449 



Gerridae : Mctrobatcs licspcriiis Uhl., adults and 



nymphs abundant. 

 Veliidae: R'liai/oz'cUci obcsa Uhl., adults and 

 nymphs abundant. 

 Neuroptera. Sialidae : Corydalis corniita (Linn.), small larvae 



common. 

 Sialis iiifiiiuata Newm., larvae. 

 Trichoptera. Hydropsychidae : Hydropsychc sp., extremely 



common with their nets. 

 Coleoptera. Hydrophilidae : Tropistcrnus g labor (Hbst.), 



adults. 

 Bcrosus striatus (Say), adults. 

 Enochrus ochraceus (Melsh.), adults. 

 Helmidae : Stenelmis sp., adults and larvae com- 

 mon. 

 Diptera. Chironomidae : Chiroiiouius sp., small larvae. 



Station ip. — One and one-half miles east of Homer Park, August 

 22. Great beds of water-willow, Dianthera, in the stream. Collections 

 were made principally in these dense beds. 



Ephemerida. Ephemeridae: Hcxageuia bilineata Say, naiades. 

 Odonata. Aeschnidac : Gomplms sp., naiades. 



Coenagrionidae : E'nallagina sp., naiades. 

 Hemiptera. Belostoniatidae: Belostoma flumineum Say, adults 



and nymphs. 

 Gerridae : Gcrris marginatus Say, adults. 



Tfepobatcs pictiis (H. S.), adults and nymphs. 

 Mesoveliidae: McsovcUa mulsanti White, adults 



and nymphs. 

 Hydrometridae: Hydromctra iiiartini Kirk., adults 

 and nymphs. 

 Coleoptera. Helmidae : Hclmis vittata Melsh., adults. 



Stenelmis sp., adults and larvae abundant. 

 Dascyllidae: Cyplion sp., or Scirtes sp., larvae 

 very common. 

 Diptera. Chironomidae: C/i/roHo;)(;(.f sp., larvae. 



Cambarus sp.. very abundant. Small catfish and sunfish are very 

 numerous. 



Station 20. — Two miles southwest of Fithian, August 22. Here 

 the stream is nearly choked with water-willow, Dianthera, with some beds 

 of Elod'ca. 



Plccoptera. Perlidae: Perla sp., naiades. 



Ephemerida. Ephemeridae: Hcxagcnia bilineata Say, naiades. 

 Polymitarcys albus (Say), naiades. 

 Caenis sp., possibly diminuta Wk., naiades. 

 Baelis sp.. naiades. 

 Heptagcnia sp., naiades. 



