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ceed, having each two hands, composed of several tentaculated fingers. Column long, having numerous auxiliary side-arms. Base not ascertained.
Pentacrinus Caput Medusae. Description. A crinoidal animal having a column formed of numerous pentangular joints, articulating by surfaces with pentapetalous, ovate, striated markings; five auxiliary side-arms formed of round joints proceeding from the column at intervals. Superior columnar joints supporting a pelvis of five plates, to which the first costals, second costals, and scapular, succeed, from which ten arms proceed, each supporting two hands, subdividing into three fingers. Lower extremity, or base, unknown. (Miller.)
This is the Encrinus Caput Medusae of Lamarck, Isis Asteria of Linnaeus. Locality, the seas of the Antilles. Near the island of Barbadoes (Dr. Hunter's specimen)— that of Nevis (specimen formerly belonging to James Tobin, Esq., now in the British Museum)—and Martinique (spe“imen in the Paris Museum). There is also a specimen in the Museum of the Royal College of Surgeons in London, and one in that of the Geological Society of London.
Mr. Miller, in speaking of Mr. Tobin's specimen, says, “In the drawing it up from the bottom of the sea, the animal has clearly been broken off, leaving its posterior portion behind; thus we have lost the chance of ascertaining the fact, whether it adhered by a fixed base, or had a locomotive power. The same accident has befallen the other recent individuals that have been mentioned when speaking of the locality of this species. However, judging from its analogy to the Encrinus moniliformis, from its long column, numerous auxiliary side-arms, and the associated manner in which groups of the following species are sometimes found preserved on the surface of a single slab, with the columns all tending towards the same point, as if
issuing from a common base, I conceive that this species also adhered by a base to extraneous matter. This idea gains some further ground, from all the recent specimens hitherto found having broken abruptly off in the endeavour to remove them, as not being able to free themselves from the points of adhesion, which certainly would have been the case had the animal possessed a locomotive power. This inference acquires additional confirmation from the observations made by the late J. Tobin, Esq., on another specimen, viz. –“Some years ago I was in possession of a larger Pentacrinite, which was brought to me so fresh out of the sea that at the bottom (where it plainly appeared to have been broken off from the rock to which it was fixed) the blood was actually oozing from the vertebrae. This specimen I endeavoured to preserve, but it was totally destroyed by the ants, who ate every cartilage, so that it fell to pieces.’ Miller observes upon this, that the “blood’ was the fluid in the alimentary canal, and refusing to admit the assertion of Walch, that the Pentacrinite is an animal crawling along the bottom of the sea, conceives it to have generally stood more or less erect in the sea, yielding to the fury of the storm in bending down, and adhering for additional security with its side-arms to extraneous matter, or closing them to the column, and thus offering the least surface possible to the element. The latter, he thinks, is the most probable idea, since he had frequently met with specimens in that state, but had never seen any side-arms clasping round extraneous matter. The author elsewhere states that he has in vain endeavoured to trace apertures at the terminating points of the fingers and tentacula, although Guettard alleges that here orifices existed serving as mouths to the animal in taking its food. Miller observes that columnar fragments, smaller and rather neater than those of this species, occur in the oolite at Dundry, the forest marble at Chippenham, and the chalk near Lyme, but that it remains to be ascertained, by the acquisition of perfect specimens, whether these belong to a variety of P. Caput Medusae, or possess peculiar characters sufficient to distinguish them as a new species.
We select, as an example, the Briarean Pentacrinite, Pentacrinus Briareus, thus characterized by Miller. “A crinoidal animal, having a large column formed of numerous entagonal joints, alternately larger and smaller, articuating by surfaces with pentapetalous compressed semistriated markings; five auxiliary arms, formed of much compressed suboval joints, proceeding at intervals from the column; five joints of the pelvis, supporting five first and five second costal joints, on which the scapulac affix, from which ten arms proceed, each having two hands, formed of numerous fingers, sometimes amounting to sixteen.’ Dr. Buckland observes that the root of the Briarean Pentacrinite was probably slight, and capable of being withdrawn from its attachment. The absence of any large solid secretious like those of the Pear Encrinite, by which this Pentacrinite could have been fixed permanently at the bottom, and the further fact of its being frequently found in contact with masses of drifted wood converted into jet, leads him to infer that the Briarean Pentacrinite was a locomotive animal, having the power of attaching itself temporarily either to extraneous floating bodies or to rocks at the bottom of the sea, either by its side-arms or by a moveable articulated small root. ow. confess that we cannot entirely concur with the professor on this point. That in early youth the animal may have floated till it found a substance fit for it to adhere to, we do not deny; but we think that after it was once established and had attained a good size, it was fixed for ever. The great length of the stem and the numerous side-arms must have secured for it a field of action beyond that of the Pear Encrinite and the Lily Encrinite, both of which we know had permanent roots; and if we are to Judge by analogy, there is pregnant evidence that the specimens of the living species, more especially the larger one mentioned by Mr. Tobin, who saw it quite fresh out of the sea, and to whose expressions above given we refer the reader, suffered their stems to be torn asunder without quitting their moorings. Locality.—Lower strata of the oolite formation, especially the Lias: Lyme, Watchet, Keynsham, &c. Mr. Miller gives three other fossil species, viz., P. subangularis, P. basaltiformis, and P. tuberculatus. Goldfuss nas recorded the following additional species, viz., P. sca. laris (Goldfuss), P. cingulatus (Münster), P. pentagonalis (Goldfuss), P. moniliformis (Münster), P. subsulcatus (Min: ster), P. subteres (Münster), P. dubius (Goldfuss), and P. prisous (Goldfuss), and, with a note of interrogation, Pentacrinus? paradoarus.
a, Pentacrinus Briareus reduced (Lyme); b, rare and beantisml specimen of 13, it rean Pentacrinite (nat. size), from the lias at Lyme Regis, in the collection of Mr. Johnson, of Bristol, showing the plated integument of the abdominal cavity, terminated upwards by a flexible proboscis, and sur: rounded by the commencement of the arms and fingers. (Figures and description from Dr. Buckland's ‘Bridgewater T.u.)
(De Blainville;—Hibermula, Fleming; Thompson.)
Generic Character.—Body regular, circular, covered and surrounded above by a sort of solid cupule, composed of a centro-dorsal undivided piece, round which are articulated, first, a single row of accessory unguiculated rays, then another row of great didymous and pinnated rays on the other side of three basilary joints, of which the first only partially touch each other. Stem articulated, round, and without accessory rays. Mouth central in the midst of five scales, which are foliaceous and bordered by a row of tentacular cirrhi; a large tubular orifice a little behind the mouth. Example, Phytocrinus Europaeus, Pentacrinus Europaeus, Thompson.
Pentacrinus Europaeus of Thompson.
a, Several individuals in different stages of development adhering by the base of an articulated column to the stem of a coralline; b, one of the individuals expanded and magnified.
M. de Blainville states that he has thus characterized this genus, which he had not seen, from the excellent description, and figure of Mr. Thompson; and that it seems to M. de Blainville that there are sufficient differences to warrant the generic distinction of the animal. He observes that in
o!'. the stem is round, perhaps even inarticulate and flexible; that there are no accessory rays except at the summit; and, besides, that the great rays are all otherwise conformed in their basilary as well as in their pinnated part. It may be supposed, he adds, that the membranous part of the body differs equally both in the disposition of the mouth and in that of the visceral pouch; but of this there is no assurance, that part not being known in the great living Pentacrinite. He remarks that Dr. Fleming, admitting the doubt of Mr. Gray, as to the existence of the visceral pouch in this last, has also characterized the European Pentacrinus under the name of Hybernula, a name which he allows may be adopted, though he gives the preference to his own as being more analogous to those invented by Mr. Miller for the Crinoideans. M. de Blainville goes on to declare that he has already had occasion to say that Mr. Thompson's memoir has destroyed all doubt as to the place of the living and fossil Encrinites, and has clearly demonstrated the justice of the views of Rosinus, adopted by Guettard, Ellis, Parkinson, and Cuvier, in opposition to that of Linnaeus followed by Lamarck. “An Encrinus, so to speak,’ says M. de Blainville, “is no more than a Comatula reversed, (even supposing that this position is not equally natural to it, which I am strongly inclined to think,) and which, instead of hooking on by means of accessory rays, is fixed by a prolongation of the centro-dorsal part.' However more appropriate the name proposed by M. de Blainville may be, that of Dr. Fleming would have the right of priority according to the law of nomenclature; but if Mr. Thompson be right we are spared all consideration on this point; for in the ‘ Proceedings of the Royal Society of London’ (June, 1835), he has expressed his opinion that his Pentacrinus Europaeus, discovered in the Cove of Cork, and on other parts of the coast of Ireland, is fixed by its stem to other bodies in early life only; that it is produced from the ovum of Comatula, becomes afterwards detached, and forms a perfect Comatula, capable of moving freely in the ocean, crawling sometimes among submarine plants, and at others floating or swimming like the Medusae.
Generic Character.—A crimoidal animal, with a round column, composed of numerous thin joints, having in their centre a round alimentary canal, and articulating by surfaces striated in radii. und auxiliary side-arms proceeding at irregular distances from the column. Pelvis formed of five pentagonal plate-like joints, supporting five hexagonal intercostal plate-like joints, and sive plate-like scapulae, having on one of the intercostals an interscapulary plate interposed. An arm proceeding from each of the scapulac. Base probably fascicular, and permanently adhering. (Miller.) The author of this generic character says, “It is with considerable hesitation that I describe these five plates as belonging to the pelvis; the analogy of their lower articulating surfaces seems perhaps #. to indicate their belonging to the first costal series. I have never yet had an opportunity of seeing the connection of these plates with the first column or joint fairly developed, and it seems possible that the true pelvis may be small and almost concealed. This doubt will be done away by the acquisition of more instructive specimens, and my thus stating the case must be considered as resulting from an anxious desire to check errors. It is not unlikely that the real joints forming the pelvis are so much abbreviated as not to be visible externally. Every one acquainted with fossils must be aware how difficult it is to trace always organic details in them correctly, and how many specimens are sometimes necessary to ascertain a single fact.' M. de Blainville observes that this genus does not appear to differ from Apiocrinites, excepting inasmuch as that the stem is not enlarged at its superior part, and that the basilary pieces of the rays are less approximated, and without doubt less immoveable. The details given by Mr. Miller point out a form differing strongly from that of Apiocrinites, and, if his data be admitted, there can be little doubt of the generic difference which he records. Example. Poteriocrinites tenuis. shaped animal. escription.—A crinoidal animal, with a column formed of numerous round thin joints, surface of articulation radiating and striated. The plate-like joints forming the cup
Thin, vase-like, lilylike body, articulating by minute striae. One arm proceeding from each scapula, supporting two fingers. Locality, the mountain-limestone of the endip Hills, and in the Black Rock (the fourteenth bed of Dr. Bright's series (Geol. Trans., vol. iv. p. 193), near the river Avon, Bristol, belonging to the same formation. QMiller.) - - The other species recorded by Miller is Poteriocrinites crassus, from the mountain-lime in Yorkshire, and the mountain-lime at Bristol, near the river Avon, Bed 1. and ii. of Dr. Bright's paper in Trans of Geol. Soe, vol. iv., p. 193, and in the magnesian beds of the mountain-limestone, Clevedon Bay, Somersetshire. Miller further states that the specimen mentioned in Dr. Woodward's catalogue of foreign fossils (page 19, 8.1.) as coming from Syria, is of this species, and that he (Miller) is indebted to the Rev. A. Sedgwick, Woodwardian Professor, Cambridge, for ascertaining this fact, he having kindly furnished Mr. Miller with a drawing made from the original, now in Dr. Woodward's collection, and under his care.
Generic Character.—A crinoidal animal, with an elliptic or (in one species) pentagonal column, formed of numerous joints, having a few side-arms at irregular distances. Pelvis saucer-shaped, formed of three unequal pieces, from which five large plate-like scapulac proceed. Base provided with numerous fibres for attachment. Miller, who thus characterizes the genus, observes that the want of costae supplied by the large plate-like scapulac gives the superior part of these animals a pentagonal appearance, and furnishes so conspicuous a character, that they are readily distinguished from all other genera. Example. Platycrinites laevis, smooth, broad-plated, lily-shaped animal. Description.—A crinoidal animal, with a column formed of very muscular elliptical joints adhering by a transverse ridge. Round side-arms occasionally proceeding from the column, whose joints adhere by radiated surfaces. Pelvis saucer-shaped, with the five scapulac adhering to it, from each of which an arm proceeds supporting two hands, having each two fingers. Pelvis and scapulac smooth. Locality, in the mountain-limestone of the Mendip Hills, the Black Rock (14th bed of Dr. Bright's series, in Geol. Trans., vol. iv.) near Bristol; Dublin; Cork. (Miller.) Miller remarks that he has noticed in the collection of Richard Bright, Esq., of Ham Green, near Bristol, numerous joints, probably appertaining to an animal forming a variety, or a distinct species. They came, he states, from Muir-kirk, in Dumfriesshire; and he adds that the scapulac are shorter in proportion than those of the former species, and that the columnar joints are finely tuberculated. The same author records the following species:—P. rugosus, from the mountain-limestone at Caldy Island, on the south coast of Wales; and at the Mendip Hills; P. tuberculatus, from the mountain-lime strata; P granulatus, from the mountain-limestone of the Mendip Hills; P. striatus, from the Black Rock (14th bed of Dr. Bright's series); and P. pentangularis, from the mountain-lime of the Mendip Hills, at Weston-super-mare, Black Rock near Bristol, and at Mitchel-Dean; also occasionally in transition limestone of Dinevawr Park, and Dudley. Goldfuss names and describes two additional species, viz. P. depressus and P. ventricosus.
Generic Character.—A crinoidal animal, with a round or pentagonal column, formed of numerous joints, having sidearms proceeding irregularly from it. On the summit adheres a saucer-shaped pelvis of five pieces, on which are placed in successive series five costal plates, five scapulac, and an intervening plate. From each scapula proceeds one arm, having two hands. Locality, transition and mountainlimestone strata. (Miller.)
Example. Cyathocrinites planus.
Description.—A crinoidal animal, with a round column formed of numerous depressed joints, articulating by ra. diating surfaces, and perforated by an alimentary canal, pentagonal, near the pelvis, which becomes round further from it. From each of the scapulac, which rest on the summit of the cup formed by the pelvis and costae, proceeds an arm supporting two hands, each being provided with two series of fingers. Locality, Clevedon, in the magnesian
beds of the mountain-limestone; at Wood-spring. Black Rock (14th bed of Dr. Bright's series), near Bristol. iller.)
Miller observes, that a specimen had occurred to him where the columnar joints were alternately smaller and larger, but that he was not aware whether it possessed sufficient character to be considered a variety of the former species. The same author records three other species, and Goldfuss has added three more, viz. C. pinnatus, C. geometricus, and C. pentagonus.
Generic Character.—A crinoidal animal, with a round column composed of numerous joints, perforated by a round alimentary canal. At the summit of the column is placed a pelvis formed of three plates, on which five first costals and one irregular costal adhere, which are succeeded by the second costals and intercostals and the scapulae, from whence five arms proceed, forming two hands with several tentaculated fingers. Round side-arms proceed at irregular distances from the column, which terminates at the base in a fascicular bundle or root of fibres.
Example. Actinocrinites Triacontadactylus. Thirty
fingered, radiated, lily-shaped animal. (Miller.) Plant (Beaumont), Nave Encrimite (Parkinson). Description.—A crinoidal animal, with a round column formed of many joints, on whose summit is M. a pelvis of three plates supporting five hexagonal and one pentagonal costal plate, on which the second costals, intercostals, and scapulac, in series adhere, the latter sending off five arms, having each two hands provided with three fingers. Column sending off at irregular distances auxiliary sidearms, and terminating at the base in a bundle of fibrous elongations resembling roots. Locality, mountain limestone at the villages ission and Stokes, in Craven, Yorkshire (Lister, 1674), mountain lime formation of the Mendip Hills (Beaumont), and the . Black Rock near Bristol (Miller). Miller describes another species, A. polydactylus, from the mountain limestone of the Mendip Hills and Caldy Island. De Blainville observes that among the five (seven) new species which Goldfuss refers to this genus, viz. A. granulatus, A. tesseracontadactylus, A. cingulatus, A. muricatus, A. nodulosus, A. moniliferus, and A. tesseratus, A. tesseracontadactylus appears to De Blainville to offer a new combination of the pieces of the test, and even, perhaps, of the ten rays of the root, each division being dichotomous.
Generic Character.—Column smooth, perforated by a smooth or quinquelobate canal. Auriliary arms. . . . Pelvis composed of four articulations or pieces. Primary and secondary costals five, hexagonal, alternately placed (sibi invicem impositi). Intercostals five, hexagonal. Scapula five, hexagonal, placed upon the costals. Interscapulars four, in the region of the mouth five. Arms five. Mouth at the side of the vertex.
Example. Melocrinites hieroglyphicus. (Goldfuss).
Description.—Melocrinites with the articulations or o of the cup or calyx nodulous. Locality, mountain ime, calcareum montanum Eifliae.) Goldfuss records a second species, viz. Melocrinites lavis.
Generic Character.—A crinoidal animal, with a round and sometimes slightly pentagonal column, formed of numerous joints perforated by a pentapetalous alimentary canal. The pelvis formed of three pieces supporting five square plates, in the spaces of whose lateral bevelled angles five heptagonal first costals are inserted. From the scapulac proceeds an arm supporting two hands. (Miller.)
Example. Rhodocrinites verus, true rose-like lily-shaped animal. Locality, upper bed, No. 1, and one of the lower beds, No. 15, of Dr. Bright's series, distinguishing the mountain limestone formation along the river Avon near Bristol, the Mendip Hills, Mitchel-Dean, the transition limestone at Dudley. (Miller.)
Goldfuss adds four species, viz. R. gyratus, R. quinquepartitus, R. canaliculatus, and R. echinatus, the last being Encrinus echinatus of Schlotheim.
M. Goldfuss describes two other species, S. scrobiculatus (Münster), and S. Jaegeri (calcareous) (Goldfuss), from the Jurassic limestone, Baireuth.
Generic Character.—Pelvis of four plates. Costal plates six. Column not dilated. Alimentary canal round. Articulating surface of the columnar joints radiated. Auriliary side-arms cylindrical and placed irregularly.
Example. Caryocrinites ornatus. Description.--Costals, four pentagonal and two hexagonal., Column inserted into a cavity at the base of the pelvis: pelvis rather large; two of the plates quadrangular, attenuated to the base, where they are truncated and a little recurved at the junction with the column; disks, particularly towards the base, granulated, with a distinct elevated interrupted line; two remaining plates pentangular, attenuated to the base, where they are truncated and a little recurved at the junction with the column; disk with elevated granules, and with two elevated interrupted lines extending to the terminal angles: costals, four pentagonal and two hexagonal, all with elevated interrupted lines, radiating from the centre to the angles, with a series of truncated granules on each side, and a few granules in the intervening spaces; interscapulars, two hexagonal, situated immediately above the hexagonal costals; scapulars six pentagonal, the upper sides of which are more or less irregular by projecting a little between the scapulae, all with prominent lines granulated, similar to those of the preceding: arms six: capital plates with a heptagonal one in the middle, surrounded by five heptagonal plates and two irregular ones at the mouth: mouth not prominent, situated on one side of the middle, a little within the line of the arms, closed by small valvular pieces, its inferior side resting on the superior angle of one of the scapulars. Longitudinal diameter from three quarters to one inch and a half; transverse diameter from seven tenths to one inch and two fifths. Mr. Say, who gives this description, records and describes another species with one of the costals hexagonal, viz. C. loricatus. , Locality: Found by Dr. Bigsby loose n brown clay at the foot of the ravine at Lockport, in which the New York canal mounts the parallel ridge of Lake Ontario.
Marsupites (Mantell), Marsupiocrinites (De Blainville).
Generic Character. — Body regular, oval, bursiform, rounded at the dorsal extremity, truncated and flattened at the other, enveloped in a sort of shell or test composed of great polygonal plates, articulated to each other, one centrodorsal, and three rows superposed, of which the terminal one supports ten simple rays. Mouth in the midst of four squamiform pieces. Stem none. This is De Blainville's character; the following is Miller's:–An unattached animal with a subglobose body containing the viscera protected by calcareous plates, of which that in the centre at the base is angular, having a series of costal plates resting on it, admitting intercostals at their superior angles, these giving insertion to the scapula from which the arms proceed. Space between the scapular covered by an integument, protected by numerous small plates.
Example. Marsupites ornatus, ornamented purse-like animal (Miller), Tortoise Encrinite (Parkinson).
Description.—A purse-like” animal, having the central plate at the base of its subglobose body containing the viscera; pentagonal, supporting at its edge five similar costals, which admit at their superior angles five hexagonal intercostals, into the angles of which five scapulac are inserted sending off the arms. All the P. ornamented by ridges proceeding from the centre, and forming o markings near the corners. Locality, Offham Chalk-pits near Lewes; Clayton Chalk-pits, #u. Sussex; Preston Chalk-pits, near Brighton (Mantell); Chalk-pits of Kent, and Chalk-pits, near Warminster. (Miller.)
Mr. Miller does not admit Marsupites among the Crinoidea, but considers it as the immediate link between that family and Euryale.
Generic Character.—Column cylindrical, perforated; segments articulating by radiated surfaces, with cylindrical side-arms at irregular intervals; pelvis of three unequal pieces, two pentagonal and one tetragonal; scapula large, very profoundly emarginate for the reception of the lips of
the radiating ambulacrae, obliquely truncated at the extre-
separate what Say calls the ‘pelvic scapular and intersca-
in the French language.