PALATINE BONE. 



69 



inferior part of the orbital fossa, the border which separates it 

 from the external surface being part of the orbital ridge. The 

 base is thin, and articulates with the superior maxilla, and above 

 the base is a serrated border which articulates with the lachrymal 

 bone. 



The malar articulates with the superior maxilla, the lachrymal, 

 and squamosal bones. 



LACHETMAL BONE. 

 (Fig. 12. 6.^ 



This is situated at the supero-auterior part of the orbital fossa ; 

 it is an irregular bone, very tbin and very light, and presents 

 three surfaces and a circumference. 



The external or facial surface is triangular, slightly convex, 

 and bounded, posteriorly, by the orbital ridge, in the middle of 

 which is an eminence, the Idchrymal tubercle, to which the 

 orbicularis palpebrarum muscle is attached. The posterior or 

 orbital surface, also triangular, is concave and smooth; it presents 

 near its centre a funnel-shaped cavity, the lachrymal fossa, \i\i\c\\ 

 leads to the lachrymal canal, and gives lodgment to the lachrymal 

 sac. The lesser oblique muscle of the eye is attached in a slight 

 depression at the inner side of this cavity. The internal surface 

 IS divided by the prominent wall of the lachiymal canal into two 

 concavities, and forms part of the roof of the maxillary sinus. 

 The circumference is very rough, and denticulated for articulat- 

 ing with the frontal,! nasal, superior maxillary, and malar bones. 



PALATINE BONE. 

 (Fig. 13. 11.) 



This bone is situated at the posterior part of the palatine plate 

 of the superior maxilla, and forms, with its fellow, the anterior 

 and external boundaries of the posterior nares. It is a long 

 narrow bone, flattened from side to side, and curved inwards 

 anteriorly, to meet the opposite palate bone, where it becomes 

 flattened horizontally. It presents four surfaces and two extre- 

 mities. 



The external or orh'tal surface is smooth posteriorly, where it 

 forms part of the orbital fossa, and aids in the formation of the 

 maxilliary hiatus, and denticulated anteriorly, where it articulates 

 with the superior maxilla. Infero-posteriorly it presents a 



