FISH. 149 
Form.—Body thickish, the greatest depth and thickness nearly equal, the former about one-twenty- 
fifth of the whole length. From the head to the vent heptangular ; tail quadrangular: all the 
angles sharp and distinctly marked. The middle lateral ridges in the heptangular portion pass 
downwards at their extremities to terminate at the vent. Sixteen transverse plates before the 
dorsal: only fifty-two in the whole length. Head short, about one-eleventh of the entire 
length, not more compressed than the body. Crown not much elevated, but with distinct 
occipital and nuchal ridges. Orbits rising in ridges above the eyes, the interocular space being 
hollowed out: also a ridge commencing between the eyes, and passing forwards along the base 
of the snout, but not reaching to its extremity. Snout itself very short, its length only one- 
third the entire length of the head, narrower than the head vertically, nearly cylindrical, the 
tip slightly recurved. A few very short minute filamentous threads scattered about the head, 
more particularly one over each eye. 
Dorsal placed much as in the last species, and terminating a little before the middle; the 
rays delicate and not easily counted, about twenty. Vent beneath the commencement of the 
dorsal. No anal distinguishable even under a lens. Pectorals very small. Caudal moderately 
distinct. 
Cotour.—Grey: a spot on the gill-cover, and the belly, dusky. The carine which form the edges 
of the under surface of the body are darker still, and shew a fine dark line on each side 
extending to the caudal. 
Habitat, Bahia Blanca, Northern Patagonia. 
Apparently another new species of this genus, taken by Mr. Darwin at 
Bahia, and, like the last, well-marked ; especially by the short filaments above 
the eyes, which I am not aware occur in any other known species. 
