16 
U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY-GENERAL REPORT. 
and scantily clothed with short stiff depressed hairs, which constitute a very small pencil at the 
end. The fur is very long and full, measuring three lines on the hack. 
The upper parts are of a rather dark olive brown, with a hoary tinge, caused by penultimate 
bars of grayish on the hairs. The sides are paler, with a tinge of chestnut ; the under parts 
are of a yellow brownish white. The feet and under surface of the tail- are white, with a dusky 
yellowish tinge. 
The skull is moderately slender anteriorly. The dentition is |-+ ^|== 32. The 
upper anterior incisor has a second hook at the base, decidedly smaller, however, than the one 
in front of it forming the tip of the tooth and about equal to the third lateral tooth. The 
first two lateral teeth are of equal size, and decidedly larger than the fourth, which, however, 
is larger than the third. The teeth are all chestnut colored at the tips. 
Measurements of 630 {first four taken before skinning). 
Inches. 
Lines. 
Nose to occiput__ 
Nose to root of tail_ 2 
Tail to end of vertebrae_«.—-- 1 
Tail to end of hairs.-... 1 
Hand from wrist.......... 
Foot from heel__ 
Skull, length.... 
Skull, width.... 
Length of palate......... 
Width of upper jaw.. 
9 
0 
8 
8* 
H 
k 
»A 
3-nr 
2 * 
Several specimens in alcohol agree essentially with the preceding description taken from a 
dried skin. In one or two the color of the hack is a brighter chestnut than as described. 
There is considerable difference in the thickness of the tails at the base, and the swelling of the 
head ; these, however, are probably sexual characters, as they are most marked in the males. 
In most specimens, the terminal pencil of hairs of the tail is worn off to a stump, or else want¬ 
ing, leaving the tip of the tail naked. In 1259 this pencil is, however, visible. 
Measurements from alcoholic specimens. 
1675. 
1261. 
1259. 
Length, of head__ , „__ 
0. 87 
0.86 
0. 87 
Head and body_____ 
2.21 
2.55 
2.26 
Tail to en d of vertebral____ 
1. 67 
l v 15+ 
1.15+ 
0. 28 
1. 75 
Tail to end of hairs _ __ _ _ 
L 67 
1. 85 
Fore foot _-__ 
0. 29 
0. 28 
Hind foot ___ 
0. 50 
0. 49 
0. 49 
Far ____ 
0. 25 
0. 26 
0. 25 
