TRANSACTIONS OF THE SECTIONS. 151 



this space being occupied by the cranial cavity. The pterygoid wings are large and 

 strong, three inches in length, with a rough outer ridge behind, the under points 

 reaching to a level with the alveolar grooves of the inferior maxilla? ; and there is a 

 distinct hamular process, somewhat resembling a finger-nail, at the under and inner 

 edge. The squamous part of the temporal bone, with its largely developed zygo- 

 matic process, abuts against the under edge of the parietal and ali-sphenoid. 



The length of the zygomatic arch is 5-j'g- inches, the depth fully 2 inches. The 

 glenoid surface is formed by a slightly raised, tuberculated, convex eminence, about 

 an inch and a half in length, and half an inch across, placed obliquely at the under 

 and fore part of the root of the zygoma. At the posterior and inner part of the 

 root of the zygomatic arch, there is a deep, smooth, ovate cavity for the support of 

 the petro-tyrapano- mastoid bones. 



The malar bone is seven inches in length, and extends from the outer edge of the 

 glenoid surface to the anterior margin of the orbital fossa. It is formed by a narrow 

 zygomatic process behind, on which the posterior two-thirds of the zygoma rests. 

 It gradually expands upwards, downwards, and forwards, into a broad maxillary 

 process, terminating in a twisted curved orbital plate, which forms the outer part of 

 the floor of the orbital cavity, and overlaps a part of the orbital process of the 

 superior maxillary bone. The superior orbital process of the malar bone projects in 

 the form of amammillated protuberance, with a deep fissure where it rises from the 

 maxillary process, and inclines towards the post-orbital process of the frontal bone, 

 being separated from the latter by an open space -^ths of an inch at the outer poste- 

 rior boundary of the orbital cavity. The temporal fossa is four inches in length, reach- 

 ing as far forwards as the fifth molar tooth, counting from before backwards. The 

 upper coronal surface measures 5A inches from the parietal ridge to the tip 

 of the nasal process of the frontal bone, and about an inch and a half across. 

 It is concave above, with a longitudinal ridge on each side diverging in front into 

 two orbital processes, at first somewhat narrow, where they bound the upper and fore 

 part of the temporal fossa, then expanding into broad thick plates, convex above and 

 concave beneath, forming the roof of the orbits. The distance from the tips of the 

 premaxillary bones to the anterior margins of the orbits is 4 inches. The orbital 

 cavities extend obliquely outwards, forwards, and downwards, the inner part of the 

 floor being formed by the broad, thick, bridge-like orbital plate of the upper maxillary 

 bones, having a large oval inferior orbital canal opening directly in front. The 

 premaxillaries are united anteriorly by a mystachial suture 2 T 3 o inches in length, 

 and extend backwards on each side of the anterior nasal fossae, by a narrow process, 

 to a little behind the fore part of the orbits. They are here connected by suture to 

 an elongated squamous cancellated bone, two inches in length, and two-thirds of an 

 inch across, which I shall call the nasal bone. At the middle of the nasal bone, 

 corresponding to the points of union between the upper maxillary and frontal bones, 

 forming the inner border of the orbits, the anterior nasal fossae expand to four 

 inches in width, and 5^ inches in length, becoming narrower both above and 

 below. The premaxillaries are compressed in front, and form, along with the ante- 

 rior part of the upper maxillary bones, a short narrow muzzle, 2\ inches in 

 length, bending downwards beak-like, at an angle approaching to thirty degrees. 

 The palate plates of the premaxillaries, anterior to the large single foramen incisivum, 

 are about an inch in length, the same in breadth, with two socket-like depressions 

 on each side, the two in front rather larger than those behind, which appear to have 

 contained four deciduous incisor teeth. The length of the palate of the skull, from 

 the incisive border of the premaxillaries to the posterior curved edge of the palate- 

 bone is 8g inches, and the breadth about an inch. From the curved edge of the palate 

 bone to the ridge marking the union of the basi-occipital to the basi-sphenoid, the 

 distance is 3 inches, making the total length of the base of the skull to this 

 point \i\ inches. 



An oval opening, an inch and a half deep, and rather less in width, forms the 

 posterior nasal aperture. It is bounded beneath by the palate plates of the palate 

 bones, which consist of two narrow pointed processes divided by a fissure behind, 

 and extending forwards about an inch, where the two small posterior palatine fora- 

 mina are situated, but which appear to be chiefly formed in the palate-plates of the 

 superior maxillary bones. The nasal plates and pterygoid processes of the palate 



