194 IRONSTONE OF THE WEALDS. EXTRAORDINARY ANIMALS. 



pebbles, and rounded pieces of Lydian stone and jasper, and con- 

 taining bones and teeth of fishes and saurian animals. The upper 

 sands are generally fawn-coloured, and contain lignite, bituminous 

 matter, and vegetable impressions. 



Ironstone occurs in considerable q-iantities in the Sussex beds. 

 In the sixteenth century, before the coking of coal for smelting of 

 iron ore was discovered, two thirds of ibe iron manufactured in Eng- 

 land was obtained liom the Sussex beds."^ The Wealds of Kent 

 and Sussex, being then covered with lorest trees, supplied the fuel 

 for smelting the ore. 



To the indefatigable and scientific researches of Gideon Mantell, 

 Esq., F.R.S., we are indebted for a knowledge of the true zoolog- 

 ical characters of the Wealden beds, which he has described in his 

 " Illustrations of the Geology of Sussex, with Figures of the Fos- 

 sils of Tilgate Forest." This work contains the most interesting 

 details of local geology which have appeared in this country. The 

 fossil remains of the Wealden beds consist of petrified trunks of large 

 plants, bearing a resemblance to the palms, arborescent ferns, and 

 the gigantic reeds of tropical climates ; also of the shells of fresh- 

 water genera, as the fresh-water muscle, the mya, cyrena, paludina, 

 and helix vivipara. Some remains of fish, and three distinct spe- 

 cies of turtles, have also been discovered ; and the bones, teeth, and 

 scales of at least five gigantic species of the lizard family; namely, 

 the crocodile, the plesiosaurus, the raegalosaurus, the iguanodon, and 

 the hylaeosaurus or forest lizard. 



The crocodilian remains are pronounced by Cuvier, to be almost 

 identical with those of the fossil crocodile discovered at Caen in 

 Normandy, which belongs to the genus Gavial, the crocodile of the 

 Ganges. 



The Plesiosaurus. — This animal has been noticed, Chaps. II. 

 and X. 



The Megalosaurus. — The bones of this animal, found at Tilgate, 

 are similar to those discovered by Mr. Buckland, in the Stonesfield 

 strata. The megalosaurus is supposed to approach nearer to the 

 form of the Monitorf than to any other species of living lizard ; but 

 its size is so enormous, that Cuvier says, if we suppose it to have 

 possessed the proportions of the monitor, it must have exceeded sev- 

 enty feet in length. 



The Iguanodon. — A nondescript herbivorous reptile, which Cu- 

 vier pronounces to be the most exti-aordinary animal yet discovered. 

 Its structure approaches the nearest to that of the Iguana, a large 

 species of lizard in the West Indies : its length was between sixty 



* For a knowledge of this fact, I am indebted to a gentleman who has in his 

 possession an ancient work on the iron trade of England, previous to the use of 

 coke. 



t The Monitor, — a species of lizard, which is said to give w^arning of the ap- 

 proach of the crocodile by a hissing noise. 



