532 PA TEI ES Yo ba. @ hE 
as that given by Hasse (No. 52, p. 84, and No. 53, p. 296), 
based on the development and structure of the vertebral 
column, and by Maurer (No. 78, p. 476), based on the develop- 
ment of the muscle cells and muscle fibres. It differs from 
that recently given by Dollo (No. 23), in that he derives the 
Dipnoi and Amphibia directly from the “ Ganoides crosso- 
pterygiens,”’ instead of from some form intermediate between 
the teleostomes and elasmobranchs. 
7. Ramus Ophthalmicus Profundus Trigemini. 
The root of the ophthalmicus profundus in the adult Amia 
arises from the median or anterior side of the root of the tri- 
geminus, at a considerable distance from the base of that root, 
but still inside the cranial cavity (7f, Figs. 26 and 27, Pl. XXV, 
and Figs. 38 and 39, Pl. XXX). It pierces the lining mem- 
brane of the lateral chamber of the eye-muscle canal, and 
enters that chamber in front of the root of the trigeminus, but 
behind the trochlearis and oculomotorius. At the front end 
of the chamber, or in the passage leading from it into the 
orbit, it enters the profundus ganglion (g/) which lies near the 
upper end of the passage, internal to the pedicle of the ali- 
sphenoid, and external to the thin projecting plate of that bone 
to which the lining membrane of the eye-muscle canal and of 
the optic foramen is attached. The ganglion, in the adult, is 
somewhat arrowhead in shape, with the point of the arrow 
directed backward where the radix profundi joins it. It lies 
immediately below the trochlearis and above the oculomo- 
torius, but neither in the adult nor in larvae could any connec- 
tion with either of those nerves be found. In larvae the 
ganglion lies so close to the oculomotorius that it is difficult to 
determine whether there is or is not any connection between 
them. None could be established in any of my sections. 
From the upper, anterior corner of the ganglion the portio 
ophthalmici profundi of van Wijhe (fofp), which may be single 
or double, arises ; from the lower corner the radix longa (77) ; 
between these two, from the front edge of the ganglion, close 
to the base of the portio ophthalmici profundi two ciliary 
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