Page:Quarterly Journal of the Geological Society of London, vol. 27.djvu/231

Rh a basement bed with fossils and boulders of an unexpected and remarkable character (fig. 1).

(Unless mentioned to the contrary, all the pit-sections in this paper are on the same scale, viz. 12 feet to the inch vertical.)

The surface of the London Clay is here 8 feet above high-water level of the adjacent river Deben. Immediately on the London Clay we find a bed, from 1 to 1$1⁄4$ foot thick, of phosphatic nodules not to be distinguished in general appearance from those of the Red Crag. Among them I found, as in the Red Crag, a great many fossil Crustacea, much worn, derived from the London Clay, and consisting of the following species:—

With these I found one fragment of the horn of a Deer much mineralized, a small Cetacean vertebra retaining the ordinary bone-structure, together with numerous teeth of sharks. In the same bed were worn blocks of Septaria from the London Clay, drilled by boring mollusca, and flat, worn, highly mineralized Cetacean bones, superficially punctured, as those in the Red Crag, together with fragments of Bryozoa, Terebratula grandis, and Cyprina, much worn, and the latter full of the cavities made by minute boring sponges. With these organic remains there were a small number of the nodules or balls of coarse dark-brown sandstone, often containing the cast of a shell, so common in places in the Red Crag; there were also small pebbles of quartz and of flints, and some large pebbles of light-coloured, hard, siliceous sandstone: but the most remarkable specimen I there found was a rounded boulder of dark-red porphyry of considerable size, and weighing about a quarter of a ton. None of the specimens were angular or striated.

On mentioning these circumstances to Mr. Colchester, I found