In various numbers of the “American Journal of Science,” the writer has given the more important characters of the skeleton of the Stegosauria, and has indicated the relations of this group to the other known Dinosauria. The discovery of additional specimens of Stegosanrus, one of them nearly complete, furnishes material to greatly enlarge our knowledge of the skull and dermal covering of this genus, and some of the new facts are given in the present article.

The uppermost limestone stratum of Gotland, which occupies two-thirds of the surface of this island, and is homotaxial with the English Upper Ludlow, contains such numerous fragments of Cephalopoda, that it has been called the Cephalopodan Limestone. Judging from the collection in the Paléontological Department of the Swedish State Museum, the number of species of Cephalopoda from the different strata of Gotland can hardly fall short of 200, most of them in a very perfect state of preservation, some even retaining the surface ornamentation and colour. Amongst them the genus Ascoceras (including Glossoceras), with its nine species, is the most remarkable. As the Museum has succeeded in obtaining specimens showing its morphology more completely than has hitherto been known, a few remarks on it may be made in advance of a monograph now in preparation.

In their great work upon the Palæozoic Corals (Polypiers Foss. des Terr. Pal. p. 252, pl. 17, figs. 3, 3a, 1851) Milne Edwards and Haime describe and figure, under the name of Michelinia geometrica, a remarkable little Coral from the Devonian rocks of France. By the kindness of Dr. Daniel Œhlert, of Laval, whose researches upon the stratigraphy and palasontology of the French Devonian rocks are well known, I have been enabled to examine some well-preserved examples of this interesting form, and have determined some new facts as to its internal structure. Investigation by means of thin sections has, in fact, shown that this Coral has in reality no close relationships with the genus Michelinia, but that its affinities are rather with Protarcea, E. & H. It differs, however, in important structural features from Protnræa, and appears to form the type of a new genus to which the name Cleistopora may be given.

It is unnecessary for me to remind the readers of the Geological Magazine of the evidence for elevation and subsidence. For my present purpose it is sufficient to remind them that suoh elevation and subsidence has been attributed (1) to lateral pressure giving rise to long geo-anticlines and geo-synclines; (2) to expansion and contraction of the underlayers resulting from a rise or a fall of temperature; and (3) to the loading and unloading of the areas of the earth's crust affected. Apparent elevation and subsidence, which we may here neglect, may be due to a rise or fall of the sea-level such as is dealt with by Prof. Hull in a recent communication to this Magazine.

In the year 1884 a paper of mine, entitled “The Geology of Monte Somma and Vesuvius,” was published (Quart. Journ. Geol. Soo. vol. xl. pp. 35 to 119), in which I proposed a new explanation for the peculiarities in form of this volcano. An endeavour was made to show that the truncation of Monte Somma by the series of explosive eruptions, especially of Phase VI., had occurred around an eruptive axis different from that which belonged to the period of vesuvian activity, by which the original Somma cone had been built up. Furthermore, a law was enunciated, which is applicable to a very large number of volcanoes, of which, even in Italy, the following examples may be taken in their order of perfection, viz. Eoccamonfina, Mt. Vultura, Etna, Stromboli, Vulcano, and some of the Roman ones. The following are some of the words used: “There is very good reason to deny the concentricity of the great, crater of the Atrio with the original cone of Monte Somma. If within a cone we scoop out an inverted conical hollow around an axis eccentric, but parallel, to that of the solid, we shall have the included space bounded by an annular ridge, not horizontal, but sloping down in the direction of the axis of excavation, and inclined proportionally more, the further the axis of excavation is removed from that of the solid.

Some new species having been found in the Isle of Wight during the lately renewed examination of its geology by the Geological Survey, and the known Wealden species of that island not having been hitherto so distinctly indicated as might be, it is thought advisable to give some notes on, and a resume of, this interesting series of fossil species.

Some time since a student of University College, Mr. J. Hale, of Ivy Hatch, brought to me specimens of an extremely hard green sandstone, which he informed me came from the Folkestone Sand stage near Ightham, in Kent. As the microscopic structure proved rather interesting, I lately visited the locality in his company, and had the additional advantage of being conducted by Mr. B. Harrison, of Ightham, so well known for his discoveries of palaeolithic implements and for his minute knowledge of the geology of the neighbourhood.

Having lately had the privilege of visiting several of the Continental Museums containing collections especially of Palæontological importance, some notes will perhaps be acceptable upon the present aspect of that branch of the science in which the writer is particularly interested. Such a broad survey imparts so many new ideas, and leaves so many pleasant memories of Naturalists in the midst of their work, that it is impossible adequately to incorporate the results in any brief notice; but a few points at least seem to be of general interest.

As a text for the following brief remarks on the recognition of mural pores in thin sections of the Favositoid Corals, I may quote a note appended by Mr. James Thomson, F.G.S., to a recent paper on the genus Lithostrotion (Trans. Edin. Geol. Soc. vol. v. part iii. p. 381). The note in question is subjoined, the quotation being verbatim, and, I may add, literatim also:—

“We may, however, attach an undue importance to microscopic examinations. Need I refer to the point raised recently by that erratic and energetic worker, Prof. Alleyne Nicholson, regarding mural pores in the genus Alveolites, the type of which is also in Dr. Fleming's collection. If he had detected mural pores in microscopic sections, we would have regarded such as being one of the greatest discoveries of modern times.

The genus Actinoceras was founded by Bronn in 1837, upon Dr. Bigsby's figures in the Transactions of the Geological Society; the chief distinguishing character being the possession of a large, dilated, and segmented siphuncle, filled with radiating deposits. The presence of a smaller internal tube with tubuli radiating therefrom and communicating with the septal chambers through the wall of the siphuncle. had not then been observed.

Previous observations in British Columbia have shown that at one stage in the Glacial period—that of maximum glaciation—a great confluent ice-mass has occupied the region which may be named the Interior Plateau, between the Coast Mountains and Gold and Eocky Mountain Kanges. From the 55th to the 49th parallel this great glacier has left traces of its general southward or southeastward movement, which are distinct from those of subsequent local glaciers. The southern extensions or terminations of this confluent glacier, in Washington and Idaho Territories, have quite recently been examined by Mr. Bailley Willis and Prof. T. C. Chamberlin, of the U.S. Geological Survey. There is, further, evidence to show that this inland-ice flowed also, by transverse valleys and gaps, across the Coast Range, and that the fiords of the coast were thus deeply filled with glacier-ice which, supplemented by that originating on the Coast Range itself, buried the entire great valley which separates Vancouver Island from the mainland and discharged seaward round both ends of the island. Further north, the glacier extending from the mainland coast touched the northern shores of the Queen Charlotte Islands.

Mr. Adolph Hoffmann has kindly sent me a large series of fossil plants from the Tertiary strata of Leoben containing a very rich fossil flora. On examining the latter, I discovered a fossil leaf, which I at once recognized as a Cycad.

Remains of that family of plants are extraordinarily rare in the Tertiary strata of Europe. They are limited almost entirely to the Eocene formation. The occurrence, therefore, of such a fossil in the Tertiary flora of Leoben, which belongs to the Miocene period, calls forth the greatest interest, and I shall not fail to give a preliminary notice on the subject to palaeontologists.

In the Thirty-Sixth Annual Eeport on the New York State Museum of Natural History (8vo. Albany, 1884), is a folding plate with a fly-leaf descriptive of a specimen with peculiar structure from the Calciferous Sandstone group of Greenfield, Saratoga Co. referred to a new genus and species under the name of Cryptozoon proliferum, but no author's name appeared to either the plate or the description. The peculiar appearance of the American figure reminded Prof. Eupert Jones of a specimen in his collection, and having kindly placed it in ray hands and permitted me to bring it before the notice of the readers of the Geological Magazine, he has given it to the British Museum. Prof. Jones's specimen was collected by the late John Calvert, F.G.S., the author of “Vazeeri Rupi, the Silver Country of the Vazeers in Kulu,” and the rock is referred to at p. 8 of that book. The specimen was shown by Mr. Calvert to Sir Warington W. Smyth (whose opinion as to its inorganic nature is quoted by Mr. Calvert), and afterwards given to Prof. Jones.

During Professor Hughes' annual geological excursion, which was last Easter conducted to Ilfracombe, I was much struck with certain structures exhibited by the ordinary Devonian sediments, and some of these are, I think, worthy of a short notice. Most of them are exhibited on the beach close to Ilfracombe, at the bathing place, where there is also seen the folded grit band rendered classical through Dr. Sorby's writings.

I Have read with great pleasure Mr. R. D. Oldham's interesting article in this Magazine, for October, 1887, on the gneissose rocks of the Himalayas. Mr. Oldham concurs with me in assigning an eruptive origin for the more or less gneissose rocks at Dalhousie, the Chor, and for almost all those in the Satlej Valley; and as I have in my published papers expressly intimated “my belief that some of the crystalline rocks of the north-western Himalayas are metamorphic gneisses” (Records Geol. Surv. India, vol. xviii. p. 110), I see no grounds for dissenting from his observations regarding the latter class of rocks.

That many of the Palaeozoic limestones are more or less exten sively composed of the skeletons of various Invertebrate animals, sometimes in a perfect condition, sometimes more or less largely fragmentary, has long been known.incertain instances a microscopic investigation of these ancient calcareous sediments may fail to demonstrate the presence of organic remains, or may reveal but few of these. Thus there occur beds of lithographic limestone in the Palceozoic series which would seem to be simply of the nature of very finely levigated calcareous mud, the component grains of which were, however, doubtless derived, in the first instance, from the calcareous skeletons of animals.

In view of the active discussion of the problems of earth-movement and mountain-growth now current, certain fundamental definitions, growing out of the discrimination of processes commonly confounded but really distinct, seem to be timely.

The various processes with which the geologist has to deal fall naturally into two principal and antagonistic categories and five subordinate and supplemental categories; and each category, great and small, comprises two antagonistic classes of movements or agencies.

The following abstracts of early papers, on the Cefn Caves, throw a most interesting light on the sequence and method of occurrence of the deposits found at the Tremeirchion Caves, which are four miles east-north-east of them, and on the opposite side of the Elwy and Clwyd valley.

In Mr. Sorby's presidential address at the anniversary meeting of the Geological Society in 1879, attention was drawn to the fact that the carbonate of lime in calcareous organisms is in certain cases in the form of calcite, in others of aragonite, and various genera of such organisms were classed according to their mineralogical constitution. It was also shown that aragonite fossils are of greatly inferior stability to those formed of calcite, in many deposits casts only of aragonite fossils being preserved, whilst those of calcite remain unaltered. In the same address Mr. Sorby insisted on the importance of this difference of stability as affecting the trustworthiness of the geological record.

A Recent examination of the remains of Tertiary Lacertilia and Ophidia preserved in the British Museum having brought to light some new facts in regard to distribution, and also indicating the necessity of revision of certain determinations of other authors, I have thought it advisable to communicate the result of my observations in a collective form.