212 JOURNAL OF COMPARATIVE NEUROLOGY. 
very abundantly supplied with small pit organs, into some of 
which twigs from this nerve were traced. All of the other 
fibers of this nerve apparently have a similar distribution, save 
four branchlets, which enter each a single large pit organ. 
Three of these lie ina row running transversely to the body 
axis mesially of the post-temporal bone, and one near the mid- 
dorsal line farther caudad by about the thickness of one myo- 
tome, These apparently correspond to the dorsal pit line of 
Amia, Batrachus, Gadus, etc. 
The lateralis branch of the vagus runs back from its gang- 
lion quite deeply embedded in the dorsal musculature under 
the lateral line of the trunk. Behind the pectoral fin it sends 
a minute twig outward to supply a single large pit organ situ- 
ated just above the fourth pore of the lateral line canal of the 
trunk. At about the same position the lateral line nerve di- 
vides into ventral and dorsal branches, the latter being slightly 
larger. From the dorsal branch (Fig. 1, d. dat. X) two small 
twigs leave at once, whose ultimate distribution could not be 
accurately determined, probably for small pit organs farther 
dorsally. Then from the dorsal branch is given off the twig 
for the sixth canal organ, contained in the second drain-pipe 
bone, and immediately another dorsally directed twig for one 
of twolarge pit organs near the mid-dorsal line in the same 
transverse plane as the sixth pore of the trunk canal. The in- 
nervation of the other large pit organ just mentioned could not 
definitely determined, but is probably from a twig of the r. 
lateralis given off just caudad of the one for the sixth canal 
organ. 
Successive organs of the trunk canal are supplied by twigs 
from the dorsal lateral line nerve and other twigs are given off 
for small pit organs sparsely scattered over the body and for 
large pit organs in an irregular longitudinal row near the mid- 
dorsal line and at occasional intervals near the body canal, be- 
coming less frequent caudad. The nerve was followed and the 
skin examined microscopically as far back as the middle of the 
dorsal fin. None of the large pit organs were found save near 
the main canal or at various distances between it and the mid- 
