692 ALLIS, [Vou. XII. 
distinct bundle lying on the ventral surface of the intracranial 
ganglion, near its anterior edge. Immediately beyond the 
vagus foramen, those fibres of the anterior root that have not 
entered into the first, or supratemporal branch of the vagus, 
turn directly outward and enter the first vagus ganglion, which 
is a well-rounded ganglion lying close to the side of the skull 
between the levatores arc. branch. int. posterior and anterior. 
From this first vagus ganglion (gv!) the truncus branchialis 
primus n. vagi arises, and close to it, from the posterior surface 
of the truncus at its base, two small, short nerves which run 
outward and backward to the inner surface of the levator arc. 
branch. int. post., which muscle they entirely or in large part 
supply. The truncus then runs outward and downward be- 
tween the two levatores arc. branch. int., and in all the speci- 
mens examined, excepting one, there separated into a ramus 
anterior and a ramus posterior. The former separates at once 
into two portions, the ramus pharyngeus n. vagi primi (fv"), and 
the ramus pretrematicus n. vagi primi (frzv"), the latter being 
the ramus branchialis posterior arcus primi of Stannius. The 
ramus pharyngeus turns forward, and then forward and inward, 
above the efferent artery of the second arch and between the 
levator arc. branch. int. ant. and the levator arc. branch. ext. 
primus, passes through the opening between the ligaments 
that connect the posterior edge of the first epibranchial with 
the anterior edge of the second infrapharyngobranchial, and, 
turning inward and forward between the first and second 
infrapharyngobranchials, is distributed to the tissues on the 
roof of the branchial cavity. 
The ramus pretrematicus (frv') runs at first forward, out- 
ward, and downward, and then separates into four branches, 
one of which turns inward and forward and joins the ramus 
pharyngeus, with which it passes through the opening between 
the articular and interarcual ligaments, connecting the first 
and second arches. The other three branches turn outward, 
downward, and backward, and lying close against the posterior 
surface of the levator arc. branch. ext. primus, reach the upper 
surface of the first arch beyond that muscle, and have the 
course and distribution already described. 

