September, 1942 
NyMPH.—General color of head, tho- 
rax and abdomen brownish with paler 
spots and intersegmental areas as in fig. 
70. Antennae, legs and anal cerci yel- 
lowish brown. 
Head with three ocelli forming a nearly 
equilateral triangle, each lateral ocellus 
about as far apart as each is distant from 
MANDIBLES 
NYMPHAL 
LABIUM 
“<---+- 
NYMPHAL 
MAXILLA 
eee — = LL 
Fig. 71—Hydroperla parallela. 
inner edge of compound eye. A partial 
occipital ridge, interrupted in middle, ac- 
centuates posterior margin of each con- 
spicuous eyelike spot adjacent to and be- 
tween compound eyes and borders hind 
margin of compound eye. Labium, maxil- 
lae and mandibles as in fig. 71. 
Pronotum about two-thirds as long as 
broad, all angles well rounded. Legs 
slender, not greatly flattened. 
Abdominal tergites well covered with 
numerous conspicuous, short, stout setae. 
Cerci_ long, many segmented, segments 
progressively longer from base to apex, a 
longitudinal row of long, fine setae on 
dorsal surface in addition to smaller ones 
encircling segments. 
Approximately mature specimens with 
a body length, exclusive of appendages, of 
about 23 mm. 
A finger-like submental gill at each 
outer posterior corner of submentum, fig. 
71; thoracic and abdominal gills entirely 
lacking, 
Frison: NortH AMERICAN PLECOPTERA 
299 
Nymphal and exuvial records are as fol- 
lows. 
BritisH COLUMBIA.—North of RUSKIN, Stave 
Lake Dam: April 15, 1938, W. E. Ricker, 1 
nymph, 2 exuviae. Cuttus Lake, Chilliwack 
River: April 26-27, 1937, W. E. Ricker, 2 
nymphs. Sarpis, Vedder River: July 23, 1936, 
H. H. Ross, many exuviae. 
IpAHO.—South central part of state: 1938, 
L. H. Smith, 1 nymph. 
OREGON.—CorVALLIS, Marks Creek: Feb. 26, 
1938, B. White, 1 nymph. McKenzie River: 
March 937 1939)5). Es Ds 1 exuvia. 
WASHINGTON.—GREEN and CEDAR RIVERS: 
April 1, 1939, L. Lambuth, 2 nymphs. 
New adult records are as follows. 
BriTIsH CoOLUMBIA.—CULTUs LAKE, Chilli- 
wack River: May 9, 1937, W. E. Ricker, 42. 
OREGON. — MULTNOMAH Fatis, Multnomah 
County: April 8, 1939, S. G. Jewett, Jr., 19'¢;, 
3@. PorTLAND, Multnomah County: March 
17, 1939, S: Ge Jewett, Jr, 16. Clatsop Coun- 
ty, Herman Creek, tributary of Mecanicum 
River, 6 miles south of SEASIDE: Feb. 18, 
1939, S. G. Jewett, Jr.. 26. CLackamas Coun- 
TY: Molalla River, Feb. 23, 1939, Rock Creek, 
tributary of Clackamas River, Feb. 20, 1939, 
and Wildcat Creek, tributary of Sandy River, 
March 31, 1939, S. G. Jewett, 16, 29. CoLum- 
BIA COUNTY: south of north fork of Scappoose 
Creek, Feb. 17, 1939, and Gnat Creek, Feb. 
EF L939 OG. lewett, Jr +36) bon 2ST 
HELENS, Milton Creek, Columbia County: Feb. 
19591939, S23 G, Jewett; Jr. td; “HERMAN, 
Oregon National Forest, 700 feet altitude: 
Owe Sieh O Ag. Ge Burrill la eel-Os 
UraH.—Locan Canyon: April 23, 1938, R. 
E. Nye, 19. 
Dictyopterygella knowltoni Frison 
Dictyopterygella knowltoni Frison (1937, p. 
89). Original description, ¢@. 
The original description of knowltoni 
was based upon a single holotypic male 
from Logan, Utah. Since then I have 
examined additional males and recognized 
the females. A brief description of the 
heretofore undescribed female follows. 
FEMALE.—Similar in most morphologi- 
cal characters to the male (Frison 1937). 
Chief distinguishing characters are as fol- 
lows: Subgenital plate, fig. 72, somewhat 
protruding over ninth sternite and inset 
on eighth sternite; baso-ventral, subanal 
plates heavily sclerotized, projecting back- 
wards along median cleft where right and 
left plates meet to form a short, blunt lobe 
suggesting more modified subanal lobe pro- 
jection in male; length 33 mm. to tip of 
wings and 20 mm. to tip of abdomen. 
Allotype, female—Logan Canyon, Utah: 
April 23, 1938, R. E. Nye. Taken at same time 
and place as male of this species. 
