Page:Quarterly Journal of the Geological Society of London, vol. 26.djvu/186

 to find pebbles of rocks of various ages. He commented on the difficulty palaeontologists seemed to labour under in determining a fossil if it came out of a pebble instead of from a rock the position of which was definitely known. He adverted to the statement that the beds containing the pebbles had been deposited in the New-Red- Sandstone sea, whereas Mr. Godwin-Austen had regarded the New Red deposits as formed in large inland lakes ; and the local character of the beds supported this latter view.

Dr. Duncan defended the caution of palaeontologists, and remarked on the uncertainty attending the determination of casts.

Mr. Prestwich was glad that some other source had been suggested for the quartzite pebbles. He had found somewhat similar quartzites between Lisieux and Cherbourg, in France.

The President observed that he would like to see the rise of a new race of palaeontologists relying simply on zoological characteristics, and not on geological position. A considerable simplification of our classification would probably result.

Mr. Etheridge briefly replied.

2. On the Relation of the Boulder-clay, without Chalk, of the North of England to the Great Chalky Boulder-clay of the South. By Searles V. Wood, Jun., Esq., F.G.S.

Plate VII.

In a paper read before this Society by myself and the Rev. J. L. Rome, F.G.S., and published in the Journal, we described the Glacial clay of the Yorkshire coast as consisting of two main parts *. Of these, the lower, distinguished both in our sections and in the vertical section accompanying the present paper (see Pl. VII.) by the letter a, presents characters identical in all respects with the ordinary Boulder-clay, with chalk as its prevailing constituent, which forms the uppermost member of the Glacial series of the east and east centre of England ; while the upper (c) is a purple clay, in which chalk is only a subordinate constituent, even in the lower part, and which, gradually losing its chalk upwards, is in the upper part entirely destitute of it. We also endeavoured to show that, north of Flamborough Head, the whole of the clay, (which is destitute of chalk), belonged to this upper part only — and that, though lying at the foot of the northern escarpment of the chalk, as well as enveloping both the escarpment and the Wold, this clay, thus destitute of chalk, was not deposited until, by the complete submergence of the Wold, all source of chalk debris had been removed. We also suggested that the absence of any clay with chalk debris in these parts was due to their having been occupied by ice during the time that the clay containing that material was accumulated, and to this ice not having been removed until the Wold had been completely covered by the sea ; and we identified this chalk-

from the Glacial clay referred to in the paper, and is regarded by us as of Post-glacial age.
 * Vol. xxiv. p. 146. The Hessle clay there described is a separate deposit