10 



THE SESAMOID ARTICULAR 



it is covered by the levator arcus palatini. It sends down a stout tendon 

 bordering the posterior orbital margin, and the anterior edge of the 

 ventral muscle as described, and joins the sesamoid articular. As neither 

 of these muscles sends a tendon to the maxillary, and as each contributes 

 to the sesamoid articular, the homologies of the two parts are not very 

 clear. From their relation with the levator arcus palatini the outer ven- 

 tral muscle would seem to represent A-i of Vetter, and the dorsal inner 

 muscle A-2 (+3?). 



Mugil cephalus. 



The superior part of the adductor mandibulae muscle consists of 

 three parts: (i) A lower outer muscle which originates on the pre- 

 opercular ridge and is connected by a stout tendon to the maxillary (A-i 

 of Vetter). (2) A muscle situated above and partly under the first origi- 

 nates higher on the preopercular ridge, and lies outside of the levator 

 arcus palatini muscle (A-2 of Vetter). (3) The third is almost wholly 



Fig. 4. MUGIL CEPHALUS 

 A t-z-S, muscles of Vetter; Lap, levator arcus palatini; max, maxillary. 



covered by the second, its posterior end lying under the levator arcus 

 palatini, and originating on the surface of the metapterygoid. The 

 second and third unite anteriorly in a stout sesamoid articular tendon. 

 The inferior, or mandibular part of the muscle (A-co of Vetter), which 

 is almost confined to the mandible, consists of two parts. The upper 

 part gives off a broad band of tendon which connects it with the front of 

 the quadrate, and it also sends a few fibers to join the sesamoid articular 



