MAMMALTA. 471 
furnished with hair; a large head, with erect ears; projecting and brilliant 
eyes; the upper lip divided. There are four toes before, with a tubercle 
covered by a blunt nail, and five behind; four molars on each side, above 
and below, variously tubereulated ; a very small additional molar is seen in 
front and above, permanent in some species, but drops out in most cases 
when the young have attained the age of six to twelve weeks; the fingers 
are long, slender, and deeply cleft; the nails very acute, and greatly com- 
pressed. We quote the following description of the habits of the squirrels 
from Audubon and Bachman, Quadrupeds, p. 38: 
‘Squirrels are able to leap from branch to branch, and from tree to tree, 
clinging to the smallest twig, and seldom missing their hold. When this 
happens to be the case, these animals have an instinctive habit of grasping, 
in the descent, at the first object which may present itself; or, if about to 
fall to the earth, they spread themselves out in the manner of the flying 
squirrels, and thus, by presenting a greater resistance to the air, are enabled 
to reach the ground without injury, and, recovering instantaneously, they 
ascend the nearest tree. 
“ All the American species of this genus, as far as we have been able to 
become acquainted with their habits, build their nests either in the fork of 
a tree, or on some secure portion of its branches. The nest is hemispherical 
in shape, and is composed of sticks, leaves, the bark of trees, and various’ 
kinds of mosses and lichens. In the vicinity of these nests, however, they | 
have a still more secure retreat in some hollow tree, to which they retire in 
cold or in very wet weather, and where their first litter of young is generally 
produced. 
“Several species of squirrels collect and hide away food during the abun- 
dant season of autumn, to serve as a winter store. This hoard is composed 
of various kinds of walnuts and hickory nuts, chestnuts, chinquepins, acorns, 
corn, &c., which may be found in their vicinity. The species, however, 
that inhabit the southern portion of the United States, where the ground is 
seldom covered with snow, and where they can always derive a precarious 
support from the seeds, insects, and worms, which they scratch up among 
the leaves, &c., are less provident in this respect; and of all these species, 
the chickaree, or Hudson Bay squirrel (S. hudsonius), is by far the most 
iudustrious, and lays up the greatest quantity of food. 
‘‘TIn the spring, the squirrels shed their hair, which is replaced by a thin- 
ner and less furry coat; during summer, their tails are narrower and less 
feathery than in autumn, when they either receive an entirely new coat, or 
a very great accession of fur; at this season, also, the outer surfaces of the 
ears are more thickly and prominently clothed with fur than in the spring 
and summer. 
‘Squirrels are notorious depredators of Indian corn fields of the farmers, 
in some portions of the country consuming great quantities of this grain, 
and, by tearing off the husks, exposing an immense number of the unripe 
ears to the mouldering influence of the dew and rain.” 
Twenty species of this genus inhabit North America. The common or 
red squirrel (S. hudsonius) has a great geographical range, and extends 
675 
