ELECTEIC EEL. 667 



Steknopygus. — Caudal fin none ; no trace of a dorsal fin. 

 Both jaws with small villiform teeth ; similar teeth on each side 

 of the palate. Body scaly. 



Four species, very common, and growing to a length of 

 30 inches. 



Carapus. — Caudal fin none ; no trace of a dorsal fin. A 

 series of conical teeth in each jaw. Anterior nostrils, wide in 

 the upper lip. Body scaly. 



One species (G. fasciatus) extremely common, and found 

 all over tropical America, east of the Andes, from 18 to 24 

 inches long. ^ 



Gymnotus. — Caudal and dorsal fins absent ; anal extending 

 to the end of the tail. Scales none. Teeth conical, in a single 

 series. Eyes exceedingly small. 



The " Electric Eel " is the most powerful of electric fishes, 

 growing to a length of six feet, and extremely abundant in 

 certain localities of Brazil and the G-uyanas. The electric 

 organ consists of two pairs of longitudinal bodies, situated 

 immediately below the skin, above the muscles ; one pair on 

 the back of the tail, and the other pair along the anal fin. 

 Each fasciculus is composed of flat partitions or septa, with 

 transverse divisions between them. The outer edge of the septa 

 appear in -nearly parallel lines in the direction of the longitu- 

 dinal axis of the body, and consist of thin membranes, which 

 are easily torn ; they serve the same purpose as the columns 

 in the analogous organ of the Torpedo, making the walls or 

 abutments for the perpendicular and transverse dissepiments, 

 which are exceedingly numerous, and so closely aggregated 

 as to seem almost in contact. The minute prismatic cells, 

 intercepted between these two sorts of plates, contain a 

 gelatinous matter; the septa are about one-thirtieth of an 

 inch from each other, and one inch in length contains a series 

 of 240 cells, giving an enormous surface to the electric organs. 

 The whole apparatus is supplied with more than 200 nerves. 



