12 ^^ 7DIPTERA 
2. Third joint of the antenne lengthened and passing inseusibly into the 
style; second. vein. apically bent. to. meet the costa. Perpendicularly ; e ; à 
thorax strongly arched ; eyes contiguous (Pl. 5, Fig. 41) . . Genus Howarocsewis, Philippi. 
T hird joint of the antenna short and. conical, ending in a thin arista ; : 
second vein rounding iuto the costa; thorax rather flattened. above ; 
eyes. separated, marrowly ou the face and broadly om the front 
(Genus Baacuysroma, Meigen). . . . . . (| €. ac. m DN T E 3. 
3. First submarginal cell open; abdomen of Q typically e in a E LEY 
bladder-like vescicle; cy legs not deformed (Pl. 1, Fig. 2). . Subgenus BRACHYSTOMA, S. Str. 
First submarginal cell closed ; abdomen Q not vesciculate; cy legs often 
deformed ; bygidium typically fringed (Pl. 8, Fig. 77). . . Subgenus BrEPHanorRocra, Loew. 
I. GENUS BRACHYSTOMA, MEIGEN 
Brachystoma, Meigen, Syst. Beschr. Vol. 3, p. 12 (1822); Macquart, Hist. Nat. Dipt. Vol. 1, p. 344- 
(1834); Zetterstedt, Ins. Lapp. p. 557 (1838): Blanchard, Hist. Nat. Ins. Vol. 3, p. 582 (1840); 
Zetterstedt, Dipt. Sc. Vol. 1, p. 360 (1842); Boitard, Nouv. Man. Vol. 3, p. 321 (1843); Rondani, 
Dipt. Ital. Prodr. Vol. 1, p. 15o [1856] (Brachistoma); Bigot, Ann. Soc. Ent. France (3), Vol. 5, 
P- 562 (1857); Schiner, Fauna Austr. Dipt. Vol. r. p. 117 (1862); Lioy, Atti Inst. Venezia 1864, 
p.603 (1864); Bigot, Ann. Soc. Ent. France (6), Vol. 9. p. 121 (1889); Coquillett, Proc. U. S. 
Nat. Mus. Vol. 18, p. 389 (1895); Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 259 (1902); 
Coquillett, Proc. Ent. Soc. Wash. Vol. 5, p. 247, 262, 263 (1903); Melander, Williston's 3d. 
Man. p. 224 (1908); Kertész, Cat. Dipt. Vol. 6, p. 1 (1909); Bezzi, Nova Acta Akad. Naturf. Halle, — 
Vol. 9t, p. 3ot (1909); Coquillett, Proc. U. S. Nat. Mus. Vol. 37, p. 516 (1910). 
Biepharoprocta, Loew, Berl. Ent. Zeitschr. Vol. 6, p. 194 (1862); Coquillett, Proc. U. S. Nat. 
Mus. Vol. 28, p. 389 (1895); Williston, Manual, p. 74 (1896) (Blepharoproctus); Melander, Trans. . 
Amer. Ent. Soc. Vol. 28, p. 261 (1902); Coquillett, Proc. Ent. Soc. Wash. Vol. 5, p. 246, 263 
(1903); Melander, Williston's 3d. Man. p. 224 (1998); Kertész, Cat. Dipt. Vol. 6, p. 2 (1999); . 
Bezzi, Nova Acta Akad. Naturf. Halle, Vol. 91, p. 3ot (1909); ogni Prod U. s. Nat. 
Mus. Vol. 37, p. 514 (1910). 
Heterophlebus, Philippi, Verh. Zoo.-bot. Ges. Wien, Vol. 15, p. 764 (1865). 
Characters. — No ocellar prominence, the vertex rounding into the occiput ; eyes subcontiguous 
on the face, distinctly separated above the antenne, the sides of the front parallel to the ocelli; basal 
joints of the antenne together longer than the third which is conical and shorter than the slender termi- 
nal arista ; proboscis thick, inflexed, palpi small and broad. Thorax short, rather flattened above, the 
scutellum small, legs close together, no pubescence nor bristles beyond a few microscopic prescutellar 
dorsocentral hairs and single supraalar and postalar bristles, scutellum with two or more hairs; pleure 
bare but pollinose. Seventh tergite of the female abdomen typically inflated to a large translucent 
bladder, open apically as a vertical slit, the seventh sternite closing the vescicle below, but in Blepharo- 
frocta this segment is compressed and not larger than the preceding and has a more strongly ciliated 
opening; pygidium small, retracted or exposed, with central filament and two pairs of small narrow 
lateral valves, sometimes enclosed in a projecting ventral fringe. Legs elongate, slender, femora usually 
with some sete beneath, tibia» and tarsi of males of Blefpharoprocta sometimes greatly deformed. Wings 
with reduced anal angle, third vein forked, basal cell& bos four F poNMN cells, anal cell long and 
acute, no basal bristle on the costa. 
