[3] Solitary rugosans (e.g., Caninia, Lophophyllidium, Neozaphrentis, Streptelasma) are often referred to as horn corals because of a unique horn-shaped chamber with a wrinkled, or rugose, wall.

When radiating septa were present, they were usually in multiples of four, hence Tetracorallia in contrast to modern Hexacorallia, colonial polyps generally with sixfold symmetry.

[4][5] Although there is no direct proof, it is inferred that these Palaeozoic corals possessed stinging cells to capture prey.

Rugose corals always show tabulae, horizontal plates that divide the corallite skeleton.

Rugose corals will also always have a columella, an axial rod which supports the septa running up the center of the corallite.