118 Proceedings. 



covering of the beak, but bony teetb growing from grooves in 

 the jaws, and these are essentially reptilian. It is worthy of re- 

 mark that it had none in the premaxillse ; and in the bird-like 

 reptile, the Iguanodon, there waa likewise an absence of teeth 

 in those bones ; though this coincidence is of no importance 

 whatever, as it can only be regarded as a trivial character. 



I have mentioned several Cretaceous genera which are not 

 found in the Tertiary Epoch which followed, and one might 

 think that a sudden catastrophe had overtaken these forms 

 of life ; as although we see the lowest Tertiary beds 

 lying directly on the chalk, we find no trace of them in any 

 part of the Tertiaries, and to the earlier geologists it appeared 

 as if in the new strata an entirely fresh type of beings had 

 suddenly come into existence. But we now know that there 

 is no such thing as a universal break in the stratified deposits. 

 If in any particular region of the globe a period of time is not 

 represented by the formation of a stratified deposit, that 

 period must have been occupied in denuding strata already 

 formed there ; but deposits must have been forming some- 

 where else, and it is in these intermediate beds that we find 

 intermediate forms of life ; and although such a marked 

 hiatus seems to come between our Cretaceous and Tertiary 

 formations, recent researches have shown that dui'ing that 

 period, represented only by denudation here, a series of beds 

 were being laid down in America in which we can trace the 

 gradual merging of the Fauna of the one into the Fauna of 

 the other. 



And now we have ascended the chalk hills and look north- 

 ward towards the overlying Tertiaries of the London Basin, 

 but at these I will stop. In this paper I have endeavoured 

 to illustrate a few of the leading principles of Geology by 

 means of the local strata, and I should feel gratified if, in the 

 course of it, I had given to those unacquainted with the 

 subject some particulars of interest. 



A discussion followed, in which Dr. Bossey stated that Dr. 

 Cooke reckoned it would take ten days of twelve hours each, 

 at the rate of sixty a minute, to count the Forams. in one 

 ounce of chalk. 



