36 REPTILES OF THE WORLD 



ical Africa is iiiliabited by three of the most grotesque 

 members among tortoises ; their shells suggest an attempt 

 of Nature to construct something unique with a some- 

 what overdone result. The rear portion of the upper 

 shell is hinged and can be drawn down tightly against 

 the plastron, which, in front, projects forward like a 

 battering ram. About the margin the upper shell flares 

 upward. Altogether the effect is irregular. A roman- 

 tic observer might be led to believe that these tortoises 

 are ashamed of their make-up, as they snap the limbs 

 and head inward at the least intimation of a shadow 

 or vibration, when the hinged part of the upper shell is 

 pulled downward; the forearms are so bony and fit so 

 tightly together, the protection they afford is complete, 

 unless the enemy be a long-clawed cat or an iron- jawed 

 hytena. 



The species of the genus Pyxis, P. arachnoides, inhab- 

 iting Madagascar, has the front lobe of the plastron 

 hinged. 



Genus Testudo: All portions of the shell are rigid. 

 A few representatives are the only New World tortoises. 



The North American Tortoises are three in num- 

 ber. They may be concisely defined, thus: — 



I. Carapace considerably longer than wide. 



Several much-enlarged, bony plates on inner surface of forearm. 



GoPHEE Tortoise, T. polyphemus. 

 Habitat: South Carolina and Florida to western Texas. 

 No enlarged bony plates on forearm. 



Agassiz's Tortoise, T. agassizii. 

 Habitat: Deserts of the southwest United States. 



II. Carapace nearly as wide as long. 



Behlandieh's Tortoise, T. berlandieri. 

 Habitat: So. Texas; Mexico. 



Adult examples of all these species are of a dull, 

 uniform brown above. Young and half -grown Individ- 



