The =sterno-thyro-hyoideus= is described on p. 226.
The =thyro-hyoideus= (M. hyo-thyreoideus) is a flat, quadrilateral
muscle, which lies on the outer surface of the thyroid lamina and the
lateral part of the thyro-hyoid membrane. It arises from the thyroid
cornu of the hyoid bone, and ends on the oblique line on the lamina of
the thyroid cartilage. Its action is to draw the larynx toward the root
of the tongue.
The =hyo-epiglotticus= (M. hyo-epiglotticus) is a feeble muscle which
occupies a median position above the central part of the thyro-hyoid
membrane, inclosed by an elastic sheath, the hyo-epiglottic ligament. It
arises from the body of the hyoid bone by two branches which unite and
are inserted into the front of the base of the epiglottis. Its action is
to draw the epiglottis toward the root of the tongue.
[Illustration:
FIG. 354.—LARYNGEAL MUSCLES OF HORSE, SEEN FROM LEFT SIDE AFTER
REMOVAL OF MAJOR PART OF LAMINA OF THYROID CARTILAGE.
_a_, Kerato-hyoideus; _b_, thyro-hyoideus; _c_, crico-thyroideus; _d_,
sterno-thyroideus; _e_, ventricularis; _f_, vocalis; _g_,
crico-arytenoideus lateralis; _h_, crico-arytenoideus post. _s_,
dorsalis; _i_, arytenoideus transversus; _1_, lingual process; _2_,
small cornu; _3_, thyroid cornu, of hyoid bone; _4_, thyroid
cartilage; _5_, cricoid cartilage; _6_, epiglottis; _7_, apex of
arytenoid cartilage; _8_, trachea; _9_, muscular process of
arytenoid; _10_, lateral lobe of thyroid gland; _10′_, isthmus of
thyroid gland; _11_, laryngeal saccule. (Ellenberger-Baum, Anat. d.
Haustiere.)
]