PLECOPTEKA OF NORTH AMERICA 207 



Nemoura cornuta Claassen. 



(Plate 35, figs. 13-15.) 

 1923. Nemoura cornuta Claassen, Can. Ent., 55:285. 



Male. Length to tip of wings, 7.5 mm.; expanse, 12.5 

 mm. 



General color brown. Head wider than prothorax ; hind 

 ocelli closer to eyes than to each other. Prothorax brown, 

 narrow, a little longer than wide, surface somewhat ru- 

 gose; sides straight, angles rather narrowly rounded. 

 Legs uniformly brown. Wings uniformly hyaline; anal 

 field and hind wings large. Two groups of gills in the 

 cervical region. 



Subanal lobes prolonged into irregular chitinized proc- 

 esses bluntly pointed ; cerci membranous ; above the cer- 

 ci a horn-like chitinized process about as long as the 

 cercus ; supra-anal process recurved, slender, membranous 

 above, chitinized below ; sugenital plate rather short, the 

 tip truncate; ventral lobe slender, about four times as 

 long as wide. 



Female, unknown. 



Holotype, male, June 22, 1920, Nanaimo, B. C, Biologi- 

 cal Station (E. P. Van Duzee). In the Collection of the 

 California Academy of Sciences. 



Nemoura californica Claassen. 



(Plate 35, figs. 16-19.) 

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



Length to tip of wings, male, 8 mm.; female, 8.5 mm. 

 Expanse, male, 14.5 mm. ; female, 15 mm. 



General color brown. Head a little wider than pro- 

 thorax, uniformly dark brown; hind ocelli at least twice 

 as close to eyes as to each other. Prothorax uniformly 

 brown, wider than long, somewhat narrowed behind, sur- 

 face nearly smooth, angles rather narrowly rounded. Legs 

 brown. Wings subhyaline; anal field of hind wings nar- 

 row. Gills present in four groups of filaments in cervical 

 region. 



Male. Subanal lobes wide, produced, upcurved and bear- 

 ing before the apex a short tooth ; cerci membranous ; at 

 base of cerci a short inward pointing, chitinous horn; 

 supra-anal process recurved ; much widened beyond base, 

 the membranous portion finely spinulose ; subgenital plate 

 quite short; ventral lobe narrow, at least three times as 

 long as wide. 



Female. Seventh sternite unmodified; eighth sternite 



