LUCY WRIGHT SMITH 
471 
eighth. Abdomen pale on the venter in the female, dark in the male. Setae 
slender, pale brown in the male, yellowish in the female; the distal segments 
narrowly banded with darker toward the tips. 
Male. Ninth segment entire above, slightly produced below to form a 
narrow subgenital plate which extends to the posterior border of the tenth 
segment. The tenth tergite with a broad median cleft, the opposed edges of 
the lobes emarginate with a broad, yellow, triangular hollowed spot extending 
lateralward from the margin and a short, spine-like projection directed obliquely 
inward and upward on the inner posterior edge of the lobe. Supra-anal plate 
entirely concealed except for the tips of the lateral braces, which show at the 
apical border of the ninth tergite, projecting from the inner anterior borders 
of the cleft of the tenth tergite, as a pair of short, dark brown, triangular proc- 
esses pointing obliquely upward and outward. Sub-anal plates, flat, triangu- 
lar, pressed against and meeting at right angles, the para-genitals which appear 
between the lobes of the cleft and the tenth tergite as a pair of yellowish 
brown, horizontal, triangular lobes (fig. 41). 
Female. The posterior border of the eighth ventral segment prolonged about 
three-quarters of the distance across segment nine, in an evenly rounded sub- 
genital plate (fig. 42). The tenth tergite scarcely elongated; the tips of the 
sub-anal plates touching its ventral surface and concealing the supra-anal 
plate, if it is present 
We have three specimens collected b}' J. C. Bradley; one male 
(alcoholic) from Lake Louise, Canadian Rockies, VI, 25, 1908; 
and two females, one (alcoholic) from Rogers Pass, (altitude 
4500 to 5000 feet) British Columbia, VIII, 7, 1908; and one 
from Ground Hog Basin (altitude over 6000 feet), Selkirk Moun- 
tains, British Columbia, VII, 22 to VIII, 7, 1905. The male is 
the type specimen and the female from Rogers Pass, the allotype. 
These are at Cornell Universitj' in the entomological collection. 
Nymph unknown. 
MEG ARC YS Klapdlek 
1912. Megarcys Klapdlek, Coll. Selys, 4: 10. 
In characterizing this genus Klapalek says it is quite close to 
Arcynopteryx in the structure of the genital appendages, but it 
is sufficiently distinct from it in having a much richer network 
of cross-veins. To enlarge upon Klapdlek’s statement, in the 
male the ninth sternite is produced to form a subgenital plate, 
the tenth tergite is bifid, the inner posterior margin of either lobe 
is prolonged into an appendage-like process directed upward; 
the sub-anal plates are flat, and triangular; the supra-anal plate 
consists of a pair of para-genitals, a median and two lateral 
TRANS. AM. ENT. SOC., XLIII. 
