366 THE WONDERS OF GEOLOGY. Lect. IV. 



posed by geologists to belong to a series of marine clays 

 and sands below the chalk.* 



Before entering upon the description of these strata, 

 I would remind you of the effects of rivers, and the nature 



* See Conybeare and Phillips's Outlines of the Geology of England 

 and Wales, pp. 140, 155. 



Although the shells forming the Sussex marble of the Wealden, 

 were supposed, so long since as Woodward's time, to be fluviatile 

 species, yet this point was controverted by many able conchologists ; 

 and few if any other organic remains, had then been obtained from the 

 strata of the weald. Having for several years diligently collected the 

 fossils of the chalk, gait, firestone, &c. in the south-east of Sussex, and 

 around my native South Downs, I was struck with the want of 

 accordance between them and some specimens of shells, bones, and 

 plants, I had procured from the quarries, wells, and cuttings made in 

 the Wealden district ; and by degrees, the fluviatile origin of the 

 deposits forming the area between the greensands of Sussex, Kent, 

 and Surrey, became manifest. The absence of ammonites, echinites, 

 terebratulce, corals, and other common and characteristic fossils of the 

 chalk, in my Wealden collection, was a circumstance that especially 

 arrested my attention : and the discovery of bones of large terrestrial 

 reptiles, with trunks and foliage of land plants, and of innumerable 

 river shells and crustaceans, in the strata of Tilgate Forest — of which 

 there were not the slightest traces in the cretaceous deposits, — corro- 

 borated the inferences suggested by my previous observations. In 

 1822, the Tilgate strata and their peculiar fossils were first described, 

 and the fluviatile origin of the deposits pointed out, in my Fossils 

 of the South Downs ; chap. vi. p. 37. In June of the same year, I 

 communicated to the Geological Society of London, an account 

 of the extension of these strata over the weald, being the result 

 of my own and Mr. Lyell's observations. In 1827, my Fossils of 

 Tilgate Forest appeared, containing nearly 200 figures of Wealden 

 Fossils. As the discovery of the fluviatile character of these deposits 

 has recently been attributed to other observers, I feel myself called 

 upon to state thus briefly the history of my humble labours; and to 

 corroborate it by the following quotations from Professor John Phillips 

 and Dr. Fitton. 



" Until the appearance of Dr. Mantell's works on the Geology of 

 Sussex, the peculiar relations of the sandstones and clays of the in- 

 terior of Kent, Sussex, and Hampshire, were entirely misunderstood. 

 No one supposed thai these immense strata were altogether of a 



