THE SKULL 371 



the opposite side, and along the inner side of 

 the nasal bone, to the mesethmoid, with 

 which it is connected. The bone is very thin 

 and elastic at its hinder end, so as to allow of 

 a certain amount of movement of the facial 

 on the cranial portion of the skull. 



The outer or maxillary process runs back- 

 wards and slightly outwards, forming part of 

 the margin of the upper jaw. The nasal and 

 maxillary processes of the premaxilla, together 

 with the superior and inferior processes of the 

 nasal bone, surround the large aperture at 

 the side of the beak in which the external 

 narial opening lies. 



The inner or palatine process, the smallest 

 of the three, is a narrow plate of bone which 

 extends horizontally backwards, a short dis- 

 tance from the median plane. It forms part 

 of the roof of the mouth, and is connected 

 behind with the anterior end of the palatine 

 bone. 



iv. The maxilla is a slender rod of bone, lying 

 behind and to the inner side of the maxillary 

 process of the premaxilla, and forming part 

 of the sub-orbital bar. Its anterior end is 

 expanded into a thin horizontal lamina of 

 bone, the maxillo -palatine process, which 

 projects inwards towards the median plane, 

 lying dorsal to the palatine bone. 

 v. The jugal is a very slender rod, which forms the 

 middle portion of the sub-orbital bar. It lies 

 dorsal to the other two components of the 

 bar, and its exact limits are almost impossible 

 to determine in the adult. 



vi. The quadrato -jugal is the hindmost of the 

 three components of the sub-orbital bar. Its 

 posterior end is thickened, and articulates with 

 the outer side of the distal end of the quadrate. 



BB2 



