660 



Jacob Parsons Schaeffer. 



ing of the dorsal end of the processus uncinatus at this point 

 (fig. 49), From the infundibulum ethmoidale the sinus maxil- 

 laris develops, hence in the adult the latter sinus communicates 

 with the infundibulum ethmoidale, and only indirectly via the 

 hiatus semilunaris with the meatus nasi medius (fig. 18). 



Supra bui tar furrow 



Celiulat ethmoidalea 

 Superior bullarfold 



~~ Buf/ar/urrow 



— ^ ^-^J>.'" ' -. — Inferior biillarfold 



\ — ^c^^j it frahnlhr furrow 



'^^^^ — hifutiflibuiar fold 

 ^hifuiidib. fllimoufale 



ProcesHUs utiriualus 

 ^Si/tits muxilltiris 



Fig. 31 (X 3.9) Drawing of a frontal section of the left nasal fossa of a term 

 fetus (series D, slide 5). 



Note the individual folds comprising the bulla ethmoidalis, and the fold lat- 

 eral to the infundibulum ethmoidale, and the furrows that border these folds. 

 The cell that is indicated in the superior bullar fold is an extension from the 

 suprabullar furrow, and the cell indicated in the concha media communicates a 

 few sections farther dorsally with the meatus nasi medius (compare with fig. 35). 



The superior bullar fold or concha. The superior bullar fold or 

 concha is located immediately inferior to the suprabullar recess 

 (fig. 31). It may continue independently ventrally and supe- 

 riorly almost to the cribriform plate of the ethmoid bone. In 

 other cases it may be fused at certain points with the attached 

 border of the concha nasalis media (figs. 41 and 43). It is fre- 

 quently continuous with one or more frontal folds (fig. 41). It 

 usually comes to form the chief bulk of the adult bulla ethmoidalis. 



