1889.] MR. O. THOMAS ON A NEW BORNE AN MONKEY. 159 



5. Description of a new Bornean Monkey belonging to the 

 Genus Semnopithecus. By Oldfield Thomas, Natural 

 History Museum. 



[Eeceived March 16, 1889.] 

 (Plate XVI.) 



In a small collection of Mammals recently obtained by Mr. Charles 

 Hose in Baram, on the north-west coast of Borneo, and acquired for 

 the Natural History Museum, there occur several rare and noteworthy 

 Mammals. Among these may be mentioned the Trichys recently 

 referred to by Dr. Giinther \ specimens of Rhinolophus luctus, Temm., 

 of Sciuropterus davisoni, Thos., only previously known from the 

 Malay Peninsula, of Semnopithecus chrysomelas, Miill. and Schl., 

 and, finally, the subject of the present description. 



The specimen is an adult male, and as it occurred along with the 

 other Semnopithecus, one was at first tempted to suppose that it was 

 only a very aged individual of the same species, in which certain 

 parts had become white ; but an examination of the skull proves 

 that it is really quite distinct. 



I propose to call it 



Semnopithecus hosei, sp. n. (Plate XVI.) 



Size and form about as in S.femoralis, S. chrysomelas, and S. ob- 

 scurus. Crown with a longitudinal crest starting about half an inch 

 beiiind the centre of the forehead ; the longer hairs slope evenly back- 

 wards, there being uo trace of a reversed occipital tutt as there is in 

 some species. General colour of body hoary grey, a colour made up 

 by the intermixture of black and white hairs. Crest, centre of crown, 

 and nape deep glossy black, as also are the long eyebrows, and the 

 few short hairs scattered about the dark surface of the orbits. All 

 the rest of the head, the forehead, temples, sides of the crown and 

 neck, cheeks, iips, nasal septum, chin (where there is a distinct tuft), 

 and front of neck pure white, contrasting most markedly with the 

 glossy black of the central crest, and with the dark grey of the back 

 and shoulders. Outer sides of limbs like back, darkening terminally 

 in the hands and feet to deep black. Chest, underside of body, and 

 inner sides of limbs as far down as the middle of the forearm and of 

 the lower leg white, continuous with that of the chin and throat. 

 Tail hoary grey like the back throughout, only rather darker above 

 than below, owing to the larger proportion of black as compared 

 with white hairs there present. 



Skull light and delicate. Nasal bones long, thin ; profile quite 

 straight and continuous with the line of the forehead, an arrangement 

 very different from the peculiar aquiline nasal outline of *S'. chrysomelas. 



Nasal opening oval, its breadth about two thirds its height, instead 

 of three fourths as in the allied species. Bullae low, opaque. Teeth 

 as usual. 



' Supra, p. 75. 



