106 PROCEEDINGS OK THE GEOLOGICAL SOCIETY. 



US with an association of forms so entirely analogous to those now 

 existing, as to leave no grounds for assuming that the now prevalent 

 forms of foliage amongst Dicotyledonous plants did not predominate 

 hefore the glacial epoch, posterior to which all the existing British 

 plants, except the alpines, were introduced into our island, as has 

 been shown by Professor E. Forbes in his Essay on the Flora and 

 Fauna of the British Islands. I need hardly add, that the vegetation 

 of the Reading beds presents no affinities whatever with that of the 

 London clay. 



Observations on the Specimens. — Fig. 1 . is a very common form of 

 leaf amongst various classes of Dicotyledonous plants, but does not 

 exactly resemble any living plant with which I am acquainted. I 

 assume that the scar at its cordate base represents the point of in- 

 sertion on the stem, and that the leaf was therefore sessile. 



Fig. 2. resembles the foliage of many species of European, North 

 American, or North Asiatic Maples, but may be compared with 

 equal propriety to the foliage of so very many other genera and 

 natural orders that I cannot attach the smallest importance to the 

 resemblance. 



Figs. 3-8. 1 can suggest no resemblances for them that are worth 

 recording. Figs. 3 and 15 possibly belong to the same species. 



Fig. 1 1 . resembles a fragment of fern-frond, but equally well repre- 

 sents a portion of the pinnatifid leaf of a composite or umbelU- 

 ferous plant, and may indeed be referred to very many other natural 

 orders. 



Figs. 12, 13, 14. are veiy common forms of Dicotyledonous leaves 

 that do not suggest any particular analogies to me. 



Figs. lG-21. are quite unsuggestive to me. Of them, 18 may be a 

 portion of a pinnatifid leaf, or may be a fragment of the midrib, 

 &c. of a large entire leaf. 



Fig. 23. I have alluded to as probably indicative of a Monocotyle- 

 donous vegetation. 



Figs. 24-26. are finely-preserved buds of a Dicotyledonous shrub or 

 tree, but of what natural family it is impossible to say. Poplars, 

 Ericese, and many other orders have similar ones. 



Fig. 27. I can make nothing of 



Fig. 28. I am equally at a loss to miderstand. Seeds have been sug- 

 gested by one friend, and an insect's gall by another. 



Fig. 22. Were I assured that this was what it appears, a petiole with 

 two leaflets or lobes of a fan-shaped leaf, it would be curious ; but 

 I have been so often deceived on the one hand by appearances 

 assumed by fragments of foliage, &c. thrown into accidental juxta- 

 position, and on the other by the false analogies that imperfect 

 specimens suggest, that I cannot venture to give any opinion 

 about it. 



