276 



FOSSIL ITRTI.ES OF NORTH AMERICA. 



except that they, like the other hones of the carapace, appear to be somewhat thinner. The 

 vertebral scutes are perhaps relatively a little wider than in B. wyomingensis. There are 3 

 broad dorsal carinae a median and two lateral. The median may be traced farther forward 

 than in B. wyomingensis, as far forward as the front of the third neural. The lateral carinse 

 run just outside of the vertebral scutes. They are of moderate height posteriorly; on the 



Figs. 346 and 347. Baptemys tricarinata. Carapace and plastron of type. Xj. 



346. Portion of carapace, c.p. I, first costal plate; n. i, n.8, first and eighth neurals. 



347. Plastron and portion of carapace. 



anterior half of the carapace thev may be traced to the hist costal; but on the three anterior 

 costals thev form very low ridges. 



Fig. 34" represents the plastron. The total length is 285 mm. The anterior lobe is broad, 

 rounded, and slightly notcht in front. The length is 92 mm.; the width at the base, 148 mm. 

 The entoplastron is larger than in B. wyomingensis, being 65 mm. long and 75 mm. wide. The 



349- 



Plastron and humerus of type. 

 349. Right humerus. 



X*. 



FlGS. 348 AND 349. Baptem\s tricarinata. 

 34S. Anterior lobe of plastron. 



bridge is 93 mm. wide, relatively narrower than in the Bridger species. The hinder lobe is 

 105 mm. long and 1 1 1 mm. wide at the base. The sides converge backward to a point. 



The scutal areas are represented in fig. 347. No gulars are markt out; but there is a notch 

 in the border of the epiplastron, as if for the crossing of the gulo-humeral sulcus. There are 

 on each bridge 3 inframarginals like those of most specimens of B. wyomingensis. 



