NORTH AMERICA AND THE WEST INDIES 81 



rostrum; angle between side of rostrum and zygomatic arch 

 obtuse, so much so as closely to approach a straight line; 

 nasals anteriorly narrow and pointed." The slight cranial 

 peculiarities on which this form is mainly based are not very 

 striking, but are shown in comparison with skulls of five other 

 races in the figures accompanying the paper by Benson cited 

 above; he also makes brief comparisons of its characters with 

 those of the surrounding western races, and presents tables of 

 cranial measurements. 



This race is "known only from the Cariboo Range, in east- 

 central British Columbia." It is supposed, however, that it 

 meets the range of typical C. canadensis in the mountains, 

 while in south-central British Columbia it probably intergrades 

 with the race pacificus, and Davis has lately identified as of 

 this race a skull from northern Idaho. Presumably, too, its 

 range meets that of being ae "in the northern portion of the 

 Eraser River drainage system." Concerning its general status 

 in the east-central part of British Columbia little information 

 is at hand, but according to Benson it apparently exists in 

 considerable numbers in the mountains of this region. Cowan 

 (1939) in his recent account of the vertebrates of the Peace 

 River district, British Columbia, writes of the beaver, which 

 evidently represents this race, that it is "rare over most of the 

 district but according to reports of trappers increasing on 

 certain areas thanks to the combined efforts of the game 

 wardens and certain of the more intelligent trappers." He 

 mentions that a large female from South Pine, British Colum- 

 bia, and a yearling male from Pine River are typical of cana- 

 densis and exhibit no trace of intergradation with sagittatus, 

 the race to the west of the mountains. 



SHASTA BEAVER 

 CASTOR CANADENSIS SHASTENSIS Taylor 



Castor subauratus shastensis Taylor, Univ. California Publ. Zool., vol. 12, p. 433, 

 Mar. 20, 1916 ("Cassel [Hat Creek], Pit River, Shasta County, California"). 



This race is based on cranial characters of relatively slight 

 significance. It is closely similar to the race subauratus but 

 although occurring in the same drainage basin, is found on the 

 eastern or Great Basin side of the Sierra Nevada. The distinc- 

 tion is based mainly on the outline of the nasal bones, which 



