260 
Since occidentalis was described, three 
additional specific names of closely related 
forms have been proposed. Fig. 22 shows 
the modified anal cercus of a male speci- 
men from “Prairie Hills, B. C., July 19, 
1908,” in the collection of the American 
Entomological Society of Philadelphia, 
which agrees very well with purcellana 
Neave (1934) described from British 
Columbia. Fig. 23 shows the modified 
anal cercus as it exists in specimens from 
Oregon that I described (1937) under the 
name of forcipata. 
Claassen (19375) proposed the name 
of sara for a species of this genus from 
New York which very closely resembles 
the western occidentalis and the related 
forcipata and purcellana. Fig. 24d shows 
the character of the variation observed in 
the modified anal cercus from a Massa- 
chusetts specimen; fig. 2+B from an Indi- 
ana specimen; 24C-—F from ‘Tennessee 
specimens. I am strongly of the opinion 
that all of these eastern specimens are of 
the same species, and the differences are 
due merely to variations in local popula- 
tions. 
The differences between sara and occi- 
dentalis are certainly slight, and there 1s 
reason to suspect that collecting in north- 
ern states and southern Canada will show 
that sara is specifically the same as oce?- 
dentalis. ‘The same fate in synonymy may 
be in store for the more divergent forms 
described as forcipata and purcellana. Un- 
til further evidence to this effect is pro- 
duced, however, it seems the safest pro- 
cedure to hold occidentalis, forcipata, 
purcellana and sara as distinct species, 
recognizing that certain specimens are 
merely variants (no names necessary) of 
these more widely separated units. The 
recognition, for the time being at least, of 
these four major types as species causes 
me to propose another specific name for 
an even more divergent form. Certainly, 
this new form deserves specific status if 
sara (eastern states) is held as distinct 
from occidentalis (western states), be- 
cause it is quite different from the other 
related forms. 
Leuctra projecta new species 
Ma.e.—Similar in most morphological 
features to occidentalis Banks (1907). 
Differs in the shape of the modified anal 
cercus as illustrated in fig. 25. 
Ittinois NATURAL History SURVEY BULLETIN 
Vol. 22, Art. 2 
FremMA.e.—Unknown but probably very 
similar to the female of occidentalis. 
Holotype, male.—Rocky Mountain National 
Park, Wild Basin, Colo.: June 13, 1937. 
Paratype. — OREGON. — COLUMBIA COUNTY, 
Scappoose Creek: Feb. 19, 1939, S. G. Jewett, 
Jrasice 
The modified anal cerci of the paratype, 
fig. 25B, differ from those of the holotype, 
fig. 254, as shown by comparing the two 
Fig. 25.— 
Leuctra 
projecta. 
A ee 
3 Cerci 
drawings. I am considering the two speci- 
mens, however, to be of the same species 
because of the features in common which 
are very different from those of the other 
described species. Leuctra projecta will 
fall in the group of species for which Han- 
son (1941) proposed the generic name of 
Paraleuctra and which, at least for the 
present, I am considering as of subgeneric 
status. 
NEMOURIDAE 
Nemoura Latreille 
As in the case of the genus Lewctra, 
only one species of Nemoura was known to 
occur in Illinois when my paper (1935a) 
on the Illinois stonefly fauna was pub- 
lished. Recently, a second species of this 
genus has been found in northeastern IIli- 
nois, thereby necessitating the following 
keys for the separation of the Illinois spe- 
cies of Nemoura. 
KEY TO ILLINOIS SPECIES OF 
NEMOURA 
MALES 
Gill remnants in cervical region; forward 
recurved part of supra-anal process nar- 
row and elongate; anal cerci small, mem- 
branous and without special structures, 
fig. 26. saw vee) «0s venosa 
Without gill remnants in cervical region; 
supra-anal process broad, somewhat knob- 
like, fig. 27; anal cerci elongate, strongly 
sclerotized and with projecting points 
at tip. (22k iano. sae trispinosa, p. 261 
