158 



Jewett: Plecoptera 



Fig. 6:6. Hind leg of: a, Leucrra c/aasseni; b, Taeniopteryx 

 maura (Frison, 1935). 



sternite of female produced over the 8th and with a 



canal opening beneath it; western North America 



Perlomyia Banks 1906 



— Vein Rs in the fore wing arising from R beyond the 

 origin of M (fig. 6:7a, to); male 9th sternite somewhat 

 produced and usually broadly rounded, never sharply 

 upturned; 7th sternite of female not produced 8 



8. Anal area of hind wing with 6 long veins (fig. 6:7m); 

 female with 8th or 9th sternites greatly elongated 

 and laterally compressed (fig. 6:256); male with a long 

 recurved process developed from the 10th tergite near 

 the base of each cercus (fig. 6:25a) 



Megalevctra Neave 1934 



— Anal area of hind wing with only 3 long veins; genitalia 

 not as above Leuctra Stephens 1835 



9. Rj of fore wing bent abruptly upward at its origin; 

 first anal vein of fore wing bent abruptly caudad at its 



Fig. 6:7. Wings of stoneflies. o-h, fore wing; i-m, fore and hind wings, a, Leuctra claasseni; 

 b, Nemoura besametsa; c, Isocapnia sp.; d, Perlomyia utahensis; e, Capnia projecta; f, A//o- 

 capnia sp.; g, Nemocapnia sp.; h, Eucapnopsis brevicauda; i, Isogenus frontalis colubrinus; 

 j, Perlesta placida; k, Alloperla borealis; I, Arcynopteryx aurea; m, Megaleuctra spectabilis 

 {a, Frison, 1935; b,c, Ricker, 1943; d,i,j,k,l, Needham and Claossen, 1925; e,h, Frison, 1937; 

 f,g, Hanson, 1946; m, Neave, 1934). 



