Colonies are free-living and elongate, with an axial furrow that may become indistinct. Colonies are occasionally Y, T or X shaped. Centres are evenly distributed over the upper surface. Primary septa are short and elliptical or petaloid. Secondary septa usually fuse around the primaries to form a background matrix. Tentacles are usually extended during the day; they are long and numerous.
Grey, greenish or cream, with white tentacle tips.
Reef slopes, especially where Fungia is common.