24 



Bones of the Skull. 



Os lacriniale 



Sulcus lacrimalis 



Crista lacrimalis 

 posterior 



Processus frontalis 

 maxillae 



, -Fossa sacci 

 lacrinialis 



Hamulus 



lacrimalis 



Maxilla 



28 and 29. Right lachrymal bone, os lacrimale, 



From without. From within. 



The os lacrimale (lachrymal bone) (see also Figs. 68 TO, 73 and 74) is a paired, 

 oblong, quadrangular, thin platelet of bone, the size of a finger nail, and lies in the anterior 

 part of the medial wall of the orbit. The upper margin unites with the pars orbitalis oss. fron- 

 talis (sutura fronlolacrimalis) (s. p. 17); the posterior margin with the anterior border of the 

 lamina papyracea oss. ethmoidalis; the inferior margin behind with the medial margin of the facies 

 orbitalis of the corpus maxillae (sutura lacrimomaxillaris)^ in front with the proc. lacrimalis 

 conchae nasalis iuferioris (sutura lacrimoconchalis) ; the anterior margin with the margo 

 lacrimalis of the proc. frontalis maxillae (sutura lacrimomaxillaris). The medial surface is 

 tolerably flat, lies directly on the anterior part of the lateral wall of the ethmoidal labyrinth 

 and the lateral boundary of the anterior ethmoidal cells ; the lateral surface is divided by a 

 crest extending from above downward, the crista lacrimalis posterior (0. T. lachrymal crest) 

 (for the origin of the pars lacrimalis m. orbicularis oculi), into a larger posterior level area 

 and a smaller anterior concave area, sulcus lacrimalis; the latter forms with the sulcus 

 lacrimalis of the proc. frontalis maxillae, the fossa sacci lacrimalis (for the saccus lacrimalis). 

 From the inferior extremity of the crista lacrimalis posterior proceeds the somewhat variable 

 hamulus lacrimalis (0. T. hamular process) lateralward, forward and downward ; it is inserted 

 in the incisura lacrimalis on the medial anterior margin of the orbital surface of the body 

 of the maxilla. 



