The Divisions of the Limestone—The Thrusting in South-East Northumberland and North-East Durham—The Breccias.

The largest, best exposed, and most interesting volcanic vent along the northern shores of Fife is that which has been laid bare at the headland of Kinkell Ness, and a portion of whose enclosed material has been sculptured into the picturesque shore stack known as the Rock and Spindle. (“These two words,” as Sir A. Geikie points out, “are generally misunderstood. ‘Rock’ is the Scots word for a distaff; and ‘Spindle’, as here used, has reference to the stellate mass of basalt resembling a spinning wheel.”) Reason for this appropriate designation will be readily gathered from the accompanying photograph (Plate XIII).

The Beer Stone is a gritty limestone, made up largely of shell fragments with some foraminifera, quartz grains, and 6oft chalky material, occurring in the Rhynchonella Cuvieri zone of the Middle Chalk near Beer Head in the south-east of Devon. It has long been worked for building purposes in underground galleries about one mile west of the village of Beer, and has been described by W. Hill and W. F. Hume in the Geological Survey memoir on the Lower and Middle Chalk. Dr. Hume records the following minerals as present in the insoluble residue of the stone: quartz, muscovite, glauconite, chalcedony, pyrites, tourmaline, rutile, andalusite, and possibly anatase. A. J. Jukes-Browne says the residue “contains a variety of minerals which have clearly been derived from land consisting of granite and Palaeozoic rocks such as occur in South Devon and Cornwall”.

During a recent examination of the Carboniferous Limestone in the Dove Dale district I have met with an abundance of Productus humerosus. This species is a common fossil in the cliffs extending for a distance of quite 2 miles from the top end of Nabs Dale to beyond Tissington Spires. It is most prolific at and near Reynard's Cave, where the shells occur in clusters, often cupped into each other.

One of the most striking features of our science is the need in which it stands of a large and widely distributed body of workers, and the opportunities which it affords to every one of them of making important contributions to scientific knowledge.