Order:
Wings developing in wing pads. Mouthparts suitable for chewing. Gills present on tops and sides of abdomen. Segmented legs present. One tarsal claw per leg. Usually with 3 tails (sometimes 2).
Family:
Labrum usually with median notch and antennae usually long (at least two or three times the width of the head). If median notch absent, then antennae long; if antennae shorter, then distal margin of the labrum always notched. Claws of all legs similarly shaped, usually pointed, rarely broad at the apex; claws of varying lengths, if claws of middle and hind legs long and slender, they are usually shorter than tibiae, except for few rare genera. Abdominal gills roughly oval or heart-shaped. Gill lamellae either single, double, or triple folded; rarely with fringe on inner margins, never with terminal filaments or pointed ends. Mature larvae 3-12 mm long.