Subclass Diphysciidae has historically been grouped with species of Buxbaumiidae. However, despite superficial similarities, these groups are not closely related.
The protonema is uniseriate and branched, producing protonemal flaps that give rise to perennial gametophytic shoots. (Protonemal flaps are also seen in the Class Tetraphidopsida.) The gametophore is relatively small, with spirally arranged, costate leaves.
The sporangium is largely embedded in the perichaetial leaves, barely emerging because the seta is very short. Similar to Buxbaumiidae, the sporangium exhibits an oblique capsule surface. The peristome is reduced: the endostome has 16 pleats, while the exostome is rudimentary or absent, reflecting the simplified sporophyte morphology characteristic of this subclass.