An interesting discovery having just been made in consequence of the examination of a single thin slice of rock, the following communication is recommended to the attention of those geologists who, to say the least, still fail to recognize the value of the microscope in geological investigations.

Through the kindness of the late Rev. W. B. Clarke, of Sydney, I had the opportunity of examining two collections of fossil plants from Australia, which that gentleman had kindly placed at my disposal, together with explanatory notes, which he communicated to me in private letters.

This cast indicates a subfusiform shell with a somewhat elongated conical spire, but the apex is imperfect: volutions contiguous and convex; the body-whorl gradually tapering to a somewhat acute base.

The “Pennine Chain” is the name (restored about fifty years ago by Conybeare and Phillips from the “Alpes Penini” of the Romans) for that hilly tract of country that stretches from the borders of Scotland on the North to the centre of Derbyshire on the South. This important range possesses the structure of a great, though complex, anticlinal, the result of a meridional movement of upheaval that took place at a remote period in the physical history of our island.This axis of elevation, which ranges a little west of Narth through North Derbyshire and Yorkshire, throws off the Coal-measures of Yorkshire and Derbyshire on the one side, and those of Lancashire and North Staffordshire on the other, with a steeper did on the West, and a gentler inclination on the East. The maximum of this upheaval is attained in North Derbyshire, where a dome-shaped mass of Mountain Limestone has been exposed at the surface at an altitude of 1500 feet above the sea.

In Quart. Journ. Geol. Soc. 1877, pp. 906, et seq., Prof. Bonney describes a Gabbro from Coverack, on the eastern coast of the Lizard peninsula, which he remarks bears, macroscopically and micropically a close resmblance to the Forellenstein of Volpersdorf. I order to investigate further the nature the rock, I made, at his suggestion, an analysis of it. The piece selected had proved on microscopic examination to be almost free from pyroxenic constituents. No. I. was decomposed by fusion with alkalies. No. II. by hydrochloric acid. The residue in this case was white, and probably consisted of undecomposed felspar, showing that at any rate it was not all anorthite. No. III. is an analysis of the Volpersdorf rock quoted by Zirkel (Lehrb. der Petrog. ii. 139).

During the last summer I made a journey from Yedo as far north as the southern end of Kamschatka. As when upon this trip I saw and visited many volcanos in Yezo and the Kuriles, I venture to offer a few remarks in addition to those which I have already expressed upon the form of this interesting class of mountains.