Kingdom [Animalia] Linnaeus, 1758 - animals Subkingdom Protozoa Goldfuss, 1818 see Kingdom Protozoa Goldfuss, 1818 Class Ciliata see [unranked] ciliates Order Spirotricha Suborder Heterotricha Stein, 1859 Genus [Nyctotherus] Leidy, 1849 Nyctotherus cordiformis Ehrenberg, 1838 see Nyctotheroides cordiformis (Ehrenberg, 1838) Grassé, 1928