No. 3.]| MUSCLES AND NERVES IN AMIA CALVA. 539 
branches arising from it are given, and there is accordingly no 
ramus ophthalmicus profundus in Trigla. That nerve, as a 
separate nerve, is also not described, so far as I can find, in 
any teleostean forms excepting Trichomycterus and Clarias, 
in which fishes it is described by Pollard (No. 97, pp. 392 and 
398). As Pollard describes no ramus ophthalmicus superficialis 
trigemini in any siluroid, it is exceedingly probable that the 
nerve described by him as a profundus is in reality the super- 
ficialis, its position in Trichomycterus being in that case most 
unusual. Pollard’s nomenclature or observation, in this instance 
as in some others, seems to vary somewhat from my own, 
and to lead him to somewhat different conclusions. In all 
siluroids, excepting the two above named, he says that “the 
ophthalmicus profundus may only be represented by some fibres 
running along with the ophthalmicus superficialis of the Facial”’ 
(No. 97, p. 398). By most other writers it is assumed that 
the ramus ophthalmicus profundus trigemini has fused com- 
pletely with the superficialis trigemini, which, so far as the 
course and position of the nerve are concerned, would amount 
to the same thing as the statement made by Pollard. Regard- 
ing such a fusion in individual cases and in general, several 
authors have expressed some doubt. To me it seems impos- 
sible. How a nerve that lies below the trochlearis and below 
the superior branch of the oculomotorius could fuse with a 
nerve lying above both those nerves without inclosing the 
two nerves in the single nerve so formed, it is difficult to 
imagine. It seems much more probable that the ophthalmicus 
profundus of elasmobranchs is entirely wanting in teleosts, and 
that the profundus elements in the latter are represented in the 
former by some branch or branches of the nervus profundus, 
its ganglion or its root, which lie above the two nerves con- 
cerned. Such a branch is found in Laemargus in the small 
branch which runs upward and forward above the rectus supe- 
rior (No. 26, p. 527). In teleosts and ganoids this small 
branch must undergo a special development as the rest of the 
nerve disappears, becoming the portio ophthalmici profundi, 
which may be found as a partly separate nerve, as in Amia, or 
as fibres completely fused with the ophthalmicus superficialis, as 
