CONTENTS 



Page 



Introduction . 5 



Biology 8 



Collecting and preserving 9 



Diagni stic characters 10 



V< nation 12 



Genital characters 27 



Classification 30 



Key to families 31 



I I KRONARCIDAE , 32 



Pteronarcys 33 



Ptercnarcella 41 



PERLIDAE 47 



Perlodes 50 



Isogenus 68 



Peiia , 73 



Alloperla 104 



Chloropsrla 127 



Paraperla 129 



Kathroperla 131 



Neoperla 133 



Cliopei-la 137 



Isoperla 144 



Perlesta 156 



Atoperla 160 



Perlinella 162 



Peltoperla 165 



Acroneuria 173 



NEMOURIDAE 196 



Nemoura 197 



Leuctra 222 



Perlomyia 234 



Taeniopteryx 236 



CAPNIDAE 252 



Capnia • 253 



Capnura 270 



Capmdla 271 



Bibliography 27!) 



Systems of Classification _• 285 



List of species 286 



Table of distribution by States 290 



Finding list foi the plate figures 291 



Plates and explanations 



Index 392 



