86 FISHES OF ILLINOIS 



and the relatively small number of pharyngeal teeth, the lower 

 of which are very much thickened, with expanded crowns, con- 

 stitute a crushing and grinding apparatus which strongly suggests 

 a prevailing molluscan diet. The gill-rakers are less effective 

 than those of the red-horse, indicating a smaller ratio of crus- 

 tacean food. 



The species spawns in April or May, preferring for the pur- 

 pose riffles or swift-flowing water to quiet pools. 



Though bony, these fishes have a sweet, firm, and flak} 7 

 flesh, and furnish a food of considerable importance in many 

 parts of the country. They are frequently salted for winter 

 use, and are sometimes sold in our local markets under the name 

 of " family whitefish." They are taken with seines, traps, and 

 gill-nets, bite readily at the hook baited with worms or bits of 

 crawfish, and are sometimes caught by boys in spring with 

 snares fastened to poles. 



CATOSTOMUS NIGRICANS Le Sueur 



hogsucker; hogmolly; stone-roller 



(Map XIX) 



Le Sueur, 1817, J. Ac. Nat. Sci. Phila., 102. 



G., VII, 17; J. & G., 130; M. V., 46; J. & E., I, 181; N., 48 (Hypentelium) ; J., 64; 

 F., 81; F. F., II. 7, 445 (Hypentelium); L., 12. 



Body moderately elongate, subcylindrical, heavy forward, much tapered 

 posteriorly, depth 4.6 to 5.1 in length. Size rather large, reaching a length 

 of 2 feet. Color olivaceous, with brassy luster on sides; belly satiny white; 

 back and sides in younger specimens with 4 rather broad and distinct 

 oblique bars of dark color, one half way between occiput and dorsal, one 

 just behind fin, and one half way between back of dorsal and base of caudal, 

 these bars becoming faint or obsolete in adults; lower fins reddish, with some 

 dusky shading, appearing as faint mottlings on pectorals and ventrals. 

 Head very large, the frontal region broad and foreshortened, length of head 

 3.6 to 4.5, width 4.7 to 5.8, depth 5.9 to 6.6 in body; interorbital space trans- 

 versely concave, 1.9 to 2.5 in head; snout long and strongly decurved, 1.8 

 to 2.2 in head; mouth wholly inferior, the lips very thick and strongly 

 papillose, the upper almost as thick as the lower, with 8 to 10 series of papillae; 

 lower lip less incised behind than in Catosto?nus proper; eye moderate, 4.8 

 to 6 in head, over 5 in adults. Dorsal fin with 10 or 11 rays, rather low, the 

 longest ray scarcely equaling the length of the base of the fin; pectorals 

 very long, reaching % to z /i of distance to ventrals. Scales rather large, 

 7, 46-51,6, somewhat smaller on breast and belly, but not crowded forward 

 on sides or in predorsal region: lateral line complete, almost straight. 



This peculiar sucker is distributed throughout the Great 

 Lake region and along the Atlantic slope as far as the Carolinas, 



