Nos. IAND2.] ANATOMY OF SCOMBER SCOMBER. 259 



ulse. Near the distal end of that muscle it issues between it and 

 the deeper division of the adductor, and comes to the exposed 

 outer surface of the latter muscle near the hind end of the mandi- 

 ble. There it describes a short curve, turning upward and for- 

 ward along the lower edge of the superficial division of the 

 adductor, near its insertion, and passes mesial to the hind edge of 

 the articular, near its dorsal end. There it turns downward and 

 forward, and lying internal to the articular, along the lateral sur- 

 face of the mandibular part of the adductor mandibulae, reaches 

 the dorsal surface of Meckel's cartilage. There it turns directly 

 forward, along the dorsal surface of the cartilage, and lying inter- 

 nal to the dentary continues its forward course toward the anterior 

 end of the mandible. 



What is probably the first branch of the nerve is given off from 

 the truncus maxillaris as it issues from the trigeminal opening of 

 the trigemino-facial chamber. Turning backw^ard and upward, 

 close against the lateral surface of the skull, it sends two branches 

 to the levator arcus palatini, and then enters and innervates the 

 dilatator operculi. It is accordingly the exact homologue of the 

 first branch of the corresponding nerve in Aiitia. 



Not far from this first branch of the nerve the communicating 

 branch from the truncus maxillaris to the buccalis facialis is given 

 ofif. This branch thus corresponds, in the order of its origin from 

 the truncus, but in nothing else, so far as is evident, to the large 

 branch sent in Aniia to the levator maxillge superioris. Some- 

 what further forward the truncus maxillaris separates into its 

 superior and inferior portions. 



The third branch of the inferior nerve is given off after it has 

 separated from the superior one. It leaves the nerve approxi- 

 mately at the anterior edge of the levator arcus palatini, and sepa- 

 rates at once into two parts, each part often appearing as a 

 separate and distinct nerve. Running backward and downward 

 between the superficial and deeper divisions of the adductor 

 mandibulse, each part or division of the nerve breaks up into two 

 or more branches, all of which enter the two divisions of the ad- 

 ductor, which they innervate. This branch of Scomber is accord- 

 ingly the homologue of the third branch of the nerve in Aiiiia. 



The next, or fourth, branch of the nerve is given off from that 



