470 THE STUD Y OF INSECTS. 



VIIj coalesces with vein V3 , as shown in the figure; but 

 in the males the tip of vein VI I^ is free. The posterior 

 lobe is wanting. 



Three ocelli are present. The antennae are three-jointed ; 

 the third segment is globular, and bears a three-jointed 

 style. 



These flies are common from spring till autumn, in damp 

 grassy places. They frequent the shores of shady brooks^ 

 where the atmosphere is moist. But Httle is known as yet 

 about their habits and tranformations. 



In the shape of the wings, the absence of cross-veins,, 

 except at the base of the wing, and the great reduction of 

 the anal area of the wing the flies closely resemble the Psy- 

 chodidae. 



Suborder Cyclorrhapha (Cy-clor'rha-pha). 



The Circular -seamed Flies, 



To this suborder belong those families of flies in which 

 the pupa escapes from the larval skin through a 

 round opening made by pushing off the head- 

 end of it (Fig. 573). The pupa is always enclosed 

 in a puparium. The adult flies possess a frontal 

 lunule (see footnote page 461), and except in the 

 Fig. 573.-^ first four families a frontal suture, through which 



Pupanum of 7 & 



aMuscid. ^j^^ ptilinum is pushed out, when the adult is 

 about to emerge from the puparium (see page 419). 



Family Syrphid^ (Syr'phi-dae). 

 The Syrphus-flies, 



The family Syrphidae includes many of our common 

 flies ; but the different species vary so much in form that 

 no general description of their appearance can be given. 

 Many of them mimic hymenopterous insects ; thus some 

 species resemble bumblebees, others the honey-bee, and 

 still others wasps ; while some present but little resemblance 

 to any of these. 



