peridiniidæ

Century Dictionary and Cyclopedia

1. The leading family of cilioflagellate infusorians, represented by Peridinium and several other genera, characterized by having a ciliate zone, or girdle of cilia, in addition to one or more flagella. These animalcules are free-swimming, of persistent form, inhabiting both fresh and salt water, often phosphorescent, loricate or sometimes illoricate, mostly with a single flagellum, frequently with an eye-like pigment-spot, and always with a distinct oral aperture. They reproduce by fission and by sporulation. The modern family corresponds to several older groups of similar names and less exact definition.