MUSCLES 43 



Reflect the sterno-mastoid muscle. 



2. The Sterno-hyoid is a similar muscle, lying be- 

 neath the sterno-mastoid, and covering the trachea 

 along the mid- ventral line. It arises on the ante- 

 rior end of the manubrium, and is inserted on the 

 basi-hyal bone. (Plate IV.) 



Reflect the sterno-hyoid muscle. 



3. The Sterno-thyroid is a slender muscle which 

 arises from the anterior end of the manubrium, 

 below the origin of the sterno-hyoid. It is in- 

 serted on the thyroid cartilage of the larynx. 

 (Plate IV.) 



4. The Digastric is a relatively large muscle, 

 situated at the angle of the mandible. It arises 

 from the skull, posterior to the external auditory 

 meatus, and is inserted along the inner surface 

 of the anterior half of the mandible. (Plates 

 II., III., and IV.) 



5. The Genio-hyoid is a small, thin .muscle, lying 

 along the mid-line of the under side of the man- 

 dible. It arises near the symphysis, and is inserted 

 on the basi-hyal bone. (Plate IV.) 



6. The Mylo-hyoid is the flat muscle forming the 

 floor of the mouth. It arises on the inside of the 

 mandible, and is inserted on the basi-hyal bone. 

 (Plate IV.) 



7. The Thyro-hyoid Muscle arises from the thyroid 

 cartilage of the larynx, and is inserted on the 



