288 Syrphidae. 



Geographical distribution: — Northern and middle Europe down 

 into France; towards the north to northern Sweden, and in Finland. 



7. S. torvus Ost. Sack. 



1875. Ost. Sack. Proc. Boston Soc. Nat. Hist. XVIII, 139, 1. — 1901. 

 Verr. Brit. Fl. VIII, 356, 7. — 1907. Kat. palåarkt. Dipt. III, 70. — Scaeva 

 rihesii p. p. 1817. Fall. Dipt. Suec. Syrph. 40. — Scaeva topiaria Zett. (nec 

 Meig.) 1838. Ins. Lapp. 599, 4 et 1843. Dipt. Scand. II, 723, 26 et 1859. 

 XIII, 5095,26. — Syrphus topiarim 1862. Schin. F. A. I, 304. 



Male. Vertex brovvnish grey pruinose; frons brownish yellow 

 pruinose, above the antennæ a black, undusted, tridentate lunule, 

 emarginate behind in the middle. Epistoma yellow, somewhat dusted 

 towards the sides, shining in the middle, the extreme front mouth 

 edge narrowly blackish ; jowls darkened, greyish pruinose, quite behind 

 yellow. Vertex and frons black-haired, epistoma with yellow hairs, 

 towards the sides some black hairs, especially above, and also some 

 black hairs towards the middle. Occiput grey or yellowish grey 

 pruinose, the hairs yellow, above a row of some few black, over- 

 hanging hairs. Eyes distinctly and somewhat densely clothed with 

 short, pale hairs. Antennæ black, the third joint more or less brownish 

 beneath; the third joint ovate, longer than the two basal together; 

 arista as long as or a little longer than the antennæ. Thorax greenish 

 æneous, sometimes more brownish, dull, with three faint, more or 

 less visible darker stripes; it is distinctly punctate and it is clothed 

 with somewhat long, yellow or dark yellow hairs, darkest and most 

 conspicuous at the sides. Scutellum yellow, with black hairs. Pleura 

 with long, yellow hairs. Abdomen dull black, somewhat shining at 

 the apex; it has a pair of yellow basal spots and two bands; the 

 basal spots are transverse, placed on the middle of the segment, they 

 are widely separated in the middle, sloping forwards at the sides and 

 going over the margin with the upper side corner; the band on third 

 segment lies a little from the front margin, it is incised in the middle 

 of the hind margin and it slopes forwards at the sides, going over 

 the margin like the spots and here touching the front margin; the 

 anterior margin of the band is generally not straight but a little pro- 

 duced in the middle and slightly concave to each side, thus the band 

 may be said to consist of two in the middle more or less broadly 

 connected shallow lunules; the band on fourth segment is similar but 

 nearer the front margin; the fourth and fifth segments have yellow 

 hind margins, the latter also spots at the basal corners. The hairs 

 on abdomen foUow the ground colour, but are black at the apex; 

 at the sides they are long and at the base yellow, for the rest 



