MUSCLES OF THE TRUNK. 283 



of the concha, and generally composed of two fasciculi, it is covered by the skin 

 and the conchal band of the attollens maximus, while it covers part of the internal 

 scuto-auricularis muscle. 



When this muscle contracts, it principally participates in producing the 

 rotatory movement that carries the opening of the concha outwards. 



4. Cekvico-auriculares (Retrahentes Aurem) Muscles (Fig. 168). 



Three in number, and situated behind the ear, these muscles are broad, thin 

 bands, extending from the cervical ligament to the conchal cartilage. With 

 regard to their position at their origin, they may be distinguished as external^ 

 middle, and internal ; the situation of their point of insertion in the concha also 

 permits their being classed as superior, middle, and inferior. 



The retrahens externus, or superior or superficial cervico-auricularis, closely 

 united to the attollens maximus, and covered by the skin, covers the medius and 

 internus muscles. Attached by iis terminal extremity to the middle of the 

 posterior face of the concha, it draws that cartilage backwards and downwards. 



The retrahens medius, or middle cervico-auricularis, comprised at its origin 

 between the other two, and intimately attached to them, especially the deep one, 

 is in relation with the skin for the greater part of its superficies. Its terminal 

 extremity is very wide and thin, and passes over the upper end of the parotid 

 gland, to be inserted outwardly into the base of the concha, after being slightly 

 insinuated beneath the abducens. This is a rotator muscle, turning the opening 

 of the ear outwards and backwards. 



The retrahens internus, or inferior or deep cervico-auricularis, concealed beneath 

 the upper extremity of the parotid, to which it adheres closely, is inserted at the 

 base of the concha. Its action is similar to that of the middle muscle. 



5. Parotido-auricularis (Abducens, or Deprimens Aurem) 

 (Figs. 168, 7 ; 170, 17). 



Lying on the external face of the parotid gland, this is a long, thin, ribbon- 

 like band, narrower and thicker at its upper than its lower extremity. It arises 

 on the tissue of the gland, and terminates outside the base of the concha, below 

 the inferior commissure formed by the two borders of that cartilage. 



Covered externally by a very thin portion of the cervico-facial panniculus, 

 the abducens is an abductor of the ear, inclining it outwards. 



6. Temporo-auricularis Internus (Attollens Posticus) (Fig. 170, 2). 



Situated beneath the superficial muscle of this name, and partly covered by 

 the retrahens externus, this muscle is long and triangular in shape, bright-red in 

 colour, and extending transversely on the surface of the temporalis ; it is attached, 

 inwardly, to the sagittal or spur-like ridge of the parietal bones, and outwardly, 

 by means of a small tendon, to the inner side of the concha, within the terminal 

 insertion of the retrahens externus auricularis. It is an adductor of the ear. 



7. Scuto-auricularis Internus (Fig. 170, 16). 



This is a muscle composed of two short, pale fasciculi, which cross each other 

 very obliquely, are concealed beneath the scutiform cartilage and the scuto- 

 auricularis externus, and lie directly on the adipose cushion of the ear. They 



