PLATE XII 



Fig. i. Gossleriella tropica Schiitt; cell in valve view showing proto- 

 plasmic contents, and the double corona of stout spines at the 

 periphery. 



Fig. 2. Biddulphia regia (Schultze) Ostenfeld cell in valve view. 



Fig. 3. Ditto. Cell in girdle view, showing numerous cocciform 

 chromatophores. 



Fig. 4. Ditylum sol De Toni ; cell in girdle view. 



Fig. 5. Ditylum Brightwellii Grunow; cell in girdle view showing proto- 

 plasmic contents and intercalary scale-like marking upon the con- 

 nective zone. A temperate form. 



Fig. 6. Ditto. Cell in girdle view showing protoplasmic contents. 

 A warm-water form. 



Fig. 7. Eucampia zoodiacus Ehrenberg ; cells in ribbon formation, girdle 

 view. 



Fig. 8. Climacodium Frauenfeldianum Grunow; cells in ribbon forma- 

 tion, girdle view. 



Fig. 9. Biddulphia mobiliensis Grunow; cell in girdle view, showing 

 protoplasmic contents. 



Fig. 10. Eucampia cornuta Cleve; cell in girdle view showing the striate 

 bands of the connective zone. 



Fig. 11. Streptotheca thamesis Shrubsole; cells in spiral ribbon forma- 

 tion, showing chromatophores arranged upon protoplasmic threads 

 which radiate from the nucleus. 



Fig. 12. Ditto. A single cell in girdle view. 



Fig. 13. Climacodium biconcavum Cleve; cells in chain formation, girdle 

 view, showing protoplasmic contents. 



Fig. 14. Hemiaulus Hauckii Grunow; cells in ribbon formation, showing 

 protoplasmic contents. 



