394 



ZOOLOGY 



The Sauria include, beside the types commonly known as lizards, the horned- 

 toads, and the glass snake — a legless lizard. They subsist largely on insects and 

 the eggs of other animals. Only one species is known to be poisonous — the "Gila 

 monster" of New Mexico and 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. They 



Fig. iqS. 



Fig. 198. Swift Lizard [Sceloportis undulatus). Adult. 



Shufeldt. 



Photographed from life by Dr. R. W. 



run, burrow, and climb. One species (Fig. 199) has a membrane extending from 

 the sides, supported by ribs, that serves as a parachute. 



Suborder Predenlia, includes the chameleons. 



Suborder Serpentes. — 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 account of the elongate, movable 

 quadrate bone. Teeth arc numerous and fastened (not in sockets) to the hones 



