GILMORE: the fossil turtles of the UINTA FORMATION 



137 



axillary notches the borders thin rapidly toward the center. The costoperipheral 

 sutures pass along the median sides of the shell on an average of about 17 mm. 

 mesiad of the marginal sulcus. Beyond the bridges the sutures and sulci in some 



Fig. 14. Echmatemys ohscura. Carapace of type, C. M. No. 3252. One-fourth natural size. n. 1, 

 71. 6, neurals one and six; n.p., nuchal plate; I'.s. 4, fourth vertebral scute; c. 6, sixth costal. 



places approach one another as close as 4 mm., and in other places are distant as 

 much as 30 mm. 



The nuchal scute is narrow, measuring 8 mm. on the free border. It is 15 mm. 

 long antero-posteriorly. 



The vertebral scutes are wider than long, the second being especially wide. 

 The sides of those back of the first are bracket-shaped. Their dimensions are 

 given in the accompanying table. 



Dimensions or Vertebrals. 



The costo-marginal sulci run below the costo-peripheral sutures. The sulci 

 on both carapace and plastron are narrow and moderately impressed. 



The plastron in life had a length of about 372 mm. The posterior end is 



