Body yellowish-white; a spot on the top of the head dark brown, sometimes washed with rufous, separated from the face by a white frontal bar. Face black; eyes brownish-yellow; interior of ears black, and naked; a grey patch on the middle of the back; outer aspect of the fore-arms, and hind-legs, ashy-grey; rest of the body white. Hands and feet white. Tail yellowish-white. Length of body, 18 inches; of tail, 22 inches.
Young.—Entirely white, with a dark brown spot on the head; the under surface of the body washed with rufous.
Varieties.—Two well-marked varieties of this species are known, both of which were for many years considered to be distinct species. Continued exploration has, however, now resulted in the accumulation in various museums of a large amount of material from many localities, and this proves that the two forms really belong to but one species.
VON DER DECKEN'S SIFAKA. PROPITHECUS DECKENI.
Differs from the true P. verreauxi in having the face and ears black, and the body otherwise entirely grey, or white, washed more or less with yellow (sometimes rufous on the limbs); or of an ashy-grey colour on the loins, neck, and outer aspect of the limbs; the under side bright rufous; chest and inner sides of the limbs rusty-white, with a fulvous spot at the base of the tail. Specimens from the forests of the interior have a grey spot on the back of the neck expanding into a collar, which is absent in those from the coast. An albino variety comes, so far as is at present known, only from the wooded belts on the extensive plains between the rivers Manambolo and Manjaray, on the west coast.
COQUEREL'S SIFAKA. PROPITHECUS COQUERELI.
(Plate XI.)
Has the face naked and black, but the centre of the nose white; the ears showing as black points amid the white hair; head and back of neck white, slightly washed with yellow; outer side of arm and fore-arm dark maroon-red, the lower border fringed with long white hair; a maroon patch on the upper and outer surface of the thighs, lighter on the chest and central part of the belly. Loins dark rusty-grey; hands white; tail rusty-grey.
Distribution.—Verreaux's Sifaka, with its two varieties, is confined to the small thin woods on the sandy and almost rain-less plains along the western and southern coasts of Madagascar. The type-form is found, alone, and unassociated, in the extensive plains of Mesozoic geological formation—between the southern base of the eastern range of mountains and the River Tsidsubon, which flows into the sea on the west coast. Von der Decken's Sifaka inhabits the middle of the west coast, while Coquerel's Sifaka has its home further to the north. It occupies the area between the south side of Narendry Bay and the north side of Bembatoka Bay, the Betsiboka River being its extreme southern limit.
Though first observed by Flacourt, and described by him in 1661, Verreaux's Sifaka remained practically unknown from that time till re-discovered by M. Grandidier in 1867.