GILMORE: the fossil turtles of the UINTA FORMATION 



145 



in the type of H. odonarius, but it has the same angular turn backward and out- 

 ward as in the type of the genus and species. The length of the entoplastron on the 



Fig. 18. Hadrianns corsoni (Leidy). Plastron of C. M. No. 3403. One-eighth natural size. 



midline is 155 mm.; its width 184 mm. It is overlapped slightly by the gular 

 scutes, but is not crossed by the humero-pectoral sulcus. 



The bridge is 290 mm. wide. 



The length of the posterior lobe is 234 mm.; its width at the inguinal notches 

 386 mm. The free edges of the lobe are subacute, except in front of the notches, 

 where it is rounded. The width of the posterior notch is about 135 mm. ; its depth 

 about 35 mm. There is no perceptible ridge leading back from the inguinal but- 

 tresses until a point midway between the buttress and the posterior end of the lobe 

 is reached, where the surface is concave mesiad, thus causing the ridge to stand 

 out quite prominently. On the outside of this ridge the surface is bevelled off 

 steeply near the buttress, but less and less so posteriorly, until on the posterior 

 outer angle of the xiphiplastral projections the slope is very gentle. The surfaces 

 of these projections are rugosely roughened as in the type of H. odonarius (No. 

 2186, U. S. National Museum), which they resemble in shape and size. 



The hyoplastron on the midline has a width of 195 mm. The arrangement of 



