Rather small flies, rarely more than 6 mm in length, the auxiliary vein entire and ending in the costa.
Head variable, the face projecting or retreating, convex, flat or concave, without oral vibrissa although these are rarely poorly developed. Front wide, with two pairs of frontals, the upper pair always reclinate, the lower pair sometimes decussate; ocellars present or minute. Antennae variable, the arista plumose to bare. Thorax with bristles, at least behind the suture; scutellum usually bare except for the marginal bristles; propleural bristle present or absent; one or two sternopleurals. Tibiae all with preapical bristle. Wing venation complete, the second basal and anal cells short; apical cell usually widely open. Abdomen oval, rarely elongate.
Rather small flies, rarely more than 6 mm in length, the auxiliary vein entire and ending in the costa.
The adults may be found almost everywhere, but particularly in moist places where they may occur in large numbers. Many of the species are more in evidence in the evening than during the rest of the day. They are not very active and are therefore easily captured.
The larvae of at least some of the species mine in plants and are economically important; others live upon decaying vegetation.
