MUSCULAR SYSTEM 145 



l>e also added a sterno-thyroid, from which a thyro-hyoid is con- 

 tinued forwards. 



The stylo-hyoid, stylo-glossus, and stylo-pharyngeus of Mam- 

 mals, arising from the styloid process and stylo-hyoid ligament and 

 undergoing numerous variations, are peculiar to Mammals. They 

 are supplied partly by the facial nerve, partly by the glossopharyn- 

 geal, and act as retractors of the tongue and levators of the pharynx 

 and hyoid. 



The muscles of the jaws resemble those of Amphibia, although, 

 especially in the case, of the pterygoids, 1 they are much more 

 sharply differentiated, and are throughout more strongly developed. 



1 For the tensor tympani and stapedius muscules, see under Auditory Organ. 



