During the construction by the Hastings Corporation of a new arterial road to th.e north of St. Leonards, near Silver Hill, not far from the Old Eoar Waterfall, and close to the quarry dubbed by Mantell the “Iguanodon Necropolis”, the cutting passed through some sandy beds of the Wadhurst Clay Series. In these there was one particular stratum that had been a pale blue concretionary calciferous sandstone, but which had been altered for the most part by the percolation of water into a rusty-brown ferruginous sandrock.1 Numerous large, typical concretions occurred in it, but besides these Mr. H. L. Tucker, who was then acting as engineer to the contractors for the work, noticed the presence of certain huge spiral bodies that seemed to differ from the ordinary concretions. These bodies generally lay in cavities, or “moulds” in the surrounding sandstone, but unfortunately no part of these moulds was preserved.

The “bluestone” which is found in the central parts of some of the concretions associated with the large spiral bodies described by Mr. B. B. Woodward is found, on microscopical examination, to be a calcareous sandstone. Sabangular grains of quartz, averaging 0·04 mm. in diameter, constitute over 50 per cent of the rock, and are set in a cement of carbonates which have crystallized in plates very much as in the Fontainebleau sandstone. These plates are sometimes 3 cm. across, and give a characteristic lustre to the stone. The quartz-grains are evenly distributed through the plates of crystalline carbonate, and are so closely packed as to be almost in contact. It is easy to imagine that with the complete removal of the carbonates by solution there would remain a friable sandstone, very porous, but still occupying almost the same volume as the bluestone.

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.

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.

In spite of Freeh's detailed work on the Devonian Aviculidæ, the application of the specific name costata to certain members of the genus Pterinea is even now a matter of some dispute, and Drevermann considers that Freeh included under this name some shells which properly belong to Pt. Pailletei De Vern. Walther and Fuchs have more recently described the internal characters. Williams has chosen the species as the type of his new subgenus Cornellites.