54 REPTILES OF THE WORLD 



shields. Little is known of this queer turtle, which 

 seems to be entirely aquatic. Its shell is about eighteen 

 inches long. The species is recorded from the Fly 

 River, in New Guinea. 



Third and last of the superf amilies of the Thecophora 

 is the Trionychoidea — the Soft- Shelled Turtles. 

 These interesting fresh-water chelonians are unmistak- 

 able. Exceedingly flat, with an almost round or bluntly 

 oval shell, the animal looks as if coated with leather; 

 there are no horny shields, either above or beneath. 

 From the Soft- Shelled Turtles, the bony make-up of the 

 average turtle's shell is utterly lacking — the shell is soft 

 and pliable, except on the central portion of the back, 

 where the skeleton lies close to the surface; the head is 

 long, narrow and terminates in a projecting, tubular 

 snout. In keeping with decidedly aquatic habits, the 

 feet are broadly webbed. 



Eleventh and last of the families of Chelonia, is the 

 Trionycliidce, embracing all of the soft-shelled turtles. 

 From a technical point of view it is important to explain 

 that only the three inner toes are provided with claws, 

 and the neck, which is completely retractile, is tucked 

 back in a vertical plane, as with the Cryptodira. Six 

 genera are recognized, which represent a total of 

 about twenty-four species. 



Trionyx is represented by fifteen species, four of which 

 are the only New World soft-shelled turtles; the latter 

 are found only in North America. The remaining 

 genera are small ; their members occur in Asia, the larger 

 islands of the Malay Archipelago and in Africa. With- 

 out exception the species of all the genera frequent rivers 

 with a soft, muddy bottom. 



As the soft, flappy shell causes these chelonians to 

 appear so different from other turtles, they might be 



