576 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



and postacrostichals; short erect decussate apical scutellar pair. 

 Third vein bristled only at base, othei-s bare. Apical cell open well 

 before tip. Hind crossvein nearer to cubitus. Male claws long. 

 No median marginals on first two segments; median row on last 

 two. Hind tibiae ciliate, with a longer bristle. 



TOPOMEIGENIA MATUTINA, new species. 



Length, 8.5 mm. Two males, Topolobampo Bay, Sinaloa, Mexico, 

 September 14, 1909, in company of numerous specimens buzzing 

 loudly amongst fohage of shrubs near edge of bay before 6 o'clock 

 in the morning (C. H. T. Townsend). 



Antennae blackish, second joint tinged with rufous. Palpi fulvus. 

 Frontaha brown. Rest of head dull silvery. Thorax and scutellum 

 thickly dull silvery, more or less famtly brassy; with five blackish 

 vittae, the middle one restricted to postscutum. Abdomen mostly 

 rufous; basal half or more of last three segments pale brassy poUi- 

 nose, the pollen thmning irregularly posteriorly on each segment; 

 a dark median vitta present. Legs dark brown. Wmgs clear. 

 Tegulae nearly white. 



Type— Cat. No. 22259, U.S.N.M. 



PARAMEIGENIA, new genus. 



Genotype. — Paradexodes alhifacies Townsend 1908.^ 

 Differs from Paradexodes as follows : Onl}^ two frontals below base 

 of antennae in both sexes. Clypeus not longer than one and one- 

 half times its width. No apical scutellar pair. Only two strong 

 postacrostichals. Third antennal joint onl}^ twice second in both 

 sexes. Arista thickened only at extreme base. Thorax no wider 

 than abdomen. 



OLLACHEA, new genus. 



Genotype. — OUachea elongata, new species. 



Head characters of Spylosia, but epistoma warped. Parafacialia 

 hairy on upper half. Cheeks nearly half eye length in female; less 

 in male. Arista bare. Third antennal joint about twice the elon- 

 gate second. Eyes bare. Ocellars present. Proboscis short; palpi 

 clubbed. Three sternopleurals, postintraalers, preacrostichals, post- 

 acrostichals, and lateral scutellars; three or four postsuturals ; only 

 apical scutellar hairs; Third vein bristled only at base; others bare. 

 Apical cell open a little before tip. Hind crossvein nearer to cubitus. 

 Abdomen long, narrow, tapering to tip, flattened. Median marginal 

 pair on first two segments; marginal row on last two; median discals 

 on all segments but those of first and last segments vestigial in 

 female; the median discals are doubled on intermediate segments 



• Tax. Muse. Flies, p. 102. 



