_Hapale_, Illiger, Prodr. Syst. Mamm., p. 71 (1811).
The members of this genus, which are often kept in captivity as pets, are
very small animals, covered with thick and silky fur, and having bushy
tails, equal to or even exceeding the length of their body. The head is
round, the eyes large and watchful, the face short and nude, and often
abundantly whiskered. The mouth is large; the ears also large and often
fringed, and the neck sometimes clothed, with long hair. They are
distinguished from the Tamarins (_Midas_) by having their upper incisor
teeth long, narrow, and protruding outwards and forwards; the incisors of
the lower jaw are also very long, and its canines small and shorter than
the incisors, both being protrusive, as among the Lemurs. The cranial
region of the smooth skull is conspicuously large in comparison with its
facial portion, but the cerebrum shows a low type of organisation, and
indicates a small degree of intelligence in its possessor; it is smooth and
almost devoid of convolutions; the cerebrum, too, unlike that of the
_Lemuroidea_, completely covers the cerebellum. The orbits are large, and
almost completely walled in from the temporal depression behind. The
stomach in form resembles that found in the higher groups, but its orifices
for the entrance and exit of food are nearer to each other than in any of
the other American Monkeys.
The female produces two or three young at a birth, instead of one, as is
the general rule among the _Anthropoidea_. The species vary much in
coloration, and some of them resemble the Lemurs in being ring-tailed.
{132}The Marmosets are all gentle and playful in disposition, and are, on
this account, very largely brought to Europe as pets; but they are very
delicate, and rarely survive long in confinement after the advent of the
Northern winter. They are arboreal, living in troops, and feeding on
insects and fruit, and not disdaining flesh, especially of fishes, when
they can obtain it. They emit a characteristic chirping noise.