272 THE CANADIAN ENTOMOLOGIST 



defined from the southern United States, Central or South America, Africa, 

 Australia or any part of Asia, though there is a likelihood of their occurrence in 

 Tibet. 



Key to Sfecies. 



MALES. 



1. Hind tibia with a strong fasciculate apical thorn on ventral side 2. 



Hind tibia without such thorn, sometimes with one or two bristles 3. 



2. Yellow species of robust habitus diaphanus Wiedemann. 



Black species of slender habitus '. coquilletii Malloch 



3. Legs largely or entirely yellow; hind tibia with setulose hairs and a few 



long bristles; thorax with two pairs of strong presutural acrostichals....4. 



Legs entirely black; hind tibia usually with long, soft hairs in addition to a 

 few hairlike bristles 5. 



4. Hind femur stout and straight, with rather long dense hairs on posterior 



and posteroventral surfaces; antennae black; mid tibia with one or two 

 anterodorsal bristles conformis Malloch. 



Hind femur slender, curved, with a few posteroventral bristles on apical 

 third; base of third antennal segment rufous; mid tibia without antero- 

 dorsal bristles latipennis Malloch. 



5. Abdomen with paired dorsal spots; hind tibia without posterodorsal 



bristles; thorax with three pairs of postsutural dorsocentral 



bristles maculiventris Ma lloch . 



Abdomen without paired dorsal spots; hind tibia with one or more postero- 

 dorsal bristles 6. 



6. Fore tibia with several strong spines on posteroventral surface near apex. 7 



Fore tibia without spinose armature as above, sometimes with a few hair- 

 like bristles 10. 



7. Fore tibial spines four in number, in a single series; mid tarsus without a 



fringe of fine hairs on apical threfe segments fimhriatus Coquillett. 



Fore tibia with the vspines in two vertical series; mid tarsus with a fringe 

 of fine hairs on posteroventral edge of the apical three segments 8. 



8. Fore tibia with three spines; mid tarsus long and slender, fourth segment 



at least twice as long as wide 9. 



Fore tibia with four spines; mid tarsus short and stout, fourth segment as 

 wide as long septentrionalis Stein. 



9. Halteres yellow; mid femur with a number of long hairs on basal half of 



posteroventral surface diffinis Malloch. 



Halteres black or brown; mid femur without such hairs spiniger Stein. 



Decembe.-, 1920 



