540 



COLLEGE ZOOLOGY 



3. REVIEW OF THE ORDERS AND FAMILIES OF LIVING REPTILES 



Order i. Testudinata. TURTLES and TORTOISES. The 

 TESTUDINATA are reptiles with a short, stout body provided with 

 a shell a structural feature that distinguishes them from other 

 animals as effectively as wings and feathers do the birds. They 

 are without teeth; the neck is very flexible; and the limbs are 

 fitted for creeping, running, or swimming. The position of the 

 pectoral and pelvic girdles within instead of outside of the ribs is 

 peculiar. They all deposit eggs in sand or earth, where they are 

 left to develop. Some turtles are carnivorous; others are 

 herbivorous. 



America is the richest of all countries in TESTUDINATA. Three 

 of the eleven families DERMATEMYDID^E, KINOSTERNID^E, 

 and CHELYDRID.E are now restricted to North and Central 

 America. Most of the land and fresh-water turtles hibernate 



in the earth during 

 the winter, but in 

 warmer countries 

 they sleep during 

 the hotter months 

 (aestivate) . 



Family CHELY- 

 DRID^E. SNAPPING- 

 TURTLES. - - Only 

 three species belong 

 to this family. 

 Chelydra serpen- 

 tina, the common 

 snapping-turtle, in- 

 habits fresh-water 

 ponds and streams of North America east of the Rocky Moun- 

 tains and southward to Ecuador. It is a voracious, carnivorous 

 animal feeding on fish, frogs, water-fowl, etc., and does not 

 hesitate to attack man with its formidable beak, often inflicting 



FIG. 444. The alligator turtle, Macrochelys 

 lacertina. (From Gadow.) 



