378 DEEP-SEA FISHES OF THE ATLANTIC BASIN. 



The gill-openings are rather wide, the branchiostegal membranes are largely developed, 

 with robust rays; the opercular bones are smooth and very thin; the branchial cavities 

 contain fonr complete arches. The specimens are so very fragile that I did not dare to puisne 

 my investigations further. 



The fins are those of an Anacanthine fish, but I could not see any transverse articula- 

 tions in the first ray of the first dorsal; they are not very distinct on the other median tins 

 except on the caudal, the only fin with slightly bifid rays; in the other fins the rays are 

 simple; at the. base of the long dorsal and anal fins the projecting heads of the interspinous 

 bones give rise to a serrated appearance. The first dorsal is small, but quite detached from 

 the second one in the two larger specimens; it rises just above the insertion of the pecto- 

 rals: its second ray is the longest and equals in height the commencement of the second 

 dorsal fin. This is greatly developed and maintains a nearly equal line throughout, but as 

 the body tapers toward the tail the fin increases in height in equal ratio. In size, shape, 

 ami development the anal is the exact counterpart of the second dorsal fin. The caudal 

 fin is quite distinct, its contour is lanceolate in the smaller specimen, nearly oval in the 

 older one, subtruncate with rounded edges in the oldest or biggest specimen. The pectorals 

 are distinctly lobate, which character is more marked in the smaller specimens; they are 

 of moderate size and broadly oval in contour. The ventrals certainly give the most striking 

 feature to this singular fish; they are inserted below and in front of the pectorals, at the 

 base, and on each side of the great abdominal cone. They are of great size, and the very 

 robust rays, ."i in number, are all elongated and considerably exceed the intervening mem- 

 brane, which only unites their basal portions; the internal and external rays are consider 

 ably less developed than the three median ones, the internal one is the shortest; both are 

 simple and without any trace of terminal dilatations. The three median rays all terminate 

 in a large beautiful lanceolate leaf like blade, through which, however, the ray continues 

 to the pointed extremity; they are all prolonged beyond the two first-mentioned rays, hut 

 the outer one is considerably shorter than the other Two; it is smooth and its terminal blade 

 is smaller. The third and fourth rays, counting from the outer one. are subequal, and bent 

 backwards extend very nearly to the root of the tail; at about the basal third of their 

 length they both present a singular angular dilatation, which looks like a thickened articula- 

 tion, but which is merely, so far as I can make out. a membranous dilatation. The great lan- 

 ceolate terminal blades are very large, being little less than one-fourth of the total length 

 of the ray which supports them; their edges are sinuous and they terminate in a fine point. 

 Judging from their length, strength, and development, these ventral paddles must be most 

 efficient for swimming; I know of no other fish possessing anything like them, and have, 

 therefore, thought proper to derive from so peculiar a character the generic name which I 

 have proposed for this singular fish. 



The next remarkable feature of my Eretmophorus is the huge abdominal cone, the base 

 of which occupies the entire, space between the insertions of the ventrals and that of the 

 anal fin. This cone appears to deyelop with age. and it is certainly larger and more prom- 

 inent in my oldest and biggest specimen, equaling in height that of the body just behind 

 the pectorals, where it is greatest. This abdominal cone is quite smooth; its skin, devoid 

 of scales, is silvery. 1 have not ventured to open it in any of the three specimens yet dis- 

 covered, for fear of damaging to a certainty these rare and very delicate creatures; but 

 the supposition that it contains most of the alimentary canal can not be far from the truth; 

 at its apex, which becomes cylindrical, is an aperture, evidently the vent, and behind this 

 a slender conical papilla on which 1 could not distinguish anything like an opening. 



The scales cover the whole body except the head and abdominal cone, which are, as I 

 have said before, naked. They are small, very adherent, cycloid, and marked with con- 

 centric lines. I have figured a few magnified (pi. xxxiv, tig. 1), to give an exact idea of 

 their characters; they are very similar to those of Hypsirhynchus hepatieus, Facciola. A 

 thin pellucid epidermal layer covers them. 



Only three specimens of Eretmophorus Kleinenbergi have, so far as I know, yet been cap- 

 tured and preserved; they were caught alive with a hand-net along with other pelagic an- 

 imals on the surface at the mouth of the harbor of Messina as the current was flowing in. 



