MAMMALIA. 449 
a hollow horn (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, sheep, goats, and antelopes. 
In others, 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. The 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 off, and the animal remains for a 
time defenceless. They 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. 398). 
Fam. 4. Cervinos. Very numerous 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 which 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 Cervus (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 (C. virginianus) 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 to six points, occasionally palmated. 
2. The black-tailed deer (C. 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 (C. virginianus), and inhabits the 
plains of Missouri. 
8. The long-tailed deer (C. lewcurus) 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 Rocky Mountains. It 
resembles most the roebuck of Europe (C. capreolus), represented on pi. 
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. 
653 
