230 THE CANADIAN ENTOMOLOGIST. 



Face strongly concave below the antennae Baroni. 



7. Shining portion of the abdomen steel-blue ; pile of the front light- 



coloured chalybescens. 



Shining portion of the abdomen metallic-green ; pile of front 



black occidenialis. 



8. Legs black ; at most, the knees lighter 9 



Tibiae at least largely yellow 14 



9. Third antennal joint black 27 



Third antennal joint brown, yellow or reddish-yellow 10 



ID. Arista plumose 11 



Arista bare 13 



11. Third antennal joint reddish-brown ; arista loosely plumose; general 



colour blackish ; antennte moderate in size (female) .... WUlistoni. 

 Third antennal joint bright reddish-yellow 12 



12. Arista densely plumose ; general Qolour blackish ; dorsum of thorax 



(female) yellowish pilose ; third antennal joint very large 



(female) signatiseta, n. sp. 



Arista loosely plumose ; general colour blue ; dorsum of the thorax 

 (female) not black pilose, but black pubescent (viewed from in 

 front) cyanea, n. sp. 



13. Third antennal joint reddish-brown or brown; rounded; tegul^e 



black ciliate ; wings blackish in front jiigripennis. 



Third antennal joint reddish-yellow, subquadrate ; tegulse white 



ciliate ; wings not blackish in front versipellis. 



I 4. Scutellum without bristles or bristlelike hairs on the margin 15 



Scutellum with bristles or bristlelike hairs on the margin . . 18 



15. Posterior femora largely reddish, or at least so coloured at the 



base 23 



Posterior femora, except the tip, always black 16 



16. Abdomen entirely shining in both sexes comosa. 



Abdomen, at least in the male, largely opaque 17 



17. Four anterior tibia? entirely yellow ; pile of front light- 



coloured capillata. 



Four anterior tibiae yellow only at apex and base ; pile of front 



black tarda. 



18. Arista briefly pubescent 19 



Arista plumose or long pilose 20 



1 9. Femora yellow prima. 



Femora largely black or brown 24 



