556 
In the case of this species it is probably always easier, by thor- 
ough tillage, to prevent its becoming a pest than to destroy it after it 
has become abundant. 
MOLE MEADOW-MOUSE; MOLE-LIKE VOLE. 
Mucrotus pinetorum scalopsoides (Audubon and Bachman). 
Arvicola scalopsoides Aud. and Bachm., Proc. Acad. Nat. Sci. Phil., I., 1841, p. 97. 
I have never identified an individual of this species among our 
specimens, and I doubt if it is found in this county. Kennicott 
reports it as common in the northern part of the state. He says 
that it is readily distinguished from the other meadow-mice “by 
its smaller size, glossy fur, large muzzle, 
ONOYGy7@e small eyes, and very short tally = slam 
technical works the distinction is based 
on the number of mamme and the form 
ARAMAM ODD of the teeth. The miaimmnics sinmauaee 
species are four in number, while there 
bh edo ee °F Care eight in the otherspecies Onl tammmaae 
found in the state. In this species (Fig. 
3), the enamel pattern of the third molar forms two triangles, while 
in the other species it forms three (Fig. 1 and 2). 
This meadow-mouse inhabits woods rather than open fields, and 
was called the wood meadow-mouse by Kennicott. Otherwise, so far 
as known, its habits are in general similar to those of the other 
meadow-mice. 
MUSKRAT; MUSQUASH. 
Fiber zibethicus (Linneeus). 
Castor zibethicus Linn., Syst. Nat., I., 1766, p. 79. 
The muskrat, under several subspecies, is found generally through- 
out North America from northern Mexico to Hudson Bay. The 
range of the typical form which is found in Illinois is given by Elliot 
as “‘Labrador to the Gulf States, excepting possibly the Dismal 
Swamp, Virginia, and from the Atlantic Coast to the Rocky Moun- 
tains north of the Gulf States and Arizona, and south of Keewatin, 
Canada.” 
