The district known as the Wealdmoors of Salop is an ancient lake-basin about seven miles in length, by four in width. It lies east of the Wrekin, from which the ground slopes gradually down to it. On the S.E., the high ground of Lilleshall, and its vicinity, rises more abruptly, and on the N.E. extremity it is intersected by the river Tern, which probably formed the principal outlet. The centre of the basin is filled with peat, containing remians of oak and hazel trees, very much decayed, and matted together by thick layers of fibrous roots, and in the lower part, by a species of moss, of which the fibre is too fine for the Sphagnum, but which it is impossible to identify, on account of its decayed condition. This peat attains a thickness of about six feet. Some years ago, a bronze celt of fine workmanship, and which is considered to have been manufactured since the commencement of the iron age, was found imbedded in it.

The consideration of the subject of Denudation requires so extensive an acquaintance with Forms of the Ground in a field large enough to embrace all countries, that general conclusions must be advanced with more or less reserve, in proportion to the extent of our research.

It is well known that, though the Coal Fields of Lancashire and North Wales are now parted from one another at the surface by a broad tract of New Red Sandstone, there is reason to believe that the two are connected underground, and are bothparts of one and the same great deposit; and that the beds which in Lancashire and Cheshire dip out of sight below the Redmeasures, reappear in Flintshire and Denbighshire. Attempts have been made, I believe, to identify the individual coal-beds of the two districts, but I do not know with what success. During a short stay at Llangollen, some years ago, I venturedon a like task for the Lower Carboniferous Rocks, and though the time at my disposal allowed of only scanty observations, these were recorded in my note-book, in hopes that an opportunity might occur of filling in the sketch thus roughly tracedout. No such chance has befallen, or seems likely to befall me, and in the hope that the notes I then made may aid some one who, with more leisure, is willing to attempt a full solution of this problem, I now put them forward as a rough approximation.

By the able investigations of Mr. J. W. Salter, the various species of British Trilobites are now being systematically described, and referred to the genera to which they properly belong, the Asaphidœ with the rest; but there seems to be still some doubt as to the true differences between Asaphus and Ogygia. The feature apparently considered distinctive in the masterly work alluded to, is the form of the labrum; which, if furcate, is to be set down to Asaphus; if obtusely pointed, to be the distinguishing mark of Ogygia. How Ogygia peltata (Woodcut, Fig. 5) can be reconciled to this division, I do not see; but the main difficulty in the way of this classification is the sub-genus Ptychopyge of Angelin—distinguished by “having the facial suture within the margin in front.” This sub-genus Mr. Salter shows to be represented in Britain by Ogygia Corndensis, Murchison (Woodcut, Fig. 1): it is called Asaphus by Angelin, and has the wide axis, short and broad pleural furrows and simple caudal ribs of that genus. In addition to these features, the course of the facial suture finds a parallel' in the sub-genera of Asaphus, Isotelus, (Dekay) and Cryptonymus (Eichwald); Mr. Salter cites but one species of Ogygia that bears resemblance in this respect. Yet with all the stamp of an Asaphus, Ptychopyge Corndensis has the obtusely-pointed labrum common to Ogygia Buchii and O. Selwynii.