132 THE WASATCH AND BIMDGKK FAUX.E, 



carapace. The (.•hivicular (episternal) bone is preserved. It is character- 

 ized by the considerable and abrupt projection of that part inclosed by 

 the gular scutum, which resembles what is sometimes seen in Testudo. The 

 edge of this i)art is entire and acute. The posterior part of the projection 

 forms a step-like prominence behind, on the superior or inner face. The 

 bone is almost as wide as long, and the niesosternal causes a very slight 

 median truncation, but overlaps much on the inner side. The gular dermal 

 suture does not reach it. 



Measurements. 



L«?ngih of vprtebrul bono 00t> 



Wiatli of vcrtoliral bone 018 



Length of epistcmal 02 



Wid'.h of cpisteraal (transverse to axis of body) 017 



Width of a costal Oil 



Thickness proximally W^ 



In the second specimen, a strong groove is seen to bound the lip of the 

 front lobe of the plastron. In it the marginal is seen to be stout, a little 

 recurved, and sharp-edged. A vertebral differs from those of other species 

 in being longer than wide. In a third individual the gular lip is not so prom- 

 inent as in the type, and the mesosternal bone truncates the clavicular exten- 

 sively, giving it thus a more elongate form. The gular scuta expand to 

 its front margin. The marginal bone is stout and sharp-edged, and is not 

 so deeply impressed by the dermal suture as in P. jwli/ci/pha. 



Emys megaulax Cope. 



Annual Report U. S. Geol. Surv. Terrs , 1872, p.628. E. pachylomus Cope, loc. cit., 629. 



Plate XVII, figs. 2G-33. 



Represented by remains of five or six specimens. They pertained to 

 a species of about the size of the salt-marsh terrapin Malacockmmys palus- 

 tris. The marked ptculiarity consists in the broad and abruptly sunken 

 sutures which separate the dermal scuta of the carapace. This is visible 

 on vertebral, costal, and marginal bones, where the area? between the sutures 

 are abruptly separated. The sutures partially interrupt the dorsal carinn. 

 This is wide and low. The surface is otherwise smooth. The scutal 

 sutures are not so much impressed on the plastron, and those of the gular 

 scutes extend on the mesosternal bone. 



