SACCOMYIDA2—PEROGNATHIDINAI—C. FLAVUS. ST 
especially in the frontal region, tapering to a bluntly conical snout, which is 
densely hairy excepting a minute nasal pad; the upper lip is heavily pilous 
with a fringe of hairs which droop over and hide the incisors. The eye is 
rather small, and nearer to the ear than to the nose. The whiskers are very 
numerous and fine, the longest exceeding the head. On the palms are 
observed posteriorly two great tubercles, of which the inner is much the 
largest; there are others at the base of the 2d and 5th, and of the conjoined 
3d and 4th digits, respectively ; otherwise the palm is studded with minute 
granulations. The thumb is rudimentary, bearing a small flat nail; the other 
claws are of ordinary character; 3d longest; 4th little less; 2d shorter; 5th 
still shorter. The hairiness of the soles posteriorly is a generic character in 
comparison with Perognathus ; anteriorly they are granular, with a tubercle at 
the base of each digit, and another on the outer side of the metatarsus a little 
way up. “The small size of the hind feet, however, is one of the most obvi- 
ous distinctions from C. parvus. The longest hind foot measured in upward 
of twenty cases is only 0.70 long, or barely one-third of the length of head 
and body, while the average is much below this, and the minimum is only 
about one-fourth of the length of the head and body. We may say simply 
that the foot is usually nearer one-fourth than one-third of this dimension. 
Similarly, the shortness of the tail is a second character. In a large series, 
the vertebrae of the tail average exactly as long as the head and body; in no 
case does the tail exceed the body and head by more than 0.25 of an inch, 
and this length is only exceptionally reached. In most cases, any difference 
which may be observed is the other way, the tail being, if anything, a little 
shorter than the head and body. The tail, as in other species of this genus 
and of Perognathus (except P. penicillatus), is closely, but not very thickly, 
haired uniformly throughout ; the terminal pencil is about 0.10 of an inch long. 
The pelage is extremely fine, soft, and glossy. The pattern of coloration 
is the same as in other species of this genus and Perognathus, namely, col- 
ored above with blended light and dark tints, white below, with a clear, 
single-color stripe along the sides. The upper parts are an intimate mixture 
of pale yellowish-buff with dark brown or blackish; the hairs are clear lead- 
color basally, then buff-ringed, then (most of them) dark-tipped. The result- 
ing tone is nearly uniform over all the upper parts; but there are liable to 
appear whitish or tawny touches about the ears and eyes, and an appearance 
of a dark streak along the side of the head. The fawn-colored lateral stripe 
is uninterrupted from nose to heel; the tint is rather brighter than the buff 
