630 ANIMAL LIFE IN THE YOSEMITE 



to be gathered mostly on the ground; sometimes one of the lizards may 

 be seen running about on the surface of a fallen tree trunk in search 

 of flies and other insects which may be sunning themselves on the rough 

 bark. 



California Horned Toad. Phrynosoma blainvillii frontale Van Denburgh 



Field characters. — Body broad and flattened, more than twice as broad as thick, 

 and decidedly oval in outline as seen from above; a row of long slender spines (the 

 'horns') across back of head; other rows of shorter blunt spines on sides of head, and 

 a double row of short spines along each side of body and tail ; back with scattered short 

 pointed spines of various sizes. Under surface of body with smooth scales. Coloration 

 variable, but above usually dusky yellow with a double row of large black patches on 

 back; under surface yellowish, sometimes with small dusky spots. 



Occurrence. — Sparse resident in lower western portions of Yosemite section. Known 

 to occur on plains of San Joaquin. Valley and found by us near Smith Creek, east of 

 Coulterville. Reported at Kinsley. Inhabits open sandy ground. 



The California Horned Toad, which is, of course, not a toad (an am- 

 phibian), is so distinctive in appearance that it cannot be confused with 

 any other animal in the region. It is, perhaps, the best known of all the 

 western lizards, and is present in small numbers in the western part of 

 the Yosemite region. The general scarcity of suitable surroundings is 

 undoubtedly the factor which limits the numbers of this animal here. The 

 plains of the San Joaquin Valley where not entirely taken over for agri- 

 culture are tenanted by horned toads, and a few dry sandy spots in the 

 foothills also harbor a small population. 



Occasional adults of the present species reach a total length of 5 inches, 

 though most of the individuals met with are somewhat smaller. The one 

 specimen obtained by our field party was found near Smith Creek, at 

 about 3000 feet altitude, on June 2, 1915, It measured only 21/2 inches 

 in length and was probably a young of the previous year's brood. Its 

 stomach upon examination was found to contain 15 ground beetles meas- 

 uring about % inch (7-10 mm.) in length, 2 ants, an unidentified larval 

 insect, and a small pebble, the latter doubtless taken by accident. 



Alligator Lizards. Genus Gerrhonotus" 



Field characters. — Size large for a lizard, up to 12 inches, legs small ; head large 

 and diamond shaped; iris light yellow; body covered above and on sides with keeled 

 scales in 14 or 16 lengthwise rows (pi. 58b, c, d) ; a flexible fold of skin, covered with 

 granules, along each side of body; scales on under surface smooth and in rows longth- 



41 Two distinct species of Alligator Lizards live in the Yosemite region. They are 

 similar to one another in general appearance, and little or nothing concerning possible 

 differences in their habits is known. For these reasons they are here treated together. 



San Diego Alligator Lizard, Gerrhonotvs scincicauda webhii Baird, a southern form 

 which ranges north along the western flank of the Sierra Nevada, is found in the western 



