The two substances known as “Tasmanite” and Australian “White Coal,” which are the subject of the present communication, have a special interest for the geologist on account of the light which they throw upon the microscopio structure and composition of many Coals. My attention was first directed to them when collecting materials for Professor Huxley’s examination into the microscopic structure of Coal. My esteemed colleague, Mr. Etheridge, at that time gave me a specimen of brown laminated substance, labelled “Lignite, the so-called White Coal, Australia,” and drew my attention to the fact that it was very largely composed of small seed-like bodies, very similar to, although smaller than, the macrospores of Flemingites, which are to be seen in many kinds of British Coal. A specimen of this same kind of White Coal is in the Museum of Practical Geology, and is labelled, “ Bituminous Shale (locally called White Coal), New South Wales, Australia.” I have likewise been able to examine the specimen of Tasmanite also in this Museum, which is labelled “ Tasmanite; combustible matter from the river Mersey on the north side of Tasmania; stratum of unknown thickness, but known to extend for some miles. Presented by Sir Won. Denison.” These specimens are very similar in appearance and structure, but the White Coal is softer than the Tasmanite. Chemical analyses of Tasmanite have been published, but I am not aware of any satisfactory account of ’its microscopic structure. The only mention of Australian White Coal with which I am acquainted is that in Prof. Huxley’s lecture on “On the Formation of Coal” (“Contemporary Keview,” Nov. 1870). And there is a figure, of a section and some separated spores, given by Sir C Lyell in the 2nd edition of his Student’s Elements of Geology, 1874.

Amongst the parallelisms which may be drawn between the Silurian series of Britain and that of North America, none so far has been so certainly established as the equivalency of the “Niagara Formation” to the Wenlock Group. In its most typical development, as in the State of New York, the Niagara formation, consists of an inferior series of argillaceous sediments, the “Niagara Shales,” and of a superior series of calcareous accumulations, the “Niagara Limestone.” At the Falls of Niagara itself, and at the Falls of the Genesee at Rochester, the shales and limestones are about eighty feet in thickness each. In Pennsylvania, the Niagara formation is wholly shaly, and has a thickness of over fifteen hundred feet. In the States west of New York, again, the formation is almost wholly calcareous, many of its members being true dolomites, and its total thickness rarely reaches three hundred feet, and is usually much less. In Western Canada, finally, the Niagara shales can rarely be detected as a distinct group, and the formation consists mainly of limestones, often magnesian, with subordinate courses of shale, the whole usually varying from one hundred to two hundred feet in thickness.

In no part of Europe, probably, can we find such striking examples of the effects which may be produced by single paroxysmal outbursts of volcanic force, as in the band of igneous rocks which stretches through nearly the whole length of the Italian peninsula, on the western side of, and parallel to the chain of the Apennines. Etna and many of the extinct volcanos of this continent constitute, it is true, mountains of vaster bulk than any in the district to which we have referred; but while the former were evidently built up by the accumulation of the products of igneous forces operating during long periods from the same centres, and with comparatively moderate violence, the enormous craters of the latter bear witness to the occurrence of single outbursts of these forces of far greater intensity.

Any one who compares the terraces that are shaped by rivers and the sea with the terraces that are found in the Yorkshire Dales must see that in the one case the denuding agent has acted alike upon beds of all degrees of hardness, and has shorn off the edges of the rocks to one level, whether the strata were horizontal or inclined; in the other case the denuding agent has acted unequally upon the rocks according to their varying powers of resistance, so that the harder beds were left in relief; and, so far from being all shorn off to one level, it would perhaps be difficult to find any one of the Dale District terraces that is not more or less inclined. The bases of the cliffs formed by the one denuding agent are quite level: those left by the other are often inclined many degrees.

A correspondent communicated to Nature a reference to a description of this celebrated fall of meteorites, which is to be found in Gruithuisen's Naturgeschichte des gestirnten Himmels 407. As it does not appear to have been known to Buchner, it may be placed on record here.

In a traverse through part of Buckinghamshire and Bedfordshire last vacation, with the object of tracing the extent of the Cambridge Greensand, I was informed of some recently opened Coprolite works at Brickhill, near Bletchley. On further inquiry, they proved to be the “red coprolites,” a term applied by the workmen to the phosphatic nodules of the Neocomian like those of Potton and Upware (the Cambridge Greensand and Gault nodules being known as the “black coprolites”).