232 U diversify of California Fuhlications in Zoology. [Vol.7 



Distribution. — Onr specimens of Peromyscus ^nanivuJatiis 

 so)ioriensis were recorded as follows: Quinn River Crossing (4100 

 feet), 18; Big Creek Ranch (4350 feet), 3; head of Big Creek 

 (8000 feet), 60; Big Creek (6000 to 7000 feet), 6; Duffer Peak 

 (8400 to 0400 feet). 12; Alder Creek (5000 to 7000 feet), 8; 

 Leonard Creek (6500 feet), 7; Virgin Valley (5000 feet), 9. 

 These localities range from Upper Sonoran to Canadian, if any 

 of this life-zone is actually represented on the Pine Forest ]\Ioun- 

 tains. They were more abundant at the head of Big Creek 

 (Transition) than at any other place we visited. 



In the list of localities from which specimens of sono7nensis 

 were examined, Osgood includes Granite Creek (Granite Range, 

 Washoe County) ; Cottonwood Range (the Santa Rosa IMountains 

 of the topographic ma{)s of the United States Geological Survey) 

 near Amos ; MacDermitt, which lies a little north of east of 

 Quinn River Crossing over several low ranges of desert moun- 

 tains near the Oregon line ; Summit Lake, lying west of the Pine 

 Forest Range, and Winnemucca. The species is universally 

 distributed over the northern part of the Great Basin, being 

 found wherever any terrestrial mammals of any kind have been 

 taken. 



Habits. — White-footed mice were found in every available 

 type of environment (see Osgood, 1909, p. 26). On June 26, 

 at the head of Big Creek, altitude 8000 feet, a Peromyscus was 

 caught four feet from the stream near a white-bark pine, on 

 very moist ground. Another was captured in grass under a sage- 

 bush, twenty feet from water. Others were caught all the way 

 U{) to the top of the dry and barren ridge, a single individual 

 l)eing taken among the rocks in the latter situation. iVlany were 

 caught near small holes, and some beside rocks, under which, or 

 in burrows near which, they appeared to live. The mice were 

 caught in willows at the lowest point touched by the Expedition, 

 Quiini ixiver- Crossing (4100 feet), and at the highest ]M)iiit. 

 namely, the rocky pine-covered ridge forming what is l<ii()wii as 

 DufPer Peak (9400 feet). A list of the enviroinnents inchules 

 the following: (1) dry, sandy washes; (2) moist grassy 

 meadows; (.3) the o])en desert at a considerable dislaiice fi'om the 

 stream; (4) the banks of the Quinn River, in willows and other 



