358 INSECTS. 



feature, however, is the long, slender, projecting pro- 

 boscis, little inferior in length to the body of the insect. 

 The antennae are long, pointed, and slender. 



Like the Humming-bird Moth, the Bee-fly may fre- 

 quently be observed eagerly hovering over a flower, and, 

 without settling, extracting honey by means of its long 

 proboscis. It resembles the Moth too in the suddenness 

 with which it darts away if approached while thus sus- 

 pended, apparently without motion, in the air. 



The history of its larvae is not yet fully known, and it 

 is a question whether they are parasitic in their habits, 

 or vegetarian. There are some insects in the family 

 which are known to be parasitic, but most of these are 

 rare. Thereva, one of the genera, contains predaceous 

 Flies. 



The eighth family, Scenopinidae, contains a few com- 

 mon but inconspicuous little black insects with rust- 

 coloured legs, found in houses and stables. 



Empidae is a numerous family of voracious insect- 

 eating Flies somewhat resembling Asilus in figure, but 

 generally of small or middle size. Their heads are small 

 and round, the antennae three-jointed, tapering, and ter- 

 minating in a point or bristle of one or two joints ; the 

 tongue is generally long, and when at work very con- 

 spicuous, whence these insects are sometimes called 

 Snipe-flies. The wings are without the rounded lobe in 

 the axil, which appears in nearly all the other Brachy- 

 cerous flies excepting those of the families Dolichopidae 

 and Lonchopteridae. 



Empis tessellata (PI. XV., fig. 2) is a dull, ash-coloured 

 Fly, with three longitudinal black streaks on the thorax, 

 legs long, strong, and spined, wings dusky and tinged 

 on the fore-part with reddish brown. It is very common 



