Thrusting along a shear plane at the continental margins may result in a temporary up-bulging of the margins above sea-level. During the time of exposure erosion by streams should have incised canyons which now, after isostatic readjustment of the margins, constitute the widely distributed submarine canyons. Known downwarped peneplains below the surface of continental shelves may have been developed on the bulged margins by long continued erosion. The margins may, thus, have served as- sources of some sediments now found on land and believed to have been derived from a seaward direction.

In the Palæontology of the Vertebrata, so much has been accomplished on the American Continent within recent years, that any European interested in this line of research is naturally attracted to the Museums and collections across the Atlantic. Among others, the writer of the present notes has at various times been desirous of comparing certain American and Canadian discoveries with those now familiar to workers in the Old World; and this desire having lately been gratified, it may not be uninteresting to offer a few remarks on the collections of extinct Vertebrata in the New World, viewed from the standpoint of one who has had the privilege of visiting many of the corresponding collections in Europe.

Zoœcia large and pentagonal, average length about 8 mm., markedly crater-shaped (i.e. with side walls sloping inwards to a deep-lying areal opening): areas sub-pentagonal as a rule : side walls wide, sloping inwards practically all the way from the zooecial margin, the slope gentle in the lower half, then changing gradually to quite steep at the upper end; the two upper corners are occupied by a pair of stumpy perforated tubercles; just below the summit of the steep inward slope at the upper end of the arc, close to the corners and probably communicating with the external tubercles, are two pores so faint as to be hardly visible in full light.

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).

A study of Metriophyllum gracile has revealed some unusual features in its mode of attachment and growth.

This vomerine tooth was found by Dr. D. R. Kannemeyer when resident at Burghersdorp. It is the only evidence of the dentition of the animal known, and is interesting as being of much larger size than any Labyrinthodont teeth hitherto found in South Africa, though smaller than the large teeth of Mastodonsaurus giganteus from the Keuper of Würtemburg. Its presumed position on the palate is based upon the anchylosis of the tooth with a bone which shows a flat oblique suture at the base of the crown. This sutural surface is usual on vomerine teeth, and indicates that the tooth was directed downward, outward, and a little backward.

In March, 1912, a short paragraph in one of the London daily papers made the astonishing announcement that several beds of coal had been discovered on the Folly Farm, Presteign, and that boring would be started immediately. The astonishment was due to the fact that on the Geological Survey maps Presteign is represented as surrounded by Silurian and Old Red Sandstone formations, with no rocks of Carboniferous age nearer than the Clee Hills, 20 miles away in Shropshire. Unless, therefore, the Survey maps were wrong, and some unsuspected outlier of Coal-measures had been discovered, the name of the scene of operations was likely to prove prophetic.

Among the metamorphic phenomena which seem to me deserving of more attention than they have yet received, I have been especially interested by those existing in the brecciate formations. They are, of course, in the main, two-fold; namely, the changes of fragmentary or rolled-pebble deposits into solid rocks, and of solid rocks, vice versa, into brecciate or gravel-like conditions. It is certainly difficult, in some cases, to discern by which of these processes a given breccia has been produced; and it is difficult, in many cases, to explain how certain conditions ofbreccia can have been produced either way. Even the pudding-stones of simplest aspect (as the common Molasse-nagelfluhe ofnorth Switzerland) present most singular conditions of cleavage and secretion, under metamorphic action; the more altered transitional breccias, such as those of Valorsine, conceal their modes of change in a deep obscurity: but the greatest mystery of all attaches to the alterations of massive limestone which have produced the brecciated, or apparently brecciated, marbles: and to the parallel changes, on a smaller scale, exhibited by brecciated agate and flint.

The island of Sark lies 7 miles to the east of Guernsey. Its length from north to south is over 3 miles, and its average breadth is one and a half miles. The island is a table-land with an average height, above sea-level, of 300 feet, probably a result of marine planation of Pliocene date. Access is accomplished by scaling the cliffs of Havre Gosselin (west coast) or through the tunnel of Creux Harbour (east coast). The southern portion, Little Sark, joins the mainland by an isthmus 8 feet wide, 250 feet high, and 300 yards long, known as La Coup´ee. Here, as in many parts of the island, the cliffs drop sheer to the sea, and considerable care is required in examining the rocks.

The Cretaceous System of England, according to A. J. Jukes-Browne1 is “naturally divisible into two distinct and different series of strata”, namely a lower series consisting chiefly of sands and clays, and an upper series, consisting mainly of chalk. The succession on the whole is easy to unravel, and was correctly described (even before the name Cretaceous had been thought of) by Webster in his Letters, written in 1811 and published in 1816 in Sir Henry Englefield's Isle of Wight; it is almost exactly the same as we recognize it to-day. Two slight changes have been made, but they have been considered by some to be changes for the worse. Firstly, the beds to which the name“Greensand” had originally been applied by Smith and Webster2 are now called “Upper” Greensand, a term that has given rise to much confusion3; and, secondly, the “Ferruginous Sands” are now known as “Lower” Greensand, a name that was strongly condemned by workers like Fitton, Godwin-Austen, and Judd. It is on record4 that even Jukes-Browne admitted that he had long been endeavouring to do away with the awkward and misleading terms “Upper” and “Lower” Greensand ; but these names, though better not used without locality, have now become too familiar and are too useful for mapping to be abandoned entirely in favour of the more precise stage names Cenomanian, Albian, and Aptian.

As I have paid some attention to the Eskers of Ireland, perhaps I may be allowed to make a few notes on the papers of Mr. F. J. Jamieson recently read before the Geological Society of London, and the letter of M. Jespersen that appeared in the Geol. Mag. for December, 1874. These observers put forward the theory (if I understand them rightly) that these peouliar ridges of shingle, gravel, and sand may be in part glacial, they having been accumulated as marginal fringes to the different stages of the ice-cap that at one time covered the northern portion of the Continent of Europe, as it intermittingly retreated. This suggestion seems worthy of consideration, as possibly, if the ice-cap had an intermittent retrogression, there would be fringes or ridges of shingle, gravel, and sand marking each rest, formed of the detritus from each successive portion of the ice that disappeared; but such accumulations should be at different altitudes, and being carried by water off the ice, and deposited successively at its edge, should be stratified outwards,—or if the margin was retreating, they would be jumbled together.

The Upper Gondwána (Rajmahál Series) beds near Madras are divided into two groups, the lower of which has been named from Sripermatúr, a town 25 miles west-south-west of Madras, and a well-known locality for fossil plants. The group is composed of white and pale buff-coloured shales containing plants, at least 10 feet in thickness, resting upon sandstones, grits, and micaceous sandy shales, at least 15 feet in thickness, whose base is not seen, but which probably rest on the gneiss. Silicified wood occurs in some of the gritty beds. The other fossils occur in the shales, and consist of plant and animal remains. The latter are poor, and comprise two or three indeterminable species of ammonites and several lamellibranch bivalves.

There are two specimens of Bellerophon in the collection which may be co-specific—one is fairly well preserved, though a little distorted, and the other is worn.

A fenestrate bryozoan species recently collected from the Visean of County Fermanagh, Ireland, appears to correspond in all respects with Retepora nodulosa Phillips, from a similar horizon in Yorkshire. The last-named form was never satisfactorily defined or illustrated, the original type material is lost, and after being neglected for many years the name was declared a nomen dumium by Miller (1961). It is now recognized that, because of the presence of biserial carinal nodes, the species properly belongs in the genus Minilya, Crockford, 1944. It is here redescribed on the basis of a neotype from Fermanagh.

An account is given of the karst features of a given area, and ways of finding some order in their apparently chaotic arrangement. The simplest characteristic to study is the alignments of the karst features. These can be determined either subjectively (following the simple overall impression given by the area), or objectively (on the basis of various mathematical or graphical operations).

A distinction between “local” and “general” alignment by an elementary statistical-graphical method is proposed. This method is applied to the Lake Constance area, and the results are interpretated in relation to the geological features of the area. It is concluded that (a) the structural features of an area have a strong influence on the karst phenomena, and (b) there is a possibility of revealing, and even making geometrical determinations of, some geologically fundamental directions, e.g. tectonic—from an analysis of the distribution of such relatively superficial phenomena as karst features.

The distribution of alpha radioactivity in thin sections of Shap granite is discussed and more than 95 per cent of the activity is shown to be concentrated in the accessory minerals. The results of this study are compared with those obtained for the Adamello granodiorite by other workers using similar techniques.

Corallum conical and, as a rule, gently curved, though often straight; a short broad outline is not uncommon. The epitheca has well-marked longitudinal ribbing, sometimes obscured by fine annular striations in the neighbourhood of the calyx; slight constrictions of growth may occur, but there is never an interrution in the continuity of the epitheca. Good figures are given both by Milne-Edwards & Haime and by de Koninck.

Calcareous algae in limestones of the Permian Chihsia Formation near Nanjing, China, are preferentially replaced by quartz. Replacement postdates both cementation by sparry calcite and also neomorphic alteration of the original skeletons to sparry calcite. It is thus diagenetically relatively late. The original replacement silica could have been massive opal CT, opal CT lepispheres, or quartz. Lepisphere-like bodies occur in a few specimens. Megaquartz rims represent later overgrowths on the silicified skeletons. Although the original ultrastructure of the algal skeletons is not preserved, the preferential silicification allows fine details of the skeletal morphology of the algae to be observed and the distribution of silica indicates the style of replacement which has probably occurred. In some specimens it is possible that dissolution of the skeleton was followed by void-filling by silica, including the possibility of lepisphere formation. But in other cases in situ replacement, probably by massive opal CT or quartz, is reflected by the replacement of the outer parts of calcite crystals by silica. This process produces a network of silica, and as it proceeds the calcite centres of the grains become progressively smaller until silica replacement is complete. Sponge spicules may have provided the most important silica source for replacement. It is proposed that water-insoluble organic films surrounding matrix grains, and now preserved as bituminous material, protected the matrix from replacement thus promoting selective late diagenetic silicification of these fossils.