632 ANIMAL LIFE IN THE TOSEMITE 



When traveling, even when undisturbed, an Alligator Lizard progresses 

 slowly and rather clumsily, wriggling its body from side to side. Some 

 of the relatives of this lizard in other parts of the world have entirely lost 

 their legs, and their locomotion is accomplished in much the same manner 

 as in snakes. Perhaps this relative handicap on the part of the Alligator 

 Lizard when making its escape or when cornered is compensated for by 

 the formidable appearance and Sdcious' temper of the animal. The tongue 

 is rapidly protruded, in the fashion of some snakes, and this, with the 

 further feature of yellow iris, adds to the menacing 'front' put up by the 

 animal. 



The Alligator Lizards (both species) are insect feeders. 



California Whip-tailed Lizard. Cnemidophorus tigris mundus Camp 



Field characters. — Body and especially tail long and slender; legs st,oat, the hinder 

 pair much the larger ; toes long ; a well marked fold of skin across throat ; back and 

 sides of body covered with minute rounded bead-like scales; under surface of body with 

 flat rhomboid scales arranged in eight lengthwise rows ; tail with ridged or keeled 

 scales. (See pi. 57c.) Coloration varying with age, striped in young, becoming spotted 

 in adults. Ground color of body blackish, with lengthwise stripes (young) or with 

 scattered small spots of buff, yellow or white (adults) ; sides of head and legs blotched 

 with dusky; under surface white, with scale edgings of black; tail dark brown above, 

 yellowish beneath. Head and body measuring to 4 inches; tail to 10 inches. 



Occurrence. — Eesident in small to moderate numbers on west side of Yosemite region, 

 chiefly in Upper Sonoran Zone. Eecorded from Pleasant Valley eastward to Smith 

 Creek, 6 miles east of Coulterville, and to foot of Big Oak Flat road in western part of 

 Yosemite Valley. To be seen on surface of ground in open gravelly or sandy places. 



The swiftest of all the lizards in the Yosemite region is the California 

 Whip-tailed Lizard which occurs at certain locations in the western part 

 of the section. This reptile is ordinarily thought of as an inhabitant of 

 desert regions, and in truth it is ; but it also occurs, or did occur formerly, 

 on much of the floor of the San Joaquin Valley, and it penetrates into 

 the foothills wherever there are conditions suitable for its existence. Its 

 distribution in the Yosemite section is not continuous. AVe found it at 

 Pleasant Valley, about Coulterville, at Smith Creek, in the neighborhood 

 of Kinsley, and at two locations in the lower end of Yosemite Valley, 

 namely, at the foot of the Coulterville grade and at the foot of the Big 

 Oak Flat grade. 



The whip-tailed lizard is specialized in somewhat the same manner as 

 the kangaroo rat, and to achieve the same result. Its whole organization 

 is modified for the attainment of speed in running on the surface of the 

 ground. The body is slender and the tail is fully twice the length of head 

 and body together, and finely and evenly tapered to the end. (See pi. 57c.) 

 The legs are stout, especially the hinder pair, and the toes are long, par- 



