PLECOPTERA OF NORTH AMERICA 217 



Nemoura washingtoniana Claassen. 



(Plate 38, figs. 12-1 5.) 

 1923. Nemoura washing! out Claassen, Can. Ent., 55:287. 



Length to tip of wings, male, 9.5-10 mm.; female, 11 

 mm. Expanse, male, 16-17 mm.; female 19 mm. 



General color dark brown. Head a little wider than pro- 

 thorax, uniformly brown ; hind ocelli closer to eyes than 

 to each other. Prothorax much wider than long, smooth, 

 somewhat narrowed behind ; front angles broadly 

 rounded, hind angles subacute. Wings uniformly subhy- 

 aline except for a slight infuscation at the stigma; 1st 

 and 2nd A of forewing united before the margin; anal 

 area of hind wing large. Gills apparently absent. 



Male. Subanal lobes very large, narrowed at base, up- 

 curved and produced into a triangular process at the up- 

 per inner angle; cerci very small, membranous. Supra- 

 anal process not recurved but produced backward and up- 

 ward, composed of a double sheath on each side, the in- 

 ner sheaths broad and armed with spines above, the outer 

 sheaths slender and unarmed ; subgenital plate long, very 

 hairy and turned up at a right angle ; ventral lobe large, 

 about twice as long as wide. 



Female. Seventh sternite produced backward into a 

 rounded subgenital plate which reaches beyond the hind 

 margin of segment eight; genital opening not guarded 

 by distinct valves. 



Holotype, male, June 15, 1877, Mt. Washington, N. H. 

 (Cornell University Collection) ; allotype, female, June 16, 

 1916, Glen House, N. H. (C. W. Johnson) ; two females, 

 June 14-16, 1916, Glen House, N. H. (C. W. Johnson). 



Nemoura interrupta Claassen. 



(Plate 38, figs. 16-18.) 

 1923. Nemoura interrupta Claassen, Can. Ent., 55:288. 



Length to tip of wings, male, 11.5 mm.; expanse, 19 

 mm. 



General color dark brown. Head wider than prothorax, 

 covered with rather long hair; hind ocelli closer to eyes 

 than to each other. 



Prothorax wider than long, somewhat narrowed be- 

 hind ; slightly rugose ; angles quite sharp. Legs uniformly 

 brown. Wings subhyaline, first and second A of forewing 

 united before margin ; anal field of hind wings large. Gills 

 apparently absent. 



Male. Subanal lobes prolonged and curved up at right 

 angles, constricted near the middle, the lobe beyond 



