Corallum encrusting on old stock forming massive colony 12 x 8.3 cm across, 6 cm maximum height. Edge closely adhering, only very narrow strip free in some areas; epithecate. Surface evenly dotted all over with mostly nipple-shaped papillae, except near edge where some areas are smooth.

Calicles unequal, 0.5-1.0 mm across, flush; exclusively in valleys among papillae, several of them within a valley; most less than a half diameter apart. Calices circular or almost so; indistinctly or distinctly set off from coenenchyme, conspicuous. Septa thin. Primaries reaching half radius points or beyond; hardly convergent at bottom. Directives not always recognizable; when recognizable, slightly wider, may be lamellate. Secondaries very seldom present; as very tiny spines; cycle never complete.

Intercalicinal reticulum very distinct, meshes rounded, mostly wider than threads; spines fine, sharp pointed. Papillae mostly conical, or cylindrical, few elongated; average sized papillae 1.5 mm thick, 1.5 mm high; denser than coenenchyme; almost evenly disposed.

Remarks:This species resembles M. verrucosa in the arrangement and form of the papillae. But the size and arrangement of the calicles and the septal organization are quite different in the two.

Source:Nemenzo F (1967) Systematic studies on Philippine shallow water scleractinians: VI. Suborder Astrocoeniida (Montipora and Acropora). Part I - Text. Nat. Appli. Sci. Bull. 20 (1- 2): 1-141.