268 ENTOMOLOGICAL NEWS [Nov., '22 



greater part of center of disc of both fifth and fourth sternites with 

 short stubby spines ; hind tibia produced scooplike at apex on 



ventral side keeniana Williston. 



Fifth abdominal sternite with a central concavity in posterior margin, 

 the left posterior angle drawn out into a rounded lobe; hind tibia 

 transverse at apex on ventral side 8 



8. Black spinules of fourth sternite conspicuous, stubby, extending well 

 on to disc; fifth tergite with a large rounded lobe; fourth tergite 

 without long hairs on posterior lateral angles lobata Loew. 



Black spinules on fourth sternite very sparse and fine, confined to 

 extreme margin of haired part ; fifth tergite with a small rounded 

 lobe ; fourth tergite with long soft hairs on each posterior lateral 

 angle punctata Cole. 



9. Spinules of fifth sternite black and stubby, many fine hairs laterad of 

 them on the two rounded slightly elevated areas, .rufiventris Loew. 



Spinules of fifth sternite reddish, elongated on the two rounded ele- 

 vations laterad of the median line 10 



10. Fifth sternite with a very large rounded lobe on left side at pos- 

 terior angle which is not heavily chitinized and is separated from 

 remainder of segment by a depression, the hairs long and not very 

 strong ; outer crossvein and fourth vein beyond bend at apex inf us- 

 cated petiolata Coquillett. 



Fifth sternite with a small rounded lobe which is as heavily 

 chitinized as the remainder of segment and not separated from it by 

 a depression, the hairs shorter and stronger ; veins not infus- 

 cated campanulata Robertson. 



11. Hairs on frons erect, conspicuous, the longest as long as the entire 

 antenna : abdomen inconspicuously pedunculate ; arista very little 

 longer than antenna, densely pubescent infuscata Loew. 



Hairs of frons decumbent, short and inconspicuous, the longest not 

 longer than second antennal segment ; abdomen conspicuously pe- 

 dunculate 12 



12. Fifth abdominal sternite with a large lobe at right hind angle which 

 is over half as long as the sternite at middle; only the apical seg- 

 ment of tarsi deep black, the subapical one brownish lobulifera sp. n. 



Fifth abdominal sternite not distinctly lobed as above 1,> 



1.1 Hind tibia with a slight but distinct scooplike production of the 

 ventral surface apically ; arista gradually tapered from base an-1 

 distinctly pubescent ; small species, 5-6 mm. in length, 



flavimana Malloch. 



Hind tibia not produced as above, transverse at apex ; arista swollen 

 on about a fourth of its length from base and nearly bare ; larger 

 species, 8 mm. in length californica Malloch. 



Key to Females. 



1. Third (fourth) tergite of abdomen distinctly flared apically, fourth 

 with a deep notch in middle of posterior margin ; the curved linear 



