134 FLIES. 



covered with yellowish brown hairs. The honey- 

 yellow legs are quite slender, the hinder pair- 

 being much longer and more thickly beset with 

 bristles. The compound eyes are large and full, 

 and the head is armed with a proboscis nearly as 

 long as the thorax and abdomen. The base and 

 front of the wings are brownish, while the lower 

 halves are nearly transparent, clouded on the 

 cross-veins and curves. The venation, especially 

 on the front edge, is large and rigid, showing how 

 well adapted it is for rapid flight. 



This species, I am convinced, is particularly 

 fond of invading the homes of the sand bees, for 

 I have seen it playing up and down over a flour- 

 ishing borough, evidently searching for some 

 unguarded tunnel. 



Some of the boldest and most impudent of the 

 diptera actually glue their eggs on the abdomen of 

 the adult wasp, and the larva, as soon as hatched, 

 begins to eat its way between the segments, and 

 there lives for several days on the juices of these 

 armed insects. 



There is a species of fly called syrphus politiis, 

 so cunning and accomplished, as its specific name 

 would imply, that it hunts for yards or groups of 

 plant-lice, and in the midst of them it lays a 

 single egg. The little green and purple larva 

 wakes up to find itself surrounded by a swarm of 

 sweet-meated aphids, and immediately it stretches 



