Outer surface of the jellyCartilaginous margin of the like disk; six of these are disk covered by thread perradial, six interradial, cells.
Primitively there are four perradial tentacles, to which may be added four interradial, or they may become very numerous and are then scattered evenly round the margin, never arranged in tufts or clusters.
66) with more than eight tentacles; Cunoctantha with eight tentacles, four perradial, four interradial.
Ra, Tentaculocysts, four perradial, four interradial.
- Surface view of the Subumbrella or oral aspect of Aurelia aurita, to show the position of the openings of the subgenital pits, GP. In the centre is the mouth, with four perradial arms corresponding to its angles (compare fig.