CX 11 FISHES OF ILLINOIS 



the minnows, the catfishes (especially the bullheads), the top- 

 minnows, and the sunfishes. 



Ninetjr-seven of our species have been collected in large 

 enough numbers, and from a sufficient variety of locations, to 

 give us data for comparison with reference to the general charac- 

 ter and size of the water bodies which they prefer; 62 species 

 furnish available data concerning the bottom or substratum of 

 these water bodies; and 49 species, data concerning current and 

 rate of flow. The numbers of collections for the various species 

 covered by these figures vary greatly from a minimum of 10 

 collections of a species to a 'maximum of 376. Unfortunately, 

 the larger and more important fishes are commonly represented 

 by the smaller numbers of collections, and statements made 

 concerning these are less likely to be found fairly accurate and 

 generally correct than are those concerning the smaller fishes, 

 represented by larger numbers of collections. 



One available set of our data may best be presented in 

 tabular form, for such use as the student may wish to make of 

 them; and to this table we add, as an illustration of its use, only 

 a few statements concerning the more conspicuous ecological 

 groups of our Illinois fishes. 



By assorting the species according to the size of the ratios 

 of frequency of occurrence for each class of situations distin- 

 guished in this table, we may separate those strongly preferring 

 the given situation from those apparent^ avoiding it. In this 

 way we learn that the species occurring in our collections with 

 disproportionate frequency in the larger rivers of the state are 

 the mud-cat (Leptops olivaris), one of the river carp (carpio), 

 the toothed herring (Hiodon tergistis), and the sheepshead 

 (Aplodinotus) , among the larger fishes; and a small darter 

 (Cottogaster shumardi), the trout-perch (Percopsis guttatus), and 

 a minnow (Hybopsis dissimilis) among the smaller fishes. 



The principal larger fishes of the smaller rivers make a much 

 longer list, comprising the hogsucker, two of the native carp 

 (velifer and difformis) , a species of red-horse (aureolwn) , the rock 

 bass, and the small-mouthed black bass; and the principal 

 smaller species are six darters (Etheostoma zonale, Hadropterus 

 phoxocephalus , H. aspro, JDiplesion blennioides, Etheostoma cceru- 

 leum, and Ammocrypta pellucida), a stonecat (Noturus flavus), 

 and Hybopsis kentuckiensis, and four other minnows, all of the 

 genus Notropis (rubrifrons , gilberti, blennius, and cornutus) — 



