Characteristics of the Family (from Kramp 1961)

Semaeostomeae in which the central stomach gives rise to radiating pouches with in turn give rise to numerous branching, blind canals in the marginal lappets; without a ring-canal; with gonads in complexly folded, interradial eversions of the wall of the subumbrella; with tentacles arising from the subumbrella at some distance from the margin.