CHARACTERS.--General colour dark yellowish-brown, with a wash of red on the flanks in some specimens; the tail tufted. This species is at once recognised by the bald triangular wrinkled area between the eyebrows, of a milky-white colour, the rest of the face being deep black, except the flesh-coloured lips. It is also remarkable for the erect median crest over-arching the forehead; and by the long dependent black hairs on the cheeks from near the nose, increasing in length on {134}the hindmost part of the cheek, and reaching nearly to the shoulder. The skull has a highly arched, narrow and retreating forehead; the facial portion is short. DISTRIBUTION.--South-east Borneo, where it is very rare. XXV. THE DOUC LANGUR. SEMNOPITHECUS NEMÆUS. _Simia nemæus_, Linn., Mantiss. Plant., p. 521 (1771); Schreber, Säugeth., i., p. 110, pl. xxiv. (1775). _Cercopithecus nemæus_, Erxl., Syst. Règn. An., p. 42 (1777); Kuhl, Beitr. Zool., p. 8 (1820). _Pygathrix nemæus_, Geoffr., Ann. Mus., xix., p. 90 (1812). _Lasiopyga nemæus_, Desm., Mamm., p. 54 (1820); Gray, Cat. Monkeys Brit. Mus., p. 13 (1870). _Semnopithecus nemæus_, F. Cuv., Hist. Nat. Mamm., livr. 14 (May, 1825); Martin, Mammif. Anim., p. 459 (1841); Wagner in Schreb. Säugeth. Suppl. v., p. 35 (1855); Schl., Mus. Pays-Bas, vii., p. 64; Anderson, Zool. Res. Exped. Yun-nan, p. 40 (1878; with full synonymy). _Presbytis nemæus_, Blyth, J. A. S. Beng., xliv., p. 11 (1875). CHARACTERS.--Head without a crest. The naked face, the callosities, and the naked portions of the hands and feet yellow; head brown, with a narrow band of chestnut passing under the ears backwards, and a second but broader one, margined with black, across the chest, from shoulder to shoulder; whiskers long and directed backwards, pale grey--the hairs ringed with black and white; upper surface of the body and sides grey; base of the neck, chest, and shoulders as well as the upper part of the fore- and hind-limbs, with the hand and feet, black; the forehead paler; the fore-arm to the middle {135}of the hands, the rump, posterior region of the loins, and the tail pure white; the lower portion of the hind-limbs to the middle of the feet reddish-brown. Tail shorter than the body. Length of body, 25 inches; of tail, 20½ inches. In the skull the forehead is low, the intra-orbital region broad and the facial portion broad at the base. (_Anderson._) The thumb is well developed. The foetus is remarkable for its motley coloration, and shows also the white rump-spot. FEMALE.--Like the male. The young differ but little from the parents. Aged individuals retain the coloration of their maturity. DISTRIBUTION.--Northern Cochin-China; Hainan. (_Meyer._) HABITS.--The Douc goes about in large troops. XXVI. THE BLACK-FOOTED LANGUR. SEMNOPITHECUS NIGRIPES.