Shell large to very large, elongate, with a tail spire and short anterior canal and base. Sculpture dominantly spiral, of low cords with one or several interstitial threads, or of threads only; axial sculpture consisting of low, week folds in a narrow band below the suture and of several peripheral and lower rows of knobs. Varices developed, spaced ahout every 270º around the shell, merging into the shell abaperturally but prominent adaperturallv and bearing the remains of the flaring outer lip in front. Inner lip rather broad bearing one or two callus ridges near the posterior canal and sculptured below with irregular plicae that are often developed on the top of anterior canal only. Colour cream, pink or fawn marbled with darker reddish brown splashes. Protoconch of five smooth, rounded whorls, rather short and turbinate, with a brown, horny outer layer and a thin, pink, shelly inner layer, usually missing in adults, Periostracum or teleoconch very thin, pale straw coloured, smooth or lightly wrinkled, readily deciduous, perhaps even totally absent in C. tritoni. Operculum thick, dark brown, oval with a central nucleus and complete concentric growth lines in C. tritonis, oval with a slight anterior hook on the left, and anterior subterminal nucleus and incomplete concentric growth lines in C. lampas. Radula highly distinctive; of typical taenioglossan type, but with the central tooth broad and low, with a very narrow basal plate that is curved down at the extremities. All other teeth narrow and elongate.
The most distinctive feature of the genus is its radula, but it can also be readily separated from other Cymatiidae by its very large size, the form of the varices and the reduced periostracum.