Empididae. 279 



hairs downwards, Antennæ black, the arista paler towards the apex. 

 Thorax black, but distinctly greyish pruinose, with irregularly biserial. 

 short acrostichal bristles and longer, uniserial dorsocentral bristles; 

 besides the sides of the disc are clothed with short hairs. Further a 

 humeral bristle, a posthumeral, some notopleural, a supraalar and a 

 postalar bristle. All hairs and bristles black. Scutellum with two 

 long, black marginal bristles, and a short outer bristle on each side. 

 Pleura grey pruinose, above the middle coxæ a strongly shining, black, 

 polished spot. Abdomen black, somewhat greyish pruinose, with short, 

 dark hairs. Venter similarly coloured and haired. Exterior genitalia 

 large, as broad as the last abdominal segment, slightly shining, and 

 terminating with some hooks. Legs black or reddish brown, some- 

 what greyish pruinose; the front femora only slightly thickened. The 

 anterior femora with fine, longish hairs below ; all femora with a 

 long bristle on the anterior side near the apex; the front tibiæ short- 

 haired with a pair of long, subapical bristles on the ventral side; 

 middle tibiæ densely short-ciliated below, with one ventral subapical 

 bristle, but otherwise without bristles; hind tibiæ with bristles on the 

 dorsal, anterior, and antero-ventral side; hind metatarsi considerably 

 longer than the second joint, with a small bristle on the posterior 

 side. The hairs and bristles mainly black. Wings a little brownish^, 



Fig. 1'27. Wing of Ch. cursitans. 



especially towards the anterior margin. The veins dark brown, the 

 discai vein pale from the base to a liltle beyond the postical cross- 

 vein; this latter a little oblique; the radial vein terminating much 

 nearer to the apex of the subcostal vein than to the apex of the 

 cubital vein. Halteres blackish, the peduncle reddish. 



Female. Similar to the male; abdomen pointed. 



Length 1,8 — 2,4 mm, 



Ch. cursitans is probably not rare in Denmark at the shores, but 

 it has hitherto only been taken at Vemmetofte in June 1884 (H. J. 

 Hansen), on Langeland at Lohals, where it was taken in great numbers 

 on 2/7 1909 (the author) and in Jutland at Hald Sø on the sandy 

 border on ^^'c 1910 (the author). It runs on the humid sand almost 

 quite down to the water; when chased it flies for a short distance. 



