Enipididae. 301 



11. T. pallidiventris Meig. 



1822. Meig. Syst. Beschr. 111, 82, 35. — 1842. Zett. Dipt. Scand. I, 

 277, 6. — 1862. Schin. F. A. I, 88 {Flatij palpus). — 1903. Kat. palåarkt. 

 Dipt. 11, 287. — Tachijdromia longiseta: 1842. Zett. Dipt. Scand. I, 278,7. 



Male. Frons and vertex grey; epistoina white; palpi not large, 

 yellow. Oeciput grey, with yellow bristles above, white hairs below. 

 Antennæ black or brown, the basal joints yellow, the third joint 

 somewhat elongated, about as long as the arista or a little shorter. 

 Thorax yellowish pruinose; all bristles yellow; the short hairs in front 

 distinct and obvious. Scutellum with two yellow marginal bristles, 

 and a small hair on each side. Pleura grey pruinose, a little yellowish 

 upwards; above the middle coxæ a black, polished spot. Abdomen 

 black, shining, the two flrst segments with grey bands at the sides; 

 it is clothed with short, yellowish hairs. Venter blackish or paler to 

 yellow, especially towards the base. The exterior genitalia somewhat 

 large. Legs yellow, the tarsi blackish or brownish annulated, the last 

 joint generally deep black for the largest part. The front femora 

 somewhat, the middle femora considerably thickened. The legs are 

 yellow haired, front and hind tibiæ with some small bristles on the 

 dorsal side, these bristles may be darker. 

 Wings hyaline or a little yellowish. The 

 veins yellow, a little darker towards the 

 apex, the cubital and discai vein some- 

 what convergent. Balteres whitish yellow. 



Female. Similar to the male; the 

 venter sometimes more distinctly pale. 



Length 2,5 to about 3,-5 mm. ^'^'l^''- ,^^;!^=-Pf^.^ "^' 



The species is very similar to bicolor; 

 I find it distinguished by the distinctly longer third antennal joint, 

 the thicker anterior femora, and the distinctly annulated tarsi ; the 

 cubital and discai vein are as a rule more convergent, especially the 

 cubital vein is generally curved downwards, while it is about straight 

 in bicolor, the curvature of the discai vein may, on the contrary, 

 often be similar in the two species. Also the pale venter is a helping 

 character, but not always present, and also other species may show 

 the venter somewhat pale. Further I think the bristles, and also the 

 short hairs, on thorax are longer, and there are three distinct noto- 

 pleural bristles, but only two in bicolor. 



T. pallidiventris is a common species in Denmark, and more 

 common than bicolor; Copenhagen in gardens. Amager, Hellerup, 

 Ordrup Mose, Ermelund, Nøddebo, Tyvekrogen, Tisvilde, Frederiks- 



