This model of a Shark's Eye snail in a display at the Shell Musem shows what the living animal looks like. It is amazing that so much animal can fit into the little shell! Shark's Eyes and Moon Snails use their sharp radula (tongue) to rasp a round hole in the shells of bivalves (and sometimes other gastropods) to eat the animal in side.
I was fascinated by these strange lines in the sand as I was walking on the beach early one morning. When I investigated more closely, I noticed a tiny Dwarf Olive snail working its way over the sand in search of food.