Appearance
Alive, the snail appears bright orange-yellow in color with black markings. However, these colors are not in the shell, but are only due to live mantle tissue which usually covers the shell. The mantle flaps can be retracted, exposing the shell, but this usually happens only when the animal is attacked.
The shells reach on average 25–35 mm (0.98–1.38 in) of length, with a minimum size of 18 mm (0.71 in) and a maximum shell length of 45 mm (1.8 in).
The shape is usually elongated and the dorsum shows a thick transversal ridge. The dorsum surface is smooth and shiny and may be white or orange, with no markings at all except a longitudinal white or cream band. The base and the interior of a C. gibbosum shell is white or pinkish, with a wide aperture.

