PLECOPTERA OE NORTH AMERICA 209 



Nemoura venusta Banks. 



(Plate 36, figs. 5-8.) 

 1911. Nemoura venusta Banks, Trans. Am. Ent. Soc, 37:337. 



Length to tip of wings, male, 7-7.5 mm. ; female, 8.5-10 

 mm. Expanse, male, 12-13 mm. ; female, 14-18 mm. 



General color dark brown. Head wider than prothorax ; 

 hind ocelli at least twice as close to eyes as to each other. 

 Prothorax almost as long as wide, hardly narrowed be- 

 hind, angles rather broadly rounded. Wings infuscated 

 but with about thirty clear rounded spots distributed 

 quite regularly over the entire wing; anal field of hind 

 wings narrow. Gills present. 



Male. Subanal lobes divided into two unequal chiti- 

 nized bands, the outer lobe only about half as long as the 

 inner which is membranous on the inside ; both bands are 

 armed with stout spines ; cerci membranous ; supra-anal 

 process recurved, armed with spines underneath ; subgen- 

 ital plate rather short; ventral lobe narrow, about four 

 times as long as wide. 



Female. Seventh sternite produced over entire eighth 

 segment as a large broadly rounded subgenital plate ; gen- 

 ital opening of eighth sternite guarded by two short, trun- 

 cate lobes. 



Type, female, No. 11357, Huachuca Mts., Ariz. (Banks 

 Collection, Mus. Comp. Zool., Cambridge, Mass.) ; Boulder, 

 Colo. (G. S. Dodds) ; Aug. 10, 1919, Estes Park, Colo. (P. 

 W. Claassen). 



Nemoura venosa Banks. 



(Plate 36, figs. 9-12.) 

 1891. Nemoura venosa Banks, Trans. Am. Ent. Soc, 24:21. 

 1904. Nemoura. venosa Banks, Proc. Ent. Soc. Wash., 6:205. 

 1907. Nemoura venosa Banks, Cat. Neurop., p. 14. 

 1920. Nemoura stylata Banks, Bull. Mus. Comp. Zool., 64:324. 



Length to tip of wings, male, 7 mm. ; female, 7.5 mm. 

 Expanse, male, 12 mm. ; female, 13.5 mm. 



General color blackish brown. Head blackish, wider 

 than prothorax, hind ocelli closer to eyes than to each 

 other. Prothorax quadrangular, little wider than long, 

 hardly narrowed behind ; angles rounded. Wings quite 

 heavily infuscated, sometimes almost black; anal field of 

 hind wings narrow. 



Male. Subanal lobes divided into two chitinized upcurved 

 bands, the inner longer and at the tip membranous on the 

 inside, both bands armed with spines ; cerci membranous ; 

 supra-anal process recurved, armed underneath with 

 heavy spines ; subgenital plate not much produced ; ven- 

 tral lobe at least three times as long as wide. 



