THE LIZARD 



366 



the speckled tortoise, black with round orange spots; and the wood 

 tortoise, with keeled shell, and plates marked with concentric strise. 



The order of snakes, or Ophi'dia,' is characterized by the 

 elongated Iwdy without appendages, and by the absence of 

 eyelids and sternum. like other reptiles, the snakes are chiefly 

 tropical, but inhabit also the temperate zones. They feed 

 on living animals. Hidden in the muscles of certain kinds of 



Fig. .344. — Eutenia, garter-snake, dorsal view. Photo, by E. R. D. 



snakes, rudimentary appendages are found, so we may conclude 

 that the ancestors of the snakes had legs. It is because snakes 

 are without legs that they travel so well through thickly 

 matted vegetation. 



The family Colubridse - includes the great majority of our 

 common non-venomous snakes, such as the garter-snake,^ 

 water snake, black snake, milk snake, and spreading adder. 

 Allied are the boas of South America and the pythons of India, 

 which attain a length of six metres or more. Not being poison- 



' opJds, serpent, ' coluhra, serpent. ^ Fig. 344. 



