DIPTERA. 



457 



genera the third segment consists of several subseg- 

 ments, which may be quite distinct (Fig. 548); in others the 

 antennae are only three-jointed, and the third segment bears 

 a style or bristle (Fig. 549). The proboscis is usually short, 

 only a few members of the family having it long like the 

 bill of a snipe. The wings are broad, and when at rest are 

 held half open. The empodia are pulvilliform ; that is, 



Fig. 548.— Antenna of Xylo- Fig. 549.— Antenna 

 phagus and, p, palpus. of Chrysopilu.. 



Fig. 550. 



there are three, nearly equal, membranous pads beneath the 

 tarsal claws (Fig. 550). 



Although the form of the antennae in certain genera 

 closely resembles that characteristic of the long-horned flies 

 (Nematocera), the form of the palpus even in these cases 

 (Fig. 548, /) is that characteristic of the short-horned flies 

 (Brachycera), being only two-jointed and not pendulous. 



The venation of the wings is comparatively generalized 

 (Figs. 551, 552), each of the principal veins usually extend- 

 ing distinct from the others; but in some veins VII, and IX 

 coalesce at the margin of the wing (Fig. 552). Vein III is 

 four-branched ; the branches of vein V are connected with 

 adjacent veins only by cross-veins ; and cell V a is divided by 

 a cross-vein. 



The flies are predaceous. They may be found about 

 low bushes and on tall grass. They are somewhat sluggish, 

 and, therefore, easily caught. 



The larvae also are predaceous. Some live in earth, 



