16 REPTILES OF THE WORLD 



practically opaque with thick deposits of silt, it would 

 seem that the animal would choke and require no eyes 

 for its strictly aquatic existence. Arizona and New 

 Mexico form the habitat. Southward, in Old Mexico, 

 is found a closely related species known technically as 

 Cinosternum integrum, with a flat, crushed-in plastron 

 and lobes that close as perfectly as do those of the true 

 box turtles — Cistudo. 



So thoroughly at home in the water are the species of 

 Cinosternum they may be kept in deep tanks, without 

 any means of resting above or near the surface, yet 

 under such conditions will flourish for years. Their 

 swimming movements are graceful and deliberate. 

 Much of the time is spent in crawling over the bottom. 

 In coming to the surface for air there is no apparent 

 hurry, but a slow, treading motion of the limbs, with 

 webs widely extended. Captive Mud Turtles will eat 

 chopped fish, earthworms and raw beef. In a wild state 

 they are veritable scavengers. 



A single species represents the family Platysternida?. 

 It inhabits southern China, Burma and Siam. The pro- 

 portionately very large head with hooked mandibles and 

 the long tail, cause this animal to resemble the New 

 World snapping turtles — Chelydrida?; it really stands 

 intermediate between that family and the Testudinidai. 

 The carapace is much flattened ; the plastron is broad and 

 possesses a square front lobe. In a peculiar structure of 

 the skull — "the temporal region completely roofed over" 

 — the species is, from a technical point of view, abso- 

 lutely unique among chelonians. A large example has 

 a carapace five inches long; with head and tail out- 

 stretched the turtle will measure fourteen inches. 



Family Testudinidce; Turtles, "Terrapins" and 

 Tortoises : This large family is represented in all tern- 



