SUBFAMILY MESEMBRINELLINAE 71 
hair, the latter with fine long black hairs ventrally; scutellum 
concolorous with dorsum, the under surface with yellow pile; 
lateral bristles two large and two weak; postscutellar plates with 
jong tawny hair. 
Legs with femora orange, tibiae and tarsi dark orange brown; 
middle tibia with two posterior bristles, one near basal third 
and one near apical third, and one posterodorsal bristle near 
apical third; hind tibia with two anterodorsal bristles, one near 
basal fourth and one near middle. 
Wing (pl. 8, B) hyaline, slightly tinged with orange brown, 
especially along the costal margin and basally; basicosta orange; 
subcostal sclerite orange, with orange pubescence; costal sections 
2 to 6 in the proportions 100:84 :123 :66:16; third vein with only 
one or two basal setulae; upper squamal lobe hyaline, orange 
brown apically; lower squamal lobe orange brown. 
Abdomen with first segment yellowish to orange, the posterior 
margin purplish; second segment purple over orange ground 
color; third and fourth segments shining purple over brown, 
the third with a marginal row of strong, erect bristles, the fourth 
with a marginal row of rather weak bristles; abdomen usually 
more orange ventrally than dorsally; fifth sternite (pl. 11, B), 
as illustrated. 
Genital segments large; first segment dark metallic, with black 
setae; second segment orange, with black setae. Internal ana- 
tomical details (pl. 11, A, B, and C), as illustrated. 
Female. Head width 16.3; length at antenna 7.7, and at 
vibrissa 7.5; eye height 11.0; head height 12.8; bueca 0.12 of 
eye height; frontale 0.60 of frontal width at lunule, wider pos- 
teriorly; proclinate frontoorbital bristles two or three; frontal 
row of bristles consisting of five large and three or four small 
bristles, the rows not divergent anteriorly, extending to the base 
of the second antennal segment; front with nearly parallel 
margins from vertex to within 1.5 units of the lunule, 0.27 of 
head width at vertex, 0.30 at antennal base, with a few pale 
hairs outside the frontal rows; parafaciale 1.7 in width opposite 
lunule; vibrissae set 4.0 apart; palpus 4.6 in length; third. anten- 
nal segment 2.5 times as long as second. Wing with costal 
sections 2 to 6 in the proportions 100:95:140:70:19. Otherwise 
similar to male except for normal sexual differences. 
There is considerable variation in the number of bristles in 
certain series in this species. The acrostichal series may have 
two or three bristles anterior to the suture, and two, three or four 
posterior to the suture. There may be either two or three sterno- 
pleural bristles, usually three. A first impression of a long 
