MAMMALS 353 



Subspecies of S. sahrinus 



S. s. macrotis Mearns. Color more reddish: northern New York 

 and New England. 



S. s. siliis Bangs. Size small; length 214 mm.; color brown above: 

 the higher southern Alleghanies. 



S. alpinus (Richardson). Body large and yellowish brown in color; 

 whitish beneath; length 309 mm.; tail 143 mm.; hind foot 40 mm.: 

 the Rocky Mountains from the Mackensie River to Colorado, the 

 Great Basin and the Pacific slope. 



Subspecies of S. alpinus 



S. a. bangsi Rhoads. Color olive brown: Idaho County, Idaho. 



S. a. olympicus Elliot. Color blackish slate; length 346 mm.: 

 Olympic Mountains, Washington. 



5. a. oregonensis (Bachman). Colors dark; length 302 mm.: 

 northern California to Alaska, in pine forests near the coast. 



S. a. fuliginosus Rhoads. Color reddish brown; length 317 mm.: 

 Cascade, Sierra Nevada and Coast Mountains. 



S. a. klamathensis Merriam. Color brown tinged with fulvous: 

 region of the Klamath Lakes. 



S. a. calif ornicus Rhoads. Color pale; length 286 mm.: San Berna- 

 dino Mountains, CaUfornia. 



5. a. lascivus Bangs. Color much darker than 5. a, calif ornicus; 

 length 300 mm.: Eldorado County, California. 



S. a. stephensi Merr. Like S. a. klamathensis but darker and smaller: 

 Mendocino County, California. 



Family 8. Castoridae.- — Beavers. Large, stout rodents with a 

 large flattened and scaly tail; all feet with 4 toes; hind feet webbed 

 and with a double-clawed second toe; dentition i/i, 0/0, i/i, T)!?)'- 

 I genus. 



Castor L. With the characters of the family: i American species. 



C. canadensis Kuhl. Body covered with a dense, soft fur and dark 

 brown in color; length 1,100 mm.; tail 410 mm.; hind foot 175 mm.; 

 average weight 35 lbs.: North America from Hudson Bay and Alaska 

 into the southern Alleghanies in the east and into Mexico in the west; 

 exterminated in well-settled regions. Beavers are aquatic and noc- 

 turnal, and feed on bark and twigs. The nest is usually in a conical 

 lodge built of sticks and mud in a pond formed by throwing a dam of 

 sticks and earth across a stream. Along streams with high banks the 

 nest is often a chamber in the bank above the water level, and con- 



