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A MANUAL OF ANATOMY 



from the inner angle of the eye to the olfactory pit. This groove is called the 

 naso-optic, or oculo-nasal, groove, and it indicates, deeply, the position of the 

 lachrymal duct. In the bottom of this groove a solid epithelial cord makes 

 its appearance, which, becoming hollow, forms the nasal duct. The upper 

 extremity of the duct bifurcates, its two divisions becoming connected with 

 the margins of the eyelids hear their inner ends, and forming the lachrymal 

 canaliculi. The lower end of the nasal duct, after the completion of develop- 

 ment, opens into the lower part of the nasal cavity. The lachrymal sac is 

 the upper expanded extremity of the nasal duct. 



Auricle. 



The auricle, or pinna, is that part of , the external ear which projects 

 from the side of the head. It is somewhat pyriform, with the 

 broad end upwards, and it presents two surfaces, outer and inner. 



Darwin's Tubercle , 



Scaphoid Fossa . 

 (Fossa of Helix) 



Helix 



Antihelix^ 



Concha' 



Crus Antihelicis Superior 

 Fossa Triangularis 

 '%< ^''(Fossa of Antihelix) 



Helix 



Crus Antihelicis Inferior 



Crus Helicis 



'sL Tragus 



_ Orifice of External Auditory 

 Meatus 



-~»,Incisura Intertragica 

 *\Antitragus 



Lobule 



Fig. 484. — The Right Auricle (External View). 



The outer surface is irregularly concave, and presents certain 

 elevations and depressions. About its centre there is a largo 

 deep fossa, called the concha, which leads to the meatus auditorius 

 extemus. Towards the upper and anterior part of the concha 

 there is an elevation, called the crus helicis, which is directed 

 upwards and forwards to the anterior border of the auricle. The 

 concha is thus divided into two parts, upper and lower. In front 

 of the concha there is a small, somewhat conical, prominence, called 

 the tragus, which projects slightly backwards over the orifice of the 

 meatus auditorius externus, and is provided with hairs on its inner 

 aspect. A short distance behind the tragus, and on a lower level 

 than it, there is another prominence, called the antitragus, which 

 is separated from the tragus by a deep notch, called the incisura 

 intertragica. The skin over the antitragus is also provided with 

 hairs. Below the antitragus and incisura intertragica is the most 

 dependent part of the auricle, called the lobule, which is compara- 



