MUSCLES OF THE PHARYNX (Fig. 96).--=M. glossopharyngeus= (_i_). _Origin._--Some fibres on the ventral and lateral part of the genioglossus (_f_) leave that muscle near its caudal end. They form a thin band of diverging fibres which pass outside of the cranial horn of the hyoid. A similar sheet of fibres leaves the midventral part of the styloglossus (_e_). The two sheets unite and the united muscle crosses the hyoid, turns dorsad, and has its _Insertion_ into the median dorsal raphe of the pharynx. _Action._--Constrictor of the pharynx. =M. constrictor pharyngis inferior= (_k_).--A thin sheet of muscle covering the sides of the pharynx at its caudal end. _Origin_ from the lateral surfaces of the thyroid and the cricoid cartilages. The fibres pass dorsad and craniad, the cranial ones covering the fibres of the middle constrictor (_j_). _Insertion._--The median longitudinal raphe on the dorsum of the pharynx. The caudal fibres are transverse and continuous with the circular fibres of the œsophagus. The cranial fibres may pass as far as the base of the sphenoid. _Action._--Constrictor of the pharynx. =M. constrictor pharyngis medius= (_j_).--A thin sheet which covers the middle part of the lateral surface of the pharynx. _Origin._--The ventral two pieces of the cranial horn and the whole of the caudal horn of the hyoid. The fibres diverge, passing dorsad. _Insertion_ into the median dorsal raphe of the pharynx. The cranial fibres are inserted into the base of the sphenoid bone. The muscle covers part of the stylopharyngeus (_l_) and the superior constrictor (Fig. 66, _f_, page 112) and is partly covered by the glossopharyngeus (Fig. 96, _i_). _Action._--Constrictor of the pharynx. =M. stylopharyngeus= (_l_). _Origin_ from the tip of the mastoid process of the temporal bone and from the inner surface of the cartilaginous piece between the tympanohyal and the stylohyal bones. The parallel fibres form a flat band which passes ventrocaudad over the outer surface of the constrictor superior. _Insertion._--The ventral fibres pass beneath the middle constrictor (_j_) at its cranial border and, continuing toward the middle line of the pharynx, gradually lose themselves among the fibres of the superior constrictor. The dorsal fibres pass onto the outer surface of the middle constrictor and are lost among its fibres. _Action._--Constrictor of the pharynx. =M. constrictor pharyngis superior= or =pterygopharyngeus= (Fig. 66, _f_, page 112).--A flat, triangular sheet beneath the constrictor medius. _Origin._--The tip of the hamular process of the pterygoid bone. The muscle passes caudad, the fibres diverging, and dips beneath the cranial border of the constrictor medius.