340 



since Townsend's " Vindication of Moses," is still the only paper of 

 its kind. 



" Notes on the Age of the Limestones in South Devonshire." Fifth 

 vol., second series, "Transactions," p. 721. Ilarch 25, 1840. — 

 This is the most important communication Lonsdale made to the 

 Society, in consequence of which he has been called the founder of 

 the Devonian system. He begins — 



" The reasons which have induced me to assume on Zoological evidence that 

 the limestones of Southern Devon, between Dartmoor and the Coast, would 

 prove to he of the age of the old red sandstone, not having been placed on 

 record in a separate form, Mr. Murchison has begged me to lay before the 

 Society a distinct notice of my claim to having been the first to propose the 

 classification recently put forth by Prof. Sedgwick and himself, and in con- 

 sequence of an extension of those views to Belgium and the Boulonnais, Dr. 

 Fitton has urged mo to comi^ly with the request.* In the memoirs in which 

 Prof. Sedgwick and Mr. Murchison announced the change in their classifica- 

 tion of the older sedimentary strata of Devonshire and Cornwall the clearest 

 and amplest acknowledgments are made of my share in promoting the 

 alteration ; but as it is possible that some mistake may hereafter arise relative 

 to the nature and limits of my suggestion, I conceive it is a duty to others as 

 well as to myself to comply with the above request." 



He gives a notice of the writers .from Woodward (1729) down- 

 wards who have in any way geologically noticed these rocks, adding 

 a resume in each case where the observations are of any value. 

 The three papers he especially notices are these : — 



1st. — Prideaux, which is published in the " Transactions" of the 

 Plymouth Institution, of whom he remarks that his inference of 

 age was based on mineral characters alone. 



2nd. — Delabeche's, which was the first attempt to define the 

 Zoological character of the Devonshire calcareous rocks. The list 

 of fossils contains 21 species, and Lonsdale considered that 

 Delabeche was justified on such evidence in regarding the new 

 species rather as an addition to the fauna of the mountain lime- 

 stone than as an indication of a distinct period of organic life. 



3rd.^ — Mr. John Phillips. Out of a list of 38 species of Devon 



limestone shells 21 are marked as common to the transition and 



the carboniferous series, and the writer doubts to which formation 



these limestones belong. Lonsdale reminds that — " The Silurian 



* Lend, and Ed. PhU. Mag., April, 1839, p. 680. 



