CHARACTERS.--Nearly related to _S. obscurus_. Hair on the side of the head, and in front of the ears, long, projecting outwards; that on the top of the head long and directed backwards; beard short; face almost nude, bluish-black; lips thinly furnished with short yellowish hairs. General colour of the body everywhere black, except on the shoulders, the fore-limbs to the wrist, the joint of the legs, the back and sides of the head, and tail, which are washed with pale grey. Length of body, 19½ inches; of tail, 29 inches. The adult female is similar in coloration to the male. In the skull the orbits are rounded, and the inter-orbital region elongated. Dr. Anderson observes: "The differences which exist in certain dimensions between the skulls of well-authenticated examples of the two sexes are far greater than are generally found in the same sexes of different species." DISTRIBUTION.--Northern Tippera hills; Assam; and Mount Mooleyit, in Tenasserim. Dr. Anderson observed it in the Valley of the Tapeng, in the centre of the Kachin hills in Upper Burma, and in the defile of the Irawaddy. HABITS.--This species inhabits the thick forest, and is found in troops of from thirty to fifty individuals, distributed, according to Dr. Anderson, over three or four high forest-trees overhanging the mountain streams. It is generally tame and fearless. {103}II. THE BONNETED LANGUR. SEMNOPITHECUS PILEATUS. _Semnopithecus pileatus_, Blyth, J. A. S. Beng., xii., p. 174 (1843); xiii., p. 467 (1844); Wagner in Schreb. Säugeth. Suppl., v., p. 30, pl. xxvi., fig. 3 (1855); Hutton, P. Z. S., 1867, p. 946; Schl., Mus. Pays-Bas, vii., p. 57 (1876); Anderson, Zool. Exped. Yun-nan, p. 13 (1878); id., Cat. Mus. Calc., p. 40; Blanford, Faun. Brit. Ind., Mamm., p. 37, fig. 9 (1891). _Presbytis pileatus_, Blyth, J. A. S. Beng., xvi., p. 735 (1847); id., Cat. Mamm. As. Soc. Mus., p. 12 (1863); id., Mamm. Burma, p. 11 (1875). _Semnopithecus potenziani_, Bp., C. R., xliii., p. 412 (1856). _Presbytis chrysogaster_, Licht.; Peters, P. Z. S., 1866, p. 429; Blyth, Mamm. Burma, p. 10 (1875). _Semnopithecus chrysogaster_, Licht.; Peters, M. B. Akad. Berl., 1879, p. 830, pl. iv.b; id., P. Z. S., 1866, p. 429; Blanford, Faun. Brit. Ind., Mamm., p. 38 (1891).