September, 1942 
matter pertaining especially to Illinois 
with that relating to the North American 
fauna as a whole. As in my paper dealing 
with the stoneflies of Illinois as a unit 
(19352), I have followed a presentation 
order beginning with the Pteronarcidae 
and ending with Chloroperlidae. 
Revised Classification 
In my paper dealing with the stoneflies 
of Illinois (1935a), I gave a discussion 
of the classification then proposed for the 
Plecoptera of North America, together 
with an outline showing the relationships 
of the various groups as I then accepted 
them. As might be expected in the devel- 
Frison: NortH AMERICAN PLECOPTERA 
oor, 
opment of a classification of a neglected 
order of insects, the study of extensive 
material since 1935, particularly from 
western states, has caused some modifica- 
tions of my former views. 
My present ideas regarding the classifi- 
cation of the North American Plecoptera 
down to generic groups are represented by 
the outline below. 
‘This outline represents changes in my 
1935 classification as follows: (1) reduc- 
tion of genera in the family aeniop- 
terygidae to T'aeniopteryx and Brachyp- 
tera, (2) removal of Eucapnopsis from the 
Leuctridae and its placement in the Cap- 
niidae, (3) addition to the Capniidae of 
the recently described genera of Isocapnia 
REVISED CLASSIFICATION 
OF THE PLECOPTERA OF NORTH AMERICA 
Pode OG IN Adah 
or 
mv Li ALP A 
jd wo ay AD aa Md ad wet 
MU BULTIPALPIA 
or 
me tPALPIA 
Maal ELE OGNAT HA; 
['PTERONARCIDAE..... 
PELLOPERLIDAK..—_. 
TAENIOPTERYGIDAE 
DE NLOURT DATA ea 
UA II PIR OW Uh oes Os ee 
CPN DID A Ear er 
BERIT eae ee ee 
PERE OD EDA Les 
JEN OSCIG AUD ae eye, 
Pteronarcys 
\ Pteronarcella 
Peltoperla 
Taeniopteryx 
Brachyptera 
Nemoura 
Leuctra 
Megaleuctra 
-Perlomyia 
‘ Capnia 
Allocapnia 
Capnura 
Eucapnopsis 
Isocapnia 
Nemocapnia 
Atoperla 
Perlinella 
Neoperla 
Perlesta 
Acroneuria 
Neophasganophora 
Togoperla 
Claassenia 
Perlodes 
Oroperla 
Isogenus 
[Diewonten 
Dictyopterygella 
Diploperla 
Isoperla 
Chloroperla 
Hastaperla 
CHLOROPERLIDAE .. |; Alloperla 
Paraperla 
Kathroperla 
