114 NERVE COMPONENTS OF BONY FISHES. 



cular ramus of the vagus as innervating the opercular 

 muscles. 



The fourth branch of the the r. opercularis vagi 

 {pp. X. 4), composed of very fine fibres, passes directly 

 ventrad after separating from the third branch and joins 

 the third branch of the r. opercularis superficialis VII 

 (pp. s. VII. j) just above the dorsal edge of the opercular 

 bone. The combined trunk now passes down the inner 

 face of that bone and supplies the mucous membrane of 

 the dorsal part of the lining of the operculum. 



Baudelot ('83, p. 132) says of this nerve in the carp: 

 ^'- Quant a la tranche operculaire dii pneumogastrique, elle 

 descend jiisqii' ail bord infc'rieur dc Vopercnle en e^ivoyant 

 sur son trajet des filets a la peau : il est possible qiC elle 

 s' anastomose a sa terminaison avec la branche operculaire 

 super ficielle'''' [VII]. 



Guitel ('91) finds in Lophius that this nerve anastomoses 

 with both the superficial and the deep opercular rami of 

 the facial, and that the nerve for the mucous lining of the 

 branchiostegal membrane comes from the latter anasto- 

 mosis, instead of the former, as I find it in Menidia. 



These cutaneous vagal fibres are of special interest. 

 Their true relations seem not to have been clearly recog- 

 nized by any of the older writers. Shore ('89) found in 

 Raja a cutaneous branch in this position which he calls r. 

 auricularis and regards as general cutaneous. Neverthe- 

 less it is not quite clear from his description (especially as 

 he describes it as coarse fibred) that this may not be the r. 

 supratemporalis vagi (lateralis fibres), which Ewart and 

 Mitchell ('91) describe as arising in about the same 

 position. It is probable that his cutaneous ramus contains 

 both of these elements, as in Raja there is no r. supratem- 

 poralis IX for the canal organs (Stannius, p. 79, Ewart 

 and Mitchell, '91). 



Strong was the first to contrast clearl)'- the r. supratem- 

 poralis (a lateral line nerve) and the r. cutaneous dorsalis 



