Stereoderma

Ayres, 1954

5 species

Ten tentacles. Calcareous ring simple, without forked tail. (Panning, 1949)

ten tentacles, mouth terminal often star shaped. Anus terminal or sub-dorsal. Feet restricted to the radii but encroaching on the interradials. Anal teeth well developed or reduced. Calcareous ring without posterior prolongations. Spicules: nodulary buttons, massive plaques prenant parfoid la forme de cone de sapin; no tables, no etc. (Cherbonnier, 1951)

Shaped as pentagonal cucumber, with feet limited to radii. 10 tentacles ventral two smaller. Calcareous ring simple without prolongations. Spicules form butons and nodulary plaques, no crepus nor tourelles. Cherbonnier, 1957). (Cherbonnier, 1957 & Panning, 1964)

Tentacles 10; two ventral smaller. Pedicels scattered irregularly over the body but tending to form regular double row over part of the trivium. Integument hard. Anus without teeth. Calcareous ring of 10 simple pieces without posterior prolongations. Numerous crowded buttons with 4 holes. Pedicels without terminal plate. (HBF)