yUES 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 coxse, clothed with 

 minute black bristles ; all the coxse 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 tibiae also slightly flattened 

 and widened on the apical half ; middle tibise with 

 a long spur inside at the tip, and hind tibise with a 

 small one inside and a very minute one outside ; tarsi 

 longer than the tibiae, 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 vain, channelled frons, small size, and by 

 the absence of bristles on the tibise. 



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 ; venulae undu- 

 latse ; costa ad basin subciliata. 



Distinguished from all the existing genera of Pho- 

 ridse by its flat and broad shape, which resembles 

 that of the small species of Sphmrocera. 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^ 



