1 36 Auvioolid^e. MAMMALIA. Arvicoi.id.e. 
Family V.— ARVICOLIDiE. 
The Swimming Ar\dcoles or Voles are distinguished 
from the true mice chiefly by the cliaracter of tlie teeth. 
The incisors are large, chisel-shaped, and coloured 
deep yellow in front ; the molars have flat crowns pre- 
senting enamelled folds, in the form of alternating 
triangles, on either side. The fore-feet are tetradac- 
tyloiis, with a rudimentary thumb. The muzzle is 
obtuse, and the ears are not large. The tail is rather 
short, rounded, and hairy. 
THE WATER RAT {Arvicola amphihia) has a very 
close, thick, and shining fur of a rich reddish-brown 
colour, -which becomes paler inferiorly (flg. 46). Its 
habits are almost too well luiown to require des- 
cription. Frequenting the banks of almost every stream, 
canal, or dyke in this country, it constructs its bur- 
rows upwards from the water’s edge. “ It dives 
Fig. 46. 
The -Water Hat (Arvicola amphibia). 
and swims with great facility, instantly seeking the 
water upon every alarm, and plunging at once to the 
bottom ; from whence, howevei’, it is obliged to return 
to the surface for respiration about every minute. It 
has often been asserted that the water vole lives upon 
small fish, earthworms, and insects, and it has even been 
accused of destroying jmung ducks. There is not, how- 
ever,” observ^es Mr. Bell, “ the slightest foimdation for 
this opinion.” It feeds on roots and various aquatic 
plants. The female produces live or si.\ yoiuig at a 
single birth. 
THE FIELD VOLE {Arvicola ar/restis), or Meadow 
Mouse, is about four inches in length, exclusive of the 
tail, which measures rather more than an inch. Its 
habits are extremely destructive. It feeds on various 
vegetable matters, grain, &c., and is particularly fond of 
carrots. It is very prolific, the female producing from 
five to seven young at a birth. The best method of 
destroying these pests is by entrapping them in holes 
excavated in the ground ; these pits should be wider 
below than above. 
THE BANK VOLE {Arvicola riparia) is, in common 
with the foregoing, a native of Europe. It is three 
inches and a quarter long, and the fur is of a bright 
chestnut red above and greyish beneath. The tail is 
about half the length of the body. It is not very 
abundant in Britain, and but little is known respecting 
its habits. 
THE YELLOW-CHEEKED VOLE {Arvicola xantho- 
gnatlms) is an American species, and is abundant in the 
neighbourhood of Fort Franklin, and also among the 
Rocky Mountains, especially in localities where the 
woods have been destroyed by fire. Its habits are 
similar to those of the common water rat. Length of 
the body is from five to eight inches. The females 
produce seven young at a birth. 
WILSON’S VOLE {Arvicola Pennsylvanicm) is, ac- 
cording to Sir John Richardson, very abundant from 
Canada to Great Bear Lake. It infests barns and 
storehouses, where it hoards up grain and seeds of 
various kinds ; it is said also to be very partial to the 
bulbs of the Philadelphia lily. The body is about 
three and a half inches long, the fur behig brownish 
and white underneath. 
RICHARDSON’S VOLE {Arvicola borealis), or Nor- 
thern Meadow Mouse, is about four and a half mches 
long, exclusive of the short tail, which measures only 
an inch. Its habits are simOar to those of the YeUow- 
Cheeked species. It is found in abundance on the 
borders of the Great Bear Lake. The fur has a chest- 
nut tinge mixed with black ; under the belly it is greyish. 
THE SCANDINAVIAN LEMMING {Ahjodes Lemmus) 
is about the size of an ordinary rat. The fur is of a 
ruddy yellow colour, variegated with black. Its proper 
residence is among the mountains of Norway and 
Sweden, but it has a remarkable propensity to emi- 
grate at certain periods. Van der Hoeven remarks, that 
on these occasions multitudes of them “ eat everythhig 
bare on the road, like locusts. This usually forbodes 
a hard winter. The number of these animals thus 
suddenly appearing in situations where they were pre- 
viously unknown, gave occasion in former times to the 
strange opinion that they descended from the clouds.” 
It is sometimes called on this account the Northern 
Mouse op Passage. 
THE GREENLAND LEMMING {Myodes Greenlandi- 
cus) — Plate 15, fig. 49 — was first described by Lr. 
Traill, from a specimen procured by the distinguished 
navigator. Captain Scoresby. The body is six and a 
quarter inches in length, the tail measuring only three- 
quarters of an inch. There are no external ears. The 
fore-feet are hairy beneath, the digital claws being- 
rounded and sharply pointed. The central line of the 
back is marked by a dark band. The muzzle terminates 
in a sharp nose. The eyes are near each other, and 
comparatively small. 
THE HUDSON’S BAY LEMMING {Myodes Hudsonius) 
is scarcely so large as the i)receding, and, according to 
Richardson, is distinguished by the two central claws 
of the fore-feet being unusually large ; they are like- 
wise compressed, “ their very blunt extremity being- 
rendered double by a deep transverse notch.” Although 
this species is very easily tamed, very little is known 
respecting its habits. 
BACK’S LEMMING {Myodes trimucronatus) inha- 
bits the wooded districts of North America, and is 
named after Captain Back, who first discovered it on 
the banks of Point Lake. Sir John Richardson states. 
