On a uew Species 0/ Semnopitliecus. 271 



distinct but ol)tusc 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 arc subangulate in the middle, slightly approxi- 

 mating l)ut scarcely curved from tliere to the front and hind 

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

 The uppermost (third) tooth of the front tiljia 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 vf Semnopithecus (Semno- 

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

 SART, Professeur an Mus(^iim d'liistuire naturelle de Paris. 



[Plate VII.] 



The Gibbons and Semnopitheci * of the Oriental region of 

 ludo-Cliina are up to the present time very little known, and 

 some recent papers, on the genus Hylohates in particular, 

 have onl}^ succeeded in further confusing the synonymy of 

 the species. So far as regards Tonkin (and Semnopithecus 

 nema'us being left out of account) the only species known 

 from this region is Semnopithecus fravgoisi, Pousargues f, 

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

 from further north, appears very distinct from it, although 

 taking its place in the same subgenerie group. 



Semnopithecus (Lophopithecus) poliocephalus, ?p. 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 thigh.s. 



* I preserve for tliis genus the name, generally adopted, of Semno- 

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

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

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

 given which would assure it the priority over the former. Moreover, 

 other naturalists have adopted Fi/gathrix, E. Geoffi'oy, 1812, which itself 

 is posterior to Lasiopi/r/a, lUiger, 1811, fouiided likewise on the Simia 

 nemcea of LinniS. 



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



