Herrick, Werves of Siluvotd Fishes. 211 
lateralis accessorius. In one series in which this twig is larger 
than in others I traced it up to the skin of the dorsum in the 
fontanel between the two projections directed cephalad from the 
dorso-median part of the supra-occipital bone. STaNNus states 
(49, p. 85) that this nerve is absent in Silurus, but JuGeE finds 
it present in this species (’99, p. 106). 
3. Ramus laterahs vagi. 
The lateralis root of the vagus after separating from the 
caudal end of the tuberculum acusticum, runs back in the usual 
way dorsal and external to the VIII roots and the other mem- 
bers of the IX+X complex, emerging from the cranium by the 
vagus foramen. The twig, described above, which is detached 
to form the r. supra-temporalis IX apparently corresponds to a 
part of the r. supra-temporalis vagi of Menidia (viz. the twig 
for the organ in the squamosal bone); but seems not to be rep- 
resented in that nerve of Gadus, for in the latter case the supra- 
temporal ramus does not supply any organ in the squamosal 
‘bone. 
From the ganglion of the r. lateralis vagi are given off 
three small nerves. 
(1) The first joins the r. cutaneus dorsalis vagi (from 
which, however, it can be distinguished microscopically by the 
larger caliber of its fibers) and with that nerve curves up 
around the parotic process, at the caudo-lateral angle of which 
the two nerves separate. The coarser lateralis fibers all enter 
the supra-temporal bone and innervate the single organ of the 
main lateral line canal therein contained. 
(2) The second nerve passes directly outward to supply 
the fourth organ of the main lateral line, contained in the post- 
temporal bone. 
(3) The third nerve (Fig. 1, ad. ¢.) also runs dorsally 
around the parotic process and penetrates between the fibers of 
the dorsal musculature which arise from this portion of the 
cranium. Having reached the edge of the bone it divides, its 
branches being directed toward the mid-dorsal line, some caud-- 
ad, some cephalad of the point of division. This region is 
