HYMEN OP TER A. 
627 
that the abdomen is attached to the top of the metathorax, 
and not at the hind end of it, as with other insects. The 
abdomen is compressed, and has a very slender base. 
The venation of the wings also presents a striking pe¬ 
culiarity. In other Hymenoptera vein V of the fore wings 
/irises from some point on the cross-vein III VII that is 
nearer to vein III than to vein VII, while in the Evaniidae 
the origin of vein V is nearer to vein VII than to vein III. 
Tn the more generalized members of the family, as Aulacus 
(Au'la-cus), the origin of vein V is but a little way from the 
