Stephanoeca diplocostata Ellis, 1930

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 : 489

Stephanoeca diplocostata Ellis, 1930

(fi gures 1c, 2c)

Description. Collar fl agellate with lorica divided into two chambers by a waist at about two- fi fths of the distance from the base of lorica. Loricae with transverse and horizontal costae. Cell has a single apical fl agellum. The fl agellum is as long as the cell body. The cell body is about 10 Mm long with a pedicel and fi lls the posterior chamber of the lorica. The cells attach to the substratum with the pedicel or with the posterior end of the lorica. Two cells observed.

Remarks. This species resembles Stephanoeca diplocostata Ellis, 1930 in general appearance, size and shape. We identi fi ed this species as S. diplocostata with uncertainty because the identity of most acanthoecid choanoflagellates can only be con- fi rmed through electron microscopical observation. This species has been found in Antarctica, subtropical Australia, Denmark, England, USA ( Ellis, 1930; Thomsen, 1973; Thomsen et al., 1991, 1997; Leadbeater, 1994; Tong, 1997 a, 1997b). One of two cells observed here had a pedicel, but another one did not. The pedicel in Stephanoeca diplocostata may be present or absent according to the stage of the life cycle ( Leadbeater, 1979).