Corallum thin, explanate, encrusting on dead coralline rock; 1 mm thin at edge. Upper surface undulate.
Corallite small, slightly protruding (up to 1 mm), cylindrical or slightly truncate-conical; unevenly distributed (up to 5 mm distant from center to center). Calice shallow, 1 mm across; fossa funnel-shaped; wall relatively thick.
Septa 20: 10 reaching columella alternating with 10 or less narrow ones, merely ridges on inner surface of wall. Principal ones equal in thickness (thinner than loculi), equally exsert over wall, equally spiny, exsert portion not inflated, subentire; edges bear small dentations, taller toward columella than away from it; surface covered with prominent blunt spinules. Alternating septa thinner and less exsert than principal ones.
Costae very slightly thicker than corresponding septa, bearing similar spinules; not extending to peritheca.
Columella a depressed area, about one-fourth of calicinal diameter, not well organized, 1-3 tubercles may stand out.
Peritheca looks dense but for scattered patches surfaced with closed vesicles especially within depressions ad around corallites. Perithecal spines quite low, frosted, resembling clusters of granules, numerous, non-seriate.
The small, distant corallites easily distinguish this species. It resembles C. micropthalma in number of septa.
