DISTRIBUTION AND EMERGENCE TABLE 
HE genera are arranged in the same sequence as they occur 
in the Monograph of North American Plecoptera (27). 
The species of which the nymphs are known, and which are 
treated in this paper are marked with an *. 
The black lines cover the time at which the various species have 
been collected in the adult stage. Where no emergence is indi- 
eated, the species have been described originally from specimens 
without date of collection. Under distribution column the follow- 
ing abbreviations are used: E.S. = Eastern states; M.S. = Mid- 
dle states; S.S. = Southern states; W.S. = Western states; N.W. 
= Northwestern states; N.S. = Nova Scotia; Can. Rock. = Cana- 
dian Rockies. The other abbreviations denote States or Provinces. 
