238 THOMAS SAY FOUNDATION 



3. Subgenital plate without a ventral appendage 



parvuia 



Subgenital plate with a ventral appendage 4 



4. Hind femora armed with a strong tooth maura 



Hind femora unarmed nivalis 



5. Hind margin of subgenital plate with a flattened 



narrow prolongation turned up at a right 

 angle; ninth abdominal tergite bears two rear- 

 ward pointing lobes (subgenus Rhabdiopteryx 



Klap.) fasciata 



Hind margin of subgenital plate rounded or trun- 

 cate, without lobes or appendages (though sim- 

 ilar lobes are often present on the tenth tergite) 6 



6. No crossveins beyond the end of subcosta; sub- 



genital plate with a ventral appendage 



contorta 



A slanting crossvein just beyond the tip of sub- 

 costa; subgenital plate without a ventral ap- 

 pendage (subgenus Taenionema Bks.) 7 



7. Tenth abdominal tergite without two raised, rear- 



ward pointing appendages; lobes at base of 

 cerci in the form of sharp spine-like processes 



directed backward 8 



Tenth abdominal tergite with two raised rear- 

 ward pointing appendages; lobes at base of 

 cerci not sharply pointed 9 



8. Wings usually heavily infuscated, yellowish at 



the base ; supra-anal lobe gradually tapering to 



a point, length, 9-10 mm nigripennis 



Wings lightly infuscated, with a clear band across 

 the wing between the cord and tip; supra-anal 

 lobe enlarged towards the tip where it is 

 broadly rounded ; lobes at base of cerci very 

 slender, length, 12 mm. grinnelli 



9. Supra-anal lobe, viewed from above, deeply emar- 



ginate behind oregonensis 



Supra-anal lobe viewed from above not emargi- 



nate behind 10 



10. Supra-anal process broadly bifurcate (side view) 

 with a short tooth near the base of the bifurca- 

 tion; lobes at base of cerci finely granulate 



calif orn ica 



Supra-anal process not bifurcate at tip; lobes at 

 base of cerci very coarsely granulate pacifica 



