Notices and Extracts from the Minutes of the Geological Society. 421 



I have at my command. From the great readiness with which even a very 

 diluted acid took up the whole of the lime, its combination with the silex must 

 have been purely mechanical. 



The mass of the chalk in which the nodules were imbedded, affords scarcely 

 a trace of siliceous admixture, though such an admixture may be found occa- 

 sionally in the thick white crust with which some of the flints are invested ; 

 in this case, however, the silex forms by far the larger portion of the mass, and 

 the lime appears somewhat more intimately combined with it. 



>7. — Description of some Fossil Vegetables of the Tilgate Forest in Sussex. 

 Mr. Mantell, M.G.S., of Lewes in Sussex, having favoured the Society 

 with a collection of fossil vegetable bodies from the Tilgate forest, near Cuck- 

 field, in that county, some members of the Council were appointed a committee 

 to describe and publish them in the Transactions. In the prosecution of their 

 labours, they have to acknowledge the invaluable assistance which has been 

 liberally afforded them by our celebrated countryman Mr. Robert Brown. 

 — The following information as to the locality of the fossils has been com- 

 municated to us by Mr. Mantell. 



" The strata of Tilgate forest consist of various layers of sandstone and 

 schistose calcareous sandstone lying on a bed of blue clay of considerable thick- 

 ness. They emerge from beneath the upper beds of the iron sandstone ; 

 and the blue clay, on which they repose, is succeeded by beds of that forma- 

 ^ tion. They traverse the county of Sussex in a direction nearly north-east 

 m and south-west : Horsham being their western, and Hastings their eastern 

 ^ boundary. The following section of a quarry in the vicinity of the forest 

 will serve to convey a general idea of the whole. 



" 1. (The lowermost bed.) A blue tenacious clay, destitute of fossils, depth 

 unknown. 



" 2. Compact blueish gray sandstone divided by horizontal seams of blue 

 marl, into layers from 3 to 12 inches in thickness. This bed is about 

 9 feet thick. It contains the bones of two species of turtle, of a crocodile, 

 a plesiosaurus, a megalosaurus, a cetaceous animal, probably a whale, of birds, 

 and the vegetables about to be described. The upper layers are a compact 

 conglomerate ; but the lower are perfectly homogeneous, and contain shells, 

 such as are found in the Sussex marble, and figured by Sowerby as a Vivi- 

 para. 



" 3. Yellow sand and soft calcareous sandstone, alternating with thin layers 



VOL. VI. 3 I 



