124 fishes of illinois 



Genus OPSOPCEODUS Hay 



Body fusiform, somewhat compressed; mouth extremely small, 

 terminal; upper jaw protractile; no barbels; teeth 5-5 or 4-5, with 

 edges serrated and no grinding surface, the tips hooked; intestine short ; 

 peritoneum white; dorsal rays 7 to 10; anal rays 7 or 8; scales 37 to 42; 

 lateral line complete or imperfect. Size very small, 2h inches. Species 

 3 or 4; confined to the Mississippi Valley and the eastern United States. 



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Fig. 2 7 



OPSOPCEODUS EMILIA Hay 



Hay, 1880, Proc. U. S. Xat. Mus., 507. 



Forbes in J. & G., 247 (Trycherodon megalops) ; M. V., 68; J. & E., I, 248 (megalops) 

 F., 74; L., 15 (emiliae and megalops). 



The very small and upturned mouth, the black spot on the posterior 

 rays of the dorsal fin, and the incomplete lateral line of this species serve 

 to distinguish it readily from all other minnows found in our range. 

 Length usually less than 2^ inches; body moderately elongate, com- 

 pressed, the back perceptibly elevated, the profile a more or less even 

 incline from a point over the tips of the reflexed pectorals; depth 4. 1 to 

 4.8 in length; caudal peduncle slender, longer than head, its depth 2-2 

 to 3.2 in its length, not usually, however, over 2.5. Color light olive, 

 yellowish, the scales except on and very near belly conspicuously dark- 

 edged;* a narrow dark lateral band, extending forward across opercle 

 and through eye to end of snout, becoming faint anteriorly; no distinct 

 caudal spot, but sometimes, in highly colored males, an indistinct ver- 

 tical bar at base of caudal; fins of females plain, or, at most, the dorsal 

 with faint traces of dusky on anterior third; breeding males with the 

 snout and chin thickly studded with minute tubercles, and with a large 

 blotch of dusky covering almost entire dorsal fin except a patch at base 

 and another at tip of fin ; a second blotch of dusky at back of fin in some 

 males, situated about half way up from base and crossing last three rays; 

 other fins plain. Head small, 4.2 to 4 . 5 in length ; width of head 1 . 7 to 



* No other species of Cyprinidcv found in this state has the cross-hatching more 

 distinct or extending farther below the lateral line, typical specimens having al- 

 most the entire bodv so marked. 



