389 



FIG. 195. Swift Lizard (Sceloporus undulatus). Adult. Photographed from life by 



Dr. R. W. Shufeldt. 



southward. The glass snake possesses in a high degree a power more 

 or less common among lizards of breaking loose from the tail when 

 struck or held by that organ. In some species, at least, a new tail may be 

 regenerated. Most lizards are terrestrial, though a few are aquatic. 



Order III. Ophidia (Snakes). Reptiles with elongated bodies covered 

 by fold-like epidermal scales which may be shed as a single " cast." Limbs 

 are wholly wanting. The mouth is capable of great extension on ac- 

 count of the great movability of the quadrate and other bones. Teeth 

 are numerous and fused (not in sockets) to the bones bearing them. 

 Sternum wanting. There are no movable eyelids. The tongue is pro- 

 trusible, and is doubtless much used as an organ of touch. 



Snakes are, like lizards, partial to warm climates, but are also found in 

 temperate latitudes. Most are terrestrial, but some take to water readily; 



