502 MONOGRAPHS OF NORTH AMERICAN RODENTIA. 
prominent lobe, bounding the notch posteriorly; and in front of the notch 
there is also a little prominence, just behind the termination of the margin 
of the ear. The flattened portions of the auricle are sparsely pilous inside 
and out, and a tuft of lengthened hairs springs from the front border of 
the ear. i 
The attenuated and. elongated muzzle is densely pilous, excepting a 
small T-shaped nasal pad, divided by a median depression. The upper lip, 
in particular, is thickly covered with stiffish, flaring hairs, completely con- 
cealing any median cleft which may exist, and forming a heavy fringe which 
droops over and almost hides the incisors ; there is an antrorse tuft of bristly 
hairs on the chin. The openings of the cheek-pouches seem to have no 
peculiar character, being much as in other species of the genus; the cavity 
admits the first joint of one’s little finger. The whiskers are very numerous 
and fine; the shorter colorless ones seem like mere lengthening of the hairs of 
the muzzle; others, stiffer and colored, reach rather beyond the head. 
There are also some long special bristles over the eye, and others between 
the eye and ear 
The palm proper, and under surfaces of the digits, are perfectly naked, 
though a considerable fringe of hairs falls down from the wrist. There is a 
large and conspicuous smooth tubercle on the outer side, at the base of the 
fifth digit ; two others, one on each side, at the wrist, and others at the bases 
of the intermediate digits; the disposition of these smaller ones is not very 
evident in the dried specimens. ‘The thumb is rudimentary, a mere stump, 
hearing a flattened obtuse nail; the other digits are armed with ordinary 
compressed, acute, and moderately curved claws; the 3d is longest; then 
come 4th, 2d, and 5th in succession. Of the hind foot, the sole is perfectly 
naked for its whole length along a median strip, narrowed by encroachment 
on either side of a fringe of hairs. On the outer side, about half-way from 
heel to base of digits, is a small tubercle; there is another near the base of 
the 1st digit, and a much larger one near the base of the 5th digit, with others 
still at the bases of the intermediate digits; but their precise disposition, and 
the character of the naked sole, cannot be made out perfectly. The first digit 
is very small, with a smooth bulbous end and short blunt claw; the other 
claws are of a more ordinary character, but. relatively shorter,” blunter, less 
compressed, and less curved than those of the hand; they are excavated 
underneath. 
