TESTUDINATA. 139 



Emys septaria Cope. 



Annual Report U. S. Geol. Surv. Terrs., 1872 (1873), p. 625. 

 Plate XVIII, figs. 9-13. 



Established on a nearly complete specimen of the size of Ptychemys 

 rugosa. The carapace is rather thin and the sutures not obliterated. The 

 vertebrae are sessile on the vertebral bones. The form is quite convex. 

 The plastron is flat and rather stout. The mesosternum is rhombic, the 

 longer angle anterior on the outer side, but posterior on the inner side. Its 

 anterior angle is embraced by the gular scuta. The anterior lobe of the 

 plastron is contracted near the axillae, and flared with a thin edge in front 

 of it, then contracted to the rather narrow lip of the middle front. The 

 posterior lobe is somewhat flared and has a wide beveled margin, and is 

 deeply notched behind, the notch being close, and the lobes projecting. 



The surface is delicately sculptured with obsolete ridged lines across 

 the axis of the costal bones. The vertebral region is somewhat swollen 

 between the cross-sutures, which present an obtuse angle in the same direc- 

 tion, both before and behind. The scuta are longer than wide, and have 

 bracket-shaped outlines. The surface has the obsolete ridges, which diverge 

 in every direction from the inlooking angle of one end, but are mostly 

 longitudinal. 



In old specimens this delicate sculpture might become obsolete. 



Measurements. 



M. 



Length (Jf plastron 325 



Width of plastron at groin 150 



Width of lip 054 



Length of lip OL'O 



Width of clavicular bone behind 041 



Width of mesosternal, externally 058 



Length of mesosternal, externally 045 



Thickness of hyosternal behind 015 



Length of vertebral scutum 072 



Width of vertebral scutum 068 



Width of a costal bone 029 



Thickness of a costal bone 006 



Found in the bad lands of the Washakie basin, on South Bitter Creek, 

 by the writer. 



