Bell transparent, dome-shaped, with prominent coronal groove; up to 7.5 cm in diameter, exumbrella with nematocyst warts, mesoglea fairly thick. Pedalia 16. Marginal lappets 16, rounded. Rhopalia 4, perradial. Tentacles 12, 3 between each rhopalium and next, 2/3 length of bell. Subumbrellar coronal muscle continuous, prominent. Stomach attached to subumbrella by 4 interadial gastric septa, forming 4 pockets that separate subumbrella from manubrium. Phacelli 8, each with ca. 20 gastric filaments. Perradial ostia 4, connecting stomach with gastrovascular sinus; distally divided by 16 centrifugal septa. Manubrium with 4 mesogleal perradial reinforcements and crenate margin. Gonads 8, W-shaped.
Color of stomach deep chocolate-red, rest colorless.
(After Russell, 1970).