In the Geological Magazine for April, 1895, p. 152, the results of some observations made by Mr. George Fletcher, F.G.S., and myself on the structure of glacier ice were given.

Thin plates of ice were made by cutting and melting, and then examined in polarized light. In all cases it was found that the individual crystals were in close contact, there being no evidence of the presence of a eutectic separating them. The crystals in the same piece varied very greatly in size, and had very irregular outlines.

As the sections which we figured were in all cases drawn by hand, I thought it advisable to construct a special form of instrument with which to obtain actual photographs of thin sections of glacier ice. The instrument eventually used consisted of two bundles of thin glass plates, one being used as a polarizer and the other as an analyser. They were fixed vertically above each other, and between them was the glass stage upon which the thin ice sections rested. Below the analyser was a small lens throwing the image of the ice section upon a photographic plate.

Last Summer, accompanied by Mr. H. Arnold-Bemrose, M.A., F.G.S., who kindly assisted me in the matter, I visited the Furka Pass, and we obtained photographs of the ice of the Rhône Glacier.

Figs. 1 and 2 are full-sized photographs of thin slices of ice. Samples with small crystals were selected, so as to bring many crystals within the limits of the field. The ice section was about 03 inch thick, and where the surface between two crystals is at an angle with the glass plate upon which the ice section rested, interference fringes are consequently to be seen.

The Sparassodonta are an interesting group of extinct mammals found in the Tertiary formations of Patagonia. They appear to have taken the place of true Carnivora in South America during most of the Tertiary period, as the Carnivorous Marsupials do in the modern fauna of Australia. Their relationship has been in dispute since they were first made known to science by the distinguished South American paæontologist Florentino Ameghino. In dental formula and other characters of the teeth and jaws they agree with the Carnivorous Marsupials, and show a high degree of adaptive specialization for predaceous habits. Dr. Ameghino was able to determine, however, from specimens in his collection, that the replacement of the premolars, in certain genera at least, was more complete than in modern marsupials, and approached that of the placental carnivora. He regarded them, therefore, as an intermediate group, ancestral to the Creodonta and modern Carnivora. Mr. Tomes, in his interesting study of thb enamel structure of the Creodonta and allied groups, has recently shown that in one genus of Sparassodonts the enamel shows the more highly differentiated structure of the true Carnivora, instead of the more primitive structure of Marsupial Carnivores. The collections made by the Princeton and American Museums in the Santa Cruz formation of Patagonia contain a splendid series of Sparassodont remains, including skulls and skeletons of the principal genera, which have recently been exhaustively studied by Dr. Sinclair. These show that the Sparassodonts agree with Marsupials, and especially with Thylacinus in almost all the distinctive features of dentition, skull, and skeleton characters by which they are separated from the placental mammals.

On several previous occasions the author has described in the pages of the Geological Magazine certain fossils from so-called “Slade Beds” from the roadside near St. Martin's Cemetery, Haverfordwest. A large collection of fossils has been made by Mr. V. M. Turnbull from this particular locality during the last few years and presented to the Sedgwick Museum. From a prolonged study of this material and comparison with the typical fauna of the Slade Beds as described by Messrs. Marr & Roberts, the conclusion has been forced upon me that we have here to deal with a higher palæontological horizon than the true Upper Bala of this district, and that there is much more reason for putting it in the Silurian than for keeping it in the Ordovician. The stratigraphical evidence which has subsequently become available is in support of this view. A list of the fossils from this bed may be useful at the present moment, particularly as the Sedgwick Museum possesses by far the most extensive series which has been collected from it (see opposite page, 537).

The rock in which they occur is a greenish-grey, fine-grained, argillaceous mudstone with occasionally minute specks of mica and a little arenaceous material, but usually of a very uniform smooth texture. It breaks in an irregular, often subconchoidal manner, and is devoid of any regular or weil-marked planes of division. Exposed surfaces and the fossils themselves are generally more or less iron-stained. In appearance and general characters it is difficult or impossible to distinguish the rock from the higher beds of the Slade Series, but the fauna is completely different.

The fossils which Mr. V. M. Turnbull has collected from supposed Slade Beds on the “roadside near St. Martin's Cemetery, Haverfordwest,” were obtained along the north side of a road leading westward from St. Martin'ls Cemetery to Portfield House, on the west aide of the town. About half-way between the Cemetery and Port-field House the road is crossed by a by-road known as Jury Lane; one of the fossiliferous localities lies 110 yards east of Jury Lane crossing, another is 100 to 150 yards west of it. The area in question is contained in the Old Series one-inch Geological Survey map, Sheet 40, the New Series one-inch map, Sheet 228, and in the six-inch map, Pembrokeshire, Sheet 27 N.E.

For some years past a Committee of Littleborough and Rochdale geologists, consisting of Messrs. W. H. Sutcliffe, Walter Baldwin, W. A. Parker, S. S. Platt, and others, have devoted themselves to the task of working out the beds of shale containing clay-ironstone nodules, a portion of the Middle Coal-measures at Sparth Bottoms, half a mile south-west of Rochdale Town Hall, in beds estimated to occur 135 feet above the Royley Mine Coal-seam.

In the clay-ironstone nodules occur well-preserved ferns, Calamites, Sigillariœ, shells of Carbonicola acuta and other Coal-measure lamellibranchs, whilst the number of Arthropoda obtained is probably unsurpassed in any locality of this formation.

The first Arthropod obtained from Sparth Bottoms was noticed by Mr. Walter Baldwin, F.G.S., under the name of Prestwichia, rotundata, Prestw., sp. (Trans. Manch. Geol. Soc., vol. xxvii, part 6, 1901, pp. 149–155, with a plate); the second in 1903, by the same geologist, who identified it as Bellinurus bellulus, König (op. cit., vol. xxviii, part 8, pp. 198–202). The third and most important discovery was made by Mr. W. A. Parker, F.G.S., namely, a new species of fossil Scorpion, which was described and figured in 1904 by Messrs. Baldwin & Sutcliffe under the name of Eoscorpius Sparthensis (Quart. Journ. Geol. Soc., vol. lx, p. 396, fig. 2). These geologists have continued their researches, of which a brief account was given by me at the York Meeting of the British Association (1906). Many subsequent finds have been most obligingly confided to me by these gentlemen, and through the kindness of Mr. W. H. Sutcliffe the specimens figured have since been presented to the Geological Department of the British Museum (Natural History), the only condition imposed being that they should be described.

The projecting mass of land between Tramore Bay and the mouth of the River Suir consists of Old Red Sandstone, and the cliffs are mostly high, bold, and precipitous. The valleys which descend to the sea are more or less filled with Boulder-clay and other drift materials, testifying to their pre-Glacial oxcavation. The geological history of these valleys and of the large shallow lagoon lying inside the long spit of sand dunes which nearly cuts off the head of Tramore Bay deserves a separate article, and we will therefore here commence with the description of the eastern shore of this bay stretching from Summerville to Brownstown Head. Messrs. Wright & Muff in their paper on the pre-Glacial shore-line of the South of Ireland made no reference to this portion of the Waterford coast.

The cliff below Summerville House is composed of the usual type of Boulder-clay of the district, but devoid of any large boulders; it is capped by 4–8 inches of whitish to yellow marl without any stones; above this comes 1–2 feet of wind-blown sand immediately beneath the thin soil. The Boulder-clay here is only about 6 feet thick, and the total height of the cliffs is only 8–12 feet. The line of these drift-formed cliffs recedes inland behind the large triangular area of grass-grown hummocky land which projects seawards at Bass Point; this area represents a comparatively recent accumulation of sand which has been built outwards for some 200 yards from the base of the cliffs so as to narrow the channel of Rinnashark Harbour leading into the Back Strand lagoon.