EXPLANATION OF THE PLATES. 



PLATE I. . ■ 



Figures of Bacillari.e : Section Desmidiacea. 



Fig. 1. Desmidium Schwartzii, p. 117. 

 " 2, 3, 4, 5, G, 7. Euastrum, difierent positions. 

 " 8. Euastrum margaritiferura, Ehr. a. b. different posi- 

 tions, p. 125. 



9. Euastrum , a. b. two positions, p. 125. 



" 10. Euastrum , p. 125. 



" 11,12. Euastrum , p. 126. 



" 13. Euastrum , p. 125. 



" 14. Euastrum , p. 126. 



" 15. Xanthidium , p. 120. 



" 16. a. b. Xanthidium , p. 120. 



" 17. Arthrodesmus quadricaudatus, p. 121. 

 " 18. Artlii-odesmus cutus, p. 121. 

 " 19. Micrasterias Tetras, p. 122. 

 " 20. Micrasterias Boryana, p. 122. 



" 21. Mcrasterias , p. 122. 



" 22. Euastrum rota, Ehr. p. 123. 



" 23. Euastram crux-meKtensis ? Ehr. p. 123. 



" 24. Euastrum, possibly a young E. rota, p. 124. 



" 25. Euastrum , p. 124. 



" 26, 27. a. b. Euastrum , c. d. smaller individuals, 



(Echinella oblonga of Greville ?) p. 124. 



" 28. Euastrum , p. 124. 



" 29. Euastrum , p. 124. 



" 30. Closterium lunula, p. 132. 

 " 31. Closterium monihferum, p. 132. 

 " 32. Closterium trabecula ? p. 132. 

 " 33. Closterium digitus? p. 133. 

 " 34. Closterium lineatum ? p. 133. 

 " 35. Closterium striolatum, p. 133. 

 " 36. Closterium rostratum, p. 133. 

 " 37. Closterium tenue ? p. 134. 



" 38. Closterium , p. 134. 



39. Scale, each division of which represents yV°(j of a mil- 



hmetre magnified equally with the sketches. 



