Characters: Colonies are phaceloid, rarely subplocoid. Corallites are 9-14 millimetres diameter. Septa are not arranged in cycles and are numerous. They have small blunt teeth. Mantles, but not tentacles, are extended during the day and may form a continuous surface obscuring the underlying growth-form. Colour: Mantles are usually dark grey, but may be red or green. Oral discs are usually green but may be red or dark grey. Similar species: Blastomussa merleti. See also the euphyllid Nemenzophyllia turbida and the faviid Montastrea multipunctata, both of which have fleshy mantles. Habitat: Lower reef slopes protected from wave action, and turbid environments. Abundance: Uncommon, rare in the Red Sea.