PLECOPTERA OF XORTH AMERICA 



237 



line to inf uscated ; radial sector with two or three 

 branches ; f orewing with 5-12 cubital crossveins, and with 

 the second anal vein forked ; anal field of hind wings large. 



Abdomen cylindric, dark brown 

 or blackish ; cerci in males with one 

 to six segments, in females with 

 five or six segments. 



Male. Supra-anal lobe short, up- 

 turned in the form of a probe ; sub- 

 anal lobes mostly modified into ac- 

 cessory copulatory organs ; ninth 

 abdominal sternite usually pro- 

 longed into a subgenital plate 

 which often bears at the base a 

 small ventral appendage. 



Female. Eighth abdominal ster- 

 nite unmodified ; genital opening 

 mostly near the middle of the 

 eighth sternite; ninth sternite 

 slightly produced in some species 

 while in others it is prolonged 

 greatly into a ventral plate which 

 reaches to the tip of the abdomen 

 or even beyond. 



Genotype, Taeniopteryx trifasciata 

 Pict. (European). 



Fig. 27. Taenio'pteryx 



nivalis Fitch. 



Key to the Species of Taeniopteryx. 



Males. 



1. Two ocelli, wings spotted, subgenital plate keel- 



shaped (subgenus Doddsia subg. no v.) 



occidentalis 



Three ocelli, wings clear or infuscated but not 

 banded; subgenital plate flattened or rounded 

 below 2 



2. Cerci composed of a single segment; subgenital 



plate moderately long; supra-anal lobe short, 

 bluntly pointed, sub-anal lobes symmetrical, no 

 costal crossvein immediately beyond the cord 



(subgenus Nephelopteryx Klap.) 3 



Cerci composed of four to six segments ; subgen- 

 ital plate greatly prolonged ; supra-anal lobe va- 

 riously modified;. subanal lobes asymmetrical; a 

 slanting costal crossvein just beyond the cord _ 5 



