(Quoy and Gaimard, 1827)
With longitudinal exumbrellar cnidocyst ribs; marginal tentacle bulbs laterally compressed. Umbrella up to 10 mm wide and 21 (sometimes up to 30 mm) high, with rounded or conical apex, topped with a peculiar opaque ectodermal thickening; mesoglea fairly thick; with 16-24 longitudinal exumbrellar cnidocyst ribs originating from each tentacular bulb; manubrium about half as long as bell cavity; with short mouth tube and very folded lips; radial canals fairly narrow, smooth; mesenteries about 4/5 of manubrium length; with 16-24 (sometimes up to 44) marginal tentacles, with conical, laterally compressed bulbs, but devoid of well-developed abaxial spurs; gonads on entire interradial walls of manubrium, forming coarse-meshed network of ridges with pits in between; with ocelli.