Feb., 1912. Mammals of Illinois and Wisconsin — Cory. 



59 



by new ones which grow rapidly; at first they are soft, full of blood 

 vessels, and provided with a fur-like outer covering known as "velvet." 

 When full growth of the antler is attained, a ring of tubercles appears 

 around the base, which is known as the "burr." This compresses the 

 blood vessels and soon cuts off the supply of blood to the new antler, 

 which quickly hardens and the "velvet" soon wears off. 



KEY TO CxENERA. 



A. End of nose between nostrils almost, or entirely, covered with hair. 

 End of nose entirely covered with hair; antlers palmate (see cut below). 



Genus RANGIFER, p. 80. 



End of nose almost covered with hair (except a narrow slit of bare skin); antlers 



palmate (see cut below). Genus PARALCES, p. 74. 



B. End of nose between nostrils entirely naked. 



Antlers not palmate, most of tines or branches extending from front side of horn 



• (see cut). Genus CERVUS, p. 67. 



Antlers not palmate, most of tines or branches extending from back side of horn 



(see cut). Genus ODOCOILEUS, p. 60. 



KEY TO THE SPECIES. 

 .Skull less than 12 inches long; antlers (in male) less than 30 

 inches long, terminal half or more curved forward (in adult), 

 tines extending from hack side of antler; female without antlers; 

 general body color, reddish brown or grayish brown. 



ViRGiNL\ Deer. White-t.a.iled Deer. 

 Odocoileus virglnianus (Illinois), p. 60. 

 Northern White-tailed Deer. 

 Odocoileus virginianus borealis (Wisconsin), p. 64. 



Skull more than 15 inches long (average adult, 

 18 to 19.50); antlers (in adult) more than 36 inches 

 long, bending backward and with tines or branches 

 extending from front side of antler; antlers not 

 decidedly flattened and palmate. 



American Elk. Cervus canadensis, p. 67. 



Skull more than 15 inches long (average adult, 

 16 to 17}4 inches); antlers large and irregular, most 

 of the numerous branches being flattened and 

 palmate; upper canines usually present; antlers in 

 both sexes; end of nose covered with hair. 



Woodland Caribou. Rangifer caribou, p. 81. 



