Rhizotrochus Milne-Edwards & Haime, 1848a

Diagnosis.

Corallum ceratoid to turbinate or compressed. Transverse division absent. Pedicel small and not reinforced by stereome; however, two to twenty slender hollow rootlets anchor corallum base. Thecal spines absent. Three to six cycles of non-exsert septa, the lower septal cycle being usually highly concave near calicular edge. Pali absent. Columella rudimentary.

Type species.

Rhizotrochus typus Milne-Edwards & Haime, 1848, by monotypy.