Before proceeding further with these notes on the geology of The Lizard it will make matters clearer if the sequence of rocks is given as established by the Cornish and other geologists, but I have ventured to introduce modifications which will be explained later:—

Youngest: Kennack granite.

Kennack gneisses, consisting of doleritic and granitic components.

The Outer Hebrides, lying off the north-west coast of Scotland, are of particular interest to the student of Pleistocene geology, on account of the grand scale on which the results of ice-action are to be seen, and because of the marine shell-beds which are to be found at the northern end of the Isle of Lewis. In the present paper no general survey ofthe glacial deposits of the Outer Hebrides will be attempted; my object is rather to drawattention to certain features of the marine fossils, as a study of the coast sections shows that a faunal sequence can be established in the Pleistocene series.

There are three principal types, peat, fen clay (otherwise called blue buttery clay), and silt, in the post-glacial deposits of the Fenlands, which lie mainly within the shires of Cambridge and Lincoln, and Norfolk. It has long been known that Foraminifera occur in the silt and clay. The genus Lagena was recorded from the silt by Williamson in 1848, with twelve species from March, and sixteen species from Boston. In 1865, Parker and Jones listed thirty-five species of various genera from four samples of sub-Recent clay and silty clay from near Peterborough, Boston, and Wisbech. In 1870, H. B. Brady described the living brackish water Foraminifera from our coasts, and compared them with those recorded from the sub-Recent Fenland deposits by Parker and Jones. In a footnote (p. 306) he added the record of eight more species, so he presumably had a private communication from these authors, or himself studied further material. In 1881, James Green in two short papers noted the occurrence of abundant Foraminifera in layers of the March roddon, and figured nine species therefrom.

Although two years have passed since the British Association Committee on Rock Nomenclature and Classification reported in favour of using grain-size as an important factor inclassification, very few petrologists have accepted the Committee's invitation to discussand criticize the suggested scheme. This silence may be taken to mean consent; but in some quarters the older scheme, based on mode of occurrence of the rocks, still finds favour. It is instructive to inquire how far it is correct to speak of the scheme as new. Actually one does not have to dig deeply into petrological literature to realize that the principle of grain-size classification has been advocated for many years; indeed, it was the guidmg principle in some of the earliest scientific attempts at rock classification, notably in the well-known scheme elaborated in his Lehrbuch der Petrographie by Ferdinand Zirkel in 1866 and 1893–4. The reactionagainst the complete subordination of mode of occurrence found expression in the second edition of Rosenbusch's Mikro-skopische Physiographie (1887), in which the igneous rocks were divided into (1) deep-seated rocks, (2) dyke rocks, and (3) effusive rocks, each of these main categories being subdivided in terms of mineral content. In quite recent times A. Johannsen (1931)

An interesting paper has appeared in the Bulletin of the Eoyal Academy of Belgium, summarizing the general stratigraphy of the pre-Bukoban (i.e. pre-Devonian of Europe and pre-Katanga of Central Africa) rocks of Central Africa. It also includes a profile of the Basement Complex of Tanganyika. This note refers to the above-mentioned section of the paper only.

The area included in this survey comprises that part of the Clyde Plateau Lavas and associated sediments which lie within the Geological Survey 1 in. Sheet, number 39. This northern portion of the Campsie Fells was previously mapped for the Geological Survey by Peach and Jack, but the lavas were not separated into their petrographic types. It is this latter task that constitutes the main part of the work of this paper.