298 Zoological Society. 



which they are destined to attain by the size of the orbits, which 

 exceeds that of the orbits of the S. Morio, the eye having, like the 

 brain, already in the young Pongos acquired its full size. 



*' That the cranium of the Simla Morio here described, belonged 

 to an adult is proved by the small interval between the temporal 

 ridges at the crown of the skull, corresponding to the extensive sur- 

 face of origin of the crotophyte muscles ; and by the obliteration of 

 the intermaxillary sutures : that it belonged also to an aged indivi- 

 dual is highly probable from the extent to which the teeth are worn 

 down, and from the obliteration, notwithstanding the absence of in- 

 terparietal and lambdoidal crests, of the sagittal and lambdoidal su- 

 tures. 



" The cerebral portion of the skull of Simla Morio equals in size 

 that of the Pongo, and indicates the possession of a brain at least as 

 fully developed as in that species, while the maxillary portion is pro- 

 portionally smaller ; so that, as the cranium rises above the orbits, 

 and is, like that of the Pongo, more convex on the coronal aspect 

 than in the Chimpanzee, and wants the prominent supraciliary ridge 

 which characterizes the African Orang, it presents in the Simla Morio 

 altogether a more anthropoid character. 



" There are, however, the rudiments of the ridges which so re- 

 markably characterize the cranium of the mature Pongo. Those 

 which commence at the external angle of the frontal bone pass back- 

 wards, upwards, and slightly converge, but do not meet ; they gra- 

 dually diminish in breadth, and, after passing the coronal suture, 

 subside to the level of the skull ; they are then only traceable by a 

 rough line, which leading parallel to the sagittal suture, and gra- 

 dually bending outwards, rises again to be continued into the lam- 

 bdoidal ridges ; thus circumscribing the origins of the temporal mus- 

 cles. The lambdoidal and mastoid ridges are broader and more de- 

 veloped than in the Chimpanzee, but inferior in both respects to 

 those of the Pongo. The inial region of the occiput is almost 

 smooth, and is convex, without the mesial ridge, and strong muscu- 

 lar impressions observable in the Pongo, where a preponderating 

 weight in front calls for the insertion of powerful muscles behind 

 to counterbalance it." 



The temporal bones join the frontal in Slmia Morio as in the Tro- 

 glodytes niger; but this structure occasionally is present on one or 

 both sides of the skull in Simla Satyrns. 



The additamentum sutura lambdoidalls is present on both sides 



in speaking of the immature specimens of the great Pojigo, I therefore use 

 the term Simla Satyrus; in comparing the Simla Morio with the adtiU 

 Pongo, I would be understood as always referring to the Bornean species, 

 with cheek-callosities, or the Slmia Wurmhil of Fischer. If the specific dif- 

 ferences of Simla Wurmbii and Simla Ahelii be admitted the term Simla 

 Satyrus must merj^e into a synonym, as having been applied indiscriminate- 

 ly to the young of both these large Orangs. In each case, the generic term 

 Simla is applied in the restricted sense in which it is used by Erxlebeu in 

 his • Systema Regni Animalis,' 8vo, 1777, and with which the term PithccuSy 

 substituted by Geoffroy for the genus of Orangs^ is synonymous. 



