FISH. 165 
STEGASTES IMBRICATUS. p. 63. 
I am informed by Mr. Lowe, of Madeira, that this is the same as the Glyphi- 
sodon luridus of Cuvier and Valenciennes.* Their description is so short, that I 
failed to recognize it; and I was induced to consider it as a new genus from the 
circumstance of its possessing vomerine teeth. Whether these teeth exist in any 
other species, or have only been presumed absent in all, because not found in 
some, I am not aware. But here again we see how little such a character is to be 
depended upon. 
Famity.—BLENNID/. 
Mr. Darwin’s collection contains two new forms from South America, closely 
allied to each other, yet forming distinct genera, and which will not enter into 
any of those described by authors. At first it was conceived that they were 
Malacopterygian fishes, more especially from their having all the rays in the 
dorsal and anal fins articulated ; and to belong to the Apodal division of that 
group, from their being supposed to be without ventrals ; but, on a closer inspec- 
tion, the ventrals, which are very small, were found to have been overlooked, and 
it was evident altogether that the true place of these fishes in the system was 
amongst the Blennide. The mention of this circumstance will explain why 
they were omitted to be noticed in their proper place. 
These two genera, so far as can be judged from the situations in which Mr. 
Darwin obtained them, have the same habits as the Blennies, lurking under stones 
and weeds ; and I propose to give them respectively the names of I/wocetes and 
Phucocetes. 
Genus.—ILUOCCETES.* Jen. 
Corpus elongatum, antice subcylindricum, postice compressum, ensiforme, leve, nudum, 
alepidotum. Rostrum breve, obtusum, rotundatum, ultra maxillam inferiorem pro- 
ductum. Dentes acutt, subconici, in utrdque maxilla uniseriati: supra canint duo 
fortes, curvati, antici, et pre serie exstantes: in vomere dentes pauct acult aggre- 
gati; in utroque palatino uniseriati. Lingua levis. Oculi grandes, prominult. 
Apertura branchialis mediocriter fissa, membrana quinque-radiatd. Mazille, os 
suborbitale, et preoperculum, tubiporis cutaneis brevibus ad margines fimbriate. 
Pinne ventrales jugulares, minute, gracillissime, triradiate. Pinne dorsalis et 
analis prelong@, caudali coalescentes, radiis omnibus articulatis. 
If I am right in placing this new genus amongst the Blennide, it will evidently 
take its place next to Zoarces, to which it is more nearly allied than to any other 
* Hist. des Poiss. tom. 5. p. 356, + Ab avs limus, et xorrn cubile. 
