18 DIPTERA 
Il. GeNus HYBOS, MEIGEN 
Hybos, Meigen, Illiger's Mag. Ins. Vol. 2, p. 269 (1803); Syst. Beschr. Vol.2, p. 261 (1820); Macquart, 
Mem..Soc. Sc. Lille, 1823, p. 143 (1823); Dipt. N. France, Vol. 3, p. 147 (1827); Hist. Nat. Dipt. 
Vol. r, p. 318 (1834); Curtis, Brit. Ent. Vol. 8, p. 661 (1837); Zetterstedt, Fauna Ins. Lappon, 
p. 535 (1838); Westwood, Gen. Syn. p. 133(1840); Zetterstedt, Dipt. Scand. Vol. 1, p. 233 (1842); 
Boitard, Man. Ent. Vol. 3, p. 316 (1843); Walker, Ins. Brit. Dipt. Vol. r, p. 120 (1851); Rondani, 
Dipt. Ital. Vol r, p. 153 (1856); Bigot, Ann. Soc, Ent. France (3), Vol.5, p. 559 (1857); Schiner, 
Fauna Austr. Dipt. Vol. r, p. 77 (1862); Lioy, Atti Inst. Venet. 1864, p. 719 (1864); Bigot, Ann. 
Soc. Ent. France (6), Vol. 9, p. 115 (1889); Coquillett, Proc. U. S. Nat. Mus. Vol. 18, p. 390 
(1895); Wheeler & Melander, Biol. Centr.-Amer. Dipt. Suppl. p. 372 (1901); Melander, Trans. 
Amer. Ent. Soc. Vol. 28, p. 245 (1902); Coquillett, Proc. Ent. Soc. Wash. Vol. 5, p. 251, 259 
(1903); Bezzi, Ann. Mus. Hungar. Vol. 2, p. 324 (1904); Vol. 3, p. 425 (1905); Melander, 
Williston's Man. N. Amer. Dipt. 3 ed. p. 224 (1908); Bezzi, Nova Acta Akad. Naturf. Halle, 
Vol. 91, p. 3or, 305 (19099); Coquillett, Proc. U. S. Nat. Mus. Vol. 37, p. 553 (1910); Lundbeck, 
Dipt. Danica, Vol. 3, p. 8 (1910); Wahlgren, Ent. Tidskr. Vol. 31, p. 42, 46 (1910); Brunetti, — 
Fauna Brit. Ind. Dipt. Vol. r, p. 336 (1920). 
Acromyia, Bonelli, in Latreille (not Leach, Lioy or Coquillett), Gen. Crust. Ins. Vol. 4, p. 305 (1809); 
Bezzi, Ann. Mus. Hungar. Vol. 2, p. 329 (1904). 
Noeza, Meigen, Nouv. Classif. Mouches, p. 27 (1800); Hendel, Verh. Zool.-bot. Gez. Wien, Vol. 58, 
p. 56 (1908); Kertesz, Cat. Dipt. Vol. 6, p. 3 (1909); Bezzi, Ann. Mus. Hungar. Vol. 1o, p. 453 
(1912); Coquillett, Proc. U. S. Nat. Mus. Vol. 37, p. 576 (1910). 
Characters. — Black-colored species measuring four to five millimeters, with downward curved 
abdomen, light pollinose coating and long, spinose hind femora. Head rather globular, the eyes large, 
meeting above the antennz up to the prominent ocellar triangle which is placed on the summit of the 
vertex, below the antennze the eyes are approximated but leave a distinct shortened face; no cheeks; 
proboscis slender, projecting forward as far as the length of the head, the palpi long and slender; antenne 
short, located below the middle of the head, the basal joints fused, the third joint oval and with a long 
slender terminal arista; no cephalic bristles. Thorax highly arched, less convex before the scutellum, 
prothorax quadrangular, appearing as a neck; rows of hair-like acrostichal and dorsocentral bristles, 
- humeri with hairs, two or three notopleural, two scutellar and one small postalar bristles present; pleurze 
pollinose but bare of hairs. Abdomen cylindrical, the pygidium more or less globose and large, 
asymmetrical, with dorsal and ventral convex distorted plates; eighth segment of the female normally 
retracted giving a blunt termination to the abdomen. Anterior legs hairy and bristly, especially in the 
male, hind legs elongate, the femora rather clavate and spinose beneath, hind tibize shorter than their 
femora, devoid of spurs, anterior tibize usually with apical bristles. "Wings with parallel margins, anal 
angle prominent and rectangular, veins strong, costal margin closely short-hairy, very rarely spinose, 
second vein ending near the tip of the wing, stigma weak, pedicel of the second and third veins arising 
beyond the middle of the second basal cell, third and fourth veins both curving backward, the first 
posterior ce!l not narrowed in the margin, discal cell narrow and long, complete, sending two simple 
posterior veins to the margin, basal cells long and equal, the anal crossvein forming an acute angle with 
the anal vein, no alula. Halteres most often light colored. 
Type species : H. grossipes Linnaeus. Meigen's first species was fwwebris, which is syno- 
nymous with grossifes. Curtis, in his British Entomology (1837), designated this as the type. 
