493 
12 CoLLections, 4- To 7-rT. Zone, AucG. 12, 22, 23, 1915 
HEAD oF DramMonp ISLAND TO GRAFTON 
Number per square yard} Pounds per acre 
Musculium transversum 4.4 2.2 
bil 4.8 
Young Unionidae 1.3 2.6 
| 
Chironomid larvae (small spp.) | 1.4 0.2 
Corethra larvae 0.5 trace 
Hexagenia, etc. (nymphs) 5.5 4.9 
11.3 5.5 
Hydropsyche larvae 0.9 0.2 
Gomphid nymphs 0.1 0.1 
Oligochaetes (small spp.) 2.9 0.1 
Total 17.0 10.3 
12 CoLLectTions, 1- To 3-FT. ZonE, Ava. 12, 22, 23, 1915 
Heap or DiamMonp ISLAND TO GRAFTON 
Number per square yard| Pounds per acre 
Campeloma subsolidum 0.1 01 0.3 0.3 
Musculium transversum 6.3 3.1 
7.9 6.3 
Young Unionidae 1.6 3.2 
Chironomid larvae (small spp.) 1.6 0.2 
Corethra larvae 0.7 trace 
Hexagenia, etc. (nymphs) 23.2 20.8 
Caddis larvae (“stick”) 0.1 29.3 trace 21.3 
Gomphid nymphs 0.1 0.2 
Oligochaetes (small spp.) 3.2 0.1 
Leeches (small spp.) 0.4 trace 
Total 37.3 27.9 
