Sketch of the Infusoria of the family Bacillaria. 305 



Fig. 8. a. b. Euastrum margaritiferum, page 295, a. b. different po- 

 sition of same individual. 



Fig. 9. a. b. Euastrum , page 296, a. b. two positions. 



Fig. 10. Euastrum , page 296. 



Fig. 11 and 12. Euastrum , page 296. 



Fig. 13. Euastrum , page 296. 



Fig. 14. Euastrum , page 297. 



Fig. 15. Xanthidium , page 291, a recent species from West 



Point. 



Fig. 16. a. b. Xanthidium , page 291, another species from West 



Point. 



Fig. 17. Arthrodesmus quadricaudatus, page 292. 



Fig. 18. a. b. Arthrodesmus cutus ? page 292. 



Fig. 19. Micrasterias Tetras, page 293. 



Fig. 20. Micrasterias Boryana, page 293. 



Fig. 21. Micrasterias , page 293. 



Fig. 22. Euastrum rota } page 294. 



Fig. 23. Euastrum Crux-Melitensis .? page 294. 



Fig. 24. Euastrum , page 294, possibly a young state of E. rota. 



Fig. 25. Euastrum , page 295. 



Fig. 26 and 27. 27 a. b. c. d. Euastrum , page 295, (Echinella 



oblonga of Greville .?) a. b. two positions of same individual, c. d. small- 

 er individuals. 



Fig. 28. a. b. Euastrum , page 295, two portions. 



Fig. 29. Euastrum , page 295. 



Fig. 30. Closterium lunula, page 302. 



Fig. 31. Closterium moniliferum, page 302. 



Fig. 32. Closterium trabecula > page 302. 



Fig. 33. Closterium digitus } page 303. 



Fig. 34. Closterium lineatum .? page 303. 



Fig. 35. Closterium striolatum, page 303. 



Fig. 36. Closterium rostratum, page 303. 



Fig. 37. Closterium tenue } page 303. 



Fig. 38. Closterium , page 303. 



Fig. 39. Scale, each division of which represents xixrth of a milli- 

 metre magnified equally with the sketches. 



NotcSmce the preceding sketch was sent to press, I have seen in Schlechtendal's 

 Linnsea for 1810, p. 201, a valuable memoir, by J. Meneghini, entitled Spiopsis Desmi- 

 diearum hucusque cognitarum. It gives a very good account of the genera and species, 

 •with copious lists of synonyms. 1 find my views as to the relations of several genera 

 confirmed on perusal of this Synopsis, which I recommend to the attention of students 

 of this curious class of bodies. J- " • B. 



Vol. xLi, No. 2.-July-Sept. 1841. 39 



