485 
4 CoLLEcTIONS, 4- To 7-FT. ZONE, AuG. 19, 1915 
CopreraAs CREEK DAM TO ONE MILE ABOVE LIVERPOOL 
Number per square yard | Pounds per acre 
Campeloma subsolidum 160.5 446.7 
Lioplax subcarinatus 60.7 72.8 
Vivipara contectoides 50.0 302.2 | 250.0 814.3 
Vivipara subpurpurea 2.0 10.0 
Pleurocera sp. 29.0 34.8 
Musculium transversum 1212.5 1212.5 606.2 606.2 
Leeches (small spp.) 76.0 12.9 
96.7 15.7 
Chironomid larvae (small spp.) 20.7 2.8 
Total | 1611.4 1436.2 
8 CHANNEL COLLECTIONS, JuLY 31 AND Ave. 3, 4, 1915 
OnE MILe AgBove Liverpoot TO HAvANA 
Number per square yard 
| 
Pounds per acre 
Campeloma subsolidum 
Asellus sp. 
280.0 840.0 
Lioplax subcarinatus 74.7 89.6 
1294.0. 5156.0 
Vivipara contectoides* 815.6 4078.0 
Pleurocera sp. 123.7 148.4 
Amnicola emarginata 3.0 3.0 0.1 0.1 
Leeches (small spp.) 106.7 18.1 
. 64.5 171.8 6.1 24.7 
Hexagenia bilineata (nymph) 0.6 0.5 
Total 1468.8 5180.8 
* Including a few V. subpurpurea. 
