154- Anatomy of the Rabbit. 



being formed by the nasal bone. The palatine process extends 

 backward oa the medial side of the bone, closely applied on the 

 palatal surface to its fellow of the opposite side, and forms in this 

 way a medial boundary for the incisive foramen. Its dorsal 

 surface, in conjunction with that of the corresponding process of 

 the other side, bears a broad palatine groove (sulcus palatinus), 

 lodging a portion of the cartilage of the vomeronasal organ and 

 nasopalatine duct. The frontal process (processus frontalis) 

 is a thin bony splint, extending backward between the nasal and 

 maxillary bones, and terminating between the former and the 

 maxillary process of the frontal. 



14. THE ZYGOMATIC BONE. 



The zygomatic bone (os zygomaticum) is a separate element 

 only in very young animals. In the adult it is fused anteriorly 

 with the zygomatic process of the maxilla, the position of the 

 original suture being roughly identifiable as the point where the free 

 horizontal portion of the zygomatic arch arises from the transverse 

 zygomatic process. ' It forms an almost sagittal plate of bone 

 bridging the orbit and serving for the 'attachment of the masseter 

 muscle of the mandible. Its dorsal margin forms posteriorly 

 a smooth, horizontal articulation with the zygomatic process of the 

 squamosal, the end of the bone projecting considerably behind the 

 articulation. 



15. THE NASAL BONE. 



The nasal bone (os nasale) is a thin, elongated bone forming 

 the roof of the nasal fossa, and, in conjunction with its fellow of the 

 opposite side, the dorsal boundary of the piriform aperture. It is 

 loosely articulated with the maxilla and with the bone of the 

 opposite side by smooth (harmonic) sutures. The medial margin 

 is supported by the dorsal edge of the nasal septum. The internal 

 surface bears the nasoturbinal scroll. 



