Fig. 12. Invertebrate life on clay bottom, a 16 square inch unit, water 

 4 feet deep. The principal animals are fresh-water sowbugs (Ascllus, 1) ; 

 Caddis-fly larvae (Ar/rai/lca,2, Phryganeidac, 3) ; snails (Amnicola, 4) and 

 Scuds (Hyalella, 5). Southwest corner of Lower South Bav. 



