TABLE OF FAMILIES. 73 



Wings elongate, the cross-veins often approximated; post-vertical 

 bristles divergent; front bristly; smaller, somewhat elongate 

 flies - , sixth and first veins short. . Heteroneuridae, 318 



Front never bristly near the antennae; abdomen somewhat elon- 

 gate, cylindrical, usually narrowed near base. Small, black 

 flies about decaying matter Sepsidse, 269 



Costa almost always pectinate; tibiae with spurs and preapical 

 bristles; not very small flies. . . Helomyzidae, 324 



45. Femora thickened; hind tibiae usually dilated; basal cells not very 



small; first posterior cell narrowed; all the tibiae with preapical 

 bristle. Moderate sized, bare, southern flies. 



Rhopalomeridse, 280 

 Not such flies. ......... 46 



46. First posterior cell closed or narrowed in the margin; abdomen 



elongate; legs long or very long. ..... 47 



Not such flies. 48 



47. Eyes large, the cheeks and posterior orbits narrow, the occiput 



concave: 



Proboscis short; ovipositor not elongate. Tanypezidae, 264 

 Proboscis greatly elongate and folding near its middle; ovipos- 

 itor very long Conopidte, pt. 261 



Head subspherical, the cheeks broad and face retreating; probos- 

 cis short. . . . . . Micropezidae, 264 



48. One or two fronto-orbital bristles; preapical bristle absent or pres- 



ent; wings sometimes pictured; anal cell always rounded distally. 



Sapromyzidae, 288 



Upper fronto-orbital bristles, only, present; ovipositor horny, more 

 or less elongate; anal cell often acute distally, or drawn out 

 into a narrow, acute lobe; arista seldom plumose: no preapical 

 bristle (except Automola) ; wings almost invariably pictured. 



Ortalididee, 272 



Fronto-orbital bristles present* or absent; second joint of antennae 

 often elongated; postvertical bristles divergent; a preapical 

 bristle; ovipositor not horny; wings often pictured. Meadow 

 flies. Sciomyzidae, 321 



49. Head produced on each side into a lateral process for the eye; 



basal cell confluent with discal cell. . . Diopsidae, 314 

 Head not produced into lateral processes. .... 50 



* If small, greenish black flies of the sea-coast, with globular third 

 antennal joint, compare Canace (Ephydridae). 

 9 



