Vol. XI] CURRAN— REVISION OF THE PIPIZA GROUP 359 



Pile of venter mostly erect 9 



7. Pile of venter sub-appressed auripleura 

 Pile of venter appressed 8 



8. Median depression of frons transverse, broad, entire; wings ciner- 



eous hyaline pisticoides 



Median depression of frons appearing circular; wings somewhat 



brownish, (western) albipleura 



9. Middle tibiae with distinct groove below intermedia 

 Middle tibiae not distinctly grooved below 10 



10. Third joint of antennae extremely large, obtusely oval; face with 



some black hairs on sides cevelata 



Third joint more elongate, sub-rectangular 1 1 



11. Last section of fifth vein nearly straight; third antcnnal joint 



brownish above coxalis 

 Last section of fifth vein bent at its middle; third antennal joint 



black above calcarata 



12. Thorax shining brassy myerma 

 Thorax shining black 13 



13. Wings tinged with luteous ontarioensis 

 Wings cinereous hyaline, (smaller) venteris 



The above key to the females is confessedly unsatis- 

 factory, yet it is the best that I can devise at the present 

 time. The females are evidently different, yet present 

 so few characters which are available for a key that ex- 

 ceptional difficulty is encountered. I might add that 

 the antennae differ in all the species, as well as the coxal 

 spurs and amount of production of the middle tibiae, 

 but it is apparent that these characters are of use only 

 for comparison. I still have several females in my col- 

 lection which are not named as I consider that the 

 naming of unlocated females, unless their characters 

 are outstanding, will merely lead to confusion as has 

 been the case in the past. 



The true relationship of the females in many' cases 

 can be determined only by rearing or capture of speci- 

 mens in copulation. I secured one pair of C. venteris 

 in this latter state. In studying the females the 

 student must rely largely upon his sense of fitness in 

 determining their relationship [to^the males. The jfe- 

 males of the common species will be readily placed by 

 careful collecting and labelling. A careful comparison 

 with the figures in this work will also be of some help. 



14. Cnemodon unicolor, new species (Figs. 13, 44) 



Habitat: Ontario! Male: Length, 6 mm. Face and frons shining black, 

 black pilose; face almost straight from antennae to oral margin but slightly 

 rounded above, sides whitish pollinose; frons opaque above; antennae black; 

 third joint bright yellow below, as broad as long; arista black; vertical triangle, 

 post orbital cilia, and eyes black pilose, the latter whitish pilose below. Thorax 



