206 JoURNAL OF COMPARATIVE NEUROLOGY. 
spinal nerve. Those which enter the brachial plexus no doubt 
distribute to the terminal buds found sparsely scattered over 
the pectoral fin and other cutaneous areas supplied by these 
nerves. The whole body surface as far back as the middle of 
the dorsal fin has been examined microscopically and is seen to 
be supplied with scattered terminal buds, which are unquestion- 
ably innervated by communis fibers from the r. lateralis acces- 
sorius either directly, in the case of the dorsal surface of the 
body, or by the communis branches from this nerve going out 
by way of the ventral rami of the spinal nerves. 
PoLLarD (’92, p. 530) says that in Clarias the r. lateralis 
accessorius ‘‘supplies the mucous canal at the base of the dorsal 
fin.”” Like several’ other recent writers, I am wholly at a loss 
to know to what he can refer. There is nothing like a canal 
in this position in Ameiurus and if such a canal occurs in any 
other siluroid it is most improbable that it should be innervated 
from this nerve. In the same paper POLLARD describes an anas- 
tomosis between the r. lateralis accessorius of Clarias, Callich- 
thys, Chaetostomus and Auchenapsis and the r. supratempor- 
alis vagi. This vagal branch cannot well be the vagal root of 
the r. lateralis accessorius, such as is found in Gadus and some 
other teleosts, for this root is of communis nature, while Pot- 
LARD’S account shows that his anastomosing nerve is really the 
r. supratemporalis vagi, i. e., a lateralis nerve, for it supplies 
the first canal organ of the main line caudad of the one sup- 
plied by the IX nerve. The vagal root of the r. lateralis acces- 
sorius is certainly quite lacking in Ameiurus. 
In the description of Silurus by JuGE (’g9) it is stated that 
the r. lateralis accessorius (nerve of WEBER) probably receives 
fibers from all of the sensory trigemino-facial roots. We have 
seen above that in Ameiurus this nerve is purely communis as 
in all other cases where its exact composition is known. JUGE 
worked only by gross methods and there can be but little doubt 
that a more exact analysis will show that in Silurus this nerve, 
or at least the portion which enters the trunk, is wholly com- 
posed of communis fibers. Of course this throws quite out of 
court the homology of the nerve of WEBER with dorsal rami of 
