Matherella (?) acuticostata sp. nov. is described from the Lower Ordovician of Trefor, near Bryngwran, in mid Anglesey.

In this paper I purpose giving a few examples to show the powerful influences which have been exerted by Earth-movements in producing changes in the rocks, and in obliterating the evidences of succession in some of the disturbed areas in Wales and Shropshire. For a long time past it has been well known that certain changes such as cleavage, etc., have been induced in the rocks in Wales and elsewhere by pressure, but only of late years has the magnitude of the results due to Earth-movements been fully understood.

Stromatolites found in Karagwe-Ankolean rocks on the Tanganyika-Uganda border occur in siliceous beds associated with cherty and ferruginous breccia without trace of calcareous material. Somewhat similar conditions prevail in beds of the Singo Series of Uganda from which Collenia-type structures have been recorded. Little stratigraphical value can be ascribed to the structures, but they are significant in pointing to the replacement character of some fine-grained siliceous beds which may explain the scarcity of limestone in the Pre-Cambrian sequence of Uganda.

Phonolite lava from the Viejo and Teide volcanoes show a wide variation in flow morphology, from viscous, spoon-shaped lavas to thin flows more than 8km long that often show well developed lava channels. The apparent fluidity of these lavas is considered to be largely due to their strongly alkaline character.

The valuable paper by Professor Harkness on the Middle Drift deposits of Great Britain does not include a notice of their occurrence in Cheshire. About six years ago, a paper of mine on this subject was published in the Reports of the Geological Society of Manchester. I revert to it again, inasmuch as the only locality little dwelt on by Professor Harkness bears out so thoroughly the chief peculiarity about the beds in question.

Over the area in question the total thickness of the Chalk (where it can be measured from top to bottom, or nearly so) varies from 623 feet at Streatham to 1146 feet at Norwich, and in the latter case the topmost beds are absent; so that the full thickness, in some parts of Norfolk, may be 1200 feet or more. This figure, however, is exceptional, the nearest to it recorded being 890 at Harwich [this should probably be 895, the Glauconitic basal bed having been called Upper Greensand]. At East Horsley, in Surrey, a thickness of 817 feet has been proved, but generally speaking we find less, and over a large area 700 feet is not reached. It seems that the Chalk thins toward London (where 650 feet may be taken as about the usual thickness), not only from north and south but also from east and west. [It may be well to add the thicknesses proved by other borings outside London. These are as follows, where the borings have passed through the whole formation, from the overlying Tertiary beds to the underlying Upper Greensand or Gault:—Loughton 651 feet, Richmond 670, Cheshunt 681, Chatham and the neighbourhood 680–684, and Winkfield, near Windsor, 725. In sundry places where the topmost beds are missing we have the following:—Bushey (Herts) 686, Chartham (Kent) 735, and Coombs (Suffolk) 817, which last-mentioned should probably be over 820, for the same reason as given above, for increase at Harwich.]

In the Geological Magazine, August, 1904, pp. 392–403, Dr. Wheelton Hind describes the Lower Culm beds of North Devon and assigns them to the ‘Pendleside’ series.

From the original paper dealing with that series I gather that in the North of England the ‘Pendleside’ beds lie above the uppermost zone of the Carboniferous Limestone, and are the equivalents of the Millstone Grit of the South Wales and Mendip areas. Dr. Hind's contention is, then, that the Lower Culm of North Devon was laid down at a time subsequent to the deposition of the whole of the Carboniferous Limestone of the Mendips and South Wales.

Recently, when examining some weathered fossiliferous limestone shale from the Lower Carboniferous strata of East Kilbride, Lanarkshire, my attention was attracted to some fragments of the valves of Spirifera trigonalis, Martin, in which I noticed, on the hinge-line of the dorsal valve, a row of small, round, hollow pits, and on the hinge-line of the ventral valve, a corresponding row of small, projecting, rounded denticles. These characters I had not noticed before, and on searching further, I found other fragments of the valves showing the same thing. This led to an examination of more perfect specimens of this Spirifera, contained in my own collection, and that of Dr. J. R. S. Hunter, of Braidwood, Carluke, and in one example, where the valves had slightly opened through pressure, on clearing away the shale, I found, on the outer edge of the ventral valve, a distinct row of small projecting denticles, that had evidently fitted into hollow pits or sockets in the dorsal valve, but from the way the valves had shifted in this specimen these were not seen. These denticles, when looked at externally, are nearly as numerous, and much of the same size, as those seen in many of the hinge-lines of shells of the genus Area, only in this genus, the teeth are the same in each valve, and lock into each other.

The possibility of change in the position of the Earth's axis seems periodically to attract attention. This is happening now. Professor Haughton has written upon this subject, Sir William Thomson has alluded to it, while two important papers have been read upon it, one by Professor Twisden before the Geological Society, the other by Mr. George H. Darwin before the Royal Society. This article is an endeavour to exhibit to the general reader the assumptions with which they have started, and the results they have obtained.

Knowledge about marine reptile diversity and disparity during the Late Jurassic is increasing. This contribution describes marine reptile skeletal elements (ichthyosaur and plesiosaur) from Kingofjeld mountain in NE Greenland. The assemblage is early Late Oxfordian (Late Jurassic) in age, and consists of c. 100 disarticulated skeletal elements. The location is of biogeographic importance as it was at the time situated between the Boreal realm and the Tethys Sea and is promising in terms of future prospecting.

THERE has been considerable uncertainty about the true characters of the species Illaenus bowmanni Salter, and many foreign palaeontologists have consequently found it difficult to institute a close comparison of it with other species and have suspected its composite nature. As Holm and Warburg have remarked, the species is badly characterized, and some important critical features, such as the shape of the caudal fascia, are ill-defined or not clearly described in the definitions or well represented in the figures. The poorness of the specimens is largely accountable for these omissions. A recent detailed investigation which the author has been enabled to make of the specimens used by Salter, Portlock, and McCoy in drawing up a definition of the species, together with the examination of many other specimens ascribed to it from the original and other localities, throws some useful light on the subject and helps to clear up some of the obscure points, but it also shows that most of the earlier and current synonymies and references which have been published from time to time are untrustworthy and inaccurate.

The subject of denudation is so important that I propose giving a few instances of denudation and of the transport of material that have actually come under my own observation or that of my friends. Where one sees the same familiar crags and pinnacles year after year, apparently quite unchanged, one may perchance fancy that denudation is at a standstill; but anyone who, in scrambling across the screes that clothe many a steep hillside, finds them moving beneath his feet, or perhaps has clattering about his ears a shower of stones dislodged by some wandering sheep, will at once perceive that it is not so: for it is obvious that if the mere tread of such a small beast as a sheep, shepherd or other pedestrian, can set scree rolling downhill, it must be in a very unstable state, and may be expected to move in a conspicuous manner under more potent forces than the tread of animals. Observation shows that this is the case. Not a year passes without some conspicuous fall of scree or of solid rock, owing chiefly to great downpours of rain. Leaving general statements, I will now give actual instances of the fall of rock or movement of scree that have recently taken place in the Snowdon district.