NoRRlS, Nerves of Amphiuma. 539 



in Amblystoma" can be as truly applied to Amphiuma. The 

 smaller accessory general cutaneous and lateralis twigs given off 

 from the combined lateral line and gasserian ganglia in Rana seem 

 to represent possibly a ramus oticus. A determination of their 

 exact terminations would be necessary before coming to any con- 

 clusions in the matter. But it must be noticed that in both 

 Amphiuma and Amblystoma there occur some minute rudimen- 

 tary nerves givenoff from the gasserian ganglion. These possibly 

 correspond to the smaller accessory twigs in Rana. 



d. Ramus ophthalmicus superficialis VII and ramus oticus. — 

 The supra-orbital division of the "dorsal VII" forms a ventral 

 lateralis ramus and a dorsal portion consisting of both lateralis and 

 general cutaneous fibers. The ventral ramus is the r. opthal- 

 micus superficialis VII, that supplies all the neuromasts of 

 the supra-orbital series except some at the posterior end of 

 the series. Anteriorly in the nasal region it anastomoses with 

 the nasalis internus, as already noted. The dorsal portion of 

 the supra-orbital division, consisting of general cutaneous and 

 laterahs fibers, divides into a number of small branches supplying 

 the skin of the dorsal part of the head posterior to the eye, and 

 the neuromasts that form the posterior end of the supra-orbital 

 series and four or five neuromasts at the posterior dorsal end of the 

 infra-orbital series (fig. 24). In its distribution to neuromasts 

 this dorsal division seems to represent the ramus oticus of fishes. 

 In the latter it supplies the neuromasts of the posterior end of the 

 supra-orbital series and the first few neuromasts of the infra- 

 orbital series. In the r. oticus of fishes are found general cutaneous 

 fibers from the gasserian ganglion associated with the lateralis 

 fibers. In Amphiuma these general cutaneous fibers are dis- 

 tributed to a region which in some other Urodela, as Amblystoma, 

 is innervated by branches of the ophthalmicus profundus. In 

 some specimens of Amphiuma there occurs an anastomosis 

 between the maxillaris and this dorsal general cutaneous division 

 just before the latter breaks up into its smaller branches. We 

 have here the suggestion that these dorsal general cutaneous fibers 

 represent in part the posterior portion of the ophthalmicus super- 

 ficiahs trigemini. Both Wilder and Strong are of the opinion that 

 the ophthalmicus profundus in Amphibia "represents the united 

 ophthalmicus profundus and ophthalmicus superficialis trigemini" 

 of fishes. It is certainly true that the distribution of these dorsal 



