70 EDWARD PHELPS AIXIS, JR. 



apparently considered to be the homologue of the similarly 

 named nerve of the Elasmobranchii. This latter nerve of the 

 Elasmobranchii was still called the ramus ophthabnicus profun- 

 dus trigemini, but there was a growing opinion that it belonged 

 to a cranial segment next anterior to that of the trigeminus. 



It was then still later found that communis fibers might also 

 form part of the ophthalmicus superficialis, and that, like the lat- 

 eralis fibers of that nerve, they issued from the medulla as an 

 apparent part of the root of the nervus facialis. Consistency 

 then evidently demanded that these communis fibers also be 

 included in the ophthabnicus superficialis facialis, but as that 

 term had come to mean a purely lateralis nerve, the communis 

 fibers were either still relegated to the ophthalmicus super- 

 ficialis trigemini or a new term, truncus supraorbitalis, was 

 given to the entire ophthalmic nerve, the term ophthalmicus 

 superficialis facialis still being employed to designate the later- 

 alis fibers only of the nerve. 



The ramus ophthalmicus superficialis of fishes thus came to be 

 considered to be a nerve formed by the secondary juxtaposition 

 of fibers derived from two adjacent segmental nerves, the gen- 

 eral cutaneous fibers of the nerve being derived from the nervus 

 trigeminus and the lateralis and coimnunis fibers from the ner- 

 vus facialis. This schema of the nerve still, however, left un- 

 accounted for those fibers that were known to be derived, in cer- 

 tain fishes, from the portio ophthalmici profundi, and although 

 this portio, as an independent nerve, had only been described 

 in a few fishes, there was no apparent reason for assmning that 

 it did not also exist in many, if not all, of those fishes in which 

 the profundus and trigeminus ganglia have completely fused with 

 each other. 



This confusion of terms and complication of conditions led 

 me, in my work on the mail-cheeked fishes (Allis, '09) to readopt 

 the tenn, ophthabnicus superficialis trigemini, first given to this 

 nerve, and to call its lateralis and communis fibers the lateralis 

 and communis trigemini. A name of some sort had to be given 

 to the nerve, and this one seemed to me to be the ''single name 

 already current" that Herrick ('09) has later suggested should be 



