Handbook to the Primates/Galaginae
THE GALAGOS. SUB-FAMILY II. GALAGINÆ.
The Lemurs comprised in the present Sub-family are divisible into two groups—those inhabiting the mainland of Africa and those confined to the island of Madagascar. The exclusively African species, the True Galagos, constitute the single genus Galago; while the Malagasy group is represented by three genera, the so-called Fat-tailed Lemurs (Opolemur), the Dwarf-Lemurs (Microcebus), and the Mouse-Lemurs (Chirogale). The members of this Sub-family vary considerably in size, and are all covered with soft woolly fur. Their ears especially are largely developed, being more or less membranaceous and naked, and their sense of hearing very acute. The eyes are large and the tail always elongated. In the skull the length of the muzzle is less that the greatest longitudinal diameter of the orbit (except in the genus Galago). Their teeth number 36—18 above and 18 below—as in the bulk of the Lemuridæ; the upper molars present on their crown an oblique ridge from the outer hind cusp to the inner front cusp. The ankle region (tarsus) of the hind-limb is much elongated, through the lengthening of two of its bones (the calcaneum and naviculare): this feature occurring to a greater extent among the African than among the Malagasy species. The mammæ are four in number, two on the breast and two on the abdomen.
Many of the species hibernate during the dry winter season, and to enable them to survive, they accumulate during the summer months a thick deposit of fat over their bodies, more especially at the root of the tail, a fact first conspicuously observed in the Opolemurids. This fat is absorbed for their sustenance during their prolonged torpidity.
THE AFRICAN GALAGOS. GENUS GALAGO.
Galago, Geoffr., Mag. Encycl., Ann. 2, i., p. 49 (1796).
The African Galagos are generally larger in size than the Madagascar members of the group, and have the snout produced beyond the lower jaw. Their ears are large, membranaceous, and have a very mobile contractile hinder edge, the animal having the power of folding them up at will. The eyes are also large and approximated; the fingers and toes very long and slender, and the tail thick and bushy.
The skull presents a high, broad, and round brain-case, with a relatively short facial region. The pre-maxillary bones are very much reduced, so that the muzzle, measured from the anterior margin of the orbit forward, is shorter than the longitudinal diameter of the orbits. The bony palate is also relatively short. Compared with those of the Madagascar generathe orbits are, according to Dr. Forsyth Major, much broader vertically and horizontally in the genus Galago. The squamosal region of the skull and the outer portion of the ear-capsules (the periotic) are large and inflated. The mandible (or lower jaw) has its lower hind edge, or angle, produced backward.
The dentition of the Galagos presents several important characters. In respect to their upper teeth, the incisors are small, equal, and have a hind cusp on the cingulum. A distinct gap exists between the canine and the pre-molar teeth. Of the pre-molars, the anterior one is canine-like, and is equally distant from the canine and its own next neighbour. To the outside it has one main cusp, and generally one minute supplementary cusp on each side. The median pre-molar shows three cusps, and one strong inner front cusp. The posterior pre-molar is always molar-like. It has one front supplementary and two main cusps to the outside; and one front and one supplementary hind cusp to the inside: it has also on the crown the oblique ridge spoken of above.
The molars have a deep concavity on their hind border, due to the development of the cingulum on the inner half only of that border of the tooth; to the outside they present two main cusps (and often supplementary minute fore and hind cusps); while to the inside they present two cusps, and also an intermediate cusp in front between the two fore cusps; the oblique ridge is also here present; the hindmost molar is three-cusped. The five hind molars are, therefore, nearly equal in size. In the lower jaw the pre-molars are complicated. The anterior and median are canine-like and procumbent, with a cusped heel behind; the posterior is distinguished from a molar only by the lesser size of its fore-part. The molars are also complicated; the anterior and median are equal in sizeand four-cusped—the two front cusps (united by a ridge) are taller than the two hind ones, and there is a minute cusp between the two hind cusps. The posterior molar, though smaller than the others, is five-cusped. The oblique ridge is not present in the lower molars.
The brain of the Galagos is narrower and shallower than that in the Lemurinæ.
The female gives birth to two or three young at a time.
According to Dr. Forsyth Major, who has made the Lemuroidea a special study, the smaller African Galagos have departed less from the primitive Lemuroid type than the Madagascar genera, in which greater specialisation has taken place.
The members of the genus Galago are widely distributed on the African continent, but are unknown in Madagascar. They range throughout the dense forest regions, from Abyssinia in the north-east, to Senegambia in the west, and southward as far as Natal and Mozambique.
Almost all the Galagos are nocturnal. They are chiefly arboreal, and when they descend to the ground they advance by hops on their long hind-limbs. They feed chiefly on fruits, insects, birds, and birds' eggs.
I. GARNETT'S GALAGO. GALAGO GARNETTI.
Otolicnus garnettii, Ogilby, P. Z. S., 1838, p. 6.
Otolemur agisymbianus, Coquerel, Rev. et Mag. de Zool., 1859, p. 457.
Otogale garnettii, J. E. Gray, P. Z. S., 1863, p. 140.
Galago garnettii, Sclater, P. Z. S., 1864, p. 711, pl. xi. Schlegel, Mus. Pays Bas, vii., p. 429 (1876).
Characters.—Head round; snout elongate, protruding overthe lower jaw; ears very long, wide and rounded; eyes large and approximated. Toes and fingers not united by a membrane. Posterior upper molar with its fourth cusp little developed; the posterior lower molar four-cusped.
Fur woolly, the basal part of the hair Mouse-grey, the tips dull yellowish-white. Ears greyish-black; face from the middle of crown along the nose and round the eyes greyish-white. Top of head and neck dark pepper-grey; rest of upper side yellowish-grey, with longer black hairs distributed over the body; outside of arms and legs washed faintly with faded rufous. Under side and inner side of arms and legs greyish-white. Tail brownish-red at base, darker at tip. Length, 8 inches; tail, 8¾ inches.
Distribution.—East coast of Africa.
Habits.—Garnett's Galago is essentially nocturnal in its habits, feeding on fruits. According to Mr. Bartlett, it exhibited in confinement no fear of Cats or Dogs, and was very sprightly and tricky. It kills all it can pounce upon and overpower. On the ground it jumps upright, like a Kangaroo, on its hind-limbs, without using its fore feet, covering several feet at a spring.
II. THE SENEGAL GALAGO. GALAGO SENEGALENSIS.
Galago du Sénégal, Geoffr., Mag. Encycl. Ann. 4e, p. 1 (1796).
Galago senegalensis, Geoffr., Ann. Mus., xix., p. 166 (1812); Is. Geoffr., Cat. Méth. Primates, p. 81 (1851); Schlegel, Mus. Pays Bas, vii., p. 329 (1876).
Galagoides senegalensis, Smith, S. Afr. Q. Journ., ii., pt. 1, p. 32 (1833).
Galago moholi, Smith, Ill. Zool. S. Afr. Mamm., pls. 8, 8 bis (1839); Gray, P. Z. S., 1863, p. 147.
Otolicnus galago, Wagner in Schreber's Säug. Suppl., i., p. 292 (1840); Van der Hoeven, Tijdschr. Nat. Ges., xi., p. 41 (1844).
Otolicnus senegalensis, Peters, Reis Mozamb. Säug., p. 11 (1852).
Galago senaariensis, J. E. Gray, P. Z. S., 1863, p. 147, Mivart, P. Z. S., 1864, p. 647.
Galago (Otolicnus) moholi, Mivart, P. Z. S., 1864, p. 647.
Characters.—Body slender; head broad and sub-globular; nose high and pointed; ears large, bare, and with narrow rounded tips; hind-limbs longer than the fore-; tail with longer hair at tip. Fur very thick and soft on body and tail. Upper side pinkish-grey, or faded white with a slight wash of pink; back, sides of body, and outer surface of limbs pearly to yellowish-white; sometimes a dark ring round the eyes; a streak down the nose white or yellowish-white; ears flesh-coloured, sprinkled with pure white down; head, face, whole of under sides and inner sides of limbs white, yellowish, or whitish-buff; tail yellowish or reddish brown, darker at tip, lighter beneath; upper surface of hands and feet white, washed with yellow. Length of body, 7-8½ inches; tail of about the same length. The male and female are of the same size and of the same colour, but the male is somewhat more washed with yellow. Muzzle shorter than the diameter of the eye-socket; the bony palate not extending past the hinder end of the median molar. Anterior and median upper molars slightly larger than the posterior pre-molar; the latter as well as the two anterior molars with a small cusp between the two front cusps.
Distribution.—This beautiful little Lemur was first recorded from Senegal, in West Africa. It occurs, however, from about 25° S. lat. in South Africa northwards to Tete on the Zambesi, through the mountainous regions of East Africa, on the shores of Lake Nyasa, to as far north as Senaar.
Habits.—The Senegal Galago is nocturnal and arboreal, occurring in the forests singly or in pairs. It makes a nest of leaves in the fork of a tree, and during its diurnal rest it either retreats thither, or composes itself on a branch, unwilling to move, and staring at passers-by, with its tail invariably folded across its body and round its neck. After sunset, these Galagos become lively, and in their movements they evince great activity; they spring from branch to branch, and even from tree to tree, with extraordinary facility (as both Sir Andrew Smith and Sir John Kirk have recorded), often clearing at single leaps distances of six feet. When seen in the dim light they may easily be taken for Bats. "They always seize with one of their fore feet the branch upon which they intend to rest. In their manners they manifest considerable resemblance to Monkeys, particularly in their propensity to the practice of ridiculous grimaces." (Sir A. Smith.) In this habit they resemble also some species of the genus Lemur. Their food consists chiefly of fruits and of insects. The female produces generally two young at a birth.
III. ALLEN'S GALAGO. GALAGO ALLENI.
Galago allenii, Waterh., P. Z. S., 1837, p. 87; Sclater, P. Z. S., 1863, p. 375, pl. xxxii.
Galago allenii, var. gabonensis, Gray, P. Z. S., 1863, p. 146.
Galago gabonensis, Mivart, P. Z. S., 1864, p. 630.
Galago (Otolicnus) allenii, Mivart, P. Z. S., 1864, p. 647.
Otogale pallida, Gray, P. Z. S., 1863, p. 140, pl. xix.
Otolicnus apicalis, du Chaillu, Equat. Africa, App., p. 471.
Galago elegantulus, Slack, Proc. Ac. Sc. Phil., 1861, p. 153.
Characters.—Head round; muzzle pointed; eyes very large; ears also very large, long, nude, and membranaceous; fingers and toes very long, slender, and fine. Tail thick, round, and longer than the body; ankle-bones elongated. Length of body, 8¼ inches; tail, 10 inches. Head brownish-grey; a narrow black ring round the eyes; a streak from the forehead down the nose whitish; back greyish-brown, washed (sometimes markedly) with rufous on the upper back, fading out towards the root of the tail; the latter black or greyish-black. Outside of arms and legs washed with rufous, sometimes with a white spot on the shoulder-joint and over the groin; posterior aspect of legs sooty-black; cheeks, sides of nose, entire under surface, and inner side of limbs creamy-white with a rufous-washed bar across the chest. Muzzle shorter than the diameter of eye-socket. Incisors seen from the side, more or less hidden by the canines; anterior upper pre-molar very canine-like, relatively much produced longitudinally, with an interval between the anterior and median pre-molars; posterior upper pre-molar four-cusped, and with an intermediate cusp on the oblique ridge; posterior upper molar almost equal in size to the median one.
Distribution.—This species has been recorded from the Gaboon, in West Africa, and from Fernando Po, whence it was first obtained by Captain Allen, R.N., in 1837.
Habits.—Although little or nothing has been recorded of its habits, it is unlikely that they differ much from those of the species already known.
IV. DEMIDOFF'S GALAGO. GALAGO DEMIDOFFI.
Galago demidoffi, Fischer, Act. Soc. des Nat. Mosc., i., p. 24, f. 1 (1806); Peters, P. Z. S., 1863, p. 380, pl. xxxv.; Mivart, P. Z. S., 1864, p. 648.
Otolicnus peli, Temm., Esquis. Zool. Mamm., p. 42 (1853).
Otolicnus demidoffi, Wagner in Schreb., Säugeth. Suppl., v., p. 160 (1855).
Hemigalago demidoffi, Dahlb., Stud. Zool., p. 230 (1856).
Galago murinus, Murray, Edinb. Phil. Journ. (n.s.), x., pp. 243-251, pl. 11 (1859).
Characters.—Head round; body short and thick; snout very narrow; long bristles on the face, corners of the eyes, and sides of the nose; ears long, oval, membranaceous, transparent, the inner margin haired; eyes large and projecting; nose elongated in front, and projecting above the upper lip; fingers slender; wrist, ankle, hands and feet short-haired; digits naked; tail longer than body, round and slender. Length, 5 inches; tail, 8 inches.
Basal part of hair Mouse-grey. Upper side reddish-brown, more rufous down the back, and on the tail, except its distal half, which is darker. Top of head and sides of face darker; a narrow white streak from the brow down the nose; ring round the eyes dark, wider on the inner side; chin, throat, inner side of limbs, and under surface of body creamy-white. In the young, which remains blind for several days after birth, the white nose-streak is less defined, and the fur is shorter and lighter than that of the parents.
Orbits approximating; front bones of jaw (the pre-maxillæ) projecting beyond the incisors; upper median pre-molar teeth with enlarged heel, and with one or two diminutive cusps; upper molars with a small cusp on the oblique ridge; wrist-bones elongated.
Distribution.—Demidoff's Galago occurs in Senegal, in West Africa, and has been obtained in Central Africa in theNiam-Niam country by Dr. Schweinfurth, and in the Monbuttu country by the late Emin Pasha.
Habits.—Writing of Demidoff's Galago in a letter from Africa addressed to Mr. A. Murray, Mr. Thomson says: "It was a most interesting and amusing pet, not only quite tame, but manifesting strong attachment. It was a very epitome of zoology, of the size and colour of a large Rat; it had the tail of a Squirrel, the facial outline of the Fox, the membranous ears of the Bat, the eyes and somewhat of the manners of the Owl in its cool odd way of peering at objects, the long slender fingers of a lean old man who habitually eats down his nails, and all the mirthfulness and agility of a diminutive Monkey. It hated its cage at night, but delighted to leap among the bars of the chairs ranged purposely round the table for it. It could clear a horizontal distance of at least six feet at a bound.... It possessed a curious power of folding its membranous ears back upon themselves and somewhat corrugating them at pleasure; and it appeared to me that the palms of its hands and feet were endowed in some degree with the power of suction.... I have seen it maintain itself in positions where the mere lateral pressure of its limbs appeared to be inadequate for the purpose.... I never saw it muster courage enough to attack either a Grasshopper or a Mantis."...
V. MONTEIRO'S GALAGO. GALAGO MONTEIRI.
Galago monteiri, Bartlett, P. Z. S., 1863, p. 231, pl. xxviii.
Callotus monteiri, Gray, P. Z. S., 1863, p. 145.
Characters.—Fur Mouse-grey at base, with white tips; pupils of eyes oval and vertical; ears very large and naked; hairs on face and cheeks short; feet broad, short, and strong; toesbroad, with rounded discs; thumb very broad; tail very long. Entirely pale grey over the head, face, cheeks, body, and tail; throat nearly white; hands and feet dark brown, nearly black; nose black; ears nearly black. One of the largest species of the Sub-family. Length, 12 inches; tail, 16 inches long.
Distribution.—This species was discovered by Mr. Monteiro in Cuio Bay on the West Coast of Africa, to the south of Loanda; and the late Captain Cameron, R.N., brought a few specimens home with him from Bailunda, on his return from his celebrated march across the Continent.
Habits.—Little is known of this species from observation in the field. A few specimens have reached Europe, and on one that lived in the Zoological Gardens in London, Mr. Bartlett made the following observation: "The animal has the power of turning its ears back by the complex muscles of their external aspect, and folding them up when at rest. When moving about or in search of food they spread out and stand upward and forward, reminding one of those of the Aye-Aye; but when folded back and down, the animal's face bears a strong resemblance to the Douroucouli (Nyctipithecus)."
VI. THE GREAT GALAGO. GALAGO CRASSICAUDATA.
Galago crassicaudatus, Geoffr., Ann. Mus., xix., p. 166 (1812).
Otolicnus crassicaudatus, Peters, Reis, Mossamb. Saügeth., t. 2, t. 4, figs. 1-5.
Otogale crassicaudata, var. kirkii, Gray, P. Z. S., 1864, p. 456.
? Galago lasiotis, Peters, S. B. Ges., Nat. Fr. Berl., 1892, p. 224.
Characters.—Hair long and woolly. Head round; muzzle more elongated than in other Galagos; nose-pad with a deepfurrow; eyes large; ears large, the upper half membranaceous and nude; tail long, thick and bushy; fourth digit of hand and foot longest; fingers and toes not united by a membrane, but with flat disc-like terminations.
Hair Mouse-grey at base, silver-grey at tips; the hair on the belly white tipped, sometimes entirely white; hairs on back longer and with black tips. General colour yellowish-brown, with a lighter band from the forehead along the centre of the nose and round the eye-circles, which are darker. Iris reddish-brown. Top of head rusty-brown; back grey; sides of body, cheeks, and outer side of limbs grey, faintly washed with rusty-red; whole under side grey or yellowish-white. Tail ferruginous; hands and feet deep rufous-brown; short hairs of digits blackish-brown. Length, 13 inches; tail, 16 inches. The female has the pelage similar to that of the male.
The coast form, which has been described as Kirk's Galago (G. kirkii), is only a variety of the present species. In it the fur is pale ashy-grey; the hairs at the base Mouse-grey, tipped with grey, with longer black hairs distributed over the body; cheeks, inner sides of limbs, and under side greyish-white; face, crown, and nape washed with reddish-brown, which extends on the outer side of the limbs; lower back more lightly washed; tail, dirty grey.
Distribution.—The Great Galago is found on the south-east coast of Africa to 24° S lat., and extends into the interior for about 140 miles from Quilimane. Kirk's Galago (G. crassicaudata, var. kirkii) is confined to the maritime regions and mangrove forests of the east coast. Sir John Kirk states that it has been observed at the Luabo mouth of the Zambesi, at Quilimane, and at Mozambique. It has also been procured at Taveita.
Habits.—This species, named by the Portuguese "Rat of the Cocoanut Palm," nestles by day among the palm fronds, its ears folded up like a Beetle's wing, and, if disturbed, it performs feats of agility, darting from one palm to another. "It will spring with great rapidity," says Sir John Kirk, "adhering to any object as if it were a lump of wet clay. It has one failing,—should a pot of palm-wine be left on the top of the tree the creature drinks to excess, comes down and rushes about intoxicated," and can then be easily caught. "It becomes active just after darkness sets in. The rapidity and length of its leaps, which were absolutely noiseless, must give great facilities to its capturing live prey. I never knew it give a loud call, but it would often make a low chattering noise."
THE MOUSE-LEMURS. GENUS CHIROGALE.
Cheirogaleus, Geoffr., Ann. du Mus., xix., p. 171 (1812).
Chirogale, Forsyth Major, Nov. Zool., i., p. 1 (1894).
In this genus are included a group of Lemurs of very small dimensions, and of which the following are the more important characters: The rounded head has a short face covered with fur. The eyes are very large and set close together, agreeing well with their nocturnal life. The ears are conspicuous, projecting beyond the fur, thin, and membranaceous. The hind-limbs are larger than the fore-, the foot being remarkably elongated by the lengthening of the heel-bone (Astragalus). The nail of the second finger is pointed, but all the rest are flat. The length of the tail exceeds that of the body. In some the orbits are directed outwards instead of directly forwards as is generally the case among the members of the Sub-order. Of the teeth in the upper jaw, the inner incisors are larger than the outer; the anterior pre-molar is as longvertically as its median neighbour; while the posterior, which is smaller than the anterior molar, has one internal and one large external cusp. Of the molars, the inner hind cusp is either small or wanting. The bony palate is long, its hind margin extending behind the posterior molar. The pre-maxillary bones, carrying the incisor teeth, are largely developed. The mastoid portion of the ear-capsules (periotic) is not inflated as in many species of Lemurs. Several of the species of this genus remain somnolent and torpid throughout the dry season, in regions where it is then impossible to obtain the vegetable food they require. The Mouse-Lemurs are confined to the island of Madagascar.
I. MILIUS' MOUSE-LEMUR. CHIROGALE MILII.
Cheirogaleus milii, Geoffr., Cours de l'Hist. Nat., Mamm., iie. leçon, p. 24 (1829).
Cheirogaleus typicus, A. Smith, S. Afr. Q. Journ., ii., p. 56 (1833).
Chirogale milii, Forsyth Major, Nov. Zool., vol. i., p. 21 (1894), Taf. ii., figs. 1, 8, 9 (with full synonymy).
Characters.—Snout pointed; eyes prominent; ears moderately large, oval, membranaceous, and sparsely-haired externally; tail Rat-like, thick at base, becoming thinner towards its extremity. Brain-case of skull less vaulted than in the true Lemurs. Bony palate prolonged behind the posterior molar, its hind perforations large; mastoid portion of ear-capsule (periotic) not swollen. No gap in upper jaw between the canines and anterior pre-molar teeth; anterior upper pre-molar canine-like, and longer than the median; no gap between the anterior and median pre-molars; posterior lower molar reduced in size. The anterior milk pre-molar changes first, the posterior next, and median last. The posterior uppermilk-molar has one inner and two outer cusps. (Forsyth Major.) Heel-bone elongated.
General colour varying considerably; top of head, neck, and upper part of back, brownish-grey or uniform delicate fawn-brown, sometimes "grizzled with silvery-grey" or washed with rufous, more especially on the head; rest of back, sides, outer sides of limbs and tail ashy-brown; under side and inner side of limbs greyish-white, or white slightly washed with yellowish. Ring round orbits and side of nose, black; space between the eyes lighter than the back of the head. Length, 7-8 inches. The young are dark Mouse-grey.
Distribution.—Milius' Mouse-Lemur, though a rare species, is widely distributed in Madagascar, being found in the Ankay Forest on the north-east coast as well as along the west coast as far south as Mouroundava.
Habits.—This beautiful little Lemur, no bigger than a Guinea-pig, is, like most of the other species of its group, nocturnal and arboreal, feeding on fruits and probably honey. It runs on all fours, but sits up to eat, holding its food in its hands. In the winter months it is believed to hibernate in hollow trees. Having scooped out a cavity big enough to contain its body, the little animal collects, according to the Rev. G. A. Shaw, sufficient loose leaves and grass to cover it; it then retires, and, burying itself in the heap, is sustained during its period of hibernation by the store of fat which, during the summer months, becomes deposited at the root of the tail, and swells the latter out to an enormous size.
II. THE BLACK-EARED MOUSE-LEMUR. CHIROGALE MELANOTIS.
Cheirogaleus typicus (nec Smith), Gray, Cat. Monkeys, Brit. Mus. App., p. 133 (1870); id. P. Z. S., 1872, p. 855 (partim), pl. lxxi., fig. 3.
Chirogale melanotis, Forsyth Major, Nov. Zool., vol. i., p. 25, Tab. ii., fig. 10 (1894).
Characters.—Very similar to C. milii, but distinguished by the far less woolly and more silky fur; face pointed; ears rounded, somewhat large, the outside and half the inside haired; lips flesh-colour. Upper side rather light brownish (almost reddish) grey; upper side of tail darker; tips of hair silvery, but less so than in C. milii. No white stripe between the eyes as in that species, the space not lighter than the top of the head and back; ears very dark brown; a dark brown ring round the eyes; a white stripe along the side of the neck. Under side of body and inner side of limbs greyish-white. Length, 10½ inches; tail, 9 inches. Skull smaller in all its dimensions than C. milii; the face longer and more tapering; the nasal bones broader before and behind; the posterior perforations in the palate large, as in C. milii; mandible less spread; the inner cusp of the anterior upper pre-molar less developed; basal heel of upper and lower canines stronger; posterior lower molar longer and with a distinct heel.
Distribution.—This species is known from a single skin in the collection of the British Museum, which was obtained at Vohima, on the north-east coast of Madagascar.
III. THE HAIRY-EARED MOUSE-LEMUR. CHIROGALE TRICHOTIS.
Chirogaleus trichotis, Günther, P. Z. S., 1875, p. 78, pl. xv.
Chirogale trichotis, Forsyth Major, Nov. Zool., vol. i., p. 26 (1894).
Characters.—Brownish-grey above; lower parts grey with the hairs white-tipped; a spot in front of the eye black; the lips and a line down the nose, white. Hands and feet grey, the hairs white-tipped. Ears short, concealed in fur, with tufts of long hair on the lower part and on the space in front of the ears. Tail shorter than the body, its hair short except forwards, where it is longer.
Skull depressed and flattened; cranial portion short.
Distribution.—The only known specimen of this species is the type in the British Museum, obtained by Crossley during his journey from Tamatave to Mouroundava.
IV. CROSSLEY'S MOUSE-LEMUR. CHIROGALE CROSSLEYI.
Chirogaleus crossleyi, Grandid., Rev. et Mag. de Zool., xxii., p. 49 (1870).
Characters.—Smaller than C. melanotis (Major); tail short and very hairy. Head very large, rounded; ears small and haired. Hind-limbs longer than fore. Upper side, especially the head, rufous; under side greyish-white. Round the eyes a black ring; inner aspect of the ears dark brown, the upper border black. (Grandidier.)
Length, 8 inches; tail, 4¾ inches.
Distribution.—Crossley's Mouse-Lemur is known as yet only from the forests to the east of Antsianak, in Madagascar.
Habits.—The two species last described (Chirogale trichotis and C. crossleyi) are very closely related together. They are nocturnal animals, and very rare; consequently but little is known of their habits. It is, however, very improbable that they depart widely from those of the better known Mouse-Lemurs.
THE DWARF-LEMURS. GENUS MICROCEBUS.
Microcebus, Geoffr., Cours de l'Hist. Nat., Mamm., leçon vi., p. 24 (1828).
Under this genus are arranged five species of very small Lemurs, whose hind-limbs are longer than their fore-, though less so in proportion than is the case among the African Galagos. Their snout is also shorter; their eyes are large, approximated together, very prominent and very bright, and their ears are elongated. On the ventral surface are situated four mammæ, two on the breast and two on the abdomen.
Of their bony framework, the brain-case is high, broad, and more vaulted than that of either the Mouse-Lemurs or the species of the next genus, Opolemur. The facial region is also shorter. The mastoid portion of the ear-capsules (periotic bones) and the squamosal region is somewhat less inflated than in Galago. With regard to their dentition, the inner upper incisor is larger than its outer fellow. Between the upper canine and the anterior pre-molar of its own side there exists no gap, nor is there a space between the anterior and the median upper pre-molars. The molars have three-cusped crowns, but these cusps are very sharp, and are weaker than those in Galago; the intermediate cusp between the two main cusps to the front is wanting. The concavity also of the hinder margin (so marked in Galago) is here very slight, but the basal ring (cingulum) is swollen internally to form an inner hind cusp. The posterior upper molar is smaller than the anterior, and its inner hind cusp is rudimentary. The hind border of the bony palate extends to behind the last molar tooth, its posterior perforations being very large. The angle of the lower jaw is not produced downwards.
The foot in the Dwarf-Lemurs is long, on account of the elongation of two of its ankle-bones (the cuboid and the naviculare).
The species of this genus are confined to the island of Madagascar. They are entirely nocturnal, as their large eyes and inflated ear-capsules might suggest. They are chiefly arboreal and frugivorous.
I. SMALL DWARF-LEMUR. MICROCEBUS MINOR.
Microcebus murinus, Martin, P. Z. S., 1835, pp. 125.
Galago minor, Gray, Ann. and Mag. N. H., x., p. 255 (1842).
? Chirogalus gliroides, Grandid., C. R., 14 Dec., 1868.
Chirogaleus pusillus, Flower and Lydekker, Mammalia, p. 690 (1891 partim).
Microcebus minor, Forsyth Major, Nov. Zool., vol. i., p. 8 (1894), Taf. i., fig. 2; ii., figs. 5-7, 14, 15 (with full synonymy).
Characters.—Head rounded; muzzle short and pointed; eyes large and brilliant; ears large and naked; tail longer than body. Length of body, 5 inches; of tail, 6 inches.
Upper side, either for the most part Mouse-grey, washed with light rufous-brown, with the stripe down the back more or less distinct and somewhat darker; or with the rufous-brown colour preponderating. In grey specimens the upper side of the tail is washed with rufous, the under side being somewhat lighter. Cheeks, throat, breast, belly, and inner side of limbs almost pure white, here and there washed with grey. Between the eyes a white stripe; over the eyes in grey specimens a rusty-brown spot. Base of the hairs slate-grey; the tips silvery. (Forsyth Major.) Skull variable; the brain-case short and high, or long and depressed; the facial region short; posteriorupper pre-molar less than the anterior molar. Length of intestine, 20 inches; cæcum blunt, 1¾ inches long; main arteries of fore- and hind-limbs not broken up into a rete mirabile of small parallel vessels.
Distribution.—This beautiful little animal, sometimes called the "Rat" of Madagascar, the smallest of all the Lemurs, is known from Ambulisatra on the south-west coast of Madagascar, and from Fort Dauphin on the south-east coast.
II. THE DORMOUSE DWARF-LEMUR. MICROCEBUS MYOXINUS.
Microcebus myoxinus, Peters, Reis, Mossamb. Zool., i., Säugeth., pp. 14-20, Taf. iii. and iv. (1852); Forsyth Major, Nov. Zool., vol. i., p. 11 (1894).
Characters.—Head Cat-like and round; muzzle pointed and broader than in M. minor. Ears large, one-third shorter than the head and short-haired; eyes large and round. Fourth digit of hand longest; second and fifth shortest. Tail longer than the body, its hair stronger and shorter than on the body, but longer at the tip and on the upper side than it is beneath. Two pairs of teats, one pair on the breast, and one pair on the abdomen.
Resembles M. minor, but is redder in colour. Back reddish-yellow, washed with ferruginous, brighter on the forehead and under the eyes; a dark brown spot on the upper and lower corners of the eyes; sides of body between the limbs, hands and wrists, feet and ankles, as well as the external margins of the limbs, and the whole under side, as well as a spot on the brow, a line down the centre of the nose, and the sides of the head and cheeks, pure white, washed with yellowish-brown.Tail golden-yellow, washed with ferruginous on the upper side, the entire distal third darker; rest of the under side of the tail paler. Naked part of ears flesh-colour. (Peters.) Hairs slate-grey at base, the tips ferruginous.
Mastoid portion of ear-capsules (periotic-bones) not so inflated as in M. minor; hind border of bony palate extending to the posterior border of the last molar, its posterior foramina being large; pre-maxillary bones very large and projecting beyond the incisor teeth; angle of lower jaw pointed and hooked. Upper inner incisors standing in front of the canines, and nearly twice the size of the outer; no gap between the canines and the anterior pre-molar; the pre-molars vertically sub-equal, and with one external cusp; molars with two external cusps, the hinder of the two united to the large inner front cusp by an oblique ridge, their inner side bounded by the cingulum; the posterior molar smaller than the two anterior. Anterior and median lower molars four-cusped; the posterior, the largest of the cheek-teeth, five-cusped.
Distribution.—The Dormouse Dwarf-Lemur inhabits the south-west coast of Madagascar; it has also been obtained at Bambotoka in St. Augustin's Bay on the west coast.
III. SMITH'S DWARF-LEMUR. MICROCEBUS SMITHI.
Microcebus pusillus, G. R. Waterh., Cat. Mamm. Mus. Zool. Soc., 2nd ed., p. 12 (1838).
Cheirogaleus smithii, J. E. Gray, Ann. Mag. Nat. Hist., 1842, p. 257.
Chirogaleus pusillus, Flower and Lydekker, Introd. Mamm., p. 690 (1891, pt.)
Microcebus smithii, Mivart, P. Z. S., 1864, p. 641; Forsyth Major, Nov. Zool., vol. 1., p. 12; Taf. ii., figs. 3, 4, 12, and 13 (1894) (with full synonymy).
Characters.—Closely related to the foregoing; the fur in most specimens less woolly than in the other species; eyes large; snout longer and more pointed; ears shorter, less than half the length of the head; ankles proportionally shorter; fingers and toes longer; fur generally darker, the tail not markedly different from the back, very Rat-like in form; the dark marks in front of the eye extending to the tip of the nose, inside of the ears more ferruginous; size about that of a Rat. Muzzle longer and more pointed than in M. myoxinus; pre-maxillæ more produced in front, and nasals more produced above the nostrils; bony palate less prolonged backwards beyond the posterior molar, the hind perforations of the latter large; the line of union of the two halves of the lower jaw shorter than in M. myoxinus; upper incisors set anterior to the canines, and distant from the inner margin of the pre-maxillæ, the inner pair larger than the outer pair; the anterior upper pre-molar less vertically extended than the median one; median and posterior lower molars having the hind outer cusp lower and longer than the front outer cusp.
Distribution.—Smith's Dwarf-Lemur is known from Fort Dauphin, on the south-east coast, from Betsileo in the centre, and from the south coast of Madagascar.
Habits.—Of the habits of both this and of the preceding species little is known, for they have rarely, if ever, been seen alive by Europeans. According to the Rev. G. A. Shaw, the present species lives in the belt of forest-land stretching from the eastern forest into the heart of Betsileo, a few miles north of Fianarantsoa, where they are tolerably abundant, frequenting the tops of the highest trees. Among these it moves about on all fours (its very stout limbs having beautifully perfect hands), using its tail as a balance by twisting it round a branch. The tail is, however, not truly prehensile, the animal only employing it to steady itself, or to hold on slightly by. This species, whose food consists chiefly of fruit and insects, builds a nest in a fork amid the smallest branches near the top of some very high tree, the female bringing forth two and sometimes three young at a birth.
IV. THE FORK-MARKED DWARF-LEMUR. MICROCEBUS FURCIFER.
Lemur furcifer, Blainv., Ostéogr. Mamm., 1841, p. 35, pl. vii.
Cheirogaleus furcifer, Isid. Geoffr., C. R., xxxi., p. 876 (1850); Mivart, P. Z. S., 1867, pp. 960-975 (skull and tarsus figured).
Lepilemur furcifer, Gray, P. Z. S., 1863, p. 145.
Phaner furcifer, J. E. Gray, Cat. Monkeys, Brit. Mus. App., pp. 132, 135 (1870).
Microcebus furcifer, Forsyth Major, Nov. Zool., vol. i., p. 16 (1894).
Characters.—Ears large and long; snout pointed; tail longer than the body, and equally haired; foot elongate. General colour reddish-grey. Unmistakably recognisable by the black dorsal streak bifurcating on the forehead into two branches, extending on the inner side of the ears and terminating over each eye.
Facial portion of skull longer than cranial; angle of lower jaw much produced backwards and downwards; hind margin of palate extending back to hinder margin of posterior molar; hind perforations of palate large; border of maxillary swollenin the canines and pre-molars. Upper anterior incisors much larger than the posterior, and both anterior to canines; anterior pre-molars canine-like, both vertically and proportionately longer than the median pre-molars of any other species of the family; median pre-molar compressed, with a fore and hind heel; the posterior pre-molar with a large internal talon. Molars comparatively small, but longer and narrower than in M. coquereli; anterior molar much larger than the posterior pre-molar, its hind inner cusp rudimentary; the posterior molar longer than the posterior pre-molar, and smaller than the other molars, its inner cusp wanting. Lower anterior pre-molar lance-shaped, vertically longer than the two posterior sub-equal grinders; molars sub-equal, much larger than the posterior pre-molar; posterior molar comparatively short, five-cusped.
Distribution.—Chiefly found on the west coast of Madagascar.
V. COQUEREL'S DWARF-LEMUR. MICROCEBUS COQUERELI.
Cheirogalus coquereli, Grandid., Rev. Mag. de Zool., xix., 1867, p. 85.
Microcebus coquereli, Mivart, P. Z. S., 1867, pp. 966-967; Forsyth Major, Nov. Zool., vol. i., p. 14 (1894; with full synonymy).
Mirza coquerelii, J. E. Gray, Cat. Monkeys, Brit. Mus. App., pp. 131, 135, 136 (1870); Schlegel, Mus. Pays Bas, vii., p. 321 (1876).
Characters.—Similar to M. furcifer, but slightly smaller; ears large, long, and almost naked; tail longer than the body; fur soft and woolly. Above dark grey, washed with rufous; tail, at base, of the same colour as the back; remainder of tail dark rufous; throat, breast, and under side of body yellowish-grey.Length of body, 8½ inches; tail, 13 inches; skull high and arched; outer and hinder portion of ear-capsules (periotic-bones) and squamosal swollen; frontal bone longer than in Opolemur and Chirogale; occiput less sloping from behind and above forwards and outwards. Upper median and posterior molars with one inner and two outer cusps, united by a curved ridge, cingulate all round, and with a small cusp or cingulum at the hind inner angle; posterior pre-molars smaller and shorter than the molars, with strong and vertically longer outer cusp, and a much more feeble inner cusp; posterior lower molar lengthened behind by a fifth cusp.
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 thatother 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 shorterand 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.