i8o The hish Naturalist. July, 



rare, and include specimens in a perfect state. The presence 

 of perfect shells of Lcda was known long since to General 

 Portlock, and forced him to the same conclusion as arrived at 

 by the author, that the Boulder Clay is a marine sedimentary 

 deposit."' At Woodburn and Knock Glen, Co. Down, Lcda 

 7ninuta and L, pygmcea are usually found uninjured, and 

 often with valves united. Here, also, Foraminifera occur in 

 the very greatest profusion, too species having been found at 

 Woodburn, and 79 at Knock Glen, The Foraminifera in 

 Boulder clay are usually much smaller in size than recent 

 British species, but many of the specimens at these two 

 localities attain fairly large proportions. This, no doubt, is 

 due to these clays having been deposited in deep and quiet 

 water, below the disturbing influence of ice action ; it would 

 also account for the abundance of specimens, as well as for 

 the smaller proportion of stones in the cla3^ 



The occasional occurrence in Boulder clay of Foraminifera, 

 which are now onl}^ known as recent British species from 

 collections off the west coast of Ireland, and, in one or two 

 instances, off the west coast of Scotland, is of great interest. 

 Three of these species have been found in the clay at Wood- 

 burn, and five of them at Knock Glen. Some also have been 

 got at other localities, giving further proof that the Boulder 

 clay was in places deposited in deep water, where the marine 

 conditions must have been somewhat similar to what now 

 prevail off the west coast of Ireland. 



Should, at any future time, the sea-bed between I^abrador 

 and Greenland be raised above the sea, one can readily 

 imagine such a place to present very similar appearances to 

 those which we now find in Boulder clay. There would be 

 rock fragments and stones striated and scored by ice action, 

 associated with shells more or less broken with other material 

 that had been carried there by icebergs floating southward 

 from Arctic places, the rapidly melting bergs depositing their 

 burden over the sea bottom, and with these would be asso- 

 ciated mud and stones from the wearing of rocks in the 

 vicinity, as well as the marine organisms that lived at the 



place. 

 Belfast. 



■• Prrc. Belfast Nat. Field C/ui>.—App. 1879-80. 



