Empididae. 283 



Ch. incana will certainly be found to be common in many piaces 

 at our sea-shores; it has hitherto only been taken in 1909 at Tisvilde, 

 on Langeland at Lohals (the aiithor) and on Funen at Strib (Th. 

 Mortensen); my dates are Vt — ^7^- 1^ was present in great numbers 

 running together with the other species of CJiersodromia, and it was 

 taken several times in copula. This beautiful species was seen 

 especially at a little longer distance from the water than the other 

 species, where the sand was dry; in this place its light grey colour 

 coincided well with the colour of the sand, so that it w^as not easily 

 seen. 



Geographical distribution:— Europe and down into northern Africa; 

 it is not known north of Denmark and England. 



Remarks: Becker suggests (Zeitschr. fur syst. Hymenopt. und Dipt. 

 VII, 1907, 1 19) that the present species may be identical with spectilifera 

 Walk. ; 1 have determined my species by comparison with specimens 

 of incana sent to me from Mr. Verrall ; they agree in all respects, and 

 all have a black, polished spot on the pleura, but it is small and not 

 very distinct. 



26. Symballophtlialinus Beck. 



This genus is in most respects quite similar to the following genus 

 Tachydromia, I shall therefore only give the differences. The head is 

 globular, not higher than broad. The eyes are in both sexes touching 

 above the antennæ for a long distance; the facets in the front part of 

 the eye areenlarged; below the antennæ the eyes are separated. In the 

 living specimens the eyes are bluish violet. The antennæ are inserted 

 distinctly below the middle; the third joint has another shape than in 



Fig. 130. Antenna of S. dissimilis. X 130. 



Tachydromia^ its upper margin is straight so that it is dilated only 

 downwards. The maxillary palpi are not squamiform but band-shaped. 

 Epistoma is not narrow, and it is somewhat short. Thorax and ab- 

 domen as in Tachydromia. the former with somewhat indistinct 

 uniserial dorsocentral and biserial acrostichal bristles. One notopleural 

 bristle present. Scutellum with six bristles. The legs somewhat 

 slender; the femora not thickened, and the middle tibiæ without 



