198 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
The soles are over an inch long, and thoroughly furry as far as the posterior 
tubercle; naked in the rest of their length. There are six conspicuous 
tubercles, as usual in this section: a posterior one at base of hallux; two 
at base of outer toe; one at base of second toe; and one at bases of third 
and fourth toes. The fore feet are comparatively small, being obviously less 
than half the hind (measured from the posterior tubercle). There are five 
palmar tubercles: one representing the “ball” of the rudimentary thumb, 
which bears a minute abortive nail; another just beside and external to the 
first; one at the base of each lateral finger; and one at the bases of the two 
central fingers. The relative proportions of all the ten digits is as usual in 
this section. The ears are moderate for the size of the animal, measuring 
a little over half an inch high and wide; they overtop the fur a little, are well 
furred both sides, rounded in shape, and with a highly-developed antitragus 
fully occluding the meatus. The fur, much as in other Arctic Arvicole, is 
longer, thicker, and softer than that of United States species; and, although 
the reverse of harsh, has very little lustre, apparently owing to the less 
admixture of the long, glossy, bristle-like hairs that occur so abundantly in 
southern samples, especially of maritime or very wet places. The longest 
whiskers about equal the head; others are much shorter. 
In color, this animal represents one of the few species, that may usually 
be known at a glance, and the only one of ours that has bright tints in 
sharply restricted areas. The cheeks are bright chestnut,* in marked contrast 
with surrounding shades. The extreme muzzle is blackish, and thence to 
over the eyes a dusky shade prevails. In some specimens, there is a small 
rusty or yellowish-brown orbital space, and there is generally a perceptible 
shade of the same on the auricular region, though we have never appreciated 
so much of this as Audubon’s smaller figure shows. The upper parts are of 
an intimate mixture or ‘‘grizzle” of yellowish-brown, gray, and black, some- 
what darkest along the middle line of the back, and brightest on the haunches, 
but not noticeably far from uniform all over. The resulting shade is generally 
lighter or more yellowish-brownish-gray than in southern species, owing to 
smaller proportion of long dark hairs. The tail is bicolor, but not very 
sharply so—more so in some specimens than in others; the feet are fuscous. 
*The name ‘‘xanthognatha”, ‘yellow ”-checked, and the descriptions of authors, as “ yellow”, 
“orange brown”, “fulvous”, &c., do not correctly indicate the color as it appears to our eyes. We can 
seo nothing but a bright bay or chestnut, and the shade scarcely varies appreciably in any of the speci- 
mens examined in which it is evident at all. 
