Hagen.) 284 [January 22, 
terior border and sides nearly straight ; hind border arcuated; the 
narrow, yellow middle line broader at the ends. — 
Male. The ninth ventral segment straight at the tip, not covering 
the tenth, on each side a scar before the tip; middle part horny, 
transversally striated; the tenth dorsal segment with two transverse 
knobs; penis long, the base bifid above, with a rectangular hook be- 
neath, and a membranous lobe before the tip and above it. 
Female. The eighth ventral segment convex, produced at the 
tip into two conical processes, straight inside, oblique outside, reach- 
ing half way over the ninth segment, separated by a rounded notch. 
Length, inclusive of the wings, 35-45 mm. Exp. of the wings 
65-85 mm. I have seen 12 specimens, 10 6 and 2 2, from Ogden, 
Utah, caught in June, and from a river tributary to the Great Salt 
Lake, all preserved in alcohol, also a female from Lake Winnipeg, 
collected by R. Kennicot. 
I have some nymphe from the Ogden River, Utah, probably be- 
longing to this species; taken Sept. 15th. Length 31 mm.; brown, 
tibiee yellowish, with darker knees; antenne inside of the base, with 
asmall plate, ending behind in a strong tooth; prothorax: a little 
broader behind, the four angles each produced into a sharp tooth; 
hind border of the mesothorax and metathorax nearly in a straight 
line with the wing covers. Last dorsal segment produced in a long, 
straight, conical process. (Male.) 
Another nympha from Washington Territory, between Rock and 
Cascade Mountains, is nearly 40 mm. long, and seems to be nearly 
full-crown. ‘The wing covers of the mesothorax are more curved be- 
hind; the last dorsal seement has a similar, but shorter, process, bent 
up a little; the eighth ventral segment shows the beginning of the 
vulvar lobes; the tibiee are darker. (Female.) 
I sent a pair to Mr. M’Lachlan, and he writes that the type in the 
British Museum resembles those from Ogden in its wings, but be- 
long to P. californica. Some specimens from California in his collec- 
tion, also belonging to the same species, have the wings very smoky 
and almost opaque. 
After a new examination of the description of Pt. biloba Newm., 
from Trenton Falls, N. Y., and the diagrams of the type made by me 
in London, after the type, I believed this species to be identical with 
Pt. californica; at least I could not find any specific differences. 
The bifid vulvar lobes agree well with my diagram, but of course 
not exactly alike, as the Ogden specimens are preserved in alcohol, 
-& 
