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I is,ellanown to ver intelligent Oologist, that there are many animaisamongst the inferior Orders the invertebrata so imperfecti undet stood, a tocreate a Wish sor more complete de talis Dona suci naturalistias may be ortunate enough to have the opportunit os gratisyinis laudabie a destres of this description is the Genus,hicli constitutes the subject of the present memoir, than Whicli, non has been es understood more the subjectis dispute, or of Whicli a diae knowledge could e more acceptable to thematural Historian the Geologist, o the Philosopher bellico intense interest in a doubi potnt of vieW, vi g. Ist. becauserit appears to belonito the existin irace of animais,hichieopte the
Thai, should have rematne ignorant of the reat nature of these curious and beautilat animaliuntii the present time, is to e impute to the ver se specimen os the ni known recent species that have been alienis to their having been invariabi broken orabove their attachmento ille octis to thei nothnving been submitte 1 to any competent naturalis in their livinistate, an totheir having been sent to Europe ac fried specimens mad any of them been senthoni si om thei native site the est In dies preserved in spiriis, his memoirWould orat have ad forciis objeci, to Oint ut a ne species, an no the
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higherisim, o demonstratin ille remarii te peculiarities in structure os the Crinoidea, as the famil has been anted by r. illar, in his late ver elaborate an valvabie monograph on his tribe of animais. I we alio a stigii vie of the variet os opinion Whicli these animal have give riserio , find that Lister, Ray, and others, considered them asielongingto the vegetable Lingdonici innaeus regarded them a corias 'alch, Lamarch, Ac as De polypiferous animuis craWlinio the bottoni of the ocean, an hen cerelatexto the Pennatulaeci hos Who have most early approximate the truth, belleved them to e stipitate animais, attached by thei stem to the roclis, and 1nore nearly relate to the Asteriaco Star-sisl, of this number, are Parkinson, Cuvier, Latreille, and more particularly r. illar, in the work above alluded to. To reconcile opinion froni such authoritie so opposed to each other, and obanish conjecture, it must appea strange thatio person e denuo ured durinisolonia perio as upWard of halna centurnio acquire a persect knowledge of the animal by a direct search in thos places Dom Wheno the were si si obtainem: There cun Scarcet be a doub but success,ould attent an attemptis this Lindproperi made, a litile oulside the ordinar anchorage round in in os of the Vest Indiacistantis, froin Whenc the might e sent home reserve in eali spiriis, o a nearly Saturate Solutionis sest for the inspectionis the curious
The est Indian specios, Pentacrinus Caput edusae and that whichris the subjectis the present emuir are the oni existinis pecies it herio discovered therars of these, is an animal o considerable sige, iiij intemstem thicher thana wan's quill risinito the height of severa Dei, and the sprea oscit arms hein te quant a Spana the lalterin the contrary, is probabi the smalles of the tribe, no exceedini vhen fuit grown three quarters of an incli in eight undstender in proportion cit is from his circumstance no doubi that it has itherto escaped the prying eyes of Our more industrious domestic aturalisis This paucit o livin species, oes no exteti to the Ossi Crinoidea, Whicli present great variet y, O OnI o species, ut o genera, foris distincta noWIedge of Whicli e re principali indebie to the comprehensive an luminous OnO- graph of Μr. Millar.
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The animal unde consideration urnis hes the ollowing resulis, vi g. Ist, Thati is a stipitate asterias, most early relate Dio Comatula ; elevate by a calcareo us articulate stem, permanenti attached i iis basis, an supporting the stellat arm and Od of the animalis it apex. 2ndly, That the aruis havethei principat ramis cations likeWis compoSed os calcareous Oinis, and supporta doubie ro os flesii tentacula ali long thei itiner fides. 3dly, That thehod of the animal, is notis simpleius has been supposed, but is provide With a distinc central pening so the mouit, an another latera onerior the anus. 4thly, That the arnas are the las par of the animal evolved graduali extend-ing and ramisyinisi om heir apices. In proceedinito describe the animal more a large no us Willi made of the termS, vertebrae, ibS, intercostais, scapula, andS, singers, c. alien froni themore perfeci or vertebrate animais, and as emplοyed by Pari inson, illar, &c. becauserit is presumed that the us os suci term must Iead O erroneous ideas of their nature and structure indeexit ma be laid οWias a genera rute, that ternas alien Doni the vertebrate animais, an neverte u8tly or,ith an propriet applied to the paris of the invertebrated animias, and more particulari tolli inserior orders, as of Μollusca Radiata, Vermes,inc Where dissection politis out a similarit of structure, and an internalion Sheleton filiosphate of time. a in the Classes, animalia, ves, Amphibia, in the relationis the paris is more or les obvious, and the analog seldom dissiculto traces even in the Insecta und Crustacea soni se potnts of analog may Stili e perceived butwhen, descend further in the scale of being although thei se of some of theirparis may be thus conjectured, ut analog in structure, an in the relation ofparis entiret di sappears. In the folloWin description heres Ore, very thingwilli embrace unde the eadf, I, Basii 2, edicles 3, Auxiliar sidearms-4 PeriSome 5 Arms i, Tentacula I BOdy. This nempentacrinus, Psini to correspond With the character assigned to the
soli fabri of this genus by r. illar, illi the exception perhaps, of the pedicte, hicli is o fine, a to rende it dissicultri pronounc acto iis bella groundi angulari is it is reali os the forme shape, Whicli is probabie, it Would
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rende necessar an amen de character of the genus, o the significatio of the generi titi tot modissed η his variation in the figure of the stem, having been observestrio occur in the genera Cyathocrinites, and lalycrinites, it Would appea tot a circumstance of to trival a nature t enter into the generi distatinction the fame may be observed of the cavit Within the stem, erroneouslycalled the alimentar canal iis eing round o pentangular constituting theoni disseretice belween r. illar' genera Ofractinocrinites an Rhodocrinites. Tho Basis by whicli the anima is perinynenti fixe to various species os Coralines, consist of an expanded an stighil convex calcareous dis o fhield, of a round or ovat sh ape, closely applied by the whole of iis unde sursace to thobodies on Whicli it grows, and sen dira Out froni a depressionis pit in the midd loo iis uppe sursace the pedici or stem. In One instance, a single disti Nas ob serve to ive origin to No siems, probabi regultin frontob union of two originali separate embryos This basis ould appea to e that par of the animal whicli sirs develope and persected. The Pediole or Stem is nearly sili rin, ein but lighil incrassated toWardsits upper en&; it is composed of a variable number of oinis, about 24 in ull-grown specimens Whicli are horter as the approach it uppe part ianti theypresent the appearance of mere ring or plates immediatet aluining theiodyof the animal so that it is here, probably that the succession Particulations aresorme Whicli ad to the enoreasing tength of the stem, as the animal advarices in iis growth that the oints areiso allis formedio ever, is evident, rom the principa par of the divisio iis of the sternaeing distinguishabie, Wben the wholes animal is stili os a gelatinous consistence. The hole of the stem, is investeubna continuous delicate membrane, as indeed, are ut the SSeous part of tho animal, Whichiind them together, an furnisbes the requisit Supportu themuscular System, hicli thei motion leadi t Suppos the must necessarilypossess, and whicli is probabi no other, than What present itSel unde the aptapearance of a gelatinous, translucent substance, interpoSed belWeen his interio membrane and the ossicula. Whether the stem of this species is provide withan interna centra canal, has no been determined, but ascit an no longerie
Nomina generica contraria Speciei alicui sui generis mala sunt. iiiin Crit Bot.
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considere a the intestina cana in hos species in Whicli it is evident, it will probabi be soland calculate to conventhe requisite nourishmen to the internalpar of the stem, anxio ive the necessur Space or an interna muscular layer; thus Pari inson speaking of the entaurinus Caput-Μedusae, says that this cavlty ,ould appea tote illed by a membraneous, nervous OritamentOuctissue. The animal possesses the power of bendinior inclining the stem Deel in very direction, and What is more remat Labie, O tWistiniit, into a stior spirat, and that with a considerable degre o vivacity, a Lin os movenient that has notbeen notice excepi in the Vorticellae. Auriliary Side Arms: In his species there istut a single row of these Whicharis Doni the fides of the uppermost oint of the stem, aridore place opposite to the arnis of the animal; ach of them is compose of about 0cioinis, theterminal one ein forme into a Lind of hook, these When erect is asaighas the bifurcationis the arnis, and froin the anne in hicli themare j inteliogether are incapable of any other motion than ibat of rolliniin Wards, oriatherdownward cupon themselves, o in Bolanical language thesare revolute, by whichmeans, and their Ooked extremi ty the can servem Other purpose, than thato fixing theiod of the animal by coitin themselves around the corallines,&c amongst,hicli it resides. The PerisOme; froin the Smul sige of the animal, it is no eas to determine whether the uppe rinior Oint of the stem does no more properly belongio his pari, to Whicli it serves as a basis 'he Perisonae itfel croWns the stem, surround stheiod of the animal, an serves as the basis o supportis the urnasci It is composed os a single series of sive Ossicula orion plates, o considerable hickness, of a Nedge hape, having the broadest enit uppermost, hicli is distinctlynotched for the articulationis the sirst oint of the aruis. The Arnis hicli are sue in number, areb Oined to the apices of the pieces Whicli constitute the Peris me, ach of them bifurcatinifroni the secondJoint, foras torepresent a Star With ten ray thes branching o division of the arnis, are
Therave mali scales hic sorm the elvis, ascit has been calle in Pentacrinus Caput Medusae, probabi exi St, hut are to minute to admit of heinc easti demonstrated. - The PerisOme acabove corresponds With r. illar' first Costais, hich by a refereuce to his Genera o Poteriocriuites, Cyathocrinites, ria crinite an Marsupites, evidentlyrather apperti,in to theiody than to the arms.
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composed os a single series of solii calcareolas oinis, aboli 24 in number, diminishing graduali in thiclines froin thei Origin*pWard ; at either si de the appea fringed With sos tentacula, hicli are Ointed capable os considerable contraction and extension and of ein move in every directioi these tentacula aris Doni the opposite fides of the divisions, or branches of the arnis, in an alia ternat order, and when bighly magnifie appea tote themselves furnished with capitate cilia, alternately place along thei Sides It is these aritis, composed of numerous Oinis, and fringe With tentacula, bichiive to the Crinoide such beautim appearance ; at ne time, prending ut ard like the petalcos aflower, ut another, Olle in Wardmove the mouth of the animal like an expandia inglud : Froin thei structure an movemenis, it can hard lyi doubted that the serve to ei Zelpon and convento the mouth, Whateve has been destinedsor iis mod, and whicli probably consist in ver minute animal iis powersonabiecit O Over Ome. In some of the more ad vance specimens, Whicli,ere Subsequently obtained, the aruas appearuo bifurcat a secondiundis hir time, O more, at Or ea tothei apices gaining at the fame time a rox os dari coloured Spot along achside, and a deeper tint of sulphurbelloW, especiali toWard thei extremities. The Lo , hici bears no distant resemblance to a mediar, is lodged withinthe cavit forme by the ossicula of the perisum and the basilcioints of thearitis, appearinito e intimately connected Withioth it apex present a central peninio mouit, formed by sive petat-like alves, Whicli possess the poweros expanding or of oldinidown losely, sorus to but up the outh ith in
these valves hen expanded, severat of tentae Ula preSent thenaseives, similarin structure illi the tentacula os the aritis: the mos remat Labie par of iis Structure hoWever, consist in the existenceis a distinc termination to tho alitamentur canal, Whicli perforating the fide os thebody belo the insertio of the valves of the molith, nds in a tubula ope ninio considerable sige, and capableos a very rem arkable degre of elongation, beiniat times a conspicuous in his respect ascit is at others difficultrio discern This unlookedior peculiari ty neruas relates to the Asterias, no only throws a light o the Structure of the Crinoidea, and Blastoidea, ut has been the means Pleadin to the discover os a simila structure in the animal of the genus Comatula.
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Having one sussiciently in delat in to the structure of this neW animal, it re- main to notice the observations hich have been madetpon iis growth andalthough it has notiee possibi to do this, ab ovo,V it must assor a sensibie gratification to every philosophi mirad that froni the specimen ali eady obtained, we an trace iis evolution and progress through so considerable a portion o iis existence, as to thro a very satisfactor light upo the subjeci. The mallest specimen observed, didiot exceed one-eighthis an in ch in height: in his stage, the animal resembles a litti club, fixed by an expanded basis, and givin exit at iis apex to a se pelluci tentacula no other par of the solidlabri is observabie ut an indistinc appearance of the perisOme. In those specimens, hich have made a litile more progress together With the elongationos the pedici or stem, it joint begi to mali their appearance, theiod acquires a large Sige, and brownisti tint, Dom agrosser ood the tentacula os themouili protrude in a greate degree, an move Alowl in various directions onother stili more advanced thecioints of the stem ecome quite obvious, Domtheir opacit and white colour, and the age of the future aruis, a mellius theauxiliar side aritis, are rendere palpabie. The armifro in his perio tengthen ac froni thei bifurcation, an have superadded to them, a dolabi range of transparent, oin te tentacula, so that he animal begincto putis a more perfectappearance audiso sor Some time, meret acquires a someWhat greater Sige, and an extensionis iis arnis, Whicli although the solidis froin their origin*p-wards, emat pelluci and thic a thei apices, Where elongation, evolution, and the secretion os calcareous matte is gradually going on. As observe above, specimens ere subsequently Mund in hicli the arnis again bifurcuted at o nea to their extremities, a secon an even a third time, and whicli,ere fuit three-quartorsis an in ch in eight, and the expansion ftheir arminearly three-eighthios an inch. Some of these more latet discovered Specimens, Seeme to explain a circumstance notice by r. illa in re-garda Pentacrinus Caput edusae, vig the occasiona inequalit of the arms; a the had ometimes ne an ut ther tW or more armS, OnSiderablyShOrte than the rest, Without an appearance t Warrant the idea of their having been brohen offand reproduced so that thelower of their being ablesto reproducelos paris, although probabie remalias tot proved.
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Froni these observation connected illi the roWth of this animal, and by whicli it appears to present itSel ut various stage of iis progress unde considerable diversit of forni, aturaliSis may learn to avoid the u necessar multiplicationis the genera und species of the riuoidea, b giviniundue,eightand consideration to characters originatin in the progressive evolutionis individua species, and Whicli are consequently osa tranSitory, and delusive nature. Thus then, by the ortunate discover of this minute Pentacrinus, W gai amore complete and precis idea, these animais, than ali the specimens of the comparati vel giganti Pentacrinu Caput edusae have been able to impari, notri mention the fossiis of this tribe, hich could neve assor a jus idea osthei nature, Doui the tota destruction o ali heir of paris in the proces of lapidiscation, and the uniformi close positio of the arvis It is no placedheyon doubi that thenare stipitate Asteriae, O Star-sisti, disserinthoWever, Domati the known genera an species, but certaini mos nearly relate to the genus sirs instituted by Dr. Leacti, unde the nam eis Alecto, and subsequently pub-lished by Mons Lamarch, unde that more generali adopted of Omatula, and of whicli the Asterias Decacnemos o Pennant, i the mos familia example Μr. Milla seem to have been therarsi person Who justly appreciate this relation-shis, roria a minute comparison belWeen this last animal, and thos of his genus Pentaurinus, ut a he hadiso opportunit o consultinian other than driel specimens os Comatula, he has allo eum to anticipat him in another remarkable discovery, viz. that in common,ith the Crinoidea, this also possesses a distinc termination to the alimentur canal, in connexion,ith another curious faci that theiod of the Comatula, When the animal saept in a mali quantityos ea-Water, is Soon de tached entire an perfeci Domuli cavit in whicli Dislodged, and in his state, might emis talien or an animalis a very different tribes asse naturalist Seem tote acquainted withmullers genus of Μammaria, it ma be suspected that this faci, above allude to may have give riserio an error On the partis that distinguished atural Historian particulari a the laterat Ope ning is generali much more prominent thun the central one or mouilici For a representation O theiod of Comatula thus thrown C se plate 24ς. 3, 4 5, hicli Irars observexati figured, unde the impression that it Was a
The bove clarumstances regariling the Comatula appea to e stirther iniportant, in throri in a light o Dr. Bigsby's fossit radiata, do crihed an figure in the s.coti volunte, Zoological dournul page l8, late XI. g. 5. Whicli Probabi has heen theiod of some large species of comatula, O a cotigenerous animal the laterat Opetaing, considere ih Mr So ei hylas the mouit, hein no dotati the auat ape tuteri: a retracte state, the Orat OS Piobabi occupi edili fame centra positi oti as in ali the Other Asteriae.
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peculiar animal relate to aminaria. Whether the od thus delached is cap te os livingan time in his separate State, or os reproducinitis aruis, c. remaincto e ascertained. Although there is reason to presume that the major partis the fossit Crinoidea, Were formed after the above type, et it appear extremel probabie, that Someo them might approach the other gener of the sterias, particularly the Euryale, an Ophiura o Lamarcti Which have but ne central penini this gainsgreater probabili tydrom tbe laci, that in the more recenti discovere fossiis, the Blastoidea, this more 3imple structu resis observed thes it ma be noti ced, excepi in this one pollit, approach to the Echini oriea-eggs, an have notinny linoW analogous livin species hoWever, We mus no hastil conclude that non suchio actuali exist We lino so very litile of the inhabitant of the dees, iliat, shouldi cautious in cominit suci a conclusion the precedin histor of the Pentacrinus, Ahouldie a lesson to uturalist in his respect in re-gard to the existence of marine animal, of Whicli the remain osse them selves toout observation alone in the fossi state Morio many years elapsed froni thesii si discover of the fossi Crinoidea, besore an livin species presented itselfland during the last hal century althoughmatura Histor an Geology, have been purgue With a eat an ardour, and With ad vantages Oo, here tofore un-known not above hal a dogen in the whole have ound thei Wanto Europe, - so that the stili continue tot regarded, as amorig8 the mos rare, and valvable acquisitions in collections os natural objecis. The Pentaurinus Europaeus has eun itherio mund attache to the various species of Sertularia, and Flustracea whicli occur in the deeperiaris of the har- bour os ove, vig. in rom ight to ten athonis, frequently intermixe With anondescript compound animal, presentin t the y the appearance of tho halia grown Pentaurinus, but Whicli, is mos probabi a stipitate ascidia, and may bereadit linownb iis tubula creeping OOis, antis tentacula, and by iis tembeinifleshy, and void os articulations.
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Is an apolog be necessar so the illustrative plates, it ma be observed that What the want in elegance and finisti, is more than ad umby the faithminesswith whicli the have been iven, a merit the might noti ave possessed had the passe through themand of an engraver.
PLATEI. sg. I. A grou ostentacrinus Europaeus os the natura sige. Fig. 2, The fame magnified D-a, an individual fuit expanded shewing the mouili in frontand theanus, fri indicate the bases b, another individua in a sume What cl0sed state k- c, one4hewing the manne in Whicli the animal somelimes coiis ulmit stema in both of the se last Do the positionis fili animal the auxiliar side arm are conspicuous p d, an individual oni socia advanced in growthas to sile distincti the articulations of the stem, the perisOme the basilcioints of the arms, and the oscular tentacula ; - e, an individua so litti de vel Ope a to he hardi an of the soli paris, butprovided with the means of takin in substanc by it Oscular tentacula. - These sive specimens areae- presented a attached to the stem os a coraline. Fig. 3. The base fine of the arm higbi magnifiex: - a, ne of the scales of the perisOm p b,srst oint of the arm k- e second oint; - d, thirlici ut in pair commencing the bisurcationis the arm. Fig. 4, One of the auxiliar si de arm bighi magnified. Fig. 5, The apex of one os the fame in an early tage of rowth, stili more magnified. Fig. 6,-The bod of the animal considerabi magnified the arm bein removed hom their articulationWith the erisOme γ- a bod o stomach, c. 4 valves of the mouth - c, rectum in iis elongated State ἔ- , extreme or anus P d, oscula tentacula - , periSome -Τ, auxiliar side arm γ- g, upper Joints of the stem. Fig. 7, a portionis one of the arm magnified, t shois the appearance and alternate position os thessest, tentacula. Fig. 8, - ne os theraesti tentacula os the armchighly magnised exhibitin iis capitate cilia. PLATA II. g. I, - he basis of a Pentacrinus Europaeus giviniorigin t tW stem : - a bases; b, b, base of the stem cui orsrom the second oint. Fig. 2, - b uppe partis a Pentacrinus Europaeus magni sed, hoWing the more ad vanced roWth of the animal the trifurcationis it arm s and the sitois With, hieli the become ornamented - a, a secondbifurcatio of the arm p b, b, hird do. - c uppe par of the stem. A figure of the natura si geris placedis iis right. Fig. 3. Bod os a Comatula, when delached a see stomaeneath, oscit natura Sige.