Memoirs MCZ 2502

b) The remainder of the crown belonging to specimen B, not figured by Billings Upper part of calyx and portion of arms and pinnules; Original of Billings's Fig lc — greatly flattened, but very perfectly preserved on one B fractured edge adjoining D is side The not quite perfect, some small pieces being broken off (PI I., Fig 3a) Several pieces of column, nearly continuous from B, with terminal root, the original of Billings's PL fig Two lg of these are figured herein, and od, and the root, Fig 3c Specimens B, C and D are parts of the same individual, which fit together very well, except at the junction of B and C, where I., Figs 3c the edges of some plates are somewhat frayed by accident in col- where a piece is wanting The basal portion of the cabyx, 'being of very firm and rigid construction, was only slightly affected by pressure; but above, being lecting flexible and between 3d and ; and composed of thin become quite E it plates, it was flattened out, so as to fragile in the fossil condition, resulting in the frac- ture and loss of parts of where 3c, some plates when exposed in the quarry was found A very large crown, consisting of the calyx, with a very The small portion of the stem, and the bases of part of the arms C magnificus surface of this specimen bly injured is very The preservation soft is and friable, and it is considera- quite different from that of those CLEIOCKINUS 98 above mentioned, which evidently occurred in a fine grained shale, softer than the included fossils while in this the enclosing matrix ; is harder, and not readily removable without carrying the surface of the F A fossil with it (PL I., Fig 11) large stem, thirty inches long, with the root attached It was found same quarry with specimen E, and there is good reason to bebelonged to it; but a portion of the stem at the proximal end in the lieve is G missing, probably amounting to five or six inches Part of another still larger stem, similar to F (PI I., Fig 12) STRUCTURE OF CALYX AND ARMS THE ARMS AND PINNULES The first observation of these specimens are pinnuliferous, — a fact made clear the fact that the which has been overlooked arms in the discussions here- although, as already stated, Billings, in his description of C regius, " Dec IV., p 56, mentions the presence of tentaculated, free rays." tofore ; The Fig structure of the arms a) They are direct shown by specimen C (PI I., continuations of ridges which follow the is perfectly brachial series in the calyx, beginning at about the first bifurcation with and gradually enlarging until they pass into the free arms These are quite angular on the back, simple, uniserial, composed of short, wedge-form plates, each of which gives off a pinnule from the faint linear elevations, longer end At somewhat The pinnules are slender, and irregular distances below lie close together (PL where the arms become I., Fig 10) free, at the outer margins of the rays, there are given off subordinate branches, which originate on a bifurcating plate and lie closely alongside the outer arms of These subordinate the ray, the plates of the two abutting and interlocking branches are the proximal portions of fixed pinnules, which are incorporated in the calyx walls, and apparently become free between the arm though they are concealed from view by the regular pinnules In other interbrachial spaces higher up, from the last IIIBr or IVBr, and bases, mostly on the outside of the dighotom, similar pinnules are given not with entire regularity (PI I., Fig 8) All these are closely joined together and to off, but the adjacent arms, and incorporated into the calyx walls, until they reach the upper margin and become free The arms are quite clearly shown in Billings's type specimen (PL I., Figs 1, 2), where the bases for a distance of several brachials are in some places well preserved, having the pinnules attached, of them is as well shown as in specimen C — though neither 100 CLEIOCRINUS THE CALYX The calyx plates are all closely abutting, — the suture lines, both between marked by successive brachials and between those of adjoining series, being small pits, or crenulations, indicating a union loose suture, such as the structure we by a sort of articulation, or see in specimens of Forbesiocrinus decidedly like that of the Ichthyocrinidae is plete absence of In this respect There any interbrachial system, except at the anal of plates, originating on the posterior basal, vertical series between the arms, though not quite to the general characteristic of this calyx the is side, rises a com- where a high up The main margin of the cup manner is which the ray divisions in are joined to each other by lateral union of their plates with those of their and with the plates of the anal series Billings fully appreciated when in his generic description he noted as a feature of the structure of fellows, this the genus its of the cup." " numerously divided arms The all soldered together in the walls and the mode of union plates are comparatively thin, between them imparts a marked degree of flexibility, — more, apparently, than in IcMhyoennus None of the specimens disclose any portion of the disk, but it is evident, from the manner in which they are flattened, that it was very thin and pliable Of the mouth and anal opening we know absolutely nothing The arms, the manner in which the radial ridges lead to them, and the structure and arrangement of the fixed pinnules, are very of Glyptocrinus and Rdeocrims is manner of like those but the interbrachial system of those genera being no supplementary plates, except at the whose vertical series bears some resemblance to theirs The entirely wanting, anal side, — there ; much compression of the calyx would indicate a disk structure more like that of Reteocrinus o' neatti and the Ichthyocrinidae THE BASE Examination of the specimens as they throw any new light upon the nature B is were received did not seem The column of the base — the exterior angles being obtusely pentagonal, claims a dicyclic base (PI I., Fig about one inch from the base, is b) The in specimen interradial, which pro- axial canal in this specimen, at also pentagonal, and its angles coincide 3/); which is a dealternation, and forms another minor exception to with those of the exterior of the column parture from the rule of to (PI I., Fig CLEIOCRINUS the law of Wachsmuth and — a monocyclic species is also 101 Springer, similar to that of Glyptocrinus fornshetti, in which both stem and canal are radial, and which from the Lower Silurian, among the earliest Crinoids Granting that there is a dicyclic base, the question remained, what is the exact nature of it and what are the five plates lying between the radials '.' ; them the "true Billings, with singular sagacity, called in ment, basals." the description of C regius (Dec IV., p 53), is His state- as follows : "At sight there appear to be ten small basal plates, but first five of these are found to be the first plates of the five mediately upon the upper joint of the column Wachsmuth and basal plates." upon examination rays which rest im- ; the other five are the true Springer, having classed the genus with the Ichthyocrinidte on account of the strong resemblance of its pliant calyx to had supposed that it might possess the basal arrangethe group, viz., basals and infrabasals, both hidden by the and they considered the pentagonal plates between the radials to that of Icldhi/ocrinus, ment of column ; be interradials arm Since it now appeared structure which differentiates zoic Flexibilia, there seemed to me it that the genus absolutely from pinnulate, with an all the known Pala?o- equally good reason to infer the presence of five infrabasals, as in the base of the dicyclic The is Camerata specimens furnished no information on this point and the only important fact gathered from the first examination of them was, as had been pointed out by W R Billings in a letter, that the superficial aspect of the ; proximal plates of the calyx not rest immediately upon the upper joint of the column, as stated by E Billings, but they seem to overlap the column, and form a ring around its upper edge The two specimens of C regius both showed this very plainly and they also showed the further ; curious fact that the five radially situate plates of this proximal ring, although having nothing to rest upon or to support them from below, at least exteriorly, are distinctly angular below was apparent, however, that no further information was to be obtained, unless we could find some means of seeing what is underneath the column My examination of the specimens gave no hope of being able to detach It the column in either of them ; but after a very careful study of specimen B, came might be possible to get at the inside of the base by removing a part of the plates above it This specimen preserved the first two rings of plates nearly in situ ; it was slightly flattened by pressure, and on the side opposite that shown in Bilunder a strong magnifier, I to the conclusion that it CLEIOCEIXUS 102 lings's Fig c the it were crushed in upper ring and some plates from the next ring above over the basal cavity, and cemented with a very fine, these could be removed, without destroj-ing the rest, we might see what lies next to the column The small size of the specimen, shaley matrix If and the uncertainty as to how the fractures might run, rendered the operation a delicate and risky one to undertake with a type specimen but I ; thought the benefit to be gained in case of success would warrant the risk accordingly laid the matter fully before Dr Whiteaves, and requested his authority to undertake it This he gave without hesitation, and in the I most my liberal own I manner, leaving me free to act with the specimen as if it were wish here to express not only my grateful acknowledgment for the personal confidence reposed in view also, in of the Whiteaves my in so delicate a judgment important result attained, my matter, but thanks as a palaaontologist he has conferred upon science, by furnishing the means of information which, in my opinion, there was no hope of I give this opinion, not only on account of obtaining in any other way to Dr for the benefit the rarity of the specimens, but of their poor preservation that I have ever seen the calcareous test rounding matrix adheres is to it so closely that soft and any kind In friable, all others and the sur- of fine cleaning is impracticable The work removing the necessary plates and debris from above the the specimen was tedious and difficult, being performed entirely base of of under a ten-power dissecting microscope, with tools specially fashioned out of needles and fine steel pens It was completely successful, however, and disclosed a structure most extraordinary and anomalous, unlike any of the previous suppositions, and wholly at variance without any mishap, with that of any other known Crinoid Instead of two, there is only one ring of plates inside of the proximal ring of so-called radials and interradials, which are seen on the outside and surrounding the column The axial canal is very large, and obscurely pentagonal and around it, resting on the column and occupying its full thickness, are five large, strong, quadrangular plates, sloping from within upward ; which are followed by the first and second primibrachs, not alternating with them but in direct succession, without the interposition of other plates The first plate visible externally to a thin upper face, radial]?/ situate, in the radial series is not, as a rule, visible at all from the interior when all CLEIOCRINUS plates are in place ; but 103 as well as the interradially situate plates, it, side of the lower ring and outside of the column, projecting out- is downward for Thus the ten plates forming the not, except as to the upper angular points of proximal ring exteriorly, one four interradials and radial, enter into the interior of the calyx wall a distance of one to four columnars proper, but are suspended on the outside of it They appear out of place, might have accidentally slipped clown around the column They are rather thin, and are firmly grown to the outside of the true proximal as if they ring of plates, the angular points of four of the interradials and of the right posterior radial rising slightly above their level The first primibrachs are exteriorly flush with the plates of the lower outer circlet, and rest them, being sloped at the lower corners so as to fit upon the angles formed by the upper points of the interradials, which are thus visible from the inThese first primibrachs also lie" directly above, but not rest terior upon, the plates of the inner The succession by their lie Thus the all radial in position, without which five radially situate plates any upon but by their outer, or dorsal, surfaces for the evidence of this Referring to Plate I., Fig b shows the distal edges, : specimen B from the right posterior side, with the lower and interradial plates as seen from the exterior, and the resting upon them and Figs and Fig 5a is flush with them showing the two from a photograph 2, retouched with the brush men rest within the ten plates of the outer circlet, and meet them, not upper or Now not alternating with them but in direct successive plates are alternation whatever the column circlet, — circlet of radial first primibrachs The same thing can be seen sides of the perfect calyx (Billings's — enlarged a and interior view c) two diameters by the camera, and of the opposite, or left lateral, side of speci- B, after removal of the plates and debris covering the basal cavity, an obliquely in — All five of the large proximal, radially situate in the middle Two plates are in plain view, with the large axial canal in direct succession with the and part of a third are in situ primibrachs last mentioned plates — — and, at the right, the first plate of the anal series, upon the posterior the outer circlet are visible, one slightly displaced, resting interradial plates of in the Two of the radial middle and one to the with one of the interradial plates between them The interradial to the left has been removed, leaving the exterior face of the inner proximal right, rests plate exposed, just as it upper points of two of the upon the column On the opposite side the interradials can be seen, between the lower CLEIOCEIXUS 104 corners of the primibrachs, and toward the right, the corner of the right In posterior radial, which differs slightly in shape from the other radials this figure the relative thinness of the plates of the outer circlet Fig b readily seen is more nearly side view of the same Here the angular lower edge of the a enlarged four diameters can be structure, radial of the outer circlet can be well seen, and the drawing shows very clearly which these plates hang suspended to the outside of the inner ones, and project downward over the column without anything for In both the last figures there appears a their angles to meet or rest upon the in way depression at the middle of the upper edge of This is some of the inner plates actually a shallow, lip-like groove, plainly visible on three of the apparently traversing the inner surface of these plates in a radial I cannot trace it upon the surface of the succeeding primibrachs direction which are preserved, but the inner surface of these plates is somewhat obplates, scure, and did not come out freely in cleaning If this groove be taken as showing the position of the axial nerve cord leading into the column, it would seem to indicate that the axial canal occupies morphologically its proper radial position in the calyx, notwithstanding its interradial crosssection below the calyx Fig is an attempt to show by a diagram of a vertical cross-section, the relative position of the plates of the inner and outer circlets, and of the primibrachs succeeding them, and also how the outer plates project downward over the column These illustrations will give a good idea of the structure as I interpret from the most careful study of the specimen which it was possible to make It will be seen from them how large and strong these inner plates it They form are a rigid ring surmounting the column, of construction than the succeeding calyx plates ; and Now is greatly flattened this sort of anywhere The a base its shape, while the pressure absolutely anomalous, and without precedent upon the column, being radial in But what has become of the be the infrabasals five inner plates resting position, must be taken basals It is plain to ? is by stronger as a result of this the base, reinforced by the outer circlet also, usually retains calyx above much to me that they are the so-called interradials, which, — not morphologically some strange freak of nature, have become displaced from their proper position by accidentally- in the calyx wall, being pushed and both having slipped down over the infrabasals Or, supposing a reverse process to have taken place, we may consider that in between the radials, CLEIOCEINUS the disturbance 105 came from below, the base being thrust upward calyx, expanding it between them, and the infrabasals into a ring formed It will into the until the radials were separated, the basals forced in of the two be remembered also that the radials are angular below, although with nothing whatever in their present position to meet their angles, or for them to rest upon The basals, on the other hand, are angular above, so that the inferior angular faces of the radials would upper faces of the basals we this idea in view, make room find that if between the sloping fit they were brought together If, therefore, with could stretch the Crinoid up from the column, so as to two for these they would fall within the calyx wall, we should into their relative positions without any difficulty circlets of plates be indicated by the accompanying diagrams, in which the plates in question are represented by dotted lines, Fig This imaginary process may — now, and Fig as they would appear as they are if placed in their proper position IE XJB^ V 1Br Fig This seems to on this Fig me tures so anomalous, upon any ) ' a reasonable explanation of the relation of these strucalthough I not find myself able to account for it — teleological or evolutionary basis phase of the subject to some my of I must look for enlightenment who have transatlantic friends, been admitted much farther into the mysteries of Phylogenesis than I The structure looks like one of those experiments which we sometimes encounter in Nature, and recalls the observation of Diderot in his " Pensees de lTnter- where he says " It seems that Nature has taken She pleasure in varying the same mechanism in a thousand different ways never abandons any class of her creations before she has multiplied the indipretation de la Nature," viduals of it in as many : different forms as possible." periment was a short-lived one, for it is At all events the ex- never heard of again It must be CLEIOCRINUS 106 remembered that Lower this Crinoid occurs in the lowest part of the Ordovician, or contemporaneous with the Cystids; and it may well be that it represents the end of some line of evolution in which the alternate successive arrangement of the skeletal elements has not yet been fully established, Silurian, — a consideration which may also be borne in abnormal orientation of the axial canal mind But the in connection with the fact that these plates of the exterior circlet, hanging to the outside of the calyx as were without it have just the angular faces to enable them to fit into their proper places in the normal succession, seems to me most wonderful Yet this case may not, after all, be much more anomalous than the con- visible office, should verse one of the Upper Silurian genus Calpiocrinus, where the stead of being within the circlet of basals, have overgrown infrabasals, in- them to such an extent as to completely envelop and conceal, not only the basals, but even sometimes the radials also SYSTEMATIC RELATIONS OF CLEIOCRINUS The prime is suggested by these observations on the actual specimens that Cleiocrinus is evidently an intermediate form between the Camerata and the fact Flexibilia, of a most interesting character concerned, the general habitus of the specimens its On articulate structure and flexible is So far as the calyx is that of an Ichthyocrinus ; calyx point strongly toward the Flexibilia the other hand, the presence of pinnules, and of five infrabasals instead of three, differentiate which all it palaeozoic forms of the chial structure known Flexibilia Impinnata, to group hitherto known belong The bra- absolutely from the — the form and arrangement of the ridges following the radial lines and running into arms and pinnules, with the arms is, as already — The suggested, essentially that of Gb/jitocrinus or Reteocrinus resemblance, superficial perhaps greater toward such a form as GlypL, Fig 13), but structurally the analogy is much closer although I not mean to be understood as claiming in this respect, is tocrinus dyeri (PI with Reteocrinus ; — that the two are actually at all closely related If we eliminate the interbrachial system from Reteocrinus, anals, we shall have substantially the calyx of Cleiocrinus all The except the dicyclic base with five infrabasals, the longitudinal series of anal plates extending almost to the margin of the disk, and the incorporation of pinnules within the calyx CLEIOCRINUS walls, are characters common to both 107 Of course the fixation of pinnules is accomplished in different ways, being in Reteocrinus by means of supplementand ary plates, while in Cleiocrinus it is simply by lateral union of brachials Aside from the great strengthening of the radial and anal the calyx of Reteocrinus is not so very much unlike that of Cleiocrinus pinnules series It is up of a large number of thin plates, evidently forming a pliant wall between the rays Its calyx was clearly pliant, and the disk conspicuously so I have more than a hundred specimens of R onealli which were preserved built in a very flattened, fine, soft, calcareous mud, and in almost every case the calyx and the disk more or were extremely flexible less bulging I a variety of shapes, as if it very small plates, unable, however, after close examina- It is really a thin without definite arrangement in is am integument of any trace of ambulacral the mouth The anal open- tion of a large series of well preserved disks, to find furrows upon the surface, nor of any opening for it is not conspicuous, and evidently ing is clearly indicated in some cases was often entirely closed, or concealed by the contraction or folding of the ; in tegument have figured a number of excellent specimens of 14 to 21) parison on these several points (PI I., Figs I large number this species, for A com- careful study of a good preservation, leaves no the assignment of the group to which they of these specimens, in unusually reason to doubt the correctness of subbelong to the Camerata The mouth and ambulacra are undoubtedly But it seems to me that they, with the addition now of Cleiocritegminal borderland closely approximating the Flexibilia, and should be This would accord with the opinion freconsidered as intermediate forms nus, lie in the who was quently expressed in private correspondence by P II Carpenter, much impressed by the strong resemblance of the Reteocrinida? to the Ichthyocrinidaj 108 CLEIOCKINUS DEFINITION OF THE GENUS The which I facts herein brought out necessitate a new definition of the genus, propose as follows : — Cleiocrinus Generic Diagnosis, amended large, conical, or pyriform ; pliant ; Base dicyclic infrabasals five, invisible exBasals and radials not in normal succession, but alternating with plates joined teriorly — Calyx Billings by loose suture ; each other in a horizontal ring of ten plates surrounding the infrabasals and projecting side No downward over the column interbrachials, except at the anal anals in vertical series, resting on truncate posterior basal, and ex- ; Bays and tending high up between the rays arms contiguous and interlocking their divisions up to the free brachials bifurcating several times in the ; which are incorporated by lateral union with adjacent brachials and become free between the arm bases Arms Column obtusely pentagonal, or nearly simple, uniserial, and pinnulate oft' calyx, giving fixed pinnules, round SPECIES — C regius from the genus I see calyx, and (' grandis and C magnificus from stem fragments only nothing to indicate any substantial distinction between the stems of C both being pentagonal, and the difference in size regius and C grandis, Billings described three species of this : — The stem fragment which he named C magnificuix Fig 3) is round, with proportionally much thinner not being very great (Dec IV., PI V., columnars, and of very large stem, where it seems to lose Fig 12 mentioned The — is its probably from the lower part of the In the angularity and become round It is another fragment, still larger, being over an inch also round the uncrushed part of it is figured on Plate new material there diameter, which size is ; large crown E (PI thirty inches long — in I., and the long stem already I., Fig 11), came from the same quarry, and may CLEIOCKINL'S 109 belong together This stem is similar to the two last mentioned fragments, and it, together with the crown E., may well be taken as an example of which no portion of the calyx has been seen before If no doubt a good species, and represents a mature development of C magnificiis, of so, it is The the type of C regius much can be made preservation of the calyx so poor that not is general appearance The proximal series of plates at the base are not well defined, but the arm bases are visible for of it its beyond a sufficient distance around to show that arms As it lies flattened, had it at least the top of the calyx at the and when one hundred free arm bases is fully must have been nearly four inches in diameter, one of the largest and most magnificent stalked Crinoids known The stem as preserved is thirty inches long, and was five inches in width, in its natural — form it probably six inches longer; it is five eighths of an inch in diameter at the upper end, and seven eighths at the root; very slightly pentagonal above, and round below than that of C composed of very thin columnars, much thinner there being about sixty to an inch generally, and It is regius, probably more near the The end distal The stem terminates obscurely pentagonal end axial canal at the upper is in a root similar to that of C regius The other two crowns are very much Specimen B-C (PI I., is the smaller of the two, and doubtless represents a younger It has but six arms to the ray, so far as can be observed, or about whereas specimen A has eight arms in most of the rays, or Figs a, b) stage alike thirty in all ; about forty in all If we had other specimens showing a constant differBut it ence in this respect, this might be ground for specific separation seems very probable that, as is often the case, there is considerable variability in the number of arms, which where one ray has only seven arms servation, but persistently ignored number of arms in Crinoids may be is, It indeed, indicated in specimen A, is a fact well established by ob- by some describers of species, that the a good specific character in some groups, and entirely worthless in others These two specimens have about the same form and proportions, being elongate conical and slender, whereas specimen E, with its enormous development of arms, although similarly flattened by pressure, is robust and greatly expanded, so that lower and wider it is proportionate])* Specimen B-C, therefore may be taken as another rep- resentative of C regius The two known species may much accordingly be defined as follows : — CLEIOCRUSTUS 110 Cleiocrinus regius Billings Calyx elongate conical, gradually expanding from the base to near the top, where it is slightly contracted plates flat and without ornamen; tation, arms tically except longitudinal ridges following the brachial series into the Infrabasals large and strong, invisible exteriorly; standing verupon the edge of the column, widest and thinnest above, succeeded they have a shallow groove at the middle of the upper edge Basals pentagonal, truncate below and angular above, except the posterior one, which is quadrangular, with perhaps a slight sloping at one corner; they lie between the radials, forming with by the directly them a their first primibrachs; which envelop the infrabasals by conceal them from view they also project horizontal ring of ten surfaces dorsal and downward over the column plates, ; for a short distance, without support at the Radials alternating horizontally with the lower margins of the plates basals, pentagonal, with the angular face below, and much smaller than the succeeding brachials Anals in a single vertical series, interlocking with adjacent brachials, and extending well up toward the arm bases the first one sloped at Primibrachs two, increasing in width upward ; the lower corners and widening rapidly upward the axillary primibrach ; followed by two to three bifurcations, giving six to eight arms to the ray, or thirty to forty in longitudinal rid