Bolma aureola

The colour is a uniform dull brick-red, except a brilliant cadmium-orange ring round the aperture.

The periphery is armed with short, broad, downwardly directed spines becoming obsolete towards the aperture.

Close spiral cords densely beset with imbricating scales cover the surface of the shell.

A narrow inner margin to the lip continuous with an axial callus pad is bright cadmium-orange.

Its nucleus is subterminal, hollow medially between two ribs, one of which rises proximally into a heavy callus mound.

Original drawing of a shell of Bolma aureola