1895.] SETfSORT CAT!f AL SYSTEM OF FISHES. 295 



1. The ramus ophthalmicus superjicialis is the first branch pass- 

 ing from the G-asserian ganglion. It is covered for a part of its 

 course by the branches of the olfactory nerve. It arises from the 

 ventral side of the Gasserian ganglion and gives off a series of fine 

 branches, which innervate the supra-orbital branch of the main 

 sensory canal (PI. XXI. figs. 16, 17). 



2. The ramus buccalis innervates the anterior portion of the 

 sub-orbital branch of the main sensory canal. Its distribution is 

 somewhat different from that figured and described in Esox. It 

 divides posterior to the orbit into two branches, both of which pass 

 forwards to the region of the snout. In Esox this division takes 

 place anterior to the orbit. 



3. 2'he ramus maxillaris together with the ramus mandibularis 

 forms the main branch of the trigeminal nerve. It passes forwards 

 and downward towards the orbit, on the border of which it divides, 

 sending a branch (PI. XXI. figs. 16, 17 r.mx.^) to the posterior and 

 inferior portions of the sub-orbital branch of the main sensory 

 canal ; this again divides, forming the branch »\?)i.r.2 (fig. 17) which 

 innervates the saccular dilatation number 4. TJie ramus mandi- 

 bularis does not innervate any portion of the canal system. 



4. TJie ramus oticus innervates the whole of the main canal of 

 the head. It consists of two main divisions, which further divide 

 into numerous fine twigs. 



The Facial nerve innervates the terminal portion of the lateral 

 canal and the operculo-mandibular branch of the main canal. The 

 chief division, represented in Esox by the ramus hyomandibularis 

 (PI. XX. figs. 10, 11, r.hy.), is somewhat different in Conger 

 (PI. XXI. figs. 16, 17, rJiy.). Below the lateral border of the 

 frontal bone, and upon the upper portion of the hyomandibular 

 bone, it divides into two main branches ; the smaller (fig. 17, r.op.) 

 passes posteriorly beneath the opercular portion of the sensory 

 canal. Its main branch is continued backwards for some little 

 distance and innervates a large sensory organ in the saccular 

 dilatation number 1, and the last sensory organ in the lateral canal. 

 The two smaller divisions do not innervate any portion of the 

 canal system. 



The larger branch, the ramus hyomandibularis (fig. 20, r.hy.rm.), 

 passes along the side of the operculo-mandibular branch of the 

 main sensory canal and divides into a mandibular and hyoidean 

 branch. Branches from the former pass to the lower part of the 

 opercular portion of the operculo-mandibular branch, to the sac- 

 cular dilatations numbered 2 and 3, and also to the mandibular 

 portion of the canal. 



IVie (glossopharyngeal Nerve. — I have been unable to trace any 

 portion of this nerve to the main canal. It seems, however, to 

 replace the anterior and dorsal branches of the vagi lateralis and 

 innervates the two sensory organs in the occipital commissure. 



The Vagus is very similar to that described in Esox, excepting 

 that there are no anterior branches given off from the vagi 

 lateralis. 



