(Meunier) Kofoid & Swezy (1921: 314, fig. EE6)
Spirodinium lachryma Meunier (1910: 63, pl. 14, figs 21, 22)
Balech (1976: 21, fig. 12), Dodge (1982: 102, fig. 12C), Andreoli et al. (1995: 473), Steidinger & Tangen (1997: 453, pl. 20)
Cells large, 60–135 µm long, 28–50 µm wide. Epitheca and hypotheca ±equal in size; epitheca conical to tear-drop-shaped; hypotheca rounded. Girdle broad, incised and offset by c. one-quarter of the cell length. Cell wall thick.
Coastal areas of Prydz Bay, East Antarctica, including saline lakes; Terra Nova Bay (Andreoli et al., 1995); Weddell Sea (Estrada & Delgado, 1990, as G. cf. lachryma); Antarctic pack-ice (Garrison, 1991b); Arctic, Antarctic and eastern U.S.A. (Dodge, 1982).
Unarmoured cells, sometimes compressed. Cingulum displaced by at least 20-35% of the cell length (cf. Gymnodinium) in a descending left spiral. Individual species are differentiated by size, shape and contours, the presence and shape of the apical groove, the presence of striae, ribs or furrows, total displacement of the cingulum, torsion of the sulcus, the presence of chloroplasts, lateral compression of the body and colour (Steidinger & Tangen, 1997). See Larsen (1994, 1996) for a discussion of the separation of Gymnodinium and Gyrodinium.
Balech (1976) reported the presence of small, irregular chloroplasts.