684 ALLIS. [Vor. XII. 
As the root of the glossopharyngeus issues from under the 
root of the n. lineae lateralis vagi it receives, from that root, 
the root of the so-called dorsal branch of the glossopharyn- 
geus. This latter root runs outward with the main root of 
the nerve, lying immediately behind that root, closely applied 
to it, and in the adult issues with it, through the same fora- 
men, and enters the same ganglion. As the two roots pass 
outward between the two terminal branches of the ramus pos- 
terior acustici, there is an apparent interchange of fibres, the 
nature of which could not be satisfactorily determined. The 
nerve in Amia thus seems to differ in this respect, though not 
in position, from the nerve in Protopterus (No. 89, p. 316). 
In larvae, as already stated, the dorsal root usually issues 
from the cranium by a distinct and separate foramen lying 
immediately behind the foramen of the main root, and forms a 
ganglion separate and distinct from the ganglion of that root. 
From this ganglion arises the ramus dorsalis of the nervus, 
which runs upward, backward, and outward along the outer 
surface of the intercalar, internal to the levator arc. branch. 
int. ant. Immediately below the surface of origin of that 
muscle, it pierces the intercalar and then the chondrocranium 
by a special foramen, and issues on the upper surface of the 
cranium on the bottom of the temporal groove. There it 
separates into two portions, one of which turns outward, 
enters the squamosal, and supplies organ 17 infraorbital of the 
lateral sensory canals. The other portion turns medianward, 
runs external to and superficial to, or through, the communica- 
ting branches from the trigeminus to the vagus, superficial to 
the anterior extension of the trunk muscles that fills the tem- 
poral groove, and supplies the middle dorsal head line of pit- 
organs (No. 3, p. 516). In Laemargus (No. 31) this dorsal 
branch of the glossopharyngeus leaves the main root of the 
nervus proximal to the ganglion of that root, and contains no 
ganglion cells. It is accompanied by or contains fibres that 
are distributed to fibrous tissues. 
The main ganglion (gg/) of the glossopharyngeus, in the 
adult, is a somewhat elongated structure, lying close against 
the outer surface of the skull, and extending downward and 

