470 
THE STUDY OF INSECTS . 
VII, coalesces with vein V s , as shown in the figure; but 
in the males the tip of vein VII, 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 little 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 
Puparmm~of ^ rst f° ur f aiT nli cs a frontal suture, through which 
a Muscid. tj ie ptilinum is pushed out, when the adult is 
about to emerge from the puparium (see page 419). 
Family SYRPMIDA£ (Syr'phi-dae). 
The Syrphus-Jlies. 
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. 
