Snails and limpets have a single coiled, one piece shell. New shell growth is on the outermost part of the coil. Some shells are round and flat and some are like a cone with a point.

Snails have a distinct head with a pair of tentacles, that extend and retreat. The eyes are at the base of the tentacles. They have round mouths with a row of teeth that are replaced as they wear down. Snails also have a tongue called a radula. Most snails feed on dead plants and animals.

Snails have a muscular foot with slime glands. The slime aids them while they crawl on their foot.

There are two main types of snails, those that have just gills and those that have lungs. The snails with gills are called Gilled Snails. The ones with lungs are called Pulmonate snails.

Pulmonate Snails

The most obvious observable physical difference between the two snails is the door like plate attached to the foot of the Pulmonate snails. This plate is called an operculum. There is one visible in the snail photo above. Apple snails and Columbian ramshorn snails are examples of snails with an operculum.

Pulmonate snails have lungs and can breath air at the surface. Some pulmonate snails can stay under water indefinitely breathing through their body surface.

Most of these snails lay eggs in jelly like cocoons. Winkles, another type of gilled snail, hold their eggs until they hatch. My Columbian ramshorns tend to like to lay their eggs in a gooey mass in p ...

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