Feb., 19^1 Bulletin of the Brooklyn Entomological Society 



homologous with the Cerci of the Neuropteroid and Orthop- 

 eroid insects. 



Discussion. 



A brief resume of those genera of the Hepialidae which were 

 studied will serve to contrast their respective characteristics as 

 well as to emphasize the generalized condition of the male geni- 

 talia in this- family. 



Hepialus. 



This genus seems to be the most primitive of those studied. 

 Sternum 8 is only slightly invaginated, forming a broad U-shaped 

 Vinculum, while the greater portion of it remains typical in shape 

 and position. Sternum 9 is a broad, pentagonal sclerite closely 

 associated with the Harps and only slightly fused with sternum 8. 

 Tergum 9 is a simple hood-like sclerite forming the dorsal wall 

 of the Tegumen and bearing a small pair of chitinous processes on 

 its ventral margin. Sternum 10 is a small square sclerite bearing 

 a median process (Appendage III) functioning as an intromittent 

 organ and foreshadowing the iEdoeagus of higher forms. The 

 Ductus Ejaculatorius opens caudad to sternum 10 just beneath 

 appendage III. Tergum 10 consists of two small sclerites latero- 

 dorsad to sternum 10 and articulating laterally with tergum 9. 

 Sternum and tergum 11 are absent. Species examined: Hepialus 

 lupulinus L. and H. gracilis Grt. (Fig. 2). 



Sthenopis. 



This genus resembles Hepialus quite closely in its main struc- 

 tural features. Sternum 8 is more deeply invaginated, the caudad 

 margin strongly emarginate around the Vinculum and the lateral 

 and cephalic margins of the sclerite are indistinct. The fusion of 

 sternum and tergum 10 with appendage III is more marked and 

 the resulting structure forms a suspensorium articulated laterally 

 to tergum 9. The Ductus Ejaculatorius which opens between the 

 arms of this suspensorium and appendage III is attenuated into a 

 triangular process. The chitinous processes of tergum 9 are 

 longer and more spinous than in Hepialus and are differentiated 



