556 



THE AUDITORY APPARATUS 



membrana tympani immediately below the membrana flaccida. 

 The processus anterior (O.T. gracilis] is a slender spicule of 

 bone which passes anteriorly into the petro-tympanic fissure. 

 It almost invariably breaks in detaching the malleus from the 



Neck 



Facet for Head 



incus | Processus 

 anterior 



Processus 

 lateralis 

 Manubrium Manubrium 



A B 



FIG. 240. The Left Malleus. (Howden.) 



A. Posterior aspect. B. Medial aspect. 



adult skull, but it can be easily preserved in the skull of an 

 infant. 



The incus is shaped somewhat like a praemolar tooth in 



Articular surface for 

 head of malleus 



Body 



Crus breve 



Crus_ 

 longum 



Processus 

 lenticularis 



FIG. 241. The Left Incus. (Howden.) 

 A. Anterior aspect. B. Medial aspect. 



which the roots are very divergent. It presents a body and 

 a long and a short crus. The body is provided with an 

 articular surface, which looks anteriorly and articulates with 

 the head of the malleus. The short crus is directed posteriorly, 



