110 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [ Dee. 8, 
at that time. Later than this, considerably, however, and when far 
larger tracts had become established as land, we get from the 
Hessle clay evidence that ice adequate to the transport of blocks of 
2 or 3 cubic feet in dimensions was in existence, though such 
blocks are but very rare in it. 
Discussion. 
Mr. Gwyn Jurrreys had found the shells of Kelsea and elsewhere 
in Yorkshire to be mainly arctic, and Mr. Prestwich, in his paper 
on the Boulder-clay near Hull, had first pointed out their glacial 
character. In the late dredgings in H.M.S. ‘ Porcupine’ several of 
the species before known as fossil at Bridlington, but not as existing 
in the British seas, had been discovered. In fact he believed that 
the Bridlington species, with but few exceptions, had now been found 
in the British seas. Similar species had also been found in the 
Boulder-clay in Scotland. 
Prof. Ramsay was pleased to find the author’s views so closely 
correspond with his own published some years ago as to the glacial 
phenomena of North Wales, though based on another part of the 
country. He thought that shells might be found by careful search 
in the low-lying Boulder-clay in other places than those enume- 
rated, as they had been discovered in the western part of England. 
Mr. Prestwicn, though inclined to accept the divisions of the 
Boulder-clay in Yorkshire as suggested by the author, was not so 
clear as to his divisions in the south. He thought the presence of 
chalk in the clay might be traced to the contiguity of the outcrop of 
the chalk stratum. The shells being to a very great extent recent, 
the grouping might be due to accidental or local circumstances. The 
Chillesford clays, in his opinion, marked the commencement of the 
great Glacial period. 
Mr. Erurrinet suggested that Nucula Cobboldie, Cardita similis, 
and some other shells not found in the British seas, proved the 
arctic character of the Bridlington fauna. 
Sir Coartes Lyrett remarked that if the fauna of the Lower and 
Middle Glacial really corresponded so closely with that of the Crag, 
it afforded a strong argument against their being of the same age as 
the Bridlington beds. Perhaps eventually some paleontological 
connexion might be traced throughout the series, and a chronolo- 
gical scale established. 
The Presipent suggested a difficulty in the marine transport of 
ice from Shap Fell to Bridlington, not only from the wind blowing 
rarely in the necessary direction, but from the current caused by 
the great submerged ridge also tending to carry any bergs in another 
direction. He thought the transport by sheet-ice more probable, 
The Rev. J. L. Roms had traced the Shap granites over the valley 
of the Eden, across Stainmoor to the Yorkshire side. There might 
have been difficulties in their transport, but there they are. Though 
they were found in Teesdale, yet the intervening ridge of millstone- 
grit, 2000 feet, had prevented their finding their way into Swale 
Dale. 
