Syrphus. 



305 



the central knob blackish; jowls greyish black, sometimes yellowish. 

 Vertex and frons black-haired, the former with yellow hairs behind ; 

 epistoma yellovv-haired, above, at the sides of the antennæ, with black 

 hairs. Occiput greyish pruinose "with whitish hairs, yellowish upwards, 

 and there are no black hairs above; the occiput is somewhat puffed 

 out at the upper eye-margin. Antennæ black or blackish, more or 

 less reddish below the base of the third joint; arista not so long as 

 the antennæ. Thorax greenish æneous or more brass-coloured, not 

 much shining; postalar calli somewhat yellowish ; the thorax is clothed 

 with yellow hairs, dense at the sides. Scutellum dark yellow, some- 

 times bluish reflecting, with yellow hairs; there are sometimes some 

 black hairs on the disc. Pleura with long, yellow hairs. Abdomen 

 somewhat marginate, dull black, shining at the apex, first segment 

 greenish, shining; there are three pairs of broad, yellow spots; the 

 basal spots lying about on the middle, broadly separated ; they are 

 transverse, sloping forwards at the sides and going over the margin; 

 the spots on third segment are large, lying near the front margin, 

 they are slightly lunulate in front but straight behind and broadest 

 inwards, as they slope away from the front margin outwards, and they 

 go over the side margin above; they go near to each other in the 



s. corallae c?, abdomen. 

 Fig. 121. Typical specimen. Fig. 122. The common variety. 



middle and are very often here united, forming a band excised in the 

 middle of front and hind margins; the spots on fourth segment are 

 similar but quite near to the front margin, and they are nearly always 

 united to a band, which is generally incised only behind; they go 

 widely over the margin, and as a rule the margin from here and 



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