The drainage pattern of North-West Scotland is considered in relation to already known and newly inferred fracture zones, and it is concluded that a system of Tertiary fractures, connected with the plutonic centres of the Western Isles, has been superimposed on the rhombic pattern of late-Caledonian faulting.

Alternating zones of normal and reverse natural permanent magnetization, each comprising about twenty-five flows, have been found in the Tertiary and Quaternary plateau basalt series of Iceland. The techniques for measuring this permanent magnetization are discussed and some results shown. It is suggested that zones of normal and reverse magnetization may be useful for correlation purposes in volcanic districts. Some other possible applications of rock magnetism are mentioned.

Four new solitary tetracoral genera and their type species from the Mississippian of Western Canada are described, named, and discussed. These new genera are part of several previously undescribed coral faunas from the northern Canadian Rocky Mountains.

The heat generated by the radioactive elements in the surface of the earth has been calculated by Evans and Goodman (1941) and by H. Jeffreys (1952). The amount of radioactivity in the depths of the continents obviously cannot be directly calculated. In the following paper two physical reasons are given for believing that the amount of radioactivity in the depths exceeds that found in the surface.

It is demonstrated that a deficient mass reaching within 10 km. of the surface is responsible for the central belt of negative gravity anomalies in the Eastern Alps. Hypotheses for explanation of the deficient mass are discussed and it is concluded that the presence of unexposed granite in addition to crustal downwarp is the most satisfactory of these. The position of part of the mass deficiency is irreconcilable with existing isostatic hypotheses and an alternative hypothesis is proposed. The development of the granite mass deficiency is briefly discussed.

Some variations in the apertures of Cribrohantkenina are arranged in morphological series. The development of the “cribrate” aperture and its relation to other biocharacters, such as the shape of the chambers, development of spines, and globosity of the chambers, is discussed, as also the status of the subgenera of the genus Hantkenina.

The paper describes a horizon of greywackes outcropping on the coast near Macduff, Banffshire, and containing large boulders of igneous and metamorphic rocks. This horizon belongs to the Macduff Group of the Upper or Banff Division of the Dalradian. It is suggested that the boulders may have been dropped into the greywackes from floating ice.

Within the main serpentine of Unst, a lower peridotite layer, a dunite layer, and an upper pyroxenite layer can be distinguished. These three zones have transitional contacts which are marked by a primary mineral banding. Analyses of specimens from each zone are given and it is suggested that the layering is due to differentiation in situ. The zones dip steeply eastward and the base of the intrusion is cut off on the west by a thrust which is slightly oblique to the banding and locally cuts out the peridotite zone. Interior planes of dislocation are parallel to, or perpendicular to, the primary banding.