102 H. C. EFFLATOUN. 



reddish-brown, as well as the trochanters), are covered with thin 

 whitish dust. The pubescence on the hind legs is also very short, 

 pale and inconspicuous. 



Wings pellucid with the stigma and the subcostal cell pah' 

 yellow, as well as the other veins at the base ; the vena spuria is 

 very often obsolete, and sometimes with a very short faint line 

 present at about its centre. Squamula? whitish with their margins 

 yellowish ; the thoracal pair possess long delicate white fringes 

 which are composed of compound hairs, but the alar pair with 

 coarser, simple whitish fringes which are only about one third of 

 the length of these on the thoracal pair. Halteres pale yellow 

 with the base brownish. 



Female: Rather similar to the male but larger and stouter. 

 Frons all covered with silvery white dust and some white hairs, 

 except on a short space just before the vertex which is somewhat 

 shining black together with the latter. The front facets of the 

 eyes are less dilated than in the male. The second segment of the 

 abdomen always with .a central black band, which meets the upper 

 and lower triangular bands and thus giving the yellow part of the 

 segment the appearance of being two large spots with almost 

 parallel margins ; these yellow spots are usually whiter towards 

 their distal ends, but redder towards the sides. Often the triangular 

 band at the base of the segment is absent, leaving the basal part 

 of the segment yellow, except in the centre, owing to the central 

 longitudinal band, which always reaches the basal margin. The 

 extreme lower margin of the second segment is yellowish. The 

 third segment has its lower half blackish with the broad longitu- 

 dinal median band reaching the basal margin, thus leaving the two 

 broad corners of the basal half of the segment whitish-yellow; the 

 lower margin of this segment is yellowish-brown. The fourth 

 segment is elongated, tapering and pointed and entirely shining 

 black, except for two yellowish-white spots on the basal corners and 

 the extreme tip yellowish. The first three segments are all dull 

 except for the lower margins of the second and third segments and 

 three spots (one in the centre near the base and two on the sides 

 near the lower margin), on the third segment, which are shining. 

 Venter rather more opacpie and darker than in the male. Hind 

 legs with the femora usually more orange, the spine near the base, 

 below, much smaller and weaker than in the male, and with the 

 hind tarsi usually much darker above. 



Length from 71- — 9 mm. 



S. spinigera is one of the commonest Egyptian Syrphids and 

 one of the most Avidely distributed. My records date from January 

 to November. It is known to occur in Africa, Asia Minor and 

 Si ■nth of Europe. 



