256 
EXPLORATION OF THE CANONS OF THE COLORADO. 
the extreme of this race as above described, characterized by the purity, of 
the gray and brown shades, absence of any decided reddish cast, and pure- 
white feet, tail, and throat. Specimens from Selkirk Settlement and the 
Assiniboine region are identical. Others, from Idaho, Nevada, and Utah, arc 
too nearly similar to admit of any intelligible noting of differences;' though, 
as might be expected, there is a slight tendency to the characters of bulbi- 
vorus. 
A few specimens before me from Southern and Western Dakota, being 
those that Baird referred to " rufescens," with one from California, which he 
placed under "borealis," and one lately received from Fort Benton, Montana, 
are more decidedly reddish-brown than any of the above. They are unques 
tionably exactly what Maximilian called "rufescens." They are all consider 
ably smaller than average talpoides ; and, if I could satisfy myself that they 
were full-grown, something more would have to be said upon the subject. As 
it is, however, I can make out no satisfactory distinctions from ordinary 
talpoides. There are only five or six of these small rufous specimens before 
me ; fuller series may indicate some tangible distinctions. 
The following measurements indicate the average dimensions, and, to 
some extent, the variation, of this species : 
Current number. 
Locality. 
Sex. 
From tip of nose to 
Tail to end of ver 
tebrae. 
Length of 
Lougest fore claw. 
Nature of 
specimen. 
6 
>> 
W 
ti 
a 
W 
Occiput. 
'rt 
H 
u 
O 

o 
t-l 
o 
Pn 
Ip 
O 
1 
f v3 
i 
11515 
11517 
11518 
11520 
11522 
Souris River, Dakota 
Peinbiua, Dakota . . 
X 
9 
$ 
$' 
$ 
1.00 
0. 75 
0.90 
0.90 
0.95 
l.GO 
1.40 
l.GO 
1.50 
l.CO 
1.75 
1.60 
1.70 
1.90 
1.80 
7.00 
6.25 
7.50 
7.25 
7.00 
2.50 
2.75 
2.50 
2.75 
2.60 
1.25 
1.15 
1.20 
1.25 
1.25 
1.25 
1.25 
1.20 
1.20 
1.20 
0.55 
0.55 
0. 50 
0.45 
0.55 
Fresh. 
Fresh. 
Fresh. 
Fresh. 
Fresh. 
Pembina. Dakota . 
Pe uibina, Dakota. 
Pembina, Dakota . 
NOTE. The foregoiug specimens, all adult, taken the same season ( Juue to September, 1873), were 
carefully measured in the flesh by myself. Other specimens, from the same region, not measured in the 
flesh, carry the limits of total length from about 6 to a.bout 8 inches, with a corresponding range of vari 
ation in other parts. The tail is taken from its true base it appears about half an inch shorter in the 
dried state. The weight of these specimens ranges from 6 to 7 ounces. The girth of the chest is about 
5 inches ; of the belly, 6.50. No. 11517, 9 , has 12 teats 2 pairs axillary, 2 pairs pectoral, 2 pairs inguinal 
When fully distended, m the fresh state, the width across the check-pouches is the greatest diameter of 
the body. 
