The region which forms the subject of this paper is in the southern part of the Republic of Ecuador (Fig. 1) in the Provinces known as Canar and Azuay, and is situated between the two principal cordilleras of the Andes at an elevation of about 8,500 feet above sea-level.

For many years English palæontologists were content with the limited number of Portlandian Gasteropoda described by Sowerby—principally from internal casts—in Fitton's celebrated paper on the “Strata below the Chalk.” Other authors have described a stray species here and there: still the list was scanty, and not only scanty but indefinite; and many ingenious guesses have been hazarded as to the true affinities of such species as Buccinurn angulatum, and Buccinum naticoides.

A new genus and species of the Lepidocentridae is described from the Lower Carboniferous at Hook Head, Ireland.

In the Geological Magazine for 1884 some Mesozoic fossils, obtained from near Mount Hamilton and the Peak Station, were noticed by me with figures and descriptions where the specimens were fairly well preserved. Since then additional specimens have been procured from adjoining districts. The general character of the facies is fairly similar to that already noticed in 1884; but on the whole, perhaps, the specimens are scarcely so well preserved. Since then additional specimens have been procured from adjoining districts. The general character of the facies is fairly similar to that already noticed in 1884; but on the whole, perhaps, the specimens are scarcely so well preserved. According to the opinion of those who have had most experience, these fossils may be regarded as of “Cretaceo-Jurassic” age, though I am not aware tliat such undoubted Cretaceous forms as Ancyloceras, etc., have been discovered in the beds whence the fossils forming the subject of these notes have been derived.

An attempt is made to correlate the concept of the fossil lineage with our knowledge of polytypic species. The influence of changing environmental conditions in the geological succession and the relationship between geographical and chronological sub-species is analysed on a theoretical basis. The fossil lineage is considered to be the resultant of combined evolutionary and environmental change. Phenotypic modifications in response to environmental conditions are discussed in relation to the study of variation in fossil communities.

Alecto dichotomoides was the name given by d'Orbigny in 1849 to a specimen figured by Michelin in 1841 from the Bajocian of Bayeux, or of Moutiers, Calvados, Normandy, and identified by Michelin as A. dichotoma, Lamouroux.

The Hirnantian stratigraphy of Wales is critically assessed against the global evidence for two major Hirnantian synglacial eustatic lowstands. The evidence for two separate lowstands of relative sea level is locally suggestive in shelf sequences but generally only permissive in the basin. Nowhere can the possible candidate lowstands be separated biostratigraphically and thus basinwide correlation that might rule out local tectonic control is impossible to prove. Consistent with palaeolatitude evidence and a situation far removed from the Gondwana margin, there is no facies evidence (e.g. dropstones) for local glacial conditions and the diamictites are of mass-flow origin. Sequence stratigraphic reasoning proves helpful in the correlation of the basinal succession in Central Wales with the shelf sequences along the Tywi Lineament and the Variscan Front, and suggests that the first appearance of Normalograptus persculptus in Wales does not correspond with the base of the persculptus Biozone. Extensive new palaeocurrent data and sedimentological restudy is combined with review of earlier knowledge to argue for significant revisions to previous palaeogeographic maps for ‘generalized lowstand conditions’, notably along the Bala Lineament, the Variscan Front and the Central Wales Inliers.

Spectacular celestine geodes occur in a Jurassic peri-evaporitic sequence (Ardon Formation) exposed in Makhtesh Ramon, southern Israel. The geodes are found only in one specific location: adjacent to an intrusive contact with a Lower Cretaceous basaltic dyke. Celestine, well known in sedimentary associations worldwide and considered as a low temperature mineral, may therefore be associated with magmatic-induced hydrothermal activity. Abundant fluid inclusions in celestine provide valuable information on its origin: gas-rich inclusions in celestine interiors homogenized at T≥200°C whereas smaller liquid-rich inclusions record the growth of celestine rims at T≤200°C. Near 0°C melting temperatures of some fluid inclusions and the occurrence of hydrous Ca-sulphate solid crystals in other inclusions indicate that celestine precipitated from variably concentrated Ca-sulphate aqueous solutions of meteoric origin. Celestine crystallized from meteoric water heated by the cooling basaltic dyke at shallow levels (c. 160 m) during a Lower Cretaceous thermal perturbation recorded by regional uplift and magmatism. The 87Sr/86Sr ratio of geode celestine, 0.7074, is similar to that measured in the dolostones of the host Jurassic sequence, but differs markedly from the non-radiogenic ratio of the dyke. Strontium in celestine was derived from dolostones preserving the 87Sr/86Sr of Lower Jurassic seawater, while sulphur (δ34S = 19.9‰) was provided by in situ dissolution of precursor marine gypsum (δ34S = 16.8‰) indicated by relict anhydrite inclusions in celestine. Low-temperature meteoric fluid flow during the Campanian caused alteration of the dyke into secondary clays and alteration of geodal celestine into quartz, calcite and iron oxides.

Through the intervention of my friend Mr. William Whitaker, F.R.S., I, some time ago, received from Mr. G. W. Colenutt, F.G.S., of Hanway Lodge, Ryde, Isle of Wight, 26 small slabs of Osborne clay, on which are preserved, in a more or less good state (generally less), a series of prawns and small shrimp-like Crustaceans, collected by him from the Oligocene strata, Chapelcorner Copse, between King's Quay and Wootton Creek, just to the west of the Boat-house, on the shore below Binstead House; also on the shore below Ryde House, and immediately to the south-east of Sea View Pier; where (especially at Chapelcorner Copse) extremely interesting exposures of the Osborne Beds may be seen and studied, between the base of the cliff and low-water mark (see p. 99).

Delimiting the Aravalli mountain range in the east, the Great Boundary Fault (GBF) occurs as a crustal-scale tectonic lineament in the NW Indian Shield. The structural and tectonic characteristics of the GBF are, as yet, not well-understood. We attempt to fill this gap by using a combination of satellite image processing, high-resolution outcrop mapping and structural analysis around Chittaurgarh. The study area exposes the core and damage zone of the GBF. Three successive phases of folding, F1, F2 and F3, are associated with deformation in the GBF. The large-scale structural characteristics of the GBF core are: (i) a non-coaxial refolding of F1 folds by F2 folds; and (ii) the parallelism between the GBF and F2 axial traces. In addition, numerous metre-scale ductile shear zones cut through the rocks in the GBF core. The damage zone is characterized by the large-scale F1 folds and the mesoscopic-scale strike-slip faults, thrusts and brittle-ductile shear zones. Several lines of evidence, such as the inconsistent overprinting relationship between the strike-slip faults and thrusts, the occurrence of en échelon folds and the palaeostress directions suggest that the GBF is a dextral transpression fault zone. Structural geometry and kinematic indicators imply a wrench- and contraction-dominated deformation in the core and damage zone, respectively. We infer that the GBF is a strain-partitioned dextral transpression zone.

The publication by the Geological Society of America of that momentous work by the late A. C. Veatch and P. A. Smith (1939) with its beautifully executed charts, following closely Douglas Johnson's stimulating contribution on the subject (1938), again focuses attention on those stupendous erosion-features—the “Submarine Canyons”. Through stressing the relatively brief space of time available for their evolution, this latest pronouncement only renders more of an enigma those gigantic furrows that would now seem to fringe so much of the continental margins. As Daly has remarked (1936, p. 402), they appear to be planetary and not merely regional. It is in the Atlantic, however, that they have been most thoroughly studied.

The general results which have accrued from this investigation may be summarized as follows: the shaly type of Liassic sedimentation with much pyrite, indicating a quiet sea with abundant sulphur compounds, gradually gave place to a regular and at first fairly steady shallowing of the water with, somewhat later, occasional incursions of strong currents bringing pebbles and broken fossils from an area undergoing active erosion. At the same time the amount of iron introduced, both in solution and in the form of derived ooliths, increased steadily, culminating in the siliceous oolite of the Dogger, which is essentially similar to the rocks composing this formation to the west and north-west.

The remarkable frontal spine of Squaloraja has always been described as a dermal structure by those who have referred to it, and has been classed with the shagreen-granules and dentition. After the systematic position of the genus had been determined, its frontal spine was rightly recognized as identical with the spine-like frontal process in Chimæra and fossil Holocephala, with which it was formerly compared by W. Davies and A. S. Woodward. Both these processes were regarded as dermal structures by von Zittel, Jaekel, and A. S. Woodward, and treated as true ichthyodorulites, i.e. as if consisting of dentine or vasodentine. In 1890 the present writer briefly pointed out that the frontal spine of the Jurassic Chimæroid, Ischyodus avita, consisted of extremely calcified fibro-cartilage, resembling that of the so-called “claspers” of all male Elasmobranchs. The microscopical structure of these parts differs conspicuously from that of the calcified granules in the common (hyaline) cartilage of the internal skeleton, and its ontogenetic development is different.

In a previous article, a sketch has been given of what is known concerning the origin and history of the early manuscript maps of William Smith. I have shown that concerning these maps, though they were not published, in the technical sense of that term, there exists a satisfactory body of external evidence with regard to the period of their preparation, while they furnish in themselves abundant proofs that they must have been constructed at the dates inscribed upon them. These facts have been so generally recognized that—since the clear statements on the question which have been made by Fitton, Parey, Sedgwick, and Phillips—no one has ever thought of either questioning the antiquity of the maps or denying to William Smith the honour of being the first to construct a true geological map of England and Wales.

It is suggested that the name beerbachite be reserved for fine- to medium-grained granular dyke rocks of gabbroic composition occurring in coarser-grained gabbro. It should not be used for basic granular hornfelses or xenoliths.