(Cleve) Simonsen (1974: 47)
Navicula trompii Cleve (1901a: 932, fig. 11)
Heiden & Kolbe (1928: 625, pl. 3, fig. 77), Hasle & Syvertsen (1997: 278, pl. 62)
Cells solitary, weakly silicified. Valves lanceolate in valve view, tapering towards the ends; apical axis 70–160 µm; transapical axis 10–14 µm. Raphe central, straight; central raphe pores simple, very close together; terminal raphe endings hook-like. Transverse and longitudinal striae fine (but visible by LM), crossing at right angles; transverse striae 28–30 in 10 µm; longitudinal striae 17–20 in 10 µm. Chloroplasts 2, plate-like.
In pack-ice, c. 65°S 86°E, off Wilhelm II Land, “Gauss ” Expedition (Heiden, & Kolbe, 1928); Lützow-Holm Bay (Tanimura et al., 1990); southern cold-water region (Hasle & Syvertsen, 1997).
Navicula [Haslea] trompii var. major (Heiden & Kolbe, 1928) was also found in the present study, at Terra Nova Bay (Ross Sea). This variety has the following dimensions: apical axis 258–378 µm; transapical axis 20–27 µm; transapical striae 20 in 10 µm; and longitudinal striae 11–12 in 10 µm (Fig. 2.83c). Both varieties were reported from Antarctic pack-ice off Wilhelm II Land by Heiden & Kolbe (1928).