88 
32. 
33. 
34. 
10. 
11. 
12. 
13. 
PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
Abdominal segments two to six shining black except for the narrow yellow bor- 
ders, the abdominal pile black - --+-+++--+--+----- brunnea, new species. 
Abdominal segments with broad polliness areas; the emis largely pollinose; 
pile of abdomen largely white or yellow........-. Bi be ee Sh 
Venter mostly yellow and the tergites of abdomen marked with yellow; thorax 
with a median pure black vitta and two gray vittae....... diversa Coquillett. 
Abdomen black in ground color; thorax not marked as above..........-.... 34. 
Mesonotum dull dark brown, with two yellowish vittae; wings with no clouds 
on the veins. oie -...---- ustulata Kréber. 
Mesonotum gray eEaehirsy a eNO ee ee wings with the cross veins 
clouded’... /2':$ 2222 252220232 socR si ecees tessa Neey GR eee rOMtalis AY. 
TABLE OF FEMALES. 
. Frons entirely pollinose, often with velvet black spots -........ sy ioral (ie 
Frons with a shining black curs or with one or two shining black marks. 14. 
Frons without; any black markingae Saat. tal A22byenker aes sep eee uae 
Frons with velvet black markings . : aah EAT et4 aay 
Small, Psilocephala-like species; =e a the Gace short; “Sine aac dese quien: 
tumlike pile; antennae yellow with a black style; femora yellow. 
semitaria Coquillett. 
Larger, more heavily built species; frons without tomentumlike pile; antennae 
black . Sree goa 32 ate : spe. fe 
Abdomen Eras shining lack: Sens pana black: lack aie Be fron. 
short and sparse.....- - ........-. borealis, new species. 
Abdomen largely seer alee ee eray Pollinose. Miche Se 28. 
Frons entirely whitish pollinose and white pilose.............- “albiceps Loew. 
Frons yellowish on upper part and black pilose. ats suietpooh a eae 
Knob of halteres largely white; reclinate pile of mesonotum syellowicte 
cinerascens, Dew species. 
Knob of halteres blackish; reclinate pile of mesonotum white. 
cockerelli, new species. 
No distinct frontal spots present, in certain ee a dark mark next the eye 
margin; femora yellow ....-. -- wxeets ote dese. Sella tKiraber 
Frontal spots larger and distinet. Eeuees iiinehes equtlensroiinvt ot peut sa Se 
Frontal markings consist of two round, velvet bine, Spots ic. tanh ee ee ee 
Frontal markings in the form of a crossband, interrupted or entire...-..... ll. 
Frontal markings consist of two triangular, velvet black spots, one on each side. 
nitoris Coquillett. 
Wing veins marked or bordered with brown; western species. 
otiosa Coquillett. 
Wing veins not bordered with brown a ss ise eke, Ue 
First antennal joint about as wide as the third: a eee 
vialis Osten Sacken. 
First antennal joint much thicker than the third; eastern species. 
bimaculata, new species. 
Bristles of vertex and occiput yellowish; thorax without black pile. 
novella Coquillett. 
Bristles of occiput and, vertex: black..2-: Shee: eeeeeeG cosh ee See 
Wing veins pale yellow; eastern species. ....-..-.---------- “candidata Loew. 
Wing veins black or brown; western ae snes ee ee 
Wings whitish hyaline, with no clouds on veins; Se of es anal thorax white. 
pacifica, new species. 
Wings with clouded cross veins; pile of face and thorax yellow. 
vanduzeei, new species. 
