fourth costals running down its anterior half. The bone is 39 mm. high, 32 mm.
wide at the free border, and g mm. thick at the costal border. There is no pit for the rib-end.
The bone thins to an acute free border. The upper surface is only slightly concave. The
sculpture resembles that of the
type of the species. A remarkable
feature of this bone is the low
position of the costo-marginal
sulcus. [his runs much nearer
the free than to the costal border.

Fics. 292-295. —Compsemys victa.
Fragments of shell. Xj.

292. Portion of right costal. No. 6096
A. M.N.H.

293. First right peripheral. No. 1085
A.M.N.H.

294. Fragment of bridge peripheral. No.
998 A. M. N. H.

295. Portion of right hyoplastron. No.
1o15 A. M.N.H.

295:

aK

/

{

eee

In Gly ptops plicatulus, as is usual in turtles, it runs nearer the costal border. In the periph-
eral here described the scute-covered surface on the inferior side of the bone extends to within
15 mm. of the costal border. The granulation is finer than on the upper side of the bone.
The other fragment figured by Cope furnishes little additional information.

A right eighth costal, No. 6096 of the American Museum of Natural History, collected by
Mr. J. C. Isaac, i in 1877, in the Laramie beds, on Lance Creek, Wyoming, was at least 40 mm.
wide and from 5 mm. to 8 mm. thick (plate 34, fig. 3; text-fig. 292). The proximal portion and

a part of the hinder border are broken away. On the lower surface there is the base of a
seronely developt rib-head; but there is no ridge corresponding to the rib, nor any projecting
distal end of the rib, such as we find in Glypiops. Near the hinder border of the bone is a sulcus,
that separating the fourth costal scute from the fifth vertebral. On the peripheral border are
two loops of a sulcus, one narrow, the other wider. These appear to have proceeded from the
peripheral; but as the peripheral figured by Cope shows the costo- marginal sulci to have run
low down on the peripherals, the presence of these loops on the costal is at present inexplicable.
Similar irregularly meandering sulci are seen on other bones. The oblique hinder sutural edge
of the costal probably articulated with the eleventh peripheral and with the suprapygal. The
fourth costal scute may have occupied a portion of the suprapygal, as it does in Kinosternon.
In the U.S. National Museum there is a neural, the second or fourth, which was collected by

Mr. J. B. Hatcher, on Lance Creek, Wyoming.

DERMATEMYDID. 235

In 1902, Mr. Barnum Brown, of the American Museum, collected a few fragments of this
species in Laramie beds on Hell Creek, Dawson County, Wyoming. One is the first right
peripheral (fig. 293). The individual (No. 1085 A. M. N. H.) was a relatively small one. The
fore-and-aft extent of the bone is 23 mm., and the thickness of the hinder border, 5mm. The
free edge is acute. The first marginal scute is only 5 mm. antero-posteriorly where it joins the
second. The latter widens to g mm. at the suture between the first and the second peripherals.
On the under side of the bone the sculptured, horn-covered surface is about 7 mm. wide at
the suture with the second peripheral, but toward the nuchal it narrows to 3-5 mm.

Of the bridge peripherals there is a portion of one in the American Museum, No. 908,
collected by Mr. Brown in 1900, in Laramie deposits of Wyoming, about 40 miles west of
Edgemont, South Dakota. This fragment (fig. 294) shows that there was no sharp carina
above the bridge, but an obtuse, rounded ridge. Fig. 2, plate 34, represents what is probably
the distal end of the fourth costal. Besides the descending sulcus there are again seen some
irregular loops coming up from the contiguous peripherals.

Of the plastron there are only fragments known. Fig. 295 represents what appears to
be the left outer extremity of the hyoplastron of a young individual from Hell Creek, No.
1o15 A.M.N.H. The zigzag sutural border is for articulation with the peripherals, appar-
ently the third, fourth, and fifth. This border is only 2 mm. thick. The longitudinal sulcus
is that which passes from the axillary to the inguinal notch. The short branch on the right
appears to be the pectoro-abdominal. The three scute areas on the left may be inframarginals
or they may be marginals. If inframarginals, they extend wholly beyond the plastral bones.
On the inner side of this bone is seen a portion of the strongly developt buttress which rose to
the border of a costal, probably the first. It is possible that the bone here described really
belongs to the inguinal region. In either case there is indicated the absence of a mesoplastron.
On the mesoplastron of Glyptops and of Baéna there is one inframarginal. There are three
on the bone above described. There would thus be seven probably on each bridge.

It will be seen from the descriptions given here of this species that it is very imperfectly
known. Additional materials ought to be sought by collectors. Evidently it was a species
that attained a considerable size and which, when grown, possest a thick shell. Its sculptured
upper and lower surfaces must have rendered it a beautiful animal.

Compsemys? obscura (Leidy).
Plate 34, fig. 4.

Emys obscurus, Leipy, Proc. Acad. Nat. Sci. Phila. 1856, p. 312; Trans. Amer. Philos. Soc., x1, 1860,

p- 153, plate xi, fig. 4.—Cope, Bull. U. S. Geol. and Geog. Surv. Terrs., 111, 1877, p. 573-
Compsemys obscurus, Corr, Trans. Amer. Philos. Soc., 1869, xtv, p. 124; Bull. U. S. Geol. and Geog.

Surv. Terrs, 1, No. 2, 1874, p. 30; Vert. Cret. Form. West, 1875, p. 261.—Hay, Bibliog. and Cat.
Foss. Vert. N. A., 1902, p. 437

This species is retained here under the genus Compsemys because it has already been
placed there by Cope and Leidy and because we do not know where else to place it. There is
little evidence that it is closely related to Compsemys victa and there is no probability that
it is an Emys, in the modern acceptation of that term.

Leidy’s type of his Emys obscurus was found by Dr. F. V. Hayden at Long Lake, in the
present state of North Dakota, in deposits that are now regarded as belonging to the Laramie.
The writer does not know where the type is to be found. The part figured and described by
Leidy is a portion of a costal plate, extending from the costo-vertebral sulcus to the costo-
peripheral suture. This costal is 33 mm. wide, 60 mm. long from the sulcus to the distal end,
and little more than 3 mm. thick. The surface is described by Leidy as being smooth. His
figure shows that the sutural borders were markt by fine striations at right angles to the
sutures.

In the American Museum of Natural History there are the proximal ends of 2 costals
which were found by Mr. Barnum Brown, in 1902, in Laramie deposits, on Hell Creek,
Dawson County, Montana. These are identified as belonging to the species here described.
One of these fragments (plate 34, fig. 4) appears to belong to the second left costal. It is 31

236 FOSSIL TURTLES OF NORTH AMERICA.

mm. wide, 6 mm. thick at the articulation with the neural, and 3 mm. at the sutural border,
just beyond the costo-vertebral sulcus. The proximal end is occupied by one of the vertebral
scutes. Near the posterior border of the bone the scute overlapt the bone about 20 mm.
The sulci are rather narrow. A broad band of fine striations borders the sutures, the striations
being at right angles with the latter. The remainder of the surface is markt by delicate ridges
and pits appreciable only under a lens.

The other fragment mentioned belonged to the third or the fifth costal of one side or the
other; and it bears a portion of the sulcus between two vertebral scutes. This sulcus extends
along the bone a distance of 27 mm. without joining the costo-vertebral sulcus ; so that we
may conclude that the hinder vertebral scutes were somewhat wider than the anterior.

This species is included by Cope in his list of Judith River fossils, but the writer knows
of no specimens that confirm the statement.

Genus ADOCUS Cope.

Carapace firmly articulated to plastron by sutures between the bridge peripherals and the
hyoplastrals and hy poplastrals, and by axillary and inguinal buttresses. “Heads of ribs, except
that of first costal bone, vestigial. Free borders of the peripherals acute. Scutes of the carapace
normal; most of the marginals rising and overlapping the lower ends of the costal bones.
Lobes of the plastron somewhat reduced; the hinder not notcht. Plastral scutes 7 pairs; the
intergulars excluding the gulars from contact on the midline. Inframarginals present.

Type: Emys beatus Leidy.

The genus ddocus, as here defined, is at present known only from Upper Cretaceous
species; aud: except 4. Iineolatus, doubtfully referred to the genus, all are from the Upper
Cretaceous greensand of the eastern United States. Adocus may be regarded as the least
modified of the Dermatemydide. Its advanct characters appear to be found in the slightly
reduced number of neurals, one or two of the most posterior probably being usually missing;
in the developt buttresses; in the aborted rib-heads; and in the reduced gular scutes. Prim-
itive characters are found in the possession of seven pairs of plastral scutes and the unin-
terrupted series of inframarginals.

The following key may be of some value in separating the species:

Key to Species oF Apocus.

A. Species of the Rocky mountain region; not well known : _ ae _.. lineolatus
AA. Species of eastern United States region.
a. Hinder lobe of plastron narrowed behind.
b. Entoplastron wide; nearly equal to length of the suture between the hyoplastrals beatus
bb. Entoplastron narrow; width nearly twice in the hyoplastral suture........... pravus
aa. Hinder lobe broad behind; rounded or truncated.
c. Gulo-humeral sulcus close to or crossing the entoplastron.

d. Hinder lobe truncated behind; the length between three-fifths and
four-fifths the width at the base... . . punctatus

dd. Hinder lobe broadly rounded; its length he ‘Baths 4he width at the
base; gulo- -humeral sulcus just in contact with the entoplastron. . syntheticus

ddd. Hinder lobe broadly rounded; its length four-fifths the width at base;
gulo-humeral sulcus well forward on entoplastron........... : lacer
cc. Gulo-humeral sulcus falling considerably behind the entoplastron........ agilts

Adocus punctatus Marsh.
Plate 34, figs. 6, 7; plate 35, figs. 1, 2; text-figs. 296-298.

Adocus punctatus, Marsu, Amer. Jour. Sci. (3), XL, 1890, p. 178, plate vii, fig. 3—WreLanD, Amer.
Jour. Sci. (4), Xvit, 1904, p. 112, plates i-v, text-figs. 1, 2.

Adocus beatus, Baur, Proc. Acad. Nat. Sci., 1891, p. 428.—Hay, Bibliog. and Cat. Foss. Vert. N. A.,
1902, p. 444.

At the present time this species is represented by better materials than any other of
the genus, and for that reason it is here described first of all the species of Adocus. The

DERMATEMYDID&. 237

type belongs to the Marsh collection in Yale University Museum and presents the nearly
complete shell. It was obtained in the upper bed of Cretaceous marl at Hornerstown, Mon-
mouth County, New Jersey, in 1872. It has been restored and fully described by Dr. G. R.

ae Wieland, as cited in the synonymy. Dr.
Wieland’s figures are employed in the pres-
ent work to illustrate the structure.

The total length of the carapace (plate
35, fig. 1; text-fig. 296) ina straight line is
533 mm. The greatest width is 390 mm.
The form is that of an elongated oval,
broadest behind the middle, rounded in
front, more broadly rounded behind. Dr.
Wieland has called attention to a double
curvature along the sides. Possibly this
is due to slight distortion. From side to
side anteriorly the carapace is quite evenly
convex; posteriorly in the restoration it is
somewhat flattened. The hinder periph-
erals are flared somewhat upward, but the
front ones are not. The peripherals of the
free borders are thin and reduced to an
acute edge. In front of the axillary notch
the edges of the peripherals are somewhat
reverted, leaving a groove within the edges.
The nuchal bone is 70 mm. long on the
midline; 65 mm. wide on the free edge; 95
mm. where widest. There were 7 neurals,
of which all are present except the sixth.
Its form and dimensions are determinable
from the surrounding bones. The seventh
was not developt; the eighth is small. The
Fic. 296.—Adocus punctatus. Carapaceof type. X0.18. table below presents the dimensions of the
c.p.1,c. p.2,c. p.8, costal plates; m.s.1,m.s.12,marginal scutes; neurals.

nu. p, nuchal plate; per, 2, per, 11, peripheral bones; py, Most of the neurals are hexagonal,

pygal; spy, suprapygal; n.1, 2.6, neural bones. with the broader end forward. The first
has the broader end behind; the second is octagonal. The absence of the seventh neural
permitted the seventh pair of costals to meet in the midline. Those of the eighth pair also
meet in the midline in front of the eighth neural. The single suprapygal is octagonal, 70
mm. long and 110 mm. wide.

The peripherals are in general large. Their height, at right angles with the free border,
increases from the third to the ninth; the tenth has nearly the height of the ninth; the eleventh
is considerably smaller. The first peripheral extends along the free border 63 mm.; and
from this to the first costal, 65 mm. The second is slightly smaller in both dimensions. The
third occupies 50 mm. of the free border and is 65 mm. high. The ninth is 75 mm. along the
free edge and 103 mm. high. The eleventh occupies 62 mm. of the free border and rises

toward the suprapygal 70 mm. The pygal measures 65 mm.
along the free edge and is 60 mm. high.
Neural. | Length. = Width. The sulci are usually rather narrow and shallow. Those
ee a on the front are somewhat deeper and broader. The table on
page 238 gives the dimensions of the vertebral scutes.

38
| ; 4 27 The costal and the marginal scutes are of unusual confor-
3 Ss? pie mation. The anterior marginals are mostly small; the lateral and
i 38 posterior remarkably large. As a result, most of the costals are
6 44 35 considerably reduced in area. The nuchal scute is 16 mm. long
aa > and only 6 mm. wide. From this the marginals continue to rise

slowly above the free border to the hinder end of fourth, which

238 FOSSIL TURTLES OF NORTH AMERICA.

has a height of 45 mm. All of these lie wholly on the peripherals. The fifth marginal
suddenly rises to a height of 100 mm. and overlaps the lower ends of the second and third
costal bones. The ninth marginal has a height of 145 mm. The next two are only slightly
lower. The supracaudal scutes meet along the midline a dis-
tance of 97 mm. The costal scutes diminish in size from the first

Mer aaeanceal Ae ota to the last. The latter has a fore-and-aft length of 80 mm. and a
width of 55 mm.

: mee as The plastron (plate 35, fig. 2; text-fig. 297), as in other spe-

3 100 85 cies of the genus, is relatively small. Both the anterior and the

4 os a posterior lobes are truncated. The total length is 355 mm. The

anterior lobe has a length of 80 mm. and a width of 175 mm. at
the base. The truncated anterior end is 85 mm. wide. The
entoplastron is 50 mm. long and 70 mm. wide. The bridges are 140 mm. wide. The posterior
lobe is 130 mm. long and 175 mm. wide at the base. The posterior truncated end is about
80 mm. wide. The free borders of both lobes are acute. The plastron articulates with the
peripherals by means of sutures; and axillary and inguinal buttresses rise nearly to the

Fic. 297.—Adocus punctatus. Lower side of shell. 0.16.

ab, abdominal scute; an, anal scute; c. p.1, c. p.2, etc., costal plates; ent, entoplastron; ep7, epiplastron; fem,
femoral scute; g, gular scute; ium, humeral scute; hyo, hyoplastron; hypo, hypoplastron; ig, intergular
scute ; infm, inframarginal scutes; nu, nuchal bone; pec, pectoral scute; per. 3, per. 8, peripheral bones;
py, pygal; spy, suprapygal; x/ph, xiphiplastron.
lower ends of the costal bones. Plate 34, fig. 5, from a drawing made for Dr. Baur, repre-
sents the upper side of the xiphiplastral Bones There are very distinct curved depressions
for the pubic bones, but there was no sutural articulation of the latter bones with the plastron.
The sutures between the various bones of the plastron are somewhat irregular, as is shown
in the figures. The sulci are still more irregular, especially the longitudinal cane All the
sulci are narrow and shallow. The intergulars have pushed the eulars away from contact at
the midline, and neither gulars nor intergulars overlap the entoplastron. The humerals occupy
42 mm. of the midline. The pectorals measure 40 mm. along the midline and they overlap the
hinder end of the entoplastron. The abdominals, the femorals, and the anals respectively
occupy 88 mm., 82 mm., and 72 mm. of the midline. There are 3 inframarginals on each of
the bridges.

DERMATEMYDID&. 239

Both the carapace and the plastron of this species are ornamented with rows of shallow
pits. On the carapace these pits are arranged mostly in rows that run obliquely across the
costal, neural, and peripheral bones. On the median parts of
the plastron the pits are less distinct, but still evidently present.

The relationships of this species to 4. beatus are discust
under the latter species. Figs. 298 and 299, taken from Dr. Wie-
land, represent the position of the sulci on the first left peripheral
of A. punctatus and A. beatus. From these it appears that the
width of the first vertebral scutes was considerably greater in the
former than in Leidy’s species; also that the free border of the
bone itself was wider in Marsh’s species than in Leidy’s. As
regards the width of the front of the vertebral scute, there is
liable to be variation in it, and not much stress can be placed
on it. The specimen in the Philadelphia / cademy which the
writer is obliged to refer to 4. lacer differs from the type in the
arrangement of the scutes on the first peripheral.

Fic. 298.—Adocus punctatus.
First left peripheral of type.
<4. After Wieland.

Adocus beatus (Leidy).
Plate 34, figs. 6, 7; text-figs. 299-301.

Emys beatus, Lerpy, Cret. Reptiles, U.S., in Smithson. Cont. Knowl., x1v, 1865, pp. 107, 119, plate xviii,
figs. I—3.

Adocus beatus, Cope, Proc. Acad. Nat. Sci. Phila. 1868, p. 235; Cook’s Geol. New Jersey, 1868 (1869),
p- 734; Ext. Batrach., Reptilia, Aves N. A., 1869, pp. 129, 233; Proc. Amer. Philos. Soc., x1,
1870, pp. 296, 547; Ibid xm, 1871, p. 43; Vert. Cret. Form. West, 1875, p. 262.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 444.

The type of the present species consists of the anterior half of the first neural, the third and
fourth neurals complete, the proximal portions of the second and third costals, the proximal
end of the left first costal, and the left first peripheral. These were obtained in the Cretaceous
greensand at Mullica Hill, Gloucester County, New Jersey, and were presented to the Academy
of Natural Science of Philadelphia, by William M. Gabb. These remains are yet in the
Academy’s collection. ;

In 1869 Professor Cope, as cited, identified as belonging to this species a plastron and
some portions of the carapace which had been found in the greensand at Medford, New Jersey.
These bones are now in the Cope collection at the American Museum of Natural History,
at New York. A figure of this plastron is here presented (plate 34, fig. 6). Besides the
greater part of the plastron there are present fragments of several costals, and some anterior
peripherals.

In 1890 Professor O. C. Marsh (Amer. Jour. Sci., xt, p. 178) described 4. punctatus.
Afterwards Dr. Baur (Proc. Acad. Nat. Sci. Phila. 1891, p. 428) affirmed that this species
is identical with Leidy’s 4. beatus. Now, a comparison of Cope’s specimen with the type of 4.
punctatus shows that they are without doubt of different species. At the same time, it is perhaps
impossible to point out characters which will enable us to separate either Cope’s or Marsh’s
specimens from Leidy’s imperfect type. In such a case we must do one of three things—
reject Leidy’s species and its name, because of its ambiguous characters, giving a new name to
Cope’s specimen and retaining Marsh’s specific name; accept Baur’s conclusion, reducing
Marsh’s name to synonymy and renaming the Cope specimen; or accept Cope’s determination
and thereby avoid any new names. Cope’s turtle having come from the same region and level,
and having been first determined as A. beatus, it appears to the writer that the last of the three
courses is the best to follow. The principal respect in which the Medford specimen differs
from Leidy’s type is in the thickness of the first peripheral. In Leidy’s specimen (figs. 299,
300) this is only 15 mm. thick, while that of Cope’s is 20 mm. This does not, however, decide
the question in favor of Baur’s position, for the type of 4. punctatus also has this bone 20 mm.
thick. It is not at all improbable that the shell was thicker in some individuals than in others.
Fig. 300 represents the same bone of Leidy’s type, as the bone appears from below, showing an
excavation for a process from the nuchal.

240 FOSSIL TURTLES OF NORTH AMERICA.

Marsh’s type of 4. punctatus and the Medford turtle have the posterior plastral lobes of
the same width. The length of the whole plastron of 4. punctatus is 353 mm.; that of che
Medford specimen about 420 mm. The hinder lobe of the Medford specimen (plate 34, fig. 6)
is about 18 mm. longer than that of 4. punctatus. It is
also narrow and ends behind in a blunt point, while that
of A. punctatus is broad and the extremity is truncated.
Plate 34, fig. 7, represents the first peripheral of the right

Neural. Length. Width. Thickness.

71 31 7334 side and a part of the second, while text-fig. 301 repre-
m a j a Be sents the first left peripheral, all from the Medford speci-
3 ° 3 11.5 a = ns

i AG a ae men. In this the front of the first vertebral scute extends

somewhat beyond the end of the first marginal, while in
the type (fig. 299) it does not pass beyond the marginal.
We must, however, expect variations in this region, as there are variations in the same region
in living turtles. “The neurals of Leidy’s type have the dimensions given in the table herewith.
The thickness of the second neural is determined from the contiguous border of the costal.
The dimensions of the remains of costals are shown in the

ee ; table herewith.
| alg) ae oo The anterior neural is irregularly angular in front. The
second appears to have had the form of the same bone in the

I Be 6 type of 4. punctatus. The neurals of Leidy’s type are narrower
| i oe + : than those of 4. punctatus, but no great stress can be laid on the
3 2 :

difference. Only a fragment of the first costal is present. The
second costal articulated with the first, second, and third neurals,
just as in 4, punctatus. The first peripheral is 62 mm. antero-posteriorly, about 54 mm.
along the free margin, and 15 mm. thick. Fig. 299, from Wieland, shows the form of this bone
and the arrangement of the scutes on it. Phe weurale vandecostals-sher the regular and
shallow pitting exhibited by 4. punctatus Marsh.

The plastron of this species is known only from the specimen described by Cope (plate 34,
fig.6). The dimensions may be obtained from the comparative table on page 242. The total

299

Fics. 299-301.—Adocus beatus. Peripherals. >}. After Wieland.

299. First left peripheral of type.

300. First left peripheral of type, inferior surface, with section near suture with second peripheral.
Shows pit for process of nuchal. Upper surface of section toward right.

301. First left peripheral of Cope’s Medford specimen. No. 1138 A.M.N.H.

length may have been greater than that there given, since there is an interval wanting in the
hyoplastron, and since ee space has been allowed between the hyohypoplastral suture and
the inguinal notch than between this suture and the axillary notch. The bridge, as restored,
hasa wid of about 160 mm. The sides of the anterior lobe are only slightly convex; the front
broad and truncated, its width being about 95 mm. The anterior border is obtuse in section.

The hinder lobe is gradually reduted i in width backward and it ends obtusely. As Cope
remarkt, there is some asymmetry near the extremity, but this is individual. The free borders
of this lobe are subacute and a shallow groove runs parallel with the border on the upper side
of the bones.

The sulci of the plastron are rather obscure. That of the median line has not been repre-
sented in the figure. Probably it ran an irregular course, such as is seen in the other species.
The intergular scute is large and it trespasses on the margin of the entoplastron, separating

DERMATEMYDID#&. 241

widely the gulars. It was probably divided. The gulars are of rather peculiar form, extending
outward and backward toward the outer hinder angle of each epiplastron. The tinea
pectoral sulcus is so obscure that its course is uncertain, but it appears to run where indi-
cated in the figure. If this is correct, it did not cross any part of the entoplastron. The
pectoro- Dadowinal sulcus and the abdomino-femoral are distinct and as shown in the figure.
The course of the femoro-anal is as represented 1 in the figure. Of the inframarginal series,
only a small portion of one axillary scute is seen. The sculpture of the lower surface is hardly
to be determined, the result of weathering.

Both first peripherals are present (plate 34, fig. 7; text-fhg. 301). The antero-posterior
length is 65 mm.; the length along the free border, 64 mm.; along the hinder border, about
half as much. The thickness, as stated, is 20 mm. The upper surface of this bone is gently
convex; the lower surface is strongly convex antero-posteriorly. Close to the anterior Berlen
above there runs a shallow groove, so that the free border appears somewhat everted. On the
lower surface the sutural face for articulation with the nuchal is excavated for the short costi-
form process of the latter. “The same excavation appears in the first peripheral of Leidy’s
type of the species (fig. 300).

The marginal scutes did not extend upward quite half-way on the peripheral. Only a
fragment of the second peripheral is present. The form of the nuchal bone can only be inferred
from the sutural edges of the adjoining first peripherals. It seems probable that its right and
left sides made a sharper angle with each other than they do in 4. punctatus. It is extremely
probable that the front hordes of the nuchal measured between 65 and 70 mm. The front of
the first vertebral scute would then measure about 130 mm.

There are present fragments of various costals and bridge peripherals. ‘The proximal end
of a costal, probably the left third, has a width of 50 mm. and a thickness of rr mm. The
sulcus bounding laterally the two vertebral scutes of which it bears parts is distant 25 mm.
from the suture made with the neural. These vertebrals were then about 80 mm. wide, much
narrower than the first vertebral. The distal end of another costal is 60 mm. wide and 8 mm.
thick. It is crost by a sulcus which runs from 17 mm. to 45 mm. above the lower or distal end.
A bridge peripheral 1 is represented by the end which joined the costal. It is 57 mm. wide and
6 mm. thick. On its inner surface is a broad, shallow groove for the extremity of the rib, and
a portion of the rib extended beyond the border of the costal plate at least 50 mm. Another
fragment, which appears to be part of a peripheral near one of the buttresses, indicates that a
aot sent its free extremity down deep into the bone forming a gomphosis, as in Zygoramma.

The costals and the peripherals are ornamented ne shallow pits separated by low,
rounded walls, and are arranged somewhat in rows. On the outer ends of the costals and
peripherals the sculpture is often obscure.

Adocus lacer sp. nov.

Plate 34, fig. 8; plate 36, fig. 1; text-figs. 302-307.

The type of this species belongs to the Cope collection in the American Museum of Natural
History. Its number is 1350. There is no history regarding the origin or the finder of the
specimen, but there is no doubt that it was obtained from the upper ereensand bed of the
Cretaceous of New Jersey. There is nothing to indicate to what species Cope referred it.
The materials include the greater portion of the plastron, the nuchal, the three anterior periph-
erals of both sides and a inal portion of the left front costal.

The species is characterized by a plastron (plate 36, fig. 1) which is elongated in proportion
to the width of the base of the hinder lobe. The bridge likewise is longer, in relation to the
width of the hinder lobe of the plastron, than in any of the other species. In width of bridge,
in relation to the length of the plastron from the entoplastron to the rear of the xiphiplastrals,
A. agilis exceeds it. “The hinder lobe resembles most that of the species just named, but the
lateral borders are not so uniformly curved and there is on the upper surface a groove parallel
with the free edge. The dimensions of the various parts are to be obtained from the table
on page 242.

The anterior lobe is not represented in front of the hyoplastron, except by about one-
fourth of the entoplastron. The latter has had a width of about 88 mm. The free border of

16

242 FOSSIL TURTLES OF NORTH AMERICA.

the hyoplastron in front of the axillary notch is acute, differing thus from 4. agilis and 4.
beatus. The hyoplastral and the hypoplastral portions of the median suture are nearly equal
in extent; whereas in 4. agil1s the hypoplastral portion is considerably longer than the hyo-
plastral part. The transverse suture between the anterior and posterior halves of the plastron
is very coarse, there being alternately large pits and processes for mutual gomphosial articu-
lation. The form and proportions of ee hinder lobe may be determined from the table on
this page and from the figure. The free borders are acute, with a parallel groove on the upper
surface. The scar for the pubis resembles that of the other species, but it is more deeply
imprest. Just in front of the hinder border of the xiphiplastrals and lying across the midline
there is a conspicuous elevation, the thickness of the bone here being 16 mm. In the center
of the lobe the bone thins down to about 10 mm.

The pectoral scutes are of considerably greater extent antero-posteriorly than in 4. agilis,
68 mm. as opposed to 36 mm., the humero-pectoral sulcus swinging well forward on the ento-
plastron. The abdominal scutes are larger than those of any of the five species compared
with this one in the table, the sulcus between them being 135 mm. long. The femoral scutes
also exceed those of the other related species, being 100 mm. in the midline. The anal scutes
are relatively short, 75 mm. ‘There are 3 inframarginal scutes on the bridge, the middle one

Table of measurements of species of Adocus.

A. beatus. A.agtlis. | A. syntheticus.| A. punctatus. A. lacer. A. pravus.

Length of plastron. : 420+ sye¥e 454 356 sete 450+
From hinder enh ‘of ento-

plastron to rear of plastron 340+ 310 346 283 355 ere
Hyoplastron on midline...... 100+ 95 R. 85 80 125 110

L. 115
Width of bridge............ 160 185 200+ 144 192
Hypoplastron on “araline 11S 120 R. 147 105 120 130
L. 120

Length of hinder lobe... ..... 148 130 145 130 140
Length of xiphiplastron...... 120 100 115 100 115
Width of plastron at bridge... Ane 290 380 280 285 fey
Width of anterior lobe at base 160 210+ Sats 190 oer 180
Width of hinder lobe at base. . 175 177 230 176 177 BS
Width of entoplastron....... 88 91 95 ay 88 70
Length of entoplastron. . : 54 69.5
Thickness at crossing of asd:

MAN SUCUEES «6 6 coca cee neais 14 1a 16 Ae 17 12
Thickness of epiplastron at

SYMPNYSIS. cass eos. ae etn 15 Pees 14
Thickness of hyoplastron in

front of axillary notch..... 1S 14 14 ate 14
Thickness at front of xiphi-

plastron in midline........ 17 16 18 36 3

being 107 mm. long and 28 mm. wide. In the aauge the sulci are especie as being prema:
than they really are.

The plastron is considerably eroded. The lower surface is furnisht with numerous small
pits, some of them resembling pin-holes, but to what extent these are due to weathering it is
difficult to say.

The anterior rim of the carapace, from one axillary notch to the other, shows that at
these notches the carapace had a width of 455 mm. Whether or not the carapace expanded
backward, as it does in 4. punctatus, can not now be decided. The front (plate 34, fig. 8)
is almost exactly an are of a circle whose radius is 197 mm. The front of 4. punctatus is
somewhat truncated. The rim is thick and heavy, except that the nuchal bone is excavated
on its hinder surface, so that its thickness is only 14 mm. At its articulation with the first
peripherals it has increased to 25 mm. The greatest thickness of the third peripheral, just
in front of the axillary notch, is 40 mm.

The upper surface of the nuchal and of the anterior peripherals is slightly convex from
above downward. ‘The free edge is rather thin and is somewhat reverted, as in 4. punctatus.
The lower side of the peripherals is very convex from front to back; that of the nuchal con-
cave. The free border of the nuchal measures 75 mm. At its upper, or hinder, border it

DERMATEMYDID&. 243

is 92 mm. wide. Its extent front to back is 75 mm. Its hinder border is somewhat exca-
vated for union with the first neural. The free borders of the three anterior peripherals
measure each from 60 mm. to 65 mm. The height of the first is 65 mm.; that of the

third, 83 mm.

Fics. 302—304.—Adocus lacer. Entoplastron, xiphiplastron, and peripheral. 3.

302. Entoplastron, left half. 303. Right xiphiplastron. 304. First left peripheral.

The sulci separating the marginal scutes from the vertebral and the costals is not
far above the free border of the bones. If there were a distinct nuchal scute it has been
effaced by a slight injury to the bone. The first marginal is 25 mm. from front to back.
The height of the ‘succeeding ones increases until that of the fourth is 4o mm. The first

spy

per t oO

Fics. 305-307.—Adocus lacer.—Peripherals. 3.

305. Ninth, tenth, and eleventh peripherals and part of suprapygal.
306. Section near hinder end of ninth peripheral.
307. Section of eleventh peripheral where it joined the pygal.

vertebral scute has a width from side to side of 150 mm. It probably had the form found

in A. punctatus.
In the collection of the Philadelphia Academy there is a lot of bones of an Adocus which

is referred to the present species. There are no data accompanying the specimens, but there

244 FOSSIL TURTLES OF NORTH AMERICA.

can be no doubt that they were found in the Cretaceous greensand of New Jersey. There
are present the left first, ninth, tenth, and eleventh peripherals, a part of the suprapygal,
some fragments of costal bones, the left half of the entoplastron, the left hypoplastron, and
the right xiphiplastron. Fig. 302 represents the piece of the entoplastron. When complete
it was 56 mm. long, 80 mm. wide, and 18 mm. thick at the hinder border. The intergular
scutes encroacht on the front of it and the pectorals on the hinder border. The hinder lobe
was 173 mm. wide at the base and about 135 mm. long. The left hypoplastron is 103 mm.
long. At the midline, between the inguinal notches, it is 28 mm. thick. Fig. 303 represents
the outline of the right xiphiplastron, seen from below. It agrees in form with that of
the type of the species, and shows that the hinder end of the plastron was broadly rounded.
At the middle of the suture with the corresponding hypoplastron it is 18 mm. thick. There
was, near the outer border, a stout process that fitted into the hypoplastron. On the upper
surface is a large depression for the pubic bone. In the midline, at the hinder ends
of the xiphiplastra there is a considerable elevation, and here the thickness of the bone is
20 mm.

Both the hypoplastron and the xiphiplastron are pitted, the latter most distinctly. The
surface of the entoplastron is irregularly pitted.

Fig. 304 presents a view of the first left peripheral, and this may be compared with that
of A. beatus and that of 4. punctatus. It measures 61 mm. along the free border and 68 mm.
at right angles to this. Its greatest thickness, where it joins the nuchal, is 20 mm. It will be
observed that the arrangement of the sulci differs from that of the type and resembles more
that of 4. punctatus. It is to be concluded that the scutes here were somewhat variable in
their development. ‘The free border of the bone is somewhat reverted, as in the type.

The three hinder peripherals are narrow and high (hg. 305). The ninth has a width of
65 mm. and a height of 100 mm.; the tenth a width of 60 mm. and a height of 95 mm.; the
eleventh a width of 58 mm. and a height of 68 mm. With the latter peripheral is a portion
of the suprapygal. Evidently, as in 4. punctatus, the costo-marginal sulci ran at some
distance above the peripherals. A part of the fifth vertebral scute appears high up on the
suprapygal. Figs. 306 and 307 represent the hinder sutural faces of the ninth and eleventh
peripherals.

On the upper borders of the ninth and tenth peripherals are seen remains of the extrem-
ities of the ribs of the seventh and eighth costals, which extend down into the peripherals.
On fragments of the bridge peripherals are seen the rib-ends lying in shallow grooves on the
inner surfaces, sometimes extending downward as much as 50 mm. Other fragments of
bridge peripherals show that the transition from the upper to the lower surfaces was rather
abrupt, there being a decided but rounded angle where the turn was made.

The peripherals and the costals are all ornamented with pits, arranged mostly in oblique
rows. There are about 5 pits in a line 6 mm. long.

Adocus syntheticus Cope.
Plate 36, fig. 2.

Adocus syntheticus, Cope, Proc. Amer. Philos. Soc., x1, 1870, p. 515 (name only); Ibid., p. 548; Op.
cit., x11, 1871, p. 44; Vert. Cret. Form. West, 1875, p. 262.—Hay, Bibliog. and Cat. Foss. Vert.
N. A., 1902, p. 444.

Professor Cope’s first reference to this species did not bear with it any description. The
species was said to be based on a plastron lacking the entoplastron, the right epiplastron and
the right hypoplastron, a peripheral bone from the bridge, 2 imperfect costals, and some
smaller fragments. This type is now in the American Museum of Natural History, and has
the number 1466. All the parts originally described are present, except the hinder extremity
of the right xiphiplastron. The “marginal from the bridge” is a part of the right hypoplastron.
The specimen was found in the upper bed of the Cretaceous greensand, at Barnesboro, New
Jersey.

Professor Cope states that the length of the plastron is 484 mm. This is probably a mis-
print for 454 mm., which appears to be nearer to the correct length. The plastron as a whole

DERMATEMYDID&. 245

is broad and flat. It was truncated in front and broadly rounded behind. With only the
known materials it is impossible to state accurately the length and width of the anterior lobe.
The anterior, truncated end had a width of about 80 mm. The two epiplastrals joined along
the midline for about 37 mm. The anterior free border of the epiplastral is thick, but the
lateral border thins down backward to an edge. The size and form of the entoplastron can be
judged from the surrounding bones. Cope gives the length as 70 mm. and the width as 95 mm.

whith dimensions appear to be correct.

As will be seen from the plate 36, fig. 2, the sutures are extremely irregular in their course.
The entoplastral notch in the hyoplastrals is not symmetrical. On account of unsymmetrical
development, the right hypoplastron articulated with both hyoplastra, the left hypoplastron,
and with both xiphiplastra. The night hy poplastron is thus 27 mm. longer than the left.
These and other measurements are presented 1 in the table on page 242.

Professor Cope states that the length of the hinder lobe of the plastron is 155 mm.; the
width, 230 mm. He also says that a fragment of the bridge displays the axillary and part of
the anterior inframarginal scutes; but to che present writer nie fragment seems rather to belong
to the inguinal region of the right side. The reason for this idennecaror’ is found in the (Ae
that in 4. punctatus and A. Idcin the pectoro-abdominal sulcus starts off from the sulcus bound-
ing the axillary scute on the mesial side, while the abdomino-femoral sulcus does not come into
contact with the inguinal scute on the lower side of the plastron. In the fragment under con-
sideration the arrangement of the sulci conforms to that of the region of fie inguinal notch.
On placing this fragment in this region the hinder lobe is found to have a length of 145 mm.
and a width of 230 mm., being unusually short in proportion to the width.

The central portion of he hinder lobe is thick, but the free borders are thin and acute, the
thickness becoming gradually reduced. On the upper side of the xiphiplastra there is a
prominent curved ridge, and nearer the midline a deep depression. ‘These mark the attach-
ment of the pubic bone. A rounded knob marks the position of the ischium.

The fragment of the bridge which has already been referred to as belonging properly to
the inguinal region bears on its upper, or inner, surface a strong ridge which rises to form a
buttress against the carapace. The inner border of the buttress is sharp. ‘There is another
fragment of the bridge present, the outer end of the right hyoplastral. This does not reach
so far forward as the axillary notch; backward it extends to the hyohypoplastral suture.

The sulci of the plastron are mostly very distinct, but not broad nor deeply imprest. The
longitudinal median sulcus runs a meandering course, but anteriorly it is too obscure to be
traced. There was a large intergular, probably divided. Its width was about 40 mm. Its
hinder border encroacht slightly on the entoplastron. The gulars were widely separated by
the intergular. The pectorals met along the midline for about 42 mm. and overlapt slightly
the entoplastron. The abdominals occupied 35 mm. of the midline; the femorals, about
82 mm.; and the anals, also about 82 mm. The inframarginal scutes were large, the middle
one about 135 mm. long and 50 mm. broad. Outside of the inframarginals are portions of
3 marginals, ake fifth, sixth, and seventh. The sixth is 137 mm. broad, running along the middle
inframarginal for the entire length of the latter.

The Sieace of the plastron i is finely granulated, vermiculated, or pitted, but no definite
pattern of sculpture can be made out. On each side of most of re sutures there is a band of
fine parallel grooves.

Portions of 2 costals are present, showing the proximal ends. One of these is 55 mm. wide
at the proximal end and 8 mm. thick. On the inner surface there is seen the rudimentary
rib-head. The other costal, probably the left seventh, is 38 mm. wide proximally, but it widens
distally. It is notcht proximally for a neural, probably the sixth, and behind the latter it
apparently met the corresponding costal of the opposite side. The surfaces are smooth and
present no distinct evidences of sulci.

The form of the plastron of this species is most like that of 4. agilrs, but it differs from that
of the latter in being relatively shorter, in having the lateral borders more convergent from the
base, and the bone does not thicken so rapidly from the acute free edges. The sculpture of the
plastron of 4. syntheticus is quite different from that of 4. agilis, and the inframarginal
scutes are much broader.

246 FOSSIL TURTLES OF NORTH AMERICA.

Adocus agilis Cope.
Plate 36, fig. 3.

Adocus agtlis, CovE, Proc. Acad. Nat. Sci. Phila. 1868, p. 235; Cook’s Geol. New Jersey, 1868 (1869),
p- 734; Ext. Batrach., Reptilia, Aves N. A., 1869, pp. 11, 233, 234; Proc. Amer. Philos. Soc.,
x1, 1870, pp. 296, 297, 5493 Op. cit., x11, 1871, p. 44; Vert. Cret. Form. West, 1875, p. 262.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 444.

The type of this species is in the American Museum of Natural History and bears the
number 1135. It was collected in the upper bed of the Cretaceous greensand of New Jersey,
at Barnesboro.

The only portion of the animal represented is the plastron (plate 36, fig. 3) and this is not
complete. Cope states in his description that the extremities of both lobes are broken off; but
at present the hinder lobe is complete on the right side. The front of the anterior lobe being
gone, the total length of the plastron can not be determined with exactness. Cope estimated it
at 450 mm.; but this is certainly an error; it was probably not greater than 400 mm., and
more probably about 390 mm.

The plastron is short and broad, but yields in these respects to that of A. punctatus. The
dimensions may be obtained from the table on page 242. The plastron is very flat, even out to
the suture with the peripherals of the bridge, but it is possible that the bridge has been distorted
through pressure. The entoplastron has its anterior angle now broken off, but Cope gave its
length as 69.5 mm. Its width is g1 mm. The free edge of the hyoplastron, just in front of the
axillary notch, is rounded in section. The bridge is, relatively to the length of the plastron
behind the entoplastron, longer than in any species with which it is compared on page 242.

From the inguinal notch the free borders of the hinder lobe curve gradually to the midline
behind. These borders are acute, and from them the bone thickens rather rapidly and without
the intervention of a groove on the upper surface. The center of the lobe has no depression
such as we find in J. lacer and to a less extent in 4. beatus. On the hinder half of the upper
surface of each xiphiplastron there is a large curved depression which marks the place of
articulation of the pubis. It is not so deeply imprest as it isin A. lacer.

Cope gave, as one character separating this species from the others then described, the
thinness of the bones; but they appear to be only a little thinner than those of A. beatus.

The hyoplastron just behind the entoplastron is 13 mm., that of A. beatus, 14 mm.; just
in front of the axillary notch, 14 mm., that of 4. beatus, 17 mm.; medially at the front of the
xiphiplastron, 16 mm., in 4. beatus, 17 mm.

The humero-pectoral sulcus falls behind the entoplastron. The abdominal scutes meet
along the midline for a distance of 105 mm.; the femorals, 87 mm.; the anals, 76 mm. The
inframarginals on the bridge are long and narrow, the middle one being 80 mm. long and
16 mm. broad. The median longitudinal sulcus runs a very irregular course, especially in the
hinder half of the plastron.

The whole lower surface of the plastron is ornamented with a sculpture which consists
of very shallow, somewhat elongated depressions separated by low rounded walls. The pits
alternate somewhat and are arranged more or less in rows. These run usually in a longitudinal
direction. The sculpture is much like that of A. beatus and A. punctatus, and reminds us of
Cope’s description of that of Basilemys imbricarta, but the pits are not nearly so deep as in the

latter species.
Adocus pravus Leidy.

Emys pravus, Lewy, Proc. Acad. Nat. Sci. Phila. 1856, p. 303; Smithson. Contrib. Knowl., X1v., art.
vi, 1865, pp. 108, 120, plate xix, fig. I.

Adocus pravus, Corr, Proc. Acad. Nat. Sci. Phila. 1868, p. 235; Cook’s Geol. New Jersey, 1868 (1869),
p- 734; Ext. Batrach., Reptilia, Aves N. A., 1870, pp. 129, 233, 2343 Proc. Amer. Philos. Soc.,
x1, 1870, p. 297; Ibid., xu, 1871, p. 44; Vert. Cret. Form. West, 1875, p. 262.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 444.

Emys parva, Maack, Paleontographica, xvi, 1869, p. 278.

The present species was discovered by Professor George H. Cook, State Geologist of New
Jersey, in the upper bed of Cretaceous greensand at Tinton Falls, Monmouth County, New
Jersey, and was described by Dr. Joseph Leidy. Originally the type consisted of most of the

DERMATEMYDID&. 24.7

left hyoplastron, a large part of the right hypoplastron, and the hinder ends of both xiphi-
plastra. Of these, there is now in the collection at Rutgers College only the hyoplastron.

The species is characterized by the thinness of the bones, being approacht in this respect
only by 4. agilis. The hyoplastron has a thickness varying from 10 mm. to 12 mm. Accord-
ing to Leidy the hypoplastron varies in thickness from 10 to 14.5 mm.

From the portion of the hyoplastron present it appears that the width of the anterior lobe
at the base was about 180 mm. The hyoplastral bones joined along the midline a distance of
about 110 mm. The entoplastron had an approximate width of 65 mm. and extended back-
ward behind the hyoepiplastral sutures about 40 mm. A sulcus, the humero-pectoral, crosses
the plastron 7 mm. behind the entoplastron and is directed slightly backward on its way out-
ward. ‘The free border of the lobe is subacute. All the sutures of the hyoplastron appear to
have been close and smooth when viewed from below; but, seen from above, they were coarse
and jagged. ;

The hypoplastra are stated by Leidy to have extended along the midline 5 inches; accord-
ing to his figure, 130 mm. The hinder end of the plastron appears to haye been narrowed, as
in A. beatus.

This species seems to have most resembled 4. agilis; but the entoplastron of the latter is
considerably broader, less abruptly rounded, and the notch was more open. In 4. syntheticus
and 4. punctatus the humero-pectoral sulcus crosses on the entoplastron.

This species differs from Cope’s specimen of 4. beatus, from Medford, in having a narrower
entoplastron. In the latter the width of this bone was about equal to the length of the suture
between the right and left hyoplastra. In 4. pravus the width was equal to only two-thirds
the suture between the hyoplastra. In other respects the two species, so far as known, appear
to agree. Altho Leidy has restored in outline the anterior lobe of 4. pravus as being very
narrow, it may in reality have been much broader.

Adocus? lineolatus Cope.
Figs. 308, 309.

Adocus? lineolatus, Corr, Bull. U. 5. Geol. and Geog. Surv. Terrs., 1, No. 2, 1874, p- 30; Ann. Report
U. S. Geol. and Geog. Surv. Terrs., 1873 (1874), p. 454; Vert. Cret. Form. West, 1875, p.
g2.—LamseE, Contrib. Canad. Paleont., 111 (4to), 1902, p. 38.

Adocus lineolatus, Corr, Vert. Cret. Form. West, 1875, p. 263, plate v1, figs. 11, 12.—Hatcuer, Bull.
U. S. Geol. Surv. No. 257, 1905, p. 75.

Compsemys lineolatus, Core, Bull. U.S. Geol. and Geog. Sury. Terrs., 111, 1877, p. §573-—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 437-

Of the present species very little is known. The name is based on 2 fragments which were
collected by Professor Cope, in northeastern Colorado. From Whitman Cross (Monogr. U.S.
Geol. Surv., xxvit, 1896, p. 244) we learn that Cope communicated the fact that these and
some other fossils had been collected at some point not designated on Bijou Creek.

Cross is of the opinion that these fossils came from what are called by him the Arapahoe
beds, a formation overlying the Laramie. Cope’s type of his Adocus? lineolatus is now in the
American Museum of Natural History and has the number 1844. Cope’s figures represent
well the specimens; but since they have been figured the surface has been scraped from the
neural, so that its sculpture no longer appears. That of the fragment of plastron remains. It
is obscure, but consists of elongated, very shallow pits, four or five in a line 5 mm. long, and
arranged more or less in rows and separated by low narrow ridges. The neural has a maxi-
mum width of 28 mm. and a thickness of 7 mm. The plastral bone is 8 mm. thick at the
sutural border. This suture is coarse and, as Cope says, has a median serrate keel, with pits on
each side of it for the reception of processes from the bone with which it articulated.

Cope stated that the species comes also from the mouth of the Big Horn River, but the
present writer does not know of any specimens on which this identification was based. Cope
likewise includes the species in his list of Judith River species. Lambe, as cited, reports it
from the Belly River beds on Red Deer River, Alberta, British America. His specimens too
were fragmentary. Specimens with a sculpture very similar have been brought to the American
Museum of Natural History from the Laramie beds of Montana. These were collected by

248 FOSSIL TURTLES OF NORTH AMERICA.

Mr. Barnum Brown, on Hell Creek, Montana. Fragments of costals scarcely, if at all, to
be distinguisht from them are found in the collection made 1 in the Judith River region for
Peoieccor Cope, by C. H. Sternberg, in 187 6. It is the writer’s opinion that it is ameate to
identify as belonging to Adocus lineolatus specimens from the Judith River and the Laramie
beds before far beter materials of the species have been collected from the type locality. And
when these better materials have been secured from Bijou Creek, better specimens than yet
obtained must be secured from the other formations mentioned. It is improbable that the
same species continued from the Judith River epoch to the Arapahoe epoch. Meanwhile,
even good fragments are worth preserving.

The specimen referred to above as having been collected by Sternberg from the Judith
River region forms No. 6105 of the American mivlaceun It belonged to ne third or the fifth
costal. Its width is 32 mm.; its thickness, only 3.5 mm. There is no thickening along the
middle on the under side corresponding to the rib. The outer surface 1s crost by the costo-
vertebral sulcus. The ornamentation resembles in pattern that of Cope’s Compsemys 1m-
bricarta (Basilemys imbricaria), and Cope has so labeled the bone; but the size of the areole is
considerably smaller, there being 4 pits in a line 5 mm. long, instead of 3 or less. The ridges
between the areola are low and run at right angles with the sutural borders of the bone.

A fragment of a costal from Hell Cheek, Momeanar collected by Mr. Barnum Brown, is
catalogged under the number ror4 of the American Museum. ‘The costal is 36 mm. wide
and 5 mm. thick. The sculpture is similar to that of the Judith River specimen just
described, but is more obscure.

A peripheral, the second of the left side, has the number 1o14, but it belonged to a much
larger individual. It is represented by figs. 308 and 309. ‘The bone is 55 mm. high, 48 mm.

———"4 along the free border, and 32 mm. along the
aN costal border. Fig. 309 represents the border
\ \ joining the first peripheral, the greatest thick-

ae ness being 16 mm. ‘The sutural border for the

fineness ascribed to the costal. It resembles
apes greatly that of the fragments numbered 6103
Fics. 308 AND 309.—Adocus lineolatus. Periph- A. M. N. H. and deseribed under Basilemys

eral and section. X4. No. 1org A. M.N.H. imbricarta.

No. 6107 A. M. N. H. includes a fragment
of a costal plate and another of a plastral bone
which were collected for Professor Cope, in 1877,
by Mr. J. C. Isaac, in the Laramie of Converse County, Wyoming. The sculpture of these
bones resembles closely that of 4. lineolatus, type.

\ : | = S\ 309. 24mm. The sculpture has the pattern and the

308. Second left peripheral.
309. Section of sare peripheral at union with third.

Genus AGOMPHUS Cope.

Shell thick and heavy in the known species. Free borders of the carapace thickened and
obtuse. Exposed surfaces of the shell not pitted. Hinder marginal scutes not rising on the
costal bones, except slightly in one species. Inframarginal scutes present. The pectoral
scutes extending forward to the hinder end of the epiplastrals. Intergulars not known. Nuchal
with costiform processes. Rib-heads more strongly developt than in Adocus.

Type: A gomphus turgidus Cope.

The genus 4 gomphus was founded by Cope in 1871 (Proc. Amer. Philos. Soc., x11, p. 46)
having 4. turgidus as the type. The only character given was the apparent lack of gomphosis
between the costals and the pea ee an insufhcient character, if a true one. In 1882

(Pr roc. eas Betas Soc., Xp 145) pa ce sa se Dermate omys In the Emy-

nen a robes: of che ae ade The same eae are Phe in that author’s Vertebrata
of the Tertiary Formations of the West, in 1884. In both the publications referred to, the
genus Amphiemys was placed among the Adocidz. Baur in 1888 ( Zool. Anzeiger, X1, p. 595)
redae ed Amphiemys to the position of a synonym of 4 gomphus and arranged the latter under

third peripheral has a maximum thickness of

DERMATEMYDID&. 249

the Adocidz. In 1891 (Proc. Acad. Nat. Sci. Phila., p- 429) Baur retains Agomphus in the
Adocidee and gives as its distinguishing characters the narrow lobes of the plastron and the
shorter bridge. He states too that it has costiform processes which reach the second peripheral,
piercing the first.

The general form of the shell of the species of this genus is indicated by that of 4. tardus

Wieland.

KEY TO THE SPECIES OF AGOMPHUS.

A‘. Upper Cretaceous species.
a‘. With the costo-peripheral sulci, so far as known, confined to the peripheral bones.
1. Plastron nearly flat transversely ; entoplastron broadly rounded behind ; pectoro-
abdominal sulcus much nearer the hyohypoplastral suture than to entoplastron;
costo-marginal sulci above middle of peripheral bones; costal border of peripherals

much thinner than maximum thickness............. 0000 ccc ceccccccceceee. turgidus
2. Plastron strongly convex transversely; costo-marginal sulci below middle of periph-
Ela SHOP ta sree rr ces eT aie eee ee din Ge petrosus

3. Like petrosus, but plastron not so convex ; costo-marginal sulci above middle of

MSS ram mecca ate fates Tela a ests acres Yor. ane ce, exten, at hans! i clara cca nea chy acraatho ecoaceae te news ini eoenkls tardus
4. Entoplastron pointed behind; pectoro-abdominal sulcus nearer hyohypoplastral

suture than to entoplastron; suture between the hyoplastra 0.25 of the hyohypo-

plastral suture........... Bee etic ah woes Me etary ne oats tian ae pectoralts
5. Entoplastron truncated behind; pectoro-abdominal sulcus nearer entoplastron than

to hyohypoplastral suture............. .. firmus

1. Entoplastron pointed behind; suture between hyoplastrals 0.35 of the hyohypo-

MieeTStede Pe Core ism orata Maia ach auarateias A er oe ee ee ae masculinus

A’. Early Tertiary species.

r. With hinder lobe of plastron much narrowed behind. . . oxysternum

Agomphus turgidus Cope.
Plate 37, figs. 1-5; text-fig. 310.

Emys turgidus, Corr, Ext. Batrach., Reptilia, Aves N. A., 1869, pp. 125, 127—?WiELanp, Amer.
Jour. Sci. (4), XX, 1905, p. 440, fig. g, in part.

Agomphus turgidus, Cope, Proc. Amer. Philos. Soc., x11, 1871, p. 46; Vert. Cret. Form. West, 1875, p.
262.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445.

This species, the type of the genus A gomphus, is based on portions of the skeleton which
were obtained from the upper greensand bed of the Cretaceous of New Jersey. The materials
consist of both hyoplastra somewhat damaged; the entoplastron; the fourth neural; the
proximal ends of the third, fourth, fifth,and sixth costals of the left side, and of the third, fourth
and sixth of the right side; some fragments representing the distal ends of costals; and four
peripherals, one from the bridge. The specimen is now in the Cope collection in the American
Museum of Natural History, and bears the number 1481.

The portion of the plastron (plate 37, fig. 1) preserved has been considerably eroded.
The epiplastrals being gone, nothing is known regarding the form of the front of the plastron.
The front lobe had a width of go mm. at the base. The free border, as far as represented, is
thin and rounded in section, and a shallow groove runs parallel with it on the upper side.
Toward the midline the bone thickens rapidly, and at the hinder border of the entoplastron it
is 14 mm. thick. This increases to 17 mm. at the crossing of the median longitudinal and
transverse sutures. ‘The entoplastron is rather pointed in front, broad and rounded behind.
It is slightly broader than long, thin in front (6 mm.) and thick behind (14 mm.).

The transverse suture behind the hyoplastrals is somewhat irregular in direction. ‘The
denticulations are fine, but there are some grooves and keels near the midline.

Professor Cope states that only the longitudinal median sulcus is to be made out. Yet to
the present writer it seems clear that there is one which crosses the entoplastron, the humero-
pectoral, and another which crosses the hinder ends of the hyoplastrals, the pectoro-abdom-
inals. These are in exactly the positions of the corresponding sulci in 4. pectoralrs. The

l

250 FOSSIL TURTLES OF NORTH AMERICA.

surface of the plastron appears to have been somewhat uneven, but no definite pattern of
sculpture can be made out.

The fourth neural (plate 37, fg. 5) has a length of 27 mm., a width of about 24 mm., and
a thickness of 11 mm. The costals at the proximal ends are as thick as the neurals, but they
rapidly become thinner, so that at a distance of 30 mm. from the neurals a costal is only 5.5 mm.
thick; and this thickness is maintained to the distal ends. The capitula of the ribs are well
developt. The sulci limiting laterally the vertebral scutes are deeply and sharply imprest.
These vertebral scutes were Sather narrow, about 43 mm. wide. The third vertebral has a
length of 60 mm. ‘The surface of the bone is finely striated longitudinally.

Plate 37, fig. 4, represents 3 peripherals which appear to have had the positions assigned
to them, the eighth, ninth, and tenth of right side, but possibly the ninth, tenth, and eleventh.
The one seen on the right of the figure is the anterior, but it did not articulate with the
hypoplastron. Each has an extreme thickness of about 11 mm. ‘The exterior surface is con-
cave vertically, while the inner surface is strongly convex. Fig. 310 is a section through the
middle one of the three. Altho the free edge of che series 1s somewhat eroded, it evidently was
rounded. Further forward this edge appears to have been more angulated, until, as represented
by one of the bridge peripherals, the upper side of the shell madel abruptly an angle of about
45° with the lower side. The marginal scutes of this species were confined to the peripheral
bones, instead of extending upward on the costals. As shown in the figures, the costal scutes
come down well on the peripherals.

The carapace of this species had a length of about 265 mm.

In the Cope collection at the piensa Museum there is a pair of hyoplastrals, No. 1479
(plate 37, fig. 2), which evidently belongs to this species and which is labeled as having been

found at Mount Holly, New Jersey, in 1870. It has the size of

the corresponding bones of the type, but it is considerably

thicker, being 20 mm. just behind the entoplastral notch and

also at the hinder border of the bones near the midline. About

one-third the distance from the notch toward the rear the thick-

ness is 22mm. This specimen displays the pectoro-abdominal

pees. ; sulcus and a portion of the inframarginal scutes on the left
IG. 310. A gomphus turgidus. “d Th ] i E h 4 b oS d é 4 ee
Sethon Rage GE penphe side. e latter appear to have been arranged as in 4. pec
eral of type. Xx. toralts. The median sulcus is obscure, but what appears to be
a portion of it is seen on the right side running backward

from the transverse sulcus, while apparently another short branch is seen on the left side.

The surface of the plastron contains several large shallow pits and long grooves, as shown
in the figure cited. It is evident that these have been made during the life of the animal, the
result probably of some disease. Fig. 3 of plate 37 represents the same hyoplastrals seen from
the front.

Agomphus petrosus Cope.

Plate 36, fig. 4; plate 37, figs. 6, 7; text-figs. 311-313.

Adocus petrosus, Corr, Proc. Acad. Nat. Sci. Phila. 1868, p. 236; Cook’s Geol. New Jersey, App. B,
1868 (1869), p. 734; Proc. Amer. Philos. Soc., x1, 1870, p. 295.

Emys petrosus, Corr, Ext. Batrach., Reptilia, Aves N. A., 1869, pp. 125, 126.

Agomphus petrosus, Corr, Proc. Amer. Philos. Soc., xu, 1871, p. 46; Ann. Report U.S. Geol. Sury.
Terrs., 1872 (1873), p. 625; Vert. Cret. Form. West, 1875, p. 262.—Hay, Bibliog. and Cat. Foss.
Vert. N. A.; 1902; p. 445.

The type of this species is now a part of the Cope collection in the American Museum of
Natural History in New York. It consists of a portion of the right hyoplastron; 5 peripheral
bones, with perhaps a fragment of another; portions of four costal bones; a fragment of the
right hypoplastron; and what Cope regarded as the head of the coracoid, but which seems to
be rather the articular end of the pubis. These have been catalogged under the number
1482. They were collected from the upper greensand bed of the Gretaceots, at Gloucester,
New Jersey.

The plastron (plate 36, fig. 4) was not flat below like that of the species of the other
species of Agomphus, but very convex. Cope states that the curvature from the peripherals

DERMATEMYDID&. 251

of one side to those of the other amounts to 124°. Unfortunately the free border of the front
lobe has not been preserved, so that it is impossible to determine the width of the lobe at the
base; but it could not have been far from 100 mm. The notch for the entoplastron shows that
this bone had a width of 42 mm. It appears to have been broadly rounded behind. While
the thickness at the hinder border was about 17 mm., it was much thinner at the front. The
thickness of the hyoplastron a short distance behind the entoplastron is 20 mm.; at the hinder
border of the hyoplastron in the midline, 15 mm.; at the articulation with the ffth peripheral
1omm. ‘The bone is therefore very thick and its tissue is dense and heavy.

There is present a fragment of the free border of the hypoplastron, including a portion of
the sutural border for the xiphiplastron. At a distance of 28 mm. from the free border the bone
is 18 mm. thick. This continues to within about 20 mm. of the border, and then the bone is
rapidly beveled off to a blunt edge. The lower surface of the bone curves upward to meet the
bevel.

The surface of the hyoplastron and of the fragment of the hypoplastron is very smooth,
having apparently been polisht during the life of the animal. The proximal end of the first
costal is preserved. Its neural border is concave for the first neural. Its hinder angle joined
the second neural. Here the bone is 12 mm. thick. In front it is 8 mm. thick. On the under
side are seen the base of the rib-head and articulation for the first rib.

Two adjacent costals of the right side (plate 37, fig. 7), the fourth and the fifth, or the
fifth and the sixth, are present. They are each 45 mm. in width at the proximal end. At the
suture with the neurals they are 16 mm. thick; at a distance of 60 mm. from the neurals one
has still a thickness of g mm. The capitula of the ribs are moderately developt. Little or no
trace is left of the rb on the inner side of the costal plates. These costals are considerably
archt, showing that, with the curvature of the plastron, the shell was high and vaulted.

Fics. 311-313.—Agomphus petrosus.

Peripherals of type. Xj.
311. Section at anterior end of second peripheral. ;
312. Section at anterior end of supposed eighth
peripheral. 212
313. Section across supposed first peripheral of oe
left side. :

Two anterior peripherals (plate 36, fig. 4), the second and the third of the right side, are
connected with the outer anterior angle of the hyoplastron. They are thick and massive.
The free edge of these peripherals is rounded like the edge of one’s hand, and at the anterior
end of the second the border is slightly everted. Fig. 311 represents a section taken at this
point. The thickness here is 15 mm. The second peripheral is 40 mm. in length along the
free border and 40 mm. high. The third is 50 mm. long. The hinder border of the latter
peripheral and the anterior lateral process of the hyoplastron furnish the articular border for
the fourth peripheral; while behind this is a part of the articular border for the fifth periph-
eral. Two of the hinder peripherals (plate 37, fig. 6), supposed by Cope to have been the
eighth and the ninth, are at hand. The supposed eighth did not articulate with the hypoplas-
tron as it appears to have done in Wieland’s 4. tardus and may therefore be the ninth. The
fragment of costal attacht to it appears to be the fifth, since on it there is no trace of a descend-
ing sulcus. These, with the distal end of the fifth costal, are figured on plate 37. Fig. 312
presents a section across the anterior end of the supposed eighth. The free borders of these
peripherals are thick and rounded like those of the anterior peripherals. The greatest thickness
of the eighth is 20 mm.; but where the bone articulates with the costal the thickness is reduced
to6mm. The ninth peripheral has the border considerably flared upward and more acute than
further forward. Accompanying the type is another peripheral (fig. 313) which Cope has
labeled as the first of the left side. On one side there is an excavation, as if for the nuchal.
However, there are difficulties in regarding it as the first peripheral of this species One of
these is the great thickness of the bone where it would come in contact with the second periph-
eral, being 19 mm., whereas the corresponding border of the second peripheral of the right
side is only 16 mm. thick. Again, as the upper surface approaches the free border, it curves

22. FOSSIL TURTLES OF NORTH AMERICA.

downward; whereas, the border of the second peripheral is turned upward. It is probable
that the bone is an intrusion from another species.

The sulci of the plastron are wholly effaced. On the costals they are narrow, but distinct.
As seen from plate 37, fig. 7, the sulci limiting the vertebral scutes laterally are not far removed
from the costo-neural sutures. The first vertebral was evidently wider than those succeeding
it. If the neurals had the relative width that they have in Adocus punctatus, the third vertebral
must have been 52 mm. wide. On the second and third peripherals the longitudinal sulci
lie not far above the free border of the carapace. The sulci on the supposed eighth and ninth
peripherals are so obscure that they can not be traced.

Agomphus tardus Wieland.
Text-figs. 314-318.
Agomphus tardus, WIELAND, Amer. Jour. Sci. (4), XX, 1905, p- 430, figs. I-7.

This species was found in the Cretaceous marl pits at Birmingham, Burlington County,
New Jersey, in 1869. The type forms number 774 of the Marsh collection at Yale University.
The parts recovered are most of the nuchal, the second and the fifth neurals, the first and
second left costals; fragments of the third and fifth, and the whole of the eighth right costals;
of the right peripherals, the first, eighth, ninth, and tenth; of the left side the fifth, sixth, tenth,
and the eleventh; the left hyoplastron, and the right hypoplastron. These parts have enabled

wp
sl

xiph 315.

Figs. 314 AND 315.—dgomphus tardus. Carapace of type.

314. Sections at anterior ends of peripherals indicated by the numerals. 2%. cc, in first peripheral, pit for pro-
cess of nuchal. s, in eighth peripheral, sutural border for union with hypoplastron; py, section of pygal.
315. Shell seen from left side. 0.23 c. p.1,etc., costal plates; epz, epiplastron; hyo, hyoplastron; hypo, hypo-

plastron; nu. p, nuchal plate; per.1, per.2, etc., peripheral bones; «ph, xiphiplastron.

Dr. Wieland to restore satisfactorily the form of the shell. A number of his fgures are here
reproduced.

The bones of this species were even thicker and heavier than in 4. petrosus. The shell
(figs. 314-318) was elongated and rather high. From the highest point the carapace sloped
gently to the front, hale: the rear sloped rapidly downward. The length of the carapace was
about 330 mm.; the greatest breadth, about 230 mm. The nuchal bone is 53 mm. long and
52 mm. wide along the free margin. It is 13 mm. thick near the free margin and 7 mm. thick
posteriorly. The second neural has a length of 40 mm., an extreme width of 35 mm., anda
thickness of r4 mm. The fifth neural is 40 mm. long, 36 mm. wide, and 15 mm. thick. As
in A. petrosus, the first costal attains considerable thickness at the junction with the second
and third peripherals, being here 22 mm. thick. The mb-heads are diminutive. All the
peripherals are very obtuse at their free borders. Fig. 314 shows the form of the anterior end
of the first, the second, the eighth, the ninth, the tenth, and the eleventh peripherals, as well
as of the border of the pygal chee joins the eleventh peripheral. It will be observed that the
thickness of the first and the second near the middle of the height is maintained to the costal
border.

The nuchal scute is moderately broad. The sulci bounding the vertebrals and the costals
have not been observed. ‘The costo-marginal sulci run along on the upper half of the periph-
erals, without at any time reaching the costal bones.

DERMATEMYDID&. 253

The entoplastron is not present, but the notch in the front of the hyoplastron shows that
the entoplastron was broadest behind. Its width was about 45 mm. The hyoplastron (fig.
318) is 60 mm. long on the midline and about 100 mm. wide. Its greatest thickness, at the
midline, is 27 mm. Laterally it thins to about g mm. The hypoplastron is 62 mm. long on
the midline, 95 mm. wide, and 31
mm. thick. The bridge was about
106 mm. wide.

No sulcus has been observed
crossing the front of the hyoplastron
and theentoplastron. The pectoro-
abdominal crosses in front of the
hyohypoplastral suture, as in 4.
petrosus. The abdomino-femoral
sulcus swings well forward on the
hypoplastrals. So far as observed,
there is only an axillary inframar-

Fic. 316.—Agomphus tardus. Shell of type, seen ginal oie behind it a single: addi-
from right side. 0.23. Lettering with same tional scute. It Bee e probable
signification as in Fig. 315. that the latter will be found to

have been subdivided.

This species appears to differ from 4. petrosus, its closest ally, in the following respects:
The marginal scutes extend higher on the peripheral bones; the second peripheral is relatively
higher; this peripheral of 4. tardus is not so thick near the free border, but thicker at the upper

xiph aes

Sif 318.

Fics. 317 AND 318.—Agomphus tardus. Shell of type. 0.23.

317. Carapace, seen frorn above. c.p.1, ¢.p.8, costal plates; .1, 2.8, neural bones; nu. p, nuchal bone;

‘ per. 1, per, 11, peripheral bones; py, pygal; spy, suprapygal. ;

318. Shell, seen from below. ab, abdominal scute; an, anal scute; epi, epiplastron; ent, entoplastron; fem,

; femoral scute; yo, hyoplastron; hypo, hypoplastron; pec, pectoral scute; per. 2, per.6, per.11, peripheral

bones; xi ph, xiphiplastron.

border than in 4. petrosus; the third peripheral is not so long (38mm.) as itis in 4. petrosus (45
mm.); the upper, or costal, borders of 4. tardus are thicker and the outer end of the hyo-
plastron has not so strong an upward curve as in 4. petrosus.

From 4. turgidus this species differs in having the peripherals nearly as thick at their
costal borders as the maximum thickness.

254 FOSSIL TURTLES OF NORTH AMERICA.

Agomphus pectoralis (Cope).
Plate 37, figs. 8, 9.
Pleurosternum pectorale, Cops, Proc. Acad. Nat. Sci. Phila. 1868, p. 236; Cook’s Geol. New Jersey, App.
B, 1868 (1869), p. 734; Ext. Batrach., Reptilia, Aves N. A., 1869, p. 130.
Adocus pectoralis, Cove, Batrach., Reptilia, Aves N. A., 1869 (1870), pp. 11, 233, plate vu, fg. 1; Proc.
Amer. Philos. Soc., x1, 1870, pp- 296, 548; Proc. Amer. Philos. Soc., x11, 1871, p. 43; Vert. Cret.
Form. West, 1875, p. 262.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 444.

The first mention of this species, under the name Pleurosternum pectorale, occurs in the
Proceedings of the Academy of Natural Science, Philadelphia, 1868, page 236, in the de-
scription of Agomphus petrosus. This mention may be regarded as sufficient to fix the date
of the species, altho the description is very brief and only incidental. Under the same name a
full description and a figure were publisht in 1869, in the author’s work, Synopsis of the
Extinct Batrachia, Reptilia and Aves of North America. In a part of the same paper issued in
1870, the species was assigned to the genus Adocus. ‘To the present writer the species appears
to belong to Agomphus.

Agomphus pectoralis is up to the present time known to us by only the type specimen,
which consists of both hyoplastral bones (plate 37, figs. 8, g). These are now in the Cope
collection, in the American Museum of Natural History, in New York, and they have the
catalog number 1478. The specimen was found in the upper bed of the Cretaceous green-
sand, near Medford, New Jersey. These hyoplastrals are complete, extending from the
sutures for the bridge peripherals of one side to those of the other. The width from side to
side is 146 mm. The free borders of the anterior lobe pass by a broad curve into the axillary
notch, making it difficult to determine accurately the width of the front lobe at the base. It
may be regarded as about 85 mm.

The free borders of the epiplastrals are subacute, and from them the bone thickens
gradually to the median longitudinal suture. At the hinder angle of the entoplastron the
thickness is 15 mm.; at the hinder border of the hyoplastrals, in the midline, the thickness is
20mm. Where these bones have joined the peripherals of the bridge, they are only8 mm. thick.

The hyoplastrals are deeply notcht for the reception of the entoplastron. This is pro-
longed further backward than in the other species of the genus. The axillary notches, too, are
very deep and narrow. Outside of each notch the hyoplastron sends upward and forward a
strong process, or buttress, against the carapace. Inwardly this forms a sharp crest.

The dermal scutes of this species differ considerably from those of the species of Adocus.
Professor Cope thought that there had been a fusion of the humeral and the pectoral scutes,
and that the sulcus seen crossing the extreme anterior end of the left hyoplastron was the
posterior boundary of the gular scute. It seems more probable, however, that this sulcus
represents the posterior limit of the humeral. This interpretation throws the humero-pectoral
sulcus indeed far forward, but it is little more so than it is in Dermatemys mawii (Boulenger,
Cat. Chelonians, p. 28, fig. 8). On the outer ends of the hyoplastrals there are represented
three inframarginals. The axillary is small and, outside of the notch, extends well forward.
The second inframarginal is hexagonal and represents the hinder end of the axillary of Adocus
punctatus. The third inframarginal rested principally on the hypoplastron. In dlamosemys
substricta the arrangement is somewhat as in the species here described. The whole arrange-
ment of the scutes resembles closely that of Dermatemys mawit, and there is little in the species
as known to exclude it from that genus. The species is here referred to the genus 4 gomphus
because of its close resemblance to 4. turgidus. Only specific differences are observable.

Agomphus firmus (Leidy).

Emys firmus, Lery, Proc. Acad. Nat. Sci. Phila. 1856, p. 303; Smithson. Contrib. to Knowl., xiv, 1865,
p. 106, plate xix, figs. 2, 3—Copr, Ext. Batrach., Reptilia, Aves N. A., 1869, pp. 126, 127.—
Maack, Palzontographica, xvi, 1869, p. 277-

Adocus firmus, Cope, Proc. Acad. Nat. Sci. Phila. 1868, p. 235; Cook’s Geol. New Jersey, 1868 (1869),
p. 734; Proc. Amer. Philos. Soc., x1, 1870, p. 295.

Agomphus firmus, Corr, Proc. Amer. Philos. Soc., x11, 1871, p. 46; Vert. Cret. Form. West. 1875, p.
262.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445.—WreLanp, Amer. Jour. Sci. (4),
XX, 1905, p. 443.

DERMATEMYDID:. 255

The materials possest by Leidy when he described this species consisted of the third,
sixth, and the seventh left peripherals, the sixth, seventh, and eighth peripherals of the right
side, a portion of the left hyoplastron, and a portion of the right hypoplastron. “These had
been placed in Dr. Leidy’s hands by Professor George H. Cook, of the New Jersey Geological
Survey. They had been found in the uppermost Gnetaceoiis greensand, at Tinton Falls,
Monmouth County, New Jersey. The sixth and seventh left peripherals and the parts of the
plastron were figured by Leidy, as cited above, and these are now in the State collection
at Rutgers College, New Brunswick, New Jersey. The peripherals mentioned by Leidy are
not in this collection at present. ;

For figures of the scanty remains forming the type the reader is referred to Leidy’s paper
in the Smithsonian Contributions cited in the synonymy.

The length of the figured peripherals is 140 mm. The height of the seventh is 93 mm.
The costo-marginal sulcus crosses these peripherals between the upper and middle thirds.
This shows that the species does not belong to d4docus.

The left hyoplastron has a length of 80 mm., altho its length along the median suture is
somewhat less. The hypoplastron chad a length of 85 mm. but only 65 mm. at the midline.
As shown by Leidy’ s figure, the hypoplastron articulated both in front and behind with the
bones of the opposite Sac a condition not unusual with the members of the family. The
thickness of the hyoplastron at the midline and just behind the entoplastron is 26 mm. The
greatest thickness of the hypoplastron is 1g mm.

The excavation in the front of the hyoplastron shows that the entoplastron was truncated
behind and that its width was about 65 mm. The pectoro-abdominal sulcus crost the hyo-
plastron somewhat in front of the middle of its length; while the abdomino-femoral crost
the hypoplastron about the middle of its length.

This species, known up to the present time from only the type specimens, differs from all
the other described species of 4 gomphus in having the entoplastron truncated behind and in
having the pectoro-abdominal sulcus cross nearer ‘the entoplastron than to the hinder border
of the hyoplastron.

Agomphus masculinus Wieland.

Fig. 319.
Agomphus masculinus, WirLanp, Amer. Jour. Sci. (4), XX, 1905, p. 437, fg. 8.

The type of this species belongs to the Marsh collection at Yale University Museum and is
numbered 671. It consists of the complete plastron and some portions of the carapace, includ-
ing some of the hinder peripherals. It was collected
in the Upper Cretaceous marl bed at Barnesboro,
Gloucester County, New Jersey, in 1872.

The plastron (fig. 319) resembles closely that of
A. turgidus, so far as the latter is represented. Dr.
Wieland has mentioned one character which differ-
entiates the carapace from that of Cope’s species just
mentioned. In 4. masculinus the eleventh and
twelfth marginal scutes overlap the lower ends of
the eighth costal bone and the suprapygal; whereas
in A. turgidus these marginals do not rise above
the peripherals. This appears to be a sufficient
specific distinction.

The length of the plastron is 170 mm.; the
extreme width, 130 mm. The anterior lobe narrows
rapidly from the base to the blunt tip. The width
of the base of the lobe is about 92 mm.; the length,
41 mm. The epiplastrals are narrow. The ento-
plastron 1s subrhombic, 33 mm. long and 36 mm.
Fic. 319.—Agomphus masculinus. Plastron wide. Its thickness is 15 mm. The other plastral

of type. 3. Redrawn from Wieland’s bones are unsymmetrical, as is common among the
figure. older turtles. The left hyoplastron joins the right

256 FOSSIL TURTLES OF NORTH AMERICA.

hypoplastron a distance of 14 mm.; while the right hypoplastron comes into contact with the
left xiphiplastron. ‘The greatest thickness of the hyoplastron and hypoplastron is 18 mm.
The distance between the entoplastron and the xiphiplastron is 84 mm. Half of this may be
regarded as belonging to the hyoplastrals; the other half to the hypoplastron,

The bridge is 100 mm. wide. The hinder lobe is much reduced. The width at the base
is about 68 mm.; its length, 48 mm. The greatest thickness of the xiphiplastra is 16 mm.

The plastral scutes are well exhibited. Leaving out of count the inframarginals, there
are 5 pairs of plastral scutes, instead of the 7 that we find in ddocus. One pair occupies the
area covered in 4docus by the intergulars, the gulars, and the humerals. This pair joins along
the midline a distance of 23 mm. The members of the pair differ somewhat in size and form.
Behind this pair the median sulcus is erratic in its course. The pectorals measure 48 mm.
along the midline; the abdominals, 31 mm.; the femorals, 38 mm.; the anals, 28 mm. Here,
as in 4. tardus, there appear to be only two inframarginals on each bridge, a small axillary
scute and a very large scute behind this, reaching to the inguinal notch. Sonic of the marginal
scutes descend on fie outer ends of the plastral bones.

As stated, the eleventh and twelfth marginal scutes rise above the superior borders of the
peripherals supporting them. In front of them the marginals are confined to the peripherals.

Agomphus oxysternum (Cope).
Fig. 320.

Amphiemys oxysternum, Corr, Proc. Amer. Philos. Soc. xvi, 1877, p. 82; Palaontolog. Bull. No. 25,
1877, p. 2; Amer. Naturalist, x11, 1878, p. 129.

A gomphus oxysternum, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445-—WIELAND, Amer. Jour.
Sci. (4), XX, 1905, p- 443.

The type of the present species is in the collection of the Geological Survey of Georgia, at
Atlanta, where the writer has been permitted to study it. The specimen was found near Monte-
zuma, Macon County, near the Flint River, in what is known
as the Midway formation, a member of the Lower Eocene. It
is in the same condition as when it was described by Professor
Cope, the plastron being present, as well as the anterior portion
of the carapace and the left border as far as the hinder end of the
eighth peripheral. The core of matrix which filled the shell is in
large part present and on it are indicated the sutures between the
series of neural and costal bones. In form the shell appears to
have been similar to that of 4. tardus.

The length of the carapace, from the front of the nuchal to the
hinder border of the seventh costal, is 242 mm. Cope gives this as
250mm. The width is 184 mm.; the height, 150 mm. or a little
more.

The free border in front of the bridge is thick, obtuse, and
slightly flared upward. The hinder end of the eighth peripheral
is 18 mm. thick, and the free border is very obtuse. The nuchal
bone measures about 50 mm. along the free border, 75 mm.
where widest, and 41 mm. from front to the rear. The neurals,
except the first, are slightly wider than long. The dimensions of
three of them are given in the table on the “following page.

The neurals and costals are thick. Cope states that the
second neural is 13 mm. thick; the second costal, 12 mm. The
Fic _ latter bone near the neural is only 10 mm. a The first per-

IG. 320. —A gomphus ox yster- 28 | hr d
poe (Cape ane ipheral measures along the free border 38 mm.; the third, 40
x}. mm. The first is 33 mm. high; the second, 38 mm.
The first vertebral scute is 53 mm. long and 52 mm. wide.
Its lateral borders are nearly parallel. The second vertebral is 70 mm. ode The marginal
scutes, as far backward as the middle of the bridge, run about is mm. below the costo-periph-
eral sutures.

DERMATEMYDID&. 257

The plastron has the extremities of the front and hinder lobes slightly elevated above the
portion between the bridges. The length is 211 mm. The anterior lobe is broadly rounded in
front; the posterior is short and pointed behind. The width of the anterior, on a line crossing
at the hinder border of the entoplastron, is 102 mm.; its length
is 57mm. The entoplastron is pointed in front, rounded behind,
42 mm. long and 46 mm. wide. The bridge has a width of 94
mm. The hinder lobe has a width, taken from the ends of the
abdomino-femoral sulci, of 88 mm. Its length is 57 mm.

Some of the sulci of the plastron are very obscure. Cope
was in doubt regarding some of those on the anterior lobe. One
sulcus crosses the entoplastron 37 mm. behind the front of
the lobe. Cope regarded this as the gulo-humeral; the writer regards it as the humero-pectoral.
The area in front of this appears to the writer to be divided on each side into an intergular,
whose extent backward is doubtful, a small triangular gular, and a large humeral. Cope
appears to have been doubtful whether the sulcus behind the scutes, called by the present
writer gulars, continued directly across the front lobe, cutting off intergulars in front, or
turned backward and reacht the sulcus which crosses the entoplastron.

Cope found evidences of a sulcus, his humero-pectoral, which commenct near the axillary
notch, ran forward parallel with the free border of the lobe, then turned inward and somewhat
backward, to cross the midline a little behind the entoplastron. The present writer, examining
the plastron without knowing Cope’s determinations, did not observe such a sulcus. It is
not found on other species of 4 gomphus.

According to the writer’s determinations, the pectoral scutes join along the midline a
distance of §8 mm.; the abdominals, a distance of 26 mm. The femoro-anal sulcus appears to
be where drawn. Cope concluded that inframarginal scutes are present. The writer has no
doubt regarding this.

Dr. George Baur (Zool. Anzeiger, x1, 1888, p. 595) stated that he had examined the
type of this species and regarded it as belonging to the genus 4gomphus. He also informed us
that additional materials existed in the Yale University collection, but nothing further has
been heard of them.

Neural. Length. Width.

4

Www wv
(ees)

a al

Genus ZYGORAMMA Cope.

Characters, so far as known, those of 4docus, except that the hypoplastron sends no
buttress to the costals, but each sends a process into a pit between the seventh and eighth
peripherals. Bones of the carapace and plastron comparatively thin. Costals articulating
with peripherals by suture and gomphosis. Rib-heads feebly developt, except on the first
costals. Surface of carapace striated. Posterior marginal scutes rising on the costal bones
as in Adocus.

Type: Zygoramma striatula Cope.

Zygoramma striatula Cope.
Plate 37, fig. 10; plate 38, figs. 1-3; text-fig. 321.

Zygoramma striatula, Corr, Proc. Amer. Philos. Soc., x1, 1870, p. 5503 Ibid, xu, 1871, p. 44; Vert.
Cret. Form. West, 1875, p. 263.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445-

This species was based on rather fragmentary materials which were collected from the
upper greensand bed of the Cretaceous, at Pemberton, Burlington County, New Jersey.
The remains consist of the greater portion of both hypoplastra, 5 posterior peripherals, and
fragments of 3 costal bones. This type is in the American Museum of Natural History and
bears the catalog number 2358.

The hypoplastrals (plate 38, fig. 1) are thin, the thickness everywhere along the hyo-
hypoplastral suture present being only 6 mm. Near the midline, just in front of the le
with the xiphiplastrals, the thickness is 7 mm., increasing to g9 mm. near the free border,
behind the inguinal notch. -

The sutures are coarse, each bone sending large teeth into pits of the other. _ These pits
and teeth belong to the deeper layers of the bone; while the sutures, as seen from below,

ih

258 FOSSIL TURTLES OF NORTH AMERICA.

form nearly smooth lines. The hy poplastra meet along the midline a distance of 80 mm. The
one of the right side has articulated by its anterior angle with the left hyoplastron for a short
distance. ihe free border of the left hypoplastron is present from the inguinal notch to
xiphiplastral suture. Below, it presents an acute edge; but the bone thickens rapidly. Out-
side of the notch a process is sent outward and upward to enter a pit between the seventh
and eighth peripherals. “The abdomino-femoral sulcus crosses the hypoplastra a little nearer
the anterior end of these bones. The region where we might expect to find the inframarginal
scutes is broken away. The longitudinal median sulcus is not seen.

The sculpture of the plastron is obscure, but there are evidences everywhere of shallow pits,
and these were arranged, at least partly, in rows.

There are preserved the distal ends of 2 costals, one of which is the sixth of the right side,
while the other belongs to the left side. The sixth of the nght side (plate 38, fig. 2) is 38 mm.
wide and 4mm. thick. It is attacht principally to the eighth peripheral, but also to the anterior
angle of the ninth. On the outer surface are seen parts of the third and fourth costal scutes,
and of the eighth and ninth marginal scutes. The other distal end of a costal, probably the
fifth of the left side, is 43 mm. wide and 4 mm. thick. A fragment of a costal from about the
middle of the length of the bone is 35 mm. wide and 6 mm. thick. This seems to indicate
that the costals thickened considerably toward the neurals.

Three successive peripherals of the right side are among the materials, the seventh,
eighth, and ninth (plate 38, fig. 2). They are remarkable for their great height. The seventh
measures 46 mm. along the free border; the eighth and ninth, each 49 mm. The height of
the latter is 65 mm. aa he exterior surface of the seventh is convex, with the free edge flared
slightly upward. The other two are not curved vertically, but are convex from front to back.
The greatest thickness of the ninth is at the front border, 11 mm. The thickness is reduced
upward to the sutural border, less rapidly downward to the sharp free edge. The eighth
thickens rapidly toward the anterior end, where, at the middle of the height, the thickness is
23 mm. The thickening is exprest on the inner surface as a ridge. The hinder and lower
inner portion of the seventh is likewise thickened, but the front and upper part is excavated
by the visceral chamber. Above the thickened ridge, on the inside of each of these peripherals,
is seen the mouth of a deep pit which received the free end of a rib. Two of these rib-ends
are yet in place, one belonging to the sixth costal.

Between the seventh and eighth peripherals, on their inner side (plate 38, fig. 3), there is

a deep pit, excavated principally in the seventh, which has received ie extremity of the
etinal process of the hypoplastron. The latter did not rise to the height of the costal plates.
From the front of the pit a sharp ridge runs downward and forward. This has its inwardly
projecting edge broken away, but it quite certainly furnisht an articulation with the outer
border of the ‘hy poplastron. The seventh peripheral of the left side is present, but furnishes
no additional information. A more posterior peripheral, possibly the eleventh, has the exterior
surface considerably more concave vertically than that of the more anterior ones, showing
that the hinder border of the carapace was flared upward. Plate
37, fig. 10, shows a fragment of a bridge peripheral with a portion
of the end of a rib inserted in a furrow. Text-fg. 321 represents
a section of a bridge peripheral showing that there was a sharp
keel along the side.

As will be observed from the plate, the hinder marginal scutes
extended up on the costal plates. The ninth marginal has a width
fore and aft of 52 mm., and a height of 85 mm. _ Its upper border
displays some of the irregularities so common among the Der-
matemydida. On the costal supposed to be the Gah of the left side the sulcus bdteeen the
marginal and the costal scutes runs lower down.

Fic. 321.—Zygoramma stria-
tula. Section across a
bridge peripheral. 3.

The outer surface of the costals and peripherals is sculptured into low ridges and shallow
grooves. These are mostly directed from the front of the bone backward, but often also
slightly downward. The downward inclination is seen especially on the more posterior bones.

The length of the carapace of this specimen is estimated at 380 mm.

DERMATEMYDID&. 259

Zygoramma microglypha Cope.
Fig. 322.
Zygoramma microglypha, Core, Proc. Amer. Philos. Soc., x11, 1871, p- 445 Vert. Cret. Form. West, 1875,

p. 263.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p- 445.

The remains described under the above name were found at Birmingham, New Jersey,
in the uppermost stratum of Cretaceous greensand. They consisted of the greater part of the
plastron and half of the carapace, with 4 peripheral bones, of an individual whose carapace
must have had a length of about 600 mm. A portion of this material has been recognized in
the Cope collection of reptiles, in the American Museum of Natural History, and this bears
the number 6129. Unfortunately, up to the present time, no bones of the plastron have been
found in the collection. No part of the species has hitherto been figured.

The plastron is described as having a total length of 457 mm. According to Cope’s
measurements, the length of the hyoplastron was 81 mm.; that of the hypoplastron, 145 mm.;
that of the xiphiplastron, 117 mm. The length of the hyoplastron was probably taken along

themidline. The front of the plastron

was truncated. The width of the

entoplastron was 95 mm.; its length

something less; its thickness 11.6mm.

The posterior border was truncated;

the anterior border, regularly convex.

; = The posterior plastral lobe was regu-

Se ‘ ! ; larly contracted, and rounded, and it

/ had a thin edge. Its width at the

| hypoxiphiplastral suture was 220

Gere mm.; the thickness at the midline,
15.8 mm.

The peripheral bones at the
bridges are said to have had a thick-
ened shoulder within, into which the
‘S slender costal processes were received.
The free peripherals were of lighter
construction and somewhat everted.

Most of the bones of the carapace
that have been certainly identified are
here figured (hg. 322). These consist
of a portion of the first neural, the
Fic. 322.—Z ygoramma microgly pha. Portion of carapace third and the fourth neurals, the prox-

: of type. | XH. imal end of the first and third left cos-
tals, parts or wholes of the second,
third, fourth, and fifth right costals,
and portions of other costals whose positions can not be determined.

The first neural has a length of about 57 mm.; its width is 45 mm.; its thickness, 8 mm.
The third and the fourth have each a median length of 60 mm. and a maximum width of
37mm. Each is excavated in front for the preceding neural. Each has a thickness, where
it joined the costal, of 1o mm. The first costal is 80 mm. wide; the second, 56 mm.; the third
59 mm.; the fourth, 55 mm. On the lower side of the first there is the base of a strong rib-
head, and in front of this a rough articulation for the first rib. The rib-heads of the other
costals are very feebly developt.

The sulci between the horny scutes are moderately distinct. The second vertebral had
a length close to 105 mm. and a width about equal to the length. The first vertebral must
have been considerably wider than the second. The third vertebral appears to have had a
length of 115 mm. and a width close to 95 mm.

As in Z. striatula, the marginal scutes extend high up on the distal ends of the costal bones,
as may be seen from the figure. They pursue an irregular course.

ime eal pes ae

5 H

»
4

C. p-1, C. p. 3, ¢. p. §, costal plates; m.1, 7.3, 7.4, neural bones.

260 FOSSIL TURTLES OF NORTH AMERICA.

According to Cope, the intergular scutes formed a single shield, which was large, pentag-
onal, with straight sides, and broader than long. This shield separated widely the gulars
from each other. The pectorals encroacht on the entoplastron; laterally they were narrow.
The abdomino-femoral sulcus crost the hypoplastra a little behind their middle. The median
longitudinal sulcus pursued an erratic course.

This species evidently resembled closely Z. striatula. The distinguishing character most
obvious is the finer and conspicuously punctate sculpture. Cope states that the costal pro-
cesses that fit into the peripherals of Z. strratula are relatively twice as large as those of Z.
mic rogly pha.

In its sculpture this species resembles the species of ddocus.

Genus HOMOROPHUS Cope.

A remarkable, but insufhciently known genus of Dermatemydide. Costal rib-heads
wanting or vestigial. Neurals, in the type and only known specimen, co-ossified with the cos-
tals. The superior face of each neural much wider than the inferior face. Vertebral scutes in
most places narrower than the neurals.

Type: Homorophus insuetus Cope.
Homorophus insuetus Cope

Homorophus tnsuetus, Corr, Proc. Amer. Philos. Soc., x1, 1870, p. 552; Ibid., xm, 1871, p. 44; Vert.
Cret. Form. West, 1875, p. 263.—Hay, Bibliog. and Cat. Poss Vert. N. A. , 1902, p. 446.

The type of this species appears to be lost. It was discovered in the uppermost bed of
Cretaceous greensand, at Pemberton, Burlington County, New Jersey. Cope does not state
what parts of the shell he had, but he describes some neural bones, the entoplastron, the
hyoplastron, the hypoplastron, and some costals. He had neither the epiplastra nor the
xiphiplastra.

The hyoplastron and the hypoplastron together measured 200 mm. along the midline.
On comparing these parts of the plastron with the same parts in Baptemys it is concluded that
the plastron had a length of about 420 mm.

The sutures bounding the neural bones appear to have been obscure. Cope says that one
of the neurals was 14 mm. thick, 60 mm. long, 28.5 mm. wide in front, and gt mm. wide
behind. It is possible that there was here some error in observation or in statement. On the
visceral face the neurals were very narrow, but they expanded, so that a transverse section
resembled that of a broad wedge with truncated apex. The vertebral scutes had a remarkable
form. For the most part, they were narrower than the neural bones. One is described as
having the front cofhn-shaped, the lateral margins concave, and the posterior end expanded,
so thar the scute was fiddle-shaped. The anterior vertebral is stated to have been 60 mm.
long and 35 mm. wide anteriorly. The posterior costal scutes are described as meeting
in the midline behind.

The thickness of the hyoplastron was 15 mm. The free border of the hypoplastron was
thinned to an edge.

Genus ALAMOSEMYS nov.
Differs from ddocus, so far as known, in having the marginal scutes wholly excluded from

the costal bones.
Type: Alamosemys substricta Hay.

The generic name is derived from the name of the stream where the type was found.

Alamosemys substricta sp. nov.

Plate 39, figs. 1, 2; text-figs. 323, 324.

The specimen which serves as the type of this species was collected in the Torrejon
deposits of New Mexico, near the head of Alamosa Creek, in 1896, by Dr. J. L. Wortman
and Mr. W. Granger. It bears the catalog number 1204, in the American Museum.

DERMATEMYDID&. 261

The specimen is a complete shell, extremely little damage having been done to either the
carapace or the plastron through loss of any part. Unfortunately, however, an extremely
compact clayey limestone has envelopt the shell, and this clings so closely to the bone that it
was very difficult to remove it. In addition to this, there had been deposited over considerable
portions of the shell scattered nodular masses of hematite, which became so thoroly
attacht to the bone that, in removing them, the surface of the bone was somewhat injured.
This condition has resulted in making it very difficult to determine the position and courses
of some of the sutures between the ones and likewise the i impressions between the different
epidermal scutes. Many of the bone sutures could be determined only by removing, by
means of hydrochloric acid, a thin layer of bone so that the matrix in the sutures zee!
a little. The obdurate nature of the matrix which fills the shell has seemed to render i
inadvisable to attempt to remove it for the purpose of seeing characters found on the inside
of the shell.

The specimen has been carefully studied and the various sutures and sulci have been
represented in the figures herewith provided. As to the bone sutures, they have been satis-
factorily made out and may be relied upon. Many of the epidermal sulci have been more
dificult to determine; but in general, it is believed that they are correctly mapt.

: rat hod ‘
ee
323 oe —
Ff cas
fe ‘ ;
{ eS ee
| a
ae 9
\ fu /
\ a
Ne eal Ge
oer a We ~
Fics. 323 AND 324.—dlamosemys substricta. Carapace and plastron of type. 4.
323. Carapace. 324. Plastron.

The carapace (plate 39, hg. 1; text-fg. 323) is Aer | moderately elevated, decidedly
constricted at the inguinal notches, and miki the peripherals behind these somewhat flaring.
A remarkable fercure of the shell, shared by ddocus, is the large part of it which lies behind
the sutures separating the third and fourth costal plates seve: and that which separates the
hyoplastrals from the hy poplastrals. Sixty per cent. of the length lies behind the line indicated.
So far as known to the writer, this is approacht only in C ‘ine Ii of living genera. Nearly
half of the entire length lies behind the inguinal note hes.

In front, over the neck, there is an emargination in the border of the shell, while there are
some feeble serrations in the hinder border. The extreme length of the carapace, in a straight
line, is 550 mm. The greatest width, 380 mm., is just behind the inguinal notches; between
the third and fourth costals the width is 372 mm. ‘The greatest depth of the shell is 150 mm.,
but in life this may have been greater. On each side of the middle line of the carapace, for
some distance, the shell is flat, there being no suggestion of a keel. The nuchal bone is 55 mm.
long in the midline; its lateral extent is 53 mm. at the anterior margin; go mm. where widest.
There are 7 neurals. The eighth was wholly supprest; the sixth and seventh were reduced in
size and crowded forward. "The first is broadly oval, 57 mm. long and 32 mm. wide. The
second is narrowly oval, 44 mm. long and 18 mm. wide; the third, nar and fifth are hex-

262 FOSSIL TURTLES OF NORTH AMERICA.

agonal, with the broader end forward; the third being 56 mm. long and 25 mm. wide; the
fourth, 46 mm. long and 22 mm. wide; the fifth, 38 mm. long and 22 mm. wide. The sixth is
hexagonal, 20 mm. long and 28 mm. wide. The seventh neural is pentagonal, 22 mm. long and
17 mm. wide. It has the appearance of having been crowded far forward out of its place.
There is a single broad suprapygal whose length is 46 mm. and width too mm.

The members of the sixth, seventh, endl eighth pairs of costals respectively meet along
the midline. The suture between those of the eighth pair is 82 mm. long. The peripherals
are unusually high, about 100 mm. along the Rides somewhat less coward each extremity of
the animal, the frst and eleventh being Bnet 64 mm. high. The free peripherals are thin at
the borders, and the hinder ones are seduced to a sharp edge. The thickness of the second
peripheral, near the upper border, is 20 mm.; that of the ninth, at the upper border, is 16
mm. There are 11 of these peripherals on each side.

As stated, it is dificult, in a few cases impossible, to determine satisfactorily the bound-
aries of the epidermal scutes. In front there is a very narrow nuchal, about 10 mm. wide
and 20 mm. long. This is followed by a first marginal, 58 mm. along the front edge and
30 mm. fore and aft. The sulci between the marginals and the costal scutes appear to run at
a considerable distance below the sutures between the costal and peripheral bones, the mar-
ginals being about 75 mm. high. The limits of the vertebral scutes are satisfactorily deter-
mined, except those of the fifth. The first vertebral is 80 mm. long and 130 mm. across its
anterior end. The second is 100 mm. long and 65 mm. wide; the third go mm. long and 66 mm.
wide; the fourth apparently 108 mm. long and close to 58 mm. wide. The fifth was probably
115 mm. long and about 130 mm. wide.

The surface of the carapace, including the lower faces of the peripherals, is ornamented
with narrow and low longitudinal wrinkles of which there are from five to eight in a 10 mm.
line. They are possibly “due to the great age of the specimen and may be wanting in the
younger individuals.

The plastron (plate 39, fig. 2; text-fig. 324) is well developt, altho it leaves wide spaces
between it and the carapace. It was apparently quite flat, altho now somewhat concave
transversely, the result possibly of pressure. The total length is 415 mm. The anterior lobe
projects nearly as far forward as the anterior border of the carapace; but the hinder fails to
extend as far backward as the carapace by about 115 mm. The anterior end of the plastron
is very slightly emarginated; the posterior end is broadly rounded and without notch.

The length of the anterior lobe is 100 mm.; its width at the axillary notch 209 mm. It
decreases in widen gradually at first, then rounds rapidly to the notch in front. Its thickness
near the frontisg mm. The length of the posterior lobe is 132 mm.; its width at the inguinal
notches is 1g0 mm. The bridge i is 180 mm. in width. The axillary and inguinal batieeees
do not appear to extend inward beyond the adjacent borders of the plastron.

The entoplastral bone is short and broad and with a nearly straight hinder border. Its
length is 55 mm; its width,go mm. The hyoplastral bones meet along the midline for a dis-
tance of 100 mm. The suture separating the hypoplastrals from the xiphiplastrals is believed
to be placed as shown in the figures. The former bones occupy 135 mm. of the midline; the
latter, 84 mm.

Gular and intergular scutes seem to be present and to have the positions and forms given
them in the figures. The intergular area is evidently divided by a median sulcus. The two
taken together are 75 mm. wide and 50 mm. long. The gulars are small, triangular, and
widely separated by the intergulars.

The humero-pectoral sulcus crosses the midline at the hinder end of the entoplastron.
The humerals meet on the entoplastron for a distance of 48 mm. The pectorals extend
along the midline only 46 mm. Altho the femoro-abdominal sulcus is not as distinct as
might be desired, it is probably placed correctly in the figures. The abdominals thus have a
ee and-aft extent of 128 mm. The femorals extend along the midline 80 mm.; the anals,
67 mm.

On the bridges of the plastron there are at least four inframarginals. Of these, the one
in front is small and square; the second, pentagonal; while the fifth is probably hexagonal.
The third is 95 mm. long and 42 mm. wide, and may possibly be subdivided; but no sulcus
is visible.

DERMATEMYDID&. 263

The surface of the bones of the plastron appears, for the most part, to have been smooth,
but there are some indications of the same kind of wrinkling, or folding, as is seen on the upper
surface. ‘his is especially the case on the bridges and lower ends of the bridge peripherals.

Genus HOPLOCHELYS nov.

Shell thick and solid. Peripherals united to the plastral bones by means of digitations
and dentated sutures; with the costals by gomphosis and in addition by simple apposition or
sutures. Carapace furnisht above with three carina. Plastron with anterior lobe immovable
and with the posterior lobe narrow.

Type: Chelydra crassa Cope.

The characters of this genus are derived wholly from the shell. The plastral structures
are not well known in any of the species. The genus appears to be related to Stauroty pus
now living in Central America. The latter possesses only 10 peripheral bones on each side.
It appears not improbable that H. saliens and H. paludosa, having the peripherals sutured
to the costals, really belong to a distinct genus.

Hoplochelys crassa (Cope).
Plate 38, figs. 4-9; text-fig. 325.

Dermatemys sp., Corr, Proc. Amer. Philos. Soc., xx, 1882, p. 461 (no description).

Chelydra crassa, Cork, Science (1), x1, 1888, p. 198 (no description); Trans. Amer. Philos. Soc., (2,)
Xvi, 1888, p. 306.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 446.

Hoplochelys crassa, Hay, Amer. Geologist, XXXv, 1905, p. 339.

Professor Cope’s first description of this species appeared in the Transactions of the
American Philosophical Society as cited above; but he had previously mentioned it, as early
as the year 1882, as a species of Dermatemys. In no place does this author state the exact
locality or level at which the specimens were found by his collector, Mr. David Baldwin.
However, Cope’s label, which accompanies the type specimen, states that it was found June
6, 1883; and Dr. W. D. Matthew has been able to show from the labels found with the mam-
mals collected by Mr. Baldwin that at that time the collector was in the neighborhood of
Chaco Canyon, San Juan County, New Mexico. Both the Puerco and the Torrejon are
found in that region and it is therefore uncertain to which of these the fossil belongs. Two
other species referred to the genus come from the Torrejon. Cope’s first mention of the
species in 1882 was doubtless based on other specimens, possibly the three neurals of which
he speaks in his description.

Cope states that he possest remains of 2 individuals. Of the first there were present 2
vertebral bones, g peripherals, and 3 plastrals; of the second, 3 vertebrals. The bones of the
first-mentioned individual are now in the American Museum of Natural History and bear the
catalog number 6091; where the remains of the second specimen are is not at present known.

Of the g peripherals in Professor Cope’s possession 4 are represented by only as many
fragments. No neurals are present, but there are 2 fragments of costal plates (plate 38, fig. 8),
which are not mentioned by Cope; unless, indeed, they were mistaken for neurals. A study
of the materials at hand has convinet the writer that Professor Cope was nearer the truth
when he regarded this species as a Dermatemys.

As stated, no neural bones are preserved. The presence of a median keel must rest on
Cope’s statement and on the probability that such a keel would accompany the lateral keels.
The latter were sharply defined (plate 38, fig. 8) and ran longitudinally at a distance of about
10 mm. from the median border of the costal scutes. Along this keel, on the hinder portion
of the costal scute represented, the crest rises but little above the surface of the bone; but
immediately behind the sulcus that separates this scute from the next one there is a sudden
depression of the bone, so that the keel stands up very prominently. As it is followed back-
ward its apparent height diminishes. Where the sulcus crosses the keel the sulcus bends
forward, then again backward, thus forming a sort of loop. One of the costals present 1s 20
mm. wide, the other is 18 mm. The thickness through the keel is 6 mm., but this rapidly

diminishes to about 3 mm. distally. The width of the vertebral scutes can not be determined.

264 FOSSIL TURTLES OF NORTH AMERICA.

It appears probable that the back of this species resembled closely that of Staurotypus tri por-
catus, as represented on plate xxB of Gray’s Catalogue of Shield Reptiles.

None of the peripheral bones at hand show that there was a dentated suture between them
and the costals. Those which articulated with the plastron are thick and heavy. Of these
there were probably 5 on each side. Plate 38, figs. 4, 5, represents one which is regarded as
the sixth peripheral of the right side. It is slightly larger than the corresponding one of the
left side. The length is 22 mm.; the thickness of the hinder end, 17 mm.; that of the anterior
end, 10 mm. The outer surface is strongly convex, and furnisht with a longitudinal sharp
ridge. The anterior portion of the inner surface is concave. Along the lower border of this
face are three excavations for digitations from the hypoplastron. Near the upper border is a
deep cylindrical pit for the extremity of a rib. The hindermost digitation of the hypoplastron
has evidently past on to the next peripheral behind, probably the seventh. Other thickened
peripherals present almost certainly belonged farther forward and received the digitations of
the hyoplastron. Between these and the thickened peripheral just described there was at
least 1, probably 2, thinner peripherals. One of these, the fourth or the fifth, is represented
by figs. 6 and 7 of plate 38. Its length is Ig mm.; its height, 27 mm.; its greatest thickness
g mm. _ Its outer surface is convex perpendicularly, and is traverst by the continuation of the
ridge described as occurring on the thickened peripherals. The inner surface is concave
perpendicularly. In the upper half of this face is a pit for a rib-end; near the lower border
are 3 shallow pits for digitations from the plastral bones. The lower edge was connected
with the plastron by a dentate suture.
This bone or one similar to it was con-
nected partly with the hyoplastron,
partly with the hypoplastron. Each of
these peripherals is traverst by a perpen-
dicular sulcus. Along the upper border
runs a longitudinal sulcus and along the
lower border another, all these forming
the boundaries of the marginal scutes.

Fig. g of the plate cited represents
the pygal bone. Its length is 22 mm., its
height 18 mm., its greatest thickness 8
mm. Perpendicularly the outer face 1s
concave, the inner strongly convex. It
is doubtful whether the upper border
formed a jagged suture with the suprapygal. Another free peripheral, probably the tenth,
resembles the pygal in general features.

Text-fig. 325 represents the left hypoplastron attacht to the seventh peripheral. Near the
hyohy poplastral suture and near the midline the thickness of the bone is g mm.; at the outer
extremity the thickness is 4 mm. At the narrowest portion the width is 11 mm. The
bone was united with the one on the opposite side by a coarse suture; similarly with the
xiphiplastron. With the thicker peripherals it was articulated by means of digitations;
with the intermediate and thinner ones, by both digitations and dentated sutures. A pro-
cess of the xiphiplastron extended along the outer, hinder angle of the hypoplastron.
On the lower surface, between the outer and the middle thirds of the bone there is seen
a shallow sulcus, the inner boundary of an inframarginal scute. Another sulcus begins
at the inguinal notch and runs forward and inward to the meeting of the transverse and
longitudinal sutures.

On the left side of the figure last cited is represented the outer two-thirds of the hyoplas-
tron of the right side. At the narrowest part the bone was 16.5 mm. wide. The bridge was,
therefore, at its narrowest portion, about 27 mm. wide. On the outer end of the bone are sulci
bounding portions of 2 inframarginal scutes. No other sulcus is seen on this bone; and it is
not probable that there was one beginning at the axillary notch and running backward and
inward to meet the one from the inguinal notch, such as we find in C helydra. The whole
arrangement appears to be like that of Staurotypus salvini1, as represented by Dr. Boulenger
in his, Catalogue of Chelonians.

Fic. 325—Hoplochelys crassa. Part of right hyoplastron,
the left hypoplastron, and one left peripheral, probably
the seventh. 3.

DERMATEMYDID&. 265

The xiphiplastra were evidently small bones, but there is no remnant of them preserved.

The width of the shell of this specimen was about 130 mm. An estimate based on the
width of the two costal plates shows that the length was approximately 185 mm. The animal
was therefore somewhat broader relatively than either Stauroty pus salvinii or S. triporcatus.

So far as known, this species differs from H. saliens in having the bones of the plastron
less firmly sutured with the peripherals and in having the latter bones, at least those of the
bridge region, without close suture with the costals. The bridge is much narrower.

Hoplochelys saliens sp. nov.
Text-figs. 326, 327.
The only specimen of this species at present known was found by Dr. ]. L. Wortman

in 1896, at the head of the Escavada Canyon, Rio Arriba County, New Mexico, in Torrejon
deposits. It belongs to the American Museum of Natural History and bears the number

Fics. 326 aND 327.—Hoplochelys saliens. Carapace and plastron of type. 4. Restored

portions in interrupted lines.

326. Carapace. 327. Plastron and part of carapace.

1200. The shell, the only portion preserved, is considerably crusht, but 1s nearly all present.
The only parts missing are portions of the seventh and eighth costals, the hindermost neurals,
and some portions of the plastron. Unfortunately for an understanding of the structure of
the shell much of it was covered by a very refractory matrix, which adhered so closely that it
had to be ground away to the bone. As a result, it is dificult to determine in many places
the position of the boundaries of the scutes and sometimes of the sutures. Most of the periph-
erals, however, have been beautifully weathered out and preserved.

In form the carapace (fig. 326) was oval, rounded in front and behind, and apparently of
some considerable elevation. ‘The total length was close to 325 mm.; the width, close to 200
mm. There was a median keel of moderate height. On each side of this, at a distance of 50

266 FOSSIL TURTLES OF NORTH AMERICA.

mm. in front, 30 mm. behind, there was a more prominent lateral keel. Along none of these
keels was the bone suddenly sunken just behind the transverse sulci, as it is in H. crassa.
In addition to these keels, there is on each side, on the bridge peripherals, a narrow ridge
which passes in front and behind into the free edges of the peripherals.

The rim of the carapace was formed by a nuchal, probably ten pairs of peripherals, and
a pygal. The nuchal is excavated in front for the neck. The width in front is 43 mm,; its
thickness is 11 mm.; its length can not be determined. The first peripheral is 32 mm. long
on the free border and 38 mm. high. The second peripheral is 35 mm. long, concave above,
convex below, and with an acute border. Farther backward this border runs into the rather
sharp keel running along near the upper border of the bridge peripherals. The upper border
of the bridge peripherals is plane, continuous with the surface of the costals, and 10 mm.
or less wide. At the bottom of this surface just above the keel before mentioned run the
sulci separating the costal scutes from the marginals. Immediately below the lateral
keel the peripherals thicken suddenly and form a sort of roll along the shell. The form of
this roll may be seen from the section of the peripheral of the next species, H. paludosa.
The peripherals behind the bridge are slightly flared upward and are acute-edged. The
width and length of the pygal can not be determined. The hinder border of the carapace
was not notcht.

The anterior costal plate had a width of about 50 mm.; the next 3 or 4 pairs, a width of
35 mm. ora little more. The costals opposite the bridges have a thickness of 7 mm. at their
distal ends.

The neurals are broad, and with the broader end forward. The second has a width of
about 35 mm.; the third about the same width; the fourth a width of 25 mm. The boundaries
of those behind these can not be determined. The second vertebral scute has a width of
about 75 mm.; the succeeding ones are narrower.

The anterior lobe of the plastron (fg. 327) is about 100 mm, wide at the base. It appears
probable that the epiplastrals are missing. The entoplastron appears to have the form
and size represented in the fgures. The epiplastra were probably in contact with the outer

border of the hyoplastra as in Stauroty pus salvinii (Boulenger’s Catalogue, p. 31). The bridge

has a width of about 60 mm., a little more than half of which is furnisht by the hyoplastron.

The hinder lobe of the plastron is about 70 mm. wide at the base. The suture between
the hy poplastra and the xiphiplastra was probably where shown in the figures, but this is not
certain. The xiphiplastra probably came to a point posteriorly.

Of Staurotypus salvinit, Sumichrast says (Bull. Soc. Zool. France, 1880, p. 169) that it
lives in muddy pools. Its food consists of small aquatic animals, especially of mollusks
belonging to the genus Ampullaria. Its disposition is voracious and irritable. Its gait on
land is free, and it runs with some swiftness, a fact due to the form of the plastron, which
leaves to the limbs freedom of motion.

The small posterior lobe of the plastron of Hoplochelys indicates that the hinder limbs
were strong and endowed with freedom of movement. Its habits and disposition may have
been not greatly different from those of Staurotypus.

Hoplochelys paludosa sp. nov.
Fig. 328.

This species is based on a single peripheral bone, probably the seventh of the left side.
It was found by Mr. Barnum Brown, in 1904, in Escavada Canyon, New Mexico, where H.
saliens was discovered. It belongs to the American Museum of Natural History and has the
number 6079. It differs from the latter species in lacking the longitudinal ridge along the
convexity of the outer surface of the peripherals, and in having the suture with the costals
much higher above the costo-marginal sulci. In the present species this suture is at a distance
of 20 mm. above the sulcus, while in H. salvens it is only 10 mm. or less. The absence of the
peripheral carina is regarded as an important specific character. The size of the individual
has been probably slightly less than that of H. saliens, the length of the seventh peripheral
of the latter being 35 mm.; of H. paludosa, 32 mm.

|
|
|
|
|

DERMATEMYDID&. 267

From H. crassa the present species differs in having the supposed seventh peripheral
strongly sutured to the contiguous costal bone, in having no lateral carina, and in having the
= r longitudinal sulcus at the middle of the

| height, instead of near the costal border.
| : In the inner face of the bone are excava-
\ tions for the reception of digitations from the
p - plastron. One of these digitations remains in
( position, and shows that it extended backward
\ ye ashort distance intothe eighth peripheral. The
border which articulated with the costals is 7
mm.thick. In the sutural edge is a deep pit, 10
mm.in diameter, which received the extremity
of the rib of the contiguous costal plate.
a, bone seen from side; , anterior end; ¢, posterior end} d, an Fig. 328 shows the type peripheral as

adhering fragment of the plastron. ae 5 pas 5

: seen from the outside. The drawing on the
right presents a view of the hinder end of the bone; the one on the left, the anterior end.

7

a
Fic. 328.—Hoplochelys paludosa. Supposed left
seventh peripheral forming type. *3. A.M.N.H.

Genus KALLISTIRA nov.

Carapace thick and solid; provided with a median and two lateral carina. Plastron
unknown, except that its inguinal buttresses were extensively developt and ascended a con-
siderable distance against the inner surface of the fifth and sixth costals.

Type: Dermatemys costilatus Cope.

Kallistira costilata (Cope).
Pigs. 329-334.

Dermatemys? costilatus, Cope, Syst. Catalogue Vert. Eocene, N. Mex., 1875, p. 36.

Dermatemys costilatus, Cop, Report on Geol. N. Mex., 1874 (1875), p. 96; Wheeler’s Surv. 100 Merid.
IV, pt. il, p. 52, plate xxiv, figs. 17-31.

Baptemys costilatus, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 445.

>

The types of the present species belong to the U.S. National Museum and bear the number
1152. Not all the fragments that Cope fgured are present. Those missing are the originals
of Cope’s figs. 17, 20, 23, 24, 26, and 31. Cope states that he had fragments representing 6
individuals, and that parts of 4 were figured. There appears to be no reason for doubting
that all of these individuals belonged to the same species. Figures of some portions of these
types are here presented. ‘he species was found in the Wasatch beds of New Mexico.

The species is characterized by its thick and heavy shell and the presence of at least 3
carine on the carapace, one running along the midline and one on each side of it.

The fragment which furnisht Professor Cope’s figs. 27 and 28 belongs to the upper end of
a costal, probably either the second or the fourth. Cope’s fig. 27 (fig. 329) is inverted on
his plate. The width of the costal is 20 mm. It is crost by a low keel whose breadth is almost
g mm., but whose elevation is scarcely a millimeter; the thickness of the costal above the carina
being 6 mm., that thru the carina, 7 mm. At the distal end of the fragment the thickness
is 5 mm. This piece of costal presents a part of the sulcus bounding a vertebral scute laterally
and the sulcus running down the costal. These are extremely narrow and shallow. The
longitudinal sulcus is at a maximum distance of 10 mm. from the proximal border of the costal
and above the lateral carina. The vertebral scutes appear to have had a width of about
42 mm. The proximal end of the costal 1s rounded, showing that the lateral borders of the
adjacent neural were concave. Another costal, the one furnishing Cope’s figs. 1g and Iga,
belonged to a smaller individual. The carina is still less conspicuous than in the case of the
one just described. The original of Cope’s fig. 21 (fig. 330) has the carina more sharply
defined and with a width of 5 mm. It is probable that, as suspected by Cope, the carine
were developt on the rear of the animal and disappeared anteriorly.

Fig. 331 represents the original from which Cope obtained his fig. 30. It is a portion of the
distal half of a costal, in all probability the fifth of the right side. The extreme end of the bone

268 FOSSIL TURTLES OF NORTH AMERICA.

appears to be missing. The hgure presents the inner, or visceral, surface. This bone is 4 mm.
thick at its anterior border, but toward the other border it thickens greatly, so that a little
beyond the middle of the width the thickness is10mm. From the line of its greatest thickness
the bone is beveled off on the inner side to its hinder border, and against this beveled surface
the sixth costal has articulated. A strongly developt buttress from the plastron ascended
against the inner surfaces of these two costals at their junction. The scar for this buttress on
the fifth costal here fgured is 20 mm. long. The plastron was therefore articulated with the

331. 330. 329.

Fics. 329-331.—Kallistira costilata. Costals of the type. 1.

329. Proximal end of costal, second or fourth.
330. Proximal end of costal, showing a carina.
31. Distal end of costal, probably the fifth, showing scar
for inguinal buttress of plastron.

carapace in a very different way from that seen in other dermatemyds; and a distinct genus
is indicated,

Portions of 3 neurals are at hand, those represented by Cope’s figs. 18, 22, and 25. The
first-mentioned (fig. 332) has a width of 22 mm., probably belonged well forward, and was
possibly the second. The median carina 1s barely perceptible. No sulcus crosses the portion
present. That part of a neural from which Cope’s fig. 25 was drawn (fig. 3324) is narrow and
devoid of a carina. It is crost near the fracture by a narrow and shallow sulcus. It appears quite
probable that this is the posterior end of the first neural. At its lateral border it is 5 mm. thick.

The neural represented by Cope’s fig. 22 (fig. 333) apparently belonged to the rear of the
carapace, and resembles closely the sixth of Staurotypus saluinit. Its length is 18 mm.;

Fics. 332-334.—Kallistira costilata. Neurals and a peripheral of type. 1.

332, 3324. Portions of two neurals of the type. 332 is Cope’s fig. 18 ;
3324 Cope’s fig. 25.
3. A hinder neural, showing carina. Cope’s fig. 22.
4. A hinder peripheral with a section (a) across it.
greatest breadth about 20 mm.; thickness at the lateral border 4.5 mm., through the carina
g-5mm. The carina is sharply defined and wider in front than behind.

A portion of a hinder peripheral is present, being the original of Cope’s figs. 29 and 29a,
and constituting, according to Cope, a portion of the same individual as those furnishing his
figs. 27 and 30. Cope’s figure is inverted. This (fig. 334) bone has a height of 27 mm. in a
direct line, and a maximum thickness of 7 mm. Its width can not be determined, as the bone
has been broken near the descending sulcus. This sulcus, in contradistinction to those of the
costals and neurals, is broad and deeply and irregularly imprest. Along the upper border of
the bone runs what appears to be the longitudinal, or costo-marginal, sulcus. On the under

DERMATEMYDID&. 269

side of the bone the descending sulcus is narrow and shallow, like those of the costals. This
bone is strongly concave on the upper surface and has an acute free border. It was very
loosely articulated with the contiguous costal; and in the upper border there is a pit for the
extremity of the costal rib. Fig. 334a is a section of this bone.

Professor Cope thought that this species attained about the size of Baptemys wyoming-

é m . . . . * ~ eI o
ensis, but none of the bones described by him indicates a size so great. From the width of the
costal represented by fig. 331 the writer estimates the length of the carapace at something less
than 200 mm.

Genus NOTOMORPHA Cope.

A little-known genus. Anterior, and probably posterior, peripherals with obtuse free
borders. Apparently intergulars large; the gulars small and removed far from the midline.

Type: Notomorpha gravis Cope.

The materials on which the genus Notomorpha was based are in the U. S. National
Museum. In the original description of the genus (Proc. Amer. Philos. Soc., x11, 1872, p. 474)
characters were attributed to it which were derived from bones of the species called in the
present work Echmatemys testudinea. These bones, altho portions of the first costals with
articular scars for axillary buttresses, were supposed by Cope to be xiphiplastrals with scars
for the pubis. On the strength of these, the genus was assigned to the Pleurodira. Cope’s
discovery of his error regarding the character of the plastron, his removal of his species testu-
dinea to Emys, and his reduction of the species N. garmanii to a synonym of N. gravis, left
the latter the type of the genus. This he concluded was also a member of the Emydidz, but
associated with Dermatemys and Agomphus. As the dermatemyd turtles are now regarded as
a distinct family, Notomorpha must be arranged in that family.

As stated above, Cope made his N. garmanii a synonym of N. gravis, a proper course in
case there is only a single species involved; but of this there may be permitted grave doubts.
Of his gravrs he described a hyoplastron and an epiplastral of one individual and a costal of
what was doubtfully another. The costal had a width of 58 mm., which indicated a very large
turtle. Cope at first recognized important differences between the epiplastrals; but later he
considered these of less importance. We may, then, have doubts regarding the specific iden-
tity of the two lots of bones. Besides this, the materials figured all belong to his N. garmanit.

Notwithstanding all this, until future discoveries shall have thrown additional light on
Notomor pha, it will be best to place the few known remains under the specific name gravis.

Notomorpha gravis Cope.
Figs. 335) 336.

Notomorpha gravis, Cope, Proc. Amer. Philos. Soc., x11, 1872, p. 476.

Notomorpha garmanit, Cope, Proc. Amer. Philos. Soc., x11, 1872, p. 477.

Emys gravis, Cope, Sixth Ann. Report U. S. Geol. Sury. Terrs., 1872 (1873), p- 626.

Notomorpha gravis, Cope, Vert. Tert. Form. West, 1884, p. 143, plate xxiii, figs. 14-16.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 448.

The bones on which Notomorpha gravis was based appear to have been lost. Those
which Cope described as N. garmanii are now in the U. S. National Museum, some of these
bearing the number 4103; others, belonging apparently to the same individual, have the
number 4129. It is not known whether all the bones accompanying the figured specimens
belonged to the same individuals or even the same species. We shall have to regard as types
the remains which were figured by Cope. All three of these are numbered 4103. The bones
originally described under the two specific names had been discovered in the Wasatch beds
at a point near Bear River, 6 miles north of Evanston, Wyoming.

The bone which was regarded as characteristic of Notomorpha is the supposed epiplastron,
the subject of Cope’s fig. 14, plate xxiii, of his work on The Vertebrata of the Tertiary For-
mations of the West. The writer has been unable to convince himself that this is the epi-
plastron, altho it may be such. It may bea first peripheral. The upper border of the original
of Cope’s fig. 14, which was supposed to be the front of the lip, has the appearance of having

279 FOSSIL TURTLES OF NORTH AMERICA.

been a sutural edge for articulation with another bone. The border between the supposed
gular scutes is broken off. If the bone is an epiplastron it must once have projected con-
siderably at this point, and the front of the anterior lobe was deeply emarginated. The length
of the bone is about 40 mm.; its thickness behind is 1r mm. In case the bone is an epiplastron,
the lip was about 40 mm. wide. The free border of the bone, that represented by the right
side of the figure, is thick and obtuse. That of the same bone in Cope’s type of N. gravis, as
originally described, was acute. In his last description of these bones this difference appears
to have been thought of no specific importance. On the supposed under side of the bone are
seen distinct sulci, indicating the supposed intergulars and the small triangular gulars. If
such they are, affinity with the Dermatemydidz 1s indicated. Whether or not the “intergular
was divided at the midline we can not determine.
Fig. 3 335 represents the third left peripheral (No. 4129, U.S. N.M.) seen from above,
while fig. “336 presents a view of the sutural end which joins the second peripheral. It is seen
that the free border is obtuse. The costo-marginal
sulci ran along not far below the upper margin of the
bone. The bone is 39 mm. high, 36 mm. along the
free border, and 18 mm. thick. Cope figures 2 periph-
erals, but the free borders were missing in both.
Cope’s fig. 15 is said to represent the posterior
edge of the eighth peripheral of the right side; but it
belonged to the left side. This bone was somewhat
336. recurved; its height is about 44 mm.; its length on
the free border 35 mm.; its thickness about 9 mm. at
the border represented. The articular border for
union with the costals was thin.
The seventh peripheral (Cope’s fig. 16) is stated
to have been 42 mm. wide, 45 mm. high, and 15 mm.
thick. This peripheral, the seventh of the left side,
entered into the inguinal notch. Its free border was acute; its upper articular border was thin.
Besides these peripherals, Cope had others belonging to the bridge region. These he states
had very obtuse free borders. The general massiveness of these was in contrast with the thin-
ness of the costals. The surface of the peripherals is said to have been obsoletely rugose.
A vertebral bone is stated to have been 7 mm. thick.

FIGs. 335 AND 336.—Notomor pha gravis.
View of third left peripheral of the
type, with section. x8.

335- Peripheral seen frorn without.
336. Section at anterior end.

Genus BAPTEMYS Leidy.

Plastron united with the carapace by means of sutures and by axillary and inguinal
buttresses, which rise to the lower borders of the costals or beyond. Plastral lobes short and
narrow, the hinder not notcht. Nuchal bone with short costiform processes. A full set of
neurals. Marginal scutes not encroaching on the costal bones. Intergulars, gulars, and
humerals of each side usually consolidated into one scute. Inframarginals present.

Type: Baptemys wyomingensis Leidy.

This is the only genus of the Dermatemydide which possesses a full series of neurals.
The pectoral scutes appear to have extended themselves forward to the epiplastrals and even
further. The region which in Adocus is occupied by the intergulars, gulars, and humerals of
each side presents usually only a single scute; but in a specimen of B. tricarinata (fig. 348) the
gulo-humeral sulcus is partly dev elopt.

This genus is represented by 3 known species. Of these, one, B. fluviatilis, comes from
uncertain locality and level. Of the others, B. tricarmata belongs to the Wind River beds,
while B. wyomingensis is common in the Bridger beds of southwestern Wyoming.

Baptemys wyomingensis Leidy.
Plate 37, figs. 11-13; plate 38, fig. 10; plate 40, fig. 1; plate 41, figs. 1, 2; text-figs. 337-345.

Baptemys wyomingensis, Letny, Proc. Acad. Nat. Sci. Phila. 1870, p. 5; Ann. Report U. S. Geol. Surv.
Wyoming, etc., 1870 (1871), p. 3673 ee Report U. S. Geol. Surv. Montana, etc., 1872, p. 367;
Contrib. Ext. Fauna West Terrs., 1873, pp. 157, 340, plate xii, plate xv, fig. 6—Cope, Ext.

DERMATEMYDID&. 271

Batrach. Reptilia, Aves N. A., 1869 (1870), p. ii Hay » Bibliog. and Cat. Foss. Vert. N.A., 1902,
p- 445; Amer. Jour. Sci. (4), XVII, 1904, p. 265, plate xiii, Ags. 1-3, text-fig. 2; Amer. Geologist,
XXXV, 1905, Pp. 331

Adocus vyomingensts, Core, Ext. Batrach., Reptilia, Aves N. A., 1870, p. 233; Proc. Amer. Philos. Soc.,
XI, 1870, p. 297.

ernciergs wyomingensis, Cope, 6th Ann. Report U.S. Geol. Sury. Terrs., 1872 (1873), p. 624; Amer.
Naturalist, xv1, 1882, p. gt, fig. 9.

Dermatemys vyomingensts, CoPE, Vert Tert. Form. West, 1884, p. 142.

Baéna ponderosa, Corr, 6th ‘Annt Report U.S. Geol. Surv. Terrs, 1872 (1873), p. 624.

Baéna? ponderosa, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1903, p- 438.

The type of the present species belongs to the Academy of Natural Sciences at Phila-
delphia. The specimen was obtained somewhere in the neighborhood of Fort Bridger,
Wyoming, from which locality probably all the known specimens have been derived. The
level is therefore that of the lower portions of the Bridger beds. Of the type, some of the
peripherals are missing, also the front of the plastron. "The total length of the carapace in
life was nearly 450 mm.; the breadth, about 310 mm. On the hinder third of the carapace
there is a prominent carina, the summit of which is flat. The anterior neurals are considerably
longer than wide, with the broader end directed forward. The free borders of the anterior
peripherals are thickened and obtuse. The surface of the carapace is mostly smooth, but pos-
teriorly somewhat corrugated. The dimensions of the vertebral scutes are given in the table.

The plastron is relay ely small, and

eee Mealectwaad VERA large spaces are left between it and the

type. A.M.N.H. 1494: A.M.N.H. carapace, thus favoring the movements

a S ~ of the legs. The anterior lobe is 148
| No. Length.Width. No. Length. Width. No. Length. Width. mm. wide at the base. The bridge has a
se ail" a width of 105 mm. The hinder lobe ter-
| minates obtusely behind. The length is
| 104 62

jy a 81 108 I 50 22 I 68 go
| 2 2 2 | 22 2 85 33 94mm.; the width at the base, 115 mm.
3 9° 68 2 45 21 3 83 55 On each of the bridges are 3 inframar-
4 79 66 4 40 22 4 86 60 : :
| 5 ie 5 : 23 H 110 ~—10_:~«|s gall scutes. Of these the hindermost
6 37 28 extends forward on the hyoplastron.
i ie Dr. Leidy described a second spec-

; imen which had been discovered at

- Church Buttes. This shell was impor-
tant because it furnisht the front of the plastron, which Leidy figured in his Contributions
(plate xv, fig. 6). This front, however, differs so much from that of all others found since,
that there is some reason for suspecting that it belongs to a distinct species, being truncated
and notcht in front. Below some details are given regarding this specimen.

In the Cope collection belonging to the Mince Museum of Natural History is a large
specimen which presents the carapace (plate 40, fig. 1; text-fig. 337); but of the plastron there
is only the impression of the hinder lobe on the matrix. The catalog number is 1494. Were
it not that Cope describes the form of the anterior lobe, it might be supposed that it 1s the
specimen mentioned by him in the Proceedings of the American Philosophical Society (vol.
Xi, p- 297). Lt is possible that that author did not intend to state that his specimen possest
this lobe, but referred to what Dr. Leidy had determined. The total length of the carapace is
435 mm., in a straight line; the width is 283 mm.; and the height, about 180 mm. The
specimen is remarkable for its narrowness. The anterior edge is thickened and rounded like
the edge of one’s little finger. The thickness of the first peripheral is 16 mm. The hinder
free borders are also obtuse, but much thinner, the thickness near the edge of the tenth being
7mm.; but this increases to 14 mm. at half the height of the bone. The neurals are narrow.
The dimensions of the neurals and the vertebral scutes are presented in the table above.

There are 12 pairs of marginal scutes. The costo-marginal sulcus runs considerably below

227

the oe -peripheral suture. There appears to be present a ninth pair of costal plates (fg. 337,

z Pf 9): - . - 1
The American Museum expedition of 1903 secured 2 specimens of this species at Grizzly

Buttes. These have the catalog numbers 5934 and 5967. No. 5967 presents a large portion

2/2 FOSSIL TURTLES OF NORTH AMERICA.

of the skull. The shell of both specimens is quite complete. In neither is the front of the
plastron truncated. The length of the carapace of No. 5967 (plate 41, figs. 1, 2) was originally
close to 430 mm.; its width about 330 mm.; but the shell has been strongly crusht down-
ward. The first vertebral scute has a width anteriorly of 80 mm.; the next three, each a width
of about 56 mm.; the fifth, a width of 128 mm. posteriorly. It will be observed that the last
of these vepeebials | is considerably wider than in the Cope specimen. On the hinder half of
the carapace there is seen, on each side of the vertebral scutes, an indistinct flattened carina.
These correspond to the much more prominent lateral keels seen in the predecessor of this
species, B. tricarinata.

The anterior lobe of the plastron is 100 mm. long and 152 mm. wide at the base. The
lateral borders converge in nearly straight lines to opposite the front of the entoplastron;
then they round rapidly to the midline. The entoplastron is large, 62 mm. long and 67 mm.
wide. The bridge is 117 mm. wide. The hinder lobe is 92 mm. long and 130 mm. wide at

Fics. 337 AND 338.—Baptemys wyomingensis. Carapace and plastron.
337 5 3 i) &

337. Carapace. X4. No.1494A.M.N.H. c.p.9, probable ninth pair of costal bones.

338. Plastron and border of carapace. 4/5. Specimen in Yale University.
the base. As in other known specimens, the intergulars, gulars, and humerals appear to have
coalesct. “The humero-pectoral sulcus crosses the entoplastron a little behind its middle, and
on the hyoplastron it turns abruptly forward and outward. The anal scutes measure 51 mm.
on the midline. Each of the other pairs measure about 62 mm. On each bridge there are 3
inframarginals, as in the type of the species. The hindermost one is 110 mm. long on its
outer border.

The specimen numbered 5934 differs from the one just described in having the first
vertebral scute unusually wide, 125 mm. The lateral borders of the anterior lobe of the
plastron are not so straight as in No. 5967 and the extremity is slightly more pointed. The
inframarginals are as in the latter. This specimen shows well fhe buttresses. The axillary

DERMATEMYDID. 273
bones ascend to the borders of the first costals. The inguinal buttresses do not reach the
upper borders of the peripherals.

At Yale University is a specimen (No. 484) which was collected in 1870, at Millersville,
Wyoming, therefore in the lower third of the Bridger deposits. It furnishes a crusht carapace
and a complete plastron (text-fig. 338), the nearly complete skull (plate 37, figs. 11, 12, 13),
and portions of limb bones. The carapace has a length of 445 mm. and a width of 330 mm.
There is a large suprapygal 45 mm. long and 70 mm. wide. The first vertebral scute is 100
mm. wide; the second, 52 mm.; the third, 50 mm.; the fourth, 66 mm.; the fifth, 95 mm.
Besides these normal vertebrals there is a small supernumerary one, 37 mm. long, cut off from
the front of the normal fifth. The plastron (fig. 338) is 305 mm. long. As will be seen from
the figure, there are on each bridge 4 inframarginals. A small one appears to have been cut
off from the anterior end of the large third one of other specimens. In this specimen the
anterior extremity of the plastron comes forward as far as the front of the carapace; but this
is doubtless due to crushing.

A specimen at Princeton University, No. 10074, is half as high as long.

Dr. Leidy’s second specimen, the one which furnisht the truncated anterior lobe of the
plastron, is in the U. S. National Museum and has the number 5000. In all respects, except
the form of this lobe, the specimen agrees with typical specimens of B. wyomingensis. The
plastron alone is represented and of this a portion of the hinder lobe is missing. The length
of the anterior lobe is 93 mm.; its width at the base 145 mm.; width at the epiplastral sutures,
114mm. The entoplastron is 76 mm. long and 64 mm. wide. The width of the bridge is 108
mm. The hinder lobe has a width of 108 mm., diminishing in a curve to a width of g6 mm.
at the hypoxiphiplastral sutures.

Materials for the study of the skull are furnisht by the specimen at Yale University,
bearing the number 484 (plate 37, figs. 11, 12, 13), and by number 5967 of the American
Museum of Natural History (plate 38, fg. 10). Each of these skulls is accompanied by its
shell. There appear to be no specific differences between them. The Yale skull is nearly
complete, the only portions missing being the roof of the orbits and of the nasal cavities.
The American Museum specimen supplies the parts missing in the Yale skull; but it is
defective in many respects. That at Yale furnishes the description here given, unless other-
wise specified.

Relatively to the size of the shell the skull is small. It is broad behind and tapers forward
to a rather narrow snout. The length, from the snout to the occipital condyle, is 67 mm.; to
the extremity of the supraoccipital spine, 88 mm. The greatest width, taken at the upper
borders of the tympanic cavities, is 58 mm. The temporal region is not rooft over, and there
is no parieto-squamosal arch. The postorbital arch is slightly more than 7 mm. wide. The
zygomatic bar is deeply excavated on its lower border, and is 10 mm. wide. At the hinder
border of the orbit, where the maxilla joins the jugal, the former bone is only 5 mm. wide.
The interorbital space, as shown by the American Museum specimen, has a width of 23 mm.
The orbits are placed well forward. The antero-posterior diameter of each was about 20 mm.;
the perpendicular, 17 mm., the latter dimension being furnisht by the American Museum
specimen. This individual also shows that the nares had a perpendicular diameter of 11 mm.,
a transverse diameter of 16 mm. The upper jaw is convex on its lower border, rising in front
so as to form a median notch. This upper jaw, as shown especially by the American Museum
specimen, has a sharp cutting-edge, but no masticatory surface. This appears to be an indi-
cation that this animal was not accustomed to crush shells, or other hard substances, but to
live on more active prey.

The tympanic cavity has the longest diameter directed upward and slightly backward;
its outer rim is thick and heavy. The posterior wall is open, forming a notch for the passage
of the stapedial rod. The sutures between the bones of the skull are close and some are to be
traced only with difficulty. There seem to have been no nasals. As shown in the skull
belonging to the American Museum, the prefrontals run backward over the orbits and join
the postfrontals, excluding the frontals from the boundary of the orbit. From the individual
just mentioned the postfrontals are missing, but the sutural borders of the frontals and of the
parietals articulating with the postfrontals are well preserved. The jugal is a bone of con-
siderable length, and it forms a large part of the lower border of the orbit.

18

274 FOSSIL TURTLES OF NORTH AMERICA.

The choanz are far forward. The roof of the mouth in front is vaulted, not greatly unlike
that of a Testudo. The yvomer apparently extended between the palatines to the pterygoids
or very close to them. The distance across the palatines, at their hinder ends, is 20 mm,
The distance across the constricted portion of the pterygoids is 13 mm. There are posterior
palatine foramina. The lower jaw, as shown by the American Museum specimen, had a
single sharp cutting-edge, which workt against that of the upper jaw. The lower jaw appears
to have formed a beak in front. The symphysis is short, about 12 mm. in length. The jaw is
20 mm. high at the coronoid region.

The right humerus is present in the Yale specimen, and complete except that the radial
tuberosity is broken off. The length from the proximal surface of the head to the distal end
is 83 mm. The greatest diameter of the head is 21mm. The ulnar tuberosity is as large as
that of Chelydra. The angle between the two tuberosities is nearly the same as in Chelydra.
The ectepicondylar foramen also resembles that of the genus just named. The distal articular
surface appears to have been bent toward the palmar surface more than in Chelydra. The ulna
is like that of Chelydra, but is, relatively to the length of the humerus, longer than in the genus
named. It is likewise thicker from the dorsal to the palmar surface. The length is 55 mm.;
the least breadth, 8 mm. The distal end is 19 mm. wide. The dorsal surface is strongly
markt by ridges for the attachment of muscles. About two-thirds of the radius is preserved.

Some portions of the hinder limbs are preserved, wholly or partly; but they have not been
completely removed from the matrix. The right astragalo-calcaneum was found in the right
axillary notch. It resembles that of Chelydra, but has the fibulare co-ossified with it.

The vertebra are represented by portions of two cervicals, but they furnish us little
information. One lies against the head of the humerus and presents a cup-shaped articular

cavity. The centrum is 1g mm. wide,

and there is a sharp median carina on
34. its lower surface. One complete toe
is present (fig. 339). It was found in
the right axillary notch; but from the
length of the phalanges and the fact
that the right astragalo-calcaneum
was found close to it, it is concluded
that it is one of the digits of the hin-
der limb.

No. 5934 of the American Muse-
um furnishes some fragments of the
cervical vertebra. One of these, a

339- Digit belonging to specimen of fig. 338. Xt. posterior one, shows that on the under

a eee See ae X#%. No. 5934 A. M.N. H. side of the Eon there was 2 sharp

; = a and prominent carina. The anterior
end of the centrum has right and left articular cavities. A posterior caudal has the centrum
17 mm. long. The total height of the centrum and the arches is 23 mm. The centrum is
proceelous. The ulna is represented by fig. 340. It resembles that of Chelydra, but it is rela-
tively broader and the radial border is thicker. Fig. 341 represents an ungual phalanx and
the one preceding it. A considerable portion of the pelvis is preserved (figs. 342, 343). The
upper end of the ilium is missing, but it was probably not broadened. On its anterior border,
half the height above the acetabulum, is a strong process directed outward and forward. The
pelvis resembles that of Testudo. The ischial symphysis is 13 mm. thick. There is a long
antero-lateral pubic process. The pubic symphysis was more than 23 mm. long.

Dr. Leidy’s second specimen, in the U.S. National Museum, furnishes the right scapula.
This is represented as seen from behind and of two-thirds the natural size by fig. 344. The
height of the body above the glenoid fossa is 102 mm; the proscapular process is 54 mm. long.

Professor Cope described from Ham’s Fork, Wyoming, a species which received the name
Baéna ponderosa. The specimens are now in the U. S. National Museum, at Washington,
where the writer has twice examined them. Cope states that his figures are three-fifths the
size of nature; but the measurements show that they are only half that size. Cope’s fig. 5
represents the first and second right peripherals. The suture between the two is not well

340.

Fics. 339-341.—Baptemys wyomtingensis. Limb bones.

DERMATEMYDID&. 275

shown in the figure. His fig. 4 represents the second left peripheral. Fig. 8 is from a portion
of the left first costal and its median notch fits accurately on the upper border of the original of
his fig. 4. Cope’s fig. 6 is almost certainly that of the right third peripheral. In the collection
there are present the left second and third peripherals of another individual. These bones cer-
tainly do not belong to any species of Baéna. They closely resemble those of Baptemys wyo-
mingensis, and in all probability belong to that species. : F
Cope’s assignment of these bones to Baéna was determined by the bone represented by
his fig. 3. It is indeed very peculiar. Fig. 345 represents a section. Cope regarded it as form-

Fics. 342~345.—Baptemys wyomingensts. Pelvis, scapula and peripheral.

342- Pelvis, from left side. 3. No. 5934 A. M.N.H. fl, ilium; isch, ischium; pub, pubis.

343- Pelvis of individual of fig. 342. Seen from below. 3. il, ilium; isch, ischium; pub, pubis. The suture
between the right and left pubes ran from a point 2 mm. on the left of the leader from pub backward to
a point 2 mm. on the left of the line of two short dashes.

344. Scapula. 3. Specimen in U.S.N.M.

345. Section of peripheral described by Cope as that of Baéna ponderosa. X34.

ing a part of the hinder border of the carapace, the scute seen on it being the hindermost
one. However, the writer has found in the collection another fragment which continues the
border 5 or 6 mm. toward the left, and on it begins another marginal scute. It is the writer’s
conclusion that this bone also belongs to Baptemys and is a malformed portion of the hinder
border of the carapace.

Baptemys tricarinata sp. nov.
Figs. 346-349.
Dermatemys——, Cope, Bull. U. S. Geol. and Geog. Surv. Terrs., v1, 1881, p. 184.

Remains belonging to 2 individuals of the present species were collected in the Wind
River deposits, during the summer of 1905, by the expedition in charge of Mr. Walter Granger,
of the American Museum of Natural History. One of these, No. 6109, was found at the
mouth of Alkali Creek, Fremont County, Wyoming; the other, No. 6110, on the divide
between Alkali and Poison Creeks. No.6109 is made the type of the species. Both specimens
are considerably fractured, neither of them furnishing a complete carapace. Taken together,
however, the two specimens give practically the whole structure of the shell. The species is
distinguisht from B. wyomingensis by the possession of three dorsal carina and a pointed
hinder plastral lobe.

The carapace of No. 6109 (fig. 346) has an approximate length of 460 mm.; a width of
about 330 mm. Its structure differs only in minor points from that of B. wyomingensis. The
neurals are long and narrow. The peripherals differ little from those of the Bridger species,

276 FOSSIL TURTLES OF NORTH AMERICA.

except that they, like the other bones of the carapace, appear to be somewhat thinner. The
vertebral scutes are perhaps relatively a little wider than in B. wyomingensis. There are 3
broad dorsal carina—a median and two lateral. The median may be traced farther forward
than in B. wyomingensis, as far forward as the front of the third neural. The lateral carine
run just outside of the vertebral scutes. They are of moderate height posteriorly; on the

Fics. 346 AND 347.—Baptemys tricartnata. ie and plastron of type. 4.

346. Portion of carapace. c. p.1, first costal plate; 7.1, 1. , first and eighth neurals.
47. Plastron and portion of carapace.

anterior half of the carapace they may be traced to the first costal; but on the three anterior

costals they form very low ridges.
Fig. 347 represents the lastron. The total leneth is 285 mm. The anterior lobe is broad
347 rep P : ig 5 : )
enindea: and slightly notcht in front. The length is g2 mm.; the width at the base, 148 mm.
The entoplastron i Is larger than in B. wyominge nsis, being 65 mm. long and 75 mm. ae The

349.

Fics. 348 AND 349.—Baptemys tricarinata. Plastron and humerus of type. 4.

348. Anterior lobe of plastron. 349- Right humerus.

bridge is 93 mm. wide, relatively narrower than in the Bridger species. The hinder lobe is
105 mm. long and 111 mm. wide at the base. The sides converge backward to a point.

The panel areas are represented in fig. 347. No gulars are markt out; but there is a notch
in the border of the epiplastron, as if for the crossing of the gulo-humeral sulcus. There are
on each bridge 3 inframarginals like those of most specimens of B. wyomuingensts.

ay $i

DERMATEMYDID&. 277

No. 6110 has been a slightly smaller individual. Fig. 348 represents the front lobe of the
plastron. It is somewhat more pointed in front than that of the type. What is most interesting
is the presence of portions of the gulo-humeral sulci. The extent and positionof these are shown
in the figure. The presence of these indicates that there has occurred in this genus a coales-
cence of the gulars and the humerals.

Fig. 349 represents the right humerus seen from the dorsal surface. The general form is
that of the humerus of Chelydra.

Baptemys fluviatilis sp. nov.

Plate 42, figs. 1, 2; text-figs. 350, 351.

This species is based on a chelonite which was presented to the American Museum of
Natural History by Mr. Sidney Dillon, of New York City, in 1879. It is said to have been

obtained by him in Colorado, but there is no record of the exact locality, nor of the formation

a

ax

/ A fe
ay | ,

\

Ss

i Lx i * 7
Pare pp eae ;
| ; : yr
x

f “4 oh
> Boa 1 —< \ See

Ww
WwW
a

350.

L

Fics. 250 AND 261.—Baptemys fluviatilis. Carapace and plastron of type. 4.
3 35 pd P P YE 4
350. Carapace. Restored costal and vertebral scutes indicated by interrupted dotted bands. 351. Plastron.

from which it was derived. The specimen probably belongs to the Bridger formation and
there may be some error regarding the region.

The specimen consists of a mass of gray sandstone, broken into two pieces, which bears
considerable portions of the carapace and impressions of other portions and a fragment of the
plastron, together with an impression of the inner surface of practically the w hole plastron.
While we must regret the absence of many parts which might evidently have been preserved,
there is enough of ae shell present to furnish us with the eeecntials of the structure.

This shell has a length of 438 mm. and a width of 312 mm. The carapace (plate 42, fig.
text-fig. 350) forms a high vault which rises from the lower surface of the plastron een

278 FOSSIL TURTLES OF NORTH AMERICA.

160 mm. On the anterior portion of the carapace there is no median carina, but one of some
prominence begins on the sixth neural and continues to the end of the shell. Just above the
pygal plate this carina swells out into a considerable protuberance. The margin of the car-
apace is nowhere reverted, except slightly so behind the posterior legs. There is a slight
notch in the shell just over the tail. Whether or not the edges of the rear of the carapace were
to any degree serrated can not be determined with certainty, but they probably were not.
Anteriorly the edge of the shell is smooth; over the neck the carapace somewhat exca-
vated; the plastron relatively small. The lobes, especially the hinder, leave large spaces
between the upper and lower parts of the shell. The bridge is narrow antero-posteriorly.

The shell is rather thin in the dorsal and costal regions, from 4 mm. to 6 mm., but thickens
toward the margin, the last peripheral being about 10 mm. thick. The surface of the carapace
is usually smooth.

In the middle line of the carapace we find, behind the nuchal, 8 neural plates and 2 supra-
pygals and the pygal. The first neural is of elongated oval form. The others, from the second
to the sixth, inclusive, are elongated hexagonal, with the broad end in front. The following
table gives the dimensions of the nuchal, the neurals, the two suprapygals and the pygal.
There are added the dimensions of B. wyomingensis, reduced to millimeters, from Leidy.

The peripherals are high, the
first being 55 mm.; the fourth, 62
Baptemys Baptemys mm.; the tenth, at least 72 mm.

ee fluviatilis. wyomingensis. The plastron (plate 42, fig. 2;
(an eae text-fig. 351) is the most interesting
| Length. | Width. | Length. | Width. | and instructive portion of the shell.

= ==|- = : ————— Since all but a mere fragment of it
Nuchal..es.ccccceeeeeee| 63 98 | 70 95 is peeled off the matrix, we must
Neural 1.........---- 60 3° as 27 depend on the impressions left on

a See a aa ne 54 the rock. As to the general form and

rR eee Se | ai {3 a 30 most of the sutures, there can be no

peta} 38 t a - i doubt. Its length was 282 mm.

See aS 31 oe 36 The anterior lobe was 100 mm.

Sissdaseet cee 27 31 15 25 long, 138 mm. wide; the posterior
i SS a < me 3° lobe 79 mm. long, 112 mm. wide at
Pygal...... Bee ee ttes i 56 Pane oe the base. No trace is found of the

hyohypoplastral suture; 212 mm.
behind the front end of the plastron
is seen the very plain impression of the hypoxiphiplastral suture. It runs outward to near
the border of the plastron, then outward and forward, and finally turns abruptly backward to
the border. We must, however, remember that we are viewing the upper surface of the plastron,
and that these angulations represent processes of the bones. The xiphiplastrals had a length
of 72 mm. and a width of 100 mm. in front.

There are very distinct impressions of the suture of the entoplastron and of the epiplastra.
The former was, on its upper surface, approximately circular, with a median lobe in front and
a narrow prolongation behind. Its length was 75 mm., the width, 55 mm. The hypoplastra
have a length of 45 mm. along the midline.

The sulci are broad, but often extremely obscure; especially those which separate the
vertebral scutes from the costals. The marginal sulci are usually sufficiently distinct. The
transverse sulci of the vertebrals may be made out satisfactorily. As to the width of the ver-
tebrals, the drawing indicates the position of the lateral sulci as well as the faint indications
will permit. The marginal scutes did not rise on the sides as high as the peripheral bones.
There appear to have been axillary and inguinal scutes. In B. wyomingensis there is a com-
plete row of inframarginals.

This species differs in various particulars from B. wyomingensis. Some differences appear
in the hinder neurals. There are in B. fluviatilis two suprapygals; in B. wyomingensis,
three. It will be observed from the measurements that the hindermost suprapygal is nearly
three times as wide as that of B. wyomingensis. There are obvious differences in the plastra,
that of the present species being more pointed behind.

DERMATEMYDID#. 279
Genus ANOSTEIRA Leidy.

Plastron articulating with the carapace by sutures. Plastral bones 9, the entoplastron
lanciform. Hinder plastral lobe small. Nuchal bone without costiform processes. Ten pairs
of peripherals; 8 pairs of costals; 7 neurals. The eighth pair of costals meeting on the mid-
line. Epidermal scutes developt at least on the carapace. The vertebrals greatly modified.

Type: Anosteira ornata Leidy.

Dr. Leidy did not definitely refer this genus to any family, but regarded it, with Baéna,
Chisternon, and Baptemys, as apparently intermediate to the Pleurodira and the Chelydride
(Contrib. Ext. Fauna, etc., p. 341). Cope (Amer. Naturalist, xv1, 1882, p. 990; Vert. Tert.
Form. West, 1884, p. 112) arranged the genus under the Chelydride; but in the same family
in close relation with Anosteira he included also Claudius. He arranged Dermatemys among
the Emydide. Baur (Ann. Mag. Nat. Hist., ser. 111, 1889, pp. 58, 27 6; Proc. Acad. Nat. Sci.
Phila. 1891, p- 420) favored placing it with either Staurotypus or peter ae according as
the entoplastron might or might not be found to be present. Mr. Lydekker (Cat. Foss. Rept.,
ut, 1889, p- 143) places the genus in the subfamily Anosteirinz under the Chelydrida. Hay
in 1902 (Bibliog. and Cat. Foss. Vert. N. A., p. 446) raised this group to family rank, but this
had already ee suggested by Baur.

The nearly complete shell described below, presenting as it does the entoplastron, enables
us to refer the genus definitely to the Dermatemydidae. The plastron resembles closely that
of Stauroty pus Seah. The presence of the costiform processes in the living members of the
family are not regarded as being of essential importance.

There can be hardly any “doubt that Pseudotrionyx Dollo, of the Middle Eocene of Bel-

gium, is a genus closely related to Anosteira.

Anosteira ornata Leidy.
Plate 43, figs. 1, 2; text-figs. 352-354

Anosteira ornata, Leipy, Proc. Acad. Nat. Sci. Phila. 1871, p. 102; Ann. Report U. S. Geol. Surv.
Montana, etc., 1871 ‘(187 2), p- 370; Contrib. Ext. Fauna West. Terrs., 1873, pp. 174, 341, plate xvi,
figs. 1— ~6.-Hay, Bibliog. and Cat. Foss. Vert. N. A. 1902, p. 4473 Bull. Amer. Mus. Nat. Hist.,
XXII, 1906, p. 157, hes: 25.3:

Anostira ornata, Cope, Ann. Report U. S. Geol. Sury. Wyoming, etc., 1872 (1873), p. 621; Amer. Nat-
uralist, Xvi, 1882, p. 989, fig. 7; Vert. Tert. Form. West, 1884, p. 128.—Do to, Bull. Mus. Roy.
Belgique, 1v, 1886, p. 93, pl. 1, figs. 7, 8.

This beautiful and interesting species was based originally on 4 individuals, some of
which had been discovered at @hnreh Buttes and others at Grizzly Buttes, Wyoming. Where
these types now are the writer does not know. It is possible that some of them are included
under No. 4062, of the U.S. National Museum. The specimen figured by Leidy was obtained
somewhere in the neighborhood of Fort Bridger. It is now in the collection of the Phila-
delphia Academy. All of his specimens appear to have come from the lower portion of level
B of the Bridger Eocene. The American Museum expedition of 1903 found fragmentary
specimens of the species at Grizzly Buttes and on Cottonwood Creek. The expedition of
1g05 secured at Henry’s Fork a nearly complete shell, which is here described and figured
(plate 43; text-figs. 352, 353): This comes from a higher level than the other known specimens.

Leidy’s reconstruction of this species aciabtted to it II pairs of peripherals. Dr. Baur
was the first to correct this error. The complete specimen just mentioned confirms Baur’s
statement.

The specimen found at Henry’s Fork belongs to the third division of level C. It has the
number 6132, of the American Museum. The specimen is slightly crusht. The neurals
(fig. 352) are all missing, as well as the left front part of the carapace. In form the carapace
is not so much excav ated i in front as is represented in Leidy’s figure. Other specimens of the
species show as little excavation.

The total length of the carapace (plate 43, fig. 1; text-fig. 352) along the median line is
125mm. The widthis 105 mm. The nuchal is slightly damaged, but its length has been close
to 20 mm. and the width the same. The free border is subacute; the thickness at the midline

280 FOSSIL TURTLES OF NORTH AMERICA.

is 5mm. There are eight pairs of costals. Those of the seventh pair join for a short distance
behind the seventh neural; those of the eighth pair join their full width. The costals are thin,
about 1 mm. in thickness. There is a single large, roof-shaped suprapygal, whose length is
18 mm. and whose width is 20 mm. The pygal has a height of 15 mm. and a width of 23 mm.
The anterior peripherals are about 12 mm. high, at right angles with the free border. Behind
the fifth this dimension increases until in the ninth it is 20 mm. The fourth and fifth are in
contact with the hyoplastron; the fifth, sixth and seventh, with the hypoplastron. Fig. 354
represents the anterior ends of the sixth, seventh and eighth. The free border of those in
front of the bridge is subacute; that of those behind the bridge, thin and acute. The lower
face of the anterior peripherals is smooth, while that of the posterior is sculptured. The
latter peripherals have a third, or inner face. This looks toward the interior of the shell and
is concave.

The carapace is exquisitely sculptured, the costals differently from the peripherals. The
costals are crost, parallel with the axis of the animal, by low undulating ridges, most distinct

celta

No. 6132 A. M. N. H

Fics. 252 AND 253.—Anostetra ornata. Carapace and plastron.
35 3D

52. Carapace.
353. Plastron. ent, entoplastron; epi, epiplastron; hyo, hyoplastron; hypo, hypoplastron; x:ph, xiphiplastron.

on the distal ends. The nuchal and the peripherals are ornamented by sharper ridges and
pustular elevations. In general, the ridges and the rows of pustules on the proximal. half of
each of these bones run parallel with the costal border. Those on the distal half radiate from
a focus placed some distance away from the free border. On the lower faces of the six hinder-
most peripherals of each side the radiations extend to the proximal borders.

The epidermal sulci are narrow and delicately imprest, but most of them may be traced.
On the nuchal and the four anterior peripherals the intermarginal sulci can not be seen,
owing to the sculpture. On the other peripherals the ascending sulci are easily followed,
but the costo-marginal sulci are not visible. From this and other specimens it becomes quite
certain that they ran along the upper borders of the peripherals, just below the costo-peripheral
sutures. On the pygal a median sulcus ascended about half the height of the bone, then
divided and sent a right and left into the costo-marginal sulci. The vertebral scutes appear to
have been remarkably modified. The first has a width of 18 mm. in front. We have a right
to look for a transverse sulcus crossing this region on the proximal ends of the first costals and
the first neural; but there is no trace of it. Instead of this, we find that the sulcus which

DERMATEMYDID&. 281

usually crosses on the proximal ends of the third costals and the third neural starts, as usual,
on the third costals, but is carried forward so as to cross on the first neural. This sulcus in
the specimen is very distinct; besides this, it has been observed on another specimen.
In the median line, on the front of the first vertebral, is seen a distinct sulcus which runs back-
ward to the hinder border of the nuchal bone. Whether or not it extended further can not be
determined. Probably it attained to the transverse sulcus on the first neural. Apparently
the only explanation of this condition is to suppose that the first and second normal vertebrals
have coalesct; that the sulcus between the second and the third has been carried forward to
the first neural and even to the nucho-vertebral sulcus; thus dividing the united first and
second vertebrals into right and left halves.

It seems probable that the third and the fourth vertebrals have coalesct; for no sulcus
crosses the proximal ends of the fifth costals and the fifth neural. The vertebral occupying
the area of the fifth in other turtles has a length of 37 mm. and a width of about 30 mm. As
an individual peculiarity, the fourth costal scute of the left side is divided by a sulcus which
descends on the seventh costal bone.

Fortunately the present specimen furnishes the epiplastra and the entoplastron, elements
not observed before (plate 43, fig. 15 text-hg. 353). The epiplastra are 37 mm. long; the width

is 13.5 mm. at the middle of the length. They narrow ante-

riorly. The entoplastron is 1g mm. long, pointed in front, 14

mm. wide behind. ‘These parts resemble considerably those

~ y es of Stauroty pus salviniu (Boulenger’s Chelonia, p- 31; fig. 10)

z but the entoplastron 1s more pointed in the fossil species and

Fic. 354.—Anosteira ornata. Ante- the epiplastra are not so prolonged at their hinder outer
rior ends of three peripherals. angles. 7 ; ; :

No. 6132 A. M.N. H. The whole length of the plastron 1s 86mm. The bridges

; have a minimum width of 15 mm. It joins the peripherals
x, sixth peripheral; y, seventh; 2, eighth. . :

: - by coarse sutures. The hyoplastron is only 4 mm. wide
on the bridge. Its greatest fore-and-aft breadth is 11 mm. The fore-and-aft extent of the
hypoplastra is 21 mm.; that of the xiphiplastra, 27 mm.

The bones of the plastron are markt by fine ridges and intervening grooves. On the
epiplastra these radiate from a point near the inner border, near the hinder end. On the
bridge the sculpture is transverse to the length of the body.

Neither on this specimen nor on any others has the writer been able to find evidences of
epidermal scutes on the plastron. Doubtless these were present, but they were so delicate that
their boundaries have left no impressions on the bones. Dr. Baur could not find the sulci on
the plastron of specimens at Yale.

Cope has mentioned the finding of specimens of this species on the “ Upper Green River.”
No. 1059 of the American Museum of Natural History bears his label to the effect that it was
found on Green River, at the mouth of the Sandy. The strata here belong to the lowest level,
A, of the Bridger. These have furnisht also Amyda equa. Cope’s specimen is somewhat
differently sculptured from the specimens from a higher level, the pustules predominating
over the ridges, on the peripherals. It is, however, probably not a distinct species.

The evidence at hand shows that this species ranges from the lowest level of the Bridger
beds to the top of that known as GCG

Anosteira radulina Cope.

Anostira radulina, Core, Palxont. Bull. No. 9, 1872, p. 555; Proc. Amer. Philos. Soc., xu, 1872, p. 5553
Ann. Report U. S. Geol. Surv. Montana, etc., 1872 (1873), p. 620; Vert. Tert. Form. West, 1884,
p. 128, plate xviii, figs. 18, 19.

Anostetra radulata, Baur, Ann. Mag. Nat. Hist. (6), 11, 1889, p. 273.

Anostira radiolata, LYDEKKER, Cat. Foss. Rept., 11, 1889, p. 144.

Anosteira radulina, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 447-

This species was described by Cope from two peripheral bones, one from in front of the
bridge, the other from behind it. These are now in the U. §. National Museum and have the
number 4096. They were found in the Bridger Eocene near Ham’s Fork, Wyoming, there-
fore in the lowest division, A, of the formation. The individual that furnisht these bones was

282 FOSSIL TURTLES OF NORTH AMERICA.

estimated by Cope to have been about twice the size of the specimens of 4. ornata that had
then been found. He concluded that it belonged to a distinct species for the reason that the
sculpture had not increast in coarseness corresponding to the increase in size of the animal.
This, however, is not a sufficient reason. Since the bones increase in size by additions to their
borders, the lines and pits of the sculpture once formed will not change in coarseness. A better
reason for regarding the bones as those of a species different from 4. ornata is to be found in
their form. The anterior peripheral, the first of the left side (Cope’s fig. 18), has the form of a
rhomboid, quite different from that of any anterior peripheral of 4. ornata. The lower side of
Cope’s figure is that of the free border of the bone. The thickness of the bone is 7 mm. The
hinder peripheral appears to be the ninth or tenth. It is 7 mm. thick and its free edge is obtuse.
In 4. ornata, on the contrary, it is acute.

The length of the anterior peripheral, along the free edge, is 25 mm.; its height is 28 mm.
Both these dasencionel in the hinder peripheral are 25 mm. Taihe sculpture of the anterior bone
is stated to consist of closely packt vermicular ridges which run out flat on the posterior and
upper borders. In the posterior the ornamentation consists of closely placed minute tubercles
over the whole surface, these being more or less confluent on the posterior and upper borders.

Mr. R. Lydekker has described and figured a species called Anosterra anglica, trom the
Lower Oligocene of Hordwell, England (Cat. Foss. Rept., 111, p. 143, figs. 34, 35). Dr. G.
Baur (Ann. Mag. Nat. Hist., 111, 1889, p. 273) has stated that this can not be distinguisht from
Cope’s 4. radulina. A glance at the figures of the two forms shows that they can not be
identical, the sculpture of the English species being far coarser. In 4. ornata the suture
between the hypoplastron and the xiphiplastron, in crossing from the free border to the mid-
line, runs first forward, then backward, then forward again. In the English species it runs
obliquely, but directly, inward and forward. It is not probable that two species of the same
genus would be so different.

Genus XENOCHELYS Hay.

Characters drawn from the type and only known ‘specimen. Neurals 6, the 4 anterior
having the narrow end directed forward. Only 7 pairs of costals; those of the sixth and
sev enth pairs meeting at the midline. Ten pairs of peripheral bones, and 11 pairs of marginal
scutes; the nuchal scute very small. Plastron joined to the carapace without Rae
Bridge narrow. Only 5 pairs of plastral scutes. “Two inframarginals on each bridge.

Type: NXenochelys formosa Hay.

This genus differs from Dermatemys in having no axillary or inguinal buttresses; 5,
instead of 6, pairs of plastral scutes; and in the es of the anterior neurals. In the reduced
number of peripheral bones and marginal and plastral scutes it resembles Staurotypus. In the
latter genus, too, 3 of the anterior neurals have the narrower end directed forward. The
width of the bridge of Xenochelys is intermediate between that of Dermatemys and that of
Stauroty pus. The two genera just mentioned, as well as Claudius, the nearest living relatives
of Xenochelys, are jababicants of Central America.

Xenochelys formosa Hay.
Text-figs. 355, 356.
Xenochelys formosa, Hay, Bull. Amer. Mus. Nat. Hist., xxu1, 1906, p. 29, figs. 2, 3.

Of this species there is at present known only the specimen which serves as the type. This
was discovered in the year 1904, at Quinn Draw, Washington County, South Dakota, by Mr.
Albert Thomson, of the American Museum of Natural History. The deposits in which it was
found belong to the lower division of the Titanotherium beds of the White River Oligocene.
The specimen consists almost wholly of the shell, and this is somewhat crusht. The plastron
is driven upward into the carapace, and a small portion of the left margin of the carapace is
wanting. The whole structure of the shell can nevertheless be determined.

The length of the carapace (fig. 355), measured ina straight line, is 200 mm.; the great-
est width 129 mm. The shell is therefore slightly narrower proportionally than that of
Dermatemys mawit. The height was moderate. A low rounded carina is found on the nuchal

DERMATEMYDID&. 283

and another on the hinder end of the carapace. There are slight traces of a lateral carina on
each side, along the outer borders of the vertebral scutes. In outline the carapace is slightly
excavated in front and notcht behind. The borders behind the inguinal notches were very
slightly flared upwards. The nuchal bone is well developt, hay-
| | ing a length and breadth each of 38 mm. There are no costiform

|

N 1. | Length. Width. - ; i

| Cae ie | oa processes. Of the 6 neurals the anterior 4 are hexagonal, with
|

| alt 2) e the narrower end directed forward, a somewhat unusual thing
: 5 | 5 | among both Cryptodire and Pleurodire turtles; nevertheless
A 18 6: occurring, according to Dr. Boulenger’s figures, in the case of some
4 6 | | of the neurals of Staurotypus, Kinosternon, Cyclemys, Geomyda,
; : ore al and Cyclemys. The sixth neural of our species is quadrate, the

_ seventh is triangular. The table gives the dimensions of the
neurals.
Behind the costals of the seventh pair there is a single suprapygal, 22 mm. long and 38 mm.

wide. This is succeeded by the notcht pygal, which has a length of 23 mm. and a width of
28 mm.

YS hum g| ,
\ ae
tf epi

t

( ent

355°

Fics. 355 AND 356.—Xenochelys formosa. Carapace and plastron of type. 4.

355. Carapace.
356. Plastron. an, anal scute; ent, entoplastron; epz, epiplastron; fem, femoral scute;
g, supposed gular scute; hum, supposed humeral scute.

As already stated, there are only 7 pairs of costal plates, of which the two hindermost
pairs reach the midline of the shell. The anterior pair is well developt, having an antero-
posterior width of 35 mm. The costals are about 3 mm. in thickness.

The peripheral bones are relatively large, and there are only 10 of them on each side. “The
second measures 26 mm. from the free border to the union with the costal plate; the third,
35 mm. The free borders of the anterior and posterior peripherals are acute. They attain
a maximum thickness of about g mm. The sulci bounding the epidermal scutes are moderately
imprest. There is a very small nuchal scute. The vertebral scutes have a width each of about

284 FOSSIL TURTLES OF NORTH AMERICA.

35mm. The first has a length of 45 mm. In form the vertebrals resemble those of Stauroty pus
salvinit. Along the hinder ends of each of the lateral borders of the three anterior vertebrals
there is a very deeply imprest groove. In the case of the first and second vertebrals these
grooves extend backward on that neural bone which is crost by the hinder border of each ver-
tebral respectively. The grooves along the third vertebral scute run backwards on the prox-
imal ends of the costals of the fifth pair.

The marginal scutes rise relatively little above the free borders of the shell, the second
having a fore-and-aft extent of only 13 mm.; the tenth, of only 15 mm. The costal scutes are
therefore relatively broad.

The plastron (fig. 356) has a total length of 163 mm. Where narrowest, the bridge has a
width of only 43 mm. The axillary and inguinal notches are very narrow. The plastron was
united with the carapace by a close suture, hac there are no buttresses rising from the plastron.
The anterior lobe has a length of 52 mm. and a width of 80 mm. at the base. It is broadly
rounded in front and enmienhat repand. The border is acute. The entoplastron is broadly
oval, 29 mm. long and 27 mm. wide. The hinder lobe has a length of 75 mm., and a basal
width of 62 mm., and is deeply notcht behind. The free border is acute, but the thickness
increases above, so that where the soft skin began the thickness was 6 mm. In the middle of
the upper surface of each xiphiplastron there is a rather deep, smooth impression, which was
probably for the lateral process of the pubis.

According to Riitimeyer (Denkschr. schweiz. naturf. Gesellsch., xxv, 1873, p. 152)
Dermatemys mawit possesses on each xiphiplastron a depression (Bandgrube) for the insertion
of the lateral process of the pubis.

The antero-posterior extent of the epiplastra is 35 mm.; that of the hyoplastra, 41 mm.;
that of the hypoplastra, 30 mm.; that of the xiphiplastra, 57 mm.

Besides the inframarginal scutes, there are only 5 pairs on the plastron of this species.
Of the inframarginals fhere are 2 on each bridge—a small anterior and a large posterior.

It is difhcult to interpret the anterior plastral scutes. Posteriorly we find anals and
femorals, in the usual positions. In front of the sulcus bounding the latter anteriorly there
is not a trace of a transverse sulcus until we reach the anterior end of the entoplastron. Occu-
pying the front of the anterior lobe are 2 pairs of scutes, which look like intergulars and gulars;
altho i it is not certain that the former are not consolidated into a single scute. It is evident that
there has occurred either a fusion of 2 pairs of scutes or an extirpation of one pair. If the most
anterior pair are intergulars, we must account for the absence of 2 pairs of scutes. In Der-
matemys the humero- pectoral sulcus has moved forward to near the anterior end of the hyo-
plastron. In Adocus pectoralts this sulcus has lain partly on the epiplastron. It appears
probable, therefore, that in NXenochelys the sulcus named has moved far forward; that is,
to the middle of the epiplastron. If this is the case, we have here gulars and humerals, instead
of intergulars and gulars. We have then to suppose either that the pectorals and the abdom-
inals have fused, mihiout a trace of the sulcus between them, or that the pectorals have
extended backward so as to suppress the abdominals. In Te studo osborniana the pectorals
have been nearly supprest by the forward expansion of the abdominals. The writer accepts
the view that in Xenochelys we have present the gulars, humerals, pectorals, femorals, and
anals. The pectorals have an antero-posterior extent of 68 mm. at the midline; the femorals
a similar extent of 32 mm.; the xiphiplastrals, of 37 mm.

It may be noted here that the specimen of ae emys maw figured by Dr. Boulenger
(Catalogue of Chelonians, P- 28) possesses only 7 pairs of costal plates. Amié Bienz (Rev.
suisse Zool. et Ann. Mus. d’Hist. Nat. Genéve, 11, p. 61) states that the species has 8 pairs of
costals. The same statement is made by Dr. Riitimeyer (loc. cit.).

Family EMYDID Gray.

Cryptodire turtles distinguisht by the following characters: Shell covered with epidermal
scutes. Peripherals articulated to costals by alone sutures and by gomphosis of rib-ends.
Neurals in full series. Bridges broad, usually sutured to peripherals; in rare cases ligament-
ously attacht. Plastron broad, composed of g bones, the mesoplastron never present. No
intergulars and no inframarginals, except axillary and inguinal. Procoracoid process forming

EMYDID&. 285

a right angle with the scapula. Coracoids not expanded at the distal ends. Humerus with the
radial and ulnar processes diverging. Digits usually elongated and the median ones furnisht
with three phalanges; only in T errapene are the median anterior digits reduced to 2 phalanges.
Feet fitted primarily for walking, but nearly always provided with a web between the toes.

Skull without temporal roof, except the zygomatic and postorbital arches, the former
occasionally wanting. Stapedial passage open. Neck completely retractile within the shell.

In the present work the writer, following by conviction the example of a large number of
students of herpetology, the names of ns es are mentioned by Louis Agassiz in his Contri-
butions to the Natural History of the United States (vol. 1, p. 356), has separated the true land-
tortoises, the Testudinidz, from the more or less aquatic forms that are to be known as the
Emydidz. For this course there appears to be found in the structures of the two groups
abundant justification. Furthermore, the two families have been clearly separated ever
since the time of the Lower Eocene.

Even as thus restricted the Emydidz contain more genera and species than any other family
of Testudines. According to Mr. G. A. Boulenger’s Catalogue of Chelonians, the Emy-
dide, excluding the land-tortoises, embrace seventeen genera and sixty-four species; and
these numbers are to be increast, rather than diminisht. Probably no other family displays
a greater range of habits. Some of the species are almost w holly aquatic, as those of the
genera Chrysemys and Graptemys; others are semiaquatic, as the members of Emys and
Clemmys; while still others, as Terrapene, are nearly as terrestrial as the Testudinidae them-
selves. Of the aquatic forms a few, as the diamond-back terrapins (Malaclemys) affect the
salt waters of the sea-coasts; while the greater number inhabit fresh-water lakes and streams.
Most of the species are carnivorous in their diet, but a few, as the box-tortoises (J errapene)
subsist on vegetation.

As regards their present-day distribution, the Emydide are found occupying portions of
all the continents and the larger islands of the warmer portions of the globe, except Australia
and the neighboring islands (fg. 13, page 33). It is evident that by some ancient connection
of Australia with other lands, probably with Asia, the Pleurodires were enabled to occupy
that southern continent, as well as New Guinea; but this connection was interrupted before
the Emydidz and the Testudinid had passed over that bridge.

Altho the Emydidz have secured a foothold in the African continent, their distribution is
limited to the northwestern and northern coasts. Only 2 species are known from Africa—
Emys orbicularts and Clemmys leprosa. The first is widely spread over Europe and south-
western Asia and is found in Algeria. It is within the range of possibility that it has
been introduced into Algeria through human agency. Clemmys leprosa is found along the
southern Mediterranean coast, from Tunis to the Atlantic, thence southward to Senegal.
It has evidently entered Africa at a late geological period and has prest southward along
the Atlantic coast until it has reacht the border of the Ethiopian region. To turtles, as to
other groups of animals, the Sahara desert has for a long period stood as a barrier to their
southern migration.

Itisa ae difficult, perhaps impossible, of explanation at present, that while the Emydide
are absent from the Ethiopian region, the Testudinide, a strictly terrestrial family, and the
Trionychide, wholly aquatic in their habits, abound in that great region. It might seem that
where the Triony chidz could go the Emydidz could easily follow: However A the Trionychidze
are a much older family add might have entered Africa before the Emydide had become
widely distributed and at a time w hen the connections of the continents were greatly different
from those now existing. It seems establisht that some of the species of Triony chidz have been
able to adapt ee es to life in sea-water, and this ability may have allowed them to work
their way along sea-coasts from one fresh-water region to another.

The Testudinidz, on the other hand, are less dependent on abundance of water for exist-
ence than are the Emydidz and might have made their way across the Sahara or the deserts of
western Asia into the Ethiopian region. To the writer it appears more probable that the land-
tortoises reacht Africa from India by a land connection, of which the Seychelles, Mauritius, the
Aldabras, and Madagascar are remnants which within recent or Pleistocene times have been

inhabited by gigantic Testudinide.

286 FOSSIL TURTLES OF NORTH AMERICA.

In the Pliocene deposits of the Siwalik Hills, India, there have been found five genera of
Emydide. Why these did not effect an entrance into Africa in company with the various
ruminants, hog-like ungulates, antelopes, monkeys and apes, is not now to be explained.

We have no certain evidence of the existence of Emydide before the beginning of the
Tertiary. Indeed, not until the Wasatch epoch in America and the epoch of the London Clay
in Europe, do we find undoubted Emydida. When they do appear they are in many respects
as advanct as are some of the living forms. We can not, therefore, doubt that they had a much
earlier beginning and we may await with confidence the discovery of their predecessors in
Cretaceous deposits. The genus Gyremys, found in the Judith River beds, is provisionally
assigned to the family.

As regards the evolution of the family not much can be said. In the Eocene forms the shell
resembles greatly that of the modern genera. It is composed of the same pieces and these are
arranged in the same way. Most of the forms from the Wasatch and the Bridger possess
strongly developt axillary and inguinal buttresses, such as we find to-day in a number of
Asiatic genera. There appear to have been other genera which did not possess such buttresses,
and from such as these have probably descended most modern forms.

We are, unfortunately, without sufficient materials to enable us to determine the structure
of the rest of the skeleton. The limbs of the Bridger turtles, so far as represented, were not
different from those of living aquatic emyds. Only a single Bridger emyd skull is known, and
this was not associated with a shell. This skull resembles considerably that of our genus
Clemmys, the triturating surfaces of the jaws being narrow and with only a rudimentary
longitudinal ridge. In many modern genera of this family the jaws have become broadened
and the maxillary, and sometimes the mandibular, triturating surfaces have developt one or
more longitudinal ridges. The horny plates which cover these surfaces are often rough with
processes that resemble and function as teeth. The living genus Terrapene, as befits its
terrestrial mode of life, has simulated many of the features of Testudo. The shell has become
inflated, the digits shortened, and the diet a vegetable one. Besides these modifications, the
plastron has become movable on the carapace and a hinge has developt between the hyo-
plastron and the hypoplastron. Even in the Lower Oligocene the genus Ptychogaster had
developt somewhat similar structures.

Mr. G. A. Boulenger (Catalogue of Chelonians, p. 49) has exprest the opinion that the
genus Enmrys is, in many respects, the least specialized of this family and might be placed at the
base of the family, with two series of genera culminating, on the one hand, in the Batagurs
and, on the other, in the land-tortoises. The present writer can not agree in this opinion. He
holds first of all that the land-tortoises form a distinct family which diverged from the Emydidze
even as early as the Cretaceous. Again, Emys displays a rather high grade of differentiation
in the ridged triturating surfaces of the jaws, and especially in the secondary loosening of the
articulation between the carapace and the plastron, and in the formation of a hinge between
the hyoplastron and the hypoplastron. Such a form as Clemmys appears to represent better
the simple emyd structure. In this the jaws are narrow and smooth, the plastron is immovably
articulated with the carapace, there is no hinge in the plastron, and the plastral buttresses are
feeble. From such a form there might be produced the Batagurs, with their broad corrugated
jaws and their powerful buttresses, and Emys and Terrapene, with their narrow jaws, their
feeble buttresses, and their hinged plastra.

From what forms the Emydide sprang we know not as yet. We shall probably find that
the limbs of the earliest Cryptodira were not greatly different from those of our aquatic Emy-
dida. The shells of the family ancestral to the Emydidz need not have differed greatly from
that of Chrysemys, for example; for even the early Amphichelydia have the carapace and the
plastron closely articulated. The buttresses of the ancestors of the early emyds were probably
little developt. The neck was probably short and the head not wholly retractile within the
shell. The skull was probably considerably like that of Chelydra, but with a more completely
developt temporal roof. Perhaps the skull of Platysternum resembles it more. Such a family
would not be greatly removed from the Thalassemydide.

In a paper publisht in the Bulletin of the American Museum of Natural History, vol.
XX1, p. 167, the author indicated his belief that the Emydide had sprung from the Chelydridz.
He is now inclined to the opinion that they had their origin from some of the more primitive

EMYDID&. 287

Dermatemydidz. The latter family was abundantly represented during the Upper Cretaceous
and only slight modifications would be required to transform them into Emydida.

In Europe the earliest Emydidz appear to be those found in the London Clay, which
is of about the same age as the American Wasatch beds. Two species are found there; and
these have been referred by Mr. Lydekker to Chr ysemys, a living North American genus.
Doubtless when the skulls shall have been found these species will have to be relegated to some
other genus. In the Oligocene of Hordwell, England, two species occur which Lydekker
refers to Ocadra, a genus existing to-day in China. Te resembles closely the genus Echmatemys
but the latter probably did not have a longitudinal ridge on the maxillary triturating cipiices
and the plastron is less contracted than it is in Ocadza. No other species of Emydide have
been discovered in England, so far as known to the writer.

On the continent of Europe, as recorded by Maack (Palzontographica, xvill, 1869, p. 193)
and by Zittel (Handbuch der Palaontologie, 11, p. 537), many species of Emydidz have been
described and the greater part of them referred to Emys, Crstudo, and Ptychogaster. Only
those called Cistudo are really members of Emys as now understood. This genus ‘thus appears
to extend back to the Oligocene. Those placed by Maack and Zittel in die genus Emys are
probably more closely related to Clemmys or Oc adia. Ptychogaster is an Oligocene and Lower
Miocene genus, the carapace of which resembles in many respects that of Tasule, while the
plastron is hinged like that of T errapene.

The following table shows the distribution of the North American fossil species of the

Emydide:

Terrapene carolina, T. eurypygia, T. marnochi, Trachemys bisornata, T. petrolei, T. trulla,

| Pleistocene. Equus. Chrysemys timida, Clemmys insculpta, Clemmys? percrassa, C. insculpta, ?Pseudemys
celata.
| Blanco, Terrapene putnami, ? Trachemys euglypha, T. sculpta, T. jarmani, ?Clemmys hesperia, Dei-
‘ Rattlesnake, rochelys floridana, Pseudemys extincta.
| Pliocene. q / ,

an

Peace Creek.

| Miocene. Loup Fork. Trachemys hill, Clemmys saxea.

r - John Day 7 x : -
| Oligocene. White River Graptemys inornata.

| - - Uinta Echmatemys callopyge, E. uintensis.

| Echmatemys septaria, E. ‘shaughnessiana, E. ocyrrhoe, E. stevensoniana, E. haydeni, E.
Bridger. arethusa, E.naomi, E. cyane, E. egle, E. wyomingensis, E.? latilabiata, E. pusilla, Paleo-
theca polycypha, Pp. terrestris, Clemmys morrisia, Hybemys arenaria.

| Eocene. |——__|__ — E =
| Wind River.
| W asatch. Echmatemys lativertebralis, E. cibollensis, E. testudinea, E. megaulax, E. euthneta.
| pene
a Laramie.
| Upp Fox Hills.
Cretaceous.
|

Judith River. | >Gyremys spectabilis.

Key To GENERA OF EMyYDID&.

A. Insufficiently known genera.
a‘. Carapace broad as long; the outer surface sculptured somewhat as in Tronychide. . Gyremys
a’. Small Bridger species, with dorsal keel and thick bones .................... .... Paleotheca
a®. A hemispherical boss situated on each interperipheral suture . Hybemys
AA. Better known genera.
Axillary and inguinal buttresses strongly developt; the latter projecting well into
the cavity of the shell and rising high above the costo-peripheral suture Echmatemys
Buttresses rising but little above the costo-peripheral sutures.
Plastron without either lateral or transverse hinge.
c. Crushing-surface of upper jaw with feeble or no longitudinal ridge.
d', Humero-pectoral sulcus crossing the entoplastron .. Clemmys
d°, Humero-pectoral sulcus crossing behind the entoplastron,

288 FOSSIL TURTLES OF NORTH AMERICA.

1. Shell smooth; no dorsal keel; crushing-surface of upper jaw
with a feeble ridge; rib-heads well developt................ Chrysemys
2. Surface of shell sculptured; rib-heads thread-like......... .... Detrochelys
Shell smooth or wrinkled; crushing-surface of upper and lower
jaws broad and flat; palatine bones joining vomer in front of
ChOANZY cade Sars Boehner ne ee, ae ee ae Graptemy
. Crushing-surface of upper jaw witli, a strong longitudinal ridge.
4. “At least a trace of a dorsal keel; carapace often sculptured;
crushing-surface of upper Be with a denticulated ridge highest
in jane ae : ee ane Trachemys
5. Crushing-surface of upper jaw very broad, with a denticulated
longitudinal ridge; lower surface of lower j jaw flat <o.n2sn0020 Pseudemys
b°. Plastron completely filling the opening of the carapace; furnisht with both
lateral and transverse hinges. . yee ep eT en . Terrapene

io)

Genus GYREMYS nov.

Shell deprest; as broad as long, or broader; with plastron and carapace sculptured as in
the Trionychide; both furnisht with epidermal scutes, the vertebrals very broad. Carapace
with a complete set of peripherals. Neurals mostly hexagonal, with the broader end forward.
Plastron without fontanels, and joined to the carapace by means of anterior and posterior
buttresses. Apparently no mesoplastra present.

Type: Gyremys spectabilts.

This genus differs from G/yptops, as represented by G. plrcatulus, in the form of the cara-
pace, the width being greater than the length, and in the character of the ornamentation of the
shell. The lack of mesoplastra, if confirmed, will be decisive in showing its non-relationship
to Glyptops. Inthe latter genus, as well as in Pleurosternon, the suture between the hypoplastra
and the xiphiplastra runs across the plastron in a straight line or is even deflected backward at
the midline, apparently a primitive character; while in Gyremys the suture is deflected forward
at the midline.

Provisionally this genus is arranged with the Emydidz. No intergulars or inframarginals
have been observed, bi they may nevertheless have been present. It is possible that the genus
belongs among the Der matemydide.

Gyremys spectabilis sp. nov.
Plate 44, figs. 1, 2; text-figs. 357, 358.

Under this name there is here described a remarkable turtle which was collected in 1876
for Professor Cope, by Messrs. Sternberg and Isaac, in the Judith River deposits of Montana.
Apparently the remains were never examined by Professor Cope, and the many fragments
of which it was composed were put together after it came to the American Museum of Natural
History. The specimen bears the Snel LIZ.

The bones of this turtle were originally thin; and as a result of the conditions attending
fossilization they have been much faetited, Consequently, it is difficult to determine fhe
positions of some of the sutures and scutes, especially those of the carapace.

As regards the parts remaining, the plastron is complete; the carapace lacks the nuchal
bone, the right first peripheral, the left first costal, and several of the left peripherals.

The shell was a remarkably broad and flat one. The total length of the carapace (plate 44,
fig. 1; text-fig. 357) was about 440 mm.; the width, 500 mm. Hence, the shell was broader
than long. As restored, the height of the carapace above the bottom of the plastron is only
7omm. It was no doubt more elevated during life, but probably not much.

The ornamentation of the shell consists, where distinctly displayed, of low, short, irregular
ridges, separated by grooves of the same width, and occasionally anastomosing. ‘There are
about five ridges in 10 mm. ‘The central portions of the carapace, however, are nearly smooth.
In most parts of the shell the sculpture is so effaced that its character can hardly be determined,
beyond the fact that it resembles that of the Trionychide.

However, the relationships of this turtle are not with the Trionychidz, but with the
Cryptodira; for the plastron is completely closed and the costals are surrounded by a complete

EMYDIDA. 289

set of peripherals. No fontanels occur anywhere, except apparently a small one on each side
of the suprapygal.

On account of missing parts, the outline of the front of the carapace can not be determined.
The shell was broadest across the inguinal region. The hinder border shows a broad shallow
excavation. An attempt has been made to map out the areas occupied by the neurals, costals,
and peripherals. The position of most of these has been determined pretty satisfactorily. The
extent of the peripherals is somewhat conjectural, as shown by the interrupted lines in the
drawing. Most of the sutures had to be traced on the inside of the carapace. As there seen,
the costals approach to within 45 mm. of the free border of the carapace.

So far as can be determined, the inguinal buttresses rest against the fifth and sixth costals.
The buttresses did not rise to a great height. The ribs were quite prominent on the under side
of the costal plates. The rib-heads were strongly developt. The tenth rib formed an abutment
for the upper end of the ilium.

The first neural is missing. The second has the front border wanting, but it was about
48 mm. long and 27 mm. wide. The third is hexagonal, 46 mm. long and 48 mm. wide. The

357: y ; a 7 358.

n
T
|
|
abe

ie
Fics. 357 AND 358.—Gyremys spectabilis. Carapace and plastron of type. §-
357- Portion of carapace. 358. Plastron.

limits of the fourth are uncertain; it may have been wider than represented. The plotting of
the areas behind the eighth neurals and costals is to some extent conjectural. “The thickness
of the costals is from 7 mm. to 10 mm.; but the ribs added something to this in the middle of
the breadth.

The scutal areas are even more difhcult to determine than are the bones. Enough, how-
ever, is determinable to prove that the vertebral scutes were very broad, the second and the
third having had a breadth of about 170 mm. The boundaries of the fourth are conjectural,
but probably not greatly different from the drawing. Toward the borders of the carapace no
sulci are to be detected and no attempt has been made to represent them.

The plastron (plate 44, fig. 2; text-fig. 358) is well preserved, altho the external layer of
bone on its upper surface is eroded away. The lower surface is in better condition, but the
bone is much fractured. The total length of the plastron is 425 mm. The anterior lobe 1s
broad and rounded in front; the hinder is somewhat wedge-shaped, with the extremity trun-

We,

290 FOSSIL TURTLES OF NORTH AMERICA.

cated. The anterior lobe is 240 mm. wide at the base and 118 mm. long. There is no
specialized epiplastral lip. The bones are about 10 mm. thick, and the free borders are sub-
acute. The posterior lobe is 144 mm. long and 205 mm. wide at the base. The lateral borders
are somewhat convex in outline, and they converge toward the rear. The latter is truncated
and about 50 mm. wide. The median and the hinder portions of the lobe are thin, from 4 mm.
to8 mm. From the acute borders of the hypoplastron the bone thickens inward a distance of
30 mm., then grows thinner.

The axillary and the inguinal buttresses extend inward little further than the free borders
of their respective lobes. The entoplastron is diamond-shaped, with the posterior angle
rounded. Itis 75 mm. wide and 65 mm. long. The hyoplastra occupy 112 mm. of the midline;
the hypoplastra about 110 mm.; the xiphiplastra, 100 mm. A very careful examination fails
to discover the presence of mesoplastra.

The gular scutes appear extraordinarily large and the shallow grooves which are taken to
represent them may be deceptive. No evidence: are found of ihe presence of intergulars,
but they may have existed. The gulars overlap the front of the entoplastron. The humero-
pectoral sulcus does not cross any part of the entoplastron. The humerals extend along the
midline 38 mm.; the pectorals, 75 mm.; the abdominals, 62 mm.; the femorals, 110 mm.;
the anals, 40 mm. It is impossible to make any statement regarding the scutes of the bridges.

Genus CLEMMYS Ritgen.

Shell only moderately elevated. Neural plates hexagonal, with the broader ends forward.
Usually, but not always, at least some traces of a dorsal keel. Axillary and inguinal buttresses
feeble, extending upward little, if any, above the lower borders of the costals; the inguinal
articulating with the fifth costal. Humero-pectoral sulcus crossing the entoplastron. Plastron
notcht behind. ‘Triturating surfaces of the jaws narrow, not furnisht with ridges. Choanz
between the eyes.

Type: Clemmys punctata Schoepff=C. guttata Schneider.

At the present day there are about 6 living species of this genus. These inhabit Europe,
northwest Africa, southwestern Asia, China, Japan, and North. America. Four of the known
species occupy portions of North America, 3 of them being limited to the region east of the
Mississippi River, 1 to the Pacific coast. In the present work five fossil species, all based
unfortunately on fragmentary materials, are referred to this genus. One of these, C. saxea,
belongs to beds believed to be Pliocene, a second species, C. hesperia, to the Mascall beds of
the Upper Miocene; a third species, C. morrisre, to the Bridger Eocene; a fourth supposed
species is C. percrassa Cope from the Pleistocene cave near Port Kennedy, Pennsylvania.
It seems probable that North America is the original home of the genus and that the Old
World has received its stock from the New World.

The descriptions of the species of this genus are introduced at this stage because it appears
to the writer that the structure is rather primitive and that from this genus may have been
developt almost any of the other forms of the Emydidz.

1. Eocene species (Bridger beds):

Resembling C. muhlenbergt hee eee 2 oa e GS cates AS ee ee morrisie
2. Upper Miocene species (Mascall beds):
Resembling C. marmorata............... : ace cAisis HoAtal nearness GHESPERa

. Pliocene species (Rattlesnake beds):

Pygal bone transversely convex........ sh wide. tiehag edo ee eee:
4. Pleistocene species:
Finder lobelpreatly ‘thickened! so. 2 s).2c 20+ o> aac eeeeeie slee aie .... percrassa
Hinder lobe moderately thickened. ........ PS RAE AIR Ore insculpta

eo

eGaveien pe ees Saxea

Clemmys morrisie sp. nov.

Plate 45, figs. 1-3; text-figs. 359, 360

Of this interesting species there were collected by the American Museum expedition of
1903, in the western portion of Grizzly Buttes, portions of 4 individuals. These now have the

EMYDID&. 291

catalog numbers 6019, 6020, 6024, and 6029. The level from which these were obtained is
that known as horizon B. No. 6029 is taken as the type of the species.

The portions of the skeleton presented by the specimens bear such close resemblance to
the corresponding parts of Clemmys muhlenbergi that the species is referred provisionally to
that genus.

The type furnishes most of the anterior lobe of the plastron, a portion of the hinder lobe,
a part of the nuchal, parts of the right first, second, and third peripherals, and the whole free
border of the left second peripheral. The nuchal (fig. 359) was about 19 mm. wide along the
free border and about 32 mm. wide at the maximum. The front border is acute-edged, but
the bone grows rapidly thicker until, at a distance of about 12 mm. behind the free border and
near its articulation with the peripheral, it is g mm. thick. On the under side of the bone, at
a distance of 15 mm. from the free border, behind the portion covered with horn, the thickness
becomes suddenly reduced to 5 mm. The free edge of the first peripheral is acute next the
nuchal. The second peripheral has a length of 16.5 mm. along the free border. This is very
obtuse, especially where it joins the third peripheral. The greatest thickness of this peripheral
is g mm. On the under side, at a distance of 12 mm. from the free edge, the thickness is
abruptly reduced to 3 mm. The nuchal scute is g
mm. wide posteriorly and about 6 mm. long. The first
marginal scute had a fore-and-aft extent, or height, of
12 mm. at the distal end. The second marginal at its
distal end on the second peripheral was narrowed
down to 7 mm. in height. The height of the third
was about 10 mm. at the distal end. On the lower
side of the nuchal and of the peripherals the horny
scutes extended backward as far as the thickened part
of the bones continued.

Fics. 359 AND 360.—Clemmys morrtsta. Portions of
carapace and plastron of type. 3. Known por-
tions inclosed within solid lines.

359. Restoration of front of carapace.
360. Restoration of plastron.

The anterior lobe of the plastron (plate 45, fig. 1; text-fig. 360) had a width of about 65
mm. Seen from below (fig. 360), the lobe is convex in every direction. The lip projects
extremely little. Its width, measured between the gulo-humeral sulci, is 29 mm. The ento-
plastron has a width of 25 mm. Its length can not be exactly determined, but it probably
little exceeded 25 mm. In form, so far as preserved, it resembles that of C. muhlenbergi.
The gular scutes overlap only slightly the front of the entoplastron. Their length on the midline
is 1g mm. The humerals measure on the midline 14 mm. The pectorals overlapt the hinder
end of the entoplastron. The whole free border of the anterior lobe is acute, including the lip.

Plate 45, fig. 1, represents the anterior lobe as seen from above. From the free border of
the lip the epiplastrals are thickened backward a distance of 20 mm., attaining a thickness of
13mm. This is then suddenly reduced to 7 mm., forming an ov erhanging and somewhat
excavated ledge. The sides of this thickened surface are sw ollen and ornamented with ridges
and grooves, the marks of the growth of the gular scutes. Similar markings are seen on the
epiplastrals of C. muhlenbergi. The portions of the gular scutes on this superior surface are as
wide behind as at the free border. The thickness of the epiplastrals, where they articulate
with the hyoplastrals, is reduced to 7 mm.

292 FOSSIL TURTLES OF NORTH AMERICA.

Plate 45, fig. 2, represents the inguinal region of the hypoplastron and the adjacent part of
the xiphiplastron, seen from above. The free border is acute. The beveled, horn-covered
surface, on the upper side, is 18 mm. wide and attains a thickness of g mm. At its inner border
the thickness falls off suddenly to 6 mm. The lines of growth of the femoral scutes are dis-
played on this surface. Evidently there have been no strongly developt inguinal buttresses
extending inward on the plastron such as we find in Echmatemys.

Fig. 3 of plate 45 presents a view of the upper side of the left xiphiplastron.

Fig. 360 shows the same bones viewed from below. Near the anterior border of the
fragment of the hypoplastron is seen the abdomino-femoral sulcus. The femoro-anal sulcus
crost the free border at the hinder end of the fragment.

No. 6024 furnishes the front of the nuchal as far backward as the bone was thickened,
and the hinder portion of the left xiphiplastron. On the lower surface of the nuchal, at the
midline, the thickened portion extends backward only about 12 mm.; but toward each side
this increases to 19 mm. The lines of growth of the first marginal scutes are very conspicuous
on this surface. On the upper side of the bone the nuchal scute is observed to be g mm. long,
3 mm. wide in front, 10 mm. wide behind, and to be more deeply notcht posteriorly than in
the type. The piece of xiphiplastron is very flat on the under side and has the free border
acute. The beveled surface on the upper side is 11 mm. wide and ornamented with the growth
lines of the femoral scute. There was a notch in the hinder end of the lobe.

No. 6019 is the epiplastron of a considerably smaller individual than the type. It differs
especially in having the upper surface of the lip less swollen, the greatest thickness being only
about 6 mm. This surface shows the lines of growth of the gulars.

No. 6020 furnishes a portion of the epiplastral lip and a fragment of the hyoplastron.
The individual seems to have been slightly larger than the type. The upper surface of the lip
is strongly folded. The fragment of hyoplastron belongs behind the entoplastron and is rep-
resented in fig. 360. Its thickness is only about 4mm. The pectoro-abdominal sulcus crost
it about 8 mm. in front of the hyohypoplastral suture.

C. morrisie resembles in some respects Echmatemys pusilla, especially in the epiplastral
lip. For differences see the last-named species.

This species is named in honor of Mrs. Lindsey Morris Sterling, in recognition of the
skill, accuracy, and artistic taste shown by her in the preparation of the great majority of line
drawings in this work.

Clemmys hesperia Hay.
Plate 45, figs. 4-7; text-figs. 361-365.

Clemmys hesperta, Hay, Bull. Geol. Dept. Univ. Calif., 111, 1903, p. 238, figs. 1-5.

As the type of this species, is taken the bone bearing number 2219 of the Paleontological
Department of the University of California. This is the left hyoplastron, having the outer pos-
terior portion, which enters into the bridge, missing. Plate 45, fig. 4, and text-fig. 361, represent
it of the natural size and viewed from below. The sutural edges are present which met the
hyoplastron of the opposite side, the postero-lateral border of the entoplastron, the hinder
extremity of the epiplastron, and the front of the hypoplastron. As will be observed, the
humero-pectoral sulcus, represented by a dotted band, crosses the entoplastron, while the
pectoro-abdominal sulcus is well back on the hyoplastron. The structure of these parts is
identical with that of the genus Clemmys, represented to-day on the Pacific Coast by Clemmys
marmorata. The free border of the bone between the humeral buttress and the epihyoplastral
suture is acute. The bone thickens until it reaches a thickness of 7 mm. where the suture just
named meets the entoplastron. At the inner posterior angle the bone is only 3 mm. thick.

In lot No. 2179, believed to be from the Rattlesnake beds of the Pliocene but possibly
from the Mascall beds of the upper Miocene, there is a portion of a left hyoplastron which
lacks the free border, but which as far as it is represented is identical with the specimen
above described. The writer regards it, therefore, as belonging to the same species and to the
same formation. In this lot are included also a portion of the right epiplastron (plate 45, fig.
5; text-fig. 362), the first right peripheral bone (plate 45, fig. 6; text-fg. 363), a mght periph-
eral, apparently the eighth or ninth, and some other fragments. The epiplastron has the

EMYDID. 293

border which joined its fellow of the other side missing, so that it is impossible to determine
accurately the width of the anterior lip of the plastron. However, this bone has been used
in making the restoration of the front of the plastron, as seen in fig. 361. Plate 45, fig. 5, and
text-fig. 362 show this bone as seen from below. It resembles closely the same bone in C.
guttata, except that its upper side was not so deeply excavated as in the latter species. Accord-
ing to the restoration the lip had a breadth of about 34 mm.

The free borders of the epiplastron are subacute. Seen from the side, this border runs
forward to the gulo-humeral sulcus and then turns rather abruptly downward, forward and
inward. From the acute edge the bone thickens rapidly, until a thickness of 7 mm. 1s attained.
The gulo-humeral sulcus probably continued backward on the entoplastron.

A piece of the thickened border of the xiphiplastron of this specimen is present. It extends
from the junction with the hyoplastron to just behind the femoro-anal sulcus. Most of the
free edge is broken away, but enough remains to show that it was acute. It thickens gradually
until, at the inner border of the surface above, which was covered with horny skin, the thick-
ness is} mm. The femoro-anal sulcus comes to the free edge 19 mm. behind the anterior end
of the bone.

Plate 45, fig. 6, and text-fig. 363 present a view of the first right peripheral, both from above
and from the right-hand edge, which joined the second peripheral. The left-hand border

}
| \
, og \
% \ |
ae \ y
}
; i
rd 362. 304. 364a.
yr !
we 1
§ 1 7 (a? Sn oS
} \ |
} . t
i ‘ |
3 7 :
3 / % \ Aaa
iy f 14 r - =)
ke l
» He Van eens - oe see =e
301. 3034. 33- 365.
Fics. 361-365.—Clemmys hesperta. Portions of shell. 1.

361. Left hyoplastron of type. No. 2219 Univ. California. The epiplastron is restored.
362. Portion of right epiplastron. 1. No. 2179 Univ. California.

363. First right peripheral, with section (a). <1. No. 2179 Univ. California.

364. Probable ninth peripheral, with a section (a). No. 2179 Univ. California.
365. Section of free border of hypoplastron. No. 5527 Uniy. California.

joined the nuchal. The first peripheral resembles closely that of C. guttata. It will be observed
that the outer anterior angle of the first vertebral scute extends outward on the bone here
described and comes into contact with the second marginal scute. We have the same arrange-
ment here that we find in C. leprosa, as shown by fig. 30, page 102, of Boulenger’s Catalogue
of Chelonians. This indicates that the first vertebral scute was broader than it is in C. guttata.
The peripheral mentioned above, probably the ninth of the right side, resembles somewhat
that represented by plate 45, fig. 7, and text-hg. 364; but it is shorter antero-posteriorly and
higher, the fore-and-aft dimension being 15 mm., the height 19 mm. The longitudinal sulcus
runs closer to the upper border than in fig. 364. The figure just referred to presents a view of
the left ninth peripheral of an individual somewhat larger than the one just described. It
is part of a lot numbered 552, from either the Mascall or the Rattlesnake beds. Fig. 364
shows the upper surface and the anterior end of the bone. Accompanying this bone there ts
the hinder outer angle of the hypoplastron, extending from the suture with the xiphiplastron
to the inguinal buttress. A view of a section of the bone near the xiphiplastral suture 1s

204 FOSSIL TURTLES OF NORTH AMERICA.

shown in fig. 365. It is possible that this lot was derived from the Mascall beds and does not
belong to this species.

Bion a comparison of the bones above described with the corresponding parts of C.
guttata it appears that the carapace of C. hesperia attained a length of 5 or 6 inches. Unfortu-
nately, the writer has not been able to compare the fossil species with C. marmorata of the
Pacific Coast.

From the Rattlesnake beds of the Pliocene, Rattlesnake Creek, Oregon.

Clemmys saxea Hay.

Plate 45, figs. 8-10; text-fig. 366.
Clemmys saxea, Hay, Bull. Geol. Dept. Univ. Calif., m1, 1903, p. 241, fig. 6.

This species is founded on rather meager materials, being represented by only 2 bones, the
pygal and a posterior peripheral. These bear the number 2192 of the museum of the
University of California. They were collected from the Mascall beds of the upper Miocene
on Beaver Creek, near Crooked River, Oregon.

The pygal originally taken as type of the species is represented by plate 45, figures
8, 9 and text-fg. 306. These figures present views of the bone seen from above, from below,
and also as seen from the eueural edge; and therefore both the size and the thickness of the

een c bone are indicated. It has an antero-posterior length of 18
2 ee ] mm. and a width of 22 mm. at the anterior end and of about
\ \ 10 mm. at the posterior end. The greatest thickness is 6
mm. On the superior surface the bone is convex; on the
inferior surface it is concave. The sulci bounding the der-
mal shields are deeply imprest. The one between the last
vertebral scute and the supracaudal scute lies well down on
the bone, as in C. guttata. In C. leprosa, according to Dr.
Boulenger’s figure, this sulcus lies on the penultimate pygal
bone. This bone is of rather peculiar form and will doubt-
less be easily recognized when additional materials have been discovered.

The peripheral accompanying this pygal (plate 45, fig. 10), the tenth of the left side,
resembles the one represented by fig. 7, but is smaller, and the horizontal sulcus has evidently
run very close to the upper border, as it does in the corresponding bone of C. leprosa. Near
the hinder end of the upper edge of the bone is a deep pit for the end of a rib.

It is possible that the bones described under Clemmys hes peria, belonging to Nos. 2179 and
552, belong to this species, there being some doubt regarding the level in which they occurred.

Be a
a b
Fic. 366.—Pygal of Clemmys
saxea. Type. XI.

a, outer view; J, section.

Clemmys? percrassa Cope.

Clemmys percrassa, CopE, Jour. Acad. Nat. Sci. Phila. (2), x1, 1899, p. 194, plate xviii, figs. 1-1g.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1903, p. 449.

The described specimens of the present species are in the collection of the Philadelphia
Academy of Science, except that bone which is represented by Cope’s fig. Ie, and except
apparently also those bones called by him “No. 3.” All these bones were found in the Pleisto-
cene deposits of Port Kennedy Cave, in Montgomery County, Pennsylvania. The described
remains included parts of two, perhaps of three, individuals.

That bone which is called by Cope his “‘No. 1” and which 'furnisht his fig. 15 must be
regarded as the type of the species. This figure, like most of those of that paper, is poor and
shows little more than the shape of the face figured. This bone includes a considerable portion
of the right xiphiplastron. The figure presents the lower face of the bone. The hypoxiphiplastral
suture forms the upper right border of the figure, while the free border of the bone is on the
left. There is present a portion of the median longitudinal border. This makes an acute angle
with the hypoxiphiplastral suture, but the size of the angle can hardly be determined. The
thickness of the bone here is 9g mm. or 10 mm. From this border the bone thickens slowly
along the hypoxiphiplastral border a distance of 30 mm; then it rapidly rises to the summit of
a wall along the free border. The outer face of this wall is nearly perpendicular and

EMYDID&. 295

the summit is 18 mm. above the lower face of the bone. Backward, the wall descends, so that
at the femoro-anal sulcus it is only 10 mm. high and its outer face is not so steep. The length of
the hypoxiphiplastral suture is 51 mm. The femoro-anal sulcus reaches the free border of the
bone at a distance of 30 mm. behind the anterior border.

The originals of Cope’s figs. Ic, 17, and 1g are portions of the central region of the plastron.
They are about 5 mm. or 6 mm. thick.

Cope’s fig. 1 represents what to the present writer appears to be the right eighth peripheral.
It resembles: greatly the corresponding bone of Testudo tabulata. The following are the
measurements of the bone:

Millimeters.

Length along the free border. . spcVegnyslae <a lara.gieeeaubs ve meses ye 6,4 = tee os
Length along the sutural border supposed t to join n the ninth peripheral........ 2
Greatest thickness Obthis borderencc ce ucaeant,.s les sete eens ese sscne cs 12
Length along sutural border supposed to join the seventh peripheral. ....... 37
Greatest:thicknessyotithis border: 2. Jes. de... sass oe bee se es ee eee te se 15

Cope’s statement that the greatest thickness is 11 mm. is an error. The border regarded
as the posterior is convex in outline. Cope thought that this was the anterior border. The
free border (on the left of Cope’s figure) is acute. The costal border is thickened, rounded,
and smooth. Evidently it formed no interlocking suture with the costal bones. The sulcus
(faintly seen in Cope’s figure) turns slightly forward at the free border of the bone. In the
thinner articular border there is a rough groove which received a ridge on the face of the ninth
peripheral. On the supposed anterior articular face is a ridge to fit into the next bone.

Cope’s fig. td represents another peripheral. The free border (on the left of Cope’s figure)
is acute and 27 mm. long. One sutural border (the lower of the fgure mentioned) is 15 mm.
thick and 36 mm. long. The opposite border is somewhat damaged but was evidently thinner.
In the thicker articular face there is a groove instead of a ridge. It is not improbable that this
is a second peripheral.

The bone represented by Cope’s fig. 1a is difficult of identification on account of its
damaged state of preservation. Cope speaks of it as ‘“‘a piece of the inguinal marginal, which
shows that this species has the fixed anterior lobe of the Emydidz.” Tinctead of “inguinal he
probably meant axillary. Quite certainly the bone belongs in either the axillary or the inguinal
region. The form and the great thickness of the border of the hinder lobe and the smooth
costal borders of the peripherals render it probable that this is rather a species of T estudo
than of Clemmys.

Clemmys insculpta (Leconte).

Testudo insculpta, Leconte, Lyc. Ann., New York, 111, 1830, p. 112.
Clemmys insculpta, BouLENGER, Cat. of Chelonians, 1889, p. 107——Corr, Jour. Acad. Nat. Sci. Phila.
(2), x1, 1899, p. 194-

Professor Cope, as cited in the synonymy, reports the finding of some bones, referred to
this species, in the Port Kennedy Cave, Pennsylvania. The remains were very fragmentary,
and there is a possibility that they may belong to some related but undescribed species.
C. insculpta is yet a living species in the eastern ned States.

Genus ECHMATEMYS Hay.

Shell emydoid. Neural plates mostly hexagonal, with the broad end forward. Pygal
bone short, the transverse sulcus crossing above it on the last suprapygal. Plastron suturally
articulated with both the peripherals and the costals. Axillary buttresses rising above the
border of the first costal and articulating with its inner surface. Inguinal buttresses ascending
above the peripherals and articulating ‘with the inner surfaces of the fifth and sixth costals.
Usually a well-developt epiplastral lip. Humero-pectoral sulcus usually crossing the ento-
plastron. Skull not certainly known, but almost certainly emydoid in general structure and
with the triturating surface of the upper jaw narrow and with no ridge, or a rudimentary one,
on each side. Choanz well forward. Lower jaw with a narrow triturating surface.

Type: Emys septaria Cope.

296 FOSSIL TURTLES OF NORTH AMERICA.

This genus is known principally from the Bridger Eocene, but also from the Wasatch and
the Uinta.

In the absence of definite knowledge regarding many parts of the anatomy of the Eocene
Emydide they have been usually, or sometimes provisionally, referred to the genus Emys.
More recently they have been supposed to belong to the North American genera Chrysemys
or Clemmys. The writer has exprest himself to this effect in 1902 (Bibliog. and Cat. Foss.
Vert. N. A., - 447) and again in 1905 (Amer. Geologist, XXXV., p. 332). Recently there has
come into the possession of the American Museum of Natural History a considerable number
of shells of Emydidz, especially from the Bridger deposits. Most of these specimens are some-
what damaged, but the majority of them are incondition to furnish abundant information.
Unfortunately no skulls accompany these remains. A single dentary bone only was found in
company w ith a good plastron and some fragments of the carapace. A study of these and
other accessible materials has demonstrated that most of the Bridger species of Emydidz
belong to a hitherto unrecognized genus, Echmatemys (Hay, Bull. Amer. Mus. Nat. Hist.,
XXL, 1906, p- 27), the essential characters of which are the strongly developt buttresses and
the feebly developt crushing surfaces of the jaws. In the existing North American genera of
Emy didz the buttresses rise little, if at all, above the lower border of the costals ani which
they come into contact. In Asia there are, according to Boulenger, four genera which possess
greatly developt axillary and inguinal buttresses, the latter articulating with the fifth and sixth
costals. All of these genera differ. however, from Echmatemys in having the triturating surfaces
of the jaws broad, and those of the maxilla furnisht with one 'or two longitudinal ridges,
The Eocene genus appears therefore to be well separated from both the American and ae
Asiatic forms.

The degree of development of the buttresses of Echmatemys appears to differ among the
various species. It is doubtful whether in any of them the buttresses ascend so high within the
carapace as they do in the Asiatic species. In E. wyomingensis the bases of the inguinal but-
tresses begin to rise perceptibly from the upper surface of the plastron at a point less than half-
way from the free border of the hinder lobe to the midline. In £. arethusa they spring from the
general level of the plastron at points about half-way between the border mentioned and the
midline. In other species they rise still nearer the midline. There appears to be less variation
in the width of the bases of the anterior buttresses. In £. wyomingensis these buttresses
ascend but little above the lower border of the first costals. In other species they ascend half-
way to the neural border of the costals. We find the same differences of development in the case
of the inguinal buttresses, the height to which they ascend varying from half-way to two-
thirds or more of the distance fon the lower to the upper border of the costals concerned.

The presence of these buttresses results in the production of a deep sternal chamber on
each side. In a specimen of 4. septaria, the width of whose carapace is 225 mm., the width
of the space between the inguinal buttresses is only about 80 mm.

The existence of these buttresses in E. septaria was recognized by Professor E. D. Cope

(Vert. Tert. Form. West, p. 130). In the case of his Emys houeiae sstana they were regarded
as less well developt. On the contrary, the present writer finds that they were quite as broad
and high as in E£. septarta.

The determination of the species of this genus offers great difficulties. There is among
them a great sameness in structure and general appearance. Few of them are markt by
trenchant characters. Yet there exist differences that we can not overlook. Had we the
skulls belonging to the shells in our possession, we might be relieved of some of our embarrass-
ment; but for the present we must be content with the knowledge and the conclusions that we
can derive from the carapaces and the plastra.

Another difficulty arises from the fragmentary character of the materials on which some of
Dr. Leidy’s species from the Bridger were establisht. If it is dificult to identify species when
we have practically whole shells, it is far more difficult when we have only a fragment—for
instance, the epiplastral lip or a fragment of the carapace.

In studying the materials in his ce the present writer has been compelled to recognize
several new species. It is not unlikely that in some cases he has erred; but it has appeared to
him that, better than the lumping together of forms which seem to be distinct, is their separa-
tion under special names, with careful descriptions, leaving to future writers, in the possession

EMYDID&, 297

of more and better materials, the determination of the value of these species. In establishing
these species the writer has drawn on all the structures that appeared to offer assistance, the
general form of the shell, the proportions of its various regions, the degree of the development
of the buttresses, the forms of the neural bones, the form of the epiplastral lip, the form and
size of the various scutes, etc. The condition and the variations of the same structures in
various living species have been examined. As a result of this study it is to be recognized
that in all the characters there is more or less fluctuation. We are often left in doubt whether
the next specimen examined will not contradict the conclusion just formed. It will require the
examination of many specimens to determine the range of the variations. It will be observed
that there exist considerable differences among the forms of the vertebral scutes, these being
in some cases relatively narrow and with parallel sides, in other cases relatively broad aad

367. 368. 369.

374- 372: 371.
Fics. 367-374.—Echmatemys sp. indet. Portions of skeleton. No. 11,525 Princeton University.
Fics. 367-373, X4, 374, XI.

367. Scapula and 367a coracoid. 371. Pelvis, right side.

368. Right humerus, dorsal surface. 372. Right feraur, tibial border.

369. Right humerus, radial border. 373- Right femur, tibia and fibula, dorsal surface.
370. Right humerus, ventral surface. 374. Terminal and penultimate phalanges.

with perhaps strongly bracketed sides. It is believed that some considerable reliance may be
placed in these forms as indicating specific differences. Little aid in the differentiation of the
species has been derived from the proportions of the plastral scutes. The usually well-developt
axillary and inguinal scutes seem to offer valuable characters. Sometimes the axillary scutes
extend backward and join broadly the fifth marginals; in other cases they fall far short of
these marginals. In some forms the inguinal scutes articulate with the sixth marginals, while
in others they lack much of attaining the marginals mentioned.

As already stated, little is certainly known Aloue the skulls of the members of this genus.
In the collection of fossil reptiles belonging to Princeton University there is a portion of a skull
of an emyd that in all probability belongs to some species of this genus. It is represented by
figs. 11, 12 and 13 of plate 45. It resembles much the skull of Chrysemys picta, altho larger.
It fiers especially in having the longitudinal ridge on the triturating surface of the maxilla

298 FOSSIL TURTLES OF NORTH AMERICA.

still less developt than in Chrysemys. The dentary bone of E. wyomingensts (figs. 398, 399)
agrees well with the maxilla of this skull.

Text-figs. 367-374 represent various parts of the skeleton of the same individual.

It is evident that this genus began its existence at least as far back as the Wasatch. An
examination of Cope’s Emys lativertebralis (Wheeler's Surv. 100 Merid., iv, part i, plate
XXVill, figs. 1, 2) shows that it possest strongly developt inguinal buttresses, which articulated
with the visceral surfaces of the fifth and sixth costals. The genus continued apparently until
the middle of the Uinta, as evidenct by the presence there of EF. callopyge and E. uintensis.

We are unable to determine as yet the relationships of this genus to Kachuga, Callagur,
Batagur, and Hardella, of Asia. It seems possible that some species of Echmatemys made its
way to that continent from America and thru a modification of its jaws gave origin to these
genera.

Key to THE DescRIBED SPECIES OF ECHMATEMYS.

A‘. Wasatch and Green River species.
a‘. No dorsal keel.

1. Neurals broader than long; gulo-humeral sulcus crossing behind entoplastron;

gular scutes reachingventoplastron\: cies etree eties saree ae ite ener lativertebralis

2. Neurals unknown; gular scutes not reaching the entoplastron; gulo-humeral
Sulcus crossing onventoplastrom: seweie--ie)clemuttie n sietets wale enelstes estar ae bree cthollensis

3. Sulci of carapace deeply imprest; costals swollen just outside of costo-vertebral
sulcisy bones: thick cand @neayiyag ise cte ate ereccestete ca erate cerebro ete erst et ee testudinea
4. Bones rather thin; beveled surface on upper side of hinder plastral lobe narrow... euthneta
a’. A dorsal keel; bones of carapace deeply imprest by sulci; bones thin............. megaulax

Ae: Bridger species.
a‘. Inguinal buttresses not extending half-way from free border of hinder lobe to midline.
1. Vertebral scutes and neural bones considerably longer than wide......... wyomingensis
2. Vertebral scutes and neural bones wider than long............... 1:8 .4> pusilla
ae Inguinal buttresses reaching half-way from free border of hinder lobe to midline.
b*. Third vertebral scute about seven-tenths its length.

1. Fourth neural octagonal........... Lididy idee abi Mite so SE chs setae eo haydent
b*. Third vertebral about eight-tenths its length.

2. Third vertebral about 0.78 its length; anterior lobe not expanded. ... stevensoniana

3. Third vertebral 0.80 its length; anterior lobe of plastron expanding in front
GE: aK Tees aoe eerie cate estore ova we canaieaic ie aia eieenten aps Meee siaee een tere ge arte septarta
4. Third vertebral about 0.81 its length; epiplastral lip contracted, tootht.... arethusa

5. Third vertebral 0.82 its length; axillary buttress rising high; marginal scutes
not high on) antenor ‘periphetals: «0.0m ageser- aac ce ees eee oe cyane

6. Third vertebral 0.82; humero-pectoral sulcus crossing behind entoplastron;
free borders of shell in front obtuse................... 000.000 shaughnesstana

68. Third vertebral about nine-tenths its length or more.

7. Third vertebral 0.87 its length; second vertebral still wider; anterior mar-
ginals rising high on peripherals... ..... cc. ..0. co. 200+ ies see eee neces acyrrhoe

8. Third vertebral 0.97 its length and urn-shaped; sulci not in deep valleys ;
axillary scutes not reaching the fifth marginal ..............--0..+.+--- egle

g. Third vertebral as wide as long; the sulci of carapace in deep valleys;
axillary scutes broadly joining fifth marginals..............+++++-+++5: naomi

a’, Little known species; said to have a very wide epiplastral lip and a deeply notcht
Pl ASELOMcceenicrsreierstetroveevstnlevatslar sates acre ae ee Hee Set os ate eee latilabtata

A’, Uinta species.

a'. Vertebral scutes urn-shaped, the first narrower than the others..................4- callopyge
a.” Vertebrals with straight sides; the front the widest.......... Pe eine nc dliniensts

Echmatemys lativertebralis (Cope).

Text-figs. 375-378.

Emys latilabiatus, Corr, Syst. Cat.,etc., Report to Engineer Dept. U.S. Army, 1875, p. 36; Ann. Report
Chief Engineers, 1875, App. LL, p. 1016, of reprint, p. 96. Not E. latilabiatus of 1872.

Emys lativertebralis Corr, 1877, Wheeler’s Sury. West 1ooth Merid., Iv, part ll, p. 53, plate xxvil, figs.
1-3; plate xxviii, figs. 1, 2; Amer. Naturalist, xv1, 1882, p. 991, fig. 10; Vert. Tert. Form. West,
1884, p. 129.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448.

EMYDID#&. 299

The known remains of this species were collected in the Wasatch beds of northern New
Mexico and were at first referred by Cope to his species Emys latilabiatus of the Bridger beds.
The specimens mentioned by Cope are at present in the U. S. National Museum and have been
examined by the writer.

The type specimen, that figured by Cope, was restored from loose fragments, and various
portions were missing. The length of the restored carapace (fig. 375) is given as 350 mm.
It follows from this that Cope’s figure is not half the size of nature, as is stated, but somewhat

less. The width was close to 284 mm. The front was broad and
rounded, the rear nearly truncate. The neurals are characterized
Neural. Length. | Width. by their great breadth as shown in the table herewith.
a | = The first suprapygal is 35 mm. long and 29 mm. wide.
On none of the neurals is there any trace of a median keel.

it oe oe

2 zn 36 The first pygal was 35 mm. long and 29 mm. wide. The second
4 oe 6 appears to have been about 21 mm. long and 49 mm. wide.
5 2 37 The nuchal bone had a width in front of about 58 mm.

£ 2 39 The costal bones presented no considerable differences in
i | ie the widths of their opposite ends. They are devoid of sculpture.

One of them, probably the third, had a width of 24 mm. in the

middle of its length and a thickness of 5 mm. On the inner
surface of the first and near to its peripheral border is a short articular surface for the reception
of the axillary buttress. This surface shows that the buttress did not ascend so high as did
that of some species of the genus. Above the scar for the buttress is a low ridge, that per-
taining to the rib of the first costal.

Fics. 375-378.—Echmatemys lativertebralis. Carapace and plastron of type. x}.

375. Carapace. Restored portions shown by interrupted lines. 376. Plastron. 377- Epiplastral lip, upper surface.
378. Right side and upper surface of hinder lobe of plastron.

The inguinal buttress articulated with the fifth and sixth costals. As stated by Cope and
shown by the type, the buttress ascended about two-fifths the distance from the lower border
of the costal to the upper border.

The free peripheral bones are large, thin, and recurved. The second and the eleventh are
flared the most. The peripherals of the bridge were not crost by a sharp keel running from
the anterior to the posterior free peripherals, a condition regarded as showing that the shell
was not deprest. The first peripheral had a length of 48 mm. along the free border. Its

300 FOSSIL TURTLES OF NORTH AMERICA.

height, or extent at right angles with the free border, was about 45 mm. The eighth peripheral
had a length along the free border of 41 mm. and a height of about 60 mm. The pygal had
a height of 30 mm. and a width of 35 mm. It was moderately recurved and transversely
convex above.

The sulci bounding the horny plates are well markt. Professor Cope describes the first
vertebral scute as being longer than wide, the second as long as wide, the third a little wider
than long, the fourth still wider; but a study of his figure does not in all respects confirm this
statement. The dimensions in the accompanying table are estimated from his figure, as the
bones of the carapace are now in a disturbed condition.

The costo-marginal sulci have pursued their course considerably below
the costo-peripheral sutures.

Professor Cope states that the length of the plastron (fg. 376) was

290 mm., and the specimen confirms the statement. He also informs us
a t that the bones were not thick; but no measurements are given. The ante-
65 ( rior lobe had a length of about 85 mm. and a width of about 140 mm. at the
50 (67 base. Cope’s measurements are somewhat greater than those here given.
5? 95 The anterior lip projects somewhat beyond the general curvature of the

lobe and is truncated. Seen from above the lip is very concave from side
to side and spout-shaped (fig. 377). On each side is a rather deep cleft which separates from
the remainder of the lip a rather prominent tooth. The thickening on the upper side of the lip
extends backward about 35 mm. At the hyoepiplastral suture the beveled horn-covered
surface has a width of about 25 mm.

The entoplastron has a length of 42 mm. and a width of 55 mm. Its thickness is 13 mm.
The bridge is about 110 mm. wide.

The length of the hinder lobe is 105 mm., 85 mm. along the midline; its width is 140 mm.
There is a posterior notch which has a width of 38 mm. and a depth of 20mm. The beveled
horn-covered surfaces on the upper side of the hinder lobe (fig. 378) have a width, at the
hypoxiphiplastral suture, of 27 mm.

At the crossing of the median longitudinal and the hyohypoplastral sutures the bones are
1o mm. thick. The greatest thickness of the epiplastrals is 16 mm. The inner border of the
beveled area, just behind the inguinal notch, is 13 mm.

The inguinal buttress begins to rise from the floor of the plastron at a line not quite half-
way from the free border of the lobe to the midline.

The gular scutes are 53 mm. long; the humerals, 32 mm.; the pectorals, 41 mm.; the
abdominals, 66 mm.; the femorals, 45 mm.; the anals, 34 mm.; all measured along the mid-
line. The humero-pectoral sulcus falls slightly behind the entoplastron, resembling in this
respect E, shaughnessiana (Cope). However, in one of Cope’s specimens the sulcus crept
over on the posterior margin of the entoplastron. It is not certain, on the other hand, that this
specimen (Cope, Wheeler’s Survey, 1v, plate xxvii, fig. 3) belongs to the present species.

Cope collected altogether five specimens of this turtle, two of them larger than the type,
and one much smaller. The latter showed traces of a median carina on some of the neurals.

Scute. Length. Width.

AP Wwe

Echmatemys cibollensis (Cope).
Text-fig. 379-

Emys (2)stevensonianus, Cope, Syst. Cat. Vert. Eocene New Mexico, Report to Engineer Dept. U. S.
Army, 1875, p. 36.

Emys stevensontanus, Core, Ann. Report Chief Engineers for 1875, Append. LL, p. 995 (of reprint, 75).

Emys ctbollensis, Corr, Wheeler’s Surv. W. 1ooth Merid., vol. 1v, part li, p. 57, plate xxvii, fig. 4;
plate xxviil, figs. 3-6.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, pp. 447.

The figured specimen of the type of this species belongs to the U. S. National Museum and
has the catalog number 2576. The carapace appears to be missing. Cope states that the
species was based on a single imperfect individual, in which some of all the characteristic
parts were present, except the neurals. Of the parts in his possession Cope figured the epi-
plastral lip, as seen from above and from below; the border of the hinder lobe, as seen from
above; and two peripheral bones,

EMYDIDA. 301

The type specimen was obtained from the Wasatch beds of New Mexico. The more exact
locality is given as the Gallinas River.

In his great work on the Vertebrata of the Tertiary Formations of the West, publisht in
1884, Cope exprest the opinion that his Emys crbollensis may have been founded on a larger
individual of his Emys euthneta of the “‘red beds” at Black Buttes, Wyoming. To the present
writer, after comparing Cope’s descriptions and figures and the types of the two forms and after
study of such materials of E. euthneta as are accessible, Cope’s opinion of 1884 seems erro-
neous, for reasons to be mentioned below.

The individual forming Cope’s type was somewhat smaller than the one which formed the
type of his E. lativertebralis. Its plastron was about 250 mm. long, carapace about 310 mm.
When Cope described this species he regarded its relationships as being with his Emys lati-
vertebralis, but he found the peripheral bones of the latter larger and thinner, and both the
anterior lobe of the plastron and the entoplastron relatively longer.

Cope figures no costal bones, but he gives the width of one as 22 mm., the thickness as
6mm. A costal of E. lativertebralis had a width of 24 mm. and a thickness of 5 mm.

Of the peripheral bones Cope says that they are not, or but little, recurved. He figures
two of these, but he does not state whether they are anterior or posterior peripherals. Evidently
both were imperfect. They probably belonged behind, and included the portion between the
free border and the costo-marginal suture. Cope gives the length of one peripheral as being
30 mm. and its thickness as g mm.; but the thickness of those fgured must have been about
12mm. The peripherals of FE. lativertebralis differ in being higher and thinner. On the other
hand, the posterior peripherals of £. euthneta were more recurved.

The anterior lobe of the plastron to the hinder border of the entoplastron is 65 mm. long.
The anterior lip (fig. 379) projected somewhat and is slightly concave in outline. At each side
is a rather prominent tooth, but there is no cleft separating it
from the remainder of the lip as there is in E. Jativertebralis.
The width of the lip, measured to the gulo-humeral sulci, is
54mm. The thickening on the upper surface of the lip extended
backward 23 mm. From each lateral tooth there extends back-
ward a broad ridge. At the hyoepiplastral suture the beveled
surface is 23 mm. wide. The entoplastron has a length of 36
Fic. 379.—Echmatemys cibol- ™M., a width of 55 mm., and a thickness of 7 mm. As stated

lensis. Epiplastral lip of type. by Cope, the bone was transversely diamond-shaped. To the
x4. No. 2576 U.S. N. M. present writer, the epiplastral lip appears to be quite different
from that of Emys euthneta.

The hinder lobe had a total length of g5 mm. and at the rear was a deep notch. There was
a broad beveled area at the border of the upper surface, and at the hypoxiphiplastral suture
this was 22 mm. wide. This surface appears to have been strongly imprest by the lines of
growth of the horny scutes. In Cope’s Emys euthneta this surface was relatively narrow (Vert.
Tert. Form. West, plate xviii, fig. 42).

The estimate of the present writer is that the length of the anterior lobe of E. lativertebralis
equaled 0.75 of the length of the hinder lobe; in £. crhollensis about 0.68.

The arrangement of the scutes of the anterior lobe of E. crbollensis is quite different from
that of FE. lativertebralis, since the gulars of the former do not reach backward to the ento-
plastron and the humerals overlap extensively this bone. The gulars of the present species had
a length of 25 mm. and, taken together, a width of 54 mm. In E. euthneta the gulars had
evidently a length fully equal to their combined widths.

There appears to be no good reason why this species should not be referred to Echmatemys.

Echmatemys ? megaulax (Cope).
Plate 45, figs. 14, 15; text-figs. 380-383.

Emys megaulax, Cope, Sixth Ann. Report U.S. Geol. Surv.Terrs., 1872 (1873), p. 628; Vert. Tert. Form.
West, 1884, pp. 129, 132, plate xviii, figs. 26-33.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902,
p- 448. : : ;

Emys pachylomus, Cope, Sixth Ann. Report U.S. Geol. Sury. Terrs., 1872 (1873), p. 629.

302 FOSSIL TURTLES OF NORTH AMERICA.

Professor Cope tells us that this species was based on fragmentary specimens of 5 or 6
individuals. Portions of these are now in the American Museum of Natural History, but the
bones figured by Cope are in the U. S. National Museum at Washington, and have the catalog
number 4061. The types and other specimens obtained by Cope were collected in the
Green River beds of the Wasatch formation, at Black Buttes, Wyoming, in 1872. A note in
Professor Cope’s handwriting, accompanying some specimens at Washington, states that they
were found in the first lignite beds of the Eocene at Black Buttes.

As stated by Cope, the markt peculiarity of the present species was the broad and abruptly
sunken sulci which separated the epidermal scutes. There was a dorsal carina and this was
conspicuously intersected by the sulci which crost it. The neurals are relatively broad. Cope
gives the length of one as 17 mm. and the width as 18 mm. A neural in the American
Museum, No. 1120, is 19 mm. long and 23 mm. wide at the broader end; its thickness at the
border for the costal is 5 mm. Sometimes the carina is broader in front of the sulcus which
crosses it and sometimes narrower. Sometimes (Cope’s figure 32) the sulci are shallow.
The neural which furnisht the figure just referred to has a thickness of 5.5 mm.; while
the others figured are only about 4 mm. thick at the borders. Cope’s fig. 28 does not repre-
sent a neural, but probably the hinder suprapygal. If so, the hinder marginal scutes extended
upon it. The figure is inverted. Fig. 14, plate 45, is taken from No. 1184 of the American
Museum. It is either the third or fifth neural.

The peripherals are rather thin, and they flare somewhat upward toward the tree border.
One figured by Cope (his plate xviii, fig. 29) had a width of 16 mm., a height of 23 mm., and

380. 381. 382.
Fics. 380-383.—Echmatemys megaulax. Peripherals and entoplastron. 1.

o. Section across posterior peripheral. No. 1184 A.M.N.H.

1. Right third or left seventh peripheral. No. 1184 A.M.N.H.

2. Section of peripheral of fig. 381.

3- Entoplastron of type of Emys pachylomus Cope. Specimen in A.M.N.H.

a thickness of 5 mm. It appears to be either the eighth or the tenth of the right side. In the
upper border is a pit fora rib. This, like others belonging to Cope’s specimens, had the sulci
deeply imprest. Cope’s fig. 31 1s almost certainly the Fipst right peripheral and is quite dif-
ferent from the corresponding bone of £. euthneta, being 5.2 mm. thick where it joined the
nuchal, while that of £. euthneta is g mm. thick. Cope’s fig. 30 appears to be that of the
second right peripheral, altho it does not join the first accurately. Fig. 15 of plate 45 is from
a peripheral of lot No. 1184. Its breadth at the free border is 19 mm.,; its height, 20 mm.; its
thickness, 5 mm. At the free border the edge is rather abruptly turned upward. Another
(text-fig. 380, section) is greatly thickened below the costo-marginal sulcus. Both of these are
posterior peripherals. Text-figs. 381, 382 represent the right third or the left seventh periph-
eral. Its width is 17 mm.; its height, 19 mm.; the thickness of the anterior sutural border,
7mm. On the inner face is a rough groove for the buttress. If this is the third peripheral it
presents in its acute free border a great contrast to that of E. testudinea. The sulci are not
broad and deep as they are in other posterior peripherals. It resembles other anterior periph-
erals in its moderate height.

There is little or no authentic material to throw light on the structure of the plastron of
this species.

A lot of bones, including portions of more than one individual, probably of more than one
species, bears Cope’s s label “Emys pachylomus, Black Buttes.” Among them is an entoplastron
which evidently is the one described by Cope in the Sixth Annual Report of the U.S. Geological

EMYDID. 303

Survey, page 629. This bone (fig. 383) has a length of 23 mm., a width of 30 mm., anda
thickness of 6 mm. It is quite certain that it does not belong with the other bones of the lot,
all of which belonged to smaller turtles. In this lot are peripherals which belong to FE. megau-
lax, having the scutal sulci deeply i imprest. On some costals and a neural present they are not
so deeply imprest. To the writer it appears that the peripherals are to be taken as the type of
this supposed species, and that these belong to FE. megaulax.

Cope (his plate xviii, fig. 33) has figured a costal bone, apparently the sixth of the left side.
The thickness of the posterior border is only 2.5 mm. while that of the anterior border is 7 mm.
This great thickness indicates that it united with the fifth costal to form a ridge for a strong
inguinal buttress. For this reason the species is referred provisionally to Echmatemys. The
proximal end of this costal shows that the sixth neural was short, 12 mm., at the costal border;
also that the fifth neural was probably octagonal. On this costal just outside of the area of the
fourth vertebral scute, there is a prominent boss.

So far as known at present, this species differs from E. testudinea in having the neurals
keeled and the keel notcht at the crossing of the sulci; and in having the posterior peripherals
thin and deeply and broadly imprest by the sulci. It must be stated, however, that little is
known about the neurals of F. testudinea and little or nothing about the plastron of E. megau-
lax. It appears that the shell of E. megaulax was comparatively thin; that of EF. testudinea
rather thick and heavy.

Echmatemys testudinea (Cope).

Plate 45, figs. 16, 17; text-figs. 383-388.

Notomorpha testudinea, Corr, Proc. Amer. Philos. Soc., x11, 1872, p. 475.

Emys testudineus, Cope, Sixth Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 627; Wheeler’s
Surv. W. tooth Merid., 1v, part ii, 1877, p. 58.

Emys testudinea, Cope, Vert. Tert. Form. West, 1884, pp. 129, 134, plate xxiii, figs. 12, 13.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 448.

Professor Cope states that this species was represented in his collection by 4 or more
individuals. These he secured in the Green River beds, as stated on his labels, tr miles east
of Evanston, Wyoming. ‘These beds are a portion of the Wasatch formation. All the indi-
viduals collected by Cope were imperfect and fragmentary. Of his specimens he presented
figures of only an entoplastron and the left border of the hinder lobe of a plastron seen from
above. These figured specimens are now in the National Museum, at Washington, with the
catalog number 4103,

In the Cope collection at the American Museum of Natural History there are several lots
of turtle bones bearing Cope’s labels stating that they are Emiys testudinea. Besides lacking
the figured specimens, these lots contain occasionally bones of more than one individual, and
we can not always be sure that they do not include parts of other species. To add to the con-
fusion, Cope’s table of measurements (Tert. Vert., p. 135) can hardly be relied on; for while
he gives the width of the plastron at the axilla as 86 mm., which is probably correct, he states
that the length of the plastron from the axilla is approximately 50 mm. Whether this is an
error or whether he referred to the anterior lobe alone, it is impossible to say. In that table
the thickness of the hyoplastron at the entoplastron is said to be 99 mm. and at the hypoplastron
as 5 mm., both of which statements are obvious errors. What the facts were we can only
surmise.

In one lot, that bearing the American Museum’s catalog number 1178, there are found
the proximal ends of two costal plates, almost certainly the third and the fourth of the right
side (plate 45, fig. 16). These are probably the ones mentioned by Cope in his description of
1884 as belonging to his second specimen. The fourth has a width of 17 mm., the fifth a
width of about 20 mm. As stated by Cope, the sulci run in grooves. These grooves are broad,
while the sulci themselves are very narrow. The surface of pciese costals is swollen just outside
the sulci, forming what Cope has called a “hump.” The thickness of the fourth thru this
hump is 8 mm. Where this costal articulated with the neural the thickness is 7 mm., while
that of the fifth is 8 mm. The rib-heads were not strongly developt. The external surface of
these bones shows the lines of growth of the horny scutes. The sulci which limited laterally
the second and the third vertebral scutes run at a distance from the neural border of only 5

304 FOSSIL TURTLES OF NORTH AMERICA.

mm. on the fourth costal and 6.5 mm. on the fifth. This indicates that these vertebrals were
very narrow, probably about 30 mm.

No. 1181 has a label in Cope’s handwriting which indicates that it is a portion of his
principal specimen (Vert. Tert. Form. West, p. 134), but only a part of the bones described is
present. Among these are portions of both the costals of the first pair. On the inner surface
of each is a sutural scar for articulation with the axillary buttress. This is 5 mm. wide and on
one of the pieces it is 17 mm. long, while the original length has been still greater. On page
143 of his Vertebrata of the Tertiary Formations of the West, Cope refers to certain bones
which he had formerly described as xiphiplastrals and as showing that the pubis had articulated
with the plastron. With this lot of bones is a rough drawing made by Cope which represents
one of these costals as a part of the plastron. The bone (fig. 384) is, however, without doubt
a costal, as Cope himself came to suspect. ‘The outside of this costal shows strong concentric
grooves produced during the growth of the first costal scute.

With the bones just described is what appears to be one of the hinder neurals. It is 16
mm. long, 17 mm. wide, and 7 mm. thick. The outer surface is rather rough. A fragment of
the plastron, probably shen its center, is g mm. thick. The right free border of the hypo-
plastron is represented by a fragment 23 mm. long. The edge is subacute. From this the bone
thickens rapidly to the inner border of the beveled surface on the upper side, where it is 9.5
mm. thick. This surface is 15 mm. wide and is bounded interiorly by a sharp groove.

Fics. 384-386.—Echmatemys testudinea. Costal and plastral bones.

384. Distal end of right first costal, inner surface. 2. No. 1181 A.M.N.H. Shows scar for axillary buttress.
385. Mesial portion of right hyoplastron. 4. No. 1179 A.M.N.H.
386. Free border of hypoplastron, with section (a) at articulation with xiphiplastron. 4. No. 1179 A. M.N.H.

No. 1179 may or may not all belong to the same individual, and the bones are probably
another portion of Cope’s principal specimen. The right hyoplastron (fig. 385) measures on
the midline 46 mm. At the midline and where it joined the hypoplastrals the thickness is 13
mm., and 12 mm. where it joined the entoplastral. The femoro-abdominal sulcus crosses 33
mm. behind the entoplastron. The humero-pectoral sulcus can not be distinguisht. A frag-
ment of the epiplastron has the free edge rather acute. The beveled surface is 16 mm. wide
and has a maximum thickness of g mm. Fig. 386 represents the upper surface of the left free
border of the hypoplastron and a section at the hypoxiphiplastral suture. The beveled area
has a width of about 20 mm. and at the summit the bone is 13 mm. thick. It is limited on the
inner side by a sharp groove. The beveled surface shows grooves produced by the scute—the
femoral. A fragment of the left xiphiplastron shows that this was only 36 mm. long on the
midline. There was evidently a posterior notch. At the anterior end of the median suture the
thickness of the bone is 8 mm.; posteriorly it thins down to 4 mm.

No. 1179 includes likewise the proximal half of a costal, almost certainly the sixth of the
left side (plate 45, hg. 17). The upper surface presents an elevation outside of the costo-
vertebral sulcus, as in the case of those previously mentioned. Anteriorly this sulcus is removed
6 mm. from the neural border, but posteriorly it has receded to a distance of 13 mm. This
indicates that the fourth vertebral expanded where the sulcus down the sixth costal departed.

EMYDID&. 395

The posterior border of the bone is 5 mm. thick, while the anterior sutural border is 8 mm.
thick. This is due evidently to the formation of a ridge on the fifth and sixth costals for the
reception of the inguinal buttress.

No. 1173 of the American Museum forms Cope’s third specimen. There is present a
portion of the first costal with the articular surface for the axillary buttress. There is a rough
drawing by Cope on which this bone is traced as belonging to the xiphiplastrals. This bone
belonged to a much larger individual than that represented by No. 1181, but the scar for the
buttress is no longer. This costal was at least 35 mm. wide and is 7 mm. thick where it joined
the first and second peripherals. The outer surface is smooth. With this lot is a portion of the
third right peripheral, excavated at the hinder end to form a part of the sternal chamber. Fig.
387 represents the sutural surface which articulated with the second peripheral. It will be
seen that the free border is broadly rounded. Fig. 388 presents the outlines and a view of
the anterior articular surface of a hinder free peripheral. This is recurved and has an acute
edge. The surface is uneven; and the sulci are narrow but sharply imprest.

No. 1258 appears to represent another portion of Cope’s principal specimen. Among the
bones is an entoplastron, but not the one described by Cope. The one which furnisht Professor
Cope’s figure 12 is not one-half the size of nature, as stated, but four-sevenths. The breadth of
the entoplastron of No. 1258 is 37 mm., its antero-posterior extent 24 mm., 2 mm. less than
that given by Cope. The longitudinal sulcus is very obscure, while te humero- pectoral
plainly crosses the bone about the middle of the length. The internal face of the bone is badly
weathered, so that little regarding the position of the bone can be determined therefrom.
The anterior border is damaged for most of its extent. There is a piece of the left hyoplastron
present, but it is impossible to say whether the two bones belong together. What appears to be
the free border of the right hyoplastron is present. The edges are acute. The beveled surface

on the upper side attains a width of 15 mm. and a
thickness of g mm. Two portions of the epiplastra
f are present, but their proper positions are difficult to
determine. They are acute- edged and they thicken
rapidly, the beveled surface attaining a thickness of
II mm. and a width of 14 mm. At the inner border

ee the thickness is diminisht suddenly.
387. 388. a The fragment of the hinder lobe figured by Cope
- (his fig. 13) appears to indicate the presence of a
EiGS Jo7 SND 388.-—Echmatemys testu- well-developt inguinal buttress, whose base extended
ae ee X1. No. 1173 inward about 20 mm. from the free border. At the
ieide wi. suture between hypoplastron and xiphiplastron the
387. Section at anterior end of thirdright peripheral. beveled upper border has a width of 15 mm. and here
chs sa set ola Secreta slow Hacites' »she bane 1s 8.5 mm. thick. The inner border of the
beveled surface is bounded by a considerable groove.
The free border is acute. The lower surface of this hinder lobe was flat transversely and
turned up posteriorly. The abdomino-femoral sulcus crost the plastron somewhat in front of

the inguinal notch.

Cope believed there was an undivided intergular, but the writer finds nothing to sustain
this opinion, and it is improbable. Undoubtedly the species is an emyd, and the presence of
an intergular, single or divided, would probably be unique. The proximal end of a costal, the
second or the fourth of the left side, has a width of 20 mm. and a thickness of 8.5 mm. The
longitudinal sulcus traverst the bone at a distance of 7 mm. from the neural border, showing
again that the vertebral scutes were very narrow. While the surface is uneven, there is no
swelling outside of the sulcus, differing thus from the others described.

Echmatemys euthneta (Cope).

Plate 46, fig. 1; text-figs. 389-391.

Emys euthnetus, Core, Sixth Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), p- 628.
Emys euthneta, Cope, Vert. Tert. Form. West, 1884, pp. 129, 133, plate xviii, figs. 34-42.—Hay,
Bibliog. and Cat. Foss. Vert. , 1902, p. 447.
20

300 FOSSIL TURTLES OF NORTH AMERICA.

This is one of the two species of emyd turtles described by Professor Cope trom the Green
River beds in the region of Black Buttes, the other species being E. megaulax. Emys euthneta
is said to have been represented by numerous specimens and to have been abundant in the
red beds which lie between those identified as belonging to the Green River and the Bridger

epochs at Black Buttes. The figured bones of the species are in the National Niscame at
Washington. They have the catalog number 4125.

In ‘he American Museum there are three lots, parts of the Cope collection, which appear
to belong to this species. The parts which were figured by Cope were 3 neurals, 4 peripherals,
1 epiplastron, and a part of 1 xiphiplastron. All these, it is stated, were found together and
were supposed to belong to a single individual. The neurals displayed no dorsal keel, the
scutal sulci were not deeply imprest, and the surfaces of the carapacial bones were smooth.
The length of the carapace of this individual must have been about 190 mm., the three neurals
taken together measuring 49 mm. One neural, probably the third (Cope’s fig. 34), had a
length of 19 mm. and a width of 15.5 mm., and a thickness of 4 mm. The A ele were not so
wide in proportion to their length as in E. megaulax. The peripherals resemble those of F.
megaulax, but they were not so deeply imprest by the sulci. The peripheral represented by
Cope’ s fig. 37 is apparently an anterior second. Itis 8 mm. thick where it joined the third.
Cope’s fis. 38 appears to represent the ninth peripheral of the right side, while his fig. 40 shows
probably mhe eighth of the left side. The border which articulated with the seventh is 7mm.
thick; that w hich articulated with the ninth is 6 mm. thick. Cope’s figure of the epiplastron
shows correctly that the lip projected abruptly for a short distance, and was little, if at all,
notcht at the midline. It is rounded off both above and below and has the free border obtuse.
Its greatest thickness is 6 mm. It is doubtful how near the midline the fragment approacht,
so that the width of the lip is uncertain. The hinder lobe is broadly notcht and the beveled
surface on the upper side is relatively narrow. The thickness of the border i is 5 mm. anteriorly.
Here the free edge is obtuse but posteriorly it becomes acute.

In the Cope collection of fossil reptiles, in the American Museum of Natural History,
there are four lots of bones which are labeled by Cope as having come from the “‘red beds”
of Black Buttes and were regarded by him as belonging to his Emys ys euthneta. These bear the
catalog numbers 111g, 1174, 1176, and 1182. Nos. 1176 and 1182 together present nearly
the whole of the plastron, except the epiplastron and the entoplastron. No. 1182 furnishes
most of the hyoplastron of the right side and most of the hy poplastron of the left side. These
bones are relatively thin.

The plastron had a total length of nearly 240 mm. At the crossing of the median longi-
tudinal suture and the hyohy poplastral suture the thickness is 7 mm. On account of some
missing fragments, the length of the hyoplastron can not be exactly determined. The anterior
lobe has a svidth of Ee 120 mm. The free border of the epiplastral process is acute, but
soon the bone thickens to8 mm. At the hy oepiplastral suture the beveled surface on the upper
side is 10mm. wide. No groove separates it from the surface beyond. The humero- pectoral
sulcus, deeply sunken, crosses the free border of the bone 14 mm. behind the suture just
mentioned. It appears almost certain that this sulcus did not touch the entoplastron. A
deeply imprest sulcus cut off an axillary scute, only a part of which was situated on the hyo-
plastron. The pectoro-abdominal sulcus crosses the bone at a distance of 1g mm. in front of
the hyohypoplastral suture, measured at the midline; measured at the free border of the bone
the distance is 30 mm. This sulcus is narrow and shallow. On the upper side of the bone,
on the outer two-fifths, a strong axillary buttress arises for articulation with the first costal.

The hypoplastron has a length of 70 mm. The width of the hinder lobe was close to 105
mm. The free border has an acute edge. The superior beveled surface has a width of 10 mm.
at the hypoxiphiplastral suture. No groove intervenes between this surface and that beyond.
At a distance of 20 mm. from the free border the thickness of the bone is 8 mm. The inguinal
buttress rises from the upper surface of this bone at a line less than half the divtance, from
the free border to the midline. The abdominal scutes of this individual had a length of about
58 mm. A fragment of the first costal (fig. 389) shows that the axillary buttress of this turtle
ascended a distance of 20 mm. on the inner surface of the costal.

Specimen No. 1176 (plate 40, fg. 1) presents the nearly complete hypoplastron and the
complete xiphiplastron. The individual was only shghtly smaller than the preceding, the

EMYDID. 307

hypoplastron having a length of 73 mm. The superior beveled border is 12 mm. wide. At the
inner border of this surface the bone is 12 mm. thick. Beyond the bevel the bone thins some-
what. Near the hypoxiphiplastral suture a groove develops just inside the beveled surface.
On the lower surface of the bone is seen the broad and deeply sunken abdomino-femoral
sulcus, which crosses at a distance of 40 mm. behind the anterior border of the bone. The
median longitudinal sulcus also has been broad and deep. There has been a large inguinal
scute, part of which lay on the hypoplastron.

The xiphiplastron has a length of 44 mm. on the midline. Posteriorly there was a notch
about 35 mm. wide and 10 mm. deep. The superior beveled surface (fig. 390, upper view and
section at hypoxiphiplastral suture) is separated from that beyond it by a sharp groove. The
greatest thickness of the bone, 11 mm., is at the summit of the bevel, but for some distance
it diminishes little. At the midline it has become reduced to about 7mm. The femoral
scutes measured 50 mm. along the midline; the anals, 25 mm. The femoro-anal sulci are
deep and wide.

No. 1119 furnishes, together with unimportant parts, a portion of the epiplastron,
including the lip. Seen from above, it resembles greatly the one figured by Cope (his plate

jae 391.

Fics. 389-391.—Echmatemys euthneta. Costal and plastral bones.

389. Inner surface of right first costal. <1. Specimen in A.M.N.H. Shows scar for axillary buttress.
390. Portion of hinder lobe, upper surface, with section of free border. 1. No. 1176 A.M.N.H.
391. Restoration of plastron. Mostly froin Nos. 1176 and 1182 A. M.N.H.

xviii, fig. 41a). Seen from below, it is observed that the gular scutes could have extended
backward hardly more than half-way to the entoplastron. The lip must have been at least
>2 mm. wide. The whole free border of the bone was obtuse. The superior horn-covered
surface is convex. Laterally the upper surface of the lip 1s swollen, and is about 7.5 mm. thick;
but at the midline the thickness 1s reduced to 4mm. The individual was a smaller one than
either of those just described. A fragment of a fifth or sixth costal is thickened on one side for
articulation with the sixth or fifth costal and has an articular surface for the inguinal buttress.
A peripheral and some fragments of costals show that the sulci were rather deeply imprest.

Lot No. 1174 contains many fragments of more than one individual, possibly of more than
a single species. Fragments of the fifth and sixth costals appear to indicate that the inguinal
buttresses were articulated principally with the sixth costal.

Fig. 391 presents a restoration of the plastron from the various bones described. The
epiplastral lip is taken from Cope’s figure.

After the preceding descriptions and figures had been prepared 3 additional specimens of
this species arrived at the American Museum of Natural History. These were collected in
1906 by the museum’s expedition sent into the deposits of the Wasatch in Wyoming. They
were all obtained on Bitter Creek, within about 20 miles of Black Buttes, where Cope obtained

308 FOSSIL TURTLES OF NORTH AMERICA.

his specimens. One of the new specimens, No. 6032, 215 mm. long and 175 mm. wide,
furnishes the shell complete, with the exception of the proximal ends of some of the median
costals and parts of two neurals. No. 6042, 270 mm. long and 227 mm. wide, furnishes a
complete shell, but has the carapace crusht down on the plastron. No. 6043, somewhat smaller
than No. 6032, is a nearly complete shell, lacking only a part of the rear of the carapace and
the hinder extremity of each xiphiplastron.

In No. 6032 the third neural is octagonal, whereas in No. 6042 it is hexagonal. In both
specimens the fifth is octagonal, the hinder angles being in contact with the sixth costals. In
No. 6032 the sulci bounding the vertebral scutes are deeply sunken, and in many places these
Jee _ _ sulci are bordered by crimpt ridges. In No.
No. 6032. No. 6042. 6043 also, all of the sulci are deeply sunken and

Vertebral. ae an ah me included between ridges of the bone.
ae. * e Length. th. . :
Psp lala Maniac (ie cascada The vertebral scutes have their sides more
‘ or less bracket-shaped. The dimensions of
I 2 53 I 3 ; :
5 e 38 38 ie those of Nos. 6032 and 6042 are given in the
3 47+ 4ot 50 39 accompanying table.
4 sf2) 49 al 49 The anterior lobe of No. 6032 is 52 mm.
5 45 55 49 68

long and g6 mm. wide at the base. The epi-
plastral lip is 4o mm. wide. Its anterior border
is excavated somewhat, but in the other specimens it 1s truncated. The upper surface of the
lip is concave from side to side. The horn-covered areas of the upper surface of this lobe are
narrow. In all the specimens the entoplastron is wider than long. It is not crost by the
humero-pectoral sulcus, altho in No. 6042 this sulcus skirts its posterior border. The bridge
of No. 6032 is 80 mm. wide. The hinder lobe has a length of 68 mm. and a width of 94 mm.
at the base. The notch in the rear is large, 45 mm. wide and 17 mm. deep.

No. 6043 presents the interior surfaces of carapace and plastron. The bases of the axillary
and the inguinal buttresses extend inward only about a third of the distance from the free
borders of the lobes to the midline. Each axillary buttress rises to a point about one-third the
distance from the lower end of the first costal to the midline of the first neural. The inguinal
buttresses are applied against the contiguous borders of the fifth and sixth costals and rise half-
way to the midline of the carapace.

Echmatemys wyomingensis (Leidy).
Plate 47, fig. 1; text-figs. 392-403.

Emys wyomingensis, LEIDY, Proc. Acad. Nat. Sci. Phila. 1869, p. 66; Ann. Report U. S. Geol. Surv.
Montana, etc., 1871 (1872), p. 367; Contrib. Ext. Fauna West. Terrs., 1873, p. 140, plate ix, fig. 5;
plate x, figs. 1, 2.—Copr, Ann. Report. U. S. Geol. Surv. Terrs., 1872 (1873), p. 626.—OsBorn,
Scorr and Speir, Contrib. Mus. Geol. and Arch. Princeton Coll., No. 1, 1878, p. 95.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 448.

Emys jeanest, Lerpy, Proc. Acad. Nat. Sci. Phila. 1870, p. 123; Ann. Report U.S. Geol. Sury. Wyoming,
etc., 1870 (1871), p. 366.

Emys jeanestanus, Lerpy, Amer. Jour. Sei. (@) 1, 1871p: 372.

Emys vyomingensis, Cope, Wheeler’s Surv. W. rooth Merid., 1v, 1877, p. 53; Vert. Tert. Form. West,
1884, p. 135, plate xxiii, figs. g-1T.

Chrysemys wyomingensis, Hay, Amer. Jour. Sci., xvit, 1904, p. 267, plate xiv, text-figs. 3, 4.

The present species was based by Dr. Leidy on an isolated left epiplastral bone which had
been sent to him by Dr. J. Van A. Carter and which had been obtained from the Bridger beds
somewhere in the vicinity of Fort Bridger, Wyoming. This bone is now in the collection of
the Academy at Philadelphia. It shows that the epiplastral lip, from one gulo-humeral sulcus
to the other, had a width of 60 mm. The anterior border is truncated, with a slight notch
mesiad of the sulcus named, so that a blunt tooth is suggested. The whole free border is acute,
least so just outside the sulcus. The median sulcus on the lower side apparently deviated
slightly from the midline, and this caused Leidy to suppose that there had been present a
narrow intergular scute. The thickness of the bone at the midline is 12 mm., and the same
behind each of the lateral teeth. On the upper surface there is a broad low ridge running along
the midline and on each side of this ridge a broad shallow groove. On this surface the gulo-

EMYDIDZ. 309

humeral sulci run directly backward. The bone is thickened backward a distance of 20 mm.
The horn-covered band is 17 mm. wide at the hyoepiplastral suture.

In 1870, as cited above, Dr. Leidy described his Emys jeanesi from a quite complete shell
found near Fort Bridger. In 1873 he referred this specimen to his earlier LE. wyomingensis.
An examination shows that its epiplastron is as nearly like that forming the type of E.w yoming-
ensis as could be expected in two individuals of the same species. The width of that of E.
jeanest is 54 mm.; the thickness at the midline, 11 mm.; behind the lateral teeth, 12 mm. As
in the type of EF. wyomingensts, there is, on the upper surface, a broad longitudinal ridge
flankt by broad grooves. The thickening of the upper surface extends backward about 20 mm.
The width of the smooth band, at the hy oepiplastral suture, is 13 mm. There appears to be
neither reason nor profit in regarding E. yeanesi as distinct specifically from £. wyomingensts.

The type of E. yeanes: was figured by Leidy. Diagrammatic figures are here presented
of both carapace (fig. 392) and plastron (fig. 393).

An examination of the interior of the shell of this type shows that the inguinal buttresses
were not so strongly developt as in most other species of Echmatemys. They arise from the

FIGs. 392 AND 393.—Echmatemys wyomingensis. Carapace and plastron of type of
Emys jeanest. XX}. U.S.N.M.

392. Carapace. 393. Plastron.

floor of the plastron at a line two-fifths the distance from the free border of the hinder lobe to
the midline. The distances are respectively 29 mm. and 69 mm. The width of the smooth
band, on the upper surface, at the hypoxiphiplastral suture, is 12 mm. The greatest thickness
of the bone here is 13 mm. The axillary scute is mostly missing, but it appears to have
extended backward only to the middle of the fourth marginal. The inguinal scute too is
short, reaching forward only to the middle of the seventh marginal.

No. 5988 of the American Museum furnishes the plastron complete and the carapace
lacking peripherals 3 to 6 inclusive, of the right side, the distal ends of the 4 posterior costals
of the same side, and the pygal. The specimen was obtained in 1903, on Little Dry Creek,
Wyoming, and belongs to horizon B. The shell has been crusht downward after burial and
the width considerably exaggerated. Both eleventh peripherals are present, but they stand
apart about go mm., whereas in life they were separated only by a pygal about 20 mm. wide.

The surface of the shell was smooth. There is no suggestion of a median keel. The length
of the carapace (text-fg. 394) was close to 335 mm. The width may be regarded as having

310 FOSSIL TURTLES OF NORTH AMERICA.

been about 250 mm. The anterior border is truncated. The free margins are nowhere
notcht. The nuchal is 50 mm. long, 43 mm. wide in front, and 75 mm. where widest. Its
anterior border, as well as that of the peripherals of the first pair, is acute. These bones are
rather thin, only 11 mm. The anterior and the posterior neurals are relatively broad, the
others narrow. ‘The dimensions of the neurals are shown in the table.

Dimensions of the neurals. Dimensions of peripherals. Dimensions of vertebral scutes.
No. | Length. | Width. | No. | Height. yeni: beri Noo!l|(eitenethe nee ee
I 42 30 1 38 43 | 25 1 64 a5 78
2 34 35 2 39 45 27 2 68 49 56
3 38.5 28 3 2 45 27 3 74 37 53
4 35 27 6 46 39 37 4 72 44 66
5 35 33 8 50 40 33 5 35 go+
6 26 30.5 |
7 18 34

8 28 28

The fifth neural is octagonal, due doubtless to an individual variation. The first supra-
pygal is 22 mm. long and 33 mm. wide.

‘The costal plates are usually about as wide at the upper end as at the distal end. However,
the third is 37 mm. wide proximally a and 27 mm. distally. The third has a height equal to only

—— ——

394.

at

bed . ae
Fics. 394 AND 395.—Echmatemys wyomingensis. Carapace and plastron.

No. 5988 A. M.N.H.

I

394. Carapace. 395. Plastron.

41 per cent. of the height of the first costal near its hinder border. The posterior peripherals
possess an acute free houder The first costal bone is hardly two-thirds as wide as high.

The dimensions of the peripherals are given in the table above.

The sulci are narrow and rather challew. The first and fifth vertebral scutes are broad,
the others are narrow, with nearly parallel sides. The dimensions of the vertebral scutes
are shown in tabular form above.

The costo-marginal sulci run about 16 mm. below the costo- peripheral sutures.

The plastron ( plate 47, fig.1; text-fhg. 395) is 304 mm. long. It is thick, especially at the
crossing of the longitudinal and the hy ohy poplastral sutures. "The length of the anterior lobe

EMYDID:. 31 I
is 82 mm.; the width, 143 mm. Thus the length is only 55 per cent. of the width. The epi-
plastral lip is 55 mm. wide and projects but little beyond the general curve of the lobe. The
beveled surface on each side of the lip (fig. 396) on the upper erate of the bone is only 15 mm.
wide and at the hyoepiplastral suture only 12mm. The thickened portion of the epiplastrals
above the lip extends backward only 16 mm., and where thickest, just mesiad of the gular
sulci, only 15 mm. ‘The free borders of the lobe are acute nearly to the lip. The entoplastron
is lozenge- shaped, 51 mm. long and 65 mm. wide. The bridge is 133 mm. wide.

The posterior lobe is g8 mm. long and 135 mm. wide, fie length being thus about 73 per
cent. of the width. The width is considerably less than the half of the length of the plastron.
In the type of £. jeanesi: the width is close to half the plastral length. Posteriorly in No. 5988
there is a broad notch. The beveled surfaces along the borders on the upper side (fig. 397)

390. 400.

390. 397. 401.
Fics. 396-401.—Echmatemys wyomingensts. Various bones.

396. Upper surface of epiplastral lip. <4. No. 5988 A. M.N.H.
397- a! surface of right side of hinder lobe of plastron. 4. No. 5988 A. M.N.H.

398. Left dentary bone, outer surface. X$. No. 5968 A. M.N.H.
399. Same dentary as fig. 398, seen from above. 3.
400. Upper surface of anterior lobe. <4. No. 6o10 A. M.N.H.

4o1. Upper surface of free border of hinder lobe of plastron. <4. No. 6o10 A. M.N.H.

have a width of 18 mm. at the hypoxiphiplastral sutures. Here the thickness of the bones is
14mm.

The gular scutes are 39 mm. long; the humerals, 36 mm.; the pectorals, 51 mm.; the
abdominals, 84 mm.; the femorals, 58 mm.; the anals, 37 mm.; all measured along the mid-
line. he axillary scute falls far short of reaching back to the fifth marginal; the inguinal
comes forward nearly to the sixth marginal.

The posterior buttresses extend ward from the free borders of the hinder lobe little more
than one-third the distance to the midline. Articulating with the fifth and sixth costals, they
rise about 44 mm., to a point nearly half-way from the lower border of these costals to the
bases of the rib-heads. The anterior buttresses appear to have risen about 20 mm. within the
first costals.

312 FOSSIL TURTLES OF NORTH AMERICA.

No. 5987 of the American Museum is referred to this species, altho it presents some impor-
tant differences. It is represented by a damaged shell from Grizzly Buttes. Its size is almost
exactly that of No. 5988. The carapace differs especially in having the

Width of | COStals modified so that their distal ends are alternately wider and nar-

Costal- | distaliend.| rower.” The proximal ends are not present. The dimensions of the costals
aa ~~ are shown in the table herewith.

2 41 The plastron is thick and heavy, the thickness of the bones at the

: a crossing of the longitudinal median suture with that! between the hypo-

5 27 ~~ ~~*pilastra “and xiphiplastra being 18mm. The anterior lobe has the same

6 38 proportions as in No. 5988, but its width is slightly greater. The thick-

i a ening on the upper side of the lip extends back 22 mm., thus being wider

than in No. 5588, but the lip above and below resembles closely that of
the type of Emys jeanesi. The hinder lobe is wider than in No. 5588,
being 150mm. The beveled surface on the upper side of the lobe has a width, at the hypo-
xiphiplastral suture, of 26mm. The inguinal 'scute’/runs\ for ‘a short, Idistance between the

403.

Figs. 402 AND 403.—Echmatemys wyomingensis. Carapace and plastron. }.
Yale University Museum.

402. Carapace showing supernumerary neurals, costals, etc. 403. Plastron.

abdominal scute and the sixth marginal. It is possible that in this specimen we have a dis-
tinct species, but the differences are probably due to individual variations.

No. 5950 of the American Museum, collected in 1903, at Grizzly Buttes, Wyoming, pre-
sents a portion of both carapace and plastron, both badly crusht. The specimen is peculiar
in the form of the first vertebral scute. This is longer than in No. 5988 and much narrower in
front. The length is 77 mm.; the width in front,60 mm. The lateral sulci bounding this scute
meet the first marginals at the middle of the length of the latter.

No. 5968 of the American Museum was collected in the western portion of Grizzly Buttes.
It furnishes a good plastron, various fragments of the carapace, some limb bones, and the right
dentary. The plastron has a total length of 306 mm. The specimen is valuable on account
of the dentary bone. It establishes the fact that the triturating surfaces of the jaws were
smooth and very narrow. Fig. 398 represents the left dentary as seen from the side and fg.
399 as seen from above; both of the natural size. A little of the bone at both extremities of this
dentary is missing. The portion remaining is 24 mm. long. The triturating surface is hardly

EMYDIDZ. 313
3 mm. wide, and it is transversely concave. In the figure this surface is shaded by horizontal
lines. The height of the bone is 7 mm. and the thickness nowhere exceeds 3.5 mm.

The right humerus of No. 5968 is preserved. The head is not globular, but consists of a
broad ridge, whose axis makes a small angle with the shaft of the bone, and a groove on the
radial side. The whole structure is exactly like that of the humerus of the species a Trachemys.

No. 6010 was collected on Little Dry Creek, Wyoming, and therefore belongs to horizon
B. It is represented by only the plastron. Fig. 400 shows the upper side of the anterior lobe
and fig. 401 the beveled surface of the hinder lobe. Both in front and behind, the beveled
horn-covered surfaces are wider than in No. 5988. These figures represent the condition found
in a certain number of specimens that must be referred to this species.

Figs. 402 and 403 represent a remarkable specimen which belongs to the Yale University
Museum. It was collected by one of Professor Marsh’s parties in 1874, in the Bridger Eocene,
near Millersville, Wyoming. It was described in the American Journal of Seiehice by Hay,
as cited above. It is interesting because of the presence of one extra neural, two extra pairs of
costal plates, one extra pair of peripherals, an extra vertebral scute, an extra pair of costal
scutes, and an extra pair of marginal scutes. “These supernumerary structures are not regarded
as of even specific value. It is to be observed, however, that the anterior lobe of the plastron
narrows more rapidly than usual and that the base of the hinder lobe is wider than usual;
indeed, more than half the length of the plastron.

6 specimens in Princeton University are referred to E. wyomingensis. ‘These are
numbered 10071 and 10072. In both of these the axillary and the inguinal buttresses extend
inward but little beyond the free borders of the bases of the plastral lobes. In this respect
these specimens differ greatly from those of £. haydenz, to which they might easily be referred.
Like the latter species, No. 10071 has the fourth neural octagonal, while No. 10072 has this
neural heptagonal.

“ae

Fics. 404-406.—Echmatemys haydent. Carapace and plastron. }.

404. Portion of carapace of type. U.S.N.M. 405. Portion of carapace. No. 1067 A. M.N.H.
406. Plastron. No. 1067 A.M.N.H

Echmatemys haydeni (Leidy).
Plate 47, fig. 2; text-figs. 404-410.

Emys haydent, Lewy, Proc. Acad. Nat. Sci. Phila. 1870, p. 123; Ann. Report U.S. Geol. Surv. Wyoming,
etc., 1870 (1871), p. 366.—Cope, Vert. Tert. Form. West, 1884, p. 137—Hay, Bibliog. and Cat.
Foss. Vert. N. A., 1902, p. 448.

Emys wyomtngensts, Lerpy, Ann. Report U.S. Geol. Sury. Montana, etc., 1871 (1872), p. 367 (in part);
Contrib. Ext. Fauna West. Terrs., 1873, p. 145 (in part), plate ix, fig. 6.

314 FOSSIL TURTLES OF NORTH AMERICA.

Dr. Leidy’s type of the present species was found near Fort Bridger, Wyoming, and
probably in the level now known as B. It belongs to the U.S. National Museum and has the
number tog. It consists of the anterior part of the carapace. This was figured by Leidy,
but the peripherals were omitted, having been found afterwards.
These have been included in fig. 404.

pe eee) See From the front of the nuchal to the anterior border of the
seventh neural is 255 mm. The length of the nuchal is 57 mm.;
I Be ge the width in front, 60 mm.; the greatest width, 75 mm. The
; a a fourth neural 1s octagonal. The table shows the dimensions of

4 3 27 the neurals.
2 The first peripheral measures 50 mm. along the free border.

The height is 48 mm. The sulcus between the costal and the

marginal scutes runs about 20 mm. below the upper border. The
dimensions of the vertebral scutes are given in the table below.

No. 1067 of the American Museum was found by Cope in the Bridger region. Fig.

405 shows the carapace; fig. 407, the plastron seen from below; while plate 47, fig. 2,

shows the plastron from above. This figure is to be

Width. compared with fig. 1 of the same plate, E. wyomingensis,

Vertebral. Length. = especially as to the origins of the axillary and inguinal

In front. | Greatest. huttresses: 7

In the American Museum is found the specimen

I 73 87 87 Fi ‘ , “

Le ‘0 4 described by Cope as belonging to this species. Its
3 80 37 53 number is 1072. It resembles the specimen to be
4 5e 95 described below, except that the rib-heads are broader,

having the diameter of 12 mm. where they leave the
carapace. The individual was slightly larger than No. 1067, but not enough larger to
account for the difference.

No. 1071 of the American Museum is a part of the Cope collection, but the exact locality
where it was found is not known. It came, however, from the Fort Bridger region. It belonged
to an individual whose shell was about 250 mm. long. The bones and sutures have an appear-
ance of immaturity. The features that characterize the specimens already mentioned hold
good here. The form was convex, as described by Cope. The fourth neural is octagonal, the
fifth quadrate. The vertebral scutes are proportionally wider than in the type, but this may
be due to less advanct age. Over the bridge the costo-marginal sulci ran very close to the
costo-peripheral sutures. On the costals are seen concentric grooves, which show the growth of
the horny scutes. On the first costal bone these are at an average distance apart of 7 mm.,
fact indicating rather rapid growth. The plastron 1 is not ereatly thickened, the front of the
hypoplastron being 11mm. The lip has a notch in front, w eich cuts off a tooth on each side.
Behind this tooth the thickness 1s 11 mm.

Another specimen in the American Museum of Natural History which is referred to £.
haydeni is numbered 3943. It consists of a shell lacking only some of the hinder peripherals.
It was collected in 1904, by Mr. Walter Granger, in the Bridger Eocene beds, about the middle
of the length of Cottonw ood Creek, and therefore belongs to the lower portion of horizon B.
The shell is crusht laterally, so that the height is probably greater than in life, being now 182
mm. The length of the plastron is 370 mm., from which it is estimated that the carapace had
originally a length of more than 400 mm. ‘The present width is 262 mm.

: The carapace (fig. 407) is smooth and the sulci are moder-
ately imprest. On the last neural and the suprapygals there is a
trace of a low keel. The nuchal bone has a length of 69 mm., a
width of 56 mm. in front, and a maximum width of about 80

Neural. Length. Width.

ry : mm. The neurals are broad. Two of these are octagonal, the
3 46 26 second and the fourth, but this is believed to be only an individual
fl . 31 variation. In the American Museum of Natural History there is
6 29 ae a specimen of Chelydra serpentina in which the same neurals are
: a2 39 octagonal. The table herewith presents the dimensions of the
§ 25 3

>

neurals of 3943.

EMYDID£. 315
The first suprapygal has a length of 34 mm. and a width of 29 mm. The second supra-
pygal is 38 mm. long and about 78 mm. wide.
The dimensions of the peripherals appear in the following table.

Dimensions of peripherals. Dimensions of vertebral scutes. Dimensions of marginal scutes.

Width = Width

No. | Height. eos aid No. | Length. of front. width. NO+ of front. height. free border.
I 49 53 34 I 88 85+ 854 I 20 27 49
2 49 5° I 2 82 59 66 2 25 30 49
3 50 47 28 3 gt 43 60 3 23 24 49
6 62 48 46 4 17 52 4 26 29 45
8 ae 42 7 30 40 SI

The free border of the nuchal and that of the first pair of peripherals are acute.

The vertebral scutes are long and narrow. The dimensions of these and the marginal
scutes are given in the tables above.

As stated already, the plastron (fig. 408) has a length of 370 mm. The anterior lobe is 102
mm. long and 163 mm. wide. The length is therefore about 63 per cent. of the width. The

407.

Fics. 407 AND 408.—Echmatemys haydent. Carapace and plastron. X4+. No. 3943 A. M.N. H.

407. Carapace. 408. Plastron.

free border is acute on the hyoplastrals, but becomes thickened and subacute and fnally
rounded near the lip. The latter is 63 mm. wide. This has the appearance of having been cut
off square in front, with a short, blunt tooth on each side. On the upper side (fig. 409), from
the acute free border of the lip, the bone thickens backward a distance of 25 mm., where
the thickness is 14 mm. The width of the horn-covered surface at the union of the epiplastral
and hyoplastral bones is 22 mm. The entoplastron has a length of 66 mm. and a width of 75
mm. The bridge is 148 mm. wide.

316 FOSSIL TURTLES OF NORTH AMERICA.

The hinder lobe is 11 mm. long and 160 mm. wide, the length being thus 70 per cent. of
the width. There is a posterior notch of considerable size. The beveled surface on the upper
side of the lobe, at the hypoxiphiplastral suture, is 29 mm. wide.

The gular scutes differ in size. That on the left i is a mm. long. The humerals are 42 mm.
long; the pectorals, 72 mm.; the abdominals, 84 mm.; the femorals, 69 mm.; the anals, 55
mm., measured to the end of the plastron. The axillary scutes are large, but they do not
reach backward to the fifth marginals. The inguinals are large and extend forward so as
just to touch the sixth marginals.

The inguinal buttresses extend far inward reaching at least half-way from the free border
of the base of the hinder lobe to the midline.

No. 6088 of the American Museum is referred to . hayden1. It was found at Henry Fork
Hill, 100 feet below the white stratum, in horizon C. The carapace had a length of about 400
mm. For a view of the upper side of the border of the hinder lobe see fig. 410.

E. haydent is to be distinguisht from £. wyomingensis by the axillary and inguinal but-
tresses. In the latter species the inguinal buttresses extend inward not more than one-third the
distance from the free border of the hinder lobe to the midline; while in E. hayden: they extend

409.

Fics. 409 AND 410.—Echmatemys haydeni. Portions of lobes of plastron. 4.

409. Upper surface of anterior lobe. No. 3943 A. M.N.H.
410. Upper surface of free border of hinder lobe of plastron. No. 6088 A. M.N.H.

inward at least half-way to the midline. Usually, if not always, the fourth neural of E. haydeni
is octagonal, but occasionally this is true of the same neural of E. wyomingensis. Usually the
upper side of the epiplastral lip of E. wyomingensts is short, the thickening not extending back-
ward so far as in E£. haydent.

E. shaughnessiana is to be distinguisht by the relatively wider vertebral scutes and the
thickened and obtuse free borders of the front of the carapace.

Echmatemys stevensoniana (Leidy).

Plate 48, figs. 1, 2; text-figs. 411-413.

Emys stevensonianus, Leipy, Proc. Acad. Nat. Sci. Phila. 1870, p. 5.

Emys stevensont, Ley, res Report U. S. Geol. Surv. Wyoming, etc., 1870 (1871), p. 366.

Emys wyomingensis, Lewy, Ann. Report U. S. Geol. Surv. Montana, ‘ete., 1871 (1872), p. 367 (in part);
Contrib. Ext. Fauna West. Terrs., 1873, p. 141, plate ix figs. 5 Hay: Bibliog. and Cat.
Foss. Vert. N. A., 1902, p. 448 (in part).

Dr. Leidy’s type of the present species was collected somewhere in the vicinity of Fort
Bridger, Wyoming, and therefore probably in the lower portion of the Bridger Eocene. His
specimen consisted of a portion of a carapace showing the whole series of neurals and the

EMYDID&. 317

proximal ends of several costals and a portion of the plastron. It is not certain that the two
portions of the shell belonged to the same individual, but it is probable that they did. These
bones are figured as cited in the synonymy. With them were figured and referred to the same
species a left epiplastron of another individual. This bone was barely mentioned in the original
description.

The type is in the U. S. National Museum. The piece of carapace bears the number 965;
the piece of plastron, the number 963. The original of Leidy’s fig. 4 of the plate cited bears
the number 976.

Later Dr. Leidy referred all these bones to his Emys wyomingensis. It 1s the present
writer's opinion that the two forms are not identical: but the fragment of plastron represented
by Leidy’s fig. 4 probably belongs to £. wyomingensts.

It is to be remarkt concerning the plastron described by Leidy that the free border of the
anterior lobe, from the humero-pectoral sulcus forward to the gulo-humeral, is broken away, so

Fics. 411-413.—Echmatemys stevensontana. Carapace and plastron.
No. 6084 A. M.N. H.

41. Carapace. XX}. 412. Plastron. X}4.
413. Upper surface of free border of hinder lobe of plastron. X34.

that the edge does not extend out as far as it naturally did. The edge of his drawing ought to
extend out about 14 mm. further than it does. Attention may be called to the form and
dimensions of the vertebral scutes of Leidy’s type, as they are represented in his figure.

In the American Museum of Natural History is a specimen which is referred to this species.
It is a nearly complete shell, lacking only the right epiplastron. This shell was collected in the
Bridger beds of southwestern Wyoming by the museum’s party in the year 1893. No further
details are recorded regarding the locality and the level. The matrix filling the shell is a coarse
sand in which are inclosed nodules of a greenish clay. The catalog number is 6084.

The total length of the carapace, in a straight line, is 355 mm.; the greatest width 240 mm.;
the greatest elevation 125 mm., but this in life was greater. The plastron is convex, an indica-
tion that the individual was a female.

In outline the carapace (plate 48, fig. 1; text-fig. 411) is a rather narrow oval, contracted
in front of the fore legs. It is slightly excavated above the neck and the hinder end is rather
pointed. Posteriorly the peripherals flare slightly upward. The free borders of the nuchal,

318 FOSSIL TURTLES OF NORTH AMERICA.
the front pair of peripherals, and the hinder peripherals are acute. The borders of the carapace
are nowhere notcht. The surface is smooth or relieved only by longitudinal striations.

The nuchal bone 1s 53 mm. long, 34 mm. wide in front,
and 60 mm. where widest, the table presenting the dimen-

Plements a EES We Met sions of the remaining median bones.

The table below presents the dimensions of some of
Neural 1 36 21 the peripherals and of the vertebral and marginal scutes.
Siar 2 7 ae The third peripheral has a height equal to 56 per cent.
Neural ao: 35 24.5 of the height of the first costal, from the neural to the
Neural 5 29 27 peripheral.
ee e: ze ee The vertebral scutes are relatively narrow and the
Neural 8..... 16 18.5 sides of the second and third are moderately bracket-
Suprapygal 1.. 33 25 shaped. The interior and posterior are expanded.
SETAE TERY Pen: 38 83 The nuchal scute is 10 mm. wide posteriorl nd its
Pygal am 38 Pp iorly ar

length is 1g mm. The costo-marginal sulci run well below
the costo-peripheral suture. The dimensions of five of
the marginal scutes are given in the table below, on the might.

The total length of the plastron (plate 48, hg. 2; text-fig. 412) is 317 mm. The anterior
lobe is 88 mm. long and 126 mm. wide at the base, the length being thus 70 per cent. of the
width. ‘The lateral borders run directly forward to the hyoepiplastral suture, then curve to
the lip. This had a width of 56 mm. and had a tooth on each side. The lip does not extend

Dimensions of peripherals. Dimensions of vertebral scutes. Dimensions of marginals.
Width = Width : : Length
: NV sreates = i 3
No. Height. of free of upper No. Length. . ah SES No. BGI aeetest of free
: : in front. width. in front. height.
border. border. border.
I 39 38 17 I 58 74 74 I 19 2 32
2 40 38 23 2 67 37 57 2 24 27 35
3 41 48 26 3 68 35 53 3 20 21 40
6 48 48 46 4 78 37 58 4 21 27 44
8 53 42 31 5 50 24 67 9 38 43 42

as far forward as the nuchal bone. The thickening on the upper side of the symphysis of the
epiplastrals extended backward 25 mm. The greatest thickness of the epiplastrals is 13 mm.,
and between these thickenings the bones are slightly channeled longitudinally. The thickness
of the symphysis is 13 mm. The horn-covered surface of the upper side of the epiplastron, at
the suture with the hyoplastron, is 18 mm. wide. The entoplastron 1s 47 mm. long and 57 mm.
wide. It is pointed in front; rounded behind.

The bridge has a width of 136 mm.

The hinder lobe is 105 mm. long, and 140 mm. wide at the base. The length is therefore
75 per cent. of the width. The buttresses arise far within the free border of this lobe. The
beveled surface of the upper lobe (fg. 413), at the suture with the xiphiplastrals, 1s 28 mm.
wide. The free borders of the lobe are acute. The posterior notch is about 28 mm. wide and
6mm. deep. The posterior buttresses appear to have extended at their bases about half-way
to the midline. How high they rise has not been determined.

The gulars are 45 mm. long; the humerals, 20 mm.; the pectorals, 63 mm.; the abdomi-
nals, gl mm.; the femorals, 52 mm.; and the anals, 45 mm.

The axillary scute is large, extending outward and backward to form contact with the
fhitth marginal for a distance of 6 mm. The inguinal scute extends forward within 13 mm. of
the sixth marginal.

From EF. naomi the species differs in having a smoother shell, with less deeply imprest
channels for the sulci, and in having narrower neurals. The carapace of FE. stevensoniana is
more contracted in front. &. shaughne sstana is set off by the bluntly rounded anterior border
of the carapace. From F£. «gle the present species is distinguisht by the larger axillary scute,
the deep grooving of the carapace, the lower position of the costo- marginal sulci, the relatively
broader and eioriey anterior lobe of the plastron, ete. In £. ocyrrhoé aie carapace 1s smooth,

EMYDIDZ. 319

the costal plates are alternately wide and narrower at their opposite ends, the beveled surface
of the upper side of the hinder lobe is narrower and the axillary scute is far from reaching the
fifth marginal. Other differences are noted under FE. oc yrrhoe. E. arethusa is distinguisht
by the contracted epiplastral lip and other characters.

E. stevensoniana is distinguisht from £. septaria, which it most resembles, by not having
the anterior lobe so much expanded, and by not having the costo-marginal sulcus so near the
upper edge of the peripheral bones. The form and rhe dimensions of the anterior marginal
scutes are quite different in the two species; and the pectoro-abdominal sulcus of E. steven-
soniana does not approach so closely at the midline the hyohypoplastral suture as it does in
both the specimens of FE. septarra in the American Museum.

Echmatemys septaria (Cope).
Text-figs. 414-420.

Emys septarta, Cope, 6th Ann, Report U.S S. Geol. Sury. Verrs., 1873, p. 625; Amer. Naturalist, xv1, 1882,
p. 992; Vert. Tert. Form. West, 1884, pp. 130, 139, plate xvi, hgs. g-13.—Hay, Bibliog. and Cat.
Foss. Vert. N. A., 1902, p. 448.

Echmatemys septaria, Hay, Bull. Amer. Mus. Nat. Hist., xxi, p. 28, fg. 1.

The type of this species is in the U. S. National Museum and consists of a tolerably com-
plete plastron; a portion of the central region of the carapace, including the third, fourth, and
fifth neurals, with portions of the second, se and fourth left costals; and a fragment showing
parts of the fifth, sixth, and seventh night costals and abutting peripherals. ahve type was
collected in the beds of the Washakie basin in the badlands of South Bitter Creek, W yoming.

All of Protessor Cope’ s illustrations are one-third the natural size, instead of one- fouethi:
Fig. 12 represents the piece w hich includes the three neurals mentioned and the corresponding
couenle: but the sutures bounding these bones are not shown. Moreover, the lower end of the
figure is the forward end of the fragment. The fragment illustrated by fig. 13 is not pee to
have had any connection with that of fg. 12; but che two pieces join accurately. If fig. 13
conceived as being swung around so that the end of the suture near its lower right- hand < corner
shall coincide with the end of the fracture seen in fig. 12, at the bottom of the concave
border on the right-hand side, the pieces will be in their natural relation.

The frst neural bone is 42 mm. long and 23 mm. wide. The next two neurals, all whose
form can be determined, are hexagonal, with the broad end forward. Of these the second is
35 mm. long and 30 mm. wide, w hile the third is 40 mm. long and 27 mm. wide. The periph-
erals are high, che fourth and fifth rising above the edge of the shell about 42 mm. The
nuchal and che peripherals abutting on it have sharp free borders: The nuchal is 50 mm. long
and 67 mm. wide.

The first vertebral scute is 67 mm. long and 80 mm. wide; the second 78 mm. long and
66 mm. wide at the point of he, brackets. The nuchal scute is narrow, abet 20 mm. All
the epidermal sulci are rather deeply imprest, but are not broad.

The inguinal buttresses extend well up into the carapace. They reach inward about
40 mm. fon the inner surface of the fifth costal plate. They are very thin in comparison with
those of E. shaughnesstana. Cope states (Ann. Rep. Hay den Sury. for 1872, P- 625) that this
buttress is connected with both the fifth and sixth costal plates. An examination of his type
shows that on the left side the union is almost entirely with the fifth costal, while the sixth only
just comes into contact with the buttress. On the right side the sixth takes more part in the
articulation. The position of this buttress probably varies somewhat in different individuals
of this species. In No. 6085, American Museum of Natural History, described below, it
comes into contact with the sixth costal. In No. 1077, American Museum of Natural His-
tory, the buttress rests on the middle of the fifth costal (fig. 414), and is hence far from the
border of the sixth; but this specimen appears to be abnormal in some other respects. “There
are considerable differences between Cope’s type and No. 1077 in the structure of the costals
and peripherals in the region of the inguinal notch. There is ae considerable difference in the
widths of the costals, | the peripherals coincide pretty closely with the ends of the costals.
In No. 1077, American Museum of Natural History, the arrangement is as shown in fig. 414.
This figure shows parts of the fourth, fifth, sixth, and seventh costals and the seventh, eighth,

320 FOSSIL TURTLES OF NORTH AMERICA.

and ninth peripherals. The dotted line shows the position of the inguinal buttress on the inner
side of the shell.

In the American Museum of Natural History there are various specimens which enable
us to add much to our knowledge of the structure of this species. Unfortunately, none of the
specimens is complete; and even when all are taken together, we are left in ignorance of much
of that part of the carapace behind the inguinal notch.

Among the materials referred to are some which were collected by Professor Cope in 1872,
but which do not appear to have been identified by him. One of these, No. 1077, furnishes the
greater portion of the anterior lobe of the plastron; the hinder lobe, except the hinder ends of
the xiphiplastrals; and a piece (fig. 414) of the carapace consisting of parts of fourth, fifth,
sixth, and seventh costals and the sixth, seventh, and eighth peripherals. The remains of
another individual, No. 1076, somewhat larger than the type, present the second and third
peripherals of both sides, many fragments of costals, nearly the whole of both epiplastra, and
a portion of both xiphiplastrals. A third specimen, No. 1079, from Haystack Mountain,
Wyoming, consists of the epiplastra of a still larger individual.

The best example of this species in the American Museum is numbered 6085, and was col-
lected in the Bridger beds of Wyoming, by the expedition sent out in 1893. The exact locality
and level are not on record. This individual lacks the whole of the carapace behind the

Fics. 414-416.—Echmatemys septaria. Carapace and plastron.

414. Portion of carapace. 4. No. 1077 A.M.N.H. Presents the seventh,
eighth and ninth peripherals and portions of fourth to seventh costals.
Dotted line shows course of articulation of inguinal buttress on inner
surface.

415. Anterior portion of carapace. 4}. No. 6085 A.M.N.H.

416. Plastron. X}4. No. 6085 A.M.N.H.

inguinal notch; neurals and costals immediately in front of this notch are crusht and damaged,
but the remainder of the carapace and the whole of the plastron are in fine condition. It is ac-
companied by another chelonite, No. 6089, which presents the anterior two-thirds of both
carapace and plastron in fine condition. Unless otherwise stated the following description is
derived from No. 6085.

The length of the carapace (fig. 415) can not be determined with exactness; but it was
close to 380 mm. The breadth was at least 210 mm. The elevation of the shell in life can not
now be determined. It is now 141 mm. high. The indications furnisht by the various speci-
mens are that the shell was quite convex. The plastron is nearly flat in the middle portion;
but the anterior lobe rises in front; and the hinder lobe is somewhat concave, especially near
the borders.

At the sides the carapace rises from the plastron upward and outward about 57 mm., then
turns steeply upward, and curves toward the midline of the back. The lateral carina on the
bridge peripherals is obtuse. ‘There is no dorsal carina; nor is the carapace especially
flared upward at the sides in front.

321

EMYDID&.
The neural bones are of moderate width; the table shows their dimensions:

The length of the nuchal was close to 56 mm.; its width along the free border about 42 mm.;
its greatest width is 67 mm. The free border of the nuchal and those of the first peripherals

Dimensions of neurals. Dimensions of peripherals.
ae sl oe | Width of | Width of |

No. Length. Width. No. Height. free costal
P : I border... | _ border.
I 42 22 I 44 37 17
2 34 2 2 40 36 24
3 49. if H *3. 45 43 she
5 45 45 45

The dimensions of the peripherals are shown in the table above.

Vertebral. Marginal.
Scute. Width. Height. Length
UES eel - of free
In front. Greatest. In front. | Greatest. border.
I 65 79 79 15 26 32
2 76 38 65 26 35 37
3 (he 38 6o+ 30 30 39

The upper surface of the carapace is nearly smooth, but is relieved by striation and faint
lines of growth; but these are not so distinct as they are on Cope’s type of E. septaria. The
second and third vertebral scutes are urn-shaped, expanded in front, and narrowed behind.
The first vertebral is the broadest. The dimensions of vertebral and marginal scutes are given

in the second table above.

= ieee
“6th.

neural

<4. No. 6085 A. M.N. H.

417. Upper surface of free border of hinder lobe of plastron.
418. Section across shell at the inguinal buttresses. Shows the sixth peripheral (per. 6), the
fifth costal plate (c. p. 5), and the right and left inguinal buttresses (r. ing., /. ing).

It will be observed that the second marginal is unusually high. This is true in both No.
6085 and No. 6089. As shown by both these specimens, the costo-marginal sulci run near the
costo-peripheral sutures ; in No. 6085, a few millimeters below; in No.6089, on the sutures.

The plastron (fig. 416) has a total length of 345 mm. The anterior lobe is 95 mm. long and
133 mm. wide at the base, the length thus being 71 per cent. of the width. The entoplastron is
50 mm. long and 53 mm. wide. Immediately in front of the axillary notch the lobe narrows a

21

Fics. 417 AND 418.—Echmatemys septaria.

322 FOSSIL TURTLES OF NORTH AMERICA.

few millimeters, then begins to expand and becomes wider than at the base. At the hyoepi-
plastral suture the lobe narrows again and passes rapidly to the lip. This is relatively narrow,

47 mm., is notcht at the midline, and is furnisht on each side with a blunt tooth. The epiplas-
trals thicken toward the lip and become 20 mm. thick. For some distance on each side of the
symphysis of the bones the thickness is reduced to 15 mm. The lateral expansion of the anterior
lobe and the lip form the most distinctive characters of this species.

The bridge has a width of about 138 mm.

The hinder lobe is 114 mm. long and 156 mm. wide. It is notcht behind, as in the other
species of the genus. The beveled surfaces (fig. 417) on the upper side of this lobe are 33 mm.
wide at the hypoxiphiplastral sutures. The posterior buttresses (fig. 418) are wide, beginning
to rise from the floor of the plastron at a line nearer to the midline than to the free border of the
lobe. They are articulated to the fifth and sixth costals and rise to a height of 65 mm. above
the floor of the plastron.

The gulars have a length of 54 mm.; the humerals, 31 mm.; the pectorals, 68 mm.; the
abdominals, 83 mm.; the femorals, 51 mm.; the anals, 4g mm., at the midline. The axillary
scute has not reacht the fifth marginal, nor the inguinal the sixth.

As in other species of this genus the posterior buttresses articulate with the fifth and
sixth costals. Fig. 419 represents the anterior lobe of the plastron of No. 1077, American

41g. 420.

-*
;

Fics. 419 AND 420.—Echmatemys septarta. Anterior lobe of plastron. 4. No. 1077 A. M.N.H.

19. Lower surface. 20. Upper surface.
4 420. Upp

Museum of Natural History. It will be observed how this expands in front of the base. Fig.
420 presents a view of the same bone seen from above. The width of the lip is indicated, also
the backward extension of the thickening of the epiplastrals.

No. 10303 of the collection at Princeton University is to be referred to this species. It
lacks only a small portion of the rear of the carapace and the tips of the xiphiplastra. It was
collected in 1878, at Twin Buttes, Wyoming, in the Bridger beds, belonging to level C or D.
The carapace was close to 335 mm. long. The interior ae the shell is cleaned out, so that all

parts are exposed. The sides of the anterior lobe are
Width. hatchet-shaped, as is peculiar to the species. “The horn-
Vertebral. Length. : covered areas on the upper side of the hinder lobe are 39
Anteriorly. Greatest. :
mm. wide.

The vertebral scutes are narrow at the ends, wide

1 6 a $7 a A . . A

; a e a in the middle, the measurements being given in the
3 78 39 76 accompanying table.

4 cs) ad 83 ‘These scutes are much wider in proportion to their

length than in Cope’s type and other specimens studied.
The sulci are broad and deeply imprest. It is possible that the specimen belongs elsewhere.
Nos. 1c073 and 10304 of the Princeton collection are likewise referred to E. septarza.

In the Philadelphia cig collection is the specimen which Leidy described as Emys
wyomingensts (Contrib., etc., pp. 148, 152, 153, No. 14). It is regarded by the present writer
as belonging to E. ae The sulci are deeply sunken and the surface of the carapace is
corrugated. The axillary and the inguinal scutes are well developt.

EMYDIDZ. 323
It is unfortunate that so many of the specimens which must be referred to this species are
devoid of exact records regarding their levels and localities.

Echmatemys arethusa sp. nov.
Plate 49, figs. 1, 2; text-figs. 421, 422.

The present species is founded on a single specimen which was collected by the American
Museum expedition of 1903 into the Badlands in the vicinity of Bridger, Wyoming. The
locality in which it was obtained is the western portion of Grizzly Buttes and the level the
lower portion of horizon B. The catalog number of the specimen is 5920.

The specimen lacks most of the left peripherals, all of those behind the ninth, and most of
the xiphiplastrals. It has likewise been crusht toward the left side.

The length of the plastron to the front of the xiphiplastrals is 225 mm., from which we
estimate that the whole length of the plastron has been close to 292 mm. and the es of the
carapace, 328 mm.

With the exception of faint longitudinal striations, the surface of the carapace (plate 49,
fig. 1) is smooth. The fourth vertebral scute is traversed by a low rounded keel.

The nuchal and first neural have been fractured so that

Meret a engi | Ween their exact dimensions can not be determined; but the free border
of the nuchal was close to 48 mm. and the length was close to 50

mm. The neurals furnish the measurements shown in the table.

I 2 25 r 7 > ~ . rn e .
5 4 a he tree border of the nuchal and first pair of peripherals is
= 33 . ~

3 35 28 acute. The sulci of the carapace are narrow and not deeply
“) Bo 27 imprest. The vertebral scutes are narrow and the sides of the
5 30 30 on

é - 36 second, third, and fourth are nearly parallel. The table below
7 17 33 presents the dimensions of some of the peripherals, and of some
8 21 30

of the vertebral and marginal scutes, so far as determinable.
It will be noted that the fifth vertebral is unusually wide.

The nuchal scute has a width posteriorly of g mm. Its length can not be determined.
The costo-marginal sulci run a moderate distance below the costo-peripheral sutures.

As already stated, much of the plastron (plate 49, fig. 2; text-fg. 421) is missing. The
length of the anterior lobe is 78 mm.; the width of its base is 144 mm. The length is therefore

Dimensions of peripherals. Dimensions of vertebrals. Dimensions of marginal scutes.
Width © Width > a ae _, Length
- ¢ = G = Pig jreates
No. | Height. of free |of upper || No. Length. ieee ae ie No. Height Greatest ee
barde Matis in front. width. in front. height. Bord
order. order. order.
I 41 42 26° I 64 68 68 I bie 28 354
2 39 43 27 2 66 4° 53 2 25 a9)
3 43 43 26 3 65 40 53 3 22 43
6 44 43 36 4 60 50 64 4 27 3 40
8 50 38 31 5 42 105+ 9 39 2 40+

only 54 per cent. of the width. From the axillary notches its free borders curve regularly to the
epiplastral lip. This is narrow, 40 mm.; large lateral tooth just within each gular sulcus.
There is a projecting tooth in the midline and on each side of it a minute tooth. On the upper
side of the epiplastrals (hg. 422) the gular scutes expand until they have a width of 65 mm.
The thickening of the epiplastrals on the upper side extends backward from the tip of the
median tooth 23 mm. ‘The greatest thickness of the epiplastrals is 13 mm. Just outside of
the gular sulci, on the upper side, the horn-covered surface is 12 mm. wide; at the suture with
the hyoplastrals, 14 mm. The entoplastron has a length of 50 mm. and a width of 58 mm.
The thickness of the plastron at the crossing of the median suture and that between the hyo-
plastrals and hypoplastrals is 15 mm.

The width of the bridge is 116 mm.

The length of the hinder lobe can not be determined. Its width at the base has been 146
mm. The inguinal buttresses arise about half-way from the border of the hinder lobe to the
midline,

324 FOSSIL TURTLES OF NORTH AMERICA.

The gular scutes are 41 mm. long; the humerals, 25 mm.; the pectorals, 55 mm.; the
abdominals, 70 mm.; and the femorals, 47 mm.
The axillary scute extends backward in a long point to come into bare contact with the
fifth marginal. The inguinal scute extends forward and joins narrowly the sixth marginal.
This species differs from E. naomi
in the form of the vertebral scutes, in
the lack of grooves for the sulci of the
carapace, in the very different form of
the front of the anterior lobe, and in
the axillary and inguinal scutes. The
\ broad neurals, the very broad fifth ver-
tebral scute, and the plastral lip differ-
entiate it from £. stevensoniana. The
\ acute anterior border of the carapace,
© the plastral lip, and the advanct posi-
a tion of the humero-pectoral sulcus sep-
. arate it from E. shaughnessiana. The
very different plastral lip, among other
characters, removes it from E. septarza.
E. ocyrrhoé has the costal plates dif-
ferentiated so that the ends are alter-
nately wider and narrower; the epi-
plastral lip is different from that of E.
arethusa; as are also the axillary and
inguinal scutes. £. egle has the verte-
Fics. 421 AND 422.—Echmatemys arethusa. Anterior bral scutes urn-shaped, the anterior
lobe of plastron. x3. No. 5920 A. M.N.H. lobe is very different, and the axillary
and inguinal scutes fall short respect-
ively of the fifth and sixth marginals.
The plastral lip of E. cyane is widely different; the axillary scute falls short of the fifth
marginal; the inguinal far short of the sixth; the second and third peripherals measure
together 64 mm. along the free border, while the same bones in the type of E. arethusa measure
85mm. E£. haydent, so far as known, differs in having the fourth neural octagonal, the verte-
bral scutes narrower, and a very different form of epiplastral lip.

421. Lower surface. 422. Upper surface.

Echmatemys cyane sp. nov.
Figs. 423-427.

No. 5924 of the American Museum of Natural History is a fragmentary specimen present-
ing most of the left side of the carapace, including four neurals, most of the left side of the
plastron, and a part of the right side. The specimen was secured by the expedition in 1903,
into the Bridger Eocene, at Grizzly Buttes, Wyoming. Its horizon is therefore that called B.

The length of the carapace (fg. 423) of this individual can not be exactly determined.
From the front of the nuchal to the hinder end of the sixth neural is 246 mm., from which fact

- it is estimated that the carapace had a length of 340 mm. Like
Pa a eee | write most of the Bridger species of the genus, this species had a thick

: shell. The surface of the carapace is mostly smooth.
Of the nuchal only a portion of the left side is present, but

; a this shows that its width in front was very close to 50 mm. The
; 33-5 30 greatest thickness is 15 mm. The first neural is not present.
5 29 30 Those preserved show the dimensions given in the table here-
6 22 30

with. These neurals have a thickness of 12 mm. The costals
have the two ends of each about the same width. The width of
the first costal equals 77 per cent. of its height.

The dimensions of some peripherals and of some vertebral and marginal scutes are given
in the table on the following page. The third peripheral is half as high as the first costal.

EMYDID&. 325

The seventh peripheral has at its hinder sutural border a thickness of 13 mm. A rather
prominent rounded keel runs along on the peripherals over the bridge.

The broadest vertebral scute is the first. The second and third are of moderate width, with
the sides somewhat bracket-shaped.

Dimensions of peripherals. Dimensions of vertebral scutes. Dimensions of marginal scutes.
Widt Vi ¥ 7 aes nae 7 _ . ..__) Lengt
| No. | Height. of Pe of ia Ree ene fess Mi No,, | eet | Greens re
| js b one So" in front.; width. in front. height.
eee wk order. border. 7 es) : border.
I 39 32 24 I 52 g6+ g6+ I 13 ae
2 40 344 | 20 2 80 es 60+ 2 | 20 24 37
3 41 36 22 3 73 40 60 4 23 40
6 47 43 44 4 . 47 60 Tide I a 2, 27 42
7 48 39 30

The costo-marginal sulci run at a distance of about 20 mm. below the costo-peripheral
sutures. On the under side of the nuchal and the first and second peripherals the marginal
scutes are 28 mm. wide.

On the visceral side of that portion of the carapace present (fig. 424) are exhibited the
axillary and the inguinal buttresses and the shoulders of bone against which they abut. The

424. seb /
423. oy,
Fics. 422-42¢.—Echmatemys cyane. Carapace and plastron of type. X }.
5 DES P Pp yp f
423. Portion of carapace.
424. Portion of carapace, inner surface. ax. b., axillary buttress; c. p.6, sixth costal plate; ing. b.,

inguinal buttress. On the left are seen sorne neurals and the bases of the rib-heads.
425. Two fragments of the plastron.

axillary buttress has a maximum width of 25 mm. and is 12 mm. thick. It ascends within the
first costal to a point 25 mm. or more above the upper border of the second peripheral, consider-
ably further than the buttress ascends in FE. wyomingensis, No. 5987 and No. 5988, A. M.N. H.
It abuts against an extremely prominent ridge, 12 mm. thick and 10 mm. elevation above the
general surface of the costal. This buttress and ridge are therefore very different from those
of the species just mentioned. The distance from the upper end of the buttress to the base of
the rib-head is less than the distance from the summit of the buttress to the border of the
second peripheral. In £. wyomingensis the former distance is much greater than the latter.

The posterior buttress articulates for a moderate distance against the inner surfaces of
the fifth and the sixth costals, about as far as in E. wyomingensts, but it appears that the but-

320 FOSSIL TURTLES OF NORTH AMERICA.

tress of the latter did not project so far from the inner surface of the carapace and was thinner.
In E. wyomingensis, as represented by No. 5987, at a point 20 mm. below its summit, the but-
tress projects inward from its artic ulation only 9 mm.; in £. cyane it projects inward 23 mm.,
a difference hardly to be regarded as merely individual.

The plastron (fig. 425) had a length very close to 325 mm. On account of the absence of
some fragments w hich connected parts which are present, the exact length can not be deter-
mined. The length of the anterior lobe
was very close to go mm.; the width was
not far from 130 mm. The epiplastral
lip has a width of 54 mm. It projects
but slightly beyond the general outline
ofthelobe. It is truncated, with an acute
free border. The lateral portion con-
sists of a stout tooth separated from the
remainder of the lip by a deep slit. On
the upper side the thickening of the
epiplastrals (fig. 426) extends backward
from the free border a distance of 28
mm. The epiplastrals are nowhere great-
ly thickened, the maximum being 11 mm.
The entoplastron had a length close to
49g mm., and the width has been 56 mm.
It is rounded in front and behind.

The bridge has a width of 132 mm.
The plastral bones are 21 mm. thick at

426. Upper surface of epiplastral lip. the crossing of the median longitudinal
427. Upper surface of left side of hinder lobe.
and the hyohypoplastral sutures.

The hinder lobe has a length of 113 mm. The width appears to have been about 146 mm.
The beveled surfaces on the upper side of the lobe (hg. 427) have a width of 28 mm. at the
hypoxiphiplastral sutures, of which width 21 mm. were covered with horny scutes. The thick-
ness of the bones at the sutures just mentioned is 12 mm.

The inguinal buttresses send their bases inward from the free borders of the posterior lobe
a distance of about 33 mm., almost half the distance to the midline. Thus they extend
inward further than in £. wyomingensis, but not so far as in some other species of the genus.

The gulars have a length of 57 mm.; the humerals, about 55 mm.; the pectorals, 55 mm.;
the abdominals, 90 mm.; the femorals, about 55 mm.; the anals, about 42 mm., all measured
at the midline. No part of the axillary scute is seen, but it failed by at least 28 mm. of reaching
the ffth marginal. It could have joined the anterior end of the fourth for only about 10 mm.
The inguinal scute lacks 10 mm. of reaching forward to the sixth marginal.

It is hardly necessary to compare at length this species with EF. oie eae sstana, Which has
a thick epiplastral lip and a thick rounded Gree border on the nuchal; or with EF. egle, with
its urn-shaped vertebral scutes; or with EF. arethusa, with its contracted epiplastral lip; or
with £. naomz, with its urn- shaped vertebral scutes and sulci lodged in deep grooves.

From EF. wyomingensis it differs in having the inguinal burresses reaching inward about
half-way to the midline, in having the axillary buttresses ascending nearer the neurals, in
having the epiplastrals thickened farther backward on the upper side of the symphysis and in
having wider vertebral scutes. EF. ocyrrhoé differs in having the vertebral scutes, especially the
second, considerably wider and in having the marginal scutes of the anterior half of the shell
rise higher on the peripherals. The American Museum specimen of £. stevensoniana has
almost exactly the size of that of the present species, so that comparisons may be readily
made. E. stevensoniana has narrower neurals and narrower vertebral scutes. The plastron of
E. stevensoniana appears to be thicker than that of E. cyane. Measured behind the abdomino-
femoral sulcus and one-third the distance from the midline to the free border, plastron of the
former is 8.3 mm. thick; of the latter 11 mm. The axillary scutes of E. stevensoniana extend
backward to the fifth marginal, while in £. cyane they fall far short of the latter marginal. In

Fics. 426 AND 427.—Echmatemys cyane. Plastron
of type. X$.

EMYDID.

327
E. stevensoniana the maximum thickness of the first and second peripherals at their artic-
ulation is 14 mm.; in £. cyane, 17 mm.

E. cyane differs from E£. haydent in the narrower inguinal buttresses, extending in the
former hardly half-way from the free border of the hinder lobe to the midline; in haydeni more
than half-way. In E. cyane the thickness of the second neural is 11 mm.; in haydeni, 14 mm.
The center of the plastron of EF. cyane is 20.5 mm.; that of E. hayden: is 25 mm. Probably,
however, it will not do to rely too much on the relative thickness of the neurals and of the
plastron. E. cyane has wider vertebral scutes than EF. haydeni, and the fourth neural is
not octagonal.

Echmatemys shaughnessiana (Cope).
Plate 50, figs. 1, 2; text-figs. 428-431.
Emys shaughnesstana, Copr, Amer. Naturalist, xvi, 1882, p. 992; Vert. Tert. Form. West, 1884, pp.
130, 135, plate xxiu, figs. 3-8.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448.

This species was first mentioned in 1882, but the only statement made regarding it by
Professor Cope is that its bones are very thick. In 1884 a description was publisht, illustrated
by figures of the carapace. No part of the plastron was figured. The specimen was found in

4
4
!

\
!

1
74
1

1

(

t

Hf

Aeey tes

Fics. 428-431.—Echmatemys shaughnesstana. Carapace and plastron of type.
428. Carapace. 4}. Parts restored are shown by interrupted lines.

429. Plastron. }. 430. Upper surface of front lobe of plastron. <4.
431. Upper surface of border of hinder lobe of plastron. <3.

the Bridger deposits of Wyoming, in 1872, on Cottonwood Creek, therefore about the middle
of stage B.

The type of the species is now in the possession of the Museum of Natural History and
bears the number 1069. A further description is here furnisht as well as figures of both cara-
pace and plastron. This is the more to be desired, since some of Professor Cope’s measure-
ments are found to be incorrect.

Professor Cope recognized that this species resembles in many respects Dr. Leidy’s
E. wyomingensts; and he has given what he regarded as differential characters. In general,

328 FOSSIL TURTLES OF NORTH AMERICA.

he regarded the bones of the carapace, especially the neurals, as much thicker than those of the
species just mentioned. It is doubtful if this is a correct statement. His statement that the
axillary buttresses are thicker than those of £. w yominge nsis appears to be true. The capitula
of the ribs are fully as broad as those of E. haydent, altho apparently not so thick. The periph-
erals are about as much recurved as those of E. wyomingensts.

The following appear to be characters distinguishing this species from E. wyomingensis:
The axillary Duteesses: and apparently also the inguinal, are thicker; the humero-pectoral
suture passes behind the entoplastron; the femoral scute extends inward on the upper surface
of the hinder lobe of the plastron as far as the inner border of the inguinal buttress; the
anterior border of the carapace has a much more obtuse edge; the free border of the epiplastron
is thicker and more obtuse; and the smooth band on the upper surface of the hinder lobe is
much wider, as is also the thickening on the upper side of the epiplastral lip.

From the type of E£. shaughnesstana there are missing the nuchal bone, except a fragment;
the eighth neural; both suprapygals; all the peripherals over both bridges, except a part of the
right fourth; some of the free peripherals of the left side and the seventh of the right side;
the distal ends of two left costals; the left half of the plastral lip; and parts of the bridge.
The forms of the nuchal, the eighth neural, and the suprapygals and pygal can be quite accur-
ately determined from the surrounding bones, so that from one side or the other of the shell we
have the means of determining nearly all the elements.

The total length of the carapace (plate 50, fg. 1; text-fig. 428), in a straight line, is 352
mm. Cope’s measurement of 380 mm. includes the curve. The width was approximately 270
mm. Near the midline in front the outline has been gently concave; the posterior margin has
been broad and rounded.

The table herewith presents the dimensions of the nuchal, neurals, and suprapygals.
The third neural has a thickness of 15 mm.; the third costal at its outer end is 7 mm. thick.

The costals show no remarkable peculiarities. The second
is only 28 mm. wide at its proximal end; 46 mm. at its distal

Element. Peengeiie Of, aE, end and 8 mm. thick near the border of the vertebral scute.

a Ma The fifth and sixth of the left side are, as an individual pecu-

Nuchal | 52 72 liarity, co-ossified proximally and measure together only 47
— eer a a mm.; whereas the corresponding ones of the other side are
Neural 3......| 38 36 distinct from each other and measure 597 mm. The periph-
Neural 4...... 32 24 erals resemble those of E. wyomingensis, but the anterior
aad rsa ae ae are higher and far less acute. The posterior are acute.
Neural 7...... | 32 23 However, they are not gradually thinned out, as are those
Aa bee 20 28 of E. wyomingensis, but come rather abruptly to an edge.
eel ve ; 65 in ae Cope’s figure (Tert. Vert., plate xxiii, fig. 6) represents this

coninon only moderately well. The first peripheral is 12.5
mm. thick where it joins the nuchal. The second is 45 mm.
high; its free border is 37 mm. long. ‘The third is 50 mm. high and 44 mm. along the free
border. On these the marginals ascend about 24 mm. above the free border of the bones.
Cope’s figure of the carapace represents the seventh right peripheral as present; but it is
not now in the collection. The corresponding one of the left side is present.
The width of the first costal bone is 60 per cent. of the length along the hinder border.
The scutes of the carapace are rather broad and their lateral sulci are bracket-shaped. The
nuchal is missing. The table below gives the dimensions of the vertebral scutes.
The upper borders of the marginal scutes run consid-

Dimensons Ofvertebrale erably below the sutures between the costal and peripheral
- bones. All the scutal sulci are narrow, but sharply
Scute. Length. _Width Greatest imprest.
33 in front. width. =

ia The plastron (plate 50, fig. 2; text-fig. 429) has a total
ersten tell cece ‘Wen 68 length of 342 mm., falling short of the length of the cara-
Vertebral 2... 60 37 58 pace only 10 mm. In the midline the length is 13 mm.
Vertebral 3... 71 39 58 less, on account of the notch. The anterior lobe is 97

Vertebral 4.. 75+ 45 65 l d heb : al aiked;
Vertis.) Were ae 96 mm. long and, at the base, is 144 mm. wide. e lip, as

seen from below, and measured from one gular suture to

EMYDID&. 329

the other, is 506 mm. wide. A notch in the border produces a blunt tooth on each side.
Beyond the notch the general curvature of the lobe is continued on to the midline. It remains
to be seen whether this character will persist in additional specimens. Seen from above (fg.
430), the lip is 66 mm. wide from one gular suture to the other, and continues backward 32
mm. The entoplastron is diamond-shaped, 55 mm. long, 65 mm. wide and 11 mm. thick. It
supports the hinder portion of the gular scutes, but no part of the pectoral scutes.

The hyoplastra occupy 72 mm. of the midline; the hypoplastra, 93 mm.; the xiphiplastra,
78 mm. The hinder lobe of the plastron is 107 mm. long; its width at the base is 145 mm.
The upper surface of the hypoplastron (fig. 431) behind the inguinal buttress was covered
with horny epidermis as far inward as the buttress extends, 31 mm. In all accessible specimens
of E. wyomingensts this surface is much narrower. The inner edge of the inguinal buttress
arises from the floor of the plastron at a line not half-way from the free border of the lobe to
the midline, resembling in this respect £. wyomungensts.

The gular scutes extend along the midline 42 mm.; the humerals, 42 mm.; the pectorals,
42 mm.; the femorals, 56 mm.; the anals, 55 mm.

The species differs from all others of the genus, so far as known, in having the humero-
pectoral sulcus cross behind the entoplastron.

434.

\ 4

Fics. 432-435.—Echmatemys ocyrrhoé. Portions of type.

432. Carapace. X}. 433- Plastron. x}.

434. Upper surface of anterior lobe of plastron. 4.

435. Upper surface of inguinal region of plastron, showing base of
inguinal buttress and free border of hinder lobe. 3.

Echmatemys ocyrrhoé sp. nov.
Figs. 432-435.

Two specimens in the American Museum of Natural History represent this species, No.
5933 and No. 5954. Of these, No. 5933 is taken as the type. It was collected in 1903 by Mr.
Walter Granger in the Bridger Eocene beds at Church Buttes, Wyoming. No. 5954 was
collected by the writer in 1903, in the western portion of Grizzly Buttes, Wyoming. Both
specimens therefore come from the lower part of the horizon B of the Bridger beds, the speci-
men from Church Buttes belonging probably to a slightly lower level.

No. 5933 presents the shell nearly complete. The second suprapygal, most of the pygal,
the eleventh peripheral of the right side and the distal ends of the eighth pair of costals are
wanting. No. 5954 furnishes the plastron backward as far as the hypoxiphiplastral suture
and various portions of the carapace, including the hindermost peripherals, but not the pygal.

FOSSIL TURTLES OF NORTH AMERICA.

WwW
Ww
1)

The type, No. 5933, measures, from the front of the plastron to the rear, 280 mm. The
length of the carapace (fig. 432) is 302 mm. The width in a straight line is 223 mm., thus
being 74 per cent. of the length. The shell has

Dimensions of neurals. Dimensions of costal bones. been little, if any, crusht downward, and the

: ; & : ahaa
Saar PRT height is now 108 mm. The front is slightly
No. Length. Width. No. of proxi- of distal incurved in front. The anterior border is sub-
malend. end. acute, and the anterior peripherals thicken rap-

idly. The surface of the shell is smooth.

1 37 24 2 29 35 S
5 as 38 3 31 26 The neurals are rather broad, having the
3 30 26 4 25 40 dimensions shown in the table herewith.

28 25 3 8 : :
4 > 5 33 The nuchal is 48 mm. long, 37 mm. wide
5 29 22 6 21 35 ¥ r
é 21 28 7 19 25 at the free border, and 63 mm. where widest.
7 18 3 The costal plates behind the first pair are
8 2 16.5

differentiated so that the proximal ends are
alternately narrower and wider, while the distal
ends are alternately wider and narrower. The dimensions of the costal plates are given in
the table above.

The table below shows the dimensions of the peripherals, the vertebral scutes, and
the marginals.

The height of the third peripheral is only 44 per cent. of the height of the first costal near
its hinder border. The width of this costal is 70 per cent. of its height.

The nuchal has a length of 14 mm. and a width of 13 mm. The vertebral scutes, except
the first, are of moderate width.

Dimensions of peripherals. Dimensions of vertebral scutes. Dimensions of marginals.
Width = Width Width : Length
No. Height. of free ofupper No. Length.) ante- Se No. Bie leat at fee
border. border. riorly. width. inifront}/ Height. border.
I 34 35 17 I 57 80 8o I 14 23 31
2 32 35 18 2 57 45 61 2 23 26 33
3 34 37 32 3 61 38 53 3 20 20 33
6 38 39 37 4 66 4! 58 4 20 22 37
8 8 36 25 5 50 34 . 7 30 33 37
8 33 37 36

The anterior lobe of the plastron (fg. 433) has a length of 76 mm., and a width of 113 mm.,
at the base. The borders continue straight forward to the suture between the hyoplastron and
the epiplastron, then curve toward the lip. The latter 1s 4g mm. wide, truncated and provided
with a short stout tooth on each side. It extends as far in front as the border of the nuchal.
The greatest thickness of the epiplastral bones is 13 mm. The thickening on the upper surface
(fig. 434) extends backward 24 mm. The horn-covered surface is 18 mm. wide, becoming
reduced to 16 mm. at the hyoepiplastral suture. The entoplastron is 47 mm. long and 53 mm.
wide. The anterior buttresses ascend only about one-third the distance from the lower to the
upper border of the first costals.

The bridge has a width of 118 mm. The hypoplastrals, in the midline, just behind the
suture with the hyoplastrals, are 13 mm. thick. This is reduced very little toward the anterior
and the posterior buttresses.

The hinder lobe has a length of go mm. and a width of 126 mm. The buttresses are
broad. The beveled surface (fig. 435) on the upper side of the hinder lobe is of only moderate
width, 19 mm. at the suture with the xiphiplastral. The posterior notch appears to have been
rather shallow.

The gular scutes are 40 mm. long; the humerals, 33 mm.; the pectorals, 48 mm.; the
abdominals, 73 mm.; the femorals, 38 mm.; the xiphiplastrals, at the midline, 45 mm. The
axillary scutes are quadrilateral and fail by 15 mm. of extending backward to the fifth marginals.
The inguinals lack the same distance of reaching to the sixth marginals.

No. 5954 is of almost exactly the same size as No. 5933, the length of the plastron to the
hypoxiphiplastral suture being 218mm. It varies in slight degrees from the type. The neurals

EMYDID&. 33!

present are a little narrower, as are also the vertebral scutes. The greatest thickness of the
nuchal bone is 16 mm. The ninth peripheral is 48 mm. high, 35 mm. wide at the free border
and 23 mm. wide at the upper border. Its greatest thickness is 13 mm. ‘This and the other
hinder peripherals thin out to an acute border. The pygal is missing but the eleventh periph-
erals show that it had a height of 23 mm. and that its right and left sides were convex. The
heads of the ribs of these specimens had a diameter of 8 mm.

The plastron differs in having a slightly narrower anterior lobe, 108 mm., a narrower
hinder lobe, 117 mm., and a narrower lip, 41 mm. The entoplastron 1 is 38 mm. long and
50 mm. wide. In both specimens the anterior lobe is very short in proportion to its width,
being only 67 per cent. thereof.

The rasoeets in which this species differs from £. wgle are stated under the species just
named. £. septaria differs in the expanded anterior lobe, in the greatly thickened epiplastral
bones, and in the contracted lip. The acute or subacute anterior border of the carapace of
E. ocyrrhoé distinguishes it from &. shaughne sstana.

E. ocyrrhoé differs from FE. hayden: in having the first vertebral scute much broader in
front and rapidly narrowing posteriorly. The other scutes are as broad as long or nearly so;
while in E. hayden: they are a aueh longer than broad. FE. stevensonianaisa relatiy ely narrower
shell, the width being only a little over two-thirds of the length; and more pointed in front and
behind. The anterior border of E. stevensoniana is more acute than in E. ocyrrhoé and the
suture between the first and second peripherals is 14 mm. thick, instead of 16.5 mm. The
epiplastral lips of the two species are different. Comparisons with F. cyane are to be found
under the latter species.

Echmatemys egle sp. nov.
Figs. 436-441.

‘Two specimens represent at present this species. “These were obtained in the Bridger beds,
near Bridger, Wyoming, in 1903. Of these, one, No. 5909 of the American Museum of Natural
History, is made the type. The locality where obtained is the western portion of Grizzly Buttes
and the level is the lower portion of horizon B.

The specimen is represented by the complete plastron, the anterior 5 pairs of costal plates,
the sixth costal plate of the right side, and a few peripherals. “The nuchal bone is missing.

An estimate based on the plastron makes it probable that the carapace had a length of
330 mm. The surface is smooth, except for some longitudinal striations on the neural bones.
The sulci bounding the epidermal scutes are rather deeply and uniformly imprest. The tables
below give the dimensions of the neurals and of the vertebral scutes, so far as presented.

There is little difference as respects
width between the proximal and the
distal ends of the costal plates.

Width Greatest The first right peripheral is repre-
in front.| width. sented by that portion in front of the
costo-marginal sulcus. — Its free border

Dimensions of neurals. Dimensions of vertebrals.

No. Length. Width. No. Length.

: - i. : 66 - ae is acute at the end next the nuchal bone
3 34 28 2 68 40 66 but rather obtuse at the end next to the
a 3° 27 4 ae 45 70 second peripheral. The extent of the
2 = i free border is 38 mm. The greatest

height of the second marginal scute was
about 29 mm. The greatest thickness
of the bone is 12 mm. A part of the right third peripheral is present and will be referred to
below. The fifth peripheral 1 is present and shows an angular ridge, along which the upper side
of the shell past abruptly into the lower side. This peripheral rises abor: e the ridge mentioned
a distance of 35 mm. and it has a width of 40 mm. The seventh peripheral has a length of
40 mm. along the free border. Its upper border is broken away. The maximum thickness
of the end articulating with the eighth is 13 mm., but it may have suffered some compression.
The eighth peripheral measures 33 mm. along the free border and it rises to a height of 45 mm.
The vertebral scutes are broad and urn-shaped, quite like those of E. naomr. The table
above gives the dimensions.

332 FOSSIL TURTLES OF NORTH AMERICA.

As shown by the fifth, seventh, and eighth peripherals the costo-marginal sulci ran near the
costo-peripheral sutures, being distant 8 mm. or less.

As stated previously, the plastron (fig. 436) has a total length of 300 mm. The anterior
lobe measures 87 mm. in length and has a width of 124 mm., the length thus being 70 per cent.
of the width. It contracts a little in front of the axillary notch, then runs directly forward some
distance in front of the hyoepiplastral sutures, then curves rapidly to the lip. The latter is
49 mm. wide. On each side it presents a stout tooth. Behind these teeth the thickness of the
bones is 11mm. The thickened portion of the epiplastral (fig. 437) continues backward 26 mm.
Outside of the gular sutures, on the upper side, the horn-covered surface is 18 mm. wide,
increases to 20 mm., and is reduced at the hyoepiplastral suture to 16 mm. The entoplastron is
35 mm. long and 60 mm. wide. The anterior buttresses arise some 15 mm. or more within the
border of the anterior lobe and rise to a height of at least 63 mm. They are about 30 mm.
wide and 7 mm. thick. The width of the bridge is 132 mm.

a
¢
\
x
s
\
*,
\

} 437. a | |

Fics. 436-438.—Echmatemys egle. Plastron of type.

436. Plastron. X}. 437- Upper surface of anterior lobe. 4.
438. Upper surface of hinder lobe of plastron. 4.

The hinder lobe is go mm. long and 126 mm. wide at the base, the length being thus 71 per
cent. of the width. Itis rather conspicuously notcht at the outer ends of the femoro-anal sulci.
The notch in the rear is rather deep, 13 mm., and its width is 36 mm. The beveled area on the
upper side of the hinder lobe (fig. 438) commences near the outer border of the buttress,
increases in width to the hypoxiphiplastral suture, where it is 23 mm. wide, and then diminishes
to1omm. The bases of the posterior buttress extend more than half-way from the border of
the hinder lobe to the midline. Their summits are fully 65 mm. above the upper surface of the
hinder lobe. They are 25 mm. or more wide and 7 mm. thick at half their height.

The gulars have a length, on the midline, of 47 mm.; the humerals, 22 mm.; the pectorals,
58 mm.; the abdominals, 72 mm.; the femorals, 47 mm.; the anals, 34 mm.

The portions of the third and fourth peripherals present show that the axillary scutes fail
to reach the fifth marginal scute by 20 mm. The inguinal scutes are not well displayed.

A second specimen referred to this species is No. 5976 of the American Museum. It was
obtained in 1903, in the western portion of Grizzly Buttes and in level B. It is represented by

EMYDID&. 333

the anterior three-fourths of the shell. It had almost exactly the same size as the preceding
specimen, the length from the front of the carapace to the xiphiplastron being 233 mm. The
specimen has been considerably crusht down-

eae FR a erent Deir von ward. It furnishes the whole front of the cara-
Ses pace (fig. 439), most of which was wanting in
Neural. | Length. Width. | Costal. Proximal} Distal the type. The nuchal has a maximum width of

idth. | width. : A
ie r 82 mm., but this would be less if the bone were

archt as usual. The free border of the bone

32 41

I 2 > ~

i 2 Ec 4 39 56 measures 39 mm. The front border of the cara-
3 36 26 | 4 29 38 pace is very acute to the beginning of the second
4 32 a7 | 30 2 sis ce ee ;

: ee. a 7 a Ff peripheral. The accompanying table shows the

dimensions of the neurals.

The costal plates of this specimen are modi-
fied more than those of the type. The widths of the ends are given in the table above.
The width of the first costal is equal to 65 per cent. of its height near the hinder border.

The dimensions of some of the peripherals and of the vertebral and marginal scutes are
shown below in tabular form,

The maximum thickness of the nuchal and the first peripheral at their suture is 12 mm.

Dimensions of peripherals. Dimensions of vertebrals. Dimensions of marginals.

(eer | Width | Width See anny Teva toe | Length

: | Width | Greatest Height Greatest | ig
No. Height.) of free of upper) No. Length. in front.| width. No. in front.| height. of free
a ____ border.) border, a Mice. er border.

I 40 35 20 I 55 79 | 79 I 19 24 31

2 38 37 19 2 65 39 | 70 2 23 28 35

3 | 39 40 28 | «(3 68 38 | 67 3 20 21 40

4 36 41 38 4 45 | 80+ 4 21 254 35

|

The first and second peripherals are 12 mm. thick at their articulation. The maximum thick-
ness of the hinder articular end of the seventh neural is 15 mm.

The vertebral scutes resemble those of the type. The nuchal scute is 17 mm. long, 10
mm. wide in front, expanding to 18 mm. behind. The
marginal scutes have the dimensions given in the table
above.

The surface of the carapace is smooth, except that
on the neurals and proximal ends of the costals there are
fine longitudinal striations.

From the plastron the xiphiplastrals are missing.

The length of the anterior lobe is 82 mm.; the width
of the base is 130 mm. The length is therefore only 63
per cent. of the width. It is possible that this is a sexual
difference, the lobes of the type being somewhat narrower.
The width of the epiplastral lip is 54 mm. The upper
surface of the front of the lobe resembles that of the type,
except that there is a broad channel on each side of the
midline, extending out to the lateral tooth. The horn-
covered areas of the upper surface resemble those of the
type. The bridge is 130 mm. wide.

The hinder lobe is 141 mm. wide. It will be
observed that both the anterior and the posterior lobes
fuck usin E piemapevene,t Care are wider than those of the type. The beveled surface on

pace. Xt. No. 5976 A.M.N.H.__ the upper side of the hinder lobe is 25 mm. wide.
The gulars have a length of 40 mm.; the humerals,
23 mm.; the pectorals, 64 mm.; the abdominals, 79 mm. The axillary scutes fail of reaching
the fifth marginal by 14 mm. The inguinal scutes extend forward so as barely to meet the
sixth marginals.

334 FOSSIL TURTLES OF NORTH AMERICA.

‘This species appears to be most closely related to E. ocyrrhoé. In E. egle, as compared
with £. ocyrrhoé the vertebral scutes are wider and more distinctly urn-shaped, the neurals are
broader, the carina over the bridge, on the peripherals, appears to have been more angular,
the beveled areas on the upper side of the epiplastron are somewhat wider; those on the upper
side of the hind lobe are considerably wider. The front border of the carapace of E. egle is
more acute and the bones are not so thick. As shown by the specimens, the eighth peripheral
of E. eagle is only 12 mm. thick where it joins the seventh, whereas in £. ocyrrhoé it is 17 mm.
thick. In the second specimen of EF. egle the thickness of this bone is 15 mm. In E. ocyrrhoé
the inguinal scutes did not reach the sixth marginals. As compared with E£, ocyrrhoé, No.
5954, the rib-heads are much stouter, the diameters of the former being about 10 mm.; in the
latter about 8 mm. The thickness of the first costal plate at the angle where it joins the nuchal
and the first peripheral is 9g mm. thick in £. egle, 11 mm. in FE. ocyrrhoé, No. 5954; the latter
being, besides, a smaller individual. In FE. egle, No. 5976, the thickness of peripherals one and
two at their articulation is 12 mm.; in F. ocyrrhoé, 17.5.

E. egle resembles E. naom: in the form of the vertebral scutes, but is distinguisht there-
from by numerous characters.

No. 10073 of the paleontological collection of Princeton University appears to belong to this
species. Its length is close to 300 mm., the width, 215 mm. The center of the carapace is

440. 441.
Fics. 440 AND 441.—Echmatemys egle. Carapace and plastron. XX}. No. 11515
Princeton University.

440. Carapace. 441. Plastron.
missing, removing most of the neurals and vertebral scutes. The first vertebral is 55 mm,

long, 78 mm. wide in front, 36 mm. behind. The fourth vertebral is 70 mm. wide where
widest—contracting behind to 27 mm. ‘The fifth had a maximum width of 64 mm.

The anterior lobe of the plastron contracts very little from the axillary notches to the
hyoepiplastral suture; then rapidly to the lip. There is a sharp notch at each side of this.
No. 11515 (figs. 440, 441) of Princeton University, lacking the hinder part of the shell, appears
to belong here. The nuchal scute is 80 mm. wide near the front, narrows to 64 mm., widens
again to 70 mm., then narrows to 43 mm. at the hinder end. The other vertebrals are expanded
at the middle of the length. The sulci are deeply imprest. The length from the front of the
carapace to the hinder border of the sixth neural is 255 mm. The axillary and the inguinal
buttresses are strongly developt, rising high on the inside of the carapace. The former extends
inward from the free border of the anterior lobe about 25 mm. The inguinal buttresses extend
inward from the free border of the hinder lobe 32 mm. They articulate with the fifth and
sixth costals. ;

EMYDID.

W
Ww
wn

Echmatemys naomi sp. nov.
Plate 51, figs. 1, 2; text-figs. 442-444.

The type of the present species is a finely preserved shell which was collected by the
American Museum expedition of 1903, in the Bridger beds of Wyoming. The locality is
Little Dry Creek, near the western part of Grizzly Buttes and the level is the lower part of
horizon B. The shell has suffered shght downward crushing,
but none of the characters have thereby been obscured. The

Element. Length. Width. “ - ;
number of the specimen 1s 5975.

Mek The total length of the carapace (plate 51, fig. 1; text-hg.

Uchal eee, 55 70 pe Es ose 5 Ae
aa ey saa 28 442) 1s 360 mm. The width taken across the middle is 263
Neural 2...... B 33 mm., and this is the greatest width. The front of the shell is
Neural 3....-. 33 33 in no way contracted. The hindermost peripherals appear to
Neural 4...... 32 3 have, b % fohely h " Th bl sn |
Neutalese cts a 31 ave been slightly notcht at the sutures. e table gives the
Neural 6...... 26 2 dimensions of the central row of bones.
eas : otc a i The width of the free border of the nuchal is 42 mm. ‘The
Suprapygal 1... 31 34 costals present little that is novel. The proximal ends are
Som ADEs 2..| 37 7° usually of nearly the same width as their distal ends, except that
DY Gall cerercvera! aus 31 39 i %

: the last three have their distal ends expanded somewhat.

The table below presents the dimensions of some of the
peripherals. The height of the third peripheral is 53 per cent. of the hinder border of the
first costal.

The nuchal and the first pair of peripherals have an acute free border. The greatest thick-
ness of the first is 19 mm. The free border of the second is subacute and passes into the
rounded free border of the third.

Dimensions of peripherals. Dimensions of marginal scutes. Dimensions of vertebrals.

Width = Width ; Length “| Width at /,

No. | Height. of free of costal No Detent: Poccateat at free No. Length. anterio reece

a igi: “in front. height. | eee Was rs n10r width.
border. border. Z ; border. ___end.

I 42 34 14 1 20 25 33 I 63 81 81

2 42 35 20 2 24 28 32 2 70 42 74

3 43 42 27 3 22 3 38 3 7° 8 7°

6 46 48 B 4 22 28 45 4 68 48 71

8 52 3 32 9 36 38 40 5 61 32 79

The posterior peripherals are flared moderately upward. They are rather thin and pass
out into a sharp, thin, free border. The thickness of the ninth at the longitudinal sulcus is
g mm.

The first costal is four-fifths as wide, fore and aft, as it is long on the hinder border.

The upper surface of the shell is very uneven. Large parts of the sulci run in very deep
grooves. Between them the surface is usually rough and pitted. There is no keel. In the
middle of the nuchal there is a slight, broad, rounded, longitudinal elevation and a similar one
on the suprapygals and pygal. The sulcus running around the carapace on the nuchal, the
peripherals, and the second suprapygal, lies in a deep groove. This groove has so weakened
the peripherals in its course that the pressure has caused them to yield along this sulcus. The
sulci between costals 1 and 2 and between 2 and 3 lie in very deep grooves, especially at their
upper ends. The hinder ends of the sulci bounding laterally the three anterior vertebral scutes
lie in deep and broad grooves. The sulci between many of the marginal scutes occupy
deep grooves.

The nuchal has a length of 1g mm. and a width of 15 mm.

The dimensions of marginal scutes are shown in the table above.

The costo-marginal sulci run far below the costo-peripheral sutures.

The vertebral scutes are broad and rather strongly urn-shaped; their dimensions are pre-
sented in the table above.

The plastron (plate 51, fig. 2; text-fig. 443) has a total length of 326 mm. The front
extends somewhat beyond the border of the carapace. The length of the anterior lobe is 96

336 FOSSIL TURTLES OF NORTH AMERICA.

mm.; its width 128 mm. The length then has a high ratio to the width, being 75 per cent.
thereof. The lateral border runs nearly straight to a point some distance in front of the hyo-
epiplastral suture, then rounds rapidly to the lip. The lip is 53 mm. wide. It projects little
and is furnisht with a right and a left lateral tooth and 2 closely placed median teeth. Between
the lateral tooth and the midline the upper surface of this lip is considerably excavated. The
thickening of the epiplastrals on the upper surface (fig. 444) extends backward 30 mm. The
greatest thickness of these bones is 12 mm. The median space between these thickenings on
the upper surface is somewhat excavated. The free borders of the lobe are acute nearly to
the lip. The beveled surface on the upper side of the epiplastrals has a width of only 12 mm.
at the hyoepiplastral suture. The entoplastron is 50 mm. long and 60 mm. wide. The bridge
has a width of 137 mm. The hinder lobe is 98 mm. long and 143 mm. wide at the base. The
length of the lobe equals therefore about 69 per cent. of the width. There is a rather broad
notch at the rear of the lobe. Its width is about 12 mm. The beveled surface on the upper

Vics. 442 AND 443.—Echmatemys naomi. Carapace and plastron of type. }.

442. Carapace. 443. Plastron.

side of this lobe, at the hyoxiphiplastral suture, is 28 mm. wide. The bones here have a thick-
ness of 13 mm.

The anterior buttresses appear to arise but a short distance within the free border of the
base of the anterior lobe. The posterior buttresses reach inward from the border of the hinder
lobe half-way to the midline.

The gulars are 47 mm. long; the humerals, 31 mm.; the pectorals, 60 mm.; the abdomi-
nals, 86 mm.; the femorals, 53 mm.; the anals, 38 mm. The humero-pectoral sulcus cuts
across the hinder end of the entoplastron. The median longitudinal sulcus runs a very irregular
course.

The axillary scute is large and its hinder end joins the fifth marginal for a distance of 13
mm. The inguinal scute is also large, its outer boundary being 38 mm. long, and lacking 12
mm. of reaching the sixth marginal.

From all other described species this differs in the depth of the channels in which run most
of the carapacial sulci. From £. stevensonrana it differs also in having broader neurals and in
its broader, urn-shaped, vertebral scutes. ‘These scutes likewise distinguish it from £. shaugh-

EMYDIDZ. 337
nesstana. Furthermore, the free borders of the nuchal and first pair of peripherals are acute,
while those of E. shaughnessiana are rounded. In the type of E. shaughnessiana the humero-
pectoral sulcus passes behind the entoplastron; in £. naomz, across it.

In E. septaria the epiplastral lip is more contracted, the epiplastrals are very thick at the
sides of the lip, and the anterior lobe expands in front of the base.

In E. ocyrrhoé the vertebral scutes are narrower, the anterior marginal scutes extend up
farther on the peripherals, the costal plates have their opposite ends alternately wide and

narrow, and the horn-coyered surface of the upper

side of the posterior lobe is relatively much nar-

rower. E. arethusa has narrow vertebral scutes

and a contracted epiplastral lip.

E. egle resembles E. naomi in respect to the
neural bones and the form of the vertebral scutes.
The sulci of the carapace are not in deep grooves.

| The lateral peripherals of E. naomi rise much
higher above the margin of the carapace than
those of EF. egle, the fifth of the former rising 46
mm., in E. egle only 34 mm. On this periph-
eral of E. naomi the costo-marginal sulcus runs
15 mm. below the upper border of the bone; in E.
egle only g mm. below. The axillary scutes of
E. naomi are more strongly developt than in E. «gle, reaching backward and widely joining
the fifth marginals; while in FE. egle they lack much of reaching the fifth marginals. On the
other hand, the inguinal scutes of E. egle extend forward to the sixth marginals, while
those of E. naomi do not reach the marginals just named. The epiplastral lip 1s quite differ-
ent in the two species, and the anterior plastral lobe of EF. egle is relatively wider. The
neurals of E. naomi are considerably broader than those of EF. egle.
Dedicated to one of the world’s noble women (Ruth ty).

Fic. 444.—Echmatemys naomi. Upper sur-
face of epiplastral lip of type. xs.

Echmatemys pusilla sp. nov.
Figs. 445, 446.
Emys wyomingensts, Leipy, Contrib. Ext. Vert. Fauna West. Terrs., 1873, p. 148, No. 13.

This name is bestowed on a small turtle which was obtained by the writer in 1903 at
Grizzly Buttes, Wyoming. The number of the specimen in the American Museum is 5992.
The level is that known as B. The type specimen affords the greater part of both carapace
and plastron. The shell gives evidences of having been immature. The total length of the
carapace in a straight line appears to have been close to 125 mm. The upper shell (fig. 446)
was apparently quite convex.

The nuchal bone has a length of 24 mm.; a width of 19 mm. in front and an extreme width
of 28 mm. The free border is acute.
The greatest thickness is 4 mm.; the
border for articulation with the first
Nowell Lenethe |) Width: No. Tenet. ieee Bene peripheral is slightly less than this. The

neurals are broad. Their dimensions
are shown in the table; also those of

Dimensions of neurals. Dimensions of vertebral scutes.

1 14 1 I 25 30

2 iW 12 2 26 30 the vertebral scutes.

3 12.5 13 3 25 30 The second neural is octagonal.
2h 24+ r ae

2 ‘4 : 2 4 The next two are hexagonal, with the

postero-lateral angles truncated. From

the forms of the contiguous costals it
appears that the fifth neural had the same form as the fourth, that the sixth was four-sided,
the seventh and the eighth hexagonal, with the antero-lateral angles truncated.

All the costals are represented in whole or part. They are thin, about 2 mm. distally,
thickening proximally to about 3.5 mm. On the visceral surface of those of the first
pair the axillary buttresses ascend a considerable distance above the lower borders. At the

22

338 FOSSIL TURTLES OF NORTH AMERICA.

thickened junction of the fifth and sixth costals is an excavation for the inguinal buttress.
‘This ascended about one-third the distance from the lower border of the costal to the neural
border.

The first, second, and third peripherals have acute free borders and remains of the bridge
peripherals show that a sharp carina from the third peripheral continued backward to the
hinder peripherals. The costo-marginal sulci run just below the costo-peripheral sutures.
The second peripheral has a height oF 15 mm.; the third, of 12 mm.; the eighth and ninth, of
15mm. The eighth, ninth, and tenth are only slightly concave above. ita hg. 446 the last-
mentioned peripherals are placed too near the midline. Most of the vertebral scutes are
broader than long.

The plastron (hg. 446) lacks the hinder extremity. Its total length was not far from 110
mm. The anterior lobe is 38 mm. long, 58 mm. wide. The epiplastral lip is truncated, 25 mm.
wide, and furnisht with a blunt tooth on each side. On the upper side the lip is thickened
backward for a distance of 16 mm., where there is a sudden offset. The thickness of the lip

mS \
a
{
NO
5 a ichameer — 440.
j
te i

/

Fics. 445 AND 446.—Echmatemys pustlla. Plastron and carapace of type.

445. Plastron. 446. Carapace.

is about g mm. from one side to the other. The entoplastron is elongated and pointed in front.
Its length is 26 mm., its width 8 mm. The hinder lobe of the plastron has a width of 61 mm.
at the base. Its free borders are acute. “The horn-covered surface on the upper side is 11 mm.
wide and shows distinct impressions of the growth of the scutes. The thickness at the hypo-
xiphiplastral suture is 6 mm. The inguinal buttress extends inward from the free border of
the lobe little more than one-third the distance to the midline.

The gular scutes overlap somewhat the entoplastron, as do likewise the pectorals. The
latter scutes reach backward to the hyohypoplastral suture, a condition not known in other
species of the genus.

In his monograph of 1873, as cited at the head of this article, Dr. Leidy described,
as the young of his Emys wyomingensis, a small turtle which had been sent to him from,
Fort Bridger, Wyoming, by Dr. Carter. This specimen 1s now inthe collection of the Phil-
adelphia Academy.

The specimen agrees in all essential respects with the type of E. pusilla. It furnishes a
large part of both carapace and plastron. The nuchal bone and all the neurals are present,
except the hfth. There are 2 suprapygals. Both first costals are preserved and wholes or
parts of all those of the left side. The first right peripheral is in its place. All the peripherals
of the left side are present, except the fourth and sixth. The pygal is missing. Of the plastron

EMYDID&. 339

all was secured, except the right hyoplastron, a small part of the night hypoplastron, and the
whole xiphiplastron.

The length of the carapace was not far from 110 mm. There is a sharp keel on the nuchal.
This is carried back on the neurals, but is obtuse until the seventh is reacht. On this, but
especially on the eighth and on the suprapygals, it is sharp. The neurals are broad, as in the
type. The third, not the second, is octagonal. The seventh is 6 mm. long and 12 mm. wide;
the eighth, 6.5 mm. long and 11 mm. de: and is crost by the sulcus Benresn the fourth and
the fifth vertebral scutes. The first suprapygal is 8 mm. long on the midline, 6 mm. wide in
front and 10 mm. behind; and is deeply excavated behind for the second suprapygal. This
is small, only 5 mm. long and 7 mm. wide.

The plastron has a total length of 103 mm. The anterior lobe is 30 mm. long and 54 mm.
wide at the base. The epiplastral lip is 24 mm. wide, acute- -edged, extends backward on the
upper side 13 mm., and is 6 mm. thick. The upper surface is quite strongly imprest by the
lines of growth of the horny scutes. The axillary buttresses extend but a little distance within
the free borders of the base of the lobe. The entoplastron i is long and narrow, as in the type,
being 22 mm. long and 18 mm. wide. The bridge is 36 mm. wide.

The hinder lobe is 35 mm. long and 55 mm. wide at the base. In the rear there is a rather
deep notch. The free borders are acute. On the upper side, at the hypoxiphiplastral suture,

the horn-covered surface is 10 mm. wide. Here the

: Width | Greatest. bones are 5 mm. thick. The inguinal buttress extends
Vertebral. | Length. 5

in front. | width. inward about one-third the distance from the free bor-
7 - der of the lobe to the midline.
: 7 a 2 The sulci are very distinct. The dimensions of the
a ee 18 56 vertebral scutes are given in the table herewith.
4 22+ 26 The gulars barely reach the entoplastron. The
5 a = humero-pectoral sulcus crosses at about the middle of

the length of the entoplastron. As in the type, the pec-
toro-abdominal sulcus is carried back nearly to the hyohypoplastral suture. The femoro-
abdominal sulcus crosses the lobe in a nearly straight line. The femorals measure along the
midline, 1g mm.; the anals, 13 mm.

This species resembles in several respects Clemmys morrisia. It differs, however, in having
the free borders of the second and third peripherals acute, instead of obtusely rounded, and in
having the inguinal buttresses rise well within the free border of the plastron. The epiplastral
lip resembles in form closely that of C. morrisie, and it is markt on its upper surface with
similar ridges, though not so strongly developt.

Echmatemys? latilabiata (Cope).

Emys latilabiatus, Corr, Proc. Amer. Philos. Soc., x11, 1872, p. 471; Sixth Ann. Report U.S. Geol.
Surv., 1872 (1873), pp. 625, 626; Vert. Tert. Form. West, 1884, p. 138.
Emys latilabrata, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448.

The present species has never been hgured. In his work on the Vertebrata of the Tertiary
Formations of the West, cited above, Professor Cope stated that the type had been mislaid.
So far as the present writer knows, it has not been recovered up to the present time. It 1s
possible that at some time another specimen may be discovered that can be identihed by
means of the description. The striking characters of the species, so far as indicated by Cope’s
description, are the relatively great bread of the shell and the wide epiplastral lip. The
following is Cope’s latest description:

Represented by a perfect specimen of a tortoise of a broadly oval form, and somewhat terrestrial
habit. Its prominent characters are to be seen in the plastron, of which the posterior lobe is deeply
bifurcate. The anterior lobe is peculiar 1 in the unusual width of the lip- like projection of the clavic-
ular (“episternal”) bone, which is twice as wide as in E. wyomingensts, and not prominent. Bones
all smooth; margins of lobes of plastron thickened.

There are three scars, perhaps, of muscular insertions near the posterior margin of the plastron,
an oval one opposite to each lobe, and a round one opposite to the notch.

As compared with E. septarta this species has no such septa nor sculpture; the emargination of
the plastron is more open, and the lip much shorter and wider,

340 FOSSIL TURTLES OF NORTH AMERICA.

Measurements.

Meter.
Length of carapace. 0.255
Width of carapace ... d .250
Width of lip of plastron. .060
Depth of posterior notch 020

The temporary misplacement of the typical specimen of this species prevents my giving other
than my original description.

From near Black’s Fork of Green River.

This species was obtained in horizon B of the Bridger Eocene.

Echmatemys callopyge sp. nov.

Plate 52, figs. 1, 2; text-figs. 447, 448.

As type of this species the American Museum of Natural History possesses a large and
complete shell, No. 2087. It was collected in the year 1895, in the middle Uinta deposits near
White River, Utah.

The shell is slightly crusht over toward the left side, a part of the mght side is broken in,
and a portion of the left margin is somewhat damaged; but there is nothing to prevent the

Fics. 447 and 448.—Echmatemys callopyge. Carapace and plastron of type. X 4.

447. Carapace. 448. Plastron.

determination of all the external characters that the shell offers. It would require the inflicting
of much injury on the specimen to reach and examine the axillary and inguinal buttresses.
Hence their condition is not certainly known.

The form of the carapace (plate 52, fig. 1; text-fig. 447) 1s elongated oval, rounded in
front and pointed behind, with the median portion high and vaulted. The plastron is broad
and it lett but little space for the exit of the limbs.

The length of the carapace, in a straight line, is 438 mm.; its width is 270 mm.; its height
is now 153 mm. The latter dimension was doubtless somewhat greater during the life of the
animal. There is a rather broad elevation running along the midline of the first vertebral
scute and another on the last vertebral; elsewhere there is no indication of any carina. The
margin of the carapace behind the inguinal notches ts thin and comes to a sharp edge. This

EMYDID&. 341

region is not at all serrated; but it is somewhat flared upward. The surface of the shell
smooth. The sulci are narrow but rather deeply imprest.

The neural plates are in general hexagonal, with the broad end forward. The second to
the fifth, inclusive, have the anterior end more or less concave. Most of the neurals are longer
than broad, but the posterior are broader than long. The table herewith gives the dimensions
of the neurals.

Dimensions of ueurals. Dimensions of vertebrals. Dimensions of marginals.
aia a : Length
: F 7 Width Greatest . Height Greatest =
No. | Length. Width. No. Length. = ij No. > rea SS" | at free
; : in front. width. ia front. height.
; border.
1 52 an I 75 52 52 1 18 32 40
2 43 39 2 89 47 85 2 26 29 47
3 58 3 3 88 52 82 2 21 27 46
4 4! 37 4 96 59 87 9 45 47 45
5 4l 44 5 74 44 100
6 30 40
7 29 45
8 28 34

The nuchal is 68 mm. long, 50 mm. wide at the free border, and has a maximum width of
80mm. The first suprapygal is 33 mm. long and 29 mm. wide; the second 42 mm. long and
go mm. wide. The pygal has a length of 30 mm. and a width of 40 mm. The free border of
the nuchal and the first peripherals i Is acute.

The peripherals are high. In front, they extend upward above the margin of the shell
about 46 mm.; laterally about 62 mm.; at the inguinal notch, about 70 mm.; the most
posterior, about 28 mm.

All the vertebral scutes are longer than broad, except the fifth. The first is unusually
narrow. The sides of the median three are bracket-shaped. The dimensions are given in the
middle table above.

Besides the nuchal scute, there are on each side the usual 12 marginals. These do not rise
to the upper borders of the peripheral bones. The nuchal scute is very narrow, only 14 mm.;
its length is 16mm. The dimensions of the marginals are shown in the table above.

The plastron (plate 52, fig. 2; text-Ag. 448) has a total length of 410 mm. The anterior
lobe is 116 mm. long and 174 mm. wide. The posterior lobe is 135 mm. in length and 198 mm.
in width. The bridge is 155 mm. wide. The anterior lobe is slightly contracted just in front
of the axillary notch: then expands a little to the ends of the epiplastra; then curves slowly
to the truncated lip. The latter is unusually narrow, having a width of only 38 mm., being less
than one-fourth of the width of the anterior lobe. It is marke outwardly on a side by a stout
tooth, mesiad of which there is a notch. In the latter are three smaller teeth. On the upper
side of the bone there is, along the midline, a prominent ridge, 48 mm. long and bounded on
each side by a valley, the latter opening in front at the notch of the lip. At the hinder end of
the ridge is a transverse ridge, which passes outward and backward. About the middle of its
length the epiplastron has a thickness of 15 mm.

The length of the entoplastron is 72 mm.; the width, 74 mm. The hyoplastra are gf mm.
along the midline, and each extends laterally about 104 mm. The hypoplastra join along the
midline for a distance of 100 mm. The xiphiplastrals meet along the midline 85 mm. The
notch between their hinder ends is 15 mm. deep; the distance between the fips is 34mm.

There are the usual scutes on the plastron. The gulars, taken together, are 64 mm. wide
in front. They extend backward well on the entoplastron, their median length being 72 mm.
The humerals meet along the midline for a distance of 35 mm. The pectorals encroach on the
entoplastron. The suture between them is 74 mm. eae The abdominals extend along the
midline for 110 mm. The femorals are only 38 mm. fore and aft at the midline; but 93 mm.
at their outer ends. The anals occupy 66 mm. of the midline. On account of some crushing
the axillary scute can not be made out. It is certain, however, that it failed by at least 25 mm.
to reach backward to the fifth marginal. The inguinal scute lackt about 27 mm. of extend-
ing forward to the sixth marginal.

342 FOSSIL TURTLES OF NORTH AMERICA.

The very narrow first vertebral scute distinguishes this species from all others, especially
from E. uintensis, which also comes from the Uinta formation. From many species it is dis-
tinguisht by the rather broad vertebrals succeeding the first. The narrow epiplastral lip and
the longitudinal ridge on the upper side of the symphysis are peculiarities. The femoral
scutes are unusually narrow at the midline. The species resembles somewhat FE. septaria
(Cope), but the vertebral scutes of the two are different, and the epiplastron of E. callopyge
appears not to have been so greatly thickened as in E. se ptarta.

Echmatemys uintensis sp. nov.
Plate*s3), figs. 1,2.

In the paleontological collection at Princeton University there is a fine, large shell of a
species of Echmatemys which was collected in 1895, by Mr. J. B. Hatcher, in the middle
Uinta formation, on White River, Utah. It bears the catalog number 11198. This shell is
practically complete and but little crusht. The total length, in a straight line, is 460 mm.;
the width, 295 mm.; the height above the bottom of the plastron, 160 mm. In outline the
carapace is somewhat concave in front, rounded behind. The hinder peripherals flare slightly
upward,

On the nuchal bone and the anterior neurals there is a slight ridge; and this reappears and
is more prominent on the hinder third of the shell.

The nuchal bone is 67 mm. long and 107 mm. wide. It is excavated behind for the first
neural. The neurals are relatively broad, the second, third, and fourth hexagonal; the fifth

octagonal, joining the fourth, fifth and

Dimensions of neurals. Dimensions of vertebral scutes. sixth costals; the sixth and seventh

: ey Paths broadly hexagonal; the eighth nearly

No. Length.| Width. | No. | Length. |. sae ata quadrate. The table shows the dimen-
: = 2 ee sions of the neurals.

The first suprapygal is 37 mm. long,

1 60 45 1 70 112 1 : 3 :

2 43 2 2 115 80 102 21 mm. wide in front, and 42 mm. wide

3 5° 42 | 3 oO eg ws posteriorly. The second is 47 mm. long

4 5° 430) 4 78 75 4 : :

: a4 47 ° 86 | 43 142 and 115 mm. wide.

6 30 42 The first peripheral has the free edges
aN i | perip ge

if so | moderately acute, but toward the axil-

me a | | lary notch the others become obtuse.
All these rise above the free margin about
60mm. The eighth peripheral is 67 mm. high. The pygal is 42 mm. wide and 38 mm. high.

The vertebral scutes are longer than wide with the sides nearly straight, except where the
sulci dividing the costal scutes are given off. The dimensions of these scutes are given above.

The anterior suprapygal is 37 mm. long, 21 mm. wide in front, and 41 mm. behind. The
second suprapygal is 49 mm. long, 105 mm. wide across the middle, 33 mm. where it joins the
pygal. The hinder boundary of the fifth vertebral scute lies on the second suprapygal.

The axillary and inguinal buttresses rise high within the carapace, but the details are not
known. They extend at their bases but a short distance inward beyond the free borders of
the plastron.

The anterior lobe of the plastron is 120 mm. long and 200 mm. wide at the base. From
the axilla the width decreases slowly to just beyond the hyoepiplastral suture, then more
rapidly by a sigmoid curve to the lip. The latter is 65 mm. wide and truncated. It projects
little beyond the ends of the gulo-humeral sulci. As seen from below, it is convex from side to
side; as seen from above, concave. The thickened portion of the lip continues backward
30 mm.; and behind it the thickness is not greatly reduced. The free border of this lobe 1s
acute. On the upper surface of the bone the horn-covered surface is 23 mm. wide.

The entoplastron is diamond-shaped, 70 mm. long and g5 mm. wide.

The hinder lobe is 150 mm. long and 200 mm. wide at the base. The notch in the hinder
end is 16 mm. deep and 55 mm. wide. The border of the lobe is acute. Seen from above, the
beveled surface is 37 mm. wide at the hypoxiphiplastral suture; at the femoro-anal sulcus
only 15mm. At the inner border of the bevel the thickness is 20 mm.

EMYDID&. 343

The epiplastrals occupy 44 mm. of the midline; the hyoplastrals, 125 mm.; the hypoplas-
trals, 120 mm.; the xiphiplastrals, 8 mm. At the junction of the hyoplastrals and hypoplas-
trals, at the midline, the thickness is 17 mm.

Measured on the midline the gulars are 57 mm. tong; the humerals, 40 mm.; the pectorals,
73 mm.; the abdominals, 115 mm.; the femorals, 70 mm.; the anals, 52 mm.; both the gulars
and the pectorals encroach on the entoplastron.

In many respects this species resembles E. wyomingensts of the Bridger beds. It is, how-
ever, improbable that the latter species continued on into the Uinta epoch. Furthermore,
differences are presented, notably in the greater width of most of the vertebral scutes.

Genus PALASOTHECA Cope.

Species small, with thick and solid bones. A dorsal keel present. Scutal sulci deeply
imprest. The epiplastral lip projecting and the inguinal buttress probably ascending above the
borders of the fifth and sixth costals.

Type: Paleotheca polycypha Cope.

This hardly definable genus was establisht by Cope to contain his species polycypha
and P. terrestris. These he afterwards referred to Emys. As there is neither evidence nor
probability that the species belong to Emys as now understood, the species must be removed
to some other genus. It 1s possible that they belong in Echmatemys, but of this there is little
evidence. They are very imperfectly known species; and as the genus Paleotheca has been
already establisht for them, it seems that no confusion or inconvenience will be produced in
retaining them there until more is ascertained regarding their structure and relationships.

Cope suspected that these small turtles might be the young of species already described
from adult remains, but he concluded that they had too many fercuies of maturity to be merely
young animals. Cope thought also that they showed relationships with the modern genera
T errape ne (Cistudo) and Te ides but there appears to be little probability of this.

Unfortunately the types of both the species here described are extremely fragmentary.

Paleotheca polycypha Cope.

Paleotheca polycypha, Corr, Palxont. Bull., No. 1, 1872, p. 463; Proc. Amer. Philos. Soc., x11, 1873
p- 463. -

Emys polycyphus, Core, Sixth Ann. Report U.S. Geol. Surv. Terrs., 1872 (1873), p. 625, 629.

Emys polycypha, Corr, Vert. Tert. Form. West, 1884, pp. 129, 131, plate xviii, figs. 20-

;
22,

The type of the present species is in the U. 5. National Museum and bears the catalog
number 4097. The species was based on very meager materials and only a portion of this was
figured. The remains were found in the Bridger beds, but the exact locality and level were not
communicated.

The following is Cope’s description:

This species of tortoise 1s indicated by vertebral, costal, and marginal bones of very small indi-
viduals. “hese bones are, however, not only thoroughly ossifed, but are very stout, indicating the adult
age of the animal. The deeply impressed scutal sutures, and heavy proportions, as well as the elevated

carina of the carapace, indicate affinity with Crstudo, or , perhaps, Testudo. As a generic character,
it may be noted that the vertebral bones are subqu: dente. and support the neural canal without
intervening lamina.

The carina of the carapace is abruptly interrupted at intervals; sometimes with, sometimes with-
out, a pair of pits, one on each side. The marginal bones are well secured and the scutal sutures are
deeply impressed on them.

Measurements.
Meter.
Length of vertebral bone. -. 0,009
Width of vertebral bone 0085
Length of marginal bone ol

This is the least of the tortoises of the Bridger formation.

‘The measurements given above of the neural (vertebral bone) apply to neither of those
feured by Cope. The original of his fig. 20 represents a neural 8 mm. long and 8 mm. wide.

344 FOSSIL TURTLES OF NORTH AMERICA.

The figure itself is incorrect. His fig. 21 is that of a bone 7 mm. long and 8 mm. wide. The
bones figured indicate a turtle which had a carapace about 100 mm. long. The originals of
Cope’s hgs. 20, 21, and 22 are in the U.S. National Museum. We are not informed by that
writer whether or not these bones belonged to a single individual. If they do, his fig. 21 repre-
sents the seventh neural and his figure 20 the eighth. Cope’s fig. 22 represents a peripheral.
In its upper border there is a pit for the end of a rib. The fore-and-aft extent of the bone is
gmm. Its free border is broken away, but the height of the bone was somewhat more than
1omm. It is considerably recurved. Its ebro is between 3 mm. and 4 mm. The sulci
crossing it are broad and rather deeply imprest.

Palzotheca terrestris Cope.

Paleotheca terrestris, Cope, Palewont. Bull. No. 1, 1872, p. 464; Proc. Amer. Philos. Soc., x11, 1873, p. 464.

Emys terrestris, Cope, Sixth Ann. Report U. S. Geol. Surv. Terrs., 1872 (1873), pp- 625,629; Vert. Tert.
Form. West, 1884, pp. 129, 130, 131, plate xviii, figs. 23-25.—Hay, Bibliog. and Cat. Foss. Vert.
N. A., 1902, p. 448.

Of Cope’s specimens of this species, three in number, those parts represented by his
figs. 23, 24, and 25 of the plate cited are in the U.S. National Museum and have the number
2107. All his materials were found in Bridger strata, but the exact locality and level are
nowhere mentioned. ‘They were undoubtedly secured somewhere in the region about Fort
Bridger, Wyoming.

Of his type specimen Cope figured 1 neural, 1 costal, and the right epiplastron. In his
description he probably intended to give the measurements of the aan figured. At any rate,
there is some error, for it is not probable that any neural was twice as wide as long. The neural
feured is g mm. long and 13 mm. wide. The width of the costal is given as 11 mm., whereas
the width of his figure 25 1s only a little more than 10 mm.

This species is stated by Cope to differ from P. polycypha in having bones at once larger
and thinner; and this is confirmed by a comparison of the neurals of fhe two species, as they
are figured. As in the case of P. polyc ypha, there was a dorsal carina, and this was interrupted
by the deeply imprest scutal sulci which crost it.

The epiplastron is 19.5 mm. long and 18 mm. wide. The lip projected abruptly from the
general outline about 3 mm. and was truncated. The anterior edge was acute. At its base the
lip was 21 mm. wide and nearly as wide in front, the width of the half of it present being 10 mm.
On the upper side of the lip the bone was thickened backward for a distance of about 11 mm.,
the greatest thickness being 4.5 mm.

Cope’s fig. 254 gives a view of the hinder articular border of a costal. This is 3 mm. thick
at the proximal end of the bone, but at the lower end is 5 mm. This costal appears to be the
fifth of the right side; and with the succeeding one formed a ridge for the inguinal buttress. As
shown by Cope’s fig. 25a, at the lower end of the bone and at its hinder border there was the
half of an excavation for this buttress. About the distal half of the costal is broken away and
the buttress therefore ascended one-half the height of the costal. The rib-head is hardly dis-
cernible. The proximal end of the costal does not join accurately the neural of Cope’ s fig. 233
hence it is concluded that this neural is the third. “The costo-vertebral sulcus (Cope’ s fig. 25)
crosses the costal at a distance of 5 mm. from the proximal end, from which fact it 1s concluded
that the fourth vertebral scute was about 28 mm. wide. The turtle was undoubtedly a small
one with a thick, heavy shell.

Cope states that the articulations of the bridge with the costals were not known to him.

No specimens belonging to this species or to P. polycypha were secured by the expedition
from the American Museum of Natural History into the Bridger beds 1n 1903.

Genus HYBEMYS Leidy.

Insufhiciently known emydoid turtles, the upper surface of whose peripherals was orna-
mented by a row of hemispherical bosses, each of which was crost by the suture between the
two peripherals on which it rested.

Type: Hybemys arenaria Leidy.

EMYDID.

Ww
—-
wr

Hybemys arenaria Leidy.

Hybemys arenartus, Letpy, Proc. Acad. Nat. Sci. Phila. 1871, p- 103; Fifth Ann. Report U.S. Geol.
Surv. Montana, etc., 1871, (1872), p. 369; Contrib. Ext. Vert. Fauna West. Terrs., 1873, p. 174,
plate xv, fig. 9.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448,

This species was based by Dr. Leidy on a single peripheral and a fragment of a costal of
an emydoid turtle believed to be about the size of Chrysemys picta or Clemmys guttata. These
bones were secured on Little Sandy Creek, Wyoming. The level is that known as horizon A
of the Bridger Eocene. The specimen belongs to the Academy of Natural Sciences, Phila-
delphia.

The bones are described as being unusually thick in proportion to the width. The sulci
are strongly markt. The rib-heads are stout. The outer portion of the upper surface of the
peripheral is strongly defined by the groove of the costo-marginal sulcus. At the anterior and
the posterior ends of the peripheral there is seen a semicircular boss. It is inferred that the
other peripherals had at each end a similar semicircular boss, so that around the carapace,
on the peripherals, there was a row of hemispherical elevations, each of which was crost by the
suture between the two peripherals on which it rested. :

Genus CHRYSEMYS Gray.

Shell smooth, deprest, without traces of dorsal keel. Carapace not serrated behind;
often dentated in front. Plastron with broad anterior and posterior lobes. The anterior lobe
with a distinct lip which is often dentated. Posterior lobe truncated behind, scarcely notcht.
Inguinal buttresses articulating with the fifth costals. Alveolar surfaces of the upper jaw
narrow in front, increasing in width backward, never very broad, and with a feeble longi-
tudinal ridge. Choanz on line joining the fronts of orbits. Alveolar surface of lower jaw with
a longitudinal groove bounded inwardly by a sharp ridge. Symphysis of lower jaw very short.

The type of this genus is Chrysemys picta, the painted turtle of the Atlantic states of the
Union. From the Alleghenies to the Mississippi River the genus is represented by C. cinerea.
West of the Mississippi river we find C. bell:; while in the lower region of that great stream is
found another species or race, C. dorsalis.

To the writer it appears that these species form a natural group worthy of generic rank,
and that C. trmida is an extinct member of that group.

Chrysemys timida sp. nov.
Plate 46, fig. 2; text-fig. 449.

Chrysemys timida is founded on a shell which belongs to the E. & M. Museum of Princeton
University, and has the catalog number 10853. It was collected by the University expedition,
in the Equus beds of Sheridan County, Nebraska, not far from the Niobrara River. Doubtless,
as it lay in the matrix it was complete; but from the vicissitudes of collecting, transporting
and preparing, it has suffered somewhat. The matrix is sand that scarcely coheres and the
bone itself is friable. In its present condition most of the peripherals of the left side are gone
and considerable portions of those of the right side. The other parts of the carapace are in

good condition and display well the bone
Dimensions of neurals. Dimensions of vertebrals. sutures and the sulci. Portions of the

Midi tele even tat plastron have crumbled away, but the
Vic 1 gsrcates z)

No. | Length.) ‘Width. | No. | Length. |. tront.| width, | structure can be pretty satisfactorily

= === — determined.

1 16 lo 1 30 45 45 The individuals of this species reacht

2 14 12 2 28 26 46 a considerable size, compared with those

2 ‘ 2 2 2 8 —es : a ;

A o a e = - a now living, being about equal to C. bellr.
= 5* aa mp a

5 13 13 ; 27 20 42 The extreme length of the carapace

6 a de (plate 46, fig. 2; text-fig. 449) was perhaps

of 10 Ss 2 = =

8 oh 6 a little more than 160 mm.; the breadth,

a bY

about 120 mm. The shell was evidently

340 FOSSIL TURTLES OF NORTH AMERICA.

considerably deprest, but probably less so than its present height, 40 mm., indicates. We
can not determine to what extent, if any, the hinder border of the carapace was notcht. ‘The
hinder peripherals are slightly recurved. Their free margins are acute. No carina is pres-
ent, but on the nuchal and the first neural there is a perceptible
elevation. In the region of the hinder neurals there is a decided
longitudinal depression. The surface is smooth, except that on
x the outer ends of the costals there are longitudinal ridges and
sof Gy nad grooves, due to the growth of the epidermal scutes.
jek od The neural bones are rather narrow in comparison with those
of C. picta. Most of them are hexagonal, with the broader end
forward. ‘The dimensions of the neurals are shown in the table
on page 345.
The nuchal had a median length of more than 30 mm., a mar-
| ginal width of about 20 mm., and an extreme width of 35 mm.
} (. The suprapygal plates are three in number. The first has a length
— of 5.5 mm. and a width of 10 mm. The second is bifurcate,
like the same bone in Testudo, the hinder border being deeply
concave. ‘The median length is 7 mm., the extreme width, 21 mm.
The third is nearly diamond-shaped, fitting in between the second
suprapygal and the pygal. It is 8 mm. long and 15 mm. wide.

ce oil ae 4 The pygal is 22mm. wide, 17mm. long and 4.5 mm. thick.
aw oe The first peripheral is 20 mm. fore and aft and the same
PD UAA YL along the free margin. The eleventh is 18 mm. high and 17 mm.
ate Nea along the free margin.

— . .

; : eer The plastron is somewhat damaged. It is 157 mm. long.

Fic. 449.—Chrysemys timida. . 2 = : =
= M4 The anterior lobe is 43 mm. long and 72 mm. wide at the base.

Carapace. X 3. eas icgutcs ;
The lip is truncated and appears to have been 40 mm. wide.

The hinder lobe is 55 mm. long and 84 mm. wide at the base. A broad notch occupied the
hinder end. The inguinal hares is attacht to the fifth costal plate.

The entoplastron is 25 mm. long and 27 mm. wide. The hypoxiphiplastral suture appears
to have run nearly straight across the hinder plastral lobe.

The hyoplastrals occupy about 36 mm. of the midline; the hypoplastrals, about 48 mm.;
the xiphiplastrals, about 37 mm.

The vertebral scutes are rather broad and are strongly bracket-shaped laterally. Their
dimensions are given in tabular form on the preceding page.

The inferior surface of the plastron is injured so that few of the sulci can be traced. The
abdomino-femoral passes between the inguinal notches with a slight convexity forward. The
femoro-anal sulcus is directed outward and backward. The femoral scutes are about 18 mm.
long on the midline; the anals, about 30 mm.

Genus DEIROCHELYS Agassiz.

Differs from Chrysemys in having the heads of the ribs long and thread-like, and the shell
sculptured.
Type: Detrochelys reticulata (Daudin).

The following species is referred provisionally to Deirochelys.

S

Deirochelys floridana sp. nov.
Plate 54, figs. 1, 2; text-fig. 450.

The nuchal bone on which the present species 1s based is a part of the Jarman collection,
the property of the Vanderbilt University, Nashville, Tennessee. The collection was obtained
in Hillsboro County, Florida, and the deposits probably belong to the Peace Creek beds.
While the generic position of the species is not assured, the form 6k the bone and especially 1 its
sculpture so much resemble that of Dezrochelys reticulata that it is referred to the latter inter-
esting genus.

EMYDID. 347

The nuchal bone here described has a median length of 70 mm. ‘The anterior border has
a width of 37 mm. The extent between the lateral angles is 77 mm. The hinder border
measures 17 mm. The anterior border is acute. From this the bone thickens backward on
the under side for a distance of 40 mm. Here the thickness is 20 mm. On the midline the
greatest thickness is 17 mm. The excavation for the first neural is narrow and the bone is here
€ mm. thick.

The nuchal scute is 32 mm. long, 5 mm. wide in front, 17 mm. wide behind. The fore-
and-aft extent of the first marginals is 44 mm. The front of the first vertebral scute is 51 mm.
wide. Backward it narrows slightly, then again expands. It extends backward on the bone
a distance of 38 mm. ‘The lateral angles are occupied by portions of the first costal scutes.

The sculpture consists of more or fess continuous ridges of quite uniform height, separated
by sharp grooves. Usually there are 5 or 6 of these ridges i in a line 10 mm. long. On the
nuchal scute area these ridges are parallel with the riidline, On the area of the first marginal
they run outward and forward, making an angle of about 25° with the midline. On the area
covered by the first vertebral scute the ridges are nearly parallel with the midline, those along
the lateral borders of the scute diverging somewhat. The ridges of the areas of the costal
scutes are the most prominent, and they make an angle of about 45 degrees with the midline.

Specifically this species is very different from D. réticulaia. In the latter the first vertebral
scute excludes wholly the costal scutes from the nuchal bone. This bone ts far thinner than in
» floridana.

No other bones in the collection can be referred with certainty to this species. In the
collection there is the front two-thirds of the right first costal plate of a turtle that is provision-
ally placed here (plate 54, fig. 2; text-hg.
x '\ re 450). It fits quite accurately against the
\ : ia a postero-lateral border of the type bone and
\. \ “agrees with it in sculpture and thickness.

Furthermore, the costo-vertebral sulcus coin-
cides with that of the nuchal. The distal
end of the bone is thickened and on the inner
surface excavated for the axillary buttress.

A peripheral, the right second, may
belong to this species. Fig. 450 represents
the type nuchal, the first costal mentioned
above, and this peripheral, placed in their
proper positions with reference to one
another. The height of the peripheral i is
Fic. 450.—Detrochelys floridana. Nuchal, first and only 34 igeboues but when we examine the

second peripherals, and part of first costal. ><}, Same bone in D. reticulata we find that it too

Partly restored. is reduced in the line from the free border

: to the upper border. This is a result of the
narrowing of the carapace. The first costal scute descends on the bone a distance of 26 mm.
The sculpture on its area is directed downward. On the area of the second marginal scute
the ridges run at nearly right angles with the free border. On the area of the succeeding
scute they are directed dew aor and strongly backward.

In the Jarman collection is the portion of a left xiphiplastron extending backward from
the femoro-anal sulcus. The lower surface is ridged and grooved like the type nuchal, the
ridges being directed parallel with the midline. ae hinder border of the plastron was slightly
notcht, as in D. reticulata. At the midline the bone is from 5 mm. to 7 mm. thick. The
plastron had a length of about 290 mm. The bone greatly resembles the corresponding part
of D. reticulata.

'

Genus TRACHEMYS Agassiz.

Shell varying from deprest to rather elevated. Usually at least traces of a dorsal keel.
Neural plates hexagonal, with broad end in front. Carapace sometimes smooth, but more
usually with priktes and grooves; occasionally elaborately sculptured. Hinder border of
carapace usually more or fess serrated. Plastron with a distinct lip in front and a shallow

348 FOSSIL TURTLES OF NORTH AMERICA.

emargination behind. Alveolar surfaces of upper jaw each with a longitudinal ridge, which
Is soewhar denticulated and higher behind than in front. Choanz nearly as far pack asa
line joining the middles of the. orbits. Alveolar surface of the lower jaw with a longi-
tudinal groove, which is separated from a shallower groove by a longitudinal ridge. Symphysis
of lower jaw short, equal to about half of the distance between the quadrates.

As type of this genus may be taken 7. scripta, the species longest and best known and
incidentally the one mentioned first by Agassiz under the name.

The species of this genus are allied to the species of Chrysemys, but they attain a larger
size, possess a more vigorous organization, and a fiercer disposition. The wrinkled and
furrowed carapace, notcht posteriorly, distinguishes the species from those of Chrysemys.
The plastron has a quite distinct lip, and this is occasionally shghtly dentated, but not so
conspicuously as in Chrysemys

The following analysis may rt in determining species of which the nuchal bone is present:

1. All the bones thin and little sculptured ... 3 oe hilli
2. Nuchal thick, strongly sculptured; free border broader than in 7. sculpta, with notch

for eure broader.........-.00--eeeeeeeee : euglypha
3. Nuchal not so thick as in eug/ypha, about 15 mm.; free border rather obtuse See scul pta
4. Notch for first neural extremely broad ............. -. -. Jarmant
5. Nuchal moderately thick, 10 mm.; width in front half the* maximum “width ae petrolet
6. Nuchal bone moderately thick; width in front three-fifths the maximum ........ _.. btsornata
7. Epiplastral lip spout-like ..... sch ass NOLO «Sd ce trulla

Trachemys hilli (Cope).
Plate 55, figs. 1, 2; text-figs. 451, 452.

Pseudemys hillit, Core, Bull. Geol. and Geog. Surv. Terrs., tv, 1878, p. 395-
Trachemys hillit, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 449.

At the present time this species is represented by only the type specimen. This is in the
American Museum, as a part of the Cope collection of reptiles, and has catalog number 2425.
It was collected for Professor Cope in 1877, by Mr. R. S. Hill, in Decatur County, Kansas,
from Loup Fork deposits. It came, therefore, from the same locality and the same level as the
specimens of Testudo orthopygia. Since its arrival at the American Museum the fragments of
which the specimen was composed have been articulated under the supervision of the writer;
and the present appearance of the specimen is shown on plate 55. The shell has retained the
plastron complete, except that the entoplastron and the epiplastra are missing. Of the carapace
(plate 55, fig. 1; text-fhg. 451) the peripherals are present from the rear to the fourth inclusive
on the right side and to the fifth inclusive on the left side. The third left peripheral also is
present. The nuchal is wanting. Only 3 complete neurals have been preserved, the fourth,
the fifth, and the seventh. A portion of the third is at hand. On the right side we have the
first, second, and fourth costals, and the proximal end of the third. On the left side there are
present the third, the fifth, and sixth costals, with a portion of the eighth. Both suprapygals
are wanting.

The whole length of the shell was very close to 200 mm. The width at the hyohypoplastral
suture is 138 mm. The width of a specimen of 7. rugosa, from some of the West Indian
islands, whose length of carapace is 192 mm., is 147 mm. It will be seen therefore that the
Loup Fork species is relatively more elongate.

In elevation of shell this species resembles 7. elegans or T. rugosa, rather than T. seripta,
the carapace being rather deprest. The maximum height from the bottom of the shell is
75 mm.

The fourth neural has a length of 17 mm. and a maximum width equal to the length.
The fifth neural is 18 mm. long and 16.5 mm. wide. The sixth neural had a length of 15 mm.
and a maximum width of 16 mm. The second pygal was 27 mm. wide.

Over the bridges a sharp keel intervened between the upper and the lower portions of the
shell. The free border of the third peripheral is acute. The posterior peripherals are only
slightly flared upward. Their free borders are thin and brought down to an acute edge. The

EMYDID&. 349

height of the eleventh is 29 mm.,; its width along the free border, 22 mm. ‘The pygal has a

height (antero-posterior dimension) of 23 mm. and a width of 21 mm. It has a deep median

notch; and there is a similar notch on each side of it. The interperipheral notches are not

deep, and there are no notches where the sulci cross the borders

; of the peripherals. In the latter respect this species differs from
Vertebral 5 .

Length Width. ie elegans.

scute.
: The bones of the carapace are thin, the border of the median
as costals being but little more than 2 mm. thick.
: = a The sulci are rather deeply imprest on the carapace. The form
3 35 47 and dimensions of the various scutes may be readily determined
F i is from fig. 451. The table herewith gives the dimensions of the

vertebrals.
The arrangement and forms of the scutes closely resemble
those of the specimen of 7. rugosa already mentioned.
The sulci separating the costal from the marginal scutes are arranged somewhat differently
in this species from the arrangement in T. rugosa and T. scripta. In T. rugosa the costo-mar-

we iay t aa
a, ra ‘

\
F |
|
|
4 ee
\
451. 452.
{
aes |} Y
* f /

eee ee eee
Fics. 451 AND 452.—Trachemys hill. Carapace and plastron of type. 4.
451. Carapace. Front restored. 452. Plastron. Anterior lobe partly restored.

ginal sulci run along on the peripherals at a considerable distance below the costo-peripheral
sutures from the nuchal to the eleventh peripheral. Here the sulcus rises somewhat and
crosses the midline on the hinder border of the suprapygal. In T. scripta the arrangement is
the same to the eleventh peripheral, where it remains low down and crosses the upper third
of the pygal. In T. hilli from the front of the bridge the sulci appear to coincide closely with
the sutures until the seventh peripheral is reacht. Here the sulci descend on the peripherals,
but not far, and they cross the midline on the upper part of the pygal.

In the case of the neurals preserved there are some longitudinal wrinkles on the hinder
ends of the third and the fifth, just behind the sulci crossing these bones. On the costals is a

350 FOSSIL TURTLES OF NORTH AMERICA.

number of longitudinal grooves, which mark the growth of the scutes. The deepest ones are
from 5 to 7 mm. apart and appear to indicate the yearly increase in size. On each peripheral
behind the bridge we find in front of the sulcus crossing it some strong grooves parallel with
the free border of the shell; behind the sulcus, some more delicate grooves more nearly parallel
with the axis of the shell.

The length of the plastron (plate 55, fig. 2; text-fhg. 452), from the outer anterior angle of
the epiplastron to the extremity of the xiphiplastron, is 165 mm. In the midline, from the
hinder border of the entoplastron to the notch in the rear, the length is 142 mm. The width of
the anterior lobe at the base is gi mm. The entoplastron had a width of 33 mm.

The bridge has a width of 69 mm. It rises rapidly from the bottom of the plastron.

The Give: plastral lobe has a length of 75 mm. and a width of go mm. at the base. Near
the suture between the hypoplastra and the xiphiplastra the width is g6 mm. At the end of the
femoro-anal sulcus there is only a slight notch. The free margins of the plastral lobes, so far
as preserved, are acute. The extremities of the xiphiplastral bones are rounded and slightly
dentated.

The humero-pectoral sulcus crosses the plastron behind the entoplastron. The pectoral
scutes have a width at the midline of 27 mm.; the abdominals, a width of 22 mm.; the anals,
a width of 4omm. There are large axillary and inguinal scutes.

The lower surface of the plastron i is delicately p grooved longitudinally.

Professor Cope mentions the presence of portions of the seul: but there is little more than
the left quadrate. It presents no difference when compared with that of 7. rugosa.

The shoulder-girdle and the limb bones appear to resemble essentially those of the living
species just mentioned.

Trachemys euglypha (Leidy).
Plate 54, fig. 3.

ee euglypha, Lerpy, Proc. Acad. Nat. Sci. Phila. 1889, p. 97; Trans. Wagner Free Instit., 1, 1889,
. 27, plate iv, fig. 1.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 447.

The present species was based on a single bone, the nuchal, of a turtle found in the Peace
Creek beds, Florida. Dr. W. H. Dall, of the U.S. Geological Survey, has examined these
deposits and pronounct that bed, about 2 feet in thickness, from which vertebrate remains
have been obtained, to be of older Phocene age. However, since from that bed Dr. Leidy has
described vertebrates belonging to various epochs, from the Miocene to the present, the correct-
ness of the determination is in question. The type of the species here described belongs to
the Wagner Free Institute, Philadelphia, but the writer has not been able to find it there.

Dr. a eidy has referred his species to the genus Emys; but it can not belong there—as that
genus 1s understood at present. The nuchal Fecorbles ‘closely that of a specimen of Trachemys
seripta now in the American Museum of Natural History. From this, however, it differs
specifically. The length of the bone at the midline is 58 mm. The total length of the carapace
of the specimen of 7. scripta just mentioned, the length of whose nuchal is 50 mm., is 210 mm.
We may therefore conclude that the carapace of Dr. Leidy’s type had a length of about
290 mm. The width of the front of the nuchal is 37 mm., the greatest width 73 mm. This
border is deeply notcht, but the bottom of the notch is divided by. the projection into it of the
area occupied by the nuchal scute, which is 11 mm. wide. T he thicknesseof the bone at the
articulation with the first peripheral is 21 mm.; at the articulation with the first neural, 6 mm.
The nuchal of the specimen of 7. scr:pta mentioned has a maximum thickness of only 10 mm.
a fact showing that 7. ewglypha had a shell much thicker and heavier than that of the living
species. The width of the border which articulated with the first neural is 23.5 mm.

The scutal sulci are deeply imprest. The nuchal scute has a length of 20 mm. and a width
of 10 mm., its lateral borders being parallel. That part of the first vertebral scute which lies
on the nuchal bone is 38 mm. long: Measured anteriorly between the points where the lateral
sulci of the vertebral ] join the costo-marginal scutes, the width of the first vertebral is 34 mm.
Measured posteriorly, where the intemal sulci pass on to the first costals, the width is 50 mm.

The upper surface of this bone is strongly sculptured, resembling somewhat that of 7.
scripta, but ridged and grooved more boldly.

EMYDID&. 35!

The wniter has received for examination from the Wagner Free Institute an injured nuchal
bone (plate 54, fig. 3) that was collected at Peace Creek, Florida. It has some resemblance to
that of 7. euglypha. The sculpture is not so strong and that produced by the growth of the
horny scutes shows in addition to that seen in the type of the species. On the area of the first
vertebral scute, in the midline, there is a high ridge, or carina.

Trachemys sculpta sp. nov.
Plate 54, figs. 4-9.

In the Dr. Jarman collection of fossil bones made in Hillsboro County, Florida, now the
property of Vanderbilt University, there 1s a strongly sculptured nuchal bone which represents
probably a hitherto undescribed species. This nuchal resembles much that of 7. brsornata
(Cope) and possibly belongs to it; but the differences in form and sculpture and apparently
the differences of level seem to justify regarding it as distinct. Cope’s bisornata came from the
Equus beds, belonging to the Pleistocene; the present species from probably the Peace Creek
beds, belonging to ae Pliocene.

The nuchal (plate 54, fig. 4) has a median length of 55 mm.; a width of 29 mm. in front;
and a maximum width of 63 mm. The length and breadth are relatively the same as in T.
bisornata. The width in front is only 50 per cent. of the length, while in 7. brsornata it is
7o percent. The anterior edge is obtuse; in the Texas species it is acute. The greatest
thickness, just behind the sulcus between the nuchal and vertebral scutes, is 15 mm.; oat at
the articulation with the first peripheral, 13 mm. Where the bone joins the first neural the
thickness is 7mm. The area of the first vertebral scute 1s very convex, producing a broad
rounded carina.

The sulci are sunken to a great depth. The nuchal scute is long and narrow, and its area
is raised into a strong ridge. The first vertebral 1s 24 mm. wide in front and it expands poste-
riorly. The front of each first marginal on this bone is nearly one-half the width of the front of

the first vertebral. In T. biscknata it is not one-third. The areas of the first marginals are
sculptured into prominent ridges and grooves. In T. bisornata these are feeble ant the lines
of growth of the scutes are more prominent. Where the ridges show in bisornata they diverge
at a greater angle from the midline. On the area occupied by the first vertebral of 7. sculpta
there are some ridges running parallel with the midline. On the area occupied by each first
marginal there are § or 6 ridges which run outward and backward.

Plate 54, fig. 5, represents the distal end of probably the third costal. Its width is 45 mm.
at the distal border, but it narrows upward. The fragment belongs to the Jarman collection,
in Vanderbilt University.

Plate 54, hgs. 6, 7, represents two neural bones found with others of the same kind in the
Jarman collection. The one with the sulcus crossing it has a length of 35 mm. and a thickness
where it joined the costal of 15 mm. They may or may not belong to the species here described.

Figs. 8 and g of plate 54 represent two costals which may belong to the present species.
Fig. 8 is probably the right fourth costal and lacks the proximal half. The thickness at the
distal endis8 mm. The original of fig. g is the left sixth costal. It is thickened on the anterior
border of the distal end to 13 mm., the posterior border at the distal end being only g mm.

The type nuchal resembles rather closely T. ewglypha (Leidy); but the front of the nuchal
of the latter is broader and more deeply notcht and the excavation for the first neural is broader.
The nuchal scute is broader and shorter. The greatest thickness is 21 mm., far exceeding that
of T. scul pta.

Trachemys? jarmani sp. nov.

Plate 54, figs. 10-12.

The species to which the above name is given is based on a complete nuchal bone, a part
of the Jarman collection of fossil bones obtained in Hillsboro County, Florida, by Dr. W. H.
Jarman, and presented by him to Vanderbilt University, Nashville, Tennessee. The age of
the beds is somewhat uncertain, but they are probably of the same age as the Peace Creek
beds. ‘The species is referred provisionally to Trachemys

The nuchal (plate 54, fig. 10) is remarkable on account of the shortness of its hinder
portion and the evidence w hich it affords that the neural bones were very broad. The total

352 FOSSIL TURTLES OF NORTH AMERICA.

length of the bone is 61 mm. ‘The front border is excavated slightly; the hinder border widely,
for the reception of the first neural. The length along the midline is 47 mm. The width of the
anterior border is 37 mm.; the greatest width, 80 mm. The anterior border is acute. From
this the bone thickens backward on the under side a distance of 47 mm., where, at the mid-
line, it is 20 mm., at the border for first peripheral, 25 mm.; then it thins rapidly to the hinder
border, where it is 13 mm. at the midline, Io mm. at the sides of the notch for first neural.

In this species the front of the first neural is on a line with the lateral angles of the bone,
an unusually forward position. The neural must have been of uncommon width, not less than
50 mm., occupying thus five-eighths of the width of the nuchal. This first neural must, too,
have been 13 mm. thick in front.

The nuchal scute is 34 mm. long, 6 mm. wide in front, 12 mm. wide posteriorly. On the
inner side of the bone it extended backward 21 mm. The first marginal had an extreme fore-
and-aft extent of 4o mm. The front of the first vertebral scute is 41 mm. wide. It extended
forward on the nuchal only 13 mm. at the midline. The lateral angles of the bone are occupied
by portions of the first costal scutes.

The upper surface of the bone is beautifully sculptured with grooves and sharp, inter-
rupted ridges. On the nuchal scute area the ridges run parallel with the midline. On the
areas of the first marginal scutes the ridges are short and suddenly interrupted at their anterior
ends. They run forward and outward, making an angle of about 25° with the midline. The
ridges on the front of the first vertebral scute area are short, almost tubercular, and are parallel
with the midline. On the areas of the first costal scutes the ridges are coarser and they run
outward and backward, making an angle of 64° with the midline.

No other parts are known that can be referred with certainty to this species. No neurals
in the collection are broad enough to belong to it. A peripheral (plate 54, fig. Ir), the right
eighth, appears to be worthy of reference here on account of its sculpture and thickness. It
has a height of 50 mm., a width of 39 mm. below, and of 33 mm. above. The free border is
acute. From this the bone thickens rapidly, so that near the middle of the height it is 26 mm.
where it joined the sixth peripheral; 19 mm. where it articulated with the ninth. On the inside
of the bone, at the upper posterior angle, is a pit for the end of a rib, probably the sixth. On
the articular face for union with the fifth peripheral there is a striated depression, which appears
to have been a part of a pit between the two peripherals for a rib, the fifth. On the same face,
nearer the inner surface of the bone, is a rounded smooth depression which indicates that the
sternal chamber reacht this face. Still nearer the inner surface of the bone is an excavation
apparently for a part of the inguinal buttress.

The sculpture of this bone resembles that of the nuchal of Desrochelys floridana. How-
ever, the thickness appears to be too great for the latter species.

A left third costal in the collection is referred provisionally to this species (plate 54, fig.
12). It presents the proximal end. The width, just outside the costo-vertebral sulcus, is 38
mm. It belonged to an individual with a carapace about 340 mm. long. The most conspicuous
character is the great thickness at the suture with the neurals, this being 20 mm. The thick-
ness diminishes to the costo-vertebral sulcus where it is g mm. The thickening has produced
a broad keel along the back. The sculpture agrees well with that of the type nuchal bone.

Trachemys petrolei (Leidy).

Plate 46, figs. 3, 4

Emys petrolei, Lewy, Proc. Acad. Nat. Sci. Phila. 1868, p. 176; Contrib. Ext. Vert. Fauna West. Terrs.,
1873, pp. 260, 340, plate ix, fig. 7—CoPE, Ext. Bat., Rept., and Aves N. A., 1869, p. 128.—Hay,

Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448.

Dr. Joseph Leidy states in his original description of this species that the types had been
submitted to him for examination by Messrs. George N. Lawrence and D. G. Elhot, of New
York, and that they had been previously presented to the New York Lyceum of Natural
History by Mr. Robertson. ‘The specimens were reported to have been obtained from blue
clay and sand beneath a bed of bitumen, in Hardin County, Texas. The age is Pleistocene.
These bones and most of those accompanying them are impregnated with bitumen. They
now belong to the American Museum of Natural History and have the catalog number 3933.

EMYDID&. 353

The type of the species Emys petroler Leidy must be regarded as being the two epiplastrals
figured by him in 1873. Leidy mentions and briefly describesia ‘nuchal bone and a hypo-
plastral, but there is no certainty that these belonged to a member of the same species. The
two epiplastrals are the right and the left, but they did not belong to the same individual.
Dr. Leidy’s figures present a view of the lower surfaces; the figures here presented (plate 46,
fig. 3) represent the upper surfaces.

The individuals to which these epiplastrals belonged appear to have had plastra about
200 mm. long, tho perhaps somewhat less. Dr. Leidy thought that the animal belonged
to the genus “Trachemys and compared it especially with T. scripta (I. scabra). W hen
compared with a specimen of the latter whose plastron is 270 mm. long da appear decided
differences.

The epiplastral lip of 7. petroler was 52 mm. wide; that of the specimen of 7. scripta
referred to is 60 mm. wide, a difference due to difference of size of the individuals. The lip of
T. petrolet is directed forward; that of T. scripta is rolled downward in front. The thickness
of the epiplastrals of 7. petroler at the symphysis is 11.5 mm., somewhat more than that of the
specimen of 7. scripta, altho the latter is so much larger. The backward extension of the lip,
along the midline on the upper surface, is 29 mm. in 7. petroler; in T. scripta, only 23 mm.
In the former the thickening referred to ends posteriorly much more abruptly than it Hoes in
T. scripta. In both species it may be observed that the gular scutes overlapt the anterior ends
of the entoplastron. There can be no doubt that 7. petroler is a species distinct from both T.
scripta and T. elegans. The latter species occupies at present the region where 7. petrole:
was found. T. ele -gans has a very different epiplastral lip, this being den concave above
so as to resemble a spout; and not so thick. In both 7. scripta and T. elegans the gular sulci
on the upper surface of the epiplastrals run outward and forward, while in T. petr lei they run
directly forward.

It will be observed from the figures that there are some differences between the two epi-
plastra, but these are not sufficient to indicate distinct species.

The nuchal bone (plate 46, fig. 4) mentioned by Dr. Leidy has a length of 46 mm. and a
maximum breadth of 50 mm. The width at the free border has been 25mm. The border for
articulation with the first peripheral is very concave. Where the sulci bounding the nuchal
scute crost the free border there are very deep notches, so that the nuchal scute projects as a
prominent tooth. The greatest thickness of the nuchal bone is 10 mm.

The nuchal scute is 20 mm. long and 7 mm. wide at the base. The width of the scute on
the under side of the bone is slightly be In T. scripta the scute is nearly twice as wide on
the lower side as on the upper. In J. elegans the lower side is about one-half wider than the
upper. The first vertebral scute of J. petroler has a width anteriorly of 27 mm., and it has
grown wider posteriorly. In the specimen of J. scr:pta mentioned, the first vertebral is only
18 mm. wide anteriorly. In the midline of the fossil nuchal there is a mere suggestion of the
presence of a carina; in 7. scripta the carina is very distinct. As to the sculpture, there are
faint ridges which occupy the same positions as the much more distinct ones in T. scripta and
Te: desans:

The hypoplastral bone mentioned by Dr. Leidy is present, as well as a second belonging
to another individual. These are much thicker than the corresponding bones of 7. elegans
and somewhat thicker than those of T. scripta. Here again we are uncertain whether these
bones belong to the same species as the epiplastra.

The nuchal bone above described resembles that of the species described by Cope under
the name Pseudemys bisornatus, here called Trachemys bisornata. We must therefore consider
the possibility that Cope’s species is identical with that described earlier by Leidy. This
question can not be settled until additional materials have been collected at one or both of the
localities, Hardin County and Atascosa County.

Trachemys bisornata (Cope).
Plate 56, fig. 1.

Pseudemys bisornatus, Cope, Proc. Amer. Philos. Soc., xvi, 1878, p. 228.
Trachemys btsornata, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 449.

23

4 FOSSIL TURTLES OF NORTH AMERICA.

oS)
wr

This species is stated to be based on portions of 3 individuals, which were collected for
Professor Cope by Mr. G. W. Marnock, in southwestern Texas. The beds are stated to
belong to the Pliocene; but now they are regarded as Pleistocene.

In the collection of the Philadelphia Academy there 1s found a part of the anterior half of
a carapace which evidently belongs to this species i and which is probably one of the three por-
tions referred to by Cope in his description. It is labeled in Cope’ s handwriting, and is stated
to have been collected by G .W. Marnock, from the Pliocene beds of Atascosa County, Texas.
Terr ‘a pene marnoc hit was described by Cope on the page following the description of the present
species and was said to come from the same formation. Rion the American Naturalist,
vol. x11, 1889, page 161, we learn that the latter-named species was found in the Equus beds.
From these Equus beds we have therefore T estudo atascose Hay, Terrapene marnochi (Cope),
Trachemys bisornata (Cope) ) and T. trulla Hay.

The specimen (plate 56, fig.1) in the Philadelphia Academy consists of the nuchal, the first
right peripheral, the first and second right costals, parts of the third and fourth right costals,
the first, second, fourth, and fifth peer! and the proximal portions of the first a second
left costals. The third neural is missing, but its dimensions and form are easily determined.

The nuchal resembles that of 7. scripta. In front it is thin-edged and sharp. It is slightly
notcht at the ends of the sulci bounding the nuchal scute, and between the ends of these sulci
are 3 teeth. Its length along the madline 4 is 4g mm.; its width anteriorly, 34 mm.; the max-
imum width, 55 mm. ‘The table herewith gives the dimensions of the neurals represented.

The thickness of the fourth neural is 7.5 mm. The first is
oval. The second is broadest in front ae deeply excavated to
receive the frst. The other neurals are hexagonal, with the broad
end in front.

Neural. Length. Width.

: oe ah The second costal is 26 mm. wide near its neural; the third
3 25 23 is 28 mm. wide; the fourth, 23 mm. They are rather thick proxi-
4 21 24 mally, as is indicated by the thickness of the fourth neural.

5 22 22

The nuchal scute is 19 mm. long and 10 mm. wide posteriorly.
The first vertebral is 46 mm. long, 33 mm. wide in front, 40 mm.
behind. The second is 52 mm. long and 50 mm. wide. The third is 43 mm. long, 54 mm.
wide. The sulci are deeply imprest.

Along the midline there appears a broad and shallow groove, beginning with the first
neural, showing most conspicuously on the second, and persisting on the fourth and fifth.
There is only a suggestion of a median carina.

The ornamentation of the carapace has been described by Cope, and his description
applies to the specimen here considered. The whole surface of the carapace, as far as known,
is sculptured into ridges and grooves. The areas occupied by the vertebral scutes are smoothest,
but here too we find some sculpture, On those costal bones which are traverst by the inter-
costal sulci we find that the area in front of the sulcus presents sharp ridges, some of which
run at right angles with the sulcus, while others cross these parallel with the sulcus. Behind
the Sulets the ridges run only at right angles with the sulcus, and these ridges are broader than
those in front of the sulcus. Those euerile which are not traverst by the intercostal sulci are
ornamented more like the anterior portion of the costal plates first described. The ornamenta-
tion may be otherwise described as follows: Along the front of each scutal area there is a band
of broad ridges. Most of the remainder of the area is occupied by ridges and grooves running
parallel with the length of the animal and crost by a system of less conspicuous ridges. The
lower border of the costal scutal area, that formed by the upper borders of the peripheral bones,
is occupied by coarse ridges at right angles with the length of the animal.

The sculpture of the « carapace of this tortoise has been compared by Cope to that found on
T. elegans. It appears to be still more like that of a large specimen of 7. scripta now in the
American Museum of Natural History. It can hardly ‘be doubted that the fossil species 1S
closely related to, perhaps the immediate ancestor of, both T. ele gans and T. scripta. It has
differed from T. ele gans in having a considerably thicker and more boldly sculptured carapace;
from T. scripta apparently i in having a less well-defined dorsal carina. Remarks on the pos-
sible identity of this species with ve mys petroler will be found on page 353.

EMYDID£.

Ww
wm
WN

Trachemys trulla sp. nov.
Plate 56, figs. 2-6; text-fig. 453

The type of this species is No. 3934 of the American Museum of Natural History. It con-
sists of portions of both epiplastra of a specimen which accompanied the type of Dr. Leidy’s
Emys (Trachemys) petroler; and was therefore obtained from the Pleistocene deposits of
Hardin County, Texas. Without additional materials it is not possible to determine with
exactitude the generic relations of the species, but the parts resemble most those of Trachemys
elegans, a present inhabitant of that region of the country.

The bones forming the type are Albee exactly the size of those of a specimen of 7. elegans
whose length of carapace is 240 mm. From the latter it differs in having a much narrower lip,
that of 7. elegans being 59 mm. wide, that of 7. trulla, 41 mm. wide. The lip of the latter
(plate 56, figs. 2, 3) is also of a somewhat different form. In 7. elegans, seen from aboye, the
gulo-humeral sulci are directed outward and forward to the border of the epiplastral bones,
the lip projects rather abruptly, and it is subtruncated. In 7. trulla each gulo-humeral sulcus,

= on the upper surface of the bone, runs directly forward, the lip
{ 4 es projects gradually from the border of the bone, and rounds for-
ward di inward to the midline. The free border of the lip of

< T. elegans is usually, if not always, dentated; that of 7. trulla is
yy j all) )
Da smooth in outline.
vA ft The lips of both 7. elegans and of T. trulla are excavated on

3 the upper surface so as to resemble somewhat the spout of a

t pitcher. In 7. trulla the sides of this spout descend more
i _ abruptly than in the case of the observed specimen of 7. elegans.
=e These sides rise each as a ridge some distance above the level of

; ————--— the gulo-humeral sulcus and parallel with it. Anteriorly each ridge

i descends into the free border of the lip. At the hinder end of each
{ ridge, at a lower level, is a deep pit.

At the midline on the upper surface the gular scutes extend
backward a distance of 15 mm. At the hinder end of the epi-
plastron the width of the humerals was about 15 mm.

Seen from below, the middle of the lip descends little below
the general level of the epiplastral bones. The gulo-humeral sulci
are deeply imprest and they extended backward on the entoplas-
tron. The length of the sulcus separating the gulars was 32 mm.
The suture between the two epiplastrals has a length of 27 mm.
The thickness of the bones at the symphysis is 7mm. The free
border of the epiplastron, where it joins the hyoplastron, is acute;
Fic. 453.—Trachemys trulla. °° each side of the gulo-humeral sulcus, thickened and rounded;

Plastron restored from Near the midline, again acute.
bones figured on plate 56. With the bone described above are a right hyoplastron, a
right hypoplastron, and a left xiphiplastron which are supposed
to have belonged to the same species. These bones are represented by figs. 4, 5, and 6 of
plate 56.

Text-fhg. 453 is a restoration of the plastron, made up from the various bones that are
described above.

This figure shows the relative dimensions of the bones and the positions of the scutes.
Fig. 4 of the plate cited presents a view of the upper surface of the hy oplastron, fig. 5 of the
hypoplastron, and fig. 6 of the xiphiplastron. The relative width of the beveled ace on
the upper side of thee bones is displayed. All the free borders are acute, especially that of the
xiphiplastron. The notch at the rear of the hinder lobe was broad, but very shallow. The
hyoplastron is 7 mm. thick on the midline, at the middle of the length. The anterior end of
the hypoplastron, on the midline, is 7 mm. thick; but further backward becomes 10 mm. The
anterior end of the xiphiplastron, at the summit of the bevel, is 7 mm. thick. The bones are
not sculptured,

350 FOSSIL TURTLES OF NORTH AMERICA.
Genus PSEUDEMYS Gray.

Shell in general like that of Trachemys. Triturating surface of the upper jaw broad all
round, with a strongly developt tuberculated median ridge. Lower jaw with broad surface
and a median ridge; its lower surface flat.

Type: Pseudemys rubriventris Leconte.

. Pseudemys extincta sp. nov.
Plate 54, fig. 13.

‘The basis of the present species is a nuchal bone belonging to the Jarman collection, the
property of Vanderbilt University. The collection was made in Hillsboro County, Florida,
from beds belonging probably to the Peace Creek formation.

This nuchal is referred to Pseude mys because of its resemblance to that of P. rubriventris,
of the Southern States. The hinder border is somewhat water-worn, but it evidently follows
closely the sutural edge. The median length is 62 mm.; the frontal width, 33 mm.; the
maximum width, 70 mm. The anterior border is acute. From this the bone thickens back-
ward about 30 mm., where is becomes 18 mm. at the midline, 15 mm. at the articulation with
the first pepe Where the bone joins the first neural it is 5 mm. thick. The nuchal scute
is 26 mm. long, 9 mm. wide in front, 19 mm. behind. The first vertebral is 48 mm. wide in
front, contracting behind this, then again expanding. The first marginal has a length, fore and
aft, of 37 mm. Its union with the first costal on this bone is only 10 mm. long.

The upper surface of this bone is in general smooth, but there are traces of a sculpture,
produced by the growth of the scutes. On the nuchal area the low ridges run parallel with the
midline; so also do those on the area of the first vertebral. Those on the areas of the first
marginals run outward and forward at an angle of about 45° with the midline. The ridges on
the areas of the first costals run outward aad backward at a small angle with the aa alice’

With the other bones from the region about Tampa Bay there come many portions of
plastrons, some of which probably belong to the present species. However, there is no way
for connecting any plastral lip, for instance, with any nuchal bone. The writer describes,
from that region, a number of species founded on nuchal bones, a quite characteristic part of
the Meletond It remains for collectors and students to find and record other bones 1n their
natural association with these various nuchals.

Pseudemys czlata sp. nov.
Plate 57, figs. 1-6; text-fig. 454.

This name is based on some bones which belong to the U. S. National Museum. They
were obtained from ‘‘Mason’s bone bed,” somewhere in Levy County, Florida, and are
supposed, but not known, to belong to the Pleistocene epoch. They may belong to the Peace
Creek formation. The bones bear the U. S. National Museum’s number 2 2508. They appear
to be parts of at least 2 individuals, one considerably larger than the other. Of the larger
individual there are present the nuchal; the distal end of the third costal, that of probably
the left side; the left fifth costal; the proximal end of the seventh right costal; the third left
peripheral; three posterior peripherals; the left epiplastron; and the left hypoplastron.
Should it happen that more than one species is here included, the nuchal bone is to be regarded
as the type.

‘This species is conspicuous for its sculpture, which resembles that of Trachemys scripta,
now living in the Southern States.

The nuchal bone (plate 57, fig. 1) is 45 mm. long and 23 mm. wide in front, and 55 mm,
wide where widest. The free border is acute; the greatest thickness, 10 mm.

The third costal is 35 mm. wide distally and nearly 5 mm. thick at the sutural edge. The
hfth costal (fig. 2) is 25 mm. wide and 7 mm. thick at the costo-vertebral sulcus, and 32 mm.
wide at the distal end. The costo-vertebral sulcus crosses the proximal end at about lo mm.
from the articulation with the neural. On the inner side of the distal half there is a prominent
ridge. In the lower end of this ridge is an excavation for the inguinal buttress. This buttress
rose about 20 mm. above the lower border of the costal. The seventh costal is 15 mm. wide

EMYDIDZ.

Us
Wn

at the costo-vertebral sulcus. The third left peripheral (fg. 3) has a length of 32 mm. along
the tree border, and a height of 30 mm. ‘The extreme width of the face which j joins the second
peripheral is 20 mm.

Fig. 4 of the plate cited illustrates the tenth left peripheral. It is 21 mm. along the acute
free edge, 35 mm. high, and it has a maximum thickness of 7mm. The uppel surface is con-
cave up and down and slightly convex fore and aft. It doe not appear to have formed a
jagged suture with the contiguous ends of the costals.

The dimensions of some : the scute areas can be only approximately determined. The
nuchal scute has a length of 17 mm. and a width of 10 mm. The anterior end of the first
vertebral has a width of 37 mm. The anterior end of the fourth vertebral scute ov erlapt the
fifth costal bone a distance of 17mm. Its width was therefore 34 mm. plus the as yet unknown
width of the neural, amounting to probably 45 mm.

The sculpture of the carapace may now be briefly described. On the nuchal bone the area
occupied by the first vertebral scute is ornamented with longitudinal ridges, 5 in a line 10 mm.
long. These ridges are more or less interrupted by the grooves concentric with the anterior
border of the scute. On the area of the first marginal scute the ridges diverge at an angle
with the midline and are interrupted by grooves parallel with the hidlifie: The distal hale of
the third costal is markt by ridges running downward and obliquely toward one edge of the
bone. These again are crost by ridges parallel with the distal end of the bone. The fifth
costal 1s similarly sculptured on the distal end, but the ridges are more irregular. The middle
third has, along the anterior border, some strong ridges anid grooves at right angles with the
sutural border, while the hinder half 1s occupied by conical elevations having little regularity.
On the third peripheral bone the area above the costo-
marginal sulcus is markt by midges running downward;
the area in front of the intermarginal sulcus ‘shows strong
ridges and grooves directed forw ard; while the area behind
wen? : this sulcus presents narrower and closer ridges, broken by

cross furrows. ‘The hinder peripherals have the area in front
\ —s of the descending sulcus markt by both vertical and hori-
woe zontal ridges; while the posterior half presents coarse ridges
that run downward and backward.

The plastron possest an anterior lip (hg. 454) whose
width was 54 mm. Its free borderis subacute. On the
upper side of the lip the horn-covered area extends backward
a distance of 15 mm. Where the bone joined the entoplastron
the thickness is 10 mm. The gular scutes overlapt the entoplastron.

The hypoplastron (plate 57, fg. 5) is 72 mm. long, and it had a width of 55 mm. at the
inguinal notch. At the midline, near the anterior end, the bone is 13 mm. thick. The free
border of the bone is acute. The horn-covered band on the upper surface is 22 mm. wide at
the hypoxiphiplastral suture.

The area occupied by the gular scutes is ornamented with ridges and grooves which are
nearly parallel with the gulo-humeral sulcus. The markings on the area of the humeral scute
are indistinct. The hypoplastron is distinctly sculptured. On the area of the abdominal scute
are short vermicular ridges, reminding one of the carapace of a trionychid. On most of the
area of the femoral scutes the sculpture suggests a tiled roof; but on the outer half there
are distinct longitudinal ridges, 7 of them in a line to mm. long.

Fig. 6 of plate 57 shows the left first costal of a smaller individual. It is markt by radiating
and concentric grooves and ridges. On the inner surface is an excavation for the inguinal
buttress. This buttress rose about 15 mm. above the lower border of the bone.

This species differs from the living 7. scripta and T. elegans in the form of the nuchal bone
and the scutes overlapping it and in having had no notches in the borders of the carapace.

The nuchal here described has a good deal of resemblance to that on which Pseudemys
extincta is based. The latter nuchal is that of a considerably larger specimen and is much
smoother, the sculptural ridges having much less elevation. The nuchal scute, too, is longe:
relatively to the length of the bone. P. concinna has narrower nuchal and first vertebral
scutes. The same is true of P. rubriventris.

Fic. 454.—Pseudemys celata. Left
half of lower surface of plastral

lip of type. X%. U.S.N.M.

FOSSIL TURTLES OF NORTH AMERICA.

oS)
n
ioe)

Genus GRAPTEMYS Agassiz.

Shell moderately elevated, with dorsal keel more or less strongly developt. Neural plates
hexagonal, with broad ends in front. Hinder border of carapace serrated. Inguinal buttresses
rather feeble, articulated to the fifth costals. Humero-pectoral sulcus crossing behind the
entoplastron. Plastron with a median notch behind. Alveolar surfaces of the upper and the
lower jaws broad, flat, and smooth. Alveolar plate of the vomer in contact with the palatines.
Choanz between the hinder borders of the orbits. Symphysis of lower jaw long, equal to
half of the distance between the quadrates.

The ope of this genus is G. geographic a, the geographic terrapin of the Mississippi
Valley (figs. 1, 2, shell). This genus is distinguisht from Chrysemys, Pseudemys, and Trach-
emys by its ae, and dentary alveolar surfaces, which are broad, flat, and without longitu-
dinal ridges. From Malaclemys it differs in having broader alveolar surfaces, and especially
in having the yvomer in contact with the palatines on the alveolar surfaces. This articulation
and the broad: flat crushing-surfaces of the jaws remind us strongly of the condition found in
Lytoloma, as well as in the Toxochelyidz and the Cheloniide; and show us that similar
structures may arise independently in different groups. The evident purpose of these broad
jaws in Graptemys is the crushing of hard food substances. G. geographica lives habitually
on mollusks. The relations of the palatines and the vomer need further study.

aes can be little doubt that Graptemys has been derived from Malaclemys

Von Reinach described (Abhandl. Senckenb. Gesellsch., xxvitt, 1900, p- 92, "plate XXX
fig. 1) a new genus and species (Promalococlemmys boule ngert) believed to be closely related
to Malaclemys. here can be hardly a doubt that what is represented 1 in his figure as the
hinder end of the plastron is in reality the anterior end of another specimen.

Graptemys? inornata (Loomis).

Figs. 455, 456.

Chrysemys inornata, Loomis, Amer. Jour. Sci. (4), XVIII, 1904, p. 429, fig 18

This species is based on a nearly complete shell which was discovered i Dr. F. B. Loomis
in the year 1903, in the Titanotherium beds of the White River deposits, in Spring Draw
Basin, 10 miles east of Creston, Meade County, South Dakota. The specimen lay beneath
the skull of a titanothere; but, as no other skeletal parts of the turtle were found, the shell
had probably drifted thither. Through the liberality of Dr. Loomis I have been enabled to
study the specimen.

In outline the shell is broadly oval, broadly rounded in front, and rather pointed behind,
The elevation of the shell in life can not be determined, it having been crusht flat during

burial. The length of the carapace (fg. 455) is 303 mm.;
the greatest Sie 253 mm. Its margin is slightly excavated

ae ene ees in front: with shallow notches at me outer onde of the pos-
ee terior marginal sulci, and with a notch in the border of the
Neural 1..... 27 22 pygal. There appears to have been a rounded carina on the
sae - a i front of the carapace, and this reappears near the rear.
Neural 7 26 23 The nuchal bone has a length of 53 mm. and a width
Neural 5 2 20 of 66 mm. The eighth neural 1s followed by 2 suprapygals.
ee _ The accompanying table presents the dimensions of the
Neural 8 9 18 median bones behind the nuchal.
on z 25 = The borders of the carapace in front of and behind the
Pypal..... a 31 bridges are acute and the bones are thin. The second per-

ipheral bone has a width of 38 mm. at right angles to the
margin of the shell; the ninth, a width of 40 mm. The sulci
between the marginal and the costal scutes run along on the peripheral bones a short distance
below the costo- peripheral sutures, except in front, where they deviate further from the sutures.
Posteriorly the sulcus crosses the midline on the rear of the second suprapygal. The nuchal
scute is 14 mm. long and 15 mm. wide.

The vertebral scutes are narrow. Each of the anterior four is about 50 mm. wide. The
fifth has an extreme width of 70 mm.

=).

EMYDID. 359

The total length of the plastron (hg. 456) 1s 272 mm.;_ but along the midline, from the
front of the plastron to the bottom of the posterior notch, the length is about 265 mm. The
anterior lobe has a length of about 85 mm. and a width of 140 mm. At the suture between the
epiplastrals and the hyoplastra the width is 122 mm., and this width is continued backward
about 22 mm. further. The entoplastron is 51 mm. wide. The anterior lip projects somewhat
and has a width of 60 mm.

The posterior lobe has a width of 134 mm. and a total length of go mm. Toward the hindei
extremity the lobe narrows rather rapidly and is posteriorly deeply notcht. The humero-
pectoral sulcus passes behind the entoplastron. The gulars extend along the midline for

456.

Fics. 455 AND 456.—Graptemys inornata. Carapace and plastron of type. about }.

455. Carapace. 456. Plastron.

47 mm.; the humerals, 2g mm.; the pectorals, 30 mm.; the abdominals, 63 mm.; the femorals,
53 mm.; the anals, 3o mm. The bridges have a width of 100 mm.

The present species is here vefeered with doubt to the genus Graptemys Agassiz. It can
hardly belong to the genus Chrysemys as that is here defined and the type of w hich is C. picta.
The shell of this White River species has some resemblance to that of Graptemys geo ogra phic a,
having a low rounded dorsal carina and an elongated first suprapygal, like the living species
just aeeaed. The species may belong to either Pseudemys or Trachemys; but it will be neces-

sary to have the skull in order to detenmiie; its relationships with certainty.

Genus TERRAPENE Merrem.

Shell usually short and broad, rarely elongated. Neural bones hexagonal, with the broader
end forward. The eighth neural usually absent. Plastron as broad as the opening of the
carapace, composed of two distinct portions moyable on each other and the carapace, there
being a ligamentous hinge between the hyoplastra and the hypoplastra and another on each
side between the bones mentioned and the carapace. Zygomatic arch complete, deficient, 01
wanting. Alveolar surfaces of the jaws narrow and without ridges. Choanz between fronts
of orbits. Digits with little or no web. Tail short.

Type: Perraipe ne carolina (Linn).

The known members of this genus are confined to North America. The species are
closely related, and their number is not certainly determined. On the number of the digits
of the hinder feet and the condition of the zygomatic arch the genus has been, especially by

360 FOSSIL TURTLES OF NORTH AMERICA.

Cope, split into a number of genera. The type of Terrapene is T. carolina, and is extremely
variable. Three fossil species have been described by Cope—T. eurypygia, T.marnochi, and
T. anguillulata—but the latter appears to be identical with J. eurypygra. They all belong to
Pie ctocene deposits. Another species, 7. putnami, was described by Hay from supposed
Pliocene of Alifia River, Florida.

The shell of Terrapene is usually nearly as broad as long, but that of 7. major is less than
three-fourths as broad as long. It is sometimes high and vaulted, but occasionally, as in T.
ornata, it is rather deprest.

Nothing is known regarding the origin of the genus. It appears not improbable that it
has been deriv ed from Ee ys, of Sohich Emys orbicularis of Europe is the type. Of Emys there

ics. 457 AND 458.—Terrapene ornata. }. Specimen in A. M.N. H.

457- Carapace. 458. Plastron.

is also an American species, £. blanding:, an inhabitant of the northern United States and
Canada as far westward as Wisconsin. In Emys there is a transverse hinge between the hyo-
plastrals and the hypoplastrals, less perfect than in Terrapene, and the lobes thus formed are
somewhat movable on the carapace. It would require no great modifications of the shell and
skull of Emys to transform it into Terrapene. Emys is found’ in Pleistocene deposits of various
parts of Europe, and it is probable that the genus had its origin there, and that it migrated
thence to North America. Doubtless, Terrapene was developt in North America.

Fig. 457 is a representation of the carapace of Terrapene ornata; while fig. 458 represents
the plastron. The species now inhabits Kansas.

Key to Fossi, Spectes oF TERRAPENE.

A‘. Plastron very thick, the thickness of the hypoplastron being nearly one-third its length. . putnamz

A*. Plastron much thinner.

a’. Plastron with flat hinder lobe, its free border sic eae at end of femoro-anal sulcus.

Middle of back flat transversely. ...... sis oo... marnochi
a’. Plastron with hinder lobe convex, the free houiles not emarginate. Middle of back

Concave. transversely secssetes 2 ecraje spre set desks cts een cote, cite eueneneeee .... canaliculata
a®. Closely related to T. carolina. Werebral, scutes ane: he fifth in contact with the

tenth marginal. ; : eurypygia

Terrapene putnami Hay.
Plate 56, figs. 7, 8; text-figs. 459-462.
Terrapene putnam, Hay, Bull. Amer. Mus. Nat. Hist., xx11, 1906, p. 30, figs. 4-7.

The present species is based on a single hypoplastral bone which was placed by Professor
F. W. Putnam, then of the American Museum of Natural History, in the hands of the writer

EMYDID. 301

for examination. This and some other bones were dredged by him in the Alifia River, Florida,
about a mile above its entrance into Tampa Bay. With this bone there were obtained remains
of some species of Trachemys and a peripheral of a very large Testudo, possibly T. crassi-
scutata (Leidy). The writer has been informed that these bones were accompanied by bones
of horses, tapirs, etc. The remains seem therefore to agree with those taken from the Peace
Creek beds, near Arcadia, DeSoto County, of the same state. The latter bone bed has been
declared to be of older Pliocene age, but the evidence appears to be contradictory.

This new species of box-tortoise is remarkable for its size and the great thickness of its
plastron. The length of the left hypoplastron (plate 56, fig. 7),-measured along the midline, is
73 mm., and the width ts almost exactly the same. If this bone had the same ratio to the other

459: a \ =
; 4
3 \

Fic. 459 AND 460.—Terrapene putnam:. lHypoplastron of type. x z.

459. Section from articulation with opposite hypoplastron (on right) to lateral hinge (on left).
460. Face articulating with its fellow. Anterior end of the bone at right hand.

portions of the shell that the corresponding bone has in 7. carolina, the carapace must have
been 265 mm. long, and the width about 200 mm.

At the midline of the plastron, just in front of the union of the hypoplastron with the
xiphiplastron (fg. 460, on the left), the former bone is 22.5 mm. thick. In a specimen of T.
carolina whose hypoplastron is 38 mm. wide the thickness at the point named is 4 mm. or less.
In the fossil the thickness becomes reduced laterally, so that at two-fifths the distance toward
the lateral hinge (fig. 459) it is only 12 mm. It then increases and at the hinge is 15 mm.
Toward the anterior end of the bone the thickness diminishes to 12 mm.

The hinder portion of the lateral hinge (plate 56, fg. 8) is broken away. At its anterior
end there is a deep and rough pit for a process proceeding from the fourth and fifth peripherals,

401.

Fics. 461 AND 462.—Terrapene putnami?. Fragments of carapace. X 3.
Specimen in Vanderbilt University.
461. Left side of front of carapace. c.p.1, part of first costal plate; m.s.2, m. 5.3, m. 5.4, second, third, and
fourth marginal scutes.
462. Rear of carapace. m.s.11, m.s.12, eleventh and twelfth raarginal scutes; per. 11, eleventh peripheral; py,
pygal; spy, suprapygal.
asin TZ. carolina. The hinder border of this pit is about 22 mm. behind the anterior border of
the bone. Behind this comes the flat, rough, and perpendicular surface, about 14 mm. high,
that articulated loosely with the fifth and sixth peripherals, forming one side of the lateral
hinge. This surface 1s relatively broader and flatter than in 7. carolina and resembles more
that found in ZT. ornata. It is likewise broader and flatter than the same surface in 7. mar-
nochi, judging from the carapace in the American Museum of Natural History so identified.
In that specimen the hinge surface on the carapace is only 8 mm. wide.
The hyohypoplastral hinge hardly differs from that of TJ. carolina, except in thickness,
which in T. putnamz is close to 12 mm. The upper half of the hinge (fig. 460) is rough for the

362 FOSSIL TURTLES OF NORTH AMERICA.

attachment of the ligament. Near the outer end of this hinge nearly the whole surface is rough.
The lower half of the anterior face projects in front of the upper half and is mostly smooth
and was covered with the horny epidermis.

On the lower surface of the bone is seen the abdomino-femoral sulcus. “The abdominal
scutes were, in fore-and-aft extent, 33 mm. laterally and 55 mm. at the midline. On this surface
are some faint grooves produced by the growth of the scutes. “Two of these grooves near the
anterior border are especially conspicuous. This species is dedicated to Prof. Frederick W.
Putnam, the distinguisht archeologist and ethnologist.

In a considerable collection of fossil turtle bones sent to him from Vanderbilt University,
Nashville, ennessee, the writer finds 2 fragments of the carapace of a large box-tortoise.
This collection was obtained in Hillsboro County, Florida, by Dr. W. H. Jarman and belongs
to the university named above. The fragments probably belong to 7. putnam.

One portion (fg. 461) consists of the areas occupied by the second, third, and a part of
the fourth left marginal scutes and a portion of the contiguous first costal. “This fragment,
compared with the carapace here referred to Cope’s T. marnoch1, indicates a carapace about
320 mm. long. The bones are solidly co-ossified and the sutures obliterated, showing that the
individual was aged. Where the suture between the first and second peripherals should occur
the bone is 14 mm. thick. The free edge is acute. In the area covered by the fourth marginal
the border is revolute. The second and the third marginals measure each 33 mm. along the
free border and are about 20 mm. high.

In the same lot of bones is a fragment (fg. 462) furnishing the suprapygal, the pygal, and
the right and left eleventh peripherals. The bones are co-ossifed, but the sutures may be
traced. The individual probably had a length of about 250 mm. The free edge is acute and
somewhat recurved. The eleventh peripheral is 10 mm. thick. The fifth vertebral scute is
50 mm. wide, while that of the carapace of 7. marnochi is 40 mm. wide. ‘The two twelfth
marginals taken together measure 40 mm.; those of T. marnocht, 37 mm.; the height of the
scutes in the two species is the same, 13 mm. The height of the eleventh marginal is 28 mm.;
that of J. marnochi, only 32 mm. It is evident that the Florida specimen does not belong to
I marnochi.

Terrapene marnochi (Cope).
Plate 58, figs. 1, 2.

Ctstudo marnochit, Cope, Proc. Amer. Philos. Soc., xvi, 1878, p. 229; Amer. Naturalist, xxi, 1889,
p- 161, Feb.

Cistudo marnochit, Corr, Amer. Naturalist, x1x, 1885, p.1208.

Terrapene marnochi1, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 449.

This species was founded on the posterior lobe of an individual which was discovered by
Gabriel W. Marnock, in the Equus beds of Atascosa County, Texas. What has become of the
specimen is not known. It does not appear to be in the Cope collection of fossil reptiles in the
American Museum of Natural History at New York. The specimen was not heured by Cope.
The following is his description of the type:

Represented by the posterior lobe of the plastron of an individual of twice the bulk of the exist-
ing North American Cistudos. It is broadly rounded posteriorly, and there is an emargination at the
femoro-anal dermal suture. The anterior suture is straight, as is also the lateral, which measures
more than a third the length of the entire lobe. On the upper side of the angle included by these
sutures is the fossa for fixed attachment with the carapace. The beveled face of the fore edge of the
lobe is quite wide. The dermal sutures are well marked. The anal scuta are large, their median
length being half that of the lobe. The common femoral suture is only half as long as the ventral.
The inferior surface is nearly flat in every direction, and the surface is smooth. The posterior
border of the specimen is broken away.

This species was obtained from the same formation as the last, by Gabriel W. Marnock, to

whom I dedicate it.

In the American Museum there is a large carapace (plate 58, figs. 1, 2) of a species of this
genus which was found in the Cope collection of fossil reptiles, but which appears never to
have been mentioned by Professor Cope. Accompanying it is a label stating that it was
found in the ‘Elephant beds,” on San Diego Creek, Texas, and had been sent by Mr. William

EMYDID&. 303
Taylor. We learn from the American Naturalist (vol. x1x, 1885, p. 1208) that this gentleman
had collected materials for Professor Cope in the Equus beds, in the region about San Diego.
This locality is about 80 miles south of that which furnisht the type of 7. marnochi.

The catalog number of the San Diego specimen is 3936. The matrix was a mixture of
gravel and sand.

It is assumed for the present that the specimen referred to belongs to 7. marnochi. The type
is spoken of as being large. Unfortunately Professor Cope gave no measurements. ‘The length
of the carapace of the San Diego specimen is 215 mm.; the breadth is 141 mm. The width
is therefore two-thirds the length, indicating an elongated form. JT. ornata, of Kansas, is
nearly as wide as long. 7. major, of Meouicianes is relatively elongated, but even here the
width is three-fourths OF the length. The outline of the carapace is like that of J. major, the
hinder portion being only slightly wider than the middle. ‘Vhe width at the line of the hinge
is 137 mm.; at the seventh peripherals, 147 mm. The height is 95 mm., two-thirds the width.
The middle of the back is rather fat. There are traces of a dorsal keel anteriorly, and these
traces are better defined on the area of the third vertebral scute, and are yet perceptible on the
fourth. On each side of this keel, on the third and fourth vertebral scutes, there is a distinct
broad, but shallow, channel. Most of the area of the fifth scute is concave.

The margins of the carapace are little fared upward, far
less than those of 7. mayor. A distinct keel runs along each

SIAL Length. | Width. side, joining the anterior free border of the carapace with the
: - |— hinder free border.
I ° 28 The individual was an aged one, and the sutures between
S 3
2 47 41 the bones are completely obliterated.
2 i ~
2 49 ne The sulci are everywhere deeply imprest. The vertebral
4 48 42 Pa I
5 36 39 scutes are unusually narrow. The table herewith presents the

—— _ = dimensions of these scutes. The lengths are taken along the
midline; the widths are the maximum.

The anterior end of the first vertebral projects forward between the first pair of marginals.
Similarly the anterior ends of the third and fourth vertebrals project forward each into the
hinder border of the scute in front. The marginal scutes are large. The first rises 22 mm.
from the free border, the sixth 23 mm. above the lateral keel, and the ninth 27 mm. above the
free border.

463a. 463. 4635.

464a. 405a.
Fics. 463-465.—Terrapene canaltculata. Portions of the type. 3-
463. Fourth right peripheral, with sections of the ends (a, anterior; b, posterior).

464. Region of seventh and eighth marginal scutes, with section (a).
465. Entoplastron and section (a) of border of hinder lobe.

Terrapene canaliculata Hay.
Figs. 463-465.
Terrapene canaltculata, Hay, Bull. Amer. Mus. Nat. Hist., xxu, 1907, p. 850, figs. 5-7.

The fragmentary remains that testify to the former existence of this species belong to the
U.S. National Museum, having been sent there many years ago by Dr. J. P. po They
had been found on either Whitemarsh or Skedaway Island, below Savannah, Georgia. The

304 FOSSIL TURTLES OF NORTH AMERICA.

exact age of the deposits is not known, but they belong probably either to the late Pliocene
or to the Pleistocene.

The individual was of larger size than any belonging to any existing species. The right
fourth peripheral (hg. 463) ee: a length of 26 mm., from which we may infer that the ae
had a length of about 220 mm. The anterior end of this peripheral has a thickness of 8 mm.;
the hinder end a thickness of 1g mm. On the outer surface is a sharp longitudinal keel, which
ran from the free border of the anterior peripherals to that of the posterior peripherals. This
keel borders outwardly a broad gutter-like groove. Fig. 464 shows the region of the seventh and
eighth marginal scutes, with a section across the seventh. Portions of the second and third cos-
tal scutes are presented. The thickness of the costals varies from 4 mm. to 6mm. A frag-
ment of the dorsal region shows that the midline of the carapace was concave transversely.

The lateral hinge-line appears to have had a length of about 70 mm. _ Its thickness is 10
mm. The entoplastron (hg. 465) is subcircular in outline. It varies in thickness from 5 mm.
to7 mm. The border of the hinder lobe, at the hypoxiphiplastral suture, 1s 13.5 mm.

Terrapene eurypygia (Cope).
Figs. 466-470.

Cistudo eurypygia, Cork, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 124.
Terrapene eurypygta, Hay, Proc. Acad. Nat. Sci. Phila. 1902, p. 385, figs. 6, 7; Bibliog. and Cat. Foss
Vert. N. A., 1902, p. 449; Maryland Geol. Surv., Pliocene and Pleistocene, 1896, p. 160, pl. x1, fig. 2.

The present species has as its type a fragment of the hinder portion of the carapace which
was discovered by Dr. Samuel Harrison, on Oxford Neck, Talbot County, Maryland, in
Pleistocene deposits, associated with remains of Elephas primigenius, Cervus canadensis,
Odocoileus virginianus, and Chelydra serpentina. This type is now in the American Museum
at New York and bears the catalog number 1484. It is here represented by hg. 466.

Cope’s type presents a portion of the right seventh costal plate, portions of the costals of the
eighth pair, the suprapygal, the pygal, and the tenth and eleventh peripherals. Those charac-
ters which in this type appear to distinguish the species from 7. carolina are the greater breadth
of the fifth vertebral scute and the union of this vertebral with the tenth marginal scute. It is
proper to remark here that the present writer, in his description of this species in the Pro-
ceedings of the Philadelphia Academy, called the tenth marginal the ninth.

An estimate makes it probable that the individual to which the type fragment belonged
had a length of carapace equal to about 140 mm. The fifth vertebral scute had a width of 40
mm. The width of this vertebral in 7. carolina is variable, but out of 6 individuals observed,
only 1, with shell 130 mm. long, had this scute as much as 39 mm. wide. In 7. eurypygra
the fifth vertebral joins the tenth marginal scute by a sulcus 4.5 mm. long. Usually in 7.
carolina these two scutes fail to reach each other by some millimeters. As stated by the author
elsewhere, an examination of eighteen specimens of 7. carolina showed that in only one the
fifth vertebral was 1n contact ith the tenth marginal on both sides, while in another these
scutes were in contact on only one side of the carapace. Relying on the type alone we might
conclude that possibly TJ. eurypygza is only an individual variation of 7. carolina.

In 1899 (Jour. Phila. Acad., x1, pp. 193-267) Professor Cope described various remains
of the vertebrates which had been collected by Messrs. Dixon aud Mercer in the Port ae
cave. Among other things there were three tortoises found, viz.: Clemm ys insculpta, C. per-
crassa, and Toxaspis | Terrape ne) anguillulata. There Kdbneed to the collection, however,
another box-tortoise which was not mentioned by Cope, and was perhaps not seen by him.
These remains consist of almost the whole of the plastron and of various fragments of the
carapace and the nght humerus.

An examination of these bones showed that they belonged either to Terrapene carolina or
to a species closely related to it. It was soon observed that the tenth, or antepenultimate,
marginal scute comes into contact with the last vertebral (fig. 4672), a condition which recalled
Cope’s Cistudo eurypygia, and a close comparison proved that they are identical, one of the
portions of the Port Kennedy specimen being fortunately the right margin of the rear of the
shell from near the midline to the hinge. The question therefore arises w Hether or not the new
material confirms Cope’s view of the distinctness of the species.

EMYDID&. 305

The unusual width of the fourth and fifth vertebral scutes is proved by Cope’s type and
confirmed by the Port Kennedy specimen. Belonging to the latter is a fragment of the cara-
pace presenting a part of the nuchal, a part of the first and second costals and the first and
second peripherals (fig. 4676). In T. carolina the first vertebral does not usually encroach on
the first peripheral bone; in the fragment alluded to above, the vertebral reaches over on the
first peripheral nearly to the sulcus between the first and second marginals. The anterior
vertebral must have been 34 mm. wide, about 6 mm. wider than in a specimen ot T. carolina
at hand. We must conclude that the other vertebrals were wider than they commonly are in
T. carolina. An estimate makes it probable that the fourth vertebral in 7. eurypygia, type, was
about 42 mm. wide.

Fig. 467a presents a view of the fragment of the rear of the carapace of the Port Kennedy
specimen, the interrupted lines having been added in order to show the position of the frag-
ment. The crossing of the sulci on the upper portion of the drawing indicates the presence of
a small scute cut off from the fifth vertebral, a slight abnormality. In fig. 467a the peripherals

s
t e
i 2
Se a mee
*»
pon a
- ah » } ae SS
i j ress 4
/ m rae mlo.t + :
a ‘ 7 ~~
a : oN
466. ew
/
SPY : 4 /
3 ns | /
+ = \ per:10 | per.9 \ wt S/
, ms msid “mstO ms 9 3 X Vi
oa ‘, =
4670. 467).
Fics. 466 anp 467.—Terrapene eurypygia. 1. Portions of Carapace.
466. Rear of carapace of type. c.p.7, ¢. p. 8, seventh and eighth costals; m.s. 11, m.s. 12, eleventh and twelfth

marginal scutes; per. 10, per. 11, peripherals; py, pygal; spy, suprapygal.

467a. Rear of carapace. c.p. 8, eighth costal plate; per.g, per. 10, per. 11, ninth to eleventh peripherals; m.s. 9,
m.s. 10, m.$. 11, m.$.12, ninth to twelfth marginal scutes; py, pygal; spy, suprapygal. The letters m. s.
of ninth marginal lie partly on tenth marginal.

467b. Front of carapace. c. p. 1, first costal bone; nu. p., nuchal bone.

and marginals are indicated. The tenth scute is the one lying partly on the ninth peripheral
and partly on the tenth. In both figures the bony sutures are represented by zigzag lines,
while the sulci between the scutes are shown by dotted lines.

The plastron of the Port Kennedy specimen is 131 mm. long. In general it resembles that
of T. carolina. The width of the hinder lobe is 79 mm.; the length was almost exactly the
same. In the case of 6 specimens of 7. carolina examined the width of this lobe is from 4 to
6 mm. wider than long; in one individual the width is 2 mm. less than the length. The form
and dimensions of the scutes of the plastron are essentially as they are in T . carolina.

A study of the plastron of the Port Kennedy specimen makes it evident that this portion of
the shell was almost everywhere thicker than in the corresponding parts of T. carolina. Nearly
the whole of the border of the anterior lobe is thicker and with a more rounded edge. The
hypoplastron of 7. carolina at the hinge is 3 mm. thick; that of 7. eurypygia, 4 mm. The
sloping, scute-covered border of the hinder lobe, at the union of hypoplastron and xiphiplas-
tron, is in J. carolina 5 mm. thick; in T. eurypygra, 7 mm. thick. This border is also wider
in the latter species than in any specimens of the living species at hand.

Fig. 468 represents the plastron of the specimen described above from the Port Kennedy
cave. It resembles that of 7. carolina but appears to be relatively more elongated.

300 FOSSIL TURTLES OF NORTH AMERICA.

Professor Cope in 1899 (Jour. Phila. Acad., x1, p. 196, plate xix, fig. 1) described and
figured a box-tortoise which he called Toxaspis anguillulatus. Of this tortoise he had at com-
mand five fragmentary carapaces on beds of matrix, three parts of plastrons, and two moulds
of carapaces. All these had been obtained in the cave near Port Kennedy.

The type of Cope’s Toxas prs anguillulatus is number 155 of the collection of the Philadel-
phia Academy. This is figured as cited in the synonymy at the head of this article; but the
figure is poorly printed and does not well show the structure. A diagram of the specimen
(fig. 469) is here presented; but even in the specimen some
sutures are obscure and on the left side the hinder peripherals

Neural. Length. Width.
| a have been somewhat displaced.

Fig. 469: Professor Cope did not compare his species with the one
3 16 17 which he had described in 1869. The present writer, having
es - examined Cope’s types of both species, concludes that they are
6 9 15 identical. Cope stated that his type carapace, No. 155, is of
7 13 12 larger size than that of any of the existing species of what he

eee called the Terrapenide. However, a comparison with a shell
; 16 a of T. carolina shows that the carapace was not more than 140
2 13 16 mm. long, perhaps not more than 130 mm.; and occasional
3 15 a individuals of 7. carolina attain that size, while some of TJ.

major become still larger. Cope believed that his 7. anguil-
lulatus had a more deprest shell than any of the living species, but this may be doubted.
Another of Cope’s specimens is numbered 154. This (fg. 470) furnishes the three anterior
neurals. Their measurements are given in the table above.

468. 470). 469.

Fics. 468-470.—T errapene eurypygia. Portions of shells.

468. Plastron.

469. Rear of carapace of type of Toxasprs anguillulatus.

470a. Front of carapace. No. 154 Phila. Acad.

470b. Portion of hypoplastra and xiphiplastra. No. 154 Phila. Acad.

From the measurements of No. 155 (hg. 469), given in the table above, it will be
seen that all the neurals, except the first and the last, have the width considerably greater than
the length. They appear to be somewhat broader than those of T. carolina.

The eighth neural was not developt. The seventh is not as long as the width of the seventh
costals; and, as a result of these conditions, the seventh costals meet on the midline behind the
seventh neural and the eighth costals join by their whole proximal width. In some specimens
of T. carolina there is a long and narrow eighth neural.

EMYDID&. 307

In the type of 7. anguillulatus, as shown in the figure (hg. 469), the hinder peripherals on
the left have been pushed forward over the ends of the costals.

The suprapygal is 11 mm. high and 25 mm. long. The eighth peripheral is 5.5 mm. thick.

From No. 154 we learn that the first vertebral scute was 38 mm. wide and the second
gomm. From No. 155 it is seen that the second and third were each 44 mm. wide; the fourth,
42mm.; and the fifth, 4o mm. What is of special interest is that in No. 155 the tenth marginal
scute comes into contact with the outer extremity of the fifth vertebral scute. This is the
character on which 7. eurypygia was based. A fragment of the plastron of No. 154 of the
Philadelphia Academy shows that the femoro-anal sulcus extends forward to the hypoxiphi-
plastral suture. Cope states that this character had not been observed by him in any other
species of the family. It is, however, occasionally seen in 7. carolina.

Cope describes a peculiar and fine sculpture as present on the type of his Toxas pis anguil-
lulatus. This is a well-markt vermiculation. At the borders of the costals the ridges place
themselves at right angles with the sutures. A similar vermiculation is seen in the type of 7.
eurypygia, but no modification of it is seen where the seventh costal joins the eighth.

Family TESTUDINID Gray.

Cryptodira having most of the characters of the Emydidz, but modified for a more strictly
terrestrial life. Size medium to very large. Jaws fitted for a vegetable diet. Palate vaulted.
Zygomatic and_postorbital arches present; the temporal roof not otherwise represented,
Stapedial notch closed. Neck retractile within the shell. Plastron suturally united with the
carapace, with the buttresses rarely ascending within the carapace. The bridge broad. Neural
bones sometimes mostly hexagonal; but often, especially in T estudo, octagonal ones alternating
with tetragonal. Penultimate suprapygal usually bifurcate, with its limbs resting on the hinder
peripherals and enclosing the hindermost suprapygal. Plastral bones nine. ‘The epiplastrals
usually thickened and projecting as a lip. The procoracoid process forming with the body of
the scapula more than a right angle. Coracoids greatly expanded at the median border.
Humerus with the radial and ulnar processes approximated on the ventral side. Digits short,
without rudiment of web. Phalanges not more than 2 in any digit; all shortened; anterior
claws usually 5, sometimes only 4; hinder claws 4. Sulcus between the costal and the marginal
scutes usually coinciding with the sutures between the costal and peripheral bones.

The present family is here regarded as including § living genera—T estudo, Gopherus,
Kinyxis, Pyxts, and Homopus. It seems not improbable that a more accurate study of
the skeletons of living tortoises would result in the establishment of additional genera. Auinyxis
is confined to tropical Africa, Pyxis to Madagascar, and Homopus to southern and western
Africa. Testudo is represented in the present fauna, or has been within historical times, by
more than forty species, and these belong to South America, the Galapagos Islands, Europe,
Asia, Africa, Madagascar, and the Aldabra, Maritius, Seychelles, Comoro, and Rodriguez
Islands. Gopherus (Xerobates) includes the Testudinide of North America, altogether 3
species.

The extinct genera belonging to this family are Hadrianus, Achilemys, and Stylemys.
Besides the extinct species referred to the genera just named, a few belong to Homopus and
many to Testudo.

Extinct species of Testudo are known with certainty from the Lower Oligocene to the
deposits of the recent period. A very large species, T. atlas, is known from the Pliocene of the
Siwalik Hills, India. Its shell reached a length of 6 feet. Other Pliocene species have been
described from Europe, among them 7. perpiniana, from France. Various species are known
from the Miocene of Europe, among them JZ. leberonis, from Mount Lebéron, France. 7.
gigas is known from a nearly complete specimen and 7. eurysternum from fragments, both from
the Upper Oligocene ot France. A specifically unnamed specimen of the genus is noticed by
Lydekker (Cat. Foss. Rept., Brit. Mus., 111, p. gt) as being represented by an anterior periph-
eral from the Lower Oligocene of France. As remarkt by Lydekker (op. cit., p. 72) there
is no known reason why some of the Lower Tertiary species described under the name
Testudo may not belong in reality to Hadrianus. Zittel states that the oldest known land-
tortoise in Europe is T. lamanoni Gray, from the Oligocene gypsmergel of Aix, in Provence.

308 FOSSIL TURTLES OF NORTH AMERICA.
‘This formation is placed by Lapparent at the base of the Oligocene. The specimen is a very
imperfect one, and it may be said that the genus is only approximately determinable. Dr.
A. E. Andrews (Surv. Dept., Pub. Works Ministry, Geol. Surv. Egypt, 1903; Catalogue Tert.
Vert. Fayum, Egypt, 1906, p. 278, plate xxiv) has described a land-tortoise from the Upper
Eocene of Egypt to which he has given the name Testudo ammon. If a true Testudo, it is the
oldest known. The publisht figures show that the neurals are variable in form, but the relation-
ships to typical Testudo are so close that it may be accepted as belonging to this genus. In
some respects it appears to be intermediate between Testudo and Hadrianus.

The oldest known representative of the family is Hadrianus majusculus, of the Wasatch
beds of New Mexico.

The following table presents a list of the North American fossil species belonging to the

Testudinida so arranged as to exhibit their geological sequence:

Species.

Equus, or

Pleistocene. ee
| Sheridan beds.

Testudo hexagonata, T. Jaticaudata, T. atascose (Texas).

Testudo crassiscutata (Florida).

Peace Creek.

Pliocene. —
| Blanco. Testudo pe rtenuis, T. turgida, T. campester (Texas).
mecnids klettiana, T. undata (New Mexico); T. niobrariensis, T. Sholland® T. edz |
Loup Fork (Nebraska); T. impensa (Montana); T. gilberti, T. orthopygia (Kansas); T.
arenivaga (Nebraska).
Miocene: Deep Rica: Testudo pansa, T. osborniana (Colorado); T. arenivaga (Nebraska); T. emiliz (South

and Dakota).
Pawnee Creek. Testudo vaga (Wyoming); ?T. peragrans, T. farri, T. inusitata (Montana).
John Day Stylemys conspecta, S. capax (Oregon); S. RARE (California:

Oligocene. White River.

Testudo brontops, T. thomsoni (South Dakota); ?T. peragrans (Montana); T.ligonia,
T. cultrata, T. laticunea, T. amphithorax, T. quadrata (Colorado);
(Assiniboia); Stylemys nebrascensis (South Dakota, North Dakota, Nebraska,

T. exornata |

Wyoming).
Unita. | Hadrianus turidus (Utah). -
Jackson. Rdnaaue schucherti (Mississippi).
Eocene. Bridger. Hadrianus aaa non Achilemys allabiata (W yoming).

Wasatch. Hadrianus majusculus (New Mexico), H. corsoni? (New Mexico:

Puerco.

We can not doubt that the predecessors of Hadrianus will yet be found in the Puerco beds
or their equivalents. We may even look confidently for more primitively constructed Tes-
tudinidz in some of the Upper Cretaceous deposits. They are more likely to occur in river
valley formations or zolian accumulations.

Considering the large size of Testudo brontops, the grade of its differentiations, and the
great number of species “ol T estudo which made their appearance in the Oreodon beds of the
Oligocene we may be sure that species of the genus will yet be discovered in some of the upper
fernations of the Eocene of America; as they have already been found in the Upper Eocene
of northern Africa.

Nevertheless, it seems to the writer that the family was, in the earlier half of the Eocene,
in a stage of development represented by Hadrianus corsoni of the Bridger, and that Testudo
ee with its only slightly differentiated costal plates, represents a stage which existed
possibly even in the Upper Eocene. It may be concluded therefore that any members of the
family that shall be found in the Puerco and Upper Cretaceous will display further approxi-
mations to the Emydidz.

It will be interesting to consider in the light of knowledge derived from both the living and
the fossil species of the family the special chame ters which they have dev elopt since shee first
appearance: as we might say, the goal toward which they have been striving.

With regard to the shell we see that it is usually very high and convex. ‘There are various
exceptions to this statement; nevertheless, we find no species so deprest as some of the Emy-
didz; and the height and convexity will average much higher than among the species of the

TESTUDINID. 369

latter family. The ends to be subserved by this cony exity may be various. We may suppose
that it would be much more difficult for a carnivorous animal to effect an entrance into such
a shell than into one deprest and whose borders may be spanned by the j jaws of the enemy.
Again, the vaulted shell provides greater space for the lungs; and the investigations credited
by Hoffmann (Brown's Klass. and Ordn.: =a at P. 344) to Dr. Joseph Jones but really
made by Louis Agassiz (Contrib. Nat. Hist. U. S., vol. , p- 283) show that the capacity of the
lungs of Gopherus polyphemus is much greater a ra of Emydide having an equal length
of hele except Terrapene, which has camels habits of life. Even the earlier known forms of
the Testudinide, as Hadrianus and Stylemys, have the shell high and vaulted; and this fact
suggests that the deprest form of some existing species may he due to adaptations to recent
conditions. The flattened carapace of Gopherus polyphemus, for instance, may have relation
to the burrowing habits of the species.

Among the Emy didz the neural bones are usually hexagonal, with the broader end of the
bone in fant: Such, too, is the case with some of the Testudinid#. In Stylemys nebrascensts
we find this condition prevailing; but occasionally a specimen is found in which the second
one is octagonal. In S. conspecta and S. capax, of the John Day beds, there is further advance-
ment—the second is octagonal, while the third is tetragonal. Too much weight ought not to
be attacht to single specimens having modifications of this sort; as is illustrated by the fact
that in the American Museum of Natural History there is a specimen of Chelydra ser pentina
in which the second, fourth, and fifth neurals are octagonal, while the third is tetragonal.
Nevertheless, among the Testudinide a high degree of differentiation of the neurals is the rule.
When we come to the genus TJ estudo itself we fad the alternation of octagonal with tetragonal
neurals the prevailing arrangement. In Kinyxis, according to Boulenger’s figure (Cat.
Chelonians, fig. 41), the neurals are hexagonal with the broad end behind, a form the reverse
of that common among the Emydide. In Homopus the emydoid condition prevails, except
that the third is tetragonal.

The costals have suffered remarkable modifications among the Testudinida. In most
other turtles these plates, from the second to the sixth inclusive, have the proximal and the
distal ends of each costal of nearly the same width. In most species of Testudo and in Gopherus
the proximal ends of the second, fourth, and sixth are much narrowed, while the distal ends
are greatly widened. On the other hand, the proximal ends of the third and fifth are broad,
while the distal ends are narrow. The proximal ends of costals 3 and 4 are in contact with 3
neurals each. The 5 costals concerned appear thus to be dovetailed with one another. The
mechanical advantages of this arrangement have been discust by A. Bienz (Rev. suisse
Zool., etc., 111, 1895, p. 99). These modifications of the costals are not conspicuous in Had-
rianus ane in Stylemys nebrascensis, but they become very manifest in the species of Stylemys
from the John Day beds. In Testudo brontops of the lowest Oligocene, the neurals display a
high grade of differentiation, and, in harmony with this, the upper ends of the costals are modi-
fied so as to unite alternately with 1 and with 3 neurals; but there is no great difference in the

widths of the upper and lower ends of each costal.

In most turtles the position of the rib is very distinctly shown on the visceral side of each
costal plate; and the heads of the ribs are broad and thick. These heads join their respective
vertebral centra at the anterior ends of the latter, and at least the anterior ones come into
contact also with the next centrum in advance. In the Testudinidz the ribs show only faintly
on the under side of the costals and the rib-heads are usually greatly reduced. Ina specimen
of Testudo radiata from Madagascar, having the bel 305 mm. long, the rib-heads of the
second to the sixth costal plates may be 3o mm. long; but they are very slender blades 5 mm,
thick horizontally and 2 mm. high, expanding sews toward the proximal ends. In
Gopherus only the merest traces of the rib-heads remain of those belonging to the costals in
front of the seventh; and these vestiges adhere to the centra and to the Aenea, In 7. tabulata
the rib-heads are all much reduced. Many of these are wholly free from the costal plates and
have become co-ossified with the under sides of the neural bones. Intermediate stages are to
be seen in this species. This condition illustrates well the manner in which the ribs, probably
free from the costals in the most primitive turtles, have become consolidated with them.

When we examine Hadrianus we find that the rib-heads were somewhat reduced, but still
of considerable size. In Stylemys they are still more reduced. A careful examination of a

24,

3790 FOSSIL TURTLES OF NORTH AMERICA.
series of fossil turtles of the various geological periods would doubtless show a gradual reduction
of the size of the rib-heads in this family.

The distal ends of the costal ribs of the Testudinida have become reduced in an interesting
way. Inthe great majority of turtles the distal ends of these ribs project more or less bey ond
the margins of the costal plates, and the projecting ends are usually received by pits in the
adjacent. peripherals. In most of the Testudinide the ends of the ribs have disappeared.
In Gopherus we find that, instead of the rib entering the peripheral, a broad process of the
peripheral rises and enters a notch on the inside of the costal plate, an interesting reversal of
conditions. The relations of the ribs and peripherals in 7. radiata are very similar. In T.
tabulata no conspicuous process is found on either the costal plate or on the peripheral. In
Hadrianus, as in Gopherus and most species of Testudo, a process of the peripheral enters an
excavation in the inner surface of the costal. On the other hand, in Stylemys the extremity
of the rib fits into a pit in a peripheral, just as in the Emydide.

In typical Testudinide of to-day the peripherals and contiguous costals are articulated,
not only by the processes just described, but also by digitating sutures, and these are usually
better developt than in the Emydide. In 7. radiata long slivers of bone arising from the
peripherals interdigitate with shorter processes from the costals. On the other hand, 1
Stylemys and Hadrianus there appear to have been no such digitations; but the rounded
border of each peripheral joins the similar border of the neighboring costal.

In the majority of the Testudinida the epiplastral bones are thickened for some distance
on each side of their symphysis. The thickening takes place on the upper side of the bones.
At the hinder border of the thickening, on each side of the midline, the elevation drops off
suddenly to the level of the entoplastron. In many species the ledge thus formed and looking
backward is excavated more or less deeply. Usually the thickened epiplastra project more or
less beyond the general curve of the rest of the anterior lobe, and there is thus formed a con-
spicuous epiplastral lip. This lip presents various forms in the different species and, tho
subject to variations, it furnishes valuable specific characters. The lip is conspicuously
developt in Hadrianus, as in most species of Testudo. In Stylemys the front of the epiplastra
is thickened, but it does not project beyond the curvature of the rest of the lobe.

The hinder end of the plastron is usually, but not always, notcht.

At the anterior ends of the bridges the hyoplastron of each side sends upward a process,
the axillary buttress, which artic tilates with the first costal plate. Usually this buttress does not
pass above the lower border of the costal. At the hinder end of the bridge the hypoplastron
sends up an inguinal buttress, which also rarely rises above the lower bories of the costals
involved. In Gopherus and the species of Te studo already mentioned this buttress 1s articu-
lated with the middle of the lower border of the sixth costal; but it appears that in some
other living genera of the family, possibly in some other species of Testudo, the buttress is
attacht somewhat further forward. In Hadrianus corsoni the buttress ascends a short distance
on the inner side of the sixth costal. In Stylemys nebrascensts it is articulated between the fifth
and sixth costals, rising a short distance above their lower borders. It is evident that there has
been a tendency among the Testudinidz to push the buttress backward, and thus increase
the width of the bridge. The purpose has apparently been to diminish as much as possible
the hinder opening of the shell.

The shoulder-girdle of the Testudinide appears to be distinguisht from that of the
Emydidz in two respects: The coracoid is greatly expanded at its inner, or mesial border, and
the procoracoid process makes an obtuse angle with the body of the scapula. Probably in all
Emydide the coracoid is only slightly expanded at the mesial border and the procoracoid
process makes an acute angle with the body of the bone.

The humerus, in probably all members of the family, is characterized by having the radial
and ulnar processes both twisted toward the ventral side of the bone, thus making the angle
between them small. Usually the humerus is considerably bent, but often no more so than in
some species of Emydide. ; ;

In most species of the family there are 5 digits belonging to each forelimb; but occasionally
there are only 4. No digit possesses more than 2 phalanges. How this reduction has been
brought about is an interesting question. A similar reduction of the phalanges to two in each
digit occurs in the foretoot of Terrapene as observed by Dr. George Baur (Zool. Anzeiger, Xv,
1892, p. 159),

TESTUDINID&. 371

The metacarpal bones are very short, usually broader than long. ‘The whole foot is short
and heavy, resembling that of an elephant.

The pelvis is constructed on the plan of that of the Emydide.

The femur is distinguisht from that of the Emydidz in the union of the two trochanters
by a ridge which runs nearly on the level of the head of the bone, when the femur is held perpen-
dicularly. Between this ridge and the head there is a pit of some depth. The metatarsals and
the phalanges are not so short as the corresponding bones of the forelimb; but they are much
shorter than those of the Emydidz. There are only 4 digits, the fifth metatarsal being reduced
toa rudiment. No digit has more than 2 phalanges.

Little is known regarding the feet of Hadrianus, but we may confidently expect to find only
2 phalanges in each digit. While the structure of the digits of Stylemys is not certainly deter-
mined all the known face point to conditions similar to aliose found in the other genera of the
family.

The most striking differences between the skulls of the Testudinida and those of the Emy-
didz are found in the excavation of the roof of the mouth of the members of the former
family and in the closure of the stapedial notch. The palate rises high above the level of the
crushing-surfaces of the upper jaws and the vault thus formed is pared back to between the
quadrates. The skull of Hadrianus is wholly unknown. The skull of Stylemys presents the
same vaulting as that of Testudo.

The geographical distribution of the Testudinidz (fg. 14, p. 33) within historical times is a
most important and interesting question, and it has within recent years provoked much dis-
cussion. Dr. Albert Gunther (Proc. Linnean Soc. Lond., cx, 1898, p. 26), as an appendix to
his presidential address on this subject, has given a list of §1 papers which have a bearing on
the question. The most difficult question to settle j is how the ancestors of the gigantic tortoises
which once abounded on the Galapagos Islands and on various groups in the Indian Ocean
reacht those islands. Originally it was assumed that these ancestors were accidental arrivals,
borne thither by oceanic currents; but in 1891 Dr. George Baur (Amer. Naturalist, xxv,
pp. 217-229; 307-326) promulgated the theory that these islands were only the volcanic peaks
of a great tract of land which had at one time connected these islands with one another and
with the western coast of America. In a number of papers succeeding this announcement he
defended this theory. For Dr. Baur’s views the reader is referred to his w ritings, a list of which
was publisht by Dr. W. M. Wheeler in 1899 (Amer. Naturalist, xxx11, pp. 23~30).

The present writer does not intend to enter upon a full discussion of the question, but he
records it as his conviction that in general terms Dr. Baur’s position is correct. Probably the
simplest way to account, on the old theory, for the presence of these tortoises on these remote
islands is to suppose that, some time in the distant past,a gravid female was borne by currents,
swimming or floating ona raft of fallen timber; that she landed on one of the islands; and that
her descendants were in some similar way distributed to the other islands of the group. But
these Testudinide are probably of all turtles the least adapted for such transportation. In the
water they would almost certainly drown within a few hours. Nor is it probable that a raft of
wood would hold together long enough or well enough to carry one of these turtles, wholly incap-
able of clinging to such objects, the distance of 700 miles. If this almost miracle of transpor-
tation had Ben accomplisht, it must have been repeated on a smaller scale many times, in
order to populate the various islands. And all this work must have been accomplisht long ago,
and long ago have ceast; have been accomplisht long enough ago to permit the evolution of
a divciiet species on each island, and have ceast long enough : ago that new arrivals should
not have disturbed this differentiation. It is difhcult to imagine why the distribution of these
turtles between the various islands should not have contaled. if it had ever been possible.

Probably the chances for lizards to reach the Galapagos Islands from the American coast
and from one island to the other are much better than those favoring the turtles. Yet we find
the same variation among the lizards of the islands that we find among the turtles. Four
genera are represented on these islands, of which two, Tropidurus and Phyllodactylus, are
represented on the American coast. Two others, Conolophus and Amblyrhynchus, are peculiat
to the islands in question. It seems that the opportunities for the accidental transportation of
lizards are to-day as good as they could ever have been, yet no species are common to the
American coast and the Galapagos Islands. We would be justified in expecting something

N

FOSSIL TURTLES OF NORTH AMERICA.

Os
~™

more than a few common species. Along the western coast of Central and South America, 1n
situations where they are liable to be earacd down by rivers to the Pacific Ocean, there live
about 50 genera of lizards. How can it be explained that such a fragment of these has reacht
the Galapagos Islands?

An instructive chart, publisht by Dr. Alexander Agassiz (Bull. Mus. Comp. Zool., Xx111,
pp- 50-74, plate 11) exhibits the floor of the ocean in that region, and demonstrates the presence
of a tongue of uplift which extends from the Galapagos islands to the Central American coast
just oak of the Gulf of Panama. It seems therefore probable that at some time in the past,
evidently after the Oligocene, more probably during the Miocene, there existed a mass of land
which included the Galapagos Islands and joined narrowly the Central American coast. This
land mass might be compared to the island of Madagascar, with the long axis at right angles
with the neighboring continent, instead of parallel with it. Over the narrow bridge tea
past the ancestors of the present turtles of those islands and a few genera of lizards, together
with some other animals and sundry plants. The descendants of these invaders have differen-
tiated and formed a part of the present fauna and flora of the islands. It is not unlikely that
some genera which invaded that land perisht afterwards.

When we try to account for the presence of the gigantic tortoises found at one time, but now
nearly extinct, on the islands of the Indian Oecait we are met with the same difhculties that
we have been considering. If the conformation of the land and sea was the same as now when
the ancestors of these tortoises reacht their island homes, they must have been transported over
the seas for distances varying from 250 to 750 miles.

The solution of the various problems connected with the distribution of animals and plants
in southern Africa and southern Asia and the islands of the Indian Ocean have driven many
geologists, zoologists, and botanists to the conclusion that at one time there was a land connect-
tion between India and South Africa, across the Indian Ocean. For a masterly discussion
of this question the reader is referred to the presidential address of Mr. W. T. Blanford before
the Geological Society of London in 1896 (Quart. Jour. Geol. Soc. Proc., p. 98), and also to
Giinther’s address already cited. Blanford concludes that there was such a land connection
as has been mentioned above, that this continued thruout the Upper Cretaceous, and was
broken up into islands at an early Tertiary date. Dr. Giinther adopts this conclusion and adds
that ‘‘the slow evolution of this chelonian tvpe (Testudo) which has scarcely changed since
the Eocene, and its wide distribution over the Northern Hemisphere, justify the supposition
that it was in existence already before the Tertiary, before the bridge was broken through
which allowed of its passage southwards or northwards. ’

That primitive Testudinide were in existence toward the close of the Upper Cretaceous is
very probable, but that the genus Testudo had at that time made its appearance there is no
proof, no probability. We do not know of its existence with certainty before the Upper Eocene
in Africa and the lowest Oligocene in America. The less advanct forms of eis family, as
FHadrianus and related genera, may have reacht India or South Africa by the end of the
Cretaceous, but we have no evidence of this. Hence, unless we are willing to betake ourselves
to what ought to be our last refuge and hold that Testudo had a polyphyletic origin (using this
term in its original sense), that the Testudos of America and those of the eastern continents
sprang independently from Hadrzanus or from the latter genus and another, we must place at
a later date than the early Eocene the arrival of the ancestors of the gigantic tortoises on Mada- °
gascar and the islands of the western portion of the Indian Ocean.

The conclusion reacht by Mr. Richard Lydekker regarding the time of separation of Mad-
agascar from the mainland was that this occ urred during the Miocene (Geog. Hist. Mammals,
p. 223). Mr. Blanford had previously concluded that che depression of 1,000 fathoms or more
Ww hich led to the formation of the Mozambique Channel had taken place during Phocene or
Postpliocene times. However, the recent discovery of species that can hardly ‘be separated
from T estudo, in the Fayum in Egypt, makes it necessary to recognize the fact that members of
the genus had reacht that continent as early at least as the Upper Eocene.

Testudinide at their various stages of development are known at earlier dates in North
America than elsewhere. It seems thereFore! probable that North America was their center of
distribution. From western North America they may be supposed to have reacht Central
America and to have migrated thence to the present Galapagos Islands, From western North

TESTUDINID&. 373

America, taking a northwestern direction, they past into Asia over the bridge of land which
occupied the position of Bering Strait. Passing westward they entered Europe. Others
spreading southwestward peopled India and the strip of land which connected the latter
country with Africa, and which now, greatly deprest, is represented by Madagascar and
various groups of islands. From this land they entered Africa itself.

The living Testudinida which have been designated as “ ojgantic tortoises” all belong to
the genus Testudo. The species of Hadrianus of the Eocene were worthy of being called
gigantic. That the gigantic forms, living and extinct, may, in some cases, have been derived
from small species and that some of the smaller modern species are the descendants of extinct
gigantic ancestors, are possibilities. Within historical times gigantic tortoises have lived only
on islands, where there are no large carnivorous mammals. On the other hand, the large
Testudinidz of North America, from the Lower Eocene to the Pliocene, were exposed to the
attacks of large carnivora.

As remarkt by Mr. R. Lydekker, the gigantic tortoises became extinct on all the conti-
nents at the close of the Pliocene. This appears to be true of North America, since the 3 species

ee

iy yy Uy,

Fic. 471.—Testudo sumeirei. View of living animal. After Rothschild’s figure, greatly reduced.
/ Ss a 5 :

recorded from the Equus beds are all of moderate size. Nevertheless, Dr. Leidy has figured
the claw phalange (Cont. Extinct Vert. Fauna West. Terrs., 1873, pl. xxxiil, fig. 21) of a species
of Testudo found in Pleistocene deposits in Hardin County, Texas. The individual must
have been one of great size. ‘This phalange 1s now in the American Museum. We do not
know why some of the Phocene gigantic tortoises should not have had descendants in the
Quaternary worthy of accompanying the great mammals of that period.

Fig. 470 represents Testudo sumetre: Sauzier, a gigantic tortoise living in Port Louis,
Mauritius. This figure is reproduced from a plate publisht by the Hon. Walter Rothschild
(Novitates Zoologica, 1, 1894, plate x1) over the name Testudo indica. This tortoise was men-
tioned in a treaty made in 1810. The length of the carapace is 40 inches (1015 mm.); that of
the plastron, 28 inches (711 mm.).

ANALYSIS OF GENERA.

A. FEpiplastral lip projecting abruptly from front of carapace.

a. Neural bones hexagonal. Eocene species. . . nen. ; Hadrianus

aa. Usually some octagonal and quadrangular neurals; Oligocene to Recent species T estudo
AA. Fpiplastral lip not projecting abruptly or far beyond gulo-humeral sulci.

b. Epiplastral lip not thickened backward above; Bridger 2 Achilemys

bb. Epiplastral lip thickened backward above; Oligocene Stylemys

Genus HADRIANUS Cope.
Testudinide with the plastron extensively united to the carapace by suture; with short
axillary and inguinal buttresses, the latter of which ascend within the sixth costal plates; no
plastral hinge. Epiplastral lip strongly developt; entoplastron wholly in front of the pectoral

374 FOSSIL TURTLES OF NORTH AMERICA.

scutes; hinder lobe of plastron notcht. Of the neural plates the second and third are hexagonal
with the shortest sides directed backward; the third is quadrilateral; and the remainder are
hexagonal, with the shortest sides directed forward. Three suprapygals, of which the penulti-
mate is notcht behind and receives the third. Costals with no great difference between the
widths of the proximal and distal ends. Two supracaudal scutes. Shoulder and pelvic girdles
as in Testudo. Skull unknown. Cervical vertebra and limb bones not well known.

Type: T estudo corsoni Leidy.

Without having the skull and the distal limb bones, it is not possible to say positively that
this genus belongs to the Testudinida, as limited in this work. The shell and shoulder and
pelvic girdles, however, present many characters which indicate close relationships with the
modern land-tortoises. We find in this genus apparently the beginnings of those modifications
of the shell which characterize the genus Testudo. In most species of the latter the neural
plates are alternately tetragonal and hexagonal; and the second, fourth, and sixth costals are
narrow at the proximal ends and wide at the distal ends, while the third, fifth, and seventh are
wide proximally and narrow distally. In Hadrianus the third neural is quadrate, as in TJ estudo,
and the corresponding costals are widened proximally to come into contact each with three
neurals also, asin Testudo. The other costals differ only slightly in the widths of their opposite
ends. As in Testudo, the connection between the costals and the peripherals is a rather loose
one; the sulcus between the costal and marginal scutes follows closely the sutures between the
peripheral and costal bones; the epiplastrals form a conspicuous lip; the humero-pectoral
sulcus falls behind the entoplastron; and the pectoral scutes are rather narrow. Even Stylemys,
belonging to a later period, appears to be less advanct in many respects than Hadrianus.

In various writings (the latest being his Vertebrata of the Tertiary Formations of the West,
1884, p. 113) Prof. E. D. Cope assigned as the character distinguishing Hadrianus from the
other Testudinide a divided supracaudal scute. Three species of the genus Testudo, as
recognized by Boulenger, also have this scute divided. It seems to the author that the un-
differentiated condition of the shell furnishes a more satisfactory basis for the genus. Mr.
Richard Lydekker (Cat. Foss. Rept. and _Amphib. Brit. Mus., 11, p. 72) gives, among other
characters distinguishing Hadrianus, the ‘‘narrow vertebral shields and the elongated cued
bones which are hexagonal, with short postero-lateral surfaces” [sides]. The neurals, however,
are not of unusual narrowness. As to their form, Mr. Lydekker cites a igure by Leidy which
represents only the 3 anterior neurals, but another figure by Leidy in the same work (Ext.
Vert. Fauna West. Terrs, plate xxx, fig. 1) shows that the fourth and fifth neurals have the
antero-lateral sides short.

So far as known at present the members of this genus are confined to the Eocene. The
oldest-known species is H. majusculus Hay from the Wasatch of New Mexico; the most
recent species is H. tumidus Hay, from the Upper Uinta. As suggested by Mr. ise
some of the Eocene and Miocene species of Europe that have been referred to Te studo may
reality belong to Hadrranus.

ANALYSIS OF THE KNOWN SPECIES.

. Wasatch. Very high peripherals. Pectoral scutes more than half as wide aeee midline

as the abdominals..............0 000 ccc ccccceeeseveeeveseeveeees oo... mayusculus
2. Bridger. Peripherals of moderate height. P ectoral scutes less than half as eee on mid-

line as the abdominals............ Af , ; corsont
2. Uinta. Peripherals high. Pectoral scutes less than one-third as wide as the abdominals. . tumidus
~) 5 . . . .
4. Jackson formation. Pectoral scutes one-ninth as wide as the abdominals. . . . a schucherti

Hadrianus majusculus Hay.
Plate 59, fig. 1; text-fig. 472.
?Hadrianus corsont1, Cope, Syst. Cat. Vertebrata Eocene N. Mex., 1874, p. 36; Append. LL. Ann. Rep.
Chief Engineers (Wheeler’s Surv.), 1875, p. 1016 (separata, p. 96)
Hadrianus mayusculus, Hay, Amer. Jour. Scie (4), XVIII, 1904, p. 271, plate XV; text-hg. 5:
The species here described is founded on a somewhat damaged shell which belongs to the

Marsh collection in Peabody Museum, at Yale University. Accompanying this shell is a label
which bears the following record: “Turtle from foot of bluff, west side of Murderer’s Gap.

ESTUDINIDZ. 375

In large fragment of sandstone that had fallen from the bluff. Nov. 19, 1876. D. Baldwin.”
Another label states that the specimen came from the “Eocene Bad Lands, Gallina, New
Mexico.” This locality appears to be in Rio Arriba County, of the territory mentioned.
The deposits whence the shell was derived are in all probability a portion of the Wasatch. On
the carapace is found Professor Marsh’s receipt number 927

The specimen is somewhat distorted and injured by pressure, being slightly comprest and
thrust toward the left side. Crushing has also affected the upper median region, so that most
of the neurals have been displaced. Ata later time these were weathered and fractured; and it
is now quite impossible to restore them to their proper positions. The mght border from the
fifth peripheral to the tenth has been weathered and removed. In the same way the right side
of the hinder part of the plastron has been damaged.

The length of the carapace (plate 59, fig. 1) in a direct line is 530 mm. The greatest width
was at least 440 mm. In formit was high and archt. Over the limbs the peripherals were con-
siderably flared. The anterior border was truncate; the hinder border rounded and scallopt.
The free borders of all the anterior and posterior peripherals have acute edges.

On account of crushing the dimensions of the nuchal bone can not be determined. Appar-
ently it extends backward but little further than the first peripheral. While portions of most of
the neurals remain, little regarding them can be said. The seventh has a length of 40
mm. The eighth is small. There are apparently 3 suprapygals. Of these the anterior
appears to have been 23 mm. long and to have had an anterior concave and a posterior convex

border. The second suprapygal is bifurcate, with the lateral

Width Width branches resting on the eleventh peripheral. “The third supra-
Costal- | proximally.| distally. | pygal is lozenge-shaped and is included between the branches
= ~ of the second: suprapygal bone and the pygal. The costals
2 62 77 vary considerably in width; but unlike those of the species of
: = a Testudo, the upper and the lower ends differ little in width.
5 46 44 The table herewith gives the dimensions of the costals, excluding

6 45 45 the first.
- = The peripherals are large, those of the bridge region rising

much higher than in H/. corsont. The first and second each
occupy about 80 mm. of the free border of the carapace and
extend backward from the border 72 mm. Those of the bridge region rise a distance of
go mm. above the slight carina which runs from the free edge of the third peripheral to the
edge of the seventh. The eleventh peripheral rises 70 mm. from the free border. The
pygal is 45 mm. high in the midline; 62 mm. wide at the upper border; and 40 mm. wide
at the lower border. The upper border is notcht for the lower border of the hindermost
suprapygal.

The sutures between the bridge peripherals coincide at their upper ends closely with those
between the costals, except that between the fourth and fifth peripherals. The sutures between
the bridge peripherals and the plastral bones appear to have been obliterated.

The sulci between the dermal scutes of the carapace are narrow and shallow, but most of
them lie in rather deep grooves in the bones. Of the vertebrals none can be satisfactorily mapt,
except the fifth. This is about 150 mm. wide behind. Its anterior border appears to have
crost the eighth neural. Itis probable that the others were narrow. The sulci between the
costal scutes and the marginals follow closely the sutures between the costal and the peripheral
bones, except that in font the sulci he on the nuchal and the first and second peripheral
bones; while in the rear the sulcus crosses from side to side the hindermost suprapygal. There
are two very distinct supracaudal scutes, a right and a left.

The total length of the plastron (hg. 472) was about that of the carapace, 530mm. The
anterior lobe extends somewhat in front of the anterior border of the carapace, and has a length
of 180 mm. The width was at least 266 mm. There is a rather prominent lip, which projects
beyond the general border of the lobe. This lip is truncated, or only slightly rounded in front.
The width at the base is 120 mm., in front about 88 mm. The free borders of the lobe are
subacute, but the front of the lip is considerably thickened. On the upper side the thicken-
ing increases until it is 33 mm. There is on this upper surface a median ridge, on each side
of which 1s a longitudinal valley.

370 FOSSIL TURTLES OF NORTH AMERICA.

The entoplastron appears to have been of the same form as in F/, corsoni. Its length is
80 mm., its width 120 mm. The length of the bridge is 206 mm.

On account of lateral crushing the width of the posterior lobe can not be accurately
determined. Its length is 175 mm. It is conspicuously notcht behind, the depth of the notch
being 45 mm.

The gular scutes probably overlap slightly the entoplastron, but this is not certain. The
humero-pectoral sulcus skirts the hinder border of the

fiwew \ entoplastron. ‘The pectoral scutes have a form quite differ-
} \ ent from that of Hl. corsoni. They are narrow just

oN mesiad of the axillary notch, but grow wider as they
yr \ approach the midline, attaining there a width of 75 mm.

At the midline the abdominals have a fore-and-aft extent
\ of 140 mm., the femorals 80 mm., the anals about 55 mm.
The sulci of the plastron are rather narrow and shallow, but
those of the bridge lie in deep grooves.

This species differs from H. corsonz in several respects.
The most conspicuous is perhaps the height of the periph-
erals, especially those above the bridges. The form and
width of the pectoral scutes too is distinctive. The bridge
appears to be shorter in comparison with the length of
the anterior lobe. The hinder borders of the carapace
are more scallopt than in H. corsont.

Prof. E. D. Cope referred some remains of Hadri-
anus from the Wasatch of New Mexico to H. corsoni; while
other remains he regarded as a distinct species, which,
however, he did not name. His specimens appear to be
lost. It is doubtful whether any of them belonged to the
Bridger species.

Hadrianus majusculus is interesting ‘because of the fact that it is the oldest-known repre-
sentative of the family Testudinide.

Fic. 472.—Hadrianus mayusculus.
Plastron of type. > %.

Hadrianus corsoni (Leidy).
Plates 60, 61; text-figs. 473-479.

Testudo corsont, Lewy, Proc. Acad. Nat. Sci. Phila. 1871, p. 154; U. S. Geol. Surv. Montana, etc.,
1872, p. 366; Proc. Acad. Nat. Sci. ees 1872, p. 268; Contrib. Extinct Vert. Fauna West. Terrs.,
1873, pp- 132, 339, plate xi, figs. 1,2; plate xv, fg. 7; plate xxix, figs. 2-4; plate xxx, figs. tas

Emys cartert, Leipy, Proc. Mead, Nat. Ser. Phila. 1871, p. 228; Amer: Jour. Sci., (3) 1, 1871, p. ;

U. S. Geol. Surv. Mont., etc., 1872, p. 367; Contrib. Ext. Vert. Fauna West. Terrs., 1873, ne XL.

T estudo hadrianus, Cope, Paleont. Bull. No. 1, 1872; Proc. Amer. Philos. Soc., xu, 1873, p- 463.

Hadrianus quadratus, Cope, Proc. Amer. Philos. Bist xil, 1873, p. 468.

Hadrianus octonarius, Copr, Paleont. Bull..No. 2, 1872; Proc. Amer. Philos. Soc., xu, 1873, p. 468;
U.S. Geol. Sury. ‘Teris:, 6th. Ann. Rept., 1872 (1873), p. 630; Amer. Naturalist, xv1, 1882, p. 992,
figs. 11-13; Vert. Tert. Form. West. 1884, p. 140, plate xx, figs. I-4.—OsBorn, ScoTT, and SPEIR,
Pal. Rept. Princeton Sci. Exped. 1877, p.g5.—Hay, Bibliog. and GaeyRoss. Vert. N. A., 1902, p. 450.

Hadrianus corsoni, Core, U. S. Geol. Surv. Terrs., 6th. Ann. “Rept., 1872 (1873), p. 631; Syst. Cat.
Vert. Eocene N. Mex., 1873, p- 36; ?Ann. Rept: Chief Engineers, Explor. W. tooth Merid., 1875,
p- 1016 (of separata, p. 96); ?Wheeler’s Rept. U.S. Geog. Surv. W. 1ooth Merid., 1v, 1877, p. 58,
plate xxiv, figs. 36, 37; Amer. Naturalist, xvi, 1882, p. 9g2; Vert. Tert. Form. West, 1884, p. 141.—
Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 450; Amer. Geologist, xxXv, 1905, p- 333-
This species was based on the anterior portion of a plastron which was discovered by Dr.

Corson at the Grizzly Buttes, about 15 miles south of east of Fort Bridger, Wyoming, and

which was sent for study to Dr. Leidy. This was figured by the latter icon in his Contribu-

tions to the Extinct Fauna of the Western Territories, plate xv, hg. 7, and is in the Academy
of Natural Science, at Philadelphia. In 1871 Dr. Leidy made a trip to Fort Bridger and
obtained a number of specimens of the same species, and these added much to the knowledge of
the animal. Among the remains secured was a large plastron which, on account of post-
mortem injury to the lip, Dr. Leidy did not recognize and which he made the type of the species

TESTUDINID&. Say

Emys cartert. A still larger and nearly complete plastron was correctly identified; likewise
a portion of a carapace of another individual, including the neurals and the proximal portions
of most of the costals. Some of the materials obtained by Dr. Leidy exemplify the great varia-
tion found in the form of the anterior lip. Professor Cope in the same year, 1871, discovered
several specimens which he recognized as belonging to Leidy’s species; but he gave no extended
description and no figures. Under the name Hadrianus octonarius he described and figured
a large and nearly perfect shell which is now in the U. S. National Museum. For reasons
given below this is referred by the present writer to 1. corsonz.

Besides the specimens described by Dr. Leidy and Professor Cope, a number of other well-
preserved shells have been discovered. One of the largest of these is now in the museum of

ak i
IOWA AAA Nan ie pm

473. 474. 475-
Fics. 473-475.—Hadrianus corsont. Carapace and plastron. X%. No. 6027 A. M.N.H.

473. Carapace.
474. Rear of carapace. c. p.7, seventh costal; ».8, eighth neural;

Spy, 1, Spy. 2, first and second suprapygals; py, third suprapygal.
475. Plastron.

Princeton University, and will be referred to again. During the summer of 1903 the American
Museum expedition to the Bridger Eocene, in the region east of Fort Bridger, collected 3
more or less complete turtles of this species. One of these, No. 6027, furnishes the following
description :

The plastron is almost wholly uninjured. The carapace lacks a little of the anterior margin,
some portions of the bridge peripherals, the pygal, a part of the eleventh peripheral, and the
right peripherals behind the axillary notch, except the tenth and a part of the eleventh. The
shell appears not to have suffered any considerable depression during fossilization.

The length of the carapace (plate 60; text-fig. 473) in a straight line from the front to the
rear is 590 mm.; its greatest width close to 455 mm.; its greatest height, which is toward the
rear, 215 mm. The border in front is between rounded and truncate; behind, the outline is
broadly rounded. The peripherals over the limbs are slightly flared; the pygal region seems

378 FOSSIL TURTLES OF NORTH AMERICA.

to have sloped steeply. The carapace is broadly archt along the median line and more sharply
archt from side to side.

The nuchal bone occupied 100 mm. of the free border; its maximum width is 120 mm.;
and its length is 110 mm. The neurals agree very closely with those of Leidy’s plate xxx, fig. 1
of his Contributions. Not one is octagonal. The first is clavate; the second is hexagonal, aad
comes into contact with both the second and the third pairs of costal plates; the third is quad-
rilateral and in contact with the third pair of costals only. The succeeding neurals are all hex-
agonal, and each is in contact with the corresponding pair of costals and with the pair
immediately in front. The anterior four neurals are longer than broad; the posterior four are
broader than long.

Behind the feurals Is a series of 3 suprapygals (fg. 474). The first, or most anterior, is
42 mm. long and 34 mm. wide. It is in contact with the eighth pair of costals. The second
suprapygal is bifurcate, as in Testudo, and the forks rest on the eleventh peripherals. The
third suprapygal is triangular, with a straight and broad base, and lies between the forks of
the second suprapygal. It is evident that there were three suprapygals in the specimen repre-
sented by Leidy, plate xxx, fig. 1, of his Contributions, etc.

The costals display only the eulest stages of the differentiation seen in the genus T estudo.
Only those of the third pair articulate with 3 neurals. The table herewith presents the widths

of the upper and lower ends. Most of the costals are crost by

ann ae low ridges, which mark the stages of growth of the dermal scutes.

Costal. | oper end. lower end. The peripherals are relatively low, as compared with those
of most species of the genus Testudo. Those of the bridge have
1 67 38 a height of about 80 mm., as do also those of the axillary and
? = a inguinal regions.
- va 67 The vertebral scutes are of moderate width and have
5 63 51 straight sides. The first, second, and fourth are each 106 mm.
: a wide; the third, 111 mm.; the fifth, 179 mm. at its hinder
8 oe = end. The first vertebral is 80 mm. wide at the anterior end.

The nuchal scute is 40 mm. long and about 17 mm. wide. The

sulcus between the marginal scutes and the costals follows closely
the suture between the underlying bones, except that i it crosses the first peripheral some dis-
tance below its upper border.

The plastron (plate 61; text-fig. 475) has an extreme length of 550 mm. The anterior end
projects about 35 mm. in front of the carapace. The central parts of the plastron are somewhat
concave. The anterior lobe is 175 mm. long and 246 mm. wide at the base. The free borders
areacute. The anterior lip projects slightly ‘beyond the general contour of the lobe, and 35 mm.
beyond the line joining the points where gulo- humeral sulci cross the free border. Between
these points the lip is 118 mm. wide. On its superior surface the lip extends backward 75 mm.
The upper surface is slightly convex from side to side; the lower surface is nearly flat. The
anterior outline is rounded.

The entoplastron is narrow in front and broad behind. The length in the median line is
115 mm.; the greatest breadth, 134 mm.

The length of the posterior lobe is 157 mm.; the width at the base, 240 mm. The width
of the posterior notch is about 80 mm.; the depth, 30 mm. The fore-and-aft extent of the
bridge is 215 mm. The free edges of this lobe are acute. At the inguinal notch the border of
the hypoplastron is 36 mm. thick. From the summit of the wall thus formed the bone slopes
to the free edge at an angle of about 45°.

The gular scutes encroach somewhat on the entoplastron. The humero-pectoral sulcus is
tangent to the entoplastron behind. The pectoral scutes meet along the midline about 62 mm.;
the abdominals, 163 mm.; the femorals, 73 mm.; the anals, 43 mm.

A specimen in the American Museum of Natural History, No. 1068, belonging to the Cope
collection, having a plastron 410 mm. long, agrees well with the preceding description. How-
ever, the anterior vertebral scute is urn-shaped, with an anterior width of 44 mm. and a pos-
terior width of 85 mm.

Another shell obtained by the American Museum expedition of 1903, No. 6026, has a
length of 700 mm. The carapace is badly fractured and some portions of it are missing. The

TESTUDINID. 379
sutures are so fine that it is not easy to trace them. The nuchal scute is extremely narrow; the
supracaudal is divided at the midline. The peripherals over the limbs are considerably flared,
but the pygal is nearly perpendicular. The plastron is more concave than in the specimen here
first described. Also the lip is more truncate in front. The pectoral scutes are only 48 mm.
wide at the midline. The notch in the hinder end of the plastron is 150 mm. wide and 46 mm.
deep; being thus much wider than in the specimen here first described. The apices on each
side of the notch are rather narrow and pointed.

No. 5958 of the same museum was collected in 1903. It has a length of 720 mm. The
plastral lip has the form shown in the figure of Cope’s H. octonarius (Vert. Tert. Form. West,
plate xx), having parallel sides and a truncated front. The notch and the apices also resemble
those of Cope’s H. octonarius. The entoplastron is damaged, so that its form can not be deter-
mined. The shell is considerably crusht laterally.

No. 10082 of the Museum at Princeton University was collected at Smith’s Fork, in south-
western Wyoming, in 1878. It has been regarded as being H. octonarius. Its length is 790 mm.;

476a. 476b.

479.

1

Fics. 476-479.—Hadrianus corsont. xX 5.

476. Scapula and coracoid. No.1068A.M.N.H. a,seen from below; 5, seen fromin front. cor, coracoid;
peor, procoracoid process; scap, scapula.

477. Pelvis seen from below. No. 1068 A.M.N.H. #/, iliurn; fsch, ischium; pub, pubis.

478. Pelvis seen from left side.

479- Right ilium of large individual. No. 6026 A. M. N.H.

its width, 635 mm.; its height, 305 mm. The shell is nearly complete. The carapace is convex
transversely but rather flat on the middle line. From front to the rear it is convex with the
pygal region quite steep. The front and rear are somewhat truncate. All the peripherals
are acute-edged. The sutures bounding the neurals are so fine that they have not been
determined. The first vertebral scute is 62 mm. wide in front, 135 mm. wide behind, thus
differing from that of other specimens in being very narrow in front. The second is 135 mm.
wide; the third, 144 mm.; the fourth, 163 mm.; the fifth, 270 mm. The nuchal is 48 mm.
long and 36 mm. wide.

The plastron has a length of about 775 mm. It is very concave, and has probably been
that of a male. The lip projects about 80 mm. beyond the front of the carapace. It is large
and of rather unusual form. The width at the base is 113 mm. but it expands toward the front

380 FOSSIL TURTLES OF NORTH AMERICA.

to 132mm. There isa slight notch in the midline, and the lateral angles are rounded off. The
notch in the hinder lobe of the plastron is 55 mm. deep. The humero-pectoral sulcus falls
about 18 mm. behind the entoplastron. The pectoral scutes are 55 mm. wide at the midline.

It appears to the present writer that the specimen on which Professor Cope based his H.
octonarius belongs really to H/. corson1. Cope states that the shell “‘is of an elongated form,
strongly contracted at the bridge, but expanded and arched above the limbs.” This narrowness
of ine fossil is deceptive, having, largely at least, been produced by distortion during fossiliza-
tion. The right side is crusht inward from 50 mm. to 100 mm. and the hyoplastron and hypo-
plastron of one side have been pushed so as to overlap those of the other side. From the mesial
border of the left hyoplastron at its hinder edge to the left outline of the shell is about 260 mm.,
which would make the width of the shell about 520 mm., instead of 437 mm., as given by Cope.
This estimate makes the shell but little narrower than that of the specimen first described above,
and this can hardly be regarded as H. octonarius. Cope has also stated that the entoplastron
is heart-shaped; but this is an error, caused by not carefully distinguishing fractures from
sutures. Its form is that seen in H. corsoni. The upper surface of the lip is concave, whereas
in other specimens it is commonly convex or flat.

It is evident that there are great variations in the form of the lip and likewise in the size
and form of the notch in the hinder lobe. Furthermore there appears to be no unvarying
association of a large lip with a large hinder notch. It is therefore necessary to consider the
various forms as belonging to a single species.

Professor Cope identified some fragments of turtles found in the Wasatch deposits of New
Mexico, on Gallinas River, as belonging to H. corsoni. It is more probable that these materials
belonged to the species which the present writer has named Hadrianus majusculus.

Portions of the internal skeleton of this species are rarely found. No skull has yet been
secured. No. 1068 of the American Museum of Natural History, a half-grown individual col-
lected by Cope, furnishes the greater part of both scapula, both coracoids, both ischia,
both pubes, the acetabular end of one ilium, 2 phalanges, and 2 damaged cervical vertebra.

Fig. 476 represents the scapula and coracoid of the left side, as viewed from below; it also
shows the left scapula as seen from in front. It will be observed that the scapula is a stout bone,
with more than a right angle between the body of the bone and the procoracoid process. Both
the body and the process are comprest, except at the ends distal from the glenoid process. ‘The
coracoids broaden toward the mesial border, as in the genus T estudo.

Fig. 477 presents a view of the pelvis from below. The pelvis resembles more that of
Te studo, especially that of 7. radrata of Madagascar, than that of any of the Emydide at the
writer's command. ‘The lateral process of the pubis is placed mostly i in front of the ischio-
pubic foramina. The section of the process is nearly circular in section. From the hinder border
of each ischium there projects a pointed process. The extremities of these processes are distant
from each other more than half the distance between the lower borders of the acetabula.
In hg. 478 the pelvis is seen from the left side, a portion of the illum being missing. Fig. 479
shows the nght ilium of No. 6026 A. M. N. H. From its upper end there projects backward
a sharp process, which received the outer ends of the two hinder sacral ribs.

The radius is a stout bone. All the bones of the shoulder-girdle and pelvis indicate an
animal that was accustomed to bear its heavy body about on land.

One of the vertebra present is the eighth cervical. It resembles closely that of T. radzata.

Hadrianus tumidus sp. nov.

Fig. 480.

The specimen on which this species reposes was obtained in the upper Uinta deposits of
Utah, by the American Museum’s expedition of 1895. Its number is 6076. It consists of
nearly the whole of the left half of the plastron and the peripherals above the bridge. From
the plastron are missing the epiplastron and the entoplastron. ‘The parts present are in their
natural relations, so that some idea may be obtained of the appearance of the shell.

The length of the portion of the plastron present (fig. 480), from the anterior end of the
epiplastron to the extremity of the xiphiplastron, is 533 mm. The whole length of the carapace
could then have been hardly less than 800 mm. The breadth of the half plastron, from the

28 I

TESTUDINID. 3

midline to the lower ends of the peripherals, is about 220 mm. The extreme width of the car-
apace was about 550 mm. From a line joining the axillary and inguinal notches the bridge
ascends at an angle of 30°, altho this may have been greater during life. About 130 mm. beyond
the line mentioned there is an abrupt turn of the carapace upward. This continues, in our
specimen, to the upper margin of the peripherals, a distance of 135 mm. The abrupt turn men-
tioned marks the position of a sharp carina which runs along the side of the shell from the free
border of the carapace in front of the bridge to the free border behind it. Such a carina is seen
in at least some specimens of H. corsonz. The width of the bridge 1s 250 mm.

The hinder half of the plastron was very concave, especially from the inguinal notches
backward. The anterior half was flat. The individual was probably a male.

The bone of the central portions of the plastron is thin, 17 mm. just behind the ento-
plastron, in the midline; g mm. at the suture between the hyoplastrals and hypoplastrals;
and 8 mm.at the anterior end of the xiphiplastrals.
Near the free borders, however, the bone is very
thick, 31 mm. at the anterior end of the epiplas-
tron, 37 mm. at the anterior end of the xiphiplas-
tron. On the epiplastron the bone is beveled off
gradually to a sharp edge. Behind the inguinal
notch the bone is beveled off very abruptly, so
that the beveled portion is nearly perpendicular.
The hinder end of the xiphiplastron is 32 mm.
thick, rough, and with a broad, rounded edge.

No part of the entoplastron is present, but
the sutural border of the epiplastron enables us
to determine something regarding its extent and
form. It had a breadth of 156 mm. at the hinder
ends of the epiplastrals. From a line joining
these it has extended backward about 75 mm.
From this we may infer that its larger portion lay
behind the ends of the epiplastrals. It was not
crost by the humero-pectoral suture. The ante-
rior end of the hyoplastron, where it articulated
with the epiplastron, is 55 mm. wide. The extreme
length of the hyoplastron is 222 mm.; its length
in the midline is 155 mm. The length of the
hypoplastron in the midline is 140 mm.; on the
line joining the axillary and inguinal notches, 173
mm. At the midline the xiphiplastrals measure
1r8 mm. At their anterior ends they are 140 mm.
wide. The notch at the posterior end of the plas-
tron has not exceeded 25 mm. in depth.

The suture between the plastron and the per-
ipheral bones, on the bridge, runs a very sinuous
course, the opposing bones forming broad inter-
digitations 35 mm. long. The fifth and sixth
peripherals are each about 85 mm. wide, fore and aft, and rise about 135 mm. above the turn
of the carapace upward.

The plastral buttresses of this species are rather weak, but are relatively better developt
than in Testudo. They rise to the upper margin of the peripherals. The sulci are deeply
imprest. The humero-pectoral begins just in front of the axillary notch, runs inward and back-
ward for a short distance, then straight across the plastron, just missing the hinder border of
the entoplastron. Behind this sulcus, 55 mm., the pectoro-abdominal sulcus crosses the mid-
line. It is bent slightly forward on each side, then runs outward, backward, and upward to
the marginal suture. The abdominal scutes have great extent. Along the midline they measure
193 mm. The sulcus limiting them posteriorly runs from the midline outward and somewhat
forward, passing 50 mm. in front of the inguinal notch. The femoral scutes join along the

Fic. 480.—Hadrianus tumidus. Plastron,
lacking epiplastron and entoplastron. 5.

No. 2090 A. M. N. H

282 FOSSIL TURTLES OF NORTH AMERICA

midline for the space of 85 mm. ‘The sulcus between these and the anals is directed outward
and backward. Where it crosses the edge of the xiphiplastron there 1s a considerable notch.
The anals have a fore-and-aft extent of about 70 mm. and a breadth of 103 mm. each.

The sulcus between the plastral and the marginal scutes runs above the lower peripheral
suture, as it does in Testudo.

There is a large inguinal scute, but there is no axillary scute, or a very obscure one.

On the bridge are Shice considerable bosses, separated by the sulci in front of and behind
the abdominal scute.

In endeavoring to find characters to distinguish this species from the others that have been
described we miss first the epiplastral lip. From AH. majusculus, of the Wasatch, it differs in
having the bridge longer relatively to the hinder lobe. In the Wasatch species the hinder lobe
forms about 85 per cent. of the length of the bridge; in H. tumrdus, only about 77 per cent.
The pectoral scute of H. majusculus is broader than that of H. tumidus, and the anal notch
is deeper.

From H. corsonz, of the Bridger beds, the Uinta species appears to differ in several respects.
The peripherals over the bridges : are evidently higher, the height in the former species amount-
ing to considerably less than one-half of the width of the bridge, while in the Uinta species the
height i is equal to one-half of the bridge. In H. corson1, from the inguinal buttress a broad
ridge runs backward to the rear of the hinder lobe at the midline. Mesiad of this, the upper
side of the plastron 1s concave, especially next to the ridge. Outside of the ridge the surface 1s
beveled off, near the buttress steeply, but less and less so more posteriorly, until on the pos-
terior outer angle of the xiphiplastron the slope is very gentle. In H. tumidus this ridge is
almost wholly Bhediece and the upper surface of the posterior lobe is convex to near the border,
then pitches off nearly perpendicularly. This condition continues to the notch for the anal
sulcus. The hinder extremity of the xiphiplastron of H. corson: is thinned off to a sharp edge
while in H. turmdus it is thick and the free edge is rounded off.

Hadrianus? schucherti Hay.
Text-fig. 481.

4 dite iv, v; Bibliog. and Cat.

Hadrtanus schuchert, Hay, Proc: U.S: Nat. Mus., XXII, pee p- 2
at. Mus., XXIII, 1900, p. 328.

Foss. Vert. N. A., 1903, p. 450.—ScCHUCHERT, Proc. U.S. N

The present species is assigned provisionally to the genus Hadrranus, altho it belongs
possibly to Testudo. If really a Testudo, it is one of the oldest, if not the oldest of the genus,
coming as it does from the Upper Eocene.

The type and only known specimen belongs to the U. S. National Museum. It was dis-
covered by Prof. Charles Schuchert, then of the U. S. Geological Survey, in the Zeuglodon
beds of the Jackson formation, near Cocoa post-office, in Choctaw County, Alabama. In the
immediate vicinity Professor Schuchert found bones of the mammals Basilosaurus, Dorudon,
and of the snake Pterosphenus schucherti Lucas.

The upper portion of the carapace of this specimen had been eroded away down to the
upper borders of the peripheral bones. We are therefore unable to determine the characters
of the neural and costal bones. Nor are we able to determine whether the supracaudal scute
was single or double.

The total length of the carapace was originally close to 750 mm. Its width is 525mm. As
will be seen from an inspection of fig. 481, the lateral borders of the shell are nearly straight
and parallel with each other. In front of the axillary notch the margins round rapidly into the
anterior border. The shell is quite truncated in front. The hinder border approaches in form
a segment of a circle. Neither the anterior nor the posterior border is to any degree serrated.
The peripherals rise on the sides of the shell to a height of 100 mm. The passage of the lower
surface of the shell to the upper is quite abrupt; but this appears to be due to a considerable
extent to distortion by pressure.

The borders of the carapace over the opening for the hinder limbs are flared gently upward;
over the openings for the forelimbs they are more strongly flared.

The plastron is concave, a condition that indicates a male individual. It has a length of
675 mm. The anterior lobe has a length of 202 mm. and a width of 309 mm. The epiplastral

282

TESTUDINID~. 3

lip is not well differentiated, being narrow, pointed, and not projecting beyond the rim of the
carapace. The extremity is considerably thickened; but the borders are rather acute. The
entoplastron has a width of 150 mm. Its
hinder border can not be exactly traced, but
the form of the bone has apparently been
nearly circular.

The bridge has a width of 281 mm., being
therefore a little more than four-tenths of the
length of the plastron.

The hinder lobe has a length of 202 mm.
Its width is 309 mm. Its dimensions are there-
fore the same as those of the front lobe. The
hinder extremity was notcht, but the angles
on each side of the notch may not have been
so acute and long as shown in the restoration
and the figure.

The arrangement of the scutes is not, so
far as can be determined, greatly different
from that of other Testudinide. The gulars
do not encroach on the entoplastron. The
humero-pectoral sulcus runs straight across
the plastron (not touching the entoplastron )
until it approaches the axillary notches, when
it turns abruptly forward. The pectoral
scutes are very narrow, about 22 mm. at the
midline, but they widen right and left. The
abdominal scutes extend fore and aft a great
distance, about 242 mm., this length being
contained in the length of the plastron two
and a half times. The femoral scutes have
an extent of 56 mm. along the midline. There were evidently inguinal scutes; but no axillary
scutes have been observed. The sulci between the plastral and the marginal scutes at the
bridges appear to have lain on the plastral bones, near the sutures between the plastral and
the peripheral bones.

The figure publisht in the Proceedings of the U.S. National Museum, vol. xx11, plate iy, is
eight forty-hfths the size of the original, instead of one-seventh as stated on the plate. The
diagrammatic figure forming plate v of that publication 1s 19 hundredths the natural size.

Fic. 481.—Hadrianus schuchertt. Plastron.
From type in U.S. N. M.

Genus ACHILEMYS nov.

An imperfectly known genus of the Testudinide. Carapace with recurved hinder periph-
erals. Sulcus between the fifth vertebral scute and the supracaudal crossing, as in Stylemys,
on the last suprapygal. Plastron with a broad, extremely short lip, which is obtuse and which
does not thicken backward on the upper surface as it does in other Testudinide.

Type: Hadrianus allabratus Cope.

Achilemys allabiata (Cope).
Figs. 482-485.

Hadrianus allabiatus, Cort, Proc. Amer. Philos. Soc., xu, 1872, p. 4713 6th Ann. Report U. S. Geol.
Surv. Terrs. (Hayden), 1872 (1873), p. 630; Vert. Tert. Form. West, 1884, p. 140, plate xv, figs
13-15.—Ossorn, Scott, and Speir, Contrib. Mus. Geol., Archzeol. Princeton College, No. 1, 1878,
p. 94.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1903, p- 450; Amer. Geologist, Xxxv, 1905,
P- 333-

The type of the present species belongs to the U. S. National Museum and bears the
number 4054. It consists of the right half of the front lobe of the plastron, 2 anterior periph-
erals, 3 hinder peripherals, a portion of the pygal, and a portion of the last suprapygal. It

384 FOSSIL TURTLES OF NORTH AMERICA.

was obtained by Professor Cope in the neighborhood of Cottonwood Creek, Wyoming, and
comes from the Bridger Eocene beds, the level being that known as B.

Cope’s description of this species is very brief and unsatisfactory, not even doing justice
to the fragmentary materials at his command, yet including statements that imply that he
had more materials than are now accessible. He states that the plastron was concave, yet we
have no evidence that other parts of it were present than the half of the anterior lobe. The
surface of the carapace is said to be without irregularities of surface, yet no neurals or costals
seem to have been secured.

The size of the individual must have been greater than estimated by Cope. He says that
the length was 18 inches, equal to 437 mm. Cope’s fig. 14 of his plate represents the ninth,
tenth, and eleventh peripherals of the right side, and about half of the pygal. The length of
the ninth and tenth taken together amounts to 156 mm. The length of the same two elements
of a specimen of H. corsoni whose carapace has a length of 5g0 mm. is 131 mm. An estimate
based on these dimensions makes it probable that the type of the species had a length of about
626 mm., or about 25 inches.

It is improbable that this species belongs to the genus Hadrianus. Two reasons may be
assigned for this opinion. The first is found in the fact that there is no epiplastral lip, a

485.

Fics. 482-485.—Achilemys allabiatus. X%. Type.

482. Portion of rear of carapace. per. 11, eleventh peripheral; py, pygal; spy, suprapygal.
483. Portion of anterior lobe of plastron. hyo, hyoplastron; ent, entoplastron; eps, epiplastron.
484. Section of ninth peripheral.

485. Section at anterior end of eleventh peripheral.

structure found in the other species of the genus, except possibly in H. tumidus, the only known
specimen of which does not present that region. In Achilemys allabrata this lip is not differ-
entiated even so much as it is in the Emydide.

The second reason is found in the structure of the hinder region of the carapace. With
the other bones of this species at Washington there is a portion of a suprapygal which joins
accurately the eleventh peripheral and the pygal of the type. This is represented in its proper
position in fig. 482. This bone has the position of the third suprapygal of Testudo and of
Fladrianus corsont. In the genera just named the sulcus between the last vertebral scute and
the supracaudal scute Fallows closely the suture between the third suprapygal and the pygal.
In the species being here described the sulcus crosses the suprapygal at some distance above
the suture rereieede to. It is to be noted also that the three peripherals of this region are
traverst by perpendicular sulci from top to free border, showing that the sulcus between the
marginal scutes and the costal scutes ran on or above the sutures between the peripheral and
costal bones. The position of the sulci of this region in our species resembles somewhat that
of Kachuga, as represented by Mr. Boulenger (Cat. Chelonians, p. 53, fig. 16).

The epiplastron (fig. 483) figured by Cope has the anterior end thickened and rounded
in section. More posteriorly this. epiplastron has an acute border. At their symphysis the epi-
plastra have a thickness of 23 mm. ‘The truncated end of the anterior lobe, the rudimentary
lip, has a width of about 125 mm. The scute-covered area on the upper surface is 18 mm.
wide. The bone on this surface does not thin backward as in Testudo and Hadrianus. The
entoplastron had a width of about 170 mm. It was truncate or cordate behind, notwith-

TESTUDINID&. 385

standing Cope’s statement. Its length was about 110 mm. The scutal sulci are very obscure
on this fragment of the plastron, but the gulo-humeral is distinguishable.

An anterior peripheral has the upper surface nearly flat and the free border acute. The
hinder peripherals (fig. 482) are strongly fared upward toward the free border, the ninth most
so (fig. 484), the eleventh less so (fig. 485). The ninth has a width along the free border of
85 mm. and the height was about go mm. in a straight line. All the peripherals have a thick-
ness of about 18 mm. The pygal is 21 mm. thick.

Cope states that the sulci are deeply imprest. Those of the carapace are distinct enough,
but those of the front of the carapace are very narrow, shallow, and indistinct. The gulo-
humeral sulcus is very narrow and shallow and distinguisht with difficulty.

Osborn, Scott, and Speir’s identification of this species is based entirely on two ungual
phalanges collected by them in the Bridger beds.

Genus STYLEMYS Leidy.

Testudinide with the plastron joined to the carapace by sutures, and with inguinal
buttresses which pass a short distance within the carapace between the fifth and sixth costal
plates. No hinge in either plastron or carapace. Of the neural plates, those behind the third
are hexagonal and have the antero-lateral sides much the shortest. The second and third may
be hexagonal; or the second may be octagonal and the third tetragonal. ‘Two or three supra-
pygals; the penultimate, bifurcate. Rike at distal ends of otal plates entering pits in
peripherals of bridges. Costal plates with opposite ends differing much or little in width.
Fpiplastral lip not projecting beyond the general contour of the anterior lobe of plastron.
Entoplastron in front of the humero-pectoral sulcus. Supracaudal scute single. Skull and
limbs, so far as known, like those of Gopherus.

Type: Stylemys nebrascensts Leidy.

The relationship of this genus has been variously regarded. It was establisht by Leidy,
the name being given through a misconception that the plastral buttresses were separate
bones. On the: discovery of his error Dr. Leidy employed for a while the name Testudo for
the species of this genus, while in his latest work on the genus (Contrib. Ext. Fauna West.
Terrs. ) he vacillated between Testudo and Stylemys This: procedure indicates that he recog-
nized ne close relationships between the species with which he was dealing, S. Be ene
and the species of Testudo. Professor Cope recognized the validity of fhe genus. While
regarding the Emydide and the Testudinidz as forming distinct families, he referred Stylemys
to the former, doubtless supposing that the digits possest three phalanges each.

It is the opinion of the present writer that the genus in question belongs to the Testudinide.

Unfortunately, we are even yet not thoroly acquainted with the dstcolos ey of the species
of Stylemys. Probably thousands of shells of 8. nebrascensis have been observed, yet we know
of only one skull that has been found actually associated with its shell, no undisturbed foot
likewise associated, and no cervical vertebre ‘whatever. In the collection at Princeton Uni-
versity there is the greater portion of a skull which is here figured as belonging to S. nebras-
ce bigs: but it did not accompany a shell. In the Carnegie Museum at Pittsburg is a shell of
S. nebrascensis accompanied by the skull. In the American Museum there are various bones
_ the internal skeleton about which there need be no doubt. All the indications furnisht by
these remains point to a close relationship with our living land-tortoises. The skull has the
structure of that of Gopherus (Xerobates). It seems quite certain that none of the digits
possest more than two phalanges, but the proof is not complete. The scapula, the coracoid,
the humerus, the forearm bones, the pelvis, and the bones of the hinder limbs agree with the
corresponding bones of Testudo and Gopherus. A humerus of S. nebrascensis (fig. 492) shows
that the radial and ulnar processes of the proximal end are twisted toward each other as in
T estudo, and in a way entirely different from what we see in the Emydide. The form and
structure of the shell agree rather with that of T estudo than with that of the Emydidz. It is
true that in the type species, S. nebrascensis, the neural bones and the costals have not under-
gone the modifications which characterize those of Testudo; but even here we meet with the
beginnings of these modifications; and in the John Day species they become unmistakable.
Here the second neural is octagonal, the third is tetragonal, and the costals have become
wedge-shaped. A peculiarity of the hinder region of the carapace, seen rarely in the Emydide,

25

386 FOSSIL TURTLES OF NORTH AMERICA.

presents itself in Stylemys, viz., a bifurcate penultimate suprapygal. The nearest approach to
this is seen in Kac huga ( Boulenger, Cat. Chelonians, p. 53, fig. 16).

The epiplastral lip of Stylemys does not project forward beyond the general border of the
plastron, as it does in most of the species of Testudo; yet the epiplastral bones are thickened
anteriorly on the upper side in a manner similar to that found in Testudo.

The geological duration of the genus, so far as known, is from the lower Oreodon beds of
the White River deposits to the John Day Miocene. The writer has not been able to find any
records of the finding of specimens of the genus in the Titanotherium beds. It is remarkable
that the genus Hadrianus should disappear in the Uinta deposits, while Stylemys and T estudo
should appear immediately afterwards in the White River beds.

The writer has elsewhere (Amer. Geologist, XXXV, 1905, p. 342) exprest the opinion that
the living North American species included under the name Gopherus (Xerobates Agassiz)
have descended, not from Hadrianus, but rather trom Stylemys. This opinion is based
principally on the fact that the species of both groups have a longitudinal ridge along the
midline of the triturating surface of the upper jaw. This idea requires the confirmation to be
obtained only in the discov ery of more complete skeletons.

ANALYSIS OF SPECIES OF STYLEMYS.

1. Shell nearly as broad aslong. Seldom an octagonal neural present. Pectoral scute, on
midline, three-tenths width of abdominals; free borders of hinder peripherals acute... nebrascensrs
2. Shell nearly as broad as long. Second neural octagonal, third quadrangular; pectoral

~

scutes one-fifth width of abdominals; hinder peripherals obtuse . . ae capax
3. Shell more elongate; neurals as in capax; peripherals more as in nebrascens:s. cons pecta
4. Not wellknown. Third neural 4-sided; anterior lobe truncated in front calaverensis

Stylemys nebrascensis Leidy.
Plate 59, figs. 2-4; plate 62, figs. 1, 2; text-figs. 486-496.

Stylemys nebrascensis, Lewy, Proc. Acad. Nat. Sci. Phila., v, 1851, p. 172; Ann. Rept. U. S. Geol. Surv.
Wyoming, ete., 1870 (1871), p. 366; Contrib. Ext. Fauna West. Terrs., 1873, p. 224.—Core, Trans.
Amer. Philos. Soc., X1v, p. 124, plate vii, figs. 10-12; Vert. Tert. Form. West, 1884, p. 769; Contrib.
Canad. Palont., 11, 18g1, p. 5 —LypeEKKER, Proc. Zool. Soc. Lond., 1889, p. 94.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 450; Ann. Carnegie Mus., 1v, 1906 (1907), p. 19, figs. g-11.

Emys hemispherica, Leipy, Proc. Acad. Nat. Sci. Phila., v, 1851, p. 173; 6th Ann. Rept. Smithson.
Inst., 1851 (1852), p. 65.

Testudo lata, Leipy, Proc. Acad. Nat. Sci. Phila., v, 1851, p. 173; 6th Ann. Rept. Smithson. Inst. 1851
(1852), p. 65; Owen’s Rept. on Geol. Surv. Wis., lowa, and Minn., 1852, p. 572; Ancient Fauna
Nebraska, in Smithson. Contrib. Knowl., v1, 1854, art. vii, pp. 110, 115, plate xxiii, figs. 1, 2, plate
xxiv, fg. 1.—Maack, Paleontogr., xvii, 1869, p. 246.

Emys owent, Leipy, Proc. Acad. Nat. Sci. Phila., v, 1851, p. 327.

Emys culbertsonit, Leipy, Proc. Acad. Nat. Sci. Phila., v1, 1852, p.

Testudo hems pherica, Letpy, Proc. Acad. Nat. Sci. Phila. 1852, v1, p- ee Owens’ Rept. on Geol. Surv.
Wis., lowa, and Minn., 1852, p- 570, plate xu, figs. 1, 2; ApecEE Fauna Neb. 1854, pp. 105, 115,
plate xx, figs. 1, 2, plate xxiv, fig. 3.—WunckLer, Arch. Mus. Teyler, 11, 1869, p. 146, plates
XXXI-XXxI1.—Maack, Paleontogr., xvi, 1869, p. 245.

Testudo nebrascensis, Leiwy, Proc. Acad. Nat. Sci. Phila., v1, 1852, p. 59; Owen’s Rept. on Geol. Surv.
Wis., lowa, and Minn., 1852, p. 567, plate xiia, figs. 1, 2; Ancient Fauna Neb., pp. 103, 115, plate
xix, figs. 1-3; Jour. Acad. Nat. Sci. Phila., (2), vit, 1869, p. 26 (Testudo, or Stylemys neb.); Contrib.
Ext. Fauna West. Terrs., 1873, p. 339, plate xix, figs. 7, 9, 1o—Maack, Paleontogr., xvi, 1869,
p. 245—Marsu, Amer. Jour. Sci., (2), L, 1870, p. 292.—Zitrer, K. A., Handbuch Paleont., 11,
1880, P- 54°, hg. 5or.

Testudo owent, Leipy, Proc. Acad. Nat. Sci. Phila., v1, 1852, p. 59; Owen’s Rept. on Geol. Surv.
Wis., lowa, and Minn., 1852, p. 568, plate xii, figs. 3, 4; Ancient Fauna Neb., 1854, pp. 106, 115,
plate xxi, figs. 1, 2, plate xxiv, fig. 4—Maack, Paleontogr., xvii, 1869, p. 245.

Testudo culbertsoni1, Letpy, Proc. Acad. Nat. Sci. Phila. ae 1852, p. 59; Owen’s Rept. on Geol. Surv.
Wis., lowa, and Minn., 1852, pp. 569, plate xu, figs. 1,2; Ancient Fauna Neb., 1854, pp. 108, 115,
plate xxu, figs., 1, 2, plate xxiv, fig. 2—Maack, rene xvul, 1869, p. 246.—HABERLANDT,
Jahrb. k. k. Reichsanst., xxv, 1876, p. 243.

Emys nebrascensis, Letpy, 6th Ann. Rept. Smithson. Inst., 1851 (1852), p. 65.

Emys lata, Lerpy, 6th Ann. Rept. Smithson. Inst., 1851 (1852), p. 65

Stylemys culbertsonit, Cope, Trans. Amer. Philos. Soc., x1v, 1869, p. 124.

TESTUDINIDZ. 387

This species is by far the most abundant fossil turtle found in any of the geological for-
mations in North America. Many years ago Dr. Leidy stated that he had seen hundreds of
the shells; and since that time many in eodidon have been collected and deposited in the
various museums. Some individuals attained a large size. Most of the specimens seen in
museums are of small or moderate size, for the large : shells have not usually been regarded by
collectors as worth the trouble and expense of transporting. Statements made by reliable
collectors are to the effect that individuals are sometimes met with which have had a length of
3 feet (890 mm.) The type of Leidy’s Testudo lata had a plastron 21 inches (about 530 mm.)
long. The largest shell in the American Museum of Natural History is 510 mm. long, 375 mm.
wide, and 265. mm. high.

The species was described in early days by Leidy under several specific names, which are
mentioned in the synonymy. These so-called species were based in some cases on purely
individual characters; in others, on modifications of form due to distortion. Dr. Leidy him-
self was the first to correct these errors. The specimens from which were drawn the following
figures publisht by Leidy in vol. vi of the Smithsonian Contributions to Knowledge are in ite
U. S. National Museum: Plate xix, figs. 1, 2, 3 (Testudo nebrascensis); plate xx, figs. 1, 2
(T. hemispherica); plate xxi, figs. 1, 2 (7. owenz). The specimens from which were obtained
the figures of J. /ata, op. cit., plate xxii, plate xxiv, fig. 1, are in the Philadelphia Academy.

In form this tortoise was broad and rather high and vaulted. The height and convexity
appear to have increast with age. Often the rather low and flattened form is due to pressure
exerted during fossilization. Nevertheless, among specimens of the same size there are
differences in the form and height of the shell which must have existed during the life of the
animals.

The width of the shell forms about $5 per cent. of the total length. In outline the carapace
is truncated in front, or even a little concave; behind, it is broadly rounded. The peripherals
over the bridges are nearly or quite perpendicular; those over the limbs are slightly flared;
those in front slope dow nward and forward, or flare slightly upward; the pygal is nearly
perpendicular. ‘The free edges of the anterior and posterior peripherals, the nuchal, and the
pygal are acute. The Fedtale excepting the first, which is oval, are almost always hexagonal,
with the two shortest sides directed forward, Occasionally, as in the type of Leidy’ See
culbertsoni1, the second neural is octagonal, the third quadrangular ( (Ancient Fauna Neb.,
plate xxi, fig. 1). There are usually 2 ‘suprapygals, the larger anterior of which is bifurcated,
as in Testudo; the smaller posterior one is rhombic, with its lower border fitting in a notch in the
upper border of the pygal. In Leidy’s type just referred to there is an accessory plate in front
of the first suprapygal; and the same condition is occasionally met with in other specimens.

The costal plates are modified somewhat as they are in the genus Testudo. The second,
fourth, and sixth are somewhat widened distally and narrowed proximally, while the third
and fifth are narrowed at the distal end and widened at the proximal. ‘The degree of this
differentiation varies somewhat with individuals, and in general 1s not so much developt as in
S. conspecta and S. capax. In uncrusht examples of the species the bridge peripherals rise
nearly half the height of the shell. In a specimen whose length of carapace is 260 mm. the
height of these peripherals i is 58 mm. The suture between the costals and the peripherals is a
very loose one, as in Testudo.

The sulci bounding the carapacial scutes are narrow, but rather deeply imprest. The
nuchal scute is very narrow. The first vertebral is wider by one-half than the second. The
fourth is somewhat narrower than the second and the third; while the fifth is nearly as wide
as the first. On the bridge peripherals the sulci run obliquely downward and forw ard. The
sulci between the costal scutes and the marginals follow closely the sutures between the
costal and peripheral bones. On the hinder pygal the sulcus runs slightly above the suture.

The anterior lip of the plastron projects little, if any, beyond the general curve of the
anterior lobe. The outline of the lip is rounded or repand, and the edge i is rather acute.
Superiorly the lip thickens backward for a distance about equal to the width of a gular scute,
and then ceases abruptly, but there is no excavation behind it. The entoplastron is narrow
in front and broad behind. The width of the bridges is not quite one-half the length of the
plastron. The lobes are so wide that space is left only for the movement of the limbs and for
the tail, There is a notch in the hinder border of the plastron, and the apices of the xiphi-

388 FOSSIL TURTLES OF NORTH AMERICA.

plastra on each side of this are rounded. The bone of the plastron is relatively thick. In the
case of a specimen whose plastron is 210 mm. long the thickness of the hyoplastron is 16 mm.;
that of the hypoplastron half-way between the median line and the inguinal notch is 14 mm.
Proceeding backward from the inguinal notch near the free border there is a low wall from the
summit of which the bone slopes downward and outward. Farther backward the height of
the wall diminishes rapidly and the slope is less steep, so that on the apices of the xiphiplastra
the sloping face looks nearly upward. From the summit of the wall the surface slopes very
slowly toward the midline.

The gular scutes overlap slightly the entoplastron. The humero-pectoral sulcus crosses
the midline just behind the entoplastron. The pectoral scutes are rather narrow at the mid-

/ een ee —{~——
Nad aa a a
j eee
Pn at

mes

a f ‘ \
: i \
| 487
Ot —_— ae end’

rer) St eodleedanee Sictehonn
i 4
s 3
} ?
/ :
| :
a

coe

Fics. 486 AND 487.—Stylemys nebrascensts. X
486. Carapace. 487. Plastron.

line. The abdominals are the widest of the plastral scutes. At the midline the femorals are
about as wide as the pectorals. The anals occupy somewhat more of the midline than do the
femorals. Small axillary and inguinal scutes are present.

Figs. 1 and 2 of plate 62 furnish illustrations of the shell of a specimen of the species, No.
1433 of the American Museum of Natural History. The figures are half the natural size.
Text-figs. 486 and 487 are derived from the same specimen.

It is remarkable that, notwithstanding the great number of individuals of this species which
have been found, few skulls have hitherto been discovered. Leidy, writing many years ago,
stated that he had seen hundreds of shells but no skull. The one here described as probably
belonging to this species belongs to Princeton University.

‘This: specimen (plate 59, figs. 2, 3) was collected by Mr. J. W. Gidley, now of the U. S.
National Museum, in the year 1896. It was found in the Oreodon beds of the Hat Creek
Basin, near Prairie Dog Creek, Nebraska. It was not accompanied by any other parts; but
in the White River deposits of that region Stylemys nebrascensis is abundant; and no other
related species, except one specimen of Testudo brontops, of the Titanotherium beds and 7.
thomsoni of the lower Oreodon beds has been found in the White River Oligocene; so that the
probability is very great that the skull belongs to this species. This probability is confirmed
by the skull next to be described.

Unfortunately, the Princeton skull is not complete. The hinder segment is missing, as
well as the quadrates. There is likewise no lower jaw present, and there are some minor
deficiencies.

TESTUDINID&. 389

In general the structure of the skull resembles that of the genus Gopherus, and therefore
in general that of Testudo. As regards its size, in case the ratio of the portion behind the
orbits to that from the postfrontal bones to the tip of the snout was the same as in the skull of
either Gopherus polyphemus or of Testudo tabulata, the whole length from snout to occipital
condyle must have been about 75 mm., and the breadth at the quadrates about 61 mm. The
orbits are large, about 20 mm., hardly smaller proportionately than they are in the Testudo
mentioned. The interorbital space is 15 mm. wide. The upper surface of the skull, from the
nostrils to near the hinder border of the frontals, is gently convex. The parietals are more
convex both longitudinally and transversely.

The sides of the face just behind the nostrils were nearly perpendicular. The nasal
opening is nearly quadrate, and was 16 mm. wide and about 10 mm. high. The cutting-
edges of the maxillaries make about the same angle with each other that they do in T. tabulata
and G. polyphemus. There is a broad notch in the cutting-edge at the premaxillary symphysis;
and behind this on each side there is an indication of a tooth. The masticatory surfaces of
the upper jaws resemble in breadth those of the genus Gopherus. Along the middle of each

492.

489. 490.

Fics. 488—492.—Stylemys nebrascensis. Skull and humerus.

488. Upper view of skull. 1. No. 1571 Carnegie Museum.
489. Lower view of same. 1.

490. Side view of same. X1.

491. Right humerus, dorsal view. 3. No. 700 A.M.N.H.
492. Right humerus, proximal end. 2.

surface there is a tootht ridge which runs parallel with the cutting-edge. In front, a longi-
tudinal ridge runs backward from the symphysis, as in G. polyphemus, a character which has
led to the separation of the North American species of Testudo, to form the genus Gopherus.
In Stylemys a less elevated ridge is developt on the inner border of the maxillary. The structure
of the upper jaw 1s like that of Gopherus polyphemus, except that in Stylemys the masticatory
ridges do not join the longitudinal ridge.

As in Testudo and Gopherus, the palate is archt upward high above the level of the
masticatory surfaces; and there is a sharp ridge which, starting on the vomer, is continued
backward to the hinder end of the latter bone and on the conjoined edges of the pterygoids.
The width of the vomer, where it articulates with the premaxillaries and the maxillaries, is
considerable, as it is also in G. polyphemus. In T. tabulata the vomer is narrow anteriorly and
articulates only slightly with the maxillanes.

The vaulted roof of the mouth continues backward as far as the bones of the skull are
preserved, and judging from TJ estudo, to a line joining the front borders of the articular ends
of the quadrates. In the specimen the vaulted roof has been forced upward and broken across
the middle, and a portion of it is missing; but the hinder end of the vomer is present, and
extended backward about 25 mm. from the anterior end. ‘The palatines extend backward
as far as the hinder end of the vomer. The nasopalatine and posterior palatine foramina haye
the same positions as in Gopherus. The former is rather small.

The postfrontal and jugal bones are missing; as are also the prootics, squamosals, and
quadrates.

390 FOSSIL TURTLES OF NORTH AMERICA.

No. 1571 of the Carnegie Museum, Pittsburg, furnishes a nearly complete skull of a small
individual (text-fgs. 488, 489, 490). This etal is accompanied by enough of the shell to
establish clearly the species. The remains were collected in 1905, by Mr. ‘Earl Douglass, of
the Carnegie Museum, in the Oreodon beds of the Little Badlands, southwest of Dickiacon’
Stark County, North Dakota. So far as the parts presented by this skull and that belonging
to Princeton University are common, they agree closely. The length of the skull, from the
snout to the occipital condyle, is 38 mm.; the width at the qu uadrates, 30 mm. The hinder
border of the postorbital bar is equally distant from the occipital condyle and the snout. The
bar just mentioned is 5 mm. wide; the zygomatic bar 1s slightly wider. The interorbital
space is 10.5 mm. wide. The antero-posterior diameter of the orbit is 11 mm.; the vertical,
gmm. The longest diameter of the auditory chamber is g mm. The pterygoid region is 10
mm. wide. ayn pedicel of the quadrate is unusually narrow, only 4 mm. from side to side.

The palate is deeply excavated, and a low sharp ridge runs along the middle of it. Most
of the lower jaw is firmly held in its natural position, but the remoy Al of the tip exposes a low
median ridge along the palatal part of the symphysis of the premaxilla. It is evident therefore
that the larger skal described above is correctly identified.

Few satisfactory specimens of the bones constituting the shoulder-girdle of adult individ-
uals have been secured. In the American Museum these bones belonging to a young animal

(No. 699, from South Dakota) are present. The scapula is slender and makes an angle of about
120 degrees with the procoracoid process. The coracoid broadens greatly toward the free end.

No figure of the humerus has hitherto been publisht. Professor Cope (Ext. Bat., Rept,
Aves N. A., 1869, plate vil, figs. 12, 12a) presents a figure which is explained as being that of
the humerus of this species; but the figure is that of the femur. The humerus of the specimen
mentioned above, No. 699 of the American Museum, shows that the bone had nearly the form
that it has in G. polyphemus, but it is bent slightly more than in the species just named. Other
larger but imperfect specimens confirm this ene on Fig. 491 is taken from one of these,
No. 7oo, American Museum, but a portion of the shaft is missing. This specimen was found
with the shell. Figure 492 1s a view taken from the proximal end, to show the head and the
radial and ulnar processes. The ulnar process does not rise so much above the head as in
Testudo radiata. The angle between the processes is reduced as in J estudo and is thus different
from the condition found in the Emydidaw. The ectepicondylar foramen is close to the distal
end of the bone.

The Amerian Museum of Natural History possesses the left forearm and some foot bones
of a large specimen believed to be of this species, No. 702, collected by the museum’s expedition
of 1892, i in South Dakota. A drawing (fig. 493) 1s presented of the ulna, radius, intermedium,
radiale, the ulnare, the fourth distal carpal, and another (fg. 494) of a digit, including one claw
phalange. The limb is stouter than it 1s in any of the species of 7 estudo at hand, but resembles
them closely. The proximal end of the ulna is broad, and forms a prominent olecranon process.
The distal ends of both radius and ulna are flat for articulation with the carpals. The radius
forms a prominent styloid process. The terminal phalanges are much larger relatively than
they are 1n most species of T estudo, but approach nearest those of Gopherus polyphemus. They
differ from the latter in not being so broad and sharp-edged. From the materials at hand it

can not be determined whether eer were two or three phalanges i in the median toes; but no
elongate phalanges are present.

There are at hand the ilium and a portion of the pubis of a specimen, No. 1301, from Old
Woman's Creek, Wyoming (fig. 495). On comparison with the corresponding bones of
Testudo vaga, no differences of importance are observed, except that the flat process extending
backward from the upper end of the ihum is directed slightly inward, instead of outw oat
Cope furnisht a figure of a small portion of the pelvis (Ext. Batrach, Rept., Aves N. A., plate
vil, fig. 11).

The femur ts like that of Testudo vaga, except that the pit between the trochanters is not
so deep. Cope’s figure of this bone has been referred to in the description of the humerus.
No. 1301, A. M. N. H., furnishes this bone from the left side (fig. 496). It is shown two-thirds
the size of nature in fg. 496. It resembles closely the corresponding bone of Gopherus pol y-
phemus but the lower articular surface is more deeply grooved and there is a distinct and
sharp ridge separating the tibial from the fbular surface.

TESTUDINID&. 391

The tibia is a stout bone, whose form may be learned from figure 497, which represents the
left tibia of No. 1301, just mentioned. It is a much stouter bone chan is the corresponding bone
in Gopherus polyphemus. Its length is seven-tenths that of the femur, whereas in G. poly-
phemus the tibia is eight-tenths the length of the femur.

The lower end of the fibula is quite as broad as that of the tibia. Professor Cope figured
one of the metatarsals (Ext. Batrach., Rept., Aves N. A., plate vii, fig. 10).

In a collection of fossils, including some vertebrates purchased by the American Museum
of Natural History from the late James Hall, there are several eggs which are regarded as
those of S. nebrascensis. This identification rests on the facts that these eggs were collected in
the White River deposits of Dakota, in which great numbers of this species occur and a few
other species of tortoise and that they agree closely in size and form a of Gopherus
polyphemus, as represented by Agassiz’ s figure (Contrib. Nat. Hist. U. 1, plate vu, figs.
28, 29). These eggs appear to have been globular, altho now shorter ee one axis, a gontraon
doubtless due to pressure. The diameter ‘along all the axes, except the shorter, is 47 mm.; along
the shorter, 43 mm. Fig. 4, plate 59, represents one of these eggs four-fifths the natural size.

The eggs of G. polyphemus figured by Agassiz have diameters varying from 40 mm. to
45 mm., the axes of the same egg being, in some cases, unequal.

495.
Fics. 493-497.—Stylemys nebrascensts.

493. Left ulna, radius, and three carpal bones; palmar surface x $. No. 702
A.M.N.H.. it,intermedian; rad,radius; u/, ulna; ne ulnz ire.

494. Digit, dorsal surface. 1. No. 702 A.M. N.H.

495. Pelvis, left side. 4. No.1301 A.M.N.H. ¢/,ilium; pub, pubis.

496. Left femur, tibial border. * %. No.1301 A.M.N.H.
2. No. 1301 A. M.N. H.

497. Left tibia, dorsal surface.

No. 1435 A. M. N. H. is a specimen of a very young turtle of this species which was col-
lected by one of the American Museum’s expeditions to South Dakota. The shell is nearly
complete, but 1s somewhat deprest by the weight of the overlying rocks. The total length
was near 75 mm., the breadth, 70 mm. Alghor the bones are loosely connected, there are no
fontanels. “The plastral lip is relatively broad, and in the middle of each lateral half there is a
notch. The free borders of the carapace have been slightly notcht and mucronated; at least,
some mucros are seen on the hinder peripherals.

So far as is known to the writer, no specimens of this species have yet been found in the
lowermost division of the Oligocene, the Titanotherium beds. They are most abundant in
the Oreodon beds, but occur in the Protoceras beds also. The species is extremely abundant
in South Dakota and is found also in Nebraska, Colorado, and Wyoming. In the Cope col-
lection in the American Museum are specimens that were collected on Old Woman’s Creek,
Wyoming, by J. C. Isaac, in 1877. Other specimens were obtained in the Oreodon beds of
Logan County, Colorado, by one of the expeditions from the American Museum of Natural
History in 1808.

392 FOSSIL TURTLES OF NORTH AMERICA.

Stylemys oregonensis Leidy.

Stylemys oregonensis, Letpy, Proc. Acad. Nat. Sci. Phila. 1871, p: 248.—Cope, Bull. U. S. Geol. Sury.
Terrs., v, 1879, p- 55- ay Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451-
Testudo oregonensis, LEIDy, Contrib. Ext. Vert. Fauna West. Taya! 18, pp. 226, 340, plate xv, fig. 10.

In the year 1871, as cited above, Dr. Leidy proposed the name Stylemys oregonensis for
a species of turtle whose former existence he inferred from a single neural plate, supposed then
to be the eighth, sent to him from the John Day deposits of Oregon, the more exact locality
being given as Crooked River. In the later publication cited ( (1873) the specimen is figured and
briefly rdescubed: being here regarded as the third neural. On page 340 of this work the sus-
picion is exprest that che —. is identical with that from the White River deposits, Stylemys
nebrascensis. Professor E. D. Cope possest in his collection a number of well- preserved
specimens of a turtle from che John Day River region; and these he regarded as identical with
that described by Dr. Leidy and with S. nebrascensis. He notes various differences, but he did
not find them to be constant.

Whatever Leidy’s type neural may be it is not the third neural of any known Oregon
species of Stylemys, his type being hexagonal, that of the John Day species of Stylemys being
quadrangular. It is more probably the fifth neural, but not with any certainty that of Stylemys
If a Stylemys, it may belong to either or neither of the two species recognized below by the
present writer.

Stylemys capax sp. nov.

Plates 60, 61; text-figs. 498, 499.

Stylemys nebrascensts, in part, Cope, Vert. Tert. Form. West, 1884, p. 770, “* No. 2. a

The specimen which furnishes the description of this supposed new species was collected
for Professor Cope from the John Day beds of Oregon. The exact locality is said to have been
the “Cove,” in the region of the junction of the North Fork and South Fork of the John
Day River, in the western part of Grant County. The level is doubtless the Middle John Day
or the Diceratherium beds. This author regarded this individual, as well as the other John
Day specimens, as identical with S. BS from the White River deposits. A brief
description and some measurements of this individual were furnisht by Cope as cited above.

The specimen now bears the American Museum’s catalog number, 1357.

In form this species is of moderate width and height, and both the anterior and the pos-
terior borders are broadly rounded. The upper surface is convex in all directions. The
peripherals over the limbs are little, if any, flared. The anterior lobe of the plastron is long and
projects somewhat beyond the carapace. The hinder lobe is deeply notcht.

The length of the carapace (plate 60; text- -hg. 498), taken in

Width “etal 22 straight tne. is 455 mm.; its greatest width 1s 360 mm. The

Costal. upper end. lowerend.. nuchal resembles that of S. conspecta. The neurals differ from
—————'— : those of the species just named in being somewhat broader in

1 60 - proportion to their length. There are not so great differences
2 33 68 among the costals as regards their widths as in S. cons pecta; but
=) fo)
4 20 é a5 = wae A 7
; ef ae this condition may be due to individual variation. The table
44 38 herewith gives the widths of each of the costals at its upper and
; : : 8 : : PP
6 = 53 lower ends, excepting the first and the eighth.
2 42 i a : :
4 : The peripherals are remarkable for their thickness and the
8 20 54 P P

obtuseness of their free borders, being in these respects quite
unlike those of S. conspecta. The second peripheral is 35 mm.
thick, measured on the sulcus between the first and second dermal scutes. The border is obtuse,
with only a suggestion of an edge. In the type of S. conspecta, with shell nearly as long
(415 mm.), the second peripheral is only 25 mm. thick, and it comes down to an acute edge.
The hinder peripherals have a very obtuse border, nearly resembling the border of the fleshy
part of one’s hand. The thickness of most of these hinder peripherals i is 35 mm. The cor-
responding ones of 8. conspecta are 25 mm. thick and are sharp-edged.

The total length of the plastron (plate 61; text-fig. 499) reaches 415 mm. The anterior
lobe is 147 mm. long and 215 mm. wide at the base. The lip extends beyond the border of the

|

TESTUDINIDZ.

carapace about 25 mm. Its anterior extremity is broad and rounded. The distance between
the points where the gular sulci cross the free border is 117 mm. The greatest thickness of the
lobe, at the base of the lip, is 30 mm. There is a slight excavation at the base of the lip on the
upper surtace. The edges of the anterior lobe are subacute.

The posterior lobe has a length of 120 mm. and a width of 215 mm. at the base. The

thickness of the border of the hypoplastron just behind the inguinal notch is 37 mm.; whereas

in S. conspecta it is only 23 mm. The notch in the rear of this lobe has a depth of 25 mm.

a ae | |
ee ‘ :
ate ell \
‘ Fas - fi ane Sia Ss p |
i | ) |
f
i 5 ~“ 4 2 |
; Pd |
eee | |
pl raen oe a LS
- { é \ | Z 7
: aie a ae |
' S [
poe caine ~~ i Z ee < - |
a] { = | |
498. |

> iN 490.

a OT
raat

——
ees
\
t
om
|
{
~—,

} dee
\
J
~
\
i

Fics. 498 AND 499.—Stylemys capax. Carapace and plastron of type. +. No. 1357 A. M.N.H.

498. Carapace. 499. Plastron.

The form and proportions of the scutes, upper and lower, do not differ in any important
way from those of S. conspecta. ‘The humero-pectoral sulcus falls at a considerable distance
behind the border of the entoplastron, but this may be only an individual peculiarity.

This species is remarkable for the thickness of the peripheral and plastral bones and for
the obtuseness of the free borders of the anterior and posterior peripherals. The width also is
proportionately greater than that of S. cons pecta, being only a little less than 80 per cent. of the

length of the carapace.
Stylemys conspecta sp. nov.

\ Plate 64, figs. 1, 2; text-figs. 500, Sor.

1884, p. 769.

Stylemys nebrascensis, in part, Copr, Vert. Tert. Form. West.,

The type of this species is a large and fine shell which belongs to the Cope collection and
is now in the American Museum, bearing the number 1358. It was collected in 1878, by Mr.
Charles H. Sternberg, and appears to have been found near the junction of North Fork and
South Fork of the John Day River, in Grant County, Oregon. Its level is supposed to be the
middle beds of the John Day formation, the Wicemehedim beds of Marsh.

394 FOSSIL TURTLES OF NORTH AMERICA.

Cope regarded these turtles as belonging to Stylemys nebrascensis, the common species of
the White Rives beds of South Dakota. A study of these shells and a careful comparison of
them with the South Dakota form has convinced the writer that they are specifically different
and, moreover, belong to two distinct species, one of which 1s the present, the other S. capax.

The only injury that the type specimen suffered during fossilization is a slight lateral
compression and a moderate thrusting of the plastron upward toward the carapace. The total
length of the carapace (plate 64, fg. 1; text-fg. 500) in a straight line is 415 mm.; the width
of the shell is 215 mm.; the present height is 170 mm. ‘The original width may have been as
much as 300 mm.; the height as much as 180 mm. These estimates would make the width of
the shell about 72 per cent. of the length. The carapace is high and convex both longitudinally
and transversely. Over the bridges the sides were perpendicular or nearly so. There was
little or no flare to the anterior and posterior peripherals. In outline, both the front and
hinder ends are broadly rounded. Where the sulci crost the free border the latter is mucronated.
The nuchal bone is 65 mm. wide along the free border, posteriorly expanding to g5 mm.
The first neural is elongated and oval. ihe second is octagonal; the third is nearly square;
the others, hexagonal and mostly with the shorter sides in on The anterior py gal i is bifur-
cated. The one behind it is four-sided, its hinder border fitting in a notch in the pygal. The
latter bone is somewhat incurved, and is 51 mm. wide and 50 mm. long on the midline.

The costal plates are alternately wide and narrow, having
nearly as high a degree of differentiation as those of the genus
Testudo. The accompanying table presents the widths of the

Costal. Upper end. Lower end.

2 30 68 upper and the lower ends.

3 a oe The first and second peripherals have a width of 60 mm.
4 35 72 5 : = <

5 38 22 along the free border; their extent backward from this border
: i. - is 57 mm. The eighth is 70 mm. high and 47 mm. wide. All
/ ml 4

the free peripherals, as well as the nuchal and the pygal, come
down to an acute free edge. An obscure carina crosses the
bridge peripherals from the free border of the anterior to the free border of the posterior
peripheral.

The nuchal scute is 27 mm. long and 16 mm. wide. The first vertebral is 126 mm. wide
in front. The second and third are about 83 mm. wide; the fourth, 72 mm.; the fifth, 110 mm.
wide posteriorly. On the anterior peripherals the sulci between the marginal scutes and the
costals fall considerably below the sutures between the peripheral and costal bones. On the
sides and posteriorly the sulci are little below the sutures; on the posterior suprapygal, above
the suture.

The plastron (plate 64, fig. 2; text-fig. 501) has a total length of 360 mm. Its general
form is as in S. nebrascensis. The anterior lobe has a length of 120 mm. and a width of 166
mm. at the base. It did not project beyond the front of the carapace. The front of the lip
falls within the general curve of the lobe. The lower surface of the lip 1s flat, while the upper
surface curves down to meet it. In §. nebrascensrs the upper and the lower surfaces are about
equally convex. The entoplastron has the form that it has in S. nebrascensis. The bridge
has a width of 150 mm.

The posterior lobe is 105 mm. long and 180 mm. wide at the base. The notch in the
posterior border is somewhat larger than is usual in S. nebrascensis. As to the thickness of the
bone, the sloping lateral face behind the inguinal notch, the free border more posteriorly, and
the form and proportions of the various scutes, the lobe presents nothing to distinguish it
especially from the White River species.

Another specimen belonging to the Cope collection, | 359, presents some differences
from the shell just described. The length is 255 mm., the or. 177mm. The front border
is slightly concave in outline. The neurals are nearly as wide as those of the larger specimen
just described. The first suprapygal is pentagonal, not bifurcated. The second is 23 mm.
high and 56 mm. wide, and appears to include within itself the limbs of the usually bifurcate
first suprapygal. There is a rather sharp carina along the sides above the bridge. The
anterior vertebral scute is hardly as wide as are the second and the third; while the fifth is but
little wider than those just mentioned.

T C

TESTUDINID. 395

No. 1354 of the Cope collection has a length of 219 mm. and a width of 160 mm. Its
anterior border is concave, the neurals are of moderate width, the pygal is bifurcate, the
peripherals over the hind limbs somewhat flaring, and there is a conspicuous and sharp carina
along each side. The vertebral scutes are like those of No. 1359. There is a considerable
depression on the area of the second, third, and fourth vertebral scutes. No. 1355 is an injured
shell, but shows an anterior slightly concave outline. A peculiarity is presented in the anterior
neurals. The first is broad in front and comes into contact with the second costal plates.
The second is hexagonal, with the shorter sides behind. The third seems to have had four
convex sides. The anterior vertebral scute has been 64 mm. wide; the second, 52 mm. wide.

No. 1351 is a small turtle, 145 mm. long, which has the first and fifth vertebral scutes
about as wide as the second and third.

Fics. 500 AND 501.—Stylemys conspecta. Carapace and plastron of type.
X4. No. 1358 A. M.N. H.

soo. Carapace. sor. Plastron.

Notwithstanding the differences observed among the specimens just described, the writer
feels compelled to refer them all to a single species.

Stylemys cons pecta appears to difter from S. nebrascensis in the following respects: The
shell is narrower in proportion to its length. The width forms about 75 per cent. of the length,
whereas in S. nebrascensis, the width 1s usually, if not always, about 85 per cent. of the length.
In S. nebrascensis the second and third neurals are almost always hexagonal. Only in the
specimen described by Leidy as S. culbertsoni has the writer observed an octagonal second
neural. In only one specimen of S. conspecta, No. 1354, above described, has the second been
observed to be not octagonal, and this specimen has other irregularities. The costal plates of
S. conspecta are more highly differentiated than those of S. nebrascensis, as has been described.
The anterior peripherals of S. conspecta do not extend so far backward from the free border
as those of S. nebrascensis. The position of the sulci between the anterior marginal and the

396 FOSSIL TURTLES OF NORTH AMERICA.

costal scutes of S. cons pecta lies well in front of the hinder border of the peripheral bones. The
carinz along the sides of the Oregon species are usually more distinct than in the White River
form, in which they seem never to be well developt.

Stylemys conspecta belongs to a later epoch than does S. nebrascensis and has evidently
adyvanct to a stage nearer to Testudo than the earlier species.

From S. capax the present species differs in being of a more elongated form and in haying
the free borders of the peripherals very acute instead of obtuse.

Stylemys calaverensis Sinclair.
Text-figs. 502, 503.
Stylemys calaverensts, SiNcLatR, Univ. of Cal. Pubs.; Bull. Dep’t. of Geol., 111, 1903, p. 243, figs. I, 2
This species is represented by little else than the type, which belongs to the University of
California. It was found in the auriferous gravels about 2 miles below Vallecito, Calaveras
County, California. These gravels have been supposed to belong in the Miocene. It has not
been seen by the writer, and ahe following description is based wholly on Sinclair’s description

and illustrations.
The specimen consists of the crusht anterior two-thirds of the carapace and plastron.

The carapace (text-fig. 502) includes the greater portion of the first 6 costals of the left side,
the proximal ends of the second, third, fourth, and fifth costals of the right side, the second

K oe \
J AN

Fics. 502 AND 503.—Stylemys calaverensts. Carapace and plastron of type. &-

502. Carapace. c.p.1,c. p.2, first and second costal bones; .1, 7.2,
neurals; m. s. 3, m.s. 4, third and fourth marginal scutes.
503- Portion of plastron.

and third neurals, and a portion of the first. The plastron is represented from the front to
near the hinder border of the hypoplastron.

In the crushing that has affected the shell there has occurred a slipping of parts near the
midline. The first costal of the left side overlaps a portion of the first neural. The second and
third neurals retain their original relations with the second and third costals of the ght side,
but overlap the proximal ends of those of the left side. The three next costals of the left side
overlap and hide the corresponding neurals. Hence, only the second and third neurals -and
a portion of the first are to be seen.

An estimate based on Sinclair’s description and illustrations and the assumption that the
proportions of the species are about as they are in Stylemys nebrascensis shows that the carapace
had a length of about 405 mm. and a width of about 400 mm., being thus nearly as broad as
long. The bridge peripherals of the left side show distinctly in Sinclair s figure, here repro-
duced, but this is probably due to the crushing of the specimen toward the tight side. On the
other hand the peripherals in front of these show hardly as much of their width as might be

TESTUDINID&. 307

expected. No part of the nuchal appears. The first neural was wider than the second, and in
contact with the second costal. Its greatest width was near 64 mm., while the second has
measured 55 mm. in width. As in some specimens of S. nebrascensis and in probably all
individuals of the John Day species of the genus, the third neural was tetragonal. Correspond-
ing to this condition, the third costal was in contact with the second, third, “and fourth neurals.

The costals are only slightly modified as respects the widths
Proximal Distal of the opposite ends of ‘each. The measurements shown in the

sie end. end. table taken from Sinclair’s description and illustration show the
extent of the modification.
= a eg The carapacial scutes resembled closely those of S. nebra-
; Be 67 scensis. An estimate makes the first vertebral scute to have
5 2 ie been about 184 mm. wide in front. The second vertebral was
a) jot siz

about 108 mm. wide.

The plastron (text-fig. 503) was, according to Sinclair, broken
away at the extremity of the epiplastral lip. It must therefore have been rounded. The
anterior lobe had a length of about 100 mm., the base a width of 200 mm., resembling thus
the anterior lobe of 8. pele ascensis. The entoplastron is rhomboidal in form, thus resem-
bling that of some species of Testudo. Its length is 81 mm., its width is 88 mm. The
portion of the plastron present evidently eeeccd backward to near the hinder border of
the hypoplastron; but did not reach the inguinal notches. The bridge must therefore have
had a width of at least 172 mm.

The sulci separating the scutes of the plastron are stated to be very obscure. The gulars
and humerals resemble those of S. nebrascensts.

It appears to be quite certain that this species belongs to the genus Stylemys. It appears
to differ from all the others in having a very broad first neural, which comes into contact with
the second costal bone, and in having the entoplastron more pointed behind. From the known
John Day species it differs in having the costal bones less wedge-shaped.

Genus TESTUDO Linneus.

Carapace extensively joined to plastron by suture. Inguinal buttresses rising little, if any,
above the costo- peripheral sutures. Second and fourth neurals usually octagonal; the third
and fifth usually quadrangular. Epiplastral lip usually projecting abruptly from the general
contour of the anterior lobe. Plastron notcht behind. Crushing- surfaces of jaws with longi-
tudinal ridges and grooves. No median longitudinal ridge in front of the choanz. Digits
much shortened and foot club-shaped.

Type: Testudo greca Linnzus.

From both Hadrianus and Stylemys this genus is distinguisht by the much higher grade of
differentiation which has been attained by the elements of the shell. From Style mys it 1s
further distinguisht, as it is also from Gopherus, in having no longitudinal ridge in the midline
of the upper jaw in front of the choana. Some living species ‘have the neurals and costals
little more differentiated than in Stylemys, and in T. inusitata, described below, none of the
neurals is octagonal or quadrangular.

ANALYSIS OF THE KNowN NortTH AMERICAN Fossit Species oF Trstupo.

A‘. Oligocene species:
Titanotherium beds.

Peripheral sulci deeply imprest; epiplastral lip more than twice as wide as long .. brontops
2. Costals very thick; deeply imprest by lines of growth of the horny scutes exornata
aa. Oreodon beds.
3. Lip nearly as wide as long; its sides parallel . thomsont
4. Shell flattened; no octagonal neural; epiplastral lip abruptly projecting, tootht
in front . latrcunea
5. Lip truncated, three times as wide as long... ; Irgonta
6. Lip truncated, short; pectoral scutes about one-fourth as wide as abdominals am phithorax
7. Lip square; the gulars not reaching the entoplastron quadrata
8. Lip narrow and wedge-shaped cultrata

398 FOSSIL TURTLES OF NORTH AMERICA.

A*, Lower Miocene species:

g. Lip prominent, twice as wide as long, and nearly as thick aslong...... -. 5. peragrans
10. Pygal convex up and down on upper side........ : _. arenivaga
11. Lip not greatly projecting; pectoral scutes nearly ‘half as ide: on midline as

abdominals ..... re ae vaga

12. No 4-sided or 8-sided netrale: pectoral scutes about one-fifth as mide as slsclave

inals ... ... emtle
A*. Deep River and Pawnee Creek (Middle Miocene) species:

3. Lip not projecting far; pectorals only one-seventh the width of the abdominals. . . farrt
14. Neurals as in 7. emili@; the gulars reaching the entoplastron . . Inusttata
15. Shell broad and deprest; lip tapering; pectorals about one-third the abdominals. . pansa
16. Shell vaulted; pectorals one-twenty-fifth the abdominals, or less . oshorniana

A‘. Loup Fork:
17. Lip abruptly projecting; pectorals one-eighteenth the width of the abdominals . impensa
18. Hinder peripherals and pygal with free border flared upward; pygal narrowing
toward the free border ..... .. undata
19. Pygal plane; its sides parallel : ... klettrana
20. Lip rounded, little projecting; resembles vaga of the Lower Miocene . . ntobrarensts
21. Strongly projecting lip; pectorals about one- -eleventh the width of abdominals.. orthopygta
22. Skull only; consult figures. : ... gilbert
23. First and third neurals 4-sided; second and fourth octagonal; lip prominent;
pectorals about one-fifth the width of abdominals. 3 ede
24. First, third, and fifth neurals 4-sided; second and fourth octagonal; lip moderately
prominent; pectorals one-fourth the width of abdominals. : . holland:

A’. Pliocene species:
25. Lip prominent; all the sulci deeply sunken and wide; free borders of the peripherals

deeply nocht by the sulci. ; . turgida
26. Shell broad and deprest; the perce scutes voiden than long; shell thin... .. pertenuts
27. Lip prominent; truncated; pectoral scutes nearly half as wadey as the abdominals .. cam pester
28. Hinder peripherals thick and with very obtuse free border. . . ; obtusa
29. Anterior lobe of plastron rapidly tapering forward; borders of lip conanued 4 in

same lines; bones thick and heavy crassiscutata

A*. Pleistocene species:
30.. L ip about four-fifths as long as wide, thick behind; notch in rear of plastron four

times as wide as deep. ; . laticaudata

Lip rounded; notch in rear not three times as nige as , deep; borders of hinder
lobe rapidly converging backward hexagonata
32. Lip rounded but prominent; borders of hinder lobe slowly converging. ... atascos@

Testudo brontops Marsh.
Plate 65, figs. 1, 2; text-figs. 504, 505.

T estudo bee Marsu, Amer. Jour. Sci. (3), XL, 1890, p. 179, plate vin; Vert. Foss. Denver Basin,

in Mon. U. S. Geol. Surv., xxvit, 1897, pp. 523, 527, figs. 95, 96.—Dana, Manual Geol., 1896,

p- gol, fig. riba Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451; Amer. Jour. Sci., (4)

XVIII, 1904, p. 272, figs. 6, 7.

The type of this species is a fine large shell which was collected for Prof. O. C. Marsh, 1
the year 1888, by Mr. J. B. Hatcher, and is now in the Peabody Museum, at Yale University.
It was obtained in the Titanotherium beds of Indian Creek, in the southeastern corner of
Pennington County, South Dakota. No considerable parts of the shell are missing and it has
been only slightly crusht. The specimen bears the record “‘ Box 27, 1985.”

In form this magnificent tortoise was broad and probably of only moderate height. The
front of the carapace (plate 65, fig. 1; text-fg. 504) is somewhat concave in outline, the lateral
angles broad, rounded and flaring upward. The sides were nearly perpendicular. The hinder
border is broadly rounded, with the peripherals over the limbs considerably flaring and with
the pygal incurved toward its free border. Where the sulci cross the free borders of the periph-
erals the latter are somewhat notcht; and where they cross the borders of the carapace above
the bridges they lie in grooves so deep that the interspaces appear to be strongly swollen. The
free borders of all the peripherals come down to an acute edge. The length of the carapace
is 711 mm.; the greatest width 1s 651 mm.

TESTUDINID&. 399

The nuchal has probably a width of about 125 mm. along the front border, but here the
sutures are indeterminable. The greatest width is 175 mm. and the length along the midline
150mm. The first neural is oval; the second and the fourth octagonal; the third, hexagonal.

_ The fifth was probably hexagonal, but
Dimensions of neurals. Dimensions of costal bones. a considerable portion of it appears to
So eS ae have been crusht down beneath the

No. | Length. | Width. | No. | Widthof | Widthof | fourth. The sixth, seventh, and eighth
‘ upper end. lower end. :
ie are approximately hexagonal. The
p table gives the dimensions of the
1 127 75 2 56 106 5
2 79 100 5 100 73 neurals.
3 95 97 4 56 go The anterior suprapygal is bifur-
73 va 5 94 5° -ate, having a total height of about 87
: a 7 Z a cate, having a total height of about 87
6 62 87 7 40 5 mm., and inclosing between its right
d 78 8 43 G2 and left limbs the second suprapygal.
Bi 72 |

The latter has a height of 84 mm. on
the midline and a breadth of 125 mm.
The costals are alternately wider and narrower at their upper ends and vice versa at their
lower, but the amount of the differentiation is not great. Omitting the first the dimensions
are given in the table above.

504. 505.
Fics: 504 AND 505.—Testudo brontops. Carapace and plastron of type. 7.
it 595 P i) I Yt
504. Carapace. 505. Plastron.

The upper ends of the third costals have been somewhat injured by crushing. The
proximal ends of the fifth costals also have been damaged so that their exact width is uncertain.
On the right side the greater portion of the fifth costal has been pushed down out of sight.

The second peripheral occupies about 150 mm. of the free border, and extends backward
110 mm. It is nearly flat above, concave beneath, and attains a thickness of 37 mm. The

400 FOSSIL TURTLES OF NORTH AMERICA.

bridge peripherals extend upward about 140 mm. above the slight carina which joins the border
of the third peripheral with that of the seventh. From the seventh peripheral the height of
these bones diminishes to the pygal. The latter has a height of 82 mm.; a width of 125 mm. at
the upper border, and of 100 mm. at the free border.

The nuchal scute is 56 mm. long and only 7 mm. wide. The first vertebral has a width of
230 mm. in front and a length of 165 mm. ‘The transverse extent of the vertebral scutes 1s con-
siderably less than that of the costals. The width of the second is 190 mm.; that of the third
probably about the same, but its lateral boundaries are mostly hidden; that of the fourth is
150 mm.; that of the fifth, at the posterior end,is 180 mm. The second costal scute has a trans-
verse extent of 230 mm.

The sulci between the anterior marginal scutes lie in grooves; and, as they approach the
free border, they curve toward the midline. Those of the bridge region are directed forward at
their lower ends. The lower ends of these sulci and the longitudinal ones between the marginal
and the plastral scutes also he in deep valleys. The supracaudal scute is 175 mm. wide at
its lower end. Its upper end overlaps the gee suprapyg veal bone.

The plastron (plate 65, fig. 2; text-fhg. 505) is quite concave, a condition which indicates
that the animal was a male. The length of the anterior lobe is 222 mm.; its width is 380 mm.
The anterior lip extends beyond the border of the carapace about 60 mm. It projects boldly
from the general contour of the anterior lobe and its lateral borders converge somewhat as they
approach ae bilobed anterior border. The length of the lip beyond the points where the gulo-
humeral sulci cross the free borders of the epiplastra i is 56 mm.; the width at the base is 135 mm.
A broad and deep groove occupies the median line of the lip and ends in the notch in the front
of the lip. The greatest thickness of the lip is 50 mm. The superior surface is somewhat
convex from side to side. In all probability there is an excavation in the hinder portion of the
lip above, but the matrix has not been removed.

The entoplastron has a width of 175 mm. and a length of 120 mm. The bridge is 300 mm.
wide. The hinder lobe has a length of about 175 mm. and a width, at the base, of 370 mm., or
slightly less. The notch in the rear is about 40 mm. deep and about 100 mm. wide. The xiphi-
plastra are each 165 mm. long. Just behind the inguinal notch the border of the posterior lobe
is 50 mm. thick and forms a nearly perpendicular face. Further backward the steepness of
the slope and its height are rapidly reduced.

The sulci bounding the dermal scutes are deeply imprest. Those bounding the gular
scutes lie at the bottom of deep valleys, which proceed forward from the entoplastron, one to
each side of the base of the lip and one to the front on the midline. The gulars encroach some-
what on the front of the entoplastron. The humero-pectoral sulcus starts on each side at the
axillary notch, runs inward and backward, then inward and forward. Near the midline it is
somewhat irregular, bending in its course slightly backward. On the left side it traverses
the border of the entoplastron. The width of the pectoral along the midline is between
50 mm. and 60 mm. The abdominals occupy 240 mm. of the midhne: the femorals, 100 mm;
and the anals, about 60 mm.

A large specimen of Testudo was collected in the Titanotherium beds of South Dakota by
the party from the American Museum in 1904. It appears to belong to this species.

This species is especially interesting because of its being the oldest known North American
species of the genus. T. ammon, described from the Upper Eocene of Egypt, appears to be

still older.

Testudo thomsoni sp. nov.
Plate 66, figs. 1-5.

The only remains of this species at present known were obtained in 1904, by Mr. Albert
Thompson, of the American Museum of Natural History, at Corral Draw, in Ziebach County,
South Dakota. They were found in a block of limestone which had come from the Lower
Oreodon beds. The parts secured are the skull, the greater portion of the anterior lobe of the
plastron, some cervical vertebra, and parts of the left foreleg. These bear the catalog number
3940. Other portions of the skeleton were in the block; but they were not secured, because
they were supposed to belong to the very common species, Stylemys nebrascensis.

TESTUDINID. 401

That which distinguishes this species from those of the genus Stylemys is the prominent
epiplastral lip (plate 66, fig. 1). How long this was originally it is now impossible to say,
for the anterior end has been broken away. The portion remaining extends 32 mm. beyond a
line joining the anterior ends of the gulo-humeral sulci. The thickness of the broken end is
26mm. It appears probable therefore that the lip was at least 60 mm. long. Its width at the
base is 80 mm. The lower and upper faces are convex from side to side. The free edges are
acute, as are also the epiplastral edges behind the lip. Opposite the anterior ends of the gulo-
humeral sulci the thickness of the lip is 32 mm. Seen from below, the plastron rises toward the
lip, so that the latter projects on a slightly higher plane. Seen from the upper side, the lip is
carried backward 20 mm. behind the line joining the anterior ends of the gulo-humeral sulci.
It attains a thickness of 35 mm., then slopes off rapidly to the entoplastron.

The entoplastron has a length of 93 mm. along the midline and a width of 107 mm. Its
form is approximately rhomboidal.

The gular scutes extend on the entoplastral bone. The sulci are deeply imprest. Altho
the plastron is present at the midline a distance of 40 mm. behind the hinder border of the ento-
plastron, there is no certain trace of the humero-pectoral sulcus.

The skull is in a good state of preservation. The premaxilla are missing, as are most of
the right maxilla, the tip of the left dentary, and the anterior half of the right dentary.

The length of the skull (plate 66, figs. 2-4) from the upper border of the nasal opening to
the occipital condyle is 85 mm. The breadth just in front of the tympanic cavities is 62 mm.;
between the outer borders of the articulation of the lower jaw, 60 mm. In front of the temporal
fosse the upper surface of the skull is quite flat. Seen from the side the upper surface of the
skull is nearly straight from the snout to the end of the supraoccipital. The interorbital space
is 23mm. wide. The jugal arch has a height of 13 mm.; the postorbital arch a width of 10 mm.
The frontals furnisht a small portion of the rim of the orbit. The antero-posterior diameter
of the orbit is 24 mm.; the perpendicular diameter, 18 mm. The roof of the mouth is moder-
ately vaulted, and is traverst along the midline by a sharp ridge. The triturating surface of the
upper jaw has a longitudinal rough ridge and a less conspicuous inner ridge. Posteriorly the
palate is reduced to a width of 13 mm.

The dentary bone (plate 66, fig. 5) is channeled from the coronoid process to near the
symphysis, to receive the dentated ridge of the upper jaw. The lower jaw is 19 mm. high at the
coronoid process.

The distal half of the left humerus is present. The width of the distal end is 54mm. The
left radius has an extreme length of 92 mm. A claw phalange has a length of 20 mm. and a
width of 16 mm.

The cervical vertebra are more or less damaged. One has the centrum 40 mm. long.

This was a large turtle, the length of the carapace being estimated at about 625 mm.

Thru the kindness of Dr. S. W. Williston, of the University of Chicago, the writer has
been permitted to examine a testudinid skull which was collected in 1894 by Dr. George Baur.
It was obtained in the same locality as the specimen above described and probably in the same
beds. The skull is somewhat fragmentary and lacks the symphyses of the upper and lower
jaws. It appears to have belonged to 7. thomsonz, but it presents some differences. The orbit
is more nearly circular than in the type; but the type may have suffered some distortion in this
region. The upper longitudinal outline of the skull of Dr. Baur’s specimen is not so straight,
the supraoccipital crest not rising so high. The skull is that of a smaller specimen and the
depression of the crest may be due to an earlier stage of growth, to sex, or to individual
variation.

Testudo exornata Lambe.
Plate 66, figs. 6, 7; text-figs. 506-508.
Testudo exornata, Lambe, The Ottawa Naturalist, x1x, 1906, p. 187, plate i, figs. 1-3.

All the known specimens of the present species belong to the Geological Survey of Canada.
They consist wholly of fragments of costal plates, which were collected in 1904, by Mr. Law-
rence M. Lambe, vertebrate paleontologist of the Canadian Survey, in the Oligocene beds of

26

402 FOSSIL TURTLES OF NORTH AMERICA.

the Cypress Hills, Assiniboia. These costals are remarkable for their thickness, the deeply
imprest sulci, and the strongly markt lines of growth of the horny scutes.

Figs. 6 and 7 of plate 66 represent the distal half of the left fifth costal, which is taken by
Mr. Lambe as the type of the species. Fig. 6 shows the outer surface. Thisi is 12 mm. wide at
the upper end, 10 mm. at the lower. It might be taken for the bone of a young animal were
it not for the great thickness. The anterior sutural border has a thickness of a little more than
4mm. From this border the bone thickens rapidly, so that the posterior border, at the lower
end of the bone, is 8 mm. thick. Seen from the inner surface (fig. 7) the bone presents, on the
hinder half of its width, a prominent half-ridge, which was evidently completed on the succeed-
ing costal. The larger portion of the ridge has been on the sixth costal, and has been developt
to receive the inguinal buttress of the plastron. It looks indeed as if this buttress had ascended
about 15 mm. above the border of the costals and had been articulated with both the fifth and
the sixth, but principally with the latter. So far as the writer is aware, in other species of T estudo
the buttress articulates only with the sixth
costal. At the lower end of the fifth costal is
a pit for a process of the seventh peripheral.
It is evident that this costal was much broader
at the proximal end than at the distal.

There is present a portion of the left first
costal plate (fg. 506). In this figure the
upper border was directed toward the head,
the right hand border toward the first neural.
At the upper end the fore-and-aft width of

Fics. 506-508.—Testudo exornata. Costals the bone was about 30 mm. From this it 1s
of type. XT. estimated that the length of the carapace was
506. Fragment of first costal. about 200 mm. At its posterior border the

507. Proximal end of sixth costal.

508. Proximal half of third or fifth costal. bone ue 4-5 wanlonk thick, On the iabaKee EAU

face is a ridge which past upward into the
head of the rib. The outer surface of the bone 1s ane by the lines of growth of the
first costal scute. Fig. 507 represents the outer surface of the proximal end of another costal,
probably the sixth costal of the left side. Where the bone joined the sixth neural it is 8 mm.
thick. The sulci are narrow, but deeply imprest. The outer surface shows the lines of
growth of the scutes. At its upper end the bone is 15 mm. wide and appears to have expanded
toward the distal end.

Fig. 508 represents a costal of a young individual, evidently the third or the fifth, probably
the fifth of the right side. The width at the upper end is 12 mm. The width at the distal end
of the fragment, probably about the middle of the length of the costal, has increased to g mm.
Its thickness is a little more than 3 mm. On the under side of the bone is found the base of a
rather well-developt rib-head.

Testudo laticunea Cope.

Plate 67, figs. 1, 2; text-figs. 509-515.

Testudo laticunea, Corr, Paleont. Bull. No. 15, 1873, p. 6; Synop. New Vert. Tert. Colorado, 1873,
p- 19; Ann. Rep. Geol. oe Surv. Terrs., 1873 (1874), p. 511; Vert. Tert. Form. West, 1884,
pp- 762, 765, plate Ixi, figs. 1, ta.—Hay, Bibliog. a Cat. Foss. Vert. N. A., 1902, p. 451.

In his original description Professor Cope states that he had in his possession several speci-
mens of this species, but he does not designate any as the type. In his description of 1884 one
individual in a good state of preservation was used as the basis of the description and was
heured. ‘This must now be regarded as the type, especially since the other specimens occur-
ring in the Cope collection are very fragmentary. This type is now in the American Museum
of Natural History and bears the ts 1160. All of Cope’ s specimens were obtained in the
Oligocene beds at the head of Horse Tail Creek, in northeastern Colorado. These deposits
belong to the level known as the Oreodon beds.

The specimen is slightly distorted, somewhat fractured, and some portions are missing.
A fracture extends along the midline of the anterior part of the carapace and the elements of

TESTUDINIDA. 403

the right side have been thrust forward about 10 mm. in front of those on the left. Some por-
tions of neurals, costals, and peripherals are missing, especially on the right side, but all parts
are represented on one side or the other. The outer ends of the hyoplastra are wanting and
part of the outer end of the left hypoplastron. ;

The species was a broad and rather deprest one, and in many respects it resembled the recent
Gopherus polyphemus. The following table presents some of the dimensions. When Cope’s
measurements differ they are added in parentheses.

Length of carapace ... 420 (408) Width of anterior lobe......... uses: 200
Width of carapace..... 356 Greatest length of posterior lobe 120
Greatest length of plastron 440 Width of base of posterior lobe ..+ 210 (200)
Length of anterior lobe 132

The anterior border of the carapace (plate 67, hg. 1; text-fig. 509) is truncate; the pos-
terior border between truncate and rounded. The free edge is everywhere acute. Where the

509. Sa ee

4

| eer ee

i

Fics. 509 AND 510.—Testudo laticunea. Carapace and plastron of type. 4.

50g. Carapace. 510. Plastron.

sulci between the marginal scutes cross the free border there is present a tooth or mucro. The
height of the bridge peripherals was about 85 mm.; while the extent of the corresponding
costals, transverse to the animal, was about 145 mm. The greatest thickness of the first periph-
eralis 18 mm. The nuchal bone occupies 62 mm. of the free border, and its greatest width is
g5 mm. The hinder peripherals have a slight flare. The eighth has a height of 70 mm. anda
thickness of 22 mm. The pygal has a length of 34 mm. along the midline, a transverse extent
of 57 mm. at the upper border, and of 45 mm. along the free border. The first suprapygal is
bifurcate and comes into contact with the eleventh peripheral of each side, but not with the
pygal. The second pygal is broader than long.

The neurals have not attained so. high a degree of differentiation of form as they have in
most of the species of the genus. None of the series:is octagonal. All are hexagonal, except

404 FOSSIL TURTLES OF NORTH AMERICA.

the third, which is nearly square, and the fifth, which is rhomboidal. ‘The table gives the great-

est length and width of each neural.
The costal plates have undergone considerable differentiation in form. ‘The second,
fourth, sixth, and eighth have narrow proximal ends and wide distal ends; while the third
and fifth have wide proximal and narrow distal ends. The

Neurats (| "Hedeeh. > width. third comes into contact with 3 neurals, the fifth with only 2.
It is not unlikely, however, that other individuals will present
variations in the forms of the neurals and costals.
’ 58 “ The free borders of the plastron (plate 67, fig. 2; text-fg. 510)
; es Ee are acute. The dimensions of the lobes are given in the table of
4 35 50 measurements. ‘The anterior lip projects beyond the front of the
"i Se ve carapace about 50 mm. The base is 87 mm. wide from the
7 28 46 crossings of the gular sulci over the free border. The length of
8 28 29

the lip is 43 mm. The sides converge somewhat, and the rounded
anterior border is furnisht with 6 blunt teeth. The upper surface
of the lip is convex, and it rises backward until the thickness becomes 33 mm. The hinder
face of this thickening is somewhat excavated. The entoplastron is pointed in front, broad
and somewhat rounded behind.

The posterior lobe ends behind in 2 broadly rounded apices, which inclose a deep and
sharp notch. The borders of the apices are tootht. Just behind the inguinal notch the border
of the hypoplastron forms a wall about 25 mm. high. From the summit of this there is a slope
to the free edge.

The sulci of the carapace are narrow grooves with raised edges. The nuchal scute has a
width of 28 mm. behind, but it is narrower in front. The sulci on the bridges are directed
downward and forward. The vertebral scutes have considerably
less lateral extent than do the costals. The accompanying table

ee aa Bea ig presents in millimeters the greatest length and width of the
vertebrals.
: “4 eos The gular scutes encroach on the entoplastron. The humeral
; 81 8c scutes meet along the midline for 76 mm.; the pectorals, 56 mm.;
4 75 82 the abdominal, 118 mm.; the femoral, 52 mm.; the anal, 36 mm.
5 go 135

Of the other parts of the skeleton there are present the
humerus, the pelvis, both femora, and the right tibia. The
humerus (fig. 511) lacks the distal end. It was bent more strongly than that of Gopherus
polyphemus, and the tuberosities are more strongly developt. athe pelvis 1 is represented by
hes. 512 and 513. The ischial tuberosities are pointed, and their apices are 45 mm. apart.
The extremity of the lateral and anterior pubic processes are missing. The ilium has the
proximal end much broadened antero-posteriorly, it being about 44 mm. The femur (figs.
514, 515) 1s unusually straight. The digital fossa is rather deep.

In the Marsh collection at Yale Univ ersity there is a large specimen which 1s to be referred
to this species. It was collected for Professor Marsh by Mr. ]. B. Hatcher in the year 1889,
in the Titanotherium beds of South Dakota. It is at present designated by the receipt numbers
“2054, box 1.’’. The specimen was flattened somewhat during inne but it was probably
originally of deprest form. Most of the hinder peripherals, are now missing, as is also the
plastral lip. The second neural of this individual is octagonal, but the aides which are in
contact with the first and third costals of each side are very short. The third neural is approx-
imately square. All the others are hexagonal. The two suprapygals are about as in the type.
The costal plates are strongly modified, having their proximal

Qoeul Width Width ends alternately narrow and wide, while the distal ends are
vpperend. Towerend- alternately wide and narrow. Their dimensions are presented

in the table herewith.
i ‘6 The first peripheral has an extent, backward from the free

38 8s edge, of 50 mm. The bridge peripherals rise a distance of 88

Aun WwW wv

38 25 mm. above the carina which joins the free border of the third
, 3 5 peripheral with that of the seventh. On some of the free periph-

erals there is found a mucro, as in the type specimen.

TESTUDINID&. 405

The plastron shows no especial differences when compared with that of the type. ‘The
apices of the xiphiplastron are not notcht, in this way differing slightly from those of the
original specimen. ;

No. 238 of the Carnegie Museum, Pittsburg, is a third known specimen of this species.
It is a complete shell, which was collected by Prof. ]. B. Hatcher from the Oreodon beds of
the Oligocene, at Warbonnet, Sioux County, Nebraska. The carapace is 375 mm. long
and 325 mm. wide. Like the other specimens, it is deprest. When compared with the type

512. 513.

Fics. 511-515.—T estudo laticunea. Humerus, femur, and pelvis of type. 3.

Sits Proximal portion of left humerus. 512. Pelvis, seen from below.
513. Pelvis, seen from left side. 1/, slum; 514. Left femur, dorsal surface.
isch, ischiur; pub, pubis. 515. Left femur, tibial border.

there appear to be no important differences. The sulci run along the summits of low ridges,
as in the type. Those of the hinder peripherals end at the free margins of the latter on pro-
jecting points.

The only important feature of the plastron is found in the shape of the anterior lobe.
This is more wedge-shaped than in the type specimen, the convexity of the free border, from
the axillary notch to the gulo-humeral sulci being much less pronounct. The epiplastral lip
is notcht and tootht in front like that of the type.

Testudo ligonia Cope.
Figs. 516-525.
Testudo ligontus, Cope, Paleont. Bull. No. 15, p. 6, 1873; Synop. New Vert. Tert. Colorado, 1873,

p.19; Ann. Rep. U.S. Geol. and Geog. Surv. Terrs., 1873 (1874), p. 511; Vert. Tert. Form. West.,
1884, pp. 762, 766, plate Ixi, figs. 2, 3.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451.

This species was based on a single imperfect individual, and no others have yet been
secured. The type belongs to the Cope collection in the American Museum of Natural
History and bears the number 1148. It was collected by Cope in 1873, in the Oreodon beds
of the White River deposits, at the head ot Horse Tail Creek in northeastern Colorado. It
consists of a portion of the nuchal bone, the first and probably the ninth right peripherals,
the left epiplastron, a part of the left hyoplastron, and the left hypoplastron in the region of

400

FOSSIL TURTLES OF NORTH AMERICA.
the inguinal notch.

Another peripheral is present which has the same texture and general
appearance as the other bones, but it possibly belongs to another turtle. If pertaining to this
skeleton it can be only the eleventh.

a
tere ey

\
\
Ny
4
\
ae 4 5
a
Se ry
517. 518
Fics. 516-518.—Testudo ligonia. Parts of carapace of type. X 4%.
516. First peripheral and part of nuchal.

nu. p, nuchal plate; nu. s, nuchal scute; per, 1, first peripheral
517. Section of first peripheral near union with second. Upper surface toward the left.
518. Ninth peripheral of type.

The nuchal (fig. 516) had a length, in the median line, of about 100 mm.; a width, at the
free border, of 70 mm.; and a maximum width of 108 mm. The greatest thickness, at the
midline, is 21 mm. The portion occupied by the first vertebral scute stands at a distinct angle
with that in front of it. The first peripheral has a fore-and-aft extent of 81.mm., of which 75
mm. has been exposed on the upper surface. The thickness of the sutural border next the

[

*

DS

f i

wi
N
al

519.

Fics. 51 9-522.—T estudo ligonta.

§22.
Peripherals and epiplast of type. 4.
519. Section of ninth peripheral, near union with eighth.
521. Section of eleventh peripheral, near union with tenth.

520. Supposed eleventh peripheral.

522. Upper view of left epiplastron.
second peripheral is 26 mm. The free borders of these bones are acute. Fig. 517 1s a section
taken near the articulation with the second peripheral.

The ninth peripheral (fig. 518) is high and narrow, the height being 92 mm., the width
along the free border 24 mm. There is no flare, and the free border is acute. The greatest
thickness, at a point 73 mm. above the free border, is 24 mm. Fig. 519 is a section taken near

the anterior sutural border. The free edge is acute. If the remaining peripheral (fig. 520)

TESTUDINID#. 407

belongs to this specimen it must be the eleventh, and the height of the peripherals was rapidly
reduced from the ninth, inasmuch as the supposed eleventh is only 64 mm. high. Its thickness
is 26 mm. The upper surface is nearly plane, while the inferior is convex in section at right
angle with the free border. Fig. 521 is a section taken near the posterior sutural border. Cope’s
measurements indicate that he had one other hinder peripheral, but this is not now present.
Curiously enough, his dimensions apply exactly to the first right peripheral.

The sulci are narrow and sharply imprest. The nuchal scute is 40 mm. long and only 9
mm. wide. On the lower side of the bone this scute has a posterior width of 25 mm. The
sulcus between the first and second marginals is 62 mm. long. The anterior width of the first
vertebral has been 58 mm.

Professor Cope figured the left epiplastron, as seen from below; but he erroneously stated
that the view is from above. A figure is here presented of the bone as seen from above (fig.
522). The anterior lip projects abruptly from the general outline of the anterior lobe for a
distance of 35 mm. The anterior border of the lip is truncate, with the angle between it and
the lateral border clipt off. The whole free edge of the epiplastron is acute, except near
the midline, where it is slightly rounded. From the free edge of the lip the bone thickens

ma og \
- “ tae en marae narmamee, an
oe — Pm ‘
ae ne pee \
ad, ann . } / =— ,)
as on H g@ a ca Seana eaien eos }
a j oe NN,
| . es
{ ee =
i eae Se ae \
b 7 | — cua: -
i = la = = ) b LG = )
523. 524. 525.

Fics. 523-525.—T estudo ligonta. Parts of plastron of type. 3.

523. Fragment of left hypoplastron, lower surface. a, suture with seventh peripheral; bc, suture with xiphiplastron;

bd, suture with right hypoplastron.

524. Section across left hypoplastron just in front of union with xiphiplastron. a, outer border; b, border at midline.

525. Fragment of hyoplastron. Shows suture, cd, for union with entoplastron; pec, pectoral scute.
backward until it attains a thickness of 32 mm.; then suddenly drops off to 17 mm. ‘The
portion of the epiplastron in front of the gulo-humeral sulcus projects nearly horizontally for-
ward, while the portion behind it ascends to meet it. On the lower side there is a decided
angle between the two portions. The sulcus runs forward in this angle.

The fragment of hypoplastron (fig. 523) extends from the inguinal notch to the longitudinal
median suture and backward to the suture with the xiphiplastron. The base of the hinder
lobe is shown to have been 188 mm. wide. From the buttress a rounded ridge (fig. 524)
descended which past backward on the summit of a wall surmounting the border of the
lobe. The outer face of the wall is convex and 30 mm. high. From the summit the inner face
slopes gradually to the midline. The lower surface of this bone displays faint grooves on the
area of the femoral scute.

The sulci of the plastron, like those of the carapace, are narrow and sharply imprest.
The gular scutes encroacht on the epiplastra. The humero-pectoral sulcus (fig. 525) crost the
midline about 8 mm. behind the entoplastron. The pectorals are 18 mm. wide at the midline.

Under the species 7. qguadrata will be found mention of characters which distinguish it
from the present species.

Testudo amphithorax Cope.
Figs. 526-531.
Testudo amphithorax, Cope, Palzont. Bull. No. 15, 1873, p.6; Synop. New Vert. Tert. Colorado, 1873,

p. 1g; Ann. Rep. Geol. and Geog. Surv. Terrs., 1873 (1874), p- 5115 Vert. Tert. Form. West., 1884,

p- 767, plate Ixi, fig. 4—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p- 451-

Of this species Cope possest portions of 2 individuals which display the anterior lobe of
the plastron, and another which lackt this lobe. These specimens are now in the American
Museum of Natural History. The portions of the plastron which Cope figured are included

408 FOSSIL TURTLES OF NORTH AMERICA.

under the museum’s No. 1145, but this author states that the anterior lobe does not belong to
the same individual as the posterior. No other parts of the skeleton belong with these plastral
bones.

hypo

53°:

Fics. 526-530.—Testudo amphithorax. Portions of shell.

526. Front of carapace. 4. No.1139A.M.N.H. c. p.1, part of first costal plate; nu. p., nuchal plate; nu.s,
nuchal scute; per. 1, part of first costal plate.

527. Lateral view of part of shell. 1}. No. 1139 A.M.N.H. c. p.5, fifth costal plate; hyo, hyoplastron;
hypo, hypoplastron; per. 4, per. 7, per. 11, fourth, seventh and eleventh peripherals; py, pygal; spy. 1,
Spy, 2, first and second suprapygals.

528. Rear of carapace. x4. No. 1139 A.M.N.H. c. p.8, eighth costal plate; sc, supracaudal scute; spy. I,
spy. 2, first and second suprapygals.

529. Plastron. 4}. Anterior half from No. 1139 A.M. N. H.; posterior half from No. 1147 A. M.N.H.

530. Upper surface of anterior end of plastron. 4. No. 1139 A.M.N.H. ent, entoplastron; ep, epiplastron,.

531. Upper surface of left xiphiplastron. 1. No.1147 A.M.N.H. an, anal scute; fem, femoral scute; hypo,
bypoplastron; xrph, xiphiplastron.

Another specimen, No. 1139, includes the anterior half of the plastron; a little more than
the right half of the anterior rim of the carapace; a little more than the left half of the
posterior rim, together with most of the bridge peripherals of that side and the distal ends of
several costals; the pygal and both suprapygals; the greater portion of the shoulder-girdle;
and unimportant parts of the pelvis. What appears to be Cope’s third specimen consists of
the hypoplastron and the xiphiplastron of the left side. It has the number 1147. Most of the

ESTUDINIDZ&. 409

following description is taken from No. 1139. All the known specimens were collected in the
White River deposits (Oreodon beds), at the head of Horse Tail Creek, in northeastern
Colorado.

The members of this species appear to have had a rather narrow and elongated shell;
and this was probably considerably elevated. The form was therefore somewhat like that of
Stylemys oregonensts or that of the living Testudo tabulata.

The length of the carapace was close to 460 mm., and the width approximately 3 300 mm.
The anterior part of the carapace which has been preserved (hg. 526) consists of a portion of
the left first peripheral, nearly the whole of the nuchal, the first, second, and most of the third,
right peripherals, and a part of the first right costal. The anterior border is somewhat concave
along the nuchal and part of the first peripheral; then it passes by a broad curve into the side.
The free edge of this rim is subacute, but it is considerably roughened. The nuchal is 76 mm.
wide along the free border; 126 mm. in maximum width, and about 100 mm. along the median
line. Its greatest thickness at the midline is 25 mm. The border of the first peripheral i is 77
mm. long; that of the second is 75 mm. The anterior peripherals are but little flared.

The bridge peripherals preserved (fig. 527) are part of the fourth, most of the fifth, sixth,
and seventh. Each was about 50 mm. wide and 110 mm. high. A rather deep groove runs
along the side of the shell just above the lower ends of these peripherals.

The posterior peripherals (fig. 527) and practically the whole of the pygal (fig. 528) are
present. The free edges of all these are acute. The tenth and the eleventh flare slightly.
The eighth is 80 mm. high; the eleventh, 63 mm. The thickness of each is about 22 mm.
The inferior surface is convex in perpendicular section. The pygal is convex above in all
directions. The upper border is 80 mm. wide and somewhat excavated for the second supra-
pygal; the free border is only about 25 mm. wide. The thickness is 17 mm. The second
suprapygal is broadly triangular, with a repand base. The height is 50 mm., the width 80
mm. The penultimate suprapygal (hg. 528) has the usual bifincate form, with the forks
resting on the eleventh peripherals. The hinder portion of the carapace has sloped downward
and backward at an angle of about 45°.

The fourth costal had a width of about 60 mm. at its lower end; the fifth, a width of 34
mm.; the sixth, a width of 49 mm.; the seventh, a width of 33 mm.; the eighth, a width of
44mm. The costals have a thickness of about 8mm. No neurals have been preserved.

The sulci which limit the dermal scutes of the carapace are usually narrow and only
slightly imprest, that passing between the costals and the marginals being broadest and
deepest.

The nuchal scute is 36 mm. long and 16 mm. wide. The first marginal is 53 mm. along
its anterior border and 81 mm. along the hinder, an unusual form. The second is 77 mm.
wide along the free border; 30 mm. along the posterior border. The third has a width of 69
mm. along the free border. The first vertebral had a width of 146 mm. across the anterior
end, but acrewee posteriorly. The hinder end of the fifth had a width of about 80 mm.
Since most of the median region of the carapace is missing, nothing is to be learned regarding
the other vertebrals.

The height of the supracaudal scute (fg. 528, sc) is 73 mm.; its width 100 mm. Its upper
border rises on the second peripheral about 20 mm.

As already stated, only the anterior half of the plastron of No. 1139 is present. Nor is
there at command any plastron which furnishes both the hinder and the anterior portions.
It is hence impossible to determine exactly the length of this portion of the shell. The length
of the anterior half of No. 1139 (fig. 529, front portion), to the hyohypoplastral suture, is 238
mm. The length of the hinder portion of the type plastron figured by Cope (fig. 529, hinder
portion), measuring backward from the hyohypoplastral suture, is 256 mm. This applied to
the anterior half of 1139 would bring the hinder border too close to the pygal and therefore
must have belonged to a somewhat larger individual than the latter. About 220 mm. may be
added to the length of the anterior half of 1139, thus making its plastron 458 mm. long. This
implies that the anterior lip must have projected somewhat in front of the anterior border of
the carapace, and this conclusion has been reacht on other grounds.

The anterior lobe of No. 1139 has a length of 165 mm. and a width of 214 mm. The free
edge is acute, except at the midline, where it is somewhat rounded. The anterior lip does not

410 FOSSIL TURTLES OF NORTH AMERICA.

project beyond the general border of the lobe. It is truncated in front. The distance between
the crossings of the gular sulci over the free border is 110 mm. On the upper side (fg. 539),
the lip extends backward 60 mm., thickening until it reaches 36 mm. There is no excavation
behind the thickened portion. The suture between the epiplastrals is 65 mm. long. The
entoplastron 1 is hexagonal, pointed 1 in front, broad behind. The length along the midlinca is
108 mm.; its greatest breadth is 104 mm. The hinder lobe may be described from Cope’s
type. In this individual the hinder lobe was 240 mm. wide and 143 mm. long to the ends of
the xiphiplastral apices. The notch in the rear was about 76 mm. wide and 37 mm. deep.
In the median portion of this lobe the bone is about 15 mm. thick, but at the inguinal notch
the thickness is 42 mm. Here the outer face is almost perpendicular, but it at once begins to
slope inward and upward and to diminish in height, so that at the apices of the xiphiplastra
the face looks upward and the thickness is only 27 mm. On these apices the face 1s 56 mm.
wide. From the inguinal notch backward this face is separated from the remainder of the
bone by a rather sharp ridge. “This markt the boundary between the skin and the bone
covered with horn. In the case of both the specimens furnishing the posterior lobe there is a
sharp notch, about 6 mm. deep, at the very apex of the xiphiplastron.

The gular scutes encroach on theentoplastron. The humero-pectoral sulci pass close behind
it. The pectoral scutes are about 20 mm. wide at the midline; the abdominals about 75mm.;
the xiphiplastrals, 50 mm. All of the sulci are narrow, but some are rather deeply imprest.

A portion of another plastron, No. 1147 (fig. 531), consisting of the left hypoplastron and
the left xiphiplastron, has a length of 255 mm. The horn-coy ered surface on the apex of the
xiphiplastron is 74 mm. wide.

The elements of the right half of the shoulder-girdle are present. The scapula is about
105 mm. long and 14 mm. wide at the middle of its length. The coracoid is 75 mm. long,
and its median border is 60 mm. long. The scapula and the procoracoid process make a little
more than a right angle with each other.

‘There are in the Meccan Museum of Natural History portions of 2 shells from the same

region as those described above which are referred with some doubt to the same species.
They were considerably larger and had thicker bones. Other specimens still, No. 1146 of the
same museum, collected on Old Woman’s Creek, Wyoming, in White River deposits, may
belong to T. amphithorax, but the more characteristic parts are missing. The borders of the
hinder lobe are identical in form with those of the type specimen.

Testudo quadrata Cope.

Text-figs. 532, 533.

Testudo quadratus, Cope, Vert. Vert. Form. West, 1884, p. 764, plate Ixi, fig. 5 —Hay, Bibliog. and Cat.
Foss. Vert. N. A., 1902, p. 451.

This species is based on the lip of a plastron and a portion of a nuchal bone. Notwith-
standing the meager nature of these materials, there can be no question regarding the distinct-
ness of the species. The remains were collected by Cope in 1873, in the Oreodon beds of the
White River deposits, at the head of Horse Tail Creek, in northeastern Colorado. The
individual was evidently a large one. The type specimen is in the American Museum of
Natural History and bears the number 1149.

The anterior lip (fig. 532) projected much beyond the general outline of the front lobe.
The right and left Borders are parallel. “The anterior botder has crumbled away somewhat,
except at a point near the midline; but it was doubtless truncated, with probably a slight
notch at the midline. The lateral and probably also the anterior borders were acute. The
upper surface is slightly convex, the lower nearly flat. Evidently the lip formed something of
an angle with the ascending lower surface of the plastron. The hinder face of the upper
part of the lip was not excavated.

What distinguishes this species from all others of our region is the form of the gular scutes.
Instead of extending back on the entoplastron, they end at the base of the lip at a sulcus
which runs at right angles with the midline. Each scute is therefore about square. The
following are dineneion: of this lip: Length of lip from gulo-humeral sulcus, 70 mm.; width
of lip at base, 120 mm.; thickness at the base, 29 mm.

TESTUDINID. 4I!I

All of the sulci present on the fragment are deeply imprest.

The fragment of the nuchal (fig. 533) is not very instructive. It comes to an acute edge
in front, and thickens backward to 31 mm. Portions of 3 scutes are shown—the nuchal, the
first peripheral, and the first vertebral. The nuchal had a length of 41 mm. Its width is
indeterminable, but exceeded 17 mm. On the lower side of the bone the nuchal scute was con-
siderably wider than above.
Nothing can be determined
regarding the dimensions of
the other scutes. The sulci
are deeply imprest and have
raised borders.

In its abruptly projecting
lip this species resembles some-
what 7. /rgonia found in the
same region. ‘The differences
nace opae, ocd. are, however, very obvious. As

; seen from the lower side of

532- Epiplastral lip, upper surface. : the plastron, the gulo-humeral

533+ Portion of nuchal once c. 5. 1, part of us costal scute; m. s. 1, part Se lciate livonia. departing

of first marginal scute; nu. s,nuchal scute. ‘ eae i 5

from the free borders of the

epiplastra, run backward and inward at an angle of about 45° with the midline, to end on the

entoplastron. In 7. quadrata the gulo-humeral sulci run across the epiplastra at a right angle

with the midline and do not touch the entoplastron. In 7. /:gonca the lip, as seen on the upper

side, continues backward on the epiplastra a distance even greater from a line joining the

anterior ends of the gulo-humeral sulci than it does in front of this line. In 7. guadrata, on
the contrary, the lip extends behind the line mentioned a very short distance.

Testudo cultrata Cope.

Testudo cultratus, Cope, Palieont. Bull. No. 15, 1873, p. 6; Synop. New Tert. Vert., 1873, p. 19; Ann.
Rept. U. S. Geol. and Geog. Surv. Terrs., 1873 (1874), p. 511; Vert. Tert. Form. West, 1884, pp.
762, 763, plate Ixini, figs. 1-3; Geol. Surv. Texas, 3d Ann. Rept., 1891 (1892), p. 256.

Testudo cultrata, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451.

The basis of this species is said by Professor Cope to have been two imperfect specimens
found by him in 1873, in the White River deposits, at the head of Horse Tail Creek, in north-
eastern Colorado. The level is that of the Oreodon beds, the middle of the White River.
The specimens described by this author have not yet been found in the Cope collection in the
American Museum nor in the U. S. National Museum. For this reason, it is thought best to
reproduce here Cope’s description.

Parts of two individuals of this species were obtained by my expedition of 1873.

This is the smallest of the five species of Testudo, having about the average size of the Stylemys
nebrascensis. This is indicated by the costal and marginal bones which accompany the portions of
plastron of both specimens. The width of the lip at the base is also less than that of any of the other
species, but the length and thickness are remarkable as compared with the other dimensions. The width
and thickness at the base of the lip are nearly equal; both dimensions diminish to the apex, which 1s
obtusely acuminate. The superior face of the lip is gently convex in both dimensions. The inferior
surface is plane anteroposteriorly; transversely it rises to the external edge, which is subacute. The
suture of the gular scutum is directed posteriorly, giving the usual triangular form. The thickness of
the lip is abruptly reduced above, where the surface descends to the mesosternal bone.

The lip of one of the specimens is fissured deeply, in an eccentric manner, on both sides of central
core. Whether this or the unfissured condition is characteristic of the species or not, is uncertain. It
appears to be homologous with the dentation in the lip of T. laticuneus.

The marginal bones are robust, and are much thickened below. The edges of those of the posterior
margin are acute, while those of the anterior border are obtuse, thus differing from those of T. /aticuneus,
where they are acute. At the points where the dermal sutures reach the margin, both specimens are
unfortunately broken in every instance, so that the question of notches or mucros can not be decided.
The costal bones are moderately thick, and alternate in width, narrower and wider. The dermal sutures

412 FOSSIL TURTLES OF NORTH AMERICA.

do not display raised margins. The anal marginal bone is wedge-shaped, with the posterior margin
representing a truncate apex. Its surface and margin are convex, and the anterior sutural margin is
concave.

A fragment, which is in all probability the posterior lobe of the plastron, is characteristic. It is
thick, and its inferior face is somewhat recurved posteriorly. The outline of the margin presents a pro-
nounced obtuse angle, and the edge is several times abruptly notched.

MEASUREMENTS OF No. 1.

Diameter of half of lip:

At base
Vertical . 0.040
Transverse 043
Length outer edge : 056
Diameter second marginal from anal :
Thickness Sitgoanate : . 019
Width. . .030
Length free margin of anal 026
Width of anal above sam .050
Thickness of a vertebral bone. ; Ol
Thickness of a costal at middle. . : . 009

Found by myself near the head of Horse Tail Creek, in northeastern Colorado.

Cope has explained his fig. 1 as that of the right half of the lip seen from above. This may
be correct, but it is probable that it presents the left half of the lip seen from below.

Fics. 534 AND 535. Testudo peragrans. Skull of type. XT.

534. Upper surface. 535- Lower surface.

Testudo peragrans Hay.
Figs. 534-538.
Testudo peragrans, Hay, Ann. Carnegie Mus., Iv, 1906 (1907), p. 15, figs. 1-5.

The type and at present only known specimen of this species is No. 1101 of Carnegie
Museum, Pittsburg, Pennsylvania. It was collected by Mr. Earl Douglass, in 1903, south of
McCarty’s Mountain and Big Hole River and north of Dillon, Montana. There is at present
some uncertainty regarding the age of the deposits. They may be either Oligocene or Lower
Miocene.

The specimen furnishes the damaged carapace and plastron and a nearly complete skull.

The skull (figs. 534-536) lacks a part of the palatal region, the occipital condyle, and the
right otic region. The lower jaw is so closely cemented in its place that it is thought best not to
attempt to remove it. We are therefore unable to determine the arrangement of the ridges and
grooves of the masticatory surfaces. There are, however, no reasons for believing that the
species does not belong to the genus Testudo.

TESTUDINID&. 413

The length of the skull, from the snout to the hinder border of the exoccipital near the
condyle, is 50 mm. To the occipital condyle the length was from 3 mm. to 5 mm. more. The
width, measured over the auditory chambers, is 40 mm. Seen in profile, the upper surface of
the skull is convex from the snout to the base of the supraoccipital spine. The interorbital
region is 12 mm. wide. The zygomatic arch is 6 mm. wide; the postorbital arch, 5.5 mm. wide.
The orbits are nearly circular, the diameters being 15 mm. The nasal opening is 12 mm. wide.
The premaxille project considerably beyond the anterior border of the prefrontals. The
longest diameter of the auditory chamber is 11 mm.; the shortest, 8 mm. The width of the
hinder pterygoid region is 12 mm. A prominent, but rather obtuse, ridge occupies the middle
of the palate. The sutures between the various bones can not be satisfactorily determined.

530.

Fics. 536-538.—T estudo peragrans. Skull and shell of type.

536. Skull, left side. 1. 538. Plastron. X}.
537- Shell, right side. 4. per. 1, first peripheral; /yo, hyoplastron;
hypo, hypoplastron; «xrph, xiphiplastron.

Altho the shell is damaged so that little that is satisfastory can be learned regarding the
neural and costal plates and the costal scutes, the general form of the carapace and plastron are
well presented. The carapace (fg. 537) is broad, truncated in front, broadly rounded behind,
and quite convex. The hinder third is considerably higher than the middle and front portions,
and the descent posteriorly and over the inguinal notches is quite abrupt. It is possible that
this is due to some extent to distortion during fossilization, but there is no evidence of this.
The length of the carapace is 320 mm.; the width, 280 mm. The free borders in front and
behind are acute; but the peripherals thicken rapidly from the border, the second reaching a
thickness of 20 mm.; the tenth, a thickness of 25 mm.

As stated, the characters of the neurals can not be determined. The costal plates are alter-
nately wider and narrower, the distal end of the fifth being 45 mm. wide, that of the sixth 30mm.
The pygal is convex in all directions, on its hinder, or upper, surface. It is 36 mm. high on the
midline, 54 mm. wide above, 28 mm. wide along the free border. Its upper border is excavated
to receive the hinder suprapygal.

Little can be learned regarding the epidermal scutes.

Large portions of the plastron (fig. 538) are missing. The anterior lobe is go mm. long;
150 mm. wide at the base. The epiplastral lip is very prominent, projecting 30 mm. beyond

414 FOSSIL TURTLES OF NORTH AMERICA.

the ends of the gulo-humeral sulci. It is truncated in front, with a slight median notch. The
median and the gulo-humeral sulci run in deep valleys in die bones. The width of the lip is
66 mm. at the base, and it diminishes slowly toward the tip. On the upper side the lip thickens
until it reaches 26 mm. in thickness. This is then suddenly reduced. The gular scutes are
57 mm. long on the midline. The entoplastron is missing. The bridge is 127 mm. wide. The
hinder lobe ts 148 mm. wide at its base. The hinder end of it is missing.

By its prominent epiplastral lip this species suggests 7. thomson: of the Oligocene of South
Dakota. However, it is noted that, Judging both from the relative sizes of the skulls and of the
common parts of the plastra, the lip of 7. peragrans would be over 100 mm. wide if the animal
had attained the size of the type of 7. thomson1; whereas the lip of the latter is only 82 mm.
wide. The skulls of the two species differ in important particulars. That of T. peragrans is
much more convex along the midline above, the orbits are more nearly circular, the interorbital
space is relatively narrower and the pterygoid region relatively wider.

Testudo vaga sp. nov.
Plate 19, fig. 5; text-figs. 579-547.

In the Cope collection of fossil reptiles belonging to the American Museum of Natural
History there are various remains which belong to the species here recognized. These were
collected for Professor Cope in 1880, by Mr. J. C. Isaac, from what are probably lower Deep
River deposits, 1 in the vicinity of Laramie Peak, Wyoming.
These remains belong to at least three individuals.

The most important of these specimens consists of many
fragments of the carapace, the nearly complete plastron, the
nearly complete shoulder-girdle, considerable portions of the
pelvis, the entire right femur, all of the left femur except the
distal end, the proximal ends of the tibia and fibula, nearly
all of the cervical vertebra, and a few of the caudal vertebrz.
The catalog number of this individual is 1327.

The plastron (fg. 539) has a length of 381 mm. The
length of the anterior lobe is 110 mm.;_ the width at the base,
195 mm. The front terminates in a lip which closely resem-
bles that of T. niobrarensis Leidy, altho it does not project
quite so prominently. As in the case of Leidy’s species, the
hinder portion of this lp, on the upper surface of the plas-
tron, is deeply excavated. The width of the lip from outside
to outside of the gular scutes is 80 mm. In the midline there
is a notch which is deeper than in 7. niobrarensis, as shown in
Leidy’s type. The lip of another specimen, No. 1326, has the
hip about as it is in Leidy’s figure. The upper surface of the
lip slopes upward and backward about 50 mm. to a rounded
edge. Beneath this edge is the excavation referred to above.
The greatest thickness of the lip is 25 mm. The hyoplas-
trals are 80 mm. long at the midline; the hypoplastrals, 105
mm.; the xiphiplastrals, 68 mm.

BiG. bi9-"Temiivonea. Mie The entoplastron is rhombic, 68 mm. long, 74 mm. wide.
1” No. 1327 A. _N. H. The bridge of No. 1327 1s 175 mm. wide. ;

The hinder lobe of the plastron has a length of 86 mm.,
and a width, at the inguinal notches, of 185 mm. It is notcht behind. At the base the outer
face of the hypoplastron rises in a nearly perpendicular wall 28 mm. high. From the
inguinal notch the wall diminishes rapidly in height and the outer face comes soon to look
upward and outw ard. The inner face, at the notch, Is concave.

The gular scutes have an antero-posterior extent of 60 mm. in the midline, and they en-
croach on the entoplastron 23 mm. The gulo- humeral sulci are about 28 mm. long on the
upper surface of the epiplastra, being thus about one-third of the width of the lip at the base.
The humerals meet along the midline 57mm. The sulcus limiting them behind is somewhat

Y
rs

TESTUDINID&. 415

convex backward. The pectorals occupy 50 mm. of the midline. ‘The sulci bounding them
behind are rather strongly convex forward. The abdominals are large, joining along the
midline for a distance of 115 mm. The femorals and the anals have about the same fore- -and-
aft extent, 40 mm.

The fragment of the carapace of the type individual has not been freed from the closely
adhering matrix.

In fife collection made by Mr. Isaac there is a specimen of a rather small individual, No.
1326, which furnishes a considerable portion of the carapace (plate 19, fig. 5), as well as the
characteristic parts of the plastron. All fhe neurals are repre-
sented in whole or part, and in the same way are represented
Neural. Length. = Width. most of the costal plates. The dimensions of the neurals are
shown in the table.

The first neural is broader behind than in front, and there 1s

1 31 24

2 az 33 on its anterior end a prominent boss. The second and fourth
: ee i. neurals are octagonal. The third is represented by only a part;
5 17 30 but it was doubtless quadrangular, with the lateral borders con-
: as 32 vex. The fifth is hexagonal and short. The sixth is hexagonal,
f < a with the antero-lateral sides longer than the postero-lateral; while

the seventh is hexagonal, with the antero-lateral sides shortest.
The eighth is hexagonal and elongated fore and aft.

The costals of this species are strongly modified as regards their width. The third articu-
lated with the second, third, and fcurth neurals. It has a proximal width of about 30 mm.
while its distal end is only 16 mm. wide. The fourth is very narrow at its proximal end, ik
it rapidly increases in width, being distally 43 mm. The fifth costal articulates with the
fourth, fifth, and sixth neurals; is 28 mm. wide proximally and 15 mm. distally. The sixth is
17 mm. wide proximally and considerably wider at the distal end. The costals are markt on
their distal halves with grooves and ridges, produced by the growth of the scutes.

The first vertebral scute had a width of 50 mm. at the anterior end and about 45 mm. at
the hinder end. The third has been 66 mm. wide at the middle of its length; the fourth, 53 mm.

Another specimen, brought from the same region by the same collector, had a carapace
about 330 mm. long. But little of the plastron is present. The carapace is crusht and various
parts are wanting. The number of this individual is 2894. This carapace is peculiar in having
the fourth neural hexagonal, instead of octagonal. The sixth costals expand distally, being
there 40 mm. and 22 mm. proximally. The seventh costals are narrow, 21 mm. proximally,
14 mm. distally. The ninth peripheral had a thickness of 11 mm. The anterior vertebral
scute had a width of 78 mm., while the fifth was 122 mm. wide.

All the vertebra of the neck of the type specimen (fig. 540) are present except the first
and second. On comparison with the corresponding vertebre of a specimen of 7. radzata
whose plastron is two-thirds as long, it is found that the neck of J. vaga was relatively shorter
than that of the 7. radiata, but a centra are in size proportionally broader. There are
some differences in the zygapophyses worthy of note. In 7. rad:ata, the prezygapophyses of
the sixth cervical rise to a height of 10 mm. above the lower border of the centrum, and the
zygapophyses measure only 4 mm. each across the articular surface. In 7. vaga these prezyg-
apophyses rise to a height of 20 mm. and are II mm. across. The postzygapophyses of
the eighth cervical of 7. rad:ata have a length of 7 mm.; those of T.vaga a length of 22 mm.,
a difference out of all proportion to the sizes of the two animals. The cervicals of the latter
are in fact as large as those of a Chelydra of the same size.

Herewith are furnisht figures of the scapula and the coracoid of the left side (figs. 541,
542). These parts do not differ in any important way from the same bones of Gopherus
polyphemus, altho they are proportionally stouter. The coracoid is 64 mm. long and 61 mm.
broad at the inner end. The neck of the bone is 14 mm. wide.

The vertebral end of the scapula is missing, so that the length can not be stated. Above
the glenoid cavity the bone is much comprest. The comprest procoracoid process (fig. 541)
has a length of 60 mm., measured from the center of the glenoid cavity.

The humerus (fig. 543) resembles closely that of Gopherus polyphemus, altho stouter in
build, resembling in this respect that of J. radiata of Madagascar. As a portion of each of

416 FOSSIL TURTLES OF NORTH AMERICA.

the humeri is missing the length of the bone can not be accurately determined, but it must
have been close to g5 mm. The head and the radial and the ulnar tuberosities do not differ
in any important degree from those of living species of Testudo. At the distal end the radial
fossa is deeper than in any species of Testudo at hand. The radial border is reduced to a
sharp edge and this is perforated by the ectepicondylar foramen.

The individual No. 1327 furnishes a nearly complete pelvis (figs. 544, 545), no part being
unrepresented except the proximal ends of the ilia and the processes extending backward
from the ischia. In general, the pelvis resembles closely that of G. polyphemus. Measured
from side to side at the upper border of the acetabula, the width was about 120 mm.; from

Sgt “545.
Fics. 540-547.—T estudo vaga. X}. No. 1327 A. M.N. H.

540. Fourth to eighth cervical vertebra. 544. Pelvis, seen from below.

541. Left scapula, showing glenoid fossa and articulating sur- 545- Pelvis, left side. 1/, lium; isch, ischium; pub, pubis.
face for coracoid. 546. Right femur, dorsal surface.

542. Left coracoid. 547- Right femur, tibial border.

543- Right humerus. Probably too great space between parts.

the hinder border of the ischium to the front of the pubis the distance is about 58 mm. The
ium had a total length of approximately 70 mm. Its upper end was expanded, and its
posterior plate-like process of bone is directed outward. In this respect it resembles the
species of Testudo at hand.

The ischium measured 50 mm. from the center of the acetabulum to the midline. From
the median suture the hinder border runs directly outward until the processes are reacht on
which the ischia rest in contact with the plastron. These appear to have had their median
edge about 17 mm. from the midline, and to have been about 13 mm. wide. There appears to
be much variation among the various species of Testudo in respect to the position of these
processes. In G. polyphemus and T. radiata they are placed far outward toward the acetabula;
in 7. tabulata, they are much nearer together.

The angle made by the symphysis of the ischia with the symphysis of the pubis, measured
on the upper surfaces of the bones, is very large, about 120°, being greatly like that of
T. radiata. In Gopherus polyphemus it is not much more than go°. From the point of articu-

TESTUDINID&. 417
lation of the pubis with the ischium, near the midline, to the anterior tip of the pubis is 39 mm.
The lateral pubic processes are stout, and appear to have been directed less strongly outward
than in any of the species of Testudo named above. Where it forms the anterior boundary of
the ischio-pubic foramen, the pubic bone is beveled off above, being in this respect like that of
Gopherus polyphemus.

The femur (figs. 546, 547) is strictly like that of Testudo, since the greater and the lesser
trochanters are united by a high ridge. This converts the fossa which lies between the tro-
chanters of the Emydide i into a pit. So far as the materials at hand indicate, this pit is much
deeper in T. vaga than in Stylemys nebrascensis. The two trochanters rise to the same level,
not quite to that of the head of the femur. On the distal end of the bone, a sharply defined
ridge separates the condylar surface for the tibia from that of the fibula, a condition that the
writer has not observed in Testudo. In Stylemys nebrascensis this ridge is still better
developt.

The scantiness of the materials from which Leidy’s Testudo niobrarensts is known makes
it dificult to distinguish it with certainty from the species here described. Since the two belong
apparently to very Saificnent levels the probability is great that they are not identical. The lip
of Leidy’s species appears to project further beyond the general outline of the anterior lobe
and the length of that part of the gulo-humeral scute that lies on the upper side of the epi-
plastral is shorter than in 7. vaga, one-fourth the width of the base of the lip instead of one-
third. From the younger specimens of 7. oshorniana it differs in the great antero-posterior
extent of the pectoral scutes and in the strong differentiation of the costal bones.

Testudo inusitata Hay.
Plate 68, figs. 1, 2.

Testudo tnusitata, Hay, Ann. Carnegie Mus., tv, 1906 (1907), p. 18, plates in, iv.

This name is applied to a specimen which was collected by Mr. Earl Douglass, near
Canyon Ferry, Broadwater County, Montana. The horizon is regarded as being that of the
Deep River. The specimen is a shell, the right side of which is missing. The catalog number
is 311.

The shell is convex above. The outline in front and behind is rounded. The peripherals
flare slightly over the limbs. The pygal is missing. The length of the carapace is 265 mm.;
the width is 200 mm. The nuchal is 60 mm. long, 47 mm. wide in front, 65 mm. where widest.
The first neural seems to have been 4-sided. The second to the sixth are hexagonal. The
dimensions are given in the accompanying table.

Dimensions of neurals. Dimensions of costal bones. Dimensions of costal scutes.

Proximal Distal

No. Length. Width. No. No. Length. Width.

width. width.
1 35 26 2 29 38 1 45 71
2 26 35 3 29 18 2 50 75
3 27 37 4 v2 34 3 57 78
4 25 37 5 29 20 4 By es
5 26 37 | 6 19 33 5 50 75
6 28 36 7 17 17
7 24 22 t 16 32

The costal plates are alternately wider and narrower proximally and narrower and wider
distally. Their dimensions are shown in the middle table above.

The peripherals over the bridges are high, rising about 65 mm. above the level of the
plastron. The free borders of those in front and those ‘behind the bridges are acute.

The vertebral scutes are considerably wider than long. The preral borders are not greatly

angulated. The approximate measurements are shown above in tabular form.

The plastron has a length of 245 mm. The anterior lobe is 80 mm. wide and mm.

wide at the base. The epiplastral lip projects 25 mm. beyond the ends of the gulo- een
27

418 FOSSIL TURTLES OF NORTH AMERICA.

sulci. It is 58 mm. wide at the base and it narrows slightly toward the tip. The latter is
truncated. From its acute free borders the lip thickens rapidly, rising on the upper surface
until it attains a thickness of 21 mm. The thickening continues backward 37 mm. from the
front. The entoplastron is hexagonal, 49 mm. long and 65 mm. wide at the base. The bridge
is 105 mm. wide.

The hinder lobe is 53 mm. long on the midline, 65 mm. to the hinder ends of the xiphi-
plastra. The width at the base is 111 mm. The notch is 43 mm. wide. At the inguinal notch
the free border of the hypoplastron is 22 mm. thick, the outer face rising perpendicularly.
Further backward the thickness rapidly diminishes, so that the middle of the free border of
the xiphiplastron is acute and thin.

The gulars occupy 42 mm. of the midline, barely reaching the entoplastron. “The humer-
als are 55 mm. long, extending slightly behind the entoplastron. The pectorals occupy 15 mm.
of the midline. Their outer ends are greatly expanded. The abdominals measure 70 mm.
on the midline; the femorals, 25 mm.; the anals, 30 mm.

Much of the outer surface of both carapace and plastron are sculptured strongly by the
lines of growth of the epidermal scutes.

This: species presents the feature, unusual in TJ estudo, of having only hexagonal neurals.
It thus resembles Stylemys; but it differs from the known species of the eter in having a
prominent epiplastral lip.

Testudo farri sp. nov.
Plate 69, figs. 1, 2; text-figs. 548, 549.

A species of Testudo was collected in the Deep River formation, of Smith River Valley,
central Montana, in 1891, by a party from Princeton University. “This specimen has now the
catalog number 10486. Only the shell is represented. This has been considerably crusht
downward and a little toward the right side. Of the carapace there are missing all behind the
fourth neural and the fifth costals, as well as the first three peripherals of each Side: The plas-
tron is complete.

While this species resembles in many respects both 7. n1obrarensis Leidy and T. vaga Hay,

it is evidently specifically different from both.
An estimate, made on comparison with Gopherus polyphemus, indicates that the total
length of the carapace (plate 69, fig. 1; text-hg. 548) was originally about 310 mm. The width
was not far from the same. The nuchal

Dimensions of neurals. Dimensions of costal plates. bone 1S 55 mim. long and 74mm. wide. The

hrst, third, and fifth neurals are 4-sided; the

No. Length. Width. | No. Re see second, fourth, and probably the sixth are
. width, width.

octagonal. The dimensions of the bones
are shown in the table.

I 30 2 2 19 42 a ae ; é
5 a me A ae 55 The costal plates are differentiated, as 1s
3 26 34 4 18 38 common in the genus, so that the proximal
4 45 , 35 *3 ends are alternately wider and narrower.
J = LP)

The table shows the widths.
The fifth peripheral has a height of 61 mm.

The upper surface of the carapace is strongly imprest by the lines of growth of the
epidermal scutes. ‘The sulci are distinct. The t oundaies of the vertebrals are straight lines.
The nuchal scute is 15 mm. long and 7 mm. wide. The first vertebral is 54 mm. lone go mm.
wide in front; the second is 56 mm. long, 55 mm. wide in front, 72 mm. wide at the middle
of the length; the third is 55 mm. long, aad has a maximum width of 76 mm.

The plastron (plate 69, fig. 2; text-fg. 549) is 273 mm. long and 203 mm. wide. The
front lobe has a length of 70 mm. and a width of 134 mm. at ‘the base. The lip projects
only moderately beyond she curve of the lobe behind the gular sulci. Its anterior border is
but little convex and appears not to have been notcht. From one gular sulcus to the other
the distance is 62 mm. From the front of the entoplastron to the tip of the lip is 23 mm.
Lookt at from above, this lip extends backward a distance of 38 mm., then drops off abruptly
to the general level of the upper surface of the lobe. The ledge thus formed is deeply exca-
vated. The thickness of the bone at the hinder end of the lip is 32 mm. The entoplastron

TESTUDINID&. 419

is pyriform, pointed in front, broadly rounded behind. Its length is 60 mm.;_ its greatest
breadth also is 60 mm.

The hyoplastral bones join at the midline for a distance of 49 mm.; the hypoplastrals, a
distance of 70 mm.; the xiphiplastrals, a distance of 46 mm. The notch in the rear of the
plastron is 38 mm. wide. The hinder lobe has a length of 70 mm., and a width of 140 mm.
at the base. :

The gulars are, taken together, 58 mm. wide. They overlap on the entoplastron. The
humeral scutes are 40 mm. long on the midline; the pectorals, only 12 mm.; the abdominals,
86 mm.; the femorals, 40 mm.; the anals, 25 mm.

549

Fics. 548 AND 549.—Testudo farrt. Carapace and plastron of type: <4.
548. Anterior half of carapace. 549. Plastron.

The outer surface of the plastral bones is somewhat sculptured along the lines of growth
of the scutes. There were large inguinal scutes and their areas are strongly imprest with the
growth lines.

The present species comes from an earlier formation than that to which J. niobrarensts
is supposed to belong. The latter appears to differ in having a more projecting epiplastral lip.
What remains of the entoplastron indicates that this was relatively narrower and longer than
that of 7. farrz.

From T. vaga, which it resembles, this species is distinguisht by the much shorter union
of the pectoral scutes at the midline, 12 mm., instead of 50 mm. There are other differences.

T. osborniana has the union of the pectoral scutes still shorter than has T. farrt. The
entoplastron is of a different shape and the vertebral scutes are less angular.

This species is named in honor of Dr. M. A. Farr, of the department of paleontology in
Princeton University, Princeton, New Jersey.

Testudo emili# sp. nov.
Plate 70, figs. 1, 2.

The type of this species belongs to the American Museum of Natural History and bears
the catalog number 6135. It was found during the summer of 1906, by Mr. Albert Thomson
on Porcupine Creek, South Dakota. The beds in which it was found are the Lower Rosebud,
a part of the Lower Miocene. The shell only is present and of this the costals of the left side
behind the fifth are missing, also the peripherals behind the left seventh, the pygal, the right
eleventh peripheral, and the ultimate and penultimate suprapygals.

The length of the carapace (plate 70, fig. 1) was very close to 320 mm. The extreme width
is 255mm. The shell was high and vaulted and apparently highest toward the rear. The out-

420 FOSSIL TURTLES OF NORTH AMERICA.

line was truncated in front, broadly rounded behind. On the area of the first vertebral scute
is a prominent median ridge forming an elongated boss.

The nuchal bone is 73 mm. long, 63 mm. wide in front, 98 mm. where widest. The first
neural is 4-sided; all the others are hexagonal, thus resembling those of 7. imusitata. The
accompanying table gives the dimensions of these neurals, of some of the costals, and of the
vertebral scutes.

Dimensions of neurals. Dimensions of costal bones. | Dimensions of vertebral scutes.

. : = Width at Width at P Greatest
No. Length. Width. No. macalendt een eas No. Length. ath

I 48 32 2 33 ; I 77 gt

2 30 40 3 33 33 2 64 80

a 32 49 4 29 28 3 60 80

4 28 47 5 29 38 + 57 7

5 32 42 6 25 32 5 5st 110+

6 23 43

7 23 35

8 15 27

‘The costal plates are only slightly differentiated as regards the width of the upper and
lower ends.

The sulci are narrow and deeply imprest. The vertebral scutes are wider than long and
their sides are not greatly angulated.

The scutal areas of the carapace are more or less strongly grooved by the lines of growth
of the scutes. The plastron (plate 70, fig. 2) has a total length of 290 mm., or 273 mm. along
the midline, the notch in the rear being 17 mm. deep. The length of the anterior lobe is 95
mm.; its width at the base, 148 mm. From the axillary notches it contracts gradually to the
gulo-humeral sulci. The lip is 33 mm. long, 60 mm. wide, with nearly parallel sides. Its
anterior border is notcht at the midline and: slightly tootht laterally. On the upper surface
the thickening of the lip extends backward 44 mm. ‘and the thickness becomes 25 mm. The
entoplastron is 51 mm. long and 56 mm. wide. The bridge is 120 mm. long. The hinder lobe
is 140 mm. wide at the base and 75 mm. long to the extremities of the xiphiplastra.

The gular scutes are 40 mm. long on the aalines they lack 16 mm. of reaching backward
to the entoplastron. The humerals occupy 73 mm. of the midline; the pectorals, 17 mm.;
the abdominals, 83 mm.; the femorals, 34 mm.; the anals, 22 mm.

This species neces closely 7. imusitata of the Deep River beds of Montana. It differs
from that geologically later species in having a longer plastral lip and especially in the failure
of the gular scutes to reach the entoplastron. The femoral scutes are relatively wider than
those of the Montana species. The type of the latter has but seven neurals; the present
species has eight. In 7. inusitata the widths of the upper and lower ends of the costal plates
differ more ian in the species here described.

This species is dedicated to my wife, Mary Emily Hay.

Testudo pansa sp. nov.

Plate 71, figs. 1, 2; text-figs. 550, 551.

This very distinct and striking species was discovered by Mr. Barnum Brown, of the
American Museum of Natural History, in the Pawnee Creek beds of the Miocene of Colorado:
in 1901. The exact locality where the type and only specimen was found is near the line
between the states of Colorado and Nebraska, north of Sterling, Colorado. The number of
the specimen is 5869.

The form of the species is rather peculiar in the genus. It is broad, deprest, somewhat
rounded in front, and broadly rounded behind. The plastron is extremely flat. The upper
surface of the shell passes abruptly into the lower surface, the free border of the carapace in
front passing into a lateral carina on each side, and this again into the free border behind.

The total length of the carapace (plate 71, fig. 1; text-fig. 550) is 775 mm. The greatest
width is 690 mm. The elevation of the carapace above the plastron is now only 250 mm., and

TESTUDINID&. 421

it is probable that the shell has suffered little depression during fossilization. ‘The anterior
peripherals are slightly flared upward; the hinder peripherals not at all so. The curvature of
the upper surface is everywhere gentle. The species possesses unusually narrow peripherals.
The first has an extent, at right angles with the free border of the shell, of 65 mm. The sixth
rises from the lateral carina 146 mm. The eleventh measures from the free edge, at the suture
between it and the tenth, to the costal suture, 87 mm. ‘The inner thickening of the anterior
peripherals extends backward from the free border about 57 mm., and the thickness 1s about
27mm. The inner thickening of the hinder peripherals continues for about 75 mm. from the
free edge, and amounted to about 30 mm. The free edges of the carapace are everywhere
acute.

The nuchal bone extends along the border of the shell 118 mm. and backward along the
midline 127 mm. The forms of the neural bones may be seen from the figures. Most of them
are hexagonal, but the second and fourth are octagonal. The second and fourth costals are
narrow at their proximal ends, very broad at the distal. The third and fifth are narrow

Fics. 550 AND 551.—Testudo pansa. Carapace and plastron of type. £:

550. Carapace. 5st. Plastron.

distally and broad proximally, where they each come into contact with 3 neurals. The first
suprapygal has the usual bifurcate form, and comes into contact on each side with the eleventh
peripheral. The second suprapygal is small, extending along the midline 57 mm. The pygal
measures 52 mm. on the midline, 110 mm. along the free border.

The plastron (plate 71, fig. 2; text-fig. 551) 1s very broad and flat. The exact position
of the sutures between the plastral bones and the peripherals of the bridge can not be deter-
mined, but they are not far, if at all, mesiad of the sulci between the plastral and the margina
scutes. The length of the plastron in the midline is 715 mm.; to the extremities of the apices
of the xiphiplastra, 45 mm. more. The width of the plastron is about 580 mm. The anterio1
lobe has a length of 195 mm., and a width of 400 mm. at the base. The borders of the lobe are
acute. The anterior lip is narrow at the tip, very slightly notcht, and 148 mm. wide at the
gular sulci. Superiorly the lip thickens backward for a distance of 80 mm. becoming about

422 FOSSIL TURTLES OF NORTH AMERICA.

55 mm. thick. The posterior lobe is 173 mm. long to the apices of the xiphiplastra, and 1s 370
mm. wide at the base. The posterior notch is 110 mm. wide and 45 mm. deep. At the inguinal
notch the edge of this lobe forms a wall about 55 mm. high, having a rounded outer face and a
sloping inner face. Posteriorly the wall diminishes rapidly in height, so that the thickness at
the xiphiplastral apices is only 30 mm.

The entoplastron is rhombic in form, 156 mm. long in the midline, 195 mm. wide. The
hyoplastra meet along the midline for a distance of 176 mm., the hypoplastrals 156 mm., and
the xiphiplastrals 145 mm. ;

The nuchal scute is about 30 mm. long and wide. The marginal scutes rise to the sutures
between the peripherals and the costals. The supracaudal scute seems not to have been
divided in the midline. It has a width along the free border of
vie pais 200 mm. The vertebral scutes are very wide, especially those

ceute, | Eeseth. | ea behind the first. The table gives the dimensions.
The gular scutes extend backward on the entoplastron.
The humerals have an extent of 100 mm. along the midline.

I 160 160 : ata
: aa aie The pectorals are 73 mm. antero-posteriorly at the midline.
3 137 260 Beyond this they narrow for some distance, then expand greatly.
4 a pe The abdominal scutes meet along the midline a distance of
5 165 227

207 mm.; the femorals, 100 mm.; the anals, 75 mm.
The pelvis is preserved in position. It has a stout lateral
pubic process. The tubera ischii are conical, and their apices are 105 mm. apart.

Testudo osborniana Hay.
Plates 72-75; text-figs. 552-562.

Testudo oshorniana, Hay, Ann. N. Y. Acad. Sciences, XVI, 1905, p. 312.

The type of the present species was secured in 1901, by Mr. Barnum Brown, near the line
between Colorado and Nebraska, north of Sterling, Colorado. The locality is in the latter
state. The deposits affording it belong to the Miocene, and are known as the Pawnee Creek
beds. The specimen belongs to the American Museum of Natural History, and bear its
catalog number 5868. It consists of a complete shell, the skull (lacking the lower jaw), the
pelvis, both hinder limbs nearly complete, and the tail. From the deeply concave plastron it
is concluded that the animal was a male. The total length of the carapace is 775 mm.

The skull (figs. 552-554) is rather long and narrow a a Testudo, and the ees are moder-
ately thick and heavy. The sides of the skull are parallel from the squamosal processes to the
front of the orbits, beyond which they converge with nearly straight outlines to the rounded
snout. Seen from the side the upper ‘outline of the skull is concave behind the orbits, above
and in front of them moderately convex.

The following are some of the dimensions of the type skull:

Millimeters. Millimeters.
Snout to the end of the supraoccipital process.. 129 Width of interorbital space : ; 2
Snout to occipital condyle............. 119 Width of nasal opening transversely... 2
Width at the base of the quadrates. . . 81 Antero-posterior diameter of the orbit 2
Width at the hinder end of the maxilla 79

The height of the skull from the cutting-edge of the maxilla to the upper surface of the
frontals is contained in the length from the snout to the condyle 2.8 times.

The prefrontals meet along the midline a distance of 23 mm., and this is also the length of
the suture between the frontals. The orbits are subquadrilateral. The long axis, 30 mm., is
directed from the prefrontal border backward, outward, and downward. The jugal arch has a
width of 16 mm. The maxilla descends from the floor of the orbit a distance of 18 mm.
The cutting-edge is concave, especially posteriorly, and is rather coarsely dentated. The
squamosal processes are not laterally comprest, but swollen, especially on the inner side; and
the outer, upper border rises but little above the upper surface of the paroccipital.

The antero-posterior extent of the otic region, measuring across the paroccipital and
prootic, is 33 mm. and contained in the length of the skull to the occipital condyle 3.6 times.

TESTUDINID. 423

The palatal region (fig. 553) is highly vaulted, the median fossa having a width of 23 mm.
The narrowest portion of the pterygoids is also 23 mm. wide. On the outer border of each
pterygoid 1s a distinct ectopterygoid process. The vomer 1s well archt upward, and is traverst
by a longitudinal ridge, which is sharp in front, but rounded behind. The masticatory surface
of the maxilla presents 2 longitudinal ridges and 2 deep grooves. The outer and principal
ridge is separated from the descending cutting-border of the jaw by the wider groove. ‘This
ridge 1s received in the groove of the mandible. The ridge is sharp, slightly tootht, and runs
forward and inward to the premaxilla, then directly forward on the latter bone to its cutting-
edge. The inner ridge is low, flat, and rather broad, especially behind. It occupies the inner

Fics. 552 AND 553-—T estudo oshorniana. Skull of type. 2.

552. Upper surface. 553- Lower surface.

border of the maxilla. There is no ridge occupying the midline along the symphysis of the
premaxilla; hence this species can not be regarded as a Gopherus. The masticatory ridges
of the right and left sides are separated by a deep longitudinal groove. ‘This is interrupted only
by a rough eminence on the hinder ends of the premaxilla. The cutting-edge of the maxilla
descends much below the roof of the mouth.

In many respects this skull resembles that of 7. gilbert:; but, as shown under that species,
T. oshorniana has a much broader jugal arch, a more elongated otic region, a squamosal region
less comprest laterally, and a more heavily constructed skull.

The carapace is high and swollen, resembling in general form the shell of 7. radiata, of
Madagascar. The following table presents the dimensions of the carapace and plastron.

Millimeters. Millimeters.
Total length of carapace... . 775 Width of anterior lobe 425
Width of carapace. 555 Length of anterior lobe 210
Height of shell... . -. 430 Width of posterior lobe 355
Length of plastron : 710 Length of posterior lobe . 180

The carapace (plate 72; text-figs. 555, 556, 557) is truncated in front, broadly rounded
behind. The sides overhang the borders of the plastron. The nuchal and the anterior periph-
erals are flared upward. The ninth and tenth peripherals are also somewhat flared; the
eleventh and the pygal are nearly vertical. The free borders of the carapace, both in front and
behind, are acute.

424 FOSSIL TURTLES OF NORTH AMERICA.

The nuchal bone occupies 140 mm. of the free border and is 182 mm. wide at the widest
portion; 141 mm. long in the midline. Its greatest thickness at the midline is 36 mm. The
bridge peripherals are very high, about 230 mm. and therefore nearly as high as the costals,
the fourth of which is 257 mm. high. The thickness of the inner surface of the hinder periph-
erals increases to about half of the
height and is then suddenly reduced,
the maximum being about 23 mm.
The pygal is 80 mm. wide at the
free border, 114 mm. at the upper
border and 83 mm. high in the mid-
line. Its thickness at the midline is
24mm.

The second costal is 70 mm. wide
near the proximal end, 88 mm. at
the distal end. The third is 100 mm.

Fic. 554-—T estudo osborniana. Skull of type, wide at the proximal end, 70 mm. at

right side. 3. the distal end. The fourth has a

width of 68 mm. at the proximal end, go at the distal end. The fifth has the dimensions respec-

tively 83 mm. and 76mm. The sixth is 73 mm. wide proximally, 102 distally. The seventh is

48 mm. across the proximal end, 93 across the distal. It is seen from these figures that, as

in other species of Testudo, the costals, omitting the first, are alternately widened and nar-

rowed proximally, whilst alternately Rantewed and widened at the distal ends. The degree
of differentiation among the costals is, however, less than is usual in the genus.

The neural bones have the dimensions given in the table below.

The first suprapygal is 93 mm. long at the midline, 40 mm. wide at the upper end, and
183 mm. at the lower, the bone having the usual notch in its lower, or hinder, border. The
second suprapygal has a median length of 6g mm. and a width of g2 mm.

The vertebral scutes are large, the dimensions being shown in the table.

The nuchal is small, being 27 mm. wide at the anterior end, 11 mm. at the hinder end, and
52mm. long. The supracaudal scute is 225 mm. from side to side, and has a height of 102 mm.

The anterior lip of the plastron (plate 73;

Dimensions of neurals. Dimensions of vertebrals. text-fhg. 550) is greatly developt. At its base,

7 = where the sulci bounding the gular scutes

No. Length. | Width. | No. | Length. | Width. | cross the free border, the width of the lip is
205mm. The front of the lip is slightly notcht
in the midline. From this the subacute

I TI 67 I 163 187 cs

2 3 112 2 iso | 185 border curves round to the base of the lip.
3 70 103 3 133, | 203 From the free border the bone thickens rap-
: fe a nS ie idly backward for a distance of 135 mm. until
6 61 95 : : — it reaches a thickness, in the midline, of 75
d se | mm. The thickness then drops suddenly off

| to that of the greater portion of the plastron.
The escarpment of bone thus formed is very
slightly excavated. ‘The free border of the anterior lobe behind the lip is acute.

The hinder lobe of the plastron has a wide shallow notch behind. The width of the notch
is 130 mm.; its depth is only 23 mm.

The entoplastron is 153 mm. fore and aft, and 210 mm. wide. The hyoplastra extend
140 mm. along the midline; the hypoplastra, 160 mm.; and the xiphiplastra, 127 mm. The
free border of the hinder lobe is subacute. From the border the bone thickens rapidly. ‘Toward
the inguinal notch the border rises and forms a wall which reaches a height of 80 mm. Its
summit is narrow, and the slope on the mesial side is abrupt.

The gular scutes occupy 170 mm. of the midline; the humerals, 100 mm.; the pectorals
only 10 mm.; the abdominals, 255 mm.; the femorals, 76 mm.; and the anals, 85 mm.

The pelvis is in its natural position and is complete, except that the anterior processes
of the pubes are missing. The processes on the hinder border of the ischia resemble those of

TESTUDINIDZ. 425

T. radiata, except that they are relatively thinner, the hinder border is sharp, and they lie in
a plane which passes thru the acetabula. The distance between the points of these processes
is 130 mm. The upper surface of the ischia, in the midline, is deeply excavated. The process
on the under side of each ischium which rests on the plastron is 55 mm. wide, and rather flat
below and behind.

The limbs of this tortoise were of the short and heavy type, like those of T. radiata, of
Madagascar. Fig. 558 shows the left femur seen from the hinder, or ventral, surface. The
length is 144 mm. The surface of the bone is strongly imprest for the insertion of muscles.
The head is large, its greatest width being 58 mm., and the distance from the uppermost
border, when in position, to the lower surface of the ridge joining the trochanters is 73 mm.
The notch separating the greater from the lesser trochanter is very shallow, as is likewise the
intertrochanteric fossa. The shaft is comprest at the middle of the length, the perpendicular

1

Fics. 555 AND 556.—Testudo oshorntana. Carapace and plastron of type. 2.

555. Carapace. 556. Plastron.

diameter, when the femur is in its natural position, being 30 mm., the horizontal diameter
22mm. The epicondyles are strongly developt. The diameter of the bone through these is
64 mm. The condyles join each other by a strongly developt groove.

As is to be seen from fig. 559, the tibia (t7b) is stout. Its length is 100 mm.; the diameter
through the tuberosities at the proximal end is 45 mm. The diameter of the shaft between the
middle and the distal thirds is 18 mm.

The fibula (fig. 559, 2b) is 88 mm. long and 20 mm. broad at the proximal end, and 27 mm.
at the distal end.

The bones of the tarsus and toes are somewhat disturbed and some are missing. The
fibulare (fig. 559) evidently coalesct with the astragalus to form the astragalo-calcaneum.
The articular surfaces for the tibia and fibula are strongly concave, and their boundaries are
sharply markt. This bone measures from one side to the other 42 mm. Distally there is on
the tibial side a long convex articular surface for those tarsals of the second row which support
the first, second, and third digits. On the fibular side is a deeply concave surface for the
fourth tarsal of the second row.

420 FOSSIL TURTLES OF NORTH AMERICA.

All the tarsalia of fig. 559 (2, 3, 4, 5, of the second row) are present in the right foot
except the first; but this is present in the left foot. The first and the fifth are largest. By its
inner border the fifth articulates with the fifth tarsal; and by a part of the lower border, with
the fourth metatarsal. The metatarsals of the first and second digits and the first phalangeal
of the second digit are missing; but these are present in the left foc The distal, claw-bearing
phalanges are relatively long, that of the first digit being 27 mm. long; that of the second, 35
mm.; that of the third, 40 mm.; and that of the our, 37 mm. Back claw phalange is there-
fore as long as, or longer than, ‘the remaining phalanges, together with the metatarsal of the
same digit. In size acd form the distal phalanges reeomible those of Gopherus polyphemus.

The terminal portion of the tail is greatly expanded. This portion is 75 mm. long and
appears to consist of 5 vertebra. The leteral processes of these vertebra are lengthened, so

557:
Fics. §57 AND 558.—Testudo oshorniana. Shell and femur of type.
557. Carapace, side view. X¢#. 558. Left femur, ventral surface. 4.

that a broad Hat beaver-like paddle is produced. Its greatest breadth is 85 mm. The terminal
vertebra, 10 in number, of G. polyphemus have their lateral processes similarly lengthened,
but in this case the processes are distinct, true caudal ribs,

This tortoise possest the same kind of supplementary armor that we have found in 7.
orthopygia. ‘The skin of the bottoms of the feet, of the lower leg, of the hinder part of the
thigh, the tail, both on the upper and the lower sides, and probably also of the anterior limbs
supported an armor composed of bones of various sizes. These bones doubtless lay each
beneath a horny scale such as we see protecting the limbs of many of the living species of
Testudo and of other genera of turtles. Fig. 559 represents the dermal bones, as well as the
foot bones of the right hind foot. The dermal bones evidently belonged to the bottom of the
foot and the hinder portion of the lower leg. The deeper surface of these bones is seen, as is
indicated by the pitting. The external surfaces, where seen, are smooth. In the figure the
tarsal bones and the phalanges are lettered. It will be observed that the dermal bones of the
foot and the heel are larger than those further up on the leg. How far up on the leg they
extended is uncertain.

Fig. 560 shows the dermal bones which protected the upper surface of the tail and of the
hinder portions of the thigh. In the center of the mass is seen a considerable area consisting
of about a dozen bones closely articulated suturally. These overlie the expanded extremity
of the tail, of which the last centrum and its processes (fig. 560, 4, 4) are seen resting on the
hinder border of the carapace. On the left side of the fgure the dermal bones adjoining the

~~

TESTUDINID. 427

tail armor are larger than on the right side, altho they diminish in size outward. All these have
a smooth and flat surface, which is undoubtedly the exterior. At the extreme left border (fg.
560, B) appears a large pyramidal bone, with an approximately square base. No doubt this
represents a spur such as is seen on the hinder side of the thighs of many living species of
Testudo. The letter C of fig. 560 points to the corresponding spur of right side.

On the right side of the figure the bones are seen to be rough and pitted, and the surface
is very convex. This is, double the inner surface, which line become exposed by a flap of
the skin of the thigh falling inside out over the skin nearer the tail. The spur of this side is seen
below this layer of bones. A portion of the tail nearer its base is present, and this bears on its
upper surface a layer of dermal bones in their natural position.

No portions of the anterior limbs are present.

A second specimen (plate 74) of this species was found in the same beds and same locality
in 1g01 by Dr. F. B. Loomis, of Amherst College. This specimen now bears the number
5870 of the American Museum. At the time of its entombment this specimen was doubtless

559- 560.

Fics. 559 AND 560.—Testudo oshorniana. Right hind leg and tail of type. 3.

559- Right hind leg. astc, astragalo-calcaneum; fib, fibula; mta. 3, mta. 4, third and fourth metatarsals; t1b, tibia;
I, II, 111, IV, the first to fourth digits; 2, 3, 4, 5, tarsal bones of the second row.

560. Armor of bones in the skin around and onthe tail. 44, extremities of the transverse processes of the last caudal
vertebra; B, left lateral spur; C, right lateral spur.

uninjured, but thru the weathering of the matrix within a short time before its discovery,
the region of the left hind leg was exposed and this limb is now missing, as well as a part of
the carapace near it. The terminal phalanges of the left forefoot also are wanting.

It appears probable that this individual perisht while hibernating. The head is with-
drawn within the shell, so that the tip of the snout is at a distance of g5 mm. from the anterior
border of the carapace. The mght foreleg is placed so as to close the shell neatly on that side.
The left foreleg is advanct slightly. The mght hind leg is withdrawn, so as to shut in its
side of the gap between the upper and lower portions of the shell. The broad armored tail
filled up the space between the two hinder legs.

The skull, the cervical vertebra, and some other bones give evidences of having been
considerably softened at some time after death.

425 FOSSIL TURTLES OF NORTH AMERICA.

The length of the carapace of this individual is 930 mm.; the greatest breadth, 690 mm.
Thru pressure of the overlying matrix the carapace 1s somewhat ‘deprest, so that the form
of the shell is best shown by dhe type of the species. The length of the plastron is 840 mm.
The anterior lip projects hardly as much as in the type, a erolles individual.

This specimen displays beautifully the armor of the forelegs. A closely compacted layer
of bony nodules was imbedded in the skin, from the bases of the claws to the middle third of
the upper arm bone. Along the ulnar side of the forearm is a row of larger nodules, one of
which appears to have been formed by the co-ossification of two originally distinct bones.
Some of the larger nodules appear at the elbow j joint. Above this the nodules decrease in size.
The palm of the hand was protected by a layer of bones of moderate size. Beyond the bones
forming the armor of the foot projected the five claws.

The hind foot possest a sole of bony nodules, but those bones shown in the figure near the
claws are the phalanges. “Toward the hinder border of the foot the nodules hecome larger
and the two hindermost project as great spurs. Such bony spurs armed with a covering of
tough horn would doubtless offer some discouragement to any carnivorous animal that might
have sought entrance in that region. Perhaps also these spurs would be of assistance to the
animal in walking over a rocky surface. Another great spur lies alongside the fourth claw
phalange and ceraulenee a fifth claw. In the type specimen, No. 5868, the fifth tarsal bone of
the second row shows an articular surface for a rudimentary metatarsal.

The tail presents in general the same features as that of the type specimen. The central
nodules are still more intimately consolidated. The lower border of the armor covering the
tail was apparently 140 mm. wide, and was bordered by about 10 nodules, which increase in
size from the midline each way. The outer 3 are pointed. It was probably just outside of
these that the armor of the tail past into that covering the thighs. In this specimen this armor
is continued two-thirds the distance to the knee-joint. On each side of the tail are two very
large and pointed spurs, such as we find on the thigh of various living species of T estudo; but
these in 7. osborniana appear to have been placed nearer the tail cian usual. In the type
specimen there appears only one spur on each side of the tail.

The scapula and its proscapular process are slenderer than those of T. impensa. The
type of the latter has a carapace only a few millimeters shorter than the specimen of 7. oshorn-
iana here described. The table presents the dimensions of certain parts of the two species.

Testudo Testudo
Measurements taken. 5 5
impensa. osborniana.
Diameter of procoracoid process at middle of length:
Greater.....-. ehgoicereratatiuals : ae : 43 oi
Smaller 27 23
Length of coracoid fam Plesoid t to median border 155 145
Length of median border of coracoid............ 145 16s
Length of humerus from middle of nea to distal al 240 240
Least diameter of shaft.............- 41 38

The ulna is hidden beneath the armor. The right radius is exposed sufhciently to permit
determination of the length. This amounts to 135 mm.

The skull of this individual was considerably macerated about the time of burial; the
bones have been more or less fractured and sometimes slightly displaced. One important differ-
ence is shown between it and the skull of the type; namely, the interorbital space is much
broader. Inthe type this space is 28 mm. wide; in the one now described it 1s 43 mm. Ordi-
narily this difference would be regarded as indicating a distinct species. Here we have prob-
ably a difference due to sex. aGhe type 1s almost certainly a male, as is shown by the very
concave plastron. The other individual has a very flat plastron and was probably a female.

The cervical vertebra are all present. The elements of the first are hidden beneath the
supraoccipital process. The second has been damaged so badly that little can be said regarding
it, but the posterior end appears to have been concave. The third seems to have had a convex
anterior end. Its posterior end is concave. The fourth has the anterior end convex. The con-
tiguous ends of the fourth and fifth are injured, but it seems pretty certain that the hinder end
oF the fourth was convex and the anterior end of the fifth concave. The sixth is concave in

TESTUDINID&. 429

front, convex behind, with two distinct surfaces, forming a ginglymoid joint. The seventh has
both ends concave. The eighth has a ginglymoid concavity in front, and a rounded head
behind. The dorsal vertebra have all been destroyed.

The pelvis of J. osborniana appears to have been narrower than that of 7. smpensa, the
width of the former, taken across the pubes from the lower border of one acetabulum to that
of the other, being 172 mm.; in the latter species, 195 mm.

Besides the large individual described above, Dr. Loomis discovered several others of
smaller sizes. One of these, No. 6080, has a carapace 400 mm. long and 335 mm. wide.
Another has the carapace 266 mm. long and 218 mm. wide. The shell is complete and only
slightly distorted. It is numbered 5871 and is one of five which were piled closely together.
Two of these were too much injured to be worth saving. These shells appear to have
drifted to their place of burial, for there were no remains of other bones of the skeleton with
a at nt ae 1 ae iE i cmetie * aile
/ e vA k i oe
7a ia toe B, “ ‘

/

—

4

-~ Pe
vA ~~ i

pai
es a ;
j >
—~2. _ > 9
i
(
~< | .
A ey ei : 562.
Pe - > _
= ie eee
. teat \
ss i —
er aaa 4 He i. |
~ See. eae Ne
x d Fi
“e a fae 2 ke ‘ ae
{ *y, ae
XN £ >
Nee “ a
be 2 “
BS 4 Pye
\ 2 <
x \ wa
ne ae j nN__7 =
— he | es eee

Fics. 561 AND 562.—Testudo oshorniana. Carapace and plastron of young individual.

<4, No. 5871 A. M. N. H.
561. Carapace. 562. Plastron.

them. No. 5871 furnishes figs. 1, 2, of plate 75; and text-hgs. 561 and 562. In form the
younger individuals differ from the adults in being more rounded in front, the angles at the
third peripherals not having yet been developt. The peripherals of the bridge region are not
so high relatively as in the adults.

The plastron of No. 5871 (text-fg. 562) has a total length of 253 mm. The anterior lobe
is 67 mm. long and 142 mm. wide at the base. The lip is 62 mm. wide at the base and is
slightly notcht in front. The upper surface is like that of the larger specimens. The bridges
are 125 mm. wide. The posterior lobe of the plastron is 60 mm. long and 130 mm. wide at the
base. It is broadly notcht behind.

A still smaller individual found by Dr. Loomis is numbered 5873. It furnisht a shell only
slightly damaged and not at all crusht, so that in it we have the form of the young. The shell
is high and tumid. The peripherals above the bridge and the distal halves of the costals are
ornamented with longitudinal grooves and ridges, which mark the growth of the horny scutes.
This, like the other younger individuals, has a low boss on the first neural bone.

430 FOSSIL TURTLES OF NORTH AMERICA.

This species differs from 7. undata Cope in that the posterior peripherals do not have a
strong recurvature outward and the internal thickening is much below the border joining the
costal bones. From T. flettiana, based on a pygal bone, it differs in not having the right and
left borders parallel, but div erging upward. The upper border is notcht for the second supra-
pygal. From 7. orthopygza it differs in having a more elongated skull, a broader plastral lip,
and the posterior peripherals less abruptly curved upward near their free border.

The front of the plastron of the younger specimens of this species bears considerable resem-
blance to the same part of T. nzobrarensis figured by Dr. Leidy (Cont. Ext. Vert. Fauna West.
Terrs., 1873, p. 225, plate ini, fig. 4). It appears however that the lip of Dr. Leidy’s specimen
projects farther beyond the points where the sulci on each side of the lip cross the border of the
plastron, about two-thirds of the lip extending beyond these points. In the specimens of T.
osborniana at least half of the lip is behind these points, and usually more of it. Only in the
type specimen is there half of the lip in front of the line joining the points referred to. In
Leidy’s species, moreover, the front border of the entoplastron falls behind the ledge formed by
the lip; whereas, in J. oshorniana the front of the entoplastron is slightly in fone of the ledge
of the lip. Dr. Leidy’s species almost certainly belongs to a different geological level.

Of this fine species, which has been named in honor of Prof. Henry F. Osborn, of the
American Museum of Natural History, there are, in the museum mentioned, spécimens which
give us a knowledge of the whole osteology and of various stages of growth.

n

~s

563. 564. 565.
Fics. 563-565.—Testudo arentvaga. Pygal and eleventh peripheral of type. 4.

563. Pygal, eleventh peripheral, and part of suprapygal.
564. Section of pygal and suprapygal along midline.
565. Section of eleventh peripheral at union with tenth.

Testudo arenivaga Hay.
Figs. 563-565.
Testudo arenivaga, Hay, Ann. Carnegie Mus., tv, 1906 (1907), p. 16, figs. 6-8.

The present species is based on a fragmentary individual which belongs to the Carnegie
Museum, Pittsburg, Pennsylvania. The catalog number is 1509. The remains were found in
1905, in beds reg papded as belonging to the lower Miocene formation. The locality 1s about
2 miles north of Agate Springs quarry, in Sioux County, Nebraska. The pygal and the eleventh
peripheral are selected for description.

The pygal (figs. 563, 564) has a height, from the free border to sulcus crossing the hinder-
most suprapygal, ‘of 112mm. The idea at the upper, or anterior, border is 102 mm.; at the
free border, 58 mm. The upper border is deeply notcht for the last suprapygal, the distance

TESTUDINIDA. 431

from the free border to the notch being only 83 mm. The thickness of the border which articu-
lated with the eleventh peripheral is 30 mm. The exterior surface of the bone is rather strongly
convex both from side to side and from above downward. ‘The inferior surface is concave
from side to side, convex from above downward. The free border is acute. In fig. 564 the
inferior or inner surface is that toward the left hand.

The portion of the posterior suprapygal remaining indicates that the width of this bone
was about 60 mm. It is 20 mm. thick.

The eleventh peripheral (figs. 563, 565) is narrow above, widening below. The height is
98 mm.; the width of the upper border, 45 mm.; that of the free border, 87 mm. The exterior
surface next the pygal is nearly plane; that near the tenth peripheral strongly concave up and
down, the free border here being considerably flared upward. Fig. 5651 is a view of the end of
the bone which joined the tenth ‘peripheral. The greatest thickness is 31mm. About 37 mm.
below the upper border of the bone the thickness 1s mather suddenly reduced. forming a shoulder
on the inner side of the bone. The upper border is only 13 mm. thick.

It is necessary to compare these bones with the corresponding ones of various other species
of Testudo.

They resemble most the pygal and the eleventh peripheral of 7. rmpensa. ‘The dimen-
sions of the pygal of the latter species are as follows: Height, 145 mm.; width above, 146 mm.,
width along the free border, go mm. It will be seen fiat. relatively to the height, the width is
greater. The exterior surface, too, is less convex in all directions. The elev Sieh peripheral of
T. impensa measures as follows: Height, 122 mm.; width above, 80 mm.; at the free border,
123 mm.

T. osborniana, type, has the pygal 110 mm. high; 113 mm. wide above; 80 mm. wide on
free border. It will be observed that the lower border is relatively considerably wider. The
outer surface is likewise considerably less convex than that of T. arenivaga. The eleventh
peripheral of 7. osborniana has a height of 105 mm.; a width of 66 mm. along the upper
border; and a width of 106 mm. alone: the free border. The two bones have fiereore quite
different proportions.

The pygal of 7. pansa is of a different form, being wider below than above, and not so high
as wide.

T. undata has the hinder peripherals more strongly flared upward than are those of the
present species. According to Cope the pygal, too, is fared upward toward the free edge.

Especially is it to be a teaica with 7. ede of the same beds. The type of the latter is a
much smaller individual. The table presents measurements of parts common to the two species.

Measurements taken. Hest ag Destudo
ede. arentvaga.
Height of pygal to lower border of suprapygal. : 45 83
Width of upper border of pygal ; 70 102
Width of lower border of pygal 43 58
Greatest thickness of pygal.. . 15 30
Height of eleventh peripheral . 45 98
Width of upper border of eleventh peripheral 12 45
Width of free border of eleventh peripheral 2 87

It will be observed that the width of the pygal of ZT. arenrvaga is less compared with the
height than in the case of J. ede. Again, the eleventh peripheral of 7. arenivaga is consid-
erably broader in comparison with fhe pygal than is the case with these bones in T. eda.
The differences in the proportions of the bones of the two species is well brought out by
making plots with the measurements given, those of 7. aren:vaga being divided by 2

Testudo impensa sp. nov.

Plates 76, 77; text-figs. 566-571.
The dry-land tortoise to which the above name has been given was discovered by Mr.
Albert Thomson, of the American Museum of Natural History, i in 1902, in the Loup Fork

Miocene deposits of Montana, a short distance above the mouth of the Madison River. The
locality isin Broadwater County. The number of the specimen is 5867. The parts represented

432 FOSSIL TURTLES OF NORTH AMERICA.

are the skull complete, the nearly complete shell, both shoulder-girdles, the left humerus, the
pelvis complete, 3 injured cervical and 4 caudal vertebra, and a quantity of dermal bones.

The individuals of this species appear to have reacht a large size, the length of the cara-
pace of the type being 922 mm. Their relationships were close to 7. oshorniana, as shown
both in the skull and the shell.

The skull (figs. 566-568) lacks most of one of the posterior lateral angles. There has
occurred some crushing and distortion of the prefrontal region. The skull is slightly broader
in proportion to its length than in J. osborniana. In the latter species the width is 68 per cent.
of the length to the occipital condyle, while in T. impensa it is 72 per cent. This small differ-
ence may disappear on the examination of other specimens. ‘The following are the principal
dimensions of the skull:

Millimeters. Millimeters.
Total length of the skull. 157 Width of palatal fossa. ; 39
Length to occipital condyle 138 Length of the mandible....... : 98
Width at the quadrates 97 Depth of mandible at the symphysis.... 21
Interorbital space. : : 38

The prefrontals meet along the midline 21 mm.; the frontals, 27 mm. The orbit is some-
what distorted, but its antero-posterior diameter is 34 mm. The width of the jugal arch appears

Fics. 566 AND 567.—Testudo 1mpensa. Skull of type. X34.

566. Upper surface. 567. Palatal surface.

to have been about 16 mm. The maxilla descends below the floor of the orbit 22 mm. The
cutting-edge, seen from the side, 1s convex in front, slightly concave posteriorly, but the con-
cavity seems to have been less thant in T. osborniana, and the bone did not terminate posteriorly
in such a prominent process as in the latter named species. This cutting-edge is irregularly
dentated, especially in front. The antero-posterior extent of the otic region, measured across
the paroccipital and the prootic, is 31 mm., being contained in the length of the skull to the
occipital condyle 4.45 times. The laeeral’ angles of the skull extend behind the occipital
condyle about 10 mm. In J. osborniana they extend but little beyond the condyle. The
portion of the skull in front of the postfrontals equals one-half of the length to the condyle.
In T. osborniana the portion mentioned equals only 0.45 of the length.

The nasal opening has a width of 30 mm. The prefrontals lack 27 mm. of coming to a
perpendicular from the front of premaxilla. In 7. osborniana the prefrontals lack only 10 mm.
of reaching this perpendicular.

TESTUDINIDA. 433

The roof of the mouth (fig. 567) resembles closely that of 7. osborniana. The outer ridge
of the masticatory surface is strongly developt and dentated. Anteriorly it continues forward
on the premanilla of its side; so that between the right and left ridges there is, in the pre-
maxillary region, a deep furrow. The inner ridge oF the masticatory surface is broad and
rough behind and divided by a deep longitudinal groove. The palate is deeply excavated. On
each pterygoid there is a hookt ectopterygoid process. The distance across the two pterygoids
is 30 mm.

The lower jaw (figs. 568, 569) is large and heavy. Its length from the symphysis to the
angle is 98 mm.; its height at the connor process, 32 mm.; at the symphysis, 21 mm. Each
ramus has its masticatory surface divided longitudinally by a deep groove. From the outer
cutting-edge sharp ridges run down on the outer face of the dentary.

The total length of the shell is 922 mm.; the width, 725 mm. The height can not be
exactly Be enned: on account of injuries to the carapace (plate 76). The middle region of
this has been Broken in, and the fragments considerably disturbed, while the unbroken portions
of the costals and to some extent, the peripherals, have been somewhat deprest. It appears,

Fics. 568 aND 569.—Testudo impensa. Skull and lower jaw of type. 3.

568. Skull, right side. 569. Lower jaw, seen from above.

however, improbable that the shell ever had as great height as that of 7. osborniana. The
width of the carapace is 78 per cent. of the length; whereas, in T. osborniana the width is 71
per cent. The peripherals have practically the same form as in the last-mentioned species,
but those of the bridge regions do not appear to have had relatively as great height. Neither
do the peripherals of the posterior region descend so steeply as in 7. osborniana. In the latter
the Py gal and the adjoining peripherals slope forward from the perpendicular only about 15°

or 20°; whereas, in 7. impensa the forward slope is about 45°. A part of this angle is due
possibly to depression, but this seems improbable. The anterior outline of the carapace 1s
convex, not straight or concave as in T. osborniana; and the anterior border does not pass so
abruptly into the lateral border.

On account of the crushing in of the upper part of the carapace, it has been difhcult to
determine the dimensions of the neurals, but the following statements may be relied on. The
first neural (fig. 570) is oval in form, and the width has been close to 70 mm. The second is
octagonal, and had a width, where greatest, of 120 mm. The third is hexagonal, 73 mm.
long and 97 mm. wide. The fourth is octagonal, 76 mm. long, 112 mm. wide. The sixth 1s
hexagonal, 70 mm. long and 100 mm. wide. The seventh is 63 mm. long and 118 mm. wide.

ashe third and the an costals are expanded at their proximal ends and each is 1n con-
tact with three neurals.

The pygal is 145 mm. wide at its upper end, 114 mm. at the free border. The first supra-
pygal has the usual bifurcate form and is in extensive contact with the pygal and the eleventh
peripherals. The second suprapygal is 90 mm. long and 84 mm. wide.

The plastron (plate 77; text-fig. 571) has a total ‘length of 805 mm. The width, from the
outer border of the hy oplastron oi one side to that of the other, is650 mm. There is a con-
siderable concavity in the region between the inguinal notches. The width of the anterio1

28

434 FOSSIL TURTLES OF NORTH AMERICA.

lobe is 470 mm., its length 230 mm. ‘The anterior lip projects well beyond the crossing of the
gular sulci. It does not pass_beyond the carapace; whereas, in 7. osborniana the lip projects
beyond the carapace about 80 mm. The lip is 185 mm. wide at its base and nearly as wide in
front. It is nearly flat below, convex above, and thickens backward on the upper surface to a
thickness of 60 mm. The posterior face of this thickened portion is somewhat excavated.
The whole free border of the anterior lobe is acute.

The posterior lobe has a width of 475 mm. and a length of 200 mm. The notch is broad
and shallow, its width being 165 mm., its depth only 30 mm. At the inguinal notch the border
of the hinder lobe presents a wall 85 mm. high, with a perpendicular outer face and a sloping
inner one. The wall diminishes rapidly in height backward, so that the thickness of the apices

570. 571.

FiGs. 570 AND 571.—Testudo impensa. Carapace and plastron of type. $.

570. Carapace. 571. Plastron.
of the xiphiplastra is only 34 mm. The structure of this region 1s greatly like that of 7. osborn-
iana. ‘The entoplastron is rhombic, 175 mm. on the midline, 230 mm. in transverse extent.
The suture between the two hyoplastra is 160 mm. long; that between the hypoplastra, 175
mm.; that between the xiphiplastra, 145 mm.

The first vertebral scute is 250 mm. wide in front. The second is 180 mm. wide; the
third is 137 mm. long and 200 mm. wide; the fourth, 166 mm. wide; the fifth, 210 mm. long
and 300 mm. wide. The gular scutes lap over on the entoplastron. The humeral scutes join
along the midline for 175 mm. ‘The pectoral scutes are very narrow at the midline, only
about 15 mm., but their outer ends expand greatly. The abdominal scutes occupy 275 mm.
of the midline; the femorals, 75 mm.; the anals, 96 mm.

The scapula is a large and stout bone. Its upper end, for union with the first costal,
extended above the glenoid cavity a distance of 162 mm. Near this upper end the bone is 38

TESTUDINIDZ. 435

mm. thick. At the middle of the glenoid cavity the bone is 54 mm. wide and 40 mm. thick.
The procoracoid process extended beyond the middle of the glenoid cavity a distance of 133
mm. The coracoid is short and broad. Each of the borders was about 130 mm. long, measur-
ing the anterior and the posterior from the glenoid cavity.

The humerus has a total length of 250 mm.; the head, a diameter of 58 mm.; the shaft,
where narrowest, a diameter of 42 mm. The distance across the condyles is 89 mm. The
angle between the radial and
ulnar processes is about as in
Gopherus poly phemus. The
trochlear surface is not grooved.
There is an_ ectepicondylar
groove, but it does not end in
a foramen.

The lateral extent of the pel-
vis, from the lower end of one
ilium to that of the other, is 276
mm. The total height is 220
mm. The upper ends of the
ilia are damaged. The ischia
have the posterior processes
rather slender and directed out-
ward and backward. The lat-
eral process of each pubis 1s
short, broad, and rounded on

Fic. 572.—Testudo impensa. Pelvis of type, <3. From below. the lower end. The ischiopubic

foramen is nearly circular.

Differences among the limb-bones, shoulder and pelvic girdles of this species and of vie
osborniana are noted in the description of the latter species.

The few cervical vertebra present offer no novel characters. The caudals have lateral
processes which are about 35 mm. long and directed outward and backward. It appears
probable that the end of the tail was expanded and supported a shield of dermal bones, as in
T. orthopygia and T. osborniana.

The dermal bones present are of various sizes and forms. The most of them have a base
which is roughened and has evidently been buried in the skin. The opposite surface is usually
smooth and forms a very deprest cone, the apex of which overhangs the base. This smooth
surface was doubtless covered with horn. These bones were probably concealed in the skin
of the legs. They vary in diameter from 20 mm. to 25 mm. Two larger, more pointed bones,
measuring from base to apex 35 mm. to 40 mm. and having a base of 25 mm. or more diameter,
probably formed the cores of spurs on the hinder parts of the thighs. Other bones, flat and
broad, with some of the sides straight or nearly so, are suturally united; and these in all
probability formed parts of a caudal shield, as in the species referred to above in speaking of
the caudal vertebre.

Testudo undata Cope.
Fig. 573.
Testudo undata, Corr, Ann. Rept. Chief Engineers, 1875, p. 995 (of separata p. 74); Wheeler’s Rept.
on Surv. W. rooth Merid., rv, 1877, p- 283, plate Ixvii, figs. 1, 2—Hay, Amer. Geologist, xx1Vv,
1899, p. 349; Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452.

Testudo undata was found in the Loup Fork deposits of the Miocene, in New Mexico,
by Professor Cope, in 1874. The species is based on the pygal and 7 hinder peripherals, all
somewhat damaged. These specimens are in the U. S. National Museum, with the numbet
2127. It is believed to be best to reproduce here Cope’s description and the most instructive
part of his figure 1, of the plate cited (fg. 573).

The specimen which furnishes the characters of the Testudo undata includes portions or wholes of
8 marginal bones and 1 costal. The former display a strong recurvature outward, and their internal
thickening is near their sutural union with the costals. The borders are acute and do not display any

430 FOSSIL TURTLES OF NORTH AMERICA.

emargination at either the dermal or osseous sutures. The posterior part of the margin of the poste-
rior marginals is very conyex or flared upward, descending at or behind the osseous suture. Thus the
free edge has an undulating
form. The caudal marginal
bone is recurved, not prom-
inent, and with a regular
entire free margin. Its lat-
eral sutures expand forward,
so that its margin Is narrower
than its anterior portion. It
is not divided by a dermal
suture, consistently with its
generic character. The sur-
faces of the bones are nearly
smooth. The scutal sutures are wide, and have distinctly-defined borders. The marginal near the bridge
is remarkably massive, the bridgeward suture being twice as thick as that } joining the free marginal.

The size of the Testudo undata is as great as that of any of the species of land-tortoises of our

Fic. 573.—Testudo undata. Pygal and hinder peripherals of the type.
+. Above the pygal is a section of the tenth peripheral.

‘Tertiary formations.
MEASUREMENTS.

Meter.
Length of the free margin of three consecutive posterior marginal bones 0.310
Length of the last marginal bone : 3 122
Width of the last marginal bone 135
Thickness at the middle... . O17
Thickness of the bridgeward suture of a lateral m arginal L040
Thickness of the opposite suture of the same. . ; ; » 015

Fragments of other specimens, probably of this species, present still larger proportions.

As compared with the two described species of Stylemys, this species differs in the strong flaring
and recurvature of its marginal bone, and is the more wedge- shaped caudal marginal bone, as well
as its much larger size.

To Cope’s description may be added the following: The thickness of the anterior sutural
border of the eighth peripheral, where it joined the een is 38 mm. The border which
joined the eae peripheral is 22 mm. thick. The eleventh peripheral is 122 mm. along the
free border; and was about 70 mm. along the upper border. Its greatest thickness 1s 23 mm.
The intermarginal sulci descend on low broad elevations of the surface and these elevations
are more pronounct as the free border of the peripheral is approacht.

Testudo klettiana Cope.
Fig. 574.

Testudo klettiana, Cope, Ann. Rept. Chief Engineers, 1874 (875), p- 995 (of separata, p. 75); Wheeler’s
Rept. on Sury. W. rooth Merid., rv, 1877, p. 285, plate Ixvii, fig. 3—Hay, Bibliog. and Cat. Foss.
Vert. N. A., 1902, p. 451.

This species was described from a specimen found by Professor Cope in the Loup Fork
Miocene of New Mexico. The type consisted of a pygal bone (fg. 574). This is now in the
U.S. National Museum at Washington. Its catalog number

is 2126. Cope’s description is as follows:

Indicated especially by a caudal bone of a tortoise of larger
size than the one regarded as typical of the T. undata. It is, of
course, probable that some of the fragments above described with-
out especial reference belong to it. The caudal bone differs from
that of 7. undata in being nearly plane, and thus wanting the recur-
yature or superior concavity of the corresponding bone of that
species. Its form is also quite different. Its lateral sutures are
nearly parallel, instead of divergent anteriorly, and slightly concave;
if a little expanded proximally, it contracts again to the suture for
the pygal bone. The suture is a short squamosal on the outside of
the caudal. The thickness of the bone is almost uniform to near
the proximal suture; there an abrupt rabbet commences the plane
of the thinner pygal.

Fic. 574.—T estudo klettiana. Pygal
forming the type. X 3

TESTUDINID. 437

MEASUREMENTS.

Meter.
Width, proximal notes 0.105
Width, distal. . 110
Length ..... . ; -110
Thickness. ... : 109

The free margin is slightly convex.

To this description it may be added that the thickness of most parts of the bone is 20 mm.
The free border is acute; most so near the midline.

There is no satisfactory evidence that the bones which furnisht Cope’s figs. 4 and 5, of the
plate cited in the synonymy, belonged to this species.

The form of the pygal, the lateral borders of which are parallel, appears to distinguish this

the Py8: nae y ; | PP iS
species from all others of our fossil species of T estudo.

Testudo niobrarensis Leidy.
Figs. 575-578.

Testudo (Stylemys) ntobrarensis, Letpy, Proc. Acad. Nat. Sct. Phila. 1858, p. 29; Extinct Mamm.
Fauna Dak. and Neb., in Jour. Phila. Acad. Nat. Sci. Phila. (2), vit, 1869, p. 26.

T estudo (Stylemys) niobrarensts, HAYDEN, Proc. Acad. Nat. Sci. Phila., 1858, p- 158.

Stylemys niobrarensis, Cope, Ext. Batrach., Reptilia, Aves N. A., 1869, p. 124.—Letpy, 2d (4th) Ann.
Rept. U. S. Geol. Surv. Wyoming, 1871, p. 366; Contrib. Extinct Vert. Fauna West. Terrs., 1873,
p. 225, plate iii, figs. 4-6.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 450.

Testudo ntobrarensis, Lery, Contrib. Extinct Fauna West. Terrs., 1873, p. 340, plate xix, figs. 6, 8.

This species was based on fragmentary bones which were collected by Dr. F. V. Hayden,
in the year 1857, in what were regarded as Pliocene sands along the Niobrara River. These

Fics. 575~578.—Testudo mobrarensis. Plastron, pygal, and suprapygal. U.S. N. M.

577. Suprapygal and pygal. X 4. Seen from above.
578. Section of pygal and suprapygal. 3%.

575. Upper surface of plastron.
576. Lower surface of plastron. >

Geno eona

deposits are now regarded as belonging to the Loup Fork Miocene. No exact statement
regarding the locality 1s given, but it was in all probability within the state of Nebraska. The
specimens are in the U. S. National Museum, at Washington. ;

The materials described and figured by Leidy consisted of the anterior portion of the
plastron, the posterior suprapygal and the pygal, the hinder median portion of the carapace,
the distal part of one humerus, and the distal part of one femur. These did not all belong to
one individual. The figures of the plastron, the pygal, and suprapygal, being parts most
characteristic, are here reproduced. It seems best, considering the possibility that more than
a single species is here included, to take as the type of the species the figured epiplastral lip.
This is No. 956 of the U. S. National Museum. Leidy’s figure of the pygal and suprapygal is
two-thirds the size of the original bones, altho he states in the explanation of the plate that it 1s
the size of nature.

438 FOSSIL TURTLES OF NORTH AMERICA.

In some of his earlier references to this species Leidy was in doubt regarding its distinctness
from Style mys nebrascensis, but-in his latest description he pointed out one character which
definitely separates it from the White River species. This is found in the lip, which projects
well beyond the general contour of the plastron and has a deep excavation beneath its backward
extension on he. upper surface of the lobe.

The plastral lip (Ags. 575, 576) 1s 36 mm. wide, measured from where one gulo-humeral
sulcus crosses the free boric to the crossing of the other. From a line on the upper side join-
ing these points the rounded, slightly orehe lip extends forward 13 mm. and backward g mm.
le hinder border overhangs thet excayation. The gulo-humeral sulci on this upper surface are
18 mm. long, that is, about one-third of the width Ba the base of the lip. The present thickness
of the lip is 18 mm. It appears to have been somewhat convex from side to side above.

From the original of Leidy’s fig. 6, plate 1 il, we learn that the fourth vertebral scute was
155 mm. long aoe 148 mm. wide, and that it occupied a portion of the eighth neural.

The pyg al (fig. 577) widens from the free to the superior border. ‘Above, it is somewhat
excavated for fhe reception of the suprapygal. As shown by fig. 578, which represents the
perpendicular section thru the pygal and the suprapygal, the pygal was slightly flared outward.
The free border is obtuse. The greatest thickness is 13 mm.

The part of the carapace figured by Leidy (No. 93, U. S. N. M.) must have belonged to an
individual about 610 mm. long. The part ‘included the sixth, seventh, and eighth neurals,
parts of the corresponding costal plates, and the upper end of the bifurcated suprapygal. The
fourth vertebral scute had a length of 155 mm. The upper ends of the costals are 15 mm.
thick. The limb bones figured by Leidy offer no novel characters.

This species appears to be distinguisht from both 7. vaga and the younger specimens of
T. osborniana by the more prominent plastral lip and the shortness of the gulo-humeral sulcus
on the upper side of each epiplastron. The pygal appears to differ from that of T. oshorniana
in being obtuse on the free edge. It appears likewise to belong to a more recent formation than
either oF the species just named: From T. farri of the Deep. River formation it differs in the
more projecting epiplastral lip and more elongated entoplastron.

Testudo orthopygia (Cope).
Plate 19, figs. 6, 7; plates 72-75; 78-80, fig. 1; text-figs. 579-606.

Xerobates orthopygius, Cope, Bull. U. S. Geol. and Geog. Surv. Terrs., 1v, 1878, p. 393-

Testudo orthopygia, Hay, Ainee Geologist, xxtv, 1899, p. 349; Bibliog. and Cat. Foss. Vert. N. A.,
1902, p- 451.

Xerobates cyclopygius, Cope, Bull. U. S. Geol. and Geog. Surv. Terrs., tv, 1878, 394.

Testudo cyclopygia, Hay, Amer. Geologist, xx1v, 1899, p. 349; Bibliog. and Cat. Foss. Vert. N. A., 1902,
ee os

Caryoderma snovianum, Cope, Amer. Naturalist, xx, 1886, p. 1044; Amer. Naturalist, xx1I1, 1889,
p. 662, plate xxxil, figs. I-17.

Testudo undata?, WILLISTON, Science (2), vin, 1898, p. 1

Testudo snoviana, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451-

In the year 1877 a party consisting of Messrs. C. H. Sternberg, R.S. Hill, and W. J. Brous
collected from the Loup Fork beds of Decatur County, Kone a considerable number of
specimens of turtles belonging to the genus Testudo. Out of these materials Professor Cope
described 2 species, giving them the names referred to him in the synonymy above. These
specimens are now in the Arcenean Museum of Natural History and have been studied by the
present writer, with the result that they are all assigned to one species, which must bear the
name orthopygia. According to Cope’s description, there existed between his two species a
great difference, one having - the hinder border of the carapace broadly rounded, the other
having it nearly straight and with rounded angles behind the inguinal notches. This striking
difference, however, disappeared when it was discovered that Cope had mistaken the anterior
border of the carapace of the type of his orthopygia for the posterior. This being the case, it
would be more appropriate to call the species cyclopygra, but the other name having preceded
the latter in the description, we must, according to rules adopted, retain the name orthopygza.

The type of the species 7. orthopygia bears the museum’s number 3929. It consists of the
skull and lower j jaw; the plastron quite complete; nearly the whole of the anterior free border

TESTUDINID#. 439

of the carapace; peripherals 7, 8, 10, and 11 of the right side; peripheral 11 of the left side;
the pygal; fragments of the costals and neurals; the right humerus; the left radius; the left
fibula; and the left half of the pelvis. Cope states that the limbs were present, but no other
parts of these now remain than those just mentioned. The plastron indicates by its flatness
that the individual was a female.

The skull (figs. 579-582) is nearly complete and has been described by Cope. A com-
parison of the table of measurements here given with those presented by that author shows that
some of the latter are incorrect. Cope’s figures, when differing, are given in parentheses.

Millimeters.
Length of skull from snout to end of supraoccipital spine 115
Length of skull from snout to end of occipital condyle 99
Width of skull at quadrates.. . sate 72 (80)
Width of interorbital space . 28 (19)
Greatest width of palatal fossa.......... ar 32536)
Elevation of occiput above basisphenoid . 33
Length of mandible from articular to symphysis aS
Depth of mandible at symphysis i 18 (19)

The skull is neither elongated nor broad. Seen from above (fig. 57g), the outlines expand
from the squamosal processes forward to the front of the quadrates. From the hinder ends

580.

Fics. 579 AND 580.—Testudo orthopygra. Skull of type. X 3.

579. Upper surface. 580. Palatal surface.

of the maxillz the outlines converge rapidly to the snout. The interorbital space is rather
wide and flat. The antero-posterior width across the paroccipital and prootic is 20 mm., while
that from the prootic to the hinder border of the postfrontal is 25 mm. Both squamosals are
missing. On the right side, as shown in fig. 581, the absence of the squamosal has exposed an
opening into the tympanic cavity of the quadrate. On the left side a considerable portion of
the hinder region of the quadrate has been broken away. The roof of the tympanic cavity
does not rise much above the upper surface of the paroccipital, and no prominent ridge ran
backward on the squamosal.

The jugal arches are damaged, but they appear to have been narrow; there is evidence
that they were at least 1: mm. wide. The orbits are nearly circular, and the antero-posterior
diameter is 27mm. The nasal opening has a transverse width of 21 mm. There is a median
notch at the symphysis of the premaxille. The cutting-border of the maxilla (hg. 581) 1s
nearly straight, but the hinder end is missing. The palatal fossa (fig. 580) is wide and deepl)
excavated. Cope states that the width is 36 mm. This seems to be too great, but the limits

440 FOSSIL TURTLES OF NORTH AMERICA.

are somewhat indefinite. There is no longitudinal ridge along the premaxillary symphysis;
hence the species is not a Gopherus, as defined by Agassiz under the name Xerobates. The
outer masticatory ridge is somewhat tootht; the inner ridge is rugose, especially posteriorly.
The latter nearly meet on the hinder borders of the premaxilla. The distance across the
pterygoids, where narrowest, is 18 mm. ‘There are distinct ectopterygoid processes. The
outward border of each pterygoid is continued backward and outward as a sharp ridge to the
hinder part of the base of the quadrate. From the fore part of this base another sharp ridge
runs upward and inward mostly on the quadrate. Between the two ridges is found a rather
deep groove.

The lower jaw (fig. 582) is complete. The depth varies from 22 mm, at the coronoid
process to 18 mm. at the symphysis. The masticatory surface is traverst lengthwise by a deep
groove; this does not join that of the opposite side at the symphysis. The external masti-
catory ridge is sharp and furnisht with small tooth-like processes. From these processes sharp
ridges run down on the outside of the jaw. The internal masticatory ridge rises higher than
the Feaeuiale It is rough and dentated. Anteriorly these inner ridges are directed forward one
on each side of the symphysis and terminate in a blunt tooth Pe the outer ridges meet the

symphysis.

Fics. 581 AND 582.—Testudo orthopygta. Skull of type, with lower jaw. 3.
581. Side view. 582. Lower jaw, upper view. art, articular; den, dentary; sur, surangular.
Several of the dimensions of the plastron of this animal, as given by Cope, differ from those

obtained by the present writer. In the following table Cope’s measurements are given in
parentheses, when differing from the author’s:

Millimeters. Millimeters.
Length of plastron in midline 515 (615) Width of base of anterior lip 132 (125
Width of plastron at axilla 330 (360) Width at end of anterior lip 70°
Width at inguinal border. . 290 (310) Length of anterior lip above... 105 (100)
Distance between posterior apices 100

Some of these discrepancies may be due to misprints, some perhaps to different methods
of taking measurements; but others appear to be obvious errors of determination.

The plastron (plate 78, fig. 1; text-fg. 583) is somewhat upturned at the front; also
moderately concave in the middle. Its length, given as 515 mm., is on a straight line from the
tip of the anterior lip to the bottom of ee posterior notch. The apices of Te posterior lobe
extend about 24 mm. further backward. The width of the plastron across the middle was
close to 450 mm. The greater portion of the free borders of the plastron is much thickened.
The figures indicate the form of the anterior lip. The width, 132 mm., is that taken between
the points where the sulci forming the outer boundaries of the gular scutes cross the free
border. Superiorly the lip runs backward some distance beyond ‘this. Fig. 584 is a section
at what is here termed the base; and fg. 585, a‘section 25 mm. behind the end of the lip.
Fig. 586 is a longitudinal section of the lip in the midline. It shows to what extent the lip
is excavated posteriorly.

The borders of the anterior lobe from the front to the axilla are acute. From the border
the bone thickens for nearly 50 mm., then thins toward the median portion of the plastron.

TESTUDINID. 441
At the junction between the epiplastron and the hyoplastron the greatest thickness is 30 mm.
The ascending portion of the hyoplastron at the axilla has a considerable groove behind its
free border and on the inner surface. Most of the hinder border of the entoplastron is at present
missing, but it was evidently broad and rounded behind and pointed in front. The length in
the midline was close to 110 mm. The greatest width is 160 mm. ‘The extent of the hyo-
plastron in the midline is close to 115 mm. The hypoplastra occupy 130 mm. of the midline;

the xiphiplastra, g7 mm.
584. 588.
aioe: wee i )
? - a ™ ; an aN, i}
y p © >} ia Meee
7 — ; See _, ; mos i
ie “ .
rh } 5 f
\ (
;

t
‘4
i

i
\
t
i
i
SRAM RP PRAY PLL MOG

583. 590a.
Fics. 583-590.—T estudo orthopygta.

Plan of plastron, taken mostly from type. Slightly less than one-fifth the original.

584. Section across the base of the epiplastral lip. Xt.
585. Section across epiplastral lip, 25 mm. behind tip. X}.

586. Longitudinal section of epiplastral lip. 4.
587. Section of border of left hypoplastron, just behind inguinal notch.

588. Pygal and left eleventh peripheral of type. 3.
589. Section of eleventh peripheral near union with tenth. 4.

590. Pelvis of type. il, ilium; isch, ischium; pub, pubis.

The hinder lobe of the plastron (fig. 583) is short, and is provided with a notch behind,
which has a width of 100 mm. and a depth of 24 mm. The lobe is flat below, concave above.
At the inguinal notch (fig. 587) there is a wall 67 mm. high, with a perpendicular outer face,
a rounded summit 16 mm. thick, and a steeply sloping inner face. Backward, the height of
the wall rapidly diminishes, and the outer face soon changes to a slope less and less steep.
At the apices of the lobe the height of the wall, above the lower surface of the bone, is only 30
mm. Its width here is 45 mm. The middle portions of the lobe are about 12 mm. thick. The

free borders of the lobe in the notch are acute.

583.

a, lower surface; , left side. 4.

442 FOSSIL TURTLES OF NORTH AMERICA.

The sulci of the plastron (fg. 583) are deeply imprest. The gulars extend backward on
the Ente plastica The humerals occupy 85 mm. of the median line; the pectorals only about
18 mm.; the abdominals, 200 mm.; the femorals, 68 mm.; the anals, 68 mm.

As already stated, Professor Cope described the anterior portion of the carapace as the
posterior. The evidence that the portion here regarded as the anterior is such 1s found in the
fact that the buttress which ascends from the plastron i is on the third peripheral from the
median element; whereas, the buttress at the inguinal notch ascends on the fifth peripheral
from the hinder median element, the pygal. That Cope had this anterior rim in view 1s shown
by the fact that it corresponds exactly with his description, while the portion of the posterior
rim present does not so correspond. All that Cope had to say about any part of the anterior
peripherals was a statement of the dimensions of one of them, and these figures apply quite
well to the eleventh peripheral.

The carapace was 470 mm. wide, probably rather high and vaulted, abruptly curved in
front of the axillary notches, somewhat concave in front, and broadly rounded behind.

The abrupt curves in the front of the shell occur on the second peripherals. The nuchal
and the anterior peripherals come to an acute edge. Backward from this edge the bones
thicken rapidly, become concave above, especially the second peripherals, and quite convex
below. The nuchal bone occupied 105 mm. of the free border and its greatest thickness is
30 mm. At the midline, the border of the carapace apparently lackt 55 mm. of extending as
ae forward as the tip of the plastron.

sgl. 592
a i a
oS ‘ pr
3 a
/ i \
\ f
Ls \
/ 4 ‘
\ :
i
J 3 - :
/ ea SOO
f ey, e ‘
a : 593
e
aes, Qe

Fics. 591-5§93.—Testudo orthopygia. Epiplastral lip. 4}. No. 1325 A. M. N. H.
sgi- Upper surface. 592. Section at ends of gulo-humeral sulci. 593- Longitudinal section.

The hinder peripherals flare upward somewhat as the free border is approacht. The
eleventh (fig. 588) occupies 80 mm. of the free border, is 34 mm. thick and 107 mm. high.
The pygal (figs. 588, 589) is 75 mm. wide at the free border and about 75 mm. high.

Only unimportant fragments of the neurals and costals of the type specimen remain.
There was the same alternation of larger and smaller neurals that we see in the living species
of the genus. Likewise, the proximal ends of the costals were alternately narrow and wide.
Two cule. which are regarded as the third and fourth of the left side, are represented by
their proximal ends. ‘The: third is 75 mm. wide where it has joined the neurals, while the
fourth is only 44 mm. wide. The bone is 8 mm. thick.

There is present with the type a humerus which lacks the distal end. There is no femur
present, altho Cope mentions one. He states that its length, estimating for the absent condyles,
is 170 mm. and the width of the head plus the great trochanter go mm. A perfect femur of a
still larger specimen, next to be described, has a ength of only 150 mm. The humerus referred
to, allowing for the missing distal end, had a length of about 170 mm. and a thickness thru
the head and the ulnar tuberosity, of 85 mm. It seems evident, therefore, that Professor Cope
inadvertently spoke of the humerus as the femur. As the complete humerus of another
specimen will be described, that of the type will be passed by.

TESTUDINIDA. 443

The pelvis (figs. 590 a, ) is represented by the greater portion of the left side. The lateral
process of the pubis is rather short, flat, and broad and rounded at the end. The tuber ischii
is rather slender and pointed.

No. 1325 of the American Museum is likewise a part of the Cope collection. It was a
larger animal than the type just described. The length of the plastron is 615 mm. and its
width to the outer borders of the bridge peripherals could not have been less than 555 mm.
The width of the carapace at the inguinal notches was 600 mm. Almost the whole of the
plastron is present; also considerable parts of the costals and neurals in a fragmentary state;
and the greater part of the rim of the carapace, of the shoulder-girdle, of the pelvis, and of the
limbs. ‘The plastron differs from that of the type principally in the size and form of the
anterior lip. This (fig. 591) is relatively broader, with its sides less converging, less truncate
in front, and less cari-
nated above. Since, how-
ever, the two individuals
are so closely alike in all
other respects and there
seems to be a good deal
of variation in the form
of the lip among the var-
ious specimens, there is
apparently no_ sufhcient
reason for regarding No.
1325 as belonging to a
different species. The
width of the lipat the base
is 184 mm. Where the
curve of the sides into the
anterior border 1s made
the width is 150 mm.
Instead of being slightly
notcht in front, the ante-
rior border is broadly
rounded. From side to
side the upper surface is
evenly convex. Figs. 592,
593 represent sections of
the lip.

The entoplastron is 163
mm. long and 200 mm.
Fics. 594 AND 595.—Testudo orthopygia. Left humerus. 3. wide. The humero-pec-

No. 1325 A. M. N. H. toral sulcus passes just
behind its hinder border.
The plastron is rather
deeply concave in front of the hinder lobe, a condition which indicates that the individual
was a male. Fig. 2 of plate 78 gives a view of the rear of the shell seen from below.

Of the anterior portion of che carapace only peripherals 1, 2, and 3 are present. They
differ in no important respect from the corresponding elements of the type. Almost the w hole
of the posterior rim is present, the pygal and most of the peripherals being complete. At the
midline the hinder edge of the carapace falls about 120 mm. behind the plastron. The upper
portion of the peripherals i is nearly perpendicular, but the lower portion is considerably flared
outward. The eighth peripheral has a height of 160 mm.; the eleventh, of 120 mm. The
second suprapygal i is present, of rhombic fatten, and about 110 mm. from side to side. Its
lower half is placed in a notch in the pygal. The sulcus behind the fifth vertebral scute crosses
it horizontally in the middle. Costals and neurals too fragmentary to justify description.

The left scapula is present in No. 1325. The length of the bone from the superior extremity
to the middle of the glenoid fossa is 180 mm.; from the latter point to the extre mity of the

594. Radial border. 595. Dorsal surface.

444 FOSSIL TURTLES OF NORTH AMERICA.

procoracoid process is 125 mm. ‘The two branches of the bone make an angle of about 120°
with each other. The bone is a stout one, the width across it at the glenoid fossa being 50 mm.

The left humerus (figs. 594, 595) is complete, with the exception of a missing part of the
ulnar process. It is a stout bone, but not so much curved as in some species of the genus, even
less so than in Gopherus polyphemus. The total length is 200 mm.; the diameter thru the
head and ulnar process is 100 mm.; thru the external and internal condyles, 76 mm.; and thru
the narrowest portion of the shaft, 35 mm. The planes of the ulnar and radial uiberosiies
make a small angle between them, about the same as in G. polyphemus. The trochlear surface
is well defined. W hen the bone is in its natural position, this surface is directed strongly down-
ward. It is trayerst from the dorsal to the ventral surface by a broad and rather deep groove.

The left radius and ulna are represented in fig. 596, but more or less hidden by portions
of the dermal armor. They are stout bones, the ulna having a length of 110 mm., a breadth
across the middle of the shaft of 29 mm., across the distal end oe 43 mm. The ‘radius has
a total length of 112 mm. The head is expanded. The slender portion of the shaft has a
diameter of 16 mm.

The bones of the digits are all present, except the ungual phalanx of the first. Some of the
bones are slightly disturbed and their positions are somewhat obscured by the dermal bones;
but some notes are obtained regarding them. The radiale is a small bone which does not ex-
clude the first carpal from extensive connection with the radius. This radiale has a rhombic
superior surface, articulates by its proximal surface with the intermedium, and by its radial
surface with the radius. The intermedium is elongated in the direction of the axis of the limb,
articulates by its proximal end with the ulna and ‘by its radial surface with the upper portion
of the articulatory surface of the radius. The length of the intermedium is 24mm. The ulnare
is not suthciently enlarged to exclude the fifth carpal from contact with the ulna.

Carpale 1 is father larger than the radiale, and articulates extensively with the distal end
of the radius. The ungual phalanges vary in length from 34 mm. in the first to 38 mm. in the
last. They are flat or slightly convex both above and below, and their distal ends are blunt.

In the small size of the radiale and ulnare the bones of this carpus resemble most those
of Gopherus poly phemus, but in the latter carpale 2 also joins the radius.

Of the pelvis there are present portions of both sides. The ilium has a total length of
155mm. Its greatest diameter, at the upper border of the acetabulum, is 71 mm. The lateral
process of each pubic bone is broad and flat, and the distal end is rounded.

Both femora have been preserved. ‘They too are stout bones, little bent, and having the
distal articular surface directed strongly downward, when the bone is in its natural position.
That of the right side is shown in figs. 597, 598. The total length, measured parallel w ith the
axis of the bone, is 150mm. Thru “the head and the trochanter the distance is 77 mm.; thru
the tuberosities, 63 mm. The shortest diameter of the shaft is 24 mm. A ridge separates
the fibular condyle from that for the tibia. The latter has a broad groove running dorso-
ventrally.

The tibia (fig. 598) is also a relatively short and thick bone, the length being 99 mm., the
distance thru the tuberosities 46 mm.

Most of the bones of the left hind foot (fig. 599) are so completely hidden by the dermal
armor that, with the exception of the ungual phalanges and calcaneum, they can not be
studied. The calcaneum resembles that of other species of Testudo. The ungual phalanges,
4 1n number, resemble those of the forefoot.

Fig. 600 represents the terminal six vertebrae of the tail. The lateral processes are some-
what elongated, so that the end of the tail is paddle-shaped, instead of pointed. The last three
vertebra are consolidated into one mass. Two or three vertebra above those shown in fig. 601
have their lateral processes standing at right angles with the centra.

Professor Cope made the observation that this species possest numerous osseous bosses on
the limbs, doubtless ossifications of large marginal and other dermal scutes. These are said to
have a low apex, central or concentric. Further description was not furnisht. More complete
preparation of his specimens, especially No. 1325, shows that these bosses were found on the
fore limbs, the hind limbs, and on the tail and the region surrounding the latter. Fig. 595
shows a number of these osseous scutes on the upper surface of the distal end of the humerus.
They are rather small and closely joined. No doubt, they lay embedded in the skin that coy-

TESTUDINID. 445

ered this bone and each was covered with a horny scute. Fig. 596 represents the armor of
bony nodules which covered the outside, or dorsal surface, of the lower arm and foot. Here the
nodules are large. The one lying across the ulna 1s really formed of two, suturally joined. In
all of these, thick outer surface is flat or slightly convex; while the deeper surface is more strongly
convex, sometimes forming a low apex. On the forearm and foot the lower end of each scute
overlaps the next one below. The same specimen shows that the bottom of the foot was shod
with these bony scutes. Close to the toes they are small, but beneath the carpal bones and on
the ulna are some very large ones, flat externally, convex on the inner surface.

599. 600. 598).
Fics. 596-600.—T estudo orthopygia. Limb bones and tail. 4. No. 1325 A. M.N. H.
596. Ulna, radius and front, with dermal ossicles. 597. Femur, tibial border.
598. Right femur (a) and tibia (5), dorsal view. 599. Sole of hind foot. 609. Tail, lower surface.

Fig. 602 represents the left femur, seen from the ventral side. At the proximal end is seen
a patch of nodules which probably occupied the skin just outside of the lateral border of the
hinder lobe of the plastron. No specimen shows these nodules on the lower portion of the
femur, but we can hardly doubt that they covered also these portions of the limb. Fig. 599
shows the bottom of the hind foot. This is seen to have “been heavily armored with these
bony plates. Those near the ungual phalanges are smaller; those at the heel, quite large and
thin. Others quite small appear to have been found somewhat higher up on the foot.

440 FOSSIL TURTLES OF NORTH AMERICA.

In fig. 603 we have a view of the dermal armor that covers the end of the tail. This con-
sists principally of about 12 polygonal bones which are suturally joined. Around these are
arranged smaller bony scutes which are less closely joined, and which evidently permitted a
bending of the skin. The lower border of the fragment here figured rested on the upper sur-
face of the hinder border of the plastron, doubtless just in the position occupied during life.
On another fragment (fig. 604), belonging higher up on the tail, there are other ossicles and
a conical bony spur. This spur is 38 mm. long, 18 mm. in diameter at the base, and some-
what curved. The coat of mail found on and around the tail resembles that found in T.
osborniana. Its purpose was evidently to close up effectually the space between the feet when
these were withdrawn into the shell.

There can scarcely be a doubt that the dermal bones and the ungual phalanx described
as cited in the synonymy, by Professor Cope, under the name Caryoderma snovianum and
thought by him to belong to a glyptodont, belong in reality to this species. Entirely similar
bones are among the specimens of 7. orthopygia collected for this author and described by him
in 1878. Dr. S. W. Williston first made the observation that these supposed Edentate bones
were those of a turtle and referred them with doubt to Testudo undata. The types of Caryo-
derma snovianum are in the University of Kansas and were found in the Loup Fork deposits
of northern Kansas.

ool.

Fics. 601-603.—Testudo orthopygia. Femur and tail. 4. No. 1325 A. M. N. H.

601. Two caudal vertebra, lower side. , 602. Proximal end of femur, ventral surface, with dermal bones.
603. Tail, upper surface, covered with an armor of dermal ossicles.

In Cope’s description of his Xerobates cyclopygia three specimens appear to have been
studied. In his table of measurements these are designated as “‘ No. 1,” “No. 2,” and “No. 3.”
His “‘No. 1” is identified by the present writer as No. 1322 (plate 19, fig. 6) of the American
Museum of Natural History, since there is no other in the Cope collection that comes so near
answering the requirements. The length of the hinder lobe 1s said to be 140 mm., and the
width 240 mm.; but the latter is really 270 mm. With this specimen are many fragments of
the carapace. The anterior lobe of the plastron is missing. A portion of the entoplastron is
present, but not enough to determine its dimensions. The bottom of the plastron is quite flat,
there being only the slightest concavity in front of the hinder lobe. The form of the hinder lobe
is that of the type of 7. orthopygia. The notch in the hinder border has a width of 76 mm.
The hyoplastra occupied 112 mm. of the midline; the hypoplastra, 122 mm.; the xiphiplastra,
86 mm. The notch has a depth of 32 mm. The sutures separating the hyoplastra from the
xiphiplastra are extremely coarse. The sulcus which runs lengthwise thru the middle of the
plastron is very wide and deep. The humero-pectoral and the pectoro-abdominal sulci are like-
wise deep but narrow. The pectoral scutes are extremely narrow, not more than 4 mm. wide
at the midline but widening right and left. The abdominal scutes meet along the midline
190 mm.; the femoral scutes, 57 mm. The femoro-anal sulci are angulated about the middle
of their length. The areas occupied by the abdominal scutes are broadly grooved. These
grooves indicate the stages of growth of the scutes.

TESTUDINIDA. 447

Considerable portions of the carapace of this specimen are preserved; but they are in a
fragmentary condition. The costals are crost by conspicuous ridges and grooves.

Cope’s “No. 2,” No. 1323 of the American Museum, presents an imperfect carapace
(plate 19, fig. 7), most of the lateral and all of the hinder border being gone. Cope states that
the axial length was 330 mm.; but it is certain that it was in life considerably longer. Cope
describes the carapace as being flattened, but this appearance is undoubtedly due to the bad
state of the specimen. The front outline is truncate, with the nuchal and peripheral bones flared
considerably upward. The sutures between the various neurals and costals are not well shown.
The nuchal scute is said by Cope to be 4 mm. long, but this appears to be a misprint for 40 mm.
Its width anteriorly is 17 mm.; posteriorly, 24 mm. The second and third marginal scutes are
67 mm. wide fore and aft. The first vertebral scute is 110 mm. wide in front and 77 mm. wide
behind. The second and the third are 110 mm. wide across the middle, and this width 1s about
that of the costal scutes. On the hinder portion of the first vertebral scute area is a conspicuous
boss, from which a ridge continues forward some distance. On each of the other vertebral

606

Fics. 604-606.—T estudo orthopygia. Carapace and dermal ossicles. 3.

604. Patch of dermal armor near the tail, showing a bony spur.
605. Plan of carapace, constructed from various specimens in A. M. N. H. 606. Ilium.

areas there is a depression, horseshoe-shaped, with the opening forward. The costal bones are
grooved and ridged parallel with the borders of the carapace.

Cope’s “No. 3” is evidently the specimen now bearing the American Museum’s number
1324, and furnishes the hinder half of the carapace. It is a smaller specimen than the one
described above, the width of the carapace at the inguinal notches being only 250 mm. The
hinder border is rounded, most of the peripherals are somewhat flared upward at the border,
and the free edges are acute. The fifth vertebral scute is 33 mm. wide in front, 100 mm. behind
and 62 mm. long in the midline. All of the costal scute areas and that of the fifth vertebral
are sculptured with grooves and ridges which run parallel with the border cf the carapace.

After a study of all the iatereds at hand the writer has concluded that the specimens
called cyclopygia are merely the young and half-grown individuals of 7. orthopygia. The
grooving of the carapace may be observed on some of the costals of specimens that must be
referred to orthopygia. The width of the pectoral scutes varies in different examples and prob-
ably becomes relatively greater in the older individuals. The same remark may be made
regarding the notch in ‘the rear of the plastron. The anterior lip of the plastron is likewise
variable, but within what limits it is hard to say. The usual form in the larger individuals, some

448 FOSSIL TURTLES OF NORTH AMERICA.

of which would belong to cyclopygza, is that of the type of T. orthopygia. In one specimen of
“cyclopygia,” a young individual, there is a broad longitudinal groove running along the under
side of the lip, and another on he upper side. This specimen and others of similar size appear
to indicate that usually during growth the upper groove disappeared and this surface of the lip
became roof-shaped. The lip ‘of No. 1325, which has been described and figured, deviates
most from the typical form and under other circumstances might possibly be regarded as
belonging to a distinct species.

Fig. 605 is a diagram of the carapace made up from the various specimens in the Cope
collection, of fossil reptiles, now in the American Museum of Natural History.

Plate 79, figs. 1, 2 and plate 80, fig. 1, present views of this species seen from above, below,
and from the right side. The plastral view is taken almost wholly from No. 2415, A. M. N. H.,
except the tip of the anterior lip and the border of the carapace in front of the axillary notch.
These parts are furnisht by No. 3931, an individual of the same size. The other figures have
been taken mostly from No. 2415, but those parts in front of an irregular line extending from
the front of the third neural forward and outward to the free bores a little in front of the
axillary notch are taken from Nos. 3931 and 2320. The tip of the plastral lip is completed from
No. 3931. These figures reveal the great height of the peripheral bones.

607. 608.

Fics. 607 AND 608.—Testudo sp. indet. Pelvis and femur. X43. No. 2416 A. M. N.H.
607. Pelvis showing slender lateral pubic process. 608. Right fernur.

Judging from the numbers of this species in the Cope collection, it must have been very
abundant. Another and quite perfect specimen is in the museum of the University of Kansas.
Fig. 606 represents an ilium of No. 2426 of the American Museum of Natural History. It is
that of the right side.

Plates 81 and 82 are reproduced from photographs of a large specimen of this species
which belongs to the American Museum of Natural History. It hae the catalog number 6108.
This, with several other fine specimens, was collected in the year 1905, by Mr. Charles H.
Sternberg, in the typical locality, Decatur County, Kansas. The specimen figured has the
shell complete, with the exception of the third, fifth and sixth costal plates. The length from
the anterior end of the plastron to the hinder border of the carapace is 710 mm. The plastron
projects beyond the anterior border of the carapace 80 mm. The width of the carapace is 520
mm. The height is about 330 mm.

The plastron i is 622 mm. long. The epiplastral lip is nearly flat below, roof-shaped above.
The thickening on the upper surface continues backward 113 mm. Here the thickness is

TESTUDINID&. 449

about 75 mm. The limbs and the region about the tail present the armor that has been already
described. Another shell collected by Mr. Sternberg and now in the American Museum has
a total length of 800 mm.

Among the materials collected by Mr. C. H. Sternberg and his party, in 1877, in the Loup
Fork beds of Decatur County, Kansas, are some portions of a large tortoise which appears to
be specifically different from 7. orthopygia. The portions represented by determinable bones
are the greater portion of the shoulder-girdle, the right half of the pelvis, and the femur. The
number of the specimen is 2416 of the American Museum of Natural History.

The length of the coracoid, from the suture in the glenoid fossa to the inner hinder angle,
is 135 mm., the breadth of the inner border, 110 mm., and the breadth across the neck of the
bone 37 mm. The procoracoid process is a stout bone, without distinctive characters. Only
a portion of the scapula remains.

The width of the pelvis (fig. 607), from the pubic border of one acetabulum to that of the
other, was 226 mm.; the length along the midline, from the hinder border of the ischia to the
notch in the pubes, 135 mm. The least width of the ischium mesiad of the ischial tuberosity
is 43 mm.; laterad of the tuberosity, 28 mm. The least width of the pubis mesiad of the
lateral ee is 32 mm.; posterior to the lateral process, 38 mm. The symphysis of the
ischia is very thick, 22 mm.; that of the symphysis of the pubes, only 10 mm. The chief
feature which distinguishes the pelvis from that of TZ. orthopygia is found in the lateral process
of the pubis. In 7. orthopygia this is relatively short, but broad and comprest, with the upper
surface convex, the lower concave, the distal end broadly rounded, and the horizontal diameter
nearly twice the perpendicular. In the pelvis here described the process is nearly twice as
long as in T. orthopygia, tapering, convex above, with a prominent ridge below, and the
horizontal diameter less than the perpendicular.

The right femur (fig. 608) is nearly complete, the head only being somewhat damaged. It
isa Senet sleaderent element than the corresponding bone of 7. orthopygia. The table pre-

sents the measurements of this bone

Diameter. ' compared with those of the femur
Seen Length _ a ~ of T. orthopygia, No. 1325, American
of femur. | Thru Shaft Thru M N ar :
trochanters. ° 4 tuberosities. . WEST ge atura : Istory. i

= While the articular head of the

sete an Moe vith femur of the form here described is

Testudo orthopygia. 143. | 63 24.5 60 damaged so that its exact dimensions
Undetermined form. 155 53 21 64

can not be determined, it appears not
— : to have been so large as that of the
species with which it is here compared. On the other hand, the digital fossa is much larger
than in T. orthopygia, having nearly twice the diameter. It is to be observed that the diameter
thru the distal tuberosities of the present form is greater than in the specimen of T. orthopygza.
The type of the latter species has the distal end ‘of the femur 63 mm. wide.
It is, of course, possible that the materials here described belong to some already named
species of Testudo, but this can be determined only by future research

Testudo gilberti Hay.

Plate 80, figs. 2-5.

Xerobates? undata, GILBERT, Kansas Uniy. Quart., vil, ser. a, 1898, p. 143, figs. 1-4.
Testudo gilbertit, Hay, Amer. Geologist, xxiv, 1899, p. 349; Bibliog. and Cat. Foss. Vert. N. A.,
1902, p. 451.

The only part of this animal yet known is the skull, including the lower jaw. This was
found in the Loup Fork deposits of Phillips County, Kansas, and was described by Mr. J. Z.
Gilbert, who referred it with some doubt to Cope’s New Mexican species, Nerobates undata.
The latter was based wholly on portions of the carapace, and there is no evidence that the skull
belongs to the same species, except that the two occur in the same formation. The skull has
suffered some injuries. ‘The squamosal and a part of the quadrate on the left side are gone,
thus exposing the tympanic cavity. The pedicels of both quadrates are broken away, as well as
the occipital condyle.

29)

450 FOSSIL TURTLES OF NORTH AMERICA.

The skull (plate 80, hg. 2) is rather narrow. From the front of the tympanic cavity the
sides converge slowly to the orbits; then more rapidly to the rounded snout. The height from
the cutting- edge of the maxilla to the level of the frontals is contained in the length to the
occipital condyle 2.5 times. The following are some of the dimensions:

Millimeters. Millimeters.
Snout to occipital condyle : 93 Width of interorbital space Aacmiden nd
Snout to end of supraoccipital 110 Antero-posterior diameter of orbit 23
Width at base of quadrates 66 Width of palatine fossa. . 23
Width at hinder ends of maxilla 62

Seen from the side (plate $0, hg. 4) the upper outline of the skull is slightly concave at the
parietals and convex over the orbits. From the latter the profile curves gradually downward
to the tips of the pretrontals. The nasal opening is wider than high. The prefrontals meet
along the midline for 18 mm., nearly the length of the suture between the frontals. The orbits
are nearly circular. The jugal arch is narrow, being only 7 mm. wide. The maxillary has a
width of 12 mm. from the orbit to the cutting-edge. The latter, seen from the side, is concave
from the premaxillary to the hinder end. Any notches or denticles on the premaxillary were
small, if existent. The antero-posterior extent of the otic region, measured across the par-
occipital and the prootic, is only slightly more than the extent of the temporal opening in front
of the prootic. The supraoccipital extends behind the line joining the squamosal processes of
the skull a distance of 13 mm.

Seen from below (plate 80, fg. 3) the skull displays a highly vaulted palate. The vomer
is highly archt in the middle of i length, and is traverst aot its length by a median
ridge. The masticatory surface presents two prominent ridges separated by a groove. The
inner ridge is broad and rough behind. The outer is high and sharp, and One wiat tootht.
It is conmmued forward on the premaxilla, being separated from that of the other side by a
very distinct groove. “The distance across the pterygoids, where narrowest, is 18 mm. There
appear to have been no en ae processes.

The lower jaw (plate 80, fig. 5) is represented by the co-ossified dentaries. The height is
12 mm. in front, 13 mm. behind: Each dentary presents a masticatory surface having a width
of gmm. This is occupied by 2 ridges separated by a deep groove. The inner ridge i is rough
and furnisht anteriorly with small tooth-like processes. The outer ridge has been slightly
serrated, and from the serrations low ridges run downward on the outer surtace of the bone.
The inner and outer ridges meet both in front and behind, thus closing up the groove.

This species resembles closely the one described here as 7. ae beeebana. but it differs in
several respects. The jugal arch is narrower. The antero-posterior extent of the otic region is
about equal to the distance from the prootic to the upper end of the postorbital arch. The
squamosal processes are thin from side to side, and rise outwardly to a crest which stands over
the tympanic cavity at a level considerably higher than the surface of the paroccipital. The
whole skull seems to have been of a lighter construction than that of 7. osborniana. The skull
of T. orthopygiais relatively broader, has a considerably wider interorbital region, a squamosal
process less comprest laterally and with a less prominent crest above. The orbit is somewhat
larger and the snout longer.

Testudo ede Hay.
Plate 83, figs. 1, 2

Testudo ede, Hay, Ann. Carnegie Mus., tv, 1906 (1907), p. 19, plates vii, vill.

The single specimen which forms the type of the present species was collected by Mr. O.
A. Peterson, of the Carnegie Museum, in Loup Fork, or Nebraska, deposits, at Running
Water, Sioux County, Nebraska. The catalog number is 1535. The specimen consists of a
carapace and plastron from which is missing a portion of the right side. Altho there has
occurred some crushing together of the carapace and the plastron, it seems evident that even
in life the shell was not greatly elevated. The middle region is and was flat from side to side,
as far out as the outer borders of the vertebral scutes. Near the hinder border of the first
vertebral scute there is a low elongated median boss. At the sides and in front of this the
scute area is concave. The second and third vertebral scute areas are likewise slightly con-
cave. Furthermore, the areas of the first, second and third marginal scutes are decidedly
concave. The peripherals over the fore and hinder limbs flare upward somewhat. The lower

TESTUDINID&. 451

border of the pygal is drawn in, as in 7. arenivaga. The length of the carapace is 450 mm.;
the breadth was 380 mm.

The first and third neurals are four-sided; the second and fourth are octagonal; the fifth,
sixth, and seventh are hexagonal. There appear to be only 7 neurals, of which the table gives
the dimensions.

Dimensions of neurals. | Dimensions of costals. | Dimensions of vertebrals.
: iNet _ | Proximal! Distal |. | | width | Greatest
No. Length. Width. No. «idth. width. | No. Length. SGT Ee adhe
|

1 48 45 | 2 30 85 1 95 115 11S

2 43 vie 3 54 27 2 83 83 | 120
3 37 58 4 28 7O 3 93 100 130
4 56 2 5 48 31 4 75 go 105

5 40 65 6 32 63 5 93 55 140
6 36 60

7 40 40

The nuchal is 92 mm. long, with a maximum width of 105 mm. and a frontal width of
73mm. All the peripherals are acute on the free border, and each presents a projecting point
at the end of the intermarginal sulcus.

The costals are strongly differentiated as regards the widths of the opposite ends. The
table presents their widths.

Some measurements of the pygal and the eleventh peripheral are given under the descrip-
tion of J. arenivaga.

The sulci are all narrow and they run along on the summits of low ridges. The dimensions
of the vertebral scutes are shown above.

The plastron has a total length of 445 mm. It is concave especially in the hinder third, a
condition that indicates that the individual was a male. The anterior lobe is 155 mm. long and
205 mm. wide at the base. This width continues forward with hardly any diminution to a
point in front of the hyoepiplastral suture. The border then rounds rapidly to the base of the
epiplastral lip. The width of the latter, at the ends of the gulo-humeral sulci, isgo mm. The
lip extends forward from its base a distance of 55 mm., narrowing rather rapidly. The extrem-
ity is slightly damaged, so that its exact form can not be determined. The lower surface of the
lip curves upward strongly, like the runner of a sled. The upper surface is slightly convex
from side to side. The greatest thickness of the lip is about 25 mm. On the upper side the
thickening extends backward from the front of the lip a distance of 105 mm., thus including the
front end of the entoplastron.

The length of the entoplastron is 84 mm.; the width, 88 mm. The bridge is 185 mm. wide.

The hinder lobe is 112 mm. long and 235 mm. wide at the base. The posterior notch is
33 mm. deep and 70 mm. wide. At the inguinal notch the thickness of the hypoplastron is 30
mm. This becomes rapidly reduced farther backward.

The gulars overlap the entoplastron about 22 mm. The humerals occupy 80 mm. of the
midline; the pectorals, only 25 mm.; the abdominals, 120 mm.; the femorals, 60 mm.; the
anals, about 40 mm.

This species is named in honor of Mrs. Eda Peterson, wife of the discoverer of the type
specimen,

Testudo hollandi Hay.

Plate 84, figs. 1, 2.
Testudo hollandt, Hay, Ann. Carnegie Mus., tv, 1906 (1907), p. 18, plates v, vi.

The type of this species belongs to Carnegie Museum, Pittsburg, and has the catalog
number 1561. It was discovered in the upper beds of the Loup Fork, or Nebraska beds, near
Running Water, Sioux County, Nebraska, by Mr. O. A, Peterson. The shell alone is preserved
and this is somewhat crusht downward. The carapace is broad, truncated in front, rounded
behind, with the free borders a little flaring over the hind limbs and a little drawn in on each
side of the midline behind. The region along the middle of the back is rather fat, and pre-
sents no traces of a keel. From the free border of the carapace in front of the axillary notch

452 FOSSIL TURTLES OF NORTH AMERICA.

a sharp carina passes backward over the bridge to the free border behind the inguinal notch.
Possibly the acuteness of this has been accentuated by crushing.

The plastron projects considerably in front of the carapace. This does not appear to be
due to any crushing, for the hinder end of the plastron approaches closely the border of the
carapace.

The length of the carapace is 305 mm.; its width, 280 mm. All the free borders are acute.
The nuchal has a length of 57 mm., a maximum width of 67 mm., and a width of 43 mm. along
the free border. The first neural is oval, the second and fourth octagonal; the third, fifth, and
eighth are 4-sided; the sixth and the sev venth, hexagonal. The table shows their dimensions.

Dimensions of neurals. Dimensions of costals. Dimensions of vertebrals.
; Proximal Distal = Width Greatest
No. Length. Width. No. widths wide No. Length. Fe are Saree
1 38 31 2 21 65 1 65 65 65
z 35 5o 3 39 15 2 57 57 83
3 28 43 4 22 58 ct 60 73 92
4 35 55 5 28 37 4 63 7 83
5 28 41 6 20 33 5 57 3 100+
6 18 50 7 17 26 |
7 24 51
8 26 26

The etl places a are alternately wide and narrow at sheik eroanal ends and narrow and
wide at their distal ends. The widths are given in the table above.

The nuchal scute is 15 mm. long and 13 mm. wide. The dimensions of the vertebrals are
herewith shown in tabular form.

The plastron has a length of 325 mm., being thus longer than the carapace. The anterior
lobe is 100 mm. long and 148 mm. wide at the base. The epiplastral lip is 70 mm. wide at the
ends of the gulo- ee sulci and it projects beyond these a distance of 28 mm. The free
borders of the lobe, including the lip, are acute. The anterior border of the lip is notcht.
The thickening of the lip is ponenucd backward a distance of 45 mm. from the front; it then
drops off suddenly, forming an escarpment, which is somewhat excavated beneath. At the hyo-
epiplastral suture the width of the superior horn-covered surface is 27 mm. The entoplastron
is 61 mm. long and 58 mm. wide. The bridge has a width of 150 mm.

The hander lobe is 55 mm. long at the midline, 7o mm. total, and has a width of 155 mm.
at the base. Median ee 15 mm. deep and 55 mm. wide. Near the inguinal notch the free
border of the lobe is about 17 mm. thick; sore posteriorly it becomes thin and finally acute.

The gular scutes are 60 mm. long in the midline. The humerals occupy 54 mm. of the
midline; the pectorals, 24 mm.; the abdominals, g5 mm.; the femorals, 40 mm.; the anals,
33mm. The axillary and inguinal scutes are present, but small.

No. 1536 of the Carnegie Museum is a nearly complete shell, smaller than the preceding.
It is referred to this species. It presents the difference of having a smaller epiplastral lip.

No. 1570 of the Carnegie Museum is also referred to the present species. It was obtained
in 1902, by Mr. Earl Douglass, at Cold Spring, Montana, in what the discoverer regards as
Upper Loup Fork beds.

The hinder parts of both carapace and plastron are wanting. The epiplastral lip does not
project so much in front of the carapace as in the type, but this may be due to some distortion.
The entoplastron is 52 mm. long and 60 mm. wide, differing thus somewhat from that of the
type, whose entoplastron is longer than wide. Pectoral scutes 28 mm. wide at midline.

The surtaces of this shell and those of the type are sculptured by the growth lines of the
epidermal scutes.

This species differs from 7. farr: in having the first vertebral scute much less expanded, in
having the opposite ends of the costals more introwed and more widened, and the epiplastral
lip more strongly developt. It differs from T. vaga in having a more projecting epiplastral
lip, a differently shaped entoplastron and pectoral scutes narrower at midline.

This species is dedicated to Dr. W. J. Holland, director of the Carnegie Museum, Pitts-
burg, Pennsylvania.

TESTUDINID&. 45

Ww

Testudo turgida Cope.

Testudo turgida, Corr, Proc. Amer. Philos. Soc., xxx, 1892, p. 127; Amer. Naturalist, xxv1, 1892, p. 50;
3d Ann. Report Geol. Surv. Texas, 1891 (1892), p. 255; 4th Ann. Report Geol. Surv. Texas, 1892
(1893), p. 47-—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452.—GrpLey, Bull. Amer.
Mus. Nat. Hist., x1x, 1903, p. 627.

The type specimen of the present species belongs to the University of Texas. It was
discovered in the Blanco beds of the Pliocene, near Espuella, Dickens County, Texas. No
figures of the species have ever been publisht. The writer examined the materials in the
collection at the University of Texas, at Austin, but was not able to find Cope’s type of the
species. Remains of two or three other specimens of the species are in the collection, but a
description of them would add little to what Cope has recorded. This author’s description
is here reproduced. That found in the Third Annual Report, as cited above, is identical with
that found in the Proceedings of the American Philosophical Society. It runs as follows:

This species is represented by the greater part of a chelonite of about the size of the Xerobates agassizit
of Arizona. It is remarkable for the remarkable depth of the dermal sutures and sculpture lines, and
for the swollen character of the interspaces which separate both. The general shape is a short, wide
oval, with steep to vertical margins.

The plastron is widely emarginate posteriorly, and the anal-femoral dermal sutures form a deep
notch in the border. The anal scuta are oblique rhomboids, with equal and nearly parallel sides. The
median longitudinal dermal suture is deep and wide, cutting half through the thickness of the plastron.
It sends off a branch on each side bounding the gular plates in front. The part of the plastron inclosed
in the latter forms two flattened cones appressed together, whose vertical diameter exceeds the transverse,
and whose subconic apices are separated by a deep notch. The interclavicular bone is very large and
is wide diamond-shaped, the anterior angle being larger than the posterior. The transverse humero-
pectoral suture is very deep, and is similar to the median longitudinal. The borders of the anterior lobe
are strongly convex, with a chord only twice as long as the lateral border of the gular plates.

The nuchal bone has a strongly concave-emarginate border. On the posterior vertebral bones 1s a
seat-like cavity, which is surrounded by a ridge which forms the greater part of a circle. The costal bones
are unequally divided by the costal dermal sutures, which are very deep. Each costal scutum is divided
into two areas, one of which is marked with ribs parallel to the vertebral axis at one extremity and a
seat-shaped plane with a bordering ridge at the other, which is in some of the costals smaller and more
swollen. The other half or part of the scutal area is swollen in the longitudinal direction, but not for
its entire length. The marginal bones are massive and have a subacute border between the bridge and
the median points. They are much deeper than long, and are deeply divided by the sutures which
separate the dermal marginals. These grooves cut the margin into deep notches at some points and into
lower ones at others. The areas between these sutures are all swollen in the same way as the alternate

parts of the costal plates.
MEASUREMENTS.

Millimeters. Millimeters.

Length of plastron anterior to posterior angle of Diameters of free marginal near bridge:

TTECECG AV IGL@tetaccayertesy leds crieicie ee fale are 80 Antero-pOSstérior diecrocns ace sedcetinenes 2s 20
Width of plastron anterior to posterior angle of Vertical! 2 ccacciadéicseca 0 eats sarnaaatrasion 34

interclavicle.......... F ‘ ‘ 112 Transverse below......... Lee wssae ase) 2S
Length of interclavicle..... oeren HeeA0) Diameters of marginal of bridge:
Width of interclavicle.... 58 Antero-posterior ........ : ees
Thickness of interclavicle. . — : II Vertical ....... cece . : waits 4a
Length of free lateral margin of gular plate . 29 WPransverse:belowine sc 00 sees ser Sez
Width of base of both gular plates... 45 Diameters of penultimate vertebral bones:
Length of xiphiplastral bone. . eer) Antero-posterior .......... on 17
Width of xiphiplastral bone on anterior suture 53 Transverse - anid 30

Width of emargination of posterior lobe of plastron 50

The American tortoise which has produced gular areas somewhat like those of this species is the
Testudo cultrata Cope of the White River Neocene of Colorado. That species is however, totally
different in the dermal sutures of the usual character, flat marginals, etc., and the gular processes are

not conic, but trihedral in form.
The specimen above described comes from Espuella, near Dockum, from the same horizon as

that of Crosby County, or the Blanco beds of Cummins.

In the Fourth Annual Report, as cited in the synonymy, Professor Cope stated that
specimens of this species were found together at one locality, which did not yield any other
vertebrate remains. Fragments of 2 other individuals were found at other localities in direct
association with Mammalia.

454 FOSSIL TURTLES OF NORTH AMERICA,

Testudo pertenuis Cope.
Fig. 609.
Testudo pertenuis, Cope, Proc. Acad. Nat. Sci. Phila. 1892, p. 226; 4th Ann. Report Geol. Surv. Texas,
1892 (1893), p. 47, figs. 1, 2.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451.—GIDLEy,
Bull. Amer. Mus. Nat. Hist., x1x, 1903, p. 627.—Montcome_ry, Biol. Bull., vitt, 1904, p. 57-

The type and only known specimen belongs to the University of Texas. It was discovered
by Professor Cope in the year 1892, in the Blanco beds of the Pliocene, near Mount Blanco,
Crosby County, Texas. Of this species the writer
found in the University of Texas only three
or four large fragments which had been glued
to sheets a paper. These fragments may or
may not belong tothetype. The thickened por-
tions of the anterior and posterior lobes of the
plastron appear not to have been preserved.
It seems probable that the type was injured
before being returned to the collection at Austin.
Under the circumstances, nothing more can be
done than to republish Cope’s description and
his apparently more or less diagrammatic illus-
tration (fig. 609). In this figure, 1 represents
the carapace and part of the front of the plas-
tron seen from above. The other part of the
figure, 2, shows the hinder lobe of the plastron as
seen from above.

Founded on a large specimen measuring three
and a half feet in length by three in width, and re-
markable for the transverse width of the vertebral
dermal scuta. The carapace is rather flat and
descends steeply posteriorly, the anal marginal bone
— being somewhat incurved. Margins of carapace flare
outwards above the legs. The plastron has a rather
wide lip, with flat base and straight lateral borders;
its anterior border is lost. The posterior lobe is
deeply and widely notched, terminating on each side
in a subequilateral angular prominence. Both cara-
c.s. 1, first costal scute; ent, entoplastron; epi, epiplastron; — pace and plastron are without sculpture, the poste-

0-5. 2) Uess 5 first and fifth vertebral scutes. From rior angles of the plastron only being longitudinally

Cope’s figure. , i A

grooved below. The vertebral scuta are considerably

wider than long, as is also the anal scutum. Both carapace and plastron are very thin, not exceeding
one-quarter inch in the specimen described, except at the borders.

2
Fic. 609.—Testudo pertenuis. X's.

MFASUREMENTS.

Feet. Feet.
Length over all Ay te Length of last costal . Renee ene
Width over all 4 Width of lip of plastron at fy tye coders : 8
Width of penultimate dorsal scute 1.275 Width of anterior lobe at axilla. 2
Length: -.5<-c0tnans- 285 Width of posterior lobe of plastron a at base. sn
Width of last vertebral scute Lisi Width at fundus of median notch. F : RE
Width of anal scute. 1.5 Width at apices of angular processes. . eee 85
engthe eee .6 Depthyof notch. «0.2.22 «00 -. Somes)
Length of penultimate costal scute 9

This is the largest species of land-tortoise yet known from North America.

In its broad, deprest shell, with its broad vertebral scutes, this species appears to have
resembled somewhat 7. pansa, of the Pawnee Miocene. It differs, however, in several im-
portant respects. The carapace of 7. pertenurs is said to descend steeply behind and to have
the pygal somewhat incurved. In 7. pansa the rear of the shell slopes gradually downward
and backward, and the pygal is not at all incurved. The shell of 7. pertenuzs is stated to have
the borders flaring over the limbs, a condition not true in 7. pansa. The vertebral scutes of

TESTUDINID&. 455

T. pertenuis were evidently wider than those of 7. pansa. In the former the penultimate
vertebral had a width equal to 0.36 of the whole length of the carapace; while in 7. pansa the
corresponding scute has been only 0.26 as long as the carapace. ‘The epiplastral lip of 7.
pertenuis has had straight and, according to Cope’s figure, parallel lateral borders.

Testudo campester sp. nov.
Figs. 610-613.

T estudo campester, Hay, Bull. Amer. Mus. Nat. Hist., x1x, 1903, p. 627, in paper by J. W. Gidley and
without description.

The remains on which this species is based were collected for the American Museum of
Natural History during the summer of 1g00, by Mr. James W. Gidley. They were found in
the Blanco beds of the Pliocene deposits, near Mount Blanco, Crosby County, Texas. The
materials all belong to one individual, and consist of the nearly complete plastron, the lateral
and the posterior peripherals from one inguinal notch to the other, a portion of the nuchal
bone, 2 neurals and parts of a few others, and portions of several costals. The shell originally
had a length of about 730 mm. and a width of at least 560 mm. It was apparently of moderate
convexity and of medium height. The number of the specimen is 3930.

The greater portion of the plastron (fig. 610) is present, but it has suffered some damage
thru decay of the bone and loss of fragments. The total length equals 670 mm. It is
somewhat concave in the hinder half, and the anterior lobe was re above the plane of the
rest of the plastron. The length of the anterior lobe equals 180 mm.; its width, at the axillary
notch, has been close to 325 mm. From the axillary notch the ane of the anterior lobe 1s
moderately convex as far as the gular suture; from this point the outline changes its course
and runs in a straight line forw ard and inward to the outer anterior angle of the lip.

The lip was quite prominent. Owing to some damage to the plastron i in this region its
width can not be determined with all desirable exactness; but it was very close to 125 mm.
Its front is truncated or slightly convex and probably without notch; but the portion present
does not extend to the midline. The width of the base at the gular sutures was about 175
mm.; the length in the midline about 80 mm. The upper surface is slightly convex from the
midline to fhe! lateral border, and this convexity is continued backward to the posterior end of
each of the epiplastra. Antero-posteriorly the lip is very slightly convex above. The lower
side of the lip is convex both longitudinally and transversely. This convexity diminishes
backward, so that the hinder ends of the epiplastra are nearly plane. The free border of the
epiplastra from near the midline of the lip to their hinder ‘ends is rather sharply rounded.
From this border the bone thickens rapidly, so that at the middle of the length and breadth of
the epiplastron the thickness equals 46 mm., while at its hinder end the thickness is 37 mm.

Seen from above the thickness of the lip continues backward for about 100 mm. and then
becomes suddenly reduced. Whether or not there was an excavation behind the thickened
portion is uncertain.

Altho the entoplastron and the borders of the epiplastra joining it are somewhat eroded,
it is evident that the entoplastron itself was transversely oval. Its transverse width was close
to 160 mm.; its antero-posterior extent about 130 mm.

The antero-posterior extent of the hyoplastra in the midline is 155 mm. That of the hypo-
plastra is almost exactly the same. The xiphiplastra meet along the midline for a distance of
1o5 mm. At their anterior ends each has a width of 130 mm.

The posterior lobe of the plastron has a total length of 105 mm., and it is nearly 300
mm. wide. At its hinder extremity there is a right-angled notch whose width behind is go mm.
and whose depth is 45 mm.

Seen from above, the posterior lobe presents a broad, shallow basin, surrounded at the
sides by a bony wall. Just behind the inguinal notch this wall rises, from the lower side of the
plastron, to a height of 55 mm. Here the outer face of the bone overhangs somewhat. Furthe1
behind, the wall descends, and the outer face looks more and more upward and the summit of
the wall is rounded off. From the posterior part of this summit a low ridge runs to the tip of
each of the terminations of the plastron.

Most of the sulci separating the dermal scutes of the plastron are remarkable for thei
depth. Along the midline runs a groove so deep as to cut halfway thru the bone, and of about

450 FOSSIL TURTLES OF NORTH AMERICA.

15 mm. in width on the hinder lobe, and 30 mm. at the junction of hyoplastra and hypo-
plastra. The width on the entoplastron can not be determined, but it has caused the latter to
break along the midline. The gular sulci are not distinct, but they appear to have been broad,
and they extended on the entoplastron. The humero-pectoral sulcus starts, narrow and well
imprest, at the axillary notch, runs backward and inward nearly 75 mm., then turns sharply
and runs directly across the plastron, passing behind the entoplastron. The sulcus between
the pectorals and the abdominals is convex forwards. Laterally the pectorals have a width
of only 45 mm., but at the midline they are 75 mm. wide. The abdominals have a width of
175 mm. along the midline. The sulcus between these and the femorals is wide and deep,
and it runs directly across the plastron in front of the inguinal notches. The femorals extend
80 mm. along midline. The anal scutes meet along the midline fora distance of about 50 mm.

The inner half of the lower surface of each hypoplastron is markt by longitudinal grooves.

The remains of the carapace (figs. 611, 612, 613) of this species testify that it is a true
Testudo. One of the neurals (fig. 611) is octagonal, and the few costals present show that some

/

Fics. 610 AND 611.—Testudo cam pester. No. 3939 A. M.N. H.

610. Plastron. 4%. Partly restored in front.

611. Portion of anterior half of carapace. ><}. Most of nuchal and whole of first neural restored.

were broad at the proximal end and narrow distally, while others were narrow proximally and
wide distally.

The large octagonal neural is the second in the series. Its fore-and-aft diameter along the
midline is 67 mm.; its width across the middle of the length is 86 mm. The sides are concave,
the angles truncated. The third costal articulated with the right hinder angle of the second
neural. Its greatest width is 87 mm.; its distal width was about 50 mm.; its length about
240 mm. The second vertebral scute was about 160 mm. wide from side to side.

There is present the upper end of another costal plate, probably the fourth on the nght
side. The upper end is 48 mm. wide; the lower end of the fragment, perhaps a third of the
costal, is 75 mm. wide.

The proximal portion of the right first costal is among the remains. Its proximal end is
100 mm. wide and most of this is concave and was in contact with the first neural. The latter
must therefore have had convex sides. On the outer half of the upper surface of the first costal,
are several deep, wide, and curved grooves, which mark the stages of growth of the scute
which covered it. Similar grooves are found on other costals. The costals are about 13 mm.

in thickness.

TESTUDINID&. 457

A portion of the rear (fig. 612) of the carapace along, and for a short distance on each side
of, the midline is preserved. It includes the left hinder corner of the hexagonal sixth neural.
This is seen to have had a width, across the hinder end, of 74 mm. Behind it is a little more
than the left half of the seventh neural. This is broadest in front, and hexagonal, thru having
the anterior angles truncated; and with a maximum width of about go mm. The fore-and-aft
extent was about 50 mm. It is succeeded by the eighth neural, which has a length of about
40 mm. and a width of about 45 mm. Behind this is a fragment of the first suprapygal.
On it are indications of the fourth and fifth vertebral scutes. The exact length and breadth of
these can not be determined. The fourth was 80 mm. wide behind and the width increases
forward; while the fifth is 80 mm. broad at its anterior end and expands rapidly backward.

The thickened marginal portion of the nuchal bone (hg. 611) is among the remains. Its
extent along the front is about 105 mm. It is slightly emarginated at the midline, the edge is
abruptly rounded and from the front it thickens rapidly backward, until at a distance of 40 mm.
from the edge it is 42 mm. There appears to have been a nuchal scute 20 mm. wide. It is
quite probable that all the anterior peripherals were thickened and had obtuse edges. Large
portions of the peripherals from the axillary notches backward are present. Those behind the
inguinal notches are higher than long; subacute at the free borders, nearly vertical, not flaring,
except that the second and third on each side of the caudal peripheral flare slightly. The first
behind the inguinal buttress is 160 mm. high. Behind this the others descend, until the pygal
(fig. 613) is 115 mm. high at its lateral border. They are all about 80 mm. long at their free

O13a.

Fics. 612 AND 612.—Testudo campester. Portions of rear of carapace of type. }.
>] J 4

612. c.p.8, eighth costal plate of type; 7.7, 7.8, seventh and eighth neurals; spy, suprapygal.

613. Pygal and eleventh peripherals. a, section of eleventh peripheral; per. 11, eleventh peripheral; py, pygal.
borders. The pygal is notcht at its upper border for the second suprapygal, 95 mm. wide at
this border, and 65 mm. wide at the free border. The thickness of the peripherals is about 40
mm.; where they articulate with the costals and the pygal the thickness is about 15 mm. The
free border of the peripherals is very slightly notcht where it is crost by the sulcus.

It is proper to compare this species with others which have been described from the Plio-
cene deposits.

T. crassiscutata (Leidy, Trans. Wagner Free Inst., 11, 1899, p. 31, plate vi) differs in having
the plastron much broader at its hinder end and with a much wider and shallower notch. The
lip of the anterior lobe is also different.

T. hexagonata Cope, of the Equus beds of Texas (4th Ann. Rep. Geol. Surv. Texas, 1893,
p- 77; plate xxii, fig. 2) has both anterior and posterior lobes of the plastron quite different.
Especially is it stated that the sulci defining the pectoral scutes in front and behind approach
each other at the midline. In 7. campestcr these sutures are far apart at the midline.

T. laticaudata Cope, of the Equus beds of Texas (op. cit., p. 75, plate xxii, fig. 1), has the
anterior lip of the plastron notcht in the middle so as to be doubly convex, and the lower side
of the lip has two longitudinal fossz. The posterior lobe, with its notch, 1s also different, the
notch being much wider and much shallower.

458 FOSSIL TURTLES OF NORTH AMERICA.

T. pertenuis Cope, of the Blanco beds of Texas (op. cit. p. 47, figs. 1, 2), is a large species
with the bones of the carapace and plastron not exceeding about 6 mm. in thickness, except
at the borders. The bones are also devoid of sculpture. The depth of the posterior notch at
the plastron is very nearly half the width of the plastron at the bottom of the notch. In T.
campester the depth of the notch is not one-third of the width of the plastron at the point
indicated. The vertebral scutes of T. pertenurs were much wider than in T. campester. Those
of our specimen of the latter would be about 250 mm. wide if their ratio to the length of the
animal were the same as in 7. pertenuts.

T. turgida (Proc. Amer. Philos. Soc., xxx, 1892, p- 127) has not been figured. It also is
from the Blanco beds of Texas. So far as known it is a small species. ache anterior lip is
described as resembling two “‘flattened cones apprest together, whose vertical diameter exceeds
the transverse and where subconic apices are separated by a deep notch. Relatively to the
size of the animal the hinder plastral notch was much wider than it was in T. campester. Other
important differences appear on comparison of the descriptions.

Testudo obtusa (Leidy).
Figs. 614, 615.

Eupachemys obtusus, Leipy, Jour. Acad. Nat. Sci. (2), vill, 1877, p- 232, plate xxxiv, figs. 4, 5.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 448.

Eupachemys rugosus, Leipy, Trans. Wagner Free Instit., 11, 1889, p. 29 (errore).

Dr. Leidy’s Eupachemys obtusus was based on a single peripheral bone which was sent
to him by Prof. F. S. Holmes, this bone having been found in the phosphate beds of Ashley
River, South Carolina. The exact age of the fossil’ is impossible of determination; but its time
of existence was undoubtedly somewhere between the end of the Eocene and the beginning of
the Pleistocene. Dr. Leidy founded for this turtle the new genus Eupachemys, but he did not
attempt to define it. This name and the fact that he compared the bone with a peripheral of

Emys seem to indicate that he believed

PE ss . . - .
m4 ee the relationships of the animal to be
, ciel with the aquatic emyds. The bone
was evidently derived from a turtle
about a meter in length. None of the
4 Emydidz attains such great size, and

without other evidence the probability
would be that the animal was a species
of Testudo. To this genus it is here
referred. [here are some reasons for
suspecting that it 1s the same turtle
that was later described by Leidy
under the name Testudo crassiscutata.
614. 615. However, until more is known about
the two forms it seems best to retain
them distinct.

Dr. Leidy regarded the bone de-
scribed by himself as probably the
eighth of the left side. If this were true the anterior end might be expected to be thicker
than the posterior; but of this we have no evidence. The fore-and-aft extent of the bone
(fig. 614) is 120 mm. The height at the posterior end is 136 mm.; the greatest thickness,
72 mm. At the costal border the bone is thinned down to 15 mm. ‘The lower, or free, border
(fig. 615) is obtuse, a rare condition in turtles. What Leidy regarded as the upper surface, and
probably correctly, rises in a prominent fore-and-aft ridge just below the middle of the height.
From this ridge to the costal border the surface is concave; from the ridge to the free border,
itis plane. The lower, or inner, surface is strongly convex from the costal to the free borders.
The upper surface of the bone is rough and eroded. It exhibits no sulci separating the
marginal scutes. The inner surface is smooth and presents a longitudinal sulcus running
along near the costal border and more feeble indications of another that ran between the two

Fics. 614 AND 615.—Testudo obtusa. Outline and section
of type peripheral. 4.

614. Outline of upper surface. 615. Section at posterior end.

TESTUDINIDZ. 459

marginal scutes which occupied the bone. In fig. 615, which represents the posterior end of the
peripheral, the outer surface is toward the left hand.

In the collection of turtle remains from Peace Creek, Florida, Dr. Leidy found a thick and
rounded peripheral which he thought (Trans. Wagner Free Inst., 11, p. 29) might belong to
his earlier publisht Ewpachemys obtusa, which he referred to mistakenly under the name
Eu pac he PI VS rugoOsUS.

In the eellecuon of the U. S. National Museum at Washington there is a large peripheral
which was collected by Dr. W. H. Dall at Caloosahatchie, Blorida, It has a length of 145 mm.
The costal border is broken off. The free border is obtuse. The greatest thickness is 37 mm.
It is possible that it belongs to the present species.

Testudo crassiscutata Leidy.
Figs. 616-624.

Testudo crassiscutata, Leroy, Trans. Wagner Free Instit., 11, 1889, p. 31, plate vi, figs. 4-7; Bull. U.S.
Geol. Surv., No. 84, 1892, p. 129.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 451.

The materials described by Dr. Leidy under the above name consisted of a number of
fragments of one individual, mingled with a few fragments of the shells of two others. These
remains indicated a tortoise whose carapace measured about 1520 mm. in length. The
specimens are now in the U. S. National Museum and have the number 986. They were
discovered in the Peace Creek beds, at Arcadia, Florida. As the type those bones must be
taken which were figured by Dr. Leidy. These are the greater portion of the right epiplastron,

Fics. 616 AND 617.—Testudo crassiscutata.

Portions of plastron of type. ¢.

616. Portion of anterior lobe. 617. Portion of hinder lobe. " j Aa?
DLOE

| wise Gre ty
ae ae an, /
ai ; : 7 / /

i ‘4
4

bs

wrongly mentioned by Leidy as the left, a portion of the right hyoplastron, the thickened
borders of the hinder lobe of the plastron, the left femur, and the left tibia.

The anterior lobe of the plastron (fig. 616) had a length of 280 mm., measured at a mid-
line, and a width close to 475 mm. at the base. Dr. L eidy gives the width as 520 mm.; but he
measures outward to the middle of the axillary notch. From the base the lobe narrows rapidly
to the front, where the width is about 80 mm. The lip does not project beyond the general
curvature of the lobe, but it does project beyond the ends of the gulo- humeral sulci. From the

400 FOSSIL TURTLES OF NORTH AMERICA.

subacute free border of the lip the bone rises on the upper side to a point 105 mm. behind the
front and then drops off suddenly. The greatest thickness attained is 70 mm. The upper
surface of the lip is convex. There is no conspicuous notch where the gulo-humeral sulcus
crosses the border.

The entoplastron was about 245 mm. wide. Its length is conjectural. It was pointed in
front. Its greatest thickness at the midline is 70 mm., while the thickness of the hyoplastron
is 46 mm.

The hinder lobe (fig. 617) had a length of about 160 mm. along the midline and a basal
width of about 530 mm. Posteriorly there is a median notch 220 mm. wide and only 45 mm.
deep. At the inguinal notch, on the upper surface of the lobe, a great wall begins and runs
backward along the free border. The outer face of this wall is perpendicular and, at the
notch, 100 mm. high. At the femoro-anal sulcus the height is 40 mm., and the outer face is
inclined at an angle of about 45°. From the beginning the inner face slopes at an angle of
about 45°.

a : ees Bai:

Of ‘, Vag ie a nar a

\ / |
Z ve ay

4 i 2 “e
} s }
i \ 6 i
ee 7 nt \ ie) j
re 2 a, i i
f Yi . ;
p Lr - re
Me :
f

an

a8. (po
. ton
| |

Fics. 618-620.—T estudo crasstscutata. Neurals and costals. 4.
618. Third and fourth neurals. 619. Costal bone. 620. Costal bone.

In the U.S. National Museum is a collection of fossil tortoise bones, No. 4963, which were
collected near Tampa, Florida, by Mr. A. M. Lambert. They are believed to belong to this
species. There are 2 successive neurals, the third and the fourth (fig. 618). They are remark-
able for their size and great thickness. The third has a length of about 110 mm. and a width
of 155mm. Itis crost by a deep sulcus. From each end of the bone the surface slopes toward
this sulcus, so that the bottom of the latter is 15 mm. below the level of the ends of the bone.
The fourth neural, like that of most other species of the genus, is much larger than the third
and is octagonal in form. Its length is 130 mm.; its width, 200 mm.; and its thickness, 44
mm. Each side was in contact with the third, fourth, and fifth costals. An estimate makes it
probable that the carapace of this individual was about 4 feet in length.

Fig. 619 represents the proximal end of a costal belonging to this collection, either the third
or the fifth. Its greatest width is 150 mm., but at the distal end of the fragment the width is
reduced to r11 mm. At the proximal end the thickness is 40 mm. Here it was in contact with

TESTUDINIDZ. 401

3 neurals. The median vertebral scutes of this individual must have been about 240 mm.
long and about 300 mm. wide. A costal bone (fig. 620) very similar to this was figured by Dr.
Leidy in F. S. Holmes’s Post-Pliocene Fossils of South Carolina, plate xxviu, fig. 1. This
was secured from the Ashley River deposits and its age is uncertain. It now belongs to the
American Museum of Natural History. Its size is almost the same as that of the costal just
described. The thickness is 33 mm. It appears to belong to the present species, and to furnish
evidence that 7. crassiscutata lived during the time when 7. (Eupachemys) obtusa existed.
On the other hand, Dr. Leidy (Trans. Wagner Free Instit., 11, p. 29) mentions the finding,
among bones collected at Peace Creek, Florida, of a peripheral that resembled that forming
the type of T. obtusa. There is no certainty that 7. obtusa and T. crassiscutata are not one and
the same species, but for the present it may be better to regard them as distinct. With the
neurals and the costal of No. 4693 of the U. S. National Museum there is a posterior peripheral.
Its fore-and-aft extent is 115 mm. The height, following the curvature, is 220 mm. It
curves upward as the free border is approacht. This border is acute. The greatest thickness of
the bone is 35 mm. Prof. F. W. Putnam has given to the American Museum of Natural
History some turtle bones that were dredged in the Alifia River, Florida. The beds are
probably of the same age as the Peace Creek beds. Among these is a large peripheral, the
length of which along the free border is 148 mm. Fig. 621 represents a section of this bone.

6226.

Fics. 621 AND 622.—Testudo crassiscutata.

621. Section across a hinder peripheral. 4. No. 6094 A. M. N. H.
22. Left epiplastral of young individual. 3. a, upper surface; 5, section of symphysis; c, lower surface.

As will be seen, it is much turned upward toward the free border. The thickness 1s 35 mm.
The free edge is acute. It is possible that the obtuse peripheral forming the type of T. obtusa
belonged to the anterior part of the carapace, while the acute-edged peripherals just described
belonged posteriorly, Another peripheral from the Alifia River has a thickness of 48 mm.
Its free border is eroded away; but as far as represented the upper surface is concave.

The Jarman collection of fossil bones, made in Hillsboro County, Florida, and now in
Vanderbilt University, oe a left epiplastron which is referred with some doubt to this
species (fig. 622, a,b,c). If it is correctly identified it belongs to a relatively young and small
individual. The pace length of the bone is 82 mm.; the bone of type of the species was 270
mm. long. The feature in w hich the present specimen differs from that of the type is the great
thickness of the bone where it joined the epiplastron of the other side. In the type the greatest
thickness of the epiplastron is 70 mm. If the present specimen retained the same proportions
its thickness would be 21 mm. It is, however, 37 mm. thick. There is more or less variation
in these beaks among the Testudos and for the present it seems best to refer this specimen to
Leidy’s species. In fhe same collection is a peripheral that appears to be the right ninth, with
the costal border broken away. This peripheral has a length of 154 mm. along the free border.
The greatest height of the bone, as preserved, is 186 mm. ana this does not extend beyond the

402 FOSSIL TURTLES OF NORTH AMERICA.

costo-marginal sulcus. Where thickest, at the line where on the inner surface the horny scute
met the soft skin, the bone is 45 mm.; elsewhere from 22 mm. to 30 mm. Considering the
great thickness of the neurals and costals we might expect the peripherals of 7. crassiscutata
to be thicker than is the bone here described.

Testudo laticaudata Cooe.
Figs. 623, 624.

Testudo laticaudata, Cope, Geol. Sury. Texas, Iv, 1903, reprint p. 75, plate xxii, fig. 1.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 451.

The type of Cope’s T. laticaudata consists of a nearly entire right epiplastron, said by
Cope to be the left, and the greater part of the right xiphiplastron. These remains were found
by Prof. W. F. Cummins, of the Texas Geological Survey, in the Equus beds, on Rock Creek,
opening into Tule Canyon, in Briscoe County, Texas. These bones are now in the Univer-
sity of Texas, where the writer has been permitted to examine them.

The form of the anterior lobe of the plastron, as far backward as the hyoepiplastral
suture, can be seen from Cope’s figure here reproduced. The width of the lobe at the suture
mentioned was very close to 205 mm. The epiplastral lip was very slightly set off from the
remainder of the lobe and was rounded and slightly tootht in front. The lower surface of the
bone is in general flat, but on the lip there are two broad shallow fosse. The free border is
acute posteriorly, less so in front of the gulo-humeral sulcus. Along the epiplastral symphysis
the bone thickens a (fig. 624) rising to a height of about 42 mm. It then descends

624.

Fics. 623 AND 624.—T estudo laticaudata.

623. Right epiplastral and xiphiplastral bones forming type. >}. a, right epiplastron, lower surface;
b, upper surface of same bone; c, lower surface of right xiphiplastron; d, upper surface of same bone.
624. Section along symphysis of epiplastral bones. X 3.

perpendicularly until a thickness of about 20 mm. 1s attained. At the hyoepiplastral suture
the thickness of the bone has become reduced to 19 mm. Along the suture mentioned the
thickness is at first reduced slowly, then rapidly to the acute free border. The width of the
bone along this suture is 54 mm. The entoplastron had a width of about 100 mm. Its length
can not be determined.

On the lower side of the bone is seen a portion of the gulo-humeral sulcus. It crost the
entoplastron, then ran outward and forward, then outward and slightly backward to the free
border of the bone.

Figure 623 c, d, reproduces Cope’s figures of the right xiphiplastron, the part on the right
representing the upper side of the bone, “hat on the left the lower side. At the hypoxiphi-
plastral suture the free border is rather obtuse. From the border the bone thickens rapidly to
a thickness of 25 mm. Further backward the free border becomes acute and the maximum
thickness slightly less. At the midline behind it is 23 mm. The hinder angle of the bone is
curved slightly upward. The horn-covered surface on the upper face of the bone reaches the
free border at a distance of 15 mm. from the midline. The posterior notch was about 120 mm.

TESTUDINIDA. 463

wide. On the lower surface of the bone is seen the femoro-anal sulcus, running parallel with
the hinder border of the bone. The area occupied by the anal scute is rough and it occupies
a slightly different level from the rest of the bone.

As stated by Cope, this species may belong to the genus Gopherus (Xerobates), but this
can not be determined before the skull has been found.

Testudo hexagonata Cope.
Figs. 625, 626.

Testudo hexagonata, Corr, Geol. Sury. Texas, 1v, 1903, reprint p. 77, plate xxii, fig. 2—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 451.—GIDLEY, Bull. Amer. Mus. Nat. Hist., x1x, 1903, p.623.

The present species is based on a specimen now in the University of Texas, at Austin,
Texas, where the writer has been permitted to study 1 it. The specimen was found by Prof. W.F.
Cummins, of the Texas Geological Survey, in the Equus beds, on Rock Creek, a stream
emptying into Tule Canyon, in Briscoe County, Texas.

The carapace of this shell 1s considerably crusht and fractured, and somewhat weathered.
Various parts of the free border are missing. It is therefore difficult to secure the details of the
structure, and this portion of the shell was not described by Cope. A figure is here presented
(hg. 626) which gives as well as could be determined the structure of the carapace.

Fics. 625 AND 626.—Testudo hexagonata. Shell of type.

625. Half of lower surface of shell. From Cope’s figure. >}. 626, Carapace, partly restored. X$.

The length of the carapace is 380 mm.; the width, 330 mm. The peripherals in front and
behind the bridge appear not to have been flared upward to any considerable extent. Poste-
riorly the carapace appears to have been steep. Not much can be determined regarding the
arrangement of the neurals, on account of distortion. The first had a width of about 45 mm.
The ae is octagonal, with a length of 45 mm. and a width of nearly 70 mm. The third
was 4-sided. The second costal bone is narrowed proximally and greatly widened distally
being here about 65 mm. wide. The fourth and sixth costals have a similar form. The shicd
and fifth are widened proximally and narrowed at the distal ends.

464 FOSSIL TURTLES OF NORTH AMERICA,

The vertebral scutes are wide and strongly angulated where their lateral boundaries join
the intercostal sulci. The first is 130 mm. wide anteriorly and 70 mm. wide behind. The others
have a maximum width of about 130 mm.

The plastron was described and figured by Cope. His drawing 1s here reproduced (fig. 625).
When in Cope’s hands the epiplastral lip was present, but this is now missing. The length of
the plastron is given by Cope as 365, mm. This included the extremities of the hinder lobe on
each side of the notch. The anterior lobe has a width of about 180 mm. and, according to
Cope, a length of 89 mm. Cope states that the epiplastral lip had a simple regularly rounded
outline, which was distinctly set off from the rest of the anterior border. From his description,
confirmed by the impression on the matrix, the lip, at the symphysis, thickened rapidly back-
ward on the upper surface. A section along the symphysis would closely resemble that of T.
laticaudata. The thickness reacht was, according to Cope, 27 mm. The width of the lip at
the base was 90 mm.; the length on the midline of its upper surface, 40 mm. The hinder face
of the thickening was excay ae to form a thoracic cavity. Posteriorly the epiplastra were
greatly reduced in thickness, nowhere along the hy oepiplastral suture exceeding 11mm. The
bone thins gradually to the free border, so “that the hinder part of the epiplastron differs con-
siderably from that of 7. laticaudata.

The entoplastron was of hexagonal form, about 60 mm. long and 80 mm. wide. The
bridge has a width of 180 mm. The width of the hinder lobe may be regarded as 200 mm.
Cope g gives it as 240 mm., but he measures to the middle of the inguinal nofeles: The length,
to he extremities of the hinder angles of the xiphiplastra, is 100 mm. The notch behind is
about 80 mm. wide.

The gular scutes extended well backward on the entoplastron. The humerals extend 11
mm. behind the entoplastron, on the midline. The pectorals join at the midline a distance of 22
mm.; the abdominals, a distance of 120 mm.; the femorals, a distance of 42 mm.; the anals,
a distance of 40 mm.

The free border of the xiphiplastron is acute from the hinder angle to near the hypoxiphi-
plastral suture. As the latter is approacht the bone thickens to 25 mm. and the free border
becomes obtuse.

Cope states this species may belong to the genus Gopherus (Xerobates), but this can not
be settled before the skull is found.

Testudo atascosze Hay.
Figs. 627-628.

Testudo atascose, Hay, Proc. Acad. Nat. Sci. Phila. 1902, p. 383, figs. 1-5.
, 902, P- 393, ng: 5

In the collection of the Academy of Natural Sciences of Philadelphia the writer has found
certain bones which belong apparently to an undescribed species of the genus Testudo. These
bones are accompanied by a label to this effect: ‘‘ Miocene, E. W. Marnock, Atascosa County,
Texas.’”’ There is no record of how this material came to the Academy. Mr. Witmer Stone has
pees that it may have been derived from Dr. Leidy’s collection; we know also that Mr.

W. Marnock collected in Atascosa County, Texas, for Professor Cope, but beyond this
ae is no indication that these bones were ever in the hands of either Professor Cope or Dr.
Leidy. The initial ““E” in the name above given is probably an error for G.

These remains consist of the left half of ele anterior lobe of the plastron and the greater
portion of the left side of the hinder lobe. Figures of these parts are presented (figs. 627, 628).

The species was one of considerable size. The xiphiplastron had a length of about 110 mm.,
the whole posterior lobe a length approximately of 120 mm. The anterior lobe had about the
same length. We may perhaps safely estimate 200 mm. for the length of the bridge, thus mak-
ing the plastron 440 mm. long.

The anterior lobe (fig. 627) was close to 200 mm. in width. The entoplastron had a width
of 100 mm.; its length was probably about 80 mm., but its hinder border is missing. The
gular scutes encroach on its anterior border. A broad rounded lip projected beyond the gulo-
humeral sulci about 28 mm. It had a width of 80 mm., and is not notcht in front. The whole
border of the anterior lobe is acute, thru the beveling off of the upper side. Figure 627 repre-
sents a section thru the lip at the midline and shows this beveling. The greatest thickness at

TESTUDINIDA. 405

the lip is 23 mm.; at a point halfway to the axillary notch this thickness is reduced to only
21 mm.; near the notch it is about 10 mm. Superiorly the lip extends back about 50 mm.
From the summit of the lip two ridges, with a shallow valley between them, run toward the
axillary notch, diverging gently. There was evidently no thoracic excavation in the hinder
face of the lip.

The posterior lobe (fig. 628) was broadly notcht behind, the notch having a width of about
go mm. and a depth of 35 mm. The terminal lobules are directed outward and upward, ear-
like, somewhat as they are in Gopherus polyphemus, but not so narrow as they are in the latter.
From the midline behind, the border is acute around the lobules and as far forward as about
35 mm. behind the hypoxiphiplastral suture. Here it rather suddenly becomes broadly rounded
as shown by the cross-section (fig. 628a). At the suture mentioned the thickness of the bone
is 30mm. The wall thus formed continues backward, descending somewhat, and meets the

6274.

628a.

627. 628. 628).
Fics. 627 aND 628.—Testudo atascose. Plastron of type. 4.

627. Anterior lobe; a, section of epiplastral symphysis.

628. Hinder lobe; a, section at hypoxiphiplastral suture; b, at extremity of xiphiplastron.
midline 15 mm. or more in front of the bottom of the notch. Fig. 6284 presents also a section
thru one of the lobules in a direction from its tip toward the center of the hinder lobe. The
greatest thickness is 22 mm.

The femoro-anal sulcus runs from the midline outward, so as to make the outer end of the
anal scute somewhat wider than the mesial end. Antero-posteriorly, at the middle of its width,
the scute is 40 mm. long.

The deposits in which this tortoise was found belong to the Equus beds of the Pleistocene.

In the same region Mr. Marnock collected Terrapene marnochi (Cope) and Trachemys
bisornata (Cope) (Proc. Amer. Philos. Soc., xvi, 1878, pp. 228, 229; Amer. Naturalist,
xxi, 1889, p. 161).

It is not improbable that this species belongs to the genus Gopherus.

Superfamily TRIONYCHOIDEA.

Thecophora with skull and neck in all essential respects like the same parts in the Crypto-
dira. Horny jaws concealed beneath fleshy lips. Peripheral bones rarely present. Plastron
ligamentously connected with the carapace. Epiplastra separated from the hyoplastra by the
entoplastron. Pelvis not suturally connected with the carapace and plastron. So far as known,
no epidermal scutes.

Of the Trionychoidea, 2 families are here recognized—the Trionychide and the Plasto-
menida. The former family is represented by numerous living species; the latter is extinct.

In his Bibliography and Catalogue of the Fossil Vertebrata of North America, constitut-
ing Bulletin No. 179 of the U. S. Geological Survey, publisht in 1902, the author regarded

30

66 FOSSIL TURTLES OF NORTH AMERICA.
4

the Trionychoidea as one of three suborders of the Testudines, the other two being the Athece
and the Thecophora. Further consideration of the subject has convinct him that the group
is too closely related to the Cryptodira to justify such a wide separation of the two. On the
other hand, there are structural differences of too great value to permit the trionychids to be
reduced to the status of one or two families under che Cryptodira. It is now believed that their
relationships to other turtles will be correctly exprest by making them a superfamily of the
Thecophora, the other superfamilies being the Amphichely dia, the Cryptodira, and the
Pleurodira. This classification is that adopted by Dr. Boulenger in his Catalogue of Chelon-
ians, etc., in the British Museum.

For a discussion of the structure and relationships of the trionychids the reader is referred
to Baur’s papers in the Zoologischer Anzeiger, vol. x, 1887, p. 96; vol. x1, 1888, p. 7363 vol. x11,
1889, pp. 241-243, and American Naturalist, vol. xXxtv, 1870, p. 530; Dr. Boulenger’s catalog
referred to above, and to a paper by the present writer (Bull. Amer. Mus. Nat. Hist:, x1,
1905, pp- 137~175). For a discussion of Haeckel’s view that the Trionychoidea are the most
primitive of ihe Thecophora the reader is referred to page 25 of the present work.

The geographical distribution of the living Trionychidz is discust on page 35 and is
illustrated by fig. 16.

Family PLASTOMENID Hay.

Trionychoidea with skull like that of the Trionychide. Neck unknown, but probably
like that of the Trionychide. No peripheral bones. Epiplastra separated from the hyoplastra
by the large, crescentic entoplastron. Hyoplastra, hypoplastra, and xiphiplastra closely united,
as in the Emydide. Feet unknown.

the genus Plastomenus Cope. ‘The eeeichite of f this, so far as Neeneeas has been ea
from the Bridger species. The cervical vertebra and the feet are unknown.

The Plastomenide differ from the Trionychide, so far as known, principally in the
structure of the plastron. In the latter family the ventral armor differs much from that of the
Cryptodira. The bones have suffered reduction, so that great fontanels intervene between the
bones of the opposite sides and between the entoplastron and the hypoplastra. The ento-
plastron 1s V- shaped and excludes the epiplastra from the hypoplastra. In the Plastomenidz
the three hinder pairs of bones join their fellows closely at the midline, as in the Cryptodira,
and the hypoplastra are closely sutured to the hyoplastra and to the xiphiplastra. There
appears to have been little space between the entoplastron and the hypoplastra. Indeed, the
plastron is more completely closed than in the Chelydride and Cheloniide. Furthermore,
the entoplastron, if we may form our conclusion from Plastomenus edemius, was broad fore
and aft and elongate kidney -shaped. We do not know what were the form and connections of
the epiplastra.

A peculiarity of structure displayed by some species of the family is the great development
of the eighth pair of costals. In most species of Trionychide the eighth Goutal are greatly
reduced ands in some cases wholly wanting. In Plastomenus thomast and some other species
this pair of costals is greatly developt. The character does not, however, appear to be shared
by all the species.

Genus PLASTOMENUS Cope.

At the present time the generic characters of Plastomenus can not be separated from those
assigned above to the family. So far as known there is present a preneural bone, and some of
the hinder neurals are wanting.

Type: Plastomenus thomas Cope.

Professor Cope’s first definition of the genus Plastomenus (Proc. Acad. Nat. Sci. Phila.
1873, p. 278) is hardly sufficient to distinguish it from other trionychids. For a reason which
the present writer does not understand he concluded that there was present ““a nuchal marginal
which does not exist in Trionyx,” but no such bone has been shown to have existed. He was

PLASTOMENID&. 467

especially struck by the configuration of the inner end of the hyoplastral bone, which appeared
to him greatly different from that of Trzonyx,; but he does not mention the condition of the
median and hinder portions of the plastron.

In 1877 (Wheeler’s Sury. rooth Merid., 1v, p. 47), Cope concluded that the hyoplastrals
were not greatly different from those of Te while the hypoplastrals were materially
different. ee are stated to have displayed a transverse width behind the inguinal region
more like an emydoid than a trionychoid genus. The more extended ossification of all these
bones in Plastomenus than in other genera of trionychids was recognized. Cope’s remarks
on the genus in the work referred to were copied into his work of 1884: on the vertebrates of the
Tertiary formations.

Even as late as the year 1882 (Amer. Naturalist, xvi, 991) Professor Cope was uncertain
whether or not this genus belonged to the Emydidz.

Several of the species referred to this genus are based on very fragmentary and incomplete
materials, and it is not improbable that ravtien more complete remains shall have been dis-
covered some of these species will have to be placed in other genera.

ANALYSIS OF SPECIES REFERRED TO PLASTOMENUS.

A‘. Judith River and Laramie species:

1. Costals with angular pits, 5 in 10 mm., and crost by prominent welts. costatus
A*, Arapahoe species:
2. Costals without welts; pits fine, not angular, 6 in 10 mm punctulatus
3. Costals not known; free border of hypoplastron acute; lower surface with
angular pits . ; - insignis
A*, Puerco or Torrejon species:
4. Carapace with welts. Carapace and plastron with small pits............... acupictus
A‘. Wasatch species:
5. Like P. thomas, but ridges between pits broader; 7 pits in a line 15 mm. long catenatus
6. Costals thick; pits on distal ends of costals in rows; 3 or 4 pitsinaline of 10 mm. — /eptomitus
7. Costals thick; sculptured with pits and welts; pits circular, 7 on 10 mm....... lachrymalrs
8. Costals of moderate thickness, pits angular, 7 in 10 mm; some of the intervening
ridges weltlike ......... ; Se Tne kaa oes en ee 5 AS fractus
g. Pits of costals abruptly sunken: 5 in 10mm.; no welts ; _plastron with ver-
miculate ridges. ... : : sae fe corrugatus
10. Costals thick; pits circular, 4 in 10 mm. n.; oblique welts on some costals; plastron
with rows of circular pits . . fork sean communis

A®. Bridger species:

i. Carapace with welts and pits; four ian ina 10 mm. line. Costals of eighth

pair as long as wide.......... Bae oft Pie nates chit Mein te hry evan aint nial thomast

12. Carapace with welts and pits; five: or siX pits in 10mm.; eighth costals much
shorter than broad ; visendus

13. Carapace with welts and pits; eight pits in 10 mm.; hinder cost. ils about as
NST Seta Sew Cae, Meme re onset ene oe telat asic SB celal a cence ORs ; ; tantillus
14. Carapace with welts on hinder ae igaree or fous pits in 1omm..... @demuius
15. Like edemius but with from five to seven pits in 10 mm..... molo pinus

Plastomenus costatus Cope.
Plate 85, figs. 1, 2.

Plastomenus costatus, Copx, Vert. Cret. Form. West, 1875, pp. 94, 261, plate viii, fig. 8; Proc. Acad.
Nat. Sci. Phila. 1875, p. 9; Brit. N. A., Bound. Comm. Report on Geol. etc., 1875, p. 337.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452.—Harcuer, Bull. U.S. Geol. Surv. No. 257, p. 74.

This species was described from materials collected by Dr. G. M. Dawson, south of Wood
Mountain, Assiniboia. The deposits from which they were derived were supposed to belong
to the Laramie, but are now known to belong to the Judith River. These materials are now
the property of the Geological Survey of Canada. They consist of a piece of a costal, a frag-
ment of probably the right hypoplastron, and another small undetermined fragment. The
costal fragment was figured by Cope as cited. The bone is remarkable for the relative thick-

468 FOSSIL TURTLES OF NORTH AMERICA.

ness of the portion occupied by the rib. Some of Cope’ s measurements appcan to be slightly
erroneous. The thickness of the edge of the bone is nowhere quite 5 mm.; where thinnest
only 3mm. The thickness thru the rib is a little less than gmm. The Border of the plastral
fragment is 10 mm. thick. The ornamentation of the surface of the costal is distinct and
peculiar. There are about 5 of the angular pits in a line 10 mm. long.

The fragment of the plastron appears to be a portion of the right hypoplastron extending
from the inguinal notch backward. There are some indications that it extended to the xiphi-
plastral suture. The free border is rounded.

There are in the American Museum some portions of a carapace and a plastron which
were collected by Mr. Barnum Brown in 1902, in Laramie deposits, 12 miles south of the
Missouri River, on Hell Creek. The locality is 130 miles west of Miles City, Montana. It is
not certainly known that the various bones belong to the same individual. Their number in
the American Museum is 6131. Figure 1 of plate 85 represents the distal end of one costal,
as seen from the upper surface. The thickness at the articular border is 5 mm.; that thru the
rib is 8 mm. In this specimen, as in Cope’s type, the rib stands out on the lower surface of
the bone with great distinctness. It likewise extended a considerable distance beyond the free
border of the costal. These borders are beveled off obliquely to the upper surface. The
ornamentation consists of a network of ridges, which anastamose irregularly and inclose pits
and winding and interrupted valleys. The ridges are rather low, and there are from 4 to 6
of them in a line 10 mm. long. On the costal plate here figured we find 2 welts crossing it,
such as we find in P. thomas:. Another costal does not show these.

Figure 2 of plate 85 represents the right xiphiplastron. A comparison of this bone with that
of P. thomas: will reveal many similarities. There is no doubt that this bone articulated with
the one of the opposite side thruout its entire length. At the anterior end of this median border
there are two processes which entered pits in the opposite bone and received between them a
process from that opposite bone. The anterior border also almost certainly articulated its full
length with the hypoplastron. At the outer anterior angle there are two strong processes
for digitation with the hypoplastron. At the base of these processes the thickness is 12 mm.;
while at the median border the thickness is 5 mm. The sculpture of the bone agrees well with
that of the portion of plastron described by Cope. It is similar to that of the carapace but the
pits are not so deeply imprest. It covers the whole lower surface of the bone.

Plastomenus? punctulatus Cope.

?Plastomenus punctulatus, Copr, Ann. Report U.S. Geol. and Geog. Surv. Terrs., 1873 (1874), p- 4533
Bull. U.S. Geol. and Geog. Surv. Terrs., 1, No. 2, 1874, p. 29; Vert. Cret. Form. West, 1875, pp. 94,
261, plate vi, fig. 9.

?Plastomenus punctulatus, Core, Bull. U.S. Geol. and Geog. Surv. Terrs., 111, 1877, p- 573:

Plastomenus punctulatus, Hay, Buibliog. and Cat. Foss. Vert. N. A., 1902, p. 453.—Hatcuer, Bull.
U. S. Geol. Surv., No. 257, 1905, p. 74

Cope’s type of the present species consists of only a fragment of a costal plate, which the
describer figured in his monograph on Cretaceous vertebrates, as cited above. This type is
now in the American Museum and has the catalog number 1845. It was collected in north-
eastern Colorado, in association with the type of Trionyx vagans Cope; and therefore on
Bijou Creek, in deposits believed by Whitman Cross to belong to the Arapahoe formation.
Professor Hatcher, as cited above, thought that the ty pe locality was doubtful, because Cope,
in his latest description ( (Vert. Cret. Foam West, p. 94) says that the species was “‘established
on a costal bone in association with the preceding species,” and the “preceding species”
there is Plastomenus costatus, of the Judith River beds of British America. This comes from
Cope’s having transferred without change his original description, which was preceded by
his Trionyx vagans, to his monograph, w here it was ; preceded by Plastomenus costatus. There

can be no doubt whatever that the present species was found on Bijou Creek, Colorado. The

type is accompanied by a label in Cope’s handwriting as follows: “‘ Plastomenus punctulatus,
10-9-1873, Colorado.” Cope states that he had examined several fragments of the same
species that had been collected by Dr. Hayden at Long Lake, in the present state of North
Dakota; but at present we can not depend on the determination.

PLASTOMENID&. 4009

No additional material having been discovered, we can do little more than reprint Cope’s
description:

Established on a costal bone found in association with the preceding species, and referred to the
genus Plastomenus provisionally, and with a probability that it will be found not to pertain to it when
fully known. That genus has so far only been found in the Eocene formation. The bone is rather thin
and sufficiently curved toindicate a convex carapace of moderate thickness. The surface is marked
with closely packed shallow pits without material variation of form on the proximal end of the bone.
The result is an obsolete sculpture quite similar to that seen in some species of the genus to which it
is at present referred.

MFASUREMENTS.

Meter.
Width of costal bone 0.0230
Thickness of costal bone 0033

Number of pits in 0.010 meter, 6.

Lignite Cretaceous of Colorado; also several fragments from Long Lake, Nebraska, from Dr.

Hayden.

It will be observed that the pits of this carapace are small, and measurements made on
the specimen show that there are sometimes seven pits in a line ro mm. long. The thick-
ness of the bone at the neural border is nearly 5 mm.; thru the swelling Giiced by the rib on
the under side, it is 5 mm. Cope’s measurement was taken at the sutural border.

The type locality being known, it does not appear necessary to despair of finding and
identifying other specimens of this trionychid.

It is possible that this species belongs to the genus Plastomenus, but of this we can not be
assured before additional carapacial materials shall have been found accompanied by the
plastron.

Plastomenus? insignis Cope.

Plastomenus? insignis, Cope, Ann. Report U.S. Geol. and Geog. Surv. Terrs., 1873 (1874), pp- 43354543
Bull. U. S. Geol. and Geog. Surv. Terrs., 1, No. 2, 1874, p. 29; Vert. Cret. Form. West, 1875, pp. 95,
261, plate vi, fg. 10.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452.—Hartcuer, Bull.
U. S. Geol. Surv. No. 257, 1905, p- 75

This species was based on a single fragment of the hypoplastron, presenting a part of the
free border of the hinder lobe close to the inguinal notch. This type belongs to the American
Museum of Natural History and has the number 1846. It is accompanied by a label in Cope’s
handwriting as follows: “ Plastomenus 1 mmstgnis. 10-9-1873, Colorado.” In his description
Cope states that this specimen was found in the same locality as his P. punctulatus; and as
shown under the latter species, page 468, this locality was somewhere on Bijou Creek, Colorado.
The formation is believed to be the Arapahoe. Professor Hatcher regarded the type locality
as doubtful, and this species as therefore worthless from a biological and a stratigraphical
point of view. There can be no doubt about the type locality, and the present writer believes
that it will be possible to identify other materials coming from this locality and having the same
part present.

The fragment has a length of 23 mm. and a width of 11.5 mm. It extends forward to the
suture with the hyoplastron and backward nearly, if not actually, to the suture with the
xiphiplastron. The acute free border of the bone extends forward within 10 mm. of the
hyohypoplastral suture. This fact shows that the species must have been a small one,
perhaps not more than 150 mm. long. At the suture with the hyoplastron the bone is 4
mm. thick.

Cope states that the suture with the xiphiplastron was gomphosial. At the hinder end of
the bone there is a smooth pit which may have received a process from the xiphiplastron.
The writer can not convince himself that any other part of the suture is present. There
is no excavation of the free border for a forw ardly directed process of the xiphiplastron, such
as we might have expected.

The specimen affords no characters that confirm or that refute the reference of the species
to the genus Plastomenus.

470 FOSSIL TURTLES OF NORTH AMERICA.

Plastomenus acupictus Hay.
Fig. 629.
Plastomenus acupictus, Hay, Bull. Amer. Mus. Nat. Hist., XX111, 1907, p- 852, plate liv, figs TS 25

text-fg. 8.

The fragmentary remains of this species are a part of the Cope collection in the American
Museum of Natural History. The catalog number is 1025. The bones were collected for
Professor Cope many years ago, apparently from Torrejon
deposits, in New Mexico, by Mr. David Baldwin. The
individual was a small one.

A costal bone, believed to be the third, is 10 mm. wide
and 3 mm. thick at the neural border. The seventh costal
is 16 mm. wide at the distal end, 3 mm. thick at the sutural
SS edge, and 4.5 mm. thru the ridge formed by the rib.

On the hinder costals are seen 6 or 7 welts. The pits
covering all the upper surface except the beveled free bor-
der, are unusually small, there being § in a line 5 mm. long.

The hinder lobe had a width of about 60 mm. at the
base. The suture between the hypoplastron and the xiphi-
plastron (fig. 629) is 27 mm.long. At the bridge the hypo-
plastron is 8 mm. wide and 5 mm. thick. As in other
species of the genus, there seem to have been no fontanels
on the midline of the plastron.

Fic. 629.—Plastomenus acupictus. There are no welts on the plastral bones and the pits
Plastron of type. X 1. are somewhat smaller than on the carapace.

neon

Plastomenus catenatus Cope.

Plate 86, fig. 1.

Plastomenus catenatus, Cope, Syst. Cat. Vert. Eocene New Mexico, p. 35; Ann. Report Chief Engineers,

1875, Append. LL, p. 1016 (of reprints, p. 96).
Plastomenus multifoveatus, Cope, Wheeler’s Report Surv. West tooth Merid., 1877, Iv, p. 49, plate xxv,

hg. I

The fragment of costal plate on which Cope based the present species is in the U. 5.
National Museum and bears the number 1138. It was discovered in the Wasatch Eocene
beds, in the region of the Gallinas River, New Mexico. When Cope came to figure the speci-
men, in 1877, he had come to the conclusion that it belonged to a species that he had already
described from the Bridger beds of Wyoming, a species which he called P. multifoveatus, but
which is here described as P. thomas. The present writer has examined the type of P. catenatus
and has become convinct that it belonged to a species distinct from the Bridger form men-
tioned. As the fragment has already been named, figured, and described, it appears to be
best to retain for it ake original name and await the finding of additional materials from the
type locality. Cope’s figure of the fragment is reproduced on plate 86, fig. 1

The piece of costal is 25 mm. wide, 4 mm. thick. The ridges separating the pits are
wider than in the case of P. thomasz, and the slope into the pits is more abrupt. Ina line 15
mm. long there are 7 of the pits. In some cases two or more of them appear to have coalesct.

Plastomenus? leptomitus (Cope).
Plate 86, fig. 2; text-fig. 630.

Trionyx leptomitus, Cope, Syst. Cat. Vert. Eocene New Mexico, 1875, p. 353 Append. Lr, Ann. Report
Chief E ngineers, 1875, p- 1015 (separata, p. 95)5 Wheeler’s Surv. W. tooth Merid., tv, 1877, p. 44,
plate xxv, figs. 27-31, plate xxvi, figs. 1-4.; Vert. Tert. Form. West, 1884, p. 118.—Kine SUD
Geol. Explor. goth Parallel, Syst. Geol., 1, 1878, p. 377-—Hay, Bibliog. and Cat. Foss. Vert. N.
A., 1902, p. 454.

The known remains of this species were collected by Professor Cope in the year 1874, in

deposits belonging to the Wasatch formation, in Rio Arriba County, New Mexico. These
specimens are now in the U. 8. National Musews: at Washington, and bear the numbers

=

PLASTOMENID#. 471

1110 and 1113, the specimens appearing on Cope’s plate xxvi having the latter number.
Professor Cope states (Syst. Cat., p. 35) that 4 individuals were represented in his collection.
All these, if Ub present, are included under the catalog numbers just given. The originals
of Cope’s figs. 1, 2, and 3, of his plate xxvi, were considered by him to constitute the type of
the species, aad are said to belong to a single individual. Fig. I represents the outer end of
the left hypoplastron; hg. 2, apparently a “fragment of the left hypoplastron at the bridge;
while Cope’s fig. 3 1s the distal end of a Gaal In Cope’s fig. 2 the left side represents the
sutural border for articulation with the hyoplastron, and the concave edge on the upper right-
hand side is the inguinal notch, which is here quite acute. If this identification of the bone is
correct, the notch was more abruptly formed than is usual in species of Trionychide, and
quite as abruptly as in Plastomenus thomas:. In order to understand the relations of the bones
represented by the two figures, fg. 2 must be conceived as being removed to the left of fig.
in such a way that the left edge, the sutural one, shall be turned go degrees and placed about
parallel with the upper border of fig. 1. When the two figures are thus placed, there should be
perhaps about 35 mm. of space between their lower borders. Fig. 630 represents these bones
in the position suggested.

The fragment of costal plate represented by Cope’s fig. 3, plate xxvi, has a thickness of
10mm. The figure is reproduced (plate 86, fig. 2). The upper surface is beveled off some-

what and the upper layer of bone oy erhangs the deeper

layers. The upper surface of the bone is sculptured with

Pee narrow ridges which run parallel with the free border of

= the costal. Between these sharp ridges are furrows,
which are occasionally divided into pits by intersecting
ridges. There are 4 of these furrows in a distance ae
10 mm. QOne tragment of the upper end of a costal is
found with the type. It shows the rib-head and was
originally about 20 mm. wide. ‘The thickness at the

Combination of two of Cope’s fig- Satara border is 6 mm.; thru the rib it is 7 mm. The

ures to show their relative positions. angle between the articular border for the cor eee

x4. No. 1113 U.S.N.M. Type. neural and that for the outer hinder angle of the neural

next in front shows that the neurals were much wider

behind than in front. The upper 25 mm. of the upper surface is covered with large irreg-

ular pits, about 3 in 10 mm. Distally they become smaller. It is possible that this fragment

does not belong to this species, but other fragments appear to form the transition to the
original of Cope’s fig. 3, plate xxvi.

The fragments which belonged to Cope’s third specimen, and which furnisht figs. 27 to 31
of his plate xxv, belonged to a larger animal. It is possible, too, that they belonged to a
distinct species. As in the type, the costal is thickened distally and the sculpture consists of
ridges crossing the costal and connected at intervals by intersecting ridges. In the type of the
species the ridges are of nearly uniform size or perhaps they increase slightly in breadth and
distance apart toward the free margin of the costal. In the third specimen, however, they are
broader and more obtuse and they become distinctly narrower and more crowded toward
the margin, as is shown in Cope’s figures. Furthermore, the sculptured layer of the type
overhangs the deeper layers, at the fee margin, more than it does in the originals of Cope’s
figs. 29-31. All these differences may, however, be due to variations in age and size or to
varying positions in the carapace.

In the lot of bones representing this species there is a portion of a plastron, apparently a
part of the left hypoplastron from the inguinal region, and hence corresponding to the piece
represented by Cope’s fig. 2, plate xxvi. This presents a sculpture in which the ridges run at
right angles with the hyohypoplastral suture. At this suture the thickness is 8 mm., but nearer
the free border it is 15 mm. An outer extremity of a hypoplastron in the lot shows a sculpture
different from that of the type individual, and more like that of 4myda ventricosa.

More and much better materials are needed in order to determine the structure and
relationships of this tortoise. The form of the hypoplastron of the type and to some extent
the sculpture of the carapace seem to indicate that the species belongs to, or is near, the genus
Plastomenus.

Fic. 630.—Plastomenus le ptomttus.

472 FOSSIL TURTLES OF NORTH AMERICA.

Plastomenus? lachrymalis Cope.

Plate 86, fig. 3.

Plastomenus lachrymalis, Core, Append. FF, Ann. Report Chief of Engineers, 1874, p. 603 (of separata,
p- 96); Syst. Cat. Vert. Eocene N. Mex., 1875, p- 35; Wheeler’s Surv. W. tooth Merid., rv, pt. 11,
1877, pp. 48, 51, plate xxv, figs. 7-76; Vert. Tert. Form. West, 1884, p. 123.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 452.

This insufficiently known species was secured by Cope in the Wasatch deposits of New
Mexico. It was based on a single individual and apparently on only fragments of costal plates.
Of these 2 were figured. These remains were evidently referred to Plastomenus because of
the character of the sculpture. We can not be sure of the correctness of this assignment before
similar costals shall have been found associated with the plastral bones. The writer does not
know where the specimen now 1s.

Professor Cope’s description is given below, and one of his figures, that of the distal end
of a costal bone, is reproduced on the plate referred to above. The part of the figure indicated
by a shows the thickness of the bone.

Costals with finer pits [than in P. sertalzs], the welts broken into tubercles posteriorly.

The largest species of the genus represented in the Eocene of New Mexico. The costal bones are
rather finely punctate, the posterior as well as the anterior. The anterior costal bones are crossed by
numerous ridges from side to side obliquely; the obliquity increasing posteriorly. On the posterior
bones they are broken into vertical bars, separated by considerable intervals, and of linear form. The
posterior costals reach a thickness of 0.006 m. and a width of 0.025 m.

The pitting of the posterior part of the carapace distinguishes this species from the P. wdemius.

But one specimen obtained.

Plastomenus? fractus Cope.
Plate 86, fig. 4.

Plastomenus fractus, Cope, Syst. Cat. Vert. Eocene New Mexico, 1875, p. 35; Append. Li of Wheeler’s
Report to Chief Engineers, 1875, p. 1016 (of separata, p. 96); Wheeler's Surv. W. tooth Merid.,
Iv, pt. ii, 1877, p. 49, plate xxv, figs. 12-19; Vert. Tert. Form. West, 1884, p. 123.—Hay, Bibliog.
and Cat. Foss. Vert. N. A., 1902, p. 452.

The types and all other specimens of this species having apparently been lost, the present
writer must content himself with reprinting Cope’s description and one of his figures. It
may be said, however, that there 1s nothing about the specimens or the description that either
confirms or disproves the correctness of the reference of the species to the genus Plastomenus.
Important parts of the plastron are needed for the settling of this question. The species
comes from the Wasatch beds of New Mexico; but the exact locality was not given by Cope.
It was, however, from the region of the Gallinas River.

Five individuals in a fragmentary condition represent this turtle, and present greater uniformity of
character than some of the others. The sculpture is a honeycomb, where the fosse are wider than the
separating ridges, [and] which is traversed at intervals of two or three fossa by elevated lines, which are
transverse or oblique to the long axis of the costal bones as they are situated in the carapace. These
lines are elevated portions of those separating the fossa, and hence differ entirely from the smooth, thick
welts of the species of the genus which follows. They are usually zigzag in their course, as defining the
pits, and sometimes inclose small pits. The vertebral bones are strongly pitted. None of the specimens
indicate large size.

MEASUREMENTS.

Meter.
Width of a vertebral bone ss esicis (OLOIZ
Width of a costal bone -022
Thickness of same -005
Interval between two raised lines ; .007

Plate 86, fig. 4, is reproduced from Cope’s work of 1877, cited above. The figs. w and x
represent the outer and the inner surfaces of the proximal end of a costal. Figs. y and z show
middle parts of costals. It 1s greatly to be desired that far better specimens of this and other
Wasatch species of turtles, so often based on fragmentary specimens, shall soon be found.

PLASTOMENID~&. 4

~
w

Plastomenus corrugatus Cope.
Plate 86, fig. 5.

Plastomenus corrugatus, Core, Syst. Cat. Vert. Eocene New Mexico, 1875, p- 35; Append. LL of Wheeler’s
Report to Chief of Engineers, 1875, p. 1016 (of separata, p. 96); Wheeler’s Surv. W. rooth Merid.,
Iv, pt. 11, 1877, pp. 48, 50, plate xxv, figs. 20-26; Vert. Tert. Form. West, 1884, p. 123.—Hay,
Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452.

Professor Cope stated in his monograph on the fossil vertebrates of New Mexico that he
had remains of 6 individuals which he referred provisionally to the present species. Of these
he figured fragments of 2. One of these two was represented by only a portion of the left
hypoplastron; and this was regarded as the type of the species. It is represented by his fig. 20,
which is here reproduced (plate 86, fig. 5). The other bones figured were portions of costals
except the one represented by his figure 25. The present writer is not aware where these hgured
specimens now are. They were collected in the Wasatch beds of New Mexico. The exact
locality was not designated, but it was doubtless from the Gallinas River region.

Of the type bone, the hypoplastral, Cope makes the following statements:

This bone is ornamented with sharp, raised, narrow ridges, which are straight or vermiculate, and
which inosculate but little. The broken base of the bridge is particularly stout, and the thickening
continues within the inguinal border to the postabdominal extremity. The inguinal edge is thinner, and
is incurved at the postabdominal gomphosis.

MEASUREMENTS.

Meter.
Thickness of the hyposternal at middle. . 0.007
Thickness of hyposternal at bridge. . 009
Seven ridges measure... . ; -O10

Judging from Cope’s figures of the costal bones, they presented a very different style of
ornamentation. Here we find what Cope has called a honeycombed structure. There were
apparently abruptly sunken pits, about 5 in a line 10 mm. long; while the intervening ridges
were about as wide as the pits themselves. Professor Cope presented no measurements of these
bones, so that we do not know their thickness. Altho they are so different in their style of
ornamentation from the type plastral bone they appear to be connected with it by the bone
represented by Cope’s fig. 25. Cope regarded this bone as a part of the left hyoplastron; but
a comparison of it with the plastron of Plastomenus thomas: makes it more probably the outer
end of the right hyoplastron. The figure ought to be inverted.

Plastomenus communis Cope.
Plate 86, figs. 6-8.

Plastomenus communts, Cope, Syst. Cat. Vert. Eocene, New Mexico, 1875, p. 35; Append. Li of Wheeler’s

Report to Chief of Engineers, 1875, p. 1016 (of separata, p. 96); Wheeler’s Surv. West tooth Merid.,

Iv, pt. 11, 1877, pp. 48, 50, plate xxv, figs. 1-3, ?4; Vert. Tert. Form. West. 1884, pp. 123, 126.—
tay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 452-

That specimen which 1s represented by fig. 1, plate xxv, of Cope’s memoir publisht in the
fourth volume of the Wheeler Survey, must be regarded as the type of the present species.
This type belongs to the U. S. National Museum and bears the catalog number 1132. It con-
sists of the distal ends of a number of costal plates and a portion of the left hyoplastron. These
were collected by Professor Cope in Wasatch beds in New Mexico, doubtless in the region
of the Gallinas River.

While the known remains of this turtle indicate a distinct species and one which may be
recognized when other considerable parts shall have been discovered, they do not enable us
to obtain an accurate idea of the animal. It must have attained a considerable size, since one
of the costals had a width of 44 mm. It had a thick and coarsely sculptured shell (plate 86,
figs. 6,7). There were no rib-ends protruding beyond the borders of the carapace. The form
of the fragment of the hyoplastron (plate 86, fig. 8) present indicates pretty certainly that the
species belongs to the genus Plastomenus.

474 FOSSIL TURTLES OF NORTH AMERICA.

The free borders of the costals are thick and obtuse, resembling the edge of one’s little
finger (plate 86, fig. 64). That costal which forms the lower part of fig. 6 here presented has a
thickness of 12 mm. The upper surface of the costals is ornamented with pits, of which there
are about 4 in a line 10 mm. long, being somewhat larger than stated by Cope. On what are
evidently posterior costals there are conspicuous welts, ebiche at the distal ends of the costals,
run parallel with the sutural borders. The pits are in rows parallel with the free borders of
the costals.

The portion of the hypoplastron belonging to the type agrees closely in form with that of
P. thomasi. Cope’s figure is reproduced on page 86, fig. 8. The lower border joined the hypo-
plastron. The lower half of the border on the left joined the hyoplastron of the opposite side.
The oblique border above this formed a part of the boundary of a fontanel. The lower sur-
face, as seen, was sculptured with pits, arranged in rows parallel with the mesial border. These
pits are smaller than those of the carapace, there being about 6 or 7 of them in a 10 mm. line.

In his description given in the Wheeler Survey Cope includes some fragments in this
species that he afterwards (Vert. Tert. Form. West, p. 125) referred to P. molopinus, the type
of which came from the Bridger beds. While these specimens quite certainly do not belong
to P. communis, it is doubtful if they belong to P. molopinus. It is to be noted that in the
text of the Wheeler Survey Cope refers to these specimens as representing a “‘var. ii,” but in
the explanation of his plate xxv he speaks of them as “‘var. 1.”

Plastomenus thomasi Cope.
Text-figs. 633-637.

Trionyx thomasi, Cope, 1872, Proc. Amer. Philos. Soc., xu, p. 462.

Plastomenus thomas, Cope, Proc. Acad. Nat. Sci. Phila. 1873, p. 278 (name only); 6th Ann. Report
U.S. Geol. Surv. Terrs., 1872 (1873), p. 618; Ann. Report Chief Engineers, 1875, Append. LL, p.
1016 (of reprint, p. ee ene and Cat. Foss. Vert. N. A., 1902, p. 453.

Plastomenus multifoveatus, Cope, 1873, Proc. Acad. Nat. Sci. Phila. p. 278 (name only); 6th Ann.
Report U.S. Geol. Surv. Tesrs., 1872 (1873), p. 619; Vert. Tert. Form. West, 1884, pp. 123, 125,
plate xviii, figs. 2-8.

The original description of the present species was extremely brief; and we could only
with difficulty know that it applied to the species, had not Professor Cope quoted it in subse-
quent and more detailed descriptions. Only portions of the carapace were mentioned. What
appears to be the next reference to the species, that in the Proceedings of the Philadelphia
Academy, was accompanied by no characters to distinguish it from related species. With it
was mentioned another species called P. multifoveatus. It was in this communication that the
genus Plastomenus was proposed, the characters of which were based on both carapace and
plastron. In Hayden’s Report for 1872, as cited above, there appear descriptions of both P.
thomas: and P. multifoveatus. With the former were briefly described some plastral bones.
In the fourth volume of the Wheeler Survey, Professor Cope described New Mexican specimens
which he regarded as belonging to P. multifoveatus. To this species he now refers the
specimens which he had originally called P. thomasi, while the latter name is restricted to
plastral bones which he states were more like those of Trionyx. In the Vertebrata of the
Tertiary Formation of the West, 1884, he writes as follows under P. multijoveatus:

When I stated there [Report Geol. Surv. 1872] that P. thomasi is the type of the genus Plastomenus
I referred to these specimens; it is therefore to be observed that the type of the genus is really the P.
multifoveatus. The true P. thomast was founded on sternal bones perhaps of a Sniail species of Trion yx.

Regarding this statement the following may be said: (1) No plastral bones were men-
tioned in the original description of P. Nomare (2) The description of P. thomas: found in
the Hayden Survey report of 1872 was taken bodily into the description of 1884. (3) We
know of no description of the plastral bones on which Cope says that P. thomas: was founded.
In view of these facts we must say that whatever Cope had in mind, he did not, according to
the recognized rules of nomenclature, attach the name P. thomasi to the Trionyx-like plastral
bones, but did attach it to those specimens which he afterward called P. multifoveatus. The
latter name therefore becomes a synonym of the former.

PLASTOMENID&. 475

The bones of the plastron which Professor Cope was disposed to take as the type of P.
thomasi are now in the American Museum of Natural History, and are described under
Platypeltis sertalts.

Those specimens which Professor Cope figured in his great work of 1884 under the name
P. multifoveatus must be regarded as the type of the present species. Of these specimens
that which furnisht fig. 6 of plate xviii is
now in the American Museum of Natural
History. The others are in the U. S.
National Museum at Washington. Of
these figures, 2 and 5 represent the distal
ends of 2 costals; fig. 3, the outer end of
the right hyoplastron; fig. 4 is the left
hypoplastron; and hg. 7, the right hypo-
plastron. Figs. 2 and 5 seem to indicate
that the sculpture is irregular, but in the
text Cope states that the ribs intervening
between the pits tend to connect into ridges
running diagonally across the costal bones.
These specimens were obtained on Cotton-
wood Creek.

The American Museum party of 1903
operating in the Badlands of the Bridger
Basin discovered a nearly complete shell
which is identified as belonging to Cope’s
P. thomas:. It was found at Grizzly
Buttes, and the catalog number of the
specimen is 6018. The carapace lacks only
unimportant fragments. From the plas-
tron there are missing the entoplastron, the epiplastra, the median end of the nght hyo-
plastron, and the right xiphiplastron.

The carapace (fig. 631) has a length of 218 mm. and a breadth of 210 mm. The upper
surface was evidently moderately convex during life. The nuchal bone extends from side to
side a distance of 97 mm. and from front to back 30 mm. There are present a preneural and

six neurals. It is probable that there was a small seventh
neural in a notch between the costals of the seventh pair.

Fic. 631.—Plastomenus thomast. Carapace. .

No. 6018 A. M. N. H.

Element. Length. | Width. The table shows the dimensions of these elements.

The costals of the eighth pair meet along the midline
Preneural.... 15 17 48 mm. and each measures 48 mm. along the free border.
Neural 1 my, s) The outer ends of the ribs extend but little beyond the bor-
Neural 2 20 14 ‘ i 5
Neural 9). a 1 der of the disk. The outer ends of the costals are about 7
Neural 4.. 18 14 mm. thick; and between the upper and lower layers of the
Neural 5-4 175 na bone there is a channel running around most of the border.
Neural 6.. 14 8 5

On each side of the upper surface there are seen about

8 low and broad welts; 2 or 3 of these extend on the nuchal.

The nuchal and the outer ends of the costals are ornamented with shallow pits. These are

mostly arranged in rows parallel with the border of the disk. A line 10 mm. long extends

across 4, sometimes 5 pits. On the neurals and the proximal ends of the costals the pits are
nearly obsolete.

The form of the plastron and the proportions of its different parts may be seen in fig. 632.
The width of the plastron between the ends of the hyohypoplastral suture is 210 mm.; the
length along the midline, excluding the missing elements, is 135 mm. The bones of the
opposite sides are joined by jagged sutures. The hyohypoplastral suture of each side makes
an angle of about 75° with the median longitudinal suture. The greatest width of the hyo-
plastron is 47 mm.; the width of the midline, 25 mm. The width of the hypoplastron at the
midline is 49 mm.; of the xiphiplastron, 60 mm. The width of the hinder lobe, at its base, is

100 mm.,; its length is 85 mm. The thickness of the hyoplastron at the midline is 5 mm.;

470 FOSSIL TURTLES OF NORTH AMERICA.

of the hyoplastron, 7 mm.; of the xiphiplastron, 5 mm. In front of the hyoplastra there was
probably a small fontanel, indicated by a notch in each bone. The notch farther from the
midline received one end of the entoplastron. The lower surface of all the plastral bones is
covered with shallow pits. Most of these are in rows parallel with the free borders of the
plastron. There are four, sometimes five, sometimes only three pits in a line 10 mm. long.

Mr. Walter Granger, in 1903, discovered at Grizzly Buttes the skull and the outer end of
the left hypoplastron of a trionychid which proves to belong to the present species. Judging
from the portion of hypoplastron, the individual was about half-grown. The specific identity
of this bone with that of the larger individuals is furnisht by a hypoplastron belonging to the
Cope collection, No. 1030 of the American Museum of Natural History. Of the skull (figs.
633-635) practically all portions are represented; but the palatal region has not been cleaned
of the matrix. The premaxillary bone is wanting and the occipital condyle is broken away,
but the length of the skull from the extremity of the one of these bones to the other has been
close to 50 mm. From the snout to the end of the supraoccipital process has been 57 mm.
The head is narrow, 24.5 mm. wide, slightly less than one-half the length to the occipital
condyle. The snout is long and narrow. The upper surface of the skull forms a regular

Fics. 632-635.—Plastomenus thomasi. Plastron and skull.
3 aD

632. Plastron. 4. No. 6018 A. M.N.H. 633. Skull, upper view. X1. No. 6015 A. M. N. H.

634. Skull, side view. 1. No. 6015 A.M.N.H. 635. Lower jaw, from below. 1. No. 6015 A.M.N.H.
curve from the snout to the end of the supraoccipital process. The orbit has an antero-posterior
diameter of 10 mm., and the space between this and the nostril was the same. No postfrontal
bone has been discerned. The postorbital process of the jugal reaches the parietal and this
bone enters into the formation of the orbit, a very unusual arrangement. In Platypeltis
spinifera the postfrontal bone is small, but it excludes the parietal from the orbit. In Plasto-
menus thomas: the interorbital space has a width of 4 mm. The squamosal process was
formed as in Platypeltis. The lower jaw (fig. 635) is narrowed in front; the symphysis is 14
mm. long.

The respects in which this species differs from P. visendus, referred in a former publication
to P. thomas, will be given under P. visendus.

Plastomenus visendus sp. nov.
Plate 87, figs. 1, 2; text-figs, 636, 637.
Plastomenus thomast1, Hay, Amer. Geologist, xxxv, 1906, p. 334, figure.
Among the materials included in the Cope collection now in the American Museum of
Natural History there was found a cigar-box of fragments which had been collected in the

Bridger deposits of the Rattlesnake Hills, Wyoming, in 1895, by Mr. Stanley Stuart. On

being fitted together these fragments furnisht a nearly complete carapace and plastron of a

PLASTOMENID. 47

species of Plastomenus. It was originally supposed that this was Cope’s P. thomasi, but the
fortunate discovery of a specimen of the latter at Grizzly Buttes, near the type locality, shows

that the specimen from the Rattlesnake Hills belongs to a distinct and hitherto undescribed
species. The catalog number of the specimen is 1895.

In form this species is broadly oval, with the broadest portion somewhat in front of the
middle of the carapace. The latter appears to have been only moderately archt. The total
length of the carapace (plate 87, fig. 1; text-fg. 636) is 207 mm. along the midline. The
greatest width is 204 mm. ‘There were no fontanels in the carapace, and the ribs extended
bey ond the disk probably nowhere more than about 12 mm. There is no evidence that there
were any peripheral bones. The nuchal is firmly united with the first pair of costals. Only a
fragment of the preneural is preserved. There are present remains of 4 neurals. Of the first
there is only a fragment. The fifth and sixth neurals are missing. The costals of the seventh
and eighth pairs meet in the midline for their whole breadth; ine corresponding neurals

——

\ a a =. ~ =
| a eee pene
\
oe es Be i ae (a
u \ }
|
\
(gas —
af ee eee
Fics. 636 AND 637.—Plastomenus
vise re «4.
636. Carapace. 637. Plastron.

were not developt. The nuchal has a lateral extent of go mm.; and a fore-and-aft extent of
20 mm. Its outer ends neither overlap nor underlap the anterior border of the first costals.
These costals are somewhat narrower at their distal ends than at the proximal. The other
costals, except the seventh, are wider at the outer ends than proximally. The seventh costals
are much wider along the midline than any of the others, and form a large part of the rear of
the shell. They extend along the midline a distance of 50 mm., and laterally from the midline
a distance of 75 mm. The edges of the carapace are rounded or cut off rather abruptly. The
thickness of the costals at the free edges is about § mm. The only neural which is complete
is the third. It has a length of 18 mm. and a width of 12 mm. posteriorly.

The ornamentation consists of a number of longitudinal welts and of numerous pits. Of
the welts there are about 10 on each side. These resemble a series of waves, those near the
midline being somewhat nearer together than those near the borders of the carapace. On the
hindermost costals the welts are sharper and somewhat broken up into elongated nodules.
On the nuchal and costals of the first pair the welts are obsolete. The pits are rather shallow
and are separated by ridges which are rounded or flat on their summits. There are 5 or 6 of
the pits in a line 10 mm. long. They are less distinct on the neurals and the proximal ends of
the costals. On the outer halves of most of the costals the pits are arranged to a great extent
in rows, parallel with the axis of the animal or with the adjacent free border of the carapace.

Of the plastron (plate 87, fig. 2; text- fig. 637) the entoplastron, both epiplastra, and a
small portion of the left hy poplastron are missing. The parts present are shown on the plate

478 FOSSIL TURTLES OF NORTH AMERICA.

cited. As will be observed, there was a median fontanel partly inclosed by the hyoplastrals.
Behind this the elements of the plastron met along the midline to the hinder extremity of the
xiphiplastrals, just asin Chrysemys. While the hypoplastra j join the xiphiplastra by digitations
near the outer borders of these bones; these digitations are more feeble than in most trionychids.
The digitations reaching from one xiphiplastron to the other are hardly discernible. At the
outer ends of the hyoplastron and of the hypoplastron the space between the outwardly pro-
jecting processes is more nearly filled up than usual in trionychids. Everywhere the distinction
between the bone of the ‘‘callosities” and that forming the framework of the plastron is less
obvious than in ordinary trionychids.

The length of the plastron, from the line joining the antero-interior angles of the hyoplastra
to the hinder border of the xiphiplastra, is 133 mm. Of this distance the union of the hyo-
plastra occupies about 10 mm., that of the hypoplastra 45 mm., that of the xiphiplastra g2 mm.
The greatest width of the hyoplastron is 33 mm. From the extremity of one postero- external
process of the hypoplastron to the other is 210 mm. ‘The width of the posterior lobe of the
plastron at its base is 108 mm. The width of the bridge is 48 mm., of which the hyoplastron
occupies 33 mm.

On the plastron there are no welts, such as appear on the carapace. The pits are not to be
distinguisht from those of the upper part of the shell. They are largest and deepest on the
outer end of each hypoplastron. They are often arranged in rows which are parallel with the
nearest border of the bone. These rows of pits are most conspicuous on the hyoplastron.

This species differs from P. thomas: in several particulars. Both the nuchal and the hyo-
plastron have the fore-and-aft width considerably less than in P. thomast. The hinder border
of the bridge portion of the hy poplastron makes a larger angle with the midline than in P.
thomas, aad the pits of the median portions of the bones of the plastron are larger. Espe-
cially, the costals of the eighth pair extend farther along the hinder border of the carapace than
they do in P. thomasz. The front of the carapace of the latter appears to be more pointed than
that of the present species.

Plastomenus tantillus sp. nov.
Figs. 638, 639.

The present specific name is applied to a specimen which was found by the writer in the
Bridger beds, near the mouth of Cottonwood Creek, Wyoming, in the year 1903. The level
is that designated as B. The individual is a small one, with in and delicate bones, and it was
probably a young animal. It has been greatly flattened by pressure, and to has 4 is due the
spreading apart Of some of the costals at thelr distal ends. There are present nearly the com-
plete carapace and the greater portion of the plastron. The specimen bears the American
Museum’s catalog number 5980.

The outline oF the carapace (fig. 638) is rather elongated. There was probably a slight
excavation in the anterior border of the nuchal. The hinder border is rounded. The length
of the carapace is 105 mm.; the width, excluding the extension of the free ends of the ribs, is
gomm. The rib-ends projected beyond the disk an undetermined distance. The nuchal has
a lateral extent of 46 mm.; a fore-and-aft extent of 13 mm. There is a wide band in front and
at the ends which is devoid of the enameled and sculptured band. This bone was quite cer-
tainly in contact with a preneural, but the latter is not preserved. There are seven neurals,
but the hindermost one is very small, having a length of only 2 mm. ‘The other neurals are
comparatively broad. Most of them have the usual hexagonal form seen in the Trionychoidea;
but the first is 4-sided. The third has a length of a hele more than 10 mm., and a width of
gmm. Both in front of and behind the third, the others are slightly smaller.

There are 8 pairs of costals. They are thin, the bone having a thickness of only 1.5 mm.
at the sutural margins and but little more than 2 mm. where thickest. The rib of each costal
occupies about one-half of the whole width of the plate. The first costal has a width of 17 mm.
Those of the seventh pair join in the midline. Those of the eighth pair join for their whole
length along the midline, a distance of 16 mm.

The ornamentation of the carapace consists of narrow longitudinal welts, shallow pits,
and puncte. There are 5 or 6 low welts on each side of the carapace. The pits are distinct
everywhere, except on the neurals and the proximal ends of most of the costals, where they are
replaced by the puncte. Of the pits there are usually 8 in a line 10 mm. long.

PLASTOMENID&. 479

The plastron (fig. 639) resembles in general that of P. thomas:, but the bones have not
joined so closely along the midline, a condition indicative of youth. The bones average about
2mm. in thickness. At the inguinal notch the hypoplastron is 4 mm. thick. On a line
joining the axillary and inguinal notches, the hypoplastron is nearly as wide as the hyoplas-
tron; but this is quite certainly a feature due to immaturity. The same difference may be
noted between the young and the adult of Platypeltis spinifera. :

The plastral bones are covered with a network of ridges inclosing shallow pits, except on
the processes. The pits are like those of the carapace in size and distance apart. They are,
to a great extent, arranged in rows parallel with the nearest border of the bone. This is most
evident on the xiphiplastra.

This individual differs in various respects from the specimens which are referred to P.
thomasi; but many of these differences may be due to the immature condition of the animal.

So

TLL p =

Fics. 638 anp 639.—Plastomenus tantillus. Carapace and plastron of type. > 3.

638. Carapace. c.p.1, c.p.8, first and eighth costals; 2.1, ”. 6, first and
sixth neurals; nu. p., nuchal plate; pre, preneural.

639. Plastron. hyo, hyoplastron; hypo, hypoplastron; x7ph, xiphiplastron.
The carapace would probably become somewhat broader with age, as the space between the
free ends of the ribs became filled up. The anterior costals are relatively broader, fore and
aft, than in P. thomas:. The eighth costals meet along the midline a distance which is con-
tained in the entire length of the carapace 6.5 times; whereas, in the adult specimens of P.
thomas1, the length of their union is contained in the entire length only 4.5 times. In the
latter species the hinder border is somewhat excavated; in P. tantillus it is convex. The
sculpture of P. thomas: is considerably coarser than that of the species here described; and
it is believed by the writer that the coarseness of the sculpture of Trionychoidea changes
little, if at all, with increase in size of the individual.

Plastomenus cedemius Cope.

Figs. 640, 641.

Anostira edemia, Core, Palxont. Bull. No. 1, July 29, 1872, p. 461; Proc. Amer. Philos. Soc. x11, 1873,
p- 461.

Plastomenus edemius, Cope, 6th Ann. Rept. U.S. Geol. Surv. Terrs., 1873, p. 619; Proc. Acad. Nat.
Sci. Phila. 1873, p. 279; Wheeler’s Surv. West. tooth Merid., tv, 1877, p. 48; Vert. Tert. Form.
West, 1884, pp. 123, 126, plate xviii, figs. 15-17.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902,
p- 453; Amer. Geologist, Xxxv, 1905, p. 334. :

The type specimens of this species, figured by Cope as cited above, are now a part of the
Cope collection in the American Museum of Natural History. With these are other specimens
which were collected by Cope, but they are fragmentary and throw little light on the structure

480 FOSSIL TURTLES OF NORTH AMERICA

of the species. Some of the specimens mentioned by that author are either not present or have
not been recognized. They had all been collected in the Bridger beds of Wyoming. The type
came from Cottonwood Creek and therefore from level B, and has the American Museum’s
number 3937,

In the year 1903 the American Museum of Natural History sent a party into the Eocene
Badlands in the region of Fort Bridger, Wyoming. Among the materials collected by this
party 1s a nearly complete carapace and a fragmentary plastron, which are believed to belong to
the above species. These parts are popresented by figs. 640 and 641. The specimen bears the
catalog number 5978.

In form the carapace is oval, or elliptical, narrowed in front, rounded behind. It is con-
siderably archt, the midline rising to a height of 73 mm. above the borders. The length is
310 mm.; the width, 270 mm. The carapace (fig. 640) consists of a nuchal, 8 pairs of costals,
a preneural, and 6 neurals. The nuchal has a length of 145 mm. and a fore-and-aft width of

———_

X

hypo 641.

a N
|
|

Se se
Fics. 640 aND 641.—Plastomenus @demius. Carapace and plastron.

Xt. No. 5978 A. M. N. H.

640. Carapace. 641. Plastron.

38 mm. along the midline. Its hinder border is somewhat excavated for the preneural. The
costals widen toward their distal ends. The free border of each is beveled. The free ends of
the ribs are very short. The thickness of the costals is about 5 mm. Those of the sixth pair
inclose between their proximal ends the sixth neural; but behind this they join in the midline.
The costals of the seventh and eighth pairs also meet in the midline, the former for a distance
of 20 mm., the latter for a distance of 65 mm.

The preneural is pentagonal, 24 mm. long, and of about the same width. The first neural
is pentagonal, 25 mm. long and 19 mm. wide. The right postero-lateral side is very short, and
articulates with the second right costal. The third neural is four-sided, 34mm. long and 16mm.
wide. The next 3 neurals are hexagonal, with the narrow end forward. The fifth is 13 mm.
wide. The last neural is small, 15 mm. long and 6 mm. wide.

The sculpture of the surface consists of longitudinal ridges, or welts, and shallow pits.
Neither the welts nor the pits are conspicuous. The welts are obsolete on the anterior half of
the carapace, most distinct posteriorly. Running longitudinally as they do, they cross the cos-
tals of the middle of the carapace at right angles. Posteriorly they cross the costals obliquely.
A close examination of the welts shows that they resemble those of the type of the species. On
the last costal they run in the same direction and become resolved into low tubercles, but these
are not so swollen as in the type.

PLASTOMENID&. 481

The pits are shallow and in many portions of the carapace, especially near the midline and
on the rear, they are obsolete. Many of them form what Cope has designated puncte. They
cover the nuchal, the outer halves of the anterior costals, and distal thirds of hinder costals.

A considerable portion of the plastron (fig. 641) is preserved, but it is fragmentary and,
in many cases, there is contact between the fragments present. It is believed, however,
that the restoration presented by fig. 641 is not far from correct. The specimen has furnisht
the entoplastron, a part not hitherto known in the genus.

The length of the plastron, from the front of the entoplastron to the hinder end of the
xiphiplastrals, is about 245 mm.; the width about 275 mm. Evidently there were no fontanels
in the midline, except a short and wide one just behind the entoplastron. The latter bone is
more like that of Cyclanorbis senegalensis, as figured by Siebenrock (Sitzber. Akad. Wissensch.
Wien, xct, 1902, p. 34), than like that of any other living species. The lateral branches of the
bone made an obtuse angle with each other. The original bones are covered with a thick
callosity and this has filled up the angle between them. The bone measures 38 mm. on the
midline, and is from 6 mm. to 8 mm. thick.

The hyoplastra meet along the midline a distance of 50 mm.; the hypoplastra, a distance
of about 75 mm. The hinder sutural border of the hypoplastron is not present, and the xiphi-
plastron ought possibly to have been removed somewhat further backward, but certainly not
much further. The hyoplastra were flat for a distance of about 60 mm. on each side of the
midline; then they have sloped upward and outward. Where the slope begins, the bone is
about 12 mm. thick. The outer ends are considerably thinner. The outer end of the hypo-
plastron is 13 mm. thick, and terminates in 2 processes. The inguinal notch was abrupt.

The hinder portion of the hypoplastron which is shown in the figure preserves the sutural
border which joined the bone of the opposite side. It shows therefore the width of that part of
the hinder lobe. This was close to 125 mm. The hypoplastron had a thickness of about 12 mm.
at the inner border, but thinned toward the free border.

The median and anterior sutural borders of the xiphiplastron have not been preserved,
but the bone, both mesially and anteriorly, evidently approaches these sutures closely. The
outer, or free, border of the hinder lobe was quite certainly concave at the hypoxiphiplastral
suture and convex both in front and behind it. The hinder half of the xiphiplastron has a
thickness near the mesial border of 6 mm.; near the free border, 4 mm. The hinder border of
the lobe was probably slightly excavated.

The whole lower surface of the plastron, except possibly the epiplastra, which are not
known, is sculptured into a network of ridges, which inclose pits of varying sizes and depths.
On the entoplastron the pits are irregularly arranged and shallow, and there are 5 or 6 of them
in a line 10 mm. long. The median half of the hyoplastron is similarly ornamented, altho
toward the suture with the hypoplastron the pits become obsolete. The outer extremity of
the hypoplastron is furnisht with large pits, three or four in a line of 1omm. That portion of
this bone which enters into the hinder lobe has the pits arranged in regular rows which run
parallel with the free border of the lobe. Four rows of pits occupy a distance of 1omm. The
xiphiplastra are similarly ornamented, but the pits become somewhat smaller posteriorly and
the rows less regular. This specimen was collected in the western portion of Grizzly Buttes.
Cope states that two of his specimens came from Cottonwood Creek.

Plastomenus molopinus Cope.
Plate 85, fig. 3; text-fig. 642.

Trionyx, Leipy, Contrib. Ext. Fauna West. Terrs., 1873, p. 180, plate xvi, figs. 1, 2.

Anostira molopinus, Corr, Paleont. Bull. No. 1, July 29, 1873, p. 4615 Proc. Amer. Philos. Soc., X11,
1873, p. 461.

Plastomenus molopinus, Cope, 6th Ann. Rept. U. S. Geol. Surv. Terrs., 1873, p. 6 20; Proc. Acad. Nat.
Sci. Phila. 1873, p. 279; Vert. Tert. Form. West, 1884, pp. 123, 125, plate xviil, fips O—14.—
Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p- 452-

Plastomenus communis var. ii, Cope, Wheeler’s Surv. W. tooth Merid., 1877, p- 59, pl. xxv, figs. 5, 6.
Professor Cope stated that he possest remains of 8 individuals of this species from the

Bridger beds of Wyoming. The specimens figured by him in his Vertebrata of the Tertiary

Formations of the West belonged to one individual, and consist wholly of fragmentary costal

plates. They are now in the American Museum of Natural History and have the number 6072.

3!

482 FOSSIL TURTLES OF NORTH AMERICA.

Cope did not clearly distinguish this species from P. edemius. One last costal is indeed
mentioned as being crost by longitudinal ridges; and he states that if these had been broken
up into tubercles Ke would have referred the specimen to P. wdemuus.

In the collection of turtles secured by the American Museum expedition of 1903 there are
2 specimens which the writer refers to P. molopinus. These were obtained at Grizzly Buttes,
from the level known as B. One of these, No. 5941, presents a practically complete carapace
and a few fragments of the plastron; the other, No. 5945, consists of a portion of the carapace
and some parts of the plastron. These remains show great resemblances to P. edemius, and
it is possible that they should be referred there, and that P. molopinus is not different from
the former species. There is, however, one difference between the two forms which appears
to be constant. This is found in the ornamentation of the outer surfaces. Little if any differ-
ence is to be seen in the character of the welts, but the pits, or puncte, of P. molopinus are
smaller and closer together than they are in P. wdemius. In the latter there are usually only
3 or 4 pits in a space of 10 mm.; while in P. molopinus there are quite constantly 6 or 7,

occasionally but 5. To the eye, the sculpture of the
latter has a much finer appearance. In the case of both
cee species, the longitudinal welts are broken up, on the last
. costals, into elongated tubercles. It is also to be noted
S that the pits and puncte of P. molopinus are more gen-
erally distributed over the carapace than they are in
(ey \ PR edemius.
_| In P. edemius the neurals, the proximal ends of
4 most of the costals, and the whole of the hindermost cos-
tals, are smooth or nearly so, except where varied by
> ine = the presence of welts. _
ne The sculpture on No. 5941 is not very distinct, a
—/ fact that is due principally to the dirty color of the speci-
aa | men. No. 5945 is of a clear sage-green and has been
| ; weathered free from all matrix. It shows the welts and
— the puncte with great distinctness.
A No. 5941 (plate 85, fig. 3; text-fig. 642) has a length
a of 200 mm. and a width of 180 mm. It resembles closely
| eA the specimen, No. 5978, which has been described here
a er oe as P. wdemius. It was, in life, evidently quite convex.
It differs from P. wdemius, as represented by No. 597
in having the costals of the sixth pair wholly separated
by the sixth neural. No. 5945 differs from No. 5978 in
the same way; but it differs from No. 5941 in having
a minute seventh neural. This neural is regarded as having no specific value. No. 5945
further differs from No. 5941 in the somewhat broader neurals, and in having the free
borders of the costals less abruptly beveled.

Of both specimens, No. 5941 and No. 5945, the mesial end of the hyoplastron is present.
It differs from the same region in P. edemius in having a notch in the front border, mesiad
of the process against which the outer end of the entoplastron rests; but whether or not this
might appear with greater age is uncertain. The distal end of the hypoplastron is present in
No. 5945. It differs somewhat from that of P. edemius, but it is impossible to say how con-
stant this difference is likely to be.

The sculpture of the plastron differs from that of the plastron of P. @demrus in consisting
ot smaller and more closely placed pits and puncte. Of course, in making the comparison
corresponding regions must be compared.

Both the specimens here referred to P. molopinus were secured in the Bridger beds of the
western end of Grizzly Buttes. Cope figures specimens from the Wasatch of New Mexico
under the name P. communis. These are indicated in the text (Wheeler Surv., Iv, p. 50) as
‘var. i,” but in the explanation of plate xxv as “‘var. i.” We must be uncertain about this
identification until additional materials of the supposed molopinus have been secured in the
Wasatch beds.

Fic. 642. —Plastomenus molopinus.

Carapace. X 4. No.5941 A.M.N.H.

——

TRIONYCHIDA. 483

Family TRIONYCHIDZ.

Trionychoidea having the carapace devoid of peripheral bones, except in the case of
Trionyx (Emyda Gray), in which the few nodules may be of secondary origin. Epiplastra
separated from the hyoplastra by lateral prolongations of the slender, archt or V-shaped ento-
plastron. More or less extensive fontanels between the hyoplastra, hypoplastra, and xiphi-
plastra of the two sides. Pelvis not suturally joined to either the carapace or the plastron.
So far as known, no epidermal scutes. Only 3 digits with claws.

The Trionychidz constitute a family of tortoises remarkable on account of their structure,
their numbers, their geographical distribution, and their geological history. The oldest forms
at present known to us come from the Upper Cretaceous of New Jersey, W yoming, Montana,
and Alberta, British America. It is probably not now possible to determine w hich deposits
are the older, the lower marl beds of New Jersey, which furnish the little known Amyda prisca
and 4.? halophala, or the Judith River beds, from which we obtain As pideretes ‘coalescens,
A, foveatus, and A. splendidus. So far as the shells are concerned, we find in the Judith River
forms only specific differences when compared with living species. 4s prderetes beecheri, of the
Laramie and probably too of the Judith River beds, filienighes practically all portions of the
skeleton, except the skull; and these agree in all essential respects with the skeletons of living
trionychids. So far as the writer is aware, the oldest known trionychid skull is that of Con-
choc helys admurabilis Hay of the Puerco deposits. This presents some differences when
compared with modern trionychids. The next oldest skull, that of Aspideretes singularis, of the
Torrejon, differs little from that of Platypeltus ferox, now living in Florida.

Trionychids are at present found in Asia, Africa, and North America. Asia furnishes at
least 15 species, Africa 5 species, and North America about 7.

All these data point to a very ancient origin for the Trionychida. We may expect to find
more primitive forms in fresh-water deposits “oe the Lower Cretaceous or even in those of the
Jurassic. Itis probable that these primitive forms will approach more closely the Cryptodira
than do the Plastomenide.

A'. Skull broad, with narrowed pterygoids and wide maxillary alveolar surfaces...... Conchochelys
A®. Skull unknown; carapace and plastron covered with pustular elevations. ...... Helopanoplia
AS. sa usually not so broad; pterygoid region of the palate broad:
. Plastron smooth; no ridges and pits......... Axestemys
*. Carapace and plastron Sreamented with ridges and pits.
1. Eight pairs of costal bones; a preneural present.... Re As pideretes
2. Eight pairs of costal bones; no preneural ....... WP es Poe sate ial a Amyda
3. Seven pairs of costals, or those of the eighth pair vestigial; no preneural. . Platypeltts

Genus CONCHOCHELYS Hay.

Skull broad. Masticatory surfaces broad and concave. Pterygoid region narrow. Basi-
occipital region short. Choanae behind the orbits. Posterior squamosal process apparently
much shortened.

Type: Conchochelys admirabilis Hay.

In its broadened form, its narrowed pterygoid region, and in its apparently abbreviated
posterior squamosal processes, this trionychid presents auch deviations from known genera that
the writer is led to the conclusion that it represents a genus distinct from all other hitherto
described. Until more shall have been discovered regarding the structure of the animal, the
characters given above may serve to distinguish this genus. The name Conchochelys, given
in refenenee: to the supposed nature of the food of the turtle, was first publisht in the Ballin
of the American Museum of Natural History, vol. xx1, 1905, page 335.

Conchochelys admirabilis Hay.
Plate 88, figs. 1-3.
Conchochelys admirabilis, Hay, Bull. Amer. Mus. Nat. Hist. xx1, 1905, pp- 335-338, figs. 1-3.
The skull which is here described was collected in the year 1892 by Mr. O. A. Peterson,

who accompanied Dr. J. L. Wortman, then in charge of a collecting party from the American
Museum of Natural History. It was obtained in the Puerco beds " the northern part of New

484 FOSSIL TURTLES OF NORTH AMERICA.

Mexico. The exact locality is Coal Creek Canyon, in the southeastern corner of San Juan
County. The specimen bears the catalog number 6090. The skull is quite complete, with the
exception of the absence of the lower jaw. Figures of the object as seen from above, from below
and from the right side are presented.

The skull is that of a large and evidently aged individual and no sutures are to be observed.

The premaxilla and the anterior extremities of the maxilla are missing, but the missing
parts would add little to the length of the snout. The distance from the front of the nasal bones
to the extremity of the occipital condyle is 127 mm. The breadth across the zygomatic arches
is 111 mm.; the distance from the outside of one quadrate to that of the other appears to have
been about 88 mm.; and the width across the skull at the middle of the tympanic cavities 1s
108 mm. It will be seen therefore that the roof of the tympanic cavity projects much over the
pedicels of the quadrates. Usually in living trionychids the breadth across the pedicels of the
quadrates is as great, or nearly as great, as the breadth at any other part. The hinder portion
of the skull is shortened. The extremity of the condyle is only 13 mm. behind the line joining
the quadrates. In a specimen of Platypeltis ferox 94 mm. long from the snout to the condyle,
the latter is placed at a distance af 17 mm. behind the quadrates. Relatively to other species
of the group the skull is broad, the breadth being 86 per cent. of the length. In Pelochelys
cantoris, Whose skull is relatively broad, the width of the latter is 82 per cent. of the length.
The skull of the species under description is flat, and this appears to be due in no measure
to crushing. Placed on a level surface, the skull has its crest elevated to a height of 65 mm.
The snout was blunt. The skull maintains its breadth as far forward as the line joining
the posterior borders of the orbits, where itis g8 mm.; then the outlines converge rapidly.
The interorbital space is 15 mm. wide. The orbits look outward, forward, and upward, and
are circular, with diameters of 22 mm. From the orbits the sides of the face slope downward
and outward.

The anterior nasal opening appears to have had little height, rising only 8 mm. above the
floor of the passage. Its breadth has been 20 mm. The lateral crests of the parietals converge
rapidly and meet opposite the fronts of the prootics. The postorbital arch has a width of
11mm; the zygomatic arch a width of only 8 mm. in the middle of its length. At its anterior
inferior border it starts from the hinder extremity of the cutting-edge of the maxilla,and ascend-
ing passes backward to the front of the tympanic cavity. It is far more archt than that of
living trionychids. The tympanic cavity is relatively longer than that of Platypeltis ferox, the
length being 33 mm., one-fourth the length of the skull. In ferox the length of the cavity is
about one-fhfth the length of the skull.

In contradistinction to P. ferox, the upper border of the squamosal is not rolled down-
ward, but stands out as a sharp edge. Moreover, there does not appear to have existed
that long backwardly directed process of the squamosal and paroccipital which we find so
conspicuous in the living trionychids. It is possible that this process was originally somewhat
longer than now appears; but it could have been but little longer.

The fossa inclosed by the zygomatic arch is greatly different from that of Platy peltis.
In the latter, and perhaps in all living members of the Trionychide, the fossa is longer than
broad. In this Puerco species the length is 34 mm., the width about 38 mm.

The occipital crest has been injured and is partly missing. It included a lower horizon-
tally expanded border and a thickened superior border. The latter may be, so far as preserved,
the backwardly prolonged parietals.

The upper jaws were furnisht with subacute cutting-edges. From these the palate rises
in a high vault, 26 mm. above the cutting-edges. The choane are removed far backward,
their front borders touching a perpendicular plane thru the posterior borders of the orbits.
The distance from the premaxille to these choanz was about 50 mm. There was, therefore,
an enormous crushing surface on the upper jaws, and we may conclude with safety that the
animal was accustomed to devouring a prey that was protected by hard coverings, such as
mollusks. From each choana a groove in the roof of the mouth extends backward about 30mm.

The pterygoid region is only 36 mm. wide. In the specimen of Platypeltis ferox referred
to, the pterygoid region is eight-tenths the width of the upper jaws. This region in the fossil
is very concave transversely. The articulation of the quadrate was about 20 mm. wide.

This skull is the most ancient one of the Trionychide that is at present known.

TRIONYCHID. 485

Genus HELOPANOPLIA nov.

Trionychids with hyoplastron and hypoplastron not co-ossified, and with both the carapace
and the plastron ornamented with numerous tubercles which resemble the rounded heads of
small nails. The tubercles in some places coalescing to form short ridges.

Derivation of name: #Aos, a nail used for ornament; zavord(a, full armor.

Type: Helopanoplia distincta Hay.

This genus differs from Trionyx (Emyda Gray) in having the hyoplastron free from the
hypoplastron until advanced age. In Trronyx the two bones co-ossify at a very early stage.
Doubtless better materials of the fossil species will reveal other differences.

Helopanoplia distincta sp. nov.

Plate 88, figs. 4, 5-

The only known materials which indicate the former existence of this species are a frag-
ment of one costal plate and a portion of one hypoplastron or hyoplastron. These fragments
were collected by Prof. J. B. Hatcher, while in the employ of Prof. O. C. Marsh, at that
time vertebrate paleontologist of the U. S. Geological Survey. The remains were secured in
the Laramie deposits of Lance Creek, Converse County, Wyoming, and indicate a rather
large and heavy soft-shelled tortoise. The fragment of carapace (plate 88, fig. 4) is a part of
the upper half of a costal plate. It 1s only 34 mm. long and does not extend entirely across the
plate, but apparently lacks little of doing so, since the thickening of the rib lies rather closer
to the side bearing the suture than to the other. The thickness thru the sutural border is
to mm.; thru the rib, 13.5 mm. at the proximal end of the bone, and 10.5 mm. at the distal end.

Whether the fragment of the plastron (plate 88, fig. 5) belongs to the hyoplastron or to the
hypoplastron can not be determined with certainty; it seems to belong to the latter of the left
side. The piece formed a portion of the plastron between the fore and hind legs. The bone
is thickened most at the end farthest from the midline, being there 15 mm. ‘Toward the mid-
line the thickness becomes reduced to g mm. At the free border the bone is suddenly reduced
in thickness and the edge is subacute.

The ornamentation of this species resembles much that of Trionyx granosus, called Emyda
granosa, in Boulenger’s Catalogue of Chelonians. The costal plate is thickly studded with small,
rounded tubercles which look like the heads of insect pins. Four or five of these occupy a dis-
tance of 5 mm. The distance between the tubercles is, on an average, somewhat less than the
diameters of the tubercles themselves. Perhaps half of the tubercles become connected in
twos and threes to form short and winding ridges. Similarly, but to a greater extent, the
tubercles of Trionyx granosus coalesce along the middle of the back.

On the piece of plastron the tubercles are less crowded and seldom join to form ridges.

It is believed that this style of ornamentation is so different from that of the other species
of Trionychide that a distinct genus is indicated.

Genus ASPIDERETES Hay.

Carapace with 8 pairs of costal plates; one or more of the posterior pairs in contact on the
midline. A preneural plate between the nuchal and the true first neural. Young of living
species with numerous longitudinal dorsal dermal ridges or series of tubercles.

The type of this genus is Trionyx gangeticus of Cuvier. Other living species are 4. hurum
and A. leith. Trionyx melitensis described by Dr. Lydekker from the Miocene of Malta must
be referred to the same genus.

That which distinguishes this genus from dmyda is the presence of a preneural bone. The
writer regards this as a primitive character which has been lost by the other genera of Trio-
nychide. This bone is present in the Plastomenidz also and in some of the Baénide.

It is a noteworthy fact that no trionychid from the Cretaceous deposits is known to be
without this bone. Two Upper Cretaceous species are arranged under Amyda, viz., 4.
prisca and A. halophila, but these are based on fragments only and it is quite probable that
better materials would show the presence of the preneural.

486 FOSSIL TURTLES OF NORTH AMERICA.

Key To THE SPECIES OF ASPIDERETES.

A‘, Judith River and Laramie species:
1. Shell of moderate size, broad; middle region of carapace with round pits, somewhat
scattered; distal ends of costals crossed by furrows and ridges; plastron with
twisted ridges ....... laa ae eae OIE At a aN foveatus
. Shell large, Begader than long; pits numerous everywhere, in rows across distal ends

so

of costals; nuchal excavated in front................. .... coalescens
Shell large, considerably broader than long; sculpture (ike that of aE scens,
but less in rows across outer ends of costals; nuchal convex in front, straight

behind. pees Pare jae ete as Ae ae rate eR AE a Met splendidus
4. Shell nearly 2 as : broad as long, sculpture of carapace as in eo ae SceNS; nuchal straight
or convex in front, shorter from side to side than splendidus; sculpture of plastron

Ww

finemthaneinucoalescens,. sase ae ee ec tee ee eee eee eee beechert
5. Nuchal with thick abrupt free border; its width equal to half the distance from pre-

neural to outer end; thickness at preneural border of type 4 mm.; pits not large... fontanus
6. Nuchal with thick abrupt free border; width probably less than in 4. fontanus and

thickness greater; pits large and irregular in arrangement .................. austerus
7. Nuchal three-fifths as wide as distance from preneural to outer end; free border

beveled off; bone at preneural border 7 mm. thick, preneural as wide as nuchal. . vorax

A’. Arapahoe species:
A species not well known. Pits of costal bones shallower than in the species numbered
2, 3 and 4, and with less abrupt walls ................. a “Eee vagans
a. _ Union and Puerco species:
. Disk of carapace longer than wide; nuchal joined by its whole length to preneural
and first costals; the outer end hardly reaching the rib of the first costal; 5 to 7
pits Tay 2S Mime yas cee ecdeatar ster cq atniey cl otenabonmnyt aucun nc ene eee . Sagatus
2. As in sagatus, but the outer end of the nuchal extending: across the ap of she
first costal; 6 to 8 pits in a 20 mm. line on proximal ends of costals; only 3 or 4

on distal ends ........... F edn spp smincn este ome dinets ; .. singularts

Disk wider than long; sculpture Obscure | in town specimen, Bee. nee than in
SAR QUUS) ateie tie nseie tie RCO Pom ees art ene, Cea er nen rae nassau

4. Disk longer than ide: nich loosely joined to preneural and eastalss. fontanels
Dehn sit trea. teers oe eae teeter ae ee eee De Sens ee eae -o 2. puercensts

A‘. Bridger species:
1. Preneural doubtfully present; a fontanel on each side of its position. Pits of cara-
Pa Cen arp ctavediie ste Aeteiate ere vice cty a) tevscene cgteaen tetera ae eRe ge ae oe guttatus

2. A well- -developed preneural aad no fontanels; sculpture eomewhae coarser than in

either the preceding or the following species; second and third neurals about

half as wide as long....... a : me . * .... ellrpticus
3. A well-developt preneural and no foneanek: sculpture like that of guttatus; second

and third neurals nearly two-thirds as wide as long....... f sc Loe. grangert

Aspideretes foveatus (Leidy).

Plate 89, figs. 1, 2; text-figs. 643, 644.

Trionyx foveatus, Lerpy, Proc. Acad. Nat. Sci. Phila. vit, 1856, pp. 73, 3123 Amer. Jour. Sci., (2)
xxul, 1856, p. 120; Trans. Amer. Philos. Soc., x1, 1360, p- 148, plate xi, figs. 1-3.—Cope, Synop.
Ext. on Rept. and Aves N. A., in Trans. Amer. Philos. Soc., x1v, 1869, p: 0525 Bull. U. S. Geol.
and Geog. Surv. Terrs., 1, 1879, No. 2, p. 29; Vert. Tert. Form. West, 1875, p. 260; Bull. U.S.
Geol. and Geog. Sury. Terrs., 1877, in p- 573-—Lampg, 1902, Geol. Surv. Canada, Summary
Rept. for 1gor, p. 81, plates i, 11; Cont. Canad. Palzont, 11 (4 to), pt. 1, p. 33, plate i, figs. 1, 2,
text-hg. 1.—Hay, Bibliog. and Cat. Foss. Vert. N. A., p. 454, 1902.—Hartcuer, Bull. U.S. Geol.
Surv. No. 2575 1008, 4p: 72:

The specimens described by Dr. Leidy under the name Trionyx foveatus were collected by
Dr. F. V. Hayden partly in the Judith River beds of Montana and partly in beds supposed to
be of the same age, near Long Lake, in what is now Burleigh County, North Dakota.

Those from ale Judith Riv er basin are described as consisting of small fragments of costal
and sternal plates; and of these the proximal half of a costal plate and two , fragments of a
hypoplastron are described and figured in Leidy’s paper of 1860 on ‘The Extinct Vertebrate

TRIONYCHID. 487

Fauna from the Judith River and Great Lignite Formations of Nebraska,” publisht as cited
above. These parts, now preserved in the Academy of Natural Science at Philadelphia,
must be regarded as the types of the species. A fragment of the right last costal plate, found
near Long Lake, was identified, with some doubt, as belonging to the same species, and
furnisht fig. 3 of Leidy’s plate above cited. This specimen is now 1n the National Museum at
Washington and bears the catalog number 990.

As regards the type specimens, there seems to be no certainty that the costal plate and the
fragments of plastron were found associated. We must, however, for the present, assume
that they belong to the same species. Should future discoveries prove that two species are
involved, we shall have to take the costal plate as the type.

This costal is 22 mm. wide, 5 mm. thick at the sutural margins, and 7 mm. thick thru
the rib. The ornamentation consists of pits of varying size and shape separated by ridges

whose summits are usually flat. There
ee ce are, in general, 5 pits in a line 10 mm.
ne a long. The pits are, as stated by Leidy,
Q. . smaller at the proximal end of the costal
than further outward; but this increase
in size is due to the narrowing of the
separating walls, not to a reduction in
the number of pits in a given line. The
pits are concave, and give the impression
of having been scoopt by an engraver
in a level surface. Near the sutural mar-
gins of the costal the pits are almost
wholly wanting and the surface is level
and smooth.

The fragments of the plastron of the
type are 8 mm. thick. The lower surface
is covered with short vermiculated ridges,
some of which inosculate with the neigh-
boring ridges while others do not.
Scattered among these are small dot-like
elevations.

Mr. L. M. Lambe, of the Geological
Surwey of Canada, described, as cited in

the synonymy above, a nearly complete
apace eae eS OBERT eronvnds Ne Senate es carapace and some plastral bones which
the costal bones; pre, preneural; 7.1, 7. 6, the neurals; nu. p, :
nuchal bone. he refers to this species. These he
secured in the Belly River deposits, on
the Red Deer River, in Alberta, British America. The nuchal bone is missing from the cara-
pace. The length of the carapace (plate 89, fig. 15 text-fig. 643) as found, is 163 mm. The
width of the nuchal has been estimated by Lambe as 5 mm. but it is probable that the
width fore and aft was considerably greater. The maximum width of the carapace is 214 mm.
The rear is broadly rounded, and the upper surface is moderately
convex. There are present a preneural, 6 neurals, and 8 pairs of
costals. The genus 4 spideretes is therefore indicated.

Fic. 643.—Aspideretes foveatus. Carapace. X¥.
Figure by L. M. Lambe.

ee
Neurals. | Length. Greates

| width. > : ‘ 5

| The preneural is short, being 18 mm. wide and 12 mm. long.

The 4 anterior neurals are broader behind than in front; the
: res fifth is a parallelogram; the sixth is broad in front and pointed
, a 14 behind. The dimensions of the neurals are given in the table.
4 21 13 The eighth costals are small, almost vestigial, as in some

8 | ‘ . A :

| 5 : oA species of Platypeltis, the lateral extent of one being about 22

6 16 14 \ E 5

mm.; of the other, 20 mm. Each lies in a notch in the costal in
front of it, and they do not come into contact at the midline, the
latter condition being probably an individual peculiarity. The sculpture resembles closely that

of Leidy’s type. It is thus described by Lambe:

488 FOSSIL TURTLES OF NORTH AMERICA.

Small, shallow, rounded depressions mark the surface of the neurals and the inner ends of the costals.
In the latter, as the distance from the neurals increases, the depressions gradually grow larger and more
decided, becoming often reniform or oval, and frequently coalescing, until in the distal ends of the costals
a few more or less continuous furrows are formed parallel to the outer margins of the plates. ‘These
furrows are a conspicuous feature in the sculpture; they are not so well marked on the posterior margin
of the carapace, but are well developed near the front edges of the first costals. In the neurals and
inner halves of the costals there is a narrow, smooth strip, devoid of all sculpture, bordering the sutures.

None of the plastral bones referred by Lambe to this species were associated with the
carapace described. The author referred to states that the plastral bones belonged to individuals
of larger size than that to which the carapace belonged. A comparison of the bones with
corresponding parts of individuals belonging to Platypeltis ferox and P. spinifera shows that
the individual represented by the carapace may have been as large as the others or even larger.

In form the plastron (plate 89, fig. 2; text-fg. 644) resembled much that of the living
species just mentioned. ‘The sculpture consists of ridges and intervening furrows of varying

length and of irregular direction.

Of the ridges there are about 9

33 in a line 20 mm. long. On the

ae a: outer ends of the bones the ridges

run parallel with the long axis of

Z the animal. On the inner half,

{ the ridges are shorter, less eleva-

hyo \ ted, and irregular in their course.

, In the collection of fossil verte-

brates made in the Judith River

basin by Mr. C. H. Sternberg, in

1876, for Professor Cope, fiere

are many fragments of costal

bones which belongtothis species;

but they throw no adderall light
on it.

From the Laramie beds at Hell

Fic. 644.—Asprderetes foveatus. Right Hyoplastron and hypo- Creek, Montana, Mr. Barnum
plastron. %%. Reduced fein Lambe’s figure. Brown has brought to the Amer-
ican Museum of Natural History

fragments of a trionychid that
resemble very closely similar poemene from the Judith River basin. Three consecutive
neurals and portions of costals have the number 1017. Had they been found in Judith River
deposits they would without hesitation be referred to 4. foveatus. Perhaps only the finding
of a complete shell of this Laramie form will settle the questions involved.

The character of the sculpture, especially that of the central regions of the carapace,
distinguishes 4. foveatus from any other of the Judith River species with which it is likely to
be compared.

The specimens of Trionyx foveatus cited by Prof. O. C. Marsh as having been found in
the Ceratops beds near Denver, Colorado, belong probably to 4sprderetes eee hers but the
present writer has not seen the materials on which Marsh’s statement was founded.

hypo

hpo, hyoplastron; hypo, a

Aspideretes coalescens (Cope).

Plate 88, fig. 6; plate go, fig. 1; text-fig. 645.

Plastomenus coalescens, Cort, Proc. Acad. Nat. Sci. Phila. 1875, p. 9 ine description); Brit. N. A.,
Bound. Comm. Report on Geol. and Resources 49th Par., 1875, p. 337; Vert. Cret. Form. West,
1875, pp- 93, 261, plate viii, igs. 6, 7—LamBE, Ottawa Naturalist, X11, 1899, pp- 68, 70; Summary
Report Geol. Sury. Canada, 1808 (1899), p- 182- 190.—HaTcuer, Bull. U. S. Geol. Surv. No. 257,
1905, p- 74

Trionyx vagans, ?Core, Bull. U.S. Geol. Surv. Terrs., m1, 1877, p. 573.—Lamse, Contrib. Canad. Pal-
wont., HI (4 to), 1902, p. 36, plate 1, figs. 3, 4, text- fig. 2:

Trionyx coalescens, Hay, Billions and Cat. Foss. Vert. N. A., 1902, p. 454.

Plastomenus (Trionyx) ee ed Osrorn, Contrib. Canad. Paleonts rt (4 to), 1902, pp. 12

TRIONYCHIDA. 489

This species was based on a specimen which was collected in the basin of Milk River,
south of Wood Mountain, Assiniboia, British America, and which is now in the collection of
the Geological Survey of Canada. Professor Cope’s earliest mention of the name was not
accompanied bya description; but in the same year both description and figures were publisht.
The figures represent the bones half the natural size.

Professor Cope thought that there had been secured portions of both the carapace and
plastron of this species; but an examination shows that all the parts belong to the plastron.
The bones which furnisht his fig. 6 and 6a (Vert. Cret. Form. West, plate viii), instead of being
parts of costal plates, are the median ends of the right hyoplastron and hypoplastron; while
the original of fig. 7 1s made up of other parts of the same bones. In the figure here presented
(fig. 645) that portion on the left of the curved line running from A to Bis the part represented
by Cope’s fig. 7, the lower end of the latter figure corresponding to the left side of our fig. 645.
The part of the latter figure which lies on the right of the line from A to C represents the same
mass of bone as Cope’s fig. 6. The portion of our fig. 645 lying in the triangle A B C, except
the part dotted, represents a frag-
ment of bone which was present with
the others, but which Cope did not
bring into relation with the rest of
the plastron. This comes into accu-

je
eo rate contact with the other two
ee c= pieces and connects them.
eee a ere a Professor Cope thought too that
\ the sutures between the various
\ J

eae pea bones had been obliterated, but one

hoe = may be traced from end to end of

ia the united fragments. In Cope’s

A J hypo fig. 7 the suture would run perpen-

dicularly thru the middle thereof;

\ poe : while in fig. 6 it would start 23 mm.

SS below the sharp projection to the

= right of the deep notch on the right

side and cross the figure to a point

on the upper margin 37 mm. from

the extreme left angle of the figure.

Fic. 645.—Aspideretes coalescens. Plastron of type. X 1. We have in this specimen, there-

fore, a large part of the hyoplastron

and hypoplastron of the right side,

and belonging to a very large animal. It is quite certain that the remains did not belong to
the genus Plastomenus.

The width of the plastron, where narrowest, between the axillary and inguinal notches,
is nearly 70 mm., and the thickness is 18 mm. Toward the median portion of the bones the
thickness is reduced to 10 mm. or less. The process of the hypoplastron which is nearest the
hyohypoplastral suture and directed toward the midline is very short, leading to the opinion
that the fontanel between the right and left halves of the plastron was narrow.

The ornamentation of the plastral bones which form the type of this species 1s mostly
quite obscure. On the portion of the plastron forming the bridge there are rather coarse
ridges forming by their union large pits. Toward the median portion of the plastron the
sculpture becomes mostly effaced.

Mr. L. M. Lambe, of the Canadian Geological Survey, has described, under the name
Trionyx vagans, a large specimen of a trionychid, which he secured in the Belly River deposits,
in the region of the Red Deer River, below Berry Creek, in Alberta. The present writer,
regarding Cope’s type of Trionyx vagans as too small and imperfect a fragment for satis-
factory comparison with materials from any region, except the type locality in eastern Colorado,
is compelled to seek for some more probable disposition of Mr. Lambe’s fine specimen. Since
the plastron of Cope’s Plastomenus coalescens indicates a large trionychid which lived in
approximately the same region and in the same geological period, it appears to be best to
refer the Red Deer River carapace to the same species.

A, B, C, explained in text; hyo, hyoplastron; hypo, hypoplastron.

490 FOSSIL TURTLES OF NORTH AMERICA.

The carapace (plate go, fig. 1) referred to is nearly complete, wanting only the greater
portion of the nuchal; and his was fortunately supplied by another specimen of the same
size. The carapace is broader than long, slightly excavated along the anterior border of the
nuchal, and truncated behind. The upper surface was rather flat. The total length along the
midline is 470 mm.; while the maximum width is 590 mm.

The nuchal has a length, from side to side, of 290 mm. and a fore-and-aft width of 49 mm.
Its anterior border is sinuous, being excavated at the midline; its posterior border is rather
strongly convex and it joins the bones behind it without i intervening fontanel. There is present
2) preneural and 6 neurals. The preneural is coffin-shaped, with the broad end forward. Its
maximum width is 56 mm. ‘The anterior 5 neurals are also cofin-shaped, but, as usual in
trionychids, the narrow end is directed forward. The sixth neural is oval and much reduced.
No neural is interposed between the costals of the seventh and eighth pairs; and those of the
sixth pair meet behind the sixth neural. The costals of the seventh pair are relatively very
narrow, only 36 mm. in the middle of the length. The eighth costals are well developt. The
nuchal has a thickness of 18 mm. at the outer end; the first costal is 9 mm. thick at the proximal
end and 12 mm. at the distal end. The thickness at the center of the eighth costal is 10 mm.

The sculpture (plate 88, fig. 6) consists of a network of usually sharply defined ridges
which inclose pits of varying size. The ridges are, for the most part, narrower than the
diameter of the pits. “Toward the distal ends of the costals the pits are more or less transformed
into furrows which run parallel with the free border of the carapace. On the hindermost
portion of the carapace the pits are unusually large and the ridges are high. Around the whole
border of the shell there is a nearly smooth band. This is broadest at de sides of the carapace.
On each side of the costal sutures is a band consisting of low ridges which run at right angles
with the suture.

In size, general form, and sculpture, the carapace which has been referred to this species
resembles closely that here described as Asprderetes Cima The two are, however,
different in many ways. A. coalescens has 6 neurals, while 4. splendidus has 7. The nuchal
of A. coalescens is excavated in front and convex behind, while in 4. splendidus it is convex
in front and nearly straight behind. The nuchal of the latter has, likewise, a relatively greater
lateral extent. The hinder borders of the two species are somewhat different, that of 4.
splendidus being sinuously convex, with a small median notch, while that of 4. coalescens is
truncated. In 4. coalescens there is not much difference between the width of the proximal
and the distal ends of the costals of the first pair, but in 4. splendidus the distal ends are much
narrower than are the proximal ends. The same statement is true of the seventh costals of
the two species. In 4. splendidus there does not appear the same tendency toward the for-
mation of parallel furrows toward the distal ends of the costals, but rather a tendency toward
the production of square cells.

Aspideretes splendidus sp. nov.

Plate 88, figs. 7, 8, 9; plate 91; text-fig. 646

Trionyx vagans, ?Copr, Proc. Acad. Nat. Sci. Phila. 1875, p. 9; ?Bull. U. S. Geol. and Geog. Surv.
Terrs., 111, 1877, p. 573.— ?Osporn, Contrib. Canad. Paleont., 111, 1902, pp. 12, 16.

The specimen which is taken as the type of this species is a large, but somewhat imperfect,
carapace in the American Museum of Natural History. It is a part of the Cope collection of
reptiles, and was collected for Professor Cope in 1876, by Mr. Charles Sternberg, from the
Judith River basin, of Montana. It has now the number 3952. The fragments of which the
specimen consisted when it came to the American Museum have been put together, and it is
now so nearly complete that almost all portions of the carapace can be determined from one
side or the other. A slight doubt now exists only with regard to the presence of a preneural
and the amount of extension of the ribs beyond the costal borders.

This species attained a very large size. The width of the type specimen is greater than the
length, and the carapace was much deprest. The sides of the carapace are scallopt; there is
a slight sinus at the midline behind; and the anterior border formed a gentle curve, with a
slight sinus on each side of the midline.

TRIONYCHIDZ. 491

The total length in the midline is 538 mm.; the greatest width, 665 mm. The greatest
height of the center of the carapace above the distal ends of the costals is only about 70 mm.,
but in life the height may have been somewhat greater. The nuchal has an antero-posterior
extent of 75 mm., and an extent from side to side of 400 mm. There was probably a preneural
bone, but this region is damaged so that the presence of the bone is uncertain. If it was not
developt, the first neural must have been very large. Furthermore, there are some appearances
in the region in question which indicate that there was a preneural. The probable condition
in this part of the carapace is indicated in the text-figure (fg. 646). In the carapace, as restored,
there seems to be a suture between the inner anterior angle of the first left costal and a pre-
neural; but the supposed suture may be merely a fracture. There is also a fragment of bone
which appears to be a portion of the preneural and a portion of the first Nencal: but it is un-
certain whether or not the fragment belongs where it is placed. If present, the preneural was
probably wider at its anterior end than at the posterior. On the other hand, a very large
—— first neural, like that of Amyda egregra, may
—— have occupied the entire space between the first
Sy costals. The evident relationship of this species
to Aspideretes coalescens Cope, as figured by

oe ns Lambe under the name Trionyx vagans, renders

: the presence of the preneural more probable.
ee, \, Behind the preneural there were 7 neurals.
; \ ; a = These had the usual coffin-shape, with the nar-
ie ee | rower ends directed forward, except the sixth,
po axe which is oval in form, and the seventh, which
a en : . | has the broader end in front. The neurals
mostly decrease in size from the first to the last.
r\ ; The table below gives the dimensions of the pre-

sab, Se : t neural and the neurals.

{ | ce The first, seventh, and eighth costals are
considerably broader at their proximal, than at

\ ; : their distal, ends; and the first is broadest of

| — ) all, its width near the neural being 88 mm.

| : \ pon Distally it is contracted to 52 mm. The next
ae three costals are about 60 mm. wide near the
Fic. 646.—Aspideretes splendidus. Carapace of neurals, the second and the fourth about 110
type. Xd. No. 3952 A. M.N. H. mm. distally, and the third 87 mm. The sixth

and seventh costals measure about 50 mm. each
proximally, while distally their widths are respectively 108 mm., 133 mm., and 25 mm. The
eighth pair meet along the midline for a distance of 46 mm. while they form 230 mm. of the
hinder border of the carapace. The thickness of a costal at its sutural border and in the
middle of the length is to mm., while thru the rib the thickness is 14 mm. At their distal ends
the costals are beveled off to an edge.
= = —_ The ornamentation consists of abrupt and narrow ridges
Rigen: Length. Width, | Which by their union inclose pits and furrows of irregular
size and form. There are usually 3 pits or furrows in a dis-
tance of 10 mm.; but in places there may be only 2, or again,

wi heclaae pe _ asmanyas 4. They are largest on the middle of the lengths
Neural 2 60 46 of the anterior and middle moseals and over nearly the whole
iele : a A ve surface of the hindermost costals; they are smallest along
Neursi'e..-o1 a8 re the middle of the back and on the distal ends of the costals
Neural 6..... 42 2 of the anterior half of the shell. Toward the free borders of
Neva ae: 33 3 the costals the pits diminish in size, and finally the beveled

border is left nearly smooth. In some places near the distal
ends of the costals (plate 88, fig. 8) the pits are nearly quadrate and in rows.

On plate 88, fig. 7 shows the sculpture on the outer third of the second costal, the upper end
of the fgure being the more anterior, the right side being toward the middle line of the

492 FOSSIL TURTLES OF NORTH AMERICA

shell. Fig 8 represents the outer portion of the fourth left costal, the hgure being oriented as
in fg. 7. Fig. g presents the sculpture on the proximal half of the third left costal, the upper
end being toward the front of the animal.

This species differs from 4. beecher: in being more deprest, in having a greater proportion-
ate width, and in having a coarser and more irregular ornamentation. From Cope’s type of
As pideretes? vagans it seems to differ in having a coarser sculpture. From 4. coalescens Cope,
as exemplified by Lambe’s specimen described under the name of T. vagans, it differs in
having the carapace convex in front and in the different form of the nuchal and in the relatively
greater width; likewise, in possessing a greater number of neural plates and much larger
eighth costals.

Aspideretes beecheri Hay.

Plate go, fig. 2; plate g2, figs. 1, 2; plate 96, figs. 1, 2; text-fig. 647.

Trionyx foveatus, Baur, Proc. Acad. Nat. Sci. Phila. 1891, p. 418.— ?Marsu, Monogr. U. S. Geol. Surv.
XXVIII, 1897, Pp. 527:

As pideretes beechert, Hay, Amer. Jour. Sci. (4), XVII, 1904, p. 274, plate xvi; Amer. Geologist, xxxv,
1905, p. 338.

In the Marsh collection of fossil vertebrates at Yale University, there is a finely preserved
specimen of a trionychid to which the above name is given. It was collected in the year 1889,
by Prof. J. B. Hatcher and Dr. C. E. Beecher, in the Laramie beds of Converse County,
Wyoming, on the east side of Lance Creek. It is named in honor of one of the collectors,
Dr. C. E. Beecher, formerly professor of paleontology in Yale University.

This specimen was studied by Dr. G. Baur and was identified by him as Trion yx yx jove atus
of Leidy. The present writer does not agree with this identification. Leidy’s species was
based on scant materials, but the ornamentation of the costal bones is characteristic and has
led to the identification of the species by Mr. L. M. Lambe in well-preserved and complete
remains. These remains indicate a very different trionychid from the one here described.

The type of 4. beechert presents the limbs nearly complete, a portion of the neck, the tail,
the shoulder and pelvic girdles, a large portion of the carapace, and the whole of the plastron.
The skull, some costals, and most of the neurals are missing.

The carapace (plate 92, fg. 1) was nearly as broad as long, the length being close to 323
mm.; the width 310 mm. It was apparently rather convex, but has suffered some crushing
during fossilization. The front of the shell, along the nuchal, was nearly straight, but at ihe
ends of this bone the border has a scallop on ach side. The lateral borders are somewhat
sinuous. The hinder border appears to have been excavated, but here the costals are wanting.

The nuchal has a width of 30 mm. in the midline, being somewhat notcht for the reception
of the preneural, Its outer sy appears to project slightly over the first costal plate. The
preneural is of hexagonal form, 27 mm. long and 30 mm. wide. The first true neural is hexag-
onal, with the narrow end forward, as usual in the species of this family. It has a length of
32 mm. anda width of 21 mm. The second neural is of similar shape, 42 mm. long and 26 mm.
wide. The costals display nothing characteristic. “There were probably 8 of fen. The ends
of the costal ribs project beyond The disk about 17 mm. anteriorly, but posteriorly they are
longer, that of the seventh being about 50 mm., fae of the eighth probably about 70 mm.
The costals are about 5 mm. thick along their borders.

The sculpture of the carapace consists of a network of ridges inclosing rather deep pits.
Of these there are about § ina distance of 10 mm. Usually they are without definite arrange-
ment, but toward the outer ends of the costals they dispose themselves in rows parallel with fhe
margin of the shell. The bottoms of the pits are flat, and the walls rise abruptly. In Aspideretes
joveatus the pits have concave bottoms and the surrounding walls rise gradually. Often, too,
there are broad smooth spaces between the pits on the proximal ends of the costals of 4.
foveatus. In A. beecher: the sutures between the costals resemble seams in leather sewed with
fine stitches.

The plastron is complete. The entoplastron is slightly notcht in front. Its lateral limbs
include between them less than a right angle, and the length of each is 93 mm., measuring
from the anterior notch of the body ‘of the i The epiplastra are broad at their anterior
ends. They resemble much those of Platypeltrs mutica. The hyoplastra are not co-ossified

TRIONYCHIDZ. 493

with the hypoplastra. There are large fontanels in the midline between the bones just men-
tioned. The hinder of these fontanels is bounded posteriorly by the xiphiplastra. The latter
bones appear to have met along the midline without intervening fontanel. Where narrowest
the bridge is 64 mm. wide.

The whole lower surface of the hyoplastra, hypoplastra, and the xiphiplastra is covered
with a sculpture like that of the carapace, except that it is finer.

The cervical vertebra seen in plate g2, fig. 1, is probably the fifth. Its length from the
front of the prezygapophyses to the hinder end of the postzygapophyses is 64 mm.

Seven tail vertebra are present in a series 122mm. long but there were others, now missing.
The most anterior appears to be the first. These vertebre are greatly like those of Platype eltis
spinifera, but the ridge representing the neural spine is low aad sharp on the front of the
vertebra. Posteriorly it rises, becomes quite rough, and reaches a width of 5 mm. From the
highest point it descends to the hinder end of the postzyga-
pophyses, at the same time becoming broader. The centrum
of the first caudal has a length of 20 mm. The sacral verte-
bra are not preserved.

The left half of the shoulder-girdle is exposed to view.
It resembles that of other Trionychide. The distal extremity
of the coracoid is hidden in the matrix. The procoracoid
process has a length of 80 mm. The humerus is not per-
ceptibly different from that of P. spinifera. Its length
from the proximal surface of the head to the distal end 1s
95 mm. The ratio of the length of the bone to the length
of the carapace is about the same as in the living species
referred to above. The radius has a length of 44 mm.
Neither ulna is exposed its whole length. The bones of
the wrist and hand are somewhat disturbed, but they
appear not to have been different from those of living
members of the family. The first digit is strongly dev elopt
and ends in a large claw phalanx. T he claw of the second
digit was not so powerful.

The left half ‘of the pelvis is represented by only the
anterior portion of the pubis and the hinder process of the
ischium. The right half is complete, except that the upper

; end of the illum is broken off. From side to side the pubes
Fi. esc apenas beechert. measured 170 mm. The form of this part of the pelvis is
ae Xz No. 2358 practically that of Platy peltrs spinifera, The posterior pro-
aaa cess of the ischium is not so flat as in the species just named.

The femur appears to have been slightly longer relatively to the shell than in P. sprnifera.
The total length in a straight line is 110 mm. The tibia is 67 mm. long. The foot presents
nothing distinctive.

It appears probable that this individual was a male well advanced in age.

The U.S. National Museum possesses a specimen which appears to belong to 4. beechert.
This also was collected for Prof. O. C. Marsh in the Laramie deposits of Wyoming. It
bears the catalog number 2358.

There is no part of the plastron present. The median and anterior parts of the nuchal are
wanting; also the distal extremities of the first three costals of the right side; large parts of the
distal bal es of the costals of the left side; and the free extremities of all the ie,

The carapace (plate go, fig. 2; text-fig. 647) was high and vaulted. The anterior margin
is damaged. The posterior margin is furnisht with a wide shallow sinus. The total length
was close to 325 mm.; the breadth was almost exactly the same; the height, not reckoning
the plastron, was about 80 mm.

There is a preneural present, but its anterior end is eroded away. Behind this there are 6
neurals, the most posterior being small and wedged in between the proximal ends of the costals
of the sixth pair. The anterior 4 have the usual coffin-shape; the fifth is nearly four-sided;
the sixth is oval. The table on page 494 gives the dimensions of the preneural and neurals.

494 FOSSIL TURTLES OF NORTH AMERICA.

Most of the costals are widened at their distal ends. The costals of the sixth pair join
medially without interruption. Those of the eighth pair are directed backward, and join for
their full length in the midline, their distal ends forming

the median portion of the border of the shell. The free

Element. Bengthen | Width: borders of the median costals are beveled off at an angle of
about 45°; the more posterior ones are rounded on the edge.

Preneural.... 274 23 The thickness in the middle of their length is usually
ena 28 25 close to 6 mm. at the sutures, while thru the rib the thick-
Neural 2 36 23 é 5 :

Rreurales a 23 ness amounts to 8 mm. At their distal ends the thickness
Neural 4 33 22 at the sutural edges is 10 mm. and thru the rib about 12
Neural 5 28 15 : : i d . ss
Roe 8 22 mm. The ribs are quite prominent on the under side of

“| | the costal bones, and occupy about two-thirds of the width

of the plate. Most of the bodies of the dorsal vertebra
are eroded away, and there is exposed a cast of a portion of the neural cord about 5 mm. in
diameter and 160 mm. long.

The sculpture (plate 96, fig. 2) appears to agree well with that of the type of this species;
but it has suffered somewhat from weathering. On the middle of the costals there are 4 or 5
pits in 10 mm. On the neurals and the distal ends of the costals they are somewhat smaller;
on the nuchal and in places on the hindermost pair of costals, somewhat larger.

This specimen reveals to us the convexity of the carapace, as well as the form of the hinder
border.

Two carapaces have been submitted to me for examination, which had been collected by
Prof. J. B. Hatcher in the Judith River beds on Fish Creek, Montana. These bear the
numbers 445 and 541 of the Carnegie Museum, Pittsburg. No characters are observed which
serve to distinguish these carapaces from that of the type of 4. beecherr. It is not improbable,
however, that hey belong to a distinct species.

Prof. O. C. Marsh, as cited in the synonymy, has reported Trionyx ; foveatus from the
Ceratops beds near Denver, Colorado. The writer does not know on what the determination
was based; but it appears probable that the specimens belonged to 4. beecher:.

Aspideretes fontanus sp. nov.
Text-fig. 648.

From the Laramie beds at Ojo Alamo, San Juan County, New Mexico, Mr. Barnum
Brown, of the American Museum of Natural History, in 1904, brought materials belonging
apparently to 3 species of ine
genus A spideretes. Of these the
present is represented by nearly
the whole of the right half of the
nuchal and a conenernle part of
the right first costal. The number
of the specimen is 6070.

At no point does this piece of

‘ i ‘nuchal come to the midline; hence
\ a Yo \ we can not determine the exact
Seas _-~~ extent of the bone laterally. It
; \ ce was, however, not far from 260

’ | Beat mm. The animal was therefore

: \ Soe one of considerable size. The
Siete inner hinder angle of the bone
' x presents a part of the sutural bor-
der for the preneural, and from
this to the outer end of the nuchal
is 125 mm. Thewidth of the bone,
where it came into contact with the preneural, is 60 mm. The anterior border is not beveled,
but 1s cut off nearly at right angles with the upper surface. The greatest thickness, thru

Fic. 648.—ds pideretes fontanus. Part of nuchal and part
of first right costal of type.

TRIONYCHID. 495

the ridge on the lower surface, is 16 mm. Where it made contact with the preneural the
thickness is only 4 mm.

The portion of the costal, the proximal half, almost certainly belongs to the same indi-
vidual. At its proximal end it presents the sutural borders for the preneural and the first
neural. Evidently the preneural was somewhat wider than the neural. Its length was at least
4omm. The border of the costal for union with the neural is 7 mm. thick. About the middle
of the length of the hinder border of the costal the thickness is 7 mm.

The upper surface of the bone is incrusted with a layer of iron oxide; but so far as can
be discovered the sculpture was finer than in the other two species found in that region,
A. austerus and A. vorax. The few pits observed appear to be about 2.5 mm. in diameter.

The respects in which this species differs from those just named are mentioned under
their respective descriptions.

Aspideretes austerus sp. nov.
Text-figs. 649, 650.

The fragmentary specimen on which the present species 1s based was collected in 1904,
by Mr. Barnum Brown, from Laramie deposits at Ojo Alamo, San Juan County, New Mexico.
The catalog number of the specimen is 6068. The remains, belonging apparently to a single
individual, consist of the nuchal except the central portion, part of both first costals, the
greater part of a right posterior costal, probably the sixth, various fragments of costals, a
piece furnishing parts of two neurals, and a considerable portion of the right hypoplastron.

The species is characterized by the very thick bones and the coarse sculpture of both
the carapace and the plastron.

N Pd
“ 7 a
Si eee fx / 2
~S \ regs wt \ ring
= esos oes
~ 1 i r
rae ook fae: _
S 2 1 \ “
a ee
=e ; \ Pye
7 H \ os
Wes tS i \ See
ae { 4 gar
ae a ee
BH ar Ae ee
fe \
i
Fic. 649.—Aspideretes austerus. X 2. Parts of nuchal and first costals of type.

On account of the missing middle region of the nuchal, the exact lateral extent of this bone
can not be determined. It was, however, not far from 230 mm., being thus somewhat less than
that of 4. fontanus, just described, The greatest width is 45 mm., a fourth less than that of 4.
fontanus. ‘The greatest thickness of the bone is 21 mm. The free anterior border 1s not bev-
eled, but is cut off at nearly right angles with the upper surface, like that of the species just
mentioned. ‘The thickness of this border varies from 10 mm. toward the midline to 15 mm.
near the outer end.

The first costal is about 72 mm. wide near the neural border and it increases to 80 mm.
near the distal end. The free border is cut off at a nearly right angle to the upper surface.
The thickness of this border is 10 mm. or more. The hinder border of this bone is 10 mm.
thick.

The posterior, probably the sixth, costal is 25 mm. wide 110 mm. from the distal end, but
it widens rapidly to 55 mm. The free border is like that of the first costal. There must have
been a considerable notch between this costal and the one next behind. In thickness this
costal ranges between g mm. near the proximal end and 10 mm. at the distal end.

490 FOSSIL TURTLES OF NORTH AMERICA.

The sculpture of the carapace is best displayed toward the free borders. It consists of
abruptly sunken pits, of which there are usually 5 in a line 20 mm. long. Closer to the free
borders the pits are smaller. Nowhere does there appear any tendency. for the formation of

(PPO SSS we A a ote a ee eR eS ‘ straight rows of pits, such as

! \ are seen on the costals of
Amyda cartosa, of the New
Mexico Wasatch. On the por-
yee : tions of the carapace near the
en H midline the pits are less con-
iY spicuous. They appear to be
/ as large, but the walls appear
/ worn down.
za The hypoplastron (fig. 650)
is thick and heavy. At the
suture with the hyoplastron,
not far from the midline, the
thickness is 13 mm. One border of the notch for the process of the xiphiplastron remains.
This bone was articulated with the hypoplastron by a jagged suture and it must have extended
anteriorly near the midline. The outer end of the hypoplastron, near the bases of the lateral
processes, is 16 mm. thick.

Evidently nearly the whole lower surface of the plastron was covered by the sculptured
layer. The pits are smaller than those of the carapace, there being about 7 pits in a line 20 mm.
long. Many of them coalesce to form winding furrows.

This species differs from 4. fontanus 1 in having a narrower nuchal, much thicker bones,
and a considerably coarser sculpture. It is referred to As spideretes provisionally.

1
1

Fic. 650.—Aspideretes austerus. X 3. Right hypoplastron of type.

Aspideretes vorax sp. nov.
Text-fig. 651.

This species was collected from the Laramie deposits near Ojo Alamo, San Juan County,
New Mexico, in 1904, by Mr. Barnum Brown. The type is in the American Museum of Nat-
ural History and has the catalog number 6140. The species is represented, as far as known,
by only the nuchal bone; but this is complete. The length of the bone, from side to side, is
200 mm. in a straight line, 215 mm. over the curve. The lateral conv exity 1s considerable and
appears to have Bean somewhat greater than that of either 4. austerus or A. fontanus, both
from the same locality as this species. The width at the midline is 45 mm., the greatest width,
55 mm. The greatest thickness is
15mm. There is a moderate median
sinus in the anterior border. This
border is not clipt off at a nearly
right angle with the upper surface as

“< Zz in the two other species mentioned
Sa ae ee above; but is beveled down on the
upper surface of the bone to a sharp
edge. This beveled surface is not
sculptured. The hinder border of the bone presents a median excavation, for the preneural
bone. The latter bone was evidently unusually broad, the excavation having a width of at
least 55 mm. The preneural border is thicker than that of 4. jontanus, the thickness
being 7 mm.

The sculpture of the bone is obscured by a layer of hard matrix; but so far as can be
determined, it was intermediate between J. fontanus and A. austerus, approaching more
closely the latter.

Certain fragments of costals present probably belong to this species, but possibly to 4.
jontanus. One of these, apparently the right sixth, is 35 mm. wide at the neural border,
30 mm. wide more distally, and has a thickness of 8 mm.

This species differs from 4. fontanus in having the free anterior border of the nuchal
beveled, the bone thicker at the preneural border, and a coarser sculpture. From 4, austerus

i ae Wales ace

Fic. 651.—Asprderetes vorax. <3. Nuchal bone of type.

TRIONYCHID 2. 497

it differs in having a nuchal with greater antero-posterior width, the bone not so thick, and
with the free anterior border beveled off, instead of being clipt off at a right angle with the
upper surface.
Aspideretes? vagans (Cope).
Plate 96, fig. 3.

Trionyx vagans, Cope, Ann. Report U. S. Geol. and Geog. Surv. Colorado, 1873 (1874), p- 453; Bull.
U.S. Geol. and Geog. Surv. Terrs., 1, No. 2, 1874, p. 29; Vert. Cret. Form. West, 1875, pp. 96, 260,
plate vi, fig. 13—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.—Hartcuer, Bull. U.S.
Geol. Surv. No. 257, 1905, p- 73-

The type of this species is a fragment of a costal plate, which was collected by Professor
Cope in 1873, from what have usually been regarded as Laramie deposits in Colorado. From
Whitman Cross (Monogr. U. S. Geol. Surv., xxvu1, 1896, p. 244) we learn that the more exact
locality is on Bijou Creek, 40 miles east of Denver. Mr. Cross believes that the deposits belong
to the Arapahoe beds, of the Post-Laramie.

The type fragment has a length of 50 mm., a width of 37 mm., a thickness at the sutural
borders of 5 mm., and thru the rib, of 6 mm. It was figured by Cope in 1875, as cited.
Another figure of it is presented on plate 96, fig. 3. This specimen is now in the American
Museum of Natural History and has the number 1847. The other fragment figured by Cope at
the same time has been lost. Still other fragments were mentioned in the original description,
but were not described and they have now disappeared.

It is to be remarkt of Cope’s figure of the type specimen that it brings out the ridges into
too great contrast with the pits. The latter are really very shallow, and they rise gradually
from the bottom to the summits of the surrounding walls. For this reason Hatcher’s remarks
(op. cit. p. 74) regarding Lambe’s Judith River form are not pertinent.

Various specimens from Montana, Wyoming, and Canada have been referred to this
species; but after careful comparison, the writer has come to the conclusion that it is impossible
to identify any of them with Cope’s type. It seems best, therefore, to describe and name
specimens from other localities without regard to it, until better materials have been collected
in the type locality.

Whether or not the fragmentary materials which Cope has referred to this species from
near the mouth of the Big Horn River, in Montana, from the Judith River beds, from North
Dakota, and from the Milk River region of British America, belong to it is extremely doubt-
ful. Some of them probably belong to the species here described as 4. splendidus Hay, 4.
beechert Hay, and A. coalescens Cope.

It is to be noted that in the Vertebrata of the Cretaceous Formations of the West, Cope
states that there are 4 or 5 pitsin 1g mm. This is evidently a typographical error; for in the
original description there are said to be 4 or 5 pits in 10 mm., which is correct.

Aspideretes sagatus sp. nov.

Plate 93, figs. 1-3; text-fig. 652.

This species 1s represented in the collection of the American Museum of Natural History
by a complete carapace. It was collected in the year 1892, in the Puerco deposits of New
Mexico. The catalog number is 1201.

This carapace (plate 93, fig. 1; text-fig. 652) is approximately circular in form, having a
length of 375 mm. and an extreme breadth of 312 mm., exclusive of the projection of the rib-
ends beyond the margin of the shell. The front margin of the nuchal plate, in the midline, 1s
slightly concave. Behind, the shell is narrowly truncate. Transversely the shell was moder-
ately convex, less so longitudinally. All around the margin the carapace is beveled off rather
abruptly, and concavely, so as to produce a broad shallow groove. Nowhere does the sculp-
tured layer overhang the free portions of the ribs or the deeper layers of bone. The bone has
a thickness of about g mm. It is somewhat thicker in the middle of the width of the costal
plate, but not much. The costal plates also grow slightly thicker toward their free margins.

There are 2 plates between the proximal ends of the first pair of costal plates, a preneural
anda neural. The preneural is a trapezoid, whose broadest side, 50 mm., articulates with the
nuchal, while its shortest side, 22 mm., joins the first neural. The median length is 29 mm.

32

498 FOSSIL TURTLES OF NORTH AMERICA.

The first neural is hexagonal with the long sides parallel. The
Neural, | Median | Greatest second, third, fourth and fifth neurals are cofin-shaped; the

ere aay sixth neural is pentagonal and pointed behind. The table here-

i with gives the dimensions of the neurals.
; 34 5 The nuchal is firmly joined by its whole posterior border to
5 s a the first costal plates and to the preneural. Its antero-posterior
4 32 22 length is 38 mm.; its width from side to side is close to 154. mm.
5 . : Its whole upper surface, with the exception of the beveled edge,

is covered with the ridges and pits of the ornamentation. It is
therefore in form, in extent of articulation, and ornamentation
extremely different from the nuchal of T. puercensts.
The eighth pair of costals together form about 125 mm. of the hinder margin; fore and
aft in the middle line they measure 38 mm.
The sculpture (plate 93, figs. 2, 3) consists of a coarse network of ridges which inosculate
somewhat irregularly and inclose deep pits of varying sizes.
The sculpture is coarsest on the distal third of the costal
< plates, where there are about 5 pits in a line 25 mm. long;
and here there is a tendency toward an arrangement of the
stronger ridges across the costal plates. Nearer the midline
of the shell there will be found about 6 or 7 pits in this distance.
Near the free margins of the costal plates there is a tendency
for the ridges to break up into tubercles having elongated or
circular bases. It might be difficult in some cases to distin-
guish fragments of the shell of J. puercensis bearing its coarser
sculpture, from fragments of the present species bearing the
finer ornamentation. If they are marginal pieces the species
may be determined usually from the fact that the margin of
. _ P. puercensis is beveled off less abruptly and with a plane or
Se convex surface, while that of P. sagatus has the bevel abrupt
ond ae oe and often slightly concave.
ae ; This species resembles in many ways those figured by
Professor Cope on plate xxvi of his Extinct Weitebrara
obtained in New Mexico (Wheeler Survey West 100th Merid-
ian, vol. 1v). 4. sagatus, however, differs from T. le ptomitus
and 7. cariosus in not having the sculptured layer of bone
overhanging the supporting layers at the outer ends of the
costal plates; likewise, in not having the ridges of the sculpture arranged i in lines parallel with
the length of the shell.

Hic 652.—Aspideretes sagatus.
Carapace of type. X $.

Aspideretes? nassau sp. nov.

Text-fig. 653.

The only known specimen of this species was collected by Dr. Marcus S. Farr, of Princeton
University, Princeton, New Jersey, in Fort Union deposits, at Duffy’s ranch, 18 miles from
Melville, Sweet Grass County, Montana. The specimen belongs to the university named.
Only the carapace (fg. 653) is represented.

‘The nuchal one) all of both first costals except a small part of the one of the right side,
and the first and second neurals are missing. It is assumed that this species, like cose from
the approximately equivalent Puerco deposits, possest a preneural bone and belonged, there-
fore, to the genus Aspideretes. There were certainly 8 pairs of costals and 7 eneaies

The fadividual here described was evidently an aged one, since the disk oe out to
the ends of the ribs. The species was a small one. The length can not be exactly determined,
but was approximately 195 mm. The width, in a straight line, is 200 mm. The rear of the
carapace is truncated, more exactly, slightly concave in outline. The upper surface is convex
from front to back, more strongly so from side to side. The free borders are cut off nearly
perpendicularly to the upper surface and are about g mm. thick. Toward their proximal ends
the costals are reduced in thickness to 5 mm.

TRIONYCHIDA. 499

The neurals are relatively broad. The accompanying table shows their dimensions.

It is not certain that the outlines of
the seventh neural are correctly drawn in
the figure; but they appear to be as shown.
If so, this neural is of unusual form and size
for the posterior one. It did not wholly
separate the costals of the seventh pair at
the midline.

Neural. Length. Width.

rar

5

4 19 18

5 17 |
6

5 | 3

The central portions of the upper sur-
face of the carapace are nearly smooth.
Gradually toward the outer borders a
sculpture appears. On a band about 35
mm. wide around the borders this sculp-
ture is quite distinct and consists of ridges
separated by furrows and pits. These
ridges run nearly parallel with the free bor-
ders of the carapace. The furrows are usually narrower than the flat-topped ridges. A line
10 mm. long crosses four of the ridges.

Nassau, an old name for Princeton University.

ee
Fic. 653.—Aspideretes nassau. Carapace of type.
0.35. Partly restored.

Aspideretes puercensis sp. nov.

Plate 94, figs. 1-3; plate 104, figs. 2, 3; text-figs. 654, 655.

This species is represented by a single specimen, which belongs to the American Museum
of Natural History, and bears the number 1202. The right side of the carapace is nearly com-
plete, lacking only the eighth
costal and the free ends of
most of the ribs; and there
are present large portions of
the left side of the plastron.
All these parts belonged to a
single individual, which was
collected by Dr. J. W. Wort-
man and Mr. O. A. Peterson,
in 1892, in the Puerco beds
of New Mexico, probably in
the southern part of Rio
Arriba County.

Up to the present time, no
Fics. 654 AND 655.—Aspideretes species of Trionychide has
puercensis. X4. been described from the
Puerco Eocene except Con-
chochelys admirabilis Hay.
Professor Cope has credited
(Proc. Amer. Philos. Soc.,
xx, p. 461) to the Puerco deposits the Wasatch species Plastomenus communis, but it was
with a doubt, and the species was not included in later lists. Nor is it mentioned in Cope’s
Vertebrata of the Tertiary Formations of the West as belonging to the Puerco.

654. Carapace. 655. Plastron.

joo FOSSIL TURTLES OF NORTH AMERICA.

The carapace (plate 94, fig. 1) of the type of this species had a length of 330 mm. and a
breadth of 263 mm., not including the extension of the ribs beyond the costal plates. If we
include the ribs, the width was at least as great as the length.

The nuchal is a considerable bone, having had an extension from side to side of about
175 mm., and a width of about 35 mm. at the midline. Anteriorly it is somewhat excavated,
while posteriorly it is articulated with the preneural. It was not in contact with the anterior
costal plates, but its distal extremity probably overlapt the distal end of the rib of the first
costal. The connection of the nuchal with the bones behind it was, therefore, a rather loose
one. In Bell’s Monograph of the Testudinata there is a figure (plate liv) of Trionyx labiatus
(Testudo triunguis Forskal) which shows a nuchal much like that of the fossil species
here described. The living species differs, however, from 4. puercensis in not having the
nuchal articulated to either a costal plate or a median bone, only overlapping the ends of the
ribs projecting from the first costal plates.

The nuchal of 4. puercensis is thin, except for a rib-like thickening which follows the length
of the bone on the lower side. The lateral wings terminated in digitations. On the upper side
the bone is smooth and was covered with soft tissue, except a patch in the midline, 48 mm.
from side to side and 25 mm. fore and aft. This has the sculptured surface found elsewhere

Element. Length. Width.
Preneural.... 28 50
Neural 1 40 30
Neural 2 39 30
Neural 3 35 28
Neural 4 34 27
Neural 5 34 25
Neural 6 28 18
Neural 7 28 15

on the carapace. Around thisarea,
on the sides and behind, the bone
is beveled off in continuation with
the beveling of the edge of the rest
of the carapace.

Between the proximal ends of
the first costals we find 2 bones, a
preneural and the first neural.
The former is irregularly penta-
gonal, with the broadest side artic-
ulating with the nuchal. The two
shortest sides lie in a notch of the
first neural. The anterior 5 neurals
are elongated hexagonal, with the
broadest end directed posteriorly. ‘The next neural is quadrilateral, while the last is nearly
triangular. The dimensions of the preneural and the neurals are given in the table.

The first costal is the broadest of all. In front and laterally it is beveled off from the
sculptured layer to the inner surface. Medially it articulates with the preneural and with the
long side of the first neural. he width of the succeeding costals diminishes toward the rear.

The thickness of the costals is pretty uniformly 7 mm. near the sutural borders, and g mm.
thru the rib. The latter extended beyond the edge of the costal plates for a considerable
distance; in the case of the rib of the second costal, somewhat more than 50 mm. The ribs
are broad, occupying about half the width of the costal plates.

Of the plastron (plate 104, figs 2, 3; text-fg. 655) there are present the left hyoplastron,
the left hypoplastron, and part of the right xiphiplastron. These elements do not differ in any
important respect from the same bones in living Trionychide. Altho they are quite thick,
they are not unusually large. The width of the hyoplastron and the hypoplastron taken
together, measured across the narrowest part, is 55 mm.; and of this width each occupies one-

Fic. 656.—As pideretes stngularts. x i, Carapace of type.

TRIONYCHID. 50!

half. Toward the midline the hypoplastron becomes much wider than the hyoplastron.
The hypoplastron sends inward a finger-like process, which no doubt joined a similar process
from the bone of the opposite side. The median border of both bones was very obliquely
beveled. The greatest thickness of the hypoplastron is 12 mm. The xiphiplastron present
appears to belong to the right side. It has a central, thick portion, sculptured, oval, 25 mm.
wide, and about 40 mm. long. This passes by a bevel into the thinner portion on all sides. The
thinner part extended forward into digitations joining the hypoplastron, and posteriorly into
others which connected with the corresponding bone of the opposite side. It is evident that
there were large fontanels between the right and left halves of the plastron.

The sculpture (plate 94, figs. 1-3) consists of a network of ridges which inclose pits of
rather regular form and size. The pits are of somewhat greater diameter than the ridges sur-
rounding them. On the neurals there are about 5 pits in 12 mm., while on the hindermost
costals there are only about 3 in the same distance. The pits increase somewhat in size from the
proximal toward the distal ends of the costals. There is no tendency, near the free margins
of the costals, toward either the disappearance of the ridges or toward their breaking up into
tubercles. There are no welts on the surface such as we find in species of Plastomenus.

The sculpture of the plastron is greatly like that of the carapace. The sculptured part of
the hyoplastron is nowhere more than 30 mm. wide, while that of the hypoplastron 1s 53 mm.

Aspideretes singularis sp. nov.

Figs. 656-662.

The type of this species 1s a nearly complete specimen which was collected for Prof.
E. D. Cope, by Mr. David Baldwin, in 1883, from the Torrejon beds of Chaco Canyon, San
Juan County, New Mexico. It furnishes the oldest-known trionychid skull that 1s accom-
: panied by the shell.
Conchochelys admtra-
bilts, of the underlying
Puerco beds, furnishes
an older skull, but the
shell is entirely un-
known.

The carapace (fig.
656) must have been
rather convex, but the
convexity was probably
increast during fossili-
zation. The length is
350mm. The width of
the disk could not have
exceeded 280 mm. Be-
yond this the rib-ends
extend 50 mm. on each
side. Therefore the
whole width of the
carapace was about
380 mm. It is com-
posed of the nuchal, a
preneural, 7 neurals
and 8 pairs of costals.

Fic. 657.—Asprderetes stngularts. Plastron. » i, f The nuchal extends

+ rom side to side 190

mm.; fore and aft, 37 mm. The outer ends of the bone are smooth, the central portion is
pitted. The free borders of the carapace are beveled and smooth, but the general surface
is carved into ridges and inclosed pits. On the neurals and adjoining parts of the costals
the pits are nearly circular and there are 3 or 4 of them ina line 20 mm. long. Distally the

Ea lrg

502 FOSSIL TURTLES OF NORTH AMERICA.

pits are larger. On the outer ends of the costals the pits are mostly in rows and there are only
three or four in a line of the length given.

All the parts of the plastron (fig. 657) are present. The limbs of the entoplastron are 112
mm. long. The epiplastra are 18 mm. broad anteriorly and about 100 mm. long. The hyohy-
poplastral suture is 143 mm. long. The bridge is 56 mm. wide. Each xiphiplastron is 110
mm. long and 75 mm. wide. The sculpture of the plastron is finer than that of the carapace.

The skull (figs. 658-660) is complete and little distorted. It resembles closely that of
Platypeltis ferox, but the profile descends more abruptly from the middle of the orbits. The
length from snout to occipital condyle is 102 mm. From the outside of one quadrate to that
of the other is67 mm. The orbits are large, the diameter being 20 mm. The roof of the mouth

Fics. 658-662.—As pideretes singularts. Parts of type. x4.

658. Upper view of skull. 659. Lower view of skull.
660. Right side of skull. 661. Fore leg. 662. Hind leg.
is mostly concealed by the bones of the tongue. It is seen, however, that the choanz are placed
25 mm. behind the tip of the snout. The ‘shoulder-girdle and bones of the foreleg (fg. 661)
differ little from those of the living species just mentioned. One forefoot is nearly complete.
The pelvis and hinder limbs (fg. 662) offer no peculiarities. The bones of the hinderfeet
are not completely preserved.

The sculpture of this species resembles that of A. sagatus and A. puercensis. From the
former it differs in having a larger portion of the nuchal bone devoid of sculpture and in having
this bone extend much farther across the outer end of the first costal. From 4. puercensis it
differs in having the nuchal more closely joined to the first costals and a coarser sculpture
on the outer ends of the costals. There are differences in the plastra of the two species.

TRIONYCHID#.

Gn
me)
wW

Aspideretes? guttatus (Leidy).
Text-figs. 663, 664.

Trionyx guttatus, Lrtpy, Proc. Acad. Nat. Sci. Phila. 1869, p. 66; U. S. Geol. Surv. Wyoming, etc.,
2d (4th) Ann. Rept. F. V. Hayden, 1871, p. 367; U. S. Geol. Surv. Montana, etc., 5th Ann. Rept.,
F. V. Hayden, 1872, p. 3793 Cont. Ext. Vert. Fauna West. Terrs., 1873, pp- 176, 342, plate ix,
fig. 1.—CoPE, Ext. Bat., Rept., and Aves N. A., 1869, pp. 151, 152; U. S. Geol. Surv. Terrs.,
6th Ann. Rept. F. V. Hayden, 1873, p- 617; Vert. Tert. Form. West, 1884, p. 119.—Hay, Bibhog.
and Cat. Foss. Vert. N. A., 1902, p- 454-

Aspideretes? guttatus, Hay, Amer. Geologist, XXXV, 1905, P- 335-

Dr. Joseph Leidy’s type of this species was discovered at Church Buttes, near Fort Bridger,
Wyoming, in the beds of the Bridger Eocene. It consists of a portion of the third neural plate,
the fourth, fifth, sixth, and seventh neurals; portions of the third, fourth, fifth, and sixth
costals of the right side; the proximal ends of the fifth, sixth, seventh, and eighth costals
of the left side; and the complete seventh and eighth costals of the right side. The materials
are therefore not very satisfactory. The form of the shell can not be determined, nor with
certainty the presence or the absence of a preneural. The species has here been referred with
doubt to Aspideretes. To add to our difficulties the type appears to have disappeared from
view. Cope referred to this species some of the materials collected by him in the Bridger beds,
but his specimens were very fragmentary and do not appear to have furnisht him with ad-
ditional information. It is questionable whether or not the nearly complete carapace collected
by him in the Wasatch beds of New Mexico really belongs to the species. Unfortunately this
carapace is now lost, along with the greater part of Cope’s other remains from that region.

Leidy supposed that the carapace described by him had originally had a length of about
375 mm. The bones had a thickness of about 8 mm. Most of the neurals are nearly twice as
long as wide, and there is a reduced one between the costals of the seventh pair. The costals
and neurals are described as being sculptured for the most part with broad, rounded, and
isolated concave pits resembling the impression of rain drops on a soft surface. Near the bor-
ders of the shell these become somewhat confluent. The walls surrounding the pits are broad
and low and often as wide as the pits. There are 2.5 or 3 of these pits in a line 10 mm. long.

The American Museum expedition of 1903, sent into the Bridger region near Fort Bridger,
secured, in the Grizzly Buttes, a specimen, No. 6005, which is referred with confidence to
this species. It consists of a portion of the carapace corresponding nearly with that of the type,
together with a large portion of the plastron. The fragment of the carapace agrees in all
essential respects with the figure and description furnisht by Leidy. However, the sixth
neural plate is segmented into two portions. The costals appear to have been somewhat
thicker, ranging from 7 mm. to 10 mm. The distance from the hinder border of the eighth
costal to the anterior border of the sixth is 112 mm. In Leidy’s specimen this distance, accord-
ing to his figure, was 133 mm. Fig. 663a is composite, being constructed partly from the
specimen just described and partly from No. 5993 A. M.N. H., described below.

The plastron (fg. 663) is represented by nearly the whole of the right hyoplastron and a
fragment of the left; the whole of the right hypoplastron and a fragment of the left; and both
nearly complete xiphiplastra. At its median end the border of the hypoplastron is filled out to
the extremity of the process which meets that of the opposite bone at the midline, thus
indicating an old individual. The bones are thick and heavy. On the bridge, at the suture
between the hyoplastron and the hypoplastron, the thickness is 17 mm. The bridge, where
narrowest, is 79 mm. wide. Of this width the hyoplastron occupies 49 mm. Nearly the
whole of the lower surface of both bones is roughened or granulated. However, the outer end
of the hypoplastron is sculptured with ridges and tubercles, of which there are about six Ina
distance of 10 mm. A similar, but more indistinct sculpturing occupies the lower surface of
the outer end of the hyoplastron.

The xiphiplastra are triangular in form, and had a fontanel between their inner borders.
Each has 2 processes for articulation with the corresponding hypoplastron. Two processes of
the left xiphiplastron received between them a single process of the right. The lower surface
of the two bones is roughened, but not sculptured.

Fig. 664 represents the pelvis of this specimen.

504 FOSSIL TURTLES OF NORTH AMERICA.

A specimen of a large trionychid collected in 1903, in the western part of Grizzly Buttes,
is referred to this species. Its catalog number in the American Museum of Natural History is
5917. It consists of the outer ends of the nuchal, the greater portion of the right first costal,
the outer ends of the left first and second costals, various portions of other costals, 1 neural, and
fragments of other parts of the skeleton. The individual was a large one. The first costal
near its proximal end was about 75 mm. wide fore and aft; the second costal has a width
equally great. The sculpture appears to be identical with that of No. 6005, consisting of large
flat-bottomed pits, surrounded by walls with rounded summits. As in No. 6005, there is a
band near the free margins of the carapace which has no pits, but which presents a fine net-
work of bony fibers, resembling a textile fabric. On the rear of the carapace of No. 6005 this
band is narrow. In the case of No. 5917 the band is considerably broader, 25 mm. or more.

Fics. 663 AND 664.—Asprderetes guttatus.

663a. Carapace. XX}. 663b. Plastron. x}.
664a. Pelvis, seen from left side. X}. 664b. Pelvis, seen from below. 4.
The width of the outer end of the nuchal bone exceeded 65 mm. The length of the bone from
side to side was about 230 mm. Apparently only a relatively narrow strip on the posterior
border of the nuchal was occupied by a pitted surface. In front of this there was an area
about 25 mm. wide with the textile-like appearance noted above. The ends of this element
present ordinary bony tissue. The outer extremities of the nuchal overlapt the free ends of
the ribs of the first costals.
The sutural borders of the costals present a band devoid of pits and 1s finely striated at
right angles to the sutures.
Future discoveries must decide whether or not this identification of No. 5917 is correct.
Still another specimen, No. 5993, collected in 1903, in the eastern part of the Grizzly
Buttes, must for the present be referred to 4. guttatus. The carapace is nearly complete, but,

é

TRIONYCHID#. 595

like No. 5917, lacks the median portion of the nuchal and the anterior neurals. Furthermore,
the sculptured layer has been split off the nuchal. The length of the carapace was close to
420 mm.; the width, 360 mm. The sixth neural was not completely developt and it permits
the costals of the sixth pair to join behind it. The seventh neural is only 15 mm. long and 10
mm. wide, and it is wedged in between the sixth and seventh pairs of costals.

The nuchal had a width of 60 mm. from front to back, at a short distance from the midline.
It is evident from the right fragment of the nuchal and the right frst costal that there was
between the nuchal and the first costals, one on each side of the first neural, a pair of fontanels.
Similarly placed fontanels are found in Platypeltis leucopotamica. In 4. guttatus these fontanels
were about 25 mm. fore and aft and at least 20 mm. from side to side. Between the fontanels
of No. 5993 is a small triangular plate of bone which may represent the preneural. On account
of this bone, this species is referred to the genus Aspideretes. Without this it would fall into
the genus Amyda.

This specimen 1s nearly devoid of the smooth marginal band of interlaced bony fibers so
conspicuous in No. 5917.

As stated above, Professor Cope furnisht a brief description of a nearly complete carapace
obtained by him in the Wasatch beds of New Mexico and referred by him to this species
(Wheeler Survey, 1v, p. 46). According to this description the nuchal underran the first
costal. This is not the case with the specimen described above and it is concluded theretore
that the Wasatch specimen does not belong to the same species as Leidy’s type.

Aspideretes ellipticus sp. nov.
Plate 95, figs. 1-3; text-figs. 665, 666.

The description of this species is based on No. 1117 of the American Museum of Natural
History, a specimen which was obtained in the Bridger beds of northeastern Utah by the
American Museum Expedition of 1893.

The carapace (plate 95, fig. 1; text-fig. 665) is complete; the plastron is wholly missing.
In form the carapace is more elongated than usual, rounded in front, only shghtly truncated
behind. The borders, especially the anterior and lateral, are sinuous. From side to side the
carapace is gently archt. The total length is 400 mm.; the width, not regarding the convexity,
is 305 mm. The greatest width is at the middle of the length, and from this the margin pro-
ceeds with similar curves forward and backward. The thickness of the costals is about g mm.
at the sutures, but somewhat greater thru the ribs. Along the sides of the carapace the upper
and lower layers of the bones project beyond the median layer, thus producing a groove. The
lower layer extends far out on the distal ends of the ribs.

Behind the nuchal there is a preneural, followed by 6 neurals. The table herewith presents
the measurements of these bones.

The forms of these bones are shown in the figures.

The nuchal has an antero-posterior extent of 50 mm. and a lateral extent of 162 mm. Its
outer extremities overlap the projecting ends of the ribs of the first costals. A band in front
— ‘and at the extremities is not occupied by the sculptured

layer of bone. The anterior costal bone is large, having a

Element Length orca tee cs 7 a Tk q 7 ;
; sth. “Width. | width at the proximal end of 67 mm. The free portions of
a a : most of the ribs project beyond the margin of the carapace at
Bealuns 38 2 least 40 mm, The costal plates of the sixth, seventh, and
| Neural 1. 37 | 28 | eighth pairs meet along the midline. Those of the eighth pair
| Neural 2 48 25, | are well developt.

Neural 3.... 46 24 a i | eipetare etal seo piaiihe
Weiralg rf a _ The sculpture of the carapace (p ate 95, figs. 2, 3) con-
Neural 5 40 17 sists of large, rather shallow pits, which are separated by
Neural 6 22 II y

ridges whose summits are rounded. Of these pits there are
aoa 7 4 or 5 ina line 20 mm. long. They are largest on the hinder
half of the shell. There is only a slight tendency toward confluence into rows and furrows.
On the neural bones the pits are not so distinct as on the costals.
The type specimen of 4. ellipticus was buried in a matrix of rather coarse sandstone.
A second and larger specimen of this species was collected during the summer of 1903 in
the Bridger deposits of the western part of Grizzly Buttes of Wyoming. Its catalog number

506 FOSSIL TURTLES OF NORTH AMERICA.

in the American Museum of Natural History is 5930. The convexity and the outline of the
carapace are very similar to those of the type. The front margin is somewhat more excavated
than in the type, and the lateral borders are more sinuated. This is caused by the extension
of the sculptured layer out on the distal ends of the ribs.

The length of the specimen is 450 mm.; the greatest width, 380 mm. The preneural is
relatively broader anteriorly than in the type, and the sixth neural is not developt. In the
latter respect we may find variations in our living species of Trionychide.

With this specimen from Wyoming comes a considerable portion of the plastron. This
includes the median half of the left and a fragment of the right hyoplastron, and a considerable
part of the right hypoplastron. These bones are thick and heavy, the thickness of the bones
along the suture joining them on the narrowest part of the bridge being 16 mm. From this
point the thickness is reduced each way to about 10 mm. at the median: and outer borders of
the bones. At the narrowest part of the bridge the width of the hyoplastron is 50 mm.; of the
hypoplastron, 42 mm. The xiphiplastron ihas joined the hypoplastron by the hel two
digitations. The lower surfaces of the hyoplastra and the hypoplastra are occupied by a

Fics. 665 AnD 666.—Asprderetes ellipticus.

665. Carapace of type. X14. 666. Plastron. X}.

nearly obsolete sculpture of pits and ridges. This is most distinct on the outer ends of the
bones, where we find 3 pits in a line of 10 mm. This sculpture and the bone supporting it
have approacht nearly to the midline, an indication that the individual was an old one.
The hyoplastra and hypoplastra resembled closely those of Platypeltis ferox, of Florida.
Text-fig. 666 represents what is known of the plastron of this species. The figure is con-
structed partly from the specimen just described, partly from the following one.

A still larger example of this species was collected during the summer of 1903 near the
mouth of Cottonwood Creek, Wyoming. Its catalog number in the American Museum of
Natural History is 5979. The bones of the iedan line and of the left side are complete,
except that the third neural is wanting and portions of the fifth, sixth, and seventh costals. -
Some parts of the right side are present. The right hyoplastron is quite complete.

The length of this specimen is 510 mm.; the width was close to 445 mm. It displays a
greater convexity of the carapace than is seen in the other specimens. The nuchal and the
preneural resemble closely those of the type. The sixth neural is present, but small. Altho
the individual was so large and evidently aged, the free ends of the ribs project beyond the
margin of the carapace a distance of about 40 mm. The hyoplastron is identical with that of

——

————

TRIONYCHID. 507

No. 5930. The outer anterior process was evidently flattened, not terete as usual in trionychids.
The pits and ridges of the median end are quite distinctly seen. The width of the bone where
narrowest is 53 mm.

The species resembles most closely 4. guttatus (Leidy). From the latter it differs in being
more elongated, the width being coneained’s in the length seventy-six hundredths times, in A.
guttatus, eighty- -five hundredths times. The sculpture of A. ellipticus i is coarser, there being
4 or § pits in a 20 mm. line, while in 4. guttatus there are 5 or 6 pits in the same distance.
The bridge of the plastron of ell: pticus is wider relatively to the length of the hyohypoplastral
suture than was 4. guttatus. A. guttatus has fontanels in the front of the carapace; while
A. ellipticus has none.

This species resembles closely the form described in this work as 4. grangeri. The
distinctive characters are discust under the latter species.

Aspideretes grangeri sp. nov.

Plate 97, fig. 1; text-fig. 667.

Among the fossils collected by Mr. Walter Granger, head of the American Museum
expedition to the Bridger beds in 1904, was the fine carapace represented on plate 97,
fig. t. Only a portion of the middle region at the rear is missing. The specimen bears
the catalog number 3942. It was collected on Cottonwood Creek, about half a mile below
the Henry’s Fork stage road. The level is given as B*; that is, the upper portion of the
middle Bridger.

The total length of the carapace (plate 97, fig. 1; text-hg. 667) was 383 mm.; the width
of the disk, 317 mm.; the width to the free ends of the ribs, 343 mm. The carapace is con-
siderably archt from side to side, the midline of the fossil rising to a height of 105 mm. above
the tips of the free rib ends. In outline the carapace is broadly oval, or elliptical, slightly
excavated in front, and probably slightly truncated in the rear. Asin J. ell pticus, the upper
layer of the carapace overhangs Sore hat the middle layer, so that a sort of gutter runs
around the edge of most of che’ carapace. The free border of the fifth costal plate i is 7mm.
thick near the suture, and 11 mm. thick thru the rib. The nuchal has an extent from side to
side of 190 mm.; a fore-and-aft extent of 40 mm. As in 4. ell: pticus, there is a smooth band
along the front and the ends of the nuchal. It runs at a lower level than the pitted surface.
It is about 7 mm. wide at the midline, and 23 mm. at the ends of the bone.

There are a preneural and 6 neurals. Possibly there was a seventh neural of small size.
The table below gives the dimensions of these bones.

At their proximal ends the costals of the first pair have a width of 59 mm. At the distal
end they are only 39 mm. The next four have the proximal ends equal in width to the lengths
of their respective neurals. The distal end of the costals of the second pair is expanded toa
width of 88 mm. This may be an individual variation. The costals of the sixth pair probably
joined each other for a part of their width at the proximal
ends. Those of the next two pairs certainly joined their

eM Sutt re eo al fellows at the midline. The lateral extent of each costal of
| ~~ the eighth pair was close to 36 mm. The free ends of the ribs
Preneural..... 26 23 of the median costals projected about 37 mm. beyond the
| eS apt | 8 a border of the disk.
Ae a i? ; The sculpture of this species consists, as 1s usual in the
| Neural 3...... 44 27 Pp if O ,
ite Aevees eal 26 family, of a network of ridges surrounding shallow pits.
| Neural 5..... 38 2 “ : : ‘
eeteeabee > 4 The ridges are rounded on their summits. On the outer
| Neural. 65. ..<... | 29 15

| | third of most of the costals the pits are arranged in rows

running parallel with the adjacent border of the carapace.
On the nuchal, the neurals, the costals GE the first pair, and the proximal two-thirds of the
other costals, the pits are irregularly but evenly distributed. On the greater part of the cara-
pace there are 5 or 6 of the pits in a line 20 mm. long. On the anterior third of the carapace
there may be as many as 7 ina line of the length given. Most of the costals have a narrow
smooth band along the intercostal sutures.

508 FOSSIL TURTLES OF NORTH AMERICA.

This species needs to be compared with A spideretes ellipticus and A. guttatus. The form of
the carapace is about the same in the three. It is broader than in the type of 4. ellrpticus, but
slightly narrower than in another specimen. The pre-
neural of the species last named is, in all the known
specimens, considerably longer and broader than in the
type of 4. grangert, while the neurals are broader. The
proximal ends of the costals of the first pair are narrower
in A. grangert than in A. ellrpticus, their width being
contained in the length of the carapace 6.33 times in the
former and only 5.5 times in the latter. The nuchal is
longer, its length being contained in the length of the
carapace two times; in A. ellt ptic us twoand a hale times.
The sculpture of the carapace is coarser in 4. ellipticus
than in 4. grangeri, there being in the former 4 or 5
pits in a line 20 mm. long while in the latter there are
from 5 to 7. In making comparisons between the pits of
the two species, measurements must be taken on corre-
sponding parts of the shell; 36 measurements taken on
all parts of the carapace of 2 specimens of 4. ellipticus
show that there are, on an average, 4.44 pits in a 20 mm.
line; 18 measurements made on corresponding parts of
the carapace of A. grangeri indicate an ayerage of 5.83
pits in the distance mamede that 1s, the pits of he former

p ; species have an average diameter of 4.5 mm. while those

1G OO}. “As pidenetes grangert, of the latter have an average diameter of mm., a

Carapace of type. 4. : . : 5 343s
2 difference of a little more than 1 mm. In 4. ellipticus
the small pits are found almost wholly on the nuchal and close to the border of the shell toward
the front. The writer regards the finer sculpture of the specimen here described as an indi-
cation of a distinct species.

The sculpture of the carapace of this supposed species is apparently identical with that
of 4. guttatus and it is possible that the specimen ought to be referred to the latter species.
However, the type of 4. granger: has a well-developt preneural bone and no fontanel on each
side of it; whereas, the specimen of A. guttatus has large fontanels and only a rudimentary
preneural. 4. grangert is a strongly archt species. It is possible that the flatness of all the
specimens of 4. guttatus is due to distortion during fossilization.

é

,
‘
SIN
“
‘

wr a 4

Genus AXESTEMYS Hay.

Axestus, Copr, Proc. Amer. Philos. Soc., x11, 1872, p. 462. (Preoccupied in entomology.)
Axestemys, Hay, Amer. Geologist, xxiv, 1899, p. 348.

Plastron, so far as known, without the usual pits and ridges. Nuchal bone partly separated
from the first costals by fontanels. Probably no preneural.

Type: A xestus byssinus Cope.

Professor Cope based the genus 4 xestus on the species 4. byssinus, which was represented
by the left xiphiplastron, most of the pelvis, the larger portions of both femora, both humeri
with distal ends missing, the right scapula and eeracoil complete, a cervical vertebra, two
sacrals, a few caudals, and some phalanges. This type belongs to the U. S. National Museum,
but the caudal vertebra and the phalanges appear to have been lost.

The character on which Cope relied for separating this genus from other genera of Trio-
nychidz is found in the absence of superficial sculpture on the lower side of the plastron, and
the presence there of a layer which “‘is marked with decussating lines of osseous deposits, as in
woven linen.” The other characters given by him in his generic descriptions are probably
common to most of the Trionychide.

This layer of decussating bony fibers (plate 104, fig. 4) is also common to various fossil
and living species of Trionychide, and may be seen in bach the carapace and the plastron of
Platypeltis spinifera near the borders of the bones where the sculptured layer thins out.
As Cope says, such a layer is found in the dermal scutes of the Crocodilia; and Marsh has

TRIONYCHIDA. 509

described and figured the dermal scutes of a dinosaur, Nodosaurus textilis, which are markt
by similar, but coarser, interwoven bony fbers

However, since there appears to be an unusual abundance of this layer of fibers and a
nearly complete absence of the sculptured layer, the so-called callosities, it appears advisable
for the present, to retain the species in a distinct genus. There are reasons for believing that
the nuchal bone also will offer some characters when it is completely known.

Axestemys byssina (Cope).
Plate 104, fig. 4; text-figs. 668, 669.

Axestus bysstnus, Corr, Proc. Amer. Philos. Soc., x11, 1872, p. 462 (4. bystmus, misprint); U.S. Geol.
Sury., 6th Ann. Rep., 1872 (1873), p. 616; Vert. Tert. Form. West, 1884, p. 116, plate xv, figs. 1-12.
Axestemys byssinus, Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 455; Amer. Geologist, xxxv, 1905,

P- 337:

The type of this species, now in the U. S. National Museum at Washington, has been
studied by the present writer. The type was found on Black’s Fork of Green River; the second
specimen on upper Green River. Both probably belong to level B. These bones were figured
by Cope in his great work The Vertebrata of the Tertiary Formations of the West, the
figures having half the size of nature. These bones are from 2. 33 to3 times as large as the cor-
responding ones of a specimen of Platypeltis whose carapace is 147 mm. long. The animal
therefore had a carapace probably over 420 mm. in length.

The xiphiplastron (plate 104, fig. 4; text-hg. 668) difcrs from that of Platypeltis spinifera
in having the posterior process narrower and more elongated and in having the callosity wholly
devoid of the layer which ordinarily furnishes the sculpture, but composed of a layer of
textile-like fibers of bony tissue. The thickness of the central portions of this bone is 10 mm.,
that of the living species just referred to being about 3 mm. Hence the thickness of the
plastron of the fossil species under consideration is proportionally as great. The greatest
length of the fragment of xiphiplastron is 166 mm. It probably had a length originally of
188 mm. The shoulder-girdle seems not to have differed in any important respect from that of
Platypeltis spinifera. The humerus, so far as represented, is like that of the living species
referred to, except that the head appears to have been more narrowly oval, with the plane
thru the long axis parallel with the long axis of the shaft of the bone.

The femora are like those of Platypeltis spinifera, except that there is a very distinct ridge
on the middle of the upper surface of the distal half of the shaft. The pelvis appears not to
have offered any difference worthy of mention. The cervical vertebra which has been preserved
is certainly the seventh, agreeing in every way with that of Platypeltis spinifera. Its centrum
is just 3 times as long as that of the corresponding cervical of the specimen of Platypeltis
referred to above.

Professor Cope mentioned another bone, a hypoplastral, which, on account of its great
thickness, he thought might belong to a distinct species. This bone is now in the possession
of the American Museum of Natural History and bears the number 1034. Its greatest thick-
ness, about the middle of the bone, is 14 mm. and this is not so much greater than that of the
xiphiplastron that it can not belong to the same species. The lower surface is like that of the
xiphiplastron of the type. The form of this bone does not differ from that of the same bone of
Platypeltis.

The American Museum also possesses a number of bones which include the greater
portion of the left half of the nuchal, most of the left first costal, fragments of ever other
costals, and a fragment of plastral bone. They bear the Museum’s number 1046. The
nuchal bone shows ; conclusively that the species 1s not T. scutumantiquum, which is suggested
by the character of the sc ulpture; while the remains of the plastron prove that they Belo to
Axestem YS. The latter are thick, and hence are undoubtedly of the same species as the thick
hypoplastral mentioned by Cope. Until additional materials are forthcoming we may refer
them to 4. byssina. The piece of the plastron of No. 1046 is about 8 mm. thick. near the base
of one of the processes directed toward the midline, and the lower surface has the textile-like
surface of the type specimen of the species. The portion of the nuchal (fig. 669) remaining has a
fore-and-aft extent of 53 mm. and a total lateral extent of 102 mm. The mesial end approaches

510 FOSSIL TURTLES OF NORTH AMERICA.

close to the midline. Seventy-five millimeters of the front border of the bone is present.

The greatest thickness of the bone is 12 mm., but most of it is thinner. The posterior half of

the upper surface is ornamented with a system of well-defined and rather sharp ridges which
inclose pits. Of these there are 3 or 4in 10 mm. The anterior half of the surface was devoid
of ornamentation, but is markt by numerous grooves and perforations for blood-vessels. The
connection of the nuchal with the first neural and the first costal was apparently like that

found in T. puercensis. There remains on the posterior border of the nuchal about 20 mm. of

the dentated sutural edge for union with the first neural. Distad of this the border is smooth
for a distance of 30 mm.; so that there have evidently existed between the nuchal and the first
pair of costals two elongated fontanels, separated by the anterior neural. At the distal end of
each fontanel the border turned backward, to come into contact with the costal. What the
breadth antero-posteriorly of this fontanel was, we can not say, but since there appears to have
been only a single neural between the first pair of costals, the fontanel was probably narrow.

The greater part of the first costal is present, only the distal extremity being gone. The
average thickness is about 8 mm. The greatest fore-and-aft extent is 57 mm.; the lateral
extent is a little over 100 mm., the thickness, 6 mm. The bone was originally about 125 mm.
long. The anterior border for about 35 mm. proximally did not articulate with the nuchal,
ue formed the posterior border of the fontanel already mentioned. Distad of this, the front
edge of the bone was deeply grooved for the hinder edge of the nuchal. The proximal end of

en aa

hypo

Fics. 668 AND 669.—A xestemys byssina.

ub
4°

668. Plastron. Xiphiplastron of type; hypoplastron from
No. 1034 A. M. N. H.
669. Part of nuchal and left first costal.

the bone articulated with the first neural. The direction of the proximal border shows that
the anterior neural was broader at the anterior end than behind. The hinder border of the
costal is jagged, for sutural union with the next costal. The rib-end of the first costal plate
seems to have been overlapt by the outer end of the nuchal.

This species was a large one. The free borders of the costals were beveled off very ob-
liquely to a sharp edge and on this beveled surface decussating bony fibers, like those of the
plastron, are seen in abundance. How far the free portion or the ribs extended beyond the
border of the carapace can not be determined, but the distance must have been considerable.

The sculpture of the costals resembled that of the nuchal; but, in places at least, the pits
are larger and the ridges sharper. The walls slope away gradually toward the bottom of the
pits. There is little or no tendency toward the arrangement of the pits in rows.

There appears to be sufficient reason for believing that the plastral and the carapacial
bones here described belonged to the same individual.

Genus AMYDA Oken.

Carapace normally with 8 pairs of costal plates. No preneural present. One or more of
the posterior pairs of costals may be in contact on the midline, or all may be separated by the
neurals. Young in living forms with numerous longitudinal dorsal dermal ridges or series of
tubercles.

Type: Trionyx euphraticus Daudin.

TRIONYCHID. sil

The living species included by the present writer under this genus are those embraced
under the heads 1, A and 1, B, 2 and 3, of Dr. Boulenger’s synopsis of species, on page 244 of
his Catalogue of Chelonians. The type of the genus is Trionyx euphraticus of the same work.
It is possible that Trionyx subplanus Geoffr. ought to be regarded as the type of the genus
Dogania. Besides the fossil North American species whose remains are complete enough to
prove that they belong under the present genus, a considerable number of others are placed
here provisionally.

For a discussion of the name A myda see Stejneger, Science, XXI, 1905, page 228.

As remarkt under the genus 4s pideretes it seems most probable that the upper Cretaceous
species placed here under Amyda really belong under As pideretes.

Key to NortH AMERICAN SPECIES OF AMYDA.

A‘. Upper Cretaceous species:

1. Sculpture coarse, mostly of circular pits, about 4 in line of 16 mm.............. prisca
2. Sculpture still coarser; 3 pits in line 15 mm. long; pits deep, rising gradually to
summit of wall....... : Pan ate ie Bia ad bray Sung eat) aidt eco: phi aha ae Bie Glia gs eh@y Bldaaieaee! a halophila

A*. Species of Atlantic slope Eocene:
1. Middle of costal with irregular pits, the sutural borders with ridges somewhat

oblique to the borders; about 2 ridges in a 10 mm. line.................... pennata
2. Costals much thicker than in pennata; pits and ridges coarse as in pennata
but irregular or in rows at right angles with the sutural borders............. virginiana

A*. Wasatch species:

1. Costals thick and growing thicker toward outer end; sculpture coarse; irregu-

larly arranged and deeply imprest pits; 4 or 5 in line 20 mm. long........... cartosa
2. Costals thick; sculpture mostly of winding and anastomosing ridges inclosing

pits and short furrows; 2 or 3 ridges crost by line'of §: MMs... 3. ic os esas ventricosa
3. Costal bones thinner than in cariosa; the sculpture similar................-. radula

A‘. Bridger species:
1. Carapace nearly as wide as long; front of nuchal long and nearly straight; with

a smooth band infront; 5 or OV pits im) 20MM. . 0h. cos. ees ct ems eres aqua
2. Carapace nearly as broad as long; 4 to 7 pits, usually 5, in 20 mm. line; no

depression along back; nuchal, from side to side, 0.64 the width of the shell... wintaénsis
3. Carapace nearly as wide as long; a conspicuous depression along the back; length

of nuchal 0.80 of width of shell; with a smooth band in front........... Scutumantiquum
4. Costal bones thin; on proximal ends of costals, 2 pits in 10 mm.; on distal ends,

3 or 4; some ridges crossing the costals more conspicuous than others........ concentrica
5. Carapace nearly as broad as long; nuchal not half as wide as carapace; sculp-

ture‘of median coarseness, 3 pitsim TO MM... oi. cia eG os eee eee cases francisce
6. Carapace broader than long; nuchal nearly 0.6 the width of the carapace;

sculpture coarse and irregular, on central portions from 2 to 5 pits in 20 mm. salebrosa

7. Carapace about as broad as long; the bones thin; nuchal concave in front, its

length nearly 0.7 the width of the carapace; a smooth band along its fronts

Sculpture coarse, abouts) pits) imlOr mii ING, sise n.te stele feta gs cet ete exquisita
8. Carapace nearly as broad as long; rounded in front and behind; nuchal a little

more than half the width of the carapace; on proximal ends of costals, 3 pits

in 15 mm., on neurals and on distal ends of costals 5 or 6 pits in 15 mm. line. . mira
g. Known only from skull, which resembles that of 4. ferox; crushing surfaces of

upper jaw broad..... : tritor
to. Carapace nearly as broad as long; auéhall not one-half thie width ofthe carapace;

sculpture coarse, 3 or 4 pits in 20° mms TIN. .aics os cee se eee e ewes vee ee: egregia

A°. Uinta species:
1. Carapace broadly oval; nuchal 0.65 the width of the carapace; sculpture coarse,
MOK 2) IES MUTI LORIE Me Mit ctere: ees Reps etcatiayshao spatena acaVereraseusesiesstslginegs Soars erecta =< crassa
A®, Miocene species:
1. Costals thick and heavy; crost by narrow, sharp ridges, like those of a fle,
Omiya DOUGs INI cals eayeateasss stew cla tee oe wits: oS elelsiele weelece le Metis ei? sald us aes + lima
2. Costals not so thick; ridges closer together than in/1ma and curving across costal butet
3. Pits of costals closely placed, irregular in size and remarkably deep...........- cellulosa

512 FOSSIL TURTLES OF NORTH AMERICA.

Amyda? prisca Leidy.
Plate 97, figs. 2-6.
Trionyx prise us, Lery, Proc. Acad. Nat. Sci. Phila. 1851, p. 329; Smithson. Cont. Knowl., xiv, 1869,
art. Vi, pp- 113, 120, plate xviii, fig. g.—Copr, Cook’s Geol. N. J., 1868, (1869), p. 7355 Proc. Acad.

Nat. Sci. Phila. 1869, p. 12; Trans. Amer. Philos. Soc., XIv, 1860, pp: 15251533 Vert-1Cret:

Form. West, 1875, p. 260.—Maack, Palewontogr., XVIII, 1869, p- 281.—Hay, Bibliog. and Cat.

Foss. Vert. N. A., 1902, p. 454.

The original description of this species given by Dr. Leidy was exceedingly brief, present-
ing merely the thickness of the fragment of costal plate on which the species was founded,
and the statement that it was derived from the Cretaceous greensand of New Jersey.
Cope’s first mention of it, cited above, gives only the name; the second a description included
in two lines; the third, the name and the information that it came from the greensand of New
Jersey; the fourth, that it was derived from the greensand No. 4, by which he meant the
equivalent of the Pierre beds of the West.

Maack merely refers to the species and says that it was the only form of Trionyx then
known from the Cretaceous.

In 1869 Dr. Leidy, as cited above, gave a detailed description and a figure of a character-
istic specimen. This specimen must be regarded as the type. It was found in the marl on the
farm of G. C. Schenck, in Monmouth County, New Jersey, and was sent to Dr. Leidy by
Professor Cook, then state geologist of that state. This type is now in the state collection at
Rutgers College, New Brunswick, New Jersey, where it has been examined by the writer.
Leidy’ s figure. of the specimen is reverst, but otherwise correct. The pits are abruptly
sunken and the ridges are flat. Pits and ridges are both smaller as the free border is approacht.
In the middle of the length of the fragment there are 4 ridges in a line 16 mm. long.

Professor Cope states (Trans. Amer. Philos. Soc., X1v, p. 152) that the costal plate men-
tioned by Leidy as coming from the greensand of Baie County, New Jersey, and now
in the collection of the Academy at Philadelphia, belongs to A. halophila (Cope).

In the Cope collection of reptiles at the American Museum of Natural History there are
about a dozen fragments of the carapace, 2 or 3 of the plastron, the distal end of the left
humerus, and a posterior dorsal vertebral centrum. These specimens are credited to Dr. C.
Schenck, Marlboro, Monmouth County, New Jersey : probably the collector of Leidy’s
specimens. The number of the lot 1s 2401, and it is probable that it represents more than one
individual. These fragments were identified and labeled by Cope as Trionyx priscus. Figures
of some of these parts are here presented. Fig. 2, plate 97, represents the upper end of a
costal plate, the portion in immediate contact with the neural plate being broken off. The
width at the middle of the piece is 28 mm.; the thickness at the sutural border is 7 mm.; and
that thru the middle of the width is 8 mm. Fig. 3 of the same plate shows the distal end of a
costal bone, but no sutural edge is retained. The thickness near one sutural border is 7 mm.,
while thru the elevation produced by the rib the thickness is 11 mm. The mb projected
beyond the border of the costal plate, but how far can not be determined. The free edge of
the costal plate is abruptly rounded off in section. The fragment resembles greatly the border
portion figured by Leidy, and this author’s figure shows that the rib projected nearly 20 mm.
beyond sie costal plate. Leidy regarded ae costal which he figured as belonging to the left
side, but it seems rather to belong to the right. Fig. 4 of the plate referred to appears to be a
portion of the nuchal; but if so, this fragment did not extend to the midline nor show the
distal end of the bone. It indicates that there was a median excavation in the front of the
carapace, and a fontanel between the nuchal and the first costal plate. The bone is only 5 mm.
thick, while in front of the sculptured surface there is a smooth band. Fig. 5 of the plate
represents what appears to be the distal end of the hindermost costal plate of the right side.
The sutural border is present in front. The projecting rib is broken off just after leaving the
plate. The bone is 8 mm. thick and the free edge is cut off rather abruptly in section. Fig. 6
is a portion of one costal, probably from the middle of the length. The shorter of the two
longer borders shows the suture.

The two fragments of the plastron afford but little light regarding its structure. It
appears to have been 11 mm. thick where the hyoplastron and hypoplastron are constricted
between the legs of the animal.

TRIONYCHID:. 5 13

The sculpture of the carapace is coarse, and consists of deep pits of rather regular size,
surrounded by walls which are as wide as the pits themselves. The figures of plate 97 show
the general character of the ornamentation. The ridges which run across the costal plates are
strongly developt, while the connecting ridges are less prominent. There are four rows of pits
in about 15 mm. The sides of the pits rise more abruptly and the summits of the ridges are
broader and more rounded than in 4. halophila. On the proximal ends of the costal plates,
as shown by fig. 2, plate 97, the pits are arranged irregularly and vary much in size.

The pits of the fragments of the plastron are smaller than those of the carapace and not
so deep.

Until more of the carapace of this species shall have been secured, we shall be uncertain
as to its generic position.

Amyda? halophila (Cope).

Plate 96, figs. 4, 5.

Trionyx halophilus, Core, Proc. Acad. Nat. Sci. Phila. 1869, p. 12; Cook’s Report Geol. New Jersey,
1868 (1869), Append. 8, p. 735; Trans. Amer. Philos. Soc., xtv, 1869, p. 151, plate vu, fig. 155
Vert. Cret. Form. West, 1875, p- 261.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.

This species is said by Professor Cope to have been founded on numerous portions of the
carapace and plastron, some from near Summit Bridge, New Castle County, Delaware, and
some from Camden County, New Jersey. Whether or not these represented more than two
individuals we are not informed. In the Cope collection of reptiles in the American Museum
of Natural History there is a lot of bones, No. 1476, consisting of about 35 fragments of
costals, neurals, and at least 1 piece of the plastron. With these is found Cope’s label, as
follows: “Trionyx halophilus Cope. Type spec. Pits of Benj. Biggs, Summit Bridge, New
Castle County, Del., 1867.” In George H. Cook’s Geology of New Jersey, p. 734, Cope
states that in New Jersey this species comes from the lower marl bed of the Cretaceous.

It is dificult to determine what meaning to attach to Cope’s use of the terms “Nos ts.
“No. 2,” etc., in his table of measurements on page 152, of the Transactions American Philo-
sophical Society, as cited above. Tt may mean that he had portions of 5 individuals, which ts
the more probable conclusion. He speaks of having one costal plate which retained a portion
of the head of one rib, and in the measurements he mentions it as “costal plate No. 1.” This
fragment is yet in the collection, and is the one hgured by him; but it is not the first costal.
His ‘‘centrum vertebra No. 2” is also present, but the shortness of the neural plate attacht to
it, only 27 mm., appears to indicate that it is one of the posterior neurals.

This species was a rather large one, the length of the carapace of the individual, or indi-
viduals, represented by the remains before us, having probably been about 275 mm. The
larger fragments of costal plates indicate that the carapace was considerably archt from side
to side. The shell was quite thick and heavy; and the ribs stood out prominently on the under
side of the distal ends of the costal plates. The thickness at the sutural border, at the outer
end of one costal is 8 mm., while thru the rib it is 15 mm. The width of the costal at the
outer end was at least 56 mm. On plate 96, fig. 4, 1s represented of the natural size a neural
plate and a portion of a costal which belonged together. They are the same bones that Cope
has figured. The greatest length of the neural 1s 37 mm.,; the greatest width, 35 mm.,; the
thickness, 8 mm. The length of the fragment of costal is 60 mm.; its width, 33 mm.,; its thick-
ness, at the costal margin, 7 mm.; at the middle of the width, 9 mm. The inner surface dis-
plays the base of the rib-head. Cope states that his figure is half the natural size but, while
the length of the figure of the piece of costal is slightly more than half the size of the original,
the dimensions of the other portions are three-fifths of their natural size. Fig. 5 of plate 96
represents a portion from the middle of the length of a costal plate. The right and left sides
of the figure are the sutural borders.

The neural plate which surmounts the centrum spoken of by Cope as “No. 2 ” is damaged
somewhat, but it has had a length, in the midline, of 25 mm. and a width of 28 mm. The pos-
terior border is convex, the anterior concave.

The slight evidence afforded by one costal indicates that the free border was rounded
off in section. The rib projected somewhat beyond the edge of the plate.

33

514 FOSSIL TURTLES OF NORTH AMERICA.

The sculpture of this species is peculiar. It consists of rather large pits of quite regular
size and form. ‘They are rather deep, and from the bottom of each the surface rises gradually
to the top of the wall surrounding them, thus being bowl-shaped. In 4. prisca (Leidy) and
some other species, the wall Tonal the pit is more abrupt. Usually three pits occupy a line of
15mm. On the small portion of the plastron referred to, the pits are only about half as large
as those of the carapace, and are much shallower.

Among the fragments supposed to belong to this species 1s one which seems to have formed
a portion of the nuchal. If this identification is correct, this bone was rather thin where it
joined the first neural and first costals, but very thick, 11 mm., near the anterior border. The
free border was rounded in transverse section. At the midline this bone was only about 22 mm.
wide fore and aft, but it widened rapidly, being 38 mm. wide at a distance of about 40 mm.
from the midline. Thus the carapace appears to have been deeply and broadly excavated in
front. There is present a piece of some portion of the plastron. It is probably the bone which
Cope regarded as a part of the xiphiplastron. It has a thickness of 13 mm.

There is in the Philadelphia Academy’s collection a fragment of a costal plate which is to
be referred to this species. It was found at Camden, New Jersey. This fragment is 38 mm.
wide and represents about half the width of the costal. The thickness at the sutural border
is 10mm.; thru the ridge formed by the mb, 12 mm. There are 4 pits in a line 20 mm. long.

Cope thought that this and some of the other species of Trionychide were inhabitants
of the sea, and “he refers to a statement of Du Chaillu to the effect that Amyda triunguis had
been found at sea. The fact may be mentioned that there is in the American Museum of
Natural History a specimen of Amyda sinensis (Wi iegm.) which was captured in 1902, by Mr.
N. G. Buxton in Vladovostock Harbor, Siberia.

Amyda? pennata (Cope).
Plate 96, fig. 6.

Trionyx pennatus, Cork, Proc. Acad. Nat. Sci. Phila. 1869, p. 12; Cook’s Report on Geol. New Jersey,
Append. B, 1868 (1869), p. 734; Trans. Amer. Philos. Soc., x1v, 1869, pp. 151, 152, plate vii, fig.
13.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.

As in the case of too many of our fossil tortoises, our knowledge of this species is meager.
The species was based on a portion of the distal end of a costal bone, which was found in the
upper, or Eocene, bed of greensand, probably near Squankum, Monmouth County, New
Jersey, by Mr. O. B. Kinne. The specimen is now a part of the Cope collection of reptiles
in the American Museum of Natural History, and bears the number 1165. Cope, as cited,
hgured the type half the natural size. On plate g6, fig. 6, of the present work, it is repre-
sented of the natural size.

The fragment is supposed to include a little more than two-thirds the width of the distal
end of the costal, unless the rib lay nearer one sutural border than to the other. The costal
had, therefore, probably a width of about 60 mm. On the left of the bone, 47 mm. of the
sutural border is shown. At the proximal end of this border, the thickness is 7mm. At the
distal end it is 10 mm. Where the rib left the costal plate, the thickness is 13 mm. The free
border of the costal is cut off at a right angle with the upper surface.

The sculpture is of a coarse pattern. The ridges are broad and rounded, but the diameter
is usually less than that of the intervening furrows. In the type, the ridges run from the sutural
border of the bone inward and somew hati toward the distal end, and this arrangement evidently
suggested the name pennatus. Soon there appear connecting ridges and the furrows become
broken up into large and small pits. Near the border there are 2 furrows in 10 mm. Many of
the pits in the median portion of the costal are of less diameter than the surrounding walls.

Besides the type, there 1s now in the American Museum a fragment of a costal, No. 2221,
which belongs to this species. The bone shows 67 mm. of one sutural border and 8 mm. of the
one opposite. The width of the bone was 44 mm. The thickness of the sutural border at one
end is 7 mm.; at the other, g mm.; thru the rib, 12 mm. In this fragment the principal
ridges of the ornamentation run at nearly right angles with the sutural borders, while the pits
are very irregular in form and size.

At what Metals this specimen was collected there is no information; but it is very cer-
tain that it was obtained in the greensand of New Jersey.

TRIONYCHID~. 51

Al

Amyda? virginiana (Clark).
Plate 96, figs. 7, 8; text-figs. 670, 671.
Trionyx virginianus, CLARK, Johns Hopkins Univ. Bull., xv, 1895, p. 4; Bull. No. 141, U. S. Geol.
Sury., 1896, p. 59, plate viii, figs. 1a, 1b.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1g02, P- 4553—
Case, Maryland Geol. Sury., Eocene, 1go1, p. 97, plate xi, figs. I, 2.

All the known specimens of the present species were found at Aquia Creek, Virginia, in
Eocene deposits belonging to the Aquia Creek stage. The type fragments consist of a portion
of the distal end of a costal plate and of what appears to be the proximal end of another costal,
but which is possibly the outer end of the left hypoplastron.

The first-mentioned fragment represents
about half of the width of the costal. Figure
670 shows a section along the broken edge,
the distal end being toward the right. At the
proximal end the fragment is 17 mm. thick.
‘Toward the distal end this increases to 26 mm.,
then drops off suddenly to half the latter
thickness, then runs out to a thin edge. At the
q j O71. sutural border the thickness is slightly greater

: than at opposite points on the broken border.
This shows that there is no ridge produced by
the rib. The sculpture (plate 96, fig. 7) con-
sists of ridges and grooves placed at right angles

670. Section parallel with intercostal suture. with the sutural border. There area few ridges

71. Section at right angle with intercostal suture. : 2 e i “5
8 : crossing the grooves, breaking them up into
circular and elongated pits. Five pits and as many ridges are found in a line 22 mm. long.
Toward the line where the thickness is suddenly reduced the sculpture becomes obscure.
There is no smooth band along the sutural border.

The pits of this costal have the same size as in 4. pennata (Cope), of the Eocene of New
Jersey. However, in the latter the pits are arranged in rows that run from the sutural edges
toward the middle of the bone and at the same time toward the distal end. In /. pennata the
rib produces a decided thickening on the under side of the distal end of the costal.

The second piece (plate 96, fig. 8) of the type of 4. virginiana (Clark, fig. 1b) has a
thickness of 13 mm. at the distal end of the bone, increasing toward the other end to 15 mm.
Fig. 671 is a section across this bone. From the sutural border the bone increases to 22 mm.
thickness, an increase due to the presence of the rb on the under side of the bone. This costal
plate appears to have been about 80 mm. wide. An objection to regarding this fragment as
the outer end of the left hypoplastron is the fact that the ridge runs parallel with the sutural
border, instead of approaching it in one direction.

The sculpture of this fragment differs from that of the other in having the ridges con-
siderably broken up and quite irregular in direction. The pits are slightly larger, there being
5 of them in a line 25 mm. long. Along the sutural border there is a band 15 mm. wide which
is markt only by striations at right angles with the sutural edge. It is possible that in these two
fragments we have two distinct species.

Fics. 670 AND 671.—Am yda? virginiana. Sections
Ei v1
y

of costal bones of type. 4

Amyda? cariosa (Cope).
Plate 86, figs. 9, 10.

Trionyx cartosus, Cork, Syst. Catalogue Vert. Eocene, New Mexico, 1875, p. 35; Ann. Rept. Chief of
Engineers, 1875, p. 1025 (of separata, p. 95); Wheeler’s Surv. W. 1ooth Merid., 1877, p. 44, plate
xxvi, figs. 5-10; Vert. Tert. Form. West, 1884, p. 118.—Hay, Bibliog. and Cat. Foss. Vert. N. A.,
1902, p. 453.

The type specimens of this species are in the U. S. National Museum at Washington, and
have the catalog number 2575. Those which Cope figured consist of fragments of costal
bones, 1 neural, and a supposed xiphiplastral. Cope mentions also a hypoplastral as being
among his materials. The species is characterized by the coarse sculpture, the thickness of
the bones, and the longitudinal grooving of the margins of the carapace. The type was found
in the Wasatch beds of New Mexico, by Professor Cope, in 1874, along the Gallinas River.

516 FOSSIL TURTLES OF NORTH AMERICA.

As regards the thickness, Cope states that one costal was 7 mm. thick at the proximal end,
and that others were 11 mm. and 12 mm. thick at the middle of the length and at the distal
ends. At the free margins of the costals the upper layer of bone projected far beyond the lower
layers, causing, as Cope states, a deep longitudinal grooving of the free border of the carapace.
The costals had a width of about 45 mm. at the proximal end and of about 60 mm. at the
distal end. In Cope’s figures the width of the ndges is exaggerated and the pits are made to
appear too abruptly sunken.

The figures publisht by Cope show that there are on the proximal ends of the costals
deeply imprest and irregularly arranged pits, of which there are four or five in a line 20 mm.
long. Along the sutural borders of each of the costals there is a smooth strip. More distally
the pits arrange themselves in irregular rows, and sometimes coalesce to form furrows, which
run parallel with the margin of the carapace. Of these there are about three in 20 mm. In
Cope’s fgure 7 the ridges and furrows are not represented with enough distinctness. On the
neurals there was a honeycomb of pits similar to those on the adjacent ends of the costals.

Cope says that the hypoplastron in his possession presented a rather irregular reticulate
sculpture medially. The element fgured as a probable xiphiplastron had a "patch of large
pits; but this bone is really the left extremity of the nuchal. The figure is inverted. The right
extremity of the nuchal is present likewise.

Fig. g, plate 86, reproduced from Cope, gives a view, natural size, of a portion of a neural
bone, while fig. 10 of same plate shows a fragment of a costal plate.

A. radula has a style of ornamentation quite similar to that of the present species; but
the shell is thinner, and the free margins are beveled off, instead of having the upper layer of
bone overhanging the lower layers.

Amyda? ventricosa (Cope).
Plate 98, figs. 1-6.

Trionyx ventricosus, Corr, Extinct Vert. New Mexico, in Wheeler’s Sury. W. rooth Merid., tv, 1877,
p- 45; plate Ixiv, figs. 7-13; Vert. Tert. Form. West, 1884, pp. 118, 188.—Hay, Bibliog. and
Cat. Foss. Vert. N. A., 1902, p. 455.

This species is represented by somewhat more than 25 fragments, which Cope states belong
to 3 individuals. Of these fragments, 7 are fgured in Cope’s work in the Wheeler Survey, as
cited above. All these specimens belong to the U.S. National Museum and bear the number
1112. Of the pieces hgured by Cope, all are present, except the one which furnisht fig. 10 of
the plate cited. New figures of these are here furnisht, except of the missing fragment.

This species was ee by Cope in the year 1874, in the Wasatch deposits of Ric Arriba
County, New Mexico.

Fig. 1 of plate 98 (Cope’s fig. 13) represents the distal end of the left hypoplastron. This
bone indicates that the width of the hypoplastron at the narrowest portion was 20 mm., and
that the various dimensions of at least the distal end of the bone were about as they are in
Platypeltis sprntfera. Cope states that the ‘‘twin gomphosial processes’’ were short and stout
but these are not figured, and probably were not present on any of the specimens when found.
The processes neferred to separated from each other before they left the edge of the “‘cal-
losities,” and poe were probably short. The thickness of the bone where these processes
part is 10 mm.; at the sutural edge for union with the hyoplastron the thickness is 7 mm. The
ornamentation consists of narrow ridges which, near the free border of the bone, curve around
mostly parallel with these free borders; elsew here, they are irregular in their course. These
ridges are frequently connected by cross-ridges, and the intery ening spaces form pits and short
furrows wider than the ridges, Usually there are 2 or 3 pits in a space of about 5 mm.

Fig. 2 of plate 98 (hg. 12 of Cope) presents the same part as the previous figure, but of
another individual; but it offers no peculiar features. The same bone of a third individual
was larger, the thickness at the base of the twin processes being 14 mm. Fig. 3 of the same
plate (hg. 11 of Cope) is a fragment undetermined as to position, but probably belonging to
the plastron. It is about 7 mm. thick. The ridges and pits of the sculpture have no regular
arrangement, and the sculpture turns over the edge just below the outstanding process on one
side. Fig. 4, plate 98 (fg. 7 of Cope), shows the distal end of a costal plate, including the

TRIONYCHID. Sly

sutural edge on one side. At the junction of the sutural border with the free border, the thick-
ness is 10 mm. On the sutural border, at the end of the fragment toward the midline, the
thickness is reduced to 8 mm.; that is, this costal is thicker at the outer end than nearer the
midline. This and other fragments show that the free edge, on each side of the rib extension,
was cut off at nearly right angles with the sculptured surface. The sculpture came down close
to the distal ends of the costal plates. In some cases, but not all, there is a tendency for the
pits to arrange themselves, at the ends of the costals, somewhat parallel with the free border
of the bone.

Fig. 5 (fig. g of Cope) is a portion of the costal plate of a small individual. The width is
21 mm.; the thickness, only 4mm. Fig. 6 (fg. 8 of Cope) represents a fragment from prob-
ably the proximal end of a costal plate. Here the ornamentation consists of tubercles and
short, winding, and occasionally anastomosing, ridges, the pattern being somewhat coarser
than that of the plastron, there being two furrows or pits in about 5 mm. This is true of most
of the ornamentation of the carapace.

Amyda radula (Cope).

Plate 86, figs. 11, 12.

Trionyx radulus, CoPE, Systematic Cat. Vert. Eocene New Mexico, 1875, p. 35; Report on Geol.
N. W. N. Mex., in Appendix Ann. Rep. Chief of Engineers, 1875, p- 1015 (of separata, p. 95);
Wheeler’s Surv. W. tooth Merid., 1v, 1877, p. 45, plate xxvi, figs. 11-16.—Hay, Bibliog. and Cat.
Foss. Vert. N. A., 1902, p. 454-

In his original description Professor Cope characterized with great brevity this species of
Amyda. In his final report on his explorations in New Mexico, publisht in the fourth volume
of the Wheeler Survey, he gave some additional data and figures of some of the fragments on
which he had based the species. Even here, however, the description is limited to 10 lines of
print. The type specimens are now in the U. S. National Museum, at Washington, No. 2581.
They were collected in Wasatch deposits along the Gallinas River, New Mexico.

The figures given by Professor Cope make the summits of the ridges surrounding the pits
appear too broad. They are really narrow. From their summits the walls slope rapidly to the
bottoms of the pits, but not so abruptly as the figures indicate.

Cope’s fig. 11 represents the distal end of a costal. It has a thickness of 6 mm. In the
original of fig. 13 the free border, at the side of the extension of the rib, is cut off nearly square,
with a tendency of the upper layer to overhang. It will be observed that the sculpture of this
and of the costal of his fig. 14 (plate 86, fig. 11) comes down close to the free border of the bones.
Cope’s fig. 15 (plate 86, fig. 12) represents the middle of a costal. The sutural border is 4 mm.
thick. There are 6 pits ina line 20 mm. long. His fig. 16 1s that of a neural which has a thick-
ness of 6 mm.; and there are 5 pits in a line 15 mm. long. In these specimens the rib does
not stand out prominently on the under side of the costal.

Cope (Vert. Tert. Form. West, p. 119) identified with this species some portions of a
carapace found in the Bridger beds. This is here described under Amyda equa. For a
discussion of the relationships of the Wasatch species and the closely related 4. equa of the
Bridger see under the latter. It is greatly to be desired that additional materials of 4. radula
from the type locality shall soon be discovered and described.

A. radula has the sculpture similar to that of 4. cariosa. The two appear to be distin-
guisht by the greater thickness of the shell of the latter and the groove around its free margin.

Amyda equa sp. nov.
Plate 99, figs. 1-3; text-figs. 672, 673.

Trionyx radulus, Cope, Vert. Tert. Form. West, 1884, p. 119.
Amyda radulus, Hay, Amer. Geologist, XXXV, 1905, P- 3 30.

In the work above cited Professor Cope described and referred to his Trionyx radulus, of
the Wasatch of New Mexico, some remains of a trionychid which he found in the Bridger beds
of Wyoming. This Bridger individual now belongs to the American Museum of Natural
History and has the number 1052.

518 FOSSIL TURTLES OF NORTH AMERICA.

The nuchal is now 280 mm. long from side to side, and it was originally perhaps nearly
300mm. The fore-and-aft measurement in the midline is 45mm. It narrows toward the outer
ends. The anterior margin is nearly straight, and the bone is 12 mm. thick in most of its parts.
The anterior portion of the upper surface is occupied by a smooth band running from the one
extremity to the other. The outer ends of the costal plates are ornamented with pits and
furrows varying from 2 mm. in diameter near the free border to 5 mm. away from the border.
These are arranged mostly in rows parallel with the free border of the costal. Elsewhere the
pits are irregularly distributed.

In 1902, Dr. W. D. Matthew and Mr. Walter Granger, employed by the U.S. Geological
Survey, collected at Opal, Wyoming, two nearly complete carapaces of a trionychid which is
without doubt identical with Cope’s Bridger specimen. These deposits at Opal belong to the
lowest of the Bridger formation. Fig. 1, plate gg, shows the form of the better specimen. A
study of these and a specimen obtained for the American Museum of Natural History by
Messrs. Granger and Sinclair, in 1905, have convinct the writer that it is better to dara
them under a new name than to follow Cope’s example of assigning them to 4. radula,
species from the Wasatch.

This was an exceedingly large turtle, the length of the better carapace from Opal (plate
gg, fig. 1; text-fig. 672), along the midline, being 431 mm. and the width, greatest slightly
behind the middle of “aie length, 400 mm., not including the extension of the mbs beyond
the border of the shell. The carapace was only slightly convex, with a slight longitudinal
depression in the central portions. Anteriorly and posteriorly the carapace 1s Sneed with
the result of making it appear nearly square. The anterior border of the nuchal bone is
especially straight. Its size and appearance is almost identical with that of Cope’s Bridger
specimen and needs not to be described. Its distal ends lie above the contiguous parts of the
first costals; and there are no fontanels behind the nuchal. There are eight neural plates,

there being one which appears to belong to the eighth pair of neurals, an unusual thing. Of

these, the first is the largest and the eighth the smallest. A view of the figure will show that
there exist various irregularities in the forms of the neurals and costals. The first neural has
a length of 70 mm. and a width of 55 mm.; but the second specimen has a smaller neural,
the anterior end of which is not so broad as the posterior. The third neural of the large speci-
men is 50 mm. long and 39 mm. wide.

It will be observed that the seventh neural is heart-shaped and is brought forward so as to
lie partly between the costals of the sixth pair. The eighth neural is very small, 12 mm. long
and 19 mm. wide, and lies between the seventh costals. The eighth pair of costals measure
fore and aft, 44 mm. and from side to side, taken together, 136 mm. As an individual
peculiarity, the mght one is much the larger.

The borders ae the shell are beveled off obliquely at the sides, and nowhere does the super-
ficial layer overhang the ribs. Posteriorly the edge of the shell is rounded. The ribs project
beyond the shell Fn 30 mm., and these projecting ends are 25 mm. or more wide. At their
sutural borders-the costal plates are about 8 mm. thick.

As stated, there is a smooth band along the front of the nuchal bone. In the central
portions of the shell (plate gg, fg. 2) the ornamentation consists of large shallow pits sur-
rounded with a low narrow wall. Here the pits average about 5 mm. in diameter. As the
outer ends of the costals (same plate, fig. 3) are approacht, the pits become slightly smaller
and are arranged more or less in rows aiigh are parallel with the free border of the costal.
There may be as many as six pits in a line 20 mm. long. Here also the walls show a tendency
to break up into short ridges and tubercles. At the end of the plates there is a smooth band
from 18 to 25 mm. wide.

The vertebral column is strongly developt, as shown by fig. 673.

The second specimen, from Opal, is greatly like the one just described; but the greatest
width is slightly further forward and the hinder border is not so squarely truncated.

The specimen oa by Messrs. Granger and Sinclair at the mouth of Big Sandy
Creek, Wyoming, No. 3938 of the American Museum, resembles in essential particulars the
carapaces just decabed. but it appears even flatter than these. The length is 450 mm., the
breadth, 370 mm. The ribs projected beyond the free margins at least 30 mm. There is
a broad smooth band around the border, except in the rear. The ridges surrounding

TRIONYCHID#. 51g

the pits are broad and rounded. The pits measure as in the Opal specimens. Usually
there are 5 of them in a line 20 mm. long, but sometimes as many as 6 and again as few as 4.
The thickness of the second neural is 8 mm.; that of the sutural border of the second costal,
near the distal end, 7 mm.; that thru
the middle of the width of the same
oe costal, 13 mm.

Too little is known regarding Cope’s
Trionyx radulus, originally found in
the Wasatch beds of New Mexico, to
identify the Bridger specimens as the
same. Inthe Wasatch specimens the
smooth beveled band around the free
border is much narrower than in the
Bridger carapaces, the ridges of the
sculpturing coming down in places close
to the edge. In the case of the costal of
Cope’s fig. 13 the border near the pro-
jecting rib is cut off nearly square, with
a tendency of the upper layer to over-
hang. Nothing of this sort is seen in
any of the Bridger specimens. ‘The
costals and the neurals of the Bridger
forms appear to be thicker than those
of the type of 4. radula. The pits of
the latter, too, are smaller, there being
usually 6 1n a 20 mm. line, instead of 5.
The ribs of 4. radula do not stand out
so prominently on the under side of the
costals as they do in the specimens of

672. 673.

Fics. 672 AND 673.—A myda equa. Carapace of type. X 5.

A. equa.
672. Carapace. The specimen (plate 99) belonging

673. Vises of carapace, seen from below. c.p. 2, ¢-p. 8, mb-heads to the U. S. National Museum is taken
of second, and eighth costal plates; dor.v. 2, dorzv. 8, second

and eighth dorsal vertebra; nu.p., nuchal plate. as the type of A. equa.

Amyda uintaénsis (Leidy).
Plate 100, fig. 1; text-figs, 674, 675-

Trionyx uintaénsis, LEIDY, Proc. Acad. Nat. Sci. Phila. 1872, p. 267; Contrib. Ext. Vert. Fauna West.
Terrs., 1873, pp. 178, 342, plate xxix, fig. 1—Copr, Vert. Tert. Form. West. 1884, p. 118; Contrib.
Canad. Paleont., m1, 1891, p. 5—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454-

Amyda uintaénsis, Hay, Amer. Geologist, XXXv, 1905, p. 330.

The present species was based on a nearly complete carapace which was procured by Dr.
Leidy during his stay at Fort Bridger, in the year 1872. It was found, it is stated, in the
Bridger deposits, at Dry Creek, about 10 miles from Fort Bridger. It is probable that Little
Dry Creek was meant. If so, the level is B. This specimen belongs to the Academy of Natural
Sciences of Philadelphia, where the writer has been permitted
to study it. Originally little more than fragments were missing

Neural. Length. Width. . . : i ‘
from the right side, altho the left side was more damaged.

I 58 33 Now, however, it lacks the nuchal, which was originally present.
ss fe oe The specimen was kindly loaned to the writer with permission to
4 42 21 develop it further, and the result has been to find present most of
5 38 ) the plastron and some of the cervical vertebra.

sod at |

The carapace (fig. 674) is nearly as broad as long, broadest
somewhat behind the middle of the length, very slightly concave
in outline near the middle of the front, sinuous along the sides, and truncated behind. As
stated by Dr. Leidy, the carapace 1s about as convex as that of Platypeltis mutica. The length

520 FOSSIL TURTLES OF NORTH AMERICA.

is 420 mm. and the maximum width 394 mm. There are 8 pairs of costal plates and 6 neurals.
The nuchal extended from side to side 240 mm., and from front to back 56 mm. There is
no fontanel behind the nuchal. The neurals are, in general, rather narrow. The anterior two
are cofin-shaped, with the narrow end directed forward; the next two are nearly quadri-
lateral; the fifth cofin-shaped, with the broad end forward, while the sixth is cordate and
much reduced in size. The table presents the length and the maximum breadth of the neurals.

Of the costal plates, the first is broader than any of the others at the proximal end. The
second and the sixth are wider than any others at the distal end. The eighth is very short in all
directions. On account of the absence of the seventh and eighth nears and the reduction of
the sixth, the three hindermost pairs of costals meet in the midline. The rib of the fourth
right costal is present and projects beyond the border of the costal about 30 mm., being 28 mm.
wide at the base. Similar ribs have extended beyond the other costal plates, except the seventh
and the eighth. The costal plates are about 5 mm. thick.

The sculpture resembles that of 4 spideretes § guttatus but is coarser. There are from 4 to
7 pits in 20 mm., usually five, the pits being quite irregular in size and grouping. From their
summits the walls between the pits slope gradually to the bottoms of the latter.

Fics. 674 AND 675.—Amyda utntaénsis. Carapace and plastron of type. 3.

674. Carapace.
675. Plastron. cer.v.6, cer.v.8, sixth and eighth cervical vertebrae; ent, entoplastron; Lepi, rept, left and right
epiplastron; /.hyo, r-hyo, left and right hyoplastron; r.hypo, right hypoplastron.

The hyoplastron and the hypoplastron of the right side are complete, excepting that the
extremities of the external processes are broken away (plate 100, fig. 1; text-fig. 675). On
the left side there remains only a fragment of the hy oplastron, The right and the left branches
of the entoplastron are present, but fhic median and anterior part is missing. On the right side
is seen the anterior portion of the epiplastron, while the posterior part of the left epiplastron
lies close to the corresponding part of the entoplastron.

Judging from the fragments of these parts of the plastron that remain, the entoplastron
and the epiplastra were not especially different from those of Platy peltis ferox.

The hyoplastron is not co-ossified with the hypoplastron. The suture is directed inward
and forward, so that the anterior bone is narrower than the one behind it. The greater portion
of these bones is covered with a large callosity. This is ornamented on the external ends of
the bones with pits which resemble those of the carapace, but are not so large, there being
about five in a line 10 mm. long. The inner ends of the bones are smooth, but display a cloth-
like texture, produced by interwoven fibers of bone.

TRIONYCHIDZ. 521

The xiphiplastra are missing; but the notches in the right hypoplastron show that these
bones were articulated as in Platypeltis.

Three cervical vertebra were exposed in preparing the plastron, the sixth, seventh, and
eighth. All of these are turned backward, as if the head had been retracted within the shell.
The sixth has a length of 75 mm. The structure of these vertebra resembles that of P. jerox.

There is present also one ilium, but there appears to be nothing distinctive about it.

This species is very distinct from Aspideretes guttatus, but it might be very difficult
to distinguish small fragments of the two. The last- named species has a much more elongated
shell and a preneural, ee ecicie which readily distinguish it from Amyda uintaénsis. Rion
Amyda egregia, which has similar ornamentation, it is distinguisht by the different form of
the carapace and of the first neural; by the narrower neunale: and by the presence of 6
instead of 7, of them.

’

Amyda scutumantiquum Cope.
Plate 100, figs. 2-4; plate 1or, fig. 1; text-figs. 676, 677.

Trionyx scutumantiquum, Cope, 6th Ann. Report U. S. Geol. Surv. Terrs., i (087 3), p- 617; Amer.
Naturalist, xv1, 1882, p- 988, fig. 6; Vert. Tert. Form. West, 1884, pp. 118, 121,
I, ta.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.

Amyda acacananiauln Hay, Amer. Geologist, XxXv, 1905, p. 33

plate xvi, figs.

The type of this species consists of a nearly complete carapace and a considerable part of
the plastron, which were found in the Bridger beds, on Cottonwood Creek, in Wyoming. This
specimen is now in the American Museum of Natural History and has the number 1035.

Fics. 676 AND 677.—Amyda Scutumantiquum.

676. Carapace.
677. Plastron. Restored mostly from left half,
partly from right.

Professor Cope also referred to the same species, with some doubt, fragments which had been
collected from the Wasatch deposits near Black Butte, Wyoming, and! from the same forma-
tion on Bear River. Where these Wasatch specimens now are the present writer does not
know.

On the page facing plate xvi of the Vertebrata of the Tertiary Formations of the West,
Professor Cope states dhat his figures of this species are reduced to one-fourth the size of nature;
but this is an error, the figures being almost exactly one-third the natural size.

This species attained a large size and possest a heavy shell. The length of the carapace
(plate 101, fig. 1; text-fig. 676) of the type is 430 mm., measuring from the anterior portion
of the nuchal. The width is very close to 400 mm. There was probably a broad but very

522 FOSSIL TURTLES OF NORTH AMERICA.

shallow sinus in the anterior border of the carapace. The rear is broadly rounded. The shell
was considerably archt from the lateral borders to beyond the middle of the costal plates, the
rise being about 82 mm. Along the middle of the back there is a rather deep depression.

The nuchal extended on each side of the midline at least 152 mm., and was 37 mm. wide
fore and aft, perhaps somewhat more at the midline. There was no fontanel between it and
the costals of the first pair and the first neural. Also there was no preneural. The first neural
is large, being 68 mm. long and 37 mm. wide posteriorly. The others diminish in size to the
seventh and last. The second and third are cothn-shaped, the next three nearly quadrilateral,
and the last heart-shaped. This last one is only 22 mm. long and wide, and it separates only
partly the seventh costals.

All the costals grow broader toward their outer ends, except the first and the last pairs.
Those of the eighth pair are united in the midline by their entire width, and by their free

borders they fern 125 mm. of the hinder margin of the shell. At their free ends the most of

the costals are beveled off to a sharp edge, except where the rib projects beyond the costal
plate. Posteriorly the edge of the carapace is more obtuse. Near their outer ends the costals
are about g mm. thick at the sutural border, and 12 mm. thru the rib. How far the ribs
extended beyond the borders of the costal plates can not now be determined. Near the outer
ends of the costals the ribs occupy nearly half the width of the lower surface of the plates.

The nuchal had a broad, smooth band along its front, and this band has continued around
the greater part of the carapace, becoming very narrow behind. The sculpture (plate 100,
hgs. 3, 4) consists of the usual pits and ridges, the pits being rather deeply imprest and the
ridges abrupt. There are 2 or 3 pits in 10 mm. They are large and distinct in the median
depression (fig. 3) of the shell and on the middle of the length ah the costals, smaller on the
highest part of the carapace and on the outer ends (fg. 4) of ‘the costals. As the smooth band

is approacht, there is a tendency in the ridges to break up into tubercles. In figs. 3 and 4 of

plate 100 the upper edge of the figure is that directed toward the head of the animal.

Besides the carapace, Cope figured the outer ends of the hyoplastral and hypoplastral
Ais of the right side; but the same bones of the left side, nearly complete, are present (fg.
677) Lhe length of the suture joining them is 185 mm. The antero- posterior width of fhe
ears at the inner end was about go mm.; that of the narrowest part, across the
bridge, 35 mm. The antero-posterior extent of the inner border of the hypoplastron, exclusive
of the processes, was 95 mm., that of the narrowest part, 28 mm.

The thickness of the plastron at the inner ends, between the ridges of bone which ter-
minate in the digitations, is g mm. Thru the thickest part of the bridge the bone measures
15 mm.

The lower surface of the bone is ornamented, next to the outer end of the bridge, with
sharp ridges running antero-posteriorly. At the inner ends of the bones the surface is covered
with sharp tubercles. The remainder of this surface is merely roughened.

Amyda concentrica (Cope).

Plate 98, figs. 7-10.

Trionyx concentricus, Cope, Palwont. Bull. No. 1, 1872, p. 461; Proc. Amer. Philos. Soc., x11, 1873,
p. 461; U.S. Geol. Surv. Terrs., 1872 (1873), p. 617; Vert. Tert. Form. West, 1884, pp. 118, 120,
plate xvi, figs. 3-6.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.

Amyda concentricus, Hay, Amer. Geologist, XXXv, 1905, p. 336.

The type of this species consists of 4 fragments of costal plates, 3 of which belong to the
proximal ends, and 1 to the distal end, of their respective plates. These were found in the
Bridger deposits along Cottonwood Creek, Wyoming. In his earliest description Professor
Cope states that the remains of this species are common in the Bridger beds; but the present
writer knows of no specimens except the types. These are now in the American Museum
of Natural History and have the catalog number 1049.

The animal to which the type costals belonged was a small one, probably about 160 mm.
in length of carapace. The average width of the four costals is 19 mm. The thickness thru
the sutural borders is 3 mm.; thru the ribs it is 4 mm. The sculpture appears to furnish
characters for the identification of the species. On the proximal ends of the costals the pits

TRIONYCHID. 523

are usually large, there being 2 in a line 10 mm. long; but on the distal ends there may be 3
or 4 pits in this distance. These pits are arranged in somewhat irregular rows across the
costal bones. Some of the ridges separating these rows are higher and have sharper summits
than the others, these more conspicuous ridges running across the costals at a distance of
about 10 mm. apart. There may thus be from 1 to 4 rows of pits between each two of these
larger ridges.

Amyda francisce sp. nov.

Plates 102, 103; text-figs. 678, 679.

The fine specimen to which the name dAmyda francisce is given was collected by Mr.
Walter Granger, of the American Museum expedition of 1903, in the Bridger beds of Wyoming.
The exact locality is the eastern part of the Grizzly Buttes; the level is that known as B. The
specimen consists of the complete carapace and plastron; the seventh and eighth cervical
vertebra; both scapule and both coracoids; the pelvis, mostly hidden by the xiphiplastrals;
the proximal ends of both humeri; most of the right hind leg; the left femur; and most of
the left hind foot. The catalog number of the type is 5936.

Fics. 678 AnD 679.—Amyda francisce. ras

678. Carapace.
679. Plastron. ent, entoplastron; epr, epiplastron; /Ayo, hyoplastron;
hypo, hypoplastron; «ph, xiphiplastron.
In form the carapace (plate 102, text-fig. 678) is broadly elliptical, slightly truncated in
front and more decidedly truncated behind. Antero-posteriorly the carapace is slightly archt;
___ more strongly from side to side. The length in a straight line is
leereateet 315 mm.; the greatest width is 293 mm.
width. This species is referred to the genus 4myda because of the
presence of 8 pairs of costals and the absence of a preneural.
There are 7 neurals, of which the first is very large and the

Neurals. Length.

; A | )
2 Pa s | seventh much reduced. The anterior neural is considerably
i 42 29 | broader in front than behind. The table herewith presents the
ay Ba dimensions of the neurals. The four neurals succeeding the
6 28 17 first are wider behind than in front; the next two are wider in
7 27 7 front than behind.

~ a The nuchal has a fore-and-aft extent of 36 mm., and is about
130 mm. from side to side. The anterior border of the bone is occupied by a narrow, smooth
band. There appears to have been a small median fontanel between the nuchal and the
first neural.

The form and the relative proportions of the costal plates may be seen from the illustrations.
Their free borders are beveled off to an acute edge. The costal ribs are broad and they project

524 FOSSIL TURTLES OF NORTH AMERICA.

beyond the margin of the carapace about 30 mm. The thickness of the costals, measured at
the sutures, is abate 8 mm.; measured thru the ribs it is about 13 mm. The costals of the
seventh and the eighth pairs meet their fellows along the midline. Those of the eighth pair
are rather small.

The sculpture of the carapace is of median coarseness, there being about 3 pits in a line
1o mm. long. The pits are shallow and the rounded walls surrounding them are about as
wide as the pits. For some distance on each side of the midline the sculpture is nearly obsolete.

The plastron (fg. 679) incloses large median fontanels. The entoplastron and the epi-
plastra are slender bones, resembling those of Platypeltis spinifera. They possess no “‘cal-
losities.”” Nearly the whole surface oF the hyoplastra and the hypoplastra is furnisht with pits
and ridges, but these are not so coarse as those of the carapace, there being about five pits in a
line 10 mm. long. These are better developt on the outer ends of the Bones mentioned. The
median borders of these bones show a band consisting of a network of bony fibers. The
surfaces of the xiphiplastra present a similar interlacement of bony fibers.

The width of the bridge, where narrowest, is 51 mm., of which 26 mm. belong to the
hypoplastron. The median border of this bone possesses about ten digitations, of which the
two posterior are the largest and receive between them the inner process of the xiphiplastron.
The xiphiplastra are slender bones. They join each other by means of anterior two-tootht
processes and by broad posterior processes.

The bones belonging to the vertebral column, the shoulder and pelvic girdles, and the
limbs present no peculiarities.

This species resembles in some respects Amyda uintaénsis L eidy. It differs, however, in
being more elliptical in outline, in having the greatest width nearer the middle of the length,
7 neurals instead of 6, a differently formed first neural, a sculpture finer and of different
character, and a narrower plastral bridge, of which the hypoplastron is wider than the hyo-
plastron.

Dedicated to the writer’s daughter, Miss Frances Steele Hay.

Amyda salebrosa sp. nov.

Plate 104, fig. 1; text-fig. 680

Amyda salebrosa 1s based on a specimen which was collected by Mr. Walter Granger at
Dry Creek, i in southwestern Wyoming, June 30, 1904. The level at which it was found is (Ge
the middle of the Bridger deposits. Only the carapace is present, but this is practically com-
plete. It bears the number 3941 of the American Museum’s catalog.

The carapace (plate 104, fig. 1; text-fg. 680) was broad and probably rather flat. The
front margin is broadly rounded, the rear truncated. The length is 425 mm.; the greatest
width, 455 mm. Considering the great size of the carapace, it is ‘rather thin, being only 8 mm.
thick at the sutural borders, near one ends of the costals. Thru the ridges on fie underside
of the carapace, produced by the mbs, the thickness is 12 mm. The outer ends of the costals
are beveled off from above.

The nuchal has a lateral extent of 267 mm., and a fore-and-aft extent of 57 mm. Its whole
upper surface is pitted. Its outer ends overlap the outer anterior
angles of the first costals.

There are 7 neural plates, and these decrease in size from the
first to the last. The accompanying table gives the dimensions.

Neural. Length. Width.

I 67 38 The first neural is hexagonal, with the short sides consisting
z 55 » of the posterior and the two postero-lateral. The next two
- re ys neurals have the narrow end directed forward; the fourth is
5 37 21 nearly a parallelogram; the fifth and the sixth have the wider
: oF ms end in front; the seventh is pentagonal. The costals of the

| seventh pair join in the midline behind the seventh neural.

Those of the eighth pair met along the midline for a distance of
about 30 mm.; and each had a lateral extent of about 48 mm. The distal ends of the ribs pro-
ject but little beyond the borders of the disk. In younger specimens they will doubtless be
found to project a greater distance.

TRIONYCHID&. 525

The sculpture of this species presents a rather peculiar appearance, being coarse, irregular
and rough. ‘The pits are irregular in size, form, in height of bounding walls, and in disposition
with reference to each other. On the central portion of
the disk, including the greater part thereof, there are from
2 to 5 pits in a line 20 mm. long. Around the borders
of the carapace the pits are slightly smaller than else-
where, but often not well defined. Everywhere the walls
separating the pits are rather sharp and of varying height,
often being lifted up into sharp points, especially in the
angle formed by the junction of three pits.

This species is sufficiently different from all others
yet found. Aspideretes guttatus, A. ellipticus, and 4.
grangert all have much more elongated carapaces.
Amyda egregia has a thicker carapace, a smoother sculp-
ture, and a nuchal less extended laterally. In 4. scutum-
antiquum the carapace is more elongated, the nuchal 1s
furnisht with a smooth band, and the sculpture is every-
where finer. In 4. radula the nuchal is nearly straight
in front.

It is 4. uintaénsis to which the present species 1s
most closely related. It differs from the latter in having
the greatest width of the shell in front of the middle of
the length; in having a more convex front; and in
having larger and more irregular pits. The types of
the two species are of almost exactly the same length
and may therefore be more readily compared. A. scutumantiquum is longer than broad;
A. salebrosa is broader than long.

Fic. 680.—A myda salebrosa. Cara-
pace of type. $-

Amyda? exquisita sp. nov.

Text-figs. 681-683.

This species 1s represented in the American Museum of Natural History by portions of 2
individuals, which were collected in the Bridger beds of the Grizzly Buttes, Wyoming, by the
museum’s expedition of 1903. Of these specimens, number 5923 1s taken as the type. It con-
sists of the carapace (fragmentary but representing well the structure), the hyoplastra and
hypoplastra of both sides somewhat damaged, one cervical vertebra, portions of both humeri,
the left femur, portions of the pelvis, and various other leg and foot bones. Of the other
individual, No. 5943, there are present only the hyoplastron and the hypoplastron of the
right side.

This species is markt among the species of the genus found in the Bridger beds by the
thinness of the shell and the coarseness of the sculpture. The total length of the carapace
(fig. 681) was very close to 375 mm.; the greatest width almost the same. Evidently the out-
line, both in front and behind, was slightly concave; laterally it is sinuous. The disk was
filled out nearly to the ends of the ribs.

The thickness of the sutural border of the third costal plate, near the proximal end, ts
6 mm.; but thinner toward the distal end of the plate. Thru the rib, in the middle of the
width of the costal, the thickness amounts tog mm. The sutural border of the eighth costal
is 7 mm. thick.

The exact dimensions of the nuchal bone can not be determined, there remaining only 2
fragments; but evidently the lateral extent of the bone was close to 250 mm., and the fore-and-
aft extent, at the midline, very close to 50 mm. Fig. 682 represents a section of the bone along
the midline. The free border is reduced to a subacute edge. Seen from above, the nuchal
presents a smooth band along the anterior border. This is 13 mm. wide at the midline,
but increases to twice this width toward the distal ends. The maximum thickness of the bone
is about 13 mm.

From the materials at hand it can not be certainly determined whether there was a pre-
neural bone; but probably this was absent. There are 7 neurals, the dimensions of which are

526 FOSSIL TURTLES OF NORTH AMERICA.

given in the table below. Of these neurals, the anterior was probably about as wide in
front as behind. The next three have, as usual in the family, the narrower end directed for-
ward. The fifth has the anterior end only slightly narrower than the hinder end. The sixth
has the broader end in front. The seventh is heptagonal.

At the free border the costals are beveled off on the upper side.

681.

Fics. 681-68 3.—A myda? exquisita. Type.

681. Carapace. 4. Parts ruled with parallel lines are missing.
682. Antero-posterior median section of nuchal. 1. 683. Plastron. Xt.
On most portions of the carapace the sculpture, consisting of pits, is coarse. The bottoms
of the pits slope up to the summits of the rounded walls. The average diameter is about 5 mm.
On the hinder border of the nuchal the pits are smaller, about 5
ina line 20 mm. long. Those along the free border, too, have
this size. On the proximal two-thirds or more of the costals
there are usually 4 pits in a 20 mm. line. On the hinder third

Neural. Length. Width.

1 50 29 A

2 37 3 of the carapace they are still larger, 3 and sometimes only 2.5
3 35 30 in the line mentioned. Those on the anterior 4 or 5 neurals are
: ef very shallow.

6 30 21 The plastron (hg. 683) is remarkable for the narrowness of
7 21 21

the bridges and the depth of the notch between the outer proc-
ess of the hyoplastron and that of the hypoplastron. The
width of the bridge is only 47 mm.; in the paratype, No. 5943, an individual apparently as
large as the type, the width is only 39 mm. The size of the fontanel inclosed between the
outstanding processes of the plastral bones mentioned may be judged from the accompanying
figure. ‘There were also extensive fontanels along the midline.

TRIONYCHID. 52.7

The pits of the plastral bones are smaller than those of the carapace, about 7 in a 20 mm.
line. Toward the mesial border of the bones the pits become obsolete and there comes into
view a meshwork of bony fibers such as Cope found in his 4 xestus byssinus (Axestemys
byssina). here is, however, no reason for thinking that the present species is identical with
Cope’ Ss species just mentioned.

The cervical vertebra present appears to be the sixth. It has a length of 58 mm. An esti-
mate shows that the length of the neck was about 380 mm. The bone appears to be slenderer
than the corresponding bone of a specimen of Platypeltis spinifera.

The fragmentary bones belonging to the shoulder and pelvic girdles and to the limbs
furnish few ‘noteworthy data. The total length of the humerus is 125 mm. The shaft is
slenderer than that of 4 xeste mys byssina; the loses diameter of the former being 8 mm., that
of the latter 17 mm., while the length of the humerus of 4xestemys appears not to have been
much greater than shat of the present species.

This species is at once distinguisht from 4. salebrosa by the greater development of the
costals of the two hinder pairs ood by the greater width of most of the neurals. The greater
breadth of the carapace, the greater length of the nuchal from side to side, and the longer
eighth costals distinguish it from 4. egregra. Comparison with 4. concentrica is required,

5

Amyda mira sp. nov.

Plate 105, fig. 1; plate 106; text-figs. 684-686.

Under the above name 1s described a trionychid which was discovered by the American
Museum party of 1905, at Grizzly Buttes, Wyoming g, in level B, of the Bridger Eocene. The
specimen bears the number 6130. It furnishes the skull, without the lower jaw; the carapace
complete; and the plastron, excepting the entoplastron, the epiplastra, and a portion of the
left hyoplastron.

The carapace includes 8 pairs of costal plates and there is no preneural; hence the genus
Amyda is indicated. The carapace (plate 105, fig. 1) is about as wide as long, broadly
rounded behind, more sharply rounded in front, a of considerable convexity. The length
ae Sees in a straight line is 263 mm.; the extreme width is 252 mm.;

Neural. | Length. | Width. the height of the center is 62 mm. above the borders. On the
—= sides the free borders of the costals are beveled off; in front,
| the nuchal and the first costal are trimmed off at right angles

I 44 24

2 31 23 with the upper surfaces.

: os 2 The nuchal is 27 mm. wide, 134 mm. from extremity to
5 24 18 extremity, and 97 mm. from its union on the free border with
= hs the second costal to the same point on the other side. The

extremities of this bone are contained each between two plates
of the second costal.

There are 7 neurals, all except the first, the sixth, and the seventh being hexagonal, with
the broad end behind. The dimensions are given in the table.

Of the costals the sixth and the seventh meet their fellows at the midline. Those of the
seventh pair are well developt. They join along the midline a distance of 30 mm. and each has
a width along the free border of about 33 mm. The extremities of the various costals have a
thickness of 5 mm. at the sutural edges and of about 8 mm. thru the rib. The ribs are markt
off distinctly the full length of each costal plate. Those along the sides of the carapace project
about 20 mm. beyond the border of the disk, but that of the eighth costal projected about
40 mm.

The surface of the carapace is ornamented with pits and grooves and intervening ridges.
On the rear are 10 or 12 distinct longitudinal welts. The ridges are narrow, sometimes sharp.
The pits frequently coalesce, especially on the distal ends of the costals, to form grooves. These
show a tendency to run parallel with the axis of the animal. On the neurals the; pits are smaller
than on the costals, about 6 of them in a line 15 mm. long. On the proximal ends of the costals
there may be as few as 3 pits in the given line. On the distal ends of the costals there are
usually about § pits or grooves in the line mentioned.

528 FOSSIL TURTLES OF NORTH AMERICA.

The plastron (plate 106, fg. 1) has a breadth, from the extremity of the hyoplastral
processes of one side to those of the other, of about 310 mm. The outer fourth of the hyoplas-
: tron of each side has coalesct with
the corresponding hypoplastron. The
transverse extent of these bones,
along this suture, is 133 mm. Where
narrowest the bridges are 48 mm.
wide. The hyoplastron and hypo-
plastron have a close resemblance
to those of Platy peltis jerox. The
hypoplastron differs from that of the
species just named in havinga greater
number of digitations directed toward
the midline.

The xiphiplastrals are concave
along the outer border, whereas those
of P. ferox are convex. In the latter
species there is a single process which
meets the single process from its fel-
low bone; in 4. mira there is on the
left side a broad process which is
received between two slenderer pro-
cesses of the right side.

Nearly the whole inferior surface
of the hyoplastra, hypoplastra, and
the xiphiplastra is covered with a
sculptured layer of bone, the callos-
ities, as they are called in living tri-
Fics. 684-686.—Amyda mira. Skull of type. Xo0.9. onychid turtles. The pits and ridges
: are less strongly developt than on the
carapace. They are most distinct on
the outer ends of the hyoplastra and hypoplastra. Here there are about 5 pits in a 10 mm.
line. On the mesial halves of these bones the pits are very shallow. The sculpture on the
xiphiplastra is feebly exprest.

The skull (fig. 684-686) is beautifully preserved. It lacks the lower jaw, the occipital
condyle, the supraoccipital process and parts of the squamosal processes.

The approximate length of the skull, from the tip of the snout to the occipital condyle,
is 72 mm.; the greatest width, at the upper posterior border of the tympanic cavity, 1s 45 mm.
From the fronts of these cavities the sides of the skull converge to near the narrow and rounded
snout. The flexure of the skull behind the choane 1s remarkable, fully as great as in
A. cartilaginea, while the descent of the face is still more rapid than in the living species
just named.

The sutures between the bones are yet open, but no remarkable relations have thereby
been shown. The tympanic chambers are large, each diameter being 16 mm. The zygomatic
foss are small, only 14 mm. long. The orbits are unusually large, the horizontal diameter
being 16 mm. equal to that of specimen of Platy peltis ferox whose skull is 94 mm. long. The
vertical diameter is 13 mm. The interorbital space is only 4 mm. wide. Each diameter of the
nares is 10mm. The snout projects 20 mm. in front of the orbits.

The pterygoid portion of the palate has a width of 25 mm. The anterior portion of the
skull is remarkable for the depth of the groove in which the choanz are situated. This begins
at the posterior palatine foramina and extends forward to the premaxilla. It has a depth of 5
mm. and a width of 8 mm. The choane are placed well backward, the middle of the length of
each being opposite the middle of the orbits. Each is 10 mm. long. The triturating surfaces
of the upper jaws are 6 mm. wide opposite the choana, but they narrow gradually forward.

Altho the lower jaw is missing one of the ceratohyals is preserved. Most of the internal
skeleton is preserved, but it has not been cleared from the matrix.

684. Seen from above. 685. Lower aspect. 686. Right side.

TRIONYCHID. 529

This species resembles in some respects . 1. francisce. However, the carapace of the latter
is somewhat excavated at the midline in front, the rear is more truncated, and the ridges of
the sculpture have broad and rounded summits. The anterior border of the hyoplastron i is
very concave; that of 4. mura is gently sigmoid. Likewise, the mesial border of the hypo-
plastron of A. francisce has a greater Admber of digitations.

There are points of resenainaniee between 4. mira and Platypeltis he teroglypta. In the
latter, as in others of the genus, the eighth costals are w anting or only feebly dey elopt. The
form of P. heteroglypta is different from that of A. mira, the front of the carapace is more
rounded and the rear more truncated. The nuchal is relatively longer and there is an
unsculptured band along its front. It is observed, too, that the ribs on the underside of the
costals are broader in P. heteroglypta than in the subject of the present description. The width
of those of the second, third, and fourth costals of P. heteroglypta, taken near the distal end, is
24mm.each. In 4. mira, the rib of the second is 22 mm. wide; the third, 20 mm.; the fourth,
18 mm. P. heteroglypta was probably a flatter species, but the specimens are much crusht.

Amyda? tritor Hay.
Text-figs. 687-689.

Aspidonectes tritor, Hay, Science (2), XIX, 1904, p. 254.
Amyda? tritor, Hay, Amer. Geologist, xxxv, 1905, p. 336.

This species is based on a large and well-preserved skull which was collected by the
writer in the Bridger deposits, about 3 miles above the mouth of Cottonwood Creek, east of
Fort Bridger, Wyoming. The matrix in which the specimen was found is a calcareous and
argillaceous sandstone belonging to the base of the middle third of the Bridger beds. The
number of the skull, in the American Museum catalog, is 5913.

The total length of the skull (figs. 687-689) is 162 mm.; and it has therefore belonged to a
large animal. In the American Museum of Natural History there is a specimen of Platy-
peltis ferox, the carapace of which has a length of 265 mm. and whose skull has a length of 116
mm. If the skull and carapace of 4. tritor had the same ratio that obtains in these parts in
P. ferox, the carapace of the former would have had a length of about 370 mm. This is some-
what less than the length of the carapace of Leidy’s Trionyx uintaénsis, and considerably less
than that of the carapace of Cope’s 7. scutumantiquum. ‘The skull under consideration may
therefore have belonged to one or the other of these or to some other described species. For
the present it 1s necessary to give a distinct name to this skull and await further discoveries.

The following are the principal measurements of the skull:

Millimeters.
Length from snout to end of supraoccipital spine 162
Length from snout to end of occipital condyle 123
Width from outside to outside of quadrates........ . 9I
Width across pterygoids..... 47
Width of interorbital space. . a : 20

In general form the skull resembles that of Platypeltis ferox; but the width is somewhat
greater, the snout is shorter and less pointed, the interorbital space 1s broader, and the choanz
are more constricted. The facial angle is about the same in the fossil as in the living species,
the roof of the mouth being bent own about 25° below the plane of the pteryg moire: The
sutures between the various bones are more finely dentated than in P. ferox. The skull
appears not to have suffered distortion during fossilization.

The snout is broad and blunt. The vagal opening is 22 mm. wide and only 12 mm. high.
The co-ossified premaxillz are small, measuring from side to side only g mm. The external
surface of the maxilla is perpendicular, and the outline, seen from above, is slightly concave.
Seen in profile, the skull is nearly flat behind the orbits, whilst more anteriorly there is a gradual
curve to the end of the snout. In P. ferox there is an abrupt change of direction Reewe een the
hinder borders of the orbits.

The paroccipitals have about the same relative size and disposition as in P. jerox. The
portion of the quadrate exposed between the prootic and the squamosal appears to be some-
what narrower than in the living species mentioned,

34

530 FOSSIL TURTLES OF NORTH AMERICA.

On the lower surface of the skull (fig. 688) are to be noted the broad triturating surfaces
of the maxilla, each presenting about the same relative amount of surface as in P. ferox. The
transition between the triturating surface and the cutting-border of the jaw is rather abrupt.
The choanal fossa is likewise formed somewhat abruptly. In the midline in front of the
choanz may be seen the suture where the inner borders of the maxilla meet below the vomer.
A portion of the vomer is exposed in front of this suture. The anterior palatine foramen is
small, only 7 mm. long, while in the specimen of P. ferox referred to above, it is 11 mm. long.

Fics. 687-689.—A myda? tritor. Skull of type. X 3.

687. View of upper surface. 688. View of lower surface. 689. View of right side.

The choanz are relatively small, being constricted as in Amyda cartilaginea and A. sinensis,
and the constriction has been produced in the same manner in the fossil, as in living species.

The basioccipital bone is rather broad, occupying nearly one-third of the width of the
posterior part of the roof of the mouth, the lateral portions being formed by the pterygoids.
This region is slightly concave both transversely and longitudinally. The articular surface of
the quadrate is 20 mm. wide, from side to side, being relatively greater than in the case of P.
jerox. The squamosal processes, formed by the backward extension of the squamosal and the
paroccipital bones, are large and scroll-like.

TRIONYCHIDA. 531
Seen from the side the cutting-edge of the maxilla is convex from front to the hinder end.
The zygomatic arch has only elcrate width. The tympanic cavity did not extend so far
Rietaed into the squamosal as it does in P. ferox and P. spinifera.
Until we shall have secured the carapace of this species in association with the skull, we
must remain uncertain as to the genus to which it belongs.

Amyda egregia sp. nov.
Plate 107, figs. 1-3; text-fig. 691.

The type of this species is a complete carapace which was collected in 1895, by Mr. O. A.
Peterson, in charge of the American Museum expedition of that year. It was obtained from
the lower Washakie beds, south of Haystack Mountain, Wyoming. The number is 1186.

The shell ( (plate 107, fig. 1; text- fig. 691) is broad, rounded
l in front, truncate behind, ant moderately convex. The border

‘i | Hi : . :
Neural. | Length. | Width. is slightly emarginate on each side at the suture between the
i auchal and the fact costal plate; elsewhere gently repand. The
1 56 37 length of the carapace, in a straight line, is 356 mm.; the great-
2 44 3! est cadena is 334 mm.
| 3 38 31 ( ; - :
| fi 38 BG Sf neural plates there are seven present. The table gives
5 34 22 their dimensions. The first ee eee
30 19 ral is only 25 vid a
i a 28 neural is only 25 mm. wide eae

| at its hinder end.

J > ae The nuchal has a trans-
verse extent of 150 mm. and measures fore and aft 22 mm.
Its outer extremity overlaps the free end of the rib of the
first costal plate.

The shell of this species is quite thick and solid. The
thickness of the fifth costal plate, a little beyond the ols
of the length and at the sutural edge, is about 10 mm.; in
the ravadle of the width, where the rib hes, the Hicines
equals 15 mm.

The ribs do not appear to have projected much beyond
the margin of the carapace, apparently only about 30 mm.
At the margin the shell is beveled off rather abruptly, but
the sculptured layer nowhere projects beyond the deeper
layers of bone. On the front of the nuchal the bevel of
the margin becomes a broad shallow groove.

The sculpture of this species is very coarse. In the
central portions of the carapace (plate 107, fig. 2) it consists
of rather shallow pits separated by broad low ridges, the
whole forming a honeycomb structure. The ridges are
nearly as broad as the pits. About three pits, occasionally four, occupy a line 20 mm. long.
The pitting is coarsest on the hindermost costals, and here too the ridges become more
elevated. On the outer fourth of the costals (plate 107, fig. 3) the ridges and pits are arranged
in rows across the costals, the connecting ridges being ne conspicuous than those crossing
the plates. Near the margin the irregular honeytomb arrangement is again found. W here
the pits are in rows they are large aud the ridges conspicuous.

This species somewhat resembles i in its sculpture Aspideretes guttatus; but in the latter
species the ridges separating the pits are in nearly all cases narrower and sharper. The
sculpture is likewise not so coarse on corresponding parts of the shell. The two species are
greatly different in other characters.

Amyda uintaénsis (Leidy) likewise presents a similar coarse sculpture, but the ridges
intervening between the pits are narrow and sharp. Other characters clearly distinguish the
two species. The nuchal of 4. uintaénsis has a considerably greater transverse extension than
in A. egregra. The anterior border of the shell formed by the nuchal is more truncated. The
neural plates differ in form and proportion, and there are ‘only 6o0fthem. There are differences
in the last costals.

Fic. 691.—Amyda egregia. Cara-
pace of type. X 4.

FOSSIL TURTLES OF NORTH AMERICA.

wal
w
N

Amyda crassa sp. nov.
Plate 108; text-fig. 692.

This species is founded on a fragmentary carapace, No. 3887 of the American Museum of
Natural History. This was collected by that museum’s expedition of 1895, in the upper beds,
“horizon C,” of the Uinta deposits, in the region along White River, Utah. The parts present
include a considerable portion of the costals, a few of the neurals, and nearly the whole of the
nuchal. Most of the left second costal is missing, about the distal half of the right third,
7 portions of both costals of the fourth pair, and practically
ae all of those behind the third of the right side. There is also

at hand a portion of a plastral bone of another individual,
oo probably of the same species; and this is labeled “top of
/ B, Uinta.”
f : } \ In form the carapace (plate 108; text-fig. 692) is broadly
q oval, with the length exceeding the breadth, and with the
greatest width at the middle of the length. The length is
aK 475 mm.; the extreme width, 420 mm. The anterior
border is regularly rounded, while the hinder border is
ae rather truncated. The carapace was apparently only
e i a moderately convex. There were 8 pairs of costal plates
‘ and 7 neurals.
cena “\~ This species is remarkable for the thickness of the
; | bones of the carapace, and for the coarseness of the sculp-
+ ture, equaling and even surpassing in these respects any of
\ J the species of the Wasatch deposits. The usual thickness
eee ae of the costals is, near the sutural borders, 10 mm.; thru
‘ ee the middle of the width, 13 mm. The thickness of the outer
Or a ae tt end of the nuchal is 18 mm. The sculpture consists of
~ we | ridges and pits, usually very irregular in form and size and
_ Se arrangement. The largest pits may be 8 mm. across; but
there are commonly 2 in about 10 mm. The ridges sepa-
rating them may be as broad as the pits, but more often
they are narrower and rather sharp. Their elevation like-
wise varies greatly. On the proximal ends of the costals there is little or no regularity 1 in their
disposition, but toward the distal ends the pits and ridges are arranged in rows running across
the costals.

The nuchal bone of this species resembles that of 4. uintaénsis (Leidy), described and
figured in this author’s Contributions to the Extinct Vertebrata of the Western Territories,
p- 178, plate xxix, fig. 1. Its length from side to side is not far from 275 mm., while its fore-
and-aft extent is 58 mm. It is pointed at the outer ends. There were no fontanels between it
and the first neural and the first pair of costals. There is a shallow groove, about 1o mm.
wide, running along near the anterior border; and this border is beveled so that the upper sur-
face somewhat overhangs the lower.

The free borders of the two anterior costals and of the more posterior ones are rounded
off, but the intermediate ones are beveled. The first costal is very broad, about 77 mm. across
the middle. The succeeding ones up to and including the fifth are considerably narrower,
about 52 mm. The sixth is 47 mm. wide at the proximal end, while its distal end is about 80
mm. ‘The width of the seventh at the proximal end appears to have been about 36 mm.,
while the outer end, measured along the oblique free border, is 60 mm.

Only a few neurals are present, and none of these is complete. Nearly the whole of the
firstis present. [tis cofhn-shaped, and the front end is convex. The length was close to70 mm.;
the width of the anterior end, 36 mm.; that of the widest part, near fhe hinder end, 52 mm.
Of the forms and dimensions of the second, third, and fourth neurals, we can judge only
from the spaces which intervene between their contiguous costals when these are in place.
They were all smaller than the first, but of the same general form. The second, about whose
dimensions we can be most certain, had a length of 57 mm., and a width at the hinder and
wider end of 43 mm. The fifth neural is present only in part. Its length appears to have been

Fic. 692.—Amyda crassa. Cara-
pace of type. X¢.

TRIONYCHID. 533

44 mm. and its width close to 30 mm. It was probably only a little narrower at the anterior
end. It articulated with only the fifth costal. Most of the sixth neural is present. It was
parallelogrammic, 40mm. longand 32 mm. wide. It articulated with the hinder proximal angle
of the fifth costal, and the greater part of the proximal end of the sixth costal. The seventh
neural is partly present, and was probably about 25 mm. long and 34 mm. wide. It articulated
with the sixth and seventh costals on each side. It is not probable that there was an eighth
neural. Consequently, the seventh costals joined in the midline, as did also the eighth costals.

The portion of the plastral bone already referred to is identified as the outer end of the
right hypoplastron. Its catalog number is 3886. It includes the two digitations at the external
angle and the remainder of the bone inward somewhat beyond the narrowest part of the bridge.
The width, where narrowest, is 32 mm. The length of the longest digitation is 65mm. The
thickness at the free border equals 12 mm.; that thru the narrowest part of the bone, 23
mm. The distal free border is beveled off. The lower surface of the bone is furnisht with a
sculpture consisting of coarse pits and ridges, arranged, where well preserved, in rows parallel
with the outer border.

Amyda crassa appears to resemble somewhat 4. uintaénsis (Leidy), but it differs in various
ways. The latter species has its greatest breadth somewhat behind the middle of the length.
The nuchal bone of 4. crassa is longer, from side to side, in proportion to its width. The
neurals of Leidy’s species are narrower and with more nearly parallel sides. Moreover, there
were only 6 neurals, whereas, in A. crassa, there are 7.

Two costal bones, No. 1021 of the American Museum, found in 1895, near the top of
division B of the Uinta beds, belong apparently to this species. They indicate a greater con-
vexity of the carapace than is shown by the type.

Amyda? lima Cope.
Plate 98, fig. 11.

Trionyx lima, Cope, Proc. Acad. Nat. Sci. Phila. 1869, p. 12; Amer. Naturalist, 111, 1869, p. 90; Trans.

Amer. Philos. Soc., x1v, 1869, pp. 151, 153, plate vii, fig. 14; Proc. Amer. Philos. Soc., x1v, 1875,

p. 363.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.

The original description of this species is exceedingly brief, and was not accompanied by
a figure. A sufficient description and figure were, however, publisht in the same year. The
type and only known specimen, now in the American Museum of Natural History, is a frag-
ment of the distal end of one costal. It is remarkable for its heavy construction. The bone
was somewhat decayed and eroded; and it is not certain that we have present either of the
sutural borders. It is probable, however, that we have nearly the original width of the bone.
The present width is 47 mm. The thickness, which includes the rib, is 18 mm. Even near the
supposed sutural border the thickness is 14mm. The rib probably projected somewhat, but
how much can not be determined. At the free border the bone is cut off at nearly right angles
with the upper surface. The under surface stands out somewhat farther than the upper, so
that there is a shallow groove occupying the free border.

As Cope suggests, the most conspicuous character of this species is found in its sculpture.
This consists of rather high and narrow ridges which run across the bone, and separate grooves
which are somewhat wider than the ridges themselves. The summits of the ridges are uneven
and are sometimes cut quite to the bottom. There are remarkably few connecting ridges,
but occasionally a ridge is found to divide; or it may suddenly come to an end. The distance
across two grooves is about 7 mm. On the proximal end of the fragment the ridges are some-
what irregular in their course; at the distal end they are narrow and much interrupted.

In the American Naturalist, Professor Cope remarks concerning this species:

The Trionyx of our Miocene (7. /ima Cope) was large and rough, with narrow ridges. Its remains
occur with dolphins and porpoises, but it may have been floated or washed from the mouth of a
freshwater stream into such strange company.

There are, however, reasons for believing that some species of the Trionychide are not
averse to living in salt water.

This species was found in the Miocene marl, in Cumberland County, New Jersey.

With so little of the skeleton of this species for examination, it 1s impossible to determine
with any degree of certainty the genus to which it belongs.

4 FOSSIL TURTLES OF NORTH AMERICA.

wn
ww

Amyda? buiei (Cope).
Plate 98, fig. 1

Trionyx butet, Cope, Trans. Amer. Philos. Soc., xv, 1869, pp. 151, 153; Kerr’s Report Geol. N. Caro-
lina, 1, Append. B, 1875, p. 34.—Hay, Bibhiog. and Cat. Foss. Vert. N. A., 1902, p. 453-

In the original description of this species Professor Cope stated that it was represented by
numerous costal bones in a more or less fragmentary condition. Of these fragments only a
single one has been recognized in the Cope Collection in the American Museum of Natural
History. A figure of this is presented on plate 98. The fragment belongs to the distal end
of a costal plate, and extends from one sutural margin to about the middle of the width of the
plate. The thickness is slightly less than 5 mm. at the sutural border, and about 6 mm.
thru the rib. The distal end of this plate was probably about 30 mm. wide.

The sculpture consists of rather low and narrow ridges, which run in a curved course
across the bone. Some distance from the sutural border the ridges begin to be connected by
cross-ridges, so that the intervening furrows become broken up into pits of irregular sizes.
Two of the furrows occupy a space of about 5 mm. ‘The furrows and pits are considerably
broader than the ridges themselves. It is not unlikely that the proximal ends of the costals
will have the pitting extended to the sutural borders

The little matrix which yet adheres to this bone is very green.

From the Miocene near Mount Olive, Duplin County, North Carolina.

Until additional materials belonging to this species are forthcoming we must remain
uncertain as to its generic relationships.

Amyda? cellulosa (Cope).

Trionyx cellulosus, Cope, Proc. Acad. Nat. Sci. Phila. 1867, p. 142.—Hay, Bibliog. and Cat. Foss.
Vert. N. A., 1902, p. 453.—CaseE, Maryland Geol. Surv., Miocene, 1904, p. 62.

The unsatisfactory remains on which the present species was founded were collected, as
stated by Cope in the beginning of the paper cited above, in Charles County, Maryland, not
far from the Patuxent River, in the beds of the Yorktown epoch. These remains were never
figured and appear to be lost. The following is Cope’s original and only description of them:

‘Two small fragments of the carapace are all that represent this species. The sculpture is, however,
exceedingly characteristic, and different from that of any recent or fossil species known to the writer.

The surface is marked by numerous closely placed pits, which are remarkably deep, producing the
vesicular appearance of scoria. The resemblance is heightened by the irregular size of the pits. Edges
of septa rounded. ‘The fragments are unusually thick, indicating a species of large size.

Lines
Width of free portion of rib at origin. ..... ‘ ep sites: 7.5 [15.6 mm]
Depth of portion of carapace aan teint 202 4:33 [9 mam.

The deposits in which this species was found are now known as the Calvert formation of
the Miocene.

In the same locality and formation Professor Cope found other fragments of a trionychid
which exhibited larger and more regular pits, separated by wider partitions (Proc. Phila.
Acad. 1867, p. 143). To these he gave no specific name and the specimens appear to be lost.

Genus TEMNOTRIONYX nov.

‘Triturating surface of maxilla with a sharp ridge running parallel with the cutting-edge
of the jaw. Presence of preneural and the number of the costals unknown.
Type: Te -mNotrion yx manducans Hay.

Temnotrionyx manducans sp. nov.
Plate 105, figs. 2, 3; text-fig. 690.

In the Bridger beds, near the mouth of Cottonwood Creek, Wyoming, in 1903, the writer
found some fragmentary remains of a trionychid which appears to be hitherto undescribed.
The specimen is now in the American Museum of Natural History, New York, and has the
catalog number 5929. ‘The remains consist of the left quadrate and prootic, a portion of the
right maxilla, the median portion of the nuchal, one neural, probably the fifth or sixth, the

TRIONYCHID&. 535

sixth costal plate nearly complete, fragments of several other costals, nearly the whole of the
right hyoplastron, the mesial two- thirds of the right hypoplastron, one cervical vertebra, the
proximal portion of the right femur, the distal ae of the right humerus, and some other, but
unimportant, fragments. "Whether or not there was a preneural can not yet be determined.

The individual was a very large one, the plastral bones indicating that the width of the
plastron was little short of 600 mm. An estimate, not wholly reliable, made from the costals
present, indicates that the length of the carapace was about 500 mm. It is quite probable that
the carapace was at least as broad as long.

The skull was correspondingly long. A comparison of the united quadrate and prootic
with those of Platypeltis ferox indicates a length of skull of 225 mm. from snout to occipital
condyle, but little less than nine inches. The fragment of maxilla indicates a shorter skull,
about 7 7 inches. It is not improbable that the front of the skull was relatively short. “The
quadrate and prootic offer no peculiarities when compared with those of P. laty peltis ferox,
except that in the latter the anterior ends of the borders which articulate with the parietal and
the quadrate respectively rise considerably as they approach these bones, thus making the
anterior end of the prootic somewhat gutter-like; whereas, in 7. manducans the rise of the
prootic on each side is slight and the front border of the bone is quite flat.

The fragment of the maxillary offers the most interesting modification. Fig. 2 of plate 105
represents the bone from the outside; fig. 3 from below. The lower border of the bone forms
a prominent cutting-edge, such as we find in many other trionychids. Inside of this cutting-
edge there is, in other trionychids, a horizontal masticatory surface which may be very narrow

‘
ees ee
the

' Val

Fic. 690.—T emnotrionyx manducans. Plastron of type. ¢.

or of moderate width, or very broad; but it is always nearly plane. In 7. manducans, on the
contrary, this masticatory surface is traverst from one end to the other by a sharp ridge, such
as we find in various Emydide and Testudinide. ‘The ridge is not at all tootht. Mesiad of it
the palatal surface of the bone past inward and somewhat upward to the choanz, and to meet
the vomer in front and the palatine behind. The structure of the jaw indicates that the animal
was accustomed neither to seizing and swallowing whole a living prey nor to crushing shells
and other hard objects; but rather to masticating animal and vegetable substances of a mod-
erate hardness.

The nuchal bone offers one peculiarity. In the midline, on the under side equally removed
from the anterior and the posterior borders, is an oval depression 14 mm. long and 10 mm.
wide. It probably served as the attachment of a ligament. The bone does not come to an edge
in front, but is truncated. The thickness is 16 mm. The antero-posterior extent of the bone
was 55 mm. The lateral extent is unknown. There appears to have been a smooth band
along the anterior border, narrow at the midline, while the remainder is covered with shallow
pits, 4 or § in a 20 mm. line.

Some of the costals indicate a considerable convexity of the carapace. One fragment from
the middle of the length of the shell has a width of 65 mm. and a thickness of 10 mm., near the
sutural border. The sixth costal is 51 mm. wide proximally and 95 mm. wide at the free border.
Its thickness is 12 mm. at the posterior sutural border. The upper layer of the bone of the
costals overhung somewhat the middle layer, so that there was a sharp channel running around
the border of the carapace. Notwithstanding the age of the individual the ribs projected con-
siderably beyond the borders of the disk, in one case 42 mm.

530 FOSSIL TURTLES OF NORTH AMERICA.

The sculpture of the carapace was of moderate coarseness. On the distal halves of the
costals the pits are in rows parallel with the free border of the costal, and there are five of these
rows in a line 20 mm. long. Proximally the pits are no longer in rows and are larger, 3 or 4
in the distance named. Aihe sutural borders of the costals are striated across the sutures.

Fig. 690 represents the known bones of the plastron. A portion of the hyoplastron is miss-
ing, Nine it is quite certain that the outer end has been placed very close to its proper position.
This bone had an extent laterally of about 252 mm., not including the antero-external spine.
It is remarkable for the narrowness of the end next the midline, this being only 60 mm. The
width at the bridge was about 52 mm. ‘The greatest thickness of the bone is about 17 mm.
The outer end of the hypoplastron is wanting, as well as the hinder border of the bone. The
bottom of the notch receiving the inner process of the xiphiplastron is present, so that the form
of the hypoplastron given in the drawing is not far from correct. The width at the narrowest
part of the bridge is 37 mm., being thus less than that of the hyoplastron. The thickness at
the bridge is 21 mm.

On account of the advanct age of the individual, the layer of the bone forming the

“callosities” extended itself to the ents of the processes at the midline. The lower surface of the
plastral bones is nearly smooth, but shows everywhere the vestiges of pits and ridges. Where
distinct enough to be perceived they seem to have been smaller than those of the carapace.

The sculpture of the carapace of this species resembles that of dmyda uintaénsts, consisting
of large pits at the proximal end of each costal and somewhat smaller ones in rows at the distal
end. Those of 7. manducans are, however, somewhat larger, in corresponding situations.
The shell, too, is thicker. The greatest differences are found in the plastra of the two species.
In 4. wintaénsrs the inner end of the hyoplastron is two and a half times as wide as the nar-
rowest portion at the bridge; whereas, in J. manducans the two portions are of nearly the
same width. The front border of 4. wintaénsis was quite concave, while that of T. manducans
was nearly straight. It is not probable that such differences can be due to difference in age.
The type of 4. wintaénsis is about four-fifths as large as that of the present species.

From dAmyda scutumantiquum the present species differs in the same way that it does
from A. uintaénsis; that is, in the narrowness of the inner end of the hyoplastron. A. radula,
whose nuchal has a similar thickened anterior border, differs in having a thinner shell, the
free borders of which are beveled, and in having a finer sculpture. 4. egregia has a thicker
shell, a coarser sculpture, and no overhanging layer at the free borders. 4. cariosa, of the
Wasatch of New Mexico, evidently had eich deeper and more abrupt pits on the proximal
ends of the costals. The bone regarded by Cope as a xiphiplastral was deeply pitted, a con-
dition not to be expected in T. ee Sen Aspideretes guttatus has a different sculpture
and a relatively broader bridge. Aspideretes ellipticus had a nuchal whose anterior border
was beveled off on the upper surface.

Genus PLATYPELTIS Fitzinger.

Carapace with the eighth pair of costals wanting or greatly reduced. No preneural. One
or two of the posterior pairs of costals may be in contact on the midline, or all may be separated.
Young in the living species with smooth or granulate skin.

he type of rhe genus Platypeltis is Te niu ferox Schneider (=Trionyx ferox of Boulen-
ger’s Catalogue). He known living species are all inhabitants of America.

Key tro Fosstt Species oF PLATYPELTIS.
A‘. Puerco or Torrejon species:
1. Nuchal probably loosely attacht to first costals. No welts on carapace. Six pits
in a line 10mm. long....... : Oe, teoe. ere eos PMR eco a Mes ainsi ene antiqua
*. Wasatch species:
Disk of carapace not as wide as long; with ribs projecting far beyond disk.
Nuchal probably loosely connected with its costals and neural; sculpture coarse,

tS
t

Wit WEltS ys. < siace'Sts a's CWS re ste eats Ore, ee ee eee ee sertalts
2. Sculpture coarse, especially on proximal ends of the costals, but without welts.
Anterior border of hyoplastron concave............... So ae ope eahsgiies eae) ca aE amnicola
A’. Bridger species:
1. See AY eee : PERE Ee et ects ae ee sertalis

. Nuchal sutured to first cost: tals; welts not t conspic uous; 5 to 7 pitsinIOmm.... tre ptda

”

TRIONYCHID. 537
3. Carapace oval, not so wide as long, archt; nuchal about half the width of cara-
pace; pits of costals small and shallow; hinder end of carapace with longitudinal
TUE Se noe re ee PN nse SN rch Coed ied Lites suse as 2? yaad s (0S (Seen biahe Bie mae cine deg aca trionychotdes
4. Carapace as broad as long; nuchal hardly half the width of the carapace; a, :
smooth band along its front; sculpture coarse near raatcolbt Vana ae oe eee heteroglypta
5. Carapace broader than long; nuchal more than half the width of carapace;
pitted to free border; sculpture as in DECCCOMN Purser am Samy choses os: postera
6. Carapace broader than long; nuchal not half the width of the carapace;
sculpture like that of heteroglypta Re ee chap mi uetame: ntepers ie eile \ar eels et wars : extensa

A‘. Oligocene species:
1. Carapace thin, broader than long; nuchal 0.6 the width of the carapace; a
fontanel each side of first neural.......... shes eee toes ah ete . leucopotomica
A®. Pliocene and recent species:
1. Carapace elliptical; longer than wide; nuchal about half the width of the cara-
pace; sculpture rather coarse..........-.-- Sakic oatutle aun casinene ine ferox

Platypeltis antiqua Hay.

Fig. 693.

Platypeltts antiqua, Hay, Bull. Amer. Mus. Nat.
Hist., XxX111, 1907, p. 859, fig. 18.

The specimen which represents this species
appears to have been collected for Professor eae
Cope by Mr. D. Baldwin, in 1883, in the
Torrejon beds of northern Mexico. It pre-
sents wholes or parts of 5 pairs of costals and peor
5 neural bones. Some other bones are buried
in the very refractory matrix. The catalog
number 1s 1036. : :

The carapace | Neural. | Length. | Width. | res

(fig. 693) had a ‘ Bese!)

length of about ies a aces U
5 3 | 16 | 9 ra a in
1oo mm. and a4 | 15 | 8 a cece, os
a = / ee é Rane eee
width of 78 mm.; | 5 mo 6 | {les < 3 2 =

= 7

but the ends of — ge rac Sas
the ribs extended beyond the disk at least 18
mm. What is evidently the first costal is 20
mm. long, from neural to distal end, and 13
mm. fore and aft. Its anterior border is smooth, showing that it was not suturally joined to
the nuchal. The table shows the dimensions of the neurals present. They are from 2.5 mm.
to 3 mm. thick.

The surface of the costals presents no welts, but is everywhere pitted. On the proximal
ends of the costals there are 6 pits in a 10 mm. line; on the outer ends, 5 pits.

..
y
y
'
'
4
\
nM

Fic. 693.—Platy peltis antiqua. Carapace
of type. X 3.

Platypeltis serialis (Cope).
Plate 98, fig. 13; plate 109, figs. 1-4; text-figs 694-696.

Trionyx, Letpy, Contrib. Ext. Vert. Fauna West. Terrs., 1873, p. 180, plate xvi, fig. 11.

Plastomenus ?thomasii, Corr, Syst. Cat. Vert. Eocene, New Mexico, 1875, p. 35-

Plastomenus thomasti, Corr, Wheeler’s Sury. W. tooth Merid., 1v, 1877, p. 49. (Not Trionyx thomasi
Cope, 1872.)

Plastomenus thomast, Core, Vert. Tert. Form. West, 1884, p. 125. (Not Trionyx thomastt Cope, 1872.)

Plastomenus serialis, Copr, Wheeler’s Surv. W. tooth Merid., 1v, 1877, pp. 48, 51, pl. xxv, figs. 8-10;
Vert. Tert. Form. West., 1884, p. 123.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1903, p- 453-

Platy peltts sertalis, Hay, Amer. Geologist, XXXV, 1905, Pp. 337:

The types of the present species appear to have been lost. We must, therefore, depend
for the identification of the species on the author’s description and illustrations. Professor
Cope possest fragmentary remains of five individuals, which he had obtained from the Wasatch

528 FOSSIL TURTLES OF NORTH AMERICA.
25

deposits of New Mexico. His figures represent fragments of 3 costal plates. He states that
the species is readily distinguisht by the closely placed subparallel ridges which cross the ribs
parallel to the axis of the body and which are separated by one or two rows of imprest dots,
or small fossz.

The costals varied in width from 18 mm. to 27 mm. and in thickness from 3 mm. to 5
mm. Three and a half ridges occupied a space of 9 mm.

The American Museum of Natural History expedition of 1903 to the Bridger beds in the
region about Fort Bridger, Wyoming, secured a large portion of the carapace and a consider-
able part of the plastron of a specimen which it appears necessary to refer to Cope’s Wasatch
species. When, however, more satisfactory materials of the latter have been secured, it may
Bre that the Bridger remains belong to an unnamed species.

Cope’s assignment of his materials to the genus Plastomenus depended on no part of the
plastron, and was therefore inconclusive. There is reason to believe that the Bridger speci-
men does not belong to Plastomenus, but must be assigned to Platypeltis. It bears the cata-
log number 6014.

Of the individual here described (plate 98, fig. 13) there are present most of the first
neural and the whole of the third; practically all of ihe 6 anterior costal plates, and a fragment
of the seventh; the mesial half of the right hyoplastron and hypoplastron; and Somewiae. more
of the mesial half of the same bones of the left side.

It is evident that the nuchal of this individual had no sutural connection with the costals
of the anterior pair; whether or not it had such connection with the first neural is made doubt-
ful by the fact that the anterior portion of this bone is missing. The hinder border of the
carapace being gone, as well as the nuchal, the length can not be determined. From the front
of the first costal to the hinder border of the sixthis 95 mm. Judging from the curve of the free
borders of the sixth costals, but a few millimeters, perhaps 10 mm., would have been added
by the seventh costals. If now we add 10 mm. as the width of the nuchal, we shall have as
the probable length of the carapace 105 mm. ‘The width of the disk is t00 mm. How far the
ribs projected beyond the disk can not be determined.

The first neural had a length of about 16 mm. and a width of 13 mm. The third has the

same length, but 1s 12 mm. mide! Both are of hexagonal form, with the narrow end directed

forward. The sixth neural was also of the same form, but had the narrow end directed back-
ward. ‘There was present a small seventh neural wedged in between the costals of the sixth
and seventh pairs.

The third costals are 17 mm. wide near their outer ends, 3.5 mm. thick near the sutural
borders, and 5 mm. thru the rib. Toward the outer ends of the costals the ribs become quite
prominent on the inner surfaces of the former.

The ornamentation of the carapace agrees with that of Cope’s Plastomenus serialis.
There are on each side about 7 longitudinal ridges, or welts. These are low on the front of the
shell but much more prominent posteriorly. Five of these ridges cross the sixth costal. Be-
tween the ridges there are from 1 to 3 rows of pits of varying sizes. On the neurals there are
only small pits, or puncte.

The plastron of this specimen, so far as represented, was like that of Platypeltis spinifera.
The width of the hyoplastron (plate 109, fig. 3), where narrowest, is 7 mm.; that of the hypo-
plastron at the same place, is 10 mm. ‘The inner end of the former bone expanded into a
single flat process; that of the hypoplastron into two such processes. A callosity of 15 mm.
wideh occupied these bones along their common suture, about half of it on each bone.

No. 5944 of the American Mitisedea of Natural History, a specimen collected at Grizzly
Buttes, Wyoming, in 1903, is referred to this species. It consists of portions of the carapace,
the right hyoplastron and hypoplastron nearly complete, the median halves of the same bones
of the] left side, portions of the pectoral and pelvic g cirdles, and parts of the humerus and femur.
These belonged to an older and larger individual than the one just described. The carapace
(plate 109, fie. 4) 1s remarkable for the strong development of the longitudinal ridges; but it
is not believ ed that a distinct species is indicated. One fragment belongs to the hinder rm
of the carapace, and presents the seventh and eighth costals of the right side. The eighth
costal was small. The plastron (plate 109, fig. 2; text-fig. 694) is in a more advanct stage of

TRIONYCHID&. 539.
growth than that of the specimen numbered 6014. The so-called callosities are much more
extensive, a feature of age. Des have a width of about 40 mm. The length of the hyo-
hypoplastral suture is 74 mm.; . the width of the bridge is 27 mm.; the thic kness at the bridge,
7mm. A comparison of the femur (fig. 695) with corresponding parts of P. spinifera appears
to show that the shaft was nowhere so slender as in the living species, while the distal end was
not so broad. The parts of the pelvis present display no important differences when compared
with the pelvis of P. spinifera.

Mr. Paul Miller, of the American Museum of Natural History expedition of 1904, collected
a nearly complete carapace (No. 3947) of a trionychid which the wniter refers to this species.
It is shown on plate 109, fig. 1; text-fhg. 696. This came from the lower portion of the beds
designated as.\Geandiis therefore of later date than the Grizzly Buttes specimens. The striking
feature in the carapace is the feeble development of the longitudinal ridges, or welts, the
specimen presenting thus a great contrast to No. 5944. The Tidges are moderately distinct
on the last three pairs of costal plates, but farther forward they rapidly become obsolete.
The pits are of the same size as in the other specimens and are separated by rounded walls.

Fics. 694-696.—Platy peltis sertalis.

694. Plastron. 3.

695. Femur. X1.

696. Carapace. <4.

The nuchal of this specimen also is missing. It must have been very loosely attacht,
just as it is in P. spinifera, even the first neural having its anterior border smooth. The left
eighth costal is missing. The length of the specimen, as known, is 131 mm.; with the nuchal
it was probably about 150 mm. The width of the disk, exclusive of the rib ends, is 105 mm.;
but including these, it was about 175 mm. It must therefore have been a more elongated
amimal than P. spinifera. The great extension of the rib-ends beyond the disk shows that it
was only of medium age.

The disk is rather fat, and was probably so during life. There are six neurals. The fifth
comes into contact with only its own costals. The sixth is triangular and reduced in size.
The costals of the eighth pair are small and hardly come into contact at the midline.

In the Vertebrata of the Tertiary Formations of the West, 1884, p. 126, Professor Cope,
in discussing the genus Plastomenus, writes as follows: ‘‘The true P. thomasi: was founded
on sternal bone[s] perhaps of a small species of Trionyx.” Since in the earliest description of

540 FOSSIL TURTLES OF NORTH AMERICA.

this species no plastral bones are mentioned, and in subsequent and more detailed descriptions
the plastral bones mentioned are not Trionyx-like, we must regard the name P. thomasii as
belonging to those specimens which were afterward called P. multifoveatus. In the Cope
collection of reptiles in the American Museum of Natural History there are present the median
ends of the right and left hyoplastra and a fragment of the left hy poplastron of a trionychid
which are accompanied by Cope’s labels, which read as follows: : “Plastomenus thomasit,
hyosternals” and * ‘ Plastomenus thomasit, sternum like Trionyx yx.” The bones bear the number
1022, of the American Museum. It seems quite certain that thee specimens are the alleged
types of P. thomasii; but it is quite as certain that they have never been described. A com-
parison of them with the plastral bones of Bridger specimens of Platypeltis serialis proves
that all belong to the same species, the oe mance: between the hyoplastra of No. 1022 and
No. 5944 being very close.

Platypeltis amnicola Hay.
Fig. 697.

Platypeltts amnicola, Hay, Bull. Amer. Mus. Nat. Hist. xxi, 1907, p. 860, pl. liv, figs. 5, 6;
text-fig. 19.

The incomplete and fragmentary remains which stand as the type of the present species
were secured by the Ammetican Museum expedition of 1906 into the Wasatch beds of south-
western Wyoming. The specimen was found on Bitter Creek. There are present 2 neural
bones, apparently enough
oe Fic. 697.—Platypeltis amnicola. Left fragments to restore near-
<a SS hyoplastron and hypoplastron ly all the costals, most of
: of type. X2- the hyoplastron and hypo-
plastron of the left side
and the inner ends of
those of the mght side.
The catalog number is
6044.

The carapace had a
length of about 280 mm.
and a width of 200 mm.
or more. The species ap-
pears to have resembled
Platy peltis heteroglypta of
the Bridger beds.

What is regarded as the
/ third neural is 35 mm.
- long, 25 mm. wide, and
6mm. thick. One costal bone is 46 mm. wide at the distal end, while the sixth of the left
side is 36 mm. wide distally. The eighth costal of the right side is present. It is small, and
was evidently inclosed in a notch in the seventh costal. The free ends of all the costals are
beveled off obliquely.

There appear to be no welts on the costals. The pits vary considerably in size. Near the
distal ends the pits are arranged somewhat in rows parallel with the free border, and there are
usually 6, sometimes 7, in a line 20 mm. long. Toward the proximal ends the pits increase in
size so as to be two or three times as large as those of the distal ends. They are arranged
more irregularly also.

The length of the suture between the hyoplastron and the hypoplastron (fig. 697) seems
to have been close to 120 mm. The bridge is 45 mm. wide, and here the bones are 13 mm.
thick. The lower surface of the bones, except the processes, is ornamented with ridges and
pits. Of the pits there are usually 5 in a line 10 mm. long.

We may suppose that the plastron of P. heteroglypta resembled that of P. postera. That
of P. amnicola differs much from that of P. postera, especially in having the anterior border
of the hyoplastron concave, instead of nearly straight.

TRIONYCHID. 541

Platypeltis trepida Hay.
Fig. 698.

Platypeltts trepida, Hay, Bull. Amer. Mus. Nat. Hist. xxi, 1907, pl. liv, fg. 7; text-hg. 20

The single known specimen of this species was found by the American Museum expedition
of 1906 into ihe Bridger beds of southwestern Wyoming. It was secured at Grizzly Buttes in
the level designated as B. The catalog number is 5925.

The nuchal bone is wanting, as well as most of the costals of the right side and all the

ee ea ae neurals except the fourth and the fifth.
1 22 agi The original length of the specimen was
close to 100 mm. The distance from the
anterior border of the first costal to the
hinder border of the fifth at its distal end
is 77 mm. The breadth of the disk is g2
mm. Beyond this the ribs extended at
least 15 mm.

The fourth neural is 11 mm. long and
g mm. wide. The fifth is 10 mm. long and
8 mm. wide. Each of these bones bears
a low median keel.

The costals are thin, the thickness being
about 2mm. The first is 16 mm. wide; the
second is 12 mm. wide at the distal end.

a7
GS Br ., ty The anterior border of the first shows that
LS 4 a ~ B
oi ; Se a it was articulated by a jagged suture with
\ pac
(om eae <\ the nuchal bone. The costals show some

faint traces of longitudinal welts. The pits
are mostly arranged in rows parallel with
these more prominent ridges. There are from 5 to 7 pits in a line 10 mm. long.

The closer connection of the nuchal with the first costals, the finer sculpture, and the keel
on the neurals distinguish this species from P. serralis.

Fic. 698.—Platy peltts tre pida. @aeapace of type. X 3.

Platypeltis trionychoides (Cope).
Plate 110, figs. 1-2; text-figs. 699, 700.

Anostira trionychoides, Copr, Proc. Amer. Philos. Soc., xu, 1872, p. 461.

Plastomenus trionyc hordes: Core, Proc. Acad. Nat. Sci. Phila. oa p- 279; Ann. Report U. S. Geol.
Surv. Wyoming, etc., 1872 (1873), p. 619; Vert. Tert. Form. West, 1884, p. 123, plate xvii, fig. 1.—
Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 453.

Pyatypeliis trionychoides, Hay, Amer. Geologist, XXXV, 1905, p. 336.

Professor Cope originally referred the present species to the genus 4nosterra, a proceeding
due, as he tells us, to the fact that the type specimens were found commingled with various
bones of Anosterra ornata and all were supposed to belong to one species. When the error was
discovered, the trionychoid bones were assigned to Plastomenus. The character of the sculp-
ture doubtless determined this distribution of the species, for it does not appear that Cope
possest any of the plastron. Cope’s figured specimens of his species are now in the U. S.
National Museum, but fragments of ort bones, bearing Cope’s label stating that they are
type specimens, are in the Anierican Museum of Natural History. They are in all probability
portions of the type which have become separated from the figured specimens. All of Cope’s
specimens of the species came from Cottonwood Creek, Wyoming, and hence from the level
known as B.

Figs. 1 and 2 of plate 110 are reproduced from photographs of a nearly complete specimen
of the species which was obtained by the American Museum expedition of 1903 into the Bad-
lands of southwestern Wyoming. ‘This specimen, which furnishes, besides the carapace, a
large part of the plastron, both humeri, and both femora, was found at Grizzly Buttes. The
number of the specimen in the American Museum is 5938. The length of the carapace along

542 FOSSIL TURTLES OF NORTH AMERICA.

the midline is 132 mm.; the extreme width is 117 mm. The carapace (fig. 699) is moderately
convex. The anterior border is broadly rounded; the hinder border is excavated. There
were originally 6 neural bones, of which the first is injured and the fourth is missing. The first
had a length of 21 mm. and a width of 10 mm. The others are shorter and narrower. The
nuchal has a fore-and-aft extent of 18 mm. and a length of 66 mm. from side to side. There
are only 7 pairs of costals. Those of the seventh pair meet at the midline. The costals are
about 3 mm. in thickness. The sculpture of the specimen agrees with that of the type, but it
is more feebly developt. The surfaces of the neurals and the proximal ends of the costals
present shallow pits arranged irregularly. Of these pits there are from 5 to 7 ina line 10 mm.
long. Toward the distal ends of the costals the pits become smaller and more closely packt,
there being about 10 in a 10 mm. line.

The greater portions of both hyoplastra and both hypoplastra accompany the carapace.
There was a considerable fontanel between the hypoplastrals in front and the xiphiplastrals
behind. The mesial half of the hyoplastra and of the hypoplastra are only 3 mm. thick; but
the thickness is somewhat greater near the distal ends of the bones. The bridges are 26 mm.
wide. The length of the hyohypoplastral suture is 61 mm. The sculpture of these bones is
greatly like that of the carapace.

VG,
bon Oe cisco
a { ]
if. =< \ fe) BN
f eae Pi ; Va
| r aaa
pra |
See s
( ea oak X
699. | - Sete
| ras i 2 a
| ; } AN
\ F ea. —_ ~ 2 al a o La
ee af \ se ae
He | | =
\ nth /
\ — |
\ }
K + .
2 \ i :
\ va
= \ Vay
ee \) 1S
Fics. 699 AND 700.—Platy peltis trionychoides. X34.
699. Carapace of No. 5938 A. M. N. H. 700. Plastron restored from No. 5938 and No. 6017 A. M. N. H.

The limb bones present show no important differences when compared with those of P.
spinifera. :

No. 6017, of the American Museum of Natural History, was found at Grizzly Buttes in
1903. It furnishes fragments of the costals, some neurals, and nearly the whole of the plastron
except the entoplastron and the epiplastra, elements of the plastron rarely recovered, on
account of their loose attachment and their delicate construction. This specimen differs from
the preceding only in the boldness of the sculpture, the pits being deeper and the ridges higher
and sharper. It is coarsest on the outer ends of the hyoplastrals and the hypoplastrals.. From
this specimen has been drawn most of the plastron as represented in fig. 700, but parts of
this figure have been taken from the plastron of No. 5938.

No. 5942, American Museum, also from Grizzly Buttes, belonged to a larger and an older
individual than the specimens already described. The hyoplastron is co-ossihed with the
hypoplastron. Following the line of the missing suture, the distance is g2 mm. The bones
are a little over 4 mm. thick on the mesial half; at the bridge they are about 8 mm. thick.
The sculpture is strongly exprest, especially on the bridges.

The xiphiplastron differs in having the outer border, near the base of the process entering
the hypoplastron, expanded outward. This is due probably to the greater age of the animal,
The bone is 5 mm. thick; that of No. 6017 is 4 mm,

TRIONYCHID.

nN
>
W

Platypeltis heteroglypta (Cope).
Plate 98, fig. 14; plate ror, fig. 2; text-figs. 701, 702.

Trionyx heteroglyptus, Cope, Proc. Acad. Nat. Sci. Phila. 1873, p. 277; U.S. Geol. Surv. Terrs.,
6th Ann. Report, 1872, (1873), p. 616; Vert. Tert. Form. West, 1884, p. 120, plate xvi, fig. 2.—
Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454-

Platy peltts hateroglypius, Hay, Amer. Ceclovist, XXXV, 1905, p. 336.

The type of this species is the hinder half of a carapace and the complete nuchal bone,
which were collected in 1872, by Professor Cope, on the summit of Church Butte, Uinta
County, Wyoming. This specimen is now in the American Museum of Natural History,
New York, and bears the number 1039. Cope figured it, as above cited, and attempted to
restore in outline the missing parts; but, as stated in the explanation of the plate, too few
costals are represented. As “there restored, the carapace is considerably broader than long,
which almost certainly was not the case. Certainly 2, and possibly 3, costals come in front SE
the most anterior costal present, the fifth one from the rear. In the diagram here presented
(hig. 701); the carapace is restored with 7 costals, the number present in the living American
species of the family. There is a neural ple between the hindermost costals. These costals
may be those of the eighth pair and the neural therefore the eighth; but an eighth neural is
so seldom dev elopt ( (Amyda «qua) that it is more probable that fies is the sev enth neural and
the costals those of the seventh pair. For this reason the species is referred to the American
living genus Platypeltis.

Cope has represented the distal end of the fifth costal from the rear as being drawn in
farther than the specimen justifies. In fact, its free margin stood out nearly as far as did that
of the next one behind.

Professor Cope did not know of the nuchal, it having been found, since the specimen came
into the American Museum, lying in the matrix beneath the hinder end of the carapace. Its
antero-posterior breadth, in the midline, is 26 mm.; its length, from side to side, about 120 mm.
It is therefore rather small for a turtle of the size. This nuchal articulated with the first neural
and probably with the anterior costals without fontanels. The upper surface is sculptured on
the anterior edge for 26 mm. on each side of the midline, Beyond this, the surface is devoid
of ornamentation. At the ends of the sculptured area the thickness is 10 mm. The outer ends
of the nuchal were partially overlapt by the outer ends of the first pair of costal plates.

The carapace was possibly quite flat, but more probably it had considerable convexity.
There is a narrow, but rather deep notch in the hinder margin of the carapace, at the midline.
The measurements given in Cope’s description are correct. The greatest width is 250 mm.,
taken between the distal ends of the fourth pair of costals from the rear. The distance from
the rear of the shell to the anterior border of the most anterior costal present is 162 mm. The
total length of the shell may be estimated at from 250 mm. to 280 mm. The thickness of a
costal plate near its sutural border is 6 mm. The ribs stand out conspicuously on the under
side of the plates, and thru them the thickness amounts to Io mm. Cope states that the free
portion of the costal is short. This probably refers to the projection of the rib beyond the
plates. The rib of the penultimate costal is present and projects at least 33 mm. The hinder-
most pair of costals join along the midline for 25 mm. The neural which is lodged between the
front borders of the hindermost costals is 14 mm. long and just as wide. ‘lhe next neural
in front seems to have been 24 mm. long and sect 14 mm. wide. — Its broader end 1s
directed forward, and its anterior angles come into contact with the antepenultimate costals.
A portion of the antepenultimate eure is present and appears to have had about the same
width as the ones behind it. Its length was about 25 mm., and it has lain wholly between the
costals of the antepenultimate pair, coming into contact with neither the pair in front nor that
behind. Its hinder end has been slightly Broader than the front end. Only a fragment of the
neural next in front of the one just deccHibea | is present. Its broader end has beet directed
backward and this has come into contact with the antepenultimate costals. The first neural
has had a convex anterior border to fit the concave border of the nuchal.

The sculpture of the different parts of the shell varies greatly. On the proximal ends of
the hindermost costals it is coarse and consists of longitudinal ridges, with some lateral spurs.
In the middle of the length of the other costals there is a network of ridges inclosing pits which

544 FOSSIL TURTLES OF NORTH AMERICA.

are 3 mm. or less in diameter. On the outer ends of these costals the pits are even smaller,
and are arranged more or less in rows across the costals. On the nuchal the pits are small and
shallow.

To this species is referred the specimen represented by fig. 702. It was collected by the
American Museum expedition into the Bridger deposits in 1903. The more exact locality
is the eastern part of Grizzly Buttes, Wyoming. The number of the specimen 1S 5910.

Only small portions of the carapace are missing. The median region of the nuchal is
gone, and the second and third neurals. There are 81 pairs of costal plates, but the eighth pair
is vestigial and might therefore be missing in other individuals of the same species. The
total length of the carapace 1s 286 mm., the width almost exactly the same. Originally the upper
surface may have been about as convex as the carapace of Platy peltis ferox, of Florida.

There is no preneural. The length of the first neural is 50 mm.; its width anteriorly,
31 mm., posteriorly, 16 mm. The fourth neural is 29 mm. long, 18 mm. wide. The fifth is
25 mm. long, 14 mm. wide. The sixth neural is pointed behind, 17 mm. long and of about the
same width. It permitted the costals of the sixth pair to meet in the midline behind it. It is
uncertain whether or not there was a small seventh neural.

Fics. 701 AND 702.—Platypeltis heteroglypta. Carapaces. Xt.

jor. Carapace of type. 7oz. Carapace of No. 5g10 A. M. N. H.

The nuchal of this specimen is of greater extent fore and aft than in the type, being about
33 mm. The distal ends past beneath the border of the first costal plate, but apparently not
beneath the mb of that costal. The free ends of the carapacial ribs projected beyond the mar-
gin of the shell about 27 mm.

The sculpture resembles closely that of the type specimen, consisting of large cells on the
neurals and the proximal ends of the costals and of smaller cells on the distal ends of the
costals. On the distal ends of the costals the cells are arranged somewhat in rows parallel
with the adjacent border of the carapace.

Any possible doubts regarding the specific position of the specimen would arise from the
fact that the nuchal is Sonmew iat broader from front to back than in the type; that the costals
are somewhat thinner, being only about 5 mm.; and that the free ends of the costals are
beveled down to an acute edge, instead of being more or less obtuse as in the type. The dis-
tahce from the hinder border of the carapace to the suture between the second and third
costals is almost the same in the two specimens under consideration; but the width of the
carapace of the recently acquired specimen is about 30 mm. greater than in Cope’s type.

It is not believed that these differences indicate a distinct species. The thinness of the
bones may be due to pressure during the early stages of fossilization; the greater width of the
carapace to a more advanct age.

ae —

TRIONYCHID. 545

Platypeltis postera sp. nov.

Plate 111, figs. 1, 2.

The type of this species is No. 6133 of the American Museum. It was collected by the
museum’s expedition of 1905, at Sage Creek Springs, Wyoming, in deposits belonging to the
level known as C, therefore somew hat above the level of the s specimens of P. he teroglypta, its
nearest relative. The length of the carapace (plate 111, fig. 1) in a straight line is 315 mm.;
the greatest width, 342 mm. The upper surtace is strongly convex from front to the rear and
from side to side. This form is certainly natural. The nuchal is 39 mm. from front to rear,
182 mm. from side to side. There is no smooth band along its front. ‘he 7 neurals are all
present, and have the dimensions shown in the table. The seventh partly separates the
costals of the seventh pair. Behind this these costals join along the midline a distance of 57mm.
The left one of the pair measures along the free hinder border 80
mm. The costals are thicker than in either of the specimens of
P. heteroglypta but this may be due to its being an older indi-
vidual. At their distal ends and near the suture ‘they are g mm.

|
Neural. Length. | Width. =

1 57 31 thick. These ends are abruptly beveled or truncated.
: = The sculpture is better displayed than in P. heteroglypta,
ener 3 | No. 5910, but has the same general character. It differs, how-
| 5 ar : ever, in that the ridges between the pits are narrower and
hl oa 16 e sharper. It consists of pits, which are very large on the neurals

and the proximal ends of the costals, much sialic on the distal
ends of the costals and on the front of the nuchal. In the median

region there are 3 pits in a line 13 mm. long. Occasionally they are slightly larger than this.
On the distal ends of the costals fee are about 5 pits in the line indicated.

The plastron (plate 111, fig. 2) lacks only Ae entoplastron, the epiplastra, and the outer
ends of the right hyoplastron and hypoplastron. The form and relative size of the various bones
may be determined from the plate. The hyoplastra are solidly co-ossifed with the hypoplastra.
The lower surface of all these bones is covered with the sculptured layer. Ev erywhere, except
on the outer ends of the hyoplastra and hy poplastra, the pits are nearly abvalete: On the outer
ends of the bones mentioned there are about 5 pitsina 15mm. line. The line along which the
hyoplastron and hypoplastron are united is 130 mm. The bridge is 64 mm. wide. ane bones
are about 12 mm. thick.

A specimen, No. 5955 of the American Museum, was collected in 1906 at Grizzly Buttes,
Wyoming. It is smaller ian the type; but the nuchal resembles that of the latter, having the
sculptured layer covering the whole upper surface.

This species is certainly closely related to P. heteroglypta. The shell was probably more
convex in life than that of the latter species. The bones are thicker and the free borders are
more abruptly cut off than in P. heteroglypta. The nuchal is longer from side to side and
there is no smooth band along the free border. Nor is there a smooth band of any considerable
width on the free ends of the costals, as there is in both specimens of P. heteroglypta.

Platypeltis extensa sp. nov.

Plate 112; text-fig. 703.

The species here described is represented by only an imperfect carapace and plastron
which were secured by the writer during the summer of 1903, in the Bridger deposits of the
western part of Grizzly Buttes, Wyoming. When discovered the specimen was much broken.
The fragments have been fitted together with all possible care, with the result that the form
and the essential structure of the shell are revealed. A considerable area near the front of
the carapace is yet missing; likewise a portion of the rear. The position and extent of the
missing portions are show! n by the figure on plate 112. The catalog number of the type is
5951 of the American Museum of Natural History.

In form the carapace is broader than long, with a broad and somewhat rounded front and
a broadly truncated hinder end. The upper surface possest a moderate convexity, and this
is probably not different from the form in life. The total length is 300 mm.; ; the width, 345
mm. Apparently there were present only 7 pairs of costal plates. Posteriorly the bone 1s
present nearly to the midline; and in case there were 8 pairs of costals the posterior must

35

540 FOSSIL TURTLES OF NORTH AMERICA.

have been quite vestigial. “The costals of the first pair are, at their proximal ends, much
wider fore and aft than those behind them, being about 53 mm. wide, and they increase in width
toward their distal ends. The third and fourth costals are narrow at their proximal ends,
ote” en being respectively 36 mm. and 33 mm. wide, and they
ar ee expand little toward the distal ends. The fifth and sixth
= —— ~ are likewise narrow proximally, but they expand rapidly
, 4 toward the margins of the carapace. The seventh cos-
m \ tals extend on each side about 66 mm. from the midline.
{ 3 \ The free ends of the costal ribs extend little, if any,
. . ; beyond the margins of the carapace, thus affording evi-

cme dence that the individual was an aged one.
= 4p as J The carapace is thick and solid. Near the proximal
} | ~~~) ends the costals are 6.5 mm. thick and this thickness
i ou increases toward the margins of the carapace, where it
ae le cE ees amounts to 8 mm. in front and behind, and to 12 mm.
| ' + and even 15 mm. at the sides. The borders of the cara-
\ ' pace are not beveled off as in many species. Anteriorly
_ ~ and posteriorly the edge is rounded; at the sides the
a / upper layer of bone ov erhangs the lower, and a groove

: / runs along between them.

There was probably no preneural. The first neural

= ey, is missing, but the proximal border of the left first costal
‘ 7 Se:
H ” i indicates that the neural was long and narrow, with the
te narrower end forward. Only a fragment of the second

neural remains. The third neural had a maximum width
Fic. 703.—Flatypeltis extensa. Cara- Of about 23 mm.; the fourth a width of 20 mm.; the fifth
pace of type. X }. a width of 17 mm. The more posterior neurals have not

been preserved.

The nuchal bone is relatively small. Its lateral extent is 158 mm.; its fore-and-aft measure-
ment, 29 mm. The outline of the anterior border is nearly straight, and the immediate edge
is rounded and about 7 mm. thick.

The sculpture of P. extensa resembles closely that of P. heteroglypta, consisting of large
pits, about two 1n a line 10 mm. long, on the neurals and the proximal ends of the eoatale. and
of smaller cells, three 1n 10 mm., on the distal ends of the costals. The large pits have broad,
low, and rounded walls surrounding them, while the walls of the smaller pits are more sharply
defined. On the outer ends of the ‘ostals the pits show some tendency to arrange themselves
in rows parallel with the margins of the carapace,

This species differs from P. heteroglypta in its greater breadth as compared with the length,
and in the thickened and grooved lateral borders of the carapace.

The left hyoplastron and hypoplastron are complete, except the tips of the outer processes.
The two bones are thoroly co-ossified. The sculptured layer, the callosities, extends to
the midline. The length of the hyohypoplastral suture is 176 mm. The width of the bridge
is 62 mm. Here the thickness of the hypoplastron is 11 mm. The hyoplastron is somewhat
thinner. Near the inner end of the anterior border of the latter bone there is a deep notch for
the entoplastron. At the hinder outer angle of the hypoplastron is a notch for a process of the
xiphiplastron. The humerus differs only j in details from that of P. spinifera. Its total length
is 87 mm.

Platypeltis leucopotamica (Cope).
Plate 113, figs. 1-3; text-fig. 704.
Trionyx leucopotamicus, Cope, Contrib. Canad. Paleont., 11 (4 to), 1891, p. 5, plate i, figs. 8, ¢.—Amr,

Science (1), Xvi, 1891, p. 53.—Hay, Bibliog. and Cat. Foss. Vert. N. A., 1902, p. 454.

Trionyx punctiger, Cope, Contrib. Canad. Paleont., m1 (4 to), 1891, p. 5.—Hay. loc. cit. » P- 454.

The type of this species is a fragment of a costal plate 33 mm. long and 25 mm. wide,
which was found in the White River deposits of the Cypress Hills, District of Alberta, British
America. Professor Cope’s description was reinforced by some fragments of what he regarded
as the same species, which he had obtained in the White Buttes of North Dakota. One of

TRIONYCHID&. 547

these fragments, a piece of a costal, was figured in the report above cited. The larger piece
of costal which Cope figured belongs to the Geological Survey of Canada, and the present
writer has been enabled to study it and compare it with the carapace to be here described.

In the collection of the American Museum of Natural
History, there is the nearly complete carapace of a triony-
chid which is with confidence referred to Cope’s species.
This specimen, No. 6045 (plate 113; text-fig. 704) was
found in the Titanotherium beds of the Hat Creek Basin,
Nebraska, by Dr. J. L. Wortman, of the American
Museum’s expedition of 1894. This carapace was much
fractured and required much skill and patience on the
part of the preparator to restore it. Portions of the costals
of the right side are missing; but the left side is complete,
as well as the whole margin of the right side. It is pos-
sible that there were originally eight pairs of costals pres-
ent, but the hinder border of the costals of the seventh
pair appear to have a smooth edge, as if having formed
a portion of the free border of the shell. Asin P. hetero-
glypta, there is a neural between anterior borders of the
costals of the last pair present, and there is a notch in
the midline behind which may have lodged a small
eighth neural. This region resembles much that of Pla-
Fic. 704.—Platy peltis leuco potamica. ty peltis spinifera, of North America. a.

Carapace. X 5. No. 6045 A.M.N.H. The carapace 1s broad, slightly concave in front, and
slightly notcht behind. The bones are thin and light,
indicating an animal that lived in quiet waters. ‘This is likewise shown by the fineness of the

matrix inclosing it.

The length of the carapace is close to 325 mm.; the greatest breadth is 353 mm. The
shell is now quite flat, but it was originally probably moderately convex. The thickness of
a costal plate at the sutural border and in the middle of the length is only 5 mm. or 6 mm.; but
thru the rib it is 7 mm. or 8 mm. All around the border the shell is beveled off. The upper,
or proximal, border of the bevel is concave, so that a broad, shallow groove runs around nearly
the whole carapace. Nowhere does the sculptured layer overhang the deeper layers of the bone.
Posteriorly the shell thins out to a blunt edge.

The ribs are very distinctly markt out on the lower side of the costal plates, and they occupy
at least half of the width of each costal. They appear to have projected beyond the borders of
the costal plates only about 15 mm.

The nuchal bone has a fore-and-aft extent of 33 mm., a transverse extent of 212 mm. At its
outer border it overlaps the anterior edge of the first pair of costals.

There are present 7 neural plates. In general, these are broader behind than in front.
The anterior is much larger than any of the others. There is no indication of a preneural.
The front end of the first neural is broadest, and its anterior outer angles bound portions of
2 small fontanels which lie behind the nuchal. The fifth neural is quadrilateral, the sixth is
cofin-shaped, with the broad end forward, and the seventh 1s

Neural. | Length. | Width. hexagonal and short. The table gives the dimensions of the
(rm rs i various neural plates.
| 1 | 65 33K The distal ends of the various costals display considerable
2 40 33. diversity in their widths; and in the specimen in hand those of
; Me . the same pair differ in some cases on the opposite sides. These
5 33 17 variations may be observed on plate 113.
; a 7 The sculpture of this species varies within narrow limits in

different parts of the carapace; as indeed it does in all species.
Here, as in other cases, it is coarser on the hinder parts of the
shell. In general, it agrees closely with the type specimen. It consists of squarish, roundish,
or oval pits, inclosed by rather sharp ridges, which are narrower than the pits themselves.
On the neurals and on a narrow strip on each side of these (plate 113, fig. 2), and again near

548 FOSSIL TURTLES OF NORTH AMERICA.

the outer ends of the costals (fig. 3 of plate 113), the pits arrange themselves more or less in
rows parallel with the length of the animal. On an average there are about 8 pits in a line of
25 mm. Near the middle line posteriorly some of the pits may have twice the average size,
but this is unusual. Along most parts of the sutural borders of the costals there is a strip
which is almost devoid of sculpture, except some striations at right angles with the suture.
This condition is most conspicuous on the proximal halves of the costals.

In a foot-note to the description of his Trronyx leucopotamicus Professor Cope has charac-
terized a species, 7. punctiger, from the White River beds of Billings County, North Dakota.
One of the characters which are given to distinguish the latter from the former is the presence
of a pitless band of surface along the sutural borders of the costals. That is present in the
specimen which has here been described as Platypeltis leucopotamica, but the writer can not
on that account assign it to 7. punctiger. The latter species is said to have the ridges of the
sculpture thickened and irregular and obscure on the outer ends of the costals. That is not
true in the carapace above described. 7. punctiger is said to have the shell thicker than that of
T. leucopotamicus. Cope’s type of the latter species has a thickness, thru the rib, of only
6mm. The carapace here described from Nebraska has a thickness thru the ribs varying
from g mm. to 11 mm., which is the thickness in the same regions of J. punctiger. It appears
to the present writer that 7. punctiger is identical with 7. leucopotamicus; but more materials
must be collected before certainty on this point can be obtained.

It is not known to the writer where the type of 7. punctiger 1s.

Professor Cope in his description of this species spoke of its close resemblance to Leidy’s
Trionyx uintaénsis. Now that we have the complete carapaces of both species, it is seen that
they are extremely different.

Platypeltis ferox (Schneider).

Trionyx ferox, SCHNEIDER, Schildkrote, 1783, p. 330; BouLENGER, Catalogue Chelonians, 1889, p. 259.
Platy peltis jerox, Acassiz, Contrib. Nat. Hist. U. 5., 1, pt. ii, 1857, p- 401.

In the Dr. Jarman collection of fossils obtained in Hillsboro County, Florida, and now the
property of the Vanderbilt University, Nashville, Tennessee, there are several fragments of
plastral and carapacial bones which the writer can not distinguish satisfactorily ae corres-
ponding bones of the above species, now living in the rivers of Florida. With these bones come
others which evidently belong to 2 or 3 undescribed species of the genus; but the fragments
hardly justify the application of systematic names tothem. The beds furnishing these bones
are supposed to belong to the Peace Creek formation.

Dr. Friedrich Siebenrock (Sitzber. Acad. Wien, math.—naturw. Cl., cx1, 1902, p. 829)
regards this species as identical with P. spinifera. In fact the two forms are very distinct.
P. ferox has the carapace much more elongated and the sculpture is much coarser. Their
geographical distribution is different also.

THE END.

Acherontemys, 221
heckmani, 222
Achilemys, 373, 383
allabiata, 383
Acichelys crassipes, 57
acupictus (Plastomenus), 467, 470
acutidens (Holcodus), 187
admirabilis (Conchochelys), 483
Adocida, 224
Adocus, 224, 225, 226, 236
agilis, 236, 242, 246
beatus, 236, 239, 242
firmus, 254
imbricarius, 231
lacer, 236, 241, 242
lineolatus, 236, 247
pectoralis, 254
petrosus, 250
pravus, 236, 242, 246
punctatus, 236, 242
syntheticus, 236, 242, 244
variolosus, 226
wyomingensis, 271
advena (Protostega), 199
agle (Echmatemys), 298, 331
aqua (Amyda), 511, 517
afhnis (Baéna), 67
agilis (Adocus), 236, 242, 246
Agomphus, 224, 225, 226, 248
firmus, 249, 254
masculinus, 249, 255
oxysternum, 249, 256
pectoralis, 249, 254
petrosus, 249, 250
tardus, 249, 252
turgidus, 249
Alamosemys, 226, 260
substricta, 260
allabiata (Achilemys), 383
allabiatus (Hadrianus), 383
Allopleuron hoffmanni, 209
Amblypeza, 102, 122
entellus, 122
amnicola (Platypeltis), 536, 540
Amphichelydia, 25, 43
Amphiemys, 248
oxysternum, 256
amphithorax (Testudo), 397, 407
Amyda, 483, 510
aqua, 511, 517
buiei, 511, 534
cariosa, 511, 515
cellulosa, 511 534
concentrica, $11, 522
crassa, 511, 532
egregia, 511, 531
exquisita, §11, 525
francisca, 511, 523
halophila, 511, 513
lima, 511, 533
mira, S11, 527
pennata, 511, 514

36

INDEX.

Amyda prisca, 511, 512
radula, 511, 517
salebrosa, 511, 524
scutumantiquum, $11, 521
tritor, 511, 529
uintaénsis, 511, 519
ventricosa, 511, 516
virginiana, 511, 515

anguillulata (Terrapene), 364, 366, 367

(Toxaspis), 364
angusta (Lytoloma), 155, 157
Anosteira, 225, 226, 279

ornata, 279

radulata, 281

radulina, 281
Anostira molopinus, 481

odemia, 479

radiolata, 281

radulina, 281

trionychoides, 541
antiqua (Baéna), 62

(Platypeltis), 536, 537
Aspidonectes tritor, 529
Archeochelys, 100
Archelon, 202

ischyros, 202

marshi, 208
arenaria (Hybemys), 345
arenivaga (Testudo), 398, 430
arenosa (Baéna), 60, 67, 76
arethusa (Echmatemys), 298, 323
Aspideretes, 483, 485

austerus, 486, 495

beecheri, 486, 492

coalescens, 486, 488

ellipticus, 486, 505

fontanus, 486, 494

foveatus, 486

grangeri, 486, 507

guttatus, 486, 503

nassau, 486, 498

puercensis, 486, 499

sagatus, 486, 497

singularis, 486, 501

splendidus, 486, 490

vagans, 486, 497

vorax, 486, 496
atascose (Testudo), 398, 464
Atheca, 25, 43
Atlantochelys, 188

gigas, 190

mortont, 188

tuberosus, 187
austerus (Aspideretes), 486, 495
Axestemys, 483, 508

byssina, 509
Axestus, 508

bysimus, 509

byssinus, 509
Baéna, 58, 59

affinis, 67

antiqua, 60, 62

549

bei

Baéna arenosa, 60, 67, 76, 79
callosa, 60, 61
cephalica, 82
clara, 60, 74
emilia, 60, 80
escavada, 60, 65
hatcheri, 60, 63, 92
hebraica, 87
marshi, 60, 61, 62
ponderosa, 271
pulchra, 92
riparia, 60, 76
sima, 60, 71
undata, 85, 87
Baénida, 45, 56
Baptemys, 224, 225, 226, 270
costilatus, 267
fluviatilis, 277
tricarinata, 275
wyomingensis, 270
Basilemys, 224, 225, 226,
imbricaria, 231
ogmius, 226
sinuosa, 229
variolosa, 226
bauri (Toxochelys), 168, 178
beatus (Adocus), 236, 239, 241, 242
(Emys), 239
beecheri (Aspideretes), 486, 492
belviderensis (Glyptops), 53
(Plesiochelys), 53
bisornata (Trachemys), 348, 353
bisornatus (Pseudemys), 353
borealis (Osteopygis), 128, 141
(Propleura), 141
Boremys, 58, 91
pulchra, 92
Bothremydida, 102
Bothremys, 102
cooki, 103, 105
molops, 115
brachyrhina (Toxochelys), 168, 171
Bridger epoch, turtles of, 37, 39
brontops (Testudo), 397, 398
browni (Porthochelys), 182
buiei (Amyda), 511, 534
(Trionyx), 534
bysimus (Axestus), 509
byssina (Axestemys), 509
byssinus (Axestus), 509
celata (Pseudemys), 356
calatus (Glyptops), 52
calaverensis (Stylemys), 386, 396
callopyge (Echmatemys), 298, 340
callosa (Baéna), 60
campester (Testudo), 398, 455
canaliculata (Terrapene), 360, 363
capax (Stylemys), 386, 392
captans (Charitemys), 98
Caretta, 8, 10
Carettochelys, 19
cariosa (Amyda), 511, 515
cariosus (Trionyx), 516
carteri (Emys), 376
Caryoderma snovianum, 438
Catapleura, 127, 128, 150
chelydrina, 136
ponderosa, 152
repanda, 150
catenatus (Plastomenus), 467, 470
cellulosa (Amyda), 511. 534
cellulosus (Trionyx), 534
Cenozoic, turtles of, 38
cephalica (Baéna), 82
(Eubaéna), 82
Charitemys, 58, 98

INDEX.

Charitemys captans, 98
Chelone crassicostata, 154, 160
ornatus, 210
parviscutatus, 220
parviscutum, 220
parvitecta, 220
planimentum, 154
sopita, 149, 155
Chelonia, 209, 220
grandeva, 216
parvitecta, 220
Cheloniide, 8, 9, 19, 208
Chelydosauria, 28
Chelydra, 223
crassa, 263
serpentina, 223
Chelydrida, 32, 221
chelydrina (Catapleura), 136
chelydrinus (Osteopygis) 128, 136
Chisternon, 57, 58, 84
hebraicum, 87
undatum, 85
Chrysemys, 287, 288, 345
inornata, 358
timida, 345
wyomingensis, 308
cibollensis (Echmatemys), 298, 300
(Emys), 300
Cistudo eurypygia, 364
marnochii, 362
clara (Baéna), 60, 74
Classification of turtles, 25
Claudius, 224, 225
Clemmys, 286, 287, 290
hesperia, 290, 292
insculpta, 290, 295
morrisiev, 290
percrassa, 290, 294
saxea, 290, 294
coalescens (Aspideretes), 486, 488
(Plastomenus), 488
(Trionyx), 488

Compsemys, 225, 226, 233
imbricarius, 231
lineolatus, 247
obscura, 235
ogmius, 226
phcatulus, 47
variolosus, 226
victa, 233

concentrica (Amyda), 511, 523

concentricus (Trionyx), 523

Conchochelys, 483
admirabilis, 483

conspecta (Stylemys), 386, 393

cooki (Bothremys), 103, 105

corrugatus (Plastomenus), 467, 473

corsoni (Hadrianus), 374, 376
(Testudo), 376

costatus (Plastomenus), 467

costilata (Kallistira), 267

costilatus (Baptemys), 267
(Dermatemys), 267

Cotylosauria, 28

crassa (Amyda), 511, 532
(Chelydra), 263
(Hoplochelys), 263

crassicostata (Chelone), 154

crassiscutata (Testudo), 398, 459

| crispatus (Syllomus), 211

Cryptodira, 18, 25, 31, 43, 126

culbertsonii (Emys), 386
(Stylemys), 386
(Testudo), 386

cultrata (Testudo), 397, 411

communis (Plastomenus), 467, 473, 481

cyane (Echmatemys), 298, 324
cyclopygia (Testudo), 438
cyclopygius (Xerobates), 438
Cynocercus, 180
incisus, 168, 180
dares (Taphrosphys), 105, 120
Deirochelys, 288, 346
floridana, 346
depressus (Glyptops), 55
Dermatemydida&, 32, 223
Dermatemys, 224, 225
costilatus, 267
mawil, 284
vyomingensis, 271
wyomingensis, 271
see also, 263, 275
Dermochelyide, 14
Dermochelys, 14, 17, 19, 23
Desmatochelyida, 184
Desmatochelys, 184
lowi, 185
distincta (Helopanoplia), 485
Distribution, 30
Echmatemys, 287, 295
zgle, 298, 331
arethusa, 298, 323
callopyge, 298, 340
cibollensis, 298, 300
cyane, 298, 324
euthneta, 298, 305
haydeni, 298, 308, 313
latilabiata, 298, 339
lativertebralis, 298
megaulax, 298, 301
naomi, 298, 335
ocyrrhoé, 298, 329
pusilla, 298, 337
septaria, 298, 319
shaughnessiana, 298, 327
stevensoniana, 298, 316
testudinea, 298, 303
uintensis, 298, 342
wyomingensis, 298, 308
eda (Testudo), 398, 450
egregia (Amyda), 511, 531
elkader (Toxochelys), 168, 174
ellipticus (Aspideretes), 486, 505
emarginatus (Osteopygis), 128, 129
emilie (Baéna), 60, 8o
(Testudo), 398, 419
Emydide, 2, 33, 284
Emys, 286
beatus, 239
carterl, 376
cibollensis, 300
culbertsonii, 386
euglypha, 350
euthneta, 305
firmus, 254
gravis, 269
haydeni, 308, 313
hemispherica, 318, 386
jeanesi, 308
jeanesianus, 308
lata, 386
latilabiatus, 298, 339
lativertebralis, 298
megaulax, 301
nebrascensis, 386
obscurus, 235
owenl, 386
pachylomus, 301, 302
parva, 246
petrolei, 352
petrosus, 250

polycypha, 343

INDEX.

| Emys pravus, 246

septaria, 319
shaughnessiana, 32
stevensoni, 316
stevensonianus, 300, 316
terrestris, 344
testudineus, 303
turgidus, 249
vyomingensis, 308

wyomingensis, 308, 313, 316, 337

enodis (Prochonias), 115
(LTaphrosphys), 115
entellus (Amblypeza), 122
erosus (Osteopygis), 128, 138
Erquelinnesia, 127, 160
gosseleti, 160
molaria, 160
escavada (Baéna), 60, 65
Eubaéna, 58, 82
cephalica, 82
latifrons, 83
Euclastes, 161
platyops, 162
euglypha (Emys), 350
(Trachemys), 348, 350
Eupachemys obtusa, 458
rugosus, 458
Europe, turtles of, 40
eurypygia (Cistudo), 364
(Terrapene), 360, 364
euthneta (Echmatemys), 298, 305
(Emys), 305
eximius (Neurankylus), 94
exornata (Testudo), 397, 401
exquisita (Amyda), 511, 525
extensa (Platypeltis), 537, 545
extincta (Pseudemys), 356
Families of turtles, 25
farri (Testudo), 398, 418
ferox (Platypeltis), 537, 548
(Trionyx), 548
firmus (Adocus), 254
(Agomphus), 249, 254
(Emys), 254
floridana (Deirochelys), 346
(Macrochelys), 222
fluviatilis (Baptemys), 277

| fontanus (Aspideretes), 486, 494

formosa (Xenochelys), 282
foveatus (Aspideretes), 486

(Trionyx), 486, 492
fractus (Plastomenus), 467, 472
francisce (Amyda), 511, §23
Galapagos Islands, origin of, 37
garmanti (Notomorpha), 269
Geographical distribution, 30
Geological distribution, 36
gibbi (Osteopygis), 128, 132
gigas (Atlantochelys), 190

(Protostega), 190
gilberti (Testudo), 398, 449
Glyptops, 45

belviderensis, 53

celatus, 52

depressus, §5

ornatus, 47

pervicax, 54

plicatulus, 47
gosseleti (Erquelinnesia), 160
grandeva (Chelonia), 216

(Procolpochelys), 216
grandevus (Puppigerus), 216
grangeri (Aspideretes), 486, 507
Graptemys, 288, 358

inornata, 358
gravis (Emys), 269

Ww

wn

552

gravis (Notomorpha), 269
Greensand of New Jersey, turtles of, 37
guttatus (Aspideretes), 486, 503
(Trionyx), 503
Gyremys, 287, 288
spectabilis, 288
Hadrianus, 368, 373
allabiatus, 383
corsonil, 374, 376
majusculus, 374
octonarius, 376
quadratus, 376
schucherti, 374, 382
tumidus, 374, 380
hadrianus, (Testudo), 376
halophila (Amyda), 511, 513
halophilus (Trionyx), 513
hatcheri (Baéna), 63, 92
haydeni (Echmatemys), 298, 313
(Emys), 308, 313
hebraica (Baéna), 87
hebraicum (Chisternon), 87
heckmani (Acherontemys), 222
Helochelys, 46
Helopanoplia, 483, 485
distincta, 485
hemispherica (Emys), 386
(Testudo), 386
hesperia (Clemmys), 290, 292
heteroglypta (Platypeltis), 537, 543
heteroglyptus (Trionyx), 543
hexagonata (Testudo), 398, 463
hilli (Pseudemys), 348
(Trachemys), 348
hoffmanni (Allopleuron), 209
Holcodus acutidens, 187
hollandi (Testudo), 398, 451
Homorophus, 225, 226, 260
insuetus, 260
Hoplochelys, 225, 226, 263
crassa, 263
paludosa, 266
saliens, 265
Hybemys, 287, 344
arenaria, 345
imbricaria (Basilemys), 231
imbricarius (Adocus), 231
(Compsemys), 231
impensa (Testudo), 398, 431
incisus (Cynocercus), 180
ingravata (Naiadochelys), 125
inornata (Chrysemys), 358
(Graptemys), 358
insculpta (Clemmys), 290, 295
(Testudo), 295
insignis (Plastomenus), 467, 469
insiliens (Thescelus), 95
insuetus (Homorophus), 260
insularis (Lembonax), 213
inusitata (Testudo), 398, 417
ischyros (Archelon), 202
(Protostega), 202
jarmani (Trachemys), 348, 351
jeanesi (Emys), 308
(Lytoloma), 156
(Propleura), 156
jeanesianus (Emys), 308
Judith River epoch, turtles of, 36
Kallistira, 225, 226, 267
costilata, 267
klettiana (Testudo), 398, 436
lacer (Adocus), 236, 241
lachrymalis (Plastomenus), 467, 472
Laramie, turtles of, 36
lata (Emys), 386
(Testudo), 386

INDEX.

laticaudata (Testudo), 398, 462
laticeps (Porthochelys), 180
laticunea (Testudo), 397, 402
latifrons (Eubaéna), 83
latilabiata (Echmatemys), 298, 339
(Emys), 298, 339
latiremis (Toxochelys), 166, 168
lativertebralis (Echmatemys), 298
(Emys), 298
Lembonax, 209, 212
insularis, 213
polemicus, 212
prophyleus, 214
propyleus, 214
Lepidochelys, 8, 9, 10, 216
leptomitis (Plastomenus), 467, 470
(Trionyx), 470
leslianus (Taphrosphys), 105, 111
(Prochonias), 111
leucopotamica (Platypeltis), 537, 546
leucopotamicus (Trionyx), 546
ligonia (Testudo), 397, 405
lima (Amyda), 511, 533
(Trionyx), 533

Limbs, structure of, 7, 9, 11, 12, 14, 16, 24

lineatus (Adocus), 236, 247
lineolatus (Compsemys), 247
longinuchus (Taphrosphys), 105, 108
lowi (Desmatochelys), 185
Lytoloma, 127, 154
angusta, 155, 157
crassicostatum, 154, 160
jeanesi, 156
platyops, 160, 162
wielandi, 157
Macrochelys, 222
floridana, 222
majusculus (Hadrianus), 374
manducans (Temnotrionyx), 534
marnochi (Cistudo), 362
(Terrapene), 360, 362
marshi (Archelon), 208
(Baéna), 61, 62
masculinus (Agomphus), 249, 255
mawii (Dermatemys), 284
megaulax (Echmatemys), 298, 301
(Emys), 301
Mesozoic, turtles of, 36
microglypha (Zygoramma), 259
Miocene, turtles of, 37
mira (Amyda), 511, 527
missuriensis (Polythorax), 100
mitchelli (Mosasaurus), 188
molaria (Erquelinnesia), 160
molopina, (Anostira), 481
molopinus (Plastomenus), 467, 481
molops (Bothremys), 115
(Taphrosphys), 105, 115
morrisie (Clemmys), 290
mortoni (Atlantochelys), 188
Mosasaurus mitchell, 188
multifoveatus (Plastomenus), 470, 474
Naiadochelys, 102, 125
ingravata, 125
naomi (Echmatemys), 298, 335
Naomichelys, 58, 101
speciosa, 101
nassau (Aspideretes), 486, 498
nebrascensis (Emys), 386
(Stylemys), 386, 392, 393
(Testudo), 386
Neck, structure of, 4, 8, 11, 13, 15, 20
neptunia (Protostega), 188
Neptunochelys, 187
tuberosa, 187
Neurankylus, 58, 93

Neurankylus eximius, 94
Niobrara epoch, turtles of, 36
niobrarensis (Stylemys), 437

(Testudo), 398, 437
nodosus (Taphrosphys), 105, 122
Notomorpha, 225, 226, 269

garmanii, 269

gravis, 269

testudinea, 303
Number of species, 2
obscura (Compsemys), 235
obscurus (Emys), 235
obtusa (Testudo), 398, 458
obtusus (Eupachemys), 458
octonarius (Hadrianus), 376
ocyrrhoé (Echmatemys), 298, 329
cedemia (Anostira), 479
cedemius (Plastomenus), 467, 479
ogmius (Basilemys), 226

(Compsemys), 226
oregonensis (Stylemys), 392

(Testudo), 392
Origin of turtles, 28
ornata (Anosteira), 279

(Anostira), 279
ornatus (Chelone), 210

(Glyptops), 47

(Peritresius), 210
orthopygia (Testudo), 398, 438

(Xerobates), 438
osborniana (Testudo), 398, 422
Osteology of turtles, 2
Osteopygis, 127

borealis, 128, 141

chelydrinus, 128, 136

emarginatus, 128, 129

erosus, 128, 138

gibbi, 128, 132

platylomus, 128, 129, 146

ponderosa, 152

repandus, 150

robustus, 128, 134

sopitus, 128, 141, 149
oweni (Emys), 386

(Testudo), 386
oxysternum (Agomphus), 249, 256

(Amphiemys), 256
pachylomus (Emys), 301, 302
Pachyrhynchus, 160
Paleotheca, 287, 343

polycypha, 343

terrestris, 344
paludosa (Hoplochelys), 266
pansa (Testudo), 398, 420
parva (Emys), 246
parviscutatus (Chelone), 220
parviscutum (Chelone), 220

(Puppigerus), 220
parvitecta (Chelone), 220

(Chelonia), 220
parvitectus (Puppigerus), 220
pectorale (Pleurosternum), 254
pectoralis (Adocus), 254

(Agomphus), 249, 254
Pelvis, structure of, 7, 9, 12, 14, 16, 21
pennata (Amyda), 511, 514
pennatus (Trionyx), 514
peragrans (Testudo), 398, 412
percrassa (Clemmys), 290, 294
Peritresius, 209

ornatus, 122, 210
pertenuis (Testudo), 398, 454
pervicax (Glyptops), 54
petrolei (Emys), 352

(Trachemys), 348, 352
petrosus (Adocus), 250

INDEX.

petrosus (Agomphus), 249, 250
(Emys), 250
Phylogeny of turtles, 27, 28
Pierre epoch, turtles of, 36
planimentum (Chelone), 154
Plastomenide, 466
Plastomenus, 466
acupictus, 467, 470
catenatus, 467, 470
coalescens, 488
communis, 467, 473, 451
corrugatus, 467, 473
costatus, 467
fractus, 467, 472
insignis, 467, 469
lachrymalis, 467, 472
leptomitus, 467, 470
molopinus, 467, 481
multifoveatus, 470, 474
cedemius, 467, 479
punctulatus, 467, 468
serialis, 537
tantillus, 467, 478
thomasi, 467, 474, 476, 537
trionychoides, 541 :
visendus, 467, 476
Platemys sulcatus, 104, 106
Platychelys, 59
platylomus (Osteopygis), 128, 129, 146
platyops (Euclastes), 162
(Lytoloma), 160, 162
(Rhetechelys), 162
Platypeltis, 483, 536
amnicola, 536, 540
antiqua, 536, 537
extensa, 537) 545
ferox, 11, 537) 548
heteroglypta, 5375 543
leucopotamica, 537, 546
postera, 537) 545
serialis, 536, 537
trepida, 536, 541
trionychoides, §37, 541
Plesiochelyide, 45
Plesiochelys belviderensis, 53
Plesiosauria, 30
Pleurodira, 12, 19, 20, 25, 34, 43, 102
Pleurosternida, 45
Pleurosternon, 46
Pleurosternum pectorale, 254
plicatulus (Compsemys), 47
(Glyptops), 47
polemicus (Lembonax), 212
polycypha (Emys), 343
(Palzotheca), 343
Polythorax, 58, 100
missuriensis, 100
ponderosa (Baéna), 271
(Catapleura), 152
(Osteopygis), 152
Porthochelys, 180
brown, 182
laticeps, 180
postera (Platypeltis), 537, 545

| potens (Protostega), 189, 198
| pravus (Adocus), 236, 242, 246

(Emys), 246
Preneural bone, 57
princeps (Prochonias), 114
(Taphrosphys), 114
prisca (Amyda), 511, 512
priscus (Trionyx), 512
Probaena, 58
sculpta, 58
procax (Toxochelys), 168, 176
Prochonias, 104

553

554

Prochonias enodis, 115

leshanus, 111

longinuchus, 108

princeps, 114

strenuus, 114

sulcatus, 106
Procolpochelys, 209, 215

grandeva, 216
Proganochelyida, 45
Proganochelys, 45
prophylaus (Lembonax), 214
Propleura, 127, 128

borealis, 141

jeanesi, 156

repanda, 150

sopita, 141, 162, 163
propylaus (Lembonax), 214
Protostega, 190

advena, 199

gigas, 190

ischyros, 202

neptunia, 188

potens, 189, 198

tuberosa, 187
Protostegida, 189
Pseudemys, 288, 356

bisornatus, 353

celata, 356

extincta, 356

hilli, 348
Pseudotrionyx, 19, 225
puercensis (Aspideretes), 486, 499
pulchra (Baéna), 92

(Boremys), 92
punctatus (Adocus), 236
punctiger (Trionyx), 546
punctulatus (Plastomenus), 467, 468
Puppigerus, 215

grandavus, 216

parviscutum, 220

parvitecta, 220
pusilla (Echmatemys), 298, 337
putnami (Terrapene), 360
quadrata (Testudo), 397, 410
quadratus (Hadrianus), 376
radiolata (Anostira), 281
radula (Amyda), 511, 517, 518
radulata (Anosteira), 281
radulina (Anostira), 281
radulus (Trionyx), 517, 518
rapiens (Thescelus), 97
repanda (Catapleura), 150

(Propleura), 150
repandus (Osteopygis), 150
Rhetechelys, 127, 161

platyops, 162
riparia (Baéna), 60, 76
robustus (Osteopygis), 128, 134
rugosus (Eupachemys), 458
sagatus (Aspideretes), 486, 497
salebrosa (Amyda), 511, 524
saliens (Hoplochelys), 265
saxea (Clemmys), 290, 294
schucherti (Hadrianus), 374, 382
sculpta (Probaéna), 58

(Trachemys), 348, 351
Scutes, horny, 18
scutumantiquum (Amyda), 511, 521

(Trionyx), 521
septaria (Echmatemys), 298, 319

(Emys), 319
serialis (Plastomenus), 537

(Platypeltis), 536, 537
serpentina (Chelydra), 223

(Testudo), 223
serrifer (Toxochelys), 168, 170, 172

INDEX.

shaughnessiana (Echmatemys), 298, 327
(Emys), 327
Shell, structure of, 2, 8, 10, 12, 14, 17, 18, 23
Shoulder-girdle, 6, 9, 11, 13, 16
sima (Baena), 71
singularis (Aspideretes), 486, 501
sinuosa (Basilemys), 229
Skull, structure of, 5, 9, 11, 13, 15, 19, 24
snoviana (Testudo), 438
snovianum (Caryoderma), 438
Soft-shelled turtles, 10
sopita (Chelone), 149, 155
(Osteopygis), 141
(Propleura), 141, 163
sopitus (Osteopygis), 128, 149
speciosa (Naomichelys), 101
spectabilis (Gyremys), 288
splendidus (Aspideretes), 486, 490
Staurotypus, 224, 225
stenopora (Toxochelys), 168, 172
stevensoni (Emys), 316
stevensoniana (Echmatemys), 298, 316
stevensonianus (Emys), 300, 316
strenuus (Prochonias), 114
(Taphrosphys), 105, 114
striatula (Zygoramma), 257
Stylemys, 369, 373, 385
calaverensis, 386, 396
capax, 38, 392
conspecta, 385, 393
| culbertsonu, 386
| nebrascensis, 386, 392, 393
niobrarensis, 437
oregonensis, 392
Suborders of turtles, 25
substricta (Alamosemys), 260
sulcatus (Platemys), 104, 105, 106
(Prochonias), 106
(Taphrosphys), 105, 106
Supernumerary scutes, 57
Syllomus, 209, 211
crispatus, 211
syntheticus (Adocus), 236, 242, 244
tantillus (Plastomenus), 467, 478
Taphrosphys, 102, 104
dares, 105, 120
leslianus, 105, 111
longinuchus, 105, 108
molops, 105, 115
nodosus, 105, 122
princeps, 114
strenuus, 105, 114
sulcatus, 105, 122
tardus (Agomphus), 249, 252
Temnotrionyx, 534
manducans, 534
Terrapene, 286, 288, 359
anguillulata, 364, 366, 367
canaliculata, 360, 363
eurypygia, 360, 364
marnochi, 360, 362
putnami, 360
terrestris (Emys), 344
(Paleotheca), 344
testudinea (Echmatemys), 298, 303
(Emys), 303
(Notomorpha), 303
Testudinide, 33, 367
Testudines, definition of, 43
Testudo, 367, 372, 373) 397
amphithorax, 397, 407
arenivaga, 398, 430
atascose, 398, 464
brontops, 397, 398, 400
campester, 398, 455
corsoml, 376

Testudo crassiscutata, 398, 459
culbertsonii, 386
cultrata, 397, 411
cyclopygia, 438
eda, 398, 450
emiliz, 398, 419
exornata, 397, 401
farri, 398, 418
gilberti, 398, 449
hadrianus, 376
hemispherica, 386
hexagonata, 398, 463
hollandi, 398, 451
impensa, 398, 431
insculpta, 295
Inusitata, 398, 417
klettiana, 398, 436
lata, 386
laticaudata, 398, 462
laticunea, 397, 402
ligonia, 397, 405
nebrascensis, 386
niobrarensis, 398, 437
obtusa, 398, 458
oregonensis, 392
orthopygia, 398, 438
osborniana, 398, 422
oweni, 386
pansa, 398, 420
peragrans, 398, 412
pertenuis, 398, 454
quadrata, 397, 410
snoviana, 438
serpentina, 223
thomsoni, 397, 400
turgida, 398, 453
undata, 398, 435, 438
vaga, 398, 414

Thalassemydida, 126, 127

Thecophora, 43

Thescelus, 58, 94
insiliens, 95
rapiens, 97

thomasi (Plastomenus), 467, 474, 476, 537
(Trionyx), 474

thomsoni (Testudo), 397, 400

timida (Chrysemys), 345

Toxaspis anguillulata, 364

Toxochelyidx, 163

Toxochelys, 163
bauri, 168, 178
brachyrhina, 168, 171
elkader, 168, 174
latiremis, 166, 168
procax, 168, 176
serrifer, 168, 170, 172
stenopora, 168, 172

Trachemys, 288, 347
bisornata, 348, 353
euglypha, 348, 350
hilli, 348
jarmani, 348, 351
petrolei, 348, 352
sculpta, 348, 351
trulla, 348, 355

trepida (Platypeltis), 536, 541

tricarinata (Baptemys), 275

Trionychida, 18, 35, 483

Trionychoidea, 10, 17, 20, 25, 43, 465

trionychoides (Anostira), 541
(Plastomenus), 541
(Platypeltis), 537, 541

Trionyx, 10, 17

INDEX. 555

Trionyx buiei, 534
cariosus, 515
cellulosus, 534
coalescens, 488
concentricus, §23
ferox, 548
foveatus, 486, 492
guttatus, 503
halophilus, 513
heteroglyptus, 543
leptomitus, 470
leucopotamicus, 546
lima, 533
pennatus, 514
priscus, 512
punctiger, 547
radulus, 517
scutumantiquum, 521
thomasi, 474
uintae€nsis, 519
vagans, 488, 490, 497
ventricosus, 516
Virgimianus, 515
tritor (Amyda), 511, 529
(Aspideretes), 529
trulla (Trachemys), 348, 355
tuberosa (Neptunochelys), 187
(Protostega), 187
tuberosus (Atlantochelys), 187
tumidus (Hadrianus), 374, 380
turgida (Testudo), 398, 453
turgidus (Agomphus), 249
(Emys), 249
uintaénsis (Amyda), 511, 519
(Trionyx), 519
uintensis (Echmatemys), 298, 342
undata (Baéna), 85, 87
(Testudo), 398, 435, 438
(Xerobates), 449
undatum (Chisternon), 85
vaga (Testudo), 398, 414
vagans (Aspideretes), 486, 497
(Trionyx), 488, 490, 497
variolosa (Basilemys), 226
variolosus (Adocus), 226
(Compsemys), 226
ventricosa (Amyda), 511, 516
ventricosus (Trionyx), 516

| Vertebra of turtles, 4, 8, 12

victa (Compsemys), 233
virginiana (Amyda), 511, 515
virginianus (Trionyx), 515
visendus (Plastomenus), 467, 476
vorax (Aspideretes), 486, 496
vyomingensis (Adocus), 271
(Dermatemys), 271
(Emys), 308
Wasatch epoch, turtles of, 37
wielandi (Lytoloma), 157
Writers on fossil turtles, 1
wyomingensis (Baptemys), 270
(Chrysemys), 308
(Dermatemys), 271
(Echmatemys), 298, 308
(Emys), 308, 313, 316, 337
Xenochelys, 224, 225, 226, 282
formosa, 282
Xerobates cyclopygius, 438
orthopygius, 438
undata, 449
Zygoramma, 225, 226, 257
microglypha, 259”
striatula, 257

———e

mnbhwWDN

An tWN

wd &

N Aw

map WH woh

MpwWN er

Lisl OF -PLATES

PLATE I.

FIGURES FROM DRAWINGS FURNISHED BY U. S. GEOL. SURVEY.

. Colpochelys kempi. Skull, upper aspect. X 7% U.S.N.M.

. Colpochelys kempi. Same skull, lower aspect. X %.

. Colpochelys kempi. Lower jaw of same skull, seen from above. X %.
. Colpochelys kempi. Same lower jaw, seen from side. X %.

. Platypeltis ferox. Lower jaw, lateral view. X %. U.S.N.M.

PLATE 2.

FIGURES FROM DRAWINGS FURNISHED BY U. S, GEOL. SURVEY.

. Colpochelys kempi. Skull, left side. 24. Same specimen as Figs. 1 to 4, Pl. 1.
. Colpochelys kempi. Left scapula and coracoid. x 7%. Yale Univ. coll. No. 638.

. Colpochelys kempi. Left humerus, dorsal aspect. X 7%.

. Colpochelys kempi. Same humerus, ventral aspect. * %.

. Colpochelys kempi. Left femur, dorsal aspect. * %.

. Colpochelys kempi. Same femur, ventral aspect. X %.

PLATE 3.

FIGURES FROM DRAWINGS FURNISHED BY U. S. GEOL. SURVEY.

. Platypeltis ferox. Skull, upper view. X %. U.S.N.M.
. Platypeltis ferox. Same skull, lower view. X %.
. Platypeltis ferox. Left scapula and coracoid. x %. cor, coracoid; peor, procoracoid

process; scap, scapula.

. Platypeltis ferox. Left humerus, dorsal view. 7%.

. Platypeltis ferox. Same humerus, ventral view. %.

. Platypeltis ferox. Left femur of same individual, dorsal aspect.
. Platypeltis ferox. Same femur, ventral aspect. X 24.

An

PLATE 4.

FIGURES FROM DRAWINGS FURNISHED BY U. S. GEOL. SURVEY.

. Podocnemis expansa. Skull, seen from above. X 7%. U.S.N.M.
. Podocnemis expansa. Same skull, from below. 0.5.
. Podocnemis expansa. Lower jaw of same individual. %. ang, angular; art, articular ;

dart, dermarticular, or prearticular; dent, dentary; spl, splenial.

. Podocnemis expansa. Lower jaw of same specimen from left side. 0.5. sur, sur-

angular.

. Podocnemis expansa, Skull seen from side. 0.5. Same individual as that of Fig. 1.

PLATE 5.

. Glyptops plicatulus. Costal; part of type. 1. No.6099 A. M.N. H.

. Glyptops plicatulus. Skull viewed from side * 1. Yale Univ. coll. No. 1357.

. Glyptops plicatulus. Skull, upper aspect. * 1. No, 336A. M.N.H.

. Glyptops plicatulus. Same skull, lower aspect. ™ 1.

. Glyptops plicatulus. Plastron. 0.25. Yale Univ. coll. No. 165. Drawing from U.S.

Geol. Survey.
PLATE 6.
Glyptops plicatulus. Carapace, skull and neck. 0.5. No. 336 A. M. N. H.

PLATE 7.

. Glyptops c@latus. First costal, first and second peripherals. 1 No. 1930 U. S. N. M.
. Glyptops celatus. Fragment of costal. * 1. No. 1930 U.S. N.M.

. Glyptops? belviderensis. Neural, lower surface. X I. Type in Colorado College coll.

. Glyptops belviderensis. Distal part of costal of type. * 1.

Probaéna sculpta. Plastron of type. 1. In Carnegie Mus.
Bo7

558

to

to

Wher

whe

aut

to

. Baéna
. Baéna

Baéna

Baéna

. Baéna
. Baéna

. Baéna

. Baéna
. Baéna
. Baéna

. Baéna
. Baéna
. Baéna

Baéna

. Baéna
. Baéna

Baéna

. Baéna
. Baéna

Baéna

Baéna

. Baéna
. Baéna
. Baéna

FOSSIL TURTLES OF NORTH AMERICA.

PLATE 8.

callosa. Plastron of type. 0.6. No. 330 Carnegie Mus.
marshi. Plastron of type. 0.47. Yale Univ. coll.

PLATE 9.
hatcheri. Carapace of type. ™ 4/9. In Carnegie Mus. (On the plate the size
is wrongly given as 4/7.)
PLATE 10.
hatcheri. Plastron of type. X04. In Carnegie Mus. (On the plate the size
is wrongly given as %.)
PLATE IT.
escavada. Carapace of type. X Y%. No.1203A.M.N.H.
escavada. Plastron of type. X %.
PLATE 12.

arenosa. Carapace. 0.5. No.5973A.M.N.H.

PEATE 12;

arenosa. Plastron of type. X 0.55. No.5973A. M.N.H.
sima. Skull, upper view. X 1. No.5971 A. M.N.H.
sima. Same skull, lower view. X 1.

PLATE I4.

arenosa. Part of skull, upper side. X 1. No.5973A.M.N. H.
arcnosa. Same skull, right side. X 1.

arcnosa. Same skull, lower side. X I.

sima, Skull of type, from right side. X 1. No.5971 A. M.N.H.
sina. Lower jaw of same individual, from above. X I.

sima. Same jaw, left side. X 1,

PLATE IS.

sima. Carapace of paratype. X 0.5. No.5965 A. M.N. H.

PLATE 16.
clara. Carapace of type. X 0.4. No.6075 A.M.N.H.
clara. Plastron of type. %X 0.4.

PLATE 17.

riparia, Skeleton of type viewed from above. X 0.4. No. 5977 A. M.N. H.

PLATE 18.
riparia. Skeleton viewed from below, with part of plastron removed. X 0.4.
No. 5977 A. M. N. H.
PLATE 19. 1

riparia. Skull of type, upper side. X1. No. 5977 A.M.N.H. i
riparia. Same skull, lower side. X 1.
riparia. Lower jaw of same skull. X 1.

Eubaéna cephalica. Skull forming type. X 1. No. 3110 Yale Univ. coll.

. Testudo vaga. Part of carapace, X0.5. No.1326A.M.N.H.
. Tesiudo orthopygia. Plastron of cotype of Xerobates cyclopygia. Cope. X 0.2. No. 1323

A. M.N. H.

. Testudo orthopygia. Carapace of cotype of Nerobates cyclopygia. X02. No. 1323

A. M.N. H.

AWN

SE

to N Ounf WN HE

N QDMA WD

2 aa

INDEX OF PLATES. 559

PLATE 20.

. Baéna emilie. Carapace of type. X04. No.1925 A. M.N. H.
. Baéna emilie. Plastron of type. 0.4.

PLATE 21.

. Eubaéna cephalica. Skull forming type, upper aspect. * 1. No. 2110 Yale Univ. coll
. Eubaéna cephalica. Same skull, lower aspect. % TI.

. Chisternon hebraicum, Skull, upper aspect. * 1. No. 5961 A. M.N.H.

. Chisternon hebraicum. Same skull, lower aspect. X 1.

PLATE 22.

Chisternon undatum. Carapace. 0.34. No. 3932 A. M.N. H.

PLATE 23.

_ Chisternon hebraicum. Skull, right side. x 1. No. 5961 A. M.N.H.

. Bothremys cooki. Skull of type, lower surface. 08. Type in Rutgers College, N. J
. Bothremys cooki. Lower jaw of type. X08.

. Osteopygis chelydrinus. Seventh peripheral of type. 0.75. No. 1131 A. M.N.H.

. Osteopygis chelydrinus. Same bone, inner surface. 0.75.

. Osteopygis chelydrinus. Second left peripheral of type, outer surface. X 0.75.

. Osteopygis chelydrinus. Same peripheral, inner surface. 0.75.

PLATE 24.

Thescelus insiliens. Carapace of type. * 4%. No.1108 A. M.N. H.

PLATE 25.

Thescelus insiliens. Plastron of type. X %. No. 1ro8A.M.N.H.

PLATE 26.

. Osteopygis gibbi. Rim of carapace of type, seen from below. * 0.23. Type in Yale
Drawing furnished by U.S. Geol. Surv.

. Osteopygis erosus. Sixth to tenth peripherals. * 0.27. No. 1130 A. M.N.H.

. Osteopygis borealis. Seventh to eleventh peripherals. 0.27. No. 1132 A. M. N. KR.

PLATE 27.

. Osteopygis gibbi. Carapace of type. * %->. Type in Yale Univ. coll.
. Osteopygis gibbi. Plastron of type. xX % +.

PLATE 28.

. Osteopygis chelydrinus. Third peripheral of type, outer surface. X 0.75. No. 113%
A.M.N. H.

. Osteopygis chelydrinus. Same peripheral, inner surface. * 0.75.

. Osteopygis chelydrinus. Lower jaw, upper surface. 0.75. Part of type.

. Osteopygis chelydrinus. Same jaw, right side. * 0.75.

. Lytoloma angusta. Lower jaw accompanying type peripheral. x 0.6. No. 1133 A. M.N.H.

. Lytoloma angusta. Peripheral forming type. * 0.6. No. 1133 A.M.N.H.

. Lytoloma wielandi. Upper surface of front of skull, forming type. 08. Yale Univ.
coll. Drawing from U.S. Geol. Surv.

. Lytoloma wielandi. Same specimen, lower surface. * 0.8.

PLATE 20.

. Lytoloma wielandi. Type fragment of skull, seen from behind. 0.8.

. Rhetechelys platyops. Skull forming type, upper surface. 0.4. Type in coll. Phila
Acad.

_ Rhetechelys platyops. Same skull, inferior surface. X 0.4.

560 FOSSIL TURTLES OF NORTH AMERICA.

Wd & LS)

to

SA AnNKRwWDH

whe

PLATE 30.

. Toxochelys sp. indet. Neurals 2 to 8, suprapygal, pygal and peripherals. X 0.6. Speci-

men in coll, Kansas Univ.

. Toxochelys sp. indet. Neurals and suprapygal of same specimen, lateral view. 0.6.

PLATE 31.

. Toxochelys brachyrhina. Skull forming type, lower surface. X 0.5. Type in coll. Kansas

Univ.

. Porthochelys laticeps. Carapace of type. X %. Type in coll. Kansas Univ.
. Porthochelys laticeps. Plastron of type. X %.

PLATE 32.

. Syllomus crispatus. Distal half of costal of type. X08. No.6134 A.M.N.H.
. Syllomus crispatus. Part of costal of type. X 0.8.
. Chelonia parvitecta. Costal forming type. 0.6. No.1318A.M.N.H. (On plate the

size is wrongly given as %.)

. Basilemys variolosa. Front of plastron. X 4%. From photograph by Lambe. Specimen

in coll. Geol. Surv. Canada.

. Basilemys imbricaria. Fragment of costal of type. X1. No.6102 A.M. N.H.
. Basilemys imbricaria. Fragment of costal of type. X 1.
. Basilemys imbricaria. Fragment of costal of type. X 1.

PLATE 33.

. Basilemys sinuosa. Carapace of type. 0.2. From photograph furnished by Field Mus.

Nat. Hist.

. Basilemys sinuosa. Plastron of type. X 0.2.

PLATE 34.

. Basilemys variolosa. Part of seventh peripheral of type, to show sculpture. x1. No.

1465 A. M. N. H.

. Compsemys victa. Fragment of costal, to show sculpture. I.
. Compsemys victa. Right eighth costal. xX 1. No. 6096 A.M. N. H.
. Compsemys obscura. Supposed second left costal. 1. Specimen in A. M. N. H.

Adocus punctatus. Upper surface of xiphiplastron of type. 0.25. Yale Univ. coll.

. Adocus beatus. Plastron. 0.25. Coll. A.M.N.H.
. Adocus beatus. First right peripheral of same specimen. X 0.5.
. Adocus lacer. Nuchal, 3 peripherals and part of costal. 0.25. No.1350A.M.N.H.

PLATE 35.

. Adocus punctatus. Carapace of type. 0.25. Yale Univ. coll.
. Adocus punctatus. Plastron of type. % 0.25.

PLATE 36.

. Adocus lacer. Plastron of type. 0.25. No.1350A.M.N.H.

. Adocus syntheticus. Plastron of type. X02. No. 1466 A.M. N.H.

. Adocus agilis. Plastron of type. X 0.2. No.1466A.M.N.H.

. Adocus petrosus. Right hypoplastron and two peripherals. 0.5. No.1482 A.M. N. H.

PLATE 37.

. Agomphus turgidus. Portion of plastron of type. X 0.5. No. 1481 A. M.N.H.

. Agomphus turgidus. Both hyoplastrals, lower surface. X05. No.1479 A.M.N.H.

. Agomphus turgidus. Same bones seen from in front. X 0.5.

. Agomphus turgidus. Eighth, ninth and tenth, right peripherals of type. X 0.5.

. Agomphus turgidus. Fourth neural and proximal ends of four costals of type. ™ 0.5.
. Agomphus petrosus. Two peripherals and part of costal of type. X05. No. 1482

A. M.N.H.

. Agomphus petrosus. Fourth and fifth right costals of type. X 0.5.

to

No

. Baptemys wyomingensis. Skull seen from above. ™* 1. No. 5067 A.M.N.H.
PLATE 30.
. Alamosemys substricta. Carapace of type. 0.25. No.1204 A. M.N.H.
. Alamosemys substricta, Plastron of type. X 0.25.
PLATE 40.
. Baptemys wyomingensis. Carapace. 1%. No.1494A.M.N. H.
. Naomichelys speciosa. Entoplastron forming type, outer surface. 0.75.
A.M.N.H.
. Naomichelys speciosa. Same bone, inner surface. X 0.75.
PLATE 4I.
. Baptemys wyomingensis. Carapace. X 0.28. No. 5067 A. M.N.H.
. Baptemys wyomingensis. Plastron of same specimen. 0.28.
PLATE 42.
. Baptemys fluviatilis. Carapace of type. 0.24. Geol. Dept. A. M. N. H.
. Baptemys fluviatilis. Plastron of type. 0.24.
PLATE 43.
. Anosteira ornata. Carapace. X 1. No. 6132 A.M.N.H.
. Anosteira ornata. Plastron. X 1.
PLATE 44.
1. Gyremys spectabilis, Carapace of type. 0.25. No.1171 A.M.N.H.
. Gyremys spectabilis. Plastron of type. X 0.25.
PLATE 45.

NOU B

. Clemmys morrisia.
. Clemmys hesperia.
. Clemmys hesperia.
. Clemmys hesperia.
. Clemmys hesperia.

. Agomphus pectoralis.
. Agomphus pectoralis.
. Zygoramma striatula,

. Zygoramma striatula,
. Zygoramma striatula.
. Zygoramma striatula.
. Hoplochelys crassa.

A.M.N,

. Hoplochelys crassa.
. Hoplochelys crassa.
. Hoplochelys crassa.
. Hoplochelys crassa.
. Hoplochelys crassa.

INDEX OF PLATES.

Both hyoplastra of type, lower surface.
Same bones seen from in front. 0.5.

X 0.5.

561

Inner surface of a bridge peripheral of type, showing end of rib.

x04. In A.M.N.H.
. Baptemys wyomingensis. Skull seen from above. 0.75.
. Baptemys wyomingensis. Same skull seen from below. 0.75.
. Baptemys wyomingensis. Same skull seen from side. » 0.75.

PLATE 38.

Both hypoplastra of type. ™ 0.5.
Three peripherals and part of costal of type.
Same bones, inner surface. X 0.5.

Sixth right peripheral of type, outer surface.

Fie

Same bone, inner surface. ™ 1.
Fourth or fifth peripheral of type, outer surface.
Same bone, inner surface. ™ 1.

In A. M. N. H.
085:

x I.

ool

No. 484 Yale Univ. coll.

No, 6091

Proximal ends of two costals of type, showing lateral carina.

Pygal of type. XI.

. Clemmys morrisie. Anterior lobe of plastron of type, upper surface.

A.M.N.H.

No. 6029 A. M. N. H.

Upper surface of left xiphiplastron.

Ninth left peripheral.

x 0.8.

x1.

No. 552 Univ. Cal. coll.

No. 6136

x 0.8. No. 6029

. Clemmys morrisie. Part of right side of hinder lobe of plastron, upper surface.

coll,

Left hyoplastron. Type. 1. No. 2219 Univ. Cal.
Right epiplastron. 1. No. 2179 Univ. Cal. coll.
First right peripheral. 1. No. 2179 Univ. Cal. coll.

X 0.8.

No. 6025 A. M. N. H.

562 FOSSIL TURTLES OF NORTH AMERICA.

8. Clemmys saxea. Pygal of type. x1. No. 2192 Univ. Cal. coll.

9. Clemmys saxea. Same bone, inner surface. ™ 1.

10. Clemmys saxea. Tenth left peripheral of type. % 1.

11. Echmatemys sp. indet. Skull, upper view. 1. Princeton Univ. coll.

12. Echmatemys sp. indet. Same skull, lower view. I.

13. Echmatemys sp. indet. Same skull, right side. X 1.

14. Echmatemys megaulax. Neural bone. x1. No. 1184 A.M.N.H.

15. Echmatemys megaulax. Peripheral bone. X 1. No.1184A.M.N.H.

16. Echmatemys testudinea. Third and fourth right peripherals. x 0.8. No. 1178 A. M.N.H. .
17. Echmatemys testudinea. Sixth costal. X08. No.1179 A.M. N.H.

PLATE 46.

1. Echmatemys euthneta. Part of plastron. X 0.96. No.1176A.M.N.H.

2. Chrysemys timida. Carapace of type. 0.62 of natural size. No. 10853 Princeton
Univ. coll.

3. Trachemys petrolei. Two epiplastra of different individuals. 0.8. Cotypes. No. 3933
A. M.N.H.

4. Trachemys petrolei. Nuchal bone accompanying cotypes. % 08.. No. 3933 A. M.N. H.

PLATE 47.

. Echmatemys wyomingensis. Plastron viewed from above. X 0.4. A.M.N.H.
. Echmatemys haydeni. Plastron viewed from, above. Xo0.4. A.M.N.H.

Now

PLATE 48.

1. Echmatemys stevensoniana. Carapace of type. Xx 0.4. No. 6084 A.M. N. H.
2. Echmatemys stevensoniana. Plastron of same specimen. 0.4.

PLATE 49.

1. Echmatemys arethusa. Carapace of type. 0.5. No.5920A.M.N.H.
2. Echmatemys arethusa. Plastron of type. 0.5.

PLATE 50.

1. Echmatemys shaughnessiana. Carapace of type. 0.375. No. 1069 A. M. N. H.
2. Echmatemys shaughnessiana. Plastron of type. 0.375.

PLATE 51.

1. Echmatemys naomi. Carapace of type. < 4%. No.5975A.M.N.H.
2. Echmatemys naomi. Plastron of type. X Me

PLATE 52.

1. Echmatemys callopyge. Carapace of type. X 0.3. No. 2087 A.M. N.H.
. Echmatemys callopyge. Plastron of type. 0.3.

Ny

PLATE 53.

1. Echmatemys uintensis. Carapace of type. 0.3. No. 11108 Princeton Univ. coll.

. Echmatemys uintensis. Plastron of type. 0.3.

iS)

PLATE 54.

. Deirochelys floridana. Nuchal forming type. X 0.8. In coll. Vanderbilt Univ.
. Deirochelys floridana? First costal. 0.8. In Vanderbilt Univ.

. Trachemys euglypha? Nuchal. X08. In Wagner Free Inst.

. Trachemys sculpta. Nuchal forming type. X08. In coll. Vanderbilt Univ.

. Trachemys sculpta. Third? costal. 0.8. In coll. Vanderbilt Univ.

and 7. Trachemys sculpta? Neural bone. X08. Same coll.

Trachemys sculpta? Costal bone. X08. Same coll.

. Trachemys sculpta? Costal bone. X 0.8. Same coll.

. Trachemys? jarmani. Nuchal forming type. X08. In coll. Vanderbilt Univ.
. Trachemys? jarmani? Right eighth peripheral. 0.8. Same coll.

. Trachemys? jarmani? Proximal end of costal. “X 0.8. Same coll.

. Pseudemys extincta. Nuchal forming type. X 0.8. Same coll.

90D DMANRWDND

H

me
em RH

Ar An hwWN YH

An bwnd He

INDEX OF PLATES. 563

PLATE 55.
Trachemys hilli. Carapace of type. 0.7. No. 2425 A. M.N.H.

PLATE 56.

. Trachemys bisornata. Part of carapace. X o8. Specimen in coll. Phila. Acad.

. Trachemys trulla. Part of epiplastra,lower surface. X 0.8. Type, No. 3934 A. M. N. H.
. Trachemys trulla. Same bones, upper surface. 0.8.

. Trachemys trulla. Right hyoplastron of type. X08.

. Trachemys trulla. Right hypoplastron of type. X08.

. Trachemys trulla, Left xiphiplastron of type. X 08.

. Terrapene putnami. Left hyoplastron forming type. 4%. In A.M.N.H.

. Terrapene putnami. Same bone showing lateral hinge. x 3%.

PLATE 57.

. Pseudemys celata. Nuchal.
. Pseudemys celata. Fifth left costal.
. Pseudemys celata. Left third peripheral.

Pseudemys celata, Left tenth peripheral.

. Pseudemys celata. Left hypoplastron.
. Pseudemys celata. Left first costal of smaller individual.

All figures slightly less than natural size. From type, No. 2508 U. S.N.M.

PLATE 58.

1. Terrapene marnochi. Carapace, side view. X 0.625. No. 3936 A. M.N. H.

to

to RwWN He

ty

ty

tN

. Terrapene marnochi. Same carapace, upper view.

PLATE 50.

. Hadrianus majusculus, Shell of the type. x 0.25. In Yale Univ. coll,
. Stylemys nebrascensis. Skull, upper side. X 1. Princeton Univ. coll.
. Stylemys nebrascensis. Same skull, lower side. 1,

. Stylemys nebrascensis. Egg. 1. A.M.N.H.

PLATE 60.

Hadrianus corsoni. Carapace. 0.375. No. 6027 A. M.N.H.

PLATE 61.

Hadrianus corsoni. Plastron. X 0.375. No. 6027 A. M. N. H.

PLATE 62,

. Stylemys nebrascensis. Carapace. X 0.5. No. 1433 A.M. N.H.
. Stylemys nebrascensis. Plastron of same shell. X 0.5.

PLATE 63.

. Stylemys capax. Carapace of type. X 0.28. No. 1357 A. M.N.H.
. Stylemys capax. Plastron of type. * 0.28.

PLATE 64.

. Stylemys conspecta. Carapace of type. 0.45. No.1358A.M.N.H.

PLATE 65.

. Testudo brontops. Carapace of type. 0.15. In Yale Univ. coll.
. Testudo brontops. Plastron of type. ™ 0.15.

PLATE 66.

. Testudo thomsoni. Front of plastron of type. 05. No. 3040 A.M.N.H
. Testudo thomsoni, Skull of type, upper side. X 0.8,

564 FOSSIL TURTLES OF NORTH AMERICA.

3. Testudo thomsoni. Skull of type, lower side. X 0.8.

4. Testudo thomsoni. Skull of type, left side. X 08.

5. Testudo thomsoni. Lower jaw of type, left ramus. X 0.8.

6. Testudo exornata. Distal end of left fifth costal of type. X08. Specimen in coll.
Geol. Sury. Canada.

7. Testudo exornata. Same costal, inner surface. X 08.

PLATE 67.

1. Testudo laticunea. Carapace of type. X 0.28. No. 1148 A.M.N.H.
2. Testudo laticunea. Plastron of type. X 0.28.

PLATE 68.
FROM PHOTOGRAPHS FURNISHED BY CARNEGIE MUS., PITTSBURG.

1. Testudo inusitata. Carapace of type. 0.5. No. 311 Carnegie Mus.
. Testudo inusitata. Plastron of type. X 0.5.

bo

PLATE 69.
FROM PHOTOGRAPHS FURNISHED BY DR, W. B. SCOTT.

1. Testudo farri. Carapace of type. % 0.375. No. 10486 Princeton Univ. coll.
2. Testudo farri Plastron of type. X 0.375.

PLATE 70.

1. Testudo emilie, Carapace of type. X 0.4. No. 6135 A.M. N.H.
2. Testudo emilie. Plastron of type. X 0.4.

PLATE 71.

1. Testudo pansa. Carapace of type. X 1/7. No. 5869 A. M.N.H.
. Testudo pansa. Plastron of type. X 1/7.

to

PLATE 72.

Testudo osborniana, Carapace of type. X 0.2. No. 5868A.M.N.H.

PLATE 73.
Testudo osborniana. Plastron of type. 0.2. No. 5868 A. M.N.H.

PLATE 74.
Testudo osborniana, Carapace, limbs, head, neck and internal skeleton. x 0.2. No. 5870
A. M.N. H.
PLATE 75.

1. Testudo osborniana. Carapace. X 0.4. No. 5871 A.M. N.H.
. Testudo osborniana, Plastron. X 04.

to

PLATE 76.

Testudo impensa. Carapace of type. X %. No.5867A.M.N.H. The central portions
are crushed inwards and d’sturbed.

PLATE 77.
Testudo impensa. Plastron of type. * %. No. 5867 A. M.N. H.

PiatTeE 78.

1. Testudo orthopygia. Plastron of type. X 0.25. No. 3929 A.M. N.H.
2. Testudo orthopygia. Rear of shell. x %. No.1325A.M.N.H.

mbhwhy

to

wn

kwh eH

Nw

. Testudo

. Testudo

. Testudo

. Testudo
. Testudo
. Testudo
. Testudo

Testudo

Testudo

. Testudo
. Testudo

. Testudo

1. Plastom

nN

INDEX OF PLATES. 565

PLATE 79.

orthopygia. Carapace. 0.4. Mostly from No. 2415, but partly from Nos. 3931
and 2320 A. M.N.H. Represents young individuals called by Cope Nerobates

cyclopygia.
orthopygia. Plastron. 0.4. Mostly from No. 2415, but partly from No. 3931
A.M.N.H. Form called by Cope Xerobates cyclopygia.

PLATE 80.

orthopygia. Shell, side view. 0.4. Restored from same specimens as figures
of Plate 70.

gilberti. Skull of type, seen from above. X 0.75. From type in coll. Univ. Kansas.

gilberti. Same skull seen from below. % 0.75.

gilberti. Same skull, right side. 0.75.

gilberti. Lower jaw of same skull. X 0.75.

PLATE 8&1.
orthopygia. Carapace. ™ 0.25. No. 6108 A. M.N.H.

PLATE 82.

orthopygia. Plastron. X 0.25. No.6108 A. M.N.H.

PLATE 83.
FROM PHOTOGRAPHS FURNISHED BY CARNEGIE MUS., PITTSBURG.
ede. Carapace of type. X03. No.1535 Carnegie Mus.
ede. Plastron of type. 0.3.
PLATE 84.
FROM PHOTOGRAPHS FURNISHED BY CARNEGIE MUS., PITTSBURG.

hollandi. Carapace of type. X %. No.1561 Carnegie Mus.

. Testudo hollandi. Plastron of type. X %.
PLaTE 85.
. Plastomenus costatus. Costal bone. Slightly reduced. No. 6131 A. M. N. H.
. Plastomenus costatus. Right xiphiplastron. Slightly reduced. No. 6131 A. M. N. H.
. Plastomenus molopinus. Carapace. 0.6. No. 5941 A. M.N.H.
Prate 86.
REPRODUCTION OF FIGURES BY COPE.
. Plastomenus catenatus. Fragment of costal. * 1. No.1138U.S.N.M.
. Plastomenus? leptomitus. Fragment of costal. & 1. No.1113U.S.N.M.
. Plastomenus? lachrymalis, Fragment of costal. X 1. a, view of edge of fragment.
. Plastomenus? fractus. Fragments of costals. 1. Types lost. w, 4, the proximal
end of a costal, showing both surfaces; y, s, fragments of two costals.
. Plastomenus corrugatus. Part of left hypoplastron. ™ 1. Original lost. .
. Plastomenus communis. Two peripherals. 1. a, seen from above; b, view of edge.
Type. No.1132U.S.N.M.
. Plastomenus communis. Two peripherals of type. X 1.
. Plastomenus communis. Fragment of hyoplastron of type. ™ 1.
. Amyda cariosa. Neural. X1. Type. No.2575U.S..N.M.
. Amyda cariosa. Fragment of costal of type. X I.
. Amyda radula. Fragment of costal of type. 1. No. 2581 U.S. N.M.
. Amyda radula, Fragment of costal of type. ™ I.

PLATE 87.

enus visendus. Carapace. 0.5. Type. No. 1895 A. M.N.H.

. Plastomenus visendus. Plastron of same specimen. X 0.5.

566 FOSSIL TURTLES OF NORTH AMERICA.

I.
2
3

nun p

bo

to

we Nom

wine

w

PLATE 88.

Conchochelys admirabilis. Skull of type, view from above. X %. No.6090 A. M.N. H.
Conchochelys admirabilis. Same skull, seen from below. X %.

. Conchochelys admirabilis. Same skull, seen from right side. X ¥%.

Helopanoplia distincta. Fragment of costal type. <1. U.S.N.M.
Helopanoplia distincta. Portion of plastral bone of type. X1. U.S.N.M.

. Aspideretes coalescens. Fragment of costal. X 1. Shows the sculpture. From photo-

graph furnished by L. M. Lambe.

. Aspideretes splendidus. Portion of distal third of second costal of type. 1. No. 3952

A.M.N.H. Shows character of sculpture.
Aspideretes splendidus. Portion of distal end of fourth costal of type. X 1.

. Aspideretes splendidus. Portion of proximal half of third costal. X 1.

PLATE 80.

. Aspideretes foveatus. Carapace. X 0.5. From photograph by L. M. Lambe. Specimen

in coll. Geol. Surv. Canada.

Aspideretes foveatus. Right hypoplastron. x 1. From drawing by L. M. Lambe. Speci-

men in coll, Geol. Surv. Canada.

PLATE 90.

Aspideretes coalescens. Carapace. 0.25. From photograph by L. M. Lambe. Speci-
men in coll. Geol. Surv. Canada.

. Aspideretes beecheri. Carapace. X 4. No. 2358U.S.N.M.

PLATE QI.

Aspideretes splendidus. Carapace of type. 0.28. No. 3952 A. M.N.H.

PLATE Q2.

Aspideretes beecheri. Carapace and part of neck, limbs and tail of type. X 0.25. Speci-

men in Yale Univ. coll. Photograph by Wieland.
Aspideretes beecheri. Plastron of type. 0.25. Photograph by Wieland.

PLATE 93.

Aspideretes sagatus. Carapace of type. X %. No.1201 A. M.N. H.

Aspideretes sagatus. Portions of neurals and costals, to show sculpture. X 1. From type.
. Aspideretes sagatus. Distal portion of a costal. X 1. From type.

PLATE 4.

Aspideretes puercensis. Carapace of type. X05. No.1202A.M.N.H.
Aspideretes puercensis. Portion of first costal of type, taken near center. X I.
Aspideretes puercensis. Portion of proximal end of third costal of type. X 1.

PLATE 95.
Aspideretes ellipticus. Carapace of type. X04. No.1117A.M.N.H.

. Aspideretes ellipticus. Portion of fifth neural and of fifth and sixth costals of type.

= <1. To show character of sculpture.
Aspideretes ellipticus. Portion toward distal.end of fifth costal of type. X 1.

PLATE 96.

Aspideretes beecheri. Portions of two costals of type, to show sculpture. X I.
Aspideretes beecheri. Portion of costal to show sculpture. X 1. No. 2358U.S.N.M.
Aspideretes vagans. Type fragment of costal. x1. No.1847A.M.N.H.

Amyda? halophila. Neural and part of costal of type. x1. No.1476A.M.N.H.
Amyda? halophila. Fragment of costal. X1. No.1476A.M.N.H.

. Amyda? pennata. Costal forming type. X 1. No. 1165 A.M.N.H.

Amyda? virginiana. Portion of costal of type. 1. In coll, Maryland Geol. Surv.
Amyda? virginiana. Second portion of costal of type. X 1. In coll. Maryland Geol. Surv.

Ankh WN

boo

inl

ae)
wh

HOO MN ANA W

INDEX OF PLATES. 567

PLATE 97.

. Aspideretes grangeri. Carapace of type. X 0.4. No. 3942 A.M.N.H.
. Amyda? prisca. Proximal end of costal. x1. No. 2401 A. M. N. H.

. Amyda? prisca. Distal end of costal. 1. No.2401 A.M.N.H.

. Amyda? prisca. Supposed part of nuchal. xX 1. No. 2401 A. M.N. H.
. Amyda? prisca. Supposed last costal. xX 1. No.2401 A.M. N.H.

. Amyda? prisca. Portion of costal. xX 1. No. 2401 A.M.N.H.

PLatTE 08.

. Amyda ventricosa. Distal end left hypoplastron of type. xX 1. No.1112 U.S.N.M.
. Amyda ventricosa. Distal end of left hypoplastron of another individual. 1. No. 1112

U.S.N.M.

. Amyda ventricosa. Undetermined fragment of same lot.
. Amyda ventricosa. Distal end of costal plate of same lot.
. Amyda ventricosa. Portion of costal of small individual of same lot.

Amyda ventricosa. Fragment of costal of same lot.
Amyda concentrica. Fragment of costal of type. x1. In A.M.N.H.

. Amyda concentrica. Fragment of costal of type.

. Amyda concentrica. Fragment of costal of type.

. Amyda concentrica, Fragment of costal of type.

. Amyda lima. Portion of costal forming type. 1. In A.M.N.H.

. Amyda buiei. Fragment of costal. x1. In A.M.N.H.

. Platypeltis serialis. Left half of carapace. X 1. No.6014A.M.N.H.

. Platypeltis heteroglypta. Part of middle of fifth costal of type. 1. No. 1039 A.M. N. H.

PLATE 99.

. Amyda equa. Carapace of type. X 0.31. U.S.N.M.

2. Amyda equa. Third neural and costal of type. ™ 1.

hw dbx

. Amyda equa. Portion of middle of costal. 1.

PLATE 100.

. Amyda uintensis. Plastron of type. 0.27. Coll. Phila Acad.
. Amyda scutumantiquum. Right hyoplastron and hypoplastron of type. 0.5. No. 1035

A. M.N. H.

. Amyda scutumantiquum. Part of first and second neurals and first and second costals

of type. XI.

. Amyda scutumantiquum. Part of distal end of a costal of type. X I.

PLATE IOI.

. Amyda scutumantiquum. Carapace of type. 0.3. No. 1035 A.M. N.H.
. Platypeltis heteroglypta. Carapace of type. X 0.38. No. 1039 A. M.N.H

PLATE 102.
Amyda francisce. Carapace of type. X04. No. 5936A.M.N.H.
PLATE 103

Amyda francisce. Plastron of type. X0.4. No. 5936 A.M.N. H.

PLATE 104.

. Amyda salebrosa. Carapace of type. 0.3. No. 3941 A. M.N. H.

. Aspideretes puercensis, Right hyoplastron and hypoplastron. X 0.6. No. 1202 A. M. N. H.
. Aspideretes puercensis. Portion of right xiphiplastron of type. 0.6.

. Axestemys byssina. Left xiphiplastron. 0.43. U.S.N.M.

PLATE 105.

. Amyda mira. Carapace of type. 0.5. No.6130 A. M.N.H.
. Temnotrionyx manducans. Part of right maxilla of type, side view. %* I. No. 5929

A. M.N. H.

_ Temnotrionyx manducans. Same maxilla, showing grinding surface. * 1.

568 FOSSIL TURTLES OF NORTH AMERICA.

PLATE 106.

Amyda mira. Plastron of type. X 0.7.

PLATE 107.

1. Amyda egregia. Carapace of type. X04. No.1186A.M.N.H.
. Amyda egregia. Part of fourth and fifth neurals and fourth and fifth costals. Type. X 1.

N

PLATE 108.
Amyda crassa. Carapace of type. X 0.32. No. 3887 A. M.N.H.

PLATE 109.

. Platypeltis serialis. Carapace. X 0.75. In A. M.N.H.

. Platypeltis serialis. Plastron. 0.75. No.5944 A. M.N. H.

. Platypeltis serialis. Plastron. X 0.75. No.6014 A.M.N.H.

. Platypeltis serialis. Distal end of costals. 1. No.5044A.M.N.H.

&wWNR

PLATE IIo.

1. Platypeltis trionychoides. Carapace. X 0.75. No. 5938A.M.N.H.
. Platypeltis trionychoides. Plastron. X 0.75. No. 5938A.M.N.H.

to

PLATE III.

1. Platypeltis postera. Carapace of type. 0.32. No.6133A.M.N. H.
2. Platypeltis postera. Plastron of type. X 0.32.

PLATE I12.

Platypeltis extensa. Carapace of type. X04. No.5951 A.M.N.H.

PLATE 113.

. Platypeltis leucopotamica, Carapace. X %. No.6045 A. M.N.H.
. Platypeltis leucopotamica. Part of third neural and costal. x 1. No. 6045 A.M.N.H.
. Platypeltis leucopotamica. Distal end of second costal. X 1. No.6045 A. M.N.H.

WH H

’

Fossil Turtles Plate 1

eee
_

Figs. 1 to 4. Colpochelyskempi. » 4. Page 8.
Fig. 5. Platypeltisferox. » 3. Page 11.

Fossil Turtles Plate 2

Colpochelys kempi. < 3. Page 8.

Fossil Turtles Plate 3

Platypeltis ferox. % Page 11.

Fossil Turtles Plate 4

Podocnemis expansa. Figs, 1 and 2, « 3; Figs. 3, 4, and 5, 4. Page 14.

Fossil Turtles Plate 5

Glyptops plicatulus. Figs. 1 to 4,1; Fig. 5,4. Page 47.

Fossil Turtles Plate 6

Fossil Turtles Plate 7

Figs. 1 and 2. Glyptopscelatus. 1. Page 52.
Figs. 3 and 4. Glyptops? belviderensis. »< 1. Page 53.
Fig. 5. Probaénasculpta. » 1. Page 58.

1
4 :
.
.
r i
25 = 4s tom Sid = So 7

Plate 8

Fossil Turtles

‘zg aseg
‘og a8eg

“L¥0 X

‘g'0

V4
aN

‘Iysieul Bude g
‘esoj[eo Budeg

“i

Fossil Turtles Plate 9

Baénahatcheri. <j. Page 63.

Fossil Turtles Plate ro

2

Baéna hatcheri. « 4% Page 63.

Fossil Turtles Plate 11

Page 65.

4.

vv
w

Baéna escavada.

Fossil Turtles Plate 12

Baéna arenosa. }. Page 68.

Fossil Turtles Plate 13

Page 68.
Page 72.

0.55.
SG. a:

Baéna sima.

Baéna arenosa.

Fig. 1.
Figs. 2 and 3.

Fossil Turtles Plate 14

Figs. 1 to 3. Baénaarenosa. » 1. Page 69.
Figs. 4 to 6. Baénasima. 1. Page 72.

oe

a

nu

Fossil Turtles Plate 15

Baénasima. 4. Page 73.

Fossil Turtles Plate 16

Page 74.

xX ¢.

Baéna clara.

5 ouste
iM ae

Fossil Turtles Plate 17

ae

Baénariparia. %. Page 76.

Fossil Turtles
Plate 18

Baénariparia. 2 Page 77.

Fossil Turtles Plate 19

Figs. 1to 3. Baénariparia. 1. Page 78. Fig. 5. Testudo vaga. 4. Page 415.
Fig. 4. Eubaénacephalica. >< 1. Page 82. Figs. 6 and 7. Testudo orthopygia. 4. Page 446.

Fossil Turtles Plate 20

Page 80.

x 2.

Baéna emiliz.

Fossil Turtles Plate 21

Figs. 1 and 2. Eubaénacephalica. 1. Page 82.
Figs. 3 and 4. Chisternonhebraicum. 1. Page 88.

-

Plate 22

Fossil Turtles

Page 85.

* 0.34.

Chisternon undatum.

——

Fossil Turtles Plate 23

Fig. 1. Chisternon hebraicum. 1. Page 88. Figs. 2 and 3. Bothremys cooki. 4. Page 103.
Figs. 4 to 7. Osteopygis chelydrinus. 3. Page 136.

Plate 24

Fossil Turtles

Page 95.

x 4.

iens.

il

ins

Thescelus

P=

Fossil Turtles Plate 25

Plate 26

Fossil Turtles

‘CEI

aseqg ‘Ez'o XxX

‘ber a3eg
‘iqqis stshdoa3soO ‘I ‘SI

"Leo XK

*sijeaiog sisAdoajso “€ “S1q
‘6Er aseq ‘Leo ‘snsoja sIsAdoojsO ‘2 ‘31

Plate 27

Fossil Turtles

‘cEI a8eg

"+2 X

‘Iqqis stsAdoajsC

Fossil Turtles or
ate 28

Figs. 1 to 4. Osteopygis chelydrinus. 3. Page 136.
Figs. 5 and6. Lytolomaangusta. 3. Page 155.
Figs. 7 and 8. Lytoloma wielandi. %. Page 157.

Plate 29

Fossil Turtles

‘zg

aseq % X

‘sdoAjeld sAjayoaja yy

‘€ pue z ‘ssty

*‘IPUR[IIM BUIO[OJAT “IBY

| 2

Fossil Turtles
Plate 30

7
Toxochelys sp.indet. 2. Page 164.

_

Plate 31

Fossil Turtles

‘Ihr a8eq “% X ‘eurpsAyoesq SAJOYIOXOY, ‘1 ‘BY

‘ogi o8eg *% X ‘sdaone, séjayooyIIog “€ puez‘ssIy

Plate 32

Fossil Turtles

Page 226.

1
3°

Fig. 4. Basilemys variolosa.

Page 211.

es
Se

\

tus. x

ispa

Figs. 1 and 2. Syllomus cr

Page 231.

I.

Figs. 5 to 7. Basilemys imbricata.

Fig. 3. Chelonia? parvitecta.

Fossil Turtles Plate 33

Page 2209.

Xx t.

Basilemys sinuosa.

Fossil Turtles Plate 34

Fig. 1. Basilemys variolosa. 1. Page 226. Fig. 5. Adocus punctatus. 3. Page 238.
Figs. 2 and 3. Compsemys victa. » 1. Page 234. Fig. 6. Adocus beatus. 4. Page 240.
Fig. 4. Compsemys ? cbscura. 1. Page 235. Fig. 7. Adocus beatus. 1. Page 240.

Fig. 8. Adocus lacer. 4. Page 242.

Plate 35

Fossil Turtles

*snje}ound snoopy

=

oe

ve

Fossil Turtles Plate 36

Sing

'
\
| p i en acl Bee les
\
‘a
>

Fig. 3. Adocus agilis. 4, Page 246.
1, Page 250.

Fig. 4. Agomphus petrosus.

Fig. 1. Adocus lacer. 4. Page 241.
Fig. 2. Adocus syntheticus. >< 3. Page 244.

Fossil Turtles Plate 37

Figs. 1 to 5. Agomphus turgidus. < 3. Page 249. Figs. 8 and 9. Agomphus pectoralis. >< 2. Page 254.
Figs. 6 and 7. Agomphus petrosus. >< 4. Page 250. Fig. 10. Zygorammastriatula. > 2. Page 258.

Figs. 11 to 13. Baptemys wyomingensis. >< 3. Page 273.

Fossil Turtles Plate 38

i [7 nn ne
J Y |
} joey
| See {
| nak fe /
/

i

Figs. 1 to 3. Zygoramma striatula. > 3. Page 257. Figs. 4 to 9. Hoplochelys crassa.
Fig. 10. Baptemys wyomingensis. I. Page 273.

Plate 39

Fossil Turtles

‘ogz a8eg

bw

*eyTI}sqns sAUIasOWeLy

Fossil Turtles Plate 40

Fig. 1. Baptemys wyomingensis. >< 4, Page 271.
Figs. 2 and 3. Naomichelys speciosa. > }. Page tot.

Plate 41

Fossil Turtles

‘tle ase

*gz'0

‘sisuasurmioAm sAuajdeg

Plate 42

Fossil Turtles

‘LLe aseg

“bz'0

‘stterany shuiaydeg

Plate 43

Fossil Turtles

‘6Lz a8eg

"I

Vv

7

\

“eyeUIO PII9}SOUY

Fossil Turtles Plate 44

Vv

Gyremys spectabilis. >< j. Page 288.

Fossil Turtles Plate 45

Figs. 1 to3. Clemmys morrisiz. » +, Page 290. Figs. 11 to 13. Echmatemys sp. indet. 1. Page 297.
Figs. 4to 7. Clemmys hesperia. » 1. Page 292. Figs. 14 and 15. Echmatemys megaulax. < 1. Page 302.
Figs. 8 to 10. Clemmys saxea. 1. Page 294. Figs. 16 and 17. Echmatemys testudinea. %. Page 303.

Plate 46

Fossil Turtles

‘She adeg

‘z9°0

“ESE adedg

“g'0

‘aporjad sAwayoe1 T,

‘epi sAurashiyd ‘2 31q 'GOk adedg

‘y pue € 's31y
‘ejouY Na SAWaJeWIYIA “1 BY

‘960 >

Plate 47

Fossil Turtles

‘yIE adeq ‘§
‘ole aBeq “%

‘uapAey SAua}eWIYyIY *% “Sy

‘sisuaSurmoAM SAwayeuyyg “13

Tash

=

a

Fossil Turtles

Plate 48

‘Lit Oded |e oS

“eURTUOSUAAa}S SAA} BUY

Fossil Turtles Plate 49

Echmatemys arethusa.

Plate 50

Fossil Turtles

‘LeE aseg

Plate 51

Fossil Turtles

“GEE aSeq “FX

"tmioeu SAUWIa}e WY IA

Plate 52

Fossil Turtles

‘ob€ aseg

‘0

‘asAdoj[eo SAWIa}eWIYIA

Plate 53

Fossil Turtles

‘tbe aseg

“Eo

“sISUd}UTUN SALA} BWIA

Plate 54

Fossil Turtles

- —_ - -
eee

Vv
\

Figs. 4 to 9. Trachemys sculpta.

Page 346.

Page 351.
Fig. 13. Pseudemys extincta.

4.

/
x

Figs. 1 and 2. Deirochelys floridana.

Fig. 3. Trachemys euglypha ?

Figs. ro to 12. Trachemys jarmani.

X ¢.

Page 356.

4
Ro

\
Aw

Plate 55

Fossil Turtles

‘gbE aseq

*L'O

Pans

“TTY sAtuayoes Ly

Fossil Turtles Plate 56

Page 355.

4
Se

Page 354. Figs. 2 to 6. Trachemys trulla.

Figs. 7 to 8. Terrapene putnami.

Trachemys bisornata.

Fig. 1.

_

a

Fossil Turtles

Pseudemys celata.

x

I.

Page 356.

Plate 57

Fossil Turtles Plate 58

Terrapene marnochi. >< 3. Page 362.

Fossil Turtles Plate 59

Fig. 1. Hadrianus majusculus. » 4. Page 374.

Figs. 2 to 4. Stylemysnebrascensis. 1. Page 388.

Fossil Turtles

Hadrianus corsoni.

x 3.

Page 377.

Plate

60

Fossil Turtl
ossil Turtles Plate 61

Fossil Turtles Plate 62

Page 388.

4.

ww
oS

Stylemys nebrascensis.

Fossil Turtles Plate 63

Page 392.

x 0.28.

Stylemys capax.

Plate 64

Fossil Turtles

*€6E aseq

Sto

Vv
a

*ey9adsuod SAUIaTAIS

Plate 65

Fossil Turtles

*g6€ o8eq ‘SI'O X

*sdojuoiq opnisay

Fossil Turtles
Plate 66

Figs. 1 to 5. Testudothomsoni. Fig.1, 4; Figs.2to5, x
Figs. 6 and 7. Testudoexornata. #. Page 4or.

Plate 67

Fossil Turtles

‘tov a8eq ‘gz'o X

*BOUNII}E] OpNysa y,

Plate 68

Fossil Turtles

‘Liv aBeq “% X

“BJ e}ISNUI OpNysa |,

Fossil Turtles

Plate 69

x 3. Page 418.

Testudo farri.

.
OS re 7 - r

Plate 70

Fossil Turtles

‘61y aBeq “3 X

‘xIIula Opnisa

tae

Plate 71

Fossil Turtles

‘ozb a8eg

4
T

x

‘esued opnjso J,

Fossil Turtles
Plate 72

Testudo osborniana. 4. Page 423.

Fossil Turtles
Plate 73

es diets St

1 Uea be

Testudo osborniana. x 4. Page 424.

Fossil Turtles
Plate 74

Testudo osborniana. 4. Page 427.

:

Plate 75

Fossil Turtles

‘Ozh aseq ‘3 >

*eueluloqso opnysa Jf,

Fossil Turtles

Testudo impensa.

Plate

to)

7

Fossil Turtles Plate 77

Testudoimpensa. X %. Page 433.

Fossil Turtles
Plate 78

Testudo orthopygia. Fig.1, 4; Fig.2, 4. Page 440.

Plate 79

Fossil Turtles

j

‘gby aseq ‘% X

*e13 Adoyjs0 Opnysa y,

Plate 89

Fossil Turtles

<< #4 Page 448.
xX 9. Page 449.

Fig. 1. Testudo orthopygia.
Figs. 2 to 5. Testudo gilberti.

Fossil Turtles Plate 81

Testudo orthopygia. }. Page 448.

Fossil Turtles

Plate 82

la.

Testudo orthopyg

Fossil Turtles Plate 83

Page 450.

xX 0.3.

Testudo ede.

Plate 84

Fossil Turtles

‘Sh o8eq ‘fF X

‘Ipuel[oy opnysay,

; _
as _
-
S 7 a
a

Fossil Turtles
Plate 85

Figs. 1 and 2. Plastomenus costatus. > I. Page 468.
Fig. 3. Plastomenus molopinus. 3. Page 482.

Fossil Turtles

Fig. 1. Plastomenus catenatus. » I.
Fig. 2. Plastomenus? leptomitus.

Page 470.
1. Page 471.

Figs. 3 and 3a. Plastomenus? lachrymalis. > 1. Page 472.

Fig. 4. Plastomenus? fractus. > I.

Page 472.

Fig. 5. Plastomenus corrugatus. 1. Page 473.
Figs. 6a and 6b to 8. Plastomenus communis. 1.
Figs.g and 10. Amyda? cariosa. 1. Page 516.
Figs. 11 and1z. Amydaradula. 1. Page 517.

Plate 86

Page 473.

Plate 87

Fossil Turtles

Plastomenus visendus.

Fossil Turtles
Plate 88

Figs. 1 to 3. Conchochelys admirabilis. > 4. Page 483. Fig. 6. Aspideretes coalescens. 1. Page 490.
Figs.4 and 5. Helopanopliadistincta. 1. Page 485. Figs. 7 to 9. Aspideretes splendidus. > I. Page 491.

ossil Turtles
Plate 89

"Jae hy, p
SOI INS 2

Ba fe r A

Aspideretes foveatus. Fig.1, > 3; Fig.2, x I. Page 487.

Plate 90

4, Page 490.

Fig. 1. Aspideretes coalescens.
Fig. 2. Aspideretes beecheri. 4. Page 493.

Plate gt

‘o6y aSeq ‘gz'o X = ‘snprpuads sajaiepridsy

‘ossil Turtles

y

*

hi

Fossil Turtles
Plate g2

Aspideretes beecheri. 4. Page 492.

Plate 93

Fossil Turtles

tS

we
So

pan

Page 407.

pots

Figs. 2 and 3,

,

4

Vv
“N

Aspideretes foveatus. Fig. 1,

Plate 94

Aspideretes puercensis. Fig. 1,

Fossil Turtles

Sn ee ee ee ee oe ee ee

Plate 95

Fossil Turtles

Fig. 1,

ipticus.

Aspideretes ell

Fossil Turtles

Plate 96

i
z
>
:
.
.
i
a
4
;
4
‘
.
7
.
}
|
:

i

+e

xP

wet
‘=
sa
Figs. 1 and 2. Aspideretes beecheri. 1. Page 402. Figs. 4and 5. Amyda? halophila. x 1. Page 513.
Fig. 3. Aspideretes vagans. > 1. Page 497. Fig. 6. Amyda? pennata 1. Page 514
Figs. 7and 8. Amyda? virginiana. 1. Page 515.

r

ee ae ae Troe oe ale = a —

Plate 97

Fossil Turtles

‘e1G o8eq ‘I X
‘LoS a8eq ‘§ X

‘eostid ¢ epAuly °9 0} Z’s31yy
‘LiIasueis sojoiopidsy ‘1 ‘317

Fossil Turtles Plate 98

“ * ay 7
, Figs. 1 to 6. Amydaventricosa. 1. Page 516. Fig. 12. Amyda buiei. Xt

‘ Figs. 7 to 10. Amydaconcentrica. 1. Page 523. Fig. 13. Platypeltis serialis. 538.

; Fig.11. Amydalima. 1. Page 533. Fig. 14. Platypeltis heteroglypta. % I. Page 544.

baie
igs | | .
7 a AV |

Plate o9

Fossil Turtles

8.

Page 51

X 1.

x 0.3; Figs. 2 and 3,

Fig. 1,

Amyda equa.

Fossil Turtles
Plate roo

Fig. 1. Amydauintensis. X 0.27. Page 521.
Figs. 2 to 4. Amyda scutumantiquum. Fig.2, X 4; Figs.3and4, X 1.

eT

Plate ror

Fossil Turtles

‘epS o8eq ‘gto X
"1zS odeq ‘f'°0 X

‘eqydA[So19}0y stjedAjzelg
‘umnbrueuinjnos epAuy

J Fossil Turtles
Plate roz

Amydafrancisce. X 0.4. Page 523.

Fossil Turtles Plate 103

a a en

a

Amydafrancisce. 0.4. Page 524.

Plate 104

: Fossil Turtles

|

‘60S as3eg

‘66¢ o3eg

‘go X

‘tvo XX ‘euisshq sAWojsoxy ‘b'S1y
*‘stsuodiond sojeiopidsy “€ pue z ‘ssiy

‘yeS a8eq ‘f'0 X ‘esOIqeles epAWy ‘I °'314

Fossil Turtles
Plate 105

of

i
2
ag

<
qa

Fig.1. Amydamira. XX 4. Page 527.
, Figs. 2 and 3. Temnotrionyx manducans. I. Page 535.

¢ , *

a. Tan i et 7h ea nea) eer er aan

Plate 106

1 Turtles

Plate 107

31.

Page 5

> a

0.4; Figs. 2 and 3,

Fig. 1,

la.

Amyda egreg

Fossil Turtles

.

ee ee ,

Plate 3108

Amydacrassa. X 0.32. Page 532.

Fossil Turtles

Plate 109

Page 539.

Platypeltis serialis. Figs.1to3. X 3; Fig.4, X I.

— - 2.

Plate 110

Page 542.

xX #.

Platypeltis trionychoides.

|
;
;

Fossil Turtles
Plate 111

=

es

es

Platypeltis postera. X< 0.32. Page 545.

Plate r12

if Platypeltis extensa. X< 0.4. Page 546.

er

Fossil Turtles
Plate 113

Platypeltis leucopotamica. Fig.1, > 4; Figs.2and3, 1. Page 547.

e

~~

UTE

0738