WESTEBN SKINK 635 



afford admirable shelter and forage grounds for many of these lizards, as 

 does likewise the boulder talus along the north wall of Yosemite Valley. 

 In the latter place, however, the skinks live on the ground between the 

 rocks, in the debris consisting of accumulated oak leaves and pine needles ; 

 they do not go out on the surfaces of the rocks as do the swifts {Sceloporus 

 occidentalis) . Skinks are also to be found beneath fallen tree trunks or 

 in slight excavations (burrows of other animals probably) under rocks 

 lying on open ground. Logs or rocks in pastures or on grassy hillsides 

 quite often afford retreats for one or two of these lizards. In the 'mother 

 lode' district some individuals take shelter in the heaps of shale at old 

 prospect holes. 



Several skinks were obtained in mouse traps set on the ground under 

 bushes for the capture of small mammals. These particular individuals 

 either stumbled into the traps or else were attracted secondarily by ants 

 and other insects which had gathered to feed on the bait (rolled oats). 

 Still other individuals were obtained when we tore open dead and rotting 

 tree trunks lying on the ground. 



Western Skinks, particularly the blue-tailed youngsters, are able to 

 run with considerable speed when frightened and upon open ground. But 

 the normal movements, especially of adults, are rather slow and heavy. 

 On several occasions we had chances to watch individuals which were 

 undisturbed and engaged in foraging. The animals moved in a hesitating 

 manner, proceeding this way and that, advancing and then remaining 

 quiet for a second or two, usually going around rather than over small 

 rocks and other obstacles, even if of less than an inch in height. These 

 particular lizards kept their heads close to or even upon the ground, and 

 one in the course of its meanderings was seen to snap up small insects from 

 time to time. One red-headed skink was seen gliding over the surface 

 of a black-oak log in strong sunlight, one afternoon in June. As the animal 

 breathed a shimmering play of light was reflected from its smooth scales. 



Rubber Snake. Charina bottae (Blainville) 



Field characters. — Size small for a snake, length usually under 24 inches; body stout 

 and of about same diameter throughout; tail short, blunt ended, much like head in 

 shape; whole surface of body very smooth, skin loose fitting. Coloration plain greenish 

 brown above, uniform yellowish white beneath. A small spine (rudimentary leg) 

 projects, slightly, on each side of vent (at base of tail). Movements sluggish. 



Occurrence. — Recorded only from floor of Yosemite Valley. Lives on moist shadetl 

 ground. 



The Rubber Snake is a northern species belonging to the same family 

 as the boas and pythons of the tropical portions of the New and Old Worlds, 

 It never attains to anywhere near the size of those better known 'con- 

 strictors.' The individual mentioned below is the largest Rubber Snake 



