26 
U. S. P. R. R. EXP. AND SURVEYS-ZOOLOGY-GENERAL REPORT. 
white, with a slight tinge of brown ; the color well contrasted against the hack. The feet and 
under surface of the tail are whitish ; the upper surface of the tail like the hack ; the entire 
tip dusky. The teeth are light chestnut at the point. 
The upper premolar teeth are imbricated anteriorly, and diminish from the first to the fourth 
w-ith considerable regularity ; the difference between the third and second being much less 
appreciable than in S. cooperi. 
The weight of a specimen of this species, as given by Linsley, is 47 grains ; that of number 
1696, however, of the accompanying table, amounted only to 37 grains. 
For the measurements of the skull of this species, see the table under the head of S. cooperi. 
There are some slight variations from the above characteristics in different specimens. Thus, 
the tail is sometimes a little longer or shorter. The ear varies somewhat in size. Sometimes 
the chestnut of the hack is of a browner or darker shade—a characteristic, probably, of the 
winter pelage. In immature specimens, the tail is almost naked, and the tips of the teeth with 
little or no color, even when of full size. 
This species is perhaps more nearly related to S. forsteri than to S. cooperi , although resem¬ 
bling the latter most in color. In size it occupies an intermediate position, as also in the pro¬ 
portional length of the tail. 
Its distribution I have not yet ascertained with precision, though it is known to range from 
eastern Massachusetts to Cleveland, Ohio, and as far north as Burlington, Vermont. 
List of specimens and measurements. 
Current 
number. 
Locality. 
Sex. 
Nose to— 
Tail to end of— 
Length of— 
Ear. 
Nature of 
specimen. 
From whom re¬ 
ceived. 
Occip. 
Tail. 
Verteb. 
Hairs. 
Fore ft. 
Hind ft. 
1691 
Hingham, Mass. _ 
82 
2.10 
1. 50 
1. 65 
25 
45 
25 
In alcohol. 
Dr. T. M. Brewer. 
1693 
Middleboro,Mass. 
_ 
85 
2.15 
1. 46 
1. 65 
25 
47 
25 
-do_ 
J. W. P. Jenks--- 
April & May. 
1694 
85 
2. 04 
1. 50 
1. 60 
25 
46 
25 
_do_ 
1695 
85 
2. 25 
1. 40 
1. 50 
25 
46 
25 
? 1696 
October_ 
81 
2. 00 
i. 62 
1. 85 
25 
46 
25 
1697 
80 
2.10 
1. 46 
25 
46 
_do 
_do_ 
1698 
Spring_ 
85 
2,19 
1. 55 
1. 65 
25 
46 
25 
.do_ 
1699 
_do.-.... 
s 
85 
2.18 
1. 46 
1. 55 
25 
46 
25 
_do.. . 
.do. 
1700 
85 
2. 00 
1. 60 
1. 60 
25 
46 
dn 
_do.------- 
1701 
_do_ 
90 
2.10 
1. 45 
1. 55 
25 
45 
? 1702 
December_ 
85 
2. 00 
1. 60 
1. 80 
25 
46 
1703 
.... 
85 
2.18 
1. 45 
1. 60 
25 
46 
1704 
_do..... 
80? 
2. 15 
1. 50 
1. 62 
25 
46 
1705 
80 
1. 90 
1. 49 
1. 55 
25 
45 
do ... 
1706 
85 
2. 10 
1. 50 
1. 62 
24 
45 
954 
Nov. 1, 1855_ 
* 
1084 
Dec. 12, 1855... 
955 
Oct. 29, 1855 ... 
J.436 
Mar. 28, 1856... 
84 
1. 50 
1. 58 
45 
814 
Cleveland, Ohio.. 
I 2. 25 
Dr. Kirtland_ 
■fih 
Burlington, Vt.. 
. 
Prof. Thompson.. 
