MOXOSTOMA RED-HORSE 89 



the food of specimens taken from the Illinois River at Peoria 

 was mainly distillery slops entering the streams from the adja- 

 cent distilleries. The latter element was insignificant, however, 

 in total amount, insects and mollusks making fully 95 per cent, 

 of the stomach contents studied, mollusks being nearly twice 

 as abundant as insects. In consequence of the manner in which 

 the food is collected from the bottom, considerable quantities 

 of mud are, of course, swallowed with it. 



These fishes are caught mainly with seines and pound-nets, 

 but they also bite readily at the hook. 



KEY TO THE SPECIES OF MOXOSTOMA FOUND IN ILLINOIS 



a. Folds of lower lip more or less broken up into papillae. 



b. Head short, 4% to 5% in body; lower lip truncate behind, mouth small; de- 



veloped dorsal rays 12 or 13 breviceps. 



bb. Head longer, 3% to 4% in body; halves of lower lip meeting in a sharp angle, 



mouth large; developed dorsal rays 14 to 16 anisurum. 



aa. Lips strongly plicate. 



c. Head 4 to 4% in body; halves of lower lip meeting in a rather wide angle, 



mouth large; developed dorsal rays 12 to 14 aureolum. 



MOXOSTOMA ANISURUM (RAFINESQUE) 



WHITE-NOSED SUCKER 



(MAP XX) 



Rafinesque, 1820, Ichth. Oh., 54 (Catostomus). 



G., VII, 20 (Catostomus carpio); J. & G., 139 (carpio); M. V., 47; J. & E., I, 190; 

 N., 49 (Teretulus carpio); J., 63 (Myxostoma carpio); F., 80 (carpio). 



Body stout, heavy forward, deep and compressed, the back elevated, 

 rather humped in front of dorsal in old specimens; depth 3.3 to 4.1 in length. 

 Size large, reaching a weight of 5 to 10 Ib. Color pale, silvery, darker above, 

 nose and chin whitish; dorsal and caudal with some dusky, lower fins white 

 or light reddish. Head broad and short, squarish 

 in cross-section in region of orbit, its length 3.5 to 

 4.3, width 5.2 to 6.5, depth 4.6 to 5.5 in head; inter- 

 orbital space flat, 2.2 to 2.6 in head; snout rather 

 long, 2.1 to 2.6 in head; its tip squarish, little de- 

 curved, the profile nearly straight to its tip when 

 the mouth is closed; mouth rather large, the upper 

 lip thin, plicate-papillose, the lower thicker, its folds 

 broken into evident papillae, the halves meeting at a FI 21 



sharp angle; eye rather large, slightly back of middle Li of G Moxostoma 

 of head, 4 to 6.4 in its length. Dorsal fin long, its anisurum 



rays about 15 (14 to 17), the longest about % 



length of base of fin, the free margin straight; lower fins long, pectorals reach- 

 ing % of distance from pectoral to ventral basis; upper lobe of caudal a little 

 longer than lower. Scales 6, 42-45, 6; lateral line complete, somewhat 

 flexuose, but nearly straight. 



15 F 



