Characters: Colonies are massive to encrusting, sometimes with laminar margins. Corallites have poorly defined walls but are separated by acute ridges so that each corallite or group of corallites is at the bottom of a neatly rounded excavation. Columellae are present and septo-costae are fine and even. Tentacles are rarely extended and only at night.
Colour: Pale or dark brown, sometimes yellow or green.
Habitat: Usually occurs on walls or under overhangs in clear water.
Abundance: Usually uncommon.
Identification Guides: Randall and Myers (1983); Veron (1986a); Sheppard and Sheppard (1991); Nishihira and Veron (1995); Pillay, Terashima, Venkatasami et al. (2002); Fenner (2005); Pichon, Benzoni, Chaineau et al. (2010); Turak and DeVantier (2011b);