228 PISCES. 



ECHENEIS, Lin. 



This genus, as well as that of Pleuronectes, might forma particular family 

 in the order of the Malacopterygii Subrachiati. The fishes of which it con- 

 sists are remarkable for a flattened disk placed upon their head, composed 

 of a certain number of transverse, cartilaginous laminae, directed obliquely 

 backwards, dentated or spiny on their posterior edge, and movable, so that 

 by creating a vacuum between them, or by hooking onto various bodies by 

 means of the spines, they are enabled to attach themselves firmly thereto, 

 a circumstance which gave rise to the fabulous saying, that the Remora 

 possessed the power of suddenly stopping a vessel in the middle of its 

 swiftest course. 



The species are not numerous; the most common one that inhabits the 

 Mediterranean, Echen. remora, L. well known by the name of Rem&ra, is 

 the shortest, and has but eighteen lamina: in its disk. 



ORDER IV. 

 MALACOPTERYGII APODES. 



This order may be considered as forming but a single natural 

 family, that of the 



ANGUILLIFORMES, 



Fishes with an elongated form, a thick and soft skin which almost 

 renders its scales invisible, and but few bones. The great genus 



MUBJENA, Lin. 



Is recognized by the little opercula concentrically surrounded by the rays, 

 all of which are enveloped in the skin, which only opens at a considerable 

 distance back by a hole or species of tube, an arrangement which, by more 

 completely protecting the branchiae, allows these fishes to remain some 

 time out of water without perishing. Their body is long and slender; their 

 scales, as if encrusted in a fat and thick skin, are only distinctly visible after 

 desiccation; they have neither ventrals nor caeca. This genus has been 

 successively separated into five or six genera, which naturalists are com- 

 pelled to subdivide still more. 



ANGUILLA. 



Eels are distinguished by the two-fold character of pectoral fins and of 

 branchise opening under them on each side. 



