MAMMALIA. 449 



a hollow liorn {cavicornia). The bony prominence which it envelopes, and 

 which grows with it, never falls, and remains permanently through life. 

 Such are the horns of oxen, siieep, goats, and antelopes. 



In othei's, the bony prominences are covered for a time with a hairy skin, 

 similar to that of the rest of the head, but have at their base a ring of bony 

 tubercles, which, as they enlarge, obliterate the vessels which carry the 

 fluid to that skin. Tlie latter becomes dry, and is cast off, the bony promi- 

 nences being left bare, and after a certain period separate from the cranium 

 to which they were attached ; they fall olf, and the animal remains for a 

 time defenceless, '^rhey are reproduced, and generally larger than before, 

 and again destined to undergo the same fate. Such horns, purely osseous, 

 and subject to periodical changes, are styled antlers. Stags, deer, &c., 

 bear antlers. We have referred to this subject in the introduction to the 

 present article (p. 393). 



Fam. 4. Oervid.e. Very nunierous in species, and containing ruminants 

 with a slender stature, a short tail, and an elegant body, possessing eight 

 incisors in the lower jaw, and none at all in the upper one ; the feet are 

 bisulcated, but the posterior toes are not always developed, and in that case 

 the antlers are also absent. The antlers consist of a solid bony mass, 

 branching off several times, and differently, according to the genera. Often 

 it is the male alone wliich is provided with these appendages •, but in a few 

 species they are developed in both sexes. These animals are exceedingly 

 fleet, live commonly in the forests, and feed on leaves, buds, grasses, &c. 

 The genera contain generally numerous species, distributed over the whole 

 world. Fossil remains of this family are found in profusion in the meio- 

 cene deposits. 



The genus Cervii-s (the deer) exhibits constantly horns in the male, 

 branched, subpalmated, or simple, rounded at their root. The ears are large ; 

 there are no canine teeth at all ; the tail is short and bushy. The American 

 species of this genus are the following : 



1. The common or American deer (G. virginianm) is reddish or bluish- 

 grey, according to the season. The young are spotted with white. The 

 horns are moderate, curving forwards, with the concave part turned in 

 front, provided with from one t(j six points, occasionally palmated. 



2. The black-tailed deer (61 macrotis) is greyish, with a black-tipped tail, 

 large ears, and horns with three branches ; the forehead is dark-brown. This 

 species is larger than the common deer {Ö. virginkmus), and inhabits the 

 plains of Missouri. 



3. The long-tailed deer {C. leucurus) is reddish-brown in summer, light- 

 grey in winter. The tail is long, white beneath and at the tip. It is 

 smaller than the common deer, and inhabits the Kocky Mountains. It 

 resembles most the roebuck of Europe {G. capreolus), represented on pL 

 107, fig. 4, which lives in couples and inhabits the high mountains of 

 the temperate part of Europe. The flesh is held in much better esteem 

 than that of the common deer, 



Cervus richardsonii is a species nearly like the black-tailed deer, and 

 inhabiting the plains of the Columbia. 



663 



