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 
