922 P. CAMERON, HYMENOPTERA OF THE DUTCH EXPEDITION 
finely, elosely longitudinally striated. Median segment finely 
closely rugosely punctured, the apical slope irregularly trans- 
versely striated. There is an irregular yellow mark on the 
apex of the hind coxæ above. 
Closely allied to S. Bruinjnü and to the Assamese S. tibiale 
Cam.; may be known from both by the red abdominal petiole. 
Psenulus ? iuterstitialis sp. nov. 
Rufo-testaceous, the thorax and 4 anterior legs much paler 
in colour; the head black, the mandibles, except at the apex, 
and the palpi whitish; wings hyaline, the costa and stigma 
testaceous, the nervures darker coloured, the 1°! recurrent 
nervure interstitial with the 1° transverse cubital nervure, 
the 214 received shortly beyond the 214 transverse cubital. 9. 
Length 9 m.m. 
Etna Bay. 
Smooth and shining, the head more opaque, alutaceous 
above, the face, oral region and lower part of outer orbits 
densely covered with silvery pubescence, the rest of the head 
more sparsely with pale hair; apex of clypeus broadlv rounded, 
margined. Antenne stout; the 3" joint 3 times longer than 
the scape and about one fourth longer than the 4; the 
flagellum is darker coloured above; they are placed distinctly 
above the middle of the eyes. There is a fine furrow in the 
centre of the front. In the centre of the base of the metanotum 
there is a distinct transverse depression, widened in the middle; 
with 2 stout diverging, testaceous keels in the middle and 
with 5 shorter black ones on eitherside, and leading below 
into the central longitudinal furrow, which is wider and 
shallower at the apex. Abdominal petiole long, curved, as long 
as the mesonotum, its apex dilated, becoming een wider 
from the base to the apex. 
This is not a typical Psen or Psenulus ; it differs from both 
in the interstitial 15* recurrent nervure and in the 224 cubital 
