370 Savage and Wyman 



forms the outline of the insertion of the temporal muscle, 

 extending in a curved direction from the external orbitar 

 process of the frontal bone, as far backwards as the posterior 

 lateral portion of the cranium, then sweeping forwards and 

 downwards, terminates in a bony protuberance, situated just 

 above the external meatus andilorius. The space comprised 

 superiorly between these two depressions, forms a slightly 

 elevated ridge or belt on the coronal region, one and a half 

 inch wide in the centre, but slightly increasing in width as it 

 approaches the occiput behind, or the superciliary ridges in 

 front. The latter, which form so striking a characteristic in 

 the living animal, are still more conspicuous in the cranium 

 when denuded of its soft parts, projecting to the distance of 

 half an inch beyond the central portion of the frontal region, 

 and at the superior external angle of the orbit in front of the 

 temporal fossae they project to the distance of an inch, so 

 that, when the skull is viewed in front, they project beyond, 

 and conceal the outline of, the lateral portions of the cranium. 

 Professor Owen, in describing the sutures, says, '' the cra- 

 nial sutures which are obliterated in the adults of the Ourang, 

 the syndactylous apes, and frequently in the adult crania of 

 the baboons, are for the most part, persistent in the Chimpanzee, 

 and the coronal and sagittal sutures, have the true denticulated 

 structure. The sagittal suture is not continued along the 

 frontal bone. The squamous suture is partially lost, but suffi- 

 cient remains to show that the anterior angle of the temporal 

 joins the frontal, and separates the parietal bones from the 

 sphenoidal, as in six out of seven skulls of the Chimpanzee 

 which I have examined."* The sutures thus persistent, have 

 been distinctly figured in the plate representing a lateral view 

 of tlie cranmm. In the present specimen scarcely any of 

 the sutures, belonging to any portion of the cranium are 

 persistent. Coossification on the coronal and lateral regions 

 has proceeded so far, as to render it almost impossible to 

 trace even the position which the sutures formerly occu- 



Op. cit. vol. i, p. 346. 



