290 Limuean Society. 



of the progress of geology, and the important discoveries that have 

 recently been made. 



u The causes which have retarded the publication of a third edi- 

 tion it is unnecessary to mention : the delay has, I trust, been fa- 

 vourable to its appearance in a very improved state ; as 1 have been 

 collecting materials for it, during several years, having visited al- 

 most every situation of much geological interest in our own island, 

 from the Land's End in Cornwall, to the Grampian Mountains in 

 Scotland ; and passed part of three years in examining the geology 

 of Savoy, Switzerland, and France. There is scarcely a rock-for- 

 mation described in the present volume, that I have not examined 

 in its native situation, and compared with the descriptions of former 

 geologists. I have also had opportunities of examining the collec- 

 tions, and of profiting by the communications, of some of the most 

 eminent geologists on the Continent. 



" While engaged in these pursuits, I have not been inattentive 

 to the labours of other observers. So numerous and interesting are 

 the discoveries made in geology during the last ten years, that in 

 order to present a concise view of the science in its present ad- 

 vanced state, the * Introduction to Geology' has been recomposed, 

 and all the chapters are greatly enlarged. 



" The following new Chapters have been added : — Chap. n. On 

 Fossil Organic Remains. Chap. iv. On the Principles of Stratifica- 

 tion. Chap. x. A Retrospective View of Geological Facts. Chap. 

 xviii. On the Destruction of Mountains ; and on the Bones of Land 

 Quadrupeds, found in Diluvial Depositions and in Caverns. Chap, 

 xix. On the Formation of Valleys ; and on Deluges and Denuda- 

 tions.— The Plates are new, except Plate iv. and part of Plate vn." 



" In the course of the present work, I have frequently attempted 

 to elucidate the geology of England, by comparisons with situa- 

 tions I have examined on the Continent, in order to connect the 

 geology of our own island, with that of France, Switzerland, and 

 Savoy. 



" By comprising the numerous facts and observations contained 

 in the present volume, within the limits of an elementary work, from 

 the desire to be concise,- I may have run the risk of becoming ob- 

 scure: this I have studiously endeavoured to avoid; my chief aim 

 being to present the reader with a system of geology, which shall 

 explain geological phenomena in a clear and intelligible manner, 

 and as free from technical obscurity as the nature of the subject 

 would admit. In order that the price may not exceed that of the 

 last edition, this work is printed in a smaller type." 



XLIX. Proceedings of Learned Societies. 



LINN^EAN society. 



March 4. A COMMUNICATIONfrom the Rev. Leonard Jenyns, 

 -£Jl M.A. F.L.S. was read, On the distinctive characters 

 of two British species of Plecotus Geoff, supposed to have been con- 

 founded under the name of Long- eared Bat. 



A new 



