FOSSIL FEEiNS. 



287 



that subject. A great proportion of the lignite 

 in the laminated sands and clays forming those 

 cliffs, is undoubtedly the bark of the mature trees, 

 and the wood of the young plants, in a carbonized 

 state. 



But the coaly particles disseminated through 

 the strata have probably, in a great measure, 



lign. 21. — a fossil fern (Loncliopteris Mantelli) from the weald 



CLAY ; BROOK POINT. 



Fig. 1. — Portion of three leaflets, magnified, to show the reticulations of the 

 veins. 

 2. — Part of a stem, with leaves. 



originated from the foliage of two elegant extinct 

 species of ferns, that abound in some parts of the 

 Wealden of Sussex, and of which a few recog- 



