2 13 Syrphidae. 



of feraora and tibiæ. Front femora vvith the peculiar, white hair at 

 the base, and it is often curved at the apex ; the hairs on the postero- 

 ventral side not short, and they increase in length towards the base; 

 also the hairs on middle femora somewhat long, and more or less 

 dark towards the apex. 



Length 0,8—9 mm. 



The larva is flat below, somewhat arched above; it is greyish 

 yeilow with a dark longitudinal dorsal stripe and some reddish markings 

 shining through the dermis; along each side is a paler reddish stripe; 

 it has, when full grown, a length of 10 mm. The puparium is dirty 

 white to pale yellowish, slightly transversely corrugated, with a short, 

 divided, brownish posterior spiracular process; it has a length of 5 to 

 fuUy 6 mm. 



This species is in the male known by the hairs on front femora 

 and middle tibiæ and the shape of the front tibiæ and tarsi; the 

 female bears resemblance to scamhus, immarginatus and fulviventris; 

 it has often much darker hind legs, but sometimes this character is 

 not present, though fulviventris always may be known from it by the 

 quite yeilow hind legs; for the rest it can be distinguished with cer- 

 tainty from scambus by the presence of the white hair at the base of 

 front femora and the other hairs being longer, and also by the smaller 

 basal abdominal spots ; from immarginatus by the longer hairs on 

 anterior femora and those on front femora being longest towards the 

 base, while they are of the same length in immarginatus, and further 

 it has larger antennæ with the third joint longer and the arista not 

 quite so short; from fulviventris it is likewise known by the hairs on 

 front femora being longer and longest at the base, and fmally it differs 

 from all three by the black sixth abdominal segment. — The species 

 varies in the male somewhat with regard to the hairiness of the front 

 and middle femora, as sometimes the stronger, curved hairs on the 

 front femora are less conspicuous, and as already stated, the middle 

 femora may have more or fewer small bristles on the front side, or 

 none at all. 



P. clypeatus is common in Denmark and may be taken on suit- 

 able localities, fens, meadows and in woods in all parts of our country. 

 My dates are ^^/s— ^o/g. I have taken the larva on Vesterfælled in flood 

 refuse of reeds on ^./4, and in Utterslev Mose on ^^A, they pupated 

 soon after and the imagines came in the first part of May; further I 

 took a larva in the same way in Damhusmosen on "^^/s, it pupated on 

 •r/4 and developed on ^^U, and it was taken in Ruderhegn on "/2, 

 pupating on ^''/i and developing on ^^l\ (Kryger); finally the species 

 has been bred from larvæ taken in flood refuse in Damhusmosen, 



