546 
area around its base. The belly, chin, throat, inner side of legs, 
under side of tail, and usually the toes, are white. The white of the 
feet is modified to a greater or less degree by black hairs, producing 
a grayish color. The ears are sparingly covered with short dusky 
hairs. About one half the whiskers are white. 
In older specimens the color of the upper part is warmed with a 
burnt-umber shade; the cheeks, back of the ears, and a line along 
the side and around the base of the tail become fawn-color; and the 
whole back is warmed to a greater or less degree, often quite equal- 
ing the average P. leucopus in liveliness of color. 
Close examination will show that the base of the hairs is in 
general dark plumbeous, the only exception being the hairs of the 
toes, chin, and under side of tail, which may be white to the base. 
The tips of the hairs over all the under parts are white. Over the 
upper parts there are long hairs tipped with black or dusky, and 
shorter hairs which may acquire more or less of fawn or umber at 
their tips. The colored tips of those nearest the middle line are 
commonly paler and shorter than those of the side, while the black 
hairs are more abundant along the middle of the back. The upper 
surface of the tail may remain dusky or acquire a slightly umber 
tone. The feet usually become more nearly pure white with age. 
Within the county this species is practically limited to the till 
plains and the highly cultivated areas of the moraines. It is em- 
phatically an inhabitant of the open fields, differing from the pre- 
ceding species far more noticeably in its habits than in its structure. 
It is the most characteristic mammal, and the most abundant one, 
of the great fields of the till plains. During late winter, spring, and 
early summer it is nearly the only mammal resident in the center of 
the great corn and grain fields of the county. Other species fre- 
quent the edges of the fields or enter them in fall when the grain 
is ripe, but this species is apparently present in the very center of the 
largest fields, even during those months when, owing to vigorous 
cultivation, the conditions seem most unfavorable. 
The following table illustrates the local distribution of the 
species according to habitat. 
