Empididae. 27 



distinctly thickened. The femora have dorsal and ventral rows of 

 hairs which are short on the anterlor femora, but long on the hind 

 femora, and those on the dorsal side considerably longer than the 

 femora are broad ; the tibiæ with similar rows the hairs of which are 

 dense and short on the ventral side, longer and less dense on the 

 dorsal side; they are longest on the hind tibiæ; all tibiæ have some 

 longer bristles on the dorsal side; the usual dense pubescence on 

 front and hind tibiæ present; tarsi short haired, a little longer on the 

 dorsal side of the hind tarsi. The hairs and bristles are black or 

 blackish. The wings are slightly brownish fumigated with a light 

 reddish tint, and somewhat iridescent; there is a more saturated part 

 at the anterior margin, but it is only slightly pronounced, it is bor- 

 dered as in the preceding species, but sometimes somewhat indistinctly. 

 Veins darker or paler brown; discai vein thin but distinct, the fork 

 generally incomplete, the upper branch more or less interrupted at 

 the base. The apical part of the mediastinal cell brownish. Halteres 

 more or less pale brown. 



Female. Thorax as in the male; abdomen more greyish, the 

 hairs shorter. The two first joints on the hind tarsi a little less thick- 

 ened. Halteres yellow or dirty yellowish. 



Length 3,3 — 4 mm. 



This species is rather easily distinguished from intermedia by the 

 longer, more slender and longer-haired legs, and the very distinctly 

 thickened joints on the hind tarsi, as also by the lighter-haired abdomen 

 and the less tinged wings; besides it is generally larger. As mentioned 

 the hind femora are short in spuria, longer in intermedia and still 

 longer in nigra; this may also be seen by counting the long hairs in 

 the dorsal (postero-dorsal) row, spuria shows about twelve, intermedia 

 about fifteen and nigra about twenty two. 



B. nigra is in Denmark less common than spuria, but it frequents 

 the same localities; Dyrehaven, Geel Skov, Birkerød, Tyvekrogen, 

 Nøddebo, Tisvilde; on Fænø and in Jutland at Hald near Viborg. 

 My dates are ^^/5 to the first part of August. 



Geographical distribution; — Northern and middle Europe down 

 into France; towards the north to middle Scandinavia. 



5. B. pilosa n. sp. 

 Male. Epistoma blackish; occiput blackish grey with dense, black 

 hairs. Antennæ black. Thorax black, somewhat shining, with an 

 indication of two stripes, The acrostichal and dorsocentral bristles 

 long, and likewise the bristles at the sides of the disc; the hinder 

 bristles not much longer. Scutellum greyish, with strong marginal 



