ii4 Cincinnati Society of Natural History. 



SOME OBSERVATIONS ON OHIO FISHES. 

 By Dr. James A. Henshall. 



The State of Ohio is drained by two great water systems — the 

 St. Lawrence River and the Ohio River. A broad dividing ridge, 

 separating the waters of the two systems, begins in Ashtabula 

 County, in the northeast corner of the State, and running west- 

 southwest, extends to Mercer County. Thus the lower two-thirds 

 of the State is in the Ohio Valley, and the upper third in the basin 

 of the Great Lakes. 



The elevation of Lake Erie is 565 feet, and of the Ohio River at 

 Cincinnati 429 feet abjve tide water, the river at Cincinnati thus 

 being 136 feet below the level of Lake Erie. The great water- 

 shed is from 1100 to 1350 feet above sea-level, and is cut through 

 by four wide valleys, the deepest of which, however, is probably 

 not less than 250 feet above Lake Erie. Through these valleys 

 flow streams to the north and south. Through the most easterly 

 one Grand River runs to Lake Erie, and the Mahoning to the 

 Ohio River; through the next one flows Little Cuyahoga River to" 

 the north, and the Tuscarawas to the south ; in the next valley are 

 the Black and Killbuck, flowing in opposite courses ; and in the 

 most westerly one the Sandusky, Portage and Maumee flow north- 

 east, and the Wabash to the southwest. Along the summit of the 

 dividing ridge are also lakelets, ponds and marshes. 



The forty thousand square miles of the great State of Ohio are 

 well watered and drained by numerous streams, both large and small. 

 Almost the entire northern boundary of the State is washed by the 

 pure waters of Lake Erie, while the beautiful Ohio, one of the 

 great water-ways of the world, flows along its southeastern border. 



All of these waters are inhabited by fishes of high or low degree, 

 from the monster sturgeon to the liliputian darter an inch in 

 length — one of the smallest vertebrates known. 



There are in the waters of the world nearly ten thousand described 

 species of fishes, fully seventeen hundred of which are found in 

 North America. Of these the fresh waters of North America fur- 

 nish some six hundred species, and the waters of the State of Ohio 

 contain at least one-fourth of this number. The fresh-water fishes" 



