_Brachyurus rubicundus_, Is. Geoffr. and Dev., C. R., xxvii., p. 498
(1848); Is. Geoffr., Arch. Mus., v., p. 564, pl. 30 (1845); Castelnau,
Expéd. Amér. Sud, Mamm., p. 19, pl. 4, fig. 2 (1855); W. A. Forbes, P. Z.
S., 1880, p. 646, pls. lxi., lxii.
_Ouakaria rubicunda_, Gray, Cat. Monkeys Brit. Mus., p. 62 (1870).
_Pithecia rubicunda_, Schleg., Mus. Pays Bas, vii., p. 228 (1876).
CHARACTERS.--Face, chin, lips, forehead, and sides of face, bare (except
for a few superciliary hairs, and scant representatives of moustache and
beard), all bright vermilion red, deepening with emotion. Eyes brown; ears
square in shape, without a lobule; hair on top of head short, silky, and
grey; that on the side of the lower jaw and throat long and rich
chestnut-red, running forward as far as the symphysis, and forming
whiskers. Hair of upper surface of body entirely rich chestnut-red, more or
less black-tipped and long, especially on the shoulders and limbs; hair of
head, nape, and neck paler than on the rest of the body; tail, haired below
at tip, rich chestnut-red; under surface of body rich chestnut-red, and
less hairy. The fur in general colour and texture resembles that of the
Orang, the red hair, continued on to the limbs and tail, being particularly
long on the arms and shoulders (forming a sort of cape), and {177}along the
hind border of the thigh and leg. (_W. A. Forbes_). Between the thigh and
the lower part of the leg there is a wide expansion of the skin behind the
knee.
The thumb is in the same plane with the other digits and not opposable;
digits with compressed and rather elongated nails; the nail of the thumb
and the great-toe shorter and more "nail"-like; upper surface of the hands
and feet haired, on to the fingers. The cæcum (6 inches) and intestines (22
inches) are absolutely and relatively longer than in any other New World
Monkey.