reptilp:s of the pacific coast. 73 



reveal its presence at Tlie Needles in San Bernardino 

 County. 



Habits. — At Yuma this lizard is verv abundant, but is 

 rarely seen on the ground, preferring to climb over the 

 rough bark of the willows or to hide between the planks 

 of the railroad bridges. It feeds chiefly upon small 

 insects. 



Genus 12. SCELOPORUS. 



Sceloporuii, Wiegm., Isis, 1828, p. 369. '^ Tropidolepk, Cuv., R. A. 

 (2), II, p. 38." 



The head and body are slightly depressed and shorter 

 than the tail. The head-plates are of moderate size, 

 excepting the interparietal, which is very large. The 

 dorsal scales are large, nearly equal sized, mucronate, 

 and strongly imbricate. The ear-opening is large, with 

 a well developed anterior denticulation. The labials 

 are juxtaposed. There is no complete transverse gular 

 fold, but a pouch is present on each side of the neck. 

 Femoral pores are numerous. The superciliaries are 

 imbricate. 



SYNOPSIS OF SPECIES. 



a. — Parietal and Irontoparietal plates separated from enlarged supraoculars 



by ii series of small scales or granules; scales on back of tbigh smaller 



than tbose in front of auiis. 



b. — Dorsal scales very small, forty-five to sixty-six on the middle of the 



back between interparietal plate and base of tail; scales on back of 



thigh smooth S. graciosus. — p. 74. 



b^. — Dorsal scales larger, thirty-five to forty-six on a line between inter- 

 parietal and base of tail; scales on back of thigh keeled.* 

 c— Males with a blue patch on each side of the throatt; usually 

 smaller S. occidentalis. — p. 77. 



* Sometimes smooth in young. 



t I have examined many hundreds of specimens of 5. occidentalis and 5. biterialus and 

 have not found a male of the latter with two blue throat-patches. Highly colored males 

 of iS. occidentalis are sometimes found in which the two blu<' jiatches have extended to, 

 and even merged on, the median line, but by securing very young, or less brilliantly 

 colored, males there should be no difficulty in determining which species occurs in a 

 given locality, for such males never have a single median blue patch if they belong with 

 S. occidentalis, and never have two lateral patches if referable to S. biseriatus. Females of 

 the latter species have either one or two bine patches, while those of the more northern 

 form nsnuUy have two or n(ine. 



