362 ' Description of the Skull of the 



ferent sizes. The largest, is composed of portions of the temporal, 

 parietal, frontal, sphenoidal, and inferior maxillary bones of the 

 right side of the cranium. Saving part of the parietal near the an- 

 terior superior angle, the fragment is externally encrusted with the 

 rough calcareous matter in which it was imbedded ; while its inter- 

 nal surface being smooth enables us to trace upon it several impor- 

 tant distinctive impressions. The temporal portion of this fragment 

 is constituted of the whole of the squamous portion, the greater part 

 of the petrous, and part also of the mastoid. On the first, appears 

 the fossa for accommodating the middle lobe of the brain, marked 

 by its convolutions, and the groove of the middle artery of the dura 

 mater; on the second, the two surfaces, divided by the tentorial 

 ridge, in the anterior of which is the hiatws of Fallopius, and in 

 the posterior, the internal meatus, beyond which the bone is ab- 

 ruptly destroyed; and on the third, the deep, large fossa of the 

 lateral sinus. This portion of the bone also exhibits impressions of 

 the convolutions of the brain ; on the lower surface, in like manner 

 appears, the jugular fossa. The parietal bone is defective at its su- 

 perior posterior part ; and the external incrustation is wanting as 

 low down as the parietal protuberance. The bony surface is ren- 

 dered smooth by the removal of the deposit, exactly where it lies 

 in apposition with this surface. Its internal face shows the marks 

 of the cerebral convolutions, and the arborescent arrangement of the 

 artery before mentioned. The diploic structure and tables of this 

 bone are quite manifest at its irregular edges. The remaining frontal 

 fragments are, the external angle and a small part of the orbitar plate 

 — that part of it which is united to the apophysis of Ingrassias. The 

 convoluted phenomena are somewhat apparent here also, and there 

 are faint traces even of the coronal suture. The sphenoidal portion 

 is apparently constituted of a small part of the greater wing, the 

 cerebral surface of which alone is seen in the interstice formed by 

 the temporal, frontal, and parietal divisions, composing the middle 

 fossa. Towards the under side, imbedded within the calcareous 

 crust, are two spots of cancellated appearance, which are probably 

 the remains of the pterygoid process, and the alveolar edge of the 

 superior maxillary bone which is in immediate contact with it. 



The next in size is the occipital portion ; the right half, separa- 

 ted from the left, by a vertical section passing through the middle 

 of the bone. It is covered externally with the common crust, but 

 is designated interiorly by the crucial ridge, part of the occipital 



