Part 23

The Sub-family has been divided into three genera, Avahis with one species; Propithecus, with three species, and Indris with a single species. All its members are remarkable for the extraordinary amount of variation in the coloration of their fur.

{94}THE AVAHI LEMURS. GENUS AVAHIS.

Avahi, Jourdan, C. R., Journal l'Inst., ii., no. 62, p. 231 (1834).

Avahis, Milne-Edwards and Grandid., Hist. Nat. Madag., Mamm., i., p. 320 (with full synonymy).

This genus is monotypic, containing but a single species, whose characters include necessarily those of the genus.

I. THE WOOLLY AVAHI. AVAHIS LANIGER.

Lemur laniger, Gm., Syst. Nat., i., p. 44, no. 10 (1788).

Microrhynchus laniger, Jourdan, Thèse inaug. Soc. Phys., Grenoble, 1834; Mivart, P. Z. S., 1866, p. 151, pi. xv.

Avahis laniger, Milne-Edwards and Grandid., Hist. Nat. Madag., Mamm., p. 325 (with full synonymy), Atlas, pls. 9, 10.

(Plate X.)

CHARACTERS.--Fur woolly; the head nearly round; the face short in proportion to the head; muzzle short, covered with hair; the nose and region of the chin hairy; nose-pad on lip large; nostrils opening into a cavity on the upper lip below the skin. Eyes large, the pupil vertical; ears small, concealed in fur. Tail a little longer than the body; body short, stumpy. Third, fourth and fifth fingers flattened; third and fourth toes united by a membrane as far as the first joint.

PLATE X.

{95}Cranium more vaulted and the muzzle remarkably shorter than in the genera Indris and Propithecus; eye-sockets very large; the space between the eyes hollow. Temporal ridges not uniting into a single median ridge. Nasal bones projecting as far as the front end of the very small pre-maxillary bone. Lower jaw remarkably deep and broad behind; line of union of its two halves nearly half the length of the jaw, and in a straight line with the incisor teeth. Toothless space in front of upper jaw greater than in the other two genera. Dentition of the upper jaw: incisors small, the outer larger than the inner, set close to the canines and not at the inner edge of the toothless space; canines vertically short; pre-molars, with no inner cusp, but having a prominent outer cingulum (a character seen in no other species of Lemur); molars, four-cusped. Lower jaw: incisors larger than in the two other genera, and less horizontal, the inner ones more slender than the outer. Anterior and posterior molars, five-cusped. Hind margin of palate reaching to the middle of the median molar. Central bone of wrist wanting (of all Primates agreeing in this character only with Man, the Chimpanzees, the Gentle- and Sportive-Lemurs and the Endrina); fourth digit of the hands and feet longest. Tail long. The small intestine not spirally coiled upon itself, but folded many times transversely.

Hair long, woolly, dark Mouse-grey at base, reddish-brown in the middle, black at the tips. Face broad, entirely covered with short greyish-brown hairs; nose-pad alone nude. Ears concealed and covered by rufous hair; pupil of eye very contractile, very narrow and linear during the day; across the forehead and over the eyes a transverse lunulate whitish band, margined anteriorly by a black band. Back greyish-brown, the nape darker; a patch over the rump, and the base of the tail and buttocks white, washed with rufous; back and inner side of thighs and round the arms whitish; a narrow fringe on the lower margin of arms and legs ashy-grey, washed with rufous; fore-arm, hands and feet rusty-brown; tail bright dark red, deepest at its extremity. Under side and inner surface of limbs grey, washed with rufous. Length of body, 12½ inches; tail, 15¾ inches.

{96}Of this species there are two forms, an eastern and a northern, the latter being always smaller in size, with the fur lighter and less rusty. In some varieties the upper surface is dark rusty-red all over, and the inner sides of the limbs pure white. Examples from the north-west coast are constantly smaller; the head rounder, and the facial hairs grey; no white band on the forehead; upper surface bright yellowish-brown; tail rusty-grey; under side of hind-limbs pure white, the under surface and inner side of the arms whitish. The variation in coloration is due to the middle part of the hairs, which in typical specimens is rusty-red, but is yellow in the above-mentioned form. Hands and feet grey.

YOUNG.--Ashy-grey, slightly washed with red.

DISTRIBUTION.--The Woolly Avahi seems to inhabit only the forests of the parallel ranges of the mountains which face the whole eastern coast of Madagascar; it extends round the bay of Passandava on the west coast, opposite to the northern termination of this eastern range of mountains.

HABITS.--This species--the smallest of the Indrisinæ--being essentially nocturnal, is torpid during the day, and is the wildest and least docile of the family. The first specimen of the "Avahi," the name by which this animal is known among the Anatala tribe, was brought to Europe by Sonnerat, the French traveller, in 1781, and nearly half a century elapsed before a second one was obtained. Since then several specimens have been kept in captivity in the different zoological gardens of Europe.

THE SIFAKAS. GENUS PROPITHECUS.

Propithecus, Bennett, P. Z. S., 1832, p. 20; Milne-Edwards and Grandid., Hist. Nat. Madag., Mamm., i., p. 288 (with full synonymy).

{97}The characters which distinguish this genus from Avahis and Indris are the following: The fur with which they are covered is more silky than woolly, and in general appearance is white, more or less washed with yellow, varying to red or black. The head is very slightly longer than it is broad, with a black and almost naked muzzle; the ears, half buried in the fur, are flatter and wider than in Indris, the inner surface being naked and black, and the outer haired. The nostrils are large and semilunar in shape. The tail is long. The index-finger is not united by a membrane to the others; their hands and feet are in a much less degree organs of prehension than in most of the other Lemurs.

The skull in proportionate length is intermediate between that of Avahis and Indris. Compared with Avahis it is less vaulted, its muzzle is longer, and the orbits are smaller. The space between the eyes is high, and not depressed, on account of the presence of a large air-cavity in the underlying bone. Their nasal bones do not reach as far forward in front as the level of the incisor teeth. In the dentition of the upper jaw, the incisors protrude somewhat in front, and are dilated laterally in a regular series--thus distinguishing the genus Propithecus from Lemur,--the inner incisors being larger than the outer ones, with their tips approximating. Between the canine and the anterior pre-molar there is a short gap. The anterior and median molars have the cusps of the crown alternate; the posterior has them opposite. In the lower jaw the incisors are shorter and stronger than in Avahis, and the molars are four-cusped.

The genus Propithecus contains three species; (1) The Diademed Sifaka (P. diadema), (2) Verreaux's Sifaka (P. {98}verreauxi), both having numerous very marked varieties; and (3) the Crowned Sifaka (P. coronatus).

These species are found all round the coasts of Madagascar; as well in the luxuriant forests on the east side as in the arid deserts and the sparsely-wooded plains of the south-western and western coasts. Of the three species of the genus, one (P. diadema) is confined to the eastern and southern coasts, the other two (P. verreauxi and P. coronatus) are found only on the west coast. More or less distinctly coloured varieties or races of these three species occur, and it is very remarkable that each of them is rigorously restricted to localities distinct from that of the typical species.

I. THE DIADEMED SIFAKA. PROPITHECUS DIADEMA.

Propithecus diadema, Bennett, P. Z. S., 1832, p. 20; Milne-Edwards and Grandid., Hist. Nat. Madag., Mamm., p. 296 (with full synonymy), Atlas, pl. 1-3.

CHARACTERS.--Fur long, silky, the muzzle naked. Head shorter and rounder than in the other species of the genus; thumb slender, like the toes, set far back, free; great toe very strong, and in the same plane with the other digits; a marked depression exists in the skull behind the orbits. Body, 21 inches; tail, 19 inches in length.

Forehead crossed by a broad white bar; cheeks in front of the ears, and the under side of the chin, white or fulvous white; face black, with a few short black hairs. Back of head, neck, shoulders, sides of body, outer sides of arms, sometimes grey, but generally very dark brown, merging into dark grey on the lower back. Tail at its root washed with orange-yellow, paler in the middle, greyish-white at its extremity. Fore-arm, lower part of arm, sacral region, and external face of hind-limbs, bright {99}orange-yellow. Hands black-haired to the ends of the fingers, but with long and yellow tufts of hair at the tips. Feet pale orange and haired to the nails. Chest dark brown. Under surface white, or white tinged with yellow, or dark brownish-grey. Internal face of the fore-limbs grey, from the intermixture of black hairs; that of the hind-limbs pale yellow.