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STATE OF ILLINOIS
DEPARTMENT OF REGISTRATION AND EDUCATION

DIVISION OF THE
STATE GEOLOGICAL SURVEY

M. M. LEIGHTON. Chief
REPORT OF INVESTIGATIONS-NO. 21

A GROUP OF LARVIFORM CRINOIDS FROM LOWER

PENNSYLVANIAN STRATA OF THE EASTERN

INTERIOR BASIN

BY
J. MARVIN WELLER

PRINTED BY AUTHORITY OF THE STATE OF ILLINOIS

URBANA. ILLINOIS
1930

STATE OF ILLINOIS

DEPARTMENT OF REGISTRATION AND EDUCATION

M. F. Walsh, Director

BOARD OF
NATURAL RESOURCES AND CONSERVATION
M. F. Walsh, Chairman
Edsox S. Bastix, Geology
William A. Noyes, Chemistry
John W. Alvord, Engineering
William Trelease, Biology

Henry C. Cowles, Botany

Charles M. Thompson, Representing

the President of the University of

Illinois

STATE GEOLOGICAL SURVEY DIVISION
M. M. Leighton, Chief

Jeffersons Printing <t Stationery Co.
Springfield, Illinois

::<■;<>

Contents

Page

Bibliography 5

Introduction 7

Family Allagecrinidae 8

Genus Hybochilocrinus J. M. Weller, n. gen 12

Hybochilocrinus americanus (Rowley) ... 13

Genus Kallimorphocrinus J. M. Weller, n. gen 15

Kallimorphocrinus astrus J. M. Weller, n. sp 16

Kallimorphocrinus astrus typicus J. M. Weller, n. var 17

Kallimorphocrinus astrus intermedins J. M. Weller, n. var 18

Kallimorphocrinus astrus pyramidalis J. M. Weller, n. var 18

Kallimorphocrinus piasaensis J. M. Weller, n. sp 18

Kallimorphocrinus lilius J. M. Weller, n. sp 19

Kallimorphocrinus indianensis J. M. Weller, n. sp 20

Kallimorphocrinus vanpelti J. M. Weller, n. sp 21

Kallimorphocrinus infacetus J. M. Weller, n. sp 22

Kallimorphocrinus sp 23

Kallimorphocrinus pocillus J. M. Weller, n. sp 24

Kallimorphocrinus illinoisensis J. M. Weller, n. sp 25

Kallimorphocrinus knighti J. M. Weller, n. sp 26

Kallimorphocrinus expansus J. M. Weller, n. sp 27

Genus Aidemocrinus J. M. Weller, n. gen 28

Aidemocrinus odiosus J. M. Weller, n. sp 28

Family Hypocrinidae 29

Genus Lageniocrinus, de Koninck and Le Hon 31

Lageniocrinus cassidus J. M, Weller, n. sp 32

Genus Amphipsalidocrinus J. M. Weller, n. gen 33

Amphipsalidocrinus sissurus J. M. Weller, n. sp 33

Genus Tytthocrinus J. M. Weller, n. gen 35

Tytthocrinus comptus J. M. Weller, n. sp 35

Genus Dichostreblocrinus J. M. Weller, n. gen 36

Dichostreblocrinus scrobiculus J. M. Weller, n. sp 37

Plates and explanations 39

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BIBLIOGRAPHY

Text references to the bibliography are made by number, enclosed in brackets, thus —

[17, p. 10].

1. Bather, F. A., The Echinodermata ; Lankester's Treatise on Zoology,

Part 3, 1910.

2. Carpenter, P. H., and Etheridge, R., Jr., On Allagecrinus, the repre-

sentative of a new family from the Carboniferous limestone series of
Scotland ; Annals and Magazine of Natural History, 5th series, vol.
7, pp. 281-298, Pis. 15-16, 1881.

3. De Koninck, L. and Le Hon, H., Recherches sur les crino'ides du terrain

Carbonifere; Recueil des Memoires, l'Academie Royale de Belgique,
1854.

4. Jakovlev, N. N., Faune des Echinodermes du Permo-Carbonifere de

l'Oural a Krasnooufimsk I ; Bulletin du Committe Geologique de
1' U. R. S. S. vol. 45, pp. 51-57, PL 1, 1926.

5. Jakovlev, N. N., Faune des Echinodermes du Permo-Carbonifere de

l'Oural a Krasnooufimsk II ; Bulletin du Committee Geologique de
1' U. R. S. S. vol. 46, pp. 181-191, PI. 6, 1927.

6. Jakovlev, N. N., Sur la teratologic et la morphogenie des crino'ides

abrachiates ; Comptes Rendus de l'Academie des Science de 1' U. R.
S. S., pp. 313-315, 1928.

7. Rowley, R. R.. Description of a new genus and five new species of

fossils from the Devonian and Sub-Carboniferous rocks of Missouri ;
American Geologist, vol. 16, pp. 217-223, 1895.

>. Rowley, R. R., The geology of Pike County; Missouri Bureau of
Geology and Mines, 2nd series, vol. 8, 1908.

K Springer, F., Cystoidea, Blastoidea, Crinoidea ; Eastman-Zittel Text-
Book of Geology, vol. 1, pp. 143-226, 1913.

). Springer, F., On the fossil crinoid family Catillocrinidae ; Smithsonian
Miscellaneous Collections, vol. 76, No. 3, 1923.

11. Wachsmuth, G, Descriptions of two new species of Crinoidea from the
Chester limestone and Coal Measures of Illinois ; Illinois State Mu-
seum of Natural History, Bulletin 1, pp. 40-43, 1882.

12. Wachsmuth, C, and Barris, W. H., Paleontology of Illinois, Part 3;
Geological Survey of Illinois, vol. 7, pp. 339-345, 1883.

13. Wachsmuth, C, and Springer, F., Revision of the Palaeocrinoidea,
Part 3, First Section ; Proceedings of the Academy of Natural Sci-
ences, Philadelphia, 1885.

(5)

14. Wanner, |.. Die- permischen Echinodeimen von Timor, 1 Teil; I'aliion-

tologie von Timor, 6 Lieferung, 1916.

15. Wanner, J., Ueber armlose Krinoiden aus dem jungeren Palaeozoikum ;

Verhandelingen van bet Geologisch-Mijnbouwkundig ( jenootscbap
voor Nederland en Kolonien, Geologische Serie — Teil 5, pp. 21-35,
1920.

16. Wanner, J., Die permischen Krinoiden von Timor: Jaarboek van bet

Mijnwezen in nederlandscb Oost-Indie, Verhandelingen 1921, 3rd
Gedeelte, 1923.

17. Wanner, J., Neue Beitrage zur kenntnis der permischen Ecbinodermen

• von Timor, I Allagecrinus, II Hypocrinites ; Dienst van den Mijnbouw
in Nederlandscb-Indie, Wetenshappilijke Mededeelingen, No. 11,
1929.

18. Zittel, K. A. von, Handbuch der Pab-eontologie, vol. 1, 1876-1880.

(6)

A GROUP OF LARVIFORM GRINOIDS FROM

LOWER PENNSYLVANIAN STRATA OF THE

EASTERN INTERIOR BASIN1

By J. Marvin Weller

INTRODUCTION

Recent collections of Pennsylvanian fossils from Illinois, Indiana, and
Missouri have produced a most interesting assemblage of minute larviform
crinoids which are unique in comparison with previously known American
forms. The only descriptions of fossils with which they are at all compar-
able are of specimens collected from Lower Carboniferous strata in Scotland,
and Permian beds in the Ural Mountains, and the island of Timor.

The American specimens which are the subject of this article were col-
lected at three localities, namely, eastern Jersey County, Illinois, southern
Warren County, Indiana, and in the vicinity of St. Louis, Missouri. In
addition to these a single poorly preserved specimen was discovered in south-
western Vermilion County, Illinois. All of the specimens except the last
were discovered in the laboratory in the course of examining washed material
for foraminifera, ostracoda, and other minute fossils.

These tiny crinoids, the largest of which is less than two millimeters
in height, are associated with the abundant fragmentary remains of inoginate
crinoids of familiar Pennsylvanian types. It would be natural at first to
consider these specimens as representing immature stages in the growth of
some of the associated larger and more conventional species, but only a brief
examination reveals the fallacy of such a conclusion. The entire construction
of the little crinoids is quite distinct from anything previously known from
these strata. The most abundant type, for which the generic name Kalli-
morphocrinus is proposed (p. 11 ). is monocyclic and without anal plates. If
these represent the early stages of any common Pennsylvanian crinoids one
or more anal plates, as well as infrabasal plates, should be present. Further-
more, the radials in this genus are highly specialized arm-bearers having
articular facets suggestive of the Poteriocrinidae. In the majority of the
species these plates have developed longitudinal median angulations which
give the crinoid a pentagonal or star-shaped horizontal outline and furnish
a wider surface above for the articular processes. It is scarcely conceivable
that crinoids having such angulated radials could represent the youthful stages
of any known species of Pennsylvanian Poteriocrinidae. Also, the specimens
of those species which are known from more than a single individual are with
few exceptions quite uniform in size and similar in development. If these
specimens are immature individuals a gradational series should be obtained

1 It is with pleasure that I acknowledge the kindness of Mr. J. B. Knight, who has
placed in my hands the specimens of three species which he collected in the vicinity of
St. Louis, and my indebtedness to Professor J. Wanner of Bonn, Germany, for helpful
suggestions and direction to the literature.

(7)

8 I.ARVIFORM CRICOIDS

rather than a number of distinct forms, some of which are represented by
numerous individuals.

It is significant that the Indiana specimens occur at a lower horizon
than the Illinois and Missouri forms, which are from stratigraphically equiv-
alent beds, and are distinct specifically, indicating that these tiny crinoids
were short-ranged forms. Although the individuals obtained are compara-
tively few in number, they were probably very abundant, as in each case only
a small amount of material was examined. The occurrence of these tiny
crinoids at widely separated localities and at several horizons, as well as their
great diversity of form, suggest that they may prove valuable for strati-
graphic correlation, and the micropaleontologist who is concerned with the
Pennsylvanian formations may be required to include the Echinodermata in
his field of observation.

FAMILY ALLAGECR1NIDAE
In 1881 Carpenter and Etheridge published a description, accompanied

by two plates of excellent illustrations, of a group of very small and peculiar
crinoids collected from the Lower Carboniferous limestone of Scotland, and
proposed for them the name Allagecrinus aitstinii [2].1 They were unable
to assign these forms to any previously recognized family of the Crinoidea
and therefore instituted a new family, the Allagecrinidae. This group, which
was all included in the single species A. aitstinii, is diverse in character and
contains forms which differ from each other in such important respects that
they probably represent not only a number of different species but also several
generic types. Among the specimens studied by Carpenter and Etheri*
are three fairly complete ones which they considered to be adult. These are
figured on Plate XV which accompanies their article and the one represented
by figures 2a, b, and c, as it is the best preserved, should be considered as the
type, and from it rather than from the group as a whole the characters of
the genus may be known.

< >n Plate XVI of Carpenter and Etheridge's article are figured a num-
ber of specimens which were considered to be immature individuals belonging
to the same species as the "adult" forms. These smaller specimens all possess
an oral pyramid which is apparently absent from the "adult" specimens.
One individual of somewhat intermediate nature is shown in figures 7a and b
on Plate XV — this resembles the "adult" forms in general hut seems to
possess, sunken down between the radials, a small oral pyramid. This speci-
men is the only connecting link between the "immature" and "adult" forms
and had it not been found it would not have occurred to Carpenter and
Etheridge to join this whole group into a single species.

There are several important objections to considering the smaller forms
immature examples of the larger ones: (1) all of the "adult"' specimens
1 Bracketed numbers refer to bibliography, pp. 5-C.

LARVII'ORM CRINOIDS V

were obtained from a single locality whereas "immature" forms were col-
lected at a number of other places, and it is highly improbable that if these
were really immature specimens they should occur at most places without
"adult" specimens associated with them;2 (2) the "immature" forms are
too diverse in character to all belong to the same species ; (3) the plates which
compose the calyxes of the "immature" specimens are joined together so
solidly that they were not separated upon the death and decomposition of
the animals that formed them, but in the larval forms of modern crinoids
the plates are thin, porous, and not solidly joined together; (4) the specimens
in our collection, which strongly resemble some of. Carpenter and Etheridge's
"immature" forms, are mature as is shown by the fact that numerous speci-
mens of a single species are nearly all of uniform size and in the same stage
of development — if they were immature it is highly improbable that all of
the specimens should have died at the same stage in their development ;
(5) according to the interpretation of Carpenter and Etheridge the relative
size of the oral vault must have decreased with the growth of the crinoid
and at the same time the number of arms must have increased. Wanner's
study of a large number of specimens from Timor has shown that neither
of these suppositions is true but that the relative size of the oral dome and
the number of arms are constant characters among the various sized speci-
mens belonging to a single species [17, p. 10].

It is concluded, therefore, that the "immature" specimens are not con-
specific with the "adult" forms, and in this view Wanner agrees [17, pp.
10-11]. It remains to decide whether or not it is justifiable to retain them
in the same genus.

Crinoids that have been described as Allagccrinus are few in number.
From America there are A. carpenteri Wachsmuth [11, p. 40] which has
recently been removed to the genus Catillocrinus by Springer, [10, p. 28]
and A. amcricamts Rowley [7, p. 219] which is considered below in more
detail. Foreign species are: A. multibrachiatus, and A. uralcnsis Jakovlev
[5, pp. 184-185], and the variety of the latter nodocariiiatits, which should
probably be considered a distinct species, from the Ural Mountains ; and
A. indoaustralicus, A. jakovlevi, A. in flatus, A. acntus, A. procerus, A.
quiuquclobiis, A. cxcavatns, A. quinquebrachiatus and A. oruatits Wanner
from Timor [17, pp. 15-27].

The foreign species described by Wanner and Jakovlev are apparently
similar in most of their characters to those in our collections upon which
the observations in the following discussion are based.

The crinoids under discussion resemble A. austinii (as restricted to the
"adult" specimens of Carpenter and Etheridge) in two respects: (1) the

2 Professor Wanner states that J. Wright has collected more than 300 "immature"
specimens from bed No. 1 at Invertiel. Fife, and with them he found onlv one or two of
the "adult" forms. [17, p. 11, footnote.]

10 LARVIFORM CRINOIDS

dorsal cups are formed of a ring of low basals and five closely joined radials
with no sign of an anal structure; (2) the upper surfaces of the radials bear
well-developed articular processes and are extended horizontally into con-
spicuous muscle fields. But here similarities cease. The most conspicuous
difference is the absence of an oral crown in A. aitstinii. Carpenter and
Etheridge state that "there are no signs of its having been roofed over by a
closed dome or vault of any kind. Had such a structure existed within the
circle of radial plates, it would assuredly have been preserved in the original
of figure 2, together with the ring of first brachials." [2, p. 284.] If the
oral crown had formed as important a part in A. austinii as in our species it
would certainly have been preserved, as it is present in all of our specimens,
none of which possesses even the lowest brachials. Even if A. austinii passed
through a stage in its development when it possessed an oral crown similar
to that of some of the "immature" specimens, the fact that this oral crown
in the mature forms was no longer attached directly to the dorsal cup but
was separated from it by perisome is a distinction of generic importance
sufficient to separate it from species which at maturity retained the oral
crown firmly atached to the radials. A second conspicuous difference is the
unsymmetrical development of the radials in A. austinii, whereas in our
specimens pentamerous symmetry is nearly perfect. Even in A. jakovlcvi and
A. in flatus Wanner the axillary radials are only slightly wider above than
the radials bearing only one arm facet whereas below they are all of prac-
tically uniform width. A third point of difference is seen in the character
of the articular surfaces of the radials. Judging from Carpenter and Eth-
eridge's figures, A. austinii possesses a simple transverse ridge separating a
concave beveling of the outer edge of the radial, the dorsal ligamental fossa,
from the generally concave surface of the muscle field. The large opening
of the central canal occurs close to and often interrupts the transverse ridge.
This differs from our species in certain respects as may be seen by comparing
with the description of these structures presented on a subsequent page, as
well as by a comparison of figure Id on Plate II with figures lb and 6a of
Carpenter and Etheridge on their Plate XV.

The question as to whether any of these recently discovered species
should be referred to the genus Allagecrinus has been considered by Wanner
\ 17, pp. 11-12] who concluded that there is not sufficient basis for separating
them. However, Wanner took into consideration only two characters, num-
ber of arms and relative breadth of articular facets, and he is probably cor-
rect in his judgment that neither of these characters is of sufficient importance
to warrant a division. Nevertheless there are several other characters to be
considered. It is not known that Allagecrinus austinii (restricted) possessed
an oral dome attached to the radials and until it is established that such a
structure was present and was similar to the dome surmounting the more

LARVIFORM CRINOIDS

11

recently described species, doubt must remain. Aside from this point there
are two significant differences between A. austinii (restricted) and the other
crinoids. These are ( 1 ) the irregularly sized radials of the former, whereas
the radials of the latter are nearly of similar width even in those species
having axillary radials. The dissimilar radials in A. austinii would have
caused the oral vault, if present, to be distorted and unsymmetrical. (2) A.
austinii possesses five basal plates, but Wanner states that where the inter-
basal sutures are visible in the Timoran forms, the basal disc appears two-
fold, one suture lying in the right posterior radius and the other in the
anterior radius [17, p. 5]. It is probable that if any of the Timoran species
had possessed five basals Wanner would have observed the sutures in a few
at least of his numerous well preserved specimens. No basal sutures have
been seen in any of the American examples.

The Timoran and American forms differ notably from each other in two
respects. ( 1 ) In the Timoran species the opening of the axial canal is at
the center of and interrupts the cross ridge of the articular facet and in this
respect is similar to A. austinii. In the American specimens, however, the
opening of this canal is behind the cross ridge and in the bottom of the
depressed muscle field, thus differing from the Scottish form. (2) The oral
domes of the crinoids from Timor are in general star shaped and pyramidal,
sloping more or less uniformly outward and downward to the radials. The
individual oral plates are convex, the depressions along the interoral sutures
forming radial furrows converging toward the center of the crown. In these
furrows the arms lay when contracted. The Russian A. multibracJiiatus is
probably also of this type. On the other hand, the oral domes of the Amer-
ican species are rosettelike and flat topped, the outside of the orals descend-
ing .abruptly to the radials below. Rather indistinct and steep radial furrows
are present between the outer edges of the orals but these do not converge
toward the center of the crown and between them the upper surfaces of the
orals are distinctly concave. The Russian species A. uralcnsis and its variety
nodocarinatus are apparently also of this type.

An extended consideration of the facts presented above has resulted in
the conclusion that our species and probably those described by Wanner and
Jakovlev and the "immature" examples of Carpenter and Etheridge can not
be referred to Allagecrinus as typified by figures 2a, b, and c of Carpenter
and Etheridge's Plate XV. It is therefore necessary to erect a new genus,
Kallimorphocrinus, for a certain group having prominent oral crowns which
up to this time have been included under Allagecrinus and of which our
American species are typical. Whether or not the Timoran species should
be included in this new genus is undecided at present.

As a result of the restriction of Allagecrinus austinii to the "adult"
forms of Carpenter and Etheridge and the introduction of a new genus for

12 LARVIFORM CRIXOIDS

our tiny American species, the question arises — can these forms he referred
to the family Allagecrinidae ? The American species in structure and ap-
pearance closely resemble the pentamerously symmetrical examples described
from Timor. These in turn cannot, according to Warmer's opinion, he
separated generically ■ f rom multi-brachiate forms. Finally the dorsal cup
of A. jakovlevi, the most abundant many-armed East Indian species, closely
resemhles the less known A. austiiiii (restricted). It would appear therefore
to he most convenient, conservative, and probably correct to consider all of
these crinoids as members of a single family and consequently the new genus
KalUmorphocrinns is assigned to the family Allagecrinidae.

Wanner has been influenced by his observations on that peculiar series of
crinoids which he included in the family Hypocrinidae, to conclude that the
Timoran species referred to Allagecrinus are also the result of regressive evo-
lution and were descended from more complicated forms [17, p. 13]. Also
it is his opinion that the pentamorouslv symmetrical forms were derived, by
a reduction in the number of arms, from those possessing axillary radials
and as substantiating evidence he points out that in the highest Paleozoic beds
of Timor the five-armed species greatly predominate.

This argument loses its significance in view of the numerous American
lower Pennsylvanian species which are not accompanied by any forms pos-
sessing axillary radials. Moreover a proper understanding of the so-called
Allagecrinus onicriraiuis Rowley from the lowermost Mississippian reveals a
primitive type of calyx from which the later forms may have been derived
by progressive evolution. It appears therefore that Kallimorphocrinus, ex-
cept for its specialized articular facets and the absence of an anal plate, is
in other respects truly a primitive crinoid and was not derived by degenera-
tion from a more highly specialized ancestral type.

In view of its possible bearing on the ancestry of KaMmorphocrinus,
Allagecrinus amcricaiiits Rowley, which represents a more primitive hut allied
type, is here described. Because its peculiarities sharply differentiate it from
all other known crinoids, the new. genus Hybochilocrinus is introduced for
its reception. This genus is also assigned to the Allagecrinidae.

Genus HYBOCHILOCRINUS" J. M. Weller, n. gen.
Genotype Allagecrinus americanus Rowley
Monocyclic larviform crinoids which are composed of three rings of
plates as follows: (1) a basal disc the plates of which are rarely distinguish-
able— some specimens seem to indicate that the basals are three in number
one being somewhat larger than the others, but the orientation of this larger
plate is uncertain; (2) five nearly equally sized radials; (3) five orals, the

' vpos, humped; xeiXos, edge.

I.ARVIFORM CRINOIDS 13

posterior one being somewhat larger than the others, its inner angle extend-
ing between the anterior orals for a short distance thus completely separating
the two postero-lateral orals from each other. In addition to these three
rings of plates a single small anal plate rests upon the beveled upper left-
hand corner of the right posterior radial and extends upward above the
upper surfaces of the radials. The radials were all arm-bearing and in most
specimens only a single arm was present upon any one radial. A few rather
poorly preserved individuals may possess radials which are axillary but this
can not be stated as a certainty.

The single species for which this genus is erected is similar in a general
way to the forms of Kallimorphocrinus described on subsequent pages. It
is however a more primitive type as shown by the presence of an anal plate
which has been completely lost in the Pennsylvanian genus, and by the less
highly specialized arm facets. It is possible that these forms represent a
stage in the evolutionary history of Kallimorphocrinus.

Hybochilocrinus americanus (.Rowley)
Plate I, figs, la-c
1895 Allagccrinus americanus Rowley, Am. Geol. vol. 16, p. 219, figs. 3-10.

Louisiana limestone ; Louisiana, Missouri.
1908 Allagecrinus americanus Rowley, Missouri Bur. Geol. ser. 2, vol. 8, p. 67, pi. 16,
figs. 39-41.
Louisiana limestone ; Louisiana, Missouri.

The only previously known American crinoid which bears even remote
resemblance to the Coal Measures species of Kallimorphocrinus is Allagc-
crinus americanus Rowley from the Kinderhook beds of Pike County,

Fig. i
Plan of the calyx of Hybochilocrinus americanus

Missouri. For the sake of comparison with the Coal Measures species a
description of this interesting Lower Carboniferous form is here included.
The material available for study consists of about one hundred specimens
collected from the type locality in 1896 by Professor Stuart Weller.

14 LARVIKORM CRI -VOIDS

Description. — The calyx is very small, averaging about 1.3 mm. in height.
The height is considerably greater than the maximum width, giving the body
a general pyriform shape which varies in some specimens to truncated conical
or truncated sub-pyramidal. The radials constitute more than half the total
height and the basals make up somewhat more than half of the remainder.

The basal ring is circular in outline and enlarges slightly and more or
less regularly upward above the stem facet which occupies the entire proximal
surface. The surface of this portion of the calyx shows no indications of
sutures but one individual whose base was broken appears to have three basal
plates one of which is somewhat larger than the others. The basals of this
specimen apparently did not form a basal cup, but extended solidly to the
center.

The radials are elongated and wider above than below. Their height
is equal to twice their mean width or more. A broken specimen shows that
the plates are about .08 mm. thick. The radials are gently convex longitud-
inally and more strongly so transversely. The transverse convexity is either
regular, resulting in a circular cross-section of the calyx, or it is somewhat
accentuated along the central part of the radials. producing a calyx with
slightly flattened sides along the middle of which extend the interradial su-
tures. The distal surfaces of the radials bear the brachial openings and the
corners of the radials upon either side are more or less steeply notched pro-
ducing concave depressions into which the orals extend.

Rowley reported that in some of his larger specimens the radials are
axillary but this condition was not observed in any of our individuals ex-
amined. The specimens are all highly calcified and many of them apparently
more or less worn so that it is difficult to determine their detailed structure.
The best specimens examined, and these are all comparatively large examples,
did not possess more than one arm to a radial.

This species has no well developed articular facets similar to those of
Kallimorphocrinus. The position of the arms is indicated by n small suboval
or rectangular depression on the upper surface of each radial surrounded
by a thin lip which extends directly upward from the radial with whose
surfaces it is continuous. There is no beveling of the radial below this lip.
the outer portion of which is probably morphologicallv similar to the trans-
verse ridge in Kallimorphocrinus. The brachial openings surrounded by the
lips are directed straight upward and are very narrow and depressed owing
to the size of the oral crown which covers a large part of the ventral surface.
The general appearance of the brachial openings suggests that the arms of
this crinoid possessed no well organized supporting calcareous skeleton.

A subhemispherical oral crown surmounts the calyx and occupies the
greater part of its ventral surface. It is composed of five plates of which
the posterior one is the largest, being both wider and longer than the others.

LARVIFORM CRINOIDS

15

The outer border of this plate is not as uniformly convex as the others but
possesses a shallow concave indentation near the center in which the anal
plate fits. The upper surfaces of the four small oral plates bear shallow
indistinct concave depressions and the larger posterior plate has two some-
what narrower but otherwise similar depressions.

A peculiar structure at the upper left-hand corner of the right posterior
radial is commonly well shown by the larger specimens, although in a few
smaller individuals this is definitely not developed and pentamerous symmetry
rules. The majority of the crinoids however are so poorly preserved that
its presence or absence can not be determined with certainty. The upper
right-hand portion of this radial bears a brachial opening of the usual type but
the left-hand corner is distinctly beveled and meets the next radial at a
position some distance below its upper surface. The inner surface of this
beveled corner slopes steeply inward and downward from its sharply angular
outer edge, apparently forming an opening that leads into the interior of the
calyx beneath the oral crown. A very few specimens, instead of a beveled
corner of this radial, show in this position a rounded projection extending
above the upper surface of the radial nearly to the height of the top of the
oral crown. Although no suture is visible there is little doubt that this pro-
jection is a separate plate which has been lost from most specimens. Rowley
did not notice such a projection of one of the radials but he suggested that
the beveling of the corner of the radial might represent the anal area. This
extension of the upper left-hand corner of the right posterior radial probably
represents a radianal plate which has been pushed upward and nearly out
of the calyx. The specimens show no indication of an anal opening and. it
is probable that the rectum was situated within the oral plates which were
capable of being opened during the life of the crinoid.

The surface of the plates of these crinoids is unornamented and was
probably smooth. The specimens show minutely pitted surfaces but this
may be due to wear or to slight solution.

Remarks. — This species is structurally distinct from all other known
crinoids.

Occurrence. — This tiny crinoid is known only from a shale parting in
the Louisiana limestone at Louisiana, Pike County, Missouri.

Genus KALLIMORPHOCRINUS4 J. M. Weller, n. gen. ,
Genotype Kallimorphocrinus astrus typicus J. M. Weller, n. sp., n. var.

Monocyclic larviform crinoids of fairly perfect pentamerous symmetry,
copiposed of three rings of plates: (1) a low disc of anchylosed basals ;
(2) five, high, nearly uniformly sized radials; and (3) five petaliform orals.

4 KaWi/wp^jos, beautifully formed.

16 I.ARVIFORM CRINOIDS

The upper sides of the radials, which are perhaps axillary in a few species,
usually hear well-developed articular processes and extend horizontally inward
as prominent muscle fields. The articulation consists of a strong transverse
ridge helow which the radial is more or less sharply beveled, and in a few
specimens a small ligamental pit is visible near the center of the outer side
of the ridge. Extending inward from the ends of the transverse ridge and
separated from it by shallow grooves are two strong radial ridges inclosing
a concave area or muscle field near the middle of which is the small opening
of the axial canal. The ventral surface is covered by the oral crown which
rises strongly above the radials. The oral plates alternate with the radials
and their upper flattened surfaces are broadly and shallowly concave. The
ambulacral openings are between the orals at a position slightly above the
the upper surface of the radials. The oral plates are nearly uniform in size
but the posterior plate may be distinguished by the fact that it adjoins both
the right and left anterior orals near the center of the crown, thus separating
the right and left posterior orals from each other. The posterior oral is a
madreporite and its minute perforation may be seen on well preserved in-
dividuals. On some specimens a tiny pustule marks the position of this pore.
The arms and the stem beyond its uppermost joint, which in many specimens
remains attached to the calyx, are unknown.

The species Kallimorphocrinus astrus as represented by its typical va-
riety is selected as the genotype, several well preserved specimens of which
are included in our collections. This variety is an extreme representative of
the genus characterized by its pronounced star shape which has resulted from
the. development of the angulation of the radials producing wide and com-
paratively short articular facets. The other extreme is represented by A'.
pocillits with its lobate horizontal outline. The articular facets of this latter
species are much longer than in the genotype and the description of their
characters has largely been made from an examination of this species.

The specimens of Coal Measures Kallimorphocrinus exhibit considerable
diversity of form and ornamentation on the basis of which they are divided
into ten species.

Kallimorphocrinus astrus J. M. Weller, n. sp.

In the collection from the Indiana locality the majority of the small
crinoids that belong to this genus form a rather variable series and it has not
been found practicable to subdivide them specifically. One of the conspicu-
ous end members has been selected as typical and two members of the prin-
cipal series are described as subordinate varieties. As may be seen from
figures 2a, 3a, and 4a on Plate I. the prominence of the spinelike processes
of the radials varies regularly as the diameter of die basal stem facet and
inversely as the height of the basal disc. In addition to the three described

LARVIFORM CRIXOIDS

17

varieties the collection contains several other forms most of which are smaller
than the figured varieties so that it is not certain that they are mature in-
dividuals and for that reason they are. not considered here.

Kallimorphocrinus astrus typicus J. M. Weller, n. var.
Plate I, figs. 2a-c

Description. — The height of the holotype is 1.07 mm. and its maximum
width is somewhat greater. Its horizontal outline is decidedly star shaped
with rounded corners separated by broadly concave sides. The radials form
about three-fourths, the underlying basal disc one-twelfth, and the crowning
orals about one-sixth of the total height. Some specimens possess a thin
stem joint firmly attached to the basal plates.

The basals are firmly anchylosed into a low basal disc which slopes
regularly upward and outward to the suture which separates it from the
radials. It is pentagonal in outline and its upper and outer edge is beveled
for the reception of the radials. The circular stem facet occupies the whole

O0O06

Fig. -1

Plan of the calyx of Kallimorphocrinus
astrus

lower surface of the basal disc, is slightly concave, and is pierced by a single
small central opening.

The radials are of similar size and form, subrectangular in outline but
somewhat wider above than below. Their height is about twice their mean
width. At their bases the radials are evenly convex but almost immediatelv
a rounded central keel is developed which becomes more prominent upward
owing to a widening of its flat lateral slopes. This angulation culminates
above in a prominent rounded knob the top of which bears the articular facet
for the arm. The upper corners of the radials are rather strongly beveled
and rounded, producing between the radials broad concave depressions in
which the orals rest.

The articular facets of the radials are much smaller than in K. pocilhis.
In few specimens are the details of this structure recognizably preserved
but some specimens show a concave depression in the center of which lies the

18 LARVirORM CRIXOIDS

small opening of the axial canal, and on the whole they seem to he entirely
comparable to those of K. pocillus.

The orals are relatively large and form a five-lobed flat-topped crown
which rises abruptly above the radials. The outer portions of the sutures
which divide them lie in broad concave depressions and the outer portions
of the orals slightly overhang their junction with the radials below.

The best preserved individuals of the K. astnts series are minutely pitted
and as they are very perfectly silicified there can be little doubt that this
represents the original spicular structure of the plates which were somewhat
porous.

Occurrence. — These specimens were collected from a limestone near the
base of the Pennsylvania!! section near the center of the N. ^ sec. 35,
T. 21 N., R. 9 W., Warren County, Indiana.

Kallimorphocrinus astrus intermkdius J. M. Weller. n. var.

Plate I, figs. 3a-c

This variety differs from the typical one in having its greatest width
approximately equal to its height. The basal stem facet is smaller, the basal
disc higher and the knob-like processes of the radials are much less developed
so that the horizontal outline is nearly pentagonal.

Occurrence. — Same as the typical variety.

Kallimorphocrinus astrus pyramidalis J. M. Weller, n. var.

Plate I, figs. 4a-c
This form is furthest removed from the typical variety of the K. astrus
series. Each of the changes noted in the variety intermedins has progressed
still further. In this form the height is greater than the width, the basal disc
is higher, the stem facet smaller and the knobs on the upper part of the radials
only slightly developed.

Occurrence. — Same as the typical variety.

Kallimorphocrinus piasaensis J. M. Weller, n. sp.
Plate I, figs. 5a-b

Description. — The height of the holotype is 1.02 mm. and is equaled by
the greatest width. The horizontal outline is star-shaped with slightly rounded
angles and concave sides. The radials form a little over two-thirds, the
basal disc one-ninth and the oral crown one-sixth of the total height of tin-
calyx.

The basal disc is subpentagonal as viewed from below and has a diameter
equal to slightly more than one-fourth of the greatest width of the calyx.
The plain sides of the disc slope outward and upward from the stem facet

LARVIFORM CRIXOIDS

19

which occupies its whole lower surface. The radials rest in scallops which
indent the upper and outer edge of the disc.

The radials have a height equal to twice their mean width and are about
twice as wide above as below. They are extended into a median longitudinal
angulation which rises abruptly from the general curvature of the calyx at
the base of the radials and becomes increasingly prominent upward. The
lateral slopes from the angulations of adjoining radials meet at the suture
to form the sides of the calyx which becomes increasingly concave upward.
The angulations of the radials terminate above in slightly expanded knoblike
processes or are terminated by the beveling which leads upward to the arm
facets. The upper corners of the radials are r.ounded off and at their junc-
tures are concave depressions into which the orals extend.

The articular facets of the radials are not well preserved in the single
known specimen of this species.

The oral crown rises strongly above the radials and slightly overhangs
the dorsal cup interradiallv. The upper surface of each plate bears a broad
shallow depression and a small pustule marks the position of the madrepore
in the posterior radial.

The surface of the calyx is marked by closely set, very minute pits which
probably indicate that the plates were originally porous.

Remarks. — This species is distinguished from K. astrus by its stellate
outline which is unaccompanied by prominent radial knobs, and by its more
coarsely pitted surface.

Occurrence. — The holotype was obtained from shale immediately under-
lying the Piasa limestone"' near the center of the NE. 34 sec. 25, T. 8 N.,
R. 10 W., Jersey County, Illinois.

Kallimorphocrinus lilius J. M. Weller, n sp.
Plate I, figs. 8a-b

Description. — The height of the holotype, not including the stem joint
attached to its base, is .81 mm., which is slightly less than the greatest width.
A horizontal cross-section through the upper part of the radials is like a
five-rayed star with somewhat rounded points. The radials form about five-
eighths, the basal disc one-eighth, and the oral crown a little more than one-
fourth of the total height.

The basal disc slopes outward and upward and supports the radials on
its upper beveled edges. Its flat circular basal facet is completely covered
by a stem joint.

The radials are considerably wider above than below and their mean
width is somewhat greater than half their height. A longitudinal keel occu-

5 The Piasa limestone occurs about 20 feet above the limestone cap-rock of the Herrin
]\o. 6 coal. It is correlated with one of the limestones of the Henrietta formation of
Missouri and Kansas.

20 LARVIFORM CRINOIDS

pies the center of each radial, becoming sharper and more prominent above
and terminating in a small, narrowly rounded or subangular knob. The upper
corners of the radials are beveled, forming rounded depressions in which
the orals rest.

Articular processes are not preserved on any of the radials. Their area
is quite small and but little wear would be required to obliterate them.

The oral plates rise sharply above the radials and form a gently convex
crown each of whose five lobes overhangs the calyx below. Shallow concave
depressions occupy the upper surfaces of the orals.

The surface of the holotype is smoothly polished but completely covered
by minute irregularities which can be seen only when the specimen is mag-
nified some twenty-five or more diameters. This probably does not represent
original ornamentation of the surface but is due to a very slight amount of
solution.

Remarks. — This species, which is based upon a single individual, is quite
similar in a general way to some forms of the K. astrus series, but in its
combination of characters it differs from any of the K. astrus forms examined.
This is particularly true in regard to the higher basal disc and less prominent
knoblike processes of the radials in an individual whose width is greater than
its height, and also in the comparatively larger and more overhanging oral
plates. It might be questioned whether these distinctions are sufficiently
important to justify specific discrimination from the K. astrus series, but
they probably are, inasmuch as A'. lilius occurs at a considerably higher
horizon.

Occurrence. — The single specimen of K. lilius was collected by Air. J. B.
Knight from calcareous shale immediately below the Piasa limestone in the
hollow just north of the right angle west turn of Scheute Road, half a mile
southwest of Lackland Station on the Chicago. Rock Island and Pacific
Railway and three quarters of a mile north of Stratman, St. Louis County,
Missouri.

Kallimorphocrinus indianensis J. M. Weller, n. sp.
Plate I, figs. 9a-b

Description. — The holotype is 1.41 mm. in height, of which the radials
form about three-fourths. The greatest width is somewhat less than the
total height, being approximately equal to the combined height of the basal
disc and radials. A cross-section through the upper part of the radials is
nearly pentagonal, with only slightly concave sides.

The basal disc is low and broad. Its height is about one-tenth of the
total height and its width somewhat less than half the greatest width of the
cup. It slopes gently outward above the circular stem facet which occupies
its whole proximal surface.

LARVIFORM CRIXOIDS 21

The radials are elongated and are wider above than below. Their height
is somewhat more than twice their mean width. A sharp angulation occupies
a central position, rising from the general curvature of the basal disc at the
base of the radial, becoming stronger and more prominent upward, and ending
above in the articular facet. Upon either side of the articular facet the radials
are beveled, producing gently concave surfaces into which the orals extend.

The articular facets are strong and well developed although they occupy
only about one-third the upper width of the radials. The angulations of the
radials are beveled above, producing triangular facets which rise to the trans<
verse articular ridges. Behind each transverse ridge and at the bottom of a
concave area bounded by radial ridges is the opening of the axial canal.

The orals are prominent though not overhanging and form a five-lobed
crown rising above the radials. Their upper flattened surfaces are shallowly
concave. The ambulacral openings penetrate between the orals at a position
about midway above the articular surfaces of the radials.

• The surface of this specimen which is entirely silicified is very uneven.
Although this may be the result of alteration, it is probably due, at least in
part, to the original structure and porous texture of the plates.

Remarks. — This species which is based upon a single specimen is so
distinctive that it is unnecesary to compare it with the other forms described.

Occurrence. — The specimen is from dark limestone near the base of the
Pennsylvanian strata in the center of the N. l/2 sec. 35, T. 21 N., R. 9 W.,
Warren Count}-, Indiana.

Kallimorphocrinus vanpelti J. M. Weller, n. sp.

Plate I, figs. 6a-b
Description. — The height of the holotype, exclusive of the stem joint
attached to the calyx, is 1.30 mm. and is equalled by the greatest width. The
radials make up three-fourths, the basal disc about one-ninth, and the oral
crown about one-sixth of the total height of the calyx.

The entire lower surface of the basal disc is occupied by the stem facet
above which the disc enlarges very slightly to its scalloped upper border upon
which the radials rest. The diameter of the basal disc is equal to about half
the greatest width of the calyx.

The radials are subrectangular in outline and only slightly wider above
than below. They are about twice as high as wide. Median angulations
developed longitudinally on the radials become progressively more prominent
above and are terminated by subtriangular beveled surfaces which rise to the
transverse ridges of the articular facets. The upper corners of the radials
meet in shallow concave depressions occupied by the outer edges of the orals.

22 LAHVIFORM CBINOIDS

The articular facets are well developed and strong, consisting of the
prominent transverse ridge behind which lies the concave depression contain-
ing the opening of the central canal.

The orals rise strongly above but do not overhang the radials. Their
upper surfaces are shallowly concave and the posterior one bears a small
pustule marking the position of the madrepore.

The surface' of the calyx and particularly that of the radials is very
rough and uneven and bears numerous small, irregular, closely set spinelike
processes. The depressions between them are filled with a brownish argilla-
ceous matrix so that it is impossible to determine whether or not the plates
are porous. The surface however strongly suggests that they were composed
of a comparatively coarse spirillar intergrowth which was not completely
transformed into solid plates.

Remarks. — It is unnecessary to compare this species with any other as
its rough and irregular surface is entirely distinctive.

Occurrence. — The holotype was obtained from shale occurring just below
the Piasa limestone near the center of the NE. *4 sec. 25, T. 8 N., R. 10 \\\.
Jersey County, Illinois.

Kallimorphocrinus infacetus J. M. YYeller. n. sp.
Plate II, figs. 4a-b

Description. — The height of the holotype i^ 1.37 mm., which is only
slightly greater than the greatest width, and the diameter of the basal stem
facet is about one-half the greatest width. The radials make up about seven-
tenths, the basal disc one-tenth, and the oral crown one-fifth of the total
height. The outline as viewed from above is roughly pentagonal but the
symmetry is interrupted by the irregular development of the arm facets.

The basal disc is low and broad and slopes slightly upward and outward
from its large stem facet. Its upper edge is beveled for the reception of the
radials.

The height of the radials is a little less than twice their mean width and
they are considerably wider above than below. The angular median keel
begins at the lower extremity of the radial and becomes more pronounced
upward until it ends in the articular facet. The sloping sides of adjoining
radials meet at the suture and form the slightly concave or nearly flat sides
of the calyx. The upper corners of the radials are slightly beveled, produc-
ing shallow concave notches between the arm facets.

The articular processes of the radials are rather unequally developed.
They are in general large and well formed and show the same features noted
in A", pocillus. On the holotype, however, no articular process is present on
the anterior radial which perhaps was not arm-bearing, but it is also possible
that the structure has been obliterated by wear. In anv case this rav is the

LARVIFORM CRIXOIDS

23

least developed, a condition that has also been noticed in specimens of certain
other species.

The oral crown is rather flat and rises abruptly from the radials. In
diameter it is only slightly larger than the basal disc and it does not wholly
cover the ventral surface of the cup. The individual plates are shallowly
excavated and the posterior one bears a pustule indicating the position of the
madrepore.

The surface of the holotype, which is a silicified specimen, is minutely
pitted. This probably represents the original porous structure of the plates.

Remarks. — This species resembles K. pocillus in size, in the small oral
crown, and in the large and strong articular processes. However, its general
form, produced by the angulated radials, serves to distinguish it from the
other which is composed of convexly rounded radials.

Occurrence. — The holotype is from a limestone near the base of the
Pennsylvanian section near the center of the N. ]/i sec. 35, T. 21 N., R. 9 W.,
Warren County, Indiana.

Kallimorphocrinus sp.

Description. — The calyx of this poorly preserved specimen is a little
less than 1.5 mm. in height and the greatest width is somewhat less. The
radials form about two-thirds, and the basal disc and oral dome each make
up about one-sixth of the total height of the calyx.

The basal disc has a diameter equal to about two-thirds of the greatest
width of the calyx and is only slightly larger above than below.

The radials are subrectangular and only slightly wider above than below.
Their height is about twice their width. Each radial is medianly angulated
and the surfaces slope off on either side to meet the adjoining radials and
form the flat lateral sides of the calyx, giving the whole body a truncated
pyramidal form.

The articular facets of the radials are largely obliterated and none of the
details can be made out.

The oral crown is subhemispherical in form and does not overhang the
radials. Its diameter is about equal to that of the basal disc.

The surface of the calyx is badly worn or weathered. Its uneven rough-
ness suggests that the plates are spicular and porous.

Remarks. — This specimen most closely resembles K. indianensis but its
basal disc is much stouter and it lacks deep notches at the upper corners of
the radials. It occurs at a much higher horizon and is probably a distinct
species but it is impossible to adequately characterize it from the single im-
perfect specimen obtained.

Occurrence.- — This specimen was collected from a thin layer of argilla-
ceous limestone beneath the thick quarry bed near the south end of the large

24 I.ARVIIORM CRINOIDS

quarry about two miles south of Fairmont, Vermilion County, Illinois. The
exact position of this limestone with regard to the standard Illionis section
is not definitely known but the horizon is not far from that of the Lonsdale
limestone" although it may he somewhat higher.

Kallimorpiiocrinus pocili.us J. M. Weller, n. sp.

Plate II, figs, la-d

Description. — The calyx is small, the greatest diameter being somewhat
less than the height which is 1.48 mm. in the holotype. The horizontal outline
is distinctly five-lobed owing to the convex form of the radials whose lateral
slopes form broad, more or less deep concavities along the centers of which
lie the sutures. The radials form about seven-ninths, and the underlying
base and the crowning orals each form about one-ninth of the total height.
Beneath the base in some of the specimens occurs a thin stem-joint firmly
attached to the calyx.

The basals are firmly anchylosed into a low basal disc which slopes gently
outward to the slightly excavated suture separating it from the radials. It is
nearly circular in outline but is beveled above by five inclined planes upon
which the radials rest, thus giving it a somewhat pentagonal appearance. The
stem facet occupies the whole lower surface of the basal disc. It is nearly
circular, large, with a diameter only slightly less than half that of the calyx,
and was probably pierced by a single central opening.

The radials are subrectangular in outline, nearly twice as high as wide,
and approximately equal in size. Their outer surfaces are convex both hori-
zontally and vertically. The vertical convexity occurs chiefly in the lower
half and thus the greatest diameter of the calyx occurs at about mid-height.
The horizontal convexity increases rapidly from the lower edge of the radials
upward to about the middle, beyond which it remains fairly constant. The
upper corners of the radials are somewhat notched forming shallow concave
grooves sloping upward and inward to the orals.

Each radial hears upon its distal surface an articular facet for the re-
ception of an arm. These do not extend over quite all the width of the radials
but are separated from each other by the shallow concave grooves mentioned
above. There is more variation in the size of the articular processes than
in any other part of this crinoid. Commonly that of the anterior radial is the
smallest and those of the posterior radials largest but the gradations in size
are not at all regular.

The orals form a rather flat-topped crown rising sharply above the
radials. In diameter and height the crown is nearly equal to the basal disc
and is on the whole less conspicuous in this than in most of the other species
here described. The oral plates are nearly uniform in size, the posterior one

0 In the Peoria district, the Lonsdale limestone occurs about 120 feet above coal Xo. 6.

LARVIFORM CRINOIDS 25

however being slightly wider than the others. This oral is also distinguished
by a tiny pore near its center. Above the radials and along the sutures be-
tween the orals in one specimen are five small openings which were probably
continuous with the ambulacral grooves of the arms.

The surface of the plates was apparently originally smooth although the
specimens, which are silicified, are slightly roughened. The preservation of
the plates suggests a minutely porous surface.

Remarks. — This species is typical of the simpler type of Kallimorpho-
c ri)i its which has a lobed horizontal outline and whose radials have not de-
veloped longitudinal angulations. It is unnecessary to compare it with any
of the foregoing species.

Occurrence. — This species occurs in a dark limestone not far above the
base of the Pennsylvanian section near the center of the N. ^ sec. 35,
T. 21 N., R. 9 W., Warren County, Indiana.

Kallimorphocrinus illinoisensis J. M. Weller, n. sp.
Plate II, figs. 2a-3b

Description. — The calyx is small and the width considerably exceeds the
height which in the holotype is 1.30 mm. The outline of the cup as seen
from above or below is strongly five-lobed owing to the very convex radials,
whose margins meet at an angle along the suture. The radials form about
four-fifths, and the basal disc about one-twelfth of the height, and the oral
crown is twice as high as the basal disc.

The basal disc is low and pentagonal in outline as viewed from beneath.
Its upper edge is cut by five deep scallops for the reception of the radials.
The circular stem facet does not occupy the entire under surface of the disc ;
its surface is shallowly concave surrounded by a raised border.

The radials are suboval in outline, about one and a half times as high
as wide. Their outer surfaces are strongly convex both longitudinally and
laterally. The longitudinal convexity is most pronounced in the lower half of
the radials, resulting in the greatest width of the calyx being developed at a
position about one-third of the distance above the base. The upper outer
edges of the radials are beveled and their distal surfaces are occupied by
articular processes for the attachment of the arms. The upper corners of
the radials are beveled so that the arm facets are separated by small and
shallow concave notches in which the orals rest.

The articular processes are not well preserved but they appear to be
similar to those of the other species here described.

The calyx is surmounted by a five-lobed oral crown which does not
overhang the radials. The upper surface of each oral is broadly and shallowly
concave.

26 I.ARVIFORM CRIXOIDS

The surface of the holotype is smooth and entirely unornamented.

Remarks. — In some respects this species resembles K. pocillus but the
proportions are different and its radials are much more convex, thus giving
a more pronounced lobation to its horizontal outline.

Occurrence. — The holotype was obtained from shale directly underlying
the Piasa limestone near the center of the NE. )/+ sec. 25, T. 8 N., R. 10 W.,
Jersey County, Illinois. The other figured specimen was collected by Mr.
J. B. Knight from the same stratigraphic horizon in the hollow just north
of the right-angle west turn of Scheute Road half a mile southwest of Lack-
land Station on the Chicago, Rock Island and Pacific Railway and three
quarters of a mile north of Stratman, St. Louis County, Missouri.

Kallimorphocrinus knighti J. M. Weller, n. sp.
Plate I, figs. 7a-b

Description. — The height of the holotype is 1.48 mm. and the greatest
width is approximately the same. Its outline as seen from above is sub-
pentagonal. The corners which are formed by the rounded angulations of
the radials are more or less narrowly rounded and the sides of the radials
meet at a very obtuse angle. The radials make up about three-fourths, the
basal disc one-twelfth, and the oral crown one-sixth of the total height. A
thin circular stem joint is attached to the base of the calyx.

The basal disc is subpentagonal with slightly convex sides. It slopes
strongly outward and upward from the proximal stem facet which occupies
most of its basal surface. The upper edge of the disc is cut by five sharp
scallops in which rest the radials.

The radials are oval below and truncated above. Their height is con-
siderably less than twice their greatest width. The median portions of the
radials are produced into narrowly rounded longitudinal angulations from
which nearly flat sides slope off to the sutures along which the adjacent radials
meet at a very obtuse angle. The lateral profile of the radials is convex with
the curvature largely localized near the middle so that the greatest width of
the calyx occurs at about mid-height. The upper outer edges of the radials
are partially beveled and the upper corners are depressed, producing shallow
concave notches in which the orals partially extend.

The articular processes of the radials on the holotype have been partially
obliterated but they were apparentlv large and strong. ( )ne of the radials.
the anterior one probably, is somewhat larger than any of the others but not
large enough to greatly mar the pentamerous symmetry.

The oral crown, although prominent, does not extend completely to the
edge of the radials at their junctions. This portion of the crinoid is rather
worn but the details of its structure, such as the shallow depressions of the

LARVIFORM CRIXOIDS

27

upper surfaces of the orals, are quite similar to those in the other species
here described.

The surface of the basal disc and radials is beautifully ornamented by
thickly grouped, small, low or irregularly rounded pustules.

Remarks. — This most striking species of Kallimorphocrinus can not be
confused with any other form as its shape and ornamentations are entirely
distinctive.

Occurrence. — The holotype of this species was collected by Mr. J. B.
Knight from the limestone overlying the horizon of the Belleville (No. 6)
coal about 200 feet west of Louisville Avenue on West Park Avenue, Chelten-
ham district, St. Louis, Missouri.

Kallimorphocrinus expansus J. M. Weller, n. sp.
Plate 1, figs. lOa-b

Description.—: -The greatest width of the calyx considerably exceeds the
height which in the holotype is 1.04 mm. The radials constitute about ten-
thirteenths of the height and the basal disc and oral crown make up respec-
tively about one-thirteenth and two-thirteenths of the total height. The
horizontal outline of the calyx is stellate with bluntly rounded angles and
concave sides.

The basal disc is pentagonal as viewed from below and its diameter is
equal to less than half the greatest width of the calyx. Its lower surface
is entirely occupied by a circular, slightly concave stem facet above which it
slopes upward and outward to the radials which rest in scallops cut in the
upper outer edge of the disc.

The height of the radials is equal to somewhat less than twice their mean
width and they are a little more than one and a half times as wide above as
below. These plates are convex both longitudinally and transversely. The
transverse convexity is largely localized to form a median longitudinal, more
or less narrowly rounded angulation from which the plates slope off gently
to form the concave sides of the calyx. The longitudinal convexity is fairly
regular and the greatest width of the calyx occurs near the upper edges of
the radials. The upper outer corners of the radials are rounded off and
produce at their junction concave depressions into which the orals extend.

The articular facets on the upper surfaces of the radials are not well
preserved but as far as may be observed they are comparable to those of the
other species of this genus.

The oral crown rises abruptly above the radials but does not overhang
them. The details of this part of the calyx are somewhat obscure but the
oral plates are apparently similar in form and arrangement to those seen in
the better preserved specimens of other species.

28 LARVIFORM CRIXOIDS

'J he surfaces of the plates are smooth and the calyx is entirely un-
ornamented.

Remarks. — This species most closely resembles K. illinoisensis with
which it is associated but is easily distinguished by the smaller size, the
narrower rounding of its radials, and the fact that the greatest width is
attained near the upper border of the radials.

Occurrence. — The holotvpe and several other specimens were obtained
from shale immediately underlying the Piasa limestone near the center of
the NE. % sec. 25, T. 8 N., R. 10 W., Jersey County, Illinois.

Genus AIDEMOCRINUS' J. M. Weller, n. gen.
Genotype Aidemocrinus odiosus J. M. Weller, n. sp.
This genus is introduced to accommodate a single species of tiny armless
crinoid whose calyx is composed of three rings of plates without a lateral
anal opening. It is tentatively assigned to the family Allagecrinidae.

Aidemocrinus odiosus J. M. Weller, n. sp.
Plate II, figs. 5a-b
Description. — The calyx is very small. The height of the holotype,
which is .55 mm., is equal to about one and one-third times the greatest
width. Although the sutures are not shown as clearly as might
be desired there can be little doubt concerning the structure of the
calyx. It is composed of three rings of plates which are inter-
preted as, (1) a basal disc. (2) five equal radials, and (3) an oral
FlG 3 dome of five subequal plates. The calyx is subpyramidal and
tion^of^the rises from the moderately sized proximal stem facet to the gently
ture'of'ilid- convex distal surface.

eo(Hosus"S The basal disc makes up about one-eleventh of the total height

wuhrnpiarfi, of the calyx. Its proximal surface is occupied by a circular stem
facet having a diameter equal to about one-third of the greatest
width of the calyx, and pierced by a single small central opening. The basal
disc rises nearly vertically from the stem facet to its upper edge which is
gently scalloped for the reception of the radials.

The radials form about two-thirds the height of the calyx, are about
twice as wide above as below, and about twice as long as the greatest width.
They are subovel below and above they are apparently more sharply truncated.
The upper edges of the radials are not very well defined, but the corners
appear to be rounded off. meeting in gently concave depressions in which
the orals rest. A rounded longitudinal ridge is developed down the center
of each radiak This ridge is beveled above producing a triangular area

* aiGrnucv, bashful.

LARVIFORM CRINOIDS 29

which slopes gently upward to the orals. The lateral surfaces of the ad-
joining radials meet to form a nearly plane surface in the middle of which
is the interradial suture.

Xo structures for the support of arms are developed on any of the
radials nor is an anal opening visihle in the calyx.

The oral dome, formed of five nearly equal plates which alternate with
the radials, constitutes a little more than a quarter of the total height of the
calyx and overhangs the radials so that when viewed from above none of
the lower plates are visible. The relation of the orals at the center of the
distal surface is not entirely clear but it appears that the two anterior plates
extend beyond the left and right posterior orals and fit into a notch in the
end of the posterior plate in the manner characteristic of Diclwstreblooimis
scrobiculus. They slope gently outward and downward from the center and
then turn sharply downward to meet the upper edges of the radials. The
upper surfaces of the orals have shallow depressions similar to those developed
on the oral plates of Kallirnorphocriniis.

The surfaces of the plates are minutely irregular and porous.

Remarks. — The systematic disposition of this little crinoid is a rather
perplexing problem. It is strikingly similar in form and appearance to certain
examples of Kallimorpkocrinus and differs from this genus only in the ab-
sence of arms and in the apparent relation of the orals at the center of the
distal surface which resembles Dichostreblocrinus rather than Kallimorpho-
cri nits. A. cdiosus can not be considered an immature stage in the develop-
ment of Kallimorphocrinus however as we have six similar specimens and
no intermediate stages.

On the other hand A. odiosits is very similar to certain specimens con-
sidered to be immature stages of Dichostreblocrinus scrobiculus (p. 37).
From these however it differs in its more slender proportions and in the
character of the distal surface of the orals.

Were it not for the character of its oral crown A. odiosus might be
referred to the Hypocrinidae. In this case the intermediate ring of plates
would have to be considered basals and the calyx structure would differ from
Acariaiocrinus only in the absence of a lateral anal opening.

Occurrence. — These silicified specimens were obtained from a limestone
low in the Pennsylvanian section of Warren County, Indiana, near the center
of the X. j4 sec.35, T. 21 X., R. 9 W.

FAMILY HYPOCRIXIDAE

The family Hypocrinidae was erected by Wanner in 1916 who assigned
to it Hypocrinus Beyrich, Sycocrinus Austin, Cydonocrinus Bather and the
new genera Monobrachiocrinus, Thetidocrinus and Bolbocrinus [14, p. 88].

30

LARVIFORM CRINOIDS

At the same time he introduced the family Embryocrinidae based upon the
new genus Embryocrinus [14, p. 130].

In 1920 Wanner discussed in detail the relationships of the various
members of the Hypocrinidae [15]. At this time he abandoned the Embryo-
crinidae and added to the Hypocrinidae the following genera. Embryocrinus
Wanner, Lageniocrinus de Koninck and Le Hon, Coenocystis Girty and the

COENOCYSTIS

I

further displacement

of orals and anal opening

ACARIAIOCRINUS HEMISTREPTACON

atrophy of radial3 atrophy of radlals
displacement of orals and displacement
of orals and anus

ATREMAC3INU3

anchylosis of
basals and

' 1 lnfrabasals

I I

TENAGOCRINTJS CRAN0CRINU5 EMBRYOCRINUS LAGENIOCRINUS

Permian Period

Pennsylvania!! Period

migration of brachial
muscle fields to orals

TYTTHOCRrNUS

atrophy of radlals

LAGENIOCRINUS

1

atrophy of radlals
and anal opening

AMPHIPSAI.IDOCRINUS

DICHOSTREBLOCRINUS

1

atrophy of radlals
displacement of orals
in opposite direction

atrophy of arms
dwarfing of radlals

dwarfing of arms and radlals
displacement of anal opening

Fig. 4

new genera Metasycocrinus and Abrachiocrinus based upon previously de-
scribed species. In 1923 two more new genera. Allosycocrinus and Acariaio-
crinus were added to the Hypocrinidae [16, p. 133 ff].

In a more recent paper Wanner has further expanded this interesting
family by the addition of Hemistreptacon Jakovlev and the new genera
Tenagocrinus, Cranocrinus, and Atremacrinus [17, p. 84 ff].

LARVIFORM CRINOIDS

31

Wanner is of the opinion that this group of crinoids forms a degenerate
series which developed from more complex ancestors by the partial or com-
plete atrophy of the radials and arms, displacement of the anal opening from
its normal posterior position toward one of the neighboring radii or completely
out of the dorsal cup of the crinoid, and displacement of the oral plates from
their original interradial position to a more or less perfectly radial position.

Our Pennsylvanian collections contain a group of small crinoids whose
characters ally them to the Hypocrinidae. They are assigned to Lagenio-
crinus de Koninck and Le Hon and the three new genera Am pliipsalid ocrinus ,
TytthocrinnSj and Dichostreblocrinus. Their relations and their probable
evolution is shown in the diagram (Fig. 4) of a portion of the Hypocrinidae
which is modified after Wanner [17, p. 98].

Genus LAGEN I OCRINUS de Koninck and Le Hon 1854
Genotype Lageniocrinus seminulus de Koninck and Le Hon

The genus Lageniocrinus was established upon a small species of crinoid
which is very rare in the Lower Carboniferous limestone of Vise, Belgium
[3, p. 187J. This crinoid is composed of three rings of plates which were
originally interpreted as a circle of three basals and two radial circles of five
plates each, forming a completely enclosed flagon-shaped body. It was
suggested that this small crinoid is transitional between the Platycrinidae and
the Blastoidea. Zittel regarded the upper ring of plates as arm joints [18,
p. 350] and this view was shared by Wachsmuth and Springer [13, p. 175]
who suggested that this crinoid was possibly a young stage of Synbathocrinus.
Later both Bather [1, p. 152] and Springer [9, p. 209] placed Lageniocrinus
in synonomy under Synbathocrinus.

In a detailed discussion incidental to his description of the new genus
Embryocrinus, Wanner returned Lageniocrinus to an independent generic
standing, pointed out its very primitive character, comparing it to a larval
stage of the living Antedon and distinguished the upper circle of plates as
orals [14. p. 134].

More recently, Jakovlev has offered the opinion that the isolated speci-
mens of Lageniocrinus that have hitherto been found are simply abnormal
examples of other more common crinoids [6, p. 313]. This view resulted
from his study of a series of nearly a thousand specimens of Hcuiistrcptacon
abracliiatus from the Permo-Carboniferous of the Ural Mountains among
which he found one example similar in structure to Lageniocrinus but appar-
ently connected by intermediate stages with Hcmistreptacon.

Six specimens of a minute crinoid which is constructed similarly to the
genotype of Lageniocrinus, all obtained from the same locality, are of ap-
proximately similar size and must be regarded as mature individuals for they

2)2 I.ARVIFORM CRIXOIDS

are not associated with any other crinoid with which they might be connected
as aberrant examples. It is necessary therefore to follow Wanner in his
opinion that Lageniocrinns is a valid genus.

Lageniocrini s cassidus J. M. Weller, n. sp.
Plate II, figs. 6a-b
Description. — The calyx is subglobular and very small, the height of the
holotypc being .74 mm. and the largest specimen obtained .92 mm. The
sutures between the plates are not clearly visible, but the calyx
appears to be composed of three rings of plates which are
interpretated as, ( 1 ) a low more or less compressed infra-
basal disc, (2) five equal basals, and (3) five approximately
equal orals. Of these the basals make up the greater part of
the height of the calyx.
interpretation T]ie infrabasal disc is somewhat variable in the different

of the calyx

structure or specimens. In the holotvpe it is low and platelike with a large

Lagemocrinus * J l *

cassns (com- round proximal stem facet. In some of the others however

pare with PI. l

ii, fig. 6a). ^ is somewhat higher and possesses a smaller stem facet and

consequently is obtusely funnel-like in form. It is pierced by a single small
central canal.

The size and shape of the basals are somewhat difficult to describe owing
to the questionable position of the sutures bounding them above. Interpreted
in accordance with figure 5 they are somewhat less than twice as high as wide,
rounded below, evenly truncated above and bounded laterally by nearly parallel
sides. Near the middle they are swollen into broad rounded areas which
stand out prominently above the infrabasal disc. Above each of these swell-
ings is a diamond shaped area formed of two flat equilaterally subtriangular
areas, the lower of which occupies the upper part of the basal while the upper
one is formed by the outer proximal portion of the superjacent oral. These
areas slope inward slightly and meet each other at an obtuse angle.

The oral crown forms a nearly circular cover extending over the entire
ventral surface of the body. It is composed of five equal oral plates which
are disposed in series above the basals. The interoral sutures are not clearly
shown but they appear to be situated at the bottoms of five radiating troughs
which extend outward from the center of the oral crown.

Xo anal opening is present in the side of the calyx.

Remarks. — This species deviates greatly from the simple pyriform shape
of the genotype but its structure conforms perfectly to that of Lagcniocrimts
and it is referred to this genus without hesitation.

Occurrence. — Collected from limestone near the base of the Pennsyl-
vanian near the center of the N. J/2 sec. 35, T. 21 N., R. 9 W., Warren County,
Indiana.

LARVIFORM CRINOIDS

33

Genus AMPHIPSALIDOCRINUS8 J. M. Weller. n. gen.
Genotype Amphipsalidocrinus scissurus J. M. Weller. n. sp.

Wanner has recently described two new genera of crinoids — Cranocrinus
and Tenagocrinus — from the Permian deposits of Timor which are composed
of an infrabasal disc, five basals, five radials and five orals with a lateral anal
opening piercing the cup [17, pp. 41, 48]. Tenagocrinus differs from Crano-
crinus in that its radials are shrunken so that they no longer meet laterally
and the anal opening has been drawn toward the right from the center of the
posterior interradius so that the calyx is no longer symmetrical. In Crano-
crinus the oral plates are concave and meet each other along ridges which
radiate from the center of the crown. In Tenagocrinus the orals are convex
and meet in rounded furrows which apparently served as protective receptacles
for the contracted arms. Moreover in this genus the stunted radials no
longer bore fields for the attachment of the brachial muscles but in a most
peculiar fashion the muscles in these forms were attached to sunken areas
near the proximal corners of the orals.

In our collection there is an interesting little crinoid which appears to
be intermediate between Cranocrinus and Tenagocrinus. Although the sutures
cannot all be clearly seen, the oral dome resembles that of Cranocrinus
whereas the dorsal cup appears to be identical with Tenagocrinus. For the
reception of this crinoid the new genus Amphipsalidocrinus is introduced.
This genus differs from the typical examples of Cranocrinus in possessing
shrunken radials and an anal opening which has been drawn to the right from
the center of the posterior interradius and it differs from Tenagocrinus in
not being furnished with interoral furrows into which the fields of attach-
ment of the brachial muscles have migrated.

Amphipsalidocrinus scissurus J. M. Weller, n. sp.
Plate II, figs. 8a-c

Fig. 6

Interpretation of the calyx structures of Amphipsali-
docrinus scissurus (compare with PI. II, figs.
8a, b).

Description. — The calyx of the holotype is .63 mm. in height and of
slightly greater maximum breadth. It is mushroom shaped, expanding rapidly
from a moderately sized stem facet into a large, over-hanging star-shaped

8d/j0i, (stretching) around; i^aXi's, dome.

34 LARVIFORM CRIXOIDS

vault. Although the sutures between the plates can not be made out with
certainty the plates are probably arranged as follows: (1) a low and small
infrabasal disc; (2) a ring of five rather short irregular and somewhat un-
equally sized basal plates; (3) five stunted radial plates that do not meet
laterally ; and (4) a comparatively large inflated vault composed of five oral
plates.

Although the details of the basal disc can not be determined it is un-
doubtedly low and saucer shaped and its lower part slopes steeply downward
to the circular stem facet.

The basal plates are probably rather irregularly sub-hexagonal in out-
line and of somewhat different size. The proportion of height to width varies
but the dimensions are approximately the same. The height of these plates
differs however with the result that the little radial plates stand at varying
distances above the base of the calyx.

The radials are very small. Near the middle of the upper edge of each
occurs a small triangular drooping lip which is interpreted as an arm facet.
The arms must have been very small. No articular processes have been
observed in connection with these nor are openings into the interior of the
calyx visible.

The anal opening is situated slightly below the level of the right posterior
arm facet and much nearer this than the left posterior facet. It is very small
but rendered conspicuous by a curved outstanding lip which occurs beneath it.

The oral vault makes up by far the greater part of the calyx. The
individual plates are of approximately equal size and shape except that the
posterior oral is somewhat wider than the others. As they slope gently out-
ward from the center of the ventral surface the oral plates become broadly
concave between their somewhat upraised edges which meet and form five
broadly rounded radiating ridges. As the orals curve sharply downward to
form the upper part of the sides of the calyx their median concave depres-
sions persist but their edges probably produced sharp angular vertical ribs
strongly developed to a positon only a short distance above the arm facets.
These vertical ribs have been broken off from the holotype however and ap-
pear in this specimen as narrow slits leading into the interior of the calyx.

The surface of the holotype. which is silicified, is rather rough probably
indicating that the plates were originally minutely porous.

Remarks. — This species closely resembles certain abnormal specimens
of Cranocrinus figured by Wanner [17, pi. 1, figs. 10. 11 |. but its association
with Tytthocrinus comptus, described below, is evidence that it is actually
the normal representative of a type intermediate between Cranocrinus and
Tenagocrinus.

LARVIFORM CRIXOIDS 35

Occurrence. — -The holotype, which is entirely silicified, was obtained
from a dark limestone near the base of the Pennsylvanian strata near the
center of the N. y2 sec. 35, T. 21 N., R. 9 W., Warren County, Indiana.

Genus TYTTHOCRINUS9 J. M. Weller, n. gen.

Genotype Tytthocrinus comptus J. M. Weller, n. sp.

Tytthocrinits differs from Amphipsalidocrinus in the further degenera-
tion of its radials and arms. This form is armless and the radials are either
exceedingly minute or absent. The anal opening has been displaced farther
to the right and lies nearly in the right posterior radius.

Tytthocrinus comptus J. M. Weller, n. sp.

Plate II, figs. 7a-b

Description. — The calyx is very small and somewhat broader than high.

The height of the holotype is .44 mm. The body expands rapidly from a

moderately sized stem facet to the gently sloping

subpentagonal distal surface. The arrangement and

number of the plates is not certainly known because

of the indistinct sutures separating them, but they

Fig. 7 appear to be disposed in three circles, ( 1 ) a very low

interpretation of the calyx infrabasal disc, (2) a ring of low basals, and (3) five

structure of Tytthocrinus , i i • 1 • 1 ^i i i. r ^i i 1

comvtus (compare with large orals which inclose the greater part ot the bodv

PI. II, fig. 7a).

cavity.
The infrabasal disc is very low and forms about one-eleventh of the
total height of the calyx. Its lower surface is the circular stem facet having
a diameter equal to about two-fifths of the maximum width of the body.
It is flat and pierced by a single central opening. The sides of the infra-
basal disc rise nearly vertically and the position of its upper margin is marked
by a very slight constriction which passes around the crinoid just above its
base beyond which small obtuse points project into the angles between the
basals.

The basals are low and form about three-elevenths of the total height of
the calyx. The sutures separating them can not be made out but the basals
are apparently subpentagonal in outline and somewhat wider than high. It
is possible that some of them are larger than others. No indication of radials
has been observed.

The comparatively large anal opening is situated between the ring of
basals and the orals. Although it occurs in the posterior interradius it is
strongly displaced to the right, nearly to the right posterior radius.

8 tvtBos, small.

36 I.ARVIFORM CRINOIDS

The oral plates with the exception of the posterior one are of approxi-
mately similar size and shape. The posterior oral however is somewhat wider
than the others and its upper extremity fits in between the anterior orals thus
separating the left and right posterior plates. The oral dome constitutes
about nine-elevenths of the total height of the calyx. The plates slope gently
outward and downward from the center of the distal surface to a position
about three-elevenths of the total height below the top of the calyx, at which
position the greatest width is attained. They are then deflected sharply down-
ward and slope inward to meet the basals below. The oral plates are gently
concave transversely and they meet along rounded ridges which stand out
most prominently at the angle between the upper and lateral surfaces.

The surfaces of the plates are roughened by very hue irregularities.

Remarks. — This species is the most abundant of the tiny silicified crinoids
collected in Warren County, Indiana. About forty specimens have been
examined and nearly all of them are comparable in size to the holotype.
Were specimens of this species rarer and those of Amphipsalidocrinus scis-
surus more abundant it would be natural to conclude that the present form
is simply an immature representative of the latter species. The only conspicu-
ous difference between these two is the presence or absence of the arms.
The larger species was arm-bearing and it is easy to conceive that the arms
were not developed until the individuals had grown to a size exceeding that
of the smaller form. However, the numerical disparagement is such that this
can not be the case and there is no doubt but that the smaller forms are
mature individuals of a different species.

Occurrence. — This species was obtained from a limestone in the lower
part of the Pennsylvanian deposits of Warren Count}-. Indiana, near the
center of the N. V2 sec. 35, T. 21 X., R. 9 W.

Genus DICHOSTREBLOCRIXVS1" J. M. Weller. n. gen.
Genotype Dichostreblocrinus scrobiculus J. M. Weller, n. sp.

The subpyriform calyx is composed of three rings of plates which are
interpreted as, (1) an infrabasal disc, (2) five basals. and (3) five orals.
The laterally situated anal opening has been displaced to the right from the
posterior interradius nearly to the right posterior radius and lies in a deep
scallop in the upper right-hand corner of the posterior basal. The orals on
the other hand have been slightly displaced to the left so that they are no
longer exactly interradial in position.

A number of armless crinoids of somewhat similar calyx structure are
known in which displacement of the orals or of the anal opening has taken

'"tfi'xa, in two ways; ffrpeflXis, deformed or twisted.

LARVIFORM CRINOIDS

37

place. The following table summarizes the distinguishing characters of the
various genera :

Displacement of Displacement of

oral plates anal opening

Left Right Left Right

Hemistreptacon Jakovlev 12° 12°

Coenocystis Girty 36° 36°

Acariaiocrinus Wanner 36° 0°

Dichostreblocrinus J. M. Weller, n. gen. 9° 12"

Tytthocrinus Weller, n. gen. 0° 24°

Dichostreblocrinus scrobiculus J. M. Weller, n. sp.
Plate II, figs. 9a-d

Fig. 8

Plan of the calyx of Dichostrehlocrinus
scrobiculus

Description. — The holotvpe has a height of 1.78 mm. which is about one
and a half times its greatest breadth. The calyx is subpyriform with a sub-
circular, subpentagonal cross-section. It is composed of three rings of plates,
(1) a small infrabasal disc, (2) five approximately equal basals, and (3) five
subequal orals.

The form and size of the infrabasal disc is not known as the sutures
separating it from the basals are not distinguishable, but it probably makes
up about one-sixth of the total height of the calyx. From the moderately
sized stem facet pierced by a single central opening it slopes upward and
outward to the basals.

The basal plates constitute about two-thirds of the height of the calyx.
They are wider above than below, sharply truncated above and probably sub-
oval below, and their height is equal to about one and one half times the
greatest width. Each basal plate bears a longitudinal more or less broadly
rounded ridge from which the plate slopes away on either side to join its
neighbors in the flat or gently concave lateral sides of the calvx. The basal
plates are rather regularly and uniformly shaped but the longitudinal ridges
are commonly somewhat inclined to the axes of these plates and thus produce

38 LARVIFORM CRINOIDS

an anomalous appearance as though the lower part of the calyx had been
twisted.

The large anal opening is situated in a deep scallop in the upper right-
hand corner of the posterior basal. It lies largely within this plate but is
also bordered by the right posterior basal, and the posterior and right posterior
orals.

The oral dome covers the entire ventral surface of the calyx and con-
stitutes about one-fourth its height. The oral plates are triangular above
except for the posterior one whose upper angle is notched to receive the ends
of the anterior orals. The upper surfaces are flat but the edges are rather
sharply upraised and the orals meet along five radiating ridges. At the edge
of the ventral surface the oral plates bend sharply downward to meet the
basals below.

The entire surface of the holotype is covered with comparatively large
but unequally sized and irregularly arranged pits. They are largest and
most conspicuous on the oral plates and decrease notably in size or are absent
near the sutures which in this way only are distinguishable.

Remarks. — I have included in a single series a considerable number of
specimens ranging in size from about .5 mm. to the holotype which is the
largest, considering the smaller ones to be immature examples. The second
specimen figured on Plate II (9d) is the second largest. This and the
holotype alone show the lateral anal opening, and were there not two speci-
mens this opening would have been considered an accidental break, so pecu-
liar is its situation. The smaller specimens also differ from the larger in
not being so conspicuously pitted, nor is the twisting of the calyx apparent
in them. This series seems to show that the displacement of the orals and
the appearance and displacement of the anal opening are features which were
progressively developed during the growth of this crinoid, substantiating a
similar opinion formed by Jakovlev [6] from a study of a large number of
specimens of Hemistreptacon.

Occurrence. — These silicified specimens were obtained from a limestone
near the base of the Pennsylvanian section in the center of the N. */> sec. 35,
T. 21 N., R. 9 W., Warren County, Indiana.

PLATES AND EXPLANATIONS

EXPLANATION OF PLATE I

All figures are enlarged fifteen diameters except 3c which is enlarged twenty diameters.
Figs. la-c. Hybochilocrinus americanus (Rowley) p. 13

la. A specimen in which the anal plate has been preserved, seen
from the right posterior radius.

lb. Another specimen showing the beveling of the upper left-hand
corner of the radial in which the anal plate rested (seen from
the same position as la).

lc. Ventral view of the specimen shown in lb.
Figs. 2a-c. Kallimorphocrinus astrus typicus J. M. Weller, n. sp., n. var p. 17

2a. Lateral view of the holotype.

2b. Dorsal view of the holotype.

2c. Ventral view of a specimen having a broken oral crown.
Figs. 3a-c. Kallimorphocrinus astrus intermedius J. M. Weller, n. var p. 18

3a. Lateral view of the holotype.

3b. Dorsal view of the holotype.

3c. Oral crown of the same showing an abnormal relation of the
plates (x 20).
Figs. 4a-c. Kallimorphocrinus astrus pyramidalis J. M. Weller, n. var p. 18

4a. Lateral view of the holotype.

4b. Dorsal view of the holotype.

4c. Ventral view of the holotype.
Figs. Sa-b. Kallimorphocrinus piasaensis J. M. Weller, n. sp p. 18

Sa. Lateral view of the holotype.

5b. Ventral view of the holotype.
Figs. 6a-b. Kallimorphocrinus vanpelti J. M. Weller, n. sp p. 21

6a. Lateral view of the holotype from the left posterior radius.

6b. Ventral view of the holotype.
Figs. 7a-b. Kallimorphocrinus knighti J. M. Weller, n. sp p. 26

7a. Lateral view of the holotype from the right anterior radius.

7b. Dorsal view of the holotype, the anterior radius is above.
Figs. 8a-b. Kallimorphocrinus i.ilius J. M. Weller, n. sp p. 19

8a. Lateral view of the holotype.

8b. Ventral view of the holotype.
Figs. 9a-b. Kallimorphocrinus indianensis J. M. Weller, n. sp p. 20

9a. Lateral view of the holotype.

9b. Ventral view of the holotype.
Figs. lOa-b. Kallimorphocrinus expansus J. M. Weller, n. sp p. 27

10a. Lateral view of the holotype.

10b. Dorsal view of the holotype.

(40)

Illinois State Geological Survey Report of Investigations No. 21, Plate I

la

o>

lb

2c

7a

2b

3a

4a

3b

4b

3c

4c

7b

8a

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8b

5a

5b

9a

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f

9b

WSl

6a

6b

10a

10b

EXPLANATION OF PLATE II
All figures are enlarged fifteen diameters except Id which is enlarged twenty diameters.
Figs. la-d. Kallimorpiiocrinus pocillus J. M. Weller, n. sp p. 24

la. Lateral view of the holotype.

lb. Dorsal view of the holotype.

lc. Ventral view of the holotype.

Id. Detail of a radial arm facet (x 20).
Figs. 2a-3b. Kallimorphocrinus ili.inoisensis J. M. Weller, n. sp p. 25

2a. Lateral view of the holotype.

2b. Dorsal view of the holotype, uppermost stem joint attached.

3a. Lateral view of a specimen from St. Louis without the upper-
most stem joint.

3b. Dorsal view of the same specimen.
Figs. 4a-b. Kallimorphocri.ms infacetus J. M. Weller, n. sp p. 22

4a. Lateral view of the holotype from the right posterior radius.

4b. Ventral view of the holotype.
Figs. 5a-b. Aidemocrinus odiosus J. M. Weller, n. sp p. 28

5a. Lateral view of the holotype.

5b. Ventral view of the holotype.
Figs. 6a-b. Lageniocrinus cassidus J. M. Weller. n. sp p. 32

6a. Lateral view of the holotype.

6b. Ventral view of the holotype.
Figs. 7a-b. Tytthocrixus comptus J. M. Weller, n. sp p. 35

7a. Lateral view of the holotype, from the posterior interradius.

7b. Ventral view of the holotype.
Figs. 8a-c. Amphipsalidocri.ntus scissurus J. M. Weller, n. sp p. 33

8a. Lateral view of the holotype, from the posterior interradius.

8b. Lateral view of the holotype, from the anterior radius.

8c. Ventral view of the holotype.
Figs. 9a-d. Dichostreblocrinus scrobiculus J. M. Weller, n. sp p. 37

9a. Lateral view of the holotype, from the left posterior radius.

9b. Lateral view of the holotype, from the left anterior radius.

9c. Ventral view of the holotype.

9d. Lateral view of another specimen, from the posterior interradius.

(42)

Illinois State Geological Survey Report of Investigations No. 21, Plate II

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