328 VERTEBRATE ANIMALS OF THE UNITED STATES 



d-y In the central Rockies and southwestern States S. fremonti. 



C2 On the Pacific slope S. douglasii. 



b2 Size large; color gray, sometimes black. 

 Ci Ears not tufted. 



di In the eastern and central States; common gray squirrel. 5. carolinensis. 



d-i On the Pacific slope 5. griseus. 



C2 Ears tufted with long black hairs. 



di Belly white; ears black 5. aberti. 



d2 Belly dark; ears reddish. 5. kaibabensis. 



ao Upper premolar i in number, making 4 grinders on each side in 

 upper jaw (Fig. 180). 



bi In the eastern and central States; common fox squirrel S. niger. 



bz In Arizona S. apache. 



S. arizonensis. 



S. hudsonicus (Erxleben). Red squirrel. Color reddish brown 

 above and whitish beneath; tail relatively narrow and short; ears 

 tufted in winter; length 315 mm.; tail 115 mm.; hind foot 47 mm.; 

 several litters of young raised a year, from 4 to 6 each: northern 

 America from Labrador to Alaska and British Columbia; southward 

 to Virginia and Tennessee; westward to Utah, eastern Oregon and 

 Washington. 



'Subspecies of S. hudsonicus 



S. h. hudsonicus (Erx.). Colors pale; fringe of tail yellowish: east- 

 ward of Rocky Mountains in Canadian and Hudsonian zones. 



5. h. gymnicus Bangs. Size small; length 290 mm.; outer fringe of 

 tail red; colors deep; belly gray in winter: northeastern States, Canadian 

 zone; southward into New York State, Michigan and Minnesota. 



S. h. loquax Bangs. Outer fringe of tail yellowish; colors pale; 

 belly pure white at all seasons: eastern States, Transition and Upper 

 Austral zones. 



S. h. minnesota Allen. Size large; colors pale; under side of tail 

 gray; length 345 mm.: Minnesota to Iowa, eastward to Indiana. 



S. h. dakotensis Allen. Size large; colors very pale; center of tail 

 yellowish red: Black Hills and Wyoming. 



S. h. haileyi Allen. Fringe of tail black; dorsal band pale; size 

 large: central Wyoming and eastern Montana. 



S. h. ventoriim Allen. End of tail black; size large: Yellowstone 

 Park region into the Wasatch Mountains. 



S. h. nchardsoni Bachman. Upper surface of tail mostly black; 

 size large: western Montana into eastern Washington and Oregon. 



S. h. streatori Allen. Terminal third of tail black: Columbia River, 

 northward into British Columbia. 



