Up to 8mm long, 7mm high, 5.5mm across, oval-trangular, not skewed, umbones almost central, less plump than the proceding species, heavier for its size, more or less keeled.

Up to 8mm long, 7mm high, 5,5mm across, oval-triangular, somewhat inequilateral, skewed, slightly keeled.

Up to 6mm long, 5,5mm high, 4 mm wide, round, plump, fragile, almost equilateral, only very slightly keeled.

Shell up to 16mm long, 18mm high, 12mm across, plump, rhomboidal, with a distinct keel at the 7th or 8th rib from the posterior end. 20-24 flattened or rounded ribs.

Strong shell up to 2.5cm in length. The colour is variable including white, yellow, cream, brown or purple in vaious patterns. The sculpture is very variable. Early in life there are no ribs but can develop up to thirty later on and can can also develop to different extents.

Thin, fragile, shell up to 2cm in length. It is usually white, pink or red in colour. The surface of the right valve is relatively smooth while the left has numerous radiating ribs.

Fragile shell up to 2cm in length. The colour is variable and can include white, cream, pink, orange, brown and purple. The surface of the shell is smooth sculptured only with fine radiating and concentric lines.

Shell spindle shaped, robust in construction, 7-8 tumid whorls, up to 160mm. Mouth oval, about 60 % of height, siphonal canal short and open, lip reflected. Shell with fine growth and spiral lines, white to reddish colour, some adults with yellow internally. Some adult North Sea forms have a very flared lip.

Solid wedge shpaed shell up to about 10cm in length. The outside is purple, blue or brown in colour; the inside is pearl white bordered with purple or blue. The surface is sculptured with concentric rings.