222 



FISHES 



of the greatly elongated and enlarged pectoral fins (Fig. 

 158). By means of vigorous, quick strokes of the tail and 

 enlarged tail fin, the fish is able to jump from the water 

 into the air. Then the large pectoral fins are spread and 

 the fish floats on the air somewhat as a man borne by a 

 parachute. It is asserted that some of the larger species 



Fig. 158. — Flying fish. 



actually vibrate the pectoral fins, thus producing a real 

 flight capable of prolonged duration. 



The bony fishes, for the most part, have large, conspicuous 

 eyes, without eyelids, but covered \\ith a thin, transparent 

 skm. There are some, however, that live in the caves and 

 underground streams of Illinois, Indiana, Kentuck}^, 

 Tennessee, and Alabama, that have rudimentary eyes, — 

 so rudimentary that in two or three species, at least, they 

 are wholly valueless as organs of vision. The bodies of 

 these fishes arc colorless and translucent. One species 

 Uves in the Mammoth Cave of Kentuck}'. 



The eels are bony fi.'ihes with long, cylindrical bodies 

 beai'ing small inconspicuous scales. The common eel 

 (Fig. 159) is found on Ixitli coasts (if the .\lhuitic and in 

 the rivers, lakes, and streams of the eastern I iiitcd States, 



