Also called Marsh Snails, Periwinkles are most often found crawling on marsh grass in warm months, measuring one inch or less in diameter. Their shells are spiral in shape with circular grooves covering the shell, which is usually gray to white in color but can be covered with green algal slime. The body of this snail consists of a head with two tentacles, an eye at the base of each tentacle, and a proboscis between the tentacles. These herbivores are dependent on brackish water and therefore are only found in saltmarsh habitats where they feed primarily on algae, which they scrape off with their radulas. Their radula has up to 300 rows of teeth, which are constantly being worn down and replaced at a rate of five to six rows each day. Periwinkles are eaten by many shorebirds and by man, known as escargot, which means edible snail in French. Periwinkles should be not confused with Mudsnails.