356 



MAMMALIAN ANATOMY 



from before backward. They increase in size from within outward. 

 Beyond the alveoli is a somewhat hollow area devoid of teeth, called 

 a diastema. A portion of the lower surface which is bounded in front 

 by a curved line beginning behind the central incisor and passing out- 



FIG. 276. 



Alveolar Border. 



With Opposite Premaxillary. 



With Palatine Plate of 

 Maxillary 



Palatine Process. 



Firsf} 

 Second >j 



Left Incisors. 

 Third j 

 Horizontal Plate. 



Anterior Palatine Notch. 

 With Maxillary. 



Ascending Plate. 



LEFT PREMAXILLARY BONE, LOWER VIEW. 



ward and backward to the posterior external angle is depressed and 

 slopes upward and backward at the expense of the posterior surface, 

 to form the anterior wall of the anterior palatine notch. 



The superior surface (Fig. 277) is of small extent and confined to 

 the inner part of the bone only, because the outer part gives origin to 



FIG. 277. 



Posterior Part of Body. 



Palatine Process. 



Ascending Plate. 



Superior Surface of Body. 



Anterior Surface of Body. 

 LEFT PREMAXILLARY BONE, UPPER VIEW. 



the nasal process. It forms the lower innermost margin of the ante- 

 rior nares. 



The posterior surface is limited in front to the narrow line between 

 the superior surface and the deep emargination on the inferior surface 

 at the front of the palatine notch. At the side it slopes upward, 

 outward, and forward into the internal surface of the ascending plate. 

 A vertical slit in its sharp posterior border receives the edge of the 

 maxillary bone. 



