TURTLES AND TORTOISES 51 



forests, that are filled by the rivers as they "back up" 

 durmg the great freshets.^ 



The species of Podocnemis are of a dull brown or 

 olive, with a very broad, flattened shell. Among all the 

 head is rather flattened, the eyes are set close together, 

 besides being directed slightly upwards. There is no 

 hinge on the plastron. 



Another family of the Pleurodira is composed of 

 truly remarkable chelonians; they are popularly called 

 Side-Neck or Snake-Necked Turtles, and make up 

 the family Clielydidce. The combined head and neck 

 of some of the present turtles more than equal the total 

 length of the shell. This serpentine neck is altogether 

 too long to be entirely tucked back into the shell, so 

 part of it is folded sidewaj^s, along the inner margin 

 of the shell, when the animal is frightened; thus the 

 origin of the popular title — "Side-Neck" Turtles. 

 About thirty species, divided into eight genera, belong 

 to this family. Five genera are restricted to South 

 America; the others are represented in Australia and 

 New Guinea. 



The BlatamatUj Chelys fivibriataj a South American 

 turtle, is not alone remarkable in having a long, later- 

 ally folding neck. It is one of Nature's nondescripts, 

 standing in a genus by itself. Each shield of its flat- 

 tened shell rises in pointed fashion, giving the back 

 an abnormally rough aspect — but most remarkable is the 

 structure of the head and neck. The former terminates 

 in a long, tubular snout, though at its base it is broad, 

 flattened and hesxj, with projecting, bony ridges; the 

 eyes are small and placed so far forward the eff'ect is 

 quite ludicrous. Intensifjdng the altogether eccentric 



1 For a detailed and entertaining account about these turtles, see Bates— 

 "The Naturalist On The River Amazon," 



