DISTRIBUTION OF SPECIE?,. 



87 



Table sJioicing the Distribution of the Sixties in tlie Different, River-Basins Continued. 



From the above table, it will be seen that the Dumber of species 

 inhabiting any one river-basin rapidly increases as we leave the 

 Atlantic streams for those of the Gulf. The following table shows the 

 arrangement of the species from another point of view omitting refer- 

 ence to the range of the species outside of the thirteen rivers included 

 in this table: 



Known only from the 



Ohio 



Alabama 



Species. 

 30 

 17 



Known only from the 



Tennessee 

 Illinois . . 



Species. 

 16 

 14 



