534 
It ‘‘flies,’ in long sailing leaps, by means of an extension 
of a fold of skin along each side of the body and the neck. 
There are two parts to this parachute. The larger part extends be- 
tween the fore and hind limbs, and is held taut by a cartilaginous 
rod extending from the wrist backward, between the folds of skin, 
and also by specially developed dermal muscles. The other mem- 
brane fills the triangular space between the fore limb and the neck 
and side of the head. This is held taut by muscles, the chief one of 
which arises from the zymotic arch and is attached to the rudimen- 
tary thumb. . 
The flying squirrel can not be mistaken for anything else. Of 
all the mammals found in the county, none is more beautiful or 
interesting, and yet, considering its abundance, none is perhaps so 
little known. This is due chiefly to the fact that it 1s among the 
most strictly nocturnal of animals—quite as much so as bats or 
owls—and is, moreover, so quiet and inconspicuous in its move- 
ments that it is seldom seen. A nest may remain undiscovered by 
the passers-by even in a much frequented locality. On the other 
hand, as there are usually a number of animals in the same nest, the 
ordinary observer who finds a colony by accident is quite sure to 
have an exaggerated idea of their abundance. For this reason little 
reliance is to be placed on popular report of their numbers. I 
have obtained but few reports and observations concerning the 
presence of the species in the county; nevertheless, considering: how 
nearly the individuals I have observed escaped detection, I am of 
the opinion that flying squirrels may be said to be fairly abundant 
even in the neighborhood of Urbana and Champaign. 
Kennicott and the majority of early observers mention deep 
woods or large groves as the habitat of this species. J have never 
known of their being found in the groves scattered over the prairie, 
but they occur in the large woods and in the little clumps of trees 
that represent the ragged fringing remnant of the wooded-bluff 
region. Here they are found, several together, nesting in hollow 
trees.* In other parts of the country they build nests of leaves 
lined with softer material; or, more rarely, they build them entirely 
of such softer substances as grass, fine bark, etc. JI have no record, 
however, of such nests within Champaign county,.or even within 
* I have run as many as fifty out of one den.— Dr. J. Schneck, 1886, Mt. 
Carmel, Il. 
