same time their bark. After diving a short distance they
came again to the surface, but only just showed the upper
part of their heads. When the female is swimming in the
water, and has young ones, they are said to sit on her back.
These animals are easily killed in numbers; but their skins
are of trifling value, and the meat is very indifferent. On
the islands in the Rio Parana they are exceedingly abundant,
and afford the ordinary prey to the Jaguar.

The Tucutuco (Ctenomys Brasiliensis) is a curious small
animal, which may be briefly described as a Gnawer, with
the habits of a mole. It is extremely numerous in some
parts of the country, but it is difficult to be procured, and
never, I believe, comes out of the ground. It throws up at
the mouth of its burrows hillocks of earth like those of the
mole, but smaller. Considerable tracts of country are so
completely undermined by these animals, that horses in passing
over, sink above their fetlocks. The tucutucos appear,
to a certain degree, to be gregarious: the man who procured
the specimens for me had caught six together, and he
said this was a common occurrence. They are nocturnal in
their habits; and their principal food is the roots of plants,
which are the object of their extensive and superficial burrows.
This animal is universally known by a very peculiar
noise which it makes when beneath the ground. A person,
the first time he hears it, is much surprised; for it is not
easy to tell whence it comes, nor is it possible to guess what
kind of creature utters it. The noise consists in a short, but
not rough, nasal grunt, which is monotonously repeated
about four times in quick succession: [6] the name Tucutuco is