122 Syrphidae. 



C. virescens is somewhat rare in Denmark; Dyrehaven, Lyngby- 

 Mose (the author) and in Jutland at Sæby (H.J.Hansen); the dates 

 are from ^Ve to July; it was for the first time taken in 1881 and only 

 two specimens were known until this year (1915), when I took it in 

 some number in Lyngby Mose on ^^le — ^^Ig. 



Geographical distribution: — Northern and middle Europe down 

 into Styria and Bohemia; its northern limit seems to be in Denmark, 

 and it occurs in England. 



8. Cliilosia Meig. 



(Cheilosia). 



Species of somewhat large or medium size and of dark, black or 

 dark æneous colour, very rarely with greyish spots on abdomen ; they 

 are more or less hairy, sometimes with rather long, dense hairs, and 

 nearly always the male is much longer haired than the female. Head 

 about semiglobular, flat or slightly hoUowed behind, a little broader 

 than high and about of the breadth of thorax or slightly broader. 

 Eyes touching in the male, broadly separated in the female. P>ons 

 a little protruding in the male, with a longitudinal groove, in the 

 female trisulcate or only with lateral channels, generally also with a 

 slight transverse depression a little above the antennæ. Eyes bare or 

 witli more or less long and dense hairs; in a few cases hairy in the 

 male, bare in the female; the facets are in the male a little enlarged 

 in about the upper half. Antennæ inserted about in or a little above 

 the middle of the head; they are short, third joint usually circular or 

 roundish square, sometimes a little longer than broad; it may be 

 somewhat large and is as a rule larger in the female than in the male; 

 the basal joints small; arista inserted dorsally near the base of the 

 third joint; it is thread-like, a little thickened in the basal part, with 

 two very small basal joints; the basal antennal joints have small 

 bristles at the end margin, largest above and below the second joint; 

 the third joint densely microscopically hairy; the arista with shorter 

 or longer, but always rather short hairs, sometimes apparently bare 

 i, e. microscopically hairy. Epistoma more or less hollowed below the 

 antennæ, sometimes only slightly; it has, about in the middle or lower 

 down a central knob, which may vary very much in size and breadth 

 and be more or less prominent ; below the knob the epistoma is again 

 more or less hollowed between the knob and the front mouth edge; 

 when this latter is not prominent there is no hoUow, the epistoma 

 then only retreats below the knob ; the whole lower part of epistoma, 



