374 



of the raouth or subdivides into a R. mandibularis externus to the skin 

 and mucous canals, and a R. mandibularis internus to the mucous 

 membrane of the mouth." 



Strong's interpretation of Stannius' statements, and my own, are 

 thus both markedly different from Cole's. 



As to the other authors definitely cited by Cole in support of his 

 assertions, Jackson and Clarke's work on Echinorhinus is not at my 

 disposal. In Pinkus' work on Protopterus (No. 17), that author first 

 describes, on p. 304 and 305, a branch, No. 2, of the facialis, which 

 "entspricht seiner Lage nach einem P. hyoideus". He then says of a 

 branch of the fourth branch of the facialis, described under the heading 

 "Der Verbindungsast mit dem P. maxillae inferioris": „Der Nerv ent- 

 spricht dem P. mandibularis internus". 



Here the mandibularis internus is clearly simply a branch of the 

 postbranchial portion of the facial, it is described as co-existent with 

 a ramus hyoideus, and the distribution ascribed to it indicates that it 

 is wholly sensory. And yet Cole says of Pinkus (No. 5, p. 659), "he 

 also identifies correctly the mandibularis internus (which is a motor 

 nerve in Protopterus as in Chimaera)". 



Among other investigators who have described the facialis in fishes, 

 but whose works are not definitely mentioned by Cole in this connec- 

 tion, I will cite but one, van Wuhe, my use of the terms here con- 

 cerned having been based upon his use of them. That author, in his 

 memoir on the cranial nerves of Ganoids (No. 27), says of all the fishes 

 there described by him, that the postbranchial division of the facialis 

 separates into a ramus hyoideus facialis and a ramus mandibularis fa- 

 cialis, and that the latter nerve in all, excepting only Acipenser, then 

 separates into a ramus mandibularis externus and a ramus mandibularis 

 internus. A ramus mandibularis externus facialis he did not find in 

 Acipenser. 



Platt says (No. 18, p. 533 — 534), that the ramus hyoideus of 

 these determinations of van Wijue is, in Necturus, simply a lateral 

 branch of a nerve called by her the hyomandibularis, this latter nerve 

 being said by her to be the homologue of van Wijhe's ramus mandi- 

 bularis. The ventral continuation of her hyomandibularis is called by 

 her the internal mandibular, and the internal mandibular of Strong is 

 said to probably correspond to a nerve called by her the external 

 palatine. The internal mandibular of fishes may, therefore, not be the 

 homologue of the similarly named nerve in higher vertebrates, and 

 hence the confusion. My acquaintance with the literature relating to 

 these latter animals is too limited to allow me to venture an opinion. 



Leaving aside now the question of the correctness or incorrectness 

 of my momenclature, is the nerve described by me in Amia as the 

 mandibularis internus facialis a prespiracular or a postspiracular one ? 

 Cole says of it (p. 200) : "The fact is, nothing is known of the relation 

 of the 'internal mandibular' nerve of Amia to the spiracular cleft, since 

 the embryonic condition has not yet been worked out, and the cleft 

 itself degenerates in the adult." To say that nothing is known of 

 the relation of the nerve to the cleft is a somewhat singular statement, 



