CROCODILIANS, LIZARDS, AND SNAKES. 547 



The legs are rather short, covered with tubercles like those on the 

 back except on the upper surface of the humerus and the anterior oC 

 the forearm and thigh and under surfa(!e of tibia, which are co\ered 

 with large plates. The femoral pores, nine or ten in number, are not 

 conspicuous. The digits are short; the fourth hind toe not much longer 

 than the third; its free portion only half the head from snout to oar. 



In his report on the reptiles of the Death Valley expedition, Dr. 

 Stejneger remarks: 



Two additioual specimens are now before us, one collected by Dr. Fisher at Hes- 

 })eria, on the south side of the Mohave Desert, on January 4, 1891, while Mr. I'alnicr 

 secured the other on February 24, in Pahrump Valley, Nevada, thus extending the 

 range of the species nearly 200 miles eastward. The type locality, Fort Tejon, is in 

 an open canon — the celebrated Canada de las Uvas of the early exploring exi)edi- 

 tions — connecting the west end of the Mohave Desert with the San Joaquin Valley. 

 The fauna and flora of this canon present a mixture of Mohave Desert and interior 

 valley forms. 



In all probability this species is more or less nocturnal in habits, which may 

 account for the scarcity of specimens collected. 



Both specimens are somewhat larger than the largest of the types, and, judging 

 from the condition of the femoral pores, I take them to be adults. 



There appears to be some slight variation in the shape of the individual liead 

 shields and in the shape of the head, the Death Valley expedition specimens having 

 it somewhat more elongate; but the differences are not greater tliau between the 

 type specimens themselves. 



Mr. J. Van Deuburgh ' states further that — 

 X vigilis is the most abundant lizard in the territory it has chosen for its home. It 

 seems to be peculiarly dependent upon the presence of tree yuccas. A glance at Dr. 

 Merriam's map (N. Amer. Fauna, No. 7, map 5,1893) shows that these weird i>lau(s 

 grow in each of the localities from which the species has been recorded, viz: Fort 

 Tejon in the Canada do las Uvas, and Hesperia, in California, and in the Pahinmp 

 Valley in Nevada. 



Dr. C. II. Gilbert and the writer collected specimens near Mojave, and found a 

 portion of a cast skiu at Victor, California, in November, 1893. In September of the 

 following year the writer found this species common at Mojave and Hesperia, and 

 secured a single specimen near Cabazou on the eastern slope of San Gorgonio Pass, 

 California. The first three of these localities are situated in the great Yucca arhores- 

 cens belt, which extends along the southwestern edge of the Mojave Desert. The 

 last is in a small and apparently isolated grove of smaller tree yuccas, seemingly of 

 another species. 



Habits. — These observations were made in the neighborhood of Mojave, California, 

 November 4, 1893. About a mile from the station there is a considerable forest of 

 Yucca ayhoresccns. The many trees and wind-l)rokeu branches which lie decaying 

 on the ground afford a home to numerous colonies of white ants, scorpions, vicious- 

 looking black spiders, and several species of beetles. In a deep crack of one of 

 these branches a small lizard was discovered, which, when caught, proved to be a 

 young Xantunia rujilis. Probably it had not yet learned how to hide from the day, 

 for I have never seen another undisturbed individual. 



The key to their home once discovered, the collection of a large series of these 

 lizards was merely a matter of physical exertion. Every fourth or fiftli stem that 

 was examined gave up its Xanfiisia, and, in one instance, as many as were ])reviou8ly 

 known to collections were found under a single tree. 



Most of the lizards wore fouiul between the bark and the ground, but many had 



■ Proc. Cal. Acad. Sci. (2), V, 1895, p. 523. 



