﻿'SO 3. IGUANIDJE 



or less clouded with gray. The lower surface of the tail 

 is white with about eight (six to 10) cross-bars of intense 

 black. The belly is whitish. Males have a large blue patch, 

 marked with two oblique wedge-shaped black blotches, on 

 each side, which rarely are united ventrally. Some males 

 have a reddish or orange gular and postaxillary suffusion. 

 Females lack the lateral blue patch and have the lateroven- 

 tral dark blotches gray or obsolete. 



Length to anus 60 65 65 66 66 67 



Length of taiL. 81 80 90 78 85 97 



Snout to back of inter- 

 parietal 11 \2)/ 2 U J / 2 12 12 12 



Snout to ear 12^ W/ 2 13 13 14 13 



Width of head... _ 11 11 10 11 11 12 



Fore limb 34 34 35 36 33 37 



Hind limb 60 60 60 61 5 8 65 



Base of fifth to end of 



fourth toe ... 24 24 24 24 23 26 



Distribution. — Angel de la Guardia Island, Gulf of 

 California, Mexico. 



25. Callisaurus inusitatus Dickerson 

 Sonoran Gridiron-tailed Lizard 



? Callisaurus centralis Van Denburch, Proc. Acad. Nat. Sci. Phila., 



1897, p. 461. 

 Callisaurus inusitatus Dickerson, Bull. Amer. Mus. Nat. Hist., Vol. XLI, 



1919, p. 465 (type locality, Tiburon Island, Gulf of California, 



Mexico). 



Description. — Head rather short and low, with well 

 developed canthus rostralis. Nostrils large, opening on 

 upper surface of snout. Supraocular regions covered with 

 small or moderate sized plates and separated from each 

 other by one or two rows of plates. Upper head plates 

 (except interparietal) small and irregular, largest on frontal 

 and prefrontal regions, everywhere smooth and rather flat. 



