STRATA OF TILGATE FOREST. 45 



7. The impressions of leaves, of a species of car ex or sedge ; per-, 



haps iris? 



These are frequent in the form of reddish brown stains, and im- 

 pressions ; similar remains also occur in the Stonesfield slate*. 



FOSSIL SHELLS. 



These, with but one exception, occur only in the state of casts or im- 

 pressions; and their characters are so imperfectly defined, that it is 

 scarcely possible to ascertain the genera and species to which they 

 belong. 



8. Y'lw'v^divai fluviorum ? perhaps PaludmcB? 



These are apparently similar to the shells of the Petworth marble, 

 figured in tab. XVII. figs. 5, 6. They occupy the lowermost layers of the 

 car-stone, and occur in groups of fifty or sixty, disposed in relief on the 

 surface of the stone, where the latter is in contact with the blue clay. 



9. Vivipara extensa, associated with the former. 



10. Casts of spiral univalves, of uncertain genera. 



11. Casts of two species of my a or unio. 



12. Casts of four species of transverse bivalves, whose generic cha- 

 racters cannot be determined. Some parts of the limestone contain a 

 considerable number of these nuclei, closely invested by the surrounding 

 matrix, no appearance of the space formerly occupied by the shells being 

 perceptible 'j'. The surface of the casts is smooth, and of a ferruginous 

 colour, spotted with stellular markings of a darker shade. 



REMAINS OF FISHES. 



The teeth, and perhaps the scales, are the only parts of fishes that 

 have been found in these deposits. The former, from their hardness and 

 durability, are in an excellent state of preservation, retaining their original 



* It is worthy of remark, that with the exception of fragments of charred wood, the vegetal 

 reliquise of the Tilgate hmestone and sandstone, consist exclusively of those which possess the 

 most simple structure, viz. the monocotyledonous, or acotyledonous tribes of plants. 



f This mode of petrifaction is termed redintegration. Vide page 50, Martins Outlines of 

 an Attempt to establish a Kno-iicledge of extraneous Fossils on scientific Principles, 8vo. 1809. 

 Macclesfield. 



