XX. FAMILY MYDAID^. 







Rather large to very large (see fig. i, page 16), thinly 

 clothed or bare, elongated flies. Venation complicated, 

 the basal cells long, the fourth vein always terminating 

 at or before the tip of the wing ; posterior branch of 

 fourth sometimes present and terminating also before the 

 tip of the wing, as in Rhaphiomidas ( Apioceridae), but 

 not present in American species. Antennae composed of 

 four joints, the fourth always, the third usually elongate. 

 Front excavated between the eyes; both sexes dichoptic; 

 ocelli wanting. Proboscis with fleshy labella, and with- 

 out palpi (in our species). Kmpodia very little devel- 

 oped, not pulvilliform. 



Fig. 72. Mydaidae. i, Dolichogaster, wing; 2, Dolichogaster, 

 antenna ; 3, Mydas, antenna. 



The family Mydaidae comprises only about a hundred 

 known species, more abundantly represented in Austra- 

 lia, Africa, South and Central America. The family 



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