320 



MAMMALIAN ANATOMY 



the hyoid arch, which is suspended from the cranium and supports the 

 larynx and the root of the tongue. 



The immovable part of the face (Fig. 248) is formed principally 

 by the paired palatine, maxillary, and premaxillary bones, each of 



FIG. 248. 



Right Nasal. 



Anterior Nasal Aperture, 

 Left PremaxHlary 



Right Maxillary (Nasal Process). 



Right Lachrymal. 



-Right Maxillary (Body). 



Right Malar. 



Vomer. 



Right Palatine. 



BOXES OF THE FACE. VIEWED FROM BEHIND, ABOVE, AND THE RIGHT 



SIDE. (Natural size.) 



which sends a process upward to form a part of the wall of the nasal 

 cavity, and a process inward to form a part of the horizontal partition 

 between the nasal cavity and the mouth. 



The paired nasal bones close-in the nasal cavity in front ; the 

 lachrymals contribute a small part of the nasal-orbital wall ; each 

 convoluted maxillo-turbinal projects from the inner surface of the 

 maxillary into the nasal cavity, and the malars form the outer boun- 

 daries of the orbits and join the temporal bones of the cranium to 

 complete the zygomatic arches. 



The only unpaired bone of the face, the vomer, is continuous with 

 the base of the cranium ; it is attached behind to the presphenoid and 

 in front to the floor of the nasal cavity, which is thus below the level 



m 



of the cranial base and permits the nasal chambers to open behind 

 under the sphenoid bone. 



THE PALATINE BONES. 



General Description. The Palatines are thin, irregular bones, 

 which form the middle lower part of the inner walls of the orbits, 

 and, joining each other in the middle line below, complete the posterior 

 portion of the roof of the mouth (Fig. 249). Each bone consists of 



