GITELLUS Wan 
eastwards to the Central United States, and from Arctic 
Alaska southwards to Central Mexico. Although obviously 
of ancient standing, no fossil remains of the genus have been 
found, in either Eurasia or America, in deposits older than 
the Pleistocene. 
The members of the genus C7zte//us may be regarded as 
degenerate squirrels. They have forsaken arboreal habits, 
and have colonised the treeless wastes. In these desert places 
they are strictly earth-bound animals, leading a great part 
of their lives in their burrows, and subsisting upon coarse 
herbage, varied with bulbs, seeds, and grain when available. 
They devour large numbers of insects, and like the true 
Squirrels betray carnivorous tastes whenever an opportunity 
presents itself. They form subterranean stores of provisions 
for use in inclement weather. In warm countries they remain 
active at all seasons of the year, but throughout the greater 
part of their range the Sousliks hibernate regularly, remaining 
in a torpid state in cold regions for a period of six months 
or more. 
The acquisition of such habits has, of course, brought 
about a good deal of modification in bodily structure. Sousliks 
are animals of medium size. In general outward form they 
are essentially of sciurine aspect, although they are more 
robustly built than are most arboreal squirrels, and have 
relatively shorter peripheral parts. The fur is thin, coarse, 
and adpressed. The eyes are large. The ears very small 
(except in some American forms), clothed with numerous 
short and fine hairs, but without tufts. Cheek-pouches are 
present. The limbs are much shorter than in Sczurus, and 
in both hands and feet digit 3, instead of digit 4, is the longest. 
The vestigial thumb bears a small flattened nail; the other 
fingers are long, and armed with long, strong, and rather 
straight claws well adapted for digging. In the foot all 
five toes possess similarly shaped though shorter claws. The 
palms and soles, except towards the heel, are naked; on the 
palm there are five pads, on the sole four, the posterior two 
being absent; the under surfaces of the digits are annulated. 
The upper surfaces of hands and feet are well clothed with 
numerous long hairs which show a tendency to develop as 
