66 UNIVERSITY OF COLORADO STUDIES 



Moderately large lizards found in southwestern United States and 

 northern Mexico. The food of these lizards consists of insects, small 

 toads and lizards and often small individuals of their own species. 

 They will also eat small flower heads. As regards food, they stand 

 between the strictly herbivorous Dipsosaurus and the insectivorous 

 Sceloporus. One species is known from Colorado. 



Crotaphytus collaris (Say) 

 Collared Lizard 

 Agama collaris Say, Long's Exped. Rocky Mts., Vol, II, p. 252, 1823. 



Two subspecies of this lizard are described. They may be dis- 

 tinguished by the following key. 



a. Interorbital plates in a single row C. c. collaris (Say). 



aa. Interorbital plates in at least two rows. . . C. c. baileyi (Stejneger). 



At present only the subspecies baileyi is known from Colorado. 

 However, as the true collaris is recorded from points near Colorado, 

 that variety should be looked for in southern Colorado. 



Crotaphytus collaris baileyi (Stejneger) (Figures 3 and 4) 



Crotaphytus baileyi Stejneger, iV^. Am. Fauna, No. 3, p. 103, 1890. 



Crotaphytus collaris baileyi Cockerell, Univ. Colo. Studies, Vol. VII, p. 131, 

 1910 (Rifle Gap, Garfield Co., Colo.); Cary, N. Am. Fauna, No. 33, p. 25, 191 1 

 (McElmo, Coventry and Sindbad Valley, Colo.). 



Head depressed, very broad in the region just back of the eyes, 

 pointed anteriorly and narrowed posteriorly, length a little less than 

 that of the hind foot; scales small, ventral scales larger than the 

 dorsal scales; length from the tip of the snout to the vent about 2 

 in the length of the tail; maximum total length about fifteen inches. 



General color grayish yellow, yellowish brown, grayish green or 

 green; a double collar of two black bands, very heavy at the sides 

 and interrupted dorsally, separated by a band of white or yellow and 

 bordered with the same color; ventral parts yellowish or greenish; 

 throat yellow or orange ; under parts of the jaw bluish; dorsally with 

 numerous small light spots; sides of the abdomen and the tops of 

 the hind limbs with small dark red spots; inside of the back of the 



