6 4 



FOSSIL TURTLES OF NORTH AMERICA. 



The total length of the carapace (plate 9) was originally 368 mm.; the total breadth, 

 280 mm.; the height from the bottom of the plastron, about 145 mm. The greatest breadth 

 of the carapace was somewhat behind the inguinal notches. From here the border rounds 

 rapidly to the median excavation behind. The anterior end is rather pointed. In front, the 

 margin of the carapace is unbroken by serrations or sinuses, except that the nuchal is slightly 

 excavated. The hinder portion, from the inguinal notches backward, is scallopt as in the 

 other species of the genus. It is also thin and rather acute. Even at the bridges the border was 

 narrowly rounded. 



Fig. 40. Ba'ena hatchert. Type. 

 Xj. Carapace. 



Fig. 41. Ba'ena hatcheri. Type. 

 X. Plastron. 



The sutures between the bones are fine and their course is often indicated by only the 

 finely striated border of the adjoining bone. 



The nuchal bone is nearly quadrate in form. It is 43 mm. long fore and aft, with a width 

 of 59 mm. in front and a maximum width of 72 mm. The neurals in general are hexagonal, 

 with the broader end forward. The table annext presents the dimensions ot the neurals. 



The single suprapygal had a length of 50 mm. and a width of 56 mm. No true pygal is 

 interposed between the peripherals of the last pair. 



The costal plates vary considerably in the fore-and-aft extent. Measured at their proximal 

 ends they have the following widths: First, 48 mm.; second, 40 

 mm.; third, 47 mm.; fourth, 33 mm.; fifth, 47 mm.; sixth, 32 mm.; 

 seventh, 32 mm.; eighth, 31 mm. The fifth costal presents the 

 peculiarity of being very narrow at the distal end only 9 mm. 

 The peripherals are high, the first two about 38 mm.; the 

 third, 33 mm.; the next three, about 52 mm.; the seventh, eighth, 

 ninth, about 68 mm.; the tenth, eleventh, and twelfth, about 

 48 mm. The sutures between the peripherals behind the eighth 

 are not visible, but they were probably not far removed from the 

 lines representing them. 



The epidermal scutes are all defined by sulci which are 



