THE FACE. 141 



The nasal plate forms the posterior external part of the nos- 

 tril, and is much .thinner than the palate plate. Its side next 

 the nose is slightly concave, and is divided into two unequal 

 surfaces, of which the lower is the smallest, by a transverse 

 ridge, that receives the posterior extremity of the lower turbi- 

 nated or spongy bone. The external face is in contact with 

 the internal face of the maxillary bone, and presents a surface 

 corresponding with it. The nasal plate of the palate bone 

 diminishes the opening into the Antrum Highmorianum by 

 overlapping it behind. Backwards it joins the pterygoid pro- 

 cess of the sphenoid bone, and overlaps its anterior internal 

 surface. 



At the inferior and posterior part of the nasal plate, where 

 the crescentic edge of the palate plate joins it, the palate bone 

 is extended into a triangular process, called the pterygoid. 

 This process, on its posterior surface, presents three grooves, 

 the internal of which receives the internal pterygoid process 

 of the sphenoid bone, and the external groove receives the ex- 

 ternal pterygoid process of the same bone. The middle fossa 

 has its surface continuous with the pterygoid fossa of the sphe- 

 noid bone, and may be seen, in the articulated head, to contri- 

 bute to this fossa. The anterior surface of the pterygoid 

 process of the palate bone presents a small serrated tuberosity, 

 which is received into a corresponding concavity on the pos- 

 terior surface of the maxillary bone, and contributes to the 

 firmer junction of the two. 



On the external surface of the nasal plate, between it and 

 the base of the pterygoid process, a vertical groove is formed, 

 which is converted into a complete canal by the maxillary 

 bone. The lower orifice of this canal is near the posterior 

 margin of the palate. It is called the posterior palatine fora- 

 men, and transmits the palatine nerve and artery to the soft 

 palate. Immediately behind this canal there is, not unfre- 

 quently, a smaller one, running through the base of the ptery- 

 goid process of the palate bone, and transmitting a filament of 

 the same nerve to the palate. 



The upper extremity of the nasal plate is formed by two 

 processes, one in front and the other behind, separated either 



