Salty sea treasure

Another combination of two challenges, salty for the Dutch challenge (zilt) and a macro of the shell for Tiny Tuesday with thanks to osuzanna for hosting this month. And a bit of extra editing to emphasise the marks on the shells, I think these may be keel worm tubes.

Thought of this song while thinking about the salty assignment.

Thanks very much for the kind comments, stars and even hearts for yesterday's bored selfie :-) One day I'll try a smiley one ;-)