CHAP. XL 
DESCRIPTION OF THE ORGANIC REMAINS OF THE WEALD- 
EN, AND PARTICULARLY OF THOSE OF THE STRATA OF 
TILGATE FOREST. 
Before we enter upon the description of the 
fossils of the Wealden, let us consider what would 
be the nature of a delta or an estuary, formed by 
a mighty river flowing in a tropical climate, over 
primary and secondary strata, through a country 
clothed with palms, arborescent ferns, and the usual 
vegetable productions of equinoctial regions, and 
inhabited by turtles, crocodiles, and other amphi- 
bious and terrestrial reptiles. In such a deposit 
we should expect to find sand more or less con- 
solidated, with layers of clay and silt ; containing 
water-worn fragments of the harder portions of the 
rocks, in the form of pebbles or gravel ; bones, 
teeth, and scales, more or less rolled, of the am- 
phibia that had lived and died on the borders of 
the river, and had been transported down its waters ; 
the branches, and stems, and leaves of the vegetables 
that grew on its banks, intermingled with fresh 
water shells, and a small proportion of marine pro- 
ductions ; a few bones of aquatic birds might also 
probably be observed. The strata of the Wealden 
present precisely such characters, and such an 
assemblage of animal and vegetable remains. 
