FRISON: 
September, 1942 
Ny MPHAL 
MANDIBLES 
iia yaa’ 
NyYMPHAL LABIUM 
NYMPHAL MAXILLA 
Fig. 54.—Claassenia arctica. 
listed above, I present the following additional 
data from the Illinois Natural History Survey 
collection. 
MonTANA.—VarNEY, Madison River: July 
29, 1937, P. Jennings, 1 nymph. GtLacier NA- 
TIONAL Park, Logging Creek: July 11, 1940, 
H. H. & J. A. Ross, 2 nymphs, 1 exuvia. 
SouTH Dakora.—SPEarFIsH: July 25, 1924, 
me; July 27, 1940, T. H. Frison & T. H. 
Frison, Jr., 3 exuviae. 
WASHINGTON.—SEATILE: C. V. Piper (col- 
lection of N. Banks), 14 ; Cedar River, April 
1, 1939, L. Lambuth, 2 nymphs. 
WYOMING. — YELLOWSTONE NATIONAL PaRK, 
Gardiner River, Yellowstone River, Cascade 
Creek and Nez Perce Creek: July 30-Aug. 3, 
1940, T. H. Frison & T. H. Frison, Jr., many 
nymphs, 6 ¢, 99. Granp TETON NATIONAL 
Park, Taggart Creek: Aug. 7, 194000. oH: 
Frison & T. H. Frison, Jr., 3 nymphs, 1 exuvia. 
DANIEL, Green River: Aug. 1309) 940 be a 
Frison & T. H. Frison, Jr., 1 exuvia. Mooss, 
Snake River: Aug. 6, 1940, T. H. Frison & 
T. H. Frison, Jr., 6 nymphs, 6 exuviae. 
CoLorapo.—IpA: June 19, 1934, 12. Gun- 
NISON: July 3, 1934, 36. EsTEs Park, Big 
Thompson River: Aug. 4, 1940, T. H. Frison 
Gat. H. Frison, Jr., 2 nymphs, 5 exuviae. 
IpAHO.—Swan Valley, Caripou NATIONAL 
Forest: Aug. 28, 1935, H. S. Telford, 19. 
Although Claassen (1931) described 
and figured this nymph, but under the 
wrong name, it seems desirable here to 
present a new illustration of it, fig. 53, and 
ot illustrations of the mouthparts, fig. 
PERLODIDAE 
Perlodes Banks 
It has been my good fortune to study in 
considerable detail the types, or what re- 
NortH AMERICAN PLECOPTERA 
287 
mains of them, of drcynopteryx vagans 
Smith, Arcynopteryx aurea Smith, Arcy- 
nopteryx lineata Smith, Protarcys bradleyi 
Smith, Protarcys dolobrata Smith (the ne- 
allotype only), Dictyopteryx irregularis 
Banks, Dictyopteryx signata Hagen, Per- 
lodes slossonae Banks, Perlodes yosemite 
Needham & Claassen (allotype) and Per- 
lodes tibialis Banks. All of these species 
were placed by Needham & Claassen 
(1925) in the genus Perlodes, and while 
these authors sank Protarcys Klapalek, 
Megarcys Klapalek and Arcynopteryx 
Klapalek as synonyms of the subgenus 
Perlodes, they proposed the new subgenus 
Perlinodes for the reception of Arcynop- 
teryx vagans. 
I have studied too few specimens of 
adults and nymphs to permit me to come 
to definite conclusions regarding the prop- 
er appraisal of the names Arcynopteryx, 
Megarcys, Protarcys, Perlinodes and Per- 
lodes. For the present, at least, it seems 
that the safest procedure is to follow 
Needham & Claassen (1925) in placing 
them all in the genus Perlodes and recog- 
nize as subgenera the other proposed units 
of classification above the rank of species 
in this family. 
The studies have progressed far enough, 
however, to indicate that much synonymy 
exists in the genus and that fine distinc- 
tions of wing venation are not reliable 
for species determinations. One of the 
outstanding features of Perlodes (s.1.), as 
I recognize the genus, is the variety and 
character of gills. All species studied to 
date have the submental gills found in 
Isogenus and Hydroperla, and some spe- 
cies have additional pairs of gills in the 
cervical region and on the thorax. Need- 
ham (1933) has even described a new 
genus, Oroperla, with a new species called 
barbara, based upon the nymph, which has 
a row of gills on each side of the abdom- 
inal segments. The adult of barbara, 
when found, should show remnants of 
these gills. 
My conclusions to date regarding valid 
species and synonymy are presented under 
the headings of the species concerned. 
Perlodes minor (Klapdlek) 
Arcynopteryx minor Klapalek (1912, p. PEN 
Original description, ¢@. 
Perlodes slossonae Banks (1914, p. 608). 
Original description, 9. New synonymy. 
