Species (15.149)
- Membranophoridium aspinatum
- Meniscostomum stomioptycha
- Mesanophrys chesapeakensis
- Euplotes bisulcatus
- Mesanophrys pugettensis
- Mesnilella aculeata
- Mesnilella hynnis
- Mesnilella multispiculata
- Mesnilella paranaidos
- Mesnilella rostrata
- Mesnilella radiata
- Mesnilella stammeri
- Mesnilella spiculata
- Mesnilella taupodrili
- Mesnilella vermicularis
- Mesnilella trispiculata
- Mesodinium pulex Kahl 1933 ssp. pupula
- Mesodinium rubrum Lohmann 1908
- Mesodinium pupula Kahl 1933
- Mesodinium recurvum Kellicott 1885
- Mesodiscophrya hydroi
- Mesogymnus nudum
- Metacollinia luciensis Poisson 1921
- Metacyclina glandiformis
- Metacylis oviformis
- Metacylis sanyahensis
- Metanophrys durchoni
- Metaradiophrya euoplos
- Metasicuophora xavierae
- Metasicuophora petteri Albaret 1973
- Metastoma uncinata
- Metopus tortus ssp. tortus
- Mathurosphaera rajivi
- Maupasella eupolytoreuti
- Metafolliculina ballerina
- Metastrombidium sonnifer Jankowski 1980
- Metaurostyla magna Alekperov 1984
- Metaxystomium sp.
- Metaurostyla raikovi Alekperov 1984
- Metoikos nudum
- Metopus aurantiacus
- Metopus caucasicus
- Metopus fuscoides
- Metopus lemani Dragesco 1960
- Metopus pulcher Kahl 1927 ssp. pulcher
- Metopus rectus ssp. rectus
- Metopus sigmoidea
- Metopus setosus Kahl 1927
- Metopus tesselatus
- Mesnilella beani
- Mesnilella bispiculata
- Meseres cordiformis
- Mesnilella bohemica
- Mesnilella depressa
- Mesnilella elongata
- Mesnilella fastigata
- Mesnilella maritui
- Micronyctus madagascari Tuzet & Manier 1954
- Microthorax hungaricus
- Micrundella kuroschii
- Micrundella ernesti
- Micrundella membranata
- Euplotopsis labiata Ruinen 1938
- Mimophrya acuta
- Mimophrya ozakii
- Spathidium microstomum
- Monurceolaria scoloplontis
- Mrazekiella intermedia
- Mondinium balbiani Fabre-Domergue 1888
- Monochilum elongatum
- Monochilum frontatum Schewiakoff 1893
- Didinium balbianii ssp. perrieri
- Monodontophrya kijenskiji
- Monodontophrya longissima
- Multiplicisphaeridium ramispinosum
- Multiplicisphaeridium spicatum
- Multiplicisphaeridium truncatum
- Multiplicisphaeridium sprucegrovensis ßß
- Strombidium cyclindromorphun
- Loxophylum armatum sensu Penard 1922
- Trichodina domerguei ssp. megamicronucleata
- Vorticella extensa ssp. extensa
- Pixidium hebes
- Placus longinucleatus
- Plagiotoma blattarum
- Plagiotoma coli
- Plagiotoma cordiformis
- Plagiotoma difforme
- Plagiotoma györyana
- Plagiotricha affinis Stein 1882
- Plagiotricha rouxi
- Plagiotoma pellogaster
- Plagiotricha strenua Engelmann
- Tintinnopsis formosa
- Planicola cristallina
- Planicola folliculata
- Planicola ingenita
- Planitrichidium natans
- Platycola amphoroides
- Platycola baikalica