THE SESAMOID ARTICULAR 9 



easily separated. The inner part thus separated may represent A~3 of 

 Vetter, and the outer part A-2. 



The upper part of the sheet of tendon is free from the muscle and 

 at its anterior end helps to form the maxillary tendon. Continuous with 

 this sheet of tendon is the tendinous covering of the inferior part of the 

 adductor mandibulae, or the part confined to the mandible (A-co of 

 Vetter), which posteriorly sends back a bundle of fibers to the middle 

 of the quadrate. Dissecting this tendinous covering away a stout sesa- 

 moid articular tendon is found, which comes from the lower part of the 

 sheet of tendon, or the part covering the ventral muscle (A-2+3). 

 Attached to the articular below the sesamoid articular and below Meckel's 

 cartilage is a less compact bundle of tendinous fibers from the same source. 

 Crossing these two, and attached still lower on the articular, is another 

 bundle of fibers coming more directly from the upper part of the sheet 

 of tendon, or the part covering the dorsal muscle (A-i). 



The levator arcus palatini muscle is very small, and no part of the 

 adductor mandibulae runs behind it. 



, Tylosurus acus. 



The superior portion of the adductor mandibulae is in two parts: 

 (i) An external part that is ventral to the internal muscle, instead of 

 dorsal to it as in Scorpaena. It originates on the preopercle and covers 

 a considerable portion of the levator arcus palatini and of the internal 



L <vp. 



so. 



Al 



Fig- 3- TYLOSURUS ACUS 

 A 1-2-3, muscles of Vetter; Lap, levator arcus palatini; sa, sesamoid articular. 



muscle. Its tendinous surface fibers on its lower part converge and are 

 joined directly to the sesamoid articular, while those of the upper part 

 are attached to the tendon which descends from the dorsal internal 

 muscle and borders its anterior edge. (2) The portion referred to 

 above as the dorsal internal muscle has its origin on the anterior edge of. 

 the hyomandibular and the surface of the metapterygoid. Posteriorly 



