290 ZOOLOGICAL GARDENS. 
Menagerie about five and twenty years ago. Daubenton 
had before remarked that the zygomatic arches of the 
Paca were very large, and descended more than usually 
low; and Buffon had noticed that “ on each side and 
towards the lower part of the upper jaw there exists a 
sort of longitudinal fold, destitute of hair in the middle, 
so that at first sight it might be mistaken for the mouth 
of the animal.” Had this distinguished zoologist pro- 
ceeded further with his examination, he would have 
discovered that the fold of which he speaks forms the 
opening of a shut sac of considerable extent, passing 
upwards behind the arch formed by the union of the 
bones of the cheek and temple, the inner surface of this 
portion of those bones being lined by a continuation of 
the skin of the face, which is afterwards reflected upon 
the upper lip. No use has yet been assigned for this 
curious provision, but a somewhat analogous structure 
occurs in the Gauftres of North America, forming the 
genus Diplostoma of Rafinesque. It bears no analogy 
to the cheek-pouches of the monkeys, for its opening 
is external to the mouth, which is moreover furnished 
with true cheek-pouches, capable of considerable dila- 
tation, and occupying when filled the entire space 
beneath the zygomatic arches. 
The Pacas are animals of a thick-set and clumsy 
form, measuring when full grown about two feet im 
length from the tip of the nose to the extremity of the 
body, and about one foot im height both before and 
behind ; for although the hinder legs are considerably 
longer than the anterior, they are so bent as to allow a 
much greater proportion of their length to press upon 
the surface of the ground. Their eyes are large, pro- 
minent, and of a brownish hue; the tips of their noses 
broad and blackish; their ears nearly naked ; and their 
whiskers long and rigid. We are indebted to M. Fre- 
