34 THE FISHES OF OHIO. 
Genus: CATOSTOMUS. 
Key to Species. 
AY: Head transversely convex above, the orbital rim not elevated, scales in lateral line 
60 or more. 
B. Scales in lateral line about too.— catostomus. 
BB. Scales in lateral line 64 to 70.— commersonit. 
AA. Head broad, depressed, and transversely convex between the orbits; scales in lateral 
line, 48 to 55. NIGVICANS. 
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 2% 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-SCALED SUCKER. 
Head rather conical, 44% in length of body, 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. Jength 15 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 1899, at the following places: Ohio river and Ice creek at 
