22 



PAL^ONTOLOGICAL BOTANY. 



16. 

 17. 



18. 

 19. 

 20. 

 21. 

 22. 

 23. 

 24. 

 25. 

 26. 

 27. 

 28. 

 29. 



30. 

 31. 

 32. 

 33. 

 34. 

 35. 

 36. 

 37. 

 38. 



Pnrbeck Beds. 



Portland Stone. 



Kimmeridge Clay. 



Coral Rag. J> Jurassic. 



Oxford Clay. 



Great or Batli Oolite. 



Inferior Oolite. 



Lias. 



Upper Trias. ^ 



Middle Trias. >- Triassic. 



Lower Trias. ) 



Permian. Permian. 



Coal Measures. ") 



Carboniferous lime- ^ Carboniferous. 



stone. ■/ 



Upper ") 

 Middle > Dev oniau. 



Secondary 

 or 



Mesozoic. 



>- Neozoic. 



Lower 

 Upper 

 Lower 

 Upper 

 Lower 

 Upper 



> Silurian. 



Devonian or 



Old Red 



Sandstone. 



Silurian. 



Cambrian. 



Cambrian. 



Lower / 



> Laurentian. Laureutian. 



Primary 



or 

 Palseozoic. 



Palaeozoic. 



J 



Natural Orders to which Fossil Plants belong. 



The plants found in different strata are either terrestrial 

 or aquatic, and the latter exhibit species allied to the salt and 

 fresh water vegetables of the present day. Their state of 

 preservation depends much on their structure. Cellular plants 

 have probably in a great measure been destroyed, and hence 

 their rarity ; while those having a woody structure have been 

 preserved. The following is the number of fossil genera and 

 species, as compiled from Unger's work on Pala3ophytology — 

 (linger, Genera et Species Plantarum fossilium, 1850). 



