MAMMALIA 



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the common name, Bighorn. It is very sure-footed and can live on 

 mountain ledges. The Rocky Mountain goat, Oreamnos montanus, 

 lives in a similar habitat, but farther north. It has short, dark 

 horns, shaggy wool, and a beard. The musk ox, Ovibos moschatus, 

 is a heavy bodied, hump-shouldered animal with stout, down-curved 

 horns. It lives above the timberline, principally in Canada and 



Fig. 342. — Bighorn mountain sheep are still to be found in the Rockies. (Courtesy 



of Nature Magazine.) 



Alaska. The buffalo. Bison americanus, was extremely abundant all 

 over the Great Plains until the last quarter of the nineteenth century 

 when they were killed out by hunters and crowded out by civilization. 

 They are powerful, heavy-headed, hump-shouldered animals. There 

 are still a few herds, such as the one at Yellowstone National Park, 

 that are kept under semidomesticated conditions. Our domesticated 



