Flabellum Lesson, 1831

Diagnosis.

Corallum solitary; attached or free. Corallum shaped in a variety of ways, including ceratoid, campanulate, bowl-shaped, discoidal, or compressed-flabellate. Transverse division lacking. Base and lower pedicel not reinforced with stereome. Wall epithecal, usually porcelaneous, without costae. Pali, dissepiments, and synapticulae absent. Columella rudimentary to absent, when present a simple fusion of lower axial margin of larger septa. Exclusively azooxanthellate.