SNAKES, TURTLES, LIZARDS, CROCODILES 



257 



weight (Fig. 177). The eyes are large and, to a certain 

 extent, each is independent of the other. The tongue is club- 

 sliaped and can be darted out from the mouth to the extent 

 of six or seven inches for tlie purpose of catching insects 

 on its sticky extremity. There are several layers of different 

 colored pigments in the skin, any one of which may be 



Fig. 177. —Old World chameleon. 



made to predominate by contracting and masking the 

 others. In this way the animal is able to change its 

 color. 



The Phrynosoma. — This reptile is found in the western 

 part of the United States and is known as the "horned 

 toad." The body, barring the tail, somewhat resembles 

 that of a toad, but the spinelike scales that occur on the 

 head, neck, and tail of the animal indicate its relation to the 

 reptiles. The feet and legs are used for running and not 

 for hopping. The horned toads show a remarkable adap- 

 tation in coloring to soil on which they live. They can be 



iierrick's zool. — 17 



