138 Illinois State Laboratory 0/ Natural Itistorij. 



blackish bars gradually appeared. Mr. Bartlett tells me that he 

 has transplanted perch to this locality, — a fact which probably 

 accounts for the abundance of the fish in Libby Lake. 



Localities: Libby Lake, Dead Man's Slough, Long Lake, 

 Broad Lake. 



Sand Darter {Etheostoma jessi<i\ Jor. & Brayt., var. asprigene^ 

 Forbes). 



Judging by the number of specimens of this little fish 

 taken, it is not common here, although parts of Willow Slough 

 are well suited to it. 



Four examples, Willow Slough; one large brightly colored 

 example, Broad Lake; one example, Lily Lake. 



Sand Darter {Etheostoma phoxoceplialnin, Nelson). 



Occasional in Wood Slough. Excepting a single example 

 from Willow Slough, it was not seen elsewhere. 



Blackis-ded Darter (Etheostoma aspro, Cope & Jor.). 



One small example approaching E. pJioxocephalinn in 

 colors, was taken in Wood Slough, July 30. 



Log Perch (Etheostoma caprodes^ Raf.). 



This was the most abundant darter collected. It was 

 quite common in Willow Slough, Long Lake, Broad Lake, and 

 Wood Slough, 



Johnny Darter (Etheostoma nigrum^ Raf.). 



An immature example from Willow Slough was the only 

 one seen. 



Family Centr.vrchid^. (Sunfishes). 

 Large-mouthed Black Bi\s,^(Micropterus salmoides, Luc). 



The young of this bass were moderately common in all 

 the sloughs and creeks. Examples of considerable si/e were 

 occasionally taken, showing that this species does not neces- 

 sarily leave the sloughs after spawning. One example brought 

 in by the net must have weighed seven pounds or more. The 

 smaller examples, which are of interest as in all probability 

 the young of the season, ranged from 2 to 3 inches in length. 

 Between these and the larger ones were various intermediate 

 si'/es representing probably three or four generations. 



