Families: Orthodontiaceae.
Botany: Acrocarpous (not Hymenodon). Central strand +. Costa + Aut-, par-, or dioicous, rarely heteroicous. Seta + CAP erect to horizontal, often furrowed, stomata phaneropore Annulus –. Operculum +. PS reduced, cilia –. Spores ± papillose CY cucullate. Axillary propagules or rhizoidal gemmae