THE SINUS FRONTALIS 



155 



17 lb 15 i 



12. U 10 9 



FIG. 57. SPECIMEN THIRTY-EIGHT YEARS OLD. HORIZONTAL SECTION FROM 

 WHICH THE SOFT PARTS HAD BEEN REMOVED BY MACERATION. (Series 

 E, No. 15.) 



Plane of section is 9 mm. inferior to the level of nasion, or 4 mm. inferior to 

 the level of the sutura zygomaticofrontalis. 1, Os nasale; 2, lamina per- 

 pendicularis ossis ethmoidalis; 3, infundibulum ethmoidale; 4, cellulae eth- 

 moidales anterior; 5, lamina papyracea ossis ethmoidalis; 6, sulcus infra- 

 orbitalis; 7, cellula ethmoidalis posterior; 8, processus orbitalis ossis palatini; 

 9, fissura orbitalis inferior; 10, fissura orbitalis superior; 11, foramen opticum 

 (inferior surface); 12, sinus sphenoidalis; 13, sella turcica; 14, foramen 

 lacerum; 15, foramen rotundum; 16, foramen ovale; 17, foramen spinosum; 

 18, cellulae ethmoidales posterior; 19, os zygomaticum; 20, facies orbitalis 

 maxillae; 21, cellulae ethmoidales anterior; 22, os lacrimale; 23, ductus naso- 

 lacrimalis; 24, infundibulum ethmoidale. 



