A Monograph oj Egyptian Diptera. 95 



resembling an urn. The third segment has its upper half nearly 

 always all orange, while its lower half possesses a black hand 

 which is deeper and wider than the one on the previous segment 

 and is also widest at its middle; this black band runs right 

 across the disc to the side-margins before the orange hind margin; 

 sometimes this black band is continued upwards in the centre in a 

 thin black line to the upper margin. The fourth segment is black- 

 ish with an orange hind margin, but is rather inclined to grey 

 near the front margin. The fifth segment is black and rather 

 retracted in the fourth. Pubescence very short and even on the 

 three first segments, where it is usually pale yellow; on the fourth 

 and fifth segments it is longer and denser. Venter orange with the 

 black dorsal markings showing through by transparency ; the sixth 

 and seventh segments are black and completely retracted into the 

 fifth; pubescence thinner but longer than on the dorsum. Hypo- 

 pygiuin asymmetric and dull brown. Legs black and orange, the 

 orange being on the apical sixth of the front and middle femora, 

 the basal halves of the front and middle tibiae and the middle 

 metatarsi; the hind legs are entirely black except the apices of the 

 tibia? which are brownish; the hind femora are considerably dila- 

 ted and the hind tibia? are conspicuously curved, (PI. II. fig. 4) com- 

 mencing with a jerk soon after the base; these hind tibiae possess 

 beneath, an elongated groove, which is bordered on each side by a 

 fairly prominent ridge; the outer ridge is hollowed beneath at the 

 tip and resembles a short spine, while the inner one is prolonged 

 lower down to the base, also hollowed beneath at the tip and 

 resembles a strong curved tooth ; on the joint between the hind 

 tibiae and tarsi there is a tuft of remarkable black globiferous 

 hairs, (PI. II, fig. 7.). Pubescence on the anterior legs abundant and 

 orange on the outer side only, the inner side being quite bare and 

 somewhat shining; on the outer side of the posterior tibiae it is 

 longer, more tufted and yellow, while on the inner side it is blackish. 



Wings grey and shining ; there is a small dark brown spot 

 under the end of the subcostal vein and a distinct cross-vein from 

 the subcostal vein to Radius 1; Median cross-vein much undulated. 

 Squamulae large and pale yellow with dense pale yellow fringes and 

 the disc orange. Halteres yellow. 



Female : Similar to the male but differs from it by the wide 

 separation of the eyes and by the pubescence of the thorax, abdo- 

 men and legs being shorter and somewhat paler; also the central 

 black longitudinal band on the second segment of the abdomen is 

 very often interrupted in the middle, leaving only the top and the 

 base of the urn-shaped marking ; the tibiae, although conspicuously 



