Redescriptions of two marine planktonic ciliates from China, Parastrombidium faurei (Kahl, 1932) Maeda, 1986 and Strombidium capitatum (Leegaard, 1915) Kahl, 1932 (Ciliophora, Oligotrichea).

The morphology and infraciliature of two marine planktonic ciliates, Parastrombidium faurei (Kahl, 1932) Maeda, 1986 and Strombidium capitatum (Leegaard, 1915) Kahl, 1932, from coastal waters near Qingdao (Tsingtao), northern China, were investigated based on live observation and protargol impregnation. This is the first time that these two species are reported from Yellow Sea/North Pacific. Emended diagnoses for the genus Parastrombidium and its single species P. faurei are provided as they were not studied with modern methods before. The ciliary pattern and the stomatogenesis of Parastrombidium indicate that it belongs to the order Choreotrichida Small and Lynn, 1985, family Strombidinopsidae Small and Lynn, 1985. An updated description for the "well-known"Strombidium capitatum is also included based on the Qingdao population.