MAMMALS 357 



800-1,400 lbs., and more: forests of North America from northern 

 Maine and New Brunswick to northern Michigan and North Dakota; 

 northward to Hudson Bay and Alaska; in the Rockies into jMontana 

 and Idaho; a near relative of the European elk, A. alces. 



A. a. shirasi Nelson. Smaller, with small hoofs; color pale brown 

 along the back; ears pale: Yellowstone Park region. 



4. Rangifer H. Smith. Antlers large and borne by both sexes, 

 palmate near the tips; one or both brow-prongs palmate and extending 

 over the face ; dentition 0/4, i/o, 3/3, ^/^ ; legs and tail short : 1 2 species, 

 I in Asia and Europe, the reindeer R. tarandus (L.), and 11 in northern 

 America which range throughout the Canadian, Hudsonian and Arctic 

 zones; 2 species in the United States. 



R. caribou (Gmelin). Woodland caribou. Color dark brown, 

 sometimes reddish, on the back, head, sides and outsides of legs; under 

 parts, rump and a band around each foot pure white; in winter, neck 

 white, body gray; length 1,800 mm.; tail 100 mm.; weight 280 lbs.; 

 height at shoulders 1,200 mm.: forests of northern Maine and New 

 Brunswick; northward to Great Slave Lake and Hudson Bay; much 

 less gregareous than the Barren-ground caribou (R. arcticus Richard- 

 son), which ranges over the Arctic barrens to beyond the Arctic Circle. 



R. montanus Seton. Color dark brown; under parts grayish white; 

 length 2,413 mm.; tail 177 mm.; height at shoulders 1,397 mm.; weight 

 500 lbs.: Rocky Mountain region from Alaska into Idaho, Washington 

 and Montana. 



Subdivision 2. Cavicornia. Ruminants with hollow horns, com- 

 posed of horn, in both sexes, which are never shed, except in Antilo- 

 capra: 2 families. 



Key to the Families of Cavicornia 



ai Horns branched i. Antilocapridce. 



a2 Horns not branched 2. BovidcB. 



Family i. Antilocapridae. — Antelopes with erect horns, each with 

 a short branch in front, which are shed each summer; ears long and 

 pointed; lateral hoofs absent, digits 3 and 4 only present; dentition 

 0/4, 0/0, 3/3, 3/3: I genus. 



Antilocapra Ord. With the characters of the family: i species. 



A. americana (Ord). Prong-horn antelope. Color light yellowish 

 brown; under parts, rump, sides of head and spot behind ears white; 

 length 1,350 mm.; tail 138 mm.; height at shoulder 850 mm.; weight 125 

 lbs.; length of horns 250 mm.; number of young at a birth usually 2: 

 Great Plains and deserts from the Saskatchewan into Mexico; west- 

 ward to the Rockies and into eastern Oregon and California. 



