d15 
Foot or THompson LAKE, Mippie, Auc. 14, 1914, In PoTAMoGETON PECTINATUS 
Weep Fauna, Upprr 9 INcHEes (Depru, 4.5 FT.) 
No. per sq. yard Pounds per acre 
Amnicola limosa 6,000 228.0 
Physa (small spp.) 960 52.8 320.4 
Valvata spp. 720 39.6 
Pelocoris femoratus 60 57.0 
Agrionid nymphs 480 240.0 
Caenis sp., nymphs 480 38.4 833.4 
Chironomid larvae (small spp.) ~ 600 402.0 
Hyalella knickerbockeri 2,400 96.0 
11,700 1,153.8 
IV. Bottom and Weed Fauna, Littoral Zone of Glacial Lakes 
of Northeastern Illinois, 1916 
1. Botrom Fauna 
Deere LAKE, AuGust—Octoprer, 1916. Borrom Fauna 
7 CoLitections, LirroraL ZonE, 1 To 7 FT. SOME VEGETATION 
Number per square yard| Pounds per acre 
Pisidium spp. 100.5 4.0 
Amnicolidae 254.5 13.9 
Valvatidae 53.2 496.2 29 39.8 
Physa 66.0 3.6 
Planorbis 22.0 15.4 
Leeches, small spp. 12.5 2.1 
Chironomid larvae (small spp.) 59.6 8.3 
Caenis nymphs 3.0 0.2 
Hexagenia, etc. (nymphs) 47.0 42.3 
Caddis larvae (on Chara) 56.5 5.6 
Sand-case caddis larvae 91.0 18.2 
510.7 169.0 
Libellulid nymphs 22.0 11.0 
Agrionid nymphs 28.1 14.0 
Gomphid nymphs 12.5 43.5 
Pelocoris femorata 19.3 18.3 
Hyalella knickerbockeri 156.2 6.2 
Asellus sp. 3.0 0.3 
Total 1,006.9 208.8 
