133 INSECUTOR INSCITI^ MENSTRUUS 



Face greater than one-third the width of head; facial strips 

 broad (Idaho, Washington) cyanea Hunter. 



5. Face distinctly longer than wide; pteropleura, besides the long 



black bristles, with yellowish pile (California) .townsendia Hunter. 

 Face about as broad as long ; pteropleura clothed with coarse 

 black hairs 6 



6. Anterior corners of second tergite with black pile; beyond this 



the lateral abdominal pile is luteous (California) . .willistoni Snow. 

 Sides of second tergite entirely black pilose ; third and fourth 

 tergites with alternating black and white patches 7 



7. Halteres and basal parts of wings infuscated ; third antennal 



joint reddish brown (Alaska) plutonia Hunter. 



Halteres yellow; wings hyaline; third antennal joint black 

 with a reddish brown spot (Idaho) idahoa, n. sp. 



8. Margin of scutellum with bristles 9 



Margin of scutellum without bristles 19 



9. Face clothed with scattered pile; shining, very dark blue 



species (New Brunswick) sialia, n. sp. 



Face without pile except on lateral strips, general color black, 

 or greenish black 10 



10. Entirely black, including legs and antennae 11 



Tibiae and tarsi partly reddish brown 12 



11. Squamae with white cilia (Oregon, Washington) laez'is Bigot. 



Squamae with blackish cilia (Colorado). Recorded as laevis 



Bigot by Jones, but may prove to be the male of lucta Snow. luctaJ 



12. Antennal pits separated ; squamae white with white cilia 13 



Antennal pits confluent 15 



13. Lateral facial strips about three times diameter of arista 



(Europe) pulchripes Lw. 



Lateral facial strips much broader 14 



14. Apical cross-vein turning upward, forming right angles with 



third vein (Alaska) hesperia, n. sp. 



Apical cross-vein forming an acute angle with third vein 



(Alaska) kincaidia, n. sp. 



15. Femora largely yellow (Virginia, Maryland, New Jersey, 



New Hampshire) paUipes Lw. 



Femora black with yellowish apices 16 



16. Hind metatarsus swollen, larger than posterior tibia ; third 



antennal joint reddish yellow (Virginia, Maryland, Pennsyl- 

 vania, New Jersey, New York) similis Shann. 



Hind metatarsus equal in girth to hind tibia 18 



17. Arista bare (apparently closest related to pallipes group), 



(Ontario) Ontario Curran. 



Arista pubescent IS 



