Dipt era. 69 



55. Thorax convex, face and cheeks not remarkably bristly 56 



Mesonotum and scutellum flattened; front, face and cheeks bristly; all the 



tibife spurred and with preapical bristles; last tarsal joint large. (CcElopa, 

 Omomyia.) PHYCODROMID^ 



56. Central strip of the front (frontalia) usually well differentiated from the sides 



(orbits) (PI. 13, fig. 304); first vein nearly half the wing-length; second 

 basal cell not minute; crossveins not close together; frontal cross-bristles 

 absent. (Cordylura, Parallelomma, Scatophaga) (PI. 12, fig. 271) {COR- 

 DYLURID.E, SCATOMYZIDJE, SCOPEUM ID.^) SCATOPUAGID^ ^ 

 Central strip of the front not differentiated from the sides; first vein about 

 one-third of the wing-length; second basal cell minute; crossveins sometimes 

 approximated; frontal cross-bristles sometimes present. (Cliisia, Hetero- 

 neOra.) HETERONEURIDiE ; 



57. First posterior cell closed or narrowed in the margin; abdomen elongate; legs 



long or very long 58 



First posterior cell widely open, if narrowed the abdomen is short and the legs 

 are not unusually long and slender 60 



58. Eyes large, the cheeks and posterior orbits narrow, occiput concave 59 



Head more or less globular, the cheeks broad and the face retreating; proboscis 



short. (Micropeza, Calobata, Nerius.) 



{CALOBATID.E) MICROPEZID^ O 



59. Proboscis short; arista dorsal; ovipositor not lengthened. (Tanypeza.) 



TANYPEZID^ y 

 Proboscis and ovipositor greatly lengthened; arista terminal (Stylogaster) 

 (see couplet 36) CONOPIDiE 



60. First posterior cell narrowed; femora and usually the hind tibise enlarged; all 



the tibijB with preapical bristle; scutellum usually prominent; basal cells 

 relatively large; tropical species. (Rhopalomera, Willistoniella.) ^ 



RHOPALOMERID^ 

 First posterior cell widely open, if rarely narrowed the femora are not thick . . 61 



61. Hind tibiae with a preapical bristle, apical tibial bristles present; ovipositor 



neither flat nor drawn out; usually two fronto-orbital bristles; wings some- 

 times pictured 62 



Hind tibia; without preapical bristle, middle tibiae alone with apical bristles; 

 front femora bristly beneath; ovipositor flattened and more or less pro- 

 jecting; postvertical bristles divergent when present; dypeus prominent; 

 wings usually pictured 64 



62. Postvertical bristles divergent when present; second antennal joint without 



a dorsal bristle; mesopleural and usually sternopleural bristles wanting; 

 front femora not bristly beneath; anal vein reaching the wing-margin. .63 

 Postvertical bristles convergent; second antennal joint with a dorsal bristle; 

 one or two sternopleural and a mesopleural bristle present; lower outer 

 edge of the front femora bearing bristles; anal vein obliterated toward the 

 tip. (Lauxania, Camptoprosopella.) . . (SAPROMYZID.E:) LAUXANIID^ p 



