49 



close of the Palaeozoic epoch. All the rocks around us were then upheaved and 

 dislocated, and the igneous rocks of the Malvern hills were then erupted froua 

 earth's central bed. Similar changes took place throughout the world, for with 

 the close of the Palaeozoic period a new condition of things was about to dawn. 

 The seas of the Lias contain some new and remarkable forms of animal life, 

 and the land was frequented by some small Mammalia, and flying lizards, or 

 Pterodactyles flitted with expanded wing from tree to tree. The Oolitic rocks of 

 England, which form such an important feature in its geology, were now 

 deposited, and the Jurassic sea which flowed over a large portion of the area 

 which now constitutes modern Europe was studded with coral reefs throughout 

 its whole extent, and the remains of these reefs are seen in the Cotswold 

 Hills, in the Coralline Oolite throughout its entire length from Dorsetshire to 

 Yorkshire, and in the Portland beds of Tisbury, in Wilts ; and a like story is 

 told by the contents of the Jurassic rocks of France, Switzerland, and Germany. 



Reposing conformably on the Oolitic formations we find the next great 

 series, the Cretaceous deposits these, we observe developed in the rounded 

 downs of "Wilts, Berks, Bucks, &c. All these chalk rocks, like the Oolitic rocks 

 on which they rest, were marine deposits, and contain the Reptiles, Fishes, 

 Molluscs, Echinoderms, and other classes of animals that lived on the shores 

 or in the depths of the ocean. They likewise differed specially from the Jurassic 

 forms of the same classes, and possess a facies of their own, which the trained 

 eye of the palaeontologist detects at a glance. 



"With the close of the Cretaceous period all these animal forms passed 

 away, and then came the dawn of the Tertiary period, which commences the 

 third volume of the Rock Book ; in the basins of London and Hampshire and the 

 Isle of "Wight ; the older Tertiary beds may be studied, but they are too far from 

 our present subject to notice now in detail. 



I can only remark that in each of the formations which I have mentioned 

 to-day, we find forms of animal life which are quite special to them ; every 

 formation in fact is characterised by its own fauna, and specific characters are 

 much more limited than persons who take a general view of the subject suppose. 

 The deeper we study, and the more accurately we observe, the firmer is the 

 truth established in the mind of the palaeontologist, that every great formation 

 possesses its own species of animals and plants ; that some have had a longer 

 life in time than others, but that the life of all is limited in duration, and that 

 all the different formations of the Palaeozoic, Secondary, and Tertiary Rock3 

 are characterised by forms of life that are special to each great period of the 

 world's history. 



I wish to show you an interesting example of one class of phenomena 

 belonging to the Drift period, but before leaving this plateau permit me to point 

 out the evidence you have here of the great erosion or denudation of the surface 

 which has taken place by atmospheric agency. These Old Red Rocks have 

 been peeled and dissected out by the oxygen of the air forming new combi- 

 nations with the mineral ingredients of the rock masses, and the rain and frost 



