103 



affects, however, gravelly spots in muddy streams. It is not com- 

 mon in rivers, but is occasionally taken at the mouths of creeks. 

 It has not been found by us in ponds, but specimens were collected 

 from the small lakes of Illinois. 



93. Pimephales promelas, Kaf . — Fat-head ; Black-headed Minnow. 



The distribution of this fish in the State is somewhat peculiar. 

 The species is altogether absent, as far as our collections indicate, 

 from the prairie streams of Central Illinois. It is not uncommon 

 in small muddy creeks connected with the larger rivers, and occurs 

 occasionally in these latter streams themselves. We have not taken 

 it in lakes or ponds or similar waters, neither has it occurred to us 

 in [llinois south of the latitude of Alton. 



Genus 50. Hybognathus, Agassiz. 



94. Hybognathus nuhilus, Forbes. 



(Bui. II, 56; Alhurnops nubilus; Synop., 167; Cliola nuhila.) 



This minnow has thus far been reported only from Illinois, and 

 has occurred in our collections only from the extreme northern part 

 of the State — from the Kock Eiver and its tributaries. 



95. Hybognathus nuchalis, Agassiz. — Silvery Minnow'. 



Almost strictly a river species, being most abundantly represented 

 in our collections from the Illinois, and next from the Wabash, 

 Ohio, and Mississippi. We have not taken it in any lake or pond 

 outside the great river bottoms, and it has occurred but rarely in 

 creeks. 



Genus 51, Chrosomus, Eaf. 



96. Chrosomus erythrogaster, Agassiz. — Ked-bellied Dace. 



This species has occurred sparingly in our collections but from 

 all parts of the State, both in rivers and small streams. We have 

 not taken it, however, from lakes or ponds. 



Genus 52. Oxygeneum, Forbes. 



97. Oxygeneum pulverulentum, Forbes. 



Only a single specimen of this genus and species is thus far 

 known, and this was taken from the Illinois River, at Peoria. 



Genus 53. Campostoma, Agassiz. 

 93. Campostoma anomalum, Raf. — Stone -roller; Stone-lugger. 



This species is very common in small streams throughout the 

 State, from Galena to Cairo, and occurs occasionally in rivers, but 

 rarely or never in lakes or ponds. 



