Colonies are thin delicate laminae with widely but uniformly spaced corallites. Corallites are well defined, becoming immersed, with indistinct walls. Septo-costae form parallel striations irrespective of the position of corallites. Most septa radiate from the corallite centre, but those adjoined to costae remain aligned with the costae. Septo-costae inside corallites are in three indistinct orders. Columellae consist of a few septal spines or are absent.