THE CHORDA TYMPANI. 167 



the mucous covering of the upper end of the hyoid arch is 

 supplied from the r. mandibularis internus VII (my branch 

 m. VII. j), i.e., from the post-spiracular VII. Such fibres 

 do occur in the r. mandibularis V of Amia and accord- 

 ingly we find the taste buds and mucosa of the corre- 

 sponding region supplied by the fourth branch of the 

 mandibularis V ('97, p. 612), Allis is, doubtless, correct 

 in homologizing these fibres with the chorda tympani, 

 i. e., they correspond to Stannius' branch 2 of selachians. 

 The r. pre-trematicus scnsu stricto (branch i) may also be 

 represented in this nerve, but more probably in the 

 " posterior palatine " of Allis (see below). 



Goronowitsch ('96) has also described, though wnthout recognizing 

 their significance, similar fibres from the geniculate ganglion to the 

 r. mandibularis V in Lota vulgaris. This I can confirm (July, 1899) 

 in Gadus morrhua, and can add that here, as in Amia, the mucosa of 

 the hyoid region is supplied by these mandibular fibres, and not by 

 the r. mandibularis internus VII. 



I would suggest that in Menidia the independence of 

 the r. pre-trematicus VII is to be accounted for by the 

 great size of the pseudobranch, which is innervated by this 

 nerv^e. Not having fused with the r. mandibularis V, the 

 pre-trematic VII is distributed only to the area about the 

 pseudobranch; and the regions farther cephalad, along 

 the hyoid and mandibular arches, which are supplied by 

 other pre-trematic fibres in some other forms, in Menidia 

 are supplied by the post-trematic branch. Menidia 

 clearly lacks the chorda in the proper sense of that term, 

 the post-trematic communis element replacing it func- 

 tionally. 



I am inclined, therefore, to regard the nerve to be de- 

 scribed beyond as the r. pre-trematicus VII of Menidia as 

 the equivalent of Stannius' branch i of selachians. It is not 

 properly the homologue of the chorda tympani of mam- 



