lyS The Irish Naturalist. July, 



and stratified claj- \Yhich are imbedded with the Boulder clay 

 and gravels, with other observations supporting this conclu- 

 sion of a similar purport. 



The microscopical examination which I have made not only 

 of the fossiliferous clays at Rockbrook and Larch Hill, but 

 also of Boulder clay from other localities, has led me to a very 

 different conclusion as to the origin of these clays. No doubt 

 there was in glacial times both elevation and subsidence. 

 First glacial striation, then depression, Boulder cla}^ and 

 marine organisms. 



When the writer refers to " the absence of shells from beds 

 of fine sand and stratified clay, which are imbedded with 

 Boulder clay" he might have added, "but in which other 

 marine organisms occur." It is the fine claj- which usually 

 yields Foraminifera in the greatest numbers. It was in such 

 interstratified cla}^, both at Larch Hill and also at Shellag, Isle 

 of Man, that Foraminifera occurred in such profusion. This 

 is also the case in recent marine sedimentary deposits, a soft 

 oozy sea bottom is more favourable to marine life, especially 

 to Foraminifera, than places that are more sandy and where 

 the run of the tides is stronger. 



Man}^ of the shells in Boulder clay were transported by ice- 

 bergs with vStones and rock fragments, but some of them cer- 

 tainly lived at the places where they are now found, and with 

 some few exceptions all the Foraminifera must have done so, 

 as they are usuall}^ as perfect and as fresh looking as recent 

 specimens brought up by the dredge. 



Nor can I agree with the writer that the Irish Sea and the 

 adjoining land was buried under such immense masses of ice. 

 Where did the vapour come from to form these masses of ice, 

 seeing that there could be little evaporation from such a frozen 

 surface % Even presuming such a glacier did exist coming 

 from the North Channel, its natural course would be south- 

 ward by St. George's Channel where there would be least re- 

 sistance, and not upwards over the land. 



I have examined microscopically 134 samples of Boulder 

 clay from various places in Ireland, England, Scotland, Canada, 

 and Novaia Zemlia, and in 102 of these Foraminifera have 

 been found. Specimens were got in all the samples, 16 in 

 number, which I received from Novaia Zemlia. These had all 



