126 INSECUTOR INSClTliE MENSTRUUS 



talia narrower, hardly half as wide as one parafrontal. Two to 

 four recHnate orbitals. Parafacials wider below, scarcely nar- 

 rowed from the upper width. Four postsuturals. Hind scutel- 

 lar bristles not so long. No discals on second or anal segments, 

 only a short weak pair of discals on third segment. Piercer of 

 extraordinary length, reaching forward to middle coxae when 

 unsheathed. Larvipositor half as long as piercer. Tarsi stout, 

 no longer than tibiae. Hind femora with row of bristles on 

 lower outer edge, as well as on upper. Wings proportionately 

 shorter. Tegulse large. 

 Xiphomyia gladiatrix, new species. 



Length of body, 8 mm. ; of wing, 6 mm. ; of piercer, 5 mm. 

 One female, Cabima, Panama, May 17, 1911 (A. Busck). 



Differs from S. ferox T. in coloration only as follows : 

 Whole face and front deep golden. Palpi brown, lighter 

 apically. Mesoscutum golden, with four black vittae, the inner 

 pair shorter. Scutellum golden pollinose, with narrow black 

 base. Less than basal half of last three abdominal segments 

 brassy-silvery pollinose ; no interruption of pollen on the me- 

 dian line. Fuscous of wings slightly more diffused. Tegulae 

 nearly white, with only a faint tawny tinge. 



Holotype, Cat. No. 20799, U. S. Nat. Mus. 



The three genera Xiphomyia, Spathimyia, and Incamyia 

 form a compact group of tropical American flies with exagger- 

 ated piercer, evidently to be referred to the family Dexiidse 

 (Minthoidae and Pseudodexiidae, syns.), and subfamily Mac- 

 quartiinae. 



Hemithrixion oestriforme BB. — The characterization fits 

 Coquillettina plankii Walt, perfectly. Walton's species is prob- 

 ably distinct, but congeneric with oestriforme. If the char- 

 acter of the obliterated fourth vein prove inconstant, Buace- 

 myia will fall to Hemithrixion. 



Xanthomelanodes arcuata Say. — Wahlbergia atripenrds 

 Towns, (nee Phasia id. Say) is a synonym of this species. 

 Xanthomelanopsis, new genus. 



Genotype, Xanthomelanodes peruanus Townsend, 1912, 

 Proc. U. S'. Nat. Mus., XLHL 302. 



