272 



THOMAS SAY FOUNDATION 



veins often ending blindly ; subcosta short, usually not 

 reaching farther than to a point half way between the 

 origin of Rs and the cord; no crossvein beyond the end 

 of Sc, or if present it is very near the tip of Rl ; anal 

 field of hind wings large and nearly as long as the rest 

 of the wing. 



Abdomen blackish, cerci or tails long, 

 composed of many (fifteen or more) seg- 

 ments. 



Male. Supra-anal process recurved up- 

 on the dorsum of the abdomen and di- 

 vided into two parts, an upper chitinized 

 process which serves as a probe and a 

 lower excavated sheath in which the up- 

 per probe rests ; eighth abdominal ter- 

 gite usually bears a single or double 

 knob, under or against which the supra- 

 anal process fits ; ninth and tenth ab- 

 dominal tergites with a median longi- 

 tudinal groove in which the supra-anal 

 process normally lies (this results in the 

 bifid appearance of these two tergites) ; 

 subanal lobes small, somewhat tri- 

 angular ; ninth abdominal sternite 

 slightly produced and evenly rounded 

 behind, without any ventral appendage. 

 Female. Hind margin of eighth ab- 

 dominal sternite very little or not at all 

 produced; genital opening not guarded 

 by valves. 



Genotype, Capnella granulata Clsn. 

 There is considerable variation in the 

 length of the wings within the same 

 species. Venational characters serve for generic distinc- 

 tion but there is so much variation that they are of no 

 value in separating the species. The genitalia of the 

 males furnish excellent characters for specific determi- 

 nation ; however, in the females the genital structures are 

 of little value as key characters. No attempt is made to 

 furnish an analytic key for the determination of the fe- 

 males. 



Fig. 29. Capnella 

 pygmaea Burm. 



