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. 
