494 
II. Bottom Fauna of the Lakes of the Illinois Valley, Copperas 
Creek Dam to Lagrange, 1914—1915 
1. DeErer, Borrom-Lanp Type (CLEAR—Mup, LIvERPooL, 
Tuomeson, DocrisH, SANGAMON Bay) 
Crear Lakes, Sept. 1, 1915. 
Botrom Fauna 
8 CoL~LEecTIoNS, DrepTH, 8 To 8.5 rr. No VEGETATION 
Number per square yard 
Pounds per acre 
Campeloma subsolidum 1.2 3.6 
3.9 17.1 
Vivipara contectoides 2.7 13.5 
Musculium transversum 371.8 185.5 
404.9 186.8 
Pisidium sp. 33.1 den 
Leeches (small spp.) 16.0 2.7 
Chironomid larvae (large spp.) 13.0 37.7 8.7 17 
Small Oligochaeta 8.7 0.3 
Total 446.5 215.6 
CieaR—Mup Laxr, Sept. 1, 1915. 
12 Cottections, DEPTH, 1 To 6 FT. 
(Some vegetation at two shallow stations) 
Bottom FAuNA 
Number per square yard 
Pounds per acre 
Campeloma subsolidum 8.4 25.2 
27.7 121.7 
Vivipara contectoides 19.3 96.5 
Musculium transversum 219.1 109.5 
Pisidum sp. 30.0 249.2 1.2 110.7 
Musculium jayanum 0.1 trace 
Leeches (small spp.) 42.1 Tal 
Chironomid larvae (large spp.) 15.8 58.7 10.5. ply 
Chironomid larvae (small spp.) 0.8 (ae 
Total 335.6 250.1 
