66 NEW-YORK FAUNA. 
side of the tail. Body above with a rufous tint, the dark slate-colored hairs being tipped with 
that color. On the upper side of the flying membrane, the predominating color is dark brown, 
varied slightly with faint reddish brown, becoming darker near the edge, which is bordered 
with white, and occasionally cream-color. ‘Tail, on its upper surface sometimes bright red- 
dish, at other times uniform with the color of the back. 
Length of head, ....--. 1hOS¥ Of tail (vertebra), ..... 4:0. 
Ditto, of body,-s2e---- op 4-0; Ditto (including fur), ... 5:0. 
The dimensions of this squirrel are usually smaller than in the specimen from which the above 
description was taken. 
The Flying Squirrel is well known throughout this State. The expanded fold of skin is in 
many species supported by a small bone, articulated to the wrist. In the American species, 
this is rudimentary. By the aid of this membrane, they are enabled to dart from one tree to 
another, not by an actual movement of the membrane, as we have seen among bats; but by 
sailing obliquely downwards, and rising suddenly when within a few inches of the tree upon 
which they mean to alight. In this sailing movement, they are aided, and perhaps slightly 
guided by their broadly expanded tail. They form their nests in hollow trees, from which they 
are easily roused by striking on the trunk. They are of a gentle disposition, and easily domes- 
ticated; are fond of warmth, and will sleep during the whole day, closely pressed against the 
body of their master. At twilight they arouse themselves, and afford much entertainment 
by sailing about the room, always commencing their flight by climbing to a chair, table or 
shelf. It brings forth three or four at a litter, and lives exclusively on nuts, seeds and buds. 
It does not appear to be found far beyond the great lakes, but extends through the United 
States. According to Lichtenstein, it occurs in Mexico. 
(EXTRA-LIMITAL.) 
P. sabrinus. (Ricnarpson, Vol. 1, p. 193, pl. 18.) Resembles the preceding, but is ‘much larger. 
Length 12 inches. Arctic America, Sault St. Marie. 
P. oregonensis. (Bacuman, Ac. Sc. Vol. 8, p. 101.) Ears longer than in sabrinus. Brown above, 
beneath white. Length 12 inches; alar extent 9 inches. Oregon. 
FAMILY II. ARCTOMID. 
Head large, and somewhat flattened. Ears short and rounded. Molars ten above and eight 
below ; anterior surface of incisors rounded, the upper surface ridged and tuberculous. 
Body thick and heavy, with short limbs. Tail bushy, moderate or short. Some species 
with cheek pouches. All burrow and hybernate. 
This group, which is closely allied to the Squirrels, comprises many small animals, which 
have been indifferently referred to Squirrels or Marmots. America is particularly rich in 
species, but few are found within the limits of the Union, and but one within our State. 
