FLIES PARASITIC ON ANTS. 433 
two long bristles ; halteres dirty pale yellow ; abdomen 
bare, dull black, with slightly yellowish incisures ; ovi- 
positor polished black, long, slightly incurved and 
grooved. 
Legs pale yellow, including the coxe, clothed with 
minute black bristles; all the cox# with two or three 
black bristles at the tips, the legs otherwise bare except- 
ing the spurs; femora flattened and widened, especial- 
ly the hind pair, the hind tibie also slightly flattened 
and widened on the apical half; middle tibie with 
a long spur inside at the tip, and hind tibie with a 
small one inside and a very minute one outside; tarsi 
longer than the tibiz, joints gradually diminishing in 
length. 
Wings very slightly smoky, broad; second thick 
vein not extending half the length of the wing, thick- 
ened, but not forked at its tip; first veinlet with a 
steady curve ; second very slightly curved at base, other- 
wise straight; third very slightly undulated ; fourth 
hardly visible at base, evident towards tip, very slightly 
undulated ; costa bristly up to end of second thick 
vein. 
This species is readily distinguished by its simple 
second thick vein, channelled frons, small size, and by 
the absence of bristles on the tibia. 
It is parasitic on Lasius niger. 
PLATYPHORA, n. gen. 
Lata, planx, tota absque setis. Frons latissima. 
Thorax transversus. Abdomen parvus. Alarum vena 
cubitalis simplex, subacostali parallela ; venule undu- 
late ; costa ad basin subciliata. 
Distinguished from all the existing genera of Pho- 
ride by its flat and broad shape, which resembles 
that of the small species of Sphewrocera. The ab- 
sence of strong bristles on the frons, thorax, and legs 
also distinguishes it from all the genera except Gym- 
nophora, which, however, is of the usual arched Pho- 
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