II2 DIPTERA 
15. GENUS HILARA, MEIGEN 
Hilara, Meigen, Syst. Beschr. Vol. 3, p. 1 (1822); Curtis, Brit. Ent. Vol. 8, p. 13o (1826); Macquart, 
Dipt. N. France, Vol. 3, p. 108 (1827); Hist. Nat. Dipt. Vol. r, p. 340 (1834); Zetterstedt, Fauna 
Ins. Lappon, p. 554 (1838); Westwood, Gen. Syn. p. 132 (1840); Zetterstedt, Dipt. Scand. 
Vol. zr, p. 335 (1842); Boitard, Man. Ent. Vol. 3, p. 320 (1843); Walker, Ins. Brit. Dipt. Vol. 1, 
P. 97 (1851); Rondani, Dipt. Ital. Vol. r, p. 151 [1856] (Hylara); Bigot, Ann. Soc. Ent. 
France (3), Vol. 5, p. 562 (1857); Schiner, Fauna Dipt. Austr. Vol. r, p. 112 (1862); Lioy, Atti 
Inst. Sc. Veneto, Venezia, 1864, p. 60r (1864); Beling, Arch. Naturg. Berlin, Vol. 48, p. 240 
(1882); Bigot, Ann. Soc. Ent. France (6), Vol. 9, p. 117 (1889); Strobl, Verh. Zool.-bot. Ges. 
Wien. Vol. 42, p. 85, 182 (1892); Becker, Wien. Ent. Zeit. Vol. 13, p. 156, 159 (1894); Coquil- 
lett, Proc. U. S. Nat. Mus. Vol. 18, p. 389, 394 (1895); Williston, Man. N. Amer. Dipt. p. 75 
(1896); Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 262 (1902); Coquillett, Proc. Ent. Soc. 
Wash. Vol. 5, p. 250, 263 (1903); Bezzi, Ann. Mus. Hungar. Vol. 2, p. 320, 341, note (1904); 
Melander, Williston, N. Amer. Dipt. Man. p. 226 (1908); Bezzi, Nova Acta Akad. Naturf. Halle, 
Vol. 9t, p. 3o2, 375 (1909); Kertész, Cat. Dipt. Vol. 6, p. 84 (1909); Coquillett, Proc. U. S. 
Nat. Mus. Vol. 37, p. 552 (1910); Grünberg, Süsswasserf. Deutschl. 2a, Vol. 1, p. 154 (1910); 
Lundbeck, Dipt. Dan. Vol. 3, p. 140 (1910); Wahlgren, Ent. Tidskr. Vol. 3r, p. 44, 65 (1910); 
White, Proc. Roy. Soc. Tasmania, 1916, p. 220 (1917); Brunetti, Fauna Brit. Ind. Dipt. Vol. 1, 
p. 357 (1920). , 
Characters. — Medium-sized species, usually black or blackish in color although sometimes 
yellowish, distinguished by the anterior bend at the end of the auxiliary vein and by the almost univer- 
sally enlarged front metatarsi of the male. 4A genus rich in species and hence presenting a wide range 
in the variability of characters, particularly of the chzetotaxy and the secondary sexual devices. Head 
globular, eyes separated in both sexes, except in a few species where the males are holoptic and have 
the upper facets enlarged, otherwise the facets are uniform ; front and face each quadrate, fronto-orbital 
bristles usually prominent, cheeks linear; antenne inserted at the middle of the head, distinctly three- 
jointed, as long as the head, the basal joints short and with few setule, the first joint cylindrical, the 
second globular, the third compressed, conical, ending in a lengthened three-jointed style, whose basal 
segment is minute and quadrate and whose apical part is a short bristle; proboscis as long as the head 
or somewhat shorter, vertical, the labrum sharp, chitinized, a little incurved, the labium shorter and 
with prominent labellar lobes, palpi porrect, up-curved and hairy ; occiput more or less hairy, ocelli not 
elevated, distant, the ocellar bristles separated, thorax rather robust, wider than the head, the meta- 
thorax short and declivous, bristles usually reduced, the rows of discal bristles usually replaced by hairs, 
pronotum often with a lateral bristle, notopleural bristles evident but variable; pleurz pollinose, meta- 
pleurze not setose. Abdomen more or less cylindrical, the seventh and eighth segments of the male 
usually small to accomodate the reflexed epipygium; abdomen of the female tapering, ending in two 
thin styles; epipygium usually compressed, the ventral keel ending in a curved tapering process, the 
lateral valves extending forward, variously fissate and spiny at the anterior end, dorsal valves and penis 
hidden. Legs not lengthened, rather hairy, usually with variable bristles on the tibiz, femora rarely 
thick, front metatarsi of the male almost always greatly swollen and often cristate with long hairs, 
pulvilli of moderate size, empodium distinct. Analangle rather prominent but rounded, costa continu- 
ing around the entire margin, stigma formed, auxiliary vein complete and distinct, curving forward 
at the end to enter the costa, third vein with a long fork, basal cells coextensive, discal cell as long as 
