The eastern whorl snail belongs to the subclass Pulmonata. This means it is a monoecious (one house) species. In other words, all of these snails have both female and male sex organs. To ensure that self-fertilization does not occur, the sperm develops a lot earlier than eggs do. This way by the time the eggs are mature, the sperm of the individual is already gone, and the sperm of a separate individual can fertilize the eggs. Sperm cells are transferred from one individual to another through the spermatophore (Nordsieck, 1999). Both individuals are capable of transferring sperm to each other at the same time. The eastern whorl snail has direct development. It lays its fertilized eggs into a moist hole. After about 25 days the snails emerge from the eggs (Nordsieck, 1999).  While inside the egg, the snail goes through two different larval stages, and a metamorphous. The first larval stage is called trochophore stage.Trochophore stage During this stage, the trochophore is a free swimming, ciliated individual. The next stage is a form called veliger (Nordsieck, 1999). Veliger stageThis is when the snail starts to look more like a snail. It still has a cilia, but also the beginnings of a shell and most of it's adult organs. The snail then goes through metamorphous where it turns into a juvenile snail. All of these stages take place inside the eggs of terrestrial snails, since water is not accessible (Nordsieck, 1999).