4'4 



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 the 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 is 148 mm. wide at its base. The hinder end of it is missing. 



By its prominent epiplastral lip this species suggests T '. thomsom of the Ohgocene 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 T. peragrans would be over 100 mm. wide if the animal 

 had attained the size of the type of T. thomsom; 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. 539-547. 



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, 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 vertebrae, and a few of the caudal vertebrae. 

 The catalog number of this individual is 1327. 



The plastron (fig. 539) has a length of 381 mm. The 

 length of the anterior lobe is 1 10 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 lip, 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 T. niobrarensis, as shown in 

 Leidy's type. The lip of another specimen, No. 1326, has the 

 lip 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. 



The entoplastron is rhombic, 68 mm. long, 74 mm. wide. 



The bridge of No. 1327 is 175 mm. wide. 



The hinder lobe of the plastron has a length of 86 mm., 



FIG. 539. Testudo vaga. Plastron 

 XJ. No. 1 327 A.M. N. H. 



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 outward. The inner face, at the notch, is concave. 



The gular scutes have an antero-postenor 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 57 mm. The sulcus limiting them behind is somewhat 



