of moraine running down towards Llyn Llydaw, but living rock soon makes its appearance in this in such a way as to show that if there is any old channel in this direction it must be exceedingly narrow and tortuous. Thus, if this lake is not contained in a true rock basin, it must be very shallow or else must have found exit by a gorge quite as narrow as those found at the end of some of the Swiss glaciers. Immense quantities of moraine material occur on the south-east side of Llyn Llydaw, but a careful examination of the map and the ground shows that only two possible outlets exist-that now used for this purpose, and a second which is occupied by bog resting on moraine, and gives rise to a small stream which is joined lower down by the outlet of Llyn Teyrn. The moraine is, however, only a thin skin on the surface of rock. The present outlet shows live rock forty or fifty feet below the level of the lake, and the second possible exit at a rather less distance below the same level. If the moraine were stripped off, there is little doubt that this lake, like Glaslyn, would show a basin of rock which would hold water, unless it is very much shallower than is generally supposed to be the case. 7. Interim Report on the High-level Shell-bearing Deposits of Clava, &c. 8. Interim Report on the Calf Hole Cave Exploration. 9. Report on the High-level Flint Drift of the Chalk. 10. Report on the Rate of Erosion of Sea Coasts. 11. Final Report on Underground Waters.-See Reports, p. 393. 12. On Modern Glacial Striæ. By PERCY F. KENDALL, F.G.S., and J. LOMAS, A.R.C.Sc. The authors have spent several weeks during the present summer among the glaciers of the Nicolaithal and the Val Tournanche, and have paid especial attention to the form and distribution of glacial striæ. The present communication deals with four principal sets of phenomena. 1. The Crossing of Two or more Sets of Striæ.-In the discussion of the glacial geology of Britain and other countries writers have ascribed the formation of two superposed sets of striæ on one surface either to the action of floating ice or to a different period of glaciation. The authors have found that the phenomenon is of quite general occurrence, especially on the steeply inclined weather'-sides of roches moutonnées. They have observed an angular divergence of 89°. 2. The Forms of Strice as a Means of determining the Direction of Icemovement. It is often impossible to decide à priori whether a particular scratch or set of scratches was produced by ice moving, say, from south to north, or from north to south. The late Professor Carvill Lewis thought that striæ having a broad and a narrow end would furnish reliable criteria, but the authors, after careful examination of a large number, are unable to regard such characters as possessing the required degree of constancy. 3. The Phenomena known to American Glacialists as 'Semilunar Markings,' 'Pluck-marks,' and Chattered Striæ.'-The authors found many examples of these features of glacial abrasion upon roches moutonnées. The 'pluck-marks' were found to be shallowest at their 'downstream' ends. Chattered striæ,' i.e., ragged striæ presenting somewhat the appearance of a succession of bruises, were very common. They were probably produced by boulders that were only partially embedded in the ice, and were thus dragged along with a jerking motion. It is satisfactory that these minor details of the glacial phenomena of the United States can be paralleled in the Alps. 4. The Occurrence of 'Screwed' or Curved Striæ.-Authors have ascribed the formation of sharply curved or screwed striae to the swinging of floating ice when partly aground. The present writers have observed and recorded by heel-ball rubbings' and by photography many examples occurring on the roches moutonnées of the Gorner Glacier. 13. Notes on the Ancient Physiography of South Essex. The author refers to his paper, read before the Geological Society last year, entitled, Further Notes on some Sections on the New Railway from Romford to Upminster, and on the Relations of the Thames Valley Beds to the Boulder Clay.' İn that paper he mentioned the discovery, in a railway cutting at Romford, of part of an ancient silted-up stream course of considerable size, covered by gravel belonging to the highest, and presumably oldest, terrace of the Thames Valley system. In this communication he considers more fully the evidence bearing upon his view that the course taken by this ancient stream was between the high ground of Warley, Billericay, and Maldon, and that of Laindon, Rayleigh, and Althorne into the Blackwater, the basins of the Mardyke and Crouch having originated at a much later period. He also notes evidence tending to confirm Mr. Whitaker's view that the gravel and loam at and near Canewdon, Southminster, and Bradwell were deposited on the western flank of the old Thames Valley when there was a considerable breadth of land east of those places, which has been since removed by marine denudation. SATURDAY, SEPTEMBER 14. The following Papers and Report were read: 1. Restorations of some European Dinosaurs, with Suggestions as to their Place among the Reptilia. By Professor O. C. MARSH. For several years I have been engaged in investigating the Dinosaurs of North America, where these extinct reptiles were very abundant during the whole of Mesozoic time. The results of my study have been published from time to time, and I have already had the honour of presenting some of these to the British Association. In carrying out this investigation so as to include the whole group of Dinosaurs, wherever found, and bringing all under one system of classification, it has been necessary for me to study the remains discovered in Europe, and Í have made several visits to this country for that purpose. In comparing the forms known from the two continents, certain important differences as well as some marked resemblances between the two have been observed and placed on record. In concluding my investigations of the North American forms, I have fortunately been able to make restorations of the skeletons of quite a number of very complete type specimens, and this has proved a most instructive means of comparing those from different horizons, and of different groups, among the known Dinosauria of America. The success of this plan rendered it very desirable to extend it, if possible, to the best-known forms of European Dinosaurs. This I have been enabled to do in a few instances, and the main object of the present paper is to lay these latest results before you. RESTORATIONS OF EUROPEAN DINOSAURS. The restorations of Dinosaurs which I have to present are four in number, and represent some of the best-known European forms, types of the genera Compsognathus, Scelidosaurus, Hypsilophodon, and Iguanodon. These outline restorations have been prepared by me mainly for comparison with the corresponding American forms, but in part to insure, so far as the present opportunity will allow, a more comprehensive review of the whole group. The specimens restored are all of great interest in themselves, and of special importance when compared with their nearest American allies. Compsognathus. The first restoration, that of Compsognathus longipes, Wagner, 1861, shown natural size in the diagram, is believed to represent fairly well the general form and natural position, when alive, of this diminutive carnivorous Dinosaur, that lived during the Jurassic period. The basis for this restoration is (1) a careful study of the type specimen itself, made by me in Munich in 1881; (2) an accurate cast of this specimen, sent to me by Prof. von Zittel; and (3) a careful drawing of the original made by Krapf in 1887. The original description and figure of Wagner (Bavarian Academy of Sciences, 1861) and those of later authors have also been used for some of the details. No restoration of the skeleton of this unique Dinosaur has hitherto been attempted.1 Compsognathus has been studied by so many anatomists of repute since its discovery that any attempt to restore the skeleton to a natural position will be scrutinised from various points of view. My interest in this unique specimen led me long ago to examine it with care, and I have since made a minute study of it, as related elsewhere, not merely to ascertain all I could about its anatomy, but also to learn, if possible, what its relations were to another diminutive form, Hallopus, from a lower horizon in America, which has been asserted to be a near ally. Both are carnivorous Dinosaurs, probably, but certainly on quite different lines of descent. The only previous attempt to restore this remarkable Dinosaur was by Huxley, when in America in 1876. He made a rapid sketch from the Wagner figure, and I had this enlarged for his New York lecture. This sketch, reproduced on the diagram exhibited, represents the animal sitting down, a position which such Dinosaurs occasionally assumed, as shown by the footprints in the Connecticut Valley, which Huxley examined in place at several localities with great interest. The great majority of Dinosaurian footprints preserved were evidently made during ordinary locomotion, although some series show evidence of more rapid movement. All those referred to carnivorous Dinosaurs are bipedal, and this is true of the footprints of many herbivorous forms. In the present restoration of Compsognathus, I have tried to represent the animal as walking, in a characteristic lifelike position. The remains of the embryo within the skeleton of Compsognathus, first detected by me in 1881, while examining the type specimen, are not represented in the present restoration. This unique fossil affords the only known evidence that Dinosaurs were viviparous. Scelidosaurus. The second of these restorations is that of Scelidosaurus Harrisonii, of Owen, shown natural size in the diagram. This reptile was an herbivorous Dinosaur of moderate size, related to Stegosaurus, and was its predecessor from a lower geological horizon in England. This restoration is essentially based upon the original description and figures of Owen (Palæontographical Society, 1861). These have been supplemented by my own notes and sketches, made during examinations of the type specimen, now in the British Museum. Scelidosaurus is a near relative, as it were, of one of our American forms, Stegosaurus, now represented by so many specimens that we know the skull, skeleton, and dermal armour, with much certainty. The English form known as Omosaurus is still more nearly allied to Stegosaurus, perhaps identical. A restoration of the skeleton of Scelidosaurus, by Dr. Henry Woodward, will be found in the British Museum Guide to Geology and Palæontology, 1890, p. 19. The missing parts are restored from Iguanodon, and the animal is represented as bipedal, as in that genus. In the present outline restoration of Scelidosaurus, I have endeavoured merely to place on record my idea of the form and position of the skeleton, when the animal was alive, based on the remains I have myself examined. In case of doubt, as, for example, in regard to the front of the skull, which is wanting in the type specimen, I have used a dotted outline, based on the nearest allied form. Of the dermal armour, only the row of plates best known is indicated. The position chosen in this figure is one that would be assumed by the animal in walking on all four feet, and this I believe to have been its natural mode of progression. Hypsilophodon. The third of these restorations, that of Hypsilophodon Foxii, Huxley, 1870, given in outline, natural size, in the diagram, has been made with much care, partly from the type specimen, and in part from other material mostly now in the British Museum. The figures and description by the late Mr. Hulke1 were of special value, although my own conclusions as to the natural position of the animal when alive do not coincide with those of my honoured friend, who did so much to make this genus of Dinosaurs, and others, known to science. The restoration by Mr. Hulke is shown in another diagram. In the case of Hypsilophodon, a number of specimens are available instead of only one. This makes the problem of restoration in itself a simpler matter than in Scelidosaurus. Moreover, we have in America a closely allied form, Laosaurus, of which several species are known. A study of the genus Laosaurus, and the restoration of one species given on the diagram exhibited will clear up several points long in doubt. Huxley and Hulke both shed much light on this interesting genus, Hypsilophodon, indeed, on many of the Dinosauria. The mystery of the Dinosaurian pelvis, which baffled Cuvier, Mantell, and Owen, was mainly solved by them, the ilium and ischium by Huxley, and the pubis by Hulke. The more perfect American specimens have demonstrated the correctness of nearly all their conclusions. Iguanodon. The fourth restoration exhibited, that of Iguanodon Bernissartensis, Boulenger, 1881, one-fifth natural size, has been made in outline for comparison with American forms. It is based mainly on photographs of the well-known Belgian specimens, the originals of which I have studied with considerable care during several visits to Brussels. The descriptions and figures of Dollo have also been used in the preparation of this restoration. A few changes only have been introduced, based mainly upon a study of the original specimens. 1 Philosophical Transactions, 1882. 2 2 Bulletin Royal Museum of Belgium, 1882-88. Beside the four genera here represented, no other European Dinosaurs at present known are sufficiently well preserved to admit of accurate restorations of the skeleton. This is true, moreover, of the Dinosaurian remains from other parts of the world outside of North America. To present a comprehensive view of the Dinosaurs, so far as now known, I have prepared the plate exhibited, which gives restorations of the twelve best-known types, as I have thus far been able to reconstruct them. Of these twelve forms, eight are from America: Anchisaurus, a small carnivorous type from the Trias; Brontosaurus, Camptosaurus, Laosaurus, and Stegosaurus, all herbivorous, and the carnivorous Ceratosaurus, from the Jurassic; with Claosaurus and Triceratops, herbivores from the Cretaceous. These American forms, with the four from Europe already shown to you, complete the series represented on the chart exhibited. They form an instructive group of the remarkable reptiles known as Dinosauria. The geological positions of Compsognathus and of Scelidosaurus are fully determined, but that of Hypsilophodon and Iguanodon is not so clear. The latter are found in the so-called Wealden, but just what the Wealden is I have not been able to determine from the authorities I have consulted. The Cretaceous age of these deposits appears to be taken for granted here, but the evidence as it now stands seems to me to point rather to the upper Jurassic as their true position. If I should find the vertebrate fossils now known from your Wealden in the Rocky Mountains, where I have collected many corresponding forms, I should certainly call them Jurassic, and have good reason for so doing. Moreover, after visiting typical Wealden localities here and on the Continent, I can still see no reason for doing otherwise so far as the vertebrate fossils are concerned, and in such freshwater deposits their evidence should be conclusive. I have already called attention to this question of the age of the Wealden, and do so again, as I believe it worthy of a careful reconsideration by English geologists. 2. Report on the Investigation of the Locality where the Cetiosaurus Remains in the Oxford Museum were found. See Reports, p. 403. 3. Preliminary Notice of an Exposure of Rhætic Beds, near East Leake, Nottinghamshire. By MONTAGU BROWNE, F.G.S., F.Z.S. (Fourth Contribution to Rhatic Geology.) On the confines of Leicestershire and Nottinghamshire, near East Leake in he latter county, the extension of the Manchester, Sheffield, and Lincolnshire Railway has lately exposed an interesting section by the tunnel, which cuts through the White Hills, under the high road, and is bounded on the west by the coppice called the Devil's Garden,' which is near the end of a westerly extension or promontory of the Liassic with Rhætic beds. The ordinary appearance of Midland exposures is here exhibited, and many of the beds are homotaxial, both by lithology and contained fossils, with those of exposures so remote as Wigston in Leicestershire, Westbury-on-Severn, Pylle Hill at Bristol, and Watchet in Somersetshire. As in these exposures, there is no actual or massive bone-bed as at Aust, &c., although, most curiously, one pieceand one only, identical with the Aust breccia--was picked up at the tip.' The usual minerals are present in the shales and stone, viz., selenite, iron pyrites, oxides and peroxides of iron, and galena sparingly. The fossils are interesting, not only as supplementing those previously alluded to by the writer in former contributions, but as exhibiting some rare forms not previously recorded for Britain, as given in the following list: 1 This ancient and singular appellation is suggested by the writer as probably due to the exposure of the black shales here in digging, the surroundings being a wide area of Keuper red marls. 2 British Association Reports, 1891–2–4. |