1905.] ME. K. I. POCOCK OX A HAIXAX GIBBOX. 175 



Again, Pousargues * believed hainanus to be established upon a 

 specimen of the same species as the type of H. nasutus, from 

 Tonkin. This belief was also based upon resemblance in colour. 

 I^othing else is known of the characters of nasutus except the 

 alleged presence of a '' fine and delicate little nose," whence the 

 name was derived. But since hainanus is not distinguishable from 

 other Gibbons by the fineness and delicacy of its nose, judgment 

 on the synonymy suggested by Pousargues must be suspended 

 until the type of nasufios has been re-examined and described. 

 Trouessart, who may have seen the type, gives nasutus the rank 

 of a subspecies of the Hainan form. 



No further justification need, I think, be sought for retaining 

 the name hainanus for the subject-matter of these remarks. 



Description of the Sj^ecies. 



Face, ears, palms of hands, soles of feet, and skin black, the 

 face with a slightly brownish tinge ; iris and exposed portion 

 of eyeball blackish. Colour of hair either unifoi-mly black, with 

 shining ti]3S, or grey, the roots of the hair being tinged with fawn or 

 washed-out brown, their exposed portion shining with silver-grey 

 lusti-e in reflected light, but of a more stone-grey in direct light. 

 During the change from black to grey, the coloration is a mixture 

 of the tAvo, the black or the grey predominating according to the 

 nearness of the time of observation to the incipience or com- 

 pletion of the change. 



On the crown of the head a median longitudinal black patch 

 with ill-defined edges and extending posteriorly as a narrow 

 evanescent stripe persists. A few scanty hairs upon the penul- 

 timate phalanx of the fingers and toes and the long hair on the 

 brow also remain black. The hair on the body and limbs is 

 longish, soft, and thick, but depressed and smooth. It is not 

 woolly in the sense that the hair of our 3'oung Lar Gibbon is 

 woolly, i. e. much resembling a Sheep's fleece ; nor does it exhibit 

 the fine and silky woolliness of the skin of II. agilis in the British 

 ]\Iuseum. On the forehead and crown of the head the hair is 

 shorter, fine, and close, and in the living specimen grows some- 

 what a la PoTtiipadour^ being erect on the crown and almost 

 porrect on the forehead, so that the head has the appearance of 

 being very much higher than in our living example of the Hoolock 

 {R. hoolock) and in adult skins of H. lar, H. pile<:it%is, and 

 II. leuciscus in the British Museum, in which the hair lies smoothly 

 backwards. The difference may be briefly expressed by saying 

 that in our Hainan Gibbon the hair looks as if it had been 

 brushed up, whereas in the others it looks as if it had been 



* Bull. Mus. Paris, 1900, p. 272. Pousargues gave A. Milne-Edwards the credit of 

 naming nasutus. Milne-Edwards, however, published no description of the species 

 v/lien the name was quoted (Le Naturaliste, 1884, p. 497). Hence it seems that 

 Kiinckel d'Herculais, who first associated the name with definite characters, must be 

 regarded as the author (Science et Nat. ii. no. 33, p. 86, 1884). 



