SEMNOPITHECUS. 13 



An adult female (tj'pe) skull, when compared with a male skull with the 

 dentition perfect, presents these characters ; it is considerably larger and has the 

 interorbital region much more vertical. I observe that in S. ohscurus, a female of 

 that species is also distinguished from the male skull not only by amore vertical 

 but by a longer and narrower interorbital region. Indeed, the differences that 

 exist in these respects between the skulls of well-authenticated examples of the 

 two sexes are greater than are generally found to exist between the same sexes 

 of different species ! 



Taking the characters of this form as a whole, there can be no doubt that its 

 nearest ally is S. obscurus. In his original description of the species, Blyth stated 

 that his types were from the province of Ye in Tenasserim, but in his catalogue of 

 mammals * he afterwards assigned them to the Tippera hills on the authority of the 

 Reverend Mr. Barbe, the original discoverer of this monkey. 



I observed this species in 1868 in the valley of the Tapeng in the centre of the 

 Kakhyen hills, in troops of about thirty to fifty monkeys, usually distributed over 

 three or four high forest trees overhanging the mountain streams that debouch into 

 the Tapeng. Being seldom disturbed they permitted a near approach. 



In the defile of the Irawady above Mandalay on the left bank of the river this 

 species is also met with in the patches of thick forest which occur in that 

 locality. 



* Semnopithecus pileatus, Blyth. 



The Assam entellus monkej/, Blyth, Journ. As. Soc. vol. xvi. 1847, p. 732. 



Semnopithecus pileatus, Blyth, Journ. As. Soc. Bengal, vol. xii. 1843, p. 174; Ibid, vol. xiii. 1844, 

 pp. 467, 476; Horsfield, Cat. Mam. E. Ind. Co. Mus- 1857, p. 7; Wagner, Schreher, 

 Siiugeth. Suppl. vol. v. 1855, p. 30; Hutton, Proc. Zool. Soc. 1867, pp. 946, 950. 



Preshytis pileatus, Blyth, Journ. As. Soc. Bengal, vol. xvi. 1847, pp. 735, 1271, jil. xxvi. fig. 3; 

 vol. xliv. 1875, ex. no. p. 11; Cat. Mamm. As. Soc. Mus. 1863, p. 12. 



J'reshyiis chrysogaster, Licht. Peters, Proc. Zool. Soc. 1866, p. 429. 



Semnojnthevus potenziani, Pr. Bonap. Comptes Rendus, vol. xliii. 1856, p. 412. 



A black-faced crestless monkey, somewhat smaller than S. entellus. Long, black 

 supraciliary hairs outwardly divergent. Hairs on the vertex not elongated, but 

 somewhat longer than those on the occiput and temples, which they impend and 

 produce a capped appearance. The whiskers before the ears long and outwardly 

 divergent and hiding the loAver half of these organs, and continued down the 

 sides of the cheek to the chin as a short but distinct ruff. The upper surface 

 of the head dark ashy grey, tending to black, and contrasting with the reddish- 

 yellow whiskers and beard, but more or less tinged M'itli ferruginous, which is 

 occasionally rather well marked on the front of the forehead. The rest of the upper 

 parts, including the neck, the upper half of the brachium, and the lower half of the 

 limb below the elbow, the outside of the thighs, and the whole of the tail dark 



' L. ('., p. 14, 



