Dolichopodidae. 143 



quite black third antennal joint, which is also shorter, and generally 

 by the more or less pale basal part of the middle metatarsus, this 

 being at all events somewhat reddish at the base, and only rarely 

 quite or almost quite black; further plumipes has a somewhat larger 

 axillary lobe, and the anal vein is directed more downwards than in 

 simplex^ though this character requires close examination to be correctly 

 judged. Stæger says, that the female of simplex has the third antennal 

 joint yellow below at the base, and Zetterstedt mentions varieties 

 with the third joint so coloured; I am strongly inchned to believe that 

 these authors have confounded the females of simplex and plumipes; 

 in Stæger's collection most females were now correctly determined, 

 and had also a black third antennal joint, but some females of 

 plumipes were intermingled. Also to pennatus the female shows 

 resemblance, but this is a larger species with the basal antennal joint 

 more black. 



D. simplex is common in Denmark; Copenhagen in gardens, 

 Amager, Damhusmosen, Charlottenlund, Ordrup Mose, Dyrehaven, 

 Lyngby Mose, Fure Sø, Ruderhegn, Hareskov, Hillerød, Gurre, Bose- 

 rup and Svenstrup near Roskilde, Frederikssund, Tisvilde, Rørvig, 

 Egholm at Skelskør; on Funen at Hoffmansgave; in Jutland in Greis- 

 dalen at Vejle, Nebsager near Horsens, Laven near Silkeborg, Frijsen- 

 borg, Søndervig, Holstebro, Gjerlev near Randers Fjord, Thisted, 

 Frederikshavn, Hulsig north of Frederikshavn and on Læsø; fmally 

 on Bornholm at Hasle, Rø, Hammeren and Almindingen. My dates 

 are '^^k — ^/o. It occurs on bushes and in low herbage, especially on 

 more or less humid piaces and near water, but also more remote 

 from water, and both near the shore and inland. 



Geographical distribution: — Northern and middle Europe down 

 into France; towards the north to northern Sweden, and in Finland. 



Remarks: I follow the Kat. palåarkt. Dipt. and Verrall in con- 

 sidering D. thalassinus Hal. as a synonym to simplex. Mik (Verhandl. 

 zool. bot. Geseli. Wien, XXX, 1880, 594, Taf. XVII, Fig. 2-5) tried 

 to distinguish the two species, and says, that the species described 

 by Stæger is thalassinus; this is certainly not so, and the characters 

 given by Mik are, I think, not valid; in the description of the hypo- 

 pygium he has no doubt committed some error, as I think it very 

 improbable, that any species of Dolichopus should have more than 

 two pairs of inner lamellæ, besides the posterior ventral lobes, and 

 the unpaired median dorsal appendage. — When Loew (Neue Beitr. 

 VI, 1859, 12) ascribes the male of simplex a long thin hair at the 

 tip of the front tibiæ, he has probably confounded the species with 

 notabilis or linearis. 



