EMYDID^E. 



329 



the other, is 56 mm. wide. A notch in the border produces a blunt tooth on each side. 

 Beyond the notch the general curvature of the lobe is continued on to the midline. It remains 

 to be seen whether this character will persist in additional specimens. Seen from above (fig. 

 430), the lip is 66 mm. wide from one gular suture to the other, and continues backward 32 

 mm. The entoplastron is diamond-shaped, 55 mm. long, 65 mm. wide and 1 1 mm. thick. It 

 supports the hinder portion of the gular scutes, but no part of the pectoral scutes. 



The hyoplastra occupy /2 mm. of the midline; the hypoplastra, 93 mm.; the xiphiplastra, 

 78 mm. The hinder lobe of the plastron is 107 mm. long; its width at the base is 145 mm. 

 The upper surface of the hypoplastron (fig. 431) behind the inguinal buttress was covered 

 with horny epidermis as far inward as the buttress extends, 31 mm. In all accessible specimens 

 of E. wyomingensis this surface is much narrower. The inner edge of the inguinal buttress 

 arises from the floor of the plastron at a line not half-way from the free border of the lobe to 

 the midline, resembling in this respect E. wyomingensis. 



The gular scutes extend along the midline 42 mm.; the humerals, 42 mm.; the pectorals, 

 42 mm.; the femorals, 56 mm.; the anals, 55 mm. 



The species differs from all others of the genus, so far as known, in having the humero- 

 pectoral sulcus cross behind the entoplastron. 



435- 



FIGS. 432-435. Echmatemys ocyrrhoe. Portions of type. 



432. Carapace. Xi- 433. Plastron. X}. 



434. Upper surface of anterior lobe of plastron. X^. 



435. Upper surface of inguinal region of plastron, showing base of 



inguinal buttress and free border of hinder lobe. X$. 



Echmatemys ocyrrhoe sp. nov. 

 Figs. 431-435. 



Two specimens in the American Museum of Natural History represent this species, No. 

 5933 and No. 5954. Of these, No. 5933 is taken as the type. It was collected in 1903 by Mr. 

 Walter Granger in the Bridger Eocene beds at Church Buttes, Wyoming. No. 5954 was 

 collected by the writer in 1903, in the western portion of Grizzly Buttes, Wyoming. Both 

 specimens therefore come from the lower part of the horizon B of the Bridger beds, the speci- 

 men from Church Buttes belonging probably to a slightly lower level. 



No. 5933 presents the shell nearly complete. The second suprapygal, most of the pygal, 

 the eleventh peripheral of the right side and the distal ends of the eighth pair of costals are 

 wanting. No. 5954 furnishes the plastron backward as far as the hypoxiphiplastral suture 

 and various portions of the carapace, including the hindermost peripherals, but not the pygal. 



