376 DIPTERA 
Geographical distribution. 
1. M. armata, Cresson, Ent. News Philad. Vol. 26, p. 455, f. 3 (1915). W. United States. 
2. M. armifes, Cresson, ibidem, Vol. 26, p. 454, f. 5, 6 (1915). New Mexico. 
3. M. atra, Cresson, Ent. News Philad. Vol. 26, p. 456 (1915). New Mexico. 
4- M. californica, Greene, Proc. Ent. Soc. Wash. Vol. 26, p. 61 (1924). California, 
5. M. flavibes, Cresson, Ent. News Philad. Vol. 26. p. 452, f. 1, 2(1915). — W. United States, 
6. M. hyaliuipenuis, Brethes, Revista Chilena. Hist. Nat. Vol. 23, p. 4o0[1920] Chile. 
(Heterhybos). 
7. M. minuta, Greene. Proc. Ent. Soc. Wash. Vol. 26, p. 62 (1924). New Mexico. 
8. M. piclibes, Coquillett, Proc. U. S. Nat. Mus. Vol. 25, p. 103 (1902); S. W. United States. 
Cresson, Ent. News Philad. Vol. 26, p. 453 (1915). t 
. M. Rileyi, Coquillett, Ent. News Philad. Vol. 4, p. 209(1893); Melander, S. W. United States. 
Trans, Amer. Ent. Soc. Vol. 28, p. 338 (1902); Cresson, Ent. News 
Vol. 26, p. 454 (1915). 
- scutellata, Coquillett, Proc. U. S. Nat. Mus. Vol. 25, p. 102 (1902); WW. United Síates. 
Cresson, Ent. News Philad. Vol. 26, p. 451, f. 4 (1915). 
. libialis, Coquillett, Proc. U. S. Nat. Mus. Vol. 18, p. 409 (1896); "W. United States. 
Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 338 (1902); Cresson, 
Ent News Philad. Vol. 26, p. 453 (1915). 
S 
'10. 
g 
II. 
5. GENus PRORATES, MELANDER 
Prorates, Melander, Ent. News Philad. Vol. 17, p. 372 (1906); Williston's Man. N. Amer. Dipt. 
p. 224 (1908); Kertész, Cat. Dipt. Vol, 6, p. 3 (1909); Coquillett, Proc. U. S. Nat. Mus, Vol. 37, 
p- 595 (1910). 
Characters. — Small opaque gray bristleless species, somewhat resembling a Therevid, stigma 
strong, third and fourth veins both forked, alula well developed, legs simple, third antennal joint with a 
microscopic style. Head globose, broader than long, occiput concave, the face extremely short and 
retracted, eyes of the male contiguous from the antennz to the vertex, the facets of the upper two-thirds - 
enlarged, of the female broadly separated on the front, the facets uniform, front of the female with 
parallel sides, no ocellar bristles; eyes reduced in back beneath, the lower part of the head made up of - 
the occiput, mouth opening large, with rounding edges; proboscis rigid, porrect, slightly shorter than 
the head. palpi retracted; antennz three-jointed, the basal joints similar and small, the third joint 
compressed, conical, tipped with a microscopic bristle, Thorax but little convex, nearly bare, bristles 
very weak, one notopleural, one postalar and one pair of scutellars present, mesopleurz bearing weak 
hairs. Abdomen cylindrical, scarcely tapering in either sex, pygidium terminal, not enlarging the 
abdomen, entirely included within a pair of lateral valves, no ovipositor. Legs slender, simple, 
nowhere thickened, devoid of all bristles, the hairy covering very short, pulvilli minute. Wings rather 
broad, anal angle rectangular, no basal bristle, costal hairs microscopically small, costa continuing to the 
posterior branch of the third vein, auxiliary vein distinct from the first and gently curving forward at its 
end to meet the costa, a distinct elliptical stigma surrounding the end of the first vein which is not far 
beyond the middle of the wing, second vein rather short, ending nearer the first than to the tip of the 
wing, pedicel of the second and third veins arising over the middle of the second basal cell, anterior 
crossvein at the middle of the discal cell, the first basal therefore longer than the second, discal 
cell pointed apically, the posterior crossvein nearly parallel with the hind margin of the wing, petiole of 
the second posterior cell very short, none of the posterior veins attaining the hind margin, anal cell 
larger than usual, its outer angle acute. anal vein reaching the hind margin, alula well developed in 
both sexes but not margined, calypteres large for an Empid, membranous and with a thickened fringed 
margin 
