Ploeotia discoides Larsen and Patterson, 1990

Lee, Won Je & Patterson, David J., 2000, Heterotrophic flagellates (Protista) from marine sediments of Botany Bay, Australia, Journal of Natural History 34, pp. 483-562 : 527-529

Ploeotia discoides Larsen and Patterson, 1990

(fi gures 17b, 18e -g)

Description. Cell outline oval or elliptical, 11-13 Mm long, 7-8 Mm wide, dorsoventrally fl attened. Dorsally with two lateral grooves and one median groove, and ventrally with two lateral grooves which can be di ffi cult to see. The reservoir is located anteriorly in the left side of the cell and is roundish. The anterior fl agellum is about the length of the cell and the posterior fl agellum is about 1.5-2 times the length of the cell. The ingestion organelle reaches almost to the posterior end of the cell. Rarely observed. Observations based on six cells.

Remarks. This species was fi rst described by Larsen and Patterson (1990) from Brazil and cell length was previously reported to be 10-12 Mm. Ploeotia discoides resembles P. tenuis in having three longitudinal dorsal grooves, but it is distinguished by its lack of ventral grooves, fl atness, roundish reservoir, and by its smaller size ( Larsen and Patterson, 1990). The ventral grooves are very hard to see and may be absent in some cells. The differences between P. discoides and P. tenuis are not great and future work may demonstrate that there is no unambiguous discontinuity between the two taxa.