HOUGH: SOUTH AMERICAN MUSCID.E. 225 



-egmeiit ; all are appressed save those of the fourth and those 

 toward the sides of the third. Toward the sides of the third 

 segment there are three or four small discal microchceta>, and 

 on the fourth segment in a complete row of discals. The female 

 has about the same arrangement, but on the first two segments 

 the bristles are mere hairs ; on the third only one or two of the 

 marginals. Those at the extreme sides of the segment are not 

 appressed, and there are but one or two discals situated at the 

 extreme lateral borders of the segment. 



The legs vary in color from brown to black. The bristles of 

 the fore leg are as usual in this genus. The middle femur pre- 

 sents the usual partial row along the center of the anterior sur- 

 face from base to middle, ending with one prominent bristle; 

 the preapical transverse group has three members, all on the 

 posterior surface. The middle tibia has no bristles except two 

 on the posterior surface ; both are in the middle third, one near 

 its base, the other near its apex. The bristles of the hind femur 

 are as usual. The hind tibia has on the lateral surface near the 

 llexor border one bristle near the middle (and in one male a 

 second, much more delicate, a little basad the other), and near 

 the extensor border a row, beginning a little basad the middle of 

 the tibia and running toward but not to the apex ; this row varies 

 in number from three to five ; possibly when less than five are 

 present some have been broken off, but I can see no scars. 



The palpi are orange yellow, thickly beset with short, coarse 

 black bristles. 



The antenna' are brownish yellow, with a thin pollinose coat- 

 ing ; sometimes the color is paler, and sometimes, especially 

 on the second joint and toward the apex of the third, darker. 

 The third joint is almost or quite three times as long as the 

 second. The arista is thickly plumose with long hairs, and its 

 rachis is yellow at its base. 



The wing is almost hyaline. In most specimens there is a 

 very faint brownish-yellow color most pronounced along the 

 -econd vein and near the costa. One or two specimens have 

 the cross-veins faintly clouded with the same color. The third 

 vein has from two to four spines at its base on both surfaces of 

 the wing. The wing is shown in figure 13. 



Length of body, 6 to 7 mm. 



