THE SUPERIOR MAXILLARY BONE. 



39 



slightly outward and downward, enters the substance of 

 the bone, and terminates below the anterior border, at 

 the infra-orbital foramen ; a branch of this canal descends 

 in front of the antrum in the substance of the bone. 

 The infra-orbital canal transmits the superior maxillary 

 division of the fifth nerve. 



The Circumference of the Superior Surface. The 

 inner border anteriorly is notched, smooth, and assists 

 in forming the lachrymal canal; behind this it is 





Inrttivt fat, 



Fio. 17. SUPERIOR MAXILLARY BONE. 



serrated, somewhat cellular, and articulates from before 

 backward with the lachrymal, lower border of the os 

 planum of the ethmoid, and the orbital surface of 

 the palate. The posterior border is directed obliquely 

 backward and outward, is somewhat rounded, presents 

 at its centre the beginning of the infra-orbital groove, 

 and forms the greater part of the lower boundary of 

 the spheno-maxillary fissure. The anterior border is 

 directed obliquely outward and backward ; at its angle 

 with the posterior border is a rough, trilateral, irregular 



