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- 



~??..c- -V*KX_ --.-**>- -- able e y elids and 



- Srt^jL- an ear opening. 



FIG. 458. A limbless lizard, Anguis fragilis, the Their name is due 

 " slow-worm " or " blind-worm." (From Shipley and f f i, 

 MacBride.) 



brittleness of the 



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.E. - 

 BEADED LIZARDS. 



-The two species 

 included in this 

 family are the gila 

 monster, Helo- _ 

 derma suspedum, 

 of Arizona and 

 New Mexico, and 

 the beaded lizard, 

 H. horrid um, of 



Mexico and Cen- 

 tral America. 



I-IG. 459. The Gila monster, Heloderma suspecium. 



(From Gadow.) 



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 



