262 



SXAKES, TUirrLF.S, LI/AI!1)S, CKoCoDILES 



head is i-etracted the front feet and legs are brought around 

 ill front and used coiiiplelcly to dose the opening in the 

 front of tl^e sliell. The liiiid feet are ehil)-sliaped and each 



Fig. 181 . — Goplier turtle. 



ends in four toe nails. They li^•e in burrows dug in the soil 

 to the depth of four or five feet. 



Chief characteristics of the turtles. — The bodies are short 

 and stout and incased in a, more or less bon}' hiox, called 

 the shell. The shell consists of two portions, an vipper 

 portion, the carapace (Fig. 182), and a lower portion, the 

 flastnm. These are immovalih' united by the edges, along 

 the sides, but remain open in front for the protrusion of the 

 head and fore legs, and beliind, to alloM' action of the hind 

 legs and afford room for the tail. The turtles have no teeth, 

 but the hoi-ny jaws have sharp, chisel-like edges that form 

 a most efficient cutting ap]iaratus. In most cases the head, 

 tail, and legs may be retracted within the shell. In most 

 turtles the sliell is very complelely ossified and covered 

 with scales. In the soft-shelled liirtles, the shell is not so 

 bony but remains soft, while in the leatlier turtle, the soft 



