158 FISHES OF ILLINOIS 



occurred to us from first-class rivers but once in 293 collections, 

 and not at all from stagnant waters of any description. It has 

 a very decided preference for a clean bottom, it we may judge 

 from the 38 collections of the species made for which data of this 

 description were recorded, its frequency coefficient for this class of 

 situations being 3.2. It is a noticeable fact, however, that the 

 species nevertheless occurs within the lower Illinoisan glaciation, 

 particularly in the headwaters of the Kaskaskia in the northern 

 part. 



Females apparently near spawning condition have been 

 taken by us in late May and early June. The sexual differences 

 are not well marked, and the males have neither tubercles nor 

 brilliant colors in spring. 



Genus PHENACOBIUS Cope 



SUCKER-MOUTHED MINNOWS 



Body elongate, little compressed; mouth inferior, the lower lip thin 

 mesially and enlarged on each side into a fleshy lobe; upper jaw protractile; 

 no barbel; teeth 4-4, hooked and with grinding surface; intestine short; 

 peritoneum silvery; dorsal rays 8; anal 7; scales 45 to 60; lateral line com- 

 plete. Length 3 to 4 inches, the adults having much ^ the appearance of 

 young suckers. About 5 species known, confined chiefly to the central and 

 southeastern United States. 



PHENACOBIUS MIRABILIS (Girard) 



SUCKER-MOUTHED MINNOW 

 (Map XLVII) 



Girard, 1856, Proc. Ac. Nat. Sci. Phila., 191 (Exoglossum). 



J. & G., 205; M. V., 63; J. & E., I, 303; N., 46 (teretulus liosternus); J., 61 (scopife- 

 rus); F. F., I. 6, 88 (scopiferus) ; F., 76; L,., 18. 



The inferior sucker-like mouth, thick lips, small scales, and black spot 

 at base of caudal fin in this species will, taken together, distinguish it from all 



other minnows found in Illi- 

 nois. Length 33^2 inches: 

 form of body much as in the 

 common red-horse (Moxos- 

 toma aureolum), — the inferior 

 mouth and fleshy lips adding 

 to the resemblance, — fusi- 

 form, the back moderately 

 Fig. 39 elevated, depth 4.6 to 5 in 



length; caudal peduncle 

 about equal to head, its depth 2 to 2.2 in its length. Color olivaceous, the 

 sides with a dull silvery luster overlying a dusky lateral shade; a distinct 

 black caudal spot and a narrow vertebral streak, golden in life, when the 



