THE EAR. 



417 



ear in the fact that the edges of the auricular cartilages are 

 rolled together proximad so as to overlap. There is thus no 

 gap between the tragus [g) and antitragus [h), as in man, but 

 these two structures partly overlap. 



The free edge {b) of the auricular cartilage corresponds 

 partly to the helix of man. At its 

 mediocranial angle the proximal part 

 of the auricle is composed of muscle 

 and integument only, so that the 

 cartilage when isolated presents here 

 a deep notch distad of which is 

 a prominent projecting angle, the 

 Spine {c) of the helix, which serves 

 for attachment of the adductor auris 

 superior muscle (Fig. 169, 1). Proxi- 

 mad of the spine, separated from it 

 by the deep notch, the cranial edge 

 {g) of the auricular cartilage ap- 

 proaches the caudal edge {/i), finally 

 overlapping it, so that the cavity of 

 the auricle is now completely sur- 

 rounded. This overlapping portion 

 of the cartilage is on the medial side 

 of the cavity, and in the natural state 

 is covered by muscles and integu- 

 ment, so as not to be apparent. 



That portion of the cranial edge 

 of the cartilage that overlaps the cau- 

 dal edge forms a cartilaginous plate 

 which projects proximad as a blunt ^ concha; /cartilaginous audi- 



. tory meatus;/, crista helicis; g, 



pomt; this plate is the tragus {g). tragus; //.antitragus; /.processus 

 Along the inner edge of the tragus is ""^inatus;/, eminentia conchse. 



a ridge which forms a continuation of the helix ; this is the 

 crista helicis (/). The portion of the caudal edge of the car- 

 tilage that is partly overlapped by the tragus is an irregular flat 

 plate known as the antitragus {h). At its caudolateral margin 

 the antitragus extends distad as a thin, pointed, cartilaginous 

 spine, the processus uncinatus (/). This supports a sheet of 



Fig. 168. — Cartilage of the 

 External Ear, Craniome- 

 DiAL View. 



a, scapha or pinna; /', helix, 

 c, spine of tlie helix; d, antihelix; 



