22 
GUIDE TO THE 
mistaken for the mouth of the animal. The use of this 
curious provision is yet unknown. This feature in the 
anatomy of the Cavy gives its name to the genus, Ccelogenys > 
which means hollow-cheeked. It will also be observed that 
the tail is only indicated by a very slight prominence. 
In its habits it is strictly nocturnal, and it is, therefore, 
usually found in its box during the day. It is also a 
burrower, constructing superficial chambers, each of which, 
it is said, has three openings, and the localities which it 
selects are, as a rule, in forests, close to water in which it 
swims and dives with facility. Its food is entirely vegetable, 
and it is very fond of sugar-cane, but it does not refuse 
animal food when in confinement. It is distributed all over 
the Eastern portion of South America, and formerly 
occurred in some of the islands of the West Indies. Its 
flesh is highly esteemed. 
The Viscacha, also a South American rodent, will be 
found in the adjoining compartment. It has somewhat the 
general characters of a hare, but with a heavier head and 
body, and a much longer, and tufted tail. It is known as 
Lagostomus trichodactylus. It is restricted to the Eastern 
slopes of the Andes, and Darwin gives the following 
account of its habits : he says that in the evening they 
come out of their holes in great numbers, and then sit 
quietly on their haunches. They are at such times very 
tame, and a man on horseback passing by, seems only 
to present an object for their grave contemplation. They 
do not wander far from their burrows. They run very 
awkwardly, and when hurrying out of danger, from their 
elevated tails and short front legs, much resemble great 
rats. Their flesh when cooked is very white and good, 
but it is seldom used. The Viscacha has one very singular 
