DIPTERA. 463 



The head is not hollowed out between the eyes ; the 

 ocelli are present ; the antennae are furnished with a short, 

 simple style. Vein III is usually four-branched, but some- 

 times it is only three-branched ; all of the branches of vein 

 III end before the apex of the wing (Fig. 562); cell V 3 is 

 present, but closed by the coalescence of veins V 3 and VI^ 

 at the margin of the wing ; and cell V a is divided by a cross- 

 vein. The empodia are wanting. 



Family BOMBYLUDyE (Bom-by-li'i-dae). 

 The Bee- flies. 



These flies are mostly of medium size, some are small, 

 others are rather large. In some the 

 body is short and broad and densely 

 clothed with long, delicate hair (Fig. 563). 

 Other species resemble the horse-flies 

 somewhat in appearance, especially in the 

 dark color or markings of the wings ; but FlG - s^-—BombyUus. 

 these can be distinguished from the horse-flies by the form 

 of the antennae and the venation of the wings. 



The antennae are usually short ; they are three-jointed ; 

 the third segment is not ringed ; the style is sometimes 

 present and sometimes wanting. The ocelli are present. 

 The proboscis is sometimes very long and slender, and 

 sometimes short and furnished with fleshy lips at the ex- 

 tremity. 



Vein III of the wings (Fig. 564) is four-branched ; cell 

 III3 is sometimes divided by a cross-vein ; cell V 3 is obliter- 

 ated by the coalescence of veins V 3 and VII X ; in a few 

 genera cell V, is also obliterated by the coalescence of veins 

 V, and V 2 ; cell VIII is narrowly open, or is closed at or 

 near the border of the wing. The alulets are small or of 

 moderate size. 



The adult flies feed on nectar, and are found hovering 

 over blossoms, or resting on sunny paths, sticks or stones ; 

 they rarely alight on leaves. 



