536 'Journal of Comparative Neurology and Psychology. 



into two large branches. Of these the larger lateral one {op. (^)) 

 fuses with one {hue. (/)) of the two main divisions of the buccalis 

 VII. Sometimes the fusion occurs between the iwo undivided 

 trunks, but more often each divides into three or four branches 

 which then fuse in pairs or approximately so (fig. 25). The 

 resulting mixed nerves (r. nasalis externus of Wilder) supply the 

 neuromasts of the infraorbital series and the skin of th? side of 

 the snout. The other profundus branch {cp. (5)) comes into close 

 relation with the second division of the buccalis VII {hue. (2)), but 

 I can find little evidence of actual anastomosis. The combined 

 nerves (r. glandularis I of Wilder) supply the skin and the infra- 

 orbital series of neuromasts at the side and tip of the snout. 



KiNGSLEY refers to this union of branches of the ophthalmicus 

 profundus with the buccalis (maxillaris according to him) as a con- 

 dition reported only in Amphiuma. A casual examination of the 

 figures which Wilder gives of Cryptobranchus (Menopoma) and 

 of Siren will showthatsimilar (if not identical) anastomoses occur in 

 these forms. The prediction maybe safel}' made that careful study 

 of these forms will reveal the fact that as in Amphiuma it is a 

 union between lateral line (buccalis) and general cutaneous (oph- 

 thalmicus profundus) components. 



d. Trigeminal -fibers entering the dorsal VII. — -A third group 

 of fibers leaving the gasserian ganglion is made up of general 

 cutaneous fibers that at once associate themselves with rr. oph- 

 thalmicus superficialis VII and buccalis VII. Their subsequent 

 course will be considered in connection with the facial nerve. 



6. THE facial and AUDITORY NERVES. 



a. Roots of the facial and auditory nerves. — The fibers of this 

 complex arise by two groups of rootlets. The more dorsal group 

 comprises the lateral line fibers of the seventh nerve and is formed 

 by three rootlets. Of these the dorsal rootlet {Fllb (/)) enters 

 that portion of the medulla oblongata which in Necturus is desig- 

 nated by Kingsbury as the "dorsal island," a mass of alba occupy- 

 ing the extreme dorsal part of the medulla (figs. 7-10, //.) This 

 "dorsal island" suggests an homology to the lateral line lobe 

 (lobus Hneae lateralis) of cyclostomes, selachians and ganoids, 

 although Johnston (1906) asserts that the lateral line lobe and 

 the dorsal root of the "dorsal VII" are absent in aquatic amphi- 



