We are not ashamed to confess our ignorance when we meet with anything we do not understand. On the contrary, we regard such confessions as one of the roads to knowledge; and we always wished it to be one of the features of this magazine that matters not understood should be brought before the world in its pages. We set the example ourselves in the most prominent part of our journal—its opening pages.

Few things are so little understood as fossil vegetables, and least of all are fossil fruits.

Some new species from the lower chalk of Rochester have just been added to the national collection in the British Museum, and we lay our drawings of them before our readers with the frank admission that we do not know what they are, and we ask as frankly for information or suggestions.

Some indeed, such as the coffee-like berries, fig-like fruits, and nipadites of the London Clay, carry in themselves the palpable evidence of the classes to which they belong; but there are many specimens from other rocks remaining undescribed in many a collector's cabinet from the want of the ability to give anything like a reasonable suggestion as to what they were, and often, indeed, from the sheer incapacity to assign to them even any probable affinities.

In the year 1859, M. Marcou proposed to substitute the word “Dyas” for “Permian,” and summed up his views by saying that he regarded “the New Red Sandstone, comprising the Dyas and Trias, as a great geologic period, equal in time and space to the Palæozoic epoch or the Grey wacke (Silurian and Devonian), the Carboniferous (Mountain-limestone and Coal), the Mesozoic (Jurassic and Cretaceous), the Tertiary (Eocene, Miocene, and Pliocene), and the recent deposits (Quaternary and later)”!!

As that author, who had not been in Russia, criticized the labours and inductions of my associates De Verneuil and Von Keyserling, and myself, in having proposed the word “Permian” for tracts in which he surmised that we had commingled with our Permian deposits much red rock of the age of the Trias, I briefly defended the views I had further sustained by personal examination of the rocks of Permian age in various other countries of Europe.

It was, indeed, evident that M. Marcou's proposed union of the so-called Dyas and Trias in one natural group could not for a moment be maintained, since there is no conclusion on which geologists and palæontologists are more agreed, than that the series composed of Roth-liegende, Kupfer-Schiefer, Zechstein, etc., forms the uppermost Palæozoic group, and is entirely distinct in all its fossils, animal and vegetable, from the overlying Trias, which forms the true base of the Mesozoic or Secondary rocks.

The limestones, slates, and associated sandstones of North and South Devon and Cornwall have, as is well known, caused much perplexity as to their real place in the chronological series of the geologist. Thanks, however, to the labours of Professor Sedgwick, Sir R. I. Murchison, Mr. Lonsdale, and others, the problem is now generally admitted to be solved; the rocks in question are the representatives or equivalents of the Old Red Sandstone of Scotland and elsewhere; they belong to what is known as the Devonian age of the world. Some little difficulty, however, exists—or rather once existed—in the way of the full acceptance of this chronology. The rocks of Devonshire are crowded with the remains of invertebrate animals, especially shells, corals, and sponges; whilst the supposed contemporary deposits in Scotland and the adjacent islets are so rich in fossil fish that, in the language of the late Hugh Miller, “Orkney, were the trade once opened up, could supply with ichthyolites, by the ton and the shipload, the museums of the world.” But the fossils characteristic of either of these districts are not found in the other; there are no organic links connecting the two localities. Scotland does not yield the mollusks or zoophytes of Devonshire, nor is there recorded in the latter district more than the faintest trace of the ichthyolitic wealth of the North. Though this fact may still have difficulties connected with it, they have ceased to be chronological, for Sir R. I. Murchison tells us “that the same fossil fishes, of species well known in the middle and upper portions of the Old Red of Scotland, and which in large tracts of Russia lie alone in sandstone, are in many other places found intermixed, in the same bed, with those shells that characterize the group in its slaty and calcareous form in Devonshire, the Rhenish country, and the Boulonnais. This phenomenon, first brought to light in the work on Russia, by myself and colleagues, demonstrates more than any other the identity of deposits of this age, so different in lithological aspect, in Devonshire on the one hand, and central England and Scotland on the other. The fact of this intermixture completely puts an end to all dispute respecting the identification of the central and upper masses at least of the Old Red of Scotland with the calcareous deposits of Devonshire and the Eifel.”

While examining lately the magnificent collection of fossil musk-deer, from Auvergne, in the collection of the British Museum, in the case devoted to the specimens collected by M. Bravard from the lacustrine calcareous marls of Puy-de-Dôme, a singular anomaly in the structure of the crania of the genus Cainotherium met my view. All the writers who have described the osteology of the skull of Ruminants have noticed those singular deficiencies or lacunæ which exist at the points of junction of the various bones, and which have been variously described as “lacrymal openings” or “facial interspaces.” Their function has been unknown, and their presence, although constant in each individual species, is variable in species nearly allied to each other. In the Cainotherium commune, Bravard (Microtherium Renggeri), nearest allied to the Hyomoschus of the present day, ossification at this lacrymal point of intersection has extended to a much less degree than in its living analogue. The interspace in Cainotherium is longer in proportion to its breadth than the existing musk-deer (Moschus chrysogaster). In the Dorcatherium Naui, Kaup., on the contrary, not the slightest interspace is exhibited, and the lacrymal angle is definitively closed: In some of the specimens named Cainotherium in the British Museum, no interspace exists. These probably belong to a separate species, as De Blainville remarks on the typical Cainotherium commune, termed by him Anoplotherium laticurvatum, that it possesses “des lacunes sous-lacrymales assez grandes, en forme de longues virgules.”

In a tolerably deep ravine, surrounded by trees and brushwood growing in wild profusion, was, until lately, a cave, in that member of the carboniferous formation locally called the “Great Limestone,” and situated about one mile and a quarter north from the town of Stanhope, in the county of Durham. The limestone is now being worked for the purpose of supplying the Weardale Iron Company with a flux used in the operation of smelting their ironstone; and consequently the cave has been laid bare to the light of day.

The cave was much visited a few years ago, both by strangers and persons living in the locality, but probably few of the visitors ever studied the excavating forces by means of which the cave was hollowed out of the solid limestone, and fewer still, if any, would think that they were treading on a primeval burial-place.

Doubtless the excavation must be mainly due to aqueous agency, but a reference to Sir Charles Lyell's ‘Principles of Geology,’ Professor Phillips's ‘Treatise on Geology,’ and Richardson's ‘Geology,’ shows that our leading writers on this subject consider that the first cause of a cavern must have been a fracture in the limestone rock, consequent on the upheaval of the strata, and that water then finding access to the crack, would wear it out to its present dimensions.