22 
Psyche 
[Mar. 
rounded distally, the outer pair convex, wide and distally 
nearly truncate. Basal segment of clasper long, almost 
two and one-half times as long as wide, margins nearly 
parallel; apical segment about one-half as long, the ven- 
tral margin attenuated as in fig. 6. ^Edeagus long, reach- 
ing to caudal margin of basal segment of clasper, apical 
half of exposed portion slender, tubular, apex bifid; lat- 
eral arms from ventral aspect, fig. 6B, reaching caudad 
one-third length of apical segment of clasper, apices 
gradually convergent, near middle of lateral arms area is 
expanded, its ventral surface bearing a number of minute 
spicules and its margin bearing a series of seven flat setae. 
Female. — Length 12 mm. Same general color and char- 
acteristics as for male. Sixth sternum with an acute 
mesal projection. Eighth sternum with a wide mesal pro- 
jection. Genitalia simple, tubular and tapering from 
base to apex. 
Holotype. Male. — Albany County, Wyoming, Snowy 
Range Mountains, outlet of Mill Pond; September 25, 
1947 (D. G. Denning). 
Allotype. Female. — Same data as for holotype. 
Paratypes. Same data as for holotype, except August 
31, 1947, 2 males. 
All specimens collected from a clear, cold, swift-flowing 
mountain stream at approximately 10,500 feet elevation. 
Rhyacophila verrula Milne 
The collecting of this species in southeastern Wyoming 
constitutes a considerable extension to its previously 
known range of British Columbia, Alberta, Oregon and 
Washington. Male genitalia, fig. 7, drawn from a speci- 
men compared to holotype. 
Wyoming: Snowy Range Mountains, outlet of Lake 
Marie; August 31, 1947 (D. G. Denning), 3 males, 1 fe- 
male. Collected along a rapid mountain stream at 10,500 
feet elevation. Albany County, Snowy Range Mountains, 
outlet of Mill Pond; September 25, 1947 (D. G. Denning), 
1 male. Collected along a rapid mountain stream at 
10,500 feet elevation. Albany County, Snowy Range 
Mountains, Nash Fork Creek; September 25, 1947 (D. G. 
