Mr. Owen on the specific distinctions of the Orangs, 297 



equally distinct from the great Pongo of Borneo (Simla Wurmhii, 

 Fischer, Synopsis Mammalium, p. 32, No. 43), and from the Orang 

 of Sumatra {Simla Abelii, Fischer, Ibid. p. 10, No. 2*); and whilst 

 regretting that his conclusion as to the specific distinction of the 

 smaller Orang, (which, ceteris paribus , must be at least one third less 

 than either of the two preceding Orangs) necessarily reposed on a 

 comparison of the cranium alone, he at the same time observed that, 

 as the cranium in question was in every respect entire, and with 

 the series of teeth complete, it served to establish that deduction on 

 the sound basis of dental and osteological characters. 



Mr. Owen therefore proposed to designate the lesser Orang of 

 Borneo, Simla Morlo, and proceeded to describe the cranium as fol- 

 lows : 



" The size and form of the cranium of the Simla Morlo at first 

 suggests the idea of its being an intermediate stage of growth be- 

 tween the young and adult Slmia Satyrus, or Pbngo; but this is dis- 

 proved by comparison of the teeth of S. Morlo, with the permanent 

 teeth in the adult Pongo, and with the deciduous ones in the 

 young Simla Satyrus, as well as with the germs of the permanent 

 teeth concealed in the jaws of the latter. For while the teeth of 

 S. Morlo are much larger than the deciduous teeth of the young 

 S. Satyrus, they have different relative sizes one to another from those 

 w'hich are observed in the permanent teeth of the full-grown: the 

 molar es and blcuspldes of the S. Morlo being smaller, the canlnl much 

 smaller, while the upper Inclsores have nearly, and the lower in- 

 cisores fully, the same dimensions as those of the great Pongo. 



" The teeth in the jaws of a quadrumanous cranium may be known 

 to belong to the permanent series, by the absence oit\\Q foramina, 

 which, in an immature cranium, are situated behind the deciduous 

 teeth, and which lead to the cavities containing the crowns of the 

 permanent teeth, lliis character is very conspicuous on comparing 

 the cranium of Simla Morlo with that of a young Simla Satyrus, in 

 which the deciduous series are present, together with the first per- 

 manent molares. The deciduous teeth in the young Orang, besides 

 their smaller size, are more or less protruded from their sockets, and 

 thrust apart from one another by the vis a tergo of their huge suc- 

 cessors, while the teeth of <S. Morlo are lodged firmly in the jaws ; 

 and, with the exception of the characteristic inten^al between the 

 canines and incisors, are compactly arranged in close contiguity with 

 each other. 



" I have re-examined with much interest several crania of imma- 

 ture Orangs, in order to ascertain if any of these might be the young 

 of the species in question ; but they have all presented the crowns 

 of the permanent molares of too large a size, — of a size which shows 

 that the great Pongo, either of Wurmb or Abel, represents their adult 

 statef. And these immature crania also indicate the condition to 



f The permanent teeth in the Bornean and Sumatran Pongos so closely 

 correspond in size and shape that I am unable to refer the ci-ania of the 

 immature Orangs which I have hitherto examined to either species exclu- 

 sivelv from comparison of the crowns of the concealed permanent teeth ; 



Third Series. Vol. 10. No. 61. April 1837. 2 Q 



