Empididae. 21 



labrum, likewise strong, canaliculated, curved downwards and pointed. 

 There are no maxillæ, but one-jointed, ovate maxillary palpi with a 

 pair of bristles on the apex. Labiuni is of the same length as the other 

 parts, the labella are about as Jong as the basal part, somewhat 

 broad, cleft to tlieir base, and with bristles and a few pseudotracheæ. 

 Thorax is not elongated but almost square or roundish; it is very 

 high and very much arched above. On account of this shape of the 

 thorax the head is situated somewhat downwards on its front end. 

 Prothorax is small, a little neck-shaped; metathorax small. The 

 thoracic disc has uniserial dorsocentral and biserial acrostichal bristles, 

 the former are long behind ; besides there are some hairs at the sides 

 of the disc. There are humeral, posthumeral, notopleural, supraalar 

 and postalar bristles, but they are indistinctly discernible between the 

 other hairs and bristles at the sides. Scutellum with a number (about 

 four) of marginal bristles. Metapleura bare. Abdomen slender, con- 

 sisting of eight segments; the first is small; in the males the eighth 

 segment is small, generally hidden. The male genitalia small; they 

 consist of a small, fork-shaped piece below; on each side there is a 

 somewhat broad lamella, terminating in a small hook, and above 



Fig. 5. Wing of B. spuria. 



there is a pair of small, styliform lamellæ. In the female the abdomen 

 is pointed and terminates with two small, styhform lamellæ. The legs 

 are slender, the hind legs the longest; the hind tibiæ often a little 

 thickened towards the apex and the hind metatarsi more or less 

 thickened; the legs have shorter and longer hairs and bristles; middle 

 tibiæ with small apical or subapical spurs. There are two claws, 

 two pulviUi and a small, bristle-shaped empodium with bristles on 

 the lower side; also the claws are hairy. The wings have the media- 

 stinal vein not quite reaching the margin; the cubital vein is unforked, 

 thus one cubital cell ; the discai vein is forked , and there are four 

 posterior cells; generally the peduncle of the discai fork is more or 

 less indistinct and the base of the fork is generally incomplete, so 

 that the first and second posterior cells are not completely separated. 

 No discai cell; the second basal cell longer than the first; the lower 



