September, 1942 FRISON : 
TeExAs.—Et Paso: April 22, 1939, J. A. & 
atti. “Ross, 84 (brachypterous), 9“ 9, 3 
exuviae. 
WYOMING. — Madison Junction, YELLOW- 
STONE NATIONAL PARK, Gibbons River: July 
8, 1936, H. H. Ross, 19. Prinepae, Green 
River north of town: July 6, 1936, H. H. Ross, 
i3.- Upron: June 20, 1940, J. A. & H. H. 
Ross, 2¢, 19. 
Isoperla mormona Banks 
Isoperla mormona Banks 
Original description, @. 
Isoperla insipida Hoppe 
Original description, ¢, 9. 
(1920, p. 322). 
(19380 pis 7 
New synonymy. 
‘This species is apparently closely re- 
lated to longiseta Banks, as mentioned in 
the discussion of that species. The type, 
a single female, No. 10,822, from ‘‘Vine- 
yard, Ut.,” in the collection of the Mu- 
seum of Comparative Zoology, has been 
studied and compared with specimens in 
the Illinois Natural History Survey col- 
lection. Also, through the kindness of 
Professor Trevor Kincaid of the Univer- 
sity of Washington, I have had the oppor- 
tunity of studying the holotype and allo- 
type of instpida, as well as most of the 
paratypic specimens. I find them all to 
be synonymous with mormona, which is 
apparently a Rocky Mountain and West 
Coast species, meeting with longiseta in 
such states as Wyoming and Montana. 
Records for this little-known species con- 
tained in the collection of the Illinois Natural 
History Survey or identified for others are 
as follows. 
ARIZONA.—COCcONINO County, Oak Creek at 
Indian Garden: June 13, 1937, Leonora K. 
Gloyd, 46, 3@. 
MoNnTANA.—TosTon, Missouri River: June 
memetos0,, HoH. & J. A. Ross, 36, 79. 
OREGON.—BENTON County, Oak Creek: R. 
E. Rieder, 1¢, 12. Corvatiis: April 18, 19350) 
8. E. Crumb, Jr., 16; April 21, 1938, W. M. 
W., 13. FRENCHGLEN, Harney County, Blitzen 
River: July 7, 1935, S. G. Jewett, Lae Ma ba 
62; July 11, 1935, 96, 62; Aug. 2, 1935. 
Granger Station, near CorvALuis: April, 
#738, N. A. Ramsdell, 6¢, 29. KLAMATH 
County, Crooked Creek: July 8, 1940, F. 
Glover, 83, 99. MALHEUR County, Trout 
Creek: July 30, 1937, S. G. Jewett, (yen ese 
32. Morarra, Clackamas County, Molalla 
River: July 1, 1935, S. G. Jewett, Jr, 19. 
PENDLETON: June 5, 1934, R. E. Dimick, 19. 
SUTTLE LAKE, 3,435 feet elevation: Aug, 2 6 
1935, H. A. Scullen, 19. 
UraH.—American Fork: July 6, 1939, G. 
F. Knowlton, 18, 292. ELSINORE: July. 22, 
1937, G. F. Knowlton, 446, 22. HEBER: July 
25, 1940, G. F. Knowlton, 19. Lent: July 
2, 1939, G. F. Knowlton, 42. LoGAN CANyon: 
May 17, 1933, G. F. Knowlton, 19. Mu.rorp: 
NorrH AMERICAN PLECOPTERA 321 
July 2, 1941, Knowlton & Hardy, 12. Orron: 
July 5, D. J. & J. N. Knull, 19. Sunset: July 
26, 1933, G. F. Knowlton, 39. 
Wyominc. — Boutprer, tributary of Pine 
Branch River: July 6, 1936, H. H. Ross, 29. 
MapIsoN JUNCTION, Yellowstone National 
Park, Gibbons River: July 8, 1936, H. H. 
Ross. 14 2 OF 
Since insipida is a synonym of mormona, 
the Washington and Oregon records associated 
with imsipida must now be referred to mor- 
mona. 
Isoperla dicala new species 
Mave.—General color creamy yellow 
with fuscous or brownish areas. General 
type of coloration similar to that of the 
TIsoperla bilineata (Say) complex. Dorsum 
of head dominantly creamy yellow with- 
out a dark V-shaped area uniting lateral 
and median ocelli, a few small dusky or 
brownish spots adjacent to ocelli, fig. 98. 
Pronotum with margins and a wide, medi- 
an, longitudinal stripe creamy yellow; area 
each side of stripe with raised rugosities 
dusky or brownish, fig. 98. Mesonotum 
and metanotum mostly creamy yellow but 
each with a dusky or brownish spot on 
central posterior area, fig. 98. Abdomen 
entirely creamy yellow. Legs, except for 
brownish tarsi, essentially creamy yellow. 
Antennae with basal segments creamy yel- 
low and succeeding segments fuscous or 
brown. Anal cerci creamy yellow. 
Head slightly wider through compound 
eyes than width of pronotum; lateral ocelli 
farther distant from one another than 
each is distant from median ocellus, dis- 
tance between each lateral ocellus and 
inner margin of compound eye about one- 
half the distance between lateral ocelli. 
Pronotum approximately quadrangular, 
broader than long, a distinct pattern of 
raised rugosities on surface each side of 
yellow, median, longitudinal stripe, fig. 98. 
Legs with first and second tarsal seg- 
ments together much shorter than third, 
first tarsal segment longer than second. 
Wings mostly very pale or hyaline, with 
stigmal areas milky; veins mostly pale, 
but costal and some in middle area of wing 
brown. 
Abdomen, fig. 98, with tenth tergite not 
cleft; subanal lobes weakly developed and 
scarcely visible from above; ninth sternite, 
fig. 98, produced backwards so that apical 
tergites are not visible in ventral view, 
eighth sternite with a prominent long, 
