/^v 



THE LAMPREYS AND FISHES OF INDIANA. 



The word fish, as popularly employed, has a somewhat indefinite and 

 variable meaning. Not to mention its application to such creatures as 

 " shell-fish," the star-fish and the devil-fish, animals having only the re- 

 motest relationship to the pike or the bass of our streams, the word is 

 still made to include vertebrated animals very different from one an- 

 other. Nor are the zoologists wholly agreed as to what constitutes a fish. 

 Whether the lamprey eels and the sharks are or are not fishes is a matter of 

 dispute. According to the views of many recent writers, a lamprey eel, 

 a shark, and a catfish are as different from one another in their organiza- 

 tion as are a frog, a lizard and a bird. That is, each of the so called 

 fishes named above belongs to a distinct and different class of the verte- 

 brate sub-kingdom. The frog, the lizard, and the bird represent respect- 

 ively three other classes. Others would include among the true fishes the 

 sharks, but would exclude the lampreys. According to the views which 

 I adopt, the lancelets constitute a class, the lampreys another, the sharks 

 and the rays a third, while all other fish like animals compose a fourth 

 class, the true fishes 



Of these classes we have in Indiana representatives of two only, our 

 waters supporting neither lancelets nor any form of shark-like animals. 

 The classes represented are named and distinguished as follows: 



A. Body long and slender, eel-like ; skin smooth and slippery, wholly 

 devoid of scales; no paired fins; no lower jaw ; the mouth 

 placed in or near the center of a large, circular and sucker-like 

 disc ; no bony skeleton. Cydostomi, p. 148. 



AA. Body short or long ; usually, but not always, furnished with scales 

 or bony plates ; paired fins rarely entirely wanting ; lower jaw 

 always developed ; a bony skeleton always more or less devel- 

 oped, thus comprising a considerable number of membrane 

 bones. Pisces, p. 152. 



