In the great group of the Simiadae
, which contains the
Apes and Monkeys, the attitude is sometimes habitually quadrupedal,
the axis of the body being horizontal; but, in a few
species, the trunk is habitually held in a more inclined position,
and the animals readily assume the erect attitude.
are sometimes terrestrial in habit, and good
runners, but they are always excellent climbers, and, in some
cases, they are necessitated by their organization to be almost
as thoroughly arboreal as the Sloths.
The hallux is always much shorter than the second digit
of the foot, and capable of very free movement in adduction
The series of the teeth, in each jaw, is interrupted by a
diastema in front of the canine in the upper jaw, and behind
it, in the lower; and the canine teeth are longer than the others,
the points of their crowns projecting for a greater or less
distance beyond the rest.
In the skull, the length of the basi-cranial axis equals more
than half the extreme length of the cavity which contains the
brain. The absolute capacity of the cranium is less than forty
cubic inches; and, if there is any difference in the length and
abundance of the hair which covers the body, it is longest on
the back. The uterus is undivided, and the elitoris is not
perforated by the urethra. The teats are only two in number,
and they are pectoral.
are divisible into three families-the Arctopithecini
and the Catarrhini.