176 ENTOMOLOGICAL SOCIETY 
not succeed in finding a piece of bark which would show the nature of the 
galleries. The beetles had long since deserted the trees, and all I could 
find were several dead specimens which served for identification. I am in- 
clined to doubt that this Scolytid is the first cause of the decay of the 
tamarac, since I partake of the opinion of those who believe that in a 
country without forest cultivation Scolytids attack only diseased or other- 
wise injured trees, and healthy trees only when they are cultivated in our 
gardens and parks. The gradual drying up of the tamarac swamps, in 
consequence of the improved drainage of the country, is, I think, the first 
and main cause of the decay of tamarac trees in Michigan and elsewhere. 
Mr. Harrington continues : "Associated with them [the Dendroctonus] 
were large numbers of a smaller bark-borer, Hylesinus oflaculus, with one 
or two other species, which would not be likely from their habits or num- 
bers to do much injury." What the "one or two other species" may be I 
am unable to say, but it is certain that Mr. Harrington's Hylesinus opaculus 
is simply a wrong determination. This species lives on certain deciduous 
trees, viz., elm and ash, but never attacks Conifers. Mr. Harrington's 
species is either Polygraphus rufipennis or Phlxosinus serratus, or possi- 
bly also a species yet unknown to me. The food-habits of most Scolytidce 
are so particular that a mere knowledge of them enables us to control the 
correct determination of the species. 
MALE CHARACTERS IN PISSODES AFFINIS. The male of this species 
can be distinguished by the following characters : Hind tibia? curved at 
apical half, their inner edge flattened, smooth and shining, and furnished 
at the apical third with a brush of long black hair. This character can be 
observed even without the aid of a lens, and at once distinguishes P. affinis 
from the other eastern species in which the tibiae are alike in both sexes. 
The few specimens of our western Pissodes which I was able to examine 
show also no distinguishing sexual characters. 
THE FEMALE OF PHOTINUS COLLUSTRANS. Only one species (P/i. 
scintillans] of this genus was hitherto known to differ strikingly from the 
male by being wingless and having short elytra, but from a specimen found 
by Mr. H. G. Hubbard at Crescent City, Fla., it appears that the female 
of Ph. collustrans possesses the same characters. The head and thorax in 
the female of this species are much smaller than in the male; the eyes are 
also much smaller, and the antennae shorter and stouter; thorax and elytra 
are colored and sculptured as in the male, but the elytra, which are a little 
narrowed posteriorly, do not quite reach to the posterior margin of the 
second dorsal abdominal segment; wings entirely absent; abdomen twice 
as long as the combined length of thorax and elytra, but not inflated in the 
single specimen before me, and of a nearly uniform yellow color, so that 
nothing can be said regarding the extent of the light-organs. The abdo- 
men has, however, the appearance of being luminous throughout. The 
last segment has a smooth longitudinal impression at the middle of the 
base, and the stigma-like impressions at the sides of the segments are ab- 
sent. I feel quite confident now that the female of Ph. punctulatus. 
