Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/199

 feet. inches.

Thin line of sand, with pyrites 0 1

Thin band of blue clay 0 4

Hard sandy clay, with thin lines of stiff clay 10 0 Ditto, with more clay 5 0

Stiff clay 5 0

Very stiff clay, with large Oysters 18 0 Zone of Ostrea gigantica.

Claystone 0 2

Very stiff clay 29 0

Layer of pyrites 0 1

Stiff clay 12 8

Claystone 0 2

Clay 2 0

Claystone 0 2

Very stiff clay 10 10

Clay, full of rounded black flint pebbles 0 9

Hard sand 22 3

Blue clay (to bottom of boring) 39 0

Discussion.

Prof. Ramsay called attention to the value attaching to such observations as those of the author on the nature of the superficial deposits as distinct from the older rocks on which they repose.

Mr. Etheridge observed that the presence of the Lingula determined the position of the Bognor beds in the series, though there appeared great difficulty in fixing it stratigraphically. The commingling of species exhibited in this instance, of shells hitherto supposed to be peculiar to certain horizons, he regarded as very remarkable.

Prof. Morris observed that the section seemed to show, not only the order of the beds, but their manner of deposition, the whole having formed part of a tranquil sea-bottom. He remarked on the difficulty of separating the more recent mud deposits from the beds of more ancient date. He pointed out the method of formation of septaria apparently by segregation, as -they sometimes included undisturbed parts of the beds. The number of bivalves bored by carnivorous mollusks was remarkable, as was also the absence of Pectunculus.

Mr. Gwyn Jeffreys observed on the habits of Lingula, which had been by some regarded as an annelid, and not as a mollusk. It afforded a curious instance of the persistence of species, as there was no distinction that could be established between those of the Crag and of Silurian times. It lived at the present time between high- and low- water mark, and the Panopoea at a slightly lower level, and probably had done so in Tertiary times.

Mr. Evans inquired whether the upper gravel, like that on the shore of Southampton Water, contained any flint implements.

Mr. Meyer replied that he had not examined the gravels with that view.