Shell subquadrate, the anterior side being undeveloped, causing it to be inequilateral, much inflated, solid. Colour white (possibly bleached). Sculpture: thirty-two concentric furrows traverse about forty-eight radii, of which fifteen are anterior and twelve posterior; on each of the resulting facets is set an elevated bead. The beads are conical, half imbedded on the long axis, the apex directed to the umbo, the base overhanging the furrow. They gradually increase in size to the margin. Prodissoconch large and conspicuous, with two rims set some distance apart; the inner basin is shallow triangular, its centre occupied by a prominent spike. Hinge : the ligament set obliquely between two crenulated areas. Under the anterior crenulation a single massive cardinal and socket, below and behind the posterior crenulation three laterals. Height 3 mm.; length 1,85 mm.; depth of single valve 0,9 mm.

The occurrence of a Cratis in the coral fauna was unexpected. C. recapitala belongs to a group of radiate, inflated asymmetrical species of which the New Zealand P. costata was the first known. The exquisite sculpture will readily distinguish the present species, whose individuality is further marked in the hinge and complicated prodissoconch. The median spike of the latter presents inferences of wide interest. The hollows on the summits of the prodissoconch caps of certain species, for example, Condylocardia concentrica Bernard, and Philobrya parallelogramma may, it is now suggested, be the scars from which similar spikes have been shed. Such a spike appears on the prodissoconch of Cyclopecten obliquus.