264 ALUS. - [Vol. XVIII. 



p. 167), it is the trigeminal part of the nerve, and not the facial 

 part, that innervates the muscle. 



This terminal part of this large branch of the maxillaris infe- 

 rior of Scomber thus seems to represent the two branches called 

 by me in my descriptions of Amiaj. gJis and r. gJii, and it can for 

 convenience be designated as r.gh. It corresponds, apparently, to 

 that branch of the trigeminus that is called by Ruge (No. 

 63, p. 269) the nervus mylo-hyoideus, and that is said by 

 him to be a "portio facialis des Ram. III. trigemini." In Cera- 

 todiis this nerve is said by Ruge to contain motor elements destined 

 to innervate, in part, the muscle Coinz', that muscle also receiving 

 branches directly from the ramus hyoideus facialis ; certain of the 

 branches of the latter nerve forming an anastomosis with 

 branches of the former. In P rot opt ems that branch of the tri- 

 geminus that corresponds to the nervus mylo-hyoideus of Ccrato- 

 diis is said to take no part in the innervation of the muscle Coiiiv, 

 that muscle being innervated wholly by branches that come 

 directly from the ramus hyoideus facialis (No. 63, p. 281). The 

 muscle Cjnv, in each of these fishes, is said by Ruge to be derived, 

 unquestionably, from the muscle similarly designated by him in 

 selachians, and the muscle, in these latter fishes, is said to be a 

 part of the facialis group of muscles. The apparent innervation 

 of the muscle by a branch of the trigeminus, in Ceratodus, is then 

 accounted for by the supposition that the motor fibers in the r. 

 mylo-hoideus of that fish are in reality a part of the facialis, and 

 have become associated secondarily with the nervus trigeminus. 



The muscles Cn;inv of Ceratodus and Protopteriis would seem, 

 unquestionably, to include fibers that represent, in those fishes, 

 the inferior part of the geniohyoideus of Aniia, which muscle I 

 was led (No. 4, p. 582), under considerable reserve, to derive 

 from the ventral half of the superficial constrictor of the mandibu- 

 lar arch, and not from that of the hyoid arch. Ruge's positive 

 assertion that that branch of the trigeminus that is distributed to 

 this muscle in Ceratodus contains motor fibers, and Herrick's state- 

 ment, already referred to, that, in Menidia, it is the trigeminus and 

 not the facialis that innervates the geniohyoideus seem to confirm- 

 this conclusion; as does also Cole's statement (No. 15) that in 

 Chhnccra certain long branches of the mandibularis trigemini go 



