234 Syrphidae. 



middle segments about twice as long as broad; the spots as in mel- 

 Unum, but they are all more elongate. Legs paler than in mellinum 

 as the anterior legs are generally yellow; hind femora and tibiæ have 

 generally a dark ring of which there are in the highest faint traces 

 on the anterior legs; front and hind tarsi generally darkened. The 

 hairs on the anterior femora a little longer, and hind femora with 

 somewhat long, fine, almost bristly hairs below. Wings a little longer 

 than in mellinum. 



Female. Similar to the female of mellinum, but the frons with 

 large dust spots, often united in the middle; epistoma distinctly 

 pruinose as in the male. Abdomen longer than in mellinum, but this 

 difference, however, less pronounced than in the male; the second 

 and third pairs of spots generally more suddenly incurved on the out- 

 side just after the base, the outer margin thus more concave than in 

 mellinum and the spots narrower on the hind part ; fifth segment with 

 a pair of transverse spots at the base. Legs as in the palest speci- 

 mens of mellinum, either almost quite yellow or with more or less 

 distinct dark rings on hind femora and especially tibiæ, and front and 

 hind tarsi more or less darkened. 



Length 8 — 8,7 mm. 



This species is in general distinguished from mellinum by its 

 larger size, more elongated shape and the distinctly pruinose frons 

 and epistoma; further by the paler antennæ and legs; when these 

 characters should not be sufficient, the distinctly pubescent arisla of 

 scalare will, when carefully examined, decide the question. 



M. scalare is almost as common in Denmark as the preceding 

 and found on similar localities in all parts of the country. My dates 

 are i»/5— ^g/s. 



Geographical distribution: — All Europe, towards the north to 

 northern Scandinavia, in Finland and on the Faroe Islands; further 

 in North Africa down to Kilimandjaro. 



Obs. Melanoid specimens of the females of both the latter species 

 are recorded as not uncommon; I have seen Danish specimens with 

 the spots small, dark and rather inconspicuous, but I have never seen 

 any quite melanoid specimen from Denmark. 



12. Xantliandpus Ven. 



This genus, which was separated from Melanostoma by Verrall in 

 1901 is very nearly allied to that genus in the most essential charac- 

 ters. Eyes bare; the facets slightly enlarged above in the male. 

 Antennæ inserted about in the middle of the head, third joint con- 



