OCR Text |
Show 268 PISCES. appendages that decorate various parts of its body, presents a most singular appearance: it is the Syngnathus foliatus, Shaw, Gen. Zool., V, ii, pl. 180; Lacep., Ann. du Mus. IV, pl. 58, f. 3. The SoLENOSTOMus,( 1) Seb. and Lacep. Differs from Syngnathus in being furnished with very large ven· trals behind the pectorals, united with each other and with the trunk, that form a kind of apron, which, like the pouch of the Syngnathi, serves to retain the ova. There is a dorsal with few, but elevated rays near the nape; another ve1·y small one on the origin of the tail, and a large pointed caudal; otherwise very similar to Hippocampus. But a single species, the Fistularia paradoxa, Pall., Spic., VIII, iv, 6, is known; it inhabits the Indian Ocean. PEGAsus, Lin. A salient snout, formed as in the preceding divisions, but the mouth, instead of being at its extremity, is under its base; it reminds us, by its protractility, of that of a Sturgeon, but is composed of the same bones as in ordinary fishes. The body is mailed like that of a Hip· pocampus and Solenostomus, but the trunk is broad and depressed, the branchial apertures are on the side, and there are two distinct ventrals behind the pectorals, which are frequently large, whence the name of the genus. The dorsal and anal are opposite to each other. The intestine being lodged in a cavity wider and shorter than that of the Syngnathi, has two or three flexures. Some species are found in the Indian Ocean. (2) ORDER VI. PLECTOG N A THI. We have now passed from the preceding five orders of bony or fibrous fishes, with free and complete jaws, to the sixth, ( 1) Solenostomus, mouth like a tube, from trCoJ>..nv, tube, and ~op.r~., mouth. (2) PegaJus draco, L., Bl., 209;-PegaJ. rwtans, Bl., 121;-Peg. volans, L.;P. laternarius, Cuv., whose snout is furnished with six longitudinal rows of den· tat ions. PLECTOGN AT HI. 269 which may be approximated to the Chondropterygii, with which it is allied by the imperfection of the jaws, and the tardy induration of the skeleton ; this skeleton, however, is fibrous, and its whole structure is that of ordinary fishes. The most distinguishing character of the order consists in the maxillary bone being soldered to the side of the intermaxillary, which alone constitutes the jaw, and in the mode in which the palatine arch is connected with the cranium, which, being by a suture, consequently renders it immovable. Besides this, the opercula and rays are concealed under a thick skin, through which only a small branchial fissure is visible. ( 1 ) Of ribs, nothing is to be found but very small vestiges. There are no true ventrals. The intestinal canal is ample, but without creca,(2) and in almost every instance there is a large nata tory bladder. This order comprises two very natural families, characterized by their mode of dentition. FAMILY I. GYMNODONTES. The Gymnodontes have jaws, which, instead of teeth, are furnished with an ivory substance, internally divided into laminre, whose ensemble resembles the beak of a Parrot, and which in fact consists of true teeth united, that succeed .each other as fast as they are destroyed by trituration.(3) The opercula arc small, and there are five rays on each side, all of which are but imperfectly seen. They live on Crustacea and fucus, their flesh is mucous, and that of several species is considered poisonous, at least in certain seasons. (1) This peculiar arrangement, indications of which are visible in the Chiro· nectes, has led several naturalists to believe that both opercula and rays are wanting in the Plectognathi; it is a mistake, however, for thev are provided with them like other fishes. · (2) Dloch erroneously attributes creca to genus Dodon. (3) See my Le9ons d' A nat. Comp. vol. Ill, p. 125. \ |