60 OSTEOLOGY. 



shallow groove, running obliquely downwards and forwards, and 

 terminating in the palatine surface; bounded externally by the 

 alveolar tuberosity of the superior maxilla, it forms the staphy- 

 line groove for the passage of the staphyline artery and nerve, 

 and the palatine vein. In the centre, also running obliquely 

 downwards and forwards, is a deep groove, which, with a similar 

 groove in the superior maxilla, forms the palatine foramen. The 

 spheno-palatine foramen is in its superior middle. The inferior 

 or palatine surface is smooth, very narrow, and concave, and forms 

 half of the palatine arch. The internal or nasal surface is smooth 

 and concave, the anterior portion being narrow, and bent inwards 

 to meet its fellow ; the posterior part being broad, and presenting 

 a roughened line, which runs obliquely from above downwards 

 for the attachment of the pterygoid bone. The superior or 

 sphenoidal surface is deeply excavated, assisting in the forma- 

 tion of the sphenoidal sinus. The sharp ridge between this and 

 the nasal surface is the palatine crest, on which the vomer rests. 



The anterior extremity is flat, and curved inwards to meet the 

 opposing palatine bone and palatine process of the superior maxilla. 

 The posterior extremity is very thin and sharp, and presents exter- 

 nally a depression, in which the pterygoid process of the sphenoid 

 bone articulates. The space between the palatine bones is termed 

 the posterior nares, the borders of the opening or palatine arch 

 giving attachment to the velum pendulum palati. 



The palatine articulates with its fellow, and with the superior 

 maxilla, the vomer, pterygoid, sphenoid, ethmoid, frontal, and 

 inferior turbinal bones. 



PTERYGOID BONE. 



This is a very small elongated bone, flattened from side to side 

 and slightly twisted, situated on the inner side of the pterygoid 

 process of the sphenoid, and posterior part of the nasal surface of 

 the palatine bone, and below the posterior part of the vomer. It 

 presents two surfaces and two extremities. 



The external surface articulates with the palatine and pterygoid 

 process of the sphenoid bone ; the internal surface is smooth and 

 covered by the pharyngeal mucous membrane ; the posterior ex- 

 tremity is very slender, and assists in forming the Vidian conduit ; 

 the anterior extremity possesses a blunt process, the summit 

 which is free, directed downwards, and has a groove at its 



