_Nyctipithecus_, Spix, Sim. et Vespert. Bras., p. 24 (1823).
The members of this genus, usually called "Douroucolis," are small animals,
somewhat Lemurine in appearance, possessing a short, thick body, a rounded
head produced behind, and a short, round face, encircled by a ruff of
whitish fur. The muzzle is not prominent; the mouth and chin are small; the
{167}ears are very short, scarcely appearing above the hair of the head;
the eyes are enormous and yellowish in colour, imparting to them the
staring expression of nocturnal animals of prey. Their tail is bushy,
moderately long and non-prehensile; and the nostrils are separated by a
narrower partition than in the other genera of the sub-family. Their
physiognomy reminds one of an Owl or Tiger-cat (_Bates_). They are covered
with close, soft, woolly fur.
In the skull the orbits are enormously large and closely approximated, but
yet separated by a complete bony wall; the nostrils, on the other hand,
though separated in the living animal by a wide, fleshy partition, have
only a thin plate of bone between them. The upper incisors are broad; the
canines long; and the lower incisors project forwards, somewhat as in the
Lemurs. The arm-bone has a perforation (the ent-epicondylar foramen) on its
inner side above the articulation of the elbow joint, to give passage and
protection to an important artery and nerve. The thumb is very short; the
claws are small and weak. The dorsal and lumbar vertebræ together number
twenty-two, the greatest number possessed by any American monkey. As in
_Chrysothrix_, the external surface of the cerebral hemispheres is smooth
and almost devoid of convolutions, but their inner faces exhibit several of
the more important grooves seen in the higher Apes.
All the species are arboreal and nocturnal, hiding away in the daytime and
roaming during the night, giving vent to loud howls, or Cat-like cries, as
they move in quest of the insects, small birds, and fruits, which form
their food. They range from Nicaragua to the Amazon and Eastern Peru, and
are called "Devil monkeys" by the Indians. They are very delicate, and soon
die in captivity.
{168}I. THE THREE-BANDED DOUROUCOLI. NYCTIPITHECUS TRIVIRGATUS.
_Aotus trivirgatus_, Humboldt, Obs. Zool., p. 306, fig. 28 (1811).
_Nyctipithecus trivirgatus_, Gray, Ann. Nat. Hist., x., p. 256 (1842);
id., Cat. Monkeys Brit. Mus., p. 58 (1870); Schl., Mus. Pays Bas, vii.,
p. 213 (1876).
CHARACTERS.--Fur short, grey and brown, with a silvery lustre; on the crown
of the head three long black linear streaks, distinct from each other;
frontal spot whitish; back greyish-brown with a dark dorsal band and a long
chestnut patch; chest and lower surface of body rusty-red; throat, and
inside of limbs, greyish-ashy; tail long, cylindrical, and with short,
blackish-brown hair, more yellow on the under surface of the base. Length
of the body, 12 inches; of the tail, 14 inches.
DISTRIBUTION.--The type specimen was obtained by Humboldt on the banks of
the Cassiquiare, near the head waters of the Rio Negro. Mr. Bates found it
at Ega and at other places on the Upper Amazon region. It has been recorded
also from Guiana; and from Chanchamayo in Peru, at 3,000 feet above the
sea.
HABITS.--The habits of the Three-banded Douroucoli are entirely nocturnal.
They hide in small troops in a hole in the trunk of a tree from morning
till twilight, hunting for food during the night. They have a singularly
loud and far-reaching voice for such small animals.