320 Itttno1is NaturaAt Hisrory SURVEY BULLETIN 
Fig. 96.—Isoperla longiseta, adult male from 
Texas. 
more like mormona. The other characters 
of these Texas specimens, and, particular- 
ly, the shape of the subgenital plate of the 
female, strongly support, however, their 
specific identity with longiseta. The Ili- 
nois Natural History Survey collection 
also contains a single male from “La Veta 
Pass, Colorado,” which apparently agrees 
with the Texas specimens in every way. 
The nymph of this Texas race, as I now 
consider it, of longiseta is typical of the 
Isoperla group or complex containing the 
species bilineata (Say). Fig. 94 shows the 
shape of the mandibles, maxillae and 
labium, and fig. 97 is a dorsal view of the 
nymph, all drawn from exuviae. The 
nymph of typical longiseta from other 
states has not been described or illustrated, 
and when found it should help clear up 
the status of these Texas specimens. 
Distributional records for longiseta based 
upon specimens in the Illinois Natural History 
Survey collection, or submitted for identifica- 
tion, are as follows. 
Vol. 22, Ar 
ILLINOIS.—QUINCY: June 8, 1939, Burks & 
Riegel, 19. 
CoLorapoO.—LA VETA Pass: July 21) 09am 
Do Jae J SNe Kuli (brachypterous). 
Iowa.—AMEs: May 30, 1929, 16, 19 ; June 
1, 1929, 29; June 3, 1929, 36, 12; June 10, 
19310 Po vA} Moorea 
MINNESOTA.—ST. PAUL, University Farm at 
light: June ‘16, 1933) Ages Granovsky, 19. 
MIssoUR!I.— JEFFERSON City: May 29, 1937, 
H. Ho Rosso elo 
MontTANA. — GLENDIVE, Yellowstone River: 
July 14, 1940, J. A. & H. H. Ross, 36, 79% 
Me Pa 
Fig. 97.—Isoperla longiseta nymph, drawn 
from exuviae collected in Texas. 
LouMan, Milk River: July 13, 1940, J. A. 
& H. H. Ross, 22. WoLrF POINT, Missouri 
River: July 14, 1940, J. A. & H. H. Ross, 
ZO 9 22 
SourH Daxkora.—Brookincs: 12; June 6, 
1919, H. C. Severin, 1¢. BUFFALO: June 19, 
1925, H. C. Severin, 1¢, 19. CHAMBERLAIN, 
Missouri River: June 19, 1940, J. A. & H. H. 
Ross, 68, 39. Grass Rope: June 24, 1931, 
H. C. Severin, 1¢, 19. NEWELL: June 19, 
1923, H. C. Severin, 16. SPRINGFIELD: June 
15, 1928, H. C. Severin, 19. YANKTON: June 
18, 1930, G. I. Gilbertson, 2¢, 49; June 
25, 1934, H. C. Severin, 29. 
