690 ALLIS. [Vot. XII. 
and, lying lateral to, and superficial to, the trunk muscles, and 
internal to the median process or leg of the suprascapular, 
which in embryos is simply a ligament, reach the under surface 
of the extrascapular near its lateral edge. Here the branch of 
the nervus lineae lateralis separates into two portions, one of 
which goes to supply organs No. 18, infraorbital in the extra- 
scapular, and No. 19, infraorbital in the suprascapular, and the 
other to the organs of the supratemporal cross-commissure and 
those of the posterior dorsal pit line (No. 3, p. 517). 
After giving off its first branch the nervus lineae lateralis 
leaves the vagus, runs backward, outward, and slightly downward, 
internal to the levatores arc. branch., between them and the 
trunk muscles, and then slightly upward, internal to the gian- 
dular formation which I have already described as probably 
being the thyroid gland. At the front edge of the supracla- 
vicular the nerve turns downward and backward, then, beyond 
that bone, directly backward, and, lying slightly imbedded in 
the fissure between the dorsal and ventral portions of the 
trunk muscles, continues its slightly undulating course toward 
the tail. Its branches are distributed to organs 20 and 21, in- 
fraorbital, in the supraclavicular, and to the organs of the lateral 
line and the body pit lines, as already described in my earlier 
memoir (No. 3, p. 518). 
The first branch of the vagus, the one arising from the root 
of the nerve, gives off a small intracranial branch, and then, 
after reaching the outer surface of the head with the first 
branch of the nervus lineae lateralis, separates into two main 
portions. One of these portions turns forward along the lateral 
edge of the anterior extension of the trunk muscles and runs 
directly into and anastomoses completely with one of the 
branches of the first pair of dorsal branches of the ophthalmicus 
trigemini, as already described in describing that nerve. This 
branch of the vagus seems to be the nerve described by Pinkus, 
in Protopterus, as a communicating branch from the lateralis 
facialis to the lateralis vagi. Like the nerve in Protopterus, it 
comes into intimate relations with a branch of the lateral, or 
so-called dorsal, branch of the glossopharyngeus, as already 
stated. From it branches are sent medianward and laterally to 

