OCR Text |
Show FISII. 139 than to R!tombus, though possibly it may be found hereafter to serve as the type of a distinct subgenus in this family. The form of the dorsal fin, if correctly delineated, is remarkable. The size of the fish is not stated. RHOMBUS---? FonM.-Oval, approaching to rhomboidal. Breadth a little exceeding half the length. Eyes on the right side, near together, equally in advance, or the lower one perhaps rather more forward than the upper; between them a double osseous ridge. On the under side of the head, and nearly answering in pos1tion to the upper eye, is a deepish cavity, from whence proceeds a tentaculiform appendage four or five lines in length. Teeth very small, sharp, in scarcely more than two rows, and apparently confined to the under side. Lateral line sweeping over the pectoral. Dorsal commencing above the upper lip, and reaching nearly to the caudal, but leaving a minute space. Both sides of the body arc smooth, but the upper one appears to have lost its scales. Pectoral on the eye side about three-fourths the length of tho head. Length 5 inches. CoLOUR.-" Above pale purplish brown, with rounded darker markings."-D. Habitat, Bahia Blanca, Coast of Patagonia. AcHinus LINEATUS. D'Orbig. Achirus lineatus, D'Orb. Voy. dans L'Amer. Merid. At!. Ichth. Pl. 16. fig. 2. FonM.-Body oval, but with the dorsal and anal fins included, approaching orbicular; the greatest breadth rather more than half the length. Eyes on the right side, moderately near together, the upper one a very little in advance. Lmver jaw longest, projecting beyond the snout. Teeth forming a velutine band, very minute, and scarcely sensible except to the touch, confined to the side opposed to the eyes. Preopcrcle distinct from the operclc. A frw short thread-like cini on the under side of the head; two at the extremity of the snout being rather longer and more conspicuous than the others. Lateral line nearly straight throughout its course, somewhat higher at its commencement than afterwards, but taking no sweep. Both sides of the body rough, with ciliatcJ scales, but the upper one most so. The dorsal commences above the upper lip, and reaches, as also the anal, almost quite to the caudal: this last rounded. Pectorals entirely wanting. CoLoun.-Not noticed. Length 9 inches. Habitat, Rio Plata. This species was obtained by Mr. Darwin in the market at Buenos Ayres, where it is said to be eaten. It so exactly accords in form with the figure of the A. lineatus in D'Orbigny's Voyoge, that I have little hesitation in considering it the same, though, from the specimen being dried, there are no vestiges left of the transverse lines. Whether it be the A. lineatus of any other author I am uncer- |