The question which heads this article is not a new one. An old one, indeed, it is; and, common as chalk flints and chalk ventriculites are, it does not show much energy on the part of cretaceous—we do not know how else to single them out—geologists and palæontologists, that this old question has never yet been answered.

The only man who has ever worked properly on the subject is Mr. Toulmin Smith, who many years ago laboured hard and well on these curious organisms, and then retired on his laurels. But Mr. Smith, like all men who have devoted themselves to a special subject, is full of prejudices—we do not mean to say errors—and no progress in our knowledge can be hoped to be made until these prejudices are attacked. Mr. Smith, having built his castle, is not likely to strengthen it until its walls have been undermined, or at least have been battered by the artillery of able antagonists. Dr. Bowerbank is considered to be the only powerful opponent of Mr. Smith's views; but whether the Doctor has expressed his opinions in print or only verbally in ordinary conversation, we do not know; at any rate, the world believes the amiable philosopher of Barnsbury Grove to differ in opinion from the ventriculite-anatomist of Highgate Hill. Mr. Smith believes them to be highly-organized polypidoms, which in their living state were covered over with tentaculated polypes, or that at least were studded with hundreds of tentacle-surrounded heads, ever waving their tiny arms, and catching and feeding upon the tiny prey or on fragments of animal substances which came within their clutch. What Dr. Bowerbank believes them to be we need not say is — sponges.

Since the publication of my paper “On the Discovery of Human and Animal Bones in Heathery Burn Cave, near Stanhope,” in the ‘Geologist’ for January last, there have been further very important discoveries made in that cave.

In carrying on the quarrying operations from the point where they were suspended (see F—fig. 1) when the first discovered relics were sent to London the workmen found numerous fragments of bones, also bone pins and knives, fragments of very rude pottery, portion of an armlet, boar-tusks, bronze spear-head, pins, celts, and armlet, two coins, some marine shells, cockle, limpet, and mussels, and large quantities of charcoal, etc., all deposited under an incrustation of stalagmite, varying from 2 to 4, or at some places to 8 inches in thickness, with the exception of one or two manufactured articles, which were found in the sand not covered by stalagmite. The whole of the cave-deposits, with this trifling exception, were covered by a thick sheet of stalagmite, varying from a very dense, compact structure, to a highly crystalline, or to a more or less porous substance: some portions easily fractured by the stroke of a hammer, others yielding only to most energetic blows.

The bronze armlet and the two coins were found in sand uncovered by stalagmite, but as they were deposited in what had, not long ago, been the watercourse, the stalagmite had either been denuded, or had been prevented from forming, at that particular place, by the action of the stream; the coins were under very little cover, and might have been imbedded very recently.

While almost every week increases our knowledge of the geology of distant parts of the earth, there is one small island in the British seas, famed for its picturesque beauty, and peculiarly interesting on account of its historical associations, of the geological features of which very little is known, and even that little scarcely ever referred to in geological treatises. This may have arisen mainly from the fact of there having been as yet no official survey of this island; while those portions of the geological series represented in the Manx rocks having been typically established from other localities, it did not seem to present geological features sufficiently novel or peculiar to require any special investigation. Still, in the earlier years of the science, several eminent geologists did describe, with greater or less minuteness, some of its geological appearances: for example, Professor E. Forbes, who wrote a short account of Manx geology for one of the local guide-books; and a much more elaborate account was written by the Rev. J. G. Cumming, F.G.S., and published in 1848; but the rapid progress of the science, while it does not deprive these descriptions of all value, has in a great measure superseded them, and opened here a wide and almost untrodden field for the modern geologist. Having for several years resided on the island, and being convinced that many of the phenomena presented by the Manx rocks, if not altogether new to the geologist, are yet of remarkable interest, and capable of taking a great part in the solution of many of the problems which geologists are now endeavouring to solve, I have written the following brief account, with the view of diffusing, through the pages of the ‘Geologist,’ a more general knowledge of the geology of the Isle of Man, and in the hope of attracting to the subject that attention which it deserves.