ART. 4. REVISION OF THE FAMILY THEREVIDAE—COLE. 37 
15. 
16. 
ie 
18. 
9! 
20. 
21. 
23. 
24. 
25. 
26. 
Zils 
28. 
First three abdominal segments largely shining red ; frons very narrow and with 
two small black spots. - ve gates re) ie a re ome wel 
Abdomen not colored thus and fereely polinare. Ga SRR SANE Feces: So te ile 
Bristles of the body and the thoracic calli black......... aurantiaca Coquillett. 
Bristles of body and thoracic calli yellowish............. subrufa, new species. 
Lower angle of eye acute; wings erie dark gray, spotted white ; frontal black 
spots small; western species..-.....- cy _aeues Adams. 
Lower angle of eye acute ; cross veins clouded erik a Be oe wins on the veins; 
frontal spots large; tite upper part of frons darker than lower; eastern species. 
tergissa (Say). 
Lower angle of eye not acute ; R-4 not so deeply bent near aa as in tergissa and 
acuta; species with a narrower frons........ SA Lee 1S: 
Frons with a median black triangle in Raiden) to the Ste on aati side next the 
eyes; third antennal joint about as wide as the first, and longer. 
montivaga Coquillett. 
Frons with only two velvet black spots. .....- k «Lee ee oe Le 
First antennal joint distinctly wider than the third and about ¢ as sioag , with long 
black bristles; pile largely black. - PG ees cee Se eit -ppavida ACoquillert 
First antennal joint more slender faa the third area NPB 8 ts OO) 
Femora yellow; abdomen largely yellow...........-..--.-- slossoni Coquillett. 
Hemory black; abdomen black im ground olor... 0)0.00 0 0< = Sars ees 8 oe eee Aa op 
Knob of halteres and hypopygium black. 
cinerea, new species, baccata Coquillett. 
Knob of halteres and hypopygium yellow... ...............- morata Coquillett. 
Frons with two diverging lines of black from the base of the antennae; large 
boreal species, about 16 mm. in length; femora and tibiae black. 
grandis Johnson. 
Frons without any markings of this kind; smaller species.................- 2a 
Femora yellow ; abdomen largely yellow. ................... placida Coquillett. 
Bemora piackicgn brown Orvblaeko cues cos kU neha eetec oe cater a newer ee 24. 
Abdomen with reddish brown side spots and reddish apex ; hind femora deeply 
furrowed); tropical species’: » 222 s/s siaMelsoe- ee eyed ad ds xy |S@nilis; (Fabricius): 
Abdomen black in ground ae Hii ho 8. 25. 
First antennal joint greatly Seen end slegetslie bristled: Sheen than the third 
joint; a dark mark from the base of the antennae to the eye margin. ...... 26. 
First antennal joint smaller than the third............ STATS ie PA O84 
Pile of mesonotum short and black ; wings eels clouded Reston species. 
fuscipennis, new ane 
Pile of mesonotum yellow or golden.......... ale eet 
Scutellum with four bristles ; pile of ots and ETE aI ate eollowien: occi- 
pital bristles yellow .. pe -.---- variegata Loew. 
Scutellum with two bristles! Boat: ieediay bristles phe pile of thorax and frons 
largely golden yellow.. _....-...-- variegata flavipilosa, new subspecies. 
Broad posterior margin 2 ieeoads third, and fourth abdominal segments gray 
pollinose, fifth except narrow base ae all of sixth; upper frons gray brown 
pollinose ; western species... .... : . limata Coquillett. 
Posterior angles of second, anne fourth ial geal ahapaeaa segments gray pol- 
linose, fifth almost wholly so; upper frons thinly blackish brown pollinose; 
boreal species..........2...20..020...-....-..-... canadensis, new species. 
The HAEMORRHEOIDALIS group. 
There is a definite group in the genus Psilocephala which might be 
called the haemorrhoidalis group; it has several widespread species 
