53^ 'Journal of Comparative Neurology and Psychology. 



and the other to the mesal surface of the lateralis trunk. As the 

 combined nerves pass anteriorly the general cutaneous components 

 shift their positions, the median one becoming dorsal and the 

 ventral one shifting to a lateral position. The main combined 

 trunk soon divides into a dorsal and a ventral division, each con- 

 sisting of lateralis and general cutaneous fibers. Each division 

 then divides into two rami. 



c. Ramus huccalis VII, and ramus jnaxillaris V . — The ventral, 

 or infra-orbital division, forms a ventrally situated ramus consisting 

 solely of laterahs fibers, the buccalis VII, and a more dorsal one 

 of general cutaneous fibers with a few lateralis fibers, the maxillaris 

 V. The few lateral line fibers mixed with the maxillaris are soon 

 given off to certain neuromasts of the infra-orbital series posterior 

 to the eye. The r. buccalis innervates the neuromasts of the 

 infra-orbital series anterior to the eye. Its two main divisions 

 that anastomose with the r. ophthalmicus profundus V have been 

 described. The maxillaris of Amphiuma seems to be distributed 

 chiefly to the skin of the side of the head posterior and a little 

 anterior to the eye, but it does not run as far anteriorly as in most 

 Urodela that have been figured, in the more anterior parts of the 

 head being replaced by branches of the opththalmicus profundus. 



The term, ramus maxillaris V, is here used with the limitations 

 that CoGHiLL gave it. Strong (1895) called attention to the strik- 

 ing parallelism between trigeminal and lateral line branches in 

 the tadpole of the frog. This is especially noticeable between 

 certain so-called accessory lateral line branches of the ophthal- 

 micus superficialis and the buccalis and so-called accessory trigem- 

 inal twigs. Of these the most striking is the close relationship 

 between the buccalis and the larger of the accessory trigeminal 

 branches. Coghill's contention that the so-called maxillaris in 

 Urodela is the homologue of this larger accessory trigeminal twig 

 of the tadpole seems to me valid. The distribution of the maxil- 

 laris in Amphiuma agrees very closely with the distribution of this 

 accessory tw^ig in the tadpole. The intimate union of maxillaris 

 and buccalis in Amphiuma suggests the parallelism in the tadpole 

 between the buccalis and the accessory trigeminal branch. The 

 distribution of the terminal branches of the ophthalmicus pro- 

 fundus V, palatinus VII and maxillaris V in Amphiuma agrees 

 almost to details with that in Amblystoma. Coghill's conclu- 

 sions that "there is no distinct maxillaris branch of the trigeminus 



