Corallum elongate, 15 cm long, 10 cm across its widest region; heavy. Lower surface very slightly concave, quite distinctly divisible into 3 concentric regions: the innermost, imperforate region, 7 x 4.5 cm, tubercles blunt and lamellate, seriate in some areas, all mixed up in others; intermediate region – very perforate, produced into a number of low, only slightly conspicuous humps, tubercles usually non-seriate, the short lamellate ones sometimes standing across the normal courses of the costae; and the narrow peripheral region, only slightly perforate, with conspicuous costae which are equal in height and thickness, edge granulate or cut into low tubercles which appear under low magnification as clumps of spherical granules (beaded).
Upper surface slightly convex, rather high along axial furrow; margin well rounded, around 25 mm thick; lobed. Axial furrow long, sinuous, very narrow, deep, 8.5 cm long.
Septa conspicuously unequal at medial portion, less so towards periphery; those of lower cycles thicker, their free margins cut into fine tubercles, clustered with granules especially towards axial furrow; surface with fine granulation of even height, those on the lower thin septa in between the higher ones coarser than those of the latter.
Columella inconspicuous, a tangle of digitiform projections from the septa visible at bottom of axial furrow.
