296 Zoological Society. 



He stated that the skin of the young Sumatran Orang agreed in 

 the rufous colour, texture, disposition, and direction of the hair, with 

 the adult female Sumatran Orang, presented to the Zoological So- 

 ciety by Sir Stamford Raffles ; like that specimen also, it had no 

 nail on the hallua: or thumb of the hinder hands *. The posterior 

 molar es on each side of each jaw correspond to the first permanent 

 molares of the adult ; the rest of the teeth consisted of the 8 deci- 

 duous bicuspides, the 4 small deciduous canini, and the 8 decidu- 

 ous incisores. This state of the dentition was similar to that of the 

 human child at the 7th year ; but it would be unsafe to infer from 

 this circumstance that the age of the Orang corresponded : it being 

 more probable, from the characteristic duration of the immature 

 state in the human species, that the shedding of the teeth takes 

 place at a later period than in the Orang. 



Of the two crania of the Bornean Orangs, one differed materially 

 from the other in size and in the development of the cranial ridges. 

 The larger specimen before the Society, closely resembled the cra- 

 nium of the Bornean Pongo or adult Orang in the Museum of the 

 College of Surgeons, and differed, in precisely the same respects as 

 that specimen, from the cranium of the Pongo (supposed to be Su- 

 matran) in the possession of Mr. Cross, described and figured in the 

 1st volume of the Society's Transactions, (p. 380. PI. 53, and noticed 

 in our report of Mr. Owen's paper, in Lond. and Edinb. Phil. Mag., 

 vol. vi. p. 457), which induced Mr. Owen to entertain more strongly 

 his original suspicion, that that cranium belonged to an Orang 

 specifically distinct from the great Bornean species (Simia Wurmbii, 

 Fischer). With respect to the differences alluded to, he stated that 

 the cranium of the great Bornean Orang was characterized by the 

 more oblique plane of the orbits, and consequently the straightness 

 of the contour of the skull between the forehead or glabella and the 

 incisor teeth ; the external boundaries of the orbit were broad and 

 had a rough irregular surface, probably in consequence of the deve- 

 lopment of the callous protuberances which characterize the sides of 

 the face in the adult males of this species. The symphysis of the 

 lower jaw was also proportionally deeper than in the (supposed) 

 Sumatran Pongo. The cranium of that animal in the possession of 

 Mr. Cross, Mr. Owen regarded as being that of a male individual 

 from its size and from the development of the cranial ridges. 



The sexual peculiarities observable in the cranium of both the 

 Bornean and Sumatran Pongos are well marked, and are exemplified, 

 first in a difference of relative size, that of the female being about 

 ^th smaller ; secondly, in a much smaller development of the cranial 

 ridges ; and thirdly, in the symphysis menti being of less depth, the 

 cranium of the female approaching in these respects, according to 

 the usual law of sexual development, towards the characters of the 

 immature animal. The smaller of the crania of the two Bornean 

 Orangs, Mr. Owen regarded as indicative of a species of Simia, Erxl., 



[• See Mr. Brayley's notes on this deficiency in the Orangs, Lond. and 

 Ediub. Phil. Mag., vol. vii. p. 72.] 



