NO. 2152. NEW MUSCOID FLIES— TOWNSE^^D. 311 



ARGYROTHELAIRA, new genus. 



Genotype. — ArgyrotJielaira froggattii, new species. 



Differs from Thelaira as foUows: Female. Face and front much 

 narrower, the face of same width as anterior part of front, the front 

 gradually narrowing behind, the vertex hardly over one-fifth head- 

 width. Antennae longer, reaching oral margin, third joint fuUy 

 three times the second. Arista long, hair-like, bare. Parafacials 

 very narrowed below. Two inner reclinate orbitals, posterior pro- 

 chnate orbital set much farther forward, no oceUars. Outer vertical 

 developed. Frontalia narrow, not as wide as one parafrontal. Palpi 

 much thickened apically. Four postsuturals. Three strong lateral 

 scuteUars. No discals on intermediate abdominal segments. Wings 

 not so broad, cubitus nearer to margin. Third vein bristly oidy at 

 base, first vein bare. Seems allied to EutJielaira, from which it dif- 

 fers in the bare faciaha, eyes only very thinly hairy, and other points. 



ARGYROTHELAIRA FROGGATTII, new species. 



Length of body, 7.5 mm.; of wing, 6 mm. One female, Solomon 

 Islands, July-August, 1909 (W. W. Froggatt). Labeled " Masicera 

 immersa Walker," by Coquillett, which species was described from 

 Makassar, Celebes. The description does not apply. 



Head black; face, cheeks, parafrontals, orbits, and occiput silvery 

 white; palpi, antennae and frontaUa black. Thorax and scuteUum 

 black, pleurae and humeri silvery wliite, the dorsum thinly poUinose 

 leaving a pair of hnear vittae. Abdomen black; the sides of inter- 

 mediate segments broadly burnished silver-white not meeting on 

 median line, the sides of anal segment narrowly silvered. Legs 

 black. Wings smoky on costal border, diminishing along veins. 

 Tegulae nearly white. 



Eolotype.—^o. 20038, U.S.N.M. 



Named in honor of Prof. W. W. Froggatt. 



MEGISTOGASTROPSIS Townsend. 



Megistogastropsis Townsend, Ent. News, vol. 27, 1916, p. 178. 



Genotype. — Megistogaster wallacei, Brauer and Bergenstamm, 1889, 

 Muse. Schiz., pt. 1, p. 127. 



This is Brauer and Bergenstamm's sense of Megistogaster. For 

 characters, see Brauer and Bergenstamm.^ The authors accredit 

 the species to DoleschaU, but I can not find that he described it. It 

 was probably a manuscript name of his. 



The type of Megistogaster is fuscipennis Macquart, which Brauer 

 states is identical with petiolata Wiedemann. The genus is thus a 

 synonym of Cordyligaster. 



» Muse. Schiz., pt. 1, p. 127, pi. 8, fig. 210; and pt. 3, p. 129. 



