372 Remarks on the different species of Orang-utan. [No. 4. 



We have also another and complete skeleton of an adolescent 

 female, which lived twelve years in Calcutta in the possession of 

 J. Apcar, Esq., and was very young when he received it. The last 

 molars above and below had just pierced the gums. The skin of 

 this individual is mounted in our museum, possessing hair of a very 

 dark colour on the crown, back and arms. Having passed its life in 

 close captivity, with nought to call forth the vigorous action of its 

 muscles, their development with that of the osseous system gener- 

 ally would seem to have been considerably affected, and the skull 

 retains a remarkably juvenile (which in this case means anthropoid) 

 expression, contrasting greatly with that of our other and aged 

 female skull already noticed. But making every allowance for differ- 

 ence of age and a life of close imprisonment, and the other specimen 

 had in all probability been captured when fully adult, there remain 

 some extraordinary discrepancies, which probably indicate a further 

 specifical distinctness. All the bones of the aged animal are more 

 robust than those of the other ; but while the leg-bones and the 

 humeri of the two are of the same length, or at all events the 

 humerus of the aged animal does not exceed by f in. that of the 

 adolescent, the radius of the aged specimen is 2 in. longer than that 

 of the other. 



The differences in the form of the skull are very considerable. 

 The younger individual has the face conspicuously shorter and 

 broader, with circular orbital cavities, while those of the aged animal 

 are perpendicularly oblong. The vertical span of the orbital cavity 

 is 1^ in. in the aged specimen, If in. in the other ; horizontal span 

 of the same li in. in the former, If in. in the latter. In the younger 

 individual the orbital process of the frontal and that of the malar 

 bones form together a projecting angle where united by the suture ; 

 in the other they do not angulate at all. Extreme breadth of bony 

 orbits in the adolescent specimen 4 in. ; in the other 3f in. The 

 zygoma of the aged individual, as before remarked, is much more 

 slender than in the skull figured by Prof. Owen ; in the younger, 

 the malar portion of the zygoma is even broader than in Mr. Owen's 

 specimen. The nasal orifice of the aged skull is much larger than 

 that of the other. The development of the alveolar portion of the 

 jaws is also much greater in the aged animal ; whence the chin 



