The palatal portion has in its caudal border a deep notch for the foramen incisivum or anterior palatine canal, which lies between it and the maxillary and transmits blood-vessels and nerves. It articulates with the maxillary bone by this border.
The medial border is raised into a thin crest of bone which, besides forming the medial wall of the foramen incisivum or anterior palatine canal, articulates by its medial border with the bone of the opposite side, forming a sort of median trough (sulcus palatinus) which projects dorsad into the nasal cavity and receives the ventral border of the nasal septum. The caudal end of this border articulates laterad with the maxilla, dorsad with the vomer.
Its craniolateral border bears the incisor teeth (a).
The nasal process (c) presents three surfaces, all elongated and triangular; one, the medial surface, is smooth and concave and looks into the nasal cavity. Its dorsal border is rough for articulation with the nasal bone dorsad, and smooth ventrad where it aids in forming the nares.
The lateral surface is smooth.
The caudal surface is rough for articulation with the maxillary bone.
Nasal Bone. Os nasale
([Fig. 30]).—The nasal bones fill the space between the nasal process of the premaxillary, the frontal process of the maxillary, and the nasal spine of the frontal bone ([Fig. 39], 7). They thus form part of the dorsal wall of the nasal cavity near the middle line.
Fig. 30.—Nasal Bone, Dorsal View.