Frontal sinus. 



Posterior chamber of eyeball. 



Antrum of Highmore. 



Body of lower jaw. 



Fissure of Rolando. 



Insula. 



Lateral sinus. 



Middle ear. 

 Styloid process. 



Lateral mass of atlas. 



PLATE XX. Sagittal section of head through middle of left pupil viewed from the 



left side. 

 Line of section is marked 3 in plate XV. 



