The natural history of fishes, amphibians, & reptiles, or monocardian animals . is the peculiarity observed by M. Geoffroy,that, independently of the ordinary branchiae, they have(an) apparatus ramified like trees, adhering to thesuperior branch of the third and fourth branchial arch,and which appear to be a sort of supernumerary gills:for the rest, their viscera resemble those of the otherSiluri. Their branchial membrane has from eight ornine to thirteen or fourteen rays : their pectoral spineis strong and dentated; but nothing of this is to befound in the dorsal and anal: their body is naked
The natural history of fishes, amphibians, & reptiles, or monocardian animals . is the peculiarity observed by M. Geoffroy,that, independently of the ordinary branchiae, they have(an) apparatus ramified like trees, adhering to thesuperior branch of the third and fourth branchial arch,and which appear to be a sort of supernumerary gills:for the rest, their viscera resemble those of the otherSiluri. Their branchial membrane has from eight ornine to thirteen or fourteen rays : their pectoral spineis strong and dentated; but nothing of this is to befound in the dorsal and anal: their body is naked andelongated, as are also the dorsal and anal fins; thereis no spine to the dorsal: the caudal is distinct. Thosewhich are known, have eight barbels : they come fromthe Nile, from Senegal, and from some rivers of , (forming the genus ?) Macropteromus Lac.(or ?) Clarias Gronov., have but a single dorsal, alto-gether radiated: others have a radiated and an adiposedorsal. The Heterobranchus 5-tentaculatus of Spix{fig, 9^.) appears to belong to a different division of. the family ; and the annexed cut will show it has amuch greater resemblance to the Sorubince than to theSilurince. In respect to the singular structure of the A A 4 360 CLASSIFICATION OF FISHES. ramified branchia, it is even a more extraordinary de-viation from the usual form than that of Syngnathus;so that, if the latter genus deserves to be placed as adistinct division of the osseous fishes, according toCuviers system, Heterobranchus should form a believe, however, that this variation in the bran-chia is not simply confined to one type only of theSiluridce, but to several; at least, the fishes that aresaid by Cuvier, Geoffroy, and Spix to possess theseramified branchia, are widely different in nearly allother parts of their structure. It is, in short, by thismeans, that nature indicates the analogy which theaberrant Siluridce, as a whole, bear to the amphibiansirens, which they represent; just in
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Keywords: ., bookcentury1800, booksubj, booksubjectfishes, booksubjectreptiles
