In the September Number of the Geological Magazine, 1890, I offered some notes on certain Triassic Estheriœ of North America and Bavaria, and on an Estheria from the Purbeck strata of Wiltshire. An interesting example of E. membranacea from the Old Red of Orkney was figured, but not described. We have now the Rev. W. R. Andrews's other Purbeck Estheria, referred to at p. 389, ready for description; another Triassic Estheria from Pennsylvania; and some most interesting specimens of the rare Estheriella, instituted as a subgenus by the late Professor Dr. Ch. Ernst Weiss.

I Propose in this paper to write a short account of the earthquakes that have been felt in Great Britain during the year 1889, and to consider the relations of these earthquakes with the geological structure of the districts in which, they occurred. The attempt seems to me worth making, for two reasons. The first is that, though few in number and slight in intensity, the earthquakes which visit this country are individually and in their connexion with preceding shocks, of considerable interest. And, secondly, the accounts, even when published, are widely dispersed, and, appearing chiefly in local newspapers, become difficult of access in after years.

I am aware that in describing a new apparatus for separation by heavy liquids, I am adding another item to a list which is already a very long one. My only excuse is that this particular form has the advantage of being easily and cheaply constructed from ordinary chemical apparatus, and yet has most of the advantages of Thoulet's comparatively expensive form.

I have already shown that the northern boundary of the Indo-Gangetic alluvium is a structural one, and that the rock area immediately to the north of it has been elevated, while the nature of the boundary on the south, the deep imbayments of the alluvium, the gentle manner in which the older rocks slip under it, and the inliers, alike show that, on the south, the alluvium has gradually encroached on the rock area by the subsidence of the latter.