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Show 280 PISCES. found to exceed twelve and fifteen feet in length, and to weigh more than twelve hundred pounds. One specimen was cap. tured whose weight amounted to near three thousand pounds. The flesh is not much esteemed, and is sometimes unwholesome but the finest isinglass is made from its natatory bladder. r: is also found in the Po. North Arnerica has several species of this genus which are peculiar to it. ( 1) PoLYODON, Lac.-SPATULARIA, Sh. These fishes are recognized at once by the enormous prolongation of their snout, to which its broad borders give the figure of a leaf. Their general form and the position of their fins, remind the ob· server of a Sturgeon, but their gills are still more open, and the operculum is prolonged into a membranous point which extends to near the middle of the body. The mouth is well cleft and furnished with numerous small teeth. Theif upper jaw is formed by the union of the palatines with the maxillaries, aud the pedicle has two arti· culations. The spine of the back is furnished with a cord like that of the lamprey; and the spiral valve, common to almost all the Chon· dropterygii, is found in the intestine, but the pancreas begins to be divided into cceca-they have a natatory bladder. But a single species is known, the Polyodon feuille, Lacep., I, xii, 3; Squatus spatula, Manduit, Journ. de Phys. 1774, pl. I I. From the Mississippi. CHIMJERA, L~n.(2) The Chimcerce are closely allied to the Sharks in their general form and in the position of their fins, but all their branchice open exter· nally by a single apparent hole on each side, although if we penetrate more deeply, we find that they are attached by a large part of their edges, and that in fact there are five particular holes terminating in the bottom of the common aperture. A vestige of an operculum, however, is concealed under the skin. The jaws are still more re· duced than in the Shark, for the palatine and tympanic bones are {1) .!l.cip. oxyrhynchus, Lesueur, Amer. Phi.los. Trans. new series, vol. I, P· 394;-.!l.cip. brevirostris, Id. lb. 390; .!l.c. rubicundus, Id. lb. 388, and pl. xii, which appears to bear a close resemblance to the Sterlet;-.!l.c. maculosus, Id. lb., 392, approaches the Common Sturgeon. (2) This name was given to them on account of their fantastic figure, which, when they are carelessly dried, as was the case with the specimens fidt repre· sented by Clusiu8, .!J.ldrovandus, &c., appears monstl•ous. CllONDROPTEH.YGU BRANCIIIIS LIBERIS. 281 also mere vestiges suspended to the sides of the snout, and the vomer is the only representative of the upper jaw. Hard and indivisible plates supply the place of teeth, four on the upper jaw and two on the lower. The snout, supported like that of a Shark, projects forwards and is pierced with pores arranged in tolerably regular lines; the first dorsal, armed with a strong spine, is placed over the pectorals; the males are recognized, as among the Squali, by bony appendages of the ventrals, which are divided, however, into three branches, and they have besides, two spinous lamince situated before the base of these same ventrals; a fleshy appendage between the eyes is tet•minated by a group of small spines. The intestine of the Chimrerce is short and straight, it is furnished, however, with the spiral valve, as in the Shark. They produce very large coriaceous eggs with flattened and hairy borders. In the CHIMJERA, Cuv. Or true Chimcera, the snout is simply conical; the second dorsal commences immediately behind the first and extends to the tip of the tail, which is drawn out in a long filament, and is furnished beneath with another fin similar to the caudal of a Shark. But one species is known. C. monstrosa, L.; Bl., 124, and Lacep., I, xix, 1, the female; vulg., King of the Herrings; the Chat of the Mediterranean. (The Arctic Chimcera.) Two or three feet long, of a silvery colour, and spotted with brown. Ft·om the Northern and Eut·opean seas. In the CALLORHYNcHus, Gronov. The snout is terminated by a fleshy appendage resembling a hoe as to form. The second dorsal commences over the ventrals and terminates opposite the beginning of the fin attached to the under part of the tail. But one specied is known, Cltim. callorhynch., L.; Lacep. I, xii, a female. (The Antarctic 'Chimcera.) From the South Seas. VoL. II.-2 L \ |