Nudibranchs belong to phylum Mollusca, class Gastropoda, order Nudibranchia. Found in oceans all over the world, they range in size from .25 inch to longer than a foot. There are more than 3,000 ...

Snails are the common name for land snails, or terrestrial pulmonate gastropod mollusks. In simple terms, land animals that breathe with lungs, in the class Gastropoda, that have a shell.