MOXOSTOMA RED-HORSE 89 



distillery slops entering the streams from the adjacent distilleries. 

 The latter element was insignificant, however, in total amount, in- 

 sects and mollusks making fully 95 per cent, of the stomach contents 

 studied, mollusks being nearly twice as abundant as insects. In con- 

 sequence of the manner in which the food is collected from the bot- 

 tom, 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 Species of MOXOSTOMA found ix Illinois 



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



b. Head short, 4k to 5 J in body; lower lip truncate behind, mouth small; 



developed dorsal rays 12 or 13 breviceps. 



bb. Head longer, 3^j to i^ in body; halves of lower lip meeting in a sharp angle, 

 mouth large; developed dorsal raj-s 14 to 16 anisurum. 



aa. Lips strongly plicate. 



c. Head 4 to 4-i 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) 



Rafinesque, 1S20, Ichth. Oh., 54 (Catostomus). 



G., VII, 20 (Catostomus carpio); J. & G., 13Q (carpio); M. V., 47; J. Sc E., I, 190; 

 X., 49 (Teretulus carpio); J., 63 (Myxostoma carpio); F., SO (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 tb. Color pale, sih'erv, 

 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; interorbital space flat, 2.2 to 

 2.6 in head; snout rather long, 2.1 to 2.6 in head; 

 its tip squarish, little decurved,the profile nearlv 

 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 Fig. 21 

 evident papillae, the halves meeting at a sharp Lips of Moxosioma 

 angle; eye rather large, slightly back of middle of anisurum 

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



rays about 15 (14 to 17), the longest about | length of base of fin, the 

 free margin straight ; lower fins long, pectorals reaching J 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. 



