DeRyke and Scott 15 



Collection 16 



June 30, 1920. Rushes and Chara; sand and gravel; four feet; clear; 

 cloudy; 8:30 a. m. ; seine. 



Fishes examined in this collection 



Etheostoma caprodes Raf. (log perch). 



70 mm. 14 chironomidae larvae; 1 cladoceran. 



77 mm. 49 Hyalella knickerbockeri ; 2 chironomidae larvae; a small piece 

 of stem resembling Equisetum. 

 Labidesthes sicculus Cope (skipjack). 



70 mm. A portion of macerated winged insect, unable to identify. 

 66 mm. 2 adult insects, very small and torn so much I was unable to 

 identify them. 



Collection 17 



June 30, 1920. Potamogeton and Chara; gravel; four feet; rippling; 

 cloudy; 9:30 a. m. ; seine. 



Fishes examined in this collection 



Perca flavescens Mitchill (yellow perch). 



112 mm. 1 ephemerida larvae and a mass of Potamogeton. 

 80 mm. 1 Hyalella knickerbockeri; several fragments of insect larvae, 



unable to identify. 

 66 mm. Macerated insect larvae, unable to identify. 



Collection 18 



June 30, 1920. Algae, Chara, Ceratophyllum, Potomogeton, and dense 

 growth; soft mud; two and one-half feet; clear; cloudy; 10:45 a. m.; seine. 



Fishes examined in this collection 



Perca flavescens Mitchill (yellow perch). 



89 mm. 13 snails; 1 odonatid nymph; 2 ephemerida larvae; 1 tricopteron 

 larva case; 4 Chironomus larvae; 3 Hyalella knickerboekei'i; 2 

 haliplidae larvae. 



127 mm. 2 Hyalella knickerbockeri ; 1 haliplidae larva ; 1 small cray- 



fish 15 mm. long. 



73 mm. 5 Hyalella knickerbockeri; 2 Chironomus larvae; 118 Sida 



crystallina; numerous cladocera eggs. 

 116 mm. Portions of a small cray-fish and 1 Chironomus larva. 



95 mm. 1 fish egg; 1 Chironomus larva; nematoda; debris. 

 113 mm. 31 tricoptera with cases; 1 snail; 1 Chironomus larva; small 



amount of plant tissue; 1 ephemerid nymph. 



128 mm. A very small amount of fish flesh. 

 75 mm. 2 Chironomus larvae. 



74 mm. 1 fish egg; portion of Haliplus beetle larva; the head of a 



Chironomus larva. 



