XXV. FAMILY 



BY PROF. A. L. MKI^ANDER. 



Flies ranging in size from three-fourths of a millimeter 

 to fifteen millimeters, though rarely more than ten milli- 

 meters in length. Head more or less spherical, loosely 

 connected with the thorax. Males holoptic or dichoptic, 

 the front never excavated. Ocelli present. Antennae 

 porrect, approximated at their base, composed of two or 

 three simple joints; third joint variable in shape, with or 

 without a terminal style or arista, the latter rarely dor- 

 sal in position. Face without mystax, or fringe-like 

 row of bristles on the oral margin. Proboscis short or 

 long, usually rigid, projecting downward, forward or 

 backward. Thorax sometimes very convex. Male geni- 

 talia usually prominent and of complicated structure; 

 ovipositor simple. Squamae small. Legs usually slender, 

 often with structural peculiarities, such as the coxae or 

 femora lengthened, femora or tibiae thickened and spin- 

 ose, or with projections or fringes of scales, the metatarsi 

 flattened, etc. Pulvilli usually distinct ; enipodia usually 

 membranous and linear. Venation variable; discal cell 

 occasionally absent; the third longitudinal vein furcate 

 or not; three or four posterior cells present, anal cell 

 longer or shorter than the second basal cell, closed be- 

 fore the margin of the wing, sometimes wholly wanting.* 



The family Empididae is a large and complex one, in- 



* Hilarimorphan&& Mythicomyia(fig. 12, and figs. 25, 26 Bomby- 

 liidae) have been included in the Empididae. Both of these genera have 

 the anal cell narrowly open or closed in the border and are wholly 

 bristleless. The former germs will be found under the L,eptidae; the 

 latter is figured with the Bombyliidae. 



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