Notice of Ehrenberg's Memoir on Microscopic Life. 301 



1. 



2. 



3. 



4. 



5. 



6. 



7. 



8. 



9. 

 10. 

 11. 

 12. 

 13. 

 14. 

 15. 

 16. 

 17. 

 18. 

 19. 

 20. 

 21. 

 22. 

 23. 



A. Siliceous 



Actinocyclus quinarius. 



" denarius. 



" undenarius. 



" duo-denarius. 



" bioctonarius. 



Actinoptychus senarius. 



" octonarius. 



" duodenarius. 



" sedenarius. 



" denai'ius. 



" vicenarius. 



" Jupiter. 



Amphora libyca. 

 Biddulphia tridentata. 

 Cocconeis amphiceros. 



" leptoceros. 



Coscinodiscus argus. 



" concavus. 



" limbatus. 



" lineatus. 



" marginatus. 



" gigas. 



" minor. 



Infusoria. 



24. Coscinodiscus oculus iridis. 



25. " radiatus. 



26. " radiolatus. 



27. Dictyocha crux. 



28. " fibula. 



29. " pentasterias. 



30. Eunotia diodon. 



31. " monodon ? 



32. Fragillaria amphiceros. 



33. " lsevis. 



34. " pinnata. 



35. Gallionella sulcata. 



36. Goniothecium Rogersii. 



37. Grammatophora oceanica. 



38. " undulata ? 



39. Haliomma ? 



40. Himantidium Arcus ? 



41. Navicula sigma. 



42. Pinnularia peregrina. 



43. Pyxidicula cruciata. 



•44. Rhizosolenia Americana. 



45. Stauroptera ? 



46. Triceratium obtusum. 



B. Siliceous parts of Plants. 



47. Spongiolithis acicularis. 



48. " caput serpentis. 



49. " cenocephala. 



50. Spongiolithis clavus. 



51. " fistulosa. 



52. " fustis. 



" Among these fifty two forms are forty six infusoria, belonging to 

 twenty genera, which genera are all European with the exception of 

 two, Goniothecium and Rhizosolenia,* which have not been observed 



* " Goniothecium. Genus e familia Bacillariorum, sectione Naviculaceorum. 

 Lorica simplex silicea teres nunquam catenata, slrictura media fine utroque subito 

 attenuato, el truncato hinc tanquam anguloso. = Pyxidicula media constricta utrin- 

 que truncata." 



" G. Rogersii, articulis Iambus hyalinis." 



" Rhizosolenia. Genus e familia Bacillariorum, sectione Naviculaceorum. 

 Characteres Pyxidicula aut Gallionellse, loricae tubulosae altero fine rotundato 

 clauso, altero attenuato multifido tanquam radiculoso." 



" R. Americana, testulae tubulis hyalinis lsevibus." 



"A curious and very distinct form, whose systematic position is uncertain; only 

 three specimens were seen, all of which were imperfect." 



