An account of the structure of plants naturally begins with the cell which is the proximate unit of organic structure. The elementary unit of plant structure, as of animal structure, is the cell. Faunistically, although not geographically, the Nearctic and Palaearctic areas must form the two subdivisions of one great unit, for which the  Holarctic region  is now the generally accepted term.
Definition: a subclass considered a phylum of the kingdom Protista in some classifications; includes holozoic or saprozoic flagellates.
The ciliates are a group of protozoans characterized by the presence of hair-like organelles called cilia, which are identical in structure to eukaryotic flagella, but in general shorter and present in much larger numbers, with a different undulating pattern than flagella.n most systems of taxonomy,  Ciliophora  is ranked as a phylum, under either the kingdom Protista or Protozoa. In some systems of classification, ciliated protozoa are placed within the class  Ciliata, (a term which can also refer to an unrelated genus of fish).