124 



LOWER VERTEBRATES. 



Gymnonoti, but the Lints furnished by the elongated body and increased number of 

 vertebrae, etc., may be illusive." 



The Gymnonoti are usually held to constitute a single family, Gtmnotidje, 

 although by Professor Gill the scaleless electric eel is made the type of a separate 

 family, Electrophoridse. 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 (Eventognathi). Accord- 

 ing to him, the Electrophoridse are distinguished by the structure of the fins and the 



Fig, 82. -.- Electrophorus electricusy electric eel. 



rudimental maxillary bones from the Sternopygidae, with which they have been hitherto 

 associated. 



Of the two families, the ELECTEOPHORiDiB is superficially characterized by the 

 absence of scales, and by the presence of an electric organ on each side of the base 

 of the tail. Its single species, the famous electric eel {JElectro2}horus 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 electiic 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 flat 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 



