General description:
Frontal shield evenly perforated, or with marginal areolae only. Primary orifice with lyrula and/or condyles; peristome typically well developed, with or without oral spines. Ovicell prominent, perforate or imperforate, not closed by zooidal operculum. Pore-chambers or septula present. Avicularia adventitious only; suboral, or lateral to the orifice.
(Hayward and Ryland, 1999)
Taxonomic name: