140 FISHES OF ILLINOIS 



dark-edged, those below lateral line on posterior half of body and 

 caudal peduncle rather sparsely specked with black; top of head and 

 muzzle darkish; fins all plain; dorsal, caudal, and pectorals pale rosy 

 in spring males, in which also the head is covered with very fine 

 tubercles that suggest a sprinkling of white dust. Head long, broad, 

 flatfish above, 3 . 5 to 4 in length ; its width 1 . S to 2 . 1 in its length ; inter- 

 orbital space 3 to 3 . 6 ; eye 3 to 3 . 8 ; nose long and muzzle decurved, the 

 snout usually greater than eye, 2 . S to 3.3 in head ; mouth rather large, 

 nearly horizontal and inferior, the tip of the upper lip below the level of 

 the lower margin of the orbit ; lower jaw included ; isthmus less than pupil. 

 Teeth 1, 4-4, 1; intestine a little less than head and body; peritoneum 

 silvery, with sometimes a very few dark specks. Dorsal fin with 8 rays 

 (sometimes 9), quite uniformly set slightly behind ventrals; longest 

 dorsal ray \ of head in adults, 1.1 to 1.4; anal rays 8 (occasionally 9); 

 pectoraks about j to ventrals, 1 . 3 to 1 . 6 in head; ventrals to or past vent. 

 Scales 6, 34-37, 4, smaller and crowded anteriorly, 16 to 18 rows before 

 dorsal; lateral line complete, decurved anteriorly. 



This is a western species, the range of which to the eastward 

 terminates in Illinois. It extends westward through Iowa to east- 

 ern Colorado, being most abundant, so far as known, in muddy 

 streams of the plains from the Des Moines to the Platte. It occurs 

 also in tributaries of the Missouri in Missouri and Iowa. Only 2 

 of the 32 localities from which it has been recognized in this state 

 lie outside the Mississippi drainage, and both of these are in the Wa- 

 bash Valley, one near the mouth of that stream and the other on 

 the extreme headwaters of the Embarras. It seems to be essen- 

 tially a species of small rivers and creeks, our ratios of occurrence 

 in the larger rivers and in lakes and ponds being quite insignificant. 



Gravid females have been found by us in the latter part of June. 



NOTROPIS ILLECEBROSUS (Girard) 



Girard, 1856, Proc. Ac. Nat. Sci. Phila., 194 (Alburnops shumardi), 

 J. & G., 192 (Minnilus), 194 (M. scabriceps); M. V., 57 (boops); J. & E., I, 268; L., 

 17 (shumardi). 



The very large eye, large oblique mouth, and broad head of this 

 species distinguish it from all other Illinois minnows of its genus. 

 Length 3 inches, body moderately compressed, the back little ele- 

 vated; depth 4.5 to 5.4 in length; caudal peduncle rather slender, its 

 depth 2.1 to 2.7 in its length. Color olivaceous or straw, the sides little 

 silvery; a dark lateral band, continued forward through eye to end of 

 snout, tipping the chin; tins all plain. Head broad and flat above, 3.8 

 to 4. 1 in length ; width of head 1 . 8 to 2 . 1 ; interorbital space 2 . 8 to 3 .2 ; 

 r i very large, ', to | L mger t han nose or maxillary, 2.4 to 2.8 in head ; 

 nose 2.9 to 3.6, blunt and shorter than the very large eye; muzzle not 

 decurved; mouth large and quite oblique, the tip of upper lip above level 



