MAMMALIA—WATER RAT 231 
In some situations, these animals build houses of a conical form, re- 
sembling those of the beaver, formed of mud, grass, and reeds plastered 
together. They feed upon the roots and tender shoots of aquatic plants, and 
on the leaves of grasses. They are excellent swimmers, dive well, and can 
remain for a long time under water. Itis rare to have an opportunity of 
seeing the animal during the day, as it then lies concealed in its burrow, 
and it is not till night, that it issues forth for food or recreation. It does 
not, like the beaver, lay up a store of provision for the winter ; and it builds 
a new habitation every season. 
This animal is common in the Atlantic States, and its fur being valuable 
for hats, it is much hunted. The Indians kill them by spearing them 
through the walls of their houses. Between four and five thousand skins 
are annually imported into Great Britain from North America. 
The ondatra is of the size of a small rabbit, and of the form of a rat. Its 
head is short and similar to that of the water rat; its hair is soft and glossy, 
with a very thick down underneath, nearly like that of the beaver; its tail 
is long, and though of a different form, being flattened laterally, it is cover- 
ed nevertheless with little scales, in the same manner as those of other rats. 
LHE WATER RAT! 
Is alittle animal, about the size of the black rat. but in its nature and habits 
rather resembling the otter than the rat. Like the otter, it frequents the 
fresh waters, and is generally found on the borders of rivers, rivulets, and 
ponds ; like that creature, too, it seldom feeds but upon fish, or the spawn 
of fish, though sometimes it eats frogs, water insects, and even roots and 
herbs. This animal is not web-footed ; but, though every toe of its feet is 
separated, it swims with facility, keeps itself a long time above water, and 
carries off its prey, in order to eat it when it has reached the land. 
The head of the water rat is shorter, the nose broader, the hair more 
erect, and the tail much longer, than that of the land rat. On the back it is 
of a fine raven black ; the under part is white, with a black line along the 
middle. The body is about three incheslong. The fur has an astonishing 
power of resisting water. Like the otter, it flies from large rivers, or rather 
from those which are too much frequented, and is never found either in 
houses or in barns. 
It is probable, that these animals bring forth often in a year; but of this 
we have no certain information. Their flesh is not absolutely bad; and, in 

1 Arvicola amphibius, Lry. The genus Arvicola has two Beyer and two lower incisors ; 
six upper and six lower molars. Molars with a flat crown and angular plates of enamel 
ears large; anterior toes with nails; tail round, hairy, almost the length of the bod- 
