86 



The Irish Naturalist. 



August, 



In these communications the writer brings out clearly, 

 that the Estuarine Clays overlie in many places a bed of 

 compressed peat which varies from one to two feet in thick- 

 ness, that the present day distribution of many of the 

 mollusca found in the Estuarine Clays indicates a warmer 

 sea than that which surrounds the north-eastern coast of 

 Ireland at the present day, and that in the Raised Beaches, 

 which may be regarded as contemporaneous with the later 

 series of the Estuarine Clays, occur large numbers of worked 

 flints of undoubted human origin. This deduction of a 

 warmer sea drawn from the presence of southern mollusca 

 in these beds is the more striking as the writer was not 

 acquainted with Scandinavian work and opinion on the 

 subject, and indeed most of the more detailed investigations 

 on the Climatic Optimum were undertaken after the dates 

 of publication of the papers quoted. 



During the publication of these results the author 

 ceased to reside in Ulster and later became specialized in 

 botany and undertook no further research into their contents ; 

 and as the opportunities for the study of the deposits are 

 practically dependent on the examination of the excavations 

 made for docks, harbour-works, bridges, etc., very little 

 work has since been done in connection with them. In 

 1900 a list of the marine mollusca of Ireland was published 

 by A. R. Nichols and from their present day distribution 

 it was possible to draw certain further conclusions regarding 

 the greater warmth, as compared with the present day, of 

 the climate of the Estuarine Clay period. When the Execu- 

 tive Committee of the Geological Congress in 1910 published 

 " Die Veranderungen des Klimas, seit dem Maximum der 

 letzten Eiszeit " no mention was made of these notable 

 contributions, which must be considered a most unfortunate 

 oversight. 



This large volume, which was prepared for the Eleventh 

 International Geological Congress held at Stockholm in 1910, 



lA. R. Nichols : A list of the Marine Mollusca of Ireland, Proc. Roy. 

 jnsh Acad., Series 3, vol. v, 1898- 1900. 



