To analyze the external anatomy of snails, we will divide their body into the shell and the soft body that holds it. The former is a solid spiral-shaped structure carried on the back, made of a single piece and consisting mostly of calcium carbonate. The central layer of the shell, called ostracism, has two layers of crystals of the same substance, calcium carbonate. The Hipostracum is below, and the most superficial layer is the periostracum, composed of a lot of proteins.
The shell of a land snail can be very different in size and shape depending on the species. Some of them are cone-shaped while others are round. However, all of them have a spiral design, caused by the way land snails produce and growth their shells.
This structure protects the snail from the environment and even from predators. It is made up of calcium carbonate which makes it strong and remains that way as long as the snail consumes food with calcium.
Its surface can show different colors with fringe designs, but they usually are brown or yellow. The shell protects the body and internal organs of the animal and has an opening to one side, usually the right.
