Below the 300-feet level there occurs a belt or interval 150 feet broad, over which "shell-banks" are not met with, below which a second series occurs. The shells contained in these beds differ from those of the higher series in being less arctic. Certain of these characteristic forms have disappeared, numerous boreal shells have made their appearance, together with forms of the Lusitanian region. Altogether this marine fauna approximates to that of the neighbouring seas, only that some members of the earlier or more arctic series linger on. The subdivision of the East-Anglian Kainozoic series is as follows:- A. PREGLACIAL. Crag, in Suffolk, is a local agricultural name for any sandy, gravelly soil; but the early geologists and shell-collectors soon found that it was something more; its very perfect shells were recognized as in part agreeing with those of the neighbouring seas, in part as unknown or foreign. Mr. S. Woodward, in his 'Outline of the Geology of Norfolk,' 1833, has a detailed account of this formation. His own views are admirable; the range of the Crag formation, as he gives it, from Cromer, by Norwich, to the Suffolk coast is nearly exact. Nor did the estuarian character of the formation about Norwich escape him. Apart from this local condition, he considered the Norfolk and Suffolk beds to be " decidedly contemporaneous." It was not till 1835 that a subdivision of the Crag was proposed by Mr. Charlesworth; and it was amended (in 1838) by the following classification:4. Upper Crag of Norfolk and Suffolk 5. Red Crag. 6. Coralline Crag. Thus far back Mr. Charlesworth separated the Norwich Crag from that of Suffolk. The Red Crag at Tattingstone, Ramsholt, and Sudbourne was said to overlie a worn and uneven surface of the white or coralline; from this consideration their relative dates or ages was inferred. This nominal subdivision may be said to have been adopted from that time onwards down nearly to the present. The Bryozoan Crag overlies London clay, and is under 20 feet thick. It is a good division, because it is an indication of a definite range of depths, where the sea-bed was not within reach of surface disturbance, yet where the drifting power was considerable, and having its own proper fauna, of which the Bryozoa form a very large proportion. The examples of this condition of sea-bed occur only in Suffolk, where they are now about 40 feet above the sea-level. Assigning to these beds depths of 40 fathoms, a difference of 300 feet is the least that can be assumed as that of their original, compared with their present positions. It is the lowest condition, or the deepest, of which our English area offers any illustration. It does not occur over any part of Belgium, where the lowest beds above the sea-level belong to the deep-sea deposits of ooze, or to the 100 fathoms depth. The Red Crag, though a good division for the time when it was proposed, is a complex assemblage, in spite of its small vertical dimensions. Of all that was originally so grouped, a very small portion only (that of one locality) can now be referred to as such, namely, the Crag at Walton Naze; in this alone is to be found an old sea-bed, a marine-life zone, undisturbed since its original accumulation. The Red-Crag beds of the valleys of the Stour, Orwell, and Deben, though referable to some part of the same general period, are wholly rearranged or remanié beds and of the later stages of the Crag-sea; they are, relatively to the Walton beds, very shallow-water accumulations, presenting that diagonal mode of accumulation in varying directions indicative of surface disturbance and tidal movements. Above them, in places, and on the land side of them, are certain thick accumulations of red coarse sands, which have also been referred to the Red Crag, and which at one time I supposed to represent a more marginal sea-zone, the ordinary Red Crag being that condition of sea-bed known as dead-shell sand and gravel. The shell-gravel of Antwerp corresponds with the Red Crag of Suffolk. Additions were subsequently made, as in the case of the Chillesford Crag of Prestwich, and the Bridlington Crag. The Norwich, or fluvio-marine Crag, the uppermost of Mr. Charlesworth's classification, was for many years the subject of differences of opinion, as to its value and distinctness as a division; it had also gradually been made to include much more than at first: any bed containing either mammalian and molluscan remains, or even an admixture of fresh- and salt-water mollusca, in any part of Suffolk and Norfolk, had come to be put down as the equivalent of the Norwich Crag. General opinion seems now to have come round to the view which some geologists had long since taken. Writing in 1865, Mr. Searles Wood states, "the Norwich Crag is not geologically distinct from the Red, but a fluvio-marine condition of the same period." He establishes this in an analysis of the molluscous fauna, such as leaves little doubt as to this point; and the only criticism which is suggested is-may it not have been an equivalent of the whole Crag period? and may not the Yar valley have been a tributary to the Crag Sea, during its whole duration as such? In Suffolk, the fluvio-marine accumulations at Thorpe, near Aldborough, Wangford, and Bulcham, are considered by Mr. S. Wood to be of the same age as that of Norwich. The Forest-bed of Cromer (1824), and some other places, to which Mr. R. C. Taylor first called attention, and to which he assigned its true age and position, is one of the most interesting points in Norfolk geology; it is the unmistakeable indication of a terrestrial surface, antecedent to the period of the "glacial-drift" accumulations. This old land-surface, at Cromer, is exposed at the sea-level; but it extends inland, and has been met with at considerable depths in the offing. The arboreal vegetation buried in these beds comprises the Norway spruce, Scotch fir, yew, oak, alder,-all of them common North-European trees. What the Cromer coast-section demonstrates is, that by process of change of level a forestial condition of the surface had been brought down to the seamargin, that the trees had died, and that mud-deposits had formed, partly under fresh, partly under brackish water lagoons. Subjacent to the "Forest-bed," and covering the surface of the Chalk, is a layer of chalk flints; a like accumulation is seen resting on the Chalk in numerous other places, as in the sections below this city (Holy Cross, Thorpe, &c.), and are all referable to the same agency and period. The flints have been dissolved out of the chalk by the action of rain-water, and left in situ; they indicate a long period of subaërial conditions; and their formation is coextensive with the whole duration of those conditions; they are therefore of the same period as the "Forest-bed." All collectors and observers seem now to be agreed upon this, that the Cromer mammalian remains are referable to this particular surface. B. GLACIAL. More recently the Norwich sections have been subjected to a closer examination; and according to Mr. J. E. Taylor (1867) these admit of a twofold division: the upper is a coarse and rubbly accumulation, with well-rounded pebbles of flint; the lower consists of finer sands. A band of white cross-bedded sand interSuch a change in the character of successive beds would not, by itself, have been of much importance; but zoologically the differences they present are much more significant. venes. The fresh- and brackish-water forms, which long since gave the Norwich Crag its fluvio-marine character, occur only in the lower division; in this, too, the proportion of littoral species of marine shells is greater; and here also are found all those forms which are supposed to be extinct. The upper division has its peculiar forms, such as Modiola modiolus, Astarte compressa, A. sulcata, A. elliptica. Other shells are more abundant which in the lower are scarce; here they occur as if in their "life-zone," instead of as single valves, worn and broken--such as Tellina obliqua, Astarte borealis, Venus fasciata, Cardium Grænlandicum, Cyprina Islandica, Rhynchonella psittacea. It is only in respect of one shell (Tellina obliqua) that the forms of the upper division have not been recognized as living; and with respect to distribution, the northern facies of the upper assemblage is more strongly marked than that of the lower lastly, they indicate a somewhat greater depth of water. Mr. S. Wood, jun., admits this division; "the upper bed at Norwich," he says, "is the Chillesford shell-bed." Chillesford Crag.-In 1849, Mr. Prestwich made known some marine beds in the parishes of Iken and Chillesford, either yellow sands or laminated micaceous clays. At Iken these beds are superposed upon a worn surface of the older or Bryozoan Crag. There is no such direct evidence as to their relation to the Red Crag; but there is no doubt that they are unconformable to both divisions. These beds are in striking contrast to the true Crag, in respect of their composition and the condition of the shells they contain; they were tranquil depositions, the bivalves at every place constantly exhibiting the two shells in contact, and in the positions in which the animals had lived. With respect to this fauna, 23 species only were met with-4 Gasteropods and 19 Acephala. Mr. S. Wood recognized the Arctic character of the assemblage, and considered the beds posterior to the Red Crag, probably the equivalents of the Norwich. The agreement with the Bridlington Crag was not very close, there being only six or seven species in common. Differences of opinion as to detail, both of facts and inferences, might be cited, as is well-known to those geologists who have attended to this very complicated portion of the geological record; but thus much seems to have been ascertained, that the so-called Chillesford Crag is rather a subordinate member of the marine glacial period than an upper member of the Crag, and that it is referable to a time when the climatal conditions, as indicated by the marine mollusca, had undergone a great change. Bridlington Crag was a name given to a set of marine clay-beds occurring at that place, about 30 feet thick; they overlie an accumulation of chalk flints derived from the subjacent chalk. Mr. S. Wood, in his Monograph, included these beds in the Crag, and considered them the equivalents of the Norwich Crag (1855). I am not aware that the fauna of these beds attracted any particular attention till Mr. S. P. Woodward prepared his general list of the Norwich-Crag accumulations for Mr. Gunn's essay. In 1864 he undertook a fresh examination, not from lists, as before, but from original specimens from Mr. Bean's and Mr. Leckenby's collections; this led him to the unexpected result that the Bridlington Crag could no longer be considered an equivalent of the Norwich Crag. The list of marine testacea had been increased to 64 (or by more than 20); of these, 35 are met with in the Norwich Crag, whilst 29 species (or one-half) are now living in seas north of Britain, the proportion of Arctic shells in the Norwich Crag being only one-sixth. Mr. Woodward next compared the Bridlington fauna with that of the Clyde beds belonging to the close of the "glacial period," and with this result, that they differed very nearly as much from these as they did from the Norwich assemblage; they must therefore be separated from the Crag series. The Bridlington testacea are more indicative of Arctic climatal conditions than any assemblage in or about the British Islands. As an assemblage, it is wholly recent and living, and marks a stage in the northern submergence during the glacial period, when the Arctic-basin marine fauna had extended itself over our The Bridlington beds seem to correspond most nearly in age with those which, in Norway, M. Sars has distinguished as his glacial formation. Mr. Trimmer candidly admits that, when engaged in the "Geology of Norfolk" for the Royal Agricultural Society (1847), it was the adoption of a theory guiding his observations that enabled him to disentangle and harmonize all that mass of confused materials (Drift) which till then had so perplexed him; "each part then soon fell into its appropriate place." In this case, fortunately, the adopted theory was right, namely, submergence and emergence-that the accumulations of the erratic group indicate a long period of accumulation over a terrestrial surface, followed by denudation as it rose again. For the whole of the period and its products, he proposed two groups of Drift-a lower and an upper. He seems to me to have recognized certain distinctive characters in the Lower Drift, which are the indications of the different conditions of accumulation concerned, such as "the masses of fragmentary chalk, with little or no admixture of other matter," "angular fragments, very slightly water-worn," and, on the other hand, the "detritus from greater distances;" the transfer of this chalk material in the direction of Cromer had not escaped him. Mr. Searles Wood, jun., had proposed for the "Drift or Glacial" series of the upper Kainozoic period an upper and a lower; he subsequently subdivided the lower, whence resulted : feet. 1. Upper Drift, or Boulder-clay, maximum thickness.... 160+ 3. Lower Drift (boulder, till, and contorted beds of Cromer) 150+ The Lower Drift immediately overlies the Chalk, except near this place, where it has what has been designated as the "Norwich Crag" at its base, the inland facies of this division being a mass of merely remanié chalk rubble, without any admixture of other materials; this facies does not extend east of Norwich. Beyond and on to the coast the Lower Drift is of sand; above, on the coast section, is a blue till with boulders, horizontally bedded, passing up into very contorted beds. These lower sands west of Cromer contain the débris of the underlying Lignite beds. In the case of the inland, as of the coast-line facies, the character of the accumulation is immediately dependent on the subjacent beds. When we bear in mind that previously to the accumulation of this Drift-series the boundary line of the Nummulitic. formation by Sudbury and Ipswich had been well defined, and consequently that High Suffolk and Norfolk presented a range of bare chalk hills, we are prepared to adopt the supposition of Mr. S. Wood, jun., and refer this division of the series to the agencies of subaerial glaciation. C. POSTGLACIAL. In the Nar valley, which joins the Ouse at Lynn, is met with a well-known set of marine depositions of this age. They extend some nine miles along its course, and occupied what must have been a creek at the time when the whole of the Bedford level was sea-an inland extension of the Wash. Mr. Rose called attention to this stage of the Kainozoic series in 1836, and assigned it to its true position. This deposit, which is 40 feet in thickness and 60 above the present sea-level, contains 27 species of testacea, all of which are also North-Sea shells. These subjects have engaged many speculative and ingenious minds, from the middle of the last century, down to those now actively at work here-such as Arderen, William Smith the father of Geology, the Taylors, Robberds, the Woodwards (of whom four generations), Clarke, Mitchell, Trimmer, Gunn, Osmond Fisher. But I should be wanting to the place in which we are now met, wholly unworthy to fill this chair, wanting to the great subject which assembles so many here, wholly forgetful of my own obligations, if I were not mindful that Norwich may claim with Cambridge joint ownership in the Woodwardian Professor-the Rev. Canon Sedgwick. Notes on the Fossils from the Old Red Sandstone of Kiltorcan Hill, County Kilkenny. By WM. HELLIER BAILY, F.L.S., F.G.S., &c. With reference to the plant-remains, Dr. W. P. Schimper has communicated to me some important information. He remarks that the fructified leaves of Cyclo pteris Hibernica show that this fossil fern belongs to the family of Hymenophyllæ, forming a peculiar genus, to which he gives the name of Eopteris. The species of Sagenaria he names S. Bailyana. In the fruit of this species, which differs from S. Veltheimiana, the scales are extremely long, and nearly subulated. On some specimens very large and distinct sporules were arranged at the bases of the scales; this he considered very remarkable, as no other species, of which the fruit is known, have such large sporules, a proof, as he remarks, of inferiority of the plant, probably the oldest of the genus. In the last collection of fossils made at this place by myself and the fossil-collectors of the Geological Survey, parts of a crustacean, including the chele or pincers, were obtained, presenting clear evidence of the existence of Pterygotus amongst this assemblage. This species I propose to name P. Hibernicus. The discovery of these characteristic portions of a genus, which appears to have preceded Eurypterus, is of considerable importance, both stratigraphically and as serving to explain the more exact relationship of specimens formerly obtained from this place, and doubtfully referred to the latter genus, but which will, I believe, be found to be identical with P. Hibernicus. The fish-remains hitherto discovered are, for the most part, in the condition of detached bones and plates or scales, and are therefore necessarily difficult of determination. Glyptolepis and Coccosteus are the prevailing forms; there are others, however, which require study and additional specimens for their elucidation. It is hoped therefore that further explorations at this important fossil locality will throw considerable light upon the fossils of the Old Red Sandstone. On the Molluscan Fauna of the Red Crag. By Alfred Bell. The results of a critical comparison of the shells of the different crags are considered by the author to justify him in the following conclusions: That the series of deposits constituting the Red Crag proper commences at Walton-on-the-Naze, and does not extend further north than Chillesford, where it appears as the base-bed of the pit under the church. That the molluscan fauna contained in this area lived in the Red Crag seas, and are not derived from the débris of an older formation (except in a very few cases). That the beds containing these shells were deposited in quiet waters, and That the proportion of recent forms is about 65 per cent. (exclusive of land and freshwater shells). In support of these propositions it is shown that the lowest Red Crag deposits, i. e. those at Waldringfield and Walton-on-the-Naze, while the nearest in their relations to the preceding formation, containing such characteristic Coralline Crag shells as Gastroma laminosa, Artemis lincta, Cardium decorticatum, Voluta Lamberti, Fusus consocialis and alveolatus, Terebra inversa, Eulima polita, Cerithium inversum, Pyramidella læviuscula, and others, are marked by the introduction of at least fifty new forms. Of the 400 species found in the Coralline, not more than about half range upwards to the Red Crag, and the greatest diversity in their respective faunæ obtains where, as at Ramsholt and Sutton, the two formations are seen in juxtaposition. The small solid Pyramidella may serve for an example. Abundant in the White Crag at Sutton, it is altogether absent in the Red Crag at the same place. The following short list will suffice to show the difference in the characteristic shells in the older and newer Red Crags, most of the abundant forms of the lower beds (Coralline Crag and earlier Red) being altogether absent, or but sparely represented in the upper horizon, and also the reverse. Older Red Crag of Walton and Waldringfield. Coralline Crag shells as already quoted: Artemis exoleta, Mactra glauca, Tellina Benedeni, Cardium Parkinsonii, Nucula laevigata, Cypræa angliæ, Nassa elegans and reticosa, Purpura tetragona, Buccinum Dalei, Cancellaria coronata, Acteon (var.) noæ, &c. Newer Red Crag of Butley and Ramsholt. Pecten gracilis, Mytilus edulis, Nucula Cobboldiæ, Yoldia myalis, Cardium græn |