18. CNEMIDQPHORUS 5£5 



in extent, and in some specimens the chest is mostly black. 

 The lower surfaces of the limbs are grayish, sometimes with 

 blackish markings. The tail is yellowish or grayish olive 

 brown above, darkest along the keels of its scales. The 

 scales on the lower surface of the tail usually are heavily 

 marked with black except distally, where they are brownish 

 or bronze. 



Length to anus 68 72 88 92 95 100 



Length of tail 165 182 207 232 233 233 



Snout to car Hyi 16 19 21 22 23 



Snout to interparietal 12 13J^ 15 16 16 17 



Width of head 9 10 12 13 13 15 



Fore limb 23 27 29 33 33 36 



Hind limb 45 50 52 61 62 65 



Base of fifth to end of 



fourth toe 22 24 22 27 26 29 



Distribution. — Cnemidophorus dickersonir is known from 

 Angel de la Guardia Island and from the neighboring Pond 

 Island and Isla Partida, in the Gulf of California, Mexico. 

 A young specimen from Smiths Island probably belongs to 

 this species but is not typical. 



Habits. — This lizard was abundant on Isla Partida and 

 rare on Angel de la Guardia. On the former it was numer- 

 ous in the small brushy canyons and among fallen cacti. 

 Sometimes six or seven were found about the fallen trunk of 

 a single tree. In a small open space about six feet square, 

 made in a rock slide while digging for petrel eggs, 1 2 speci- 

 mens of this lizard were counted picking up beetles and in- 

 sects which had been uncovered by the removal of the 

 stones. 



