445 



live in this water but no fish were found, although they probably come in 

 from Spoon River at high water. Insect life was surprisingly abundant 

 and included many water-breathing species. 



Hemiptera. Belostomatidae : Bclostoma flumincum Say, nymphs 



of all sizes, adults. 

 Gerridae : Gcrris marginatits Say, adults. 

 Mesoveliidae : Mcsovclia inulsanti White, adults 

 common, some winged. 

 Coleoptera. Dytiscidae: Laccophiliis niaciilosiis ( Germ.), adults 



and larvae. 



Bidcssus lacustris (Say), adults. 

 Gyrinidae : Dinciites amcricamis Say, adults. 

 Hydrophilidae: Tropistcnius glahcr (Hbst.), 

 adults and larvae. 

 T. lateralis (Fabr.), adults. 

 Hcloplwrus lincattts Say, adults. 

 Bcrosus pcregrimus (Hbst.), adults. 

 Eiwchnis ochracciis (Melsh.), adults. 

 Paracyinus subcupreus (Say), adults. 

 Helmidae : Steuclmis sp., one adult. 

 Diptera. Chironomidae : Cliiroiiomns z'iridicolUs v. d. \\'., 



extremeJv abundant, larvae. 

 Tabanidae : Tabaiius sp., one larva. 

 The great abundance of water scavenger-beetles, Hydro]ihilidae. and 

 Chlrononius viridicoUls indicate a polluted but scarcely septic condition 

 of the water. 



Station ii. — Spoon River, 100 yards above the union with Salt 

 Fork, July 23.. Studied as a check on the main stream. The stream here 

 is ver)' muddj' but the bottom is hard, comi)osed of gravel, small crushed 

 stones, and broken shells. The stream is almost choked with great beds 

 of water-willow, Dianthcra amcricana. 



Ephemerida. Fjihemeridae : Hcxagcnia bilineata Say, large nai- 

 ades. 

 Odonata. .Aeschnidae : Anax jumus (Dru.), young naiades. 



Libellulidae : Plathemis lydia (Dru.), adults. 

 Coenagrionidac : Ischnitra vcrticalis (Say), adults. 

 Enallagma cxsulans (TTag.), adults and naiades 



abundant. 

 E. antciinatum (Say), naiades. 

 Hemiptera. Corixidae : unidentified. 



Gerridae: Trcpobatcs pictus (H. S.), adults and 

 nymphs. 

 Neuroptera. Sialidae: Sialis infuiuata Newm., larvae of various 



sizes. 

 Coleoptera. Dytiscidae: LaccophUiis maculosus (Germ.), 



adults. 



