Scallops

Family Pectinidae. A large and popular family, both as collectors' items and as food. The genera are very complex and the divisions are arbitrary. Amateur collectors may call them all Pecten. Many species are capable of swimming by snapping their valves. Most species are tropical, but a few live in polar waters. Sculpture differs on opposite valves.

Conchs

Family Strombidae. Includes several genera differing widely among themselves in shell features, but allied anatomically. Most shells have a "stromboid notch" near anterior end. Are herbivorous and make leaping movements using strong, horny, curved operculum. Eggs are laid in long gelatinous strands.

Helmets & Bonnets

Family Cassidae. Shells live mostly in warm waters around the world. Shells of males may differ from females. Interspecies hybridisation may take place and deep water forms are particularly puzzling. Some species spawn tower-like egg masses and free swimming larval stages. Food consists primarily of sea urchins. Operculum chitinous, small, elongate in Cassis, fan shaped in Phalium.

Augers

Family Terebridae. Large family of long slender shells with many whorls. Smooth or ornamented, often highly coloured, they differ from turret shells by having short anterior canal and narrow aperture. Thin operculum is placed on small foot. Radula with one or two teeth. Sand dwelling carnivores of warm waters.

Similar.

Family Turritellidae. A worldwide abundant group of sandy mud snails found off-shore. Operculum chitinous, many whorls, sometimes with bristles on edge. Several hundred species. Mostly tropical. Different shape aperture from Terebridae.

Turbans

Family Turbinidae. This is a large family of top-shaped shells, usually with thick shells, an iridescent interior, and usually with a shelly operculum that seals the aperture. Several hundred species are known, most from tropical seas. Most species are vegetarians feeding on marine algae.

Figs

Family Ficidae. Small family of moderately large to small shells, characteristically fig or pear-shaped and light in structure. Sand dwellers in warm water areas, they lack an operculum. The large foot has two flaps, one on each side of the anterior (siphonal) end. Shells of males may differ from those of females.

Ceriths

20:10

Family Cerithiidae. The ceriths are a family of mainly shallow water dwellers, most distributed in the tropics. They live in large colonies feeding on mud detritus and decayed algae. Operculum horny.

Wentletraps

Family Epitoniidae. The wentletraps are popular collector's items because of their intricate ribbing. The 200 or so known species live in all seas from shallow to very deep waters. Some feed on sea anemones.