450 University of California Publications in Zoology [Voi. 12 



Fig. J. Dorsal view crania of Castor canadensis leucodonta and Castor 

 subauratus subauratus. Note the different outline of the nasals 

 and interparietal; the different conformation of the temporal 

 ridges and the external auditory meatus; and the more massive 

 character of the skull of the golden beaver. Approximately 

 two-thirds natural size. 



a. Castor canadensis leucodonta, no. 12107, 2, Mus. Vert. Zool.; 



Alberni, Vancouver Island, British Columbia. 



b. Castor subauratus subauratus, no. 12654, 5, Mus. Vert. Zool.; 



Grayson, San Joaquin River, Stanislaus County, California. 



