Fig. 12. Diatomeen ties Schwarzen Sees. 

 13. Navicula tabellaria Kg. 2. Navicula stauroptera Gm. 4. Navicula gibba Kg. 5. Navicula 

 gigas E, (>. Navicula rhomboides E. 7. Navicula Hilseana Jan. 8. Navicula serians Kg. 9. Nitzschia 

 sigma 8m. 10. Stauroneis anceps var. gracilis. 11. 14. Surirella linearis Sm. 12. Navicula Bre- 

 bissonii Kg. 13. Navicula borealis Kg. 14. v. 11. 15. 20. Suriiella biseriata var. bif'rons Kg. 

 16. Himantidium arcus. 17. Gaillonella distans E. 18. Himantidium pectinale Kg. 19. Tabellaria 

 ttooulosa Ag. 20. v. 15. 21. Eunotia robusta Pritsch. 22. Cocconema parvura Sm. 23. Cymbella 

 stomatophora Gr. 21, llantzschia amphioxya Grun. 25. Gaillonella lirata Kg- 20. 28. Gaillonella 

 sp. 27. Himantidium majus var. bidens. Sm. 28. v. 2(>. 



