6. CROTAPHYTUS 111 



Dr. Ruthven who observed them in New Mexico, states: 

 "Here they may be seen on sunny days running about on 

 the ground between the bushes or occasionally climbing 

 among their branches. When approached carefully they 

 will occasionally lie very quietly until one is within a couple 

 of yards, their colors harmonizing so perfectly with the light 

 soil that, unless one is aware of their exact whereabouts, it 

 is difficult to detect them. They can seldom be approached 

 in this way, however, as they are very shy, and usually the 

 first intimation that one has of their proximity is a fleeting 

 glimpse of a light colored body dashing off across the desert. 

 When frightened they run with great swiftness from bush 

 to bush, often for several rods, which is in contrast with 

 the habits of the smaller lizards in the same habitat, which 

 usually stop beneath the first clump of vegetation. They 

 are very pugnacious, fighting furiously when wounded, but 

 their food does not indicate as fierce a nature as that of 

 C. wislizenii. As far as observed their diet consists ex- 

 clusively of insects grasshoppers, beetles and locusts being 

 found in the stomachs of those examined. A large grass- 

 hopper forms the bulk of the contents of these stomachs." 



Walter P. Taylor, in western Nevada, "looked in vain 

 for this lizard on the open desert and on certain of the lower 

 slopes of the mountains. All but one were secured on top 

 of a steep-sided, rocky ridge (altitude 5000 feet) near Big 

 Creek Ranch. The exception was collected in Big Creek 

 Canyon just below the Dugout Camp (4800 feet) and at the 

 base of the steep-sided ridge just mentioned. 



"One was apparently resting in a groove on one of the 

 stones. We saw none on very large boulders. Crotaphytus 

 c. baileyi does not seem to be as adept at clinging to rocks 

 in any position as is Scelo-porus biseriatus. The movements 

 of Crotafkyfus c. baileyi resemble those of C. wislizenii. 



