184 
[October 
in company, in one of which the discal bifurcation of the front wing 
is peduncled, in the other it is not. The same variation has been de¬ 
scribed as occurring in semistriaf.us Walsh. Both specimens, in addi¬ 
tion to the described fuscous spot at the point where the anal vein 
strikes the interior margin of the wing, have a very small faint fuscous 
cloud on and in front of the anal vein f of the distance from its base, 
and also another between the forks of the discal bifurcation, traces of 
which last may be seen in my original specimen. The pterostigma is 
almost black, instead of pale fuscous, or cinereous. These clouds might 
seem to approximate -perplexus to Novse-Scotise^ but in JVovse-Scotise 
the veins on the posterior side of the discoidal cellule and at the origin 
of the branch of the 1st sector are milk-white; in perplexus they are 
fuscous. 
Ps. POLLUTES Walsh. A specimen taken at Rock Island has the 
coloration of the vertex and thorax more obscure. The dimensions 
are the same. 
Note 3, p. 168. Ps. geologus Walsh. In the autumn of 1862 I 
beat a specimen of Ps. amah ills Walsh, olf an oak tree remote from 
any house, the first specimen having been found dead amongst my in¬ 
sects. If Ps. geologus be identical with Ps. salieis.^ and if, as the name 
indicates, this latter species was found on willows, it is most probable 
that both amahilis and salicis are indigenous insects, and that the lat¬ 
ter is not identical with the European Ps. pedicular ms Linn. I com¬ 
monly, however, find the European Dermestes lardarius near Rock 
Island, under bark, remote from houses, along with its larva, feeding 
apparently on the dead insects and spiders which accumulate there. I 
believe that both amahilis and geologus are, in the imago state, nor¬ 
mally apterous but occasionally winged, and that it is these species 
which infest collections of insects in which camphor is not kept. In 
a close box good camphor kills them in half a day. They are so pecu¬ 
liarly fond of Ephemerina that I find it necessary to dry all my Ephe- 
merina in a close box with camphor in it. 
Note 4, p. 168. Ps. abruptus and Ps. corruptus Hagen. So far 
as I can judge by their eyes and antennae, all my 9 specimens of ahrup- 
tus are 9 ? and all my 9 specimens of corrup)tus % . The facts indicate 
that Dr. Hagen was right in supposing the two species to be identical. 
The hyaline apical spot is very plain in all my specimens of corruptus, 
but varies much in size. 
