Mr. A. R. Wallace on the Orang- Utan or Mias of Borneo. 475 



the same species, the adult male of which will, I believe, now be 

 made known for the first time. The skins of the two small 

 males and of the females, now on their way to England, in spirits, 

 will, when strictly compared, serve to determine accurately the 

 characters of the two species of Bornean Orang, Simia Satyrus 

 and >S^. Morio. 



The Dyaks of N.- Western Borneo, however, have names for 

 three species of Mias, although I could never find any one who 

 could determine them with precision. All the animals with 

 large cheek-excrescences form the '^ Mias chappan" but they 

 declare that females are also found of the same form. Authen- 

 ticated female specimens, however, with cheek-excrescences do 

 not exist in Europe, and if they ever do occur, seem far too rare in 

 proportion to the males to be any other than an accidental 

 variety in which the one sex has assumed characters generally 

 confined to the other. All Orangs of smaller size and without 

 cheek-excrescences are called by the Dyaks Mias Kassu, and my 

 small males and females are undoubtedly of this kind ; but these 

 people have asserted that every female I shot was a Mias Kassu, 

 so that I am rather inclined to think that they have regarded 

 the larger males as distinct species from the smaller and differ- 

 ently formed females. In one case however they said that a 

 female was a Mias chappan, though it possessed no cheek-excres- 

 cences, nor differed from the other females except in having the 

 skin of the throat rather more loose and inflated than usual, — a 

 character generally very prominent in the large males. The 

 third kind they call the Mias rambi, and they say it equals the 

 " chappan '^ in size, but has no cheek-excrescences and very 

 long hair. This seems very rare, and is probably one of the 

 large species in which the excrescences have been little or not at 

 all developed. One of my females they asserted with hesitation 

 to be a " rambi,^^ but I could not perceive that it in any way 

 differed from the others except in a much paler colour than 

 usual. 



The conclusions therefore at which I have arrived are aS 

 follows : — 



1. That two species of Orang have been ascertained to exist in 

 Borneo. 



2. The differences between them are well marked in the males, 

 but much less distinct in the females. 



3. That all the females are characterized by the small- sized 

 skull without prominent ridges and by their subtruncated dilated 

 canine teeth. 



4. The males of both species possess large conical canines. 



5. That the form, size and proportions of the crania, and the 

 size and position of the teeth, vary in each individual to such an 



