78 p. CAMEEOX, ox the MALAY ÏOSSORIAL HYMENOPTERA AXD VESPIDtE, 



metauotum broadly rounded, not much dilated ; the sides bear 

 au oblique tooth. Basal half of 1"' abdominal segment narrow 

 at the base, becoming gradually widened towards the apex. 

 The 2'"' cubital cellule greatly narrowed in front, the 3'^'' of 

 equal width throughout. 



Belongs to the Division Leionotus. The base of the thorax 

 is quite transverse ; the body is covered by a white pile. It 

 is not unlike 0. bipimctulcdus ; but the cT of that species is 

 readily separated by its clypeus being not much longer than 

 wide ; while in Drescheri it is distinctly — almost twice — 

 longer than wide. 0. lybas Cam. from Borneo has the 

 thorax not so transverse, not distinctly angled at the base, 

 and otherwise is readily separated by the difference in the 

 form of the basal abdominal segment : in bjhm it rises obli- 

 quely from the base, then falls obliquely towards the apex ; 

 in the present species there is no oblique slope on the apex. 



The Ç of 0. Drescheri is similarly coloured ; the lateral 

 angles of the prothorax are somewhat more rounded ; the 

 clypeus is broadly rounded above ; the apical half from the 

 eyes are roundly narrowed to a point, which is bordered with 

 black and triangularly incised ; in the centre of the apical 

 half is a large mark, broad above, the top slightly depressed, 

 the sides rounded, narrowed below into a narrow line which 

 extends to the apex. Apex of antennae brownish below. The 

 above description is from an old ^ in my collection marked 

 »Java«. 



