DIP TER A. 473 
Professor Williston describes about three hundred species 
irom this region.* 
Family PlPUNCULlD^E (Pip-un-cu'li-dae). 
The Big-eyed Flies . 
This family is represented in the United States by a 
single genus, Pipunculus (Pi-pun'cu-lus). These are small flies, 
with very large heads composed almost en¬ 
tirely of eyes (Fig. 577). The head is nearly 
spherical, and broader than the thorax. The 
abdomen is somewhat elongate with the sides 
nearly parallel. The body is thinly clothed 
with hair or nearly naked. The wings are fig . 577 . -Pij>un- 
much longer than the abdomen, and when at 
rest they lie parallel to each other upon it. The venation 
(Fig. 578) closely resembles that of some of the Conopidae. 
Vein III is three-branched. The last branch of Vein III and 
the first branch of vein V approach each other at their tips. 
Vein V 3 coalesces with vein VII, for nearly its entire length. 
Veins VII a and IX coalesce at their tips. Cells III and V 
are long. 
The flies hover in shady places. They are sometimes 
found on flowers, and may be swept from low plants; our 
most common species measure about one eighth of an inch 
in length, not including the wings. The larvae so far as 
known are parasitic upon bugs. 
* Bulletin of the U. S. National Museum, No. 31. 
