310 ELEMENTARY ZOOLOGY. 



into pieces. It is generally true that the tails of lizards 

 are easily broken. They have the power of regenerating 

 or regrowing the lost part. 



FIG. 124. The swift lizard (Sceloporus undulatus). Adult. Photo by Shufeklt. 



The Ophidia, or snakes (Fig. 126), have lost their legs, 

 except the merest rudiments in a few forms, and possess 

 a very slender, much elongated body. By a peculiar ar- 

 rangement of the bones, the snakes have the power of 

 opening the mouth to an extent not found in other animals 



