There is a lead-zinc (with subsidiary copper) metallogenic province on each side of the Vale of Eden. To the east the veins of the Alston Block are found in Carboniferous rocks and a Hercynian age is the generally accepted date of the mineralization. To the west the veins lie in the Lower Palaeozoic rocks of the Lake District. Within the latter area ore-veins associated with the Shap Granite are, by common consent, regarded as of Caledonian age. But these apart, there is a regional mineralization in the Lake District, best developed in the northern part of that topographical unit, which has also been regarded as of Hercynian age.

Although there are in existence numberless books, many of them of great excellence, dealing with the effects of denudation (Geomorphology) nevertheless long experience and much reading seem to show that the more descriptive side of the subject, the result of the processes, has received more attention than the actual mechanism by which the results have been brought about. This applies more particularly to river erosion. In most books there is at the outset a tacit assumption that rivers do erode and the matter is left at that. Now rivers and running water generally certainly do perform the work of denudation somehow, as is proved beyond doubt by the large amount of material sometimes carried in suspension. But a careful consideration seems to show that the subject is not quite so simple as would appear from most textbooks.

Some eight or nine tracts are now recognized. At Bangor there are two, and an isolated one at Carnarvon;the rest are in the Tregarth country. On the older one-inch maps, all of this was coloured as Cambrian, but during the “25-inch” survey, the greater part of it had to be transferred to Arvonian, reducing the Cambrian to a group of outliers.

The existence of pillow lavas, black shales, and cherts in North Glen Sannox, Arran, has been known since W. Gunn carried out the detailed mapping of this part of the island for the Geological Survey in 1899. A description of these rocks, in which that author makes the suggestion, not since seriously disputed, that they are of probable Arenig age (Gunn, 1900) was first published in the Summary of Progress for 1899. Full accounts, to which the reader is referred for details not repeated in the present paper, were later given by Gunn (1903, 1905) and by Tyrrell (1928).

Through the courtesy of the Ministry of Information and of the military authorities in Naples, the Department of Mineralogy and Petrology, Cambridge, have received samples of the latest ejectamenta from Vesuvius—lava, probably from the neigbourhood of S. Sebastiano, and ashes and lapillae from Salerno.

The tendency among some modern authors to suppress the well-known genus Stephanoceras, Waagen, 1869, is due to sundry misconceptions, combined occasionally with a complete disregard of the Rules of Nomenclature. This raises matters of general interest, and thus a review of the vicissitudes of that genus and a discussion of some related questions may be acceptable to all palaeontologists.

The Shunner Fell Limestone is one of a group of calcareous shales and impure limestones, in all about fifteen feet thick, occurring in beds of Namurian age and Millstone Grit facies exposed on Shunner Fell, Wensleydale. The presence of Anthracoceras glabrum s.l. Bisat in these beds (Chubb and Hudson, 1925, p. 262) assigns them to the Arnsbergian (Upper Eumorphoceras Age, E2, Hudson and Cotton, 1943). Other fossils include small cornute corals, trilobites, gastropods such as Bellerophon and Euphemus, and brachiopods such as Athyris, Chonetes, Lingula, Schizophoria, Spirfer, and the spinose Productids. The occurrence of these beds and some of their fossils has been recorded by Goodchild (in Dakyns and others, 1891, p. 145), King (1914), and Chubb and Hudson (1925).

As a result of a recent controversy not itself directly palaeontological, the graptolite zones of the Ludlow have come in for much implied criticism (e.g. Jones, 1937, p. 280). Unless this criticism is faced, the well-known zonal work of E. M. R. Wood (1900) will sooner or later fall into disrepute, and a considerable volume of stratigraphical work on the Upper Silurian of North Wales will likewise share this fate.

The collection of Upper Devonian trilobites which Whidborne studied and described or figured is a small one, but most of the figured specimens are in the Sedgwick Museum, and though generally they are in poor preservation he was able to determine the species to his satisfaction. However, since his Monograph appeared (1896) a considerable amount of work on Devonian trilobites has been published, and the whole question of the Devonian or Carboniferous age of part or all of the beds from which they came is still unsettled. The evidence of the trilobites is somewhat contradictory, the genus Phacops and its subgenera being usually considered to range up no higher than the Devonian, while Brachymatopus has been regarded in the past as restricted to the Carboniferous. Whidborne recorded also a species of Phillipsia from the Upper Devonian, but as will be pointed out in this paper the evidence of the specimens is against this generic reference. The precise horizon and exact locality unfortunately were not given by Whidborne in the case of his figured specimens, the name of the town, village, or road only being stated, and this is unsatisfactory, particularly in those instances where it is of great importance to know the definite horizon or bed from which they were obtained, for the lithological characters of the matrix or mode of preservation is usually insufficient to determine it.

The limestone xenoliths about to be described were collected on the eastern side of Barnavave from a disused quarry situated at the junction between the “junction hybrids” and the surrounding Carboniferous limestone. The material comes from loose blocks left over during quarrying operations. Both the hybrids and the metamorphosed limestones have been dealt with in detail elsewhere1 and will only be referred to incidentally here.