THE SKELETON. 37 
bone; and the orbital plate, which is the roof of the malar 
process, forming a partial floor to the orbital cavity. The 
large foramen leading from the orbital cavity through the 
orbital plate is the infraorbital foramen for the passage of 
the infraorbital branch of the superior maxillary branch of 
the fifth nerve. 
The palatine bone with its fellow helps to form the roof 
of the oral cavity and the floor of the nasal cavity. It is 
composed of two plates: one, vertical, forming the lateral 
walls of the posterior nares and the cranial part of the 
walls of the median pterygoid fossa, and a portion of the 
nasal wall of the orbital cavity; the other, horizontal, form- 
ing part of the roof of the mouth. The vertical plate 
is pierced by two foramina, the posterior palatine and the 
Sphenopalatine, each of which transmits a palatine nerve 
and artery (Fig. 16). 
The vomer is a single narrow bone which in the nasal 
cavity articulates dorsally with the mesethmoid and ven- 
trally with the palatines and the palatine plates of the 
maxillary, in the median line. This bone, with the mes- 
ethmoid and its cartilage, forms the nasal septum, dividing 
the nasal cavity into two chambers. It is best demonstrated 
by removing the palatines, when it may be seen extending 
craniad from its bifurcated articulation with the presphe- 
noid to its articulation with the premaxillaries. The caudal 
portion of the bone is expanded horizontally and articu- 
lates with the ventral ethmoturbinals. Its dorsal margin 
is bifurcated for articulation with the mesethmoid. 
The maxilloturbinal is a paired bone occupying the an- 
terior portion of the nasal cavity (Fig. 18). It is composed 
of a few scrolls which, when the nasal bone is removed, 
may be seen attached to the maxillary. It consists of a 
horizontal longitudinal plate, whose lateral border is fixed 
to the maxillary while the medial border bifurcates into a 
