230 Syrphidae. 



Tidsskr. 2, I, 361,29 {Syrphus). — 1862. Schin. F. A. I, 291. — 1898. 

 Lundb. Vid. Meddel. Nat. For. Kjøbenh. 300, 90. — 1901. Verr. Brit. FL 

 VIII, 304, 1, figs. 261—262. — 1907. Kat. palåarkt. Dipt. III, 48. — Stjrphus 

 monochaetus Loew, 1871. Beschr. eur. Dipt. II, 224, 120. 



Male. Head a little broader than high and epistoma broad, con- 

 siderably broader than the diameter of the eye. Frons and epistoma 

 bluish black, somewhat whitish pruinose, the central knob shining. 

 Vertex, frons and epistoma with black hairs; the central knob small, 

 a little prominent. Occiput bluish black, a little pruinose, the hairs 

 yellow; above there are besides long, black hairs. Antennæ inserted 

 well above the middle, black, third joint brownish or blackish, paler 

 beneath at the base ; arista apparently bare. Thorax æneous or bluish 

 black, shining, clothed with long, white hairs. Pleura likewise with 

 long, white hairs. Abdomen dull black, just the base and the fifth 

 segment bluish shining; its markings much resemble those of P. aldi- 

 manus as there are three pairs of greyish, hoary spots; the spots are 

 somewhat subquadrate but broadest at the lateral margin, rounded 

 inwards ; the spots on second segment are smallest, somewhat triangular 

 and lying on the middle; on the third segment the spots are near the 

 front margin and on fourth segment close to the front margin. Ab- 

 domen is clothed with whitish hairs, longest at the sides, especially 

 towards the base; along the middle are some black hairs. Venter 

 bluish, shining, with longish, whitish hairs, shortest towards the end. 

 Legs mainly blackish, on the anterior legs the apex or apical part of 

 femora and the basal third or half of tibiæ yellowish; hind legs with 

 only the knees narrowly pale. Front femora a little thickened towards 

 the base; below on the basal part are about three or four bristles 

 which are black or mixed black and yellow; on the posterior side 

 are long, black, bristly hairs, arranged in a row outwards and ending 

 before the tip with a curious, long hair with the end curved round 

 or roUed; the hairs at the base yellowish; front tibiæ with short, 

 scattered, yellow hairs and on the posterior side with a row of some 

 long, black or yellow hairs below the middle ; the middle femora have 

 some long, black, bristly hairs on the antero-ventral side at the base, 

 and long hairs on the posterior side which are dark but more or less 

 pale towards the base; just below there are a couple of long hairs 

 before the middle; the middle tibiæ have short, scattered, yellow hairs 

 and long hairs behind; the hind legs are haired as usual with long 

 hairs on the anterior side of femora, for the rest short-haired but 

 with a fringe of longer hairs above tibiæ ; the hairs are all pale ; hind 

 metatarsus somewhat strongly swollen. Wings a little brownish 



