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with a pair of oblong and pointed labial palps. Branchiæ the spot where it begins to lean upon the adductor muscle in form of a crescent, and formed of detached filaments. this ventricle is flattened and lobated on each side; the Foot rudimentary, on the disk of which a club-shaped pedi auricles are similar, equal, and symmetrical ; they are a clo raises itself. . Anus Hoating behind the adductor muscle little elongated, pyriform, and their extremity is continued of the valves. (Deshayes.)

into a great branchial vessel, which soon becomes bifurcate. Shell inequivalve, adherent, auriculated, beset with The distribution of the vascular system exhibits nothing spines or rough; the umbones unequal; the lower valve particular, and resembles that of the Pectens and other offering an external cardinal facet which is flattened and acephalous mollusks. divided by a furrow, and which increases with age. Hinge We would add to the account above given of the shell of with two strong teeth in each valve, and an interme:liate this genus, a few observations which we have made, suffifosset for the ligament, communicating by its base with the ciently obvious indeed, but which have not, as far as we are external furrow. Ligament internal, the antient remains aware, been noticed. The spines with which the Spondylı of which show themselves externally in the furrow. (La-are armed, in some instances very long, must have struck marck.)

everybody, and also that they bristle out on every side from the upper valve. The lower valve is attached, and adheres to submerged bodies by means of foliations. If the whole lower surface adheres, as it often does, not a spine is given out from the lower valve; but where the adhesioa iakes effect towards the anterior part of the lower valve only, as is very frequently the case, especially when the shell is affixed among the branches of corals, a favourite locality with some species, the foliations are confined merely 10 that part where adhesion is required, and the rest, or free part of the valve, is as profuse of spines as tbe upper valve itself. There are two points to be gained, support or adhesion, and defence; the first is of primary importance, but as soon as that is safe, all the resources of the animal seem to be turned towards its defensive and offensive ar

mour. Those fishes which browse among the corals are Spondylus ducalis: internal view of valves, showing hinge, ligament, mascular impression, &c.

ihus deterred from injuring the living fixture which has a. upper valve; b, lower valve.

there taken up its abode. A very fine series of specimens M. Deshayes remarks that there are few genera better

was collected with a view to this habit, and they showed not characterized than Spondylus ; so that, kuown as it has only the power which the animal had of secreting the probeen from the days of Rondeletius and other naturalists of per process of shell according to the circumstances required, the same epoch, he has nothing to add to what Lamarck but of modifying the secretion according to the exigencies says of the shells; but, he adds, that as Lamarck gives an of the occasion. insufficient account of the animal, he will supply it.

M. Deshayes describes the animal of Spondylus as rounded or oval; ils thickness being variable in different species. As in all the mollusks of the same family, the two lobes of the mantle are disunited, except in the short extent of the dorsal border corresponding to the hinge; they are thick in their circumference, and furnished with many rows of rather lon fleshy cilia, between which, and on the internal border, may be remarked a certain number at irregular distances, truncated in the middle, and terminated by a smooth and convex surface, recalling to the mind of the observer the ocular surface of the tentacula of certain mollusks. [CONCHIFERA, vol. vii., p. 433.) These peculiar organs, he remarks, are also seen in Pecten and Pedum. He describes the adductor muscle as very large, circular, placed in the median and posterior part of the animal, and easily divided into two unequal parts. The abdominal mass is placed round this muscle, and especially at its anterior side. The mouth is situated below the an- Spondylus Americanus, with the valves closed; the umbones lowards the terior commissure of the mantle, it is surrounded with a

spectatur. large slashed lip, fringed on the edge and accompanied on But there is another, and more interesting phenomenon, each side with a pair of palps, but little elongated, in the well displayed in one of the species of this genus. Professor form of myrtle leaves. The mouth communicates with the Owen, having been led to reflect, while considering the stomach by a sbort and rather wide esophagus. The uses of the camerated part of the shell of NAUTILUS, upon stomach is elongated, pyriform, conical, and continues the degree or extent of that structure as possibly dependent itself by its pointed extremity into a cylindrical and slender upon the mode of growth of the animal and its shell

, and intestine; this makes a single great convolution in the bow far it was a necessary physical consequence of the inthickness of the liver, or rather, a great ansa having the crease and change of position of the animal, independently sides parallel. It mounts again towards the dorsal border of any special purpose served by the forsaken parts of between the stomach and the adductor muscle, gives sup- chambers of the shell, had paid attention to all the cases port to the ventricle of the neart, leans immediately after-that had come under his observation of the formation of wards on the superior and posterior surface of the muscle, chambers in shells, by the secretion, on the part of the and turns on itself to terminate posteriorly in a floating animal, of a nacreous layer, forming a new basis of support anus, which is easily perceptible in the posterior commis- to the soft parts, and cutting off the deserted portion of the sure of the mantle. At the anterior part of the animal, and shell from ihe chamber of occupation. He laid the followtowards the middle of the abdominal mass, a singular organ ing observations on the structure of the Water-clam (Sponis found ; it is composed of a disc supported by a short pe- dylus varius, Brod.) before a meeting of the Zoological dicle; from the centre of this disc a small cylindrical ten-Society of London, in June, 1837, and he observes that it is don, terminated by a small oviform fleshy mass, elevates well known that the process above adverted to is not the itself. We see, remarks M. Deshayes, in this peculiar only mode adopted to suit the shell to the changing forma apparatus, a modification of the locomotive organ, the and bulk, or other exigencies of its occupant. Taking the foot, become here useless for changing the place of the genus Magilus, for one example, the Professor remarks animal, because it invariably and immediately fixes its that the part of the shell from which the body gradually shell on rocks or other solid bodies constantly bathed by recedes is filled up by the continuous compact accretion of the sea. The branchiæ resemble those of the Pectens ; calcareous matter, and a solid massive elongated shell is they are large, equal, and crescent-shaped. The heart is thus produced, which would be a great incumbrance to a symmetrical; a single ventricle embraces the intestine at locomotive mollusk, but is of no inconvenience to a uniralre destined by nature to live buried in a mass of lithophytous, but to the preceding and succeeding septum at the part coral,

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occupied by the adductor muscle, and for an extent correAgain, in Helix decollata, he observes, the deserted part sponding to its circumference. The progressive change in of the shell, after being partitioned off by the nacreous the position of this muscle by the absorption of the posterior layer secreted by the posterior part of the mantle, is broken fibres and the addition of others anteriorly, changes in a away by some yet unexplained process, and, consequently, corresponding degree the relative position of these subcenno chamber nor any solid apex of the shell remains. tral confluent parts of the septa, and a beautiful undulated

But, continues the Professor, the retention of the deserted disposition of the whole chambered part is the result. If chambers, and the interception of certain spaces of the the adductor muscle were a tube instead of a solid mass, shell by calcareous šepta, though not unknown in the gas- the central contiuent part of the septa would of course be tropodous univalves, is more common in bivalves; and he perforated, and a sipbon would result, the calcareous walls adduces the case of a common oyster, which, if kept without of which, from the proximity of the chambers, would no food, will frequently expend its last energies in secreting a doubt be continuous, as in many Polythalamous shells. new nacreous layer, at a distance from the old internal sur- The same author notices the disposition to form chambers face of the concave valve, corresponding to the diminution manifested, but in a much less degree, in the smaller flatof bulk which it has experienced during its fast, and thus tened or superior valve of the species under consideration. adapt its inflexible outward case to its shrunken body. In the specimen which formed the subject of his paper

Then he instances the calcareous tube exuded from the there were three chambers, with narrower intervals and elongated mantle of Lamarck's Septariæ, in which the much thicker partitions than in the lower valve. These closed extremity is divided into chambers by a succession partitions were confluent opposite to the muscular impresof layers at a distance of half an inch from each other, sion, as in the lower valve, and each partition expanded from having a regular concavity towards the open extremity of this attachment in an infundibular manner, which reminds the shell. These concave septa are, he observes, composed the observer of the emboitement of the calcareous part of entirely of the nacreous constituent of the shell: in one

ne the siphon in the Spirula. specimen which he examined they were six in number; “The secreting power of the lower lobe of the mantle in and he adds that they are thin, smooth, and closely resem- the Spondylus,' says Professor Owen in continuation, ‘is bling the partitions in the Nautilus and SPIRULA, save in greater than in the upper; and the layers of nacre which the absence of the siphonic perforation.

are successively deposited on the cardinal margin push forReturning to the bivalves, Professor Owen points out the ward in a corresponding degree the upper valve, leaving a fact that among them the Ostreæ not unfrequently present heel or umbo behind the hinge of the lower valve, which, shallow and irregular chambers in the substance of the from the inactivity of the secreting surface of the upper shell, and that the Etheriæ have vesicular cavities inter- lobe of the mantle, is not opposed by a corresponding umbo posed between the testaceous laminæ; but he states that in the upper valve. the most constant and remarkable example of the came- * The laminæ, which are deposited in a continuous series rated structure of the shell is presented by the large Spon- of superimposed layers at the hinge of the lower valve, are dylus or Wuter-Clam above named, so called froin ihe fluid not continued in a like state of superposition throughout; which (until lost by slow evaporation) occupies the cham- they soon separate from each other, and do not again unite, bers, and which is visible in the last-formed chamber through except at the space corresponding to the adductor muscle, the ihin semi-transparent exposed septum.

and at the circumference of the valve. We possessed several fine examples of this species, and • The interspaces of these succcessive layers of the growit was only in advanced stages of growth that the water ing Spondylus cannot, from the absence of a medium of was included. Young shells were entirely without it. The intercommunication, serve any purpose hydrostatically with old shells, some of which were of great size, were copiously reference to locomotion : it is a singular fact indeed that the supplied. The water could be seen through the semi. Spondylus, in which the chambered structure is constant, transparent floor or septum on which the animal reposed in and the Ostreæ and other bivalves, in which it is occasional, the lower valve, and through the thin ceiling, so to speak, are cemented to extraneous bodies by the outer surface of of the upper valve. As the shell was turned in the hand, the shell, generally by the concave valve. So that the septa the tluid could be observed through these transparent lari: must be regarded as mere dermal exuviæ still left adhering næ finding its level with air-bubbles at its surface, and to the animal, to which, as a motionless bivalve, they are no could be heard as it trickled to that level. But to return incumbrance. It is highly probable that all the chambers to the Professor's interesting memoir.

are originally filled with fluid, as more or less is found in In order to examine this camerated structure, and more the outer ones of the specimens brought to this country. especially to see how it was modified by the presence and 'In the Testaceous Cephalopods a new structure is added, progressive change of place of the adductor muscle, he had | viz. the siphon, whereby the exuvial layers of the old shell a fine specimen sawn through vertically and lengthwise: it and the deserted chambers are converted into a hydrostatic measured eight inches in length; the substance of the con- instrument, subservient to the locomotion of the animal. cave valve, which was two inches and one-third in thickness The operation of the siphon and chambers has been ably at the thickest part, included fourteen chambers, separated explained by Dr. Buckland in the Nautilus, where the calfrom each other by very regularly formed and stout parti- careous inflexible tube protecting the membranous siphon tions, composed, as in other chambered shells, of the nacre- is not continuous. The working of the siphon is however ous portion or constituent of the shell., The septa were less intelligible in those species in which the outer calcareous slighily undulating in their course, but presented a general tube is continued from chamber to chamber, as in the Spiconcavity towards the outlet of the shell. Not any of these ruiæ, Orthoceratites, &c.; and it is with respect to came. partitions were however continued freely across the shell, rated shells of this kind that I would ask how far the reasonbut each became continuous at the muscular impression, ing suggested by the chambers in the Water-Spondylus which is near the middle of the shell, with the contiguous may be applicable in their case, and whether a final iniensepta. In general also the septa commenced singly from tion can be clearly traced beyond the diminution of specific The cardinal or upper wall of the valve, and divided into gravity occasioned by a large proportion of the shell being two when about one fourth of the way towards the opposite converted into receptacles of gas; if indeed we have suffior lower wall; the thickness of the undivided part of the cient evidence to assume that they do not contain a denser septum being equal to, or greater than, that of the two di- tluid, like the Spondylus.' visions of layers into which it splits.

The cut represents a section of a very old individual of Professor Owen accounts for the fact of the septa be this species, in which the upper valve was very convex, and coming united together at the point of insertion of the furnished with a great number of septa. adductor as follows:-The muscle never quits its attach- The fluid contained in the specimen exhibited by Mr. ment to the valves; while the lobe of the mantle, except in Owen, which is in the Museum of the College of Surgeons its circumference, and where it is attached to the adductor in London, was put into the hands of Dr. Bostock for examuscle, must detach itself from the surface of the valve mination by him, and the Doctor obtained the following whieh is about to be partitioned off, when it secretes upon results :the interposed fluid the new septum or basis of support. It was turbid, had an acid saline taste, and a rank disIt is obvious therefore, he observes, from the condition agreeable odour. After standing for twenty-four hours, it under which the partitions are successively secreted, that deposited a whitish curdy sediment, and became clear and they must adhere not only to the circumference of the valve,'transparent. The clear tiuid, amounting to 54 m., was

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Scania and Maestricht, and the second (Plagrostoma spinssum, Sow., from that of England, Gerinany, and France.

The number of fossil species of Plicatula noted by M. Desliayes as being found in the tertiary beds is seven. In the last edition of Lamarck the number recorded is ten : the locality giren to one there described (Plicatula pectinoides) is the lias of France, Germany, and England. Mr. Lea notices another (Plicatula Mantellii) from the Claiborne beds (tertiary).

Dr. Mantell records two (Plicatulæ inflata and peclinodes) from the chalk marl, Sussex.

Dr. Fitton notes the same two species from the gault and

lower green-sand, and an uncertain species from ihe PortSection of Water-Spondylas cut longitudinally thmugh both vulves, which

land stone (Dorset, Bucks), and the Oxford oolite (Cam.). are represented as closed.

Professor Sedgwick and Mr. Murchison record Plicatuia poured from the sediment, and was subjected to various asperu from the Gosau deposits, and its equivalents in the tests. It was neither acid nor alkaline ; it produced a very Alps. copious precipitate with the nitrate of silver, indicating the Of the other so-called genera belonging to this family, presence of a large proportion of muriatic acid; the muriate Dr. Mantell gives Plugiostomata spinosum, Hoperi, and of barytes indicated a slight trace of sulphuric acid; while Brightoniense, as found in the Sussex chalk-formation, and the appropriate tests of lime, magnesia, and iodine produced Dianchoræ lata and obliqua, from the same locality ; Plano effect." A portion of the fluid was evaporated by a gentle giostomata elongatum and asperum from the chalk-marl, heat, when a quantity of crystals of the muriate of soda was and an unnamed Plagiostoma from the firestone or upper obtained, amounting in weight to very nearly twenty per green-sand. Mr. Lonsdale enumerates Plagiostomata gicent, of the fluid. After the removal of the crystals, a little ganteum, punctatum, duplicatum, and Hermanni, from ihe brown matter was left in the capsule, but in too minute a Bath lias, and unnamed Plugiostomata from the inferior quantity to enable Dr. Bostock io ascertain its nature and oolite, the great volite, and the Forest marble of the same properties, except that it was not soluble in alcohol: we district; that from the Forest marble with a ? Professor may however, he observes, presume that it gave the fluid its Phillips records Plagiostoma giganteum, from the inferior peculiar flavour and odour. It appeared then that the colite and lias; Pl. rusticum, from the lias and coralline fluid in question consisted almost entirely of a solution of oolite ; pectinoïdium, from the upper lias; læviusculum and pure muriate of soda, differing therefore in its chemical rigidum, from the coralline oolite; rigidulum, from the constitution from sea-water. The sediment above mentioned cornbrash; one from the Oxford clay; cardiiforme ? one appeared to consist of small globular, or rather, pyriforin from the Bath oolite; duplicatum, from the coralline oolite, bodies, probably of an organic origin. (Zool. Proc.)

Oxford clay, and Kelloway's rock; and interstinctum, from Geographical Distribution, &c. of the Genus.-- Spondylus the cornbrash and Bath oolite. 'Also Dianchoru striata, has been found attached to rocks, corals, other shells, from the chalk. (Organic Remains, Yorkshire Coast.) &c., at depths varying from the surface to seventeen Dr. Fitton's list includes Plagiostomata cardiiforme, fathoms in the seas of warm and temperate climates (the elongatum, Hoperi ? rigidum, obliquatum, rusticum, and a Mediterranean for instance). The finest and most beautiful small species ; and Podopsis striatus (Dianchɔra striata). species are natives of tropical and intertropical localities.

(Strata below the Chalk.) The number of recent species recorded by M. Deshayes The number of Plagiostomata given in the last edition of in his tables is 25. Of these, Sp. gæderopus is noted as Lamarck, exclusive of Pl. spinosum, noticed above, is six. recent and fossil (tertiary). The number given in the last The number of Podopsides stated in the same work, excluedition of Lamarck is 21; but this does not include Spon- sive of Pod. truncata, noticed above, is one, viz. Podopsis dylus varius, nor four other species brought home by Mr. gryphoïdes, and M. Deshayes expresses his opinion ihat Cuming, and described by Mr. Broderip. (Zool. Proc., Syn- Lamarck founded this species on a variety of Osirea vesicuopsis Testaceorum.)

laris ; at all events, he says, M. Goldfuss is wrong when he Plicatula.

refers this shell to Brocchi's Ostrea navicularis ; inis Shell inequivalve, inauriculate, narrowed towarus its species, he adds, peculiar to the Subapennine beds, bas base; the upper border rounded, subplicated ; with unequal never been found at Meudon. umbones, and without external facets. Hinge with two SPONDY'LUS. [SPONDYLIDÆ.) strong teeth in each valve. A fosset between the cardinal

SPO'NGIA, the generic name under which Linnæus teeth, receiving the ligament, which is entirely internal. and many subsequent systematists have ranked the very Lamarck.)

numerous forms of organization analogous to the sponges of commerce. Generally, and we think justly, zoologists have claimed these organizations for the animal kingdom, and ranked them among the zoophyta ; but there are emnent writers who dissent from this view on different grounds, and prefer to rank the marine and freshwater sponges wil plants. That the animal and vegetable organizations both terminate obscurely toward the inorganic structures of creation, and that in this approach to iheir common boundary they touch and melt into each other al more than one point, are propositions which, for the purpose of the present argument, and in the actual condition of natural history, seem to

require no proof; but much of the difficulty which is admitted Shell of Plicatula. a, hinge of upper valve.

or supposed to attend an exact determination of the animal Geographicol Distribution. The seas of warm climates, or vegetable nature of certain stony corals (Nullipora, where it has been found adhering to stones, shells, and Lamarck), Spongiadæ, Corallinadæ, &c. arises from a want other submarine bodies, at depths varying from four to of recollection and application of these truths. If the boun. eleven fathoms.

daries between the animal and vegetable creations be inas M. Deshayes, in his tables, makes the number of recent finite, this must happen because ihe structures and funcspecies five, and the same number is recorded in the last tions to which these terms are rightly applied insensibly pass edition of Lamarck.

into and inix with each other, so as to render definition imFossil SPONDYLIDÆ.

practicable by single diagnostic characteristics, and difficult The fossils of this family are very numerous, and have a even by a careful summation of analogies and differences. somewhat wide geological distribution. The number of When iherefore zoologists define animal life to be characspecies of Spondylus found in the :ertiary beds is stated in terized by locomotion, by sensation, or by irritability; or by the tables of M Deshayes to be nine, the same as that in a certain chemical constitution; or by certain orders of the last edition of Lamarck; but two of these last (Sp. structures, as an internal digestive cavity, a nervous system, Niissoni and Sp. spinosus) are stated to be from the chalk : and the like, -it is not to be wondered ibai whole groups of the tirst (which is Podopers truncata, Nils.) from that of I undoubted animals are excluded by this inadequate method

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from all place in the real system of nature, and thrown into | transparent globules, connects the different parts of the an appendix. But if, on the other hand, we recognise and skeleton, lines the various canals, and forms the margins of act upon the principle that life manifests itself on the globe the openings. The pores are minute openings (on the surin a variety of aspects no otherwise limited than by certain face) with a gelatinous margin, strengihened or defended general conditions, and by special adaptation to peculiar exi- by the skeleton or spicula, into which the water enters in gencies, then it will follow that all organic structures will currents, generated probably by a ciliary apparatus, which be grouped round particular types, according to the number however has not yet been detected by the microscope. The and importance of their agreements; these types, treated as water, after traversing the interior canals, is ejected by single objects, will admit of similar arrangements; and a means of orifices which are larger than the pores, and in general classification may result, approaching to a really many species are elevated above the surface in the form o. * natural system,' and justifiable on the basis of the induc- perforated papillæ. The Ovu are numerous, at first appeartive philosophy.' (SARCOIDEA.)

ing like groups of minute, irregularly shaped, opaque The pervading idea which connects together the members granules, derived from the gelatinous matter, which unite of each group round one central type, is a community of into ovate bodies, falling at maturity into the canals, and are structure and functions, and the place of a group among expelled by the orifices. These ova float in the water, and the other types of animal or vegetable life will be found by exhibit spontaneous motion by the rapid action of the ciliæ, the analogies which, in respect of these structures and func- which cover the anterior portion of the body, and at length tions, it presents with other groups.

attach themselves and then expand into the forms of maConsidered in this manner, sponges, thou they may

turity. The currents from the orifices are best examined not, as Aristotle reports, ever exhibit a shrinking movement by placing the recent animal in a shallow dish of water, (xivnou) when touched-though no polypi and no real and throwing a little powdered chalk on the surface, the digestive cavities are recognised in them, must surely be motion of which will indicate the direction of the streams. admitted among the zoophyta. For in regard to their con For the purpose of examining the skeleton, it is requisite stituent structure, they are composed, as so many of the Poly- to macerate the sponge in hot water, which removes the piaria are, of a firm horny or stony skeleton, immersed in a gelatinous matter, and leaves the skeleton in a state fit to sost gelatinous living mass; in respect of the aspect of be examined under a microscope. When the spicula are these two substances, the resemblance which they offer to siliceous, the animal matter may be removed by nitric acid, Alcyonia appears very strong, while their external forms, or by combustion, as was practised by Müller (Zool. Dan. uncommonly varied, sometimes resemble Alcyonia, often ap t. 85), when the vitreous needles will appear unaltered.' proach to Palmipora, frequently to Pavonia, Agaricia, and The gelatinous substance of sponges is scarcely capable other forms of Lamelliferous Zoophyta. The currents of of conservation. It is usually of a ropy consistence, sliding off water which pass through the canals of their substance are from the skeleton, or else pressed off by the divers for sponge. analogous to many operations among Polypiaria and Mol- It is of various colours, but commonly fawn coloured or lusca, and perhaps depend on similar ciliary organs, though, orange coloured; in this respect resembling the gelatinous except on the young ora of sponges, they have not yet been parts of Polypiaria. detected. As however they contain no Polypi, it is difficult Horny sponges with anastomosing fibres, fit for domestic to rank them under the Polypiaria. Dr. Johnson omits, in use, belong mostly to warm zones of the sea; sponges with his excellent work on British Zoophyta, the sponges, and calcareous spicula are rather numerous on the British coasts; the following summary of his reasons deserves attention: and siliceous spicula are common in the sponges of most • If they are not the productions of Pulypes, the zoologist latitudes. [SPONGIADÆ.) Remains of both horny and spicuwho retains them in his province must contend that they lar sponges occur in a fossil state. are individually animals, an opinion to which I cannot assent, SPO'NGIA, MEDICAL USES OF. The use of sponge seeing that they have no animal structure or individual | by surgeons, in its natural state, to absorb fluids, needs no organs, and exhibit no one function usually supposed to be notice, but it is also employed by them under the name of characteristic of the animal kingdom. Like vegetables, they sponge tent, when prepared in a particular manner. This are permanently fixed; like vegetables, they are non-irri- consists in dipping the sponge in melted wax, and comtable; their movements, like those of vegetables, are extrinsi. pressing it between iron plates till it hardens on cooling; it cal and involuntary; iheir nutriment is elaborated in no is then cut into cylindrical or other forms. The pieces are appropriated digestive sac; and, like cryptogamous vegetables

introduced into sinuses and other narrow canals, with the or algæ, they usually grow and ramify in forms determined intention of dilating them by the expansion of the sponge, by local circumstances, and if they present some peculiari- when the wax melts by the heat of the part. Sponge tents ties in the mode of the imbibition of their food, and in their are however little used by modern surgeons. secretions, yet even in these they evince a nearer affinity to According to the analysis of Hornemann, sponge consists plants than to any animal whatever.' On this we may of a substance similar to osmazome, animal mucus, fat oil, remark, that very many animals are as permanently fixed a substance soluble in water, a substance only soluble in as sponges; that irritability is not to be looked for in every potash, and traces of chloride of sodium, iodine, sulphur, part of a sponge, any more than in a Rhizostoma, whose phosphate of lime (?), silica, alumina, and magnesia. divided digestive cavities are very unlike ordinary stomachs; When sponge has been cut into pieces, beaten in order to and that the forms of sponges include remarkable analogies free it from little stones and shells, and burnt in a closed with the supports of Polypi.

iron vessel, till it is black and friable, it is then called burnt It is to our countrymen Ellis and Dr. Grant that the sponge (spongia usta), and has in 1000 parts the following history of sponges is most indebted. The former established composition, according to Preuss :—343 parts are destroyed the existence and nature of the currents of water which pass by heat; the remaining parts are-carbon and siliceous inthrough the substance; and the latter, besides confirming soluble matters, 327; chloride of sodium, 112; sulphate the results of Ellis, added a vast quantity of new and valu- of lime, 16; iodide of sodium, 21; bromide of magneable observations. Mr. Bowerbank has contributed precise sium, 7; carbonate of lime, 103; magnesia, 4; protoxide ‘nformation regarding both the fossil and recent spo ges.

of iron, 28, and phosphate of lime, 35. As the virtues of Ellis, On Corallines; Grant, 'On Sponges,’ in Edinburgh this greatly depend on the proportion of iodine, much of Phil. Journal; Bowerbank, Geol. Proc., 1840; and Micros. which is volatilized by the high temperature required to Journ., 1841.)

calcine the sponge, it has been proposed only to expose it to Sponges are thus characterized, in accordance with the such a heat as will thoroughly dry, and colour it brown, and researches of Ellis and Grant, by Dr. Fleming (British Ani- render it friable, when it may be powdered, and preserved in mals, p. 518): ‘Sponges consist of an albuminous skeleton well-closed bottles. For use it is generally formed into an and gelatinous matter, forming a mass not irritable, with electuary or into lozenges. A test of its goodness consists in numerous holes, connected internally with anastamosing heating it in a glass flask with sulphuric acid, and if copious canals. The skeleton is either simple, consisting of horny violet-coloured fumes be evolved, this proves that it contains fibres, as the species so commonly used for domestic pur- much iodine. Burnt sponge has been almost completely poses; or compound, being strengthened by calcareous or superseded in the treatment of bronchocele and scrophula siliceous spicula.* The gelatinous matter, abounding in by iodine and its preparations; but as it obviously consists Some of the skeletons of sponges are (perhaps) entirely horny: others, as

of a natural combination of many of the principles which in a heatiful specimen from the West Indies which M. Stuichbury has shown have been deemed useful in scrophula, it ought not to be us al Bristol, are entirely siliceous ; possibly some are entirely calcareous but hastily discarded. the greater number are compound, and consist of horny matier with additions

It is with great propriety retained in 'spicula in various propurtions.

the Dublin Pharmacopeia.

SPO'NGIADÆ. Regarding sponges as A polypiserous Examples, Spongilla fluviatilis, Linn.: Spongilla lacus. Zoophyta, composed of flexible or rigid skeletons enveloped tris, Lin. in a gelatinous mass, productive of inward currents through For the animal nature of these fresh-water sponges the small surface pores, and outward currents through continuo argument is less complete than for the marine tribes. By ous canals, we may proceed to analyse the large group of experiments as to the effect of light on them, Mr. John Hogg organic forms possessing these characters, by the nature (Linn. Trans.) has endeavoured to show that they are inand arrangement of the skeleton, for the gelatinous part fluenced by this agent in the same manner as plants are, (though perhaps conservable, if due care be used) is not and that their green colour depends upon exposure to it. probably capable of being examined so as to furnish dis- Groups depending on Characters of Surfuce or general tinctive and recognisable characters.

Figure. Dr. Grant pointed out the principles of this analysis, by Geodia, Lamarck.- Mass fleshy, tuberous, irregular, bolhis observations on the nature and arrangement of the horny low within, externally incrusted by a porous envelope, which fibres, the calcareous and silicious spicula, and the forma- bears a series of orifices in a small tubercular space. lion and distribution of the pores and orifices of sponges. Example, Geodia gibberosa, Schweigger. (Blainville, Dr. Fleming (British Animals) gives the following genera, Actinologie, pl. 91, fig. 4.) under the family of Spongiadæ :-Tethya, Halichondria Coelopiychium, Goldfuss.--Mass fixed, pedicled, the up(including Spongilla of Lamarck), Spongia, Grantia. (Si- per part expanded, agariciform, concave, and radiato-porose phonia, Choanites, and Ventriculites of Parkinson and above, tlat and radialo-sulcate below. Substance fibrous. Mantell are included in Halichondria.)

Example, Coeloptychium agaricioideum, Goldfuss. (PeBlainville (Actinologie) arranges under the head of trefactenkunde, pl. 9, fig. 20, a-e.) Amorphozoa Alcyonellum, Spongia, Calcispongi From the chalk of Westpinalia. (Grantia, Fleming), Halispongia, Spongilla (Ephidatia, Siphonia, Parkinson.-Mass polymorphous, free or fixed, Lamouroux), Geodia, Cæloptychium (fossil), Siphonia, Myr- ramose or simple, concave or fistulous above, porous at the mecium (fossil), Scyphia, Eudea (fossil), Halirrhoa (fossil), surface, and penetrated by anastomosing canals, which terHippalimus (fossil), Cnemidium (fossil), Lymnorea (fossil), minate in subradiating orifices within the cup. Chenendopora (fossil), Tragos (fossil), Manon (fossil), lerea Example, living, Siphonia typum. (Blainville, Actinologie, (fossil), Tethium.

pl. 95, fig. 1.) Sicily. Very few of these genera, adopted from Schweigger, Example, fossil, s. pyriformis, Goldfuss. (Petrefactenk., Goldfuss, and others, can be considered as at all sufficiently tab. 6, fig. 7, a, b, c, d, e.) cletermined, because the constituent structures of the fossil Siphoniw abound in the green-sand formation. masses, on which alone they can be justly founded, have, in Myrmecium, Goldfuss.-Mass subglobular, sessile, of a most cases, been altogether left unexamined. When the close fibrous texture, forming ramified canals which ramodern achromatic microscope shall have been directed diate from the base to the circumference; summit with a upon them, with such perseverance as Mr. Bowerbank central pit. (Proceedings of Geol. Soc., 1840) has employed on the Example, Myrmecium hemisphericum, Goldfuss. (Pespicular structures of the sponges imbedded in or constitut-tref., tab. 6.) ing the nodules of flint in chalk, so that the forms of the Seyphia, Oken.--Mass cylindrical, simple, or branched, anastomosing fibres or stiffening spicula, the sections and fistulous, ending in a large rounded pit, and composed endistribution of the canals, &c., can be certainly defined, a tirely of a reticulated (firm) tissue. great benefit will arise to this branch of zoology, and an Example, living, S. fistularis, Esper. (Tab. 20, fig. 2.) equal advantage for geology.

Example, fossil, S. mammillaris, Goldf. (Petref., tab. Groups of which the Constituent Structure is known. 2, fig. 1.)

SPONGIA.—Mass soft, elastic, more or less irregular in Eudea, Lamouroux.—Mass filiform, attenuated, subshape, very porous, traversed by many tortuous canals which pedicellated at one end, the other enlarged, rounded, withi terminate at the surface in distinct orifices. Substance of a large terminal pit; surface reticulated by irregular lacunæ, the skeleton, cartilaginous fibres anastomosed in all direc- minutely porous. tions, without any earthy spicula.

Example, Eudea clavata, Lamouroux. (Gen. des Polup, Example, Spongia communis. (Blainville's Actinologie, tab. 74, fig. 1-4.) pl. 93, fig. 3.)

Halirrhoa, Lamouroux. Mass turbinated, nearly regular, Calcispongia, Blainville (Grantia, Fleming; Luchelia, circular, or lobale; surface porous; a large central pit on Grant) --Mass rigid, or slightly elastic; of irregular form, the upper face. porous, traversed by irregular canals, which terminate on the Example, Halirrhoa costata, Lumouroux. (Gen. des surface in distinct orifices. Substance of the skeleton Polyp., pl. 78, fig. 1.) cartilaginous fibres, strengthened by calcareous spicula. From the oolite of Caen. The spicula are seldom simple, often triradiate in figure. HippalimusLumouroux.-Mass fungiform, pedicel

Example, Calispongia compressa. (Montague, in Wern. lated below, conically expanded with a central pit above; Trans., vol. ii., pl. 12.)

surface porose, and irregularly excavated. Altogether Fleming and Blainville admit five species of Example, Hippalimus fungoides, Lamouroux. (Gen. des this genus as determined. . They occur on the British and Polyp., pl. 79, fig. 1.) other northern shores.

From the oolite of Caen. Halispongia, Blainville (Halichondria, Fleming).- Mass Cnemidium, Goldfuss. – Mass turbinated, sessile, commore or less rigid or friable, irregular, porous, traversed by posed of close fibres and horizontal canals, diverging from tortuous irregular canals, which terminate at ihe surface in ihe centre to the circumference; a central pit on the upper distinct orifices. Substance cartilaginous, fibres strength surface, cariose in the exterior, and radiated at the mar. ened by silicious (generally fusiform or cylindrical) spicula. gins.

Example, Halispongia papillaris, Grant. (New Edinb. Example, Cnemidium lamellosum, Goldf. (Petref., tab. Journal, vol. ii., tab. 11, f. 21.)

6, fig. 1.) Blainville admits fourteen species. Fleming, who in- Lymnorea, Lamouroux.—Masses mammellated, finely cludes in it the fresh-water spongilla (Ephydatia, La- porous and reticulated, agglomerated within a common mouroux), counts eighteen species. In what manner the calyciform wrinkled adherent base. immense number of species of sponges mentioned by Èxample, Lymnorea mammillosa, Lamouroux. (Geu Montague and Lamarck are to be distributed among these des Polyp., tab. 79, fig. 2.) three groups, which ought to be considered families rather From the oolite of Caen. than genera, does not appear.

Chenendopora, Larnouroux.-Mass conical, infundibuThe remarkable silicious sponge which has been before liform, external surface sulcated across, internal face alluded to [SPONGIA) as under examination by Mr. Stutch-porose. bury of Bristol, would appear justly entitled to constitute Example, Chenendopora fungiformis, Lamouroux. (Gir. a new genus, if, as we suppose, it is in no manner dependent des Polyp., pl. 75, fig. 10.) for its figure on a cartilaginous skeleton, but is really and From the oolite of Caen. entirely a silicious mass, supporting a gelatinous envelope. Tragos, Schweigger.- Mass composed of dense, close,

Spongilla, Lamarck and Blainville (Ephydatia, Lamou- coalescing fibres ; surface covered by distinct scatiered rou:c).—Mass more or less rigid or friable, irregular, porous, orifices. but not furnished with regular orifices to internal canals. Example, Tragos difforme, Goldfuss. (Petref., tab. 3, fig. 3.)

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