ee 
256 Mr. F. W. Wdwards on 
This species is nearly allied to Ps. ctenophorina, Riedel, 
and Ps. fumiplena, Wlk., but is certainly distinct from both ; 
there is a slight str Genel difference in the antenne: Riedel 
describes those of Ps. ctenophorina as approaching those of 
Prionocera in structure, the flagellar joints being elongated 
on the underside ; in Ps. fumiplena this is true of the third 
and, perhaps, the fourth joints, though not of the remainder. 
In regard to coloration, Ps. semirufa is also well distinguished ; 
from Ps. ctenophorina in the blotched wings and the narrower 
white rings on the tibie; and from Ps. Jumiplena in the 
more extensive wing-markings and the greater amount of 
red on the abdomen. It is worth mentioning in this connec- 
tion that Ps. fumiplena as described by Osten-Sacken appears 
to consist of three allied species, two of which are bricfly 
characterized below under the names flavibasis and sackent. 
Pselliophora fumiplena, Wik. 
The British Museum series of this species consists of three 
males and five females, all labelled ‘ North China” ; they 
were all seen by Osten-Sacken, who quite correctly noted the 
variability in the wing-markings and in the amount of red on 
the third and fourth abdominal segments. In all the speci- 
mens the legs are black, all the tibia carrying conspicuous 
white subbasal rings; the fifth and following segments of the 
abdomen are entirely black; the base of the wing is entirely 
blackish, except in one specimen, which has some rather 
inconspicuous yellow streaks in this position; the male an- 
tenn are entirely black ; the third joint of the female antennze 
is rather distinctly produced below towards the tip; the 
halteres are black. 
The pair of bare black plates (/am. term. inf.?) visible 
about the middle of the hypopygium when seen in end-view 
are produced at their upper and inner corners into a long 
tooth-like process. In Ps. flavibasts and Ps. sackeni the 
hypopygium has an almost identical structure; Ps. cteno- 
phorina is very similar, but the tootlh-like process is very 
short, and there are some other differences. 
Pselhophora flavibasis, sp. n. 
There are three specimens in the British Museum collection : 
a male from Nagasaki, 8. Japan, May 1886 (Leech); a 
female from Lu-huang Island, Chusan Archipelago, May 
(J.J. Walker), and a second female simply labelled ‘* China,” 
which I regard as distinct from Ps. fumiplena. Only one of 
