72 RODENTS. 
spiny squirrel (Y. lewcowmbrinus) agrees with the last in having external ear- 
conchs, but differs in its longitudinally-striped body; in the latter respect it re- 
sembles the Cape spiny squirrel CY. setosus), of South Africa, in which, however, 
the conchs of the ears are wanting. The small spiny squirrel (Y. getulus), which 
is also striped, is the most diminutive member of the group, and in size and appear- 
ance much resembles the Indian palm-squirrel. A fossil species of this genus occurs 
in the Miocene deposits of France. 
THE TRUE SQUIRRELS. 
Genus Sciwrus. 
The common squirrel is the sole representative in Western Europe of an ex- 
ceedingly large and widely-distributed genus, of which the following are the leading 
characteristics. The tail is very long and bushy; the ears are in most cases of 
considerable size, and may be surmounted with tufts of long hair; and in the fore- 
limbs there are only four functional toes, owing to the rudimental condition of the 
one corresponding to the human thumb. ‘The claws are long, curved, and sharp ; 
while the female may have either four or six teats. From that of the spiny 
squirrels the skull differs by its shortened form and the elongation of the backwardly- 
directed (postorbital) processes defining the hinder border of the sockets of the eyes. 
The molar teeth are low-crowned and of a simple type, those of the lower jaw having 
the grinding surface basin-shaped, with a longitudinal wall on the inner and outer 
side, and no transverse plates formed by infoldings of the enamel; and the first 
upper premolar, if present, is small, and may be shed at an early age. 
While the common squirrel is of a uniform brownish red colour on the upper- 
parts, many of the tropical species are most brilliantly tinted with orange and other 
bright colours, while others, like the little Indian palm-squirrel, have their bodies 
ornamented with longitudinal light stripes on a dark ground. One of the Malayan 
species, which is ordinarily grey, assumes a brilliant crange-coloured dress during 
the breeding-season; and some of the North American species also undergo a 
seasonal change of coloration, one of them having a dark stripe along the sides of 
the body in summer, which completely disappears in winter. There is great differ- 
ence in the size of the various species, the large Malayan squirrel (Sciwrus bicolor) 
from India and the Malay region, measuring about 40 inches or more in total length, 
while the Indian palm-squirrel does not exceed a weasel in size. 
The true squirrels inhabit the temperate and tropical portions of 
the whole globe, with the exception of Madagascar and the Australasian 
region. The number of species probably does not fall far short of fifty or sixty, 
and these are most numerous in the Malayan region, which may be regarded as the 
Distribution. 
headquarters of the group. There is, however, great difficulty in deciding as to 
the real number of species, since a large number of squirrels, especially those from 
North America and Africa, exhibit extraordinary local variation in coloration, so 
that it is almost impossible to say where varieties end and species begin. 
European The common squirrel (S. vulgaris), as being the best known 
Squirrel. representative of the genus, may be selected for special notice, as the 
