SIMIAD^E. 427 



individuals are never precisely the same; and we were disposed, there- 

 fore, to conclude, during the early part of our stay at Sumatra, that there 

 were really different species of what, as it proved, is but one, Hylobates ; 

 for it was only after the examination of individuals of different colours, 

 and after we had killed many of both sexes, and various ages, that we 

 came to the conclusion, that the Oengko-itam, or black Oengko, and 

 the Oengko-poetih, or white Oengko, of the Malayans, were the same 

 species. Of the great number of skins which we collected, fifteen have 

 been displayed in the Museum of Leyden, all differing, more or less, in 

 colour : for example, this beautiful series, containing individuals of 

 different ages and sexes, includes some of a yellowish white colour, others 

 of a brownish yellow, and others quite black : and it is from this varia- 

 tion that some naturalists of Europe have been induced to assign to them 

 the rank of distinct species, thereby producing much confusion." 



" In all the individuals, whether of light or dark colour, that we 

 examined, we invariably found the following characters ; viz., a white 

 stripe across the forehead, or brow : many of the males, likewise, having 

 the sides of the face and the throat white : in black subjects, the lumbar 

 region and crupper are always of a paler colour than the other parts of 

 the body, and are usually of a rusty or pale yellowish brown : in the 

 pale individuals, which have a yellowish, or brownish-yellow colour, 

 the throat, the chest, and the abdomen are of a darker brown, as are, 

 sometimes, the hands also. It is interesting to find that the yellowish 

 females frequently produce black young ; and the black, as often, young 

 of a pale colour." 



To this account, by M. Miiller, it may be added, that a beautiful 

 straw-white specimen (7. c in Catalogue, 1838) is preserved in the 

 museum of the Zoological Society, London. 



Having thus pointed out the specific identity between the Ungka- 

 puti and the Ungka-etam, it remains to fill up the account by a descrip- 

 tion of the characters, which a few individuals of each variety present, 

 drawn from an examination of specimens in different museums. 



VARIETY : UNGKA-PUTI. The orbits are prominent, the eyes sunk ; 

 the index and middle toes are united together at the base ; the fur 

 is soft, deep, and woolly, being of a finer texture than that of the 

 Siamang ; the hair of the head is inclined back from the forehead ; that 

 ,if the fore-arm is directed forward, not reverted ; the general colour of 

 the head, back, and outer aspect of the extremities, is flaxen, somewhat 

 tinted with brown, and passing into a pale yellowish white on the crupper ; 

 the chest, the abdomen, and the axillae are of a dark umber brown ; as 

 are also the arms and thighs internally, and the hands and feet, though 

 less intensely ; an indefinite superciliary line, and the whiskers, which are 

 full in the male, are white ; the hairs of the eyebrows are black ; a few 

 reddish hairs are scattered around the ischiatic callosities. 



