Three years ago when I was discussing certain Carboniferous Corals from Arctic regions the opinion was expressed that the genus Lophophyllum of Milne-Edwards & Haime had been erroneously interpreted by palæontologists, and that in reality it included Thomson and Nicholson's well-known genus Koninckophyllum The main object of the present communication is to substantiate this view with illustrative sections from topotypes, accompanied by some further observations on the genus. At the same time the opportunity is taken to deal with several points in the morphology of the similar genus Cyathaxonia; in the latter case the work is in the nature of a preliminary note rather than of a formal revision. Pending the appearance of a general memoir on the British Carboniferous Corals, it seems desirable that these notes should be published without further delay, as all these genera are commonly met with in zonal work. Most of the material has come either from the Geological Survey Collection or is in my own possession, but Dr. Vaughan has always been very helpful, while I have to thank Dr. T. F. Sibly for some unusually fine examples of Cyathaxonia from Matlock. Other specimens of this genus, from Yorkshire, have very kindly been sent to me from time to time by Dr. A. Wilmore, often at some personal inconvenience.

In the Geological Magazine for July and August last Mr. A. J. Jukes-Browne made a proposal for the recognition in England, France, and Germany of a boundary-line between two corresponding stages in the middle of the old zone of Actinocamax quadratus. The reception to be given to this proposal so far as it concerns France and Germany must be a matter for the geologists of those countries, and I am concerning myself chiefly with the proposal as it affects the English Chalk. Inasmuch as I sympathize with the proposal, and my own work is partly relied upon, it may seem ungracious in me to criticize it, but there are several points on which criticism seems desirable if only to afford Mr. Jukes-Browne an opportunity of replying while the subject is still fresh.

In 1908 Mr. R. H. Worth described a number of stones which had been dredged by Mr. T. R. Crawshay, of the Marine Biological Association, from the floor of the English Channel to the east and south-east of the Lizard. These stones included a great variety of rocks such as granites, felsites, diorites, and other igneous rocks, gneisses, schists, slates, and quartzites, Devonian grits, Permian conglomerate, Triassic marl, sandstones of different kinds, Liassic limestones, hard chalks, and flints.

In attempting an explanation of the structure of Western Cornwall it seems fairly evident that the first step should be a study of the coast sections, for the interior of the country is so folded and buckled that it is quite bewildering in its complexity. The natural sections most useful for this purpose are those of Black Head to Gorran Haven, St. Michael Carhayes to the Dodman, Falmouth to the Manacles, and Trewavas to Mullion, since all these sections cross the lines of strike more or less at right angles. It soon becomes abundantly clear that the complexity of folding exhibited by the rocks is but the detail of greater movements and need not seriously detain us. In 1908 Upfield Green expressed our views on those greater movements in the ninety-fifth report of the Trans. Roy. Geol. Soc. Cornwall, and endeavoured to show that the great Hercynian movements had involved Cornwall, throwing the country into three east and west anticlinals with sinuous outcrops, which anticlinals had gradually been forced over to the north into overfolds. These folds have been further complicated, distorted, and confused by local minor bucklings shown by the strata on every side.

This district is bounded on the north by the Coalville and Ashby line, on the west and south by the county boundaries, on the east by the Shackerstone and Market Bosworth lines. In the north are exposures of Coal-measures, Permian breccias, and Bunter, which the Trias in turn rests upon unconformably. The Lower Keuper forms a long tract on the west not more than two miles in breadth, forming a good feature, the sandstones giving rise to scarps, whilst the Red Mail occupies the rest of the district to the east. On the south-west beds of sandstone form marked features, which also give rise to bold escarpments, whilst the Red Marl itself constitutes a uniform plateau with little or no variation in heights. There are few exposures in the marls, which on the extreme east are covered by a mantle of Boulder-clay and sands. The River Sence and the Sence Brook, however, cut down to the lower parts of the Red Marl, and a good deal of alluvium fills the valleys to the south. The altitude over most of this ground rises uniformly above 300 feet, and in some parts to over 400, rarely sinking below 250. A ridge of hills is formed by the Orton Sandstone striking north-west and south-east, and another ridge meets it at right angles from Market Bosworth.