JAW MUSCLES 



25 



upper border of the jugal and to the lower edge of the temporal 

 fossa in the post-glenoid region. The temporalis is formed chiefly 

 by a great fan of fleshy fibres which arise from the floor of the 

 temporal fossa ; the more superficial fibres take origin from the 



Fig. 14. — Arvicola amphibius Linnaeus. 

 Jaw muscles (continued) : letters as in Fig. 13. 



under surface of the temporal fascia. The fibres converge to 

 their insertion into the tip and inner face of the coronoid process. 

 The anterior and central portions of the muscle are particularly 

 strong ; and some of the deeper fibres arising from the squamosal 

 upon the anterior shoulder of the braincase have a tendinous origin, 

 the tendon producing the post-orbital crest or process of the 

 squamosal which is so characteristic of the subfamily. 



