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Show 132 ZOOLOGY OF TITE VOYAGE OF TilE BEAGLE. the adipose, or perhaps a trifle beyond it; two small spines. at its commencement; the first two soft rays simple, the others branched. Caudal forke~ for half Its length, the lobes equal; the whole fin contained about six and a half times in the entire length; the accessory rays very numerous, and partially fringing the upper and lower edges ~f the tail. Pectorals attached behind the gill-opening, rather below the middle, about two-thuds the leng.th ~f the head, of a somewhat triangular form, the rays gradually shortening from the first, whiCh IS the only one unbranched. Ventrals attached a very little in advance of the dorsal, rounded, or almost cut square at the ends, the rays being all nearly equal. They are scarcely sho~ter than the pcctor~ls: the space between their insertion and the commencement of the anal1s nearly double theu own length. There is no long scale or appendage of any kind in their axillre. CoLOUR.-" Dull leaden colour."-D.-In spirits it appears brown. The sides arc banded with some irregular transverse zebra-like marks, not noticed by Mr. Darwin, reaching from the back down two-thirds or three· fourths of the depth, some terminating sooner than others. All the fins brownish. Habitat, Falkland Islands. Mr. Darwin obtained three specimens of this remarkable fish all precisely similar, from a fresh-water lake in the Falkland Islands, in March. The lake was not far from the sea, and connected with it by a brook. He adds in his notes that the species is common there; that it is good eating, and grows to be about half as large again as the individuals procured. One of these specimens was dissected by Mr. Yarrell and myself, and presented the following internal characters, which are of importance to be noted. The coats of the stomach were thick and muscular; the resophageal portion with prominent longitudinal plicre. Its contents, so far as they could be ascertained, consisted of the remains of caddis-worms. The intestine was large, without any crecal appendages, but with one spiral convolution at the end of the first third of its length from the pyloric orifice : the entire length of the canal was four inches. The air-bladder was large, undivided, and of the same general form as in many of the Salrnonidce. There were two elongated flattened lobes of roe nearly ready for exclusion. The anal and sexual orifices were separated, but enclosed in a tubular sheath, common to both, directed backwards; the sheath itself lying in a groove in the abdomen, and five-eighths of an inch in length : the opening to the cavity of the abdomen and sexual organs was at the extreme end of this sheath, and partly closed by two lateral valves ; the opening to_the intestine, three-eighths of an inch short of the extremity. 2. APLOCHITON TJENIATUS. Jen. PLATE XXIV. FIG. 2. A· olivaceus, punctis fuscis minutissimis irroratus; lateribus vittd longit·udinali argente/ t : maxilla inferiore longiore. 3 FISH. 133 B. 3; D.I2; A. 2/13; C. 16, &c.; P. 18; V. 7. LoNG. unc. 3. lin. 10. FonM.-A much smaller species than the last, but the general form similar. Rather more elon .. gated, the depth being contained seven and a half times in the length. Head one-fifth of the length ~easured t~ the ba~e of the caudal fork. Snout a little longer, and more pointed. ~o~er JaW at all times a little the longest. Teeth similar, and similarly disposed. Nostrils Similar; ~u~ no pores on the crown, or only one on each side, and that not very distinct. All the fins similar. CoLoun.-N ot noticed in the recent state. In spirits it appears of a uniform greenish or olivaceous brown, the back and sides very minutely dotted with darker brown. There is a pale silver ban.d alo~g th~ middle of the side, not bounded, however, by any definable line, but shading off msens1bly mto the brown above and below. The irides are still bright, and appear to have been golden. Habitat, Goree Sound, Tierra del Fuego. T~ere are three specimens of this second species in the collection, all of the same Size, and not differing in any respect from each other, except that one of them ~~s thirteen rays in the dorsal fin, and fourteen soft rays in the anal. Mr. Darwm s notes state that they were taken at Goree Sound, Tierra del Fuego, in the mout~ of a fresh-water stream, where the water was quite fresh; and that when put mto salt water they immediately died. The silver band at once distinguishes this elegant species from the last, independently of its smaller size. The specimens appear full grown. There is the same peculiarity with respect to the anal and sexual orifices in this species, as in the one previously described. F Al\IIL y .-CLUPEID.lE. 1. CLUPEA FuEGENSIS. Jen. Mr. Darwin's collection contains a single individual of a species of Clupea from Tierra del Fuego so extremely similar to the young of the common Herring, that it might almost be mistaken for it. As it is small, and in not very good preservation, I shall merely point out some of its leading characters. Depth of the body the same as in a young IIerring of the same size. Belly carinated, but with the scrratures not more developed than in that species. Teeth the same, and very minute. The maxillary does not slope inwards quite so much at its upper extremity, before uniting with the intermaxillary; but the mouth and its several parts are in all other respects similar. The same may be said of the pieces of the opercle, excepting that there is a more sensible notch near the upper part of the posterior margin of the gill-flap, much as in the common Sprat. It |