556 



COLLEGE ZOOLOGY 



have poorly developed limbs or none at all. The glass " snakes," 

 Ophisaurus apus of Europe, and O. ventralis of America, have 



no limbs and move, 

 as do snakes, by 

 lateral undula- 

 tions. They can be 

 distinguished from 

 true snakes by the 

 presence of mov- 

 able eyelids and 

 an ear opening. 

 Fig. 458. 



A limbless lizard, Anguis fragiHs, the Their name is due 

 " slow-worm " or " blind-worm." (From Shipley and ^ ^ extrpme 



brittleness of the 



MacBride.) 



tail. Another species, called the " blind-worm " or " slow- 

 worm," Anguis fragilis (Fig. 458), inhabits Europe, western 

 Asia, and Algeria. It looks like a large, brightly colored 

 worm, but is not blind, since it has well-developed eyes. 



Family Helo- 

 dermatid^. ■ — 

 Beaded Lizards. 

 — The two species 

 included in this 

 family are the gila 

 monster, Hclo- 

 derma suspectum, 

 of Arizona and 

 New Mexico, and 

 the beaded lizard, 

 H. horridum, of 

 Mexico and Cen- 

 tral America. 

 The gila monster 



(Fig. 459) is the only poisonous lizard of the United States. 

 It has a stout body and is conspicuously colored with bright 



nBBninj 



Fig. 459. — The Gila monster, Heloderma suspectum. 

 (From Gadow.) 



