MALACOFTERYGII APODES. 263 



Carapus, Cuv.(l) 



A compressed and scaly body; the tail much narrowed behind. 

 From the rivers of South America.(2) 



We might, perhaps, distinguish from the common species those 

 with an elongated snout only open at the end. (3) 



Sternarchus, Schn.(4) Apteronotus, Lacep. 



The anal terminated before it reaches the end of the tail, which is 

 furnished with a particular fin; a soft fleshy filament on the back, 

 lodged in a groove running to the end of the tail and retained there 

 by tendinous threads, which still allow it some degree of liberty, a 

 singular mode of organization, the use of which cannot be divin- 

 ed. (5) The head is oblique, compressed, naked, and the skin pre- 

 vents both the opercula and the rays from being seen externally; 

 rest of the body scaly; teeth small and crowded, and on the middle of 

 each jaw scarcely perceptible. The Sternarchi like the preceding 

 fishes inhabit the waters of South America.(6) 



Gymnarchus, Cuv. 



The body scaly and elongated, and the gills slightly open before the 

 pectorals as in Gymnotus; but a fin, with soft rays, occupies the 

 whole length of the back; and there is none behind the anus, nor un- 

 der the tail, which terminates in a point. The head is conical and 

 naked, the mouth small, and furnished with a single row of small 

 trenchant teeth. 



G. niloticus. The only species known; discovered in the Nile 

 by M. Riflfault. 



(1) Carapo, according to Marcgrave, the name of these fishes at Brazil. 



(2) Gymnotus macrourus, Bl., 157, 2; Carapo, Gm.; G. brachiurus, Bl., 157, 

 l;fasciatus, Gm.; G. albus, Seb., Ill, pi. 32, f. 3. 



(3) Gymnotus rostratus, Schn.,^1. 106. 



(4) Sternarchus, i. e. anus in the sternum. 



(5)1 rather think the separation is accidental, and that, in fact, it is one of the 

 muscles of the tail, which, as the skin is weak in this particular place, is easily de- 

 tached. 



(6) Gymnotus albifrons. Pall., Spic. Zool., VIII, pi. vi, f. 1; Lacep. II, vi, 

 146, 3. 



N.B. The Gymnotus acus, or fitrasfcr, belongs to the genus Ophidium, and the 

 Gymnotus notopterus. Pall, and Gm., Notoptere capirat, Lacep., to the Herrings. 



