34 THE FISHES OF OHIO. 



Genus : Catostomus. 

 Key to Species. 



A. Head transversely convex above, the orbital rim not elevated, scales in lateral line 

 60 or more. 

 B. Scales in lateral line about 100. — catostomus. 



BB. Scales in lateral line 64 to 70.— • commersonii. 



AA. Head broad, depressed, and transversely convex between the orbits ; scales in lateral 

 line, 48 to 55. nigricans. 



Catostomus catostomus (Forster). Northern Sucker. 



This species can at once be distinguished from the others of the genus 

 occurring in Ohio, by the great number of scales in the lateral line, 95 to 114. 

 About 29 cross rows between dorsal and ventrals. Head broad above, pointed 

 in front ; snout a little longer than remainder of head and much overhang- 

 ing the mouth. Body rather slender and somewhat terete. D. 10 ; A. 7. 

 Color, above, smoky gray ; below, white. Length o.y z feet. 



This species is one of northern distribution, probably not 

 occuring in the tributaries of the Ohio. "Quite abundant in 

 Lake Erie," Jordan (Ohio Rept. ), 1878; Lake Erie, Henshall, 



1889. 



Catostomus commersonii (Lacepede). Common Sucker; 

 Fine-scaeed Sucker. 



Head rather conical, $% in length of bod)', flattish above, but not con- 

 cave between the eyes. Body moderately stout, terete or sub-terete, becom- 

 ing heavier at the shoulders with age, depth 4 to 5 in length. D. 11 or 12 ; 

 scales small, 10-64 to 70-9. Color olivaceous, tending toward blackish on 

 back and lateral line. Length 18 inches. 



One of the commonest species in the state, found in abund- 

 ance in nearly every stream. Recorded for the state by Kirt- 

 land for the Big Miami, and small brooks of northern Ohio ; 

 " Swarming in every pond and stream in Ohio," Jordan (Ohio 

 Rept.); Hamilton County, " Everywhere abundant," Henshall, 

 1888; Lorain County, "Very common in all our waters," 

 McCormick, 1892 ; recorded by Kirsch for nearly every locality 

 seined in the Maumee River System, 1893 ; taken by Mr. Wil- 

 liamson and myself in every stream in Franklin County, 1897 > 

 in every stream of the Big Jelloway Creek System in Knox 

 County, Parker, Williamson and Osburn, 1898 ; taken by myself 

 in 1S99, at the following places : Ohio river and Ice creek at 



