Part 40

Cæcum with dilated end; liver more divided than in C. moloch; the two halves (rami) of the lower jaw enormously deep, resembling those of the Howlers (Mycetes).

DISTRIBUTION.--Brazil; Bahia, and the country between the Parahyba and the mountains to the north of the Bay of Rio de Janeiro.

HABITS.--This species is very rare, and nothing is known of its habits.

Professor Weldon writes, in his paper in the "Proceedings of the Zoological Society," referred to above: "Sir W. Flower has suggested to me that the enormous depth of the ramus of the mandibles in this Callithrix pointed to the existence of some arrangement resembling that of Mycetes. It was difficult to determine this point in a young female; but the swollen condition of the thyroid, together with the existence of a patch of ossification on each side, seem to show the possible existence of a howling apparatus in the male."

THE DOUROUCOLIS. GENUS NYCTIPITHECUS.

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.

II. THE LEMURINE DOUROUCOLI. NYCTIPITHECUS LEMURINUS.

Nyctipithecus lemurinus, Is. Geoffr., Arch. Mus., iv., p. 24, pl. 21 (1844); Gray, Cat. Monkeys Brit. Mus., p. 58 (1870).

{169}Nyctipithecus felinus, Gray, List Mamm. Brit. Mus., p. 14 (1843); Schl., Mus. Pays Bas, vii., 214 (1876).

CHARACTERS.--Fur of body and head long; tail depressed, broad, with the hair bushy and spreading on the sides as in a Squirrel. Head presenting a dark frontal area with a round white spot over each eye.

DISTRIBUTION.--The Lemurine Douroucolis are found in Colombia and in Upper Amazonia; at Macas, on the eastern side of the Andes; and on the upper branches of the main streams of the Amazon, as far as a congenial habitat is met with.

III. THE RED-FOOTED DOUROUCOLI. NYCTIPITHECUS RUFIPES.

Nyctipithecus rufipes, Sclater, P. Z. S., 1872, p. 3, pl. 1.

Nyctipithecus vociferans, Spix, Sim. et Vespert. Bras., p. 25, pl. 19 (1823; part); Schl., Mus. Pays Bas, vii., p. 214 (1876; part).

(Plate XV.)

CHARACTERS.--Above grey, slightly washed on the back with rufous; under side reddish fulvous; three vertical black stripes on the head, similar to N. trivirgatus, but much less distinct, narrower, and showing a prominent triangular white patch over each eye; ears large and prominent, almost nude (perhaps the result of captivity). Hands and feet rufous; tail short-haired, cylindrical; the basal half rufous, the remainder reddish-black. Length of the body, 11 inches; and of the tail, 16 inches. The absence of the long chestnut patch on the back distinguishes N. rufipes from N. trivirgatus, and its paler colour and the indistinctness of its head-stripes, separate it from N. felinus.

DISTRIBUTION.--Nicaragua; San Juan del Norte.

{170}IV. AZARA'S DOUROUCOLI. NYCTIPITHECUS AZARÆ.

Simia azaræ, Humb., Obs. Zool., p. 359 (1811).