Part 15

DISTRIBUTION.--Coquerel's Dwarf-Lemur, or the "Sisiba," as the natives call it, is found round Passandava Bay, near Mouroundava, on the south-west coast of Madagascar.

HABITS.--The Sisiba, like its congeners, is nocturnal and arboreal, constructing in the trees a nest of twigs. It feeds on fruits and leaves.

THE FAT-TAILED LEMURS. GENUS OPOLEMUR.

Opolemur, J. E. Gray, P. Z. S., 1872, p. 853.

The term Opolemur, by which this genus is designated, is not altogether appropriate, and is, indeed, even somewhat misleading. It was applied in the first instance to the typical species on account of the thickened base of its tail, which in the type-specimen was a very conspicuous character. The deposit of fat by which this thickening was caused was not then known to be merely transitory--a store of food collected at the base of the tail and on other parts of the body, to supply the needs of the animal during the arid and foodless season, when it retires into a state of torpidity. It is now known that {62}other species of this sub-family (as we have seen above in the case of the Mouse-Lemurs), which are generically distinct from Opolemur, share this peculiarity.

The two species included in this genus are intermediate between the Mouse-Lemurs and the Dwarf-Lemurs, and are really more nearly related to the former than to the latter. The skull is flat and depressed as in Chirogale, and the brain-case small and almost vertical behind. The posterior foramina in the palate are small. In respect to their dentition, the cusps of the upper molars are blunter and shorter than in the Mouse-Lemurs, but less so than among the Dwarf-Lemurs; the hind inner cusps of the anterior and median molars are large, and the ridge from the inner cusp is less intimately joined to the two outer cusps than in the Dwarf-Lemurs.

I. SAMAT'S FAT-TAILED LEMUR. OPOLEMUR SAMATI.

Chirogalus samatii, Grandid., Rev. et Mag. de Zool., xx., p. 49 (1868).

Opolemur milii, Gray, P. Z. S., 1872, pp. 853-4, pl. lxx., fig. i. (in part).

Opolemur samati, Forsyth Major, Nov. Zool., vol. i., p. 18 (1894).

CHARACTERS.--Head, Cat-like; hair on body and tail very short, longer at tip of tail; tail very thick at base, from accumulation of fat, especially in the month of August. Length, 7½ inches; tail, 6½.

Fur above dark grey, washed with ferruginous, the tips of the hairs silvery-grey; tail faded rufous; a white spot on the forehead, becoming a line down the centre of the nose; a black circle round the eyes; ears slightly longer; tail shorter {63}and thicker proportionately than in Chirogale milii; under surface and inner side of limbs fulvous.

DISTRIBUTION.--This species, according to M. Grandidier, to whom all our knowledge of it is due, has been obtained on the River Tsidsibon, but is reported from other places on the west coast of Madagascar.

II. THOMAS' FAT-TAILED LEMUR. OPOLEMUR THOMASI.

Opolemur thomasi, Forsyth Major, Nov. Zool., vol. i., p. 20, Taf. i., fig. 1 Taf., ii., figs. 2 and 11 (1894).

CHARACTERS.--Nearly allied to O. samati. Head broad, flat; snout short; ears short. Above grey, with a wash of rusty brown, the tips of the hair glistening silvery-grey; top of head somewhat darker; under side of tail lighter; a white band between the eyes extending down to the nose-pad, which is naked; round the neck a white ring broken by a grey spot; ring round the eyes, and hair of ears, brownish-black; cheeks, lips, chin, throat, breast, belly, inner side of limbs, upper side of hands and feet, yellowish-white, and inclining to greyish-white, where it merges into the upper side. Length, 9¼ inches; tail, 8 inches.

Skull depressed; brain-case flat and short; facial portion blunt; inter-parietal bone broad and short. Posterior upper pre-molar broader than the median, and broader than the same tooth in O. samati, the median pre-molar lacking the inner cusp. Nasal bones sharply keeled in the mid-line.

DISTRIBUTION.--Of this species only the three specimens, in the British Museum, are yet known. They were obtained near Fort Dauphin, on the south-east coast of Madagascar.

HABITS.--Nothing is known of the habits of either of these two species of Opolemur.

{64}THE TRUE LEMURS. SUB-FAMILY III. LEMURINÆ.

The third sub-family of the Lemuridæ contains the True Lemurs, which are characterised by the possession of a soft, thick, and woolly fur, the head rounded behind, with a specially elongated muzzle. They have small and oval ears, with the exterior aspect covered with long hair, but the inside naked, except round the margin. Their hind-limbs do not show so great a disproportionate length compared to that of the fore-limbs, as in the next sub-family, the Indrisinæ. The ankle-bones (tarsus) are only slightly elongated, and their toes are not united by a membrane. Their long and bushy tail is sometimes longer and sometimes shorter than the body. The females produce one or two, nearly naked, young at a birth, the mammæ being either two or four in number. The skull presents a central ridge on the frontal bone, and its facial portion is much elongated, the inter-orbital space being depressed and wider, and the orbits also directed somewhat outward and less straightforwardly than in several of the genera already noticed. The maxillary bones are generally much reduced, and the incisor teeth carried by them not unfrequently entirely aborted. The teeth in this Sub-family vary in number from 32 to 36, the dental formula being I(0-2)/2, C1/1, P3/3, M3/3. The foot is slightly elongated by the lengthening of the naviculare bone of the ankle, the others being short. In the wrist (carpus) the central bone (centrale) may be present or absent; its absence, however, is a character which is met with otherwise only in Man, the Chimpanzees, and the Endrina and some other Lemurs, to be described later on. The cæcum is not markedly developed.

{65}The external coloration of the species of this Sub-family is remarkably variable, the variation being chiefly in the upper portion of the hairs, as their base is generally slate-grey.

The sub-family Lemurinæ embraces four genera: the True Lemurs (Lemur), of which there are now eight recognised species; the Hattock (Mixocebus), with a solitary species; the Gentle-Lemurs (Hapalemur), containing two species, and the Sportive-Lemurs (Lepidolemur), with seven species. Some of the most elegantly coloured species in the Animal Kingdom belong to this group. They are gregarious, and most of them arboreal, though some are not so. They form rather an exception to the general rule among Lemurs, in not being nocturnal. They feed during the morning and evening, emitting loud cries as they move about, and during the heat of the day, they often lie stretched out in the sun; at night they rest with their long tails coiled about them. In their mode of progression they are more quadrupedal than most of the other Lemuroids; they jump, walk, or run on all fours. Their food consists of fruits, birds' eggs, birds and insects. Their infants are carried about close to, and concealed amid, the hair of their mother's breast; when older they cling to her back.

The True Lemurs are all inhabitants of Madagascar and of the adjacent Comoro Islands. They are unknown on the African continent.

THE TRUE LEMURS. GENUS LEMUR.

Prosimia, Brisson, Regn. Anim., p. 220 (1756).

Lemur, Linn., Syst. Nat., i., p. 44 (1766).

Varecia, Gray, P. Z. S., 1863, p. 135.