On a new Species 0/ Semnopithecus. 271 



distinct but obtuse angle on each side. The forehead is 

 distinctly but not closely punctured and not impressed in 

 the middle. The pronotum is well punctured, rather closely 

 in the middle, where there is a slight longitudinal groove in 

 the anterior part, and less closely at the sides. The lateral 

 margins are subangulate in the middle, slightly approxi- 

 mating but scarcely curved from there to the front and hind 

 angles, of which the former are acute and the latter obtuse. 

 The uppermost (third) tooth of the front tibia is very feeble. 



The distinctive features of the male are as in M. indica. 



The single specimen was taken by the late E. T. Atkinson. 



XXXIII. — On a new Species of Seniuopithecus (Semnc- 

 pitliecus poliocephalus) from Tonkin. By E.-L. TllOUES- 

 SART, Professeur an Musdum d'llistoire naturelle de Paris. 



[Plate VII.] 



The Gibbons and Semnopitheci * of the Oriental region of 

 Indo-China are up to the present time very little known, and 

 some recent papers, on the genus Hylobates in particular, 

 have only succeeded in further confusing the synonymy of 

 the species. So far as regards Tonkin (and Semnopithecus 

 nemoius being left out of account) the only species known 

 from this region is Semnopithecus fratigoisi, Pousargues f, 

 which is from Kouang-Si. The following species, which is 

 from further north, appears very distinct from it, although 

 taking its place in the same subgeneric group. 



Semnopithecus (^Lophopithecus) poliocephalus, sp. n. 

 (PI. VII.) 



In this monkey the head, which is entirely white as far as 

 the shoulders, is sharply distinguished from the rest of the 

 pelage, which is black above and beneath excepting a grey 

 tint on the thighs. 



* I preserve for this genus the name, generally adopted, of Sevino- 

 pithecus, F. Cuvier, 1821, until authors come into agreement as to what 

 should have priority. Presbytis, Eschscholz, is of the same year 1821, 

 but the exact date either of the day or of the month has never been 

 given which woiild assure it the priority over the former. IMoreover, 

 other naluralists have adopted Fygathria-, E. Geoffrey, 1812, which itself 

 is posterior to Lasiopyga, llliger, 1811, founded likewise on the Si7nia 

 uemcea of Linn6. 



t ' Bulletin du Museum d'Histoire naturelle de Paris,' 1898, p. 319. 



