Originally published December 3, 2008
Nerites are small snails that live in various habitats, some salt water and some in brackish fresh water. They have a lid made of cancerous material that they can close to protect them from predators. And they are beautiful, with stripes, spots, and zigzags on their shells. They feed on algae and the discarded plant material and so help clean the environment.
In these shells notice how some patterns twirl smoothly around the shell while others seem to have jumped a line, as though the growth had been interrupted.