BULLETIN OF THE NATURAL HISTORY SOCIETY. 
239 
8. Nitschia scalaris E Sm. 
9. Nitschia closterium. 
10. Pleurosigma. 
1 1 . Pleurosigma Balticum. 
12. Pleurosigma fasciola E. 
13. Pleurosigma angulatum. 
14. Rhabdonema. 
15. Raphoneis (Doryphora) Boeclcii 
16. Rhipidophora. 
17. Rhizosolenia. 
18. Rhizosolenia setigera. 
27. Surirella Mollerianum.ii 
28. Surirella sp? 
29. Surirella sp? 
30. Synedra radians, side view. 
31. Synedra ulna, side view. 
32. Synedra radians, front view. 
33. Tabellaria. 
34. Triceratium altemans Bail. 
35. Tryb ionella scutellum? 
36. Zygoceros (Biddulphia) 
Mobilensis Bail. 
37. Odontidium. 
