TO 



SIR CHARLES LYELL, Bart., M.A., F.R.S., Etc. 



My dear Sir, 



After an interval of twelve years, it 

 affords me much pleasure to renew tlie dedication of this 

 work to you ; and in doing so to repeat my grateful ac- 

 knowledgments, for the kind aid and encouragement extended 

 to me as a young geologist, and for the friendly interest 

 which you have ever manifested in the labours of my riper 

 years. 



I am. 



With sincere gratitude and respect. 



Yours faithfully, 



J. W. DAWSON. 



