Comparative Osteology of the Orang Utan and Chimpanzee, 467 



portance as a specific character from the fact that the individual 

 dissected at the Society's Museum a few years since had very per- 

 fect, but small, black nails, and two phalanges, and that the same 

 number o^ phalanges exist in the natural skeleton of Lord Amherst's 

 Orang in the Museum of the College of Surgeons. The phalanges 

 of the other toes are remarkably elongated, and those of the first 

 series are curved. The middle toe is longer than the rest, while in 

 the Chimpanzee it barely surpasses the second. The concavity of 

 the great toe is turned more towards the other toes than in the Chim- 

 jmnzee, (in which that toe is also longer, having always two phalan- 

 ges in addition to the metatarsal bone,) is set more forwards on the 

 internal cuneiform bone, and has its concavity directed more towards 

 the sole of the foot. The resemblance to the human foot is conse- 

 quently greater in the Chimpanzee than in the Orang. 



In conclusion Mr. Owen adverted to a fine specimen of the skull 

 of a Pongo in the possession of Mr. Cross, of the Surrey Zoological 

 Gardens, which presents the following differences when compared 

 with the skull of the Pongo in the Museum of the College of Sur- 

 geons. 



It is shorter in the antero-posterior diameter, and rises higher at 

 the vertex. The supraorbitary ridges are more prominent; the 

 plane of the orbits is more vertical, and their lateral exceeds their 

 perpendicular diameter. The profile line of the skull is concave 

 between the glabella and incisor teeth, while, in the specimen in the 

 Museum of the College, it is almost a straight line between the same 

 parts. The symphysis of the jaw from the interspace of the mesial 

 incisors to the origin of the genio-hyoidei muscles, measures g-J- 

 inches in Mr. Cross's specimen, but equals S^ inches in the Pongo in 

 the College Museum. There is also a remarkable difference in the 

 position of the zygomatic suture. In the Pongo of the College Mu- 

 seum it commences at the distance of a quarter of an inch from the 

 orbital process of the malar bone, and extends obliquely backwards 

 to within H inch of the origin of the zygomatic process of the tem- 

 poral bone. In Mr. Cross's specimen the same suture commences 

 8 lines from the orbital process of the malar bone, and extends to 

 within 10 lines of the origin of the temporal zygomatic process, so 

 that it is much nearer the middle of the zygoma. 



With these differences, however, there exist the same form and 

 proportions of the teeth, and the same peculiarities oi the foramina 

 and sutures which distinguish the Orang from the Chimpanzee. So 

 that although the difference in the shape and general contour of the 

 two skulls, is greater than is usually observable in those of other 

 wild animals, yet Mr. Owen does not consider them sufficient to af- 

 ford grounds for a distinction of species. He thinks it, however, 

 probable that they may be indicative of varieties of the Orang in- 

 habiting distinct localities, and remarks that it would be interesting 

 with that view to compare the crania of ascertained specimens from 

 Borneo and Sumatra, to which Islands this very remarkable species 

 appears to be confined. 



302 



