224 Journal of Comparative Neurology. 



nerve approaches the eye it gives off a general cutaneous twig 

 to the skin posteriorly of the eye, and a similar twig to the 

 under eyelid. Large fibers, also, are given off along the course 

 of the nerve to the post-orbital and infra-orbital sense organs. 



The exact position of the nerve relative to the eye varies, 

 apparently, according to age. In younger larvae it lies ventrally 

 of the extreme lateral border of the eyeball, while in older 

 specimens it approaches the mid-ventral region of the eye. 



At the transverse level of the eye the infra-orbital trunk 

 divides into the r. buccalis VII {p. VII.) and the r. maxillaris 

 V {mx. V.) (The term maxillaris is used with limitations dis- 

 cussed in Part Second.) The r. buccalis, continuing cephalad, 

 follows the outer and dorsal border of the maxillary and pre- 

 maxillary bones, ventrally of the external nares, to near the 

 middle line of the snout. Along the distal part of its course it 

 comes into close relation with twigs of the ophthalmicus pro- 

 fundus, but fuses with none of them. The terminal fibers of 

 this nerve have not all been traced to their termination, but 

 they have the appearance of lateralis fibers and there are lateral 

 line organs along the course of the nerve. Moreover, the re- 

 gion it traverses is liberally supplied with general cutaneous 

 fibers from the r. ophthalmicus profundus. Comparative evi- 

 dence, also, is in harmony with my conclusion that the r. buc- 

 calis is a purely lateral line nerve (v. Part II). 



The maxillaris V turns laterad from the point of division 

 of the infra-orbital nerve. Although it passes cephalad of the 

 transverse level of the eye, it extends at the same time into the 

 large ventrally projecting fold of the upper lip. The area it 

 innervates is postero-ventral of that innervated by the lateral 

 terminal branch of the ophthalmicus profundus V. 



It is possible that there are a few lateralis fibers carried out 

 a short distance in the r. maxillaris, but I can discover no con- 

 stant arrangement of this kind. 



^. — The Ramus Ophthalmicus Superficialis VIL 



The r. ophthalmicus superficialis VII arises from the gang, 

 lion of the anterior division of the lateralis VII root, dorsally of 



