MUSCLES OF MASTICATION — HYOID MUSCLES 



297 



MUSCLES OF MASTICATION " 



The masseter is not so large as in the horse; a considerable part of it arises 

 on the facial tulxn-osity and is directed ol)li(]uely backward and downward, so that 

 it would draw the lower jaw forward as well as upward. 



The temporalis conforms to the temporal fossa, and is therefore longer and 

 entirely lateral in position. 



The pterygoidei are not quite clearly separated; their direction is more 

 oblique, antl the origin of the pterygoideus internus is nearer the median plane 

 than in the horse. 



Fio. 208. — Muscles of Head of Ox, Dorsal View. 

 a, a', Levator labii superioris proprius; b, levator uasolabialis; /, dilatator naris lateralis; g', malaris; o, zygo- 

 matieo-auricularis and scutulo-auricularis superficialis inferior; o", t-cutulo-auricularis superficialis superior; o'", 

 scutulo-auricularis superficialis accessorius; p, scutularis; ;/, frontalis; z, orbicularis oculi; i , concave surface of 

 concha; 3, 2, anterior and posterior borders of concha; 8, scutiform cartilage; ^4. parietal cartilage; S9, facial 

 vein; J,9, muzzle; oS, internal paljjebral ligament. (After Ellenberger-Baum, Anat. fiir Kunstler.) 



The stylo-mandibularis is absent. 



The digastricus has a tendinous origin on the paramastoid or styloid process 

 of the occipital bone; its bellies are short and thick. It does not perforate the 

 stylo-hyoideus. The two digastrici are connected beneath the root of the tongue 

 by a layer of transverse muscle-fibers (Transversus mandibulae). 



HYOID MUSCLES 

 The mylo-hyoideus is thicker and more extensive than in the horse. 

 The stylo-hyoideus has a long thin tendinous origin and is not perforated by 

 the digastricus. 



