LIST OF STATIONS i 99 



St. MS 97. 22.1.31. Position as St. MS 95. 50-0 m. 



Temp. 2-90° C. Salinity 32-56 % . pU 8-07. P 2 O s 51. 



Coscinodiscus centralis Ehrenberg Corethron criophilum Castracane 



Coscinodiscus oculus-Iridis Ehrenberg Entopyla kerguelensis Karsten 



Fragilariopsis sublinearis (H. van Heurck) Heiden Cocconeis pinnata Gregory ex Greville 



et Kolbe Cocconeis imperatrix Schmidt 

 Licmophora Lyngbyei (Kiitzing) Grunow 



St. MS 98. 29. i. 31. Position as St. MS 95. 50-0 m. 



Temp. 2-50° C. Salinity 32-25 % . pH 8-07. P 2 5 83. 



Fragilariopsis sublinearis (H. van Heurck) Heiden Licmophora Lyngbyei (Kiitzing) Grunow 



et Kolbe Coscinodiscus oculus-Iridis Ehrenberg 



Coscinodiscus centralis Ehrenberg 



St MS 99. 5. ii. 31. Position as St. MS 95. 50-0 m. 



Temp. 2-85° C. Salinity 32-66 °/ O0 . pH 8-12. P 2 5 84. 



Fragilariopsis sublinearis (H. van Heurck) Heiden Licmophora Lyngbyei (Kiitzing) Grunow 



et Kolbe Biddulphia striata Karsten 



Coscinodiscus centralis Ehrenberg Corethron criophilum Castracane 



St. MS 100, 101, 102, 103. 12. ii. 31-5. iii. 31. Positions as St. MS 95. 50-0 m. 



Fragilariopsis sublinearis (H. van Heurck) Heiden Corethron criophilum Castracane 



et Kolbe Cocconeis antiqua Tempere et Brun 



Coscinodiscus centralis Ehrenberg Coscinodiscus oculus-Iridis Ehrenberg 

 Licmophora Lyngbyei (Kiitzing) Grunow 



CLASSIFICATION 



The classification of diatoms has undergone considerable change from time to time, 

 and the earlier schemes such as those proposed by Wm Smith (1853) and others, based 

 upon the modes of living adopted by the various species, have been entirely abandoned ; 

 during recent years the classification proposed by Schutt in 1896 has completely domi- 

 nated the literature. 



The fundamental principle of SchiAtt's scheme is the division of the entire group into 

 two suborders, namely Centricae and Pennatae. 



In the Centricae the main structure of the valve was said to be arranged with re- 

 ference to a central point, either radiating from it or concentric about it. In the Pennatae 

 the structure was said to be arranged with reference to a median line ; this line frequently 

 corresponded to the raphe which connects the polar nodules of the valve, and was at 

 right angles to the principal axis of the frustule. 



This method has been adopted in the main by Karsten (1905, 1928). Heiden and 

 Kolbe (1928) changed the names of the two suborders to Radiales and Bilaterales and 

 Hustedt (1930) changed them to Centrales and Pennales; in fact all authors of the last 

 forty years have been influenced by Schutt. 



Owing to the difficulty of tracing the phylogeny of the diatoms or their affinities with 

 other groups, Karsten (1928) suggested that their status should be raised to that of a 



