SYSTEMATIC ACCOUNT 287 



Genus Climacodium Grunow 

 Grunow, 1870 

 Climacodium biconcavum (Ostenfeld) Cleve. (PL XII, fig. 13.) 



Cleve, 1897 a, p. 22, pi. 2, figs. 16, 17. 



Gran, 1905, p. 100, fig. 130. 



Karsten, 1906, p. 172, pi. 38, fig. 10. 



Hustedt, 1930, p. 777, fig. 454. 



Lebour, 1930, p. 189, fig. 149 b. 



Eucampia biconcava Ostenfeld, 1902, p. 241. 



Cells somewhat rectangular, united to form flat but often twisted chains. Valves face 

 to face. Valve surface concave, often deeply so, angles often slightly produced. When 

 seen in girdle view, the apertures between adjacent frustules are irregularly elliptic- 

 lanceolate. Cells very weakly siliceous, no structure visible. Chromatophores : numerous 

 cocciform bodies, usually grouped towards the centre of the cell. Polar axis of cell 44- 

 60/x ; pervalvar axis 54/x. 



An oceanic form widely distributed in tropical waters. Observed at one station only, 

 off the coast of Natal. 



Observed at St. 436. 



Climacodium Frauenfeldianum Grunow. (PI. XII, fig. 8.) 



Grunow, 1870, p. 102, pi. 1, fig. 24. 

 Gran, 1905, p. 100, fig. 129. 

 Karsten, 1906, p. 394, pi. 46, fig. 5. 

 Hustedt, 1930, p. 776, fig. 453. 

 Lebour, 1930, p. 189, fig. 149 a. 



Cells straight, united to form long flat chains, seldom twisted. Valves face to face, 

 linear-elliptical in outline. Valve surface sharply concave, raised at the poles to form 

 stout truncate processes. Central area flat. In girdle view, the apertures between ad- 

 jacent cells are large, oblong to oval. The apertures are usually greater than the cells. 

 Cells very weakly siliceous, no definite structure visible. Chromatophores : numerous 

 cocciform bodies, usually grouped towards the centre of the cell. Polar axis of cell 

 ioo-i8o/a; pervalvar axis 14-28/x. 



An oceanic species having a wide distribution in tropical and subtropical seas. 

 Frequently encountered around the coasts of Africa, particularly on the Indian Ocean 

 side. 



Observed at Sts. 425, 428, 440, 1373, 1570, 1572, 1584, 1586. 



Genus Streptotheca Shrubsole 

 Shrubsole, 1890 



Streptotheca thamesis Shrubsole. (PI. XII, fig. 11.) 



Shrubsole, 1890, p. 260, pi. 13, figs. 4--6. 

 Hustedt, 1930, p. 779, fig. 455. 

 Lebour, 1930, p. 190, fig. 150. 

 Gran, 1905, p. 101, fig. 131. 



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