NO. 1935. MU8C0ID FLIES FROM SOUTH AMERICA— TOWNSEND. 309 



along veins, clear on inner border. The third antennal joint is four 

 times as long as second. 



Type.— Csit. No. 15147, U.S.NJI. Female, April 11, 1911; TD 

 4026,/. r. s. 



Deposits uncolored maggots on or near host. 



CESTROGASTER, new genus. 



Head in profile flattened-hemispherical, the oral margin abruptly 

 cut off and scarcely showing, the eyes extending from vertex almost 

 to peristomalia. No palpi, proboscis very short and fleshy. Vibrissas 

 inserted a little above oral margin, facialia perfectly bare. Parafa- 

 cials reduced to mere lines, cheeks about as wide as third antennal 

 joint. Front long and narrow, equilateral, about one-sixth greatest 

 width of head. The parafrontals are only a little wider than the 

 paraf acials, being about one-half width of frontalia. Antennae inserted 

 low, face being much shorter than front; arista long and hairlike, 

 enlarged on extreme base. No ocellar bristles. There seem to be 

 two prochnate orbital bristles, indicating the female, but they are 

 almost in line with the frontal bristles, due to the very slight width of 

 the parafrontals. 



Two sternopleural bristles and three postsufcural bristles. Scutel- 

 lum with one long nondecussate apical pair, and one long subbasal 

 lateral pair; only short bristles between these. Abdomen subglobose, 

 arched and of unique build, the venter being subcarinate, the external 

 genital opening approximated to posterior edge of first segment, the 

 dorsal scleritesof intermediate segments narrowing rapidly on sides and 

 their posterior margins directed obliquely forward to the hind margin 

 of first segment where they meet on median hne. The anal segment is 

 invisible in a direct downward view, but is brought forward on venter 

 in an arched surface extending to the point of meeting on median Hne 

 of the lateral apices of dorsal sclerites of intermediate segments, the 

 parts bounding genital orifice being evidently a continuation of the 

 abdominal sclerites. A median marginal pair of macrochsetsB but no 

 discal on first two segments, the third segment with a discal pair and 

 a marginal row; the anal segment with five or six median pairs in a 

 line which appear to be and may be called discal, but which corre- 

 spond to the normal discal and apical bristles. Claws and pul villi 

 short. Apical cell narrowly open in wingtip. Wings broad, fourth 

 vein rounded at bend, hind crossvein in middle between small cross- 

 vein and bend. Costal spine hardl37" at all developed. 



Reproductive habit unknown, but judged to be larviposition on or 

 near host. 



Type-species. — (Estrogasier fumosus, new species. 



