142 Annals Entomological Society of America [Vol.11, 



7. Ovipositor short, conical, with four spines on the upper side at the 



apex, upper forceps of the male genitalia excavated on the apical 

 part so that when viewed from above there is a distinct open space 



between them 8. 



No spines at the tip of the ovipositor 13. 



8. Legs in large part reddish 9. 



At least the femora of all the legs black 12. 



9. Largest species falling under 7, wings smoky, legs dark red, abdomen 



pure black banded with gray arizonensis Will. 



Smaller species, wings hyaline or reddish, abdomen gray black band- 

 ed with gray 10. 



10. Wings limpid, legs pale reddish, brown of fuscus in places 



limpidipennis n. sp. 

 Wings reddish, legs pale reddish, usually black in places 11. 



11. Legs rather slender, anterior side of each femur in large part black, 



upper forceps of the male genitalia with the angle at the beginning 

 of the excavation produced inward and backward so that it meets 



and crosses its fellow of the opposite side truquii Bell 



Legs rather thick, each femur black except at the tip of the anterior 



side, angle of the upper forceps not produced rufipennis Hine 



12. Legs, except the extreme bases of the tibiae, black tuxpanganus Bell. 



Tibiae and tarsi in large part reddish fuscatus n. name. 



13. Arista of the antenna about twice as long as the third antennal seg- 



ment, legs almost entirely pale reddish gracilis Wied. 



Arista at most only a little longer than the third antennal segment, 

 legs usually partly black 14. 



14. Four or more bristles on the margin of the scutellum, ground color of 



the abdomen, except in one species, clear black 15. 



Normally two bristles on the margin of the scutellum. These bristles 

 may he variable to the extent of having one or two additional 

 smaller ones in an occasional specimen of a species 23. 



15. Wings glassy hayline, legs in part bright yellow, Sixth and seventh 



segments of the female abdomen shining black, that is, included in 



the ovipositor 18. 



Wings partly brownish, legs in part pale reddish. Sixth and seventh 

 segments of the female abdomen not included in the ovipositor. .16. 



16. Dark gray species with gray posterior margins to the abdominal seg- 



ments. Posterior margin of the eighth ventral abdominal segment 



produced and furnished with a dense tuft of coarse hairs 



occidentalis n. sp. 

 Black species. Posterior margin of the eighth ventral abdominal 

 segment not produced and not furnished with a tuft of hairs. . . . 17. 



17. Shining black species with golden posterior margins to the abdomi- 



nal segments auriannulatus Hine 



Rather dull black species with gray posterior margins to the abdomi- 

 nal segments callidus Will. 



18. Hairs of the face, mystax, bright yellow. Male forceps notched 



on the upper side at the apex 19. 



Mystax wholly or in part black or white, or else the male forceps 

 not notched on the upper side at the apex 20 . 



19. All the femora black orphne Walker 



Front and middle femora almost entii-ely yellow affinis Will. 



20. Front and middle femora yellow, each with a black stripe on the 



upper side flavofemoratus n. name 



All the femora black, at most with only a preapical band yellow. . . .21. 



21. J\lale forceps notched on the upper side at the apex 22. 



Male forceps not notched on the upper side at the apex. . . .terminalis n. sp. 



