13(3 THE VOYAGE OF H.M.S. CHALLENGEE. 



5. Transverse hyoid muscle. 



Muscle No. 7, Owen (Cyclopedia of Anatomy), voL i. p. 316. 

 Hyo-glosse transverse, Cuvier, voL iii. p. 269, No. 2. 

 Releveur de la langue, Jleckel, vol. viii. p. 173, No. 2. 

 Hyo'idien transverse, Gervais and Alix, p. 18. 



Attachments. — This muscle is composed of a single bundle of transversely arranged 

 muscular fibres, wbich stretch across the lower surface of the hyoid bone, immediately in 

 front of the articulation of the apo-hyals with the basi-hyal element. Its fibres are in 

 part inserted into the lateral borders of the base of the glosso-hyal cartilage, and in part 

 into those of the basi-hyal bone. 



Action. — In contracting, this muscle arches the dorsal surface of the tongue and 

 depresses the tip of that organ. It thereby renders prominent the large papillae which 

 invest the dorsal surface of the tongue. 



Nerve supply (?) 



6. Mylo-liyoid muscle. 



Genio-hyaidten, Vicq d'Azyr, 1773, p. 585, No. 1. 



Der raufenfdrmi'ge Kehlmuskel, Wiedemann, p. 70. 



Quer-Kiefer-Zungenheinmuskd, Tiedemann, p. 120, No. 1. 



Mylo-hydidien, Cuvier, vol. iii. p. 245, No. 1. 



Muscle transverse de la machoire inferieure, Meckel, vol. viii. p. 175, No. 2. 



Mylo-hyoidien, Gervais and Alix, p. 19. 



Attachments. — The mylo-hyoid muscle consists of a number of muscular fibres, which 

 fill up the interval between the rami of the lower jaw, to both of which they are attached 

 posteriorly to the symphysis. A few of the posterior fibres extend beyond the rami of 

 the lower jaw, and are attached to the zygomatic arch of each side. 



Action. — This muscle elevates the hyoid bone and tongue. 



Relations. — The mjdo-hyoid muscles of opposite sides form, as it were, a floor upon 

 which the hyoid bone and its muscles already described rest. Posteriorly its fibres are 

 in series with the circular fibres of the cutaneous muscle of the neck. It takes no attach- 

 ment to the hyoid bone. 



Nerve supply (?) 



7. Thyro-hyoid muscle. 



Thyro-hydidlen, Vicq d'Azyr, 1773, p. 581, No. 2. 

 KeKlknpf-Zungenbeimmiskd, Tiedemann, p. 122, No. 5. 

 Thyro-hydidien, Gervais and Alix, p. 18. 



Attachments. — This muscle may be regarded as a continuation forwards of the contractor 

 tracheae muscle. It arises from the lower as well as from the lateral surface of the thyroid 



