94 CALIFORNIA MAMMALS. 



rounding fur ; no cheek pouches ; neck short and thick ; legs 

 short ; claws of fore feet largest ; feet not webbtd ; soles naked ; 

 tail haired and very short; form depressed, stout; pelage con- 

 sisting of thick underfur mixed with long hairs. 



Dental formula, I, i— i ; C, o- o; P, 2—1 ; M, 3—3X2=22. 



Aplodontia major Merriam. (Greater.) 



CALIFORNIA MOUNTAIN BEAVER. 



Above from nose to hips, and on the sides grayish sepia 

 brown grizzled with black, the pelage slate colored at base and 

 the long intermixed hairs black tipped ; hips, rump, tail and 

 under parts smoke gray; a small white anal spot; whiskers 

 mostly black.. Young; slate brown. 



Length about 355 mm. (14 inches); tail vertebrc-e 42 

 (1.60) ; hind foot 62 (2.45) ; ear from crown 8 (.32). Weight 

 three to four pounds. 



Tlype locality, Placer County, California. 



California Mountain Beavers occur in isolated localities in 

 the Sierra Nevada and northward, and also in the Siskiyou Moun- 

 tains. I have taken tliem in Alpine Countv, on the eastern slope 

 at the headwaters of Carson River. 



They live in wet springy land in canyons and on mountain 

 sides where suitable springs occiu-, usually at considerable al- 

 titudes. I obtained mine at 8,000 feet altitude. The burrows 

 in most cases ran up and down the wet hillside, for drainage, 

 and often had openings every few feet. Some of the burrows 

 were fifty yards or more in length, and in a few cases spring 

 brooks had broken into the upper entrance and ran in the burrows 

 instead of in their natural channels. In one case a brook was 

 diverted from its own channel to that of one several yards away. 

 Most of the entrances to the burrows were under clumps of wil- 

 lows. Many of the burrows had more or less water running 

 from their lower entrances, but rather the greater number were 

 dry. 



