156 REPTILES OF THE WORLD 



table fangs and attendant glands for the injection of 

 some virus to stupefy the prey, like the apparatus of 

 Heloderma. 



Among all members of the Anguidce, the body is 

 coated with bony plates underlying the scales, which are 

 arranged in overlapping, imbricate fashion — in rings. 

 The tongue is composed of two distinct parts; the pos- 

 terior portion is thick and fleshy; anteriorly the organ 

 is thin and nicked at the tip; the anterior portion is 

 retractile into the rear, fleshy part. Two genera are 

 characterized by a deep fold in the skin on each side 

 of the body. Throughout the family, the tail is very 

 brittle. In this family we find viviparous species. The 

 members are carnivorous and insectivorous. 



The Plated Lizards; genus Gerrhonotus: Nearly 

 two dozen lizards, looking very much alike, come under 

 this head. Several species inhabit the western portion 

 of the United States. Mexico and Central America, 

 however, are their headquarters. The back and tail are 

 covered with large, square shields or scales, giving one 

 the idea of shingles. On each side of the body is a 

 deep fold, the skin adjacent to which is covered with 

 granular scales. The abdomen is plated with square, 

 smooth shields. Many of the species have a very long 

 tail. With all, the limbs are well developed. 



Technical students find the lizards of this genus par- 

 ticularly difficult to identify. Much depends upon the 

 arrangement of the plates on the head, the number of 

 rows of scales on the body and the smooth or keeled 

 surface of these scales or plates. On some of the spe- 

 cies most of the plates are comparatively smooth; on 

 others they are marked with dull keels; several of the 

 species have a certain number of the plates on the back 

 keeled while those on the sides are smooth; one species 



