178 NERVE COMPONENTS OF BONY FISHES. 



the cephalic one conforms closely to the typical arrange- 

 ment as given by Stannius (p. 47). This latter nerve was 

 found by Stannius in all of the fishes examined by him, 

 with the exception of Amiurus and those in which the VII 

 emerges from the same foramen as the V. In Belone he 

 found it to be composed chiefly of coarse fibres, with a 

 smaller number of fine ones. I find, however, that both 

 rami communicantes are composed exclusively of very 

 fine fibres, though by analogy with other general cutane- 

 ous nerves I should have expected a few coarse ones to 

 be mingled with them, and more especially as in some 

 pure cutaneous ramuli of the r. hyoideus, which must be 

 derived from these rami communicantes, there are 

 numerous coarse and medium fibres. This case is typical 

 of many others which lead me to believe that the calibre 

 of individual fibres may vary widely in different parts of 

 their courses. 



The motor V fibres run under the Gasserian ganglion 

 and after their emergence take a position on the caudal 

 and inner side of the infra-orbital trunk. The acustico- 

 lateralis component arises from the dorsal lateralis gan- 

 glion and its fibres pass out on the cephalic and lateral face 

 of the trunk. The communis fibres from the geniculate 

 ganglion which have not been given off intra-cranially are 

 somewhat confused with the general cutaneous from the 

 Gasserian ganglion. A part of these fibres go out with 

 the roots of the r. lateralis accessorius, others go out with 

 the supra-orbital trunk, but the larger part is clearly seen 

 to enter the infra-orbital trunk. 



The four nerves which are represented in the infra- 

 orbital trunk are so confused, even in their smaller 

 branches, that they cannot well be described separately. 

 I shall, therefore, describe the branches of the trunk in 



