168 THE GAD- OR BREEZE-FLIES. 
we know. In our southern counties the ‘‘Green-head”’ 
( Zabanus lineola Fab.) has a very bad reputation and further 
south in the Mississippi valley it is sometimes impossible to 
work horses in midsummer without a protecting covering. In 
fact cases are on record that horses fastened to a tree ora 
fence were bitten to death. This fly is illustrated in fig. 138. 

Fig. 138.—Green-head. Greatly enlarged. Original. 
“The Black Breeze-fly”’ ( Tabanus atratus Fab.), though found 
in Minnesota, is not common, hence causes less trouble to 
cattle, whichit prefers to horses. Itslargelarva is found under 
stones in water, where it feeds upon other aquatic animals. 
The most common of oyr breeze-flies is illustrated in fis’ 139, 
plate XIII. Itis “Reinwardt’s Breeze-Ay”’ ( Tabanusreinwardtii 
Wied.). This fly, less blood-thirsty than the two mentioned 
above, is found in immense numbers in our prairie region. 
It sometimes gathers in the small railway stations in such 
numbers onjthe window-panes that no light can fallthrough 
them, and the writer counted upon one window, and below 
it upon the bench, the astonishing number of 2117 flies. 
Why they should remain and die in such places is difficult to 
explain; at all events these rooms acted as traps, and the 
flies had not sense enough to escape by the open.door, but 
battered their heads against the glass in their vain efforts 
to force their way out. The larger breeze-or gad-flies attack 
only larger domesticated animals, such as horses and cattle. 
The genus Chrysops is distinguished from Zubanus by posses- 
sing three simple eyes, which are readily seen on the top of 
the head. The scientific name is derived from the beautiful 
golden-yellow eyes, with purple lines and spots, which these 
