352 University of California Publications in Zoology. ["Vol. 7 



Our records are the first for the northern part of Nevada 

 known to me. Van Denburgh (1897, p. 99) states that platy- 

 rhinos crosses Nevada and ranges into Utah, and lists a series of 

 localities in the southern part of the state. Pyramid Lake being 

 the most northerly one mentioned. It is said to inhabit Idaho, 

 also, so one would expect to find it in northern Nevada. 



Habits. — Sand was adherent to the back of one horned lizard 

 secured, as if it had recently been covered. Another individual 

 was found in a hole with only its head protruding. All ap- 

 pearances lead to the conclusion that the animal had made the 

 hole, or had at least remodeled it, for earth had recently been 

 thrown out and tracks of the horned lizard were seen in the 

 entrance. The animals were found on sandy, on loamy, and on 

 sun-baked hard soil. One horned lizard, upon being picked up, 

 opened its mouth and made a hissing sound. 



Of three individuals taken July 3 on Big Creek, two were 

 shedding their epidermis. 



A pair of horned lizards were observed copulating on June 10. 

 On June 14 a female containing ten eggs was taken. 



Cnemidophorus tigris Baird and Girard 



Desert Whip-tailed Lizard 



Distribution. — The thirty-six specimens of this lizard in the 

 collection of the expedition came from the vicinity of Big Creek 

 Eanch (4350 feet). "We looked in vain for the species on the 

 open desert in the vicinity of Quinn River Crossing. Evidently 

 a strip of land immediately adjoining the foothills is either the 

 only place inhabited by it, or at least is much preferred. It is 

 rather peculiar that whip-tailed lizards were not recorded from 

 Alder Creek Ranch on the west side of the mountains. A 

 number of facts of distribution, of which this is one, show that 

 Alder Creek Ranch differs environmentally to an appreciable 

 degree from Big Creek Ranch. 



The latter locality is Upper Sonoran zone (see C. Hart Mer- 

 riam, in Stejneger, 1893, p. 199), in some respects approaching 

 Lower Transition. 



The most northerly part of Nevada from which I have found 



