Lhe Robber Flies, 417 
much resembles that of the genus Promachus, though the 
form of these insects is very different. 
In Mallophora and Promachus the venation is as repre- 
sented in Fig. 202, where, as will be seen, the second vein 
(Fig. 202, 4) forks, while in the genus Asilus (Fig. 196) 
Fig. 202. 
the third vein is forked, though in all three genera the 
third joint of the antenne (Fig. 200) ends in a prolonged 
bristle. 
One of the most common of these pests, which I am 
informed by Dr. Hagen is Mallaphora orcina, Weid., is 
Fic. 203. 
ene inch long, and expands one and three-fourths inches 
(Fig. 203). The head (Fig. 200) is broad, the eyes black 
and prominent, the antenne three-jointed, the last joint 
terminating in a bristle, while the beak is very large, 
strong, and, like the eyes and antenne, coal black. This 
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