**s?wifr

472 THB GEOLOGIST. smaller or ventral valve, showing that the muscular impressions were exactly similar to those observable in Spirifera; no septa existed in this valve, so that th^ shell cannot be classed with Pentamerus. None of the fragments, however, exhibited a trace of spiral processes, but this is no proof that they might not have existed. The terms Athyris and Atrypa have been made use of in this paper, but I wish it to be distinctly understood that I do not recommend their adoption. I used them as mere names, and on account of their priority of date; but, as the generality of naturalists on the Continent, and some in Great Britain, have for some time past made up their minds to repudiate both M'Coy's and Caiman's misnomers, for the reason that they invplve a zoological mistake, my readers can adopt M. d'Orbigny's substitutes of Spirigera for Athyris, and Spirigerina for Atrypa, although other denominations might have been preferable. ERRATUM. In page 412, line 19, instead of genus Atrypa, Dalm. = Spiri/erina, D'Orb., read Spirigerina, d'Orb.

THE COMPARATIVE GEOLOGY OF HOTHAM, NEAR , . By the Rev. T. "W. NOBWOOD, of Cheltenham. (Continued from page 424.) II. It is about a mile across the Lower Lias, on which the villages of and Hotham are situated, to another gently-rising ground which ascends out of Hotham Park to the eastward in a beautiful sloping bank, and being tastefully planted with stately trees, contributes very much to the charm of the scenery. Coming in with my hammer to the ancient village, in the bright and odorous evenings of midsummer, I have often been arrested by the sweetness of this place; and, enamoured of its serene and peaceful beauty, I have loitered to admire its dark plantations, and the greensward slope that I am now describing, and the illuminated wold rising high in the distance. It is the low escarp­ ment of the Middle Lias which declines thus pleasantly into the park at Hotham. As we go out of North Cave towards , this bank may be observed to rest upon soft blue shales, which have hitherto supplied no fossils. When we begin to ascend it, we may turn into a copse on the right-hand side and study the section in a marl-pit, or we may notice the roadside cutting. In either case, we shall observe that the beds change as follows:—From blue shales at the bottom and lower part of the ascent, through brown earthy-looking shales and sand with irregular broken bands of nodular clay-ironstone, one of which enclosed Fucu.xa.

l*ho« IJSCVIASOTI daL&.Ti£h. NOEWOOD—GEOLOGY OF HOTHAM. 473

a cast of Unicardium cardioides, to a hard rock-bed of the true Marhtone, two or three feet in thickness, which again is capped at the top of the ascent by a very rusty, rubbishy, and ferruginous rock. It is in the last division only that I have succeeded in obtaining fossils at this place in any quantity worth mentioning; and they are always in a very corroded and imperfect condition. The most plentiful forms are Belem- nites, and next to them, masses of Rhjnchonella tetraedra; but with perseverance and good fortune Terebratula resupinata and other charac­ teristic shells of the Middle Lias may be collected here. This zone may be traced both towards the north and south, though it does not maintain that upland character which it assumes in Hotham Park, for more perhaps than two miles of its course. It is seen in one direction, near Hotham, as we leave that village by the road to Beverley; in the other it crosses the turnpike at Everthorpe, and passes close by the castle and church of South Cave. There is a moory valley with a surface of sand and peat lying along on the north side of Hotham towards Newbald, between the escarpment of the Lower Lias on the one hand and the rise of the chalk-wold on the other; a favourite haunt, in spring and summer, of lapwings and sand-martens. Two pits, which were opened in this valley for marling, about a mile from Hotham church, have exposed a substratum of remarkable drift which is very well deserving of examination. It consists of a medley, in great masses more or less rounded, of all the surrounding formations, from the " Posidonomya- bed " to the White Chalk, and contains some organic remains distinctive of rocks which are not known at present to exist in situ anywhere in the neighbourhood of Hotham. For example, it has supplied an Ammonites cordatus, with a matrix of Oxford clay, which leads me to suspect that that rock might be found stratified no great way off, especially as the Kelloway rock occurs in its place hardly more than a mile to the eastward. The fact, too, that the formations composing this drift lie mostly to the westward of their proper lines would indicate that the great transporting waters which accumulated these ponderous and disordered masses had their origin in some eastward direction. Mixed indiscriminately in the general ruin lie large and small blocks of Middle Lias Mwlstone, dissimilar, however, in colour and texture to the marlstone which I have mentioned as cropping out near North Cave, and which may also be traced through Everthorpe and South Cave in its progress towards the . The colour of these rocks 474 THE GEOLOGIST. is more darkly ferruginous and their texture markedly oolitic or granular, though not unfrequently they change to a deep green hue, imparted to them by the protoxide of iron, when the granular structure becomes less observable. The fossils, also, which they enclose, though exceedingly distinctive and familiar, have not yet been found in situ at Hotham. They are the common forms of the true Marlstone—the " Bpinatus " and " Margaritatus " zone of Oppel and Wright—which is shown in typical seotions, as at Gretton, near "Winchcombe, in Glouces­ tershire, to occupy the top of the Middle Lias in the southern counties. I collected here the large Peoten equivalvis and P. oorneus, both of which were plentiful as usual, Belemnites, Plewomya unioides (?), Cardinia crassissima, and Ammonites Englehardti, with some others. The drift which I have been now considering contrasts remarkably, from its mixed character, with those other and almost homogeneous deposits which have been shown to cover the neighbourhood of North Cave. III. It may be about 200 yards across the Middle Lias; but its junction with the rock next succeeding is not well exhibited. The eountry is now flat to the foot of the chalk, and the sequence of the different rocks that traverse this level is partly undeterminable from lack of sections, and partly obscured by drift, so that I could not make it out with sufficient exactness. I ascertained, however, that the ferruginous beds give place to an inconsiderable band of yellow tenacious clay; and that this again is apparently succeeded by a still narrower zone of very peculiar marly limestone, which I shall call provisionally the LISNIFEBOTTS MAEL, and describe as fully as my present materials will permit. I regret that these are not more ample, which is owing, in part, to my limited opportunities. I believe this to be an exceptional bed, possibly it may even be unknown hitherto, and unrecorded in our series. Its lithological character might refer it to the Upper Lias; but its fossils in general, and particularly in one or two instances, are muoh more of Oolitio than Liassic types; and consequently I should be inclined, in the existing state of my knowledge, to assign it an inter­ mediate place between the Upper Lias and Inferior Oolite, somewhere in that " debatable ground" which has lately received such elaborate illustration from Dr. "Wright. I have reason to suspect the existence of the Upper Lias Clay at Hotham; and I shall hope to prove that I have seen there the lower portion of the Inferior Oolite, a little NORWOOD—GEOLOGY OF HOTHAM. 475

above this Marl; but, until the relative places of these rocks are accurately known, I desire to speak with great reserve of the horizon and affinities of the "Ligniferous Marl;" and shall better employ myself in discussing its appearance, so far as I have really seen and studied it, in the hope that I may induce some geologist with more leisure and experience to go down to Hotham and complete the investigation. A small opening made this year for road-stone, in the lane-side between Hotham and the turnpike, exhibits the place, breadth, and character of this limestone. Its position might argue it at first sight to be " Upper Lias;" its width is but a few yards; and structurally it is a band of sharp irregular uncompacted Stones, which may be divided, not naturally but for convenience of description, into two kinds. Those of what I shall call the first sort are com­ paratively soft and marly, of a yellowish-grey colour and general fresh-water aspect, interspersed throughout with fragmentary re­ mains of land-plants, particularly of a fern, with a frond-lobe much resembling in outline that of the common Polypody (Polypodium mlgare). The venation is generally distinctly preserved : the lobe has a prominent mid-vein, from which alternately, on either side, branch out the lateral veins, these last being twice-forked and thus divided into four branches. I am indebted to Professor Phillips for pointing out, when I lately read a paper on this subject before the British Association at Leeds, the affinities of this] fern in general; and the interesting fact which I had omitted to notice, that one specimen in my collection shows its fructification. It may probably appear that the occurrence of this fern is among the first indications in the Yorkshire strata of a series of acrogenous plants which attained to much importance after­ wards, and which have been long known to us in the "Upper and Lower Sandstone, shale, and coal" of the " Geology of Yorkshire." Portions of stems occur also in this marl, but perhaps less frequently than leaves of plants. In another division of this bed, the rock becomes harder and not so marly. It changes imperceptibly to a bluish-grey colour, and is a very useful road-metal, having a sharp splintery fracture, and a clear ringing sound under the hammer. I have adopted this conventional distinction, because I have remarked as a general rule that the wood is found mostly in the softer, and the fossil animals in the harder part; not but that these often run together, and admit of no line of separation 2 M 2 476 THE GEOLOGIST. at all. In acquainting myself with the organic remains of this rock, I found it most advantageous to work at the stone-heaps by the road­ sides where it has been broken into small pieces, rather than at the quarry where some of it is not very frangible, and where it is all ill- exposed. This will both save labour and prevent disappointment. Very few genera of animals are represented in it, and scarcely any genus by more than a single species; but the individuals are numerous, and so singularly persistent and distinctive in their forms that no better defined species could be desired. A small sea-urchin is very abundant and characteristic, but hitherto I only know it as an interior mould and cannot safely determine its genus. It is either an Acrosalenia or Pseudo-diadema; but though I have collected as many as twenty or thirty specimens in a morning I am in almost total ignorance about the test. Once, too, and only once, I met with a trace of another and larger urchin in the shape of a bit of an impression of (?) a Pedina or Hemipedina. Thus there is a fair field at Hotham for any person interested in the EcMnoiiea; and this last specimen may probably prove to be a new species. But some patience will be required for a successful hunt after these tantalizing little animals, whose shells, according to my experi­ ence, are very difficult to be met with. Pinna, Modiola, and Pecten are the principal genera of shells ; and each has a single prevalent species. I shall not pretend to have ascer­ tained these species. I neither know them myself nor can as yet obtain any reliable information respecting them. The whole zone is strange to me; and while I am desirous to describe it as fully as I can, there is much in it that I must leave for the present undecided. Any palaeontologist, being at Hotham, would have no trouble in collecting these shells; and I should be glad to show such as still remain in my possession to any geologist visiting Cheltenham. In the miscellaneous drift-bed to the north of Hotham, which I discussed when speaking of Middle Lias, there occurs a rock so exactly resembling the "Ligniferous Marl" in appearance, that I had, till lately, no doubt of their identity, though I missed from it my fern- leaves, urchins, and mollusks. And when I found in it that typical-shell of the Upper Lias, Ammonites communis, and a faint impression of another Ammonite which seemed to be A. Lythmsis, I came fully to the conclusion, for the time, that my "Ligniferous Marl" was an NOBWOOD—GEOLOGY OF HOTHAM. 477 "Upper Lias'' bed. I suggested, on this evidence, that it was probably such at the Geological Section at Leeds. My opinion, however, has since been shaken by the discovery, among my Hotham fossils, of a specimen of Sinnites ahjectm, the matrix of which leads me strongly to suspect that it was obtained from the "Ligniferous Marl." It is, then, for these reasons that I desire to leave that zone altogether sub judice until I can see it again, or until it shall be seen by some more competent person. As to the conditions of its deposit—judging from the unbroken state of all its organisms, small and frail as many of them were, with the single and remarkable exception of its rolled and fragmentary remains of land-plants, and reasoning from analogy about the habitats of the fossils themselves during life, it would appear that this bed was very tranquilly laid down in a shallow sea, near the mouth of some ancient river which watered a land with a genial climate, and bore away, amid the spoils of its banks and jungles, a fern related to the common Polypody. IV. Proceeding from the " Ligniferous Marl" pit" towards Drewton, we immediately come upon a thin bed of chalk-drift, which conceals the contact of the subjacent rocks, and arrive, in about 100 yards, as nearly as I can remember, at a large Oolitic quarry on the right-hand side. I am at present unable to say by what kind of transition the marl-band passes into this very dissimilar Oolitic rock ; but obviously this is a point which it would be very interesting to clear up. "Hotham Quarry " is one of many more such like, which follow the line of these oolites northwards from the Humber, and were, no doubt, opened originally for the erection of the neighbouring villages and churches, the last being chiefly of Norman foundation. Several of these old quarries have been partially filled up and brought again under the plough in recent times; as is the case with those at Drewton, which, with one inconsiderable exception, are now only to be traced by inequalities in the ground. For the most part, however, they remain open still; and, where they are not grass-grown but continue in use for the roads or for lime-burning, they afford excellent facilities for geological examination. It is possible that they might be found, upon a survey, to be situated in different Oolitic zones; and so would require to be studied for some distance north and south, in order to obtain a full and perfect exposition of the Oolites at Cave. Hence it will be necessary for me to confine myself in this description, 478 THE GEOLOGIST. with very little deviation, to the path which I have chosen through the village of Hotham, nearly at right angles to the direction of the strata. The Oolites along my route oommence at Hotham Quarry with what I believe to be the lower portion of the Inferior Oolite; for it answers, with considerable exactness, lithologioally as well as zoologically, to the "Pisolite" or " Roestone " of the neighbourhood of Cheltenham, which has been hitherto affirmed to be a local formation limited to that special vicinity. They end, after a breadth of about three-quarters of a mile, where the Kelloway Eock is succeeded by the Eed Chalk under the edge of the wold at Drewton,—both of these deposits being very rich in their distinguishing forms of organic remains, and corresponding to their equivalents in "Wiltshire and Norfolk. I shall confine myself, therefore, in this paper to the geology of Hotham, and to stating, as summarily as possible, my reasons for thinking that Hotham Quarry is in the Inferior Oolite—a formation which, therefore, is not wanting in this long uncertain district of Cave, though its appearance here is somewhat strange and degenerated, and implies a peculiarity in its deposit. The Hotham Oolite, in the Upper part, is a white-coloured, thin- bedded rock, coarse and fissile, and of a decided " roe-stone " aspect, which, somewhat lower, becomes largely intercalated with layers of sand, and is seen at the base of the section, which is probably nowhere twenty feet deep, to have become altered into a thick-bedded sandy freestone. Its fossils cannot be said to be plentiful. Most frequently we find broken remains of Echinodermata, such as oceur in the " Pisolite " of the Cheltenham Inferior Oolite; and, so far as I am a judge of the associated mollusca, they go to confirm the testimony of the urchins, and the evidence from " pisolitic " appearances. I subjoin a list which I have succeeded in collecting, not without a good deal of attention and perseverance ; and, like all other fossils recorded in this paper, they were obtained (with the exception of one) with my own hands. Undoubted specimens, generally in bad preservation, of Pygaster semisulcatus, which is perhaps the most common form of all; a large fiat Clypeus, so like at first sight to ffyhoclypw agariciformis as to deceive an experienced eye, but distinguished upon close inspection by the character of the ambulacra, and poriferous zones—I consider it to be the Clypeus Michelini of Wright, but I have never found a good and sound exa,mple of it, although bits of its test are not rare; a cast of (?) Acrosalenia ; a species of Pseudodiadema, (not depressum,) only known at present in a mould with a small remnant of the test upon it; slabs with plaUs and spines of urchins, Pentacrinites, and Millepores; Ilinnites NORWOOD—GEOLOGY OF HOTHAM. 479

abjectus and H. velatut; Lima duplicata; Pecten demissus; a small variety of Trigonia costata; a large flat Pinna; and species of Qstroza, Modiola, and Nerinma. Mr. Lycett, however, has recorded his opinion that "perhaps the genus Nerinm has not been found in any deposit older than the Oolite- Marl." I am disposed to attach considerable stratigraphical importance to the well-ascertained occurrence of Pygaster semisulcatus at Hotham quarry, because Dr. Wright, than whom there is no higher authority on the question, has said in his great " Monograph on the Oolitic Echinodermata" that "it is extremely doubtful whether Pygaster semisulcatus has been found as yet out of the English Inferior Oolite ;" and he adds that two distinct species of the genus Pygaster exist in the Oolites in Yorkshire—viz., one collected from the Inferior Oolite of Whitwell, and the other (P. umbrella) from the Coralline Oolite of Malton. Assuming, then, on this testimony, that the Inferior Oolite is found at Hotham, it appears to be bounded approximately towards the east by the high-road from South Cave to , just beyond which another rock crops out in a sand-hole. In the large quarry belonging to North Cave, which may be found near " Castle Farm," adjoining that of Hotham, the stone seems more brecciated, and its fossils are very fragmentary. Its slabs are overlaid with Millepores and debris of Echinodermata. The small hole which yet remains at Drewton, and is used for burning lime, has much the same lithological character which I have ascribed to the beds at Hotham; it is sandy and comparatively un- fossiliferous, and its place is some distance to the west of the turnpike, nearly in a line with the two larger pits aforesaid. I collected there, after much trouble and several inspections, a well-preserved Pseudo- diadema depression in no way distinguishable from Cotswoldian Inferior Oolite specimens, and a piece of Pygaster semisulcatus. This convinced me that I was still in the Hotham zone; and I could detect no change in the rubbish on the ploughed lands till I reached the high-road. It will no doubt be thought that this zone presents but a very scanty fauna in comparison with the Cotswold Pisolites. And indeed there is a marked absence of many things which might have been, expected, particularly of the Braehiopoda. I suspect, thea, from the quality of the rock itself, the state in which its fossils are found, and the striking dearth of deep-water remains, that we may have here a brecciated and littoral condition of the Inferior Oolite sea; which is perhaps not contrary to what we should expect when we remember the peculiar character of the " Ligniferous Marl" below. This completes what I have to say about the Geology of Hotham, to which I propose to restrict myself for the present. 480 THB GEOLOGIST. DESCRIPTION OF THE SECTION OF THE UPPER GREEN­ SAND AT THE UNDERCLIFF, IN THE ISLE OF WIGHT. BY MB. MAEK W. NOBMAW. As the practical value of local details is admitted by all geologists, I have contributed the following statement of the Upper Greensand strata strata in the Isle of Wight, thinking it might prove of interest to the readers of the GEOLOOIST. The following table will convey at a glance the relative position and thickness of the beds, and will serve to make the general observa­ tions more readily intelligible:— SECTION OF THE UPPER GREENSAND.

GBEY CHALK OE CHALK MABL.

LOWEB CHALK OB CHALK MABL. ! m UPPER GBEENSAND.

1—Phosphatic Marl - - - Very fossiliferous.

2—Chloritic Marl - - - - • Fossiliferous. Fossils. One of the beds of 8—Great Chert Bed chert contains fossil coni­ ferous wood, silicified. 4—Rag or blue limestone, and sandy \ beds and cherty sandstone .. / Bones of Saurians.

5—Firestone • Fossils.

6—Freestone beds, alternating with') Fossils rare. Those found blue rag - - j are chiefly Pcctens, and are well preserved. 7—Sandstone beds, containing sandy" concretions, with beds of rag, Fossils. Siphoniie, Ammon­ including the " Whill Rag," ites, Gryphoece, Serpulce, and terminating with the "Big Rag Bed." ------

8—" Malm Bed," consisting of beds'] 52 of tough sandstone, with layers i Fossils. Ammonites, Eehi- of rag in detached masses or j to nites, Astacut, fyc. nodules ------j 60 9—A thick layer of sandy concretions," to mottled withblack,and differing Fossils. Lima, Inoceramus, both in texture and substance Serpulce, 8;c. from the beds above, the lower 109 portion of which is termed the '• Rubble Gault."

GATTLT

NOTE.—The figures in the first column denote the average thickness of the beds described; the second column gives the total thickness of the whole series. NORMAN UPPER GREENSAND OF ISLE OF WIGHT. 481

1st. The upper portion of the section is subdivided into two parts, being in fact two distinct deposits, differing materially in mineral character, and almost distinctly in their organic remains ; for instance, the first division contains numerous species of Ammonites, amongst which the most conspicuous are A. varians, A. Mantelli, and A. Coupei in all its varieties, with numerous other shells that never occur in the Firestone below, or, indeed, in any other of the beds throughout the series, although they are met with in the chalk-marl above, to which it evidently approximates, being of a much lighter colour than the beds below. It is termed trie " Phosphatic marl." The organic remains are for the most part water-worn, and exist in the state of casts, especially the Ammonites, which are so numerous that, judging from the profusion of their remains, they must have literally swarmed in the sea of that period. 2nd. At the bottom of the before-mentioned deposit, we como upon a bed of fantastically-shaped nodules, varying in size from a few inches in diameter to a foot, amongst which may be found the water- worn remains of a gigantic bivalve, termed " Radiolites," teeth and bones of Saurians, hook-shaped teeth, &c. Below this, again, is a thick bed of dark-green, soft sandstone, readily weathered. This bed I believe to have been named the " Chloritic marl," by geologists. At the bottom of it is another layer of nodules, similar in character to those above, containing also the teeth and bones of saurians as well as of sharks, with other fossils, the most characteristic being the Pecten orbicularis, which abounds. 3rd. The next division consists of layers of siliceous sandstone and beds of rag, alternating with beds of coarse, brittle, flinty masses, or coarse chalcedony, locally termed " shotterwit," which is much used for the making and mending of roads, as is also the limestone or rag. It is very brittle, and easily broken into square fragments; and is almost destitute of organic remains, but the large Pecten quinque-costattts is sometimes, though rarely, found; but, being imbedded in a flinty matrix, it is seldom extracted whole. The same shell also ranges through the four alternate layers of rag and chert, but the writer has met with no other fossil remains, except coniferous wood. 4th. The next beds in descending order consist of hard, brittle stone, spongy in texture, and strongly impregnated with silex, break­ ing, like the preceding, into square fragments. They are interspersed 483 THE GEOLOGIST.

with layers of rag, and are called by the quarrymen, the " Cock-beds." The organic remains consist of sponges, zoophytes, Pecten quinque* costatus, and a large Terebratula, but these are sparingly found. The beds are twenty-four in number. 5th. We now come to a succession of beds of chert and sandstone. One bed, about nine inches or a foot thick, is called by the masons the Firestone, and is most probably the equivalent of the rock so-called in Sussex, and described by Dr. Mantell, who denominated the whole of the series as " Firestone," but which appears from his description to have thinned out considerably in that locality, and to have become amalga­ mated with the chalk-marl. Still, the fossils he describes as belonging to the Firestone at Southbourne are never met with in the Isle of Wight below the Phosphatic Greensand, nor does the chalk-marl ever appear in the whole section of the Undercliff, a distance of nine miles from Shanklin to Blackgary, below the Firestone, or Upper Greensand, as exhibited in his section of the beds near Southbourne.* Again, at page 164, he says the "Firestone contains the same fossils as the Grey marl; " but one, at least, which he enumerates, the Ostrcea carinata, is a characteristic fossil of the two beds, the phosphatic and chloritic greensands, capping the fireBtone in this locality, and is very rarely found below them. Ammonites planulatus also occurs higher up in the same bed, but I have never met with it in those below. I have merely mentioned these discrepancies with the view of calling attention to the fact, namely, that all the fossils which Dr. Mantell has described and figured in his work on the " Geology of the South-east of ," as belonging to the "Upper Greensand," or "Firestone," belong to the two upper beds of the "Phosphatic Greensand," and to the " Chalk Marl" in this district; whilst neither in the list there appended, nor elsewhere, has he described or enumerated any of the characteristic fossils of these deposits which occur in the Undercliff- series of the Upper Greensand, namely, the Pecten quinque-costatus, the large Ammonites, Ancyloceras (or Samites), &c. " The Fire-stone group" of Dr. Mantell includes those twenty-four beds above described, but the term is restricted in this locality to an upper bed, about eight inches thick, superimposed on a stratum of rag of a pale blue colour, tinted with red, very hard, about nine inches in thickness, and succeeded by another bed of fire-stone of the same thick- » Vide, Mantell's " Geology of the South-Qast of England," pp. 161—164. NORMAN—UPPER GREENSAND OP ISLE OP WIGHT. .483 ness as that above, the last resting upon the " Cock-bed," of about three or four inches thick. I consider, from my own observations, that all the fossils of the two upper beds, the " Phosphatic " and " Chloritic " marls, ought, with few exceptions, to be referred to the chalk-marl; but not those below this very clear line of demarcation. The fire-stone, when first quarried, is of a soft texture, but hardens by exposure to the atmosphere; it is fire-proof, and used by masons in fixing grates, for oven-bottoms, and other purposes where endurance of heat is an essential quality. It was from the beds of rag in this group that the fossil bone of a terrestrial animal, described at page 179 of Mantell's "Excursions round the Isle of "Wight,"* was obtained in a quarry (now closed) near the Bonchurch Hotel. This relic is now in the possession of — Hanbury, Esq., and the writer of this has seen a good wheelbarrow-full of bones of an animal, apparently Saurian, dug out of the same quarry; but from their decomposed state, these were too friable to permit the preservation of a single specimen. A few teeth were secured, but, owing to this cause, they fell, shortly afterwards, to pieces by exposure to the atmophere. These remains were obtained from the lowermost bed of the "Phosphatic Greensand." 6th. The next beds in descending order are important ones in an eco­ nomic point, from their great utility as a building-material, and the consequent demand for them for suoh purposes. Their place in the series of deposits forms a well-marked epoch or line of demarcation in the history of the " Upper Greensand; " they may be divided into five sections :—The first is a bed of grey sandstone, about one foot thick, called by the quarrymen the " Top Bed," succeeded by a layer of rag- stone from eight to nine inches thick; thirdly, another bed of sandstone of about the same thickness as the rag; fourthly, a thick bed of freestone, often considered to be analogous to the Portland building-stone, but erroneously so, being different in composition and mineral character, and evidently consisting of a mixture of grains of silex and, probably, of iron, cemented by carbonate of lime; the roe-like particles of the Portland-stone being really wanting.f The fifth bed consists of the ° Page 247, Editions of 1847 and 1861. t I have mentioned this because of a popular error that exists amongst the masons and others of this locality, namely, of the identity of the free-stone with that of the Portland rock; an error which, of course, BO geologist would fall into. 484 THE GEOLOGIST. free-stone proper, averaging four feet in thickness, and being about thirty-four feet from the top of the " Upper Greensand." It is succeeded by a thick bed of darkish-blue rag, and a bed of chert, the last in the series. The 7th division has a depth of about thirty-nine feet, and is com­ posed of thick beds of fine sandstone, alternating with beds of blue rag; it may be divided into fifteen strata. The first is a bed of yellowish sandstone, about three feet in thickness, full of a species of Siphonia, nodules with a sponge-like texture, remains of Polyparia, very large Ammonites, Nautili, and nodules of rag. Below this is another layer of rag, a foot thick, succeeded by a bed of fine sandstone of a softer nature than the one above, and extending to a depth of about three feet. In contact with the last is a bed of tough sandstone a foot thick, locally termed the "Black-band," and containing fossils. The writer has now in his possession the claws of an Astacus (?), which must have belonged to an individual more than a foot in length. He has, besides, from this band, a species of Echinus (?). To this sandstone several alternating bands of light sand with thin belts of the " Black-band " succeed, the whole amounting to about seven or eight feet in thickness. Below this, again, are stratified layers with nodules, termed " Whill- Bags," in shape like a compressed cone, many of which are two feet in diameter, and most of them containing organic remains as nuclei. They are very hard and tough, and difficult to break. They are, how­ ever, much used by builders in the construction of sea-walls, and for the front-walls of dwelling-houses. On being cloven or split by the quarrymen, by means of very large wedges inserted in a hole made by a mallet and chisel, and afterwards driven in with a weighty sledge­ hammer, they are often found to contain Ammonites of very large size, with the mouth entire; and a fine species of Astacus (?) is reported to have been thus obtained from one of them some years ago by Mr. Saxby. The writer has seen some magnificent specimens of Ammonites in the possession of Dr. Leeson, one of which, about sixteen inches in diameter, was obtained whilst sinking a well at Bonchurch. It is, perhaps, worthy of remark in this place that the fossils are generally found at the base of the " Whills."

(To he continued.J