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]
[Footnote 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.]
[Illustration: Plate XXXIX.]
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.
[Illustration: Plate XL.]
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.
[Footnote 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])
[Footnote 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.
[Illustration: Plate XLI.]
PLATE XLI.
A Silicified cup-shaped Sponge, from Touraine.
(_Chenendopora Parkinsoni_, of Michelin.
_Spongites Townsendi_, of Mantell.)
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]
[Footnote 31: Wonders of Geology, vol. ii. p. 637; and Medals of
Creation, "Excursion to Faringdon," vol. ii. p. 923.]
[Illustration: Plate XLII.]
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]
[Footnote 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.
[Footnote 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]
[Footnote 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.
[Illustration: Plate XLIII.]
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.
[Illustration: Plate XLIV.]
PLATE XLIV.
Fossil Zoophytes.
Fig. 1. A spongite (_Scyphia costata_, of Goldfuss), from
Switzerland. The fossil spongeous bodies named _Scyphia_,
are characterized by the "mass or body being either
cylindrical, simple or branched; fistulous, and terminating
in a rounded pit; entirely composed of a firm reticulated
tissue."[35] Like the other bodies comprised in the group
of Amorphozoa, the form in this genus is exceedingly
diversified, and as the structure is often but obscurely
shown, the determination of these fossils is oftentimes
impossible. It is however convenient, in the present state
of our knowledge, to distinguish the principal kinds by
names which may be modified or abandoned, when the structure
and natural affinities of the original organisms are more
accurately determined.
[Footnote 35: Medals of Creation, p. 237.]
Fig. 2. Another species of Scyphia from Switzerland; a small
portion of the surface magnified is seen at _a_.
Fig. 3. The peculiar form and tissue of another genus of
Amorphozoa (_Cnemidium rimulosum_, of Goldfuss), are shown
in this beautiful specimen.
Fig. 4, is a section of a chalk flint, from Wycombe Heath; the
purple body, partially invested by a white border, is
evidently a mass of the soft parts of some zoophyte, which
served as a nucleus to the siliceous nodule. A purple
or pink hue often prevails in the sections of zoophytes
immersed in flint, and doubtless depends on the original
colour of the living animal.
Fig. 5. A very fine spongite (_Chenendopora fungiformis_, of
Michelin), from France.
Fig. 6. This is evidently a fossil zoophyte, but the structure
exposed is not sufficiently characteristic to determine the
genus.
Fig. 7. A beautiful fungiform Scyphia.
Fig. 8. This elegant specimen, which Mr. Parkinson highly valued,
is evidently a _Choanite_ imbedded in flint. The body
retains a pink colour, and is surrounded by a white band,
which is probably the remains of the cortical or external
tissue of the original zoophyte. I have seen many transverse
sections in which the central mass was either of a pink or
purple colour, and encircled by a white zone, in the squared
flints of the walls of churches and other ancient edifices
in Sussex.[36]
[Footnote 36: Polished specimens of the pebbles of the Isle of Wight,
exhibiting sections of the Choanites, Ventriculites, &c., may be
obtained of _Mr. Fowlestone_, Lapidary, 4, Victoria Arcade, Ryde;
who also has generally on sale a good series of the fossils of the
Island. The minute organisms that occur in flints, many of which are
highly interesting objects when seen by transmitted light under a
good microscope, can be procured of _Mr. Topping_, that well-known
preparer of microscopic objects, New Winchester Street, Pentonville
Hill; and fossil infusorial earths, &c. in great perfection of _Mr.
Poulton_, Microscopic Artist, Reading, Berks.]
[Illustration: Plate XLV.]
PLATE XLV.
Fossil Corals and other Zoophytes.
Fig. 1. "A fossil body, from near Bath, the surface of which
is covered by stelliform markings, which seem to have
been formed by a coralloid."--_Parkinson._ This fossil
is supposed by Mr. Morris to be the cast of one of those
mollusca which form and inhabit hollows in stone, coral, &c.
(hence termed _Lithodomi_). In the present instance, the
mollusk had bored into a mass of coral, the imprints of the
stellular polype-cells of which remain on the surface of the
cast. It closely resembles fig. 3, Plate XXXVI. of Faujas
St. Fond, Hist. Mont. St. Pierre, which is described as a
coral; it is the _Astrea geometrica_, of Goldfuss.
Fig. 2. A fossil coral from Maestricht. At _b_, is shown an
enlarged view of one of the stars.
Fig. 3. "A siliceous fossil from Essex."--_Mr. Parkinson._
(_Ventriculites racemosus_, of Mr. Toulmin Smith.) I must
confess myself unable to determine the nature of this
specimen.
Figs. 4, & 6. Corals from the cretaceous strata of St. Peter's
Mountain, Maestricht (_Gorgonia bacillaris ?_ of Goldfuss).
At _a_, is shown one of the cells in fig. 6, magnified.
Fig. 5. A pebble, split asunder, exposing the remains of a
spongite, which formed the nucleus of the flint.[37]
[Footnote 37: For an account of the formation of flint, see Wonders
of Geology, vol. i. p. 300. (_6th Edition._)]
Fig. 7. Another spongite in a pebble; from Sewardstone, Essex.
Fig. 8. A water-worn, silicified, or rather chalcedonic
Ventriculite, from France.
Fig. 9. A very beautiful transverse section of the stem of a
Ventriculite in a flint; the colour of the original being
retained. This was another precious gem in the estimation
of the amiable author of "The Organic Remains of a Former
World."
Fig. 10. A portion of a Choanite in flint; from gravel, Islington.
Fig. 11. A perfect specimen of a small simple coral (Fungia),
from Maestricht.
Fig. 12. A spongite in a pebble; similar to fig. 5. Such
specimens are very common in the shingle along the sea-shore
at Brighton, Dover, &c.
Fig. 13. A fossil coral in limestone, from Maestricht. It is too
imperfectly defined to determine the species or genus; an
enlarged sketch of the structure is given at _c_.
[Illustration: Plate XLVI.]
PLATE XLVI.
Pentacrinus.
Fig. 1. Specimen of a recent _Pentacrinus Caput Medusæ_, from the
Caribbean Sea.
The Lily-shaped animals (_Crinoidea_), so named from a fancied
resemblance of some species when in a state of repose to a closed
lily, may be compared to a Feather-star (_Comatula_) fixed to
a jointed column, with its mouth upwards; the base of the stem
being attached to the rock by root-like processes. The only known
living genus inhabits the seas of the West Indies, and the specimen
figured represents the body (or upper part of the animal), with a
considerable portion of the stem remaining attached. The Crinoidea
are divided into two groups; Encrinites, having the ossicula
(little bones) of the stem rounded, and Pentacrinites, in which the
ossicula of the column are pentagonal, or angular. The Crinoidea are
characterized by having a fixed base, a column or stem composed of
numerous separate articulated pieces of a solid calcareous substance,
supporting on its summit a vase, or receptacle, formed by a series
of closely adjusted plates, which contain the body, or viscera. The
upper part of the receptacle is covered by a plated integument, on
one side of which an aperture or mouth is placed. From the upper
margin proceed five articulated tentacula or arms, which subdivide
into branches that in some species are very numerous and of extreme
tenuity. On the inside, the arms are beset with articulated cirri or
feelers. The joints composing the column are perforated by a central
opening; there are also side-arms, that radiate from the column in
groups of five at different points. When the animal is alive, the
skeleton is covered by a soft integument, as in the star-fishes, and
the arms spread out and expand, forming a net, by which living prey
is captured and conveyed to the mouth by the tentacula, in the same
manner as in the fresh-water polype or Hydra.
The fossil remains of Crinoidea consist of the ossicula of the
column, arms, and tentacula; of the plates of the vase, or
receptacle; and of the peduncle, or base of attachment. This family
of Radiaria, though now of such excessive rarity, swarmed in the
seas that deposited the ancient secondary strata; whole mountain
chains and extensive tracts of country are composed of strata almost
entirely made up of their fossil remains.[38] The number and species
of genera is very great.
[Footnote 38: Wonders of Geology, vol. ii. p. 645. Medals of
Creation, p. 312.]
Fig. 2, is a remarkably beautiful specimen of the receptacle of
a Pentacrinite from Gloucestershire, showing the arms
introverted, as if the animal had suddenly perished while in
the act of closing over its prey; the stem is wanting.
Fig. 3. A spongite (_Chenendopora subplana_, of Michelin) from
the greensand of the Vale of Pewsey, in Wiltshire.
[Illustration: Plate XLVII.]
PLATE XLVII.
Fossil Remains of Crinoidea.
In this beautiful plate Mr. Parkinson has figured a great variety
of ossicula and portions of stems belonging to many species and
genera of Crinoidea; the markings or sculpturing on the articulating
surfaces of the columnar ossicula are represented with great
accuracy. It is not within the plan of this work to give detailed
descriptions of these numerous detached parts; a few of the most
interesting objects only will be particularized.
The specimens figured in the upper part of the plate, figs. 1 to 28,
are cylindrical ossicula, and portions of stems of Encrinites: those
in the lower division are for the most part pentagonal, and therefore
belong to Pentacrinites.