183 



THE SKELETON. 



sphenoid behind : quite posteriorly are seen the sphenoidal turbinated bones, 

 the orifices of the sphenoidal sinuses and the articulation of the alse of the 

 vomer with the under surface of the body of the sphenoid. 



Fig. 133. Roof, Floor, and Outer Wall of Nasal Fossa. 



cf ditto 



Inftvivr L'u rbinatcil 

 hilatt 



Su.jK.ruir Mcatw* 

 Middle- Cactus 

 - inferior 



floor 



Ant. Nasal Sjnite 



Palate froc.of Su?-Max 



Palate. Proc. cffa/att. 



Post. Natal Spin*- 



Ant. Falatiiif Canal 



The floor is flattened from before backwards, concave from side to side, and 

 wider in the middle than at either extremity. It is formed in front by the 

 palate process of the superior maxillary; behind, by the palate process of the 

 palate bone. This surface presents, from before backwards, the anterior nasal 

 spine; behind this, the upper orifice of the anterior palatine canal; internally, 

 the elevated crest which articulates with the vomer; and behind, the suture 

 between the palate and superior maxillary bones, and the posterior nasal spine. 



The inner wall, or septum (Fig. 134), is a thin vertical partition, which separates 

 the nasal fossae from one another; it is occasionally perforated, so that the fossa? 

 communicate, and it is frequently deflected considerably to one side. It is 

 formed, in front, by the crest of the nasal bones and nasal -spine of the frontal; 

 in the middle, by the perpendicular lamella of the ethmoid; behind, by the 

 vomer and rostrum of the sphenoid; below, by the crest of the superior maxil- 

 lary and palate bones. It presents, in front, a large triangular notch, which 

 receives the triangular cartilage of the nose; above, the lower orifices of the 

 olfactory canals ; and behind, the guttural edge of the vomer. Its surface is 

 marked by numerous vascular and nervous canals and the groove for the naso- 

 palatine nerve, and is traversed by sutures connecting the bones of which it is 

 formed. 



The outer wall (Fig. 133) is formed, in front, by the nasal process of the 

 superior maxillary and lachrymal bones; in the middle, by the ethmoid and 

 inner surface of the superior maxillary and interior turbinated bones; behind, 

 by the vertical plate of the palate bone, and the internal pterygoid process of 

 the sphenoid. This surface presents three irregular longitudinal passages, or 



