In extreme crowding, individuals in columnar groups may have an aperture greater than their base, resulting in a trumpet form. Neighbours of this one have died and been eroded away. North Wirral coast, Cheshire.
In extreme crowding, individuals in columnar groups may have an aperture greater than their base, resulting in a trumpet form. Neighbours of this one have died and been eroded away. North Wirral coast, Cheshire.