MAMMALS OF MINNESOTA. PAM 
. in size from the middle to the apex. The vibrissz are unusu- 
ally fine and long, reaching beyond the apex of the ear, and 
are of uncertain color, really black, but so polished as to appear 
partly white. The sole is very densely covered with fine close 
hairs,and there are but four tubercles. The ears vary in length, 
but seem to be intermediate between the varieties above men- 
tioned. 
O. pallidus burrows on the sandy prairies and seems to be 
largely diurnal in habit. We know little regarding its habits, 
but, inasmuch as its stomach was found filled with the remains 
of grass-hoppers and other insects, we are justified in claiming 
that the suggestion of a largely insectivorous diet offered by 
the dentition is borne out by actual observation. 
The coloration must be influenced by the constant exposure 
which a chase of diurnal insects makes’ necessary upon the 
open plains; and the short and nearly naked tail are suggestive 
of the fossorial habits. 
The following table gives all the details at command con- 
cerning the proportions; and as all the measurements were 
made with great care upon recently killed specimens, may be 
trusted as thoroughly reliable.* 
ENP 
No. Nose Tail Nose Nose Hind Fore Ear. cece 
to anus. to ear. | toeye. foot. foot. 

0.60 0.90 0.55 | 0.60 female. 


103 4.60 1.45 1.08 
104 4.40 1.35 1.00 0.55 ae Vine en .| 0.50-++| male. 
105 3.95 1.50 1.00 050 | 0.80 Qa) Wes. wee .| male. 
114 4.15 1.60 0.92 EA COURS Parca Get ses sce male. 
115 5.10 1.60 1.20 0.60 0 90 to) 1S ee ape -| “apale. .. 

GENUS FIBER, CUVIER. 
Fiber zibethicus (L.) Cuv. 
MUSKRAT. 
Figs. 12 and 13. 
The muskrat is the largest of the mice and is typically arvi- 
coline, differing chiefly in those modifications correlated with 
its aquatic habits. 
The dentition is moderately individualized. The upper in- 
cisors are semicircular with plane outer surface. The first 

*It should be said that Dr. Merriam. who has examined the types of this species in 
the National Museum, considers the present variety identical with the type. In 
this case the published descriptions obviously require revision. 
