Plate X. 



Trephining of Facial Sinuses. 



Cross section of the left side of the head 

 anterior to the last molar, and through the 

 widest part of the inferior maxillar\' sinus. M^, 

 last superior molar ; SINI, superior maxillary 

 sinus at its antero-iuferior extremity ; IM, in- 

 ferior maxillary sinus, lateral portion ; IM^, do. 

 median portion ; N, nasal fossa ; S, sound 

 lodged in lachrymal duct ; NF, trifacial nerve ; 

 F, frontal sinus. 



