In the Geological Magazine, 1865, Vol. II., p. 308, reference is made to the recent discoveries of Whitney as to the occurrence of Gold in rocks of California even of an age as recent as Cretaceous. These discoveries fully confirm my previous results in South America, yet the examination of a series of specimens recently sent me from California makes me communicate these few observations upon the relations of the gold-bearing rocks in question and some remarks on the views which I have expressed with reference to the geological periods at which gold has made its appearance in the crust of our globe.

This article will be devoted to the consideration of the indications of marine and fluviatile denudation furnished by the cliffs, gorges, valleys, and other phenomena, of some parts of Central and North Wales. With the view of collecting facts, the author, during April and May of the present year, resided successively at Builth, Rhayader, Aberystwyth, Dolgelley, Newtown, and Llangollen, so as to have opportunities for repeated observations; and the following notes refer chiefly to the neighbourhood of these towns and the intervening districts.

In the former paper I adverted to the evidence which the Thames gravel afforded, that the channel in which it was deposited opened out over the Wealden area, and the corroborative evidence which the East Essex gravel furnished of a similar state of things.

The next operculated species which claims our attention is the Calceola Gotlandica of F. Roemer. This species has been removed from the class Brachiopoda in a list of the Upper Silurian Brachiopods which I published in 1860. I now give my reasons for so doing (then but briefly indicated).