730 GEOLOGY. 



from eight separate parts of the respective skeletons, Dr. Mantell gave the following 

 as the dimensions of the former : 



Length from the snout to the extremity of the tail - . . - 70 ft. 



Length of the tail ........ 52$ 



Circumference of the body - ... 14^ 



Though these proportions have been much reduced by Professor Owen, we may still pro 

 nounce this reptile, with Cuvier, one of the most extraordinary animals yet discovered. 

 A considerable portion of a skeleton found in 1834 in the quarries of Kentish Rag, near 

 Maidstone, shows the animal to have flourished in the dawn of the chalk formation. 



Hylceosaurus. The first relic of this animal, termed the forest-lizard, was discovered 

 by Dr. Mantell in the summer of 1832, in a quarry of Tilgate Forest, a part of the 

 weald. Other specimens were met with in the same district in 1837, consisting of a 

 series of twenty-six vertebrae, having a total length of six feet, with dermal bones, or 

 thick scales and spines. This lizard is computed to have been about twenty-five feet 

 long, and resembled the living iguana in the fringe of spines along the back. 



It has often been said that truth is stranger than fiction, and we have a forcible illustra 

 tion of the statement in the facts disclosed by the wealds of Kent and Sussex, a district 

 through which the steam-engine now rushes with its train of passengers, by ancient 

 towns, and quiet villages, and grazing flocks, but in by-gone ages the estuary of a river 

 proceeding from a country occupied by giant reptiles, and clothed with a vegetation 

 answering to the luxuriance of our tropics. The estuary, the river, and the country 

 have vanished, but we have the memorials of their existence in the strata occupying the 

 site, in the organic remains collected from them laid up in the cabinet of the natural 

 philosopher, and in the fresh-water shelly limestone columns of our cathedrals ; and 

 some idea may be formed of the probable condition of the country through which the 

 waters flowed, which deposited the wealden group, and of its animal and vegetable pro 

 ductions. " Whether," says Dr. Mantell, in his " Illustrations of the Geology of Sussex," 

 " it were a continent or an island, may not be determined ; but that it was diversified by 

 hill and valley, and enjoyed a climate of a higher temperature than any part of modern 

 Europe, is more than probable. Several kinds of ferns appear to have constituted the 

 immediate vegetable clothing of the soil : the elegant Ily menopteris psilotoides, which 

 probably never attained a greater height than three or four feet, and the beautiful Secop- 

 teris reticulata, of still lesser growth, being abundant every where. It is easy to con 

 ceive what would be the appearance of the valleys and plains covered with these plants, 

 from that presented by modern tracts, where the common ferns so generally prevail. 

 But the loftier vegetables were so entirely distinct from any that are now known to exist 

 in European countries, that we seek in vain for any thing at all analogous without the 

 tropics. The forests of Clathrarits and Endogenitce (the plants of which, like some of 

 the recent arborescent ferns, probably attained a height of thirty or forty feet,) must 

 have borne a much greater resemblance to those of tropical regions, than to any that 

 now occur in temperate climates; if we attempt to portray the animals of this ancient 

 country, our description will possess more of the character of a romance, than of a legiti 

 mate deduction from established facts. Turtles of various kinds must have been seen on 

 the banks of its rivers or lakes, and groups of enormous crocodiles basking in the fens 

 and shallows. The gigantic megalosaurus, and yet more gigantic iguanadon, to whom 

 the groves of palms and arborescent ferns would be mere beds of reeds, must have been 

 of such prodigious magnitude, that the existing animal creation presents us with no fit 

 objects of comparison. Imagine an animal of the lizard tribe, three or four times as 

 large as the largest crocodile, having jaws, with teeth equal in size to the incisors of the 



