xt75hq3rv92n https://exploreuk.uky.edu/dips/xt75hq3rv92n/data/mets.xml Lyon, Sidney S. (Sidney Smith), 1808-1872. 1857  books b96-11-34699803 English A.G. Hodges, public printer, : [Frankfurt, Ky. : Contact the Special Collections Research Center for information regarding rights and use of this collection. Paleontology Kentucky. Pal5ontological report of Sidney S. Lyon text Pal5ontological report of Sidney S. Lyon 1857 2002 true xt75hq3rv92n section xt75hq3rv92n 















PALIEONTOLOGICAL REPORT


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S I D  :N7 EYY   S.



L Y O N ,



ASSISTANT GEOLOGIST.



59

 This page in the original text is blank.

 



                         CHAPTER I.

                      PAL&ONTOLOGY.

           DESCRIPTION OF NEW SPECIES OF ORGANIC REMAINS.
  During the progress of the Geological Survey of the State, many
new and interesting fossil forms have been discovered, which, with
those previously in the possession of the members of the geological
corps, of new and undescribed genera and species would, were they all
described and figured, make an extensive and valuable addition to the
science of Palaeontology. A few only of those most characteristic or
remarkable, for the present publication, have been selected. They form
but a small part of those deemed worthy of being carefully studied
and described.
  The sub-carboniferous limestone, the Coal Measures, and the tran-
sition beds of intercalated limestone near the base of the millstone
grit, of western Kentucky, abounds in fossils of remarkable and beau-
tiful forms. The living inhabitants and the dead individuals of those
ancient seas, both contributed, with the wasted materials of the subja-
cent lands, to the formation of the sedimentary strata then in process
of deposition which now serve as a guide to the student of Stratigraph-
ical Geology, pointing out with certainty the period and geological po-
sition of rocky beds wherever found, and with great certainty indicat-
ing equivalent geological measures, which, but for these truthful histo-
ries of the past, would never be recognized as of the same age-one
district presenting rocky masses, which in another are entirely changed
in physical appearance and chemical composition.
  In Crittenden county the sandstone of the millstone grit and asso-
ciated limestones have a great thickness downward, from the produc-
tive Coal Measures, to the principal mass of the sub-carboniferous lime-
stone on which it rests.
  At the distance of two hundred feet above the base of this mas of
sandstone is to be found a bed of earthy, calcareous, and shaley mate-
rials, one hundred and fifty feet thick. The lowest sixty feet of this
intercalated bed, is of a drab color, filled with innumerable fragments of

 



PALSONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



Retepera Archinzedes, spread out horizontally, and almost constituting
the entire mass. Further from the base of the bed are found segre-
gations, broken and irregular bands and patches of earthy ferruginous
limestone. This alternation of limestones and shale beds continues to
the top of the mass.
   It is from the segregated masses, at the top of the first sixty feet of
this intercalated calcareous bed, that some of the fossil forms selected
for description were obtained; and, so far as it is at present known, cer-
tain remarkable forms of this bed have never been found extending ei-
ther above or below its geological horizon.
   The vertical range of the first organic form which will be described
is not more than five or six feet. Two crushed specimens were found
in 1845; others, again, in 1852. Having recently obtained some
quite perfect specimens, it is proposed to describe them  under the
name of Peniremites obesus.

                          CRINOIDEA.
                   GENUS PENTREMITE&. Say.
  In the year 1820 the genus Pentremtites was proposed by Mr.
Thomas Say,' in which were placed certain fossil forms, then, for the
first time, described. Since the erection of the genus it has been gen-
erally recognized, and many species have been added by different au-
thors.  One of the latest authorities, Messrs. De Koninck and Le Hoc,
state the genus under the following formula, viz:
Basal pieces,       3, one less than the two others.
IRadial pieces,  1 X5, forked, large.
Interradial,     1 X5, small lanceolate.
Pseudambulaca, 1 X5,
Mouth,               1, central.
Anal,                I, lateral.
Ovarial openings, 2X5, situated around the mouth.
  By a careful examination of well preserved specimens, (not silicifi-
ed,) of the different species of this genus, including the typical spe-
cies. upon which the genus was founded, it may be seen that the formu-
la above quoted should be amended. Peniremilesjoreaiis,globo=s8, py-
eSen voL ii, Siiiialn; Journai, p. U, ad A sa JOni or Steiu  mad Arts, vl IL



468

 



PALZONTOLOGICAL REPORT OF GDOLOGICAL SURVEY.



rifornmk, and others, have severally three small plates or pieces, dis-
tinctly separated from the pieces heretofore designated as the "Bawal
pieces;" these three pieces form the base of the cup, and as they lie be-
low the pieces heretofore recognized as basal, are truekasal pieces, and
the others necessarily become first radials. It is therefore proposed to
amend the generic description, and the following formula is offered:
                    GENUS PENTREMITES. Say.
    Generic Formula:
Basal pieces,        1 X3, short, broad, and nearly of equal size.
First radial pieces,   X3, two hexagonal, perfect; one pentagonal,
                                   and imperfect.
Second radial pecies,  1 X5, nearly of equal size, long, forked.
Interradial pieces,  1 x5, small, lanceolate, nearly equal in size.
Pseudambulacrme,     I X5, long, filling the forked pieces, and ter-
                                   minating around the mouth.
Mouth,                    1, central.
Ovarial openings,    2 X 5, situated around the mouth.
  Column, cylindrical, perforated, segments luaeq size and thickness.

                   PENTREMITES OBESUS. Lyon.
                     (Pla.e Ir. fig. 1, I a, 1 6, I c, I d.)
  Body, elliptical half its heigbtb, rounded at the summit; the lower
part has the form of a broad inverted cone; the diameter is to the
heighth as 4 is to 5, (nearly.)  Basalpieces, of equal size, sub-quad-
rangular, of similar furm, low, broad; sides diverging upwards from
the columnar articulation; greatest heighth at the line of jucotion
with each other; irregularly concave, upper margin, into which the
first radials are fitted, regularly concave at their junction with the
column; when joined, they form a low cup, concave at the base, the
upper margin forming an unequal sided triangle.
  First radials two, of equal size, hexagonal; the third pentagonal,
and a little larger than half the size of the hexagonal pieces; this
unequal piece probably indicates the anal side of the pentremite;
the three pieces, when joined, present a broad shallow cup, the superior
margin of which is marked by five broad angular points, between which
are three angular, and two irregular, concave depressions, the latter
being upon the summits of the hexagonal pieces.



469

 


PALEONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



  Second radials five, divided two-thirds their length, swelling rapidly
from their junction with the first radials to the inferior end of the pseud-
ambulacral fields; twice as long as wide, the branches increasing in
width from theiL junction with the interradials toward the base; ob-
liquely truncated above, the truncation being by a sigmoid line, (not
straight as is usually the case,) meeting and fitting upon the inter-
radials by a lap, being beveled from within, the beveled surface being
about three times as long as the thickness of the pieces; abuttipg
Equarely at their lateral margins against each other, two resting upon
the complete hexagonal fist radials, and the other three resting upon
the beveled sides and in the notches formed by the junction of the first
radials; the line of junction of the sides occupies the center of a deep
elliptical grove.
  Interrudial pieces five, half as broad as long, (externally ;) angular-
ly pointed above, and roundly pointed below; 4 as long as the second
radials; within the body they are prolonged, and extended under the
second radials, and terminate in a long point on either side, forming
part of the wall of the pseudambulacral areas; the centre is also ex-
tended downwards and pointed, laping under the suture, marking the
junction of the second radial pieces.
  The interradials are marked by fine stria, (lines of increment,)
which conform to the external form of the piece in its different stages
of growth.
  The first and second radials are also marked by lines of increment.
In the first radials the lines conform to the sides and upper margins of
the pieces; the second radials are marked with lines extending entirely
around them, except around the margin of the fork, into which are
inserted the pseudambulacral fields.  All the pieces are divested of the
epidermis and muscular coat. The true external markings are un-
known.
  Pseudambulacral areas extend from the mouth, at the centre of the
summit, a little below the centre of the length of the body, gradually
increasing in width by a curved line on either side from below up-
wards, to the centre, when they diminish in width until they reach the
summit, they are composed of a double row of thin plates, about
twelve times as long as thick, about as broad as long, joined together
by their broad accs, terminating at the centre margin of the field, at a



470

 



PALZONTOLOOICAL REPORT OF GEOLOGICAL BURVEY.



foramen which divides these pieces; the divided sides of the foramen
pieces diverge slightly, and join a similar diverging side from an ad-
joining foramen piece, with which it unites and forms a ridge, which
continues to the margin of the field to which they are joined. The
field is divided longitudinally in the centre, by a deep groove, the fora-
men pieces are marked by a slight groove, which crosses them near the
centre of their length, and runs the whole length, dividing the field
into four bands. Where the foramen pieces are crossed by this slight
groove, they are frequently indented by a furrow, which sometimes con-
tinues the whole length of the pieces; it is frequently nearly oblitera-
ted, and then presents a rounded, oval, or lozenge shaped dent or hole.
These marks have the appearance of the imperfectly closed sides of two
pieces having grown together. At one state of their growth they
were, probably, in separate pieces. In the best preserved speci-
mens the broad faces are seen to be furrowed or grooved transversely;
the ends of these grooves are seen presenting small punctures, while the
sides of the grooves present a double row of little knobs, standing op-
posite each other, and joining the two adjacent pieces, which touch
each other at these ridges. The ends of the foramen pieces abutting
against the centre furrow of the field, are flattened and rounded, the
rounding on the inferior side of the piece being greatest. The flatten-
ed ends are ornamented by eight or ten diverging ribs, forming on the
ends of the pieces a series of beautiful fan-like ornaments, each slight-
ly concave. The foramen pieces number from sixty to seventy to the
inch-one specimen having one hnndred and fifty on each side of the
field; another (young,) having only forty-three, or eighty-six in each
pseudambulacral space.
  Mouth. The mouth is irregularly rounded, small externally, increas-
ing in size as the opening passes downward into the body; it is form-
ed of five pieces, lying immediately within the ovarial openings; it
was, doubtless, capable of being opened and largely expanded, by the
opening of the five petal-like parts into which the body is divided.
There is a deep indentation opposite to, and lying between, the lower
ends of the pseudambulacral fields; this indentation probably marks
the limit of the flexibility of the petals.
   Ovarial openings five, nearly round; one much larger than the oth-
era; the large opening on the point nearly opposite the -imperfect



471

 


472        PALEONTOLOGICAL REPORT OF GBOLOGICAL SURVEY.

first radial. Column cylindrical, formed of pieces or equal thickness,
articulating by radiated surfaces the rays covering the entire surface;
perforated; opening small; pentelobate; side arms at irregular inter-
vals, frequently opposite each other, formed of similar pieces to the
column.
   This species differs from all others heretofore described, being much
larger; the whole character is coarse and strong; the pieces are re-
markably thick-in the young, of a similar sized specimen, being
twice the thickness of any known species.  The general form is near-
est that of P. florealca. Say.
   Length of specimen under description,     -    -     2. 3  inches.
   Breadth of specimen under description,    -    -     2.    inches.
   Vertical circumference,       -     -     -    -     6.100 inches.
   Transverse circumference,     -     -     -    -      .6Q inches.
   In the largest specimen observed, the pseudambulacral field is 1.AQ,
inches; that of our specimen is 1.-45 inches; length of smallest spe-
cimen, one inch; the field of this specimen is IOF, (half an inch-)
   The pieces forming the pseudambulacral areas, are thiner than those
of the globosus or pyriforrnis, (small species.)

                   GENUS ASTEROCRINUS. Lyon.
   Gen. char.-Column, cylindrical, perforated; base, bilobate; prima-
ry radials five; secondary radials, first series, ten; second series, twen-
ty; lobe pieces, five; arms twenty, formed of a double row of joints.

                 ASTEROCRBNTS CAPITALIS. Lyon.
            (Plate III kg. 1,  a,Ib, I c, I d, I c, lf, lg, h  i, 1I1k.)
   Specific description.-Body, viewed from above, presents somewhat
 the form of an irregular five-pointed start; viewed in profile, erect, it
 has much the form of a Corinthian capital, slightly contracted near its
 base
   Column, cylindrical, composed of numerous, unequal-sized, thin, cir.
 cular pieces. The articulating facets are striated around their mar-
 gins-the elevated ridges of one joint fitting into corresponding
 depressions in those which adjoin it. At a short distance from the body
 these pieces re arranged into the column in sets of three, between two



Tw upe.-  a pred. i. slightly ced, therefore th star like Sre Ls not - rem h.

 


PAL.E )NToLOGIJ'AL REPORT OF GEOLOGICAL SURVEY.



quite thick pieces, those adjoining the thick pieces are quite thin, with
one much thicker between; nearer the body the pieces are alternately
larger and smaller; their edges are slightly rounded.
  Basal pieces, two of equal size, nearly alike; united they form a
shallow elliptical cup, the upper margin being indented by four concave
and two angular notches, svelling below the margin of the cup.  The
inferior surface presents an imperfect elliptical depression, in the centre
of which lies a deep circular pit, concave at the bottom; the outer mar-
gin of which is marked around its circumference by grooves and ridges,
by which it is joined to the column.
  Primary radials five, differing in form; the piece opposite the anal
side is slightly concave on the upper margin; the ends are nearly par-
allel to each other; twice as broad as high; the inferior margin is an-
gularly pointed-the point being about the centre of the width of the
piece, at which point it is twice as high as at the ends. The four other
primary radials are convex below, and fit into the concave indentations
of the basal pieces; they are low and broad; not quite as high as the
first pieces; two are concave above, the lower and upper margins being
nearly parallel; the other two have two concave depressions above, of
unequal size; the ends of the four pieces are obliquely diverging from
below upwards-the ends joining the anal piece having the greatest
divergency.
   Secondary radialls. These are in two series, the first consisting of
ten pieces, no two of which are alike; those resting on the first radial
opposite the an 'l side are convex below; as broad as high, the upper
margin of each having two concave indentations; the junction of these
pieces with each other is square, the opposite ends terminating in an
angular point.  The secondary radial pieces resting upon the first
radial piece, to the right of the anal piece, are terminated at both ends
by angular points; from one of these rise three secondary radials of
the second series ; from the other, only one.
   The next secondary radials to the light are, probably, broken, and in
our specimen are represented by four quadrangular pieces of unequal
size. The other four pieces are nearly of equal size, sub-quadrangular;
twice as broad as higb, having two concave notches in the upper mar-
gin of each.
   Secondary radials. The secondary radials are twenty in number;
                       60



473

 


474        PALE)NTOLO2LCAL REPORT OF GEOLOGICAL SURVEY.

nearly equal in size; sub-quadrangular; as broad as high. From
each of these the arm takes its origin.
  Anal piece. Lozenge shaped; small; rising from the smallest angu-
lar depression in the basal pieces.
  Lobe pieces. These remarkable appendages are five in number; un-
equal in size; thick, rounded, and club-like; twice as broad as thick at
the superior extremity, tapering downward, and ending in a broad fihn-
like manner, at the inferior extremity. They are divided into three un-
equal parts, the union of the parts being marked by sutures; the up-
per part not unlike a seed vessel, (when first discovered by the coun-
try- people these parts were supposed to be petrified seeds, and were call-
ed "petrified coffee-nuts;") it is more than one-third the length of the
whole lobe piece; with the middle piece it makes two-thirds the length;
the lower part is irregularly serrated, and marked by the impression of
muscular attachments; it fits into and is attached to the inside of the
basal pieces.
   Arms. Our species has twenty arms, in sets of four, rising from the
second series of secondary radials; they are composed of a double se-
ries of joints, beautifully articulating with each other-the salient an-
gles of one set filling the re-entering angles of the adjoining set; the
arms are regularly tapering from their insertion to the end, where they
terminate in a point, rising about one-fourth their length above the
highest poiut of the lobe pieces; each set is separated into pairs by
the lobe pieces, which embrace them on either side. It is not certainly
known that the arms are provided with cillia.
   This remarkable crinoid is found in the lower intercalated calcareous
 beds of the millstone grit of Crittenden county, associated with Pentre-
 mites obesus, 'Vc. The vertical range of this species is somewhat great-
 er than that of that fossil. It was very abundant; immense numbers of
 the fragments of the lobed pieces are found, especially of that part form-
 ing its upper extremity. It is evident that they were easily separated,
 for amongst the multitude of fragments only one specimen has been
 found sufficiently perfect to show the arrangement of the parts compos-
 ing it; this is slightly flattened by pressure, and is so much weather-
 ed that no surface markings can be discovered. By the fragments of
 the lobe pieces the lower intercalated limestone of the millstone grit
 may be identified.

 


PALSONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



  Its proportions are as follows:
     Heighth,       -     -     -     -     -     -     1.     inches.
     Greatest breadth across the lobe pieces,  -    1. -4 inches.
     Greatest breadth at the top of calyx-narrow
          side,     -     -     -     -     -     -       A0 inch.
     Greatest breadth at the top of calyx-wide
          side,     -     -     -     -     -     -      50 inch.
     Heighth of calyx,    -     -     -     -     -       .T46 inch.
     Heighth of radials,  -     -     -     -     -       .    inch.
     Heighth of basal pieces,   -     -     -     -       A    inch.
     Long diameter of basal pieces,   -     -     -       .I 4 inch.
     Short diameter of basal pieces,  -     -     -        -   inch.
  The genus Asterocrinus, by its lobed basal pieces, is allied to Dich-
crints, also by the number of its primary radials  Here the analogy
ceases. Dichocrinwes partakes much of the character of the Platycri-
nites. The primary radials are generally longer, and the calyx high;
the radials of all known species of Dichodrinus are higher than the
basal pieces, while in Asterocrinus the breadth of the radials are equal
to twice their bight.  In the remarkable lobe pieces it is distinguished
and separated from all known genera. It is evident the species under
consideration had no vaulted covering to the stomach, as the lobe pieces
rise from the basal pieces, (to which they are attached,) and nearly
fill the cavity of the body.  The lobe pieces are free, except at the
point of attachment at the base, were expansile, and are indeed aux-
iliaries of the arms, probably serving in part to sieze and crush its food.
Fixed to the base by a muscular ligament, articulating by joints, they
were evidently capable of opening with, or even independently of the
arms. Our specimen is closed; the arms are folded between the lobe
pieces. Six half sets of the arms have their entire length, and are
folded toward the centre of the summit, which they do not reach, leav-
ing the junctures of the lobe pieces exposed.
  In a paper read before the Academy of Sciences, at St. Louis, Mis-
souri, in 1857, our specimen is referred to, and classed with Dichocri-
nus; we differ from the author of tbat paper, and hold that our species
is essentially different, and should be separated from Dichocrnu/.



475

 


476       PALX3NTOLOG[CAL REPORT OF GEOLOGICAL SURVEY.

            ASTEROCRINUS ( 2 ) CORONARIUS. Lyon.
                          (Piatel  fig. 1,  I .)
  It is with a considerable hesitation that this remarkable and hitber-
to unknown fossil is refered to Asterocrin us, as it has neither basal,
radial, or arm pieces. This unique crinoidal fragment was found, with
others, associated with Pen/treiites obesus, Asterocrinusy capitalus, &c.,
in the lower intercalated ealcareous bed of the millstone grit of Critten-
den county. This specimen is evidently the summit and part of the
abdominal cavity and walls of a crinoid, and is prov isionally refer-
red to Asterocrinus, which it greatly resembles, by the arrangement of
the tumid star-like points; been in profile it resembles a ducal coronet
or crown. The body is pentagonal, having equal sides; the angular
corners are removed; an angular notch is provided, into which three
of the point pieces are inserted into the body. The point on the right
of the oral opening is joined to the body by an irregular line, nearly
straight; that on the left is joined by a curved line, with an angular
deflection near the side farthest from the mouth. The marginal bor-
ders of the pointed pieces are raised, and the pieces are fluted about
two-thirds their length; they are thick, heavy, and solid; curved on
the lower side, and when resting upon the upper surface, present the
appearance of a thick last, from  the instep to the toe. Within the
pointed pieces are arranged twenty-five polygonal pieces-those imme-
diately surrounding the mouth are convex, the others are concave; the
outer series are larger; two are hexagonal; the others are imperfect
rbombs; those within the point to the right of the mouth are small
and long ; the others are still smaller, of pentagonal, hexagonal, and
triangular forms. A few of the small pieces surrounding the oral open-
ing have been lost.
  Mouth, sub-central.
  Lower surfac. Between the pointed pieces are three angular prom-
inences, and four angular depressions; these are probably the articula-
ting surfaces to which the lower p art of the body and calyx were join-
ed; above these notches and prominences, and on the surface between
the pointed pieces are rounded and grooved impressions, probably pro-
duced by the pressure of the arms () 'No surface markings are found
on the specimen, which has evidently lost its dermal covering,-; they
would have been lost had they existed upon it

 


PAL.EONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



  Size of the specimen.    Length    of the pointed pieces. (the longest
piece,)    -                                                     inch.
  Length of the pointed pieces, (shortest piece,)       -       1050 inch.
  Longest diameter across the points,          -     -    1      inches.
  Longest diameter of body, upper side,       -     -      -17,-950 inch.
  Longest diameter of body, lower side,       -     -           inch.
  Height of body to junction of pointed pieces,     -           'u ich.
  Height of body to highest point of pointed pieces,        -5- inch.
  From mouth to nearest side,     -      -     -     -     T inch.
  From  mouth to most distant side,     -     -     -       150 inch.

          GENUS GRAPHIIOCRINUS.        DeKoninck and Lelon.
  De Koninck and LeIon, who established this genus, have given
the generic formula as follows, viz
  'Basal pieces,        5.
  Radial pieces,        2 X 5.
  Anal pieces,          1.
  Interradial pieces,     0.
  Arms,                10, not divided.

             GRAPHIOCRINUS-14 BRACHIALIS. Lyon.
                         (Plate I. fig 1, 2 a, 2b.)
  The anatomical structure of our species corresponds so nearly to this
genus that it is confidently referred to it.
   Column.   A short piece of the column, still attached to      our speci-
men, is composed of thin circular pieces, rounded on the margin, dif-
fering considerably in size-alternately a larger and smaller one
perforated ; the form of the perforation cannot be distinctly made out.
  Basal pieces five; long lanceolate; thick at the outer point; divided
by deep well defined sutures, from the inferior point of the primary
radials, to the opening of the columnar-pit, where the pieces join evenly
together; the superior points curved upwards, from the columns out-
ward; the pieces are grooved by a broad concave furrrow, which termi-
Fron the figure given hb De Koninck and LeHon, I have much doubt if these are th true
basil pieces  Species of kindred torin are 1 cud ith ifite basal piece. within the columnar de-
preonion; these lire generally covered by the colmn; always aIternating with the basal pie-
ces, as recogn.ized ill the above formula. There are another clas of crinoida bhving a pen-
tagoal baenl piece, not iudented, divided by fire sutures running from the columnar pit to the
seutre of the kides, forming the ptntagto. Za   Xaltss  i-r      in thut distin,
guishod.



477

 



PALSONTOLOOICAL REPORT OF GEOLOGICAL SURVEY.



nates at the commencement of the upward curvature of the points of
the pieces. The piece to the right of the anal pieces is larger than the
others, and the first primary radial rises from its truncated point; in
this respect the drawing is imperfect-the side toward the anal pieces
should be more elevated. The surface of all the pieces is smooth.
   Primary radials five; somewhat heart-shaped; concave above, round-
ly pointed below; the pieces on either side of the anal pieces are not
symetrical-the side of the left hand one having lost a portion of its
edge, against which rests one of the anal pieces, while that on the right
side has lost a portion of its inferior left margin, which joins the largest
anal piece.
  The primary radials of the second series are five in number; sub-
quadrangular; width, equal twice the greatest heigbth; differing in form
and size; sides square and vertical; swelling rapidly from the sides
toward the center; curved upwards on the superior margin, and termi-
nating in a rounded prominent knob, at or near the center of the
pieces.
  Secondary radials (axilary, Mliller,) ten; four are larger than the
others; similar in form to the primary radials of the first series invert-
ed; boldly prominent, each supporting two secondary radials of the
second series; the six others differ in form, and are less than half the
size of the first four, each supporting a single piece of the secondary
radials; slightly prominent.
  Secondary radials, second series, consists of fourteen subquadrangu-
lar pieces, differing slightly in size; less prominent than the first series,
from which the arms take their origin.
  Arms fourteen, composed of a double row of pieces, slightly rounded,
fitting deeply into each other-the salient angles of the right hand row
entering the retreating angles of the opposite row.
  Remarks.-Our specimen has been slightly crushed; the superior
ends of the arms are broken off; the calyx is remarkable for the depth
of the columnar depression, and the prominence of the rounded knobed
terminations of the pieces forming it, also, in having fourteen arms
the typical form of the genus having only ten. It was found in the
calcareous beds, near the base of the millstone grit of Crittenden coun-

 The primary radial. of the second series are bere equivalent to the sOpslar pieces of MUi -
Lw, corresponding to the -eIpulr pieces of Eremiln it4ron



478

 



PALEONTOLOOTCAL REPORT OF GEOLOGICAL SURVETY.



ty, associated with P. obesus, Asterocrinus capitalis, A. coronarius8, &c.
Ranging rather higher in the bed than either of the others. The verti-
cal range is not known. It has not, so far as we are informed, been
discovered in any other geological horizon.

                     A CTINOCRINUS. Miller.
  This genus was established by Miller in 1821, and was defined as
follows:
  "A crinoid animal, with a round column, perforated by a round ali-
mentary canal. At the summit of the column is placed a pelvis, formed
of three plates, on which five costals, and one irregular, adhere; which
are succeeded by the second costals and intercostal; and the scapulae,
from whence five arms proceed, forming two hands, with several tentac-
culated fingers.
  Round side-arms proceed at irregular distances from the column,
which terminates at the base in a fassicular bundle or roots of fibres."
  Recently De Koninck and De Hon, in treating of this genus, have
adopted a different nomenclature. The Aclinocrinus, as defined by
these authors, is as follows:
    Generic Formula:
    Basal pieces,     3, of a quadrangular form.
  Radial pieces,    3 X -5.
  Interradial pieces,  3X4-
  Anal pieces,       6.
  Brachial pieces,  1, or 2X5.
  Column, cylindrical; canal, pentagonal.

                ACTINOCRINUS ABNORMIS. Lyon.
                        (Plate IV. fig. 1, Ia, lb.)
   Body. The general form of the most symetrical of this species is
sub-globular; others are quite shallow; saucer shaped  with a very low,
irregular; covering in others the circle of the body, at the insertion of
the arms, is deeply emarginate. The form of the inferior part of the
calyx is constantly that of a shallow rounded cup, slightly indented
around the columnar pit.  The basal pieces, and the radials of the 1st
and 2nd series, are also constant characteristics.
   The superior surface has a continuous covering, composed of small
pieces; the spaces opposite the junction of the arms with the body have



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PALLEONTOLOGICAL REPORT OF GEOLOGICAL SURVEY.



generally prominent tubercles, usually rounded and low, sometimes
long and sharp-pointed; an additional knob or point usually marks the
summit, which is sub-central and near the anal side; around these
prominent pieces, are arranged, in a circular manner, small polygonal
pieces of various sizes, and the interspaces between these circular
patches are filled with pieces of irregular forms; in some of the
best preserved several knobs are joined by the interspace, having a
central piece, around which are arranged, circularly, small pieces-one
piece of the circle forming the connection between the centers of the
adjoining circles.
  Our description is that of a single specimen, differing in many par-
ticulars from all others of the species; yet it is believed that no accu-
rate observer could fail to reorganize every Apecimen of the species,
by features they have in common, which distinguishes them from oth-
er species.
  Basal pieces. The basal pieces, when undivided, presents an oblong
hexagonal space-the middle perforation being sub-central; when di-
vided, the sutures from the central opening terminate at the center of
the inferior margin of the alternate radial pieces of the first series; by
this division producing two pieces nearly equal in size, and one gene-
rally smaller than