1. Species Oocystis apiculata West, 1893
2. Species Oocystis apicurvata G.J.P.Ramos, C.E.M.Bicudo & C.W.N.Moura, 2015
3. Species Oocystis arctica Prescott, 1965
4. Species Oocystis austriaca Hindák, 1988
5. Species Oocystis biplacata (Skuja) Hindák, 1988
6. Species Oocystis bispora Komárek, 1983
7. Species Oocystis borgei J.W.Snow, 1903
8. Species Oocystis brevispina H.Silva, 1953
9. Species Oocystis chodatii Playfair, 1916
10. Species Oocystis cingulatus Hortobagyi & Németh, 1963
11. Species Oocystis compacta V.N. Baturina, 1966
12. Species Oocystis composita Proschkina-Lavrenko, 1968
13. Species Oocystis elegans Gonzalves & K.R.Mehra, 1959
14. Species Oocystis elliptica West, 1892
15. Species Oocystis geminata Nägeli ex A.Braun, 1868
16. Species Oocystis hunanensis C.-C.Jao, 1940
17. Species Oocystis irregularis (Petkoff) Printz, 1913
18. Species Oocystis kolhapurensis N.D.Kamat, 1963
19. Species Oocystis kumaoensis K.P.Singh, 1960
20. Species Oocystis lacustris Chodat, 1897
21. Species Oocystis macrospora (W.B.Turner) Brunnthaler, 1915
22. Species Oocystis maharastrensis N.D.Kamat, 1963
23. Species Oocystis mamillata W.B.Turner, 1893
24. Species Oocystis marina L.Moewus, 1951
25. Species Oocystis marssonii Lemmermann, 1898
26. Species Oocystis naegelii A.Braun, 1855
27. Species Oocystis natans (Lemmermann) Lemmermann, 1908
28. Species Oocystis nodulosa West & G.S.West, 1894
29. Species Oocystis novae-semliae Wille, 1879
30. Species Oocystis obtusa Hortobágyi & Németh, 1963
31. Species Oocystis pandoriformis
32. Species Oocystis panduriformis West & G.S.West, 1894
33. Species Oocystis parva West & G.S.West, 1898
34. Species Oocystis pelagica Lemmermann, 1901
35. Species Oocystis polymorpha Groover & Bold, 1968
36. Species Oocystis pusilla Hansgirg, 1890
37. Species Oocystis pyriformis Prescott, 1944
38. Species Oocystis rhomboidea Fott, 1933
39. Species Oocystis rifeum P.González, 1929
40. Species Oocystis rupestris Kirchner, 1880
41. Species Oocystis socialis Ostenfeldt, 1902
42. Species Oocystis sphaerica W.B.Turner, 1893
43. Species Oocystis sphaerica Meunier, 1910
44. Species Oocystis striata P.González, 1947
45. Species Oocystis subhexagona Playfair, 1916
46. Species Oocystis submarina Lagerheim, 1886
47. Species Oocystis tainoensis Komárek, 1983
48. Species Oocystis alpina Reisigl, 1964 accepted as Ecdysichlamys alpina (Reisigl) Komárek & Comas, 1984
49. Species Oocystis asterifera Skuja, 1964 accepted as Skujaster asteriferus (Fott) D.G.Vodenicarov, 1989 (synonym)
50. Species Oocystis ciliata Lagerheim, 1882 accepted as Lagerheimia ciliata (Lagerheim) Chodat, 1895 (synonym)
51. Species Oocystis cohaerens Skuja, 1964 accepted as Catenocystis cohaerens (Skuja) Hindák, 1988
52. Species Oocystis coronata Lemmermann, 1911 accepted as Granulocystopsis decorata (Svirenko) Tsarenko, 2000 (synonym)
53. Species Oocystis crassa Wittrock, 1880 accepted as Neglectella solitaria (Wittrock) Stenclová & Kastovsky, 2017 (synonym)
54. Species Oocystis ecballocystiformis M.O.P.Iyengar, 1932 accepted as Elongatocystis ecballocystiformis (Iyengar) L.Krienitz & C.Bock, 2011
55. Species Oocystis echidna Bohlin, 1898 accepted as Franceia echidna (Bohlin) Bourrelly, 1948 (synonym)
56. Species Oocystis echinulata Proshkina-Lavrenko, 1967 accepted as Granulocystis echinulata (Proshkina-Lavrenko) Hindák, 1977 (synonym)
57. Species Oocystis eremosphaeria G.M.Smith, 1918 accepted as Eremosphaera eremosphaeria (G.M.Smith) R.L.Smith & Bold, 1966 (synonym)
58. Species Oocystis gigas W.Archer, 1877 accepted as Eremosphaera gigas (W.Archer) Fott & Kalina, 1962 (synonym)
59. Species Oocystis granulata Hortobágyi, 1962 accepted as Oocystopsis granulata (Hortobágyi) Heynig, 1991
60. Species Oocystis heteromucosa Hegewald, 1980 accepted as Oocystella heteromucosa (Hegewald) Hindák, 1988 (synonym)
61. Species Oocystis minuta Guillard, Bold & MacEntee, 1975 accepted as Ecdysichlamys minuta (Guillard, Bold & MacEntee) Komárek & Comas, 1984
62. Species Oocystis mongolica Antipova, 1964 accepted as Oocystella mongolica (Antipova) Hindák & Zagorenko, 1992 (synonym)
63. Species Oocystis nephrocytioides Fott & Cado, 1966 accepted as Oocystella nephrocytioides (Fott & Cado) Hindák, 1988 (synonym)
64. Species Oocystis ornata Fott, 1933 accepted as Siderocelis ornata (Fott) Fott, 1934 (synonym)
65. Species Oocystis ovalis (W.B.Turner) West & G.S.West ex Playfair, 1916 accepted as Neglectella ovalis (W.B.Turner) D.G.Vodenicarov, 1989
66. Species Oocystis planctonica Chodat, 1931 accepted as Oocystis parva West & G.S.West, 1898
67. Species Oocystis polychaeta P.P.Schirschoff, 1937 accepted as Franceia polychaeta (P.P.Schirschoff) Korshikov, 1953
68. Species Oocystis pseudocoronata Korshikov, 1939 accepted as Granulocystopsis decorata (Svirenko) Tsarenko, 2000 (synonym)
69. Species Oocystis rotula Playfair, 1916 accepted as Neglectella rotula (Playfair) D.G.Vodenicarov, 1989
70. Species Oocystis ruzickae Reháková, 1969 accepted as Granulocystis ruzickae (Reháková) Hindák, 1977 (synonym)
71. Species Oocystis solitaria Wittrock, 1879 accepted as Neglectella solitaria (Wittrock) Stenclová & Kastovsky, 2017
72. Species Oocystis subsphaerica Playfair, 1916 accepted as Neglectella rotula (Playfair) D.G.Vodenicarov, 1989
73. Species Oocystis verrucosa J.V.Roll, 1927 accepted as Granulocystis verrucosa (J.V.Roll) Hindák, 1977 (synonym)
74. Species Oocystis asymmetrica West & G.S.West, 1894 (uncertain)
75. Species Oocystis atmophytica Krieger, 1944 (uncertain, uncertain taxonomic status subjected to verification)
76. Species Oocystis australiensis Playfair, 1916 (uncertain)
77. Species Oocystis conglomerata Atari, 1902 (uncertain, synonym)
78. Species Oocystis gloeocystiformis O.Borge, 1906 (uncertain)
79. Species Oocystis incrassata (West & G.S.West) Cedergren, 1932 (uncertain, uncertain taxonomic status subjected to verification)
80. Species Oocystis minima Lagerheim, 1884 (uncertain, uncertain taxonomic status subjected to verification)
81. Species Oocystis mucosa Lemmermann, 1908 (uncertain, uncertain taxonomic status subjected to verification)
82. Species Oocystis natans G.M.Smith, 1918 (uncertain)
83. Species Oocystis nordstedtiana (De Toni) Playfair, 1916 (uncertain)
84. Species Oocystis setigera W.Archer (uncertain, uncertain taxonomic status subjected to verification)
85. Species Oocystis subsphaerica Messikommer, 1951 (uncertain, uncertain taxonomic status subjected to verification)

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