Petaloconchus sp. - "worm snails" (modern) from the Bahamas. (collected March 1992)

The gastropods (snails & slugs) are a group of molluscs that occupy marine, freshwater, and terrestrial environments. Most gastropods have a calcareous external shell (the snails). Some lack a shell completely, or have reduced internal shells (the slugs & sea slugs & pteropods). Most members of the Gastropoda are marine. Most marine snails are herbivores (algae grazers) or predators/carnivores.

The unusual, squiggly mass seen here is a compact colony of vermetid snail shells. Vermetids are nicknamed "worm shells" or "worm snails" because their shells are highly irregular in shape. Vermetids are filter-feeding, hard-substrate encrusters. They often encrust their shells together into small, reef-like structures.

Classification: Animalia, Mollusca, Gastropoda, Vermetidae

Locality: loose piece on beach, northern shoreline of San Salvador Island, eastern Bahamas

See info. at: <a href="https://en.wikipedia.org/wiki/Petaloconchus" rel="noreferrer nofollow">en.wikipedia.org/wiki/Petaloconchus</a> and