242 
THE TANGANYIKA TROBLEM 
intestinal and visceral nerve cords, and to the right pallial 
nerve, Fig. 23. From the right pleural ganglion a nerve 
passes out to the mantle, and a branch from this anas- 
tomoses with a branch on the pallial nerve just described. 
In like manner, on the left, the pleural ganglion gives birth 
to a nerve on that side, Fig. 23, which passes out and 
probably anastomoses with a twig given off from the 
supra-intestinal ganglion, but I was not able to trace this 
nerve throughout its entire course. 
Unlike the sub-intestinal ganglion, the supra-intestinal 
Fig. 24 . — Bythoceras minor shell front and back. The right-hand figure 
showing the characters of the operculum. 
is carried on a very long supra-intestinal connective, Fig. 
23, exactly as it is in Cerithium or Aporrhais. Viewed 
from the side, the cerebro-pedal and pleuro-pedal con- 
nectives are seen to be of considerable length, rather 
longer than the same structures in Voluta, but not so long 
as those in Nassopsis or in Strombus. The pedal ganglion 
has the bulbous form encountered in the true Cerithiidae, 
and in like manner there pass from the lower extremity 
of each pedal ganglion two predominent foot nerves. 
