It has recently been suggested that many of the dry valleys which are found in limestone districts owe their formation to subterranean solution, and not to surface-erosion; in other words, that they are the work of subterranean watercourses which, by dissolving the rock substance, have caused subsidence of the surfaces overlying the lines of such watercourses.

A recent visit to Central Germany afforded the writer an opportunity of studying the conditions under which the Vogelsberg iron-ore and bauxite have been formed, and a brief account of what was observed may assist in broadening the basis upon which a sufficiently comprehensive view of the origin of those substances may ultimately stand. On this account my visit to the region was approved by the Department of Agriculture in Ireland, in connection with the work now in progress on the iron-ore and bauxites of co. Antrim. In my traverses I enjoyed the very agreeable companionship of Dr. Schottler, of the Grossherzoglich Hessischen Geologischen Landestaldt, and the advantage of his guidance. His elaborate description of the basalts in the vicinity of Giessen has since been issued, and is referred to in this paper. The admirable and exhaustive accounts of the bauxite by Professor Adolf Liebrich, and of the iron-ore by H. Münster, are also appealed to frequently. Among other important papers consulted regarding the chemical processes involved may be mentioned those of M. H. Coquand, Professor G. A. Cole, F.G.S., M.E.I.A., Max Bauer, Sir T. H. Holland, A.R.C.S., F.E.S., H. Warth, D.Sc., & F.J. Warth, B.Sc., Malcolm Maclaren, B.Sc, F.G.S., H. Brantwood Muff, B.A., and the summaries by F. Wigglesworth Clarke and Dr. C. Doelter.

The specimen herein to be considered is one of great historical interest, for it was the first specimen of an Edrioasteroid made known to science. It was discovered by Dr. J. J. Bigsby in limestone now recognised as of Lower Trenton age, forming Table Rock at the Chaudière Falls on the Ottawa River at Ottawa (then called Bytown). Canada, in 1822. Brought by Bigsby to England, it was figured and described, though not named, by G. B. Sowerby in 1825. E. Forbes, who had the speciman for study, referred to it in his memoir “On the Cystideæ of the Silurian Rocks of the British Islands,” since the “aspect” of his Agelacrinites Buchianus “immediately called [it] to mind”; he even went so far as to say that there could “be no question … of its being generically allied” to that species. Considering the not unnatural inadequacy of Sowerby's description and figure, the reputation that Forbes had as an authority on echinoderms, and the comparative imperfection of the first found specimens of Edrioaster, it was not surprising that E. Billings in 1856 should have supposed a new Trenton fossil, undoubtedly congeneric with Agelacrinites Buchianus, to be of the same species as that found by Bigsby and should therefore have applied to it the trivial name ‘Bigsbyi,’ while giving to a fossil of obviously different structure the name ‘Agelacrinites Dicksoni.’ In February, 1858, Billings travelled to London with the fossils in question, and found that Bigsby's specimen was not, after all, the same as his Cyclaster Bigsbyi, but was specifically identical with his A. Dicksoni. He redescribed the species, and had his type-specimen, as well as Bigsby's fossil, figured by C.R. Bone.

A Specimen of Cyclus has lately been acquired from the Carboniferous Limestone of St. Doulaghs, co. Dublin, which indicates a new species, though it is allied to several which have been described by Dr. Henry Woodward. The latter gave in 1894 a review of our knowledge of this curious little Crustacean genus, and his view that it is an Entomostracan and probably one of the Phyllopoda has been generally accepted, though more recently (1905) he has suggested that the members of this genus are but the larval stages of Coal-measure Limuloids.

It may be taken for granted that everybody agrees with Dr. Molengraaff when, in discussing Dr. Hatch's paper on “The Oldest Sedimentary Rocks of the Transvaal,” he says: “There must exist, or have existed, a formation older than the Witwatersrand Beds, because even at the very base of the Hospital Hill series conglomerates are known, the pebbles of which cannot obviously have been derived from the Hospital Hill series by denudation.” It has, therefore, I take it, not been the intention of various authors to prove this self-evident truth, but only to try and definitely settle the still open question whether this older rock is yet represented in the geological sequence of the country, and, if so, what strata should be identified as such. The relative age of the ‘old granite’ or ‘grey granite’ has been the base and the cornerstone of controversy on this subject, and it therefore becomes imperative to put on record and to continually keep in mind the only reliable mode of determination of the age of eruptive rocks which we yet possess. It would be out of place here to insist upon the origin of abyssal eruptive rocks of the granite family (Rosenbusch's Tiefengesteine).

The separation of the weakly magnetic minerals of crushed rocks, sands, etc., is best effected by using an electromagnet, which, if suitably constructed, is, for any given size, much stronger than a permanent magnet. The electromagnet exerts no attractive force when the current is shut off, and for this reason the process of separation is made easy, as the grains which have been attracted to the poles drop when the current is switched off.

Towards the end of January last the inhabitants of Lyme Regis were somewhat alarmed by the announcement that a portion of the cliffs on the eastern side of the town, towards Black Ven, was “on fire”; a “Full Report of the Volcanic Eruption” was soon afterwards published in the Bridport News for January 24. It was then stated that on Sunday, January 19, “dense vapour appeared at intervals to rise from a mound on the edge of the cliffs, about half-way between Lyme and Charmouth,” and that the burning portion “consisted of a large fallen mass of the cliff which had some time since slipped away from the body of the cliff.” Mr. A. C. G. Cameron, who was at the time resident at Lyme Regis, explained that the case was one of spontaneous combustion, due to the decomposition of iron pyrites and the consequent generation of heat sufficient to ignite the bituminous shales of the Lower Lias.

As bearing upon the phenomenon of the spontaneous combustion of bituminous beds of coaly or carbonaceous matter of any geological age (charged with pyrites) in sitû, the account given by Sir John Richardson, C.B., F.R.S., in his “Arctic Searching Expedition; a Journal of a Boat-voyage through Rupert's Land and the Arctic Sea,” 1851, vol. i, may not be without interest in this connection.

Since the appearance of my paper on Loricula Darwini in the November Number of this Magazine (pp. 491–9) my attention has been called by Mr. C. D. Sherborn to two American Loriculæ described by W. N. Logan, “On some new Cirriped Crustaceans from the Niobrara Cretaceous of Kansas,” U.S.A., published in the Kansas University Quarterly (series A, October, 1897, vol. vi, No. iv, pp. 187–9, 8vo) and in the University Geological Survey of Kansas (vol. iv (Paleontology), pt. viii, 4to, Arthropoda, pp. 498–501, pi. cxi) under the names of Stramentum haworthii, Williston, type-specimen figured much enlarged, and S. tabulatum, Logan. The other two species on p1. ex, figs. 3–5, of the same work, described under the name of Squama spissa and S. lata, Logan, are quite distinct from Loricula, but are said to have been found adhering to a fragment of shell of Inoceramus by their entire length. The arrangement of the capitulum and peduncle differ very widely from those of Loricula and resemble Pollicipes.