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 
