254 
NympuH.—In general similar to the 
nymph of fasciata (Burmeister), as de- 
scribed by Frison (1929, p. 385). Differs 
RIGHT HIND WING 
NYMPHAL ABDOMINAL 
STERNITES 
Fig. 14.—Brachyptera contorta. 
chiefly in that ninth abdominal sternite 
has a broad, platelike projection extending 
about to tip of abdomen, fig. 14, instead 
of a narrow, platelike projection. 
Nymphal specimens from same locality as 
allotype. 
Illinois Natural History Survey collection 
records are as follows. 
CoNNECTICUT.—EAsT HAMPTON: 
as for allotype, 2¢, 12, 16 nymphs. 
VIRGINIA.—STANDARDSVILLE: March 21, 1940, 
T. H. Frison, C. O. Mohr & A. S. Hawkins, 
1¢, 79. SPERRYVILLE: March 17, 1940, T° H. 
Frison, ef al., 7¢, 39, 3 nymphs. 
Same data 
Brachyptera rossi new species 
Mave.—General habitus similar to that 
of other species of Brachyptera. Head, 
thorax and abdomen mostly black with 
portions suffused with reddish brown. An- 
tennae black, the segments longer than 
broad throughout length. Legs with tarsi, 
tibiae and apical third of each of the 
femora black; basal two-thirds of each of 
the femora yellowish brown. No traces of 
membranous gill scars on coxae. Wings 
with veins black and membrane smoky, 
venation as in fig. 15. 
Apical abdominal segments intricately 
modified and presenting the distinctive 
characters, fig. 15, for this new species as 
follows: Ninth abdominal sternite greatly 
Iutinors Natura History SURVEY BULLETIN 
Vol. 22, Arta 
prolonged into a plate which extends back 
beyond the tip of abdomen, then bends 
upwards and is club headed at tip as 
viewed from the side, with a stout, sickle- 
shaped structure at tip as viewed from 
above, and near its base there is a prom- 
inent lobe; tenth abdominal tergite bears 
two slender, pointed projections, directed 
backwards, on middle of posterior mar- 
gin; cercus 5 or 6 segmented, with a plate- 
like lobe at its base above; supra-anal 
process a short, stout, pointed lobe; sub- 
anal lobes complicated, asymmetrical and, 
viewed from above, as in fig. 15. Length 
to tip of wings, 13 mm. 
Holotype, male.— Near Woodstock, Bog 
Brook, N. H.: June 21, 1941, T. H. Frison 
& =H. Ho Ross: 
I take great pleasure in naming this spe- 
cies for Dr. H. H. Ross, of the Illinois 
Natural History Survey staff, who has 
greatly assisted in many ways my studies 
of the North American Plecoptera. 
Five Brachyptera exuviae were found 
under a bridge near the place where the 
RIGHT WING 
on 
ABDOMINAL 
STERNITES 
\\ 
ii, 
e 
—S = ss 
SSS 284w 
SE 
‘ . 
o' ABDOMINAL SEGMENTS 
Fig. 15.—Brachyptera rossi. 
