Colonies are encrusting, multiserial and sheet-like, often quite large in size. The apparent ancestrula is ascophoran, identical to zooids from later astogeny but smaller, about 0.36 mm long by 0.28 mm wide, and buds one distal and two distolateral zooids.
Autozooids are slightly elongate, rounded-rhomboidal in outline shape, moderately large, about 0.54-0.65 mm long by 0.35-0.46 mm wide in colonies from the Coralline Crag (cf. Recent material for which Zabala et al. 1993 quoted measurements of 0.48-0.76 mm long by 0.43-0.65 mm wide). The frontal shield is convex, finely granular and lacks pseudopores but is pierced marginally by small, subcircular areolar pores, usually arranged in a single row but sometimes with additional pores at the proximal end of the zooid. The primary orifice is wider than long, about 0.11 mm long by 0.15 mm wide, has two strong condyles close to the proximolateral corners, and contains a low, concave lyrula, often partly hidden by the prominent, acute umbo. Oral spines are invariably 6 in number. Zooid basal walls contain an uncalcified window. The ovicell is recumbent on the distal zooid, small, about 0.15 mm long by 0.25 mm wide, and has an imperforate, granular ectooecial surface.
Avicularia are lacking.
Kenozooids are occasionally present. They are sealed by a convex, cryptocystal wall that is granular and contains multiple rows of peripheral areolar pores.