These mayflies are of medium to large size, ranging from 10 to 32 mm. They possess upturned mandibular tusks and a frontal process between the antennae. The fore legs are modified and widened for burrowing purposes. Gills are present on segments 1-7, with small (vestigial) and simple gills on segment 1, and forked gills with fringed margins (feathered) on segments 2-7, which are held over the abdomen.