540 EXPLANATION OF THE PLATES. 



PLATE II. 



Figures of BACiLLARiiE : Section Naviculacea. 



Fig. 1. 1. a. Pyxidicula operculata, p. 135. 



" 2. 2. a. b. Pyxidicula ? p. 135. 



" 3. Gaillonella moniliformis, p. 135. 



" 4. 4. a. b. Gaillonella aurichalcea ; c. a globular joint, 



" 5. Gaillonella distans, p. 137. [p. 136. 



" 6. a. b. Gaillonella, varians, p. 137. 



" 7. Gaillonella sulcata, a jointed cylinder, composed of 

 several individuals ; b. base of a joint, p. 138. 



" 8. Gaillonella? p. 139. 



" 9, 10. Actinocyclus , p. 110. 



" 11. a. b. Actinocyclus, a. base ; b. side view, showing the 

 alternate elevations and depressions which cause 

 the light and dark portions seen on a. p. 140. 



" 12. a. b. Coscinodiscus lineatus, p. 142. 



" 13. a. b. Coscinodiscus patina, p. 143. 



" 14. Coscinodiscus radiatus, p. 142. 



" 15. Scale of yVo millimetre, magnified equally with the 

 sketches. 



" 16. a. b. Navicula viridis, c. c. c. c. the orifices, p. 144. 



" 17. a. b. Navicula viridis, copied from Ehrenberg, p. 144. 



" 18. Navicula , p. 145. 



" 19. Navicula , p. 145. 



" 20. Navicula , p. 145, 



" 21'. a. b. Navicula striatula, p. 145. 



" 22. Navicula , p. 146. 



" 23. a. b. Navicula , p. 146. 



" 24. a. b. Navicula sigma, p. 147. 



" 25. a. b. Emersonia p. 147. 



" 26. a. b. c. Eunotia arcus ; c. cross section, p. 147. 



" 27. a. b. c. Eunotia ; c. cross section, p. 148. 



" 28. Eunotia monodon, p. 148. 



" 29. Eunotia diodon, p. 148. 



" 30. Eunotia triodon. 



" 31. Eunotia tetraodon, p. 148. 



" 32. Eunotia pentodon, p. 148. 



" 33. Eunotia serra, p. 148. 



" 34. Cocconeis , p. 149. 



" 35. Bacillaria paradoxa, p. 149. 



" 36. a. b. Bacillaria ? tabellaris, p. 150. 



" 37. a. b. Bacillaria tabellaris, full grown? p. 150. 



" 38. Bacillaria marina? p. 150. 



" 39. Tessela catena? p. 151. 



" 40. Fragillaria pectinalis, p. 151. 



" 41. Fragillaria bipunctata? p. 151. 



" 42. a. b. Meridion vernale, p. 152. 



