Plants microscopic, annual or perennial from persistent protonema. Archegoniate plants composed of a perichaetium of a few, mainly non-chlorophyllose ecostate leaves that enclose very few archegonia. Antheridial plants reduced to a 1-stratose, 2-lipped structure enclosing a single spherical antheridium, arising from a short branch of the protonema. Seta elongate. Capsule usually obliquely oriented, upper face flat or bulging and often distinguished from lower face by a perimeter ridge, broadly ovate to lance-cylindric; operculum conic, nearly perpendicular to upper face of capsule; peristome with endostome 16-pleated, a hyaline cone, exostome of one or more rows of articulated teeth, irregular in number, sometimes rudimentary. Calyptra smooth, conic, barely covering operculum, early deciduous.