OF DroELPHYS VIRGINIANA. 95 



connected with that bone by flxscioe. It is wholly muscular ; its fibres are directly trans- 

 verse ; it arises from the inside of the alveolar border of the lower jaw, from the border of 

 the pterygoid to the symphysis, and unites with its fellow along a median raphe. 



Genio-hyoideus. — A large flat strip lying in apposition with its fellow along the median 

 line, arising fleshy from the body of the hyoid, narrowing as it passes forward to be in- 

 serted by a slight tendon into the symphysis. 



Genio-hyo-glossus. — This muscle, with its fellow, forms a thick, vertical, fan-shaped par- 

 tition between the hyo-glossi. It arises, internal to the preceding, from the inner surface 

 of the anterior border of the hyoid body. Its lower border, running straight to the sym- 

 physis, lies upon the foregoing. Its fibres cannot be traced more than half way to the tip 

 of the tongue ; its upper border becomes lost in the substance of the tongue (lingualis), 

 and blends with the hyo-glossus. 



Hyo-glossus. — A large muscle, forming a great part of the tongue. It arises fleshy 

 from the lower border and most of the side of the hyoid, forming a broad, oblique plane, 

 separated from its fellow by the foregoing muscle. Passing into the tongue its fibres can 

 be traced along the side and under surface, even to the tip. Above and internally, it 

 first blends with the foregoing, and is afterwards lost in the lingualis. Of the latter, it is 

 unnecessary to say more than that it forms the fleshy substance of the tongue not 

 included in the two foregoing muscles, and is without osseous attachments. 



" Stylo'' -hyoideus — A cylindrical muscle of rather large size, running obliquely forward 

 and inward from the tip of the paroccipital to the apex of the hyoid cornu. This inser- 

 tion, however, is only partial ; some fibres are continuous with the constrictor of the 

 pharynx, and seem to represent the stylo-pharyngeus of anthropotomy. Other muscles 

 of the palate and pharynx do not fidl within the scope of the present memoir. 



Sterno-hyoideus. — A straight cylinder, somewhat flattened, lying along the median line, 

 upon the sterno-thyroid, in apposition with its fellow. Instead of arising from the top of 

 the sternum, it takes flesliy origin from the inner surface of the latter, from the body of 

 the second sterneber, in conjunction Avith the (single) sterno-thyroid. It is inserted on 

 either side of the median line, into the lower border of the hyoid. It occasionally gives 

 off, near the middle of its course, a delicate fasciculus that is inserted into the lower 

 outer angle of the thyroid cartilage. 



Sterno-thyroideus. — This pair of muscles presents the peculiarity of arising azygos, 

 afterwards bifurcating a little above the top of the sternum. The common muscle of origin 

 takes rise from the body of the second sterneber, on the inner surfirce of the bone, 

 bounded on either side by the sterno-hyoid, and usually blended with the latter, and ter- 

 minates in a horse-shoe shaped tendinous constriction, from the sides of which its separate 

 portions commence. These lie directly upon the trachea, covered by the preceding pair 

 of muscles, and pass, as flattened bands of moderate width, to be inserted fleshy into the 

 lower edge of the thyroid, on either side of the median line. A few slender fasciculi are 

 sometimes sent up to join the hyoid bone. The fibrous constriction is sometimes wanting ; 

 then the two parts arise by simple forking of the common muscle of origin. The place 

 of bifurcation is also variable ; but I have always found it above the sternum, and have 

 not found that the muscle ever arises double. 



Thyro-hyoideus. — This is not simply a direct upward prolongation of the preceding, 

 but perfectly distinct and moreover oblique in direction. It is a short, broad plane, 



