(Haeckel, 1869)
Large, hemispherical, little known. Bell massive, flexible but firm; recorded to 65 cm; surface smooth, except for shallow forking grooves in peripheral ca. 1/6 (?) of radius. Marginal lappets up to 8 per octant, triangular, plus 2 narrow rhopalar lappets approximately same length; rhopalia 8. Mouth-arms 8, approximately as long as bell diameter, mouthlets on distal 3/4; tapering neatly to somewhat pointed end; without filaments or clubs. Gonads rimming the cross-shaped stomach.
Color: recorded with exumbrella bluish-white through off-white to pale cream, also brown; peripheral exumbrellar grooves reported "reddish or brownish purple"; gonads outlining stomach-cross once reported red.
(Mainly after Mayer, 1910).