The gastropod shell is part of the body of a gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or the shell is reduced such that the body cannot be retracted within (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. An excellent source for terminology of the gastropod shell is "How to Know the Eastern Land Snails" by John B. Burch now freely available at the Hathi Trust Digital Library.
The columella or pillar is a central anatomical feature of a coiled snail shell, a gastropod shell. The columella is often only clearly visible as a structure when the shell is broken, sliced in half vertically, or viewed as an X-ray image.
Pleurotomariidae, common name the "slit snails", is a family of large marine gastropods in the superfamily Pleurotomarioidea of the subclass Vetigastropoda. This family is a very ancient lineage; there were numerous species in the geological past. The genus includes several hundred fossil forms, mostly Paleozoic. It is one of the oldest gastropod families, commencing in the Cambrian.
Vetigastropoda is a major taxonomic group of sea snails, marine gastropod mollusks that form a very ancient lineage. Taxonomically the Vetigastropoda are sometimes treated as an order, although they are treated as an unranked clade in Bouchet and Rocroi, 2005.
Sukashitrochus morleti is a species of minute sea snail, a marine gastropod mollusk in the family Scissurellidae.
Danilia telebathia is a species of small sea snail, a marine gastropod mollusk in the family Chilodontidae.
Turbo heterocheilus is a species of sea snail, marine gastropod mollusk in the family Turbinidae.
Microgaza is a genus of sea snails, marine gastropod mollusks in the family Solariellidae.
Calliotropis tiara is a species of sea snail, a marine gastropod mollusk in the family Eucyclidae.
Spectamen philippense is a species of small sea snail, a marine gastropod mollusk in the family Solariellidae.
Callogaza watsoni is a species of sea snail, a marine gastropod mollusk in the family Margaritidae.
Clanculus guineensis is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.
Gaza superba, common name the superb gaza, is a species of deep sea sea snail, a marine gastropod mollusk in the family Gazidae, the top snails.
Trochus maculatus, common name the maculated top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.
Callogaza is a genus of sea snails, marine gastropod mollusks in the family Margaritidae.
Phanerolepida transenna is a rare species of sea snail, a marine gastropod mollusk in the family Turbinidae, the turban snails.
Clanculus johnstoni is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.
Coelotrochus viridis, common name the green top shell, is a species of sea snail, a marine gastropod mollusk in the family Trochidae, the top snails.
Gaza daedala is a species of sea snail, a marine gastropod mollusk in the family Margaritidae.
Halystina umberlee is a species of very small deep-water sea snail, a marine gastropod mollusc in the family Seguenziidae.
