September, 1942 
‘; 
Fig. 79—Nymph of Diploperla pilata. 
Approximately mature specimens with 
a body length, exclusive of appendages, of 
17 mm. 
Nymphal and exuvial records are as fol- 
lows: Sumas River, British Columbia, May 
4-6, 1937, W. E. Ricker, 3 nymphs, 1 exuvia. 
I am naming this species as new with 
considerable misgiving because of its close 
relationship with Diploperla  expansa 
(Banks), described from Colorado; fu- 
ture collecting and studies may determine 
that they are synonymous. D. expansa is 
represented in the Illinois Natural His- 
tory Survey collection by two females from 
Separate localities in Colorado. These 
differ from the specimens here described as 
new in having a much larger and more 
quadrate subgenital plate; also, there are 
some differences in the color pattern on the 
head. Furthermore, Claassen (1931) de- 
scribed, but did not figure, the nymph of 
expansa as having the lacinia unidentate 
and similar to D. bilobata (Needham & 
Claassen). The nymphs described here, 
Frison: NortH AMERICAN PLECOPTERA 307 
and which I am certain go with the adults 
here described, have the lacinia bidentate. 
If Claassen’s association of the nymph 
with expansa is correct, then this proposed 
new species is certainly distinct. There is 
a possibility, however, since Claassen did 
not actually rear any specimens of expansa 
from the nymphs he describes, that nymphs 
he called expansa are D. modesta (Banks) 
or some other closely related species. 
Diploperla bulbosa new species 
Mae. — General color _ yellowish 
brown. Head and pronotum with dark 
and light areas forming an indistinct pat- 
tern, as in fig. 80. Legs and antennae in 
general concolorous with head and thorax; 
anal cerci with apical segments more yel- 
lowish. No gill remnants. 
Head through compound eyes about as 
wide as pronotum; lateral ocelli slightly 
more removed from one another than from 
anterior ocellus, distance between each lat- 
eral ocellus and inner margin of compound 
eye about equal to distance between lateral 
ocelli. 
Pronotum approximately quadrangular, 
somewhat broader than long, a pattern of 
raised rugosities on surface each side of 
rather indistinct, median, longitudinal, yel- 
lowish stripe, fig. 80. 
Legs with first and second tarsal seg- 
ments together about one-half as long as 
third, first tarsal segment slightly longer 
than second. 
Wings with membrane and veins heav- 
ily stained with brown; venation of holo- 
type as in fig. 80, but no doubt subject to 
some variation in a series of specimens. 
Abdomen with segments normal 
through ninth; tenth tergite cleft, fig. 80, 
the lobes formed by this cleft raised up- 
wards; supra-anal process erect and pro- 
truding with tip bulbous, inclosed at base 
by two weakly sclerotized lobes or mem- 
branous folds; without lateral stylets 
flanking supra-anal process; subanal lobes 
elongated, somewhat bulbous at tip and 
forming a back support for supra-anal 
process. Seventh sternite with a broad lobe 
on posterior margin; eighth sternite with 
shght indications of a lobe, accentuated by 
the more numerous concentration of hairs, 
fig. 80. 
Length to tip of wings 14 mm.; length 
to tip of abdomen 18 mm. 
