Species (22.489)
- Strombidium obtusum
- Strombidium marinum
- Strombidium pelagica ssp. pelagica
- Strombidium planctonicum ssp. planctonicum
- Strombidium platum
- Strombidium polymorphum
- Strombidium pollostomum
- Strombidium rhynchum
- Strombidium sauerbrayae ssp. sauerbrayae
- Strombidium sauerbreyae Kahl
- Strombidium shicatum
- Trithigmostoma hyalina Kidder & Summers 1935
- Strombidium sphaericum
- Strombidium stylifer
- Strombidium tressum
- Strombidium tipicum
- Euplotes harpa ssp. baikalensis
- Strombilidium gyrans
- Strombiformis subulata
- Strombidium triquetrum
- Stylohedra lenticula
- Stylonchia curvata
- Stylonethes sterkii Garnjobst 1934
- Stylonichia histrio
- Stylonichia notophora
- Stylonichia mytilus
- Stylonichia putrina
- Opistotricha terricola Gellert 1957
- Stylonichia vorax
- Stylonychia balatonica
- Stylonichya mytilus Ehrenberg
- Stylonychia complanatus
- Stylonychia appendiculatus Ehrenberg 1838
- Stylonychia fissieta Conn 1905
- Stylonychia kahli Dragesco 1966
- Stylonychia makrostyla Sterki 1878
- Stylonychia microstoma
- Stylonychia minimus
- Stylonychia ovalis Dragesco 1966
- Pleurotricha grandis
- Stylonychia mytilus Müller 1773 ssp. mytilus
- Oxytricha grandis Maupas
- Styloplotes quennerstedti
- Styloplotes norvegicus
- Stichotricha ophistotonoides
- Stichotricha multinucleata
- Stichotricha remex
- Laurentiella acuminata
- Stilonichia pulchra
- Stilostomella elegans
- Stomiosphaera conoidea
- Stomiosphaera moluccana Wanner 1940
- Stomiosphaera colomi
- Stomiosphaera moreti
- Stomiosphaera sphaerica
- Stravolaema melitea
- Storthosphaera albida
- Podophrya sandi
- Strobilidium adhaerens
- Parapodophrya sparganium Kahl 1931
- Strobilidium cometa
- Strobilidium gorgonum
- Strobilidium rapulum
- Strobilidium spirales
- Strombidinopsis batos
- Strombidinopsis acuminatum
- Strombidinopsis chilorhax
- Strombidinopsis cercionis
- Strombidinopsis lohmanni
- Nassula nahchivanica
- Strombidinopsis proboscidifer
- Strombidinopsis spiniferum
- Strombidinopsis sphaira Lynn, Montagnes & Dale 1991
- Strombidium alveolare
- Stenophaga doliolum
- Stenosemella oliva
- Stenosemella brevicolli
- Stenosemella bernhardi
- Stenosemella compressa
- Stenosemellopsis ruggierii
- Stentor amthystinus Leidy 1880
- Stentor caerulescens
- Stentor auriculatus Gruber 1884 ssp. auricula
- Stentor cucullus
- Stentor coerulens Ehrenberg 1830
- Stentor igneus Forbes 1891 ssp. fuliginosus
- Stentor mülleri
- Stentor multiphormis
- Stentor pruniformis
- Stentor roeselli
- Stentor röselii
- Stentor socialis
- Stephanelytron redcliffense
- Stephanelytron scarburghense
- Stephanidina volvox Eichwald 1852
- Sterkiella similis Buitkamp 1977 ssp. tricirrata
- Stichotricha concorta
- Stichospira univacuolata
- Stichotricha muelleri
- Stichotricha mülleri