TRETEN 
Puare 20. 
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. 
