110 THE CANADIAN NATURALIST. [May 



Undoubtedly, however, it is possible to have a boulder clay with 

 marine remains. This may happen in two ways — (1) a glacier 

 may lap over the sea, and melting, deposit the striated stones and 

 mud which it has gathered on its course ; or (2) striated boulders 

 may be dropped from floating ice upon the mud beneath, and when 

 the sea-bottom is uplifted, there will be a boulder clay of marine 

 origin. 



Patches of boulder clay containing shells may thus occur along 

 the seaboard, as, for example, at Caithness, and on the east coast 

 of England; but these patches of marine boulder clay will be 

 newer than the clay at the base of the Clyde sections. Upon this 

 point I kope soon to submit a detailed argument to the Society. 

 Meanwhile, I remark, as a curious coincidence, that Dr. Dawson 

 pronounces the shells collected from an " indubitable instance of a 

 marine boulder clay" at Biviere-du-Loup, to be, on the whole, a 

 more modern assemblage than those of the Leda clay of Montreal, 

 which rests upon the boulder clay. 



Dr. Dawson gives one or two localities for fossils in " stony clays 

 of the nature of true till;" but in the greater part of his sections, 

 the fossiliferous beds are superimposed on the boulder clay, exactly 

 as in the Clyde sections. 



IV. Very curiously, a bed is noted beneath the boulder clay, 

 for which we have a Scottish equivalent. A peat deposit, with fir 

 roots, is found beneath boulder clay at Cape Breton, while at 

 Chapelhall, Airdrie, we have vegetable remains in the same 

 position — indicating the existence in both countries of land in 

 parts afterwards depressed beneath the sea and again uplifted. 

 The exact climate when this land existed, is believed by Dr. 

 Dawson to have been, at Cape Breton, that of Labrador — in this 

 country I believe it to have been such as to support the Elephas 



primigenius, whose remains have been found beneath boulder clay 

 (certainly) at Kilmaurs, and (probably) at Airdrie. 



V. The researches of the last few years have brought the Clyde 

 list of fossils into nearer relation to the Canadian list than has 

 hitherto been supposed. The Leda arctica from Errol is undoubt- 

 edly the L. PortlancUca of the Canadian beds. This species 

 occurs in such large quantities at Errol as to be characteristic of 

 that clay. The Astarte compressa of the Clyde beds is not identical 

 with A. Laurentiana, but often approaches exceedingly near to it. 

 Menestho albula has been found at Paisley. It is doubtful whether 

 the Menestho albula of the Canadian beds is Moller's species. Mr. 



