THE PALATE BONES. 49 



into the posterior palatine canal in articulation with the 

 superior maxillary. The vertical portion presents for ex- 

 amination an internal and external surface, an anterior 

 and posterior border, and the orbital and sphenoidal 

 processes. The internal surface is smooth, and is crossed 

 by two oblique ridges,^the superior and inferior turbi- 

 nated crests for articulation with the middle turbinated 

 process of the ethmoid and the inferior turbinated bone, 

 respectively. Below the inferior turbinated crest the 

 bone is concave, and forms the posterior part of the in- 

 ferior meatus of the nose ; between the crests the surface 

 is slightly concave, and forms part of the middle meatus. 

 The surface is frequently grooved for small vessels, and 

 occasionally presents a foramen near the posterior border. 

 The external surface, above the angle of junction with 

 the horizontal plate, is rough for articulation with the 

 inner surface of the superior maxillary. Above the 

 rough surface is a quadrilateral, smooth, slightly concave 

 surface, which helps to close the antrum of Highmore. 

 Along the posterior portion of this surface the bone is 

 thrown into a lip, which slightly conceals the posterior 

 palatine groove. This groove curves from above slightly 

 forward, downward, and backward, and is larger below 

 tljan above. In the articulated skull the opening of the 

 canal is just above the wisdom-tooth. The anterior 

 border is thin, sharp, and irregular; it extends from the 

 orbital to the horizontal process. At its middle it pre- 

 sents a projecting, vertical plate of bone, the maxillary 

 process, which assists in closing the antrum. The pos- 

 terior border is concave, rather thick, irregular, grooved, 

 and terminates at its lower portion in the tuberosity, 

 which is a transversely expanded piece of bone, serrated 

 at its edges for articulation with the internal and external 

 pterygoid plates, with an intervening, smooth, .concave 



