In the early half of 1922 a boring (“jumped”) was made by Mr. H. G. Godwin, of Quenington, Fairford, Gloucestershire, for Mr. Oswald Collier, of Calcutt, in search of water. The site of the borehole is at Calcutt—¼ in. above the “C” in Calcutt on 6 in. map, 5 S.W., Wilts.

The object of this paper is to deal more fully with the occurrence of Daviesiella llangollensis (Dav.) in the Carboniferous Limestone of Derbyshire, and further to make some observations on the sequence in the Midland area. In a later paper I hope to deal with the horizon of the “Brachiopod Beds”.

The examination of the fossil fauna, the chief forms of which are shown in Tables I and II and Fig. 1, shows that the beds commence at a high horizon of the Seminula Zone and extend to the top of the Dibunophyllum Zone. Also, the “life-zones” established by Professor Garwood in his North-Westem Province Paper can be readily recognized in our area and the series includes the sequence from the Nematophyllum minus sub-zone of the Productus corrugatohernisphericus Zone to the Dibunophyllum muirheadi sub-zone of the Dibunophyllum Zone. It can further be established that the limestones of our area do not persist up the horizon of the Botany Beds with Aulina mtiformis S. Smith. The Saccammina Band occurs in our area, but Saccammina occurs also in the limestones immediately above and below. The Girvanella Band of the North-West Province has been recognized and forms a constant horizon throughout the area. It occurs associated with a calcitemudstone and never as a nodular bed. Other bands also appear to be algal. The Spiriferina cf. laminosa Band of Garwood forms a constant horizon between the Seventh and Sixth Limestones.

Liassic Irregular Echinoids are rare. The interest attaching to them is exceptionally great, and is enhanced by this rarity. Separation of Exocyclic from Endocyclic types can hardly have preceded the Rhaetic period; hence each Irregular form found in the Lias might be expected to display evidence as to the origin of its sub-class. It cannot be claimed that the few such genera known fulfil expectation. Plesiechinus (represented by P. reynesi) occurs in the “Charmouthian”; it is but little removed from “Regularity”, but the Bajocian species P. ornatus (whieh is locally abundant) seems “just as good” in that respect. Holectypus appears in the Toarcian with H. conquensis; its occurrence at this horizon gives a striking illustration of morphogenetic acceleration, and there by negation to hopes of “genealogical” evidence. Species of Galeropygus are recorded from the Upper Lias; orthodoxy would probably repeat the preceding sentence here, but vide infra. The case of Collyrites, recorded from deposits of Liassic age, must surely be compared with that of Holeclypus; for every feature of the Collyritidae is in violent contrast with “Regular” structures.

Heidelberg, a town of insignificant proportions, lies 30 miles due south-east of Johannesburg at the foot of the Zuikerboschrand, a range of hills running south-west towards the Vaal River and made up of the volcanic beds of the Ventersdorp System and of the Elsburg series at the top of the Witwatersrand System. Travelling south-east from the Zuikerboschrand, the whole of the Witwatersrand formation is traversed in descending order. The district, which extends south-west of Heidelberg to Goedverwachting, a distance of 20 miles, and south-east to Greylingstad, another 30 miles, has a complicated geological structure, the succession being disturbed by faulting, broken by numerous igneous intrusions and obscured by frequent outliers of the Karroo formation. It is well known to the mining community on account of the fact that a gold-bearing conglomerate bed has been worked profitably at the Nigel Mine since the earliest days of the gold-fields, while numerous other reef outcrops in different parts of the district have induced much active prospecting, which has continued to the present day.

Last summer we spent seven days with Mr. E. B. Bailey investigating some of the evidence upon which he bases his interpretation of the structure of the South-West Highlands, and we feel that our experience should be at the disposal of others interested in the subject. Mr. Bailey's full account of his theory will shortly appear in the Quarterly Journal of the Geological Society of London, and an abstract has already been printed in the Proceedings of that Society, dated April, 1921.

The lavas which cap the Karroo beds of Southern Africa have general interest as indicating the eruptive activity prevailing at a time of complete quiescence in the European area. The sedimentaries immediately beneath them (Stormberg series) are of Rhætic or even Liassic age, so that the lavas themselves, which are many thousands of feet thick in the Drakensberg range, may confidently be ascribed to the Jurassic period.

The writer has thought it desirable, in the following observations, to embody the results of his examination, last September, of the Arnioceras-bearing beds of Ardnish, near Broadford in Skye. The strata yielded a number of Ammonites of the Upper Coroniceras, gmuentdensis, and Ætomoceras subzones, and belong chiefly to the “Shaly Beds” of division iv of the Broadford Beds of the Survey Memoir on “The Geology of Glenelg, Lochalsh, and the South-East Part of Skye” (1910). They are therein referred, as by Professor Judd in his well-known paper on “The Secondary Rocks of Scotland”, to the bucklandi and semicostatus zones. Judd, the founder of the zone of A. semicostatus, certainly, however, misidentified some of his Ammonites, besides confusing his Lincolnshire A. geometricus with Young and Bird's A. semicostatus of a much higher horizon. Similarly, the Rev. J. E. Cross, in his paper on the “Geology of North-West Lincolnshire” (Q.J.G.S., vol. xxxi, 1875), recorded A. semicostatus from both the lower Gryphcæa incurva beds and the higher Scunthorpe Ironstone, which presents close analogy with the gmuendensis-Ætomoceras-Agassiceras beds of the Harzburg Ironstone. In reality this Ammonite (Arnioceras semicostatum) occurs in a much higher zone than either of these Lincolnshire beds.

It is well known that the liquid inclusions commonly found in quartz, fluor-spar, and other minerals resemble in some degree those that occur in crystals of sodium chloride, alum, and many salts. Chloride of sodium in particular shows innumerable cavities of varying size, cubical in form (negative crystals), and generally containing an enclosed bubble, especially if heated gently after the crystals are formed. The smaller cavities show Brownian movement of the enclosed bubble in a very striking manner. (See Fig. 1, which gives a diagrammatic view of a salt crystal as seen through the microscope.)

It was noted by the Rev. C. Noury in 1886 that sedimentary rocks were found in a small coastal area to the south of Fort Pezerie, on the south-western extremity of Guernsey. Professor T. G. Bonney observed the same area independently in September, 1910, after describing it in field notes in 1888 as a closejointed and rather schistose diabase. The Rev. E. Hill in 1884 had also regarded the rock in this area as constituting a dyke-formed diabase.

The occurrence of iron carbonate as a part of the cement in the Pennant Sandstone is not extraordinary, when the large amount of entombed organic matter is taken into consideration. The presence of organic material and the products of decay, the so-called humus acids, acting as reducing agents, would aid in the formation of iron carbonate and prevent its oxidation. Much of this carbonate probably owes its presence to a metasomatic replacement of calcium carbonate. The granules of siderite may have been derived from rocks similar to those of the Lower Coal Series of South "Wales. The alkaline carbonates which hold the humic substances in solution would readily dissolve silica, thus becoming effective agents in the solution and redeposition of silica in the rock. A solvent of this kind would be formed by the impregnation of alkaline salts by carbonic acid.1 The occurrence of so much secondary silica in the rock is probably the result of a redeposition of silica from such a solution. No oxides of iron have been found in any of the numerous separations, either by means of heavy liquids or the electro-magnet; their absence is easily explained when we consider the strongly reducing environment of the deposition and consolidation of the Pennant Sandstone. The perfectly rounded globules of sphserosiderite may have been precipitated whilst the sandstones were being deposited, but more probably derived from the denudation of fireclays similar to those of the Lower Coal Series of South Wales.2 The dominant mineral chlorite, existing as perfect cleavage flakes, is entirely distinct from the secondary aggregates of chlorite in the rock, and was probably deposited in its present form. I have examined a powdered specimen of the Delabole Slates of Cornwall (Upper Devonian), and have found in it a large proportion of chlorite flakes, exactly like the detrital chlorite of the Pennant Sandstone. The very few flakes of biotite found show little trace of alteration. The paucity of heavy minerals indicates that the Pennant sediments had not a granitic source; they were mainly derived from pre-existing sediments which were rich in chert, had abundant chloritic material present, and yet were capable of furnishing fairly fresh biotite. Metamorphosed shales would account for the presence of cordierite and corundum.

Definition.—Shell large, elliptical, subquadrate; valves moderately convex; inferior margin very slightly curved, almost straight; posterior end well rounded above, truncated below and straight, meeting inferior margin at rather more than a rightangle; cardinal margin very slightly arched, nearly straight, but passing gradually into posterior margin; anterior end rounded. Beak large, rounded, prominent, subcentral, elevated above hingeline, incurved, not directed forwards. Umbonal ridge nanow, straight, running obliquely backwards to posterior lower angle of valve and causing a slight angulation of the surface. Shell ornamented with regular equidistant sharp concentric lamellose striæ about 30–40 in number, rather suddenly bent at an obtuse angle on crossing the umbonal ridge.

The geology of Jamaica compared with that of some areas of the earth's crust is neither very involved nor very difficult of interpretation. Considering the length of time that has elapsed since it was first studied and the easy accessibility of many parts of the island, it should be fairly well known and should form a key for the interpretation of the structure of the larger and less well-known islands of Haiti and Cuba, and also of Porto Rico and the smaller islands forming the group of the Greater Antilles.

In the course of recent investigations in the littoral Lias of South Wales and parts of Somerset the writer has frequently found that almost the only fossils in some of these deposits are species of Ostræa and Gryphæa, which occur in regular sequence and are of considerable value in correlation. On consulting the literature describing these genera it became apparent that the specific names have been frequently misapplied. From correspondence with other students of Liassic rocks it also appeared that there is some difference of opinion concerning the precise horizons at which such species are to be found.

The terms “ kame ” and “ esker ” have been applied in England to various mounds and ridges of sand and gravel. For some, such as those in South-east Essex either name is inappropriate, since they are not glacial deposits but are tide-formed banks of shelly sand. Most of the described English kames and eskers are clearly related to glacial formations, and their distribution and structure throw light on the later stages of British glaciation.

The great winged man-lions from Mesopotamia are some of the most conspicuous and most wonderful objects in the British Museum. When visiting that museum last September I was greatly interested as a geologist in examining the kind of rock of which they are composed. This rock is, I suppose, usually taken to be a granite, but it is not an igneous rock. On the contrary, it is of sedimentary origin, a felspathic sandstone (arkose or sparagmite) of very coarse grain, almost bordering on a conglomerate. In the most characteristic variety, from the palace of Sargon, the chief constituentis white quartz in lumps varying in size between that of a hazel-nut and an apple (see Fig. 1). These are embedded in a cement of coarse-grained sparagmite. A notable peculiarity is thatthe fragments of quartz have very irregular contours, giving the appearance of an invasion of the larger fragments by the groundmass. In other varieties (Palace of Assurbanipal) the fragments of quartz are smaller and may in some cases show no distinction from the quartz-grains of the groundmass.

When visiting the fireclay quarry of the Dominion Fire Brick and Clay Products Company at Claybank, Sask., during the summer of 1918, the writer noticed an occurrence of banded precipitatesin the fireclay of one part of the quarry. Through the kindness and courtesy of Mr. H. G. Love, Managing Director of the Company, a collection of some examples of the occurrence was made and forwarded to the writer for further examination.