580 DE. J. MUEIE OX THE ANATOMY OP THE SEA-LION. 



G.h. Geniohyoid. 



S.g. Stylo-glossus. 



si. Superior laryngeal nerve and artery. 



/. Lingual artery and hypoglossal nerve. 



g. Gustatory nerve. 



M.h. Mylo-hyoid. 

 O.h. Omo-hyoid. 

 S.h. Stern o-hyoid. 

 S.th. Sterno-thyroid. 

 C.th. Crico-thyroid. 

 Th.h. Thyro-hyoid. 



T.gl, thyroid gland ; Sgl, sublingual gland and duct. 

 Fig. 54. Side view, deep dissection, of the same regions as in fig. 53, but enlarged. 

 The lettering agrees, but there is in addition: — Ghg, genio-hyoglossus ; Thy, 

 thyroideus ; Ic, inferior constrictor ; Mc, middle constrictor ; Sjih, stylo- 

 pharyngeus ; Hg, hyoglossus ; oe, oesophagus ; v, jugular vein ; ca, common 

 carotid artery, dividing anteriorly into internal and external carotids, with 

 subsidiary branches ; pn, pneumogastric nerve, superior laryngeal, pharyngeal, 

 and lingual derivatives springing and being distributed anteriorly. 

 Fig. 55. Upper view of the pharyngeal constrictors and the adjoining parts : il, inferior 

 laryngeal nerve ; Sc, superior constrictor, in part ; Azu, azygos uvulae unco- 

 vered on one side ; Pp, palato-pharyngeus ; arrow leads into pharynx. Other 

 letters apply as in preceding (fig. 54) and succeeding (fig. 50), in which latter 

 portions of muscles have been removed. 

 Fig. 56. A deeply dissected side view of the same region as in fig. 55. He, hyo-epiglottic. 

 Fig. 57. Epiglottis and laryngeal fissure, with part of the pharyngeal membrane of the 

 left side, reflected outwards. Seen from above, and somewhat less than 

 natural dimensions : Ep, epiglottis ; sp, fatty prominences, or Santorinian 

 projections ; ae , aryteno-epiglottic folds ; p, papilla? of the postfaucial floor ; 

 a, arytenoid prominences ; ph, pharyngeal cavity. 

 Fig. 58. Seduced diagrams illustrating the outline of the superior aperture of the 

 larynx in three different states of tension : 1, its natural condition ; 2, slightly 

 open, or during inhalation (?) ; 3, fully distended. The black ground marks 

 the longitudinal chink, the light the divaricating loops. 

 Fi<*. 59. The interior left half of the larynx as displayed by a mesial longitudinal section 

 through the entire organ, but retaining the epiglottis intact : ep, epiglottis ; 

 s.p, fatty projections above the cartilage of Santorini ; T, T*, sections of 

 the thyroid cartilage, the smaller portion being the narrow bridge anteriorly 

 connecting the thyroid alae ; C, cricoid, in front and behind ; tr, trachea ; 

 s, orifice of laryngeal sac. 

 Fig. 60. The deep lateral thyro-arytenoid muscles &c. The dotted outline signifies the 

 boundary of the right thyroid ala, which has been removed. L.c.a, lateral 

 crico-arytenoid ; P.c.a, posterior crico-arytenoid ; At; arytenoideus ; Th.a\ 

 thyro-arytenoideus, its first or lower portion ; Th.a 2 , second or upper portion 

 of the thyro-arytenoideus ; s, laryngeal sac or pouch ; ep, epiglottis. 



