WlLLISTON.] 



Turtles. 



369 



From the superior eniargination, a deep groove descends to be- 

 low the middle, probably for ligamentous insertion. The neu- 

 ral canal is subtrilateral. 



Fig. 6. Caudal vertebras of Cynocercus inclsus Cope. 



" The neural arch is, as usual in this group, deeply emargin- 

 ate in front, and much prolonged behind. The zygapophyses 

 project beyond the ball, and the arch is contracted in front 

 of them. Its upper surface has neither process nor keel, but is 

 rugose for ligamentous and muscular insertion. The diapophy- 

 ses have a wide base, and are sub-cylindric. 



"Another vertebra differs in being rather more slender, and 

 in having an obtuse keel of the neural arch. The pit of the 

 ball is wanting and the inferior emargination. The chevron 

 articulations are larger ; and the groove of the cup occupies its 

 middle, instead of its upper half." 



The locality is not given, but is probably Niobrara. 



