Fauré-Fremiet, 1961
Body often elongate, sometimes very drawn out posteriorly. Ventral cirri generally small and quite inconspicuous (occasionally as few as 2-3 cilia per cirrus) and typically arranged in 3-12 longitudinal (sometimes spiralled) rows. Marginal cirri common, transverse cirri sometimes absent. Stomatogenesis parakinetal in primitive forms. Several species produce loricae, a few of these forming colonies. Free-living in diverse habitats, also ectocommensal.
Family Urostylidae