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may be called cerato-hyoid, and distinguished by the names 

 external, middle, and internal. The ninth is a remarkable muscle, 

 the hyo-glossus. 



1st. The sterno-hyoid, (Fig. 2. a) a strong muscle, is attached 

 by its posterior extremity to the lower and back of the sternum, and 

 by its anterior one to the body of the os hyoides. 



2d. The sterno-ceratoid, (h) at its origin from the sternum, is 

 partly concealed by that of sterno-hyoid. It runs forwards and out- 

 wards, and is inserted into the outer extremity of the posterior cornu 

 of the os^hyoides. 



Sd. The omo-hyoid ("c) is long and slender, and interrupted 

 about its centre by a short tendon. It proceeds from the scapula to 

 the middle of the os-hyoides, passing in its course along the iimer side 

 of the sterno-ceratoid. These three muscles serve the office of draw- 

 ing back the os-hyoides and tongue. 



4th. The mylo-hyoid* is a superficial muscle. It arises from the 

 whole length of the ramus of the lower jaw, and from the skin 

 along side of the neck, and running thence inwards, joins its fellow 

 of the other side, underneath the os-hyoides. It supports the parts 

 contained in the mouth and throat, while at rest, and while per- 

 forming the complicated actions of prehension and mastication of 

 insects. 



5th. The genio-hyoid consists of two parts; one internal, slender 

 (d) arises a little to one side of the symphysis of the lower jaw, and 

 is inserted into the posterior part of the body of the os-hyoides. 

 The other (e) somewhat more external, is larger and stronger, and 

 inserted into the whole length of the posterior cornu. A part of 



• This muscle I have deemed it unnecessary to delineate. I have retained the name previously 

 given to it, though I could not discover any attachment between it and the os-hyoides. It 

 might, I think, be better named platisma myoides. 



