THE Wi:.YLl>i:\ FORMATION'S. 



s;uulstonc of America be accepted, we meet ^ii.li the 

 iv mains of the feathered tribes. 



In these formations we discover animals belonging to 

 the class Mammalia, the amphitherium and the phas- . 

 colotherium, which appear to have resembled, in many 

 respects, the marsupial animals of New Holland. ; 



The wealden formations, which are the next in order 

 of position, are a series of clays and sands, with sub- 

 ordinate beds of limestone, grit, and shale. These have, 

 in some instances, been formed in the sea; bur they are 

 usually regarded as fresh- water deposits. All the older 

 rocks bear evident marks of marine origin, unl< ss .some 

 of the coal-measure strata may be regarded as otlier- 

 wise ; but nearly all the wealden series contai n the 

 remains of land, fresh-water, and estuary animals, and 

 of land vegetables. The creatures which we discover, 

 preserved, to tell the history of this period, arc nume- 

 rous, and have marked peculiarities to distinguish them 

 from those already described, or from any now existing 

 on the earth. We find land jsaurians of a lar^ kind, 

 and animals of all sizes ; even insects, of which a great 

 variety are found in the wealds. The remarkable 

 iguauodon was an animal which, even by the cautious 

 measurement of Professor Owen, must have been at 

 least twenty-eight feet long ; and this enormous lu'enture 

 was suspected, by Cuvier, and has been pro ved b\ Owen, 

 to have been an " herbivorous saurian for terrestrial 

 life."t Dr. Mantell calculates that no less than. *f venty 

 individuals of the iguanodon of all ages ]IUA> come 

 under his notice ; and the bones of a vast number of 

 others must have been broken up by the workm* ,i in 



* Report on British Fossil Mammalia : by "Richard O'?u, I'lsq., 

 F.R.S. ; British Association Reports, vols. xi. xii. 



\ Notice on the Iguanodon, a newly discovered fossil repUl- jrom 

 the sandstone of Tilyate Forest, in Sussex: by Gideon Mantel], 

 Esq , F.H.S., cS:c. ; Philosophical Transactions, vol. cx.v. i>. 170. 

 On the Structure of Teeth, fyc. ; by Professor Owen. 



