Characters: Colonies are form solid plates or are massive, encrusting or columnar. Valleys are usually long and relatively straight at colony margins, becoming short, sinuous and contorted towards the colony centre. Walls are thin. Septa are highly irregular.
Colour: Red, grey, pale yellow or green, with valley walls and floors of contrasting colours.
Habitat: Rocky foreshores or shallow reef environments.
Abundance: Common only around mainland Japan.