Within the most diverse family of azooxanthellate corals, the Caryophylliidae Dana, 1846, the genus Deltocyathus Milne Edwards & Haime, 1848, which is common worldwide and consists of 25 Recent valid species, is characterized by having: a free, discoidal to patellate, solitary corallum in the adult state; well developed costate septotheca; pali before all but last cycle of septa; P3 fusing P2 near the columella, forming chevrons (or deltas); paliforme lobes sometime present before the last cycle; and a papillose columella.