EXPLANATION OF PLATE XIV. 



Chisternost undattjm, originally referred to Baena nndata. Figures oue-half the natural size. Speci- 

 men discovered in the vicinity of Fort Bridger by Dr. Carter, and presented by him to the 



• Academy of Natural Sciences. 



Fig. 1. View of the carapace ; the sutures scarcely visible. 



Fig. 2. View of the greater portion of the plastron, with the left border of the carapace. 

 The crucial suture of the plastron is visible, from which the genus received its name. 



