Rhynchophorous Coleoptera of Japan. 55 
Oryphalus and Pityophthorus with one species each, and 
Tomicus with two, are poorly represented, and are likely 
to be augmented by future collectors. The Platypini 
consist of nine species in three genera. 
In origin the Japanese Scolytide are partly Palearctic 
and partly Oriental. From the former region come 
Hylastes attenuatus and glabratus, Myclophilus piniperda 
and minor, Crypturgus pusillus, Tomicus cembre, Dryo- 
cates autographus, and Urypedendrow quercus; Xyle- 
borus adumbratus, m., and sobrinus, Hichh., are little 
more than varieties of X. pfeili and saxesent respectively. 
Little is known of N. Asiatic Scolytide and further 
identifications cannot be made. The only Oriental species 
I have recognised are X. obliquecauda, Motsch., which 
occurs in Ceylon, and X. badius, Kichh.; but in many 
other Xylebori, and in the genera Spheerot trypes, Cos- 
moderes, Crossotarsus, and Diapus, we have character- 
istically Oriental forms. There are no American species 
among them, though in one or two genera, as NScolytus, 
[have not sufficient material from America to institute 
a comparison; and none of the few Hawaiian species 
described by Dr. Sharp are to be found. 
Though our knowledge of Asiatic Scolytide is so im- 
perfect as to render such conjectures hazardous, I am 
inclined to think that Oriental forms predominate. ’ There 
is no tendency of the Palearctic species to be confined 
to the northern islands of the Archipelago. 
In describing these small insects it is important to 
obtain all measurements exactly, whether of the total 
length or of the relative dimensions. Hstimation with the 
eye of the comparative width and length of a prothorax 
leads to error, as do rough measurements of length. 
Chapuis gives the length of Phlwosinus perlatus as 
2mm., whereas the type measures 3 mm., that 1s, 50 per 
cent. longer. Such an error in the measurement of a 
species an inch long would be gross, and it is hardly less 
so when made about a smallinsect. Exceptin a few genera, 
as Scolytus, the range of size does not exceed one fourth 
of the average length, and may be much smaller. 
I have taken all measurements with a micrometer eye- 
piece, and a mechanical microscope stage fitted with a 
scale reading to 1-10th mm. ‘This method is quite exact, 
and speedy in practice. 
