370 Bernards on the different species of Orang-utan. [No. 4. 



of the Sumatran male begins even anteriorly to that of Prof. Owen's 

 Bornean male : the symphysis menti in both is equally developed : 

 the supra-orbital ridges, however, are much more prominent in the 

 male from Sumatra, as in Prof. Owen's Sumatran female ; but in 

 our aged Bornean female skull, they are considerably more developed, 

 proportionally, than in Mr. Owen's Bornean male. In both of Mr. 

 Owen's specimens, the palate is represented as contracted poste- 

 riorly, between the last molars on each side, to 1^ in. (or rather 

 more in the Sumatran female). In our Sumatran male the distance 

 is fully If in. ; and in the Bornean female If in. I can come to no 

 other conclusion than that all represent individual varieties of one 

 species, having perhaps a tendency to exhibit the local variation 

 which Prof. Owen has indicated. 



The same naturalist adds — " The Bornean Pongo, if we may judge 

 from the few specimens undoubtedly from that locality which exist 

 in the museums of this country, is clothed with loose long hair of a 

 deep fuscous colour, approaching in some parts to black ; the Suma- 

 tran Pongo is covered with loose long hair of a reddish-brown colour. 

 The adult male of the Bornean species has the countenance dis- 

 figured by large dermal callosities upon the cheek-bones. These do 

 not exist in either sex of the Sumatran species." It is worthy of 

 note that the term species is here bestowed, probably from the 

 remarkable difference implied by the last mentioned character. The 

 fully adult Sumatran male described by Dr. Clarke Abel, however, 

 and the skin of which is still in this Society's museum, possesses 

 the cheek callosities, less developed however than in the Bornean 

 male figured by Prof. Temminck. 



Sir J. Brooke, in his highly interesting letter already referred to, 

 besides pointing out the distinctions of two of his three species of 

 Bornean Orangs from personal observation of the living or freshly 

 killed animals wild and tame, remarks that the skulls also examined 

 by him may be divided into three distinct sorts. 



" The first presents two ridges, one rising from each frontal bone, 

 which joining on the top of the head, form an elevated crest, which 

 runs backward to the cerebral portion of the skull." To this may 

 accordingly be referred the P. Witkmbii and the P. Abelii of Owen, 

 and, it would seem, all the adult skeletons at present in Europe 



