Species (15.149)
- Daturella recta Kofoid & Campbell 1929
- Daturella striata Kofoid & Campbell 1929
- Deltopylum rhabdoides Faure-Fremiet & Mugard 1946
- Dendrocometes gigas Swarczewsky 1928
- Dendrocometes robustus Swarczewsky 1928
- Dendrocometes gracilis Swarczewsky 1928
- Dendrocometides priscus Swarczewsky 1928
- Dendrophrya gemmipara Sand 1895
- Dendrosoma radians Ehrenberg 1837
- Dendrosomides lucticutiae Bowman 1977
- Dendrosomides truncata Dons 1918
- Dendrosomides paguri Collin 1905
- Dentacineta campanuliformis Collin 1909
- Dentichona marginata Jankowski 1973
- Cycloposthium dentiferum Gassendi ß
- Desmophrya contorta Raabe 1933
- Deviata bacilliformis Gelei 1954
- Desicaryon sp. Jankowski 1979
- Dexiotricha centralis Stokes 1885
- Dexiostoma campylum Stokes 1886
- Dexiotricha granulosa Kent 1881
- Dexiotricha colpidiopsis Kahl 1926
- Dexiotricha plagia Stokes 1885
- Dexiotricha tranquillus Kahl 1926
- Dexiotrichides centralis Stokes 1885
- Diafolliculina rotunda Hadzi 1951
- Diafolliculina similis Hadzi 1951
- Diafolliculina thomseni Hadzi 1951
- Diaxonella rubra Jankowski 1979
- Diaphanosoma arcuata Grandori & Grandori 1934
- Diceras bicornis Kahl 1930
- Dichilum cuneiforme Schewiakoff 1892
- Diceratula viridans Corliss 1960
- Dichilum intermedium Gajevskaja 1927
- Dichilum platessoides Faure-Fremiet 1924
- Dichilum wrzesniowskii Mereschkowski 1877
- Dicoelophrya almae Puytorac & Dragesco 1969
- Dicloeopella borealis Eicher 1965
- Dicoelophrya calliste Puytorac & Dragesco 1969
- Dicoelophrya callistes Puytorac & Dragesco 1968
- Dictyocysta apiculata Wailes 1925
- Dictyocysta ampla Kofoid & Campbell 1929
- Dellochus mucicola Corliss 1960
- Delphyella filum Claparède 1860
- Deltacineta seticola Jankowski 1981
- Dendrocometes discoideus Swarczewsky 1928
- Dictyocysta californiensis Kofoid & Campbell 1929
- Dictyocysta duplex Brandt 1906
- Dictyocysta elegans Ehrenberg 1854
- Dictyocysta entzi Jörgensen 1924
- Dictyocysta extensa Kofoid & Campbell 1929
- Dictyocysta fenestrata Kofoid & Campbell 1929
- Dictyocysta grandis Brandt 1906
- Dictyocysta funlandica Ehrenberg 1854
- Dictyocysta lata Kofoid & Campbell 1929
- Dictyocysta inaequalis Brandt 1906
- Dictyocysta lepida Ehrenberg 1854
- Dictyocysta magna Kofoid & Campbell 1929
- Dictyocysta mitra Haeckel 1873
- Dictyocysta minor Jörgensen 1924
- Dictyocysta mexicana Kofoid & Campbell 1929
- Dictyocysta nidulus Kofoid & Campbell 1929
- Dictyocysta mülleri Imhof 1886
- Dictyocysta occidentalis Kofoid & Campbell 1929
- Dictyocysta ovalis Daday 1886
- Dictyocysta reticulata Kofoid & Campbell 1929
- Didieria ohioensis Small & Lynn 1985
- Didinium alveolatum Kahl 1930
- Didinium balbiani Fabre-Domergue 1888
- Dileptus acutus Dumas 1929
- Dileptus alpinus Kahl 1931
- Dileptus anduncus Dumas 1929
- Dileptus anguillula Kahl 1931
- Dileptus anas Müller 1773
- Dileptus amphileptoides Kahl 1931
- Dileptus americanus Kahl 1931
- Dileptus arcuatus Dumas 1929
- Dileptus biacuta Dumas 1937
- Dileptus bicaudatus Dumas 1929
- Dileptus bicornis Dumas 1929
- Dileptus bicristatus Dumas 1929
- Dileptus binucleatus Kahl 1931
- Dileptus cilunculus Dumas 1930
- Dileptus conspicuus Kahl 1931 ssp. conspicuus
- Dileptus clavipes Dumas 1929
- Dileptus corniculatus Dumas 1929
- Dileptus conspicuus Gellert 1955 ssp. telobivacuolatus
- Dileptus corniger Fromentel 1876
- Dileptus costaricanus Foissner 1995
- Dileptus crinitus Müller
- Dileptus costatus Dumas 1929
- Dileptus cristatus Dumas 1937
- Dileptus crispatus Dumas 1930
- Dileptus cuspidatus Dumas 1929
- Dileptus cylindricus Fromentel 1876
- Dileptus cygnus Claparède & Lachmann 1859
- Dileptus cylindroides Dumas 1929 ssp. non
- Dileptus diaphanus Dumas 1929
- Dileptus decorus Dumas 1929
- Dileptus ectromeloides Dumas 1937