188 General Notes. [February, 
has recently been described by Carriére for Cobitis, although he 
has not recognized its true character. The deep neuromasts 
found by the same author in Tinca are evidently somewhat simi- 
lar to those ot the catfish, and it is probable that connecting epi- 
thelial canals will yet be found. The only explanation of these 
canals which has so far occurred to me is, that they are the 
remains of a more complicated system of cutaneous canals simi- 
lar to those of the Selachii. 
In striking contrast to such deep neuromasts are those lodged 
on the projecting papilla of the blind fishes. Professor S. A. 
Forbes has described the distribution of these in his Chologaster 
papilliferus, a specimen of which he has kindly given me for exami- 
nation. I find that whereas the trunk in this species has only the 
free neuromasts, the head has neuromastic canals arranged in the 
ordinary way, and corresponding roughly in their course to the 
chief tracts of the projecting papilla. A singular circumstance 
is, that they have only four openings on each side, one posterior 
above the gill-aperture and three anterior on the snout, the pores 
of the mandibular, infraorbital and supraorbital canals respect- 
ively. 
I take the opportunity of mentioning here that the absence of 
pigment in the pigmentary epithelium of the retina of this species 
as very significant. 
2. On the fate of the spiracular cleft in Amia and Lepidosteus.— 
It is generally supposed that the spiracles of the sturgeon are 
unrepresented in Amia and Lepidosteus, but a minute slit may 
be seen in both genera on either side of the roof of the mouth, 
immediately in front of the dorsal ends of the first branchial 
arches, leading into diverticula of the mouth-cavity—the rudi- 
mentary spiracles. If a bristle be pushed into one of these slits, 
it will be found to pass through a canal in the primordial cranium ~ 
_immediately*abeve the anterior end of the hyomandibular articu- 
ation, and to be only prevented from emerging on the roof of the 
‘skull by the squamosal bone. Sagemehl has seen the canal in 
mia without attributing to it any morphological significance. 
In series of sections through young specimens of both genera, I 
find a free neuromast projecting from the epithelium of the ante- 
rior wall of the distal part of the cleft, supplied by a distinct 
_™ division of that dorsal branch of the ¢rigemunus (the ramus oticus 
= of Van Wijhe), which is distributed to the neuromastic canal in 
the squamosal bone. I conclude that the distal part of the cleft 
is epiblastic in origin, although Balfour believed (as far as Lepi- 
dosteus is concerned) that it never acquires an opening to the 
exterior. Ina recess of the anterior wall of the spiracle in Amia 
is situated a pseudobranchia. This has recently been styled an 
“opercular pseudobranchia,” in accordance with Gegenbaur’s 
= views as to the homology of the pseudobranchia of the Teleosts, 
_ but the discovery of its relations to the spiracular cleft demon- 
