I've been enjoying G.Gudding's adventures in conchology. Here's an early poem by Mandelstam, trans. by Clarence Brown. Last line reminds me of the old song from Twelfth Night.

THE SEASHELL

Perhaps I am not necessary to you,
Night; out of the universal gulf
Like a shell without pearls
I am cast up on your shore.

You froth the waves indifferently
And obstinately sing.
But you will love and know the worth
Of the lie of the useless shell.

You will lie down on the sand beside it
Will cover it with your chasuble
You will bind to it inseparably
The enormous bell of the billows.

And the walls of the fragile shell,
Like the house of an empty heart,
You will fill with the whispers of foam,
With fog, wind and the rain. . .