66 THE TRIAS AND OOLITE. 



the south-east part of England was the mouth of a river of 

 that far-descending class of which the Mississippi and Amazon 

 are examples. What part of the earth's surface presented 

 the dry land through which that and other similar rivers 

 flowed, no one can tell. It has been surmised, that the par- 

 ticular one here spoken of may have flowed from a point not 

 nearer than the site of the present Newfoundland. Professor 

 Phillips has suggested, from the analogy of the mineral com- 

 position, that anciently elevated coal strata may have com- 

 posed the dry land from which the sandy matters of these 

 strata were washed. Such a deposit as the Wealden almost 

 necessarily implies a local, not a general condition ; yet it has 

 been thought that similar strata and remains exist in the Pays 

 de Bray, near Beauvais. This leads to the supposition that 

 there may have been, in that age, a series of river-receiving 

 estuaries along the border of some such great ocean as the 

 Atlantic, of which that of modern Sussex is only an example. 

 The zoology of the Wealden is chiefly remarkable for the 

 additions which it makes to the list of reptiles presented in 

 previous formations. Besides some new crocodilia (Sucho- 

 saurus and Goniopholis), and several chelonia (Tetrosternon, 

 etc.), we have here the principal constituents of a group, 

 which Professor Owen has described as a distinct order, under 

 the name of Dinosauria, the remaining form being the Mega- 

 losaurm of the oolite. These were terrestrial crocodile-like 

 animals, with some features of organization recalling the 

 lacertilia, and also such a massive and stately form of the ex- 

 tremities, as to remind us of the large land pachyderms. The 

 animal last named, from twenty-five to thirty feet long, with 

 an enormous muzzle furnished with strong teeth, must have 

 been by far the most formidable land creature of its age. The 

 very opposite habits of the Iguanodon, an equally huge herbi- 

 vorous reptile, lead me to suspect an error in the classifica- 

 tion : but passing from this its size and stately limbs are 

 such as equally to excite our surprise. From the scapula or 

 blade-bone of the remaining genus, the Hylceosaurus, the ap- 

 proximation of the whole of the dinosaurs to the mammalian 

 type of structure has been inferred. 



