HEARING. 



'91 



curved and depressed. The outer projecting rim is the helix; anterior to 

 the helix is a second elevation, called the antihelix, which describes a curve 

 partially around a deep depression which leads to the meatus, called the 



FIG. 183. 



Vertical Section of the Meatus Auditorius and Tympanum. (Scarpa.) a, cartilaginous part 

 of the meatus ; b, osseous portion ; c, membrana tympani ; d, cavity of the tympanum ; e, Eusta- 

 chian tube. 



FIG. 185. 



FIG. 184. 



FIG. 184. Inner view of the Membrana 

 Tympani in the Fretus, with the Malleus at- 

 tached, a, membrane or drum of the tym- 

 panum ; 6, malleus ; c, band of circular fibres 

 at the circumference ; d, inferior, and e, supe- 

 rior tympanic artery ; /, tympanic bone. 



FIG. 185. Plan of the Ossicles in Position in the Tympanum, with their Muscles, a, cavity of 

 the tympanum; 6, membrana tympani; c, Eustachian tube; d, malleus; e, incus; /, stapes 

 g, laxator tympani muscle ; h, tensor tympani ; i, stapedius. 



concha. Between the helix and antihelix is the fossa of the helix. The 

 antihelix bifurcates at its superior portion, and encloses the fossa of the anti- 

 helix. Projecting posteriorly from the anterior portion of the concha is a 



