Medusa: umbrella with coronal groove on upper surface; margin cleft into stout lappets with thick mesoglea; tentacles solid, situated in the clefts, appearing away from edge of bell but in fact peripheral; stomach wall joined to subumbrella by four gastric septa; mouth-opening single, with undivided lips. Exumbrella radially thickened between coronal groove and marginal lappets (pedalia).
Polypoid stage: those known having Stephanoscyphus form, strobilating ephyrae which develop into adults. Atorella subglobosa might be expected in the South Atlantic, but has not yet been reported.
[After Kramp (1961); Larson (1986); Werner (1984)]