Xll INTRODUCTION. 



E. Odontopteris. Pinnules adhering to the rachis by the whole of their 

 base; mid rib none; secondary ribs running out perpendicularly from 

 the rachis. 



12. Sphoenophyllites. Leaves verticillate, wedgeshape, truncate ; ribs 

 radiating, two forked. 5 



13. Asterophyllites. Leaves verticillate, with a single rib. h 



14. Fucoides. Frond not symmetrical, often disposed on a flat surface ; ribs 

 none, or badly defined. 



15. Phyllites. Leaves with ribs well defined, repeatedly divided, or anas- 

 tomosing.' 



16. Poacites. Leaves linear ; ribs parallel. 



17. Palmacites. Leaves fan shape. 

 Class 4. Organs of fructification. 

 Order 1. Cakpolithes. Fruits or seeds. 

 Order 2. Antholites. Flowers. k 



Great Britain is so fertile in the remains of the plants existing at the moment of 

 that great catastrophe which has preserved them for our inspection, that it would 

 appear nearly every species of fossil plants mentioned by these authors is to be 

 found in it; although at present our knowledge of them is very limited. 



This work is intended to extend these limits ; and to exhibit a comprehensive 

 illustration of these stupendous relicts of the early vegetable creation. 



The progress of this inquiry has led to the formation of several new genera, and 

 the introduction of species which were unknown before; and it is not improbable 

 that in the course of a further investigation of these fossil plants, the author may 

 have occasion to institute genera that will in some degree interfere with the prin- 

 ciple on which the characters of the present genera are founded. Such observa- 

 tions, therefore, as ought to have been, perhaps, more properly made here, will be 



s M. Brongniart is inclined to consider that these belong to some extinct genus of plants, allied, 

 although perfectly distinct, to the recent genus marsilea. 



" These the author thinks are the remains of an extinct genus of plants. 



1 The character here given of the ribs, necessitates these leaves to have belonged to the plants of the 

 dicotyledon tribe; as those of the next genus poacites equally restricts them to the other great tribe of 

 monocotyledon plants. 



k These orders are too little known to be divided at present into genera. 



