Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/409

From Wikisource
Jump to navigation Jump to search
This page needs to be proofread.

wich Crag being more recent than the Red Crag, and its shells of an arctic or more northern kind. Tellina balthica he regarded as significant of brackish-water conditions. Actoeon Nooe, a characteristic shell of the Red and Norwich Crag, had been found fossil by Prof. Steenstrup in Iceland.

Sir Charles Lyell had been struck with the similarity of the beds at Chillesford and at Aldeby, in which also the shells, though 40 in one case and 70 in the other, were very similar in character ; but in neither was Tellina balthica found, though common in the glacial beds. He called attention to the condition of the shells as they occurred at Aldeby, and suggested that where the two shells of a bivalve were found in contact, they would probably afford some evidence whether they were derivative or not.

Mr. Searles V. Wood, Jun., was inclined to differ to a large extent from the author, especially with regard to the beds above the Chillesford clay. The sands containing Tellina balthica he placed as the lowest member of the glacial series ; the fauna they contain is different from that of the Chillesford bed. He regarded the sand-beds at Kessingland as above the lower Boulder-clay and contorted Drift of Cromer, and considered that it might be traced as occupying this position along a great part of the coast of Norfolk. He had, in company with Mr. Harmer, surveyed a great part of the Norfolk and Suffolk district, and they intended to place their maps and sections at the disposal of the Geological Society. He recommended that any examination of the country should commence from the east rather than from the west.

Mr. Boyd Dawkins, speaking of the fossil mammalia of the Crag, mentioned that, at the base of the Crag at Horstead, immediately on the Chalk, was a bed exhibiting an old land-surface, and in this were found the principal perfect mammalian remains, whereas in the Crag above they were waterworn. But though these bones occurred in the marine deposit, the animals had lived on the land, and there was no evidence but that they belonged to a much earlier period than that at which it was submerged. He thought that the facies of the Cervidae found at Horstead was that of an early Pliocene age. The mammals of the London Clay had in some cases become confounded with those of the Suffolk Crag ; but these he regarded also as belonging to an old Pliocene land-surface. He differed from the author in not regarding the forest-bed as Quaternary, as the remains of Rhinoceros etruscus, Ursus arvernensis, and Elephas meridionalis, &c. had occurred in it in many cases in fine condition. He could see no reason for splitting up the Cainozoic series into four divisions, as there was no break in the life between the Tertiary and Quaternary periods. Though there might be a break in England, the forms of life were continuous from the Miocene of Pikermi on the Continent.

The President suggested that if we were to admit a Quaternary period we must go back to the Miocene, as the mammalian fauna of that period was the direct ancestor of that of the present day.

Mr. Prestwich, in reply, remarked that he did not quite agree

x2