THE BONES OF THE SKULL. 155 
16. THE VOMER. 
The vomer is the median, somewhat sickle-shaped, vertical 
plate of bone separating the ventral portions of the nasal fossae. 
It is visible from the palatal surface through the incisive foramina, 
but its extent is best shown in the divided skull. It forms a 
support for the ventral border of the nasal septum, and its pos- 
terior portion bears a shelf-like projection, the ala vomeris, which 
assists in the support of the ethmoturbinal. 
17. THE LACRIMAL BONE. 
The lacrimal bone (os lacrimale) is a small element lying in the 
anterior wall of the orbit. It is loosely articulated with the sur- 
rounding bones, and in the dried skull is frequently missing unless 
care has been taken to keep it in place. It consists of a basal 
portion, somewhat rectangular on its orbital surface, and of two 
processes, namely, the subcutaneous process and the hamulus 
lacrimalis. The subcutaneous process is the prominent hook-like 
projection extending laterad beyond the orbital rim. The hamulus 
lacrimalis isa small process, directed toward the nasal cavity. It 
bears a groove which, in association with a corresponding groove 
of the maxillary bone, forms the first portion of the nasolacrimal 
canal. 
18. THE PALATINE BONE. 
The palatine bone (os palatinum) forms the poste ior portion 
of the palatine bridge and the major portion of the lateral wall of the 
nasopharynx. It consists of two  portions—horizontal, and 
perpendicular. The horizontal portion (pars horizontalis) is 
that lying in the plane of the palatal surface. It is articulated 
in front with the palatine process of the maxilla, the suture between 
the two bones enclosing the greater palatine foramen, the 
ventral termination of the pterygopalatine canal. The perpen- 
dicular portion (pars perpendicularis) is the vertical plate ex- 
tending backward from the palatine bridge. Its medial surface is 
divided by a low ridge into a dorsal portion, in particular relation 
to the nasopharynx, and a ventral portion, in relation to the oral 
