Deltocyathus magnificus Moseley 1876

New Caledonia, 464-480 m (Kitahara & Cairns, 2009); east China sea, 88-422 m (Cairns 1994); western Pacific from Japan to southeastern Australia, 88-1500 m (Cairns & Zibrowius 1997); including Vanuatu region, 408-433 m (Cairns 1999); Sulu Archipelago, Moluccas, 118-1500 m; Philippines, Indonesia, 8-522 m (Cairns & Parker 1992); western Australia, 250 m (Cairns 2004).

Corallum discoidal to hexagonal with a slightly concave base. Costae equal thin ridges, finely dentate, being separated by wide furrows and extending up to 1 mm beyond calicular margin. C3-5 not present at centre of base. All costae laterally spinose especially near calicular edge, where intercostal furrows are deeper. Corallum white. Septa hexamerally arranged in 5 cycles (S1≥S2>S3>S4-5), but any specimen examined display a complete fifth cycle, denoting their juvenil stage. S1 only independent septa, 6 mm exsert, joining columella through a wide palus that sometimes are divided at the upper margin in 3 paliform lobes. S2 equal to slightly less wide than S1, also joining columella through a wide and tall pali. S3 4/5 width of S3, less exsert and bear a paliform lobe that fuses to P2 near columella. S4 half size of S3 and less exsert, joining P3 through a typical deltocyathid chevron arrangement. S5 less exsert but equal in width to S4, also bearing a paliform lobe that fuse P4. Fossa very shallow, aligned with the 2 principal and opposite S1, containing a papillose columella variable in size, shape, and number of rods.