FAM. EMPIDID/E 375 
.3. GeNUs MALTHACOTRICHA, BECKER 
Heterotropus, Loew, Beschr. Eur. Dipt. Vol. 3, p. 180 (1873). 
Malthacotricha, Becker, Ann, Mus. Zool. Acad. Sc. St. Pétersb. Vol. 12, p. 312. pl. 2, f. 18 (1907); 
Kertész, Cat. Dipt. Vol. 6, p. 14 (1909); Becker. Ann. Mus. Zool. Acad. Sc. St. Pétersb. 1912, 
Vol. 17, p. 482 (1913). 
Characters. — Becker, in 1907, described Malthacotricha glauca as a new genus of Empidide, 
locating it in the Hybotinz because of the lengthened anal cell and the horizontal proboscis, even though 
the insect has the third vein forked and the discal cell emitting three posterior veins. Later, in 1913, 
Becker assigned his genus to the Bombyliidze as synonymous with the older Heterotropus Loew. The 
genus occurs in Central and Western Asia, with two known species. Apparently it is closely related to 
the American Prorates Melander, which see on the following page. 
Geographical distribution of the species of /Te/erotropus. 
I. H. albidipennis, Loew, Beschr. Eur. Dipt. Vol. 3, p. 180 (1873); Becker.  Transcaspia. 
Ann. Mus. Zool. Acad. Sc. St. Pétersb. Vol. 17, p. 586 (1913). 
2. H. glaucus, Becker, ibidem. Vol. 12, p. 313, pl. 2, f. 13 [1907] (MallZaco- Turkestan. 
tricha) ; ibidem, Vol. 17, p.482, f. 25 (1913). 
.4. GENUS MYTHICOMYI!A, COQUILLETT 
Mythicomyia, Coquillett, Ent. News Philad. Vol. 4, p. 209 (1893); Proc. U. S. Nat. Mus. Vol. 18, 
p. 409 (1896); Melander, Trans. Amer. Ent. Soc. Vol. 28, p. 337 (1902); Coquillett, Proc. Ent. 
Soc. Wash. Vol. 5, p. 253 (1903); Williston, Man. N. Amer. Dipt. p. 211, 218 (1908); Kertész, 
Cat. Dipt. Vol. 3, p. 333 (1908); Coquillett, Proc. U. S. Nat. Mus. Vol. 37, p. 573 (1910); Cresson, 
Ent. News Philad. Vol. 26, p. 448-456 (1915); Greene, Proc. Ent. Soc. Wash. Vol. 26. p. 60-64 
(1924). 
Heterhybos, Brethes, Revista Chilena Hist. Nat. Vol. 23, p. 49 (1919). 
Characters. — Coquillett erected the genus My/Ahicomyia in 1893, placing it in the Empididz. 
Since that time the group has been shifted here and there by various writers. Aldrich and Kertész, 
in their respective catalogs. placed it in the Leptidz, the writer in 1902, then unacquainted with 
specimens, left it in the Empididz but segregated it in a subfamily, the M ythicomyiinz, Cresson 
located it in the Empididz, and Williston and Greene probably in the Bombyliidz. 
Mythicomyia is represented by eight described species, restricted to the Western United States, 
where the minute flies are found hovering over bush-flowers, such as ocean spray. In addition, 
Heterhybos hyalinibennis Brethes was described as a new genus of Empididz from Rio Blanco. South 
America. This genus is completely synonymous with Mythicomyia. These species are closely related 
to the European Glabellula Bezzi, 1902, redescribed by Greene, 1924, as Pachyneres, and. belong to the 
subfamily Cyrtosiinze of the Bombyliidz, as defined by Becker, Ann. Mus. Zool. Acad. Sc. St. Pétersb. 
Vol. 17, p. 472 (1913). Glabellula has the second basal cell fused with the discal cell and the femora more 
or less enlarged. In MytAicomyia the discal cell is complete, the two basals weakly separated and the 
femora. are slender. 
Tyne species : M. Rileyi, Coquillett, the original species. 
