XXXVlll INTRODUCTION. 



the lower extremity be the nearer thereto. In the first of these cases the 

 nervellus^ is emitted from below the centre of the nervure, as in the 

 Ichneumoninae, in the second from its centre, and in the last from above 

 its centre, always at the point of angulation. 



Between these nervures are an inner and an outer series of four cells, 

 of which I is the costal,- 2 ^ and 3 "* the basal, 4 the anal,'"* 5 the radial, 

 6 the cubital, 7 and 8 the first and second discoidal." The discoidal are 

 often no more divided than is the anal cell by the humeral nervure. 



In common with Hymenoptera in general, the hind wings are anteriorly 

 provided with a series of hooks (disproportionately conspicuous in the 

 figure), which clasps and steadies the fore wing in flight, and rises from the 

 hakenkamm, which extends from the anterior nervure to the apex of the 

 wing. 



1 Nervellus or nervus spurius, Thorns. ; nervule additionnel, Berth. 



'i Brachial, Berth. 



s Pre-brachial, Bridf<. -Fitch ; costal, Berth. 



4 Pobrachial, Bridg. -Fitch ; median, Berth. 



5 Axillary, nee anal, Bridg.-Fitch ; anale, Berth. 



fi These two are collectively the posterior of Berth., and individually the discoidal and anal of 

 Bridg.-Fitch. 



