194 BULLETIN 15 4, UNITED STATES NATIONAL MUSEUM 



sAviftly," and Giinuell and Storer (11)24, p. Oo'i) have written tliat 

 '' In places where there are no open rodent burrows, and where the 

 soil is sufficiently loose, whiptails dig their own burrows." 



The question of Avhether tessellatiis ever shows climbing ability is 

 apparently debatable, since there is both positive and negative evi- 

 dence on this subject. Strecker (1910, p. 9) found that "This 

 species is an active climber and unlike gularis never attempts to 

 escape by entering burrows." In fact the only ones that he succeeded 

 in driving to cover were " coiled up under rocks, much after the 

 manner of Crotayhytus collari^'''' (Texas). Further positive sup- 

 l)<)rt of the climbing habit was given l)y liichanlson (1915, p. 425) 

 who said that "It was occasionally observed to climb into bushes" 

 (Nevada). Grinnell and Grinnell (1907, p. ;55), on the other hand, 

 wrote that they had never known the whiptail to climb trees or bushes 

 or even rocks (California). Very recently, Woodbury (1928, ]). 18) 

 has found that the desert whiptail appears to be unable to climb 

 Avell. " One cornered against the side of a frame cabin, in attempt- 

 ing to escape by climbing, fell off and made no further attempt to 

 escape by that method." The "writer's field observations in the 

 Great Basin tend to support the negative side of the question, but it 

 is nevertheless possible that certain individuals may acquire the 

 climbing habit. 



The behavior of this species in water has been recorded by Grin- 

 nell and Storer (1924, p. 032) as follows: "At Smith Creek a small 

 specimen was seen in a pool of water, where it had evidently jiuuped 

 when frightened by the approach of the observer. The animal was 

 obviously unadaptecl to this element, for after a few strokes it sank 

 to the bottom and was drowned." This seems to have a negative 

 bearing on the question of whether such specialized terrestrial forms 

 as these lizards may be conveyed from one land mass to another \y^ 

 flotation. 



Food and feeding habits. — These whiptails are predaceous and 

 chiefly insectivorous. Feeding activity was observed by Ruthven 

 (1907, p. 563), who wrote that this species "was most frequently 

 seen running about among the bushes picking up grasshoppers, 

 beetles, locusts and ants, which constitute the bulk of its food." 

 According to Camp (1916, p. 530), over the rocky hillsides of 

 southern California, " individuals ceaselessly forage, sticking their 

 sharp noses into little piles of leaves and debris or picking up small 

 bits of food with their active tongues." Van Denburgh (1922, p. 535) 

 noted on Isla Partida 12 individuals that were "picking up beetles 

 and other insects which had been uncovered by the removal of 

 stones in a small cleared space about 6 feet square " in a rock slide. 

 Grinnell and Storer (1924, p. 632) found that "The whiptail sub- 



