A snail glides across the pavement during a rainy evening on Friday, Feb. 6, 2009,  in Santa Monica. According to Wikipedia, the word snail is a common name for almost all members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word snail is used in a general sense, it includes sea snails, land snails and freshwater snails. Snails lacking a shell or having only a very small one are usually called slugs. Snails can be found in a wide range of environments from ditches, deserts, and the abyssal depths of the sea. Although most people are familiar with terrestrial snails, land snails are in the minority. Marine snails have much greater diversity and a greater biomass. The great majority of snail species are marine.