512 Syrphidae. 



5. Abdomen quite black, or with golden hairs at apex 6. 



— Abdomen with yellow or glaucous spots 7. 



6. Abdomen with no golden hairs at apex; all femora and 



anterior tibiæ red o. femorata. 



— Abdomen with the apex covered with golden hairs; femora 



black 6. sylvarum. 



7. Hind femora rather thick, hind tibiæ somewhat short, distinctly 

 curved and with an erect eilation below; fourth abdominal 

 segment quite or mainly pale-haired, the hairs long at the 



hind margin; hind trochanters in the male simple 7. nemorum. 



— Hind femora almost not thickened, hind tibiæ longer and 

 very slightly curved, without erect ciliation below; fourth 

 abdominal segment mainly black-haired, the hairs all short; 



hind trochanters in the male with a small spur 8. ftorum. 



1. X. segnis L, 



1758. Linn. Syst. Nat. X, 595 et 1767. XII, 2, 988, 57 et 1761. Fn. 

 Suec. 1823 {Musca). — 1775. Fabr. Syst. Entom. 772, 47 [Syrphus) et 1805. 

 Syst. Antl. 191, 14 (Milesia). — 1816. Fall. Dipt. Suec. Syrph. 10, 5 (Milesia). 

 — 1822. Meig. Syst. Beschr. III, 220, 12. — 1843. Zett. Dipt. Scand. II, 

 874, 5. — 1862. Schin. F. A. I, 354. — 1901. Verr. Brit. Fl. VIII, 598, 1, 

 figs. 408—409. — 1907. Kat. palåarkt. Dipt. III, 130. 



Male, Vertex bluish black, shining; frons and epistoma paler or 

 darker yellow to brownish pruinose, the lower side parts of epistoma 

 black; vertex with yellow hairs, frons with pale hairs only just along 

 the eye-margins, and also epistoma only with slight hairs on the eye- 

 margins. Occiput greyish white pruinose below and upwards beyond 

 the middle, æneous and shining above; the hairs white below, yellow 

 above. Antennæ blackish, third joint dark brown; sometimes the 

 antennæ paler; arista black, pale at the apex. Thorax from dark to 

 rather bright æneous, shining, densely punctate, especially behind; it 

 has a whitish pruinose spot inwards to the humeri ; it is clothed with 

 short, yellow hairs, among which are some longer hairs on the hind 

 part; also on the sides and on the postalar calli are longer hairs; in- 

 wards to the wing-root are short, strong, black hairs. Scutellum 

 æneous with short and longer, yellow hairs and along the margin 

 some long, almost bristly hairs, Pleura slightly pruinose with longish, 

 whitish, above yellow hairs; just below the wing-root some darker 

 hairs. Abdomen hnear, yellowish red on the middle; first segment 

 æneous, second yellowish red with the extreme front margin black 

 and almost always a shorter or longer, narrow, black pointed middle 

 line from the front margin backwards; third segment reddish yellow 

 with the hind margin, sometimes the hind part black, generally pro- 

 duced a little forwards in the middle; fourth segment bluish black, 



