HYMEN OP TERA. 



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 



Ill, 



FIG. 755. Wings of Aulacus. 



/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. 



FJG. 756. Wings of Fcenw. 



In the more generalized members of the family, as Aulacus 

 (Au'la-cus), the origin of vein V is but a little way from the 



