Uniseriate and branched protonema produce protonemal flaps that produce perennial gametophytic shoots. Protonemal flaps are also produced in the Class Tetraphidopsida. The gametophore is small and has spirally arranged and costate leaves.
The sporangium is embedded in the perichaetial leaves, barely emerging because the seta is very short. Similar to Buxbaumiidae, the sporangium has an oblique surface. The peristome has an endostome with 16 pleats, while the exostome is rudimentary or absent.