Nos. IAND2.] ANATOMY OF SCOMBER SCOMBER. 191 



of them having- any other insertion whatever, though some of them, 

 along the postero-ventral edge of the muscle, join and are con- 

 tinuous with fibers of the muscle AnA^. The anterior and super- 

 ficial tendon that arises from the tendinous band separates at once 

 into two parts. One of these parts (t. a.^ la) is short and broad, 

 and triangular in shape, runs forward and downward along 

 the inner surface of the lachrymal, and is inserted along the 

 lower edge of the posterior third of that bone. It lies between 

 the lachrymal bone and the crease or fold of the external skin 

 that extends upward between the lachrymal and the maxillary. 

 The other and smaller part of the anterior and superficial tendon 

 runs downward and backward, and is inserted on the outer sur- 

 face of the articular, near its hind end. The posterior and deeper 

 tendon of the muscle runs downward and forward, and joins a 

 tendon that may be called tendon A^A^, joining that tendon at the 

 point where it joins a tendon or fascia on the inner surface of A^. 

 The muscle, along its postero-ventral edge, is partly continuous 

 with AzA^, as stated above. 



A^As, the deeper portion of the adductor, lies partly internal 

 to and partly postero-ventral to A^^. It is single at its origin but 

 double at its insertion, and is apparently formed by the almost 

 complete fusion of the two muscles called by Vetter (No. 75) 

 A2 and A, in the fishes described by him. It arises from the an- 

 terior edge of the preoperculum, along something- more than its 

 middle third, from the outer surfaces of the hyomandibular 

 and metapterygoid, and from the dorsal end of the quadrate, its 

 surfaces of origin on these latter three bones lying immediately 

 in front of the preoperculum. On its outer surface there are two 

 strong tendinous lines, partly oblique and partly longitudinal in 

 position. They mark the outer edges of two aponeurotic forma- 

 tions .which extend inward, downward, and backward into 

 the muscle. The posterior one of these two aponeuroses lies 

 ventral to the other one, is short, and the fibers arising from 

 its antero-internal surface are inserted on the outer surface of the 

 other aponeurosis. Neither of the two formations extends through 

 the muscle to its inner surface. 



Toward its insertion the muscle A^A^ separates partly into two 

 parts, as already stated, and I accordingly call them A^ and A^, 



