238 THOMAS SAY FOUNDATION 



hypopygium; the free part bends back at an angle, 

 then curves gradually forward to a rather blunt 

 point ; at the basal part of the curve behind there is a 

 small hump, increased in appearance by dense, short, 

 erect hairs; accessory plate very small, rounded at 

 tip, with almost no free part; posterior clasper black, 

 stout, much curved, with hooked tip ; anterior clasper 

 small, slender, black, resting up against the front side 

 of the posterior; penis black; basal joint impercepti- 

 ble, distal one widening towards apex, where it ends 

 in an oblique funnel with a white margin; from each 

 side of the segment arises a heavy^ black simple arm, 

 which projects outward, forward, and toward the 

 base ; from near tlie base in front arises an erect slen- 

 der transverse black plate, recurved and divided at 

 tip ; back of distal segment sharp and keel-like toward 

 the tip. 



Legs black; middle femur with pronounced 

 comb; middle tibia with two bristles on outer front 

 side ; hind tibia not villous. 



Wings hyaline; costal spine as long as anterior 

 crossvein; third costal segment only about two-thirds 

 the fifth; first and third veins hairy. 



Female. Front narrowest at vertex, where it is 

 .271 of head (average of five,— .258, .265, .272, .279, 

 .282) ; abdomen flat, wide; fourth segment with sub- 

 marginal bristles as in male; genital segment j^ellow, 

 the aperture slitlike, with only a few bristles; hind 

 femur without comb. 



Length 6% to 8l/^ mm. 



Twenty-one males and six females; three males 

 are from La Fayette, Ind., June(Aldrich) ; one male, 

 one female, Evans\alle, Ind., swept on winter wheat 

 May 7, 1914 (Aldricli) ; twelve males, three females, 

 Opelousas, La., in the Hough collection; two males, 

 Crowley, La., in Professor Hine's collection; one 

 male Nebraska and one female Algonquin, 111. 

 (Hough coll.) ; one female Vinton, O. (Hine) ; one 

 male San Augustine, Tex.; one male Attica, Ind., 

 October 7, 1916 (Aldrich). 



