134 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 5 1 



T. plumipes (J. C. Fabricius) Wiedemann is probably a Polis- 

 tomyia, as indicated by the yellow scutellum, broad, clear inner mar- 

 gin of wings, and the cylindrical abdomen. The latter is described 

 as black, which would indicate a form without fasciae or pollinose 

 markings, since it is hardly possible that such could have been so far 

 lost as to leave no trace. We thus have the following forms of this 

 genus, to be separated as below : 



Polistomyia plumipes — No pollinose fasciae on abdomen. Continuous 



black surface. 

 histrio — Two pollinose fasciae, interrupted. 

 trifasciata — Tbree fasciae, broadly interrupted. 

 subdivisa — Four fasciae, two broadly interrupted and two 



faintly so. 

 umbra — Continuous pollinose surface, interrupted by median 



vitta. 

 indivisa — Continuous pollinose surface. 



EUTRICHOPODA, gen. nov. 



Differs from Trichopoda in the apical cell being moderately long 

 petiolate, and the wings with inner border broadly hyaline, the latter 

 being nearly or about one-third of wing breadth. Hind tibiae cil- 

 iate, hind femora without cilia. Abdomen cylindrical in female, 

 probably flattened in male. Tegulse pale or whitish yellow. Type, 

 the following species : 



Eutrichopoda nigra, sp. nov. 



Syn. Trich. lanipcs van dEr Wulp (non J. C. Fabricius, Wiedemann), 

 Biol. C. A. Dipt, ii, pp. 434-5. 



One female, Tehuantepec, Sumichrast. 



Length, 9 mm. ; of wing, 8 mm. Black. Parafrontals silvery 

 white, with only a faint tinge of golden, which tinge is lost in view 

 from above and behind. Face wholly silvery white, including para- 

 facials. Transverse suture of mesoscutum marked by a golden yel- 

 low linear fascia, with two golden lines running to front border of 

 thorax, humeri broadly golden. Scutellum is of the same dull black 

 as the abdomen, with hardly a brownish tinge. Tegulae saturated 

 with a faint yellow tinge. Femora almost as black as rest of legs, 

 with a faint brownish tinge. The mesoscutum behind suture is 

 faintly purplish or bluish shining. The wings have no yellowish 

 tinge in the black, and the inner hyaline border is hardly one-half as 

 wide as the black portion. 



Type.— Cat. No. 10,882, U. S. N. M. 



