C R O T A P H Y T U S .—Holhrook. 



Genus Crotaphytus. — Characters. Head large, sub-triangular, rounded at 

 the snout and greatly developed at the temporal region; covered above with 

 small polygonal plates; largest on the vertex maxillary, palatine and sphenoidal 

 teeth; the posterior maxillary compressed laterally, and tricuspid at their cutting 

 margm. Body covered with small, polygonal, smooth plates; tail very long, 

 covered with oblong-quadrate plates, verticillated, larger than those of the body, 

 smooth on its anterior half and carinated on its posterior; femoral pores well 

 developed. 



CROTAPHYTUS COLLARIS.— Say. 



Plate X. 



Characters. Head short, thick, sub-triangular, rounded at the snout, arched 

 at the forehead, broad at the temples; covered above with small polygonal plates, 

 largest on the vertex and occiput; eyelids serrated at their margins. Body 

 elongated, depressed, dusky, with a deep tinge of green or purple, spotted with 

 rays of white colour; two transverse black bars between the shoulders, with an 

 intermediate one of white; tail very long, covered with verticillated plates, 

 smooth on the anterior, carinated on the posterior half; femoral pores well 

 developed. 



SrNONTMES. Agama collaris, Say, Long's Exped. to Rock. Mount., vol. ii. p. 252. 

 Agama collaris, Harlan, Med. and Phys. Res., p. 142. 



