DIPT ERA 



291 



K. With tibial spurs, p. 300 Mycetophilidje 



KK. Without tibial spurs, p. 301 Cecidomyid^e 



II. Ocelli absent. 



J. Antennae short, segments wider than long; wings very broad. 



P- 303 9 SlMULIID^E 



JJ. Antenna? either with narrow segments or bushy with dense 

 coat of hairs; wings narrow or moderately broad. 

 K. Media forked and cross-vein m-cu present, p. 295. 



Dixid.e 



KK. Media not forked when m-cu cross-vein is present. 



(Inclusive of Thaumalea) p. 296 Chironomid,e 



BB. Antennas consisting of not more than four segments, in some cases the last 

 segment is again divided into several closely fused subsegments; palpi with 

 not more than two segments; if the antenna; have numerous segments in 

 exceptional cases, the empodium is developed pulvilliform (Fig. 498). 

 C. Empodium developed pulvilliform, that is, three rounded pads under the 

 tarsal claws. 

 D. Third antennal segment consisting of several subsegments or antennae 

 consisting of more than three segments. 

 E. Branches of the radius crowded together near the costal margin in most 

 cases (Fig. 536), tibiae without spurs, costal vein discontinued at or 



before the apex of the wing. p. 307 Stratiomyid^e 



EE. Venation not of this type. 



F. Alulets large; venation as in figure 532 Tabanid^e 



FF. Alulets small or vestigial. Coenomyid<e, Xylomyhxe, and Xylopha- 



GID/E. 



DD. Third antennal segment simple. 



E. Alulets very large; head very small, p. 308. . . . (Cyrtid^e) Acrocerid/E 

 EE. Alulets small. 



F. Costa extends around the apex of the wing. p. 307 .... Rhagionid^e 

 FF. Costa ends at the apex of the wing; venation intricate. 



Nemestrinidce 



CC. Empodium absent or in the form of a thread, that is, only two pads under 

 the tarsal claws. 

 D. Antennae consisting apparently of a single globular segment with arista; 

 anterior veins of the wing stout, posterior veins weak. (Fig. 554). p. 313. 



Phorid^e 



DD. Antennas with but few exceptions with three easily distinguished seg- 

 ments. 

 E. Cells M and 1st M 2 not separated (Fig. 550). 



F. Frontal suture absent; vein R with a knot-shaped swelling near the 

 forking of the radial sector; the r-m cross- vein near this swelling 

 when present; flies in most cases metallic in coloring, p. 310. 



Dolichopodim: 



FF. Frontal suture present; vein R with or without this swelling; the 

 cross vein more remote from the base of the wing in most cases. 

 Acalyptratas such as some Drosophilid^e, p. 318, Agromyzid^e, p. 318, 



EPHYDRIDvE, p. 317, CHLOROPID.E, p. 317, BORBORID/E. 



EE. Cells M (or 2d M) and 1st M 2 separate. 

 F. Radial sector three branched. 



G. Vertex of the head distinctly hollowed out between the eyes; eyes 

 never contiguous. Large species in most cases. 

 H. Proboscis with fleshy labella at tip; venation complicated (Fig. 



549)- P- 310 Mydaid^e 



HH. Proboscis horny and rigid, without labella at tip. p. 309. 



ASILID.E 



GG. Vertex not hollowed out between the eyes. 

 H. Cell M 3 present. 



I. Vein R 5 ending before the apex of the wing Apiocerida 



II. Vein R 5 not ending before the apex of the wing. p. 309. 



■ • • Therevid^e 



H. Cell M 3 obliterated by the coalescence of veins M 3 and Cui. 

 I. Third segment of the antennas without a style or an arista; 

 vein Mi ending at or before the tip of the wing. p. 309. 

 Scenopinid^e 



