Columbarium rotundum Barnard, 1959 Coluzea rotunda is a species of large sea snail, a marine gastropod mollusk in the family Columbariidae.

[2] The shell is relatively thin, with a long, slender, and straight siphonal canal.

The rest of the shell is sculpted with rounded axial ribs intersected by spiral cords, which are most prominent below the periphery.

[2] The shell is uniformly white, covered by a pale khaki-brown periostracum.

[2] This marine species is endemic to South Africa and occurs off the west coast, off Atlantic Cape region (Alexander Bay to Cape Point), at depths between 200 m and 400 m. [2]