THE SINUS FRONTALIS 



151 



/ 



S.lrorvt. 



Ost.lro at 

 lafun.cl.eth: 



F os. 



FIG. 55. SPECIMEN TWENTY-THREE YEARS, SEVEN MONTHS, AND THIRTEEN 



DAYS OLD. LATERAL VIEW OF FRONTAL, ETHMOID AL, MAXILLARY, AND A 



PORTION OF THE SPHENOIDAL AREAS. (Series D, No. 94.) 



The dotted line outlines the extent of the sinus sphenoidalis. The sinus 



sphenoidalis and the sinus maxillaris are both unusually small for an adult. 



(Compare with preceding figures.) Note also the unusually large fossa canina. 



The sinus frontalis developed from an infundibular cell. Cel.eth.ant., Cellulse 



ethmoidales anterior; Cel.eth.post., cellulae ethmoidales posterior; S.sph., 



sinus sphenoidalis; N. optic., nervus opticus; A^.car.int., arteria carotis interna; 



N.abduc., nervus abducens; Gang.semi., ganglion semilunare; Tub.aud., tuba 



auditiva; Lam.lat., lamina lateralis processus pterygoidei; Fos.ca., fossa 



canina; Duct.na.lacr., ductus nasolacrimalis; Infund.eth., infundibulum eth- 



moidale; Ost.front., ostium frontale; S.front., sinus frontalis. 



