Diptera from South Africa. 175 



the two anterior pairs of legs, besides tho e at the tip of the 

 tibiae. 



In the two male specimens there are no bristles on the fore 

 femora, but a few long yellowish hairs, there are some black 

 bristles on the side of abdomen, the male organ is blackish 

 witli short white pubescence, and the anal appendage bright 

 red. 



Alcimus longurio, Loew, Dipt. Siidafrik. p. 137 (1860). 



Two females from Durban ( W. L. D.) are evidently the 

 female of the above. Loew described the male only. They 

 differ from his description thus: — 



The thorax in one of the specimens has the median black 

 stripes very narrow, posteriorly merged in one broad black 

 stripe; in the other it is divided by only a narrow umber- 

 brown line. The fore tibia? and the apical half of the posterior 

 ones, and the first joint of the fore and posterior tarsi, clothed 

 with short fulvous pubescence on the inner side ; the basal 

 half of the tarsal joints is dark red. The moustache extends 

 to the antenna?, with a few black bristles intermixed with some 

 long yellow hairs. The last segment of abdomen is wholly 

 biack, shining. 



Alcimus tristrigatus, £ , Loew, Dipt. Siidafrik. p. 134, tab. i. 

 fig. 51 (1860). 



One male from Pretoria ( W. L. I).). 



The third joint of antenna?, which was wanting in the 

 type, is black, and the bristle the same. 



Two females from Pretoria (W. L. D.). 



Though these vary somewhat from the male, I feel con- 

 vinced they are the same species, their general appearance 

 being identical. They differ from the description of the male 

 in the following particulars : — 



Antenna? wholly black, the moustache continued to the 

 antennas as a few scattered white hairs ; cheeks black; palpi 

 black, with yellow hairs. The middle stripe of thorax is 

 darker, the two narrow black lines on the side-stripes of the 

 male here become respectively a triangular and an oblong- 

 spot; the bristles on the posterior half are black instead of 

 yellow ; the hairs on the scutellum are all yellow. On the 

 abdomen the dark spots become a broad band on each segment 

 not reaching to the posterior margin ; the last segment is 

 wholly black, shining ; the pubescence on the bands is 

 yellowish, giving them a fulvous appearance, elsewhere 

 whitish. Lpgs black, the tibia? on basal half reddish ; the 



