Microscopic is a term used to describe those objects smaller than can not be easily seen by the naked eye and which require a lens or microscope to see them clearly. By convention it's also used to describe classes of objects which are most commonly too small to see but of which some members are large enough to be observed with the eye. Such groups include the Cladocera, planktonic green algae of which Volvox is readily observable, and the protozoa of which Stentor can be easily seen without aid… (More on Microscopic)