One of the most notable additions made to the Gallery of Fossil Reptilia in the Natural History Museum during the last few years is the beautifully preserved Plesiosaurian skeleton which is represented in Plate IX.

Amongst the numerous species of Trilobites which occur in the impure limestones of Bala age in Co. Waterford, two new and undescribed forms were recently found by me in the course of a preliminary examination of that area. At present the exact horizon of the beds has not been determined, but they may undoubtedly be referred to the Bala series. One of the new species belongs to the genus Cybele, and is a most bizarre form, with a long, snout-like projection of the anterior margin. The other is a new species of Trinucleus, bearing some resemblance to Angelin's T. bucculentus, which occurs in beds of “regio Ba” in Norway.

Since the remarkable paper by Professor Lapworth “On an Improved Classification of the Rhabdophora” was published in the Geological Magazine for 1873, a great deal of fresh information has been gathered as to these interesting fossils; but the classification given in that paper, though to some extent confessedly artificial, is still generally adhered to. Observations made by the authors in recent years lead them to suppose that that classification will in the future undergo considerable modification; but in the present state of our knowledge it serves a purpose so useful, that it is not our intention to propose any immediate change in it. Our object, on the other hand, is to bring forward certain conclusions which we have independently reached, and which will, we believe, enhance the value of Graptolites to the stratigraphical geologist, and lead to results important to the biologist. Our conclusions are based upon an examination of a large number of forms generally referred to the family Dichograptidæ; but, as we propose very briefly to indicate, they affect the relationships of Graptolites belonging to other families also.

The history of the Zambesian territories now known as “Rhodesia” is extremely meagre. Of the country prior to the advent of the Matabele in 1838, little is known, except from the few records, chiefly Portuguese, that have been preserved. It should be mentioned, however, that an interesting link between the Sofala and the Zimbabwi ruins near Victoria exists in certain gold tacks or rivets, possibly used in the manufacture of gold ornaments, which have been found in both these places, while we believe that at intervals along a route to the coast, ruins of towers have been found, that in all probability have been used as stations on the way.

Since the publication of the notes on some new fishes from the English Purbeck and Wealden Beds five years ago, the Rev. W. R. Andrews, of Teffont, has kindly entrusted to the writer for examination a fine series of Purbeckian fishes from the Vale of Wardour. All the members of this fauna are remarkably diminutive, compared with those met with in the corresponding formation in Dorsetshire; but nearly all the species are well preserved, and some are sufficiently novel to be worthy of detailed description. The Pycnodont genus Mesodon, which was first described from the English Purbeck in the paper already cited, is here represented by one or two more forms; the Lepidosteoid Macrosemius is now first definitely recorded as a British fossil; additional examples of Pleuropholis extend previous information of that genus; new specimens of Leptolepis Brodiei add to the known specific characters of this fish; and the opportunity is now afforded for publishing a figure of the small Palæoniscid, Coccolepis andrewsi.

By the kind assistance of Monsieur E. Dupont, the Director of the Royal Museum of Natural History in Brussels, a coloured reproduction of the entire skeleton of Iguanodon Bernissartensis has lately been acquired for the British Museum (Natural History), and may now be seen admirably set up in the Reptile Gallery of the Geological Department.

The remarkable frontal spine of Squaloraja has always been described as a dermal structure by those who have referred to it, and has been classed with the shagreen-granules and dentition. After the systematic position of the genus had been determined, its frontal spine was rightly recognized as identical with the spine-like frontal process in Chimæra and fossil Holocephala, with which it was formerly compared by W. Davies and A. S. Woodward. Both these processes were regarded as dermal structures by von Zittel, Jaekel, and A. S. Woodward, and treated as true ichthyodorulites, i.e. as if consisting of dentine or vasodentine. In 1890 the present writer briefly pointed out that the frontal spine of the Jurassic Chimæroid, Ischyodus avita, consisted of extremely calcified fibro-cartilage, resembling that of the so-called “claspers” of all male Elasmobranchs. The microscopical structure of these parts differs conspicuously from that of the calcified granules in the common (hyaline) cartilage of the internal skeleton, and its ontogenetic development is different.

The rarity and imperfect preservation of the fossils in the upper part of the Lower Greensand, in the south-east of England, has always added considerably to the difficulties in the study of that series. The Atherfield Clay and the Hythe Beds both have well-marked faunas, though fossils are often absent from the latter. The palæontological evidence is, however, much less satisfactory in the case of the two uppermost of the four divisions into which the Lower Greensand is usually divided. A fair number of fossils occurs in these at Folkestone, but further to the west the lithological nature of the beds changes, and fossils are found in but few localities.

By the death of Professor Huxley another illustrious name must now be inscribed on the walls of our Valhalla, while the world of science mourns the loss of one of its most distinguished leaders, who shares with Owen and Darwin the reputation of having done more to advance the study of biology than any other of the naturalists who have appeared within the present century.

The skeleton of Pareiasaurus Baini, which I brought from the Bath near Tamboer Fontein, in Cape Colony, is shown in the accompanying photograph of the right side of the specimen, as it is now mounted in the British Museum. It is the only known example of the group of animals to which it belongs, in which almost every part of the skeleton is shown. The Dicynodonts were familiar to us from the discovery of many skulls; the Theriodonts were mostly known from snouts; and the Pareiasaurus, although originally described from skull remains, had become known from the fine axial skeleton of P. bombideus, which Mr. Thomas Bain sent to the British Museum many years ago. I therefore entertained hope that the limbs and other missing parts of the skeleton might reward personal exploration in the country. The area to be examined was clearly defined as lying approximately between the Prince Albert Road Station and Fraserberg; for Dr. W. G. Atherstone had found the type of the species near the former locality, and Mr. Bain had found the specimen described by myself in 1887–8 at Palmiet Fontein, at the foot of the Nieuwveldt Range, towards the latter place.

As has been previously indicated (see p. 439), the conclusion might be drawn from Moberg's description and figures of this species, interpreted by the knowledge of the true structure of the Didymograptus polypary, that the structure of the proximal part could in no essential particulars be separated from that just described in D. minutus, Mut. Consequently the genus Isograptus, which was proposed by Moberg for the species in question, is not authorized—at least, as founded on any of the characters cited by Moberg. The differences between Isograptus and Didymograptus, to which latter genus the species is referred by Nicholson, ought to be, according to Moberg, that in Didymograptus “both stipes arise at somewhat different levels on the sicula,” and that “each branch is itself bilaterally symmetrical”; whilst, on the contrary, in Isograptus the stipes should “arise bilaterally symmetrical from the sicula,” and each branch is not itself bilaterally symmetrical. As we have seen above, in reality in Didymograptus the left stipe is not bilaterally symmetrical, and the symmetry in the right stipe is entirely the same as that which is described by Moberg in Isograptus, namely, obliquely near the base, because the stipes do not arise from the side of the sicula, but from the “connecting” canal.

The knowledge of the internal structure and development of the different forms of Graptolites is very incomplete, owing to the unfavourable method of their preservation, Graptolites, in almost all cases, being found embedded in shale.

In the previous portion of this paper, which appeared in the January Number, I examined the form in which Croll presented the astronomical theory of the Ice Age and endeavoured to show how absolutely unsound his argument is. It is, however, at least as necessary to discuss the form in which Sir Robert Ball presents it; for much of the recent success of the theory, outside the school of modern geologists, was due to the weight naturally attached to the fact that a writer of Ball's scientific eminence believed he had so materially strengthened Croll's astronomical argument, that had Croll himself been aware of its full force, he would not have felt bound to call in such auxiliary agencies as a diversion of the Gulf Stream from its course. If, then, the theory, as presented by Croll, was able to win its way with such success among scientific authorities, it must surely be irresistible in the new and more powerful form. But it will be seen that, so far from strengthening Croll's position, Ball's statement weakens it very materially.

The great group of the Ammonites (using that term in its general acceptation) is distinguished from all other kinds of chambered shells of the Cephalopod type by the complicated foliations of the margins (sutures) of the partition walls or septa into which such shells are subdivided. Though typically coiled, much in the manner of the flat pond-snail, Planorbis, there are straight and variously curved Ammonites; but all have the common character of a highly foliated “suture-line.”

It is evident that neither Barrande nor Davidson, who maintained the opinions I have summarized till the last in their publications, were able to recognize the evidence deducible from a study of the Brachiopoda favourable to the theory of their evolution.

The question of the origin of Eozoon Canadense has been recently revived in an important and most interesting paper on a similar structure in blocks of limestone ejected from Vesuvius. The writers, however, of that paper evidently found that more information existed as to the microscopic structure of the Canadian Eozoon than as to its mode of occurrence, so that a few notes on this subject may be of some use as a contribution to the discussion. I visited one of the most noted localities for Eozoon—Côte St. Pierre—in 1884, when I had the inestimable advantage of being conducted by Sir J. W. Dawson, to whose unwearied kindness and hospitality I was so often indebted during my stay in Canada. I made careful notes and rough sketches of what I saw, collected a fair suite of specimens, and paid especial attention to the relation of the structure to other parts of the rock-masses. Upon the question of the origin of Eozoon I do not purpose to enter: I shall restrict myself to stating facts of which, as it seems to me, account must be taken in all attempts to interpret this extraordinary structure.

Hyænodon is one of the genera of fossil mammals which has been for a long time imperfectly known. Excellently preserved skulls have been described and figured by Leidy and Filhol, and some of the limb-bones and vertebræ by De Blainville and Schlosser. Material was, however, lacking for a satisfactory restoration of any of the species, and the specific refeŕence of the scattered bones found has always remained more or less uncertain. In the season of 1894 Mr. Hatcher had the good fortune to discover in the White River beds (Oligocene) of South Dakota a number of remarkably fine specimens pertaining to several species of Hyænodon, which at length enable us to gain an idea of the appearance of this most remarkable animal.

While the favourable reception which the Astronomical Theory of the Ice Age has met with among scientific men has been chiefly due to the writings of Dr. Croll, its more general acceptance, especially among the semi-scientific public, has been greatly assisted by the lucid and vigorous exposition by Sir Robert Ball, in his “Cause of an Ice Age,” published in 1891. But notwithstanding the apparently exhaustive way in which Croll discusses the problem, and the fact that Sir Robert Ball's work has been published in the “Modern Science” Series (indicating that the theory has secured a place among the permanent acquisitions of science), I venture to think that a careful examination of the problem will show that the theory is but a vague speculation; clothed, indeed, with a delusive semblance of severe numerical accuracy, but having no foundation in physical fact, and built up of parts which do not dovetail one into the other. The following pages contain what I hope will be admitted to be a justification of this sweeping condemnation. The first portion of my paper deals with Croll's form of the theory; the second, to be published next month, deals with Sir Robert Ball's form.

It may be fairly asserted that increased geological interest attaches to the deeper workings of the Kimberley Diamond Mines as they proceed. The remarkable development of underground mining, following upon the amalgamation of interests, which was the outcome of the collapse of the surface workings in 1886, or thereabout, has offered better opportunities for observation, not only of the diamond matrix-material but also of the varying characteristics of the neighbouring rock formations.

During last August the writers made a short stay in Switzerland and the Savoy, with a view to examine the structure of the ice of several of the larger glaciers. For this purpose a rough polariscope was used. It was so designed that a sheet of ice about two inches square, made very thin by cutting and melting, could be placed between the polarizer and analyzer. Notwithstanding that the thin slide so prepared, and held between glass plates, melted away rather rapidly, we succeeded in making a number of drawings of sections cut from the ice at different parts of the glacier, and at various angles with the line of motion. In some cases, however, where the structure was very fine-grained, the samples melted away before they could be sketched.