74 Mr. Walter F. H. Blandford on the 
Scutellum round, dull, punctured. Elytra scarcely wider than 
prothorax and rather less than twice as long, their basal borders 
rounded, crenate, slightly everted, sides straight at base, rounded 
from middle to apex ; above gradually declivous almost from base, 
black, with apex sometimes piceous, with short scanty pubescence, 
without scales or setose hairs, strix rather fine, indistinctly punctured 
at base, nearly smooth towards apex, interstices granulate to 
middle, then 2nd and 4th in male smooth, multi-punctate, with one 
or two tubercles before apex, in the female with a few fine 
tubercles throughout ; Ist in male with about 5, 3rd with about 7 
strong spinous tubercles, which do not unite to form a crest, in 
female with smaller tubercles : outer interstices towards apex with 
rows of tubercles in both sexes. Underside black, punctured, 
pubescent ; metasternum rather prominent. Legs black with tarsi 
lighter. 
The-largest Japanese species and the only one allied to 
the Huropean species in appearance and sexual characters. 
Potye@rapuus, Er. 
Of all the genera of the family, this one, considering 
its small extent, is the most difficult to deal with. Till 
recently it included but two species, P. poligraphus, Lin., 
and rufipennis, Kirby, but Thomson has added three 
others found in Hurope, of which I have seen but one, 
P. grandiclava, or rather an insect forwarded to me by 
Herr Reitter as P. poligraphus, var. grandiclava. I have 
also had before me an Indian species, and there are 
apparently three distinct forms from Japan. Well- 
marked differences are wanting amongst all these insects, 
which are almost identical in structure and sculpture ; 
and the difference of appearance which can be seen in 
comparison of examples vanishes in the most elusive way 
when an attempt is made to define and embody it in a 
description. 
It is possible that the structure of the male organs will 
be of assistance here, as Lindeman has shown that they 
are often distinct in closely-allied Scolytids. But for 
satisfactory examination of these, series of a certain length 
are required, and have not been forthcoming. I can 
therefore but echo the words of Leconte who, in treating 
of the almost equally difficult genus Dendroctonus, wrote : 
“Tf I have failed to indicate more strongly the differences 
