i86 A NATURALIST IN THE GREAT LAKES REGION 



a 



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Fig. 2 1 2A. — Some aquatic insects and nymphs. After P. S. Welch, a, stone-fly 

 nymph; i, May-fly nymph; c, whirhgig beetle larva; </, black-fly larv'a; e, damsel- 

 fly nymph; /, water tiger; g, larva of water scavenger; h, the dobson; ?, diving 

 beetle; j, giant waterbug; ^, smaller waterbug; I, water-scavenger beetle. 



