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 long vertically 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 upper milk-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.