352 Orthorrhapha brachycera. 



cells, and one at the apex of the cubital vein, one at the middle of 

 the last part of the discai vein and one on the posterior cross-vein; 

 besides there are brown patches in the first posterior cell, the discai 

 cell and below the postical vein; the veins are blackish, the last part 

 of the discai vein a little undulated. Squamulæ brown, v^ith a pale 

 fringe. Halteres yellow. 



Female. Epistoma a little broader than in the male, especially 

 above, grey, slightly yellowish. Legs quite as in the male. 



Length 2,2 to about 3 mm. 



H. nebulosus is not common in Denmark ; Dyrehaven ; in Jutland 

 at Silkeborg, at Hulslg north of Frederikshavn and on Læsø ; on Born- 

 holm at Almindingen. My dates are in July; Drewsen has recorded 

 it from Bøllemosen at the end of November. It occurs both at fresh 

 water and at the shore. 



Geographical distribution:— Northern and middle Europe down 

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



24. Liancalus Loew. 



Beautiful species of large or medium size and of green colours. 

 The genus is closely allied to Hydrophorus. Head a littie broader 

 than thorax, broader than high, a little arched behind. Vertex ex- 

 cavated, the ocellar tubercle prominent. Frons broad, decreasing in 

 breadth towards the antennæ. There are ocellar, outer vertical and 

 postvertical bristles, but no small hairs on the ocellar tubercle. Eyes 

 large, somewhat oval, only slightly narrowed downvi^ards; in the living 

 specimens they are green, with reddish reflexes above ; they are densely 

 hairy. The facets are of the same size. The eyes are well separated 

 in both sexes, the epistoma considerably broader in the female than 

 in the male. Jowls absent. The postocular bristles form a single row 

 on the upper half of the occiput, the lower half is densely covered 

 with long hairs. Antennæ inserted near to each other, somewhat 

 high above the middle; they are short, the first joint obconical, the 

 second simple, the third triangular or triangularly ovate; the arista 

 is dorsal (sometimes near the apex, hmnilis, non Danish), long, its 

 first joint somewhat short. The first antennal joint is bare, the 

 second has bristles at the apex, the third is short-haired and the 

 arista very short- or microscopically haired. Epistoma flat, below it 

 is separated from the clypeus by a small tubercle on each side at 

 the eye-margin, and between these is a somewhat indistinct, trans- 

 verse keel; the clypeus is arched and angularly rounded below; it 

 reaches to, or in the male almost to the lower margin ot the eyes. 



