18 



Notropis jejunus (Forbes). 



A large pale silvery minnow, without conspicuous color markings; Id the rounded form of 

 the scales agreeine with Hvhognathus nuchalis. 



Specimens found in 49 of our collections, made principally in the Illinois Rlvpr and to the 

 northwestward. Found a few timps in tributaries of the Wabash and Ohio rivers in 

 southern Illinois, once in Lake Michigan, and once in Logan county. 



Notropis atherinoides Rafinesque. ' 



The first fish of the genus to be named. A long thin silvery minnow, with long lower jaw 

 and oblique mouth. Lateral line decurved. Specimens from Lake Michigan with a very 

 black stripe on the side. 



This species and the three following are found throughout Illinois, but are not sharply 

 separated in our preliminary determinations, if, indeed, that is possible. 



Notropis urge (Cope). 



Differs from N. atherinoides in the larger eye and almost straight lateral line. 



Notropis dilectus (Girard) . 



Depth greater and mouth smaller than in iV. atherinoides. 



Notropis Tuhrijrons (Cope). 



Notropis umhratilis ((rirard). — Red-fin. (123) 



Body short and compressed; very fine scales before the dorsal; anal fin long (rays ID* 

 The males are hierhly colored; body of variegated bluish, greenish, purple, and opalescent; 

 fins deep red in spring. 



Pound everywhere, but occurs most commonly in large creeks and small rivers, being 

 most abundant southward. The several varieties of this species which occur in the State 

 have not yet been carefully discriminated in our collections. 



Ericymha buccata Cope. 



Body cylindrical: in general appearance like the straw-colored minnow (iV. blennius). 

 Lower jaw much enlarged, with mucous cavities which appear on the outside as vitreous 

 streaks; eyes directed slightly upward, giving to the fish a peculiar watchful expression. 



Abundant in the upper Wabash basin; taken also from the Iroquois basin near Watseka, 

 Its occurrence in the latter place due probably to its crossing the low divide near Hoopeston 

 by aid of high water or the changing of water courses through artificial drainage. 



Phenacobius niirabilis (Girard). — Sucker-mouth Minnow. 



Mouth inferior; upper lip thickened outwardly and sucker-like; form of body similar to 

 that of the common red-horse. This species and P. scopt/er (Cope) are not readily distin- 

 guishable in our collections. The first is described with 48 to 52 scales in the lateral line, 

 the second with 43 to 45. 1 his being the usual basis of separation. Our specimens are inter- 

 mediate, having from 43 to 50 scales. We have therefore called themcollectively P.mirabilia. 



Taken in 140 localities, in moderately swift water, throughout the State. 



Rhinichthys atronasus (Mitchill). — Black-nosed Dace, 



In general appearance \ery much like the Stone roller (Campos^oma o»»oma?Hm), but 

 with a barbel at each corner of the mouth; the males diflferiug in having a stripe on the side 

 which varies with seasons from crimson to pale salmon-color. 



Found in rapid streams, widely distributed throughout the State, but nowhere common. 

 Not yet taken from tributaries of the Wabash or of Lake Michigan. 



KEY TO ILLINOIS SPECIES OF THE GENUS HTBOPSIS. 



a. Small slender species with mouth inferior; usually silvery. 



b. Barbels 4 H. tbt&anskcs. 



bb. Barbels 2. 



c. Eye small, its length leas than ^ that of head. 



