appear on the Survey map as greenstone, between St. Ishmael's on the E., Dale on the S., Wooltack Park on the W., and Musclewick Bay on the N., including also Midland Island and part of Skomer. The rock seen in a small quarry at Crabhall was described by Mr. Teall as a somewhat basic porphyrite. What appears to be the same rock is found exposed in several places on the opposite side of the Mullock stream. At Marloes Sands the continuation of the Crabhall rock appears in the cliff as a black dense rock much traversed by quartz and epidote. Microscopically it is a perfect dolerite, generally ophitic in structure with plagioclase in augite plates, but sometimes granular; there seems to be some hypersthene, and serpentine is present, probably after the same mineral. From Marloes Beacon this rock seems to continue, until it appears in contact with Llandeilo rocks in Musclewick Bay. The rock found here, however, is shown by the microscope to be a felsite (probably a soda felsite), and not a variety of the dolerite. At Martins Haven the same ophitic hypersthene dolerite is found which occurs at Marloes Beacon and in Marloes Bay. IV. Age of the Igneous Rocks.-The age of these rocks appears to have been regarded by the Survey as post-Carboniferous, while some of them at any rate have been claimed by Dr. Hicks as pre-Cambrian. The felsites in the Benton area are almost entirely associated with beds of Old Red Sandstone, and there does not seem to be any satisfactory evidence of intrusion. Such a continuous mass of quartz felsite, with well-marked spherulitic and fluxion structure, seems to suggest rather a flow than an intruded mass. On this supposition the beds must be at least post-Silurian. The rocks from Llangwm to Talbenny are in almost every instance associated with Llandovery beds on the one hand and Carboniferous strata on the other. The Carboniferous strata are reversed in dip, and the line of junction is in our opinion a line of thrust. The evidence seems to indicate that the rocks are not post-Carboniferous, the Culm measures being apparently unaltered near the junction, and that, judging by lithological character, they did not occupy their present position as a ridge in Llandovery, Old Red, or Carboniferous times. With regard to the southern area we could not find clear evidence of intrusion, all the chief junctions appearing to be faulted ones; still there seems to be little doubt that rocks microscopically similar rest on different measures of Silurian age. Grassholme, a small island about seven miles from the mainland, but rarely visited, appears to be the continuation of the ridge from Wooltack Park and Skomer towards the S.E. corner of Ireland. No clastic rocks were found, the main rocks being ophitic dolerite, with corroded augite and some bands of secondary epidote and quartz. 7. Notes on a Hornblende Pikrite from Greystones, Co. Wicklow. [Communicated by permission of the Director-General of the Geological Survey.] In this paper the author gave a description of a rock which forms a dyke in the Cambrian slates and grits of Greystones, in Co. Wicklow. It is a dark, dense, coarsely crystalline rock, showing large crystals of hornblende with lustre-mottling, owing to the weathering-out of olivine crystals. It becomes finer-grained at the margins. An analysis by Dr. Sullivan was added. The hornblende is of the usual green type, and occurs in large crystals enclosing pseudomorphs of olivine, now made up of magnetite and probably a colourless amphibole. A colourless hornblende also occurs either as cores or borders to the green crystals. A third type of hornblende present shows few cleavage cracks and much magnetite dust. Apatite is a constituent, but there is no felspar in the rock. The margin of the dyke is much sheared and phacoidal in structure. 8. Report on the Registration of Type Specimens of Fossils. See Reports, p. 482. MONDAY, SEPTEMBER 18. The following Papers were read : 1. A Discussion on Coral Reefs, Fossil and Recent, was 2. Twenty Years' Work on the Younger Red Rocks (Permian and Trias). By Rev. A. IRVING, D.Sc., B.A., F.G.S. The author reviews the work done by himself and in collaboration with other geologists on the Permian and Trias since he commenced the study of them in the North Midlands more than twenty years ago. He shows why the use of the term 'Poikilitic' and its connotation was given up by him after further work in Britain and in Germany; that it is necessary to recognise (as the earlier writers had done) two distinct systems in these rocks; that the strata called 'Bunterschiefer' by Murchison are really the base of the Trias of Central Germany, and are sharply cut off from the Zechstein; that there is a distinct differentiation of the two systems from each other on physical as well as stratigraphical grounds, on account of the great difference as to the derivation of their materials in the relation the Permian and Trias bear to the adjacent older land. The chief results of the author's work on the Red Rocks of Devon in the years 1887-1892 are then summarised; further evidence of the contemporaneity of the volcanic rocks and the breccia-sandstone series is given; and attention is drawn to the new edition of the 1-inch map of the Geological Survey, on which the Permians of Devon, as described by himself, are delineated. He regrets that he is not able to accept (for reasons given in his published papers) the delimitation of the Keuper, at the expense of the Bunter, which is adopted on that map, the base of the Keuper having been traced in the valleys of the Otter and the Sid. Sections are added (i.) at Saltern Cove on the west side of Torbay; (ii.) at Kimberley, Notts, in which there is the plainest evidence of great unconformability between the Dyas or Permian and the older Palæozoic rocks. The author concludes with a note on the probable physical history of the series of strata under consideration. The following are the more important papers of the author herein referred to:'The Geology of the Nottingham District' (Proc. G. A., vol. iv.); Classification of the European Permian and Trias' (Geol. Mag., 1882); 'Triassic Deposits of the Alps' (Ibid., November, 1882); The Dyas and Trias of Central Europe' (Q. J. G. S., August, 1884); The Permian-Trias Question' (Geol. Mag., July, 1884); Report on the Permian and Trias' (International Geol. Cong., London, 1888); 'The Red Rocks of the Devon Coast Section' (Q. J. G. S., February, 1888); Supplementary Note' on the same (Ibid., February, 1892); 'The Base of the Keuper in Devon' (Ibid., February, 1893). See also the following papers: H. B. Geinitz,' On the Limits of the Zechstein,' &c. (Nova Acta Acad. Leop., Dresden, 1885), and summary of the same by A. Irving (Geol. Mag., May, 1885); E. Hall, On the Red Rocks of South Devon' (Q. J. G. S., February, 1892). 3. On the Trias of the Midlands. By Professor C. LAPWORTH, F.R.S. 4. On the Occurrence of Fossils in the Magnesian Limestone of Bulwell, near Nottingham. By Baron A. VON REINACH and W. A. E. USSHER. At Bulwell, near Nottingham, good sections are exposed in stone and brick pits. The stone pits exhibit from 5 to 20 feet of yellowish brown Magnesian limestones, in beds of from 3 inches to 1 foot, with rather irregular surfaces. The limestone is very occasionally compact and sub-crystalline. It consists for the most part of an aggregate of recrystallised materials, giving it the appearance of a sandstone. Very occasionally quartz pebbles of small size are met with in the denser portion. Certain markings on the irregular bed surfaces, which resembled the rude internal casts of molluscs, led us to make a closer investigation, which, from feeble casts and cavities, as if resulting from the solution of shell matter, introduced us to certain proofs of the presence of organisms. These are in a very imperfect state of preservation, but enough of the form remains to confidently assert the presence of Schizodus and of Aucella Hausmanni, forms which characterise the Upper Magnesian limestone. The fossil casts are plentiful, sometimes occurring through the stone for a thickness of 2 or 3 feet. Through their imperfect condition one can only say that the other casts suggested Schizodus Schlotheimi, S. rotundatus, Edmondia, Gervillia antiqua. In brick pits near the stone pits, over a floor of Magnesian limestone, we find a section of from 5 to 15 feet of red marly clay, with pale brown and greenish arenaceous beds and bands in places apparently dolomitic and resembling the Magnesian limestone below. These clays are immediately overlain by the Red sandstone (lower mottled) of the Bunter. Proceeding towards Nottingham sections of Bunter pebble beds are shown, exhibiting their false bedded courses, and containing occasional lines of pebbles or scattered pebbles of hard liver-coloured quartzite and other stones, amongst which we noticed fragments of igneous rock, one quartz porphyry being of a type familiar in Germany and in the Teignmouth breccias of the south-west of England. The marly clay with intercalated sandstones recalls the passage beds of marl and sandstone on the coast between Exmouth and Straight Point, though the latter are more than ten times its thickness. 5. Note on the 'Himlack' Stone near Nottingham. Professor F. Clowes having expressed his opinion at a previous meeting of the Section that the Himlack stone had been formed artificially by quarrying out the rock which formerly inclosed it, the author desired to controvert this statement, and maintained that this remarkable rock was a monument of natural denuding agency, either marine or atmospheric. Some thirty years since, when working on the Geological Survey, he had sketched and described this rock, as will be seen on reference to the Survey memoir 'On the Triassic and Permian Rocks of the Midland Counties' (1869), p. 34. The rock, which is 20 feet high, consists in its upper part of the 'pebble beds,' and in its lower of the lower mottled sandstone,' of the Bunter sandstone; and at the time the memoir was written the author considered the rock to be a remnant of marine denudation, an old sea-stack of the post-Pliocene period. Its great antiquity is evinced by its name 'Himlack,' which is clearly a Celtic word. 6. On the Junction of Permian and Triassic Rocks at Stockport. The Stockport section has for nearly thirty years been regarded as furnishing the typical illustration of an unconformity between the Permian rocks and the overlying Bunter. The Geological Survey memoir relating to the district gives the following three vertical sections : By a fortunate chance boreholes have within the last ten years been put down at each of the localities named; the authors have had opportunities of watching the progress of the work, and the investigation has yielded results entirely different from those previously recorded. At the most easterly exposure a good brook section displays a considerable thickness of the marls. The details of the well sections are as follows: The authors consider that the close correspondence in thickness of the uppermost member of the Permian series in all three sections justifies the opinion that, whatever may be the case elsewhere, there is no evidence of unconformity at Stockport. The facts brought to light have an important bearing upon the question of water supply, and also encourage the expectation that coal may be profitably worked beneath the newer rocks at long distances from the western edge of the Cheshire coalfield. 7. Note on some Molluscan Remains lately discovered in the English Keuper. By R. BULLEN NEWTON, F.G.S., British Museum (Natural History). This communication directs attention to the discovery, by the Rev. P. B. Brodie and Mr. E. P. Richards, of some obscure impressions of lamellibranch shells in the green gritty marls of the Upper Keuper Sandstone of Shrewley, Warwickshire, which form the first evidence of a molluscan fauna from these beds as developed in this country. The matrix appears to be so peculiarly unfavourable for the retention of shell structure that it is doubtful whether any better material than the present will ever be forthcoming. The specimens indicate truly marine types, though on account of bad preservation only three of them could be selected for description as exhibiting certain characters in their contours and sculpturing, which might be of service in ascertaining their probable generic positions. Estheria minuta is the one invertebrate form hitherto recorded from the British Keuper; that is, excluding the Foraminifera described by Professor T. R. Jones and W. K. Parker, which came from an alabaster pit at Chellaston, near Derby, and which were doubtfully referred by the authors to an Upper Triassic age. The very modern facies of the Foraminifera has suggested the highly probable idea that they were derived from superficial deposits. Associated in the matrix containing these molluscan impressions are fragments of cestraciont spines and teeth (Acrodus Keuperinus) and a part of a carapace of the small phyllopodous crustacean, Estheria minuta. The specimens described are identified as (1) Thracia (?) Brodiei (n. sp.). (2) Goniomya Keuperina (n. sp.). (3) Pholadomya (?) Richardsi (n. sp.). Such generic forms as are represented here have not apparently been reported from rocks of a similar period on the Continent or elsewhere. Fifteen specimens and a diagram accompanied the paper. 8. Observations on the Skiddaw Slates of the North of the Isle of Man. By HERBERT BOLTON, Assistant Keeper, the Manchester Museum, Owens College. The Skiddaw slate group of the north of the Isle of Man consists of alternations of quartzites, schists, slates, and bedded volcanic ash, penetrated by intrusive sheets and dykes and ramifying quartz veins. 'On some Fossil Foraminifera from Chellaston, near Derby,' Quart. Journ. Geol. Soc., 1860, vol. xvi. pls. 19, 20, pp. 452-458. North of a line drawn from Port Mooar through Snaefell to Peel, the general dip of the slate is to the north-north-west at an angle varying from thirty degrees to nearly vertical. The lowest beds exposed in this area crop at Port Mooar along the axes of a series of anticlinal folds, which occupy the whole of the bay and extend south to Gob-ny-Garvain. These beds consist of massive iron-stained quartzites and schists overlaid by well-bedded slates. Northwards, by St. Maughold's Head and thence to Ramsey, the slates dip steadily to the north-north-west, the angle of dip varying between fifty and sixty degrees. Several dykes cut through the slate, whilst quartz veins run in all directions. The dykes run very nearly in the line of strike, and at first sight appear bedded and not intrusive. That the quartz veins originated subsequent to the dykes is seen by their penetrating the latter. Interbedded with the slates are thick sheets of volcanic ash much resembling quartzites. The slates of St. Maughold's Head have yielded Palæochorda and certain oval structures which are evidently organic. In the neighbourhood of Ballure Glen and Ballastowel Hill, the slates are badly bedded, and full of irregular pebble-like inclusions, which give to the rock a brecciated appearance. These have yielded the cast of a trilobite much resembling Asaphus or Eglina, and also certain other structures which may possibly prove organic. North and north-west from Ballastowell, the Skiddaw slates consist of irregularly bedded iron-stained slates with interbedded volcanic ash, the latter often of considerable thickness. 6 Near Sully Glen Station occurs the singular and isolated hill of Cronk Lumark, made up of a shivery' slate. In a quarry on the north side of the hill specimens were discovered of Dictyonema sociale and of a new species not yet described. A series of dip observations taken along Sully Glen, Tholt-e-Will, and over the summit of Snaefell, shows that the dip changes round towards the west, causing axes of the anticlinal folds to emerge on the west coast, a little to the south of Peel, where the cliffs exhibit a series of contortions and folds not unlike those of Gob-ny-Garvain and Port Mooar. The conclusions deduced from these observations are as follows: (1) That the Skiddaw slates of the north of the Isle of Man dip north-northwest from an axis of folding which runs from Gob-ny-Garvain and Port Mooar on the east to a little south of Peel on the west. (2) That there exists a series of contemporaneous beds of volcanic ash. (3) That the Skiddaw slates are fossiliferous, and by their fossils show a relation with the Lingula Flags of the Cambrian. 9. On the Volcanic Phenomena of Japan. 10. On the Radiolarian Cherts of Cornwall. By HOWARD Fox, F.G.S. The Mullion Island radiolarian cherts were first recognised by Mr. J. J. H. Teall, F.R.S., in rocks sent to him by the author last autumn, and a joint paper was read at the Geological Society's meeting, February 8 last, describing the manner in which they occur. Dr. Hinde accompanied the paper with a description of the species recognised and with micro-photographs of the individual organisms. Last Easter Mr. Teall, Professor Lapworth, and the author traced these cherts for about 650 yards in the cliffs and on the foreshore from the south end of Nelly's Cove, near Porthallow, Meneage, to near Ligarath Point, south of the Nore Point. Subsequently the author has examined the coast and some inland districts between Helford River and Fowey, and has found other exposures in the following places: Pendoner Beach, Veryan (for about 1,000 yards).-Beds many feet thick at the west end of this beach, on which the raised beach rests. Angular fragments of |