A study of the soil flagellate Phalansterium solitarium Sandon 1924 with preliminary data on its ultra structure

The genus Phalansterium, which contains three named species, was created by Cienkowski (1870) for Monas consociatum Fresenius 1858. Ph. digitatum Stein 1878 from freshwater and Ph. solitarium Sandon 1924 from soil were later been added to the genus. Hibberd (1983) considered it possible that Phalansterium consociatum and Ph. digitatum are conspecific. As defined by light microscopy, members of the genus Phalansterium are colourless flagellates with a single flagellum. The proximal part of the flagellum is surrounded by a collar like structure. The cells excrete mucilage, which results in the formation of well structured colonies in Ph. digitatum and Ph. conso ciatum, and in loose unstructured lumps of cells in Ph. solitarium. Because of the single flagellum and the collar like structure, members of Phalansterium were previously associated with the choanoflagellates (e.g. Grandori and Grandori, 1934; Starmach, 1985). Ph. A study of the soil flagellate Phalansterium solitarium Sandon 1924 with preliminary data on its ultra structure