SNAKES, LIZARDS, TURTLES, AND CROCODILES 267 



along the grooved teeth into the wound. The bite of this ill- 

 looking reptile may be very serious. 



The most common lizards in this country are the swifts 

 and ground lizards that are so numerous in many gravelly 

 and bushy places. They may often be seen sunning themselves 

 on rocks, fences or other exposed places. They are all very 

 timid. An interesting member of this group is the glass snake, 

 or joint-snake. Having no external limbs it is commonly 

 considered to be a snake rather than a lizard. Its tail is so 

 brittle that part of it may break off at the slightest pull or blow. 

 In time a new tail is regenerated. Many other lizards 

 possess this power of easily breaking off a portion of the tail. 

 It will be seen that this may often be of considerable impor- 

 tance to the lizard, for if it is pursued by an enemy the part 

 most likely to be seized is the tail, and if this can be broken off 

 the lizard may escape and in time the lost part be replaced. 



In the desert regions of the Southwest are found several 

 species of the peculiar little lizard commonly known as the 

 horned toad, genus Phrynosoma. The body is shortened, 

 much flattened, and furnished with a number of spine-like 

 scales. These spines are particularly well-developed in a 

 row along the hind margin of the head. The color of these 

 animals resembles very closely the soil or rocks where they are 

 found. This protecting coloration doubtless helps to save 

 them from their enemies. In the tropics many of the lizards 

 attain a great size, and are of strange shapes and patterns. 

 Some of the tree-inhabiting forms are very beautifully colored. 

 The iguanas in South America often reach a length of five or 

 six feet, and are much used for food. 



The appendages are entirely absent in most of the snakes. 

 A few species, however, have a pair of spur-like projections 

 on the hinder part of the body, doubtless vestiges of the hind 

 legs. The lower side of the body in front of the anus is covered 

 with broad scales, called abdominal s'cutes, which extend 

 from one side of the body to the other. The ends of these 

 broad scales are attached to the ribs, and the free posterior 

 edges may be drawn forward slightly and pressed against the 

 surface on which the snake is lying so that when they are 



