124 



LO WER VET! TEBIIA TES. 



Gymnonoti, hut the hints furnished by the elongated body and increased number of 

 vertebroe, etc., may be iOusive." 



The Gyninoiioti are usually held to constitute a single family, Gymnotid.b, 

 although l)y Professor Gill the scaleless electric eel is made the type of a sejiarate 

 family, Eleetrophoridse. Professor Cope goes still farther, and, retaining the electric 

 eel alone in the order of Glanencheli, he refers the remaining species, constituting 

 the family of Sternopygidse, to the group of Plectospondyli (Eventogiiathi). Accord- 

 ins to him, the Electi'ophoridse are distinguished by the structure of the fins and the 



Fig. i2,~- ElectTophoriii electr'unis, electric eel. 



vudimental maxillary Iwnes from the Sternopygidie, with which they have been hitherto 

 associated. 



Of the two families, the Electrophoeid.e is supei-ficially characterized by the 

 absence of scales, and by the presence of an electric organ on each side of the l)ase 

 of the tail. Its single species, the famous electric eel {Electrophorus electricus), 

 inhabiting the rivers of Brazil, has excited much interest among anatomists. It 

 reaches a length of six feet, and is the most powerful of all the various electric fishes. 

 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, the other pair 

 along the anal fin. Each fasciculus is composed of fiat partitions, or septa, with 

 transverse divisions between them. The outer edges of the septa appear in nearly 

 parallel lines in the direction of the longitudinal axis of the body, and consist of thin 



