Order:
Larval wings/wing pads absent. Eye spots present, but compound eyes absent. Segmented legs present on thorax. Abdominal segment 9 with either one slender tail or pair of anal prolegs, each with two hooks. Seven or eight pairs of filaments or gills laterally on abdomen, with never more than one pair per segment.
Family:
The mouthparts are slender, needle-like; the antennae are long and conspicuous from dorsal view; the wing membrane has 4 or 5 distinct, similar cells defined by thicker veins; found beside the water and not in it.
