Memoirs MCZ 2502

Its lowest ring of plates,described by Billings as resting on the column, consisted of ten plates,— five radially situate and five interradially,— which was so fundamentally different fr

With the compliments of

Comparative £00(00,11Frank Springer.

The genus Cleiocrinns was established by the eminent Canadian tologist, E Billings, in 1856,* to receive certain very peculiar Crinoids

diagnosis, a full description, with good figures, of C regius, the only species

in which the calyx was then known, and named two other species, C.grandis and C. magnificus, upon fragments of the column;—the main

the less relative thickness of the column joints.

The genus has been a puzzle to Crinologists ever since,—both as to

its actual structure and its systematic position Its lowest ring of plates,described by Billings as resting on the column, consisted of ten plates,—

five radially situate and five interradially,— which was so fundamentally

different from the calyx plan of all other known Crinoids that it was

impossible to assign a place for it without introducing hypothetical plates

within the proximal ring of Billings, concealed by the column pretations of the calyx based upon theories of this kind were none of them

Inter-satisfactory, and left the position and relations of the genus in much

doubt:

The stratigraphic position of Cleiocrinns renders it a form of specialinterest, because it is one of the earliest of known Crinoids It is asso-ciated with Blasioidoerinus, Palceocrinus, Hyboerinus, Carabocrinus, and otherprimitive forms, in an epoch when the Cystids were the prevailing Echi-

which Crinoids have been found It is considered to be approximately

*

Report Geological Survey of Canada, 1856, p 276.

94 CLEIOCRINUS.

equivalent to the Middle Bala of England, and to Stage d 4 of Barrande's

section of the Ordovician of Bohemia.

I have recently had the opportunity, thanks to the favor of Dr J. F

Geological Survey of Canada, with results of such extraordinary interest

my investigations were more especially directed.

Billings's account of the genus, as given in Decade IV., p. 52, is asfollows: —

"

Generic characters.—Cup, large, conical or pyriform ; basal plates, five;rays, five, alternating with the basal plates; the third plate of each ray

divided above Between two of the rays a single vertical series of azygos

interradial plates extends from the base to the margin of the cup. The

firmly anchylosed together by their lateral

"This genus has the structure of a Pentaerinus, with numerously dividedarms all soldered together in the walls of the cup."

Von Zittel in 1879 * referred the genus to the family Crotalocrinidoa

In the same year Wachsmuth and Springer! referred it to the ocrinidse, and discussed it as follows : —

Ichthy-"

The generic description was made from a single specimen, and this

was in several respects defective. Cleiocrinus has, according to Billings,five basals alternating with the radials, and forming with them a belt

In the typical specimen, the comparatively large column conceals from view

two series of plates, and analogy suggests that this may have been thecase. The five plates which Billings found alternating with the primary

radials. and which he called basals, are certainly interradials; and as the

* Eandb der Pal., I., p 357.

CLEIOCEINUS. 95

allied forms, we have good reason to suppose that it, like those forms,possessed five small basals and three underbasals, both hidden by the

the specimen is from the•Lower Silurian, where it is almost the onlyrepresentative of the family This alone induces us to try to definegeneric characters from a single imperfect specimen. Notwithstanding,therefore, that some of the elements are problematic, we propose until

"

Raised generic description.—"

Then follows a generic diagnosis based upon the probable presence of

three minute or rudimentary underbasals and five basals, all hidden by

In 1886* the genus was further discussed by us, and a diagrammatic

figure from the type specimen, made by Mr Walter R Billings, was given

infrabasals were indicated by dotted lines—thus giving the basal structure

of the Ichthyocrinidae generally A further revised generic diagnosis was

point being that the anal plates, instead of being four or five in number,

Billings, that "the ridges of the column are interradial in position, which

possesses underbasals, and that the so-called basals of E Billings areinterradials He also states that the lowest visible circlet of plates

'

shows that the base must have been concave, with ample space forthe basals and underbasals to lie concealed from view." We furtherstated:

" If

certain parts were better known, we should make it the type

of a new family, but at present, having no positive knowledge of thebasal regions, nor even of the arms, we are not in a position to give asatisfactory definition of the group."

Although E Billings had said, in his description of C. regius, that it had

"about forty . tentaculated, free rays," it was not understood that this

Billings sent to Dr Wachsmuth a drawing from another specimen of that

*

96 CLEIOCRINUS.

species, showing that the arms are fringed with closely packed pinnules

This pinnulate structure, if it had been appreciated at the time, would

Ichthyocrinidse, in which entire group pinnuleswere thought to be wanting

Von Zittel, in his Grundziige der Palaeontologie, 1895, does not seem tofind any place for the genus; nor does Eastman, in hisannotated translation

of the work in 1900

Bather, in Ray Lankester's Treatise on Zoology, Part III., p. 191, placesthe genus provisionally among the Flexibilia Impinnata, and gives the fol-

"IBB and BB hidden by stem; BR

small and separated by a large pentagonal interradial; arms isotomous

;

post IR supports a vertical series of anals, which reach the full length ofthe arms."

investi-gation of the group Flexibilia, to determine more definitely, if possible, thesystematic relations of this perplexinggenus, I applied to Dr.J. F. Whiteaves,

Assistant Director of the Geological Survey of Canada, for the loan of the

most obliging courtesy this material was placed at my disposal, and was promptly packed and shipped to me by Dr II. Ami, Curatorof the Museum,with valuable notes giving detailed information as to the history of each

both these gentlemen for the cordial interest which they manifested, and

their careful attention to my wishes: and I desire to here record my

an intelligent investigation of these unique fossils.

Decade IV., except 2a, and some importantadditional material since acquired

by the Canadian Survey The latter included a crown of very large size,

but poorly preserved, and a stem thirty inches long with the root attached

; also a fragment about seven inches long of a still

CLEIOCRIXUS. 97

to the fragment figured by him as lc, which is very important, as it shows most beautifully the real character of thearm structure As these specimens

call for extended study and discussion, I will, to avoid frequent repetition,designate them as follows:

A C regius. Billings's principal type specimen,—original of Figs, la and

16 of Plate V., Decade IV A splendid specimen, much flattened

above the base, but otherwise beautifully preserved, with calyx

com-plete and perfectly exposed on both sides, and having small portions

of the column and arm bases attached Billings's figure \<i shows

one side complete, but 16 gives the opposite view of the base only

(PI I., Figs 1 and 2).

B C regius. Original of Billings's Fig lc. Part of a column with two

Billings. Upper part of calyx and portion ofarms and pinnules;—

greatly flattened, but very perfectly preserved on one side. The

fractured edge adjoining B is not quite perfect, some small pieces

the original of Billings's fig. lg. Two of these are figured herein,

PL I., Figs. 3c 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

col-lecting ; and between 3d and 3c, where a piece is wanting The

basal portion of the cabyx,'being of very firm and rigid tion, was only slightly affected by pressure; but above, being

construc-flexible and composed of thin plates, it was flattened out, so as to

frac-ture and loss of parts of some plates when exposed in the quarry

where it was found

E C magnificus A very large crown, consisting of the calyx, witha very

small portion of the stem, and the bases of part of the arms The

surface of this specimen is very soft and friable, and it is

quite different from that of those

98 CLEIOCKINUS.

softer than the included fossils ; while in this the enclosing matrix

is harder, and not readily removable without carrying the surface

of the fossil with it (PL I., Fig 11).

F A large stem, thirty inches long, with the root attached It was found

be-lieve belonged to it; but a portion of the stem at the proximal end

ismissing, probably amounting to five or six inches

larger stem, similar to F (PI. I., Fig. 12).

STRUCTURE OF CALYX AND ARMS.

THE ARMS AND PINNULES.

The first observation of these specimens madeclearthe factthat thearms

are pinnuliferous,—a fact whichhas been overlooked in the discussions tofore ; although, as alreadystated, Billings, in his description of C. regius,

tentaculated, free rays."

The structure of the arms is perfectly shown by specimen C (PI. I.,

of short, wedge-form plates, each of which gives off a pinnule from the

originate on a bifurcating plate and lie closely alongside the outer arms ofthe ray,the plates of the two abutting and interlocking. Thesesubordinate

incorpo-rated in the calyx walls, and apparently become free between the arm

bases, though they are concealed from view by the regular pinnules. In

other interbrachial spaces higher up, from the last IIIBr or IVBr, and

All these are closely joined together and to the adjacent arms, and

incorporated into the calyx walls, until they reach the upper margin and

(PL I., Figs 1, 2), where the bases for a distance of several brachials are in

some places well preserved, having the pinnules attached,— though neither

100 CLEIOCRINUS.

THE CALYX.

successive brachials and between those of adjoining series, being marked by

small pits, or crenulations, indicating a union by a sort of articulation, orloose suture, such as we see in specimens of Forbesiocrinus In this respectthe structure is decidedly like that of the Ichthyocrinidae There is a com-

plete absence of any interbrachial system, except at the anal side, where avertical series of plates, originating on the posterior basal, rises high up between the arms, though not quite to the margin of the cup The main

are joined to each other by lateral union of their plates with those of theirfellows, and with the plates of the anal series. Billings fully appreciatedthis when in his generic description he noted as a feature ofthe structure ofthe genus its "

numerously divided arms all soldered together in the walls

of the cup." The plates are comparatively thin, and the mode of union

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 dent, from the manner in which they are flattened, that it was very thin

evi-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 thestructure and arrangement of the fixed pinnules, are very much like those

of Glyptocrinus and Rdeocrims; but the interbrachial system of those genera

is entirely wanting, —there being no supplementary plates, except at the

anal side, whose vertical series bears some resemblance to theirs. The

like that of Reteocrinus o' neatti and the Ichthyocrinidae.

Examination of the specimens as they were received did not seem to

B is obtusely pentagonal,—the exterior angles being interradial, which

pro-claims a dicyclic base (PI. I., Fig 3b). The axial canal in this specimen, at

with those of the exterior of the column (PI. I., Fig. 3/); which is a parture from the rule of alternation, and forms another minor exception to

de-CLEIOCRINUS. 101

the law ofWachsmuth and Springer, similar to that of Glyptocrinus

fornshetti,

; and what are the five plates lying between the radials '.'

Billings, with singular sagacity, called them the "true basals." His

description of C. regius (Dec IV., p 53), is as follows : "Atfirst sight there appear to be ten small basal plates, but upon examination

five of these are found to be the first plates of the five rays which rest

basal plates." Wachsmuth and Springer, having classed the genus with the

Ichthyocrinidte on account of the strong resemblance of its pliant calyx tothat of Icldhi/ocrinus, had supposed that it might possess the basal arrange-

ment of the group, viz., 5 basals and 3 infrabasals, both hidden by the

column; and they considered the pentagonal plates between the radials to

be interradials Since it now appeared that the genus is pinnulate, with anarm structure which differentiates it absolutely from all the known Pala?o-zoic Flexibilia, there seemed to me equally good reason to infer the presence

of five infrabasals, as in the base of the dicyclic Camerata

The superficial aspect of the specimens furnished no information on thispoint; and the only important fact gathered from the first examination of

overlap the

C regius both showed this very plainly; and they also showed the furthercurious fact that the five radially situate plates of this proximal ring,

least exteriorly, are distinctly angular below.

It wasapparent, 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

the column in either ofthem ; but after a very careful study of specimen B,

under a strong magnifier, I came to the conclusion that it 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

Bil-102 CLEIOCEIXUS.

lings's Fig 1 c the upper ring and some plates from the next ring above

shaley matrix If these could be removed, without destroj-ing the rest, we might see what lies next to the column The small size of the specimen,

and the uncertainty as to how the fractures might run, rendered .the tion a delicate and risky one to undertake with a type specimen ; but I

risk.

I accordingly laid the matter fully before Dr Whiteaves, and requested

his authority to undertake it. This he gave without hesitation, and in the

most liberal manner, leaving me free to act with the specimen as if it were

the personal confidence reposed in my judgment in so delicate a matter, but

also, in view of the important result attained, my thanks as a palaaontologist

to Dr Whiteaves for the benefit he has conferred upon science, by ing the means of information which, in my opinion, there was no hope ofobtaining in any other way I give this opinion, not only on account ofthe rarity of the specimens, but of their poor preservation In all othersthat I have ever seen the calcareous test is soft and friable, and the sur-

cleaning isimpracticable

The work of removing the necessary plates and debris from above the

base of the specimen was tedious and difficult, being performed entirely

of needles and fine steel pens. It was completely successful, however,

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

pen-tagonal; and around it, resting on the column and occupying its full ness,are five large, strong,quadrangular plates, sloping from within upward

thick-to a thin upper face, radial]?/ situate, which are followed by the first and

in the radial series is not, as a rule, visible at all from the interior when all