TAB. XI. 

 Skull of the Chelone crassicostata, two thirds of the nat. size. 



Fig. 



1. Upper view, showing chiefly a cast of the under surface of the bones. 



12. The situation of the postfrontals. 14. The prefrontals. 15. The nasals. 



2. Side view. 



3. Under view of the symphysis menti. 



