140 FISHES OF ILLINOIS 



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, flattish above, 3.5 to 4 in length; its width 1.8 to 2.1 in its length; 

 interorbital space 3 to 3.6; eye 3 to 3.8; nose long and muzzle decurved, the 

 snout usually greater than eye, 2.8 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 ^7 of head in 

 adults, 1.1 to 1.4; anal rays 8 (occasionally 9); pectorals about % 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, de- 

 curved anteriorly. 



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

 terminates in Illinois. It extends westward through Iowa to 

 eastern 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 recog- 

 nized in this state lie outside the Mississippi drainage, and both 

 of these are in the Wabash Valley, one near the mouth of that 

 stream and the other on the extreme headwaters of the Em- 

 barras. It seems to be essentially 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 (GIRAED) 



(MAP XXXVII) 



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

 J. & E., I, 268 (illecebrosus); 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 elevated; 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, con- 

 tinued forward through eye to end of snout, tipping the chin; fins 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; eye very large, > to Y longer than 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 of lower margin of pupil; maxillary reaching front of 



