TOBAGO, a picturesque island 26 miles long and 7½ miles wide, lies 20 miles north-east of Trinidad and rises to a height of about 1,900 feet. Geographically it is an indirect lateral offshoot of the Northern Range of Trinidad but geologically its structure has distinct and individual characters. The sequence of formations has been describedby Mr. E. H. Cunningham Craig and my sketch map is adapted from his map with a few additions, such as the Arca patricia bed at Red Point and the outlier of coral rock at Plymouth. I spent about a week on the island and devoted most of the time to work on the later formations.

SOME recent studies on the periodicity of earthquakes have thrown light on their origin and especially on that of their attendant after-shocks. The periods that are of most service for this purpose are the solar periods of one year and one day, the lunar periods of 29·6 and 14·8 days, and the period of 42 minutes due to the throbbing of the earth in consequence of the crustal displacement that gives rise to the earthquake. As a rule, the maximum epoch of the annual period falls either in midwinter or in midsummer, that of the diurnal period about midnight or noon, that of the period of 29·6 days close to the times of either new and full moon, that of the period of 14·8 days at or about the times of new and full moon or of first and last quarter, and that of the 42 minute period either with the return movements after their passage to the antipodes and back or half-way between these returns.

THE plateau-lavas of Antrim cover an area of approximately 1,550 square miles—the largest area of Tertiary lavas in the British Isles. Although from the earliest daysof geological science these lavas have attracted many observers, very little has been done in the way of petrological study and, curiously enough, the dominant olivine-basalt lava has never been analysed.

IN the course of the Leicester meeting of the British Association in 1933, Section C visited the Nuneaton district and saw, amongst other exposures, sections showing the junction of the Cambrian and Pre-Cambrian. Two of these have never been previously described, and the most striking one (that in the north corner of Messrs. Boon’s quarry) was only first seen by the writers when on a preliminary tour of the excursion route. Both sections merit description, in view of the light which they throw upon the nature of the unconformable junction of the two systems, and upon the character of the Pre-Cambrian rocks and their relation to the rocks of Charnwood Forest.