Herrick, Nerves of Siluroid Fishes. 181 
tico-lateralis systems respectively. Those of the former system, 
the terminal buds, are, so far as I have observed, all alike and 
similar also to the taste buds of the buccal mocosa save that 
they are somewhat larger and their nerve fibers are more heavily 
medullated. The acustico-lateralis system includes the organs 
of the internal ear (not considered in the present contribution), 
the organs of the lateral line canals and the pit organs, of which 
in Ameiurus there are two types; viz large pit organs and small 
pit organs. The large organs evidently correspond to those so 
often described in the literature under the name pit organs, as 
in Amia, Gadus, Menidia and many other teleostean fishes. 
They are not numerous, probably less than fifty on each side of 
the body in the specimens of Ameiurus melas which I have 
studied, while the small pit organs are very abundant indeed. 
The organs of the acustico-lateralis system are collectively termed 
neuromasts and their structure is considered more in detail in 
Part II. 
Part I. THE Craniat NERVEs. 
I. THE TRIGEMINO-FACIAL COMPLEX, 
It has long been recognized that the trigemino-facial com- 
plex of siluroids is much more intricate than that of most other 
teleostean fishes. STANNIUS mentions as an additional difficulty 
in Silurus a peculiarity which has embarrassed our work on 
Ameiurus also; viz., the fact that the fiber characters of the 
different components are much less marked than in most other 
fishes. Nevertheless Srannius was able to give (’49, p. 25) a 
very exact description of the central connections of the V + VII 
roots of Silurus. 
Of the two fish types whose components I have previously 
studied in detail, Menidia exhibits the trigemino-facial roots and 
their ganglia in an almost digrammatic simplicity which we may 
well regard as primitive, while Gadus presents the same com- 
ponents arranged according to the same general scheme, but 
crowded closer together so that the relations, though discernable 
with precision, are much more difficult to make out. This 
process has been carried still farther in Ameiurus and all of the 
