If historical earthquake data are to be used in studies of regional seismotectonics, it is essential to include information on likely locational uncertainty. Contributory factors include both geophysical parameters and the social environment of the event. A reconstruction of how a recent earthquake might have appeared had it occurred 300 years ago is used to demonstrate the effects of documentary survival. Limits of uncertainty are estimated for two historical earthquakes (7 October 1690 and 28 November 1880) and shown to be large. It is recommended that such events should be shown on epicentral maps as areas rather than points.

The Upper Greensand is a marine formation. Dr.Fitton, in his elaborate Memoir on ‘The Strata below the Chalk‘ (Geol.Trans., Second Series, Vol. IV.), has enumerated 60 species of Mollusca, 2 Annelids, 3Echinoderms, and 2 Protozoons from the beds in the South of England belonging to this period. These numbers have been more than doubled since the publication of that paper. They still retain the same proportions; but the fossils which Dr. Fitton characterised as ‘ fish remains ’ have been referred to 9 genera, and there have been added 4 genera of Saurians. As might be expected, very few vegetable remains have been observed. Dr. Fitton records the occurrence of some impressions of leaves. The remains of what appear to be sea-weeds are occasionally met with. Specimens of fossil wood have also been found. William Cunnington, Esq. F.G.S., of Devizes, who has kindly, through the Editor, furnished me with some particulars regarding the Upper Greensand deposits near Shaftesbury, informs me that for forty years he has been collecting the fossils of these beds, and that during that time he has obtained about thirty specimens of woods, many of them certainly drift woods, as they had been attacked by lithophagous molluscs. I have examined all the specimens of these woods contained in the collections of the British Museum, and I find that they are all Coniferous. Little more than this can be said. The woody fibres contain a single row of discs, and I have not detected any spiral fibres associated with them.

In re-arranging the large collection of Coal-measure fossils in the Manchester Museum I have had occasion to revise a number of species (notably in the Wild Collection) which have been recorded in the past under determinations which are now obsolete or erroneous. The object of this communication is to give a few critical remarks on these, as well as to place on record several hitherto unrecorded forms from the Lancashire Coal-field.

On the top of the cliff between Headon Hill and Widdick Chine, in Totland Bay, there is a Recent tufaceous deposit containing land and fresh-water shells. It extends along the cliff for nearly 350 yards in a north-easterly direction from the base of Headon Hill, and is about 60 feet above the sea-level.

It was first described by Mr. Joshua Trimmer, and subsequently by Professor Edward Forbes and Mr. H. W. Bristow. In the more recent memoir on the Isle of Wight the earlier descriptions are quoted, but the section is described as being then almost entirely overgrown.

Schists composed essentially of biotite and sphene have been found in many localities in the psammitic groups of the Moine Series in Ardnamurchan. From petrographic and chemical evidence it is concluded that they were heavy mineral bands, composed of sphene and iron oxides with a matrix which was partly pelitic and partly quartzo-feldspathic. This postulated original composition may have been produced by sedimentary slumping, for which field evidence is available. The unusual chemical composition was probably accentuated at higher grades of metamorphism by metamorphic metamorphic segregation, particularly a loss of soda or of segregation, particularly a loss of soda or of albite into the surrounding arkoses.

The following pages present some results obtained by me from the geological survey of the Fassa district in the Dolomites comprising the Bufaure and Monzoni mountain groups, where the porphyritic and monzonitic rocks are widely exposed. In selecting this district I had two objects in view—(1) to study in detail the tectonic relations between the igneous and stratified rocks; (2) to test the results which I had previously obtained from my survey of Sella Massive, etc.

Among the early Tertiary Fishes in the British Museum, there are a number of detached spines and cranial fragments from the Middle and Upper Eocene beds of Bracklesham and Barton, which are undoubtedly referable to extinct members of the family of Siluridæ. With the exception, however, of three specimens figured and briefly noticed by Dixon in his work on the fossils of Sussex, all have remained hitherto undescribed; nor is it an easy task to base any satisfactory identifications upon such fragmentary materials.

Since the publication in 1880 of Nicholson and Etheridge's monograph of the Ordovician and Silurian fossils from Girvan, no further work has been done on the coral faunas of that region. While engaged on a revision of the rugose corals as a whole, I have studied a part of the Gray Collection in the British Museum (Nat. Hist.), of which the present article is an outcome. I am grateful to the keeper of the Department of Geology, and to Dr. H. D. Thomas for the loan of material and for the kind interest shown in my work, and to Dr. Stanley Smith for his valuable criticism and advice. This work was mainly carried out in the Sedgwick Museum, Cambridge, and I take the opportunity to express my thanks to Professor W. B. R. King and Mr. A. G. Brighton for facilities for study. Dr. H. D. Thomas and Dr. O. M. B. Bulman both kindly read the manuscript.

Core material from carbonate cemented sandstones of Eocene age from the Maracaibo Basin, Venezuela, exhibits evidence of post-burial sideritisation of calcite. the process being identical in its essentials with dolomitisation. and resulting in a marked increase in porosity and permeability of the cemented sandstones. As a result of this increase, sub-surface waters have been able to leach out much of the sideritc cement, and subsequent mechanical compaction of the sandstones has produced a characteristic “bead”-like arrangement of remnant sideritc granules around the sand grains. The whole process can be reconstructed from thin-sections, and these are used to illustrate the text.

After I had forwarded the paper on “The Residual Earths of British Guiana commonly termed ‘Laterite’”, published on pp. 439–52, 488–95, and 553–62 of the GeologicalMagazine for October, November, and December, 1910, I visited the neighbourhood of Christianburgh and Akyma on the Demerara River in British Guiana and examined a small long-deserted quarry in a very fine-grained diabase intrusive in hornblende - granitite - gneiss near the latter pluce. I obtained from the lateritic earth lying on the mass of unaltered diabase a boulder of that rook in which the central parts were ideally fresh, whilst the outer parts were decomposed into laterite. I separated these parts with great care into an outer red one, apparently an ordinary ferruginous laterite, and an inner one, buff-coloured with whitish spots in it, which was in actual contact with the unaltered rock. When I obtained the boulder these crusts were quite soft, but after a few days' exposure to the air they hardened considerably.

Towards the end of January, 1937, an interesting discovery X was made at the sandpit belonging to the Headswood Sand and Gravel Company. The sandpit lies a little north of the point where the road from Larbert (Stirlingshire) forks for Dennyloanhead in the one direction, and Denny and Dunipace in the other. It is located immediately west of Headswood Farm, Stirlingshire (O.S. Sh. 24 S.W. 6 in. to 1 mile).

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.

In the year 1852 John Brown, of Stanway, published a paper on the Copford deposits (Q.J.G.S., vol. viii, p. 184), and in this includes a letter from George R. Waterhouse referring to two ‘Beaver’ teeth and the metacarpal of a Bear. One of these teeth is described and figured, and is said to differ from the beaver in being larger and also in the direction of the enamel folds. This tooth is preserved in the British Museum of Natural History at South Kensington, and I have recently had the opportunity of examining it; but the second tooth I have been unable to discover, concerning which G. R. Waterhouse says it “scarcely differs from that of the European species”.

THE study of recent sediments has yielded important data bearing on the extent and conditions of deposition in ancient seas, but the collection of similar data relating to the ancient continents is more difficult. However, one may find in marine deposits some indirect evidence of the constitution of the neighbouring continents. The effect of the proximity of deserts on the composition of recent marine deposits does not appear to have been studied. With a view to collecting data bearing on this particular point, I have made an examination of the deposits of the Red Sea.

HAVING already published a brief description of the accessory minerals of the granite in the neighbourhood of Dublin (1928) it had been the writer’s intention to make a study of the whole of the Leinster Granite giving special attention to the accessory minerals. As circumstances prevent the completion of this plan the following account has been drawn up, describing work done upon an area which extends from Dublin Bay to the neighbourhood of Aghavannagh, a distance of about 30 miles (compared with a range of 12 miles in the original paper) or nearly half the total length of the intrusion.

Mrs. E. Lort-Phillips, during her journey in Africa, collected some well-preserved Arca-like shells from a riverbed at Bihin, in Somali-land, which have been entrusted to me for determination. The specimens, belonging to one species, are of various sizes, quite black in colour, and covered in places with a lightish-brown matrix.

The petrographical and geochemical characteristics of some basic sills and dykes from Southern Rhenish Schiefergebirge are described. The dykes are generally more altered than the sills and are classified into two types according to their relation to the lead-zinc veins found in the area. The distribution of some trace elements in the sills and dykes is given and the nature and mechanism of alteration are discussed.