processes are received into sockets in the nasal plates of 

 the prefrontal bones. The pterygoid process is an elongated 

 plate of bone which projects backwards from the dorsal 

 portion of the posterior end of the body, anteriorly the 

 process is flattened from side to side, but further back is 

 flattened from above down. The orbital laminae of the 

 palatines articulate with the edges of the body dorsally, 

 and cover the whole of the superior aspect (fades tecta) 

 of the pterygoid process [10]. The ventral surface forms 

 the median portion of the naso-palatine fossa [11]. Pos- 

 teriorly the process articulates with the pterygoid [12]. 



The Prefrontal (Os praefrontale) [Figure 13] lodging 

 the superior recess of the nasal cavity [3] and forming the 

 anterior wall of the orbit [see fig. 46] consists of a stout 

 body [1] and a twisted nasal plate [2]. The body as seen 

 from above is of irregularly hexagonal outline. The anterior 

 border [4] forms the dorsal boundary of the anterior narial 

 aperture. The medial margin (mnvijo sau'tttulis) \o] articu- 

 lates with the opposite prefrontal. The frontal margin [0| 

 presents medial and lateral segments forming an angle with 

 one another. The orbital margin forms the upper part of 

 the anterior boundary of the orbit [see fig. 45]. The 

 maxillary margin [7] confluent with the outer edge of the 

 nasal plate forms with it an area for articulation with the 

 prefrontal process of the maxilla. The attachment of the 

 nasal plate crosses the inferior surface of the body from 

 the hinder end of the sagittal to the junction of orbital and 



deflected forward to the juii«-t i< >n of maxillary and nasal 

 margins of the body. Behind the attachment of the nasal 

 plate the body forms the anterior no rton of the roof of the 



