THE VIGRA SECTION.

The Vigra Copper Mine is situate to the west of Clogau, and takes up nearly the whole of the Vigra Mountain. Extensive explorations have been carried on here for copper, some of which is auriferous. The lode-stuff, taken at random, yields nearly half an ounce of gold to the ton, on assay. Specimens have produced more than this. Visible gold is said to have been found here. This mine ought to be worked on a large scale for gold. The Clogau Gold Mill is erected on this property. Tyddyndu Mine, or as it is called "Victoria," lies between the Vigra and Clogau Mines, to the south of Maesclawdd, and extends under the turnpike-road at Pontddu to the river Mawddach. There are several lodes on this property, all of which are auriferous. At present they are poor at surface.

North Vigra Mine has several lodes, said to be gold-bearing.

The Wellington Mines have some very large quartzose lodes in them, which are undoubtedly auriferous.

Fach-ynys Mine.-The lodes here have yielded 6 dwts. of gold to the ton at the surface. This mine promises to be rich.

Nant-Coch Mine has given by assay, and, singularly enough, by Britten's Machine, 9 dwts. 13 grs. of gold to the ton of mineral.

Llanaber Mine, near Barmouth, is also auriferous at surface.

The known gold localities are now multiplied; and the author added, that he should not be at all surprised if every quartzose vein of the district is found to be auriferous, but that it must by no means be inferred from this that every quartzlode will pay for working some will not; but where there are so many, some certainly will prove rich.

Having said thus much upon the increased number of places in which gold is found in this district, the author made some reference to the modes of gold-extraction now in operation.

Notice of some Mammalian Remains from the Bed of the German Ocean.

By C. B. ROSE, F.G.S., &c.

It has for a very long period been known that, during the degradation of the cliffs of the counties of Norfolk, Suffolk, and Essex, teeth and bones of various mammals have been exhumed, and, more largely, those of Pachyderms. In Queen Elizabeth's time, huge bones were found at Walton, near Harwich. They were then considered to be those of giants. In the Philosophical Transactions' for 1745, a Mr. Baker records the finding of a fossil elephant at Mundesley Cliff; and, in 1746, Mr. Wm. Arderson, of Norwich, makes mention of similar remains discovered at Hasborough and Walket, on the Norfolk coast.

In the course of years, vast numbers of teeth and bones have been collected. The late Mr. Woodward, of Norwich, says, in his 'Geology of Norfolk,' "Mammalian remains have been dredged up on the Knole Sand off Hasborough. This spot presented us, in 1826, with the finest tusk of the Mammoth; it measured 9 feet along its curvature, and weighed 97 lbs." But off Dungeness a tusk was dredged up which measured 11 feet in length, and yielded some pieces of ivory fit for mauufacture. The oyster-bed off Hasborough was discovered in 1820, and, from the number of grinders of the Elephant found there, Mr. Woodward felt himself warranted in concluding that upwards of 500 animals were deposited in that limited space.

The coloured map of the German Ocean exhibited at the Meeting showed the localities whence the organic remains are chiefly taken. Certain spots marked thereon are the fishing-grounds, and, therefore, the depositories of the fossils with which we are made familiar; but we cannot doubt that these exuviæ are more generally distributed over the sea-bottom. The following specimens were exhibited:-Teeth of three species of Elephant, Elephas primigenius, E. antiquus, and E. meridionalis; cervical and dorsal vertebræ of the same genus; two teeth of a Hippopotamus (a dorsal vertebra has since been brought up); a dorsal vertebra of a Whale; a unique specimen of a lower jaw of the Trichechus rosmarus; heads of the Megaceros Hibernicus, male and female; an anterior dorsal vertebra of ditto (an antler, 4 feet 6 inches long, has since been brought me); atlas of ditto; a frag

ment of an antler of Cervus tarandus; the humerus of a gigantic Ox; a portion of the head of the Equus fossilis; and a fine specimen of Castor Europaus-the head. The colour of these specimens might lead us to believe that they belonged to the Mammaliferous Crag period; but colour is not a decisive criterion. It is probable that they may have lain in close proximity to a bed of crag*; they are unquestionably from a Pleistocene deposit.

And now as to how these organic remains came to be at the bottom of the ocean. At a not very remote geological period our island was united with the Continent; a catastrophe took place which separated them and led to the formation of the German Ocean. This gap has been continually enlarging, from the crumbling down of the cliffs on either side; the fossils have thus been exhumed, carried out to sea during storms by retiring waves, and there deposited. No doubt, also, many remains which lie buried in the land that originally united us to the Continent sank bodily with it; and consequently they are met with when the sea-bottom is raked over by the trawling-nets of the fishermen.

The measurements of three tusks are given. One, belonging to Mr. Owles, measures: length of external curve 7 feet 5 inches; girth at proximal end 18 inches; radius of inner curve 3 feet.

The author possesses two perfect tusks: one, length 6 feet 3 inches; girth 17 inches; radius of curve 3 feet 3 inches: the other, length 6 feet; girth 12 inches; radius of curve 4 feet 2 inches. These proportions indicate that his specimens are from two distinct species of Elephant.

A femur of the Mammoth in his possession measures 3 feet 5 inches, minus the head of the bone.

On the Identity of the Upper Old Red Sandstone with the Uppermost Devonian (the Marwood Beds of Murchison and Sedgwick), and of the Middle and Lower Old Red with the Middle and Lower Devonian. By J. W. SALTER, F.G.S.

The sections of the Old Red Sandstone and Mountain Limestone on the Pembrokeshire coast are unrivalled for their extent and completeness. The vertical beds, exposed to the coast-waves, are worn by them in such a manner as to clear them of all detritus, and exhibit the succession of Old Red conglomerates, Carboniferous shales, and Mountain Limestone in several small sandy inlets accessible at all tides, especially at the most important points, viz. the junction of the Old Red with the superjacent shales.

Three of these sections have been measured in detail by Sir H. De la Beche and the corps of the Geological Survey, and are given in vol. i. of their Memoirs, pp. 61, 100, 130.

At Caldy Island, the Upper Old Red marls and sandstones, ending in yellow conglomerate-beds, are covered by 400 feet of shales and limestones in an alternating series, among which beds of oolite were found to be of common occurrence, filled, down to the very base, by common Carboniferous species,-a thin band (at the base only) exhibiting, on the west side of the island, a bed of undescribed bivalve shells, all, however, allied to Carboniferous forms. And a new fact was established during this survey, viz. the presence of a band of marine Serpulæ 40 feet down in the Old Red.

The same section, bed for bed, with the characteristic thin oolite bands, and beds of shale crowded with the Rhynchonella pleurodon, occurs on the opposite coast of Skrinkle Bay, another of the sections measured by Sir Henry and his assistant Mr. Ramsay.

About twenty miles to the westward, the small bay of West Angle opens at the mouth of Milford Haven; and here a sharp, faulted synclinal in the middle of the bay permits the whole section to be seen twice in the promontories and reefs on either side of the bay. The series of beds have changed considerably from that seen on the opposite coast, and nearly 150 feet more shales are added to the upper part. In these shales a very perfect cleavage is established, fully justifying the *The atlas of the Megaceros has a Turritella incrassata (Crag fossil) sticking in the canal for the vertebral artery.

term "Carboniferous slate" applied to this formation in Ireland by Sir R. Griffith. It is the lower limestone shale of Dr. Smith, as seen at Bristol and the Mendips. In this section, too, new bivalves occur in the basement-beds as at Caldy Island.

Sundry other changes are observable when this section is compared with that on the east coast. The yellow conglomerate has disappeared; and while red and grey conglomerate-beds are still plentiful on the north side of the bay, on the south side (a distance of barely a mile) scarcely a band of conglomerate can be traced in the first 80 or 90 feet, only 25 feet of which is of a red colour at all; the remainder consists of grey shale, yellow sandstone, and bands of limestone, which have only the faintest representatives on the north side. Grey shales, with plants, are mixed with these on both sides.

The limestones are nodular, and contain crowds of Avicula Damnoniensis, Sow.: the characteristic shell of the Uppermost Devonian beds north of Barnstaple, North Devon (Rhynchonella laticosta, Phill.), occurs with it, together with species of Nucula, Axinus, Modiola, and Bellerophon, all of which are closely like, if not identical with, Barnstaple species. The Serpula-band before mentioned, at Caldy Island, occurs among these limestones, and at a somewhat greater distance below the base of the Carboniferous shales.

By this remarkable change in the mineral character, accompanied by the introduction of a marine fauna, we are prepared for the still greater change in the Old Red sediments on crossing the Bristol Channel. The red tint is not, indeed, wholly lost between Ilfracombe and Barnstaple, but is confined to a narrow belt of rocks; and the Marwood beds, which are the equivalents of the uppermost red rocks of Pembrokeshire, are grey sandstones and olive shales, with calcareous bands, and with no red colour at all. They represent exactly the state of things (but on a much larger scale) above described on the south side of West Angle Bay.

The Marwood Sandstones form a conspicuous group, ranging along a line five miles north of Barnstaple, and traceable east and west. They are well exhibited in the quarries at Sloly, on the Ilfracombe Road, at Marwood, Braunton, &c., and they form the headland of Baggy Point, where the best section occurs.

In ascending order we have the

1. Red slates and sandstones of Morte Bay.

2. A band of pale, nearly white slate, with a few bivalves.

3. A thick series of greenish-grey grits, with bands of Cucullaa and Avicula Damnoniensis in abundance, and with much olive shale, in which a new Lingulu occurs plentifully. (Marwood beds.)

4. An alternating series of calcareous sandstones, grey shales with thin nodular bands of limestone, and grey cleaved slate, full of fossils, and many hundred feet thick; Avicula Damnoniensis, Rhynchonella laticosta, &c., in all the lower part, and Strophalosia caperata and Spirifer Barumensis throughout. (Pilton Group.)

This series (No. 4) is the upper part of the Pilton group of Professor Phillips, and its aspect in the grand coast-section is exactly that assumed by the Carboniferous shales which lie upon beds much resembling No. 3 (and with the same fossils) in the West Angle section. The author had previously suggested this explanation (see Address of Pres. Geol. Soc. 1855, p. xlviii). A more minute comparison of the two series convinced him that this identification (strongly advocated by Sir H. De la Beche) was erroneous, and that the Pilton group really represents a new series, including in an altered form the uppermost beds of the Old Red Sandstone*, together with certain beds at the very base of the Carboniferous shales. But in the main it is a new series, deposited in deepening water, while the Upper Old Red area was stationary (or nearly so) and close to shore, as evidenced by its plants. This series of beds has been described from the South of Ireland, by Professor Jukes and the author, under the term Coomhola Grits. It occupies there the same relative position, overlying the true Old Red beds, and underlying the mass of the Carboniferous slate.

Some of its fossils are Carboniferous species; but most of them, though strikingly similar, are not identical, and the presence of a common Devonian Trilobite throughout confirms the propriety of their first reference by Murchison and Sedgwick to the

*Siluria, 2nd edit. p. 300.

top of the Devonian system. The Boulogne beds chiefly belong to this series, as does the "Spirifer-Verneuili-schiefer" of the Prussian geologists.

It is overlain, along the course of the Barnstaple River, by the representative of the Carboniferous slate, and this again by the Mountain-limestone series in a greatly altered form.

The Marwood and Pilton group, at least in part, can be thus proved by fossils to be the actual equivalent of the Upper Old Red Sandstone, a formation which has been found in some parts of the British Isles to be unconformable on the Lower Old Red Sandstone.

The identification of this Old Red Sandstone with the Devonian beds has been a point hitherto singularly destitute of proof, though its suggestion by Lonsdale, and subsequently by Austen, Sedgwick, and Murchison, in memoirs on Devonshire and on the Rhine, has been generally approved.

So little proof existed of this identity, that one of our best observers, whose research had largely tended to the establishment of the Devonian series (Mr. GodwinAusten), has recorded his doubts in the Geological Society's Journal (vol. ix. p. 231), identifying the Old Red Sandstone only with the uppermost or Marwood beds, which Mr. D. Sharpe considered as Carboniferous; while Mr. Sharpe himself placed the Old Red Sandstone at the base of the Devonian system (vol. ix. p. 20, &c.).

The fossil clue has once more unravelled a geological difficulty. Sir R. I. Murchison, in reclassifying the beds of the Old Red Sandstone of Scotland (Siluria, 2nd edit. p. 285), has shown good reason for considering the order of superposition to be as follows:-from the base,

1. Lower Old Red, with Cephalaspis, Pteraspis, Pterygotus.

2. Middle Old Red, with Coccosteus, Diplopterus, Osteolepis, Pterichthys, &c. 3. Upper Old Red, with Holoptychius, Glyptopomus, &c.

The Upper Old Red, then, being identical with the uppermost Devonian, it remains to be seen if we can find fossil links between the middle and lower members of each respectively.

It has been repeatedly shown that Coccosteus, a fish characteristic of the middle Old Red beds, occurs in the Eifel and the Harz, in strata which belong to the Middle Devonian; and in Russia* it is common to have this and other genera (Asterolepis, Dendrodus, &c.) in beds of sandstone intercalated with the marine shells.

There is still the Lowest Devonian zone, viz. the Spirifer-sandstone of the Rhine. The lower sandstones and slates of Linton, in N. Devon, and of Fowey and Torquay, in S. Devon, are its equivalents. In order to prove this zone identical with the lowest Old Red-the Cornstone group, it was needful to find some at least of the characteristic fish in it. In no Old Red locality have we any marine fossils mixed with the Cephalaspis and Pteraspis; but in one of the German localities Prof. Roemer has lately discovered, and Prof. Huxley described (Quart. Journ. Geol. Soc. 1861), a large species of Pteraspis-a fish so exclusively characteristic of the lowest Old Red as to leave no doubt whatever of the true correlation of the two deposits.

Upper, Middle, and Lower Old Red are, therefore, now linked in all their parts by fossils with Upper, Middle, and Lower Devonian.

On a Skull of the Rhinoceros tichorhinus.

By S. P. SAVILLE.

On a Whittled Bone from the Barnwell Gravel. By H. SEELEY, F.G.S. This was the proximal end of a dorsal rib of a large mammal, seemingly the Elephant, obtained by the Rev. F. J. Blake from the gravel-pit at Barnwell, near Cambridge. The specimen shows on the severed end numerous cuts, as though made to assist in breaking the bone. The author urged that, as the condition of the cut surfaces was like the external surfaces-as they had passed unnoticed till he detected them-as similar cuts could not be made on fossil bones without great care and chemical preparation, and there was nothing to suggest a doubt as to their * Siluria, 2nd edit. p. 382, 421, &c.; see also vol. xv. p. 437.

authenticity, the cuts were as old as the date of fossilization. And as bones are there only found in one band of loam, it was further urged that they might be taken as evidence of the coexistence of man in that district with the Irish Elk, Bos primigenius, Elephas primigenius, Hippopotamus major, and the other mammals of the gravel.

On a Successful Search for Flint Implements in a Cave called "The Oyle," near Tenby, South Wales. By the Rev. GILBERT N. SMITH.

This is a cave in the mountain limestone, about 70 feet above the level of the valley beneath, up which the tide has till very recently been used to flow.

Within, it is distinguished by chambers, alternating with narrow passages, penetrating 30 or 40 yards into the spur of a ridgeway of the Old Red.

Floor not more than 3 feet deep anywhere, and bearing traces at the sides of a stalagmite covering long since destroyed.

Seventy-three artificial flakes or chips were unearthed, together with the identical lumps of flint which remained after the chips were struck off, when, from their reduced size, they were no longer capable of yielding flakes sufficiently large to answer the destined purpose.

Some of the chips are of ordinary flint; some of a dull green, opake chert. In size they vary from about 4 inches in length to half an inch. In general form they are almost identical with the flakes found at Red Hill. They were disseminated through the soil of the whole cave, but much the most thickly scattered on the floor of a recess near the entrance.

Interspersed also with them through the soil, which in some places is nearly black, were a great many bones. Most of these belong to such ruminants as are now domesticated. Some are of the usual cave-mammals, as Ursus spelaus, &c. One very fine front prong of an antler lay by itself in black earth, and has marks as of a tool. Length 11 inches; circumference at base 4 inches.

The lowest portion of the soil seemed quite undisturbed, down to the rock. It is similar to the drift around the cave. Plenty of edible-mollusk shells occurred intermixed.

The investigator believes these flints to belong to the same human family that raised seven or eight tumuli which exist above on the ridgeway, which contained flint arrow-heads and a central kist vaen, or covered cromlech.

He is of opinion that these flakes are the neglected refuse of the workshop, there being no perfected flint arrow-heads among them, like those in the barrows, though there are eight broken pieces of perfected ones among the seventy-three specimens. The Welsh antiquaries here do not find mention of any weapons of stone among their ancient writings, except for sacrificial purposes,-in accordance, this, with Joshua v. 2, where flint knives are prescribed to circumcise, which Lightfoot says was a kind of sacrifice also. The most eminent Welsh scholars have been consulted by the writer.

There is no flint in the strata of this neighbourhood; and the chert, which has small white spots through it, and looks more like some fine kinds of trap, does not appear in the coast-strata, although sea-borne boulders of granite and an occasional flint may be picked up, with here and there a worn fragment of serpentine and iridescent plutonic rock.

On the Cause of the Difference in the State of Preservation of different kinds of Fossil Shells. By H. C. SORBY, F.R.S., &c.

The fact of certain kinds of fossil shells having lost their organic structure, or being entirely removed, whilst in the same bed other kinds remain almost in their original state, cannot fail to have attracted the attention of most geologists. For example, most univalve and such bivalve shells as Trigonia, and the inner layer of Avicule and Spondyli, are often altered or removed, though their outer layer and the entire shells of Ostree and Brachiopoda are well preserved. After having made a considerable number of experiments with recent and fossil specimens, the author had come to the conclusion that this difference was due to the original