The nature of things

Pointed sea-shells

AS the tide ebbs and dark stretches of reef appear, gulls forage for mussels and the inquisitive among us go rock-pooling, perhaps recalling the tongue-twister: She sells sea-shells on the sea-shore.

The shells she sells are sea-shells, I’m sure. For if she sells sea-shells on the sea-shore

Then I’m sure she sells sea-shore shells. The rhyme is said to recall the life of Mary Anning (1799–1847), an amateur palaeontologist who traded marine fossils she found at Lyme Regis, Dorset. So successful was she in locating not merely sea-shells, but entire skeletons of previously unknown animals (including near-complete plesiosaur remains) that her findings helped to steer scientific thought about prehistoric life on Earth.

But back to the sea-shells. Much more varied and commonplace (then and now) are the gastropods, creatures so well designed for their marine environment they’ve had little need to evolve down the scores of millions of years. For the rockpooler, the painted top shell (bottom, left and right) is an attractive find: a 1in-high sea snail of neat, cone shape, often with reddish marks delineating the spiral rings. Slender and discreetly sandy-coloured needle whelks (top right), less than half an inch long, are perfect miniature cornettos and the common wentletrap, up to 11∕2in, has a beautiful, ribbed, spiral-staircase shell in pale grey to white (top left). KBH