AET. 20 NOTES ON THE MUSCOID FLIES REINHARD J 



one hairlike); supraalar 3; postalar 2; sternopleural 2, 1; scutel- 

 lum with two pair of lateral bristles, the posterior ones largest; a 

 well-developed decussate apical pair; preapical pair also well de- 

 veloped; discal pair hairlike; postscutelliim only slightly developed, 

 membranous above; infrasquamal hairs present; halteres yellow; 

 calypters tawny. 



Abdomen black, with dense gruj pollen that extends to the hind 

 margins of all segments, black reflecting spots on segments 3 and 4 

 and a narrow dark vitta widening basally apparent when viewed 

 from behind; first segment with a row of marginal bristles which 

 are hairlike or incomplete above; segments 2 and 3 each with a com- 

 plete marginal row, no discals present; fourth segment with a mar- 

 ginal row and numerous almost equally strong irregularly placed 

 discals; first genital segment rather large, black, tinged faintly with 

 yellow apically, a narrow shining black transverse band crossing the 

 middle, otherwise thinly gray poUinose; fifth sternite unusually 

 prominent, deflected downward at a rather sharp angle, with a 

 broad U-shaped incision, the lobes thickly covered with rather fine 

 short black hair ; genitalia not in position to examine. 



Legs yellow, except tarsi, which are black; claws and pulvilli 

 elongated; middle tibia with one bristle on the outer front side; 

 hind tibia not ciliate. 



Wings large, normal shape, tinged with yellow at base and along 

 costal margin; all veins light yellow, bare, except third, which has 

 three or four short black bristles at the base; fourth vein broadly 

 curved without a definite angle at bend, ending at wing tip, nar- 

 rowly closing first posterior cell; hind cross vein about midway 

 between bend and small cross vein; costal spine distinct, doubled. 



Length, 7 mm. 



Described from one male received from Dr. J. M. Aldrich, collected 

 August 19, 1914, Fabyans, N. H. (C. H. T. Townsend), on flowers 

 of Solidago. 



Tyjje.—Msile, Cat. No. 41986, U.S.N.M. 



The black densely gray pollinose abdomen readily separates the 

 species from hicolor. It differs further from that species by having 

 the fourth vein broadly bowed without a definite angle, arista with 

 shorter hairs above and practically bare beneath, etc. 



OPSODEXIA CRUCIATA, new species 



Male. — Front greatly narrowed above and hardly as wide as ocellar 

 triangle; median stripe blackish, triangular below, reduced to a line 

 posteriorly, extending on each side of triangle to inner vertical; 

 paraf rontals narrow above, widening almost to width of the median 

 stripe at base of antennae; f rontals in two rows of about eight bris- 



