ABCDEFGHIJKLMNOPQRSTUVWXYZ

Authority

(Hust.) Hasle, in Hasle & Heimdal (1970: 569, figs 39–43)

Class

Diatomophyceae

Order

Centrales

Family

Thalassiosiraceae

Synonyms

N/A

top

Basionym

Coscinodiscus ritscheri Hust. (Hustedt, 1958: 117, figs 44–46)

Additional References

Johansen & Fryxell (1985: 176, figs 14, 56, 57), Fryxell & Johansen (1990: 99, pl. 11.8, fig. 10), Hasle & Syvertsen (1997: 86)

Description

Cells chain-forming by central threads, discoid in girdle view; pervalvar axis c. 20 µm. Valves slightly convex, circular, 42–72 µm diameter. Areolation fasciculate, linear or sublinear; areolae 12–16 in 10 µm, open to the outside by circular foramina with small finger-like projections (Fig. d). Marginal strutted processes in a single ring, 3–4 in 10 µm. Central strutted processes 1–many in a cluster (Fig. b–e), with small internal extensions. Labiate process solitary, near central strutted processes, internally slit-like (Fig. e).

Distribution

Southern Ocean, south of Australia; Antarctic sectors of the Atlantic and Pacific Oceans, Ross Sea, Weddell Sea (Johansen & Fryxell, 1985); Lützow-Holm Bay (Tanimura et al., 1990); Weddell-Scotia Confluence (Garrison et al., 1987).

Comments

N/A

top