PLECOPTERA OF NORTH AMERICA 205 



Nemoura biloba Claassen. 



(Plate 35, figs. 1-4.) 

 1923. Nemoura liloba Claassen, Can. Ent., 55:282. 



Length to tip of wings, male, 8.5 mm. ; female, 9 mm. 

 Expanse, male, 17 mm. ; female, 18 mm. 



General color brown. Head a little wider than pro- 

 thorax, uniformly brown ; hind ocelli about twice as close 

 to eyes as to each other. Prothorax wider than long, 

 somewhat rugose, a little widened behind ; angles nar- 

 rowly rounded. Legs brown, the femora somewhat dark- 

 er toward the end. Wings uniformly subhyaline; anal 

 field of hind wings large. Gills present. 



Male. Subanal lobes prolonged, upcurved and at the 

 tip divided into two slender processes; cerci large mem- 

 branous ; at base of cerci an inward pointing, short, mem- 

 branous, oblong lobe, suggestive of a second small pair; 

 supra-anal process recurved, slender, membranous above ; 

 subgenital plate somewhat prolonged ; ventral lobe a little 

 more than twice as long as wide. 



Female. Seventh sternite very slightly produced pos- 

 teriorly ; eighth sternite with a narrow median notch. 



Holotype male, allotype female, and one paratype, Los 

 Angeles Co., California (Cornell University Collection). 



Nemoura flexura Claassen. 



(Plate 35, figs. 5-8.) 

 1923. Nemoura flexura Claassen, Can. Ent., 55:284. 



Length to tip of wings, male, 6.5-7 mm.; female, 8-9 

 mm. Expanse, male, 10.5-11 mm.; female, 13-14 mm. 



General color brown. 



Head wider than prothorax, darker than prothorax; 

 occiput slightly rugose; hind ocelli about twice as close 

 to eyes as to each other. 



Prothorax wider than long, narrowed behind, quite ru- 

 gose, the rugosities rather coarse; angles quite broadly 

 rounded. Legs brown, wings uniformly subhyaline ; anal 

 field of hind wings narrow. 



Male. Subanal lobes produced into slender flexuous 

 processes which are upturned ; cerci membranous ; at base 

 of cerci originates a lobe suggestive of a second pair; 

 supra-anal process slender, recurved, membranous above 

 near tip; subgenital plate short; ventral lobe slender, 

 about three times as long as wide. 



Female. Seventh sternite somewhat produced, almost 

 tuberculate in the middle; eighth sternite with a deep 

 median notch. 



