EEPORT ON THE SPHENISCID^. 135 



Action.— This muscle co-operates with the next in protracting the hyoid bone and 

 tongue. 



Relations. — The cerato-transverse muscle rests against the mylo-hyoid muscle. 

 Nerve supply (?) 



3. Protractor lingnce. 



Kegelfijriniger Kiefer-Zungenheinmuskel, Tiedemann, p. 121, No. 3. 



Voneclrtszieher der Zunge, "Wiedemann, p. 71. 

 Muscle conique, Vicq d'Azyr, 1773, p. 585, No. 3. 



Genio-hyo'idien, Cuvier, vol. iii. p. 246, No. 3. 



Protracteur ou Tnylo-hydidien profond, Meckel, vol. viii. p. 176, No. 3. 



Protradeur de I'hyhoide [genio-hyuidien), Gervais and Alix, p. 1 8. 



Attachments. — This, the third muscle derived from the muscular sheath enveloping 

 the cornu of the hyoid bone, passes obliquely forwards and outwards, and is inserted into 

 the inner surface of the ramus of the lower jaw, midway between the junction of the 

 latter with its fellow of the opposite side and its articulation with the quadrate bone. 



Action. — Taking its fixed point at the lower jaw, this muscle draws forwards the 

 hyoid bone and tongue. 



Relations. — The protractor arises along with the two preceding muscles from the 

 cornu of the hyoid bone. As it passes forwards to its insertion it is crossed superficially 

 by the retractor linguae. 



Nerve supply (?) 



4. Retractor linguce. 



Milo-hyo'idien, Vicq d'Azyr, 1773, p. 585, No. 2. 

 Serpi-hyo'idien, Cuvier, vol. iii. p. 246, No. 2. 

 Ruckwartszieher der Zunge, Wiedemann, p. 71. 

 ScMefer Kie/erzungenbeinmuskel, Tiedemann, p. 120, No. 2. 

 L'elevatetir de I'os hydide, Meckel, vol. viii. p. 174, No. 1. 

 Retracteur de I'hydide ou serpi-hyaidien, Gervais and Alix, p. 18. 



Attachments. — The retractor linguae is a riband-like muscle, which arises from a 

 well-marked process (serpiform process) situated on the posterior or articular extremity 

 of the lower jaw bone. The fibres pass obliquely forwards and inwards, and after 

 crossing the superficial aspect of the protractor linguae, are inserted chiefly into the 

 anterior third of the apo-hyal element, and to a less extent into the uro-hyal cartilage. 



Action. — This is the principal retractor of the hyoid bone and tongue. 



Nerve su'pply (?) 



