938 Tur BLowruizs or NortH AMERICA 
bristles on dorsal surface, one near basal third, one near middle, 
and usually one between apical third and fourth; middle femur 
with one anterior bristle near middle, three or four anteroven- 
tral bristles toward base, and with four posteroventral bristles 
toward base; middle tibia with one anterodorsal bristle at apical 
third, one ventral bristle near apical third, two posterior bristles, 
one near basal third and one near apical third, and one postero- 
dorsal bristle near apical third; hind tibia with from one to 
three anterodorsal bristles, always one at basal third, usually 
one at or near middle, and rarely with one near basal sixth, 
with one anteroventral bristle at or near apical third, and 
with two posterodorsal bristles, one near basal fourth and one 
near apical third. 
Wing hyaline, yellowish toward base, with yellow orange to 
orange brown veins; basicosta yellow orange to orange brown; 
subcostal sclerite with golden pubescence; costal sections 2 to 
6 in the proportion 56:31:73 :27:8; lower squama lightly yellow- 
ish to yellowish brown. 
Abdomen brilliant shining metallic blue green, with thin sil- 
very pollen on venter; first segment black on dorsum; second 
segment with a purplish or black middorsal spot on anterior 
margin, the hind margin purplish or black, and with recumbent 
marginal bristles; third seginent often with hind margin nar- 
rowly purplish or black and with a marginal row of erect bris- 
tles; basal sternites usually with considerable fine tawny-colored 
hair; fifth sternite brownish, divided, the arms rounded apically. 
Genital segments brownish, metallic dorsally, internal anatomi- 
eal structures (pl. 24, D and E) as illustrated. 
Female. Head height 10.9; length of head at antenna 5.1 and 
at vibrissa 5.4; parafaciale 1.3 in width opposite lunule, vibrissae 
set 2.1 apart; head width 12.3; eye height 7.8; bucca 0.21 of eye 
height; front at narrowest (about 1.0 above lunule) 0.28 of 
head width, 0.29 at vertex and 0.34 at antennal base; frontale 
one-half frontal width at ocellar triangle and narrowing an- 
teriorly, black at vertex, orange to orange brown at lunule; 
frontal row of bristles only very slightly diverging anteriorly 
as they follow the frontale, each row consisting of eight or 
nine bristles; outer vertical bristle 0.65 as long as inner and 
divaricate; frontoorbital bristles two proclinate and one reclinate, 
the foremost proclinate bristle usually considerably larger than 
the following bristle; ocellar bristles almost exactly divaricate 
and with a lesser pair of ocellar bristles immediately behind and 
between posterior ocelli, these also nearly divaricate. Otherwise 
similar to male except for normal sexual differences. 
