1916] Taylor: Beavers of Western North America 467 



California on the north, occupying the Transition and Upper Sonoran 

 zones along its northern border. The vicinity of Pit River, Shasta 

 County, is its southern limit. Occupying both Lower and Upper 

 Sonoran and Transition of the rest of the state except the southeastern 

 deserts, is Procyon psora psora, the California raccoon, which is very 

 closely related to its northern neighbor, and doubtless intergrades 

 with it. Favorable situations in the southeastern desert region are 

 inhabited by the pallid raccoon, Procyon pallidus, while a fourth 

 California form has recently been described from the San Diegan 

 region west of the Coast Range Mountains in extreme southwestern 

 California {Procyon psora calif ornicus, Mearns, 1914, p. 66). 



MUSTELIllAE 



The closest ally of Martes caurina caurina, the pine marten, the 

 range of which includes the Transition and Boreal of northwestern 

 California, is Martes caurina origenes which is found in the Boreal of 

 the Rocky Mountains of Colorado (Cary, 1911, p. 189). Martes pen- 

 nanti pacifica, the Pacific fisher, finds its closest living relative in 

 Martes pennanti pennanti of eastern Canada. The Sierra Nevada 

 and Mount McKinley wolverines, Gulo luscus luteus and Gulo luscus 

 hylaeus, are closely related, and both are close to the Gulo luscus 

 luscus of Canada. 



Details of distribution and relationships of the weasels are hardly 

 complete enough to be satisfactory. However, it is certain that the 

 diminutive Mustela muricus of the Sierra Nevada is a member of the 

 boreal cicognanii group of weasels. A close ally of muricus is resi- 

 dent on the Pine Forest Mountains of northern Nevada. An unde- 

 scribed weasel most closely related to Mustela streatori of the Piiget 

 Sound district occurs on the north coast of California. The Mush In 

 arizonensis is said (Merriam, 1896, p. 22) to be a mountain form of 

 Mustela longicauda of the Great Plains from Kansas northward. 

 Mustela arizonensis is found in the Transition and Boreal zones of the 

 Sierra Nevada from Mount Shasta to Tulare County, as well as on 

 the San Jacinto Mountains. Its distribution is stated as follows: 

 "Broadly, the Sierra Nevada and Rocky mountain systems, reaching 

 British Columbia in the Rocky Mountain region, but not known north 

 of the Siskiyou Mountains in the Sierra-Cascade system". North of 

 the Siskiyou Mountains in the Sierra-Cascade system occurs its close 

 relative, Mustela saturata. The relationships of arizonensis are not 

 clear, since Merriam states (op. cit., p. 23) that Sierra specimens 



