NOTROPIS 143 



Although reported from South Carolina, it is essentially a 

 northern species, ranging from New England, Quebec, and the 

 Lake of the Woods through the Hudson and Great Lake basin to 

 the streams of the Missouri in Minnesota and the Dakotas. It 

 is abundant in the Great Lakes and at the mouths of the rivers 

 opening into them. In Ohio and in Indiana, as in Illinois, it is 

 generally confined to the northern parts of the state. 



It is a typical minnow in its food, depending on insects, 

 crustaceans, and vegetation, the latter partly algae of the fila- 

 mentous forms and partly fragments of aquatic plants. This 

 general statement does not indicate the variety of its resources 

 or the seeming indifference with which it will fill itself with one 

 or the other kind of food which it finds most abundant. One of 

 our specimens, for example, had eaten nothing but algae, and 

 these plants made three fourths of the food of another. Three 

 had eaten only insects, and these were 90 per cent., or more, of 

 the food of three others. Two had taken nothing but Entomos- 

 traca, all a species of Cypris feeding upon the bottom. Four had 

 filled themselves with various vegetable structures, and 90 per 

 cent., or more, of the food of three others consisted of like 

 material. Three out of four of these minnows, taken at Nipper- 

 sink Lake in May, had eaten only terrestrial snout-beetles 

 (Rhynchophora) , whose occurrence in the water was a matter 

 of chance. The larvae of day-flies (Ephemerida) made more than 

 three fourths of the food of three other specimens. One had 

 eaten a small fish, and traces of like food were found in another. 



NOTROPIS LUTRENSIS (BAIRD & GIRARD) 



RED FIN 

 (MAP XXXIX) 



Baird & Girard, 1853, Proc. Ac. Nat. Sci. Phila., 397 (Leuciscus). 



G., VII, 258 (Leuciscus); J. & G., 172 (Cliola iris and C. jugalis), 174 (C. gibbosa 

 and C. forbesi), 175 (C. lutrensis), 176 (C. suavis), 177 (billingsiana); M. V., 

 57; J. & E., I, 271; J., 57 (Cyprinella forbesi); F., 77; L,., 17. 



This little fish is especially distinguished among Illinois Cyprinidce by 

 the brilliancy of its color and by the depth and thinness of its body, fully 

 grown specimens not seldom having the depth in length less than 2%. It is 

 very nearly allied to the next species, N. whipplii, compared with which it 

 seems to be merely a more specialized form, the two sometimes intergrading 

 in an obscure and very puzzling way. It may, however, be distinguished 

 from the next species, as a rule, by its greater depth when adult, by the 



