The Cranial Nerve Components of Petromyzon. 161 
ramus now being described is the ramus buccalis and the organs 
running forward from the cornea constitute the infraorbital row. 
At 324 a small ramus goes off laterally from the front end of 
the ganglion, is joined by fibers from the Gasserian ganglion, bends 
up and enters the profundus. This has been fully described above. 
It supplies the fibers tho the supra-orbital row of neuromasts. 
Returning now to the small ganglion beneath the auditory 
capsule, it is seen to extend a short distance caudal to the foramen 
by which its root comes down out of the capsule. From its eaudal 
end a single trunk arises which is composed in part of fibers coming 
out of the ganglion and in part of fibers coming down through the 
foramen and not connected with the cells of this ganglion. A definite 
bundle comes down along the caudal surface of the ganglion and 
trunk and it appears that much more than half of all the fibers 
making up this trunk come from the ganglion within the auditory 
capsule. The trunk is directed ventrally and a little caudally and 
immediately divides into two rami. The first is much the larger 
and ineludes all the fibers which pass through the ganglion together 
with a part of the definite bundle from the foramen; the second 
receives the remainder of the strand from the foramen. The first 
ramus, R. hyomandibularis, goes directly ventrad and laterad until 
it penetrates deep into the constrietor museles of the pharynx, then 
bends backward and outward until it reaches their outer surface 
again. While in the muscles it gives off two branches, the first of 
which is small and reaches the mucosa at the base of the first 
demibranch. The second, larger branch runs caudally imbedded in 
the muscles and divides into several branches which supply various 
bundles of muscle. 
As the trunk regains the outer surface of the pharyngeal muscles 
it ecurves again forward and runs downward and gains the outer 
surface of the branchial cartilage where it continues downward and 
forward beneath the lateral muscle. It divides into three branches 
which eontinue forward direetly beneath the dermis, subdivide and 
are lost in the plane of the eye (280). As the nerve decreases 
considerably in size before it divides into its terminal branches it 
is probable that it supplies general eutaneous fibers to the skin. It is 
impossible to trace the final branches because of their small size and 
the peeuliar charaeter of the fibrous tissue on the outer surface of 
the cartilage against which the nerves lie. This tissue takes the 
nigrosin stain and beyond a certain point of subdivision it is impossible 
