PLATE XIII 



Fig. i. Planktoniella sol (Wallich) Schiitt; oblique view of cell. 



Fig. 2. Coscinodiscus Grant Gough; cell in girdle view showing eccen- 

 tricity of the convexity of the valves (diagrammatic). 



Fig. 3. Coscinodiscus bouvet Karsten; cell in girdle view (diagrammatic). 



Fig. 4. Coscinodiscus bouvet Karsten; cell in girdle view, showing one 

 valve more conical than the other (diagrammatic). 



Fig. 5. Biddulphia anthropomorpha Van Heurck; cells in chain forma- 

 tion, girdle view: hyaline cell at top end of the chain, spinous cell at 

 the lower end. 



Fig. 6. Chaetoceros peruvianum Brightwell ; girdle view showing proto- 

 plasmic contents ; and striate bristles. 



Fig. 7. Chaetoceros criophilum Castracane ; girdle view showing proto- 

 plasmic contents. 



Fig. 8. Eucampia balaustium Castracane; cell in valve view. 



Figs. 9, 10. Eucampia balaustium Castracane ; cells forming chains, girdle 

 view. 



Fig. 11. Fragilariopsis antarctica (Castracane) Hustedt; cell in valve 

 view. 



Fig. 12. Fragilariopsis antarctica (Castracane) Hustedt; cell in girdle 

 view. 



Fig. 13. Chaetoceros Schimperianum Karsten; cell in girdle view. 



Fig. 14. Chaetoceros Schimperianum Karsten; cell in valve view. 



