10. 
1DK 
12. 
13. 
14. 
PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
Pile of body largely black; first antennal joint rather thick.... pavida Coquillett. 
Pile of body largely white; first antennal joint rather slender .......-.-... 26. 
. Upper fork of Rs strongly bent; tropical species............ senilis (Fabricius). 
Upper fork of Rs not strongly bent; species of more northern distribution.. 27. 
. Third antennal joint very short; pile of the genitalia whitish.. baccata Coquillett. 
Third antennal joint about as long as the first and second combined. 
argentifrons, new species. 
+ TABLE OF FEMALES. 
Only lower corners of frons silvery pollinose, the rest shining black and more 
or less convex; cell M-3 closed and petiolate (haemorrhoidalis group).....- 2 
Frons largely covered with pollen, usually entirely so. ~— bigtht3h 5.50 8 
Femora yellowish brown.........-.. johnsoni Coquillett; eet (Wiedemann). 
Femora*black'rsr 52252.) 2 232 3 Sr ae ee ee ee eee 3. 
Halteres yellow... sg Bethe bites eters DRUMS eta netne eters Ghee ae 
Halteres black, at Teast the eee places. AAI ie let pigt GORA) Mabked alas hgh Lge rie 
Halteres brownish yellow, not bright yellow; tomentumlike pile of mesonotum 
and scutellum golden; eastern species............. flavipennis, new species. 
Halteres bright yellow.......-... PENIS. Nes 
Mesonotum dense gray pollinose i in itis cena ark pet margins Bane black; 
front tibiae entirely black; wings yellowish and pale brownish. 
lateralis Adams. 
Mesonotum not marked thus, with whitish vittae; base of tibiae reddish. - 6. 
Upper half of frons gray pollinose.....-.. Cereus laevigata juste 
Frons almost entirely shining black; Prhomere rite very distinct: wing veins 
very pale yellow........- hectare aldrichi Coquillett. 
First two joints of antennae mellerrict mode een species. 
arizonensis, new species. 
Hirst/t wodeinte or antennae: blacker... ese). tt nh ene cee ae eee 8. 
Wings with a distinct blackish discal spot; legs entirely black in typical speci- 
mens; halteres wholly black....-........ ....-. signatipennis, new species. 
Wings mae an inconspicuous discal spot or generally infuscated; all tibiae usu- 
ally-reddishrat base sis rs che noes toes pele a eee ee eee 9. 
Front tibiae black, base of hind tibiae reddish; costal cell blackish brown. 
costalis Loew. 
All the tibiae reddish at the base.. = sat | 
Lower corners of frons with a erianele! of sicaer pollen reaching ip Fanin fe face; 
mesonotum with a blackish median vitta; species found east of the Racky 
SN Von ao ets PSN SWANS SRI WD A OR erate haemorrhoidalis (Macquart). 
Lower corner of frons not with a silvery triangle, a narrow strip reaching from the 
face a short distance up along the eye margin.........---- --------.---- i, 
Wings largely infuscated ; mesonotum with a faint median vitta; western species. 
platancala Loew. 
Wings hyaline except for a small discal spot; mesonotum with a distinct dark 
median vitta ; eastern species.....- hoa epaipsbaaete sepcer 2 frontalis, new species. 
Upper two-thirds of frons shining black, the lower third silvery pollinose ; anten- 
maelratheristort, - oo 25 <<... ae? PONE, Ph e654), eet as 
Frons entirely pelle! erieames aaa danke pectic 5 L ARTA BEES 14. 
Upper part of frons seuss Wie the lower part bare of pile ; base of tibiae 
reddish. . Mh ecceeclene WH) . munda Loew. 
Upper part of one cae Sati a vaneaeaal en meeneeal fe. the lower portion with 
a few short black pile; legs black...............-.-..... melampodia Loew. 
Prons wath vervet: black spots. cis.ic «i sot Meee: cic obs caserneede cee soe EO 
Frons without tblick spots P00 %i 2 See eae dots he eis elaieal aera sete cleteys eee eneeE 
