326 Syrphidae. 



parallel-sided : it is dull black with base, apex and the tvvo middle 

 incisures shining; the shining base includes Ihe fronl margin of the 

 second segment, and the incisures the hind and front margins of 

 second and third and of third and fourth segments and they are 

 rather definite; there are three pairs of yellow spots, the basal spots 

 lie behind the middle of the segment, they are triangular or more 

 transverse, well separated in the middle and going over the side 

 margin at their upper corners; the second pair lie well away from 

 the front margin, they are somewhat transversely rectangular, a little 

 oblique with the inner end more forwards than the outer; they are 

 near to each other in the middle, isolated from the side margin; the 

 third pair are similar; at the junctions of the four first segments there 

 are just at the sides small, yellow spots, one at each junction; the 

 fourth segment has a yellow hind margin, the tifth large basal corner 

 spots and the hind margin yellow. The hairs on abdomen are some- 

 what long. they are mainly yellow, only black at the hind margins of 

 the segments and at apex; at the sides they are long, longest at the 

 base and here yellow, otherwise alternating black and yellow. Venter 

 yellowish with long, pale hairs. Genitalia somewhat large, reddish or 

 brown, eighth segment black on the right side ; the hairs black. Legs 

 not long, a little robust; they are yellow or reddish yellow, anterior 

 femora blackish at the base, hind femora in about the basal half but 

 a little pale at the extreme base; hind metatarsi distinctly thickened. 

 The long hairs on anterior femora yellow on the base or in the basal 

 half, black towards the apex, on hind femora yellow; the short hairs 

 are black on the apical half of hind femora and on hind tibiæ, and 

 may also be more or less black on middle femora and tibiæ, for the 

 rest they are yellow. Wings slightly tinged. Squamulæ whitish with 

 a yellow fringe. Halteres pale to reddish yellow. 



Female. Vertex somewhat broad, this and the frons black and 

 shining all down to the antennæ, with small, grey dust spots at the 

 eye-margins; the hairs somewhat long, black. Antennæ distinctly 

 larger than in the male. Abdominal spots very slightly smaller than 

 in the male. Legs quite yellow, only hind femora a little black below 

 near the base. 



Length fully 8 to about 9,-5 nmi. 



This species is characteristic by the abdominal markings, broad 

 epistoma and robust legs with thickened hind metatarsi. 



S. euchronius is rare in Denmark, 1 know only four specimens, 

 Ermelund, Hillerød, Tyvekrog (the author), and one specimen from 

 earlier time without particular locality. My dates are ^■''/f. — '^/o. 



Geographical distribution: — Northern and middle Europe down 



