Herrick, LVerves of Silurotd Fishes. 229 
though the terminal pore of the infra-orbital canal lies only 1 
mm. from the second supra-orbital pore. 
Ameturus catus, L. This is the channel cat of the Potomac, 
or white cat fish, and I am indebted for a fine specimen 32 cm. 
long, from Beecher Point, Fla., to the U. S. Fish Commission. 
The lateral line canal is conspicuously present the whole length 
of the body to the base of the tail fin. The canals of the head 
were not fully dissected out; but the surface indications, so far 
as observed, are similar to those of A. nebulosus of the same 
size. The temporal region was, however, carefully dissected 
and the conditions here found to be identical with those of the 
large specimen of A. nebulosus last referred to. The opercular 
canal joins the main canal through two similar tubular bones 
and the course of the main canal through the squamosal, extra- 
scapular and post-temporal is likewise the same. 
Leptops olvaris, Rar. (Pilodictis olivaris, JoRDAN and 
GILBERT). Ina small specimen of the mud cat fish 17 cm. 
long I find the lateral line canal of the body complete from the 
head to the tail. It is a very minute canal embedded in the 
dermis. No small accessory ossicles behind the post-temporal 
were observed. The main canal of the head passes through 
the post-temporal bone, then after a short course in which it is 
not enclosed by the bone it enters the squamosal. Within the 
squamosal the main canal is joined by the opercular canal. The 
latter passes downward and forward for a short distance in the 
squamosal bone, then over the most caudal edge of the hyo- 
mandibular bone, just cephalad of opercular bone, to enter the 
- dorsal edge of the preoperculum. The extent of the canal 
dorsally of the preoperculum is somewhat longer than that 
within the preoperculum and this portion is enclosed by several 
very delicate supra-opercular ossicles which may be either in- 
complete rings or tubular bones entirely enclosing the canal. 
The first is a long bone of the latter type and quite free from 
other bones except at its ends. Then follow one or two ossicles 
which are partially or wholly incomplete externally, while the 
last one wholly encloses the canal. All of these except the 
first are firmly co-ossified to the hyomandibular bone and 
