Cormus massive, formed of thin, regular and tightly anastomosed tubes.

Oscula are simple openings, surrounded by a thin membrane, and located on the top of short conical projections.

The apical actine of the tetractines is shorter and thinner than the facial ones, and it is conical, sharp and covered with short spines.

However, it is possible to distinguish them from large triactines because of the strong conical shape of their actines and because of their location.

[1] World Register of Marine Species This article about a calcareous sponge is a stub.