262 
opportunity, through the courtesy Hier. 
E. S. Ross, to study the holotypic male 
in the collection there. It is now my 
opinion that lobata is specifically identical 
with californica and therefore should be 
relegated to synonymy. Allowance must 
be made for slight variations in compli- 
cated genitalic structures of the character 
represented by this and other stonefly spe- 
cles. 
The allotypic female as well as male 
and female paratypic specimens of cali- 
fornica are in the collection of Cornell 
University, and material in the Illinois 
Natural History Survey collection has 
been compared with these specimens. 
CAPNITDAE 
In my 1935a@ paper on Illinois stone- 
flies, I presented a key for the separation 
of the genera of Capniidae occurring in 
Illinois. This key included the genera 
Allocapnia and Capnia. Under the dis- 
cussion of Nemocapnia carolina Banks in 
the present paper, I show that my ques- 
tionable record of a single Illinois speci- 
men of Capnia (vernalis Newport?), a 
female (1929 and 1935a), belongs to the 
genus Nemocapnia and not to Capnia. 
However, in 1940, specimens of Capnia 
opis (Newman) were taken in northeast- 
ern Illinois, and it is desirable, therefore, 
to present a new key to the Illinois genera 
of Capniidae to replace the one of 1935a. 
KEY TOSLLINOIS=SPEGIES “OF 
CAPNIIDAE 
ADULTS 
1. Eighth abdominal tergite of male with a 
raised process or tubercle-like struc- 
ture; wings sometimes absent or ab- 
breviated; anal field or lobe of hind- 
wing, when wing is present, large and 
extending nearly out to tip of wing.... 
ee Be tents ed See Allocapnia, p. 265 
Eighth abdominal tergite of male with- 
out a raised process or tubercle-like 
Structures. 
2. Wings normally developed; radial vein 
near point of origin with radial sector 
straight; no oblique crossvein beyond 
end of subcosta in forewing; posterior 
margin of large, darkly sclerotized 
medial area (mesobasisternite) of mes- 
osternum but slightly produced back- 
Ward pug o7 Seen Nemocapnia, p. 262 
Wings normally developed, absent or ab- 
breviated; radial vein near point of 
origin with radial sector slightly but 
distinctly bent forward; usually an ob- 
Intinois NaturAL History SURVEY BULLETIN 
V ol. 22, Arta 
lique crossvein beyond end of subcosta 
in forewing; posterior margin of large, 
darkly sclerotized medial area (meso- 
basisternite) of mesosternum strongly 
produced backward, fig. 28........... 
Pe ee Capnia, p. 264 
NYMPHS 
(Nymphs homogeneous with respect to good 
key characters; mature nymphs frequently 
reveal characters used in adult key.) 
Wing pads present in most species, but ab- 
sent or rudimentary in a few species; anal 
field or lobe of hindwing, when pad is 
present, large and extending out nearly to 
length of wing; mesobasisternite of meso- 
sternum, when boundary limits are visible, 
same as for adults, fig. 28. eee 
Re ee Allocapnia, p. 265 
- Wing pads always present; anal field or 
lobe of hindwing reduced and extending 
about to middle of wing length; meso- 
basisternite of mesosternum, when bound- 
ary limits are visible, same as for adults, 
fig: 28.. nie ae Nemocapnia, p. 262 
Wing pads present, absent or rudimentary ; 
anal field or lobe of hindwing, when pad is 
present, reduced and extending about to 
middle of wing length; mesobasisternite 
of mesosternum, when boundary limits are 
visible, same as for adults, fig. 28...... 
vs Ove Orr Capnia, p. 264 
Nemocapnia carolina Banks 
Nemocapnia carolina Banks (1938, p. 74). 
Original description, 6, 9. 
Capnia sp. Frison (1929, p. 407). Errone- 
ous generic assignment. 
Capnia (vernalis Newport?) Frison (1935a, 
p. 356). Erroneous generic assignment. 
In my paper on the Fall and Winter 
Stoneflies, or Plecoptera, of  Illinots 
(1929), I questionably recorded a female 
specimen of a capniid from Grayville, Il. 
March 8, 1928 (collected by T. H. Frison 
& H. H. Ross) as “Capnia sp.” and in 
commenting concerning this specimen sug- 
‘(\—_ i i 
NEMOCAPNIA CAROLINA 
Fig, 28.— 
Capniidae. 
CAPN 
