DIPTERA 791 



EE. Palpi well-developed; "front" and face bristly; anal vein pro- 

 duced to the wing-margin. Seashore flies, p. 855. . . PHYCODROMiDiE 

 CC. Oral vibrissas not differentiated from the peristomal hairs. 



D. Legs very long and stilt-like; tibis usually without preapical bristle; 

 cell Rj constricted at the wing-margin. 



E. Proboscis greatly elongate and folding near its middle; arista 

 terminal; ovipositor very long (Stylogaster) p. 853. . .CoNOPiDiE* 

 EE. Proboscis short ; arista dorsal ; ovipositor not lengthened. 



F. Buccas and posterior orbits narrow, p. 858 .... Tanypezid^ 



FF. Buccse broad, p. 858 Micropezid^ 



DD. Legs not long and stilt-like. 



E. Preapical tibial bristles present; "ovipositor" membranous and re- 

 tractile. 

 F. Postvertical bristles well -developed and converging. 



G. Anal vein produced to the wing margin; last tarsal segment 



enlarged and flat. p. 855 Phycodromid^ 



GG. Anal vein not produced to the wing margin; last tarsal 



segment normal, p. 856 Sapromyzid^ 



FF. Postvertical bristles parallel or diverging, rarely lacking, p. 855. 



Sciomyzid^ 



EE. Preapical tibial bristles absent, if present in exceptional cases, the 



ovipositor horny and not wholly retractible, or the cell ist A of the 



wing drawn out into a lobe, or vein Ri bristly above. 



F. Ovipositor membranous, retractile; vein Ri bare above; cell ist 



A without acute process or lobe. 



G. Palpi well-developed; postvertical bristles converging or 



wanting, p. 862 Ochthiphilid^ 



GG. Palpi vestigial; postvertical bristles divergent; the "front" 



not bristly except at the vertex, p. 858 Sepsid^ 



FF. Ovipositor horny, not wholly retractible; postvertical bristles 

 not converging; palpi present. 



G. The costal break or scar is located just proximad of the tip of 

 vein Sc; cell M and the cell ist A small, the latter with rounded 



apex; only one fronto-orbital bristle, p. 856 Lonch^id^ 



GG. Costa either unbroken or if broken there is also a trace of a 

 break basally, indicated by a dark or light scar or constriction; 

 cell M and cell ist A large, the latter in many cases with a sharp 

 angle or prolonged into a lobe; or the costa with a strongly 

 marked stigma due to an abrupt double ctirve in vein Ri near its 

 tip and the second tergite of the abdomen with at least one long 



bristle on each side. p. 856 Ortalid^ 



BB. Subcosta absent, or vestigial, or running very close to vein Ri and ending 

 with it in the costa before the middle of the wing, or evanescent at the tip. 

 C. Head produced on each side into a lateral process bearing the eye. p. 859. 



DlOPSID^ 



CC. The eyes not stalked. 



D. First segment of hind tarsi swollen and in most cases shorter than the 



second segment; oral vibrissas present, p. 855 Borborid^e 



DD. First segment of hind tarsi normal. 



E. Subcosta] vein evanescent at the tip, where it ttu-ns sharply forward 

 at some distance before the tip of vein Ri ; wings nearly always pic- 

 tured; cell 1st A angular or drawn out into an acute lobe; no pre- 

 apical tibial bristle, p. 856 Trypetid^ 



EE. The subcosta runs very close to Ri or is fused with it either wholly 

 or in part but only in a few cases suddenly interrupted at the tip, in 

 which case the wing with a fold extending across from the costal 

 fracture to the tip of cell M, 

 F. Cell 1st A wanting. 



*See Table A for distinctive characters of those Conopidas in which the free 

 part of vein Cua does not appear like a cross- vine. 



