EELS. 



89 



scarcely any have pelagic habits, but many enter or live in fresh 

 waters communicating with the sea. They are spread over all the 

 temperate and tropical seas. The genus of Herrings proper 

 [Clupea) includes more than sixty si)ecieSj of which several are 

 extremely common on our coasts, viz. the Herring (Clupea harengus) 

 of immense commercial value, the Sprat (C. sprattus), the Shad 

 (C.afosa and C.fintd), and the Pilchard or Sardine [C. pilchardus) . 

 The " Mossbanlier " (C menhaden) is common on the Atlantic 

 coasts of the United States. The economic value of this fish is 

 surpassed in America only by that of the Gadoids, and derived 

 chiefly from- its use as bait for other fisheSj and from the oil 

 extracted from it. Albula and iJfojos reach a size of three feet, but 

 are not esteemed as food. The largest species of the whole family 

 is the Tarpon [Megalops ihrissoides) [a specimen of which is 

 exhibited on the top of the case], from the Tropical Atlantic^ 

 exceeding a length of five feet, and excellent eating. 



The ChirocentridcB and Notopterida (Case 22 b) are small families, 

 inhabiting, the former the Indian Ocean, the latter fresh waters of 

 the East Indies and West Africa. 



The Gymnotidce (Case 22 a) are eel-like freshwater fishes from 

 Tropical America, of which the best known is the Electric Eel 

 [Gymnotus electricus, fig. 76) ; it is the most powerful of electric 



Tiff. 76. 



Electric Eel {Gymnotus electricus). 



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

 certain localities of Brazil and the Guianas. The electric organ 



