APPENDIX B 



tinge is much less extensive and pronounced on the outer hind part of the 

 members, where the fur is shorter and of a warmer hue. On the fore limbs 

 this colouring is uniform to above the wrist, and probably continued so on the 

 upper side of the paws, though it is not possible to speak with certainty in 

 regard to the extremities of the hind legs in consequence of their having been 

 amputated too high. A large longitudinal black patch starts from the centre 

 of the vertex i| in. behind the line of the eyebrow, widening over the top of 

 the cranium, maintaining an even breadth for a space, and gradually contracting 

 again as it foUott's the middle of the back of the neck from the nape to the 

 beginning of the shoulder-blade, where it fines to a point. This marking is in 

 no way similar in shape to the more or less dark and sometimes vaguely defined 

 semicircular cap in other species. H. pileatus (Gr.), H. Mulleri (Mart.), 

 H. Javaiiicus (Mtsch.). 



In the monkey in question the length of this streak, 5i in., much exceeds its 

 breadth, which at its maximum is only i| in. Its width is clearly defined, giving 

 it the appearance of a long black stem in strong contrast to the surrounding 

 yellow surface. On the brow in front of this black patch the hair is of a 

 uniform rather light yellow turning to deep orange tawny on the cheeks, sides 

 of head, chin, throat, under side of neck, and top of the chest as far as the 

 breasts. Upon the remainder of the chest, stomach, and inner face of the limbs 

 the covering is fairly long but not thick, and of a regular pale yellow. Just 

 over the eyes the yellowish-white hair mixed with a few silky black threads 

 traces a narrow border on the superciliary arch too faint to merit the name of a 

 frontal band. The bald skin of the face is dark brown ; and the ears, of the 

 .same colour, are rounded, minute, and entirely hidden in the surrounding growth, 

 although bare themselves save for some long black hairs on their inner edge, 

 which meet at the top of the cavity in a thin tuft. 



On account of these different peculiarities I have thought it proper to distinguish 

 this Gibbon specifically under the name of Hylobates Hetirici in honour of Prince 

 Henry of Orleans, to whom its discover)- is due. This particular skin was taken 

 at Lai-Chau (Tonkin), a little to the north of the Black River and not far from 

 the southern frontier of Yiinnan. 



I do not believe the H. Heiirici can be considered to be a hitherto unrecorded 

 variety of an already known species in the regions of the vicinity. The females 

 of the lar and hoolock Gibbons from Burmah and the north of Siam often change 

 their coat to a yellow somewhat resembling that of the H. Henrici, but paler 

 and mostly of a yellowish-grey, with the white whiskers and frontal band always 

 visible. It is further to be noted that neither Blyth nor Anderson, who had 

 many opportunities for close study of a large number of these animals, have 

 ever recorded the presence of a black cephalic patch, and this peculiarity is 

 moreover cited as a distinctive characteristic by ^I. Matschie in his review of 

 the species of the genus Hylobates} 



Among the females of the species H. pileatus (Gr.) of Siam and Cambodia, the 

 roots of the hair are not yellow, but vary from white in the young to brown turning 

 to grey in the adults ; the black cephalic patch, either oval or semicircular, is shaped 

 like a skull-cap of about equal length and breadth, which only involves the vertex, 

 and is divided from the eyebrow line by a narrow white band ; while, lastly, as soon 

 as the first signs of the coif become manifest, there appears on the chest a corre- 

 sponding black patch which spreads rapidly with the maturity of the animal, covering 

 the abdomen, mounting beneath the neck to the throat, and in old females reaching 

 even the chin and the whiskers. 



^^'ould it not seem likely, on the other hand, that the H. Henrici may be 

 identical with the yellow Gibbon of the island of Hainan which .Swmhoe- has 



' Matschie. — Sitzber, Ges, natttrf. Fr., Berlin, pp. 209, 210. 1893. 

 - Proc. Zool. Soc. London, p. 224. 1870. 



421 



