PLATE XXIX.
"Trifoliate Sphenopterite."
This is a rare species of fern from the coal shale of Yorkshire, Elsecar Colliery. It has the leaf or frond tripinnate; the pinnæ, lobes, or wings, alternate with an odd one; the leaflets are ternate, with roundish, convex lobes.
This plant has been referred to the tropical ferns, and is nearly allied to the genera Davallia, or Cheilanthes; but from the almost general absence of the organs of fructification in fossil ferns, it is impossible to refer them with any certainty to living genera. It belongs to the Sphenopteres, or wedge-shaped-leaf ferns, of M. Brongniart.
A, shows the cast or matrix of the under side of the leaf; B, the upper side in relief.
PLATE XXX.
"Milton Filicite."
This exquisite specimen exhibits part of two leaves attached to the stem, the under surface of the fronds, on which the fructification is beautifully displayed, being exposed. The frond is tripinnate, the stipes large and strong, the leaflets linear with the tip rounded. The fructification is arranged in lines near the margin; but slight traces of the venation of the leaflets are distinguishable.
From Milton, in Yorkshire.
PLATE XXXI.
"Plumose Pecopterite."
This elegant fern is characterized by the plumose or wavy character of the stipes or stems of the fronds, which are tripinnate; the leaflets are lanceolate and sessile,—that is, are closely attached by their base, without a stalk. The fructification is seen disposed near the margins of the leaflets on the left hand upper part of the specimen.
From the same locality as the last.
PLATE XXXII.
"Decurrent Filicite."
The drawing represents but a small portion of the specimen, which indicated a plant of gigantic size.
"The leaf or frond of this fern is very large, tripinnate or quadripinnate; the stipes is broad and undulated; the leaflets are sessile, linear-lanceolate; the ribs pinnate, the secondary ribs perpendicular to the main rib; the first leaflet on the superior side of the pinnule adheres by its side to the rachis."—Artis.
This fern, which closely resembles some recent species, (Pteris aurita,) occurs in great abundance in the shale at Alverthorpe near Wakefield. Notwithstanding the profusion with which the foliage of many kinds of ferns is distributed throughout the coal formation, the undoubted stems of tree-ferns are so rare, that it may admit of question whether some of the leaves which from the analogy of their structure to recent forms have been referred to the ferns, may not have belonged to the stems of unknown trees with which they are associated in the strata; for as, in the animal kingdom, distinct types of living organisms are often found blended in the extinct races, so in the vegetable, it is possible, that foliage and stems, of apparently discordant types, may have belonged to the same extinct species or genus of trees. This problem can only be solved by diligent and continued research in the richest localities of coal-plants.
M. Brongniart remarks that every bed of coal is the product of a special vegetation, often different from that which preceded, and that which followed it. Each bed thus resulting from a distinct vegetation, is characterized by the predominance of certain impressions of plants, and the experienced miners distinguish in many cases the beds they are working, by their practical knowledge of the plants that prevail.
The same beds of coal, and the deposits which cover it, ought therefore to contain the different parts of the plants that were living at the period of its formation; and by carefully studying the association of these different fossils, forming thus little special floras, generally of but few species, we may hope to acquire data by which we may advance the means of reconstructing the anomalous vegetable forms of the ancient world. M. Brongniart strongly urges attention to this circumstance in the examination of the coal strata, with the view of determining the identity of the scattered leaves, stems, and fruits, in any particular stratum. By such a procedure, much addition would be made to our knowledge of the entire structures of many of the fossil plants of which we now only know the fragments. Thus we may hope to ascertain the foliage of the Sigillariæ, the roots of which, by a similar method, have but recently been determined to be the fossils called Stigmariæ.
PLATE XXXIII.
"Carpolithe, or Fossil Seed-vessel."
The carbonized husks or shells of nuts, and other carpolithes, or seed-vessels, are not unfrequently met with in the coal and coal-shale. In the slab of shale figured, there are three specimens of an oval nut, B, C, which is striated longitudinally. These are associated with other vegetable remains, among which part of a Lepidostrobus, the supposed cone or strobilus of a species of Lepidodendron (see description of Plate IX.), is conspicuous at a.
Plates XXXIV. to LXXIV. inclusive.
PLATE XXXIV.
(Plates XXXIV. to LXXIV. inclusive, are from Parkinson's Organic Remains.)
Fossil Tubipore, from Derbyshire.
The specimen figured is a mass of limestone, on the surface of which is spread out in high relief a delicate tubiporite, or fossil coral, allied to the Tubipora, or "Organ-pipe coral," so generally preserved in cabinets of natural curiosities, from the beauty and elegance of its crimson tubes. The fossil, however, though somewhat resembling the recent coral in its general form, belongs to an extinct genus.
This Syringopora appears to have been very abundant in the sea in which the strata of mountain or carboniferous limestone were deposited, for it forms entire beds of great extent. A beautifully figured marble results from this coral, when the interstices of its tubes have been filled up with compact calcareous matter. A small polished slab is represented in fig. 2. At Matlock, vases, and other ornamental articles, are made of it; and the sections of the coral tubes impart considerable variety of figures.[25]
[25] Articles of this kind may be obtained of Mr. Tennant, 149, Strand.
Some slabs of this fossil coral are of a dull red hue, which there is every reason to conclude is due to the colour of the original; and not only are traces of the natural tints of the living zoophyte preserved, but even the animal membrane of the coral; and this may be exposed by immersing a fragment of the marble in dilute muriatic (hydrochloric) acid. Mr. Parkinson thus describes the result of his first experiment:—
"A fragment of the marble (Plate XXXIV. fig. 2) was exposed to the action of muriatic acid in a very dilute state. As the calcareous earth was dissolved, and the carbonic acid escaped, I was delighted to observe the membranaceous substance appear, depending from the stone in light, flocculent, elastic flakes. Many of these retained a deep red colour, and appeared in a beautiful and distinct manner, although not absolutely retaining the form of the tubipore. A faithful representation of this appearance is given in fig. 3."
This experiment of Mr. Parkinson was highly important, as proving the previously almost incredible fact, that animal membrane, when hermetically sealed, as it were, in the solid stone, was as indestructible as the rock itself. It suggested, too, the probability that vestiges of other animal tissues might be traced in organic remains, and encouraged subsequent observers to seek for evidence of the soft parts of animal bodies entombed in the strata. It was the first step in the right direction, and led to the detection of many highly interesting phenomena. In Dr. Buckland's Bridgewater Essay will be found figures and descriptions of the eyes of crustacea: of the wings, elytra or wing-covers, and the integuments of the body of insects; of the skin of reptiles; and, in the "Wonders of Geology," and "Medals of Creation," of the membranes of the air-bladder, and of the capsule of the eye of fishes; of the soft parts of the animalcules called foraminifera, &c. The bodies of mollusca, or shell-fish, converted into a dark brown mass (mollushite), occur in such abundance in some deposits, as to yield a rich manure from the quantity of phosphate of lime. The excrementitious substances termed by Dr. Buckland "Coprolites," are also used for agricultural purposes.
PLATE XXXV.
The subjects here figured are Fossil Corals.
Fig. 1. (Syringopora ramulosa.) A fragment of another species of the coral previously described; from the mountain limestone.
Fig. 2, represents four connected tubes of the recent organ-pipe coral (Sarcinula musica) of New Holland, to show the structure of this type of Zoophytes. Coloured figures of the live polypes of this coral are given in Wonders of Geology, sixth edition, vol. ii. plate vi.
Fig. 3. A polished slab of marble, the white markings in which are produced by sections of the tubes of the same species of coral as that represented in fig. 1.
Fig. 4. (Catenipora escharoides.) The fossil here delineated is well known to collectors by the name of "chain-coral" derived from the elegant cateniform markings produced by transverse sections of the parallel tubes, which being of an oval form, and in close apposition, give rise to chain-like figures, as shown in figs. 5 and 6. From Dudley.
This fossil coral abounds in that division of the Silurian formation termed the Wenlock or Dudley limestones, wherever these deposits occur. The most exquisite specimens are obtained from the Falls of the Ohio, at Louisville, in the United States of America. A coral reef of the Silurian epoch here exists in the bed of the mighty stream of fresh water, almost as perfect as when growing in its native sea! The river dashes over the entire mass in the season of high water; but in those periods when the stream is low, the ridge of coral is exposed, and its surface then presents the most extraordinary display of Silurian corals, of numerous species and genera, standing in relief on the more compact masses of the rock. The substance of the corals, being siliceous, resists the action of the cataract, while the softer calcareous matter which filled up the interstices of the tubes, lamellæ, &c. of the zoophytes, is washed away atom by atom; and natural dissections are formed, which art would in vain attempt to imitate. Dr. Yandell, of the Medical College, Louisville, and Dr. Clapp, of New Albany, have splendid collections from the Falls, which every geologist and intelligent traveller who visits Kentucky should not fail to examine: the masses of Astreæ, Madrepores, &c. are so fresh in their aspect, as not to be readily distinguished from the recent specimens of the same genera which are placed beside them.[26]
[26] See Sir Charles Lyell's Travels in the United States; and Drs. Yandell and Shumard's "Contributions to the Geology of Kentucky." Louisville, 1847.
Fig. 5, is a transverse section of a mass of chain-coral from Dudley.
Fig. 6. The same, as seen by transmitted light.
PLATE XXXVI.
Various Fossil Corals from different Formations.
Figs. 1, 2, 3. (Cyathophyllum turbinatum, of Goldfuss.) These three turbinated or top-shaped corals are referable to a genus of which many species are exceedingly abundant in the Wenlock or Dudley limestone of the Silurian System. They belong to the Anthozoa, or flower-like corals. The living animal, of which the coral is but the durable earthy fabric or skeleton, bore a close analogy to the sea-anemone, or animal flower (Actinia), of our coasts. Each of these specimens belonged but to a single animal: the Cyathophylla are not, like the tubipores previously described, an aggregation of numerous individual polypes.[27]
[27] For a popular account of the nature of Corals and the animals which form them, see Wonders of Geology, vol. ii. Lect. vi. p. 589.
Fig. 4. A small coral (Fungia) from Dudley.
Fig. 5. On this block of mountain limestone there are the remains of two different kinds of corals. The upper cylindrical part is a fragment of Cyathophyllum, to the lower part of which is attached a species of another genus (Michelinia).
Fig. 6, is a small coral (Fungia numismalis, of Goldfuss), common in the Oolite.
Fig. 7. A piece of encrinital limestone, from Derbyshire, having a conical cast—that is, the stone has been moulded in the interior or cavity—of a turbinated coral (Turbinolia).
Fig. 8. A longitudinal section, showing the transverse cells and lamellæ of the same kind of coral (Cyathophyllum) as figs. 1, 2, 3.
Fig. 9. A species of Turbinolia (Turbinolia complanata, of Goldfuss).
Fig. 10. A small turbinated coral (Turbinolia mitrata, of Hesinger), from the Silurian strata of Gothland.
Fig. 11. a Turbinolia from the Silurian deposits of Sweden.
Fig. 12. A remarkable coral (Petraia, of Munster), from the Devonian strata.
Figs. 13 & 14, are sections of Cyathophylla, like figs. 1, 2, 3, to exhibit the internal structure.
Figs. 15 & 16. Two elegant simple corals (Caryophyllia centralis, of Mantell), from the chalk of Kent. The form and disposition of the lamellæ of the cavity, as seen at the upper part of the specimens, are shown at a and b.
Fig. 17. A transverse and polished section of a species of Cyathophyllum, from the Devonian strata, at Blackenberg on the Rhine.
PLATE XXXVII.
Various Fossil Compound Corals.
Fig. 1. A beautiful specimen of Star-coral (Astrea ananas, of Goldfuss), from the Silurian strata of Sweden. At a, is shown "the mode in which, as in proliferous flowers, new polypes bud from the centre of the parent disk. At b, is represented the growth in the recent Madrepora stellaris of Linnæus."—Mr. Parkinson.
Fig. 2. An elegant Cyathophyllum (C. dianthus, of Goldfuss), from the Silurian formation of Sweden. At c, (the lower part of the plate,) is shown its probable mode of increase.
Figs. 3 & 6. A columnar compound coral (Lithostrotion striatum, of Lhwyd), from the mountain limestone of Derbyshire; fig. 3, is a transverse section of fig. 6, showing the basaltiform arrangement of the columns.
Fig. 4. "A fossil madrepore, from Lincolnshire."—Mr. Parkinson.
Fig. 5. A very elegant and abundant coral (Caryophyllia annularis, of Parkinson), in the bed termed "Coral Rag," of the oolite of Wiltshire, Berkshire, &c. Large conglomerated masses of this branched species form a considerable proportion of the fossil coral-reef which traverses some parts of the oolite: and when this bed is worked for road materials, blocks of this coral, more or less changed into calcareous spar, may be seen lying on the way-side. Near Faringdon, in Berkshire, a quarry in the Coral-rag has yielded many beautiful examples.
Fig. 7. Called "Spider-stone," by Mr. Parkinson. It is a species of Astrea: d, is an enlarged view of one of the polype-cells.
Fig. 8. A beautiful fossil coral, from Transylvania (apparently a species of Lithostrotion?).
Fig. 9. The specimen figured is from the mountain limestone of the Mendip Hills. (It is the Michelinia tenuisepta, of Phillips; Manon favosum, of Goldfuss?) It is described by Mr. Parkinson as "bearing somewhat of a honeycomb appearance."
PLATE XXXVIII.
Fossil Corals, and Coral Marbles.
Fig. 1, is a polished slab of the carboniferous limestone, well known as the Kilkenny marble, and much used for chimney-pieces. The figures exposed on the surface are produced by sections of enclosed corals (some species of Cyathophyllum), which are transmuted into white calcareous spar.
Fig. 2. A coral of the same kind (Cyathophyllum turbinatum), from the mountain limestone of Derbyshire.
Fig. 3. A polished slice of Derbyshire marble, the markings on which are derived from sections of enclosed branches of corals (Syringopora), resembling that figured in Pl. XXXIV.
Fig. 4. An elegant compound coral, called "Spider-stone" by collectors (Astrea arachnoides, of Dr. Fleming); from Wiltshire: the geological habitat uncertain; probably the Oolite.
Fig. 5. This specimen appears to be a cluster of corals belonging to the genus Cyathophyllum.
Fig. 6. A magnified sketch of one of the cells of fig. 4.
Fig. 7. A polished transverse section of a coral; the precise relation of this species is not certain.
Fig. 8. This is a very abundant coral in some of the beds of mountain limestone, (Lithodendron fasciculatum, of Phillips.) The specimen figured is from Clifton, near Bristol. The marble cups, and other ornaments, manufactured from the rocks near that place, often exhibit sections of this species.
Fig. 9. A mass of coral from Ingleborough, (Cyathophyllum fungites.)
Fig. 10. A polished slice of a beautiful marble richly marked by the sections of the enclosed corals (Astrea undulata, of Dr. Fleming); from Switzerland: probably from the Oolitic or Jurassic formation.
Fig. 11. Vertical section of a fossil coral, showing the transverse arrangement of the internal cells.
Figs. 12 & 13. These specimens are polished sections of a very beautiful compound coral (Astrea Tisburiensis, of Miss Benett), which occurs in a silicified state in the Portland beds that are quarried at Tisbury, in Wiltshire. Masses of chert (a kind of coarse silex or flint), wholly made up of this coral, are often met with, and when sliced and polished are extremely beautiful and interesting; the originally calcareous fabric of the zoophytes being perfectly transmuted into silex, and the interstices filled up with a similar substance, but of a different colour.[28]
[28] Specimens of the Tisbury Astrea, and of most if not all of the coralline marbles figured and described, may be obtained of Professor Tennant; and also vases, &c. of the various marbles of Derbyshire.
PLATE XXXIX.
Various Fossil Corals and Sponges, or Amorphozoa.
Fig. 1. A coral from the Dudley limestone. (Favosites?)
Fig. 2, is a vertical section of figs. 4 and 5, to show the internal arrangement of the cells.
Fig. 3. The under surface of a very common species (Favosites Gothlandica, of Goldfuss); from the Wenlock limestone of Dudley. A magnified view of part of the surface, to show the honeycomb structure, is given in fig. 7.
Fig. 4, the under, and fig. 5, the upper surface, of a small coral (Cyclolites ?) from the Oolite.
Fig. 6. A silicified branched sponge, (Spongites lobatus, of Dr. Fleming,) from the chalk of Berkshire.
Fig. 9, is a beautiful silicified, lobate, spongoid body, (Siphonia,) probably from the greensand. Siliceous cruciform spicula obtained from this fossil are represented in fig. 8.
Zoophytes of this kind, like many of the sponges, have their tissues strengthened by, and largely composed of spicula, which vary in form and size in the different species and genera. Many sponges and Siphoniæ in flint, and in the chert of the greensand, consist almost entirely of spicula, which may be easily detected by a slightly magnifying power.
Fig. 10. Another common Dudley Coral. (Porites pyriformis, of Mr. Lonsdale.)
Fig. 11. A beautiful coral (Explanaria flexuosa, of Dr. Fleming), from the Coral Rag of Steeple Ashton, Wilts. The outline indicates the mode of increase, according to Mr. Parkinson, of this form of zoophyte.
Fig. 12. This is a portion of a delicate ramose sponge (Spongites ramosus, of Mantell), whose remains are abundant in the chalk-flints, and have given rise to the irregularly branched siliceous nodules. A specimen nine inches long, with seven branches, is figured in Fossils of the South Downs, Pl. XV. fig. 11. Siliceous spicula are thickly interspersed throughout the mass.
PLATE XL.
Fossil Corals, &c.
Fig. 1. The shells of Oysters, and other mollusca, are subjected to the ravages of a parasitical sponge, (Cliona, of Dr. Grant,) which is beset with minute siliceous spines or spicula, and inhabits hollows formed in the substance of the shell. Shells thus honeycombed, as it were, may often be found on the sea-shore with the excavated parts filled up by sponge. I have shells collected by my eldest son on the shores of New Zealand, that are hollowed out in a similar manner, and occupied by sponge. Whether these cavities are produced by mechanical means, or are the result of the decay and absorption of the shell induced by the growth of the parasite, are questions still undetermined. There are several kinds of shells found fossil, which were infested with a similar parasitical sponge; and when the cavities thus produced have been filled up by flint, and the shell has subsequently decomposed, or been worn away, the surface of the flint is studded with the casts of the cells, in the form of small irregular globular bodies, connected by filaments or strings of flint. The fossil, fig. 1, is a fossil of this kind, described by Mr. Parkinson as being "covered with minute round bodies, the nature of which is unknown;" fig. 12, is an enlarged view of five of these globular casts connected by filaments.
The origin of these fossils was first pointed out by the Rev. W. Conybeare.[29] The fibrous shells of a fossil genus of bivalves named Inoceramus, of which several species abound in the Chalk, appear to have been particularly subjected to depredations of this kind. Hence among partially water-worn flints, specimens of the siliceous casts are common; figs. 8, and 10, are examples from the Hackney gravel-pits.
[29] See Medals of Creation, vol. i. p. 396, fig. 94.
Mr. Morris has named these fossils, Clionites; fig. 1, is C. Parkinsoni.
Figs. 2, 4, 7, are portions of a recent species of jointed zoophyte (Isis), from a modern concretionary deposit on the shores of the Mediterranean, Sicily.
Fig. 3. A branched fossil coral (Millepora ramosa, of Dr. Fleming), imbedded in compact oolitic limestone from Wiltshire. A portion of the surface magnified is represented in fig. 11.
Fig. 5, appears to be a fungiform Spongite; its locality is not mentioned.
Fig. 6. Portion of a fossil coral (Ceriopora), from Switzerland.
Figs. 8, & 10. These pebbles have the surface covered with casts of Clionites (Clionites Conybeari, of Mr. Morris.[30])
[30] Mr. Morris thus defines the generic character of these fossil bodies:—"Reticular masses of a more or less compressed globular, elliptical, or polygonal form; rugose and sometimes papillose; connected by minute tubuli or fibrillæ. Dendritical, dichotomous, or irregularly aggregated." Clionites Conybeari is characterized by "Cells irregular, somewhat polygonal, with one or more papillæ; surface finely tuberculated, connecting threads numerous." Note from Mr. Morris, April, 1850.
The fossils, however, do not appear to be the silicified sponge (Cliona) by which the ravages in the shell have been effected; they are merely casts of the cavities produced.
Fig. 9. Fragments of the radicle processes of attachment of some Apiocrinite or Lily-shaped animal in chalk; see description of Plate LI.
Fig. 14. A section of a siliceous nodule; probably the cellular appearance is inorganic: fig. 13, is a magnified section of the cells.
PLATE XLI.
A Silicified cup-shaped Sponge, from Touraine.
This beautiful plate of a petrified zoophyte allied to the Spongia, formed the frontispiece to Mr. Parkinson's second volume. The fossil delineated is from Touraine in France, and is one of the most perfect examples of this kind hitherto observed. It belongs to a group of cup-shaped Amorphozoa, (as these organisms are now named by naturalists, from the great irregularity of shape which they assume,) termed Chenendopora. The original organic substance is transmuted into silex, and the interstices are filled up with carbonate of lime. The same species occurs in the greensand in the Vale of Pewsey in Wiltshire, and, I believe, also in the white-chalk; for many cyathiform flints from the South Downs appear to have the same internal structure.
In the so-called "gravel-pits," near Faringdon, in Berkshire,—which are quarries of a loosely-aggregated grit of the greensand, almost wholly made up of the relics of shells, corals, amorphozoa, &c.—numerous sponges of this genus are met with. One beautiful species (Chenendopora fungiformis) has acquired, from its cup-like form, the local name of "petrified salt-cellar."[31]
[31] Wonders of Geology, vol. ii. p. 637; and Medals of Creation, "Excursion to Faringdon," vol. ii. p. 923.
PLATE XLII.
The Fossils represented in this Plate are chiefly Zoophytes in Flint.
Fig. 1. A flint from the gravel-pits at Hackney. Its form is derived from the enclosed zoophyte, part of whose structure is exposed in the upper portion of the figure. This fossil zoophyte (Choanites Königi, of Mantell) is very abundant in some of the chalk strata, and many of the most beautifully marked pebbles cut and polished for brooches by the lapidaries of Brighton, Bognor, and the Isle of Wight, are the silicified soft parts of this animal. The original was of a subglobular form, and probably of a soft fleshy consistence; it had a deep central cavity, whence numerous tubes diverged, and ramified throughout the mass; it was fixed at the base by radicle or root-like processes.[32]
[32] See Medals of Creation, p. 264. "Thoughts on a Pebble," (eighth edition,) contains coloured figures and a full description of these fossils.
Fig. 2. This is another characteristic and abundant fossil zoophyte of the chalk and flint. The specimen figured is a water-worn pebble, and therefore gives but obscure indications of the form and structure of the original. The fungiform flints—called in Sussex petrified mushrooms—belong to the same genus (Ventriculites, of Mantell): and highly interesting specimens occur in which some part of the zoophyte is invested with flint, and the other part expanded in the chalk. The original was probably a polyparium—that is, the skeleton or support of an aggregation of coral-polypes—of a funnel shape, the polype-shells being situated on the inner surface: the base was attached by root-like fibres.[33] The polype-cells are cylindrical and regular, and clusters of beautiful casts of them often occur on flints.
[33] Consult Medals of Creation, pp. 270-279: and Wonders of Geology, sixth edition, p. 638.
Fig. 3. This specimen is described by Mr. Parkinson as "a pear-shaped alcyonite from Switzerland." It is probably one of those fossil zoophytes allied to the sponges (called Siphonia), in which the upper part is of a bulbous or pear-like form, and is supported by a stem with root-like processes at the base. The bulb has a central cavity studded with irregular pores, that communicates with the parallel longitudinal tubes of which the stem is composed: a structure admitting of that ready ingress and egress of the sea-water, which this class of organisms requires. There are numerous species in the greensand of the chalk formation.[34]
[34] Medals of Creation, p. 258, Lign. 56.
Fig. 4. A variety of Siphonia (Jerea excavata, of Michelin), from the greensand of Wiltshire.
Fig. 5. A silicified Siphonia from Saumur.
Fig. 6. A Ventriculite from a gravel-pit; the markings are produced by the exposed and partially abraded outer integument, which in perfect examples consists of a regular net-work of sub-cylindrical fibres.
Fig. 7, is a transverse section of a Siphonia (Siphonia pyriformis of Goldfuss).
Fig. 8. A nearly perfect specimen of a similar fossil. In fig. 7, are shown sections of tubes passing from the periphery to the centre; in fig. 8, the central aperture of the cavity of the bulb, and part of the stem, are displayed.
Figs. 9, & 10, are imperfect specimens of Choanites: fig. 10, is a vertical section showing the central cavity and the connected tubes.
Fig. 11, is another example of Siphonia pyriformis.
Fig. 12, a vertical, and fig. 13, a transverse section, of the same species of Siphonia.
Fig. 14. A small turbinated calcareous spongite from Switzerland.
Fig. 15. The appearance of the animal membrane exposed by immersion of the fossil (fig. 14), in diluted hydrochloric acid.
PLATE XLIII.
Fossil Corals, and other Zoophytes.
Figs. 1, 2, 3, & 4, are representations of different aspects of a simple coral (Fungia polymorpha, of Goldfuss); the locality is uncertain. Fig. 1, the base; fig. 2, a magnified representation of part of the same; fig. 3, magnified view of part of the lamellated surface of fig. 4.
Fig. 5. The nature of this fossil is not obvious; it may be a rolled Siphonia.
Fig. 6, is a fine specimen of a Siphonia (Jerea pyriformis, of Lamouroux). At both extremities the apertures of the numerous tubuli are seen.
Figs. 7, 8, & 9, are varieties of the same species of fossil sponge (Scyphia articulata, of Goldfuss), from Switzerland.
Fig. 10. A spongite of a very peculiar form.
Fig. 11. A spongite investing a fossil shell (Nerita), from Faringdon.
Fig. 12, is an imperfect specimen of a Ventriculite (Ventriculites alcyonoides, of Mantell), from the chalk of Wiltshire.
Fig. 13. A calcareous spongite which has been immersed in dilute hydrochloric acid to show its structure.
Fig. 14. A pebble deriving its shape from a zoophyte apparently related to the Ventriculites (Spongites labyrinthicus, of Mantell). The aperture at the base has arisen from the decomposition of the process of attachment.
Fig. 15. A pebble enclosing part of the base of a Ventriculite; the circular spots on the large end are sections of the ramifications of the stirps or base of the zoophyte; for this figure and the following are drawn in an inverted position.
Fig. 16, is a similar fossil, split vertically, and showing the enclosed stem of the Ventriculite.