447 



Station 14. — Benchmark 666, south of St. Joseph, August 9. The 

 stream here is comparatively clear. There are some small masses of 

 sludge but the whole stream is virtually choked with great masses of 

 the water-net. Hydrodictyon. In the water, small areas of Sagittaria 

 are growing, indicating a clearing up of polluted conditions. 



Hemiptera. Corixidae: extremely abundant, mostly adults but 



including many large nymphs. 



Diptera. Chironomidae : Procladius sp., larvae. 



Chirononuis sp., larvae, a few only. 



No Ephemeridae, Odonata, or Coleoptera were taken here on this 

 date (compare with Station 28 later). A few sludge- worms were 

 found. 



Station 15. — The Shakerack Bridge, one and one-half miles west 

 of Tipton, August 9. The bridge is at the west end of a small wood- 

 land. The stream here is comparatively deep but dirty. No algal or 

 other plant life occurs. 



Ephemerida. Ephemeridae : Callibactis sp., possibly fcrnigiiwa 



Walk., fully grown naiades. 

 Odonata. Aeschnidae : Goinf'liHs sp.. small naiades of a bur- 



rowing species. 

 Hemiptera. Corixidae : common, mostly young nymphs, al- 



though a few adults were found. 

 Diptera. Chironomidae: Chironomus sp., few lar\ae. 



Sludge-worms still common. 



Station 16. — The Stone bridge, one-half mile east of Sidney, .\ugust 

 9. The stream here appears practically normal. Great beds of water- 

 willow, Dianthcra, almost choke the stream. A large and varied aquatic 

 insect fauna occurs here, including abundant Odonata and ephemerid 

 naiades. 



Ephemerida. Ephemeridae: Hcxaqcuia biliiicata Say, naiades. 

 Hcptagcnia sp., fully grown naiades. 

 Cacnis sp., possibly diniiiiiita W'k., naiades. 

 Callibactis sp., naiades. 

 Odonata. Libellulidae : Libcllula piilchcUa Dru., naiades, 



Coenagrionidae : Ischnnra vcrticalis (Say), na- 

 iades. 

 Enallagiiia sp., naiades. 

 Hemiptera. Corixidae: common. 



Notonectidae: Notonccta variabilis Ficb., several, 

 adults and nymphs. 

 Bucnoa platycncmis Ficb., adults and nymphs. 

 B. margaritacca Bueno, adults. 

 Gerridae: Mctrobatcs hrspcrins Uhl., adults and 

 nymphs. 



